JP2007238961A - Method for producing polystyrene resin extruded foam plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polystyrene resin extruded foam plate which suppresses metal corrosion inside an extruder and has excellent flame retardancy and excellent stability of extrusion foaming.
SOLUTION: A foamed plate having an apparent density of 22 to 60 kg / m ³ and a thickness of 10 to 150 mm is manufactured by extrusion foaming a foamable molten resin composition obtained by kneading a polystyrene resin, a flame retardant and a foaming agent. In the method, the flame retardant is selected from any of the following (i) to (v), and is added at a ratio of 0.5 to 10 parts by weight with respect to 100 parts by weight of the polystyrene-based resin. A process for producing a polystyrene-based resin extruded foam board characterized by the following.
(I) brominated isocyanurate (ii) brominated isocyanurate, diphenylalkane and / or diphenylalkene (iii) brominated bisphenol, diphenylalkane and / or diphenylalkene (iv) brominated isocyanurate and brominated bisphenol ( v) Brominated isocyanurate and brominated bisphenol and diphenylalkane and / or diphenylalkene

Description

  The present invention relates to a polystyrene resin extruded foam plate used for, for example, a heat insulating material such as a wall, floor, or roof of a building, a tatami core material, and the like, and more specifically, a polystyrene resin extruded foam having excellent flame retardancy. The present invention relates to a plate and a method for producing a flame-retardant polystyrene resin extruded foam plate having excellent extrusion stability.

  Conventionally, polystyrene-based resin extruded foam plates have excellent heat insulating properties and suitable mechanical strength, so that those molded into a plate with a constant width have been widely used as heat insulating materials. As a method for producing such a foamed plate, a method of adding a foam adjusting agent to a polystyrene resin material, adding a physical foaming agent after heat-melting and kneading, and extruding the mixture from a high pressure region to a low pressure region to foam, and further required Accordingly, a method of obtaining a thick foam plate by connecting a shaping device to the die outlet of the extruder is known.

  In order to satisfy the flammability specification of the extruded polystyrene foam heat insulating plate described in JIS A 9511 (1995), a flame retardant is added to the foamed plate. As the flame retardant, hexabromocyclododecane (hereinafter referred to as HBCD) is widely used. Since HBCD has a relatively low decomposition start temperature compared to other main flame retardants, hydrogen bromide is likely to be generated by thermal decomposition during combustion, and an active radical trapping effect is easily exhibited. Therefore, since a flame-retardant effect is acquired with a comparatively small addition, it is used suitably.

  However, the low decomposition start temperature of HBCD is also a drawback in use, and part of the flame retardant decomposes during the process of manufacturing polystyrene resin extruded foam, and the hydrogen bromide generated damages the extruder. Depending on the extrusion conditions, the flame retardant decomposes in a large amount, the effective amount decreases, and there is a possibility that problems such as failure to obtain the expected sufficient flame retardant effect may occur. Further, considering the increase in the thermal history of the flame retardant when the product is pulverized, melted, pelletized and recycled as a polystyrene resin material again, the possibility that the flame retardant thermally decomposes is considered to increase. Furthermore, the gas generated by the decomposition of HBCD may adversely affect the stability of extrusion foaming during the production of the foamed plate.

  On the other hand, chlorofluorocarbons (hereinafter referred to as CFC) such as dichlorodifluoromethane have been widely used as foaming agents used for the production of foamed plates. However, since CFC has a great risk of destroying the ozone layer, hydrogen atom-containing chlorofluorocarbon (hereinafter referred to as HCFC) having a small ozone depletion coefficient has been used in place of CFC in recent years.

  However, HCFC does not have the possibility of destroying the ozone layer because the ozone destruction coefficient is not zero. Therefore, a polystyrene resin extruded foam plate produced by using a fluorinated hydrocarbon (hereinafter referred to as HFC) or a saturated hydrocarbon having a ozone depletion coefficient of 0 and no chlorine atom in the molecule as a foaming agent has been studied. However, especially when a flammable foaming agent such as saturated hydrocarbon is used, in order to impart sufficient flame retardancy to the polystyrene-based extruded foam plate, it is more than when a nonflammable foaming agent such as HCFC is used. A lot of HBCD must be added. However, when a large amount of HBCD is added, there is a possibility that the stability of extrusion foaming is significantly impaired or the properties of the obtained foamed plate are impaired.

  The present invention has been made to solve the above-mentioned problems of polystyrene resin extruded foam plates, and suppresses metal corrosion inside the extruder and is excellent in stability of extrusion foaming. It is an object of the present invention to provide a polystyrene-based resin extruded foam plate having an excellent flame retardancy and environmental suitability.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies. As a result, the use of a specific flame retardant, the bubble diameter of the foamed plate, and the type and amount of the remaining foaming agent are set to specific values. The invention has been completed.

That is, this invention provides the manufacturing method of a polystyrene resin extrusion foamed board shown below, and a polystyrene resin extruded foam board.
(1) A method for producing a foamed plate having an apparent density of 22 to 60 kg / m ³ and a thickness of 10 to 150 mm by extrusion foaming a foamable molten resin composition obtained by kneading a polystyrene resin, a flame retardant and a foaming agent. The flame retardant is selected from any of the following (i) to (v), and is added at a ratio of 0.5 to 10 parts by weight with respect to 100 parts by weight of the polystyrene-based resin. A method for producing a polystyrene-based resin extruded foam board.
(I) brominated isocyanurate (ii) brominated isocyanurate, diphenylalkane and / or diphenylalkene (iii) brominated bisphenol, diphenylalkane and / or diphenylalkene (iv) brominated isocyanurate and brominated bisphenol ( v) Brominated isocyanurate and brominated bisphenol and diphenylalkane and / or diphenylalkene

(2) The flame retardant is a brominated flame retardant composed of brominated isocyanurate and / or brominated bisphenol, and diphenyl alkane and / or diphenyl alkene, and diphenyl alkane with respect to 100 parts by weight of the brominated flame retardant. The method for producing a polystyrene-based resin extruded foam plate according to (1), wherein diphenylalkene is blended in a proportion of 0.3 to 300 parts by weight in total.

(3) The blowing agent is (a) 10 to 90 mol% of a saturated hydrocarbon having 3 to 5 carbon atoms, and (b) an alkyl chloride having 1 or 2 carbon atoms, dimethyl ether, diethyl ether, methyl ethyl ether, methanol, ethanol One or two or more foaming agents selected from water, carbon dioxide 90 to 10 mol% (however, the total amount of the foaming agent (a) and the foaming agent (b) is 100 mol%) The method for producing a polystyrene-based resin extruded foam plate according to the above (1) or (2).

