JPH0657196A - Fluorine-containing coating polymer composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a coating composition excellent in resistance to repeated hot and cold action without impairing the weather resistance and stain resistance originally possessed by a fluorine-containing coating. [Structure] A vinylidene fluoride-based copolymer (A) and a hydroxyl group-containing methacrylate-based copolymer (B) are included as polymer components, and a curing agent and a solvent are included. The weight ratio (A) / (B) of the copolymer (A) and the copolymer (B) is 15/85 to 90/10. The hydroxyl group-containing methacrylate copolymer (B) has a hydroxyl value of 5 to 80 mgKOH / g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composition for a fluorine-containing coating which is excellent in weather resistance, resistance to repeated hot and cold action, and stain resistance (stain removal property).

[0002]

2. Description of the Related Art Vinylidene fluoride-based paints and fluorinated ethylene vinyl ether-based paints can be cited as commonly used room-temperature-drying paints. These paints are used for buildings and structures where concrete is the object to be coated. It is mainly used as paint for automobiles.

However, of these, the vinylidene fluoride-based paint is a non-crosslinking type, and the molecular weight of the polymer contained in the paint cannot be increased, so that it is an important performance required especially in cold regions. It has a low resistance to repeated actions and has the drawback that the coating film tends to crack. Further, although the fluorinated ethylene vinyl ether-based paint is a paint having excellent weather resistance, it has a drawback that it is easily soiled and the cosmetic appearance, which is one of the functions required for the paint, is significantly impaired.

Further, in Japanese Patent Laid-Open No. 63-89559,
A curable resin composition containing a fluoroolfine polymer and a hydrolyzable silyl group-containing acrylic polymer as essential components is described. However, the composition described in the publication has the drawbacks that it tends to gel due to the water adsorbed on the pigment, the water in the air, etc., and the stain resistance is poor.

[0005]

DISCLOSURE OF THE INVENTION The present invention overcomes the problems of the prior art described above, and has excellent resistance to repeated hot and cold action without impairing the weather resistance and stain resistance originally possessed by the fluorine-containing paint. An object is to provide a coating composition.

[0006]

Means for Solving the Problems The polymer composition for a fluorine-containing coating material of the present invention contains a vinylidene fluoride copolymer (A) and a hydroxyl group-containing methacrylate copolymer (B) as polymer components, And a curing agent and a solvent, the weight ratio (A) / (B) of the copolymer (A) and the copolymer (B) is 15/85 to 90/10, and the hydroxyl group is The hydroxyl value of the contained methacrylate-based copolymer (B) is 5 to 80 mgKOH / g.

The present invention will be described in detail below.

The polymer component of the vinylidene fluoride copolymer (A) used in the present invention is a homopolymer of vinylidene fluoride, or vinylidene fluoride and vinyl fluoride, trifluoroethylene, tetrafluoroethylene, bromotriene. Fluoroethylene, chlorotrifluoroethylene,
It is a copolymer obtained by polymerizing at least one fluoroolefin monomer selected from pentafluoropropylene, hexafluoropropylene, perfluoroalkyl, trifluoroalkyl, trifluorovinyl ether and the like. As the copolymer (A),
Preferred is a terpolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene. In this ternary copolymer, the proportion of vinylidene fluoride is preferably 10 to 99% by weight with respect to the whole monomer.
And more preferably 40 to 90% by weight.

The hydroxyl group-containing methacrylate type copolymer (B) used in the present invention is a vinyl type monomer having a hydroxyl group in the methacrylate type monomer as a main component and, if necessary, other vinyl type monomer. It is a copolymerized body.

Examples of the methacrylate monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate and methacrylic acid 2. Examples thereof include methacrylic acid esters such as ethylhexyl and cyclohexyl methacrylate. The amount of the methacrylate-based monomer used is preferably 59 to 99% by weight, more preferably 70 to 99% by weight, based on the total amount of the monomers used for the polymerization of the methacrylate-based copolymer (B). If the amount of the methacrylate-based monomer is less than 59% by weight, the compatibility with the vinylidene fluoride-based copolymer (A) becomes poor, which is not preferable.

Examples of the vinyl monomer having a hydroxyl group include 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate and the like.

