JPS6399245A - Production of integrally molded polyurethane foam article - Google Patents

Abstract

PURPOSE:To obtain the titled molded article free from discoloration in heating and suitable as an interior part for automobile, e.g. crush pad, etc., by injecting a foamable mixture composed of a polyol, an epoxidized fatty acid ester, an isocyanate component, etc., into a skin made of a chlorine-containing resin. CONSTITUTION:A foamable mixture composed of a polyol (e.g. polyether polyol having a molecular weight or 800-12,000), a crosslinking agent (e.g. diol having a molecular weight of 62-500), a catalyst, an additive, an epoxidized fatty acid ester which is an epoxidized product of vegetable fatty acid alkyl ester and an isocyanate component (e.g. tolylene diisocyanate) is injected into a surface skin produced by molding a chlorine-containing resin (e.g. polyvinyl chloride). The amount of the epoxidized fatty acid ester is preferably 1-65pts.wt., especially 3-60pts.wt. per 100pts.wt. of the polyurethane foam.

Description

[Detailed Description of the Invention] [Field of Industrial Application] Polyurethane foam integrally molded products are mainly composed of a soft vinyl chloride resin skin and polyurethane foam, and are used as automobile interior parts such as crash pads, instrument panels, headrests, and console boxes. It is used.

[Prior art and problems] Such polyurethane foam integrally molded products are produced by loading a soft vinyl chloride resin skin obtained by powder slush molding into a metal lower mold, and forming a foamable polyurethane foam product consisting of a polyol component and an isocyanate component. It is manufactured by a method in which the mixture is injected into the epidermis, the upper mold is closed, and the mold is removed after the urethanization reaction and foaming are completed.

If a car is left in the hot sun for a long time with the windows closed, the surface of crash pads, etc. can reach temperatures of over 100°C. Under these conditions, the outer skin material and the urethane foam inside will gradually turn brown. It may become discolored.

This tendency is particularly noticeable when the molded article is exposed to temperatures of 110° C. or higher.

In order to solve this problem, there is a method of blending phosphorus-based compounds into polyurethane raw materials, which is disclosed in Japanese Patent Application Laid-Open No. 60-2011.
2114, etc.

Although such improvements were effective for a certain amount of time, the effects were insufficient for a long time.

[Structure of the Invention] The present invention provides a polyurethane product characterized in that a foamable mixture consisting of a polyol, a crosslinking agent, a catalyst, an additive, an epoxidized fatty acid ester, and an isocyanate component is injected into a skin molded from a chlorine-containing resin. This relates to a method for producing a foam integrally colored product.

Furthermore, it relates to an epoxidized fatty acid ester used in the above method.

Polyol components used in the present invention include polyols,
It consists of catalysts, additives, etc. Examples of polyols include polyether polyols with a molecular weight of 800 to +2000, and such polyether polyols such as styrene,
A polymer polyol in which a polymerizable monomer such as acrylonitrile and a nil monomer are graft-polymerized, or a polymer of these polymerizable monomers or an organic substance such as a polyurea compound is dispersed therein is used.

As a crosslinking agent, a diol having a molecular weight of 62 to 500,
Triols, as well as polyfunctional polyols, alkanolamines, polyamines, and the like are used.

As additives, water, foaming agents such as trichloromonofluoromethane and methylene chloride, and flame retardants such as phosphorus compounds are used.

Isocyanate components include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylisocyanate, chemically modified versions of these polyisocyanates, reactants of these isocyanate compounds with polyols, etc., or mixtures of these isocyanates. is used.

As the chlorine-containing resin for the skin material, polyvinyl chloride, vinyl chloride copolymer, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, etc. are used.

The epoxidized fatty acid esters used in the present invention are mainly unsaturated higher fatty acids obtained by hydrolyzing vegetable oils, monoalcohols such as methanol, ethanol, propatool, butanol, pentanol, hexanol, and octatool, and ethylene glycol. , propylene glycol, hexanediol, trimethylolpropane, and other polyhydric alcohols, and further oxidation.

As the vegetable oil, soybean oil, linseed oil, cottonseed oil, castor oil, rapeseed oil, etc. are used.

These epoxidized fatty acid esters can be dissolved in advance in the polyol component or isocyanate component, or can be added to the reaction system simultaneously with the urethanization reaction.

The amount of the epoxidized fatty acid ester added is 1 to 65 parts by weight, preferably 3 to 60 parts by weight, per 100 parts by weight of the polyurethane foam. If it is less than 1 part by weight, the effect on heat discoloration of the skin material is insufficient, while if it is more than 65 parts by weight, although it is effective in preventing heat discoloration of the skin material, the resulting polyurethane foam tends to shrink.

[Examples and Comparative Examples 100 parts of a polyether polyol with an OH value of 28 mgKOH/g, which is obtained by adding ethylene oxide and propylene oxide to trimethylolpropane, 1 part of triethanolamine, and an ethylene oxide adduct of ethylene diamine (
OH value 480 OH/g) 2 parts, water 2.5 parts,
An epoxidized product of linseed oil fatty acid butyl ester (hereinafter referred to as stable injection) (ADK CIZERD) was added to a mixture consisting of 0.3 parts of triethylenediamine.
-178) (equivalent to 3.13.26 parts by weight for 100 parts by weight of polyurethane foam), or epoxidized rapeseed oil fatty acid octyl ester (CIZERD-5 in Adeka Argus i1 AD).
5) 40 or 70 parts (corresponding to 26.49 parts by weight per 100 parts of polyurethane foam) (hereinafter referred to as stabilizer B) was added. The mixture was uniformly mixed using a screw type stirrer (approximately 200 Or yen + m) to obtain a polyol component.

A polyvinyl chloride skin material molded into the shape of an instrument panel using the powder slush molding method was placed on the aluminum lower mold, and an ABS resin plate was attached to the aluminum upper mold.
Heated to 0-50°C.

The polymethylene polyphenylisocyanate and the polyol component were mixed so that the isocyanate index was 100, and the mixture was stirred with a screw type (n < about 200 Orpm).
After stirring for about 10 seconds, the foam was poured into the skin material so that the overall density of the foam was about 0.153/cm''.

After 10 minutes, the mold was removed to obtain an integrally molded three-layer structure consisting of polyvinyl chloride skin/polyurethane foam/ABS resin plate. The surface hardness (Asker-C) of the polyurethane foam thus obtained was approximately 36.

From this integrally molded product, it measures 5cm long, 5cm wide, and 2cm thick.
A sample containing a polyvinyl chloride skin and polyurethane foam was cut out and heated in a gear oven at 110°C. After 100 hours, 200 hours, and 350 hours, the samples were taken out from a 5M color computer (Suga Test 8!
The color difference value (ΔE) of the polyvinyl chloride skin after heating was measured using the color tone before heating as a reference.

The results are shown in Table 1.

As a comparative example, a case where no epoxidized vegetable oil was added and a case where a phenol novolac type trifunctional epoxy resin (
20 parts of Sumiepoxy A-120 (hereinafter referred to as stabilizer C) manufactured by Sumitomo Chemical Co., Ltd. (equivalent to 13 Niffi parts for 100 parts by weight of polyurethane foam) or 20 or 40 parts of triphenyl phosphite (hereinafter referred to as stabilizer). (equivalent to 13.26 parts by weight based on 100 ffi parts of polyurethane foam) was added, and an integrally molded product was obtained in the same manner as in the example.

A heating test was conducted on the sample in the same manner as in the example, and the results are shown in Table 2.
Shown below.

Table 1 Table 2 [Effects of the present invention] As is clear from the Examples and Comparative Examples, the integrally molded product made of a polyurethane foam containing an epoxidized product of vegetable oil fatty acid alkyl ester and a chlorine-containing resin has no discoloration of the skin that occurs when heated. few.

Patent applicant: Sumitomo Bayer Urethane Co., Ltd. Procedural amendment (voluntary) 1. Display of the case 1985 Patent Jaw No. 246195: 3. Person making the amendment (1) “Epoxidized vegetable oil η” on page 7, line 19 of the specification
・"Epoxidized product of vegetable oil fatty acid alkyl ester"
This is a correction.

Claims (1)

[Claims] 1. An integrated polyurethane foam characterized in that a foamable mixture consisting of a polyol, a crosslinking agent, a catalyst, an additive, an epoxidized fatty acid ester, and an isocyanate component is injected into a skin molded from a chlorine-containing resin. Method of manufacturing molded products. 2. The method for producing an integrally molded polyurethane foam product according to claim 1, wherein the epoxidized fatty acid ester is an epoxidized product of a vegetable oil fatty acid alkyl ester. 3. Epoxidized fatty acid ester used when producing an integral molded article by injecting a foamable mixture consisting of a polyol, a crosslinking agent, a catalyst, an additive, and an isocyanate component into a skin molded from a chlorine-containing resin.