JPH0475266B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a composite film that imparts water and oil repellency, stain resistance, and low friction properties to the surface of the paint film obtained from paints such as air-drying lacquers and baking enamels, and at the same time improves the adhesion of the paint film to the base. Regarding compositions, more specifically, hydrophobic graft polymers containing fluorine or silicone in the molecular chain and hydrophilic polymers containing carboxyl groups in the molecular chain are added to organic solvent solutions of film-forming resins such as air-drying lacquers and baking enamels. The present invention relates to a coating composition with improved surface and adhesion properties of a coating film formed by dissolving a graft polymer. In recent years, there has been a strong interest in saving energy and resources, and there are great expectations for the emergence of higher-performance paints, especially those that impart water and oil repellency, stain resistance, and low friction properties to the coating surface. Purpose: Various methods have also been studied for the purpose of improving the adhesion of the paint film to the substrate. Regarding the improvement of the coating surface, for example, radiation,
Graft polymerization of monomers on the coating surface using light or plasma irradiation, coating the coating surface with coupling agents such as oligomers, polymers, or silane, and adding polymers with low surface energy such as silicone resins and fluorine resins to the coating. There are methods being used to do so. Among these methods, graft polymerization of monomers on the coating surface by radiation, light, or plasma irradiation requires special equipment, and coatings with improved surfaces are expensive. In the method of coating the surface of the paint film with a coupling agent, the modification of the surface of the paint film is temporary and the modification effect on the surface of the paint film does not last, the coated substance is easily removed, and it is thin. It is difficult to create a coating film and there are many problems. There is also a method of adding low surface energy polymers such as silicone resins and fluorine resins to paints.
The sustainability of the modification effect on the surface of the paint film is never satisfactory, and in order to maintain a sufficient modification effect on the surface of the paint film, a large amount of addition is required, which may impair the original performance of the paint film. do. In particular, the adhesion between the paint film and the base becomes poor. On the other hand, in order to improve the adhesion of the paint film to the substrate, the use of primers, the addition of special adhesion improvers to the paint, etc. are being carried out. In the method of using a primer, it is necessary to develop a primer that is suitable for the paint used and the base used, and if the primer is not used in an appropriate manner, adhesive strength between the paint film and the base may not be obtained. In particular, the increase in the primer treatment process on the underlying surface is costly.
It leads to up. In the method of adding special adhesion improvers to paints, it is first necessary to select an adhesion improver that is appropriate for the intended paint and substrate, and it is also necessary to add a relatively large amount to obtain sufficient adhesion. This may even impair the original performance of the coating film. The present invention has been achieved as a result of extensive research in view of these prior art techniques. That is, the present invention is an improved coating composition prepared by dissolving the following hydrophobic graft polymer and hydrophilic graft polymer in an organic solvent solution of a film-forming resin that is highly compatible with some of the constituent components thereof. Hydrophobic graft polymer: A graft polymer consisting of a polymer unit whose main component is a fluorine-containing monomer unit and a polymer unit whose main component is a methyl methacrylate monomer unit, a silicone unit, and a methyl methacrylate monomer unit. A graft polymer consisting of a polymer unit whose main component is a monomer unit, or a graft polymer consisting of a silicone unit and a polymer unit whose main components are an acrylic acid ester monomer unit and a styrene monomer unit. Hydrophilic graft polymer: A graft polymer consisting of a polymer unit consisting of a carboxyl group-containing monomer unit and another vinyl monomer unit, and a polymer unit containing a methyl methacrylate monomer unit as a main component. The present invention is a polymeric additive that has an excellent effect of modifying the coating film surface obtained with organic solvent-based paints such as air-drying lacquers and baking-type enamels and has a long-lasting effect. Hydrophobic graft polymers with a special structure consisting of an anchor moiety that is compatible with film-forming resins (hereinafter referred to as paint