JP3160002B2 - Curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel hardening compositions.

[0002]

2. Description of the Related Art Fluorine-containing copolymers obtained by copolymerizing polyfluoroolefins and alkyl vinyl ethers are known, are used as solvent-soluble, room temperature-curable coating materials, and have weather resistance and chemical resistance. It is known that a coating film having excellent properties, gloss and the like can be obtained, and a coating film having excellent adhesion to a substrate can be obtained.

[0003]

In recent years, with the spread of applications of fluorine-based solvent-based paints, there has been a growing demand for a wide range of paints from rubber-elastic paints to paints with high surface hardness. However, conventional fluorine-based solvent-based paints have a limit in improving surface hardness, and such improvements are strongly demanded.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and includes a radical polymerizable fluorine-containing monomer, a 1,3-dioxole compound represented by the formula 1, and A curable composition comprising a fluorine-containing copolymer obtained by copolymerizing a curable functional group-containing monomer copolymerizable with a fluorine-containing copolymer in the presence of a radical polymerization initiation source and a curing agent . However, R ¹ and R ² in Formula 1 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group or a fluoroalkyl group.

[0005]

Embedded image

The radical polymerizable fluorine-containing monomer used in the present invention includes fluorine-containing olefins such as tetrafluoroethylene, chlorotrifluoroethylene and hexafluoropropylene, perfluorovinyl ether, polyfluoroalkyl acrylate, methacrylic acid Examples thereof include polyfluoroalkyl esters and polyfluorocarboxylic acid vinyl esters.

In particular, the fluorine-containing olefin is copolymerizable,
Further, it is preferably used from the viewpoints of the weather resistance of the coating film when the fluorinated copolymer is used as a coating base and the recoating property of the coating film.

Examples of the fluorine-containing olefin include vinylidene fluoride and trifluoroethylene in addition to the above compounds. Particularly, a perhaloolefin having 2 to 4 carbon atoms is preferable.

Further, as the 1,3-dioxole compound in the present invention, the compound represented by the above formula 1 is employed. As disclosed in JP-A-2-124908,
When a dioxole compound having a fluorine-substituted unsaturated group is used, only a polymer that is soluble only in a special solvent is obtained, which is not preferable.

Specifically, 2,2-dimethyl-1,3-
Dioxol, 2,2-diisopropyl-1,3-dioxole, spirocamphor-1,3-dioxole,
Examples thereof include 2-chloro-2-trifluoromethyl-1,3-dioxole.

In particular, a 1,3-dioxole compound in which R ¹ and R ² in the formula 1 are a hydrogen atom or an alkyl group or a cycloalkyl group having 1 to 10 carbon atoms can be used as a solvent for the obtained fluorine-containing copolymer. It is preferable in terms of solubility and the like.

In the present invention, the radical polymerizable fluorine-containing monomer and the 1,3-dioxole compound may be copolymerized by one kind or plural kinds. Further, other ethylenically unsaturated monomers copolymerizable therewith may be copolymerized simultaneously. Examples of such ethylenically unsaturated monomers include vinyl ether compounds, vinyl ester compounds, allyl ether compounds, allyl ester compounds, isopropenyl ether compounds, isopropenyl ester compounds, α-olefins and the like. You.

It is preferable that the ethylenically unsaturated monomer is appropriately selected depending on additional purposes such as gloss of a coating film and dispersibility of a pigment. Considering solvent solubility, control of coating film hardness, weather resistance, and the like, vinyl ether compounds or vinyl ester compounds are preferred. In particular, a vinyl ether or vinyl ester having a linear, branched or alicyclic alkyl group having about 2 to 15 carbon atoms is preferable.

