JPS5918723A - Skin-forming agent for preparation of urethane foam having skin layer - Google Patents

Abstract

PURPOSE:To provide the titled skin-forming agent having excellent solvent resistance and mold releasability, and consisting of a two-pack urethane solutions composed of an OH-terminaed urethane prepolymer obtained by the reaction of an aliphatic polyisocyanate with excess polyol, and an aliphatic polyisocyanate. CONSTITUTION:The titled skin-forming agent for urethane foam is non-yellowing tow-pack urethane solutions composed of (A) an OH-terminated urethane prepolymer obtained by the reaction of (i) an aliphatic polyisocyanate (e.g. hexamethylenediisocyanate) with (ii) excess polyol (e.g. a mixture of high-molecular polyol and low-molecular polyol) and having an OH-equivalent of preferably 2,000-10,000 and (B) an aliphatic polyisocyanate composition wherein at least a part of the polyisocyanate contains preferably >=3NCO groups. The ratio of NCO in the component A to the OH in the component B is preferably 1-3. USE:Interior and exterior material for automobile, train, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a skin-forming agent for urethane foam with a skin (hereinafter abbreviated as skin foam), and more particularly to a skin-forming agent for mold-coating skin foam. Conventional skin forms include integral skin form (self-skin form), mold coat method skin form, and the like. Coating agents (skin-forming agents) used in MoltCo-1 method skin foam include non-yellowing powder-type linear polyurethane solutions, two-component urethane stock solutions, combinations thereof, and non-yellowing corrugated linear polyurethane solutions. Combinations with polyisocyanates have been proposed, but those using non-yellowing, wave-type linear polyurethane solutions have problems with solvent resistance, and conventional two-part urethane stock solutions cannot be used as surface layers. The ones used for this have low initial strength and the surface layer easily breaks during demolding (brittle).

It has drawbacks such as long demolding time, and is not practically satisfactory.

As a result of repeated research to find a skin forming agent for coating method Skinoff 9 ohm, it was discovered that the above object could be achieved by using a specific two-component urethane solution as a skin forming agent, and the present invention was achieved.

That is, the present invention provides an OH-terminated urethane prepolymer (
This is a skin-forming agent for a mold-coated urethane foam with a skin formed by a non-yellowing two-component urethane solution consisting of a) and an aliphatic polyisonoanate ('b).

In the present invention, the aliphatic polyisonoanate used in the production of the OH-terminated urethane prepolymer (a) contains all N
to polyisocyanates 1 in which the CO group is bonded to a non-aromatic hydrocarbon atom, such as aliphatic polyisocyanates having 2 to 12 carbon atoms (excluding the carbon in the NGO group), and 4 to 15 carbon atoms; cycloaliphatic polyisocyanate, carbon number 8.
-12 aromatic aliphatic polyisocyanates and modified products of the first polyisonoanate (modified products containing a carposiimide group, a uretdione group, a uretimine group, a urea group, a hyuret group, and/or an inocyanurate-1 group) etc.) can be used.

Examples of such polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate (MDI).

Dotecamethylene isocyanate, 1,6,11-Usidedecane-1-liisocyanate-1-,2,2,4-1-limethylhexane-isocyane-1-. Lysine diisocyanate h, 2.6*isocyane 1-1 methyl caproate,
His(2-isocyanatoethyl) fumarate, His(
2-Isocyanate ethyl) carbonate, 2-Isocyanate ethyl-2,6-dioxy-un-hexanoate 4-isopho-isocyan-isocyanoate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated HDI)
, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate +- (hydrogenated TD engineering), bis(
2-Isocyanatoethyl) 4-cyclohecan-1,
2-dicarboxylate; xylylene diisocyanate.

Examples include water-denatured products of diethylbenocene diisocyanito-HDI, trimerized products of IPDI, and mixtures of two or more thereof. Preferred among these are MDI, IPDI and hydrogenated HDI.

Polyols used in the production of the OH-terminated urethane prepolymer (a) include low-molecular polyols (trifunctional polyols such as ethylene glycol, propylene glycol, 1,4 phthanodiol, diethylene glycol, and cyclohexylenoglycol; glycerin, tosmethylolpropane, trifunctional or higher functional polyols such as pentaerythritol, solhitol, and nurose); high-molecular polyols such as polyether polyols [the above-mentioned low-molecular polyols, polyhydric phenols (bisphenols such as bisphenol A, etc.) and/or Amines (
Alkanolamines such as 1-liethanolamine;
>, N-methyljetanol amino.