Other monomers which can be copolymerized with the methacrylate type monomer include, for example, methyl acrylate,
Examples thereof include acrylic acid esters such as ethyl acrylate, n-propyl acrylate, n-butyl acrylate, and cyclohexyl acrylate, or styrene, vinyltoluene, vinyl oxide, acrylonitrile, and the like.

The amount of hydroxyl groups contained in the copolymer (B) is 5 to 8 as the hydroxyl value of the methacrylate copolymer.
0 mgKOH / g, in particular, the amount of hydroxyl group is 20 to 60
When it is mgKOH / g, the compatibility with the vinylidene fluoride-based copolymer (A) and the crosslinking action are good. If the hydroxyl value is less than 5 mgKOH / g, crosslinking will be insufficient,
On the other hand, when the hydroxyl value exceeds 80 mgKOH / g, the compatibility with the vinylidene fluoride copolymer (A) becomes poor.

The molecular weights of the vinylidene fluoride copolymer (A) and the hydroxyl group-containing methacrylate copolymer (B) are polystyrene-converted number average molecular weights, preferably 2,000 to 50,000, and more preferably It is 5,000 to 20,000.

The above-mentioned copolymer (A) and copolymer (B)
The amount used is 15/8 by weight ratio (A) / (B) of both.
It is 5 to 90/10, preferably 50/50 to 80/20. If the weight ratio is less than 40/60, the weather resistance is poor, and if the weight ratio is more than 80/20, the effect of crosslinking cannot be sufficiently obtained.

In the present invention, a curing agent is used.
The curing agent is not particularly limited as long as it reacts with a hydroxyl group, but in the case of a room temperature dry type coating composition, urethane crosslinking with an isocyanate compound is preferable.

Typical examples of a polyisocyanate compound used as a curing agent include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI) and naphthylene diisocyanate ( ND
I), paraphenylene diisocyanate (PPDI),
Tetramethylxylylene diisocyanate (TMXD
I), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI),
Lysine isocyanate (LDI), isopropylidene bis (4-cyclohexyl isocyanate) (IPC),
Examples thereof include hydrogenated xylylene diisocyanate (H ₆ XDI), cyclohexyl diisocyanate (CHPI), isophorone diisocyanate (IPDI), and burette and isocyanurate conjugates of the above polyisocyanates, and adducts thereof.

As specific examples of the adducts of these polyisocyanates, burettes and isocyanurates, the TDI adducts include Coronate L (Nippon Polyurethane Industry Co., Ltd.) and Sumi. Joule L-75 (Sumitomo Bayer Urethane Co., Ltd.), Takenate D-103H (Takeda Pharmaceutical Co., Ltd.), Barnock D-750 (Dainippon Ink and Chemicals Co., Ltd.), Mitec GP302A (Mitsubishi Kasei Co., Ltd.) )), P49-75S (Mitsui Toatsu Kogyo Co., Ltd.), H
As an adduct of DI, Coronate HL (Nippon Polyurethane Industry Co., Ltd.), Sumidule HT (Sumitomo Bayer Urethane Co., Ltd.), Takenate D-160N (Takeda Pharmaceutical Co., Ltd.), Barnock D-950 (Dainippon Daini) Ink Chemical Industry Co., Ltd., NP2000 (Mitsui Toatsu Kogyo Co., Ltd.), and IPDI adducts, Takenate D-140N (Takeda Pharmaceutical Co., Ltd.), Mitec NY
215A (Mitsubishi Kasei Kogyo Co., Ltd.), as an XDI adduct, Takenate D-110N (Takeda Pharmaceutical Co., Ltd.), as TMXDI adduct, Takenate D-181N (Takeda Pharmaceutical Co., Ltd.), Takenate D-120N (Takeda Pharmaceutical Co., Ltd.) is used as the H ₆ XDI adduct, and Coronate 2061 (Nippon Polyurethane Industry Co., Ltd.) and Desmodur HL (Sumitomo Bayer Urethane Co., Ltd.) are used as the TDI burette. )), HD
As the burette body of I, Sumidur N-320
0 (Sumitomo Bayer Urethane Co., Ltd.), Sumijour N-
75 (Sumitomo Bayer Urethane Co., Ltd.), Takenate D-
165N90CX (Takeda Pharmaceutical Co., Ltd.) and TDI isocyanurates include Coronate 2030 (Nippon Polyurethane Industry Co., Ltd.), Sumijour IL (Sumitomo Bayer Urethane Co., Ltd.), Takenate D-204 (Takeda Pharmaceutical Co., Ltd. Co., Ltd.), Barnock D-800 (Dainippon Ink and Chemicals, Inc.), Mitec GP-750A (Mitsubishi Kasei Co., Ltd.), HDI isocyanurate, Coronate EH (Nippon Polyurethane Industry Co., Ltd.). ),
Desmodur N-3390 (Sumitomo Bayer Urethane Co., Ltd.), Takenate D-170N (Takeda Pharmaceutical Co., Ltd.), Vernock DN980 (Dainippon Ink and Chemicals, Inc.), as the isocyanurate form of IPDI,
Desmodur Z-4370 (Sumitomo Bayer Urethane Co., Ltd.) and the like can be mentioned.

Of these polyisocyanates, polyisocyanate adducts, burette binders, isocyanurate binders and blocked isocyanates, among the polyisocyanates, there are no yellowing type or hardly yellowing type in terms of weather resistance. Is preferred.

Further, in order to react these polyisocyanate compounds with the hydroxyl groups in the (meth) acrylic compound more quickly, monoamines, diamines, triamines, cyclic amines, alcohol amines, ether amines, etc. An amine-based catalyst or an organometallic catalyst such as dibutyltin dilaurate or dibutyltin dialate may be added.

Examples of the curing agent include aminoplast compounds such as melamine, benzoguanamine and urea, in addition to the above isocyanate compounds. This aminoplast compound also includes those obtained by converting melamine, urea, and benzoguanamine into methylol, and further etherifying with a fatty alcohol. Such compounds include:
Specific examples thereof include hexamethylolmelamine, methylolated urea, methylolated benzoguanamine, and butylated melamine, butylated urea, butylated benzoguanamine obtained by butation of these. Among these, a melamine-based aminoplast compound is preferable from the viewpoint of weather resistance, and a hexamethylol-melamine which is a non-associated monomer is preferable from the viewpoint of compatibility.

The amount of the curing agent added is the ratio of the number of moles of hydroxyl groups contained in the methacrylate-based copolymer to the number of moles of functional groups in the curing agent (the number of hydroxyl groups: the number of moles of functional groups in the curing agent). Is 1: 0.5 to 1: 2, preferably 1: 0.
8 to 1: 1.2. In mixing these curing agents,
When the curing reaction of the composition proceeds at room temperature due to the addition of the curing agent during storage, it is preferably added immediately before using the composition of the present invention. For example, polyisocyanate is preferably added immediately before use, and melamine and blocked isocyanate can be stored while being added.

As the solvent which can be used in the present invention, an organic solvent such as an aliphatic or alicyclic ketone-based, ester-based or ether-based solvent can be used.
Among these, it is preferable to include an organic solvent having a boiling point of 100 ° C. or more in order to form a smooth coating film. For example, as the ketone type, methyl n-propyl ketone, diethyl ketone, methyl isobutyl ketone, methyl n-butyl ketone. , Ethyl n-butyl ketone, methyl n-amyl ketone, diisobutyl ketone, methyl n-hexyl ketone,
Mesityl oxide, cyclohexanone, diacetone alcohol, methylphenol ketone, isophorone; ester systems include n-propyl acetate, n-butyl acetate, isobutyl acetate, 2-methoxyethyl acetate,
Amyl acetate, dimethyl adipate, dimethyl glutarate, dimethyl succinate; as ether type, propylene glycol such as methyl cellosolve, 2-methoxy-2-propanol cellosolve, 1-ethoxy-2-propanolbutyl cellosolve, and 1,4-dioxane. Examples thereof include monomethyl ether acetate.

The solid content concentration of the polymer composition for a fluorine-containing coating material of the present invention is usually 10 to 70% by weight, preferably 20 to 60% by weight.

Further, the viscosity of the composition of the present invention is usually 1
It is 0 to 10,000 cps.

The polymer composition for fluorine-containing paint of the present invention comprises
It can be suitably used as a room-temperature-drying type paint, and can also be used as a baking paint. This polymer composition is particularly useful as a concrete wall paint for buildings and structures, but also other metal building materials such as sashes and carte walls, structures such as tanks, chimneys and bridges, furniture, home appliances, vehicles. It can also be used as a paint.

Further, the polymer composition for a fluorine-containing coating material of the present invention contains, if necessary, organic or inorganic pigments, ultraviolet absorbers, antioxidants, wetting and dispersing agents, defoaming agents, anti-sagging agents, Leveling agents, matting agents and the like can be used.

[0028]

EXAMPLES Next, the present invention will be described in more detail by showing Examples and Comparative Examples of the present invention. (Example 1) A vinylidene fluoride-based polymer having a monomer composition of 50% by weight of vinylidene fluoride, 40% by weight of tetrafluoroethylene and 10% by weight of hexafluoropropylene, and having a polystyrene equivalent number average molecular weight of 30,000 of the polymer. A copolymer containing 21 g of a copolymer, a monomer composition of 76% by weight of methyl methacrylate, 10% by weight of ethyl methacrylate and 14% by weight of 2-hydroxyethyl methacrylate, and a hydroxyl group-containing methacrylate copolymer having a hydroxyl value of 60 mgKOH / g. 14 g of the polymer was dissolved in 65 g of methyl isobutyl ketone solvent, and 1.5 g of a wetting dispersant (amine type) and 20 g of titanium oxide were dispersed in this solution.

To this, Takenate D-14 was used as a curing agent.
4.8 g of 0N and 0.12 g of dibutyltin laurate as a curing catalyst were added and well stirred to obtain a coating composition of the present invention. A slate plate (70 mm × 1) coated with an acrylic elastic paint with a film thickness of about 1 mm was applied to this coating composition.
50 mm × 3 mm) was applied by a spray method and cured at room temperature for 7 days. As a result, a sample having a coating layer with a film thickness of 40 μm was obtained.

The samples obtained were evaluated by the following tests. (1) Resistance to repeated hot and cold action According to JIS K 6910, the coating film surface of the sample after the test was visually observed, and the result was evaluated as follows.

◯: No abnormality

X: There is a crack. (2) Stain resistance Carbon powder (Mitsubishi Diamond Black # 4 manufactured by Mitsubishi Kasei Co., Ltd.)
4 ink) and kerosene were mixed in a weight ratio of 1: 2, and the mixture was applied evenly on the surface of the coating film of the sample.
After leaving for 4 hours, the contaminants were washed with a neutral detergent with water, and the stain removal was examined visually and by the color difference (ΔE), and evaluated as follows. The color difference (ΔE) is measured by a color difference meter.

◯: The stain was completely removed. (0 ≦ ΔE <1) Δ: Stain remains slightly and color difference is recognized. (1 ≦ △ E <
3) ×: A lot of dirt remains and it looks dark. (3 ≦ ΔE) (3) Accelerated weathering resistance According to the sunshine carbon arc lamp method of JIS K 5400 accelerated weathering resistance test, the coating film of the sample was examined by the gloss retention rate (GR) at 1000 hours of exposure. Was evaluated as follows.

◯; G. R. ≧ 80% Δ; 80> G. R. ≧ 60% ×; G.I. R. <60% Results are shown in Table 1.

[Table 1] According to this example, resistance to repeated hot and cold action,
Good results were obtained in terms of both stain resistance and accelerated weather resistance. (Example 2) In the coating composition obtained in Example 1, 10% by weight of ethyl methacrylate, which is a monomer component of the hydroxyl group-containing methacrylate copolymer, was changed to 10% by weight of cyclohexyl methacrylate for copolymerization. 1% of the hydroxyl group-containing methacrylate copolymer (hydroxyl value 60 mgKOH / g)
A coating composition was prepared in the same manner as in Example 1 except that 4 g was used, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

Similar to Example 1, this Example was excellent in resistance to repeated hot and cold actions and stain resistance, and was slightly better in accelerated weathering resistance than Example 1. (Example 3) As in Example 1, except that 50 g of the vinylidene fluoride-based copolymer used in Example 1 and 50 g of the hydroxyl group-containing methacrylate-based copolymer of Example 1 were used and the ratio of both was changed. A coating composition was prepared and evaluated in the same manner as in the examples. The results are shown in Table 1.

Also in this example, it was possible to obtain a coating excellent in resistance to repeated hot and cold actions, stain resistance and accelerated weathering resistance. (Comparative Example 1) Example 1 except that a curing agent and a curing catalyst were not used.
A coating composition was prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 1.

