JPH11349815A - Production of organic/inorganic composite resin aqueous emulsion and coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing an organic/inorganic composite resin aqueous emulsion without using a metal chelate compound or a chelating agent and to provide a coating composition. SOLUTION: There is provided a process for producing an organic/inorganic composite resin aqueous emulsion, comprising the steps of: hydrolytically condensing 45-80% of the hydrolyzable functional groups of a mixture comprising (a) 100 pts.wt. at least either of an organosilane of the formula: R<1> n Si(OR<2> )4-n [wherein R<1> is a 1-8C organic group; R<2> is a 1-5C alkyl; and n is 1 or 2] or a partial hydrolyzate thereof and (b) 5-200 pts.wt. silyl-containing vinyl resin having hydrolyzable silyl groups or silyl groups having silicon-bonded hydroxyl groups and having an acid value of 20-150 mgKOH/g; adding 0.001-3 pts.wt., per 100 pts.wt., in total, unreacted components (a) and (b), trialkoxyborane of the formula: B(OR<3> )3 to the reaction product from the preceding step and hydrolytically polycondensing the resultant mixture; and emulsifying the product solution obtained from the preceding step by the addition of a neutralizing agent and water thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an organic-inorganic composite resin aqueous emulsion without using a metal chelate compound and a chelating agent, and to a weather resistance and a stain resistance containing the organic-inorganic composite resin aqueous emulsion. And a coating composition having excellent solvent resistance, hot water resistance and the like.

[0002]

2. Description of the Related Art A coating film containing an organic-inorganic composite resin obtained by subjecting an organosilane and / or a partially hydrolyzed condensate thereof and a silyl group-containing vinyl resin to a hydrolytic condensation reaction has a weather resistance and a stain resistance. In addition, the coating composition using the organic-inorganic composite resin as a binder has attracted attention. Is coming.

Heretofore, a Zr, Ti or Al metal chelate compound is usually used to carry out a hydrolysis condensation reaction between an organosilane and / or a partially hydrolyzed condensate thereof and a silyl group-containing vinyl resin. However, a coating composition using an organic-inorganic composite resin obtained using a metal chelate compound as a binder is used in combination with a chelating agent such as acetylacetone or ethyl acetoacetate to improve storage stability. When a metal container made of iron or the like is used as a storage container, the chelating agent tends to chelate with the metal container, and tends to corrode the metal container. Therefore, there is a problem that the metal container cannot be used. In fact, there is also concern about corrosion of metal coating machines.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and provides an aqueous emulsion of an organic-inorganic composite resin without using a metal chelate compound and a chelating agent. It is an object of the present invention to provide a coating composition comprising a method and an aqueous emulsion of an organic-inorganic composite resin and having excellent weather resistance, stain resistance, solvent resistance, hot water resistance and the like.

[0005]

Means for Solving the Problems The first invention comprises (i)
(A) General formula (1) R¹ _nSi (OR^Two)_4-n[Wherein, R
¹Is an organic group having 1 to 8 carbon atoms, R^TwoIs alk having 1 to 5 carbon atoms
And n is 1 or 2.]
100 parts of one or both of the partially hydrolyzed condensates
And (b) a hydrolyzable silyl group or a hydroxyl group.
Having a silyl group having a silicon atom and an acid value of 20
-150 mgKOH / g of silyl group-containing vinyl resin
The mixture consisting of 5 to 200 parts by weight is mixed with the water content in the mixture.
Hydrolytic shrinkage so that 45-80% of the decomposable functional groups are reacted
Reacting in step (ii) followed by step (i)
Component (a) and component (b) remaining unreacted with the reacted product
And the total amount of 100 parts by weight with respect to the general formula (2) B (O
R^Three)_Three[Wherein, R ^ThreeIs an organic group having 1 to 4 carbon atoms]
0.001 to 3 parts by weight of the trialkoxy borane shown
In addition, a step of performing a hydrolysis-condensation reaction, a step (iii)
A neutralizing agent and water are added to the reaction solution obtained in (ii).
And emulsifying, and if necessary, (iii)
Alcohol formed in the emulsion obtained in step (iii)
Removing the organic components under reduced pressure.
An object of the present invention is to provide a method for producing a fat-based aqueous emulsion.