(4) In a polystyrene resin extruded foam plate with an apparent density of 22 to 60 kg / m ³ and a thickness of 10 to 150 mm, the average cell diameter in the thickness direction is 0.05 to 0.25 mm, and the isobutane content in the foam plate is a foam plate. A polystyrene-based resin extruded foam board characterized by containing 0.4 to 0.9 mol per kg and containing a flame retardant selected from any of the following (i) to (v) in the foam board: .
(I) brominated isocyanurate (ii) brominated isocyanurate, diphenylalkane and / or diphenylalkene (iii) brominated bisphenol, diphenylalkane and / or diphenylalkene (iv) brominated isocyanurate and brominated bisphenol ( v) Brominated isocyanurate and brominated bisphenol and diphenylalkane and / or diphenylalkene

(5) Polystyrene resin extruded foam plate having an apparent density of 22 to 60 kg / m ³ and a thickness of 10 to 150 mm, an average cell diameter in the thickness direction of 0.05 to 0.25 mm, and 1,1,1, The 2-tetrafluoroethane content is 0.1 to 0.8 mol per kg of the foam plate, and the saturated hydrocarbon content of 3 to 5 carbon atoms in the foam plate is 0 to 0.8 mol per kg of the foam plate. A polystyrene-based resin-extruded foamed board containing a flame retardant selected from any of the following (i) to (v) in the foamed board.
(I) brominated isocyanurate (ii) brominated isocyanurate, diphenylalkane and / or diphenylalkene (iii) brominated bisphenol, diphenylalkane and / or diphenylalkene (iv) brominated isocyanurate and brominated bisphenol ( v) Brominated isocyanurate and brominated bisphenol and diphenylalkane and / or diphenylalkene

(6) The foamed plate contains a brominated flame retardant composed of brominated isocyanurate and / or brominated bisphenol, and diphenylalkane and / or diphenylalkene (4) or ( A polystyrene-based resin extruded foam plate according to 5).

In the method of the present invention, a brominated flame retardant composed of brominated isocyanurate or brominated bisphenol having a decomposition initiation temperature higher than that of HBCD, or diphenylalkane and / or diphenylalkene that improves the flame retardant effect when used in combination with a brominated flame retardant. By using in combination with a brominated flame retardant, it is possible to provide a polystyrene resin extruded foam plate that is excellent in recyclability and moldability and ensures flame retardancy and heat insulation as described in JIS A9511 (1995). . In particular, by using diphenylalkane, it is possible to reduce the amount of brominated isocyanurate and brominated bisphenol added, improve moldability during production, and provide a foam plate with excellent mechanical strength. can do. In addition, the polystyrene resin extruded foam plate of the present invention has an average cell diameter in the thickness direction of 0.05 to 0.25 mm, an apparent density of 22 to 60 kg / m ³ , flame retardancy, heat insulation, light weight, and dimensional stability. The property is also excellent. Further, in the method of the present invention, by combining with a specific foaming agent, a foamed plate using a foaming agent having an ozone depletion coefficient of 0 and a global warming potential as low as possible can be provided.

  The method for producing a polystyrene resin extruded foam plate (hereinafter referred to as an extruded foam plate) of the present invention is obtained by flattening a foamable polystyrene resin melt prepared in an extruder in the same manner as in the conventional polystyrene resin extruded foam. Extruded into a low-pressure region through a die from a high-pressure extruder and foamed, and a molding die placed at the outlet of the die (parallel or two polytetrafluoroethylenes installed so as to gradually expand from the inlet to the outlet) A method of obtaining a foamed plate by passing a forming tool such as a member formed of a plate made of a fluororesin such as ethylene resin (hereinafter referred to as a guider) or a molding roll can be employed. The foamable polystyrene resin melt is prepared by supplying a polystyrene resin into an extruder and melting it, adding a foaming agent, a flame retardant, and other additives as necessary, and kneading them. Depending on the type of resin, whether or not a fluidity improver is added, the type and amount of fluidity improver, and the amount of mixed foaming agent added and the components of the foaming agent, etc. In general, it is cooled to 110 to 130 ° C.), adjusted to a melt viscosity suitable for foaming, and then extruded from the extruder to be foamed.

The method of the present invention mainly uses a flame retardant selected from any of the following (i) to (v) without using HBCD as a flame retardant added to the above expandable polystyrene resin melt. It is a feature.
(I) brominated isocyanurate (ii) brominated isocyanurate, diphenylalkane and / or diphenylalkene (iii) brominated bisphenol, diphenylalkane and / or diphenylalkene (iv) brominated isocyanurate and brominated bisphenol ( v) Brominated isocyanurates, brominated bisphenols, diphenylalkanes and / or diphenylalkenes

  Examples of the polystyrene resin supplied to the extruder in the present invention include a styrene homopolymer, a styrene-acrylic acid copolymer containing styrene as a main component, a styrene-methyl acrylate copolymer, and a styrene-ethyl acrylate copolymer. Polymer, styrene-methacrylic acid copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-maleic anhydride copolymer, styrene-polyphenylene ether copolymer, styrene-butadiene copolymer Polymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-methylstyrene copolymer, styrene-dimethylstyrene copolymer, styrene-ethylstyrene copolymer, styrene-diethylstyrene copolymer Etc. The styrene component content in the styrene-based copolymer is preferably 50 mol% or more, particularly preferably 80 mol% or more. Moreover, as said polystyrene-type resin, what mixed the other polymer may be used in the range in which the objective of this invention, an effect | action, and an effect are achieved. Other polymers include polyethylene resins, polypropylene resins, styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-butadiene-styrene block copolymer hydrogenated products, styrene- Examples include hydrogenated isoprene-styrene block copolymer, styrene-ethylene copolymer, and the like, and may be mixed depending on the purpose within a range of generally less than 50% by weight, further less than 30% by weight, particularly less than 10% by weight. it can. The above-mentioned polystyrene resin has a melt flow rate (hereinafter referred to as MFR) of 0.5 to 30 g / 10 minutes, further 1 to 10 g / 10 minutes (however, measured under test condition 8 of method A of JIS K7210-1976) Used in the range of MFR), it is excellent in extrusion foaming moldability when producing an extruded foam plate, and an extruded foam plate excellent in appearance, foamability, etc. is obtained, and in mechanical strength is also excellent. It is preferable from the point that the product is obtained.

  Next, the flame retardant used in the present invention will be described in detail. In the present invention, the above-mentioned drawbacks due to the low decomposition start temperature of HBCD can be improved, and the sufficient effect of satisfying the flammability standard of the extruded polystyrene foam heat insulating plate described in JIS A 9511 (1995) also in flame retardancy. New flame retardants are used. There are several methods for resin flame retardant processing, but especially in the case of resin foams having a cell structure, flame retardant processing is performed due to factors such as gas in the cell and an increase in the surface area of the resin due to the cell structure. Making it more difficult. In the polystyrene resin extruded foam plate, since it was obtained by using CFC, which is a conventional non-combustible gas, as a foaming agent, it is not necessary to consider the influence of gas in the bubbles for flame retardancy, As long as HBCD is used as a flame retardant, considering the increase in the resin surface area due to the cell structure, flame retardant processing has not been so difficult. In addition, CFC and HCFC foaming agents have a relatively wide temperature range suitable for extrusion of polystyrene resin, which is necessary to produce polystyrene resin foam plates with suitable apparent density, and the stability of extrusion due to decomposition of flame retardant during extrusion foaming. The influence of fluctuations in extrusion pressure on the properties was not particularly problematic. For these reasons, when producing polystyrene resin extruded foam plates, HBCD has been employed as a flame retardant simply because of its superiority in flame retardancy. However, when HFC or saturated hydrocarbons that do not cause ozone layer destruction are used as blowing agents, the stability of extrusion foaming may be impaired, especially when flammable saturated hydrocarbons are used. Since a large amount of HBCD needs to be added to obtain excellent flame retardancy, the stability of extrusion foaming may be significantly impaired, and the properties of the obtained foam may be impaired.