polymers) in organic solvent-based paints are useful, and are effective in adhesion to the base of the paint film and its properties. This is based on the fact that hydrophilic graft polymers with a special structure consisting of a part with a carboxyl group and an anchor part that is compatible with the paint polymer are useful as polymer additives with excellent persistence. It was. The present invention uses hydrophobic graft polymers and hydrophilic graft polymers that have the same component as the paint polymer or a part that is compatible with the paint polymer as an anchor moiety to organic solvent-based paints (typical examples include air-drying lacquer and baked-on paints). It is added and dissolved in small amounts to coating compositions such as mold enamels, and imparts excellent water and oil repellency, stain resistance, and low friction properties to the coating surface without impairing the original performance of the resulting coating film. At the same time, the adhesion between the paint film and the substrate is significantly improved, and the presence of the anchor portion allows the concentrated graft polymer to migrate to the paint film surface and the underlying surface of the paint film, and is easily removed from the paint film surface and the underlying surface of the paint film. It maintains the modification effect on the surface of the coating film and the underlying surface of the coating film without detaching. In order to modify the surface of the coating film obtained from the improved coating composition of the present invention and the substrate surface of the coating film (improving the adhesion between the coating film and the substrate), it is necessary to It is important to create an environment suitable for migration and concentration of the hydrophilic graft polymer to the underlying surface of the paint film, but the paint film surface may be in contact with normal air; Materials used in ordinary paints such as metals, ceramics, highly polar plastics, and wood are sufficient for the coating base. That is, by applying the coating composition of the present invention to a polar base, allowing the solvent to evaporate into the atmosphere, and then carrying out an appropriate crosslinking reaction if necessary, the resulting coating film will be able to be exposed to air. Hydrophobic graft polymers are concentrated on the surface, exhibiting excellent water and oil repellency, stain resistance, and low friction. At the same time, hydrophilic graft polymers are concentrated on the back side of the paint film, which is in contact with the paint base. The adhesion of the substrate is significantly improved. Next, the film-forming resin, that is, the coating polymer used in the present invention will be explained. The coating polymer used in the present invention is a polymer mainly composed of methyl methacrylate monomer units or a polymer consisting of (meth)acrylic acid ester monomer units and styrene monomer units. is a good paint polymer, specifically (meta)
Examples include acrylic paint resins, alkyd resins, and epoxy resins containing acrylic acid ester monomer units as a main component. Forming the resin for the above acrylic paint (meth)
Examples of acrylic esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, octyl (meth)acrylate,
(meth)acrylic acid 2-ethylhexyl, (meth)
(meth)acrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate; Comonomers include styrene, acrylonitrile, vinylidene chloride, vinyl acetate, (meth)acrylic acid, maleic acid, (meth)acrylamide,
Examples include N-methylolacrylamide and itaconic acid. Ethyl cellulose, butyl cellulose,
Air-drying lacquers may be prepared by the combined use of cellulose derivatives such as nitrocellulose, benzylcellulose, and cellulose acetate;
Plasticizers such as butylbenzyl phthalate, butyl octyl phthalate, butyl carbitol acetate, antifoaming agents, leveling agents, etc. are sometimes used in combination with ordinary paints. In addition, organic solvent-based paints include baking-type paints containing aminoplast resins and crosslinkable polymers containing functional monomers such as hydroxyalkyl esters of (meth)acrylic acid and alkoxymethyl acrylamide, and carboxylic acid and amino ester paints. Preferably used are baking-type paints in which a polyfunctional epoxy resin is blended with a crosslinkable polymer, and two-component resin paints in which a diisocyanate resin is blended in a crosslinkable polymer containing a hydroxyalkyl ester. Furthermore, these organic solvent-based paints may be colored with inorganic pigments such as titanium oxide, clay, calcium carbonate, chromic acid, strontium, red iron, or organic pigments such as phthalocyanine blue or phthalocyanine green. Methods for synthesizing the hydrophobic and hydrophilic graft polymers used in the present invention include conventionally known chain transfer methods, radiation grafting methods, mechanical or organic chemical reaction methods, polymer initiator methods, and prepolymer bonding methods. , and the macromonomer method, which has recently been attracting attention, can all be preferably used. Regarding the synthesis of the hydrophobic graft polymer preferably used in the present invention, the hydrophobic graft polymer contained in the fluorine molecular chain can be synthesized by the macromonomer method. For example, methyl methacrylate is synthesized in the coexistence of thioglycolic acid. A one-end carboxylic acid prepolymer having a molecular weight of 1,000 to 10,000 is obtained by radical polymerization, and this is reacted with glycidyl methacrylate to produce a macromonomer having a methacrylic acid ester type terminal group. For this macromonomer, fluoroacrylate (CF ₃ −(CF ₂ ) _o −CH ₂ CH ₂
