JP2009263442A - Thermoplastic resin foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thick thermoplastic resin foam excellent in heat resistance, chemical resistance, low moisture permeability, and environmental friendliness with material recyclability, and meeting fire retardance requirements for building material application, especially a thermoplastic resin foam meeting requirements on heat resistance and chemical resistance which cannot be attained with a polystyrene resin foam. <P>SOLUTION: A thermoplastic resin foam is produced by foaming a thermoplastic resin composition consisting of 0.04 wt.% and more to less than 30 wt.% of N-alkyl-substituted maleimide unit, 40 to 75 wt.% of aromatic vinyl unit, and 10 to 33 wt.% of vinyl cyanide unit, wherein the sum of these three units is 100 wt.% The thermoplastic resin foam contains 3 to 15 pts.wt. of a bromine-based fire retardant having 5 wt.% loss onset temperature during pyrolysis of 230°C or higher, and melting point or softening point of 150°C or higher based on 100 pts.wt. of the thermoplastic resin composition, and has foam thickness of 10 to 150 mm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin foam that is excellent in heat resistance, chemical resistance, and flame retardancy, and is also used for architectural heat insulating materials.

  Conventionally, styrene resin foams, cross-linked polyethylene foams, and rigid polyurethane foams have been widely used as heat insulating materials for buildings due to their suitability for construction and heat insulating properties.

  However, although the styrene resin foam is useful as a heat insulating material excellent in environmental compatibility in consideration of material recycling, since the heat resistant temperature of styrene as a base resin is around 80 ° C., a higher temperature range than that. In applications exposed to water (for example, panel curing materials for steam curing chambers, drying curing chambers, etc.), it has a problem that it cannot be used to cause deformation of the foam so that the shape cannot be maintained. .

  In addition, since the styrene resin foam has low chemical resistance, it is contained in the adhesive when, for example, a heat insulating material and a waterproof sheet such as a sheet waterproof bonding method in a roof heat insulating waterproof field are bonded with an adhesive. It was not resistant to the plasticizer contained in the solvent and the waterproof sheet, and the foam was dissolved and disintegrated and had a problem that it could not be used because the foam could be deformed so that the shape could not be retained. .

  On the other hand, since the crosslinked polyethylene foam has high chemical resistance, it is preferably used as a heat insulating material for the sheet waterproof bonding method in the roof thermal insulation waterproof field, but the heat resistance is about the same as the styrene resin foam. Therefore, it has a problem that it cannot be used for applications exposed to a high temperature range of 80 ° C. or higher. In addition, since cross-linked polyethylene has a cross-linked structure, it is difficult to say that it is poor in material recyclability and excellent in environmental compatibility.

  Further, it is generally known that the hard polyurethane foam has high chemical resistance like the above-mentioned crosslinked polyethylene foam, and further, since the hard polyurethane is a thermosetting resin, it has high heat resistance. However, the rigid polyurethane foam has a problem that it cannot be used for, for example, a heat-insulating panel of a steam curing room because the heat-absorbing property is extremely deteriorated when the moisture absorption state is high. It was. In addition, since hard polyurethane is a thermosetting resin, it is difficult to say that it is poor in material recyclability and excellent in environmental compatibility.

  Each of the three types of foams has advantages and disadvantages, and it is difficult to have both characteristics.

  On the other hand, some examples of the heat resistance improvement of the styrene resin foam excellent in environmental compatibility like material recyclability and having improved heat resistance are disclosed.

  For example, efforts have been made on a heat-resistant styrene resin extruded foam plate obtained by extrusion foaming a styrene-α-methylstyrene-acrylonitrile copolymer (see Patent Document 1). In this approach, by using a styrene-α-methylstyrene-acrylonitrile copolymer, the heat distortion temperature becomes 92 ° C. or higher and 110 ° C. or lower, and heat resistance is improved as compared with conventional styrene resin foams. Is recognized. However, since the main component is made of styrene, there is a limit to chemical resistance, and when a sheet waterproof adhesive is applied in the roof thermal insulation waterproof field, the foam dissolves and collapses due to the influence of the solvent contained in the adhesive. However, it cannot be used to cause deformation of the foam such that the shape cannot be maintained.

  In addition, efforts have been made to improve heat resistance by incorporating a maleimide compound into a styrene resin or bonding at a molecular level (see Patent Documents 2 to 4). In the field of injection molding, heat resistance has been improved by introducing a maleimide compound into a styrene resin, and it has been used mainly in the automotive field as a heat resistance improver for ABS resins.

  However, a resin composition in which a maleimide compound is introduced into a styrene resin has improved heat resistance, but tends to decrease fluidity and elongation in a molten state. When a foam is obtained from the resin composition, the flowability and elongation of the molten resin composition containing the foaming agent are reduced. Even if it is going to form the foam attached using a type | mold, a cell film is hard to expand | extend and the tendency for the surface property at the time of shaping | molding to deteriorate becomes large. Furthermore, if the molding die is cooled too much as in the method for producing a styrene resin foam, the temperature difference between the surface layer of the cooled foam and the inner layer at which cell flow occurs is increased. For this reason, the foam has a problem that a crack occurs from the inside toward the surface, and the foam cannot be formed into a plate shape.

  Moreover, the approach which makes a maleimide-type compound flame-retardant is made | formed (refer patent documents 5-7). In this approach, a resin composition using a maleimide compound is used, particularly for the purpose of imparting flame retardancy in an injection-molded product. However, in this approach, nothing is described regarding a plate-like foam. In particular, in the case of a foam, the heat transfer rate after the flame is ignited is significantly faster than that of an injection-molded body. In addition, when the foaming agent remaining in the foam is a combustible gas, Since it is necessary to suppress the ignition or combustion of flammable gas from the foam, it is particularly required for the flame resistance required for building materials, specifically the conditions specified in JIS A9511 or specified by the Fire Service Act It was very difficult to meet the oxygen index.

  Therefore, it is very difficult to make full use of a resin composition using a maleimide compound, to produce a thick plate-like foamed molded article, and to achieve a quality that matches the flame retardancy required for building materials. Met.

Because of these, it has the advantages of styrene resin foam, cross-linked polyethylene foam, and rigid polyurethane foam, and is excellent in heat resistance, chemical resistance, moldability, low moisture permeability, and environmental compatibility that enables material recycling. The development of a thick thermoplastic resin foam that meets the flame resistance required for building material applications is also awaited.
JP-A-60-199624 JP-A-61-78846 Japanese Patent Laid-Open No. 2-184418 Japanese Patent Laid-Open No. 4-25532 Japanese Patent Laid-Open No. 7-53833 JP-A-10-168261 JP-A-10-182905

  The object of the present invention is excellent in heat resistance, chemical resistance, and low moisture permeability, excellent in environmental friendliness that can be recycled, and in conformity with flame retardancy required for building materials. The object is to provide a thermoplastic resin foam.

  As a result of earnest research in view of the conventional technology, the present inventors have obtained a copolymer imparted with heat resistance, chemical resistance, and low moisture permeability from the viewpoint of heat resistance, chemical resistance, and low moisture permeability, and From the viewpoint of chemical resistance, fluidity, and low moisture permeability, a specific brominated flame retardant and further a thermoplastic resin composition containing a copolymer imparted with chemical resistance, fluidity, and low moisture permeability. Accordingly, the present inventors have found that a foam containing an antimony compound as a flame retardant aid satisfies the above object, and has completed the present invention.

