JP5248041B2 - Thermoplastic resin foam - Google Patents

Description

The present invention, heat resistance, such as those used in construction for insulation, chemical resistance, excellent flame retardancy, further relates to method for producing a thermoplastic resin extruded foams having both thermoplastic.

  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 has poor material recyclability and excellent 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 obtaining a foam from the resin composition, the fluidity and elongation of the molten resin composition containing the foaming agent are reduced, and thus it is particularly difficult to mold a thick plate-like foam molded article. .
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 has excellent heat resistance, chemical resistance, moldability, and environmental compatibility that enables material recycling. Therefore, the development of a thermoplastic resin foam that meets the flame retardancy required for building material applications is 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 purpose of the present invention is excellent in heat resistance, chemical resistance, moldability, environmental compatibility that enables material recycling, and, moreover, a thick wall that meets the flame retardancy required for building materials. It is to provide a thermoplastic resin extruded foam.

As a result of diligent research in view of the prior art, the present inventors have found that a copolymer imparted with heat resistance and chemical resistance from the viewpoint of heat resistance and chemical resistance, and chemical resistance and fluidity. From a viewpoint, extrusion foaming of a resin composition containing a specific brominated flame retardant and, if necessary, an antimony compound as a flame retardant aid, into a thermoplastic resin mixture made of a copolymer with chemical resistance and fluidity It has been found that the extruded foam obtained satisfies the above-mentioned purpose, and the present invention has been completed.

That is, the present invention
[1] Copolymer comprising aromatic vinyl unit, unsaturated dicarboxylic anhydride unit and N-substituted maleimide unit (A) 20% by weight or more and less than 50% by weight and copolymer comprising aromatic vinyl unit and vinyl cyanide unit With respect to 100 parts by weight of the thermoplastic resin mixture comprising more than 50% by weight and not more than 80% by weight of the polymer (B),
Heat and melt a thermoplastic resin composition containing 3 to 15 parts by weight of a flame retardant selected from brominated flame retardants having a 5% thermal weight loss starting temperature of 276 ° C. or higher and a melting point or softening point of 150 ° C. or higher. Adding a foaming agent to form a foamable gel material,
Cooling the gelled material;
Extruding the gel-like substance through a slit die into a lower pressure region, and forming an extruded foam by forming using a molding die placed in close contact with or in contact with the slit die Is a method for producing a thermoplastic resin extruded foam having a thickness of 10 to 150 mm,
In the step of forming the extruded foam, the resin foam of the gel substance at the outlet of the cooling step is 20 to 70 ° C. higher than the glass transition temperature of the thermoplastic resin mixture. Reducing the resistance between the body surface and the molding die, and gradually cooling the foam in the molding die, a method for producing a thermoplastic resin extruded foam,
[2] The method for producing a thermoplastic resin extruded foam according to [ 1 ], wherein the die temperature is a temperature lower by 5 to 50 ° C. than the resin temperature.
[3] The resistance between the extruded foam and the molding die is reduced by placing a material having a low surface resistance at the interface between the surface of the extruded foam and the molding die, [ 1 ] or [ 2 ] [ 1 ] to [ 3 ], wherein the foam is gradually cooled in the molding die by adjusting the temperature of the molding die. It relates to the manufacturing method of the thermoplastic resin extrusion foam in any one of these.

According to the present invention, a thick thermoplastic resin excellent in heat resistance, chemical resistance, moldability, environmental compatibility capable of material recycling, and in addition to the flame retardancy required for building materials. An extruded foam can be obtained.

In particular, it is possible to obtain a thermoplastic resin extruded foam that satisfies the required quality of heat resistance and chemical resistance, which 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. Even when an adhesive that has been used, or a plasticizer contained in a waterproof sheet, is used, it is possible to obtain a thermoplastic resin extruded foam that does not cause shape deformation such as melt collapse of the foam.

  Hereinafter, the present invention will be described in detail.