If OCOCH=CH ₂ , a mixture of n=4 to 12) is used, a graft polymer can be obtained in which the trunk is a hydrophobic component and the branches are polymethyl methacrylate. Furthermore, as a method for synthesizing a hydrophobic graft polymer having silicone as a constituent unit, several methods that have been proposed in the past can be used. For example, as seen in Japanese Patent Publication No. 32-6896, Japanese Patent Publication No. 47-16199, and Japanese Patent Application Laid-open No. 48-28389,
A method of obtaining a silicone-based graft polymer by forming an active group by abstracting hydrogen from a lower alkyl group bonded to a silicon atom of silicone and grafting an organic polymer onto the active group, as described in Japanese Patent Publication No. 46-9355. A method for obtaining a silicone-based graft polymer by reacting a silicone having the above with a living polymer obtained by anionic polymerization, a method for synthesizing a polysiloxane polyester containing maleic acid in the main chain, as described in Japanese Patent Publication No. 135391/1983. γ-methacryloxypropyl per mole of α-ω-dihydroxydimethylpolysiloxane, which is then graft-polymerized by mixing maleic acid with a potential-donating monomer that easily forms a charge transfer complex to obtain a silicone-based graft polymer. A method of obtaining a silicone graft polymer by radical copolymerization of an acrylic-modified silicone obtained by a condensation reaction from 0.25 to 1 mole of methyldichlorosilane and a monomer having radical polymerization ability (hereinafter referred to as a method of radical copolymerization of an acrylic-modified silicone and a monomer). Among these manufacturing methods, acrylic-modified silicone and monomer are known as methods for producing silicone-based graft polymers that have excellent solubility in organic solvents and are effective in modifying the coating surface. The method using radical copolymerization is superior. The fluorine or silicone content in these hydrophobic graft polymers is
It is preferable to synthesize so that the amount is 10 to 80% by weight, preferably 20 to 70% by weight. (Here, the fluorine content in the hydrophobic graft polymer is the amount of fluorine-containing monomer according to the NMR spectrum of the fluorine-based graft polymer (for example, see Reference Example 2 for the amount of fluoroalkyl acrylate),
The silicone content is an analytical value determined by firing the silicone-based graft polymer and converting the silicone into SiO ₂ . ) Fluorine or silicone content
If a hydrophobic graft polymer containing less than 10% by weight is used in the coating composition, the surface modification effect of the resulting coating film will not be sufficiently exhibited; When a graft polymer is used in a coating composition, its solubility in organic solvents is poor, and furthermore, the resulting hydrophobic graft polymer is expensive. This is because most of the cost of raw materials for the hydrophobic graft polymer used in the present invention is accounted for by the price of raw materials containing fluorine and silicone. The silicone-based graft polymer copolymer obtained in this way is a graft copolymer with a polymer obtained from a radically polymerizable monomer as the trunk and silicone as branches, and the number of branch points is determined by It can be determined from the molecular weight of the acrylic-modified silicone, the molecular weight of the radically weighted monomer, the molecular weight of the silicone-based graft copolymer, and the silicone content in the silicone-based graft copolymer. On the other hand, the macromonomer method is particularly useful as a method for synthesizing the hydrophilic graft polymer preferably used in the present invention. The use of acids yields graft polymers with hydrophilic components in the trunk and polymethyl methacrylate in the branches. As the monomer having a carboxyl group, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, etc. can be used. These can be used alone or in combination of two or more. Among these monomers having a carboxyl group, acrylic acid and methacrylic acid are particularly preferred. When acrylic acid or methacrylic acid is used as a monomer providing a carboxyl group, the amount of carboxyl groups in the hydrophilic graft polymer is 3 to 80% by weight, preferably 5 to 80% by weight.