  That is, the present invention comprises [1] N-alkyl-substituted maleimide units of 0.04 wt% or more and less than 30 wt%, aromatic vinyl units 40 to 75 wt% and vinyl cyanide units 10 to 33 wt% (3 units Is a thermoplastic resin foam obtained by foaming a thermoplastic resin composition, the 5% thermal weight reduction start temperature is 230 ° C. or more with respect to 100 parts by weight of the thermoplastic resin composition, and It comprises 3 to 15 parts by weight of at least one flame retardant selected from brominated flame retardants having a melting point or softening point of 150 ° C. or more, and the foam has a thickness of 10 to 150 mm. And relates to a thermoplastic resin foam.

  Furthermore, the present invention relates to [2] the thermoplastic resin foam according to [1], wherein the aromatic vinyl unit is a styrene unit.

  Furthermore, the present invention relates to the thermoplastic resin foam according to the above [1] or [2], wherein the [3] N-alkyl-substituted maleimide unit is an N-phenylmaleimide unit.

  Furthermore, the present invention relates to the thermoplastic resin foam according to any one of [1] to [3], wherein the [4] vinyl cyanide unit is acrylonitrile.

Furthermore, the present invention provides the thermoplastic resin according to any one of [1] to [4], wherein [5] the moisture permeability coefficient of the foam is 160 ng / m ² · s · Pa or less. Relates to foam.

  Further, the present invention provides [6] a brominated flame retardant having a 5% thermogravimetric decrease starting temperature of 230 ° C. or higher and a melting point or softening point of 150 ° C. or higher is tetrabromobisphenol A, hexabromocyclododecane, decabromo. Diphenyl ether, ethylene bis (pentabromophenyl), bis (2,4,6-tribromophenoxy) ethane, tetrabromobisphenol A diglycidyl ether copolymer, tribromophenol adduct of tetrabromobisphenol A diglycidyl ether copolymer, 2, Any one of [1] to [5] above, which is 4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine or tris (tribromoneopentyl) phosphate The thermoplastic resin foam described in 1.

  Further, the present invention [7] further includes 0.1 to 5 parts by weight of an antimony compound as a flame retardant aid with respect to 100 parts by weight of the thermoplastic resin composition. It is related with the thermoplastic resin foam in any one of-[6].

  Furthermore, the present invention relates to the thermoplastic resin foam according to any one of [1] to [7], wherein the [8] antimony compound is antimony trioxide.

  According to the present invention, a thick-walled thermoplastic resin that has excellent heat resistance, chemical resistance, low moisture permeability, environmental compatibility that enables material recycling, and further meets the flame retardancy required for building materials. A foam is obtained.

  In particular, it is possible to obtain a thermoplastic resin foam that satisfies the required qualities of heat resistance and chemical resistance that cannot be satisfied by a styrene resin foam alone.

  More specifically, it has long-term heat resistance in which the volume change rate of the foam after exposure for 24 hours is 3% or less in an oven at 100 ° C., and is applied to a sheet waterproof bonding method in the roof thermal insulation waterproof field. A thermoplastic resin foam that does not cause shape deformation such as dissolution and collapse of the foam can be obtained even when the adhesive and the plasticizer contained in the waterproof sheet are used.

  Hereinafter, the present invention will be described in detail.

  The thermoplastic resin composition in the present invention is a thermoplastic resin composition comprising an N-alkyl-substituted maleimide unit, an aromatic vinyl unit and a vinyl cyanide unit. Examples of the aromatic vinyl unit include styrene, α-methylstyrene, ethylstyrene, isopropylstyrene, dimethylstyrene, bromostyrene, chlorostyrene, vinyltoluene, and vinylxylene. Of these, styrene and α-methylstyrene are preferable from the viewpoint of ease of polymerization, and styrene which is inexpensive in price is most preferable. Examples of N-alkyl-substituted maleimide units include N-methylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-4-diphenylmaleimide, N-2-chlorophenylmaleimide, and N-4-bromo. Examples thereof include phenylmaleimide and N-1-naphthylmaleimide, and N-phenylmaleimide is optimal from the viewpoint of ease of polymerization and low cost. Furthermore, examples of the vinyl cyanide unit include acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, and acrylonitrile is preferred from the viewpoint of ease of polymerization and low cost.

  The composition ratio of the N-alkyl-substituted maleimide unit, aromatic vinyl unit and vinyl cyanide unit constituting the resin composition in the present invention is 0.04% by weight of N-alkyl-substituted maleimide unit when the total is 100% by weight. It is preferably comprised of less than 30% by weight, aromatic vinyl units of 40 to 75% by weight and vinyl cyanide units of 10 to 33% by weight. By setting the composition ratio of the N-alkyl-substituted maleimide unit in the above range, both the 100 ° C. heat resistance and chemical resistance aimed by the present invention can be achieved, and a more preferable range is 10 wt% or more and less than 30 wt%. is there. By making the composition ratio of the aromatic vinyl unit within the above range, it is easy to obtain the fluidity necessary for molding stability while maintaining the heat resistance of the present invention, and by providing an upper limit value for the aromatic vinyl unit, the chemical resistance As a more preferable range, it is 50 to 70% by weight. By keeping the composition ratio of the vinyl cyanide unit within the above range, while maintaining the heat resistance of the present invention, in addition, it becomes easy to obtain molding stability similarly to the polystyrene extruded foam plate, and the moisture permeability is low. Deterioration of physical properties due to moisture absorption / water absorption in the living environment can be reduced. Furthermore, chemical resistance can be expressed by providing a lower limit for the vinyl cyanide unit, and a more preferable range is 10 to 28% by weight.

  If the thermoplastic resin composition comprising the N-alkyl-substituted maleimide unit, aromatic vinyl unit and vinyl cyanide unit in the present invention satisfies the above composition ratio, the N-alkyl-substituted maleimide unit, aromatic vinyl unit and cyanide will be used. The copolymer (A) consisting of vinyl halide units may be used alone, or the copolymer (B) consisting of aromatic vinyl units and vinyl cyanide units may be used relative to the copolymer (A). You may use it in combination.

  In addition, as an aromatic vinyl unit in the copolymer (B) of the present invention, as described above, styrene and α-methylstyrene are preferable from the viewpoint of compatibility with the copolymer (A) and ease of polymerization. Styrene is preferred because it is suitable and inexpensive. Examples of the vinyl cyanide unit include acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, and acrylonitrile is preferred from the viewpoint of compatibility with the copolymer (A) and ease of polymerization. In view of compatibility with the copolymer (A), ease of polymerization, and low cost, the copolymer (B) in the present invention is preferably a copolymer of styrene and acrylonitrile.

  As a foaming agent for obtaining the thermoplastic resin foam of the present invention, a foaming agent containing no chlorine atom can be used for the thermoplastic resin composition comprising the above structural units. Moreover, as such a foaming agent, 1 type chosen from the group which consists of a physical type foaming agent and a chemical type foaming agent can be used, or 2 or more types can be mixed and used. By not containing a chlorine atom, it is preferable because the burden on the environment is reduced. However, in order to achieve the object of the present invention, it is not always necessary to contain no chlorine atom.

