JP5172811B2 - Expandable styrene resin particles, method for producing the resin particles, and styrene resin foam particle molded body - Google Patents

Description

  The present invention relates to a foamable styrene resin particle, a method for producing the resin particle, and a styrene resin foam particle molding obtained by in-mold molding a styrene resin foam particle obtained by foaming the foamable styrene resin particle. About the body.

Styrenic resin foam particles obtained by in-mold molding of styrene resin foam particles obtained from expandable styrene resin particles are used in heat insulation materials for houses and cold storage boxes due to their excellent heat insulation performance. .
However, since the heat-resistant temperature of styrene resin is 70 to 80 ° C., it is applicable to applications that require heat resistance such as hot water tanks for electric water heaters, heat insulation for hot water piping, heat insulation for roofs, and automobile members. There are cases where it is not possible.
Moreover, it is calculated | required that heat insulating materials, such as a housing facility, have self-extinguishing property. Furthermore, in recent years, in order to cope with chemical hypersensitivity, so-called sick house syndrome, a heat insulating material with a small residual amount of volatile organic compounds, particularly volatile aromatic hydrocarbons, has been demanded.

Patent Document 1 discloses an expandable styrene resin particle in which a bromine-based organic compound is blended as a flame retardant and an expanded molded article excellent in self-extinguishing properties. Patent Document 2 discloses a styrene resin foam having improved heat resistance using a mixed resin containing a styrene resin and a polyphenylene ether resin as a base resin. Patent Document 3 describes expandable resin particles containing an organic solvent and a volatile foaming agent for a resin containing a styrene-based resin and a polyphenylene ether-based resin. It is disclosed that the strength is improved. Patent Document 4 discloses that low-density particles of a resin composition containing a polyphenylene ether resin and a styrene resin have good thermal properties and mechanical properties.
Furthermore, Patent Document 5 discloses an extruded foam in which a phosphate ester is added as a flame retardant to impart a self-extinguishing property to a thermoplastic resin composed of a styrene resin and a polyphenylene ether resin.

Japanese Patent Laid-Open No. 2007-9018 JP 52-101268 A Japanese Patent No. 30640405 JP-A 63-150337 JP 2003-327734 A

  However, although the foam described in Patent Document 1 has self-extinguishing properties, it has a problem in heat resistance. In addition, the foams described in Patent Documents 2 to 4 are improved in heat resistance and strength by blending a polyphenylene ether resin, but are not self-extinguishing. In addition, there has been a problem that aromatic hydrocarbons added as a dispersion medium when the styrene resin particles are impregnated with a foaming agent remain in the foam. As for the foam described in Patent Document 5, a phosphate ester is added as a flame retardant to a thermoplastic resin composed of a styrene resin and a polyphenylene ether resin. In order to obtain fire extinguishing properties, a large amount of polyphenylene ether resin and phosphate ester had to be contained. On the other hand, since this phosphate ester also acts as a plasticizer, when a large amount of phosphate ester is added, the heat resistance is lowered, and a foam having heat resistance and self-extinguishing properties cannot be obtained. In particular, in order to obtain a foamed particle molded body having heat resistance and self-extinguishing properties, not only the foamability of the resin particles, but also the in-mold moldability of the foamed particles obtained by foaming the resin particles, and the stability of the obtained foamed body Conventionally, styrenic resin expanded particle molded bodies having excellent heat resistance and self-extinguishing properties have not been obtained, and development thereof is desired.

  In view of such conventional problems, the present invention provides a foamed particle molded body having excellent strength and heat resistance and having self-extinguishing properties that pass the combustion test (Method A) of JIS A 9511 (2006). Expandable styrene resin particles that can be produced, a method for producing the same, and a styrene resin foam particle molded body obtained by foaming styrene resin foam particles obtained by foaming the expandable styrene resin particles are provided. For the purpose.

The present invention has been made against the background described above, and in order to obtain expandable styrene resin particles from which a styrene resin expanded particle molded article having excellent heat resistance and self-extinguishing properties can be obtained, the expandable styrene As a result of examining the foamability of the resin-based resin particles and the in-mold moldability of the foamed particles obtained by foaming the foamable styrene-based resin particles, polystyrene resin, polyphenylene ether resin, specific weight average molecular weight as a flame retardant It has been found that expandable styrenic resin particles composed of a brominated epoxy resin having a resin composition and a resin composition each containing a specific amount of antimony oxide as a flame retardant aid can solve the above problems, and have completed the present invention.
That is, the present invention is an invention having the following [1] to [4].
[1] From a resin composition containing a styrene resin (A), a polyphenylene ether resin (B), a brominated epoxy resin (C) having a weight average molecular weight of 10,000 to 80,000, and antimony oxide (D) Expandable styrene resin particles impregnated with a foaming agent, wherein the resin composition comprises 15 to 50 parts by weight of polyphenylene ether resin (B) and 100 parts by weight of styrene resin (A), bromine Expandable styrenic resin particles comprising 10 to 30 parts by weight of an epoxy resin (C) and 1 to 15 parts by weight of antimony oxide (D).
[2] The expandable styrenic resin particles according to [1] above, wherein the brominated epoxy resin (C) has an epoxy equivalent of 20,000 g / eq or more.
[3] Styrenic resin foamed particle molding, wherein the styrene resin foamed particles obtained by foaming the expandable styrene resin particles according to [1] or [2] are molded in-mold. body.
[4] The polyphenylene ether resin (B) is 10 to 50 parts by weight and the weight average molecular weight is 10,000 to 80,000 with respect to 100 parts by weight of the styrene resin (A) and the styrene resin (A). A resin composition obtained by blending 10 to 30 parts by weight of a brominated epoxy resin (C) and 1 to 15 parts by weight of antimony oxide (D) is melt-kneaded and extruded in an extruder, and then cut. A styrenic resin particle is obtained, the styrenic resin particle is dispersed in an aqueous suspension in a closed container, and the styrenic resin particle is impregnated with a foaming agent. Production method.

