JP6306643B2 - Expandable styrene resin particles and method for producing the same, styrene resin foam molded article - Google Patents

Description

  The present invention relates to an expandable styrene resin particle and a method for producing the same, and a styrene resin foam molded article used for a heat insulating material obtained by using the expandable styrene resin particle.

  Styrenic resin foam molded products obtained by using expandable styrene resin particles have been conventionally used as a food product box, a cold box, a cushioning material, and a foam having an excellent balance of light weight, heat insulation, buffering properties, and the like. It is widely used as a heat insulating material for houses.

  In recent years, in connection with various problems such as global warming, energy saving has been aimed at by improving the heat insulation performance of buildings such as houses, and the demand for styrene resin foam molded products is expected to increase, and further improvement of heat insulation performance Various studies have been made.

Regarding heat insulation performance improvement of a styrene resin foam molded article, for example, Patent Document 1 discloses that heat for a heat insulating material is characterized in that fine powder having an infrared reflectance of 40% or more is uniformly dispersed in bubbles. A plastic resin foam has been proposed, and graphite or the like is mentioned as a fine powder. Patent Document 2 discloses a styrene resin foam having a density of 10 to 100 kg / m ³ , a closed cell ratio of 60% or more, an average cell diameter of 20 to 1000 μm, and containing graphite powder. Styrenic resin foams having an aspect ratio of 5 or more have been proposed.

  Furthermore, Patent Document 3 discloses a particulate expandable styrene characterized by containing a graphite powder that can be processed to yield a foam having a density of 35 g / l or less and that is uniformly distributed. As a flame retardant, an organic bromine compound having a bromine content of 70% by weight or more as a flame retardant has been proposed. Techniques containing saponins have been proposed.

On the other hand, regarding the flame retardancy of a styrene resin foam molded article obtained from expandable styrene resin particles, Patent Document 4 takes the above Patent Document 3 as an example, and the prior art disclosed in Patent Document 3 is a flame retardant. As an organic bromine compound such as hexabromocyclododecane, the organic bromine compound disclosed in Patent Document 3 may adversely affect the environment from the standpoint of difficulty of decomposition and high accumulation. In the field of flame retardant polystyrene resin foam moldings, there are problems that are difficult to use. As a flame retardant, it has a bromine atom in the molecule, the bromine content is less than 70% by mass, and a benzene ring in the molecule. And 5% by mass decomposition temperature of the flame retardant is in the range of 200 to 300 ° C., the entire flame retardant content (A) of the expandable polystyrene resin particles, Resin particles Proposes a flame retardant-containing expandable polystyrene resin particles, wherein the ratio of the flame retardant content of the surface (B) (B / A) is in the range of 0.8 to 1.2.
However, Patent Document 4 does not suggest at all whether or not it was effective against the reduction in flame retardancy, which is a problem when using the graphite powder, which was a problem in Patent Document 3.

Japanese Unexamined Patent Publication No. 63-183941 JP 2005-2268 A Special table 2001-525001 gazette JP 2011-93947 A

  In view of the above problems, the present invention solves the problem with respect to a decrease in flame retardancy when a radiation heat transfer inhibitor such as graphite is added, and has heat insulation using a flame retardant with high environmental compatibility. To provide an expandable styrene resin particle capable of obtaining a styrene resin foam molded article having both flame retardancy, a production method thereof, and a styrene resin foam molded article using the expandable styrene resin particle. is there.

  As a result of intensive studies to solve the above problems, the present inventor used a brominated flame retardant having specific characteristics together with a radiant heat transfer inhibitor, and used a radiant heat transfer inhibitor content and a brominated flame retardant. It has been found that by including the weight ratio of the bromine content derived so as to be in a specific range, expandable styrene resin particles having both heat insulation and flame retardancy and excellent environmental compatibility can be obtained. The invention has been completed.

That is, the present invention
[1] 3 to 10 parts by weight of a foaming agent composed of at least one hydrocarbon having 3 to 6 carbon atoms, 1 to 6 parts by weight of a radiation heat transfer inhibitor, and 100 parts by weight of a styrene-based resin, Foam containing 0.5 to 6 parts by weight of a brominated flame retardant having a 1% weight loss temperature in a thermogravimetric analysis of 210 ° C. to 280 ° C. and a bromine content of 60% by weight or more and less than 70% by weight Styrenic resin particles,
The bromine atom content / radiant heat transfer inhibitor content, which is the ratio of the bromine atom content derived from the brominated flame retardant to the radiation inhibitor content in the expandable styrene resin particles, is 1 / 0.15 to 1 / Expandable styrenic resin particles, characterized by being 2.0.
[2] The expandable styrene resin particles according to [1], further comprising 0.05 to 1.0 part by weight of a radical generator with respect to 100 parts by weight of the styrene resin.
[3] The expandable styrenic resin according to [1] or [2], further comprising 0.1 to 10 parts by weight of a heat stabilizer with respect to 100 parts by weight of the brominated flame retardant. particle.
[4] Any one of [1] to [3], wherein the radiation heat transfer inhibitor is at least one compound selected from the group consisting of graphite, graphene, activated carbon, carbon black, and titanium oxide. The expandable styrene resin particle according to Item 1.
[5] The brominated flame retardant is at least one compound selected from the group consisting of brominated bisphenol compounds, brominated isocyanurate compounds, and brominated styrene butadiene copolymers, [1] ] The expandable styrene resin particle of any one of [4].
[6] The foaming agent is at least one compound selected from the group consisting of normal pentane, isopentane, cyclopentane and neopentane, according to any one of [1] to [5] Expandable styrene resin particles.
[7] The thermal stabilizer is at least one compound selected from the group consisting of a hindered amine compound, a phosphorus compound, and an epoxy compound, Any one of [3] to [6] Expandable styrene resin particles as described in 1.
[8] The expandable styrenic resin particles according to any one of [1] to [6] are heated to be prefoamed to obtain prefoamed particles, which are then filled into a molding cavity and foamed in the mold. A foamed molded article obtained by molding.
A foam-molded product obtained by filling a molding cavity and molding in-mold after obtaining a child.
[9] 3 to 10 parts by weight of a foaming agent composed of at least one hydrocarbon having 3 to 6 carbon atoms, 1 to 6 parts by weight of a radiation heat transfer inhibitor, 0.5 to 6 parts by weight of a brominated flame retardant having a 1% weight loss temperature in a gravimetric analysis of 210 ° C. to 280 ° C. and a bromine content of 60% by weight or more and less than 70% by weight using an extruder After melt-kneading and cooling to a predetermined temperature, it is extruded through a die having small holes into a cutter chamber filled with pressurized circulating water, and immediately after extrusion, cut by a rotary cutter and cooled by pressurized circulating water. A production method for solidifying to obtain expandable styrene resin particles,
The bromine atom content / radiation heat transfer inhibitor content, which is the ratio of the bromine atom content derived from the brominated flame retardant to the radiation inhibitor content in the expandable styrenic resin particles, is 1 / 0.15-1. The method for producing expandable styrenic resin particles according to any one of [1] to [7], which is /2.0.
[10] 1 to 6 parts by weight of a radiation heat transfer inhibitor with respect to 100 parts by weight of a styrene-based resin, 1% weight loss temperature in thermogravimetric analysis is 210 ° C. to 280 ° C., and bromine content is 60 Styrenic resin particles are obtained by melting and kneading 0.5 to 6 parts by weight of a brominated flame retardant that is not less than 70% by weight with an extruder, extruding through a die having a small hole, and then cutting with a cutter. After getting
Suspending the styrene resin particles in water and supplying an amount of 3 to 10 parts by weight of a foaming agent comprising at least one hydrocarbon having 3 to 6 carbon atoms with respect to 100 parts by weight of the styrene resin A production method for obtaining expandable styrene resin particles,
The bromine atom content / radiant heat transfer inhibitor content, which is the ratio of the bromine atom content derived from the brominated flame retardant to the radiation inhibitor content in the expandable styrene resin particles, is 1 / 0.15 to 1 / The method for producing expandable styrenic resin particles according to any one of [1] to [7], which is 2.0.
[11] The method according to [9] or [10], wherein 0.05 to 1.0 part by weight of a radical generator is further melt-kneaded with an extruder with respect to 100 parts by weight of a styrene-based resin. Of producing expandable styrene resin particles.
[12] Further, any one of [9] to [11], wherein 0.1 to 10 parts by weight of a heat stabilizer is melt-kneaded with an extruder with respect to 100 parts by weight of a brominated flame retardant. 2. A method for producing expandable styrene resin particles according to item 1.

