JPH0455441B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an aqueous polymer dispersion for coating. Furthermore, in detail, an ethylenically unsaturated monomer is emulsion polymerized in the presence of fluoropolymer particles in an aqueous medium, thereby retaining the excellent properties inherent to fluoropolymer while eliminating its drawbacks. This invention relates to an aqueous polymer dispersion for coating that has improved adhesion to hot substrates. [Prior Art] Fluorinated polymers not only exhibit excellent resistance to chemicals such as acids and alkalis and organic solvents, but also have good heat resistance, weather resistance, gas impermeability, and resistance. It has radioactivity and also has excellent mechanical properties. For this reason, fluorine-based polymers are used as lining materials, corrosion-resistant materials, porous materials such as asbestos sheets, glass sheets, felt sheets, impregnated processed materials such as paper, packing materials, coating materials, acid-resistant, alkali-resistant, and electrically resistant materials. It is attracting attention for its use in a variety of fields, including spraying on the surfaces of materials that require insulation, baking paints, laminated film materials, non-tackifying materials such as fibers, water repellents, and coating materials for flooring materials. There is. [Problems to be solved by the invention] However, although fluorine-based polymers have such excellent properties, when they are used as aqueous dispersions for coating, processability ( For example, the adhesion to the substrate) and durability are insufficient,
Further physical properties (e.g. tensile strength, 100%
Modulus) is also inferior. Moreover, its price is much higher than that of ordinary aqueous resin dispersions for coating, such as vinyl acetate emulsion, styrene-butadiene synthetic latex, and acrylic emulsion. For this reason, fluorine-based polymers have not yet come into widespread use in the fields mentioned above. [Means for Solving the Problems] The present invention aims to provide an aqueous polymer dispersion for coating that improves the above-mentioned drawbacks while retaining the excellent performance inherent to fluorine-based polymers. As a result of our studies, we found that the above objective can be achieved by emulsion polymerizing an ethylenically unsaturated monomer in an aqueous medium using a fluorine-based polymer as a seed polymer and in the presence of these fluorine-based polymer particles. After learning this, I was able to complete the present invention. Therefore, the present invention provides an ethylenically unsaturated monomer in an aqueous medium in an amount of 0.5 to 100 parts by weight of this monomer.
An aqueous polymer dispersion obtained by emulsion polymerization in the presence of 90 parts by weight of fluorine-based polymer particles, wherein the average particle size of the polymer particles in this aqueous polymer dispersion is
The present invention relates to an aqueous polymer dispersion for coating, characterized in that the particle size is 0.05 to 3 μm. The present invention will be explained in detail below. The fluorine-based polymer used as the seed polymer in the present invention is not particularly limited, and examples thereof include trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, trifluorochloroethylene, hexafluoropropylene, Homopolymers and copolymers of vinyl fluoride, hexafluoroisobutylene, perfluoroacrylic acid, and the like, or copolymers of these monomers and copolymerizable monomers can be used. Among these, tetrafluoroethylene-propylene copolymer,
Preferred are ethylene tetrafluoride-propylene hexafluoride copolymer, vinylidene fluoride polymer, ethylene tetrafluoride polymer, and the like. The fluoropolymer may be added in any state as long as it is dispersed as particles in an aqueous medium, but since it is usually produced and sold as an aqueous dispersion, it cannot be added as is as an aqueous dispersion. is convenient. Note that the particle size of the fluorine-based polymer particles is preferably in the range of about 0.03 to 1 μm in relation to the polymer particles in the aqueous polymer dispersion. The ethylenically unsaturated monomer to be emulsion polymerized in the presence of these fluorine-based polymer particles is an acrylic monomer, such as an ester of acrylic acid or methacrylic acid (alkanol having 1 to 1 carbon atoms).
12, such as methyl acrylate, ethyl acrylate, propyl acrylate, n-acrylate
Butyl, isobutyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-methacrylate
butyl, isobutyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate and lauryl methacrylate), conjugated dienes (e.g. 1,3-butadiene and isobutylene), aromatic vinyl compounds (e.g. styrene, α-methylstyrene) and halogenated styrenes), α,β-unsaturated carboxylic acids (e.g. methacrylic acid, acrylic acid, fumaric acid, maleic acid,
maleic anhydride, crotonic acid, and itaconic acid), vinyl acetate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-methylacrylamide, N-methylolmethacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate , glycidyl acrylate, glycidyl methacrylate, ethylene glycol dimethacrylate, divinylbenzene, and vinyl cyanide compounds (eg, acrylonitrile), which can be used alone or in combination of two or more. Of these,
Styrene, acrylic acid alkyl ester with alkyl group having 2 to 6 carbon atoms, butadiene, itaconic acid,
One or a combination of two or more of maleic acid, fumaric acid, acrylic acid, and methacrylic acid are suitable. The ethylenically unsaturated monomer is subjected to emulsion polymerization in the presence of 0.05 to 90 parts by weight, preferably 0.5 to 40 parts by weight, of fluoropolymer particles per 100 parts by weight of the monomer. If the fluorine-based polymer particles are less than 0.05 parts by weight per 100 parts by weight of the ethylenically unsaturated monomer, the resulting aqueous polymer will not have the chemical resistance properties of the fluorine-based polymer; If the amount exceeds 90 parts by weight, processability will be poor and undesirable. Although it is not clear what kind of product can be obtained by emulsion polymerization of ethylenically unsaturated monomers in the presence of fluorine polymers, ethylenically unsaturated monomers are mainly fluorine polymers. It is thought that it is absorbed or adsorbed into the polymer particles and polymerizes while causing the particles to swell. Emulsion polymerization of ethylenically unsaturated monomers can be carried out under conventional emulsion polymerization conditions. for example,
In the aqueous medium, emulsifiers, polymerization initiators, chain transfer agents, and in some cases chelating agents, PH regulators,
and a solvent, etc., at a temperature of about 30 to 90℃.
Carry out the reaction for about 30 hours. As emulsifiers, anionic, nonionic or anionic-nonionic combinations can be used, and in some cases amphoteric surfactants can be used. As the anionic emulsifier, higher alcohol sulfuric acid ester, alkylbenzene sulfonic acid sodium salt, succinic acid dialkyl ester sulfonic acid sodium salt, alkyl diphenyl ether disulfonic acid sodium salt, etc. are used. Among these, dodecylbenzenesulfonic acid sodium salt and lauryl sulfate sodium salt are preferred. Examples of the nonionic emulsifier include polyoxyethylene alkyl ether and polyoxyethylene alkylaryl ether. Most commonly polyoxyethylene nonyl phenyl ether is used. As the amphoteric emulsifier, lauryl betaine and the like are suitable. Also, copolymerizable with ethylenically unsaturated monomers,
So-called reactive emulsifiers, such as sodium styrene sulfonate and sodium allylalkyl sulfosuccinate, may also be used as emulsifiers.
The amount of emulsifier used is usually an ethylenically unsaturated monomer.
The amount is approximately 0.05 to 5.0 parts by weight per 100 parts by weight. As a polymerization initiator, water-soluble persulfates, hydrogen peroxide, etc. can be used, and in some cases,
Can be used in combination with reducing agents. Examples of the reducing agent include sodium pyrobisulfite, sodium hydrogensulfite, L-ascorbic acid, and sodium formaldehyde sulfoxylate. Additionally, oil-soluble polymerization initiators such as 2,2'-azobisisobutyronitrile, 2,
2'-azobis-(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis-2,4
-dimethylvaleronitrile, 1,1'-azobis-
Cyclohexane, 1-carbonitrile, benzoyl peroxide, dibutyl peroxide, cumene hydroperoxide, etc. can be dissolved in the ethylenically unsaturated monomer and used in combination. Preferred examples include yumene hydroperoxide, isopropylbenzene hydroperoxide, paramenthane hydroperoxide, azobisisobutyronitrile, and benzoyl peroxide. The amount of the polymerization initiator used is approximately 0.1 to 3.0 parts by weight per 100 parts by weight of the ethylenically unsaturated monomer. Chain transfer agents include halogenated hydrocarbons (e.g. carbon tetrachloride, chloroform, and bromoform), mercaptans (e.g. n-dodecylmercaptan, t-dodecylmercaptan and n-octylmercaptan), xanthogens (e.g. dimethyl xanthogen disulfide,
and diisopropylxanthogen disulfide) terpenes (eg, dipentene, terpinolene), and the like. Generally, halogenated hydrocarbons (eg, tribromochloromethane, carbon tetrachloride, chloroform, bromoform), mercaptans (eg, lauryl mercaptan, and t-dodensyl mercaptan), and the like are used. The amount of chain transfer agent used is
The amount is about 0 to 10 parts by weight per 100 parts by weight of the ethylenically unsaturated monomer. Chelating agents include glycine, alanine,
