WO2025170005A1 - Viscosity modifier, method for producing same, curable composition, and non-aqueous paint composition - Google Patents

Abstract

Provided are a viscosity modifier and a method for producing the same, the viscosity modifier comprising a mixture (M) obtained by melting and mixing compounds including: a diamide compound (A) obtained by condensing a diamine component and a monocarboxylic acid component (A-c); a diamide compound (B) obtained by condensing a diamine component and a monocarboxylic acid component (B-c); and a diamide compound (C) obtained by condensing a diamine component and a monocarboxylic acid component (C-c). The monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) have mutually different numbers of carbon atoms, and at least one of the monocarboxylic acid component (A-c), the monocarboxylic acid component (B-c), and the monocarboxylic acid component (C-c) contains a hydrogenated castor oil fatty acid. Also provided are a curable composition and a non-aqueous paint composition in which the viscosity modifier is used.

Description

Viscosity modifier, its manufacturing method, curable composition, and non-aqueous coating composition

The present invention relates to a viscosity modifier, a method for producing the same, and a curable composition and a non-aqueous coating composition that use the viscosity modifier.

Sealants that use polyoxyalkylenes with reactive silyl groups at the ends as the base polymer are called modified silicone sealants. Modified silicone sealants are widely used due to their excellent durability and cost-effectiveness, but they have the problem of poor weather resistance and heat resistance in the sealant's usage environment. Therefore, from the perspective of reducing the environmental impact, there is a demand for sealants that can be used for longer periods than modified silicone sealants.

In response to this, by changing the main chain skeleton from polyoxyalkylene to (meth)acrylic polymer, it is possible to give the sealant high weather resistance and high heat resistance that cannot be achieved with modified silicone sealants. This sealant is called a silylated acrylate sealant, and its high weather resistance allows it to be used for long periods of time, extending the maintenance period and reducing the environmental impact. In this way, because silylated acrylate sealants can extend the maintenance period, the amount of raw materials used for the sealant can be reduced, and given recent trends such as the SDGs, it is a product whose usage is expected to increase in the future.

In addition, various viscosity modifiers (thixotropic agents) are sometimes added to sealants to impart viscosity. One such viscosity modifier, an amide-based viscosity modifier primarily composed of a fatty acid diamide, is widely used (see, for example, Patent Documents 1 to 3). Patent Document 1 discloses a powdered anti-sagging agent for addition to non-aqueous anti-corrosion paints with a low solvent content, which is a melt-mix of (A) a condensate of a diamine with a mixture of hydrogenated castor oil fatty acid and one or more aliphatic monocarboxylic acids (C2-C22 acids) that do not contain hydrogenated castor oil fatty acid, (B) a condensate of one or more aliphatic monocarboxylic acids (C2-C22 acids) with a diamine, and (C) a carboxyl group-containing polyolefin wax. This powdered anti-sagging agent is said to have excellent anti-sagging properties and storage stability even when dispersed at low temperatures. Patent Document 2 discloses a thixotropic agent obtained by reacting a mixture of hydrogenated castor oil fatty acids and alkanoic acids (C6-C12) with EDA and 1,4-DAB. This thixotropic agent is said to be able to swell and remain stable even at dispersion temperatures of 50-70°C and in organic vehicles with low dissolving power. Patent Document 3 discloses a polyamide composition comprising a diamine (EDA or HMDA), a linear monocarboxylic acid (having 1-5 carbon atoms, particularly a C2 acid, a C3 acid, or a combination thereof), and a fatty acid (12-HSA, lesquerolic acid, or a combination thereof). This polyamide composition is said to be easily activatable, thereby suppressing viscosity changes and gloss loss over time.

JP 2013-49761 A Japanese Unexamined Patent Publication No. 56-112977 U.S. Patent No. 10,894,900

However, silylated acrylate sealants with a (meth)acrylic polymer backbone have low compatibility with the amide viscosity modifiers described in Patent Documents 1 to 3. As a result, when an amide viscosity modifier is added to a silylated acrylate sealant, the fatty acid diamide does not swell sufficiently, making it difficult to achieve the viscosity-imparting effect.

Furthermore, in order to reduce the energy consumed during production, the production of modified silicone sealants using a cold process (low-temperature mixing), which minimizes heating, is being widely studied and is becoming mainstream worldwide. Furthermore, if cold processing becomes possible, modified silicone sealants can be manufactured even in places that do not have heating equipment. Even when modified silicone sealants and amide viscosity modifiers are mixed at low temperatures using this cold process, the fatty acid diamide does not swell easily, making it difficult for the viscosity-imparting effect of the amide viscosity modifier to be exerted.

Furthermore, in non-water-based paints such as epoxy paints used in marine or heavy-duty corrosion-resistant paints, there is a trend toward reducing the amount of organic solvents in the paint, in order to reduce environmental impact, particularly emissions of volatile organic compounds (VOCs). Even when an amide-based viscosity modifier is added to so-called ultra-high solids (UHS) paints or solvent-free paints, which are paints with reduced organic solvent content, the fatty acid diamides are less likely to swell, making it difficult for the viscosity-imparting effect of the amide-based viscosity modifier to be exerted.

In all of the above cases, when an amide-based viscosity modifier is added, the fatty acid diamide is less likely to swell and the viscosity-imparting effect is less likely to be achieved. There is a need for the development of an amide-based viscosity modifier that can sufficiently swell the fatty acid diamide and exert its viscosity-imparting effect even under these harsh conditions.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a viscosity modifier that allows fatty acid diamides to swell sufficiently and that can exert a viscosity-imparting effect even in the following cases (i) to (iii), a method for producing the same, and a curable composition and a non-aqueous coating composition that use the viscosity modifier.
(i) When an amide-based viscosity modifier is added to a silylated acrylate-based sealant. (ii) When a modified silicone-based sealant and an amide-based viscosity modifier are kneaded by cold processing. (iii) When an amide-based viscosity modifier is added to a non-aqueous paint with a reduced amount of organic solvent.

As a result of extensive research to solve the above problems, the inventors discovered that by using a mixture obtained by melt-mixing at least two types of diamide compounds with different chain lengths, which mixture contains a diamide compound obtained using hydrogenated castor oil fatty acid, as a viscosity adjuster, the fatty acid diamide can be sufficiently swelled and can exert a viscosity-imparting effect even in the above cases (i) to (iii), and the present invention was completed based on this finding.

In other words, the present invention relates to a viscosity modifier comprising a mixture (M) obtained by melt-mixing two or more compounds including a diamide compound (A), a diamide compound (B), and an optional diamide compound (C), wherein the diamide compound (A) is a diamide obtained by condensing a diamine component (A-a) with a monocarboxylic acid component (A-c), the diamide compound (B) is a diamide obtained by condensing a diamine component (B-a) with a monocarboxylic acid component (B-c), the diamide compound (C) is a diamide obtained by condensing a diamine component (C-a) with a monocarboxylic acid component (C-c), the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) being monocarboxylic acids having different numbers of carbon atoms, and at least one of the monocarboxylic acid component (A-c), the monocarboxylic acid component (B-c), and the monocarboxylic acid component (C-c) contains hydrogenated castor oil fatty acid.

In one embodiment of the viscosity modifier of the present invention, it is preferable that the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) are both monocarboxylic acids having 2 to 18 carbon atoms.

In another aspect of the viscosity modifier of the present invention, it is preferable that the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) is 16 or less.

In another aspect of the viscosity modifier of the present invention, it is preferable that the monocarboxylic acid component (A-c) contains at least a linear saturated fatty acid (a), and the monocarboxylic acid component (B-c) contains at least a linear saturated fatty acid (b).

In another embodiment of the viscosity modifier of the present invention, when the monocarboxylic acid component (Ac) contains hydrogenated castor oil fatty acid and the monocarboxylic acid component (Bc) does not contain hydrogenated castor oil fatty acid and does not contain the diamide compound (C), it is preferable that the mixing ratio (A/B) of the diamide compound (A) to the diamide compound (B) is 95/5 to 55/45.

In another aspect of the viscosity modifier of the present invention, it is preferable that the diamine component (A-a) and the diamine component (Ba) are the same type of diamine.

The present invention also provides a method for producing a viscosity modifier comprising: a mixing step of melt-mixing two or more compounds including a diamide compound (A), a diamide compound (B), and an optional diamide compound (C); and a micronization step of micronizing the mixture (M) obtained in the mixing step to obtain a viscosity modifier; wherein the diamide compound (A) is a diamide obtained by condensing a diamine component (A-a) with a monocarboxylic acid component (A-c); and the diamide compound (B) is a diamide obtained by condensing a diamine component (B-a) with a monocarboxylic acid component (B-c). The diamide compound (C) is a diamide obtained by condensing a diamine component (C-a) and a monocarboxylic acid component (C-c), the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) are monocarboxylic acids having different numbers of carbon atoms, and at least one of the monocarboxylic acid component (A-c), the monocarboxylic acid component (B-c), and the monocarboxylic acid component (C-c) contains hydrogenated castor oil fatty acid.

In one embodiment of the viscosity modifier manufacturing method of the present invention, it is preferable that both the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) are monocarboxylic acids having 2 to 18 carbon atoms.

In another aspect of the method for producing a viscosity modifier of the present invention, it is preferable that the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) is 16 or less.

In another aspect of the method for producing a viscosity modifier of the present invention, it is preferable that the monocarboxylic acid component (A-c) contains at least a linear saturated fatty acid (a), and the monocarboxylic acid component (B-c) contains at least a linear saturated fatty acid (b).

In another aspect of the viscosity modifier manufacturing method of the present invention, when the monocarboxylic acid component (A-c) contains hydrogenated castor oil fatty acid and the monocarboxylic acid component (B-c) does not contain hydrogenated castor oil fatty acid and does not contain the diamide compound (C), it is preferable that the mixing ratio (A/B) of the diamide compound (A) to the diamide compound (B) is 95/5 to 55/45.

In another aspect of the viscosity modifier manufacturing method of the present invention, it is preferable that the diamine component (A-a) and the diamine component (Ba) are the same type of diamine.

The present invention also relates to a curable composition containing the viscosity modifier described above and a resin component.

The present invention also relates to a non-aqueous coating composition containing the viscosity modifier described above, a resin component, and, as an optional component, a volatile solvent, wherein the content of the volatile solvent is 15 mass% or less based on the total amount of the non-aqueous coating composition.

According to the present invention, by using a mixture obtained by melt-mixing at least two types of diamide compounds with different chain lengths, which mixture contains a diamide compound obtained using hydrogenated castor oil fatty acid, as a viscosity modifier, it is possible to obtain a sufficient viscosity-imparting effect compared to the amide-based viscosity modifiers disclosed in prior art documents, even in cases (i) to (iii) above.

The following describes in detail a preferred embodiment of the present invention.

[Viscosity adjuster]
The viscosity modifier of the present invention comprises a mixture (M) obtained by melt-mixing two or more compounds, including a diamide compound (A) as an essential component, a diamide compound (B) as an essential component, and a diamide compound (C) as an optional component. By including the components described in detail below in the mixture (M), the fatty acid diamide can be sufficiently swollen and activated even in the following cases (i) to (iii). Therefore, the viscosity modifier of the present invention can exhibit a sufficient viscosity-imparting effect compared to the amide-based viscosity modifiers disclosed in the prior art documents mentioned above.
(i) When a fatty acid diamide viscosity modifier is added to a silylated acrylate sealant. (ii) When a modified silicone sealant and a fatty acid diamide viscosity modifier are kneaded by the cold process (generally, about 50°C to 60°C) or at a temperature lower than the cold process (for example, room temperature, about 20°C to 30°C). (iii) When a fatty acid diamide viscosity modifier is added to a non-aqueous paint with a reduced amount of organic solvent.

The principle by which amide-based viscosity modifiers exert their viscosity-imparting effect is as follows: The fatty acid diamide, the main component of amide-based viscosity modifiers (the diamide compounds (A), (B), and (C) in this invention are also fatty acid diamides), changes from a particulate to a needle-like form upon swelling and becomes activated. The activated fatty acid diamide can impart stable viscosity to systems such as curable compositions like sealants and non-aqueous paint compositions like marine or heavy-duty corrosion-protective paints. As a result, a sufficient viscosity-imparting effect is exhibited. However, under conditions where the fatty acid diamide is difficult to swell and activate, such as in the above cases (i) to (iii), it is presumed that the fatty acid diamide powder (solid particles) tends to aggregate and form agglomerates. In this aggregate state, the fatty acid diamide is difficult to assume a needle-like form (i.e., is difficult to activate). However, the inventors of the present invention posit that by using a viscosity adjuster that is a mixture obtained by melt-mixing at least two types of diamide compounds with different chain lengths, and that contains a diamide compound obtained using hydrogenated castor oil fatty acid, the fatty acid diamide becomes more easily activated as a result of the interaction between the respective components.

Furthermore, in the case of (iii) above, it has been found that the use of the viscosity modifier of the present invention not only provides a sufficient viscosity-imparting effect, but also alleviates the impediment to overcoatability caused by an increase in the contact angle of a coating film formed using a non-aqueous paint with a reduced amount of organic solvent. In other words, even in the case of (iii) above, the viscosity modifier of the present invention can achieve both a sufficient viscosity-imparting effect and an alleviation effect of impediment to overcoatability.

Paints are generally applied in multiple layers for purposes such as surface protection, adding design and functionality. For example, in marine or heavy-duty anti-corrosion paints, two coats of paint are often applied, followed by another coat of paint on top, to increase corrosion protection by thickening the paint film. In such cases, poor adhesion at the interface between each coat can cause the paint to peel off.

Here, fatty acid diamides, which are made by reacting hydrogenated castor oil fatty acids or straight-chain saturated fatty acids with diamines, have low surface tension and can bleed onto the surface of non-aqueous paints after application. For example, when a solvent-containing paint is applied, convection occurs within the paint film during curing due to the evaporation of the solvent after application, making the fatty acid diamides particularly susceptible to bleeding. Furthermore, when a solvent-free paint is applied, convection occurs within the paint film due to the settling of pigments and fillers after application and before curing, which can cause the fatty acid diamides to bleed. This bleeding of the fatty acid diamides results in a larger contact angle of the paint film. When the contact angle of the paint film increases, droplets of another paint applied to the surface of the cured paint film do not wet and spread, reducing the contact area at the paint film interface, reducing interlayer adhesion and hindering the paint film's recoatability. This increases the risk of the recoat film peeling.

In response to this, by adding the viscosity modifier of the present invention to non-aqueous paints, it is possible to alleviate the problem of impaired recoatability of the coating film caused by an increase in the coating film contact angle as described above.

(Diamide Compound (A))
The diamide compound (A) is an essential component of the viscosity modifier according to the present invention, and is a diamide (fatty acid diamide) obtained by condensing a diamine component (A-a) with a monocarboxylic acid component (A-c). Raw materials for obtaining the diamide compound (A) according to the present invention include the diamine component (A-a) and a monocarboxylic acid component (A-c) selected from the group consisting of hydrogenated castor oil fatty acids (hereinafter sometimes referred to as "oxy acids" or "OX acids"), saturated fatty acids, and unsaturated fatty acids. Examples of the diamine component (A-a) and the monocarboxylic acid component (A-c) include the compounds exemplified below. The conditions for the condensation reaction (e.g., reaction temperature, compounding ratio of each component) can be appropriately determined using known methods.

<Diamine Component (A-a)>
The diamine component (A-a) according to the present invention can be, for example, one or more diamines selected from the group consisting of diamines having 2 to 12 carbon atoms. Examples of such diamines include aliphatic diamines such as ethylenediamine (EDA), propylenediamine, tetramethylenediamine (TMDA), hexamethylenediamine (HMDA), octamethylenediamine (OMDA), and dodecamethylenediamine (DMDA); aromatic diamines such as orthoxylenediamine, metaxylenediamine (MXDA), paraxylenediamine (PXDA), diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenyl sulfone, and methylenebischloroaniline; and alicyclic diamines such as piperazine and isophoronediamine.

<Monocarboxylic Acid Component (Ac)>
The monocarboxylic acid component (A-c) of the present invention can be a monocarboxylic acid selected from the group consisting of hydroxy acids, saturated fatty acids, and unsaturated fatty acids. Examples of hydroxy acids (hydrogenated castor oil fatty acids) include fatty acids having a hydroxy group, such as 12-hydroxystearic acid obtained by saponifying hydrogenated castor oil. Examples of saturated fatty acids include saturated aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid (behenic acid), 2-ethylhexanoic acid, isostearic acid, cyclopentanoic acid, cyclohexanoic acid, and cycloheptanoic acid. Examples of unsaturated fatty acids include unsaturated aliphatic monocarboxylic acids such as oleic acid, linoleic acid, ricinoleic acid, linolenic acid, eicosenoic acid, erucic acid, and mixed fatty acids obtained from natural fats and oils (tall oil fatty acid, rice bran fatty acid, soybean oil fatty acid, beef tallow fatty acid, etc.).

In order to enhance the aforementioned viscosity-imparting effect and the effect of improving topcoatability inhibition, it is preferable that the monocarboxylic acid component (A-c) contains at least a straight-chain saturated fatty acid (a) (hereinafter, straight-chain saturated fatty acid may be referred to as "alkanoic acid"). Examples of straight-chain saturated fatty acid (a) include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid.

Furthermore, from another perspective of enhancing the viscosity-imparting effect and the effect of improving overcoatability inhibition, the monocarboxylic acid component (A-c) is preferably a monocarboxylic acid having 2 to 18 carbon atoms, more preferably a monocarboxylic acid having 2 to 14 carbon atoms, and even more preferably a monocarboxylic acid having 2 to 12 carbon atoms.

<Method for synthesizing diamide compound (A)>
The diamide compound (A) according to the present invention can be obtained by adding the diamine component (A-a) to the monocarboxylic acid component (A-c) in an amount that is half the amount of the monocarboxylic acid component (A-c) (i.e., 1 molar equivalent per 2 molar equivalents of the monocarboxylic acid component (A-c)), and carrying out a condensation polymerization (amidation) reaction at 150 to 200°C. For example, the diamine component (A-a) and the monocarboxylic acid component (A-c) as raw materials are placed in a reaction vessel such as a four-necked flask, and the raw materials are stirred in an inert gas atmosphere (e.g., under a nitrogen gas flow) to form a mixture. The raw material mixture is then heated and subjected to a condensation polymerization reaction at 150 to 200°C for 4 to 10 hours, thereby synthesizing the diamide compound (A).

(Diamide Compound (B))
The diamide compound (B) is an essential component of the viscosity modifier according to the present invention, and is a diamide (fatty acid diamide) obtained by condensing a diamine component (Ba) with a monocarboxylic acid component (Bc). Raw materials for obtaining the diamide compound (B) according to the present invention include the diamine component (Ba) and a monocarboxylic acid component (Bc) selected from the group consisting of hydroxy acids, saturated fatty acids, and unsaturated fatty acids. Examples of the diamine component (Ba) and the monocarboxylic acid component (Bc) include the compounds exemplified below. The conditions for the condensation reaction (e.g., reaction temperature, compounding ratio of each component) can be appropriately set using known methods.

<Diamine Component (Ba)>
As the diamine component (Ba) according to the present invention, the same diamines as those used as the diamine component (Aa) described above can be used.

In order to enhance the viscosity-imparting effect and the effect of improving overcoatability inhibition, it is preferable that diamine component (A-a) and diamine component (B-a) are the same type of diamine.

<Monocarboxylic acid component (B-c)>
As the monocarboxylic acid component (Bc) according to the present invention, the same monocarboxylic acids as those used as the monocarboxylic acid component (Ac) described above can be used.

In order to enhance the aforementioned viscosity-imparting effect and the effect of improving overcoatability inhibition, it is preferable that the monocarboxylic acid component (B-c) contains at least a straight-chain saturated fatty acid (b). Examples of the straight-chain saturated fatty acid (b) are the same as the examples of the straight-chain saturated fatty acid (a) described above.

Furthermore, from another perspective of enhancing the viscosity-imparting effect and the effect of improving inhibition of overcoatability, it is preferable that the monocarboxylic acid component (B-c) be a monocarboxylic acid having 2 to 18 carbon atoms.

In the viscosity modifier of the present invention, in order to achieve a sufficient viscosity-imparting effect and an effect of improving overcoatability inhibition, the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) must be monocarboxylic acids with different numbers of carbon atoms. If the number of carbon atoms in the monocarboxylic acid component (A-c) and the number of carbon atoms in the monocarboxylic acid component (B-c) are the same, the sufficient viscosity-imparting effect and effect of improving overcoatability inhibition intended by the present invention cannot be achieved.

In order to enhance the viscosity-imparting effect and the effect of improving topcoatability inhibition, it is preferable that the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) be 16 or less. There is no particular lower limit for the difference in carbon number, and the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) may be 1. In order to further enhance the viscosity-imparting effect and the effect of improving topcoatability inhibition, it is more preferable that the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) be 1 or more and 14 or less, even more preferably 1 or more and 12 or less, even more preferably 1 or more and 10 or less, and most preferably 1 or more and 8 or less. Note that, when an oxyacid is used as the monocarboxylic acid component (A-c) or the monocarboxylic acid component (B-c), the "difference in carbon number" referred to here refers to the difference in carbon number of the monocarboxylic acid other than the oxyacid. For example, in the viscosity modifier of Production Example 1 listed in the Examples below, the difference in the number of carbon atoms between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) is the difference between the number of carbon atoms of acetic acid (C2), a monocarboxylic acid other than the oxyacid used in Synthesis Example A1, and the number of carbon atoms of caproic acid (C6), a monocarboxylic acid used in Synthesis Example B1, and is therefore 4. When multiple monocarboxylic acids other than oxyacids are used as the monocarboxylic acid component (A-c) or the monocarboxylic acid component (B-c), the difference in the number of carbon atoms between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) will be multiple. Furthermore, in the present invention, when there are multiple differences in the number of carbon atoms between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c), if at least one of the differences in the number of carbon atoms is not 0 (zero), the number of carbon atoms of the monocarboxylic acid component (A-c) and the number of carbon atoms of the monocarboxylic acid component (B-c) are considered to be different from each other. For example, when hydrogenated castor oil fatty acid and acetic acid are used as the monocarboxylic acid component (A-c), and caproic acid and lauric acid are used as the monocarboxylic acid component (B-c), the difference in carbon number can be either 4 or 10. In this case, it is presumed that the viscosity-imparting effect and the effect of improving overcoatability inhibition depend on the molar fraction of caproic acid and lauric acid. For example, when the compounding ratio of the monocarboxylic acid component (B-c) is 60 mol% caproic acid and 40 mol% lauric acid, it is thought that the effect when the difference in carbon number is 4 contributes to 60% of the overall effect, and the effect when the difference in carbon number is 10 contributes to 40% of the overall effect. Furthermore, when hydrogenated castor oil fatty acid and acetic acid are used as the monocarboxylic acid component (A-c), and acetic acid and caproic acid are used as the monocarboxylic acid component (B-c), the difference in carbon number can be either 0 or 4. In this case, the difference in carbon number may not be zero, so the number of carbon atoms in the monocarboxylic acid component (A-c) and the number of carbon atoms in the monocarboxylic acid component (B-c) can be said to be different. In this case, too, the contribution of the effect differs depending on the molar fraction of acetic acid and caproic acid in the monocarboxylic acid component (B-c). Therefore, the smaller the molar fraction of caproic acid, the smaller its contribution to the effect.

<Method for synthesizing diamide compound (B)>
The diamide compound (B) according to the present invention can be synthesized by the same method as that for the diamide compound (A) described above.

(Diamide Compound (C))
The diamide compound (C) is an optional component of the viscosity modifier according to the present invention and is a diamide (fatty acid diamide) obtained by condensing a diamine component (Ca) and a monocarboxylic acid component (C-c). One or more fatty acid diamides can be used as the diamide compound (C) contained in the mixture (M). However, the diamide compound (C) is a fatty acid diamide different from both the diamide compound (A) and the diamide compound (B). The raw materials for obtaining the diamide compound (C) according to the present invention include the diamine component (Ca) and a monocarboxylic acid component (C-c) selected from the group consisting of hydroxy acids, saturated fatty acids, and unsaturated fatty acids. Examples of the diamine component (Ca) and the monocarboxylic acid component (C-c) include the compounds exemplified below. The conditions for the condensation reaction (e.g., reaction temperature, compounding ratio of each component) can be appropriately determined using known methods.

<Diamine Component (Ca)>
As the diamine component (Ca) according to the present invention, the same diamines as those used as the diamine component (Aa) described above can be used.

Here, in order to enhance the aforementioned viscosity-imparting effect and the effect of improving overcoatability inhibition, it is preferable that diamine component (Ca) be the same type of diamine as diamine component (Aa) and diamine component (Ba).

<Monocarboxylic acid component (C-c)>
As the monocarboxylic acid component (Cc) according to the present invention, the same monocarboxylic acids as those used as the monocarboxylic acid component (Ac) described above can be used.

However, the number of carbon atoms in the monocarboxylic acid component (C-c) is not particularly limited, and may be the same as or different from the number of carbon atoms in the monocarboxylic acid component (A-c) or the monocarboxylic acid component (B-c). Furthermore, the monocarboxylic acid component (C-c) may or may not contain an alkanoic acid.

On the other hand, to enhance the viscosity-imparting effect and the effect of improving overcoatability inhibition, it is preferable that the monocarboxylic acid component (C-c) be a monocarboxylic acid having 2 to 18 carbon atoms.

In the viscosity modifier of the present invention, at least one of the monocarboxylic acid component (A-c), monocarboxylic acid component (B-c), and monocarboxylic acid component (C-c) must contain hydrogenated castor oil fatty acid. In other words, the mixture (M) must contain a diamide compound obtained using hydrogenated castor oil fatty acid as the monocarboxylic acid component. Otherwise, the intended viscosity-imparting effect and the effect of improving overcoatability will not be fully achieved.

A typical case in which the viscosity modifier of the present invention contains a diamide compound (C) is when neither the monocarboxylic acid component (A-c) nor the monocarboxylic acid component (B-c) contains hydrogenated castor oil fatty acid, and when the monocarboxylic acid component (C-c) contains a diamide compound (C) containing hydrogenated castor oil fatty acid. However, the cases in which the viscosity modifier of the present invention contains a diamide compound (C) are not limited to the above cases.

<Method for synthesizing diamide compound (C)>
The diamide compound (C) according to the present invention can be synthesized by the same method as that for the diamide compound (A) described above.

(Mixing ratio of diamide compound (A) to diamide compound (B))
The mixing ratio of the diamide compound (A) to the diamide compound (B), which are contained as essential components in the mixture (M) (hereinafter, this may also be read as the "blending ratio" during the production of the viscosity modifier), is not particularly limited. For example, the mixing ratio of the diamide compound (A) to the diamide compound (B) (hereinafter, this may be referred to as the "mixing ratio A/B") can be 99/1 to 1/99. From the viewpoint of enhancing the viscosity-imparting effect and the effect of improving the inhibition of overcoatability, the mixing ratio A/B is preferably 95/5 to 5/95. Furthermore, from the viewpoint of further enhancing the viscosity-imparting effect and the effect of improving the inhibition of overcoatability, when the monocarboxylic acid component (A-c) contains hydrogenated castor oil fatty acid and the monocarboxylic acid component (B-c) does not contain hydrogenated castor oil fatty acid and does not contain the diamide compound (C), the mixing ratio A/B is preferably 95/5 to 55/45. In order to further enhance the viscosity-imparting effect and the effect of improving inhibition of overcoatability, the mixing ratio A/B is more preferably 95/5 to 60/40, even more preferably 95/5 to 70/30 or 90/10 to 60/40, even more preferably 90/10 to 70/30, and most preferably 80/20 to 70/30.

(Amount of Diamide Compound (C) Mixed)
The amount of diamide compound (C) mixed in the viscosity modifier of the present invention (hereinafter, in this specification, this may also be read as the "blended amount" during production of the viscosity modifier) is not particularly limited, and may be, for example, more than 0 parts by mass and not more than 900 parts by mass per 100 parts by mass of the total amount of diamide compound (A) and diamide compound (B). From the viewpoint of enhancing the viscosity-imparting effect and the effect of improving inhibition of overcoatability, the amount of diamide compound (C) mixed is preferably more than 0 parts by mass and not more than 400 parts by mass, more preferably 100 parts by mass or more and not more than 200 parts by mass per 100 parts by mass of the total amount of diamide compound (A) and diamide compound (B).

(Other Components (D))
The mixture (M) may contain a component (D) other than the diamide compound (A), diamide compound (B), and diamide compound (C) described above, as long as the effects of the present invention are not impaired. Examples of such component (D) include polyamide, hydrogenated castor oil, and other polymers. The amount of component (D) contained in the viscosity modifier of the present invention (hereinafter, this may also be interpreted as the "blended amount" during the production of the viscosity modifier) is not particularly limited, and may be, for example, more than 0 parts by mass and not more than 900 parts by mass per 100 parts by mass of the diamide compound (A), diamide compound (B), and diamide compound (C). From the viewpoint of enhancing the effect of adding component (D), the amount of component (D) is preferably more than 0 parts by mass and not more than 400 parts by mass, more preferably 1 part by mass or more and not more than 50 parts by mass per 100 parts by mass of the diamide compound (A), diamide compound (B), and diamide compound (C).

<Polyamide>
The polyamide is a polyamide obtainable by polycondensation of an amine component and a carboxylic acid component. In the present invention, the amine component includes, for example, at least one amine selected from the group consisting of diamines having 2 to 54 carbon atoms and triamines having 2 to 54 carbon atoms. The carboxylic acid component includes, for example, at least one carboxylic acid selected from dicarboxylic acids having 4 to 54 carbon atoms and tricarboxylic acids having 4 to 54 carbon atoms. The polyamide usable as component (D) of the present invention can be any polyamide having any chemical structure, as long as it is a polymer compound obtainable by polycondensation of the above-mentioned amine component and carboxylic acid component and has an amide bond (—CONH—).

The amine component can be, for example, at least one amine selected from the group consisting of diamines having 2 to 54 carbon atoms and triamines having 2 to 54 carbon atoms. Examples of the diamines include aliphatic diamines such as ethylenediamine (EDA), propylenediamine, tetramethylenediamine (TMDA), hexamethylenediamine (HMDA), octamethylenediamine (OMDA), and dodecamethylenediamine (DMDA); aromatic diamines such as orthoxylenediamine, metaxylenediamine (MXDA), paraxylenediamine (PXDA), diaminodiphenylmethane, diaminodiphenylether, diaminodiphenylsulfone, and methylenebischloroaniline; and alicyclic diamines such as piperazine and isophoronediamine. Examples of the triamines include aliphatic triamines such as diethylenetriamine.

Furthermore, the amine component can also be a diamine or triamine derived from polymerized fatty acid, which is a polymerized fatty acid derivative. Examples of such polymerized fatty acid derivatives include dimer diamine (DDA), which is a derivative of dimer acid (described in detail below), and trimer triamine (TTA), which is a derivative of trimer acid (described in detail below). Dimer diamine is a dimer acid derivative in which the two terminal carboxyl groups of a dimer acid are substituted with primary aminomethyl groups or amino groups, and commercially available products can be used. Trimer triamine is a trimer acid derivative in which the three terminal carboxyl groups of a trimer acid are substituted with primary aminomethyl groups or amino groups, and commercially available products can be used.

As the amine component, a monoamine may be used in combination with the diamine and/or triamine described above. Examples of monoamines that can be used as the amine component include ethylamine, monoethanolamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, decylamine, laurylamine, myristylamine, cetylamine, stearylamine, and behenylamine.

Each of the compounds used as the amine components described above can be used alone or in combination of two or more.

The carboxylic acid component can be, for example, at least one carboxylic acid selected from dicarboxylic acids having 4 to 54 carbon atoms and tricarboxylic acids having 4 to 54 carbon atoms. Examples of dicarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and dimer acid. Dimer acids are polymerized fatty acids obtained by polymerizing (dimerizing) unsaturated fatty acids (e.g., unsaturated fatty acids having 18 or 22 carbon atoms) obtained from vegetable oils such as soybean oil, tall oil, linseed oil, and cottonseed oil. Dimer acids having 36 or 44 carbon atoms are generally commercially available. Commercially available dimer acids contain monomeric and trimer acids in addition to dimer acids, but those with a high dimer acid content are preferred.

Furthermore, examples of the tricarboxylic acid include trimer acid and trimesic acid. Trimer acid is a polymerized fatty acid that has been made by dimer acid-based purification such as distillation to increase the trimer acid content, and trimer acid with 54 carbon atoms is generally commercially available. Commercially available trimer acids contain monomer acid and dimer acid in addition to trimer acid, but those with a high trimer acid content are preferred.

In addition, as the carboxylic acid component, a monocarboxylic acid may be used in combination with the above-mentioned dicarboxylic acid and/or tricarboxylic acid. Examples of monocarboxylic acids that can be used as the carboxylic acid component include saturated aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated castor oil fatty acid, arachidic acid, and behenic acid, as well as unsaturated aliphatic monocarboxylic acids such as oleic acid, linoleic acid, ricinoleic acid, linolenic acid, eicosenoic acid, erucic acid, and mixed fatty acids obtained from natural fats and oils (tall oil fatty acid, rice bran fatty acid, soybean oil fatty acid, beef tallow fatty acid, etc.).

Each of the compounds used as the carboxylic acid component described above can be used alone or in combination of two or more.

The polyamides usable in the present invention can be synthesized by subjecting the above-mentioned amine component and carboxylic acid component to a polycondensation reaction under known reaction conditions. For example, the raw materials, the amine component and carboxylic acid component, are placed in a reaction vessel such as a four-necked flask, and the raw materials are stirred in an inert gas atmosphere (e.g., under a nitrogen gas flow) to form a mixture. The raw material mixture is then heated and subjected to a polycondensation reaction at 150°C to 200°C for 2 to 10 hours, synthesizing the polyamide.

<Hydrogenated castor oil>
Hydrogenated castor oil is a triglyceride of saturated fatty acids obtained by hydrogenating castor oil. Commercially available hydrogenated castor oils can be used, and examples of such products include C-Wax (manufactured by Kokura Synthetic Industries, Ltd.), Kaowax 85P (manufactured by Kao Corporation), Castor Hydrogenated Oil A (manufactured by Ito Oil Mills, Ltd.), Castor Hydrogenated Oil (manufactured by Yamakei Sangyo Co., Ltd.), and Royal Castor Products' Hydrogenated Castor Oil "B" Grade.

<Other polymers>
Examples of other polymers include ethylene acrylic acid copolymer, polyethylene oxide, maleic anhydride modified polyethylene, maleic anhydride modified polypropylene, polyurea, ethylene-vinyl acetate copolymer, poly(meth)acrylic acid, and (meth)acrylic acid copolymer.

(Properties of viscosity modifier)
The viscosity modifier according to the present invention is a powdered (fine powder) viscosity modifier obtained by atomizing the mixture (M). The size of the powdered viscosity modifier is not particularly limited, but may be adjusted to, for example, a median diameter of approximately 0.1 to 100 μm. As the viscosity modifier of the present invention, a powdered viscosity modifier may be used as is, or a liquid or paste-like viscosity modifier obtained by dispersing or dissolving a powdered viscosity modifier in a solvent may be used. Therefore, for example, when the viscosity modifier of the present invention is added to a curable composition or a non-aqueous coating composition described below, the powdered viscosity modifier may be kneaded with the base polymer and other components of the sealant, or the liquid or paste-like viscosity modifier may be kneaded with the base polymer and other components of the sealant.

(Method for producing viscosity modifier)
The method for producing the viscosity modifier according to the present invention described above includes the mixing step and the atomization step described below.

<Mixing process>
In the mixing step, two or more compounds (including at least the diamide compound (A) and the diamide compound (B) as essential components, the diamide compound (C) as an optional component, and optionally other components (D) are melt-mixed to obtain a molten mixture (M). Specifically, for example, some of the components, such as the diamide compound (A) and the diamide compound (B), are heated to a molten state, and then the remaining components are added and melt-mixed. The melting temperature at this time may be set to be equal to or higher than the melting points of all the components contained in the mixture (M).

<Atomization process>
In the atomization step, the mixture (M) obtained in the above-mentioned mixing step is atomized to obtain a powdered viscosity modifier, or a liquid or paste-like viscosity modifier in which the powdered viscosity modifier is dispersed or dissolved in a solvent. The atomization method is not particularly limited, but for example, a powdered viscosity modifier is produced by extracting the molten mixture (M) obtained in the mixing step as a solid and pulverizing the solid mixture (M) to the desired particle size. Known methods can be used to pulverize the solid mixture (M), such as a jet mill. Another atomization method involves adding the molten mixture (M) obtained in the mixing step to a precipitation medium such as an organic solvent, a low-viscosity polymer, or a resin solution (varnish), and precipitating the finely powdered mixture (M) in the precipitation medium, thereby producing a liquid or paste-like viscosity modifier. The organic solvent, low-viscosity polymer, or resin solution (varnish) that can be used as the precipitation medium is not particularly limited, but the following examples can be used.

Examples of organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, 1-butanol (n-butanol), 2-butanol, 1-pentanol, octyl alcohol, benzyl alcohol, glycerin, ethylene glycol, and propylene glycol; carboxylic acids such as acetic acid; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; aromatic hydrocarbons such as toluene and xylene; amides such as dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, and acetanilide; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; halogens such as methylene chloride and chloroform; carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl butyrate, and propylene glycol monomethyl ether acetate (PMA); ethers such as propylene glycol monomethyl ether (PM); acetonitrile, propionitrile, and the like. The above organic solvents may be used alone or in combination of two or more.

Examples of low-viscosity polymers include polyalphaolefins, polyalkylene oxides, polyesters, epoxy resins, urethane resins, acrylic resins, aliphatic or aromatic high-boiling oils, phenol-modified aliphatic or aromatic polymers, xylene resins, and toluene resins, all of which have a viscosity of 1 to 200 cps at 25°C and a heating residue of 90% or more.

Examples of resin solutions include solutions obtained by diluting alkyd resin, acrylic resin, acrylic urethane resin, melamine resin, urethane resin, epoxy resin, coumarone resin, urea resin, phenolic resin, vinyl chloride resin, phenoxy resin, silicone resin, fluororesin, nylon resin, styrene butadiene resin, nitrile butadiene resin, petroleum resin, rosin, drying oil, boiled oil, acetyl cellulose, nitrocellulose, etc. with an organic solvent.

(Uses of viscosity adjusters)
The viscosity modifier according to the present invention is suitable for use as an additive in curable compositions, which will be described later, or non-aqueous paint compositions such as marine or heavy-duty anticorrosion paints.

[Curable composition]
The curable composition of the present invention contains the above-mentioned viscosity modifier and a resin component as essential components. The curable composition of the present invention may further contain, as optional components, a plasticizer, a filler, and other additives such as a dehydrating agent and an adhesion promoter. The content of the viscosity modifier of the present invention varies depending on the type of resin component in the curable composition and the blending composition of fillers such as pigments. However, it is typically 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, per 100 parts by mass of the total resin solids in the curable composition. By setting the content of the viscosity modifier within the above range, the fatty acid diamide can be sufficiently activated and a sufficient viscosity-imparting effect can be obtained even under conditions such as (i) and (ii) above, in which the fatty acid diamide is unlikely to swell and a sufficient viscosity-imparting effect is unlikely to be exhibited. Furthermore, depending on the blending composition of the curable composition according to the present invention and the composition of the viscosity modifier according to the present invention, even under conditions in which the components of the curable composition are kneaded at room temperature (for example, about 25°C, which is even lower than the cold process of (ii)), the fatty acid diamide can be sufficiently activated and a sufficient viscosity-imparting effect can be obtained.

(Resin component)
Examples of the resin component of the curable composition of the present invention include modified silicone resins. Modified silicone resins are primarily composed of silyl-terminated polyethers (e.g., polyoxyalkylenes) with reactive silyl groups introduced at the terminals. Sealants using such modified silicone resins as the base polymer are called modified silicone sealants. For example, when modified silicone resins are used as the resin component of curable compositions such as sealants, the modified silicone resins preferably cure in the presence of moisture to form siloxane bonds. Examples of modified silicone resins include silyl-modified polymers formed by introducing silyl groups into the hydroxyl terminals of a linear or branched polyoxyalkylene polymer as the main chain. Other examples of silyl-modified polymers include silyl-modified polyurethanes, silyl-modified polyesters, and silyl-terminated polyisobutylenes. Modified silicone resins may be obtained by known synthesis methods or may be commercially available products. Commercially available modified silicone resins include, for example, MS Polymer S203H and MS Polymer S303H manufactured by Kaneka Corporation, and Exestar manufactured by AGC.

Another example of a resin component of a curable composition is a (meth)acrylic polymer containing a hydrolyzable silyl group (hereinafter referred to as a "silylated (meth)acrylate polymer"). A silylated (meth)acrylate polymer is a resin in which the main chain of a modified silicone resin has been changed from polyoxyalkylene to a (meth)acrylic polymer. A sealant using this silylated (meth)acrylate polymer as the base polymer is called a silylated acrylate sealant. Note that "(meth)acrylic" and "(meth)acrylate" mean "acrylic or methacrylic" and "acrylate or methacrylate," respectively. Using a silylated (meth)acrylate polymer as the base polymer of a sealant can impart high weather resistance and high heat resistance to the sealant. Therefore, a silylated acrylate sealant can be used for a long period of time, extending the maintenance period and reducing the environmental impact. The silylated (meth)acrylate polymer may be obtained by a known synthesis method, or may be a commercially available product. Examples of commercially available silylated (meth)acrylate polymers include TA Polymer SB802S manufactured by Kaneka Corporation, ARUFON (registered trademark) US-6000 series (manufactured by Toagosei Co., Ltd.), and Actflow (registered trademark) series (manufactured by Soken Chemical & Engineering Co., Ltd.).

The resin component of the curable composition may contain other resins in addition to the modified silicone resin or silylated (meth)acrylate polymer described above, as long as the effects of the present invention are not impaired.

(Plasticizer)
Examples of plasticizers include dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), diheptyl phthalate (DHP), dioctyl phthalate (DOP), diisononyl phthalate (DINP), isononyl 1,2-cyclohexanedicarboxylate (DINCH), diisodecyl phthalate (DIDP), ditridecyl phthalate (DTDP), butyl benzyl phthalate (BBP), Dicyclohexyl phthalate (DCHP), tetrahydrophthalic acid esters, dioctyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), di-n-alkyl adipates, dibutyl diglycol adipate (BXA), bis(2-ethylhexyl) azelaate (DOZ), dibutyl sebacate (DBS), dioctyl sebacate (DOS), dibutyl maleate ( DBM), di-2-ethylhexyl maleate (DOM), dibutyl fumarate (DBF), tricresyl phosphate (TCP), triethyl phosphate (TEP), tributyl phosphate (TBP), tris(2-ethylhexyl)phosphate (TOP), tri(chloroethyl)phosphate (TCEP), trisdichloropropyl phosphate (CRP), tributoxyethyl phosphate (TBXP), tris(β-chloropropyl)phosphate (TMCPP), triphenyl phosphate (TPP), octyldiphenyl phosphate (CDP), acetyltriethyl citrate, acetyltributyl citrate, trimellitic acid-based plasticizers, polyester-based plasticizers, polyether-based plasticizers, epoxy-based plasticizers, chlorinated paraffin, stearic acid-based plasticizers, dimethylpolysiloxane, process oil, and the like.

(filler)
Examples of fillers include extender pigments such as calcium carbonate (heavy calcium carbonate (GCC), precipitated calcium carbonate (PCC), etc.), barium sulfate, silicon dioxide, aluminum hydroxide, talc, organic fibers, and glass powder; color pigments such as titanium dioxide, carbon black, yellow lead, cadmium yellow, ochre, titanium yellow, zinc chromate, red iron oxide, aluminosilicate, quinacridone-based, phthalocyanine-based, anthroquinone-based, diketopyrrolopyrrole-based, benzimidazolone-based, and isoindolinone-based; and metallic pigments such as aluminum flakes, copper flakes, micaceous iron oxide, mica, and scaly powder of mica coated with a metal oxide.

(Other additives)
The curable composition of the present invention may contain other substances, such as dehydrating agents (e.g., silane coupling agents), adhesion improvers, surfactants, curing catalysts, film-forming aids, driers, antifouling agents, sensitizers, antioxidants, light stabilizers, ultraviolet absorbers, water-resistant agents, antiseptics and antifungal agents, antifoaming agents, leveling agents, dispersants, flame retardants, antistatic agents, release agents, deodorizers, and fragrances, within the scope of not impairing the properties of the curable composition of the present invention or the object of the present invention.

(Method for producing curable composition)
The curable composition of the present invention can be produced in accordance with known sealant production methods. For example, the curable composition of the present invention is produced by mixing the above-mentioned resin components, plasticizer, filler, viscosity modifier, and other components using a three-roll mill or dissolver, followed by kneading under reduced pressure while heating. The kneading temperature can be appropriately set depending on the equipment used in production, production costs, allowable energy consumption, and other factors. The curable composition of the present invention may also be produced by kneading the components at room temperature (e.g., about 20 to 30°C) without heating. Therefore, with a curable composition containing a viscosity modifier of the present invention, the viscosity-imparting effect can be achieved by kneading the components at room temperature (about 25°C), even in warm regions where a temperature rise due to the heat generated by the dispersion of the components can degrade the quality, or where heat cannot be obtained. Furthermore, in cold regions, the viscosity-imparting effect can be achieved even in cold regions where the temperature is about 0°C and the temperature only rises to about 20 to 30°C during kneading, even if heat is generated during the dispersion of the components.

(Uses of the curable composition)
The cured product of the curable composition of the present invention can be used as a sealant for buildings, ships, automobiles, roads, medical equipment, etc.

[Non-aqueous paint composition]
The non-aqueous paint composition of the present invention contains the above-mentioned viscosity modifier and a resin component as essential components. The amide-based viscosity modifier is activated by heating and dispersing in the non-aqueous paint, thereby exhibiting a viscosity-imparting effect. However, the degree of activation is affected by the paint formulation and heat-dispersion conditions (temperature, dispersion shear, dispersion time, etc.). On the other hand, when the paint formulation and heat-dispersion conditions are the same, the ease of activation is determined by the viscosity modifier composition, so the effects of the present invention are not limited by the content of viscosity modifier in the paint. However, if the content of viscosity modifier in the paint is too low, the viscosity modifier's effect as a viscosity modifier is weak. On the other hand, if the content of viscosity modifier in the paint is too high, the paint will thicken significantly, making dispersion of the viscosity modifier in the paint, and handling and application of the paint difficult. Therefore, the content of viscosity modifier in the non-aqueous paint composition is preferably 0.2% to 5% by mass. Furthermore, by setting the content of the viscosity modifier within the above range, it is possible to achieve both the effect of imparting viscosity and the effect of improving overcoating inhibition, even in the case of (iii) above.

The non-aqueous paint composition of the present invention is an ultra-high solids paint or a solvent-free paint. An ultra-high solids paint is a paint in which the content of volatile solvents in the paint has been reduced to the minimum possible extent. In this invention, a paint in which the content of volatile solvents in the paint is 15 mass% or less based on the total amount of the non-aqueous paint composition is referred to as an "ultra-high solids paint." Solvent-free paints are paints that do not contain volatile solvents (organic solvents, etc.) to dissolve the resin in the paint, and have the advantage of contributing to low VOCs because there is no need to volatilize the solvent when forming a paint film. Furthermore, because they do not contain volatile solvent components, the applied thickness is almost the same as the thickness after drying, making them suitable for painting areas where a large paint film thickness is desired.

In general, as mentioned above, "solvent-free paint" refers to paint that does not contain volatile solvents, but it may also contain liquid components (components that remain in the paint film) such as reactive organic media such as reactive diluents, non-reactive organic media such as non-reactive diluents, and silane coupling agents, as necessary. Therefore, in this invention, "solvent-free paint" includes not only completely solvent-free paints that are completely free of liquid components that can function as solvents, but also paints that contain the above-mentioned components that remain in the paint film and do not contain volatile solvents.

(solvent)
The solvent in the present invention, that is, the volatile solvent for dissolving the resin in the paint, may be, for example, an organic solvent, and is not particularly limited as long as it is used in the field of paints. Examples of organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, 1-butanol (n-butanol), 2-butanol, 1-pentanol, octyl alcohol, benzyl alcohol, glycerin, ethylene glycol, and propylene glycol; carboxylic acids such as acetic acid; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; aromatic hydrocarbons such as toluene and xylene; amides such as dimethyl sulfoxide, N,N-dimethylformamide, dimethylacetamide, and acetanilide; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; halogens such as methylene chloride and chloroform; carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, and diethyl carbonate; esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl butyrate, and propylene glycol monomethyl ether acetate (PMA); ethers such as propylene glycol monomethyl ether (PM); acetonitrile, propionitrile, and the like. The above-mentioned solvents may be used alone or in combination of two or more kinds.

(organic medium)
In the non-aqueous coating composition containing the solvent of the present invention (solvent-containing coating), an organic medium containing a reactive functional group or a non-reactive organic medium may be used in combination with the above-mentioned solvent.

Examples of organic media containing reactive functional groups include acrylates such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and phenyl glycidyl ether acrylate; urethane prepolymers such as hexamethylene diisocyanate urethane prepolymer and phenyl glycidyl ether acrylate toluene diisocyanate urethane prepolymer; n-butyl glycidyl ether, 2-ethylhexyl Examples of glycidyl ethers include alkyl glycidyl ether, alkyl (C8-C18) glycidyl ether (alkyl glycidyl ethers with an alkyl chain length of C8-C18, i.e., alkyl glycidyl ethers with an alkyl group containing 8 to 18 carbon atoms), glycidyl ether of stearic acid, styrene oxide, phenyl glycidyl ether, nonylphenyl glycidyl ether, butylphenyl glycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, and diethylene glycol diglycidyl ether; chlorostyrene, methoxystyrene, butoxystyrene, and vinylbenzoic acid. Among the above alkyl (C8-C18) glycidyl ethers, C12-C14 mixed alkyl glycidyl ethers (a mixture of alkyl glycidyl ethers with alkyl chain lengths of C12, C13, and C14, also known as "aliphatic glycidyl ether (C12-14)") and lauryl glycidyl ether are commonly used.

Furthermore, examples of suitable non-reactive organic media include petroleum resin-based organic media with a viscosity of 1 to 200 cps at 25°C and a heating residue of 90% or more. Examples of petroleum resin-based organic media include aliphatic or aromatic high-boiling oils, phenol-modified aliphatic or aromatic polymers, xylene resins, and toluene resins.

(Resin component)
The resin component of the non-aqueous coating composition of the present invention is not particularly limited as long as it is a resin conventionally used as a base resin for non-aqueous coatings, and various resins can be incorporated into the non-aqueous coating composition. Examples of base resins for non-aqueous coatings that can be used with the non-aqueous coating composition of the present invention include alkyd resins, acrylic resins, acrylic urethane resins, melamine resins, urethane resins, epoxy resins, coumarone resins, urea resins, phenolic resins, vinyl chloride resins, phenoxy resins, silicone resins, fluororesins, nylon resins, styrene-butadiene resins, nitrile-butadiene resins, petroleum resins, rosin, drying oil, boiled oil, acetyl cellulose, nitrocellulose, etc. These resins may be cured by a chemical reaction with or without a catalyst, such as heat-curable, ultraviolet-curable, electron beam-curable, oxidation-curable, photocation-curable, peroxide-curable, or acid/epoxy-curable resins. They may also be resins with a high glass transition point that form a coating simply by volatilizing the diluent without a chemical reaction. Examples of the curing agent include amino resins, melamine resins, isocyanate compounds, blocked isocyanate compounds, and epoxy compounds. Only one type of base resin may be used, or two or more types may be used in combination.

From the standpoint of film-forming properties, etc., the resin content in the non-aqueous coating composition is preferably 20 to 99.5 mass%.

(filler)
The non-aqueous coating composition of the present invention may further contain fillers such as extender pigments, color pigments, metallic pigments, etc., from the viewpoint of improving the appearance and properties of the coating film. Examples of fillers include extender pigments such as calcium carbonate (heavy calcium carbonate (GCC), precipitated calcium carbonate (PCC), etc.), barium sulfate, silicon dioxide, aluminum hydroxide, talc, organic fibers, and glass powder; color pigments such as titanium dioxide, carbon black, yellow lead, cadmium yellow, ochre, titanium yellow, zinc chromate, red iron oxide, aluminosilicate, quinacridone, phthalocyanine, anthroquinone, diketopyrrolopyrrole, benzimidazolone, and isoindolinone; and metallic pigments such as aluminum flakes, copper flakes, micaceous iron oxide, mica, and scaly powder of mica coated with a metal oxide.

The non-aqueous paint composition of the present invention does not necessarily need to contain a filler, but from the perspective of achieving the purpose of adding the filler, it is preferable that the content of the filler in the non-aqueous paint composition be 0.001 to 80 mass %.

(Other additives)
The non-aqueous coating composition of the present invention may contain other substances, such as dehydrating agents (e.g., silane coupling agents), adhesion improvers, surfactants, curing catalysts, plasticizers, film-forming aids, driers, antifouling agents, sensitizers, antioxidants, light stabilizers, ultraviolet absorbers, water-resistant agents, antiseptic and antifungal agents, antifoaming agents, leveling agents, dispersants, flame retardants, antistatic agents, release agents, deodorizers, fragrances, and other additives, provided that the properties of the non-aqueous coating composition and the objects of the present invention are not impaired.

(Method for producing non-aqueous coating composition)
The method for producing the non-aqueous coating composition of the present invention is not particularly limited, but the viscosity modifier may be added to the resin in advance, uniformly dispersed, and then blended with the remaining raw materials, or may be added and mixed together with various additives, solvents, and resins when preparing the non-aqueous coating composition. If the viscosity modifier is not sufficiently dispersed in the non-aqueous coating composition, the effects of the present invention may not be fully exhibited.

(Method of using non-aqueous coating composition)
The non-aqueous coating composition of the present invention can be used in the form of a dispersion, or can be used as a dried powdery non-aqueous coating composition after removing liquid components such as the solvent from the dispersion by drying treatment or the like.

The nonaqueous coating composition of the present invention can be applied to the surface of various substrates to a desired film thickness using known application methods, such as roller coating, brush coating, air spraying, airless spraying, electrostatic coating, etc. Furthermore, by curing the nonaqueous coating composition applied to the surface of a substrate, a coated article having a coating film made of the cured product of the nonaqueous coating composition can be obtained.

Examples of substrates include metal materials such as iron, aluminum, brass, copper, stainless steel, tinplate, zinc-plated steel, zinc alloys (Zn-Al, Zn-Ni, Zn-Fe, etc.), and plated steel; resins such as polyethylene resin, polypropylene resin, acrylonitrile-butadiene-styrene (ABS) resin, polyamide resin, acrylic resin, vinylidene chloride resin, polycarbonate resin, polyurethane resin, and epoxy resin, as well as plastic materials such as various FRPs; and inorganic materials such as glass, cement, and concrete, which may be surface-treated.

