JPH07278494A - Primer composition for coating composition with resistance to acid rain - Google Patents

Abstract

PURPOSE:To obtain a primer composition which has sufficient adherence to a coating composition having resistance to acid rain and has excellent initial adhesion to an adherend. CONSTITUTION:This primer composition is a primer for use in the bonding of a coating composition having resistance to acid rain to an adherend with an adhesive. It comprises 100 pts.wt. polyisocyanate and 1-100 (excluding 1 and 100 pts.wt.) acrylic silane or vinylsilane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer composition for an acid rain resistant coating which is excellent in adhesiveness and adhesion development.

[0002]

2. Description of the Related Art Conventional paints for automobiles include acrylic paints and alkyd paints, and polyisocyanate primers are used for adhering adherends to the paints. It was possible to obtain sufficient adhesiveness. Further, as described in JP-A-5-179159, there is a primer containing an alkoxysilane, an organic titanate, and a tin salt of a carboxylic acid as a primer for coating an acrylic coating on a silicone support. However, in the case of adhering an adherend to a plate or molded article coated with an acid rain resistant paint that has been developed in recent years, it has become impossible to maintain sufficient adhesiveness and initial adhesiveness with conventional primers. .

[0003]

SUMMARY OF THE INVENTION Therefore, the present invention provides a primer composition having excellent initial adhesion development for acid rain resistant paint and a plate coated with the acid rain resistant paint using the primer composed of the primer composition. The present invention provides a method for adhering a substrate to an adherend.

[0004]

In order to improve the above-mentioned problems, the present inventors have found that a composition obtained by adding acrylic silane or vinyl silane to polyisocyanate is excellent as a primer composition for acid rain paint. The inventors have found out that, and have reached the present invention.

That is, the present invention is a primer used for adhering an adherend on an acid rain-resistant paint with an adhesive, wherein more than 1 part by weight of acrylic silane or vinyl silane is added to 100 parts by weight of polyisocyanate. Provided is a primer composition for an acid rain resistant coating material, which comprises less than 100 parts by weight. In addition, polyisocyanate 1 on acid rain resistant paint
Acrylic silane or vinyl silane is applied to 100 parts by weight of a primer containing more than 1 part by weight and less than 100 parts by weight of acrylic silane, and an adhesive is further applied to adhere the adherend to the acid-resistant rain paint. A method for adhering a primer composition for rain paint is provided.

The present invention will be described in more detail below.
The acid rain coating primer composition of the present invention contains polyisocyanate and acrylic silane or vinyl silane.

As the polyisocyanate used in the present invention, any aliphatic, alicyclic or aromatic polyisocyanate can be used as long as it is a normal polyisocyanate. In particular,
4,4'-diphenylmethane diisocyanate, 2,
4'-diphenylmethane diisocyanate, Desmodur RFE, Desmodur HL, 1,5-naphthalene diisocyanate (NDI), tolidine diisocyanate (TODI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate (TD)
I), MDI, p-phenylene diisocyanate, aromatic polyisocyanates such as polymethylene polyphenylene polyisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI); alicyclic polyisocyanates such as isophorone diisocyanate; aroma such as xylene diisocyanate Examples thereof include aliphatic polyisocyanates; and carbodiimide-modified or isocyanurate-modified polyisocyanates thereof, which are used alone or in combination of two or more. Specifically, the chemical structure of Desmodur RFE (manufactured by Bayer) is

[0008]

[Chemical 1]

[0009] Desmodur HL (manufactured by Bayer) is a condensate of TDI: HDI = 3: 2. In particular, it is preferable to use a mixture of two or more polyisocyanates from the viewpoint of adhesiveness, and specific examples thereof include 4,4′-diphenylmethane diisocyanate (A), desmodure RFE (B), desdes Module HL (C) is (A) :( B) :( C) = 2: 5: 3
The mixture is used in a molar ratio of 2: 7: 1, especially 2: 6: 2.

As the acrylic silane used in the present invention,
A silane compound having an acryl group or a methacryl group is included, and specifically, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxybutyl. Examples thereof include trimethoxysilane, γ- (meth) acryloxybutyltriethoxysilane, γ- (meth) acryloxyethyltrimethoxysilane, and γ- (meth) acryloxyethyltriethoxysilane. The content of acrylic silane in the primer composition for an acid rain resistant coating composition of the present invention is more than 1 part by weight and less than 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of polyisocyanate. If it is less than 1 part by weight, a sufficient effect cannot be obtained, and 1
If it is more than 00 parts by weight, the adhesive property will be lost.

