JP6135861B2 - Coating composition - Google Patents

Description

The present invention relates to a coating composition.

In recent years, demands for using biomass have increased further for chemical raw materials and chemical materials. As the biomass, for example, natural rosin, various modified rosins obtained by modifying the natural rosin, derivatives thereof, and the like are known, and further multi-functionality and advanced utilization of the rosin derivative are expected.

Patent Document 1 discloses an invention relating to a method for producing a poly (silyl ester) containing a polymerized rosin as a constituent component and a method for using the compound. More specifically, a method for producing a reaction product of a polymerized rosin and a polyoxysilyl derivative is described. Examples of the use of the reaction product include antifouling coatings, release control applications, bioactive agents and the like. ing.

  By the way, a hydrolyzable silane compound and a silane polymer mainly composed of a condensate thereof are generally excellent in heat resistance, curability, and the like, and thus are awarded for various coating applications. However, the coating film is generally high in hardness and excellent in adhesion to an inorganic substrate, but has low flexibility so that cracking occurs or adhesion to an organic substrate is insufficient. Has been pointed out (see Patent Documents 2 to 4). For this reason, as a means for imparting flexibility to the coating film, techniques for introducing an organic component (for example, hybridization, blending with an organic resin, etc.) have been studied, but there is still room for improvement.

JP-T-2006-521438 JP-A-7-171408 Japanese Patent Laid-Open No. 8-259891 JP 2003-96394 A

An object of the present invention is to provide a novel and useful coating composition having a polymerized rosin skeleton from the viewpoints of environmental considerations and coating film properties.

The present inventor has intensively studied paying attention to a polymerized rosin compound (polymerized rosin, polymerized rosin alcohol) under the present circumstances where an environmentally friendly and highly useful rosin derivative is required. As a result, it has been found that the reaction product obtained from the polymerized rosin compound and the specific silane compound can be a high-performance coating agent, and the present invention has been completed.

That is, the present invention provides an epoxy ring-opening addition reaction product (1) comprising a polymerized rosin and an epoxy group-containing polydiorganosiloxane and / or a dealcoholization reaction product (2) comprising a polymerized rosin alcohol and an alkoxy group-containing polydiorganosiloxane. The present invention relates to a coating composition containing Hereinafter, if necessary, the epoxy ring-opening addition reaction product (1) is the reaction product (1), the dealcoholization reaction product (2) is the reaction product (2), and the epoxy group-containing polydiorganosiloxane is added. Siloxane (A) and alkoxy group-containing polydiorganosiloxane are abbreviated as siloxane (B), respectively.

According to the present invention, an environmentally friendly coating composition having excellent coating film properties can be provided. Since the coating composition has an excellent balance of various physical properties such as hardness, flexibility, heat resistance, water resistance and salt water resistance, it is suitable for various coating applications. In addition, since the reaction product (1) and the reaction product (2) are both excellent in resistance to photocatalysts, the coating composition of the present invention can be used as an environmentally friendly and high-performance photocatalyst paint.

The reaction product (1) used in the coating composition of the present invention is obtained from polymerized rosin and siloxane (A), and the reaction product (2) is obtained from polymerized rosin alcohol and siloxane (B). is there. The properties of the reaction product (1) and the reaction product (2) are not particularly limited, but the weight average molecular weight is 3,000 to 80,000 in terms of polystyrene measured by gel permeation chromatography, preferably The thing of 3,500-50,000 is suitable. The reaction product (1) usually has an acid value of 10 mgKOH / g or less, preferably 5 mgKOH / g or less, and the reaction product (2) has a hydroxyl value of 10 mgKOH / g or less, preferably 5 mgKOH / g. g or less.

The properties of the polymerized rosin, which is a component of the reaction product (1), are not particularly limited. However, when color tone or the like is important according to the use, the properties may be appropriately selected. For example, as a polymerized rosin, the color tone is Gardner (according to JIS K5902) 3 or less, preferably 2 or less, more preferably Hazen level (according to JIS K0071-1), and softening point (according to JIS K2207 (ring and ball method)) is 145. -200 ° C, preferably 150-190 ° C, acid value (according to JIS K2501) of 160-185 mgKOH / g, preferably 165-185 mgKOH / g, and dimer content of 60% by weight or more Preferably, 80% by weight or more can be suitably used (hereinafter referred to as a specific polymerized rosin).

In order to obtain a specific polymerized rosin, it is preferable to use a purified rosin obtained by a method such as distillation or recrystallization as a starting material, or to hydrogenate the polymerized rosin thus obtained. The method for producing the specific polymerized rosin is not particularly limited, and various known methods can be employed. Examples thereof include a method using a polymer having a pendant sulfone group as a polymerization reaction catalyst (Japanese Patent Laid-Open No. 2006-45396); a method using formic acid, p-toluenesulfonic acid, zinc chloride and the like.

The properties of the polymerized rosin alcohol, which is a component of the reaction product (2), are not particularly limited, but may be appropriately selected depending on the application. For example, as polymerized rosin alcohol, the color tone is Gardner 3 or less, preferably 2 or less, more preferably Hazen level, softening point is 110 to 150 ° C., preferably 120 to 140 ° C., and hydroxyl value (according to JIS K0070). Is 130-180 mgKOH / g, preferably 140-170 mgKOH / g, acid value is 3 mgKOH / g or less, preferably 1 mgKOH / g or less, and dimer content is 60% by weight or more, more preferably 80% by weight. % Or more (hereinafter referred to as specific polymerized rosin alcohol).

The specific polymerized rosin alcohol can be obtained by applying various known hydrogenation methods and hydrogenating and reducing unsaturated bonds and carboxyl groups in the polymerized rosin. An example of an industrial hydrogenation method is a method of hydrogenating a resin acid methyl ester with a copper chromium catalyst in the presence of a heavy metal catalyst, a hydrogenation of a resin acid methyl ester with a copper chromium catalyst at a high temperature and high pressure of about 300 ° C. A method of directly hydrogenating dissolved rosin with Raney nickel, a method of hydrogenating at high temperature and high pressure using a copper, cobalt, nickel-based catalyst and reducing to alcohol. The rosin alcohol thus obtained is a mixture containing tetrahydroabiethyl alcohol, dihydroabiethyl alcohol, dehydroabiethyl alcohol and the like.

As the siloxane (A) which is a component of the reaction product (1), at least one end (one end or both ends) of the molecule is a γ-glycidoxypropyl group, a 3,4-epoxycyclopentyl group, 3 , 4-epoxycyclohexyl group, 2- (3,4-epoxycyclopentyl) ethyl group, 2- (3,4-epoxycyclohexyl) ethyl group, and the like, which are linear and branched. Any of these may be used. As the siloxane (A), polydimethylsiloxane containing the epoxy group is preferable from the viewpoint of availability and stability. The number of repeating units (R ₂ SiO) of siloxane (A) is not particularly limited, and can be appropriately selected according to the intended use, and each of oily and polymer-like substances can be used alone or in combination of two or more. be able to. The number of units is usually about 5 to 50, preferably 10 to 30 in terms of the viscosity of the siloxane (A) and the solution viscosity of the coating composition obtained using the siloxane (A). Specific examples of polydimethylsiloxane having an epoxy group at one end include X-22-173DX manufactured by Shin-Etsu Chemical Co., Ltd., and specific examples of polydimethylsiloxane having an epoxy group at both ends. And KF-105, X-22-163, X-22-163A, X-22-163B, X-22-163C, manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

Examples of the siloxane (B) that is a component of the reaction product (2) include various equivalent compounds having an alkoxy group at at least one end (one end or both ends) of the molecule. Any of branching may be sufficient. The siloxane (B) is preferably a lower (carbon number 1 to 4) alkoxy group-containing polydimethylsiloxane from the viewpoint of availability. The number of repeating units (R ₂ SiO) of the siloxane (B) is not particularly limited, and can be appropriately selected according to the intended use, and each of the oily and polymeric ones can be used alone or in combination of two or more. be able to. The number of units is in the same range as those in siloxane (A). Specific examples of the siloxane (B) include KR213, KR217, KR9218, KR500, and X40-9225 manufactured by Shin-Etsu Chemical Co., Ltd., DC3074, DC3037, and SR2402 manufactured by Toray Dow Corning Co., Ltd. XC96-C2813, XC96-B0446, XR31-B1410, XR31-B2733 and the like manufactured by the company may be mentioned.

