JPH03106957A - Fluororesin coating composition - Google Patents

Abstract

PURPOSE:To prepare a fluororesin coating compsn. having an excellent processability and giving a coating film excellent in the weatherability, mechanical properties, adhesive properties, and stain resistance by dissolving two or more specific fluororesins in an org. solvent capable of dissolving the resins. CONSTITUTION:A vinylidene fluoride (co)polymer contg. 80wt.% or higher vinylidene fluoride units and a copolymer comprising a fluorinated vinyl monomer (e.g. chlorotrifluoroethylene), a vinyl monomer (e.g. ethyl vinyl ether or vinyl acetate) and optionally vinylidene fluoride are dissolved in an org. solvent capable of dissolving the two polymers (e.g. diethylene glycol monoethyl acetate).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new and useful fluororesin composition for paints. More specifically, the present invention relates to a resin composite material comprising two specific groups of fluororesins and an organic solvent capable of dissolving both groups of resins, and in particular, a metal plate that can be bent. The present invention relates to a fluororesin composition for paints that can be effectively used for painting, has extremely excellent weather resistance, and also has excellent gloss, processability, and stain resistance. [Conventional technology] Generally speaking, painted metal materials are coated in advance before being processed, such as forming or assembling steel materials. In comparison, it is widely used mainly for various building materials such as roofing materials, exterior wall materials, and duct shutters because it is advantageous in terms of economy, labor saving, and pollution prevention. However, in recent years, there has been an increasing demand for long-term weather resistance for this type of coated metal material.

To meet these demands, paints that use polyvinylidene fluoride as a binder have been used, but polyvinylidene fluoride alone has problems with film transparency and adhesion to materials such as iron. However, some specific acrylic resins have poor paint workability.
It has been used in combination with polyvinylidene fluoride.

However, films obtained from these mixtures cannot meet the above-mentioned requirements for high weather resistance because the acrylic resin impairs the excellent weather resistance characteristic of polyvinylidene fluoride. It was something I couldn't answer.

[Problem to be solved by the invention]

However, the present inventors have solved the problems in the prior art as described above, and also satisfied the requirement of ensuring long-term weather resistance as described above. We have begun intensive research in order to provide an extremely useful fluororesin composite for paints that has excellent adhesion to materials and ease of painting.

Therefore, the problem to be solved by the present invention is to provide an extremely useful fluororesin composition for paints that has at least excellent long-term weather resistance, mechanical properties, adhesion, and stain resistance. It is to provide.

[Means to solve the problem]

Therefore, the present inventors have made extensive studies focusing on the problems that the invention aims to solve as described above, and have found that fluorine-containing vinyl monomers and vinyl compounds can be used as an alternative to acrylic resins. that a copolymer may be used;
In addition, each of these requires an organic solvent that can dissolve both the vinylidene fluoride homopolymer or copolymer and the copolymer of fluorine-containing vinyl monomers and a vinyl compound. By using resin compositions that are included as ingredients, the film has excellent transparency, processability, and painting workability, as well as weather resistance, mechanical properties,
Upon discovering that it is possible to obtain a coating film that is excellent in desired coating film properties such as gloss, adhesion, and stain resistance, the present invention has been completely abandoned.

