JPH07133337A - Thermosetting urethane resin composition and production of molding therefrom - Google Patents

Abstract

PURPOSE:To obtain the title compsn. which, when subjected to reaction molding, gives a molding excellent in mold release characteristics, surface smoothness, and adhesion to a coating film by combining an NCO-terminated prepolymer modified with a specific modifier with a curative contg. a catalyst in a specified equivalent ratio of the prepolymer to the curative. CONSTITUTION:The compsn. comprises 1 equivalent of an NCO-terminated prepolymer modified with a polysiloxane of the formula Me is methyl; n is an integer of 1-100; X is an integer of 1-3 and Y is an integer of 0-2 provided X+Y is 3; and R is an alkylene group optionally interrupted by one or more alkyleneoxy groups) having a diol group at one molecular terminal or modified with a mixture of the polysiloxane with an active hydrogen compd. having a mol.wt. of 62-1,200 and 1.20-5.00 equivalents of a curative comprising an active hydrogen compd. (e.g. a polyether polyol) and a catalyst (e.g. an organometallic compd. or a tert. amine). The compsn. is subjected to reaction molding to give a molding, pref. with a reaction injection molding machine.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a composition for thermosetting urethane resin. More specifically, the present invention relates to a composition for a thermosetting urethane resin, which is a composition comprising a specific NCO group-terminated prepolymer and a curing agent, and has excellent demolding property, surface smoothness, and adhesion in coating.

[0002]

2. Description of the Related Art Thermoset urethane moldings are widely used for manufacturing automobiles, furniture, electric appliances and the like. Further, since the reaction stock solution is a liquid, it is easy to manufacture a product having a complicated shape, and its moldability and physical properties can be arbitrarily adjusted by adding a urethanization catalyst, selecting a curing agent component, etc. Therefore, further expansion of its application fields is expected in the future.

[0003]

However, in the production of this thermosetting urethane resin, a method of applying various release agents in advance has been conventionally used to release the molded article after the reaction molding from the surface of the mold cavity. Came. This step lengthens the time required for molding and makes it difficult to improve productivity. Furthermore, in the molding of ultra-high hardness products, cracks, breaks, etc. occurred in the molded product during release, and a good molded product could not be obtained. Regarding these problems, a method of imparting self-releasing property to a molded product by already using a fatty acid metal salt as a part of a curing agent (Japanese Patent Publication No.
-52056) or a polysiloxane derivative as a part of a curing agent to impart self-releasing property (Patent Document 1)
59-149919), etc., but there were problems such as deterioration of surface properties during continuous molding and deterioration of adhesion between paint and resin surface when post-coating on molded products.

[0004]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors for the purpose of improving productivity by improving demoldability in conventional thermosetting urethane resin molding, as a result, a specific one-terminal diol polysiloxane or By reacting and molding the NCO group-terminated prepolymer containing the mixture of the one-end diol polysiloxane and the active hydrogen compound having a molecular weight of 62 to 12000 and the curing agent containing the catalyst at a specific equivalent ratio,
It has been found that a thermosetting urethane resin molding composition having excellent demolding property, surface smoothness, and excellent adhesion in coating can be obtained, and has reached the present invention. That is, the present invention is
In a thermosetting urethane resin composition comprising (A) an NCO group-terminated prepolymer, (B) a compound having an active hydrogen group as a curing agent, and a catalyst, the (A) NCO-terminated prepolymer is used as a modifier and is represented by the following general formula: (1) a diol polysiloxane having one terminal or a mixture of the diol polysiloxane having one terminal and an active hydrogen compound having a molecular weight of 62 to 12000 and comprising (A) an NCO group-terminated prepolymer and (B) a curing agent. Equivalent ratio (A) / (B) is 1.20
A composition for thermosetting urethane resin, which is 5.00

[0005]

Embedded image (1) (wherein Me represents a methyl group, n is an integer of 1 ≦ n ≦ 100, X and Y are 1 ≦ X ≦ 3, 0 ≦ Y ≦ 2 and X
+ Y = 3 is an integer, and R represents an alkylene group which may be linked by one or two or more alkyleneoxy groups. ) And the composition, and if necessary, additives are added thereto, and the mixture is injected into a mold using a reaction injection molding machine to mold the molded product.

The NCO group-terminated prepolymer which is the component (A) of the present invention [hereinafter, abbreviated as prepolymer (A). Examples of the polyisocyanate that composes] include 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, tolidine diisocyanate,
Tolylene diisocyanate, hexamethylene diisocyanate, dodecane diisocyanate, isophorodiisocyanate, p-phenylene diisocyanate, tran
s-cyclohexane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, lysine diisocyanate, tetramethyl xylylene diisocyanate, etc.,
Derivatives obtained by modifying some of these isomers and polyisocyanates into burettes, allophanates, carbodiimides, oxazolidones, amides, imides, etc. can be used alone or in admixture of two or more. A preferred polyisocyanate is an MDI-based isocyanate.

