TWI588160B - Foaming polystyrene resin particle and manufacturing method thereof, pre-foamed particle and foamed molded article - Google Patents

Description

Expandable polystyrene resin particle, method for producing the same, pre-expanded particle and foam molded body

The invention relates to an excellent strength and impact resistance The expandable polystyrene resin particles of the foamed molded article having a uniform color and a uniform appearance, and a method for producing the same, and a polystyrene resin preliminary expanded particle and a polystyrene resin foam molded article. The foam molding system of the present invention can be used in various fields such as a cushion material such as a helmet core material and an automobile interior material, various containers, and construction materials.

The polystyrene resin foam molded body is heated by steam or the like The medium heats the foamable polystyrene resin particles containing the physical foaming agent. After foaming to prepare preliminary foamed particles, the preliminary expanded particles are filled in a cavity of a molding die, and then a heating medium such as steam is pressed into a molding die to heat, foam, and fill the preliminary foamed particles. The gap between the buried foamed particles is fused and integrated by the foaming pressure, and then produced by a cooling step of cooling the obtained foamed molded body in a mold.

Polystyrene-based resin foam molded body (hereinafter referred to as a foam molded body) It is excellent in light weight, high strength, and excellent in punching resistance and heat insulation. It is used in various applications such as cushioning materials such as helmet core materials and automotive interior materials, various containers, and construction materials. Previously, regarding the coloring and performance of the foamed molded article, for example, the techniques disclosed in the patent documents 1 to 3 are proposed.

Patent Document 1 discloses that a colored styrene resin is foamed into The shape is obtained by heating and melting a resin composition containing a styrene resin, a colorant, and a foaming agent in an extruder, and cooling, cutting, and pelletizing the melt. A styrene-based resin foam molded article obtained by in-mold foam molding, wherein the surface of the molded body is image-processed by using an image processing apparatus with 256 gray scales. When the brightness is measured, the average brightness value is set to a threshold value, and the threshold value is set to a rich color side brightness value, and when the threshold value is set to a light color side brightness value, a brightness difference is obtained. (The light side average brightness value - the rich side side average brightness value) has a value of 70 or less.

Patent Document 2 discloses a preliminary foamed resin particle having a surface The wax-coated or impregnated preliminary foamed resin particles are characterized in that the wax is from 1% by mass to 30% by mass based on the preliminary foamed resin particles. It is described that the foamed resin molded body obtained by hot-melting the preliminary foamed resin particles as a raw material has a small amount of frictional sound and is suitable as a base material for automotive flooring.

Patent Document 3 discloses a foamable polystyrene resin particle, The polystyrene-based resin containing a foaming agent is formed into a granular shape, and the polystyrene-based resin has a mass average molecular weight Mw of from 120,000 to 270,000. The foaming agent is an essential component, and contains pentane in a ratio of 3 to 8 parts by mass with respect to 100 parts by mass of the polystyrene-based resin, and the pentane described above The composition is in the range of isopentane: n-pentane = 10:90 to 80:20 by mass ratio.

Prior technical literature Patent literature

[Patent Document 1] JP-A-7-132527

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2005-187715

[Patent Document 3] Japanese Laid-Open Patent Publication No. WO2009/096341

However, the foamed molded body obtained by the prior art disclosed in Patent Documents 1 to 3 is insufficient in strength and impact resistance, and there is still a need for improvement.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a foamable polystyrene resin particle which is excellent in strength and impact resistance, uniform in coloration, and excellent in appearance, and a method for producing the same, and a method for producing the same The pre-expanded particles and the foamed molded article obtained from the expandable polystyrene resin particles.

In order to achieve the above-mentioned problem, the present invention provides a foamable polystyrene resin particle containing a physical foaming agent, a coloring agent, and a polystyrene resin, and is colored with respect to 100 parts by mass of a polystyrene resin. The agent is contained in an amount of from 0.3 to 9.0 parts by mass, and the average cell diameter in the foamed molded article obtained by foam molding in a range of from 0.055 to 0.125 g/cm ³ is from 50 to 300 μm, and the foamed molded body is contained. The impulse acceleration G value is 300G or less.

Furthermore, the present invention provides a foamable polystyrene resin particle comprising a physical foaming agent, a coloring agent, and a polystyrene resin, and the coloring agent is contained in an amount of 100 parts by mass of the polystyrene resin. The foamed molded article obtained by foam molding in a range of from 0.35 to 0.125 g/cm ^{3 in} an amount of from 0.3 to 9.0 parts by mass has a brightness of from 20 to 95.

In the foamable polystyrene resin particles of the present invention, one or both of a coloring agent, an inorganic foaming nucleating agent, and a chemical foaming agent are preferably foamed polystyrene resin particles as a whole (but It is evenly contained in the internal bubble system.

In the foamable polystyrene resin particles of the present invention, the coloring agent is preferably one or more selected from the group consisting of inorganic pigments and organic pigments.

In the expandable polystyrene resin particles of the present invention, it is preferred that the polystyrene resin has a melt flow rate (MFR) measured at 200 ° C of 1.0 to 10.0 g/10 min and is measured at 200 ° C. The melt tension (MT) is 5 cN or more.

In the expandable polystyrene resin particles of the present invention, the methanol soluble fraction of the above polystyrene resin is preferably in the range of 0.1 to 5.0% by mass.

The expandable polystyrene resin particles of the present invention are preferably produced by a melt extrusion method in which a foaming agent is pressed into a polystyrene which has been melted in a resin supply device. The resin is kneaded, and the molten resin containing the foaming agent is directly extruded from the small hole of the mold attached to the front end of the resin supply device into the cooling liquid, and the extruded liquid is extruded into the cooling liquid. The discharge is cut in a cooling liquid using a rotary blade while being cooled and solidified by bringing the extrudate into contact with the liquid.

Moreover, the present invention provides a method for producing expandable polystyrene resin particles which are produced by a melt extrusion method; the melt extrusion method is a physical foaming agent The resin is pressed into a polystyrene-based resin containing a coloring agent in a resin supply device and kneaded, and the molten resin containing the foaming agent is directly injected from a small hole of a mold attached to the front end of the resin supply device. Extrusion into the cooling liquid, and the extrudate extruded into the cooling liquid is cut in a cooling liquid using a rotary blade, and the foam is cooled and solidified by bringing the extrudate into contact with the liquid to obtain the foam. The polystyrene-based resin particles are obtained, and the foamable polystyrene-based resin particles are added in an amount of 0.3 to 9.0 parts by mass based on 100 parts by mass of the polystyrene-based resin, and have a density of 0.055 to 0.125 g. The foamed molded article obtained by foam molding in the range of /cm ³ has an average cell diameter of 50 to 300 μm, and the foamed molded article has a punching acceleration G value of 300 G or less.

In the method for producing the expandable polystyrene resin particles of the present invention, it is preferred to obtain a foam molded article having a density of from 0.055 to 0.125 g/cm ³ and having a brightness of 20 to 95. Expandable polystyrene resin particles.