That is, the present invention includes, as an essential component, a homopolymer or copolymer (A) of vinylidene fluoride containing at least 80% by weight of vinylidene fluoride, and a polymer that may or may not contain vinylidene fluoride. A copolymer (B) of a fluorine-containing vinyl monomer and a vinyl compound copolymerizable with the fluorine-containing vinyl monomer, that is, a fluorine-free vinyl monomer; An object of the present invention is to provide an extremely useful fluororesin composition for coatings, which contains an organic solvent (C) capable of dissolving both polymers (A) and (B), and has the various properties listed above. and
In particular, the vinylidene fluoride homopolymer or copolymer (A) does not completely dissolve in any organic solvent at room temperature and is always dispersed in the organic solvent. % by weight of a vinylidene fluoride homopolymer or copolymer (A), and 15 to 70% by weight of a fluorinated vinyl monomer, which may or may not contain the vinylidene fluoride. , 85 to 30 of other vinyl monomers copolymerizable with the fluorine-containing vinyl monomers.
The copolymer (B) of fluorine-containing vinyl monomers obtained by copolymerizing % by weight and the (co)polymer (A) of vinylidene fluoride do not dissolve at a temperature below 80 ° C. is dissolved at a temperature of 80°C or higher, and an organic solvent (C) that can dissolve the copolymer (B) of the fluorine-containing vinyl monomers at a temperature of 20°C. ) and component (B
) solid content weight ratio: (A)/(B) is 95/5 ~
In a ratio of 2 0/8 0, and component (C),
The object of the present invention is to provide a fluororesin composition for paint, which contains component (A) and component (B) in a ratio of 30 parts by weight or more based on 100 parts by weight of the total solid content.

Here, the above (co)polymer (A) which is the first essential component constituting the fluororesin composite for paint of the present invention is:
It refers to a vinylidene fluoride homopolymer or copolymer containing at least 80% by weight of vinylidene fluoride.

Of course, polyvinylidene fluoride is one such (co)polymer (A), but other monomers copolymerizable with vinylidene fluoride, such as vinyl fluoride,
Typical examples include copolymers with various fluorine-containing α-olefins such as tetrafluoroethylene, chlorotrifluoroethylene, promotrifluoroethylene, pentafluoropropylene, or hexafluoroethylenepropylene.

A typical commercially available product is Kynar (κ).
ynar) 500 J (product of Penn Walt Company, USA) or "FORAFRON CPORAPLO
N) [Showa Denko ■ products] etc. Next, the copolymer (B), which is the second essential component constituting the fluororesin composition for coatings of the present invention, is a fluorine-containing copolymer that may or may not contain vinylidene fluoride. Refers to copolymers of vinyl monomers and fluorine-free vinyl monomers, especially 15 to 7 fluorine-containing vinyl monomers that may or may not contain vinylidene fluoride.
0% by weight of fluorine-containing vinyl monomers and 85 to 30% by weight of fluorine-free vinyl monomers copolymerizable with the fluorine-containing vinyl monomers. It refers to a copolymer.

Among these, such fluorine-containing vinyl monomers may or may not contain vinylidene fluoride,
In addition to various fluorine-containing α-olefins as mentioned above, various perfluoroalkyl perfluorovinyl ethers such as trifluoromethyl vinyl ether, trifluoroethyl vinyl ether, pentafluoroethyl vinyl ether, or hexafluoroprobyl vinyl ether, etc. Typical examples include compounds having a fluorine atom in the main chain, among others, vinyl fluoride, tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, or compounds in which the alkyl group has 1 to 18 carbon atoms. It is particularly desirable to use perfluoroalkyl trifluorovinyl ethers.

Of course, these fluorine-containing vinyl monomers listed above may be used alone or in combination of two or more.