50% by weight. If a hydrophilic graft polymer containing less than 3% by weight of acrylic acid or methacrylic acid is used in a coating composition, the excellent adhesion effect between the coating film and the base can no longer be expected. The use of hydrophilic graft polymers in amounts greater than 80% by weight in the coating composition results in poor solubility in organic solvents. These hydrophobic graft polymers and hydrophilic graft polymers whose trunks or branches are made of polymethyl methacrylate can be used to improve the surface of coating films obtained with organic solvent-based paints containing polymethyl methacrylate as a main component or one component. It is not only effective in improving the adhesion between the paint film and the base, but also improves the adhesion between the paint film and the base by modifying the surface of the paint film and improving the adhesion between the paint film and the base by using epoxy resin-based organic solvent-based paints that have an affinity with polymethyl methacrylate. It is also effective for improvement. The amount of the hydrophobic graft polymer used in the present invention added to the organic solvent-based paint is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the nonvolatile content (solid content) of the organic solvent-based paint. It is valid. Addition amount of hydrophobic graft polymer is 0.01
If the coating composition is less than % by weight, the surface modification effect of the resulting coating film will not be sufficiently exhibited, and the surface modification effect (water repellency/ Regarding the relationship between oil repellency, stain resistance, and low friction properties, when the amount of the hydrophobic graft polymer exceeds a few percent by weight, the surface modification effect does not improve much and becomes a nearly constant value. Furthermore, adding a large amount of hydrophobic graft polymer adversely affects the inherent performance of the coating film and increases costs. Therefore, the upper limit of the amount of hydrophobic graft polymer added to the coating composition is 10% by weight based on the nonvolatile content of the organic solvent-based coating. Methods for adding hydrophobic graft polymers to organic solvent-based paints include adding the hydrophobic graft polymer directly to organic solvent-based paints, dissolving the hydrophobic graft polymer in an appropriate solvent, and adding the resulting solution to organic solvent-based paints. Any method may be used, such as adding to. At the same time, the amount of the hydrophilic graft polymer added to the organic solvent-based paint is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the nonvolatile content of the organic solvent-based paint. If the amount of hydrophilic graft polymer added is less than 0.01% by weight, sufficient adhesion between the coating film and the substrate cannot be obtained;
If it exceeds 10% by weight, the original performance of the coating film will be affected and the cost will increase, so the upper limit for the amount of hydrophilic graft polymer added to organic solvent-based paints is 10% by weight based on the non-volatile content of organic solvent-based paints. %. The hydrophilic graft polymer can be added to the organic solvent-based paint by any of the following methods, such as direct addition or addition of a solution obtained by dissolving it in an appropriate solvent, as in the case of the hydrophobic graft polymer. The coating composition of the present invention thus obtained can be preferably used for commonly used coating materials such as metals, ceramics, wood, and polar plastics. As mentioned above, a very small amount of hydrophobic graft polymer imparts water and oil repellency, stain resistance, and low friction properties to the coating surface, and a very small amount of hydrophilic graft polymer improves the adhesion of the coating film to the substrate. A coating composition which is significantly improved and has excellent durability of the modification effect on the coating surface and excellent adhesion to the substrate without impairing the original performance of the coating film is provided. The effect of modifying the surface of the coating film by using the hydrophobic graft polymer and the hydrophilic graft polymer together is superior to the effect of modifying the surface of the coating film when the same amount of hydrophobic graft polymer is simply used. In other words, even in the present invention, the amount of the hydrophobic graft polymer used may be smaller in order to obtain the same surface modification effect as that obtained when the hydrophobic graft polymer is used alone. In addition, the coating film obtained from the coating composition of the present invention does not impair the original performance of the coating film, and the coating film surface has excellent water and oil repellency, stain resistance, and low friction (when silicone graft polymer is used). It provides a particularly remarkable low friction effect) and at the same time provides excellent adhesion to the base of the coating film. Next, Reference Examples, Examples, and Comparative Examples are listed to explain the present invention in more detail. In addition, all percentages listed in each example represent weight percent,
Parts represent parts by weight. Reference Example 1 Synthesis of terminal methacrylate type methyl methacrylate macromonomer After stirring, add 10 methyl methacrylate (hereinafter abbreviated as MMA) to a glass flask equipped with a reflux condenser, dropping funnel, thermometer and gas inlet.
and acetone (17.5%)-toluene mixed solvent 83
After introducing N ₂ , a polymerization initiator was added under reflux, and 0.5 parts of azobisisobutyronitrile (hereinafter abbreviated as AIBN) and 0.32 parts of thioglycolic acid as a chain transfer agent were added to initiate polymerization. . after that
During 4.5 hours, 90 parts of MMA was continuously dropped,
In addition, 2.88 parts of thioglycolic acid was dissolved in 7 parts of toluene, and added in 9 portions every 30 minutes.
Add 1.5 copies of AIBN every 1.5 hours, divided into 3 times,
Polymerization was carried out. Thereafter, the mixture was refluxed for 2 hours to complete the polymerization, and a polymer solution having the following structural formula [] was obtained. The reaction temperature was 77-87°C. A portion of the reaction solution was reprecipitated with n-hexane and dried, and the acid value was measured and found to be 0.340 mg equivalent/g. Next, after distilling off a part of the acetone from the above reaction solution, 0.5% of triethylamine was used as a catalyst, and hydroquinone monomethyl ether was used as a polymerization inhibitor.
