WO2002077055A1

WO2002077055A1 - Crosslinked rigid vinyl chloride resin foam and process for producing the same

Info

Publication number: WO2002077055A1
Application number: PCT/JP2002/002885
Authority: WO
Inventors: Takeshi Sato; Youichi Oohara
Original assignee: Kaneka Corporation
Priority date: 2001-03-27
Filing date: 2002-03-26
Publication date: 2002-10-03
Also published as: JPWO2002077055A1

Abstract

A process for producing a crosslinked rigid vinyl chloride resin foam excellent in thermal stability, mechanical strength, solvent resistance, and heat insulation and having a finely cellular structure, using not a stabilizer such as a lead compound or cadmium compound but a safer stabilizer. It is characterized by incorporating a hydrotalcite compound into a foamable composition comprising a vinyl chloride resin, an acid anhydride, an isocyanate, a blowing agent, etc. and foaming the mixture.

Description

Akira Itoda Crosslinked rigid vinyl chloride resin foam and method for producing the same

The present invention relates to a crosslinked rigid vinyl chloride resin foam and a method for producing the same. More specifically, a crosslinked hard chloride having a fine cell structure that can be suitably used as a core material for ships and wind turbine blades, as well as a heat insulating material for liquefied natural gas storage tanks, tankers for transporting liquefied natural gas, and refrigeration vehicles. The present invention relates to a vinyl resin foam and a method for producing the same. Background art

Crosslinked rigid vinyl chloride resin foams are lightweight and have excellent mechanical strength such as compressive strength, tensile strength and bending strength, and are also excellent in solvent resistance, etc., and therefore contain a large amount of styrene monomer, for example. It is used as the core material of FRP laminates using unsaturated polyester resin and the core material of various laminated boards.

Also, because of its excellent thermal insulation, it is used as a storage tank for liquefied natural gas, a tanker for transporting liquefied natural gas, and a heat insulating material for refrigerated vehicles. As a method for producing the crosslinked rigid vinyl chloride resin foam, a vinyl chloride resin, an acid anhydride, an isocyanate, and a foaming agent are mixed to form a paste, and then heated and pressed to form a primary foam, and then hot water or There is a method of obtaining a foam by secondary foaming by contacting with steam.

There is a problem that the foam is discolored due to thermal degradation or excessive reaction during heating and pressurization. To cope with this, stabilizers such as lead compounds and cadmium compounds are usually added. However, in recent years, the use of lead compounds and power dome compounds has tended to be restricted from the viewpoints of human safety and industrial waste, and the use of safer heat stabilizers has been required.

To solve this problem, Japanese Patent Application Laid-Open No. H5-25256465 discloses that at least one isocyanate, at least one acid anhydride, at least one vinylidene compound, at least one vinylidene compound, A cellular foamed monopolymer product comprising a mixture of a foaming agent, a heat stabilizer, calcium stearate and zinc stearate has been proposed.

However, the technique disclosed in the above publication does not sufficiently improve the coloring, and has a problem in heat insulation due to the large average cell diameter of the foam.

In addition, the conventional crosslinked vinyl chloride resin foam generally has an average cell diameter of more than 1 mm and as large as about 2 mm. A large amount of unsaturated polyester resin is impregnated into the core material when the unsaturated polyester resin is cast on the material, and when an adhesive is applied on the core material during the production of laminated boards The core material is impregnated in a large amount with the agent, which not only increases the weight of the final product but also increases costs.

In order to solve such a problem, Japanese Patent Application Laid-Open No. Hei 5-194779 discloses that the foamable composition containing hydrazodicarbonamide as a nucleating agent is foamed to obtain an average cell of foam. A crosslinked vinyl chloride resin foam having a reduced diameter and a method for producing the same have been proposed.

However, in the technology disclosed in the above-mentioned publication, although the average cell diameter is slightly reduced, the effect is insufficient, and the closed cell ratio of the foam is low. In addition to the problem of impregnating the core material with a large amount of adhesive, there was a problem that the heat insulation was insufficient. The present invention has been made in view of the above prior art, and has a lead compound cadmium. Using a non-toxic heat stabilizer that has thermal stability in place of medium compounds and the like, it is excellent in thermal stability, mechanical strength, solvent resistance, and heat insulation, and is a crosslinked hard vinyl chloride resin foam and foam. It is intended to provide a method for producing a body. Disclosure of the invention

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and found that foaming a foamable composition containing a vinyl chloride resin, an acid anhydride, an isocyanate, a foaming agent, and a hydrated talcite compound. The use of highly safe stabilizers eliminates the use of stabilizers such as lead compounds and force-dominant compounds, resulting in excellent thermal stability, mechanical strength, and solvent resistance, as well as foam. It has been found that the average cell diameter becomes fine and a crosslinked rigid vinyl chloride resin foam having excellent heat insulation properties can be obtained.

In addition, it has been found that by adding a zinc compound to the foamable composition, a crosslinked hard vinyl chloride-based resin foam having further excellent thermal stability can be obtained. Further, by adding a / 3-diketone compound and / or a metal salt thereof to the foamable composition, a crosslinked rigid vinyl chloride-based resin foam having further improved thermal stability can be obtained. Was found.

Further, by foaming the foamable composition, the density is 20 to 20 Okg / m ³ , the closed cell ratio is 85% or more, and the average cell diameter is 0.1 to 1 mm. A crosslinked rigid vinyl chloride-based resin foam having a cell structure is obtained. This foam is made of an unsaturated polyester-based resin even when an unsaturated polyester-based resin is cast to produce an FRP laminate. The present inventors have found that the resin is not impregnated in a large amount, and even when an adhesive is applied to produce a laminate, the adhesive is not impregnated in a large amount and has excellent heat insulating properties. A hydrotalcite compound is used as a heat stabilizer for the vinyl chloride resin. The use of the same has been proposed in, for example, JP-A-55-80445 and JP-A-6-1174720, and Japanese Patent Publication No. 5-103772. Japanese Patent Laid-Open Publication No. 2002-210, proposes a method of adding a chemical foaming agent, talcite in the mouth, a specific zinc compound, and titanium dioxide to a halogen-containing resin, followed by heating and foaming.

However, the halogen-containing resin foam obtained in the above publication relates mainly to a method for producing a soft vinyl chloride-based resin foam represented by wall coverings, leather, and furniture products. Utilizing the characteristics of excellent mechanical strength, solvent resistance, and heat insulation, the core material of FRP laminates and various laminated boards, or storage materials for liquefied natural gas, tankers for liquefied natural gas transport, and insulation materials for refrigerated vehicles This is completely different from the above-mentioned crosslinked rigid vinyl chloride resin foam which is mainly used. Further, in these publications, there is no indication about miniaturization of the cell diameter of the foam.

That is, the present invention provides the following crosslinked rigid vinyl chloride resin foam and a method for producing the foam.

(1) A crosslinked rigid vinyl chloride resin foam obtained by foaming a foamable composition containing a vinyl chloride resin, an acid anhydride, an isocyanate, a foaming agent, and an hydrotalcite compound.

(2) The crosslinked rigid vinyl chloride resin foam according to (1), wherein the foamable composition further contains a zinc compound.

(3) The crosslinked rigid vinyl chloride-based resin foam according to (1) or (2), wherein the foamable composition further comprises a) 3-diketone compound and / or a metal salt thereof.

(4) The crosslinked rigid vinyl chloride resin foam according to any one of (1) to (3), wherein the density is 20 to 200 kg Zm ³ and the average cell diameter is 0.1 to 1 mm. . (5) The crosslinked rigid vinyl chloride resin foam according to any one of (1) to (3), wherein the foam has a density of 20 to 200 kgZm ³ and a closed cell ratio of 85% or more.

(6) The crosslinked rigid vinyl chloride resin foam according to any one of the above (1) to (5), which contains 0.01 to 20 parts by weight of a hydrotalcite compound based on 100 parts by weight of the vinyl chloride resin. body.

(7) The crosslinked rigid vinyl chloride resin foam according to any one of the above (2) to (6), wherein the zinc compound is contained in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the salt-based resin. body.

(8) The above-mentioned (3) to (10) containing 0.01 to 10 parts by weight of a) -diketone compound and / or Z or a metal salt thereof with respect to 100 parts by weight of the biel chloride resin.

(7) The crosslinked hard salt vinyl resin foam according to any one of the above (7).

(9) The crosslinked rigid vinyl chloride resin foam according to any one of the above (1) to (8), wherein the hydrotalcite compound is a hydrotalcite compound represented by the following general formula 1.

M _gl — _X A 1 _X (OH) ₂ (C0 ₃ ) _{x / 2} 'mH ₂ 0

· · · General formula 1

(Where X is 0 and a real number in the range of x≤0.5, and m indicates 0 or a real number.)

(10) The crosslinked rigid vinyl chloride resin foam according to any one of the above (1) to (8), wherein the hydrotalcite compound is a zinc-modified hide-mouth talcite compound represented by the following general formula 2.

Mg _yl Zn _y2 A l _x (OH) ₂ (C0 ₃ ) _{x / 2} -mH ₂ 0

· · · General formula 2

(Where x, _yi , and y ₂ represent real numbers that satisfy the condition represented by the following equation, and m represents 0 or a real number. 0 <χ≤0.5, y! + Y ₂ = 1 -x . y! ≥y ₂ )

(1 1) The method according to (2) to (10), wherein the zinc compound is a zinc carboxylate. A crosslinked rigid vinyl chloride resin foam as described in any of the above.

(12) The crosslinked rigid vinyl chloride resin foam according to any one of the above (2) to (10), wherein the zinc compound is at least one selected from zinc stearate and zinc hydroxystearate.

(13) The crosslinked rigid material according to any one of (3) to (12), wherein the 3-diketone compound is at least one member selected from the group consisting of dibenzoylmethane, stearoylbenzoylmethane, and acetic acid at the mouth. Foam of vinyl chloride resin.

(14) The crosslinked rigid vinyl chloride resin foam according to any one of the above (3) to (12), wherein the) -diketone compound is dibenzoylmethane.

(15) The foamable composition described in any one of the above (1) to (14) is heated and pressurized to cause primary foaming, and then is subjected to secondary foaming in the presence of hot water or steam. For producing a crosslinked rigid vinyl chloride resin foam. The foamable composition used to obtain the crosslinked rigid vinyl chloride resin foam of the present invention comprises a basic composition comprising a vinyl chloride resin, an acid anhydride, an isocyanate, and a foaming agent as components.

The vinyl chloride resin includes, for example, copolymers such as biel chloride homopolymer and vinyl chloride-vinyl acetate copolymer, and has compatibility with vinyl chloride in addition to these vinyl chloride homopolymers and copolymers. It is a concept that includes a mixture of the resins to be presented in an inferior amount.

Resins usually referred to as blend resins such as chlorinated vinyl chloride resins, chlorinated polyethylenes, and ethylene-vinyl acetate copolymers are preferable as resins that can be mixed with the vinyl chloride homopolymers and copolymers.

The average degree of polymerization of the vinyl chloride resin is preferably from 1,000 to 4,000, more preferably from 1,500 to 3,000. Among the above-mentioned vinyl chloride resins, those used for paste vinyl chloride resins can be so-called sol-like foamable compositions having fluidity, which may be industrially convenient to handle. Therefore, it can be suitably used. Here, the vinyl chloride resin for use in the paste vinyl chloride resin is an almost spherical fine powder having a particle size of several / m or less, and is produced by a so-called emulsion polymerization method and a micro-mouth suspension polymerization method. Wherein the fine powder is composed of many fine particles having a smaller diameter.

The content of the vinyl chloride resin is desirably 20 to 90% by weight, and preferably 30 to 70% by weight, based on the foamable composition.

If the content of the vinyl chloride resin is less than 20% by weight, the cell membrane of the foam tends to be broken at the time of foaming, and if it exceeds 90% by weight, the density of the foam becomes too large and the weight is reduced. It tends to lose its value as a structural material. Examples of the acid anhydride include monobasic carboxylic anhydrides such as propionic anhydride, isobutyric anhydride, and benzoic anhydride; phthalic anhydride; and dibasic carboxylic anhydrides such as maleic anhydride. These may be used alone or in combination of two or more.

The amount of the monobasic sulfonic acid anhydride and the amount of the dibasic sulfonic acid anhydride used is such that the basic carboxylic acid anhydride and the dibasic sulfonic acid anhydride are used alone. And whether they are used together, and cannot be decided unconditionally.

When the monobasic carboxylic acid anhydride is used alone without using the monobasic carboxylic acid anhydride and the dibasic carboxylic acid anhydride, the monobasic carboxylic acid anhydride is used. It is desired that the addition amount of the resin be 1 to 100 parts by weight, preferably 5 to 80 parts by weight, based on 100 parts by weight of the vinyl chloride resin. If the amount of the monobasic carboxylic acid anhydride is less than 1 part by weight, the crosslinking effect cannot be sufficiently exhibited, and if it exceeds 100 parts by weight, the foaming rate is high. There is a tendency that the cell film is broken due to too much cracking.

