JPH07216291A - Coating composition for reparative application - Google Patents

Abstract

PURPOSE:To obtain a coating composition capable of applying reparatively on old coating films without damaging them, excellent in solvent resistance of the coating film thereof, thus also usefully applicable to concrete, comprising each specific fluoroolefin copolymer and curing agent at specified proportions. CONSTITUTION:This coating composition comprises (A) 100 pts.wt. of a fluoroolefin copolymer containing >=50wt.% of mineral terpene and >=5wt.% of fluorine, soluble or dispersible in solvent and (B) 1-100 pts.wt. of a curing agent containing >=5wt.% of mineral terpene, soluble or dispersible in solvent. It is preferable that the component A be a fluoroolefin, e.g. a copolymer of tetrafluoroethylene and a vinyl monomer such as vinyl ether, and the component B a polyisocyanate or amino resin, for example, urea.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for a paint which uses a solvent containing a mineral terpene as a solvent.

[0002]

Fluorine-containing resins for paints have high weather resistance,
Withstands long-term use and has excellent protection functions for construction and civil engineering structures,
Maintenance such as cleaning and repainting is significantly reduced, contributing to the improvement of the living environment and preserving new, fresh colors for a long period of time.
Free color design (Japanese Patent Laid-Open No. 62-0228)
62 publication). In a coating composition for a coating material containing a fluorine-containing resin, a mineral terpene-soluble one-liquid type using a mineral terpene as a solvent and containing no curing agent is known (JP-A-63-199770).

[0003]

However, the two-pack type containing a curing agent usually uses a large amount of a strong solvent such as an aromatic compound such as toluene or an ester compound such as butyl acetate. However, when repairing on the old paint film, there was a defect that the old paint film was damaged. Further, the mineral terpene-soluble 1-liquid type has a drawback that the coating film after film formation has no solvent resistance because it is hardened and does not form a three-dimensional network structure.

[0004]

The present invention has been made to solve the above-mentioned drawbacks, and (a) the content of fluorine which is soluble or dispersible in a solvent containing 50% by weight or more of mineral terpene is 5% by weight. % Or more of the fluoroolefin copolymer and (b) 50% by weight or more of a mineral terpene in a solvent soluble or dispersible curing agent (a) 100 parts by weight (b) 1 to 100 parts The present invention is intended to newly provide a coating composition for a paint containing the above item.

The fluoroolefin copolymer having a fluorine content of 5% by weight or more requires fluoroolefin as a fluorine monomer. Examples of such fluoroolefins include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride and the like.

A vinyl monomer is preferably used as the copolymerization monomer. Among vinyl monomers, vinyl ether and vinyl ester are preferable. Examples of the vinyl ether include cyclohexyl vinyl ether, alkyl vinyl ether, hydroxyalkyl vinyl ether, glycidyl vinyl ether, glycidyl aryl ether, vinyl hydroxyalkyl crotonate, hydroxyalkyl aryl ether, β-methyl glycidyl ether, aminopropyl vinyl ether and vinyl trialkoxysilane. .

A part of the alkyl vinyl ether and hydroxy vinyl ether monomers may be carboxylated by reacting them with an acid such as a dibasic acid anhydride. The modification of the vinyl ether moiety with an acid may be performed after forming the copolymer. As the other vinyl ether, tetrafluorovinyl ether or a vinyl ether having a carboxy group, another vinyl group, a hydroxyl group, a glycidyl group or an amino group as a functional group can be used.

As the vinyl ester, Veova-9, -10 and the like can be preferably used in view of price. Vinyl acetate and vinyl pivalate are also used. It may be vinyl crotonate or hydroxyalkyl vinyl crotonate having a functional group. Vinyl benzoate and maleic acid diester are also used. It may be a copolymer using vinyl ether or vinyl ester or one having a carboxyl group in a part of these copolymers.

It is preferable that the copolymer has a crosslinkable functional group such as a hydroxy group, a hydrolyzable silyl group, a carboxy group, an amino group, an epoxy group, an isocyanate group or a glycidyl group. Not as long.

Further, another cross-linking functional group can be introduced into the copolymer obtained by copolymerizing the monomer having the above-mentioned functional group by a polymer reaction. For example, a carboxyl group can be introduced by reacting a copolymer having a hydroxy group with a dibasic acid anhydride such as succinic acid or hexahydrophthalic acid.

The number of the above-mentioned functional groups is converted into the chemical reaction equivalent of potassium hydroxide and is 1 with respect to the resin solid content per 1 g.
What is equivalent to ~ 150 mg / g is preferable as a mineral terpene soluble type, and more preferably 10 to 50 mg / g or less. These are dissolved in a mineral terpene or the polymerization solvent is replaced with the mineral terpene.

The vinyl monomer is not always an essential copolymer component. In that case, a homopolymer of fluoroolefin or a copolymer obtained by combining several kinds of fluoroolefin may be used.

The copolymer may be blended with 1 to 200 parts of acrylic resin, polyester resin, acrylic polyol resin, polyester polyol resin, etc. per 100 parts of the copolymer. The acrylic resin, polyester resin, acrylic polyol resin and polyester polyol resin to be mixed may have a functional group.

As the coating composition of the present invention, Lumiflon 200, Lumiflon 400, Lumiflon 500, Lumiflon 544 and the like (these are products of Asahi Glass Co., Ltd., trade name), Fluoronate (manufactured by Dainippon Ink and Chemicals), Cefral Coat (Central Glass), Take only the resin component of commercially available products such as Zaflon 200, 300 (manufactured by Toagosei), Zeffle GK5100 (manufactured by Daikin Industries), Kiner 500, Kiner SL, Kiner ADS (manufactured by Penwald) and Floren (manufactured by Japan Synthetic Rubber). It is also possible to use the one dissolved or dispersed in the extruded mineral terpene.

Examples of the curing agent of the present composition include those which are soluble or dispersible in mineral terpenes, for example, polyisocyanates or those whose isocyanate groups are blocked with cabrolactam, or amino resins such as melamine, benzoguanamine and urea. To be These curing agents can be used in combination of several kinds.

The curing agent is preferably contained in an amount of 1 to 100 parts by weight based on 100 parts by weight of the fluoroolefin copolymer having a fluorine content of 5% by weight or more. When the amount of the curing agent is less than 1 part by weight, solvent resistance and hardness are insufficient, and when the amount of the curing agent exceeds 50 parts by weight, workability and impact resistance may be deteriorated, so that a more preferable curing agent is preferable. The content is 1 to 50 parts by weight.

As the coating method, any method such as spray coating, dipping method, roll coater and flow coater can be applied.

The composition of the present invention contains a coloring pigment or dye, a silane coupling agent for improving the adhesion of the coating film,
It is also possible to add an ultraviolet absorber or the like.

Examples of the organic solvent that can be used in combination with the mineral terpene include aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, and n-. Examples thereof include alcohol solvents such as butanol and isobutanol.

The content of the mineral terpene in the mixture of the organic solvent and the mineral terpene is 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight.
That is all.

As the color pigment or dye, for example,
Inorganic pigments such as carbon black and titanium oxide having good weather resistance, organic pigments or dyes such as phthalocyanine blue, phthalocyanine green, quinacridone red, indanthrene orange, and isoindolinone yellow are listed.

If desired, a curing accelerator, a light stabilizer, a matting agent and the like may be added to the composition. As the curing accelerator, dibutyltin dilaurate or the like can be used, and when the curing agent is an amino resin, an acidic catalyst such as paratoluenesulfonic acid can be used.

The light stabilizer may, for example, be a hindered amine light stabilizer, and specific examples thereof include MARX LA62 (manufactured by ADEKA ARGUS CHEMICAL, trade name) and MARX LA67 (manufactured by ADEKA ARGUS CHEMICAL, trade name). Tinuvin 292, tinuvin 144, CGL-1
23, TINUVIN 440 (all manufactured by Ciba Geigy) and the like.

Examples of the matting agent include ultrafine synthetic silica. When a matting agent is used,
An elegant semi-gloss or matte finish can be formed.