In the expandable styrene resin particles according to [1], the resin composition constituting the expandable styrene resin particles is a styrene resin (A), a polyphenylene ether resin (B), and a brominated epoxy resin ( C) and antimony oxide (D) are contained in specific amounts. By using the expandable resin particles made of the resin composition, it is possible to obtain styrene resin expanded particles and styrene resin expanded particle molded articles having both heat resistance and self-extinguishing properties.
The expandable styrenic resin particles described in [2] above are particularly those in which the shape of the expandable resin particles is closer to a spherical shape. The moldability when molding in-mold is improved.
The molded article of styrene resin expanded particles according to [3] is obtained by in-mold molding styrene resin expanded particles obtained by expanding the expandable styrene resin particles according to [1] or [2]. It is a foamed particle molded body having excellent heat resistance and self-extinguishing properties. In addition, by combining heat resistance and self-extinguishing properties, it can be used for applications such as hot water tanks for electric water heaters, insulation materials for hot water piping, insulation materials for roofs, and automobile parts, which were difficult to use in the past. be able to.
In the method for producing expandable styrene resin particles according to [4] above, the styrene resin particles are dispersed in an aqueous suspension in an airtight container and impregnated with a foaming agent, so that volatility is achieved. Even without adding an aromatic hydrocarbon, expandable styrene resin particles having self-extinguishing properties and heat resistance can be stably produced.

Hereinafter, the expandable styrene resin particles in the present invention may be simply referred to as expandable resin particles, the styrene resin expandable particles may be simply referred to as expandable particles, and the styrene resin expandable particle molded body is simply formed into expanded particle. It may also be called a body or a molded body.
Hereinafter, [1] expandable styrene resin particles, [2] production method of expandable styrene resin particles, [3] styrene resin foam particles, and [4] molded styrene resin foam particles of the present invention will be described. To do.
[1] Expandable styrene resin particles The resin composition constituting the expandable styrene resin particles of the present invention is a polyphenylene ether resin with respect to 100 parts by weight of the styrene resin (A) and the styrene resin (A). (B) It contains 10 to 50 parts by weight, 10 to 30 parts by weight of brominated epoxy resin (C), and 1 to 15 parts by weight of antimony oxide (D).

(1) Styrenic resin (A)
The styrene resin (A) of the present invention includes styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-methoxystyrene, Fragrances such as pn-butylstyrene, pt-butylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, 2,4,6-tribromostyrene, styrenesulfonic acid, sodium styrenesulfonate It is a styrene resin obtained by polymerizing a group vinyl monomer. The styrenic resin (A) may be the above aromatic vinyl monomer alone, or a mixture of two or more of these monomers, and a mixture of two or more resins obtained by polymerization from the monomers. Things can be used.

Alternatively, a styrene resin copolymerized with a vinyl monomer copolymerizable with an aromatic vinyl monomer may be used. Examples of such vinyl monomers include acrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate Methacrylic acid esters such as 2-ethylhexyl methacrylate; vinyl compounds containing hydroxyl groups such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate; vinyl compounds containing nitrile groups such as acrylonitrile and methacrylonitrile Organic vinyl compounds such as vinyl acetate and vinyl propionate; olefin compounds such as ethylene, propylene, 1-butene and 2-butene; butadiene, Vinyl chloride, vinyl halide compounds of the vinyl bromide and the like; Puren, diene compound chloroprene, vinylidene halide compounds such as vinylidene chloride; N- phenylmaleimide, maleimide compounds such as N- methyl maleimide.
From the viewpoint of production cost and foaming properties when obtaining foamed particles from the foamable resin particles, it is preferable to use a styrene resin mainly composed of styrene, and the styrene resin (A) contains a styrene component. It is preferable to contain 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more.

The molecular weight of the styrenic resin (A) of the present invention is preferably a weight average molecular weight (Mw) in the range of 150,000 to 350,000. Within the above range, the foamed particles obtained from the foamable resin particles have good foamability, and a foamed particle molded body having a high expansion ratio can be obtained, and the foamed particles are fused to each other during in-mold molding. It is easy and the strength of the obtained expanded foam molded body is improved. The weight average molecular weight (Mw) is preferably 150,000 to 250,000.
The weight average molecular weight, number average molecular weight, and Z average molecular weight were measured by GPC (gel permeation chromatograph) method by dissolving 10 mg of styrene resin in 10 mL of THF (tetrahydrofuran) and calibrated with standard polystyrene. Value. The above GPC analysis was performed using equipment: Tosoh Corporation, SC-8020 type, column: Showa Denko Co., Ltd., Shodex AC-80M connected in series, column temperature: 40 ° C., flow rate: 1.0 ml. / Min. Detector: Tosoh Co., Ltd., UV-visible light detector UV-8020 type can be used for measurement.

(2) Polyphenylene ether resin (B)
The polyphenylene ether resin (B) of the present invention is a polymer represented by the following general formula. In the following general formula, R ₁ , R ₂ , R ₃ , and R ₄ each represent a hydrogen atom, a halogen atom, and an alkyl group having 1 to 4 carbon atoms, and these may be the same or different. Also good. n is an integer indicating the degree of polymerization.

  Examples of the polyphenylene ether resin (B) include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, and poly (2,6-dipropyl). -1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, poly (2-ethyl) -6-propyl-1,4-phenylene) ether. A polyphenylene ether resin obtained by graft polymerization of an aromatic vinyl monomer can also be used. The degree of polymerization is usually 10 to 5000.

  Content of polyphenylene ether resin (B) in the resin composition which comprises the expandable resin particle | grains of this invention is 10-50 weight part with respect to 100 weight part of styrene resin (A). When the content is too small, the foamed particle molded body obtained from the foamable resin particles may not have sufficient heat resistance. On the other hand, when there is too much said content, there exists a possibility that the foamability and molding processability of the foamed particle obtained from the said foamable resin particle may fall. The content is preferably 15 to 45 parts by weight, and more preferably 20 to 40 parts by weight.

