JPH09137119A - Non-staining paint composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a non-staining paint compsn. which, from immediately after the formation of a coating, is hydrophilic in its surface and exhibits a soil release effect and can yield a coating having excellent weather resistance and other properties by incorporating particular polyol, alkoxysilane compd. and alkyl silicate and a polyisocyanate in predetermined respective amts. SOLUTION: A polyol having a wt.-average mol.wt. of 5,000 to 80,000 and a hydroxyl value of 20 to 150KOHmg/g (e.g. an acrylic polyol) in an amt. of 100 pts.wt. on a solid basis, an alkoxysilane compd. having a number of repeating units of 2 to 40, contg. an alkylene oxide chain, having a wt.-average mol.wt. of 150 to 3,500 (e.g. a compd. prepd. from polyethylene glycol and an NCO-contg. silane) in an amt. of 0.1 to 20 pts.wt. on a solid basis, an alkyl silicate (condensate) represented by the formula (wherein R represents a 1-10C alkyl) in an amt. of 1 to 40 pts.wt. on a solid basis, and a polyisocyanate (e.g. a trimer of hexamethylene diisocyanate) in a ratio of OH in the polyol to NCO of 0.6 to 1.5 are mixed together to prepare a non-staining paint compsn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contaminating paint composition used for surface finishing of various materials such as metal, glass, porcelain tile, concrete, siding board, extruded board and plastic.

[0002]

2. Description of the Related Art Conventionally, paint finishing has been performed to protect the frame of a building, a civil engineering structure, or the like, to provide designability, and to improve the appearance. In particular, with the advent of highly durable paints such as fluorine resin paints, acrylic silicone resin paints or acrylic urethane resin paints in recent years, great progress has been made in the protection of the body. However, these high-durability paints have resulted in the problem of contamination of the coating film surface being rather highlighted due to the excellent durability. That is, even if the surface of the coating film formed by the coating material before these highly durable coating materials is deteriorated by the ultraviolet rays of sunlight and the adhesion of contaminants is caused, it is peeled off together with the deteriorated portion of the coating film surface. However, since the durability of the coating film was improved, the mechanism of deterioration and peeling of the coating film surface could not function. Especially recently, in the city center and suburbs,
If oily pollutants are suspended in the air due to exhaust gas from automobiles, etc., and if these oily pollutants adhere to the surface of the coating film made of highly durable paint, it will cause significant soot. Occurrence of streaky or streak-like pollution, and the paint finish applied to improve the cityscape did not make sense in some cases.

[0003] On the other hand, various non-contamination type paints have been published which make the surface of the coating film hydrophilic and remove the adhered oily contaminants by the action of rainwater during rainfall spreading on the coating film surface. I have. For example, Japanese Patent Application Laid-Open No. 4-37017
No. 6, in the coating by adding a segmented polymer containing a hydrophilic segment such as a polyalkylene oxide segment and a hydrophobic segment such as a polysiloxane to the coating film surface simultaneously imparts hydrophobicity and hydrophilicity, Some are expected to suppress the attachment of pollutants and to provide a cleaning effect by rainfall. The hydrophilicity of the coating film surface is represented by, for example, the contact angle of the coating film surface to water as shown in FIG. 1, and the smaller this value is, the more hydrophilic the coating film is. Due to the hydrophilicity of the surface of the coating film, water derived from precipitation or the like permeates and flows into the interface between the coating film and the contaminant, and the effect of washing away the contaminant with the water (soil release effect) is obtained.

The mechanism for making the surface of the coating film hydrophilic is described in "Surface" Vol. 32 No. 6 (199
4) Introduced by the inventor himself of the above-mentioned Japanese Patent Application Laid-Open No. 4-370176 on page 55 to 61 as "Surface characteristics of silicone polymer as coating material".
It is described as follows that the conversion of hydrophilicity / hydrophobicity of the coating film surface is caused by a morphological change. A silicone macromonomer having a structure in which an acyl urethane bond which is a hydrophilic segment and a siloxane bond which is a hydrophobic segment are adjacent to each other is synthesized, and the copolymer (containing 20 wt% of the silicone macromonomer) on the film surface is synthesized.
As a result of examining the relationship between the orientation state of each of the hydrophilic / hydrophobic segments and the atmosphere on the surface of the coating film, the initial contact angle of water on the surface of the copolymer film was 90 °.
After the coating film was soaked in water at room temperature for 2 weeks, it was 74 °, which was lower than that of the system containing no silicone, and the surface became hydrophilic. Then, when left to stand for 1 week and dried, the contact angle with water recovered and the film became hydrophobic. Showed a tendency to become. In the acrylic copolymer film containing no silicone macromonomer as a comparative sample,
Such a phenomenon is not shown and it can be presumed that it is due to the structure of the silicone macromonomer. E of the surface after drying (DRY) and the surface immediately after immersion in water for 2 weeks (WET)
As a result of the analysis in the depth direction by SCA, elemental analysis was performed by selecting N as the element showing the concentration on the surface of the hydrophilic segment and Si as the element showing the concentration on the surface of the hydrophobic segment. Considering the state of the coating surface layer based on the concentration ratio, if the coating surface environment is hydrophobic, the silicone segment is concentrated on the surface, and conversely, if it becomes hydrophilic, the acyl urethane segment is concentrated, causing a morphological change. It was speculated that

This phenomenon is caused by the localization of the hydrophobic segment having a low surface free energy to the surface of the coating film. That is, when water is present due to rainfall or the like, it shows a morphological change in which it migrates to the surface of the coating film and is localized. However, as described in the above literature, the morphological change of the coating film surface from hydrophobicity to hydrophilicity is not actually carried out immediately, and rainfall on the coating film surface for a long time to some extent It can gradually become hydrophilic when the contact time with water is long.