In this comparative example, resistance to repeated hot and cold action was particularly poor. (Comparative Example 2) Vinylidene fluoride-based copolymer 1 of Example 1
A coating composition was prepared in the same manner as in Example 1 except that 0 g and 25 g of the hydroxyl group-containing methacrylate copolymer of Example 1 were used and evaluated in the same manner as in Example 1. The results are shown in Table 1.

In this comparative example, the stain resistance and accelerated weather resistance were particularly poor. (Comparative Example 3) Vinylidene fluoride-based copolymer 3 of Example 1
A coating composition was prepared in the same manner as in Example 1 except that 1.5 g and 3.5 g of the hydroxyl group-containing methacrylate copolymer of Example 1 were used and evaluated in the same manner as in Example 1. The results are shown in Table 1.

In this comparative example, the resistance to repeated hot and cold repeated actions was particularly poor. (Comparative Example 4) Vinylidene fluoride-based copolymer 3 of Example 1
1.5 g and monomer composition of methyl methacrylate 8.9
%, Ethyl methacrylate 10% by weight, 2-hydroxyethyl methacrylate 1% by weight, and a hydroxyl group-containing methacrylate polymer 14 g having a hydroxyl value of 4.3 mgKOH / g is dissolved in 65 g of methyl isobutyl ketone solvent, Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

In this comparative example, since the hydroxyl value was insufficient and the crosslinking was insufficient, the cycle of heating and cooling was poor. (Comparative Example 5) Vinylidene fluoride-based copolymer 3 of Example 1
1.5 g and monomer composition: 67% by weight of methyl methacrylate, 10% by weight of ethyl methacrylate, 2-methacrylic acid
Hydroxyethyl 2.3% by weight, hydroxyl value 9
14 g of the hydroxyl group-containing methacrylate polymer of 9 mg KOH / g was dissolved in 65 g of methyl isobutyl ketone solvent, but the compatibility of both polymers was poor and the solution was completely clouded, so evaluation was not possible. (Comparative Example 6) A methacrylic copolymer obtained by copolymerizing a hydrolyzable silyl group was polymerized and evaluated.

That is, 31.5 g of the vinylidene fluoride copolymer of Example 1 and 76% by weight of methyl methacrylate, 14% by weight of 2-hydroxyethyl methacrylate and γ-methacryloyloxypropyltriene as a monomer composition. Dissolve 14 g of a hydroxyl group-containing methacrylylate copolymer having a hydroxyl value of 60 mgKOH / g and consisting of 10% by weight of methoxysilane in 65 g of methyl isobutyl ketone solvent, and further adding 15 g of a wetting dispersant and 20 g of titanium oxide, Dispersed in a media mill.

4.8 g of a curing agent was added in the same manner as in Example 1.
A coating composition was obtained by addition. Using this, a sample was formed in the same manner as in Example 1 and the physical properties of the coating film were evaluated.
The results are shown in Table 1.

In this comparative example, as a result of introducing a silyl group into the copolymer, the stain resistance was poor. (Comparative Example 7) A coating composition was formed without adding a curing agent to a composition using the same hydrolyzable silyl group-introduced methacrylic copolymer as in Comparative Example 4 to obtain coating film physical properties of Examples. It evaluated similarly to 1. The results are shown in Table 1.

In this comparative example, the resistance to repeated heat and cold and the stain resistance were poor.

[0045]

EFFECTS OF THE INVENTION According to the present invention, since the vinylidene fluoride copolymer and the hydroxyl group-containing methacrylate copolymer having a specific hydroxyl value are contained as the polymer component, the weather resistance originally possessed by the fluorine-containing paint is improved. Further, it is possible to provide a coating composition excellent in resistance to repeated hot and cold actions without impairing stain resistance.

Claims (1)

[Claims] 1. A vinylidene fluoride copolymer (A) and a hydroxyl group-containing methacrylate copolymer (B) as polymer components, and a curing agent and a solvent.
The weight ratio (A) / (B) of the copolymer (A) to the copolymer (B) is 15/85 to 90/10, and the hydroxyl group-containing methacrylate copolymer (B) is A polymer composition for a fluorine-containing coating material, which has a hydroxyl value of 5 to 80 mgKOH / g.