JPWO2019069798A1 - Detergent resin composition for injection molding machine and mold - Google Patents

Abstract

An object of the present invention is to provide a detergent resin composition for an injection molding machine and a die, which is excellent in thermal stability and is also excellent in cleanability and replaceability. The resin composition for injection molding machines and molds of the present invention is characterized by containing a thermoplastic resin and a surfactant having a TGA decomposition initiation temperature of 200°C or higher and a melting point of less than 100°C.

Description

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

  Generally, a resin molding machine such as an injection molding machine is used for operations such as resin molding. In this type of molding machine, at the end of a predetermined work, the resin used in the work, additives such as dyes and pigments, and residues of deteriorated raw materials (for example, thermal decomposition products and carbides) remain in the molding machine. Remain in. If these residues are left as they are, they may be mixed in during the work to be performed thereafter and cause a defective appearance of the obtained molded product. Therefore, it is desired to remove the residue from the molding machine almost completely.

  As a method of removing the residue from the inside of the molding machine, a method of introducing a cleaning agent into the molding machine to perform cleaning is implemented. As the cleaning agent, for example, a cleaning agent containing a thermoplastic resin is known (see Patent Documents 1 to 5).

JP, 9-208754, A JP, 2009-107160, A JP, 2013-154484, A JP, 2013-15521, A JP, 2014-077049, A

  From the viewpoint of work efficiency, it is desired that the cleaning of a molding machine using a cleaning agent be performed without significantly changing the conditions such as the temperature of the molding machine during cleaning from the molding conditions. However, conventional cleaning agents may discolor when washed at high temperature, and further improvement in thermal stability is required, and cleaning agents excellent in thermal stability, detergency and displaceability are required. Is currently required.

  Therefore, an object of the present invention is to provide a detergent resin composition for an injection molding machine and a die, which is excellent in thermal stability and is also excellent in cleanability and replaceability.

  That is, the present invention is as follows.

[1]
A cleaning resin composition for an injection molding machine and a mold, comprising a thermoplastic resin and a surfactant having a TGA decomposition initiation temperature of 200° C. or higher and a melting point of less than 100° C.

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

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

[4]
The cleaning agent for injection molding machines and molds 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 cleaning resin composition for an injection molding machine and a mold according to any one of [1] to [4], further containing 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 agent resin composition.

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

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

[10]
Cleaning the hot runner mold while melting the resin composition for injection molding machine and mold cleaner containing a thermoplastic resin and a surfactant having a TGA decomposition starting temperature of 200° C. or higher and a melting point of less than 100° C. An injection molding machine and a method for using a detergent resin composition for a die, comprising:

  According to the present invention, it is possible to provide a detergent resin composition for an injection molding machine and a mold, which has the above-mentioned constitution and is excellent in thermal stability and is also excellent in cleanability and replaceability.

  Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. It should be noted that the present invention is not limited to the following embodiments and can be variously modified and implemented within the scope of the gist thereof.

[Detergent resin composition]
The injection-molding machine and the cleaning agent resin composition for a mold of the present embodiment contain a thermoplastic resin and a surfactant having a TGA decomposition initiation temperature of 200° C. or higher and a melting point of less than 100° C.
Further, the injection molding machine and the detergent resin composition for a mold of the present embodiment preferably contain at least a thermoplastic resin, a sulfonate, and a phosphate and/or a condensed phosphate. 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 molds may be only called "cleaning agent resin composition."

(Thermoplastic resin)
Examples of the thermoplastic resin include polyethylene such as low density polyethylene (LDPE), high density polyethylene (HDPE) and linear low density polyethylene (LLDPE), olefins such as polypropylene (PP) and propylene-ethylene copolymer. Resin: polystyrene (PS), high-impact polystyrene (HIPS), acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), methylmethacrylate-butadiene-styrene resin (MBS resin), butyl acrylate-acrylonitrile -Styrene resin such as styrene resin (AAS resin); polyamide resin; polycarbonate; (meth)acrylic resin such as polymethylmethacrylate; polyester; polyarylate; polytetrafluoroethylene (Fluon PTFE fine powder CD097E manufactured by Asahi Glass Co., Ltd.) Etc.), a tetrafluoroethylene-ethylene copolymer, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, a fluororesin such as polytetrafluoroethylene mixed with an acrylic resin and a copolymer thereof; and the like. Among these, from the viewpoint of further improving the cleaning property and the substituting property, it is preferable to contain an olefin resin, more preferable to contain polyethylene and/or polypropylene, and particularly preferable to contain polyethylene.
Here, the olefin-based resin and the styrene-based resin refer to a resin in which the content of a structural unit derived from an olefin or a styrene-based monomer is 50% by mass or more based on the total mass of the resin.
The thermoplastic resins may be used alone or in combination of two or more. When two or more kinds of thermoplastic resins are used in combination, two or more kinds of thermoplastic resins having different structures can be used in combination, and two or more kinds of thermoplastic resins having different molecular weights are used in combination. You can also do it.

