JPS5936666B2 - Tomakkei Seihouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solvent-based coating composition that provides a high-performance coating film with excellent appearance, physical performance, gasoline resistance, water resistance, weather resistance, etc. by curing at room temperature or low temperature. It is.

In recent years, there has been a demand for paints that are easy to apply, non-polluting, and low-cost due to problems such as pollution and resource conservation, as well as from the perspective of labor saving.

Even in paints for fields that cannot be treated at high temperatures, such as plastics, building materials such as wood and concrete, and metal materials such as automobile refinishing, we use high-solid, non-toxic, and low-solvent paints that use less solvent. There is a demand for something that is inexpensive, easy to paint, and does not require a lot of manpower.

Currently, in these fields, there are air-drying types that do not involve cross-linking reactions in the coating film, such as acrylic paints or melamine paints (so-called high-solid paints) that have added nitrified cotton, and so-called phthalic acid enamels, urethane paints, etc. A cross-linked type is used. In addition to the essential problem that the air-drying type is unsuitable when high performance is required, it is also necessary to increase the degree of polymerization of the resin component in the paint, making it difficult to form an isolide type and making it difficult to coat. The disadvantage is that it requires a lot of manpower. Phthalate enamel is excellent in that it is easy to paint, but there are problems with the film performance such as hardness, while urethane paint has excellent film performance and is quite easy to paint, but it is harmful due to isocyanate and... There are problems such as handling and price. Therefore, the inventors of the present invention believed that it would be difficult to satisfy all of these requirements with an air-drying method, and conducted extensive research into a new cross-linking method that was high-performance, non-toxic, easy to handle, and labor-saving. He invented a method for forming a coating film. In other words, the present invention provides a solvent-based coating composition that provides a coating film with high performance, high hardness, and good water resistance through room temperature curing or low-temperature heating curing, and is low-pollution, resource-saving, and labor-saving. be. The present invention consists of (1) 0.2 to 30% by weight of a basic nitrogen-containing acrylic monomer (2) acrylic acid or methacrylic acid and aliphatic 1
Esters or mixtures thereof with alcohols 50~
80% by weight (3) Acrylic copolymer consisting of 0 to 60% by weight of at least one monomer selected from carboxyl group-containing acrylic monomers, aromatic vinyl monomers, vinyl acetate, and acrylonitrile. (1), 3 per molecule
Basic nitrogen atom (gram atom) in the acrylic copolymer () / Oxygen atom (gram atom) of the epoxy group in the epoxy compound or resin ([I)] It is a solvent-based coating composition blended at a blending ratio of -0.5 to 3.

Component (1) of the acrylic copolymer (1) includes dimethylaminoethyl acrylate or methacrylate, diethylaminoethyl acrylate or methacrylate,
Acrylic acid and/or methacrylic acid derivatives such as t-butyl acrylate or methacrylate are preferably used, but other acrylamide or methacrylamide derivatives such as N-dimethylaminoethyl acrylamide or methacrylamide, N-diethylaminoethyl acrylamide or methacrylamide, etc. Can be used.

The amount of these used is 0.2 to 30% by weight, but 0.5
A range of 15% by weight is preferred for performance and cost reasons. As component (2) of the acrylic copolymer (1), esters of acrylic acid and methacrylic acid with monovalent acyclic or cyclic aliphatic monohydric alcohols are suitable, particularly methanol, ethanol, propanol, butanol. ,
Esters such as lauryl alcohol, stearyl alcohol, etc., and mixtures thereof are preferred, and 50-80% by weight of the polymeric monomers are used.

Component (3) of the acrylic copolymer () includes carboxyl group-containing acrylic monomers such as acrylic acid and methacrylic acid, aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyltoluene, and acrylonitrile. , vinyl acetate, etc. are used.

The carboxyl group-containing acrylic monomer is a copolymer (1)
Although it is preferable to use a small amount for the purpose of improving pigment affinity, etc., it is not particularly necessary in the case of clear paint. The amount used is preferably 3% by weight or less. Styrene, acrylonitrile,. Vinyl acetate etc. are components (2) of copolymer (1).
) are used in appropriate combinations depending on the type or amount used. The amount used is preferably 45% or less. The acrylic copolymer (1) can be polymerized by any polymerization method, but solution radical polymerization is preferably used.

That is, in the presence of an aromatic solvent such as toluene, an alcohol solvent such as isobutanol, and/or an ester solvent such as ethyl acetate, a polymerization initiator such as an azobis-based and/or peroxide-based initiator is added. It is preferably polymerized by a conventional method. It is also possible to use chain transfer agents such as mercaptans for the purpose of controlling the degree of polymerization. As mentioned above, the acrylic copolymer (1) is preferably one in which component (1), component (2), and component (3) consisting of components (1), (2), and (3) are copolymerized. For example, component (1) and component (3
), as well as component (2) and component (3)
As with some copolymers, component (1), component (2), and component (3) may be polymerized separately into two or more types, and these may be mixed. ~ 1 molecule As the compound or resin (n) having three or more epoxy groups per epoxy group, glycidyl ether of polyhydric alcohol is preferably used.

That is, diglycerol polyglycidyl ether, sorbinol polyglycidyl ether, etc. are preferably used. Also preferably used is an acrylic resin copolymerized with glycidyl acrylate or methacrylate and having three or more epoxy groups per molecule. Acrylic copolymer (1) and epoxy compound or Jugetsuho
The blending ratio is set to be basic nitrogen atom (gram atom) in the acrylic copolymer 1)/oxygen atom (gram atom) of the epoxy group in the epoxy compound or resin rule = 0.5 to 3. As for the blending method, it is desirable to mix the acrylic copolymer (4) and the epoxy compound or resin (1!) immediately before applying it to the object to be coated.

That is, to a composition containing the acrylic copolymer (1) to which pigments, additives, solvents, etc. are added if necessary, a composition containing an epoxy compound or resin (I[) to which solvents etc. are added if necessary. Stir and do not leave it for a long time.
If necessary, it is preferable to add a solvent and other additives before applying the composition to the object to be coated. The applied coating film is left at room temperature or, if necessary, heated to a relatively low temperature to dry and form a cured coating film through a crosslinking reaction. ，
The first feature of the present invention is that a compound or resin having three or more epoxy groups per molecule is employed as a crosslinking agent in the crosslinking reaction of a specific acrylic resin coating.

The second feature of the present invention is the first feature, which is that they are combined at a specific blending ratio. These features lead to the great effects described below. The first effect of the present invention is to provide a high-performance paint that saves resources, has low toxicity, is easy to handle, and has good coating workability.

When the solvent-borne coating composition of the present invention is used, a hard and tough coating film is formed by crosslinking.

Compared to the air-drying type, it can be said that the coating film is far superior in various properties such as weather resistance, gasoline resistance, water resistance, and physical performance. If the solvent-based coating composition of the present invention is used, the coating film can be crosslinked, so there is great flexibility in the composition of the acrylic resin as the main resin and the degree of polymerization. From these points of view, it is easy to use a high-solids type, which is a resource-saving direction.
Moreover, it is possible to produce a paint that has excellent painting workability and can form an excellent appearance. Furthermore, when comparing the paint according to the present invention with a cross-linked urethane paint that uses isocyanates, paints that use isocyanates have concerns about the toxicity of isocyanates due to the excessive reactivity of isocyanates, restrictions on the number of solvents that can be used, and dilution stability. There is almost no need to worry about such concerns in the case of the paint of the present invention, which is easy to use, has excellent stability, and has very little toxicity.

The second effect of the present invention is that a high-performance coating film can be obtained at a low cost. In the case of urethane paints that have excellent performance and paint workability and are similar to the present invention in this respect, it is necessary to use large amounts of expensive isocyanates in order to obtain a high-performance coating film in a paint state with good paint workability. . In comparison, the epoxy compound or resin in the present invention is considered to be cheaper than isocyanates, and can achieve the purpose with a small amount of use.

The present invention can be particularly preferably used to form coating films in fields that cannot be treated at high temperatures, such as building materials such as plastics, wood, and concrete, and metal materials for automobile repair applications. In addition, it can also be used to form coating films in fields that can be processed at high temperatures. Examples are shown below to clarify the effects of the present invention.

