JPH05331353A - Precursor sol composition for ketone resin/silica glass hybrid and preparation of the hybrid - Google Patents

Abstract

PURPOSE:To provide a precursor sol composition for preparing a high- performance ketone resin/silica glass hybrid having high hardness, high glass, transparency and good water and solvent resistances, etc., and to provide the hybrid preparation process. CONSTITUTION:The composition comprises a mixture of a ketone resin precondensate (A) and a hydrolyzable alkoxysilane or a polycondensate (B) of its partial hydrolyzate and an acid catalyst in an A to B weight ratio of 2/1-1/8 (in terms of the solid matter). This composition is applied to or infiltrated into a base and dried to obtain a ketone resin/silica glass hybrid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precursor sol composition of a ketone resin / silica glass hybrid body and a method for producing the hybrid body.

[0002]

2. Description of the Related Art Generally, the surface of an inorganic substance and the surface of an organic substance have a low affinity for each other, and it is very difficult to hybridize both materials. In recent years, tetraethoxy has been attracting attention as a method for producing a catalyst carrier or a new glass. Attempts have been made to synthesize a hybrid of an organic polymer and an inorganic glass by the sol-gel method utilizing hydrolysis and polycondensation of silane.

As the polymers that have been studied so far, many water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyoxazoline, and sodium polystyrene sulfonate are known. However, the organic / inorganic hybrid material obtained by using these has poor water resistance and has a porous structure, which is still unsatisfactory in terms of practicality.

In addition, when examining organic / inorganic hybrids, thermosetting resins as organic materials have hardly been the subject of research.

[0005]

In view of the above-mentioned prior art, the present invention uses a thermosetting oligomer resin as an organic polymer component and can provide a versatile organic / inorganic hybrid material which can be applied. The object is to develop a composition as a body and an organic / inorganic hybrid body obtained from the composition. In other words, it is a hybrid that can be applied to a wide range of applications such as paints, floor coatings, surface protection of electronic parts, wood, plastic molded products, etc., and has excellent performance such as transparency, hardness, adhesion, solvent resistance, etc. It is an object to provide a body and a sol composition as a precursor thereof.

[0006]

Means for Solving the Problems To solve the above problems, the inventors of the present invention have conducted earnest studies on the types of organic materials and inorganic materials, the ratios of their use, etc. Using a specific sol composition consisting of a polymerizable resin initial condensate, an alkoxysilane and an acid catalyst, and then applying and drying this, it is finally found that the target hybrid body is formed, and the present invention It came to completion.

That is, the present invention comprises (A) a ketone resin initial condensate, (B) a hydrolyzable alkoxysilane or a partially hydrolyzed polycondensate thereof, and an acid catalyst, and comprises (A) component and (B) component. And the solid content ratio is (A) /
(B) = a mixture of 2/1 to 1/8, a precursor sol composition of a ketone resin / silica glass hybrid body, and a precursor sol composition coated or impregnated on a substrate, The present invention relates to a method for producing a ketone resin / silica glass hybrid body characterized by being dried.

[0008]

Functions and Examples The above-mentioned ketone resin precondensate which is a thermosetting precondensate used in the present invention (hereinafter (A))
The component) is not particularly limited, but examples thereof include various initial condensates obtained from formaldehyde and ketones. Examples of the above-mentioned ketones include acetone, methyl ethyl ketone, methyl isopropenyl ketone, cyclohexanone and the like, and these can be usually used alone or in combination of two or more kinds. For example, a typical acetone resin initial condensate of the component (A) is generally acetone and formaldehyde in an amount of about 1 to 6 times this amount in the presence of an alkali catalyst such as sodium hydroxide or calcium hydroxide. 40 to 70 ° C
It is obtained by heating and condensing in an aqueous medium while keeping the temperature at a certain level. That is, it is an initial condensate containing methylolacetone or dimethylolacetone as a constituent unit, and these can usually be obtained as a viscous water-soluble resinous substance formed by secondary polycondensation. A modified ketone resin initial condensate obtained by substituting less than about 30 mol% of the above ketones with urea or melamine may be used as the component (A).

Since the properties of the component (A) vary depending on the condensation ratio of ketones and formaldehyde and other reaction conditions, the optimum properties cannot be unconditionally determined, but usually the number average molecular weight is 500. A low-viscosity aqueous solution having a solid content of about 30 to 60% (weight%, the same applies hereinafter) can be suitably used.

Examples of the hydrolyzable alkoxysilane (hereinafter referred to as the component (B)) used in the present invention include the general formula: Si (OR) m (wherein R is a saturated hydrocarbon residue having 1 to 4 carbon atoms). Group, m is an integer of 2 to 4) and lower alkoxysilanes. Specific examples of the hydrolyzable alkoxysilane include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and tetrabutoxysilane; trimethoxymethylsilane, triethoxymethylsilane, trimethoxyethylsilane and the like. Examples thereof include trialkoxyalkylsilanes, and one or more partially hydrolyzed polycondensates corresponding to these. The component (B) is usually used alone or in 2
It is used as a mixture of two or more species.

In the present invention, an acid catalyst is essential to accelerate the hydrolysis and polycondensation of the component (B). As the catalyst, for example, hydrogen halide such as hydrogen chloride and hydrogen bromide, organic strong acid such as p-toluenesulfonic acid, benzenesulfonic acid, and decanesulfonic acid are preferable, and the catalyst is usually used alone or in combination of two or more kinds. Used as a mixture. Further, since the catalyst generally affects the stability of the obtained sol composition and the coloring of the hybrid membrane, lower alcohol such as methanol and ethanol or water is usually added so that the catalyst concentration is about 5 to 10%. It is preferable to use it after diluting and dissolving it in the solvent.
It is desired that the total solid content of the component and the component (B) is about 0.1 to 20%, preferably 0.2 to 10%. In addition, since heat is generated when a catalyst is added to the components (A) and (B), the temperature of the reaction system is usually adjusted to about 5 to 60 ° C, preferably about 10 to 20 ° C, and hydrolysis or polycondensation is performed. It is preferable to adjust the speed of.

In the present invention, the component (B) is hydrolyzed,
Although water can be used for polycondensation, it is desirable to use as little water as possible in order to maintain the transparency and stability of the sol. After the addition of the acid catalyst to form a uniform transparent precursor sol, the sol may be diluted with an appropriate amount of water.

In the present invention, a lower alcohol may be used as a common medium, if necessary, in order to maintain the precursor sol composition as a uniform and transparent solution. Examples of such lower alcohols include methanol, ethanol, n-propanol, isopropanol and the like, and of these, methanol and ethanol are preferable. When the catalyst is added, methanol or ethanol is by-produced from the alkoxysilane during the condensation reaction, but the by-product alcohol often causes the reaction system to become uniform and transparent. In this case, the lower alcohol is not always necessary. When the lower alcohol is used, the amount to be added cannot be unconditionally determined because it depends on the components (A) and (B), the types of acid catalysts and their amounts, and the amount of water used. Is usually less than 40%, preferably 20% by weight of the total solid content of the components (A) and (B).
It is preferably less than%.

In the production of the organic / inorganic hybrid body by the production method of the present invention, the mixing ratio of the component (A) which is an organic polymer component and the component (B) which is an inorganic glass component is usually a solid content conversion weight ratio. Is (A) component / (B) component = 2/1 to 1/8, preferably 1 / 1.5 to 1/5. If the amount of the component (B) exceeds eight times the amount of the component (A), the coating film may be cracked or the adhesiveness may be significantly reduced. Further, when the amount of the component (A) exceeds twice the amount of the component (B), it becomes difficult to form a uniform and transparent precursor sol, and the coating film obtained at the time of natural drying becomes a soft wax-like substance, which is transparent. Properties and film formability are low.

There is no particular limitation on the temperature and time when the above-mentioned components (A), (B) and other components are mixed. That is, it may be appropriately determined so that the obtained precursor sol composition becomes a uniform and transparent solution, and usually about 5 to 60 ° C. for about 10 minutes to 2 hours.

According to the production method of the present invention, the precursor sol composition (homogeneous sol solution) thus formed is coated (coated) on various substrates such as glass plates, and then naturally dried to obtain a hard adhesive having good adhesion. A film is formed, but depending on the mixing ratio of each component and the preparation conditions, the methylol group derived from the component (A) may remain in the obtained hybrid body and the water resistance may not be sufficient. In this case, the naturally dried coating film is further added at a temperature of about 100 to 170 ° C., preferably 130 to 150 ° C. for about 3 to 30 minutes, preferably
By heating for 5 to 15 minutes, the hardness is remarkably increased and a higher performance coating film with improved water resistance is formed.

In order to apply the precursor sol composition to the substrate, a usual method such as a coating method using a spray gun, a brush, a roller, a doctor knife or the like, or a dip coating method can be adopted. The thickness of the coating film thus obtained is not particularly limited, but the thickness after drying is usually preferably about 5 to 500 μm. A base material may be impregnated with the precursor sol composition by a usual method other than the coating method. That is, for example, a base material such as gypsum or wood may be impregnated and cured, or wood powder or paper may be impregnated and dried, and then heat-cured under pressure.

The precursor sol composition of the present invention can maintain the state of a uniform and transparent sol solution for a long period of time, and the sol solution is allowed to spontaneously dry after coating and the gelation proceeds rapidly with the evaporation of alcohol. As a result, a transparent hybrid body having good adhesion and high hardness is formed.

The precursor sol composition has good wettability and adhesion to various materials such as plastic, glass, wood, metal, cloth and paper, and can be widely applied to various uses and use conditions. In particular, it can be suitably used as a high-performance lacquer that is dried at room temperature. Further, as described above, it is possible to further improve hardness and water resistance by heating the naturally dried hybrid body, and the heat treated hybrid body has excellent scratch resistance and abrasion resistance for protecting plastic molded articles. It is suitable for use as a coating film for protecting wood and metal surfaces, including the above coating compositions.

It is difficult to elucidate in detail the reason why the precursor sol composition of the present invention becomes a uniform and transparent solution, the reaction at the time of formation of the hybrid body and the reason why the obtained hybrid body has high performance. However, when the precursor sol composition is coated on a substrate and then naturally dried, the alkoxy group site of the hydrolyzable alkoxysilane is hydrolyzed by the action of water in the air, and at the same time polycondensation proceeds between the sites. It is considered that a high-hardness hybrid body is formed because the silanol group on the surface of the silica particle forms a hydrogen bond or an ether bond with the methylol group of the ketone resin initial condensation product as the silica particle is generated.
The number of silica particles produced is several 10 when observed with an electron microscope.
It is considered that the particles are ultra-fine particles of about angstrom, and the silica particles are uniformly dispersed while taking a three-dimensional crosslinked structure using a ketone resin as a matrix.

Next, the precursor sol composition of the ketone resin / silica glass hybrid body of the present invention and the method for producing the hybrid body will be described more specifically with reference to Production Examples and Examples. It is not limited to.

Production Example 1 116.2 g of acetone and 529.5 g of 37% formaldehyde were charged into a reactor equipped with a stirrer and a heating / cooling device, and 23.2 g of 20% aqueous sodium hydroxide solution was slowly added over about 15 minutes while stirring. Dropped. The temperature in the reaction system during dropping was adjusted to about 60 ° C. After completion of the dropping, the reaction was carried out by keeping the same temperature for 1 hour. The obtained acetone resin initial condensate has a pH of 7.1, a non-volatile content of 36.2%, and a number average molecular weight of 1,500.
It was a colorless and transparent aqueous solution.

Production Example 2 The reaction was carried out in the same manner as in Production Example 1 except that 144.2 g of methyl ethyl ketone was used instead of 116.2 g of acetone, and the pH was 7.2, the nonvolatile content was 22.0%, and the number average molecular weight was 1300. An initial condensation product of methyl ethyl ketone resin, which is a colorless and transparent aqueous solution, was obtained.

Production Example 3 The reaction was carried out in the same manner as in Production Example 1 except that 196.2 g of cyclohexanone was used instead of 116.2 g of acetone, and pH 6.5, nonvolatile content 44.7%, number average molecular weight 1100. An initial condensation product of cyclohexanone resin which is a colorless and transparent aqueous solution was obtained.

Production Example 4 Urea-modified methyl ethyl ketone-acetone co-condensation ketone resin initial condensation product (manufactured by Arakawa Chemical Industry Co., Ltd., trade name "KN
-141 ") was used as it was. The property of this product is pH 7.
4, a colorless transparent aqueous solution having a nonvolatile content of 41.0% and a number average molecular weight of 1200.

Example 1 In an Erlenmeyer flask, 2 g of the acetone resin initial condensate (solid content 0.81 g) of the production example 1 which is the component (A) and 2 g of tetraethoxysilane (hereinafter referred to as TEOS) which is the component (B).
Was charged, and 0.5 g of hydrochloric acid / methanol reagent containing about 10% hydrogen chloride was added as a catalyst with stirring. The temperature of the mixed solution at this time was 20 ° C. After 3 minutes,
The suspended mixed solution became uniformly transparent, and a low-viscosity sol solution was obtained. Then, this sol solution was applied on a glass plate by flow coating to a thickness of about 0.2 mm, and naturally dried to obtain a colorless and transparent coating film. Also,
This naturally dried coating film was heated at 150 ° C. for 5 minutes to prepare a colorless and transparent coating film.

Examples 2 to 4 A sol solution was prepared in the same manner as in Example 1 except that the kind of the component (A) was changed as shown in Table 1.
Then, various coating films were prepared using these sol solutions. All the obtained coating films were colorless and transparent. Each of these naturally dried coating films was heated at 150 ° C. for 5 minutes to prepare a colorless and transparent coating film.

Examples 5 and 6 In Example 1, the acetone resin precondensate and TEOS were used.
Example 1 except that the mixing ratio with and was changed as shown in Table 1.
A sol solution was prepared in the same manner as in 1. and then various coating films were prepared using these sol solutions. All the obtained coating films were colorless and transparent. Each of these naturally dried coating films was heated at 150 ° C. for 5 minutes to prepare a colorless and transparent coating film.

