JPH09208661A - Polyisocyanate composition, method for producing flexible polyurethane foam using the same, and method for producing flexible polyurethane foam molded article - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: Even if a special polyol, a special organic polyisocyanate, or a combination thereof is not used, a foam molded article has a good appearance (especially in cold cure molding) and has an extremely low defect rate. Provided is a method capable of producing a polyurethane foam or a molded article thereof, and a polyisocyanate composition used therein. A polyisocyanate composition containing an organic polyisocyanate and an organic polysiloxane.
And it is a method for producing a flexible polyurethane foam or a molded article thereof, which comprises reacting this polyisocyanate composition with a polyol composition containing a long-chain polyol, a foaming agent, a catalyst and a foam stabilizer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flexible polyurethane foam having a good appearance and a low defective rate, a method for producing a foam molded article, and a polyisocyanate composition used therefor.

[0002]

2. Description of the Related Art Generally, when a flexible polyurethane foam is produced by using an organic polyisocyanate and a polyol, a foam stabilizer is used as one of additives in addition to a foaming agent and a catalyst. That is, JP-A-2-1421
No. 0 discloses the use of relatively high equivalent weight polyols, blowing agents, high functionality polyether polyols, and polyols to produce (semi) flexible polyurethane foams with low shrinkage and deformation, for example siloxane / polyene. Techniques for stabilizing these reaction mixtures with the use of surfactants such as (alkylene oxide) copolymers have been disclosed. Further, in Japanese Patent Laid-Open No. 6-228266,
In order to produce a polyurethane foam that has a good skin layer and good surface smoothness and elongation without using chlorofluorocarbon as a foaming agent, it is specified as a specific high molecular weight polyol and a specific low molecular weight active hydrogen compound. There is disclosed a technique of using a foam stabilizer, such as a polydimethylsiloxane-polyalkylene oxide block polymer, in addition to the foaming agent and the catalyst when the polyisocyanate is reacted. In these techniques, a surfactant and a foam stabilizer are used by always blending them in a polyol, because the stability of the blending agent in the organic polyisocyanate is significantly lowered.

[0003]

However, the appearance of the flexible polyurethane foam molded article manufactured by the above-mentioned conventionally known method, especially the soft polyurethane foam molded article manufactured by the cold cure mold, is not always satisfactory, and its improvement is improved. Is required.

The present invention allows the use of special polyols, especially in cold cure molding.
An object of the present invention is to provide a method capable of producing a flexible polyurethane foam having a good appearance of a foam molded article and having an extremely low defect rate, a method for producing a foam molded article, and a polyisocyanate composition used therefor.

[0005]

Means for Solving the Problems As a result of earnest research, the present inventors have found that a specific compound among compounds used as a foam stabilizer is mixed with a specific organic polyisocyanate and reacted with a polyol or the like. As a result, it is possible to improve the mixing property of the organic polyisocyanate and the polyol, especially during cold cure molding, and as a result, the cell stability of the foam is improved, and the foam molded article has a good appearance and a low defect rate. The inventors have found that a flexible polyurethane foam can be produced, and completed the present invention.

That is, the polyisocyanate composition of the present invention is a polyisocyanate composition containing an organic polyisocyanate and an organic polysiloxane, wherein the organic polyisocyanate comprises diphenylmethane diisocyanate-based polyisocyanate and tolylene diisocyanate. Diisocyanate-based polyisocyanate / tolylene diisocyanate = 0.1-10.
It is characterized in that it is contained in a weight ratio of 0.

The method for producing a flexible polyurethane foam of the present invention is characterized in that a polyol composition containing a long-chain polyol, a foaming agent, a catalyst and a foam stabilizer is reacted with the above polyisocyanate composition. .

