JP2012012610A - Method for producing polystyrene-based resin extrusion foamed plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polystyrene-based resin extrusion foamed plate that simultaneously has high flame retardancy and recyclability, and a method for producing a polystyrene-based resin extrusion foamed plate that enables stable production of the extrusion foamed plate.SOLUTION: In the method for producing a foamed plate having apparent density of 20-60 kg/mand a thickness of 10-150 mm by performing extrusion foaming of a foamable molten resin composition which is obtained by kneading of a polystyrene-based resin, a cell regulator, a flame retardant, and a foaming agent, a certain rate of inorganic substances are blended as the cell regulator, a brominated bisphenol ether derivative having special structure and a phosphoric ester are included as the flame retardant, and the brominated bisphenol ether derivative and the phosphoric ester are each blended in a certain rate.

Description

The present invention relates to a method for producing a polystyrene-based 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 flame-retardant polystyrene type excellent in extrusion stability. The present invention relates to a method for producing a resin extruded foam plate.

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 standard of the extruded polystyrene foam heat insulating plate described in JIS A 9511 (1995), a flame retardant is added to the foamed plate. Conventionally, hexabromocyclododecane (hereinafter referred to as HBCD) has been widely used as a flame retardant for polystyrene resin extruded foam plates. Since HBCD has a relatively low decomposition start temperature compared to other main flame retardants, bromine radicals are 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 was used suitably.

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 destruction coefficient has been used in recent years instead of CFC.

However, since the ozone destruction coefficient of HCFC is not zero, there is no danger of destroying the ozone layer. Therefore, a production method of polystyrene resin extruded foam plates using a fluorocarbon (hereinafter referred to as HFC), saturated hydrocarbon, etc., which has zero ozone depletion coefficient and no chlorine atom in the molecule, as a foaming agent is studied. Has been.

However, when a flammable foaming agent such as saturated hydrocarbon is used, in order to give sufficient flame retardancy to the polystyrene resin extruded foam plate, it is more than when it is manufactured using a nonflammable foaming agent such as HFC. Need to add too much HBCD. However, when a large amount of HBCD is added, there is a possibility that stability of extrusion foaming may be remarkably impaired, or physical properties of the obtained foamed plate may be impaired. Although HBCD is a flame retardant excellent in flame retardancy, development of a polystyrene resin extruded foam plate using a flame retardant other than HBCD or suppressing the addition of HBCD as much as possible has been desired.

Then, examination of the polystyrene-type resin extrusion foam board using flame retardants other than HBCD is made. For example, a foam satisfying the test of 4.13.1 “Measurement method A” of JIS A9511 (1995) can be obtained with a relatively small addition amount by using a combination of a brominated isocyanurate-based flame retardant and diphenylalkane. (See Patent Document 1). Tetrabromobisphenol A / diallyl ether is known to exhibit high flame retardancy against polystyrene, and it is used in combination with tetrabromobisphenol A / diallyl ether and a halogenated flame retardant having a higher decomposition temperature. Has been attempted (see, for example, Patent Document 2).

JP 2003-292664 A (paragraph number 0001, etc.) JP 2003-301064 A (paragraph number 0101 etc.)

However, the diphenylalkane described in Patent Document 1 has insufficient heat resistance and leaves room for improvement in recyclability. Further, tetrabromobisphenol A · diallyl ether described in Patent Document 2 has problems such as recyclability and coloration because of its low heat resistance. Such a conventional polystyrene resin extruded foam plate using a flame retardant other than HBCD needs to greatly increase the amount of flame retardant added, which not only increases the cost, but also reduces the mechanical strength and stabilizes the extrusion. There is a risk of deteriorating the performance.

The present invention was made to solve the above-mentioned problems of a flame-retardant polystyrene resin extruded foam plate, and a method for producing a polystyrene resin extruded foam plate having excellent extrusion foam stability and recyclability. The purpose is to provide.

The present invention
(1) Foaming with an apparent density of 20 to 60 kg / m ³ and a thickness of 10 to 150 mm by extrusion foaming a foamable molten resin composition obtained by kneading at least a polystyrene-based resin, a bubble regulator, a flame retardant, and a foaming agent. In the method for producing a plate, the bubble adjusting agent includes an inorganic substance, and the inorganic substance is blended in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight of the polystyrene-based resin. A brominated bisphenol ether derivative having a structure in which bromine is bonded to the tertiary carbon represented by the formula (1) and a phosphoric ester are contained, and the brominated bisphenol ether derivative is added in an amount of 0. 5-5 parts by weight, production of polystyrene resin extruded foam board, characterized in that the phosphate ester is blended in a proportion of 0.1-6 parts by weight Law.

（式中、Ｒは炭素数１〜３のアルキル基、Ａは−Ｃ（ＣＨ_３）_２−，−ＳＯ_２−，−Ｓ−，−Ｏ−，−ＣＯ−，または−ＣＨ_２−）
（２）前記無機物が、タルクであって、該タルクをタルクマスターバッチの形態でポリスチレン系樹脂に配合されることを特徴とする上記（１）に記載のポリスチレン系樹脂押出発泡板の製造方法。
（３）臭素化ビスフェノールエーテル誘導体とリン酸エステルとの重量比（臭素化ビスフェノールエーテル誘導体の配合重量／リン酸エステルの配合重量）が０．３〜３０であることを特徴とする上記（１）又は（２）に記載のポリスチレン系樹脂押出発泡板の製造方法。
（４）前記３級炭素に臭素が結合した構造を有する臭素化ビスフェノールエーテル誘導体が、２，２−ビス〔４−（２，３−ジブロモ−２−メチルプロポキシ）−３，５−ジブロモフェニル〕プロパンであることを特徴とする上記（１）、（２）又は（３）に記載のポリスチレン系樹脂押出発泡板の製造方法。
（５）発泡剤が、（ａ）炭素数３〜５の飽和炭化水素１０〜８０モル％と、（ｂ）炭素数１又は２の塩化アルキル、ジメチルエーテル、ジエチルエーテル、メチルエチルエーテル、メタノール、エタノール、水、二酸化炭素の中から選択される１種又は２種以上の発泡剤９０〜２０モル％〔但し、発泡剤（ａ）と発泡剤（ｂ）との合計量は１００モル％〕からなることを特徴とする前記（１）〜（４）のいずれかに記載のポリスチレン系樹脂押出発泡板の製造方法。
（６）発泡剤が、（ａ）炭素数３〜５の飽和炭化水素５〜７０モル％と、（ｂ）炭素数１又は２の塩化アルキル、ジメチルエーテル、ジエチルエーテル、メチルエチルエーテル、メタノール、エタノール、水、二酸化炭素の中から選択される１種又は２種以上の発泡剤１０〜９０モル％と、（ｃ）１，１，１，２−テトラフルオロエタン０〜７０モル％〔但し、発泡剤（ａ）と発泡剤（ｂ）と発泡剤（ｃ）との合計量は１００モル％〕からなることを特徴とする前記（１）〜（４）のいずれかに記載のポリスチレン系樹脂押出発泡板の製造方法。