Further, a surfactant may be added. Since the surfactant controls the surface tension, it is effective for adjusting the surface concentration of a specific component. These surfactants may be any of nonionic, cationic and anionic types, and Rheorex ASE manufactured by Daiichi Kogyo Seiyaku Co., Ltd., a fluorosurfactant Surflon S38.
2, Acrylic Monsanto Modaflow, Kao Leofat series, etc.

Examples of the material of the article to be coated include concrete, natural stone, inorganic substances such as glass, iron, stainless steel,
There are metals such as aluminum, copper, brass and titanium. It is also suitable for coating organic substrates, that is, plastics, rubbers, adhesives, wood, etc. In particular, it is suitable for coating on a coating film that has already been formed. It is also suitable for coating organic-inorganic composite materials such as FRP, resin reinforced concrete, and fiber reinforced concrete.

The articles to be coated include transportation equipment such as automobiles, trains and airplanes, bridge members, civil engineering materials such as steel towers, waterproof materials, industrial materials such as tanks and pipes, building exteriors, doors, window gate members. , Monuments, construction materials such as poles, medians of roads, road rails such as guardrails and soundproof walls, communication equipment, electric and electronic parts.

[0028]

【Example】

(Example 1) As a terpene solvent-soluble fluororesin (a copolymer of chlorotrifluoroethylene / ethyl vinyl ether / hydroxybutyl vinyl ether / cyclohexyl vinyl ether = 50/2/8/40 mol%, hydroxyl value: 40, acid value 1) To 100 parts by weight of the resin,
Hexamethylene diisocyanate trimer (hardener) 35
Parts by weight, Tinuvin 1130 (Ciba-Geigy benzotriazole-based UV absorber) 3 parts by weight, CGL123 (Ciba-Geigy hindered amine light stabilizer) 0.15 parts by weight, titanium oxide (pigment) 42 parts by weight, Aerosil T6
3 parts by weight of 00 (fine silica produced by Nippon Aerosil) and 100 parts by weight of mineral terpene were mixed to obtain a composition (A) for a colored coating. This was applied to iron members after 10 years of phthalic acid resin coating.

Example 2 The composition (A) of Example 1 was applied to a concrete pedestal after 7 years from the coating of vinyl acetate emulsion.

(Example 3) Example 1 except that the fluororesin of Example 1 was replaced with a fluororesin having a hydroxyl value of 30 and an acid value of 25.
A composition similar to the above was coated on an epoxy resin coated on a new iron member.

Comparative Example 1 Coating was carried out in the same manner as in Example 1 except that xylene was used instead of the mineral terpene.

Comparative Example 2 Coating was carried out in the same manner as in Example 1 except that the curing agent was not added in Example 1.

The results of the above Examples and Comparative Examples are shown in Table 1. In the table, the solvent resistance was evaluated as x when the coating film cured by gauze containing xylene for 1 week was rubbed and dissolved 20 times, and as o when not. Weather resistance is 8 hours with a sunshine weather meter and a gloss retention rate of 8 hours.
Those with 0% or more were evaluated as ◯. As for workability, the finished appearance of the coating film was observed after 1 day of coating.

[0034]

[Table 1]

[0035]

INDUSTRIAL APPLICABILITY The present coating composition has the advantage that it has no drawbacks such as damage to the old coating film, especially when repairing it on the old coating film, and that the coated film after coating has excellent solvent resistance.

Claims (5)

[Claims] 1. A fluoroolefin copolymer having a fluorine content of 5% by weight or more, which is soluble or dispersible in a solvent containing (a) 50% by weight or more of a mineral terpene, and (b) 50% by weight or more of a mineral terpene. (B) 1 to 100 parts by weight of a curing agent that is soluble or dispersible in a solvent
A coating composition for a paint, which is contained in a proportion of 100 parts by weight. 2. The composition according to claim 1, wherein the fluoroolefin-based copolymer is a copolymer of a fluoroolefin and a vinyl monomer. 3. The composition according to claim 1, wherein the curing agent is a polyisocyanate or an amino resin. 4. A coated article obtained by coating the composition according to claim 1 on an article. 5. A coated article obtained by recoating the composition according to any one of claims 1 to 3 on a coated article.