  According to the present invention, even when a radiant heat transfer inhibitor is used, the flame retardancy is not lowered, and a flame retardant excellent in environmental compatibility is used, and also includes a radiant heat transfer inhibitor. Therefore, it is possible to provide a foamable styrene resin particle having a low thermal conductivity, a high flame retardance and a heat insulating property and a production method, and a styrene resin foam molded article using the foamable styrene resin particle. it can.

  Hereinafter, the present invention will be described in more detail.

  The expandable styrene resin particles of the present invention are 3 to 10 parts by weight of a foaming agent composed of at least one hydrocarbon having 3 to 6 carbon atoms, and a radiation heat transfer inhibitor, based on 100 parts by weight of the styrene resin. 1 to 6 parts by weight of a brominated flame retardant having a 1% weight loss temperature in a thermogravimetric analysis of 210 ° C. to 280 ° C. and a bromine content of 60% to less than 70% by weight. Expandable styrenic resin particles containing ˜6 parts by weight.

  The styrenic resin used in the present invention is not only a styrene homopolymer (polystyrene homopolymer), but also other monomers or derivatives thereof copolymerizable with styrene within a range that does not impair the effects of the present invention. (However, the brominated styrene / butadiene copolymer described later is excluded).

Examples of other monomers copolymerizable with styrene or derivatives thereof include, for example, methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, bromostyrene, dibromostyrene, tribromostyrene, chlorostyrene, dichlorostyrene, Styrene derivatives such as trichlorostyrene;
Polyfunctional vinyl compounds such as divinylbenzene;
(Meth) acrylic acid ester compounds such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate;
Vinyl cyanide compounds such as (meth) acrylonitrile;
Diene compounds such as budadiene or derivatives thereof;
Unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride;
N-methylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-4-diphenylmaleimide, N-2-chlorophenylmaleimide, N-4-bromophenylmaleimide, N-1-naphthylmaleimide, etc. N-alkyl substituted maleimide compounds and the like.
These may be used alone or in combination of two or more.

  The styrene resin used in the present invention is not limited to the styrene homopolymer and / or a copolymer with other monomers copolymerizable with styrene or a derivative thereof, and does not impair the effects of the present invention. It may be a blend with a homopolymer or copolymer of the other monomer or derivative, such as diene rubber reinforced polystyrene, acrylic rubber reinforced polystyrene, polyphenylene ether resin, etc. It can also be blended.

  Among the styrenic resins used in the present invention, it is relatively inexpensive and can be foam-molded with low-pressure steam or the like without using a special method, and is excellent in the balance of heat insulation, flame retardancy, and buffering properties. Polystyrene homopolymer, styrene-acrylonitrile copolymer, and styrene-butyl acrylate copolymer are preferred.

Examples of the hydrocarbon having 3 to 6 carbon atoms as the blowing agent used in the present invention include propane, normal butane, isobutane, normal pentane, isopentane, cyclopentane, neopentane, normal hexane, and cyclohexane.
These foaming agents can be used alone or in admixture of two or more.
Among these blowing agents, hydrocarbons having 4 or 5 carbon atoms are preferable from the viewpoint of easy control of the target expansion ratio, and normal butane, isobutane, normal pentane, isopentane from the viewpoint of foamability and moldability. Is particularly preferred.

  The content of the foaming agent in the foamable styrene resin particles in the present invention and the addition amount used at the time of production are easily controlled with respect to 100 parts by weight of the styrene resin from the viewpoint of easily controlling the target foaming ratio. It is preferably 3 to 10 parts by weight, more preferably 4 to 9 parts by weight, and still more preferably 5 to 8 parts by weight.

  In the present invention, the “radiant heat transfer inhibitor” is a substance that can suppress radiant heat transfer among heat transfer mechanisms that are transmitted through the foamed molded product, and has the same resin, foaming agent, cell structure, and density. In the foamed molded article, a substance having an effect of lowering the thermal conductivity compared to the additive-free system by adding a radiation heat transfer inhibitor is said.

  The radiation heat transfer inhibitor used in the present invention is not particularly limited as long as it has a property of reflecting, scattering, and absorbing light in the near infrared or infrared region (for example, a wavelength region of about 800 to 3000 nm). It is not something.

As a radiation heat transfer inhibitor used in the present invention, for example,
Aluminum compounds such as aluminum and aluminum oxide, zinc compounds such as zinc aluminate; magnesium compounds such as hydrotalcite; silver compounds such as silver:
Titanium compounds such as titanium, titanium oxide, strontium titanate;
Heat ray reflectors such as stainless steel, nickel, tin, silver, copper, bronze, shirasu balloon, ceramic balloon, micro balloon, pearl mica,
Carbon compounds such as carbon black, graphite, graphene, activated carbon;
Metal sulfates such as barium sulfate, strontium sulfate, calcium sulfate, mercalite, halothrite, alumite, iron alumite;
Antimony compounds such as antimony trioxide, antimony oxide, and anhydrous zinc antimonate;
Metal oxides such as tin oxide, indium oxide, zinc oxide, and indinium tin oxide; ammonium, urea, imonium, aminium, cyanine, polymethine, anthraquinone, dithiol, copper ion, phenylenediamine , Phthalocyanine, benzotriazole, benzophenone, oxalic anilide, cyanoacrylate, benzotriazole, and the like.
These radiation heat transfer inhibitors may be used alone or in combination of two or more.

  Among these radiant heat transfer inhibitors, graphite, graphene, activated carbon, and titanium oxide are preferable from the viewpoint of excellent balance between thermal conductivity reduction effect and cost. Graphite and graphene are particularly preferable because the effect of reducing the thermal conductivity is exhibited with a relatively small amount.

  The content of the radiant heat transfer inhibitor in the present invention in the expandable styrenic resin particles and the addition amount used at the time of manufacture are easily controlled to the target expansion ratio, and the thermal conductivity reduction effect, flame retardancy From the viewpoint of balance such as, it is preferably 1 part by weight or more and 6 parts by weight or less, more preferably 1.5 parts by weight or more and 5.5 parts by weight or less, with respect to 100 parts by weight of the styrene resin. More preferably, it is 2 parts by weight or more and 5 parts by weight or less.

Examples of the brominated flame retardant having a 1% weight loss temperature in thermogravimetric analysis of 210 ° C. to 280 ° C. and a bromine content of 60 wt% or more and less than 70 wt% used in the present invention include: 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane (also known as tetrabromobisphenol A-bis (2,3-dibromo-2-methylpropyl ether) ), 2,2-bis [4- (2,3-dibromopropoxy) -3,5-dibromophenyl] propane (also known as tetrabromobisphenol A-bis (2,3-dibromopropyl ether)) Compounds;
Brominated isocyanurate compounds such as tris (2,3-dibromopropyl) isocyanurate;
Brominated styrene / butadiene block copolymers, brominated random styrene / butadiene copolymers, brominated butadiene / vinyl aromatic hydrocarbon copolymers such as brominated styrene / butadiene graphs and copolymers (for example, JP 2009) -Disclosed in JP-A-516019).
These brominated flame retardants may be used alone or in admixture of two or more.

