JPH0625457A - Stabilization of 1,1-dichloro-1-fluoroethane - Google Patents

Abstract

PURPOSE:To suppress the decomposition of 1,1-dichloro-1-fluoroethane without affecting the polymerization reaction for forming a urethane foam by adding specified compounds to a polyisocyanate. CONSTITUTION:A polyol and a polyisocyanate component containing a compound having at least one monohalomethyl group (the halogen being Cl, Br or I) and optionally a catechol and/or alpha,beta-diketone are foamed in the presence of a 1,1-dichloro-1-fluoroethane as the blowing agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to 1,1-dichloro-1
-Fluoroethane (hereinafter referred to as HCFC-141b)
The present invention relates to a method for suppressing the decomposition of HCFC-141b existing in the bubbles of a urethane foam produced by foaming by using as a foaming agent.

[0002]

2. Description of the Related Art Urethane foam is generally manufactured by adding polyisocyanate to a premix containing a polyol, a foaming agent, a catalyst, a foam stabilizer and the like.

Chlorofluorocarbon (hereinafter referred to as CFC) has been used as a foaming agent, but a reduction plan of its usage is being implemented as a causative substance of environmental problems such as ozone layer destruction and global warming.

Therefore, as a foaming method in the production method of urethane foam, a method of using carbon dioxide gas generated by the reaction of polyisocyanate and water as a part of the foaming agent without using CFC has been studied. It has been found that the urethane foam produced by the above-mentioned method is inferior to the product using CFC in heat insulating property and therefore its use is limited. On the other hand, a method of substituting with hydrochlorofluorocarbons such as HCFC-141b and 2,2-dichloro-1,1,1-trifluoroethane has also been studied. For example, toxicity of hydrochlorofluorocarbons themselves, storage stability, Detailed tests were conducted on storage stability in the premixed state, heat insulation of urethane foam, etc., and solutions have been proposed for all of them. In particular, a method using hydrochlorofluorocarbons has been desired in the production of rigid urethane foam, because it exhibits performance close to that of products using CFC-11 in terms of heat insulation.

Hydrochlorofluorocarbons are easily decomposed in the atmosphere and do not easily reach the ozone layer.
It is said that the effect on the ozone layer is only about 1/10 compared to FC-11, and its use is preferable from the viewpoint of environmental problems.

On the other hand, from the viewpoint of urethane foam products made of hydrochlorofluorocarbons, it is feared that the ease of decomposition of hydrochlorofluorocarbons may be a factor that impairs the long-term stability of urethane foam.

Up to now, mainly because CFC-11 was relatively stable, the reactivity or stability of the foaming agent in the closed cells of urethane foam has not been studied so much. However, since hydrochlorofluorocarbons have hydrogen atoms in the molecule, they are relatively highly reactive and are known to undergo dehydrohalogenation reaction and reduction reaction. Further, it is fully expected that the catalyst and active residues such as unreacted polyisocyanate remaining in the urethane foam after foaming will promote the same reaction and produce a decomposition product.

For example, HCFC-141b undergoes dehydrochlorination or dehydrofluorination reaction under special conditions of high temperature and basicity to decompose into 1-chloro-1-fluoroethylene or 1,1-dichloroethylene. To do. From such a phenomenon, the same reaction occurs in the air bubbles of the urethane foam product, which not only produces harmful substances but also deteriorates the basic physical properties such as shape and heat insulation property, and eventually the product. It is also worrisome that it will limit application areas.

Therefore, when using HCFC-141b as a foaming agent for urethane foam, it is essential to prevent HCFC-141b remaining in the urethane foam from undergoing a decomposition reaction.

Therefore, the present applicants have already used HCFC-1.
A method of adding various stabilizers to 41b has been proposed (Japanese Patent Application No. 3-324264). However, in the foam production of urethane foam, the foaming agent is usually prepared as a premix with a polyol, a catalyst, etc. and then mixed with polyisocyanate. May be stored over. In that case, there is a possibility that the stabilizer reacts with the base component in the amine or the polyol added as a catalyst in the premix to reduce the catalytic activity, thereby causing a decrease in the reactivity of polyurethane formation.

[0011]

In order to solve the above problems, the present inventors have examined the reactivity of HCFC-141b in the production of urethane foam whose main raw materials are polyols and polyisocyanates. As a result, the cause of this problem is that a catalyst or the like in the urethane foam formation reaction reacts with HCFC-141b to generate a decomposition product, and a compound containing a monohalogenated methyl group as a stabilizer in polyisocyanates. The present invention has been found to be able to suppress the reaction with HCFC-141b by deactivating the active site after foaming without causing deterioration of the catalyst in the premix, and has reached the present invention.

That is, in the present invention, at least the main raw materials are polyols and polyisocyanates, and when HCFC-141b is blended as a foaming agent to produce a urethane foam, a monohalogenated methyl group is added to the polyisocyanate component. A method for stabilizing HCFC-141b, which comprises adding a compound contained therein.

Further, HCFC-used in the present invention
141b includes β-diketones, keto acid esters, dicarboxylic acid esters, nitro compounds, phenols, amines, ethers, amylenes, and organic phosphine for the purpose of improving storage stability. It is also possible to add one or more compounds selected from fights, epoxides, furans, alcohols, ketones, catechols and triazoles.

In the method of the present invention, the stabilizer added does not inhibit the reaction for forming polyurethane, that is, the reaction between polyols and polyisocyanates, under the conditions that occur in the usual urethane foam manufacturing process. None, and the urethane foam itself after foaming or its decomposed product does not adversely affect the urethane foam over time.

Therefore, HCFC-containing a stabilizer is added.
Even when 141b is used as a foaming agent, an excellent foamed heat insulating material can be obtained without deteriorating the physical properties and chemical properties important for the urethane foam heat insulating material.

The compound having at least one monohalogenated methyl group (halogen is chlorine, bromine or iodine) as defined and used in the present invention is a monohalogenated methyl group (halogen is chlorine, bromine or iodine). iodine)
It suffices to have at least one structure of, and examples thereof include halides of saturated or unsaturated aliphatic compounds and aromatic compounds as described below.

Specifically, chloroethane, 1-chloropropane, 1-chlorobutane, 1-chloropentane and 1-chlorohexane, which are straight-chain aliphatic hydrocarbons whose terminals are chlorinated, brominated or iodinated. , 1-chloroheptane, 1-chlorooctane, 1-chlorononane, 1-chlorodecane, 1-chloroundecane, 1-chlorododecane, 1-chlorotridecane, 1-chlorotetradecane,
1-chloropentadecane, 1-chlorohexadecane, 1
-Chloroheptadecane, 1-chlorooctadecane, 1-
Chlorononadecane, 1-chloroeicosane, bromoethane, 1-bromopropane, 1-bromobutane, 1-bromopentane, 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromo Undecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane,
1-bromopentadecane, 1-bromohexadecane, 1
-Bromoheptadecane, 1-Bromooctadecane, 1-
Bromononadecane, 1-bromoeicosane, iodoethane, 1-iodopropane, 1-iodobutane, 1-iodopentane, 1-iodohexane, 1-iodoheptane, 1-iodooctane, 1-iodononane, 1-iododecane, 1-iodo Undecane, 1-iodododecane, 1-iodotridecane, 1-iodotetradecane,
1-iodopentadecane, 1-iodohexadecane, 1
-Iodoheptadecane, 1-iodooctadecane, 1-
Iodononadecane, 1-iodoeicosane, isobutyl chloride, isobutyl bromide, isobutyl iodide, isopentyl chloride, isopentyl bromide, isopentyl iodide, allyl chloride, allyl bromide, allyl iodide, propargyl chloride, propargyl bromide, iodide Propagyl, propylene chloride, propylene bromide, propylene iodide, 4-chloro-1,2-butadiene, 4-bromo-1,2-butadiene, 4-iodo-
1,2-butadiene, β-methallyl chloride, β-methallyl bromide, β-methallyl iodide and the like can be mentioned, and 1-bromopropane, 1-iodopropane, propargyl chloride and β-methallyl chloride are preferable.

Specific examples of the aromatic compound halide that can be used in the present invention include benzyl chloride and p.
-Chlorobenzyl chloride, xylylene chloride, 3,5-dimethylbenzyl chloride, trimethylene chloride, o chloride
-Methylbenzyl, benzyl bromide, α-chloro-o-xylene, α-chloro-p-xylene, cinnamyl chloride,
(2-chloroethyl) benzene, p-chlorobenzyl =
Bromide, xylylene bromide, 3,5-dimethylbenzyl bromide, trimethylene bromide, o-methylbenzyl bromide, benzyl iodide, α-bromo-o-xylene, α-bromo-
p-xylene, cinnamyl bromide, (2-bromoethyl)
Benzene, p-chlorobenzyl = iolide, xylylene iodide, 3,5-dimethylbenzyl iodide, trimethylene iodide, o-methylbenzyl iodide, α-iodo-o-xylene, α-iodo-p-xylene, iodine Thinamyl chloride, (2
-Iodoethyl) benzene etc. are mentioned, benzyl chloride, cinnamyl chloride, (2-bromoethyl) benzene etc. are preferable.

