JPH0439313A - Water-dilutable fluoropolymer and method for producing aqueous liquid of the polymer - Google Patents

Abstract

PURPOSE:To obtain the subject aqueous liquid, capable of providing films excellent in weather resistance, etc., by reacting a hydroxyl group- and fluorine- containing polymer with an isocyanate group-containing vinyl monomer and a carboxyl group-containing vinyl polymer in an organic solvent, neutralizing the resultant polymer with a basic compound and adding water thereto. CONSTITUTION:A hydroxyl group- and fluorine-containing polymer (preferably prepared by copolymerizing vinyl fluoride, etc., with hydroxyethyl vinyl ether, etc.) is reacted with an isocyanate group-containing vinyl monomer (e.g. tolyene diisocyanate) and then a carboxyl group-containing vinyl monomer (preferably an acrylic acid ester, etc.) in an organic solvent (e.g. methylal) having no active hydrogen group and the resultant reaction product is then neutralized with a basic compound (e.g. ammonia). Water is then added to the neutralized reaction product and the aforementioned organic solvent is removed to afford the objective aqueous liquid suitable as coatings, etc.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a water-dilutable fluoropolymer suitable for paints that forms a film with excellent weather resistance, water resistance, etc., and an aqueous solution of the polymer. The present invention relates to a manufacturing method.

(Conventional technology and its problems to be solved) In recent years, resource saving,
Due to the focus on energy conservation, pollution reduction, and safety, there is active consideration of switching from organic solvent-based paints to water-based paints that use water as a medium.

Conventionally, acrylic emulsion resins produced by emulsion polymerization have been widely used as resins for water-based paints, but they do not satisfy long-term weather resistance as the demand for maintenance-free resins increases. In addition, various water-dispersed resin aqueous liquids produced by solvent-based resin solutions or filtration phase conversion methods are also used, but these aqueous liquids contain many organic solvents, which pose many health and safety problems, and also have weather resistance. Sexuality was also insufficient. Therefore, fluororesin water-based paints with excellent weather resistance are attracting attention.

However, since the film formation temperature of conventional fluorine-sulfur resin-based water-based paints is high, high-temperature baking drying is required, and a large number of hydrophilic groups are required for self-emulsification in water. As a result, there was a problem that water resistance decreased.

In view of the current situation, the inventors of the present invention have developed a method that takes advantage of the good weather resistance of fluororesin, forms a film at a lower drying temperature, provides a film with excellent water resistance, and eliminates virtually all harmful organic solvents. The present invention was developed as a result of intensive studies aimed at developing an aqueous fluoropolymer solution that does not contain fluorine-containing polymers.

(Means for Solving the Problem) That is, the present invention provides a vinyl monomer component containing an isocyanate group-containing vinyl monomer and a hycarboxyl group-containing vinyl monomer, or the vinyl monomer component, in a fluorine-containing polymer having a hydroxyl group. A water-dilutable fluoropolymer obtained by grafting a copolymer of the above to introduce a carboxyl group into the fluoropolymer and neutralizing it with a basic compound, and an aqueous polymer of the copolymer. The present invention relates to a method for producing a dispersion liquid. Since the fluoropolymer of the present invention has carboxyl groups in the grafted vinyl copolymer, it can be diluted with water even with a relatively small amount of hydrophilic groups, and as a result, the water resistance is lower than that of the conventional one. It is much improved compared to , and it is possible to increase the molecular weight.
Various physical properties of the film can be significantly improved.

The present invention will be explained in detail below.

The fluorine-containing polymer having a hydroxyl group used in the present invention is a copolymer produced by using a fluoroolefin, a vinyl monomer having a hydroxyl group, and other vinyl monomers.

Examples of the fluoroolefins include vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrafluoroethylene, 1,1-dichloro-2,2-difluoroethylene, 1-chloro-2,2-difluoroethylene, and 1-dichloro-2,2-difluoroethylene. Rolow 1.2-difluoroethylene, hexafluoropropylene, 1,1,3,3.3-pentafluoropropylene, 2. 3. 3. 3-tetrafluoropropylene, 3,3.3-trifluoropropylene,
1, 1. 2-) Lifluoropropylene etc., but are not limited thereto. In the present invention, one kind or a mixture of two or more kinds of these can be used.