Further, in the method for producing a flexible polyurethane foam molded article of the present invention, a polyol composition containing a long-chain polyol, a foaming agent, a catalyst and a foam stabilizer is reacted with the above polyisocyanate composition in a mold. It is characterized by

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The organic polyisocyanate used in the present invention is a mixture of diphenylmethane diisocyanate (MDI) type polyisocyanate and tolylene diisocyanate (TDI), the ratio of which is MD.
I-type polyisocyanate / TDI = 0.1-10.0
(Weight ratio), preferably 0.5 to 9.0 (weight ratio). This MDI-based polyisocyanate is 2,2'-M
4,4'-MDI which may contain DI and / or 2,4'-MDI (hereinafter abbreviated as isomer-containing MDI) or a mixture of this urethane modified product (isocyanate prepolymer) and Polymek MDI Is. Polymeric MDI is polynuclear (polyphenylene polymethylene polyisocyanate) 55-70 wt% and binuclear (M
DI) in an amount of 45 to 30% by weight and containing 4,4 'in the binuclear body.
Most preferred are those containing 10 to 30% by weight of isomers other than MDI. In order to achieve the object of the present invention, isomer-containing MDI / TDI = 0.1 to 3.5 (weight ratio) is preferable, and 0.5 to 2.5 (weight ratio) is particularly preferable.
Polymeric MDI / TDI = 0.1 to 5.0 (weight ratio) is preferable, and 0.2 to 4.0 (weight ratio) is particularly preferable. In addition, polymeric MDI / isomer-containing MDI =
0.3-3.0 (weight ratio) is preferable, and especially 0.4-
2.5 (weight ratio) is preferable.

In the present invention, the organic polysiloxane compounded in the organic polyisocyanate is an organic compound having a Si--O bond in the molecule, and examples thereof include silicone oil. Organic polysiloxanes include those containing active hydrogen groups and those not containing active hydrogen groups, but from the viewpoint of stability of solutions when blended with organic polyisocyanates,
Those containing no active hydrogen group are preferred. In particular,
Union Carbide L-5340, Torre Silicone SH-193, Toshiba Silicone TFA-4
202 etc. can be mentioned. The amount of the organic polysiloxane used is 0.05 in the polyisocyanate composition in order to ensure the stability of the blended solution with the organic polyisocyanate and to improve the appearance when a polyurethane foam or a foam molded article is formed. ~ 3 wt% is preferred.

The long-chain polyol used in the production of the flexible polyurethane foam or the foam molded article of the present invention has a molecular weight of 600 to 10,000, particularly 1000 to 800.
It is preferably 0, and the number of functional groups is preferably 2-8. Examples of such long-chain polyols include polyether polyols, polyester polyols, polycarbonate polyols, polyether ester polyols, and lactone polyester polyols. These can be used alone or in combination of two or more. When the molecular weight of the long-chain polyol is less than 600, the polyurethane foam or foam molded product produced becomes hard and brittle, and it is difficult to obtain a flexible and sufficiently strong foam or foam molded product. From the viewpoint of such performance, polyether polyol and polyester polyol are particularly preferable.

As the polyether polyol, for example, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1 , 5-pentanediol, 1,7-heptanediol, glycerin, trimethylolpropane, trimethylolethane, hexane-1,2,6-triol,
α-methyl glucoside, pentaerythritol, sorbitol, sugar-based alcohols such as sucrose, glucose and fructose, bisphenol A,
Using one or more compounds having two or more active hydrogen atoms such as ethylenediamine, propylenediamine, diethylenetriamine, toluenediamine, metaphenylenediamine, diphenylmethanediamine and xylenediamine as an initiator, ethylene oxide, propylene oxide and butylene oxide. , Amylene oxide, glycidyl ether, methyl glycidyl ether, tert
-Butyl glycidyl ether, phenyl glycidyl ether, and the like produced by addition-polymerizing one or more kinds of monomers by a known method. Of these, pentaerythritol-based polyether polyols are particularly preferable from the viewpoints of flexibility and strength of the obtained foam or foam molded product. Examples of polyester polyols include condensation type polyester polyols obtained from an acid and an alcohol by a known method. Condensed polyester polyols include, for example, adipic acid, sebacic acid, terephthalic acid,
Saturated or unsaturated dibasic acids such as isophthalic acid, maleic acid, and fumaric acid; acid anhydrides such as maleic anhydride and phthalic anhydride; dialkyl esters such as dimethyl terephthalate; and ethylene glycol, propylene glycol, butylene glycol , Diethylene glycol, dipropylene glycol, neopentyl glycol, 1,6
A polyester polyol obtained by a condensation reaction with a glycol such as hexylene glycol. Specific examples include adipate-based polyols consisting of one type of acid and one type of glycol such as polyethylene adipate polyol, polybutylene adipate polyol, polyhexylene adipate polyol, polyethylene butylene adipate polyol, polyethylene diethylene adipate polyol, polyhexylene neo. Aromatic polyester polyols such as pentylene adipate polyols and other adipate-based polyols consisting of many kinds of glycols, polyethylene adipate terephthalate polyols and polyethylene adipate isophthalate polyols consisting of many kinds of acids and one kind of glycols And so on. Examples of the polycarbonate polyol include hexane glycol, 3-methyl-1,
Examples thereof include compounds obtained by reacting 5-pentanediol, 1,4-cyclohexanedimethanol and the like with diethyl carbonate, diphenyl carbonate and the like. Examples of the polyether ester polyol include compounds obtained by reacting the above polyether polyol as a polyol component with an aliphatic or aromatic dicarboxylic acid. The lactone-based polyester polyol can be obtained by ring-opening polymerization of lactones such as ε-caprolactone and γ-butyrolactone. Depending on the type of the initiator, various lactone polyester polyols can be obtained. Examples of the initiator include glycols such as ethylene glycol and butylene glycol, polyether polyols such as polyoxypropylene glycol (PPG) and polyoxytetramethylene glycol (PTMG), and condensation-type polyester polyols such as adipate. Can be mentioned. Further, a polymer polyol obtained by graft-polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene or methyl methacrylate to the above polyether polyol or polyester polyol can also be used.

As the foaming agent to be added to the long-chain polyol for producing the flexible polyurethane foam or the foam molded article of the present invention, known chemical foaming agents and / or physical foaming agents are used in a usual amount. be able to. For example, a low boiling point inert solvent such as acetone, pentane or hexane, a CFC substitute such as HCFC-141b or 123, or water can be used to obtain a flexible polyurethane foam or a foam molded article which is the object of the present invention. As the foaming agent in the production of flexible polyurethane foam or foam molded article, usually water as a carbon dioxide gas generating agent,
Generally, chlorofluorocarbons and low boiling point solvents are used together as an auxiliary foaming agent to reinforce the foaming action of water, but the use of chlorofluorocarbons has been criticized worldwide due to the problem of ozone layer depletion. Therefore, in the present invention, it is preferable to use water alone as the foaming agent. The water content is preferably 2 to 10 parts by weight, more preferably 3 to 8 parts by weight, based on 100 parts by weight of the long-chain polyol.

Any known urethane-forming catalyst can be used as the catalyst to be blended with the long-chain polyol, and there is no particular limitation. For example, as the amine-based urethane-forming catalyst, triethylamine, tripropylamine, triethylamine Isopropanolamine, tributylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N, N-dimethylethanolamine, diethylenetriamine , N,
N, N ', N'-tetramethylethylenediamine, N,
N, N ', N'-tetramethylpropylenediamine,
N, N, N ', N'-tetramethylbutylenediamine,
N, N, N ', N'-tetramethylhexamethylenediamine, bis [2- (N, N-dimethylamino) ethyl]
Ether, N, N-dimethylbenzylamine, N, N-
Dimethylcyclohexylamine, N, N, N ', N',
N ″ -pentamethyldiethylenetriamine, triethylenediamine, salts of triethylenediamine, oxyalkylene adducts of amino groups of primary and secondary amines, N, N
An azacyclo compound, such as a dialkylpiperazine,
Various N, N ′, N ″ -trialkylaminoalkylhexahydrotriazines, β-aminocarbonyl catalysts described in JP-B-52-43517, JP-B-53-14
There is a β-aminonitrile catalyst described in Japanese Patent No. 279, and the like,
Examples of the organometallic urethane-forming catalyst include tin acetate, tin octoate, tin oleate, tin laurate, dibutyltin dichloride, lead naphthenate, nickel naphthenate and cobalt naphthenate. These catalysts are used alone or as a mixture. The amount of the catalyst blended is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the long-chain polyol.

Examples of the foam stabilizer incorporated in the long-chain polyol include ethylene oxide, propylene oxide,
Illustrating those obtained by condensing a polyglycol ether containing the required number of alkylene oxides such as butylene oxide, preferably ethylene oxide, with an organic compound containing at least one reactive hydrogen atom. You can At least one such
Examples of the organic compound containing one reactive hydrogen atom include alcohols, phenols, thiols, primary or secondary amines, carboxylic acids or sulfonic acids, nonionic surfactants which are amides thereof, and one or more. And a polyalkylene oxide derivative of a phenolic compound having an alkyl-substituted group. Further, preferred foam stabilizers in the present invention may include pluronic type surfactants, such as butylene oxide, amylene oxide, phenylethylene oxide, cyclohexene oxide, propylene oxide, or a mixture thereof. By polymerizing 1,2-alkylene oxide or substituted alkylene oxide in the presence of an alkali catalyst,
It is a nonionic surfactant obtained by producing a corresponding water-insoluble polyalkylene glycol and condensing it with the required number of moles of ethylene oxide under the same conditions. Furthermore,
The required number of moles of the alcohol obtained by reducing the aldehyde produced by the catalytic reaction of polyolefin such as tripropylene, tetrapropylene, pentapropylene, ditributylene, triisobutylene, propyleneisobutylene and tributene with carbon monoxide and hydrogen. And a nonionic surfactant obtained by reacting ethylene oxide with. Further, the organic polysiloxane blended with the organic polyisocyanate can also be mentioned as an example of a preferable compound of the foam stabilizer blended with the long-chain polyol. The amount of the foam stabilizer added to the long-chain polyol is preferably 3 parts by weight or less based on 100 parts by weight of the long-chain polyol.

In the method for producing a flexible polyurethane foam or a foam molded article of the present invention, it is preferable that the polyol composition and the polyisocyanate composition are reacted at an isocyanate index of 80 to 110, particularly 8
5 to 105 are preferable. This reaction is, for example, 20 to 3
Mix both compositions at 0 ° C. and stir for 2-6 seconds, then 4
It can be carried out in a mold at 0 to 70 ° C.

In the present invention, emulsifiers, antioxidants and antioxidants such as ultraviolet absorbers, fillers such as calcium carbonate and barium sulfate, flame retardants, plasticizers,
Various known additives such as colorants and antifungal agents, auxiliaries and the like can be used in combination as necessary.

[0018]

As described above, the flexible polyurethane produced by the method of the present invention using the polyisocyanate composition of the present invention which is excellent in solution stability despite containing the organic polysiloxane. The foam or foam molded product has a good appearance and a very low defect rate. In particular, when the present invention is applied to cold cure molding, the performance of the obtained flexible polyurethane foam and foam molded product is remarkably excellent.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, parts and% represent parts by weight and% by weight, respectively, unless otherwise specified. [Preparation of Organic Polyisocyanate] Production Example 1 Polyisocyanate (1) and Polyols (1) and (2)
And (4) were reacted at 70 ° C. for 3 hours to obtain an isocyanate prepolymer. Next, polyisocyanates (2) and (3) were added thereto and mixed to obtain an organic polyisocyanate (a). Table 1 shows the raw material composition and the isocyanate (NCO) content and viscosity of the organic polyisocyanate (a).

Production Example 2 Polyols (1), (2) and (4) in Production Example 1
An organic polyisocyanate (b) was obtained in the same manner except that the polyols (3) and (4) were used instead of.
The raw material composition and NCO content and viscosity of the organic polyisocyanate (b) are summarized in Table 1.

[0021]

[Table 1] In Table 1, polyisocyanate (1): MDI containing 18% isomer Polyisocyanate (2): 60% polynuclear body, MDI40
%, 15% isomer in MDI Polyisocyanate (3): TDI (Coronate T-8)
0, manufactured by Nippon Polyurethane Industry) Polyol (1): molecular weight 8000, functional group number 4, polyether polyol Polyol (2): molecular weight 2000, functional group number 2, polyether polyol Polyol (3): molecular weight 1000, functional group number 2, poly Ether polyol Polyol (4): molecular weight 2550, functional group number 2, polyester polyol

Preparation of Polyol Preliminary Composition Production Example 3 Polyols (6), (9) and (10), catalysts (1) and (3), and water were added in this order and mixed to prepare a polyol preliminary composition. I got (a). The raw material compositions are summarized in Table 2.

Production Example 4 Polyols (5), (6), (7) and (8), catalysts (1) and (2), and water were added in this order and mixed to prepare a polyol preliminary composition (b). Obtained. The raw material compositions are summarized in Table 2.

[0024]

[Table 2] In Table 2, polyol (5): molecular weight 7,000, functional group number 3, polyether polyol Polyol (6): molecular weight 7,000, functional group number 4, polyether polyol Polyol (7): polymer polyol consisting of acrylonitrile and styrene Polyol (8 ): Molecular weight 1500, functional group 3, polyether polyol Polyol (9): Molecular weight 6000, functional group 3, polyether polyol Polyol (10): Polymer polyol consisting of acrylonitrile Catalyst (1): TEDA L-33, manufactured by Tosoh Corporation Catalyst (2): Toyocat ET, manufactured by Tosoh Catalyst (3): Toyocat ETF, manufactured by Tosoh

Examples 1 to 9 (1) Preparation of Polyisocyanate Composition Mixing the organic polyisocyanate (a) or (b) obtained in Production Example 1 or 2 with an organic polysiloxane,
A polyisocyanate composition was prepared. (2) Preparation of polyol composition Preliminary composition of polyol (a) obtained in Production Example 3 or 4
Alternatively, (b) was mixed with an organic polysiloxane as a foam stabilizer to prepare a polyol composition. (3) Manufacture of flexible polyurethane foam and foam molded product Polyisocyanate composition and polyol composition are each used in 2 parts.
Adjust to 5 ℃, isocyanate index 85-10
Weighed to 5 and mixed with a lab mixer for 5 seconds. This was poured into a mold which had been heated to 60 ° C. in advance to cause foaming, and after 5 to 6 minutes, the mold was removed to obtain a soft polyurethane mold foam molded article. In the case of free foaming, the mixture was mixed for 5 seconds by a lab mixer, and this was poured into a cardboard in which a polyethylene sheet was set to obtain a flexible polyurethane free foam. Regarding the performance of the obtained flexible polyurethane foam and the foam molded article, the cell state of the free foam and the appearance of the molded foam molded article were evaluated. Tables 3 and 4 collectively show the raw material composition, formulation, foam and foaming behavior and performance of the foam molded article.

Comparative Examples 1 to 6 Flexible polyurethane foams and foam molded products were produced in substantially the same manner as in the above Examples except that the organic polyisocyanate was not mixed with the organic polysiloxane. Table 5 summarizes the raw material composition, blending, foam and foaming behavior and performance of the foam molded article.

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5] In Tables 3 to 5, L-5309: made by Nippon Unicar, organic polysiloxane SZ-1306: made by Nippon Unicar, organic polysiloxane L-5366: made by Nippon Unicar, organic polysiloxane Sinking rate: at the highest foam height during foaming Top height: Maximum foam height during foaming [Measurement method of performance of flexible polyurethane foam and foam molded products] In the case of free foam, change the cell state to mold foam (molded product) In the case of), the appearance was visually evaluated. Judgment criteria; ◎: Very good, ○: Good, △: Poor, ×: Remarkably bad

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location C08G 101: 00) (72) Inventor Takao Fukami 4-20-20 Kugenuma Kaigan, Fujisawa City, Kanagawa Prefecture (72) ) Inventor Kazuki Sasaki 1379-2 Shimbashicho, Izumi-ku, Yokohama-shi, Kanagawa

Claims (3)

[Claims] 1. A polyisocyanate composition containing an organic polyisocyanate and an organic polysiloxane, wherein the organic polyisocyanate comprises diphenylmethane diisocyanate-based polyisocyanate and tolylene diisocyanate and diphenylmethane diisocyanate-based polyisocyanate / tolylene diisocyanate. = 0.1
The polyisocyanate composition is contained in a weight ratio of 10.0. 2. A method for producing a flexible polyurethane foam, which comprises reacting a polyol composition containing a long-chain polyol, a foaming agent, a catalyst and a foam stabilizer with the polyisocyanate composition according to claim 1. . 3. A flexible polyurethane foam characterized in that a polyol composition containing a long-chain polyol, a foaming agent, a catalyst and a foam stabilizer is reacted with the polyisocyanate composition according to claim 1 in a mold. Molded article manufacturing method.