On the other hand, typical vinyl monomers copolymerizable with the above-mentioned fluorine-containing vinyl monomers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isobrobyl vinyl ether, n- −
butyl vinyl ether, isobutyl vinyl ether, t
Alkyl vinyl ethers or substituted alkyl vinyl ethers such as ert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, chloromethyl vinyl ether, chloroethyl vinyl ether, penzyl vinyl ether or phenylethyl vinyl ether: Cycloalkyl vinyl ethers such as cyclobentyl vinyl ether, cyclohexyl vinyl ether; vinyl-2,2-dimethylpropanoate, vinyl-2,2-dimethylbutanoate, vinyl-2,2-dimethyl Pentanoate, vinyl-2.2-
Dimethylhexanoate, diny-2-ethyl-2-methylbutanoate, vinyl-2-ethyl-2-methylbentanoate, vinyl-3-chloro-2.2-dimethylpropanoate, vinyl acetate, propionic acid vinyl, n
Vinyl monobutyrate, vinyl isobutyrate, vinyl caproate, vinyl caprylate, vinyl caprylate, vinyl laurate, C, branched aliphatic vinyl carboxylate, C1. Branched aliphatic vinyl carboxylate of C.I. Vinyl carboxylates such as branched aliphatic vinyl carboxylates or vinyl stearate; vinyl cyclohexanecarboxylate, vinyl methylcyclohexanecarboxylate, vinyl benzoate or p
Vinyl esters of carboxylic acids having a cyclic structure, such as vinyl -tert-butylbenzoate; α-olefins, such as ethylene, propylene or butene-1; fluorine-containing α-olefins, such as vinyl chloride or vinylidene chloride, as listed above. Various halogenated olefins excluding olefins; aromatic vinyl compounds such as styrene, α-methylstyrene or vinyltoluene; acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate or cyclohexyl acrylate; methyl methacrylate, ethyl methacrylate, Methacrylic acid esters such as butyl methacrylate, cyclohexyl methacrylate or pendyl methacrylate; 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxybrobyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxybutyl vinyl ether, - Vinyl ethers having a hydroxyl group such as hydroxy-2-methylpropyl vinyl ether, 5-hydroxybentyl vinyl ether or 6-hydroxyhexyl vinyl ether: vinyltrimethoxysilane, vinyltriethoxysilane, vinyltribroboxysilane, vinylmethyldiethoxy Silane, Vinyltris(β-methoxyethoxy)silane, Allyltrimethoxysilane, Trimethoxysilylethyl vinyl ether, Triethoxysilylethyl vinyl ether, Methyldimethoxysilylethyl vinyl ether, Trimethoxysilylbropyruvinyl ether, Triethoxysilylbutylvinyl ether, Methyldimethoxysilane Ethoxysilylbrobyl vinyl ether, T-(meth)acryloyloxypropyltrimethoxysilane,
Monomers containing hydrolyzable silyl groups such as γ-(meth)acryloyloxyprobyltriethoxysilane or r-(meth)acryloyloxypropylmethyldimethoxysilane; N-dimethylanoethyl(meth)acrylamide, N - Amino group-containing ξ-do-based unsaturated monomers such as diethylaminoethyl (meth)acrylamide, N-dimethylaminopropyl (meth)acrylamide or N-diethylaminopropyl (meth)acrylic acid; dimethylanoethyl (meth) Acrylate or dialkyl ξnoalkyl (meth)acrylate such as diethylaminoethyl (meth)acrylate} W4
: Such as tert-butylaminoethyl (meth)acrylate, tert-butylaminobutyl (meth)acrylate, aziridinylethyl (meth)acrylate, pyrrolidinylethyl (meth)acrylate or biveridinylethyl (meth)acrylate. Amino group-containing monomers: or carboxyl group-containing monomers such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid or fumaric acid.

Among the various copolymerizable monomers listed above, from the viewpoint of increasing the polymerization yield of the copolymer (B) component,
From the viewpoint of increasing the solubility of the copolymer (B) component in organic solvents, it is desirable to use alkyl vinyl ethers, cycloalkyl vinyl ethers, and carboxylic acid vinyl esters. The copolymer (B) is obtained from each of the fluorine-containing vinyl monomers listed above and other fluorine-free vinyl monomers copolymerizable with the fluorine-containing vinyl monomer. In order to prepare fluorine-containing vinyl tn-mers, the content should be controlled to be within a range of 15 to 70% by weight, preferably 20 to 60% by weight.

If it is less than 15% by weight, the weather resistance of the resulting coating film will inevitably decrease, while if it exceeds 70% by weight, the copolymer (B)
, containing 80% by weight or more of the above-mentioned vinylidene fluoride,
When the fluororesin composition for paint of the present invention is prepared by mixing with vinylidene fluoride homopolymer or copolymer (A), this resin set t? ．． In either case, the solubility of the substance in organic solvents decreases.
Undesirable.

Particularly desirable as the copolymer (B) are:
Copolymerizable with 15 to 70% by weight of the fluorine-containing vinyl monomers and at least one selected from the group consisting of alkyl vinyl ethers, cycloalkyl vinyl ethers, and carboxylic acid vinyl esters. It is obtained by copolymerizing 85 to 30% by weight of other vinyl monomers.

