JPH02191653A - Non-aqueous dispersion of fluorine-containing copolymer, production thereof and use thereof - Google Patents

Abstract

PURPOSE:To obtain the subject dispersion suitable for coating material able to give coated film having excellent stability, weatherability and transparency by mixing a fluorine-containing copolymer unable to solely disperse in an organic solvent and fluorine-containing copolymer able to be solely dissolved or dispersed in said solvent into said solvent. CONSTITUTION:In an organic solvent (e.g. hexane), (B) a monomer to be fluorine-containing copolymer unable to be solely dissolved or stably dispersed is polymerized in the presence of (A) a fluorine-containing copolymer abel to be solely dissolved or stably dispersed in said solvent. Fluorine-containing copolymers A and B such as fluorine-containing copolymer A having a SP value >=1.8 different from the value (solubility coefficient) of organic solvent and fluorine-containing copolymer B having a SP value <=1.8 different from the value of the organic solvent are preferably used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a non-aqueous dispersion of a fluorine-containing copolymer, a method for producing the same, and uses thereof.

EConventional technology 1 Conventional copolymers of fluoroolefins, cyclohexyl vinyl ether, and various other monomers are soluble in organic solvents at room temperature, and are transparent and have high gloss when used as paints. Moreover, it is known to provide coating films with the excellent properties of fluororesins, such as high weather resistance, water and oil repellency, stain resistance, and non-adhesion.
No. 44083) Its use is increasing in fields such as architecture.

On the other hand, a method is described in which a stable non-aqueous dispersion paint is produced by polymerizing a radically polymerizable unsaturated monomer using the above-mentioned fluororesin as a dispersion stabilizer and an aliphatic hydrocarbon as a solvent.

Compared to solvent-based paints, such non-aqueous dispersion type paints are preferable from the viewpoint of air pollution because they can mainly use aliphatic hydrocarbons, which are less toxic and photochemically inactive, as dispersion media. It is expected to be used as a new form of paint because of its excellent paintability.

However, the above-mentioned fluorine-containing non-aqueous dispersion paints only provide opaque coatings, and acrylic acid or methacrylic acid, which is preferably used as a monomer to be polymerized in the presence of a dispersion stabilizer resin and an organic medium, Polymers of monomers or monomer mixtures containing at least 40% by weight of esters have problems with weather resistance, and when used in practice by mixing them with the solvent-based fluororesin paints, the weather resistance decreases and the fluororesin paints In fact, the clear coating film formed with this composition shows a significant decrease in gloss, yellowing, water spots, etc. when tested using an accelerated weather resistance tester, and has poor weather resistance compared to the solvent-based fluororesin coating. significantly inferior in quality.

[Problems to be solved by the invention] Conventional fluororesin-containing non-aqueous dispersion paints have the above-mentioned structure, so the transparency of the coating film is poor, and more importantly, the fluororesin-containing This had the problem of impairing high weather resistance.

[Means for Solving the Problems 1] The present invention has been made to solve the above-mentioned problems. and a fluorine-containing copolymer (B) that can be dissolved or stably dispersed in the above organic solvent alone.
The present invention provides a non-aqueous fluorine-containing copolymer dispersion characterized by containing the following.

In the present invention, the organic solvent can be freely selected from those commonly used as solvents for solution-type paints and those used as solvents for non-aqueous dispersion-type paints. Among these, aliphatic hydrocarbon solvents that are low in toxicity and photochemically inert are preferred; examples of the aliphatic hydrocarbon solvents include hexane, heptane, and octane.

Cyclohexane, cyclohebutane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane,
Examples include mineral spirits and aliphatic naphtha.