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 are used because they are more excellent in detergency and displaceability. It is preferable to include a resin (C). When a copolymer containing ethylene such as ethylene-ethyl acrylate (EEA), ethylene-methacrylate (EMA), ethylene-methyl methacrylate (EMMA) and ethylene-butyl acrylate (EBA) as a structural unit is contained, the copolymerization This is not preferable because the coalesce easily adheres to the metal and remains. In particular, it is not preferable to use the copolymer and the fluororesin (C) in combination, because it becomes difficult to obtain the effect of adding the fluororesin (C).
The thermoplastic resin (A), the thermoplastic resin (B), and the fluororesin (C) may be used alone or in combination of two or more.

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 methacrylic ester resin and an olefin resin, a combination of a polycarbonate and an olefin resin. Examples of the combination include a combination of an olefin-based resin and a styrene-based resin, among which a combination of PE and PS, a combination of PP and PS, a combination of PE and AS resin are preferable from the viewpoint of more excellent cleaning properties and substitution properties. And a combination of PP and an AS resin are more preferable, and a combination of PE and an AS resin and a combination of PP and an AS resin are preferable from the viewpoint of obtaining particularly remarkable effects of detergency and displaceability.
As the mixing ratio of the thermoplastic resin (A) and the thermoplastic resin (B), from the viewpoint of further improving the cleaning property and the substituting property, the mass of the thermoplastic resin (B) relative to 100 parts by mass of the thermoplastic resin (A). The proportion is preferably 0.5 to 30 parts by mass, and more preferably 1 to 10 parts by mass from the viewpoint that residual in the molding machine after cleaning is further reduced.

Examples of the fluorine-based resin (C) include the above-mentioned fluorine-based resins. Among them, from the viewpoint of further improving the cleaning property and the substituting property, and suppressing the generation of fine powder in the cleaning resin composition. Polytetrafluoroethylene mixed with acrylic resin is preferable.
The content of the fluororesin (C) is 0. 0 from the total mass (100 parts by mass) of the thermoplastic resin (A) and the thermoplastic resin (B) from the viewpoint of the balance between the cleaning property and the displaceability. 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 minutes, more preferably 15 to 150 g/10 minutes, from the viewpoint of further improving the fluidity and detergency of the detergent resin composition. It is more preferably 20 to 100 g/10 minutes, particularly preferably 25 to 70 g/10 minutes, and most preferably 25 to 60 g/10 minutes.
Here, the melt flow rate of the thermoplastic resin means the arithmetic mean (arithmetic mean) of all the thermoplastic resins contained in the detergent resin composition of the present embodiment. Therefore, when one kind of thermoplastic resin is used, it is preferable to use one having the above melt flow rate range, and when using plural kinds of thermoplastic resins, one having the above melt flow rate range or the above melt flow rate is used. It is preferable to adjust the content within the above range by mixing those outside the rate range. Among them, when a plurality of types of thermoplastic resins are used, the melt flow rate of all types of thermoplastic resins is preferably within the above range from the viewpoint of more excellent fluidity and washability.
The melt flow rate of the thermoplastic resin can be measured according to ISO-R1133 under the conditions of a temperature of 220°C and a load of 10 kgf.

  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. It is preferably 50 to 95 parts by mass, more preferably 60 to 94 parts by mass, further preferably 70 to 93 parts by mass, and particularly preferably 75 to 92 parts by mass.

