JP2006131757A - Thermoplastic resin extrusion foam and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermoplastic resin foam exhibiting an excellent heat-insulating performance-retaining property. <P>SOLUTION: The thermoplastic resin extrusion foam exhibiting the excellent heat-insulating performance-retaining property is obtained by extrusion-foaming a thermoplastic resin comprised of a styrene resin and of a vinyl alcohol resin in the presence of a compound having a molecular weight of at most 1,000 and bearing at least one hydroxy group in the molecule. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermoplastic resin extruded foam having excellent heat insulation performance retention and a method for producing the same.

  A method for continuously producing a foam by melting a thermoplastic resin typified by a styrenic resin with an extruder or the like, then adding a foaming agent, cooling it, and extruding it into a low pressure region has already been made. Are known. The styrene resin extruded foam thus obtained is often used as a heat insulating material for houses and the like, and at that time, a high degree of heat insulation is required.

  On the other hand, measures for improving heat insulation have been performed such as improvement of closed cell ratio, control of bubble diameter and shape, addition of a radiation inhibitor such as carbon, use of low thermal conductivity foaming agent and the like.

  The thermal conductivity of the thermoplastic resin foam is the sum of four components: the thermal conductivity of the thermoplastic resin, the thermal conductivity of the gas in the bubble, the thermal conductivity by radiation, and the thermal conductivity by the convection of the gas in the bubble, Of these, the contribution of the thermal conductivity of the gas in the bubble is usually the largest. That is, in order to improve the thermal insulation of the thermoplastic resin foam, it is important to lower the thermal conductivity of the gas in the bubbles. For this reason, a gas having the lowest possible thermal conductivity is used as the foaming agent. It is desirable to contain air in the bubbles and to block the entry of air having a relatively high thermal conductivity into the bubbles. In styrenic resin foam, it was possible to improve the heat insulation immediately after production by using a low thermal conductivity gas as a foaming agent, but after that air gradually entered and the thermal conductivity of the gas inside the bubble increased. However, there was a tendency for the heat insulation to decrease (in the 25 mm thick extruded foam plate, the air partial pressure in the bubbles almost equilibrated with the atmospheric pressure in about 100 days after production).

  As a measure for improving the gas barrier property of the styrene resin foam, studies have been made to coat the styrene resin foam with a resin having a high gas barrier property (for example, Patent Documents 1 and 2). However, when used as a heat-insulating building material, cutting or nailing is performed at the construction site, so it was practically difficult to maintain the covering state and maintain the gas barrier property, that is, the high heat insulating property for a long time.

On the other hand, a foam in which a resin having a high gas barrier property is dispersed in a thermoplastic resin has been studied (for example, see Patent Documents 3 to 4). However, in Patent Document 3, only a preliminary study using a film is made for the thermoplastic resin, and in Patent Document 4, there is no exemplification regarding a styrene-based resin, and no specific explanation is given for the entire thermoplastic resin. Therefore, the present inventors examined using a thermoplastic resin composed of polystyrene and vinyl alcohol resin, and the foaming ratio was low in the system containing the foaming agent and additive shown in Patent Document 3 (foamed material). A problem such as a high density) and a low closed cell ratio occurred, and a foam with high heat insulating properties could not be obtained.
Japanese Examined Patent Publication No. 2-39382 JP 2002-144497 A Japanese National Patent Publication No. 5-505634 JP-A-8-319365

  Under such circumstances, the problem to be solved by the present invention is to provide a thermoplastic resin foam excellent in heat insulation performance retention.

  As a result of intensive studies to solve the above problems, the present inventors have determined that a thermoplastic resin comprising a styrene resin and a vinyl alcohol resin is a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule. The present inventors have found that a thermoplastic resin foam excellent in heat insulation performance retention can be obtained by extrusion foaming in the presence of the present invention, and have led to the present invention.

  That is, the present invention is characterized in that a thermoplastic resin comprising a styrene resin and a vinyl alcohol resin is extruded and foamed in the presence of a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule. It relates to a thermoplastic resin foam.

As a preferred embodiment,
(1) A part or all of the styrene resin is composed of a styrene resin having polarity,
(2) The styrenic resin having polarity is a styrene- (meth) acrylic acid copolymer,
(3) When the total amount of the styrene resin is 100% by weight, the styrene resin consists of 0% by weight to 99% by weight of polystyrene and 1% by weight to 100% by weight of the styrene- (meth) acrylic acid copolymer. It is characterized by
(4) The thermoplastic resin is composed of 50% by weight to 99% by weight of a styrene resin and 1% by weight to 50% by weight of a vinyl alcohol resin when the total amount of the thermoplastic resin is 100% by weight. To
(5) The vinyl alcohol resin is an ethylene-vinyl alcohol copolymer,
(6) The ethylene-vinyl alcohol copolymer consists of ethylene 20 mol% or more and 50 mol% or less and vinyl alcohol 50 mol% or more and 70 mol% or less,
(7) As a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule, at least one compound selected from the group consisting of water, methanol, and ethanol is used.
(8) The foaming agent is characterized by using at least one compound selected from the group consisting of hydrocarbons and halogenated hydrocarbons having an ozone depletion coefficient of 0.
(9) The styrene resin contains a styrene resin composition obtained by regenerating the thermoplastic resin foam described above.
It relates to the thermoplastic resin foam described above.

  A second aspect of the present invention is a method for producing a thermoplastic resin foam in which a thermoplastic resin comprising a styrene resin and a vinyl alcohol resin is heated and melted and extruded and foamed in a low pressure region. A thermoplastic resin composed of a resin, a compound having a molecular weight of 1,000 or less, a compound having one or more hydroxyl groups in the molecule, and a foaming agent having a ozone depletion coefficient of 0 and a group consisting of hydrocarbons and halogenated hydrocarbons The thermoplastic resin master comprising a styrene resin and a vinyl alcohol resin as a preferred embodiment of the method for producing a thermoplastic resin foam characterized by coexisting at least one selected compound and performing extrusion foaming A method for producing a thermoplastic resin foam in which a batch is heated and melted and extruded and foamed in a low pressure region, comprising a styrene resin and a vinyl resin. Hydrocarbons and halogenated hydrocarbons having a molecular weight of 1000 or less, a compound having one or more hydroxyl groups in the molecule, and a foaming agent having an ozone depletion coefficient of 0 in a thermoplastic resin masterbatch comprising an alcohol-based resin It relates to a method for producing a thermoplastic resin foam as described above, wherein extrusion foaming is performed in the presence of at least one compound selected from the group consisting of:

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic resin foam excellent in heat insulation performance retention property is provided. The thermoplastic resin foam of the present invention is particularly useful for use as a building heat insulating material from the viewpoint of its excellent heat insulating performance retention.

  The styrenic resin used in the present invention is not particularly limited, and can be obtained from, for example, a styrene homopolymer obtained only from a styrene monomer, a styrene monomer, a monomer copolymerizable with styrene, or a derivative thereof. Specific examples include random, block or graft copolymers, post-brominated polystyrene, modified polystyrene such as rubber-reinforced polystyrene, and the like. These may be used alone or in combination of two or more.

  Examples of the monomer copolymerizable with styrene include styrene such as methylstyrene, dimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, bromostyrene, dibromostyrene, tribromostyrene, chlorostyrene, dichlorostyrene, and trichlorostyrene. Derivatives, polyfunctional vinyl compounds such as divinylbenzene, (meth) acrylic compounds such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, acrylonitrile, and diene compounds such as budadiene Or its derivative | guide_body, unsaturated carboxylic acid anhydrides, such as maleic anhydride and itaconic anhydride, etc. are mention | raise | lifted. These may be used alone or in combination of two or more.