The second invention provides a coating composition containing an aqueous emulsion of an organic-inorganic composite resin.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, each component used to produce the organic-inorganic composite resin aqueous emulsion of the first invention will be described.

<Component (a)> The component (a) is represented by the general formula (1): R ¹ _n Si (OR ² ) _4-n [wherein R ¹ has ¹ carbon atom
To 8 organic groups, R ² is an alkyl group having 1 to 5 carbon atoms, and n is 1 or 2] and / or a partial hydrolysis condensate thereof.

R ¹ in the above formula is an organic group having 1 to 8 carbon atoms, for example, an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a γ-chloropropyl group, Vinyl group, 3,3,3-trifluoropropyl group, γ-glycidoxypropyl group, γ-methacryloxypropyl group, γ-mercaptopropyl group, phenyl group, 3,4-epoxycyclohexylethyl group, γ-
And an aminopropyl group.

R ² in the general formula is an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and an s-butyl group. , T-butyl group, i-butyl group and the like.

Specific examples of these organosilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyl Trimethoxysilane, i-propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyl Pills triethoxysilane, .gamma.-mercaptopropyltrimethoxysilane, .gamma.
Mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-aminopropyltrimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltriethoxysilane, dimethyldimethoxysilane, Dimethyl diethoxy silane, diethyl dimethoxy silane, diethyl diethoxy silane, diphenyl dimethoxy silane, diphenyl diethoxy silane, dimethoxy methyl phenyl silane, dimethyl dipropoxy silane and the like, preferably methyl trimethoxy silane, methyl triethoxy silane , Dimethyldimethoxysilane. These organosilanes
One type may be used alone, or two or more types may be used in combination.

The component (a) may be a partially hydrolyzed condensate of the organosilane described above. The polystyrene equivalent weight average molecular weight of the condensate is suitably from 300 to 5,000, preferably from 500 to 3,000, and the use of a condensate having such a molecular weight does not deteriorate the storage stability and provides a coating film having good adhesion. Is obtained. The partially hydrolyzed condensate of the organosilane, an -OH group or -OR ² group bonded to a silicon atom 1 or more, preferably 3 to 3
Those having zero are suitable.

Specific examples of such condensates include commercially available products of SH6018 and S6018 manufactured by Dow Corning Toray.
R2402, DC3037, DC3074, KR-211, KR-212, KR-213 manufactured by Shin-Etsu Chemical Co., Ltd.
KR-214, KR-216, KR-218, TSR-145, TSR-160, TSR manufactured by Toshiba Silicone Co., Ltd.
-165, YR-3187 and the like.

In the present invention, the component (a) is composed of an organosilane having an n value of 1 and / or its partially hydrolyzed condensate (a-1) and an organosilane having an n value of 2 and / or The weight ratio with the partially hydrolyzed condensate (a-2) is (50:50 to 100: 0), preferably (60:40).
-95: 5) is desirable because the mixture is polymerized stably when producing the binder and a coating film having good crack resistance can be obtained.

<Component (b)> The component (b) contains at least one silyl group having a silicon atom bonded to a hydrolyzable silyl group or a hydroxyl group at the terminal or side chain in one molecule of the resin.
, Preferably 2 or more, and an acid value of 20 to 150.
It is a vinyl resin having a molecular weight of about 1,000 to 50,000 in mgKOH / g.

The silyl group is represented by the general formula (3) -SiX_P
(R^Three)_(3-P)[Wherein X is alkoxy, acyloxy, ha
Rogen, ketoximate, amino, acid amide, amido
Xy, mercapto, alkenyloxy, phenoxy, etc.
A hydrolyzable group or a hydroxyl group; R ^ThreeIs hydrogen or carbon number 1 to 1
0 monovalent groups such as alkyl, aryl, aralkyl, etc.
Hydrocarbon group; P is an integer of 1 to 3]
It is.

The silyl group-containing vinyl resin has the general formula (4)

[0018]

Embedded image [Wherein X, R ³ and P are the same as described above], and a vinyl resin having a carbon-carbon double bond is reacted according to a conventional method.

As the above-mentioned hydrosilane compound, methyl dichlorosilane, methyl diethoxy silane, methyl diacetoxy silane, methyl diaminooxy silane and the like can be mentioned as typical examples. The amount of the hydrosilane compound to be used is appropriately 0.5 to 2 moles per mole of the carbon-carbon double bond contained in the vinyl resin.