  Here, the 1% by weight reduction temperature in thermogravimetric analysis was determined by using a thermogravimetric analyzer [DTG-60A, manufactured by Shimadzu Corporation] and weighing a 5 mg sample at a rate of temperature increase of 10 ° C./min. It is the value measured by heating from 30 ° C to 350 ° C.

  In order to determine whether the effect of the brominated flame retardant is expressed, the temperature range (210 to 280 ° C.) in the present invention is determined based on the temperature at which the brominated flame retardant starts to decompose. 4 is more effective than the temperature range (200 to 300 ° C.) defined by 4 and particularly effective for expandable styrene resin particles to which a radiant heat transfer inhibitor is added, and a styrene resin foam molded article obtained using the same. We have found that.

In the present invention, the content of the brominated flame retardant in the expandable styrene resin particles and the addition amount used at the time of production are easily controlled to the target expansion ratio, and the flame retardant at the time of addition of the radiant heat transfer inhibitor From the viewpoint of balance such as property, it is preferably 0.5 parts by weight or more and 6 parts by weight or less, more preferably 1 part by weight or more and 5 parts by weight or less, with respect to 100 parts by weight of the styrene resin. More preferably, it is 5 parts by weight or more and 4 parts by weight or less.
However, the content of the brominated flame retardant varies depending on the presence / absence, addition amount, etc. of a radical generator and a thermal stabilizer, which will be described later.

In this invention, in order to solve the problem regarding the flame retardance at the time of adding a radiant heat transfer inhibitor using a brominated flame retardant having high environmental compatibility, 1% weight in thermogravimetric analysis as a brominated flame retardant A brominated flame retardant having a decreasing temperature of 210 ° C. to 280 ° C. and a bromine content of 60% by weight or more and less than 70% by weight is used, and with respect to the radiation inhibitor content in the expandable styrene resin particles. It is important that the bromine atom content / radiant heat transfer inhibitor content, which is the ratio of the bromine atom content derived from the brominated flame retardant, is 1 / 0.15 to 1 / 2.0.
That is, when the content of the radiation heat transfer inhibitor in the expandable styrene resin particles is 1, the bromine atom content ratio derived from the brominated flame retardant is preferably 0.15 or more and 2.0 or less, 0.20 to 1.5 is more preferable, and 0.30 to 1.0 is more preferable.
If the bromine atom content ratio to the radiation heat transfer inhibitor is less than 0.15, the flame retardancy effect tends to be difficult to be exhibited. If it exceeds 2.0, the flame retardancy effect is manifested. Further, deterioration of the styrene-based resin is likely to be induced, which may cause a decrease in mechanical properties of the obtained foamed molded article and is disadvantageous in terms of cost.

  In the expandable styrene resin particles of the present invention, the 1% weight reduction temperature in the thermogravimetric analysis of the brominated flame retardant-containing mixture can be controlled by using a heat stabilizer in combination.

  The heat stabilizer in the present invention can be used in appropriate combination according to the styrene resin used, the foaming agent species and content, the radiation heat transfer inhibitor species and content, the brominated flame retardant species and content. .

As the heat stabilizer used in the present invention, for example,
Triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis {3- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate}, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-t-butyl-4-hydroxyphenyl) propionate, 3,5-di-t- Butyl-4-hydroxy-benzyl phosphate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydride Kishibenjiru) benzene, tris (3,5-di -t- butyl-4-hydroxybenzyl) hindered phenolic compounds such as isocyanurate late;
2,2,6,6-tetramethyl-4-piperidyl stearate, 1,2,2,6,6-pentamethyl-4-piperidyl stearate, 2,2,6,6-tetramethyl-4-piperidyl benzoate Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2- (tris (2,2 , 6,6-tetramethylpiperidyloxycarbonyl) butylcarbonyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, bis (2- (tris (1 , 2,2,6,6-pentamethylpiperidyloxycarbonyl) butylcarbonyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [ .5] undecane, bis (2,2,6,6-tetramethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6 , 6-Pentamethyl-4-piperidyl) -di (tridecyl) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) -2-butyl 2- (3,5-di-tert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol / diethyl succinate polycondensation 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / dibromoethane polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4 -Piperidylamino Hexane / 2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane / 2,4-dichloro-6 -T-octylamino-s-triazine polycondensate, tetrakis (2,2,6,6-tetramethylpiperidyloxycarbonyl) butane, tetrakis (1,2,2,6,6-pentamethylpiperidyloxycarbonyl) butane 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (2,2,6,6-tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,5,8,12-tetrakis [2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4- Piperidyl) Ami F) -s-triazin-6-yl] -1,5,8,12-tetraazadodecane, 1,6,11-tris [2,4-bis (N-butyl-N- (2,2,6) , 6-Tetramethyl-4-piperidyl) amino) -s-triazin-6-yl] aminoundecane 1,6,11-tris [2,4-bis (N-butyl-N- (1,2,2, Hindered amine compounds such as 6,6-pentamethyl-4-piperidyl) amino) -s-triazin-6-yl] aminoundecane;
Trisnonylphenyl phosphite, tris [2-tert-butyl-4- (3-tert-butyl-4-hydroxy-5-methylphenylthio) -5-methylphenyl] phosphite, tridecyl phosphite, octyldiphenylphos Phyto, di (decyl) monophenyl phosphite, di (tridecyl) pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, Bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite, bis (2,4-dicumyl) Phenyl) pentaerythritol diphosphite, Tora (tridecyl) isopropylidene diphenol diphosphite, tetra (tridecyl) -4,4′-n-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3- Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butanetriphosphite, tetrakis (2,4-di-t-butylphenyl) biphenylene diphosphonite, 9,10-dihydro-9-oxa-10- Phosphophenanthrene-10-oxide, 2,2'-methylenebis (4,6-t-butylphenyl) -2-ethylhexyl phosphite, 2,2'-methylenebis (4,6-t-butylphenyl)- Octadecyl phosphite, 2,2'-ethylidenebis (4,6-di-t-butylphenyl) fluor Phosphite, tris (2-[(2,4,8,10-tetrakis-t-butyldibenzo [d, f] [1,3,2] dioxaphosphin-6-yl) oxy] ethyl) amine, Phosphorus compounds such as phosphite of 2-ethyl-2-butylpropylene glycol and 2,4,6-tri-t-butylphenol;
Amine compounds such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer, alkylated diphenylamine, octylated diphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, 3,3- Sulfur compounds such as thiobispropionic acid didecyl ester, 3,3'-thiobispropionic acid dioctadecyl ester, bisphenol A diglycidyl ether type epoxy resin, brominated bisphenol A diglycidyl ether type epoxy resin, cresol novolac type epoxy Examples thereof include epoxy compounds such as resins and phenol novolac type epoxy resins.
These heat stabilizers can be used alone or in admixture of two or more.

  Among these heat stabilizers, a hindered amine compound, a phosphorus compound, and an epoxy compound are preferable because the 1% weight reduction temperature in the thermogravimetric analysis of the brominated flame retardant-containing mixture can be arbitrarily controlled.

  The content and addition amount of the heat stabilizer in the foamable styrene resin particles in the present invention are preferably 0.1 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the brominated flame retardant, It is more preferably 0.3 parts by weight or more and 8 parts by weight or less, and further preferably 0.5 parts by weight or more and 6 parts by weight or less.

