JP6815810B2 - Expandable polystyrene resin particles - Google Patents

Description

The present invention relates to effervescent polystyrene resin particles.

Effervescent polystyrene-based resin particles are a socially useful material because they are relatively inexpensive, can be foam-molded with steam or the like without using a special method, and have high cushioning and heat insulating effects.

The effervescent polystyrene-based resin particles are obtained, for example, by adding a foaming agent (that is, easily volatile aliphatic hydrocarbons such as butane, pentane, etc., which only slightly swell the particles) to the polystyrene-based resin particles in an aqueous suspension. Manufactured by the impregnation method. The expanded polystyrene-based resin particles produced in this manner are used as a raw material for producing an expanded polystyrene-based resin molded product.

As a method for industrially and economically producing a expanded polystyrene-based resin molded product, the expanded polystyrene-based resin particles are made into pre-expanded particles by steam or the like, and the pre-expanded particles are used as a large number of small holes in a wall surface having a desired shape. Is filled in a closed mold, and a heating medium such as water vapor is ejected from the small pores of the mold to heat it to a temperature above the softening point of the pre-foamed particles, fuse them together, and then cool them. There is a method of producing a foamed styrene resin molded product having a desired shape by taking it out from the mold through the steps.

Further, in the stage of obtaining the pre-foamed particles, a state in which the pre-foamed particles are bonded to each other (called blocking) is eliminated by applying a powdery external additive.

On the other hand, in recent years, the powder, which is an external additive, has peeled off in the market, resulting in an increase in the amount of steam used due to clogging of the filter by resin granulation during pre-foaming and the slit of the mold during molding, and piping during granulation. Problems such as deterioration of liquidity due to clogging have occurred. However, powder had to be used to suppress blocking in prefoaming.

In Patent Document 1, by applying methylphenyl silicone oil (refractive index of 1.45 or more at 25 ° C.) and a metal salt of a higher fatty acid to the surface of foamable polystyrene resin particles, the molding cycle is shortened and the strength is shortened. There have been proposed foamable polystyrene-based resin particles for obtaining a molded product having excellent and glossy surface properties, and a method for producing the same. However, in this method, since the filter by resin granulation at the time of pre-foaming and the powder (metal salt of higher fatty acid) that may block the slit of the mold at the time of molding are essential components, the powder The filter clogging and mold contamination have not been improved due to the peeling of the resin.

Further, in Patent Document 2, by using a blocking inhibitor and a surface modifier having an effect of shortening the cooling time during molding on the surface of the foamable polystyrene resin particles, blocking during preliminary foaming is suppressed and the cycle is further shortened. A method for producing effervescent polystyrene-based resin particles to obtain the effect has been proposed. However, in this method, although the cooling time at the time of molding is shortened by the surface modifier, fine cracks are formed in the surface bubbles of the molded body, so that the surface property of the molded body is deteriorated, the strength is lowered, and the cracks are formed. There is a fear.

In Patent Document 3, by coating the surface of foamable polystyrene-based resin particles with dimethylpolysiloxane and methylphenylpolysiloxane in Examples, the mold filling rate at the time of molding is improved, and further, molding with good surface properties is performed. Expandable polystyrene-based resin particles for obtaining a body and a method for producing the same have been proposed. However, since dimethylpolysiloxane is used in this method, the compatibility with polystyrene is lower than that of methylphenylpolysiloxane, and the blocking suppressing effect is lowered.

In Patent Document 4, 15 mL of dimethylpolysiloxane (0.0965 parts by weight per 100 parts by weight of foamable polystyrene resin particles) is impregnated in the vicinity of the surface layer of foamable polystyrene resin particles, and then silicone oil containing a phenyl group is applied to the surface. By coating 0.02 parts by weight or more and 0.10 parts by weight or less, and further applying powders such as behenyl acid triglyceride and ethylene bisstearic acid amide, blocking is suppressed and a good surface-based molded product is obtained. Foamable polystyrene-based resin particles for this purpose have been proposed. However, in this method, it is necessary to impregnate dimethylpolysiloxane with a foaming agent in water at high temperature and high pressure, and the productivity is inferior to that of the method in which an external additive is attached. In addition, by applying a powder external additive such as behenic acid triglyceride and ethylene bisstearic acid amide, the surface quality is improved and blocking during pre-foaming is prevented, but filter clogging due to powder peeling and Mold contamination has not been improved.

