JP2006056998A - Styrene-based resin foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a styrene-based resin foam excellent in flame retardance and excellent also in heat resistance and a recycling property. <P>SOLUTION: The styrene-based resin foam comprises a halogen-based flame retardant. The styrene-based resin foam excellent in flame retardance is obtained by using a halogen-based flame retardant in which weight reduction starting temperature of the halogen-based flame retardant in the styrene-based foam by heating [measured at a raising rate of 10°C/min under nitrogen stream (50 mL/min)] is ≤300°C. The styrene-based resin foam excellent also in heat resistance and the recycling property is obtained by using a halogen-based flame retardant in which weight reduction starting temperature of the halogen-based flame retardant by heating is 260-280°C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a styrene resin foam excellent in flame retardancy.

  Styrenic resin foams are widely used for cushioning materials, fish boxes, food trays, heat insulating building materials, and the like. Of these, flame resistance is sometimes required because it is necessary to ensure safety against fires, especially when used for heat insulating building materials. Organic halogen compounds, especially bromine such as hexabromocyclododecane, etc. Series flame retardants are widely used. However, when such a flame retardant is used, if the amount of a certain type of flame retardant added is too large, deterioration of physical properties such as heat resistance and mechanical properties of the foam may be seen. When restrained, problems such as inability to obtain sufficient flame retardancy were sometimes observed. Such problems may also occur due to changes in the type and amount of the flame retardant, as well as other additives and production conditions, and the correlation between them is still unclear.

On the other hand, studies have been made on efficient flame retardant design by adapting the thermal decomposition behavior of various resins and flame retardants (for example, see Non-Patent Document 1). Although the above-mentioned problem in the polystyrene resin foam is also described as a problem due to the high and low decomposition start temperature of the flame retardant used, it is not limited to the specific decomposition start temperature. (See Patent Document 1). In addition, the thermal decomposition behavior of polystyrene and flame retardant alone does not necessarily match the thermal decomposition behavior of polystyrene and flame retardant in the blended composition and its foam. For example, in wood and the like, studies have been made to obtain a correlation between a difference in thermogravimetric reduction between an untreated product and a flame retardant treated product and a difference in flame retardant behavior (see, for example, Non-Patent Document 2). However, in polystyrene resin foams, the relationship between the thermal weight reduction behavior and various physical properties such as flame retardancy has not been clarified.
JP 2003-292664 A Hitoshi Nishizawa: Flame-retardant polymer, Taiseisha, p. 55 (1988) Hitoshi Nishizawa: Polymer Flame Retardant Technology, CMC Publishing, 67-74 (2002)

  Under such circumstances, a problem to be solved by the present invention is to provide a styrene resin foam excellent in flame retardancy.

  As a result of diligent research to solve the above problems, the present inventors have determined that, in a styrene resin foam containing a halogen flame retardant, the thermal weight reduction start temperature of the halogen flame retardant in the styrene resin foam. It was found that a styrene resin foam excellent in flame retardancy can be obtained by adjusting the temperature (measured at a rate of temperature increase of 10 ° C./min under a nitrogen stream (50 ml / min)) to 300 ° C. or less. It came to. In addition, by setting the thermogravimetric decrease starting temperature to 260 to 280 ° C., a foam having excellent flame resistance, heat resistance and recyclability can be obtained, and the ozone depletion coefficient is 0 as a foaming agent. It was found that a foam having excellent environmental compatibility can be obtained by using this compound.

That is, the present invention relates to the following (1) to (12).
(1) A styrene-based resin foam containing a halogen-based flame retardant, wherein the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene-based resin foam (in a nitrogen stream (50 ml / min), temperature increase rate) A styrenic resin foam characterized by having a measurement at 10 ° C./min) of 300 ° C. or less.
(2) The styrene resin foam according to (1), wherein the styrene resin foam is extruded and foamed.
(3) The thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam is 260 to 280 ° C. The styrene resin foam as described in (1) or (2).
(4) The styrene resin foam according to any one of (1) to (3), wherein the halogen flame retardant is a halogenated aliphatic group-containing compound.
(5) The halogenated aliphatic group-containing compound has a 5% thermal weight loss temperature (measured at a temperature rising rate of 10 ° C./min under a nitrogen stream (50 ml / min)) of 250 ° C. or more. The styrenic resin foam according to (4).
(6) The halogenated aliphatic group-containing compound is tris (2,3-dibromopropyl) isocyanurate and / or tetrabromobisphenol A bis (2,3-dibromopropyl ether) (4 Or a styrenic resin foam according to (5).
(7) The foaming agent is at least one compound selected from the group consisting of hydrocarbons and halogenated hydrocarbons and having an ozone depletion coefficient of 0. (1) to (6) The styrenic resin foam according to any one of the preceding claims.
(8) The thermal weight reduction start temperature of the halogenated flame retardant in the styrene resin foam, the thermal weight reduction start temperature of the halogenated flame retardant alone (the halogenated flame retardant alone in a nitrogen stream (50 ml / min) ), Measured at a heating rate of 10 ° C./min), the styrenic resin foam according to any one of (1) to (7), wherein the range of decrease is 5 ° C. or more.
(9) Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxide, halide and phosphoric acid The styrenic resin foam according to any one of (1) to (8), comprising at least one metal compound selected from the group consisting of salts.
(10) The styrene resin foam according to (9), wherein the metal compound is iron oxide.
(11) The cells forming the styrene resin foam are mainly composed of bubbles having a bubble diameter of 0.25 mm or less and bubbles having a bubble diameter of 0.3 to 1 mm. The styrenic resin foam according to any one of the preceding claims.
(12) The styrene resin contains a styrene resin composition obtained by regenerating the styrene resin foam according to any one of (1) to (11). (1) to (11) The styrenic resin foam according to any one of the above.

  According to the present invention, a styrene resin foam excellent in flame retardancy is provided.

  The styrenic resin foam of the present invention is useful for various uses, particularly for the use of heat insulating materials for buildings, from the viewpoint of excellent flame retardancy.

  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.

  Among the styrene resins, styrene homopolymer, styrene-acrylonitrile copolymer, (meth) acrylic acid copolymer polystyrene, maleic anhydride-modified polystyrene, impact-resistant polystyrene and the like are preferable from the viewpoint of processability.

  The halogen flame retardant used in the present invention is not particularly limited as long as it can conform to the effects of the present invention, and may be any compound having a halogen atom.

  Specifically, for example, (a) tetrabromoethane, tetrabromocyclooctane, hexabromocyclododecane, dibromoethyldibromocyclohexane, dibromodimethylhexane, 2- (bromomethyl) -2- (hydroxymethyl) -1,3- Propanediol, dibromoneopentyl glycol, tribromoneopentyl alcohol, pentaerythrityl tetrabromide, monobromodipentaerythritol, dibromodipentaerythritol, tribromodipentaerythritol, tetrabromodipentaerythritol, pentabromodipentaerythritol, hexabromo Brominated aliphatic compounds such as dipentaerythritol, hexabromotripentaerythritol, polybrominated polypentaerythritol, or derivatives thereof Or a brominated alicyclic compound or a derivative thereof, (b) hexabromobenzene, pentabromotoluene, ethylenebispentabromodiphenyl, decabromodiphenyl ether, octabromodiphenyl ether, bis (2,4,6-tribromophenoxy) ethane, Brominated aromatic compounds such as 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, tetrabromo Tribromophenol adduct of Sphenol A diglycidyl ether, 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 brominated bisphenols and derivatives thereof, (d) tetrabromobisphenol A polycarbonate oligomer, Brominated bisphenol derivatives oligomers such as tetrabromobisphenol A diglycidyl ether and brominated bisphenol adduct epoxy oligomer, (e) brominated acrylic resin, (f) ethyl Bromine and nitrogen atom-containing compounds such as bisdibromonorbornanedicarboximide, tris (2,3-dibromopropyl) isocyanurate, (g) bromine such as tris (tribromoneopentyl) phosphate, tris (bromophenyl) phosphate and Phosphorus atom-containing compounds, (h) chlorine-containing compounds such as chlorinated paraffin, chlorinated naphthalene, perchloropentadecane, chlorinated aromatic compounds, chlorinated alicyclic compounds, (i) brominated inorganic materials such as ammonium bromide Compounds, and the like. 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.