The one-end diol polysiloxane constituting the prepolymer (A) of the present invention is the one-end diol polysiloxane represented by the general formula (1). For example,
Cilaplane FM-D-411, F manufactured by Chisso Corporation
MD-421, FM-D-425, etc. are mentioned. The molecular weight of the preferred one-end diol polysiloxane is 500
It is from 1 to 10,000.

Examples of the active hydrogen compound having a molecular weight of 62 to 12000 which constitutes the prepolymer (A) of the present invention include short chain glycol, polyether polyol, polyether polyamine and polyester polyol. Examples of the short chain glycol include ethylene. Examples thereof include glycol, propanediol, pentanediol, hexanediol, methylpentanediol, neopentyl glycol, cyclohexanedimethanol, hydroquinone-bis (2-hydroxyethyl) ether, diethylene glycol and dipropylene glycol.

As the polyether polyol, ethylene oxide or propylene oxide having a molecular weight of 200 to 200 is used.
12000 homopolymers and copolymers, polytetramethylene glycol and the like can be mentioned. Polyether polyamines include, for example, polyoxyalkylamines from Texaco Chemical, which include Jeffamine (Jeffmin).
Amine) D-230, D-2000, D-400
0, ED-600, ED-900, ED-200 in the polyether diamine having a main chain of polyethylene oxide
1, ED-4000, ED-6000 and the like, and propylene oxide-based triamines include Jeffamine T-403, T-3000, T-5000 and the like.

As the polyester polyol, for example, ethylene glycol, propylene glycol, 1,4-
Butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, deca 1 such as methylene glycol
Or two or more, malonic acid, maleic acid, succinic acid,
It is a polyester polyol containing one or more of adipic acid, glutaric acid, pimelic acid, sebacic acid, oxalic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid and the like.

Preferred active hydrogen compounds are polyether polyols, polyether polyamines and polyester polyols having a molecular weight of 400 to 12000. A more preferable molecular weight is 1,000 to 7,000. Incidentally, the polyether polyol has relatively good storage stability of the prepolymer, the polyether polyamine has good heat resistance and surface property of the molded product, and the polyester polyol has good mechanical strength of the molded product. These active hydrogen compounds can be used alone or as a mixture of two or more kinds.

The mixture of the one-end diol polysiloxane and the active hydrogen compound is a mixture containing 0.5% by weight or more of the one-end diol polysiloxane, and more preferably 1.0 to 50% by weight of the one-end diol polysiloxane. % Mixture. When the amount of the one-end diol polysiloxane is 0.5% by weight or less, the releasing property is lowered, and when it is 50% by weight or more, the obtained prepolymer (A) becomes cloudy or the storage stability is lowered.

The reaction temperature of 50 is used to produce the prepolymer (A).
˜120 ° C., and reaction time 1 to 5 hours. When using a mixture of one-end diol polysiloxane and an active hydrogen compound as a modifier, a method of charging one-end diol polysiloxane to an isocyanate whose temperature has been adjusted in advance and then charging an active hydrogen compound, one-end diol polysiloxane and active hydrogen compound There is a method of charging simultaneously with the active hydrogen compound and a method of charging the one-end diol polysiloxane after charging with the active hydrogen compound. A method of charging polysiloxane is preferable. In the method of charging the active hydrogen compound after charging the one-end diol polysiloxane, the transparency of the obtained prepolymer (A) may be lowered.

N of the prepolymer (A) used in the present invention
CO content is 6.0 to 26% by weight, preferably 1
It is 2 to 23% by weight. When the NCO content is 6.0% by weight or less, the viscosity of the prepolymer (A) becomes high, and the compounding amount with respect to the curing agent (B) becomes large, so that the mixing property with the curing agent at the time of molding is lowered, which is favorable. Molded products cannot be obtained. N
When the CO content is 26% by weight or more, the product is apt to crack at the time of demolding, and the continuous releasability is deteriorated.

The curing agent (B) used in the present invention is a mixture of an active hydrogen group-containing compound, a catalyst and, if necessary, an additive. The active hydrogen group-containing compound used for the curing agent includes a long chain active hydrogen compound, a short chain active hydrogen compound, and the like, and the long chain active hydrogen compound includes a polyether polyol, a polyether polyamine, and a polyester polyol. All of the polyether polyols, polyether polyamines, and polyester polyols listed as the active hydrogen compounds constituting the prepolymer (A) can be used. The molecular weight of the long-chain active hydrogen compound is preferably 1,000 to 7,000, and the surface properties of the resulting molded article are
Polyether polyamine is most preferable in terms of heat resistance and demolding property. Examples of the short-chain active hydrogen compound include a hydroxyl group-containing active hydrogen compound and an amine-containing active hydrogen compound.