Further, in the present invention, alcohols, ethers, esters, ketones, carboxylic acids and the like have a monohalogenated methyl group (halogen is
Chlorine, bromine or iodine), and specifically, ethylene chlorohydrin, ethylene bromohydrin, ethylene iodohydrin, 1-chloro-
2-propanol, 1-bromo-2-propanol, 1
-Iodo-2-propanol, 3-chloro-1-propanol, 3-bromo-1-propanol, 3-iodo-
1-propanol, 3-chloro-1,2-propanediol, 3-bromo-1,2-propanediol, 3-iodo-1,2-propanediol, β-chloroisopropyl alcohol, β-bromoisopropyl alcohol,
β-iodoisopropyl alcohol, 3-chloropropylene glycol, 3-bromopropylene glycol, 3
-Iodopropylene glycol, chloroacetal, bromoacetal, iodoacetal, 2-chloroethyl = ethyl = ether, 2-bromoethyl = ethyl = ether, 2-iodoethyl = ethyl = ether, 2-chloroethyl = vinyl = ether, 2-bromoethyl = Vinyl = ether, 2-iodoethyl = vinyl = ether,
Chloromethyl = ethyl = ether, bromomethyl = ethyl = ether, iodomethyl = ethyl = ether, chloromethyl = methyl = ether, bromomethyl = methyl =
Ether, iodomethyl = methyl ether, ethyl chloroacetate, ethyl bromoacetate, ethyl iodoacetate, 3-
Ethyl chloride propionate, ethyl 3-bromopropionate, ethyl 3-iodopropionate, ethyl γ-chloroacetoacetate, ethyl γ-bromoacetoacetate, ethyl γ-iodoacetoacetate, methyl γ-chlorobutyrate, methyl γ-bromobutyrate. , Methyl γ-iodobutyrate, ethyl γ-chlorobutyrate, ethyl γ-bromobutyrate, ethyl γ-iodobutyrate, tris (2-chloroethyl) phosphate, tris (2-bromoethyl) phosphate, tris (2-iodoethyl) phosphate, chloro Acetone, bromoacetone, iodoacetone, phenacyl chloride, phenacyl bromide, phenacyl iodide, chloroacetic acid, bromoacetic acid, iodoacetic acid, 3-chloropropionic acid, 3-bromopropionic acid, 3-iodopropionic acid, γ-chlorobutyric acid , Γ-bromobutyric acid, γ-iodobutyric acid, epichlorohydrin, epibromo Dorin, is like epi iodo epichlorohydrin, 3-ethyl bromopropionate, ethylene epibromohydrin, epichlorohydrin and the like are preferable.

The stabilizers of the present invention can also be used in combination. As the substance to be combined, in addition to the compound having the above-mentioned monohalogenated methyl group, esters, diketones, catechols, quinones and the like are preferable, and acetylacetone, trifluoroacetone, benzoylacetone, benzoyltrifluoroacetone, dibenzoylmethane, Β-diketones such as furoylacetone, metapyrocatechol, pt-butylpyrocatechol, catechol diethyl ether, catechol dimethyl ether,
Catechols such as catechol di-n-propyl ether and catechol monoethyl ether are preferred.

The amount of the stabilizer added to the foaming agent in the present invention is 0.001 to 20% by weight, preferably 0.1 to 10% by weight, based on the foaming agent. If the addition amount is less than 0.001% by weight, the stabilizing effect is not recognized,
Further, when used in an amount of more than 20% by weight, the properties of the foaming agent and the physical properties of the molded foam may be deteriorated, which is not preferable.

The polyols used in the present invention include polyether polyols, polyester polyols and polymer polyols obtained by modifying these, PH
Also included are D (polyharnsstoff dispersion) polyether polyols, and polyether polyols modified with melamine, urethane, amine, silicone, ε-caprolactone, or the like.

The polyether polyol is obtained by adding an alkylene oxide having 2 to 6 carbon atoms (preferably ethylene oxide, propylene oxide, butylene oxide and tetrahydrofuran) to low molecular weight polyhydric alcohols, polyhydric phenols and amines. Or ring-opening polymerization. Those used for this purpose include ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol,
Divalent alcohols such as neopentyl glycol and cyclohexylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, hexanetriol, diglycerin and other polyhydric alcohols, hydroquinone, catechol, 1,
3,5-tris (4-hydroxyphenyl) benzene,
1,1,1-tris (4-hydroxyphenyl) ethane, 2,6-bis (2-hydroxy-5′-methylbenzyl) -4-methylphenol, bisphenol A (or tetramethylbisphenol, 1,1-bis -(4
-Hydroxyphenyl) -isobutane, 1,1-bis (4-hydroxyphenyl) -cyclohexane, 4,
4'-dihydroxydiphenyl sulfide, 4,4'-
Dihydroxydiphenyl, 4,4'-dihydroxydiphenylsulfone, etc.) phenols, triethanolamine, N-methyldiethanolamine, ethylenediamine, diethylenetriamine, tolylenediamine,
Amines such as diphenylmethanediamine can be used.

More specifically, the low molecular weight polyol-based polyether polyols include ethylene glycol, propylene glycol and glycerin, an ethylene oxide or propylene oxide addition polymer, or a random or block addition copolymer of ethylene oxide and propylene oxide. Examples of amine-based polyether polyols include N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N,
N, N'-tris (2-hydroxypropyl) -N'-
(2-hydroxyethyl) ethylenediamine, N, N,
Examples thereof include N ′, N ″, N ″ -pentakis (2-hydroxypropyl) diethylenetriamine, poly (oxypropylene) sucrose, poly (oxypropylene) sorbitol and the like.

The reaction of adipic acid, phthalic acid, etc. with ethylene glycol, propylene glycol, etc.
Mention may be made of polyester polyols obtained by ring-opening polymerization of caprolactam.

On the other hand, polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexane diisocyanate, 2,6. -Diisocyanate methyl caproate, bis (2-isocyanate ethyl) fumarate, bis (2-isocyanate ethyl) carbonate,
2-isocyanate ethyl-2,6-diisocyanate hexanoate, isophorone diisocyanate (IPD
I), 4,4′-diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate,
Methylcyclohexylene diisocyanate (hydrogenated TD
I), bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate, xylylene diisocyanate, diethylbenzene diisocyanate,
Examples thereof include toluene diisocyanate (TDI), a water-modified product of HDI, a trimer of IPDI, and the like, and a crude product or a mixture of two or more thereof. Further, in the present invention, the hydroxyl group-terminated urethane prepolymer and the isocyanate group-terminated urethane prepolymer made of the above compounds may be used instead of or together with the polyols and polyisocyanates.

As the catalyst, triethylamine, N, N
-Dimethylcyclohexylamine, N, N, N ', N'
-Tetramethylethylenediamine, N, N, N ', N'
-Tetramethylpropane-1,3-diamine, N, N,
N ', N'-tetramethylhexane-1,6-diamine, N, N, N', N ", N" -pentamethyldiethylenetriamine, N, N, N ', N ", N" -pentamethyldipropylene Aliphatic amines such as triamine and tetramethylguadinine, triethylenediamine, N, N'-
Dimethylpiperazine, N-methyl-N '-(dimethylamino) -methylpiperazine, N-methylmorpholine, N
-(N ', N'-dimethylaminoethyl) -morpholine, cyclic amines such as 1,2-dimethylimidazole, dimethylaminoethanol, dimethylaminoethoxyethanol, N, N, N'-trimethylaminoethyl-ethanolamine, Alcohol amines such as N-methyl-N ′-(2-hydroxyethyl) -piperazine and N- (2-hydroxyethyl) -morpholine, bis (2
-Amine catalysts consisting of ether amines such as dimethylaminoethyl) -ether, ethylene glycol (3-dimethyl) -aminopropyl ether, stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin Thiocarboxylate, dibutyltin dimaleate,
Organometallic catalysts such as dioctyltin mercaptide, dioctyltin thiocarboxylate, phenylmercuric propionate, lead octenoate, potassium octylate are used alone or as a mixture of two or more kinds.

In the present invention, other known chain extenders, crosslinking agents, surfactants, flame retardants, fillers, hydrolysis inhibitors, antioxidants, ultraviolet absorbers, antifungal agents, etc. in the production of urethane foam. Can be used.

