JPH02286758A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition improved in surface hardness, gloss, solvent resistance, staining resistance, light resistance, nonstickiness, etc., by mixing a film-forming fluororesin modified with a specified modifying agent. CONSTITUTION:A reactive organic functional group-containing fluorine compound of any one of formulas I-III (wherein R is F or CF3; and n is 4-13) or the like is reacted with an organic polyisocyanate (e.g. toluene 2,4-diisocyanate) in the absence or presence of an organic solvent and a catalyst at 0-150 deg.C for 10min to 3hr to obtain a modifying agent having at least one free isocyanate group. 0.0001-1 pt.wt. curing agent (e.g. hexamethylene diisocyanate) is added to 100 pts.wt. coating material obtained by mixing 5-30wt.% this fluororesin with 95-50wt.% solvent and optionally an extender pigment, an organic pigment, a plasticizer, a UV absorber, etc.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a coating composition, and more particularly to a coating composition that is curable at room temperature and forms a coating film with excellent surface properties, particularly a fluorine-containing resin coating. Regarding the composition.

(Prior art and its problems) Conventionally, paints have been applied to the surfaces of various structures, buildings, articles, etc., to prevent corrosion and deterioration of the objects to be coated, and to protect these structures and articles. It is widely used to give a good appearance.

Various types of paints are known as such protective and cosmetic paints, but in recent years, fluorine-containing resin paints have been widely used as paints with excellent durability such as weather resistance and stain resistance. It has become.

However, although fluorine-containing resins inherently have excellent weather resistance, heat resistance, water repellency, chemical resistance, electrical properties, etc., they are not soluble in boat paint solvents, so they are used only for very special purposes. It has been.

In order to solve these drawbacks, recently, fluorine-containing polymers that are soluble in common paint solvents have been developed by copolymerizing fluorine-containing monomers with common monomers, and some of them are used for paints. However, as a result of these resins having a general non-fluorine-containing monomer moiety, it was inevitable that the excellent properties inherent to fluorine-containing resins, such as stain resistance, abrasion resistance, non-adhesiveness, and lubricity, would deteriorate. .

Therefore, the object of the present invention is to provide a copolymer of a fluorine-containing monomer and a non-fluorine-containing monomer, which has good solubility in general paint solvents, yet has various excellent properties inherent to fluorine-containing resins. An object of the present invention is to provide a coating composition that provides a film having the following properties.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention is a reaction product of a fluorine compound having a reactive organic functional group and an organic polyisocyanate, and is a film-forming method using a fluorine-containing resin modified with a modifier having at least one free isocyanate group. This is a coating composition characterized by containing as a component.

(Function) The film-forming fluorine-containing resin is a reaction product of a fluorine compound having a reactive organic functional group and an organic polyisocyanate, and contains a small amount (one free iH (n=4 to 13)). .0:0 to 6, p=o to 3, q=
1 to 3) In the above structural formulas, R represents F or CF.

Although it has good solubility in general paint solvents by being modified with a modifier having a socyanate group,
It is possible to provide a coating composition that provides a film having various excellent properties inherent to fluorine-containing resins.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The modifier used in the present invention and which mainly characterizes the present invention is a reaction product of a fluorine compound having a reactive organic functional group and an organic polyisocyanate, which has at least one free isocyanate group. There is.

Preferred examples of the fluorine compound having a reactive organic functional group used in the present invention include the following compounds.

fil I HCF20F (CF2)nCH20H (n=2 to 10
1(2)I CF3CF(CF2)J2H-OH(n-4 to 13)
The above-mentioned fluorine compounds are preferred examples of fluorine compounds in the present invention, and the present invention is not limited to these examples.The above-mentioned exemplified compounds and other fluorine compounds are currently commercially available. are easily available on the market, and any of them can be used in the present invention.

As the organic polyisocyanate to be reacted with the above-mentioned fluorine compound, any conventionally known organic polyisocyanate can be used, but preferred examples include toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4- Isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether methylene diisocyanate, 4,4-methylenebis(phenylisocyanate) , shrylene diisocyanate, 1.5-naphthalene diisocyanate, benzidine diisocyanate, O-nitrobenzidine diisocyanate, 4.4-dibenzyl diisocyanate, 1.4-tetramethylene diisocyanate, 1.6-tetramethylene diisocyanate, 1.10-deca Methylene diisocyanate, 1.4
-Cyclohexylene diisocyanate, xylylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronac diisocyanate, and the like.

Furthermore, adducts of these organic polyisocyanates and other compounds, such as those of the following structural formula, are also used. Alternatively, these organic polyisocyanates and low molecular weight polyols or polyamines are reacted to form terminal incyanates. Naturally, urethane prepolymers obtained by the above method can also be used.

The modifier used in the present invention is a fluorine compound having a reactive organic functional group as described above and an organic polyisocyanate as described above, in which the organic functional group and incyanate group are incyanate in one molecule. The functional group ratio may be such that there is an excess of one or more groups, preferably 1 to 2 groups, in the presence of an organic solvent and a catalyst, but is not limited thereto.

0 to 150°C, preferably 20 to 8°C, in the absence of
It can be easily obtained by reacting at a temperature of 0° C. for about 10 minutes to 3 hours.

The modifier may be prepared in a solvent or without a solvent, but in terms of process, by preparing it in an organic solvent, the resulting solution can be used as it is for modifying the fluororesin. Therefore, it is advantageous.

Any organic solvent that may be used in the production of such a modifier may be used as long as it is inert to the respective reaction raw materials and products.

Preferred organic solvents include methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate,
Propyl formate, methyl acetate, ethyl acetate, butyl acetate, etc. Also, acetone, cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, toluene, xylene,
Dimethylformamide, dimethyl sulfoxide, perchlorethylene, trichlorethylene, methyl cellosolve, butyl cellosolve, cellosolve acetate, etc. can also be used.

The fluorine-containing resin used as the film-forming resin in the present invention and modified with the above-mentioned modifier has a group that reacts with an isyanate group and is soluble in a solvent. These commercially available fluorine-containing resins can be used in the present invention.

An example of a suitable fluorine-containing resin is a fluorine-containing olefin monomer such as tetrafluoroethylene or trifluorochloroethylene, and a hydroxyl group, a carboxyl group, an amino group,
It is a copolymer with a monomer having a functional group reactive with isocyanate groups, such as an acid anhydride group, an epoxy group, or a thioalcohol group, or it may be one in which these reactive groups are added after copolymerization. . Typical examples of these copolymerizable monomers include vinyl acetate, vinyl ester, (meth)acrylic acid, and various esters thereof, as well as extender pigments, organic pigments, inorganic pigments, other film-forming resins, and plasticizers. ,
An ultraviolet absorber, an antistatic agent, a leveling agent, a curing agent, a catalyst, etc. can be included as necessary.

Other general film-forming resins that may be used in combination include, for example, various conventionally known film-forming resins, and any of these may be used, such as vinyl chloride resins, vinylidene chloride resins, chloride resins, etc. Vinyl/vinyl acetate/vinyl alcohol copolymer resin, acrylic resin, epoxy resin, acrylonitrile-butadiene resin, polyurethane resin, polyurea resin, nitrocellulose resin, polybutyral resin, polyester resin, melamine resin Examples include resins, urea resins, acrylic resins, polyamide resins, etc., and particularly resins having reactive groups capable of reacting with isocyanate groups in their structures are preferably used. These resins can be used alone or as a mixture, and can be used as a solution or dispersion in an organic solvent.

Moreover, various substances can be used as the crosslinking agent or curing agent. Of course, during copolymerization, a third monomer having no reactive group may be copolymerized. The copolymerization ratio of the fluorine-containing monomer and other monomers is such that the resulting copolymer is soluble in general paint solvents. For example, the molar ratio of the fluorine-containing monomer in the copolymer is 30 to 90. A range of % is preferred.

The paint solvent used in the present invention is a solvent commonly used in paints, and includes, for example, the solvents exemplified above.

The coating composition of the present invention has the above-mentioned components as essential components, and their blending ratio is such that the total solid content of the solvent is 5 to 50% by weight, and the film-forming fluorine-containing resin is 10% by weight of the coating material.
It is in the range of about 5 to 30% by weight in 0 parts by weight,
The modifier is used in an amount of 1 to 10 parts per 100 parts by weight of the fluororesin.
A range of 0 parts by weight is preferred. The reaction between the modifier and the fluorine-containing resin may be carried out before or after the preparation of the coating material, and is not particularly limited.

Further, the coating composition of the present invention can be used with other general coatings, but preferred are polyisocyanate compounds such as those mentioned above, particularly non-yellowing diisocyanates such as hexamethylene diisocyanate and inphoron diisocyanate, and adducts thereof. is useful.

When these polyisocyanates are added as a curing agent to make the coating composition of the present invention curable at room temperature, for example, an amine-based or organometallic catalyst may be added in an amount of about 0.0001 to 1 per 100 parts by weight of the coating material. It is preferable to add and mix in parts by weight.

The method for producing the coating composition of the present invention itself may be the same as the conventional technique and is not particularly limited.

(Effects) The paint of the present invention as described above can be applied to steel plates, aluminum plates, aluminum sash, etc., metal structures, glass, cement, inorganic structures such as concrete, wood, FRP, polyethylene, etc.
It is useful for the protection and cosmetic coating of plastic structures such as polypropylene, nylon, polyester, vinyl chloride resin, ethylene vinyl acetate resin, acrylic resin, etc., and has excellent surface hardness, gloss, solvent resistance, stain resistance, light resistance, and A coating film with excellent adhesiveness etc. can be provided.

Such effects are due to the fact that deterioration in various properties of the fluorine-containing resin due to copolymerization with other monomers is compensated for by modification with the fluorine-containing modifier.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. It should be noted that unless otherwise specified, the terms in the text or % are based on weight.

Reference Example 1 (Manufacture of modifier) 71 parts of isophorone diisocyanate and 0.006 parts of dibutyltin dilaurate were added to 221 parts of ethyl acetate.
150 parts of fluoroalcohol having the structure shown below was gradually added dropwise to the mixture while stirring well at a temperature of 0.degree. C. to cause a reaction.

CFa (CF,) 7(:HaCH20H After the reaction is completed, ethyl acetate is removed by evaporation to give a milky white wax-like modifier (
I) 214 parts were obtained.

According to the infrared absorption spectrum of the above modifier, after the reaction was completed, ethyl acetate was removed by evaporation to obtain 308 parts of the modifier (n) in the form of a milky white wax.

According to the infrared absorption spectrum, the above modifier has 2.27
Absorption due to free isocyanate groups was observed at 0 cm-', and an absorption band based on CF2- groups was observed at 1,190 cm-'. Furthermore, when the amount of free incyanate groups in this modifier was quantified, the theoretical value was 4.95%, whereas the actual value was 4.52%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

Reference Example 3 (Production of Modifier) 62 parts of hexamethylene diisocyanate and O,oos parts of dibutyltin dilaurate were added to 272 parts of ethyl acetate, and while stirring well at 80°C, 210 parts of fluoric alcohol having the following structure was gradually added thereto. was added dropwise to cause a reaction.

Absorption due to free isocyanate groups was observed at 2.270 cm-', and an absorption band based on CF2- groups was observed at 1,190 cm-'. Furthermore, when the free incyanate group in this modifier was quantified, the theoretical value was 6.12%.
However, the actual value was 5.80%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

Reference Example 2 (Production of Modifier) Water-added MDI 98 parts and dibutyltin dilaurate 0.0
09 parts were added to 318 parts of ethyl acetate, and while stirring well at 80° C., 220 parts of fluorine alcohol having the following structural formula was gradually added dropwise thereto to react.

After the reaction, ethyl acetate was removed by evaporation to obtain 264 parts of milky white wax-like modifier (III).