The vinyl resin contains a carboxylic acid such as (meth) acrylic acid, itaconic acid and fumaric acid or an acid anhydride such as maleic anhydride as an essential vinyl monomer, and further comprises methyl (meth) acrylate, (Meth) acrylic acid esters such as ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylic acid; epoxy compounds such as glycidyl (meth) acrylate; acrylonitrile; Styrene, α-methylstyrene, vinyl acetate,
It is a copolymer of a vinyl monomer selected from the group consisting of vinyl propionate and the like, and is produced in the vinyl resin by radically copolymerizing allyl (meth) acrylate or diallyl phthalate during the production of the copolymer. The introduction of a carbon-carbon double bond for the hydrosilylation reaction is possible.

The above-mentioned carboxylic acid or acid anhydride is
The acid value of the vinyl resin obtained in the constituent monomer of the copolymer is 20 to 150 mgKOH / g, preferably 50 to 1 mgKOH / g.
It needs to be contained so as to be 20 mgKOH / g.
When the acid value is smaller than the above range, the storage stability of the obtained aqueous emulsion is deteriorated. On the contrary, when the acid value is larger, the water resistance of the obtained coating film is deteriorated.

Other production methods include the above-mentioned vinyl monomers containing a carboxylic acid or an acid anhydride and 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyvinyl ether and the like. Hydroxyl-containing monomer and γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, β- (meth) acryloxyethyltrimethoxysilane, β- (meth) acryloxyethyltriethoxy Silane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ
-Silyl such as (meth) acryloxypropylmethyldipropoxysilane, γ- (meth) acryloxybutylphenyldimethoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, and γ- (meth) acryloxypropyldiethylmethoxysilane There is also a method of radically polymerizing a group-containing vinyl compound.

Next, a method for producing the aqueous organic-inorganic composite resin emulsion of the first invention will be described. First, in the step (i), the components (a) and (b) are subjected to hydrolysis and condensation in the presence of water and a catalyst. The mixing ratio of the component (a) and the component (b) is based on 100 parts by weight of the former.
The latter is suitably from 5 to 200 parts by weight, preferably from 10 to 150 parts by weight. Incidentally, if the latter is less than the above range, the appearance and crack resistance of the obtained coating film, the frost damage resistance, the alkali resistance, etc. are deteriorated, and the storage stability of the obtained coating composition is deteriorated. It is not preferable because the weather resistance and the like of the obtained coating film deteriorate.

In step (i), the amount of water is from 45 to 80 of the hydrolyzable functional group in the mixture of component (a) and component (b).
%, Preferably 50 to 70%, of 0.4 to 0.9 with respect to 1 equivalent of the hydrolyzable functional group such that hydrolysis and condensation reaction occur.
An equivalent, preferably 0.5 to 0.8 equivalent is appropriate.

Examples of the catalyst include inorganic acids such as nitric acid and hydrochloric acid, and organic acids such as acetic acid, formic acid and propionic acid. The amount of the catalyst is such that the pH of the coating composition is
An amount such that it becomes 6 is appropriate. The hydrolysis condensation reaction is
A method in which the components (a) and (b) are mixed in the presence of water and a catalyst and reacted at 40 to 80 ° C., preferably 45 to 65 ° C. for 2 to 5 hours is suitable, but is not limited thereto. is not.

In the hydrolysis and condensation reaction in the step (i), the reaction of the component (a) mainly occurs due to the reaction rate,
The reaction between the component (b) or the component (a) and the component (b) (grafting reaction by a condensation reaction) is slow. As described above, in step (i), the hydrolysis and condensation reaction
The reason for setting the content of the hydrolyzable functional group in the mixture of the component (a) and the component (b) to 45 to 80% is that the storage stability of the product is good and a highly transparent film can be formed. , 45
If the amount is less than 80%, a film having poor transparency is formed, resulting in poor appearance. If the amount exceeds 80%, the storage stability of the product is unfavorably deteriorated.

Subsequent to the step (i), in the step (ii),
Further, water and the general formula (2) B (OR ^Three)_Three[Wherein, R
^ThreeIs an organic group having 1 to 4 carbon atoms.]
The lucoxiborane is added to cause hydrolysis and condensation reaction.
The amount of water was obtained by the hydrolysis and condensation reaction in step (i).
1 equivalent or more per 1 equivalent of the remaining hydrolyzable functional group
Above, preferably 1.2 to 2 equivalents are suitable.