(3) Brominated epoxy resin (C)
The brominated epoxy resin (C) of the present invention is obtained by adding bromine to an epoxy resin. For example, brominated bisphenol A type epoxy resin, brominated novolak type epoxy resin and the like can be mentioned. Among these, brominated bisphenol A type epoxy resin is obtained by reacting brominated bisphenol A such as tetrabromobisphenol A and epichlorohydrin, and is a polymer represented by the following general formula, where n is the degree of polymerization. An integer representing In the present invention, in order to obtain heat resistance, the polyphenylene ether resin (B) is contained in the resin composition constituting the expandable resin particles. In general, polyphenylene ether resins need to have a higher processing temperature. Therefore, when the resin composition is melt-kneaded, the melting temperature is higher than when the polyphenylene ether resin is not included. For this reason, the flame retardant blended in the resin composition also requires heat resistance. Further, in addition to the above viewpoints, the present inventors have studied the foamability of the foamable resin particles and the moldability of the foamed particles, and found that a brominated epoxy resin is suitable as the flame retardant. Furthermore, what sealed some brominated epoxy groups, such as a tribromophenol, can also be used.

The brominated epoxy resin (C) has a weight average molecular weight of 10,000 to 80,000.
If the weight average molecular weight is too small, there is a risk of thermal decomposition when the styrene resin particles are melt-kneaded, and the resulting styrene resin particle foam has insufficient heat resistance and thermal stability. There is a fear. On the other hand, when the weight average molecular weight is too large, the expandable styrene resin particles may be flattened due to the influence of residual strain during granulation. In addition, the foamed particles obtained from the flattened foamable resin particles may deteriorate the filling property into the mold, the foamability, and the moldability during in-mold molding. The weight average molecular weight is preferably 15,000 to 60,000, more preferably 20,000 to 50,000, and still more preferably 20,000 to 40,000.
In addition, the said weight average molecular weight melt | dissolves brominated epoxy resin in tetrahydrofuran similarly to the case where the weight average molecular weight of styrene resin (A) is measured, it measures by GPC (gel permeation chromatography) method, and is standard. It is a value calibrated with polystyrene.

The brominated epoxy resin (C) preferably has an epoxy equivalent of 20,000 g / eq or more. When the epoxy equivalent is 20,000 g / eq or more, the foamable styrenic resin particles are not further flattened, and the moldability during molding of the foamed particles obtained from the foamable resin particles is improved. Further, the moldability becomes better. If the epoxy equivalent is too low, the terminal epoxy group of the brominated epoxy resin and the terminal phenol group of the polyphenylene ether resin are bonded to each other when the foamable resin particles are produced and melt kneaded in the extruder. It is estimated that flattening of the expandable resin particles is likely to occur because the resin viscosity increases and the residual strain increases. The epoxy equivalent is more preferably 30,000 g / eq or more. The upper limit of the epoxy equivalent is not particularly limited from the viewpoint of preventing flattening, but is generally 100,000 g / eq.
The epoxy equivalent (g / eq) represents the mass of the brominated epoxy resin containing 1 equivalent of an epoxy group, and the epoxy equivalent increases as the terminal epoxy group of the brominated epoxy resin decreases. The epoxy equivalent can be adjusted by sealing the terminal epoxy group of the brominated epoxy resin with phenols, alcohols, carboxylic acids, amines and the like.

  The epoxy equivalent of the brominated epoxy resin of the present invention can be measured by perchloric acid-tetraethylammonium bromide titration method according to JIS K 7236 (2001). Specifically, about 1 g of brominated epoxy resin is weighed in a 50 milliliter (mL) Erlenmeyer flask to a weighing accuracy of 0.1 mg, added with 20 mL of chloroform, and dissolved by stirring with a magnetic stirrer. To this solution, 2 mL of acetic acid, 1 mL of tetraethylammonium bromide acetic acid solution (a solution in which 25 g of tetraethylammonium bromide was dissolved in 100 mL of acetic acid), and a crystal violet indicator solution (a solution in which 1 mg of crystal violet was dissolved in 10 mL of acetic acid) Two to three drops are added, titrated with a commercially available 0.1 mol / L perchloric acid acetic acid standard solution, and the end point of the titration is determined by calculating the epoxy equivalent according to the following equation as the time when the color begins to turn green.

Epoxy equivalent _{= (1000 × m) / [} (V 1 -V 0) × (1- (t-t s) / 1000) × c]
The symbols in the above formula are as follows.
m: Mass of the sample (g)
V ₁ : Amount of perchloric acid acetic acid solution consumed for titration to the end point in the blank test (mL)
V ₀ : Amount of perchloric acid acetic acid solution consumed for titration to end point in sample measurement (mL)
t: Temperature of the perchloric acid acetic acid solution during the test and blank test (° C)
t _s ; temperature of perchloric acid acetic acid solution during standardization (° C)
c: Concentration of the perchloric acid acetic acid solution (usually 0.1 mol / L)

  Content of brominated epoxy resin (C) in the resin composition which comprises the expandable resin particle | grains of this invention is 10-30 weight part with respect to 100 weight part of styrene resin (A). When the content is too small, the self-extinguishing property of the foamed particle molded body obtained from the foamable resin particles may be insufficient. On the other hand, when the content is too large, physical properties such as strength may be insufficient, and the manufacturing cost increases and industrial merit cannot be obtained.

(4) Antimony oxide (D)
The resin composition constituting the expandable styrene resin particles of the present invention contains antimony oxide (D) such as antimony trioxide and antimony pentoxide as a flame retardant aid. Content in the resin composition which comprises the expandable resin particle of antimony oxide (D) is 1-15 weight part with respect to 100 weight part of styrene resin (A).
When there is too little said antimony oxide (D), there exists a possibility that the self-extinguishing property of the foaming particle molded object obtained from the said expandable styrene-type resin particle may become inadequate. On the other hand, when there is too much antimony oxide (D), since there are many inorganic components, foamability and molding processability fall, and the foamable resin particle which can obtain the foamed particle molded object of a high expansion ratio May not be obtained.
In the present invention, when a specific amount of brominated epoxy resin (C) and antimony oxide (D) are used in combination, particularly, high self-extinguishing properties are obtained.