Examples of vinyl monomers having a hydroxyl group include vinyl ethers such as hydroxyethyl vinyl ether, hydroquine butyl vinyl ether, hydroxycyclohexyl vinyl ether, allyl ethers such as hydroxybutyl allyl ether, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, Examples include acrylic esters and methacrylic esters such as 2-hydroxypropyl methacrylate, 2-hydroquine butyl methacrylate, and polyethylene glycol methacrylate; acrylamides and methacrylamides such as hydroquine ethyl acrylamide and hydroxyethyl methacrylamide; It is not limited to these.

Other vinyl monomers include acrylic acid,
Methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, 2-methacryloyloxyethylsuccinic acid,
2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxyethyl maleic acid, 2-acryloyloxyethyl succinic acid, β-carboxyethyl methacrylate, CF2CF2 (CF2)l, C○OH (n is O
~8 integer), CF2=CF (CF2), C0OH
Carboxyl group-containing vinyl monomers such as (n is an integer of 0 to 8), carbon atoms such as cyclohexyl vinyl ether, ethyl vinyl ether, ethyl vinyl ether, etc.
Vinyl ethers having ~8 side chains, vinyl benzoate vinyl pepivalate, vinyl acetate, vinyl carboxylate esters such as vinyl butyrate monomer, methyl acrylate, ethyl acrylate, n-butyl acrylate, imbutyl acrylate, t- butyl acrylate,
2-Ethylhexyl acrylate, cyclohexyl acrylate, isoamyl acrylate, tridecyl acrylate, tetrahydrofurfuryl acrylate, methoxypolyethylene glycol acrylate, butoxyethyl acrylate, dimethylaminoethyl methacrylate, glycidyl acrylate, inbornyl acrylate 1/-
Acrylic esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate 1. Isopropyl methacrylate, n-butyl methacrylate, inbutyl methacrylate, t-butyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, tridecyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, methoxypolyethylene glycol methacrylate, dimethylaminoethyl methacrylate,
Methacrylic acid esters such as diethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, glycidyl acrylate, isobornyl methacrylate, dicyclopentenyl methacrylate, acrylonitrile, nitriles in the order of methacrylate, acrylamide, methacrylamide, dimethylacrylamide, methylenebisacrylamide , acrylamides and methacrylamides such as methoxymethylacrylamide, N-butoxymethylacrylamide, dimethylaminopropylacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide, allyl ethers such as allyl glycidyl ether, CH2=CHCH20CH2
CH(DH)CH2C0OR.

CH2=CHCH20CH2CH2(DH)CH20C
Allylureido monomers such as H2CH, NCONH, chlorine-containing monomers such as vinylidene chloride, etc. Compounds represented by the general formula: CH2=C(R,)CoOx, for example, CH2= CHCOOCH2CF s, CH2=CH
C00CH2CF2CF2H.

CH2=CHC00CH2(CF2CF2)
2 H.

CH2=CHC○○CH2(CF2CF2)3H-CH
2=CHC00CH2C7F 1s, CH2= CH
COOCH2CH2Cs F, fluorine-containing monomers such as 7, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane,
Silicon-containing vinyl monomers such as vinyltrimethoxysilane and T-methacryloxypropyltriethoxysilane 2-
Acrylaminomethylpropanesulfonic acid, t-butyl acrylic estermidosulfonic acid, sodium styrene sulfonate, CH2=CHCH200CCH (SO3Na) CH
2C0OR.

C112=CHCH20CH, CH(DH) CH20
0CC)l (So3λ1)CH2C[ll[]R(M
=Na, NH, ), sulfonic acid and phosphoric acid group-containing monomers such as acryloyloxyethyl acid phosphate, but are not limited thereto. For tree climbing gates, one kind or a mixture of two or more kinds of these can be used.

The fluorine-containing polymer having hydroxyl groups contains 10 to 60 mol% of fluoroolefins and 0% of vinyl monomers having hydroxyl groups.
．． 1 to 50 mol%, and 1 to 50 mol% of other vinyl monomers
Copolymerization at a ratio of 70 mol% is suitable.