In the present invention, the brominated flame retardant and the heat stabilizer can be melt-kneaded with the styrene resin as they are in the production method described later, but usually a masterbatch with the styrene resin is prepared in consideration of dispersibility and the like. The master batch and the styrene resin are preferably melt-kneaded.
The master batch includes 50% by weight or more and 70% by weight or less of a styrene resin and 30% by weight or more and 50% by weight or less of a mixture of a brominated flame retardant and a heat stabilizer (the total amount of both is 100% by weight). It is preferable that the styrene-based resin is 55% by weight or more and 65% by weight or less and the mixture of the brominated flame retardant and the heat stabilizer is 35% by weight or more and 45% by weight or less.
The dispersibility of the mixture of the brominated flame retardant and the thermal stabilizer is excellent when the ratio of the mixture of the brominated flame retardant and the thermal stabilizer in the masterbatch is 30% by weight or more and 50% by weight or less. Excellent flame retardancy can be obtained with a low addition amount.

  In the expandable styrene resin particles of the present invention, by further containing a radical generator, the 1% weight loss temperature in thermogravimetric analysis of brominated flame retardants can be controlled by using in combination with brominated flame retardants. The styrenic resin to be used, the foaming agent type and content, the radiant heat transfer inhibitor type and content, the brominated flame retardant type and content can be used in appropriate combinations. Examples of the radical generator include cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane, and the like.

  In the present invention, the content and addition amount of the radical generator in the expandable styrene resin particles are preferably 0.05 parts by weight or more and 1.0 part by weight or less with respect to 100 parts by weight of the styrene resin.

In the expandable styrenic resin particles of the present invention, if necessary,
Processing aids such as sodium stearate, magnesium stearate, calcium stearate, zinc stearate, barium stearate, liquid paraffin;
In addition to the hindered amines, phosphorus stabilizers, and epoxy compounds described above, phenolic antioxidants, nitrogen stabilizers, sulfur stabilizers, light-resistant stabilizers such as benzotriazoles, antistatic agents, and colorants such as pigments Additives such as;
Silica, calcium silicate, wollastonite, kaolin, clay, mica, zinc oxide, calcium carbonate, sodium hydrogen carbonate and other inorganic compounds, methyl methacrylate copolymer, polyethylene wax, olefin wax, talc, methylene Nucleating agents such as bisstearyl amide, ethylene bisstearyl amide, hexamethylene bispalmitic acid amide, fatty acid bisamide such as ethylene bisoleic acid amide, ethylene-vinyl acetate copolymer resin;
Foaming of aromatic organic compounds such as styrene, toluene, ethylbenzene and xylene, cycloaliphatic hydrocarbons such as cyclohexane and methylcyclohexane, solvents such as ethyl acetate and butyl acetate having a boiling point of 200 ° C. or less under atmospheric pressure An auxiliary agent may be contained.

  The method for producing the expandable styrene resin particles of the present invention is preferably a method obtained by melt-kneading a styrene resin and various compounds using an extruder and then cutting into particles, and the following two methods are used. Can be mentioned.

That is, as the first manufacturing method,
3 to 10 parts by weight of a foaming agent comprising at least one hydrocarbon having 3 to 6 carbon atoms, 1 to 6 parts by weight of a radiation heat transfer inhibitor, and 1 in thermogravimetric analysis with respect to 100 parts by weight of a styrene resin. 0.5 to 6 parts by weight of a brominated flame retardant having a% weight reduction temperature of 210 ° C. to 280 ° C. and a bromine content of 60% by weight or more and less than 70% by weight, if necessary, radical generation 0.05 to 1.0 parts by weight of the agent, 0.1 to 10 parts by weight of the heat stabilizer with respect to 100 parts by weight of the brominated flame retardant, and further melt and knead other additives as necessary. Then, after cooling to a predetermined temperature, it is extruded into a cutter chamber filled with pressurized circulating water through a die having a small hole, and immediately after extrusion, it is cut with a rotary cutter and cooled and solidified with pressurized circulating water. To obtain expandable styrene resin particles The weight ratio of the radiation heat transfer inhibitor content in the expandable styrene resin particles and the bromine content derived from the brominated flame retardant is 1 / 0.15 to 1 / 2.0. And a method for producing expandable styrene resin particles.

In the first production method, the temperature of the resin in the melt kneading part of the extruder is preferably 160 ° C to 250 ° C. Moreover, it is preferable that the residence time in an extruder from supplying a styrene resin and various compounds to an extruder until the end of melt-kneading is 7 minutes or less.
When the resin temperature is higher than 250 ° C. and / or when the residence time in the extruder until melting and kneading is longer than 7 minutes, the brominated flame retardant may be decomposed, and the desired flame retardancy is obtained. It cannot be obtained or must be added in excess to impart the desired flame retardancy.
On the other hand, when the resin temperature is lower than 160 ° C., the load on the extruder becomes large and the extrusion may become unstable, or the dispersibility of the material to be added may deteriorate. In addition, if the resin is extruded through a die immediately after melting and kneading, the shearing strain and elongation strain of the molten resin increase, and the resulting resin particles may become distorted. When the shape of the obtained expandable resin particles is not good, it may cause deterioration of moldability.

  Here, the melt kneading part of the extruder means from the feed part to the tip of the extruder when it is composed of one extruder having a single screw or a twin screw, and in the case of a tandem extruder. It means from the feed section of the first extruder to the tip of the second extruder.

  In the extruder, the foaming agent, radiant heat transfer inhibitor, brominated flame retardant, and other additives such as heat stabilizer and nucleating agent are dissolved or uniformly dispersed in the styrene resin as appropriate. The melt-kneaded product cooled to a certain temperature is extruded into pressurized cooling water from a die having a plurality of small holes.

  The die used in the present invention is not particularly limited, and examples thereof include those having a small hole having a diameter of 0.3 mm to 2.0 mm, preferably 0.4 mm to 1.0 mm.

In the first production method, the temperature of the melt-kneaded product immediately before being extruded from the die is the glass transition temperature of the thermoplastic resin in a state not containing the foaming agent + 40 ° C. to 100 ° C., more preferably the glass transition temperature + 50 ° C. It is preferable to cool to -70 degreeC.
If the temperature of the melt-kneaded product immediately before being extruded from the die is lower than the glass transition temperature + 40 ° C., the viscosity of the discharged resin is too high and clogged with small holes, which is obtained due to a decrease in the substantially small hole opening ratio. The resin particles that are produced may be deformed. On the other hand, when the temperature of the melt-kneaded product immediately before being extruded from the die is higher than the glass transition temperature + 100 ° C., the discharge resin is not completely solidified and foams, or the viscosity of the discharge resin is too low. In some cases, it cannot be stably discharged into the pressurized cooling water, and the substantial aperture ratio of the small holes may decrease.

  The cutting device that cuts the resin extruded into the circulating pressurized cooling water in the first manufacturing method is not particularly limited. For example, the cutting device is cut by a rotary cutter that contacts the die lip to be spheroidized, and pressurized circulating cooling is performed. Examples include a device that is transported to a centrifugal dehydrator and dewatered and collected without foaming the water.

