JPS6145668B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a primer composition, and more particularly to a transparent primer composition containing a reaction product having a biuret group and having excellent adhesiveness, water resistance, heat resistance, corrosion resistance, etc. Conventionally, silane coupling agents or mixtures of epoxy resins, urethane resins, and chlorinated rubber resins with silane coupling agents have been used as primers for glass, concrete, various metals, and the like. However, these materials were not satisfactory in terms of adhesion and heat resistance, particularly in terms of adhesion at high temperatures and humidity. Organic solvent solutions of silane coupling agents, which are currently mainly used, show good adhesive strength on mirror-like adherends such as glass, or on rough surfaces such as concrete, mortar, slate, and PVC. It has the disadvantage that it does not exhibit good adhesive strength to steel plates and the like. Furthermore, since the silane coupling agent has a weak cohesive strength of the cured film, the film deteriorates when wet or at high temperature or high humidity and does not exhibit sufficient adhesive strength. Furthermore, it has the disadvantage of poor storage stability because it is extremely sensitive to moisture. In order to overcome these drawbacks, epoxy-based silane coupling agents, for example, have been proposed as silane coupling agents with specific compositions, but these are still unsatisfactory, especially in terms of transparency and heat-resistant adhesive properties. It is enough. The inventors of the present invention have improved the film-forming ability and cohesive ability by providing a silane compound or a mixture thereof with an amino compound and a reaction product from an organic polyisocyanate with a biuret bond, thereby increasing adhesive strength and Water resistance, stability, corrosion resistance,
The present inventors have discovered that a primer composition with excellent workability can be obtained, and have completed the present invention. That is, the primer composition of the present invention contains an aminosilane compound and/or a mixture of a silane compound other than the aminosilane compound and an amino compound, and a reaction product having a Biuret group made of an organic polyisocyanate. By containing this Biuret group,
The primer composition of the present invention is particularly superior in transparency, boiling water resistance, adhesive strength, and heat resistant adhesive strength compared to conventional epoxy silane coupling agents that do not have a Biuret group. In producing the primer of the present invention, the organic polyisocyanate in the reactor is heated to 70°C to 75°C, and the silane compound is added in a dry nitrogen atmosphere while stirring for 2 hours and 30 minutes to 3 to 4 hours. and drip. Then the reaction temperature is 110℃ to 160℃
The mixture is heated to 70°C, reacted for 3 to 6 hours, cooled to 70°C, and a solvent is added. In this case, the molar ratio of the organic polyisocyanate and the silane compound is NCO group/NH ₂
= 1.6 to 2.7 is preferred. This ratio
If it is less than 1.5, gelation may occur during the second stage reaction at 110°C to 160°C, and if it is more than 4, it is difficult to obtain transparency. If the dropping temperature is 75°C or higher, side reactions such as polymerization are likely to occur. If the addition is carried out within 2 hours, gelation may occur during the second stage reaction at 110°C to 160°C. This reaction can be carried out in a solvent or without a solvent. In this way, the reaction at 70-75°C in the first stage first produces a urea bond, and then the 110-75°C reaction in the second stage.
Biuret bonding occurs in a reaction at 160°C. As the organic polyisocyanate used in the present invention, any organic polyisocyanate can be used, but examples of aromatic polyisocyanates include diphenylmethane diisocyanate, toluene diisocyanate, xylylene diisocyanate, millionate MTL (Japanese) Examples of aliphatic diisocyanates include hexamethylene diisocyanate and trimethylhexamethyl diisocyanate, and alicyclic diisocyanates include isophorodiisocyanate and Desmodyur N (Bayer Polyisocyanate).
Examples include 4,4'-dicyclomethane diisocyanate. Furthermore, examples of substances having active functional groups include isocyanate group-terminated prepolymers obtained by reacting these isocyanates with alcohols such as propylene glycol and trimethylolpropane, polyester polyols, and polyether polyols. is Coronate L
(manufactured by Nippon Polyurethane) Coronate HL (manufactured by Nippon Polyurethane), etc. are also included. Usually one or more of them are used. Examples of aminosilane compounds used in the present invention include γ-aminopropyltriethoxysilane, aminomethyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, N-(β-aminoethyl)aminomethyltrimethoxysilane, γ -Aminoisobutyltrimethoxysilane, N-(β-aminoethyl)aminopropyltriethoxysilane, N-bis(β-hydroxyethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ- Aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-amino-β-methylpropyltriethoxysilane, and analogs thereof; Examples include N-(α-carboxymethylaminoethyl)-γ-aminopropyltriethoxysilane or a mixture of two or more thereof. Furthermore, the object can also be achieved using a silane compound having a carboxyl group, which is obtained by reacting a silane compound having a vinyl group or an epoxy group with a compound having a carboxyl group in the molecule. Examples of silane compounds having a vinyl group include vinyltriethoxysilane, vinyl-tris(β-
methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, etc. Examples of silane compounds having epoxy groups include γ-glycidoxypropyltriethoxysilane, β-
Examples include (3,4-epoxycyclohexyl)ethyltrimethoxysilane, and examples of compounds having a carboxyl group include acrylic acid, methacrylic acid, adipic acid, and phthalic acid. Examples of silane compounds other than aminosilane compounds used in the present invention include γ-chloropropyltriethoxysilane, vinyltrichlorosilane,
Vinyltriethoxysilane, vinyl-tris (β
-methoxyethoxy)silane, γ-methacrylopropyltrimethoxysilane, β-(3,4-ethoxycyclohexyl)ethyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glyside Xypropylmethyldimethoxysilane, 3,4-
Examples include epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethylmethyldimethoxysilane, γ-mercabutopropyltrimethoxysilane, and one type each of these amine compounds and silane compounds or a mixture of two or more types are used. . Examples of amino compounds include aliphatic amines such as hexylamine and propylamine, aromatic amines, and alicyclic amines. Furthermore, in addition to the above amine compounds, formic acid,
Examples include carboxylic acids such as acetic acid and adipic acid, and water. When the reaction is carried out in a solvent, examples of preferable solvents include xylene, cellosolve acetate, and monochlorobenzene. The primer composition of the present invention can be diluted with an organic solvent and used alone, but may also contain other components, such as zinc powder, iron oxide, aluminum powder, anticorrosion pigments such as zinc chromate, and coloring if necessary. When used in combination with pigments, extender pigments, etc., a primary anticorrosive primer composition for metal anticorrosive paints that has good adhesion, water resistance, and quick drying properties can be obtained. Furthermore, when the primer composition of the present invention diluted with an organic solvent is applied as a sealant to concrete, slate, glassy metal substrates, etc., it provides excellent adhesion retention at the interface between the adherend and the sealant. . Examples of the organic solvent used as a diluent for the primer composition of the present invention include esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic hydrocarbons such as toluene and xylene. It is added in an amount of 5 to 5,500 parts per 100 parts of the primer composition. The present invention will be explained in more detail with reference to the following Examples and Comparative Examples. In the following, % represents weight % unless otherwise specified. Example 1 598 g of diphenylmethane diisocyanate was heated to 70°C with stirring in a four-necked flask to give γ-
202 g of aminopropyltriethoxysilane was added dropwise under a dry nitrogen atmosphere at 70° C. over 3 hours to obtain an intermediate reaction product. Next, this intermediate reaction product is
After raising the temperature to 150℃ and reacting at the same temperature for 5 hours, 70℃
The mixture was cooled to ℃ to obtain a pale yellow transparent viscous substance. 200 g of ethyl acetate was added to obtain a solution of the reaction product. The reaction product solution has an NCO content of 10.1% and a viscosity of
At 2800cps/25℃, no change was observed even after 12 months. Example 2 612 g of toluene diisocyanate and 200 g of cellosolve acetate were heated to 70°C while stirring in a four-necked flask to form N-β (aminoethyl)γ.
