JP3257288B2 - Aqueous dispersion of fluorine-containing polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous dispersion of a fluorine-containing polymer.

More specifically, it is a fluorine-containing polymer aqueous dispersion containing an organosilicon compound together with colloidal silica, and can be suitably used for various coatings.

[0003]

2. Description of the Related Art Various aqueous dispersions have been proposed in the field of paints and the like. For example, JP-A-3-778
JP-A No. 4 describes an aqueous dispersion obtained by polymerizing an acrylic or other monomer in the presence of vinylidene fluoride-based polymer particles, but is satisfactory in terms of adhesion to various substrates and the like. It has not been. In addition, for example, Japanese Patent Publication No. 2-20656 describes an aqueous dispersion comprising polyvinylidene fluoride and fumed silica, the weather resistance as a top coating composition,
The long-term durability has not been improved.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a method of combining a specific fluorinated polymer and an organosilicon compound together with colloidal silica to form a coating composition, It is an object to obtain an aqueous dispersion of a fluorinated polymer having excellent weather resistance.

[0005]

The present invention relates to a fluorine-containing seed polymer obtained by seed-polymerizing a monomer having a reactive α, β-unsaturated group in the presence of fluorine-containing polymer particles. Colloidal silica and an organosilicon compound are blended in an aqueous dispersion of a certain fluorinated polymer, and the mixing ratio of the solid content of the colloidal silica is 1 to 100 parts by weight of the solid content of the fluorinated polymer aqueous dispersion. To 50 parts by weight, wherein the mixing ratio of colloidal silica and the organosilicon compound is from 5:95 to 75:25 by weight%.

[0006] The present invention also provides a fluorine-containing seed polymer in an aqueous dispersion of a fluorine-containing polymer containing the above-mentioned colloidal silica and an organosilicon compound, which reacts in the presence of particles of the fluorine-containing polymer and colloidal silica. Sex α,
A fluorine-containing seed polymer obtained by seed-polymerizing a monomer having a β-unsaturated group, wherein 0.1 to 50% by weight of the monomer having a reactive α, β-unsaturated group is contained. Reactivity α,
It is preferably an organosilicon compound having a β-unsaturated group.

In the present invention, the monomer having a reactive α, β-unsaturated group is preferably an acrylate and / or a methacrylate.

In the present invention, the fluoropolymer preferably contains 70 to 95 mol% of vinylidene fluoride and 5 to 30 mol% of chlorotrifluoroethylene.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the purpose of blending colloidal silica with an aqueous dispersion of a fluorinated polymer is to form various kinds of materials such as lightweight concrete, mortar, calcium silicate plate, slate, glass or stainless steel when formed into a paint. An object of the present invention is to further improve the adhesion to an inorganic substrate and the adhesion to an organic substrate such as an acrylic resin, a PVC resin, a polyurethane resin, and a chloroprene resin.

As the colloidal silica in the present invention, for example, sodium removal from water glass (ion exchange method,
(Acid decomposition method, peptization method), and has a primary particle diameter of 4 to 150 nm, preferably 5 to 50 nm.
In, this is usually supplied as an aqueous dispersion,
You can use it as is.

The above-mentioned colloidal silica can be used whether it is on the acidic side or on the basic side in a water-dispersible state. Examples of the acidic-side colloidal silica include Snowtex-O or Snowtex- trade name. Unstabilized silica (pH 2 to 4) commercially available as OL (manufactured by Nissan Chemical Industries, Ltd.) can be used. On the other hand, as the basic colloidal silica, a small amount of alkali metal ions,
Silica stabilized by addition of aluminum ion, ammonium ion or amine (pH 8.4-10)
For example, trade names Snowtex 20, Snowtex C, Snowtex N (all manufactured by Nissan Chemical Industries, Ltd.), trade names Ludox HS-40, HS-3
0, LS, SM-30, TM, AS, AM (the above are manufactured by DuPont, USA), trade name Nalcoque (manufactured by Nalco Chemical Co., USA), trade name Mittens (manufactured by Monsanto Chemical Co., USA), etc. You can give what you have. When the pH is 6 to 8, not only the stability of the colloidal silica but also the stability of the coating when formed into a coating is reduced, and there is a tendency for aggregation and gelation.

In the present invention, an organosilicon compound can be used together with the above-mentioned colloidal silica, and the purpose thereof is to provide a coating material which has good adhesion to the above-mentioned inorganic and organic substrates, weather resistance and chemical resistance. Another object of the present invention is to further improve flexibility in addition to film forming properties. As the organosilicon compound, a compound represented by the general formula (I):

[0013]

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Wherein R ¹ represents a non-hydrolyzable group or a hydrogen atom, R ² represents an alkyl group, an aryl group, an alkenyl group or a hydrogen atom, and a represents 0, 1 or 2. Monomer.

In the formula (I), examples of the non-hydrolyzable group include an alkyl group such as methyl, ethyl and propyl; an aryl group such as phenyl, tolyl and mesityl; and an alkenyl such as vinyl and allyl. Group, γ
Haloalkyl groups such as -chloropropyl group, aminoalkyl groups such as γ-aminopropyl group, γ- (2-aminoethyl) aminopropyl group, γ-glycidoxypropyl group, β- (3,4-epoxycyclohexyl) Examples thereof include an epoxyalkyl group such as an ethyl group, a methacryloyloxyalkyl group such as a γ-mercaptoalkyl group, a γ-methacryloyloxypropyl group, and a hydroxyalkyl group such as a γ-hydroxypropyl group. Among these substituents, preferred for the present invention are an alkyl group having 8 or less carbon atoms, more preferably an alkyl group having 4 or less carbon atoms, and Is a phenyl group which is a kind of an aminoalkyl group, an epoxyalkyl group, a methacryloyloxyalkyl group, a hydroxyalkyl group and an aryl group, and an alkenyl group having 2 to 3 carbon atoms. Also, R ²
The alkyl group, the aryl group and the alkenyl group of the above are the same as the above-mentioned R ^1, and particularly preferred are alkyl groups having 4 or less carbon atoms, since the reactivity decreases when the substituent has a large number of carbon atoms. is there.

Specific examples of the general formula (I) include, for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane,
Vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) aminopropyltrimethoxysilane, γ-glycidoxy Propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-hydroxypropyltrimethoxysilane, and the like, Methyltrimethoxysilane, phenyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and the like are preferable in terms of reactivity, film formability, flexibility, and the like.

The aqueous fluorine-containing polymer dispersion of the present invention is defined as an aqueous dispersion of a fluorine-containing polymer in which particles of a specific fluorine-containing polymer are dispersed, comprising colloidal silica or an organosilicon compound together with colloidal silica. It has been blended.

The specific fluorinated polymer is a specific fluorinated seed polymer obtained by polymerizing a monomer having a reactive α, β-unsaturated group in the presence of a fluorinated polymer. is there.

The fluorine-containing polymer is a fluoroolefin polymer or a polymer obtained by copolymerizing a fluoroolefin with a monomer copolymerizable with the fluoroolefin.

Examples of the fluoroolefin include vinyl fluoride, vinylidene fluoride (VdF),
Fluoroolefins having about 2 to 4 carbon atoms such as tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene, and pentafluoropropylene are preferably employed. In terms of VdF, T
FE, CTFE, HFP are preferred.

Examples of the monomer copolymerizable with the fluoroolefin include cyclohexyl vinyl ether (CHVE), ethyl vinyl ether (EVE),
Alkyl vinyl ethers such as butter vinyl ether and methyl vinyl ether; alkenyl vinyl ethers such as polyoxyethylene allyl ether (POEAE) and ethyl allyl ether; vinyl trimethoxysilane (V
Organic silicon compounds having a reactive α, β-unsaturated group such as Si), vinyltriethoxysilane, vinyltris (methoxyethoxy) silane, acrylates such as methyl acrylate and ethyl acrylate, methyl methacrylate, methacryl Examples include methacrylic acid esters such as ethyl acrylate, vinyl acetate, vinyl benzoate, and vinyl esters such as "VEOBA" (vinyl ester manufactured by Shell). To alkyl vinyl ethers, allyl vinyl ethers, and organosilicon compounds having a reactive α, β-unsaturated group are preferred, and CHVE, EVE, POEAE, and VSi are more preferred.

Examples of the monomer having a reactive α, β-unsaturated group include acrylates such as methyl acrylate, butyl acrylate (BA), ethyl acrylate and 2-ethylhexyl acrylate, and methacrylic acid. Organics having a reactive α, β-unsaturated group such as methyl (MMA), methacrylate such as butyl methacrylate, polyoxyethylene methacrylate (POEMA), and γ-methacryloyloxypropyl-trimethoxysilane (SiMA). Silicon compound, vinyl acetate, vinyl benzoate, "Veoba" (vinyl ester manufactured by Shell)
And vinyl esters such as styrene, and aromatic vinyl compounds such as p-tert-butyl-styrene. Among them, acrylic ester, methacrylic ester, reactive α, β- Organic silicon compounds having an unsaturated group, vinyl esters are preferred,
BA, MMA, POEMA and SiMA are more preferred.

In addition, by using an excessive amount of an organosilicon compound having a reactive α, β-unsaturated group during the above polymerization or copolymerization, the same effect as when the organosilicon compound is blended after polymerization or copolymerization can be obtained. The effect is obtained.

The solid concentration of the aqueous fluoropolymer dispersion of the present invention is, for example, 30 to 60% (% by weight, the same applies hereinafter), preferably 35 to 55%. If it is less than 30%, it tends to be difficult to adjust the viscosity at the time of coating, and if it exceeds 60%, the storage stability of the dispersion tends to decrease.

The particle diameter of the fluorinated polymer particles in the fluorinated polymer aqueous dispersion is, for example, 50 to 2
50 nm, preferably 80-200 nm,
When the particle size is less than 50 nm, the viscosity of the aqueous dispersion tends to increase, and a high-concentration aqueous dispersion tends not to be obtained.
When it exceeds 0 nm, the particles tend to settle and coagulate during storage of the aqueous dispersion.

The blending ratio of the colloidal silica in the present invention is, for example, 1 to 50 parts by weight of solids of colloidal silica with respect to 100 parts by weight of solids of a fluoropolymer-based aqueous dispersion (parts by weight, hereinafter the same). , Preferably 5
When the mixing ratio is less than 1 part, the surface hardness and adhesion tend not to be obtained. When the mixing ratio is more than 50 parts, the film formability of the coating film is not sufficient and the gloss tends to be further reduced. .

In the present invention, an organosilicon compound can be used together with the colloidal silica. In this case, the mixing ratio (solid content) (%) of the two is 5:95.
75:25, preferably 20:80 to 60: 4
0. If the amount of colloidal silica is less than 5%, the flexibility of the formed coating film tends to be insufficient, and if it exceeds 75%, the flexibility and film formability of the formed coating film are not sufficient and cracks tend to occur.

The proportion of the organosilicon compound having a reactive α, β-unsaturated group used in the present invention may be 0.1% of the monomer having a reactive α, β-unsaturated group.
５０50%, preferably 1-30%, and more preferably 2-20%. When the use ratio is less than 0.1%, the flexibility of the formed coating film tends to be insufficient, and 50%
If it exceeds 300, the film-forming property of the coating film is not sufficient, and cracks tend to easily occur.

In the present invention, the fluoropolymer includes:
The VdF is 70 to 95 mol%, preferably 75 to 90 mol%.
Mol%, more preferably 75 to 85 mol%, and 30 to 5 mol%, preferably 25 to 10 mol%, more preferably 25 to 15 mol% of the CTFE.

If the VdF is less than 70 mol%, the compatibility between the seed particles and the acrylic and / or methacrylic copolymer is reduced, and the transparency and mechanical properties of the film obtained by drying the aqueous dispersion are reduced. When the CTFE is less than 5 mol%, the compatibility between the seed particles and the acrylate and / or methacrylate esters is poor, so that the swelling of these monomers into the particles during the seed polymerization may occur. It is not performed promptly, and the cast film from the emulsion has poor transparency, and gloss tends not to be obtained even when a coating film is prepared from a paint.

In order to obtain the fluorine-containing polymer aqueous dispersion of the present invention, it may be produced, for example, by the following method.

(1) Water and an emulsifier are charged into a reaction vessel, and nitrogen injection and degassing are repeated. Then, a fluoroolefin monomer is injected, and if necessary, a monomer copolymerizable with the fluoroolefin is added, followed by polymerization. Charge the initiator,
After elapse of a predetermined time while maintaining the pressure in the container constant, at room temperature,
After returning to normal pressure, an aqueous dispersion of a fluorinated polymer containing particles of the fluorinated polymer is obtained, and (2) the dispersion containing the particles of the fluorinated polymer is heated to a predetermined temperature. After warming, an emulsion of the monomer having a reactive α, β-unsaturated group was gradually charged, and a polymerization initiator was added to start seed polymerization. After a predetermined time had elapsed, the temperature was returned to normal temperature and normal pressure. A method for obtaining an aqueous dispersion of a fluorinated polymer of the present invention containing particles of a fluorinated seed polymer by neutralization.

The colloidal silker and the organosilicon compound may be present in the above steps (1) and / or (2), or may be added separately or additionally after the completion of step (2).

Next, the present invention will be described more specifically based on synthesis examples and experimental examples, but the present invention is not limited only to these.

Synthesis Example 1 A pressure-resistant reaction vessel equipped with a stirrer having an internal capacity of 1 liter was charged with 500 ml of deionized water, 0.5 g of ammonium perfluorooctanoate, and 0.05 g of polyoxyethylene monostearate (POE40). After repeated injection and deaeration to remove dissolved air, VdF / TFE /
The mixture was pressurized to 10 kgf / cm ² at 60 ° C. with a mixed monomer having a 74/14/12 mol% ratio of CTFE. Next, 0.2 g of ammonium persulfate was charged, and VdF / TFE was adjusted so that the pressure in the tank was constant at 10 kgf / cm ^2.
After continuously supplying a mixed monomer having a ratio of 74/14/12 mol% of / CTFE and reacting for 30 hours, the inside of the tank was returned to normal temperature and normal pressure to obtain an aqueous dispersion of a fluoropolymer of Synthesis Example 1. .

Synthesis Example 2 500 ml of deionized water, 0.5 g of ammonium perfluorooctanoate, 0.05 g of polyoxyethylene monostearate (POE40), 20 g of a 20 wt% aqueous solution were placed in a pressure-resistant reaction vessel with a stirrer having a content of 1 liter. An aqueous fluoropolymer dispersion was obtained in the same manner as in Synthesis Example 1 except that 50 g of colloidal silica was charged.

Synthesis Examples 3 and 4 Except that the supplied monomers were changed to the compositions shown in Table 1,
In the same manner as in Synthesis Example 1, the fluoropolymer aqueous dispersions of Synthesis Examples 3 and 4 were obtained.

Synthesis Example 5 In a 200 ml stainless steel autoclave equipped with a stirrer, 14.2 g of cyclohexyl vinyl ether (CHVE) having the composition shown in Table 1 and polyoxyethylene allyl ether (POEAE) (trade name P, manufactured by NOF Corporation)
KA5003) 4.2 g, ethyl vinyl ether (EV
E) 8.1 g, ion-exchanged water 66.1 g, ammonium perfluorooctanoate (emulsifier) 0.35 g, potassium carbonate (K ₂ CO ₃ ) 0.35 g, sodium bisulfite (NaHSO ₃ ) 0.02 g, ammonium persulfate (Initiator) 0.08 g was charged, cooled with ice, and pressurized with nitrogen gas to 3.5 kg / cm ² to degas. After repeating this pressurized degassing twice, degassing to 10 mmHg to remove dissolved oxygen, 27.5 g of chlorotrifluoroethylene (CTFE) was charged and reacted at 30 ° C. for 12 hours. An aqueous dispersion of a fluoropolymer was obtained.

Synthesis Example 6 In Synthesis Example 5, 11.6 g of cyclohexyl vinyl ether (CHVE) having the composition shown in Table 1 and polyoxyethylene allyl ether (POEAE) (Nippon Oil & Fats Co., Ltd.) were placed in a 200 ml autoclave with a stainless steel stirrer.
3.4 g, ethyl vinyl ether (EVE) 6.6 g, ion-exchanged water 26.1 g,
Ammonium perfluorooctanoate (emulsifier) 0.3
Synthesis was performed except that 5 g, potassium carbonate (K ₂ CO ₃ ) 0.35 g, sodium bisulfite (NaHSO ₃ ) 0.02 g, and ammonium persulfate (initiator) 0.08 g and 50 g of 20% aqueous colloidal silica were charged. A fluoropolymer aqueous dispersion of Synthesis Example 6 was obtained in the same manner as in Example 1.

Synthesis Example 7 An aqueous fluoropolymer dispersion of Synthesis Example 7 was obtained in the same manner as in Synthesis Example 5 except that the monomers of Synthesis Example 5 were changed to the monomer compositions shown in Table 1. In Table 1, VSi indicates vinyltrimethoxysilane.

Synthesis Example 8 A 200-ml four-necked flask equipped with a stirrer, a condenser, and a thermometer was charged with 100 g of the aqueous fluoropolymer dispersion obtained in Synthesis Example 1, and alkylallyl sulfo was added thereto. A succinate alkali salt (trade name Eleminor JS2, manufactured by Sanyo Chemical Industry Co., Ltd.) was added in an amount of 1.0% based on the solid content. The mixture was heated in a water bath with stirring, and when the tank temperature reached 80 ° C., methyl methacrylate (MM
A) 13.0 g, butyl acrylate (BA) 3.5 g,
2.2 g of a mixed monomer of polyoxyethylene methacrylate (POEMA), manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: M90G, was emulsified with a 0.5% aqueous solution of an alkyl allyl sulfosuccinate alkali salt. It was dropped over time. Immediately afterwards, 2% of ammonium persulfate
One milliliter of aqueous solution was added to disclose the reaction. After 3 hours from the start of the reaction, the temperature in the vessel was raised to 85 ° C., maintained for 1 hour, cooled, and adjusted to pH 7 with ammonia water.
The mixture was filtered through a 0-mesh wire net to obtain a blue-white aqueous dispersion of a fluorine-containing seed polymer.

Synthesis Example 9 The procedure of Synthesis Example 8 was repeated, except that 50 g of 20% aqueous colloidal silica was added to 100 g of the aqueous fluoropolymer dispersion obtained in Synthesis Example 1 in a flask. An aqueous dispersion of a fluorine seed polymer was obtained.

Synthesis Examples 10 to 14 Synthesis Example 10 was carried out in the same manner as in Synthesis Example 8 except that the compositions of the aqueous fluoropolymer dispersion, colloidal silica and acrylic monomer were changed as shown in Table 2. To 14 of a fluorine-containing seed polymer aqueous dispersion were obtained.

Synthesis Examples 15 to 16 The same procedure as in Synthesis Example 8 was carried out except that colloidal silica was used instead of using the aqueous fluoropolymer dispersion, and the aqueous acrylic resin dispersion of Synthesis Examples 15 to 16 was used. I got a body.

The following items were measured for the aqueous dispersions of Synthesis Examples 1 to 16.

Characteristics of Aqueous Dispersion Solid content: dried at 150 ° C. for 1 hour in a vacuum drier, and the weight after drying was expressed as a percentage of the weight of the aqueous dispersion before drying. Minimum film formation temperature (MFT): The minimum temperature at which a continuous film was formed was measured using a temperature gradient tester (manufactured by Riken Seiki Seisakusho). Particle size: Laser light scattering particle size measuring device (Otsuka Electronics DLS
-3000).

The results are shown in Tables 1 and 2.

[0048]

[Table 1]

[0049]

[Table 2]

Examples 1 to 16 Mechanical Properties of Clear Film Colloidal silica (Nissan Chemical Industries, Ltd.) as shown in Tables 3 and 4 with respect to 100 parts of solids of the aqueous dispersion obtained in Synthesis Examples 5 to 16 Made, trade name Snowtex C, S
iO ₂ content 20%, primary particle diameter 10 to 20 nm), organosilicon compound (brand name KBM, manufactured by Shin-Etsu Chemical Co., Ltd.)
After adding -503, component γ-methacryloxypropyltrimethoxysilane), a clear film was prepared and its mechanical properties (elongation and elastic modulus) were measured.

Mechanical properties: According to JIS-K6301.

Characteristics of White Coating Film The solid content of the aqueous dispersions obtained in Synthesis Examples 5 to 16 was 100%.
To the parts, colloidal silica and an organosilicon compound were added as shown in Tables 3 and 4, and titanium oxide (trade name: CR90, manufactured by Ishihara Sangyo Co., Ltd.) was added as a filler.
Parts, Disroll H-14N (manufactured by Nippon Emulsifier Co., Ltd.) as a dispersant, 2 parts of ethylene glycol as a deicing agent, and FS Antifoam 013B (Dow Corning) as an antifoaming agent, 0.5 part 0.5 parts of SN thickener A-818 (manufactured by San Nopco Co., Ltd.) as a viscosity agent, and Texanol (manufactured by Eastman Chemical Company) 1 as a film forming aid
0 parts were added and mixed well using a disper stirrer to prepare a paint.