These organic solvents may be used alone or in combination of two or more, and aromatic hydrocarbons such as benzene, toluene, xylene, alcohol-based, ether-based,
Ester and ketone solvents, such as isopropyl alcohol, n-butyl alcohol, i-butyl alcohol, octyl alcohol, cellosolve, butyl cellosolve, diethylene glycol monobutyl ether, methyl isobutyl ketone, diisobutyl ketone, ethyl acyl ketone, methyl hexyl getone, ethyl butyl ketone . Ethyl acetate, isobutyl acetate, acyl acetate, 2-ethylhexyl acetate, etc. may be mixed and used to adjust solubility.

In the present invention, the fluorine-containing copolymer (B) obtained by independently dissolving or stably dispersing in the organic solvent has a solubility coefficient (hereinafter referred to as SP value) difference c or less with respect to the organic solvent, ΔSP A value of about 1.8 or less is preferably employed. In addition, fluorine-containing copolymers (
As B), those having film-forming properties by themselves are preferably employed. The specific value is the intrinsic viscosity (hereinafter referred to as [ηJ) measured at 30°C in tetrahydrofuran.
However, one of about 0.01 to 4.0 dl/g is preferably employed. Further, the fluorine-containing copolymer (B) may have a functional group that can react with a curing agent or itself to form a three-dimensional network structure.

In addition, as a fluorine-containing copolymer (A) that does not stably disperse in the organic solvent alone, ΔS
Those having a P value larger than about 1.8 are preferably employed. Furthermore, it is desirable that the fluorine-containing copolymer (A) has a molecular weight that makes it solid at room temperature. Furthermore, the fluorine-containing copolymer (A) and the fluorine-containing copolymer (B) may be chemically bonded.

The non-aqueous fluorine-containing copolymer dispersion of the present invention can be produced by the following method.

In an organic solvent, in the presence of a fluorine-containing copolymer (B) that can be dissolved or stably dispersed in this organic solvent, the monomer is soluble in the organic solvent, and the resulting polymer is dissolved in the organic solvent alone. In this case, monomers that cannot be stably released are polymerized. However, the monomer contains a fluorine-containing monomer.

Here, as the organic solvent, the above-mentioned organic solvents can be employed. Further, as the fluorine-containing copolymer (B), one having a ΔSP value of 1.8 or less with respect to an organic solvent is preferably employed, as described above. Specifically, a polymer in which a fluoroolefin is an essential component and a copolymerizable unsaturated monomer is polymerized is used. Examples of fluoroolefins include tetrafluoroethylene, chlorotrifluoroethylene,
Fluoroolefins having about 2 to 4 carbon atoms such as hexafluoropropylene are preferred and are employed. Examples of copolymerizable unsaturated monomers include vinyl ethers, vinyl esters, allyl ethers, and allyl esters.

Olefin', haloolefin, acryloyl compound,
Examples include methacryloyl compounds, unsaturated carboxylic acids and esters thereof. Furthermore, one type or two or more types of copolymerizable unsaturated monomers are copolymerized. In addition, such unsaturated monomers include hydroxyalkyl vinyl ether, hydroxyalkyl allyl ether, glycidyl vinyl ether, glycidyl allyl ether,
It may contain an unsaturated monomer having a reactive group such as a vinyl compound containing a hydrolyzable silyl group.The unsaturated monomer is used for purposes such as adjusting solubility depending on the type of organic solvent. can be selected as appropriate. In addition, when the produced non-aqueous fluorine-containing copolymer dispersion is used as a paint base, from the viewpoint of gloss, pigment dispersibility, coating film properties, etc.
Preferably, vinyl ether, vinyl ester, allyl ether or allyl ester is contained as a copolymerization component. In particular, ethyl vinyl ether, isobutyl vinyl ether, n-butyl vinyl ether.

Contains a linear monobranched or alicyclic alkyl group with a carbon*ei of about 15, such as cyclo△, xyl vinyl ether, vinyl acetate, n-butyric acid vinyl ester, n-butyl allyl ester, valeric acid allyl ester, etc. Vinyl ether, vinyl ester, allyl ether, and allyl ester are preferably employed. In addition, if the fluorine-containing copolymer based on monomer J] has insufficient solubility in the organic solvent used, copolymerization or graft polymerization of a macromonomer that provides a side chain to improve solubility may be used. For example, when using aliphatic hydrocarbons in which fluorine-containing copolymers are difficult to dissolve, it is preferable to improve their solubility in organic solvents by It is preferable to graft, block or macromonomerize and copolymerize.

The acrylic copolymer is preferably composed of the following monomers.

■Vinyl compounds: Vinyl compounds such as styrene, vinyltoluene, α-methylstyrene, vinyl acetate, acrylonitrile, and methacrylonitrile; ■(Cyclo)alkyl (meth)acrylates: Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate,
n-butyl methacrylate, i-butyl acrylate,
i-Butyl methacrylate + tert, -butyl acrylate, tert-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-U, tylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl Alkyl or cycloalkyl esters having 1 to 24 carbon atoms of acrylic acid or methacrylic acid such as methacrylate; ■Hydroxy (meth)acrylate: 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxy Hydroxyalkyl esters of acrylic acid or methacrylic acid having 1 to 24 carbon atoms, such as propyl methacrylate; ■α, β-ethylenically unsaturated, force-saturated carboxylic acid, diacrylic acid, acrylic acid, itaconic acid, crotonic acid, etc. a, β like
- Ethylenically unsaturated carboxylic acid; Acrylic copolymer can be obtained by copolymerizing using monomers selected from the above Φ to It is necessary to contain 5% to 40%, preferably 10% to 25%, and 0.5% to 5%, preferably 1% to 4%, of α,β-unsaturated carboxylic acids such as (2).

Furthermore, the most suitable example of the polyester that can be used in the present invention is poly(12-hydroxystearic acid), which is described in Tadahiro Miba's "Chemistry of Synthetic Resins", p. 251 (1968), Gihodo. It is obtained by heating and dehydrating 12-hydroxystearic acid, and the reaction formula is expressed as shown in the following formula (I).

nCHs(CHt)*CH-(CHt) to-COO
HOH This dehydration condensation reaction can be carried out using known catalysts such as phosphoric acid, 1)
- in the presence of toluenesulfonic acid, tetra-n-butyl titanate, tetraisopropyl titanate, etc., or Australian Patent No. 493.015 Specification No. 14
120 to 200°C, preferably 140 to 190°C (in the presence of methanesulfone, etc., or in the absence of a catalyst as described in Japanese Patent Publication No. 54-34009). It is carried out by removing the produced water from the system while heating to ℃, preferably by passing an inert gas such as nitrogen through the reaction system, or by performing the dehydration esterification reaction to form an azeotrope with water. It is advantageous to perform the esterification reaction in the presence of an aromatic hydrocarbon such as toluene or xylene, and remove the generated water azeotropically from the reaction system. It can be determined by measuring the amount of water and the acid value of the reactant.1 The polyester used in the present invention has an acid value of 2.
A value of 0 to 120 is practically suitable.

12-hydroxystearic acid, which is usually commercially available, is produced by hydrolysis of hydrogenated castor oil.
Although it contains small amounts of palmitic acid and stearic acid as impurities, the presence of these does not pose a particular problem as a raw material for producing the dispersant of the present invention.

The fluorine-containing copolymer (A) in the present invention is.

Copolymers of the same monomers as those mentioned in the description of the fluorine-containing copolymer (B) are employed. However, the fluorine-containing copolymer (A) cannot be stably dispersed in the organic solvent used alone. Specifically, the fluorine-containing copolymer (A) preferably has a difference in SP value of more than 1.8 from the organic solvent used, and is one that can be stably dispersed alone in the organic solvent used. This method is not preferable because a dispersed state cannot be obtained and the advantages of a single dispersion rather than a solution cannot be achieved.Furthermore, as a method for adjusting the solubility of the fluorine-containing copolymer (A) in an organic solvent, Examples of methods include selecting the type and proportion of monomers as appropriate.

Further, in the non-aqueous dispersion of the present invention, the monomer is soluble in a specific solvent in the presence of a fluorine-containing copolymer (B) that can be dissolved or stably dispersed in the organic solvent alone. and
A method is employed in which the resulting polymer polymerizes a monomer that cannot be stably dispersed by itself in an organic solvent, and the monomer contains a fluorine-containing copolymer. Such polymerization can be initiated by the presence of a polymerization initiation source. Examples of such a polymerization initiation source include a polymerization initiator and ionizing radiation. Among them, radical polymerization initiators are preferably employed. Such a polymerization initiator may be added all at once, or may be added in portions or continuously during one polymerization. In addition, the amount of monomer charged is
It is appropriately selected in consideration of the physical properties of the target polymer and the polymerizability of the monomer. Also.

The monomers may be added all at once before polymerization, or may be added in portions or continuously during polymerization. Particularly when the monomer is in a gaseous state, the pressure in the polymerization system decreases during polymerization, which may reduce the polymerization rate. It is preferable to keep the monomer constant. Also, when adding monomers after the start of polymerization, the composition of the monomers added later may be different from the composition at the time of initial charging. By changing the composition of the polymer from the initial feed composition, new properties can sometimes be added to the polymer.

The non-aqueous dispersion of the present invention can be used alone as a coating material, but it may also be used as a coating composition by adding various additives. Examples of such additives include curing agents, curing catalysts, and colorants such as pigments. , light stabilizers, ultraviolet absorbers, anti-gelling agents, leveling agents and the like. Examples of curing agents include incyanate curing agents, block isocyanate curing agents,
Examples include aminoblast. Such curing agents vary depending on the type of object to be coated, required physical properties of the coating film, coating conditions, etc.
It can be selected as appropriate.

The non-aqueous dispersion of the present invention can be used alone or in combination with the above-mentioned additives as a coating material. This paint can be applied to both organic and inorganic base materials.

Such base materials include synthetic resins, fiber reinforced resins, rubber,
Examples include metal, glass, and cement-based base materials such as stone.These base materials may be coated directly, or they may be coated with another paint, that is, in the form of a top coat. 6. Articles that may be coated with the coating composition containing the non-aqueous dispersion of the present invention as a main component have excellent weather resistance and are therefore useful as exterior materials or bridge materials. Moreover, painting may be performed in a factory or on-site. Furthermore, it may be carried out as a repair on the old paint film. In addition to the above-mentioned effects, the articles coated with the coating composition containing the non-aqueous dispersion as a main component of the present invention can be applied to the substrate without impairing the texture of the substrate, based on the transparency of the non-aqueous dispersion. and the color tone of the base coat is not impaired.
It has excellent cosmetic properties. Furthermore, since the coating composition containing the non-aqueous dispersion of the present invention as a main component has excellent thick coating properties, the resulting coating film also exhibits excellent performance as a coating film.

[Example 1 Example 1 Synthesis of non-aqueous dispersion A In a single crepe with an internal volume of 200 all equipped with a stainless steel stirrer, 33 parts of chlorotrifluoroethylene, 17 parts of ethyl vinyl ether, 6.5 parts of hydroxybutyl vinyl ether, N-vinylpyrrolidone 6.5 parts, azobisisobutyronitrile 0.2 parts, anhydrous potassium carbonate 2.6 parts
72 parts of mineral spirit (SP value 8.fl) and a dispersion stabilizer (manufactured by Asahi Glass Co., Ltd. [Lumiflon LF 200
Part weight average molecular weight approx. 50.0QO (SP value 9.8)
), cooled with liquid nitrogen, removed dissolved oxygen by solidification and degassing, and then reacted at 65° C. for 10 hours. The obtained polymer was milky white and had a non-volatile content of 47.
A stable dispersion with a 5% viscosity of 430 cps (E-type viscometer) and a particle size (as measured by a light scattering particle size meter) of dispersed particles (SP value 10.1 alone) of 0.3 μL at room temperature. No sedimentation was observed even after being left for several months. Moreover, the coating film was transparent.

Example 2 Synthesis of Graft Polymer 1 for Dispersion Stabilizer 1.5 parts of azobisisobutyronitrile and 100 parts of xylene were charged into a flask, 300 parts of n-butyl methacrylate, 1.5 parts of azobisisobutyronitrile, and mercapto. A mixed solution of 7.1 parts of acetic acid and 70 parts of xylene was added dropwise at 80°C over 3 hours to obtain a bu[noborimer] with a carboxyl group introduced at the end (weight average molecular weight 5.000, acid value 10.3B KO).
I/g.

An SP value of 9.5) was obtained. Furthermore, 43 parts of glycidyl vinyl ether, 6.4 parts of dimethyl laurelamine,
Yes! : 0.6 part of quinone was added and heated under reflux for 4 hours to introduce a copolymerizable double bond to the end of the prepolymer to form a macromonomer.

Furthermore, 36 parts of this macromonomer, 19.5 parts of chlorotrifluoroethylene, and 8.0 parts of cyclohexyl vinyl ether were added.
4 parts of ethyl vinyl ether, 4.8 parts of hydroxybutyl vinyl ether, 3.5 parts of hydroxybutyl vinyl ether, 0.2 parts of azobisisobutyronitrile, 0.7 parts of anhydrous potassium carbonate, and 72 parts of xylene in a stainless steel autoclave with a stirrer (inner volume 2001
1) and reacted for 8 hours at 65°C after freezing and degassing.
Graft polymer i, cSP value 9.6) was obtained.

Synthesis of non-aqueous dispersion B In a stainless steel autoclave with an internal volume of 200+nl and equipped with a stirrer, 40 parts of chlorotrifluoroethylene, 14.6 parts of ethyl vinyl ether, 7.5 parts of hydroxybutyl vinyl ether, 7.5 parts of N-vinylpyrrolidone, 0.2 parts of azobisisobutyronitrile, 2.6 parts of anhydrous potassium carbonate, 118.6 parts of mineral spirit (SP value 8.0), and 22 parts of the above-mentioned graft polymer for dispersion stabilizer were charged, and freeze-degassed 1ft at 65°C. The reaction was carried out for 10 hours.

The resulting polymer was milky white with a non-volatile content of 48% and a viscosity of 3.
30 cps, the dispersed particles (SP value alone: 10.1) were stable dispersions with a particle size of 0.3 μ-, and no sedimentation was observed even after being left at room temperature for 3 months. Moreover, the coating film was transparent.

Example 3 Synthesis of non-aqueous dispersion C 34.5 parts of tetrafluoroethylene, 14.6 parts of ethyl vinyl ether, 7.5 parts of hydroxybutyl vinyl ether, and 7 parts of N-vinylpyrrolidone were placed in a stainless steel autoclave with an internal volume of 200 ml and equipped with a stirrer. .5 parts, azobisisobutyronitrile 0.2 parts, anhydrous potassium carbonate 2.6 parts,
6 parts of mineral spirit (SP value 8.0) H and 22 parts of a graft polymer for dispersion stabilizer were charged, and after freezing and degassing, a reaction was carried out at 65°C for 8 hours.

The resulting polymer was milky white with a non-volatile content of 48% and a viscosity of 34.
0 cps, a stable dispersion of dispersed particles (SP value alone of 10, 0) with a particle size of 0.3 μm was allowed to stand for 3 months, but no sedimentation was observed2.Also, the coating film was transparent. Ta.

