JP2001163982A - Silicate-modified polyol resin composition and coating composition containing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicate compound which, when compounded into a coating composition, can give a coating film which is free from cracks and cloudiness and is excellent in stain resistance. SOLUTION: A silicate-modified polyol resin composition is obtained by reacting a polyol resin having a hydroxyl value of 5-300 and a number average mol.wt. of 500-20,000 with a silicate oligomer represented by formula I (each R is independently a 1-7C alkoxy, phenoxy, or a 2-4C alkoxy or fluoroalkoxy substituted by a 1-4C alkoxy, provided a part of the R groups may each be a 1-4C alkyl, phenyl, or hydroxyl; and n is 1-20) in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a silicate-modified polyol resin composition obtained by reacting a polyol resin with a silicate oligomer, and a coating composition containing the same.

[0002]

2. Description of the Related Art It is known that a coating film having excellent stain resistance can be obtained by incorporating a silicate compound into a coating material, and these are disclosed in, for example, WO94 / 06870 and WO96 / 262458. Has been described. However, the silicate compound used here is generally insufficient in compatibility with the binder component used in the paint, and depending on the paint system, cracks may occur in the paint film or cloudiness may be observed. . This crack is considered to be caused by a condensation reaction of the silicate compound in the coating film, while clouding is considered to be caused by the presence of silicate domains in the coating film.

On the other hand, JP-A-10-212454 discloses that an acrylic resin having an alkoxysilyl group grafted thereon can be obtained by polymerizing a (meth) acrylic monomer having an alkoxysilyl group. In this method, the amount of the alkoxysilyl group that can be introduced into the obtained acrylic resin is limited. Moreover, this method is only applicable to acrylic resins.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a silicate capable of obtaining a coating film excellent in stain resistance without causing cracks or white turbidity in the coating film when incorporated into a coating material. Is to provide a compound.

[0005]

The silicate-modified polyol resin composition of the present invention is obtained by adding a silicate oligomer represented by the following formula (I) to a polyol resin having a hydroxyl value of 5-300 and a number average molecular weight of 500-20,000. It is obtained by reacting in a solvent.

[0006]

Embedded image

(Wherein R may be the same or different and is an alkoxy group having 1 to 7 carbon atoms, a phenoxy group, an alkoxy group having 2 to 4 carbon atoms substituted with an alkoxy group having 1 to 4 carbon atoms, or A fluorinated alkoxy group,
May be an alkyl group having 1 to 4 carbon atoms, a phenyl group or a hydroxyl group. N is 1 to 20. Here, the amount of the silicate oligomer can be 0.1 to 10 times the mole of the hydroxyl group of the polyol resin. Further, the polyol resin may be an acrylic resin, a polyester resin, a fluororesin, or a melamine resin.

[0008] The coating composition of the present invention contains the silicate-modified polyol resin composition and a binder component.

The coating of the present invention is obtained from the above coating composition.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The silicate-modified polyol resin composition of the present invention is prepared by adding a polyol having a hydroxyl value of 5 to 300 and a number average molecular weight of 500 to 20,000 by the following formula (I).
Is obtained by reacting a silicate oligomer represented by the formula in an organic solvent.

The polyol resin as a raw material of the silicate-modified polyol resin composition of the present invention has a hydroxyl value of 5 to 5.
300, the number average molecular weight is 500 to 20,000. When the hydroxyl value is less than 5, the reaction with the silicate oligomer is not sufficient, and when it exceeds 300, gelation easily occurs during the reaction or the viscosity of the obtained silicate-modified polyol resin composition becomes too high. On the other hand, if the number average molecular weight is less than 500, the compatibility with the binder component is insufficient, and if the number average molecular weight is more than 20,000, the viscosity increases, which causes a problem in handleability.

Examples of the kind of the polyol resin include an acrylic resin, a polyester resin, a fluorine resin and a melamine resin. Among these resins, those having the aforementioned hydroxyl value and number average molecular weight are:
It is well known to those skilled in the art as a coating resin, and in the present invention, a silicate-modified polyol resin composition can be obtained by using these polyol resins as raw materials.