Further, in the present invention, in order to enhance the toughness and solvent resistance of the coating film from the fluorine-containing copolymer, it is necessary to cure a hydroxyl group, an epoxy group, an amino group, an active hydrogen-containing group or an alkoxysilyl group. A monomer containing an acidic functional group is copolymerized. Examples of such a curable functional group-containing monomer include a hydroxyl group-containing vinyl ether such as hydroxybutyl vinyl ether, a hydroxyl group-containing allyl compound such as allyl alcohol, an epoxy group-containing vinyl ether such as glycidyl vinyl ether, and an amino group-containing vinyl ether such as aminobutyl vinyl ether. Examples include alkoxysilyl group-containing vinyl compounds such as methoxyvinylsilane. As the curable functional group-containing monomer, a hydroxyl group-containing vinyl ether or an epoxy group-containing vinyl ether is preferably employed.

[0015] The copolymerization of each monomer is carried out by using a radical polymerizable fluorine-containing monomer and a 1,3-dioxole compound.
It is preferable to carry out at a ratio of / 95 to 95/5 (molar ratio). Outside the above range, it is not preferable in terms of weather resistance, solvent solubility and production efficiency.

A radically polymerizable fluorine-containing monomer,
When a monomer other than the 1,3-dioxole compound is copolymerized, the total amount of the radical polymerizable fluorine-containing monomer and the 1,3-dioxole compound is 60 with respect to all the monomers.
It is preferably at least mol%. If it is less than this range, the object of the present invention may be impaired.

The copolymerization of the curable functional group-containing monomer is preferably carried out within a range of 5 to 20 mol% based on all monomers. If the proportion of the curable functional group-containing monomer is too large, the storage stability of the paint is reduced when the obtained fluorine-containing copolymer is used for paint, or the coating film may be brittle, which is not preferable. . If the amount is too small, curing may not be sufficiently performed, which is not preferable.

Furthermore, other monomers, depending on the purpose, wear amount thereof in appropriate selection constant. For example, when a vinyl ether or a vinyl ester is used, when the content is 10 to 40 mol% based on all monomers, excellent properties such as solubility in a solvent, dispersibility of a pigment and the like, and gloss of a coating film can be obtained.

When a fluorine-containing olefin is used as the radically polymerizable fluorine-containing monomer, the ratio of the fluorine-containing olefin is particularly preferably 40 to 60 mol% based on all monomers. If the proportion of the fluorinated olefin is too large, the resulting fluorinated copolymer may not be sufficiently soluble in a solvent.

The copolymerization in the present invention can be carried out by the following method or the like. In particular, since 1,3-dioxole compounds tend to cause isomerization, decomposition, or homopolymerization in an acidic state, it is preferable to carry out the reaction under basic conditions in order to stably promote copolymerization. It is particularly preferable to carry out the reaction at a pH of about 8 to 9.

The copolymer that put the present invention has an intrinsic viscosity of 0.05~2.0dl / g as measured at 30 ° C. in tetrahydrofuran in the uncured state, preferably 0.10 to 1.
0 dl / g, more preferably 0.2 to 0.8 dl / g
It is something that is. If the viscosity is too low, the mechanical strength is reduced, and if it does not have a curable functional group, the solvent resistance of the coating film will not be sufficiently obtained, while if it is too high, it will be used as a solution type paint. In addition, the solution concentration tends to be lowered from the viewpoint of viscosity, and the workability is impaired.

[0022] As you Keru radical polymerization initiating source in the present invention include a radical polymerization initiator and ionizing radiation. Here, as the polymerization initiator, a water-soluble one or an oil-soluble one can be appropriately used depending on the polymerization type or the polymerization medium.

Specifically, the water-soluble initiator includes a redox initiator comprising a persulfate such as potassium persulfate, hydrogen peroxide or a combination thereof with a reducing agent such as sodium hydrogen sulfite or sodium thiosulfate; Furthermore a small amount of iron to, ferrous salts, inorganic initiators such systems are allowed to coexist, such as silver nitrate, or disuccinic acid peroxide, jiggle Tal acid peroxide, dibasic acid peroxides such as monosuccinate peroxide, azo Organic initiators such as bisisobutylamidine dihydrochloride, and t-butyl peroxyisobutyrate, t
Examples thereof include peroxyester-type peroxides such as -butylperoxyacetate, dialkylperoxydicarbonates such as diisopropylperoxydicarbonate, benzoyl peroxide, azobisisobutyronitrile and the like.

The amount of the polymerization initiator to be used can be appropriately changed depending on the kind, copolymerization reaction conditions and the like.
In particular, about 0.05 to 0.5% by weight is employed.

In the above-mentioned copolymerization reaction, the type of reaction is not particularly limited, and bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization and the like can be employed. from easiness of separation, emulsion polymerization or xylene, aromatic compounds such as toluene in an aqueous medium, t-Bed alcohols such Chiruaruko Lumpur, esters, saturated halogenated containing one or more fluorine atoms Solution polymerization using hydrocarbons or the like as a solvent is preferably employed.

When the copolymerization reaction is carried out in an aqueous medium, it is preferable to add a basic buffer so that the pH value of the solution during the polymerization does not fall below 7, especially below 8. The addition of a basic substance is also effective in the case of solution polymerization. In addition, the method for producing the fluorine-containing copolymer in the present invention can be performed by a batch system, a semi-continuous system, a continuous system, or the like.

In such a copolymerization reaction, the copolymerization reaction temperature can be appropriately selected within the range of -30 ° C. to + 150 ° C. depending on the polymerization initiation source, the type of the polymerization medium, and the like. 0 ° C. to +10 when performing the polymerization reaction
0 ° C., preferably about 10 ° C. to 90 ° C. may be employed.
Further, the reaction pressure can be appropriately selected, but is usually 1 to 10
It is desirable to adopt 0 kg / cm ² , especially about ² to 50 kg / cm ² .

In order to control the intrinsic viscosity of the produced copolymer within the above range, a copolymerization reaction may be appropriately carried out in the presence of a chain transfer agent. The fluorine-containing copolymer in the present invention, a hydroxyl group as a curable functional group in the copolymer,
Since an epoxy group or the like has been introduced, it can be cured at about 0 ° C. to 250 ° C. using a curing agent to form a coating film having a crosslinked structure. The curable composition of the present invention contains
Consists of a fluorine copolymer and a curing agent.

That is, a melamine curing agent, a urea resin curing agent, a polybasic acid curing agent as used in acrylic paints,
Heat curing can be performed using a block polyvalent isocyanate curing agent or the like. The melamine curing agent, butylated melamine, methylated melamine, epoxy-modified melamine is illustrated, depending on the application, can be used any of various modification degree of 0-6, self-condensation degree can also be suitably selection. Examples of the urea resin curing agent include methylated urea, butylated urea, and the like. As the polybasic acid curing agent, long-chain aliphatic dicarboxylic acids, aromatic polycarboxylic acids or anhydrides thereof are useful. When using a melamine curing agent or a urea resin curing agent, curing can be promoted by adding an acidic catalyst.

Further, the copolymer that put the present invention may be further cured at room temperature using a polyvalent isocyanate compound. As polyvalent isocyanates, non-yellowing diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and adducts thereof are particularly useful. When to perform cold cured with polyvalent isocyanates can also be accelerated curing by addition of a known catalyst such as dibutyltin dilaurate.

A curing agent is blended to form a curable composition.To
Is 5 to 1 curing agent per 100 parts by weight of the fluorocopolymer.
Preferably it is 00 parts by weight.

[0032] The put that copolymers of the present invention in a solution type paint, various solvents may be used, such as xylene, such aromatic hydrocarbons such as toluene, such as alcohols n- butanol, butyl acetate In addition to esters, ketones such as methyl isobutyl ketone, and glycol ethers such as ethyl cellosolve, various commercially available thinners can also be used.

Mixing of such a copolymer with a solvent can be carried out using various equipments used for ordinary coating, such as a ball mill, a paint shaker, a sand mill, a jet mill, a three-roll mill and a kneader. At this time, a pigment, a dispersion stabilizer, a viscosity modifier, a leveling agent, an anti-gelling agent, an ultraviolet absorber and the like can also be added.

[0034] When the put that copolymers of the present invention to heat-curable so-called baking paint, upon the mixing, melamine, urea resin, polybasic acids or anhydrides thereof, such as block polyisocyanate compound A curing agent is also mixed at the same time and used as a one-pack type paint.

On the other hand, in the case of a room temperature-curable coating using non-block polyvalent isocyanates, the curing agent component is separately prepared to form a two-pack type coating. In this case, by adjusting the type and amount of the isocyanate and the catalyst, the copolymer concentration, the content of the unit based on hydroxyalkyl vinyl ether in the copolymer, etc., 1
It has a pot life of about 10 to 10 hours and can be cured at room temperature in several hours to several days to give a coating film having good physical properties.

[0036] Co that put the present invention polymers, when used as a paint base, surface hardness, excellent gloss, solvent resistance, excellent stain resistance and mild coating film having excellent weather resistance It can be given under conditions and is useful not only as a baking paint for color steel plates, color aluminum plates, aluminum sashes and the like, but also as an on-site workable dry paint.

The material of the base material is not limited to metal, but inorganic materials such as glass, cement, concrete, etc., FRP, polyethylene, polypropylene, ethylene-vinyl acetate copolymer,
It is also extremely useful for coating organic materials such as plastics such as nylon, acrylic resin, polyester, ethylene-polyvinyl alcohol copolymer, polyvinyl chloride and polyvinylidene chloride, and wood. They are also useful in certain applications, such as aluminum pools, exterior colored glass, cement roof tiles, and the like.

[0038]

The present invention will be described more specifically with reference to the following examples. Examples 1 to 6 are Reference Examples, Examples 7 to 11 are Examples, and Examples 12 and 13 are Comparative Examples.

Example 1 In a 200 cc stainless steel autoclave with a stirrer (withstand pressure of 25 kg / cm ² ), 39.
0 g, 11.0 g of ethyl alcohol, 11.8 g of 2,2-dimethyl-1,3-dioxole, 0.27 g of potassium carbonate and 0.1 g of azobisisobutyronitrile.
11 g was charged, and dissolved air was removed by solidification with liquid nitrogen and deaeration. Thereafter , 13.7 g of chlorotrifluoroethylene was introduced into the autoclave, and the temperature was gradually raised. When the temperature in the autoclave reached 65 ° C., the pressure showed 3.5 kg / cm ² G. Thereafter, the reaction was continued under stirring, and after 5 hours, the pressure was 1.4 kg / cm ^2.
G reached. After cooling the autoclave with water and stopping the reaction,
After reaching room temperature, unreacted monomers were purged and the autoclave was opened. The obtained polymer solution was poured into a water / methanol mixture to precipitate a polymer, followed by washing,
Drying was performed. 15.4 g of the polymer was obtained with a yield of 60.5%.

10 g of the obtained polymer was dissolved in 1 of xylene.
0 g, applied to a chromated aluminum plate using an applicator, and dried at 140 ° C. for 30 minutes. The pencil hardness of the obtained coating film (about 20 μm thickness) is 2H
Met.

Examples 2 to 6 Polymerization was carried out in the same manner as in Example 1 except that the conditions were changed as shown in Table 1. In addition, Table 1 shows the results of measuring the pencil hardness using the obtained fluorinated copolymer in the same manner as in Example 1.

The abbreviations described in Tables 1 and 3 are as follows. The unit of the numerical value in the column of monomer in Tables 1 and 3 is mol%. CTFE is chlorotrifluoroethylene, TFE is tetrafluoroethylene, 2M-1,3-DOX is 2,2-dimethyl-1,3-dioxole, 2IP-1,3-DOX is 2,2-diisopropyl-
1,3-dioxol, SC-1,3-DOX is spirocamphor-1,3-dioxole, CHVE is cyclohexyl vinyl ether, EVE is ethyl vinyl ether, and HBVE is ω-hydroxybutyl vinyl ether.