When the dibasic carboxylic acid anhydride is used alone without using the monobasic carboxylic acid anhydride and the dibasic carboxylic acid anhydride, the dibasic carboxylic acid anhydride is used. It is desired that the addition amount of the resin be 1 to 100 parts by weight, preferably 5 to 80 parts by weight, based on 100 parts by weight of the vinyl chloride resin. If the amount of the dibasic carboxylic acid anhydride is less than 1 part by weight, the crosslinking effect cannot be sufficiently exhibited, and if it exceeds 100 parts by weight, the foaming rate becomes too large and the cell membrane becomes too thick. It tends to break.

When the monobasic sulfonic acid anhydride and the dibasic sulfonic acid anhydride are used in combination, the addition amount of the monobasic sulfonic acid anhydride and the dibasic sulfonic acid anhydride may be reduced. The ratio (monobasic carboxylic anhydride, dibasic carboxylic anhydride) is desirably 25 Z75 to 595 by weight.

When the monobasic sulfonic acid anhydride and the dibasic carboxylic anhydride are used in combination, the total amount of the monobasic sulfonic acid anhydride and the dibasic carboxylic anhydride added is: The amount is preferably 1 to 100 parts by weight, more preferably 5 to 80 parts by weight, based on 100 parts by weight of the vinyl chloride resin. If the total added amount is less than 1 part by weight, the crosslinking effect cannot be sufficiently exhibited, and if it exceeds 100 parts by weight, the foaming rate becomes too high and the cell membrane tends to be broken. Examples of the isocyanate include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (monomeric MDI), polymethylenepolyphenylpolyisocyanate (polymeric MDI), and xylylene diisocyanate. And bifunctional or trifunctional or higher functional isocyanates such as hexamethylene diisocyanate. These isocyanates may be used alone or in combination of two or more.

When the foamable composition is heated in a molding die, the isocyanate dissolves the above-mentioned biel chloride resin and dissolves it in the order of molecular size. In this case, the isocyanate and the vinyl chloride resin are entangled.

As a result, when the isocyanate reacts with the acid anhydride and water during foaming, the vinyl chloride resin is physically incorporated into the crosslinked chains, and the obtained foam is The polymer chain of the vinyl resin and the crosslinked polymer chain formed by the reaction with the isocyanate, the acid anhydride, and water are entangled with each other, and a part of the crosslinked polymer chain has a high It is said to have a graft bond to the molecular chain, resulting in excellent properties such as solvent resistance, heat resistance, and mechanical strength. The crosslinked rigid vinyl chloride-based resin foam referred to in the present invention has such a structure.

The amount of the isocyanate to be added is preferably from 100 to 100 parts by weight, and more preferably from 20 to 80 parts by weight, based on 100 parts by weight of the vinyl chloride resin in order to sufficiently exhibit the crosslinking effect. Desirably, parts by weight are used.

If the amount of the isocyanate is less than 10 parts by weight, the crosslinking effect cannot be sufficiently exhibited, and if it exceeds 100 parts by weight, the crosslinking reaction tends to take a long time. The isocyanate generates carbon dioxide gas at the same time as the crosslinking reaction proceeds, and such carbon dioxide gas can be used as a foaming agent.

The foaming agent is broadly classified into a decomposable foaming agent and an evaporative foaming agent, and any of the foaming agents can be used in the present invention. Foaming agents are preferred.

Examples of the decomposable foaming agent include azobisisobutyronitrile, azodicarbonamide, diazoaminobenzene, N, Ν′-jetrosopene methylenetetramine, ρ-toluenesulfonylhydrazide, benzenesulfonylhydrazide, ρ-toluenesulfonyl semicarbazide, hydrazodicarbonamide and the like. These foaming agents may be used alone or in combination of two or more. Are used as a mixture.

Examples of the evaporative foaming agent include hydrocarbons such as propane and butane, and chlorofluorocarbon such as chlorofluorocarbon-123, and these foaming agents are used alone or in combination of two or more. Among these, it is preferable to use hydrocarbons such as propane and butane, which have a small effect on ozone layer depletion and global warming.

The amount of the blowing agent varies depending on the amounts of the isocyanate and the acid anhydride, the desired expansion ratio, the type of the blowing agent, and the like, and cannot be unconditionally determined.

When the foaming agent is the decomposable foaming agent, the amount of addition is 0.1 to 100 parts by weight of the vinyl chloride resin in order to impart a desired expansion ratio to the foam. It is desirable that the amount be 10 parts by weight, preferably 0.3 to 7 parts by weight, and more preferably 0.5 to 6 parts by weight. If the amount of the decomposable foaming agent is less than 0.1 part by weight, a desired expansion ratio cannot be imparted to the foam, and if it exceeds 10 parts by weight, the foamable composition is molded during multi-stage pressing. It tends to leak from the mold or break the cell membrane during foaming. Further, when the foaming agent is the evaporative foaming agent, the amount of the foaming agent to be added is preferably 0.1 to 100 parts by weight of the vinyl chloride resin in order to impart a desired expansion ratio to the foam. It is desirable that the amount be 1 to 10 parts by weight, preferably 0.3 to 7 parts by weight, and more preferably 0.5 to 6 parts by weight. If the amount of the evaporating foaming agent is less than 0.1 part by weight, a desired expansion ratio cannot be imparted to the foam, and if it exceeds 10 parts by weight, the foamable composition is molded during multi-stage pressing. It tends to leak from the mold or break the cell membrane during foaming. The foaming agent may be used in combination with a foaming aid such as urea if necessary.

The present invention relates to the foamable composition having the basic composition, further comprising: Site compound; 2) di-, hydrotalcite compound and zinc compound; 3) hydrated talcite compound;) 3-diketone compound and / or its metal salt; or 4) octidotalcite compound; / 3 —A diketone compound or Z or a metal salt thereof, and a zinc compound. The hydrated talcite compound is generally a metal double salt hydroxide represented by the following general formula 3.

(M ²⁺ ) (M ³⁺ ) _x (OH) ₂ (A ⁿ _) _{x / n} -mH ₂ O

• 1 x expression 3

(Wherein, ⁺ M ^{2 +} is ^{^{Mg 2, C a 2 +,}} N i 2+, Zn 2+, Fe 2+, n 2 +, of at least one divalent selected from the group consisting of Co ²⁺ . shows the metal M ^{3 +} is ^{^{a l 3+, F e 3+,}} C r 3+, represents at least one trivalent metal selected from the C o ^{3 +} the group consisting of a ⁿ -. the OH - _{^{, C0 3 2 -, S 0}} 4 2 -, N0 3 -., CI-, CH 3 COO-, represents at least one n-valent Anion selected from C 10 ₄ _ the group consisting of X is 0 rather x ≤0.5 is a real number in the range, and m is 0 or a real number.)