The copolymer (A) used in the present invention comprises an aromatic vinyl unit, an unsaturated dicarboxylic anhydride unit, and an N- substituted maleimide 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 preferred from the viewpoint of compatibility with the copolymer (B) and ease of polymerization, and styrene, which is inexpensive in price, is most preferred.

  Examples of the unsaturated dicarboxylic acid anhydride unit include maleic anhydride, itaconic anhydride, and citraconic anhydride. From the viewpoint of compatibility with the copolymer (B), ease of polymerization, and low cost, maleic anhydride. Acid is preferred.

  Furthermore, as N-alkyl substituted maleimide units, N-methylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-4-diphenylmaleimide, N-2-chlorophenylmaleimide, N-4-bromo Examples thereof include phenylmaleimide and N-1-naphthylmaleimide, and N-phenylmaleimide is optimal from the viewpoint of compatibility with the copolymer (B), ease of polymerization, and low cost.

  When the total amount of the aromatic vinyl unit, unsaturated dicarboxylic acid anhydride unit and N-alkyl substituted maleimide unit is 100% by weight, the N-alkyl substituted maleimide unit is 40% by weight or more in view of heat resistance. In consideration of water absorption resistance and moisture absorption, the unsaturated dicarboxylic acid anhydride unit is preferably 5% by weight or less.

  The copolymer (B) used in the present invention comprises an aromatic vinyl unit and a vinyl cyanide unit.

  As the aromatic vinyl unit, as described above, styrene and α-methylstyrene are preferable from the viewpoint of compatibility with the copolymer (A) and ease of polymerization, and styrene which is inexpensive in price. Is the best.

  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, a copolymer of styrene and acrylonitrile is preferable.

  The thermoplastic resin composition in the present invention is a thermoplastic resin composition containing a thermoplastic resin mixture comprising the copolymer (A) and the copolymer (B).

  The thermoplastic resin composition in the present invention is preferably such that the resin mixture is contained in an amount of 50% by weight or more, more preferably 70% by weight or more based on the entire thermoplastic resin composition.

In the present invention, the weight ratio of the copolymer (A) to the copolymer (B) in the resin mixture (the total amount of (A) and (B) is 100% by weight) is determined by the copolymer (A). 0.1 wt% or more and less than 50 wt% and copolymer (B) is preferably more than 50 wt% and 99.9 wt% or less, and copolymer (A) is 10 wt% or more and less than 50 wt% and copolymer (B) is more preferably more than 50% by weight and less than 90% by weight, more preferably the copolymer (A) is 20% by weight or more and less than 50% by weight and the copolymer (B) is more than 50% by weight and less than 80% by weight. .
If the copolymer (A) is in the range of 0.1% by weight or more and less than 50% by weight, 100 ° C. heat resistance and chemical resistance can both be achieved, which is preferable.

  As a foaming agent for obtaining the thermoplastic resin foam of the present invention, a foaming agent containing no chlorine atom with respect to 100 parts by weight of the thermoplastic resin mixture comprising the copolymer (A) and the copolymer (B). Can be used. 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, 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.

  Examples of the physical blowing agent include hydrocarbons such as propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, cyclopentane, hexane, 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 , 1,2,2-pentafluoroethane, fluorinated hydrocarbons such as difluoromethane, trifluoromethane, dimethyl ether, diethyl ether, methyl ethyl ether, isopropyl ether, n-butyl ether, diisoamyl ether, furan, furfural, 2- Ethers such as methylfuran, 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, methyl propionate, ethyl propionate, etc. Carboxylic acid esters, methanol, ethanol, propyl alcohol, i-propyl alcohol, butyl alcohol, i-butyl alcohol, t-butyl alcohol and other alcohols, dimethyl ketone, methyl ethyl ketone, diethyl ketone, methyl-n-propyl ketone, methyl Ketones such as -n-butyl ketone, methyl-i-butyl ketone, methyl-n-amyl ketone, methyl-n-hexyl ketone, ethyl-n-propyl ketone, ethyl-n-butyl ketone, or Carbon dioxide, nitrogen, water, argon, and inorganic foaming agents such as helium. These can be used alone or in admixture of two or more.