Further, when there is no rainfall for a certain period of time, that is, when fine weather continues, the surface of the coating film goes back to be hydrophobic, so that the surface of the coating film becomes hydrophilic. It is necessary to contact with water again for a long time. As one of the measures to prevent this, there is a method of setting the glass transition point of the coating film forming polymer to be low in order to easily cause the morphology change. This results in the physical attachment of dust that cannot be washed off, which in turn leads to permanent contamination.

[0007] On the other hand, in Japanese Patent Application No. 6-506632 (International Publication WO94 / 06870), an organosilicate is mixed in a coating material, and the reaction of both improves the hydrophilicity and hardness of the coating film. The designed method is shown. In general, an organosilicate undergoes a reaction as shown in [Chemical formula 2], and a silanol group or a siloxane bond generated by such a reaction becomes a factor for the hydrophilicity of the coating film surface. Therefore, in order to make the surface of the coating film hydrophilic and improve the hardness, the hydrolysis reaction due to the presence of the acid catalyst in the first step is rate-determining. For these reasons, the above coating requires surface treatment with an acid or the like in order to promote the reaction of the organosilicate. Considering the actual painting on the building outer wall, the reaction is thought to proceed due to acid rain, etc., but as described above, a considerable amount of time is required after the coating is formed in order to obtain the hydrophilic surface necessary for fully exhibiting the soil release effect. Requires a long time.

[0008]

Embedded image

Further, Japanese Unexamined Patent Publication No. 6-145453 discloses a method in which an acrylic silicate resin is mixed with an organosilicate to obtain a hydrophilic coating film. Acrylic silicone resin has the same curing mechanism because the functional group contributing to its curing is a hydrolyzable silyl group similar to organosilicate, and therefore, usually an acid or base is cured for coating film formation. It is mixed as a catalyst. Since these catalysts cause the reaction of the organosilicate to proceed at the same time, the surface of the coating film is hydrophilized relatively quickly.
However, as described in JP-A-6-145453, there are many cross-linking sites as compared with an acrylic silicone resin that originally contains a hydrolyzable silyl group in a part of the molecule to adjust the degree of cross-linking of a coating film. When a large amount of organosilicate is blended, the crosslink density of the coating film becomes too large, the coating film becomes brittle, and a large number of siloxane bonds with high ionic bondability and high acid or base hydrolyzability are introduced. This leads to a decrease in the chemical resistance of the film, which results in a decrease in the weather resistance of the coating film. Therefore, in order to improve the hydrophilicity of the coating film, a large amount of the organosilicate is required, but there is a contradiction that when the amount is too large, the physical properties of the coating film are impaired.

[0010]

Among the coating films formed by the conventional non-staining type paints, those which require a long period of time to make the surface hydrophilic are those which have a low non-staining property in the early stage after the formation of the coating film. From the low level, rain streaks and the like are generated in a very short time after the completion of the painting work. Originally, the effect of not contaminating non-contamination type paint is to make the effect, and the user who uses it and the client who requests the painting work are expecting the effect. Therefore, even in the early stage after the formation of the coating film, the occurrence of stains, even if temporarily, betrays the expectations of these users and owners, and gives anxiety to the long-term non-staining effect. It will be. Furthermore, conventional non-polluting paints are mainly used for the purpose of flowing down pollutants due to rainfall, so that they are poor in the resistance to soaking of stains once adhered, and when there is no rainfall for a long time, oily stains are present in the coating film. It has been found that it has penetrated and that dirt can no longer flow down due to rainfall.

The problem to be solved by the present invention is that the coating film does not become hydrophilic for the first time due to the action that occurs after the coating film is formed, such as rainfall, but the surface exhibits hydrophilicity immediately after the coating film is formed. It has an oil-releasing effect to wash away contaminants, and due to a specific cross-linking structure, it is strong and does not become brittle, has excellent resistance to seeping into oily stains, and has good weather resistance and other physical properties of the coating film. It is to obtain a non-contaminating paint composition which provides a stain-type coating film.

[0012]

The present invention relates to the following non-contaminating paint composition. That is, (A) a weight average molecular weight of 5,000 to 80,000 and a hydroxyl value of 20 to 150.
A (KOHmg / g) polyol contains an alkylene oxide chain having a repeating unit (B) of 2 to 40 and a weight average molecular weight of 150 to 100 parts by weight of a solid content.
3500 alkoxysilane compounds have a solid content of 0.1
~ 20 parts by weight, (C) general formula

Embedded image 1 to 40 parts by weight of a solid content of at least one of an alkyl silicate represented by or a condensate thereof, and (D) polyisocyanate is 0.6 at an OH / NCO ratio based on the hydroxyl group of the polyol (A). The present invention relates to a non-staining coating composition, characterized in that it is contained in an amount of 1.5.

