JPH06228488A - Composition for fluorine-based coating - Google Patents

Abstract

PURPOSE:To obtain a composition, comprising phosphorous acid esters blended in a fluorine-based coating composition consisting essentially of a fluoroolefinic copolymer containing carboxylic acid group, excellent in storage stability, weather and heat resistance and surface glossiness and useful for automobiles, etc. CONSTITUTION:The composition is obtained by blending (B) preferably 0.01-10 pts.wt. phosphorous acid esters such as phosphorous acid triester or diester based on (A) 100 pts.wt. fluoroolefinic copolymer containing carboxylic acid group therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorine coating composition.

[0002]

2. Description of the Related Art A coating material containing a solvent-soluble fluoroolefin copolymer as a main component has excellent properties such as weather resistance, chemical resistance, heat resistance and surface gloss. Development is progressing in a wide range of fields, such as heavy corrosion protection, and its usage is steadily increasing. As such a fluoroolefin copolymer, a fluoroolefin copolymer containing a hydroxyl group is often used. Further, a fluoroolefin copolymer containing a carboxylic acid group has recently been attracting attention for the purpose of improving the dispersibility of the pigment and the curing reactivity. However, a varnish in which a fluoroolefin copolymer containing a carboxylic acid group is dissolved in a solvent may have increased viscosity or yellowing during long-term storage.

Further, for the purpose of improving the storage stability of a varnish in which a fluoroolefin copolymer is dissolved in a solvent,
A method of adding a tertiary amine to a varnish has been proposed (Japanese Patent Laid-Open No. 60-28458), but the addition of an amine was not sufficient because it resulted in an undesirable result of yellowing of the varnish.

Further, a method of compounding an epoxy group-containing compound with a varnish has been proposed (JP-A-2-202942).
However, if the addition of an epoxy group-containing compound reduces the dispersibility of the pigment and the adhesion to the substrate due to the reaction with the carboxyl group or amino group contained in the varnish or the coating additive during long-term storage. There was, and was insufficient.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have earnestly studied to obtain a coating composition containing a fluoroolefin copolymer containing a carboxylic acid group as a main component, which has improved the above-mentioned problems. The present invention has been completed by finding a composition for a fluorine-based coating composition that can be used for a room-temperature-curable fluorine-based coating composition in which the increase in viscosity is remarkably improved and the varnish is not yellowed.

[0006]

The present invention has been made to solve the above-mentioned problems, and provides a composition for a fluorine-based coating material containing a fluoroolefin copolymer containing a carboxylic acid group as a main component. The present invention provides a composition for a fluorine-based coating material, which is characterized by containing phosphite esters.

In the present invention, it is important that phosphite ester is blended. Here, the phosphorous acid ester is an ester of phosphorous acid represented by the general formula (1) or the general formula (2).

[0008]

[Chemical 1]

[Chemical 2]

Further, the phosphite ester is preferably an alkyl ester, a phenyl ester or a derivative thereof, and may be a monoester, a diester or a triester, but is a diester or a triester. Is preferred. Moreover, you may use the compound which has a phosphorus atom which comprises 2 or more phosphite ester in a molecule.

Specifically, di2-ethylhexyl phosphite, diphenyl phosphite, triphenyl phosphite, phenyl neopentyl phosphite, diphenyl decyl phosphite, phenyl diisodecyl phosphite, diphenyl isooctyl phosphite, trilauryl phosphite, Examples thereof include tris (nonylphenyl) phosphite, hydrogenated bisphenol A phosphite resin, bisphenol A tetraalkyldiphosphite, trilauryltrithiophosphite, and the compounds shown in the following chemical formulas 3 to 16.

[0011]

[Chemical 3]

[Chemical 4]

[0012]

[Chemical 5]

[Chemical 6]

[0013]

[Chemical 7]

[Chemical 8]

[0014]

[Chemical 9]

[Chemical 10]

[0015]

[Chemical 11]

[Chemical 12]

[0016]

[Chemical 13]

[Chemical 14]

[0017]

[Chemical 15]

[Chemical 16]

Examples of the raw material for the fluoroolefin unit of the fluoroolefin copolymer containing a carboxylic acid group in the present invention include, for example, tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, hexafluoropropylene and pentafluoro. Propylene or the like can be used and can be appropriately selected depending on the properties required for the coating film, the combination with the copolymer component or the curing agent. Moreover, these fluoroolefins can use 1 type (s) or 2 or more types.

Further, the carboxylic acid group is obtained by copolymerizing a monomer containing a carboxylic acid group (JP-A-2-58555,
(JP-A-63-152677, etc.) or a hydroxyl group-containing fluoroolefin copolymer is reacted with a polyvalent carboxylic acid anhydride to form a carboxylic acid (JP-A-58).
-136605, etc.) and the like.