JP-A-2007-246705 Japanese Unexamined Patent Publication No. 60-203647 Japanese Patent Application Laid-Open No. 02-003435 Japanese Patent Application Laid-Open No. 03-177438

In view of the above circumstances, an object of the present invention is foamability suitable for obtaining a molded product having good fusion properties and surface properties, while suppressing powder peeling and preventing blocking. The purpose is to provide polystyrene-based resin particles.

The present inventors have completed the present invention as a result of diligent research aimed at improving the above-mentioned drawbacks of the prior art.

That is, in the first aspect of the present invention, 0.03 parts by weight to 0.03 parts by weight of methylphenylpolysiloxane A having a refractive index at 25 ° C. of 1.47 to 1.60 with respect to 100 parts by weight of foamable polystyrene resin particles. Effervescent by applying 0.01 part by weight to 0.06 part by weight of methylphenylpolysiloxane B having a refractive index of 1.41 to 1.46 at 15 parts by weight and 25 ° C. on the resin surface. Polystyrene resin particles.

The second invention is the foamable polystyrene-based resin particle according to the first invention, wherein the methylphenylpolysiloxane A contains a phenyl group in a proportion of 10 mol% to 40 mol%.

The third invention is the effervescent polystyrene system according to the first or second invention, wherein the methylphenyl polysiloxane B contains a phenyl group in an amount of 1 mol% to 20 mol%. Resin particles.

The fourth invention is characterized by a viscosity at 25 ° C. of the methylphenyl polysiloxane A is 100mm ² / s~6000mm ² / s, expandable polystyrene according to any one the first to the third invention Resin particles.

A fifth invention is characterized by a viscosity at 25 ° C. of the methylphenyl polysiloxane B is 100mm ² / s~4000mm ² / s, expandable polystyrene according to any one the first to fourth invention Resin particles.

A sixth invention is a polystyrene-based resin pre-expanded particle, which is obtained by foaming the foamable polystyrene-based resin particles according to any one of the first to fifth inventions.

The seventh invention is a polystyrene-based resin foam, which is obtained by in-mold molding of the polystyrene-based resin pre-foamed particles according to the sixth invention.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain foamable polystyrene-based resin particles suitable for obtaining a molded product having good fusion properties and surface properties while suppressing powder peeling and preventing blocking.

In the present invention, methylphenylpolysiloxane having a refractive index of 1.47 to 1.60 at 25 ° C. is represented as methylphenylpolysiloxane A, and methylphenylpolysiloxane having a refractive index of 1.41 to 1.46 at 25 ° C. Siloxane is represented as methylphenylpolysiloxane B.

In the present invention, when the foamable polystyrene resin particles are 100 parts by weight, the methylphenyl polysiloxane A is 0.03 parts by weight to 0.15 parts by weight, and the methylphenyl polysiloxane B is 0.01 parts by weight or more. It is characterized in that 0.06 part by weight is applied to the resin surface. Further, since a good molded product can be obtained, the amount of methylphenylpolysiloxane A is preferably 0.05 parts by weight to 0.10 parts by weight. When the amount of methylphenylpolysiloxane A applied is less than 0.03 parts by weight, the meltability of the molded product deteriorates. If it exceeds 0.15 parts by weight, the surface property of the molded product deteriorates. Further, it is preferable that the amount of methylphenylpolysiloxane B is 0.02 parts by weight to 0.04 parts by weight because a good molded product can be obtained. When the amount of methylphenylpolysiloxane B applied is less than 0.01 parts by weight, blocking during prefoaming increases. If it exceeds 0.06 parts by weight, the meltability of the molded product deteriorates.

In the present invention, the proportion of methylphenylpolysiloxane A containing a phenyl group is preferably 10 mol% to 40 mol%. When the proportion of methylphenylpolysiloxane A containing a phenyl group is less than 10 mol%, the compatibility with polystyrene is lowered and the uniformity is lowered at the time of surface coating. On the other hand, if it exceeds 40 mol%, it acts as a strong plasticizer due to the high compatibility with polystyrene, and deteriorates the surface property of the molded product.