The present invention also provides the above-mentioned (A) as a main agent.
At least one of the above-mentioned component containing a polyol, the above-mentioned (B) alkoxysilane compound as a curing agent, (C) an alkyl silicate or a condensate thereof,
(D) consists of 2 packs of a polyisocyanate-containing component, a main agent and a curing agent.
(B) is 0.1 to 20 parts by weight, and (C) is 1 to 40 parts by weight, based on 100 parts by weight of the solid content of
And (D) is OH / N with respect to the hydroxyl group of the component (A).
The present invention relates to a non-contaminating coating composition in which a main agent and a curing agent are mixed so that the CO ratio becomes 0.6 to 1.5.

In the present invention, it is preferable to use an acrylic polyol as the polyol (A),
(B) is preferably an alkoxysilane having an ethylene oxide chain as the alkylene oxide chain and a hydroxyl group at one end, and (C) is preferably an alkyl silicate using at least one of tetramethyl silicate and tetraethyl silicate.

The polyisocyanate used in the present invention is preferably dissolved in a solvent containing a ketone solvent in an amount of 5% by weight or more. It may be dissolved only in a ketone solvent.

Further, it is also preferable that the polyol component (A) contains a color pigment (E), and an extender pigment can be blended to form a matte coating film.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on its embodiments. The polyol (A) means an oligomer polyol generally used in the technical field of polyurethane, and is a non-staining coating film formed from a non-staining coating composition by mixing and reacting with polyisocyanate which is a curing agent. In the above, it becomes the main element for forming a coating film.

Examples of such polyols include polyether polyols, polyester polyols and acrylic polyols. As the polyether polyols, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin,
Obtained by adding one or more of propylene oxide, ethylene oxide, butylene oxide, styrene oxide and the like to one or more of polyhydric alcohols such as trimethylolpropane, pentaerythritol, glucose, sorbitol and sucrose. And polyoxytetramethylene polyols obtained by adding tetrahydrofuran to the polyhydric alcohol by ring-opening polymerization.

The polyester polyols include one or more of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane, pentaerythritol and other low molecular weight polyhydric alcohols. With glutaric acid, adipic acid, pimelic acid, speric acid, sebacic acid, terephthalic acid, isophthalic acid, dimer acid, hydrogenated dimer acid or other low molecular weight dicarboxylic acid or oligomeric acid, or two or more of them. Examples thereof include polyols such as a ring-opening polymer of a cyclic ester such as a combination, propiolactone, caprolactone, and valerolactone.

In the acrylic copolymer, β-hydroxyethyl acrylate, β-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, β-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, β-acrylate Hydroxyalkyl esters of acrylic acid such as hydroxypentyl or similar hydroxyalkyl esters of methacrylic acid, acrylic acid monoesters of polyhydric alcohols such as glycerin and trimethylolpropane, or methacrylic acid monoesters similar to these, N-methylolacrylamide Alternatively, an acrylic polyol having two or more hydroxyl groups in one molecule, which is a copolymerizable monomer of a monoethylenically unsaturated monomer having a hydroxyl group such as N-methylolmethacrylamide, can be used.

Besides, polymer polyols, urea-dispersed polyols, carbonate polyols, etc. in which monomers such as phenol resin polyol, epoxy polyol, polybutadiene polyol, polyisoprene polyol, polyester-polyether polyol, acryl and styrene are vinyl-added or dispersed. Can be used as the polyol of the present invention. Particularly, considering the weather resistance of the non-staining coating film formed from the composition of the present invention, acrylic polyol is preferable.

The weight average molecular weight of the polyol used in the present invention is 5,000 to 80,000, preferably 20,000 to 60,000. Molecular weight 5000
When it is smaller, the curability and durability of the coating film are inferior, and when it is larger than 80,000, the finish property of the coating film is not sufficient.

Furthermore, the hydroxyl value of these polyols is 2
0 to 150 (KOHmg / g), preferably 30 to 10
It is 0 (KOHmg / g). When the hydroxyl value is less than 20, the durability and stain resistance of the coating film are insufficient, and when it exceeds 150, the durability and flexibility of the coating film are insufficient.

The glass transition point of these polyols is -10 ° C to 150 ° C, preferably 10 ° C to 100 ° C. When the temperature is lower than -10 ° C, the soil removal property and the soil recovery property are poor. When the temperature is higher than 150 ° C, flexibility and durability are poor.

Next, the (B) alkylene oxide chain-containing alkoxysilane compound (hereinafter referred to as the (B) component) used in the present invention is a repeating unit of an alkylene oxide group and at least one or more alkoxysilyl groups. Is a compound having In the alkylene oxide group repeating unit of the component (B), the alkylene portion has 2 to 4 carbon atoms, and the repeating number is 2 to 40, preferably 2 to 20.

The component (B) may have an alkoxysilyl group at both ends, an alkoxysilyl group at one end and another functional group at the other end. Examples of such a functional group that can be present at one end include, for example,
Examples include a vinyl group, a hydroxyl group, an epoxy group, an amino group, an isocyanate group, and a mercapto group. The functional group may be bonded to an alkoxysilyl group via a urethane bond, a urea bond, a siloxane bond, an amide bond, or the like. As the component (B), for example, a compound synthesized by reacting a polyalkylene oxide chain-containing compound with an alkoxysilyl group-containing compound (hereinafter referred to as a coupling agent) can be used.