(Wherein R is an alkyl group having 1 to 3 carbon atoms, A is —C (CH ₃ ) ₂ —, —SO ₂ —, —S—, —O—, —CO—, or —CH ₂ —).
(2) The method for producing a polystyrene resin extruded foam plate according to (1), wherein the inorganic substance is talc, and the talc is blended with the polystyrene resin in the form of a talc masterbatch.
(3) The above (1), wherein the weight ratio of brominated bisphenol ether derivative to phosphate ester (blended weight of brominated bisphenol ether derivative / blended weight of phosphate ester) is 0.3 to 30 Or the manufacturing method of the polystyrene-type resin extrusion foaming board as described in (2).
(4) The brominated bisphenol ether derivative having a structure in which bromine is bonded to the tertiary carbon is 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl]. The method for producing a polystyrene resin extruded foam plate according to the above (1), (2) or (3), which is propane.
(5) The blowing agent is (a) 10 to 80 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 20 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 foam board in any one of said (1)-(4) characterized by the above-mentioned.
(6) The blowing agent is (a) 5 to 70 mol% of saturated hydrocarbon having 3 to 5 carbon atoms, and (b) alkyl chloride having 1 or 2 carbon atoms, dimethyl ether, diethyl ether, methyl ethyl ether, methanol, ethanol 10 to 90 mol% of one or more blowing agents selected from water, carbon dioxide, and (c) 1,1,1,2-tetrafluoroethane 0 to 70 mol% [however, foaming The total amount of the agent (a), the foaming agent (b), and the foaming agent (c) is 100 mol%]. The polystyrene resin extrusion according to any one of the above (1) to (4), A manufacturing method of a foam board.

According to the invention relating to claim 1 of the present invention, in the method for producing a polystyrene resin extruded foam plate, by using a foamed molten resin composition containing a specific amount of a specific flame retardant, at the time of extrusion foaming Thus, a polystyrene resin extruded foam plate having good foam molding stability and excellent recyclability, flame retardancy and heat insulation can be obtained.

According to the invention relating to claim 3 of the present invention, a polystyrene resin extruded foam plate which is further excellent in flame retardancy and production cost can be obtained.

According to the invention of claim 4 of the present invention, a polystyrene resin extruded foam plate having a high flame retardant effect can be easily obtained. According to the invention according to claim 5 or 6 of the present invention, polystyrene having excellent heat insulation, flame retardancy, recyclability, and environmental suitability without using HFC or HCFC which may destroy the ozone layer. A resin-based extruded foam board is obtained.

According to the invention concerning Claim 5 or 6 of this invention, it has the outstanding heat insulation by containing a specific quantity of combustible foaming agents. Furthermore, despite containing the flammable foaming agent, the content of HBCD is suppressed as much as possible by containing a specific flame retardant other than HBCD, or excellent without containing HBCD. A polystyrene-based resin extruded foam plate that exhibits flame retardancy, manufacturing cost, and recyclability is provided.

In general, there are several methods for resin flame retardant processing, particularly in the case of a resin foam having a cell structure, due to factors such as gas in the cell, an increase in the resin surface area due to the cell structure, Non-foamed flame retardant processing methods cannot simply be applied. Conventionally, HBCD has been used as a flame retardant for the production of polystyrene resin extruded foam plates simply because of its superiority in flame retardancy. When a polystyrene resin extruded foam plate is manufactured, if CFC or the like, which is a non-flammable gas, is used as the foaming agent, it is not necessary to consider the influence of gas in the bubble with respect to flame retardancy. It was enough to consider the increase. When an extruded foam board is produced using a CFC or HCFC foaming agent, the proper temperature range for extrusion foaming of a polystyrene resin necessary for producing a polystyrene resin extruded foam board having a suitable apparent density is relatively wide. The influence of fluctuations in extrusion pressure and the like on extrusion stability due to decomposition of the flame retardant during extrusion foaming is not particularly problematic. As long as HBCD was used as a flame retardant, flame retardant processing was not very difficult.

On the other hand, when HFC, saturated hydrocarbon, or the like that does not cause ozone layer destruction is used as a foaming agent, the possibility that the stability of extrusion foaming is impaired is increased. In particular, when flammable saturated hydrocarbons are used, it is necessary to add a large amount of HBCD in order to obtain sufficient flame retardancy. However, if a large amount of HBCD is added, the stability of extrusion foaming may be significantly impaired. On the other hand, the present invention can solve the above-mentioned problems caused by HBCD by using a flame retardant comprising a brominated bisphenol ether derivative and a phosphate ester represented by the structural formula (1).

The method for producing a polystyrene resin extruded foam plate of the present invention is capable of producing a flame retardant polystyrene resin extruded foam plate by using a foaming agent having a zero ozone depletion coefficient by combining specific foaming agents. it can.

The polystyrene resin extruded foam board obtained by the present invention has an apparent density of 20 to 60 kg / m ³ , a thickness of 10 to 150 mm, and good flame retardancy, heat insulation, light weight, and dimensional stability. It has both excellent physical properties and environmental suitability such as recyclability.

The method for producing a polystyrene resin extruded foam plate (hereinafter simply referred to as an extruded foam plate) of the present invention is a brominated bisphenol ether derivative represented by structural formula (1) as a flame retardant with respect to 100 parts by weight of a polystyrene resin. Is characterized in that 0.5 to 5 parts by weight and 0.1 to 6 parts by weight of a phosphate ester are blended, and the other basic production method is a method for producing a conventional polystyrene resin extruded foam Can be used. Specifically, an expandable polystyrene resin melt prepared by kneading a polystyrene resin, a flame retardant and a foaming agent in an extruder is extruded through a flat die into a low pressure region from the inside of the high pressure extruder, and foamed. Molds arranged at the outlet of the plate [comprised of plates made of two or more upper and lower polytetrafluoroethylene resins installed in parallel or gently so as to expand gradually from the inlet to the outlet (hereinafter referred to as a guider) Etc.] and a method of producing an extruded foam plate by passing a forming tool such as a forming roll.

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, the presence or absence of the addition of a fluidity improver, the type and amount of the fluidity improver, and the addition amount of the mixed foaming agent and the component of the foaming agent, etc. Generally, it is cooled to 110 to 130 ° C.) and adjusted to a melt viscosity suitable for foaming, and then foamed by extrusion from the extruder.