(Surfactant)
Since it is effective that the above-mentioned surfactant does not decompose during washing of the molding machine and that it melts at the melting temperature of the thermoplastic resin, the decomposition start temperature of thermogravimetric analysis (TGA) is 200° C. or higher and the melting point is It needs to be lower than 100°C.
TGA means a measurement using TGA-DTA2500 manufactured by Netche, 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 starting point automatically displayed using the analysis software (trade name "Proteus Analysis Ver. 6.1.0", manufactured by Netche) was defined as the decomposition start temperature. When the decomposition start temperature was not automatically displayed, the temperature at the peak of exothermic absorption was manually selected and defined as the decomposition start temperature.
The decomposition initiation temperature is preferably not lower than the temperature at which the resin to be washed is molded, preferably 200 to 450°C, more preferably 220 to 450°C, and further preferably 250 to 450°C.
The melting point can be measured by using DSC3500 manufactured by Netche Co., Ltd. under nitrogen and elevating the temperature from room temperature to 250° C. at 20° C./min.
The temperature at the peak apex obtained by the first temperature rise was taken as the melting point. The melting point is preferably equal to or lower than the melting temperature of the thermoplastic resin, and is preferably 20° C. or higher and lower than 100° C.
Sulfonates are preferable, and alpha sulfo fatty acid methyl ester salts are more preferable, as those satisfying the conditions of the decomposition starting temperature and the melting point.

-Sulfonate-
Examples of the sulfonate include α-sulfofatty acid alkyl ester salts such as α-sulfofatty acid methyl ester salt, α-olefin sulfonate, alkane sulfonate, and the like. Examples of the salt include potassium salt and sodium salt. Salt etc. are mentioned.
Of these, α-sulfo fatty acid alkyl ester salt and α-olefin sulfonate are preferable. The fatty acid in the α-sulfo fatty acid alkyl ester salt may be a fatty acid having 10 to 20 carbon atoms, the alkyl may be an alkyl group having 1 to 20 carbon atoms, and the salt is a sodium salt. Preferably. The α-sulfo fatty acid alkyl ester salt is preferably an α-fatty acid methyl ester salt, and more preferably 2-sulfohexadecanoic acid-1-methyl ester sodium salt and octadecanoic acid 2-sulfo-1-methyl ester sodium salt.
The number of carbon atoms of the olefin in the α-olefin sulfonate may be 1 to 30, 10 to 20, or 15 to 19. Further, the salt is preferably a sodium salt. As the α-olefin sulfonate, sodium α-olefin sulfonate is preferable.
In particular, in the detergent resin composition of the present embodiment, it is preferable to use a thermoplastic resin containing polyethylene and an α-sulfofatty acid alkyl ester salt in combination, from the viewpoint of obtaining particularly excellent detergency and replaceability. preferable.
The sulfonates may be used alone or in combination of two or more.

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

  The content of the surfactant (particularly, 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 excellent cleaning properties and replaceability. Is preferable, more preferably 2 to 10 parts by mass, further preferably 3 to 8 parts by mass.

  The content of the surfactant (particularly, the content of the sulfonate) is 0.5 to 20 parts by mass with respect to 100 parts by mass of the detergent resin composition, from the viewpoint of more excellent detergency and displaceability. Is more preferable, 1 to 10 parts by mass is more preferable, and 2 to 8 parts by mass is still more preferable.

(Phosphate, condensed phosphate)
The cleaning resin composition of the present embodiment preferably further contains a phosphate and/or a condensed phosphate.
The phosphate may be sodium phosphate, preferably disodium hydrogen phosphate.
The above-mentioned condensed phosphate may be condensed sodium phosphate, such as sodium pyrophosphate such as disodium dihydrogen pyrophosphate and sodium dihydrogen pyrophosphate; sodium tripolyphosphate; sodium tetrapolyphosphate; sodium pentapolyphosphate; metaline. 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. Of these, 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 (particularly sodium pyrophosphate), it is more excellent in detergency and displaceability, and in addition, contaminants hardly adhere to the screw after washing. It is preferable to use an acid salt (particularly, α-sulfofatty acid alkyl ester salt) at the same time.
The above-mentioned condensed phosphates may be used alone or in combination of two or more.

