JPH09183937A - Solution coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a solution coating composition which can give a coating film excellent in weather resistance, etc., and is not problematic in the global environment and adverse effect on the human body by mixing a fluorocopolymer comprising specified amounts of specified monomer units with an aliphatic organic solvent and a curing agent. SOLUTION: This solution coating composition comprises a fluorocopolymer comprising 30-60mol%, based on the total monomer units, fluoroolefin monomer (e.g. chlorotrifluoroethylene), 15-50mol% vinyl carboxylate monomer (e.g. vinyl versatate) units, 1.5-15mol% hydroxyalkvl acrylate (e.g. 4-hydroxybutyl acrylate) units and 1.5-15mol% hydroxyalkyl crotonate monomer and/or hydroxyalkyl vinyl ether monomer (e.g. 2-hydroxyethyl crotonate), an aliphatic organic solvent and a curing agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fluorine-containing solution type coating composition.

[0002]

2. Description of the Related Art Fluorine-containing copolymers are attracting attention as resins for paints because of their excellent chemical resistance and weather resistance.
The use of the copolymer in a solution type coating which is easy to apply has been actively studied. Specifically, for example, a copolymer composed of chlorotrifluoroethylene, cycloalkyl vinyl ether, alkyl vinyl ether and hydroxyalkyl vinyl ether (JP-A-57-34107), or chlorotrifluoroethylene, carboxylic acid vinyl ester and hydroxyl group-containing Copolymers composed of vinyl monomers (JP-A-61-57609 and JP-A-3-57609)
No. 231906), a solution type coating composition comprising a fluorine-containing copolymer that is soluble in an organic solvent and has a hydroxyl group as a functional group and a curing agent has been proposed, and is used for outdoor construction of buildings, bridges, highway side walls, etc. Used in things.

[0003]

However, the above-mentioned fluorine-containing solution type coating composition contains a large amount of an aromatic organic solvent from the viewpoint of the solubility of the fluorine-containing copolymer, and strongly dissolves these solvents. Due to the force, there was a problem such as lifting depending on the type of the undercoat coating film, and the selection range for the undercoat coating film was still narrow. Furthermore, in recent years, global environmental issues have become a hot topic internationally, and regulations on the emission of organic solvents are being advanced. Even in Japan, regulations on coating compositions containing aromatic organic solvents and the like have become more stringent, with the addition of solvents such as toluene and xylene to the Odor Control Law.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a fluorine-containing copolymer composed of specific monomer units is dissolved in an aliphatic organic solvent. In addition, they have found that a coating film having excellent weather resistance is provided, and have completed the present invention.

[0005]

[Means for Solving the Problems] That is, the present invention is based on the total amount of all the constituent monomer units: (a) fluoroolefin monomer unit: 30 to 60 mol%; Carboxylic acid vinyl ester monomer unit represented by [1]: 15 to 50 mol%, (c) acrylic acid hydroxyalkyl ester monomer unit: 1.5 to 15 mol%,
(D) Hydroxyalkyl ester crotonic acid monomer unit and / or hydroxyalkyl vinyl ether monomer unit: Fluorine-containing copolymer composed of 1.5 to 15 mol%, aliphatic organic solvent and curing agent It is a solution type coating composition.

[0006]

Embedded image

(In the formula, R represents an aliphatic, aromatic or alicyclic hydrocarbon group having 5 to 17 carbon atoms)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. Examples of the (a) fluoroolefin monomer in the present invention include vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, and the like. Fluoroethylene, chlorotrifluoroethylene and hexafluoropropylene are preferred, with chlorotrifluoroethylene being especially preferred. Moreover, you may use together two or more types of fluoro olefins. The fluoroolefin monomer unit is
It is 30 to 60 mol% based on the total amount of all structural units. When the amount of the fluoroolefin monomer exceeds 30 mol%, the solubility of the copolymer in the aliphatic organic solvent becomes poor.

Specific examples of the (b) carboxylic acid vinyl ester monomer represented by the above general formula [1] in the present invention include vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, myristin. Vinylate,
Examples thereof include vinyl palmitate, vinyl stearate, vinyl versatate, vinyl cyclohexanecarboxylate, vinyl benzoate and vinyl p-tert-butyl benzoate. Here, in the carboxylic acid vinyl ester monomer in which R has 4 or less carbon atoms in the general formula [1], the obtained copolymer is not dissolved in the aliphatic organic solvent, and therefore these are used in the present invention. I can't.

The carboxylic acid vinyl ester monomer represented by the general formula [1] is 15 to 50 mol% based on the total amount of all the constituent monomer units. If the amount of the carboxylic acid vinyl ester monomer is less than 15 mol%, the solubility of the copolymer in an aliphatic organic solvent is poor, and 50 mol%
If it exceeds, the weather resistance of the copolymer tends to be poor.

Examples of the (c) acrylic acid hydroxyalkyl ester monomer in the present invention include 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate,
Examples thereof include 3-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 4-hydroxymethylcyclohexyl acrylate and caprolactone modified products of hydroxyethyl acrylate. Acrylic acid hydroxyalkyl ester monomer unit is 1.5 to 15 mol% based on the total amount of all constituent monomer units. When the amount of acrylic acid hydroxyalkyl ester monomer unit is less than 1.5 mol%, the gloss of the coating film is poor, and when it exceeds 15 mol%, compatibility with the curing agent is poor.

The crotonic acid hydroxyalkyl ester monomer and / or hydroxyalkyl vinyl ether monomer (d) in the present invention include crotonic acid 2-
Hydroxyethyl, 4-hydroxybutyl crotonic acid,
Crotonic acid 2-hydroxypropyl, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether and 6
-Hydroxyhexyl vinyl ether and the like are mentioned, and 2-hydroxyethyl crotonic acid is preferable in terms of weather resistance and adhesion to a substrate. The amount of these monomer units is 1.5 to 15 mol% based on the total amount of all the constituent monomer units. When the amount of these monomer units is less than 1.5 mol%, the compatibility between the copolymer and the curing agent is poor, and when it exceeds 15 mol%, the weather resistance is poor.

The total amount of acrylic acid hydroxyalkyl ester, crotonic acid hydroxyalkyl ester and hydroxyalkyl vinyl ether in the present invention is
When the proportion of the total constitutional units is less than 3 mol%, curing at the time of film formation is insufficient and a tough coating film cannot be obtained. on the other hand,
When it exceeds 30 mol%, the weather resistance and water resistance are deteriorated.

In the present invention, a radical-polymerizable monomer other than the above monomers may be used. Examples of such radically polymerizable monomers include α-olefins such as ethylene, propylene and isobutylene; chlorinated olefins such as vinyl chloride and vinylidene chloride; allyl compounds such as allyl acetate and allyl butyrate; vinyl acetate, vinyl propionate, pivalin. 2 carbon atoms such as vinyl acrylate and vinyl butyrate
To 4 carboxylic acid vinyl esters having an alkyl group; alkyl vinyl ethers such as ethyl vinyl ether and butyl vinyl ether; crotonic acid esters such as ethyl crotonic acid and propyl crotonic acid; crotonic acid, (meth) acrylic acid and vinyl acetic acid Of α,
Examples include β-unsaturated carboxylic acid.

The fluorinated copolymer comprising the above structural unit in the present invention can be produced by the solution polymerization method described in, for example, JP-A-3-231906. Examples of the polymerization solvent include toluene, xylene, cyclohexane, n-hexane, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethanol, n-butanol, tertiary butanol and mineral spirit. This mineral spirit is a heavy boiling fraction of volatile oil obtained by rectifying petroleum, and generally has an initial distillation point of 14 in the distillation range.
0 ℃ or more, 50% distillation temperature 180 ℃ or less, dry point 20
It is 5 ° C. or less. The polymerization solvent is preferably used in a weight ratio of 0.25 to 4 times that of all the monomers.

Examples of the polymerization initiator include di-2-ethoxyethyl peroxydicarbonate, diisopropyl peroxydicarbonate, tertiary butyl peroxypivalate, peroxides such as benzoyl peroxide and lauroyl peroxide, and azobisisocarbonate. Examples thereof include azo compounds such as butyronitrile and azoisobutylvaleronitrile. The amount of the polymerization initiator used is preferably 0.1 to 5% by weight based on all the monomers.

Using the above-mentioned polymerization solvent and polymerization initiator,
Polymerization temperature 30 ° C to 80 ° C, pressure 5 to 15 kg / c
The fluorine-containing copolymer of the present invention can be obtained by polymerizing the above-mentioned monomer for about 5 to 10 hours at about m ² . A basic compound, an anion exchange resin, hydrotalcites and an epoxy compound may be added to the polymerization solution in appropriate amounts in order to capture an acid generated from the fluoroolefin monomer during the polymerization.

When an aliphatic organic solvent is used as a polymerization solvent in the fluorine-containing copolymer solution obtained by the solution polymerization, the aliphatic organic solvent can be used as it is as a component of a coating composition. It is good, but when other polymerization solvent is used, all the solvent used is evaporated, and the obtained fluororesin is dissolved in an aliphatic organic solvent to obtain a coating composition.

As the aliphatic organic solvent in the present invention, mineral spirits, industrial gasoline No. 4 volatile oil,
No. 3 volatile oil, kerosene, turpentine oil and the like can be mentioned.
Mineral spirit is more preferable from the viewpoint of the dissolving power and the volatilization rate. Mineral spirits are commercially available in various varieties by taking advantage of the characteristics of various components, but the present invention is not limited to any varieties. The aliphatic organic solvent is preferably used so that the solid content of the fluororesin in the coating composition is 20 to 80% by weight.

The curing agent in the present invention is a compound having a plurality of reactive groups with a hydroxyl group in one molecule, such as a polyvalent isocyanate compound or an aminoplast resin. Examples of such polyvalent isocyanate compounds include hexamethylene diisocyanate, isophorone diisocyanate, blocked isocyanate, and the like, and examples of aminoplast resins include melamine resins such as methylated melamine and butylated melamine, benzoguanamine resins, and urea resins. The preferred amount of the polyvalent isocyanate compound used is such that the isocyanate groups are almost equimolar to the hydroxyl groups in the fluorine-containing copolymer, and when the aminoplast resin is used, the fluorine-containing copolymer 10
About 0 to 30 parts by weight of aminoplast resin is preferable per 0 part by weight. A compound that accelerates the curing reaction such as dibutyltin dilaurate and p-toluenesulfonic acid may be used together with the curing agent.

In the preparation of the solution type coating composition in the present invention, in addition to the above-mentioned components, various additives such as pigments, flow control agents, ultraviolet absorbers, dispersion stabilizers and leveling agents, and other resins as required. May be added.

[0022]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. Example 1 (1) Preparation of Fluorine-Containing Copolymer In a 1.5 liter autoclave equipped with a stirrer, 200 g of xylene and vinyl versatate having an alkyl group having 9 carbon atoms (Veoba manufactured by Shell Petrochemical Co., Ltd.) −
9, hereinafter referred to as V-9), 195 g, crotonic acid 2-
After charging 20 g of hydroxyethyl (hereinafter referred to as HEC) and replacing with nitrogen gas, 280 g of chlorotrifluoroethylene (hereinafter referred to as CTFE) was added, and the autoclave was heated to 40 ° C. Next, a mixed solution of 100 g of xylene and 25 g of 4-hydroxybutyl acrylate (hereinafter referred to as HBA) and 30 g of xylene and di-2-ethoxyethyl peroxydicarbonate (Perloyl EEP manufactured by NOF Corporation, hereinafter EEP). 6)
Each of the mixed solutions (g) was charged over 6 hours. afterwards,
The temperature was kept at 40 ° C. with stirring for 3 hours. After the reaction, unreacted CTFE was purged and the autoclave was opened to obtain 700 g of a polymerization reaction liquid.

(2) Evaluation of Physical Properties of Fluorine-Containing Copolymer A part of the above-mentioned polymerization reaction liquid is taken and the number average molecular weight (gel permeation method), fluorine content (fluorine quantitative analysis method), hydroxyl value of the copolymer are taken. Was measured and nuclear magnetic resonance analysis was performed. As a result, the number average molecular weight was 12000 (polystyrene conversion value), the fluorine content was 21.5% by weight, and the hydroxyl value was 46 (mg-KOH / g-resin). Furthermore, the compositional analysis of the polymer was carried out together with the measurement results of ¹ H-NMR and ¹³ C-NMR. As a result, the composition of the copolymer was found to be CTFE / V-9 / HEC / HBA = 50/39/5.
It was recognized that it was / 6 (mol%).

(3) Evaluation of paint film The above-mentioned polymerization reaction solution was dried under reduced pressure to evaporate all of xylene which was a polymerization solvent, and the fluorine-containing copolymer was isolated, and then exon naphtha which was an aliphatic organic solvent. No. 6 (manufactured by Exxon Chemical Co., Ltd., hereinafter referred to as E-6) has a solid concentration of 6
It was dissolved so as to be 0% by weight. 50 g of this 60% by weight solids solution was placed in a glass bottle, and E-6 was added to 30 g.
g, titanium oxide (CR-97 manufactured by Ishihara Sangyo Co., Ltd.) 18
g and 50 g of glass beads were added and dispersed and mixed for 1 hour with a paint conditioner. Then, only the glass beads were separated to obtain a titanium oxide dispersion liquid. 0.7 g of a 0.1% solution of dibutyltin dilaurate and cyclohexane derivative isocyanate (Takenate D-127N manufactured by Takeda Pharmaceutical Co., Ltd.) were added to the titanium oxide dispersion.
0 g was added, and the obtained coating composition was applied to a chromate-treated 0.6 mm aluminum plate with a bar coater and naturally dried at room temperature for 1 week to obtain a coating film having a thickness of 20 μm. The coating film was evaluated by JIS-K5400 and various commonly used methods, and the results shown in Table 1 were obtained. For the gloss retention test, using a fluorescent UV weather resistance tester (made by Q Panel Co., Ltd.), while continuously irradiating light rays, spray ion-exchanged water from the back side of the coated surface every 4 hours to obtain a 60 degree gloss after 4000 hours of testing. The retention rate (%) with respect to the initial glossiness was measured.

Example 2 (1) Preparation of Fluorine-Containing Copolymer To a 1.5 liter autoclave equipped with a stirrer, E was added.
200 g of -6, vinyl versatate having an alkyl group having 10 carbon atoms (Veoba manufactured by Shell Petrochemical Co., Ltd.)
After charging 200 g of 10, hereinafter referred to as V-10) and 20 g of 4-hydroxybutyl vinyl ether (hereinafter referred to as HBVE) and replacing with nitrogen gas, CTFE28
0 g was added and the autoclave was warmed to 40 ° C. Then, a mixed solution of 100 g of E-6 and 30 g of 2-hydroxyethyl acrylate (hereinafter referred to as HEA) and E-6
A mixed solution of 30 g of PEG and 6 g of EEP was charged over 6 hours. Then, the temperature was maintained at 40 ° C. while stirring for 3 hours. After the reaction, unreacted CTFE was purged and the autoclave was opened. As a result, the polymerization reaction liquid was transparent and uniform, and there were no insoluble parts, and 680 g of a polymerization reaction liquid was obtained.

(2) Evaluation of Physical Properties of Fluorine-Containing Copolymer A part of the above-mentioned polymerization reaction liquid was taken and evaluated for physical properties in the same manner as in Example 1. As a result, the number average molecular weight was 15,000 and the fluorine content was 21. 0% by weight, hydroxyl value is 43 (mg-K
OH / g-resin). The composition of the copolymer is CTF
E / V-10 / HBVE / HEA = 51/39/5/5
(Mol%).

(3) Evaluation of paint coating film Next, a paint composition was prepared in the same manner as in Example 1 except that E-6 used as a polymerization solvent was partially used in the composition as it was. The coating film formed in the same manner as above was evaluated. The results are shown in Table 1.

Example 3 (1) Preparation of Fluorine-Containing Copolymer In a 1.5 liter autoclave equipped with a stirrer, 200 g of butyl acetate, 163 g of vinyl cyclohexanecarboxylate (hereinafter referred to as VCH), 12 g of HEC,
After charging 10g of HBVE and replacing with nitrogen gas, CT
300 g of FE was added and the autoclave was heated to 50 ° C. Then, a mixed solution of 100 g of butyl acetate and 60 g of a lactone-modified product of 2-hydroxyethyl acrylate (FA-1 manufactured by Daicel Chemical Industries Ltd., hereinafter referred to as FA), and 30 g of butyl acetate and tertiary butyl peroxydicarbonate. (Perbutyl P manufactured by NOF CORPORATION)
V, hereinafter referred to as BPV) 3.5 g of a mixed solution was charged over 5 hours. Then, while stirring for 4 hours, 5
The temperature was kept at 0 ° C. After the reaction, unreacted CTFE was purged and the autoclave was opened to obtain 710 g of a polymerization reaction liquid.

(2) Evaluation of Physical Properties of Fluorine-Containing Copolymer A part of the above-mentioned polymerization reaction liquid was taken and evaluated for physical properties in the same manner as in Example 1. As a result, the number average molecular weight was 18,000 and the fluorine content was 21.2. % By weight, hydroxyl value is 40 (mg-KOH
/ G-resin). The composition of the copolymer is CTFE /
VCH / FA / HEC / HBVE = 53/38/3/3
It was recognized that it was / 3 (mol%).

(3) Evaluation of Paint Coating Film Next, in the same manner as in Example 1, the above-mentioned polymerization reaction liquid was dried under reduced pressure to evaporate all the butyl acetate as a polymerization solvent, and the fluorine-containing copolymer was converted into E-6. After mixing at a solid content concentration of 60% by weight, the coating composition was prepared and the coating film was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 A 1.5 liter autoclave equipped with a stirrer was charged with 300 g of xylene, 106 g of vinyl propionate (hereinafter referred to as VPr), 37 g of HBA and 6 g of EEP,
After replacing with nitrogen gas, 280 g of CTFE was added, and the autoclave was heated to 40 ° C. Then, the temperature was maintained at 40 ° C. with stirring for 8 hours. After reaction, unreacted CTF
E was purged and the autoclave was opened to obtain 590 g of a polymerization reaction liquid. The above-mentioned polymerization reaction liquid was dried under reduced pressure, and xylene as a polymerization solvent was completely evaporated to isolate a fluorine-containing copolymer, which was mixed with E-6 at a solid content concentration of 30% by weight, but was not dissolved.