  Specific examples of the physical foaming agent include hydrocarbons such as propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, cyclopentane, hexane, and cyclohexane; 1,1-difluoroethane, 1 , 2-difluoroethane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, , 1,1,2,2-pentafluoroethane, difluoromethane, trifluoromethane and other fluorinated hydrocarbons; carbon dioxide, nitrogen, water, argon, helium and other inorganic gases; dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl Ether, n-butyl ether, diisoamyl ether, furan, furfural, 2-methyl Ethers such as furan, tetrahydrofuran and tetrahydropyran; alkyl chlorides such as methyl chloride, ethyl chloride, propyl chloride and isopropyl chloride; methyl formate, ethyl formate, propyl formate, butyl formate, amyl formate, propionic acid Carboxylic acid esters such as methyl ester and propionic acid ethyl ester; alcohols such as methanol, ethanol, propyl alcohol, i-propyl alcohol, butyl alcohol, i-butyl alcohol and t-butyl alcohol, dimethyl ketone, methyl ethyl ketone and diethyl ketone Methyl-n-propyl ketone, methyl-n-butyl ketone, methyl-i-butyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, ethyl-n-propyl Piruketon, ketones such as ethyl -n- butyl ketone, and the like. These can be used alone or in admixture of two or more.

  Specific examples of the chemical foaming agent include, for example, N, N′-dinitrosopentamethylenetetramine, p, p′-oxybis-benzenesulfonylhydrazide, hydrazodicarbonamide, sodium carbonate, azodicarbonamide, terephthalazide, 5 -Phenyltetrazole, p-toluenesulfonyl semicarbazide and the like. These can be used alone or in admixture of two or more.

  Among the above-mentioned blowing agents, from the viewpoint of protecting the ozone layer, hydrocarbons such as propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, cyclopentane, hexane, cyclohexane, carbon dioxide, Inorganic gases such as nitrogen, water, argon, helium, ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, n-butyl ether, diisoamyl ether, methanol, ethanol, propyl alcohol, i-propyl alcohol, butyl Alcohols such as alcohol, i-butyl alcohol and t-butyl alcohol are preferred.

  Of the foaming agents described above, the foaming agent is mainly selected from the group consisting of (a) ethers and alkyl chlorides in consideration of weight reduction of the foam and stability of extrusion foaming. In addition, one containing 0.5 to 10 parts by weight of one or more and (b) 0 to 6 parts by weight of hydrocarbon is preferable.

  Examples of the ether in the foaming agent of the present invention include the ethers described above, and among these, dimethyl ether reduces the extrusion pressure during extrusion foaming, and can stably produce an extruded foam. preferable. The amount of ether used is preferably 0.5 to 10 parts by weight, more preferably 1.5 to 6 parts by weight, and more preferably 3 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition. Part is particularly preferred. When the amount of ether used is in the range of 0.5 to 10 parts by weight, the foamability and gas dispersibility in the foam are good, and the foamability is good.

  Examples of the alkyl chloride in the foaming agent of the present invention include the above-mentioned alkyl chlorides. Among these, methyl chloride and ethyl chloride reduce the extrusion pressure during extrusion foaming, and the extruded foam can be stably formed. It is preferable at the point manufactured. The amount of alkyl chloride used is preferably 0.5 to 10 parts by weight, more preferably 1.5 to 6 parts by weight, and more preferably 3 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition. Part by weight is particularly preferred. When the amount of alkyl chloride used is in the range of 0.5 to 10 parts by weight, the foamability and gas dispersibility in the foam are good, and the foamability is good.

  Examples of the hydrocarbon in the foaming agent of the present invention include the hydrocarbons described above, but if the boiling point is too low, the vapor pressure becomes high, and a high pressure is required for handling, which tends to be a problem in production. If the boiling point is too high, the foaming agent remains as a liquid in the foam bubbles and tends to lower the heat resistant temperature of the foam. Therefore, a saturated hydrocarbon having a boiling point in the range of −50 ° C. to 85 ° C. is preferable. Examples of the saturated hydrocarbon having a boiling point in the range of −50 ° C. to 85 ° C. include propane, cyclopropane, n-butane, i-butane, cyclobutane, n-pentane, i-pentane, neopentane, cyclopentane, hexane, Examples include 2-methylpentane, 3-methylpentane, 1,2-dimethylbutane, cyclohexane and the like. Of these, propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, cyclopentane, n-hexane and cyclohexane are preferred from the viewpoint of production stability. The amount of hydrocarbon used is preferably 0 to 6 parts by weight and more preferably 2 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin composition. When the amount of hydrocarbon used is in the range of 0 to 6 parts by weight, gas dispersibility in the foam is good and foamability is good.

  The brominated flame retardant used in the present invention preferably has a 5% thermogravimetric decrease starting temperature of 230 ° C or higher and a melting point or softening point of 150 ° C or higher.

  The 5% thermal weight loss starting temperature of the brominated flame retardant is more preferably 235 ° C. or higher, and further preferably 240 ° C. or higher. If the 5% thermal weight reduction start temperature of the brominated flame retardant is in the range of 230 ° C or higher, the thermal stability is reduced due to the decomposition of the flame retardant in the extruder, and the heat resistance of the obtained foam is reduced. It is preferable because it does not have an adverse effect. On the other hand, for the expression of flame retardancy, the bromine-based flame retardant preferably has a 5% thermogravimetric decrease starting temperature of 400 ° C. or lower.

  Moreover, as melting | fusing point or softening point of a brominated flame retardant, 160 degreeC or more is more preferable, and 170 degreeC or more is further more preferable. If the melting point or softening point of the brominated flame retardant is in the range of 150 ° C. or higher, there will be no adverse effects such as instability of extrusion due to melting or softening of the brominated flame retardant, and reduced heat resistance of the obtained foam. ,preferable.

  In addition, the softening point of the brominated flame retardant in the present invention is a value measured according to JIS K7234 (Method for testing softening point of epoxy resin).

  For brominated flame retardants that do not have a clear melting point for epoxy flame retardants such as tetrabromobisphenol A diglycidyl ether copolymer and tribromophenol adducts of tetrabromobisphenol A diglycidyl ether copolymer, solid materials are softened. A softening point was substituted.

  Examples of the brominated flame retardant having a 5% thermogravimetric decrease starting temperature of 230 ° C. or higher and a melting point or softening point of 150 ° C. or higher used in the present invention include hexabromocyclododecane, hexabromobenzene, pentabromotoluene, Ethylene bis (pentabromophenyl), decabromodiphenyl ether, bis (2,4,6-tribromophenoxy) ethane, pentabromobenzyl acrylate polymer, tetrabromobisphenol A, tetrabromobisphenol A diglycidyl ether copolymer, tetrabromobisphenol A Tribromophenol adduct of diglycidyl ether copolymer, tetrabromobisphenol S, tetrabromobisphenol A polycarbonate oligomer, ethylenebistetrabromophthalimide, 2, 4, - tris (2,4,6-tribromophenoxy) 1,3,5-triazine, and tris (tribromoneopentyl) phosphate can be mentioned.

  Among the brominated flame retardants, tetrabromobisphenol A, hexabromocyclododecane, good dispersibility with the thermoplastic resin composition, less adverse effects on heat resistance, and high flame retardant effect, Decabromodiphenyl ether, ethylenebis (pentabromophenyl), bis (2,4,6-tribromophenoxy) ethane, tetrabromobisphenol A diglycidyl ether copolymer, tribromophenol adduct of tetrabromobisphenol A diglycidyl ether copolymer, 2,4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine, tris (tribromoneopentyl) phosphate is preferred.