In addition, the hydroxyl value of the fluoropolymer is 1 to 200.
, preferably 1 to 100, an acid value of 0 to 20, and a number average molecular weight of 500 to 100,000. still,
The hydroxyl group of the fluoropolymer is necessary for grafting the vinyl monomer component or its copolymer described later. Therefore, it is appropriate for the hydroxyl value to be within the above range; if it is smaller than the range, it becomes difficult to undergo grafting reaction and, as a result, it becomes difficult to emulsify in water, while if it is larger than the range, water resistance tends to decrease.

The isocyanate group-containing vinyl monomer (a) used in the present invention reacts with the isocyanate group in the monomer and the hydroxyl group in the fluoropolymer, and the vinyl monomer (a) described later is
In order to impart a polymerizable unsaturated group to the fluorine-containing polymer so that it can undergo a grafting reaction with b), or to form a copolymer with the vinyl monomer (b) described below, the isocyanate group in the copolymer and the fluorine-containing Reacts with hydroxyl groups in the polymer,
It is used to graft the copolymer onto a fluoropolymer. Isocyanate group-containing vinyl monomer (a
) include diisocyanate compounds such as tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylene diisocyanate, and inphorone diisocyanate; Adducts with hydroxy group-containing vinyl monomers such as allyl ether, isocyanate ethyl acrylate, isocyanate butyl acrylate, isocyanate hexyl acrylate,
Examples include, but are not limited to, acrylates and hismethacrylates such as isocyanate ethyl methacrylate, isocyanate butyl methacrylate, isocyanate hexyl methacrylate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, methacroyl isocyanate, acroyl isocyanate, etc. Not necessarily. Particularly useful are the isocyanates ethyl methacrylate, m-inflabenyl-α, α-dimethylbenzyl isocyanate, and methacryloyl isocyanate. still,
The isocyanate group-containing vinyl monomer (a) has an equivalent ratio (OH/N
It is appropriate to mix them in such a range that GO) is from 1 to 50 and then carry out the urethanization reaction.

The vinyl monomer used in the present invention contains a carboxyl group-containing vinyl monomer at least in part,
When the fluoropolymer obtained through the final grafting reaction is neutralized with a basic compound, it is blended to introduce carboxyl groups into the fluoropolymer so that it dissolves or stably emulsifies and disperses in water. do. A representative example of the carboxyl group-containing vinyl monomer is the "carboxyl group-containing vinyl monomer" listed as a component of the fluoropolymer. In addition to the carboxyl group-containing vinyl monomer, it is desirable to use other vinyl monomers as the vinyl monomer (2). Can be mentioned. especially,
Acrylic esters and methacrylic esters are preferred.

The blending ratio of the fluoropolymer and the vinyl monomer is 95 parts/15 parts to 20 parts/80 parts (by weight), preferably 90 parts/10 parts to 50 parts/150 parts. If the former is less than the above range, the inherent properties of the fluoropolymer, such as weather resistance, will tend to deteriorate, while if it is too much, it will tend to be difficult to dilute with water in a stable state. Also vinyl monomers etc.)
The blending ratio of carboxyl fund F vinyl monomer in the inside is 0.
．． It is 5 to 30 mol%, preferably 2 to 10 mol%.

Within this range, the fluoropolymer can be diluted with water in a stable state without reducing the water resistance of the film obtained.

Next, a typical method for producing the aqueous liquid of the fluoropolymer of the present invention will be explained. Typically, the following three methods are suitable, but the method is not limited to these.

(1) A fluoropolymer containing a hydroxyl group and a vinyl monomer containing an isocyanate group are reacted in an organic solvent having no active hydrogen groups, and the obtained fluoropolymer having a polymerizable unsaturated group contains a carboxyl group. A fluoropolymer obtained by subjecting a vinyl monomer component containing a vinyl monomer to a grafting reaction, then neutralizing the resulting carboxyl group-containing fluoropolymer with a basic compound, adding water, and then removing the organic solvent. Method for producing aqueous liquid.

(2) copolymerizing a vinyl monomer component containing an isocyanate group-containing vinyl monomer and a carboxyl M-containing vinyl monomer in an organic solvent having no active hydrogen groups,
The obtained isocyanate group- and carboxyl group-containing copolymer is grafted onto a fluoropolymer having a hydroxyl group, and then the obtained carboxyl group-containing fluoropolymer is neutralized with a basic compound, water is added, and then and then removing the organic solvent.

(3) A vinyl monomer component containing an isocyanate group-containing vinyl monomer and a carboxyl group-containing vinyl monomer is subjected to a crafting reaction with a fluorine-containing polymer having a hydroxyl group in an organic solvent having no active hydrogen groups, and the obtained carboxyl group-containing 1. A method for producing an aqueous fluoropolymer liquid, which comprises neutralizing the fluoropolymer with a basic compound, adding water, and then removing the organic solvent.

The organic solvent used in the above three methods is one that does not react with the isocyanate group in the isocyanate group-containing vinyl monomer (a), that is, an organic solvent that does not have an active hydrogen group. Furthermore, as mentioned above, the organic solvent must be removed from the fluoropolymer permanent solution at the earliest stage. An azeotropic urethane is preferable. Examples of such organic solvents include, but are not limited to, the following. Examples of organic solvents with a boiling point of 95°C or lower include methylal (42.3°C) [the number in parentheses is 76
Boiling point at 0 mHg. 1,2-dimethoxyethane (85.2℃), tetrahydrofuran (66℃)
, tetrahydropyran (88℃), ethers such as dipropyl ether (90.5℃), diethyl ether (34.6℃), propyl formate (81.3℃), ethyl formate (54.1℃), acetic acid. Esters such as methyl (57.8°C), ethyl acetate (77.1°C), isopropyl acetate (89°C), methyl propionate (79.7°C), acetone (56°C), methyl ethyl ketone (76°C), etc. ketones, chloroform (61.15°C), carbon tetrachloride (7
6,75℃), cyclohexane (80,7℃), benzene (80℃), hexane (6℃), etc.
Examples include hydrocarbons such as 8.7°C). Also, 95
As an organic solvent that can azeotrope with water at temperatures below ℃, ethyl butyl ether (76℃, 106%) has a numerical value of 760.
The boiling point of a binary azeotrope in mHg and the proportion of the components in the azeotrope. Same below], 1゜2-shedquin ethane (89.4℃, 25%), 1.3.5-)dioxane (91.4℃, 30%), dioxane (35℃,
Ether jaws such as 36.9%), propyl acetate (82.4%) etc.
°C, 14%), isopropyl acetate (76.6 °C, 10.
6%), butyl acetate (90.2°C, 28.7%), isobutyl acetate (79.5°C, 16%), butyl formate (83
, 3°C, 16.5%), isobutyl formate (79,5°C,
18.5%), propyl propionate (88.9°C, 2
3%), ethyl butyrate (87.9°C, 21.5%), propyl butyrate (94°C, 36.4%), methyl isobutyrate (7
7.7℃, 6.8%), ethyl isovalerate (922℃,
30.2%), 2-pentanone (83,
3°C, 19.5%), 3-pentanone (82.9°C, 1
4%〉, 4-methyl-2-pentanone (87.9℃,
243%), 3-heptanone (94.6°C, 42.2%
), 4-heptanone (94.3°C, 40.5%), 3-
Penten-2-one (92°C, 28.6%), 3-methyl-2-buten-2-one (81,5°C, 18.4%
), 3-methyl-2-butanone (81.5°C, 18.4
%), ketones such as acetylacetone (94.4°C, 41%), ethylbenzene (92°C, 33%), m-xylene (94.5°C, 40%), toluene (85°C, 19%),
．． 91%), hydrocarbons such as heptane (79.2℃, 12.9%), chlorobenzene (90.2℃, 28.4%)
) and other halogenated hydrocarbons. Incidentally, one or a mixture of two or more of these may be used.

Basic compounds used in the three methods include ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, dimethylethanolamine, diethylethanolamine, jetanolamine, triethanolamine, etc. It is not limited to this. The basic compound has an equivalent ratio of 0.5 to the acid group of the fluoropolymer.
It is appropriate to use it in the range of ~2.0.

In the method (1) above, a hydroxyl group in a fluoropolymer is reacted with an isocyanate group in a vinyl monomer (a) to introduce a polymerizable unsaturated group into the fluoropolymer, and a carboxyl group is added to the unsaturated group. This method involves introducing a carboxyl group into a fluoropolymer by subjecting a vinyl monomer (b) containing a group-containing vinyl monomer to a radical copolymerization reaction. The fluoropolymer and the isocyanate group-containing vinyl monomer (a) are typically reacted by heating at a temperature of 50 to 150°C in the presence of a catalyst such as dibutyltin dilaurate. The method is not limited. The thus obtained fluorine-containing polymer having a polymerizable unsaturated group and the vinyl monomer (b) containing a carboxyl group-containing vinyl heptamer are 2,2-azobisisobutyronitrile, 2.2 - A typical method is to carry out a heating reaction at a temperature of 50 to 150°C in the presence of a radical polymerization initiator such as azobisvaleronitrinobebenzoyl peroxide, but it is not limited to this method. . After neutralizing the carboxyl group-containing fluoropolymer thus obtained with the basic compound,
Water is added, and then the organic solvent is removed, preferably at a temperature of 95°C, to prepare an aqueous fluoropolymer liquid.

In addition, when removing the organic solvent, it is preferable to remove the organic solvent without introducing air or nitrogen, or under reduced pressure.

In the method (2) above, a vinyl monomer (a) and a vinyl monomer (b) are radically polymerized to form a copolymer containing one isocyanate group and a carboxyl group, and the isocyanate group and the fluorine-containing polymer in the copolymer are This is a method in which carboxyl groups are introduced into the fluoropolymer by reacting with the hydroxyl groups of the combined polymer. Incidentally, these reactions can be carried out by heating the reaction in the presence of the radical polymerization initiator and catalyst in the same manner as the method (1) above. Furthermore, an aqueous fluoropolymer solution can also be prepared in the same manner.

The above method (3) is a method in which the reactions according to the above methods (1) and (2) are carried out simultaneously to introduce carboxyl groups into the fluoropolymer. In this case, the carboxyl group-containing fluoropolymer can be produced by carrying out a heating reaction in the presence of the radical polymerization initiator and catalyst. Further, an aqueous fluoropolymer liquid can also be prepared in the same manner as the method (1) above.

The aqueous fluoropolymer liquid thus obtained is adjusted to have a nonvolatile content of about 20 to 65% by weight, and if necessary, inorganic coloring pigments such as titanium white, cadmium yellow carbon black, and phthalocyanine-based , organic coloring pigments such as azo, metallic powder, calcium carbonate,
Extender pigments such as talc, ordinary pigment dispersants, thickeners,
It can be used as clear paints, enamel paints, and metallic paints by adding various additives such as antifoaming agents, ultraviolet absorbers, light stabilizers, and film-forming aids. These paints can be used as a drying type at room temperature, but if necessary, they can also be used as a baking hardening type using a crosslinking agent such as a polyisocyanate compound or an aminoplast compound.

(Effects of the Invention) The fluoropolymer and the aqueous liquid of the polymer of the present invention can be formed into a film at a dry smoke temperature as low as 1 degree while taking advantage of the good weather resistance of fluoropolymer, and Carboxyl groups are introduced into the vinyl copolymer grafted onto the polymer, making it possible to dilute with water even with a relatively small amount of hydrophilic groups, resulting in significantly improved water resistance and higher molecular weight. It has the characteristic that it can significantly improve various physical and chemical properties of the film.

Furthermore, the aqueous liquid of the fluoropolymer of the present invention is highly safe since it does not substantially contain an organic solvent, and can be used as a non-polluting paint.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples. still,
In the following, "parts" and "%" are expressed on a weight basis.

Example 1 51.5 mol% of chlorotrifluoroethylene, 17.2 mol% of cyclohexyl vinyl ether, 22.4 mol% of ethyl vinyl ether, and 8.9 mol% of hydroquine butyl vinyl ether; 6 acid value 0 A fluorine-containing polymer having a hydroxyl value of 50 and a number average molecular weight of 20,000 was prepared, and the organic solvent contained therein was vacuum-dried. Fill the flask with tetrahydrofuran (760 mHg, 8 points at 66°C) 5
00 parts, 140 parts of methyl methacrylate, 50 parts of butyl methacrylate, 10 parts of -. After reacting for 6 hours at ℃, the above-mentioned fluoropolymer 250 and dibutyltin dilaure) 0. 5 parts of OO was added and the reaction was continued for an additional 2 hours.

After adding 12.5 parts of dimethylethanolamine to neutralize it and emulsifying it by adding water 10009 while stirring, nitrogen was introduced while maintaining the temperature at 65 to 75°C to remove and recover tetrahydrofuran over a period of 2 hours. A milky white dispersion was obtained. The dispersion has a nonvolatile content of 42%, a pH of 9.3, and a viscosity of 6.
00 cps, acid value 17, particle size 150 nm (laser light scattering method), and was stable even after being left for 3 months.

Example 2 Preliminary composition of 47.8 mol% of chlorotrifluoroethylene, 31.5 mol% of cyclohexyl vinyl ether, 15.3 mol% of phthyl vinyl ether, and 5.4 mol% of hydroquine butyl vinyl ether with an acid value of 0 and a hydroxyl value of 30
．． A fluoropolymer having a number average molecular weight of II O,000 was prepared, and the organic solvent contained therein was vacuum-dried. In a flask, 500 parts of ethyl acetate (760 mHg, boiling point 77°C), 400 parts of the above fluoropolymer, 65 parts of methyl methacrylate,
25 parts of 2-ethylhexyl acrylate, 10 parts of methacrylic acid, 1 part of isocyanate ethyl methacrylate! ,2
゜4.5 parts of 2-azobisisobutyroni) and 0.01 part of dibutyltin dilaure) were heated at 75°C.
It's time sensitive.

Add 12.5 parts of dimethylethanolamine to neutralize this, add 100 parts of butyl cellosolve, and add 750B of water with stirring to emulsify it, then keep it at 75-80°C and inject nitrogen for 2 hours. Ethyl acetate was removed and recovered to obtain a milky white dispersion. The dispersion has a non-volatile content of 40
%, pH 9.3, viscosity 1800 cps, acid value 13, particle size 130 nm (laser light scattering method).It is stable even after being left for 3 months.Example 3 Preliminary preparation of chlorotrifluoroethylene'48.5 mol%, cyclohexyl vinyl ether 205 mol %, ethyl vinyl ether 27.2 mol%, and hydroxypropyl vinyl ether 3.8 mol%, succinic anhydride was reacted with a fluorine-containing polymer having an acid value of 1, a hydroxyl value of 20, and a number average molecular weight of 15,000. A fluoropolymer was prepared, and the organic solvent contained therein was vacuum-dried. In a flask, 480 parts of methyl ethyl ketone (760 mHg, boiling point 76°C), 540 parts of the above fluorine-containing polymer, 24 parts of methyl methacrylate,
24 parts of 2-ethyl hequinyl acrylate, 2-hydroxyethyl methacrylate-6E, 6 parts of a(furylic acid), 2 parts of ethyl methacrylate isocyanate, 1 part of 2゜2-azobisinbutyronide IJ , and dibutyltin dilaure) were added and reacted at T5° C. for 8 hours.

Add 12.5 parts of dimethylethanolamine to neutralize it, add 7IO parts of water with stirring to emulsify it, and then reduce the pressure to 650-750 m while maintaining the temperature at 70-80°C.
Methyl ethyl ketone was removed and recovered using Hg for 2 hours.
A milky white dispersion was obtained.

The dispersion has a nonvolatile content of 45%, a pH of 9.8, and a viscosity of 920c.
ps, acid value 9, and particle size 110 nm (laser light scattering method), it was stable even after being left for 3 months.

Example 4 Pre-mehexafluorobrobylene 4 g, 2 mol%, ethyl vinyl ether 27.7 mol%, hydroxybutyl vinyl ether 10.7 mol%, and vinyl hibernate 13.4 mol%, acid value 0, hydroxyl value A fluoropolymer having a number average molecular weight of 30,000 and a number average molecular weight of 30,000 was prepared, and the organic solvent contained therein was vacuum-dried.

700 parts of dipropyl ether (760 mHg, boiling point 90.5°C) and the above fluoropolymer 420B were placed in a flask.
, rn-impropenyl-α, α-dimethylbenzyl isocyanate 0.5 part, and dibutyltin dilaure) 0
．． Add 01 parts and let it react at 50°C for 2 hours. Furthermore,
50 parts of methyl methacrylate, 60 parts of cyclohexyl methacrylate, 60 parts of butyl acrylate, 9 parts of methacrylic acid, and 2.5 parts of t-butylperoxy-2-ethylhexanoate were charged and reacted at 90°C for 7 hours.

To this, 12.58 parts of dimethylethanolamine was added to neutralize it, 60 parts of butyl cellosolve was added, and 900 parts of water was added with stirring to emulsify. Dipropyl ether was removed and recovered over time to obtain a milky white dispersion. The dispersion has a nonvolatile content of 40%, a pH of 9.5, and a viscosity of 1100 cp.
s, acid value 10, particle size 160 nm (laser light scattering method)
It remained stable even after being left for three months.

Example 5 Pre-mehexafluoropropylene 46.7 mol%, ethyl vinyl ether 23.7 mol%, hydroxybutyl vinyl ether 14.3 mol%, and vinyl pivalate 15
．． 3 mol% copolymer reacted with succinic anhydride to introduce a carboquine group, acid value 15, hydroxyl value 80,
A fluorine-containing polymer having a molecular weight of 15,000 was prepared, and the organic solvent contained therein was vacuum-dried. Toluene (760
mHg, boiling point 110°C) 700 parts, 350 parts of the above fluorine-containing polymer, 200 parts of methyl methacrylate, 140 parts of butyl acrylate, 7 parts of methacrylic acid, 0.3 part of methacryloyl ylananate, t-butylperoxy-2
-7 parts of ethylhexanoate and 0.01 part of dibutyltin dilaure were added and the mixture was reacted at 90°C for 7 hours.

Add 15 parts of dimethylethanolamine to neutralize this, add 200 parts of butyl cellosolve, and add 1 part of water while stirring.
After adding 800 parts and emulsifying, toluene and water were azeotropically distilled at a reduced pressure of 650 to 750 mHg while maintaining the temperature at 85 to 95°C, and toluene was removed and recovered over 5 hours to obtain a milky white dispersion. The dispersion had a nonvolatile content of 36%, a pH of 9.1,
Viscosity 900cps.

Acid value: 14, particle size: 140 nm (laser light scattering method): 3
It remained stable even after being left for several months.

Comparative Example 1 The same procedure as in Example 2 was carried out except that isocyanate ethyl methacrylate was not used. The liquid became opaque before neutralization, and after emulsification, it coagulated and precipitated during removal of the solvent, making it unsuitable as an aqueous liquid for paints. there were.

Comparative Example 2 In place of 500 parts of ethyl acetate as the organic solvent in Example 2, 400 parts of isopropyl alcohol having an active hydrogen group was used.
When the solution was changed to 100 parts and 100 parts of methyl cellosolve, the solution became opaque before neutralization, and after emulsification, flocculated and precipitated during removal of the solvent, making it unsuitable as an aqueous solution for paints.

Comparative Example 3 Succinic anhydride was added to a copolymer consisting of 48.5 mol% pre-mechlorotrifluoroethylene, 18.6 mol% cyclohexyl vinyl ether, 15.0 mol% ethyl vinyl ether, and 17.9 mol% hydroxybutyl vinyl ether. A reacted fluorine-containing polymer having an acid value of 20, a hydroxyl value of 80, and a number average molecular weight of 5,000 was prepared, and the organic solvent contained therein was vacuum-dried. Ethyl acetate (760
mHg, boiling point 77t) 500 parts, the above fluoropolymer 4
00 parts, and a seven-mer composition containing no carboxyl group-containing vinyl monomer, 75 parts of methyl methacrylate, 2
-25 parts of ethylhexyl acrylate, 1 part of ethyl isocyanate methacrylate, 1.5 parts of 2,2-azobisisobutyronitrile, and 0.0 parts of dibutyltin dilaurate.
01 part was charged and reacted at 75℃ for 8 hours.

When this was neutralized by adding 12.5 parts of dimethylethanolamine, 100 parts of butyl cellosolve was added, and 750 parts of water was added with stirring to emulsify it, agglomeration and precipitation occurred, making it unsuitable as an aqueous liquid for paints.

Comparative Example 4 An acrylic polymer having an acid value of 0, a hydroxyl group g of 530, and a molecular weight of 10,000 was prepared in advance from 30 mol% of methyl methacrylate, 30 mol% of butyl methacrylate, 30 mol% of butyl acrylate, and 10 mol% of hydroxymethyl methacrylate, The organic solvent contained was dried under vacuum.

Ethyl acetate (760 mHg, boiling point 77°C) in the flask
500 parts, 400 parts of the above acrylic polymer, 65 parts of methyl methacrylate, 25 parts of 2-ethyl hequinyl acrylate
Evil, 10 parts of methacrylic acid, 1 part of isocyanate ethyl methacrylate, 1 part of 2,2-azobisisobutyronitrile
．． 5 parts of dibutyltin dilaurate and 0.01 part of dibutyltin dilaurate were added and the reaction was continued at 75°C for 8 hours.

Add 12.5 parts of dimethylethanolamine to neutralize this, add 100 parts of butyl cellosolve, and add 750 parts of water while stirring to emulsify. Then, while maintaining the temperature at 75 to 80°C, nitrogen was introduced into the mixture for 2 hours. Ethyl acetate was removed and collected to obtain a milky white dispersion. The dispersion has a non-volatile content of 39%
, pH 9.5, viscosity 2500 cps, acid value 13, particle size 120 nm (laser light scattering method), and was stable even after being left for 3 months.

Application Examples 1 to 5 Based on the formulations in Table 1, paints were prepared using the aqueous dispersions of Examples 1 to 4 and Comparative Example 4. A slate plate previously coated with a sealer paint was air-sprayed with each paint so that the film thickness after drying was 30 μm, and the paint was dried at room temperature for 2 weeks to prepare a test piece.

Application Example 6 Based on the formulation shown in Table 1, a paint was prepared using the aqueous dispersion of Example 5. Paint was air-sprayed onto a zinc phosphate-treated iron plate so that the film thickness after drying was 30 μm.
A test piece was prepared by baking at 0°C for 20 minutes.

Adhesion, water resistance, and weather resistance tests were conducted on the obtained test piece. The results are shown in the lower column of Table 1.

As can be clearly seen from Table 1, the coating films of Application Examples 1 to 4 and 6 using the fluoropolymer of the present invention all had excellent coating film performance.

On the other hand, the coating film of Application Example 5 using a conventional acrylic polymer had poor water resistance and weather resistance.

Claims (4)

[Claims] (1) A vinyl monomer component containing an isocyanate group-containing vinyl monomer and a carboxyl group-containing vinyl monomer, or a copolymer of the vinyl monomer component is subjected to a grafting reaction on a hydroxyl group-containing fluoropolymer to form a grafting reaction on the fluoropolymer. A water-dilutable fluoropolymer obtained by introducing a carboxyl group and then neutralizing it with a basic compound. (2) A fluoropolymer containing a hydroxyl group and a vinyl monomer containing an isocyanate group are reacted in an organic solvent having no active hydrogen groups, and the obtained fluoropolymer having a polymerizable unsaturated group contains a carboxyl group. A vinyl monomer component containing a vinyl monomer is subjected to a grafting reaction, and then the resulting carboxyl group-containing fluoropolymer is neutralized with a basic compound, water is added, and then the organic solvent is removed. A method for producing an aqueous fluoropolymer liquid. (3) copolymerizing a vinyl monomer component containing an isocyanate group-containing vinyl monomer and a carboxyl group-containing vinyl monomer in an organic solvent having no active hydrogen groups,
The obtained isocyanate group- and carboxyl group-containing copolymer is grafted onto a hydroxyl group-containing fluoropolymer, and then the obtained carboxyl group-containing fluoropolymer is neutralized with a basic compound, water is added, and then water is added. , a method for producing an aqueous fluoropolymer liquid, which comprises removing the organic solvent. (4) Grafting a vinyl monomer component containing an isocyanate group-containing vinyl monomer and a carboxyl group-containing vinyl monomer onto a hydroxyl group-containing fluoropolymer in an organic solvent that does not have an active hydrogen group, resulting in a carboxyl group-containing product. After neutralizing the fluoropolymer with a basic compound,
A method for producing an aqueous fluoropolymer liquid, which comprises adding water and then removing the organic solvent.