The hydrotalcite compound may be a natural product or a synthetic product.

Examples of the method for synthesizing the synthetic product include known methods described in JP-B-46-2280, JP-B-50-30039, JP-B-51-29129, and JP-A-61-174270. Can be

Further, the hydrated talcite compound can be used without being limited by its crystal structure, crystal particle diameter, presence or absence of crystallization water, and the amount thereof.

Further, the hydrated talcite compound has a surface of a higher fatty acid such as stearic acid, a higher fatty acid metal salt such as an alkali metal oleate, and Those coated with a metal salt of an organic sulfonic acid such as an alkali metal salt of silbenzene sulfonic acid, a higher fatty acid amide, a higher fatty acid ester or a wax can be used.

As the hydrotalcite compound, preferably, a magnesium-aluminum double metal hydroxide represented by the following general formula 1 or magnesium-zinc-aluminum obtained by partially modifying magnesium represented by the following general formula 2 with zinc Kyowa Chemical Industry Co., Ltd. under the trade name of Almizer 1, Almizer 2, Almizer 4, DHT-4A, etc. Commercially available products can be mentioned.

M _gl _ _x A 1 _x (OH) ₂ (C〇 ₃ ) _{x / 2} -mH ₂ 0

· · · General formula 1

(Where x is a real number in the range 0 <x≤0.5, and m indicates 0 or a real number)

_{_{_{Mg yl Zn y2 A 1 x (}}} OH) 2 (C0 3) x / 2 - mH 2 0

• · · ~ ^ x expression 2

(Where x, _yi , and y ₂ represent real numbers satisfying the condition represented by the following equation, and m represents 0 or a real number. 0 <x≤0.5, Υι + Υ ₂ = 1 -x Υ ! ≥Υ ₂ ) The addition amount of the hydrotalcite compound is 0.01 to 20 parts by weight, preferably 0.05 to 15 parts by weight, more preferably 0.1 to 20 parts by weight based on 100 parts by weight of the vinyl chloride resin. 1 to 10 parts by weight is desirable. If the amount of the talcite compound added is less than 0.01 part by weight, no effect can be obtained on heat stability and miniaturization of the average cell diameter. Not significantly improved.

Among the hydrotalcite compounds, a mug containing no zinc in the molecule As for the aluminum-aluminum-based hydrotalcite compound, it is preferable to separately add a zinc compound because the heat stability is excellent and the foaming speed is improved.

Examples of the zinc compound include zinc organic acids and inorganic zinc compounds.

Examples of the organic acid constituting the organic acid zinc include carboxylic acids, phenols, and organic phosphoric acids.

Examples of the carboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, force prillic acid, pelargonic acid, 2-ethylhexyl acid, force pric acid, neodecanoic acid, pendecanoic acid, and lauric acid , Myristic acid, palmitic acid, stearic acid, isostearic acid, 12-hydroxystearic acid, 12-ketostearic acid, phenylstearic acid, ricinoleic acid, linoleic acid, linoleic acid, oleic acid, araquinic acid, Aliphatic monobasic carboxylic acid or ketocarboxylic acid having 1 to 30 carbon atoms such as behenic acid, montanic acid, acrylic acid, and methacrylic acid (one kind of substituent such as hydroxyl group, aryl group, amino group, etc.) Or may have two or more kinds of benzoic acid, p-tert-butylbenzoic acid, toluic acid, Aromatic monobasic or dibasic carboxylic acids (lower alkyl groups, such as benzoic acid, ethyl benzoic acid, amino benzoic acid, salicylic acid, naphthenic acid, phthalic acid, isophthalic acid, terephthalic acid, hydroxyphthalic acid, aminophthalic acid, etc. (It may have one or more substituents such as a hydroxyl group or an amino group.), Adipic acid, oxalic acid, malonic acid, succinic acid, daltaric acid, maleic acid, fumaric acid, itacone Aliphatic dibasic carboxylic acids having 2 to 10 carbon atoms such as acids (which may have one or more substituents such as hydroxyl group, aryl group and amino group), trimellitic acid Aromatic tribasic or higher polybasic carboxylic acids such as pyromellitic acid (lower alkyl Or one or more of substituents such as a hydroxyl group, a hydroxyl group, and an amino group).

Examples of the phenols include phenol, cresol, xylenol, ethylphenol, isopropylphenol, n_butylphenol, tert-butylphenol, nonylphenol, dinonylphenol, octylphenol, isooctylphenol, and isohexylphenol. , 2-ethylhexylphenol, dodecylphenol, octadecylphenol, cyclohexylphenol, phenylphenol and the like.

Examples of the organic phosphoric acids include mono- or dioctyl phosphoric acid, mono- or di-dodecyl phosphoric acid, mono- or di-octyl decyl phosphoric acid, mono- or di- (nonylphenyl) phosphoric acid, nonylphenyl phosphonate, stearyl phosphonate, and the like. Is mentioned.

Examples of the inorganic zinc compound include zinc oxide, zinc hydroxide, zinc chloride, zinc carbonate, and zinc sulfate.

Among these, zinc carboxylate is preferred because of its excellent thermal stability when used in combination with the hydrated talcite compound, and more preferably an aliphatic monobasic zinc carboxylate having 10 to 20 carbon atoms. And particularly preferably zinc stearate and / or zinc hydroxystearate. The zinc compound is added in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the vinyl chloride resin. Parts by weight are desirable. If the amount of the zinc compound is less than 0.01 part by weight, the effect of improving the thermal stability cannot be obtained. If the amount exceeds 10 parts by weight, thermal decomposition due to zinc burning is apt to occur. However, problems such as coloring and deterioration of physical properties are likely to occur. Further, in the present invention, a metal other than zinc is used as the heat stabilizer of the foamable composition. An organic acid salt containing

Examples of the metal other than zinc include lithium, potassium, sodium, calcium, barium, magnesium, strontium, tin, cesium, and aluminum.

Examples of the organic acid constituting the organic acid salt include carboxylic acids, phenols, and organic phosphoric acids.