(5) Other polymer components The resin composition constituting the expandable resin particles of the present invention can contain other polymer components by kneading means such as an extruder within a range not impairing the effects of the present invention. .
Examples of the other polymer component include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear ultra-low-density polyethylene, polypropylene, and a copolymer of ethylene and an α-olefin having 4 or more carbon atoms. Polyethylene resin such as linear low density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, or styrene-maleic anhydride copolymer, ethylene-propylene system Rubbers such as rubber, ethylene-1-butene rubber, propylene-1-butene rubber, ethylene-propylene-diene rubber, isoprene rubber, neoprene rubber, nitrile rubber, styrene-diene block copolymer and styrene-diene block copolymer. Styrenic thermoplastic elastomers such as hydrogenated products Etc., and the like.
These resins, rubbers, or elastomers can be used in combination of two or more. The total content of the other polymer components is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, based on 100 parts by weight of the styrene resin (A).

(6) Additive The resin composition constituting the expandable styrenic resin particles of the present invention includes polyethylene wax, talc, silica, ethylene bisstearylamide, and methyl methacrylate, within the range not impairing the effects of the present invention. Copolymer, bubble nucleating agent such as silicone, liquid paraffin, glycerol diacetomonolaurate, glycerol tristearate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate, alkyldiethanolamine, glycerin fatty acid Antistatic agents such as esters and sodium alkyl sulfonates, antioxidants such as phenols, phosphorus and sulfur, UV absorbers such as benzotriazoles and benzophenones, light stabilizers such as hindered amines, conductive carbon black , Graphite powder, aluminum Conductive fillers such as copper powder, copper zinc alloy powder, copper powder, silver powder and gold powder, organic antibacterial agents such as IPBC, TBZ, BCM and TPN, inorganic systems such as silver, copper, zinc and titanium oxide Additives such as antibacterial agents may be added.
As other flame retardants and flame retardant aids within the range of not impairing the effects of the present invention, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, tris (chloropropyl) phosphate, tris (2,3-dibromo) Halogen-containing phosphorus flame retardants such as propyl) phosphate and tris (tribromoneopentyl) phosphate, inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, calcium aluminate, expansive graphite and red phosphorus Can be added.
In addition, chain transfer agents such as dodecyl mercaptan and α-methylstyrene dimer can be added within a range not impairing the effects of the present invention.

(7) Foaming agent The foaming agent impregnated in the styrenic resin particles is preferably an organic physical foaming agent having a boiling point of 90 ° C. or lower. Examples of the blowing agent include methane, ethane, propane, n-butane, isobutane, cyclobutane, n-pentane, isopentane, neopentane, cyclopentane, n-hexane, cyclohexane and other saturated hydrocarbon compounds, methanol, ethanol and other lower alcohols. , Ether compounds such as dimethyl ether and diethyl ether. One or two or more organic physical foaming agents having a boiling point of 90 ° C. or lower can be used.
The content of the foaming agent in the expandable styrene resin particles is preferably 3 to 15% by weight, more preferably 5 to 12% by weight in the expandable styrene resin particles. If the content of the foaming agent is within the above range, a desired foaming ratio can be obtained, and in particular, a molded article having a high foaming ratio can be obtained. Moreover, foamability and moldability become favorable, without the cell size of the foaming particle obtained from the said foamable resin particle becoming coarse.

[2] Method for Producing Expandable Styrenic Resin Particles (1) Production of Styrenic Resin Particles The expandable styrenic resin particles of the present invention are obtained by adding polyphenylene ether resin (B) to 100 parts by weight of styrene resin (A). ) 15 to 50 parts by weight, 10 to 30 parts by weight of brominated epoxy resin (C) having a weight average molecular weight of 10,000 to 80,000, and 1 to 15 parts by weight of antimony oxide (D). The resulting resin composition is melt-kneaded at a temperature of 250 to 300 ° C. with an extruder, and the resulting melt is extruded through a small hole in a die attached to the tip of the extruder, and then cut by strand cutting, hot cutting, underwater cutting, etc. It can be obtained by pelletizing or pulverizing with a pulverizer. The weight per resin particle is preferably 0.5 to 5 mg.

(2) Production of expandable styrene resin particles The expandable styrene resin particles of the present invention are produced by dispersing the styrene resin particles in an aqueous suspension in an airtight container and impregnating the foaming agent. It is characterized by making it.
That is, the styrenic resin particles and the aqueous medium are put in a closed container such as a pressure vessel, the styrenic resin particles are suspended in the aqueous medium and sealed, and then a foaming agent is added to the sealed container, Styrenic resin particles are impregnated with a blowing agent. After impregnating the foaming agent, the foamed styrenic resin particles can be obtained by cooling to near room temperature, removing the contents from the sealed container, washing with water, dehydrating, and drying the surface moisture with an air flow dryer or the like. .

When styrenic resin particles are suspended in an aqueous medium, it is preferable to use a suspending agent in order to prevent condensation between the styrenic resin particles. As the suspending agent, for example, hydrophilic polymers such as polyvinyl alcohol, methyl cellulose, and polyvinyl pyrrolidone, and poorly water-soluble inorganic salts such as tricalcium phosphate and magnesium pyrophosphate can be used. An agent may be used in combination. When using a hardly water-soluble inorganic salt, it is preferable to use an anionic surfactant such as sodium alkyl sulfonate or sodium dodecylbenzene sulfonate together.
The amount of the suspending agent used is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the styrene resin particles. When using the said poorly water-soluble inorganic salt and an anionic surfactant together, 0.05-3 weight part of a slightly water-soluble inorganic salt with respect to 100 weight part of styrene resin particles, an anionic surfactant Is preferably used in an amount of 0.0001 to 0.5 parts by weight.

  Moreover, in an aqueous medium, you may contain 0.01-0.2 mol / L electrolyte as needed. The electrolytes include lithium chloride, sodium chloride, magnesium chloride, potassium chloride, calcium chloride, ammonium chloride, sodium sulfate, magnesium sulfate, potassium sulfate, calcium sulfate, aluminum sulfate, ammonium sulfate, sodium nitrate, magnesium nitrate, potassium nitrate, calcium nitrate, Water-soluble inorganic salts such as ammonium nitrate, sodium carbonate, magnesium carbonate, potassium carbonate, ammonium carbonate, or water-soluble carboxyl such as potassium acetate, sodium acetate, sodium octanoate, sodium benzoate, disodium succinate Examples include alkali metal salts of acids.

