JPH01259019A - Production of rigid polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain the subject foam useful for heat insulating material of refrigerator, etc., having excellent dimensional stability at low temperature and compression strength by using dichlorotrifluoroethane as a foaming agent and a specific polyether polyol for polyol. CONSTITUTION:In a production of aimed foam from (A) organic polyisocyanate, (B) polyol, (C) foaming agent, (D) catalyst and (E) surfactant and other auxiliary, dichlorotrifluoroethane is used as component C and polyether polyol obtained by adding (ii) alkylene oxide to (i) aliphatic amine (e.g., triethanolamine) and/or aromatic amine (e.g., tolylenediamine) is used as component B. 30-100pts.wt. the polyether polyol is used to 100pts.wt. component B.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing rigid polyurethane foam.

More specifically, the present invention relates to a method for producing rigid polyurethane foam with excellent low-temperature dimensional stability and compressive strength using dichlorotrifluoroethane (commonly known as R-123) as a blowing agent.

[Prior Art] Rigid polyurethane foam has excellent heat insulating properties and low-temperature dimensional stability, so it is widely used as a heat insulating material for refrigerators, freezers, etc.

The main reason for this is that trichlorofluoromethane (commonly known as R-11), which has excellent heat insulation properties, is used as a blowing agent when producing rigid polyurethane foam.

(Problem to be Solved by the Invention) However, in recent years, in order to protect the earth's ozone layer, regulations on chlorofluorocarbons have been considered and are about to be implemented in the near future.

This regulation also includes trichlorofluoromethane (R-11), which has been used as a blowing agent for rigid polyurethane foam.

Therefore, there is an urgent need to develop a blowing agent for rigid polyurethane foam that can replace trichlorofluoromethane (R-11).
R-123) is considered a potential replacement.

However, when dichlorotrifluoroethane (R-123) is used as a blowing agent, compared to the foam foamed using conventional trichlorofluoromethane (R-11), (i) the initial reactivity is significantly slower; ) There are many problems such as a decrease in foaming efficiency, and c) a significant deterioration of the foam physical properties such as low-temperature dimensional stability and compressive strength, making it impossible to obtain a satisfactory foam using conventional methods for manufacturing rigid urethane foam. The present inventors have confirmed this.

Therefore, when using dichlorotrifluoroethane (R-123), in order to have the same foam properties such as low-temperature dimensional stability and compressive strength, it is necessary to make the density considerably higher, and the insulation properties are worse than before. However, a practically satisfactory form could not be obtained due to the increase in cost.

[Means to solve the problem]

In order to overcome the above-mentioned problems, the present inventors have conducted intensive studies and found that as a blowing agent for rigid polyurethane foam,
A method for producing rigid polyurethane foam without sacrificing conventional excellent heat insulation properties and low-temperature dimensional stability even when dichlorotrifluoroethane (R-123) is used instead of conventionally used R-11. They discovered this and arrived at the present invention.

That is, the present invention provides a method for producing rigid polyurethane foam from an organic polyisocyanate, a polyol, a blowing agent, a catalyst, a surfactant, and other auxiliary agents.
A polyether polyol obtained by using dichlorotrifluoroethane as a blowing agent and adding an alkylene oxide to an aliphatic and/or aromatic amine as a polyol is added in an amount of 30 to 1 part by weight per 100 parts by weight of the total polyol.
00 parts by weight of a rigid polyurethane foam.

When dichlorotrifluoroethane (R-123) is used in place of the conventionally used R-11, the method of the present invention provides for the first time a hard material with excellent heat insulation properties, low-temperature dimensional stability, and compressive strength. Polyurethane foam is produced.

Specific compounds of the polyether polyol (hereinafter abbreviated as amine-based polyether polyol) obtained by adding alkylene oxide to aliphatic and/or aromatic amine used in the present invention include jetanolamine, triethanolamine, alkanolamines such as ethylenediamine, diethylenetriamine, ammonia, triethylenediamine, trimethyldiethylenetriamine,
and one or a mixture of two or more aliphatic amine compounds such as polyethertriamine, and aromatic amine compounds such as tolylene diamine, diaminodiphenylmethane, naphthalene diamine, diethyltolylene diamine, and t-butyltolylene diamine. A polyether polyol having a hydroxyl value of 200 to 1000 mg 100 O/g, preferably 350 to 800 a+gKOH/g, obtained by addition polymerizing alkylene oxide to a species or a mixture of two or more species, can be used.

Examples of alkylene oxide include ethylene oxide,
Propylene oxide, butylene oxide, etc. are used.

Dichlorotrifluoroethane (R-1
23) also eliminates the initial reactivity delay and produces a rigid polyurethane foam with excellent foam properties such as low-temperature dimensional stability and compressive strength.

