JP2003306640A - Curing accelerator for lacquers and quick-drying hybrid lacquer coating and anticorrosive coating using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid lacquer coating which is dried in a remarkably short time to form the durable lacquer coating film having a high quality without causing a health problem and an environmental pollution and without using a special installation such as a lacquer room, to provide a curing accelerator used for the same, and to provide a quick drying hybrid lacquer anticorrosive coating which can form high quality black coating films on steel materials. <P>SOLUTION: This curing accelerator for the lacquers is characterized by comprising an alkyl ortho-silicate having a specific chemical structure and/or its hydrolytic condensation product, and the quick-drying hybrid lacquer coating and the anticorrosive coating use the same, respectively. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a black-dyed steel material,
A pollution-free, quick-drying hybrid lacquer paint suitable for rust prevention, etc.
And a curing accelerator for lacquer used therein.

[0002]

2. Description of the Related Art Natural lacquer is mainly used for industrial painting because it forms an aesthetic and highly durable coating film that expresses sensibilities such as "fluffy,""moist," and "depth." ing. However, its drying is accelerated by high humidity and does not proceed at low humidity. It is a moisture-curing type natural paint, and since the initial drying is slow, it is easy to cause coating defects such as "drip" and "tamari", and excessive Since wrinkles are generated by humidification, it requires skill to manage drying. Furthermore, a complete curing period of 1 week or more is required.

In this drying system, the laccase enzyme contained in natural lacquer liquor is activated in a high humidity environment to oxidize urushiol which is a main component to produce an oligomer, and an autooxidation reaction of urushiol side chain. It cures after passing through, and generally requires a special drying facility called lacquer room (Muro). Therefore, it has been desired to develop a naturally drying lacquer that dries quickly without being affected by humidity.

Although many inventions have been proposed for the purpose of accelerating the drying of natural lacquer liquor, all of them have the effect of accelerating the drying, but the drying rate is still unsatisfactory, and the lacquer room has a high humidity. I needed (Muro). For example, Japanese Patent No. 3001056 discloses a technique of a self-oxidizing reaction-based naturally drying polymer lacquer that performs enzymatic polymerization in a reaction vessel to generate a urushiol oligomer, but it takes 8 hours or more to cure. I need it.

On the other hand, natural lacquer reacts with iron at room temperature to form urushiol iron salt to block the permeation of oxygen to the surface of iron, and therefore anticorrosion of metal parts such as armor, helmets and firearms has long been done. Used for surface treatment of Nanbu Tekki.

At present, there are roughly two types of industrial rust preventive treatment methods for steel materials: a phosphoric acid (zinc) salt treatment method and a chromate treatment method. In all of these methods, a coating of zinc or chromium, which has a greater ionization tendency than iron, is formed on the iron surface, a sacrificial anode is generated, the surface iron is ionized, and it reacts with water and oxygen to cause rust (hydroxide). It is intended to prevent the production of ferric iron).

The chromate treatment method has a feature that it can black-dye steel materials, but since it uses trivalent or hexavalent chromium as a chromate agent, it has a bad effect on the human body and the environment. large. Specifically, hexavalent chromium causes health disorders such as liver failure, blood circulation disorder, skin ulcer, rhinitis and asthma. Therefore, a method of using a coating type non-chromating agent has recently been proposed as a non-chromating technique that does not use a chromate agent, but this method has a problem that coin scratch resistance and durability are poor.

[0008]

The object of the present invention is to use special equipment such as a lacquer room (muro), and
Provided are a hybrid lacquer paint capable of forming a high-quality and highly durable lacquer coating which can be dried in a significantly shorter time than before without causing any health hazard or environmental pollution, and a curing accelerator used for the same. That is. Still another object of the present invention is to provide a quick-drying hybrid lacquer anticorrosive paint capable of forming a high-quality black dye coating on a steel material.

[0009]

Means for Solving the Problems As a result of intensive research, the present inventor has solved the above problems by reacting an organosilicon compound having a specific chemical structure with a phenolic hydroxyl group of lacquer to form an organic-inorganic hybrid. The present invention has been completed and the present invention has been completed.

That is, the present invention provides the following general formula (1):

[Chemical 2] (However, in the formula, R is an alkyl group which may be the same as or different from each other, and n is an integer of 1 or more.)
It is a hardening accelerator for lacquer which is characterized by containing an organosilicon compound represented by.

The present invention is the above-mentioned curing accelerator for lacquer, wherein the organosilicon compound is an orthosilicic acid alkyl ester and / or a hydrolysis condensation product thereof.

The present invention is a quick-drying hybrid lacquer paint characterized by containing lacquer and each of the above curing accelerators.

The present invention is a quick-drying hybrid lacquer rust preventive coating characterized by containing lacquer and each of the above-mentioned curing accelerators.

Further, the present invention provides the quick-drying hybrid, wherein the lacquer is one or a mixture of two or more selected from the group consisting of raw lacquer, urushiol obtained from raw lacquer, laccol or thithiol, and alkenylcatechol. It is lacquer paint or rust preventive paint.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The curing accelerator of the present invention is for modifying the phenolic hydroxyl group of lacquer to prominently accelerate its curing, and has the following general formula (1):

[Chemical 3] (However, in the formula, R is an alkyl group which may be the same as or different from each other, and n is an integer of 1 or more.)
It contains an organosilicon compound represented by Specifically, R is preferably an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group and a butyl group,
Of these, an alkyl group having 1 to 4 carbon atoms is more preferable. As the organosilicon compound, specifically, an orthosilicic acid alkyl ester (n = 1), a hydrolysis condensation product thereof (n = 2 to 10), or a mixture thereof is preferable.
This organosilicon compound may be used alone or in combination of two or more. When mixed and used, hybrid lacquers having different degrees of condensation are obtained, and the water resistance is improved and the drying speed is easily adjusted.

The quick-drying hybrid lacquer paint or anticorrosive paint of the present invention can be easily prepared by simply mixing lacquer and a curing accelerator containing an organosilicon compound. The quick-drying hybrid lacquer paint and rust-preventive paint of the present invention are prepared by adding an organosilicon compound (curing accelerator) to lacquer and mixing or applying (heating) this to the surface of an object to be coated. Reacts with the organosilicon compound in a dealcohol reaction, and when applied (heated) to the surface of steel, iron (on the surface of steel) or hydroxide (generated during degreasing of steel with sodium silicate) 1 Reacts with iron to form an iron salt, which is organic-inorganic hybridized to form a strong coating film. Curing and drying of coating film is 1 at 100-150 ℃
˜2 hours is sufficient, and the curing and drying speed is significantly accelerated as compared with the case where no curing accelerator is used.

The lacquer used in the present invention means a lacquer liquid (raw lacquer) obtained from a lacquer plant, a purified lacquer obtained by subjecting the raw lacquer to "chrome" (heat dehydration) according to the method of JISK 5950, and acetone-soluble raw lacquer. Urushiol, laccol or thithiol obtained by concentrating the components, alkenylcatechol obtained by chemical synthesis, or any 2 thereof.
Examples include a mixture of two or more species. Specific examples of the alkenylcatechol include 3- (8-pentadecenylcatechol), 3- (8,11-pentadecadienylcatechol), 3-pentadecatrienylcatechol, and 4-.
(8-pentadecenylcatechol) and the like (Nagase, Miyakoshi: Coating Engineering, Vol. 32, No. 11,
p22-35 (1997)). In the present invention, lacquer may or may not contain polysaccharides, nitrogen-containing compounds, laccase enzymes, etc. contained in natural lacquer liquor, but those containing laccase enzymes are convenient for use. preferable.

In the quick-drying hybrid lacquer paint and rust preventive paint of the present invention, the amount of the curing accelerator compounded is 100 g of organic matter based on 100 g of the active ingredient of lacquer (100% urushiol, laccol, thithiol or alkenylcatechol). The proportion of the silicon compound is preferably 1 to 30 g.

In the present invention, a solvent can be used to adjust the viscosity of the coating solution. Specific examples of such a solvent include toluene, xylene, limonene,
Examples include pinene, sesquiterpene, gum turpentine, and the like. The hybrid lacquer paint and rust preventive paint of the present invention may contain various pigments and various additives commonly used in synthetic resin paints, in addition to the above-mentioned solvent.

Furthermore, the coating composition and rust-preventive coating composition of the present invention can be coated by a conventional coating method conventionally used. For coating, an airless spray machine, an air spray machine,
Electrostatic coating machine, dipping, roll coater, flow coater,
A knife coater, a brush, etc. can be used.

As a pretreatment of a metal material such as a steel material with the hybrid lacquer paint and the anticorrosive paint of the present invention, the combined use of sandplast treatment of the material, zinc coating, and zinc undercoating further improves the anticorrosion effect. It is preferable because it is possible.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 To 100 g of Chinese lacquer produced in China, 5 g of orthosilicic acid methyl ester was added dropwise with stirring while controlling the liquid temperature so as not to exceed 50 ° C., and the reaction was carried out to obtain a cocondensate. To this, 100 g of toluene was added to prepare a hybrid lacquer coating solution. The coating solution was spray-coated on a degreased iron bolt, allowed to stand at room temperature for about 5 minutes, heated at 130 ° C. for about 1 hour, and then cured and dried to form a coating film having a dry film thickness of about 20 μm. The appearance of the dried coating film was visually observed, and the pencil hardness, adhesion, scratch resistance, boiling water resistance, solvent resistance and salt water resistance were measured. The results are summarized in Table 1.

[Test Method] (1) Pencil Hardness, Adhesion, Scratch Resistance JIS K540
It measured according to the method of 0. The adhesion was determined by the cross-cut tape method, and the scratch resistance was determined by rubbing the coating film by the coin scratch method and visually checking for scratches. (2) Boiling resistance The test piece was immersed in boiling water to a depth of 60 mm, allowed to stand for 15 minutes and then taken out, and the appearance of the coating film was visually evaluated. Evaluation criteria: ◯: No change in appearance ×: Change in appearance (3) Solvent resistance After rubbing the coating film surface 30 times with absorbent cotton soaked in acetone, the appearance was visually evaluated (rubbing test). Evaluation criteria: ◯: No change in appearance ×: Change in appearance such as whitening or scratches (4) Salt water resistance The salt water spray test method of JIS K5400 was used.
A cross-shaped cut (cross cut) reaching the steel surface was made on the coated surface, and the blister width of the coating film from the cross cut after 72 hours was measured. Evaluation criteria: ◯: Maximum blister width of coating film is less than 3 mm ×: Maximum blister width of coating film is 3 mm or more

Example 2 100 g of urushiol separated from lacquer produced in China according to the method of JIS K 5950 was stirred while controlling and stirring the liquid temperature so as not to exceed 50 ° C., and n = approximately in the general formula (1). 10 g of a hydrolysis condensation product of orthosilicic acid methyl ester of 3.5 and 5 g of water were added dropwise to carry out a reaction to obtain a cocondensate. Limonene 100 g was added thereto to prepare a hybrid lacquer coating solution. This coating solution was spray-coated on the outer surface of a degreased iron can, left at room temperature for about 5 minutes, and then heated at 130 ° C. for about 1 hour to cure and dry. The appearance of the dried coating film was visually observed, and the pencil hardness, adhesion, scratch resistance, boiling water resistance, solvent resistance and salt water resistance were measured. The results are summarized in Table 1.

Example 3 Lacquer produced in China was treated with "chrome" according to the method of JIS K 5950 (including laccase enzyme), and purified lacquer 100 was obtained.
A hybrid lacquer coating solution was prepared in the same manner as in Example 1 except that 10 g of orthosilicic acid methyl ester and 5 g of water were added dropwise to g and reacted. The degreased iron screw was dipped into the coating solution, taken out, and then heated at 130 ° C. for about 1 hour to be cured and dried. The appearance of this dried coating film was visually observed, and the pencil hardness, adhesion, scratch resistance, boiling resistance, solvent resistance and salt water resistance were measured. The results are summarized in Table 1.

Example 4 100 g of 3-alkenylcatechol obtained by the cross-coupling reaction of catechol and flaxseed oil was added to 10 g of the hydrolysis condensation product of orthosilicic acid methyl ester of n = about 3.5 in the general formula (1) and water. A hybrid lacquer coating solution was prepared in the same manner as in Example 1 except that 5 g was dropped and reacted. After spray-coating this coating solution on the outer surface of a degreased iron can, leave it for about 5 minutes at room temperature,
It was heated at 130 ° C. for about 1 hour to be cured and dried. The appearance of the dried coating film was visually observed, and the pencil hardness, adhesion, scratch resistance, boiling water resistance, solvent resistance and salt water resistance were measured. The results are summarized in Table 1.

Example 5 10 g of a hydrolytic condensation product of orthosilicic acid methyl ester of n = about 2.5 in the general formula (1) was added to 100 g of lacquer produced in Vietnam while controlling the liquid temperature so as not to exceed 50 ° C. and stirring. A hybrid lacquer coating solution was prepared in the same manner as in Example 1 except that the mixture was dropped and reacted. The coating solution was spray-coated on a degreased iron bolt, left at room temperature for about 5 minutes, and then heated at 130 ° C. for about 1 hour to be cured and dried. The appearance of the dried coating film was visually observed, and the pencil hardness, adhesion, scratch resistance, boiling water resistance, solvent resistance and salt water resistance were measured. The results are summarized in Table 1.

[0028]

[Table 1]

[0029]

As described above, the curing accelerator of the present invention can be hybridized by a simple operation such as stirring with lacquer at room temperature, and the (organic-inorganic) hybrid lacquer of the present invention containing the same can be hybridized. The paint does not require special equipment such as a lacquer room (Muro), and does not cause health problems or environmental pollution. It is a very high quality and durable lacquer (dry) that dries significantly faster than before. It can form a film and can be used especially for rust prevention of metals such as steel and black dyeing. That is, according to the present invention, a relatively low temperature of, for example, 100 to 150 ° C.,
Even under low humidity conditions of 40 to 50% RH (remarkably faster than conventionally known methods), it can be cured and dried within 2 hours to form a wrinkle-free thick film. Quality equal to or higher than that of a coating formed by a static method (pencil hardness, adhesion, scratch resistance, boiling water resistance,
It has solvent resistance and salt water resistance). Therefore, the coating efficiency can be remarkably improved, making it possible to apply industrial coating of lacquer to a wide range of objects such as metals (especially iron-based materials), plastics, concrete, wood, etc. It has a significant meaning that a rust coating can be formed.

Claims (5)

[Claims] 1. The following general formula (1): (However, in the formula, R is an alkyl group which may be the same as or different from each other, and n is an integer of 1 or more.)
A curing accelerator for lacquer, characterized by containing an organosilicon compound represented by. 2. The curing accelerator for lacquer according to claim 1, wherein the organosilicon compound is an alkyl orthosilicate and / or a hydrolysis condensation product thereof. 3. A quick-drying hybrid lacquer paint comprising lacquer and the curing accelerator according to claim 1 or 2. 4. A quick-drying hybrid lacquer anticorrosive paint comprising lacquer and the curing accelerator according to claim 1 or 2. 5. The rapid lacquer according to claim 3, wherein the lacquer is one or a mixture of two or more selected from the group consisting of raw lacquer, urushiol obtained from raw lacquer, laccol or thithiol, and alkenylcatechol. The dry hybrid lacquer paint or the quick-dry hybrid lacquer anticorrosive paint according to claim 4.