In the present invention, since the styrenic resin particles are dispersed in an aqueous suspension in an airtight container and impregnated with a foaming agent, the expandable styrene can be added without adding a volatile aromatic hydrocarbon. -Based resin particles can be produced.
The residual amount of volatile aromatic hydrocarbons in the expandable styrenic resin particles is preferably 0.2% by weight or less. By setting the residual amount of volatile aromatic hydrocarbons to 0.2% by weight or less, it is possible to reduce the amount of volatile aromatic hydrocarbons released from the foamed particle molded body obtained from the foamable resin particles. It is possible to obtain a foamed particle molded body corresponding to substance hypersensitivity and sick house syndrome. The residual amount of the volatile aromatic hydrocarbon is more preferably 0.1% by weight or less.
Here, the residual amount of volatile aromatic hydrocarbons was the sum of the contents of styrene, toluene, benzene, m-xylene, p-xylene, o-xylene, ethylbenzene, n-propylbenzene, and i-propylbenzene. The value is a value obtained by dissolving the expandable styrene resin particles in dimethylformamide and obtaining by gas chromatography.

  The ratio of the major axis to the minor axis of the expandable styrene resin particles of the present invention is preferably 1.0 to 2.5. In addition, if it is in the said range, the filling property to the metal mold | die of the expanded particle obtained from expandable styrene resin will become favorable, and a moldability will improve. The ratio of the major axis to the minor axis is more preferably 1.0 to 2.0, still more preferably 1.0 to 1.3.

The ratio of the major axis to the minor axis is determined when the styrene-based resin particles are melt-kneaded when the weight average molecular weight of the brominated epoxy resin is too large and the residual strain during granulation becomes large, or the terminal of the brominated epoxy resin It is assumed that the epoxy group and the terminal phenol group of the polyphenylene ether resin are combined to produce a high molecular weight polymer, the resin viscosity increases, and the residual strain increases, resulting in flattening of the expandable styrene resin particles. The
The foaming agent impregnated in the styrene resin particles is the same as the foaming agent contained in the expandable styrene resin particles described above.
The expandable styrene resin particles of the present invention preferably have an average particle size of 0.3 to 2 mm, more preferably 0.5 to 1.5 mm. If the average particle size is too small, the foaming efficiency tends to be reduced, while if it is too large, the resulting foamed particles become large and the filling property in the mold tends to be lowered during the molding in the mold. The expandable styrenic resin particles are obtained by measuring the maximum outer dimensions of each of the 10 or more expandable resin particles with calipers, and calculating the arithmetic average value of the measured values as the average particle diameter of the expandable styrene resin particles. To do.

[3] Expanded Styrenic Resin Particles The expanded styrene resin particles of the present invention are expanded particles obtained by heating and foaming (pre-expanding) the expandable styrene resin particles by a known method.
For example, specifically, expandable styrenic resin particles are put into a pre-foaming machine (a cylindrical container that has a stirrer and can be heated by blowing steam therein) and heated to foam. The expanded resin particles can be expanded (pre-expanded) to obtain expanded particles.
The bulk density of the resulting foamed particles as described above, 15~200kg / ^{m 3,} it is preferred even at 15~100kg / ^{m 3.} The bulk density of the foamed particles is appropriately selected by adjusting the foaming agent content, the pre-foaming temperature, and the like according to the apparent density of the intended foamed particle molded body and the molding conditions within the mold. Further, the apparent density of the foamed particle molded body is appropriately selected according to the use and the target physical properties of the molded body. If the apparent density of the foamed particle molded body is too low, the strength is insufficient. On the other hand, if the apparent density is too high, it is difficult to sufficiently exhibit the physical properties unique to the foam such as lightness, shock-absorbing property, and heat insulation. It is an economy.
The bulk density (kg / m ³ ) of the foamed particles is such that the foamed particles left for 1 day under the conditions of 50% relative humidity, 23 ° C. and 1 atm are placed in a graduated cylinder with a capacity of 1000 cm ³ and a bulk volume of 1000 cm ^3. filled up to the mark of 1000 cm ^3, the weighed weight of the foamed particles were placed in a graduated cylinder W1 (g) up to one decimal place, the weight of the foamed particles per bulk volume 1000cm ³ W1 (g) a unit It is obtained by converting (W1 / 1000 × 1000).

[4] Styrenic resin foam particle molded body The styrene resin foam particle molded body of the present invention is a foam particle molded body obtained by molding the styrene resin foam particles in a mold.
Specifically, the styrenic resin foam particles were filled into a mold, heated and foamed, and the styrenic resin foam particles were fused together to obtain a foamed particle molded body. Thus, it is preferable that the apparent density of the obtained expanded foam molded body is 15 to 200 kg / m ³ . If the density is low, the strength is insufficient. Conversely, if the density is high, the heat insulating property and light weight of the foamed molded article may not be obtained. The apparent density of the foamed molded product is preferably 15 to 100 kg / m ³ .
The apparent density (kg / m ³ ) of the foamed particle molded body is obtained by dividing the weight of the foamed particle molded body by the volume of the foamed molded body. For example, it is obtained by dividing the foamed particle molded body weight WM (g) by the volume VM (cm ³ ) obtained from the external dimensions of the foamed particle molded body and converting the unit (WM / VM × 1000).

  The present invention will be specifically described below with reference to examples and comparative examples.

[Example 1]
(1) Production of expandable resin particles 70 parts by weight of a styrene resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin so as to have the resin composition shown in Table 2 Compound (SABIC Innovative Plastics Japan Co., Ltd., trade name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound)) 30 parts by weight, brominated epoxy resin and antimony oxide compound (brominated) Epoxy resin Sakamoto Yakuhin Kogyo Co., Ltd., trade name: SR-T7040 (brominated epoxy resin 60% by weight / antimony trioxide 20% by weight / styrene resin 20% by weight compound)) 30 parts by weight, φ30mm extruder (cylinder temperature 280-290 ° C) And melt kneading to obtain a resin composition in a molten state. The molten resin composition was extruded in a strand form from a small hole of φ2.0 mm attached to the extruder, and then the strand was introduced into a water bath at about 25 ° C., rapidly solidified, and cut by a pelletizer to obtain about 1.5 mg. Cylindrical styrene resin particles were obtained.