  The content of the brominated flame retardant in the present invention is appropriately adjusted so that the flame retardancy specified in JIS A9511 is satisfied and the oxygen index of the foam is 26% or more. The range of 3 to 15 parts by weight is preferable with respect to 100 parts by weight of the mixture, more preferably 4 to 13 parts by weight, and still more preferably 5 to 10 parts by weight.

  If the content of brominated flame retardant is within the above range, physical properties such as thermal stability and heat resistance may be reduced, and extrusion stability and foam moldability may be reduced. The present invention is preferable because it satisfies the intended flame retardancy.

  The JIS A9511 corresponds to the Japanese Industrial Standard applied to the foamed plastic heat insulating material. The flammability specified in JIS A9511 includes three measurement methods A to C. In this test, among the foamed plastic heat insulating materials, bead method polystyrene foam heat insulating material, extrusion method polystyrene foam heat insulating material. It conformed to measurement method A applied to.

  The measurement method is as follows. A flame of the candle for the fire source is moved horizontally to the ignition limit indicating line at a constant speed over about 5 seconds on a test piece (thickness 10 mm, length 200 mm, width 25 mm) inclined at 45 °. After reaching the ignition limit indicator line, the flame is quickly retracted, and the time from the moment until the flame disappears and the combustion stop position are confirmed.

  The flame retardant judgment criteria are as follows: (1) The average of the flame extinguishing time of five test specimens is within 3 seconds, (2) no residual dust, (3) each specimen has a combustion limit indicating line It is demanded that combustion does not exceed (20 mm from the ignition limit indication line).

  In the present invention, if necessary, an antimony compound as a flame retardant aid is used in combination with the brominated flame retardant, so that the amount of brominated flame retardant used can be reduced and the heat history in the extruder can be reduced. The accompanying resin deterioration can be suppressed.

  Examples of the antimony compound used in the present invention include antimony trioxide, antimony tetraoxide, antimony pentoxide, sodium antimonate, and antimony phosphate. With respect to flame retardancy, antimony trioxide is preferred because of its high synergistic effect with the brominated flame retardant.

  The content of the antimony compound in the present invention is appropriately adjusted so that the flame retardancy specified in JIS A9511 is satisfied and the oxygen index of the foam is 26% or more, but generally the thermoplastic resin composition. The range of 0.1 to 5 parts by weight is preferable with respect to 100 parts by weight, more preferably 0.5 to 4.5 parts by weight, and still more preferably 1 to 4 parts by weight.

  If the content of the antimony compound is within the above range, the brominated flame retardant can be used without causing problems such as a decrease in physical stability, a decrease in heat resistance, a decrease in extrusion stability, and a decrease in foam moldability. This is preferable because the synergistic effect is effectively expressed and the flame retardancy aimed by the present invention is satisfied.

  In the present invention, the resin composition, if necessary, as various additives within a range that assumes the effects of the present invention, a nucleating agent, a stabilizer, a lubricant, an antistatic agent, a plasticizer, a water absorbing agent. You may mix | blend additives, such as an agent and a radiation inhibitor.

  Since the thermoplastic resin foam of the present invention is characterized by being a plate-like foam, the thickness of the thermoplastic resin foam of the present invention is preferably 10 to 150 mm, more preferably 20 to 100 mm. For example, in the case of a heat insulating material used for applications such as building materials, in order to give preferable heat insulating properties, it tends to be difficult to obtain with a sheet-like foam having a thickness of less than 10 mm. Even if the thickness of the foam exceeds 150 mm, it is possible to manufacture on a small scale such as an experimental machine, but because the thickness increases, the temperature difference between the foam surface layer and the inner layer is added, so the internal The closed cell ratio tends to decrease due to the effect of heat storage, and as a result, the heat insulating properties, dimensional stability, strength, and the like may decrease.

Density of the thermoplastic resin foam in the present invention is preferably in the range of 20 and 100 kg / ^{m 3,} and more preferably in the range of 25~50kg / ^{m 3.} If the foam density is in the above range, it is preferable from the viewpoint of expression of surface compressive strength represented by plane compressive strength.

  Examples of the cell structure forming the thermoplastic resin foam of the present invention include a uniform cell structure and a composite cell structure in which large and small cells are mixed, but the cell structure is not particularly limited.

  The average diameter of the bubbles in the thermoplastic resin foam of the present invention is preferably preferably from 0.05 to 2.0 mm, more preferably from 0.1 to 1.0 mm. The bubble diameter is measured, for example, according to ASTM D-3576 from a photograph obtained by sampling a part of the cross-section of the extruded foam and magnifying it with a scanning electron microscope. be able to. All of the bubble diameters are not necessarily in the above range, and at least the average value of the bubble diameters may be in the above range. When the average diameter of the bubbles is less than 0.05 mm, the moldability is greatly lowered, and stable production tends to be difficult. Moreover, when an average diameter exceeds 2.0 mm, there exists a tendency for the external appearance of the product surface to deteriorate.

Permeance of the thermoplastic resin foam in the present invention is preferably not more than ^{160ng / m 2 · s · Pa} , more preferably at most ^{145ng / m 2 · s · Pa} . When the permeability coefficient exceeds 160 ng / m ² · s · Pa, heat resistance and heat insulation tend to deteriorate.

  The thermoplastic resin foam of the present invention can be obtained by a known method using the resin composition. For example, the thermoplastic resin composition is supplied to a known heat-melting and kneading apparatus such as an extruder and heated and melted to add a foaming agent under a high-pressure condition, and form a foamable gel substance. A step, a step of cooling the gel-like substance, a step of extruding and foaming the gel-like substance from a high-pressure region to a low-pressure region through a die such as a slit die, and a molding die placed in close contact with or in contact with the die. A thick-walled plate-like thermoplastic resin foam can be obtained through a step of forming a foam to be shaped by using.

  Prior to adding the blowing agent, the resin composition is heated to its glass transition temperature or melting point or higher. The foaming agent may be added by a method that can disperse in the heat-melted resin. That is, the melted resin composition can be mixed, press-fitted or compounded by means known in the field related to the production and / or development of foams, for example, an extruder, a mixer and the like. Moreover, each foaming agent component can be put into an extruder individually or simultaneously. Furthermore, each foam component may be blended in either a liquid or gas state.

  As a procedure for adding various additives such as flame retardant to the thermoplastic resin composition, for example, (1) After adding and mixing various additives such as flame retardant to the thermoplastic resin composition, an extruder (2) Supplying the thermoplastic resin composition to a melt-kneading apparatus such as an extruder, heating and melting, and then heating and melting. Procedures for adding and mixing various additives such as flame retardant, and further adding and mixing foaming agent, (3) Melting and kneading by adding various additives such as flame retardant to the thermoplastic resin composition in advance The resin composition thus obtained is supplied again to the extruder and melted by heating, and then a procedure for adding and mixing a foaming agent is included. Various additives are added to the thermoplastic resin composition. The timing is not particularly limited.

  In the production of the thermoplastic resin foam of the present invention, the heating temperature, melt kneading time and melt kneading when the thermoplastic resin composition, the foaming agent, and various additives added as necessary are heated and kneaded. The means is not particularly limited.

  The heating temperature may be equal to or higher than the temperature at which the thermoplastic resin composition melts (glass transition temperature or melting point), but is preferably a temperature at which decomposition / degradation of the resin due to the influence of a flame retardant is suppressed as much as possible.