Another raw material of the silicate-modified polyol resin composition of the present invention is a silicate oligomer represented by the following formula (I).

[0014]

Embedded image

(Wherein R may be the same or different and each represents an alkoxy group having 1 to 7 carbon atoms, a phenoxy group, an alkoxy group having 2 to 4 carbon atoms substituted by an alkoxy group having 1 to 4 carbon atoms, or A fluorinated alkoxy group,
May be an alkyl group having 1 to 4 carbon atoms, a phenyl group or a hydroxyl group. N is 1 to 20. )

Specific examples of the alkoxy group having 1 to 7 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a hexyloxy group and a benzyloxy group. Specific examples of the alkoxy group having 2 to 4 carbon atoms substituted with the alkoxy group having 1 to 4 carbon atoms include butyl cellosolve, isopropyl cellosolve, and a structure in which a hydrogen atom of a hydroxyl group is removed from 2- or 3-methoxypropanol. Things can be mentioned.
Examples of the fluorinated alkoxy group include a trifluoroethoxy group and a pentafluoropropoxy group.

As the silicate oligomer as a raw material for obtaining the silicate-modified polyol resin composition of the present invention, those having the same R in the molecule are commercially available and can be used as they are. Examples of such a material include methyl silicate and ethyl silicate. As methyl silicate, 51 (n = 5 as an average value) and 56 (n = 10 as an average value) are commercially available as MKC silicate series from Mitsubishi Chemical Corporation. , Ethyl silicate 40 (n =
5), ethyl silicate 40T (n =
5, ethyl silicate 40 obtained by removing tetraethoxysilane) and ethyl silicate 48 (n = 10 as an average value) are commercially available.

On the other hand, those having different Rs in the molecule can be obtained by substituting the above-mentioned alkyl group of methyl silicate or ethyl silicate with the above-mentioned alcohol containing an alkoxy group or a phenoxy group. As a fluorine silicate, GH-
100 are commercially available and may be used as they are.

Further, in the silicate oligomer, a part of R present in the molecule is an alkyl group having 1 to 4 carbon atoms;
It may be a phenyl group or a hydroxyl group. Such compounds are commercially available from Shin-Etsu Silicones, Inc., KC-89 substituted with a methyl group and KC-89 substituted with a phenyl group.
R-217, K substituted with methyl and phenyl groups
R-213 can be exemplified.

The silicate-modified polyol resin composition of the present invention can be obtained by reacting the above-mentioned polyol resin with the above-mentioned silicate oligomer in an organic solvent. The silicate-modified polyol resin composition obtained in this manner has excellent solubility in an organic solvent as compared with a silicate oligomer alone. The amount of the silicate oligomer in this reaction is preferably 0.1 to 10 times the mole of the hydroxyl group of the polyol resin. If the molar ratio is less than 0.1 times, the modification with the silicate oligomer does not sufficiently proceed, and even if the molar ratio exceeds 10 times, the obtained silicate-modified polyol resin composition has little difference and is inefficient. In order to prevent cracks, the amount of the silicate oligomer is more preferably 0.15 to 10 times the molar amount.

When the amount of the silicate oligomer is equal to or less than 1 mole of the hydroxyl group of the polyol resin, the hydroxyl group remains in the modified polyol resin. The silicate-modified polyol resin composition thus obtained is particularly excellent in solubility in organic solvents. on the other hand,
When the amount of the silicate oligomer is more than 1 mole relative to the hydroxyl group of the polyol resin, the silicate-modified polyol resin composition of the present invention contains a silicate oligomer that has not reacted with the hydroxyl group. In this case, it can be used for the coating composition of the present invention containing a silicate oligomer described below.

The above reaction is carried out in an organic solvent, but the organic solvent is not particularly limited as long as it does not affect the reaction. Further, considering that the silicate-modified polyol resin composition of the present invention is used for a paint, it is preferable to use an organic solvent used for the paint.

In the above reaction, a predetermined amount of the above polyol resin and the above silicate oligomer are added to an organic solvent,
The process proceeds by heating and stirring. The reaction conditions vary depending on the types of raw materials and organic solvents used, and can be arbitrarily set. For example, the solid content rate can be 50%, the reaction temperature can be 120 ° C., and the reaction time can be 3 hours. The end point of the reaction can be determined by measuring the viscosity, measuring the molecular weight by GPC, or quantifying the amount of alcohol produced by the reaction by gas chromatography. The silicate-modified polyol resin composition thus obtained can be added to a coating material, if necessary, by adjusting the solid content.

The coating composition of the present invention contains the above silicate-modified polyol resin composition and a binder component. As the binder component, those commonly used in paints can be used as they are. Examples of such a material include an acrylic resin, a polyester resin, a polyether resin, a polyurethane resin, a fluororesin, and an epoxy resin. These resins can be used in combination with a curing agent depending on the functional group of the resin.
Examples of such a curing agent include melamine, a polyisocyanate which may be blocked, a polycarboxylic acid, and a polyepoxy compound.

When the resin of the binder component contains a hydroxyl group, the polyol resin used in obtaining the silicate-modified polyol resin composition is used as the binder component, so that the silicate-modified polyol resin composition and the binder component can be used. Can be improved and cracks and cloudiness can be prevented.

The ratio of the silicate-modified polyol resin composition to the binder component in the coating composition of the present invention is not particularly limited.
0.5 / 100 to 80/20.

[0027] The coating composition of the present invention may further contain a silicate oligomer used as a raw material of the silicate-modified polyol resin composition of the present invention in order to improve stain resistance. In this case, the silicate oligomer may be the same as that used as the raw material of the silicate-modified polyol resin composition, or may be different, but from the viewpoint of preventing cracks and cloudiness, the same silicate oligomer may be used. preferable. When the silicate oligomer is contained, the solid content weight ratio of the silicate oligomer to the silicate-modified polyol resin composition is from 10/90 to 80 /
It is preferably 20. If it is less than 10/90, the effect of adding the silicate oligomer cannot be obtained, and if it is more than 80/20, cracks and cloudiness may occur.

In addition, the coating composition of the present invention may contain various components such as pigments and additives which are usually contained in coatings.

The coating composition of the present invention can employ various coating film forming methods from normal temperature drying to heat curing, depending on the type of the binder component contained therein. The coating film of the present invention thus formed is a coating film having no cracks and white turbidity and excellent in stain resistance.

[0030]

EXAMPLES Production Examples Methoxy substituted with a butoxyethoxy group
Manufacture of chill silicate To 672 parts by weight of MKC silicate 56 (manufactured by Mitsubishi Chemical Corporation, n = 10 as an average value) was added butyl cellosolve 226.8.
The mixture was heated and stirred at 90 ° C. for 1 hour and further at 120 ° C. for 3 hours while distilling off generated methanol.
This was allowed to cool to obtain 822.6 parts by weight of methyl silicate substituted with a butoxyethoxy group. The substitution rate of methoxy groups with butoxyethoxy groups in this silicate was 15.8%.

Example 1 Silicate-modified acrylic polio
Production of phenolic resin Part 1 Acrylic polyol resin obtained from styrene, acrylic acid, n-butyl acrylate, isobutyl methacrylate, 2-hydroxyethyl methacrylate (having a hydroxyl value of 69,
(Nonvolatile content 60% by weight) To 1251.1 parts by weight were added 2016.5 parts by weight of the methyl silicate substituted with a butoxyethoxy group obtained in Production Example and 1459.9 parts by weight of butyl acetate, Stirred for hours. This was cooled to obtain 4556.8 parts by weight of a silicate-modified acrylic polyol resin. This silicate-modified acrylic polyol resin has a viscosity of 15 cP and a number average molecular weight of 15,000.
Met.