Add 200 ppm, add 1.2 times the molar amount of glycidyl methacrylate to the acid value, and under reflux (approximately 110°C)
was allowed to react for 11 hours. The reaction rate determined from the decrease in acid value was 96%. The reaction solution was poured into 10 times the volume of n-hexane to precipitate it, and then dried under reduced pressure at 80°C.
90 parts of a macromonomer having the following structural formula [] was obtained.
Gel permeation chromatograph (below)
The polystyrene equivalent molecular weight by GPC was 2840 (number average) and 6470 (weight average). Moreover, the hydroxyl value was 0.350 mg-equivalent/g. Reference Example 2 Synthesis of fluorine-based graft polymer by macromonomer method Synthesis of fluoroalkyl acrylate (trunk)/methyl methacrylate (branch)-comb-shaped graft polymer The macromonomer obtained in Reference Example 1 was placed in the same apparatus as Reference Example 1. 70 parts, 30 parts of fluoroalkyl acrylate of the following structural formula [], 270 parts of trifluorotoluene (C ₆ H ₅ CF ₃ ), and 0.35 parts of AIBN,
The reaction was carried out under reflux (approximately 100° C.) for 5 hours while introducing N ₂ . [] CF ₃ − (CF ₂ −) _o CH ₂ −CH ₂ −OCO−CH=
A mixture of n=4 to 12 in _CH2 (average value of n about 7). This reaction solution was poured into 10 times the amount of methanol to precipitate it, and the mixture was dried under reduced pressure at 80 DEG C. to obtain 67 parts of a graft polymer. This one shows a single peak by GPC,
Polystyrene equivalent molecular weight is 10800 (number average) and
It was 21,700 (weight average). In addition, trifluorotoluene was added as an internal standard substance, and the 'H-NMR spectrum was measured in _CDCl3 solvent, and the H of trifluorotoluene and the H of -O- _CH3 in the MMA unit in the polymer The content of MMA units in the graft polymer was determined from the peak area ratio to be 60%. 40 left
% as fluoroalkyl acrylate. In this way, a fluorine-based graft polymer with a fluorine content of 40% was obtained. Also, by changing the amount of fluoroalkyl acrylate and performing the same operation, the fluorine content can be reduced.
61%, 21%, molecular weight is about 10,000 (number average)
A fluorine-based graft polymer was also synthesized. Reference Example 3 Synthesis of hydrophilic graft polymer Synthesis of acrylic acid + MMA (trunk)/MMA (branch) - comb-shaped graft polymer, 40 parts of the macromonomer obtained in Reference Example 1 and acrylic 15 parts acid, 45 parts MMA, ethanol (25vol
%)-tetrahydrofuran mixed solvent 270 parts,
Prepare 0.78 parts of AIBN, introduce _N2 , and under reflux (52 to 66
℃) for 6 hours. Pour this reaction solution into 10 times the volume of n-hexane,
Precipitate and dry under reduced pressure at 80℃ to obtain graft polymer.
Got 55 copies. This one shows a single peak by GPC,
The polystyrene equivalent molecular weight was 8,700 (number average) and 24,800 (weight average). Further, the acid value was 1.32 mg equivalent/g. Reference Example 4 Synthesis of silicone-based graft polymer (Part 1) α,ω-dihydroxydimethylpolysiloxane [

220g (0.1 mol) of silicone with [formula] where n is 30 on average] and 9.49g (0.12 mol) of pyridine
In a solution of γ in 400 ml of diethyl ether,
- A 10% diethyl ether solution of 12.06 g (0.05 mol) of methacryloxypropylmethyldichlorosilane was gradually added dropwise at room temperature over 20 minutes. The reaction proceeded immediately and white crystals of pyridine hydrochloride precipitated. After the addition was completed, the mixture was further stirred at room temperature for 1 hour, and the crystals of pyridine hydrochloride were removed by filtration. Next, put this filtrate into a separating funnel and add water.
Add 500 ml, shake well, and wash with water.
After washing with water, the separatory funnel was left standing to separate the upper ether layer and the lower aqueous layer, and anhydrous sodium sulfate was added to the obtained ether layer, which was then left overnight at room temperature to dehydrate. Thereafter, anhydrous sodium sulfate was removed by filtration, and the resulting filtrate was distilled under reduced pressure to remove ether, yielding 225 g of transparent and colorless acrylic modified silicon. Next, the obtained acrylic modified silicone and MMA
were copolymerized. For copolymerization, 50 parts of the acrylic modified silicone, 50 parts of MMA, 1.0 part of azobisisobutylronitrile, and 300 parts of toluene were placed in a flask equipped with a condenser and a stirrer, and the mixture was reacted at a temperature of 80° C. for 24 hours in a nitrogen atmosphere. After the reaction, toluene and unreacted MMA were removed by vacuum distillation to obtain a solid reactant. Next, unreacted acrylic modified silicone is extracted from the reaction product with n-hexane, and dried under reduced pressure to form a white powdery silicone graft polymer.
81 copies were obtained. This silicone-based graft polymer was soluble in toluene, xylene, and thinner. Further, as a result of analysis, the amount of silicone contained in this silicone-based graft polymer was 40% as dimethylpolysiloxane, and the number average molecular weight in terms of polystyrene was 90,000. For silicone analysis, accurately weigh approximately 0.2 g of silicone-based graft polymer in a platinum crucible, and approximately 3 ml of concentrated sulfuric acid.
was added, placed in an electric furnace and heated at 700℃ for 2 hours.
Silicone was obtained as _SiO2 . Moreover, the molecular weight is a value determined by liquid chromatography. Reference Example 5 Synthesis of silicone-based graft polymer (Part 2) α,ω-dihydroxydimethylpolysiloxane [

[Formula] n is 300 on average] 100 parts silicone, 83 parts styrene, 67 parts butyl acrylate,
and 0.75 parts of di-t-butyl peroxide were placed in a flask equipped with a condenser and a stirrer, and reacted in a nitrogen atmosphere at a temperature of 122°C for 7 hours. A small amount of unreacted monomer was removed at 80°C and under reduced pressure of 1 mmHg. The reaction product was a white highly viscous oil. Even when an attempt was made to dissolve the reaction product in toluene, xylene, or thinner, there were some undissolved substances, resulting in a cloudy solution. Further, as a result of analysis, the amount of silicone contained in this silicone-based graft polymer was 45% as dimethylpolysiloxane. The silicone-based graft polymer contained a small amount of styrene homopolymer, butyl acrylate homopolymer, and styrene/butyl acrylate copolymer in addition to the graft polymer grafted onto silicone. 10% trifluorotoluene solution of the fluorine-based graft polymer with a fluorine content of 61% shown in Example 1, Comparative Examples 1, 2, 3, and Reference Example 2 (hereinafter abbreviated as fluorine-based graft polymer solution) and a 10% acetone/toluene mixed solvent solution (hereinafter abbreviated as hydrophilic graft polymer solution) of the carboxyl group-containing hydrophilic graft polymer shown in Reference Example 3 were prepared. The obtained fluorine-based graft polymer solution and hydrophilic graft polymer solution were added to an air-drying acrylic clear paint (a 20% thinner solution of MMA and ethyl acrylate copolymer). The coating composition of the present invention was prepared by adding each polymer to 1% of the nonvolatile content of the acrylic clear paint. Next, this coating composition of the present invention was coated onto a glass plate using a bar coater. After air drying in a fume hood for one day, a transparent coating film with a thickness of 50 μm was obtained. The coating surface was smooth and free of pinholes. Table 1 shows the results of the water contact angle of the coating film surface, stain resistance, and adhesion between the coating film and the glass plate for Example 1.
It was shown as Further, the acrylic clear paint containing only the fluorine-based graft polymer (the content of the fluorine-based graft polymer is the same as in Example 1)
The physical properties of the coating film obtained are also shown in Table 1 as Comparative Example 1. In addition, the physical properties of a coating film obtained from the acrylic clear paint containing only the hydrophilic graft polymer (the content of the hydrophilic graft polymer is the same as in Example 1) are shown in Table 1 as Comparative Example 2. In addition, the physical properties of the coating film obtained only from the acrylic clear paint are also shown in Table 1 as Comparative Example 3.