(Uses of non-aqueous coating compositions)
The non-aqueous paint composition of the present invention can be used, for example, as a marine paint or a heavy-duty anticorrosion paint, but is not limited to these uses and can be used in various applications to which non-aqueous paints are generally applicable.

The above describes preferred embodiments of the present invention, but the present invention is not limited to the above-described embodiments. In other words, it is understood that other embodiments or various modifications that a person skilled in the art could conceive within the scope of the invention described in the claims also fall within the technical scope of the present invention.

The present invention will be explained in more detail below with reference to examples. However, the present invention is in no way limited to these examples. Furthermore, "%" and "parts" in the examples refer to "% by mass" and "parts by mass" unless otherwise specified.

[Synthesis of diamide compound (A)]
The diamine component (A-a) and the monocarboxylic acid component (Ac) shown in Table 1 were reacted under a nitrogen gas flow at 190°C for 6 hours while removing the generated water, to obtain the diamide compounds (A) of Synthesis Examples A1 to A16.

[Synthesis of diamide compound (B)]
The diamine component (Ba) and the monocarboxylic acid component (Bc) shown in Table 2 were reacted under a nitrogen gas flow at 190°C for 6 hours while removing the generated water, to obtain the diamide compounds (B) of Synthesis Examples B1 to B12.

[Synthesis of diamide compound (C)]
The diamine component (Ca) and the monocarboxylic acid component (Cc) shown in Table 3 were reacted under a nitrogen gas flow at 190°C for 6 hours while removing the generated water, to obtain the diamide compound (C) of Synthesis Example C1.

[Preparation of other components (D)]
As shown in Table 4, in addition to the diamide compounds (A), (B), and (C), other components (D) were prepared, including Synthesis Example D1 and Component Examples D2 and D3.

(Synthesis Example D1: Polyamide 1)
Into a four-neck flask, as raw materials, 55.6g of ethylenediamine as an amine component, 472.2g of polymerized fatty acid A (see Table 5) as a carboxylic acid component, and 472.2g of polymerized fatty acid B (see Table 5) were added, and the mixture was heated under stirring in a nitrogen gas stream and reacted at 150 ° C for 1 hour. Then, the mixture was further reacted at 175 ° C for 2 hours to obtain polyamide 1 of Synthesis Example D1. The weight-average molecular weight of polyamide 1 was 7515, and the acid value was 82.4. The weight-average molecular weight of Synthesis Example D1 was calculated from the chromatogram measured by GPC based on the molecular weight of standard polystyrene as the weight-average molecular weight. The weight average molecular weight was measured using an "HLC-8320GPC" (trade name, manufactured by Tosoh Corporation) as the GPC measuring instrument and three columns, one "GPCKF-801" and two "GPCKF-802" (both trade names, manufactured by Shodex), under the conditions of a mobile phase of tetrahydrofuran, a measurement temperature of 40°C, a flow rate of 1 cc/min, and a detector of RI. The acid value was measured in accordance with "JIS K 0070-1992 Test methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemical products."

(Component Example D2: Ethylene Acrylic Acid Copolymer)
As the ethylene acrylic acid copolymer of Component Example D2, AC (registered trademark) 5120 manufactured by Honeywell was prepared.

(Component example D3: hydrogenated castor oil)
Hydrogenated Castor Oil "B" Grade (abbreviated as "HCO-B Grade" in Table 4) from Royal Castor Products was prepared as hydrogenated castor oil of Component Example D3.

(Synthesis of diamide compounds of Comparative Synthesis Examples 1 to 3)
Furthermore, as diamide compounds not corresponding to the mixture (M) of the present invention, the diamide compounds of Comparative Synthesis Examples 1 to 3 were synthesized. These diamide compounds were obtained by blending two or more monocarboxylic acid components having different carbon numbers, corresponding to the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) of the present invention, together with a diamine component, and simultaneously condensing them. Specifically, the diamine component and the monocarboxylic acid component shown in Table 6 were reacted in a nitrogen gas stream at 190°C for 6 hours while removing the generated water, to obtain the diamide compounds of Comparative Synthesis Examples 1 to 3.

[Production of viscosity modifier]
Next, a method for producing the viscosity modifier will be described.

(Production Examples 1 to 32, Comparative Production Examples 1 to 6)
The diamide compounds (A) of Synthesis Examples A1 to A16, the diamide compounds (B) of Synthesis Examples B1 to B12, the diamide compound (C) of Synthesis Example C1, and the components (D) of Synthesis Example D1 and Component Examples D2 and D3 obtained as described above were melt-mixed to the formulations shown in Table 6. These molten mixtures were then taken out as solids, and the solid mixtures were pulverized in a pulverizer to a median diameter of 1 μm to 10 μm, thereby obtaining the viscosity modifiers of Production Examples 1 to 32 and Comparative Production Examples 5 and 6. The diamide compounds of Comparative Synthesis Examples 1 to 3 obtained as described above were pulverized in a pulverizer to a median diameter of 1 μm to 10 μm, thereby obtaining the viscosity modifiers of Comparative Production Examples 1, 2, and 3. The diamide compound (A) of Synthesis Example A5 was pulverized in a pulverizer to a median diameter of 1 μm to 10 μm, thereby obtaining the viscosity modifier of Comparative Production Example 4.

The ingredients and blend amounts of the viscosity modifiers obtained in Production Examples 1 to 32 and Comparative Production Examples 1 to 6 are shown in Table 7.

[Evaluation of viscosity modifiers]
The viscosity modifiers of Production Examples 1 to 32 and Comparative Production Examples 1 to 6 obtained as described above were used to evaluate the performance of the viscosity modifiers as shown in the following Test Examples 1 to 4.

(Test Example 1 Sealant Formulation 1: Silylated Acrylate Sealant)
Curable compositions (silylated acrylate sealants) of Examples and Comparative Examples were prepared using the sealant formulations shown in Table 8 as follows, and the viscosity-imparting effect of these curable compositions was evaluated.

<Preparation of Curable Composition>
As shown in Table 8, 80.0 parts of TA Polymer SB802S (manufactured by Kaneka Corporation) as the resin component (sealant base polymer), 80.0 parts of Sanso Cizer DINP (manufactured by New Japan Chemical Co., Ltd.) as a plasticizer, 200.0 parts of Ryton S-4 (heavy calcium carbonate: manufactured by Bihoku Funka Kogyo Co., Ltd.) as a filler, 10.0 parts of KRONOS 2190 (titanium dioxide: manufactured by KRONOS), and 11.2 parts of any of the viscosity modifiers of Production Examples 1 to 27 and Comparative Production Example 1 were pre-dispersed using a three-roll mill, and then kneaded at 120 ° C. under reduced pressure using a planetary mixer. To this mixture, 4.0 parts of Silquest A-171 (manufactured by Momentive Corp.) as a dehydrating agent, 4.0 parts of Silquest A-1122 (manufactured by Momentive Corp.) as an adhesion improver, and 3.0 parts of Neostan U-220H (manufactured by Nitto Kasei Co., Ltd.) as a curing catalyst were added, and the mixture was kneaded using a planetary mixer to obtain the curable compositions of Examples 1 to 27 and Comparative Example 1. A blank curable composition containing no viscosity modifier was also prepared. Each curable composition was filled into a sealable container.

<Evaluation method>
The viscosity-imparting effect of the viscosity modifiers added to the curable compositions of Examples 1 to 27 and Comparative Example 1 was evaluated based on three items: viscosity, T.I. value, and viscosity index (thickening). Based on the following criteria, it was determined that the effects of the present invention were not achieved when at least one of the viscosity and viscosity index was rated D. Details of the evaluation method for each item are shown below.

〔viscosity〕
A rheometer AR2000 (manufactured by TA Instruments) was used, and as a jig, a geometry (cone plate) with a diameter of 20 mm and an angle of 1° between the generatrix of the cone and the circular surface was used. The viscosity η ₁ at 25°C when the shear rate (shear rate) was 1.0 ^s was taken as the measured viscosity, and the viscosity-imparting effect was evaluated according to the following criteria.
A: Viscosity _η1 is 2000 or more B+: Viscosity _η1 is 1000 or more and less than 2000 B: Viscosity _η1 is 500 or more and less than 1000 C: Viscosity _η1 is 100 or more and less than 500 D: Viscosity _η1 is less than 100

[T.I. value]
In the same manner as in the viscosity measurement described above, the viscosity _η10 at 25°C was measured when the shear rate (shear rate) was set to 10 s ^-1 , and from these measurement results, the TI value (= _η1 / _η10 ) was calculated, and the viscosity-imparting effect was evaluated according to the following criteria.
A: T.I. is 8 or more B: T.I. is 5 or more but less than 8 C: T.I. is 3 or more but less than 5 D: T.I. is less than 3

[Viscosity index (thickening)]
First, for each of the curable compositions of the Examples and Comparative Examples, a reference sample was prepared in which only the diamide compound synthesized using a monocarboxylic acid containing hydrogenated castor oil fatty acid was used as a viscosity modifier among the diamide compounds contained in the mixture (M). (In other words, a sample having the same composition as the curable compositions of the Examples and Comparative Examples, except that only the diamide compound synthesized using a monocarboxylic acid containing hydrogenated castor oil fatty acid was used as a viscosity modifier.) Specifically, the reference sample of the curable composition of Example 27 was a curable composition containing only the diamide compound (C) of Synthesis Example C1 as a viscosity modifier. Furthermore, the reference sample of the curable composition of Comparative Example 1 was a curable composition containing only the diamide compound (A) of Synthesis Example A1 as a viscosity modifier. The reference samples of the curable compositions of the other Examples and Comparative Examples were curable compositions containing only the diamide compound (A) as a viscosity modifier. Next, the viscosity η _s1 of each reference sample at 25°C was measured at a shear rate of 1.0 s ^-1 . The viscosity index I was defined as the relative value of the viscosity _η1 of each curable composition when the measured value of the viscosity _ηs1 of each reference sample was defined as 100. That is, the viscosity index I is calculated by the following formula (1), and indicates the thickening effect of the viscosity modifier used in the curable compositions of the Examples and Comparative Examples compared to the viscosity modifier used in the reference sample. Note that a viscosity index I of 100 means that the viscosity _η1 of the curable composition is the same (no change) as the viscosity of the reference sample corresponding to that curable composition.
I=(η ₁ /η _s1 )×100 (1)

The viscosity-imparting effect was evaluated according to the value of the viscosity index I according to the following criteria.
A: Viscosity index I is 150 or more B: Viscosity index I is 120 or more and less than 150 C: Viscosity index I is 100 or more and less than 120 D: Viscosity index I is less than 100

<Evaluation results>
The results of the evaluation as described above, as well as the viscosity modifiers used in each curable composition and their blend ratios, are shown in Table 9.