In the production of the expandable polystyrene resin particles of the present invention Preferably, one or both of an inorganic foaming nucleating agent and a chemical foaming agent are further added to the polystyrene resin, and one of a coloring agent, an inorganic foaming nucleating agent, and a chemical foaming agent is obtained. Both of the foamable polystyrene resin particles are uniformly contained in the entire foamable polystyrene resin particles (except for the internal bubble system).

In the production of the expandable polystyrene resin particles of the present invention In the method, it is preferred that the coloring agent is one or more selected from the group consisting of inorganic pigments and organic pigments.

In the production of the expandable polystyrene resin particles of the present invention Preferably, the polystyrene resin is a melt flow rate (MFR) measured at 200 ° C in a range of 1.0 to 10.0 g/10 min, and a melt tension (MT) measured at 200 ° C. It is 5cN or more.

In the production of the expandable polystyrene resin particles of the present invention In the method, it is preferred that the methanol-soluble content of the polystyrene-based resin is in the range of 0.1 to 5.0% by mass.

Moreover, the present invention provides a preliminary expanded particle which is foamed as described above. The obtained polystyrene-based resin particles are heated and foamed.

Moreover, the present invention provides a foam molded body which is prepared as described above. The foamed particles are filled in a cavity of a molding die, and are obtained by heating in-mold foam molding.

Furthermore, the present invention provides a foamed molded article obtained by foam molding a foamable polystyrene resin particle containing a physical foaming agent, a coloring agent, and a polystyrene resin, with respect to 100 parts by mass. The polystyrene-based resin contains 0.3 to 9.0 parts by mass of the colorant, and has an average cell diameter of 50 to 300 μm in a range of density of 0.055 to 0.125 g/cm ³ and a G acceleration of 300 G or less.

In the foamed molded article of the present invention, preferably, the coloring agent is selected from no One or more of the group consisting of organic pigments and organic pigments.

The foam molding system of the present invention is suitable as a helmet core material or a car For interior decoration.

In the expandable polystyrene resin particles of the present invention, the polystyrene-based resin containing the physical foaming agent and the coloring agent is formed into a granular form, and the coloring agent is contained in 0.3 part by mass of the polystyrene-based resin. 9.0 parts by mass, the average cell diameter in the foam molded article obtained by foam molding in a range of 0.055 to 0.125 g/cm ^{3 is} in the range of 50 to 300 μm, and the ramification acceleration of the foamed molded article Since the G value is 300 G or less, or the brightness is in the range of 20 to 95, the pre-expanded particles obtained by heating the resin particles and performing preliminary foaming are subjected to in-mold expansion molding, and excellent strength and impact resistance are obtained. Foamed molded body.

Further, it is possible to obtain a foam molded article having a uniform coloration and good appearance.

The method for producing the expandable polystyrene resin particles of the present invention is such that, in the method for producing expandable polystyrene resin particles by the melt extrusion method, coloring is obtained with respect to 100 parts by mass of the polystyrene resin. 0.3 to 9.0 parts by mass of the agent, and the average cell diameter in the foamed molded article obtained by foam molding in a range of a density of 0.055 to 0.125 g/cm ^{3 is} in the range of 50 to 300 μm, and the foamed molded article Since the foaming polystyrene-based resin particles having a G value of 300 G or less are used, it is possible to efficiently produce a foamable polyphenylene having a foam molded article which is excellent in strength and impact resistance and has a good coloration and good appearance. Ethylene resin particles.

In the foamed molded article of the present invention, the foamable polystyrene resin particles containing the coloring agent are obtained by foam molding, and the coloring agent is contained in an amount of 0.3 to 9.0 parts by mass based on 100 parts by mass of the polystyrene resin. In the range of the density of 0.055 to 0.125 g/cm ³ , the average cell diameter is in the range of 50 to 300 μm, and the punching acceleration G value is 300 G or less, so that the strength and the impact resistance are excellent, and the appearance of uniform coloration is good. The foam molding system of the present invention is suitable as a cushioning material such as a helmet core material or an automobile interior decoration material.

1‧‧‧Extrusion machine (resin supply unit)

2‧‧‧Molding

3‧‧‧Material supply hopper

4‧‧‧High pressure pump

5‧‧‧Blowing agent supply port

6‧‧‧Cutter

7‧‧‧ cutting room

8‧‧‧Sink

9‧‧‧High pressure pump

10‧‧‧Dehydration dryer with solid-liquid separation function

11‧‧‧ storage container

Fig. 1 is a configuration diagram showing an example of a manufacturing apparatus of expandable polystyrene resin particles by a melt extrusion method.

(foaming polystyrene resin particles)

The expandable polystyrene resin particle of the present invention contains a physical foaming agent, a coloring agent, and a polystyrene resin, and contains 0.3 to 9.0 parts by mass of the coloring agent per 100 parts by mass of the polystyrene resin. And the average cell diameter in the foamed molded article obtained by foam molding in a range of a density of 0.055 to 0.125 g/cm ^{3 is} in the range of 50 to 300 μm, and the punching acceleration G value of the foamed molded article is 300 G. Hereinafter, the brightness is in the range of 20 to 95.

Melt flow rate (MFR) measured at 200 ° C of the above polystyrene resin It is preferably in the range of 1.0 to 10.0 g/10 minutes, and preferably in the range of 1.2 to 8.0 g/10 minutes. When the MFR of the polystyrene-based resin is less than 1.0 g/10 minutes, the foaming ratio of the foam obtained by heating the expandable polystyrene-based resin particles may not be increased, and is greater than 10.0 g/10. In the minute, the strength and the flushing resistance of the foam obtained by heating the expandable polystyrene resin particles are lowered.

<Method for Measuring Melt Flow Rate (MFR)>

In the present invention, the melt flow rate is based on the test method of the melt mass-flow rate (MFR) and the melt volume-flow rate (MVR) of the plastic-thermoplastic plastic according to JIS K 7210:1999. The value measured by the method described in the B method.

Specifically, for example, a measuring device commercially available from Toyo Seiki Seisakusho Co., Ltd. under the trade name "SEMI-AUTO MELT INDEXER" is used, and 3 to 8 g of the sample is filled in a cylinder of the measuring device, and the sample is compressed using a filling rod. The melt flow rate of the polystyrene resin was measured under the measurement conditions of a test temperature of 200 ° C, a load of 49.03 N, and a preheating time of 4 minutes. Moreover, the number of tests is set to three or more. Further, the average of the melt flow rates of the polystyrene resins obtained in each measurement was set as the melt flow rate of the polystyrene resin.

Melt tension (MT) measured at 200 ° C of the above polystyrene resin It is preferably 5 cN or more, and more preferably 7 cN or more. When the melt tension of the polystyrene-based resin is less than 5 cN, the strength and the impact resistance of the foam obtained by heating the expandable polystyrene resin particles are lowered.