The total content of the phosphate salt and the condensed phosphate salt is preferably 0.05 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic resin, from the viewpoint of further excellent cleaning properties and replaceability. , More preferably 0.07 to 1.0 part by mass, further preferably 0.1 to 0.5 part by mass.
Further, the content of each 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, from the viewpoint of more excellent detergency and replaceability. Is more preferable, more preferably 0.07 to 1.0 part by mass, still more preferably 0.1 to 0.5 part by mass.

The total content of the phosphate and the 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 excellent cleaning properties and substituting properties. The amount is preferably 0.05 to 1.0 part by mass, more preferably 0.07 to 0.5 part by mass.
Further, the content of each of the phosphate or the 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 excellent detergency and replaceability. The amount is preferably 0.05 to 1.0 part by mass, more preferably 0.07 to 0.5 part by mass.

(Inorganic filler)
As the inorganic filler, both natural products and artificial synthetic products can be used. Examples of the inorganic filler include talc, mica, wollastonite, xonotlite, kaolin clay, montmorillonite, bentonite, sepiolite, imogolite, sericite, lawsonite, smectite, calcium carbonate, magnesium carbonate, titanium oxide, aluminum hydroxide, Examples thereof include magnesium hydroxide, zeolite, diatomaceous earth, glass powder, glass spheres, and shirasu balloons, but are not particularly limited thereto. 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 ones, 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-dripping agents, dyes and pigments, heat stabilizers, ultraviolet absorbers, optical brighteners, lubricants, processing aids, dispersants, release agents, thickeners, and antioxidants. Agents, antistatic agents, foaming agents and the like.

[Production method]
The method for producing the detergent resin composition of this embodiment is not particularly limited. As a preferred production method, the thermoplastic resin, the surfactant, the phosphate, condensed phosphate, inorganic compound, and additives that are blended as necessary are melted in a kneader, an extruder, a Banbury mixer, or the like. Melt-kneading using a kneading device, after extruding the resulting melt-kneaded product into a strand shape, a manufacturing method having a step of molding into a pellet, the thermoplastic resin, the sulfonate, the phosphate and / Alternatively, the above-mentioned condensed phosphate, an inorganic compound to be blended if necessary, and an additive are melt-kneaded using a melt-kneading device such as a kneader, an extruder or a Banbury mixer, and the obtained melt-kneaded product is formed into a strand. A manufacturing method including a step of molding into pellets after extrusion is mentioned.
As the melt-kneading device, an extruder is preferable, and a twin-screw extruder is more preferable, from the viewpoint that raw materials such as a thermoplastic resin can be sufficiently kneaded.
At the time of blending and melt-kneading the respective components, generally used equipment, for example, a tumbler, a ribbon blender, a premixing equipment such as a super mixer, a gravimetric feeder, a single-screw extruder or a twin-screw extruder, a co-kneader. And the like can be used. Also, when melt-kneading, open devolatilization that removes the devolatilized components from the open port (vent) under normal pressure, and reduced pressure devolatilization that depressurizes as necessary to remove the devolatilized components from the open port (vent) Is desirable.

  The cylinder temperature at the time of melt-kneading with an extruder is preferably set to 300° C. or lower, more preferably 280° C. or lower, further preferably 260° C. or lower, particularly preferably 240° C. or lower. Since it is desirable that the residence time of the molten resin in the extruder be as short as possible, the cylinder temperature is set in consideration of this viewpoint.

[Characteristic]
The melt flow rate (temperature 230° C., load 2.16 kgf) measured according to ISO R1133 of the detergent resin composition of the present embodiment is 1 to 30 g from the viewpoint of further excellent fluidity, detergency and displaceability. It is preferably /10 minutes, more preferably 3 to 25 g/10 minutes, still more preferably 5 to 20 g/10 minutes.
The melt flow rate can be measured by the method described in Examples below. The melt flow rate of the detergent resin composition can be adjusted by the kind and ratio of the raw materials contained in the composition.

