JPH0424393B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a coating composition obtained by dissolving a silicone-based graft copolymer in an organic solvent solution of a film-forming resin. The object of the present invention is to provide a coating composition capable of forming a coating film provided with. 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.In order to impart water- and oil-repellency, stain resistance, and low-friction properties to the coating surface, various types of paints are being developed. method is being considered. For example, surface grafting of monomers by irradiating the coating surface with radiation, light, or plasma, coating the coating surface with coupling agents such as oligomers, polymers, or silanes, and polymers with low surface energy such as silicone resins and fluorine resins. Methods such as adding it to paints are being carried out. Among these methods, surface grafting of monomers by irradiating the coating surface with radiation, light, or plasma requires special equipment, and coatings with improved surfaces are expensive, and they require the use of oligomers, polymers, silanes, etc. In the method of coating the coating surface with a coupling agent,
The modification of the coating film surface is temporary and the modification effect on the coating film surface is not durable, and there are problems such as the coated substance is easy to remove or it is difficult to create a thin coating film. many. Alternatively, adding polymers with low surface energy such as silicone resins and fluorine resins to paints is not satisfactory, as the durability of the modification effect on the surface of the paint film is never satisfactory.
In order to maintain a sufficient modification effect on the surface of the coating film, a large amount of addition is required, which may impair the original performance of the coating film. In particular, the adhesion between the paint film and the underlying surface deteriorates. The present invention has been achieved as a result of intensive research in view of these conventional drawbacks. That is, the present invention provides a method for producing a coating composition in which a silicone-based graft copolymer is dissolved in an organic solvent solution of a film-forming resin, in which the silicone-based graft copolymer is represented by general formula (A). A high molecular weight silicone monomer obtained by reacting a silicone living polymer obtained by anionically polymerizing a cyclic siloxane with a compound represented by general formula (B) is copolymerized with other radically polymerizable monomers. This is a method for producing a coating composition characterized by using a silicone-based graft copolymer. (A) (In the formula, R ₁ is a methyl group, ethyl group, or phenyl group, and P is 3 or 4.) (B) or (In the formula, R ₂ is hydrogen or a methyl group, m is 0 or 1, R ₃ and R ₄ are methyl, ethyl, or phenyl groups, n is an integer from 1 to 3, and is 0 when m = 0. An integer of ~2, 2 when m=1.) The present inventors first set silicone as a branch component,
According to a coating composition obtained by adding a silicone-based graft copolymer having a polymer having good compatibility with the film-forming resin as a main component to an organic solvent solution of the film-forming resin, the coating film formed can be reduced. They discovered that the surface of the coating composition has properties such as water and oil repellency, stain resistance, and low friction, and also has good adhesion between the coating film and the underlying surface, and filed a patent application for this coating composition. [Special Patent Application No. 129075 (1982)]
30715) and Japanese Patent Application No. 57-35857 (Patent Publication No. 1-60162)]. Said Patent Application No. 129075 and Patent Application No. 1987-
The coating composition according to No. 35857 with the above structure contains α,ω-dihydroxy silicone, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropylethyldichlorosilane, and γ-acryloxy as silicone-based graph copolymers. It was a coating composition containing a silicone-based graft copolymer obtained by copolymerizing acrylic-modified silicone obtained by reacting propylmethyldichlorosilane etc. with other radically polymerizable monomers. , a high molecular weight silicone in which a living polymer obtained by anionically polymerizing a cyclic siloxane represented by the general formula (A) is polymerized and terminated with a living polymer sealing compound having a (meth)acryloyl group or styryl group in the molecule. A similar coating composition containing a silicone-based graft polymer composed of a monomer and another radically polymerizable monomer also exhibited effects equivalent to or superior to those of the coating composition of the existing application. I discovered that. The details of the high molecular weight silicone monomer (hereinafter referred to as silicone macromonomer) used in the present invention are as described below. compared to
It has the advantage that the content of bifunctional silicone, that is, silicone having polymerizable groups at both ends of the molecule and/or silicone to which no polymerizable group is bonded, is small. In the coating film made of the coating composition obtained by the production method of the present invention, the silicone copolymer, which is one component of the composition, migrates or concentrates on the surface of the coating film, and as a result, the characteristics of the silicone Characteristics such as water and oil repellency, stain resistance, and low friction properties are expressed on the coating surface. On the other hand, in the layer on the base material side of the coating film, there is almost no silicone copolymer, and only the coating-forming resin is present, so it has excellent adhesion to the substrate. . Furthermore, since the silicone-based graft polymer employs a polymer having good compatibility with the coating-forming resin as its backbone component, the above-mentioned surface properties are maintained for a long period of time. Examples of coating substrates to which the coating composition obtained according to the present invention can be applied include those commonly used such as metals, ceramics, wood, and plastics. In the present invention, the cyclic siloxane represented by the general formula (A) includes hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, hexaethylcyclotrisiloxane, octaethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, octaphenyl Examples include cyclotetrasiloxane, of which hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane are particularly preferred in terms of cost and ease of anionic polymerization. The anionic polymerization of the cyclic siloxane can be easily carried out using a known anionic polymerization initiator. Examples of anionic polymerization initiators that can be used in the present invention include organolithium compounds represented by the general formula RLi (R is a monovalent hydrogen group having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, n-hexyl, octadecyl, phenyl, cyclohexyl, 4-butylphenyl, etc.), alkali metal hydroxides (e.g.
