JPS60240416A - Shortening of mold removing time - Google Patents

Abstract

PURPOSE:To shorten time for removing a refrigerator shell and its doors from molds by adding special organic amine compound as catalyzer when hard urethane foam is expanded and hardened. CONSTITUTION:When hard urethane foam original solution is injected into a refrigerator shell and doors and expanded. In this case, since, when organic amine compound shown by a general formula (1) is added as catalyzer, the hardness of urethane foam in time of foaming and hardening is increased fast and therefore strength of foam is enlarged promptly the molds can be removed in a short time even if foaming pressure is high. N,N',N''-tris (dimethyl aminopropyl) hexahydro-S-triazine, N,N',N''-tris (diethyl amino butyl)hexahydro-S-triazine can be illustrated as the organic amine compound by the general formula (1). These catalyzers are used singly or in combination and the suitable amount of use is 0.3-3.0pts.wt. to active hydrogen of 100pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of insulating refrigerator shells and doors, and more particularly to a method of injecting hard urethane 7 ohm into refrigerator shells and doors.

Rigid urethane foam has excellent insulation properties, so it is widely used as insulation material for electric refrigerators, gas refrigerators, panels, houses, warehouses, equipment, storage tanks, etc.. A commonly used method is to

When hard urethane foam is foamed and cured, it generates a foaming pressure of several kilograms per square centimeter, causing blistering on the object being constructed, so the outside is reinforced with a jig during work - especially for refrigerator outer shells and doors. In some cases, extremely thin metal plates or synthetic resin plates are used, and dimensional accuracy is required for the finished product. Therefore, the mold used as the jig requires not only accurate shape and robustness but also a complicated opening/closing mechanism suitable for mass production, making it extremely expensive.

In addition, the molding time is long, for example, when foaming the outer shell of a refrigerator, it takes about 10 minutes to insert the urethane stock solution into the mold and remove it from the mold after one foaming is completed (demolding). ing. On the other hand, when manufacturing doors such as insulation panels using the injection foaming method, demolding time may range from several tens of minutes to several hours.

Recently, there has been an increasing demand for shortening demolding time in order to increase production by simply increasing the rotation rate of molds without increasing the number of extremely expensive molds.

As a result of various studies to solve this problem, the present inventors discovered that a special catalyst system was effective and arrived at the present invention.

That is, the present invention uses the general formula % formula % () as a catalyst when injecting and foaming a hard urethane foam stock solution into the refrigerator outer shell and doors as follows. A method for shortening demolding time for refrigerator shells and doors, characterized by adding an organic amine compound represented by an alkyl group.

According to the present invention, the hardness of the urethane foam increases quickly during foaming and curing, and therefore the strength of the -C foam develops quickly, so demolding is possible in a short time even at high foaming pressure.

In the general formula of the present invention, the alkylene group represented by X is, for example, t, ethylene, propylene, or butylene;
-propyl, butyl, i-butyl, tert-butyl,
These include pentyl and hexyl groups. The organic amine compound represented by general formula (1) is, for example, N, N', N'-
) lis(dimethylaminopropyl)hexahydro-s-
triazine, N, N'N'-tris(diethylaminoethyl)hexahydro-s-triazine, N, N',
N'-)lis(diethylaminoethyl)hexahydro-5-triasif, N,N',N'-)lis(diethylaminobutyl)hexahydro-3-)lyazine, and the like.

These catalysts may be used alone or in combination, and the appropriate amount to be used is 0.3 to 3.0 parts per 100 parts by weight of the active hydrogen-containing compound shown below (in the present invention, parts indicate parts by weight). be. These catalysts also contain the organometallic compound No. 31, which is commonly used as a catalyst in the production of 7-ohm urethanes.
It can also be used in combination with one or more fIJ amines. Typical examples of these organometallic compounds include potassium acetate, potassium octoate, potassium oleate, sodium propionate, sodium octoate, lead octoate, lead oleate, diptyltin zinc phosphate, lead octoate, and naphthene. Such as acid lead.

Typical tertiary amines include triethylenediamine, triethylenediamine formate, methyl (triethylenediamine), tetramethylhexamethylenediamine, tetramethylpropylenediamine, N-ethylmorpholine, N-methylmorpholine, N,N-dimethylcyclohexylamine, bis(dimethylaminoethyl)ether, pentamethyldiethylenetriamine,
Diethylethanolamine, dimethylethanolamine, etc.

The monourethane foam stock solution used in the present invention is composed of an active hydrogen-containing compound, an organic polyisocyanate, a blowing agent, a foam stabilizer, the above-mentioned catalysts, and, if necessary, a flame release agent and other auxiliaries.

Active hydrogen-containing compounds include, for example, water, ethylene glycol, glopylene glycol, diethylene glycol, triethylene glycol, diethylene glycol, glycerin, trimethylolpropane* 1.3.6-hexandriol, pentaerythritol, sorbitol, sucrose, bisphenol A1 Polyhydric alcohols such as novolac, hydroxylated 1,2-polybutadiene, hydroxylated 1,4-polybutadiene, etc., and/or hydroxyl value ioo ~ 800 mg KOH/H obtained by addition polymerizing alkylene oxide to these polyhydroxy compounds
It is a polyether polyol. , matagetanolamine, triethanolamine, and other alkanolamines
Compounds containing two or more active hydrogens such as ethylene diamine, diethylene triamine, ammonia, aniline, tolylene diamine, xylylene diamine, diaminodiphenylmethane and/or these amines, ethylene oxide, propylene oxide, butylene oxide, styrene. Polyether polyols and polytetramethylene ether glycols with hydroxyl values of 100 to 800 mg KOH/g obtained by addition polymerization of oxide etc. can also 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.