Example 7 In Example 1, instead of TEOS, an initial condensate of tetramethoxysilane (trade name “methyl silicate-5”) was used.
1 ”, manufactured by Mitsubishi Kasei Co., Ltd. was used to prepare a sol solution in the same manner as in Example 1, and then a coating film was prepared using this sol solution. The obtained coating film was colorless and transparent. The coating film by natural drying was heated at 150 ° C. for 5 minutes to prepare a colorless and transparent coating film.

Example 8 In Example 1, p- was used instead of the hydrochloric acid / methanol reagent.
A sol solution was prepared in the same manner as in Example 1 except that a 10% aqueous solution of toluenesulfonic acid was used, and then a coating film was prepared using this sol solution. The obtained coating film was colorless and transparent. The coating film by natural drying was heated at 150 ° C. for 5 minutes to prepare an almost colorless and transparent coating film.

Comparative Examples 1-2 In Example 1, the acetone resin precondensate and TEOS were used.
Example 1 except that the mixing ratio with and was changed as shown in Table 1.
A sol solution was prepared in the same manner as in 1. and then various coating films were prepared using these sol solutions. All the obtained coating films were colorless and transparent. The coating films prepared by natural drying were each heated at 150 ° C. for 5 minutes to prepare coating films, but both had insufficient film-forming properties and some cracks occurred.

Comparative Example 3 Using only the acetone resin precondensate of Production Example 1, this was coated on a glass plate by flow coating to a thickness of about 0.2 mm, and naturally dried to form a colorless and transparent coating film. I got it. In addition, this natural drying coating film
A coating film was prepared by heating at 150 ° C for 5 minutes.
The film forming property was poor.

[0033]

[Table 1]

In Table 1, * indicates methyl silicate
51 is shown.

The performances of the various sol solutions obtained in Examples 1 to 8 and Comparative Examples 1 to 3 and various coating films formed on glass plates prepared from the sol solutions were evaluated by the following methods. .. The results are shown in Table 2.

(1) Leaving stability of sol solution The sol solution thus produced was left to stand at room temperature for 30 days, and its property change (degree of change in transparency, viscosity and color tone) was visually observed. Those with almost no change were evaluated as good, and the others were evaluated as bad.

(2) Properties of coating film (a) Gloss Specular reflectance at 20 degrees was measured according to JIS Z 8741, and was 95%.
The above was regarded as good, and 50% or less was regarded as bad.

(B) Hardness The pencil hardness was measured, and 6H or more was regarded as good and H or less was judged as poor.

(C) Water resistance After being immersed in water at room temperature for 12 hours, the state of the coating film is visually evaluated, and there is no whitening, peeling, blister, and swelling. Δ, x was markedly observed.

(D) Solvent resistance After dipping in tetrahydrofuran at room temperature for 12 hours, the state of the coating film is visually judged, and those free of whitening, peeling, blisters and swelling are regarded as good, and these are noticeable. The thing was bad.

[0041]

[Table 2]

In Table 2, RT is a naturally dried coating film, and 150 is a coating film obtained by heating at 150 ° C.

[0043]

EFFECT OF THE INVENTION The precursor sol composition of the present invention is a uniform and transparent sol composition excellent in leaving stability, and by coating and drying the precursor sol composition, it has high hardness and excellent transparency. Moreover, a ketone resin / silica glass hybrid having good film-forming properties, water resistance, solvent resistance and the like can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Oseto 1-1-9 Tsurumi, Tsurumi-ku, Osaka Arakawa Chemical Industry Co., Ltd.

Claims (6)

[Claims] 1. A ketone resin initial condensate, (B) a hydrolyzable alkoxysilane or a partially hydrolyzed polycondensate thereof, and an acid catalyst, and (A) component and (B).
The ratio of solid content to the components is (A) / (B) = 2/1 to 1 /
8. A precursor sol composition of a ketone resin / silica glass hybrid body, which is a mixture of 2. The precursor sol composition according to claim 1, which contains a lower alcohol and / or water. 3. The precursor sol composition according to claim 1, wherein the acid catalyst is hydrogen halide or a strong organic acid. 4. The precursor sol composition according to claim 1, 2 or 3, wherein the amount of the catalyst used is 0.1 to 20% by weight based on the total solid weight of the components (A) and (B). 5. A method for producing a ketone resin / silica glass hybrid body, which comprises coating or impregnating a base material with the precursor sol composition according to claim 1, 2, 3 or 4, and then drying. 6. The method for producing the hybrid body according to claim 5, wherein the drying is performed at 100 to 170 ° C.