  In the present invention, as the styrene resin, it is preferable that a part or all of the styrene resin is composed of a polar styrene resin. Furthermore, when the total amount of the styrene resin is 100% by weight, the polystyrene is 0% by weight or more. Use of a styrene resin comprising 99% by weight or less and a styrene-polar monomer copolymer of 1% by weight or more and 100% by weight or less improves the dispersibility of the vinyl alcohol resin and improves the production stability of the foam. It is preferable because it can be improved.

  The polystyrene used in the present invention is not particularly limited as long as it is a polystyrene obtained from a styrene monomer.

  The polar monomer in the styrene-polar monomer copolymer of the present invention is a vinyl monomer containing in the molecule a polar group such as a carboxyl group, a hydroxyl group, or a nitrile group. Acids, maleic acids, unsaturated carboxylic acids such as itaconic acid and metal salts thereof, unsaturated carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride, nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile, vinyl Examples include unsaturated alcohols such as alcohol, allyl alcohol, and methallyl alcohol. Among these, (meth) acrylic acid such as methacrylic acid and acrylic acid is particularly preferably used since a copolymer with styrene is easily available and contributes greatly to improving the dispersibility of the vinyl alcohol resin. Therefore, the styrene resin having polarity is preferably a styrene- (meth) acrylic acid copolymer. Furthermore, when the total amount of the styrene resin is 100 wt%, the polystyrene is 0 wt%. It is preferably composed of 99% by weight or less and styrene- (meth) acrylic acid copolymer 1% by weight or more and 100% by weight or less.

  In the present invention, a vinyl alcohol resin is used. Specific examples of the vinyl alcohol resin include polyvinyl alcohol obtained only from vinyl alcohol, or a copolymer of vinyl alcohol and α-olefin. However, in order to maintain high gas barrier properties, the α-olefin copolymerization ratio is preferably 50 mol% or less.

  In the present invention, since it is easy to handle and the dispersion in the styrene resin can be improved to some extent by using the styrene-polar monomer copolymer as described above, the ethylene-vinyl alcohol copolymer is used as the vinyl alcohol resin. Is preferably used. Further, it is preferable that the ethylene-vinyl alcohol copolymer is composed of 20 mol% or more and 50 mol% or less of ethylene and 50 mol% or more and 70 mol% or less of vinyl alcohol.

  The blending ratio of the styrene resin and the vinyl alcohol resin in the present invention is 50% by weight to 99% by weight of the styrene resin and 1% by weight to 50% of the vinyl alcohol resin when the total amount of the thermoplastic resin is 100% by weight. It is preferable to set the weight% or less. If the amount of the vinyl alcohol resin is less than 1% by weight, the effect of improving the gas barrier property, that is, the heat insulation performance retention is small. If the amount of the vinyl alcohol resin is more than 50% by weight, the mechanical properties are lowered and the moldability is deteriorated. May cause problems.

  In the present invention, a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule is added. By adding a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule, the closed cell ratio is improved and the expansion ratio is improved, that is, the foam density is reduced. An excellent foam can be obtained.

  In the present invention, the compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule (hereinafter also referred to as “hydroxyl group-containing compound”) specifically includes methanol, ethanol, propyl alcohol, i-propyl. Monoalcohols such as alcohol, butyl alcohol, i-butyl alcohol, t-butyl alcohol, trimethylolpropane, tripentaerythritol, dipentaerythritol, pentaerythritol, trimethylolpropane ethoxylate, ethylene glycol, diethylene glycol, propylene glycol, butylene Glycol, glycerin, sorbitol, xylitol, xylose, erythritol, mannitol, arabitol, ribose, glucose, galactose, maltose, fructose, sac Loin, lactose, cellulose, alpha, beta, .gamma.-cyclodextrin, polyhydric alcohols such as methyl cellulose, and water. In particular, at least one compound selected from the group consisting of water, methanol, and ethanol is preferably used because it has a high effect of improving the closed cell ratio and the expansion ratio.

  The addition amount of the hydroxyl group-containing compound is appropriately adjusted within a range that does not impair the effects of the present invention, according to the type and blending ratio of the styrene resin and the vinyl alcohol resin, preferably, with respect to 100 parts by weight of the thermoplastic resin, It is 0.1 to 10 parts by weight, and more preferably 0.2 to 5 parts by weight. If the amount is less than 0.1 parts by weight, the effect of improving the closed cell ratio and the expansion ratio is not observed. If the amount exceeds 10 parts by weight, problems such as generation of pores may occur.

The blowing agent used in the present invention is appropriately adjusted within a range not impairing the effects of the present invention. From the viewpoint of environmental compatibility, the foaming agent is selected from the group consisting of hydrocarbons and halogenated hydrocarbons having an ozone depletion coefficient of 0. It is preferable to use one or more selected compounds (hereinafter, also referred to as “a compound having an ozone depletion coefficient of 0”). The ozone depletion coefficient means a relative value when the ozone depletion amount per unit weight of trichloromonofluoromethane (CFC-11: CCl ₃ F) is 1, and the ozone depletion coefficient is 0 Even if there is no ozone destructive action or ozone destructive action, it means that the ozone depletion coefficient is 0.01 or less.

  Among the compounds having an ozone depletion coefficient of 0 used in the present invention, examples of the hydrocarbon include saturated hydrocarbons having 3 to 5 carbon atoms, specifically, for example, propane, n-butane, i -Butane, n-pentane, i-pentane, c-pentane and the like. Among the saturated hydrocarbons having 3 to 5 carbon atoms, n-butane, i-butane, c-pentane or a mixture thereof is preferable from the viewpoint of the heat insulating performance of the foam, and i-butane is particularly preferable.

Among the compounds having an ozone depletion coefficient of 0 used in the present invention, examples of the halogenated hydrocarbon include hydrofluorocarbons having an ozone depletion coefficient of 0. Specifically, for example, trifluoromethane (HFC-23: CHF) ₃ ), difluoromethane (HFC-32: CH ₂ F ₂ ), 1,1,1,2,2-pentafluoroethane (HFC-125: CHF ₂ CF ₃ ), 1,1,1,2-tetrafluoro Ethane (HFC-134a: CH ₂ FCF ₃ ), 1,1,1-trifluoroethane (HFC-143a: CH ₃ CF ₃ ), 1,1-difluoroethane (HFC-152a: CH ₃ CHF ₂ ), 1, 1,1,2,3,3,3-heptafluoropropane _{(HFC-227ea: CF 3 CHFCF} 3), 1,1,1,3,3,3- hexafluoro Pro Emissions _{(HFC-236fa: CF 3 CH} 2 CF 3), 1,1,2,2,3- pentafluoropropane _{(HFC-245ca: CH 2 FCF} 2 CHF 2), 1,1,1,2,2- Pentafluoropropane (HFC-245cb: CF ₃ CF ₂ CH ₃ ), 1,1,1,3,3-pentafluoropropane (HFC-245fa: CF ₃ CH ₂ CHF ₂ ), 1,1,1,3 And 3-pentafluorobutane (HFC-365mfc: CF ₃ CH ₂ CF ₂ CH ₃ ). Among these, 1,1,1,2-tetrafluoroethane (HFC-134a: CH ₂ FCF ₃ ) is more preferable from the viewpoint of foam moldability.

  One or more compounds selected from the group consisting of hydrocarbons and halogenated hydrocarbons and having an ozone depletion coefficient of 0 may be used alone or in combination of two or more. Good.

  In the present invention, in addition to one or more compounds selected from the group of hydrocarbons and halogenated hydrocarbons having an ozone depletion coefficient of 0, other blowing agents (hereinafter also referred to as “other blowing agents”) are used in combination. It is also possible to do. By using another foaming agent, a plasticizing effect and a foaming aid effect at the time of manufacturing the thermoplastic resin foam can be obtained, the extrusion pressure can be reduced, and the thermoplastic resin foam can be stably manufactured. However, depending on various properties of the foam such as the target foaming ratio (foam density) and flame retardancy, the amount of use can be limited.