Next, 4 g of sodium pyrophosphate was dissolved in 900 g of deionized water in an autoclave having a 3 L internal volume equipped with a stirrer, and 8 g of anhydrous magnesium sulfate was added to synthesize magnesium pyrophosphate. The autoclave was sealed by adding 0.45 g of sodium alkyl sulfonate and 600 g of the styrene resin particles.
Next, the temperature was raised while stirring at 350 rpm, and the temperature was raised to 120 ° C. over 1 hour and a half. When 120 ° C. was reached, 90 g of pentane (a mixture of n-pentane 80% and isopentane 20%) as a blowing agent was pressed into the autoclave for 60 minutes. After maintaining at 120 ° C. for 10 hours after reaching 120 ° C., it was cooled to 30 ° C. over about 6 hours.
After cooling, the contents were taken out, washed with water, dehydrated with a centrifugal separator, and water attached to the surface was removed with a fluidized dryer to obtain substantially spherical particles having an average particle diameter of 1.5 mm. To 100 parts by weight of the obtained particles, 0.005 part by weight of N, N-bis (2-hydroxyethyl) alkylamine as an antistatic agent is added, and 0.06 part by weight of zinc stearate and glycerin mono The foamed styrene resin particles impregnated with a foaming agent were obtained by coating with a mixture of 0.02 part by weight of stearate.

(2) Foamed particles, foamed particle molded body After the obtained expandable styrene resin particles were aged at 6 ° C. for 1 day, 500 g of the expandable styrene resin particles were put into a pressure batch foaming machine having a volume of 45 L, Steam was supplied so that the water vapor pressure in the foaming machine was 0.03 MPa as a gauge pressure, heated for 60 seconds, and then air-dried in the foaming machine for 60 seconds to obtain expanded particles having a bulk density of 30 kg / m ³ . .
The obtained expanded particles were aged at room temperature for 1 day, then filled in a mold of a molding machine (manufactured by Daisen Kogyo Co., Ltd., model: VS300), heated for 20 seconds with steam having a gauge pressure of 0.15 MPa, and cooled with water. After cooling for 10 seconds and vacuum cooling for 60 seconds, it was taken out from the mold, and a flat-plate-shaped foamed particle molded body having a length of 300 mm × width of 200 mm × thickness of 25 mm was obtained. After curing at 60 ° C for 1 day, it was used for various evaluations.

[Example 2]
70 parts by weight of styrene-based resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), compound of polyphenylene ether resin (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 2. Product name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound)) 30 parts by weight, brominated epoxy resin and antimony oxide compound (brominated epoxy resin, Sakamoto Pharmaceutical Co., Ltd.) , Trade name: SR-T7040, (compound product of brominated epoxy resin 60% by weight / antimony trioxide 20% by weight / styrene resin 20% by weight)) and 40 parts by weight. Resin particles were obtained.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.

[Example 3]
70 parts by weight of styrene-based resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), compound of polyphenylene ether resin (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 2. Product name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound)) 30 parts by weight, brominated epoxy resin and antimony oxide compound (brominated epoxy resin, Sakamoto Pharmaceutical Co., Ltd.) , Trade name: SR-T7040, (compound product of brominated epoxy resin 60% by weight / antimony trioxide 20% by weight / styrene resin 20% by weight)) and mixed with 20 parts by weight. Resin particles were obtained.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.

[Example 4]
65 parts by weight of styrene-based resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 2. Product name: NORYL PKN4752, (compound product of 70% by weight of polyphenylene ether resin / 30% by weight of polystyrene)), compound of brominated epoxy resin and antimony oxide (brominated epoxy resin, Sakamoto Pharmaceutical Co., Ltd.) , Trade name: SR-T7040, (compound product of brominated epoxy resin 60% by weight / antimony trioxide 20% by weight / styrene resin 20% by weight)) and 30 parts by weight. Resin particles were obtained.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.

[Example 5]
70 parts by weight of styrene-based resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), compound of polyphenylene ether resin (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 2. Product name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound)) 30 parts by weight, brominated epoxy resin and antimony oxide compound (brominated epoxy resin, Sakamoto Pharmaceutical Co., Ltd.) , Trade name: SR-T5000, (60 wt% / antimony trioxide 20 wt% / styrene resin 20 wt% compound product)) 30 parts by weight were mixed, and styrene resin particles were obtained in the same manner as in Example 1. It was.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.

[Example 6]
70 parts by weight of styrene-based resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), compound of polyphenylene ether resin (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 2. Product name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound)) 30 parts by weight, brominated epoxy resin and antimony oxide compound (brominated epoxy resin, Sakamoto Pharmaceutical Co., Ltd.) SR-T 20000, 30 parts by weight (compound product of 60% by weight of brominated epoxy resin / 20% by weight of antimony trioxide / 20% by weight of styrene resin) are mixed, and styrene resin particles are obtained in the same manner as in Example 1. It was.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.

[Comparative Example 1]
70 parts by weight of styrene resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 3. Product name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound)) 30 parts by weight, brominated epoxy resin and antimony oxide compound (brominated epoxy resin, Sakamoto Pharmaceutical Co., Ltd.) , Trade name: SR-T7040 (compound product of 60% by weight of brominated epoxy resin / 20% by weight of antimony trioxide / 20% by weight of styrene resin)) and 12 parts by weight. Resin particles were obtained.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.
In Comparative Example 1, brominated epoxy resin and antimony trioxide were used as flame retardants. However, since the blending amount of brominated epoxy resin with respect to 100 parts by weight of styrene resin was less than 10 parts by weight, self-extinguishing properties were exhibited. There wasn't.

[Comparative Example 2]
80 parts by weight of styrene resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan Co., Ltd.) so that the resin composition shown in Table 3 is obtained. Product name: NORYL PKN4752, polyphenylene ether resin 70% by weight / polystyrene ether 30% by weight compound) 20 parts by weight, brominated epoxy resin (brominated epoxy resin Sakamoto Yakuhin Kogyo Co., Ltd.), product name: SR-T7040) 20 parts by weight were mixed to obtain styrene resin particles in the same manner as in Example 1.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.
In Comparative Example 2, brominated epoxy resin was used as a flame retardant, but antimony trioxide was not added.
Since no antimony trioxide was added, self-extinguishing properties did not appear.