In the present invention, the proportion of methylphenylpolysiloxane B containing a phenyl group is preferably 1 mol% to 20 mol%. When the proportion of the phenyl group of methylphenylpolysiloxane B is less than 1 mol%, the compatibility with polystyrene is lowered and the uniformity is lowered at the time of surface coating. If it exceeds 20 mol%, the blocking suppressing effect is reduced.

The refractive index of methylphenylpolysiloxane in the present invention depends on the content of phenyl groups. As the content of phenyl groups increases, the refractive index increases. When the refractive index of methylphenylpolysiloxane is less than 1.41, the content of phenyl groups is low, the compatibility with polystyrene is lowered, and the uniformity is lowered during surface coating. When the refractive index of methylphenylpolysiloxane exceeds 1.60, it acts as a strong plasticizer due to the high content of phenyl groups and high compatibility with polystyrene, which deteriorates the surface properties of the molded product.

The present invention is preferably viscous at 25 ° C. of methylphenyl polysiloxane A is 100mm ² / s~6000mm ² / s. When the viscosity of methylphenylpolysiloxane A at 25 ° C. is less than 100 mm ² / s, the characteristics as a siloxane are not sufficiently exhibited. If it exceeds 6000 mm ² / s, it does not sufficiently penetrate the particles due to its large molecular weight.

The present invention is preferably viscous at 25 ° C. of methylphenyl polysiloxane B is 100mm ² / s~4000mm ² / s. When the viscosity of methylphenylpolysiloxane B at 25 ° C. is less than 100 mm ² / s, the characteristics as a siloxane are not sufficiently exhibited. If it exceeds 4000 mm ² / s, it does not sufficiently penetrate the particles due to its large molecular weight.

The methylphenyl polysiloxane of the present invention is preferably a polysiloxane having a structure represented by the general formula (1).

Me of the methylphenylpolysiloxane represented by the general formula (1) represents a methyl group, and Ph represents a phenyl group. Further, m and n of the repeating unit are arbitrary natural numbers (1, 2, 3, etc.). The methylphenylpolysiloxane represented by the general formula (1) used in the present invention may be one in which a dimethyl moiety and a diphenyl moiety are randomly bonded, or may be a regularly arranged one.

The effervescent polystyrene-based resin particles of the present invention may further contain an inhibitor of blocking, a fusion accelerator and the like as an external additive and an adjunct, as long as the effects of the present invention are not impaired.

Specific examples of the external preparation and the attachment include fatty acid triglyceride such as triglyceride laurate, triglyceride stearate, and triglyceride linoleic acid, diglyceride laurate, diglyceride stearate, diglyceride linoleic acid, and monoglyceride laurate. Fatty acid monoglyceride such as monoglyceride stearate and monoglyceride linoleic acid, zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, zinc laurate, fatty acid metal salt such as calcium laurate, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether , Polyoxyethylene stearyl ether, polyoxyethylene laurate, polyoxyethylene palmitate, polyoxyethylene stearate, nonionic surfactants such as polyoxyethylene oleate and the like. These external additives may be used alone or in combination of two or more. Further, these external additives and attachments may be added to the water system when impregnated with the foaming agent, or may be added and coated after dehydration or drying, regardless of the coating method. A preferred coating method is a method of coating by attaching after drying and mixing and stirring.

In the present invention, since methylphenylpolysiloxane is a liquid, the powder does not peel off, the amount of steam used increases due to clogging of the slit of the mold during molding, and the granules are fed due to clogging of the pipe during granulation. Problems such as deterioration of sexuality do not occur.

The time required for applying the methylphenylpolysiloxane in the foamable polystyrene-based resin particles in the present invention and the stirring time may be any number of minutes as long as the time can be uniformly applied to the surface without uneven coating. Further, the charging time is preferably 1 to 150 seconds during stirring.

Examples of the mixing device used in the present invention include a super mixer, a nauta mixer, a universal mixer, a proshare mixer, an apex mixer, a henschel mixer, a ladyge mixer, a ribbon blender, a tumbler type blender, a henschel type mixer, and the like. Any type of mixer may be uniformly coated by adjusting the mixing time, etc. in consideration of the mixing ability, the coating amount of methylphenylpolysiloxane, and the viscosity. Sex polystyrene-based resin particles can be obtained.

The styrene-based foamable resin constituting the foamable polystyrene-based resin particles of the present invention is preferably a polymer containing 60 parts by weight or more of styrene as a monomer component, specifically, a styrene homopolymer or a styrene-ethylene-based polymer. Examples thereof include copolymers, styrene-butadiene-based copolymers, styrene-acrylonitrile-based copolymers, and styrene-acrylic acid ester-based copolymers.

Among these, the base resin constituting the foamable polystyrene-based resin particles may be obtained by copolymerizing a styrene-based monomer and an acrylic acid ester-based monomer.

Examples of the styrene-based raw material used for the foamable polystyrene-based resin particles of the present invention include styrene-based derivatives such as styrene, α-methylstyrene, paramethylstyrene, t-butylstyrene, and chlorostyrene. These styrene-based monomers may be used alone or in combination of two or more.

Examples of the acrylic acid ester-based monomer constituting the foamable polystyrene-based resin particles of the present invention include acrylic acid alkyl esters such as methyl acrylate and butyl acrylate. These acrylic acid ester-based monomers may be used alone or in combination of two or more.

Regarding the monomer composition of the base resin, when the seed suspension polymerization method is carried out as the polymerization method, the monomer composition in the resin particles as the seed is also reflected in the monomer composition.

The monomer component contained in the foamable polystyrene-based resin particles of the present invention is less than 0.3 parts by weight. The contained monomer component tends to volatilize from the foamed molded product obtained by foaming the foamable polystyrene-based resin particles, and particularly when the contained monomer component is 0.3 parts by weight or more, the medical field. Alternatively, it is not preferable for the field of packaging materials that come into direct contact with food, or for automobile and building components.

The amount of the monomer component contained can be controlled by the combination of the amount of the initiator used when polymerizing the polystyrene resin particles and the polymerization temperature. For example, the amount of the monomer component contained can be reduced by increasing the amount of the initiator used and increasing the polymerization temperature.

The foamable polystyrene-based resin particles of the present invention may contain a solvent and a plasticizer having a boiling point of 50 ° C. or higher as long as the effects of the present invention are not impaired.

Specific examples of solvents and plasticizers having a boiling point of 50 ° C. or higher include C6 or higher aliphatic hydrocarbons such as hexane and heptane, C6 and higher alicyclic hydrocarbons such as cyclohexane and cyclooctane, and diisobutyl adipate. Examples include dioctyl adipate, dibutyl sebacate, glycerin tristearate, glycerin tricaprylate, palm oil, palm oil, rapeseed oil and the like.

The content of the foaming agent in the foamable polystyrene-based resin particles in the present invention is preferably 3.0 parts by weight to 9.0 parts by weight with respect to 100 parts by weight of the foamable polystyrene-based resin particles. 3.5 parts by weight to 8.5 parts by weight is more preferable, and 4.0 parts by weight to 7.0 parts by weight is particularly preferable.

If the content of the foaming agent is less than 3.0 parts by weight, the pre-foaming time tends to be long, the fusion rate during molding tends to decrease, the manufacturing cost increases, and it is economically disadvantageous. When the content of the foaming agent is 9.0 parts by weight or more, the molded product tends to shrink and spoil the appearance of the molded product.

Examples of the effervescent agent used in the present invention include aliphatic hydrocarbons such as propane, butane and pentane, alicyclic hydrocarbons such as cyclobutane and cyclopentane, methyl chloride, dichlorodifluoromethane and dichlorotetrafluoroethane. Such as halogenated hydrocarbons can be mentioned. These foaming agents may be used alone or in combination of two or more. Among these foaming agents, butane is preferable because it has a good foaming power.

The amount of the foaming agent used in the present invention is preferably 3.0 parts by weight to 9.0 parts by weight, more preferably 6.0 parts by weight to 8.0 parts by weight, based on 100 parts by weight of the polystyrene resin particles.

The content of the foaming agent in the polystyrene-based prefoamed resin particles in the present invention is preferably 2.0 parts by weight to 7.0 parts by weight, preferably 3.0 parts by weight or more, based on 100 parts by weight of the polystyrene-based prefoamed resin particles. 4.3 parts by weight is more preferable.

If the content of the foaming agent is less than 2.0 parts by weight, the preliminary foaming time tends to be long, the fusion rate during molding tends to decrease, the manufacturing cost increases, and it is economically disadvantageous. When the content of the foaming agent exceeds 7.0 parts by weight, the molded product tends to shrink and spoil the appearance of the molded product.

In the foamable polystyrene-based resin particles of the present invention, the average chord length of bubbles on the cut surface of the foamed molded product obtained from the foamable polystyrene-based resin particles is 50 μm or more and less than 200 μm. It is preferably 80 μm or more and less than 120 μm.

If the average chord length is less than 50 μm, the film thickness of the cells constituting the foam tends to be thin, and the internal fusion and surface properties tend to decrease. When the average chord length is 200 μm or more, the fracture point displacement of the breaking strength (for example, the bending strength of JIS A9511 and the bottom split strength of the box-shaped molded body) becomes short, and the molded body tends to be brittle.

The average chord length of the bubbles on the cut surface of the foam can be controlled by the amount of nucleating agent. For example, increasing the amount of nucleating agent reduces the average chord length, and decreasing the amount of nucleating agent increases the average chord length.

The foamable polystyrene-based resin particles of the present invention may contain a flame retardant, a flame retardant aid, etc. as additives as long as the effects of the present invention are not impaired.

As the flame retardant and the flame retardant aid contained in the present invention, known and commonly used ones can be used. Specific examples of the flame retardant include halogenated aliphatic hydrocarbon compounds such as hexabromocyclododecane, tetrabromobutane, and hexabromocyclohexane, tetrabromobisphenol A, tetrabromobisphenol F, 2,4,6-tri. Brominated phenols such as bromophenol, tetrabromobisphenol A-bis (2,3-dibromopropyl ether), tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol A- Brominated phenol derivatives such as diglycidyl ether, 2,2-bis [4'(2 ", 3" -dibromoalkoxy) -3', 5'-dibromophenyl] -propane, brominated styrene-butadiene block copolymer , Brominated random styrene / butadiene copolymer, brominated butadiene / vinyl aromatic hydrocarbon copolymer such as brominated styrene / butadiene graph and copolymer (for example, EMERALD3000 manufactured by Chemtura, or Special Table 2009-516019. ) Etc., which are disclosed in the Gazette. These flame retardants may be used alone or in combination of two or more.

As a specific example of the flame retardant aid, for example, an initiator such as cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane may be used. Good.

The foamable polystyrene-based resin particles of the present invention are pre-foamed and then heat-foamed to obtain a foamed molded product.

As the pre-foaming method, for example, a usual method such as heating with steam or the like to foam using a cylindrical pre-foaming device can be adopted.

As a method for foam-molding the pre-foamed particles, for example, a usual method such as a so-called in-mold foam-molding method in which a pre-foamed particle is filled in a mold and a foamed molded product is obtained by blowing steam or the like to heat the mold. Can be adopted.

Examples and comparative examples are given below, but the present invention is not limited thereto.

The measurement and evaluation method was carried out as follows.

<Measurement of powder peeling amount>
Using a blower, 500 kg of foamable polystyrene resin particles were fed. The weight of the filter closest to the blower before and after grain feeding was measured, and the difference was defined as the peeling amount X [g]. Further, the total amount of the powder external additive applied to the foamable polystyrene resin particles was defined as Y [g], and the peeling rate [%] was calculated by the following formula.
Peeling rate [%] = X [g] / Y [g] x 100.

<Preliminary foaming>
Expandable polystyrene-based resin particles were put into a pre-foaming machine with a stirrer and foamed by heating with steam to obtain foamable polystyrene-based resin particles having an apparent magnification of 5 to 80 times. For blocking, the crusher is stopped when the pre-foamed particles are dispensed, the pre-foamed particles that are not blocked are sent through a net with a mesh opening of 1 cm, and then collected and weighed, and the ratio of the recovered pre-foamed particles to the input resin is weighed. The department evaluated it according to the following criteria.
⊚: The blocking rate is 0.10% or less.
◯: The blocking rate is more than 0.10% and 0.15% or less.
Δ: The blocking rate is more than 0.15% and 0.20% or less.
X: The blocking rate exceeds 0.20%.