Further, polymer polyols obtained by grafting ethylenically unsaturated compounds such as styrene, acrylonitrile, and methyl methacrylate onto the above-mentioned known polyether polyols or polyester polyols, 1.2- or 1.4-polybutadiene polyols, or these. Hydrogenates can also be used. The organic polyisocyanate used in the present invention, which uses one type or a mixture of two or more of these active hydrogen-containing compounds, is, for example, 2.
4- and 2.6-1 lylene diisocyanate and mixtures thereof, as well as crude tolylene diisocyanate containing polynuclear bodies thereof, 4.4'-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate called crude diphenylmethane diisocyanate, etc. It is.

In the present invention, a blowing agent and a foam stabilizer are used to form a wire foam.The blowing agent includes water, trichloromonofluoromethane (
The foam stabilizer in the present invention uses one or more of the following: Koyo's organosilicon surfactant, for example, L-501 manufactured by Nippon Unicar Co., Ltd.
L-520, L-532, L-540, L-544, L
-3550, L-5302, L-5305, L-532
01L-5340, L-5350, L-5410゜L-
5420, L-5710, L-5720, etc., 5H-190, SH-192, manufactured by Toray Silicone Co., Ltd.
5H-193, 5H-194, 5H-195, 5H-2
00,5RX-253 etc., F-114, F-121, F-122, F-220 manufactured by Shin-Etsu Silicone Co., Ltd.
F-230, F-258, F-260B1 F-305
, F-306, F-317, F-341, F-601,
F-606, X-20-200, X-20-201, etc.; TFA-4200,
FA-4202, etc.

Also, as a flame retardant, for example, tris(2-chloroethyl)
Phosphate, tris(dichloroglovir) phosphate, tris(dibromoglovir) phosphate, Oiri Chemical Co., Ltd. CR-505 and CR-507, Monsanto Chemical Co., Ltd. Phosgard 2X C-20 and C-22
-R1 Fyro 16 manufactured by Stoffer Chemical Co., Ltd., etc. can be used.

Other plasticizers, fillers, stabilizers, colorants, etc. may be added as necessary.

To carry out the present invention, a resin solution is prepared by mixing predetermined amounts of an active hydrogen-containing compound, a catalyst 1 blowing agent, a foam stabilizer, a flame retardant, and other auxiliaries.

Using a polyurethane foaming machine, the resin liquid and organic polyisocyanate are continuously and rapidly mixed at a fixed ratio. The obtained hard urethane foam stock solution is immediately injected between the inner and outer drawing boards of a refrigerator outer shell or door fixed in a mold, and is foamed and hardened. At this time, the flow rate ratio of the resin liquid and the organic polyisocyanate is adjusted so that the equivalent ratio of the organic polyisocyanate to the active hydrogen-containing compound is 0.8-3.0.

If left for 3 to 7 minutes after pouring, the hardness of the hard urethane 7 ohm will increase sufficiently, so open the mold and take it out. After demolding, no changes such as swelling or warping occur on the outer shell or door.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples.

Example 1 - % Mukumu "tl:, comparison l/ Hydroxyl value 420 mgKOH/g, viscosity 9.50 obtained by addition polymerization of alkylene oxide to sucrose and triethanolamine as an active hydrogen-containing compound
Using polyol B1 at 0 cps/25°C or polyol D with a hydroxyl value of 400 mg KOR/H obtained by addition polymerizing alkylene oxide to Shefrose and humanlylene diamine, organic methane diincyanate (M
The results obtained using DI-CR) are shown in Table 1.

As a catalyst, N,N',N'-tris(dimethylaminopropyl)hexahydro-5-triazine (P
o1y-41) and tetramethylhexamethylenediamine (TMHDA'), and fluorotris(2-chloroethyl)phos,%-(TCEP) as a flame retardant.
It was used. Furthermore, the organosilicon surfactant 5H-193 was used as a foam stabilizer, and water and trichloromonofluoromethane (F-11A) were used as blowing agents.

The above raw materials were blended according to the formula shown in Table 1, and free foaming by hand mixing and injection foaming using a foaming machine were performed.

The reactivity was measured by free foaming, and the hardness was measured by measuring the surface hardness of the free foamed foam at regular intervals using a Type F hardness meter. The foam temperature was also measured using a thermometer inserted into the free foam foam. The foaming pressure was measured by attaching a strain gauge near the center of the mold and interposing a polyethylene film to the urethane foam.

The low-temperature dimensional stability of 7 ohms was determined by measuring the dimensional change rate after being left at -30°C for 24 hours, and the high-temperature dimensional stability was measured at 110°C and 24 hours.
The dimensional change rate after being left for 4 hours was measured.

As is clear from Table 1, N; N', N' -)
When only lith(dimethylaminopropyl)hexahydro-S- was used, the demolding time was shortened and the general physical properties of 7 ohms were not adversely affected.

(Margin below)

Claims (1)

[Claims] When injecting and foaming a hard urethane 7-ohm stock solution into the outer shell and doors of a refrigerator, the general formula % formula % is used as a catalyst. However, X is an alkylene group of 02-4 R is an alkyl group of 01-6 A method for shortening demolding time of refrigerator shells and doors, characterized by adding an organic amine compound represented by: