JPH07292057A - Production of flexible polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain a flexible polyurethane foam improved in strength and extensibility by reacting a polyisocyanate compound with an active hydrogen compound containing a specific ester-modified polyether polyol in the presence of a catalyst, a foaming agent and a foam stabilizer. CONSTITUTION:When a flexible polyurethane foam is produced by reacting an active hydrogen compound and a polyisocyanate compound in the presence of a catalyst, a foaming agent and a foam stabilizer, a specific ester-modified polyether polyol with a molecular weight of 1,000 or more is employed in an amount of 30-100wt.% based on the total amount of the active hydrogen compound. This ester-modified polyether polyol is obtained by polymerizing polyoxyalkylene polyol first with 2-10 moles of each of a polycarboxylic anhydride and a cyclic ether compound, and then with 2-10 moles of a cyclic ether compound. It is preferred that the ester-modified polyether polyol and an aromatic active hydrogen compound be employed in amounts of 30-99wt.% and 1-20wt.%, respectively, based on the total amount of the active hydrogen compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high-strength, high-stretch flexible polyurethane foam.

[0002]

2. Description of the Related Art Conventionally, a polyester-based flexible polyurethane foam using a polyester-based polyol has been known as a high-strength and highly-extensible flexible polyurethane foam. However, it is known that the polyester-based flexible polyurethane foam is slightly inferior in elasticity and hydrolysis resistance.

A method for producing a highly stretchable flexible polyurethane foam composed of polyether polyol and organic isocyanate is known (Japanese Patent Laid-Open No. 286707/1990). However, it is known that the conventional high-stretch flexible polyurethane foam has an initial tensile strength reduced by about 50% as compared with the polyester-based flexible polyurethane foam.

[0004]

SUMMARY OF THE INVENTION The present invention provides a high-strength, high-stretch flexible polyurethane polyurethane foam which solves the problems of hydrolyzability and suppression of reduction in initial tensile strength of the prior art. A manufacturing method is provided.

[0005]

The present invention is the following invention made to solve the above-mentioned problems.

In producing a flexible polyurethane foam by reacting an active hydrogen compound and a polyisocyanate compound in the presence of a catalyst, a foaming agent and a foam stabilizer, a polyoxyalkylene polyol is added with a polycarboxylic acid anhydride and a cyclic ether compound, respectively. After polymerizing 2 to 10 moles,
A method for producing a flexible polyurethane foam, which comprises using an ester-modified polyether polyol having a molecular weight of 1000 or more obtained by polymerizing only 2 to 10 moles of a cyclic ether compound with respect to the total amount of active hydrogen compounds in an amount of 30 to 100% by weight.

In producing a flexible polyurethane foam by reacting an active hydrogen compound and a polyisocyanate compound in the presence of a catalyst, a foaming agent and a foam stabilizer, a polycarboxylic acid anhydride and a cyclic ether compound are added to a polyoxyalkylene polyol, respectively. After polymerizing 2 to 10 moles,
An ester-modified polyether polyol having a molecular weight of 1000 or more obtained by polymerizing only 2 to 10 moles of a cyclic ether compound is 30 to 99% by weight based on the total amount of active hydrogen compounds, and an aromatic active hydrogen compound is based on the total amount of active hydrogen compounds. 1 to 20% by weight of the flexible polyurethane foam.

The ester-modified polyether polyol used in the present invention comprises a polyoxyalkylene polyol, a polycarboxylic acid anhydride and a cyclic ether compound each of 2
After polymerizing 10 to 10 moles, only the cyclic ether compound is added to 2
It is an ester-modified polyether polyol having a molecular weight of 1000 or more obtained by polymerizing 10 to 10 moles.

The polyoxyalkylene polyol is obtained by reacting a cyclic ether compound in the presence of a catalyst with an active hydrogen compound such as a polyhydric alcohol, a polyamine compound or an alkanolamine as an initiator. Examples of the cyclic ether compound include alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide, glycidyl ether, and glycidyl ester. Alkylene oxide is particularly preferable, and propylene oxide is most preferable among them.

Examples of the catalyst include hydroxides, oxides and salts of alkali metals and alkaline earth metals, complex metal cyanide complex catalysts and other organic metal compounds. A complex metal cyanide complex catalyst is particularly preferable.

After the production of polyoxyalkylene polyol, the catalyst used for polymerizing the cyclic ether may be used as it is to polymerize the polycarboxylic acid anhydride and the cyclic ether compound. In this case, the catalyst is preferably a double metal cyanide complex catalyst.

The molecular weight of the polyoxyalkylene polyol is preferably 700 to 1200.

The polycarboxylic acid anhydride and the cyclic ether compound which are polymerized first are preferably polymerized simultaneously. It is particularly preferable to carry out random polymerization by polymerizing at the same time. At this time, 2 to 10 moles,
It is particularly preferable to polymerize 3 to 7 mol. Next, only the cyclic ether compound is polymerized, and at this time, it is preferable to polymerize 2 to 10 mol, particularly 3 to 7 mol.

Specific examples of the polycarboxylic acid anhydride include phthalic acid, trimellitic acid, pyromellitic acid, methylendomethylenetetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, chlorendic acid, maleic acid and the like. Is mentioned. Particularly preferred are dicarboxylic acid anhydrides, and most preferred are phthalic anhydride and maleic anhydride.

Examples of the cyclic ether compound include the above-mentioned cyclic ether compounds, and alkylene oxide is particularly preferable, and among them, propylene oxide, ethylene oxide, and a combination of propylene oxide and ethylene oxide is preferable.

In reacting the polyoxyalkylene polyol with the polycarboxylic acid anhydride and the cyclic ether compound, it is preferable to use a catalyst. Such catalysts include tertiary amines, quaternary ammonium salts, hydroxides, oxides and salts of alkali metals and alkaline earth metals, complex metal cyanide complex catalysts and other organometallic compounds, or other Usually, an esterification catalyst and the like can be mentioned. A complex metal cyanide complex catalyst is particularly preferable. Further, the catalyst used for producing the polyoxyalkylene polyol may be used as it is.

The molecular weight of the ester-modified polyether polyol in the present invention is 1,000 to 5,000, particularly 150.
It is preferably 0 to 3500. Molecular weight is 1000
If it is less than 1, the initial tensile strength will be good, but the elongation will be small, and it will be difficult to obtain the desired highly stretchable foam, which is not preferable. When the molecular weight is 1000 or more,
Urethane foam with high mechanical strength, especially tensile strength and elongation can be obtained. The upper limit of the molecular weight of the ester-modified polyether polyol is 5000.

In the present invention, the ester-modified polyether polyol is used in an amount of 30 to 1 based on the total amount of active hydrogen compounds.
Used in an amount of 100% by weight (however, when the following aromatic active hydrogen compounds are used in combination, 30 to 99% of all active hydrogen compounds are used).
Use by weight). When the amount is less than 30% by weight, the content of ester bonds in the flexible polyurethane foam becomes thin. Therefore, the strength of the chemical bond energy in the ester bond is a major factor of the mechanical strength, and the initial tensile strength decreases.

In the present invention, it is more preferable to use the aromatic active hydrogen compound in combination with the ester-modified polyether polyol. As the aromatic active hydrogen compound,
It is preferable that (1) a compound having a molecular weight of 200 to 600 obtained by polymerizing a cyclic ether compound with an aromatic dihydroxy compound or (2) an aromatic amine compound.

A compound obtained by adding a cyclic ether to an aromatic dihydroxy compound is bisphenol A.
The compounds obtained by ring-opening polymerization of the above-mentioned alkylene oxide are mentioned. When a compound having a molecular weight of less than 200 is used, the action as a cross-linking agent becomes tough and the mechanical strength is improved, but the elongation is lowered, which is not preferable. If the molecular weight exceeds 600,
While the elongation rate is improved, the mechanical strength, especially the tensile strength tends to decrease.

Examples of aromatic amine compounds include 3,3'-dichloro-4-4'-diaminediphenylmethane, Isonol 100 (manufactured by Mitsubishi Kasei), Unilink 4200 (manufactured by Nagase & Co.) and the like.