187 g of -aminopropyltriethoxysilane was added dropwise at 70°C under a dry nitrogen atmosphere over a period of 3 hours to obtain an intermediate reaction product. Next, this intermediate reaction product is
The temperature was raised to 150°C, and the mixture was reacted at the same temperature for 5 hours, and then cooled to room temperature to obtain a pale yellow and transparent solution of the reaction product. NCO content 17.5%, viscosity 2100cps/25℃
No change was observed even after 12 months. Example 3 10 g solution of reaction product of Example 1, zinc powder
53 g and 316 g of ethyl acetate were mixed to obtain a primary primer composition for metal anticorrosive paint. This was applied to a blast plate by spraying, a chemical resistance test was conducted, and the results were compared with a control sample in the following comparative example. The results are shown in Table 1. Comparative Example 1 598 g of diphenylmethane diisocyanate was heated to 70°C with stirring in a four-necked flask, and γ-
202 g of aminopropyltriethoxysilane was added dropwise at 70° C. over 3 hours under a dry nitrogen atmosphere, the reaction was further carried out at the same temperature for 2 hours, and 200 g of ethyl acetate was added to obtain a solution of the reaction product. A primer composition was prepared using the same recipe as in Example 3. This was used as a comparison sample. Example 4 500 g of diphenylmethane diisocyanate was heated to 70°C with stirring in a four-necked flask, and N
-β(aminoethyl)γ-aminopropyltriethoxysilane 47.5g, γ-mercaptopropyltrimethoxysilane 47.5g and hexylamine 21.5g
A mixed solution was added dropwise over a period of 3 hours to obtain an intermediate reaction product. Next, this intermediate reaction product was heated to 150°C, reacted at the same temperature for 5 hours, and then cooled to 70°C to obtain a pale yellow transparent viscous reaction product. 154 g of ethyl acetate was added to obtain a solution of the reaction product. The NCO content was 13.5%, the viscosity was 3000 cps/25°C, and no changes were observed after 12 months. 10 g of a solution of this reaction product, 53 g of zinc powder, and 316 g of ethyl acetate
were mixed and tested in the same manner as in Example 3. The results are shown in Table 1.

[Table] Example 5 Add 300 g of ethyl acetate to 100 g of the solution of the reaction product of Example 1, apply it to various adherends (2 pieces of each) with a brush, leave it for 10 minutes, and adhere certain parts of the coated surface to each. After being allowed to stand at room temperature for 24 hours, it was used in a comparative test. The test method is UT-M-1 after universal tensile test.
(manufactured by Toyo Sokki Co., Ltd.), the specimen was grasped at both ends and tensile fracture state was examined at a constant speed and constant load. The results are shown in Table 2. Example 6 300 g of ethyl acetate was added to 100 g of the solution of the reaction product of Example 2, and the same tests as in Example 5 were conducted. The results are shown in Table 2. Example 7 600 g of diphenylmethane diisocyanate was heated to 70°C with stirring in a four-necked flask to give γ-
A mixed solution of 75.6 g of mercaptopropyltriethoxysilane and 78 g of hexylamine was added dropwise under a dry nitrogen atmosphere at 70° C. over 3 hours to obtain an intermediate reaction product. Next, this intermediate reaction product was heated to 150°C, reacted at the same temperature for 5 hours, and then cooled to 70°C to obtain a pale yellow transparent viscous liquid. Furthermore, ethyl acetate
188.4g was added to obtain a solution of the reaction product. The above reaction product has an NCO content of 12.5% and a viscosity of
At 2500cps/25℃, no change was observed even after 12 months. 100 g of this reaction product solution was further diluted with 300 g of ethyl acetate and tested in the same manner as in Example 5. The results are shown in Table 2. Comparative Example 2 300 g of ethyl acetate was added to 100 g of the solution of the reaction product of Comparative Example 1, and the same test as in Example 5 was conducted. The results are shown in Table 2.

[Table] Example 8 Add and dissolve 300 g of ethyl acetate to 100 g of the solution of the reaction product of Example 1, apply the solution with a brush to a glass plate, aluminum plate, or tin plate as a test piece, leave it for 10 minutes, and then apply polyurethane. Paint [Nitsuporan
Add 190 g of Coronate L (manufactured by Nippon Polyurethane Kogyo) to 100 g of 800 (manufactured by Nippon Polyurethane Kogyo),
Furthermore, a mixed solvent of cellosolve acetate/butyl acetate/ethyl acetate/toluene = 1:1:1:1
Prepared by adding 300g] and apply with a brush.
After being left at room temperature for 30 minutes, it was cured at 100°C for 1 hour, and then subjected to a hot water immersion test at 80°C. The results are shown in Table 3. Example 9 300 g of ethyl acetate was added to 100 g of the solution of the reaction product of Example 2, and the same tests as in Example 8 were conducted. The results are shown in Table 3. Example 10 300 g of ethyl acetate was added to 100 g of the solution of the reaction product of Example 7, and the same tests as in Example 8 were conducted. The results are shown in Table 3. Comparative Example 3 300 g of ethyl acetate was added to 100 g of the solution of the reaction product of Comparative Example 1, and the same test as in Example 8 was conducted. The results are shown in Table 3.

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Claims (1)

[Claims] 1 A mixture of an amino silane compound and/or a silane compound other than the amino silane compound, an amino compound, and an organic polyisocyanate at 110°C to 160°C.
A primer composition characterized in that it contains a reaction product having a Biuret group obtained by reacting at a temperature of °C.