JPH1149886A - Production of foamed synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the production of a foamed synthetic resin having homogeneous cells, and excellent in low thermal conductivity, surface appearance, size stability and environmental preservation without using a compound having a danger to break the ozone layer by using a specific foaming agent. SOLUTION: (A) An active hydrogen compound having two or more of active hydrogen-containing functional groups and reactive with an isocyanate group (e.g. a polyol having an OH-value of 200-1000 mg KOH/g) and (B) a polyisocyanate compound are made to react with each other in the presence of (C) a foaming agent composed of 1,1,1,3,3-pentafluoroethane (C1 ) and 1,1,1,2- tetrafluoroethane (C2 ), and optionally further a 3-6C hydrocarbon (C3 ) (e.g. a foaming agent containing C1 , C2 and C3 at ratios (C3 /C1 /C2 ) of (1-20)/(15-80)/(1-75) by weight. Thus, for example, a hard polyurethane foam can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foamed synthetic resin such as a polyurethane foam.
The present invention relates to a method for producing a foamed synthetic resin using a specific foaming agent.

[0002]

2. Description of the Related Art The production of a foamed synthetic resin by reacting an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a catalyst and a blowing agent is known. Widely used. Examples of the active hydrogen compound include a polyhydroxy compound and a polyamine compound. Examples of the foamed synthetic resin obtained include polyurethane foam, polyisocyanurate foam, and polyurea foam. In addition, examples of the relatively low foaming synthetic resin include synthetic wood.

Various compounds are known as a foaming agent for producing the above-mentioned foamed synthetic resin, and trichlorofluoromethane (hereinafter, CFC-11) has been mainly used. In addition, water is usually used together with CFC-11. Further, when foaming is performed by a floss method or the like, dichlorodifluoromethane (hereinafter, referred to as CFC-12) having a lower boiling point (gas at normal temperature and normal pressure) is used together with these.
Was used in combination.

[0004]

The chlorinated fluorinated carbon which is extremely stable in the air such as CFC-11 and CFC-12 which have been widely used in the past (hereinafter, "chlorinated fluorinated carbon" is referred to as "CFC") ) Reaches the ozone layer above the atmospheric layer without being decomposed, where it is decomposed by the action of ultraviolet rays and the like, and it has come to be considered that the decomposed product may destroy the ozone layer.

The above-mentioned CF used as a blowing agent
It is feared that the use of C may cause a part of ozone depletion because a part of it leaks into the atmosphere. Since it has a hydrogen atom in the molecule, it decomposes before reaching the ozone layer above the atmosphere, and is considered to be less dangerous. 2,2-Dichloro-1,1,1-trifluoroethane and 1,1-dichloro- Hydrochlorinated fluorinated carbon such as 1-fluoroethane and monochlorodifluoromethane (hereinafter, “hydrochlorinated fluorinated carbon” is referred to as “HCFC”) has been proposed as a foaming agent, and its use has been widespread.
These substances also have an ozone depletion potential and cannot be an essential solution. Therefore, such a CFC
In place of HCFC and HCFC, there is a demand for the development of a foaming agent having a lower risk of destruction of the ozone layer and a technique for producing a foamed synthetic resin.

It has been proposed to use hydrofluorinated carbon (hereinafter, "hydrofluorinated carbon" is referred to as "HFC") as an alternative foaming agent for CFC or HCFC.
JP-A-2-235982 describes that 1,1,1,3,3-pentafluoropropane can be used as a foaming agent for producing a polyurethane foam. Japanese Patent Application Laid-Open No. Hei 5-239251 discloses 1,1,1,
A method for producing a rigid polyurethane foam using 3,3-pentafluoropropane and water is described.

However, when only 1,1,1,3,3-pentafluoropropane is used as a blowing agent,
When only 1,3,3-pentafluoropropane and water were used as the foaming agent, there was a problem that it was difficult to obtain a foamed synthetic resin having a uniform cell size. Also, in the early stage of the foaming reaction in which the cells are formed, some of the cells may be destroyed by external factors before the cells are formed. If the cells are destroyed, the surface smoothness of the foamed synthetic resin becomes defective. And the surface appearance is impaired.

Japanese Patent Application Laid-Open No. Hei 3-7738 discloses 1,1,1
It is described that 1,2-tetrafluoroethane can be used as a blowing agent. However, when only 1,1,1,2-tetrafluoroethane is used as a blowing agent,
There has been a problem that floss voids are easily generated, which adversely affects the surface appearance and the like.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group, and a polyisocyanate compound. Is reacted in the presence of a blowing agent to produce a foamed synthetic resin, wherein 1,1,1,3,3-pentafluoropropane (hereinafter, referred to as HFC-245fa) and 1,1,1
1,2-tetrafluoroethane (hereinafter, HFC-134
a) is proposed, wherein at least two of the methods are used.

The present invention relates to HFC-245fa and HFC-1.
34a. By using these foaming agents in combination, in the present invention, a good foamed synthetic resin having uniform cells can be obtained.

When HFC-245fa is used alone, it is difficult to obtain a foamed synthetic resin having a uniform cell size. Also, in the early stage of the foaming reaction in which the cells are formed, some of the cells may be destroyed by external factors before the cells are formed. If the cells are destroyed, the surface smoothness of the foamed synthetic resin becomes defective. And the surface appearance is impaired. In addition, HFC-
When 134a is used alone, floss voids are likely to occur, which has a bad influence on the surface appearance and the like. In any case, when a large-sized molded product is molded, there is a problem that thermal conductivity, surface appearance, and dimensional stability are poor.

The weight ratio of HFC-245fa to HFC-134a is preferably from 20 to 99/1 to 80, particularly preferably from 40 to 99/1 to 60. Even when another compound is used as the third component as a foaming agent, the ratio of the two compounds is preferably within this range.

In the present invention, HFC-2 is used as a foaming agent.
Only 45fa and HFC-134a can be used, and other blowing agents can be used in combination. When other foaming agents are used in combination, water can be used in combination. It is particularly preferable to use water in combination. The amount of water used is as described below. When other foaming agents are used in addition to water, it is particularly preferable to use low boiling point hydrocarbons in combination.

The proportion of low-boiling hydrocarbons in all the blowing agents except water is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably 5% by weight or less. If the proportion of the low-boiling hydrocarbon exceeds 20% by weight, the flammability of the foaming agent component becomes remarkable, which is not preferable. By using a hydrocarbon in combination, the boiling point of the blowing agent is apparently increased, so that the workability is improved even in a system in which the proportion of the HFC-134a component is relatively large.

The hydrocarbon having a low boiling point is preferably a hydrocarbon having 3 to 6 carbon atoms. Examples of the hydrocarbon having 3 to 6 carbon atoms include n-butane, isobutane, n-pentane, isopentane, neopentane, cyclopentane, n-hexane,
Isohexane, cyclohexane, and the like. Cyclopentane is preferred.

At least one kind selected from hydrocarbons having 3 to 6 carbon atoms is selected from HFC-245fa and HFC-134a.
When used, at least one selected from hydrocarbons having 3 to 6 carbon atoms, 1,1,1,3,3-pentafluoropropane and 1,1,1,2-tetrafluoroethane, the usage ratio of this 1-20 / 15-80 /
It is preferably from 1 to 75. The usage ratio is 1 to 10
/ 15 to 80/19 to 75, preferably 1 to 5/40 to
80/19 to 50 are particularly preferred.

Compounds other than water and hydrocarbons,
Examples of the foaming agent that can be used in combination with HFC-245fa and HFC-134a include HFC-245fa and HFC-134a.
Other low boiling point HFCs, low boiling point fluorinated carbons, and inert gases. Examples of the inert gas include air and nitrogen. It should be noted that low-boiling HFC, low-boiling fluorinated carbon, and low-boiling hydrocarbon referred to in this specification have a boiling point of 100%.
It is preferable that the temperature is lower than 80 ° C, and it is more preferable that the boiling point is 80 ° C or lower.

HFC-24 in all blowing agents except water
The proportion of HFC other than 5fa and HFC-134a and fluorinated carbon is preferably 50% by weight or less, particularly preferably 20% by weight or less. The proportion of the inert gas in all the foaming agents except for water is preferably 10% by weight or less. Furthermore, HFC-245fa and HFC in all foaming agents except water
The ratio of the sum of -134a and hydrocarbons having 3 to 6 carbon atoms is preferably at least 50% by weight, particularly preferably at least 80% by weight. 100% by weight
Is most preferred.

The following compounds can be used as HFC and fluorinated carbon that can be used in combination. CH ₂ F ₂ , CF ₂ HCH
₃ , CF ₃ CF ₂ H, CF ₃ CH ₃ , CF ₃ CF ₂ CF ₂
H, CF ₃ CFHCF ₃ , CHF ₂ CF ₂ CHF ₂ ,
CF ₃ CF ₂ CFH ₂ , CF ₃ CHFCHF ₂ , CF ₃
CH ₂ CF ₃ , CF ₂ HCF ₂ CFH ₂ , CF ₃ CF ₂
CH ₃ , CF ₂ HCHFCF ₂ H, CF ₃ CHFCH
₂ , CFH ₂ CF ₂ CFH ₂ , CF ₂ HCF ₂ CH ₃ ,
CF ₂ HCHFCFH ₂ , CF ₃ CHFCH ₃ , CF ₂
HCH ₂ CF ₂ H, CF ₃ CH ₂ CFH ₂ , CFH ₂ C
F ₂ CH ₃ , CH ₂ FCHFCH ₂ F, CF ₂ HCHF
CH ₃ , CH ₂ FCH ₂ CF ₂ H, CF ₃ CH ₂ CH
₃ , CH ₃ CF ₂ CH ₃ , CH ₂ FCHFCH ₃ , CH
₂ FCH ₂ CH ₂ F, CHF ₂ CH ₂ CH ₃ , CH ₃ C
HFCH ₃ , CH ₂ FCH ₂ CH ₃ , CF ₃ CF ₂ CF
₂ CH ₃ , CF ₃ CH ₂ CH ₂ CF ₃ , CF ₃ CHFC
F ₂ CH ₃ , CF ₃ CHFCHFCF ₃ , CF ₃ CF ₂
CF ₂ CH ₂ F, CF ₃ CHFCH ₂ CF ₃ , CH ₃ C
F ₂ CF ₂ CHF ₂ , CF ₃ CF ₂ CHFCHF ₂ , C
F ₃ CF ₂ CH ₂ CHF ₂ , CF ₃ CH ₂ CF ₂ CH
₃ , CF ₃ CHFCHFCH ₃ , CF ₃ CH (CF ₃ )
CH ₃ , CH ₃ CF (CF ₃ ) CHF ₂ , CH ₃ CH
(CF ₃ ) CH ₂ F, CH ₃ CH (CF ₃ ) CHF ₂ ,
CH ₂ FCF (CF ₃ ) CH ₂ F, CH ₃ CF (CHF
₂ ) CHF ₂ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , C _{4
F 10, C 5 F 12,} C 6 F 14, C 7 F 16, C 5 F 10 ( perfluoro-cyclopentane), C ₆ F ₁₂ (perfluorocyclohexane), C ₆ F ₆ (perfluorobenzene).

The active hydrogen compound that can be used in the present invention is preferably a polyol widely used as a compound having two or more hydroxyl groups. A compound having two or more phenolic hydroxyl groups (eg, a phenol resin precondensate), an amine, and the like can also be used as the active hydrogen compound. In the present invention, as the active hydrogen compound, it is preferable to use only a polyol described below, or to use a polyol and a compound having a phenolic hydroxyl group or an amine in combination.

Examples of the polyol include a polyether polyol, a polyester polyol, a polymer having a main chain composed of a hydrocarbon polymer and having a hydroxyl group introduced into a terminal (hereinafter referred to as a hydrocarbon polymer having a hydroxyl group at a terminal), And polyhydric alcohols. The active hydrogen compound is preferably composed of only a polyol, and is composed of only a polyether-based polyol or a mixture of the polyether-based polyol with a small amount of a polyester-based polyol or a small amount of a hydrocarbon-based polymer having a hydroxyl group at a terminal as a main component. Is particularly preferred.

The polyether polyol is preferably obtained by reacting a cyclic ether with a compound containing an active hydrogen capable of reacting with the cyclic ether in the presence of a catalyst as an initiator.

Examples of the initiator include the following compounds or compounds obtained by adding a small amount of a cyclic ether to these compounds. A mixture of two or more of them may be used as the initiator. Ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, glycerin, trimethylolpropane, 1,2,6-hexane Polyhydric alcohols and sugars such as triol, pentaerythritol, diglycerin, tetramethylolcyclohexane, methyl glucoside, sorbitol, mannitol, dulcitol, and sucrose. Polyphenols such as bisphenol A and phenol-formaldehyde precondensate. Monoethanolamine, diethanolamine, triethanolamine, isopropanolamine,
Alkanolamines such as N- (2-aminoethyl) ethanolamine; Ethylenediamine, propylenediamine, hexamethylenediamine, piperazine, aniline,
Ammonia, N-aminomethylpiperazine, N- (2-
Aminoethyl) amines such as piperazine, 4-methyl-1,3-phenylenediamine, 2-methyl-1,3-phenylenediamine, 4,4′-diphenylmethanediamine, xylylenediamine, diethylenetriamine and triethylenetetramine.

The cyclic ether used in the present invention is a 3- to 6-membered cyclic ether compound having one oxygen atom in the ring, and specific examples thereof include the following compounds.
Ethylene oxide, propylene oxide, isobutylene oxide, 1-butylene oxide, 2-butylene oxide, trimethylethylene oxide, tetramethylethylene oxide, butadiene monoxide, styrene oxide, α-methylstyrene oxide, epichlorohydrin, epifluorohydrin, epibromo Hydrin, glycidol, butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, 2-chloroethyl glycidyl ether, o-chlorophenyl glycidyl ether, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, cyclohexene oxide, dihydronaphthalene oxide, 3 ,
Compounds having a 3-membered cyclic ether group such as 4-epoxy-1-vinylcyclohexane. Compounds having a 4- to 6-membered cyclic ether group such as oxetane, tetrahydrofuran, and tetrahydropyran.

Preferred are compounds having one 3-membered cyclic ether group (monoepoxides). Particularly preferred cyclic ethers are ethylene oxide, propylene oxide, isobutylene oxide and 1-butene which are alkylene oxides having 2 to 4 carbon atoms. Oxide, 2-butene oxide. The most preferred cyclic ether is propylene oxide or a combination of propylene oxide and ethylene oxide. Two or more cyclic ethers can be used in combination, and in that case, they can be mixed and reacted, or can be sequentially reacted.

Examples of the polyester polyol include a polyester polyol obtained by polycondensation of a polyhydric alcohol and a polycarboxylic acid. In addition, polycondensation of hydroxycarboxylic acid, cyclic ester (lactone)
, Polyaddition of cyclic ether to polycarboxylic anhydride, and polyester polyol obtained by transesterification of waste polyethylene terephthalate. Examples of the hydrocarbon-based polymer having a hydroxyl group at a terminal include hydrogenated polybutadiene polyol and polybutadiene polyol.

The polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol,
Dipropylene glycol, tripropylene glycol,
1,2-butanediol, 1,4-butanediol,
2,2-dimethyl-1,3-propanediol, 1,6
-Hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,
4-cyclohexanediol, 1,4-cyclohexanedimethanol, glycerin, trimethylolpropane,
1,2,6-hexanetriol, pentaerythritol, diglycerin, tetramethylolcyclohexane,
Examples include polyhydric alcohols such as methyl glucoside, sorbitol, mannitol, dulcitol, and sucrose, and saccharides.

As the polyol, a polyol composition in which fine particles of a vinyl polymer are dispersed in mainly a polyether-based polyol called a polymer polyol or a graft polyol can also be used.

When a rigid polyurethane foam is produced as a foamed synthetic resin, the hydroxyl value of the polyol is preferably from 200 mg to 1000 mg KOH / g.
350-600 mgKOH / g is particularly preferred. The polyol may be a mixture, in which case the average of their hydroxyl values is preferably from 200 mg to 1000 mgKOH / g, particularly preferably from 350 to 600 mgKOH / g.

When a flexible polyurethane foam or a semi-rigid polyurethane foam is produced as a synthetic foam resin, the polyol has a hydroxyl value of 20 to 200 mg KO.
H / g is preferred, and 20-100 mgKOH / g is particularly preferred. The polyols may be mixtures, in which case the average of their hydroxyl values is between 20 and 200 mg KOH
/ G, particularly preferably 20 to 100 mgKOH / g.

Compounds having two or more phenolic hydroxyl groups that can be used as an active hydrogen compound other than the above polyols include phenols such as bisphenol A, and phenols in the presence of an alkali catalyst in the presence of excess formaldehyde. The condensed resol type initial condensate, the benzylic type initial condensate reacted in a non-aqueous system when synthesizing this resol type initial condensate, and excess phenols were reacted with formaldehyde in the presence of an acid catalyst. Novolak type initial condensates and the like can be mentioned. The molecular weight of these initial condensates is preferably about 200 to 10,000.

In the above, the term "phenols" means those in which one or more carbon atoms of the skeleton forming a benzene ring are directly bonded to a hydroxyl group, including those having another substituent in the same structure. . Representative examples include phenol, cresol, bisphenol A, resorcinol, and the like. The formaldehyde is not particularly limited, but formalin, paraformaldehyde and the like are preferable.

The amines usable as the active hydrogen compound other than the above polyols include monoethanolamine and monoethanolamine.
Alkanolamines such as diethanolamine, triethanolamine, isopropanolamine, N- (2-aminoethyl) ethanolamine, ethylenediamine, propylenediamine, hexamethylenediamine, piperazine, N-aminomethylpiperazine, N- (2-aminoethyl) piperazine 4-methyl-1,3-phenylenediamine, 2-methyl-1,3-phenylenediamine,
Examples include polyvalent amines such as 4,4'-diphenylmethanediamine, xylylenediamine, diethylenetriamine, and triethylenetetramine.

Examples of the polyisocyanate compound include aromatic, alicyclic, and aliphatic polyisocyanates having an average of two or more isocyanate groups.
There are mixtures of more than one species, and modified polyisocyanates obtained by modifying them. Specifically, for example, 2, 4
Polyisocyanates such as tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (commonly called crude MDI), xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and polyisocyanates thereof; There are a polymer type modified product, a nurate modified product, a urea modified product, a carbodiimide modified product and the like.

When reacting an active hydrogen compound with a polyisocyanate compound, it is usually necessary to use a catalyst.
As the catalyst, a metal compound-based catalyst such as an organotin compound that promotes the reaction between an active hydrogen-containing group and an isocyanate group, and a tertiary amine catalyst such as triethylenediamine can be used. Further, a multimerization catalyst such as a metal carboxylate for reacting isocyanate groups may be used depending on the purpose.

In addition, foam stabilizers for forming good cells are often used. Examples of the foam stabilizer include a silicone-based foam stabilizer and a fluorine-containing compound-based foam stabilizer. Other optional additives include, for example, fillers, stabilizers, coloring agents, and flame retardants.

Using these raw materials, a foamed synthetic resin can be obtained. Examples of the foamed synthetic resin include polyurethane foam, urethane-modified polyisocyanurate foam, polyurea foam, microcellular polyurethane elastomer, microcellular polyurethaneurea elastomer, and microcellular polyurea elastomer. Polyurethane foams are roughly classified into rigid polyurethane foams, flexible polyurethane foams, and semi-rigid polyurethane foams. The foamed synthetic resin in the present invention can be produced by a one-shot method, a spray method, a prepolymer method, a quasi-prepolymer method, an RIM method, or the like.

As the foamed synthetic resin, rigid polyurethane foam, urethane-modified polyisocyanurate foam,
When producing other hard foam synthetic resins, HFC-245fa and HFC-134 which are the foaming agents in the present invention are used.
The amount of a used is HFC-245 based on the active hydrogen compound.
The total of fa and HFC-134a is preferably from 5 to 150% by weight, particularly preferably from 20 to 60% by weight.

When a hydrocarbon having 3 to 6 carbon atoms is used, the total amount of the hydrocarbon having 3 to 6 carbon atoms, HFC-245fa and HFC-134a is 5 to 180 with respect to the active hydrogen compound. Preferably 20 to 70% by weight
Is particularly preferred. In addition, water is preferably used in an amount of 0 to 10% by weight, particularly preferably 1 to 10% by weight, and more preferably 1 to 5% by weight based on the active hydrogen compound (water is not included as an active hydrogen compound). It is most preferred to use.

On the other hand, when producing a flexible foamed synthetic resin such as a flexible polyurethane foam, a semi-rigid polyurethane foam, or synthetic wood as the foamed synthetic resin, the amount of the specific foaming agent used in the present invention depends on the amount of the active hydrogen compound. On the other hand, the total of HFC-245fa and HFC-134a is 5 to 1
50% by weight is preferred, and 20 to 60% by weight is particularly preferred. When the hydrocarbon having 3 to 6 carbon atoms is used, the amount used is 3 to 6 carbon atoms, HFC-245fa and HFC.
-134a is preferably 5 to 180% by weight,
0-70% by weight is particularly preferred.

In the case of producing a flexible polyurethane foam or a semi-rigid polyurethane foam, water is contained in an amount of 0 to 10% by weight, particularly 1 to 10% by weight, based on the active hydrogen compound (water is not included as an active hydrogen compound). It is preferred to use. When producing synthetic wood, active hydrogen compounds (water is not included as active hydrogen compounds)
It is preferred to use 0 to 5% by weight, especially 1 to 5% by weight of water.

The present invention is particularly useful in the production of rigid foam synthetic resin, which is a field in which a large amount of halogenated hydrocarbon foaming agents are used, and is useful for producing rigid polyurethane foams, urethane-modified polyisocyanurate foams, and other rigid foam synthetic resins. Useful in the production of resins. Particularly suitable for the production of rigid polyurethane foams. It is particularly suitable as a method for producing a rigid polyurethane foam using a polyol having a hydroxyl value of 200 to 1000 mgKOH / g as an active hydrogen compound.

[0043]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Weight ratios (EG) of the following polyols a to d shown in Table 1
Used in. As foaming agents, HFC-245fa and H
A mixture of FC-134a and cyclopentane at the weight ratios (H to N) shown in Table 2 was used.

Polyol a: Polyether polyol having a hydroxyl value of 420 obtained by reacting propylene oxide with glycerin. Polyol b: sucrose is reacted with propylene oxide and then reacted with ethylene oxide to obtain a hydroxyl value of 45% with an oxyethylene group content of 10% by weight.
0 polyether polyol. Polyol c: a polyether polyol having a hydroxyl value of 440 obtained by reacting propylene oxide with ethylenediamine. Polyol d: 4-methyl-1,3-phenylenediamine reacted with propylene oxide and then reacted with ethylene oxide to obtain an oxyethylene group content of 1
5% by weight of a polyether polyol having a hydroxyl value of 450.

[0045]

[Table 1]

[0046]

[Table 2]

The evaluation of foaming was performed as follows. That is,
2 parts by weight of water and 2 parts by weight of a foaming agent of the type and amount (parts by weight) shown in Tables 3 and 4 with respect to 100 parts by weight of a polyol mixed in the above ratio E to G , And N, N-dimethylcyclohexylamine as a catalyst were mixed with a necessary amount for a gel time of 45 seconds to obtain a polyol mixture. The polyol mixture and polymethylene polyphenyl isocyanate were mixed at a liquid temperature of 20 ° C. so that the index would be 110, and 200 m
It was put into a wooden box of mx 200 mm x 200 mm and foamed to obtain a rigid polyurethane foam. The amount of the foaming agent used is such that the core density of the foamed synthetic resin body is 30 ± 2 k.
g / m ³ .

Next, the obtained rigid polyurethane foam was evaluated. The compatibility of the foaming agent with the polyol mixture and the evaluation of the appearance of the foam were evaluated according to the following criteria: 基準: good, Δ: good (somewhat good), ×: bad (poor). The dimensional stability was evaluated by measuring the rate of change in the thickness direction of the core of the foam before and after standing at −30 ° C. for 24 hours. ○ when the dimensional change rate is less than 3% (good and no problem in use), more than 3% to 5
Less than 5% △ (acceptable, little problem in use) More than 5% x
(Impossible, there is a problem in use). Evaluation of the thermal conductivity is such that the value of the thermal conductivity is 0.0150 kcal /
mhr ° C or less: ○ (good and no problem in use), 0.01
Over 50 kcal / mhr ° C and 0.0165 kcal / mh
A temperature of r ° C or less was rated as Δ (possible, with few problems in use). The results are shown in the table.

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

The present invention has the effect that a good synthetic foam resin can be produced without substantially using CFC or HCFC, which may cause ozone layer destruction.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hisashi Sato 3-474-2 Tsukakoshi, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Asahi Glass Co., Ltd.

Claims (6)

[Claims] A method for producing a foamed synthetic resin by reacting an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a foaming agent. As foaming agents,
1,1,3,3-pentafluoropropane and 1,
A method for producing a foamed synthetic resin, comprising using at least two kinds of 1,1,2-tetrafluoroethane. 2. The method according to claim 1, wherein 1,1,1,3,3-pentafluoropropane and 1,1,1,2-tetrafluoroethane are used in a weight ratio of 20 to 99/1 to 80. The manufacturing method as described. 3. A method for producing a foamed synthetic resin by reacting an active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a foaming agent. As the foaming agent, at least one selected from hydrocarbons having 3 to 6 carbon atoms,
1,1,3,3-pentafluoropropane and 1,
At least three kinds of 1,1,2-tetrafluoroethane are used, and the number of carbon atoms is 3 based on the total amount of the at least three kinds.
The method for producing a foamed synthetic resin according to claim 1, wherein the proportion of the hydrocarbons of Nos. To 6 is 20% by weight or less. 4. At least one kind selected from hydrocarbons having 3 to 6 carbon atoms, 1,1,1,3,3-pentafluoropropane and 1,1,1,2-tetrafluoroethane,
The method according to claim 3, wherein the composition is used in a weight ratio of 1 to 20/15 to 80/1 to 75. 5. The production method according to claim 1, wherein a rigid polyurethane foam is produced as the foamed synthetic resin. 6. The method according to claim 5, wherein a polyol having a hydroxyl value of 200 to 1000 mgKOH / g is used as the active hydrogen compound having two or more active hydrogen-containing functional groups capable of reacting with an isocyanate group.