Examples of the trialkoxyborane represented by the general formula (2) include trimethoxyborane, triethoxyborane, tripropoxyborane, and tributoxyborane. Trialkoxyborane is
It is used for accelerating the condensation reaction between the component (a) and the component (b) and improving the appearance, weather resistance, stain resistance, hot water resistance and the like of the coating film.

Therefore, the amount of trialkoxy borane is 0.1 part by weight based on 100 parts by weight of the total amount of the reactant obtained in step (i) and the unreacted components (a) and (b).
001 to 3 parts by weight, preferably 0.005 to 1 part by weight is suitable. If the amount of trialkoxy borane is less than the above range, the condensation reaction will be insufficient, and the above-mentioned effect of improvement will not be obtained. Conversely, if the amount is too large, the reaction stability will deteriorate, which is not preferable.

The hydrolysis and condensation reaction in the step (ii) is carried out at 40 to 80 ° C., preferably 45 to 80 ° C., as in the step (i).
It is appropriate to react at 65 ° C. for 2 to 5 hours. The hydrolysis-condensation reaction product obtained in the step (ii) is in a solution state by the generated alcohol component or an organic solvent added thereto as required, which will be described later.

In the step (iii) following the step (ii), a neutralizing agent is added to the solution of the organic-inorganic composite resin, which is the reaction product obtained in the step (ii), and the solution is uniformly dispersed and neutralized. Thereafter, water is added, or a neutralizing agent and water are simultaneously added, and the mixture is stirred to forcibly emulsify and emulsify.

The amount of the neutralizing agent is set to 50 to 100 of the acid groups in the organic-inorganic composite resin so that a stable emulsion can be obtained.
%, Preferably 70-100%. In addition, as a neutralizing agent, triethylamine, triethanolamine, dimethylethanolamine, monoethanolamine, N-methyldiethanolamine, N, N
-Dimethylethanolamine, morpholine and the like are typical examples. In addition, the amount of water is arbitrarily determined in consideration of the workability of coating and the like. However, the amount of water is generally appropriate such that the solid content of the coating composition becomes 10 to 50% by weight.

In the organic / inorganic composite resin aqueous emulsion thus obtained, an alcohol component is produced by the above-mentioned hydrolysis-condensation reaction and remains in the emulsion. Therefore, when the emulsion is used as it is as a coating composition, the volatile organic component (VOC) increases, so that the alcohol content may be removed under reduced pressure according to a conventional method.

Next, the coating composition of the second invention will be described. The coating composition uses the above-mentioned organic-inorganic composite resin as a binder, and the emulsion further contains an organic solvent, a filler, a dye, and a curing agent for improving the storage stability and coating workability of the coating composition as necessary. It is composed of various additives such as an accelerator, a thickener, and a pigment dispersant.

Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, and butanol.
Alcohol ethers such as ethylene glycol monoethyl ether and ethylene glycol monobutyl ether;
It is possible to use a hydrophilic organic solvent such as ketones such as acetone and methyl ethyl ketone, or a mixed organic solvent thereof with a hydrophobic organic solvent for various coatings such as toluene, xylene, ethyl acetate and butyl acetate. In addition, these organic solvents can be blended as a solvent in the above-mentioned step (i) and step (ii) so that the reaction occurs uniformly.

As the filler, extenders and coloring pigments for various paints such as talc, barium carbonate, calcium carbonate, bentonite, titanium oxide, carbon black, red iron, lithopone and the like can be used.

Examples of the curing accelerator include organotin compounds such as tin octylate, dibutyltin dilaurate, dibutyltin dimaleate and tributyltin laurate, ethylenediamine, diethylenetriamine, piperidine and the like.
Typical examples include amine compounds such as phenylenediamine and triethylamine, and organic tin compounds are particularly effective.

The coating composition of the present invention is formed by applying a coating method such as brush, spray, roll, dipping or the like on the surface of the object to be coated, and baking at room temperature or at a temperature of 300 ° C. or less to form a cured coating film. Is possible. The object to be coated can be applied to various substrates such as a dance machine ceramic substrate, various metal substrates such as stainless steel and aluminum, a glass substrate, a plastic substrate, and a paper substrate.