  This invention solves said problem by using the thing containing the brominated flame retardant which consists of brominated isocyanurate and / or brominated bisphenol as a flame retardant.

  The brominated isocyanurate used as a flame retardant in the present invention is a brominated product of isocyanuric acid or an isocyanuric acid derivative represented by the following formula (1). Since the brominated isocyanurate has an isocyanurate skeleton in the structural formula, it is possible to efficiently generate hydrogen bromide exhibiting a flame retardant effect at the polystyrene-based resin decomposition temperature. Hydrogen bromide generated from the flame retardant reacts with the active radicals generated by the decomposition of the polystyrene-based resin, reducing the amount thereof, stopping the chain reaction of active radical generation that continues combustion, and bromine gas It also becomes possible to exert excellent flame retardancy due to the effect of shielding by.

［式中、Ｒ^１，Ｒ^２，Ｒ^３は、水素原子、炭素数１〜８のアルキル基、−Ｙ−Ｘで表される有機基（式中、Ｙは炭素数１〜６のアルキレン基、Ｘはエポキシ基、カルボキシル基、水酸基、アミノ基、フェニル基である）、およびフェニル基の中から選択されるもの、および、これらの原子及び原子団のうち、少なくとも１つの水素原子が臭素原子に置換されているものである。但し、Ｒ^１，Ｒ^２，Ｒ^３のうち少なくとも１つは、前記原子及び原子団のうち少なくとも１つの水素原子が臭素原子に置換されているものとする。尚、Ｒ^１，Ｒ^２，Ｒ^３の原子及び原子団は相互に異なるものであっても同じものであってもよい。］

[Wherein R ¹ , R ² and R ³ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by —Y—X (wherein Y is an alkylene group having 1 to 6 carbon atoms, , X is an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group), and a group selected from phenyl groups, and at least one of these atoms and atomic groups is a bromine atom Is replaced. However, in at least one of R ¹ , R ² , and R ³ , at least one hydrogen atom of the atoms and atomic groups is substituted with a bromine atom. The atoms and atomic groups of R ¹ , R ² and R ³ may be different from each other or the same. ]

  Specific examples of the brominated isocyanurate include mono (2,3-dibromopropyl) isocyanurate, di (2,3-dibromopropyl) isocyanurate, tris (2,3-dibromopropyl) isocyanurate, mono (2 , 3,4-tribromobutyl) isocyanurate, di (2,3,4-tribromobutyl) isocyanurate, tris (2,3,4-tribromobutyl) isocyanurate and the like. Among the above brominated isocyanurates, tris (2,3-dibromopropyl) isocyanurate has good compatibility with polystyrene resins, has a decomposition initiation temperature of 250 to 265 ° C., and a melting point of 100. Since it is -110 degreeC, the handling at the time of foaming board manufacture is easy, there is little possibility of decomposing | disassembling at the time of kneading | mixing with a polystyrene-type resin, and since an extremely high flame-retardant effect is expressed easily, it is preferable. In addition, as a brominated isocyanurate in this invention, the thing of 1 type (s) or 2 or more types among what is shown by the said Formula (1) can be added to a polystyrene-type resin. Further, brominated isocyanurate and other flame retardants such as antimony trioxide (flame retardants other than brominated bisphenol, diphenylalkane and diphenylalkene) can be used in combination and added to the polystyrene resin. The brominated isocyanurate (flame retardant (i)) is blended in a proportion of 0.5 to 10 parts by weight with respect to 100 parts by weight of the polystyrene resin. As a method of blending the flame retardant into the polystyrene resin, a method of supplying a predetermined ratio of the flame retardant together with the polystyrene resin to a supply unit provided upstream of the extruder and kneading in the extruder is adopted. Can do. In addition, a method of supplying a flame retardant into the molten polystyrene resin from a flame retardant supply unit provided in the middle of the extruder can also be employed. When supplying a flame retardant to an extruder, a method of supplying a dry blend of a flame retardant and a polystyrene resin to the extruder, a melt kneaded material obtained by kneading the flame retardant and a polystyrene resin with a kneader, etc. It is possible to adopt a method of supplying a flame retardant master batch and a method of producing a flame retardant master batch and supplying it to an extruder. In particular, from the viewpoint of dispersibility, a method of producing a flame retardant master batch and supplying it to an extruder can be adopted. preferable. The flame retardant master batch is preferably adjusted so that the flame retardant is contained in an amount of 10 to 70% by weight using a polystyrene resin having an MFR of 0.5 to 30 g / 10 min in the base resin.

  In the present invention, brominated bisphenol is a brominated product of bisphenol A or a bisphenol A derivative represented by the following formula (2). Since the brominated bisphenol has a bisphenol skeleton in the structural formula, it is possible to efficiently generate hydrogen bromide that exhibits a flame retardant effect at the polystyrene resin decomposition temperature, and from the flame retardant during combustion. The generated hydrogen bromide reacts with the active radicals generated during the decomposition of the polystyrene-based resin, reducing the amount thereof, stopping the chain reaction of active radical generation that continues combustion, and shielding effect by bromine gas Can also exert excellent flame retardancy.

［式中，Ｒ^４，Ｒ^５は、水素原子、炭素数１〜８のアルキル基、−Ｙ−Ｘで表される有機基（式中，Ｙは炭素数１〜６のアルキレン基、Ｘはエポキシ基、カルボキシル基、水酸基、アミノ基、フェニル基である）、およびフェニル基のうちから選ばれるもの、および、これらの原子及び原子団のうち、少なくとも１つの水素原子が臭素原子に置換されているものである。尚、Ｒ^４，Ｒ^５の原子及び原子団は相互に異なるものであっても同じものであってもよい。］

[Wherein R ⁴ and R ⁵ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an organic group represented by —Y—X (wherein Y is an alkylene group having 1 to 6 carbon atoms, X is An epoxy group, a carboxyl group, a hydroxyl group, an amino group, a phenyl group), and a group selected from phenyl groups, and at least one hydrogen atom among these atoms and atomic groups is substituted with a bromine atom It is what. The atoms and atomic groups of R ⁴ and R ⁵ may be different from each other or the same. ]

  Specific examples of the brominated bisphenol represented by the formula (2) include tetrabromobisphenol A, tetrabromobisphenol A bis (2,3-dibromopropyl ether), tetrabromobisphenol A bis (2-bromoethyl ether), tetra Bromobisphenol A bis (2-bromoethyl ether) oligomer, tetrabromobisphenol A bis (1-bromopropyl ether), tetrabromobisphenol A bis (allyl ether), tetrabromobisphenol A bis (2-hydroxyethyl ether), tetra Bromobisphenol A diglycidyl ether, tribromophenol adduct of tetrabromobisphenol A diglycidyl ether, tetrabromobisphenol A polycarbonate oligomer, tetrabutyl Mo epoxy adduct of bisphenol A oligomers and the like. Among the above brominated bisphenols, tetrabromobisphenol A bis (2,3-dibromopropyl ether), tetrabromobisphenol A bis (2-bromoethyl ether), tetrabromobisphenol A bis (2-Bromoethyl ether) oligomer has good compatibility with polystyrene resin, decomposition start temperature is 275-310 ° C., melting point is 105-130 ° C., easy handling at the time of foam plate production, polystyrene type The possibility of decomposing at the time of kneading with the resin is small, and the flame retarding effect is also high and is easy to express. The brominated bisphenol in the present invention may be one or more of those represented by the above formula (2).