<Method for Measuring Melt Tension (MT)>

In the present invention, the melt tension is a value measured by a capillary rheometer. For example, measurement is performed using a Twin-Bore Capillary Rheometer Rheologic 5000T (manufactured by Italian CEAST). Specifically, the test sample resin was first filled in a cylinder having a diameter of 15 mm which had been heated to a test temperature of 200 ° C, and then preheated for 5 minutes. Next, from the orifice of the piston extrusion type plastometer of the above measuring device (caliber 2.095 mm, length 8 mm, inflow angle 90 degrees (conical)), the piston lowering speed (0.07730 mm/s) is kept constant for strip extrusion. At the same time, the obtained ribbon was passed through a tension detecting pulley located 27 cm below the above-mentioned orifice. Subsequently, the above-mentioned ribbon was slowly increased and taken up at a take-up speed of 3.94388 mm/s at an initial speed of 12 mm/s ² using a take-up roll. Moreover, the maximum value before the point when the strip is cut. The average tension of the minimum value is set to the melt tension (MT) of the sample resin.

The methanol soluble fraction of the aforementioned polystyrene resin is 0.1 to 5.0 The mass % is preferably from 0.5 to 4.0% by mass. When the methanol-soluble fraction of the polystyrene-based resin is less than 0.1% by mass, the foaming ratio of the foam obtained by heating the expandable polystyrene-based resin particles is not increased, and the appearance is deteriorated. When the strength is less than 5.0% by mass, the foam obtained by heating the expandable polystyrene resin particles has heat resistance, strength, and impact resistance. Low concern.

<Method for Measuring Methanol Soluble Fraction>

In the present invention, the methanol soluble fraction is obtained by the following method.

3.5 g of a polystyrene resin was dissolved in 100 mL of a toluene solvent. Next, it was slowly added to 600 mL of methanol while stirring to precipitate methanol insoluble. After filtering to distinguish the methanol insoluble fraction, methanol was insoluble and dried to remove methanol. The mass of the obtained dried sample was measured and the methanol soluble component was determined using the following formula.

Methanol soluble fraction = {3.5-(a)} / 3.5 × 100 (% by mass)

Here, a represents the mass (g) of the dried sample.

Used as the expandable polystyrene resin particles of the present invention. The polystyrene resin is not particularly limited, and examples thereof include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, ethylstyrene, isopropylstyrene, and dimethylbenzene. A homopolymer of a styrene monomer such as ethylene or brominated styrene or a copolymer thereof is preferably a polystyrene resin containing 50% by mass or more of styrene, and more preferably polystyrene.

Further, the polystyrene resin may be the aforementioned styrene a copolymer of a styrene monomer having a olefin monomer as a main component and a vinyl monomer copolymerizable with the styrene monomer, and examples of such a vinyl monomer include (meth)acrylic acid. Methyl (meth) acrylate, butyl (meth) acrylate, alkyl (meth) acrylate such as cetyl (meth) acrylate; (meth) acrylonitrile, dimethyl maleate Diester monomer such as ester, dimethyl fumarate, diethyl fumarate, ethyl fumarate, and divinylbenzene, alkylene glycol dimethacrylate Wait.

Moreover, as long as it is a polystyrene resin, it may be added. Other resins, as the resin to be added, for example, in order to improve the punching resistance of the foamed molded article, three-dimensional copolymerization of polybutadiene, styrene-butadiene copolymer, and ethylene-propylene-nonconjugated diene A rubber-modified polystyrene-based resin to which a diene-based rubber-like polymer is added, or so-called high-impact polystyrene. Further, a polyethylene resin, a polypropylene resin, an acrylic resin, an acrylonitrile-styrene copolymer, an acrylonitrile-butadiene-styrene copolymer, or the like can be given.

As a polystyrene resin used as a raw material, in addition to being able to use the city It is also possible to use a non-recycled polystyrene resin (new polystyrene) such as a polystyrene resin which is newly produced by a suspension polymerization method or the like. The polystyrene-based resin foam molded body is subjected to a regenerated polystyrene resin obtained by a regeneration treatment. As the regenerated polystyrene-based resin, a used polystyrene-based resin foam molded body, for example, a fish tank, a home appliance cushioning material, a food packaging tray, or the like can be recovered and reduced by a terpene dissolution method or heating. A polystyrene resin regenerated in a manner. In addition, the regenerated polystyrene-based resin that can be used can be used in addition to the regenerated polystyrene-based resin foam molded body, and can be used as a home appliance (for example, a television, a refrigerator, a washing machine, or the like). The air conditioner (the air conditioner) and the transaction machine (for example, a photocopier, a facsimile machine, a printer, etc.) are used to separate and collect the non-foamed polystyrene resin molded body, and pulverize, melt-knead, and granulate. Styrene resin.

The foamed polystyrene resin particles of the present invention contain hair Examples of the foaming agent include aliphatic hydrocarbons such as propane, n-butane, isobutane, n-pentane, isopentane, and neopentane; 1,1-dichloro-1-fluoroethane (HCFC-141b), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123), chlorodifluoromethane (HCFC-22), 1-chloro-1,2,2,2-tetrafluoroethane ( HCFC-124) and other chlorofluorocarbons; 1,1-difluoroethane (HFC-152a), 1,1,1-trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), difluoromethane (HFC-32) and other fluorocarbons; various alcohols, carbon dioxide, water, and nitrogen The foaming agent can be used alone or in combination of two or more. Among these, examples of the particularly preferred foaming agent include n-butane, isobutane, n-pentane, and isopentane. The amount of the foaming agent to be added is in the range of 1 to 15 parts by mass, preferably in the range of 3 to 12 parts by mass, per 100 parts by mass of the polystyrene-based resin.

The foamable polystyrene resin particles of the present invention are contained The coloring agent can be appropriately selected from among the well-known coloring agents used for the coloring of the resin in the field of processing of a thermoplastic resin such as a polystyrene resin, and examples thereof include inorganic pigments, organic pigments, and dyes. Wait. One or two or more kinds of inorganic pigments and organic pigments are preferably used among the above-mentioned colorants.

The foamable polystyrene resin particles of the present invention are contained Examples of the inorganic pigments include carbon black, titanium oxide, iron oxide, iron hydroxide, chromium oxide, spinel calcined pigment, lead chromate, chromite vermilion, indigo, and aluminum. A powder, a bronze powder, etc. are mentioned, and as an extender pigment, a calcium carbonate type, a barium sulfate type, a cerium oxide type, and an aluminum hydroxide type are mentioned. Among these inorganic pigments, carbon black is particularly preferred.

The carbon contained in the expandable polystyrene resin particles of the present invention The black color is not particularly limited, and can be appropriately selected from various commercial products. In the present invention, for example, the product name "BLACK SPAB-851HC" manufactured by Sumitomo COLOR Co., Ltd., the product name "PS-M SSC 98H822A" manufactured by Daisei Seiki Co., Ltd., and "PS-M SSC MA6084A" are mentioned. The product names "MA-100" and "RCF #45" manufactured by Mitsubishi Chemical Corporation.

Examples of the organic pigment contained in the expandable polystyrene resin particles of the present invention include phthalocyanine, azo, condensed azo, anthraquinone, and picocyclic.苝, indigo. Thionine blue, isoindolinone, methylimine azo, two A quinacridone, an aniline black, a triphenylmethane or the like. Specifically, examples of the green pigment include CI Pigment Green 7, CI Pigment Green 26, CI Pigment Green 36, and CI Pigment Green 50. Examples of the yellow pigment include CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 17, CI Pigment Yellow 53, CI Pigment Yellow 55, CI Pigment Yellow 74, and CI Pigment. Yellow 83, CI Pigment Yellow 157, CI Pigment Yellow 161, CI Pigment Yellow 167, and the like. Examples of the red pigment include CI Pigment Red 48:1, CI Pigment Red 48:2, CI Pigment Red 48:4, CI Pigment Red 53:1, CI Pigment Red 57:1, CI Pigment Red 63:1. CI Pigment Red 122, CI Pigment Violet 19 and the like. Examples of the blue pigment include CI Pigment Blue 15, Pigment Blue 15:3, CI Pigment Blue 28, and the like. In addition, gold pigments, silver pigments, and the like can also be used.

The foamable polystyrene resin particles of the present invention are contained Examples of the dye include an azo dye, an anthraquinone dye, an anthraquinone dye, a quinone dye, a nitro dye, and a benzoquinone dye. Specifically, Solvent Blue 78, Solvent Yellow 167 (COLOR INDEX GENERIC NAME, the same below), Solvent Yellow 114, Solvent Yellow 163, Solvent Yellow 93, Solvent Yellow 33, Solvent Yellow 16, Solvent Green 5, Solvent Yellow 104, Solvent Orange 60, Solvent Yellow 14, Solvent Orange 63, Vat Red 41, Solvent Red 149, Solvent Red 111, Solvent Red 135, Solvent Red 179, SolventRed146, SolventRed22, SolventRed52, SolventViolet31, SolventViolet13, DisperseBlue165, DisperseBlue15, SolventGreen3, PigmentRed170, etc.

The hair of the present invention is made with respect to 100 parts by mass of the polystyrene resin The amount of the coloring agent contained in the foamable polystyrene resin particles is in the range of 0.3 to 9.0 parts by mass, preferably in the range of 0.5 to 7.0 parts by mass. When the amount of the colorant is less than the above range, the obtained foamed molded article has a low impact resistance, and the degree of coloration of the foamed molded article is insufficient. When the amount of the colorant is larger than the above range, the strength of the obtained foamed molded article is low.

The expandable polystyrene resin particles of the present invention are uniformly contained It is preferred to have one or both of an inorganic foaming nucleating agent and a chemical foaming agent.

Examples of the inorganic foaming nucleating agent include talc, ceria, strontium mineral powder, mica, clay, zeolite, calcium carbonate, and the like, among which talc, cerium oxide, and citric acid are particularly used. One or two or more kinds of salt mineral powders are preferred.

The amount of the above inorganic foaming nucleating agent is preferably in the range of 0.05 to 5.0 parts by mass, and preferably in the range of 0.1 to 2.0 parts by mass, based on 100 parts by mass of the polystyrene resin.

Examples of the chemical foaming agent include azobiscarboxyguanamine and N,N'- Dinitrosopentamethylenetetramine, 4,4'-oxybis(phenylsulfonate), sodium hydrogencarbonate, a mixture of sodium hydrogencarbonate and citric acid, etc., among others, especially from azo A mixture of dicarboxymethylamine, sodium hydrogencarbonate, sodium hydrogencarbonate and citric acid is preferably used singly or in combination of two or more.

The amount of the above chemical foaming agent is preferably in the range of 0.05 to 5.0 parts by mass, and preferably in the range of 0.1 to 3.0 parts by mass, per 100 parts by mass of the polystyrene-based resin.

The expandable polystyrene resin particles of the present invention are not damaged In the range of properties, additives such as a crosslinking agent, a plasticizer, a filler, a flame retardant, a flame retardant, a lubricant, and the like may be added, and in addition, in the form of the aforementioned expandable styrene resin particles When a powdery metal soap such as zinc stearate is applied to the surface, it is preferred to reduce the bonding between the polystyrene-based resin pre-expanded particles in the preliminary foaming step of the expandable polystyrene-based resin particles.

The particle size of the expandable polystyrene resin particles of the present invention is not particularly Not limited, it is usually in the range of 0.5 to 3.0 mm, and preferably in the range of 0.7 to 2.0 mm. Further, the shape of the particles is not particularly limited, and it is preferably a spherical shape or a substantially spherical shape.

The expandable polystyrene resin particles of the present invention have a foam diameter of from 0.055 to 0.125 g/cm ³ and an average cell diameter of 50 to 300 μm. The average cell diameter is preferably in the range of 60 to 250 μm, and preferably in the range of 70 to 200 μm. When the average cell diameter is less than 50 μm, there is a concern that the appearance of the foamed molded article is impaired and the strength is lowered. When the average cell diameter is more than 300 μm, the impact resistance of the foam molded article is deteriorated, and it is difficult to apply it to the use of a cushioning material such as a helmet core material or an automobile interior material.

In the foamable polystyrene resin particles of the present invention, the foamed molded article obtained by foam molding in a range of a density of 0.055 to 0.125 g/cm ³ has a punching acceleration G value of 300 G or less. Further, the so-called thrust acceleration G value indicates the maximum thrust acceleration applied to the object at the time of collision.

The G value is preferably 280 G or less, and more preferably 270 G or less. When the G value is more than 300 G, the impact resistance of the foam molded article is deteriorated, and it is difficult to apply it to the use of a cushioning material such as a helmet core material or an automobile interior material.

The expandable polystyrene resin particles of the present invention have a brightness of from 20 to 95 in a range of from 20 to 95, and from 21 to 94, in a foam molded article having a density of from 0.055 to 0.125 g/cm ³ . The range is preferably in the range of 22 to 93. Here, the brightness of the foamed molded article means a value measured in accordance with JIS Z8729.

When the brightness is less than 20, the impact resistance of the foam molded article is deteriorated, and it is difficult to apply it to the use of a cushioning material such as a helmet core material or an automobile interior material. On the other hand, when the brightness is more than 95, the degree of coloration of the foamed molded article is insufficient, and a foamed molded article having a good appearance cannot be obtained.

The expandable polystyrene resin particles of the present invention are obtained by granulating a polystyrene-based resin containing a physical foaming agent and a coloring agent, and are colored with respect to 100 parts by mass of the polystyrene resin. 0.3 to 9.0 parts by mass of the agent, and the average cell diameter in the foamed molded article obtained by foam molding in a range of a density of 0.055 to 0.125 g/cm ^{3 is} in the range of 50 to 300 μm, and the foamed molded body is washed. Since the acceleration G value is 300 G or less, or the luminance is in the range of 20 to 95, the resin particles are heated to perform preliminary foaming, and the obtained preliminary expanded particles are subjected to in-mold expansion molding to obtain strength. And a foamed molded body excellent in punching resistance.

Further, it is possible to obtain a foam molded article having a uniform coloration and good appearance.