[0039]

The present invention will be described in more detail with reference to the following examples. In the examples, "parts" and "%" are shown on a weight basis unless otherwise specified.

<Preparation of Silyl Group-Containing Vinyl Resin Solution (A)> Into a reactor equipped with a reflux condenser and a stirrer, 100 parts of ethylene glycol monobutyl ether was added and heated to 100 ° C. while stirring. Next, 50 parts of isobutyl methacrylate and 31.5 parts of 2-ethylhexyl methacrylate were used.
Part, γ-methacryloxypropyltrimethoxysilane 1
0 parts, a mixed solution of 8.5 parts of acrylic acid and 2.5 parts of t-butylperoxy-2-ethylhexanoate were added dropwise at 100 ° C. over 3 hours, and then the temperature was raised to 105 ° C. and maintained for 2 hours. The reaction was terminated.

The obtained silyl group-containing vinyl resin solution (a) has a solid concentration of 50% and an acid value of the resin of 65%.
mgKOH / g, the number average molecular weight was 10,000, and the polymer-1 molecule had an average of about 7 silyl groups per molecule.

<Preparation of Silyl Group-Containing Vinyl Resin Solution (B)> To a reactor equipped with a reflux condenser and a stirrer was added 100 parts of ethylene glycol monobutyl ether, and the mixture was heated to 100 ° C. with stirring. Next, 50 parts of isobutyl methacrylate, 2-ethylhexyl methacrylate 3
1.5 parts, 8.5 parts of γ-methacryloxypropyltrimethoxysilane, a mixed solution of 10.5 parts of acrylic acid and 2.5 parts of t-butylperoxy 2-ethylhexanoate,
The mixture was added dropwise at 100 ° C. over 3 hours, and then heated to 105 ° C. and maintained for 2 hours to complete the reaction.

The obtained silyl group-containing vinyl resin solution (b) had a solid content of 50%, and the acid value of the resin was 80%.
mgKOH / g, number average molecular weight was 10,000, and polymer-1 molecule had an average of 6 silyl groups.

Example 1 A reactor equipped with a reflux condenser and a stirrer was charged with (a) a partially hydrolyzed condensate of methyltrimethoxysilane (SR24 manufactured by Dow Corning Toray Co., Ltd.).
02; solid content 100%) 23 parts, methyltrimethoxysilane 8 parts, dimethyldimethoxysilane 1.7 parts,
(B) After adding and mixing 16 parts of the silyl group-containing vinyl resin solution (a) and 10 parts of isopropanol, 3.0 parts of ion-exchanged water and 1 N hydrochloric acid were added so that the pH became 4, and 6 parts were added.
The reaction was performed at 0 ° C. for 3 hours.

The reaction product obtained has the hydrolyzable functional group 6
0% had undergone a hydrolysis-condensation reaction (measured by a gas chromatography method). Then, 0.3 parts of triethoxyborane and 2.5 parts of ion-exchanged water were added, and the mixture was reacted at 60 ° C. for 3 hours.
Next, 0.4 parts of N, N-dimethylethanolamine and 37 parts of water were added, and the mixture was stirred at 50 ° C. for 1 hour, and then cooled to obtain an organic-inorganic composite resin aqueous emulsion having a solid content of 35%.

Example 2 In a reactor equipped with a reflux condenser and a stirrer, (a) a partially hydrolyzed condensate of methyltrimethoxysilane (SR24 available from Dow Corning Toray Co., Ltd.)
02) 23 parts, methyltrimethoxysilane 8 parts, dimethyldimethoxysilane 1.7 parts, (b) 25 parts of a silyl group-containing vinyl resin solution (b) and 10 parts of isopropanol were added and mixed, and then ion-exchanged water was added. 3.0 parts and 1N hydrochloric acid were added to adjust the pH to 4, and the mixture was reacted at 60 ° C. for 3 hours.

The obtained reaction product has a hydrolyzable functional group 6
0% had a hydrolytic condensation reaction. Next, 0.1 part of triethoxyborane and 2.5 parts of ion-exchanged water were added, and
The reaction was carried out at a temperature of 3 ° C. for 3 hours. Next, 0.7 part of N, N-dimethylethanolamine and 40 parts of water were added, and the mixture was stirred at 50 ° C. for 1 hour, and then cooled to obtain an organic-inorganic composite resin aqueous emulsion having a solid content of 35%.

Example 3 In a reactor equipped with a reflux condenser and a stirrer, (a) a partially hydrolyzed condensate of methyltrimethoxysilane (SR24 manufactured by Dow Corning Toray Co., Ltd.)
02) 17.5 parts, methyltrimethoxysilane 11 parts, and (b) a silyl group-containing vinyl resin solution (b) 13.
After 5 parts and 5 parts of isopropanol were added and mixed, 2.6 parts of ion-exchanged water and 1N hydrochloric acid were added so that the pH became 4, and the mixture was reacted at 60 ° C. for 3 hours.

The reaction product obtained has a hydrolyzable functional group 6
0% had a hydrolytic condensation reaction. Next, 0.2 parts of triethoxyborane and 2.0 parts of ion-exchanged water were added, and
The reaction was carried out at a temperature of 3 ° C. for 3 hours. Next, 0.4 parts of N, N-dimethylethanolamine and water 40 were added, and the mixture was stirred at 50 ° C. for 1 hour and then cooled to obtain an organic-inorganic composite resin aqueous emulsion having a solid content of 35%.

Example 4 In a reactor equipped with a reflux condenser and a stirrer, (a) 30 parts of methyltrimethoxysilane, 10 parts of dimethyldimethoxysilane, and (b) a vinyl resin solution containing a silyl group (a) 16) and 5 parts of isopropanol were added and mixed. Then, 5.2 parts of ion-exchanged water and 1N hydrochloric acid were added so that the pH became 4, and the mixture was reacted at 60 ° C for 3 hours.

The obtained reaction product has 4 hydrolyzable functional groups.
5% had a hydrolytic condensation reaction. Next, 0.2 parts of triethoxyborane and 5.0 parts of ion-exchanged water were added, and
The reaction was carried out at a temperature of 3 ° C. for 3 hours. Next, 5 parts of ethylene glycol monobutyl ether, 0.4 part of N, N-dimethylethanolamine and water 40 were added, and the mixture was stirred at 50 ° C. for 1 hour. An aqueous organic-inorganic composite resin emulsion having a concentration of 34% was obtained.

Comparative Example 1 (a) A partially hydrolyzed condensate of methyltrimethoxysilane (SR24 manufactured by Dow Corning Toray Co., Ltd.) was placed in a reactor equipped with a reflux condenser and a stirrer.
02) 23 parts, methyltrimethoxysilane 8 parts, dimethyldimethoxysilane 1.7 parts, (b) 16 parts of a silyl group-containing vinyl resin solution (a) and 10 parts of isopropanol were added, mixed, and then ion-exchanged water. 1.0 part and 1N hydrochloric acid were added to adjust the pH to 4, and reacted at 60 ° C. for 3 hours.

The obtained reaction product has one of the hydrolyzable functional groups.
5% had a hydrolytic condensation reaction. Next, 0.3 parts of triethoxyborane and 2.5 parts of ion-exchanged water were added, and
The reaction was carried out at a temperature of 3 ° C. for 3 hours. Next, 0.4 parts of N, N-dimethylethanolamine and 37 parts of water were added, and the mixture was stirred at 50 ° C. for 1 hour and then cooled to obtain an organic-inorganic composite resin aqueous emulsion having a solid content of 32%.

(Comparative Example 2) In a reactor equipped with a reflux condenser and a stirrer, (a) a partially hydrolyzed condensate of methyltrimethoxysilane (SR24 manufactured by Dow Corning Toray Co., Ltd.)
02) 23 parts, methyltrimethoxysilane 8 parts, dimethyldimethoxysilane 1.7 parts, (b) 16 parts of a silyl group-containing vinyl resin solution (a) and 10 parts of isopropanol were added, mixed, and then ion-exchanged water. 3.0 parts and 1N hydrochloric acid were added so that the pH became 4, and reacted at 60 ° C. for 3 hours.

The reaction product obtained has the hydrolyzable functional group 6
0% had a hydrolytic condensation reaction. Next, 0.3 parts of diisopropylaluminum ethyl acetoacetate and 2.5 parts of ion-exchanged water were added and reacted at 60 ° C. for 3 hours. Next, 5 parts of acetylacetone, 0.4 part of N, N-dimethylethanolamine and 32 parts of water were added, and the mixture was stirred at 50 ° C. for 1 hour, and then cooled to obtain an organic-inorganic composite resin aqueous emulsion having a solid content of 35%. Was.

