WO2019069798A1 - Cleaning resin composition for injection molding machines and molds - Google Patents

Abstract

An object of the present invention is to provide a cleaning agent resin composition for an injection molding machine and a mold, which is excellent in thermal stability, and also excellent in cleaning property and substitution property. The injection molding machine and the cleaning resin composition for a mold according to the present invention are characterized by containing a thermoplastic resin and a surfactant having a TGA decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C.

Description

Injection molding machine and cleaner resin composition for mold

The present invention relates to an injection molding machine and a cleaning resin composition for a mold.

Generally, resin molding machines such as injection molding machines are used for operations such as molding of resin. In this type of molding machine, at the end of a predetermined operation, the resin used in the operation, additives such as dyes and pigments, and residual substances of raw materials (eg, thermal decomposition products, carbides, etc.) Remain in When these residues are left to stand, they may be mixed at the time of work to be performed later, which may cause appearance defects of the resulting molded product. Therefore, it is desirable to remove the residue substantially completely from within the molding machine.

As a method of removing the residue from the inside of the molding machine, a method of supplying a cleaning agent to the molding machine and performing cleaning, etc. are carried out. As the cleaning agent, for example, a cleaning agent containing a thermoplastic resin is known (see Patent Documents 1 to 5).

JP-A-9-208754 JP, 2009-107160, A JP, 2013-154484, A JP, 2013-155211, A JP 2014-077049 A

In cleaning of a molding machine using a cleaning agent, from the viewpoint of working efficiency, it is desired to carry out conditions such as the temperature of the molding machine at the time of cleaning without largely changing the conditions at the time of molding. However, conventional detergents may discolor when they are washed at high temperature, and further improvement in heat stability is required, and detergents excellent in heat stability, cleanability and substitution. Is currently required.

Therefore, an object of the present invention is to provide a cleaning resin composition for an injection molding machine and a mold, which is excellent in thermal stability and excellent in cleaning property and substitution property.

That is, the present invention is as follows.

[1]
An injection molding machine and a detergent resin composition for a mold, comprising a thermoplastic resin and a surfactant having a decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C. of TGA.

[2]
[1] The injection molding machine and the cleaner resin composition for a mold according to [1], wherein the surfactant is a sulfonate.

[3]
The injection molding machine and the cleaner resin composition for a mold according to [1] or [2], wherein the surfactant is an alpha sulfo fatty acid methyl ester salt.

[4]
The injection molding machine and the cleaner for a mold according to any one of [1] to [3], wherein the content of the surfactant is 1 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin. Resin composition.

[5]
The resin composition for injection molding machine and mold according to any one of [1] to [4], which further contains a phosphate and / or a condensed phosphate.

[6]
The injection molding machine and mold according to [5], wherein the phosphate is disodium hydrogen phosphate, and the condensed phosphate is at least one selected from the group consisting of sodium metaphosphate and sodium pyrophosphate Cleaning resin composition.

[7]
The injection molding machine according to [5] or [6], wherein the content of the phosphate or the condensed phosphate is 0.05 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic resin Mold cleaning resin composition.

[8]
The injection molding machine according to any one of [1] to [7], wherein the melt flow rate measured under conditions of a temperature of 230 ° C. and a load of 2.16 kgf according to ISO R1133 is 1 to 30 g / 10 min. Mold cleaning resin composition.

[9]
The injection molding machine and the cleaner resin composition for a mold according to any one of [1] to [8], wherein the thermoplastic resin contains an olefin resin.

[10]
Cleaning a hot runner mold while melting a thermoplastic resin, an injection molding machine containing a surfactant having a decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C. and a melting point less than 100 ° C. And a method of using the cleaning resin composition for injection molding machine and mold.

According to the present invention, since it has the above-mentioned configuration, a cleaning agent resin composition for an injection molding machine and a mold can be provided which is excellent in thermal stability, and also excellent in cleaning property and substitution property.

Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the invention.

[Detergent resin composition]
The injection molding machine and the cleaner resin composition for a mold of the present embodiment contain a thermoplastic resin and a surfactant having a TGA decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C.
Moreover, it is preferable that the injection molding machine and the cleaning agent resin composition for metal mold | dies of this embodiment contain a thermoplastic resin, a sulfonate, and a phosphate and / or a condensation phosphate at least. The detergent resin composition of the present embodiment may further contain an inorganic filler, an additive and the like.
In addition, in this specification, the injection molding machine and the cleaning agent resin composition for metal mold | dies may only be called a "cleaning agent resin composition."