The polyalkylene oxide chain-containing compound preferably has a molecular weight of 150 to 3500, and 200 to
1500 is more preferred. When the molecular weight is less than 150, the hydrophilicity of the finally obtained cured coating film is poor, the effect of cleaning contaminants due to rainfall cannot be obtained, and the molecular weight is 3500.
If it exceeds, the water resistance and hardness of the coating film will decrease. As such a polyalkylene oxide chain-containing compound,
Polyethylene glycol, polyethylene-propylene glycol, polyethylene-tetramethylene glycol,
Examples include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyoxyethylene diglycolic acid, polyethylene glycol vinyl ether, polyethylene glycol divinyl ether, polyethylene glycol allyl ether, and polyethylene glycol diallyl ether. The polyalkylene oxide chain-containing compound can be selected from one kind or a combination of two or more kinds.

On the other hand, the coupling agent is, for example, a compound having at least one or more alkoxysilyl groups and other substituents in one molecule. Specific examples of the coupling agent include β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, and N-β. (Aminoethyl) γ-aminopropylmethyldimethoxysilane, N-
β (aminoethyl) γ-aminopropylmethyltrimethoxysilane, γ-aminopropyltrimethoxysilane,
γ-aminopropyltriethoxysilane, isocyanate-functional silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, and the like.

The synthesis of the component (B) is not particularly limited, but the polyalkylene oxide chain-containing compound and the coupling agent are prepared separately, and for example, for each compound having a polymerizable double bond, a radical polymerization initiator is used. In addition to copolymerization by using, it can be synthesized by a known method such as addition reaction of amino group / epoxy group, isocyanate group / hydroxyl group or isocyanate group / amino group. Further, it can also be synthesized by a method in which ethylene oxide is ring-opened and added to an alkoxysilyl compound having an active hydrogen group such as a primary or secondary amino group.

When copolymerization is carried out using a radical polymerization initiator, at least one kind of polyalkylene oxide chain-containing compound having a polymerizable double bond and at least one kind of coupling agent are suitable as non-reactive. It can be obtained by reacting in a different solvent. In this case, examples of the radical polymerization initiator used include benzoyl peroxide, dichlorobenzoyl peroxide, 2,5-di (peroxybenzoate) hexyne-3,1,3-bis (t-butylperoxy). Isopropyl) benzene, t
Perester compounds such as -butyl perbenzoate,
Examples include azo compounds such as azobisisobutyronitrile and dimethylazobutyrate, and organic peroxides.

As the polyalkylene oxide chain-containing compound having a polymerizable double bond, for example, polyethylene glycol vinyl ether can be used, and the coupling agent is γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyl. Methyldiethoxysilane, γ-methacryloxypropyltriethoxysilane and the like can be used alone or in combination of two or more.

In the addition reaction of amino group / epoxy group, the reaction ratio is not limited, but it is preferable to carry out the reaction in the range of 0.1 to 2 in the equivalent ratio of amino group / epoxy group. When the reaction ratio of amino group / epoxy group is less than 0.1 in terms of equivalent ratio, the crosslinking reaction with the alkoxysilyl group-containing acrylic resin or the crosslinking reaction of the polyalkylene oxide chain-containing coupling agent itself is insufficient and the curing Water resistance and chemical resistance of the product are reduced. If the reaction ratio exceeds 2 at each equivalent ratio, the hydrophilicity of the coating film surface of the cured product and the weather resistance decrease.

In the case of synthesizing by an isocyanate / polyol addition reaction, for example, the polyalkylene oxide chain-containing compound is a compound having a hydroxyl group at the terminal such as polyethylene glycol, and the coupling agent is an isocyanate-containing coupling agent or the like. Compounds having groups are mixed and synthesized. In this synthesis method, it is also possible to use a reaction catalyst such as dibutyltin dilaurate, dibutyltin dimaleate or dioctyltin dimaleate.

In the addition reaction of isocyanate group / hydroxyl group, the reaction ratio is not limited, but the equivalent ratio is 0.1.
It is preferable to react in the range of 2 to 2. The reaction ratio of isocyanate group / hydroxyl group is 0.1 at each equivalent ratio.
In the following cases, the cross-linking reaction with the alkoxysilyl group-containing acrylic resin or the cross-linking reaction of the polyalkylene oxide chain-containing coupling agent itself is not sufficient, and the water resistance and chemical resistance of the cured product deteriorate. If the reaction ratio exceeds 2 at each equivalent ratio, the hydrophilicity of the coating film surface of the cured product and the weather resistance decrease.

Among these components (B), the one having an alkylene oxide chain of ethylene oxide chain and a hydroxyl group at one end is most preferred because it has a high anti-staining effect of the present invention, that is, a high anti-staining property and a resistance to soaking. preferable.

The mixing ratio of the component (B) is 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the resin solid content of the component (A). If the amount is less than 0.1 part by weight, the hydrophilicity of the obtained cured product is insufficient, and 2
If the amount exceeds 0 parts by weight, the compatibility with the resin and the water resistance of the cured product will deteriorate.

Next, the alkyl silicate represented by the general formula [Chemical Formula 1] (C) used in the present invention and a condensate of these (hereinafter referred to as the component (C)) is, for example, tetramethyl silicate or tetraethyl. Silicate, tetra-n-
One or more selected from propyl silicate and tetra-i-propyl silicate, and the condensate includes one or more selected from those obtained by condensing the above tetraalkyl silicate under hydrolysis conditions. To be In particular, use of at least one of tetramethyl silicate and tetraethyl silicate, or a condensation product thereof is preferable from the viewpoint of the balance between flexibility and denseness of the coating film formed. The condensation degree of the condensate is preferably from 2 to 20, and when the condensation degree is 20 or more, the viscosity of the condensate increases, the handling becomes inconvenient, the compatibility with the polyol deteriorates, and the paint becomes cloudy. Become.

Further, the mixing ratio of the component (C) is 1 to 40 in terms of solid content with respect to 100 parts by weight of the resin solid content of the component (A).
Weight parts, preferably 2 to 20 parts by weight are suitable. If it is less than 1 part by weight, the surface hardness of the cured coating film is not sufficient, causing physical adhesion of contaminants and causing permanent contamination. If it exceeds 40 parts by weight, compatibility with the resin and cured product are obtained. This is because there is a problem in that the appearance is deteriorated and cracks occur.

In the present invention, (D) polyisocyanate (hereinafter referred to as "D" component) is blended and cross-linked and cured to form a non-staining coating film. As such a curing agent, toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (pure MDI), polymeric MDI, xylylene diisocyanate (XD) is used.
I), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HMDI), hydrogenated X
Difunctionalized diisocyanate monomers such as DI and hydrogenated MDI are allophanated, buretized, dimerized (uretidione), trimerized (isocyanurate), adduct, carbodiimidized, etc. Isocyanates and mixtures thereof can be used. Further, these polyisocyanates can also be used in the form of blocked isocyanates using well-known blocking agents such as alcohols, phenols, ε-caprolactam, oximes and active methylene compounds. These polyisocyanate and blocked isocyanate compounds are used as a solution in a solvent containing no active hydrogen.

The polyisocyanate and the component (A) are mixed in a ratio such that the OH / NCO equivalent ratio is 0.6 to 1.5, preferably 0.8 to 1.2. At this time, if the OH / NCO ratio is less than 0.6, the coating film has poor curability, stain recovery, and durability, and if it is greater than 1.5,
Poor durability, curability and stain removability.

These components (A), (B), (C), and (D) can form a non-staining coating film by mixing the components at the time of use, but usually ( A),
A mixture of the components (B) and (C) and two components (D)
A mixture of pack, (A) and (B) and (C),
2 packs of the mixture of the components (D), or (B),
A mixture of the components (C) and (D) and the component (A) 2
It is stored and distributed in either form of a pack, and both are mixed and used at a ratio such that an optimum OH / NCO ratio is obtained at the time of use. In particular, a mixture of the components (B), (C) and (D) and a two-pack type of the component (A) are preferable from the viewpoint of storage stability of the components (B) and (C). Further, in this case, as the solvent of the component (D), an organic solvent containing 5% by weight or more of a ketone solvent composed of acetone, methyl ethyl ketone, 2-pentanone, 2-hexanone, methyl-i-butyl ketone, cyclohexanone, etc., alone or in a mixture. The one using a solvent is excellent in storage stability. In particular, it is preferable to add Additive TI (manufactured by Bayer) in order to prevent the isocyanate group from reacting and being inactivated by the water entering the storage container.

When the above-mentioned blocked isocyanate compound is used, the components (A) to (D) can be contained in one pack, and when this one-pack type coating material is used, it may be heated after coating. By dissociating the blocking agent, NCO is generated and the coating film can be crosslinked and cured. In this case, it is preferable to add a catalyst which is usually used for promoting the reaction between the isocyanate group and the hydroxyl group.

In the composition of the present invention, (A), (B),
In addition to the transparent (clear) coating film of the components (C) and (D), a color pigment may be blended to form a colored (enamel) coating film. Examples of such a color pigment include titanium oxide, zinc oxide, Carbon black, ferric oxide,
Inorganic pigments such as lead chromate (molybdate orange) yellow lead, yellow iron oxide, ocher, ultramarine, cobalt green, azo, naphthol, pyrazolone, anthraquinone, perylene, quinacridone, disazo, isoindo Organic pigments such as linone type, benzimidazole type, phthalocyanine type and quinophthalone type can be used.

Further, an extender pigment such as heavy calcium carbonate, clay, kaolin, talc, precipitated barium sulfate, barium carbonate, white carbon or diatomaceous earth can be used in combination. In particular, when forming a matte coating, it is optimal to use white carbon or diatomaceous earth, which has the least loss of the non-contaminating effect on the coating surface.
When these inorganic substances are added to the paint, it is preferable to treat the powder surface with a coupling agent or to add the coupling agent to the paint.

The composition of the present invention may contain various additives which can be usually added to the coating composition to such an extent that the effect of the present invention is not affected. Examples of such additives include plasticizers, preservatives, fungicides, anti-algal agents, defoamers, leveling agents, pigment dispersants, anti-settling agents, anti-sag agents, matting agents, ultraviolet absorbers and the like. can give.

[0046]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention. The materials used in this example and their characteristics are summarized in Table 1. (Synthesis example 1) Polyalkylene oxide chain-containing coupling agent 1 Synthesis example Polyethylene glycol 200 (average molecular weight 200; Wako Pure Chemical Industries, Ltd.) was placed in a reaction tank equipped with a heating device, a stirrer, a reflux device, a dehydrator and a thermometer. 20 parts by weight) and 54.3 parts by weight of Y-9030 (manufactured by Nippon Unicar Co., Ltd.), which is an isocyanate-containing silane, and 0.05 parts by weight of dibutyltin dilaurate are charged at 50 ° C. The reaction was carried out for 8 hours to obtain a pale yellow polyethylene oxide chain-containing coupling agent (1). The weight average molecular weight of this polyethylene oxide chain-containing coupling agent was 800 as measured by gel permeation chromatography (hereinafter referred to as GPC) in terms of polystyrene.

(Synthesis Example 2) Polyalkylene oxide chain-containing coupling agent 2 Synthesis Example A reaction vessel equipped with a heating device, a stirrer, a reflux device, a dehydrator, and a thermometer was used, and Epolite 40E, which was polyethylene glycol glycidyl ether (average). Molecular weight 170: 100 parts by weight of Kyoeisha Chemical Co., Ltd., and amino group-containing silane A-1100 (manufactured by Nippon Unicar Co., Ltd.) 63.
0 parts by weight and reacted at 50 ° C. for 8 hours to obtain a pale yellow polyethylene oxide chain-containing coupling agent (2). The weight average molecular weight of the polyethylene oxide chain-containing coupling agent was 980 as measured by GPC in terms of polystyrene.

(Example 1) 150 mm × 70 mm × 0.
SK # 1000 primer (epoxy resin-based primer, SK Kaken Co., Ltd.) on 7 sheets of 8 mm aluminum plate
(Manufactured by the same company) was spray-coated so that the dry film thickness was about 30 μm, and dried at a temperature of 20 ° C. and a humidity of 65% for 8 hours. Next, using the raw materials shown in Table 1, 42 parts by weight of titanium oxide was uniformly kneaded with 100 parts by weight of the solid content of acrylic polyol 1 as shown in the compounding ratio of Table 2, and polyethylene oxide was added thereto. 3.0 parts by weight of the chain-containing coupling agent 1 and 10 parts by weight of tetramethyl silicate 1 were blended to prepare a main component of a white paint. A non-contaminating coating composition containing 7.5 parts by weight of a hexamethylene diisocyanate trimer (isocyanurate type) as a curing agent so that the OH / NCO ratio is 1.0 with respect to the base material, The surface of the SK # 1000 primer of No. 3 was spray-coated so that the dry film thickness was 25 μm to obtain a test body.

[Test Method] (1) Evaluation of Appearance after Curing of Coating Film The test body was aged at a temperature of 20 ° C. and a humidity of 65% for 7 days, and then subjected to JIS.
K5400 7.1 The appearance of the coating film was evaluated according to the appearance test of the coating film.

(2) Water resistance evaluation A test piece was aged at a temperature of 20 ° C. and a humidity of 65% for 7 days, and then subjected to JIS.
K5400 According to 8.19 water resistance test, after soaking in water at 20 ℃ for 1 week, shake off water, temperature 20 ℃, humidity 65%
The appearance of the coating film after drying for 2 hours was evaluated.

(3) Acid resistance evaluation A test piece was aged at a temperature of 20 ° C. and a humidity of 65% for 7 days, and then subjected to JIS.
K5400 According to 8.22 acid resistance test, after immersion for 1 week in a 5wt% sulfuric acid aqueous solution at 20 ℃, wash the coating surface with water and
The appearance of the coating film after drying for 2 hours was evaluated.

(4) Alkali resistance evaluation A test piece was aged at a temperature of 20 ° C. and a humidity of 65% for 7 days, and then subjected to JIS
K5400 According to 8.21 alkali resistance test, 5% by weight at 20 ℃
After dipping in an aqueous solution of sodium hydroxide for 1 week, the surface of the coating film was washed with water and dried at 20 ° C. for 2 hours, and the appearance of the coating film was evaluated.

(5) Measurement of contact angle with water After the test piece was manufactured, the temperature was 20 ° C. and the humidity was 65%.
0.2 cc of deionized water was dropped on the surface of the coating film after drying for 4 hours (1 day), 72 hours (3 days) and 14 days, and immediately after the dropping at 20 ° C., the contact angle after 1 minute Was measured by a Kyowa Interface Science Co., Ltd. CA-A type contact angle measuring device.

(6) Contamination resistance After the test specimen was cured at a temperature of 20 ° C. and a humidity of 65% for 7 days,
Outdoor exposure was performed in Ibaraki City, Osaka Prefecture, with a 45-degree slope facing south, and the brightness difference (ΔL value) between the initial and six months was measured using a TC-1800 color difference meter manufactured by Tokyo Denshoku Co., Ltd. Colored.