(Method for Producing Foaming Polystyrene Resin Particles)

In the method for producing the expandable polystyrene resin particles of the present invention, the foaming agent is pressed into a polystyrene resin which has been melted in the resin supply device and kneaded, and the foaming agent is melted. The resin is directly extruded into the cooling liquid from the small hole of the mold attached to the front end of the resin supply device, and the extrudate extruded into the cooling liquid is cut by the rotary blade in the cooling liquid while The expandable polystyrene resin particles are obtained by bringing the extrudate into contact with a liquid to be solidified by cooling. The method for producing the expandable polystyrene resin particles is referred to as a melt extrusion method.

In the method for producing expandable polystyrene-based resin particles of the present invention, it is characterized in that 0.3 to 9.0 parts by mass of the colorant is added to 100 parts by mass of the polystyrene-based resin, and the density is 0.055 to 0.125 g. In the foam molded article obtained by foam molding in the range of /cm ³ , the average cell diameter is in the range of 50 to 300 μm, and the foamed molded article has a punching acceleration G value of 300 G or less. Resin particles.

Fig. 1 is a view showing the expandable polystyrene resin particles of the present invention. A configuration diagram of an example of a manufacturing apparatus used in the manufacturing method of the present embodiment, the manufacturing apparatus of the present example includes an extruder 1 as a resin supply device, and a mold 2 is attached to the front end of the extruder 1 and There are a plurality of small holes; the raw material supply hopper 3 is used to put a resin raw material into the extruder 1; and the high pressure pump 4 is a molten resin which is pressed into the extruder 1 through the blowing agent supply port 5 The cutting chamber 7 is provided in such a manner that the cooling water contacts the resin discharge surface of the small hole through which the mold 2 is placed, and the cooling water is circulated and supplied to the chamber; the cutter 6 (high-speed rotary blade) is capable of rotating Moreover, the resin which is extruded from the small hole of the mold 2 can be cut in the cutting chamber 7; the dehydration dryer 10 is provided with a solid-liquid separation function, and can be accompanied by the cooling water flow from the cutting chamber 7. The foamable polystyrene resin particles to be transported are dehydrated and dried while being separated from the cooling water to obtain expandable polystyrene resin particles, and the water tank 8 is provided with a solid-liquid separation function. The dehydration dryer 10 is separated from the cooled water; high pressure Pu 9 is used to transport the cooling water in the water tank 8 to the cutting chamber 7; and the storage container 11 is an expandable polystyrene resin particle which is dehydrated and dried by the dehydration dryer 10 having a solid-liquid separation function. Store.

Moreover, as the extruder 1, it can be an extruder using a screw or not Any of the extruders using a screw. As an extruder using a screw, for example, Single-axis extruder, multi-axis extruder, venting extruder, tandem extruder, etc. Examples of the extruder that does not use a screw include a plunger extruder, a gear pump extruder, and the like. Also, any extruder can use a static mixer. Among these extruders, it is preferable to use a screw extruder in terms of productivity. Further, the cutting chamber 7 in which the cutter 6 is housed can also be used as previously known in the granulation method by melt extrusion of a resin.

Making foamy polystyrene using a manufacturing apparatus as shown in FIG. In the case of the olefin-based resin particles, first, one or both of the above-mentioned polystyrene-based resin, coloring agent, inorganic foaming nucleating agent, and chemical foaming agent, and additives required as needed, are weighed. The raw material supply hopper 3 is put into the extruder 1. The polystyrene-based resin of the raw material may be pelletized or granulated and sufficiently mixed in advance, and then supplied from one raw material supply hopper, or, for example, when a plurality of batches are used, a plurality of raw materials may be adjusted from the respective batches. The feed hopper is put in and mixed in the extruder. Further, when a plurality of batches of recycled raw materials are used in combination, it is preferred to sufficiently mix the raw materials of the plurality of batches in advance, and it is preferable to remove the foreign matter in advance by using an appropriate sorting means such as magnetic gas sorting, screening, specific gravity sorting, and air sorting.

Polystyrene resin, colorant, inorganic foaming agent and chemistry After one or both of the foaming agents and the required additives to be added as needed are supplied to the extruder 1, the resin is heated and melted, and the molten resin is transferred to the side of the mold 2 while being supplied from the blowing agent. (5) The molten resin is mixed with the foaming agent by pressurizing the foaming agent by the high pressure pump 4, and the mesh for removing foreign matter in the extruder 1 is optionally pulverized, and the melt is further kneaded while being Moving to the front end side, the melt to which the foaming agent is added is extruded from the small hole of the mold 2 attached to the front end of the extruder 1.

When the coloring agent is put into the extruder 1, it is preferred to use a polystyrene system in advance. A masterbatch containing a colorant prepared by melt-mixing a resin and a coloring agent is preferred.

The resin discharge surface of the small hole provided with the mold 2 is arranged to be cooled The water is circulated and supplied into the cutting chamber 7 in the room, and in the cutting chamber 7, the rotatable cutter 6 is provided so as to be able to cut the resin extruded from the small hole of the mold 2. When the melted material to which the foaming agent has been added is extruded from the small hole of the mold 2 attached to the front end of the extruder 1, the melt is cut into pellets, and is rapidly cooled by contact with the cooling water, and is suppressed. The foamed polystyrene resin particles are cured in a foamed state.

The foamed polystyrene resin particles formed are accompanied by The cooling water flow in the cutting chamber 7 is transported to a dehydration dryer 10 having a solid-liquid separation function, where the expandable polystyrene resin particles are separated from the cooling water, and dehydrated and dried, and the dried foaming polymerization is performed. The styrene resin particles are stored in the storage container 11.

The method for producing the expandable polystyrene resin particles of the present invention is a method for producing expandable polystyrene resin particles by a melt extrusion method, and is obtained by using 100 parts by mass of a polystyrene resin. The coloring agent is added in an amount of from 0.3 to 9.0 parts by mass, and the foamed molded article obtained by foam molding in a range of from 0.055 to 0.125 g/cm ³ has an average cell diameter of 50 to 300 μm, and the foaming is carried out. Since the punching acceleration G value of the molded article is a composition of expandable polystyrene resin particles of 300 G or less, it is possible to efficiently produce a foam molded article which is excellent in strength and impact resistance and has a good uniform color appearance. Foaming polystyrene resin particles.

(prepared foamed particles and foamed molded body)

The expandable polystyrene resin particles of the present invention are preliminarily foamed by heating by steam heating or the like using a device and a method well known in the field of production of a foamed resin molded body to obtain preliminary expanded beads. The preliminary expanded beads are preliminarily foamed so as to have a bulk density equivalent to the density of the foam molded body to be produced. In the present invention, the bulk density is not limited, but is usually set in the range of 0.010 to 0.15 g/cm ³ , and is applied to a cushioning material such as a helmet core material or an automobile interior material to be set to 0.055 to 0.125 g. Within the range of /cm ³ is preferred.

Further, in the present invention, the bulk density of the preliminary expanded particles means JIS K6911: The value measured in 1995, "General Test Method for Thermosetting Plastics".

<Volume density of preliminary expanded particles>

First, Wg preliminary foamed particles were used as a measurement sample, and the measurement sample was naturally dropped into a measuring cylinder, and the volume Vcm ³ of the measurement sample that had fallen into the measuring cylinder was measured using an apparent density measuring instrument according to JIS K6911, and based on the following. The bulk density of the pre-expanded particles was determined by the formula.

Bulk density (g/cm ³ ) = mass of the measured sample (W) / volume of the measured sample (V)

<Volume expansion ratio of preliminary expanded particles>

Further, the volume expansion ratio of the preliminary expanded particles is a value calculated according to the following formula.

Volume expansion ratio = 1 / volume density (g / cm ³ )

The pre-expanded particles are filled in a cavity of a molding die by using a well-known apparatus and method in the field of manufacturing a foamed resin molded body, and are heated by steam heating or the like. Foam molding to produce a foam molded body.

The density of the foamed molded article of the present invention is not particularly limited, and is usually in the range of 0.010 to 0.15 g/cm ³ , and is applied to a cushioning material such as a helmet core material or an automobile interior material to be set to 0.055 to It is preferably in the range of 0.125 g/cm ³ .

Further, in the present invention, the density of the foamed molded body is JIS. K7122: 1999 "Foamed plastic and rubber - Determination of apparent density" The density of the foamed molded body measured by the method.

<Density of foamed molded body>

The test piece of 50 cm ³ or more was cut so as not to change the original cell structure of the material, and the mass was measured and calculated according to the following formula.

Density (g/cm ³ ) = test piece mass (g) / test piece volume (cm ³ )

<Test piece status adjustment>

The test piece for measurement was cut out from a sample which was subjected to 72 hours or more after molding, and left at an environment of 23 ° C ± 2 ° C × 50% ± 5% or 27 ° C ± 2 ° C × 65% ± 5% for 16 hours or more.

<Foaming multiple of foamed molded body>

Further, the expansion ratio of the foam molded article is a value calculated according to the following formula.

Foaming multiple = 1 / density (g / cm ³ )

The foamed molded article of the present invention is obtained by foam molding a foamable polystyrene resin particle containing a colorant; and the colorant content is from 0.3 to 9.0 parts by mass based on 100 parts by mass of the polystyrene resin. In the range of the density of 0.055 to 0.125 g/cm ³ , the average cell diameter is in the range of 50 to 300 μm, and the punching acceleration G value is 300 G or less. Therefore, the film has excellent strength and impact resistance, and has a good appearance of uniform coloration. The foam molding system of the present invention is suitable as a cushioning material such as a helmet core material or an automobile interior decoration material.

[Examples]

[Example 1]

(Manufacture of expandable polystyrene resin particles)

Adding 0.3 parts by mass of fine powder talc as an inorganic foaming nucleating agent to 100 parts by mass of a new material polystyrene (manufactured by Toyo Styrene Co., Ltd., trade name "HRM-10N") having a mass average molecular weight of 200,000 One part by mass of carbon black (RCF #45, manufactured by Mitsubishi Chemical Corporation) was continuously supplied to a uniaxial extruder having a diameter of 90 mm at 150 kg per hour. The temperature in the extruder is set to a maximum temperature of 210 ° C, and after melting the resin, 4 parts by mass of pentane (isopentane: n-pentane = 20: 80) is used as a blowing agent with respect to 100 parts by mass of the resin. It is pressed in from the way of the extruder. The resin and the foaming agent were kneaded in the extruder while being cooled, and the resin temperature at the front end portion of the extruder was maintained at 170 ° C, the pressure at the resin introduction portion of the mold was maintained at 15 MPa, and 200 diameters were arranged. a mold having a small hole of 0.6 mm and a land length of 3.0 mm, and extruding a molten resin containing a foaming agent to a cutting chamber which is connected to the discharge side of the mold and circulated at 30 ° C in water. At the same time, the extrudate was cut using a high-speed rotary cutter having 10 blades in the circumferential direction. The cut particles are cooled using circulating water while being transported to a particle separator to separate the particles from the circulating water. Moreover, the trapped particles are dehydrated. The foaming polystyrene resin particles were obtained by drying. The obtained expandable polystyrene resin particles are substantially completely spherical without deformation, whiskers, and the like, and have an average particle diameter of about 1.1 mm.

0.03 parts by mass of polyethylene glycol, 0.15 parts by mass of zinc stearate, 0.05 parts by mass of monoglyceryl stearate, and 0.05 parts by mass of hydroxy group per 100 parts by mass of the obtained expandable polystyrene resin particles. The triglyceride fatty acid is uniformly coated on the entire surface of the expandable polystyrene resin particles.

The polystyrene resin of the obtained expandable polystyrene resin particles was allowed to stand in an environment of 145 ° C for 2 hours to volatilize the foaming agent, and then the MFR was measured. MT and methanol are soluble. The results are shown in Table 2.

(Manufacture of foamed molded body)

The expandable polystyrene resin particles produced as described above were placed in a refrigerator at 15 ° C, and left for 72 hours, and then supplied to a cylindrical batch type preliminary foaming machine using water vapor having a blowing pressure of 0.05 MPa. Heating was carried out to obtain pre-expanded particles. The bulk density of the obtained preliminary expanded beads was 0.083 g/cm ³ (volume expansion ratio 12 times).

Next, after the obtained preliminary expanded particles were allowed to stand in a room temperature environment for 24 hours, the preliminary expanded particles were filled in a molding die having a rectangular cavity having a length of 400 mm, a width of 300 mm, and a height of 25 mm, and then, The mold cavity of the forming mold was heated with water vapor at a gauge pressure of 0.08 MPa for 20 seconds, and then the pressure was cooled to 0.01 MPa in the cavity of the forming mold, and then the forming mold was opened to have a length of 400 mm × width. A rectangular foam molded body of 300 mm × height 25 mm was taken out. The density of the obtained foam molded article was 0.083 g/cm ³ (foaming ratio 12 times).

Foaming forming for Example 1 produced using the method as described above The measurement described in <Measurement of average cell diameter>, <Evaluation of strength>, <Measurement of G value of punching acceleration> and <Measurement of brightness> is performed as follows. Evaluation. The results are shown in Table 1.

<Measurement of average bubble diameter>

The foamed molded article obtained in the examples (and the comparative examples) was cut with a razor blade, and the cut surface was magnified by 30 times using a scanning electron microscope (S-3000N, manufactured by Hitachi, Ltd.). The captured image was printed on A4 paper, and the average chord length (t) of the bubble was calculated from the number of bubbles located on an arbitrary straight line (length 60 mm) according to the following formula. However, any straight line is such that the bubble is not in contact with the cut point as much as possible (the number of bubbles is included in the contact). The measurement system is set to 10, after obtaining the average chord length, The bubble diameter was calculated and set as the average bubble diameter D (μm).

Average chord length t=60/(number of bubbles × magnification of photos)

Bubble diameter D=t/0.616×1000

<Evaluation of strength>

The foamed molded article obtained in the examples (and comparative examples) was measured for bending strength in accordance with the method described in JISA9511:2006 "foamed plastic heat insulating material".

In other words, the TENSILON universal testing machine UCT-10T (manufactured by ORIENTEC Co., Ltd.) was used, and the test body size was set to 75 mm × 300 mm × 25 mm, the compression speed was set to 10 mm/min, and the front end jig was set to the wedge pressure 10R, the support table 10R, and the fulcrum. The measurement was carried out under the conditions of a distance of 200 mm, and the bending strength was calculated using the following formula. The number of test pieces was set to three, and the average value was obtained.

Bending strength (MPa) = 3FL / 2bh ²

(here, F represents the maximum bending load (N), L represents the distance between the fulcrums (mm), b represents the width (mm) of the test piece, and h represents the thickness (mm) of the test piece)

The average value of the bending strength was obtained in this manner, and the strength was evaluated in accordance with the following evaluation criteria.

12 times molded product evaluation standard

The bending strength is 1.40 MPa or more: Tejia (◎)

The bending strength is 1.30 MPa or more and less than 1.40 MPa: good (○)

Bending strength is less than 1.30MPa: bad (×)

Evaluation criteria for 50 times molded product: bending strength is 0.28 MPa or more: Tejia (◎)

The bending strength is 0.25 MPa or more and less than 0.28 MPa: good (○)

Bending strength is less than 0.25MPa: bad (×)

<Measurement of G value of thrust acceleration>

From the foam molded articles obtained in the examples (and comparative examples), three square-shaped foam molded articles having a length of 150 mm, a width of 150 mm, and a height of 25 mm were cut out.

Next, a commercially available double-sided adhesive tape (manufactured by NICHIBAN Co., Ltd., product name: NW-50) was used to mount the length of the molded foam sample of 150 mm × width 150 mm in a Yoshida Seiki machine at a temperature of 23 ° C and a humidity of 50%. The rack (quality: 5.8 kg) of the drop tester (ADST-200) manufactured by the company was dropped naturally from the lower side of the foamed molded body to a height of 18 cm. The thrust acceleration received by the gantry when falling was measured, and the average value of the three times was set to the G value.

Further, when measuring the thrust acceleration G value of the foam molded body such as a helmet liner, for example, 45 foam molded bodies of 50 mm × 50 mm × 5 mm can be cut out from the helmet liner to conform to the above-mentioned sample size (length 150 mm × width 150 mm) The pattern of the height of 25 mm was attached to a square shape for measurement.

<Measurement of brightness>

The brightness (L value) of the polystyrene resin foam of the present invention is determined from the results of the method according to JIS Z8729. The measuring instrument used the ONICA INOLTA Color Difference Meter CR-410.

[Embodiment 2]

A foam molded article was produced in the same manner as in Example 1 except that the amount of carbon black added was changed to 4 parts by mass. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Example 3]

A foam molded product was produced in the same manner as in Example 1 except that the amount of carbon black added was changed to 7 parts by mass. The obtained foam molded body was carried out in the same manner as in Example 1. Sample determination. Evaluation. The results are shown in Table 1.

[Example 4]

In addition to the addition of 0.5 part by mass of a chemical foaming agent (a mixture of sodium hydrogencarbonate and citric acid, manufactured by Yonghe Chemical Co., Ltd., trade name "olythene ES405"), in addition to the fine powder talc, Example 1 was carried out in the same manner to obtain a foam molded article. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Example 5]

A foam molded article was produced in the same manner as in Example 1 except that the amount of the carbon black added was 2 parts by mass and 0.5 part of the chemical foaming agent was additionally added. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Embodiment 6]

A foamed molded article was produced in the same manner as in Example 1 except that 3 parts by mass of C.I. Pigment Green 7 (Anthocyanin Green 2GN, manufactured by Dairi Seiki Co., Ltd.) was added in place of the carbon black. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Embodiment 7]

A foam molded article was produced in the same manner as in Example 1 except that 5 parts by mass of C.I. Pigment Yellow 161 (Diproxide Yellow #9123, manufactured by Dairi Seiki Co., Ltd.) was added to the yellow organic pigment. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Embodiment 8]

In addition to adding 3 parts by mass of red organic pigment C.I. Pigment Red 48:1 (8040 A foam molded article was produced in the same manner as in Example 1 except that carbon black was used instead of carbon black. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Embodiment 9]

A foam molded article was produced in the same manner as in Example 1 except that 3 parts by mass of C.I. Pigment Blue 15:3 (Cyanine Blue 4937, manufactured by Dairi Seiki Co., Ltd.) was added in place of the blue organic pigment. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Embodiment 10]

The same procedure as in Example 1 was carried out except that the new material polystyrene was changed to a new material polystyrene (manufactured by Toyo Styrene Co., Ltd., trade name "HRM-13N") having a mass average molecular weight of 280,000 as shown in Table 3. Formed into a foamed molded body. The same measurements as in Example 1 were carried out on the obtained expandable polystyrene resin particles and the foam molded article. Evaluation. The results are shown in Tables 1 and 2.

[Example 11]

A foamed molded article was produced in the same manner as in Example 1 except that the new material polystyrene was changed to the recycled raw material (1) shown in Table 3. The same measurements as in Example 1 were carried out on the obtained expandable polystyrene resin particles and the foam molded article. Evaluation. The results are shown in Tables 1 and 2.

[Embodiment 12]

A foamed molded article was produced in the same manner as in Example 1 except that the new material polystyrene was changed to the recycled raw material (2) shown in Table 3. The same measurements as in Example 1 were carried out on the obtained expandable polystyrene resin particles and the foam molded article. Evaluation. The results are shown in Tables 1 and 2.

[Example 13]

A foamed molded article was produced in the same manner as in Example 1 except that the new material polystyrene was changed to the recycled raw material (3) shown in Table 3. The same measurements as in Example 1 were carried out on the obtained expandable polystyrene resin particles and the foam molded article. Evaluation. The results are shown in Tables 1 and 2.

[Embodiment 14]

A foamed molded article was produced in the same manner as in Example 1 except that the new material polystyrene was changed to the recycled raw material (4) shown in Table 3. The same measurements as in Example 1 were carried out on the obtained expandable polystyrene resin particles and the foam molded article. Evaluation. The results are shown in Tables 1 and 2.

[Example 15]

The same procedure as in Example 1 was carried out, except that the new material polystyrene was changed to a new material polystyrene (manufactured by Toyo Styrene Co., Ltd., trade name "HRM-30") having a mass average molecular weight of 430,000 as shown in Table 3. Formed into a foamed molded body. The same measurements as in Example 1 were carried out on the obtained expandable polystyrene resin particles and the foam molded article. Evaluation. The results are shown in Tables 1 and 2.

[Comparative Example 1]

A foam molded article was produced in the same manner as in Example 1 except that carbon black was not added. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

[Comparative Example 2]

A foam molded article was produced in the same manner as in Example 1 except that the amount of carbon black added was changed to 10 parts by mass. The same measurement as in Example 1 was carried out for the obtained foam molded article. Evaluation. The results are shown in Table 1.

As is apparent from the results of Table 1, the examples 1 to 15 of the present invention were fabricated. The foamed molded body is excellent in strength and good in impact resistance.

Moreover, the foamed molded article obtained in Examples 1 to 5 using carbon black as a coloring agent has a low brightness and is colored uniformly black, and has a good appearance.

The foamed molded articles obtained in Examples 6 to 9 using an organic pigment as a coloring agent were relatively bright in green (Example 6), yellow (Example 7), pink (Example 8), and blue. The color of each color (Example 9) is clear and uniform in coloration, and the appearance is good.

On the other hand, compared to Examples 1 to 5, the ratio of carbon black is not added. The foamed molded article produced in Comparative Example 1 was inferior in punching resistance.

In addition, in Comparative Example 2, when the amount of carbon black added is 10 parts by mass, the internal fusion is deteriorated, and the appearance of the foamed molded article is deteriorated, and the strength is poor.

(industrial availability)

The present invention relates to an expandable polystyrene resin capable of obtaining a foamed molded article having excellent strength and impact resistance, uniform coloration, and superior appearance. Particles and a method for producing the same, a polystyrene-based resin pre-expanded particle, and a polystyrene-based resin foam molded article.

1‧‧‧Extrusion machine (resin supply unit)

2‧‧‧Molding

3‧‧‧Material supply hopper

4‧‧‧High pressure pump

5‧‧‧Blowing agent supply port

6‧‧‧Cutter

7‧‧‧ cutting room

8‧‧‧Sink

9‧‧‧High pressure pump

10‧‧‧Dehydration dryer with solid-liquid separation function

11‧‧‧ storage container

Claims (17)

a foamable polystyrene-based resin particle containing a physical foaming agent, a coloring agent, and a polystyrene-based resin, and containing 0.3 to 9.0 parts by mass of the coloring agent per 100 parts by mass of the polystyrene-based resin. The melt flow rate (MFR) measured at 200 ° C of the polystyrene resin is in the range of 1.0 to 10.0 g/10 min, and the melt tension (MT) measured at 200 ° C is 5 cN or more, and the density is 0.055 to 0.125 g/cm. ^In the foam molded article obtained by foam molding the foamable polystyrene resin particles in the range of ³ , the average cell diameter is in the range of 50 to 300 μm, and the G value of the punching acceleration of the foam molded article is Below 300G. a foamable polystyrene-based resin particle containing a physical foaming agent, a coloring agent, and a polystyrene-based resin, and containing 0.3 to 9.0 parts by mass of the coloring agent per 100 parts by mass of the polystyrene-based resin. The melt flow rate (MFR) measured at 200 ° C of the polystyrene resin is in the range of 1.0 to 10.0 g/10 min, and the melt tension (MT) measured at 200 ° C is 5 cN or more, and the density is 0.055 to 0.125 g/cm. ^The foamed molded article obtained by foam molding the foamable polystyrene resin particles in the range of ^{3 is} in the range of 20 to 95 in accordance with JIS Z8729. The expandable polystyrene resin particles according to claim 1 or 2, further comprising one or both of an inorganic foaming nucleating agent and a chemical foaming agent, a coloring agent, and an inorganic foaming nucleating agent. One or both of the chemical foaming agents are uniformly contained in the entire expandable polystyrene resin particles (however, internal bubbles Except for). The expandable polystyrene-based resin particles according to the first or second aspect of the invention, wherein the coloring agent is one or more selected from the group consisting of inorganic pigments and organic pigments. The expandable polystyrene-based resin particles according to the first or second aspect of the invention, wherein the polystyrene-based resin has a methanol soluble component in a range of from 0.1 to 5.0% by mass. The expandable polystyrene resin particles according to claim 1 or 2, which are produced by a melt extrusion method in which a foaming agent is pressed into a resin supply device. The molten resin is melted in the molten polystyrene resin, and the molten resin containing the foaming agent is directly extruded from the small hole of the mold attached to the tip end of the resin supply device into the cooling liquid, and is extruded to the inside. The extrudate in the cooling liquid is cut by a rotary blade in the cooling liquid while being cooled and solidified by bringing the extrudate into contact with the aforementioned liquid. A method for producing foamable polystyrene resin particles, which are produced by a melt extrusion method; the melt extrusion method presses a physical foaming agent into a resin The polystyrene-based resin containing the coloring agent in the supply device is kneaded, and the molten resin containing the foaming agent is directly extruded from the small hole of the mold attached to the tip end of the resin supply device to the cooling liquid. The extrudate which has been extruded into the cooling liquid is cut by a rotary blade in the cooling liquid, and is cooled and solidified by bringing the extrudate into contact with the liquid to obtain the expandable polystyrene resin. The foaming polystyrene resin particles are 0.3 to 9.0 parts by mass of a coloring agent added to 100 parts by mass of the polystyrene resin, and the melt flow rate (MFR) of the polystyrene resin measured at 200 ° C In the range of 1.0 to 10.0 g/10 min, the melt tension (MT) measured at 200 ° C is 5 cN or more, and the foam molded body is obtained by foam molding in a range of a density of 0.055 to 0.125 g/cm ³ . Average bubble diameter in the range of 50 to 300 μm And the foamed molded IMPACT acceleration G is 300G or less. The method for producing expandable polystyrene resin particles according to claim 7, wherein the foam molded article obtained by foam molding in a density of 0.055 to 0.125 g/cm ³ is obtained according to JIS. The expandable polystyrene resin particles having a luminance of from 20 to 95 were measured by Z8729. The method for producing expandable polystyrene resin particles according to claim 7 or 8, wherein one of the inorganic foaming agent and the chemical foaming agent is further added to the polystyrene resin or One or both of the coloring agent, the inorganic foaming nucleating agent, and the chemical foaming agent are uniformly contained in the expandable polystyrene resin particles (except for the internal bubbles). Ethylene resin particles. The method for producing the expandable polystyrene-based resin particles according to the above-mentioned item, wherein the coloring agent is one or more selected from the group consisting of inorganic pigments and organic pigments. The method for producing expandable polystyrene-based resin particles according to the seventh aspect of the invention, wherein the polystyrene-based resin has a methanol soluble component in a range of from 0.1 to 5.0% by mass. A pre-expanded foamed particle obtained by heating and foaming the expandable polystyrene-based resin particles according to any one of claims 1 to 6. A foamed molded article obtained by filling the pre-expanded particles described in claim 12 into a cavity of a molding die, heating, and performing in-mold expansion molding. A foamed molded article obtained by foam molding a foamable polystyrene resin particle containing a physical foaming agent, a coloring agent, and a polystyrene resin, wherein 100 parts by mass of polystyrene is used. The resin contains 0.3 to 9.0 parts by mass of a colorant, and the melt flow rate (MFR) measured at 200 ° C of the polystyrene resin is in the range of 1.0 to 10.0 g/10 minutes, and the melt tension (MT) measured at 200 ° C is 5cN or more, the average cell diameter in the range of density 0.055 to 0.125 g/cm ^{3 is} in the range of 50 to 300 μm, and the punching acceleration G value is 300 G or less. The foamed molded article according to claim 14, wherein the colorant is one or more selected from the group consisting of inorganic pigments and organic pigments. The foamed molded article according to any one of claims 13 to 15, which is used for a helmet core material. The foamed molded article according to any one of claims 13 to 15, which is used for automotive interior materials.