As a production method of the second expandable styrene resin particles,
1 to 6 parts by weight of radiant heat transfer inhibitor with respect to 100 parts by weight of styrenic resin, 1% weight reduction temperature in thermogravimetric analysis is 210 ° C. to 280 ° C., and bromine content is 60% by weight or more, 0.5 to 6 parts by weight of a brominated flame retardant that is less than 70% by weight, 0.05 to 1.0 parts by weight of a radical generator and 100 parts by weight of a thermal stabilizer as necessary. On the other hand, 0.1 to 10 parts by weight, and if necessary, other additives are melt-kneaded with an extruder, extruded through a die having a small hole, and then cut with a cutter to obtain styrenic resin particles. After
Suspending the styrene resin particles in water and supplying an amount of 3 to 10 parts by weight of a foaming agent comprising at least one hydrocarbon having 3 to 6 carbon atoms with respect to 100 parts by weight of the styrene resin Then, a production method for obtaining expandable styrene resin particles,
Foam, wherein the weight ratio of the radiation heat transfer inhibitor content in the expandable styrenic resin particles to the bromine content derived from the brominated flame retardant is from 1 / 0.15 to 1 / 2.0 For example, a method for producing a conductive styrene resin particle.

  As an extruder used by the 2nd manufacturing method, the thing similar to what was described by the said manufacturing method can be used.

The temperature of the resin in the melt kneading part of the extruder in the second production method is preferably 160 ° C to 250 ° C. Moreover, it is preferable that the residence time in an extruder from supplying a material to an extruder until the end of melt-kneading is 7 minutes or less.
When the resin temperature is higher than 250 ° C. and / or when the residence time in the extruder until the end of melt-kneading is longer than 7 minutes, the same problem as described in the explanation of the first production method may occur. . On the other hand, when the resin temperature is lower than 160 ° C., in addition to the same problem as described in the explanation of the first production method, when the resin is extruded through a die immediately after melt kneading, the shear strain and elongation of the molten resin Since the strain increases, the resulting resin particles become distorted, the degree of particle sticking and flattening increases during the foaming agent impregnation process, the process becomes unstable, and the process is prolonged and productivity is significantly reduced. In some cases.

  The expandable styrenic resin particles obtained as described above are cured in a mold for a certain period of time through a conventionally known preliminary foaming process, for example, a process of foaming 10 to 110 times with heated steam. Thus, for example, it is possible to obtain a foamed molded product foamed 10 to 110 times.

The density of the styrene resin foam molded article of the present invention is preferably 5 to 50 kg / m ^{3 and} more preferably 8 to 40 kg / m ³ from the viewpoint of achieving both heat insulation and flame retardancy.

  The average cell diameter in the styrenic resin foam molded article of the present invention is preferably 0.02 to 1.50 mm, more preferably 0.05 to 0.50 mm from the viewpoint of heat insulation.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but is not limited thereto.

  The examples and comparative examples were evaluated by the following methods.

(1) Thermogravimetric analysis of brominated flame retardants and brominated flame retardant-containing mixtures:
A sample of 5 mg was weighed and heated from 30 ° C. to 350 ° C. at a rate of temperature increase of 10 ° C./min using a differential thermal and thermogravimetric simultaneous measurement apparatus [manufactured by Shimadzu Corporation, DTG-60A]. A 1% weight loss temperature was measured.

(2) Content of radiant heat transfer inhibitor in expandable styrene resin particles:
In accordance with JIS K6226-2: 2003, graphite in the expandable styrene resin particles was quantified.
On the other hand, Ti in the expandable styrene-based resin particles was quantified by ICP-AES method, and converted to titanium oxide (TiO ₂ ) to obtain the content of titanium oxide.

(3) Bromine content in expandable styrene resin particles:
After 5 mg of the expandable styrene resin particles were precisely weighed, it was adjusted to 25 ml with ultrapure water. The ion chromatograph was measured under the following conditions to measure the bromine content in the expandable styrene resin particles.
Measuring equipment: ICS-2000 made by Dionex
Column: IonPac AG18, AS18 (4mmφ × 250mm)
Eluent: KOH gradient Eluent flow rate: 1.0 ml / min Sample injection volume: 50 μL
Detector: Electrical conductivity detector (4) Formability evaluation method In-mold molding was carried out under the conditions of the examples and comparative examples, and the obtained foamed molded products were visually evaluated according to the following criteria.
○: Foam molding in which there is no sink, melt, shrinkage, etc. in the foamed molded body, there are few gaps between the foamed particles on the surface of the molded body, the surface is smooth, and over 80% of the fused beads break the material on the fracture surface when the molded body is broken. The body was obtained.
X: Sink, melt, shrinkage, etc. occur in the foam molded product, the foam particle gap on the surface of the molded product is large, or less than 80% of the fused beads break the material on the fracture surface when the molded product is broken. A foamed molded product that was either of these was obtained.

(5) Measuring method of expansion ratio of styrene resin foam molding:
The dimension of the obtained foaming molding was measured, the volume was calculated | required, and it calculated | required by the following formula from the weight and the volume.
Expansion ratio = volume / weight of expanded particles (g)
(6) Method of measuring thermal conductivity of styrene resin foam molded article A plate having a length of 200 mm, a width of 200 mm and a thickness of 25 mm was cut out from the obtained foamed molded article and treated at 50 ° C. for 24 hours. The thermal conductivity at an average temperature of 20 ° C. was measured using a conductivity measuring device [manufactured by Eihiro Seiki Co., Ltd., HC-072].

(7) Evaluation method of flame retardancy of styrenic resin foam molding <self-extinguishing>
The obtained foamed molded product was allowed to stand in a 50 ° C. atmosphere for 24 hours, and then evaluated according to JIS A9511 (foamed plastic heat insulating material) measuring method A.
○: Fire extinguishing time is within 3 seconds.
X: Fire extinguishing time exceeded 3 seconds, or did not extinguish.
<Minimum oxygen index [LOI]>
The obtained foamed molded product was allowed to stand in an atmosphere of 50 ° C. for 24 hours, and then evaluated according to JIS K7201.