CsOH, RbOH, KOH, NaOH, LiOH, etc.), alkali metal alkoxides (e.g. sodium methylate, sodium ethylate, potassium methylate, potassium ethylate, etc.) and alkali metal silanolates (e.g. trimethylsilanolate of Li, Na, K, (triethylsilanolate, tripropylcitanolate, tributylsilanolate, etc.). Among these polymerization initiators, organic lithium compounds are particularly preferred. In anionic polymerization, the molecular weight of the living polymer, that is, the molecular weight of the silicone macromonomer, is controlled by the molar ratio of cyclic siloxane and initiator, and the molar ratio of initiator/cyclic siloxane is from 0.01 to
0.2 is preferred. When the molar ratio is less than 0.01, the living polymer tends to have an extremely high molecular weight (20,000 or more), and when the molar ratio is more than 0.2, the living polymer tends to have an extremely low molecular weight (1000 or less). Regarding the influence of the molecular weight of the silicone macromonomer (molecular weight of the living polymer) in the present invention, if the molecular weight of the silicone macromonomer is too small, the effects of silicone, that is, water repellency, oil repellency, and low friction properties will decrease; The silicone-based graft copolymer obtained by copolymerizing a silicone macromonomer and a radically polymerizable monomer tends to become oily and difficult to purify, so the molecular weight of the silicone macromonomer is preferably 1,000 to 20,000. The polymerization reaction of the cyclic siloxane represented by the general formula (A) using an anionic polymerization initiator can generally be carried out by a bulk polymerization method or a solution polymerization method.
In the case of bulk polymerization, the polymerization reactivity varies depending on the type of cyclic siloxane, but the polymerization can be achieved at 100℃ with the addition of only an initiator.
Even when higher temperatures are required, the reaction is extremely accelerated by the addition of a small amount of a polar compound such as dimethyl sulfoxide, tetrahydrofuran, phosphine oxide, etc., and a sufficient polymerization product can be obtained even at low temperatures. In the case of solution polymerization, if a polar solvent such as tetrahydrofuran is used as the solvent, the reaction is extremely accelerated and a high polymer can be produced at room temperature. The silicone macromonomer used in the present invention can be obtained by reacting the living polymer obtained as described above with a radically polymerizable silicone compound represented by general formula (B) (living polymerization termination reaction). . The radically polymerizable silicone compound represented by the general formula (B) can be easily obtained by a known method, for example (R ₂ , l, m, R ₃ , n are the same as above) is (R ₂ , l, m are the same as above) and unsaturated acrylate or methacrylate (hereinafter collectively referred to as (meth)acrylate) and HSi(R ₃ ) _3-o Cl _o (R ₃ , n are the same as above). It can be obtained by the hydrosilylation reaction of Examples of unsaturated (meth)acrylates that can be preferably used in the present invention include allyl (meth)acrylate, 3-butenyl (meth)acrylate, and 4-pentenyl (meth)acrylate.
Acrylate and 2-allyloxyethyl (meth)acrylate can be mentioned. Or

[Formula] (R ₄ , n are the same as above) is

p-vinylphenylmagnesium chloride obtained by Grignard reaction of [formula] and Mg

It can be obtained by the reaction of [Formula] with chlorosilane Si (R ₄ ) _3-o Cl _o+1 .
The amount of the radically polymerizable silicone compound represented by the general formula (B) is 1 equivalent of living polymerization initiator (1
The amount of Si-Cl of the general formula (B) is preferably 1 to 5 times equivalent to (mol). The reaction between the living polymer obtained by anionically polymerizing the cyclic siloxane represented by the general formula (A) and the silicone compound represented by the general formula (B) proceeds extremely smoothly. For example, a solution prepared by diluting a radically polymerizable silicone compound represented by general formula (B) with an appropriate solvent is added dropwise at room temperature to a living polymer solution after solution polymerization of a cyclic siloxane represented by general formula (A). In other words, the reaction is completed instantly. The desired silicone macromonomer can be obtained by filtering off the hydrochloride produced in the reaction, then washing with water if necessary, and evaporating the solvent. Since this silicone macromonomer contains trace amounts of low-molecular side reactants and residual monomers, it is desirable to purify it by reprecipitation in a solvent that does not dissolve silicone, such as methanol. The silicone macromonomer thus obtained has one acrylic, methacrylic, or styrene radical polymerization-reactive functional group at one end of its molecular chain, and is a linear silicone oligomer with well-regulated molecular weight and molecular weight distribution. , has extremely high polymerizability, copolymerization proceeds extremely smoothly with general radically polymerizable monomers, and silicone-based graft copolymers can be easily obtained. Its molecular weight can be controlled by known polymerization techniques. Radically polymerizable monomers that can be used in the present invention include methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, stearyl methacrylate, acrylic acid,
Methyl acrylate, ethyl acrylate, butyl acrylate, styrene, styrene substitutes, vinyl esters of organic acids such as vinyl acetate, low molecular weight linear hydrocarbons such as ethylene and propylene, vinyl chloride, vinylidene chloride, polyoxyethylene mono Examples include methacrylate. The monomers are preferably selected so that the backbone polymer of the silicone-based graft copolymer produced from these monomers is the same or compatible with the film-forming resin used in combination. For example, if methyl methacrylate is selected as the monomer, a silicone-based graft copolymer having polymethyl methacrylate as the backbone polymer can be obtained. This graft copolymer is not only effective in modifying the surface of coatings obtained with polymethyl methacrylate-based organic solvent-based paints, but also polyvinyl chloride-based, polyethylene terephthalate-based, and epoxy resins that are compatible with polymethyl methacrylate. It is also effective in modifying the surface of coatings obtained with resin-based organic solvent-based paints. The monomers can be used alone or in combination of two or more types. The copolymerization ratio of the silicone macromonomer and the radically polymerizable monomer should be determined so that the silicone content in the resulting silicone-based graft copolymer is 5 to 80% by weight, preferably 10 to 70% by weight. is preferred. Silicone content is 5% by weight
Coating compositions consisting of silicone-based graft copolymers and organic solvent-based paints with less than Moreover, if it exceeds 80% by weight, the surface modification effect of the coating film will not be improved, and the amount of expensive silicone macromonomer used will increase, resulting in an economic disadvantage. Conventionally known methods can be used for the radical copolymerization of the silicone macromonomer and the radically polymerizable monomer, and radiation irradiation methods, methods using radical polymerization initiators, etc. can be used, but methods using radical polymerization initiators can be used. is preferable from the viewpoint of ease of polymerization operation and ease of controlling the molecular weight of the silicone-based graft copolymer produced. Specifically, any method such as solution polymerization method using a solvent, bulk polymerization method, emulsion polymerization method, etc. is adopted. can do. As the radical polymerization initiator that can be used in the production of the graft copolymer, commonly used radical polymerization initiators can be used, and an appropriate one can be selected depending on the polymerization method. Examples of inorganic radical polymerization initiators include ammonium persulfate; organic radical polymerization initiators include peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, peroxyester, azo Any azo compound such as bisisobutyronitrile can be used, but in order to obtain a silicone-based graft copolymer with a relatively clear structure, organic peroxides and azo compounds with low decomposition temperatures are recommended. are preferred, and azo compounds are particularly preferred. As an azo compound, both N atoms of the azo bond are bonded to a tertiary carbon atom, and the remaining valence of the tertiary carbon atom is preferably a nitrile, carboxyalkyl, cycloalkylene or Azo compounds filled with alkyl groups, azobisisobutyronitri (abbreviated as transitional AIBN), are most preferred. When copolymerizing by ultraviolet irradiation, a known sensitizer is used as a radical polymerization initiator, and when copolymerizing by electron beam irradiation, there is no need to use a radical polymerization initiator. The amount of radical polymerization initiator is generally 0.01 to 5% based on the total weight of raw material components.