Comparative Example 3 In a reactor equipped with a reflux condenser and a stirrer, (a) 30 parts of methyltrimethoxysilane, 10 parts of dimethyldimethoxysilane, and (b) a silyl group-containing vinyl resin solution (Bell) After adding and mixing 16 parts of Kanekazemurak (manufactured by Fuchi Chemical Industry Co., Ltd .; acid value 0, solid content: 50%) and 16 parts of isopropanol, 5.4 parts of ion-exchanged water and 1N hydrochloric acid become pH 4. And reacted at 60 ° C. for 3 hours.

The obtained reaction product has a hydrolyzable functional group of 5
0% had a hydrolytic condensation reaction. Next, 0.2 parts of triethoxyborane and 5.0 parts of ion-exchanged water were added, and
The reaction was carried out at a temperature of 3 ° C. for 3 hours. Next, 5 parts of ethylene glycol monobutyl ether and 40 parts of ion-exchanged water were added, and
After stirring at 0 ° C. for 1 hour, methanol produced by the reaction at 60 ° C. under reduced pressure was removed to obtain an organic-inorganic composite resin aqueous emulsion having a solid content concentration of 32%. The aqueous emulsion was unsuitable for use as a coating agent because the resin component separated and precipitated.

The coating composition obtained by adding 5 parts of an aqueous dispersion (solid content: 10%) of dibutyltin dilaurate to 100 parts of the organic-inorganic composite resin aqueous emulsion obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was as follows: Corrosion and appearance of the resulting coating film, hardness, hot water resistance, stain resistance, weather resistance, solvent resistance, and alkali resistance were tested, and the results are shown in Table 1.

The test was performed according to the following method.

<Corrosion Test> After leaving the coating composition in an iron container for one week, the color of the composition was observed.

<Coating Film Performance Test> A gypsum slag perlite plate (12 mm thick) was used as a material, and a polyisocyanate prepolymer solution sealer “V-Seran # 1” was formed on the surface of the plate.
00 sealer "(trade name, manufactured by Dai Nippon Paint Co., Ltd.) (100% dilution with a solution of butyl acetate: xylene = 1: 1) by spray coating so that the coating amount becomes 90 to 100 g / m ² (wet weight). did. This was dried at 100 ° C. for 5 minutes.

Next, an acrylic silicone resin-based paint “V-Selan # 500 Enamel” (trade name, manufactured by Dainippon Paint Co., Ltd.) (butyl acetate: xylene = 1: 1) was used as a base paint.
(40% diluted with the solution of No. 1) at a coating amount of 80 to 90 g / m ^2.
(Wet weight). This is 120
Dry at 15 ° C. for 15 minutes. Then, the coating amount obtained by adding 3 parts of dibutyltin dilaurate to 100 parts by weight of each of the above-mentioned coating compositions was 130 ± 10 g / m ² (wet).
Weight). This at 120 ° C for 15
After drying for 3 minutes, it was dried at room temperature for 3 days.

Appearance: The appearance of the coating film was visually determined. Hardness: Pencil hardness measured according to JIS K 5400 Hot water resistance: The test piece was immersed in tap water at 60 ° C. for 7 days, and the abnormality of the appearance of the coating film was visually determined. ○ ・ ・ ・ No change △ ・ ・ ・ Minor change such as gloss reduction, whitening etc. × ・ ・ ・ Large change such as gloss reduction, whitening etc. Stain resistance: decontamination property of red and black magic ink after 24 hours ◎・ ・ ・ Complete removal ○ ・ ・ ・ Extremely slight contamination △ ・ ・ ・ Stain × × Severe contamination Weather resistance: Sunshine weather o-meter 3000 hours ○ ・ ・ ・ No change in coating film appearance, gloss retention 95 %
Δ: The appearance change of the coating film is slight, and the gloss retention is 8
0 to 94% × The coating film change is remarkable, gloss retention is less than 80%. Solvent resistance: A rubbing test was performed 50 times with a cloth wetted with xylene, and the coating film surface was visually evaluated. ○ ・ ・ ・ No change △ ・ ・ ・ Paint film surface turbidity × ・ ・ ・ Paint film surface partially dissolved Alkali resistance: 4 pieces of each coated plate in saturated slaked lime alkaline aqueous solution
After immersion at 00 ° C. for 1 week, the coating film surface was visually evaluated. ○ ・ ・ ・ No change △ ・ ・ ・ Slightly cloudy on the film surface × ・ ・ ・ Cloudy on the film surface