(8) Measuring method of residual ratio of flame retardant in expandable styrene resin particles After dissolving about 40 mg of the obtained foamed molded product in 2 ml of chloroform, 2 ml of methanol was added to reprecipitate only the resin component, and then the solution Was filtered through a 0.45 μm PTFE filter.
Subsequently, the flame retardant in the prepared filtrate was quantified using the following high performance liquid chromatograph (HPLC) which calibrated each flame retardant pure component used as a standard sample.
Apparatus: Shimadzu Corporation HPLC HPLC
Column: Thermo HYPERCARB 5 μm (50 × 2.1 mm)
Column temperature: 40 ° C
Mobile phase: chloroform / methanol = 50/50 (v / v)
Flow rate: 0.5 mL / min Detection: UV 254 nm, 210 nm
Sample injection volume: 10 μL
Analysis time: 20 minutes In the examples and comparative examples, the following raw materials were used.
<Styrene resin>
(A1) Polystyrene homopolymer [PS940, G9401]
(A2) Polystyrene homopolymer [PS Japan Co., Ltd., 680]
<Foaming agent>
(B1) Normal pentane [Wako Pure Chemical Industries, Ltd., reagent product]
(B2) Isopentane [Wako Pure Chemical Industries, Ltd., reagent product]
<Radiation heat transfer inhibitor>
(C1) Graphite [manufactured by Ito Graphite Industry Co., Ltd., scaly graphite Z-5F]
(C2) Titanium dioxide [manufactured by Sakai Chemical Industry Co., Ltd., R-7E]
<Brominated flame retardant>
(D1) 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane [Daiichi Kogyo Seiyaku Co., Ltd., SR-130: 1% weight reduction Temperature = 231 ° C., bromine content = 66 wt%]
(D2) Brominated styrene / butadiene copolymer [Chemtura, Emerald 3000: 1% weight loss temperature = 243 ° C., bromine content = 65% by weight]
(D3) 2,2-bis [4- (2,3-dibromopropoxy) -3,5-dibromophenyl] propane [Daiichi Kogyo Seiyaku Co., Ltd., SR-720: 1% weight loss temperature = 272 ° C. , Bromine content = 68 wt%]
(D4) Tris (2,3-dibromopropyl) isocyanurate [manufactured by Nippon Kasei Co., Ltd., TAIC-6B, 1% weight loss temperature = 256 ° C., bromine content = 66% by weight]
(D5) 2,2-bis [4-allyloxy-3,5-dibromophenyl] propane [manufactured by Teijin Chemicals Ltd., FG-3200: 1% weight reduction temperature = 198 ° C., bromine content = 51% by weight]
(D6) Tris (tribromoneopentyl) phosphate [manufactured by Daihachi Chemical Industry Co., Ltd., CR-900: 1% weight loss temperature = 289 ° C., bromine content = 70% by weight]
(D7) Tetrabromocyclooctane [Daiichi Kogyo Seiyaku Co., Ltd., FR200: 1% weight reduction temperature = 155 ° C., bromine content = 75% by weight]
<Heat stabilizer>
(E1) Tetrakis (2,2,6,6-tetramethylpiperidyloxycarbonyl) butane (E2) bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite [Chemtura, Ultranox 626 ]
(E3) Cresol novolac-type epoxy resin [manufactured by Araldite, ECN-1280]
(Radical generator)
(F1) 2,3-dimethyl-2,3-diphenylbutane [manufactured by NOF Corporation, NOFMER BC]
<A mixture of brominated flame retardant and heat stabilizer>
(G1) 3 parts by weight of heat stabilizer (E1) and 2 parts by weight of (E2) were mixed with 100 parts by weight of brominated flame retardant (D1). The 1% weight reduction temperature of the brominated flame retardant (D1) -containing mixture was 248 ° C.
(G2) 10 parts by weight of heat stabilizer (E3) and 5 parts by weight of (E2) were mixed with 100 parts by weight of brominated flame retardant (D2). The 1% weight reduction temperature of the brominated flame retardant (D2) -containing mixture was 255 ° C.
<Others>
(H1) Talc [Made by Hayashi Kasei Co., Ltd., Talcan powder PK-Z]
<Masterbatch of a mixture of brominated flame retardant and heat stabilizer>
(I1) After supplying 100 parts by weight of polystyrene homopolymer (A2) to a twin-screw extruder and melt-kneading, 73 parts by weight of a mixture (G1) of a brominated flame retardant and a thermal stabilizer is supplied from the middle of the extruder. And further melt-kneaded. A strand-like resin extruded at a discharge rate of 300 kg / hour through a die having a small hole attached to the tip of the extruder is cooled and solidified in a 20 ° C. water tank, and then cut to obtain a brominated flame retardant and a thermal stabilizer. A master batch of the mixture with was obtained. At this time, the setting temperature of the extruder was 170 ° C. The brominated flame retardant content in the masterbatch was 40% by weight.
(I2) After supplying 100 parts by weight of polystyrene homopolymer (A2) to a twin screw extruder and melt-kneading, 100 parts by weight of a mixture (G2) of a brominated flame retardant and a heat stabilizer is supplied from the middle of the extruder. And further melt-kneaded. The strand-shaped resin extruded at a discharge rate of 300 kg / hour through a die having a small hole attached to the end of the extruder is cooled and solidified in a 20 ° C. water tank, and then cut to obtain a brominated flame retardant and a thermal stabilizer. A master batch of the mixture was obtained. At this time, the setting temperature of the extruder was 170 ° C. The brominated flame retardant content in the masterbatch was 43% by weight.
<Master batch of radiant heat transfer inhibitor>
(J1) A Banbury mixer was charged with 100 parts by weight of polystyrene homopolymer (A2) and 67 parts by weight of a radiant heat transfer inhibitor (C1), melted and kneaded at a set temperature of 220 ° C. for 10 minutes, and then supplied to a ruder. The strand-like resin extruded at a discharge rate of 300 kg / hour through a die having a small hole attached to the tip was cooled and solidified in a 20 ° C. water bath, and then cut to obtain a master batch.
The brominated flame retardant content in the masterbatch was 40% by weight.

Example 1
[Production of expandable styrene resin particles]
3.2 parts by weight of a mixture (G1) of a brominated flame retardant and a heat stabilizer, 2 parts by weight of a radiant heat transfer inhibitor (C1), and talc (H1) 0 per 100 parts by weight of the styrene resin (A1) 2 parts by weight were put into a blender and blended for 10 minutes to obtain a resin composition.
The obtained resin composition is supplied to a tandem type two-stage extruder in which a single screw extruder (first extruder) having a diameter of 65 mm and a single screw extruder (second extruder) having a diameter of 90 mm are connected in series. Melt kneading was performed at a set temperature of 220 ° C. in a 65 mm extruder. 7 parts by weight of isopentane was press-fitted into 100 parts by weight of styrene resin from the middle of a 65 mm diameter extruder (first extruder). Then, it supplied to the 90-mm-diameter extruder (2nd extruder) through the continuation pipe | tube set to 230 degreeC. After cooling the molten resin to 167 ° C. with a 90 mm diameter extruder (second extruder), the diameter is 0.7 mm and the land length is 3.0 mm attached to the tip of the second extruder set at 275 ° C. A die lip having 40 small holes was extruded into pressurized circulating water at a temperature of 60 ° C. and 1.0 MPa at a discharge rate of 50 kg / hour. The extruded molten resin is cut and granulated under a condition of 3400 rpm using a rotary cutter having 10 blades in contact with the die lip, transferred to a centrifugal dehydrator, and recovered as expandable styrene resin particles. It was done. At this time, the residence time in the first extruder was 4 minutes.
[Production of expanded styrene resin particles]
After dry blending 0.1 parts by weight of zinc stearate with respect to 100 parts by weight of the obtained expandable styrenic resin particles, it was put into a pre-foaming machine [manufactured by Daikai Kogyo Co., Ltd., BHP-300], and 0.08 MPa. The water vapor was introduced into a pre-foaming machine and foamed to obtain expanded styrene resin particles having an expansion ratio of 70 times.
[Production of foamed molded product]
The obtained expanded styrenic resin particles were filled into an in-mold mold (445 mm × 295 mm × 25 mm) attached to an expanded polystyrene molding machine [manufactured by Daisen Kogyo Co., Ltd., KR-57]. Was introduced to obtain a styrenic foam molded body having a beautiful rectangular parallelepiped appearance.
The evaluation results of the obtained foamed molded product are shown in Table 1.
(Example 2)
[Production of expandable styrene resin particles]
7 parts by weight of a master batch (I2) of a mixture of a brominated flame retardant and a heat stabilizer and 10 parts by weight of a radiant heat transfer inhibitor master batch (J1) with respect to 90.5 parts by weight of the styrene resin (A2) Then, 0.2 part by weight of talc (H1) was put into a blender and blended for 10 minutes to obtain a resin composition.
The obtained resin composition is supplied to a tandem type two-stage extruder in which a single screw extruder (first extruder) having a diameter of 65 mm and a single screw extruder (second extruder) having a diameter of 90 mm are connected in series. Melt kneading was performed at a set temperature of 220 ° C. in a 65 mm extruder. 7 parts by weight of mixed pentane (a mixture of 80% normal pentane and 20% isopentane) was pressed into 100 parts by weight of the styrene resin from the middle of the 65 mm diameter extruder (first extruder). Then, it supplied to the 90-mm-diameter extruder (2nd extruder) through the continuation pipe | tube set to 230 degreeC. After cooling the molten resin to 167 ° C. with a 90 mm diameter extruder (second extruder), the diameter is 0.7 mm and the land length is 3.0 mm attached to the tip of the second extruder set at 275 ° C. A die lip having 40 small holes was extruded into pressurized circulating water at a temperature of 60 ° C. and 1.0 MPa at a discharge rate of 50 kg / hour. The extruded molten resin is cut and granulated under a condition of 3400 rpm using a rotary cutter having 10 blades in contact with the die lip, transferred to a centrifugal dehydrator, and recovered as expandable styrene resin particles. It was done. At this time, the residence time in the first extruder was 4 minutes.
[Production of expanded styrene resin particles]
After dry blending 0.1 parts by weight of zinc stearate with respect to 100 parts by weight of the obtained expandable styrenic resin particles, it was put into a pre-foaming machine [manufactured by Daikai Kogyo Co., Ltd., BHP-300], and 0.08 MPa. The water vapor was introduced into a pre-foaming machine and foamed to obtain expanded styrene resin particles having an expansion ratio of 70 times.
[Production of foamed molded product]
The obtained expanded styrenic resin particles were filled into an in-mold mold (445 mm × 295 mm × 25 mm) attached to an expanded polystyrene molding machine [manufactured by Daisen Kogyo Co., Ltd., KR-57]. Was introduced to obtain a styrenic foam molded body having a beautiful rectangular parallelepiped appearance.
The evaluation results of the obtained foamed molded product are shown in Table 1.