The raw material for the hydroxyl group-containing unit of the hydroxyl group-containing fluoroolefin copolymer is a double monomer which is a monomer having a hydroxyl group or a group capable of being converted into a hydroxyl group and which is copolymerizable with a fluoroolefin. Those having a bond can be used, for example, hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hdoxybutyl vinyl ether, hydroxyisobutyl vinyl ether and hydroxycyclohexyl vinyl ether,
Vinyl hydroxyacetate, vinyl hydroxypropionate, vinyl hydroxybutyrate, vinyl hydroxyvalerate,
Esters of hydroxyalkyl carboxylic acids such as vinyl hydroxyisobutyrate and vinyl hydroxycyclohexanecarboxylate with vinyl alcohol, hydroxyethyl allyl ether, hydroxypropyl allyl ether, hydroxybutyl allyl ether, hydroxyisobutyl allyl ether, hydroxy cyclohexyl allyl ether, etc. Hydroxyalkyl allyl ethers such as hydroxyalkyl allyl ether, hydroxyethyl allyl ester, hydroxypropyl allyl ester, hydroxybutyl allyl ester, hydroxyisobutyl allyl ester, hydroxycyclohexyl allyl ester, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2- Hydroxyethyl methacrylate, hydro And like hydroxyalkyl esters of acrylic acid or methacrylic acid such as shea methacrylate, also, such as those partially fluorine-substituted compounds. As the raw material for the hydroxyl group-containing unit, one or more of these may be selected and used. Further, it is desirable to use a vinyl-based or allyl-based compound because of its copolymerizability with fluoroolefin.

In addition to the above-mentioned two units, the fluoroolefin copolymer used in the present invention can lower the melting point or glass transition point of the fluoroolefin copolymer to further improve the coating workability. A copolymerizable comonomer can be copolymerized with the above-mentioned two components depending on the purpose of imparting appropriate hardness, flexibility, gloss and other physical properties to the film.

As such a comonomer, one having an unsaturated group active to the extent that it can be copolymerized with a fluoroolefin and not significantly impairing the weather resistance of the coating film is adopted. Usually, an ethylenically unsaturated compound, For example, ethyl vinyl ether,
Alkyl vinyl ethers such as propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether and cyclohexyl vinyl ether, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl valerate and vinyl cyclohexanecarboxylate, and esters of vinyl alcohol with vinyl alcohol , Alkyl allyl ethers such as ethyl allyl ether, propyl allyl ether, butyl allyl ether, isobutyl allyl ether, cyclohexyl allyl ether, alkyl allyl ethers such as ethyl allyl ester, propyl allyl ester, butyl allyl ester, isobutyl allyl ester, cyclohexyl allyl ester, etc. Allyl esters, alkenes such as ethylene, propylene, butylene, isobutylene, acrylic acid, Methacrylic acid or ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, propyl methacrylate,
Butyl methacrylate, isobutyl methacrylate, 2
Examples thereof include esters of acrylic acid or methacrylic acid such as ethylhexyl methacrylate, and partially fluorine-substituted compounds thereof.

These comonomers may be used alone or in combination of two or more. Further, as the comonomer, vinyl type, allyl type compounds or alkenes having excellent copolymerizability with fluoroolefin are preferably used. When a vinyl-based or allyl-based alkyl ester or alkyl ether is used, the alkyl group has 2 to 10 carbon atoms.
It is preferably a linear, branched or alicyclic alkyl group having a certain degree. Further, the fluoroolefin copolymer used in the present invention, in addition to the carboxylic acid group, a group capable of reacting with an isocyanate group, a group for improving pigment dispersibility,
For example, it may have a hydroxyl group, an epoxy group, an amino group, or the like. The fluorine-containing copolymer having these groups can be produced by modification such as copolymerization of monomers having these groups.

The fluoroolefin copolymer used in the present invention must have a fluorine content of 10% by weight or more. Usually, this fluorine content is related to the composition ratio of the fluoroolefin unit in the fluoroolefin copolymer. However, it is also possible to increase or decrease this content by polymer reaction once the copolymer is produced.

When the fluorine content of the fluoroolefin copolymer used in the present invention is less than 10% by weight, a coating film having sufficient weather resistance cannot be obtained. The fluorine content in the copolymer is preferably 15 to 72% by weight in view of the overall balance of performance such as weather resistance of coating film and coating workability.

The fluoroolefin copolymer used in the present invention has a fluorine content of 10% by weight or more,
In addition, 30 to 70 mol% of fluoroolefin unit
What is contained in the range of can be used especially preferably. That is, the fluoroolefin unit is 30 mol%
When it is more than the above, the weather resistance is further remarkably improved, and when the fluoroolefin unit is 70 mol% or less, the fluoroolefin copolymer is likely to be amorphous, that is, the fluoroolefin copolymer is less likely to be crystalline, It is particularly preferable because it has good adhesion and facilitates the formation of a coating film having a uniform and smooth surface.

The fluoroolefin copolymer in the present invention can be synthesized by a conventionally known method. Polymerization can be carried out by allowing a polymerization initiator to act on a monomer mixture in a predetermined ratio in the presence or absence of a catalyst. Further, it can be produced by any method of solution polymerization, emulsion polymerization and suspension polymerization.

The coating composition of the present invention preferably contains 0.01 to 10 parts by weight of the phosphite compound per 100 parts by weight of the fluoroolefin copolymer. If the blending amount of the phosphite compound is too small, it is difficult to sufficiently achieve the effect of storage stability. Good storage stability is achieved when the amount is at least about 0.01 part by weight. In addition, if a too large amount is blended, not only a synergistic effect is not recognized, but also other performance may be adversely affected, which is not preferable. Sufficient effects can be obtained by blending at most about 10 parts by weight, so blending more than this is not only unnecessary but also economically undesirable.

The composition of the present invention is preferably one in which the above fluoroolefin copolymer and phosphite are dissolved or dispersed in an organic solvent. As such an organic solvent, most of those generally used as a solvent for paints can be used. Further, the composition of the present invention may be further added with various additives such as an ultraviolet absorber, a pigment, a leveling agent and a curing agent, and a polymer other than the fluoroolefin copolymer, such as an acrylic polymer, may be added. It may be blended.

[0030]

【Example】

Example 1 A stainless steel pressure-resistant reactor equipped with a stirrer having an internal volume of 300 cc, 157 g of t-butanol, 16 g of cyclohexyl vinyl ether (CHVE), and isobutyl vinyl ether (i
BVE) 9 g, hydroxybutyl vinyl ether (HB
25 g of VE), 1 g of potassium carbonate and 0.07 g of azobisisobutyronitrile (AIBN) are charged, and the dissolved air is removed by solidification degassing with liquid nitrogen. After that,
50 g of chlorotrifluoroethylene (CTFE) is introduced, and the temperature is gradually raised. Then, the temperature is maintained at 65 ° C., the reaction is continued under stirring, and after 10 hours, the reactor is water-cooled to stop the reaction. After cooling to room temperature, unreacted monomer is extracted and the reactor is opened. The composition of the obtained copolymer was almost the same as the monomer composition. After removing the dispersion medium from this polymerization reaction solution, it was dissolved in xylene to obtain a xylene solution having a concentration of 50%. 100 g of xylene solution of this copolymer
0.45 g of succinic anhydride was reacted in a 200 ml eggplant type flask equipped with a stirrer at 90 ° C. for 6 hours to obtain a polymer xylene solution having a polymer acid value of 4.8 mg KOH / g.

To 100 g of this xylene solution, 0.5 g of MARK PEP-36 manufactured by ADEKA ARGUS was added and sufficiently stirred. The coating composition thus obtained was placed in a glass bottle, sealed, and then kept at 70 ° C. to track the change in viscosity. No increase in viscosity was observed even after 20 days, and the initial viscosity remained. Also, the acid value was almost equivalent to 4.7 mgKOH / g. In addition, MARK PE made by ADEKA ARGUS
P-36 is a compound represented by the following chemical formula 17.

[0032]

[Chemical 17]

Example 2 The procedure of Example 1 was repeated except that MARK 517 manufactured by ADEKA ARGUS was used in place of MARK PEP-36, and the viscosity change was traced at 70 ° C. even after 20 days. No increase in viscosity was observed and the initial viscosity remained. Also, the acid value was almost equivalent to 4.7 mgKOH / g. In addition, MARK5 made by ADEKA ARGUS
17 is a compound represented by the following chemical formula 18.

[0034]

[Chemical 18]

Comparative Example 1 In Example 1, the xylene solution was used as it was instead of the MARK PEP-36, and everything else was the same as in Example 1, and the change in viscosity was traced by keeping it at 70 ° C. The initial viscosity was 3 times the initial viscosity, and gelation occurred on the 7th day.

[0036]

EFFECT OF THE INVENTION The composition of the present invention, which comprises a fluoroolefin copolymer having a carboxylic acid group and a phosphite ester compound, has excellent storage stability and weather resistance. It has the feature that it can provide very excellent raw materials.

Claims (3)

[Claims] 1. A fluorine-containing coating composition comprising a fluorine-containing coating composition containing a fluoroolefin copolymer having a carboxylic acid group as a main component and phosphorous acid esters. 2. The fluorine-containing coating composition according to claim 1, wherein 0.01 to 10 parts by weight of the phosphite ester is mixed with 100 parts by weight of the fluoroolefin copolymer. 3. The fluorine-containing coating composition according to claim 1, wherein the phosphite ester is phosphite triester or phosphite diester.