  Other blowing agents are not particularly limited, and for example, dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, n-butyl ether, diisopropyl ether, furan, furfural, 2-methyl furan, tetrahydrofuran, tetrahydropyran, etc. Ethers, dimethyl ketone, methyl ethyl ketone, diethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, methyl i-butyl ketone, methyl n-amyl ketone, methyl n-hexyl ketone, ethyl n-propyl ketone, ethyl n-butyl ketone, etc. Ketones, formic acid methyl ester, formic acid ethyl ester, formic acid propyl ester, formic acid butyl ester, formic acid amyl ester, propionic acid methyl ester, propionic acid ethyl ester It is possible to use carboxylic acid esters such as tellurium, organic foaming agents such as alkyl halides such as methyl chloride and ethyl chloride, inorganic foaming agents such as nitrogen and carbon dioxide, and chemical foaming agents such as azo compounds and tetrazole. it can. These other foaming agents may be used alone or in combination of two or more.

  Among other foaming agents, dimethyl ether, diethyl ether, methyl ethyl ether, methyl chloride, ethyl chloride, and the like are preferable from the viewpoint of foamability, foam moldability, and the like. Combustibility of foaming agent, flame retardancy of foam From this point, carbon dioxide is preferable. Among other blowing agents, dimethyl ether and carbon dioxide, which are excellent in environmental compatibility, are particularly preferable.

  In the present invention, if necessary, a foaming agent having an ozone depletion coefficient other than 0, such as chlorofluorocarbon and hydrochlorofluorocarbon, may be further used as the foaming agent, if necessary.

  In the production of the thermoplastic resin foam of the present invention, the amount of the foaming agent added or injected into the thermoplastic resin is appropriately changed according to the setting value of the expansion ratio (foam density), etc. Usually, when the total amount of the foaming agent is 100 parts by weight of the thermoplastic resin, it is preferably 1 part by weight or more and 20 parts by weight or less. When the addition amount of the foaming agent is less than 1 part by weight, the foaming ratio is low (the foam density is high), and the characteristics such as light weight and heat insulation as the thermoplastic resin foam may be difficult to be exhibited, while 20 weights. If it exceeds the part, due to the excessive amount of foaming agent, defects such as voids may occur in the thermoplastic resin foam, or the flame retardancy may be lowered depending on the type of foaming agent.

  In the foaming agent to be added, the mixing lower limit amount of the compound having an ozone depletion coefficient of 0 is preferably 10% by weight or more, more preferably 20% by weight or more with respect to 100% by weight of the total amount of the foaming agent. That is, the upper limit of mixing amount of other foaming agents is preferably 90% by weight or less, more preferably 80% by weight or less, with respect to 100% by weight of the total amount of foaming agent. When the amount of the compound having an ozone depletion coefficient of 0 is less than 10% by weight, the heat insulation of the obtained foam may be inferior. When the amount of the other foaming agent exceeds 90% by weight, for example, when obtaining an extruded foam, if the compatibility with the thermoplastic resin is high, the plasticity is too high, and the thermoplastic resin and the foaming agent in the extruder When the kneading state of the product becomes uneven and the pressure control of the extruder becomes difficult, or the compatibility with the resin is low, pores and the like are generated in the foam, and a good foam cannot be obtained, or the pressure of the extruder Control becomes difficult, and there is a tendency that the flame retardancy of the foam is lowered depending on the flammable foaming agent.

  In the foaming agent to be added, the mixing upper limit amount of the compound having an ozone depletion coefficient of 0 is based on 100% by weight of the total amount of the foaming agent from the viewpoint of obtaining a foam of good quality such as stable foam production and appearance. Thus, it is preferably 90% by weight or less, more preferably 80% by weight or less. That is, the mixing lower limit amount of the other foaming agent is preferably 10% by weight or more, more preferably 20% by weight or more with respect to 100% by weight of the total amount of the foaming agent.

  In the present invention, the pressure at the time of adding or injecting the foaming agent is not particularly limited, and may be a pressure higher than the internal pressure of the reaction kettle or the extruder.

  In the present invention, in order to obtain a high degree of heat insulation, the residual content of one or more compounds selected from the group consisting of hydrocarbons and halogenated hydrocarbons having an ozone depletion coefficient of 0 in the foam, In general, the amount is preferably 1 part by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin foam. In particular, in the case where higher heat insulation performance is required, such as three types of extruded polystyrene foam heat insulating plates, it is more preferable to use 2 or more parts by weight for one or more compounds that are hydrocarbons and have an ozone depletion potential of 0. 10 parts by weight or less, specifically, 2 parts by weight or more and 9 parts by weight or less are more preferable for propane, 3 parts by weight or more and 8 parts by weight or less are particularly preferable, and for n-butane or i-butane, 5 parts by weight or more and 9 parts by weight or less are more preferable, particularly preferably 2 parts by weight or more and 8 parts by weight or less, and n-pentane, i-pentane and c-pentane are preferably 2 parts by weight or more and 9 parts by weight or less, and halogenated. In the case of one or more compounds that are hydrocarbons and have an ozone depletion coefficient of 0, they are 2 parts by weight or more and 10 parts by weight or less, and specifically, high-level compounds such as 1,1,1,2-tetrafluoroethane. B 10 parts by weight or more than 2 parts by weight is preferred in fluorocarbon.

  Although it does not restrict | limit in particular in this invention, In order to use as a building material, it is preferable to add a halogenated flame retardant in a thermoplastic resin foam. The halogen flame retardant used is not particularly limited as long as it does not impair the effects of the present invention, and may be any compound having a halogen atom.

  Specific examples of the halogen-based flame retardant include (a) tetrabromoethane, tetrabromocyclooctane, hexabromocyclododecane, dibromoethyldibromocyclohexane, dibromodimethylhexane, 2- (bromomethyl) -2- (hydroxymethyl). ) -1,3-propanediol, dibromoneopentyl glycol, tribromoneopentyl alcohol, pentaerythrityl tetrabromide, monobromodipentaerythritol, dibromodipentaerythritol, tribromodipentaerythritol, tetrabromodipentaerythritol, pentabromo Brominated aliphatics such as dipentaerythritol, hexabromodipentaerythritol, hexabromotripentaerythritol, polybrominated polypentaerythritol, etc. Compound or derivative thereof, or brominated alicyclic compound or derivative thereof, (b) hexabromobenzene, pentabromotoluene, ethylenebispentabromodiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, bis (2,4,6- Brominated aromatic compounds such as (tribromophenoxy) ethane, tetrabromophthalic anhydride, octabromotrimethylphenylindane, pentabromobenzyl acrylate, tribromophenyl allyl ether, 2,3-dibromopropyl pentabromophenyl ether or derivatives thereof ( c) Tetrabromobisphenol A, tetrabromobisphenol A diallyl ether, tetrabromobisphenol A dimethallyl ether, tetrabromobisphenol A diglycidyl Ether, tetrabromobisphenol A diglycidyl ether tribromophenol adduct, tetrabromobisphenol A bis (2,3-dibromopropyl ether), tetrabromobisphenol A bis (2-bromoethyl ether), tetrabromobisphenol A bis ( 2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol S bis (2,3-dibromopropyl ether), tetrabromobisphenol S, and the like, and (d) tetrabromobisphenol A Brominated bisphenol derivatives oligomers such as polycarbonate oligomers, tetrabromobisphenol A diglycidyl ether and brominated bisphenol adduct epoxy oligomers, (e) brominated polymers Kuryl resin, (f) Bromine and nitrogen atom-containing compounds such as ethylenebisdibromonorbornanedicarboximide, tris (2,3-dibromopropyl) isocyanurate, (g) tris (tribromoneopentyl) phosphate, tris (bromophenyl) ) Bromine and phosphorus atom-containing compounds such as phosphate, (h) Chlorine-containing compounds such as chlorinated paraffin, chlorinated naphthalene, perchloropentadecane, chlorinated aromatic compounds, chlorinated alicyclic compounds, (i) bromide Examples thereof include brominated inorganic compounds such as ammonium. These compounds may be used alone or in combination of two or more. Furthermore, a brominated polystyrene resin that is one of the styrene resins of the present invention can also be used as a flame retardant.

  Of the above, halogenated aliphatic group-containing compounds are preferably used as the halogen-based flame retardant used in the present invention, in order to develop better flame retardancy. Specifically, for example, tetrabromoethane, tetrabromocyclooctane, hexabromocyclododecane, dibromoethyldibromocyclohexane, dibromodimethylhexane, 2- (bromomethyl) -2- (hydroxymethyl) -1,3-propanediol, Dibromoneopentyl glycol, tribromoneopentyl alcohol, pentaerythrityl tetrabromide, monobromodipentaerythritol, dibromodipentaerythritol, tribromodipentaerythritol, tetrabromodipentaerythritol, pentabromodipentaerythritol, hexabromodipentaerythritol , Hexabromotripentaerythritol, polybrominated polypentaerythritol, tetrabromobisphenol A bis (2,3-dibromide) Propyl ether), tetrabromobisphenol A bis (2-bromoethyl ether), tetrabromobisphenol A bis (2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol S bis (2,3-dibromopropyl ether) , Tris (2,3-dibromopropyl) isocyanurate, tris (tribromoneopentyl) phosphate, and the like.

  In order to achieve both good flame retardancy and heat resistance and recyclability, among the halogen-based flame retardants, measurement is performed particularly under a nitrogen stream of 50 ml / min and a temperature rising rate of 10 ° C./min. A halogenated aliphatic group-containing compound having a 5% thermal weight loss temperature of 250 ° C. or higher is more preferably used. Specific examples of the halogenated aliphatic group-containing compound having a 5% thermal weight loss temperature of 250 ° C. or more include tetrabromobisphenol A bis (2,3-dibromopropyl ether), tetrabromobisphenol A bis (2-bromo Ethyl ether), tetrabromobisphenol A bis (2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol S bis (2,3-dibromopropyl ether), tris (2,3-dibromopropyl) isocyanurate, And tris (tribromoneopentyl) phosphate.

  Of these, tetrabromobisphenol A bis (2,3-dibromopropyl ether) and / or tris (2,3-dibromopropyl) isocyanurate are most preferably used because they are easily available.

  The content of the halogen-based flame retardant used in the present invention is not particularly limited as long as it does not impair the effects of the present invention, but a foaming agent is provided so that the flame retardancy specified in JIS A9511 can be obtained. It is preferable to adjust appropriately according to the addition amount, the foam density, the type or addition amount of other additives, and the amount is generally 0.1 to 20 parts by weight with respect to 100 parts by weight of the thermoplastic resin. Preferably, it is 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight. When the content of the halogen-based flame retardant is less than 0.1 parts by weight or more than 20 parts by weight, good properties as a foam such as flame retardancy tend to be difficult to obtain.

  In the present invention, Al, Ti, V, Cr, Mn, Fe, Co are used as flame retardant aids for halogenated flame retardants for the purpose of obtaining a more excellent flame retardant effect within a range not impairing the effects of the present invention. , Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce, at least one metal compound selected from the group consisting of oxides, halides and phosphates (hereinafter referred to as “ Also referred to as a “metal compound”).

  Al, Ti, V, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce that can be used in the present invention As at least one metal compound selected from the group consisting of oxides, halides, and phosphates, Al, Mn, Fe, At least one compound selected from the group consisting of oxides, halides and phosphates of Ni, Cu, Zr or Mo is preferable, and is more preferable from the viewpoint of easy availability and particularly high flame retardant aid effect. It is.

  The content of the metal compound used in the present invention is not particularly limited as long as the effect of the present invention is not impaired, but flame retardancy and various physical properties defined in JISA 9511 are obtained. It is preferable to adjust appropriately according to the kind of metal compound to be used, the amount of foaming agent added, the density of the foam, the type of halogenated flame retardant and other additives or the amount added, etc., and generally 100 parts by weight of thermoplastic resin In contrast, 0.0001 to 1 part by weight is preferable, 0.0005 to 0.02 part by weight is more preferable, and 0.001 to 0.01 part by weight is further preferable. When the content of the metal compound is less than 0.0001 parts by weight, various properties such as flame retardancy tend to be difficult to obtain. On the other hand, when the content exceeds 1 part by weight, heat resistance, flame retardancy, and foam production In some cases, the moldability and surface properties of the resin may be impaired.

  In the present invention, the halogen-based flame retardant and the metal compound are further selected from the group consisting of a phosphorus-containing compound other than the metal phosphate, a nitrogen-containing compound, a boron-containing compound, and a sulfur-containing compound, as long as the effects of the present invention are not impaired. One or more compounds can be used in combination.

  In combination with one or more compounds selected from the group consisting of phosphorus-containing compounds other than metal phosphates, nitrogen-containing compounds, boron-containing compounds and sulfur-containing compounds, in particular, propane, n-butane, i-butane, c-pentane Even when a compound having a flammable ozone depletion coefficient of 0, such as a saturated hydrocarbon having 3 to 5 carbon atoms, is used as a foaming agent to exhibit high heat insulation performance, a halogen flame retardant and a metal compound High flame retardancy as defined in JISA 9511 can be achieved without adding a large amount of.

  The phosphorus-containing compound other than the metal phosphate used in the present invention is a compound containing a phosphorus atom and is not particularly limited as long as it is a compound that does not inhibit the effects of the halogen-based flame retardant and the metal compound. For example, phosphate, phosphonate, phosphinate, phosphite, phosphoric acid, phosphonic acid, phosphinic acid or derivatives thereof, melamine salt, ammonium salt, and phosphazene or derivatives thereof, phosphonitrile or derivatives thereof, Aliphatic hydrocarbon monophosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl acid phosphate, 2-methacryloyloxyethyl acid phosphate Ester, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate Tris (phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2 -Aromatic hydrocarbon monophosphates such as methacryloyloxyethyl phosphate, resorcinol / diphenyl phosphate, resorcinol / dixylenyl phosphate, resorcinol / dicresyl phosphate, bisphenol A / diphenyl phosphate, bisphenol A / dixylenyl phosphate, bisphenol A / Dicresyl phosphate, hydroquinone diphenyl phosphate, Idroquinone dixyrenyl phosphate, hydroquinone dicresyl phosphate, resorcinol polyphenyl phosphate, resorcinol poly (di-2,6-xylyl) phosphate bisphenol A polycresyl phosphate, hydroquinone poly (2,6-xylyl) phosphate Condensed phosphate ester, melamine phosphate, melamine phosphite, melamine pyrophosphate, ammonium phosphate, ammonium pyrophosphate, ammonium phosphate amide, phosphate amide, piperazine diphosphite, piperazine phosphite, pyrophosphate Piperazine, guanazole phosphite, phosphazene, melamine polyphosphate, melane polyphosphate, melem polyphosphate, ammonium polyphosphate, ammonium polyphosphate amide, polyphosphate amide, polyphosphate Examples thereof include phosphorus-containing nitrogen-containing compounds such as phosphazene and phosphonitrile. Furthermore, brominated phosphate compounds such as the aforementioned tris (tribromoneopentyl) phosphate and tris (bromophenyl) phosphate may be used as the phosphorus-containing compound other than the metal phosphate. Phosphorus-containing compounds other than metal phosphates may be used alone or in admixture of two or more.

  The addition amount of the phosphorus-containing compound other than the metal phosphate in the present invention is not particularly limited as long as it does not impair the effects of the present invention, so that the flame retardancy specified in JISA 9511 can be obtained. It is preferable to adjust appropriately depending on the type and content of the halogen-based flame retardant, the metal compound, and the foaming agent, the density of the obtained foam, and the like, and generally 0.1 weight with respect to 100 weight parts of the thermoplastic resin. Part to 10 parts by weight, preferably 0.3 parts to 9 parts by weight, and more preferably 0.5 parts to 8 parts by weight. If the amount of the phosphorus-containing compound other than the metal phosphate is less than 0.1 parts by weight, the synergistic effect of flame retardancy may not be obtained. If the amount exceeds 10 parts by weight, the moldability during foam production, etc. May be damaged.

  The nitrogen-containing compound used in the present invention is not particularly limited as long as it is a compound containing a nitrogen atom and does not inhibit the effects of the halogen-based flame retardant and the metal compound. Examples include triazine skeleton-containing compounds, cyanuric acid or isocyanuric acid and derivatives thereof, guanidine compounds, azo compounds, tetrazole compounds, etc., specifically, triazine skeleton-containing compounds such as melamine, melam, melem, melon, methylol melamine Or its derivatives, cyanuric acid, methyl cyanurate, diethyl cyanurate, trimethyl cyanurate, triethyl cyanurate, isocyanuric acid, methyl isocyanurate, N, N'-diethyl isocyanurate, trismethyl isocyanurate, trisethyl isocyanurate, bis Cyanu such as (2-carboxyethyl) isocyanurate, 1,3,5-tris (2-carboxyethyl) isocyanurate, tris (2,3-epoxypropyl) isocyanurate Acid, isocyanuric acid or its derivatives, salts consisting of a triazine skeleton-containing compound and cyanuric acid or isocyanuric acid and derivatives thereof, such as melamine, for example melamine cyanurate, and the like. Furthermore, the aforementioned azo compounds such as hydrazodicarbonamide, azodicarbonamide, azoisobutyronitrile, tetrazoleamine salts such as tetrazole guanidine salt, tetrazole piperazine salt, tetrazole ammonium salt, tetrazole sodium salt, tetrazole manganese salt Tetrazole compounds such as tetrazole metal salts such as 5,5-bistetrazole diguanidine salt, 5,5-bistetrazole diammonium salt, 5,5-bistetrazole diaminoguanidine salt, 5,5-bistetrazole piperazine salt For example, a blowing agent used as a blowing agent other than saturated hydrocarbons may be used as the nitrogen-containing compound. Furthermore, the above-mentioned ethylenebistetrabromophthalimide, ethylenebisdibromonorbornanedicarboximide, 2,4,6-tris (2,4,6-tribromophenoxy) -1,3,5-triazine, tris (2 Bromine and nitrogen atom-containing compounds such as (, 3-dibromopropyl) isocyanurate may be used as nitrogen-containing compounds. A nitrogen-containing compound may be used independently and may be used in mixture of 2 or more types.

  The addition amount of the nitrogen-containing compound in the present invention is not particularly limited as long as it does not impair the effects of the present invention, but a halogen flame retardant, so as to obtain the flame retardancy specified in JISA 9511, It is preferable to adjust appropriately depending on the type and content of the metal compound and the foaming agent, the density of the obtained foam, and the like, and generally 0.1 parts by weight or more and 10 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The following is preferable, 0.3 to 9 parts by weight is more preferable, and 0.5 to 8 parts by weight is further preferable. If the addition amount of the nitrogen-containing compound is less than 0.1 parts by weight, the synergistic effect of flame retardancy may not be obtained, and if it exceeds 10 parts by weight, the moldability during foam production may be impaired. .

  The boron-containing compound used in the present invention is not particularly limited as long as it is a compound containing a boron atom and does not inhibit the effects of the halogen-based flame retardant and the metal compound. For example, boric acid, borax, metal borate, boron oxide, boron phosphate, borosilicates, etc., specifically, boric acid, borax, zinc borate, barium borate, magnesium borate, boron Borate metal salts such as calcium oxide, aluminum borate, strontium borate, zirconium borate, tin borate, and hydrates of these compounds, diboron dioxide, diboron trioxide, tetraboron trioxide, Examples thereof include boron oxide such as tetraboron pentoxide. Boron-containing compounds can be used alone or in admixture of two or more.

  The addition amount of the boron-containing compound in the present invention is not particularly limited as long as it does not impair the effects of the present invention, but a halogen-based flame retardant, so that the flame retardancy specified in JISA 9511 can be obtained, It is preferable to adjust appropriately depending on the type and content of the metal compound and the foaming agent, the density of the obtained foam, and the like, and generally 0.1 parts by weight or more and 10 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The following is preferable, 0.3 parts by weight or more and 9 parts by weight or less are more preferable, and 0.5 parts by weight or more and 8 parts by weight or less are more preferable. If the addition amount of the boron-containing compound is less than 0.1 parts by weight, the synergistic effect of flame retardancy may not be obtained, and if it exceeds 10 parts by weight, the moldability during foam production may be impaired. .

  The sulfur-containing compound used in the present invention is not particularly limited as long as it is a compound containing a sulfur atom and does not inhibit the effects of the halogen-based flame retardant and the metal compound. Specific examples thereof include sulfate compounds such as ammonium sulfate, melamine sulfate, sodium sulfate, magnesium sulfate, calcium sulfate, aluminum sulfate, and iron sulfate, and sulfamic acid compounds such as sulfamic acid, ammonium sulfamate, and guanidine sulfamate. Benzenesulfonic acid, benzenedisulfonic acid, p-vinylbenzenesulfonic acid, p-toluenesulfonic acid, o-toluenesulfonic acid, p-octylbenzenesulfonic acid, o-octylbenzenesulfonic acid, p-dodecylbenzenesulfonic acid, m -Dodecylbenzenesulfonic acid, alkylbenzenesulfonic acid such as o-dodecylbenzenesulfonic acid, fluorobenzenesulfonic acid, chlorobenzenesulfonic acid, bromobenzenesulfonic acid, iodobenzenesulfone Acid, phenolsulfonic acid, phenoldisulfonic acid, sulfanilic acid (aminobenzenesulfonic acid), naphthalenesulfonic acid, 2-naphthol-1-sulfonic acid, 2-methylnaphthalene-1-sulfonic acid or lithium of these aromatic sulfonic acids Metal salts such as salts with Group 1A metals such as sodium, potassium, salts with Group 2A metals such as magnesium, calcium, barium, salts with metals such as zinc, iron, copper, etc. Examples thereof include sulfonic acid compounds. A sulfur-containing compound may be used independently and may mix and use 2 or more types.

  The addition amount of the sulfur-containing compound in the present invention is not particularly limited as long as the effect of the present invention is not impaired, but a halogen-based flame retardant, so as to obtain the flame retardancy specified in JISA 9511, It is preferable to adjust appropriately depending on the type and content of the metal compound and the foaming agent, the density of the obtained foam, and the like, and generally 0.1 parts by weight or more and 10 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The following is preferable, 0.3 to 9 parts by weight is more preferable, and 0.5 to 8 parts by weight is further preferable. If the addition amount of the sulfur-containing compound is less than 0.1 parts by weight, the synergistic effect of flame retardancy may not be obtained, and if it exceeds 10 parts by weight, the moldability during foam production may be impaired. .

  The phosphorus-containing compound, nitrogen-containing compound, boron-containing compound or sulfur-containing compound other than the metal phosphate in the present invention may be used alone or in combination of two or more.