  In the present invention, the brominated isocyanurate represented by the above formula (1) (flame retardant (i)) can be used alone as the flame retardant, but the brominated isocyanurate and diphenylalkane and / or diphenylalkene described later. A flame retardant (flame retardant (ii)) can also be used. The brominated bisphenol represented by the formula (2) is a flame retardant (flame retardant (iv)) used in combination with the brominated isocyanurate, or a flame retardant (flame retardant (combined with diphenylalkane and / or diphenyl alkene) described later. iii)) or used as a flame retardant (flame retardant (v)) in which brominated isocyanurate and diphenylalkane and / or diphenylalkene are used in combination. The above flame retardants (ii) to (v) are also used in combination with another flame retardant such as antimony trioxide (a flame retardant other than brominated isocyanurate, brominated bisphenol, diphenylalkane and diphenylalkene). Can be added. The flame retardants (flame retardants (ii) to (v)) of brominated bisphenol and brominated isocyanurate, diphenylalkane and / or diphenylalkene are also 0.5 to 10 weights with respect to 100 parts by weight of polystyrene resin. Part (which means a blending ratio of only the flame retardants (ii) to (v) even when another flame retardant is further used in combination). For the blending method of the flame retardant into the polystyrene-based resin, the same method as that described in detail for the brominated isocyanurate can be adopted. Other flame retardants that can be used in combination with flame retardants (i) to (v) include antimony trioxide, diantimony pentoxide, zinc stannate, triallyl isocyanurate, melamine cyanurate, melamine, melam, melem, etc. Nitrogen-containing cyclic compounds, silicone compounds, inorganic compounds such as boron oxide, phosphorus compounds, and the like.

  In the present invention, the diphenylalkane used by mixing with the brominated isocyanurate or brominated bisphenol is a compound represented by the following formula (3), and the diphenylalkene is a compound represented by the following formula (4). Formula (4) shows an example of the structure of diphenylalkene, and isomers having different alkene double bond positions in the structure shown in Formula (4) can also be used in the present invention.

[Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ^９は、炭素数１〜３のアルキル基であって、相互に異なるものであっても同じものであってもよい。]

[R ⁶ , R ⁷ , R ⁸ , and R ⁹ are alkyl groups having 1 to 3 carbon atoms, and may be different or the same. ]

[Ｒ^１０、Ｒ^１１は、炭素数１〜３のアルキル基であって、相互に異なるものであっても同じものであってもよい。]

[R ¹⁰ and R ¹¹ are alkyl groups having 1 to 3 carbon atoms, and may be different or the same. ]

  Specific examples of the diphenylalkane represented by the above formula (3) and the diphenylalkene represented by the formula (4) and the like include 2,3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3. -Diphenylbutane, 3,4-dimethyl-3,4-diphenylhexane, 3,4-diethyl-3,4-diphenylhexane, 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl- 4-ethyl-1-pentene etc. are mentioned. Of the diphenylalkanes and diphenylalkenes described above, 2,4-diphenyl-4-methyl-1-pentene and 2,3-dimethyl-2,3-diphenylbutane are particularly compatible with polystyrene resins. From the point that the decomposition start temperature is 250 to 300 ° C., it is preferable because it is easy to handle at the time of foam plate production, has a low possibility of being decomposed at the time of kneading with polystyrene resin, and has a high flame retardant effect. In the present invention, diphenylalkane can be one or more of those represented by the above formula (3), and diphenylalkene can be used among those represented by the above formula (4). Species or two or more types can be used.

  The above-mentioned diphenylalkane and diphenylalkene have the effect of improving the flame retardant effect of the brominated flame retardant when used in combination with the brominated flame retardant, and as a result, the effect of reducing the amount of brominated flame retardant added. The reason for this is not clear, but radicals generated by the decomposition of diphenylalkane or diphenylalkene draw a hydrogen atom from the polystyrene resin to generate a polymer radical, and form a carbonized film by bonding of the polymer radicals. It is assumed that it plays the role of a flame retardant aid that acts as a promoting substance. By reducing the amount of brominated flame retardant added, the pressure drop during the production of extruded foam plates can be reduced, and the extrusion stability such as die pressure and foaming agent injection pressure can be further improved. It is possible to obtain a foamed plate having a uniform appearance and good appearance. Diphenylalkane and / or diphenylalkene used in combination with a brominated flame retardant comprising brominated bisphenol and / or brominated isocyanurate is a total amount of diphenylalkane and diphenylalkene with respect to 100 parts by weight of the brominated flame retardant. Is 0.3 to 300 parts by weight, preferably 0.5 to 250 parts by weight, and more preferably 1 to 200 parts by weight. If the total amount of diphenylalkane and diphenylalkene added to the brominated flame retardant is less than 0.3 parts by weight, the effect of reducing the added amount of brominated flame retardant is small, and as a result, more brominated flame retardant must be added. It may be necessary. When the total amount of diphenylalkane and diphenylalkene exceeds 300 parts by weight, the effect of reducing the amount of brominated flame retardant added reaches its peak. Moreover, it is preferable to mix | blend diphenylalkane and diphenylalkene so that these addition amount may become a ratio of 0.03-2 weight part with respect to 100 weight part of polystyrene resins. The flame retardant comprising the brominated flame retardant and diphenylalkane and / or diphenyl alkene is the same as the method described in detail for the brominated isocyanurate for the blending method of the flame retardant into the polystyrene resin. A method etc. can be adopted.

  In the present invention, 0.5 to 10 parts by weight of any of the flame retardants (i) to (v) described above is added to 100 parts by weight of polystyrene, preferably 0.8 to 8 parts by weight, Preferably, it is 0.8-6 weight part. When the amount of the flame retardant added is less than 0.5 parts by weight, it is difficult to obtain a sufficient flame retardant effect. On the other hand, when the amount of the flame retardant added exceeds 10 parts by weight, the fluidity is excessively improved, and internal foaming is likely to occur in the die during production, so that a foamed plate having a good surface state may not be obtained. In addition, mechanical properties such as compression and bending of the resulting foamed plate may be lowered.