Example 2 Silicate-modified acrylic polio
Production of phenolic resin Part 2 58.5 parts by weight of an acrylic polyol resin obtained from styrene, glycidyl methacrylate, 4-hydroxybutyl acrylate, and 2-ethylhexyl acrylate (hydroxyl value 69, nonvolatile content 58.5% by weight) 10. MKC silicate 51 (manufactured by Mitsubishi Chemical Corporation, n = 5 as an average value)
0 parts by weight and 11.5 parts by weight of butyl acetate,
Stirred at 0 ° C. for 5 hours. This was cooled to obtain 80.0 parts by weight of a silicate-modified acrylic polyol resin. The viscosity of this silicate-modified acrylic polyol resin is 18
It was 5.0 cP.

Example 3 Silicate-modified acrylic polio
Preparation of acrylic resin No. 3 Acrylic polyol resin LR-2562 (manufactured by Mitsubishi Rayon Co., Ltd., hydroxyl value 166, nonvolatile content 61% by weight) 83.8
79.4 parts by weight of MKC methyl silicate 56 (manufactured by Mitsubishi Chemical Corporation) and 192.3 parts by weight of butyl acetate were added to the parts by weight, and the mixture was stirred at 120 ° C. for 3.5 hours. This was cooled to obtain 80.0 parts by weight of a silicate-modified acrylic polyol resin. The viscosity of this silicate-modified acrylic polyol resin was 24.2 cP.

Example 4 Silicate-modified polyester resin
Production of Riol Resin Trimethylolpropane, neopentyl glycol, isononanoic acid, hexahydrophthalic acid, isophthalic acid, polyester polyol resin obtained from coconut oil (hydroxyl value 110, nonvolatile content 60% by weight) to 306.7 parts by weight,
480.0 parts by weight of methyl silicate substituted with a butoxyethoxy group obtained in Production Example 1 and 541.3 of xylene
And stirred at 120 ° C. for 3 hours. This was cooled to obtain 1327 parts by weight of a silicate-modified polyester polyol resin. The viscosity of this silicate-modified acrylic polyol resin was 23.2 cP.

Example 5 of silicate-modified melamine resin
Production 1 Super Beckamine 16-508 (manufactured by Dainippon Ink and Chemicals, isobutylated melamine, nonvolatile content 60% by weight)
To 10.0 parts by weight, 28.2 parts by weight of MKC silicate 56 (manufactured by Mitsubishi Chemical Corporation) and 18.8 parts by weight of butyl acetate were added, and the mixture was stirred at 120 ° C. for 3 hours. Cool it, 5
6.0 parts by weight of a silicate-modified melamine resin were obtained. This silicate-modified melamine resin had a viscosity of 7.0 cP and a number average molecular weight of 4,900.

Examples 6 and 7 Silicate-modified melamine
Preparation of resin No. 2 and No. 3 By the composition shown in Table 1 below, in the same manner as in Example 5,
A silicate-modified melamine resin was obtained. The yield and viscosity of the obtained silicate-modified melamine resin are also shown in Table 1.

[0037]

[Table 1]

Example 8 Silicate-Modified Fluorine Polyurethane
Production of Polyethylene Resin No. 1 Butoxy obtained in Production Example 1 was added to 20.0 parts by weight of a tetrafluoroethylene / vinyl ether copolymer resin Zeffle GK-510 (manufactured by Daikin Industries, Ltd., hydroxyl value 30, nonvolatile content 50% by weight). Methyl silicate substituted with ethoxy group 2
Add 9.3 parts by weight and 29.3 parts by weight of butyl acetate,
Stirred at 120 ° C. for 3 hours. This was cooled to obtain 78.0 parts by weight of a silicate-modified fluoropolyol resin. The viscosity of this silicate-modified fluoropolyol resin is 18
It was 5.0 cP.

Example 9 Silicate-Modified Fluorine Polyurethane
Preparation of vinyl resin 14.7 parts by weight of vinylidene difluoride copolymer KD215 (manufactured by Kanto Denka Kogyo Co., Ltd., hydroxyl value 78, nonvolatile content 50.2% by weight, fluorine content 38%), ethyl silicate 40
6.7 parts by weight (manufactured by Colcoat) and 7.7 parts by weight of butyl acetate were added, and the mixture was stirred at 120 ° C. for 3 hours. This was cooled to obtain 50.0 parts by weight of a silicate-modified fluoropolyol resin. The viscosity of this silicate-modified fluoropolyol resin was 20.0 cP.

