JP3066175B2 - Two-component polyurethane adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is useful for bonding two-component polyurethane adhesives, more specifically, for example, for bonding an aluminum alloy plate to a decorative skin material such as polyvinyl chloride or a stainless steel sheet (film or foil, hereinafter the same). In particular, the present invention relates to a two-component polyurethane adhesive having excellent initial adhesiveness.

[0002]

2. Description of the Related Art Conventionally, as an architectural member based on an aluminum alloy plate (aluminum sash), an aluminum alloy plate coated with a clear paint such as acrylic melamine to improve durability has been used. In order to impart a higher grade, wood-grained polyvinyl chloride (P
(VC) A sheet obtained by bonding a decorative skin material such as a sheet is used. By the way, the adhesion of the painted aluminum alloy plate and the PVC sheet is important for adhesion to the painted surface of the painted aluminum alloy plate. For example, a thermoplastic polyester urethane rubber is used as a main component and a polyisocyanate compound is used as a curing agent. The combined two-component polyurethane adhesive is used, but there is a problem in the adhesiveness immediately after bonding (initial adhesiveness).

[0003]

Means for Solving the Problems Accordingly, the present inventors have:
As a result of intensive research to solve the problem of the initial adhesiveness, a thermoplastic polyester urethane rubber has a copolymer containing an alkoxysilyl compound having an unsaturated bond as a dialkylaminoalkyl methacrylate and another copolymerizable monomer as an essential monomer. If a copolymer obtained by adding a quaternizing alkylating agent for the nitrogen atom of the copolymer to the adhesive is blended as an adhesive, the intended initial adhesion can be greatly improved by compatibilization and improvement of adhesion. As a result, the present invention has been completed.

That is, the present invention relates to a copolymer of an alkoxysilyl compound having an unsaturated bond as an adhesive, a dialkylaminoalkyl methacrylate and another copolymerizable monomer, and a nitrogen atom of the copolymer. An object of the present invention is to provide a two-component polyurethane adhesive comprising a main agent containing a quaternized alkylating agent and a curing agent comprising a polyisocyanate compound.

[0005] The thermoplastic polyester urethane rubber used in the present invention includes dibasic acids (terephthalic acid, isophthalic acid, phthalic acid, succinic acid, adipic acid, azelaic acid,
Sebacic acid) and dihydric alcohols (ethylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol,
(Polyethylene glycol, propylene glycol, etc.)
To a saturated polyester resin having a terminal hydroxyl group obtained by reacting the active hydrogen group with an isocyanate group of a diisocyanate compound (toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, cyclohexylmethane diisocyanate, etc.). It is a linear polymer that has been reacted in approximately equivalent amounts. In particular, a saturated polyester containing a terminal hydroxyl group having a molecular weight of 500 to 2,000 obtained by using isophthalic acid as a dibasic acid and a dibasic acid having 4 to 10 carbon atoms and using a dihydric alcohol having 4 to 10 carbon atoms as a dihydric alcohol A thermoplastic polyester urethane rubber obtained by reacting toluene diisocyanate with a resin is preferable.

[0006] The adhesive used in the present invention is an alkoxysilyl compound having an unsaturated bond, a dialkylaminoalkyl methacrylate and another copolymerizable monomer in a suitable reaction solvent (for example, an ester system such as ethyl acetate and butyl acetate, Polymerization initiators (eg, azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-) in aromatic systems such as toluene, xylene, and benzene, and ketone systems such as methyl ethyl ketone, cyclohexanone, and acetone.
Dimethyl valeronitrile), azobis (cyclohexanecarbonitrile), benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide,
A copolymer obtained by adding a quaternized alkylating agent after or during the polymerization at 60 to 100 ° C. for 2 to 24 hours in the presence of a peracid such as potassium persulfate or ammonium persulfate) By quaternizing the nitrogen atom of

The above-mentioned alkoxysilyl compound having an unsaturated bond (hereinafter referred to as an unsaturated silyl compound) includes, for example, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-acryloxypropyltrimethoxysilane. Methoxysilane, γ
-Acryloxypropylmethyldimethoxysilane, 2-
Γ-methacryloxyalkylalkoxysilanes such as styrylethyltrimethoxysilane or γ-acryloxyalkylalkoxysilanes, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinylmethyldiacetoxysilane, vinyldimethylethoxysilane , Vinylmethyldiethoxysilane, allyltriethoxysilane, vinyltris (β-
Examples thereof include vinylalkoxysilanes such as methoxyethoxy) silane and allylalkoxysilanes, and one or a mixture of two or more thereof is used.

The dialkylaminoalkyl methacrylate includes, for example, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, di-t
-Butylaminoethyl methacrylate and the like.

Examples of the other copolymerizable monomers include acrylic acid, acrylic acid esters (methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, 2-ethoxyethyl acrylate, Glycidyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 1,4
-Butanediol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, etc.), methacrylic acid, methacrylic acid ester
(Methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, t-methacrylate
-Butyl, 2-ethylhexyl methacrylate, octyl methacrylate, isodecyl methacrylate, lauryl methacrylate, lauryl methacrylate-tridecyl, tridecyl methacrylate, cetyl methacrylate-stearyl,
(Stearyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, diethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, etc.) , Acrylic amide,
Acrylonitrile, acrolein, vinyl acetate, styrene, N-methylolacrylamide, vinylpyridine, maleic anhydride, vinylpyrrolidone, butadiene, and the like are used, and one or a mixture of two or more of these are used.

The copolymerization ratio of the unsaturated silyl compound, dialkylaminoalkyl methacrylate and other copolymerizable monomer is usually 0.05 to 0.3 mol: 0.02 to 0.02 mol.
0.5 mol: 1 mol may be selected. When the amount of the unsaturated silyl compound is less than 0.05 mol, the function as an adhesive cannot be sufficiently obtained, and when the amount is 0.3 mol or more, it is not economical. When the dialkylaminoalkyl methacrylate is less than 0.02 mol, the compatibility between the thermoplastic polyester urethane rubber and the adhesive becomes poor, and 0.5
If the molar ratio is exceeded, the water resistance of the adhesive tends to decrease.

The quaternizing alkylating agent includes, for example, chlorides or bromides, chlorides or bromides of various alkyls (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, octyl, nonyl, decyl, undecyl, dodecyl, etc.). Cyclohexyl bromide, benzyl chloride or bromide, allyl chloride or bromide, dimethyl sulfate, methyl or ethyl ester of o- or p-toluenesulfonic acid, ethyl chlorohydrin, ethylene bromhydrin, epichlorohydrin, and the like,
One or a mixture of two or more of these is used. Particularly, benzyl chloride is desirable. The amount used is usually 1.05 to 1 mol of dialkylaminoalkyl methacrylate.
It may be selected at a ratio of 1.5 mol. By quaternizing the nitrogen atom of the copolymer in this way, the compatibility with the thermoplastic polyester urethane rubber is improved, and the adhesiveness and storage stability are also improved.

The amount of the adhesive used (in terms of solid content) is usually selected in the range of 2 to 10 parts based on 100 parts (parts by weight, hereinafter the same) of the above-mentioned thermoplastic polyester urethane rubber. . If it is less than 2 parts, the desired adhesive strength will not be exhibited, and if it exceeds 10 parts, the adhesion to the PVC sheet will be impaired or the initial adhesion will tend to be reduced.

Examples of the polyisocyanate compound used as a curing agent in the present invention include triphenylmethane triisocyanate (Desmodur R, 2 manufactured by Bayer).
0% methylene chloride solution), triisocyanate phenyl thiophosphate (Desmodur RF, 20 from Bayer)
% Methylene chloride solution), isocyanate compound obtained by adding trimethylolpropane to tolylene diisocyanate
(Coronate L, 75% ethyl acetate solution manufactured by Nippon Polyurethanes Co., Ltd.), special grade MDI (Millionate MR manufactured by Nippon Polyurethanes Co., Ltd.) and the like, and one or a mixture of two or more thereof are used. The amount to be used (in terms of solid content) may be usually selected in the range of 5 to 25 parts with respect to 100 parts of the solid content of the thermoplastic polyester urethane rubber.

The two-component polyurethane adhesive according to the present invention comprises a main component consisting of the above-mentioned predetermined ratio of thermoplastic polyester urethane rubber, an adhesive, and a curing agent. .

[0015]

According to the adhesive of the present invention having the above-mentioned structure, excellent initial adhesive strength can be exhibited, especially in the case of bonding a painted aluminum alloy plate and a PVC sheet. It can be used for bonding materials, plastic materials, wood, and the like, lamination lamination processing, and the like.

[0016]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Example 1 (1) Production of thermoplastic polyester urethane rubber: isophthalic acid (4 mol) and adipic acid (4 mol), neopentyl glycol (5 mol) and 1,4-butanediol
(4 moles) to obtain a saturated polyester resin having a hydroxyl value of 55.8 and a molecular weight of 2,000. Next, 35.3 g of toluene diisocyanate was added to 598 g of the saturated polyester resin in ethyl acetate, and the mixture was reacted in the presence of dibutyltin dilaurate to obtain a viscosity of 4000 cps.
/ 20 ° C. to obtain a thermoplastic polyester urethane rubber solution (solid content: 45%).

