TWI875853B - Hardening composition - Google Patents

Abstract

[Topic] To provide a curable composition having both excellent photocurability and excellent thermocurability. [Solution] A curable composition comprises: (1) a compound having a (meth)acryl group; (2) an epoxy compound having two or more epoxy groups in one molecule and being solid at 25°C; (3) a polythiol compound having two or more alkyl groups in one molecule; (4) a photoradical generator; and (5) a latent curing agent; wherein the amount of component (3) is not less than 15% by weight and not more than 50% by weight relative to the total weight of the curable composition.

Description

Hardening composition

The present invention relates to a hardening composition.

In recent years, along with the thinning of portable devices such as smartphones, the camera modules installed in portable devices such as smartphones have also gradually become smaller. In addition, it is expected that camera modules will also be installed in wearable devices, and the requirements for miniaturization and thinning are getting higher and higher. Moreover, with the miniaturization of camera modules, the parts that are connected and fixed between the components of the camera modules are becoming more and more fine, so the impact resistance of the camera module against falling has become very important. Therefore, even if the camera module is impacted by falling, the bonding area between the components must be maintained even if it is very small. Once the bonding area becomes smaller, the bonding part of the components will easily peel off, so the improvement of the bonding strength per unit area of the adhesive is more and more important.

On the one hand, adhesives used in the assembly of camera modules, etc., need to be hardened at low temperatures in order to avoid heat damage to image sensors, etc. caused by high-temperature treatment. On the other hand, from the perspective of improving production efficiency, they are also required to be hardened at low temperatures and in a short time (low-temperature-short-time hardening). From this perspective, UV-hardening adhesives or thermosetting epoxy resin adhesives are often used as low-temperature-short-time hardening adhesives (for example, Patent Documents 1 and 2). However, UV-hardening adhesives, although they can be hardened quickly, have disadvantages such as hardening deformation due to hardening shrinkage, low bonding strength, and cannot be used for bonding parts that are not exposed to light. On the other hand, although thermosetting epoxy resin adhesives can be said to be low-temperature and short-time curing adhesives, in order to maintain the bonding posture during bonding, the components (parts) to be bonded must be fixed with a fixture or device. In addition, due to the increase in heating temperature, the viscosity decreases, and before curing, it may sag or flow outside the desired part, which may not necessarily be satisfactory.

Therefore, in order to solve the above-mentioned problems, in order to arrange the components constituting the camera module with high precision, several adhesives of this type have been proposed (for example, patent documents 3 and 4), which are temporarily fixed by curing (preliminary curing) caused by light (ultraviolet rays, visible light) irradiation, and then connected (formal fixing) by curing (formal curing) caused by heat.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2004-140497

[Patent Document 2] Japanese Patent Publication No. 2013-88525

[Patent Document 3] Japanese Patent Publication No. 2009-51954

[Patent Document 4] Japanese Patent Publication No. 2009-79216

As described in patent documents 3 and 4, even if light and heat curing adhesives are used, if the bonding strength is low, the temporary fixation is low, and there will be problems with parts loosening during the process. In addition, in the structure of the camera module, there are places where light cannot reach the inside of the module. In such places, light curing cannot be fully performed, and in fact, only heat curing becomes possible, resulting in the problem of not being able to ensure sufficient bonding strength.

The present invention is developed with the above-mentioned issues in mind, and its purpose is to provide a curable composition that has both excellent light curing properties and excellent heat curing properties, as well as excellent strength.

The present invention capable of achieving the above-mentioned purpose is as described below.

[1] A curable composition comprising the following components (1) to (5): (1) a compound having a (meth)acryl group; (2) an epoxy compound having two or more epoxy groups in one molecule and being solid at 25°C; (3) a polythiol compound having two or more alkyl groups in one molecule; (4) a photoradical generator; and (5) a latent curing agent; wherein the amount of component (3) is not less than 15% by weight and not more than 50% by weight relative to the total weight of the curable composition.

[2] The curable composition as described in [1] above, wherein the component (2) contains at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin.

[3] The curable composition as described in [1] or [2] above, wherein the component (3) contains: a polythiol compound having 2 to 6 alkyl groups in one molecule.

[4] A curable composition as described in any one of the above [1] to [3], wherein the molar ratio of the sum of the acryl groups, methacryl groups and epoxy groups in component (1) to the phenyl groups in component (3) (sum of the acryl groups, methacryl groups and epoxy groups in component (2)/phenyl groups in component (3)) is 0.5 to 2.0.

[5] A curable composition as described in any one of [1] to [4] above, wherein component (5) contains an amine-epoxy adduct compound and/or an amine-isocyanate adduct compound.

[6] An adhesive comprising a hardening composition as described in any one of the above [1] to [5].

[7] The adhesive described in [6] above, wherein the adhesive is used for bonding components of a camera module.

[8] A sealant comprising a hardening composition as described in any one of the above [1] to [5].

[9] A coating agent comprising a hardening composition as described in any one of the above [1] to [5].

[10] A method for manufacturing a camera module comprises the following steps (I) to (III): (I) a step of positioning a first connecting part and a second connecting part coated with a curable composition as described in any one of the above-mentioned [1] to [5]; (II) a step of temporarily fixing the first connecting part and the second connecting part by curing the curable composition by irradiating light; and (III) a step of formally fixing the first connecting part and the second connecting part by curing the curable composition by heating.

According to the present invention, a curable composition having both excellent light curing properties and excellent heat curing properties can be obtained.

<Hardening composition>

The curable composition of the present invention is characterized by containing the following components (1) to (5): (1) a compound having a (meth)acryloyl group; (2) an epoxy compound having two or more epoxy groups in one molecule and being solid at 25°C (hereinafter sometimes referred to as a "solid epoxy compound"); (3) a polythiol compound having two or more hydroxyl groups (-SH) in one molecule (hereinafter sometimes referred to as a "polythiol compound"); (4) a photoradical generator; and (5) a latent curing agent; wherein the amount of component (3) is 15% by weight or more and 50% by weight or less relative to the total weight of the curable composition.

Components (1) to (5) may be used alone or in combination of two or more. When the curable composition of the present invention contains components other than components (1) to (5), the components may be used alone or in combination of two or more. The components are described below in order.

<(1) Compounds having a (meth)acryloyl group>

The compound having a (meth)acryl group used as component (1) in the present invention is a component that mainly plays a role in improving bonding strength. In addition, the "(meth)acryl group" in the present invention means one or both of an acryl group and a methacryl group.

The number of (meth)acryloyl groups in one molecule of a compound having a (meth)acryloyl group may be 1 or more. When the compound having a (meth)acryloyl group is a mixture, the number indicates the average value per molecule. When both an acryloyl group and a methacryloyl group exist in one molecule, the number means the total number of acryloyl groups and methacryloyl groups in one molecule. The number of (meth)acryloyl groups in one molecule of a compound having a (meth)acryloyl group (excluding the phosphoric acid-modified (meth)acrylate described later) is preferably 1 to 6, more preferably 2 to 6, and even more preferably 2 to 4.