According to the infrared absorption spectrum, the above modifier has 2.27
Absorption due to free isocyanate groups was observed at 0 cm-', and an absorption band based on CF2- groups was observed at 1,190 cm-'. Furthermore, when the amount of free isocyanate groups in this modifier was quantified, the theoretical value was 5.73%, but the actual value was 5.21%.

Therefore, the main structure of the above modifier is estimated to be the following formula.

Reference Example 4 (Modification of resin) Fluoroolefin-vinyl ether copolymer resin solution (
Add 5 parts of a modifier (■) to 300 parts (solid content 50%, hydroxyl value 24 mgKOH/g, manufactured by Asahi Glass), and heat at 80°C for 6 hours.
The reaction was carried out for a period of time to obtain a fluorine-containing resin solution modified with a modifier. In this modified resin, no incyanate group was observed by infrared absorption spectrum. This is presumed to be due to graft bonding of the modifier to the resin.

Reference example 5 (modification of resin) Fluoroolefin-vinyl ether copolymer resin solution (
Solid content 60%, hydroxyl value 32 mgKOH/g, manufactured by Asahi Glass) 7 parts of a modifier (■) were added to 300 parts, and the mixture was heated at 80°C for 5 minutes.
The reaction was carried out for a period of time to obtain a fluorine-containing resin solution modified with a modifier. In this modified resin, no isocyanate groups were observed by infrared absorption spectrum. This is presumed to be due to graft bonding of the modifier to the resin.

Reference Example 6 (Modification of resin) Fluoroolefin-vinyl ether copolymer resin solution (
Solid content 50%, hydroxyl value 26 mgKOH/g, manufactured by Asahi Glass), 5 parts modifier (■) was added to 300 parts, and the mixture was heated at 80°C for 4 hours.
Table 1 (Paint composition) Resin 1: Modified resin (solid content 50%) Resin 2;
Unmodified resin (solid content 50%) Titanium oxide: CR-
90 Curing agent: Coronate EH (Nippon Polyurekne fluororesin solution was obtained. In this modified resin, no incyanate group was observed by infrared absorption spectrum. This is presumed to be because the modifier was grafted to the resin. .

Examples 1 to 3 and Comparative Examples 1 to 3 The modified resin solutions of Reference Examples 4 to 6 were made into paints according to the formulations shown in Table 1 below based on a conventional coating method, and applied to a zinc steel plate (treated with phosphoric acid) to a thickness of 25 μm when dry. Apply at a rate of 130℃/
Each film was formed by drying at 1 min and left at 25° C. for 1 day, and the physical properties of each film were measured to obtain the results shown in Table 2 below.

In addition, Comparative Examples 1 to 3 are cases where the fluorine-containing resin solutions used in Reference Examples 4 to 6 before modification were made into paints as they were.

(Margin below) catalyst: made) Dibutyltin dilaurate (modifier) Considering the amount added during production of (Adjusted so that the final amount is the same) 2 tables (Coating film physical properties) Glossy 260° gloss Adhesiveness: Peel off adhesive cellophane tape Stain resistance: Lipstick, crayon: Wipe off with a dry cloth Magic; black and red were used.

*1 - Wipe off with a dry cloth *2 = Wipe off with a mixed solvent of petroleum benzine/ethanol (weight ratio 1/1) Criterion 202: No traces left at all.

O - Slightly marks left × = Surface quality that leaves no marks completely: Water repellency criteria: 0 = Good repellency ○ = Relatively good repellency Falling angle (°): When the coating material is tilted, The angle at which water droplets start to slide (using a contact angle meter from Kyowa Interface Materials ■) Peeling the cellophane tape: Measure the peeling force (g/rrI'') 3 days after crimping JIS C2107 cellophane tape at a constant pressure at 25°C Applicant Dainichiseika Chemical Co., Ltd.

Claims (2)

[Claims] (1) A reaction product of a fluorine compound having a reactive organic functional group and an organic polyisocyanate, which has at least one
1. A coating composition comprising, as a film-forming component, a fluorine-containing resin modified with a modifier having free isocyanate groups. (2) The coating composition according to claim 1, further comprising a curing agent.