[Comparative Example 3]
20 parts by weight of styrene resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan Co., Ltd.) so that the resin composition shown in Table 3 is obtained. Product name: NORYL PKN4752, (compound product of 70% by weight of polyphenylene ether resin / 30% by weight of polystyrene)) 80 parts by weight, 20 parts by weight of triphenyl phosphate as a flame retardant, and styrene as in Example 1 System resin particles were obtained.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.
In Comparative Example 3, triphenyl phosphate was used as a flame retardant instead of brominated epoxy resin.
When triphenyl phosphate is used, it is understood that self-extinguishing properties do not appear unless a large amount is blended. In addition, triphenyl phosphate also acts as a plasticizer, and the heat resistance of the obtained foamed particle molded body is lowered. Therefore, it is difficult to achieve both heat resistance and self-extinguishing properties.

[Comparative Example 4]
25 parts by weight of styrene resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan Co., Ltd.) so as to have the resin composition shown in Table 3. Product name: NORYL PKN4752, (polyphenylene ether resin 70% by weight / polystyrene 30% by weight compound product) 25 parts by weight, aromatic condensed phosphate ester (made by Daihachi Chemical Co., Ltd., product name) as flame retardant 50 parts by weight of PX-200 ((Aromatic condensed phosphate ester 20% by weight / NORYL PKN4752 80% by weight compound)) was mixed, and styrene resin particles were obtained in the same manner as in Example 1.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.
In Comparative Example 4, phosphate ester was used as a flame retardant instead of brominated epoxy resin. When using phosphate ester, it turns out that self-extinguishing property is not expressed unless phosphate ester is blended in a large amount. In addition, since the phosphate ester also acts as a plasticizer and the heat resistance of the obtained foamed particle molded body is lowered, it is difficult to achieve both heat resistance and self-extinguishing properties.

[Comparative Example 5]
80 parts by weight of styrene resin (manufactured by PS Japan Co., Ltd., trade name: 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan Co., Ltd.) so that the resin composition shown in Table 3 is obtained. Product name: NORYL PKN4752, (compound product of 70% by weight of polyphenylene ether resin / 30% by weight of polystyrene)), compound of brominated polystyrene and antimony oxide (trade name: PC-80G, manufactured by Suzuhiro Chemical Co., Ltd.) 10 parts by weight of antimony trioxide 20% blended product) was mixed and styrene resin particles were obtained in the same manner as in Example 1.
Except using the styrene resin particles, expandable styrene resin particles, styrene resin foam particles, and styrene resin foam particle molded bodies were obtained in the same manner as in Example 1.
In Comparative Example 5, brominated polystyrene was added as a flame retardant. The mold was filled with foamed particles and heated in steam and molded in the mold. However, the mold contracted remarkably, and a foamed particle molded product could not be obtained. This is probably because, when brominated polystyrene is blended, the closed cell ratio of the obtained foamed particles is reduced to 56%, and the secondary foaming force necessary for molding is insufficient.

[Comparative Example 6]
80 parts by weight of styrene resin (PS Japan, 680, weight average molecular weight 170,000), polyphenylene ether resin compound (SABIC Innovative Plastics Japan, product) Name: NORYL PKN4752, (Compound product of 70% by weight of polyphenylene ether resin / 30% by weight of polystyrene), 2,2-bis (4- (2,3-3-) which is a low molecular weight brominated epoxy compound as a flame retardant 5 parts by weight of dibromopropoxy) -3,5-dibromophenyl) propane (manufactured by Suzuhiro Chemical Co., Ltd., trade name: HIROMASTER 680MB-75, 25% by weight of antimony trioxide) was mixed. After melt kneading at a cylinder temperature of 280 to 290 ° C., φ2. It was extruded from mm small holes into strands, but the strand is cut off, it was impossible to obtain a styrene-based resin particles.
In Comparative Example 6, low molecular weight 2,2-bis (4- (2,3-dibromopropoxy) -3,5-dibromophenyl) propane was used as a flame retardant instead of brominated epoxy resin. Since the stability is poor, it is difficult to produce styrene resin particles.

  Table 1 shows the physical properties of the brominated epoxy resins used in the examples and comparative examples.

  Example, composition of resin composition in comparative example, content of foaming agent, content of volatile aromatic hydrocarbons, major axis / minor axis ratio of expandable resin particles, heating dimensional change rate of molded foam particles, combustion The test results are summarized in Tables 2 and 3.

(Evaluation method)
Content of foaming agent, ratio of major axis / minor axis, content of volatile aromatic hydrocarbons in the expandable styrene resin particles obtained above, and rate of change in heating dimensions of the obtained foamed particle molded body, combustion The test was evaluated by the following method.

(1) Residual Amount of Volatile Aromatic Hydrocarbons In the present invention, the residual amount of each component of the volatile aromatic hydrocarbons in the expandable resin particles is determined by using a sample of the expandable resin particles as dimethylformamide (DMF). And can be quantified by gas chromatography.
Expandable styrene resin particles are dissolved in dimethylformamide, and each of styrene, toluene, benzene, m-xylene, p-xylene, o-xylene, ethylbenzene, n-propylbenzene, i-propylbenzene is analyzed by gas chromatography. The residual amount was measured, and the residual amount of each component was summed up.
Note that the remaining amount of the volatile aromatic hydrocarbon is a volatile component and changes with time. Therefore, in the expandable resin particles of the present invention, it is the remaining amount of the volatile aromatic hydrocarbon component in the expandable resin particles immediately before being expanded by the expansion machine.
Specifically, the gas chromatograph was quantified by the following procedure.
<1> About 5 g of cyclopentanol was precisely weighed to the third decimal place (the weight at this time is Wi) in a 100 mL volumetric flask, and DMF was added to make a total of 100 mL. This DMF solution was further diluted 100 times with DMF to obtain an internal standard solution.
<2> About 1 g of the measurement sample was precisely weighed to the third decimal place from the expandable resin particles to be measured, and the weight at this time was defined as WS (g).
<3> The precisely weighed sample was dissolved in about 18 mL of DMF, and 2 mL of the internal standard solution prepared in 1 above was accurately added using a whole pipette.
<4> 1 μL of this solution was collected with a microsyringe and introduced into a gas chromatograph to obtain a chromatogram.
The peak areas of each aromatic hydrocarbon component and internal standard were determined from the obtained chromatogram, and the concentration of each component was determined by the following equation.