  In the present invention, the phosphorus-containing compound, nitrogen-containing compound, boron-containing compound or sulfur-containing compound other than the metal phosphate is, for example, various thermosetting resins, various thermoplastic resins, silane coupling agents, titanium-based compounds, inorganic compounds. Those obtained by surface coating with a surface treatment agent such as one or more compounds selected from compounds and the like can also be suitably used.

  In the present invention, if necessary, various flame retardant aids, silica, talc, calcium silicate, wollastonite, kaolin, clay, mica, calcium carbonate, etc., as long as the effects of the present invention are not impaired. Compounds, processing aids such as sodium stearate, magnesium stearate, barium stearate, liquid paraffin, olefin wax, stearylamide compound, phenolic antioxidant, phosphorus stabilizer, nitrogen stabilizer, sulfur stabilizer Agents, light-resistant stabilizers such as benzotriazoles and hindered amines, flame retardants other than those mentioned above, antistatic agents, pigments, epoxy compounds, smectites, swellable fluorinated mica, and other water-absorbing or water-swelling layered silicates Organic processing product, water-absorbing polymer, AEROSIL manufactured by Nippon Aerosil Co., Ltd. Additives such as water absorbing material that can absorb water such as water anhydrous silica having any silanol groups can be contained.

  The flame retardant aid is not particularly limited as long as it does not impair the effects of the present invention, but a halogen flame retardant and a metal compound are used so that the flame retardancy specified in JIS A 9511 can be obtained. A substance that does not inhibit the effect is preferable, and a flame retardant aid such as diphenylalkane that decomposes by heat to generate radicals is preferable.

  In the present invention, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis is used for more stable extrusion foaming. {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-tert-butyl-4-hydroxy-benzyl phosphate-diethyl ester, 1,3,5-trimethyl- , 4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate Antioxidant, triphenyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bisstearyl pentaerythritol diphos Phyto, bis (2,4-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4,4 ′ -Phosphorus stabilizers such as diylbisphosphonite, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, Amine stabilizers such as killed diphenylamine, octylated diphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, 3,3-thiobispropionic acid didecyl ester, 3,3′-thiobispropion It is preferable to add an epoxy compound such as a sulfur stabilizer such as acid dioctadecyl ester, bisphenol A-diglycidyl ether or a derivative thereof.

  In the present invention, it is preferable to add a nucleating agent such as talc or carbonate in order to form bubbles in the foam more stably.

  Furthermore, in the present invention, in order to more stably perform extrusion foam molding, fatty acid metal salts such as sodium stearate, magnesium stearate, barium stearate, zinc stearate, liquid paraffin, olefin wax, stearylamide It is preferable to add a lubricant or processing aid such as a compound.

  The thermoplastic resin foam of the present invention comprises a styrene resin and a vinyl alcohol resin, and, if necessary, a halogenated aliphatic group-containing compound, a metal compound, a phosphorus-containing compound other than a metal phosphate, a nitrogen-containing compound, A compound having one or more hydroxyl groups in a molecule having a molecular weight of 1000 or less under a high-pressure condition at an arbitrary stage by supplying a boron compound, a sulfur-containing compound, or other additives to a heating and melting means such as an extruder And a foaming agent is added to the thermoplastic resin to form a fluidized gel, cooled to a temperature suitable for extrusion foaming, and extruded and foamed through a die into the low pressure region to form a foam.

As an addition procedure when heat-melting an additive such as a styrene-based resin and a vinyl alcohol-based resin, a halogen-based flame retardant, and a foaming agent, for example,
(Ii) Styrenic resins and vinyl alcohol resins, and if necessary, halogen-based flame retardants, metal compounds, phosphorus-containing compounds other than metal phosphates, nitrogen-containing compounds, boron-containing compounds, sulfur-containing compounds, or others After mixing the additives, heat melt
(B) Styrenic resin and vinyl alcohol resin, and if necessary, halogen flame retardant, metal compound, phosphorus-containing compound other than phosphoric acid metal salt, nitrogen-containing compound, boron-containing compound, sulfur-containing compound, or others After mixing one or more additives selected from these additives, the mixture is heated and melted, and the remaining additives are added to the mixture as it is or liquefied or melted as necessary, and heated and mixed.
(Ha) In advance to a styrene resin and a vinyl alcohol resin, if necessary, a halogen-containing flame retardant, a metal compound, a phosphorus-containing compound other than a metal phosphate, a nitrogen-containing compound, a boron-containing compound, a sulfur-containing compound, or After mixing one or more additives selected from other additives, prepare a heated and melted composition, and then mix the composition and the remaining additives, and if necessary, a thermoplastic resin. Supply to an extruder and melt by heating.
However, it is not limited to these.

  However, in order to improve the dispersibility of the vinyl alcohol resin in the styrene resin, it is preferable to melt and knead the styrene resin and the vinyl alcohol resin in advance as a master batch.

  In the present invention, the heating temperature, the melt-kneading time, and the melt-kneading means when heating and kneading the thermoplastic resin and additives such as a foaming agent are not particularly limited.

  The heating temperature may be equal to or higher than the temperature at which the styrene resin and vinyl alcohol resin to be used are melted, but the temperature at which molecular degradation of the resin due to the influence of a flame retardant is suppressed as much as possible, for example, 150 to 240 ° C. The degree is preferred.

  The melt-kneading time varies depending on the extrusion amount per unit time, the melt-kneading means, etc., and thus cannot be determined unconditionally, but the time required for uniformly dispersing and mixing the thermoplastic resin and the foaming agent is appropriately selected. .

  Examples of the melt-kneading means include a screw type extruder, but there is no particular limitation as long as it is used for ordinary extrusion foaming.

  Also, the foam molding method is not particularly limited. For example, the foam obtained by releasing the pressure from the slit die may be used, for example, a molding die and a molding roll installed in close contact with or in contact with the slit die. A general method for forming a plate-like foam can be used.

  The thickness of the foam of the present invention is not particularly limited and is appropriately selected depending on the application. For example, in the case of a heat insulating material used for a building material or the like, in order to give a preferable heat insulating property, bending strength and compressive strength, the thickness is not as thin as a sheet but as a normal plate. Is preferable, usually 10 to 150 mm, preferably 20 to 100 mm.

The density of the foam of the present invention, it is preferable that lightweight and excellent heat insulating properties and bending strength, in order to allowed to impart compressive strength is 15~50kg / m ^3, a 20~45kg / m ³ Is more preferable.

  A thermoplastic resin foam obtained by extrusion-foaming a thermoplastic resin comprising a styrene resin and a vinyl alcohol resin in the present invention in the presence of a hydroxyl group-containing compound excluding the vinyl alcohol resin is a foam. The resulting product can be regenerated and used again for molding. For example, a styrene resin composition obtained by pulverizing the thermoplastic resin foam of the present invention and regenerating by melting pellets with an extruder as a part of the styrene resin is a so-called new styrene resin that is not used for molding. And extrusion foaming is possible. The upper limit amount of the regenerated styrene resin composition is appropriately adjusted within a range not impairing the effects of the present invention. For example, 200 parts by weight, preferably 150 parts by weight with respect to 100 parts by weight of a new styrene resin. It can be illustrated.

  Next, although the thermoplastic resin extrusion foam of this invention is demonstrated in detail based on an Example, this invention is not restrict | limited only to this Example. Unless otherwise specified, “parts” represents parts by weight and “%” represents% by weight.