(2) Production of adhesive: γ-methacryloxypropyltrimethoxysilane (KB, manufactured by Shin-Etsu Chemical Co., Ltd.)
M-503) 75 g, dimethylaminoethyl methacrylate 25 g and methyl methacrylate 325 g were polymerized in toluene 360 g and ethyl acetate 85 g in the presence of AIBN at 78 ° C. for 4 hours to obtain a copolymer. .8 g and 105 g of ethyl acetate were added,
Perform quaternization at room temperature for 1 hour, viscosity 4000 cps
/ 20 ° C. to obtain an adhesive solution (solid content 45%).

(3) Preparation of two-pack polyurethane adhesive The thermoplastic polyester urethane rubber solution 95 of the above (1)
5 parts of the adhesive agent solution of (2) above was blended into the main part, and 5 parts of Millionate MR (manufactured by Nippon Polyurethane Co., Ltd.) were combined with this as a curing agent.

Example 2 and Comparative Examples 1 and 2 In Example 1 / (1), a saturated polyester having a hydroxyl value and a molecular weight shown in Table 1 was prepared by using a dibasic acid and a dihydric alcohol in the number of moles shown in Table 1 below. After the resin is obtained, toluene diisocyanate is reacted under the same conditions to obtain a thermoplastic polyester urethane rubber solution. Next, in the same manner as in Example 1, a two-component polyurethane adhesive is prepared by combining a main agent obtained by mixing the adhesive solution with the thermoplastic polyester urethane rubber solution and a curing agent.

[0020]

TABLE 1 Example Comparative Example 2 1 2 diacid adipic acid - 8 4 sebacic acid 5 - - isophthalic acid 3 - 4 dihydric alcohols neopentylglycol 7 5 - 1,4 - 4 5 ethylene glycol 2 - 4 hydroxyl value 39 56 37.3 molecular weight 2800 2000 3000

Comparative Example 3 A two-part polyurethane adhesive was obtained in the same manner as in Example 1, except that the adhesive solution in the main component was omitted.

Adhesion performance test The two-part polyurethane adhesive obtained in each Example or Comparative Example was applied to a PVC sheet with a thickness of 70 μm using a knife coater.
(Solid film thickness of about 30μ) and dried in a drying oven at 60 ° C for 20 minutes.
It was dried with warm air for 2 seconds. At this time, the amount of the residual solvent determined from the loss on drying was less than 5%. Then, it was immediately pasted on the painted surface of the painted aluminum plate and pressed with a rubber roller.
The test specimens prepared in this way were tested on the following test items (i) and (ii)
And the results are shown in Table 2 below. (i) Initial adhesive strength 180 ° peel strength (kg / 25mm,
A tensile speed of 50 mm / min, the same applies hereinafter) was measured. In addition,
1.0kg / 25mm or more shall be accepted. (ii) Normal adhesive strength After the test specimen was cured at 20 ° C for 3 days, the 180 ° peel strength was measured. In addition, 3.0kg / 25mm or more shall be accepted.

Example 2 Comparative Example 1 2 1 2 3 Initial adhesive strength (kg / 25 mm) 1.5 1.8 0.2 0.1 1.2 Normal adhesive strength (kg / 25 mm) 4.2 4. 5 2.0 1.7 1.4

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-173177 (JP, A) JP-A-61-115939 (JP, A) JP-A-61-215681 (JP, A) JP-A-62 20578 (JP, A) JP-A-62-161527 (JP, A) JP-A-1-268777 (JP, A) JP-A-3-205473 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) C09J 175/06 C09J 143/04

Claims (2)

(57) [Claims] 1. A thermoplastic polyester urethane rubber,
A main component comprising a copolymer of an alkoxysilyl compound having an unsaturated bond, a dialkylaminoalkyl methacrylate and another copolymerizable monomer as an adhesive, and a quaternizing alkylating agent for a nitrogen atom of the copolymer, and a polyisocyanate compound A two-component polyurethane adhesive comprising a curing agent comprising: 2. A thermoplastic polyester urethane rubber,
A reaction of a diisocyanate compound with a terminal hydroxyl group-containing saturated polyester resin having a molecular weight of 500 to 2,000 obtained by a condensation reaction between isophthalic acid and a dibasic acid having 4 to 10 carbon atoms and a dihydric alcohol having 4 to 10 carbon atoms. The two-component polyurethane adhesive according to claim 1, which is: