JPH08100044A - Production of rigid synthetic resin foam - Google Patents

Abstract

PURPOSE: To prevent the lateral expansion or normal-temp. shrinkage of a spray-foamed synthetic resin by mixing a specific active hydrogen compd. with a polyisocyanate together with a blowing agent, a catalyst, and a cell stabilizer and spraying the mixture to allow it to foam. CONSTITUTION: An active hydrogen compd. component which comprisies active hydrogen compds. each having at least two active hydrogen groups and contains 5-100 pts.wt. piperazine-base polyol formed by reacting a piperazine compd. with an alkylene oxide and having a hydroxyl value of 100-850, a polyisocyanate compd. in an amt. of 0.6-3.0 equivalents based on the total equivalents of the active hydrogen compd. component, water as the blowing agent in an amt. of 0.2-10wt.% based on the active hydrogen compd. component, a catalyst, and a cell stabilizer are mixed, sprayed, and foamed with a spray machine.

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 rigid foam synthetic resin such as rigid polyurethane foam by a spray machine.

[0002]

It has been widely practiced to produce a rigid foam synthetic resin by reacting an active hydrogen compound having an active hydrogen-containing functional group capable of reacting with an isocyanate group with a polyisocyanate compound in the presence of a foaming agent. There is. Examples of the active hydrogen compound include polyhydroxy compounds and polyamine compounds, and the resulting hard foam synthetic resin includes
Examples include rigid polyurethane foam and rigid polyisocyanurate foam.

As a foaming agent, R11 which is a specific CFC
(Trichloromonofluoromethane), and optionally R12 (dichlorodifluoromethane) are also commonly used with water. However, there is a concern that these specific CFCs may destroy the ozone layer in the stratosphere and affect biological systems,
Recently, its production and use are being restricted. Also in the field of polyurethane foaming, there is a demand for a drastic reduction in the amount of R11 and R12 used, or the total elimination thereof. At this time, by increasing the amount of water that generates carbon dioxide gas as a foaming agent component by the reaction with the polyisocyanate compound, R11, R1
The method of reducing 2 is taken.

[0004]

However, when the amount of water is increased, the foaming of carbon dioxide is slower at a lower temperature than the foaming of chlorofluorocarbon, so that the shrinkage of the foam becomes severe in the practical temperature range. Further, since the urea bond increases, the foam becomes brittle, and when it is adhered to a base material or a face material, the adhesiveness is remarkably reduced and the foam is liable to peel off / fall off. Further, when used as a spray foam, there arises a problem that the foam is lifted due to a phenomenon called so-called lateral expansion immediately after spraying. In particular, since spray foam is a construction method that is constructed on-site, it is difficult to manage, and it is easily affected by weather conditions such as temperature and humidity, and on-site conditions such as the type of sprayed surface. In particular, the above-mentioned problem is more serious in spraying in cold regions.

The present invention solves the above-mentioned problems when a large amount of water is increased by significantly reducing specific CFCs such as R11 used as a foaming agent in the production of rigid foam synthetic resin such as rigid polyurethane foam by a spray machine. With the goal.

[0006]

The present invention has been made to solve the above-mentioned problems. Ie at least 2
In a method for producing a hard foam synthetic resin by mixing, spraying and foaming an active hydrogen compound having an active hydrogenation-containing functional group and a polyisocyanate compound by a spray machine in the presence of a foaming agent, a catalyst and a foam stabilizer. The method for producing a rigid foamed synthetic resin, characterized in that, as at least a part of the active hydrogen compound, a piperazine-based polyether polyol obtained by reacting piperazine with an alkylene oxide is used, and water is used as a foaming agent. Is.