  The melt-kneading time varies depending on the amount of extrusion per unit time, the type of melt-kneading equipment, etc., and thus cannot be determined unconditionally. However, the thermoplastic resin composition and the foaming agent or additive are uniformly dispersed and mixed. It is appropriately set as the time required for.

  Examples of the melt-kneading means include a screw type extruder such as a single screw or a twin screw, but there is no particular limitation as long as it is used for normal extrusion foaming. However, when the dispersibility of the foam is required, the extruder is preferably a twin screw type. In order to suppress degradation and degradation of the resin as much as possible, the screw shape of the extruder is preferably a low shear type.

  As the extrusion conditions in the present invention, it is preferable to maintain the internal pressure of the extrusion system at a high pressure so that the foaming agent does not vaporize in the extruder or the mold and is sufficiently dissolved in the resin.

  As one means thereof, the pressure in the slit die (hereinafter sometimes referred to as “slit pressure”) is preferably 3 MPa or more, and more preferably 4 MPa or more. It is preferable that the pressure in the slit die be 3 MPa or more because phenomena such as gas blowing, void generation in the foam, pressure fluctuation in the extruder system, and accompanying foam cross-sectional profile fluctuation are less likely to occur.

  The resin temperature of the gel substance at the exit of the step of cooling the gel substance is preferably 20 to 70 ° C. higher than the glass transition temperature of the thermoplastic resin composition. It is more preferable that the temperature is higher by 30 to 60 ° C. By setting the resin temperature at the process outlet to cool the gel-like substance to a temperature suitable for foaming within the above range, the gel substance is introduced into the die in a state where there is almost no increase in the slit pressure of the die and temperature unevenness. And good extrusion moldability and surface properties can be obtained.

  The set temperature of the die is preferably controlled to a temperature 5 to 50 ° C. lower than the resin temperature, and more preferably 10 to 40 ° C. lower. By setting the die set temperature within the above range, it is possible to maintain a die slit pressure and obtain a foam having good surface properties.

  The foam molding method is not particularly limited, and can be obtained, for example, by releasing pressure from the high pressure region to the low pressure region through a die such as a slit die having a slit shape used for extrusion molding. The extrusion foaming method of forming a thermoplastic resin extruded foam using a molding die installed in close contact with or in contact with the slit die and a molding roll installed adjacent to the downstream side of the molding die. For example, it is possible to obtain a plate-like foam that is thick and has a large cross-sectional area.

  The shape of the slit die includes a rectangular shape, a coat hanger shape, a fish tail shape, a tee shape, etc. When a wide plate-like foam is to be obtained, a coat hanger shape, a fish tail shape, a tee shape is used. A slit-shaped die is preferred.

  Furthermore, when trying to obtain a plate-like foam having a thickness of 10 to 150 mm, from the viewpoint of suppressing the dimension enlargement ratio in the thickness direction and the dimension enlargement ratio in the width direction of the molding die shape with respect to the slit die exit shape. A method of forming a desired foam width by using a slit die whose slit die outlet is enlarged in a flat plate shape is advantageous. In particular, since the thermoplastic resin composition in the present invention tends to be brittle with respect to the polystyrene-based resin, it is preferable to select a molding method that suppresses the expansion rate in the width direction as much as possible.

  In addition, when the resin composition is used, since the elongation of a resin such as a polystyrene resin cannot be expected from its resin characteristics, the surface of the extruded foam and molding are required to ensure the surface properties of the obtained extruded foam. It is important to reduce the resistance to the mold.

  Means for reducing the resistance between the extruded foam and the molding die include, for example, (1) heating the molding die by using steam, oil, an electric heater, etc., (2) polytetrafluoroethylene resin, etc. It is conceivable to install a material having a low surface resistance such as a sheet made of a fluororesin at the interface between the extruded foam surface and the molding die.

  Furthermore, it is important to gradually cool the foam obtained by extrusion foaming from the slit die in order to ensure the surface properties and physical properties of the obtained thermoplastic resin foam. That is, even when the surface of the foam is cooled and solidified, in the state where the inside of the foam is still fluid and has a foaming force, the surface portion cannot withstand the foaming force inside, The surface of the foam may cause defects such as cracks. In addition, as described above, the closed cell ratio of the obtained foam tends to decrease, and as a result, the heat insulating properties, dimensional stability, strength, and the like may decrease. Slow cooling conditions are also affected by the resin temperature at the time of foaming and may be adjusted as appropriate.However, depending on the length of the molding die, the heating temperature for the molding die, the installation distance of the material with low surface resistance, etc. Can be adjusted.

  The thermoplastic resin foam of the present invention is superior in heat resistance and chemical resistance as compared with conventional styrene-based extruded foams, for example, as a heat insulating material in the field of rooftop insulation and waterproofing, or in comparison with ordinary building material applications, It is suitably used for panel heat insulating materials such as a steam curing room and a drying curing room that are exposed to a higher temperature range.

  Hereinafter, the resin foam having both heat resistance and thermoplasticity according to the present invention will be described in detail by way of specific examples, but the present invention is not limited to such examples. Unless otherwise specified, “part” represents “part by weight” and “%” represents “% by weight”.

The copolymer and brominated flame retardant used in this example are as follows.
Copolymer (A): manufactured by Nippon Shokubai Co., Ltd., Polyimilex PAS1460
Copolymer (B): Toyo AS Co., Ltd., Toyo AS
PS resin: polystyrene resin (manufactured by PS Japan Co., Ltd., trade name: G9401, MFR at 200 ° C. × 5 kg = 0.2 g / min)
Brominated flame retardant (1): Decabromodiphenyl ether (manufactured by Albemarle, SAYTEX102E, 5% thermogravimetric decrease starting temperature: 326 ° C., melting point: 304 ° C.)
Brominated flame retardant (2): Ethylene bis (pentabromophenyl) (Albemarle, SAYTEX 8010, 5% thermogravimetric decrease starting temperature: 344 ° C., melting point: 350 ° C.)
Brominated flame retardant (3): bis (2,4,6-tribromophenoxy) ethane (manufactured by Great Lakes, FF680, 5% thermogravimetric decrease starting temperature: 276 ° C., melting point: 225 ° C.)
Brominated flame retardant (4): tetrabromobisphenol A diglycidyl ether copolymer (manufactured by Sakamoto Yakuhin Kogyo, SR-T5000, 5% thermogravimetric decrease starting temperature: 360 ° C., softening point: 190 ° C.)
Brominated flame retardant (5): tribromophenol adduct of tetrabromobisphenol A diglycidyl ether copolymer (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., SR-T3040, 5% thermogravimetric decrease starting temperature: 360 ° C., softening point: 170 ° C.)
Brominated flame retardant (6): 2,4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine (manufactured by ICL industrial, FR-245, 5% thermogravimetric decrease starting temperature: 385 ° C. , Melting point: 230 ° C.)
Brominated flame retardant (7): Tris (tribromoneopentyl) phosphate (manufactured by Daihachi Chemical Industry, CR900, 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.)
Brominated flame retardant (8): Tetrabromobisphenol A bis (2.3-dibromopropyl ether) (Albemarle, SAYTEX HP800A, 5% thermogravimetric decrease starting temperature: 312 ° C, melting point: 110 ° C)
Brominated flame retardant (9): Tetrabromocyclooctane (manufactured by Albemarle, SAYTEX BC48, 5% thermogravimetric decrease starting temperature: 167 ° C., melting point: 103 ° C.)