  The polystyrene resin extruded foam plate obtained by the method of the present invention is excellent in flame retardancy by containing the specific flame retardant. However, the use of the specific flame retardant, the cell structure of the foam plate described later, in the foam plate Due to the synergistic effect of the combination with the remaining foaming agent composition, it is possible to obtain a polystyrene resin extruded foam board that satisfies the flammability standard of the extruded polystyrene foam heat insulating board described in JIS A 9511 (1995).

  Examples of the blowing agent used in the present invention include well-known physical blowing agents such as methyl chloride, propane, butane, HFC, and water. Further, a well-known chemical foaming agent such as azodicarbonamide can be used in combination with a bubble adjusting function for adjusting the bubble diameter of the foam plate to be small.

  The physical foaming agent is supplied into the extruder and kneaded with the molten polystyrene resin by a known method such as press-fitting from the middle of the extruder to form a foamable molten resin. In addition, about a chemical foaming agent, the method of supplying with a polystyrene-type resin to the supply part provided in the upstream of the extruder, and knead | mixing with a molten polystyrene resin in an extruder can be employ | adopted.

  Among the physical blowing agents that can be used in the present invention, preferred are saturated hydrocarbons having 3 to 5 carbon atoms such as propane, normal butane, isobutane, normal pentane, isopentane, and cyclopentane, 1,1,1,2 -HFC such as tetrafluoroethane, 1,1-difluoroethane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane, dimethyl ether, diethyl ether, methyl ethyl ether Inorganic gases such as ethers such as ether, lower alcohols such as methanol and ethanol, alkyl chlorides having 1 or 2 carbon atoms such as methyl chloride and ethyl chloride, carbon dioxide, nitrogen and water. In order to obtain a foam plate having a low apparent density, among the above physical foaming agents, a saturated hydrocarbon having 3 to 5 carbon atoms that has good solubility in polystyrene resins and does not have an extremely large plasticizing effect on polystyrene resins. Is preferred. Furthermore, in order to obtain a foamed plate exhibiting high heat insulation properties, those having good solubility in polystyrene resin and a low apparent density are obtained, and isobutane and isopentane remaining in the foamed plate for a long time are preferable. However, although a saturated hydrocarbon having 3 to 5 carbon atoms is suitable for obtaining a foam plate having a low apparent density, it is a flammable gas and is not preferable in terms of flame retardancy. Furthermore, isobutane and isopentane are suitable for obtaining a foam plate having high heat insulation properties, but are not flammable gases and remain in the foam plate for a long time. Absent. Therefore, in the present invention, a single or two or more foaming agents selected from the group consisting of alkyl chloride having 1 or 2 carbon atoms, dimethyl ether, diethyl ether, methyl ethyl ether, methanol, ethanol, carbon dioxide, and water, which are rich in foaming power. A foaming agent composed of (hereinafter referred to as an early escape foaming agent) and a saturated hydrocarbon having 3 to 5 carbon atoms is preferably used. The reason why it is preferable to use the above-mentioned early-dissipating foaming agent is that the early-dissipating foaming agent dissipates from the foam immediately after extrusion foaming or at an early stage after extrusion foaming. This is because it contributes to foaming and causes a decrease in the apparent density of the foamed plate, and also contributes to a reduction in the amount of saturated hydrocarbons having 3 to 5 carbon atoms, which is a combustible gas, and improves flame retardancy. . By this, the heat insulation performance and flame retardance performance of the obtained foam board can be stabilized at an early stage.

  The amount of the foaming agent added varies depending on the type of foaming agent, the apparent density of the desired foamed plate, the type of polystyrene resin, etc., and is difficult to specify. Generally 0.7 to 2.5 moles per 1 kg of resin (in the case where a plurality of physical foaming agents are used in combination, the total number of moles of constituent foaming agents), preferably 0.85 to 2.0 moles (note that When a plurality of physical foaming agents are used in combination, the total number of moles of the constituent foaming agent is added). Moreover, when using a chemical foaming agent and a physical foaming agent together, the addition amount of a physical foaming agent is added in the substantially same range as the case where only a physical foaming agent is added, and a chemical foaming agent is added to 100 weight part of polystyrene resins. On the other hand, it is added in the range of about 0.1 to 10 parts by weight.

  In the production method of the present invention, in addition to the flame retardant, a foam regulator can be added to the foamable molten resin composition in order to adjust the average cell diameter of the extruded foam plate. Examples of the air conditioner include inorganic substances such as talc, kaolin, mica, silica, calcium carbonate, barium sulfate, titanium oxide, clay, aluminum oxide, bentonite, and diatomaceous earth. Further, in the present invention, two or more kinds of the air bubble adjusting agents can be used in combination. Among the various bubble regulators, talc is preferably used for reasons such as easy adjustment of the bubble diameter of the foamed plate obtained and easy reduction of the bubble diameter and the expectation of an improvement in flame retardancy. Talc having a fine average particle size (50% particle size by light transmission centrifugal sedimentation) of 0.5 to 10 μm is preferable. Moreover, it is preferable that the addition amount of this bubble regulator is 0.1-7.5 weight part with respect to 100 weight part of polystyrene-type resin, Furthermore, it is added in the ratio of 0.5-5 weight part.

  In the production method of the present invention, various additives such as a colorant, a heat stabilizer, and a filler are appropriately added in addition to the above-mentioned bubble regulator and flame retardant, as long as the purpose and effect of the present invention are not hindered. Can do. In addition, the addition method similar to the addition method of the said flame retardant can be employ | adopted as the addition method in the extrusion foaming process of various additives, such as the said bubble regulator and a coloring agent.

  Hereinafter, the polystyrene resin extruded foam plate of the present invention will be described. The polystyrene resin extruded foam plate of the present invention includes a foam plate (hereinafter referred to as the first invention foam plate) containing a specific amount of isobutane in the foam plate and a specific amount of 1 in the foam plate. , 1,1,2-tetrafluoroethane and a foamed plate containing a saturated hydrocarbon having 3 to 5 carbon atoms (hereinafter referred to as the second invention foamed plate).

The apparent density of the polystyrene resin extruded foam plate of the present invention is 22 to 60 kg / m ³ , preferably 30 to 50 kg / m ³ . When the apparent density is less than 22 kg / m ^3, it is quite difficult to produce an extruded foam plate having such an apparent density, and the conventional foam insulation is also used in the mechanical properties of the obtained extruded foam plate. Since it becomes insufficient as compared with the plate, the usable applications are limited. On the other hand, when the apparent density exceeds 60 kg / m ³ , it is difficult to exert sufficient heat insulation unless the thickness is increased more than necessary, which may be insufficient in terms of light weight. Moreover, the thickness of the polystyrene-type resin extrusion foam board of this invention is 10-150 mm, Preferably it is a 20-100 mm thing. If the thickness exceeds 150 mm, the bubble diameter in the thickness direction tends to be large, so there is a possibility that sufficient heat insulation may not be ensured. In addition, a large extruder is required for stable production of foamed plates. Necessary. On the other hand, when the thickness is less than 10 mm, there is a possibility that the mechanical strength and heat insulation properties are insufficient due to difficulty in production.