[0043]

[Table 1]

Example 7 200 cc stainless steelsteelAuto with stirrer
Clave (withstand pressure 25 kg / cm^Two), 7 of xylene
7.3 g, 27.6 g of ethanol, 2,2-dimethyl
9.4 g of -1,3-dioxole, ethyl vinyl acetate
6.8 g of tel, ω-hydroxybutyl vinyl ether
10.9 g of potassium carbonate, 0.58 g of potassium carbonate and azobi
Charge 0.22 g of isobutyronitrile and add liquid nitrogen
Dissolved air was removed by solidification and degassing.afterwards
27.3g of chlorotrifluoroethylene
The mixture was introduced into a clave and gradually heated. In autoclave
When the temperature of the mixture reaches 65 ° C., the pressure is 3.5 kg / cm^Two
G is indicated. After that, the reaction was continued under stirring for 7 hours,
0.2kg / cm^TwoAutoclave when dropped to G
Was cooled with water to stop the reaction. After reaching room temperature, unreacted
Nomer was purged and the autoclave was opened. Obtained
Polymer solution was poured into water to precipitate the polymer.
Thereafter, the polymer was washed and dried to recover the polymer. Polymer yield
The amount was 43.5 g and the monomer conversion was 80.0%.
there were.

10 g of the obtained polymer was dissolved in a mixed solvent of 4 g of xylene and 12 g of methyl isobutyl ketone, and titanium oxide (CR-90, manufactured by Ishihara Sangyo) was dissolved in 4.
2 g was added and mixed for 1 hour with a paint shaker.
The obtained paint was in a state of good dispersion (a particle gauge of 3 μm or less). Thereto, 1.5 × of 0.8g and dibutyl tin dilaurate hexamethylene diisocyanate
10 ^-7 g was added, and the mixture was applied to a chromated aluminum plate using an applicator.

After about 8 hours, the coating becomes tack-free. After 3 days, the coating is not eroded by wiping with xylene.
A robust coating of 0 μm was obtained. Surface gloss (60 ° -60
°) was 79. When the coating film was subjected to JIS and various tests generally performed, the results shown in Table 2 were obtained. In addition, the trace of felt-tip pen remains, A shows no trace, B
Indicates that there is almost no trace, and C indicates that there is some after.

[0047]

[Table 2]

Examples 8 to 13 Polymerization was carried out under the same conditions as in Example 7 except that the conditions were changed as shown in Table 3. Table 3 shows the results of the same evaluation test as in Example 7.

[0049]

[Table 3]

[0050]

Coating obtained from the curable composition of the present invention according to the present invention <br/> a conventional fluorine-containing olefin / alkyl vinyl ether copolymer, coatings based on fluorine-containing olefin / vinyl ester copolymer Has weather resistance, chemical resistance, and antifouling properties comparable to that of, and has a wide coating hardness (especially high hardness)
Can control.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI C09D 127/12 C09D 127/12 (58) Investigated field (Int.Cl. ⁷ , DB name) C08L 27/12-27/20 C08F 214/18-214/28 C08F 216/14-216/20 C08F 220/22-220/24 C08F 234/00-234/04 C09D 127/12-127/20

Claims (2)

(57) [Claims] 1. A radical-polymerizable fluorine-containing monomer, a 1,3-dioxole-based compound represented by the formula 1, and a curable functional group-containing monomer copolymerizable therewith in the presence of a radical polymerization initiation source. fluorocopolymer obtained by copolymerizing a well
A curable composition comprising a curing agent . Where R in the formula 1
¹ and R ² are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, a cycloalkyl group or a fluoroalkyl group. Embedded image 2. A curable functional group-containing monomer, curable composition according to claim 1 is a hydroxyl group-containing vinyl ether or epoxy group-containing vinyl ether.