  The reaction product (1) is produced by charging the polymerized rosin and the siloxane (A) in a predetermined ratio in a reaction vessel and, if necessary, performing an epoxy ring-opening addition reaction in the presence of an esterification catalyst and an organic solvent. Done. The reaction temperature is about 50 to 130 ° C., and the reaction time is about 1 to 15 hours. In addition, as long as the performance of the obtained reaction product (1) is not impaired, a part of the polymerized rosin may be substituted with another dibasic acid, and the substitution rate is 30 mol% or less of the polymerized rosin. . Examples of the dibasic acid include aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, phthalic anhydride, and isophthalic acid. Examples thereof include aromatic dibasic acids such as acid, terephthalic acid, 1,6-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid.

The charge ratio is such that [number of epoxy groups in siloxane (A)] / [number of carboxyl groups in polymerized rosin] (equivalent ratio) is 0.5 / 1 to 2/1, preferably 0.8 / 1 to 1.2. / 1. When the amount ratio is less than the lower limit, the acid value of the reaction product (1) obtained is increased, and when the amount ratio exceeds the upper limit value, residual epoxy groups in the reaction product (1). There is a tendency to increase.

Specific examples of the transesterification catalyst include organic amines such as dibutyltin dilaurate, dibutyltin oxide, p-toluenesulfonic acid, and imidazole. The amount of the esterification catalyst used is generally 0.01 to 5% by weight, preferably 0.05 to 1% by weight, based on the polymerized rosin.

As said organic solvent, what is inactive with respect to the epoxy group in siloxane (A) and the carboxyl group in polymerized rosin can be used, for example, ester solvents such as ethyl acetate, butyl acetate and isobutyl acetate; xylene, toluene Aromatic hydrocarbon solvents such as anisole; ketone solvents such as methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, isophorone, methyl ethyl ketone; isopropyl alcohol, n-butanol, ethylene glycol, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether Alcohol solvents such as mineral spirits, saturated hydrocarbon solvents such as mineral spirits, octane and cyclohexane; dioxane, dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, Polar solvent containing no active hydrogen group such Rahidorofuran the like. These may be used alone or in combination of two or more.

  The reaction product (2) is produced by charging the reaction vessel with polymerized rosin alcohol and siloxane (B) at a predetermined ratio, and if necessary, dealcoholization reaction at room temperature to about 120 ° C. in the presence of a catalyst and an organic solvent. Is done. In addition, as long as the performance of the reaction product (2) obtained is not impaired, a part of the polymerized rosin alcohol may be substituted with another dihydric alcohol, and the substitution rate is 30 mol% or less of the polymerized rosin alcohol. Is done. Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, Examples include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, and hydrogenated bisphenol A.

The charging ratio is such that [number of alkoxy groups in siloxane (B)] / [number of hydroxyl groups in polymerized rosin alcohol] (equivalent ratio) is 0.5 / 1 to 2/1, preferably 0.8 / 1 to 1.. 2/1. When the corresponding amount ratio is less than the lower limit value, the hydroxyl value of the reaction product (2) to be obtained is increased, and when the corresponding amount ratio exceeds the upper limit value, the remaining alkoxy groups in the reaction product (2). The number of people tends to increase.

As the catalyst, a known dealcoholization catalyst such as a basic compound, an acidic compound, or a metal compound that does not open the epoxy group of the siloxane (B) can be used. Examples of the basic compound include ammonia, organic amines, alkali metal and alkaline earth metal hydroxides, and alkali metal alkoxides. Examples of the acidic compound include organic acids such as acetic acid and propionic acid, and inorganic acids such as hydrochloric acid and sulfuric acid. As the metal compound, for example, organic tin and organic acid tin are preferable, and specifically, dibutyltin dilaurate, tin octylate and the like are preferable. Moreover, as the organic solvent, the same organic solvent as that used in the production of the reaction product (1) can be used.