(Example 3)
[Production of styrene resin particles]
6.7 parts by weight of a master batch (I1) of a mixture of a brominated flame retardant and a heat stabilizer, 10 parts by weight of a radiant heat transfer inhibitor master batch (J1) with respect to 89.98 parts by weight of the styrene resin (A2) And 0.2 parts by weight of talc (H1) are supplied to a φ90 mm single screw extruder, melt-kneaded in the extruder, and passed through a die provided with 140 small holes with a diameter of 1.4 mm attached to the tip of the extruder. The strand-shaped resin extruded at a discharge rate of 335 kg / hour was cooled and solidified in a water bath at 20 ° C., and then styrene resin particles were obtained with a strand cutter. At this time, the temperature of the resin at the tip of the extruder was 245 ° C., and the residence time in the extruder was 3 minutes.
[Production of expandable styrene resin particles]
Subsequently, 200 parts by weight of deionized water, 1 part by weight of tricalcium phosphate, 0.03 parts by weight of sodium dodecylbenzenesulfonate are added to 100 parts by weight of the obtained styrene resin particles in an autoclave with a stirrer having a volume of 6 L. Then, 1 part by weight of sodium chloride was added to seal the pressure vessel. Thereafter, the mixture was heated to 105 ° C over 1 hour, and 8 parts by weight of mixed pentane (a mixture of 80% normal pentane and 20% isopentane) was added to the pressure vessel over 30 minutes as a blowing agent, and then over 10 minutes to 115 ° C. The temperature was raised and maintained for 4 hours. After holding, cool to room temperature, take out the resin particles impregnated with the blowing agent from the autoclave, pickle with hydrochloric acid, wash with water, dehydrate with a centrifuge, and remove moisture adhering to the surface of the resin particles with an air dryer. Dried.
[Production of expanded styrene resin particles]
After dry blending 0.1 parts by weight of zinc stearate with respect to 100 parts by weight of the obtained expandable styrenic resin particles, it was put into a pre-foaming machine [manufactured by Daikai Kogyo Co., Ltd., BHP-300], and 0.08 MPa. The water vapor was introduced into a pre-foaming machine and foamed to obtain expanded styrene resin particles having an expansion ratio of 70 times.
[Production of foamed molded product]
The obtained expanded styrenic resin particles were filled into an in-mold mold (445 mm × 295 mm × 25 mm) attached to an expanded polystyrene molding machine [manufactured by Daisen Kogyo Co., Ltd., KR-57]. Was introduced to obtain a styrenic foam molded body having a beautiful rectangular parallelepiped appearance.
The evaluation results of the obtained foamed molded product are shown in Table 1.

Example 4
In [Preparation of Styrenic Resin Particles], 5.7 parts by weight of a master batch (I2) of a mixture of a brominated flame retardant and a heat stabilizer with respect to 91.15 parts by weight of the styrene resin (A2), radiation transmission Except for using 10 parts by weight of the heat-inhibitor master batch (J1) and 0.2 parts by weight of talc (H1), the same procedure as in Example 3 was followed, except that expandable styrene resin particles and expanded styrene resin were used. Resin particles and a foam-molded article were prepared to obtain a styrenic foam-molded article having a beautiful rectangular parallelepiped shape.
The evaluation results of the obtained foamed molded product are shown in Table 1.

(Example 5)
In [Production of Styrenic Resin Particles], 3.2 parts by weight of a mixture (G1) of a brominated flame retardant and a thermal stabilizer, and a radiation heat transfer inhibitor (C1) with respect to 100 parts by weight of the styrene resin (A2) ) Expandable styrenic resin particles, foamed in the same manner as in Example 3 except that 2 parts by weight, 2 parts by weight of the radiation heat transfer inhibitor (C2) and 0.2 parts by weight of talc (H1) were used. Styrene-based resin particles and a foam-molded product were produced to obtain a rectangular solid-shaped styrene-based foam-molded product.
The evaluation results of the obtained foamed molded product are shown in Table 1.

(Example 6)
In [Production of Styrenic Resin Particles], 2 parts by weight of a mixture (G1) of a brominated flame retardant and a heat stabilizer, 100 parts by weight of the styrene resin (A2), a radiation heat transfer inhibitor (C1) 2 The same operation as in Example 3 except that parts other than parts by weight, 2 parts by weight of the radiation heat transfer inhibitor (C2), 0.2 parts by weight of talc (H1), and 0.5 parts by weight of the radical generator (F1) were used. Thus, expandable styrene-based resin particles, expanded styrene-based resin particles, and a foam-molded product were produced, and a rectangular solid-shaped styrene-based foam-molded product having a beautiful appearance was obtained.
The evaluation results of the obtained foamed molded product are shown in Table 1.

(Example 7)
In [Production of Styrenic Resin Particles], 3 parts by weight of brominated flame retardant (D3), 4 parts by weight of radiant heat transfer inhibitor (C1), talc (H1) with respect to 100 parts by weight of styrene resin (A2) ) A foamed styrene resin particle, a foamed styrene resin particle, and a foamed molded product were produced by the same operation as in Example 3 except that the components other than 0.2 parts by weight were used. A foamed molded product was obtained.
The evaluation results of the obtained foamed molded product are shown in Table 1.

(Example 8)
In [Production of styrene resin particles], 3 parts by weight of brominated flame retardant (D4), 4 parts by weight of radiant heat transfer inhibitor (C1), talc (H1) with respect to 100 parts by weight of styrene resin (A2) ) Except that 0.2 parts by weight were used, expandable styrene resin particles, expanded styrene resin particles, and foamed molded articles were produced in the same manner as in Example 3, and the appearance of a beautiful cuboid styrene foam A molded body was obtained.
The evaluation results of the obtained foamed molded product are shown in Table 1.

(Comparative Example 1)
In [Production of Styrenic Resin Particles], 3.2 parts by weight of a mixture (G1) of a brominated flame retardant and a heat stabilizer and 0.2% of talc (H1) with respect to 100 parts by weight of styrene resin (A1). Except for parts by weight, expandable styrene resin particles, expanded styrene resin particles, and a foam molded body were produced in the same manner as in Example 1 to obtain a rectangular solid styrene foam molded body having a beautiful appearance.
The evaluation results of the obtained foamed molded product are shown in Table 2. Since no radiation heat transfer inhibitor is added, it can be seen that the thermal conductivity is higher than in the examples.