(Thermoplastic resin)
Examples of thermoplastic resins include polyethylenes such as low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and olefins such as polypropylene (PP) and propylene-ethylene copolymer. Resins: polystyrene (PS), high impact polystyrene (HIPS), acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), methyl methacrylate-butadiene-styrene resin (MBS resin), butyl acrylate-acrylonitrile -Styrene resin such as styrene resin (AAS resin); polyamide resin; polycarbonate; (meth) acrylic resin such as polymethyl methacrylate; polyester; polyarylate; Ethylene (Asahi Glass Co., Ltd. Fluon PTFE fine powder CD097E etc.), tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polytetrafluoroethylene mixed with acrylic resin and copolymer thereof And fluorine resins such as Among these, from the viewpoint of further improving the washability and the substitution, an olefin resin is preferably contained, polyethylene and / or polypropylene are more preferably contained, and polyethylene is particularly preferably contained.
Here, the said olefin resin and the said styrene resin mean resin whose content of the structural unit originating in an olefin or a styrene-type monomer is 50 mass% or more with respect to the total mass of resin.
In addition, a thermoplastic resin can be used individually by 1 type or in combination of 2 or more types. Here, when two or more thermoplastic resins are used in combination, two or more thermoplastic resins having different structures can be used in combination, and two or more thermoplastic resins having different molecular weights may be used in combination. You can also

As the thermoplastic resin, at least a first thermoplastic resin (A), a thermoplastic resin incompatible with the first thermoplastic resin (B), and a fluorine-based resin, from the viewpoint of being more excellent in the cleaning property and the substitution property. It is preferable to contain resin (C). Copolymers containing ethylene as a structural unit such as ethylene-ethyl acrylate (EEA), ethylene-methacrylate (EMA), ethylene-methyl methacrylate (EMMA), ethylene-butyl acrylate (EBA), etc. It is not preferable because coalescence tends to adhere to and remain on the metal. In particular, when the copolymer and the fluorine-based resin (C) are used in combination, the effect of adding the fluorine-based resin (C) is hardly obtained, which is not preferable.
A thermoplastic resin (A), a thermoplastic resin (B), and a fluorine resin (C) can be used individually by 1 type or in combination of 2 or more types.

As a combination of the thermoplastic resin (A) and the thermoplastic resin (B), a combination of an olefin resin and a styrene resin, a combination of a methacrylate ester resin and an olefin resin, a polycarbonate and an olefin resin Combinations and the like can be mentioned, and among them, from the viewpoint of being more excellent in detergency and substitution, a combination of an olefin resin and a styrene resin is preferable, a combination of PE and PS, a combination of PP and PS, PE and AS resin And the combination of PP and AS resin are more preferable, and from the viewpoint of achieving particularly remarkable effects of washing and substitution, a combination of PE and AS resin, and a combination of PP and AS resin are preferable.
With respect to the mixing ratio of the thermoplastic resin (A) and the thermoplastic resin (B), the mass of the thermoplastic resin (B) relative to 100 parts by mass of the thermoplastic resin (A) from the viewpoint of further improving the washability and the substitution property. The proportion is preferably 0.5 to 30 parts by mass, and more preferably 1 to 10 parts by mass from the viewpoint of further reducing the residual amount in the molding machine after cleaning.

As the fluorine-based resin (C), the above-mentioned fluorine-based resin is mentioned, and in particular, from the viewpoint of being able to further improve the cleaning property and the substitution property and suppressing the generation of the fine powder in the cleaning resin composition. And polytetrafluoroethylene mixed with an acrylic resin is preferable.
As content of a fluorine resin (C), it is 0. 0 mass with respect to the total mass (100 mass parts) of a thermoplastic resin (A) and a thermoplastic resin (B) from a viewpoint of the balance of washability and substitution property. The amount is preferably 5 to 20 parts by mass, more preferably 0.5 to 5 parts by mass.