Concentration of each component (% by weight) = [(Wi / 10000) × 2] × [An / Ai] × Fn ÷ WS × 100
(However, Wi: cyclopentanol weight (g) when the internal standard solution was prepared, WS: sample weight (g) dissolved in DMF, An: peak area of each aromatic hydrocarbon at the time of gas chromatograph measurement, Ai: peak area of internal standard substance at the time of gas chromatograph measurement, Fn: correction coefficient of each aromatic hydrocarbon component obtained from a calibration curve prepared in advance.)
The conditions for the gas chromatograph analysis were as follows.
Equipment used: Gas chromatograph GC-6AM manufactured by Shimadzu Corporation
Column material: Glass column with inner diameter of 3 mm and length of 5000 mm Column filler: [Liquid phase name] FFAP (free fatty acid), [Liquid phase impregnation rate] 10 wt%, [Carrier name] Diatomaceous earth Chromosorb W for gas chromatography, [Carrier Particle size] 60/80 mesh, [Carrier treatment method] AW-DMCS (washing, baking, acid treatment, silane treatment), [Packing amount] 90 mL
Inlet temperature: 250 ° C
Column temperature: 120 ° C
Detector temperature: 250 ° C
Carrier gas: N ₂ , flow rate 40 m / min.
Detector: FID (hydrogen flame ionization detector)
Detection limit: 20 ppm by weight
In the present invention, when the remaining amount of each component of the volatile aromatic hydrocarbon in the expandable resin particle or the expanded molded particle is below the detection limit, the remaining amount of the component is regarded as 0% by weight. It was.

(2) Content of foaming agent The foaming styrene resin particles were dissolved in dimethylformamide, and the foaming agent added (in the case of Example 1, n-pentane, i-Pentane) Each content was measured, and the content of each component was totaled.

(3) Ratio of major axis / minor axis of expandable resin particles About ten expandable styrene resin particles collected arbitrarily, the maximum value of the outer dimensions of the expandable styrene resin particles is defined as the major axis, and the minimum value is defined as the minor axis. Measurement was made with a caliper to 0.1 mm, the major axis / minor axis ratio was calculated, and the obtained major axis / minor axis ratio was obtained by arithmetic averaging.

(4) Formability evaluation of expanded particles The in-mold moldability of expanded particles was evaluated according to the following criteria.
A: The surface of the foamed particle molded body is smooth and there are few gaps between the foamed particles.
○: The filling property of the expanded particles into the mold tends to be lowered, and a gap between the expanded particles is observed.
×: Not moldable

(5) Heating dimensional change rate The heating dimensional change rate was measured according to JIS K 6767 high temperature dimensional stability (Method B) except that the test temperature was changed to 95 ° C, 100 ° C, and 105 ° C. The heating dimensional change rate indicates the heat resistance of the foamed particle molded body, and the smaller the absolute value of the heating dimensional change rate value, the better the heat resistance.
Specifically, the foamed particle molded body is cut to prepare a test piece having a length of 150 mm, a width of 150 mm, and a thickness of 25 mm, and three straight lines are parallel to each other in the vertical and horizontal directions at intervals of 50 mm. The length of the filled-in line was measured, and the average value was obtained to obtain the dimension before heating. Place the test piece horizontally in each hot air circulation dryer adjusted to 95 ° C, 100 ° C and 105 ° C, hold it for 22 hours, take it out and leave it in a constant temperature room at 23 ° C for 1 hour. Then, the dimensions were obtained in the same manner as before the heating, and the heating dimensional change rate was obtained by the following formula using this as the dimension after the heating.
Heating dimensional change rate (%) = (l ₁ −l ₀ ) / l ₀ × 100
Here, l ₀ : dimension before heating (mm), l ₁ : dimension after heating (mm).

(6) Combustion test (self-extinguishing)
In the present invention, the self-extinguishing property means passing a combustion test (Method A) of JIS A 9511 (2006). Specifically, after molding the foamed particle molded body and curing at 40 ° C. for 24 hours, five test pieces having a thickness of 10 mm, a length of 200 mm, and a width of 25 mm were cut out from the molded body, and the ignition limit indicator line and Attach the combustion limit indicator line. Stand at the end of the test piece at an angle of about 45 degrees, ignite to the ignition limit indicator line for about 5 seconds, quickly retract the candle, and measure the time from the moment until the flame disappears did. When the average flame extinguishing time of 5 test pieces is within 3 seconds, there is no residual dust, and combustion does not continue beyond the combustion limit line, self-extinguishing properties are assumed.

Claims (4)

  A foam comprising a resin composition comprising a styrene resin (A), a polyphenylene ether resin (B), a brominated epoxy resin (C) having a weight average molecular weight of 10,000 to 80,000, and antimony oxide (D). Expandable styrene resin particles impregnated with an agent, the resin composition comprising 15 to 50 parts by weight of polyphenylene ether resin (B) and 100 parts by weight of styrene resin (A), brominated epoxy resin (C) Expandable styrene-based resin particles containing 10 to 30 parts by weight and 1 to 15 parts by weight of antimony oxide (D).   2. The expandable styrene-based resin particle according to claim 1, wherein an epoxy equivalent of the brominated epoxy resin (C) is 20,000 g / eq or more.   A styrene-based resin foamed particle molded body, wherein the styrene-based resin foamed particles obtained by foaming the expandable styrene-based resin particles according to claim 1 or 2 are molded in a mold.   Brominated epoxy having a styrene resin (A) and 10 to 50 parts by weight of polyphenylene ether resin (B) and a weight average molecular weight of 10,000 to 80,000 with respect to 100 parts by weight of the styrene resin (A). A resin composition obtained by blending 10 to 30 parts by weight of resin (C) and 1 to 15 parts by weight of antimony oxide (D) is melt-kneaded in an extruder and extruded, then cut and styrene resin A method for producing expandable styrene resin particles, comprising obtaining particles, dispersing the styrene resin particles in an aqueous suspension in an airtight container, and impregnating the styrene resin particles with a foaming agent.