JP2000017022A - Fluororesin and fluororesin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve solubility in organic solvents, adhesion to a base material and surface hardness by copolymerizing a fluoroolefin, a specific propenyl ether and an another monomer containing a vinyl group. SOLUTION: A composition comprises a fluororesins which has a number- average mol.wt. 500-50,000 (gel permeation chromtography), preferably 2,000-20,000 and a hydroxyl value of 20-120 mg KOH/g obtained by copolymerizing 30-80 mol.% of a fluoroolefin, 10-50 mol.% of a propenyl ether represented by the formula CH3CH=CH-(OR1)n-OH (wherein R1 is a 2C-4C alkylene or a 5C-12C cycloalkylene; and (n) is 1-10) and 0-30 mol.% of an another monomer containing a vinyl group in an aqueous or organic solvent at -20 to 150 deg.C in the presence of a catalyst for polymerization under the atmospheric pressure or a pressurization. The fluororesin composition is obtained by combining a crosslinking agent to a fluororesin so that a ratio of isocyanate groups to hydroxyl groups of the fluororesin is set to 1-2 equivalents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorine-containing copolymer which is excellent in weather resistance, gloss, stain resistance and adhesion to a substrate, and is used for paints, coating materials, protective films, coating films, etc. (Fluorine-containing resin) and a resin composition containing a copolymer thereof.

[0002]

2. Description of the Related Art A fluoroolefin and cyclohexyl vinyl ether copolymer has been reported as a fluororesin used in a room temperature-curable fluororesin coating which does not require baking (Japanese Patent Laid-Open No. 55-254114). Gazettes, etc.), poor compatibility with acrylic resins, and solubility in various organic solvents were not sufficient and were not at a satisfactory level.

Further, a fluorine-containing resin obtained by copolymerizing a hydroxyalkyl vinyl ether with a fluoroolefin has been reported in order to improve solubility in an organic solvent and adhesion to a substrate (Japanese Patent Application Laid-Open No. Sho 55-55). No. 108789). In the fluorine-containing resin, there is an advantage that the adhesion to the substrate is improved because there is a hydroxyl group that increases the adhesion to the substrate, and the urethane group can be formed by reacting the hydroxyl group with the isocyanate group. is there. However, in a coating film application, the adhesion is not always sufficient depending on the type of the substrate (for example, for a plastic material).
Further, when the content of hydroxyalkyl vinyl ether is increased in order to increase the adhesion, there is a problem that physical properties such as hardness are reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide good solubility in an organic solvent and, when applied to a coating film, provide excellent adhesion to a substrate and impart sufficient performance to surface hardness. An object of the present invention is to provide a fluorine-containing copolymer (resin) and a resin composition containing the copolymer.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the use of a fluorine-containing copolymer obtained by copolymerizing a compound having a propenyl ether group and a hydroxyl group with a fluoroolefin allows the above problem to be solved. And found that the present invention could be solved, and completed the present invention.

According to the present invention, 1) a fluoroolefin and a compound represented by the following general formula (1): CH ₃ CH ＝ CH— (OR ¹ ) n —OH (1) wherein R ¹ is a C2-C4 alkylene group or C5-C5
Represents a C12 cycloalkylene group, and n is an integer of 1 to 10. A fluorine-containing resin obtained by copolymerizing the propenyl ether represented by the formula) with another vinyl group-containing monomer. 2) The fluorine-containing resin according to the above 1, which is obtained by copolymerizing the following monomer components (a) to (f): (a) 30 to 80 mol% of a fluoroolefin, (b) general formula (1) CH ₃ CH ＝ CH— (OR ¹ ) n —OH (1) (The symbols in the formula have the same meanings as described in the above 1.) 10 to 50 mol% of (c) alkyl vinyl ether and / or cyclohexyl Vinyl ether 10 to 45 mol% (d) hydroxyalkyl vinyl ether and / or hydroxyalkyl (meth) acrylate 0 to 25 mol% (e) at least one selected from vinyl esters, (meth) acrylates and propenyloxyalkyl esters (F) having a carboxyl group or a glycidyl group, 0) to 30 mol% of a vinyl monomer copolymerizable with the monomer components of (a) to (e). 3) The fluoroolefin is at least one selected from tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene and hexafluoropropylene. The fluorine-containing resin according to the above 1 or 2, which is a compound; 4) the fluorine-containing resin according to the above 2 or 3, wherein the alkyl vinyl ether is a fluoroalkyl vinyl ether; 5) a number measured by gel permeation chromatography (GPC) The fluorine-containing resin according to any one of the above items 1 to 4, which has an average molecular weight of 500 to 50,000 and a hydroxyl value (mgKOH / g) of 20 to 120; The present invention relates to a fluorine-containing resin composition containing a resin and a crosslinking agent.

According to the present invention, by introducing a propenyl ether of the general formula (1) into a structure in a fluororesin,
The solubility in a solvent and the adhesion to a substrate after curing can be improved.

The propenyl ether represented by the general formula (1) according to the present invention can be produced, for example, by isomerizing the corresponding polyalkylene glycol monoallyl ether or polycycloalkylene glycol monoallyl ether. Such isomerization of allyl ether to propenyl ether is carried out by, for example, Ru or R
The reaction can be performed at a high temperature using a h, Pd metal complex as a catalyst, or by a known method using an alkali catalyst such as potassium t-butoxide in a solvent.

In the general formula (1), n is an integer of 2 to 10, preferably n = 1 to 3. R ¹ is C
A C2-C4 alkylene group or a C5-C12 cycloalkylene group; examples of the alkylene group include-
CH ₂ —CH ₂ —, — (CH ₃ ) CH—CH ₂ —, — (CH
_{2) 3 -, - (CH} 2) 4 -, - (CH 3) CH- (CH 2)
_2-, and examples of the cycloalkylene group include a cyclohexylene group, a cyclooctylene group, and a cyclododecylene group. It is particularly preferable that the fluorine-containing resin has an excellent balance of maintaining the solubility and the physical properties, when R ¹ is —CH ₂ —CH ₂ —, — (CH ₃ ) CH—C
H ₂ —, — (CH ₂ ) ₃ —, where n = 1 to 3.
Specific examples include ethylene glycol monopropenyl ether, diethylene glycol monopropenyl ether, triethylene glycol monopropenyl ether,
Examples include propylene glycol monopropenyl ether, dipropylene glycol monopropenyl ether, and tripropylene glycol monopropenyl ether.

The composition ratio of the propenyl ether of the general formula (1) is from 10 to 50 mol%, preferably from 10 to 30 mol%, based on the total monomers constituting the copolymer. 10
If it is at most mol%, the solubility of the fluororesin in the solvent will decrease, and the adhesion to the substrate will decrease. If it exceeds 50 mol%, it is not preferable because physical properties such as heat resistance and weather resistance are reduced.

Examples of the fluoroolefin used in the present invention include tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, monofluoroethylene, hexafluoropropylene, hexafluoroisobutene, vinyl fluoride and the like.

[0012] The composition ratio of the fluoroolefin is 30 to 80 mol%, preferably 40 to 60 mol%, based on the total monomers constituting the copolymer. If it is more than 80 mol%, the solubility of the fluorine-containing resin in the solvent is extremely reduced, which is not preferable. On the other hand, if it is less than 30 mol%, weather resistance and chemical resistance are undesirably reduced.

The hydroxyvinyl ether for the copolymer according to the present invention includes, for example, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyhexyl vinyl ether, hydroxypentyl vinyl ether and the like.

Examples of the hydroxyalkyl (meth) acrylate include hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate and the like.

The alkyl vinyl ether is, for example, methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, propyl vinyl ether, butyl vinyl ether, or the like, or a fluoroalkyl vinyl ether in which a part of the alkyl hydrogen atoms of the alkyl vinyl ether is substituted with a fluorine atom. , 2,2-trifluoroethyl vinyl ether, 2,2,3,3-tetrafluoropropyl vinyl ether, 2,2,3
3,3-pentafluoropentyl vinyl ether, 2,
Fluoroalkyl groups such as 2,3,3,4,4,5,5-octafluoropentyl vinyl ether have 1 carbon atom
And 10, preferably 2 to 6 fluoroalkyl vinyl ethers.

The vinyl ester used in the present invention may be any ester compound having a vinyl group, for example, an aliphatic compound such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl stearate and vinyl caproate. Vinyl esters of carboxylic acids, alicyclic vinyl esters such as cyclohexane carboxylic acid vinyl ester, etc., aromatic vinyl esters such as vinyl benzoate, vinyl t-butyl benzoate, hydroxyethyl vinyl ester, hydroxypropyl vinyl ester, hydroxybutyl Examples include hydroxyalkyl vinyl esters such as vinyl esters.

The (meth) acrylate used in the present invention includes methyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and (meth) acrylic acid. Allyl and the like.

The propenyloxyalkyl ester may be any ester compound having a propenyloxyalkyl group, for example, propenyloxyethyl acetate, propenyloxypropyl acetate, oxyethyl propionate, propenyloxypropyl propionate, benzoate Acid propenyloxyethyl ester, benzoic acid propenyloxypropyl ester, cyclohexanecarboxylic acid propenyloxyethyl ester, cyclohexanecarboxylic acid propenyloxypropyl ester, and the like.

The vinyl monomer having a carboxyl group or glycidyl group and copolymerizable with the monomer components (a) to (e) used in the present invention is a compound having a vinyl group and a carboxyl group or a glycidyl group. There is no particular limitation as long as it exists. For example, vinyl acetic acid, decenoic acid, crotonic acid, undecylenic acid, dodecylenic acid, allyl glycidyl ether, vinyl glycidyl ether, 3,4-
Epoxy cyclohexyl methyl vinyl ether, 3,4
-Epoxycyclohexyl (meth) acrylate and the like. These monomers contribute to improving the adhesion to the substrate.

The above copolymerizable monomers may be used alone or in combination of two or more.

The fluorine copolymer of the present invention can be prepared by a method such as solution polymerization, emulsion polymerization, suspension polymerization or bulk polymerization using a polymerization catalyst at a temperature of -20 to 150 ° C. under normal pressure or pressure. To obtain a copolymer.

Examples of the polymerization catalyst include organic peroxides such as acyl peroxide, alkyl peroxide and dialkyl peroxide, inorganic peroxides such as hydrogen peroxide, potassium persulfate, ammonium persulfate and percarbonate, and azo peroxides. An azo compound such as bisisobutyronitrile is exemplified.

Aqueous and organic solvents can be used as the solvent used in the polymerization. Organic solvents include toluene, aromatic hydrocarbons such as xylene, tetrahydrofuran, ethers such as diethyl ether, methanol, ethanol,
Alcohols such as isopropyl alcohol and butanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, ethyl cellosolve, butyl cellosolve, dimethylformamide, N-methyl-pyrrolidone and the like can be used. When polymerization is carried out in an aqueous system, an emulsifier or a suspending agent is used.

In such a polymerization reaction, a weakly basic alkali metal salt such as potassium carbonate or sodium carbonate may be added to promote the polymerization.

The fluorine-containing copolymer of the present invention has a number average molecular weight (Mn) of from 500 to 50,000, preferably by gel permeation chromatography (GPC).
It is in the range of 2,000-20,000. When Mn is 500 or less, the physical properties of the coating resin when crosslinked are reduced. If it is more than 50,000, handling at the time of coating becomes poor.

In the present invention, a fluorine-containing copolymer is obtained by polymerizing using a polymerizable monomer having a hydroxyl group. However, since the copolymer contains a hydroxyl group, a crosslinking agent which reacts with the hydroxyl group is obtained. As a resin composition containing, and, if desired, other components, a curable resin composition suitable for the intended use can be obtained. The hydroxyl group content is determined by the type of the crosslinking agent, the curing temperature, and the type of the curing catalyst, and is desirably selected from the above composition range according to the purpose.

The fluorine-containing copolymer of the present invention has a hydroxyl value (mg KOH / g) in the range of 20 to 120. 2
If it is less than 0, the degree of cross-linking is reduced, and the physical properties of the cured film are reduced.

Examples of the crosslinking agent include compounds having two or more functional groups, for example, hexamethylene dissocyanate, trimer of hexamethylene diisocyanate,
Polyisocyanates such as xylylene diisocyanate, tolylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, blocked isocyanate, acid anhydrides such as phthalic anhydride and hexahydrophthalic anhydride, polyamines, amino resins, epoxy resins and so on. The compounding amount of the crosslinking agent is 1 to 2 equivalents (in the isocyanate group) based on the hydroxyl group of the fluorine-containing copolymer.
It is.

The curing reaction is carried out at a temperature of from room temperature to 180 ° C., and the reaction is accelerated by adding a curing catalyst.

When the fluorine-containing resin composition of the present invention is applied as a coating material or a coating material, it can be used by dissolving it in a solvent. Examples of the solvent include toluene, aromatic hydrocarbons such as xylene, ethanol, isopropyl alcohol, alcohols such as butanol, acetone,
Ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, ethyl cellosolve, butyl cellosolve and the like can be used.

Depending on the application, additives such as colorants, pigments, metal powders, glass, ultraviolet absorbers, dispersion stabilizers, leveling agents, thickeners, defoamers, fillers, etc. may be added as necessary. It can also be added.

[0032]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 59 g (15 mol%) of vinyl pivalate and ethylene glycol monopropenyl ether 10 in a 2-liter stainless steel autoclave equipped with a stirrer
3 g (20 mol%), 54 g of ethyl vinyl ether (1
5 mol%), 300 g of butyl acetate, 2 g of potassium carbonate,
4 g of azobisisobutyronitrile was charged and the inside of the autoclave was replaced with nitrogen. The inside of the autoclave was cooled with liquid nitrogen to degas the inside, and 290 g (50 mol%) of chlorotrifluoroethylene was introduced. Thereafter, the temperature was carefully raised to control the internal temperature of the reaction vessel at 60 to 70 ° C., and the reaction was carried out for 18 hours. Thereafter, the mixture was cooled to room temperature to remove unreacted raw materials and opened. The obtained copolymer solution was filtered through a membrane filter, and then filtered by reprecipitation treatment with hexane as a poor solvent to obtain a solid content of the copolymer. Table 1 shows the hydroxyl value, molecular weight and the like. The molecular weight Mn was determined by using gel permeation chromatography (GPC). 10 g of this copolymer
Was dissolved in 50% by weight of butyl acetate, hexamethylene diisocyanate was added in an amount corresponding to 1.5 equivalents of the hydroxyl value of the fluorine-containing copolymer, and 0.001 g of dibutyltin oxide was further mixed with the catalyst, followed by painting on an aluminum plate. Then 30
A micron coating was dried at room temperature for one week to produce a coating. Table 1 shows the results obtained by measuring the adhesion and physical properties of the pencil hardness of the coating film.