Aliphatic polyamines such as ethylene diamine, diethylene triamine, aromatic diamines such as I-lylene diamine, diphenylmethane diamine, etc.) Alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, etc. One or two types [Lanotam and/or block] Adducts, ring-opening polymers of alkylene oxides (ring-opening polymerization of tetrahydrofuran, hydrolyzed polytetra-1-ramethylene ether glycol); polyester polyols [polycarboxylic acids (aliphatic Polycarboxylic acids such as adipic acid, succinic acid.

Sepatic acid, azelaic acid, fumaric acid, maleic acid, trimerized lyluic acid, aromatic polycarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, etc.) and low molecular polyols or polyether polyols (the above low molecular polyols, terephthalic acids, etc.) polyester polyols whose terminal end is hydroxyl group, lactone polyester (such as polycaprolactone diol), polycarbonate diol, etc.;
Polybutadiene polyol, hydrogenated polybutadiene polyol, acrylic polyol; polymer polyol [polyol ("2, polyether.

Examples include polyols obtained by polymerizing vinyl monomers (acrylonitrile, styrene, etc.) in polyesters, etc. Among these, preferred are high-molecular polyols (especially polyether polyols and polyester polyols) and their combination with low-molecular polyols. Among the polyether polyols, preferred are polyoxypropylene polyol, poly(oxyethylene-oxybrobyleno) polyol [block addition (tipped, balanced, etc.) or/and lantam addition], polytetramethylene ether glycol, and polyether polyol. It is a mixture of Those having terminal hydroxyl groups (primary OH content of 30% or more, particularly 50 to 100%) are preferred. The preferred OH equivalents of the polymeric polyol are 200 to 25oo and <250 to 15oo.

When using a high molecular weight polyol and a low molecular weight polyol together,
The ratio can be varied depending on the required physical properties, but the ratio is usually 1:0 to 1:3, preferably 1:0.05.
~1:1.5. Average O of polyol (total)
H equivalent is usually 70 to 1000, preferably 100 to 500
It is. The average number of Yoino groups of Kada polyol is usually 2 to 3,
Preferably 2. O1 to 2.5. If necessary, other active hydrogen-containing compounds (polyamines, amino alcohols, etc.) may be used in combination with the polyol in small amounts (for example, up to 0.2 equivalents per 1 equivalent of the polyol).As the polyamines, preferably Aliphatic (aliphatic, cycloaliphatic or araliphatic) polyamines having a molecular weight of 60 to 300, such as ethylene diamine, tetramethylene diamine, hexamethylene diamine; 4.4'
-Diamino dicyclohexylmethane, 1,4-diaminocyclohexane, 4,4'-diamino-3,dimethylcyclohexylmethane, isophorone diamine, xylylene diamine, etc.; As amino alcohols, mono-
or di-ethanolamine.

Examples include propatool amines.

The proportion of polyisocyanate and polyol in the OH-terminated urethane polymer (a) from an aliphatic polyisocyanate and an excess of polyol can be varied; ) is usually 1:1.01~
1:13, preferably 1:1.08 to 1:1].

The polyisocyanun-1- and the polyol (and optionally other active hydrogen-containing compounds) may be reacted at once to produce a prepolymer (al), or a stepwise reaction method [part of the polyol (e.g. A method of producing prepolymer (a) by reacting a high molecular weight polyol) with polyisocyanate-1 to form an NGO-terminated prepolymer and then reacting the remainder of the polyol (for example, a low molecular weight polyol). Prepolymer (a) can be produced by reacting a part of the OH-terminated prepolymer and the remainder of the polyvinocyaninol-1, or by a combination of these methods. Good. The prepolymer formation reaction is usually performed at room temperature to 140'C.
Preferably it is carried out at 80-120°C. The reaction may be carried out in a solvent (eg dimethylformamide, dioxano, toluene, xylene, methylisobutylketoxy, cellosolfacet-i, etc.). The OH equivalent of the OH-terminated urethane prepolymer (a) is preferably 1,400 or more, more preferably 1.800 to 15,000, particularly 2,000 to 10,000. OH equivalent is 1.4
By using an OH-terminated urethane prepolymer larger than 0.00, the initial strength and demoldability of the surface layer can be significantly improved. The molecular weight of prepolymer (a) is usually 2.8
00-45,000, preferably 5,000-80,
It is 000. If it exceeds 45,000, the solution viscosity becomes too high and the solution concentration must be significantly lowered.

Aliphatic polyisocyanates 1-(b) constituting the skin-forming agent of the present invention include aliphatic, cycloaliphatic, and araliphatic polyisocyanates mentioned as raw materials for the prepolymer (a) and modified towara. Things can be used. In addition, an NCO-terminated prepolymer (NCO content, for example, 5 to 3,596 , preferably 10 to 25%) can also be used as (1). 3 pieces as at least part of (b), N above
Polyisocyanun-1・(tkoe id") having a co group
A polyisocyanate having a urea-hydrogen-bonded metal, which is obtained from 3 moles of aliphatic polyisonore (such as HDI) and 1 mole of water.

Trivalent or higher low-molecular polyol ([・excessive amount of rimethylol bromine (NC010H ratio at least 2/1)
It is preferable to use "NCO-terminated low molecular weight prepolymers with polyisono-1-1-" having an average of 25 to 3 NCO groups.
・It is. Such polyisocyanine-1. is particularly useful when a linear one is used as the OH-terminated prepolymer (a).

In the skin forming agent of the present invention, the ratio of (a) and (bl) can be varied, but the N co10H ratio is usually 1 to 5, preferably 1 to 3.
The overall average functional number of NCO groups in b) is 2.05 to 35
225-3 is particularly good.

(a, l-t or (a) and (b) are used in the form of 1 flll ordinary organic solvent solution. Examples of solvents include ketone solvents (ace-1-), methyl ethyl ketone, methyl isobutyl ), hydrocarbon solvents (+-lueno, xyleno, n-hexane, etc.), ester solvents (fn ethyl acetate, phtyl acetate, cellonorph acetate, etc.), ether solvents (tetrahydrofuran, etc.), Although the amount can be varied, the concentration of (a) is usually 2
An amount of 0 to 80%, preferably 30 to 60% is used. Solution viscosity is usually 500-30,000, preferably 2,000-10,000 CPS (25°C)
It is.

The skin forming agent of the present invention is a coloring agent according to 8 packages.

Catalyst, surfactant, antifoaming agent. It may contain additives such as fillers. Coloring agents include pigments and dyes such as carphone fluff; catalysts include amine catalysts such as triamine diamines;

N,N-methylcyclohexylamine, 1-limethylamine, triethylamine, N-ethylmorpholino, diasahiccyclounthecene (san-aho-i~(1)9DB
u), diethylethanolamine, etc.; organotin catalysts [for example, dibutyltin dilaurate, dibutyltin simalate, stannous octylate;

cyphthyl-tinoxy1~,his(1-lyn-phthyl)
tin oxy, etc.], other metal catalysts such as lead octylate, lead naphthenate, potassium octylate.

Examples of anti-aging agents include benzo, lyazole, benzoe+, hinted phenol, phosphite, piperine, etc., and as foam stabilizers. is a silicone foam stabilizer, such as a siloxane-oxane alkylenofloc copolymer;
As antifoaming agent and methylsiloxano 1 filler,
Examples include carunium carbonate, talc, barium sulfate, etc.

These additives may be added to either (a) or (b).

According to the present invention, a non-yellowing two-component urethane solution consisting of (al and (b)) is used as a skin forming agent for Moltco-1. The skin-forming agent of the present invention is applied (preferably by spray painting) to the inner surface of the mold for forming the foam.The skin-forming agent of the present invention can be coated in one or more coats.The amount of skin-forming agent applied to the inner surface of the mold is determined as required. Although the film thickness can be changed as appropriate depending on the physical properties, generally the film thickness is 0.01 or more, preferably 002 to 0.
It is 1 mm. The temperature of the mold can vary over a wide range, but is usually 30-80°C, preferably 40-60°C.
It is C.

As the mold-coating skinoform to which the skin-forming agent of the present invention is applied, conventional skinoforms can be used. As such a urethane foam raw material, commonly used materials consisting of polyol, polyisonne, blowing agent, catalyst, foam stabilizer, and other auxiliary agents can be used. Soft or semi-rigid foams are preferred. The urethane four 1 stock solution is introduced into the mold 1 after coating the inner surface of the mold 1 with the skin forming agent of the present invention. In the case of overcoating, it is preferable to pour the foam concentrate before the later applied coating has yet fully cured.

The skin forming agent for mold coating skin foam of the present invention is superior to conventional ones in the following points. In other words, the conventional non-yellowing powder-type linear polyurethane solution and the combination of a liquid-type linear polyurethane solution (surface layer forming agent) and a two-part type urethane stock solution (intermediate layer forming agent) do not form. Since the skin (surface layer) is a solvent-soluble linear polyurethane, it has poor solvent resistance and high solution viscosity (at low concentrations, the film is thin and requires several coats), and is non-yellowing - liquid tank. A linear polyurethane solution containing polyisocyanate (or a low molecular weight NCO-terminated prepolymer) and reacting with moisture in the air to cure (urea bond formation) has poor solvent resistance. Although it is somewhat improved, it is not completely satisfactory (especially with respect to alcohol, etc.), and polyisocyanates react with moisture to form a hard urea bond-containing polymer, resulting in a decrease in physical properties such as flexibility and elongation. On the other hand, the coating film formed from the skin-forming agent of the present invention has good solvent resistance and flexibility.

It also has excellent physical properties such as elongation. Also, conventional polyols (polyether polyol, polyester polyol, etc.)
In contrast to those using a two-component urethane stock solution (solution) consisting of and polyisocyanate (or NCO-terminated prepolymer), the initial strength is low and the surface layer is easily damaged (brittle) during demolding, and the demolding time is long. i OH-terminated urethane prepolymer (a,) and aliphatic polyisocyanate (b)
With the skin-forming agent of the present invention, which uses a two-component urethane solution consisting of the following, the skin formed reaches sufficient strength in a short period of time, and the demolding time is significantly shortened. Furthermore, in the case of using a reaction mixture (one-shot method or prepolymer method) consisting of aliphatic polyinocyanin-1-, polymer polyol (polyester polyol, polyether polyol, etc.) and aliphatic polyamine, Because of its extremely high reactivity, it reacts during or immediately after mixing to form a high molecular weight, resulting in poor sprayability and problems such as not being able to obtain a good spray coating and clogging the spray nozzle. The agent has appropriate reactivity, has good sprayability, and can perform uniform and good spray coating, resulting in a uniform film.

The skin foam formed from the skin-forming agent of the present invention is useful as seats, interior materials, and exterior materials for vehicles such as automobiles, motorcycles, snowmobiles, trains, and ships such as motorboats, as well as interior and exterior furniture and decorative materials. It is.

The present invention will be explained below with reference to Examples.
It is not limited to. In the following, parts are parts by weight,
Ratios indicate weight ratios. The prepolymers used in the Examples are as follows.

Prepolymers (a-1), (a-2) and (a-3
): The raw materials shown in Table 1 were charged in a four-bottle flask and reacted at 100'C for 6 hours under a nitrogen atmosphere. It has an OH value and an OH equivalent.

Table 1 - Note) Half 1; OH value 56. Half 2; OH value 45. +3;○H
Value 112° #4: Chinuhino 328 and Iruka Knox 10
Example 1 A non-yellowing two-component urethane solution having the following composition was used as the skin-forming agent of the present invention. .

Coronate HL' 5.5 parts note + adduct of trimethylolpropane and 3 moles of HD processing [manufactured by Nippon Polyurethane Industries] On the inner surface of a textured electroforming mold coated with a release agent and temperature-controlled at 50°C, The skin forming agent has a film thickness of 0.05t.
It was coated with a spray gun so that it would be xm and dried for 2 minutes. Next, while the coated surface is still not completely cured, the urethane foam stock solution with the following formulation is injected, the mold is closed and left at room temperature for about 5 minutes, and then removed from the mold, resulting in a good surface condition and feel. Get the skin form.

[Foaming prescription]

Millionate MR888 Polyoxypropylene oxyethylene tetraol (OH value 37) [manufactured by Sanyo Chemical Industries, Ltd.] lf2 Crude MDI (manufactured by Nippon Polyurethane Industries, Ltd.) Example 2 Non-yellowing two-component consisting of the following composition A molded urethane solution was used as the skin-forming agent in the present invention.

Prepolymer (a-2) 100 parts Carbon black 1.2 parts Methyl ethyl ketone 100 parts Sumidur N-75 US 1 3 parts Note) Rice 1 Additive of 1 mol of water and 8 mol of HDI [manufactured by Jujube Bayer Urethane Kogyo ■] Above skin Using a forming agent, a skin foam having good surface condition and feel was obtained in the same manner as in Example 1 (however, the film thickness was 0.06+u).

Example 3 A non-yellowing two-component urethane solution having the following composition was used as the skin-forming appetizer 1 of the present invention.

Coronet 1-HL 6 parts The above skin forming agent was used in the same manner as in Example 1 (however, the film thickness was 0.05 mm) to obtain a skin foam having a nice surface condition and feel.

Comparative Example 1 In the same manner as in Example 1, the following non-yellowing, corrugated linear polyurethane solution was applied with a spray gun to a film thickness of 0.05 mm, and dried for 3 minutes. Next, urethane foam stock solution 5 (used in Example 1) was injected onto the coating film, the mold was closed, and the mold was removed after about 5 minutes to obtain a skin foam with good surface condition and feel. However, this skin foam has poor solvent resistance and is used as a hair conditioner [product name MG-
When rubbing the epidermis with a cloth impregnated with 5 Shiseido ■, the carbon black falls off and transfers to the cloth, which also roughens the epidermis, posing a practical problem.

Non-yellowing - bath linear polyurethane solution *1100 parts by weight Carbon black 1 part by weight Anti-naming agent (same as in Example 1 used) 0.12 parts by weight Methyl ethyl ketone 200 parts by weight
Note) s-t: Synthesized polyurethane resin from polybutylene adipate diol, isophorone diisocyanate, and isophorone diamine, solid content 80%, toluene 30%.
%.

Methyl ethyl ketone 20%, isopropyl alcohol 2
0% and has a viscosity (25°C) of 80,000 cps.

Comparative Example 2 In the same manner as in Example 1, the following non-yellowing two-component urethane solution was applied to a film thickness of 005 and dried for 10 minutes. Next, the urethane foam stock solution (used in Example 1) was injected, the mold was closed, and when the mold was removed after about 5 minutes, the epidermis was not sufficiently hardened and a portion was left on the inner surface of the mold, causing the epidermis to disappear. It was damaged and its appearance was extremely bad.

Non-yellowing two-component urethane solution polyethylene butylene adipate (oH equivalent: 1,575
) 150 copies Korofuichi 1-HL
16 parts carbon black
32 parts Antioxidant (used in Example 1) 4.5 parts Methyl ethyl ketone
8o part Above Examples and Comparative Example 1
Table 2 shows the performance evaluation results of the skin foam obtained in .

Note) Rate: Under a load of 500g using a Gakushin type friction discoloration tester,
A white cotton cloth was impregnated with each solvent and reciprocated 100 times to see how much of the colorant was removed from the white cotton cloth.

◎: The film does not fall off. O: The film hardly falls off. No △: Slightly falling off ×: Significantly take off.

Ya 2: Black panel temperature 8 using fade meter
The surface condition was observed after irradiation for 400 or 800 hours at 3±3°C.

◎: No change in color O: Slight change in luster Yes ×: Significant change in gloss.

◎: No change in color, ○: Slight change in luster Yes: There is a change in the barge ×: Significant of There is a change in gloss.

Claims (1)

[Claims] 1. OH-terminated urethane prepolymer made from aliphatic polyisocyanate and excess polyol (consisting of a non-yellowing two-part urethane solution consisting of al and aliphatic polyisocyanate-1-(b)) Skin-forming agent for mold coated urethane foam. 2. The skin-forming agent according to claim 1, wherein (a) has an OH equivalent of at least 1,400. 8. Claim 1 or 2, which is a prepolymer obtained by reacting with a high molecular polyol and a low molecular polyol.
Skin-forming agent as described in Section 1. 4. The skin forming agent according to any one of claims 1 to 3, wherein at least a part of (b) has three or more NCO groups. 5. The ratio of (a) and (b) is NC0ZOH ratio 1 to 5
The skin forming agent according to any one of claims 1 to 4.