  Examples of the chemical foaming agent include N, N′-dinitrosopentamethylenetetramine, p, p′-oxybis-benzenesulfonylhydrazide, hydrazodicarbonamide, sodium carbonate, azodicarbonamide, terephthalazide, and 5-phenyltetrazole. , P-toluenesulfonyl semicarbazide and the like, and these can be used alone or in admixture of two or more.

  Among these foaming agents, hydrocarbons such as propane, n-butane, i-butane, n-pentane, i-pentane, neopentane, cyclopentane, dimethyl ether, diethyl ether, and methyl ethyl ether are used to protect the ozone layer. Ethers such as methanol, ethanol, propyl alcohol, i-propyl alcohol, alcohols such as butyl alcohol, i-butyl alcohol and t-butyl alcohol, alkyl chlorides such as methyl chloride and ethyl chloride, carbon dioxide, nitrogen, An inorganic foaming agent such as water is 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 mixture. 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 mixture. Part 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 mixture. If the usage-amount of hydrocarbon exists in the range of 0-6 weight part, the gas dispersibility to a 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, and pentabromotoluene. , Ethylenebis (pentabromophenyl), decabromodiphenyl ether, bis (2,4,6-tribromophenoxy) ethane, pentabromobenzyl acrylate polymer, tetrabromobisphenol A, tetrabromobisphenol A diglycidyl ether copolymer, tetrabromobisphenol Tribromophenol adduct of A diglycidyl ether copolymer, tetrabromobisphenol S, tetrabromobisphenol A polycarbonate oligomer, ethylenebistetrabromophthalimide, 2, , 6- tris (2,4,6-tribromophenoxy) 1,3,5-triazine, and tris (tribromoneopentyl) phosphate can be mentioned.

  Among the brominated flame retardants, tetrabromobisphenol A and hexabromocyclododecane have good dispersibility with the thermoplastic resin composition, little adverse effect 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 are 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. That is, the 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.

  Judgment criteria for flame retardancy are as follows: 1) The average flame extinguishing time of 5 test specimens is within 3 seconds, 2) no residual dust, 3) each test specimen has a combustion limit indicating line (ignition limit) It is required not to burn more than 20 mm from the indicated 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 thermoplastic resin mixture, if necessary, as various additives within the range assuming the effects of the present invention, nucleating agent, stabilizer, lubricant, antistatic agent, plasticizer, You may mix | blend additives, such as a water absorbing 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. Moreover, when the foam thickness exceeds 150 mm, the closed cell ratio tends to decrease, 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 to 60 kg / ^{m 3.} If the foam density is within 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 of the thermoplastic resin foam in 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 the sample 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. If the bubble diameter is less than the above range, the heat-insulating material has poor moldability, and stable production tends to be difficult. When the bubble diameter exceeds the above range, the appearance of the surface of the heat insulating material tends 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 mixture is supplied to a known heat-melting and kneading apparatus such as an extruder and melted by heating, and a step of adding a foaming agent under a high-pressure condition, a step of forming a foamable gel substance Then, the step of cooling the gel-like substance, the step of extruding and foaming the gel-like substance into the low-pressure region through a die such as a slit die from the high-pressure region, and the molding die placed in close contact with or in contact with the die A thick plate-like thermoplastic resin foam can be obtained through the step of forming the foam to be shaped.

  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 a flame retardant to the thermoplastic resin mixture, for example, (1) after adding and mixing various additives such as a flame retardant to the thermoplastic resin mixture, A procedure for supplying to a melt-kneading apparatus and heating and melting, and further adding and mixing a foaming agent. (2) After supplying a thermoplastic resin mixture to a melt-kneading apparatus such as an extruder and heating and melting, a flame retardant, etc. Procedures of adding and mixing various additives, and further adding and mixing a foaming agent, (3) obtained by previously adding various additives such as flame retardant to the thermoplastic resin mixture and melt-kneading Although the resin composition is again supplied to an extruder and melted by heating, a procedure for adding and mixing a foaming agent is included, but the timing of adding various additives to the thermoplastic resin mixture 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 means when the thermoplastic resin mixture, foaming agent, and various additives added as necessary are heated and melt kneaded. There is no particular limitation on the above.

