JP2911467B2 - Resin composition for water-based paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a hydrazine which gives a film excellent in long-term weather resistance, solvent resistance, water resistance, mechanical properties and the like by baking at room temperature or relatively low temperature. The present invention relates to a resin composition for a water-based coating of a carbonyl group-containing fluorine-containing copolymer containing a series compound.

(Conventional technology and problems to be solved) In recent years, from the standpoint of resource saving, energy saving and de-pollution, conversion from an organic solvent type paint using a large amount of organic solvent to a water-based paint using water as a medium has been actively performed. ing. Among such resins for water-based paints, among others, o / w-type acrylic emulsion resins produced by emulsion polymerization are generally used because they form films at room temperature and form films with relatively good weather resistance. Widely used for

In Japanese Patent Application Laid-Open No. Sho 54-110248, an aqueous emulsion resin has been devised which gives more excellent solvent resistance by utilizing the reaction between a carbonyl group in an acrylic copolymer and a hydrazine compound. However, the aqueous resin composition had insufficient long-term weather resistance.

On the other hand, it has been known that a fluororesin has excellent weather resistance of its film, but it is usually supplied as an aqueous dispersion and requires a high film formation temperature. Further, the fluororesin emulsion described in JP-A-61-261367 can form a film at normal temperature, but has insufficient solvent resistance.

(Means for Solving the Problems) In view of such circumstances, the present inventors have diligently studied to develop an aqueous resin composition that provides excellent long-term weather resistance and solvent resistance at a lower film formation temperature. As a result, the present invention has been achieved.

That is, the present invention relates to a fluorine-containing copolymer having a fluorine atom and a carbonyl group in a molecule, and 0.1 to 10 parts by weight and at least two hydrazine residues per 100 parts by weight of the copolymer. The present invention relates to a resin composition for a water-based paint, comprising an organic hydrazine compound having a group.

 Hereinafter, the present invention will be described in detail.

The fluorine-containing copolymer having a fluorine atom and a carbonyl group in the molecule used in the present invention is a fluoroolefin, a carbonyl group-containing vinyl monomer is a vinyl ether, and optionally a carboxylic acid vinyl ester and / or another vinyl monomer. It is produced by using a monomer.

Examples of the fluoroolefin include vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene, tetrafluoroethylene, 1,1-dichloro-2,2-difluoroethylene, 1-chloro-2,2-difluoroethylene, and 1-chloro- 1,2-difluoroethylene, hexafluoropropylene, 1,1,3,3,3-pentafluoropropylene, 2,3,3,
3-tetrafluoropropylene, 3,3,3-trifluoropropylene, a fluoroolefin such as 1,1,2-trifluoropropylene, preferably tetrafluoroethylene, chlorotrifluoroethylene, one of hexafluoropropylene or Two or more types are mentioned.

As the carbonyl group-containing vinyl monomer, acrolein, diacetone acrylamide, formylstyrene,
Vinyl-alkyl ketones having 4 to 7 carbon atoms,
General formula: Wherein R ¹ is H or CH ₃ , R ² is H or an alkyl group having 1 to 3 carbon atoms, R ³ is an alkyl group having 1 to 3 carbon atoms, and R ⁴ is 1 to 3 Acryl or methacryloxy-alkyl propanal, acrylamidopivalinaldehyde, 3-acrylamidomethyl-
Examples include anisaldehyde, diacetone acrylate, cecetonyl acrylate, diacetone methacrylate, 2-hydroxypropyl acrylate acetyl acetate, butanediol acrylate acetyl acetate, and the like, but are not particularly limited thereto.

Examples of the vinyl ether include cyclohexyl vinyl ether having no functional group, vinyl ether having a linear or branched alkyl group having 2 to 8 carbon atoms, hydroxyethyl vinyl ether having a hydroxyl group, hydroxybutyl vinyl ether, and hydroxyalkyl vinyl ether. Of course, it is not limited to these.

As the carboxylic acid vinyl ester, cyclohexane carboxylic acid vinyl ester, benzoic acid vinyl ester,
p-tert-butyl benzoic acid vinyl ester or C ₁ -C
Esters of ₁₀ aliphatic carboxylic acids are preferred.