As is clear from Table 1, Example 1 of the present invention
The coating compositions using the aqueous organic-inorganic composite resin emulsions of Nos. To 4 did not corrode iron containers and had excellent coating performance. On the other hand, the coating composition using the organic-inorganic composite resin aqueous emulsion of Comparative Example 1 having a low hydrolysis-condensation reaction rate in step (i) was not transparent, and was poor in hot water resistance, alkali resistance, and solvent resistance.
In Comparative Example 2 using a metal chelate compound, it was found that the composition turned red when stored in an iron container and was red rust which corroded the container.

[0065]

[Table 1]

[0066]

According to the present invention, an aqueous emulsion of an organic-inorganic composite resin can be produced without using a metal chelate compound and a chelating agent, and a coating composition using the emulsion can be stored in a metal container. Without corrosion, the resulting coating is weather resistant, stain resistant,
Excellent in solvent resistance, hot water resistance, etc.

Claims (4)

[Claims] 1. (i) (a) General formula (1) R ¹ _n Si
(OR ² ) _{4-n wherein} R ¹ is an organic group having 1 to 8 carbon atoms, R ²
Is an alkyl group having 1 to 5 carbon atoms, n is 1 or 2], 100 parts by weight of one or both of the partially hydrolyzed condensate and (b) a hydrolyzable silyl group or a hydroxyl group. A mixture of 5-200 parts by weight of a silyl group-containing vinyl resin having a silyl group having a silicon atom bonded thereto and having an acid value of 20 to 150 mgKOH / g is mixed with 45 to 45 of hydrolyzable functional groups in the mixture. A step of conducting a hydrolysis-condensation reaction so that 80% is reacted, and then (i)
i) With respect to 100 parts by weight of the total amount of the reactant obtained in step (i) and the components (a) and (b) remaining unreacted, the general formula (2) B (OR ³ ) ₃ [formula Wherein R ³ is an organic group having 1 to 4 carbon atoms], and adding 0.001 to 3 parts by weight of a trialkoxy borane represented by the following formula (II) to carry out a hydrolytic condensation reaction, (iii) obtained in the step (ii). Adding a neutralizing agent and water to the reactant solution and emulsifying the solution to produce an aqueous organic-inorganic composite resin emulsion. 2. (i) (a) General formula (1) R ¹ _n Si
(OR ² ) _{4-n wherein} R ¹ is an organic group having 1 to 8 carbon atoms, R ²
Is an alkyl group having 1 to 5 carbon atoms, n is 1 or 2], 100 parts by weight of one or both of the partially hydrolyzed condensate and (b) a hydrolyzable silyl group or a hydroxyl group. A mixture consisting of 5 to 200 parts by weight of a silyl group-containing vinyl resin having a silyl group having a silicon atom bonded thereto and an acid value of 20 to 150 mgKOH / g is mixed with 45 to 45 hydrolyzable functional groups in the mixture. A step of conducting a hydrolysis-condensation reaction so that 80% is reacted, and then (i)
i) With respect to 100 parts by weight of the total amount of the reactant obtained in step (i) and the components (a) and (b) remaining unreacted, the general formula (2) B (OR ³ ) ₃ [formula Wherein R ³ is an organic group having 1 to 4 carbon atoms], and adding 0.001 to 3 parts by weight of a trialkoxy borane represented by the following formula (II) to carry out a hydrolytic condensation reaction, (iii) obtained in the step (ii). Adding a neutralizing agent and water to the reaction solution and emulsifying the solution, (iii)
Removing the produced alcohol component from the emulsion obtained in the step (iii) under reduced pressure. 3. The hydrolyzable functional group 1 so that 45 to 80% of the hydrolyzable functional groups in the mixture of the component (a) and the component (b) undergo the hydrolysis and condensation reaction in the step (i). The method for producing an organic-inorganic composite resin aqueous emulsion according to claim 1 or 2, wherein 0.4 to 0.9 equivalent of water is present relative to the equivalent. 4. A coating composition comprising the organic / inorganic composite resin aqueous emulsion according to claim 1 or 2.