JPH0559144A - Production of flexible polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain the objective foam excellent in foam physical properties by using only water as a foaming agent by blending a polyhydroxy compound and an organic polyisocyanate, etc., with a specific amount of an additive composed of castor oils, etc. CONSTITUTION:(A) A polyhydroxy compound, (B) an organic polyisocyanate, (C) a catalyst, (D) a foam stabilizer and (E) water as a foaming agent are blended with (F) one or more compounds selected from the group consisting of (i) castor oils (derivatives), (ii) RCOO-[CH2-CH(CH3)-O]k-COR (k is 1-60; R and R<1> are 1-30C hydrocarbon), (iii) H2C=C(CH3)-COO-(CH2-CH2-O)m-CH3 (m is 1-25), (rv) R<2>-COO-R<3> (R<2> is 5-25C hydrocarbon; R<3> is 1-15C hydrocarbon) and (v) R<4>-COO-(CH3)n-OCOR<5>(n is 1-10; R<4> and R<5> are 5-25C hydrocarbon) as an additive in an amount of 0.1-15wt.% based on the component (A) to afford the objective foam.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing flexible polyurethane foam using substantially only water as a blowing agent.

[0002]

2. Description of the Related Art Conventionally, trichlorofluoromethane (commonly known as R-11) or dichlorodifluoromethane (commonly known as R-12) is foamed in the production of flexible or rigid polyurethane foam used for heat insulating materials, automobile seats, furniture, cushions and the like. It has been used as an agent.

However, due to the recent ozone problem, R
There is an urgent need to reduce the amounts of -11 and R-12 used, and as a substitute for them, a method of foaming with carbon dioxide generated in the reaction between water and isocyanate is being studied.

However, in this production method, there are problems in the moldability and foam physical properties of the urethane foam obtained, and in particular, there are many problems in the production of low density foam which uses a large amount of foaming agent.

[0005]

Particularly, in the molding of a flexible urethane foam, the surface skin portion of the molded urethane foam is poor in the curing property, and when the urethane foam is released from the mold, peeling and tearing of the urethane foam are likely to occur. , The peeled skin adheres to the mold and makes it difficult to clean the mold, and the appearance is very bad. Further, the obtained urethane foam has drawbacks in physical properties such as increase in hardness and deterioration in compression set.

In order to solve these problems, there is a method of using a specific additive, but it is not a complete method. For example, the addition of propylene carbonate reduces the hardness of urethane foam.

It is an object of the present invention to provide a method for producing a flexible urethane foam which is excellent in foam physical properties, moldability and surface curability and has a low hardness, by eliminating the above-mentioned drawbacks in the conventional method for producing a foam by water foaming. To do.

[0008]

Means for Solving the Problems In the present invention, when a flexible polyurethane foam is produced from a polyhydroxy compound, an organic polyisocyanate, a catalyst, a foam stabilizer, water as a foaming agent and an additive, the following ( A) ~
At least one additive selected from (E) is used in an amount of 0.1 to 15% by weight based on the polyhydroxy compound.

(A) Castor oil and / or its derivative (B) RCOO- [CH ₂ -CH (CH ₃ ) -O] _k -COR ¹ k = ^{1 to} 60, R, R ¹ = C _{1 to} C ₃₀ hydrocarbon group _{(C) H 2 C = C} (CH 3) -COO- (CH 2 -CH 2 -O) m -CH 3 m = 1~25 (D) R 2 -COO-R 3 R 2 = C _{5 to} C ₂₅ hydrocarbon group R ³ = C _{1 to} C ₁₅ hydrocarbon group (E) R ⁴ COO- (CH ₂ ) _n -OCOR ⁵ n = 1 to 10, R ⁴ , R ⁵ = C ₅ -C ₂₅ hydrocarbon radical

The polyhydroxy compound used in the present invention is mainly composed of at least one polyoxyalkylene polyol having an average hydroxyl value of about 10 to 90 and / or a polyoxyalkylene polyol containing polymer fine particles. Polyols are preferred.

Polyoxyalkylene polyol and /
Alternatively, the polymer fine particle-containing polyoxyalkylene-based polyol may be a mixture of two or more kinds, and a small amount (not more than about 20% by weight based on the total polyol) of a non-polyoxyalkylene-based polyol such as polyester-based polyol or It may contain a polydiene-based (especially butadiene homopolymer or copolymer) polyol having two or more hydroxyl groups.

The polyhydroxy compound preferably consists essentially of a polyoxyalkylene-based polyol or a polyoxyalkylene-based polyol containing polymer fine particles. However, a polyol having a low molecular weight (usually about 600 or less) called a cross-linking agent or a chain extender is not included in the polyol here.

The method for producing a flexible foam is roughly classified into a hot cure foam and a cold cure foam depending on the curing method, but the present invention can be applied to any foam.

The average hydroxyl value of the polyol for hot cure foam in the present invention is usually in the range of about 40 to 90, particularly about 50 to 80. Therefore, it is preferable that the average hydroxyl value of the polyol is within this commonly used range. Suitably the average number of hydroxyl groups in the polyol is about 2-8, especially about 2-4, most preferably about 2.5-.
It is preferably 3.5.

The average hydroxyl value of the polyol for cold cure foam in the present invention is usually about 10 to 7.
0, especially in the range of about 15-65. Therefore, it is preferable that the average hydroxyl value of the polyol is within this commonly used range. Suitably the average number of hydroxyl groups in the polyol is about 2-8, especially about 2-4, most preferably about 2.5-4.5.

The polyoxyalkylene-based polyol may be a so-called primary polyoxyalkylene-based polyol containing a primary hydroxyl group obtained by capping ethylene oxide at the terminal as described below, and the polyoxyalkylene-based polyol may have an internal oxyalkylene chain. It may be a polyoxyalkylene-based polyol in which ethylene oxide is capped or uncapped at an end containing an oxyethylene group. In this case, the oxyethylene group content in the polyoxyalkylene-based polyol is preferably 30% by weight or less on the average, including the ends and the inside of the oxyalkylene chain.

The polyoxyalkylene-based polyol is a polyether polyol obtained by adding an alkylene oxide to a compound (hereinafter referred to as an initiator) having a hydrogen atom to which at least two alkylene oxides can be added.

A small amount of other monoepoxides such as halogen-containing alkylene oxides, styrene oxides, glycidyl ethers, etc. may be added with the alkylene oxide, but preferably substantially only the alkylene oxide is used.

The alkylene oxide has 2 to 4 carbon atoms.
The alkylene oxide of is suitable, and propylene oxide alone or a combination of propylene oxide and ethylene oxide is particularly preferable. When propylene oxide and ethylene oxide are used in combination, a mixture of both may be added, they may be added separately in sequence, or they may be combined. The hydroxyl value of the polyoxyalkylene polyol is adjusted by the amount of the alkylene oxide added.

When ethylene oxide is added last, it is a cap of ethylene oxide. It is also possible to further add a small amount of propylene oxide after the ethylene oxide cap to adjust the proportion of primary hydroxyl groups.

As the initiator, polyhydric alcohols, polyhydric phenols, mono- or polyamines, and others can be used, but polyhydric alcohols and polyhydric phenols are suitable, and polyhydric alcohols are particularly preferable. Also, two or more initiators can be used in combination. Specific examples of the initiator are shown below, but the initiator is not limited to these. A particularly preferred initiator is a trihydric polyhydric alcohol, or a mixture thereof with a dihydric or tetrahydric or higher polyhydric alcohol-based initiator.

Divalent initiator: ethylene glycol,
Diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, bisphenol A. Trivalent initiator: glycerin, trimethylolpropane, hexanetriol. Initiator having a valence of 4 or more: pentaerythritol, diglycerin, ditrimethylolpropane, dextrose, sorbitol,
Sucrose, novolak.

The polymer fine particle-containing polyoxyalkylene-based polyol containing the polymer fine particles is prepared by polymerizing an ethylenically unsaturated monomer in the polyol, mixing separately prepared polymer fine particles with the polyol, or ethylenically unsaturated. It is produced by a method of polymerizing a macromonomer having a group and an ethylenically unsaturated monomer in a polyol. This polymer fine particle-containing polyoxyalkylene-based polyol is also called a polymer polyol.

Examples of the ethylenically unsaturated monomer include styrene and acrylonitrile. For example, a polymer polyol obtained by graft-polymerizing these monomers in a polyol in the presence of a free radical polymerization catalyst can be used as a part or the whole amount of the polyhydroxy compound. The amount of the polymer fine particles is preferably 50% by weight or less, particularly preferably 30% by weight or less, based on the total polyoxyalkylene polyol.

The other main raw material for the production of flexible polyurethane foam is a polyisocyanate compound. As the polyisocyanate compound, various compounds having two or more isocyanate groups can be used, but aromatic polyisocyanates are particularly suitable. As the aromatic polyisocyanate, a mononuclear or polynuclear compound having an isocyanate group bonded to an aromatic nucleus or a modified product thereof is suitable.

Specific examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, and their prepolymer type, carbodiimide type, urea type and other modified products.

Two or more of these polyisocyanate compounds can be used in combination. The polyisocyanate compound is used in an amount of about 85 to 120, particularly about 90 to 110, which is represented by 100 times the number of isocyanate groups with respect to the number of active hydrogens in all active hydrogen-containing compounds (usually called isocyanate index).

The polyhydroxy compound is mainly a polyol such as the above polyoxyalkylene-based polyol, but it also contains a small amount of water as a foaming agent, and depending on the case, a small amount of the chain extender or the crosslinking agent is used. be able to. These are usually compounds having a molecular weight of about 600 or less and having two or more active hydrogens, particularly polyhydric alcohols having a molecular weight of 400 or less, low molecular weight polyether polyols, alkanolamines, polyamines and the like.

Another one of the essential components of the foamable mixture is a catalyst. As a catalyst for producing a flexible polyurethane foam, a tertiary amine-based catalyst and an organic metal compound, especially an organic tin compound are usually used, and they are usually used in combination. Various tertiary amine-based catalysts can be used as the tertiary amine-based catalyst.

For example, triethylenediamine, N-ethylmorpholine, N, N-dimethylaminoethylmorpholine, triethylamine, N, N, N ', N'-tetramethylhexamethylenediamine, bis (2-dimethylaminoethyl) ether, N, N ', N'-trimethylaminoethylethanolamine, and the like.

Two or more of these may be used in combination.
A particularly preferred tertiary amine catalyst is triethylenediamine, and a mixture of triethylenediamine and dipropylene glycol in a weight ratio of 1: 2, which is well known under the trade name of "Dabco-33LV", is most suitable.

The amount used can be changed depending on the intended reaction conditions and the like, but is usually about 0.01 to 2.0 parts by weight, preferably 0.02, based on 100 parts by weight of the polyol.
.About.1.5 parts by weight is suitable, especially "Dabco-33".
It is suitable to use 0.1 to 1.0 parts by weight as "LV".

The organometallic compound catalyst is most preferably an organotin compound catalyst, for example, stannas octoate, stannas laurate, dibutyltin dilaurate,
Examples include dibutyltin dimaleate, dibutyltin diacetate and dioctyltin diacetate. In particular, stanna octoate, dibutyltin dilaurate and the like are preferable.

The amount of the organotin compound catalyst used is usually 0.01 to 1.0 part by weight based on 100 parts by weight of the polyol. However, the amount of this catalyst used needs to be delicately changed depending on the type and reactivity of the polyol and other conditions, and various optimum ranges are relatively narrow.

The additives used in the present invention are (A) to
It is at least one selected from (E). (A) Castor oils and / or derivatives thereof (B) RCOO- [CH ₂ -CH (CH ₃ ) -O] _k -COR ¹ k = ^{1 to} 60, R, R ¹ = C _{1 to} C ₃₀ carbonization hydrogen group _{(C) H 2 C = C} (CH 3) -COO- (CH 2 -CH 2 -O) m -CH 3 m = 1~25 (D) R 2 -COO-R 3 R 2 = C 5 To C ₂₅ hydrocarbon group R ³ = C _{1 to} C ₁₅ hydrocarbon group (E) R ⁴ COO- (CH ₂ ) _n -OCOR ⁵ n = 1 to 10, R ⁴ , R ⁵ = C _{5 to} C ₂₅ hydrocarbon radicals

The compounds (A) to (E) will be described. (A) Castor oil and / or its derivative The castor oil and / or its derivative (A) may be any of refined castor oil, semi-refined castor oil and unrefined castor oil, and hydrogenation with hydrogen addition. It may be a derivative of castor oil such as castor oil. Specifically, UR made by Ito Oil
IC • H-30, etc., but not limited to this.

(B) RCOO- [CH ₂ -CH (CH ₃ ) -O] _k -COR ¹ k = ^{1 to} 60, R, R ¹ = C _{1 to} C ₃₀ The hydrocarbon group k is especially 5 to 5. 50 is preferred, and most preferably 10-40. R and R ¹ are alkyl groups or alkenyl groups having 1 to 30 carbon atoms, and may be the same or different. Specifically, Unisafe NKL-9520 (manufactured by NOF CORPORATION) manufactured by NOF CORPORATION is preferred, but the invention is not limited thereto.

(C) H ₂ C = C (CH ₃ ) -COO- (CH ₂ -CH ₂ -O) _m -CH ₃ m = 1 to 25 m is particularly preferably 1 to 20, most preferably 1 It is -10. Specific examples thereof include Bremmer PME-400 manufactured by NOF CORPORATION, but are not limited thereto.

(D) R ² -COO-R ³ R ² = C _{5 to} C ₂₅ hydrocarbon group R ³ = C _{1 to} C ₁₅ hydrocarbon group R ² is a carboxylic acid having 5 to 25 carbon atoms. It is a residue, particularly a residue of a carboxylic acid such as oleic acid, stearic acid, palmitic acid, lauric acid and erucic acid. R ³ is an alkyl group, particularly a methyl, ethyl, butyl, octyl group or the like. Specifically, Unistar MB- made by NOF Corporation
However, the present invention is not limited to this.

(E) R ⁴ COO- (CH ₂ ) _n -OCOR ⁵ n = 1-10, R ⁴ , R ⁵ = C ₅ -C ₂₅ hydrocarbon groups R ⁴ , R ⁵ have 5 to 5 carbon atoms. 25 are carboxylic acid residues, particularly carboxylic acid residues such as oleic acid, stearic acid, palmitic acid, lauric acid and erucic acid. R ⁴
And R ⁵ may be the same or different. 3-6 are especially preferable for n.

The amount of the above additives used is 0.1 to 15% by weight based on the polyhydroxy compound. It is preferably 0.5 to 10% by weight, especially 3 based on the polyhydroxy compound.
-12 wt% is preferred.

Another component added to the foamable mixture is a foaming agent. As the foaming agent, only water is particularly preferable, but a halogenated hydrocarbon-based foaming agent, a low boiling point gas such as air, or another foaming agent may be used together in a small amount.

Examples of the halogenated hydrocarbon blowing agent include trichlorofluoromethane, dichlorodifluoromethane, methylene chloride, monochlorodifluoromethane, 1,1-dichloro-2,2,2-trifluoroethane, 1,1- Examples include dichloro-1-fluoroethane.

The amount of the foaming agent used may vary depending on the density of the desired foam, but is usually about 1 to 10 parts by weight, particularly about 2 to 8 parts by weight, based on 100 parts by weight of the polyol.

Still another normally essential component is a siloxane-based foam stabilizer such as polydialkylsiloxane and polydialkylsiloxane-polyoxyalkylene block copolymer.

Other optional components include, for example, colorants, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, and other additives that can be used in the production of cure foam.

The flexible polyurethane foam with high skin strength obtained by the present invention is particularly suitable as a cushion sheet material for automobiles. However, the material is not limited to the seat material for automobiles, and can be applied as a cushion seat material for other uses, or to the field where the flexible polyurethane foam is conventionally used.

[0048]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. Parts indicate parts by weight.

(Polyol) Polyol A: Hydroxyl value of 70.1 mg KOH / which is obtained by addition polymerization reaction of propylene oxide with glycerin.
g of polyoxypropylene polyol Polyol B; hydroxyl value obtained by subjecting glycerin to propylene oxide addition polymerization reaction 34.0 mg KOH /
g of polyoxypropylene polyol Polyol C; polymer polyol having a hydroxyl value of 28.0 mgKOH / g obtained by subjecting glycerin to addition polymerization reaction of propylene oxide and further graft polymerization of acrylonitrile.

Additive A; URIC H-30 (manufactured by Ito Oil Co., Ltd.) Additive B; CH ₃ COO- [CH ₂ -CH (CH ₃ ) -O] _k -COCH ₃ molecular weight 1070 Additive C; Bremmer PME- 400 (manufactured by NOF Corporation) Additive D; Unistar MB-816 (manufactured by NOF CORPORATION) Additive E; Propylene carbonate (Atlantic
Made by Richfield)

(Example 1) 95 parts of polyol A, 5 parts of additive A, 5.5 parts of water, amine catalyst [Dabco-
33LV (manufactured by Sankyo Air Products) 0.36 parts, Dab
a mixture of 0.05 parts of co-XDM (manufactured by Sankyo Air Products) and 0.05 parts of NC-IM (manufactured by Sankyo Air Products)], a foam stabilizer S-736-08 (manufactured by Nippon Unicar)
TDI-80 (2,4-TDI / 2,6-TDI = 8) in a mixture of 1.5 parts and 0.12 parts of stanna octoate.
0/20 mixture) was mixed under the conditions of a liquid temperature of 25 ° C. and an isocyanate index of 95.

Next, 350 mm × 350 mm × 100 mm
Foaming was performed at a mold temperature of 40 ° C. using the aluminum mold. After curing in a 170 ° C. oven for 10 minutes, the temperature was kept at 150 ° C. and the mold was removed. The physical properties of the soft hot mold foam after demolding were evaluated, and the results are shown in Table 1.

Examples 2 to 4 and Comparative Example 1 Example 1 was repeated except that the additive shown in Table 1 was used in place of the additive A, and the polyol A and the additive were used in the proportions shown in Table 1. A flexible hot mold foam was produced in the same manner as in.
The evaluation results are shown in Table 1.

Comparative Example 2 A soft hot mold foam was produced in the same manner as in Example 1 except that no additive was used. The evaluation results are shown in Table 1.

Example 5 66.5 parts of polyol B,
28.5 parts of polyol C, 5 parts of additive A, 3.0 parts of water
Parts, amine catalyst [Dabco-33LV 0.65 parts and Niax-A-1 (manufactured by Union Carbide) 0.0.
5 parts of mixture], foam stabilizer SF-2962 (Toray Dow
TM-20 [TDI-8] in a mixture of 1.00 parts of Corning Silicone) and 2.0 parts of triethanolamine.
0 / crude MDI = 80/20] was mixed under the conditions of a liquid temperature of 25 ° C. and an isocyanate index of 105, and foaming was performed at a mold temperature of 60 ° C. using the same mold as in Example 1.

Next, curing was carried out in an oven at 80 ° C. for 6 minutes to produce a soft cold cure foam. Their physical properties were measured, and the results are shown in Table 1.

(Examples 6 to 9 and Comparative Example 3) Soft cold cure foams were produced in the same manner as in Example 5 except that the additives shown in Table 2 were used and the raw materials were used in the proportions shown in Table 2. did. The evaluation results are shown in Table 2.

Comparative Example 4 A soft cold cure foam was produced in the same manner as in Example 5 except that no additive was used. The evaluation results are shown in Table 2.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

EFFECTS OF THE INVENTION Even in a formulation that does not use CFC, it has an effect of obtaining a foam having a good curing property and a low compression set. Further, it is possible to prevent an increase in hardness due to water foaming.

Continuation of front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area C08L 75:04

Claims (2)

[Claims] 1. When a flexible polyurethane foam is produced from a polyhydroxy compound, an organic polyisocyanate, a catalyst, a foam stabilizer, water as a foaming agent and an additive, the additive is selected from the following (A) to (E). At least one additive to the polyhydroxy compound is 0.1 to
A method for producing a flexible polyurethane foam, which comprises using 15% by weight. (A) Castor oils and / or derivatives thereof (B) RCOO- [CH ₂ -CH (CH ₃ ) -O] _k -COR ¹ k = ^{1 to} 60, R, R ¹ = C _{1 to} C ₃₀ carbonization hydrogen group _{(C) H 2 C = C} (CH 3) -COO- (CH 2 -CH 2 -O) m -CH 3 m = 1~25 (D) R 2 -COO-R 3 R 2 = C 5 To C ₂₅ hydrocarbon group R ³ = C _{1 to} C ₁₅ hydrocarbon group (E) R ⁴ COO- (CH ₂ ) _n -OCOR ⁵ n = 1 to 10, R ⁴ , R ⁵ = C _{5 to} C ₂₅ hydrocarbon radicals 2. A polyoxyalkylene-based polyol in which 80% by weight or more of the polyhydroxy compound contains a polyoxyalkylene-based polyol and / or polymer fine particles,
The method for producing a flexible polyurethane foam according to claim 1.