The molecular weight of the compound having a (meth)acryloyl group (excluding the phosphoric acid-modified (meth)acrylate described later) is preferably 50 to 5,000, more preferably 70 to 4,000, and even more preferably 100 to 2,000. If the molecular weight is less than 50, the volatility is high, which is not good from the perspective of odor and operability; if the molecular weight exceeds 5,000, the viscosity of the composition will increase, and the coating property of the composition will tend to decrease. In addition, a molecular weight of more than 1,000 means a weight average molecular weight, which can be measured by gel permeation chromatography (GPC). A molecular weight of less than 1,000 can be measured by a gravimetric analyzer (e.g., ESI-MS).

Examples of compounds having a (meth)acryloyl group include the following compounds. In addition, the following compounds may be used alone or in combination of two or more.

(Compounds containing one acryl or methacryl group in one molecule)

β-Carboxyethyl (meth)acrylate

Isobornyl (meth)acrylate

Octyl/decyl (meth)acrylate

Ethoxylated phenyl (meth)acrylate

EO modified phenol (meth) acrylate

EO modified o-phenylphenol (meth)acrylate

EO modified p-cresol (meth)acrylate

EO modified nonylphenol (meth)acrylate

PO modified nonylphenol (meth)acrylate

N-(Methyl)acryloyloxyethyl hexahydrophthalimide

ω-Carboxyl-polycaprolactone mono(meth)acrylate

Monohydroxyethyl (meth) phthalate

2-Hydroxy-3-phenoxypropyl (meth)acrylate

In addition, the so-called "(meth)acrylate" in the present invention means one or both of acrylate and methacrylate. Also, the so-called "EO modification" means modification by adding ethylene oxide (EO). Also, the so-called "PO modification" means modification by adding propylene oxide (PO).

(Compounds containing two (meth)acryloyl groups in one molecule)

Dipropylene glycol di(meth)acrylate

1,6-Hexanediol di(meth)acrylate

Tripropylene glycol di(meth)acrylate

PO modified neopentyl glycol di(meth)acrylate

Tricyclodecanedimethanol di(meth)acrylate

EO modified bisphenol F di(meth)acrylate

EO modified bisphenol A di(meth)acrylate

EO modified isocyanuric acid di(meth)acrylate

Polypropylene glycol di(meth)acrylate

Polyethylene glycol di(meth)acrylate

Neopentyl glycol Hydroxyl neopentanoate Di(meth)acrylate

Polyurethane with 2 (meth)acryloyl groups in one molecule

Polyester with 2 (meth)acryloyl groups in one molecule

(Compounds containing three or more (meth)acryloyl groups in one molecule)

Trihydroxymethylpropane tri(meth)acrylate

PO modified trihydroxymethylpropane tri(meth)acrylate

EO modified trihydroxymethylpropane tri(meth)acrylate

EO modified isocyanuric acid (tri) (meth) acrylate

Pentaerythritol (tri/tetra) (meth)acrylate

Glyceryl propoxy tri(meth)acrylate

Pentaerythritol ethoxylated tetra(meth)acrylate

Bis(trihydroxymethyl)propane tetra(meth)acrylate

Dipentaerythritol (penta/hexa) (meth)acrylate

Dipentaerythritol hexa(meth)acrylate

EO denatured diglycerol tetra(meth)acrylate

Polyurethane with 3 (meth)acryloyl groups in one molecule

Polyester with 3 (meth)acryloyl groups in one molecule

Furthermore, the so-called pentaerythritol (tri/tetra) (meth)acrylate is a mixture of pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate. The mixing ratio (pentaerythritol tri(meth)acrylate/pentaerythritol tetra(meth)acrylate) is a weight ratio, and 5/95~95/5 is preferred, and 30/70~70/30 is more preferred.

Furthermore, the so-called dipentaerythritol (penta/hexa) (meth) acrylate is a mixture of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate. The mixing ratio (dipentaerythritol penta (meth) acrylate/dipentaerythritol hexa (meth) acrylate) is a weight ratio, and 5/95~95/5 is preferred, and 30/70~70/30 is more preferred.

In addition, as a compound having a (meth)acryl group, EO modified isocyanuric acid (di/tri) (meth)acrylate can be used. Here, the so-called EO modified isocyanuric acid (di/tri) (meth)acrylate is a mixture of EO modified isocyanuric acid di(meth)acrylate and EO modified isocyanuric acid tri(meth)acrylate. The mixing ratio (EO modified isocyanuric acid di(meth)acrylate/EO modified isocyanuric acid tri(meth)acrylate) is a weight ratio, and 1/99~99/1 is preferred, 10/90~90/10 is more preferred, and 40/60~60/40 is more preferred.

From the viewpoint of storage stability and adhesion, it is preferred that component (1) contains phosphoric acid-modified (meth)acrylate. Here, "phosphoric acid-modified" means modified by ester bonding with phosphoric acid. Phosphoric acid-modified (meth)acrylate may be used alone or in combination of two or more. Phosphoric acid-modified (meth)acrylate is preferably phosphoric acid-modified methacrylate.

Phosphoric acid-modified (meth)acrylate can be produced by, for example, the following method (i), but the present invention is not limited thereto.

(i) A method of reacting a compound having a (meth)acryloyl group and a hydroxyl group with phosphoric acid.

The compound having a (meth)acryloyl group and a hydroxyl group in one molecule that can be used in the above method (i) can be prepared by, for example, the following method (ii) or (iii), but the present invention is not limited thereto.

(ii) A method of reacting (meth)acrylic acid or (meth)acrylic acid ester with a polyol (such as alkylene glycol, glycerol, etc.) in such a ratio that the hydroxyl group of the polyol remains.

(iii) A method of adding an alkylene oxide (e.g., ethylene oxide, propylene oxide, etc.) to (meth)acrylic acid.

Phosphoric acid-modified (meth)acrylates are commercially available products. Examples of such commercial products include "EBECRYL168" manufactured by ALLNEX Co., Ltd., "KAYAMER PM-2" and "KAYAMER PM-21" manufactured by Nippon Kayaku Co., Ltd., "LIGHT ESTER P-1M", "LIGHT ESTER P-2M", and "LIGHT ESTER ACRYLATE P-1A(N)" manufactured by Kyoeisha Chemical Co., Ltd., and "JPA-514" manufactured by Johoku Chemical Industry Co., Ltd.

The number of (meth)acryloyl groups in one molecule of phosphoric acid-modified (meth)acrylate is preferably 0.5 to 3, more preferably 1 to 2, and even more preferably 1 to 1.5. In addition, when the phosphoric acid-modified (meth)acrylate is a mixture, the number represents the average value per molecule.

The molecular weight of phosphoric acid-modified (meth)acrylate is preferably 100~1,000, more preferably 150~800, and even more preferably 200~600.

When phosphoric acid-modified (meth)acrylate is used, from the perspective of storage stability and curability, its amount is preferably 0.001 to 5 weight parts, more preferably 0.01 to 3 weight parts, and even more preferably 0.05 to 2 weight parts relative to 100 weight parts of component (1).

In one embodiment of the present invention, component (1) contains: preferably at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, dipentaerythritol hexa(meth)acrylate and phosphoric acid-modified (meth)acrylate; more preferably at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, dipentaerythritol hexa(meth)acrylate and phosphoric acid-modified (meth)acrylate.

In another aspect of the present invention, component (1) contains: preferably a mixture of at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate and dipentaerythritol hexa(meth)acrylate and phosphoric acid-modified (meth)acrylate; more preferably a mixture of at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate and dipentaerythritol hexa(meth)acrylate and phosphoric acid-modified (meth)acrylate.

In another aspect of the present invention, component (1) is preferably a mixture of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate or dipentaerythritol hexa(meth)acrylate, and phosphoric acid-modified (meth)acrylate; a mixture of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate or dipentaerythritol hexa(meth)acrylate, and phosphoric acid-modified (meth)acrylate is more preferred.

From the perspective of curability and adhesion, the amount of component (1) is preferably 5% by weight or more, preferably 10% by weight or more, and more preferably 15% by weight or more, and preferably 60% by weight or less, preferably 55% by weight or less, and more preferably 50% by weight or less, relative to the total curable composition.

<(2) Solid Epoxides>

The component (2) used in the present invention is not particularly limited as long as it is a compound having two or more epoxy groups in one molecule and being solid at 25°C.

Examples of solid epoxy compounds include epoxy resins that have two or more epoxy groups in one molecule and are solid at 25°C. In addition, any monomeric epoxy resin (i.e., monomeric epoxy resin) can be used as component (2) of the present invention as long as it has two or more epoxy groups in one molecule and is solid at 25°C.

Examples of the epoxy resin include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, dicyclopentadiene type epoxy resin, biphenyl type epoxy resin, biphenylarane type epoxy resin, and naphthol type epoxy resin. , naphthalene type epoxy resin, phosphorus-containing epoxy resin, aromatic glycidylamine type epoxy resin, alicyclic epoxy resin, oxazolidinone epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, etc. The epoxy resin may be used alone or in combination of two or more.

The epoxy equivalent of component (2) (i.e., solid epoxy compound) is preferably 50 to 5,000 g/eq, more preferably 100 to 3,000 g/eq, and even more preferably 150 to 1,000 g/eq from the viewpoint of reactivity. The epoxy equivalent here means the number of grams of a compound containing 1 gram equivalent of epoxy groups (unit: g/eq). In other words, the epoxy equivalent means the value obtained by dividing the molecular weight of a compound containing epoxy groups by the number of epoxy groups in the compound, that is, the molecular weight per 1 epoxy group. The epoxy equivalent can be measured according to the method specified in JIS K 7236.

In one embodiment of the present invention, component (2) contains: preferably at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin; preferably at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin. In this embodiment, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin all have two or more epoxy groups in one molecule and are solid at 25°C.

In another aspect of the present invention, component (2) contains: bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, or biphenyl type epoxy resin is preferred; bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, or biphenyl type epoxy resin is more preferred. In this aspect, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin all have two or more epoxy groups in one molecule and are solid at 25°C.

In another aspect of the present invention, component (2) is preferably a bisphenol A type epoxy resin containing two or more epoxy groups in one molecule and being solid at 25°C; preferably, a bisphenol A type epoxy resin containing two or more epoxy groups in one molecule and being solid at 25°C.

The curable composition of the present invention may also contain: a compound having two or more epoxy groups in one molecule and being liquid at 25°C (hereinafter sometimes referred to as "liquid epoxy compound"). However, from the perspective of the effects of the present invention (i.e., excellent light curing and excellent heat curing), the curable composition of the present invention does not contain a liquid epoxy compound, or preferably contains a liquid epoxy compound in an amount of 20 weight parts or less relative to 100 weight parts of component (2) (i.e., solid epoxy compound). The amount of the liquid epoxy compound is preferably 10 weight parts or less, and more preferably 5 weight parts or less relative to 100 weight parts of component (2). It is particularly preferred that the curable composition of the present invention does not contain a liquid epoxy compound.

From the perspective of the curability and operability of the curable composition, the amount of component (2) is preferably 5% by weight or more, more preferably 10% by weight or more, and more preferably 15% by weight or more, and preferably 70% by weight or less, more preferably 60% by weight or less, and more preferably 55% by weight or less, relative to the total amount of the curable composition.

<(3) Polythiol compounds>

The "polythiol compound having two or more alkyl groups in one molecule" used as component (3) in the present invention mainly plays the role of a curing agent that reacts with component (1) by irradiation with light such as ultraviolet rays to cure the composition. The number of alkyl groups in one molecule of the polythiol compound is preferably 2 to 6, more preferably 3 to 6, more preferably 3 to 5, and particularly preferably 3 or 4.

The polythiol compound may be a commercially available product or a compound produced by a known method (e.g., the method described in Japanese Patent Publication No. 2012-153794 or International Publication No. 2001/00698).

Polythiol compounds include partial esters of polyols and alkyl organic acids, and complete esters of polyols and alkyl organic acids. Here, partial esters refer to esters of polyols and carboxylic acids, and a part of the hydroxyl groups of the polyols form ester bonds; complete esters refer to esters of all the hydroxyl groups of the polyols form ester bonds.

Examples of polyols include ethylene glycol, trihydroxymethylethane, trihydroxymethylpropane, pentaerythritol, and dipentaerythritol.

Examples of the alkyl organic acid include alkyl aliphatic monocarboxylic acids such as alkyl acetic acid, alkyl propionic acid (e.g., 3-alkyl propionic acid), alkyl butyric acid (e.g., 3-alkyl butyric acid, 4-alkyl butyric acid); esters containing alkyl and carboxyl groups obtained by esterification of hydroxy acids with alkyl organic acids; alkyl aliphatic dicarboxylic acids such as alkyl succinic acid, dialkyl succinic acid (e.g., 2,3-dialkyl succinic acid); alkyl aromatic monocarboxylic acids such as alkyl benzoic acid (e.g., 4-alkyl benzoic acid); etc. The number of carbon atoms in the alkyl aliphatic monocarboxylic acids is preferably 2 to 8, more preferably 2 to 6, more preferably 2 to 4, and particularly preferably 3. Among the aforementioned butyl organic acids, butyl aliphatic monocarboxylic acids with 2 to 8 carbon atoms are preferred, butyl acetic acid, 3-butyl propionic acid, 3-butyl butyric acid and 4-butyl butyric acid are preferred, and 3-butyl propionic acid is more preferred.

Specific examples of partial esters of polyols and butyl organic acids include trihydroxymethylethane bis(butyl acetate), trihydroxymethylethane bis(3-butyl propionate), trihydroxymethylethane bis(3-butyl butyrate), trihydroxymethylethane bis(4-butyl butyrate), trihydroxymethylpropane bis(butyl acetate), trihydroxymethylpropane bis(3-butyl propionate), trihydroxymethylpropane bis(3-butyl butyrate), trihydroxymethylpropane bis(4-butyl butyrate), pentaerythritol bis(butyl acetate), pentaerythritol bis(3-butyl propionate), pentaerythritol bis(3-butyl butyrate), pentaerythritol bis(4-butyl butyrate). Dipentaerythritol tetra-(4-butyl butyrate), dipentaerythritol tetra-(butyl acetate), dipentaerythritol tetra-(3-butyl propionate), dipentaerythritol tetra-(3-butyl butyrate), dipentaerythritol tetra-(4-butyl butyrate), etc.