  The detergent resin composition of the present embodiment preferably has a pellet shape. The size of the pellet is preferably 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]
The method of using the injection-molding machine and the mold-detergent resin composition according to the present embodiment includes injection including a thermoplastic resin and a surfactant having a TGA decomposition initiation temperature of 200° C. or higher and a melting point of less than 100° C. A method of cleaning the hot runner mold while melting the resin composition of the molding machine and the mold cleaner can be used. The cleaning method can be performed by performing an injection operation or molding. In the cleaning method, the cleaning temperature of the cleaning 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 detergency and replaceability in addition to thermal stability, and therefore, under substantially the same conditions as those during injection molding (for example, the set temperature during injection molding ±20° C.). Even when cleaning is performed, the injection molding machine (especially the cylinder) and the mold used for the injection molding (especially the hot runner mold) can be cleaned efficiently and surely.
It is difficult to clean the hot runner mold, and it is required to further improve the cleaning of the hot runner part and the replacement of the cleaning agent. The detergent resin composition of the present embodiment is excellent in detergency and displaceability, and the detergency of the detergency of the detergency of the detergency of the detergency of the detergency of the detergency of the detergency of the detergency is low. Suitable for cleaning runner molds. The detergent resin composition of the present embodiment is useful as a detergent for a hot runner die having a long flow path (for example, a hot runner die having a branch number of 2 or more).

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Example 1)
90 parts by mass of polypropylene (trade name: San Allomer PB270A, manufactured by San Allomer Co., Ltd.) as the thermoplastic resin (A), and styrene-acrylonitrile-based resin (trade name: Styrac AS783, Asahi Kasei Co., Ltd.) as the thermoplastic resin (B). 2 parts by mass, 1 part by mass of a fluorinated polymer (trade name: Metabrene A3000, manufactured by Mitsubishi Chemical Co., Ltd.) as a fluororesin (C), and alpha sulfo fatty acid methyl ester sodium (trade name) as a surfactant. : Mizulan P-80F, manufactured by Lion Specialty Chemicals Co., Ltd., 8 parts by mass of TGA decomposition start temperature 296.4°C, melting point 59.4°C, disodium hydrogen phosphate as a phosphate (trade name: phosphoric acid) 0.2 parts by mass of disodium hydrogen, manufactured by Rin Kagaku Kogyo Co., Ltd. was kneaded using a twin-screw extruder (PCM30, manufactured by Ikegai Co., Ltd.) under the condition of 240° C., and pelletized detergent resin A composition was obtained. The obtained detergent resin composition was pale yellow.

(Example 2)
95 parts by mass of linear low-density polyethylene (trade name: Yumerit 4040F, manufactured by Ube Maruzen Polyethylene Co., Ltd.) as the thermoplastic resin (A), and styrene-acrylonitrile-based resin (trade name: Stai) as the thermoplastic resin (B). Rack AS 783, Asahi Kasei Co., Ltd. 2 parts by mass, Fluoropolymer (trade name: Metablen A3000, Mitsubishi Chemical Co., Ltd.) 1 part by mass as a fluororesin (C), and alpha as a surfactant. 3 parts by mass of sodium sulfofatty acid methyl ester (trade name: Mizulan P-80F, manufactured by Lion Specialty Chemicals Co., Ltd.), disodium hydrogen phosphate as a phosphate (trade name: disodium hydrogen phosphate, Phosphorous Chemical Industry ( A pellet-shaped detergent resin composition was obtained in the same manner as in Example 1 except that 0.5 part by mass of Co., Ltd.) was used. The obtained detergent resin composition was pale yellow.

(Example 3)
A detergent resin composition in the form of pellets was obtained in the same manner as in Example 1 except that the raw materials shown in Table 1 were used. Sodium α-olefin sulfonate (trade name: K Liporan PJ-400CJ, manufactured by Lion Specialty Chemicals Co., Ltd., TGA decomposition start temperature 210.5° C., melting point 96.8° C.) was used. Further, the obtained detergent resin composition was pale yellow.

(Example 4)
A detergent resin composition in the form of pellets was obtained in the same manner as in Example 1 except that the raw materials shown in Table 1 were used. As the condensed phosphate, 0.5 part by mass of sodium pyrophosphate (trade name: sodium pyrophosphate, manufactured by Rin Kagaku Kogyo Co., Ltd.) was used. The obtained detergent resin composition was pale yellow.

(Comparative Example 1)
A detergent resin composition in the form of pellets was obtained in the same manner as in Example 1 except that the raw materials shown in Table 1 were used. In addition, sodium stearate (trade name: Na-St, manufactured by Nitto Kasei Kogyo Co., Ltd.) was used. The obtained detergent resin composition was yellow.