Examples of the carboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, cabronic acid, enanthic acid, force prillic acid, pelargonic acid, 2-ethylhexylic acid, force pric acid, neodecanoic acid, pendecanoic acid, and lauric acid , Myristic acid, palmitic acid, stearic acid, isostearic acid, 12-hydroxystearic acid, 12-ketostearic acid, phenylstearic acid, ricinoleic acid, linoleic acid, linoleic acid, oleic acid, araquinic acid, Aliphatic monobasic carboxylic acid or ketocarboxylic acid having 1 to 30 carbon atoms such as behenic acid, montanic acid, acrylic acid, and methacrylic acid (one kind of substituent such as hydroxyl group, aryl group, amino group, etc.) Or two or more types), benzoic acid, p-tert-butylbenzoic acid, toluic acid, dimethyl Aromatic monobasic or dibasic carboxylic acids (lower alkyl groups, such as tyl benzoic acid, ethyl benzoic acid, amino benzoic acid, salicylic acid, naphthenic acid, phthalic acid, isophthalic acid, terephthalic acid, hydroxyphthalic acid, aminophthalic acid, etc. (It may have one or more substituents such as a hydroxyl group or an amino group.), Adipic acid, oxalic acid, malonic acid, succinic acid, daltaric acid, maleic acid, fumaric acid, itacone Aliphatic dibasic carboxylic acids having 2 to 10 carbon atoms such as acids (which may have one or more substituents such as hydroxyl group, aryl group, amino group), trimellitic acid Aromatic tribasic or higher polybasic carboxylic acids such as pyromellitic acid (substitution of lower alkyl group, hydroxyl group, amino group, etc.) Have a one or two or more of May be used).

Examples of the organic phosphoric acids include mono- or dioctyl phosphoric acid, mono- or di-dodecyl phosphoric acid, mono- or di-octadecyl phosphoric acid, mono- or di- (nonylphenyl) phosphoric acid, nonylphenyl phosphonate, stearyl phosphonate Esters and the like.

The 3-diketone compound is an organic compound having two carbonyl groups bonded to the same carbon atom (in some cases, having three or more carbonyl groups). And a compound represented by the formula and dehydroacetic acid are preferred.

R ¹ — COCHR ² — C〇— R ³ · · · General formula 4

In the general formula 4, R ¹ and R ³ each independently represent an alkyl group, an aryl group, an alkylaryl group or an aralkyl group, and R ² represents a hydrogen atom, an alkyl group, an aryl group, an alkylaryl group or an aralkyl group. Is shown. These groups may be substituted with one or more of a halogen atom, a hydroxyl group, an alkoxy group and the like. Examples of the alkyl group represented by R ¹ and R ³ include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, pendecyl, dodecyl, tridecyl, tetradecyl, pendecyl, hexadecyl, heptyl Alkyl groups having 1 to 25 carbon atoms such as decyl decyl and octadecyl; The aryl group includes an aryl group having 6 to 20 carbon atoms such as phenyl and naphthyl; and the alkylaryl group includes an alkyl group having 7 to 20 carbon atoms such as tolyl, xylyl, cumenyl, and mesityl. An aralkyl group includes an aralkyl group having 7 to 20 carbon atoms such as benzyl, phenethyl, styryl, and triphenylmethyl. Examples of the alkyl group represented by R ² include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, pendecyl, dodecyl, tridecyl, tetradecyl, pendecyl, hexadecyl, Alkyl groups having 1 to 25 carbon atoms, such as heptane decyl and octadecyl, and aryl groups include 6 to 20 carbon atoms, such as phenyl and naphthyl. Examples include alkylaryl groups having 7 to 20 carbon atoms such as tolyl, xylyl, cumenyl, and mesityl, and aralkyl groups having 7 to 2 carbon atoms such as benzyl, phenethyl, styryl, and triphenylmethyl. And an aralkyl group of 0. Examples of the) 3-diketone compound include dibenzoylmethane and steabe.

Tan, palmitoyl benzoyl methane, lauroyl benzoyl methane, distearoyl methane, dehydroacetic acid and the like.

The metal salt of the 3-diketone compound is also useful. Examples of the metal constituting the metal salt include lithium, sodium, potassium, magnesium, calcium, barium, strontium, zinc, aluminum, zirconium, and tin. No.

The 3-diketone compound is preferably dibenzoylmethane, stearoyl benzoylmethane, or dehydroacetic acid, because heat stability is excellent when used in combination with the hydrotalcite compound. It is zylmethane. The amount of the above-mentioned) 3-diketone compound and / or metal salt thereof is 0.01 to 10 parts by weight, preferably 0.05 to 8 parts by weight, based on 100 parts by weight of the vinyl chloride resin. And more preferably 0.1 to 5 parts by weight. If the amount of the 3-diketone compound and Z or its metal salt is less than 0.01 parts by weight, the effect of improving the thermal stability cannot be obtained, and if the amount exceeds 10 parts by weight, However, the effect is not significantly improved.

In the present invention, an antioxidant such as an epoxy compound, a polyhydric alcohol, a phosphorus-based, a phenol-based, or a sulfur-based compound can be added as a heat stabilizer for the foamable composition.

Examples of the epoxy compound include bisphenol-type or nopolak-type epoxy resins, epoxidized soybean oil, epoxidized linseed oil, epoxidized fish oil, epoxidized tallow oil, epoxidized castor oil, and bisphenol A diglycidyl ester. Tell and the like.

Examples of the polyhydric alcohol include pentaerythritol, diphenyl erythritol, sorbitol, mannitol, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentyl erythritol! ^ Stearic acid partial ester, bis (dipentyl erythritol) adipate, glycerin, diglycerin, tris (2-hydroxyethyl) isocyanurate and the like.

Examples of the phosphorus antioxidants include, for example, triphenyl phosphite, diphenyldecyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, tris (2-ethylhexyl) phosphite, tributyl phosphite, Dilauryl acid phosphite, dibutyl acid phosphite, tris (dinonylphenyl) phosphite, trilla peryltrithiophosphite, trilauryl phosphite, bis (neoventildarichol) — 1,4-cyclohexanedimethylphos Fight, J Stearyl pentaerythri! ^ Ildiphosphite, bis (2,4-di-tert-butylphenyl) ^ Ildiphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythri] rudiphosphite, diphenylacid phosphite, tetradecyl-1,1,3-tris (2'-methyl-5 '— Tertiary butyl-4'-hydroxyphenyl) butane diphosphite, tetra (C 12-15 mixed alkyl) _4,4'-Sopropylidene diphenyl diphosphite, tris (4-hydroxy-1,2,5- Di-tert-butylphenyl) phosphite, tris (mono- and di-mixed nonylphenyl) phosphite, hydrogenated—4,4'-isopropylidene diphenol polyphosphite, diphenyl'bis [4,4'_n-butylidene Bis (2-tert-butyl-5-methylphenol)] thiodiethanol diphosphite, bis (octylphenol) 'bis [4,4'_n- Butylidenebis (2-tert-butyl-5-methylphenol)] _ 1,6-Hexanedioldiphosphite, phenyl-1,4'-Isopropylidenediphenol, phenol erythritol diphosphite, phenyl Diisodecyl phosphite, tetratridecyl [4,4'-n-butylidenebis (2-tert-butyl-5-methylphenol)] diphosphite, hexatridecyl [1,1,3-tris (2-tert-butyl-5-methyl) _4-hydroxyphenyl) butane] triphosphite, tris (2,4-ditert-butylphenyl) phosphite, and the like.