The piperazines in the present invention include piperazine, 2-methylpiperazine, 2-ethylpiperazine, 2-butylpiperazine, 2-hexylpiperazine,
C-grade alkyl such as 2,5-, 2,6-, 2,3- or 2,2-dimethylpiperazine, 2,3,5,6- or 2,2,5,5-tetramethylpiperazine Examples include substituted piperazine and aminoalkyl-substituted piperazine such as 1- (2-aminoethyl) piperazine. Particularly preferred in the present invention are piperazine and 1- (2-aminoethyl).
It is piperazine and has the structures shown in Chemical formulas 1 and 2, respectively.

[0008]

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[0009]

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In the present invention, the alkylene oxide added to the piperazines is preferably an alkylene oxide having 2 to 4 carbon atoms. Specifically, ethylene oxide,
At least one selected from propylene oxide, 1,2-butylene oxide and 2,3-butylene oxide is preferable. Particularly, propylene oxide alone or a combination of propylene oxide and ethylene oxide is preferable.

The hydroxyl value of the piperazine-based polyether polyol in the present invention is not particularly limited, but it is preferably 100 to 850 mgKOH / g, and particularly preferably 200 to 600 mgKOH / g.

In the present invention, the above-mentioned piperazine-based polyether polyol may be used alone as the polyol, or it may be used in combination with another active hydrogen compound. Other active hydrogen compounds include polyhydric alcohols, polyether polyols, polyester polyols,
There are compounds containing primary and secondary amino groups.

As the polyhydric alcohol, ethylene glycol, diethylene glycol, propylene glycol,
Glycerin, diglycerin, 1,4-butanediol,
1,6-hexanediol, trimethylolpropane,
There is pentaerythritol and the like.

Examples of polyether polyols include
The polyether polol obtained by adding the alkylene oxide or caprolactone to an initiator such as a polyhydric alcohol, a saccharide or an alkanolamine can be mentioned. A polyether polyol obtained by adding propylene oxide or ethylene oxide is particularly preferable. It is also possible to use a polyol composition in which fine particles of vinyl polymer are dispersed in a polyether-based polyol, which is called a polymer polyol or a graft polyol.

A compound having two or more phenolic hydroxyl groups (for example, a phenol resin initial condensate can also be used. As the compound having two or more phenolic hydroxyl groups, phenols can be used in excess in the presence of an alkali catalyst. Resol-type initial condensate that is condensation-bonded with formaldehyde, benzylic-type initial condensate reacted in a non-aqueous system when synthesizing this resol-type initial condensate, excess phenols with formaldehyde in the presence of an acid catalyst There is a reacted novolak type precondensate, etc. The molecular weight of these precondensates is preferably about 200 to 10,000.

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

Examples of polyester polyols include polyhydric alcohol-polyhydric carboxylic acid condensation type polyols and cyclic ester ring-opening polymer type polyols. As the primary or secondary amino group-containing compound, ethylenediamine,
Examples include propylenediamine, dioctylamine, the above-mentioned polyhydric alcohols, and compounds obtained by aminating the ends of polyether polyols.

The hydroxyl value of the polyol to be combined with these piperazine-based polyether polyols is not particularly limited, but usually the hydroxyl value is 100 to 850 mg.
KOH / g polyol is used.

The amount of piperazine-based polyether polyol used is preferably 5 to 100% by weight based on the total active hydrogen compounds. Particularly, 10 to 100% by weight is preferable.

The hard foam synthetic resin of the present invention is obtained by reacting the above active hydrogen compound and polyisocyanate compound as basic raw materials. Generally, it is necessary to use various additives other than this basic raw material. Usually essential additives are a foaming agent, a foam stabilizer, and a catalyst. Further optionally used additives include, for example, flame retardants, fillers,
There are stabilizers, viscosity reducers, colorants and the like. These additives are usually added to the polyol, but may be added to the polyisocyanate compound as needed.

In the present invention, water is used as a foaming agent. It is preferable to use 0.2 to 10% by weight, particularly 1 to 8% by weight, based on all active hydrogen compounds.