As shown in Table 9, all of the curable compositions of Examples 1 to 27 exhibited good viscosity-imparting effects (at least the viscosity and viscosity index were rated C or higher). Furthermore, as can be seen from a comparison of Examples 1 to 12, when the carbon numbers of the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) were 2 to 18, good viscosity-imparting effects were exhibited; when the carbon number was 14 or less, better viscosity-imparting effects were exhibited; and when the carbon number was 12 or less, even better viscosity-imparting effects were exhibited. Furthermore, as shown in Examples 2, 5, 13 to 16, etc., when the difference in the carbon numbers between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) was at least 8 or less, good viscosity-imparting effects were exhibited. Furthermore, as can be seen from a comparison of Examples 5, 17, and 20, when the monocarboxylic acid component (A-c) contained hydrogenated castor oil fatty acid, the monocarboxylic acid component (B-c) did not contain hydrogenated castor oil fatty acid, and the diamide compound (C) was not contained, an excellent viscosity-imparting effect was observed when the mixing ratio (A/B) of the diamide compound (A) to the diamide compound (B) was 95/5 to 60/40. Next, as shown in Examples 25 and 26, an excellent viscosity-imparting effect was maintained even when another component (D) was mixed in addition to the diamide compound (A) and the diamide compound (B). Furthermore, Example 27, in which the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) did not contain hydrogenated castor oil fatty acid, and the monocarboxylic acid component (C-c) contained hydrogenated castor oil fatty acid, also exhibited an excellent viscosity-imparting effect.

On the other hand, Comparative Example 1, which used a diamide compound that does not fall under the category of mixture (M) of the present invention as a viscosity modifier, had a low viscosity index and did not achieve the viscosity-imparting effect required by the present invention.

(Test Example 2, Sealant Formulation 2: Modified Silicone Sealant)
The curable compositions (modified silicone sealants) of Examples and Blank were prepared using the sealant formulations shown in Table 10 as follows, and the viscosity-imparting effect of these curable compositions was evaluated.

<Preparation of Curable Composition (Preparation Example 2-1)>
As shown in Table 10, 100.0 parts of MS Polymer S303H (manufactured by Kaneka Corporation) was used as the resin component (sealant base polymer), 60.0 parts of Sanso Cizer DINP (manufactured by New Japan Chemical Co., Ltd.) was used as the plasticizer, 200.0 parts of Ryton S-4 (heavy calcium carbonate: manufactured by Bihoku Funka Kogyo Co., Ltd.) was used as the filler, 10.0 parts of KRONOS 2190 (titanium dioxide: manufactured by KRONOS Co., Ltd.) was used as the viscosity adjuster, and 14.0 parts of any of the viscosity adjusters of Production Examples 3, 5, 7, and 28 was used as the viscosity adjuster. The mixture was pre-dispersed using a three-roll mill and then kneaded at 55 ° C. under reduced pressure using a planetary mixer. To this mixture, 4.0 parts of Silquest A-171 (manufactured by Momentive Chemicals) as a dehydrating agent, 4.0 parts of Silquest A-1122 (manufactured by Momentive Chemicals) as an adhesion improver, and 3.0 parts of Neostan U-220H (manufactured by Nitto Kasei Co., Ltd.) as a curing catalyst were added, and the mixture was kneaded with a planetary mixer to obtain the curable compositions of Examples 28 to 31. A blank curable composition to which no viscosity modifier was added was also prepared. Each curable composition was filled into a sealable container.

<Preparation of Curable Composition (Preparation Example 2-2)>
The curable compositions of Examples 32 to 34 were obtained in the same manner as in Preparation Example 2-1, except that the kneading temperature under reduced pressure was 25°C and the viscosity modifier used was any one of the viscosity modifiers of Preparation Examples 1, 3, and 4. The temperature was maintained at 25°C during kneading (if the kneading temperature rose due to heat of dispersion, it was cooled to 25°C). In addition, as in Preparation Example 2-1, a curable composition containing no viscosity modifier was also prepared as a blank, and each curable composition was filled into a sealable container.

The viscosity-imparting effect of the viscosity modifiers added to the curable compositions of Examples 28 to 34 was evaluated based on three items: viscosity, T.I. value, and viscosity index (thickening). Details of the evaluation methods for each item are provided below.

〔viscosity〕
Using the same method as in Test Example 1, the viscosity η ₁ at 25°C when the shear rate (shear rate) was set to 1.0 ^s- 1 was used as the viscosity measurement value, and the viscosity-imparting effect was evaluated according to the following criteria. Here, the viscosity of a curable composition such as a sealant not only varies depending on its application and desired function, but also varies depending on the viscosity range desired by the user, even for the same application or function. Furthermore, the viscosity of the curable composition varies depending on its formulation and preparation conditions, depending on the viscosity of the base composition (the viscosity of a blank composition not containing a viscosity modifier). Therefore, there is no particular problem as long as the effect of adding a viscosity modifier can be relatively evaluated by setting the viscosity evaluation criteria based on the base viscosity. Therefore, there is no particular problem even if the evaluation criteria of Test Example 1 and Test Example 2 are different.
A: Viscosity _η1 is 1000 or more B: Viscosity _η1 is 500 or more and less than 1000 C: Viscosity _η1 is 100 or more and less than 500 D: Viscosity _η1 is less than 100

[T.I. value]
The T.I. value was calculated in the same manner as in Test Example 1, and the viscosity-imparting effect was evaluated according to the following criteria.
A: T.I. is 8 or more B: T.I. is 5 or more but less than 8 C: T.I. is 3 or more but less than 5 D: T.I. is less than 3

[Viscosity index (thickening)]
The viscosity index I was determined in the same manner as in Test Example 1, and the viscosity-imparting effect was evaluated according to the following criteria.
A: Viscosity index I is 150 or more B: Viscosity index I is 120 or more and less than 150 C: Viscosity index I is 100 or more and less than 120 D: Viscosity index I is less than 100

<Evaluation results>
The results of the evaluation of the curable composition of Preparation Example 2-1 (kneaded at 55°C) as described above, as well as the viscosity modifiers used in each curable composition and their blend ratios, are shown in Table 11. Furthermore, the results of the evaluation of the curable composition of Preparation Example 2-2 (kneaded at 25°C) as described above, as well as the viscosity modifiers used in each curable composition and their blend ratios, are shown in Table 12.

As shown in Tables 11 and 12, the curable compositions of Examples 28 to 34 all exhibited good viscosity-imparting effects (at least the viscosity and viscosity index were rated C or higher). The viscosity modifier of Production Example 28 was an example in which hydrogenated castor oil (Component Example D3) was further mixed in addition to the same diamide compound (A) and diamide compound (B) as in Production Example 5. Example 31, which used the viscosity modifier of Production Example 28, had a viscosity-imparting effect equal to or greater than that of Example 29, which used Production Example 5. Furthermore, the curable compositions of Examples 32 to 34, in which the viscosity modifiers of Production Examples 1, 3, and 4 were kneaded at 25°C, also exhibited excellent viscosity-imparting effects.

(Test Example 3, Sealant Formulation 3: Modified Silicone Sealant)
Curable compositions (modified silicone sealants) of Examples and Blank were prepared using the sealant formulations shown in Table 13 as follows, and the viscosity-imparting effect of these curable compositions was evaluated.

<Preparation of Curable Composition>
As shown in Table 13, the resin component (sealant base polymer) was MS Polymer S303H (manufactured by Kaneka Corporation) 100.0 parts, the plasticizer was Sanso Cizer DINP (manufactured by New Japan Chemical Co., Ltd.) 60.0 parts, the filler was Ryton S-4 (heavy calcium carbonate: manufactured by Bihoku Funka Kogyo Co., Ltd.) 200.0 parts, Shiraenka CC-R (synthetic calcium carbonate: Shiraishi Kogyo Co., Ltd.) 60.0 parts, KRONOS 2190 (titanium dioxide: manufactured by KRONOS) 10.0 parts, and the viscosity modifier was 14.0 parts of any of the viscosity modifiers of Production Examples 3, 4, 6, 8, 29-32 and Comparative Production Examples 5 and 6. The mixture was pre-dispersed in a three-roll mill and then kneaded at 25 ° C. under reduced pressure using a planetary mixer. During kneading, the temperature was maintained at 25 ° C. (If the kneading temperature rose due to the heat of dispersion, it was cooled to 25 ° C.). To this mixture, 4.0 parts of Silquest A-171 (manufactured by Momentive Corp.) as a dehydrating agent, 4.0 parts of Silquest A-1122 (manufactured by Momentive Corp.) as an adhesion improver, and 3.0 parts of Neostan U-220H (manufactured by Nitto Kasei Co., Ltd.) as a curing catalyst were added, and the mixture was kneaded using a planetary mixer to obtain the curable compositions of Examples 35 to 42 and Comparative Examples 2 and 3. A blank curable composition containing no viscosity modifier was also prepared. Each curable composition was filled into a sealable container.

The viscosity-imparting effect of the viscosity modifiers added to the curable compositions of Examples 35-42 and Comparative Examples 2 and 3 was evaluated based on three items: viscosity, T.I. value, and viscosity index (thickening). Details of the evaluation methods for each item are provided below.

〔viscosity〕
The viscosity η ₁ at 25°C when the shear rate (shear rate) was set to 1.0 s ^-1 using the same method as in Test Example 1 was taken as the measured viscosity, and the viscosity-imparting effect was evaluated according to the following criteria. As described above, the viscosity of the curable composition varies depending on the formulation and preparation conditions of the base composition, so there is no particular problem as long as the viscosity evaluation criteria are set based on the base viscosity and the effect of adding a viscosity modifier can be evaluated relatively. Therefore, there is no particular problem even if the evaluation criteria for Test Example 1 and Test Example 2 are different from those for Test Example 3.
A: Viscosity _η1 is 2000 or more B: Viscosity _η1 is 1000 or more and less than 2000 C: Viscosity _η1 is 500 or more and less than 1000 D: Viscosity _η1 is less than 500

[T.I. value]
The T.I. value was calculated in the same manner as in Test Example 1, and the viscosity-imparting effect was evaluated according to the following criteria.
A: T.I. is 8 or more B: T.I. is 5 or more but less than 8 C: T.I. is 3 or more but less than 5 D: T.I. is less than 3

[Viscosity index (thickening)]
The viscosity index I was determined in the same manner as in Test Example 1, and the viscosity-imparting effect was evaluated according to the following criteria.
A: Viscosity index I is 150 or more B: Viscosity index I is 120 or more and less than 150 C: Viscosity index I is 100 or more and less than 120 D: Viscosity index I is less than 100

<Evaluation results>
The results of the evaluation as described above, as well as the viscosity modifiers used in each curable composition and their blend ratios, are shown in Table 14.

As shown in Table 14, the curable compositions of Examples 35 to 42 all exhibited a good viscosity-imparting effect (viscosity, T.I. value, and viscosity index were rated B or higher). This demonstrates that, depending on the formulation of the curable composition and the composition of the viscosity modifier, fatty acid diamides can be activated even at room temperature of 25°C, thereby providing excellent thickening properties. On the other hand, the curable compositions of Comparative Examples 2 and 3 all exhibited poor viscosity-imparting effects (at least one of viscosity, T.I. value, and viscosity index was rated D).

(Test Example 4: Non-aqueous paint formulation: Ultra high solids epoxy paint)
Non-aqueous coating compositions (ultra-high solids epoxy coatings) of Examples and Comparative Examples were prepared using the non-aqueous coating formulations shown in Table 15 as follows, and these non-aqueous coating compositions were evaluated for their viscosity-imparting effect and their effect of improving overcoatability inhibition.

<Preparation of non-aqueous coating composition (Preparation Example 4-1)>
As shown in Table 15, 39.1 parts of jER (registered trademark) 806 (an epoxy resin manufactured by Mitsubishi Chemical Corporation) was used as the resin, and LS-632 (Hubei Greenhome Materials) was used as the reactive diluent. A mixture of 11.3 parts of a bifunctional reactive diluent manufactured by JNC Technology Co., Ltd., 2.3 parts of Sila-Ace (registered trademark) S510 (a silane coupling agent manufactured by JNC Corporation), 2.0 parts of dimethyl carbonate as an organic solvent, 8.8 parts of Talc No. 1 (a body pigment manufactured by Takehara Chemical Industry Co., Ltd.), 15.0 parts of PG-K10 (a body pigment manufactured by Sibelco Japan), 22.1 parts of barium sulfate BA (a body pigment manufactured by Sakai Chemical Industry Co., Ltd.), and 1.3 parts of Typeque (registered trademark) R-820 (a rutile-type titanium oxide manufactured by Ishihara Sangyo Kaisha, Ltd.), and 1.0 part of the viscosity modifier of any of Production Examples 6, 22, and Comparative Production Examples 2 to 4 was charged, and the mixture was dispersed using a dissolver (blade diameter 5 cm) until the temperature of the paint reached 60 ° C. to obtain an epoxy base resin (Part A). To this base resin, 21.5 parts of Ancamine 2644 (an amine-based curing agent manufactured by Evonik Japan Co., Ltd.) was added as PART B, and the mixture was mixed to obtain the non-aqueous coating compositions of Examples 43 and 44 and Comparative Examples 4 to 6. A non-aqueous coating composition to which no viscosity modifier was added was also prepared as a blank.

<Preparation of non-aqueous coating composition (Preparation Example 4-2)>
The non-aqueous coating compositions of Example 45 and Comparative Example 7 were obtained in the same manner as in Preparation Example 4-1, except that the temperature during dispersion of the coating was 25°C and the viscosity modifier used was either the viscosity modifier of Preparation Example 29 or Comparative Preparation Example 2. The temperature was maintained at 25°C during dispersion (if the dispersion temperature rose due to the heat of dispersion, it was cooled to 25°C). In addition, a non-aqueous coating composition to which no viscosity modifier was added was also prepared as a blank, in the same manner as in Preparation Example 4-1.

The viscosity modifiers added to the non-aqueous coating compositions of Examples 43-45 and Comparative Examples 4-7 were evaluated for their viscosity-imparting effect and their effect on improving recoatability. The viscosity-imparting effect was evaluated based on viscosity, and the effect on improving recoatability was evaluated based on two items: anti-sagging properties and coating contact angle. Details of the evaluation methods for each item are provided below.

〔viscosity〕
The day after the non-aqueous coating compositions were prepared as described above, their viscosity (P) was measured at 25°C and 60 rpm using a Brookfield viscometer. The higher the viscosity of the non-aqueous coating composition, the greater the viscosity-imparting effect of the viscosity modifier. In this example, a viscosity of 25 P or higher, as evaluated by the above method, was deemed to be sufficient to provide the viscosity-imparting effect required in the present invention (acceptable criterion).

[Anti-sagging properties]
As an index of sagging resistance, the sagging limit film thickness (μm) of the non-aqueous coating composition prepared as described above was measured. Specifically, using a sag tester (trade name "Sag Tester BOX 100-500, 500-700, 600-1000" manufactured by Taiyu Kizai Co., Ltd.), the non-aqueous coating composition of any of Examples 32, 33 and Comparative Examples 2 to 4 was applied to a sagging test paper (trade name "All Black Measurement Paper" manufactured by Taiyu Kizai Co., Ltd.) at five different film thicknesses (100 μm to 500 μm, 500 μm to 700 μm, 600 μm to 1000 μm) with thicknesses differing by 100 μm. As a result, coating film strips having five different film thicknesses were arranged at predetermined intervals on the sagging test paper. Next, this test paper was stood upright with the thinner coating film band at the top, and air-dried at room temperature, after which the coating film first began to drip over the gap between the coating film bands, and the thickness of the coating film band with a thickness one step thinner than the coating film band where a portion of the coating film that had come into contact with the lower coating film band was observed was taken as the sagging limit thickness (μm). In this example, when the sagging limit thickness evaluated by the above method was 600 μm or more, it was judged that the coating film had sufficient sagging prevention properties (pass criterion) to achieve the effect of improving the overcoatability inhibition required in the present invention.

[Coating film contact angle]
The non-aqueous coating composition prepared as described above was applied to the surface of a tinplate substrate using a film applicator with a groove depth of 500 μm, and the non-aqueous coating composition was dried and cured at 25 ° C to obtain a coating film formed on the surface of the tinplate substrate. Next, at 25 ° C, a 2 μL droplet of n-hexadecane was dropped onto the cured coating film, and the degree of spreading of the droplet (coating contact angle) was evaluated. The coating contact angle (°) was measured using a DM-501 (Kyowa Interface Science Co., Ltd.) and the static contact angle was measured according to the θ/2 method of the sessile drop method. In this example, when the coating contact angle evaluated by the above method was 15 ° or less, it was determined that the coating contact angle was sufficiently small to exhibit the effect of improving overcoatability inhibition required in the present invention (acceptance criterion).

<Evaluation results>
The results of the evaluation of the non-aqueous coating composition of Preparation Example 4-1 (dispersed at 60°C) as described above, as well as the viscosity modifiers used in each non-aqueous coating composition and their blend ratios, are shown in Table 16. Furthermore, the results of the evaluation of the non-aqueous coating composition of Preparation Example 4-2 (dispersed at 25°C) as described above, as well as the viscosity modifiers used in each non-aqueous coating composition and their blend ratios are shown in Table 17.

As shown in Tables 16 and 17, the non-aqueous coating compositions of Examples 43 to 45 all exhibited favorable viscosity-imparting effects and improved recoatability (the evaluations of viscosity, sagging limit film thickness, and coating contact angle all fell within the acceptable range). On the other hand, Comparative Examples 4 and 5, which used a diamide compound not corresponding to the mixture (M) of the present invention as a viscosity modifier, and Comparative Example 6, which used only diamide compound (A) as a viscosity modifier without diamide compound (B), exhibited poor evaluations of viscosity, sagging limit film thickness, and coating contact angle, failing to achieve the effects of the present invention. Furthermore, Comparative Example 7, which used a viscosity modifier that did not contain diamide compound (B) and was dispersed at 25°C, exhibited low viscosity and sagging prevention properties, failing to meet the acceptable range. Furthermore, no increase in the coating contact angle was observed in Comparative Example 7. This is presumably because, given the low viscosity value, the viscosity modifier was not activated at the low dispersion temperature of 25°C, resulting in little viscosity-imparting effect.

Claims (14)

The composition includes a mixture (M) obtained by melt-mixing two or more compounds including a diamide compound (A), a diamide compound (B), and an optional diamide compound (C),
The diamide compound (A) is a diamide obtained by condensing a diamine component (A-a) with a monocarboxylic acid component (Ac),
The diamide compound (B) is a diamide obtained by condensing a diamine component (Ba) with a monocarboxylic acid component (Bc),
The diamide compound (C) is a diamide obtained by condensing a diamine component (Ca) with a monocarboxylic acid component (Cc),
the monocarboxylic acid component (Ac) and the monocarboxylic acid component (Bc) are monocarboxylic acids having different numbers of carbon atoms,
At least one of the monocarboxylic acid component (Ac), the monocarboxylic acid component (Bc), and the monocarboxylic acid component (Cc) contains a hydrogenated castor oil fatty acid. The viscosity modifier according to claim 1, characterized in that the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) are both monocarboxylic acids having 2 to 18 carbon atoms. The viscosity modifier described in claim 1, characterized in that the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) is 16 or less. The viscosity adjuster according to claim 1, characterized in that the monocarboxylic acid component (A-c) contains at least a linear saturated fatty acid (a), and the monocarboxylic acid component (B-c) contains at least a linear saturated fatty acid (b). The viscosity modifier according to claim 1, characterized in that, when the monocarboxylic acid component (A-c) contains hydrogenated castor oil fatty acid, the monocarboxylic acid component (B-c) does not contain hydrogenated castor oil fatty acid and does not contain the diamide compound (C), the mixing ratio (A/B) of the diamide compound (A) to the diamide compound (B) is 95/5 to 55/45. The viscosity modifier described in claim 1, characterized in that the diamine component (A-a) and the diamine component (B-a) are the same type of diamine. a mixing step of melt-mixing two or more compounds including the diamide compound (A), the diamide compound (B), and the optional diamide compound (C);
an atomization step of atomizing the mixture (M) obtained in the mixing step to obtain a viscosity modifier;
and
The diamide compound (A) is a diamide obtained by condensing a diamine component (A-a) with a monocarboxylic acid component (Ac),
The diamide compound (B) is a diamide obtained by condensing a diamine component (Ba) with a monocarboxylic acid component (Bc),
The diamide compound (C) is a diamide obtained by condensing a diamine component (Ca) with a monocarboxylic acid component (Cc),
the monocarboxylic acid component (Ac) and the monocarboxylic acid component (Bc) are monocarboxylic acids having different numbers of carbon atoms,
At least one of the monocarboxylic acid component (Ac), the monocarboxylic acid component (Bc), and the monocarboxylic acid component (Cc) contains a hydrogenated castor oil fatty acid. The method for producing a viscosity modifier described in claim 7, wherein the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) are both monocarboxylic acids having 2 to 18 carbon atoms. The method for producing a viscosity modifier described in claim 7, characterized in that the difference in carbon number between the monocarboxylic acid component (A-c) and the monocarboxylic acid component (B-c) is 16 or less. The method for producing a viscosity modifier described in claim 7, characterized in that the monocarboxylic acid component (A-c) contains at least a linear saturated fatty acid (a), and the monocarboxylic acid component (B-c) contains at least a linear saturated fatty acid (b). The method for producing a viscosity modifier according to claim 7, wherein the monocarboxylic acid component (A-c) contains hydrogenated castor oil fatty acid, the monocarboxylic acid component (B-c) does not contain hydrogenated castor oil fatty acid, and does not contain the diamide compound (C), and the mixing ratio (A/B) of the diamide compound (A) to the diamide compound (B) is 95/5 to 55/45. The method for producing a viscosity modifier described in claim 7, wherein the diamine component (A-a) and the diamine component (B-a) are the same type of diamine. A curable composition comprising the viscosity modifier according to any one of claims 1 to 6 and a resin component. A non-aqueous coating composition comprising the viscosity modifier according to any one of claims 1 to 6, a resin component, and an optional volatile solvent,
A non-aqueous coating composition, characterized in that the content of the volatile solvent is 15 mass % or less based on the total amount of the non-aqueous coating composition.