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 unit component content in the styrenic copolymer is preferably 50 mol% or more, particularly preferably 80 mol% or more.

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 (a mixture of two or more selected from the group of ethylene homopolymers and ethylene copolymers having an ethylene unit component content of 50 mol% or more), polypropylene resins (propylene homopolymers). And a mixture of two or more selected from the group of propylene copolymers having a propylene unit component content of 50 mol% or more), polyphenylene ether resin, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer Polymer, styrene-butadiene-styrene block copolymer hydrogenated product, styrene-isoprene-styrene block copolymer hydrogenated product, styrene-ethylene copolymer, and the like. These other polymers are polystyrene resins. Preferably less than 50% by weight, preferably 30% by weight As the full, particularly preferably such that 0-10% by weight, can be mixed according to the purpose.

The polystyrene resin has a melt flow rate (hereinafter referred to as MFR) of 0.5 to 30 g / 10 minutes, and 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.

The flame retardant used in the present invention uses a flame retardant composed of a brominated bisphenol ether derivative and a phosphate ester represented by the structural formula (1) as described above. By using this flame retardant, a polystyrene-based resin extruded foam plate having a sufficient effect in flame retardancy can be obtained.

The brominated bisphenol ether derivative used as a flame retardant in the present invention can efficiently generate bromine radicals exhibiting a flame retardant effect at the polystyrene resin decomposition temperature. The reason is that bromine is bonded to a tertiary carbon in which an alkyl group having 1 to 3 carbon atoms such as a methyl group represented by R in the following structural formula (1) is located. The commercially available similar structure flame retardant has a structure in which hydrogen is located at the site R in the following structural formula (1) and bromine is bonded to the secondary carbon. The carbon-bromine bond energy is greater in the structure in which bromine is bonded to secondary carbon than in the structure in which bromine is bonded to tertiary carbon. Therefore, it is presumed that bromine bonded to the tertiary carbon in the brominated bisphenol ether derivative used in the present invention decomposes at a lower temperature to generate a bromine radical and radicalize other bromine in a chain. The This is because a -5% heat loss temperature of a brominated bisphenol ether derivative having the same skeleton as in the present invention, for example, A in the following structural formula (1) is —C (CH ₃ ) ₂ — is R = H The hydrogenated brominated bisphenol ether derivative has a temperature of 300 ° C., while the R═CH ₃ brominated bisphenol ether derivative of the present invention has a temperature of 260 ° C., which confirms the action of the flame retardant. It is done.

As a flame-retardant mechanism of the brominated bisphenol ether derivative, bromine radicals generated by thermal decomposition from the flame retardant during combustion react with active radicals generated during polystyrene resin decomposition, thereby reducing the amount of generation, Decomposition of the resin that causes generation of decomposition products corresponding to fuel is suppressed. Moreover, the oxygen shielding effect by nonflammable gases, such as hydrogen bromide, also acts and can exhibit the outstanding flame retardance.

The brominated bisphenol ether derivative used in the present invention is a compound having the following structural formula.

（式中、Ｒは炭素数１〜３のアルキル基、Ａは−Ｃ（ＣＨ_３）_２−，−ＳＯ_２−，−Ｓ−，−Ｏ−，−ＣＯ−，または−ＣＨ_２−）

(Wherein R is an alkyl group having 1 to 3 carbon atoms, A is —C (CH ₃ ) ₂ —, —SO ₂ —, —S—, —O—, —CO—, or —CH ₂ —).

Specifically, brominated bisphenol ether derivatives represented by the structural formula (1) include 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane, bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] sulfone, bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] sulfide Bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] methane, etc., some of which are commercially available, otherwise the corresponding tetrabromo It can be synthesized by etherifying bisphenol with methallyl chloride or 2-alkylallyl chloride and then adding bromine to the double bond of the allyl group.

A preferred embodiment of the brominated bisphenol ether derivative used in the present invention is 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane. 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane has good compatibility with the polystyrene resin and has a decomposition initiation temperature of about 260 ° C. Since the melting point is about 115 ° C., it is preferable because it is easy to handle at the time of producing a foamed plate, has a low possibility of being decomposed at the time of kneading with a polystyrene resin, and exhibits an extremely high flame retardant effect. In addition, as a brominated bisphenol ether derivative in this invention, the 1 type (s) or 2 or more types of what is shown above can be added to a polystyrene-type resin.

In this invention, a brominated bisphenol ether derivative is added so that it may become a ratio of 0.5-5 weight part with respect to 100 weight part of polystyrene resins. Preferably, it is 0.5-4.5 weight part, More preferably, it is 0.7-4 weight part. When the addition amount is less than 0.5 parts by weight, it becomes difficult to obtain a sufficient flame retardant effect. Moreover, when the addition amount exceeds 5 parts by weight, physical properties such as mechanical strength of the foam may be deteriorated.

In the phosphoric acid ester used as a flame retardant in the present invention, the phosphoric acid group generates an acid by an oxidation reaction, and a stable adiabatic shutoff is caused by the progress of polymerization by heating and the production of polyphosphoric acid, and the dehydration carbonization of the phosphoric acid produced Since the layer is formed, excellent flame retardancy can be exhibited.

Specific examples of the phosphoric acid ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tris (2-ethylhexyl) phosphate, tris (butoxyethyl) phosphate, octyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, Aromatic condensed phosphates such as trixyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, cresyl di 2,6-xylyl phosphate, resorcinol bis (diphenyl phosphate), bisphenol A bis (diphenyl phosphate), etc. .

In addition, among the above phosphoric acid esters, triphenyl phosphate has good compatibility with polystyrene resins, is easy to handle at the time of foam plate production, and may be decomposed when kneaded with polystyrene resins. It is preferable because of its small size and high flame retardancy effect. In addition, as a phosphoric acid ester in this invention, the 1 type (s) or 2 or more types of what is shown above can be added to a polystyrene-type resin.

In this invention, phosphate ester is added so that it may become a ratio of 0.1-6 weight part with respect to 100 weight part of polystyrene resins, Preferably it is 0.5-4 weight part. When there is too much addition amount of phosphate ester, there exists a possibility that the mechanical strength of a foam may fall. In addition, if the amount of phosphate ester added is too large, phosphate ester has a high plasticity, so it has the effect of improving the fluidity of the resin, and the plasticity becomes too high, and the stability of extrusion foam molding during foam production May be reduced. On the other hand, if the addition amount of the phosphate ester is too small, sufficient expression of the flame retardant effect cannot be expected.

In the present invention, as described above, by using a specific brominated bisphenol ether derivative and a phosphate ester in combination, different flame retardant mechanisms act complementarily, and the flame retardant effect is expressed synergistically. . Specifically, the synergistic effect is recognized in the oxygen index that is an index of flame retardancy.

In the present invention, it is preferable that the weight ratio of the brominated bisphenol ether derivative to the phosphate ester (the blended weight of the brominated bisphenol ether derivative / the blended weight of the phosphate ester) is in the range of 0.3 to 30. The blending ratio is preferably 0.5 to 20, particularly 0.8 to 10. By blending both at the above blending ratio, the complementary flame retardant action of the phosphate ester with respect to the specific brominated bisphenol ether derivative is exhibited to the maximum extent.

As a method of blending the above flame retardant into the polystyrene resin, a predetermined proportion of the flame retardant is supplied together with the polystyrene resin to the raw material supply section provided in the upstream part of the extruder, and together with the polystyrene resin in the extruder A kneading method can be employed. 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. A method of supplying a liquid flame retardant previously heated and melted into the extruder, and a method of preparing a flame retardant master batch and supplying it to the extruder, especially from the viewpoint of dispersibility. It is preferable to employ a method of producing a fuel master batch and supplying it to an extruder.

The flame retardant masterbatch was prepared by using a polystyrene resin with an MFR of 0.5 to 30 g / 10 min for the base resin, 5 to 95% by weight of the flame retardant, and 40 to 95% by weight (difficult to be compared with the base resin). It is preferable to adjust it so that it is contained (when the total amount with the fuel is 100% by weight). Moreover, the brominated bisphenol ether derivative and the phosphate ester may be supplied simultaneously or separately. For example, a master batch made of a brominated bisphenol ether derivative, a phosphate ester, and a polystyrene resin may be prepared and supplied, or separately prepared master batches may be supplied.

In addition to the flame retardant composed of brominated bisphenol ether derivative and phosphate ester, the foamable resin melt composition includes metal soap, organotin compound, lead compound, hydrotalcite, epoxy compound, polyhydric alcohol, β-ketone, It is desirable to add a stabilizer such as a phenol compound, a hindered amine compound, a phosphorus compound, or a sulfur compound. The addition of the stabilizer has an effect of suppressing the molecular weight reduction and coloring of the polymer by capturing halogen radicals and halogen ions generated by decomposition of the brominated flame retardant during processing. The amount of the stabilizer added is preferably about 0.2 to 20 parts by weight, more preferably 1 to 15 parts by weight, assuming that the total weight of all flame retardants is 100 parts by weight.

In this invention, in the range which does not impair the effect of this invention, it can further use together with another flame retardant as needed. Other flame retardants include diphenylalkanes such as 2,3-dimethyl-2,3-diphenylbutane, antimony trioxide, diantimony pentoxide, ammonium sulfate, zinc stannate, cyanuric acid, isocyanuric acid, triallyl isocyanurate, Nitrogen-containing cyclic compounds such as melamine cyanurate, melamine, melam, melem, silicone compounds, inorganic compounds such as boron oxide, zinc borate, zinc sulfide, red phosphorus compounds, phosphorus compounds such as ammonium polyphosphate, phosphazene, tetra Halogenated aliphatic compounds such as bromocyclooctane, hexabromobenzene, pentabromotoluene, ethylenebispentabromodiphenyl, decabromodiphenyl oxide, 2,3-dibromopropylpentabromophenyl oxide, polybromophenylindane, Halogenated aromatic compounds such as lipentabromobenzyl acrylate, brominated polyphenylene oxide, brominated polystyrene or derivatives thereof, tetrabromobisphenol A, tetrabromobisphenol A bis (2,3-dibromopropyl) ether, tetrabromobisphenol A bis Halogenated bisphenol A such as (2-bromoethyl) ether, tetrabromobisphenol A diallyl ether and derivatives thereof, tetrabromobisphenol S, tetrabromobisphenol S bis (2,3-dibromopropyl) ether, tetrabromobisphenol S (2 -Bromoethyl) halogenated bisphenols S and derivatives thereof, tetrabromobisphenol A polycarbonate oligomer, tetrabromo Halogenated bisphenol derivatives oligomers such as Sphenol epoxy oligomers, halogen and nitrogen atom-containing compounds such as ethylenebis (tetrabromophthal) imide, tris (tribromophenoxy) triazine, tris (2,3-dibromopropyl) isocyanurate, Other halogen-based flame retardants such as halogen-containing phosphorus compounds such as tris (tribromoneopentyl) phosphate and tris (bromophenyl) phosphate can be mentioned. These compounds can be used individually or in mixture of 2 or more types.

The polystyrene-based resin extruded foam plate obtained by the production method of the present invention is excellent in flame retardancy by containing the specific flame retardant, but the use of this specific flame retardant and bubbles of the foam plate described later. By combining the structure and the remaining foaming agent composition in the foamed plate, a synergistic effect is obtained, and a polystyrene-based resin extruded foamed plate that satisfies the “combustibility standard of extruded polystyrene foam heat insulating plate” described in JIS A 9511 (1995) is obtained. be able to.

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.

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, and the like. -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 ether such as methanol, ethanol, isopropanol, propanol and other lower alcohols, alkyl chloride having 1 or 2 carbon atoms such as methyl chloride and ethyl chloride, carbon dioxide, nitrogen and water.

In order to obtain an extruded foam plate having a low apparent density, among the above physical foaming agents, a saturated carbonization 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. Hydrogen 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 combustible gas and is not preferred in terms of flame retardancy of the foam plate. 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 foam or two or more foaming agents selected from the group consisting of alkyl chlorides having 1 or 2 carbon atoms, dimethyl ether, diethyl ether, methyl ethyl ether, methanol, ethanol, carbon dioxide, and water. 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, to improve flame retardancy . By this, the heat insulation performance and flame retardance performance of the obtained foam board can be stabilized at an early stage.

In the present invention, the blowing agent comprises (a) 10 to 80 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, 90 to 20 mol% of one or more blowing agents selected from ethanol, water and carbon dioxide (however, the total amount of the blowing agent (a) and the blowing agent (b) is 100 mol%) Or (a) 5 to 70 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, dioxide 10 or 90 mol% of one or more blowing agents selected from carbon, and (c) 0,1 to 70 mol% of 1,1,1,2-tetrafluoroethane [wherein the blowing agent (a) The combination of the foaming agent (b) and the foaming agent (c) is 100 mol%] is preferable from the viewpoint of high foaming ratio, high heat insulation, and early stabilization of flame retardancy. .

The amount of the foaming agent added is difficult to specify because it increases or decreases depending on the type of foaming agent, the apparent density of the target foamed plate, the type of polystyrene resin, etc. About 0.7 to 2.5 moles per kilogram of polystyrene resin (in addition, when 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 ( When a plurality of physical foaming agents are used in combination, the total number of moles of constituent foaming agents 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 is 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 because it is easy to adjust the bubble diameter of the foamed plate obtained and to easily reduce the bubble diameter. Talc having a 50% particle size (permeation centrifugal sedimentation method) of 0.5 to 10 μm is preferred.

Moreover, the addition amount of this bubble regulator is added in the ratio of 0.1-5 weight part with respect to 100 weight part of polystyrene resins.

In the production method of the present invention, in addition to the above-mentioned bubble regulator and flame retardant, a heat insulation improver such as graphite, hydrotalcite, carbon black and aluminum, and a colorant, as long as the object and effect of the present invention are not hindered. Various additives such as antioxidants, fillers and lubricants can be appropriately added. 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-type resin extrusion foam board obtained by this invention is demonstrated.

The polystyrene resin extruded foam plate obtained by the present invention contains the brominated bisphenol ether derivative and phosphate ester represented by the structural formula (1) in the foam plate as a flame retardant as described above. . As a result, the intended object of the present invention can be achieved. Whether or not the brominated bisphenol ether derivative is contained in the foam can be confirmed by a known qualitative analysis method such as a method by infrared absorption spectrum analysis. Whether or not the phosphate ester is contained in the foam can be confirmed by a known qualitative analysis method such as a method by high performance liquid chromatography analysis.

Moreover, the apparent density of the said polystyrene-type resin extrusion foaming board is 20-60 kg / m < ³ >, Preferably it is a thing of 22-50 kg / m < ³ >. When the apparent density of the extruded foam plate is less than 20 kg / m ^3, it is very difficult to produce an extruded foam plate having such an apparent density, and the mechanical strength of the obtained extruded foam plate is also high. Since it becomes inadequate compared with the conventional foam heat insulation board, the use which can be used is 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.

The thickness of the polystyrene resin extruded foam plate obtained in the present invention is 10 to 150 mm, preferably 20 to 100 mm. If the thickness exceeds 150 mm, the bubble diameter in the thickness direction tends to be large, so there is a risk that sufficient heat insulation and dimensional stability cannot be ensured. A machine is required. On the other hand, when the thickness is less than 10 mm, there are difficulties in manufacturing, and the absolute mechanical strength and heat insulation may be insufficient.

The foamed plate contains at least a saturated hydrocarbon having 3 to 5 carbon atoms in the foamed plate, and the content thereof is 0.10 to 0.90 mol per 1 kg of the foamed plate, preferably 0. .15 to 0.75 mol, more preferably 0.20 to 0.65 mol. When the content of the saturated hydrocarbon having 3 to 5 carbon atoms includes two or more types of saturated hydrocarbon having 3 to 5 carbon atoms, the total number of moles of the saturated hydrocarbon is within the above range. Means that it is within. When the content of the saturated hydrocarbon having 3 to 5 carbon atoms is within the above range, a highly heat insulating material is obtained. Specifically, according to JIS A9511 (1995), Section 4.7, plate heat flow meter method (two heat flow meters, hot plate temperature high temperature side 35 ° C., hot plate temperature low temperature side 5 ° C., average temperature 20 ° C.) An extruded foam plate having a thermal conductivity of 0.040 W / m · K or less can be obtained. The lower limit of the thermal conductivity is not particularly limited, but is generally 0.02 W / m · K. If the saturated hydrocarbon content of 3 to 5 carbon atoms is less than 0.10 mol per 1 kg of foam plate, sufficiently high heat insulation can be maintained unless a foaming agent with low thermal conductivity such as HFC is included. When the content of saturated hydrocarbons having 3 to 5 carbon atoms exceeds 0.90 mol per 1 kg of the foam plate, there is a possibility that sufficient flame retardancy as a building material cannot be obtained. In the foamed plate, it is preferable from the viewpoint of environmental suitability that the foamed plate does not contain HFC or HCFC that may destroy the ozone layer.

In another foamed plate obtained by the present invention, the 1,1,1,2-tetrafluoroethane content in the foamed plate is 0 to 0.80 mol per 1 kg of the foamed plate, and the carbon number is 3 to 5. The content of the saturated hydrocarbon compound is 0.05 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, by combining the configuration of the average cell diameter in the thickness direction of the foam plate described later, the flat plate heat flow meter method (two heat flow meter method, hot plate) described in 4.7 of JIS A9511 (1995) The thermal conductivity at a high temperature of 35 ° C., a hot plate temperature of 5 ° C., and an average temperature of 20 ° C. It becomes possible to obtain an extrusion foamed board of K or less. The lower limit of the thermal conductivity is not particularly limited, but is generally 0.02 W / m · K. The content of 1,1,1,2-tetrafluoroethane in the foam plate is preferably 0.10 to 0.70 mol per kg of the foam plate, more preferably 0.15 to 0.60 mol per kg of the foam plate The content of the saturated hydrocarbon compound having 3 to 5 carbon atoms is preferably 0.10 to 0.70 mol per kg of the foam plate, more preferably 0.15 to 0.65 mol per kg of the foam plate . When the content of 1,1,1,2-tetrafluoroethane exceeds 0.80 mol per 1 kg of foamed plate, if the amount of foaming agent used is too large, internal foaming is likely to occur in the die during production. As a result, the surface state and mechanical strength of the molded article may be insufficient. Further, when the content of the saturated hydrocarbon compound having 3 to 5 carbon atoms is less than 0.05 mol per 1 kg of the foam plate, it is difficult to obtain a sufficiently high heat insulating property with the saturated hydrocarbon compound alone. In order to develop heat insulation, it is necessary to increase the content of a foaming agent having a low thermal conductivity such as HFC. When the content of the saturated hydrocarbon compound having 3 to 5 carbon atoms exceeds 0.80 mol per 1 kg of the foam plate, it leads to an increase in the use amount of the flame retardant for exhibiting excellent flame retardancy as a building material or the like. There is a fear.

1,1,1,2-Tetrafluoroethane has a low thermal conductivity of gas, remains in a polystyrene resin foam plate for a long period of time, and is nonflammable. High foam board is easy to obtain. Further, it is preferably used because the ozone depletion coefficient is zero. However, the global warming potential of 1,1,1,2-tetrafluoroethane is higher than that of saturated hydrocarbon compounds having 3 to 5 carbon atoms. Therefore, when 1,1,1,2-tetrafluoroethane is used, it is desirable to use it in combination with a saturated hydrocarbon compound having 3 to 5 carbon atoms. A foamed plate suitable for performance, heat insulation, environmental compatibility, etc. is obtained.

When 1,1,1,2-tetrafluoroethane is not used as a foaming agent or when the amount of 1,1,1,2-tetrafluoroethane used is reduced, a saturated hydrocarbon compound having 3 to 5 carbon atoms Among them, it is desirable to use one or more foaming agents selected from isobutane, isopentane, and cyclopentane, which are likely to remain in the foamed plate for a long period of time. A foam plate suitable for flammability, heat insulation, environmental compatibility, etc. is obtained.