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.

[0030]

【Example】

Example 1 Aromatic amine polyol (hydroxyl value 450 mg KOH
/ G) 100 parts by weight, 2 parts by weight of SH-193 manufactured by Toray Dow Corning Silicone Co., Ltd. as a foam stabilizer, 2 parts by weight of dimethylcyclohexylamine as a catalyst, 2 parts by weight of pure water and 40 parts by weight of HCFC-141b as a foaming agent. Parts were added to adjust the premix. 100 ml with stirrer
To a glass container, 20.0 g of premix and 20.0 parts by weight of benzyl chloride as a stabilizer were added, and 20.0 g of crude MDI consisting of diphenylmethane-diisocyanate and polyphenyl-polymethylene-polyisocyanate was left for 72 hours at 70 ° C. The mixture was mixed and stirred at a rotation speed of 3000 rpm for 8 seconds to obtain a urethane foam.

After mixing and stirring the premix with the crude MDI,
The time until the surface of the mixture began to turn white (cream time) was 11 seconds, and the time when the foaming volume became maximum (rise time) was 94 seconds, which was almost the same as when the stabilizer was not added.

After foaming, the mixture was left open for 24 hours, then sealed with a rubber stopper and kept at 60 ° C. for 5 days for HCFC-14.
An accelerated test of stability of 1b was performed. The composition of the gas released from the urethane foam was determined by sampling the gas phase of the glass container and analyzing it by gas chromatography. The results are shown in Table 1. In Table 1, 1-
Chloro-1-fluoroethylene (HCFC-1131
It is expressed as a ratio with HCFC-141b of a) set to 100.

Examples 2 to 4 The same experiment as in Example 1 was carried out except that the stabilizer shown in Table 1 was added instead of benzyl chloride. The results are shown in Table 1.

Example 5 The same experiment as in Example 1 was carried out by adding 1 part by weight of benzyl chloride and 0.1 part by weight of pt-butylpyrocatechol as stabilizers. The results are shown in Table 1.

Example 6 The same experiment as in Example 1 was conducted by adding 1 part by weight of benzyl chloride and 1 part by weight of acetylacetone as stabilizers. The results are shown in Table 1.

Comparative Example 1 At the same time, as a comparative example, the same experiment as in Example 1 was conducted without adding a stabilizer. The results are shown in Table 1.

Comparative Examples 2 to 5 A stabilizer was added to the premix, and the mixture was allowed to stand at 70 ° C. for 72 hours. Example 1 was added to the crude MDI without adding the stabilizer.
6 and Comparative Example 1 were conducted. The results are shown in Table 1.

[0038]

[Table 1]

[0039]

As is apparent from Table 1, when a urethane foam is produced using polyols, polyisocyanates, a catalyst and a blowing agent, a monohalogenated methyl group (halogen is By adding a compound having at least one of chlorine, bromine or iodine) to the isocyanate raw material, it was possible to suppress the decomposition of HCFC-141b as the foaming agent without affecting the polymerization reaction of the urethane foam.

Therefore, when produced by the method of the present invention, the urethane foam has a remarkable effect that it does not change its shape over a long period of time and can retain good initial properties in terms of heat insulating property.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location // C08G 18/08 NGP 8620-4J (C08G 18/00 101: 00) C08L 75:04

Claims (3)

[Claims] 1. At least main raw materials are polyols and polyisocyanates, and when 1,1-dichloro-1-fluoroethane is blended as a foaming agent to produce a urethane foam, a monohalogenated methyl group (halogen) is used. Is a method for stabilizing 1,1-dichloro-1-fluoroethane, which comprises adding a compound having at least one of chlorine, bromine or iodine) to the polyisocyanate component. 2. At least main raw materials are polyols and polyisocyanates, and when 1,1-dichloro-1-fluoroethane is blended as a foaming agent to produce a urethane foam, a monohalogenated methyl group (halogen) is used. Is a compound having at least one of chlorine, bromine or iodine), and one or more compounds selected from catechols or β-diketones are added to the polyisocyanate component. -A method for stabilizing fluoroethane. 3. A monohalogenated methyl group (halogen is
The method for stabilizing 1,1-dichloro-1-fluoroethane according to claim 1 or 2, wherein the compound having at least one (chlorine, bromine or iodine) is benzyl chloride, cinnamyl chloride and / or epichlorohydrin.