Specific examples of the complete esters of the polyol and the butyl organic acid include: ethylene glycol bis(butyl acetate), ethylene glycol bis(3-butyl propionate), ethylene glycol bis(3-butyl butyrate), ethylene glycol bis(4-butyl butyrate), trihydroxymethylethane bis(butyl acetate), trihydroxymethylethane bis(3-butyl propionate), trihydroxymethylethane bis(3-butyl butyrate), trihydroxymethylethane bis(4-butyl butyrate), trihydroxymethylpropane bis(butyl acetate), trihydroxymethylpropane bis(3-butyl propionate), trihydroxymethylpropane bis(3-butyl butyrate), trihydroxymethylpropane bis(4-butyl butyrate), pentaerythritol Tetra(butyl acetate), pentaerythritol tetra(3-butyl propionate), pentaerythritol tetra(3-butyl butyrate), pentaerythritol tetra(4-butyl butyrate), dipentaerythritol tetra(butyl acetate), dipentaerythritol tetra(3-butyl propionate), dipentaerythritol tetra(3-butyl butyrate), dipentaerythritol tetra(4-butyl butyrate), etc.

From the perspective of storage stability, the aforementioned partial esters and complete esters are preferably those with extremely low alkaline impurity content, and those that do not require the use of alkaline substances in manufacturing are preferred.

In addition, as component (3), alkane polythiol compounds such as 1,4-butanedithiol, 1,6-hexanedithiol, 1,10-decanedithiol, etc. can also be used; polyethers containing alkyl groups at the end; polythioethers containing alkyl groups at the end; polythiol compounds obtained by the reaction of epoxy compounds and hydrogen sulfide; polythiol compounds having alkyl groups at the end obtained by the reaction of polythiol compounds and epoxy compounds; etc., which are polythiol compounds produced using alkaline substances as reaction catalysts in their production process. The polythiol compounds produced using alkaline substances are preferably dealkalized to adjust the alkali metal ion concentration to 50 ppm by weight or less before use.

As a desalination treatment of polythiol compounds produced using alkaline substances, for example: dissolving the polythiol compounds in an organic solvent such as acetone or methanol, neutralizing by adding an acid such as dilute hydrochloric acid or dilute sulfuric acid, and then desalting by extraction/washing; using an ion exchange resin adsorption method; purifying by distillation; etc., but not limited to these.

In addition, as component (3), for example, tris[(3-butylpropionyloxy)ethyl]isocyanurate, 1,4-bis(3-butylbutyryloxy)butane, 1,3,5-tris(3-butylbutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, tris(3-butylpropyl)isocyanurate, bis(3-butylpropyl)isocyanurate, 1,3,4,6-tetrakis(2-butylethyl)glycoluril, and 4,4'-isopropylidene diphenyl bis(3-butylpropyl)ether can be used.

Component (3) is preferably a polythiol compound having 2 to 6 thiols in one molecule, 3 to 6 are more preferred, 3 to 5 are even more preferred, and 3 or 4 are particularly preferred.

In one embodiment of the present invention, component (3) comprises: pentaerythritol tetrakis (3-butyl propionate), pentaerythritol tetrakis (3-butyl butyrate), 3-(3-butyl propyl) isocyanurate, trihydroxymethyl propane 3-(3-butyl propionate), dipentaerythritol tert-(3-butyl propionate), 3-[(3-butyl propionyloxy) ethyl] isocyanurate, ethylene glycol bis (butyl acetate), trihydroxymethyl propane 3-(butyl acetate), pentaerythritol Preferably, at least one selected from the group consisting of tetra(butyl acetate), 1,4-bis(3-butylbutyryloxy)butane, 1,3,5-tris(3-butylbutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trihydroxymethylpropane tris(3-butylbutyrate), trihydroxymethylethane tris(3-butylbutyrate), 1,3,4,6-tetra(2-butylethyl)glycoluril, and 4,4'-isopropylidene diphenyl bis(3-butylpropyl) ether; preferably, at least one selected from the group consisting of pentaerythritol tetra(3-butylpropionate), pentaerythritol At least one selected from the group consisting of tetrakis(3-butylbutyrate) and tris(3-butylpropyl)isocyanurate is preferred.

In another embodiment of the present invention, component (3) contains: preferably pentaerythritol tetrakis (3-butyl propionate), pentaerythritol tetrakis (3-butyl butyrate) or tris (3-butyl propyl) isocyanurate; preferably pentaerythritol tetrakis (3-butyl propionate), pentaerythritol tetrakis (3-butyl butyrate) or tris (3-butyl propyl) isocyanurate; more preferably pentaerythritol tetrakis (3-butyl propionate) is more preferably.

From the perspective of curability, the molar ratio of the total of the acryl group, methacryl group and epoxy group in component (1) to the olefin group in component (3) (total of the acryl group, methacryl group and epoxy group in component (2)/olefin group in component (3)) is preferably 0.5 to 2.0, more preferably 0.6 to 1.6, more preferably 0.7 to 1.5, and particularly preferably 0.8 to 1.3.

From the perspective of curability and adhesion, the amount of component (3) must be 15% by weight or more and 50% by weight or less relative to the total curable composition. The amount of component (3) is preferably 20% by weight or more, preferably 25% by weight or more, preferably 45% by weight or less, preferably 40% by weight or less relative to the total curable composition.

From the perspective of the workability of the curable composition, the total amount of components (1) and (3) is preferably 50 weight parts or more, more preferably 60 weight parts or more, and more preferably 70 weight parts or more, relative to 100 weight parts of component (2). On the other hand, from the perspective of adhesion, the total amount of components (1) and (3) is preferably 2,000 weight parts or less, more preferably 1,500 weight parts or less, and more preferably 1,000 weight parts or less, relative to 100 weight parts of component (2).

<(4) Photo-free radical generator>

The photoradical generator used as component (4) in the present invention is not particularly limited. Examples of the photoradical generator include alkylphenone photoradical generators, acylphosphine oxide photoradical generators, oxime ester photoradical generators, α-hydroxy ketone photoradical generators, etc. The photoradical generator is preferably an alkylphenone photoradical generator.

Examples of the alkylphenone-based photoradical generator include 2-hydroxy-2-methyl-1-phenylpropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-[4-(4-morpholinophenyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, benzophenone, methylbenzophenone, o-benzoylbenzoic acid, benzoylethyl ether, 2,2-diethoxy, 2 ,4-diethylthiodone, diphenyl-(2,4,6-trimethylbenzyl)phosphine oxide, ethyl-(2,4,6-trimethylbenzyl)phenyl phosphinate, 4,4'-bis(diethylamino)benzophenone, 1-hydroxycyclohexylphenylketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-(4-isopropenylphenyl)-2-methylpropane-1-one oligomers, etc.

Examples of acylphosphine oxide-based photoradical generators include 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzyl)-phenyl-phosphine oxide, etc.

Examples of oxime ester photoradical generators include: 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime), 1-[6-(2-methylbenzoyl)-9-ethyl-9H-carbazole-3-yl]ethanone O-acetyl oxime, etc.

Examples of α-hydroxy ketone-based photoradical generators include benzoin, benzoin methyl ether, benzoin butyl ether, 1-hydroxycyclohexyl phenyl ketone, 1-phenyl-2-hydroxy-2-methylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, and 1-hydroxycyclohexyl phenyl ketone.

