JPH0730200B2 - Expandable polyurethane resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a foamable polyurethane resin composition which forms a foam by heating.

[0002]

2. Description of the Related Art A foamable polyurethane resin composition comprising a urethane prepolymer having a blocked isocyanate group, a curing agent for a polyalkylene polyamine compound, a heat-decomposable foaming agent, and a solvent is known (for example, JP-A-60-). 147448).

[0003]

However, the conventional one has a problem that the storage stability of the expandable polyurethane resin composition is insufficient.

[0004]

Means for Solving the Problems As a result of intensive investigations by the present inventors to obtain a foamable polyurethane resin composition free from the above problems, the present invention has been accomplished by using a specific polyamine compound. That is, the present invention relates to a blocked polyisocyanate (A) in which an organic polyisocyanate (a) is blocked by a blocking agent, a polyamine compound (B) containing at least one amino group represented by the following structural formula, and heating. An expandable polyurethane resin composition comprising a decomposition-type foaming agent (C) and being foamed by heating. (In the formula, R ₁ and R ₂ are hydrocarbon groups having 1 or more carbon atoms, or R ₁ and R ₂ may be bonded to form a ring.)

Examples of the organic polyisocyanate (a) of the present invention include aliphatic, alicyclic, aromatic, araliphatic polyisocyanates and modified products thereof, and urethane prepolymers having a terminal isocyanate group. Hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI) and the like as aliphatic polyisocyanates; dicyclohexylmethane diisocyanate (HMD) as alicyclic polyisocyanates
I), isophorone diisocyanate (IPDI), 1,
4-cyclohexanediisocyanate (CHDI), hydrogenated xylylene diisocyanate (HXDI), hydrogenated tolylene diisocyanate (HTDI), etc .; as aromatic polyisocyanate, tolylene diisocyanate (TD)
I), 4,4 ′ (or 2,4 ′)-diphenylmethane diisocyanate (MDI), naphthalene diisocyanate (NDI), xylylene diisocyanate (XD)
I), tolidine diisocyanate (TODI), p-phenylene diisocyanate (PPDI); and α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI) as the araliphatic polyisocyanate.

As a modified product of an araliphatic, aliphatic, alicyclic or aromatic polyisocyanate compound, some or all of the isocyanate groups of the above-mentioned compounds are carbodiimide group, uretdione group, uretoimine group,
Examples thereof include compounds modified with a buret group or an isocyanurate group. You may use these 2 or more types together.
Preferred of these are burette-modified and isocyanurate-modified polyisocyanates derived from HDI, HMDI and IPDI.

Further, examples of the urethane prepolymer containing a terminal isocyanate group include urethane prepolymers derived from the above-mentioned organic polyisocyanate (a) and polyols. As the polyols used at this time, commonly used polyether polyols, polyester polyols, polymer polyols, polycarbonate polyols, polylactone polyols, polyolefin polyols and mixtures of two or more thereof are used, and a known urethane polymerization catalyst is used in the reaction. It can be added to accelerate the reaction.

Examples of the blocking agent used to obtain the blocked polyisocyanate (A) in the present invention include oxime compounds (acetoxime, methylethylketoxime, methylisobutylketoxime, etc.); lactams (ε-caprolactam, etc.) Alkylphenol compounds [monoalkylphenols (cresol, nonylphenol, etc.), dialkylphenols (3,5
-Xylenol, di-t-butylphenol, etc.), trialkylphenol (trimethylphenol, etc.)]; active methylene compound [malonic acid diester (diethyl malonate, etc.), acetylacetone, acetoacetate ester (ethyl acetoacetate, etc.)]; alcohol (Methanol, ethanol, n-butanol, etc.); Hydroxyl group-containing ether (methyl cellosolve, butyl cellosolve, etc.); Hydroxyl group-containing ester (ethyl lactate, amyl lactate, etc.); Mercaptans (butyl mercaptan, hexyl mercaptan, etc.); Acid amides (acetanilide , Acrylic amide, dimer acid amide, etc.); imidazoles (imidazole, 2-ethylimidazole, etc.); acid imides (succinimide, phthalimide, etc.), etc. Mixtures of two or more of al and the like. Of these, preferred are oxime compounds,
Lactams, particularly preferred are methyl ethyl ketoxime and ε-caprolactam. Among these, the blocking agent for obtaining a foam having excellent storage stability and having a sufficient dissociation temperature for regenerating an isocyanate group is generally in the range of 80 to 140 ° C.