Examples 10 to 14 and Comparative Examples 1 and 2
Coating composition containing silicate modified polyol resin composition?
Evaluation of coating film obtained from Unipon 400HK Taxi Yellow (Nippon Paint Co., Ltd.
Acrylic / polyester polyol / isocyanate curing system) 100 parts by weight of the silicate-modified acrylic polyol resin obtained in Example 1 and the methyl silicate substituted with a butoxyethoxy group obtained in Production Example 1 at the ratio shown in Table 2. Each was added, and the hydrolysis catalyst 1
By weight, the coating composition was obtained. The amount of the silicate-modified acrylic polyol resin in Table 2 is shown as the content of the silicate. This content is obtained by multiplying the weight ratio of the silicate in the raw material used for obtaining the content by the amount of the silicate-modified acrylic polyol resin. The coating composition thus obtained was applied to a polished steel sheet coated with an HK surfacer (manufactured by Atom Co.) as an intermediate coat, and a dry film thickness of 45 to 55 μm was applied.
Spray painted so that it becomes. The coating was cured by baking at 80 ° C. for 25 minutes. This was left overnight, the water contact angle of the coating film was measured, and it was visually confirmed whether or not cracks had occurred in the coating film. Table 2 shows the results. As a comparative example, experiments were also conducted on a system using only methyl silicate substituted with a butoxyethoxy group and a system without adding silicates.
It was shown to. Table 2 also shows the results of stain resistance of Example 14 and Comparative Example 2 visually evaluated one month after exposure.

[0041]

[Table 2]

From the above results, it was found that a silicate-modified polyol resin composition was obtained by reacting a silicate oligomer with various polyol resins. Further, a coating film obtained from a coating obtained by adding the obtained silicate-modified polyol resin composition to a coating material has a low water contact angle and does not cause cracking.

[0043]

Industrial Applicability The silicate-modified polyol resin composition of the present invention contains a silicate component, and when blended into a coating, can provide a coating film having excellent stain resistance. No generation or clouding. This is considered as follows. That is, the silicate-modified polyol resin composition of the present invention contains a resin having a structure in which silicate is grafted, and when this is blended in a paint, the condensation after hydrolysis of the silicate portion is more than that of a normal silicate compound. It is possible to prevent the occurrence of cracks, which do not easily progress and are considered to be caused by condensation. On the other hand, the polyol resin portion acts as a compatibilizer for the binder,
The domain size of the silicate present in the coating film is reduced, and the transparency of the coating film is increased. In addition, the coating film obtained from the coating material containing the silicate-modified polyol resin composition of the present invention can be expected to improve the recoat adhesion due to the presence of the silicate-modified polyol resin composition on the surface.

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Claims (5)

[Claims] (1) a hydroxyl value of 5 to 300 and a number average molecular weight of 50;
A silicate-modified polyol resin composition obtained by reacting a silicate oligomer represented by the following formula (I) with a polyol resin of 0 to 20,000 in an organic solvent. Embedded image (Wherein R may be the same or different, and has 1 to 1 carbon atoms)
7 is an alkoxy group having 7 carbon atoms, a phenoxy group, an alkoxy group having 2 to 4 carbon atoms or a fluorinated alkoxy group substituted with an alkoxy group having 1 to 4 carbon atoms, and a part of R is an alkyl group having 1 to 4 carbon atoms. , A phenyl group or a hydroxyl group. N is 1 to 20. ) 2. The silicate-modified polyol resin composition according to claim 1, wherein the amount of the silicate oligomer is 0.1 to 10 moles per mole of the hydroxyl group of the polyol resin. 3. The silicate-modified polyol resin composition according to claim 1, wherein the polyol resin is an acrylic resin, a polyester resin, a fluororesin or a melamine resin. 4. A coating composition comprising the silicate-modified polyol resin composition according to any one of claims 1 to 3 and a binder component. 5. A coating film obtained from the coating composition according to claim 4.