Examples of the hydroxyl group-containing active hydrogen compound include ethylene glycol, propanediol, pentanediol, hexanediol, methylpentanediol,
Examples include neopentyl glycol, cyclohexanedimethanol, hydroquinone-bis (2-hydroxyethyl) ether, diethylene glycol dipropylene glycol and the like. Examples of the amine-containing active hydrogen compound include 2,4-bis (p-aminobenzyl) aniline,
2,4-diaminotoluene, 2,6-diaminotoluene, 1,3-phenylenediamine, 1,4-phenylenediamine, 2,4'-diaminodiphenylmethane, 4,
4'-diaminodiphenylmethane, naphthalene-1,5
-Diamine, triphenylmethane-4,4 ', 4 "-triamine, 4,4'-di (methylamino) diphenylmethane, 1-methyl-2-methylamino-4-aminobenzene, polyphenyl-polymethylene polyamine, 1,3
-Diethyl-2,4-diaminobenzene, 2,4-diaminomesitylene, 1-methyl-3,5-diethyl-2,
4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 3,5,3 ', 5'-tetraethyl-4,4'-diaminophenylmethane, 4,
4'-methylene-bis- (2,6-isopropylaniline) can be mentioned, and these can be used alone or as a mixture of two or more kinds.

In the combination of the long-chain active hydrogen compound and the short-chain active hydrogen compound which are active hydrogen group-containing compounds in the curing agent, the molecular weight of 2000 to 700 is particularly preferable.
0 polyether polyamine and aromatic diamine. The amount and type of the catalyst to be added can be selected depending on the types of the long-chain active hydrogen compound and the short-chain active hydrogen compound constituting the curing agent (B), or the type of molding machine used for molding or the shape of the mold. Examples of usable catalysts include organic metal compounds, tertiary amines, quaternary ammonium salts, alkali metal alkoxides, and carboxylic acid metal salts. Generally, when an amine-containing active hydrogen compound is used as a curing agent, a catalyst may not be required,
When any of the above compounds is selected as the long-chain active hydrogen compound and the short-chain active hydrogen compound, an isocyanate trimerization catalyst such as a tertiary amine or a carboxylic acid metal salt is used. The preferable addition amount of the catalyst is 0.01% by weight or more based on the total amount of the prepolymer (A) and the curing agent (B). More preferably, it is 0.1 to 5.0% by weight.

Additives used as necessary include
Colorants generally used in thermosetting urethane compositions, flame retardants, defoamers, antioxidants, ultraviolet absorbers, conductivity imparting agents,
A filler or the like can be used. Examples of the filler include milled glass fiber and wollastonite.

The equivalent ratio of the prepolymer (A) and the curing agent (B) used in the present invention is 1.20 to 5.00,
It is preferably 1.50 to 4.00. Equivalent ratio is 1.5
When it is 0 or less, it is difficult to sufficiently improve the releasability,
Defects such as cracks and breakages are likely to occur during the molding of ultra-high hardness products. If it is 4.00 or more, the mixing property between the prepolymer (A) and the curing agent is lowered, or the trimerization reaction of a large excess of NCO groups with respect to the active hydrogen groups in the curing agent does not proceed sufficiently. The strength immediately after molding and the surface property of the product are significantly reduced.

The thermosetting urethane molded product obtained by the present invention can be used for automobile exterior parts such as bumpers, fescias, side moldings, quarter panels, door panels and the like. Further, it can be applied to furniture, housings for electric appliances, or belts, rolls, sheets, etc. in which thermosetting urethane elastomer is generally used. Production of a molded article using the composition of the present invention, reaction injection molding,
It is possible to obtain a molded product by injecting it into a mold using a casting machine ordinarily used.

[0021]

INDUSTRIAL APPLICABILITY The present invention uses a specific one-terminal diol polysiloxane as a modifier in the prepolymer (A) in an amount of 0.5.
When the prepolymer (A) and the curing agent are contained in an amount of not less than 10% by weight and the reaction molding is carried out at a specific equivalent ratio, the continuous mold releasability can be remarkably improved, and the obtained molded product is Excellent adhesion. Furthermore, it has become possible to mold an ultra-high hardness product, which was difficult to mold by the conventional technology, in which the product cracked or cracked at the time of demolding.

[0022]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. "Parts" and "%" in the examples mean "parts by weight" and "% by weight", respectively.

The prepolymer (A) used in Examples 1 to 35 and Comparative Examples 1 to 3 was prepared by mixing the polyisocyanate, the one-end diol polysiloxane and the active hydrogen compound in the proportions shown in Tables 1 to 5 at reaction temperatures of 50 to 50. The reaction was carried out at 80 ° C. for about 3 hours.