The addition amount of the blocking agent is usually 1 to the isocyanate group of the organic polyisocyanate (a).
It is 2 equivalents, preferably 1.05 to 1.5 equivalents. The reaction temperature for blocking is usually 50 to 150 ° C. During the reaction, a known urethane polymerization catalyst can be added to accelerate the reaction.

As the polyamine compound (B) containing one or more amino groups having a specific structure used in the present invention, dicyclohexylmethanediamine (HMDA), isophoronediamine (IPDA), 1,4-cyclohexanediamine (CHDA). ), Hydrogenated xylylenediamine (H
XDA), hydrogenated tolylenediamine (HTDA), 3,
3'-Dimethyl-4,4'-diaminodicyclohexylmethane (MCHDA), 3,3'-dichloro-4,4 '
Alicyclic diamines such as diaminodicyclohexylmethane (MOCA) and isopropylidenedicyclohexyl-4,4'-diamine; diamines having an amino group directly connected to a 3-substituted carbon at the end [polyoxypropylenediamine (manufactured by Texaco Chemical Co., Jeffer Min D-230,
D-400, D-2000) and the like]; triamine having an amino group directly connected to a 3-substituted carbon at the terminal {ethyltris [aminopoly (isopropyloxymethyl)] methane (Texaco Chemical Co., Jeffamine T-403)
Etc .; and the like; and mixtures of two or more thereof. Of these, particularly preferred are HMDA and M
CHDA and IPDA.

Examples of the heat decomposition type foaming agent (C) used in the present invention include azobisformamide, azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile) and diazobenzene. , Azo compounds such as diazoaminobenzene and azodicarbonamide;
(Paratoluenesulfonylacetone hydrazone,
N, N'-dimethyl-N, N'-dinitroso-terephthalamide, N, N'-dinitrosopentamethylenetetramine, etc.) N-nitroso compounds; [benzene sulfonyl hydrazide, paratoluene sulfonyl hydrazide, 4,4 '-Oxybis (benzenesulfonylhydrazide), 4,4'-diphenylmethanesulfonylhydrazide, etc.] and the like; and mixtures of two or more thereof. Of these, preferred are 4,4'-oxybis (benzenesulfonyl hydrazide) and azodicarbonamide. The amount of the heat-decomposable foaming agent (C) used is usually 0.5 to 10 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of the blocked polyisocyanate (A).

If necessary, the foaming polyurethane resin composition of the present invention may be used in combination with a blocking agent dissociation catalyst (D) to shorten the heat treatment time. Examples of the blocking agent dissociation catalyst (D) used in the present invention include organotin compounds [dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dimaleate, dibutyldibutoxytin, bis (2-ethylhexyl) tin oxide, 1,1. , 3,3-Tetrabutyl-1,3-diacetoxydistannoxane, etc.]; Potassium and sodium metal salts of organic acids such as alkylsulfuric acid and alkylphosphonic acid,
Sodium, potassium, nickel, cobalt, cadmium, barium, calcium of fatty acids having 8 to 20 carbon atoms,
Salts such as zinc; and mixtures of two or more thereof. Among these, preferred are dibutyltin dilaurate and dioctyltin dimaleate. The amount of the blocking agent dissociation catalyst (D) used is usually 0.0 with respect to 100 parts by weight of the blocked polyisocyanate (A).
The amount is 05 to 10 parts by weight, preferably 0.01 to 5 parts by weight.

Further, a plasticizer (E) may be used in combination for the purpose of improving the processability, texture and low temperature characteristics of the polyurethane foam film and sheet. In this case, the blocked polyisocyanate (A) or the blocked urethane prepolymer is usually used by diluting it with the plasticizer (E) or used before blocking. Examples of the plasticizer (E) for this purpose include phthalic acid ester type plasticizers (diethyl phthalate, dibutyl phthalate, dioctyl phthalate, dilauryl phthalate, distearyl phthalate, diisononyl phthalate, etc.); fatty acid ester type plasticizers (dioctyl adipate, dioctyl). Sebacate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, etc.); Phosphate ester type plasticizer (tricresyl phosphate, cresyl diphenyl phosphate, triallyl phosphate, isodecyl diphenyl phosphate, etc.) And the like; and mixtures of two or more thereof. Particularly preferred among these are distearyl phthalate, diisononyl phthalate and isodecyl diphenyl phosphate.

The amount of the plasticizer (E) used is preferably 100 parts or less with respect to 100 parts of the blocked polyisocyanate (A).

In addition, an auxiliary material may be added to the expandable polyurethane resin composition of the present invention, if necessary.
For example, coloring agents such as inorganic pigments, organic pigments, organic fluorescent pigments or pearl foil, gold powder, silver powder for decorative coloring; calcium carbonate, silicic acid anhydride, talc, titanium oxide for the purpose of changing the feel and improving economic efficiency. Inorganic fillers such as; texture,
For the purpose of improving physical properties and economy, vinyl chloride resin, ABS resin, ethylene-vinyl acetate copolymer resin and the like can be used. Further, an ultraviolet absorber, an antioxidant, an antistatic agent, a flame retardant, a thickener, a leveling agent, a foam stabilizer and the like can be added depending on the purpose.

The blocked polyisocyanate (A) of the present invention, the polyamine compound (B) containing at least one amino group represented by the above structural formula, the thermal decomposition type foaming agent (C), the blocking agent dissociation catalyst (D). ) And the plasticizer (E) are not particularly limited, but preferably the blocked polyisocyanate (A) and the polyamine compound (B) containing at least one amino group represented by the above structural formula are blended. The heat-decomposable foaming agent (C), the blocking agent dissociation catalyst (D) and the plasticizer (E) are added to the product, and then mechanical forced dispersion is performed using a disperser or the like. The compounding and mechanical forced dispersion steps are usually performed at 50 ° C. or lower. It is necessary to degas before performing the heat foaming treatment. The expandable polyurethane resin composition of the present invention is usually 50 ° C. or lower,
It is preferably stored at 40 ° C or lower.

The viscosity of the expandable polyurethane resin composition before heat-foaming treatment is less than 10 poise or 100 at 25 ° C.
If it exceeds 0 poise, a sufficient foam cannot be obtained.

The method of forming the foamable polyurethane resin composition of the present invention into a foamed film or sheet includes dipping,
Using a coating machine such as a roll coater, knife coater, or air doctor coater, the composition is cast on a substrate that is a part of the composite substrate, or on a silicone release paper or a steel silicone belt, and then blocked polyisocyanate. By passing through a heating furnace heated to a dissociation temperature of (A) and a decomposition temperature of the heat decomposition type foaming agent (C), the heat decomposition type foaming agent (C) is generated in parallel with the curing of the polyurethane resin. A foamed film or sheet having a crosslinked structure can be obtained by the decomposition gas.

The foamed film or sheet obtained from the foamable polyurethane resin composition of the present invention utilizes heat resistance, water resistance, solvent resistance, and cushioning properties to make clothes, automobiles,
It is useful as a material for home appliances, furniture (carpets, etc.), leather substitutes, double-sided tapes and footwear.

[0020]

EXAMPLES The present invention will be further described below with reference to test examples, but the present invention is not limited thereto. Parts in the test examples are parts by weight.

Production Example 1 (1) 322 parts of isocyanurate-modified polyisocyanate modified from hexamethylene diisocyanate (TPA-10 manufactured by Asahi Kasei Co., Ltd.) was placed in a glass flask having an internal volume of 1 L.
0, NCO content 23.4%), and 215 parts of diisononyl phthalate were charged. While passing nitrogen gas under stirring, 163 parts of methyl ethyl ketoxime were charged while cooling, and a blocking reaction was performed at 60 ° C. for 1 hour.
A blocked polyisocyanate having an O content of 0.001% was obtained. (2) 100 parts of this blocked polyisocyanate was thoroughly mixed and dispersed with 21.6 parts of isophorone diamine and 3 parts of 4,4'-oxybis (benzenesulfonyl hydrazide) (Selmike S, manufactured by Sankyo Kasei Co., Ltd.). After that, defoaming was performed under reduced pressure. The viscosity of this formulation at 25 ° C. was 370 poise. The storage stability of this product is 40
The viscosity increase rate after storage at 10 ° C for 10 days was 1.1 times. (3) The mixed solution stored at 40 ° C. for 10 days was put on a release paper in an amount of 0.1.
After coating on 5 mm, it was heated in an oven at 140 ° C. for 20 minutes to obtain a flexible urethane foam sheet with a foaming ratio of about 3 times.