  As the halogen-based flame retardant used in the present invention, the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam described later easily satisfies 300 ° C. or less, and exhibits better flame retardancy. Among these, a halogenated aliphatic group-containing compound is particularly preferably used. 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 addition, the thermal weight reduction start temperature of the halogen-based flame retardant in a styrene-based resin foam, which will be described later, easily satisfies 260 to 280 ° C., in order to achieve both good flame retardancy and various physical properties such as heat resistance. Of the above, a halogenated aliphatic group-containing compound having a 5% thermal weight loss temperature (measured under a nitrogen stream (50 ml / min) at a heating rate of 10 ° C./min) of 250 ° C. or more is more preferable. Used. Specifically, 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), tris (2,3-dibromopropyl) isocyanurate, tris (tribromoneopentyl) phosphate, and the like.
Among these, in particular, tetrabromobisphenol A bis (2,3-dibromopropyl ether) and / or tris (2,3-dibromopropyl) isocyanurate is easily available, and the foam thermal weight reduction temperature described later is It is most preferably used because it is easy to control.

  The content of the halogen-based flame retardant used in the present invention is foamed so that the thermal weight reduction start temperature of the halogen-based flame retardant in the foam is in the range described later, and the flame retardancy specified in JIS A9511 is obtained. It is appropriately adjusted according to the additive amount, the foam density, the type or amount of other additives, and is generally preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the styrene resin. More preferably, it is 0.5-15 weight part, More preferably, it is 1-10 weight part. When the content of the halogenated flame retardant is less than 0.1 parts by weight or more than 20 parts by weight, it is difficult to set the thermal weight reduction start temperature of the halogenated flame retardant in the styrene resin foam within the range described below. As a result, there is a tendency that it is difficult to obtain good characteristics as a foamed product such as flame retardancy which is the object of the present invention.

  In the present invention, in the halogen-based flame retardant in the styrene resin foam, the thermogravimetric decrease starting temperature measured by the following method (measured under a nitrogen stream (50 ml / min) at a heating rate of 10 ° C./min) The flame retardance which was excellent in that it is 300 degrees C or less is acquired.

  The thermogravimetric decrease starting temperature in the present invention may be measured (thermogravimetric method) using a general thermogravimetric measuring device, for example, TGA-50 or DTG-50 manufactured by Shimadzu Corporation. Moreover, although a foam is used as it is as a measurement sample, after pressing at normal temperature, it is preferable to measure it as a shape that does not contain bubbles as much as possible by folding using tweezers.

As shown in FIG. 1, the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam in the present invention is plotted on the vertical axis with the measured sample weight being 100%, and the temperature is plotted on the horizontal axis. In the thermogravimetric decrease curve, as the temperature of the intersection of the tangent before the start of weight decrease in the thermogravimetric decrease curve confirmed to be derived from the flame retardant by the following method and the tangent of the portion with the largest slope of the weight decrease curve Yes.
In addition, the thermogravimetric decrease curve derived from the halogen-based flame retardant in the foam is measured using a thermogravimetric-mass spectrometry simultaneous measurement device (TG-MS) or the like, and the flame retardant or a decomposition product thereof is generated. This can be confirmed by identifying the temperature range. The thermogravimetric decrease starting temperature can be obtained from the tangential intersection temperature in the temperature range.

  By setting the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam to 300 ° C. or lower, when the styrene resin foam is heated, combustible gas is generated due to decomposition of the styrene resin. However, it is considered that the flame retardant effect is obtained because the halogen-based flame retardant decomposes or volatilizes quickly enough to contribute to dilution of the flammable gas or oxygen in the gas phase, suppression of radical reaction, and the like.

  The method of setting the thermogravimetric flame retardant starting temperature of the halogen-based flame retardant in the styrene resin foam to 300 ° C. or lower is not particularly limited, but the thermo-gravimetric flame retardant starting temperature of the halogen flame retardant alone (halogen-based resin). In addition to using a flame retardant alone under a nitrogen stream (50 ml / min) measured at a rate of temperature increase of 10 ° C./min) of 300 ° C. or less, the halogen-based flame retardant alone has a thermal weight reduction start temperature of 300 Even in the case of using a material having a temperature higher than 0 ° C., for example, a combination of an auxiliary agent such as a decomposition accelerator or a pretreatment method such as heating before adding the halogen flame retardant to a resin, foam Means such as changing conditions such as temperature and pressure during the production can be mentioned.

  When the thermal weight reduction start temperature of the halogen flame retardant in the styrene resin foam exceeds 300 ° C., there is a tendency that a sufficient flame retardant effect cannot be obtained. Moreover, the thermogravimetric flame retardant starting temperature of the halogen-based flame retardant in the styrene-based resin foam is preferably 260 to 280 ° C. from the viewpoint of achieving better physical properties such as flame retardancy and heat resistance. preferable.

  In the present invention, in particular, the thermal weight reduction start temperature of the halogenated flame retardant in the styrenic foam, the thermal weight reduction start temperature of the halogenated flame retardant alone (the halogenated flame retardant alone under a nitrogen stream ( 50 ml / min), measured at a heating rate of 10 ° C./min) is 5 ° C. or more, and excellent flame retardancy is obtained while maintaining the thermal stability of the styrene resin foam. This is preferable.

The blowing agent used in the present invention is not particularly limited, but is selected from the group consisting of hydrocarbons and halogenated hydrocarbons and has an ozone depletion coefficient of 0 from the viewpoint of environmental compatibility. It is preferable to use the above compound (hereinafter also referred to as a compound having an ozone depletion coefficient of 0) and, if necessary, other foaming agents (hereinafter also referred to as other foaming agents). 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.

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

Examples of the halogenated hydrocarbon used in the present invention and having an ozone depletion coefficient of 0 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-tetrafluoroethane (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- hexafluoropropane _{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- pentafluoro propane _{(HFC-245cb: CF 3 CF} 2 CH 3), 1,1,1,3,3- pentafluoropropane _{(HFC-245fa: CF 3 CH} 2 CHF 2), 1,1,1,3,3- And 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.

  Further, when a saturated hydrocarbon having 3 to 5 carbon atoms is used, the bubble structure constituting the foam includes bubbles (small bubbles) having a bubble diameter of approximately 0.25 mm or less and bubbles having a relatively small bubble diameter. From the viewpoint of heat insulation, it is preferable to have a characteristic bubble structure in which bubbles having a relatively large bubble diameter (large bubbles) having a diameter of approximately 0.3 mm to 1 mm are mixed in a sea-island shape.

  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, by using another foaming agent other than at least one compound selected from the group consisting of hydrocarbons and halogenated hydrocarbons and having an ozone depletion coefficient of 0, styrene resin foam production The plasticizing effect at the time and the foaming aid effect are obtained, the extrusion pressure is reduced, and the styrene resin foam can be stably produced. However, depending on the various properties of the foam, such as the desired foaming ratio and flame retardancy, the amount used can be limited.

  Other foaming agents used in the present invention are not particularly limited. For example, ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, n-butyl ether, diisopropyl ether, furan, furfural, 2-methyl furan, tetrahydrofuran, tetrahydropyran, dimethyl ketone, methyl ethyl ketone, diethyl ketone, methyl n- Ketones such as 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, methanol, ethanol, propyl alcohol, i-propyl alcohol , Alcohols such as butyl alcohol, i-butyl alcohol, t-butyl alcohol, formic acid methyl ester, formic acid ethyl ester, formic acid propylene Organic foaming agents such as esters, butyl formate, amyl formate, carboxylic acid esters such as methyl propionate and ethyl propionate, alkyl halides such as methyl chloride and ethyl chloride, such as nitrogen, water and carbon dioxide Inorganic foaming agents such as chemical foaming agents such as azo compounds and tetrazole can be used. 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 Or water and a carbon dioxide are preferable from points, such as heat insulation mentioned later. Among other blowing agents, dimethyl ether, water 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 styrene resin foam of the present invention, the amount of the foaming agent to be added or injected into the styrene resin is appropriately changed according to the setting value of the expansion ratio, etc. When the total amount is 100 parts by weight of styrene resin, it is preferably 1 to 20 parts by weight. If the addition amount of the foaming agent is less than 1 part by weight, the foaming ratio is low, and characteristics such as light weight and heat insulation as a styrene resin foam may be difficult to be exhibited. Due to the amount of foaming agent, defects such as voids may occur in the styrene resin foam, or the flame retardancy may be reduced depending on the type of foaming agent.

  In the foaming agent added in the present invention, 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 with respect to 100% by weight of the total amount of the foaming agent. That's it. (In other words, the upper limit of mixing amount of the other blowing agent 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 the blowing agent.) The ozone depletion coefficient is 0. When the amount of the one or more compounds is less than 10% by weight, the obtained foam may have poor heat insulation properties. When the amount of the other foaming agent exceeds 90% by weight, for example, when obtaining an extruded foam, if the compatibility with the styrenic resin is high, the plasticity is too high, and the styrenic 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. Control tends to be difficult, and some flammable foaming agents tend to reduce the flame retardancy of the foam.