(Comparative example 2)
Sodium dodecylbenzene sulfonate (reagent deer grade 1 sodium dodecylbenzene sulfonate, manufactured by Kanto Chemical Co., Inc., TGA decomposition starting temperature 197.9°C, melting point 69.4°C) was used as a surfactant.

(Comparative example 3)
As a surfactant, sodium n-dodecyl sulfate (reagent deer first grade n-dodecyl sodium sulfate, manufactured by Kanto Chemical Co., Inc., TGA decomposition starting temperature 214.1°C, melting point 116.2°C) was used.

[Evaluation]
The following measurements were performed on the detergent resin compositions obtained in the examples and comparative examples.

[Evaluation]
(Washability)
A polypropylene colored in black (Sun Allomer PM801 colored in black) was put into an injection molding machine (manufactured by Meiki Seisakusho, mold clamping force: 100 tons) equipped with a hot runner mold, and a cylinder temperature was 220°C. Ten shot molding was carried out under the injection condition 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 detergent resin composition obtained in each of Examples and Comparative Examples was put into an injection molding machine to wash the cylinder. The mass (g) of the detergent resin composition required until the black color disappeared was measured.
Subsequently, the hot runner mold was brought into nozzle contact, and injection molding of the detergent resin composition was carried out under the same injection conditions as above. Then, the number of shots required until the black color disappeared in the molded product (use amount per shot: 57 g/shot) was measured.

(Replaceability)
An injection molding machine (manufactured by Meiki Seisakusho, mold clamping force: 100 tons) equipped with a hot runner mold was charged with the detergent resin composition obtained in the examples or comparative examples, and the cylinder temperature was 220° C. and the mold was formed. After the cleaning resin composition was completely discharged from the injection molding machine under the injection condition of a temperature of 40° C., transparent polypropylene (trade name: Sun Allomer PM802, manufactured by Sun Allomer Co., Ltd.) was put into the injection molding machine, and the inside of the cylinder was The mass (g) of the transparent polypropylene required until it was replaced with the transparent polypropylene was measured.
Subsequently, the hot runner mold was attached again, and transparent polypropylene was injection-molded under the same injection conditions as above. Then, the number of shots required until the residue was no longer visible in the molded product (use amount per shot: 57 g/shot) was measured.
The replacement with transparent polypropylene was confirmed by the fact that the residue derived from the detergent resin composition and the like could not be seen in the discharge from the cylinder.

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

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

(Thermal stability)
The pellets of the detergent resin composition obtained in Examples or Comparative Examples are placed on an aluminum dish, and 240° C. in a heat-circulation dryer (trade name: blast constant temperature oven, manufactured by Yamato Scientific Co., Ltd.). After being left to stand for 30 minutes, the state was visually observed. Compared with those before heating and leaving, those with a brown discoloration were judged to be poor (x), and those with almost no discoloration were judged to be good (∘).

  The injection-molding machine and the mold cleaner resin composition of the present embodiment are excellent in thermal stability, and also excellent in cleanability and displaceability, and therefore are suitable for use in cleaning the injection-molding machine and the mold used for injection molding. Are suitable.

Claims (10)

  A cleaning resin composition for an injection molding machine and a mold, comprising a thermoplastic resin and a surfactant having a TGA decomposition initiation temperature of 200° C. or higher and a melting point of less than 100° C.   The cleaning resin composition for an injection molding machine and a mold according to claim 1, wherein the surfactant is a sulfonate.   The cleaning agent resin composition for an injection molding machine and a mold according to claim 1 or 2, wherein the surfactant is an alpha sulfo fatty acid methyl ester salt.   The cleaning agent for an injection molding machine and a mold 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 cleaning resin composition for an injection molding machine and a mold according to any one of claims 1 to 4, further comprising a phosphate and/or a condensed phosphate.   The injection molding machine and the 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 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. 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 R1133 is 1 to 30 g/10 minutes. Mold cleaning agent resin composition.   The cleaning resin composition for an injection molding machine and a mold according to any one of claims 1 to 8, wherein the thermoplastic resin contains an olefin resin.   Cleaning the hot runner mold while melting the resin composition for injection molding machine and mold cleaner containing a thermoplastic resin and a surfactant having a TGA decomposition starting temperature of 200° C. or higher and a melting point of less than 100° C. An injection molding machine and a method of using a detergent resin composition for a die, comprising: