JP5086546B2 - Paint finishing method - Google Patents

Description

  The present invention relates to a method for finishing the surface of a plasticizer-containing material such as a sealing material, and is mainly applied to the construction field.

  In general, the sealing material is filled in the joints and gaps between various base materials and members, consistent with the rain, imparting waterproofness and airtightness, and different members such as glass and window frames, window frames and panels, etc. Used for the purpose of bonding and fixing between. Further, in renovation / renovation work, it is used for the purpose of imparting waterproofness and airtightness, for example, for repairing a crack generated in a base material over time.

  However, although these sealing materials are excellent in waterproofness and airtightness, sticking (tack) tends to remain in the exposed part of the surface, so that contaminants such as dust and dust adhere to it over time. It may damage the aesthetics. Furthermore, in addition to the surface contamination of the sealing material itself, there may be a phenomenon in which the base material and members around the joint are contaminated by the seepage of the plasticizer contained in the sealing material. In addition, when various paints are applied as finishing materials for the purpose of aesthetics and protection on these base materials and members, the plasticizer contained in the sealing material moves to the finishing material coating film to plasticize the coating film. In some cases, contamination due to adhesion of dust or the like is induced.

  Various methods for preventing such a sealing material contamination phenomenon have been disclosed. For example, JP-A-7-82548 (Patent Document 1) discloses an inorganic coating containing a hydrolyzed condensate of organoalkoxysilane, colloidal silica, etc. on the surface of the sealing material as a method for preventing the surface of the sealing material from being stained. Disclosed are methods for painting materials

JP 7-82548 A

  However, inorganic coating materials such as those described in the above-mentioned patent documents usually form a very hard coating film, and therefore can follow the movement of the sealing material corresponding to the movement of the substrate or member. It is difficult and has practically improved points such as cracks in the coating film.

  The present invention has been made in view of the above-described problems, and an object thereof is to suppress contamination and cracking of a coating film in the finish of the surface of a plasticizer-containing material such as a sealing material. .

  As a result of intensive studies to achieve the above object, the present inventor has conceived that the surface of a sealing material or the like is covered with a top coating material containing a specific coating resin and a modified silicate compound as essential components. The invention has been completed.

That is, the present invention has the following characteristics.
1. In a paint finishing method in which the surface of a plasticizer-containing material is coated with a top coat material,
The plasticizer-containing material is an architectural sealant;
As the coating material,
With respect to 100 parts by weight of the solid content of the coating resin having a glass transition temperature of -20 to 60 ° C., 0.05 to 20 parts by weight of a silicate compound as a stain resistance improving component in terms of SiO _{2 is} contained as the silicate compound. , tetraalkoxysilane condensates (a) is seen containing a modified silicate compound modified with polyhydric alcohol molecule weight have 3 or more hydroxyl groups in one molecule is less than 500 (b),
A coating finishing method comprising using a top coating material containing an amine compound in addition to the silicate compound .

  According to the present invention, in the finishing of the surface of a plasticizer-containing material such as a sealing material, the coating film contamination caused by the migration of the plasticizer to the coating film surface is suppressed while ensuring the followability to the coated surface. Can do. The present invention can be applied to the surface finishing of plastic material-containing materials such as vinyl building materials, vinyl chloride coated products, and vinyl chloride molded products in addition to sealing materials.

  Hereinafter, the best mode for carrying out the present invention will be described.

[Coating material]
The coating material used in the present invention comprises a coating resin having a glass transition temperature of -20 to 60 ° C. and a silicate compound as essential components, and the tetraalkoxysilane condensate (a) (hereinafter referred to as “(a)” as the silicate compound. “Component”) includes a modified silicate compound modified with polyhydric alcohol (b) (hereinafter referred to as “component (b)”) having three or more hydroxyl groups in one molecule and a molecular weight of less than 500. In the present invention, by using such a specific topcoat material, the antifouling property and cracking prevention property of the coating film in the surface coating finish of the plasticizer-containing material can be sufficiently enhanced.

Of the essential components, first, the modified silicate compound will be described in detail.
Examples of the component (a) include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, tetraisobutoxysilane, tetrasec-butoxysilane, and tetra t-butoxysilane. , Tetraphenoxysilane, monoethoxytrimethoxysilane, monobutoxytrimethoxysilane, monopentoxytrimethoxysilane, monohexoxytrimethoxysilane, dimethoxydiethoxysilane, dimethoxydibutoxysilane and the like. Among these, a tetramethoxysilane condensate and a tetraethoxysilane condensate are advantageous in terms of expressing stain resistance. In addition, the average condensation degree of (a) component is 1-100 normally, Preferably it is about 4-20.

In the present invention, a polymerized silicate compound can be obtained by modifying the component (a) with the component (b). Such a modified silicate has a high orientation on the coating film surface, and works extremely effectively to improve the stain resistance, particularly to improve the stain resistance at the initial stage of coating film formation.
As the component (b), a polyhydric alcohol having 3 or more hydroxyl groups in one molecule and having a molecular weight of less than 500 can be used. Examples of such component (b) include glycerin, trimethylolpropane, 1,2,4-butanetriol, 2,3,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, dipenta. Examples include erythritol. Also, among polyol compounds such as polyester polyol, polyether polyol and polyacryl polyol, those having a molecular weight satisfying the above conditions can be used.

  As the component (b) in the present invention, a compound having three hydroxyl groups in one molecule is particularly suitable, and a compound having a molecular weight of 200 or less (more preferably 150 or less) is preferred. In particular, glycerin is preferred in the present invention. In such a modified silicate modified with the component (b), since the hydroxyl group is close in the component (b), the hydroxyl group tends to remain due to steric hindrance during the reaction with the component (a). This hydroxyl group is considered to be advantageous in the effect of improving stain resistance, the effect of preventing plasticizer migration, adhesion, pigment miscibility, and compatibility with other components.

  In order to modify the component (a) with the component (b), a transesterification reaction may be used. When performing the transesterification reaction, a transesterification catalyst may be used as necessary. As such a transesterification catalyst, an organic tin compound, an organic titanate compound, a phosphoric acid compound, an acid anhydride, amines, etc. can be used, for example. Moreover, at the time of transesterification, it can also heat (usually about 50-150 degreeC). If necessary, the reaction can be carried out in the presence of a solvent.

  The modification ratio of the component (a) and the component (b) is such that the component (b) is in the range of 0.01 to 1 mol (preferably 0.05 to 0.3 mol) with respect to 1 mol of the component (a). It is desirable to do. By carrying out the modification at such a ratio, sufficient stain resistance can be obtained. If this ratio is too small, it becomes difficult to obtain the effect of improving the stain resistance. If it is too high, problems such as gelation may occur during modification.

  As the modified silicate compound in the present invention, a compound in which two or more kinds of alkoxyl groups having different carbon numbers are mixed is suitable. If the modified silicate compound is such a compound, the antifouling effect can be further enhanced. Examples of the combination of alkoxyl groups having different carbon numbers include a combination of a methoxy group having 1 carbon atom and an alkoxyl group having 2 to 12 carbon atoms, or a combination of an ethoxy group having 2 carbon atoms and an alkoxyl group having 3 to 12 carbon atoms. From the viewpoint of developing stain resistance at the initial stage of coating film formation. Among these, it is a combination of a methoxy group and an alkoxyl group having 2 to 12 carbon atoms (preferably 3 to 10 carbon atoms), and more than 5 equivalent% (preferably 5 to 50 equivalent%) of the total alkoxyl group. ) Is an alkoxyl group having 2 to 12 carbon atoms, or a combination of an ethoxy group and an alkoxyl group having 3 to 12 carbon atoms (preferably 3 to 10 carbon atoms). Of these, those in which 5 equivalent% or more (preferably 5 to 50 equivalent%) is an alkoxyl group having 3 to 12 carbon atoms are particularly suitable. In the case of having a branched alkoxyl group as an alkoxyl group having 3 to 12 carbon atoms (preferably 3 to 10 carbon atoms), it is particularly preferable in terms of surface hydrophilicity and crack resistance of the coating film.

  Specifically, in order to obtain a modified silicate having a methoxy group and an alkoxyl group having 2 to 12 carbon atoms, it can be produced by the method exemplified below.

(1) General formula Si (OR ¹ ) (OR ² ) (OR ³ ) (OR ⁴ )
(Wherein R ^{1 to} R ⁴ are a mixture of a methyl group and an alkyl group having 2 to 12 carbon atoms), an average condensation degree of 1 to 200 (preferably 2 to 100). ) To condense. The condensation method is a known method. In this case, other tetraalkoxysilanes can be mixed and condensed during the condensation.
Specific examples of the compound represented by the above general formula include, for example, monoethoxytrimethoxysilane, monobutoxytrimethoxysilane, monoisobutoxytrimethoxysilane, monopentoxytrimethoxysilane, monohexoxytrimethoxysilane, dimethoxydisilane. Examples include ethoxysilane, dimethoxydibutoxysilane, and the like, and condensates thereof.

(2) The tetramethoxysilane condensate is reacted with a monoalcohol having 2 to 12 carbon atoms to transesterify 5 equivalent% or more (preferably 5 to 50 equivalent%) of the methoxy group in the tetramethoxysilane condensate. Examples of the alcohol having 2 to 12 carbon atoms in this method include ethanol, n-propanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, t-butyl alcohol, n-amyl alcohol, and n-hexyl. Examples include alcohol, 2-ethyl-1-hexanol, n-heptanol, isoheptyl alcohol, n-octanol, 2-octanol, n-nonanol, n-decanol, n-undecyl alcohol, and n-dodecyl alcohol.

  In addition, in order to obtain a modified silicate having an ethoxy group and an alkoxyl group having 3 to 12 carbon atoms, instead of the methods (1) and (2), the following (1 ′) and (2 ′) are used, respectively. The method shown may be adopted.

(1 ′) General formula Si (OR ¹ ) (OR ² ) (OR ³ ) (OR ⁴ )
(Wherein R ^{1 to} R ⁴ are a mixture of an ethyl group and an alkyl group having 3 to 12 carbon atoms), an average condensation degree of 1 to 200 (preferably 2 to 100). ) To condense.

(2 ') The tetraethoxysilane condensate is reacted with a monoalcohol having 3 to 12 carbon atoms to transesterify 5 equivalent% or more (preferably 5 to 50 equivalent%) of the ethoxy group in the tetramethoxysilane condensate.

  According to the above method, a modified silicate in which alkoxy groups having different carbon numbers are mixed can be obtained, but the timing of the reaction is not particularly limited, and before or after the reaction with the component (b) or during the reaction. There may be.

The top coating material in the present invention is obtained by mixing the above-described modified silicate compound with a coating resin.
Examples of the coating resin include acrylic resins, polyester resins, polyether resins, polyurethane resins, acrylic silicon resins, fluororesins, vinyl acetate resins, epoxy resins, and composites thereof. These can be used alone or in combination of two or more. Examples of the form of the coating resin include solvent-soluble resins, non-water dispersible resins, water-soluble resins, water-dispersible resins, and solvent-free resins.

  Among these, the solvent-soluble resin and / or the non-aqueous dispersible resin is a non-aqueous solvent as a medium, and 50% by weight or more (preferably 60% by weight or more) of the total solvent is aliphatic carbonized. A so-called weak solvent resin which is hydrogen is preferred. Such weak solvent resins are less toxic and have higher work safety compared to strong solvent resins that use aromatic hydrocarbon solvents as the main solvent, and when applied to existing coatings. It has a feature that the occurrence of lifting can be suppressed. Examples of the aliphatic hydrocarbon include n-hexane, n-pentane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, and the like. In addition, terpine oil, mineral spirit, etc. Other aliphatic hydrocarbon solvents can also be used. In particular, those which do not contain toluene and xylene and correspond to the second petroleum having a flash point of 21 ° C. or higher are preferable in terms of safety and health. In the present invention, when such a weak solvent type resin is used as a coating resin, a particularly excellent effect can be obtained.

  The coating resin in the top coating material may have crosslinking reactivity. When the coating resin is a cross-linking resin, the strength, water resistance, weather resistance, adhesion and the like of the coating film can be improved. The cross-linking reaction type resin may be one that causes a cross-linking reaction by itself or one that causes a cross-linking reaction by a cross-linking agent that is separately mixed. Such crosslinking reactivity includes, for example, hydroxyl group and isocyanate group, carbonyl group and hydrazide group, epoxy group and amino group, aldo group and semicarbazide group, keto group and semicarbazide group, alkoxyl group, carboxyl group and metal ion, carboxyl group It can be imparted by combining a reactive functional group such as a group and a carbodiimide group, a carboxyl group and an epoxy group, a carboxyl group and an aziridine group, a carboxyl group and an oxazoline group. Among these, a hydroxyl group-isocyanate group crosslinking reaction type resin is preferable.

  The glass transition temperature of the coating resin is usually from -20 to 60 ° C, preferably from -10 to 50 ° C. When the Tg of the coating resin is within such a range, followability to the displacement of the surface to be coated is imparted, and the occurrence of cracks in the formed coating film can be suppressed. When the Tg of the coating resin is lower than −20 ° C., the antifouling property tends to be insufficient. Moreover, it becomes easy to generate | occur | produce a swelling in a coating film. When Tg is higher than 60 ° C., the displacement of the surface to be coated cannot be followed and the coating film may be cracked. In addition, Tg in this invention is a value calculated | required by the formula of Fox from the kind of monomer which comprises a synthetic resin emulsion, and its structural ratio.

  In the present invention, when the modified silicate compound is mixed with the coating resin, a silicate compound other than the modified silicate compound may be used in combination. It is desirable to be composed of a modified silicate compound.

  In the top coating material, by using the specific modified silicate as described above, it is possible to obtain a sufficient antifouling effect even with a small amount of the silicate compound as compared with the prior art, and the followability of the formed coating film to the ground. Also, it is advantageous in terms of crack prevention properties. That is, according to the present invention, it is possible to relatively reduce the amount of the silicate compound in the top coating material, and it is possible to design a paint that is extremely useful in practice.

The mixing ratio of the silicate compound, based on 100 parts by weight of the solid content of the coating resin, 0.05 to 20 parts by weight in terms of SiO ₂ (preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 It may be set within the range of (weight part). When the mixing ratio of the silicate compound is less than 0.05 parts by weight, the antifouling property is insufficient. On the other hand, when it exceeds 20 parts by weight, the followability of the formed coating film to the ground becomes insufficient, and cracks and the like are likely to occur.

The SiO ₂ conversion in the present invention means the weight remaining as silica (SiO ₂ ) when a compound having a Si—O bond such as alkoxysilane or silicate is completely hydrolyzed and then baked at 900 ° C. Expressed in minutes.
In general, alkoxysilanes and silicates have a property of reacting with water to cause a hydrolysis reaction to form silanol, and further causing a condensation reaction between silanols or between silanol and alkoxy. When this reaction is performed to the ultimate, silica (SiO ₂ ) is obtained. These reactions are RO (Si (OR) ₂ O) _n R + (n + 1) H ₂ O → nSiO ₂ + (2n + 2) ROH
(R represents an alkyl group. N is an integer.)
It is expressed by the reaction formula. The SiO ₂ conversion in the present invention is the conversion of the amount of the remaining silica component based on this reaction formula.

  In the top coating material, an amine compound can be mixed in addition to the above-described components. By mixing such an amine compound, it is possible to improve the adhesion when the top coat material is applied (recoated). Furthermore, the amine compound contributes to improvement of physical properties such as antifouling property and curability by interaction with the modified silicate compound.

  Examples of amine compounds include ethylamine, dimethylamine, diamylamine, cyclohexylamine, aniline, hexamethylenediamine, ethylenediamine, trimethylamine, triethylamine, tripropylamine, tributylamine, triphenylamine, dimethyldodecylamine, dimethylbenzylamine, dimethylcyclohexyl. In addition to amine, pyridine, morpholine, etc., ethanolamine, diethanolamine, dimethylethanolamine, N-methyldiethanolamine, triethanolamine and ethylphenylethanolamine-containing amine compounds such as triethylenediamine ([2,2,2] dia Abicyclooctane), tetramethylethylenediamine, pentamethyldiethylenetriamine, etc. Alkyl group-containing amine compound, aminomethyl triethoxysilane, diamino methyl diethoxy silane, .gamma.-amino isobutyl trimethoxy silane, alkoxysilyl group-containing amine compounds such as .gamma.-aminopropyl methyl diethoxy silane, and the like.

  In the present invention, as the amine compound, bis (2,2,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1- Octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2 , 2,6,6-pentamethyl-4-piperidyl), tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2 , 2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate and the like can also be used.

  As the amine compound, an amine compound having a base dissociation constant pKb of 3 or more and 11 or less (preferably 4 or more and 8 or less) is particularly preferable. By using such a compound, physical properties such as recoating property, antifouling property and curability can be further enhanced.

  The mixing ratio of the amine compound is usually 0.01 to 20 parts by weight, preferably 0.02 to 5 parts by weight with respect to 100 parts by weight of the solid content of the coating resin. Within such a range, sufficient effects can be obtained in recoating properties, antifouling properties, curability and the like, and it is also preferable in terms of securing the pot life of the top coating material.

  In the top coating material in the present invention, in addition to the above-mentioned components, a pigment can also be included. As the pigment, color pigments, extender pigments and the like that can be generally blended into paints can be used. The mixing ratio of such a pigment is usually 5 to 1000 parts by weight, preferably 10 to 500 parts by weight, and more preferably 10 to 100 parts by weight with respect to 100 parts by weight of the solid content of the coating resin. If the mixing ratio of the pigment is too high, caution is required because cracks may occur in the coating film.

Examples of color pigments include titanium oxide, zinc oxide, carbon black, lamp black, bone black, graphite, black iron oxide, copper chrome black, cobalt black, copper manganese iron black, red potato, molybdate orange, permanent red, and permanent. Carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, first yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine, bitumen, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine Violet etc. are mentioned, These 1 type (s) or 2 or more types can be used. Moreover, an aluminum pigment, a pearl pigment, etc. can also be used.
Examples of extender pigments include heavy calcium carbonate, light calcium carbonate, kaolin, clay, porcelain clay, china clay, diatomaceous earth, hydrous finely divided silicic acid, talc, barite powder, barium sulfate, precipitated barium sulfate, barium carbonate, magnesium carbonate. , Silica powder, aluminum hydroxide, and the like, and one or more of these can be used. The particle diameter of the extender pigment in the top coating material is usually 50 μm or less, preferably 0.5 μm or more and 30 μm or less.

  The top coating material of the present invention can be mixed with various components that can be used in ordinary paints as long as the effects of the present invention are not significantly impaired. Examples of such components include antiseptics, antifungal agents, antibacterial agents, antifoaming agents, dispersants, thickeners, leveling agents, wetting agents, pH adjusting agents, adsorbents, ultraviolet absorbers, and antioxidants. , Catalysts, crosslinking agents and the like.

The form of the topcoat material in the present invention is not particularly limited as long as it comprises the above resin for paint and the modified silicate compound, but usually includes a main agent containing a resin for paint and a modified silicate compound. It is desirable to use a two-component paint made of a curing agent. Such a form is preferable in terms of ensuring the stability of the paint and exhibiting antifouling performance. Components such as coloring pigments and extender pigments may be uniformly mixed with the main agent by a conventional method.
When the coating resin has a crosslinking reactive group and a crosslinking agent capable of reacting with the reactive group is used, the crosslinking agent may be mixed with a curing agent. Specifically, when the coating resin has a hydroxyl group, an isocyanate compound can be mixed with the curing agent.

[Coating method]
The present invention can be applied mainly to the interior and exterior of buildings.
In the present invention, when coating is performed on the sealing material using the above-described top coating material, it can be carried out as follows.

  The surface to be coated is a surface formed of various base materials, and is a surface in which a sealing material is filled in a joint portion, a repair portion, or the like. Examples of the base material include concrete, siding board, lightweight cellular concrete (ALC) plate, extruded plate, porcelain tile, metal, glass, plastic and the like. These coated surfaces may have been subjected to some surface treatment (sealer, surfacer, filler, putty, etc.) or may have an existing coating film.

  As the sealing material, those containing a plasticizer are targeted, and specifically, silicone-based sealing materials, modified silicone-based sealing materials, polysulfide-based sealing materials, modified polysulfide-based sealing materials, acrylic urethane-based sealing materials, Examples thereof include a polyurethane sealant, an SBR sealant, and a butyl rubber sealant. These may be either a one-component form or a two-component form. The plasticizer content in the sealing material is usually about 0.1 to 50% by weight.

When the top coating material is applied to such a surface to be coated, the entire surface to be coated including the substrate surface and the sealing material surface is usually applied. When only the surface treatment of the sealing material is intended, the surface of the sealing material and its periphery may be applied about 3 to 10 mm wider than the width where the sealing material is placed. The coating amount of the top coating material is usually about 30 to 300 g / m ^{2 in} terms of solid content. As a coating method, methods such as brush coating, spray coating, and roller coating can be employed.

The present invention can also be applied to various materials containing a plasticizer such as vinyl building materials, vinyl chloride coated products, and vinyl chloride molded products in addition to the above-described sealing materials. Among these, vinyl building materials include wall materials, ceiling materials, floor materials, etc. containing vinyl chloride resin as a main component and further containing a plasticizer. Even when such a material is used as a target, coating may be performed by a method such as brush coating, spray coating, or roller coating so that the coating amount in terms of solid content is about 30 to 300 g / m ² .

  Examples and Comparative Examples are shown below to clarify the features of the present invention.

(Production of modified silicate compound)
・ Modified silicate (1)
As a catalyst, 52 parts by weight of n-butyl alcohol and 100 parts by weight of methyl silicate (hereinafter referred to as “tetraalkoxysilane condensate (1)”) having a weight average molecular weight of 1000, an average degree of condensation of about 8 and a non-volatile content of 100% After adding 0.03 part by weight of dibutyltin dilaurate and mixing, a demethanol reaction was performed at 75 ° C. for 8 hours to synthesize a tetraalkoxysilane condensate (2). The transesterification rate of this tetraalkoxysilane condensate (2) (ratio of n-butoxy groups to all alkoxyl groups) was 38 equivalent%, and the residual silica ratio obtained by firing at 900 ° C. was 43% by weight. It was.

  Next, 0.92 parts by weight of glycerin and 0.5 parts by weight of dibutyltin dilaurate are added to 100 parts by weight of the tetraalkoxysilane condensate (2) obtained by the above method. A time-demethanol reaction was performed to synthesize modified silicate (1). In addition, the molar ratio of the tetraalkoxysilane condensate (2) and glycerin in this reaction was 1: 0.1, and the remaining silica ratio obtained by baking at 900 ° C. was 42% by weight. .

・ Modified silicate (2)
To 100 parts by weight of the tetraalkoxysilane condensate (2), 1.84 parts by weight of glycerin and 1 part by weight of dibutyltin dilaurate are added, mixed, and then subjected to a demethanol reaction at 75 ° C. for 8 hours to obtain a modified silicate (2) Was synthesized. In addition, the molar ratio of the tetraalkoxysilane condensate (2) and glycerin in this reaction was 1: 0.2, and the residual silica ratio obtained by baking at 900 ° C. was 42% by weight. .

・ Modified silicate (3)
To 100 parts by weight of the tetraalkoxysilane condensate (1), 52 parts by weight of isobutyl alcohol and 0.03 part by weight of dibutyltin dilaurate as a catalyst were added, mixed and then subjected to a demethanol reaction at 75 ° C. for 8 hours. An alkoxysilane condensate (3) was synthesized. The transesterification rate of this tetraalkoxysilane condensate (3) (ratio of isobutoxy groups to all alkoxyl groups) was 38 equivalent%, and the residual silica ratio obtained by firing at 900 ° C. was 43% by weight.

  Next, 0.92 parts by weight of glycerin and 0.5 parts by weight of dibutyltin dilaurate are added to 100 parts by weight of the tetraalkoxysilane condensate (3) obtained by the above method. A time-demethanol reaction was performed to synthesize modified silicate (3). In addition, the molar ratio of the tetraalkoxysilane condensate (3) and glycerin in this reaction was 1: 0.1, and the remaining silica ratio obtained by firing at 900 ° C. was 42% by weight. .

(Manufacture of main agent)
・ Main agent (1)
Non-water-dispersed acrylic polyol (hydroxyl value 50KOHmg / g, weight average molecular weight 80000, glass transition temperature 35 ° C, solid content 50% by weight, medium: mineral spirit, aliphatic hydrocarbon 70% by weight) is oxidized against 200 parts by weight. The main agent (1) was produced by uniformly mixing and stirring 86 parts by weight of titanium, 18 parts by weight of mineral spirits, and 1 part by weight of a silicone-based antifoaming agent by a conventional method.

・ Main agent (2)
Non-water-dispersed acrylic polyol (hydroxyl value 50KOHmg / g, weight average molecular weight 80000, glass transition temperature 35 ° C, solid content 50% by weight, medium: mineral spirit, aliphatic hydrocarbon 70% by weight) is oxidized against 200 parts by weight. 86 parts by weight of titanium, 2 parts by weight of bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (molecular weight 508, pKb5.5), 18 parts by weight of mineral spirit, 1 part by weight of silicone-based antifoaming agent Was mixed and stirred uniformly by a conventional method to produce the main agent (2).

(Manufacture of curing agent)
・ Curing agent (1)
40 parts by weight of Solvesso 100 (manufactured by Exxon Chemical) and 20 parts by weight of the modified silicate compound (1) are uniformly added to 40 parts by weight of polyisocyanate containing isocyanurate structure (non-volatile content: 100% by weight, NCO content: 21% by weight). The curing agent (1) was produced by mixing.

・ Curing agent (2)
40 parts by weight of Solvesso 100 (manufactured by Exxon Chemical) and 20 parts by weight of the modified silicate compound (2) are uniformly added to 40 parts by weight of the polyisocyanate containing isocyanurate structure (non-volatile content: 100% by weight, NCO content: 21% by weight). The curing agent (2) was produced by mixing.

・ Curing agent (3)
For 40 parts by weight of polyisocyanate containing isocyanurate structure (non-volatile content: 100% by weight, NCO content: 21% by weight), 40 parts by weight of Solvesso 100 (manufactured by Exxon Chemical) and 20 parts by weight of the modified silicate compound (3) The curing agent (3) was produced by mixing.

・ Curing agent (4)
40 parts by weight of Solvesso 100 (manufactured by Exxon Chemical Co.) and 20 parts by weight of tetraalkoxysilane condensate (2) with respect to 40 parts by weight of polyisocyanate containing isocyanurate structure (non-volatile content: 100% by weight, NCO content: 21% by weight) The curing agent (4) was produced by mixing uniformly.

・ Curing agent (5)
10 parts by weight of Solvesso 100 (manufactured by Exxon Chemical) and 50 parts by weight of the tetraalkoxysilane condensate (2) with respect to 40 parts by weight of polyisocyanate containing isocyanurate structure (non-volatile content: 100% by weight, NCO content: 21% by weight) The curing agent (5) was produced by mixing uniformly.

(Manufacture of paint)
・ Coating material A
The base material (1) and the curing agent (1) produced by the above method were uniformly mixed at a weight ratio of 86:14 to obtain a top coating material A. The mixing ratio of the modified silicate compound in the top coating material A is 4.2 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the resin solid content.

・ Coating material B
The base material (1) and the curing agent (2) produced by the above method were uniformly mixed at a weight ratio of 86:14 to obtain a top coating material B. The mixing ratio of the modified silicate compound in the top coating material B is 4.2 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the resin solid content.

・ Coating material C
The base material (1) and the curing agent (3) produced by the above method were uniformly mixed at a weight ratio of 86:14 to obtain a top coating material C. The mixing ratio of the modified silicate compound in the top coating material C is 4.2 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the resin solid content.

・ Coating material D
The base material (2) and the curing agent (1) produced by the above method were uniformly mixed at a weight ratio of 86:14 to obtain a top coating material D. The mixing ratio of the modified silicate compound in the top coating material D is 4.2 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the resin solid content.

・ Coating material E
The base material E was obtained by uniformly mixing the main agent (1) and the curing agent (4) produced by the above method in a weight ratio of 86:14. The mixing ratio of the modified silicate compound in the top coating material E is 4.3 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the resin solid content.

・ Coating material F
The base material (1) and the curing agent (5) produced by the above method were uniformly mixed at a weight ratio of 86:14 to obtain a top coating material F. The mixing ratio of the modified silicate compound in the top coating material F is 10.7 parts by weight in terms of SiO _{2 with} respect to 100 parts by weight of the resin solid content.

(Stain prevention test)
Two ceramic siding boards measuring 300 mm in length, 140 mm in width, and 12 mm in thickness were mounted on a slate plate having a length of 300 mm, a width of 300 mm, and a thickness of 3 mm, with an interval of 20 mm. The joint between the boards was filled with a polyurethane sealant (containing 10% by weight of dioctyl phthalate) with a spatula and cured for 7 days. Next, each top coating material was spray-coated at a coating amount of 0.3 kg / m ² and cured for 14 days. The coating, curing, and the like were all performed under standard conditions (temperature 23 ° C., relative humidity 50%).

  The test plate obtained by the above method was left for 7 days in an 80 ° C. environment and then taken out and allowed to cool in a standard state. Next, after placing the test body horizontally and spraying No. 8 black silica sand, the test plate was set up vertically to allow the silica sand to fall naturally. At this time, the degree of adhered No. 8 black silica sand (the ratio of the adhered area to the sprinkled area) was visually confirmed. As a result, the amount of black silica sand adhered was small, but the specimen of the top coating material D was the best, followed by the top coating materials A, B, C and F, and then the top coating material E.

(Crack prevention test)
In addition, the test plate obtained by the above method was subjected to a total of 10 cycles of hot and cold repeated tests in which water immersion (23 ° C.) 18 hours → −20 ° C. 3 hours → 80 ° C. 3 hours was 1 cycle, Appearance was confirmed. As a result, no abnormality was observed in the specimens coated with the top coating materials A to E, but slight cracking was observed in the specimen of the top coating material F.

Claims (1)

In a paint finishing method in which the surface of a plasticizer-containing material is coated with a top coat material,
The plasticizer-containing material is an architectural sealant;
As the coating material,
With respect to 100 parts by weight of the solid content of the coating resin having a glass transition temperature of -20 to 60 ° C., 0.05 to 20 parts by weight of a silicate compound as a stain resistance improving component in terms of SiO _{2 is} contained as the silicate compound. , tetraalkoxysilane condensates (a) is seen containing a modified silicate compound modified with polyhydric alcohol molecule weight have 3 or more hydroxyl groups in one molecule is less than 500 (b),
A coating finishing method comprising using a top coating material containing an amine compound in addition to the silicate compound .