(Comparative Example 2)
In [Production of Styrenic Resin Particles], 6.7 parts by weight of a master batch (I1) of a mixture of a brominated flame retardant and a thermal stabilizer, 96 parts by weight of styrene resin (A2), talc (H1) Except for 0.2 parts by weight, expandable styrenic resin particles, expanded styrene resin particles, and a foamed molded product are produced in the same manner as in Example 3 to obtain a rectangular solid styrenic foamed molded product. It was. The evaluation results of the obtained foamed molded product are shown in Table 2. Since no radiation heat transfer inhibitor is added, it can be seen that the thermal conductivity is higher than in the examples.

(Comparative Example 3)
In [Production of Styrenic Resin Particles], 7 parts by weight of a mixture (G1) of a brominated flame retardant and a heat stabilizer, 100 parts by weight of styrene resin (A1), radiation heat transfer inhibitor (C1) 2 Expandable styrene-based resin particles, expanded styrene-based resin particles, and a foam-molded article were produced in the same manner as in Example 1 except that 0.2 parts by weight of talc (H1) was used. However, melt, shrinkage, etc. occurred, and a cuboid styrene foam molded article having a beautiful appearance could not be obtained. The evaluation results of the obtained foamed molded product are shown in Table 2. Since the radiant heat transfer inhibitor content / bromine content is outside the scope of the present invention, the flame retardancy is satisfied, but the moldability is poor.

(Comparative Example 4)
In [Preparation of Styrenic Resin Particles], 2 parts by weight of master batch (I1) of a mixture of a brominated flame retardant and a heat stabilizer with respect to 92.8 parts by weight of styrene resin (A2), suppression of radiant heat transfer Expandable styrene resin particles, expanded styrene resin particles, and expanded molded article by the same operations as in Example 3 except that 10 parts by weight of the agent master batch (J1) and 0.2 parts by weight of talc (H1) were used. To obtain a styrenic foamed molded article having a beautiful rectangular parallelepiped shape.
The evaluation results of the obtained foamed molded product are shown in Table 2. Since the radiant heat transfer inhibitor content / bromine content was outside the scope of the present invention, the flame retardancy was not sufficient.

(Comparative Example 5)
In [Production of Styrenic Resin Particles], 89.5 parts by weight of the styrene resin (A2), 2.5 parts by weight of a master batch (I1) of a mixture of a brominated flame retardant and a heat stabilizer, radiation transmission Except for using 15 parts by weight of heat inhibitor masterbatch (J1) and 0.2 parts by weight of talc (H1), expandable styrene resin particles, expanded styrene resin particles, foamed by the same operation as in Example 3. A molded body was produced, and a cuboid styrene foam molded body having a beautiful appearance was obtained.
The evaluation results of the obtained foamed molded product are shown in Table 2. Since the radiant heat transfer inhibitor content / bromine content was outside the scope of the present invention, the flame retardancy was not sufficient.

(Comparative Example 6)
In [Production of Styrenic Resin Particles], 3 parts by weight of brominated flame retardant (D5), 4 parts by weight of radiant heat transfer inhibitor (C1), talc (H1) with respect to 100 parts by weight of styrene resin (A2) ) Styrenic resin particles were produced in the same manner as in Example 3 except that 0.2 parts by weight were used. However, the styrene resin was significantly deteriorated, and good particles were not obtained.

(Comparative Example 7)
In [Production of Styrenic Resin Particles], 3 parts by weight of brominated flame retardant (D6), 4 parts by weight of radiant heat transfer inhibitor (C1), talc (H1) with respect to 100 parts by weight of styrene resin (A2) ) Except that 0.2 parts by weight were used, expandable styrene resin particles, expanded styrene resin particles, and foamed molded articles were produced in the same manner as in Example 3, and the appearance of a beautiful cuboid styrene foam A molded body was obtained. The evaluation results of the obtained foamed molded product are shown in Table 2. Since the brominated flame retardant is outside the specified range of the present invention, sufficient flame retardancy cannot be obtained.

(Comparative Example 8)
In [Production of Styrenic Resin Particles], 3 parts by weight of brominated flame retardant (D7), 4 parts by weight of radiant heat transfer inhibitor (C1), talc (H1) with respect to 100 parts by weight of styrene resin (A2) ) Expandable styrene resin particles, expanded styrene resin particles, and expanded molded articles were produced in the same manner as in Example 3 except that 0.2 parts by weight were used. However, melt and discoloration occurred, and a cuboid styrene foam molded article having a beautiful appearance could not be obtained.
The evaluation results of the obtained foamed molded product are shown in Table 2. Since the brominated flame retardant was outside the specified range of the present invention, flame retardancy was obtained, but the moldability was poor.

Claims (7)

In thermogravimetric analysis, 3 to 10 parts by weight of a blowing agent composed of at least one hydrocarbon having 3 to 6 carbon atoms, 1 to 6 parts by weight of a radiation heat transfer inhibitor, relative to 100 parts by weight of a styrene-based resin Expandable styrene resin particles containing 0.5 to 6 parts by weight of a brominated flame retardant having a 1% weight loss temperature of 210 ° C. to 280 ° C. and a bromine content of 60% by weight or more and less than 70% by weight Because
The bromine atom content / radiant heat transfer inhibitor content, which is the ratio of the bromine atom content derived from the brominated flame retardant to the radiation heat transfer inhibitor content in the expandable styrene resin particles, is 0.15 to 2. 0,
Furthermore, 0.1 to 10 parts by weight of a heat stabilizer is contained with respect to 100 parts by weight of the brominated flame retardant ,
Styrenic resin is (i) styrene homopolymer, (ii) styrene and styrene derivatives, polyfunctional vinyl compounds, (meth) acrylic acid ester compounds, vinyl cyanide compounds, diene compounds or their derivatives, unsaturated A copolymer with at least one monomer selected from the group consisting of a carboxylic acid anhydride and an N-alkyl-substituted maleimide compound, or a derivative thereof; (iii) the styrene homopolymer, and styrene; Or a copolymer blend with a derivative thereof, or (iv) the styrene homopolymer, and a homopolymer or copolymer blend of the monomer or derivative thereof, (v) styrene, A copolymer with a monomer or derivative thereof, and a homopolymer or copolymer blend of the monomer or derivative thereof, or (vi ) The styrene homopolymer, a copolymer of styrene and the monomer or derivative thereof, and a homopolymer or copolymer blend of the monomer or derivative thereof. , Expandable styrene resin particles. Relative to 100 parts by weight of a styrene resin, further characterized in that it contains 0.05 to 1.0 parts by weight of a radical generating agent, expandable styrene resin particles according to claim 1. The expandable styrenic resin according to claim 1 or 2 , wherein the radiation heat transfer inhibitor is at least one compound selected from the group consisting of graphite, graphene, activated carbon, carbon black and titanium oxide. particle. The brominated flame retardant is at least one compound selected from the group consisting of brominated bisphenol compounds, brominated isocyanurate compounds, and brominated styrene-butadiene copolymers. expandable styrene resin particles according to any one of 3. The foaming styrenic resin according to any one of claims 1 to 4 , wherein the foaming agent is at least one compound selected from the group consisting of normal pentane, isopentane, cyclopentane, and neopentane. particle. The foaming property according to any one of claims 1 to 5 , wherein the heat stabilizer is at least one compound selected from the group consisting of a hindered amine compound, a phosphorus compound, and an epoxy compound. Styrenic resin particles. The foamable styrenic resin particles according to any one of claims 1 to 6 are heated to be pre-foamed to obtain pre-foamed particles, which are then filled into a molding cavity and subjected to in-mold foam molding. A foamed molded article, characterized in that