  The heating temperature may be equal to or higher than the temperature at which the thermoplastic resin mixture melts (glass transition temperature or melting point), but is preferably a temperature at which decomposition and deterioration of the resin due to the influence of a flame retardant and the like are 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., so it cannot be determined unconditionally, but the thermoplastic resin mixture and the foaming agent or additive are uniformly dispersed and mixed. The time required is set as appropriate.

  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 foaming agent is required, the twin screw type is preferable as the extruder. 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 mixture, More preferably, the temperature is 20 to 60 ° C. higher. 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 the 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.

  Examples of the shape of the slit die include a rectangular shape, a coat hanger shape, a fish tail shape, and the like, but when a wide plate-like foam is to be obtained, a coat hanger shape or a fish tail shape slit die is preferable. .

Furthermore, when trying to obtain a plate-like foam having a thickness of 10 to 150 mm, from the viewpoint of suppressing the dimensional enlargement ratio in the thickness direction and the dimensional enlargement ratio in the width direction of the molding die shape relative 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, the thermoplastic resin mixture composed of the copolymer (A) and the copolymer (B) in the present invention tends to be brittle with respect to the polystyrene-based resin, so that the expansion rate in the width direction is suppressed as much as possible. It is preferred to select a method.
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 thermoplastic resin foam having both heat resistance, chemical resistance, and flame retardancy of the present invention will be described in detail by way of specific examples, but the present invention is not limited to only such examples. . Unless otherwise specified, “part” represents “part by weight” and “%” represents “% by weight”.

  About the characteristic of the foam obtained by Examples 1-32 shown below, Reference Examples 1-4, and Comparative Examples 1-6, a foam density, an average cell diameter, JIS A9511 combustibility, a foam oxygen index, 100 The heat resistance at 0 ° C., the adhesive resistance, the plasticizer resistance, and the surface property 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 About the foam which passed 7 days after manufacture, it measured using the test piece of thickness 10mm * length 150mm * width 10mm according to JISK7201.

(5) 100 ° C. heat resistance (volume change rate of foam)
After creating the foam, the condition was adjusted for 10 days in a constant temperature room at 23 ° C. and 55% humidity, and then a test piece having a thickness of 25 mm × width of 100 mm × length of 100 mm was cut out in a hot air dryer set to 100 ° C. ± 2 ° C. It heated for 24 hours, the volume change rate (%) before and after a heating was computed, and the presence or absence of heat resistance was judged with the following references | standards.
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 the foam was prepared, the condition was adjusted for 10 days in a constant temperature room at 23 ° C. and 55% humidity, and then a test piece having a thickness of 25 mm × width of 100 mm × length of 300 mm was cut out and specified for waterproof adhesion to a rubber sheet. After applying 0.4 kg / m ^{2 of an} agent (manufactured by Mitsuboshi Belting: “Neobond RW” (solvent: toluene / 50-60%, gasoline / 10-20%, xylene / 10%)), 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: Dissolution / disintegration of the foam surface.