In the foaming agent added in the present invention, the upper limit amount of the compound having an ozone depletion coefficient of 0 is 100% from the viewpoint of obtaining a foam of good quality such as stable foam production and appearance. Preferably it is 90 weight% or less with respect to weight%, More preferably, it is 80 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, when water is used as the other foaming agent, processability, bubbles having a bubble diameter of 0.25 mm or less (hereinafter also referred to as small bubbles) and bubbles having a bubble diameter of 0.3 to 1 mm (hereinafter referred to as “bubbles”) The amount of water mixed is preferably 1 to 80% by weight, more preferably 2 to 70% by weight, particularly preferably 3 to 100% by weight of the total amount of the foaming agent. 60% by weight.

  In the present invention, when other foaming agents other than water (such as at least one ether selected from the group consisting of dimethyl ether, diethyl ether and methyl ethyl ether) are used in combination as other foaming agents, From the viewpoint of the properties and the generation of small bubbles and large bubbles, the amount of the other blowing agent to be mixed is preferably 1 to 75% by weight of water and other blowing agent 79 other than water with respect to 100% by weight of the total amount of the blowing agent. ~ 5 wt%, more preferably 2 to 70 wt% water and 78 to 10 wt% other blowing agents other than water, particularly preferably 3 to 65 wt% water and 77 to 15 wt% other blowing agents other than water It is.

  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.

  The styrenic resin foam obtained by the present invention is not particularly limited, but often contains a foaming agent remaining, preferably a group consisting of hydrocarbon and halogenated hydrocarbon as the foaming agent. One or more compounds which are selected and have an ozone depletion coefficient of 0 are contained. However, the remaining content of the foaming agent in the obtained styrene resin foam is the type and amount of the foaming agent, the permeability of the foaming agent in the styrene resin foam, the magnification of the styrene resin foam or It depends on the density and required thermal insulation performance. In particular, depending on the permeability of the foaming agent in the styrene-based resin foam, the remaining amount decreases with time, and the gas in the foam bubbles is replaced with air or the like. Therefore, a foam produced by using a compound having a high permeability and consequently having a very small amount of the compound remaining in the styrene resin foam is also included in the scope of the present invention.

  However, in the case where a high degree of heat insulation performance is required, such as two types of extruded polystyrene foam insulating plates specified in JIS A9511, and further three types, the composition of the remaining foaming agent in the obtained styrene resin foam is: One or more compounds selected from the group consisting of hydrocarbons and halogenated hydrocarbons and having an ozone depletion coefficient of 0 with respect to the total amount of the remaining blowing agent are preferably 100 to 1% by weight, more preferably 100 to 5% by weight, more preferably 100 to 10% by weight, particularly preferably 100 to 20% by weight, while other blowing agents are preferably 0 to 99% by weight, more preferably 0 to 95% by weight, More preferably, it is 0 to 90% by weight, and particularly preferably 0 to 80% by weight. When the amount of one or more compounds having an ozone depletion coefficient of 0 in the foaming agent remaining in the styrene resin foam is less than 1% by weight, two types of extruded polystyrene foam heat insulating plates specified by JIS A9511, and further 3 There is a tendency that high heat insulation performance such as seeds is difficult to obtain.

  Furthermore, when two or three types of extruded polystyrene foam heat insulating plates require high heat insulation performance, they are selected from the group consisting of hydrocarbons and halogenated hydrocarbons in the foam, and ozone destruction In general, the residual content of at least one compound having a coefficient of 0 is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the styrene resin foam. In particular, when higher heat insulation performance is required, such as three types of extruded polystyrene foam heat insulating plates, 2 to 10 weights are more preferable for one or more compounds that are hydrocarbons and have an ozone depletion potential of 0. Specifically, 2 to 9 parts by weight is more preferable for propane, 3 to 8 parts by weight is particularly preferable for propane, and 1.5 to 9 parts by weight is further preferable for n-butane or i-butane, Particularly preferably 2 to 8 parts by weight, n-pentane, i-pentane and c-pentane are preferably 2 to 9 parts by weight, and one or more compounds which are halogenated hydrocarbons and have an ozone depletion potential of 0 2 to 10 parts by weight, specifically 2 to 10 parts by weight for hydrofluorocarbons such as 1,1,1,2-tetrafluoroethane.

  In the present invention, in order to obtain an excellent flame retardant effect by controlling the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam to an intended range, Al, Ti as a flame retardant aid. , V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce, selected from the group consisting of oxides, halides, and phosphates At least one metal compound can be used.

  Oxides and halides of Al, Ti, V, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce of the present invention And at least one metal compound selected from the group consisting of phosphates, Al, Mn, Fe, Ni, Cu, Zr from the viewpoint of excellent flame retardant aid effect and good handleability of the compound itself. Or, at least one compound selected from the group consisting of oxides, halides and phosphates of Mo is preferable, and iron oxide is more preferable because it is easily available and has a particularly high flame retardant aid effect.

  Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxides and halides used in the present invention And the content of at least one metal compound selected from the group consisting of phosphates controls the flame weight reduction start temperature of the halogen-based flame retardant in the foam within a predetermined range, and the flame retardant specified in JISA 9511 That can be adjusted appropriately according to the type of metal compound 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, so that the properties and physical properties can be obtained. However, in general, 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 more preferable with respect to 100 parts by weight of the styrene resin. There. Consists of oxides, halides and phosphates of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce When the content of at least one metal compound selected from the group is less than 0.0001 part by weight, good characteristics as a styrene resin foam such as flame retardancy aimed at by the present invention tend not to be obtained. On the other hand, if it exceeds 1 part by weight, heat resistance, flame retardancy, moldability during foam production, surface properties, etc. may be impaired.

  In the present invention, halogen flame retardant and oxidation of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce In addition, at least one metal compound selected from the group consisting of a product, a halide, and a phosphate, and further, a thermal weight reduction start temperature of the halogen flame retardant in the styrene resin foam can be controlled to a desired value. Thus, one or more compounds selected from the group consisting of phosphorus-containing compounds other than phosphoric acid metal salts, nitrogen-containing compounds, boron-containing compounds, and sulfur-containing compounds can be used in combination.

  Combining at least one compound 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, combustible hydrocarbons and halogenated hydrocarbons. Foaming at least one compound selected from the group and having an ozone depletion coefficient of 0 (specifically, a saturated hydrocarbon having 3 to 5 carbon atoms such as propane, n-butane, i-butane, etc.) Even if it is used for the agent and exhibits high heat insulation performance corresponding to two or three types of extruded polystyrene foam heat insulating plates, halogen flame retardants and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, At least one metal compound selected from the group consisting of oxides, halides and phosphates of Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce is contained. It can not be added to achieve a high degree of flame retardancy prescribed in JIS A9511 thing.

  The phosphorus-containing compound other than the metal phosphate used in the present invention is a compound containing a phosphorus atom, which is a halogen-based flame retardant, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, A synergistic effect can be exerted on at least one metal compound selected from the group consisting of oxides, halides and phosphates of Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce. If it is a compound, there will be no restriction | limiting in particular. Examples thereof include phosphate, phosphonate, phosphinate, phosphite, phosphoric acid, phosphonic acid, phosphinic acid or derivatives thereof, melamine salt, ammonium salt, phosphazene or derivatives thereof, phosphonitrile or derivatives thereof, and the like.

  Specific examples of the phosphorus-containing compound other than the metal phosphate include, for example, trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl acid phosphate , Aliphatic hydrocarbon monophosphates such as 2-methacryloyloxyethyl acid phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, tris (phenylphenyl) phosphate, trinaphthyl phosphate, Cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, (Isopropylphenyl) phenyl phosphate, diphenyl-2-acryloyloxyethyl phosphate, aromatic hydrocarbon monophosphates such as diphenyl-2-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, hydroquinone / dixylenyl phosphate, hydroquinone / dicresyl phosphate, resorcinol / polyphenyl phosphate, resorcinol / poly (Di-2,6-xylyl) phosphate Condensed phosphate esters such as Sphenol A / polycresyl phosphate, hydroquinone poly (2,6-xylyl) phosphate, melamine phosphate, melamine phosphite, melamine pyrophosphate, ammonium phosphate, ammonium pyrophosphate, ammonium phosphate Amide, Phosphoric acid amide, Piperazine diphosphite, Piperazine phosphite, Piperazine pyrophosphate, Guanazole phosphite, Phosphazene, Melamine polyphosphate, Melan polyphosphate, Melem polyphosphate, Ammonium polyphosphate, Ammonium polyphosphate, Polyphosphorus Examples thereof include phosphorus-containing nitrogen-containing compounds such as acid amides, polyphosphazenes, and phosphonitriles. 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 amount of the phosphorus-containing compound other than the metal phosphate in the present invention is controlled by controlling the thermal weight reduction start temperature of the halogen-based flame retardant in the foam to a desired range, and the flame retardancy and various properties defined in JIS A9511. In order to obtain physical properties, halogen flame retardant, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or At least one metal compound selected from the group consisting of Ce oxides, halides and phosphates, and the type and content of the foaming agent, the density of the resulting foam, etc. are appropriately adjusted. 0.1-10 weight part is preferable with respect to 100 weight part of resin, 0.3-9 weight part is more preferable, 0.5-8 weight part is further more preferable. 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 a compound containing a nitrogen atom, which is a halogen flame retardant and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Any compound that can exhibit a synergistic effect on at least one metal compound selected from the group consisting of oxides, halides and phosphates of Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce. There is no particular limitation. Examples thereof include triazine skeleton-containing compounds, cyanuric acid or isocyanuric acid and derivatives thereof, guanidine compounds, azo compounds, and tetrazole compounds.