When the aromatic active hydrogen compound is used in combination,
It is used in an amount of 1 to 20% by weight in all active hydrogen compounds. 1% by weight
If it is less than 100%, the mechanical strength, especially the initial tensile strength is significantly reduced. If it exceeds 20% by weight, the influence of the aromatic dihydroxy compound becomes large, and the elongation rate is significantly reduced.

In the present invention, an active hydrogen compound other than the above ester-modified polyether polyol and aromatic active hydrogen compound may be used. Examples of such active hydrogen compounds include polyoxyalkylene polyols and polyamine compounds. As the polyoxyalkylene polyol, the same polyoxyalkylene polyol as the polyoxyalkylene polyol used for producing the ester-modified polyether polyol can be used.
The hydroxyl value is preferably 30 to 160. Particularly, polyoxyalkylene diol having a hydroxyl value of 80 to 100 is preferable.

Since the ester-modified polyether polyol and the aromatic active hydrogen compound in the present invention have a high viscosity, the polyoxyalkylene polyol can be used in combination with a polyoxyalkylene polyol when the low-pressure foaming machine is used. It has a function of lowering the temperature and is particularly preferable in the case of a low pressure foaming machine. When a polyoxyalkylene polyol is used, it is preferably 70% by weight or less based on the total amount of active hydrogen compounds.

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

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

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 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-methylmorpholine, N-ethylmorpholine, N, N-dimethylaminoethylmorpholine, triethylamine, N,
N, N ′, N′-tetramethylhexamethylenediamine, bis (2-dimethylaminoethyl) ether, N,
N ', N'-trimethylaminoethyl ethanolamine, and the like.

These can be used in combination of two or more kinds. A preferred tertiary amine-based catalyst is triethylenediamine,
The combination of N-methylmorpholine or N-ethylmorpholine with a mixture of triethylenediamine and dipropylene glycol in a weight ratio of 1: 2, known under the trade name "abco-33LV", is particularly preferred.

The amount of the polyhydroxy compound 1 used may vary depending on the desired reaction conditions, etc.
About 0.01 to 2.0 parts by weight, preferably 0.02 to 1.5 parts by weight, relative to 00 parts by weight, is suitable.
It is suitable to use 0.1-1.0 part by weight as "co-33LV". Further, 0.5 to 1.5 parts by weight is suitable as N-methylmorpholine or N-ethylmorpholine.

The organometallic compound catalyst is most preferably an organotin compound catalyst, for example, stannas octoate, stannas laurate, dibutyltin dilaurate, dibutyltin dimaleate, dibutyltin diacetate, dioctyltin diacetate. is there. Particularly, stannas octoate and dibutyltin dilaurate 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 must be delicately changed depending on the type and reactivity of the polyol and other conditions, and various optimum ranges are relatively narrow.

Another component added to the foamable mixture is a foaming agent. Although water alone is particularly preferable as the foaming agent, a fluorinated halogenated hydrocarbon-based foaming agent and other low-boiling halogenated hydrocarbons, low-boiling hydrocarbons, inert gases and the like may be used in combination.

As the fluorinated halogenated hydrocarbon containing chlorine, 1,1-dichloro-2,2,2-trifluoroethane (R-123) and 1,1-dichloro-1-fluoroethane (R-141b) , Monochlorodifluoromethane (R-22), 1,2-dichloro-1,1,2-trifluoroethane (R-123a), 1-chloro-1,1-
Difluoroethane (R-142b), 3,3-dichloro-1,1,1,2,2-pentafluoropropane (R2
25ca), 1,3-dichloro-1,1,2,2,3-
Pentafluoropropane (R225cb), 3-chloro-1,1,2,2-tetrafluoropropane (R244
ca), 1-chloro-1,2,2,3-tetrafluoropropane (R244cb), 3-chloro-1,1,2,
2,3-pentafluoropropane (R235ca),
1,1-dichloro-1,2,2-trifluoropropane (R243cc) and the like can be used.

As a fluorinated hydrocarbon containing no chlorine,
R-134a, R-356mff, R-356mec,
R-356myp, R-245eb, R-245ca,
R-254fb or the like can be used.

Other low-boiling halogenated hydrocarbons include halogenated hydrocarbons containing no fluorine atom such as methylene chloride and fluorine-containing halogenated hydrocarbons other than the above. The inert gas may be air or nitrogen. Further, hydrocarbons having 2 to 8 carbon atoms such as propane, butane, n-pentane, isopentane, neopentane, cyclopentane, hexane and cyclohexane may be used.

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.

[0041]

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

(Polyol) Polyol A: Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst, phthalic anhydride and propylene oxide, respectively. After copolymerizing 4 mol each,
Further, an ester-modified polyether polyol having a hydroxyl value of 69.8 mgKOH / g obtained by reacting with propylene oxide.

Polyol B: Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst to phthalic anhydride and propylene oxide in an amount of 4 mol each. An ester-modified polyether polyol having a hydroxyl value of 44.9 mgKOH / g obtained by further reacting with propylene oxide after copolymerization.

Polyol C: Polyoxypropylene polyol having an average molecular weight of 1,000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst, maleic anhydride and propylene oxide each containing 4 mol each. An ester-modified polyether polyol having a hydroxyl value of 44.7 mg KOH / g obtained by further reacting with propylene oxide after copolymerization.

Polyol D: Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst to maleic anhydride and propylene oxide (4 mol each) An ester-modified polyether polyol having a hydroxyl value of 37.4 mgKOH / g obtained by further reacting with propylene oxide after copolymerization.

Polyol E: Polyoxypropylene polyol having a hydroxyl value of 112.2 mgKOH / g obtained by subjecting propylene oxide to ring-opening polymerization reaction of propylene glycol with wood ends.

Polyol F: Polyoxypropylene polyol having a hydroxyl value of 56.1 mgKOH / g, which is obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst.

Polyol G: Hydroxyl number 34.0 mgKOH / g obtained by graft-polymerizing acrylonitrile and styrene in a polyol obtained by ring-opening polymerization reaction of propylene oxide with glycerin using hexacyanocobaltate glyme complex catalyst. Polymer polyol.

Polyol H: Polyoxypropylene polyol having a hydroxyl value of 450 mgKOH / g obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst.

Polyol I: Polyester polyol having a molecular weight of 2600 and a hydroxyl value of 43.2 mgKOH / g, obtained by reacting adipic acid and diethylene glycol.

Polyol J; molecular weight 2500, which is obtained by mainly reacting adipic acid and diethylene glycol.
A polyester polyol having a hydroxyl value of 60.1 mgKOH / g.

Polyol K: Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst to phthalic anhydride and propylene oxide, 4 mol each. An ester-modified polyether polyol having a hydroxyl value of 89.6 mg KOH / g obtained by copolymerization.

Polyol M: Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst to phthalic anhydride and propylene oxide in an amount of 4 mol each. An ester-modified polyether polyol having a hydroxyl value of 52.1 mgKOH / g obtained by copolymerization.

Polyol L; Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst, maleic anhydride and propylene oxide each containing 4 mol each. An ester-modified polyether polyol having a hydroxyl value of 51.9 mgKOH / g obtained by copolymerization.

Polyol N: Polyoxypropylene polyol having an average molecular weight of 1000 obtained by subjecting propylene glycol to ring-opening polymerization reaction of propylene oxide with a hexacyanocobaltate glyme complex catalyst, maleic anhydride and propylene oxide each containing 4 mol each. An ester-modified polyether polyol having a hydroxyl value of 42.3 mgKOH / g obtained by further reacting with propylene oxide after copolymerization.

(Crosslinking agent) Crosslinking agent P: hydroxyl value 280 mgKOH / obtained by ring-opening polymerization reaction of propylene oxide with bisphenol A
g of polyoxypropylene polyol.

(Example 1) 40 parts of polyol A, 50 parts of polyol E, 10 parts of crosslinking agent K, 4.0 parts of water,
Amine catalyst [Dabco-33LV (manufactured by Sankyo Air Products) 0.3 part and N-methylmorpholine 1.0
Part], foam stabilizer SRX-298 (manufactured by Toray Dow Silicone)
To a mixture of 1.0 part and 0.1 part stanna octoate was added TDI-80 (2,4-TDI / 2,6-TDI = 8.
0/20 mixture) was mixed under the conditions of a liquid temperature of 25 ° C. and an isocyanate index of 105.

Next, 300 mm × 300 mm × 300 mm
Foaming was performed using the mold. The physical properties of the foam were evaluated and the results are shown in Table 3.

(Examples 2 to 6) Instead of the polyol A and the polyol E, the polyols shown in Table 1 were used, except that
Foaming was carried out with the same formulation as in Example 1 and the physical properties of the foam were evaluated. The evaluation results are shown in Tables 3-4.

Comparative Example 1 60 parts of polyol F, 34 parts of polyol G, 6 parts of polyol H, 2.65 of water
Parts, amine catalysts [Dabco-33LV and 1.0
Parts, N-methylmorpholine 0.7 parts], a foam stabilizer SRX-
A mixture of 2.0 parts of 298 and 0.2 parts of stanna octoate was mixed with TDI-80 under the conditions of a liquid temperature of 25 ° C. and an isocyanate index of 105. Foaming was carried out in the same manner as in Example 1, and the physical properties were measured. The results are shown in Table 4.

Comparative Examples 2 and 3 100 parts of Polyol I (Comparative Example 2) or Polyol J (Comparative Example 3), 4.0 parts of water, 1.0 part of amine catalyst N-methylmorpholine,
Foam stabilizer PRX-607 (manufactured by Toray Dow Silicone) 1.0
TD to a mixture of 1 part and 0.1 part stanna octoate
I-80 liquid temperature 25 ℃, isocyanate index 1
It mixed on the conditions of 05. Foaming was carried out in the same manner as in Example 1, and the physical properties were measured. Moreover, it carried out similarly about the polyol J. The results are shown in Table 4.

(Comparative Examples 4 to 9) Instead of the polyols A and E, the polyols shown in Table 2 were used.
Foaming was carried out with the same formulation as in Example 1 and the physical properties of the foam were evaluated. The evaluation results are shown in Tables 4-5.

[0063]

[Table 1]

[0064]

[Table 2]

[0065]

[Table 3]

[0066]

[Table 4]

[0067]

[Table 5]

[0068]

EFFECT OF THE INVENTION A high-strength, highly stretchable flexible polyurethane foam can be obtained by the production method of the present invention. By using the ester-modified polyether polyol and the aromatic active hydrogen compound, the mechanical strength, particularly the initial tensile strength, is equivalent to that of the polyester foam, and the elongation rate can be imparted. It can be used as a substitute for an ester foam such as a rubber-like elastic material.

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Claims (3)

[Claims] 1. A method for producing a flexible polyurethane foam by reacting an active hydrogen compound and a polyisocyanate compound in the presence of a catalyst, a foaming agent and a foam stabilizer, polyoxyalkylene polyol, polycarboxylic acid anhydride and cyclic ether compound. After polymerizing 2 to 10 moles of
A method for producing a flexible polyurethane foam, which comprises using an ester-modified polyether polyol having a molecular weight of 1000 or more obtained by polymerizing only 2 to 10 moles of a cyclic ether compound with respect to the total amount of active hydrogen compounds in an amount of 30 to 100% by weight. 2. In producing a flexible polyurethane foam by reacting an active hydrogen compound and a polyisocyanate compound in the presence of a catalyst, a foaming agent and a foam stabilizer, a polyoxyalkylene polyol, a polycarboxylic acid anhydride and a cyclic ether compound are used. After polymerizing 2 to 10 moles of
An ester-modified polyether polyol having a molecular weight of 1000 or more obtained by polymerizing only 2 to 10 moles of a cyclic ether compound is 30 to 99% by weight based on the total amount of active hydrogen compounds, and an aromatic active hydrogen compound is based on the total amount of active hydrogen compounds. 1 to 20% by weight of the flexible polyurethane foam. 3. The aromatic active hydrogen compound is (1) a compound having a molecular weight of 200 to 600 obtained by polymerizing a cyclic ether compound with an aromatic dihydroxy compound, or (2).
The production method according to claim 2, which is an aromatic amine compound.