Of course, when vinylidene fluoride is also used to prepare the copolymer (B), this vinylidene fluoride is
The amount of fluorine-containing vinyl monomers used is 15 as described above.
It is selected and determined as appropriate within the range of 70% by weight. The copolymer (B) itself is preferably soluble in an organic solvent at a temperature of 20°C. The copolymer (
B) is prepared by polymerizing the various monomers listed above in the presence of a radical polymerization initiator using known and commonly used polymerization methods such as bulk polymerization, solution (pressure) polymerization, suspension polymerization, or emulsion polymerization. Copolymerization may be carried out using a solution radical polymerization method, but it is most convenient to use a solution radical polymerization method.

The radical polymerization initiators used in this case include ace, tilver oxide, penzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, te
r t-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl peroxybenzoate, Lert-butyl peroxyoctoate, tert-butyl peroxy acetate or Typical examples include peroxides such as tert-butylperoxybiparate; or azo compounds such as azobisisobutyronitrile or azobisisovaleronitrile. In addition, the solvent used during such polymerization includes at least one organic solvent (C) which is the third essential component in the present invention, as described below, and furthermore,
Hydrocarbon systems such as toluene, xylene, cyclohexane, n-hexane or n-octane; Ester systems such as ethyl acetate or n-butyl acetate; Amide systems such as dimethylformamide, dimethylacetate or N-methylpyrrolidone. ; or methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert
- the organic solvent (C), such as an alcohol based such as butanol or ethylene glycol monoalkyl ether;
It may also contain at least one type of solvent other than the above.

The copolymer (B) thus obtained has a weight average molecular weight of 20. It is desirable that the number be managed within the range of 000 to 300,000.

If it is less than 20,000, the weather resistance of the coating film will inevitably deteriorate; on the other hand, if it is less than 300.0
If it exceeds 00, painting workability etc. inevitably deteriorate, so either case is not preferable.

Furthermore, the organic solvent (C), which is the third essential component constituting the fluororesin composition for paints of the present invention, is a material that is It does not melt at a temperature of do.

Specific examples of the organic solvent (C) include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl amyl ketone, diacetone alcohol, isophorone, mesityl oxide, or 4-methoxy-4-methylpentanone-2: Aliphatic or aromatic alkyl or alkoxy esters such as dimethyl succinate, dimethyl adipate, dimethyl sebacate, dimethyl phthalate, 2-methoxyethyl acetate, 2-ptoxyethyl acetate or dimethoxyethyl phthalate; diethylene glycol monoethyl ether Glycol ethers or esters such as acetate or diethylene glycol monobutyl ether acetate; cyclic ethers such as dioxane or tetrahydrofuran; carbonates such as ethylene carbonate or brobylene carbonate; lactones such as butyrolactone; Examples include nitroalkanes such as nitropropane or nitromethane.

In particular, the solvent group (C) that gives favorable results includes esters such as dibasic acid alkyl esters represented by dimethyl succinate or dimethyl phthalate; ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, or diethylene glycol. Organic solvents including glycol ethers such as monobutyl ether acetate; or ketones such as acetone, isophorone or diacetone alcohol. By the way, when a single solvent is used, it is difficult to obtain paints and coatings that have good workability and cosmetic properties. Therefore, in practical terms, it is difficult to achieve the above-mentioned good results. It is necessary to use at least two kinds of organic solvents called solvent (C) in appropriate combination, and at least one of them should be used in combination with the above-mentioned organic solvent (C). It is necessary to make a selection so that the

One or more, preferably two or more, of the above-mentioned solvents (C) group that produce good results are used as polymerization solvents during the preparation of the above-mentioned copolymer (B). Although it is preferable to use it, there is absolutely no problem in using it in the production of paints.

In making the paint, in addition to the above-mentioned organic solvent (C), if necessary, toluene, xylene, ethyl acetate, or acetic acid monomer, such as those already listed as solvents other than the organic solvent (C), may be used. - Even if an organic solvent such as butyl is present, there is no problem; in fact, it is desirable from the viewpoint of adjusting the viscosity of the paint.

Each of the vinylidene fluoride containing at least 80% by weight of vinylidene fluoride (
Co)polymer (A), fluorine-containing vinyl monomers that may or may not contain vinylidene fluoride, and other fluorine-free monomers copolymerizable with the fluorine-containing vinyl monomers. By mixing and dispersing the copolymer (B) with vinyl monomers and an organic solvent (C) as essential components according to a conventional method, the desired fluororesin composition for paints of the present invention is prepared. You can get the bottom stuff.

At that time, the solid content weight ratio of component (A) and component (B): (A)/(B) is preferably in the range of 95/5 to 20/80, preferably 90/10 to 30/ It is preferable to manage it so that it falls within a range of 7.0.

If component (B) is used in too large a quantity exceeding this ratio, the mechanical properties, etc. will inevitably deteriorate, while on the other hand, if component (B) is used in too small a quantity exceeding such ratio. In such cases, the solubility or dispersibility in organic solvents inevitably decreases, which in turn leads to a decrease in coating workability, which is undesirable in either case.

The amount of organic solvent (C) used is at least 30 parts by weight based on 100 parts by weight of the total solid content of components (A) and (B).

If the amount is less than 30 parts, (A)
This is undesirable because it tends to interfere with the solubility of the components at temperatures above 80°C, and as a result, it becomes difficult to obtain a cosmetic coating. The thus-obtained composition of the present invention is usually used with the addition of a pigment, but it goes without saying that there is no problem even if no colorant component is used.

Typical such pigments include titanium oxide, zinc white, carbon black, iron black, copper chromium black, and copper.
Iron/manganese black, yellow lead, cadmium yellow, ocher, titanium yellow zinc chromate, Bengara, zinc/iron brown, cadmium red, chrome vermilion, manganese violet, deep blue, ultramarine, cobalt blue, chrome green, chromium oxide green , titanium/cobalt/nickel/zinc green, viridian, cobalt green, emerald green, kaolin, bentonite, silica white, alumina white, gypsum, chalk,
Inorganic pigments such as precipitated barium sulfate, precipitated calcium carbonate or barite; β-naphthol type, β-oxynaphthoic acid type, naphthol As type, pyrazolone type,
Organic head such as acetoacetanilide series, acetoacetate series, phthalocyanine series, anthraquinone series, indigo series, perylene series, purinone series, dioxazine series, quinacridone series, isoindolinone series, metal complex salt series, fluorobin series or quinophthalone series Materials; metal powders such as brass powder, silver powder, gold powder, aluminum powder, or copper powder; or scaly mica treated with titanium oxide.

The materials of the present invention may further include various resins and solvents, fluidity regulators, color separation inhibitors, antioxidants, ultraviolet absorbers, light stabilizers, or silane coupling agents, as necessary. It is of course possible to add various known and commonly used additives such as.

Among these additive components, representative resins include cellulose resins such as nitrocellulose and cellulose acetate butyrate, as well as vinyl chloride and
Examples include vinyl acetate copolymer resin, petroleum resin, ketone resin, oil-free alkyd resin or epoxy resin.

The fluororesin for paints of the present invention can be applied to various materials or processed products, such as metals and inorganic base materials, by a known and commonly used method such as spray coating, brush coating, roll coating, or impregnation coating. and 180-3
Drying is carried out at a temperature of about 00°C for about 5 to 40 minutes to provide a coating film with excellent performance. [Effects of the Invention] The fluororesin composition for paints of the present invention provides a coating film with excellent long-term weather resistance, mechanical properties, adhesion and stain resistance, and moreover, The composition of the present invention itself has excellent processability and painting workability, and furthermore, the film has excellent transparency. Therefore, the fluororesin composition for paint of the present invention can be widely used mainly for various building materials such as roofing materials, exterior wall materials, ducts, and shutters.