The amount of amine-based polyether polyol is 30 parts by weight or less (
(based on 100 parts by weight of the total polyol), the initial reactivity becomes significantly slow, the foaming efficiency decreases, and the foam properties such as low-temperature dimensional stability and compressive strength deteriorate.

Moreover, when the amine-based polyether polyol exceeds 100 parts by weight, the reactivity is too fast and it is not suitable for producing rigid polyurethane foam.

Examples of the polyols used in the present invention include ethylene glycol, propylene glycol, diethylene glycol,
Triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, l, 3,6-hexanetriol, pentaerythritol, sorbitol, sucrose, bisphenol A, novolac, hydroxylated 1,2-polybutadiene, hydroxylated 1
．． Hydroxyl number 200-800 obtained by addition polymerizing alkylene oxide to polyhydric alcohols such as 4-polybutadiene and/or these polyhydroxy compounds
■Polyether polyol with KOH/g can be used.

In addition to the above, there are also higher fatty acid ester polyols, polyester polyols obtained by reacting polycarboxylic acids with low molecular weight polyols, polyester polyols obtained by polymerizing caprolactone, and higher fatty acid esters containing OH groups such as castor oil and dehydrated castor oil. Can be used.

The organic polyisocyanates used in the present invention include conventionally known organic polyisocyanates, and are not particularly limited. Diisocyanate, crude diphenylmethane diisocyanate, tolylene diisocyanate, crude tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate ,
Triphenylmethylene triisocyanate, tolylene triisocyanate, modified (carposidiimide etc.)
NGO-terminated prepolymers (NCO content, e.g. 5 to 35%) obtained by reacting diphenylmethane diisocyanate, etc. and mixtures thereof and excess amounts of these polyisocyanates with polyols (e.g. low molecular weight polyols/or polymer polyols) etc.

These isocyanates may be used alone or in combination of two or more. The amount used is such that the equivalent ratio of NGO groups to active hydrogen in the resin liquid is 0.8 to 5.0.

Catalysts that can be used in the present invention include, for example, amine-based urethanization catalysts (triethylamine, tripropylamine,
Triisopropaturamine, tributylamine, trioctylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, jetanolamine, triethanolamine, N-methylgetanol Amine, N,N-dimethylethanolamine, diethylenetriamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N.

N', N'-tetramethylbutanediamine, N.

N,N',N"-tetramethyl-1,3-butanediamine, N,N,N',N'-tetramethylhexamethylenediamine, bis(2-(N,N-dimethylamino)ethyl]ether , N,N-dimethylbenzylamine, N,N-dimethylcyclohexylamine, N,N,N
"N', N"-pentamethyldiethylenetriamine,
Triethylenediamine, formates and other salts of triethylenediamine, oxyalkylene adducts of amino groups of primary and secondary amines, azacyclic compounds such as N,N-dialkylpiperazines, various N,N',N '''-Trialkylaminoalkylhexahydrotriazines, (β-aminocarbonyl catalyst of Japanese Patent Publication No. 52-43517,
β-aminonitrile catalyst of Special Publication No. 53-14279)
, organometallic urethanation catalysts (tin acetate, tin octylate,
tin oleate, silver laurate, dibutyltin diacetate, dibutyltin dilaurate, diptyltin dichloride,
lead octoate, lead naphthenate, nickel naphthenate, cobalt naphthenate, etc.).

These catalysts are used alone or in combination, and the amount used is 0.0001 to 1 per 100 parts of the compound having active hydrogen.
It is 0.0 part.

The foam stabilizer in the present invention is a conventionally known organosilicon surfactant, such as L-501 manufactured by Nippon Unicar Co., Ltd.
, L-520, L-532, L-540, L-544
, L-3550, L-5302, L-5305, L-5
320, L-5340, L-541 (1, L-5420
, L-5710゜L-5720, etc., and 5H-190, 5H-192, 5H-1 manufactured by Toray Silicone Co., Ltd.
93,5H-194,5H-195,5H-200,5
RX-253, etc., and F-1 manufactured by Shin-Etsu Silicone Co., Ltd.
14, F-121, F-122, F-220, F-23
0, F-258, F-260B, F-305, F-3
06, F-317, F-341, etc., and TFA-4200, TFA-4202 manufactured by Toshiba Silicone Co., Ltd.
etc.

The amount of these foam stabilizers used is 0.1 to 2 parts per 100 parts of the total of the compound with active hydrogen and the organic polyisocyanate.
It is 0 copies.

In addition, as a flame retardant, for example, tris(2-chloroethyl)
Phosphate, tris (dichloropropyl) phosphate, tris (dibromopropyl) phosphate, Ohe Chemical Co., Ltd. CR-505 and CR-507, Monsanto Chemical Co., Ltd. Phoogard 2X C-20 and C-22-
Pyrol 6 manufactured by Stouffer Chemical Co., Ltd., etc. can be used.