The melt flow rate of the thermoplastic resin is preferably 10 to 200 g / 10 min, more preferably 15 to 150 g / 10 min, from the viewpoint of further improving the flowability and the cleaning properties of the detergent resin composition. More preferably, it is 20 to 100 g / 10 min, particularly preferably 25 to 70 g / 10 min, and most preferably 25 to 60 g / 10 min.
Here, the melt flow rate of the thermoplastic resin means the arithmetic mean (arithmetic average) of all the thermoplastic resins contained in the detergent resin composition of the present embodiment. Therefore, in the case of using one type of thermoplastic resin, it is preferable to use one in the above melt flow rate range, and in the case of using multiple types of thermoplastic resin, one in the above melt flow rate range or the above melt flow It is preferable to mix ones out of the rate range and adjust within the above range. Among them, from the viewpoint of being more excellent in flowability and cleaning properties, when using a plurality of types of thermoplastic resins, it is preferable that the melt flow rates of all types of thermoplastic resins be within the above range.
The melt flow rate of the thermoplastic resin can be measured under the conditions of a temperature of 220 ° C. and a load of 10 kgf in accordance with ISO-R1133.

The content of the thermoplastic resin is 50 to 97 parts by mass with respect to the mass (100 parts by mass) of the detergent resin composition from the viewpoint of further improving the cleaning property while maintaining high fluidity. The amount is preferably 50 to 95 parts by mass, more preferably 60 to 94 parts by mass, still more preferably 70 to 93 parts by mass, and particularly preferably 75 to 92 parts by mass.

(Surfactant)
The above-mentioned surfactant does not decompose at the time of washing of the molding machine, and it is effective to melt at the melting temperature of the thermoplastic resin, and the decomposition start temperature of thermogravimetry (TGA) is 200 ° C. or more, and the melting point is It is necessary to be less than 100 ° C.
TGA refers to a measurement using Texa's TGA-DTA2500, using a gas flow of 20 ml / min and raising the temperature from room temperature to 550 ° C. at 10 ° C./min under air. The start point automatically displayed using analysis software (trade name “Proteus Analysis Ver. 6.1.0”, manufactured by Nech) was defined as the decomposition start temperature. When decomposition start temperature was not automatically displayed, the temperature at the top of exothermic absorption was manually selected and defined as decomposition start temperature.
The decomposition initiation temperature is preferably equal to or higher than the temperature at which the resin to be cleaned is molded, preferably 200 to 450 ° C., more preferably 220 to 450 ° C., and still more preferably 250 to 450 ° C.
The melting point can be measured by raising the temperature from room temperature to 250 ° C. at a rate of 20 ° C./minute under nitrogen using a DSC 3500 manufactured by Noche.
The temperature at the peak apex obtained at the first temperature elevation was taken as the melting point. The melting point is preferably equal to or lower than the melting temperature of the thermoplastic resin, and preferably 20 ° C. or more and less than 100 ° C.
As a thing which satisfy | fills the conditions of the said decomposition | disassembly start temperature and melting | fusing point, a sulfonate is preferable and alpha sulfo fatty-acid methyl ester salt is more preferable.

-Sulfonate-
Examples of the sulfonate include α-sulfofatty acid alkyl ester salts such as α-sulfofatty acid methyl ester salts, α-olefin sulfonates, alkane sulfonates and the like, and salts include potassium salts and sodium Salt etc. are mentioned.
Among them, α-sulfo fatty acid alkyl ester salts and α-olefin sulfonates are preferable. The fatty acid in the α-sulfofatty acid alkyl ester salt may be a fatty acid having 10 to 20 carbon atoms, and the alkyl may be an alkyl group having 1 to 20 carbon atoms, and the salt is a sodium salt Is preferred. The α-sulfo fatty acid alkyl ester salt is preferably an α-fatty acid methyl ester salt, more preferably 2-sulfohexadecanoic acid-1-methyl ester sodium salt or octadecanoic acid 2-sulfo-1-methyl ester sodium salt.
The carbon number of the olefin in the α-olefin sulfonate may be 1 to 30, 10 to 20, or 15 to 19. Also, the salt is preferably a sodium salt. As the above α-olefin sulfonate, sodium α-olefin sulfonate is preferable.
In particular, in the detergent resin composition of the present embodiment, a thermoplastic resin containing polyethylene and an α-sulfo fatty acid alkyl ester salt may be used in combination, from the viewpoint of obtaining particularly excellent cleaning properties and substitution properties. preferable.
The above-mentioned sulfonates can be used singly or in combination of two or more.

The detergent resin composition of the present embodiment preferably does not contain a linear alkyl benzene sulfonate from the viewpoint of detergency. The linear alkyl group in the linear alkyl benzene sulfonate may be an alkyl group having 1 to 20 (preferably 10 to 20) carbon atoms, and the salt may be a potassium salt or a sodium salt.