Examples of the phenolic antioxidants include, for example, 2,6-ditert-butyl P-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-tert-butyl). 4-hydroxyphenyl) monopropionate, distearyl (3,5-di-tert-butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycol bis [(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], To 1, 6_ Xamethylenebis [(3,5-ditert-butyl-4-hydroxyphenyl) propionate], 1,6-hexamethylenebis [(3,5-ditertbutyl-4-hydroxyphenyl) propionic acid Amido, 4,4, -Chobis

(6-tert-butyl-m-cresol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), bis [3,3_bis (4-hydroxy-3-tert-butylphenyl) petit Ric acid] glycol ester, 4,4'-butylidenebis (6-tert-butyl-m-cresol), 2,2, -ethylidenebis (4,6-di-tert-butylphenol), 2,2'-ethylidenebis (4 —Sec-butyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5_tert-butylphenyl) butane, bis (2_tert-butyl-4-methyl_6_) (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3 , 5—Tris ( 3,5-ditert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3, 5-tris (3,5-di-tert-butyl_4-hydroxyphenyl) propionyloxhetyl] isocyanurate, tetrakis

[Methylene-3- (3,5-ditert-butyl-4-hydroxyphenyl) butyl pionate] Methane, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methyl Benzyl) phenol, 3,9-bis [1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] —2,4,8,10-tetra Oxaspiro [5.5] undecane, triethylene glycol bis [(3_tert-butyl-4-hydroxy-5-methylphenyl) propionate] and the like. Examples of the sulfur-based antioxidant include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl and distearyl and polyols such as pentaerythritol tetra () 3-dodecylmercaptopropionate). —Alkyl mercaptopropionate esters.

Further, in the present invention, a plasticizer, a filler, a pigment, and the like may be added to the foamable composition as needed.

The plasticizer is not particularly limited as long as it is a normal plasticizer used for a vinyl chloride resin. Examples thereof include di-n-butyl phthalate, di-n-octyl phthalate, and di-2-ethyl phthalate. Phthalic acid plasticizers such as xyl, diisooctyl phthalate, octyl decyl phthalate, diisodecyl phthalate, di (C 7-9 mixed alkyl) phthalate, butyl benzyl phthalate, di-2-ethylhexyl isophthalate, and adipine Fatty acid ester plasticizers such as di-2-ethylhexyl acid, disodecyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, triptyl phosphate, Triester phosphate 2-ethylhexyl, tricresyl phosphate, trixylyl phosphate, etc. Agents, chlorinated paraffin, chlorinated plasticizer such as chlorinated fatty acid esters, E epoxy-based plasticizers, include such polyester plasticizer, these plasticizers may be used alone or in combination.

Examples of the filler include talc and calcium carbonate. These fillers are used alone or in combination of two or more.

The pigment is for coloring the obtained foam into a desired color. In addition to a white pigment that can also serve as an inorganic filler such as calcium carbonate, for example, titanium white, benzidine orange , Benzidine Elo, and Watching Red. It is desirable that the foamable composition is sufficiently kneaded using a kneading machine such as a double-arm kneader before filling the molding composition into a molding die to form a sol having a uniform composition.

The temperature at the time of kneading is not particularly limited, and usually may be around room temperature. Next, the prepared foamable composition is filled in a molding die made of, for example, an aluminum alloy, and the molding die is set in, for example, a multi-stage hot press of a hydraulic drive type. Close, mold, and heat.

The heating temperature varies depending on the components of the foamable composition, but may be an appropriate temperature according to the type and the amount of the foaming agent in the foamable composition, for example, 100 to 200, preferably 140 to 190. More preferably, it is preferably from 150 to 180.

When heating the foamable composition to the heating temperature, foamable composition, typically, 50~350 kgZcm ² 'about G, preferably 100~ 300 kg Zc m ² · G or so, more preferably 150 to 250 It has a pressure of about kg / cm ² 'G.

When the heating temperature reaches the above-mentioned temperature range, it depends on the shape of the molding die and the like, but it is usually desirable to maintain the state for about 10 to 50 minutes. Next, the pressurized heating plate temperature of the press machine is cooled to room temperature or a temperature near room temperature using a cooling medium such as water while the pressurizing mold is kept pressed, and the pressurizing mold is opened. A primary foam is obtained.

The acid anhydride in the foamable composition does not directly react with the isocyanate, but becomes a carboxylic acid in the presence of water, and the resulting carboxylic acid reacts with the isocyanate.

Accordingly, the obtained primary foam is brought into contact with hot water or steam to advance the reaction, and at the same time, secondary foaming is performed by the generated carbon dioxide gas. In this case, the temperature of hot water or steam is sufficient to allow the above reaction and secondary foaming to proceed. Therefore, it is desirable that the ratio be about 80 to 13, preferably 85 to 110, and more preferably 90 to 100. If the temperature is lower than 80 ° C, the cell does not expand to the desired expansion ratio, or even if expanded, it takes a long time for secondary expansion, and if it exceeds 130, the cell membrane tends to break. There is.

Thus, preferably, the density is 20~200 k gZm ^3, closed cell ratio of 85% or more, an average cell size of 0. lmm~ lmm crosslinked rigid vinyl chloride resin foam is obtained. As a result, it is not only high in hardness and excellent in various mechanical strengths, but also high in closed cell ratio compared to conventional foams and has a fine cell structure, so it is necessary to reduce the weight of ships, etc. It can be suitably used as a core material, and further as a heat insulating material for a frozen vehicle or the like that requires heat insulating properties.

If the density of the foam is less than 20 kg / m ³ , the mechanical strength is reduced, and if it exceeds 200 kgZm ³ , the heat insulating property is reduced, the weight is not sufficiently reduced, and the cost is increased. From this point, the density of the foam of the present invention is preferably 20~200 k gZm ^3, more preferably 30: 18 a O kgZ m ^3.