(7) Resistance to soak of dirt The test piece was aged at a temperature of 20 ° C. and a humidity of 65% for 7 days, and then subjected to JIS.
K5400 8.10 According to the stain resistance test, 15% by weight on the coating surface
Carbon black water dispersion paste liquid of 20m in diameter
m, and the height was 5 mm, and the mixture was left in a thermostatic chamber at 50 ° C. for 2 hours. Then, it was washed in running water and the degree of contamination on the surface of the coating film was visually evaluated.

[Evaluation Results] The evaluation results are summarized in [Table 3]. The cured coating film according to Example 1 of the present invention was evaluated for appearance, water resistance, acid resistance and alkali resistance. No abnormalities were observed, and the coating film was in a good condition. The contact angle to water was 68 ° immediately after dropping in the measurement after 1 day, 62 ° after 1 minute, 58 ° immediately after dropping in the measurement after 3 days, 52 ° after 1 minute, and immediately after dropping in the measurement after 14 days. 58 ° and 52 ° after 1 minute, both being 1 compared to the comparative example.
The contact angle was low at the initial stage after 3 days, indicating that the initial hydrophilicity of the coating film was excellent. In addition, in the stain resistance evaluation, the ΔL value was -1.9, and good stain resistance was obtained. Furthermore, no trace was observed in the stain penetration resistance test. Therefore, it has been proved that the adhered stains are present only on the surface of the coating film, and that they are excellent non-contaminating paints that can be completely drained by rain even immediately after coating.

(Examples 2 to 6) Mixtures shown in Table 2 were prepared according to Example 1 and evaluated in the same manner as in Example 1. The results shown in Table 3 were obtained. Also, the contact angle was lower than the comparative example at the initial point of 1 day, 3 days, etc.,
Both coatings show excellent initial hydrophilicity. Also, good results were obtained in the evaluation of stain resistance and stain penetration.

Comparative Example 1 Evaluation was carried out in the same manner as in Example 1 except that polyethylene glycol 1 was used instead of polyethylene oxide chain-containing coupling agent 1 as in the formulation shown in Table 2, The results shown in Table 3 were obtained, and gloss was generated in the water resistance, acid resistance, and alkali resistance tests of the coating film. Further, the contact angle in the initial stage was not as low as that of the example, and favorable results were not obtained in the evaluation of stain resistance and stain penetration.

Comparative Example 2 Evaluation was carried out in the same manner as in Example 4 except that polyethylene glycol 1 was used instead of the polyethylene oxide chain-containing coupling agent 1 as in the formulation shown in Table 2, The results are as shown in Table 3, and the coating film after curing was glossy, and glossiness was also generated in the water resistance, acid resistance and alkali resistance test of the coating film. Further, the contact angle in the initial stage was not as low as that of the example, and favorable results were not obtained in the evaluation of stain resistance and stain penetration.

Comparative Example 3 Evaluation was carried out in the same manner as in Example 3 except that polyethylene glycol 2 was used instead of the polyethylene oxide chain-containing coupling agent 1 as in the formulation shown in Table 2, The results shown in Table 3 were obtained, and gloss was generated in the water resistance, acid resistance, and alkali resistance tests of the coating film. Further, the contact angle in the initial stage was not as low as that of the example, and favorable results were not obtained in the evaluation of stain resistance and stain penetration.

Comparative Example 4 Evaluation was carried out in the same manner as in Example 1 except that polyethylene glycol 2 was used instead of the polyethylene oxide chain-containing coupling agent 1 as in the formulation shown in Table 2, The results shown in Table 3 were obtained, and gloss was generated in the water resistance, acid resistance, and alkali resistance tests of the coating film. Further, the contact angle in the initial stage was not as low as that of the example, and favorable results were not obtained in the evaluation of stain resistance and stain penetration.

(Comparative Example 5) As shown in Table 2, acrylic polyol 2 was mixed with ethyl silicate 1, a curing agent, and
When additives were blended and evaluated in the same manner as in Example 1, the results shown in Table 3 were obtained, and the water resistance, acid resistance, and
Although there was no abnormality in alkali resistance, the contact angle in the initial stage was not reduced as much as in the Examples, and good results were not obtained in the evaluations of stain resistance and stain penetration.

The compounding ratios of the respective components in the examples and comparative examples are summarized in [Table 2].

[0064]

EFFECTS OF THE INVENTION According to the non-contaminating coating composition of the present invention, it is not the case that the coating film becomes hydrophilic for the first time due to the action that occurs after the coating film is formed, such as rainfall, but the surface becomes hydrophilic immediately after the coating film formation. In addition, since it has a high resistance to stains and has a high resistance to soaking into dirt, contaminants are washed away with rainwater due to rainfall, and since it is a urethane-based coating film with excellent weather resistance, the surface of the object to be coated can be kept beautiful without being contaminated.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a contact angle of a coating film with water.