〔Example〕

Next, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified.

Reference Examples 1 to 3 [Combination of fluorine-containing vinyl monomers that may or may not contain vinylidene fluoride and other vinyl monomers that are copolymerizable with the fluorine-containing vinyl monomers] Preparation Example of Polymer (B)] In a 2-liter stainless steel autoclave that was sufficiently purged with nitrogen, fluorine-containing vinyl monomer M (vinylidene fluoride) was added among the various raw material components shown in Table 1. ), that is, fluorine-free copolymerizable vinyl monomers, and organic solvents other than xylene are compressed, and while stirring, The reaction was carried out by holding at 60°C for 15 hours, and the nonvolatile content was 67%.
At this point, it was cooled to room temperature and 495 parts of xylene was added to obtain a solution of the desired copolymer (B) having a non-volatile content and a weight average molecular weight as shown in the same table. Ta.

/ Examples 1 to 4 and Comparative Examples 1 and 2 A (co)polymer (A) of vinylidene fluoride as shown in Table 2,
Each copolymer (B) obtained in Reference Examples 1 to 3,
Blend with organic solvent (C) in a predetermined weight ratio, further add a predetermined amount of Rn material shown in the same table, and according to a conventional method,
A white paint was obtained by kneading and dispersing.

However, in Comparative Example 1, no copolymer (B) was used at all, and instead, methyl methacrylate/ethyl acrylate copolymer was used, and in Comparative Example 2, is a (co)polymer of vinylidene fluoride (
This example is a comparative example to Example 2 in that the organic solvent (C) was less than 30 parts with respect to 100 parts of the total solid content of A) and the copolymer (B).

Next, each paint was diluted with a diluting solvent and 0.3f
Dry film thickness is 35-40μ on fIIm thick galvanized copper plate
m, and then baked in a baking drying oven at 210 m.
A dry coating was obtained by baking for 20 minutes at °C.

A comparative study of the various properties of each coating film was conducted, and the results shown in the same table were obtained.

Note that the evaluation of various performances was performed in the following manner.

Weather resistance: 6,00
0 hours lI! The gloss retention rate after conducting the in-test was expressed.

Gloss: 60° specular reflectance measured with a Murakami gloss meter.

Yuichi / / As is clear from the results in Table 2, the fluororesin composition for paints of the present invention provides a coating film with excellent weather resistance and gloss, and is extremely useful. I know it's something.

teenager Reason Man

Claims (1)

[Scope of Claims] 1. A vinylidene fluoride homopolymer or copolymer (A) containing at least 80% by weight of vinylidene fluoride;
A copolymer of a fluorine-containing vinyl monomer and a vinyl monomer, which may or may not contain vinylidene fluoride (
A fluororesin composition for paint, comprising B) and an organic solvent (C) capable of dissolving both the polymers (A) and (B). 2. Containing at least 80% by weight of vinylidene fluoride;
A vinylidene fluoride homopolymer or copolymer (A), 15 to 70% by weight of a fluorine-containing vinyl monomer that may or may not contain vinylidene fluoride, and the fluorine-containing A copolymer (B) of fluorine-containing vinyl monomers obtained by copolymerizing the vinyl monomers with 85 to 30% by weight of other copolymerizable vinyl monomers; A vinylidene fluoride homopolymer or copolymer (A),
An organic solvent that does not dissolve at a temperature of less than 80°C, but dissolves at a temperature of 80°C or higher, and can dissolve the copolymer (B) of the fluorine-containing vinyl monomers at a temperature of 20°C.
C) and solid content weight ratio of component (A) and component (B):
At a ratio of (A)/(B) from 95/5 to 20/80,
Moreover, the fluororesin composition for paints comprises component (C) in a proportion of 30 parts by weight or more based on 100 parts by weight of the total solid content of component (A) and component (B). 3. Vinylidene fluoride homopolymer or copolymer (A) containing at least 80% by weight of vinylidene fluoride
Claim 1 or 2 is in a state of being dispersed in an organic solvent.
The fluororesin composition for paints described in .