If the closed cell ratio of the foam is less than 85%, when the unsaturated polyester resin is cast during the production of the FRP laminate, the core material is impregnated with the unsaturated polyester resin in a large amount, and When fabricating the adhesive, when the adhesive is applied, the adhesive is impregnated into the core in a large amount, which not only increases the weight of the final product, but also increases the cost, and furthermore, the heat insulation is insufficient. From this point, the closed cell rate of the foam of the present invention is preferably 85% or more, more preferably 90% or more.

Also, if the average cell diameter of the foam is less than 0.1 mm, the mechanical strength tends to decrease. A large amount of unsaturated polyester resin is impregnated into the core material when the Japanese polyester resin is cast, and a large amount of the adhesive is impregnated into the core material when the adhesive is applied during the production of the laminate. This not only increases the weight of the final product, but also increases the cost and the insulation performance is insufficient. From this point, the average cell diameter of the foam of the present invention is preferably from 0.1 to 1 mm, more preferably from 0.2 to 0.9 mm.

In general, the cell diameter of a foam tends to increase as the density of the foam decreases, and to decrease as the density of the foam increases. Lever to take this into account, for example, in the range density of 20~50 k gZm ³ of the foam of the present invention, average cell diameter of 0. 3mm~l. 0mm, especially 0. 4mm~0. 9m m is preferably at, the foam range density of 50 to 200 kg / m ³ of the present invention, Lmm～0 average cell diameter is 0.. 8 mm, and even especially 0. 2 mm to 0. 7 mm preferable.

The crosslinked rigid vinyl chloride-based resin foam of the present invention has high hardness and various mechanical strengths, and has a fine cell structure. It can be suitably used as a heat insulating material for a frozen vehicle or the like that requires heat insulating properties. BEST MODE FOR CARRYING OUT THE INVENTION Next, a method for producing a crosslinked rigid vinyl chloride-based resin foam having a fine cell structure of the present invention will be described in detail with reference to Examples. However, the present invention is not limited to this.

Unless otherwise specified, “parts” indicates parts by weight.

Examples 1 to 29 and Comparative Examples 1 to 12

A raw material mixture was prepared to have the composition shown in Tables 1 to 3 (the amount of each component is shown in parts), and the mixture was weighed so that the total amount was 750 g. The mixture was kneaded with a 650 ml double-arm kneader at room temperature for 5 minutes to obtain a foamable composition. The obtained foamable composition was filled into a molding die made of an aluminum alloy having an inner dimension of 100 mm × 100 mm × 20 mm, set in a press machine, and the molding die was sealed and clamped.

Through steam to the press hot plate, a molding die temperature was raised to 175, then held by the pressure 170 kg / cm ² · G 25 minutes, then cooled to 30 or less throughout the industrial water to the press hot plate Then, the tightening pressure of the press was released, and the forming mold was opened to obtain a primary foam.

The dimensions of the obtained primary foam were 11 OmmX 11 OmmX 21 mm. Thereafter, the primary foam was secondarily foamed in hot water of 95%.

Next, the obtained secondary foam is put into about 30 industrial waters, left to cool for 30 minutes, taken out, and air-dried to remove the adhering moisture to obtain a crosslinked rigid vinyl chloride resin foam. Was.

Next, the crosslinked rigid vinyl chloride resin foam was finished to dimensions 10 OmmX 10 OmmX 25 mm using a slicer, and the density, closed cell rate, average cell diameter, thermal conductivity, coloring, discoloration, and safety were measured. Was determined according to the following method. The results are shown in Tables 1 and 2.

(A) Density

The weight (kg) and volume (m ³ ) of the crosslinked rigid vinyl chloride resin foam were measured and determined.

(B) Closed cell rate

Measured using a multipycnometer according to ASTM D-2856.

(C) Average cell diameter

The cross section of the crosslinked rigid vinyl chloride resin foam was photographed at a magnification of 20 times with a scanning electron microscope (manufactured by Hitachi, Ltd., model number: S-450), The photograph was copied with a dry copying machine.

On the copied screen, draw 10 straight lines containing 3 to 5 cells and divide the line length by the number of cells included in each line to obtain the average value of the cells included in each line Was calculated and averaged over 10 lines to obtain an average cell diameter.

(D) Thermal conductivity

A 100 mm × 100 mm × 25 mm sample was cut out from the crosslinked rigid vinyl chloride resin foam and measured at a temperature of 0 × according to JIS A 9511.

(E) Colorability

The degree of coloring of the surface of the crosslinked rigid vinyl chloride resin foam was visually determined according to the following criteria.

Re: white to yellow

△: yellow to light brown

X: Brown

(F) Discoloration degree

The degree of discoloration of the cross section of the crosslinked rigid vinyl chloride resin foam was visually determined according to the following criteria.

〇: Black discoloration is not seen

Δ: Black discoloration is partially observed

X: Black discoloration is mostly seen

(G) Safety

The judgment was made according to the following criteria.

〇: The foamable composition does not contain heavy metal compounds, which are regarded as problematic in terms of safety for human body and industrial waste.

X: The foamable composition contains heavy metal compounds that are considered to be problematic in terms of safety for human body and industrial waste table 1

Example

1 o T R u 7 a Q in 11 12 13 14

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90 pcs 8 Oft 2ft o 8 28 28 28 28 28 28 28 28

0 A

冊ノ--^ ^ ^ ^ ^-nn ^--^ ^-nn--nn nn nn 11 11 11 11 nn nn nn nn 11 nn 31 31 pcs * τΙ 1 Reno T / † |, II "7T-1 00 00 Click to click 99 22 22 22 22 22

No * i1so, a-age1, one k ^ -mu'koku,

, ノツノノ丁 W- Sonore Ono 1 1 7 1 7 1 7 1 7 1 7 1 7 1 ■ .7 / 1 7 17 1 7 1.7 1.7 1.7 1.7 azodicarponamide 7) 1 Q 1 Q 1 Q 1.9 1.9 Calcium carbonate 8) 70 70 7 /, 0 7 n 70 70 70 70 7.0 7.0 70 70 "7.0 7.0 7.0 Hide mouth talcite 9 ) 15 Q n ςη 15 15 3 n 3 n 30 50 30 30 3.0 50 Zinc modified hide mouth talcite 10) to Stearic acid IS 0 u.Run 10 0 R n Q 10 0 R

Cheap zinc hydroxystearate 0.6 0.6 constant dibenzoylmethane 0.5 0.5 0.3 0.5 0.5 0.3 0.5 0.3 agent stearoyl benzoylmethane 0.5

Epoxy compound 11)

Phenolic antioxidants 12)

Trif-enirile phosphite

Close (kg / m ³ ) 56 55 53 52 50 53 55 54 50 48 51 51 52 51 52 Closed cell rate (%) 91 93 95 94 95 94 93 94 95 92 93 94 93 93 94 Average cell diameter (mm) 0.49 0.46 0.45 0.47 0.40 0.48 0.50 0.47 0.48 0.49 0.48 0.48 0.46 0.48 0.49 Thermal conductivity (W mK) 0.026 0.026 0.026 0.026 0.025 0.026 0.026 0.026 0.026 0.026 0.026 0.026 0.026 0.026 0.026 Colorability △ OOOOOOOOOOOO 〇度 Discoloration degree Δ Δ Δ 厶 △ △ Δ OOOOO Δ 〇〇 Safety OOOOOOOOOOOO 〇〇〇

Table 2

Table 3

t O

(*): Foam with severe thermal decomposition cannot be obtained

note

1) PSH31 (average degree of polymerization 1700): manufactured by Kanegafuchi Chemical Industry Co., Ltd.

2) Phthalic anhydride: manufactured by Kawasaki Chemical Industry Co., Ltd.

3) Propionic anhydride: manufactured by Daicel Chemical Industries, Ltd.

4) Takenate 80: manufactured by Takeda Pharmaceutical Co., Ltd.

5) Lupranate M-20S: manufactured by Takeda Pharmaceutical Co., Ltd.

6) KBN10: Otsuka Chemical Co., Ltd.

7) Uniform AZ Ultra # 3245: Otsuka Chemical Co., Ltd.

8) Heavy calcium carbonate: Maruo Calcium Co., Ltd.

9) Almizer 1: Kyowa Chemical Industry Co., Ltd.

10) Almizer 4: Kyowa Chemical Industry Co., Ltd.

1 1) 0-130 P: manufactured by Asahi Denka Kogyo Co., Ltd.

12) AO-60: manufactured by Asahi Denka Kogyo Co., Ltd. From the results shown in Tables 1 to 3, the crosslinked rigid vinyl chloride resin foams of Examples 1 to 29 are compared with those of Comparative Examples 1 to 12. As a result, it can be seen that the foam has good thermal stability without using a stabilizer such as a lead compound or a cadmium compound and using a stabilizer having higher safety. In addition, the crosslinked rigid vinyl chloride resin foams of Examples 1 to 29 had higher closed cell ratios compared to the foams of Comparative Examples 1 to 12, despite the fact that the density of the foams hardly changed. Further, it can be seen that the average cell diameter has become finer, and the thermal conductivity value has accordingly decreased, and the heat insulation has been improved. Industrial applicability

According to the present invention, without using a stabilizer such as a lead compound or a force dome compound, a more stable stabilizer is used, and heat stability, mechanical strength, A crosslinked rigid vinyl chloride-based resin foam with a fine cell structure that is excellent in solvent resistance and heat insulation can be obtained, and can be used as a core material for ships and wind turbine blades, and as a storage tank for liquefied natural gas It can be suitably used as a heat insulating material for tankers for transporting liquefied natural gas, refrigerated vehicles, and the like.

Claims

Scope of word blue

1. A crosslinked rigid vinyl chloride resin foam obtained by foaming a foamable composition containing a pinyl chloride resin, an acid anhydride, an isocyanate, a foaming agent, and a hydrotalcite compound.

2. The crosslinked rigid vinyl chloride resin foam according to claim 1, wherein the foamable composition further contains a zinc compound.

3. The crosslinked rigid vinyl chloride resin foam according to claim 1 or 2, wherein the foamable composition further contains a / 3-diketone compound, and Z or a metal salt thereof.

4. The crosslinked rigid vinyl chloride resin foam according to any one of claims 1 to ³ , having a density of 20 to 200 kg Zm ³ and an average cell diameter of 0.1 to 1 mm. body.

5. The crosslinked rigid vinyl chloride resin foam according to any one of claims 1 to ³ , wherein the foam has a density of 20 to 200 kgZm ³ and a closed cell ratio of 85% or more.

6. The crosslinked hard chloride according to any one of claims 1 to 5, wherein the hydrotalcite compound is contained in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the vinyl chloride resin. Vinyl resin foam.

7. The crosslinked hard vinyl chloride resin according to any one of claims 2 to 6, wherein the zinc compound is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the vinyl chloride resin. Resin foam.

8. Claims 3 to 10 containing from 0.01 to 10 parts by weight of a / 3-diketone compound and / or a metal salt thereof per 100 parts by weight of the vinyl chloride resin. Item 8. The crosslinked rigid vinyl chloride resin foam according to any one of items 7.

9. The hydrotalcite compound represented by the following general formula 1 9. The crosslinked rigid vinyl chloride resin foam according to any one of claims 1 to 8, which is a graphite compound.

M _gl _ _x A 1 _x (OH) ₂ (C〇 ₃ ) _{x / 2} -mH ₂ 0

· · · General formula 1

(Where X is a real number in the range of 0 <x≤0.5, and m indicates 0 or a real number.)

10. The crosslinked rigid vinyl chloride resin foam according to any one of claims 1 to 8, wherein the hydrotalcite compound is a zinc-modified hydrotalcite compound represented by the following general formula 2.

_{_{_{Mg yl Zn y2 A 1 x (}}} OH) 2 (C0 3) x / 2 -mH 2 0

• · · Complete set ^

(Where x, y or y ₂ is a real number that satisfies the condition expressed by the following equation, and m is 0 or a real number. 0 <x≤0.5, y! + Y ₂ = 1 -x > y _χ ≥ y ₂ )

11. The crosslinked rigid vinyl chloride resin foam according to any one of claims 2 to 10, wherein the zinc compound is zinc carboxylate.

12. The crosslinked rigid vinyl chloride resin foam according to any one of claims 2 to 10, wherein the zinc compound is at least one selected from zinc stearate and zinc zinc stearate.

13. The crosslinking according to any one of claims 3 to 12, wherein the i3-diketone compound is at least one member selected from the group consisting of dibenzoylmethane, stearoyl benzoylmethane, and acetic acid at the mouth. Hard vinyl chloride resin foam.

14. The crosslinked rigid vinyl chloride resin foam according to any one of claims 3 to 12, wherein the / 3-diketone compound is dibenzoylmethane.

15. The foamable composition according to any one of claims 1 to 14 is heated and pressurized to cause primary foaming, and then is subjected to secondary foaming in the presence of hot water or steam. Method for producing crosslinked rigid vinyl chloride resin foam.