The following items were measured for the obtained paint.

Initial Properties of White Coating Gloss: The obtained coating was spread on an aluminum plate using an applicator to a coating thickness of 40 μm, dried at room temperature for one week, and then measured with a gloss meter. The gloss was measured using (Suga Test Instruments Co., Ltd.). Pencil hardness: Measured according to the pencil hardness test of JISK5400. Adhesion: The obtained paint was applied on a slate plate using an airless spray gun so that the thickness of the coating film after drying was 40 μm. Similarly, a paint was applied on a slate plate coated with an acrylic resin-based aqueous emulsion type sealer, Movinyl 940 (Hoechst synthesis), using an airless spray gun so that the thickness of the coated film after drying was 40 μm. After drying the applied slate at room temperature for one week,
An adhesion test was performed in accordance with SK5400, and after the cellophane tape peeling test in 100 cells, the number of remaining cells was measured.

Characteristics of White Coated Film after Accelerated Weathering Test These coated plates were subjected to an accelerated weathering tester (I-Super UV
The gloss retention after a lapse of 1000 hours was measured in a tester (SUV-W13), manufactured by Iwasaki Electric Co., Ltd., and evaluated as follows.

Gloss: The gloss of the coating film applied to the aluminum substrate after the test was measured by the same method as described above. Adhesion: Adhesion on slate substrates directly coated and acrylic sealer coated slate plates was measured by the same method as described above.

The results are shown in Tables 3 and 4.

Among these experimental examples, experimental examples 8 to 11 correspond to the examples of the present invention.

[0059]

[Table 3]

[0060]

[Table 4]

[0061]

As is evident from the above results, the coating composition obtained by using the aqueous fluoropolymer-based dispersion of the present invention containing a specific fluoropolymer, colloidal silica and an organosilicon compound is obtained. The coating film is made of lightweight concrete, mortar, calcium silicate board, slate, etc. by incorporating colloidal silica, in addition to the features such as weather resistance, chemical resistance, film formability, and flexibility of the fluorine-containing polymer.
It has excellent adhesion to various inorganic substrates such as glass or stainless steel, and to organic substrates such as acrylic resins, PVC resins, polyurethane resins, and chloroprene resins.

Further, the coating film obtained by further blending an organosilicon compound has weather resistance, chemical resistance, film formability,
Excellent flexibility in addition to features such as adhesion to inorganic and organic substrates.

In particular, in the present invention, the presence of colloidal silica and an organosilicon compound at the time of seed polymerization can provide excellent effects on weather resistance, stain resistance, water resistance, flexibility and coating film hardness.

Continuation of the front page (72) Katsuhiko Imoto 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Yodogawa Works (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 127/12

Claims (4)

(57) [Claims] Claims: 1. Reactivity in the presence of fluoropolymer particles
Seed polymerization of monomer having α, β-unsaturated group
Colloidal silica and an organosilicon compound are compounded in an aqueous dispersion of a fluorinated polymer that is a fluorinated seed polymer, and the compounding ratio of the solid content of the colloidal silica is It is 1 to 50 parts by weight based on 100 parts by weight of the solid content of the dispersion, and the mixing ratio of the colloidal silica and the organosilicon compound is 5:95 to 75:
25. A fluorine-containing polymer aqueous dispersion which is 25. 2. The colloidal silica and the organosilicon
In a fluorine-containing polymer aqueous dispersion containing a compound
Of the fluorinated seed polymer is
Reactive α, β-unsaturated groups in the presence of silica and colloidal silica
Fluorine-containing sheet obtained by seed polymerization of a monomer having
A polymer having the reactive α, β-unsaturated group
0.1 to 50% by weight of the monomer is a reactive α, β-unsaturated group
The aqueous dispersion of a fluorinated polymer according to claim 1 , which is an organosilicon compound having the following formula: Wherein the reactive alpha, beta-monomers having an unsaturated group, fluorine-containing polymer aqueous dispersion of claim 1 or 2, wherein the acrylic acid ester and / or methacrylic acid ester. Wherein said fluorine-containing polymer, fluorine-containing heavy according to any one of claims 1 to 3, containing a vinylidene fluoride 70-95 mol% and chlorotrifluoroethylene 5-30 mole% Combined aqueous dispersion.