The vinylsilane used in the present invention includes vinyltriethoxysilane, vinyltrimethoxysilane,
Methyl vinyl dimethoxysilane etc. are mentioned. The content of vinyl silane in the primer composition for acid rain resistant coating of the present invention is 100 parts by weight of polyisocyanate.
It is more than 1 part by weight and less than 100 parts by weight, preferably 5 to 50 parts by weight. If it is less than 1 part by weight, a sufficient effect cannot be obtained, and if it is more than 100 parts by weight, the adhesive property is lost.

In addition to the above, a catalyst, a solvent, a filler, a colorant, a desiccant, a resin and the like may be added to the primer composition for an acid rain resistant paint of the present invention. Examples of the catalyst that can be used in the present invention include dioctyltin dilaurate (DOTL), dibutyltin dilaurate (DBTDL), dibutyltin thiocarboxylate, and the like. The content of the catalyst in the primer composition for an acid rain resistant coating of the present invention is 0.05 to 1 part by weight, preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of polyisocyanate. Are preferable in terms of the balance between curability and storage stability.

Solvents usable in the present invention include ethyl acetate, acetone, ethyl ether, xylene, toluene,
Examples thereof include benzene and methyl ethyl ketone. The content of the solvent in the primer composition for acid rain paint of the present invention is 500 with respect to 100 parts by weight of polyisocyanate.
It is preferably from 1000 to 1000 parts by weight, preferably from 700 to 800 parts by weight, from the viewpoint of working viscosity.

The filler that can be used in the present invention has the function of increasing the viscosity of the primer composition and the hardness after curing as a filler, and the function of suppressing the reaction between isocyanate and water. , Calcium carbonate, carbon black, clay, talc, titanium oxide, quick lime, kaolin, zeolite, synthetic zeolite, siliceous earth, vinyl chloride paste resin, glass balloon, vinylidene chloride resin balloon, etc., used alone or in combination. can do. The use of carbon improves the adhesion of the primer to acid rain resistant paint. The content of the filler in the primer composition for an acid rain resistant coating composition of the present invention is 30 to 300 parts by weight, particularly 50 to 200 parts by weight, based on 100 parts by weight of polyisocyanate, from the viewpoint of adhesiveness. preferable.

The method for producing the primer composition for acid rain paint of the present invention can be obtained by mixing the above polyisocyanate, acrylic silane or vinyl silane, and optionally other additives, and thoroughly kneading. it can.

The primer of the present invention is used in the case of a plate or a molded article coated with a fluorine-based, acrylic-based, melamine-based, especially highly cross-linked acrylic / melamine-based paint having acid rain resistance. Any material such as In particular, it is suitable when the primer of the present invention is applied to a steel plate coated with an acrylic or melamine-based acid rain-resistant paint for automobiles to adhere an adherend via an adhesive.

The adhesive used in the present invention is preferably a urethane adhesive, and any urethane adhesive may be used as long as it is used as a usual moisture-curable urethane adhesive.
Further, such an adhesive may be used as a sealant. As such a urethane adhesive, a composition containing a urethane prepolymer composed of an isocyanate and a polyol and, if necessary, other additives is used.

Examples of the polyol compound which is one of the raw materials for producing the urethane prepolymer include various polyether polyols or polyester polyols generally used for producing urethane compounds, and further polymer polyols.

The polyether polyol is, for example, a product obtained by addition-polymerizing one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran with a compound having two or more active hydrogens. Is. Where 2
Examples of the compound having one or more active hydrogens include polyhydric alcohols, amines, alkanolamines and polyhydric phenols. As the polyhydric alcohols, ethylene glycol, propylene glycol, butanediol, diethylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol, etc., the amines, ethylenediamine, hexamethylenediamine, etc., the alkanolamines , Ethanolamine, propanolamine and the like, and polyhydric phenols include resorcin, bisphenols and the like.

The polyester polyol is a polycondensate of a polyhydric alcohol and a polybasic carboxylic acid, a condensate of a hydroxycarboxylic acid and a polyhydric alcohol, a polymer of a lactone, and the like. Examples of the compounds include the compounds exemplified above in the section of polyether polyol, and examples of the polybasic carboxylic acids include adipic acid, glutaric acid, azelaic acid, fumaric acid, maleic acid, phthalic acid, terephthalic acid, and dimer acid. , Pyromellitic acid and the like. Further, as a condensate of hydroxycarboxylic acid and polyhydric alcohol, castor oil, a reaction product of castor oil and ethylene glycol, a reaction product of castor oil and propylene glycol and the like are also useful.

The lactone polymer refers to a polymer obtained by ring-opening polymerization of propion lactone, caprolactone, valerolactone and the like with an appropriate polymerization initiator.

The polymer polyol is, for example, one obtained by graft-polymerizing an ethylenically unsaturated compound such as acrylonitrile, styrene or methyl (meth) acrylate with the above polyether polyol or polyester polyol, or 1,2- or 1,4. -Polybutadiene polyol, or hydrogenated products thereof.

Examples of the polyol compound as a raw material for producing the polyurethane prepolymer include the above-mentioned ones.
One kind may be used alone, or two or more kinds may be used in combination, but one having a weight average molecular weight of about 100 to 10,000 is preferable, and 500 to
It is more preferably about 5,000.

As the polyisocyanate compound which is the other raw material for producing the polyurethane prepolymer, various polyisocyanate compounds used in the production of ordinary polyurethane resins are exemplified. Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, phenylene diisocyanate, xylene diisocyanate (XD
I), methylene diisocyanate (MDI), diphenylmethane-4,4-diisocyanate, naphthylene-
1,5-diisocyanate, and hydrogenated compounds thereof, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1-methyl-2,4-diisocyanate cyclohexane, 1-methyl-2,6- Diisocyanate cyclohexane, dicyclohexylmethane diisocyanate, triphenylmethane triisocyanate and the like can be mentioned.
These polyisocyanate compounds may be used alone or
You may use 2 or more types together.

The amount ratio of the polyol compound and the polyisocyanate compound during the production of the polyurethane prepolymer is
The amount ratio is such that the number of hydroxyl groups in the polyol compound is 1 or less per 1 isocyanate group in the polyisocyanate compound, but 0.95 to 0.75 is preferable.

The urethane adhesive used in the present invention is usually added to a moisture-curable composition such as a filler, a plasticizer, a colorant, a curing accelerator, a curing retarder, an anti-sagging agent and an antiaging agent. Additives may be added.

Examples of the filler include calcium carbonate, carbon black, clay, talc, titanium oxide, quick lime, kaolin, zeolite, siliceous earth, vinyl chloride paste resin, glass balloon, vinylidene chloride resin balloon and the like, either alone or It can be mixed and used. When a filler is added, urethane prepolymer 10
It is preferably 1 to 150 parts by weight with respect to 0 parts by weight.

Examples of the plasticizer include dioctyl phthalate (DOP), dibutyl phthalate (DBP), dilauryl phthalate (DLP), butylbenzyl phthalate (BBP), dioctyl adipate (DOA), diisodecyl adipate (DIDA), trioctyl. Phosphate (TOP), tris (chloroethyl) phosphate (TCEP), tris (dichloropropyl) phosphate (TDCPP), propylene glycol adipate polyester, butylene glycol adipate polyester, alkyl epoxystearate, epoxidized soybean oil, etc. , And can be used alone or as a mixture. When a plasticizer is added, urethane prepolymer 10
It is preferably 10 to 100 parts by weight with respect to 0 parts by weight in terms of workability.

As the tackifier, various titanate or silane coupling agents, reaction products of coupling agents and isocyanate compounds, reaction products of two or more coupling agents (for example, various aminosilanes and epoxysilanes). Reaction product, a condensation reaction product of two or more molecules of the alkoxy group of the coupling agent), and the like, and these can be used alone or in combination.

Examples of such urethane adhesives include WS-100 manufactured by Yokohama Rubber Co., Ltd.

In the present invention, the adherend adhered onto the acid rain resistant paint via an adhesive is a metal, an inorganic material, a rubber or a resin, and may be a molded body usually used for automobiles. .