[Table] As shown in Table 1, the coating film obtained from the coating composition of the present invention has a significantly modified surface, water repellency,
It can be seen that the stain resistance is extremely excellent and the adhesion is also significantly improved. In addition, contact was better when a fluorine-based graft polymer and a hydrophilic graft polymer were added simultaneously (Example 1) as in the coating composition of the present invention than when only a fluorine-based graft polymer was added (Comparative Example 1). The corners are significantly larger, indicating a greater surface modification effect. Examples 2, 3 and Comparative Examples 4, 5, 6 A 10% trifluorotoluene solution of the fluorine-based graft polymer with a fluorine content of 40% obtained in Reference Example 2 and the same hydrophilic solution used in Example 1. Apply the graft polymer solution to an air-drying acrylic clear paint (ethyl acrylate, butyl acrylate,
The fluorine graft polymer and the hydrophilic graft polymer were added to a 25% thinner solution of MMA copolymer in the ratio shown in Table 2 based on the non-volatile content of the acrylic clear paint. Two inventive coating compositions were formulated. Next, these coating compositions of the present invention were coated onto glass plates using a bar coater. After being air-dried for one day in a fume hood, a transparent coating film with a thickness of 50 μm was obtained in each case. All coating film surfaces were smooth and free of pinholes. Table 2 shows the results of the contact angle of the paint film surface with water, the stain resistance of the paint film surface, and the adhesion between the paint film and the glass plate.
This is shown as Examples 2 and 3. In addition, the physical properties of coating films obtained from the acrylic clear paint containing only the fluorine-based graft polymer are also shown in Table 2 as Comparative Examples 4 and 5.
In addition, the physical properties of a coating film obtained only from the acrylic clear paint are also shown in Table 2 as Comparative Example 6. The contact angle, stain resistance, and adhesion shown in Table 2 were measured in the same manner as in Example 1.

[Table] Example 4 and Comparative Example 7 A 10% toluene solution of the silicone-based graft polymer obtained in Reference Example 4 and the same hydrophilic graft polymer solution used in Example 1 were used. The silicone-based graft polymer and the hydrophilic graft polymer are added to the same air-drying acrylic clear paint in an amount of 0.5% each based on the non-volatile content of the acrylic clear paint,
A coating composition of the present invention was formulated. Next, this coating composition of the present invention was coated onto a glass plate using a bar coater. After air drying in a fume hood for one day, a transparent coating film with a thickness of 50 μm was obtained. The coating surface was smooth and free of pinholes. The results of the contact angle of the coating film surface with water, the stain resistance of the coating film surface, the adhesion between the coating film and the glass plate, and the static friction angle of the coating film surface are shown in Table 3 as Example 4. In addition, the physical properties of a coating film obtained only from the acrylic clear paint are also shown in Table 3 as Comparative Example 7. The contact angle, stain resistance, and adhesion measurements in Table 3 were the same as in Example 1, and the static friction angle was measured using a friction angle measuring machine manufactured by Toyo Seiki Seisakusho. . The measurement method is to attach a sample formed on a glass plate to this friction angle measuring device, and place a 100g cube (vertical x horizontal x
Height = 25 x 25 x 20 mm) was placed on the sample, and the sample was tilted at a tilting speed of 2.7°/sec to set the angle at which the cube begins to slide on the coating surface.

[Table] As shown in Table 3, the surface of the coating film obtained from the coating composition of the present invention was significantly modified, and it was found that it was endowed with excellent water repellency, stain resistance, and low friction properties. It can also be seen that the adhesion was significantly improved. Example 5 and Comparative Example 8 The silicone graft polymer obtained in Reference Example 5, the same hydrophilic graft polymer as used in Example 1, and the same air-drying acrylic clear paint as used in Example 1 were used. A coating composition of the present invention was prepared in the same manner as in Example 4. Next, this coating composition of the present invention was coated onto a glass plate using a bar coater. After air drying in a fume hood for one day, a transparent coating film with a thickness of 50 μm was obtained. The coating surface was smooth and free of pinholes. The results of the contact angle of the coating film surface with water, stain resistance, and adhesion between the coating film and glass are shown in Table 4 as Example 5. In addition, the physical properties of the coating film obtained from the acrylic clear paint containing only the silicone graft polymer (the content of the silicone graft polymer is the same as in Example 5) are also shown in Table 4 as Comparative Example 8. .

[Table] Example 6 and Comparative Examples 9 and 10 A 10% trifluorotoluene solution of the fluorine-based graft polymer with a fluorine content of 40% obtained in Reference Example 2 and the same hydrophilicity as used in Example 1. The graft polymer solution is applied to a baking-type thermosetting acrylic clear paint (a 20% thinner solution consisting of a copolymer of MMA/hydroxyethyl acrylate/styrene/acrylic acid/butyl acrylate and melamine resin), and the nonvolatile acrylic clear paint is The coating composition of the present invention was prepared by adding the fluorine-based graft polymer in an amount of 0.2% and the hydrophilic graft polymer in an amount of 1% per minute. Next, this coating composition of the present invention was coated onto a glass plate using a bar coater. After drying in a draft for one day and baking at 200℃ for 30 minutes, the thickness will increase.
A transparent coating film of 30μ was obtained. The coating surface was smooth and free of pinholes. Table 5 shows the results of the contact angle of the paint film surface with water, the stain resistance of the paint film surface, and the adhesion between the paint film and the glass plate.
This is shown as Example 6. In addition, the physical properties of the coating film obtained from the acrylic clear paint containing only the fluorine-based graft polymer (the content of the fluorine-based graft polymer is the same as in Example 6) are also shown in Table 5 as Comparative Example 9. Indicated.
In addition, the physical properties of the coating film obtained only from the acrylic clear paint are also shown in Table 5 as Comparative Example 10. The methods for measuring the contact angle, stain resistance, and adhesion shown in Table 5 are the same as in Example 1.

[Table] Example 7 and Comparative Examples 11 and 12 A 10% trifluorotoluene solution of the fluorine-based graft polymer with a fluorine content of 21% obtained in Reference Example 2 and the same hydrophilicity as used in Example 1. The graft polymer solution is used as a two-component reaction-curing acrylic urethane paint (trade name: Aroncoat FC Deluxe (white), the main ingredient is 60% thinner solution, and the hardening agent is 50%.
A toluene solution (method of use is to mix so that the weight ratio of base resin/curing agent is 7/1) is mixed with the base resin, the fluorine-based graft polymer is 1% based on the nonvolatile content of the acrylic urethane paint, and the hydrophilic A coating composition of the present invention was prepared by adding the graft polymer to a concentration of 1%. That is, the coating composition of the present invention is composed of a base material containing a fluorine-based graft polymer and a hydrophilic graft polymer (hereinafter referred to as the base component of the coating composition of the present invention), and a curing agent. Next, 7 parts of the main ingredient of the coating composition of the present invention and 1 part of the curing agent were mixed and immediately coated on a glass plate using a bar coater. After being left in a fume hood for 4 days, a white coating film with a thickness of 50 μm was obtained. The coating surface was smooth and free of pinholes. Table 6 shows the results of the water contact angle of the coating film surface, stain resistance, and adhesion between the coating film and the glass plate for Example 7.
It was shown as In addition, the physical properties of the coating film obtained from the acrylic urethane paint containing only the fluorine-based graft polymer (the content of the fluorine-based graft polymer is the same as in Example 7) are also shown in Table 6 as Comparative Example 11. . In addition, the physical properties of a coating film obtained only from the acrylic urethane paint are also shown in Table 6 as Comparative Example 12. The methods for measuring the contact angle, stain resistance, and adhesion shown in Table 6 are the same as in Example 1.

[Table] Comparative Example 13 According to the method of Reference Example 2, the fluorine content was 7%,
A fluorine-based graft polymer with a number average molecular weight of approximately 20,000 was synthesized. of the fluorine-based graft polymer
A 10% trifluorotoluene solution was prepared, and a coating composition was prepared in the same manner as in Example 1, and coated on a glass plate using a bar coater. After air drying in a fume hood for one day, a transparent coating film with a thickness of 50 μm was obtained. Although the adhesion between the paint film and the glass plate was 100% in the cross-cut test, the contact angle of the paint film surface to water was 80°, and no significant water repellent effect was obtained. Comparative Example 14 A fluorine-based graft polymer with a fluorine content of 85% and a number average molecular weight of approximately 25,000 was synthesized according to the method of Reference Example 2, but the fluorine-based graft polymer did not dissolve in trifluorotoluene or thinner. , it could not be added to paints.

Claims (1)

[Scope of Claims] 1. An improved coating composition prepared by dissolving the following hydrophobic graft polymer and hydrophilic graft polymer in an organic solvent solution of a film-forming resin that is highly compatible with some of their constituent components. . Hydrophobic graft polymer: A graft polymer consisting of a polymer unit whose main component is a fluorine-containing monomer unit and a polymer unit whose main component is a methyl methacrylate monomer unit, a silicone unit, and a methyl methacrylate monomer unit. A graft polymer consisting of a polymer unit whose main component is a mer unit, or a graft polymer consisting of a silicone unit and a polymer unit whose main components are an acrylic acid ester monomer unit and a styrene monomer unit. Hydrophilic graft polymer: A graft polymer consisting of a polymer unit consisting of a carboxyl group-containing monomer unit and another vinyl monomer unit, and a polymer unit containing a methyl methacrylate monomer unit as a main component.