<Evaluation of moldability>
Using a molding machine [made by Daisen, KR-57], a box-shaped mold having a bottom thickness of 30 mm, a side thickness of 25 mm, a length of 550 mm, a width of 350 mm, and a height of 120 mm is filled into a box-shaped mold, and the vapor pressure is blown to 0. In-mold molding was performed under molding conditions varied within the range of 3 to 0.8 kgf / cm ² , and a box-shaped foam molded product was obtained.

The obtained thermoplastic resin foam was dried at room temperature for 24 hours, and then the following evaluation was carried out. Table 1 shows the evaluation results of the cooling time, the fusion property and the surface property at a vapor pressure of 0.50 kgf / cm ² .

(1) Evaluation of fusion property The obtained thermoplastic resin foam was fractured, the fracture surface was observed, and the rate at which the particles were fractured, not the particle interface, was determined and fused according to the following criteria. The sex was judged.
⊚: The rate of particle breakage is 90% or more.
◯: The rate of particle breakage is 80% or more and less than 90%.
Δ: The rate of particle breakage is 70% or more and less than 80%.
X: The rate of particle breakage is less than 70%.
(2) Evaluation of surface properties The surface condition of the obtained thermoplastic resin foam was visually observed, and the surface properties were evaluated according to the following criteria.
◎: Very beautiful with no melting of the surface and no intergrains.
◯: The surface is melted and there are few intergrains, and it is beautiful.
Δ: The surface is melted and there are intergrains, and the appearance is slightly poor.
X: Surface melts, there are many grains, and the appearance is poor.

(Example 1)
<Coating of polysiloxane on effervescent polystyrene resin particles>
Expandable polystyrene resin particles (product name: Kaneka SG: Kaneka Corporation, foaming agent amount: 3.5 to 8.5 parts by weight) were used as the base resin to which the two types of methylphenylpolysiloxane were applied.

The effervescent polystyrene-based resin particles were sieved, and the effervescent polystyrene-based resin particles having a particle diameter of 0.6 mm to 1.12 mm were separated.

Methylphenylpolysiloxane A (product name: KF-) exhibiting a refractive index of 1.47 to 1.60 at 25 ° C. in 100 parts by weight of the foamable polystyrene-based resin particles previously charged into a Nauta mixer [manufactured by Hosokawa Micron]. 54, refractive index 1.505 (25 degrees), viscosity 400 mm ² / s (25 degrees): Shin-Etsu Chemical) 0.040 parts by weight was added over 120 seconds, blended for 15 minutes, and then the refractive index at 25 ° C was Methylphenylpolysiloxane B showing 1.41-1.46 (product name KF-50-1000, refractive index 1.425 (25 degrees), viscosity 1000 mm ² / s (25 degrees): Shin-Etsu Chemical) 0.030 weight The parts were added over 120 seconds and blended for 15 minutes to obtain effervescent polystyrene resin particles.

<Manufacturing of preliminary foam particles>
The obtained effervescent polystyrene-based resin particles were pre-foamed at a bulk magnification of 65 times under the condition of a blown vapor pressure of 0.5 kgf / cm ² using a pressure type pre-foaming machine [manufactured by Daikai Kogyo, BHP]. .. At this time, air was cut into the blown steam to adjust the blown steam temperature. Then, it was left at room temperature for one day to cure and dry.

<Manufacturing of in-mold foam molded product>
Using a molding machine [Daisen, KR-57], the obtained polystyrene-based resin pre-foamed particles are used to form a box-shaped gold having a bottom thickness of 30 mm, a side thickness of 25 mm, a length of 550 mm, a width of 350 mm, and a height of 120 mm. The mold was filled and molded in the mold under the molding conditions of a blown vapor pressure of 0.3 to 0.8 kgf / cm ² , to obtain a box-shaped foam molded product.

Evaluation was performed using the obtained foamable polystyrene-based resin particles and the foamed molded product, and the results are shown in Table 1.

(Example 2)
In <Applying Polysiloxane to Expandable Polystyrene Resin Particles>, the amount of silicone-based external additive applied was 0.080 parts by weight of Methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.) and methylphenylpoly. Siloxane B (product name KF-50-1000: Shin-Etsu Chemical Co., Ltd.) Except for the change to 0.015 parts by weight, the same operation as in Example 1 was carried out to obtain foamable polystyrene resin particles, pre-foamed particles, and in-mold foam molded product. Got The evaluation results are shown in Table 1.

(Example 3)
In <Application of polysiloxane to foamable polystyrene-based resin particles>, except that the amount of silicone-based external additive applied was changed to 0.080 parts by weight of methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical). By the same operation as in Example 1, expandable polystyrene resin particles, pre-expanded particles, and in-mold foam molded product were obtained. The evaluation results are shown in Table 1.

(Example 4)
In <Applying Polysiloxane to Expandable Polystyrene Resin Particles>, the amount of silicone-based external additive applied was 0.080 parts by weight of Methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.) and methylphenylpoly. Siloxane B (product name KF-50-1000: Shin-Etsu Chemical Co., Ltd.) Except for the change to 0.050 parts by weight, the same operation as in Example 1 was carried out to obtain foamable polystyrene resin particles, pre-foamed particles, and in-mold foam molded product. Got The evaluation results are shown in Table 1.

(Example 5)
In <Application of polysiloxane to foamable polystyrene-based resin particles>, except that the amount of silicone-based external additive applied was changed to 0.130 parts by weight of methylphenyl polysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.). By the same operation as in Example 1, expandable polystyrene resin particles, pre-expanded particles, and in-mold foam molded product were obtained. The evaluation results are shown in Table 1.

(Example 6)
In <Application of polysiloxane to foamable polystyrene resin particles>, the type and amount of silicone-based external additive were changed to 0.080 parts by weight of methylphenylpolysiloxane A (product name KF-54HV: Shin-Etsu Chemical). The same operation as in Example 1 was carried out to obtain foamable polystyrene-based resin particles, pre-foamed particles, and an in-mold foamed molded product. The evaluation results are shown in Table 1.

(Example 7)
In <Coating of polysiloxane to foamable polystyrene-based resin particles>, the type and amount of silicone-based external additive were set to 0.080 parts by weight of methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.). Examples except that methylphenylpolysiloxane B (product name KF-50-300, refractive index 1.425 (25 degrees), viscosity 300 mm ² / s (25 degrees): Shin-Etsu Chemical) was changed to 0.030 parts by weight. By the same operation as in No. 1, foamable polystyrene resin particles, pre-foamed particles, and in-mold foamed molded product were obtained. The evaluation results are shown in Table 1.

(Example 8)
In <Coating of polysiloxane to foamable polystyrene-based resin particles>, the type and amount of silicone-based external additive were set to 0.080 parts by weight of methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.). Examples except that methylphenylpolysiloxane B (product name KF-50-3000, refractive index 1.425 (25 degrees), viscosity 3000 mm ² / s (25 degrees): Shin-Etsu Chemical) was changed to 0.030 parts by weight. By the same operation as in No. 1, foamable polystyrene resin particles, pre-foamed particles, and in-mold foamed molded product were obtained. The evaluation results are shown in Table 1.

(Example 9)
In <Application of polysiloxane to foamable polystyrene-based resin particles>, the type and amount of silicone-based external additive are set to methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical (0.050 parts), product). Name KF-54HV, refractive index 1.501 (25 degrees), viscosity 5000 mm ² / s (25 degrees): Shin-Etsu Chemical (0.030 parts)) Same as Example 1 except that it was changed to 0.080 parts by weight. By the above operation, foamable polystyrene resin particles, pre-foamed particles, and in-mold foamed molded product were obtained. The evaluation results are shown in Table 1.

(Example 10)
In <Applying Polysiloxane to Expandable Polystyrene Resin Particles>, the amount of silicone-based external additive applied was 0.080 parts by weight of Methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.) and methylphenylpoly. Siloxane B (Product name KF-50-1000: Shin-Etsu Chemical Co., Ltd.) Effervescent polystyrene-based by the same operation as in Example 1 except that it was changed to 0.020 parts by weight and 0.100 parts by weight of zinc stearate was added. Resin particles, prefoamed particles, and in-mold foamed molded product were obtained. The evaluation results are shown in Table 1.