The content of the surfactant (in particular, the content of the sulfonate) is 1 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin, from the viewpoint of further improving the cleaning property and the substitution property. Is more preferably 2 to 10 parts by mass, still more preferably 3 to 8 parts by mass.

The content of the surfactant (in particular, the content of the sulfonate) is 0.5 to 20 parts by mass with respect to 100 parts by mass of the cleaning resin composition from the viewpoint of being further excellent in the cleaning property and the substitution property. Is more preferably 1 to 10 parts by mass, still more preferably 2 to 8 parts by mass.

(Phosphate, condensed phosphate)
It is preferable that the cleaning resin composition of the present embodiment further contain a phosphate and / or a condensed phosphate.
The above-mentioned phosphate may be sodium phosphate, preferably disodium hydrogen phosphate.
The above-mentioned condensed phosphate may be sodium condensed phosphate, and sodium pyrophosphate such as disodium dihydrogen pyrophosphate and sodium dihydrogen pyrophosphate; sodium tripolyphosphate; sodium tetrapolyphosphate; sodium pentapolyphosphate; metaphosphorous And the like, and at least one selected from the group consisting of sodium metaphosphate and sodium pyrophosphate is preferable, and sodium metaphosphate or sodium pyrophosphate is more preferable. Among them, sodium pyrophosphate is preferable, and disodium hydrogen pyrophosphate is more preferable, from the viewpoint of obtaining further excellent thermal stability.
When the detergent resin composition of the present embodiment contains a condensed phosphate (especially sodium pyrophosphate), it is more excellent in detergency and displaceability, and from the viewpoint of making it difficult for contaminants to adhere to the screw after cleaning, sulfone It is preferable to simultaneously use an acid salt (in particular, an α-sulfo fatty acid alkyl ester salt).
The said condensed phosphate can be used individually by 1 type, or in combination of 2 or more types.

The total content of the above-mentioned phosphate and the above-mentioned condensed phosphate is preferably 0.05 to 2 parts by mass with respect to 100 parts by mass of the above-mentioned thermoplastic resin, from the viewpoint of further improving the cleaning property and the substitution property. More preferably, it is 0.07 to 1.0 parts by mass, still more preferably 0.1 to 0.5 parts by mass.
Moreover, each content of the said phosphate or the said condensed phosphate is 0.05-2 mass parts with respect to 100 mass parts of said thermoplastic resins from a viewpoint which is more excellent in the washability and substitution property. Is more preferably 0.07 to 1.0 parts by mass, and still more preferably 0.1 to 0.5 parts by mass.

The total content of the above-mentioned phosphate and the above-mentioned condensed phosphate is 0.01 to 2 parts by mass with respect to 100 parts by mass of the detergent resin composition, from the viewpoint of further improving the cleaning property and the substitution property. The amount is preferably, more preferably 0.05 to 1.0 parts by mass, still more preferably 0.07 to 0.5 parts by mass.
Moreover, each content of the said phosphate or the said condensed phosphate is 0.01-2 mass parts with respect to 100 mass parts of detergent resin compositions from a viewpoint which is more excellent in washability and substitution property. Is more preferably 0.05 to 1.0 parts by mass, and still more preferably 0.07 to 0.5 parts by mass.

(Inorganic filler)
As the above-mentioned inorganic filler, any of natural products and artificial compounds can be used. Examples of the above-mentioned inorganic fillers include talc, mica, wollastonite, zonolite, kaolin clay, montmorillonite, bentonite, sepiolite, imogolite, sericite, rusonite, smectite, calcium carbonate, magnesium carbonate, titanium oxide, aluminum hydroxide, Examples thereof include, but are not limited to, magnesium hydroxide, zeolite, diatomaceous earth, glass powder, glass spheres, and shirasu balloon. In addition, these inorganic fillers can be used individually by 1 type or in combination of 2 or more types. The shape of these inorganic fillers is not particularly limited, and may be any shape (plate-like, needle-like, granular, fibrous, etc.). Further, these inorganic fillers may be calcined or those subjected to surface hydrophobic treatment with a silane coupling agent, a titanate coupling agent or the like.

(Additive)
Examples of the additives include flame retardants, anti-drip agents, dye pigments, heat stabilizers, ultraviolet light absorbers, fluorescent brightening agents, lubricants, processing aids, dispersants, mold release agents, thickeners, and antioxidants. Agents, antistatic agents, foaming agents and the like.

[Production method]
The method for producing the detergent resin composition of the present embodiment is not particularly limited. As a preferable production method, the thermoplastic resin, the surfactant, the above-mentioned phosphate compound blended as necessary, a condensed phosphate, an inorganic compound, an additive, a melt such as a kneader, an extruder or a Banbury mixer A manufacturing method comprising a step of melt-kneading using a kneading apparatus and extruding the obtained melt-kneaded product into a strand, and then forming into a pellet, the above thermoplastic resin, the above sulfonate, the above phosphate and / or Alternatively, the above-described condensed phosphate, the inorganic compound optionally mixed, and the additive are melt-kneaded using a melt-kneading apparatus such as a kneader, an extruder or a Banbury mixer, and the obtained melt-kneaded product is formed into strands After extrusion, the manufacturing method which has the process of shape | molding in a pellet form is mentioned.
The melt-kneading apparatus is preferably an extruder, more preferably a twin-screw extruder, from the viewpoint of being able to sufficiently knead the raw materials such as thermoplastic resin.
In blending and melt-kneading each component, generally used devices, for example, pre-mixing devices such as tumblers, ribbon blenders and super mixers, gravimetric feeders, single screw extruders, twin screw extruders, co-kneaders And the like can be used. In addition, when melt-kneading, open degassing to remove the degassing fraction from the open port (vent) under normal pressure, decompressing as necessary, and removing the degassing fraction from the open port (vent) It is desirable to

The cylinder temperature at the time of melt-kneading with an extruder is preferably set to 300 ° C. or less, more preferably 280 ° C. or less, still more preferably 260 ° C. or less, and particularly preferably 240 ° C. or less. Since it is desirable to make the residence time of the molten resin in the extruder as short as possible, the cylinder temperature is set in consideration of this point of view.

[Characteristic]
The melt flow rate (temperature 230 ° C., load 2.16 kgf) of the detergent resin composition of the present embodiment measured in accordance with ISO R 1133 is 1 to 30 g from the viewpoint of further improving fluidity, detergency, and substitution. It is preferably 10 minutes, more preferably 3 to 25 g / 10 minutes, still more preferably 5 to 20 g / 10 minutes.
In addition, the said melt flow rate can be measured by the method as described in the below-mentioned Example. The melt flow rate of the detergent resin composition can be adjusted according to the type and ratio of the raw materials contained in the composition.

The shape of the detergent resin composition of the present embodiment is preferably in the form of pellets. The size of the pellet is preferably in the form of a pellet having a diameter of 40 to 100% and a length of 40 to 100% with respect to the depth of the groove of the screw in the feed zone.

[how to use]
As a method of using the injection molding machine and the cleaning resin composition for a mold according to the present embodiment, an injection containing a thermoplastic resin and a surfactant having a TGA decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C. There is a method of cleaning a hot runner mold while melting a molding machine and a cleaning resin composition for a mold. The washing method can be performed by performing an injection operation or molding. In the cleaning method, the cleaning temperature of the cleaning agent resin composition is preferably in the range of 150 to 300 ° C.

The detergent resin composition of the present embodiment is suitable for use in cleaning an injection molding machine and a mold used for injection molding. In particular, the detergent resin composition of the present embodiment is excellent in the cleaning property and the substitution property in addition to the thermal stability, and therefore, under substantially the same conditions as the injection molding (for example, set temperature ± 20 ° C. at the injection molding) Even in the case of cleaning, the injection molding machine (in particular, the cylinder) and the mold used in the injection molding (in particular, the hot runner mold) can be cleaned efficiently and reliably.
Hot runner molds are difficult to clean, and there is a need to further improve the cleaning of hot runner parts and the replacement of cleaning agents. The cleaning agent resin composition of the present embodiment is excellent in cleaning ability and substitution, and is stable even at high temperature, so that the cleaning agent does not easily deteriorate even in a heated hot runner, and contamination of the cleaning agent hardly remains. Suitable for runner mold cleaners. The cleaning agent resin composition of the present embodiment is useful as a cleaning agent for a hot runner mold or the like having a long flow path (for example, a hot runner mold having a branch number of 2 or more, etc.).

EXAMPLES The present invention will be described in more detail based on examples given below, but the present invention is not limited by these examples.