The foaming agent content in the present specification is measured using a gas chromatograph. For example, a sample cut out from the center of the foam plate is placed in a sample bottle with a lid containing toluene, and after the lid is closed, the foaming agent in the extruded foam plate is dissolved in toluene by sufficiently stirring. It is possible to determine the content of isobutane, 1,1,1,2-tetrafluoroethane, etc. contained in the foam plate by performing gas chromatography analysis on the sample and quantifying it by an internal standard method. it can.

The above-mentioned foaming agent content in the foamed plate obtained in the present invention is adjusted when the physical foaming agent is supplied to the extruder in the production method of the present invention described above, the solubility of the foaming agent in polystyrene resin, gas This is done by determining the supply amount in consideration of the permeation speed. For example, a foaming agent composed of isobutane or 1,1,1,2-tetrafluoroethane has 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 whose content of a specific foaming agent is adjusted and whose apparent density is adjusted is obtained by 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. be able to.

The foamed plate obtained in the present invention has an average cell diameter in the thickness direction of 0.05 to 1.5 mm, preferably 0.06 to 1.0 mm, and more preferably 0.07 to 0.8 mm. Is preferred. When the average cell diameter is within the above range, the foamed plate has high heat insulating properties. The average cell diameter in the thickness direction is 0.05 to 0.3 mm, more preferably 0.06 to 0.25 mm, and particularly 0.07 to 0.20 mm in order to obtain a foam plate having higher heat insulation. Is preferred. When the bubble diameter is too small, it is difficult to obtain a foam plate having a large thickness and a small apparent density. On the other hand, if the bubble diameter is too large, there is a possibility that a foamed plate having the desired heat insulating property cannot be obtained. In addition, thermal conductivity according to the plate heat flow meter method described in 4.7 of JIS A9511 (1995) (two heat flow meters, hot plate temperature high temperature side 35 ° C., hot plate temperature low temperature side 5 ° C., average temperature 20 ° C.) In order to obtain a foam plate exhibiting a high degree of heat insulation such that 0.034 W / m · K or less, the above-mentioned condition of the average cell diameter is satisfied, and as described above, isobutane in the foam plate It is important that the content and the conditions of 1,1,1,2-tetrafluoroethane content are satisfied at the same time. This leads to a reduction in the usage amount of HFC and a reduction in the usage amount of combustible gas, and can bring about the effects of improving the suitability of 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 (DT: mm) in the thickness direction of the foam plate and the average cell diameter (DW: mm) in the width direction of the foam plate are obtained by foaming 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 plate extrusion direction (DL: mm) is the vertical cross section in the extrusion 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). , Enlarge the projected image on a screen or monitor, etc., draw a straight line in the direction to be measured on the projected image, count the number of bubbles intersecting the straight line, and the length of the straight line (however, this length is enlarged) It is not the length of the straight line on the projected image, but the length of the true straight line considering the magnification of the projected image.) Divided by the number of counted bubbles, and the average bubble diameter in each direction Ask for.

However, the measurement of the average bubble diameter (DT: mm) in the thickness direction is obtained by the following method. The average diameter of the bubbles present on each straight line is drawn from the length of each straight line and the number of bubbles intersecting the straight line in the thickness direction at a total of three locations in the center and both ends of the vertical cross section in the width direction. (The length of the straight line / the number of bubbles intersecting the straight line) is obtained, and the arithmetic average value of the obtained average diameters at the three locations is defined as the average bubble diameter (DT: mm) in the thickness direction.

The average bubble diameter (DW: mm) in the width direction is determined by the following method. At a position that bisects a total of three foam plates at the center and both ends of the cross section in the width direction, the straight line with a length of 30 mm is drawn in the width direction, and a straight line with a length of 30 mm (with the straight line) The average diameter [30 mm / (number of bubbles intersecting the straight line -1)] of the bubbles existing on each straight line is obtained from the number of intersecting bubbles-1), and the arithmetic average value of the average diameters of the three obtained positions is obtained. Is the average cell diameter in the width direction (DW: mm).

The average cell diameter (DL: mm) in the extrusion direction is determined by the following method. A straight line with a length of 30 mm is drawn in the extrusion direction at a position that bisects a total of three foam plates at the center and both ends of the vertical direction in the extrusion direction in the thickness direction. The average diameter [30 mm / (number of bubbles intersecting the straight line -1)] of the bubbles existing on each straight line is obtained from the number of intersecting bubbles-1), and the arithmetic average value of the average diameters of the three obtained positions Is the average cell diameter in the extrusion direction (DL: mm). Moreover, the average bubble diameter (DH: mm) of the horizontal direction of a foam board is an arithmetic mean value of DW and DL.

Furthermore, in the extruded foam plate obtained by the present invention, the bubble deformation rate is preferably 0.7 to 2.5. The bubble deformation rate is a value (DT / DH) calculated by dividing DT obtained by the above measurement method by DH. The smaller the bubble deformation rate is, the flatter the bubble is. The larger it is, the longer it is. If the bubble deformation rate 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 may also be reduced. There is. When the bubble deformation ratio exceeds 2.5, the number of bubbles in the thickness direction decreases, so that not only the desired high heat insulation property may not be obtained, but also the compressive strength from the side surface of the foam is reduced. There is a risk that stability will be reduced. From such a viewpoint, the bubble deformation rate is more preferably 0.8 to 2.0, and particularly preferably 0.8 to 1.5. When the bubble deformation rate is within the above range, a foamed plate having particularly high heat insulation can be obtained.

As a method for obtaining the above-mentioned foamed plate with the average bubble diameter adjusted to be small as mentioned above, there is a method of adding the above-mentioned bubble regulator, but simply increasing the amount of bubble regulator to increase the bubble Even if the diameter is adjusted to be small, the open cell ratio of the foamed plate increases, and as a result, the desired high heat insulating property cannot be easily obtained. Therefore, for example, considering the relationship between the MFR and the melt viscosity of polystyrene resin, the foam adjustment is performed by selecting a polystyrene resin that does not reduce the MFR even if the melt viscosity is high so that the above-mentioned open cell formation does not occur. 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 plate obtained by the present invention is mainly used as a heat insulating plate, it is particularly preferable to satisfy the flammability standard for an extruded polystyrene foam heat insulating plate 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 obtained in 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 high heat insulation performance can be maintained for a long period.

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 test piece without a molded skin cut to size is accommodated in a sample cup and measured, but when the thickness is thin and a test piece of 20 mm cannot be cut out in the thickness direction, for example, 25 mm × 25 mm × 10 mm The cut sample of the size of 2 is cut out, and the two cut samples may be stored in the sample cup as test pieces and measured.) Using the true volume Vx of the extruded foamed plate (test piece), The closed cell ratio S (%) is calculated by the following formula (1), and the average value of N = 3 is obtained.

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

Next, the present invention will be described in more detail with specific examples.
Examples 1-2 and Comparative Examples 1-2
[Raw materials and blending ratio]
The raw material is added to 100 parts by weight of polystyrene (PS Japan HH32) as a talc masterbatch (35% by weight of polystyrene and 60% by weight of talc (high filler # 12 made by Matsumura Sangyo Co., Ltd.)). Master batch consisting of 5% by weight of an agent], flame retardants are blended in the proportions shown in Table 1, and 10 parts by weight of stabilizers are blended with respect to 100 parts by weight of the total blend amount of all flame retardants, and foaming is performed. As an agent, a mixture obtained by mixing isobutane and methyl chloride at a ratio shown in Table 1 was used in an amount shown as Table 1 (expressed as a blowing agent injection amount per 1 kg of polystyrene (mol / kg)). As the flame retardant, 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane is used as a brominated bisphenol ether derivative, and triphenyl phosphate is used as a phosphate ester. It was. Flame retardants were appropriately mixed and used at the ratios shown in Table 1. Further, as the stabilizer, Irganox 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) / Adeka Stub PEP-36 (manufactured by Asahi Denka Kogyo Co., Ltd.) mixed at a 5/1 weight ratio is used. It was.

[Extruding 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. As the die lip, a die lip having a width of 115 mm and a gap of 1.0 mm (rectangular cross section) was used.

[Extrusion conditions]
Using the above extruder, 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 and melt. A foamable molten resin mixture having a resin temperature adjusted to 110 to 130 ° C. with a second extruder and a third extruder, which were made into a resin mixture, was extruded into the atmosphere from a die lip.
While foaming the foamable molten resin mixture extruded from the die lip, it is formed into a plate shape by passing between two guides made of polytetrafluoroethylene resin plates provided in parallel with a gap in the vertical direction, and extruded. A foam plate was produced.
Table 1 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent residual amount of the obtained extruded foamed plate.

Examples 3-4
Extruded foam plates were produced in the same manner as in Example 1 except that the talc masterbatch, flame retardant compounding ratio, and foaming agent compounding ratio were changed to the ratios shown in Table 1 and the die lip gap was changed to 1.5 mm. . Table 1 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent residual amount of the obtained extruded foamed plate.

Example 5
Extruded foam plates were produced in the same manner as in Example 3 except that the flame retardant compounding ratio was changed as shown in Table 1. Table 1 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent residual amount of the obtained extruded foamed plate.

Example 6
Extruded foam plates were produced in the same manner as in Example 1 except that the blending ratio of talc masterbatch and flame retardant was the ratio shown in Table 2, and the foaming agent composition was changed to a mixed system of isobutane, ethanol and carbon dioxide. . Table 2 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent residual amount of the obtained extruded foamed plate.

Example 7
Extruded foam plates were produced in the same manner as in Example 6 except that the foaming agent composition was changed to a mixed system of isobutane, dimethyl ether and carbon dioxide. Table 2 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent residual amount of the obtained extruded foamed plate.

Example 8
Example 1 except that the mixing ratio of the talc masterbatch and the flame retardant was changed to the ratio shown in Table 3 and the foaming agent composition was changed to a mixed system of 1,1,1,2-tetrafluoroethane, isobutane and methyl chloride. In the same manner, an extruded foam board was produced. Table 3 shows the apparent density, thickness, closed cell ratio, thickness direction average cell diameter, cell deformation rate, thermal conductivity, combustibility, moldability, and foaming agent residual amount of the obtained extruded foamed plate.

Example 9
Extruded foam plates were produced in the same manner as in Example 3 except that the flame retardant compounding ratio was changed to the ratio shown in Table 4. 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 residual amount of the obtained extruded foamed plate.

Example 10
Extruded foam plates were produced in the same manner as in Example 3 except that the flame retardant compounding ratio was changed to the ratio shown in Table 4. 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 residual amount of the obtained extruded foamed plate.

Comparative Example 3
Extruded foam plates were produced in the same manner as in Example 3 except that the flame retardant compounding ratio was changed to the ratio shown in Table 5. 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 residual amount of the obtained extruded foamed plate.

The measurement methods and evaluation methods for various physical properties of the extruded foam plates shown in Tables 1 to 5 are as follows.
[Apparent density]
It is a value measured based on JIS K7222 (1985).

[Thickness]
It is a value obtained by measuring at three locations where the width direction is equally divided into four and averaging them.

[Thickness direction average bubble diameter and bubble deformation rate]
It is a value measured by the method described above.

[Closed cell ratio]
It is a value measured by the above-described method using a cut sample without a molded skin cut to a size of 25 mm × 25 mm × 20 mm from the extruded foam plate.

[Thermal conductivity]
Immediately after production, the extruded foam plate was transferred to a room with an air temperature of 23 ° C. and a relative humidity of 50% and left in that room for 4 weeks. According to the description of JIS A 9511 (1995) 4.7, a plate heat flowmeter method described in JIS A 1412 (1994) using a thermal conductivity measuring device “Auto Λ HC-73 type” manufactured by Eihiro Seiki Co., Ltd. ( Measurement was performed based on a two-heat flow meter method, a hot plate temperature high temperature side of 35 ° C., a hot plate temperature low temperature side of 5 ° C., and an average temperature of 20 ° C.).

[Combustion quality]
The extruded foam board immediately after production was transferred to a room with an air temperature of 23 ° C. and a relative humidity of 50%, left in that room for 4 weeks, and then measured according to JIS A9511 (1995) 4.13.1 “Measurement Method A”. . In addition, the measurement cut out five test pieces from one foamed board (n = 5), and evaluated it with the following evaluation criteria.
A: All specimens disappeared within 3 seconds, and the average burning time of 5 specimens is within 2 seconds.
○: All specimens disappear within 3 seconds, and the average burning time of 5 specimens exceeds 2 seconds and is within 3 seconds.
X: The average burning time of 5 test pieces exceeds 3 seconds.

[Formability]
The extruded foam board was visually observed and evaluated according to the following evaluation criteria.
○: No cross-section voids, no wrinkles or protrusions on the surface, good appearance, and good stability during production.
X: Void and / or wrinkles and protrusions are prominently present on the cross section of the foamed plate, and the foamed plate has a poor appearance and lacks stability during production.