  In the reaction product (1) obtained as described above, the polymerized rosin site constitutes a hard segment, and the siloxane (A) site constitutes a soft segment. In the reaction product (2), the polymerized rosin alcohol site constitutes a hard segment, and the siloxane (B) site constitutes a soft segment. Thus, since the reaction products (1) and (2) have a bulky hard segment structure derived from a polymerized rosin site or a polymerized rosin alcohol site, the utility value is great as a high-performance resin material.

In addition, when the reaction product (1) has a residual epoxy group derived from the siloxane (A), it can be a curable material using the epoxy group. When a curable composition such as an epoxy resin composition is prepared using the material, various compounds such as a solvent, a curing agent, a pigment, a filler, and an epoxy resin can be appropriately blended depending on the use. Moreover, when the reaction product (2) has a residual alkoxy group derived from the siloxane (B), it can be a curable material utilizing the alkoxy group. A curable composition such as a hydrolyzable / condensable curable composition can be prepared using the material, and a strong cured product by so-called sol-gel reaction can be obtained.

In addition to the reaction product (1) and the reaction product (2), the coating composition of the present invention can contain a hydrolyzable silane compound, a curing catalyst, a solvent, a pigment, and the like, if necessary. If necessary, dispersion stabilizers, surfactants, antifoaming agents, plasticizers, antioxidants, UV absorbers, light stabilizers, fragrances, curing agents, neutralizing agents, rust preventives, antifungal agents, film forming An agent or the like may be added.

The said hydrolysable silane compound can be mix | blended when improving the sclerosis | hardenability of the coating composition of this invention further. The silane compound is not particularly limited and various known ones can be used. For example, phenylmethyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, phenylmethyldimethoxysilane, diphenyldimethoxysilane, diphenyl Dialkoxysilanes such as diethoxysilane; methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, methyltripropoxysilane, ethyltripropoxysilane, n-propyltrimethoxysilane, n-propyltri Ethoxysilane, n-propyltripropoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, isopropyltripropoxysilane, methyltributoxy Silane, ethyltributoxysilane, n-propyltributoxysilane, isopropyltributoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltributoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltri Trialkoxysilanes such as ethoxysilane; tetraalkoxysilanes such as tetraethoxysilane, tetraisopropoxysilane, tetra n-propoxysilane, tetrabutoxysilane, tetramethoxysilane, dimethoxydiethoxysilane; and further initial condensation of the silane compound Such as things. In addition, so-called silane coupling agents are also included in the hydrolyzable silane compound. For example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl). ) Epoxy functional alkoxysilanes such as ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane; N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxy Amino-functional alkoxysilanes such as silane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane; mercaptofunctional alkoxy such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane Examples include silane. These may be used alone or in combination of two or more. Among these, the trialkoxysilane, tetraalkoxysilane and their initial condensates, and the silane coupling agent are preferable from the viewpoint of curability. These blending ratios in the coating composition are not necessarily limited and can be determined according to the intended use, and are generally 50 parts by weight or less with respect to 100 parts by weight of the reaction product. When the usage-amount of a hydrolysable silane compound exceeds 50 weight part, there exists a tendency for the flexibility and impact resistance of the coating film obtained to fall.

The curing catalyst can be used to further improve the curing rate of the coating composition of the present invention. As the catalyst, a conventionally known silanol condensation catalyst can be used without any particular limitation. Specific examples of the catalyst include titanic acid esters such as tetrabutyl titanate and tetrapropyl titanate; tin carboxylates such as dibutyltin dilaurate, dibutyltin maleate, dibutyltin diacetate, tin octylate and tin naphthenate; aluminum tris Organoaluminum compounds such as acetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate; butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexyl Amine, benzylamine, diethylaminopropylamine, xylylenediamine, triethylenediamine, guanidi , Diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole, 1,8-diazabicyclo (5.4.0) undecene-7 ( Amine compounds such as DBU). These may be used alone or in combination of two or more. These compounding ratios in the coating composition are not necessarily limited and can be determined according to the intended use, and are generally about 0.1 to 10 parts by weight with respect to 100 parts by weight of the reaction product.

  The organic solvent can be used when it is necessary to adjust the viscosity of the coating composition of the present invention, and the same organic solvent as used in the production of the reaction product (1) or the reaction product (2) is appropriately selected. Use it. When considering the viscosity stability with time of the coating composition, alcohols such as ethanol and isopropyl alcohol are preferably used. These blending ratios in the coating composition are not necessarily limited, and can be determined in consideration of the intended use and the viscosity of the reaction product to be used, and generally about 50 to 150 parts by weight with respect to 100 parts by weight of the reaction product. It is.

  The pigment and filler that can be blended in the coating composition of the present invention are not particularly limited, and various known color pigments, extender pigments, rust preventive pigments, fillers, and the like can be used. Titanium dioxide, Bengala, carbon black, etc. as coloring pigments, kaolin, aluminum silicate, precipitated barium sulfate, silica, precipitated calcium carbonate, etc. as extender pigments, and aluminum phosphomolybdate as rust preventive pigments , Strontium chromate, basic lead silicate, lead chromate and the like. These may be used alone or in combination of two or more. These compounding ratios in the coating composition are not necessarily limited and can be determined according to the intended use, and are generally about 10 to 150 parts by weight with respect to 100 parts by weight of the reaction product.

When the coating composition of the present invention is used as a photocatalyst paint, it is necessary to select a photocatalytic one as a pigment. The photocatalytic pigment is not particularly limited as long as it has photocatalytic activity. For example, anatase type titanium oxide, brookite type titanium oxide, rutile type titanium oxide, tin oxide, zinc oxide, dibismuth trioxide, tungsten trioxide, Examples thereof include ferric oxide and strontium titanate. These may be used alone or in combination of two or more. Among these, anatase type titanium dioxide is preferable.

The coating composition of the present invention is prepared by mixing and dispersing in a sand mill, a homogenizer, a ball mill, a roll mill, a paint shaker, an ultrasonic disperser, a blade-type stirrer, a magnetic stirrer, a high-speed disperser, an emulsifier, and the like. .

The substrate to which the coating composition of the present invention is applied is not particularly limited, and examples thereof include inorganic materials, metal materials, organic materials, and composites thereof. More specifically, metal, ceramics, glass, plastic, wood, stone, cement, concrete, fiber, fabric, paper, combinations thereof, laminates thereof, painted bodies thereof, and the like.

Hereinafter, the present invention will be described more specifically with reference to production examples, examples, and comparative examples, but the present invention is not limited to these examples. Parts and% are based on weight unless otherwise specified. The color tone, softening point, acid value, hydroxyl value, and dimer content of the polymerized rosin and polymerized rosin alcohol used in the present invention and the weight average molecular weight of the reaction product are measured by the following methods.

(Color tone)
Gardner chromaticity was measured according to JIS K5902, and Hazen chromaticity was measured according to JIS K0071-1.
(Softening point)
The measurement was performed according to JIS K2207 (ring and ball method).
(Acid value)
The measurement was performed according to JIS K2501.
(Hydroxyl value)
The measurement was performed according to JIS K0070.
(Dimer content)
It calculated | required by the HLC measuring method. The measurement conditions are as follows.
Column: ODS (manufactured by JASCO Corporation)
Solvent: methyl alcohol / 0.01% phosphoric acid = 9/1 (volume ratio)
Flow rate: 1 ml / min,
Detector: differential refractometer (manufactured by JASCO Corporation)

(Weight average molecular weight)
The polystyrene conversion value by gel permeation chromatography (GPC) measurement is shown.

Production Example 1 (Synthesis of reaction product (1))
In a reactor equipped with a stirrer, a thermometer, a cooling pipe and a nitrogen introduction pipe, 240 parts of polymerized rosin (color Gardner 1, softening point 150 ° C., acid value 178 mg KOH / g, dimer content 65%), siloxane ( A) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KF-105”: epoxy equivalent 490 g / equivalent) 490 parts, esterification catalyst (dibutyltin dilaurate) 0.6 parts, and a predetermined amount of solvent (xylene / acetic acid) After adding ethyl = 1/1), the mixture was allowed to undergo an epoxy ring-opening addition reaction at 110 ° C. for 8 hours with stirring under a nitrogen stream, and then a predetermined amount of the solvent was added to react with a non-volatile content of 50%. A product (1) solution was obtained (hereinafter referred to as reaction product (1-1)). The reaction product (1-1) had a weight average molecular weight of 8,500 and an acid value (in terms of nonvolatile content, the same applies hereinafter) of 2.5 mgKOH / g.

Production Example 2 (Synthesis of reaction product (1))
The same procedure as in Production Example 1 except that 270 parts of hydrogenated polymerized rosin (color tone Hazen 100, softening point 167 ° C., acid value 178 mgKOH / g, dimer content 80%) was used instead of 240 parts of the polymerized rosin. The reaction product (1) solution having a nonvolatile content of 50% was obtained (hereinafter referred to as reaction product (1-2)). The reaction product (1-2) had a weight average molecular weight of 9,000 and an acid value of 2.1 mgKOH / g.

Production Example 3 (Synthesis of reaction product (2))
To a reactor equipped with a stirrer, a thermometer, a separator-equipped cooling pipe and a nitrogen introduction pipe, polymerized rosin alcohol (color tone Gardner 2, softening point 130 ° C., hydroxyl value 170 mgKOH / g, acid value 1.6 mgKOH / g, two 230 parts of polymer content 65%, siloxane (B) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KR-217”: methoxy group content 25.4%, methoxy equivalent 263 g / equivalent) 263 parts, desorption After adding 0.6 parts of an alcohol catalyst (dibutyltin dilaurate) and a predetermined amount of solvent (xylene / ethyl acetate = 1/1), a methanol removal reaction is performed at 90 ° C. for 6 hours while stirring in a nitrogen stream. As a result, a reaction product (2) solution having a nonvolatile content of 50% was obtained (hereinafter referred to as reaction product (2-1)). The reaction product (2-1) had a weight average molecular weight of 12,000 and a hydroxyl value (in terms of nonvolatile content, the same applies hereinafter) of 3.1 mgKOH / g.

Production Example 4 (Synthesis of reaction product (2))
In Production Example 3, the following polymerized rosin alcohol (color tone Gardner 1, softening point 150 ° C., hydroxyl value 155 mgKOH / g, acid value 0.8 mgKOH / g, dimer content 80%) 258 instead of the polymerized rosin alcohol The reaction was carried out in the same manner except that the part was used to obtain a reaction product (2) solution having a nonvolatile content of 50% (hereinafter referred to as reaction product (2-2)). The reaction product (2-2) had a weight average molecular weight of 14,000 and a hydroxyl value of 2.4 mgKOH / g.

Comparative Production Example 1 (Synthesis of Comparative Reaction Product)
In Production Example 1, the reaction was performed in the same manner except that 83 parts of isophthalic acid was used instead of 300 parts of the polymerized rosin to obtain a comparative reaction product solution having a non-volatile content of 50% (hereinafter referred to as Comparative Reaction Product 1). Called). Comparative reaction product 1 had a weight average molecular weight of 7,200 and an acid value of 1.5 mgKOH / g.

Comparative Production Example 2 (Synthesis of Comparative Reaction Product)
In Production Example 1, the reaction was performed in the same manner except that 72 parts of 1,4-cyclohexanedimethanol was used in place of the polymerized rosin alcohol to obtain a comparative reaction product solution having a non-volatile content of 50% (hereinafter referred to as comparative reaction). Product 2). Comparative reaction product 2 had a weight average molecular weight of 10,500 and a hydroxyl value of 0.9 mgKOH / g.

Examples 1-8 (Preparation of photocatalyst paint)

Using each reaction product obtained in Production Examples 1 to 4 and Comparative Production Examples 1 and 2, the compositions (parts by weight) as shown in Table 1 were mixed, and then the mixture was kneaded with a paint shaker. Paints were obtained (referred to as paints 1 to 10 in order).

In Table 1, titanium oxide is titanium oxide powder for photocatalyst (Ishihara Sangyo Co., Ltd., trade name “ST-01”), and PTMMS is poly (methyltrimethoxysilane) (Tama Chemical Co., Ltd., trade name). “MTMS-A”), PTMS is a tetramethoxysilane condensate (manufactured by Tama Chemical Co., Ltd., trade name methyl silicate 51), and a curing catalyst is an organic titanium compound (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “DX”). -175 ") respectively.

(Preparation of photocatalytic coating)
Each of the coating plates 1 to 10 was applied to a degreased steel plate and a glass plate with a bar coater and then allowed to stand at room temperature for 5 days to obtain each test plate on which a photocatalytic coating film (film thickness: 20 μm) was formed. .

(Evaluation method and evaluation criteria)
About each test board (base material: steel plate), the coating-film performance was evaluated in accordance with the following method. Each evaluation result is shown in Table 2.
Pencil hardness: Conforms to JIS K5400.
Adhesion: Conforms to JIS K5400 (cross cut cellophane tape peel test).
Impact resistance: Conforms to JIS K5600 (DuPont impact test: 1/2 inch x 500 g load).
Water resistance: Based on JIS K5600 (observation of the surface state after immersion for 5 days at room temperature).
Salt water resistance: Conforms to JIS K5400 (salt spray test, rust width of cross-cut part)
Contamination resistance: The appearance (contamination level) after standing outdoors for 6 months was visually evaluated.

In addition, regarding the adhesiveness, each test plate (base material: glass plate) was evaluated in the same manner as described above, but all were good.

From the evaluation results in Table 2, it is clear that the coating composition of the present invention is environmentally friendly and has an excellent coating film performance balance.

Claims (11)

Coating composition containing epoxy ring-opening addition reaction product (1) comprising polymerized rosin and epoxy group-containing polydiorganosiloxane and / or dealcoholization reaction product (2) comprising polymerized rosin alcohol and alkoxy group-containing polydiorganosiloxane object. The polymerized rosin has a color tone of Gardner 3 or less, a softening point of 145 to 200 ° C, an acid value of 160 to 185 mgKOH / g, and a dimer content of 60% by weight or more. Coating composition. Polymerized rosin alcohol having a color tone of Gardner 3 or less, a softening point of 110 to 150 ° C., a hydroxyl value of 120 to 140 mgKOH / g, an acid value of 3 mgKOH / g or less, and a dimer content of 60% by weight or more The coating composition according to claim 1. The coating composition according to claim 1, wherein the epoxy group-containing polydiorganosiloxane is a polydimethylsiloxane having an epoxy group at at least one terminal. The coating composition according to claim 1, wherein the alkoxy group-containing polydiorganosiloxane is a polydimethylsiloxane having an alkoxy group at at least one terminal. The coating composition according to any one of claims 1 to 5, wherein the reaction product (1) has a weight average molecular weight of 3,000 to 80,000 and an acid value of 10 mgKOH / g or less. The coating composition according to any one of claims 1 to 6, wherein the reaction product (2) has a weight average molecular weight of 3,000 to 80,000 and a hydroxyl value of 10 mgKOH / g. Furthermore, the coating composition in any one of Claims 1-7 containing at least 1 sort (s) chosen from the group which consists of a hydrolysable silane compound, a curing catalyst, a solvent, and a pigment. The hydrolyzable silane compound is at least one selected from the group consisting of trialkoxysilane, trialkoxysilane initial condensate, tetraalkoxysilane, tetraalkoxysilane initial condensate, and silane coupling agent. Coating composition. The coating composition according to claim 8, wherein the curing catalyst is at least one selected from a titanate ester, a tin carboxylate, an organoaluminum compound, and an amine compound. The coating composition according to claim 8, wherein the pigment is a photocatalytic pigment.