Other vinyl monomers include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, acrylic acid 2
Acrylates such as ethylhexyl, lauryl acrylate, tridecyl acrylate, stearyl acrylate, cyclohexyl acrylate, dimethylaminoethyl acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate; methacrylic acid Methyl acrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate,
Stearyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methacryl Methacrylic acid esters such as 2-isocyanate ethyl acid; styrene or substituted styrenes such as vinyltoluene, α-methylstyrene and chlorostyrene; acrylonitrile, methacrylonitrile, vinyl chloride, vinyl formate, vinyl propionate, vinyl stearate, and maleic acid Or monomethacrylate of polyhydric alcohol such as dialkyl acid diester, divinylbenzene, glycerin, trimethylolpropane N- methylolacrylamide,
N-methylol methacrylamide, acrylamide, methacrylamide, acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, general formula For example, CH ₂ = CHCOOCH ₂ CF ₃ CH ₂ = CHCOOCH ₂ CF ₂ CF ₂ H CH ₂ = CHCOOCH ₂ (CF ₂ CF ₂ ) ₂ H CH ₂ = CHCOOCH ₂ (CF ₂ CF ₂ ) ₃ H CH ₂ = CHCOOCH ₂ C ₇ F ₁₅ , CH ₂ = CHCOOCH ₂ CH ₂ C ₈ F ₁₇ , CH ₂ = CHCOOCH ₂ CH ₂ RF (RF; mixture of C ₆ F _{13 to} C ₁₂ F ₂₅ ), and vinyltrichlorosilane And silicon triethylenically unsaturated monomers such as vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane.

In the present invention, in producing the fluorine-containing copolymer, the fluoroolefin is 10 to 60 mol%, the carbonyl group-containing vinyl monomer is 0.1 to 10 mol%, and the vinyl ether is 10 to 85 mol%.
Mol% The vinyl carboxylate and / or other vinyl monomer is used in a proportion of 0 to 70 mol%.

In the present invention, the intended aqueous resin composition of the fluorinated copolymer is prepared by an emulsion polymerization method, or is previously synthesized in a highly hydrophilic organic solvent such as partially soluble in water, and further mixed with water. In general, it is obtained by emulsifying, but is not limited to these techniques.

In the case of production by an emulsion polymerization method, it is common to carry out polymerization by heat or redox decomposition using a radical initiator in the presence of an emulsifier in water or a medium containing water as a main component. At this time, as an emulsifier, an anionic emulsifier such as an alkyl benzene sulfonate, an alkyl naphthalene sulfonate, a higher fatty acid salt, an alkyl sulfate, an alkyl ether sulfate, a phosphate, a perfluoroalkyl fatty acid salt, etc .; Nonionic emulsifiers such as oxide adducts, higher alcohol ethylene oxide adducts, ethylene oxide and propylene oxide block copolymers can be used, and further, polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, sodium polyacrylate, ethylene- A water-soluble polymer such as a maleic anhydride copolymer can be used as a protective colloid.

Potassium persulfate as a radical initiator,
It is carried out by using a water-soluble catalyst such as ammonium persulfate or an oil-soluble catalyst such as benzoyl peroxide or t-butyl perbenzoate alone or in combination with a water-soluble reducing agent such as sodium sulfite, Rongalit, and ascorbic acid.

Such a copolymerization reaction is usually performed at a reaction temperature of 0 to 150 ° C. and a reaction pressure of 1 to 100 kg / cm ² . In addition, a chain transfer agent and a pH buffering agent can be used in some cases.

When the product synthesized in an organic solvent is obtained by emulsifying in water, when emulsifying in water, a method of forcibly emulsifying in the presence of an emulsifier or a water-soluble polymer, or a method of once synthesizing and obtaining a hydrophilic property There is a method of self-emulsifying by introducing a group.

As a method for obtaining a self-emulsifiable fluororesin,
For example, in the presence of a fluorine-containing copolymer (A) having a polymerizable unsaturated double bond in the molecule, in an organic solvent, a monomer mixture containing a vinyl monomer having a carboxyl group is graft-polymerized, Further, there is a method in which a basic compound is added thereto to neutralize the mixture, and then emulsified in water. Examples of the fluorine-containing copolymer (A) include those described in JP-A-57-34107 and JP-A-60-67518, which are soluble in organic solvents containing a functional group such as a hydroxyl group in a molecule. Typical examples are those obtained by reacting a type of fluorine-containing copolymer with a substance having reactivity with the functional group and having a polymerizable unsaturated bond. However, the method is not limited to this method, and any method may be used as long as it is modified so as to be capable of self-emulsification.