Further, in the technique of the present invention, it is preferable to use water as the sole foaming agent, but a low-boiling halogenated hydrocarbon can also be used in combination. As the low-boiling halogenated hydrocarbon, R11, R12, monochlorodifluoromethane (R22) 1,1,2-trichloro-1,2,
2-trifluoroethane (R113), 1,2-dichloro-1,1,2,2-tetrafluoroethane (R11
4), monochloropentafluoroethane (R115),
2,2-Dichloro-1,1,1-trifluoroethane (R123), 1,2-dichloro-1,1,2-trifluoroethane (R123a), 1,1-dichloro-1-
Fluoroethane (R141b), 1-chloro-1,1-
Difluoroethane (R142b), 3,3-dichloro-
1,1,1,2,2-pentafluoropropane (R22
5ca), 1,3-dichloro-1,1,2,2,3-pentafluoropropane (R225cb), 3-chloro-
1,1,2,2-Tetrafluoropropane (R244c
a), 1-chloro-1,2,2,3-tetrafluoropropane (R244cb), 3-chloro-1,1,2,
2,3-pentafluoropropane (R235ca),
1,1-dichloro-1,2,2-trifluoropropane (R243cc), 1,1,1,2-tetrafluoroethane (R134a), 1,1,1,2,3,3-hexafluoropropane ( There are fluorine-containing halogenated hydrocarbons such as R236ea), difluoromethane (R32), hexafluorobutane (R356) and dodecafluoropentane.

Other halogenated hydrocarbons containing no fluorine atom such as methylene chloride, fluorine-containing halogenated hydrocarbons other than the above, low boiling point hydrocarbons such as butane, hexane and isopentane, and inert gases such as air and nitrogen. There is.

Organopolysiloxane as a foam stabilizer
Nonionic surfactants such as polyoxyalkylene copolymers and silicone-glycol copolymers are exemplified. As the catalyst, a commonly used amine catalyst or metal catalyst can be used. Specifically, amino group-containing compounds such as triethanolamine, tetramethylhexamethylenediamine, triethylenediamine, bis- (2-dimethylaminoethyl) ether, dibutyltin dilaurate, lead octylate, lead naphthenate and other organic metals. The compounds are used alone or in combination.

The flame retardant is not particularly limited, but Tris (2
A halogen-containing phosphate compound such as -chloroethyl) phosphate, tris (2-chloropropyl) phosphate, and tris (dichloropropyl) phosphate is often used.

In polyurethane foaming, a method of mixing two components having an active hydrogen compound as one component and a polyisocyanate compound as another component is usually adopted. However, it is also possible to divide at least one component into two or more components and mix them into a total of three or more components. Further, the active hydrogen compound and the polyisocyanate compound can be reacted by a prepolymer method or a quasi-prepolymer method, but they are usually reacted by a one-shot method.

The polyisocyanate compound in the present invention can be appropriately used from those generally used conventionally. Typical examples are aromatic, alicyclic, or aliphatic polyisocyanates having two or more isocyanate groups, modified polyisocyanates obtained by modifying them, and mixtures of two or more thereof. .

Specifically, for example, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate (commonly known as MD MD).
I), polyisocyanates such as xylylene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate, and their prepolymer-type modified products, nurate modified products, and urea modified products. Crude MDI is particularly preferable. The amount used is 0.6 to 3.0 equivalents, particularly 0.8 to 2.0, based on the hydroxyl equivalents of all active hydrogen compounds.
Equivalent weights are preferred.

[0029]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Parts represent parts by weight. The polyols used are as follows.

Polyol A: 1- (2-aminoethyl)
Polyether polyol having a hydroxyl value of 450 mg KOH / g obtained by reacting piperazine with propylene oxide, and a hydroxyl value of 300 obtained in the same manner as polyol B: A.
mgKOH / g polyether polyol, polyol C: 1- (2-aminoethyl) piperazine, propylene oxide, obtained by reacting ethylene oxide with a hydroxyl value of 450 mgKOH / g polyether polyol, in the same manner as polyol D: C Obtained hydroxyl value 300
mg KOH / g polyether polyol.