  About the characteristic of the foam obtained in Examples 1-21, Reference Examples 1-4, and Comparative Examples 1-5 shown below, foam density, average cell diameter, JIS A9511 flammability, foam oxygen index, 100 The heat resistance at 0 ° C., adhesive resistance, plasticizer resistance, moisture permeability, and surface properties were measured according to the following methods.

(1) Foam density (kg / m ³ )
The foam density was determined based on the following formula, and the unit was shown in terms of kg / m ³ .
Foam density (g / cm ³ ) = foam weight (g) / foam volume (cm ³ )

(2) Average cell diameter (mm)
The cell diameter in each of the extrusion direction, the width direction, and the thickness direction of the obtained foam was measured according to ASTM D-3576.
That is, the cross-section in the width direction of the foam is magnified and projected 50 to 100 times, and the cell diameter (HD) in the thickness direction and the cell diameter (TD) in the width direction are measured. Next, the cross section in the extrusion direction was enlarged and projected, and the cell diameter (MD) in the extrusion direction was measured.
The average cell diameter was calculated from the following formula by taking the cube of the product of the cell diameters in each direction.
Average cell diameter = (HD x TD x MD) ^1/3

(3) JIS A9511 flammability For the foams that had passed 7 days after production, according to JIS A9511, a test piece having a thickness of 10 mm, a length of 200 mm, and a width of 25 mm was used, and a combustion test was performed with an n number of 5, and the following criteria Judged by.
<Burning time>
A: All five flame extinguishing times are within 3 seconds.
○: Among 5 flame extinguishing times, at least one exceeds 3 seconds, but the average flame extinguishing time of 5 falls within 3 seconds.
X: The average flame-out time of five exceeds 3 seconds.
<Combustion status>
A: Combustion stops within the combustion limit indication line, and no foaming agent combustion is observed.
○: Combustion stops within the combustion limit indication line, but some of the foaming agent is observed.
X: Combustion continues beyond the combustion limit indicating line.

(4) Foam Oxygen Index The foam after 7 days from the production was measured according to JIS K7201 using a test piece having a thickness of 10 mm, a length of 150 mm and a width of 10 mm.

(5) 100 ° C. heat resistance (volume change rate of foam)
After creating the foam, it was conditioned for 10 days in a constant temperature room at 23 ° C. and 55% humidity, then cut into a thickness of 25 mm × length of 100 mm × width of 100 mm and heated in a hot air dryer set at 100 ° C. ± 2 ° C. for 24 hours. The volume change rate (%) before and after heating was calculated, and the presence or absence of heat resistance was determined according to the following criteria.
A: Volume change rate of the foam is 1% or less.
A: The volume change rate of the foam is more than 1% and 3% or less.
(Triangle | delta): Volume change rate of a foam exceeds 3% and is 5% or less.
X: Volume change rate of the foam exceeds 5%.

(6) Adhesive resistance After preparing the foam, after adjusting the condition for 10 days in a constant temperature room at 23 ° C. and 55% humidity, a test piece having a thickness of 25 mm × length of 300 mm × width of 100 mm was cut out and manufactured by Konishi Co., Ltd. After applying a bond [trade name: G17, (chloroprene rubber solvent type, main solvent: toluene, hexane, ethyl acetate)] of 0.5 kg / m ² , the state of the foam surface was observed.
○: Dissolution / disintegration of foam surface, no irregularities.
Δ: Some irregularities on the surface of the foam.
X: The foam surface is dissolved and disintegrated.

(7) Plasticizer resistance After preparing the foam, after adjusting the condition for 10 days in a constant temperature room at 23 ° C. and 55% humidity, cut out a test piece having a thickness of 25 mm × a length of 300 mm × a width of 100 mm. It was immersed in 200 ml of DOP (di-2-ethylhexyl phthalate) as a plasticizer for 24 hours, and the foam shape after taking out was observed.
○: Dissolution / disintegration of foam and no unevenness.
X: Dissolution / disintegration of foam or unevenness.

(8) Moisture permeability The moisture permeability was measured according to the reference test of JIS A9511. Measurements were made after foaming, after conditioning for 7 days in a temperature-controlled room at 23 ° C. ± 2 ° C. and humidity 50% ± 5%, and then cut into a specified size (a disk 70 mm in diameter × 25 mm in thickness) Using.
From the moisture permeability coefficient obtained from the moisture permeability, the presence or absence of moisture permeability was judged according to the following criteria.
A: The moisture permeability coefficient is 145 ng / m ² · s · Pa or less.
○: The moisture permeability coefficient is 145 ng / m ² · s · Pa or more and 160 ng / m ² · s · Pa or less.
△: moisture permeation coefficient is less than or equal to 160ng ^/ m 2 · s · Pa ^{ultra-180ng / m 2 · s · Pa} .
X: The moisture permeability coefficient exceeds 180 ng / m ² · s · Pa.

(9) Surface properties
The surface property of the obtained foam was visually determined according to the following criteria.
Good: A foam having a beautiful skin layer having 3 or less cracks, cracks, dents and voids (pores) per 1 m in the extrusion flow direction of the foam surface.
Defect: Foam surface is a foam capable of forming only a poor skin layer having more than 3 cracks, cracks, dents and voids (pores) per 1 m in the extrusion direction of the foam surface.