Examples of commercially available photo-radical generators include: "Irgacure 1173" (2-hydroxy-2-methyl-1-phenylpropane-1-one) manufactured by BASF, "Irgacure OXE01" (1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyl oxime)), "Irgacure OXE02" (1-[6-(2-methylbenzoyl)-9-ethyl-9H-carbazole-3-yl)ethanone O-acetyl oxime), "Esacure KTO" manufactured by IGM Resins B.V. 46" (a mixture of 2,4,6-trimethylbenzyldiphenylphosphine oxide and oligomeric [2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane] and methylbenzophenone derivatives), "Esacure KIP 150" (an oligomer of 2-hydroxy-1-(4-isopropenylphenyl)-2-methylpropane-1-one), etc.

The amount of component (4) is preferably 0.001% by weight or more, more preferably 0.01% by weight or more, and more preferably 0.1% by weight or more, relative to the total curable composition, from the perspective of obtaining a curable composition that can be photocured efficiently when irradiated with light. In addition, from the perspective of suppressing the outgassing caused by the residual photo-radical generator or its decomposition products in the cured product, it is preferably 10% by weight or less, more preferably 5% by weight or less, and more preferably 2% by weight or less, relative to the total curable composition.

<(5) Latent hardener>

The so-called latent curing agent used as component (5) in the present invention refers to an additive known in the field of epoxy resins, etc., which does not cure epoxy resins at room temperature (25°C) but can cure epoxy resins, etc. by heating.

Examples of latent curing agents include imidazole compounds that are solid at room temperature, amine-epoxy adduct compounds (reaction products of amine compounds and epoxy compounds), and amine-isocyanate adduct compounds (reaction products of amine compounds and isocyanate compounds).

Examples of imidazole compounds that are solid at room temperature include 2-heptadecylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, 2,4-diamino-6 -[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine isocyanuric acid adduct, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl- 2-methylimidazole-trimellitate, 1-cyanoethyl-2-phenylimidazole-trimellitate, N-(2-methylimidazolyl-1-ethyl)-urea, etc.

Examples of epoxy compounds used as raw materials for the amine-epoxy adduct compounds include polyglycidyl ethers obtained by reacting polyphenols such as bisphenol A, bisphenol F, catechol, and resorcinol, or polyols such as glycerol or polyethylene glycol with epichlorohydrin; glycidyl ether esters obtained by reacting hydroxy acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin; polyols such as phthalic acid and terephthalic acid; Polyglycidyl esters obtained by the reaction of carboxylic acid and epichlorohydrin; glycidylamine compounds obtained by the reaction of 4,4'-diaminodiphenylmethane or m-aminophenol and epichlorohydrin; in addition, multifunctional epoxy compounds such as epoxidized phenol novolac resin, epoxidized cresol novolac resin, epoxidized polyolefin, or monofunctional epoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, methacrylate glycidyl ester, etc.; etc.

The amine compound used as a raw material of the amine-epoxy adduct compound or the amine-isocyanate adduct compound has only to have one or more active hydrogen atoms capable of undergoing addition reaction with an epoxy group or an isocyanate group (also known as isocyanate group) in one molecule and one or more amino groups (at least one of a primary amino group, a secondary amino group and a tertiary amino group) in one molecule. Examples of such amine compounds include: aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4'-diamino-dicyclohexyl; aromatic amine compounds such as 4,4'-diaminodiphenylmethane, 2-methylaniline; heterocyclic compounds containing nitrogen atoms such as 2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine, piperazine, etc.; etc.

In addition, if a compound with a tertiary amine group is used, an excellent latent hardener can be produced. Examples of the compound having a tertiary amino group include amines having a tertiary amine such as dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine, 2-methylimidazole, 2-ethylimino, 2-ethyl-4-methylimidazole, and 2-phenylimidazole; 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, and 1-(2- 1-(2-Hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-Hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-Hydroxy-3-butoxypropyl)-2-methylimidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-hydroxypyrrolidone, Alcohols, phenols, thiols, carboxylic acids and hydrazides with tertiary amines such as pyridine, 2-benzimidazole, 2-butylbenzimidazole, 2-butylbenzothiazole, 4-butylpyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, niacin, isonicotinic acid, picolinic acid, N,N-dimethylglycine hydrazide, N,N-dimethylpropionic acid hydrazide, niacin hydrazide, isonicotinic acid hydrazide, etc.; etc.

When an amine-epoxy adduct compound is produced by an addition reaction between an epoxy compound and an amine compound, an active hydrogen compound having two or more active hydrogen atoms in one molecule may be added. Examples of such active hydrogen compounds include polyphenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, phenol novolac resin, polyols such as trihydroxymethylpropane, polycarboxylic acids such as adipic acid and phthalic acid, 1,2-dibutyl ethane, 2-butyl ethanol, 1-butyl-3-phenoxy-2-propanol, butyl acetic acid, phthalic acid, lactic acid, etc.

Examples of the isocyanate compound used as a raw material for the amine-isocyanate adduct compound include monofunctional isocyanate compounds such as butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, benzyl isocyanate, etc.; hexamethylene diisocyanate, toluene diisocyanate (e.g., 2,4-toluene diisocyanate, 2,6-toluene diisocyanate), 1,5-naphthalene diisocyanate, etc. ester, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, dicycloheptane triisocyanate, etc.; in addition, a terminal isocyanate group-containing compound obtained by the reaction of such a multifunctional isocyanate compound with an active hydrogen compound; etc. Examples of such terminal isocyanate group-containing compounds include an addition compound having an isocyanate group at the terminal obtained by the reaction of toluene diisocyanate and trihydroxymethylpropane, an addition compound having an isocyanate group at the terminal obtained by the reaction of toluene diisocyanate and pentaerythritol, etc.

Latent curing agents can be easily obtained by, for example, appropriately mixing the above-mentioned raw materials, reacting them at a temperature of 20°C to 200°C, and then grinding them after cooling and solidification, or by reacting the above-mentioned raw materials in a solvent such as methyl ethyl ketone, dioxane, tetrahydrofuran, etc., removing the solvent, and then grinding the solids.

As the latent hardener, commercial products can also be used. Examples of commercial products of amine-epoxy adduct compounds include "Amicure PN-23", "Amicure PN-40", "Amicure PN-50", and "Amicure PN-H" manufactured by Ajinomoto Fine-Techno Co., Ltd., "Hardener X-3661S" and "Hardener X-3670S" manufactured by ACR Co., Ltd., and "Novacure HX-3742" and "Novacure HX-3721" manufactured by Asahi Kasei Corporation. In addition, commercially available products of amine-isocyanate adduct compounds include, for example, "Fujicure FXR-1000", "Fujicure FXR-1030", "Fujicure FXR-1020", "Fujicure FXR-1030", "Fujicure FXR-1081", and "Fujicure FXR-1121" manufactured by T&K TOKA.

Component (5) preferably contains an amine-epoxy adduct compound and/or an amine-isocyanate adduct compound, more preferably an amine-epoxy adduct compound and/or an amine-isocyanate adduct compound, more preferably an amine-epoxy adduct compound or an amine-isocyanate adduct compound, and particularly preferably an amine-epoxy adduct compound.

From the perspective of heat-induced curing, the amount of component (5) is preferably 1% by weight or more, more preferably 2% by weight or more, and more preferably 3% by weight or more relative to the total curable composition. Furthermore, from the perspective of storage stability, the weight of component (5) is preferably 20% by weight or less, more preferably 15% by weight or less, and more preferably 10% by weight or less relative to the total curable composition.

<(6)Stabilizer>

From the viewpoint of storage stability, the curable composition of the present invention may also contain a stabilizer as component (6). Examples of the stabilizer include borate compounds, titanium ester compounds, aluminum ester compounds, zirconate compounds, isocyanate compounds, etc.

As mentioned above, the phosphoric acid-modified (meth)acrylate of one of the components (1) has the function of improving the storage stability of the curable composition. Therefore, from the perspective of storage stability, the curable composition of the present invention preferably contains phosphoric acid-modified (meth)acrylate as component (1) and/or contains a stabilizer as component (6).

Examples of borate compounds include trimethyl borate, triethyl borate, tri-n-propyl borate, tri-isopropyl borate, tri-n-butyl borate, tripentyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, tricyclooctyl borate, trinonyl borate, tridecyl borate, trilauryl borate, tri-hexadecyl borate, tri-octadecyl borate, tris(2-ethylhexyloxy) borane, tribenzyl borate, triphenyl borate, tri-o-tolyl borate, tri-m-tolyl borate, triethanolamine borate, etc.

Examples of titanium ester compounds include tetraethyl titanium ester, tetrapropyl titanium ester, tetraisopropyl titanium ester, tetrabutyl titanium ester, tetraoctyl titanium ester, etc.

Examples of aluminate compounds include triethyl aluminate, tripropyl aluminate, triisopropyl aluminate, tributyl aluminate, trioctyl aluminate, etc.

Examples of zirconate compounds include tetraethyl zirconate, tetrapropyl zirconate, tetraisopropyl zirconate, tetrabutyl zirconate, etc.

Examples of the isocyanate compound include n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, 2-ethylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, 2,4-toluene diisocyanate, toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, tolidine diisocyanate, isophorone diisocyanate, xylylene diisocyanate, p-phenylene diisocyanate, dicycloheptane triisocyanate, etc.

As a stabilizer, from the perspective of the versatility of the stabilizer and the storage stability of the curing composition, borate compounds are preferred, triethyl borate, tri-n-propyl borate, tri-isopropyl borate and tri-n-butyl borate are preferred, and triethyl borate is more preferred.

When component (6) is used, its amount is not particularly limited, but from the perspective of storage stability, its amount is preferably 0.001% by weight or more, preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 5% by weight or less, preferably 3% by weight or less, and more preferably 2% by weight or less relative to the entire curable composition.

In a preferred embodiment of the present invention, the curable composition of the present invention contains at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate and dipentaerythritol hexa(meth)acrylate as component (1), and the curable composition of the present invention contains phosphoric acid-modified (meth)acrylate as component (1), and/or contains a stabilizer as component (6). In this embodiment, the stabilizer is preferably a borate compound, preferably at least one selected from the group consisting of triethyl borate, tri-n-propyl borate, tri-isopropyl borate and tri-n-butyl borate, and more preferably triethyl borate.

In another preferred embodiment of the present invention, component (1) is a mixture of at least one selected from the group consisting of tricyclodecanedimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and phosphoric acid-modified (meth)acrylate.

In another preferred embodiment of the present invention, component (1) is at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and the curable composition of the present invention contains a stabilizer as component (6). In this embodiment, the stabilizer is preferably a borate compound, preferably at least one selected from the group consisting of triethyl borate, tri-n-propyl borate, tri-isopropyl borate and tri-n-butyl borate, and more preferably triethyl borate.

In another preferred embodiment of the present invention, component (1) is a mixture of at least one selected from the group consisting of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate and dipentaerythritol hexa(meth)acrylate and phosphoric acid-modified (meth)acrylate, and the curable composition of the present invention contains a stabilizer as component (6). In this embodiment, the stabilizer is preferably a borate compound, preferably at least one selected from the group consisting of triethyl borate, tri-n-propyl borate, tri-isopropyl borate and tri-n-butyl borate, and more preferably triethyl borate.

In another preferred embodiment of the present invention, the curable composition of the present invention contains tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate or dipentaerythritol hexa(meth)acrylate as component (1), and the curable composition of the present invention contains phosphoric acid-modified (meth)acrylate as component (1), and/or contains a stabilizer as component (6). In this embodiment, the stabilizer is preferably a borate compound, preferably at least one selected from the group consisting of triethyl borate, tri-n-propyl borate, tri-isopropyl borate, and tri-n-butyl borate, and more preferably triethyl borate.

In another preferred embodiment of the present invention, component (1) is a mixture of tricyclodecanedimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate or dipentaerythritol hexa(meth)acrylate, and phosphoric acid-modified (meth)acrylate.

In another preferred embodiment of the present invention, component (1) is tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate or dipentaerythritol hexa(meth)acrylate, and the curable composition of the present invention contains a stabilizer as component (6). In this embodiment, the stabilizer is preferably a borate compound, preferably at least one selected from the group consisting of triethyl borate, tri-n-propyl borate, tri-isopropyl borate, and tri-n-butyl borate, and more preferably triethyl borate.

In another preferred embodiment of the present invention, component (1) is a mixture of tricyclodecane dimethanol di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate or dipentaerythritol hexa(meth)acrylate, and phosphoric acid-modified (meth)acrylate, and the curable composition of the present invention contains a stabilizer as component (6). In this embodiment, the stabilizer is preferably a borate compound, preferably at least one selected from the group consisting of triethyl borate, tri-n-propyl borate, tri-isopropyl borate, and tri-n-butyl borate, and more preferably triethyl borate.

<Other ingredients>

The curable composition of the present invention may contain other components different from the above components within the range not impairing the effects of the present invention. Other components include, for example: polymerization inhibitors (e.g., butylated hydroxytoluene, barbituric acid); antioxidants; inorganic fillers (e.g., calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (aluminum), zinc oxide, silicon dioxide, potassium titanium oxide, kaolin, talc, quartz powder, etc.); organic fillers formed by copolymers formed by polymerizing monomers that can be polymerized with monomers constituting polymethyl methacrylate and/or polystyrene; thixotropic agents; defoaming agents; leveling agents; coupling agents; flame retardants; pigments; dyes; fluorescent agents, etc. Other components can be used alone or in combination of two or more.

<Manufacturing and curing of curable compositions>

The curable composition of the present invention can be prepared into a single-liquid curable composition by uniformly mixing the components using, for example, a kneader, a stirring mixer, a three-roll grinder, etc. The temperature of the curable composition during mixing is usually 10~50℃, preferably 20~40℃.

The light irradiated during the photocuring of the curable composition of the present invention is preferably ultraviolet light. The peak wavelength of the irradiated light is preferably 300-500 nm. The illuminance of the irradiated light is preferably 100-5,000 mW/cm ² , preferably 300-4,000 mW/cm ^2. The exposure amount is preferably 500-3,000 mJ/cm ² , preferably 1,000-3,000 mJ/cm ² .

Examples of light irradiation methods include: low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, excimer lasers, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, sodium lamps, fluorescent lamps, LED-type SPOT-type UV irradiators, xenon lamps, DEEP UV lamps, etc.

The heating temperature for the curable composition of the present invention during thermal curing is not particularly limited, but is, for example, 50 to 150°C, preferably 60 to 100°C. The curable composition of the present invention has excellent low-temperature curing properties, and can exhibit excellent thermal curing properties even at a relatively low curing temperature below 100°C. The heating time for the curable composition of the present invention during thermal curing is not particularly limited, but is, for example, 10 to 120 minutes, preferably 30 to 60 minutes.

<Use of hardening composition>

The curable composition of the present invention has both excellent light curing and excellent heat curing properties, and can form a cured product with high bonding strength, so it is useful as an adhesive, sealant, coating agent, etc. Therefore, the present invention also provides an adhesive, sealant and coating agent containing the aforementioned curable composition. As an adhesive, it is preferably used for bonding between components of a camera module.

<Camera module manufacturing method>

The present invention provides a method for manufacturing a camera module, comprising the following steps (I) to (III): (I) a step of positioning a first connecting part and a second connecting part coated with a curable composition of the present invention; (II) a step of temporarily fixing the first connecting part and the second connecting part by curing the curable composition by irradiating light; and (III) a step of formally fixing the first connecting part and the second connecting part by curing the curable composition by heating.

The first connecting part here refers to a part that has been coated with the curable composition of the present invention, and the second connecting part refers to another part to be connected with the first connecting part. The second connecting part may be coated with the curable composition of the present invention or may not be coated.

According to the manufacturing method of the present invention, each part can be positioned with high precision, and the first connecting part and the second connecting part can be connected with high bonding strength, resulting in efficient manufacturing of high-quality camera modules.

In step (II), due to the arrangement of the first and second connecting parts, the applied curable composition still has many un-irradiated parts. However, since the curable composition of the present invention has good thermal curing properties, even the un-irradiated parts can be fully cured by thermal curing in step (III) to achieve full curing, and a cured product with high bonding strength can be formed from the entire coated curable composition.

The conditions of light irradiation in process (II) and heating in process (III) in the manufacturing method of the camera module of the present invention are the same as those described above.

[Implementation example]

The present invention is described in more detail below based on embodiments and comparative examples, but the present invention is not limited to the following embodiments.

1. Raw materials <Component (1): Compound having a (meth)acryloyl group>

(1A) IRR-214K: Tricyclodecanedimethanol diacrylate manufactured by DAICEL-ALLNEX, molecular weight: 300, number of acryl groups in one molecule: 2

(1B) EBECRYL150: EO modified bisphenol A diacrylate manufactured by DAICEL-ALLNEX, molecular weight: 512, number of acryl groups in one molecule: 2

(1C) DPHA: Dipentaerythritol hexaacrylate manufactured by DAICEL-ALLNEX, molecular weight 524, number of acryl groups in one molecule: 6

(1D) EBECRYL168: manufactured by DAICEL-ALLNEX, phosphoric acid-modified methacrylate, molecular weight: 270, number of methacrylic groups in one molecule: 1.5

<Ingredient (2): Solid epoxy compound>

(2A) jER1001: Bisphenol A epoxy resin manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight (EPW): 475 g/eq, softening point: 64°C, number of epoxy groups in one molecule: 2

(2B) jER4005P: Bisphenol F type epoxy resin manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight (EPW): 538 g/eq, softening point: 87°C, number of epoxy groups in one molecule: 2

(2C) HP-7200: Dicyclopentadiene epoxy resin manufactured by DIC Corporation, epoxy equivalent weight (EPW): 258g/eq, softening point: 56~66℃, number of epoxy groups in one molecule: 2~3

(2D) YX4000H: Biphenyl type epoxy resin manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight (EPW): 192g/eq, melting point: 105℃, number of epoxy groups in one molecule: 2

<Component (2'): Liquid epoxy compound>

(2’A) EX-211: Neopentyl glycol diglycidyl ether manufactured by Nagase ChemteX Co., Ltd., epoxy equivalent weight (EPW): 138 g/eq, liquid at 25°C, number of epoxy groups in one molecule: 2

(2’B) jER828EL: Bisphenol A epoxy resin manufactured by Mitsubishi Chemical Corporation, epoxide equivalent weight (EPW): 190 g/eq, liquid at 25°C, number of epoxy groups in one molecule: 2

(2’C) EXA-4816: Aliphatic modified bisphenol A type epoxy resin manufactured by DIC Corporation, epoxy equivalent weight (EPW) 403 g/eq, liquid at 25°C, number of epoxy groups in one molecule: 2

(2’D) BF-1000: Epoxy 1,2-polybutadiene manufactured by ADEKA Co., Ltd., Epoxy equivalent weight (EPW): 210 g/eq, liquid at 25°C, number of epoxy groups in one molecule: 5

<Ingredient (3): Polythiol compound>

(3A) PEMP: Pentaerythritol tetra(3-butyl propionate) manufactured by SC Organic Chemicals Co., Ltd., molecular weight: 489, number of butyl groups in one molecule: 4

(3B) PE1: "Karenz MT" pentaerythritol tetra(3-butylbutyrate) manufactured by Showa Denko Co., Ltd., molecular weight: 544, number of butyl groups in one molecule: 4

(3C)TMPIC: Tris(3-butylpropyl)isocyanurate, molecular weight: 351, number of butyl groups in one molecule: 3

<Ingredient (4): Photoradical generator>

(4A) Irgacure 1173: manufactured by BASF, 2-hydroxy-2-methyl-1-phenylpropane-1-one

(4B) Esacure KIP 150: manufactured by IGM Resins B.V., oligomer of 2-hydroxy-1-(4-isopropenylphenyl)-2-methylpropane-1-one

<Ingredient (5): Latent hardener>

(5A) PN-23: Amine-epoxy adduct compound manufactured by Ajinomoto Fine-Techno Co., Ltd.

(5B)FXR1081: Amine-isocyanate adduct compound manufactured by T&K TOKA Co., Ltd.

<Ingredient (6): Stabilizer>

(6A) Triethyl borate: manufactured by Tokyo Chemical Industry Co., Ltd.

2. Evaluation test <Next, strength measurement> (1) Determination of adhesion strength 1 after light curing

The curable composition was applied in an amount of 1 to 3 mg on a 100 mm × 25 mm × 2 mm thick liquid crystal polymer (LCP) plate (CM-301B manufactured by JX Nippon Mining and Energy Co., Ltd.), and a chip capacitor (JIS nominal 2012 size) was placed on it. The photocuring was performed under the following conditions, and the adhesion strength 1 of the cured product was measured and evaluated according to the following criteria.

(2) Determination of adhesion strength 2 after light and heat curing

Similar to the above, the LCP board was coated with a curable composition and a chip capacitor was placed on it. It was then light and heat cured under the following conditions, and the bonding strength of the cured product was measured and evaluated according to the following criteria.

(3) Measurement of adhesion strength 3 after thermal curing

Similar to the above, the LCP board was coated with a curable composition and a chip capacitor was placed on it. It was then thermally cured under the following conditions, and the bonding strength of the cured product was measured and evaluated based on the following criteria.