Ethylenediaminetetraacetic acid and other pH adjusters that can be used include sodium carbonate, potassium carbonate, and sodium hydrogen carbonate. Chelating agent, PH
The amount of regulator used is 100% of the ethylenically unsaturated monomer.
They are about 0 to 0.1 parts by weight and 0 to 3 parts by weight, respectively. As a solvent, use small amounts of methyl ethyl ketone, acetone, trichlorotrifluoroethane, methyl isobutyl ketone, dimethyl sulfoxide, toluene, dibutyl phthalate, etc. within a range that does not impair workability, disaster prevention safety, environmental safety, and manufacturing stability. It's okay. The amount used is about 0 to 20 parts by weight per 100 parts by weight of the ethylenically unsaturated monomer. Emulsion polymerization of ethylenically unsaturated monomers can be carried out by known methods, such as charging the entire amount of the monomer into the reaction system in the presence of fluorine-based polymer particles at once, or charging a portion of the monomer and reacting. After that, the remaining amount is continuously or dividedly charged, the entire amount of the monomer is continuously charged, and the fluoropolymer particles are dividedly or continuously added while the monomer is reacting. can be done. The average particle size of the polymer particles in the aqueous polymer dispersion for coating of the present invention is 0.05 to 3.0 μm, preferably 0.1 to 3.0 μm.
It is about 10 μm. If the average particle size is less than 0.05 μm, the viscosity of the aqueous polymer dispersion will increase, making it impossible to obtain a polymer dispersion with a high solids content. It occurs and is not desirable. On the other hand, if it exceeds 3.0 μm, the storage safety of the aqueous polymer dispersion becomes poor, which is not preferable. The aqueous polymer dispersion obtained in the present invention can be used in combination with other aqueous polymer dispersions as long as its properties are not impaired. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. In addition, in these Examples, "parts" are "parts by weight." Example 1 A heater and a nitrogen gas introduction device were attached to a flask reactor equipped with a reflux condenser, a stirrer, a thermometer, and a monomer addition pump, and 80 parts of water and ethylene tetrafluoride were added to the flask reactor. - 3 parts (solid content equivalent) of propylene copolymer dispersion (composition ratio 55/45, average particle size 0.11 μm manufactured by Asahi Glass Co., Ltd.) and 0.3 part of sodium persulfate were charged, and the gas phase was heated with nitrogen gas for 15 minutes. The mixture was replaced and the temperature was raised to 75°C. After this, from a separate container, 53 parts of n-butyl acrylate and 35 parts of styrene were added.
parts, 10 parts of methyl methacrylate, 2 parts of methacrylic acid
A mixture of 50 parts of water and 0.2 parts of sodium alkylbenzenesulfonate as an emulsifier was continuously added over a period of 3 hours. After the addition was completed, the mixture was further aged at 85° C. for 2 hours, cooled, adjusted to pH 8 with aqueous ammonia, and filtered through 200 mesh gold steel. The average particle diameter of the obtained aqueous polymer after dispersion was 0.38 μm. (The average particle size was measured using Coulter's Nano-Sizer.) The aqueous polymer dispersion was placed in a container with a frame measuring 15 cm x 10 cm and a depth of 0.2 cm, so that the film thickness after drying was measured. It was poured to a thickness of 0.1 cm and dried for 14 days at 25°C and 60RH%. The resulting dried film was tested for non-tackiness in accordance with JIS K5400, and no tackiness was observed. Next, the solvent resistance was measured by the ratio of insoluble matter (% by weight) in the dry film of the aqueous polymer dispersion to the solvent (toluene). For the measurement, first, a dry film similar to that used for measuring non-tackiness was cut out to a size of 3.0 cm x 3.0 cm, weighed (w1), and then immersed in 500 c.c. of toluene in an Erlenmeyer flask with a stopper for 24 hours. After this,
The film was filtered through a 200-mesh wire mesh, and the weight of the film remaining on the wire mesh was measured (w2). Solvent (toluene) insoluble matter (%) was calculated using the following formula. A (%)=W1/W2×100 The solvent insoluble matter in this test was 53%. Next, the same dry film as above was punched out using a dumbbell shape No. 2, and the tensile strength, elongation at cutting, and 100% modulus were measured according to JIS K6301. As a result, the tensile strength was 160 Kg/cm ² , the elongation at cutting was 550%, and the 100% modulus was 32 Kg/cm ² . For comparison, the above test was conducted using the same tetrafluoroethylene-propylene copolymer dispersion as above, and the results are summarized in Table 1.

[Table] Yuras Comparative Example 1 Aqueous polymer dispersion obtained by reacting under the same reaction conditions without adding the fluorine-based polymer dispersion used in Example 1 and adjusting the pH to 8 with aqueous ammonia. was filtered through a 200 mesh wire mesh. The average particle diameter was 0.21 μm. The dried film of the obtained aqueous polymer dispersion was subjected to the same test as in Example 1. The adhesiveness was remarkable, with 0% solvent insoluble matter, tensile strength 82 Kg/cm ² elongation at break 470%, and 100% modulus 22 Kg/cm ² . From the results of Example 1 and Comparative Example 1, the dry film obtained from the aqueous polymer dispersion of the present invention has low stickiness and excellent solvent resistance, and the physical properties of the film are excellent. I understand that. Examples 2 to 3 Aqueous polymer dispersions were prepared in the same manner as in Example 1, except that the amount of the tetrafluoroethylene-propylene copolymer dispersion was changed. A dry film test was conducted under the same conditions as in Example 1.
The results are shown in Table 2.

[Table] Comparative Examples 2, 3, 4 The amount of the aqueous polymer dispersion obtained in Comparative Example 1 was changed to 100 parts (in terms of solid content) and the amount of tetrafluoroethylene-propylene copolymer emulsion (in terms of solid content). The same test as in Example 1 was conducted on the dried film. The results are shown in Table 3.

[Table] From the results of Comparative Examples 2 and 3, simply mixing the polymer dispersion with the fluorine-based polymer dispersion resulted in good results in non-stick properties and solvent resistance (chemical resistance). Furthermore, it can be seen from Comparative Example 4 that even if a large amount of the fluoropolymer dispersion was mixed, the solvent resistance was inferior to that obtained in Example 3, and the physical properties of the dried film were also inferior. Example 4 Nitrogen gas was introduced into a pressure reactor equipped with a stirrer, a thermometer, a jacket type cooler, and a monomer continuous addition pump for 20 minutes, and after expelling the air in the reactor, 150 parts of water, Tetrafluoroethylene-hexafluoropropylene copolymer dispersion (manufactured by Daikin Industries, Ltd.)
10 parts (solid content equivalent) of ND-1), 2.0 parts of sodium alkylbenzenesulfonate, sodium salt of β-naphthalenesulfonic acid-formalin condensate
0.2 parts, t-dodecylmercaptan 0.25 parts, ferrous sulfate 0.0045 parts, tetrasodium ethylenediaminetetraacetic acid 0.03 parts, styrene 5.0 parts, butadiene 7.0 parts,
Add 0.5 parts of fumaric acid and 2.5 parts of methacrylic acid to approx.
Stir at room temperature for 10 minutes. Next, the reaction vessel charge was heated to 40°C, and 0.08 parts of cumene hydroperoxide as a polymerization initiator and 0.03 parts of sodium formaldehyde sulfoxylate as a reducing agent were added.
(Above, redox-based decomposition) Temperature: 55-60℃
Hold time. Thereafter, 42.0 parts of styrene and 43.0 parts of butadiene were continuously added over 10 hours. Five hours after starting the continuous addition of styrene and butadiene, 0.01 part of cumene hydroperoxide was added, followed by sodium formaldehyde sulfoxylate.
0.005 part, plus polyoxyethylene nonyl phenyl ether (number of moles of oxyethylene added: 8)
0.5 part was added. After the continuous addition of styrene and butadiene, the temperature was maintained at 65°C for 4 hours. After this, raise the pH to 8.0 with potassium hydroxide aqueous solution,
After blowing steam to remove unreacted monomers, the solid content was reduced to 50% in a concentrator. The average particle diameter of the obtained aqueous polymer dispersion was 0.28 μm. (Paint formulation) 100 parts of the obtained aqueous polymer dispersion (solid content equivalent)
Calcium carbonate (Super SS,
200 parts (manufactured by Maruo Calcium Co., Ltd.), clay (K
clay, manufactured by Katsumitsuyama Mining Co., Ltd.) 50 parts, polycarboxylic acid sodium salt (SN-
DISPERSANT5044, manufactured by San Nopco Co., Ltd.)
2.0 parts, antifreeze agent ethylene glycol 1.0 parts,
Preservative (SN-215, manufactured by Sannopco Co., Ltd.) 0.05
Antifoaming agent (Foamaster AP, San Nopco Co., Ltd.)
Add 0.5 parts of 2-amino-2-methyl-1-propanol, 1.0 parts of zinc oxide, and 1.0 parts of carbon black, adjust the solid content to 72% with water, and then use it as a thickener. Hydroxyethyl cellulose (A-5000, manufactured by Fuji Chemical Co., Ltd.) was used and the viscosity of the paint was adjusted to 10,000 cps. The mixture was thoroughly mixed using a disper stirrer, and then transferred to a vacuum defoaming machine for defoaming. An iron plate (JIS-G3141, SPCCD plate, 0.8×
70 x 150 mm) using an airless spray gun so that the coating film after drying was 400 μm. The coated iron plate was dried at 130°C for 30 minutes. The coated plates were subjected to the following tests. (1) Adhesion Cross-cut the coating surface (2mm square)
10 x 10 pieces), then adhesive tape (Nichiban Co., Ltd.)
A peel test was conducted using The criteria for determining adhesion are as follows. ○: Number of remaining cut coated surfaces 100-90 △: 89-50 ×: 49-0 (2) Non-adhesion Measured according to JIS K5400. (3) Volatile oil resistance Tested using No. 2 volatile oil in accordance with JIS K5400. (4) Acid resistance Tested using a 1.0% sulfuric acid solution according to JIS K5400 (temperature 20±1°C, 8 hours). (5) Alkali resistance Tested using 5% sodium carbonate solution according to JIS K5400 (temperature 40
±2℃, 6 hours). (6) Durability A nut (M-6) was continuously dropped from a height of 2 m onto the painted surface from inside a vinyl pipe at an angle of 60°, and the weight of the nut when the base material was exposed was evaluated. Judgment was made using the following indicators. 5th grade 40Kg or more (Good) 4th grade 30-39 3rd grade 26-29 2nd grade 21-25 1st grade 20Kg or less (Bad) The results are shown in Table 4. For comparison, Table 4 also shows the test results when the fluoropolymer was used alone.

[Table] Durability 5th class 1st class
Examples 5 to 8 An aqueous polymer dispersion was prepared in the same manner as in Example 4 except for changing the amount of the tetrafluoroethylene-hexafluoropropylene copolymer dispersion charged during polymerization, and this was used in Example 4. Tested in the same manner. The results are shown in Table 5 together with the results of Example 4.

【table】

[Table] Comparative Example 5 Conducted on an aqueous polymer dispersion obtained by reacting in the same manner as in Example 4 except that no tetrafluoroethylene-hexafluoropropylene copolymer dispersion was added. A test similar to Example 4 was conducted. The results are shown in Table 6. The coating film using this aqueous polymer dispersion was poor in tack-free property, volatile oil resistance, acid resistance, and alkali resistance.

[Table] Comparative Examples 6, 7 To 100 parts (solid content equivalent) of the aqueous polymer dispersion obtained in Comparative Example 5, 10 parts and 40 parts of tetrafluoroethylene-hexafluoropropylene copolymer dispersion were added. The same test as in Example 4 was conducted on the mixed dispersion mixed with (in terms of solid content). The results are shown in Table 7. In the case of a mixed dispersion, the coating film was inferior in acid resistance, alkali resistance, and volatile oil resistance, and its durability was also slightly inferior.

[Table] Comparative Example 8 An aqueous polymer dispersion was prepared in the same manner as in Example 1, except that the amount of the tetrafluoroethylene-propylene copolymer dispersion was changed by 100 parts (solid content equivalent). The properties were evaluated in the same manner as in Example 1. The results are shown below. Non-adhesion: Very good Solvent-insoluble content: 100% Tensile strength (Kg/cm ² ): 95 Elongation at cutting (%): 890 100% modulus (Kg/cm ² ): 15 Comparative example 9 Example 4 A coating was prepared in the same manner as in Example 4, except that the amount of the tetrafluoroethylene-hexafluoropropylene copolymer dispersion was changed by 100 parts (solid content equivalent), and its properties were compared to those in Example 4. Evaluation was made in the same manner. The results are shown below. Adhesion: × Non-adhesiveness: Very good Volatile oil resistance: No abnormality Acid resistance: No abnormality even when immersed in acid Alkali resistance: No abnormality even when immersed in alkali Durability: Grade 2 Based on the results of Comparative Examples 8 and 9 It is understood that if the proportion of the fluoropolymer particles used relative to the ethylenically unsaturated monomer is too large, a good aqueous polymer dispersion, which is the object of the present invention, cannot be obtained. Example 9 In Example 1, instead of the tetrafluoroethylene-propylene copolymer dispersion, a vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer dispersion (average particle size 0.25 μm, manufactured by Benwalt Co., Ltd.) was used. ) latex before coagulation of KYNAR9301) 80
35 parts of methyl methacrylate, 35 parts of ethylenically unsaturated monomer added continuously (based on solid content),
An aqueous polymer dispersion having an average particle diameter of 0.36 μm was obtained in the same manner as in Example 1, except that 63 parts of ethyl acrylate, 1 part of acrylic acid, and 1 part of itaconic acid were used.
A dry film obtained from this aqueous polymer dispersion was evaluated in the same manner as in Example 1. The results are shown below. Non-adhesion: Good Solvent-insoluble content: 45% Tensile strength (Kg/cm ² ): 110 Elongation at cutting (%): 250 100% modulus (Kg/cm ² ): 75 Using the above aqueous dispersion A coating was prepared in the same manner as in Example 4, and its properties were evaluated in the same manner as in Example 4. The results are shown below. Adhesion: ○ Non-adhesiveness: Good Volatile oil resistance: No abnormality Acid resistance: No abnormality even when immersed in acid Alkali resistance: No abnormality even when immersed in alkali Durability: Grade 4 comparative example 10 Foot used in Example 9 Vinylidene chloride-ethylene tetrafluoride-propylene hexafluoride copolymer dispersion
The physical properties of the dry film and coating film of (A) were evaluated in the same manner as in Example 9. The results are shown in Table 8. Comparative Example 11 In Example 9, vinylidene fluoride-ethylene tetrafluoride-propylene hexafluoride copolymer dispersion (A)
A copolymer dispersion (B) was obtained in the same manner as in Example 9 except that . The dry film properties and coating properties of this copolymer (B) were evaluated in the same manner as in Example 9. The results are shown in Table 8. Comparative Example 12 The fluoropolymer dispersion (A) of Comparative Example 10 and the copolymer dispersion (B) of Comparative Example 11 were mixed at (A)/(B)=80/100 (solid content weight ratio) The physical properties of the dry film and the physical properties of the coating film of this mixed dispersion were determined according to Example 9.
It was evaluated in the same way. The results are shown in Table 8.

〔Effect of the invention〕

The aqueous polymer dispersion for coating of the present invention has excellent chemical resistance, solvent resistance, non-adhesiveness, physical properties, and adhesion to substrates, and can be produced at low cost, and can be used as a paint, fiber treatment agent, etc. It can be used for paper processing materials, floor coating materials, carpets, packing materials, non-adhesive treated materials, sealing materials, and water- and oil-repellent treated materials.

Claims (1)

[Claims] 1 In an aqueous medium, the ethylenically unsaturated monomer is mixed with 0.5 to 90 parts by weight of ethylene tetrafluoride-propylene copolymer, ethylene tetrafluoride-propylene hexafluoride copolymer per 100 parts by weight of this monomer. An aqueous polymer dispersion obtained by emulsion polymerization in the presence of at least one fluorinated polymer particle selected from copolymers of vinylidene fluoride and a monomer copolymerizable therewith. An aqueous polymer dispersion for coating, characterized in that the average particle diameter of polymer particles in the aqueous polymer dispersion is 0.05 to 3 μm.