  Specific examples of nitrogen-containing compounds include triazine skeleton-containing compounds such as melamine, melam, melem, melon, and methylolmelamine or derivatives thereof, cyanuric acid, methyl cyanurate, diethyl cyanurate, trimethyl cyanurate, triethyl cyanurate, isocyanuric acid. Methyl isocyanurate, N, N′-diethyl isocyanurate, trismethyl isocyanurate, trisethyl isocyanurate, bis (2-carboxyethyl) isocyanurate, 1,3,5-tris (2-carboxyethyl) isocyanurate, Cyanuric acid such as tris (2,3-epoxypropyl) isocyanurate, isocyanuric acid or derivatives thereof, triazine skeleton-containing compound such as melamine, cyanuric acid or isocyanuric acid and derivatives thereof Ranaru salts such as 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 amount of the nitrogen-containing compound added in the present invention is such that the thermal weight reduction start temperature of the halogen-based flame retardant in the foam is controlled within a desired range, and flame retardancy and various physical properties defined in JIS A9511 are obtained. In addition, halogen flame retardants, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxides, It is appropriately adjusted depending on at least one metal compound selected from the group consisting of halides and phosphates, the type and content of the foaming agent, the density of the obtained foam, and the like. On the other hand, 0.1-10 weight part is preferable, 0.3-9 weight part is more preferable, 0.5-8 weight part is further more 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 a compound containing a boron atom, which is a halogen flame retardant and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Any compound that can exhibit a synergistic effect on at least one metal compound selected from the group consisting of oxides, halides and phosphates of Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce. There is no particular limitation. For example, boric acid, borax, metal borate, boron oxide, boron phosphate, borosilicates and the like can be mentioned.

  Specific examples of boron-containing compounds include boric acid, borax, zinc borate, barium borate, magnesium borate, calcium borate, aluminum borate, strontium borate, zirconium borate, tin borate, and other metal borate. Examples thereof include salts, and derivatives such as hydrates of these compounds, and boron oxides such as diboron dioxide, diboron trioxide, tetraboron trioxide, and 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 such that the thermal weight reduction start temperature of the halogen-based flame retardant in the foam is controlled within a desired range so that the flame retardancy and various physical properties defined in JIS A9511 are obtained. In addition, halogen flame retardants, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxides, It is appropriately adjusted depending on at least one metal compound selected from the group consisting of halides and phosphates, the type and content of the foaming agent, the density of the obtained foam, and the like. On the other hand, 0.1-10 weight part is preferable, 0.3-9 weight part is more preferable, 0.5-8 weight part is further 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 a compound containing a sulfur atom, which is a halogen flame retardant and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Any compound that can exhibit a synergistic effect on at least one metal compound selected from the group consisting of oxides, halides and phosphates of Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce. There is no particular limitation. 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 such that the thermogravimetric reduction start temperature of the halogen-based flame retardant in the foam is controlled within a desired range, and flame retardancy and various physical properties defined in JIS A9511 are obtained. In addition, halogen flame retardants, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxides, It is appropriately adjusted depending on at least one metal compound selected from the group consisting of halides and phosphates, the type and content of the foaming agent, the density of the obtained foam, and the like. On the other hand, 0.1-10 weight part is preferable, 0.3-9 weight part is more preferable, 0.5-8 weight part is further more 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, a phosphorus-containing compound, nitrogen-containing compound, boron-containing compound or sulfur-containing compound other than the metal phosphate is a surface treatment agent (for example, various thermosetting resins, various thermoplastic resins, silane coupling agents, titanium One or two or more compounds selected from system compounds, inorganic compounds, and the like may be suitably used.

  In other words, in the case of using a phosphorus-containing compound other than the phosphoric acid metal salt, a nitrogen-containing compound, a boron-containing compound or a sulfur-containing compound, when water is used as another foaming aid at the time of producing an extruded foam, A compound that does not hinder the effect of generating the small bubbles and large bubbles in the styrene-based resin foam is preferable. For example, it is hardly soluble in water or has a solubility in water of 10 in a temperature range near room temperature (around 10 to 30 ° C.). A weight percent or less compound is preferred. When the solubility in water is higher than 10% by weight, the effect of generating the small bubbles and large bubbles tends to be inhibited. When the solubility in water is higher than 10% by weight, or when there is a tendency to inhibit the effect of generating small bubbles and large bubbles, it may be improved by applying a surface coating treatment. It is preferable to use a surface-treated compound as long as the temperature reduction start temperature of the halogenated flame retardant in the body can be controlled to a desired value.

  The cell structure of the styrene resin foam of the present invention is not particularly limited. The bubble structure is composed of bubbles having a bubble diameter of about 0.01 to 1 mm, but most of the bubbles are substantially composed of bubbles having similar bubble diameters. Examples of the structure are classified into three or more types. In particular, in order to exhibit high heat insulation performance corresponding to two or three types of extruded polystyrene foam heat insulating plates, in the case where most of the bubbles are composed of bubbles having similar cell diameters, depending on the average cell diameter, It is necessary to contain a relatively large amount of foaming agent having a low thermal conductivity. On the other hand, when the cell diameters of the bubbles are roughly classified into two or more types, especially when the bubble cell structure of the foam is a cell having a relatively small bubble diameter of approximately 0.25 mm or less. (Small bubbles) and a relatively large amount of bubbles (large bubbles) with a bubble size of approximately 0.3 mm to 1 mm are mixed in a sea-island shape. High heat insulation is realized even if one or more kinds of compounds in which is 0 remains. In particular, when using one or more compounds having a flammable ozone depletion coefficient of 0, the latter cell structure is preferable. Such a cell structure can be formed, for example, by using water as another foaming agent during extrusion foaming.

  In the present invention, when water is used as the other foaming agent, a water-absorbing substance capable of absorbing this water within a range in which the thermal weight reduction start temperature of the halogen flame retardant in the foam can be controlled to an intended value. It is preferable to use them at the same time. Specific examples of the water-absorbing substance include, for example, water-absorbing or water-swelling layered silicates such as smectite and swellable fluorinated mica or organically treated products thereof, water-absorbing polymers, AEROSIL manufactured by Nippon Aerosil Co., Ltd., etc. And anhydrous silica having a silanol group. By adding one or more of these water-absorbing substances, the action of generating small bubbles and large bubbles, which will be described later, can be further improved in the styrene-based resin foam. Formability, productivity and heat insulation performance are further improved.

  The water-absorbing substance used here is considered to absorb water that is not compatible with the styrenic resin to form a gel, which can be uniformly dispersed in the styrenic resin in the gel state. used.

  The content of the water-absorbing substance used in the present invention is appropriately adjusted depending on the amount of water added and the like within a range in which the thermal weight reduction start temperature of the halogen-based flame retardant in the foam can be controlled to an expected value. However, it is preferably 0.2 to 10 parts by weight, more preferably 0.3 to 8 parts by weight, and particularly preferably 0.5 to 7 parts by weight with respect to 100 parts by weight of the styrenic resin. If the content of the water-absorbing substance is less than 0.2 parts by weight, the amount of water adsorbed by the water-absorbing substance may be insufficient, and pores may be generated due to poor dispersion of water in the extruder, resulting in a defective molded body. If it exceeds the parts by weight, poor dispersion of the water-absorbing substance occurs in the extruder, resulting in air bubble unevenness, which may cause deterioration and variation in the heat insulation performance of the foam.

  The layered silicate used in the present invention mainly comprises a tetrahedral sheet of silicon oxide and an octahedral sheet of mainly metal hydroxide, and the tetrahedral sheet and the octahedral sheet form a unit layer, and the unit layer alone In addition, a plurality of layers may be laminated between layers via a cation to form primary particles, or aggregate particles of primary particles (secondary particles) may be present. Examples of layered silicates include smectite clay and swellable mica.

The smectite clay is represented by the following general formula (1)
X _0.2 to _0.6 Y ₂ to ₃ Z ₄ O ₁₀ (OH) ₂ · nH ₂ O ··· General formula (1)
(However, X is at least one selected from the group consisting of K, Na, 1 / 2Ca, and 1 / 2Mg, and Y is a group consisting of Mg, Fe, Mn, Ni, Zn, Li, Al, and Cr. And Z is at least one selected from the group consisting of Si and Al, where H ₂ O represents a water molecule bonded to an interlayer ion, and n is an interlayer ion. And varies significantly depending on the relative humidity).

  Specific examples of the smectite group clay include, for example, montmorillonite, beidellite, nontronite, saponite, iron saponite, hectorite, soconite, stevensite, bentonite, or the like, or a substitution product, derivative thereof, or a mixture thereof. .

Further, the swellable mica is represented by the following general formula (2)
X _0.5 to _1.0 Y ₂ to ₃ (Z ₄ O ₁₀ ) (F, OH) ₂ ... General formula (2)
(However, X is at least one selected from the group consisting of Li, Na, K, Rb, Ca, Ba, and Sr, and Y is selected from the group consisting of Mg, Fe, Ni, Mn, Al, and Li) And Z is one or more selected from the group consisting of Si, Ge, Al, Fe, and B.) or natural or synthesized.

  These are water, a polar organic compound that is compatible with water at an arbitrary ratio, and a substance that swells in a mixed solvent of water and the polar organic compound. For example, lithium teniolite, sodium Type teniolite, lithium type tetrasilicon mica, sodium type tetrasilicon mica and the like, or a substituted product, a derivative thereof, or a mixture thereof.

Some of the above swellable mica have a structure similar to vermiculites, and such vermiculites and the like can also be used. The vermiculite-equivalent products are classified into 3 octahedron type and 2 octahedron type, and the following general formula (3)
_{(Mg, Fe, Al) 2} ~ 3 (Si 4-x Al x) O 10 (OH) 2 · (M +, M 2+ 1/2) x · nH 2 O ······ formula ( 3)
(Wherein M is an exchangeable cation of an alkali or alkaline earth metal such as Na and Mg, x = 0.6 to 0.9, and n = 3.5 to 5). .

  Swellable layered silicates may be used alone or in combination of two or more. Among these, from the viewpoint of dispersibility in the obtained foam, smectite group clay and swellable mica are preferable, and more preferably, between layers such as montmorillonite, bentonite, hectorite, synthetic smectite, and swellable fluorine mica. Swellable mica having sodium ions is preferred.

  Typical examples of bentonite include natural bentonite and purified bentonite. Also, organic bentonite can be used. The smectite in the present invention includes montmorillonite-modified products such as anionic polymer-modified montmorillonite, silane-treated montmorillonite, and highly polar organic solvent composite montmorillonite.

  The content of smectite such as bentonite in the present invention is appropriately adjusted depending on the amount of water added and the like within a range where the thermogravimetric reduction starting temperature of the halogen-based flame retardant in the foam can be controlled to an expected value. Is preferably 0.2 to 10 parts by weight, more preferably 0.3 to 8 parts by weight, particularly preferably 0.5 to 7 parts by weight, and most preferably 1 to 5 parts by weight based on 100 parts by weight of the styrenic resin. Parts by weight. When the smectite content is less than 0.2 parts by weight, the amount of water adsorbed by the smectite is insufficient with respect to the amount of water injected, and pores are generated due to poor dispersion of water in the extruder, which tends to cause a molded article failure. On the other hand, when the amount exceeds 10 parts by weight, the amount of the inorganic powder present in the styrene resin becomes excessive, so that uniform dispersion in the styrene resin becomes difficult, and bubble unevenness tends to occur. Furthermore, it tends to be difficult to maintain closed cells. Accordingly, there is a tendency that the heat insulation performance of the foam is deteriorated and uneven.

  The mixing ratio of water / smectite (bentonite) in the present invention is preferably a weight ratio of 0.02 to 20, more preferably 0.1 to 10, particularly preferably 0.15 to 5, most preferably 0.25. A range of ~ 2 is ideal.

  The average cell diameter in the styrene resin foam obtained in the present invention is preferably 0.05 to 1 mm, more preferably 0.06 to 0.6 mm, and particularly preferably 0.08 to 0.4 mm.

  Further, when water is used as the other foaming agent, in the styrenic resin foam, bubbles having a relatively small bubble diameter (small bubbles) mainly having a bubble diameter of 0.25 mm or less, and a bubble diameter being mainly 0.3. A foam having a characteristic bubble structure in which bubbles having a relatively large bubble diameter (large bubbles) of about ˜1 mm are mixed in a sea-island shape is obtained. Since the heat insulation performance of the obtained styrene resin foam is improved, it is preferable to use water as another foaming agent. When water is used as the other foaming agent, it may be used in combination with only one or more compounds having an ozone depletion coefficient of 0, but one or more compounds having an ozone depletion coefficient of 0 and other than water A foaming agent comprising three or more components in combination with other foaming agents (for example, dimethyl ether, carbon dioxide, etc.) is preferable because the foamability and moldability of the foam are further improved.

  Furthermore, in the foam having a specific cell structure in which small bubbles having a bubble diameter of 0.25 mm or less and large bubbles having a bubble diameter of 0.3 to 1 mm are mixed, the ratio of the area of the small bubbles to the cross-sectional area of the foam (Occupied area ratio per unit cross-sectional area) (hereinafter referred to as small bubble area ratio) is preferably 5 to 95%, more preferably 10 to 90%, particularly preferably 20 to 80%, and most preferably 25 to 70. %.

  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 Additives such as a light-resistant stabilizer such as an agent, benzotriazoles and hindered amines, a flame retardant other than the above, an antistatic agent, and a colorant such as a pigment can be contained.

  As the flame retardant aid, the halogen-based flame retardant in the foam is controlled to have a thermogravimetric reduction start temperature within a predetermined range, and the flame retardant and various physical properties defined in JIS A9511 are obtained. Flame retardants and oxides, halides and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce A flame retardant aid such as diphenylalkane that decomposes by heat and generates radicals is not particularly limited as long as it is a substance that exhibits a synergistic effect on at least one metal compound selected from the group consisting of phosphates Is preferred.

  Further, in order to more stably perform extrusion foaming at the time of producing the extruded foam, the 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-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di -T-butyl-4-hydroxybenzyl) isocyanurate and other hindered phenol antioxidants, triphenyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,4- Di-t-butylphenyl) pentaerythritol diphosphite, bisstearyl pentaerythritol diphosphite, bis (2,4-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tetrakis (2,4- Di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphona Phosphorus stabilizers such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer, alkylated diphenylamine, octylated diphenylamine, 4,4′-bis (α, α-dimethylbenzyl) diphenylamine, etc. It is preferable to add a sulfur stabilizer such as an amine stabilizer, 3,3-thiobispropionic acid didecyl ester, 3,3′-thiobispropionic acid dioctadecyl ester.

  Although it does not specifically limit regarding the manufacturing method of the styrenic resin foam of this invention, Since higher heat insulation is obtained, it is preferable to manufacture by extrusion foaming.

  The styrene resin foam of the present invention comprises a styrene resin and a halogen flame retardant, and further, if necessary, Al, Ti, V, Cr, Mn, Fe, Co, 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 halides and phosphates, phosphorus-containing compounds other than metal phosphates, nitrogen-containing compounds, boron-containing compounds A compound, a sulfur-containing compound, or other additive is supplied to a heating and melting means such as an extruder, and a foaming agent is added to a styrenic resin under high-pressure conditions at any stage to form a fluidized gel. It is produced by cooling to a suitable temperature and extruding and foaming the fluid gel through a die into the low pressure region to form a foam.