The bonding strength (N/mm ² ) was measured by breaking the chip capacitor in the horizontal direction using a bond tester (Dega series 4000). The measurement was performed three times and the average value was calculated.

<Evaluation of thermal curing properties>

A hole with a diameter of 5 mm was opened on a 30 mm × 50 mm × 2 mm thick silicone sheet (manufactured by AS ONE), and a curable composition was filled in an amount of 1 to 3 mg, and thermally cured under the following conditions. The thermal curability was evaluated according to the following criteria by a finger test of the cured product.

<Hardening conditions> (1) Photohardening

Using UV-LED irradiation device UJ35 manufactured by Panasonic, ultraviolet rays (peak wavelength: 365nm) with an illuminance of 2500mW/ ^cm2 were irradiated to the curable composition from two directions at an angle of 45° (the incident angle of light on the chip capacitor surface was 45°) for 1.0 second (exposure dose 2500mJ/ ^cm2 ).

(2) Light and heat curing

Using the UV-LED irradiation device UJ35 manufactured by Panasonic, ultraviolet light (peak wavelength: 365nm) with an illuminance of 2500mW/ ^cm2 was irradiated to the curable composition from two directions at an angle of 45° (the incident angle of light on the surface of the chip capacitor was 45°) for 1.0 second (exposure dose 2500mJ/ ^cm2 ). Next, the irradiated curable composition was heated in a hot air circulation oven at 100°C for 30 minutes.

(3) Heat hardening

Heat the curable composition in a hot air circulation oven at 100°C for 30 minutes.

<Evaluation criteria> (1) Evaluation criteria for adhesion strength 1 after light curing

◎: 10N/mm2 or ^more

○: 5N/ ^mm2 or more but less than 10N/ ^mm2

×: less than 5N/ ^mm2

(2) Evaluation criteria for adhesion strength after light and heat curing 2

◎: 30N/mm2 or ^more

○: 15N/ ^mm2 or more but less than 30N/ ^mm2

×: less than 15N/ ^mm2

(3) Evaluation criteria for adhesion strength 3 after thermal curing

◎: 30N/mm2 or ^more

○: 15N/ ^mm2 or more but less than 30N/ ^mm2

×: less than 15N/ ^mm2

(4) Evaluation criteria for thermal curing properties

◎: After touching, the appearance of the hardened material still does not change.

○: After touching, the hardened material has some marks on its surface.

×: Significant depressions were observed on the hardened product.

3. Implementation examples and comparative examples

The curable compositions of Examples 1 to 14 and Comparative Examples 1 to 7 were prepared by mixing the components in the amounts shown in the upper column of the following table. In addition, "parts" in the table represent "parts by weight" and "%" represents "% by weight". In the following table, the "molar ratio of the total of the acryl group, methacryl group and epoxy group in component (2) to the phenyl group in component (3)" is recorded in the "((meth)acryl group + epoxy group)/phenyl group" column, and the "amount of component (3) relative to the whole curable composition" is recorded in the "amount of component (3)" column.

In Examples 1 to 13 and Comparative Example 7, components (1) and (2) are mixed and dissolved at 100°C, fully cooled to room temperature (20 to 25°C), component (5) is added thereto and fully dispersed, components (3) and (4) are added thereto and mixed, and then left to stand to remove bubbles, thereby preparing a curable composition. In addition, preparation operations other than mixing and dissolving components (1) and (2) are performed at room temperature.

In Example 14, components (1) and (2) are mixed and dissolved at 100°C, and then fully cooled to room temperature (20-25°C), component (5) is added thereto and fully dispersed, components (3) and (4) are added thereto and mixed, component (6) is added thereto and mixed, and then left to stand to remove bubbles, thereby preparing a curable composition. In addition, preparation operations other than mixing and dissolving components (1) and (2) are performed at room temperature.

In Comparative Example 1, component (5) is added to component (1) and fully dispersed, and components (3) and (4) are added thereto and mixed, and then left to stand to remove bubbles, thereby preparing a curable composition. In addition, the preparation operation is carried out at room temperature.

In Comparative Examples 2 to 5, components (1) and (2') are mixed, component (5) is added thereto and fully dispersed, components (3) and (4) are added thereto and mixed, and then left to stand to remove bubbles, thereby preparing a curable composition. In addition, the preparation process is carried out at room temperature.

In Comparative Example 6, components (1) and (2) are mixed and dissolved at 100°C, and after being fully cooled to room temperature (20-25°C), component (5) is added thereto and fully dispersed, component (4) is added thereto and mixed, and then left to stand to remove bubbles, thereby preparing a curable composition. In addition, preparation operations other than mixing and dissolving components (1) and (2) are performed at room temperature.

The results of the evaluation tests of the curable compositions of Examples 1 to 14 and Comparative Examples 1 to 7 are shown in the table below.

From the results of Examples 1 to 14, it can be seen that the curable composition of the present invention has both excellent thermosetting and excellent photocuring properties. Therefore, depending on the use environment or application, curing by heat application and curing by light irradiation can be selectively implemented, or both can be combined and implemented. In addition, the cured material obtained by curing has a high bonding strength per unit area, and is useful as an adhesive for bonding between components in a camera module. In contrast, the curable compositions of Examples 1 to 7 are insufficient in either thermosetting or photocuring properties. In particular, the curable composition of Example 6 that does not contain component (3) and the curable composition of Example 7 that contains a smaller amount of component (3) are insufficient in thermosetting properties.

[Possibility of industrial application]

The curable composition of the present invention is useful as an adhesive, sealant, coating agent (especially an adhesive used in the manufacture of camera modules), etc.

Claims (9)

A curable composition comprises the following components (1) to (5): (1) a compound having a (meth)acryl group; (2) an epoxy compound having two or more epoxy groups in one molecule and being solid at 25° C.; (3) a polythiol compound having two or more alkyl groups in one molecule; (4) a photoradical generator; and (5) a latent curing agent; wherein the amount of component (3) is The content of the curable composition is 15% by weight or more and 50% by weight or less, and the molar ratio of the total of the acryl group, methacryl group and epoxy group in component (1) and the butyl group in component (2) (the total of the acryl group, methacryl group and epoxy group in component (2)/butyl group in component (3)) is 0.5 to 2.0. The curable composition as described in claim 1, wherein component (2) contains at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type epoxy resin. The curable composition as described in claim 1 or 2, wherein component (3) contains: a polythiol compound having 2 to 6 thiols in one molecule. The curable composition as described in claim 1 or 2, wherein component (5) contains an amine-epoxy adduct compound and/or an amine-isocyanate adduct compound. An adhesive containing a hardening composition as described in any one of claim items 1 to 4. The adhesive described in claim 5 is used for bonding components of a camera module. A sealant containing a hardening composition as described in any one of claim items 1 to 4. A coating agent comprising a hardening composition as described in any one of claim items 1 to 4. A method for manufacturing a camera module comprises the following steps (I) to (III): (I) a step of positioning a first connecting part and a second connecting part coated with a curable composition as described in any one of claims 1 to 4; (II) a step of temporarily fixing the first connecting part and the second connecting part by curing the curable composition by irradiating light; and (III) a step of formally fixing the first connecting part and the second connecting part by curing the curable composition by heating.