Plasticizers, fillers, stabilizers, colorants, etc. can be added as necessary.

To carry out the present invention, predetermined amounts of a polyol, a catalyst, a blowing agent, a foam stabilizer, a flame retardant, and other auxiliary agents are mixed to form a resin liquid.

Using a polyurethane foaming machine, the resin liquid and polyisocyanate are continuously and rapidly mixed at a fixed ratio.

The resulting rigid polyurethane foam stock solution is injected into the cavity or mold. At this time, the flow rate ratio of the resin liquid and the polyisocyanate is adjusted so that the equivalent ratio of the organic polyisocyanate and the active hydrogen-containing compound is 0.8 to 5.0.

After injection, the rigid polyurethane foam will expand and harden within a few minutes.

The rigid polyurethane foam obtained by the present invention can be used as a heat insulating material or structural material for electric refrigerators, heat insulating panels, ships, vehicles, etc.

〔Example〕

The present invention will be specifically explained below with reference to Examples.

In the examples, the raw materials used are as follows. In addition, parts indicate parts by weight.

MDI-CR; Crude diphenylmethane diisocyanate manufactured by Mitsui Toatsu Chemical ■ N00% 31.0; H'J, t-Jl/A; Shot J! /Propylene oxide added to glycerin, hydroxyl value 400 ■KOH/g polyether polyol Boliol B; C=+tJ! /Polyether polyol C with a hydroxyl value of 400 KOH/g obtained by adding propylene oxide to water Polyol C; Amine-based polyether polyol with a hydroxyl value of 400 KOH/g obtained by adding propylene oxide to tolylene diamine/triethanolamine .

Polyol D: Amine-based polyether polyol with a hydroxyl value of 480 KOH/g, made by adding ethylene oxide to trimethyldiethylenetriamine Polyol E: Amine-based polyether polyol with a hydroxyl value of 560 KOH/g, made by adding propylene oxide to triethanolamine Agent: L-5420 catalyst manufactured by Nippon Unicar ■:
Minic made by sticky material ■.

TMHD (Tetramethylhexanethylenethia) Blowing agent R-123i Dichlorotrifluoroecurine F-123 (trade name) manufactured by Mitsui DuPont Fluorochemical ■ R-11, Trichlorofluoromethane F-11 (manufactured by Mitsui DuPont Fluorochemical ■) (Product name) (Examples 1 to 6 and Comparative Examples 1 to 4) A resin solution with the composition shown in Table 1 was prepared, and this was rapidly and rapidly mixed with crude diphenylmethane diisocyanate at 5000 rpm for 8 seconds to determine the dimensions. 2
The mixture was immediately poured into a vertical wooden box measuring 00 x 200 x 200 mm and allowed to foam freely.

It foams and hardens within a few minutes after injection, yielding a rigid polyurethane foam.

The obtained Polyurekne foam was measured for its low-temperature dimensional stability, that is, the dimensional change rate and compressive strength when stored at -30°C for 24 hours.

〔Effect of the invention〕

From Table 1, in the conventional manufacturing method (comparative example), when dichlorotrifluoroethane (R-123) was used as a blowing agent (comparative examples 2 and 4), trifluoromethane (R-
11) (Comparative Examples 1 and 3), the dimensional change rate and compressive strength are inferior.

However, in Examples 1 to 6 according to the method of the present invention, compared to the conventional method, R
-11 (Comparative Examples 1 and 3), the same physical properties as the dimensional change rate and compressive strength were obtained.

Patent Applicant: Mitsui Toatsu Chemical Co., Ltd. Proceeding Officer (Spontaneous) July 8, 1988 Director General of the Patent Office Yoshi 1) Moon Yi 1, Indication of the Case 1988 Patent Application No. 87201 2, Invention Name: Rigid polyurethane foam manufacturing method 3, relationship with the amended case Patent applicant address: 3-2-5 Kasumigaseki, Chiyoda-ku, Tokyo Name (31
2) Mitsui Toatsu Chemical Co., Ltd. 4. “Detailed Description of the Invention” column of the specification to be amended 5. Contents of the amendment

Claims (3)

[Claims] (1) A method for producing rigid polyurethane foam from an organic polyisocyanate, a polyol, a blowing agent, a catalyst, a surfactant, and other auxiliaries, in which dichlorotrifluoroethane is used as the blowing agent, and aliphatic and A method for producing a rigid polyurethane foam, which comprises using 30 to 100 parts by weight of a polyether polyol obtained by adding alkylene oxide to/or an aromatic amine, based on 100 parts by weight of the total polyol. (2) The method for producing a rigid polyurethane foam according to claim 1, wherein the aliphatic amine is triethanolamine and/or trimethyldiethylenetriamine. (3) Claim 1 wherein the aromatic amine is tolylene diamine.
The method for producing the described rigid polyurethane foam.