In the examples and comparative examples, the following raw materials were used.
A: Styrene resin A-1: Polystyrene (manufactured by PS Japan Co., Ltd., G9401)
A-2: Styrene-methacrylic acid copolymer (PS Japan Co., Ltd., G9001, containing 8% by weight of methacrylic acid)
B: Vinyl alcohol resin B-1: Ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., F101, containing 32 mol% ethylene)
B-2: Polyvinyl alcohol (manufactured by Kuraray Co., Ltd.)
C: Compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule C-1: water (Settsu City Water)
C-2: Ethanol (Wako Pure Chemical Industries, Ltd. reagent special grade)
C-3: Ethylene glycol (special grade reagent for Wako Pure Chemical Industries, Ltd.)
D: Halogen flame retardant D-1: Tetrabromobisphenol A-bis (2,3-dibromopropyl ether) (manufactured by Teijin Chemicals Ltd., Fireguard 3100, melting point: 90-105 ° C., 5% weight loss temperature: 300 ° C)
D-2: Tris (2,3-dibromopropyl) isocyanurate (B-2) (manufactured by Nippon Kasei Co., Ltd., TAIC-6B, melting point: 105 ° C., 5% weight loss temperature: 285 ° C.)
E: Metal compound E-1: Iron oxide (Fe ₂ O ₃ , reagent manufactured by Wako Pure Chemical Industries, Ltd.)
F: Phosphorus-containing compound other than metal phosphate, nitrogen-containing compound, boron-containing compound or sulfur-containing compound F-1: Triphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., TPP)
F-2: Isocyanuric acid (manufactured by Shikoku Kasei Co., Ltd., ICA-P)
F-3: Boron oxide (reagent manufactured by Wako Pure Chemical Industries, Ltd.)
F-4: p-Toluenesulfonic acid monohydrate (Reagent manufactured by Wako Pure Chemical Industries, Ltd.)
G: foaming agent; one or more compounds selected from the group consisting of hydrocarbons and halogenated hydrocarbons and having an ozone depletion coefficient of 0 G-1: isobutane (isobutane, manufactured by Mitsui Chemicals, Inc.)
G-2: Cyclopentane (manufactured by Taiyo Liquefied Gas Co., Ltd., cyclopentane)
G-3: HFC-134a (manufactured by Daikin Industries, Ltd., HFC-134a)
H: Other blowing agent H-1: Dimethyl ether (Mitsui Chemicals, dimethyl ether)
I: Other additives I-1: Talc (manufactured by Hayashi Kasei Co., Ltd., Talcan powder)
I-2: Barium stearate (manufactured by Sakai Chemical Industry Co., Ltd., barium stearate)
J: Vinyl alcohol-based resin-containing styrene-based resin master batch J-1: Ethylene-vinyl alcohol copolymer (B-1) 20% by weight-containing styrene-methacrylic acid copolymer (A-2) master batch Obtained foam Evaluation and measurement methods for the body are as follows.
(1) Density of foam After the extruded foam is cut into a rectangular parallelepiped of about 200 mm x 100 mm x 25 mm, this weight is measured, and the vertical, horizontal, and height dimensions are measured with a caliper, and the foam density is calculated by the formula : Foam density (g / cm ³ ) = foam weight (g) / foam volume (cm ³ )
And the unit was expressed in terms of (kg / m ³ ).
(2) Closed Cell Ratio After the extruded foam was cut into a rectangular parallelepiped of about 10 mm × 10 mm × 10 mm, it was measured using a multi-pynometer (manufactured by Yuasa Ionics) based on ASTM D-2856.
(3) Thermal conductivity The thermal conductivity of the extruded foam was measured according to JISA 9511. For measurement, HC-074 manufactured by Eihiro Seiki Co., Ltd. was used, and three rectangular parallelepiped test pieces of about 300 mm × 100 mm × 25 mm were cut out from the extruded foam, and these were arranged side by side and set in HC-074 as a shape of 300 mm × 300 mm × 25 mm. . The measurement was performed on foams that had passed 1 day and 100 days after the 10 mm portion was removed from the surface after production.
(4) Combustibility The combustibility of the extruded foam was evaluated according to the following criteria using test pieces having a thickness of 10 mm, a length of 200 mm and a width of 25 mm in accordance with JISA 9511. The measurement was carried out on foams that had passed 7 days after being cut into the above dimensions after production.
(A) Combustion time ◎: All five flame extinguishing times are within 3 seconds. ○: Out of 5 flame extinguishing times, at least one exceeds 3 seconds, but the remaining 3 or more are within 3 seconds. : At least 3 out of 5 flame extinguishing times exceed 3 seconds, but one or more remaining flames are within 3 sec. X: All 5 flame extinguishing times exceed 3 sec. (B) Burning distance ◎: 5 ○ Stops within the limit line in all of the circles: At least one out of the five exceeds the limit line, but the remaining three or more stop combustion within the limit line. Δ: At least out of the five lines Combustion exceeds the limit line for three, but combustion stops within the limit line for the remaining one or more. X: Combustion exceeds the limit line for all five (Reference Example 1) Ethylene-vinyl alcohol copolymer ( B-1) 20 wt% styrene-methacrylic acid copolymer (A-2) masterbatch Production of J-1) A blend comprising 80 parts of a styrene-methacrylic acid copolymer (A-2) and 20 parts of an ethylene-vinyl alcohol copolymer (B-1) was dry blended, and the resulting mixture was calibrated to a diameter of 30 mm. Were fed at a rate of 15 kg / hr. The mixture was heated and kneaded at 220 ° C. using the same extruder, and the strand was drawn from a 12-hole die provided at the tip, and after water cooling, pelletized using a strand cutter to obtain a master batch (J-1). .
Example 1
80 parts of styrene-methacrylic acid copolymer (A-2), 20 parts of ethylene-vinyl alcohol copolymer (B-1), 0.5 part of talc (I-1), barium stearate (I-2) 0 A mixture consisting of 25 parts was dry blended, and the resulting mixture was fed at a rate of about 70 kg / hr to an extruder in which those having a diameter of 65 mm and a diameter of 90 mm were vertically connected. The mixture supplied to the 65 mm diameter extruder is kneaded by heating to 220 ° C., and the resin temperature is cooled to 130 ° C. with an extruder having a 90 mm diameter connected to the extruder. Extruded into the atmosphere from the provided base having a rectangular cross section with a thickness direction of 2 mm and a width direction of 50 mm, a rectangular parallelepiped extruded foam was obtained. The density of the obtained foam was 31 kg / m ³ .

At this time, 1 part of water (C-1) as a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule, 4 parts of isobutane (G-1) and dimethyl ether (H-1) as a blowing agent Two parts were press-fitted into the resin from the vicinity of the tip of the 65 mm diameter extruder (the end connected to the end opposite to the die of the 90 mm diameter extruder). The properties of the obtained extruded foam are shown in Table 1.
(Examples 2 to 6)
Polystyrene (A-1), styrene-methacrylic acid copolymer (A-2), ethylene-vinyl alcohol copolymer (B-1), polyvinyl alcohol (B-2), ethylene-vinyl alcohol copolymer 20 weight A foam was obtained in the same manner as in Example 1 except that the addition amount of the% -containing styrene-methacrylic acid copolymer master batch (J-1) was changed to the value shown in Table 1. The properties of the obtained extruded foam are shown in Table 1.
(Comparative Examples 1-2)
The addition amounts of polystyrene (A-1), styrene-methacrylic acid copolymer (A-2), ethylene-vinyl alcohol copolymer (B-1), and water (C-1) were set to the values shown in Table 1. Except for the above, a foam was obtained in the same manner as in Example 1.