(7) Plasticizer resistance After the foam was prepared, after conditioning for 10 days in a constant temperature room at 23 ° C. and 55% humidity, a test piece having a thickness of 25 mm × width of 100 mm × length of 300 mm was cut out to obtain a length of 50 mm. It was immersed in DOP (200 ml) 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) Surface property
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
As a copolymer (A), manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: DENKA IP (265 ° C. × 10 kg melt flow rate (hereinafter referred to as MFR) = 0.2 g / min), copolymer (B) Manufactured by Toyo Styrene Co., Ltd., trade name: Toyo AS (220 ° C. × 10 kg, MFR = 1.8 g / min), copolymer (A) / copolymer (B) 10% / Mixing at a ratio of 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 the obtained thermoplastic resin mixture 0 part, 0.3 part of talc (trade name: Talcan powder, manufactured by Hayashi Kasei Co., Ltd.) as a nucleating agent was dry blended, and the resulting resin composition was mixed with a single screw extruder having a diameter of 65 mm and a single diameter of 90 mm. It supplied to the two-stage connection type extruder which connected the axial extruder in series. The resin composition supplied to the first stage extruder was melted and kneaded by heating to about 230 ° C., and then 5.0 parts of dimethyl ether was press-fitted into the resin near the tip of the first stage extruder as a foaming agent. The resin temperature at the outlet of the second stage extruder (cooling process outlet) was then cooled to about 140 ° C. while kneading and cooling with the connected second stage extruder having a diameter of 90 mm, and the rectangular provided at the tip of the second stage extruder. Thickness with a molding die (surface material: iron 25 mm in height x 120 mm in width) which was extruded into the atmosphere from the die lip of the shape slit die and allowed to pass oil at 100 ° C (surface material: iron treated with polytetrafluoroethylene resin: height 25 mm x width 120 mm) An extruded foam plate having a cross-sectional shape having a length of about 30 mm and a width of about 100 mm was obtained. 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 Comparative Examples 1-6, the foam which was 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 3)
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 1.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 4
The mixing ratio of copolymer (A) / copolymer (B) was changed to 20% / 80%, and brominated flame retardant was decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight reduction start Using 10.0 parts (temperature: 326 ° C., melting point: 304 ° C.), the heating temperature in the first stage extruder is about 235 ° C., and the resin temperature at the outlet of the second stage extruder (cooling process outlet) is cooled to about 145 ° C. An extruded foam was obtained under the same conditions as in Example 1 except that the temperature of the die lip was set to 135 ° C. and the temperature of the molding die was set to 110 ° C.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 5)
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 4.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 6)
The mixing ratio of copolymer (A) / copolymer (B) was changed to 30% / 70% and brominated flame retardant was decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight reduction start (Temperature: 326 ° C., melting point: 304 ° C.) 10.0 parts are used, the heating temperature in the first stage extruder is about 240 ° C., and the resin temperature at the outlet of the second stage extruder (cooling process outlet) is cooled to about 150 ° C. An extruded foam was obtained under the same conditions as in Example 1 except that the temperature of the die lip was set to 140 ° C. and the temperature of the molding die was set to 120 ° C.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 7)
Bromine flame retardant was decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 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 6 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 8)
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 6 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