Weight % is preferred. More preferably 0.1 to 2% by weight. The silicone-based graft copolymer obtained in this way is a graft copolymer having a polymer obtained from a radically polymerizable monomer as a trunk and a silicone macromonomer as branches, and the number of branch points is determined by the number of branches used. It can be determined from the molecular weight of the silicone macromonomer, the molecular weight of the radically polymerizable monomer, the molecular weight of the silicone-based graft copolymer, and the silicone content in the silicone-based graft copolymer. In the present invention, the paint to which the silicone-based graft copolymer is added is an organic solvent type paint in which a film-forming resin is dissolved in an organic solvent, and specifically, nitrocellulose lacquer, acrylic lacquer, etc. Paints that form a continuous coating simply by volatilization of organic solvents, such as car and vinyl resin paints, oil-based paints, alkyd resin paints, amino alkyd resin paints, unsaturated polyester paints, epoxy resin paints, and polyurethane paints. These are paints in which a cross-linked paint polymer is dissolved in an organic solvent, and a continuous paint film is formed by a cross-linking reaction that progresses after painting due to oxygen in the air, catalysts, heating, etc. The amount of the silicone-based graft copolymer used in the present invention added to the organic solvent-based paint is preferably 0.01 to 0.01 to the non-volatile content (solid content) of the organic solvent-based paint.
The content is 10% by weight, more preferably 0.05 to 3% by weight. The addition method is to directly add the silicone-based graft copolymer used in the present invention to an organic solvent-based paint, or to dissolve the silicone-based graft copolymer in an appropriate solvent and add the resulting solution to an organic solvent-based paint. Any method of adding may be used. As described above, according to the present invention, the unique property of the present invention is that it has excellent adhesion to the base material, and the surface properties of the resulting coating film are water- and oil-repellent, stain-resistant, and low-friction. A coating composition with performance can be easily obtained. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. In addition, all % described in each example represents weight %,
Parts represent parts by weight. Furthermore, the performance of the coating films obtained in each example was evaluated using the following evaluation method. (1) Contact angle: Contact angle of water on the surface of the paint film in contact with air (measured at 25°C with a goniometer type contact angle measuring device) (2) Stain resistance: 0.2ml of 5% water slurry of activated carbon Activated carbon comes loose when it is dropped on the surface of the paint film that is in contact with the air, air-dried, and then washed with water using a brush. ◎: No activated carbon remains at all. ○: A little bit of 〃 is attached and it is a little black. ×: 〃 is attached and turned black. (3) Adhesion (survival rate of cross-cut test): A 2 mm square cross-section cut was made with a knife, and the cross-section was removed with cellophane tape for evaluation. The residual rate was expressed in %. (4) Detergent cleaning test: The coating film is immersed in a 1% detergent (Mama Lemon) aqueous solution at 40°C and stirred for 4 hours. After that, it was thoroughly washed with water and air-dried overnight, and then the contact angle of the surface of the coating film with water was measured. Durability to detergents was evaluated by comparison with the contact angle of the coating film surface before the detergent cleaning test. Example 1 and Comparative Examples 1 and 2 0.5 g (0.0128 mol) of potassium metal and about 5 ml of n-hexane were placed in a flask, and 10 ml of methanol was added dropwise over 30 minutes in an ice bath under a stream of dry nitrogen. After stirring for an additional 30 minutes, excess methanol and n-hexane were distilled off under reduced pressure. Next, 40 g (0.135 mol) of octamethylcyclotetrasiloxane and tetrahydrofuran, which had been sufficiently dehydrated with a molybdenum sieve, were added.
Potassium salt/octamethylcyclotetrasiloxane = 0.40g was added and heated under reflux for 4 hours.
095 (molar ratio). After the temperature of the reaction solution decreased to room temperature, 10% of γ-methacryloxypropyldimethylchlorosilane was added.
31g of tetrahydrofuran solution (0.0141mol of γ-methacryloxypropyldimethylchlorosilane)
was gradually added dropwise, and after the addition was completed, the mixture was further stirred at room temperature for 30 minutes. The Si-Cl/potassium salt of γ-methacryloxypropyldimethylchlorosilane was 1.10 (equivalent ratio). After filtering out the generated potassium chloride precipitate, the filtrate was poured into methanol (1) to precipitate the silicone macromonomer. After decanting and drying, 26.0 g of a colorless and transparent oily silicone macromonomer was obtained. The silicone macromonomer had a polystyrene equivalent number average molecular weight of 8900 by gel permeation chromatography (hereinafter abbreviated as GPC). Next, the obtained silicone macromonomer and methyl methacrylate (hereinafter referred to as MMA) were copolymerized. Copolymerization is performed using the silicone macromonomer 50
1 part, 50 parts of MMA, 1.0 part of AIBN, and 300 parts of toluene were placed in a flask equipped with a condenser and a stirrer, and reacted in a nitrogen atmosphere at a temperature of 80°C for 24 hours. After the reaction, triene and unreacted MMA were removed by vacuum distillation to obtain a white solid reaction product. Next, unreacted silicone macromonomer is extracted from the reaction product with n-hexane, and dried under reduced pressure to obtain a white powdery silicone-based graft copolymer.
part was obtained. This silicone-based graft copolymer was soluble in toluene, xylene, and thinner. Further, as a result of analysis, the amount of silicone (as dimethylpolysiloxane) contained in this silicone-based graft copolymer was 35%, and the number average molecular weight in terms of polystyrene by GPC was 32,000. For analysis of silicone, approximately 0.2 g of silicone-based graft copolymer was accurately weighed in a platinum crucible, approximately 3 ml of concentrated sulfuric acid was added, and the mixture was heated in an electric furnace at 700°C for 2 hours to determine silicone as SiO ₂ . A 10% thinner solution of the thus obtained silicone-based graft copolymer is made, and the solution is applied to an acrylic clear paint (a 20% thinner solution of MMA and ethyl acrylate copolymer) so that the silicone-based graft copolymer becomes a paint. 0.5% for polymers
An acrylic clear paint containing a silicone graft copolymer was prepared. Next, the acrylic clear paint was applied onto a glass plate using a bar coater. When air-dried for a day in a draft, the thickness becomes 50. A transparent coating film of μ was obtained. The surface of the coating film was smooth and free of pinholes. 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 base of the glass plate, and the detergent cleaning test of the coating film were evaluated according to the above evaluation method. The results are shown in Table 1 as Example 1. In addition, commercially available silicone additives (KF-96, Shin-Etsu Silicone Products) are added to the acrylic clear paint.
The same amount as in Example 1 was added, and the results of the surface physical properties of the resulting paint film are shown as Comparative Example 1, and the results of the surface physical properties of the paint film obtained only from the acrylic clear paint are shown as Comparative Example 2. -1.

[Table] As shown in Table 1, the coating composition to which the silicone-based graft copolymer of the present invention was added was found to have a significantly modified coating film surface, imparting water repellency and stain resistance. Modification results do not deteriorate,
It was found that it had excellent durability and surprisingly improved adhesion. Example 2 and Comparative Example 3 A 10% thinner solution of the silicone graft copolymer obtained in Example 1 was mixed into a thermosetting acrylic clear paint (MMA/hydroxyethyl acrylate/styrene/acrylic acid/butyl acrylate copolymer). The silicone-based graft copolymer was added to a 20% thinner solution (composed of polymer and melamine resin) in an amount of 0.5% based on the paint polymer to form a thermosetting acrylic clear paint containing the silicone-based graft copolymer. I mixed it. Next, this thermosetting acrylic clear paint containing a silicone graft copolymer was applied onto a glass plate using a bar coater. After drying in a draft for one day and baking at 200°C for 30 minutes, a transparent coating film with a thickness of 30 μm was obtained.
The surface of the coating film was smooth and free of pinholes. The contact angle of the coating film surface with water, stain resistance, adhesion between the coating film and the substrate of the glass plate, and the detergent cleaning test of the coating film were evaluated according to the above-mentioned evaluation method. The results are shown in Table 2 as Example 2. The surface properties of a coating film obtained only from the thermosetting acrylic clear paint are also shown in Table 2 as Comparative Example 3.

[Table] Example 3 A solution of 47.3 g (213 mmol) of hexamethylcyclotrisiloxane dissolved in 200 ml of dry tetrahydrofuran was added to a solution of 1.26 g (13.1 mmol) of lithium trimethylsilanolate dissolved in 200 ml of dry tetrahydrofuran, and a solution of 47.3 g (213 mmol) of hexamethylcyclotrisiloxane dissolved in 200 ml of dry tetrahydrofuran was added. Polymerization was carried out at 0°C under atmosphere for 24 hours. Lithium trimethylsilanolate/hexamethylcyclotrisiloxane=0.062 (molar ratio). Next, 86.5 g of a 10% tetrahydrofuran solution of γ-methacryloxypropyldimethylchlorosilane (8.65 g (39.2 mmol) of γ-methacryloxypropyldimethylchlorosilane) was gradually added dropwise to this reaction solution.
The mixture was stirred at 0°C for an hour. The SiCl/lithium trimethylsilanolate ratio of γ-methacryloxypropyldimethylchlorosilane was 2.99 (equivalent ratio). After filtering off the generated lithium chloride precipitate, methanol was added to precipitate the silicone macromonomer. After decanting and drying, 48.3 g of a colorless and transparent oily silicone macromonomer was obtained. The silicone macromonomer had a polystyrene equivalent number average molecular weight of 4,400 by GPC. Next, the obtained silicone macromonomer and
MMA was copolymerized. For copolymerization, 50 parts of the silicone macromonomer, 50 parts of MMA, 1.0 part of AIBN, 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. Thereafter, the same operation as in Example 1 was carried out to obtain 90 parts of a white powdery silicone-based graft copolymer. This silicone-based graft copolymer was soluble in toluene, xylene, and thinner. Also, as a result of analysis, the amount of silicone contained in this silicone-based graft copolymer was 43%,
The polystyrene equivalent number average molecular weight by GPC is
It was 47,000. A 10% thinner solution of the silicone graft copolymer thus obtained was prepared, and an acrylic clear paint containing the silicone graft copolymer was prepared in the same manner as in Example 1. Next, the acrylic clear paint was applied onto a glass plate using a bar coater. After air drying in a fume hood for one day, a transparent coating with a thickness of 55 μm was obtained. The surface of the coating film was smooth and free of pinholes. The contact angle of the surface of the coating film in contact with water with water was 101°. The contact angle of the surface in contact with air with water of the coating film obtained from the acrylic clear paint not containing the silicone graft copolymer was 74°. Example 4 3 as a compound for end-capping living polymers
The same procedure as in Example 3 was carried out, except that 10.4 g (39.2 mmol) of -(2-methacryloyloxyethoxy)propyldimethylchlorosilane was used, to obtain 48.8 g of a silicone macromonomer. Si-Cl/lithium trimethylsilanolate of 3-(2-methacryloyloxyethoxy)propyldimethylchlorosilane was 2.99 (equivalent ratio). The silicone macromonomer had a polystyrene equivalent number average molecular weight of 4,300 by GPC. Next, 50 parts of the obtained silicone macromonomer and
Copolymerization of 50 parts of MMA was carried out in the same manner as in Example 3,
88 parts of a silicone-based graft copolymer was obtained. This silicone-based graft copolymer was soluble in toluene, xylene, and thinner. As a result of analysis, the amount of silicone contained in this silicone-based graft copolymer was 40%.
The polystyrene equivalent number average molecular weight by GPC is
It was 51000. A 10% thinner solution of the thus obtained silicone-based graft copolymer was prepared, and an acrylic clear paint containing the silicone-based graft copolymer was prepared in the same manner as in Example 1. Next, the acrylic clear paint was applied 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 55 μm was obtained. The surface of the coating film was smooth and free of pinholes. The contact angle of the surface of the coating film in contact with water with water was 103°. The contact angle of the surface in contact with air with water of the coating film obtained from the acrylic clear paint not containing the silicone graft copolymer was 74°. Example 5 As a compound for end-capping living polymers,
P-vinylphenyldimethylchlorosilane 7.68g
The same operation as in Example 3 was carried out except for using (39.2 mmol) of silicone macromonomer.
Obtained 47.9g. P-vinylphenyldimethylchlorosilane Si-Cl/
Lithium trimethylsilanolate = 2.99 (equivalent ratio). The silicone macromonomer had a polystyrene equivalent number average molecular weight of 4100 by GPC. Next, 50 parts of the obtained silicone macromonomer and
Copolymerization of 50 parts of MMA was carried out in the same manner as in Example 3,
83 parts of a silicone-based graft copolymer was obtained. This silicone-based graft copolymer was soluble in toluene, xylene, and thinner. As a result of analysis, the amount of silicone contained in this silicone-based graft copolymer was 41%.
The polystyrene equivalent number average molecular weight by GPC is
It was 43,000. A 10% thinner solution of the silicone graft copolymer thus obtained was prepared, and an acrylic clear paint containing the silicone graft copolymer was prepared in the same manner as in Example 1. Next, the acrylic clear paint was applied 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 55 μm was obtained. The surface of the coating film was smooth and free of pinholes. The contact angle of the surface of the coating film in contact with water with water was 100°. The contact angle of the surface in contact with air with water of the coating film obtained from the acrylic clear paint not containing the silicone graft copolymer was 74°. Example 6 As an end-capping compound in a living polymer,
Example 1 except that 1.71 g (7.1 mmol) of γ-methacryloxypropylmethyldichlorosilane was used.
Perform the same operation as silicone macromonomer.
Obtained 27.3g. The Si-Cl/potassium metal ratio of γ-methacryloxypropylmethyldichlorosilane was 1.11 (equivalent ratio). The silicone macromonomer is GPC
The number average molecular weight in terms of polystyrene was 17,000. Next, 50 parts of the obtained silicone macromonomer and
Copolymerization of 50 parts of MMA was carried out in the same manner as in Example 1,
85 parts of a silicone-based graft copolymer was obtained. This silicone-based graft copolymer was soluble in toluene, xylene, and thinner. As a result of analysis, the amount of silicone contained in this silicone-based graft copolymer was 43%.
The polystyrene equivalent number average molecular weight by GPC is
It was 49,000. A 10% thinner solution of the thus obtained silicone-based graft copolymer was prepared, and an acrylic clear paint containing the silicone-based graft copolymer was prepared in the same manner as in Example 1. Next, this silicone-based graft copolymer-containing acrylic clear paint was applied 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 55 μm was obtained. The surface of the coating film was smooth and free of pinholes. The contact angle of the surface of the coating film in contact with water with water was 102°. The contact angle of the surface in contact with air with water of the coating film obtained from the acrylic clear paint not containing the silicone graft copolymer was 74°.

Claims (1)

[Scope of Claims] 1. A method for producing a coating composition by dissolving a silicone-based graft copolymer in an organic solvent solution of a film-forming resin, wherein the silicone-based graft copolymer is represented by general formula (A). Copolymerizing a high molecular weight silicone monomer obtained by reacting a silicone living polymer obtained by anionically polymerizing a cyclic siloxane shown with a compound represented by general formula (B) with another radically polymerizable monomer. A method for producing a coating composition, characterized by using a silicone-based graft copolymer. (A) (In the formula, R ₁ is a methyl group, ethyl group, or phenyl group, and P is 3 or 4.) (B) or (In the formula, R ₂ is hydrogen or a methyl group, m is 0 or 1, R ₃ and R ₄ are methyl, ethyl, or phenyl groups, n is an integer from 1 to 3, and is 0 when m = 0. An integer between ~2 and 2 if m=1.)