本発明の実施例である実施例１〜６と比較例１〜２を比較して明らかなように、本発明によれば、スチレン系樹脂とビニルアルコール系樹脂からなる熱可塑性樹脂を、分子量が１０００以下の、分子中に１つ以上の水酸基を有する化合物存在下、押出発泡することにより、断熱性能保持性に優れた熱可塑性樹脂発泡体が得られることが判る。
（実施例７）
スチレン−メタクリル酸共重合体（Ａ−２）８０部、エチレン−ビニルアルコール共重合体（Ｂ−１）２０部、タルク（Ｉ−１）０．５部、ステアリン酸バリウム（Ｉ−２）０．２５部からなる混合物をドライブレンドし、得られた混合物を口径６５ｍｍと口径９０ｍｍのものを縦に連結した押出機へ約７０ｋｇ／ｈｒの割合で供給した。前記口径６５ｍｍの押出機に供給した混合物を、２２０℃に加熱して混練し、これに連結された口径９０ｍｍの押出機で樹脂温度を１３０℃に冷却して、口径９０mmの押出機の先端に設けた厚さ方向２ｍｍ、幅方向５０ｍｍの長方形断面の口金より大気中へ押し出し、直方体状の押出発泡体を得た。得られた発泡体の密度は３３ｋｇ／ｍ³であった。

As is clear by comparing Examples 1 to 6 and Comparative Examples 1 and 2 which are examples of the present invention, according to the present invention, a thermoplastic resin composed of a styrene resin and a vinyl alcohol resin has a molecular weight of It can be seen that a thermoplastic resin foam excellent in heat insulation performance retention can be obtained by extrusion foaming in the presence of a compound having one or more hydroxyl groups in the molecule of 1000 or less.
(Example 7)
80 parts of styrene-methacrylic acid copolymer (A-2), 20 parts of ethylene-vinyl alcohol copolymer (B-1), 0.5 part of talc (I-1), barium stearate (I-2) 0 A mixture consisting of 25 parts was dry blended, and the resulting mixture was fed at a rate of about 70 kg / hr to an extruder in which those having a diameter of 65 mm and a diameter of 90 mm were vertically connected. The mixture supplied to the 65 mm diameter extruder is kneaded by heating to 220 ° C., and the resin temperature is cooled to 130 ° C. with an extruder having a 90 mm diameter connected to the extruder. Extruded into the atmosphere from the provided base having a rectangular cross section with a thickness direction of 2 mm and a width direction of 50 mm, a rectangular parallelepiped extruded foam was obtained. The density of the obtained foam was 33 kg / m ³ .

At this time, 1 part of water (C-1) as a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule, 3 parts of isobutane (G-1) and HFC-134a (G- 3) 3 parts were press-fitted into the resin from the vicinity of the tip of the 65 mm diameter extruder (the end connected to the end opposite to the die of the 90 mm diameter extruder).
The properties of the obtained extruded foam are shown in Table 2.
(Examples 8 to 17)
Compound (C) having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule, halogen-based flame retardant (D), metal compound (E), phosphorus-containing compound, nitrogen-containing compound, boron-containing compound, sulfur-containing compound A foam was obtained in the same manner as in Example 7 except that the types and addition amounts of (F), the foaming agent (G), and the other foaming agent (H) were changed to the values shown in Table 2.
The properties of the obtained extruded foam are shown in Table 2.
(Comparative Examples 3-4)
Polystyrene (A-1), styrene-methacrylic acid copolymer (A-2), ethylene-vinyl alcohol copolymer (B-1), a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule The types and addition amounts of (C), metal compounds (E), phosphorus-containing compounds, nitrogen-containing compounds, boron-containing compounds, sulfur-containing compounds (F), blowing agents (G), and other blowing agents (H) are shown. A foam was obtained in the same manner as in Example 7 except that the value shown in 2 was used. The properties of the obtained extruded foam are shown in Table 2.

本発明の実施例である実施例７〜１７と比較例３〜４を比較して明らかなように、本発明によれば、スチレン系樹脂とビニルアルコール系樹脂からなる熱可塑性樹脂を、分子量が１０００以下の、分子中に１つ以上の水酸基を有する化合物存在下、押出発泡することにより、断熱性能保持性に優れた熱可塑性樹脂発泡体が得られると共に、さらに、特定の難燃剤および、難燃助剤を使用することにより、難燃性にも優れた発泡体が得られることが判る。

As is clear from comparison of Examples 7 to 17 and Comparative Examples 3 to 4 which are examples of the present invention, according to the present invention, a thermoplastic resin composed of a styrene resin and a vinyl alcohol resin has a molecular weight of Extrusion foaming in the presence of a compound having one or more hydroxyl groups in the molecule of 1000 or less provides a thermoplastic resin foam excellent in heat insulation performance retention, and further, a specific flame retardant and difficulty. It turns out that the foam excellent also in the flame retardance is obtained by using a fuel adjuvant.

Claims (12)

  A thermoplastic resin foam obtained by extrusion foaming a thermoplastic resin comprising a styrene resin and a vinyl alcohol resin in the presence of a compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule. .   The thermoplastic resin foam according to claim 1, wherein a part or all of the styrene resin is made of a styrene resin having polarity.   The thermoplastic resin foam according to claim 2, wherein the polar styrene resin is a styrene- (meth) acrylic acid copolymer.   The styrene resin is composed of 0 wt% or more and 99 wt% or less of polystyrene and 1 wt% or more and 100 wt% or less of styrene- (meth) acrylic acid copolymer when the total amount of styrene resin is 100 wt%. The thermoplastic resin foam according to any one of claims 1 to 3.   The thermoplastic resin is composed of 50% by weight or more and 99% by weight or less of a styrene resin and 1% by weight or more and 50% by weight or less of a vinyl alcohol resin when the total amount of the thermoplastic resin is 100% by weight. The thermoplastic resin foam as described in any one of 1-4.   The thermoplastic resin foam according to any one of claims 1 to 5, wherein the vinyl alcohol resin is an ethylene-vinyl alcohol copolymer.   The thermoplastic resin foam according to claim 6, wherein the ethylene-vinyl alcohol copolymer comprises 20 mol% or more and 50 mol% or less of ethylene and 50 mol% or more and 70 mol% or less of vinyl alcohol.   8. The compound according to claim 1, wherein at least one compound selected from the group consisting of water, methanol, and ethanol is used as the compound having a molecular weight of 1,000 or less and having one or more hydroxyl groups in the molecule. The thermoplastic resin foam according to Item.   The heat according to any one of claims 1 to 8, wherein at least one compound selected from the group consisting of hydrocarbons and halogenated hydrocarbons having an ozone depletion coefficient of 0 is used as the foaming agent. Plastic resin foam.   The styrenic resin contains a styrenic resin composition obtained by regenerating the thermoplastic resin foam according to any one of claims 1 to 9. Thermoplastic resin foam.   A method for producing a thermoplastic resin foam in which a thermoplastic resin composed of a styrene resin and a vinyl alcohol resin is heated and melted and extruded and foamed in a low pressure region, the thermoplastic resin comprising a styrene resin and a vinyl alcohol resin A compound having a molecular weight of 1000 or less and having one or more hydroxyl groups in the molecule, and at least one compound selected from the group consisting of hydrocarbons and halogenated hydrocarbons having an ozone depletion coefficient of 0 as a foaming agent A method for producing a thermoplastic resin foam, characterized in that extrusion foaming is carried out in the presence of.   A method for producing a thermoplastic resin foam in which a thermoplastic resin masterbatch comprising a styrene resin and a vinyl alcohol resin is heated and melted and extruded and foamed in a low pressure region, the thermoplastic comprising a styrene resin and a vinyl alcohol resin The resin master batch has a molecular weight of 1000 or less, a compound having one or more hydroxyl groups in the molecule, and at least selected from the group consisting of hydrocarbons and halogenated hydrocarbons having an ozone destruction coefficient of 0 as a foaming agent The method for producing a thermoplastic resin foam according to claim 11, wherein extrusion foaming is performed in the presence of one compound.