[Explanation of symbols] a water droplet b coating film θ contact angle

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[Procedure amendment]

[Submission date] August 30, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007] On the other hand, in Japanese Patent Application No. 6-506632 (International Publication WO94 / 06870), an organosilicate is mixed in a coating material, and the reaction of both improves the hydrophilicity and hardness of the coating film. The designed method is shown. Generally, in organosilicate, the reaction as shown in [Chemical Formula 3] proceeds, and the silanol group or siloxane bond generated by such reaction becomes a factor of the hydrophilicity of the coating film surface. Therefore, in order to make the surface of the coating film hydrophilic and improve the hardness, the hydrolysis reaction due to the presence of the acid catalyst in the first step is rate-determining. For these reasons, the above coating requires surface treatment with an acid or the like in order to promote the reaction of the organosilicate. Considering the actual painting on the building outer wall, the reaction is thought to proceed due to acid rain, etc., but as described above, a considerable amount of time is required after the coating is formed in order to obtain the hydrophilic surface necessary for fully exhibiting the soil release effect. Requires a long time.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on its embodiments. Polyol (A) means a port polyol commonly used in the polyurethane art, by mixing and reacting with a polyisocyanate as a curing agent, the non-pollution coating film formed from uncontaminated coating composition In the above, it becomes the main element for forming a coating film.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Deleted

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

Component (B) synthesized by the above reaction
As both of the polyalkylene oxide chain-containing compounds
A product with a coupling agent added to the end or one end was obtained.
However, each of these may be used alone, or
It may be used as a mixture.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction contents]

(Example 1) 150 mm × 70 mm × 0.
SK # 1000 primer (epoxy resin-based primer, SK Kaken Co., Ltd.) on 7 sheets of 8 mm aluminum plate
(Manufactured by the same company) was spray-coated so that the dry film thickness was about 30 μm, and dried at a temperature of 20 ° C. and a humidity of 65% for 8 hours. Next, using the raw materials shown in Table 1, 42 parts by weight of titanium oxide was uniformly kneaded with 100 parts by weight of the solid content of acrylic polyol 1 as shown in the compounding ratio of Table 2, and polyethylene oxide was added thereto. 3.0 parts by weight of the chain-containing coupling agent 1 and 10 parts by weight of tetramethyl silicate 1 were blended to prepare a main component of a white paint. A non-contaminating coating composition containing 7.5 parts by weight of hexamethylene diisocyanate trimer (isocyanurate type) as a curing agent so that the OH / NCO ratio is 0.9 with respect to the main agent, The surface of the SK # 1000 primer of No. 3 was spray-coated so that the dry film thickness was 25 μm to obtain a test body.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0065

[Correction method] Change

[Correction contents]

[0065]

[Table 1]

Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location C09D 171: 02) (72) Inventor Takanori Nakasoya 1-25-10 Shimizu, Ibaraki-shi, Osaka SK Kaken Inside the laboratory (72) Inventor Hisashi Suzuki 1-25-10 Shimizu, Ibaraki, Osaka Prefecture

Claims (10)

[Claims] (A) a weight average molecular weight of 5,000 to 800
Alkoxysilane having a weight average molecular weight of 150 to 3500, containing 100 parts by weight of a polyol having a hydroxyl value of 20 to 150 (KOHmg / g) as a solid content and (B) a repeating unit of 2 to 40 and an alkylene oxide chain. The compound has a solid content of 0.1 to 20 parts by weight, and (C) has the general formula: 1 to 40 parts by weight of at least one of an alkyl silicate represented by or a condensate thereof, and
(D) The polyisocyanate has an OH / NCO ratio of 0.6 to 1.5 with respect to the hydroxyl group of the polyol component of (A).
A non-staining coating composition formulated to be 2. A weight-average molecular weight of (A) 5000 to 80
000, a base compound containing a polyol having a hydroxyl value of 20 to 150 (KOHmg / g), and (B) an alkoxysilane compound having a weight average molecular weight of 150 to 3500 containing an alkylene oxide chain of 2 to 40 repeating units, (C ) General formula: At least one of an alkyl silicate represented by the following formula or a condensation product thereof, and (D) a polyisocyanate:
It is composed of 2 packs of a curing agent containing, and (B) is 0.1 to 20 parts by weight and (C) is 1 to 40 parts by weight based on 100 parts by weight of the solid content in use (A). Part of the
And (D) is OH / N with respect to the hydroxyl group of the component (A).
A non-staining coating composition used by mixing a main agent and a curing agent so that the CO ratio becomes 0.6 to 1.5. 3. The non-staining coating composition according to claim 1 or 2, wherein the polyol component (A) is an acrylic polyol. 4. The non-contaminating coating composition according to claim 1 or 2, wherein a compound having an alkylene oxide chain of ethylene oxide chain and a hydroxyl group at one end is used as the alkoxysilane compound (B). 5. The non-contaminating coating composition according to claim 1 or 2, which comprises (C), wherein at least one of tetramethyl silicate and tetraethyl silicate is used as the alkyl silicate. 6. The non-staining coating composition according to claim 2, wherein the polyisocyanate is dissolved in a solvent containing a ketone solvent in an amount of 5% by weight or more. 7. The non-staining coating composition according to claim 1, further comprising a color pigment (E). 8. The non-contaminating paint composition according to claim 2, wherein the main component is a mixture of the component (A) and a coloring pigment. 9. The matte type non-staining coating composition according to claim 1, further comprising an extender pigment (F). 10. The matte type non-staining coating composition according to claim 2, wherein the main component is a mixture of the component (A) and the extender pigment (F).