Examples 2 to 4: Polymerization was carried out in the same manner as in Example 1 except that the types of raw materials and the charged composition ratio were changed as shown in Table 1, to obtain a fluorine-containing copolymer. The coating on the aluminum plate was performed in the same manner. Physical properties and evaluation results are also shown in Table 1.

Comparative Example 1 In the same manner as in Example 1, without using the propenyl ether represented by the general formula (1),
The fluorine-containing resin was used in the compounding system shown in Table 1. The results of the physical properties of the coated film are also shown in Table 1.

[0035]

[Table 1]

The methods for evaluating various physical properties shown in Table 1 are as follows. [Solubility] Solubility when a fluorine-containing resin, a crosslinking agent and a solvent are mixed. Transparent ones were marked with ○, and opaque ones were marked with x. [Adhesion] A cross-cut peeling test according to JIS-K5400 was conducted, and the 1 mm square 100 was peeled off with a cellophane tape.
The peeled cells were confirmed. For 100 squares,
The following judgment method was carried out by confirming a part which was not peeled off. ：: 100/100 (not peeled off at all), Δ: 90 to 99/100, ×: 0 to 89/100. [Pencil hardness] According to JIS-K5400. [Solvent resistance] When the surface of the coating film was wiped with absorbent cotton containing methyl ethyl ketone, there was no change in the surface, and when there was no change, the case was not good.

[0037]

As can be seen from the examples and comparative examples,
The resin composition containing the fluorine-containing copolymer of the present invention containing a fluoroolefin and a propenyl ether represented by the general formula (1) as essential monomer components impairs the physical properties of a conventionally obtained fluororesin-based coating film. Without this, a coating film having excellent adhesion to a substrate and excellent hardness can be provided.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Uchida 2nd floor in Oita City, Oita Prefecture Showa Denko Oita Plant F-term (reference) 4J002 BD121 BD141 BD151 BD161 EL136 ET006 FD146 4J100 AC24P AC26P AC27P AC30P AE09Q AE09R AE09T AE19S AG02T AG04T AG05T AG08T AL03T AL08T AL09S BA03Q BA08Q BB17R BC04R BC04T BC43T BC54T DA01 DA30 JA01

Claims (6)

[Claims] 1. A fluoroolefin and a compound represented by the general formula (1): CH ₃ CH ＝ CH— (OR ¹ ) n —OH (1) wherein R ¹ is a C2-C4 alkylene group or C5-C4
Represents a cycloalkylene group of C12, and n is an integer of 1 to 10. A fluorine-containing resin obtained by copolymerizing the propenyl ether represented by the formula) with another vinyl group-containing monomer. 2. The fluorine-containing resin according to claim 1, which is obtained by copolymerizing the following monomer components (a) to (f): (a) 30 to 80 mol% of a fluoroolefin; _{(1) CH 3 CH = CH-} (OR 1) n-OH (1) propenyl ether 10-50 mol% represented by (the symbols in the formula. where the same meanings as described claim 1) (c) Alkyl vinyl ether and / or cyclohexyl vinyl ether 10 to 45 mol% (d) hydroxyalkyl vinyl ether and / or hydroxyalkyl (meth) acrylate 0 to 25 mol% (e) vinyl ester, (meth) acrylate ester and propenyloxyalkyl ester At least one selected from the group consisting of 0 to 30 mol% (f) a carboxyl group or a glycidyl group; And 0 to 30 mol% of a vinyl monomer copolymerizable with the monomer components (a) to (e). 3. The fluorine-containing resin according to claim 1, wherein the fluoroolefin is at least one compound selected from tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene and hexafluoropropylene. 4. The fluorine-containing resin according to claim 2, wherein the alkyl vinyl ether is a fluoroalkyl vinyl ether. 5. A gel permeation chromatography (G
PC) has a number average molecular weight of 500 to 50,000,
The fluorine-containing resin according to any one of claims 1 to 4, wherein the hydroxyl value (mgKOH / g) is 20 to 120. 6. A fluorine-containing resin composition comprising the fluorine-containing resin according to claim 1 and a crosslinking agent.