As the one-end diol polysiloxane, FM-D-411 (molecular weight 100 is shown in the following structural formula (2).
0), FM-D-421 (molecular weight 5000), FM-D
-425 (molecular weight 10000) and an active hydrogen compound are used as an isocyanate modifier in the synthesis of the prepolymer (A), the active hydrogen compound is first charged in the pre-conditioned polyisocyanate, and then the one-end diol polysiloxane. Was charged.

[0025]

[Chemical 2] (2)

The hardeners (liquid B) used in Examples 1 to 35 and Comparative Examples 1 to 3 were prepared by mixing the catalysts in the proportions shown in Tables 1 to 5 with each active hydrogen compound previously heated and dissolved at 70 ° C. Then
The mixture was stirred for 30 minutes while keeping the temperature at 60 ° C. The resins obtained in Examples and Comparative Examples were evaluated as follows. Number of times continuous release is possible: The number of times that D-186 (manufactured by Chukyo Yushi Co., Ltd.) as an external release agent is applied to the mold only for the first time and the molded product can be released without causing skin peeling and defects such as tearing. Flexural modulus: According to JIS K 6911. Tensile strength: According to JIS K6301. Initial adhesion of coating film: Measured by the cross-cut tape method of JIS K5400.

Examples 1 to 35 and Comparative Examples 1 to 3 Prepolymer (A liquid) and curing agent (B liquid) shown in Tables 1 to 5
The molded product (W250 × D180 × H150) shown in FIG.
The reaction injection molding was carried out at an equivalence ratio of 1.00 to 4.00 using a mold capable of obtaining × d3 mm). The temperature of the prepolymer (A) and the curing agent is adjusted to 60 ± 3 ° C, and the mold temperature is 8
The temperature was adjusted to 0 ± 5 ° C. After injecting the raw material mixed solution into the mold, it was cured and demolded for the curing time shown in Tables 1 to 5. Furthermore, the surface of the molded product was washed with trichloroethane, and urethane-based primer, flexen-600 primer and urethane-based paint, flexen-101 white (both manufactured by Nippon Paint Co., Ltd.) were applied, and the initial adhesion of the coating film was evaluated. . The obtained evaluation results are shown in Tables 1-6.

Notes for Tables 1 to 5 MT: Millionate MT (MDI manufactured by Nippon Polyurethane Industry Co., Ltd.) MTL: Coronate MTL (carbodiimidated MDI manufactured by Nippon Polyurethane Industry Co., Ltd.) PPDI: p-Phenylenediisocyanate HDI: 1,6-hexamethylene diisocyanate D-4000: Jeffamine D-4000 (manufactured by Texaco Chemical) PP-4000: PP-4000 (manufactured by Sanyo Chemical Industry, polypropylene oxide diol) FA-703: Sannix FA-703 (manufactured by Sanyo Chemical Industry, chipped polyether) Triol) EA-2000: polyethylene adipate (molecular weight 20)
00) DETDA: 3,5 diethyl-2,4-diaminotoluene and 3,5-diethyl-2,6-diaminotoluene 8: 2 mixture EG: diethylene glycol catalyst A: 2-ethyl-potassium hexanoate and 1, 3,5-Tris (3-dimethylaminopropyl)-
Mixture of hexahydro-S-triazine in a weight ratio of 1: 1 Catalyst B: 1,3,5-tris (3-dimethylaminopropyl) -hexahydro-S-triazine Catalyst C: potassium 2-ethylhexanoate

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

[Table 6]

[Brief description of drawings]

FIG. 1 is an external view of a product.

FIG. 2 is a side view of the product.

FIG. 3 is a sectional view of a product.

Claims (2)

[Claims] 1. A thermosetting urethane resin composition comprising (A) an NCO group-terminated prepolymer, (B) a compound containing an active hydrogen group as a curing agent, and a catalyst, wherein the (A)
The NCO group-terminated prepolymer serves as a modifier and has a one-end diol polysiloxane represented by the following general formula (1), or
The one-terminal diol polysiloxane and a molecular weight of 62 to 120
00, a mixture of active hydrogen compounds of (A) NCO
Equivalent ratio of group-terminated prepolymer and curing agent (B) (A) /
(B) is 1.20 to 5.00, a thermosetting urethane resin composition. [Chemical 1] (1) (wherein Me represents a methyl group, n is an integer of 1 ≦ n ≦ 100, and X and Y are 1 ≦ X ≦ 3, 0 ≦ Y ≦ 2 and X
+ Y = 3 is an integer, and R represents an alkylene group which may be linked by one or two or more alkyleneoxy groups. ) 2. A method for producing a molded article, which comprises using the composition according to claim 1 and, if necessary, adding an additive and pouring the composition into a mold using a reaction injection molding machine.