Example 1
To make the composition ratio in the resin composition N-phenylmaleimide / styrene / acrylonitrile = 4% / 69.8% / 26.2%, Nippon Shokubai Co., Ltd., trade name as a copolymer (A) : Polyimirex PAS (265 ° C. × 10 kg load condition melt flow rate (hereinafter referred to as MFR) = 2.2 g / min, component ratio is N-phenylmaleimide / styrene / acrylonitrile = 40% / 50% / 10%), As Toyo Styrene Co., Ltd., trade name: Toyo AS (220 ° C. × 10 kg MFR = 1.8 g / min) was used as copolymer (B), and copolymer (A) / copolymer ( B) was mixed at a ratio of 10% / 90%. 4. Tetrabromobisphenol A (manufactured by Albemarle, trade name: SAYTEX CP2000; 5% thermogravimetric decrease starting temperature: 241 ° C., melting point: 180 ° C.) as a brominated flame retardant with respect to 100 parts of these thermoplastic resin compositions 0 parts, 0.3 part of talc (trade name: Talcan powder, manufactured by Hayashi Kasei Co., Ltd.) as a nucleating agent, 0.3 part of calcium stearate (trade name: SCP, manufactured by Sakai Chemical Co., Ltd.) as other additives And the obtained resin composition was supplied at a rate of 50 kg / hour to a two-stage connected extruder in which a first-stage extruder having a diameter of 65 mm and a second-stage extruder having a diameter of 90 mm were connected in series. . 4. The resin composition supplied to the first stage extruder is melted and kneaded by heating to about 230 ° C., and then dimethyl ether as a foaming agent in the vicinity of the tip of the first stage extruder (side connected to the second extruder). 0 part was pressed into the molten thermoplastic resin composition. Thereafter, in the second stage extruder connected to the first stage extruder, the mixture is cooled so that the resin temperature at the outlet of the second stage extruder (cooling process outlet) is 140 ° C. while being kneaded and cooled. A thermoplastic resin composition was extruded into the atmosphere from a die lip of a rectangular slit die provided at the tip of the machine, and a molding die (surface material: surface-treated with polytetrafluoroethylene resin) through which oil at 100 ° C. was passed. An extruded foam plate having a cross-sectional shape having a thickness of about 30 mm and a width of about 100 mm was obtained using iron, height 25 mm × width 120 mm, and a forming roll. The temperature of the die lip was set to 130 ° C., and the gap was a rectangular cross section having a thickness direction of 2 mm and a width direction of 50 mm.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 2)
Except that 5.0 parts of hexabromocyclododecane (trade name: SAYTEX HP900; 5% thermal weight loss starting temperature: 244 ° C., melting point: 180 ° C.) bromine flame retardant was used, the same as in Example 1 Extruded foam was obtained under the conditions.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 3)
In order to make the composition ratio in the resin composition N-phenylmaleimide / styrene / acrylonitrile = 12% / 65.4% / 22.6%, the mixing ratio of copolymer (A) / copolymer (B) Was changed to 30% / 70%, and 10.0 parts of a brominated flame retardant was used as decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.). , The heating temperature in the first stage extruder is about 240 ° C., the resin temperature at the outlet of the second stage extruder (cooling process outlet) is 150 ° C., the slit die temperature is 135 ° C., the mold temperature is Extruded foam was obtained under the same conditions as in Example 1 except that the temperature was set to 125 ° C.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 4
Bromine flame retardant was decabromodiphenyl ether (trade name: SAYTEX 102E manufactured by Albemarle; 5% thermogravimetric decrease starting temperature: 326 ° C., melting point: 304 ° C.) 6.0 parts, antimony trioxide as flame retardant aid (Suzuhiro) Extruded foam was obtained under the same conditions as in Example 3 except that 2.0 parts by chemical and trade name: FIRE CUT AT-3) were used.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 5)
Bromine flame retardant: 6.0 parts ethylene bis (pentabromophenyl) (manufactured by Albemarle, trade name: SAYTEX 8010; 5% thermal weight loss start temperature: 344 ° C., melting point: 350 ° C.), trioxide as flame retardant aid Extruded foam was obtained under the same conditions as in Example 3 except that 2.0 parts of antimony (manufactured by Suzuhiro Chemical, trade name: FIRE CUT AT-3) was used.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 6)
Bromine-based flame retardant, 8.0 parts of bis (2,4,6-tribromophenoxy) ethane (manufactured by Great Lakes, trade name: FF680; 5% thermal weight loss starting temperature: 276 ° C., melting point: 225 ° C.) was used. Except for the above, an extruded foam was obtained under the same conditions as in Example 3.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 7)
Bromine flame retardant is 8.0 parts of tetrabromobisphenol A diglycidyl ether copolymer (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., trade name: SR-T5000; 5% thermal weight reduction start temperature: 360 ° C., softening point: 190 ° C.) Extruded foam was obtained under the same conditions as in Example 3, except that 2.0 parts of antimony trioxide (trade name: FIRE CUT AT-3, manufactured by Suzuhiro Chemical) was used as an auxiliary agent.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 8)
Bromine-based flame retardant is a tribromophenol adduct of tetrabromobisphenol A diglycidyl ether copolymer (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., trade name: SR-T3040; 5% thermogravimetric decrease starting temperature: 360 ° C., softening point: 170 ° C.) 8 Extruded foam was obtained under the same conditions as in Example 3 except that 2.0 parts of antimony trioxide (trade name: FIRE CUT AT-3), 2.0 parts of flame retardant aid was used. It was.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 9
Brominated flame retardant 2,4,6-tris (2,4,6-tribromophenoxy) 1,3,5-triazine (manufactured by ICL, trade name: FR245; 5% thermal weight loss start temperature: 385 ° C., The same conditions as in Example 3 except that 6.0 parts of melting point: 230 ° C. and 2.0 parts of antimony trioxide (manufactured by Suzuhiro Chemical Co., Ltd., trade name: FIRE CUT AT-3) were used as a flame retardant aid. Thus, an extruded foam was obtained.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 10)
Except for using 6.0 parts of tris (tribromoneopentyl) phosphate (made by Daihachi Chemical, trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) bromine flame retardant An extruded foam was obtained under the same conditions as in Example 3.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 11
Brominated flame retardants were decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 4.0% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.) 4.0 parts, and tris (tribromoneopentyl) phosphate (large Extruded foam was obtained under the same conditions as in Example 3 except that 2.0 parts by Hachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) were used.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 12
To make the composition ratio in the resin composition N-phenylmaleimide / styrene / acrylonitrile = 24% / 58.8% / 17.2%, Nippon Shokubai Co., Ltd., trade name as a copolymer (A) : Polyimirex PAS [265 ° C. × 10 kg melt flow rate (hereinafter referred to as MFR) = 2.2 g / min, component ratio is N-phenylmaleimide / styrene / acrylonitrile = 40% / 50% / 10%], As Toyo Styrene Co., Ltd., trade name: Toyo AS [220 ° C. × 10 kg MFR = 1.8 g / min] was used as copolymer (B), copolymer (A) / copolymer ( B) is mixed at a ratio of 60% / 40%, the heating temperature in the first stage extruder is about 250 ° C., and the resin temperature at the second stage extruder outlet (cooling process outlet) is cooled to about 170 ° C., Dairy Extruded foam was obtained under the same conditions as in Example 3 except that the temperature of the cup was set to 150 ° C. and the temperature of the molding die was set to 145 ° C.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 13)
Brominated flame retardants were decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 4.0% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.) 4.0 parts, and tris (tribromoneopentyl) phosphate (large Extruded foam was obtained under the same conditions as in Example 12 except that 2.0 parts by Hachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) were used.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 14)
Extruded foam was obtained under the same conditions as in Example 4 except that the foaming agent type was changed to 3.0 parts of dimethyl ether and 3.5 parts of normal butane, and 0.1 part of talc as a nucleating agent was used. It was.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 15)
The same conditions as in Example 4 were applied except that the blowing agent type was changed to 3.0 parts of dimethyl ether, 1.0 part of isobutane, and 2.5 parts of normal butane, and 0.1 part of talc as a nucleating agent was used. Thus, an extruded foam was obtained.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 16)
The foaming agent type was changed to 3.0 parts of dimethyl ether, 1.0 part of isobutane, 2.5 parts of normal butane, and 0.5 parts of water, and the brominated flame retardant was decabromodiphenyl ether (trade name: SAYTEX 102E manufactured by Albemarle; 5% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C., 8.0 parts, antimony trioxide (product name: FIRE CUT AT-3) 2.0 parts used as a flame retardant aid An extruded foam was obtained under the same conditions as in Example 3 except that 0.1 part of talc as a nucleating agent and 1.0 part of bentonite as a water absorbing agent were used.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 17)
The same conditions as in Example 16 except that 6.0 parts of brominated flame retardant was used decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.). An extruded foam was obtained.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 18)
Brominated flame retardants were decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 4.0% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.) 4.0 parts, and tris (tribromoneopentyl) phosphate (large Extruded foam was obtained under the same conditions as in Example 16 except that 4.0 parts were used, manufactured by Hachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 19
Brominated flame retardants were decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.) 5.0 parts, and tris (tribromoneopentyl) phosphate (large Extruded foam was obtained under the same conditions as in Example 16 except that 5.0 parts by Hachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) were used.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 20)
Extruded foam was obtained under the same conditions as in Example 19 except that the foaming agent type was changed to 3.0 parts of dimethyl ether, 1.0 part of isobutane, 2.5 parts of normal butane, and 1.0 part of ethanol.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 21)
Extruded under the same conditions as in Example 19 except that the blowing agent type was changed to 3.0 parts of dimethyl ether, 1.0 part of isobutane, 2.5 parts of normal butane, 0.5 part of water, and 0.5 part of ethanol. A foam was obtained.
The properties of the obtained foam are shown in Table 1. Compared with the following Comparative Examples 1-5, the foam excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Comparative Example 1)
Except that 2.0 parts of tris (tribromoneopentyl) phosphate (made by Daihachi Chemical Co., Ltd., trade name: CR900; 5% thermal weight loss starting temperature: 310 ° C., melting point: 180 ° C.) was used as a brominated flame retardant An extruded foam was obtained under the same conditions as in Example 21.
The properties of the obtained foam are shown in Table 2. Compared with Examples 1-21, although heat resistance and chemical resistance are satisfied, flame retardance cannot be satisfied.

(Comparative Example 2)
Example 21 except that 20 parts of tris (tribromoneopentyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., trade name: CR900; 5% thermal weight loss start temperature: 310 ° C., melting point: 180 ° C.) was used as the brominated flame retardant. Extruded foams were obtained under the same conditions as above.
The properties of the obtained foam are shown in Table 2. Compared with Examples 1-21, although flame retardance and chemical resistance are satisfied, heat resistance cannot be satisfied. In addition, as the amount of brominated flame retardant added increased, molding defects due to fluctuations in extrusion occurred.

(Comparative Example 3)
Use bromine flame retardant 10.0 parts of tetrabromobisphenol A bis (2,3-dibromopropyl ether) (manufactured by Albemarle, trade name: SAYTEX HP800A; 5% thermogravimetric decrease starting temperature: 312 ° C, melting point: 110 ° C) Except that, an extruded foam was obtained under the same conditions as in Example 21.
The properties of the obtained foam are shown in Table 2. Compared with Examples 1-21, although flame retardance and chemical resistance are satisfied, heat resistance cannot be satisfied. In addition, due to the low melting point of brominated flame retardants, molding defects due to poor resin feed occurred.

(Comparative Example 4)
Except for using 10.0 parts of a brominated flame retardant tetrabromocyclooctane (manufactured by Albemarle, trade name: SAYTEX BC48; 5% thermogravimetric decrease starting temperature: 167 ° C., melting point: 103 ° C.), the same as in Example 21 An extruded foam was obtained under the conditions.
The properties of the obtained foam are shown in Table 2. Compared with Examples 1-21, although flame retardance and chemical resistance are satisfied, heat resistance cannot be satisfied. In addition, poor resin feeding due to the low melting point of brominated flame retardants and molding defects due to resin deterioration due to flame retardant decomposition occurred.

(Comparative Example 5)
The base resin was changed to polystyrene resin (manufactured by PS Japan Co., Ltd., trade name: G9401, MFR = 0.2 g / min at 200 ° C. × 5 kg), and the heating temperature in the first stage extruder was about 230 ° C. In Example 21, except that the resin temperature at the outlet of the second stage extruder (cooling process outlet) was cooled to about 130 ° C., the die lip temperature was set to 100 ° C., and the mold temperature was set to 80 ° C. An extruded foam was obtained under the same conditions.
The properties of the obtained foam are shown in Table 2. Compared with Examples 1-21, although flame retardance is satisfied, heat resistance and chemical resistance cannot be satisfied.

(Reference Example 1)
Extrusion was carried out under the same conditions as in Example 11 except that the resin temperature at the outlet of the second stage extruder (cooling process outlet) was cooled to 200 ° C. and the die lip temperature was changed to 180 ° C. However, because the resin temperature is high, the slit pressure decreases due to gas jetting or foaming in the die, extrudability deteriorates, and only a poor shape / surface can be obtained, and a satisfactory foam cannot be obtained. It was.

(Reference Example 2)
Except that the resin temperature at the outlet of the second stage extruder (cooling process outlet) is cooled to 150 ° C., and the mold temperature is set to 30 ° C. by passing water through the mold, Extrusion was carried out under the same conditions as in Example 11. However, since the mold temperature is low, the cracks on the surface due to the occurrence of blistering from the inside of the foam become extremely large, and only a poor shape / surface can be obtained, and a satisfactory foam cannot be obtained. It was.

(Reference Example 3)
Extrusion was carried out under the same conditions as in Example 21 except that the resin temperature at the outlet of the second stage extruder (cooling step outlet) was cooled to 200 ° C. and the die lip temperature was changed to 180 ° C. However, because the resin temperature is high, the slit pressure decreases due to gas jetting or foaming in the die, extrudability deteriorates, and only a poor shape / surface can be obtained, and a satisfactory foam cannot be obtained. It was.

(Reference Example 4)
Except that the resin temperature at the outlet of the second stage extruder (cooling process outlet) is cooled to 150 ° C., and the mold temperature is set to 30 ° C. by passing water through the mold, Extrusion was performed under the same conditions as in Example 21. However, since the mold temperature is low, the cracks on the surface due to the occurrence of blistering from the inside of the foam become extremely large, and only a poor shape / surface can be obtained, and a satisfactory foam cannot be obtained. It was.

Claims (8)

Thermoplasticity comprising N-alkyl-substituted maleimide units of 0.04 wt% or more and less than 30 wt%, aromatic vinyl units of 40 to 75 wt% and vinyl cyanide units of 10 to 33 wt% (total of 3 units is 100 wt%) A thermoplastic resin foam obtained by foaming a resin composition,
3 to at least one flame retardant selected from brominated flame retardants having a 5% thermogravimetric decrease starting temperature of 230 ° C. or higher and a melting point or softening point of 150 ° C. or higher with respect to 100 parts by weight of the thermoplastic resin composition. A thermoplastic resin foam characterized by containing 15 parts by weight and having a foam thickness of 10 to 150 mm.   The thermoplastic resin foam according to claim 1, wherein the aromatic vinyl unit is a styrene unit.   The thermoplastic resin foam according to claim 1 or 2, wherein the N-alkyl-substituted maleimide unit is an N-phenylmaleimide unit.   The thermoplastic resin foam according to any one of claims 1 to 3, wherein the vinyl cyanide unit is acrylonitrile. The thermoplastic resin foam according to claim 1, wherein the moisture permeability coefficient of the foam is 160 ng / m ² · s · Pa or less.   Brominated flame retardants with a 5% thermal weight loss starting temperature of 230 ° C or higher and a melting point or softening point of 150 ° C or higher are tetrabromobisphenol A, hexabromocyclododecane, decabromodiphenyl ether, ethylenebis (pentabromophenyl) Bis (2,4,6-tribromophenoxy) ethane, tetrabromobisphenol A diglycidyl ether copolymer, tribromophenol adduct of tetrabromobisphenol A diglycidyl ether copolymer, 2,4,6 tris (2,4,6 The thermoplastic resin foam according to any one of claims 1 to 5, which is 6-tribromophenoxy) 1,3,5-triazine or tris (tribromoneopentyl) phosphate.   Furthermore, 0.1-5 weight part of antimony compounds are contained as a flame retardant adjuvant with respect to 100 weight part of thermoplastic resin compositions, The thermoplasticity in any one of Claims 1-6 characterized by the above-mentioned. Resin foam.   The thermoplastic resin foam according to any one of claims 1 to 7, wherein the antimony compound is antimony trioxide.