Example 1
90 parts by mass of polypropylene (trade name: Sun Aroma PB270A, manufactured by Sun Aroma Co., Ltd.) as a thermoplastic resin (A), styrene-acrylonitrile resin (trade name: Styrac AS 783, Asahi Kasei Co., Ltd.) as a thermoplastic resin (B) 2 parts by mass, 1 part by mass of a fluorinated polymer (trade name: metabrene A 3000, manufactured by Mitsubishi Chemical Corporation) as a fluorine-based resin (C), and alpha sulfo fatty acid methyl ester sodium (trade name) as a surfactant : Mizuran P-80F, manufactured by Lion Specialty Chemicals Co., Ltd., TGA decomposition start temperature 296.4 ° C., melting point 59.4 ° C. 8 parts by mass, disodium hydrogen phosphate as phosphate (trade name: phosphoric acid) Hydrogen disodium, 0.2 parts by mass of Phosphorus Chemical Industry Co., Ltd., a twin screw extruder (PCM 30, Ikegai The mixture was kneaded under the conditions of 240.degree. C. and a pellet-like detergent resin composition was obtained. In addition, the obtained detergent resin composition was pale yellow.

(Example 2)
95 parts by mass of linear low density polyethylene (trade name: merit 4040F, manufactured by Ube Maruzen Polyethylene Co., Ltd.) as the thermoplastic resin (A), styrene-acrylonitrile resin (trade name: sty) as the thermoplastic resin (B) LAC AS 783, 2 parts by mass of Asahi Kasei Co., Ltd., 1 part by mass of a fluorinated polymer (trade name: METABRENE A 3000, manufactured by Mitsubishi Chemical Co., Ltd.) as a fluorocarbon resin (C), Alpha as a surfactant Sulfo fatty acid methyl ester sodium (trade name: Mizuran P-80F, manufactured by Lion Specialty Chemicals Co., Ltd.) 3 parts by mass, disodium hydrogen phosphate as a phosphate (trade name: disodium hydrogen phosphate, Phosphorus Chemical Industry ( Pellet-like detergent resin composition was prepared in the same manner as in Example 1 except that 0.5 parts by mass was used. Obtained. In addition, the obtained detergent resin composition was pale yellow.

(Example 3)
A pellet-like detergent resin composition was obtained in the same manner as in Example 1 except that the raw materials listed in Table 1 were used. Sodium α-olefin sulfonate (trade name: K Lipolane PJ-400CJ, manufactured by Lion Specialty Chemicals, Inc., TGA decomposition initiation temperature 210.5 ° C., melting point 96.8 ° C.) was used. Moreover, the obtained detergent resin composition was pale yellow.

(Example 4)
A pellet-like detergent resin composition was obtained in the same manner as in Example 1 except that the raw materials listed in Table 1 were used. As the condensed phosphate, 0.5 parts by mass of sodium pyrophosphate (trade name: sodium pyrophosphate, manufactured by Phosphorus Chemical Industry Co., Ltd.) was used. In addition, the obtained detergent resin composition was pale yellow.

(Comparative example 1)
A pellet-like detergent resin composition was obtained in the same manner as in Example 1 except that the raw materials listed in Table 1 were used. Sodium stearate (trade name: Na-St, manufactured by Nitto Kasei Kogyo Co., Ltd.) was used. Moreover, the obtained detergent resin composition was yellow.

(Comparative example 2)
Sodium dodecylbenzene sulfonate (reagent grade 1 sodium dodecyl benzene sulfonate, Kanto Chemical Co., Ltd. product, TGA decomposition initiation temperature 197.9 ° C., melting point 69.4 ° C.) was used as a surfactant.

(Comparative example 3)
As a surfactant, n-sodium dodecyl sulfate (reagent grade 1 n-sodium dodecyl sulfate, Kanto Chemical Co., Ltd., TGA decomposition initiation temperature 214.1 ° C., melting point 116.2 ° C.) was used.

[Evaluation]
The following measurement was performed about the cleaning agent resin composition obtained by the Example and the comparative example.

[Evaluation]
(Cleanability)
Black-colored polypropylene (Sun Aroma PM801 colored in black) is introduced into an injection molding machine (made by Meishin Seisakusho, clamping force: 100 tons) equipped with a hot runner mold, and the cylinder temperature is 220 ° C. Ten-shot molding was performed under injection conditions of a mold temperature of 40 ° C. Subsequently, the cylinder was retracted, and after all the black colored polypropylene was discharged from the cylinder, the cleaning resin composition obtained in the example or comparative example was put into an injection molding machine, and the cylinder was washed. The mass (g) of the detergent resin composition required until blackness disappeared was measured.
Subsequently, the hot runner mold was subjected to nozzle touch, and injection molding of the cleaning resin composition was performed under the same injection conditions as described above. Then, the number of shots (use amount per shot: 57 g / shot) required until blackness of the molded product disappeared was measured.

(Replaceability)
The cleaning agent resin composition obtained in the example or the comparative example is introduced into an injection molding machine (made by Meiki Seisakusho, mold clamping force: 100 tons) attached with a hot runner mold, cylinder temperature 220 ° C., mold After all the detergent resin composition is discharged from the injection molding machine under injection conditions of a temperature of 40 ° C., transparent polypropylene (trade name: Sun Aroma PM 802, manufactured by Sun Aroma Co., Ltd.) is introduced into the injection molding machine, and the inside of the cylinder is The mass (g) of the transparent polypropylene required to be replaced by the transparent polypropylene was measured.
Subsequently, the hot runner mold was attached again, and injection molding of transparent polypropylene was carried out under the same injection conditions as described above. Then, the number of shots (use amount per shot: 57 g / shot) required until no residue appeared on the molded product was measured.
In addition, the substitution to transparent polypropylene was confirmed by the fact that the residue derived from the detergent resin composition and the like is not visible in the discharge from the cylinder and the like.

(Melt flow rate)
The melt flow rate (g / 10 min) of the detergent resin composition obtained in Examples or Comparative Examples was measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kgf in accordance with ISO R1133.

(Total amount of resin etc.)
“The amount of cleaning composition required for cleaning the cylinder (g)” in the cleaning evaluation, “the number of shots required for cleaning the hot runner mold for cleaning evaluation (times) × 57 (weight of 1 shot of molded product g) ”,“ the amount of transparent PP required for cylinder replacement (g) ”in the evaluation of substitution, and“ the number of shots required for replacement of the hot runner mold in the evaluation of substitution (times) × 57 (molded articles) The total amount of "one shot weight (g))" was defined as the total amount of resin and the like used.

(Thermal stability)
The pellet of the cleaning resin composition obtained in the example or the comparative example is placed on an aluminum pan, and heated to 240 ° C. in a heat circulating dryer (trade name: air flow constant temperature incubator, manufactured by Yamato Scientific Co., Ltd.). The condition after leaving for 30 minutes was visually observed. As compared with before heating and leaving, those having a brown color were judged as poor (x), and those having almost no color were judged as good (o).

The injection molding machine and the cleaning resin composition for a mold according to the present embodiment are excellent in thermal stability, and also excellent in the cleaning property and the substitution property. Therefore, for use in cleaning the injection molding machine and the mold used for injection molding. Is suitable.

Claims (10)

An injection molding machine and a detergent resin composition for a mold, comprising a thermoplastic resin and a surfactant having a decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C. of TGA. The injection molding machine and the cleaner resin composition for a mold according to claim 1, wherein the surfactant is a sulfonate. The injection molding machine and the cleaner resin composition for a mold according to claim 1 or 2, wherein the surfactant is an alpha sulfo fatty acid methyl ester salt. The injection molding machine according to any one of claims 1 to 3, wherein the content of the surfactant is 1 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin. Resin composition. The resin composition for injection molding machine and mold according to any one of claims 1 to 4, further comprising a phosphate and / or a condensed phosphate. The injection molding machine and mold according to claim 5, wherein the phosphate is disodium hydrogen phosphate, and the condensed phosphate is at least one selected from the group consisting of sodium metaphosphate and sodium pyrophosphate. Cleaning resin composition. The injection molding machine and the mold according to claim 5 or 6, wherein a content of the phosphate or the condensed phosphate is 0.05 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic resin. Cleaning resin composition. The injection molding machine according to any one of claims 1 to 7, wherein the melt flow rate measured under the conditions of a temperature of 230 ° C and a load of 2.16 kgf according to ISO R1 133 is 1 to 30 g / 10 min. Mold cleaning resin composition. The injection molding machine and the cleaner resin composition for a mold according to any one of claims 1 to 8, wherein the thermoplastic resin contains an olefin resin. Cleaning a hot runner mold while melting a thermoplastic resin, an injection molding machine containing a surfactant having a decomposition start temperature of 200 ° C. or more and a melting point of less than 100 ° C. and a melting point less than 100 ° C. And a method of using the cleaning resin composition for injection molding machine and mold.