Production Example 2 (1) 3,3'-Dimethyl-4, based on 100 parts of the blocked polyisocyanate obtained in Production Example 1 (1)
After thoroughly mixing and dispersing 30.3 parts of 4'-diaminodicyclohexylmethane and 3 parts of azodicarbonamide (Celmic C, manufactured by Sankyo Kasei Co., Ltd.), defoaming was performed under reduced pressure. The viscosity of this formulation at 25 ° C was 340 poise. Regarding the storage stability of this product, the rate of increase in viscosity after storage at 40 ° C. for 10 days was 1.2 times. (2) The mixed solution stored at 40 ° C. for 10 days was placed on a release paper in an amount of 0.
After coating on 5 mm, it was heated in an oven at 140 ° C. for 20 minutes to obtain a flexible urethane foam sheet with a foaming ratio of about 3 times.

Production Example 3 (1) 533 parts of polyether polyol (Sanyo Chemical Co., Ltd., Sannix Diol PP-2000, molecular weight 2,000), 118 parts of isophorone diisocyanate, and 0 parts of dibutyltin dilaurate were placed in a glass flask having an internal volume of 1 L. .05 copies were loaded. While passing nitrogen gas under stirring, the mixture was gradually heated to 90 ° C. and then reacted at 90 ° C. for 5 hours to obtain a urethane prepolymer having an NCO content of 3.4%. Further, under cooling, 49 parts of methyl ethyl ketoxime was dividedly charged and the blocking reaction was carried out at 50 ° C. for 1 hour.
A blocked urethane prepolymer having an NCO content of 0.001% was obtained. (2) 100 parts of this blocked polyisocyanate was thoroughly mixed and dispersed with 6.4 parts of isophorone diamine and 3 parts of 4,4'-oxybis (benzenesulfonylhydrazide) (Selmike S, manufactured by Sankyo Kasei Co., Ltd.). After that, defoaming was performed under reduced pressure. The viscosity of this formulation at 25 ° C is 1
It was 30 poise. Storage stability of this product is 40 ℃
The viscosity increase rate after storage for 10 days was 1.1 times. (3) The mixed solution stored at 40 ° C. for 10 days was put on a release paper in an amount of 0.1.
After applying 5 mm, it was heated in an oven at 140 ° C. for 20 minutes to obtain a flexible urethane foam sheet with a foaming ratio of about 3.5 times.

Production Example 4 (1) 3,3'-Dimethyl-4, based on 100 parts of the blocked urethane prepolymer obtained in Production Example 3 (1).
9.0 parts of 4'-diaminodicyclohexylmethane, 3 parts of azodicarbonamide (Cermic C, Sankyo Kasei Co., Ltd.)
After thoroughly mixing and dispersing and, defoaming was performed under reduced pressure. The viscosity of this formulation at 25 ° C. was 110 poise. Regarding the storage stability of this product, the rate of increase in viscosity after storage at 40 ° C. for 10 days was 1.2 times. (2) The mixed solution stored at 40 ° C. for 10 days was placed on a release paper in an amount of 0.
After coating on 5 mm, it was heated in an oven at 140 ° C. for 20 minutes to obtain a flexible urethane foam sheet with a foaming ratio of about 4 times.

Production Example 5 (1) To 100 parts of the blocked polyisocyanate obtained in Production Example 1 (1), 39 parts of ethyl tris (aminopropyloxymethyl) methane (Texaco Chemical Co., Jeffamine T-403) was added. , 3 parts of azodicarbonamide (Selmike C, manufactured by Sankyo Kasei Co., Ltd.) were thoroughly mixed and dispersed, and then defoaming was performed under reduced pressure. 25 ° C of this formulation
The viscosity was 320 poise. Regarding the storage stability of this product, the rate of increase in viscosity after storage at 40 ° C. for 10 days was 1.3 times. (2) The mixed solution stored at 40 ° C. for 10 days was placed on a release paper in an amount of 0.
After coating on 5 mm, it was heated in an oven at 140 ° C. for 20 minutes to obtain a flexible urethane foam sheet with a foaming ratio of about 3 times.