Example 9
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 6.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 10)
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.) An extruded foam was obtained under the same conditions as in Example 6 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 11)
A brominated flame retardant was added to a tribromophenol adduct of tetrabromobisphenol A diglycidyl ether copolymer (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., trade name: SR-T3040; 5% thermal weight reduction start temperature: 360 ° C., softening point: 170 ° C.) 8 Extruded foam was obtained under the same conditions as in Example 6 except that 2.0 parts of 2.0 parts of antimony trioxide (trade name: FIRE CUT AT-3) was used as a flame retardant aid. It was.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 12)
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 6 except that 8.0 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 13)
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 6.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 14)
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 6 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 15)
The mixing ratio of copolymer (A) / copolymer (B) was changed to 45% / 55%, and brominated flame retardant was decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight reduction start Using 10.0 parts (temperature: 326 ° C., melting point: 304 ° C.), 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 160 ° C. An extruded foam was obtained under the same conditions as in Example 1 except that the temperature of the die lip was set to 150 ° C. and the temperature of the molding die was set to 140 ° C.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 16)
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 15.
The properties of the obtained foam are shown in Table 1. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 17)
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 15 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 Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 18)
Foaming agent: 3.0 parts of dimethyl ether, 3.0 parts of normal butane, and brominated flame retardant: hexabromocyclododecane (manufactured by Albemarle, trade name: SAYTEX HP900; 5% thermogravimetric decrease starting temperature: 244 ° C, melting point: 180 ° C ) 4.0 parts, and tris (tribromoneopentyl) phosphate (manufactured by Daihachi Chemical, trade name: CR900; 5% thermal weight loss starting temperature: 310 ° C., melting point: 180 ° C.) 2.0 parts, nucleating agent Extruded foams were obtained under the same conditions as in Example 1 except that 0.1 part of talc was used.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 19)
Bromine flame retardant was decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.) 8.0 parts, antimony trioxide as flame retardant aid (Suzuhiro) Extruded foam was obtained under the same conditions as in Example 18 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 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 20)
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 18 except that 3.0 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 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 21)
The foaming agent is 3.0 parts of dimethyl ether, 3.5 parts of normal butane, 1.0 part of ethanol, and the brominated flame retardant is decabromodiphenyl ether (manufactured by Albemarle, trade name: SAYTEX 102E; 5% thermal weight reduction start temperature: 326 ° C. , Melting point: 304 ° C.) 4.0 parts, and tris (tribromoneopentyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) 4.0 Extruded foam was obtained under the same conditions as in Example 18 except that 1.0 part of bentonite was used without using talc which is a nucleating agent.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 22)
The mixing ratio of copolymer (A) / copolymer (B) was changed to 20% / 80%, the heating temperature in the first stage extruder was about 235 ° C., and the outlet of the second stage extruder (cooling process outlet). The extruded foam was obtained under the same conditions as in Example 20, except that the resin temperature was set to about 145 ° C., the die lip temperature was set to 135 ° C., and the mold temperature was set to 110 ° C.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 23)
The mixing ratio of copolymer (A) / copolymer (B) was changed to 30% / 70%, the heating temperature in the first stage extruder was about 240 ° C., and the outlet of the second stage extruder (cooling process outlet). The extruded foam was obtained under the same conditions as in Example 19 except that the resin temperature was cooled to about 150 ° C., the die lip temperature was set to 140 ° C., and the mold temperature was set to 120 ° C.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 24)
Except for using 8.0 parts of tris (tribromoneopentyl) phosphate (made by Daihachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) as a brominated flame retardant An extruded foam was obtained under the same conditions as in Example 23.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 25)
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 23, except that 3.0 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 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 26)
Extruded foams were obtained under the same conditions as in Example 25 except that 4.0 parts of dimethyl ether and 2.0 parts of isobutane were used.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 27)
The same foaming agent as in Example 24 except that 3.0 parts of dimethyl ether, 3.5 parts of normal butane, 1.0 part of ethanol and 1.0 part of bentonite were used without using talc as a nucleating agent. An extruded foam was obtained under the conditions.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 28)
Except that 10.0 parts of tris (tribromoneopentyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease start temperature: 310 ° C., melting point: 180 ° C.) was used except that bromine flame retardant was used. An extruded foam was obtained under the same conditions as in Example 27.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 29)
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 27, 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 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 30)
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 27 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 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 31)
Decabromodiphenyl ether (trade name: SAYTEX 102E; 5% thermal weight loss starting temperature: 326 ° C., melting point: 304 ° C.) 10.0 parts brominated flame retardant, antimony trioxide (Suzuhiro) as a flame retardant aid Extruded foam was obtained under the same conditions as in Example 27 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 2. Compared with Comparative Examples 1-6, the foam which was excellent in heat resistance, chemical resistance, and a flame retardance was obtained.

(Example 32)
The mixing ratio of copolymer (A) / copolymer (B) was changed to 45% / 55%, the heating temperature in the first stage extruder was about 250 ° C., and the outlet of the second stage extruder (cooling process outlet). The extruded foam was obtained under the same conditions as in Example 30, except that the resin temperature was cooled to about 160 ° C., the die lip temperature was set to 150 ° C., and the mold temperature was set to 140 ° C.
The properties of the obtained foam are shown in Table 2. Compared with Comparative Examples 1-6, the foam which was 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 27.
Table 3 shows the properties of the obtained foam. Although heat resistance and chemical resistance are satisfied as compared with Examples 1 to 32, flame retardancy cannot be satisfied.

(Comparative Example 2)
Except that 20.0 parts of tris (tribromoneopentyl) phosphate (manufactured by Daihachi Chemical Co., Ltd., trade name: CR900; 5% thermogravimetric decrease starting temperature: 310 ° C., melting point: 180 ° C.) was used except that 20.0 parts of a brominated flame retardant was used. An extruded foam was obtained under the same conditions as in Example 27.
Table 3 shows the properties of the obtained foam. Compared with Examples 1-32, 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 27.
Table 3 shows the properties of the obtained foam. Compared with Examples 1-32, 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 27 An extruded foam was obtained under the conditions.
Table 3 shows the properties of the obtained foam. Compared with Examples 1-32, 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)
As the base resin, AS resin (manufactured by Toyo Styrene Co., Ltd., trade name: Toyo AS ... 220 ° C. × 10 kg, MFR = 1.8 g / min) was changed, and the heating temperature in the first stage extruder was changed. 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 120 ° C, and the mold temperature was set to 100 ° C. An extruded foam was obtained under the same conditions as in Example 21.
Table 3 shows the properties of the obtained foam. Although flame retardance is satisfied as compared with Examples 1 to 32, chemical resistance, particularly adhesive resistance and heat resistance, cannot be satisfied.

(Comparative Example 6)
As the base resin, polystyrene resin (manufactured by PS Japan Co., Ltd., trade name: G9401, 200 ° C. × 5 kg, MFR = 0.2 g / min) was changed, and the heating temperature in the first stage extruder was about 220 ° C. In Example 21, except that the resin temperature at the outlet of the second stage extruder (cooling process outlet) was cooled to about 125 ° C., the temperature of the die lip was set to 115 ° C., and the temperature of the molding die was set to 30 ° C. An extruded foam was obtained under the same conditions.
Table 3 shows the properties of the obtained foam. Although flame retardance is satisfied as compared with Examples 1 to 32, chemical resistance and heat resistance cannot be satisfied.

(Reference Example 1)
Extrusion was carried out under the same conditions as in Example 14 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)
Extrusion was performed under the same conditions as in Example 14 except that the mold temperature was set to 30 ° C. 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 29 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)
Extrusion was carried out under the same conditions as in Example 29 except that the mold temperature was set to 30 ° C. 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 (4)

Copolymer comprising aromatic vinyl unit, unsaturated dicarboxylic acid anhydride unit and N-substituted maleimide unit (A) 20% by weight or more and less than 50% by weight and copolymer comprising aromatic vinyl unit and vinyl cyanide unit ( B) For 100 parts by weight of a thermoplastic resin mixture comprising more than 50% by weight and not more than 80% by weight,
Thermoplastic resin containing 3 to 15 parts by weight of at least one flame retardant selected from brominated flame retardants having a 5% thermal weight loss starting temperature of 276 ° C. or higher and a melting point or softening point of 150 ° C. or higher. Heating and melting the composition, adding a foaming agent, and forming a foamable gel material;
Cooling the gelled material;
Extruding the gel-like substance through a slit die into a lower pressure region, and forming an extruded foam by forming using a molding die placed in close contact with or in contact with the slit die Is a method for producing a thermoplastic resin extruded foam having a thickness of 10 to 150 mm,
In the step of forming the extruded foam, the resin foam of the gel substance at the outlet of the cooling step is 20 to 70 ° C. higher than the glass transition temperature of the thermoplastic resin mixture. A method for producing an extruded foam of a thermoplastic resin, comprising reducing resistance between a body surface and a molding die, and gradually cooling the foam in the molding die. The method for producing a thermoplastic resin extruded foam according to claim 1 , wherein the die temperature is 5 to 50 ° C lower than the resin temperature. The heat according to claim 1 or 2 , wherein a resistance of the extruded foam and the molding die is reduced by installing a material having a small surface resistance at an interface between the surface of the extruded foam and the molding die. A method for producing an extruded foam of a plastic resin. The method for producing a thermoplastic resin extruded foam according to any one of claims 1 to 3 , wherein the foam is gradually cooled in the molding die by adjusting the temperature of the molding die.