As the organic solvent, those having solubility in water can be mainly used, and specific examples thereof include alcohols such as isopropyl alcohol and n-butyl alcohol, ketones such as acetone and methyl ethyl ketone, ethyl acetate, and cellosolve acetate. And ether alcohols such as methyl cellosolve and diethylene glycol monobutyl ether. These organic solvents are
One of these can be used alone, or two or more can be mixed. Usually, after emulsifying the fluorinated copolymer in water, removal under normal pressure or reduced pressure is preferable from the viewpoint of pollution.

In addition, as the carboxyl group-containing vinyl monomer used for the graft polymerization, among the above, acrylic acid and methacrylic acid are typically used, and in some cases, a vinyl monomer other than those is also used as a mixture. Is done.

The graft polymerization is usually performed in the presence of a polymerization initiator. Here, as the polymerization initiator, benzoyl peroxide, peroxide-based radical initiators such as di-tert-butyl peroxide, azobisisobutyronitrile, azo-based radical initiators such as azobisvaleronitrile and the like. Oil-soluble initiators can be used. The polymerization can be carried out under ordinary radical polymerization conditions, preferably at about 80 to 140 ° C for 3 hours.
Done for ~ 10 hours.

As the basic compound, any one may be used as long as it is generally used in aqueous paints. For example, amines such as ammonia, dimethylethanolamine and triethylamine are preferably used. At the time of neutralization, the basic compound is preferably used in an equivalent ratio of 0.5 or more with respect to the charged amount of the carboxyl group-containing vinyl monomer.

The organic hydrazine compound used in the present invention has at least two hydrazine residues in one molecule, specifically, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, Sebacic acid dihydrazide or a polymer having two or more hydrazine residues in a polymer,
For example, polyhydric acid of polyacrylic acid and the like can be mentioned, but it is not particularly limited thereto. The amount of the organic hydrazine-based compound is preferably 0.1 to 10 parts by weight per 100 parts by weight of the fluorinated copolymer. If the amount is less than 0.1 part by weight, the crosslinking point is small and solvent resistance cannot be obtained, and 10
When the amount is more than the weight part, the water resistance of the film may be deteriorated.

The organic hydrazine compound is added after the synthesis of the carbonyl group-containing fluorine-containing copolymer.

In the present invention, the reaction between the carbonyl group in the fluorine-containing copolymer and the organic hydrazine-based compound is not usually performed using a reaction catalyst, but a catalyst such as a water-soluble metal salt may be used in some cases.

The water-based paint resin composition of the present invention has a nonvolatile content of 20 to 65.
It can be used alone as a clear coating in the range of weight%. If necessary, titanium-based, cadmium yellow, inorganic coloring pigments such as carbon black, phthalocyanine-based, organic coloring pigments such as azo-based, calcium carbonate,
Extenders such as talc, pigment dispersants such as sodium tripolyphosphate, sodium polyacrylate or the above-mentioned nonionic emulsifiers, film-forming aids such as butyl carbitol acetate, butyl cellosolve, and thickeners, defoamers, ultraviolet absorbers And an additive such as a light stabilizer, and can be used as an enamel paint.

Paints prepared using the resin composition for water-based paints of the present invention are usually cured at room temperature. However, if necessary, a curing agent such as a melamine compound may be used in combination and used as a baking paint.

(Effects of the Invention) As described above, the resin composition for a water-based paint of the present invention is an epoch-making resin that gives a film-forming mold excellent long-term weather resistance and solvent resistance and sufficiently satisfies low pollution. It is.

 Hereinafter, the present invention will be described in more detail with reference to Examples.

 In the examples, “parts” and “%” are based on weight.

Reference Example 1 In a stainless steel autoclave, 600 parts of deoxygenated water, 3 parts of ammonium perfluorononanoate, 60 parts of trifluorotrichloroethane, 11 parts of disodium phosphate, 0.3 part of ammonium persulfate, and cyclohexyl vinyl ether 55
Parts, 50 parts of ethyl vinyl ether, 15 parts of hydroxybutyl vinyl ether, and 15 parts of diacetone methacrylate.
The thawing operation was repeated twice, and 155 parts of chlorotrifluoroethylene were introduced. The autoclave was gradually heated under stirring and reacted at 60 ° C. for 15 hours to obtain a milky white stable aqueous dispersion (A).

Reference Example 2 In a stainless steel autoclave, 150 parts of deoxygenated water, 2 parts of polyoxyethylene nonylphenyl ether, 3 parts of sodium dodecyl sulfate, 1 part of hydroxyethyl cellulose and 1 part of ammonium hydrogen carbonate, 4 parts of diacetone acrylamide, 30 parts of vinyl pivalate And 1 part of acrylic acid, and then degassed by pressurizing with nitrogen gas. After repeating the operation of pressurizing and degassing with nitrogen twice, ethyl vinyl ether 20
And 45 parts of hexafluoropropylene. 60 ℃
After the temperature was raised, 1 part of ammonium persulfate dissolved in 14 parts of deoxygenated water was added dropwise over 6 hours, and the reaction was further continued for 4 hours to obtain a milky white stable aqueous dispersion (B).

Dimethylethanolamine was added to the aqueous dispersion (B) in an amount of 0.
Eight parts were added, and 30 parts of ethylene glycol monobutyl ether was gradually added with stirring to obtain an aqueous resin liquid (I).

Reference Example 3 In a stainless steel autoclave, 150 parts of deoxygenated water, 0.6 part of ammonium perfluorononanoate, 1.8 parts of disodium phosphate, 0.12 parts of potassium persulfate, 1 part of vinyl benzoate
After charging 3 parts, 2 parts of acrylic acid, and 5 parts of diacetone acrylamide, the mixture was degassed by pressurizing with nitrogen gas. After the operation of pressurizing and degassing with nitrogen was repeated twice, 40 parts of n-butyl vinyl ether and 40 parts of chlorotrifluoroethylene were injected. The reaction was carried out at 70 ° C. for 10 hours to obtain a milky white stable aqueous dispersion (C).

Dimethylethanolamine was added to the aqueous dispersion (C) for 1.
5 parts were added, and 30 parts of ethylene glycol monobutyl ether was gradually added with stirring to obtain an aqueous resin liquid (II).

Reference Example 4 An aqueous resin liquid (III) was obtained in the same manner as in Reference Example 2, except that 20 parts of ethyl vinyl ether was changed to 24 parts and 4 parts of diacetone acrylamide was changed to 0 parts.

Reference Example 5 A glass flask was charged with 840 parts of deoxygenated water, 9 parts of sodium polyoxyethylene alkylphenyl sulfate, and 18 parts of polyoxyethylene nonylphenyl ether.
The temperature was raised to 75 ° C. Add 3 parts of potassium persulfate, 390 parts of methyl methacrylate, 2-ethylhexyl acrylate 1
68 parts, diacetone methacrylamide 30 parts, acrylic acid 12
Parts of the monomer mixture were added dropwise over 3 hours. After completion of the dropwise addition, 60 parts of a 1% aqueous potassium persulfate solution was added, and the mixture was heated to 80 ° C. and aged for 2 hours. After cooling, dimethylethanolamine (12 parts) was added, and ethylene glycol monobutyl ether (180 parts) was gradually added with stirring to obtain an aqueous resin solution (I
V).

Example 1 10 parts of ethylene glycol monobutyl ether was gradually added to 100 parts of the aqueous dispersion (A) under stirring to make the mixture uniform, and then 0.8 parts of oxalic acid dihydrazide was added thereto, followed by sufficient stirring. This was coated on a glass plate with a 10 mil applicator and dried at room temperature for 7 days. A rubbing test was performed on the obtained coating film using gauze impregnated with xylol. Rub the painted surface 10 times and observe the painted surface condition.
I did not see any more. On the other hand, as for the coating film obtained in the same manner as described above unless oxalic acid dihydrazide was added, the coated surface was dissolved in the rubbing test.

Examples 2-3 and Comparative Examples 1-2 Based on the formulations in Table 1, the aqueous resin liquids (I) to (IV)
Was used to prepare the paint.

After adjusting the viscosity of the obtained paint, apply a sealer paint in advance on a straight plate that has been dried, and the film thickness after drying is 30μ.
m and spray dried at room temperature for 2 weeks to obtain a test piece. Table 1 shows the performance of these paints and coatings.
Is shown at the bottom.

As is clear from Table 1, Examples 2 and 3 using the aqueous resin composition of the present invention were very excellent in water resistance, solvent resistance, weather resistance and the like.

On the other hand, Comparative Example 1 using a fluorine-containing resin composition containing no carbonyl group was poor in solvent resistance and water resistance, and Comparative Example 2 using an acrylic resin composition having a carbonyl group.
Had poor weather resistance.

Reference Example 6 98 parts of xylene, 28 parts of ethanol, 1 part of azobisisobutyronitrile, 3 parts of anhydrous potassium carbonate, and 3.3 parts of diacetone methacrylate were charged into a stainless steel autoclave, followed by degassing by pressurizing with nitrogen gas. After repeating the operation of pressurizing and degassing with nitrogen twice, 11.1 parts of cyclohexyl vinyl ether, 9.8 parts of ethyl vinyl ether, 6.5 parts of hydroxybutyl vinyl ether, and 32.7 parts of chlorotrifluoroethylene were introduced. The reaction was carried out at 65 ° C. for 16 hours to obtain a fluorinated copolymer solution (I).

The fluorinated copolymer solution (I) was precipitated in a large excess of heptane, dried, dissolved in methyl cellosolve acetate to a solid content of 60%, 7.1 parts of succinic anhydride was added to 167 parts of the solution,
0.02 parts of triethylbenzylammonium chloride was added, and 10
After reacting at 0 ° C. for 3 hours, 5 parts of dimethylethanolamine was added, and 93.6 parts of water were added to obtain a milky white aqueous resin liquid (V).

Reference Example 7 In the same manner as in Reference Example 6, 490 parts of xylene, 140 parts of ethanol, 5 parts of azobisisobutyronitrile, and 15 parts of anhydrous potassium carbonate were charged into a stainless steel autoclave.
It was pressurized with nitrogen gas and degassed. After repeating the operation of pressurizing and degassing with nitrogen twice, cyclohexyl vinyl ether 90
Parts, n-butyl vinyl ether 85 parts, hydroxybutyl vinyl ether 55 parts, chlorotrifluoroethylene 270
Department was introduced. The reaction was carried out at 65 ° C. for 16 hours to obtain a fluorinated copolymer. This is precipitated in a large excess of heptane,
After drying, it was dissolved in methyl ethyl ketone. Solids concentration 60
% Of the solution prepared in a flask, 280 parts of methyl ethyl ketone, 245.3 parts of methyl methacrylate, 105 parts of n-butyl acrylate, 25.2 parts of acrylic acid, 42 parts of diacetone acrylamide, 2.5 parts of 2-isocyanatoethyl methacrylate, 0.003 parts of dibutyltin dilaurate was added, and the temperature was raised. After the temperature was raised to 70 ° C., 4.2 parts of azobisisobutyronitrile was added, and the mixture was reacted for 4 hours, and further 2.1 parts of azobisisobutyronitrile was added, and the mixture was reacted for 3 hours to obtain a fluorine-containing copolymer solution (II). . During the reaction, the reaction was carried out under a nitrogen stream, and each raw material used was previously dehydrated.

25 parts of dimethylethanolamine was added to the fluorine-containing copolymer solution (II) to make it uniform. Further, 1135 parts of water was gradually added to emulsify the polymer in water. Thereafter, while removing methyl ethyl ketone under reduced pressure, 250 parts of ethylene glycol monobutyl ether was added to obtain an aqueous resin solution (VI). Reference Example 8 Isopropyl alcohol 225 was placed in a glass flask.
And 75 parts of ethylene glycol monobutyl ether, and the temperature was raised to 80 ° C. Azobisisobutyronitrile 0.
5 parts, methyl methacrylate 335 parts, butyl acrylate 150
Parts and 15 parts of acrylic acid were added dropwise over 3 hours. After completion of the dropwise addition, the temperature was raised to 85 ° C., 0.4 parts of azobisisobutyronitrile was added, and the reaction was continued for another 3 hours. After completion of the reaction, 15 parts of dimethylethanolamine was added to make the mixture uniform, and 450 parts of water were gradually added to emulsify the polymer in water to obtain an aqueous resin liquid (VII).

Examples 4 to 5 and Comparative Example 3 Based on the formulations in Table 2, coating materials were prepared using the aqueous resin liquids (V) to (VII).

The obtained paint was spray-coated on a slate plate after adjusting the viscosity so that the film thickness after drying became 30 μm, and dried at room temperature for 1 day and further at 50 ° C. for 8 hours to obtain a test piece. . The performance of these paint films is shown in the lower part of Table 2.

As is clear from Table 2, Examples 4 and 5 using the aqueous resin composition of the present invention were extremely excellent in solvent resistance, weather resistance, and the like.

On the other hand, Comparative Example 3 using the acrylic resin composition having no carbonyl group had poor solvent resistance and poor weather resistance.

Claims (1)

(57) [Claims] 1. A fluorine-containing copolymer having a fluorine atom and a carbonyl group in a molecule, and 0.1 parts by weight based on 100 parts by weight of the copolymer.
An organic hydrazine compound having at least two hydrazine residues in an amount of from 10 to 10 parts by weight.