Comparative Production Example 1 (1) A glass flask having an internal volume of 1 L was charged with 449 parts of polyethylene adipate (molecular weight 2000), 78 parts of tolylene diisocyanate, 132 parts of xylene and 0.05 part of dibutyltin dilaurate. Gradually heat to 80 ° C while passing nitrogen gas under stirring, then 80 ° C
Was reacted for 5 hours to obtain a urethane prepolymer having a solid content of 80% and an NCO content of 2.8%. Then, the mixture was cooled to 50 ° C., 40 parts of methyl ethyl ketoxime was dividedly charged, and a blocking reaction was carried out at 50 ° C. for 1 hour to obtain a blocked urethane prepolymer having an NCO content of 0.001%. (2) To 100 parts of this blocked urethane prepolymer, 1.3 parts of diethylenetriamine and 3 parts of 4,4′-oxybis (benzenesulfonylhydrazide) (manufactured by Sankyo Kasei Co., Celmic S) were sufficiently mixed and dispersed. After that, defoaming was performed under reduced pressure. The storage stability of this product is 4
After 5 days of storage at 0 ° C., it was completely solidified, and the viscosity could not be measured.

Comparative Production Example 2 (1) 423 parts of polytetramethylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd .: PTM) was placed in the same apparatus as in Comparative Production Example 1 (1).
G-2000, molecular weight 2000), 106 parts of 4,4'-diphenylmethane diisocyanate, 132 parts of dimethylformamide and 0.05 part of dibutyltin dilaurate were charged. While passing nitrogen gas under stirring, gradually heat to 80 ° C., and then react at 80 ° C. for 5 hours to obtain N 2
A urethane prepolymer having a CO content of 2.5% was obtained. Then, cool to 50 ° C. and methylethylketoxime 39
Parts were divided and charged, and a blocking reaction was carried out at 50 ° C. for 1 hour to obtain a blocked urethane prepolymer having an NCO content of 0.001%. (2) With respect to 100 parts of this blocked urethane prepolymer, 1.5 parts of iminobispropylamine (manufactured by BASF, Laromin A-327), 2 parts of 4,4′-oxybis (benzenesulfonyl hydrazide) (Sankyo After thoroughly mixing and dispersing 1 part of azodicarbonamide (Cermic company, Celmic S), and azodicarbonamide (Sankyo Kasei Corp., Celmic C), defoaming was performed under reduced pressure. The storage stability of this product is 40
After 5 days of storage at ℃, it was completely solidified, and the viscosity could not be measured.

Table 1 shows the evaluation results of the storage stability of the production examples and the comparative production examples.

[0029]

[Table 1] Storage stability: Viscosity increase rate after storage at 40 ° C for 5 and 10 days (viscosity after storage / initial viscosity, using B-type viscometer)

[0030]

The present invention has the following effects. (1) Since the composition of the present invention is excellent in storage stability, the composition can be stored in a storage tank during production, and the production and removal of lines occurring at the start and end of the work are eliminated. The efficiency is greatly improved. (2) Conventionally, since the composition used for this purpose contains a solvent, the problem of ignition due to the organic solvent scattered during heating and the problem of recovering the organic solvent for preventing odor generation are improved. (3) A foamed film or sheet obtained from the foamable urethane resin composition of the present invention utilizes heat resistance, water resistance, solvent resistance, and cushioning properties to make clothes, automobiles, home appliances, furniture (carpets, etc.), leather. It is useful as a material for substitutes, double-sided tapes and footwear.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area C08L 75:04

Claims (6)

[Claims] 1. A blocked polyisocyanate (A) in which an organic polyisocyanate (a) is blocked by a blocking agent, a polyamine compound (B) containing at least one amino group represented by the following structural formula, and heating. A foamable polyurethane resin composition comprising a decomposition type foaming agent (C) and being foamed by heating. (In the formula, R ₁ and R ₂ may be a hydrocarbon group having 1 to 4 carbon atoms, or R ₁ and R ₂ may combine to form a ring.) 2. The expandable polyurethane resin composition according to claim 1, wherein the polyamine compound (B) is selected from the group consisting of alicyclic diamines and polyoxypropylene polyamines. 3. The blocked polyisocyanate (A)
The foamable polyurethane resin composition according to claim 1 or 2, wherein the blocking agent is an oxime compound or a lactam. 4. The expandable polyurethane resin composition according to claim 1, further comprising a blocking agent dissociation catalyst (D). 5. A plasticizer (E) is further included.
The expandable polyurethane resin composition according to any one of to 4. 6. A blocked polyisocyanate (A),
The polyamine compound (B), a thermal decomposition type foaming agent (C),
The expandable polyurethane resin composition according to any one of claims 1 to 5, wherein the blocking agent dissociation catalyst (D) and the plasticizer (E) composition have a viscosity of 10 to 1000 poise at 25 ° C.