  In the foamed board of the first invention of the present invention, the isobutane content in the foamed board is 0.40 to 0.90 mole, preferably 0.45 to 0.75 mole, more preferably 0, per 1 kg of the foamed board. .50 to 0.65 mol. When the content of isobutane is within the above range, a highly heat insulating heat insulating material is obtained. Specifically, the thermal conductivity of the three types of extruded polystyrene foam heat insulating plates described in JIS A9511 (1995) is 0.028 W / mK or less by combining the structure of the average cell diameter in the thickness direction of the foamed plate described later. It is possible to obtain an extruded foam plate. When the isobutane content is less than 0.40 mol, it is difficult to obtain sufficiently high heat insulation, and when the isobutane content exceeds 0.90 mol, sufficient flame retardancy as a building material can be obtained. There is a possibility that it cannot be done.

  In the second invention foamed plate of the present invention, the 1,1,1,2-tetrafluoroethane content in the foamed plate is 0.10 to 0.80 mole per 1 kg of the foamed plate, saturated with 3 to 5 carbon atoms. The content of the hydrocarbon compound is 0 to 0.80 mol per kg of the foamed plate. When the content of the foaming agent is within the above range, a highly heat-insulating heat insulating material is obtained. Specifically, the thermal conductivity of the three types of extruded polystyrene foam heat insulating plates described in JIS A9511 (1995) is 0.028 W / mK or less by combining the structure of the average cell diameter in the thickness direction of the foamed plate described later. It is possible to obtain an extruded foam plate. The content of 1,1,1,2-tetrafluoroethane in the foamed plate is preferably 0.15 to 0.70 mol, more preferably 0.20 to 0.60 mol per kg of the foamed plate. The content of the saturated hydrocarbon compound having 3 to 5 carbon atoms is preferably 0.10 to 0.70 mol, more preferably 0.15 to 0.65 mol, per 1 kg of the foam plate. When the content of 1,1,1,2-tetrafluoroethane is less than 0.10 mol, it becomes difficult to obtain a sufficiently high heat insulating property, and the content of 1,1,1,2-tetrafluoroethane When the amount exceeds 0.80 mol, internal foaming is likely to occur in the die at the time of production, and there is a possibility that a foamed plate having a good surface state cannot be obtained. Moreover, when content of a C3-C5 saturated hydrocarbon compound exceeds 0.80 mol, there exists a possibility that flame retardance sufficient as a building material cannot be obtained.

  The content of the blowing agent in the present specification is measured using a gas chromatograph. Specifically, a sample cut out from the center of the extruded foam plate is placed in a sample bottle with a lid containing toluene, and after the lid is closed, the sample is thoroughly stirred to remove the foaming agent in the extruded foam plate from toluene. The content of isobutane, 1,1,1,2-tetrafluoroethane, etc. contained in the foam plate is obtained by measuring the sample dissolved in the sample and performing gas chromatography analysis on the sample and quantifying it by an internal standard method. Can be requested.

  Adjustment of the foaming agent content in the foamed plate of the present invention is carried out by adjusting the solubility of the foaming agent in the polystyrene resin and the gas permeation rate when supplying the physical foaming agent to the extruder in the production method of the present invention described above. This is done by determining the supply amount in consideration. For example, foaming agents such as isobutane and 1,1,1,2-tetrafluoroethane have a high solubility in polystyrene resin and a slow gas permeation rate, so the amount required to maintain heat insulation. Is supplied to the extruder, it becomes the foaming agent content in the foamed plate from which substantially the entire amount of the supplied foaming agent is obtained. In order to adjust the apparent density of the foam plate with little influence on the adjustment of the foaming agent content in the foam plate, the gas permeation rate of the polystyrene resin such as water, carbon dioxide, dimethyl ether, etc. A fast foaming agent (early dissipating foaming agent) is selected as the physical foaming agent. Therefore, the foamed plate of the present invention in which the content of a specific foaming agent is adjusted and the apparent density is adjusted is a combination of a foaming agent having a high gas permeation rate and a foaming agent having a slow gas permeation rate with respect to polystyrene resin. You can get it.

The foamed plate of the present invention has an average cell diameter in the thickness direction of 0.05 to 0.25 mm, preferably 0.06 to 0.20 mm, more preferably 0.06 to 0.18 mm. It is. When the average cell diameter is within the above range, it is possible to obtain a foamed plate having higher heat insulation properties without changing the foaming agent composition. If the bubble diameter is less than 0.05 mm, it is difficult to obtain a foam plate having a large thickness and a small apparent density. On the other hand, when it exceeds 0.25 mm, there is a possibility that a foamed plate having a desired heat insulating property cannot be obtained. In addition, in order to obtain a foam plate having a high thermal insulation property such that the thermal conductivity of the three types of extruded polystyrene foam heat insulating plates described in JIS A9511 (1995) is 0.028 W / mK or less, In addition to satisfying the conditions, it is important to satisfy the conditions of the isobutane content and the 1,1,1,2-tetrafluoroethane content in the foamed plate as described above. This leads to a reduction in the amount of HFC used and a reduction in the amount of combustible gas, and brings about the effects of improving the suitability for each environment and improving the flame retardancy. The measurement method of the average bubble diameter in this specification is as follows. The average cell diameter in the thickness direction of the foam plate (D _T : mm) and the average cell size in the width direction of the foam plate (D _W : mm) are the vertical cross section in the width direction of the foam plate (vertical cross section perpendicular to the extrusion direction of the foam plate). The average cell diameter in the longitudinal direction of the foamed plate (D _L : mm) is the vertical cross section in the longitudinal direction of the foamed plate (vertical cross section that bisects the foamed plate in the width direction and perpendicular to the width direction of the foamed plate). Use a microscope or the like to enlarge and project on a screen or monitor, draw a straight line in the direction to be measured on the projected image, count the number of bubbles intersecting the straight line, and calculate the length of the straight line (however, this length Is not the length of the straight line on the magnified projection image, but the length of the true straight line taking into account the magnification of the projected image)) divided by the number of counted bubbles and the average in each direction Obtain the bubble diameter. However, in the measurement of the average bubble diameter (D _T : mm) in the thickness direction, a straight line extending over the entire thickness in the thickness direction is drawn at a total of three locations in the center and both ends of the vertical cross section in the width direction. The average diameter of the bubbles existing on each straight line (the length of the straight line / the number of bubbles crossing the straight line) is obtained from the number of bubbles intersecting with each other, and the arithmetic average value of the three average diameters obtained is determined in the thickness direction. The average bubble diameter (D _T : mm). The average bubble diameter (D _W : mm) in the width direction is a 3000 μm long straight line in the width direction at a position where the total three foam plates at the center and both ends of the width direction are divided into two in the thickness direction. The average diameter of the bubbles existing on each straight line (3000 μm / (number of bubbles intersecting the straight line-1)) is obtained from the straight line having a length of 3000 μm and (number of bubbles intersecting the straight line-1). The arithmetic average value of the obtained average diameters at the three locations is defined as the average bubble diameter in the width direction (D _W : mm). The average bubble diameter in the longitudinal direction (D _L : mm) is a longitudinal line of 3000 μm in the longitudinal direction at a position where the total three foam plates at the center and both ends of the longitudinal section are equally divided in the thickness direction. The average diameter of the bubbles existing on each straight line (3000 μm / (number of bubbles intersecting the straight line-1)) is obtained from the straight line having a length of 3000 μm and (number of bubbles intersecting the straight line-1). The arithmetic average value of the obtained average diameters at the three locations is defined as the average bubble diameter in the longitudinal direction (D _L : mm). The average cell diameter in the horizontal direction of the foam plate _{(D H:} mm) is the arithmetic mean value of _{D W} and _{D L.}

Furthermore, in the extruded foam plate of the present invention, the bubble deformation rate is preferably 0.7 to 2.0. The cell strain rate, the D _T obtained by the measuring method means a value calculated by dividing the _{D H (D T / D H} ), small enough bubbles flat than bubbles deformation rate 1 The larger the value is, the longer the image is. If the bubble deformation ratio is less than 0.7, the compression strength may be reduced because the bubbles are flat, and the flat bubbles are more likely to return to a circle, so the dimensional stability of the extruded foam plate is also reduced. There is a fear. If the bubble deformation rate exceeds 2.0, the number of bubbles in the thickness direction decreases, and there is a possibility that the desired high heat insulation property cannot be obtained. From such a viewpoint, the bubble deformation rate is preferably 0.8 to 1.5, and more preferably 0.8 to 1.2. When the bubble deformation rate is within the above range, a foamed plate having high heat insulation can be obtained. Examples of the method for obtaining the foam plate of the present invention in which the average cell diameter is adjusted to be small as described above include the method of adding the above-mentioned cell regulator, but simply increasing the amount of the cell regulator added. Therefore, even if the bubble diameter is adjusted to be small, the open cell ratio of the foamed plate increases, and as a result, it cannot be easily obtained that the desired high heat insulating property is exhibited. Therefore, for example, in consideration of the relationship between the MFR and the melt viscosity of the polystyrene resin, the foam adjustment is performed by selecting a polystyrene resin that does not cause the above-mentioned open cell formation and the MFR does not become so small even if the melt viscosity is high. It is possible to obtain a foamed plate having a small average cell diameter by increasing the amount of the agent added, or by using an inorganic physical foaming agent such as carbon dioxide as a physical foaming agent avoiding the addition of an excessive amount of air bubble regulator. it can. In addition, the said bubble deformation rate of a foamed board can be adjusted with the method of Japanese Patent Application 2001-183249, for example.

  Since the extruded foam board of the present invention is mainly used as a heat insulating board, it is particularly preferable that it satisfies the flammability standard for the extruded polystyrene foam heat insulating board described in JIS A9511 (1995). That is, when the flammability was measured according to 4.13.1 “Measurement Method A” described in JIS A9511 (1995), the flame disappeared within 3 seconds, there was no residue, and the combustion limit support line was It is preferable that it does not burn over. Such an extruded foam board has the safety required as an extruded polystyrene foam heat insulating board for building materials because the possibility of fire burning is small even when ignited.

  As described above, the extruded foam plate of the present invention preferably has a closed cell ratio of 90% or more, more preferably 93% or more from the viewpoint of improving heat insulation and further improving mechanical strength. The higher the closed cell ratio, the higher the heat insulation performance and the longer it can be maintained. In the present specification, the closed cell ratio of the foamed plate is measured using an air-comparing hydrometer 930 type manufactured by Toshiba Beckman Co., Ltd. according to the procedure C of ASTM-D2856-70 (25 mm × 25 mm × 20 mm from the extruded foamed plate). A cut sample without a molded skin cut to size is stored in a sample cup and measured, but if the thickness is thin and a cut sample of 20 mm cannot be cut in the thickness direction, for example, 25 mm × 25 mm × 10 mm It is sufficient to store and measure two cut samples of the same size in a sample cup at the same time.) Using the true volume Vx of the extruded foamed plate (cut sample), the closed cell ratio S ( %), And an average value of N = 3 was obtained.

(Formula 1)
S (%) = (Vx−W / ρ) × 100 / (VA−W / ρ) (1)
Vx: the true volume (cm ³ ) of the cut sample measured by the above method, which is the sum of the volume of the resin constituting the cut sample of the extruded foam plate and the total volume of bubbles in the closed cell portion in the cut sample Equivalent to.
VA: apparent volume (cm ³ ) of the cut sample calculated from the outer dimensions of the cut sample used for the measurement
W: Total weight of cut sample used for measurement (g)
ρ: Density of resin constituting the extruded foam plate (g / cm ³ )

  Next, the present invention will be described in more detail with specific examples.

Examples 1-6, Comparative Examples 1-3
[Raw materials and blending ratio]
The raw material is based on 100 parts by weight of polystyrene (G330C manufactured by Toyo Styrene Co., Ltd.), and talc masterbatch (69% by weight of the above polystyrene and 30% by weight of high filler # 12 manufactured by Matsumura Sangyo Co., Ltd.) 1.67 parts by weight of a master batch composed of 1% by weight of zinc stearate) and flame retardants in a proportion shown in Table 1 (Examples) and Table 2 (Comparative Examples), butane and methyl chloride as blowing agents The mixture shown in Tables 1 and 2 was used in the amounts shown in Tables 1 and 2 (expressed as the amount of blowing agent injected per 1 kg of polystyrene (mol / kg)). The flame retardant is tris (2,3-dibromopropyl) isocyanurate as brominated isocyanurate and 2,2-bis [4- (2,3-dibromopropoxy) -3,5-dibromo as brominated bisphenol. Phenyl] propane was used, 2,3-dimethyl-2,3-diphenylbutane was used as the diphenylalkane, and 2,4-diphenyl-4-methyl-1-pentene was used as the diphenylalkene. The flame retardants were used by appropriately mixing at the ratios shown in Tables 1 and 2.

[Extrusion equipment]
The extruder has a 65 mm diameter extruder (hereinafter referred to as “first extruder”), a 90 mm diameter extruder (hereinafter referred to as “second extruder”), and a 150 mm diameter extruder (hereinafter referred to as “third extruder”). The mixed foaming agent was press-kneaded into the molten resin near the tip of the first extruder. A die lip having a resin outlet having a width of 115 mm and a gap of 1.5 mm (rectangular cross section) at the tip was used.

[Extrusion conditions]
Using the above apparatus, raw materials such as polystyrene resin are supplied to the first extruder, heated to 220 ° C., melted and kneaded, and mixed foaming agent is injected near the tip of the first extruder to expand the foamable molten resin. The mixture is made into a mixture, and the resin temperature is adjusted so that the resin pressure at the adapter part to which the die lip is attached becomes 40 kgf / cm ² in the subsequent second extruder and third extruder. The resin mixture was extruded from the die lip into the atmosphere. The foamable molten resin mixture extruded from the die lip was compressed while being foamed by passing through the guider while being foamed, and then formed into a plate shape while being filled in a molding apparatus, thereby producing an extruded foamed plate. Tables 1 and 2 show the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent content of the extruded foam plate obtained.

Examples 7-12
Except that the flame retardant and its blending ratio are as shown in Table 3, the blending ratio of the talc masterbatch of the foam regulator is 8.33 parts by weight, and the foaming agent composition is changed to a mixed system of isobutane, dimethyl ether and carbon dioxide. Extruded foam boards were produced in the same manner as in Example 1. Table 3 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, bubble deformation rate, thermal conductivity, combustibility, moldability, and foaming agent content of the obtained extruded foam plate.

Examples 13-16
Example 1 except that the flame retardant and the blending ratio thereof are as shown in Table 4, the blending ratio of the talc masterbatch of the foam regulator is 8.33 parts by weight, and the foaming agent composition is changed to a mixed system of isobutane and methyl chloride. In the same manner, an extruded foam board was produced. Table 4 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent content of the obtained extruded foam plate.

Examples 17-22
The flame retardant and its blending ratio are as shown in Table 5, the blending ratio of the talc masterbatch of the foam regulator is 1.67 parts by weight, and the foaming agent composition is 1,1,1,2-tetrafluoroethane, butane, methyl chloride Extruded foamed plates were produced in the same manner as in Example 1 except that the mixed system was changed. Table 5 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent content of the obtained extruded foam plate.

Examples 23-25
Extruded foam plates were produced in the same manner as in Example 1 except that the flame retardant and the blending ratio thereof were set to Table 6. Table 6 shows the apparent density, thickness, closed cell ratio, average cell diameter in the thickness direction, thermal conductivity, combustibility, moldability, and foaming agent content of the extruded foam plate obtained.

Examples 26-28
Extruded foam plates were produced in the same manner as in Example 7 except that the flame retardant and the blending ratio thereof were changed to Table 7. Table 7 shows the apparent density, thickness, closed cell ratio, average cell diameter in the thickness direction, thermal conductivity, combustibility, moldability, and foaming agent content of the obtained extruded foam plate.

Examples 29-31
Extruded foam plates were produced in the same manner as in Example 13 except that the flame retardant and the blending ratio thereof were set to Table 8. Table 8 shows the apparent density, thickness, closed cell ratio, average cell diameter in the thickness direction, thermal conductivity, combustibility, moldability, and foaming agent content of the obtained extruded foam plate.

Examples 32-34
Extruded foam plates were produced in the same manner as in Example 17 except that the flame retardant and the blending ratio thereof were set to Table 9. Table 9 shows the apparent density, thickness, closed cell ratio, average cell diameter in the thickness direction, thermal conductivity, combustibility, moldability, and foaming agent content of the obtained extruded foam plate.

  The apparent densities in Tables 1 to 9 are values measured based on JIS K7222 (1985).

  The thicknesses in Tables 1 to 9 are values obtained by measuring at three locations at positions that divide the width direction into four equal parts and arithmetically averaging them.

  The thickness direction average bubble diameter and bubble deformation rate in Tables 1 to 9 are values measured by the above methods.

  The closed cell ratio in Tables 1 to 9 is a value measured by the above method using a cut sample having no molded skin cut from an extruded foamed plate to a size of 25 mm × 25 mm × 20 mm.

  The thermal conductivity in Tables 1 to 9 is as described in JIS A 9511 (1995) 4.7 for test pieces having a length of 20 cm, a width of 20 cm, and a thickness of the extruded foamed plate cut out from the extruded foamed plate that passed 4 weeks after production. Based on a flat plate heat flow meter method (two heat flow meter method, average temperature 20 ° C.) described in JIS A 1412 (1994) using a thermal conductivity measuring device “Auto Λ HC-73 type” manufactured by Eihiro Seiki Co., Ltd. Measured.

The flammability in Tables 1 to 9 was measured based on 4.13.1 “Measurement Method A” of JIS A9511 (1995) for an extruded foam plate that had passed 4 weeks after production. In addition, this measurement cut out 10 test pieces with respect to one foamed board (n = 10), and evaluated it with the following evaluation criteria.
A: All specimens disappear within 3 seconds, and the average burning time of 10 specimens is within 2 seconds.
O: All specimens disappear within 3 seconds, and the average burning time of 10 specimens exceeds 2 seconds and is within 3 seconds.
X: The average burning time of 10 test pieces exceeds 3 seconds.

The moldability in Tables 1 to 9 was evaluated according to the following evaluation criteria.
A: A foamed plate with no voids in the cross section, no wrinkles or protrusions on the surface and good appearance, and good stability during production.
X: Voids and / or wrinkles and protrusions are prominently present on the cross section of the foam plate, and the foam plate has a poor appearance, and lacks stability during production.

The measurement of the remaining amount of foaming agent in Tables 1 to 9 (content of foaming agent per 1 kg of foamed plate) is for Shimadzu Corporation, Shimadzu Gas Chromatograph GC-14B, for foamed plates that have passed 4 weeks after extrusion foaming. And cyclopentane as an internal standard was measured based on the above method. The measurement conditions for gas chromatographic analysis are as follows.
Column: manufactured by Shinwa Kako Co., Ltd., Silicon DC550 20%, column length 4.1 m, column inner diameter 3.2 mm, support: Chromosorb AW-DMCS, mesh 60-80
Column temperature: 40 ° C
Inlet temperature: 200 ° C
Carrier gas: Nitrogen Carrier gas speed: 3.5ml / min
Detector: FID detector Temperature: 200 ° C
Quantification: Internal standard method

Claims (3)

In a method for producing a foamed plate having an apparent density of 22 to 60 kg / m ³ and a thickness of 10 to 150 mm by extrusion foaming a foamable molten resin composition obtained by kneading a polystyrene resin, a flame retardant and a foaming agent, The flame retardant is selected from any of the following (i) to (v), and is added at a ratio of 0.5 to 10 parts by weight with respect to 100 parts by weight of the polystyrene resin. A method for producing a polystyrene resin extruded foam plate.
(I) brominated isocyanurate (ii) brominated isocyanurate, diphenylalkane and / or diphenylalkene (iii) brominated bisphenol, diphenylalkane and / or diphenylalkene (iv) brominated isocyanurate and brominated bisphenol ( v) Brominated isocyanurate and brominated bisphenol and diphenylalkane and / or diphenylalkene   The flame retardant is a brominated flame retardant comprising brominated isocyanurate and / or brominated bisphenol, and diphenyl alkane and / or diphenyl alkene, and diphenyl alkane and diphenyl alkene with respect to 100 parts by weight of the brominated flame retardant. Is blended in a ratio of 0.3 to 300 parts by weight in total. The method for producing a polystyrene-based resin extruded foam plate according to claim 1.   The blowing agent is (a) 10 to 90 mol% of a saturated hydrocarbon having 3 to 5 carbon atoms, and (b) an alkyl chloride having 1 or 2 carbon atoms, dimethyl ether, diethyl ether, methyl ethyl ether, methanol, ethanol, water, One or two or more foaming agents selected from carbon dioxide 90 to 10 mol% (however, the total amount of the foaming agent (a) and the foaming agent (b) is 100 mol%) The manufacturing method of the polystyrene-type resin extrusion foamed board of Claim 1 or 2.