Next, a method of adhering an adherend on an acid rain resistant paint using a primer comprising the primer composition for acid rain resistant paint of the present invention will be described. A primer comprising the primer composition for acid rain resistant paint obtained as described above is applied onto the acid rain resistant paint. Then, the primer is applied and then a urethane adhesive is further applied to adhere the adherend. When the adherend is adhered with an adhesive using the primer of the present invention on the acid rain-resistant paint, the initial adhesiveness is very excellent and the adherend does not move for a long time in the manufacturing process of automobiles and the like. Since it is not necessary to wait for the initial adhesiveness to develop, it is industrially very useful.

The method of applying the primer comprising the primer composition for acid rain resistant paint of the present invention onto the acid rain paint coated plate is dipping coating, spray coating,
Conventional coating methods such as knife coating and brush coating can be used. Coating thickness is 5 to 15 μm
Is preferable in terms of adhesion between the adherend and the urethane adhesive and workability. As a method for applying the urethane adhesive to the acid rain paint coating plate which is the adherend, the same method as the method for applying the above-mentioned primer to the adherend may be used. The coating thickness of the urethane adhesive is 5 to 20 mm.

The adhesive between the acid rain-resistant paint plate and the adherend, which is obtained by the bonding method of the present invention, is excellent in the adhesiveness, particularly the initial adhesiveness-developing property.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples, but the scope of the present invention is not limited thereby.

(Examples 1 to 5, Comparative Examples 1 to 3) Table 1 below
The composition components of (1) were mixed and kneaded in a ball mill for 48 hours to obtain a primer composition for acid rain resistant coating. The obtained composition is applied to an automobile acid-resistant rain-coated plate (acrylic / melamine-based paint), which is an adherend, and the primer composition of the present invention is applied so that the application thickness is 10 μm, and the composition is applied at 20 ° C. for 1 hour. After drying, a one-pack type moisture-curable urethane adhesive (WS-100 manufactured by Yokohama Rubber Co., Ltd.) was applied to a thickness of 5 mm to obtain a sample. (Initial Adhesion Test) The above sample was subjected to 65% R at 20 ° C
What was left to stand for 3 days in H (initial) and what was left to stand for 7 days were manually peeled off by putting a blade at the interface. At that time, the state of peeling between the adhesive and the adherend was observed, and hand peeling evaluation was performed. The result was shown by [ratio of cohesive failure of adhesive / ratio of interface failure]. The conditions and results are shown in Table 1.

(Aging condition) The above sample was treated at 20 ° C. for 6 hours.
The samples used for the heat resistance test after adhering the ones left at 5% RH for 3 days (initial) and the ones left for 7 days were used for the water resistance test after 14 days at 90 ° C. The sample was kept in water at 40 ° C. for 14 days and then subjected to the above-mentioned hand peeling evaluation.

[0038]

[Table 1]

Note) Polyisocyanate: 4,4'-diphenylmethane diisocyanate, Desmodur RFE
(Made by Bayer)

[0040]

[Chemical 2]

Desmodur HL (manufactured by Bayer) (TDI: HDI = 3: 2) were mixed at a molar ratio of 2: 6: 2. Solvent: Ethyl acetate Drying agent: Synthetic zeolite Catalyst: Dioctyltin dilaurate (DOTL) Urethane resin: Pandex T manufactured by Dainippon Ink and Chemicals, Inc.
-5205 Acrylic silane: γ-methacryloxypropyltrimethoxysilane Vinylsilane: Vinyltriethoxysilane

[0042]

EFFECTS OF THE INVENTION According to the primer composition of the present invention, the primer composition has sufficient adhesiveness to the acid rain-resistant paint, and when the adherend to which the acid rain-resistant paint is applied and the adherend are adhered to each other, Since it has excellent adhesiveness, the workability in adhering the adherend on the acid rain resistant paint is greatly improved.

Claims (2)

[Claims] 1. A primer used for adhering an adherend to an acid rain-resistant paint with an adhesive, wherein acrylic silane or vinyl silane exceeds 1 part by weight to 100 parts by weight of polyisocyanate.
A primer composition for an acid rain resistant coating, characterized by containing less than 1 part by weight. 2. A primer containing at least 1 part by weight and less than 100 parts by weight of acrylic silane or vinyl silane is applied to 100 parts by weight of polyisocyanate on an acid rain-resistant paint, and an adhesive is further applied. A method for adhering a primer composition for an acid rain resistant paint, which comprises adhering an adherend on the acid rain resistant paint.