(Comparative Example 1)
In <Application of polysiloxane to foamable polystyrene resin particles>, except that the amount of silicone-based external additive applied was changed to 0.020 parts by weight of methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical). By the same operation as in Example 1, expandable polystyrene resin particles, pre-expanded particles, and in-mold foam molded product were obtained. The evaluation results are shown in Table 1.

(Comparative Example 2)
In <Applying Polysiloxane to Expandable Polystyrene Resin Particles>, the amount of silicone-based external additive applied was 0.080 parts by weight of Methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.) and methylphenylpoly. Siloxane B (product name KF-50-1000: Shin-Etsu Chemical Co., Ltd.) Except for the change to 0.005 parts by weight, the same operation as in Example 1 was carried out to obtain foamable polystyrene resin particles, pre-foamed particles, and in-mold foam molded product. Got The evaluation results are shown in Table 1.

(Comparative Example 3)
In <Applying Polysiloxane to Expandable Polystyrene Resin Particles>, the amount of silicone-based external additive applied was 0.080 parts by weight of Methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.) and methylphenylpoly. Siloxane B (Product name KF-50-1000: Shin-Etsu Chemical Co., Ltd.) By the same operation as in Example 1 except that it was changed to 0.100 parts by weight, foamable polystyrene resin particles, pre-foamed particles, and in-mold foamed molded product. Got The evaluation results are shown in Table 1.

(Comparative Example 4)
In <Application of polysiloxane to foamable polystyrene-based resin particles>, except that the amount of silicone-based external additive applied was changed to 0.200 parts by weight of methylphenyl polysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.). By the same operation as in Example 1, foamable polystyrene resin particles, pre-foamed particles, and in-mold foam molded product were obtained. The evaluation results are shown in Table 1.

(Comparative Example 5)
In <Application of polysiloxane to foamable polystyrene-based resin particles>, the type and amount of silicone-based external additive were set to 0.100 parts by weight of methylphenylpolysiloxane A (product name KF-54: Shin-Etsu Chemical Co., Ltd.). Dimethylpolysiloxane (product name KF-96-500, refractive index 1.403 (25 degrees), viscosity 500 mm ² / s (25 degrees): Shin-Etsu Chemical) Except for changing to 0.050 parts by weight, as in Example 1. By the same operation, foamable polystyrene resin particles, pre-foamed particles, and in-mold foamed molded product were obtained. The evaluation results are shown in Table 1.

(Comparative Example 6)
In <application of polysiloxane to effervescent polystyrene-based resin particles>, 0.200 parts by weight of zinc stearate and caster wax (hydroxystearic acid triglyceride) were added as external additives (methylphenylpolysiloxane A and B). Expandable polystyrene-based resin particles, pre-expanded particles, and in-mold foam molded article were obtained by the same operation as in Example 1 except that the weight was changed to 050 parts by weight. The evaluation results are shown in Table 1. In (Comparative Example 6), blocking can be suppressed and good physical characteristics of the molded product can be obtained. On the other hand, since a powder external additive is used in this formulation, the powder peels off, resulting in an increase in the amount of steam used due to clogging of the slits in the mold during actual manufacturing, and piping during grain feeding. Problems such as deterioration of fluidity due to clogging may occur.

Claims (5)

0.03 parts by weight to 0.15 parts by weight of methylphenylpolysiloxane A having a refractive index of 1.501 to 1.505 at 25 ° C. with respect to 100 parts by weight of foamable polystyrene resin particles, and a refractive index at 25 ° C. Foamable polystyrene-based resin particles, characterized in that 0.01 parts by weight to 0.06 parts by weight of methylphenylpolysiloxane B showing 1.425 is applied to the resin surface. Characterized in that said viscosity is 100mm ² / s~6000mm ² / s at 25 ° C. of methylphenyl polysiloxane A, expandable polystyrene resin particles according to claim 1. The viscosity of the methylphenylpolysiloxane B at 25 ° C. is 100 mm ² / s to 400.
The effervescent polystyrene-based resin particles according to claim 1 or 2 , wherein the particles are 0 mm ² / s. The polystyrene-based resin pre-expanded particles, which are obtained by foaming the foamable polystyrene-based resin particles according to any one of claims 1 to 3 . A polystyrene-based resin foam, which is obtained by in-mold molding of the polystyrene-based resin pre-foamed particles according to claim 4 .