Comparative Example A mixed solvent consisting of 102 parts of heptane and 8 parts of n-butyl acetate (SP value 8.0), a dispersion stabilizer (Lumiflon L)
F200: SP value 9.11) 108 parts were placed in a flask and heated to reflux, followed by 15 parts of styrene, 40 parts of methyl methacrylate, 30 parts of acrylonidonol, 15 parts of 2-hydroxyethyl methacrylate, and tert-butyl peroxy 2-ethylhexanoate. Add 1.5 parts of the mixture to 3
It was added dropwise over a period of time, and after stirring for 2 hours, 26% of n-butyl acetate was added.
Added part.

The obtained polymer is milky white, contains 50% non-volatile components, and has a viscosity of 1.
A stable dispersion containing 10 cps and a particle size of 0.2 parts of dispersed particles (SP value io, l) showed no sedimentation even after being left at room temperature for 3 months. The coating film was cloudy and translucent.

An isocyanate curing agent (manufactured by Nippon Bo II Urethane Co., Ltd. [Coronate Yo HJ) was added to the dispersions obtained in Examples and Comparative Examples at a ratio of 10/(NCOI = 1/!) to form a coating film. The results of the transparency and weather resistance tests are shown in Table 14.

〔Effect of the invention〕

The non-aqueous fluorine-containing copolymer dispersion of the present invention has excellent stability and can provide a coating film with excellent weather resistance and transparency. Furthermore, articles coated with a paint containing this fluorine-containing non-aqueous dispersion as a main component have excellent cosmetic properties and weather resistance.

Representative group member (benbi) ] Toishi Toshiko

Claims (1)

[Scope of Claims] 1. An organic solvent, a fluorine-containing copolymer (A) that cannot be stably dispersed in the organic solvent alone, and a fluorine-containing copolymer that can be dissolved or stably dispersed in the organic solvent alone. (B
) A non-aqueous dispersion of a fluorine-containing copolymer. 2. Fluorine-containing copolymer (A) is fluorine-containing copolymer (B)
The fluorine-containing copolymer non-aqueous dispersion according to claim 1, which is dispersed by. 3. SP value of organic solvent and S of fluorine-containing copolymer (A)
The difference in P value is greater than 1.8, and the fluorine-containing copolymer (B
2. The non-aqueous decomposition liquid of a fluorine-containing copolymer according to claim 1, wherein the difference in SP value between the two is 1.8 or less. 4. Fluorine-containing copolymer (A) and fluorine-containing copolymer (
The non-aqueous dispersion according to claim 1, wherein at least one of B) has a reactive group. 5. In an organic solvent, in the presence of a fluorine-containing copolymer (B) that is dissolved or stably dispersed in this organic solvent, the obtained fluorine-containing copolymer (A) is stable in the above organic solvent alone. 1. A method for producing a non-aqueous dispersion of a fluorine-containing copolymer, which comprises polymerizing monomers that form a polymer that cannot be dispersed in a fluorine-containing copolymer. 6. Organic solvent, including a graft combination of a fluorine-containing copolymer that cannot be stably dispersed in this organic solvent alone and a fluorine-containing copolymer that can be dissolved or stably dispersed in this organic solvent alone. Characteristic non-aqueous dispersion of fluorine-containing copolymer. 7. In an organic solvent, in the presence of a fluorine-containing copolymer (A') that is dissolved or stably dispersed in this organic solvent and has a group capable of graft bonding, the obtained fluorine-containing copolymer is dissolved alone. A non-aqueous dispersion of a fluorine-containing copolymer characterized by polymerizing a monomer that cannot be stably dispersed in the above-mentioned organic solvent and can form a graft bond with the fluorine-containing copolymer (A'). Method of manufacturing liquid. 8. A paint containing the non-aqueous fluorine-containing copolymer dispersion according to any one of claims 1 and 6 as a main component. 9. A coated article coated with a paint containing the fluorine-containing copolymer non-aqueous dispersion according to any one of claims 1 and 6 as a main component.