[Remaining foaming agent]
Measurement of residual amount of foaming agent (content of foaming agent per 1 kg of foamed board) of isobutane, methyl chloride, 1,1,1,2-tetrafluoroethane, and dimethyl ether is for foamed boards that have passed 4 weeks after extrusion foaming. As a result, Shimadzu Corporation, Shimadzu Gas Chromatograph GC-14B was used, and cyclopentane was used as an internal standard substance for measurement 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

Measurement of residual amount of foaming agent in ethanol (content of foaming agent per 1 kg of foamed plate) is based on an absolute calibration curve using GL Science Co., Ltd., Gas Chromatograph GC353B for a foamed plate that has passed 4 weeks after extrusion foaming. Measured based on the method.
The measurement conditions for gas chromatographic analysis are as follows.
Capillary column: made of fused silica, length 10 m × inner diameter 0.53 mm (CP-PoraPLOT Q Varian) stationary phase: 5% phenylmethylpolysiloxane 20 μm
Detector: FID
Detector (FID) temperature: 200 ° C
Sample vial heating temperature: 170 ° C
Sample vial heating time: 15 minutes Carrier gas: helium 5 ml / min
Column bath temperature: 50 ° C. × 5 min → 10 ° C./min (15 min) → 200 ° C. × 10 min

The reason for performing various tests on the foamed plates after 4 weeks is as follows. Most of the foaming agents that are easily permeable to polystyrene resins such as methyl chloride, dimethyl ether, carbon dioxide, and ethanol are those that come out of the polystyrene resin foam plate after production relatively early. In order to stabilize the performance and flame retardancy, it is cured and then these easily permeable foaming agents are diffused from the foam plate before shipment. The easy-permeability foaming agent is slightly different depending on the type, but when it is cured for about 4 weeks in a room with a normal temperature of 23 ° C and a relative humidity of 50%, most of the foam is dissipated from the foamed board, and heat insulation and flame retardancy In consideration of the stabilization, various tests were performed using the foamed plates after 4 weeks.

The results of the above examples and comparative examples show the following.
The results of Examples 1 to 10 show examples of producing low-density and thick polystyrene-based resin extruded foam plates using the flame retardant in the present invention within the scope of the present invention. It can be seen that the foamed plate obtained with excellent stability has good flame retardancy.

Examples 1 to 5 show examples in which the foaming agent composition is a mixed system of isobutane and methyl chloride. In Examples 1 and 2, it can be seen that high flame retardancy is obtained even when a relatively small amount of flame retardant is added. In Examples 3 to 5, it can be seen that the obtained foamed plate has a greatly improved heat insulating property because a specific amount of isobutane remains. It can also be seen that sufficient combustibility is ensured despite the large amount of remaining isobutane (combustible gas).

On the other hand, Comparative Example 1 is contrasted with Examples 1 and 2 and shows an example in which the amount of flame retardant used is below the lower limit of the present invention. The extruded foam plate thus obtained has no problems in molding stability, thermal conductivity, etc., but cannot have high flame retardancy.

Comparative Example 2 is contrasted with Examples 1 and 2 and shows an example in which the amount of flame retardant added exceeds the upper limit of the present invention. As a result, the stability of extrusion foaming was remarkably impaired due to the influence of large fluctuations in extrusion pressure, and a good extruded foam plate could not be obtained.

Example 6 shows an example in which the blowing agent composition is a mixed system of isobutane, ethanol and carbon dioxide. Example 7 shows an example in which the foaming agent composition is a mixed system of isobutane, dimethyl ether and carbon dioxide. Although the foam board obtained in Example 6 contains a small amount of ethanol, it turns out that sufficient flame retardance is ensured. It can be seen that the foamed plate obtained in Example 7 also has sufficient flame retardancy.

Example 8 shows an example in which the blowing agent composition was used in a 1,1,1,2-tetrafluoroethane, butane, methyl chloride mixed system. 1,1,1,2-Tetrafluoroethane is used to obtain high thermal insulation over a long period of time. For this reason, it turns out that high heat insulation is acquired. Moreover, it turns out that high flame retardance is ensured, although combustible gas exists.

Examples 9 and 10 show examples in which the foaming agent composition is a mixed system of isobutane and methyl chloride. It can be seen that the heat-insulating properties of the obtained foamed plate are greatly improved because a specific amount of isobutane remains. It can also be seen that sufficient combustibility is ensured despite the large amount of remaining isobutane.

On the other hand, Comparative Example 3 is contrasted with Example 3 and shows an example in which the brominated bisphenol ether derivative falls below the lower limit of the present invention. The extruded foam plate thus obtained has no problems in molding stability, thermal conductivity, etc., but cannot have high flame retardancy.

Claims (6)

A foamed plate having an apparent density of 20 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 at least a polystyrene-based resin, a bubble regulator, a flame retardant, and a foaming agent. In this method, the foam control agent includes an inorganic substance, and the inorganic substance is blended in an amount of 0.1 to 5 parts by weight with respect to 100 parts by weight of the polystyrene resin. The flame retardant includes the following structural formula (1 A brominated bisphenol ether derivative having a structure in which bromine is bonded to a tertiary carbon represented by formula (II) and a phosphate ester, and the brominated bisphenol ether derivative is 0.5 to 5 per 100 parts by weight of a polystyrene resin. The manufacturing method of the polystyrene-type resin extrusion foamed board characterized by mix | blending a weight part and this phosphate ester in the ratio of 0.1-6 weight part.

(Wherein R is an alkyl group having 1 to 3 carbon atoms, A is —C (CH ₃ ) ₂ —, —SO ₂ —, —S—, —O—, —CO—, or —CH ₂ —).   The said inorganic substance is a talc, Comprising: This talc is mix | blended with a polystyrene resin in the form of a talc masterbatch, The manufacturing method of the polystyrene resin extruded foam board of Claim 1 characterized by the above-mentioned.   The weight ratio of the brominated bisphenol ether derivative to the phosphate ester (the blended weight of the brominated bisphenol ether derivative / the blended weight of the phosphate ester) is 0.3 to 30. Manufacturing method of polystyrene resin extruded foam board.   The brominated bisphenol ether derivative having a structure in which bromine is bonded to the tertiary carbon is 2,2-bis [4- (2,3-dibromo-2-methylpropoxy) -3,5-dibromophenyl] propane. The manufacturing method of the polystyrene-type resin extrusion foam board of Claim 1, 2, or 3 characterized by the above-mentioned.   The blowing agent is (a) 10 to 80 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 20 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 foam board in any one of Claims 1-4.   The blowing agent is (a) 5 to 70 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, 10 or 90 mol% of one or more foaming agents selected from carbon dioxide; and (c) 0,1 to 70 mol% of 1,1,1,2-tetrafluoroethane [provided that the foaming agent (a ), The foaming agent (b), and the foaming agent (c) are 100 mol%]. The method for producing a polystyrene resin extruded foam plate according to any one of claims 1 to 4, wherein