Example 1 80 parts of toluene, 20 parts of isobutanol, 12 parts of dimethylaminoethyl methacrylate, 58 parts of methyl methacrylate, 30 parts of butyl acrylate, 1 part of n-dodecyl mercaptan in a flask equipped with a condenser, a thermometer, and a stirrer. 1 part of azohisisobutyronitrile and 2 parts of azohisisobutyronitrile at 80°C.
After stirring for a period of time, 0.2 part of azohisisobutyronitrile was added every 2 hours, and the polymerization was completed in 12 hours to obtain an acrylic copolymer (I).

Of this, 100 parts were added to diglycerol polyglycidyl ether (Denacol EX-42 manufactured by Nagase Sangyo Co., Ltd.).
6 parts of 1) were added, stirred, diluted with commercially available lacquer and thinner, and spray-painted on a tin plate to form a coating film of about 35 μm. After being left at 23° C. for 3 days, the pencil hardness was measured to be H, and the appearance was good.

Water resistance (immersion in 50° C. hot water for 10 days) was also good. On the other hand, the result was B when diglycerol polyglycidyl ether was not blended. Example 2 Same as Example 1, 80 parts of toluene, 20 parts of isobutanol
1 part, 6 parts of dimethylaminoethyl methacrylate, 44 parts of methyl methacrylate, 20 parts of styrene, 30 parts of butyl acrylate, and 1 part of azobisisobutyronitrile.
The mixture was stirred at 0° C. for 2 hours, and then 0.3 part of azobisisobutyronitrile was added 5 times every 2 hours, and the polymerization was completed in 16 hours to obtain an acrylic copolymer (I).

To 12 parts of the mixture, 20 parts of toluene, 40 parts of titanium oxide (Tipaque R-550, manufactured by Ishihara Sangyo Co., Ltd.) and sand grinder beads were added and shaken to disperse the pigment. To this, 108 parts of acrylic copolymer (I) and 3.8 parts of diglycerol polyglycidyl ether (Denacol EX-421 manufactured by Nagase Sangyo Co., Ltd.) were blended, diluted with commercially available lacquer thinner, and made into a tin plate. The results of painting and evaluation were as follows. Example 3 In the same manner as in Example 1, 100 parts of toluene, 70 parts of glycidyl methacrylate, 30 parts of butyl methacrylate, and 2 parts of azobisisobutyronitrile were charged, stirred at 80°C for 2 hours, and then mixed with azobis 5 times every 2 hours. 0.2 part of isobutyronitrile was added, and polymerization was completed in 16 hours to obtain an acrylic tree m.

Add 5 parts of the acrylic copolymer (Nl) obtained in Example 2 to 100 parts of the acrylic copolymer (1) obtained in Example 1, stir, dilute with commercially available Lutzker thinner, and prepare in the same manner as in Example 1. The test was conducted.

The pencil hardness was H, and the resistance to external radiation (sterilizing lamp 20 W, irradiation for 4 days) and water resistance (immersion in 50° C. hot water for 10 days) were also good. Comparative Example The same test as in Example 1 was conducted by adding 6 parts of ethylene glycol diglycidyl ether to 100 parts of the acrylic copolymer (1) obtained in Example 1 and stirring.

Claims (1)

[Claims] 1 (1) Basic nitrogen-containing acrylic monomer 0.2-3
0% by weight (2) Ester of acrylic acid or methacrylic acid and aliphatic monohydric alcohol or mixture thereof 5
0 to 80% by weight (3) At least one monomer selected from carboxyl group-containing acrylic monomers, aromatic vinyl monomers, vinyl acetate, and acrylonitrile 0 to 60% by weight
% by weight of an acrylic copolymer (I), a compound or resin having 3 or more epoxy groups per molecule (
II), basic nitrogen atom (gram atom) in acrylic copolymer (I)/oxygen atom (gram atom) of epoxy group in epoxy compound or resin (II) = 0.5 to 3
A solvent-based coating composition formulated at a blending ratio of