Polyol E: hydroxyl value 450 obtained by reacting propylene oxide with triethanolamine
mgKOH / g polyether polyol, hydroxyl value 300 obtained in the same manner as polyol F: E
mgKOH / g polyether polyol, polyol G: hydroxyl value 450 obtained by reacting sucrose with propylene oxide mgKOH / g polyether polyol, polyol H: hydroxyl value 300 obtained in the same manner as G
mgKOH / g polyether polyol, polyol I: hydroxyl value 450 obtained by reacting ethylenediamine with propylene oxide, mgKOH / g polyether polyol, polyol J: hydroxyl value 300 obtained in the same manner as I
mg KOH / g polyether polyol.

The blowing agents used are as follows: blowing agent a: R141b, blowing agent b: R22, blowing agent c: R134a.

A total of 100 polyols of the types and proportions shown in the table
For each part, 1.5 parts of a silicone foam stabilizer (L-5421, manufactured by Nippon Unicar Co., Ltd.), as a catalyst, a triethylenediamine solution (DABCO33LV, manufactured by Air Products and Chemicals) and lead octylate (nickel octix lead 20%). , Manufactured by Nippon Kagaku Sangyo Co., Ltd.) and a necessary amount for the rise time during the foaming reaction at a liquid temperature of 10 ° C. to be about 10 to 25 seconds, and tris (2-chloropropyl) phosphate (TMCPP, large as a flame retardant. 10 to 20 parts of Hachi Chemical Co., Ltd. and the types and parts of the foaming agents shown in the table were added and mixed. This polyol mixture and crude diphenylmethane diisocyanate (Millionate MR-100, manufactured by Nippon Polyurethane Industry Co., Ltd., NCO content: 31.0% by weight) were mixed with a Gasmer foaming machine at a liquid temperature of 40 ° C. and an air temperature of 10 ° C. under concrete. Spray-foaming was performed on each of the base materials of the board, the gypsum board, and the plywood.

The evaluation of the core density (unit: kg / m ³ ) of the obtained polyurethane foam, the extent of lateral expansion, the dimensional stability at room temperature, and the adhesiveness of the foam to concrete pieces is shown in the table.

The evaluation of the degree of lateral expansion was as follows: ◯: no lateral expansion, good; x: lateral expansion, poor. The evaluation of the dimensional stability at room temperature was ◯: good, ×: poor. The evaluation of the adhesiveness of the foam to the concrete pieces was evaluated as follows: good: good adhesiveness, bad: poor adhesiveness.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

[0041]

[Table 6]

[0042]

INDUSTRIAL APPLICABILITY In a method for producing a rigid polyurethane foam by a spray method using water as a foaming agent,
There is an effect that a polyurethane foam having good adhesiveness can be obtained without lateral expansion and shrinkage at room temperature.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minako Aoyagi Minako Aoyagi 3 474 Tsukakoshi 3-chome, Kawasaki City, Kanagawa Prefecture 2 Asahi Glass Co., Ltd. Tamagawa Branch Office

Claims (3)

[Claims] 1. Hard foaming by mixing, spraying and foaming an active hydrogen compound having at least two functional groups containing active hydrogenation and a polyisocyanate compound in the presence of a foaming agent, a catalyst and a foam stabilizer by a spray machine. In the method for producing a synthetic resin, a piperazine-based polyether polyol obtained by reacting an alkylene oxide with a piperazine is used as at least a part of an active hydrogen compound, and water is used as a foaming agent. Manufacturing method of rigid foam synthetic resin. 2. The process according to claim 1, wherein the piperazine-based polyether polyol has a hydroxyl value of 100 to 850 mgKOH / g. 3. The method according to claim 1, wherein water is used as a foaming agent in an amount of 0.2 to 10% by weight based on all active hydrogen compounds.