JPH0246048B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing semi-rigid polyurethane foams. Currently, integrally molded products of PVC leather or PVC/ABS leather and polyurethane foam are often used as automobile interior materials. This polyurethane foam is commonly called semi-rigid polyurethane foam, and is used for crash pads, armrests, etc. However, as automobiles become lighter and competition with other materials increases, polyurethane foam products are also strongly desired to have lower density. In addition, crush pads and the like are becoming more complex in shape and thinner, and conventional systems are no longer capable of handling such problems as the shrinkage caused by closed cells (closed cells) causes uneven wrinkles on the product. . Furthermore, with the widespread use of high-pressure foaming machines, it is desired to increase the line cycle, necessitating formulations with higher reactivity, and the current situation is that the problem of shrinkage due to closed cells is being accelerated. Under such circumstances, when attempting to lower the density, simply increasing the foaming agent to form a foam will result in physical strength and strength insufficiency, resulting in closed cells and shrinkage. On the other hand, if the cross-linking agent is increased to lower the density while maintaining the physical properties, there will be a decrease in compression set, cell roughness, a bottom-up phenomenon, a decrease in elasticity, and a decrease in adhesion to PVC/ABS leather. . Furthermore, when a compound containing ethylene oxide is used as a crosslinking agent, although shrinkage is slightly prevented and elasticity and compression set are improved, mechanical strength and hardness decrease, and when mixed, it may be less compatible with polyols. Unfortunately, when a mixed solution is used, the uniform stability of the solution is poor and it separates. For this reason, relatively highly reactive amine polyols and low molecular weight triols or tetraols are sometimes used in combination, but in this case the curability is insufficient when using a high pressure foaming machine. The inventors,
As a result of intensive research to improve the above drawbacks,
We have achieved the design of a stable system that can reduce the density of foam products and support a variety of models that are becoming increasingly complex and thin. In other words, as an extension of the conventional method, there is a decrease in strength and hardness that occurs when lowering the density, shrinkage due to closed cells, compression set, decrease in impact resilience, cell roughness, bottom rising phenomenon,
We succeeded in assembling a new system by considering phenomena such as decreased adhesion to PVC/ABG leather and uniform stability of the liquid. In the present invention, a first component mainly consisting of a polyol, a crosslinking agent, water and/or other blowing agents, a catalyst, etc., and a second component mainly consisting of a polyisocyanate, etc. are reacted to form a semi-rigid material. When producing polyurethane foam, it is obtained by reacting 1 mol of dibasic acid, 1.3 to 4.5 mol of trihydric or tetrahydric alcohol, and 0 to 2 mol of dihydric alcohol as at least one component of the first component crosslinking agent. It is characterized by the use of hydroxyl group-terminated polyester. In this case, the crosslinking component is effective when used alone or in combination with other polyols, and the number of parts used can be arbitrarily determined depending on the hardness of the target foam, but preferably 100 parts by weight of the main polyol (including graft polyol). On the other hand, the amount is 10 parts by weight or less, preferably 1 to 5 parts by weight. The dibasic acids used in producing the hydroxyl-terminated polyester according to the present invention include succinic acid,
Glutaric acid, adipic acid, azelaic acid, sebacic acid, decanedioic acid, phthalic acid, isophthalic acid,
Examples include aliphatic or aromatic dibasic acids such as terephthalic acid, and examples of trivalent or tetrahydric alcohols include trimethylolpropane, trimethylolethane, 1,3,5-hexanetriol, glycerin, and pentaerythritol. Also included are two or more blended triols. In addition, examples of dihydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, xylylene glycol, cyclohexanedimethanol, etc. is used. The polyhydric alcohol is reacted with 1 mol of the dibasic acid in a ratio of 1.3 to 4.5 mol of the trihydric or tetrahydric alcohol and 0 to 2 mol of the dihydric alcohol to obtain the hydroxyl-terminated polyester of the present invention. The polyester of the present invention is obtained by a conventional polyester manufacturing method, that is, a dehydration condensation esterification reaction at 150 to 250°C. The obtained hydroxyl group-terminated polyester has, on average, a structure having 2.5 or more hydroxyl groups in one molecule as a main component. The first component polyol is, for example, a propylene oxide/ethylene oxide adduct of glycerin, trimethylolpropane, pentaerythritol, or sorbitol (EO content 10 to 20%) with a molecular weight of 5,000 to 10,000, and the graft polyol includes styrene, acrylonitrile, etc. Those having a hydroxyl value of 20 to 30 mgKOH/g can be used. Further, crosslinking agents that can be used in combination with the hydroxyl-terminated polyester of the present invention include ethylene glycol, propylene glycol, glycerin, trimethylolpropane, sorbitol, sucrose, ethylenediamine, propylene oxide adduct of triethanolamine, ethylene oxide adduct, propylene oxide-ethylene oxide. There are block and random adducts with a hydroxyl value of 200 to 1000 mgKOH/g. In addition, water and/or other blowing agents used as the first component, trichloromonofluoromethane, methylene chloride, triethylenediamine,
N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'-tetramethyl-1,3
-butanediamine, N,N,N'',N''-pentamethyldiethylenetriamine, N,N-dimethylbenzylamine, N,N,N',N'-tetramethylhexamethylenediamine, N-methylmorpholine, N- Examples include ethylmorpholine, N,N-dimethylethanolamine, and tris-
In addition to dichloropropyl phosphate and trichloroethyl phosphate, other auxiliaries such as flame retardants can also be used. Examples of the polyisocyanate used as the second component include crude diphenylmethane diisocyanate, a mixture of crude diphenylmethane diisocyanate and tolylene diisocyanate, and a mixture of crude diphenylmethane diisocyanate and pure diphenylmethane diisocyanate. The first component and the second component may be reacted by a known method for producing normal semi-rigid polyurethane foam, and the reaction ratio may be determined as appropriate depending on the purpose. By using a specific hydroxyl-terminated polyester as a component of the crosslinking agent, the semi-rigid polyurethane foam of the present invention can be made to have a lower density without deteriorating other physical properties, and is suitable for use in the automobile industry, etc. Widely available. Hereinafter, the present invention will be explained in more detail with reference to production examples and examples. Production example 1 Adipic acid 1767g, trimethylolpropane
Pour 3095g into a 54-necked flask, 150~230g
Esterification reaction was carried out while raising the temperature to 0.degree. C. and distilling off water to obtain a hydroxyl group-terminated polyester. The obtained product has a hydroxyl value of 570 mgKOH/g and an acid value of 0.2 mg.
It was KOH/g. Production example 2 Adipic acid 1927g, glycerin 552g, trimethylolpropane 2412g, propylene glycol
Using 91 g, the reaction was carried out in the same manner as in Production Example 1 to obtain a hydroxyl-terminated polyester having a hydroxyl value of 583 mgKOH/g and an acid value of 0.3 mgKOH/g. Production example 3 Using 2102g of adipic acid and 2797g of glycerin,
Reacted in the same manner as Production Example-1 to obtain a hydroxyl value of 786 mg.
A hydroxyl-terminated polyester with KOH/g and acid value of 0.5 mgKOH/g was obtained. Production example 4 Phthalic acid 872g, adipic acid 951g, trimethylolpropane 3055g, diethylene glycol 377g
G was reacted in the same manner as in Production Example-1 to determine the hydroxyl value.
A hydroxyl-terminated polyester having an acid value of 530 mgKOH/g and an acid value of 0.7 mgKOH/g was obtained. Production example 5 Adipic acid 1168g, pentaerythritol 3810
Using g, react in the same manner as in Production Example-1 to determine the hydroxyl value.
A hydroxyl-terminated polyester having an acid value of 1080 mgKOH/g and an acid value of 0.5 mgKOH/g was obtained. Examples 1 to 5, Comparative Examples 1 to 3 First component glycerin propylene oxide/ethylene oxide (85/15) adduct Molecular weight 7000 80 parts graft polyol (hydroxyl value 26 mgKOH/g)
20 parts Water 3 parts Hydroxyl-terminated polyester of Production Examples 1 to 5 5 parts Polycat 8/Polycat 12 = 3/1 (manufactured by SunApot Co., Ltd., catalyst) 1.0 part Second component Crude diphenylmethane diisocyanate (Isocyanate index 105) (Puppy) 135: Manufactured by Kasei Upjiyon Co., Ltd.) (Conditions) Mold shape 50mm x 70mm x 240mm Material Aluminum mold temperature 20-30℃ Cure Demold after 5 minutes at room temperature Stability of the first component, reactivity during free foaming and Hardness The results of measuring the physical properties of the polyurethane foam are shown in Table 1. In addition, as Comparative Examples 1 to 3, instead of the hydroxyl group-terminated polyester, a propylene oxide adduct of glycerin (G + PO molecular weight 300),
Ethylene oxide adduct of glycerin (G+EO,
(molecular weight 300) and the case of using a propylene oxide adduct of ethylenediamine (EDA+PO, molecular weight 292) are shown at the same time.

[Table] Examples 6 to 10, Comparative Examples 4 to 5 First component glycerin propylene oxide/ethylene oxide (85/15) adduct Molecular weight 7000 80 parts Graft polyol (hydroxyl value 26 mgKOH/g)
20 parts propylene oxide adduct of ethylene diamine, molecular weight 292 2 parts hydroxyl-terminated polyester of Production Examples 1 to 5 5 parts water 3 parts Polycat 8/Polycat 12 = 3/1 (catalyst manufactured by Sun Apot) 0.8 parts Second component Crude diphenyl Methane diisocyanate (Isocyanate Index 105) (Puppy 135: manufactured by Kasei Upjion Co., Ltd.) Molding conditions were the same as in Example 1. Table 2 shows the results of measuring the stability of the first component, the reactivity during free foaming, and the physical properties of the semi-rigid polyurethane foam. In addition, as Comparative Examples 4 to 5, propylene oxide adduct of glycerin (G+PO molecular weight 300) and ethylene oxide adduct of glycerin (G+EO
The case where molecular weight 300) is used is also shown.

[Table] Examples 11 to 14 Propylene oxide/ethylene oxide (85/15) adduct of first component glycerin Molecular weight 7000 80 parts graft polyol (hydroxyl value 26 mgKOH/g)
20 parts Propylene oxide or ethylene oxide adduct of glycerin Molecular weight: 300 2 parts Hydroxyl-terminated polyester of Production Examples 1 and 2 5 parts Water 3 parts Polycat 8/Polycat 12 = 3/1 (catalyst manufactured by Sun-Apot) 0.8 parts Second component Crude Diff Enylmethane diisocyanate (Isocyanate Index 105) (Puppy 135: manufactured by Kasei Upjiyon Co., Ltd.) The molding conditions were the same as in Example 1. Table 3 shows the results of measuring the stability of the first component, the reactivity during free foaming, and the physical properties of the semi-rigid polyurethane foam.

[Table] Examples 15-17, Comparative Examples 6-9 First component glycerin propylene oxide/ethylene oxide (85/15) adduct Molecular weight 7000 80 parts graft polyol (hydroxyl value 26 mgKOH/g)
20 parts ethylenediamine propylene oxide adduct;
Molecular weight 292 2 parts Hydroxyl-terminated polyester of Production Examples 1 to 3 5 parts Water 3 parts Polycat 8/Polycat 12 = 3/1 (catalyst manufactured by Sun-Apot) 2.0 parts Second component Crude diphenylmethane diisocyanate (Isocyanate index 105) ( 44V-20: Manufactured by Sumitomo Bayer Urethane Co., Ltd.) (Conditions) Mold shape 50 x 50 x 240 mm Material Aluminum Mold temperature 30℃ Cure Demoulding after 2 minutes at room temperature High-speed demolding was performed to improve curing properties and closed-cell feel ( Blisters, internal cracks, shrinkage after demolding), initial hardness, etc. were observed. The results are shown in Table 4. In addition, as a comparative example, instead of the hydroxyl group-terminated polyester, a propylene oxide adduct of glycerin (G + PO molecular weight 260),
Propylene oxide-ethylene oxide block adduct of glycerin (G+PO+EO, molecular weight
260), glycerin ethylene oxide adduct (G
+EO molecular weight 300), pentaerythritol propylene oxide adduct (PEP+PO, molecular weight
400) is used.

[Table] As shown in the examples above, by introducing hydroxyl-terminated polyester, air permeability is improved, hardness and strength can be maintained without foam shrinkage, and the density can be lower than that of conventional molded products. succeeded in.

Claims (1)

[Claims] 1 Polyol, crosslinking agent, water, and/or
When producing a semi-rigid polyurethane foam by reacting a first component mainly containing other blowing agents, catalysts, etc. with a second component mainly containing polyisocyanate, at least one of the crosslinking agents in the first component is Ingredients: 1 mol of dibasic acid, 1.3 to 4.5 mol of trihydric or tetrahydric alcohol, 0 to 2 mol of dihydric alcohol
A method for producing a semi-rigid polyurethane foam characterized by using a hydroxyl-terminated polyester obtained by reacting moles.