As a procedure for adding an additive such as a styrene resin and a foaming agent when heat-melting the additive such as a styrene resin and a foaming agent, for example,
(Ii) Halogen flame retardant to styrene resin, and further, if necessary, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, At least one metal compound selected from the group consisting of oxides, halides and phosphates of W, Os, Pt or Ce, phosphorus-containing compounds other than metal phosphates, nitrogen-containing compounds, boron-containing compounds, sulfur-containing compounds, or After mixing other additives, heat melt
(B) Styrenic resin and halogen flame retardant, and if necessary, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, At least one metal compound selected from the group consisting of oxides, halides and phosphates of W, Os, Pt or Ce, phosphorus-containing compounds other than metal phosphates, nitrogen-containing compounds, boron-containing compounds, sulfur-containing compounds, or After mixing one or more additives selected from other additives, the mixture is heated and melted, and the remaining additives are added as they are or liquefied or melted as necessary, and heated and mixed.
(Ha) Halogen flame retardant in styrene resin in advance, and if necessary, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn At least one metal compound selected from oxides of W, Os, Pt or Ce, halides and phosphates, phosphorus-containing compounds other than metal phosphates, nitrogen-containing compounds, boron-containing compounds, sulfur-containing compounds, Alternatively, after mixing one or more additives selected from other additives, a heated and melted composition is prepared, and then the composition, the remaining additives, and, if necessary, the styrenic resin are renewed. Mix, feed to extruder and melt by heating.
However, it is not limited to these.

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

  The heating temperature may be equal to or higher than the temperature at which the styrenic resin used melts, but is preferably a temperature at which molecular degradation of the resin due to the influence of a flame retardant is suppressed as much as possible, for example, about 150 to 260 ° C.

  The melt-kneading time varies depending on the extrusion amount per unit time, the melt-kneading means, etc., and thus cannot be determined unconditionally. However, the time required for uniformly dispersing and mixing the styrene 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. However, in order to suppress the molecular degradation of the resin as much as possible, it is preferable to use a low shear type screw for the screw shape.

  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 preferred.

  A styrene-based resin foam containing a halogen-based flame retardant according to the present invention, wherein the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene-based resin foam (in a nitrogen stream (50 ml / min), the temperature rise The styrenic resin foam characterized by a measurement at a speed of 10 ° C./min) is 300 ° C. or less can be regenerated and used again for molding. For example, the regenerated styrene resin composition obtained by pulverizing the styrene resin foam of the present invention and melting and pelletizing with an extruder is used as a part of the styrene resin, so-called new styrene resin. And extrusion foaming is possible. The upper limit amount of the regenerated styrene resin composition is appropriately adjusted within a range in which the thermal weight reduction start temperature of the halogen flame retardant in the styrene resin foam can be controlled to an expected value. An example is 200 parts by weight, preferably 150 parts by weight, based on 100 parts by weight of the new styrenic resin.

  Next, although the thermoplastic resin extrusion foam of this invention is demonstrated still 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. (However, the small bubble area ratio (%) is the area ratio.)

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)
B: Halogen flame retardant B-1: Tetrabromobisphenol A-bis (2,3-dibromopropyl ether) (manufactured by Teijin Chemicals Ltd., Fireguard 3100)
B-2: Decabromodiphenyl oxide (manufactured by Tosoh Corporation, frame cut 110R)
B-3: Tris (2,3-dibromopropyl) isocyanurate (manufactured by Nippon Kasei Co., Ltd., TAIC-6B)
B-4: Hexabromocyclododecane (manufactured by ALBEMALLE CORPORATION, SAYTEX HP-900)
C: Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxides, halides and phosphates At least one metal compound C-1 selected from the group consisting of: iron oxide (Fe ₂ O ₃ , reagent manufactured by Wako Pure Chemical Industries, Ltd.)
D: Phosphorus-containing compound other than metal phosphate, nitrogen-containing compound, boron-containing compound or sulfur-containing compound D-1: Triphenyl phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., TPP)
D-2: Isocyanuric acid (manufactured by Shikoku Kasei Co., Ltd., ICA-P)
D-3: Boron oxide (reagent manufactured by Wako Pure Chemical Industries, Ltd.)
D-4: p-Toluenesulfonic acid monohydrate (Reagent manufactured by Wako Pure Chemical Industries, Ltd.)
E: foaming agent; at least one compound selected from the group consisting of hydrocarbons and halogenated hydrocarbons and having an ozone depletion coefficient of 0 E-1: Propane (Iwatani Co., Ltd., odorless propane)
E-2: Isobutane (Mitsui Chemicals, Isobutane)
E-3: HFC-134a (manufactured by Daikin Industries, Ltd., HFC-134a)
F: Other foaming agent F-1: Dimethyl ether (Mitsui Chemicals, dimethyl ether)
F-2: Water G: Other additives G-1: Talc (manufactured by Hayashi Kasei Co., Ltd., Talcan powder)
G-2: Barium stearate (manufactured by Sakai Chemical Industry Co., Ltd., barium stearate)
G-3: Bentonite (Toyosumi Mining Co., Ltd., Wengel 23)
G-4: AEROSIL (Nippon Aerosil Co., Ltd., AEROSIL)
G-5: Stabilizer (IRGANOX B911 (hindered phenol antioxidant IRGANOX1076: octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate manufactured by Ciba Specialty Chemicals Co., Ltd.) Phosphorus stabilizer IRGAFOS 168: 1: 1 mixture of tris (2,4-di-t-butylphenyl) phosphite)

  Evaluation / measurement methods for the obtained foam are as follows.

(1) Thermogravimetric decrease temperature It measured with the following procedure using the thermogravimetry apparatus (Shimadzu Corporation make, DTG-50).
1) Thermal weight reduction start temperature of halogen flame retardant in styrene resin foam a) Take 3.5 ± 0.5 mg of the obtained styrene resin foam, press at room temperature, and then use tweezers Fold it in a shape that contains as little air bubbles as possible.
b) Place in an aluminum cell, raise the temperature from room temperature to 500 ° C. under a nitrogen stream (50 ml / min) under the temperature rising rate of 10 ° C./min, and measure the weight loss due to heating.
c) In the thermogravimetric decrease curve when the measured sample weight is taken as 100% on the vertical axis and the temperature on the horizontal axis, the tangent before the start of weight decrease in the weight decrease curve confirmed to be derived from the flame retardant, and the weight The temperature of the intersection with the tangent of the portion with the greatest slope of the decrease curve was determined and used as the heat decrease start temperature.
Evaluation was performed as follows.
○: 260 ° C. or more and 280 ° C. or less Δ: More than 280 ° C. or more than 280 ° C. and less than 300 ° C. x: More than 300 ° C. 2) Thermal weight reduction start temperature of halogen flame retardant alone a) 3 halogen flame retardant Collect 5 ± 0.5 mg.
b) Place in an aluminum cell, raise the temperature from room temperature to 500 ° C. under a nitrogen stream (50 ml / min) under the temperature rising rate of 10 ° C./min, and measure the weight loss due to heating.
c) Taking the measurement sample weight as 100% and taking the vertical axis, in the thermogravimetric reduction curve when the temperature is taken on the horizontal axis, obtain the temperature of the intersection of the tangent before the start of weight reduction and the tangent of the portion with the largest inclination, The thermogravimetric decrease starting temperature was used.
Regarding the halogen flame retardant, the range of decrease in the thermogravimetric decrease start temperature in the styrene resin foam relative to the thermal weight decrease start temperature of the halogen flame retardant alone (the thermal weight decrease start temperature of the halogen flame retardant alone) -(Thermogravimetric starting temperature of the halogenated flame retardant in the foam) was calculated and evaluated as follows.
○: The decrease width is 5 ° C. or more.
3) 5% thermal weight loss temperature of halogenated aliphatic group-containing compound a) Take 3.5 ± 0.5 mg of halogenated flame retardant.
b) Place in an aluminum cell, raise the temperature from room temperature to 500 ° C. under a nitrogen stream (50 ml / min) under the temperature rising rate of 10 ° C./min, and measure the weight loss due to heating.
c) The measured sample weight was taken as 100%, the vertical axis was taken, and the temperature at the time when the weight was reduced by 5% in the thermogravimetric reduction curve when the temperature was taken on the horizontal axis was obtained and taken as the 5% thermal weight reduction temperature.
The 5% thermal weight loss temperature of the halogenated aliphatic group-containing compound used in the examples was as follows.
B-1: Tetrabromobisphenol A-bis (2,3-dibromopropyl ether) → 295 ° C.
B-3: Tris (2,3-dibromopropyl) isocyanurate → 281 ° C.
B-4: Hexabromocyclododecane → 244 ° C.

(2) Combustibility The combustibility of the extruded foam was evaluated according to the following criteria using a test piece of 200 mm × 25 mm × 10 mm according to JIS A9511. 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 lines, but combustion stops within the limit line for the remaining one or more X: Combustion exceeds the limit line for all five lines (c) Combustion situation ◎: Combustion of foaming agent is completely absent Not seen ○: Combustion of the foaming agent is observed slightly Δ: Combustion of the foaming agent is observed, but no complete burning is achieved ×: Combustion of foams also seen, to burn down

(3) Thermal conductivity The thermal conductivity of the extruded foam was measured according to JIS A9511. 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 carried out on a foam that had passed 90 days after the production, after removing a 10 mm portion from the surface.

(4) Small bubble area ratio About the extrusion foam, the occupation area ratio per bubble foam cross-sectional area of the bubble which is the bubble diameter 0.25 mm or less in the thickness direction cross section was calculated | required as follows.
Here, the bubble having a bubble diameter of 0.25 mm or less is a bubble having an equivalent circle diameter of 0.25 mm or less.
(A) The longitudinal cross section of a foam is photographed by enlarging 30 times with a scanning electron microscope (product number: S-450, manufactured by Hitachi, Ltd.).
(B) An OHP sheet is placed on the photographed photograph, and a portion corresponding to a bubble having a diameter in the thickness direction larger than 7.5 mm (corresponding to a bubble having an actual size larger than 0.25 mm) is blackened on the photograph. Paint with ink and copy (primary processing).
(C) The primary processing image is taken into the image processing apparatus (Pierce Co., Ltd., product number: PIAS-II), and the dark color portion and the light color portion, that is, the portion painted with black ink are identified.
(D) Of the dark portion, the portion corresponding to the area of a circle having a diameter of 7.5 mm or less, that is, the diameter in the thickness direction is long, but the area is only a circle area having a diameter of 7.5 mm or less. The portion is lightened and the dark portion is corrected.
(E) Using “FRACTAREA (area ratio)” in the image analysis calculation function, the area ratio of the bubble diameter of 7.5 mm or less (light color portion divided by shading) in the entire image is obtained by the following equation.
Small bubble occupation area ratio (%) = (1−area of dark color portion / area of entire image) × 100

(5) Specific viscosity η _{sp of} styrene resin constituting the foam
The specific viscosity η _sp was determined by the following procedure.
(A) About 1 g of the foam sample is put in a test tube with a stopper, and about 30 ml of methyl ethyl ketone is added and dissolved. In the case of a sample that is difficult to dissolve, it is sufficiently dissolved by heating at 60 ° C. or lower.
(B) The test tube is stoppered and allowed to stand for 6 hours or more to precipitate insoluble matter (solid matter, gel).
(C) After standing, gently transfer the supernatant in the test tube to a beaker with a capacity of 100 ml or more.
(D) Using a magnetic stirrer, add several ml of ethanol while stirring the inside of the beaker, and confirm that the resin is precipitated. Further, ethanol is added in several ml, and when the precipitated resin does not redissolve, ethanol is slowly added in several drops to precipitate almost the entire amount of resin.
(E) Mix the precipitated resin with a stir bar or the like to make a lump and sink it to the bottom of the beaker. Wash lightly while pressing the resin on the bottom of the beaker.
(F) After washing, the supernatant in the beaker is discarded, and the resin content is placed on an aluminum foil and stretched to form a thin plate.
(G) Place the aluminum foil together in an oven at 70 ° C. and leave it for 12 hours or more to completely evaporate the solvent.
(H) A dried resin content of 250 mg (precise balance) is used as a sample in a test tube with a stopper, and 25 ml (precise balance using a whole pipette) of toluene is added and dissolved. When it is difficult to dissolve, it is sufficiently dissolved by heating at 60 ° C. or lower.
(I) Using a 10 ml sample (precise balance using a whole pipette), measure the relative viscosity with respect to toluene (special grade) at 30 ° C. using an Ostwald viscosity tube (water 30 ° C./50 S type).
The specific viscosity is calculated by the following formula.
Specific viscosity (η _sp ) = (sample passage time) / (toluene passage time) −1

(6) Heat resistance A foam cut into a rectangular parallelepiped of about 100 mm x 100 mm x 25 mm is cured for 2 weeks in a constant temperature and humidity chamber (temperature 25 ° C and humidity 50%) and then heated in an oven at 80 ° C for 24 hours. The volume change before and after that was determined.
The heat resistance was evaluated based on the following formula.
Volume change rate = [(sample volume after oven heating ÷ sample volume before oven heating) −1] × 100 (%)
A: Volume change rate is 15% or less.
Δ: Volume change rate is 15 to 30%.
X: Volume change rate is 30% or more.

(7) Density of foam After extruding the extruded foam 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 determined.
Formula: Foam density (g / cm ³ ) = foam weight (g) / foam volume (cm ³ )
And the unit was expressed in terms of (kg / m ³ ).

(8) Recyclability After the extruded foam was pulverized with a pulverizer, it was melted by heating at a cylinder temperature setting of 230 ° C. using a twin-screw extruder (manufactured by Nippon Steel Co., Ltd.) and pelletized.
Recyclability was evaluated based on the following formula.
Specific viscosity (η _sp ) retention rate = (specific viscosity of styrene resin (η _sp ) divided by heat melting and pelletizing after pulverization (η _sp ) ÷ specific viscosity of styrene resin originally used (η _sp )) × 100 (%)
○: Specific viscosity (η _sp ) retention is 75% or more.
Δ: Specific viscosity (η _sp ) retention is 60 to 75%.
X: Specific viscosity (η _sp ) retention is less than 60%.

Example 1
100 parts of styrene resin (A-1), 5 parts of tetrabromobisphenol A-bis (2,3-dibromopropyl ether) (B-1) as a halogen flame retardant, Al, Ti, V, Cr , Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce, at least one selected from the group consisting of oxides, halides, and phosphates Obtained by dry blending a mixture comprising 0.01 part of iron oxide (C-1), 0.5 part of talc (G-1) and 0.25 part of barium stearate (G-2) as a metal compound The obtained mixture was fed at a rate of about 70 kg / hr to an extruder in which an extruder having a diameter of 65 mm and a diameter of 90 mm was vertically connected. The mixture supplied to the 65 mm diameter extruder is heated to 200 ° C. and kneaded, and the resin temperature is cooled to 120 ° C. with a 90 mm diameter extruder connected to the extruder, and is attached to the tip of the 90 mm diameter extruder. Extruded into the atmosphere from the provided rectangular cross-section die having 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 28 kg / m ³ .
At this time, as the foaming agent, an extruder having a diameter of 65 mm was used so that the foaming agent composed of 50% propane (E-1) and 50% dimethyl ether (F-1) was 8 parts with respect to 100 parts of the styrene resin. Was pressed into the resin from the vicinity of the tip (the end connected to the end opposite to the end of the extruder having a diameter of 90 mm).
The properties of the obtained extruded foam are shown in Table 1.

(Examples 2 to 5)
Halogen flame retardant (B), Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxide Except that the values and the amounts of at least one metal compound (C), foaming agent (E) and other foaming agent (F) selected from the group consisting of halides and phosphates are shown in Table 1. A foam was obtained in the same manner as in Example 1.
The properties of the obtained extruded foam are shown in Table 1.

(Comparative Example 1)
A foam was obtained in the same manner as in Example 1 except that the types and addition amounts of the halogen-based flame retardant (B), the foaming agent (E), and the other foaming agent (F) were set to the values shown in Table 1.

  As is apparent from a comparison of Examples 1 to 5 and Comparative Example 1 which are examples of the present invention, according to the present invention, the thermogravimetric reduction start temperature of halogen flame retardant in a styrene resin foam ( By setting the temperature under a nitrogen stream (50 ml / min) at a heating rate of 10 ° C./min to 300 ° C. or less, a foam excellent in flame retardancy can be obtained, and in the styrene resin foam It can be seen that a foam having excellent heat resistance and recyclability can be obtained by further limiting the thermogravimetric decrease starting temperature of the halogen-based flame retardant and the 5% thermogravimetric decrease temperature of the halogenated aliphatic group-containing compound.

(Example 6)
100 parts of styrene resin (A-1), 5 parts of tetrabromobisphenol A-bis (2,3-dibromopropyl ether) (B-1) as a halogen flame retardant, Al, Ti, V, Cr , Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce, at least one selected from the group consisting of oxides, halides, and phosphates Obtained by dry blending a mixture comprising 0.01 part of iron oxide (C-1), 0.5 part of talc (G-1) and 0.25 part of barium stearate (G-2) as a metal compound The obtained mixture was fed at a rate of about 70 kg / hr to an extruder in which an extruder having a diameter of 65 mm and a diameter of 90 mm was vertically connected. The mixture supplied to the 65 mm diameter extruder is heated to 200 ° C. and kneaded, and the resin temperature is cooled to 120 ° C. with a 90 mm diameter extruder connected to the extruder, and is attached to the tip of the 90 mm diameter 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 32 kg / m ³ .
At this time, as the foaming agent, an extruder having a diameter of 65 mm was prepared such that the foaming agent composed of 67% isobutane (E-2) and 33% dimethyl ether (F-1) was 6 parts with respect to 100 parts of styrene resin. Was pressed into the resin from the vicinity of the tip (the end connected to the end opposite to the end of the extruder having a diameter of 90 mm).
The properties of the obtained extruded foam are shown in Table 2.

(Examples 7 to 12)
Halogen flame retardant (B), Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce oxide , At least one metal compound (C) selected from the group consisting of halides and phosphates, phosphorus-containing compounds, nitrogen-containing compounds, boron-containing compounds, sulfur-containing compounds (E), foaming agents (F), and other foams A foam was obtained in the same manner as in Example 6 except that the type and addition amount of the agent (G) were changed to the values shown in Table 2.
The properties of the obtained extruded foam are shown in Table 2.

(Comparative Example 2)
Table 2 shows types and addition amounts of the halogen-based flame retardant (B), phosphorus-containing compound, nitrogen-containing compound, boron-containing compound, sulfur-containing compound (D), foaming agent (E), and other foaming agent (F). A foam was obtained in the same manner as in Example 6 except that the values shown were used. The properties of the obtained extruded foam are shown in Table 2.

  As is apparent from a comparison of Examples 7 to 12, which are examples of the present invention, and Comparative Example 2, according to the present invention, the thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam ( A foam excellent in flame retardancy can be obtained by setting the temperature under a nitrogen stream (50 ml / min) at a heating rate of 10 ° C./min to 300 ° C. or less, and halogen in the styrene resin foam. It can be seen that a foam having excellent heat resistance and recyclability can be obtained by further limiting the thermal weight reduction start temperature of the flame retardant and the 5% thermal weight reduction temperature of the halogenated aliphatic group-containing compound. Further, it is clear that Example 6 to which no phosphorus-containing compound, nitrogen-containing compound and boron-containing compound were added was compared with Examples 7 to 12 to which a phosphorus-containing compound, nitrogen-containing compound or boron-containing compound was added. Further, it can be seen that by adding a phosphorus-containing compound, a nitrogen-containing compound or a boron-containing compound, combustion of the foaming agent is suppressed and flame retardancy is improved.

(Example 13)
100 parts of styrene resin (A-1), 5 parts of tetrabromobisphenol A-bis (2,3-dibromopropyl ether) (B-1) as a halogen flame retardant, Al, Ti, V, Cr, At least one metal selected from the group consisting of oxides, halides and phosphates of Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce 0.01 parts of iron oxide (C-1) as a compound, 1 part of triphenyl phosphate (D-1) as a phosphorus-containing compound, 2 parts of isocyanuric acid (D-2) as a nitrogen-containing compound, talc as other additives (G-1) 0.2 parts, barium stearate (G-2) 0.25 parts, bentonite (G-3) 1 part and AEROSIL (G-4) 0.01 part Blended, it was supplied at a rate of about 70 kg / hr into the extruder an extruder coupled to the vertical of the resulting mixture caliber 65mm and diameter 90 mm. The mixture supplied to the 65 mm diameter extruder is heated to 200 ° C. and kneaded, and the resin temperature is cooled to 120 ° C. with a 90 mm diameter extruder connected to the extruder, and is attached to the tip of the 90 mm diameter extruder. Extruded into the atmosphere from the provided rectangular cross-section die having a thickness direction of 2 mm and a width direction of 50 mm, a rectangular parallelepiped extruded foam was obtained.
At this time, 6.8 parts of a foaming agent composed of 59% isobutane (E-2), 29% dimethyl ether (F-1) and 12% water (F-2) as a foaming agent with respect to 100 parts of styrene resin. Then, it was 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 3.

(Examples 14 to 17)
Implemented except that the types and amounts of addition of the halogen-based flame retardant (B), phosphorus-containing compound, nitrogen-containing compound (D), blowing agent (E), and other blowing agent (F) were as shown in Table 3. A foam was obtained in the same manner as in Example 13.
The properties of the obtained extruded foam are shown in Table 3.

(Comparative Example 3)
Except that the halogen flame retardant (C), the phosphorus-containing compound, the nitrogen-containing compound (D), the foaming agent (E), and the other foaming agent (F) were changed to the values shown in Table 3, A foam was obtained in the same manner as in Example 13. The properties of the obtained extruded foam are shown in Table 3.

  As is apparent from comparison between Examples 13 to 17 which are examples of the present invention and Comparative Example 3, according to the present invention, the thermogravimetric reduction starting temperature of the halogen-based flame retardant in the styrene resin foam ( A foam excellent in flame retardancy can be obtained by setting the temperature under a nitrogen stream (50 ml / min) at a heating rate of 10 ° C./min to 300 ° C. or less, and halogen in the styrene resin foam. It can be seen that a foam having excellent heat resistance and recyclability can be obtained by further limiting the thermal weight reduction start temperature of the flame retardant and the 5% thermal weight reduction temperature of the halogenated aliphatic group-containing compound. Further, it is clear by comparing Example 8 in which water is not added as another blowing agent and Examples 13 to 17 in which water is used as another blowing agent and bentonite or AELOSIL is added as another additive. As described above, water is used as another foaming agent, and bentonite or AELOSIL is further added as another additive, whereby the foam cell structure of the foam has a relatively small bubble diameter of approximately 0.25 mm or less. A characteristic bubble structure in which bubbles (small bubbles) and bubbles with a relatively large bubble diameter (large bubbles) having a bubble diameter of approximately 0.3 mm to 1 mm are mixed in a sea-island shape. It can be seen that by using a cell structure with a rate of 35 to 40%, the thermal conductivity is also reduced and the heat insulation is further improved.

The measuring method of the thermal weight reduction start temperature of the halogenated flame retardant in the styrene resin foam in the present invention is shown. In the thermogravimetric decrease curve when the measurement sample weight is taken as 100% on the ordinate and the temperature is taken on the abscissa when measured with a thermogravimetric method using a thermogravimetric measuring device. The temperature of the intersection of the tangent before the start of weight reduction in the thermal weight loss curve confirmed to be derived from the flame retardant and the tangent of the portion with the largest slope of the weight reduction curve is determined as the halogen-based difficulty in the styrene resin foam. The thermal weight reduction start temperature of the fuel is used.

Claims (12)

  A styrene resin foam containing a halogen-based flame retardant, wherein a thermal weight reduction start temperature of the halogen-based flame retardant in the styrene resin foam (under a nitrogen stream (50 ml / min), a temperature increase rate of 10 ° C. / A styrenic resin foam characterized by having a temperature of 300 ° C. or less.   The styrene resin foam according to claim 1, wherein the styrene resin foam is formed by extrusion foaming.   3. The styrene resin foam according to claim 1, wherein the halogen-based flame retardant in the styrene resin foam has a thermogravimetric decrease starting temperature of 260 to 280 ° C. 3.   The styrenic resin foam according to any one of claims 1 to 3, wherein the halogen-based flame retardant is a halogenated aliphatic group-containing compound.   The 5% thermal weight loss temperature of the halogenated aliphatic group-containing compound (measured at a heating rate of 10 ° C./min under a nitrogen stream (50 ml / min)) is 250 ° C. or more. 4. The styrene resin foam according to 4.   6. The halogenated aliphatic group-containing compound is tris (2,3-dibromopropyl) isocyanurate and / or tetrabromobisphenol A bis (2,3-dibromopropyl ether). Styrene resin foam.   The foaming agent is selected from the group consisting of hydrocarbons and halogenated hydrocarbons, and at least one compound having an ozone depletion coefficient of 0 is used. Styrenic resin foam.   The thermal weight reduction start temperature of the halogenated flame retardant in the styrene resin foam is increased by the thermal weight reduction start temperature of the halogenated flame retardant alone (the halogenated flame retardant alone in a nitrogen stream (50 ml / min)). The styrenic resin foam according to any one of claims 1 to 7, wherein a decrease width with respect to a temperature rate of 10 ° C / min) is 5 ° C or more.   Consists of oxides, halides and phosphates of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ru, Pd, Ag, Sn, W, Os, Pt or Ce The styrenic resin foam according to any one of claims 1 to 8, comprising at least one metal compound selected from the group.   The styrenic resin foam according to claim 9, wherein the metal compound is iron oxide.   The styrenic system according to any one of claims 1 to 10, wherein the bubbles forming the foam are mainly composed of bubbles having a bubble diameter of 0.25 mm or less and bubbles having a bubble diameter of 0.3 to 1 mm. Resin foam.   The styrenic resin contains a styrenic resin composition obtained by regenerating the styrenic resin foam according to any one of claims 1 to 11. Styrene resin foam.

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