Comparative Example 2 A 1.5 liter autoclave equipped with a stirrer was charged with 200 g of xylene and 150 g of vinyl caproate (hereinafter referred to as VCp), and after being replaced with nitrogen gas, CTF was added.
280 g of E was added, and the autoclave was heated to 40 ° C. Then, a mixed solution of 100 g of xylene and 34 g of 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA) and a mixed solution of 30 g of xylene and 6 g of EEP were charged with a high-pressure constant-flow micropump for 6 hours. Then, the temperature was maintained at 40 ° C. while stirring for 5 hours. After the reaction, unreacted CTFE was purged and the autoclave was opened to obtain 630 g of a polymerization reaction liquid. The above-mentioned polymerization reaction liquid was dried under reduced pressure, and xylene which was a polymerization solvent was completely evaporated to isolate a fluorine-containing copolymer.
It was mixed at 0% by weight but did not dissolve.

[0033]

[Table 1]

[0034]

The solution-type coating composition of the present invention is composed of a fluorine-containing copolymer having excellent weather resistance and an aliphatic organic solvent having a low dissolving power, and therefore, compared with a conventional coating composition,
It is a coating composition which has improved selectivity to an undercoating film while maintaining the high weather resistance inherent to a fluorine coating, and also has an adverse effect on the global environment and the human body.

[Procedure amendment]

[Submission date] September 11, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

In preparing the solution-type coating composition in the present invention, in addition to the above-mentioned components, various additives such as pigments, flow control agents, ultraviolet absorbers, dispersion stabilizers and leveling agents, and other resins as necessary. May be added. other
As a resin, compatible with the fluorocopolymer in the present invention
Acrylic resin and polyester resin with properties
Can be The acrylic resin has, for example, a carbon number of 2 to
Acrylic acid or methacrylic acid having 18 alkyl groups
Alkyl ester of acid, vinyl monomer containing hydroxyl group
And other copolymerizable monomers as constituents
The body etc. are mentioned. Mixing fluorinated copolymer and other resins
The ratio is not particularly limited, but is 95/5 by weight.
It is preferably in the range of 20 to 80. Paint composition
Those with a high proportion of fluorine-containing copolymers from the viewpoint of weather resistance
Is preferred.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

(3) Evaluation of Paint Coating Film Next, in the same manner as in Example 1, the above-mentioned polymerization reaction liquid was dried under reduced pressure to evaporate all of butyl acetate as a polymerization solvent, and the fluorine-containing copolymer was converted into E-6. After mixing at a solid content concentration of 60% by weight, the coating composition was prepared and the coating film was evaluated in the same manner as in Example 1, and the results are shown in Table 1. Example 4 The fluorinated copolymer obtained in Example 1 was mixed with ethyl methacrylate.
65% by weight of 2-ethylhexyl methacrylate
5% by weight and 20% by weight of n-butyl methacrylate.
And 2-hydroxyethylmethacrylate 10% by weight
Fluorine-containing copolymer
The weight ratio of polymer to acrylic resin is 75/25
And a resin solution of E-6 having a solid content concentration of 60% by weight.
Prepared. A coating composition was prepared from this resin solution in the same manner as in Example 1.
The product was prepared and the coating film was evaluated. The results are shown in Table 1.
Was.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction contents]

[0033]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C09D 131/02 PFR C09D 131/02 PFR (72) Inventor Hiroshi Inukai Funami-cho, Minato-ku, Aichi Prefecture Address 1 1 Toagosei Co., Ltd. Nagoya Research Institute

Claims (1)

[Claims] 1. A fluoroolefin monomer unit (a): 30-60 based on the total amount of all constituent monomer units.
Mol%, (b) carboxylic acid vinyl ester monomer unit represented by the following general formula [1]: 15 to 50 mol%, (c)
Acrylic acid hydroxyalkyl ester monomer unit:
Fluorine-containing copolymer composed of 1.5 to 15 mol% and (d) crotonic acid hydroxyalkyl ester monomer unit and / or hydroxyalkyl vinyl ether monomer unit: 1.5 to 15 mol%, aliphatic A solution type coating composition comprising an organic solvent and a curing agent. Embedded image (In the formula, R represents an aliphatic, aromatic or alicyclic hydrocarbon group having 5 to 17 carbon atoms)