JP5048395B2 - Inorganic organic composite coating composition - Google Patents

Description

  The present invention relates to an inorganic-organic composite coating composition.

  So far, various so-called inorganic-organic composite coating materials including an inorganic material and an organic material have been proposed. As such an inorganic organic composite coating material, for example, a material containing alkoxysilane or a condensate thereof as an inorganic material can be mentioned. Generally, these materials are cured by condensation by heat. However, only by curing with heat, only a coating film with insufficient hardness may be obtained depending on the application.

On the other hand, it is known that a cured product can be obtained by irradiating a silica sol containing silica particles obtained by hydrolysis and / or condensation of a silicon compound and an organic liquid medium containing a (meth) acrylate group by irradiation with radiation. (Patent Document 1). However, even with this technique, a coating film with sufficient hardness may not be obtained.
JP 2005-298226 A

  The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an inorganic-organic composite coating that is curable to both heat and active energy rays and can form a hard film. It is to provide a composition.

  Heretofore, it has not been known to use a substantially completely hydrolyzed condensate of tetraalkoxysilane as an inorganic material for an inorganic / organic composite coating composition. The present inventors can hydrolyze a tetraalkoxysilane condensate substantially completely by using specific reaction conditions, and the obtained hydrolyzate is used as an inorganic material of an inorganic-organic composite coating composition. The present invention has been found to be suitable, and the present invention has been completed.

  That is, the inorganic / organic coating composition of the present invention contains polyhydroxysiloxane substantially free of alkoxy groups and an organic binder containing an active energy ray-curable resin.

  In another aspect, the inorganic / organic composite coating composition of the present invention comprises (A) a tetraalkoxysilane condensate (a-1), a hydrophilic organic solvent (a-2), and a tetraalkoxysilane condensate. A polyhydroxysiloxane solution obtained by mixing water (a-3) having an equivalent (mole) or more of the alkoxy group (mol) and catalyst (a-4), and (B) an active energy ray-curable resin. An organic binder.

  In a preferred embodiment, the polyhydroxysiloxane solution (A) includes a tetraalkoxysilane condensate (a-1), an alkoxysilane compound (a-1 ′) having an organic group in part, a hydrophilic organic solvent ( a-2), water (a-3) equal to or greater than the equivalent (mol) of an alkoxy group contained in the condensate of tetraalkoxysilane and an alkoxysilane compound having an organic group in part, and catalyst (a-4) It is a polyhydroxysiloxane solution obtained by mixing.

  In a preferred embodiment, the alkoxysilane compound (a-1 ′) has a double bond.

  In a preferred embodiment, the hydrophilic organic solvent (a-2) contains a compound having a polymerizable double bond.

  In a preferred embodiment, the active energy ray-curable resin is a resin having a polymerizable double bond or an epoxy group.

  In preferable embodiment, the said inorganic organic composite coating composition further contains a photocuring initiator.

  According to another aspect of the present invention, a coating film is provided. This coating film is formed from the inorganic-organic composite coating composition.

  In a preferred embodiment, the coating film is a coating film that is doubly cured by heat and active energy rays.

  According to another aspect of the present invention, a method for producing a coating film is provided. In this production method, the inorganic organic composite coating composition is applied on the substrate (1), and the inorganic organic composite coating composition applied in the step (1) is double-cured by heat and active energy rays. Including step (2).

  According to the present invention, there is provided an inorganic / organic composite coating composition using polyhydroxysiloxane having substantially no alkoxy group as an inorganic material and using an active energy ray-curable resin as an organic material. According to the inorganic-organic composite coating composition, since the inorganic material can be cured by heat and the organic material can be cured by irradiation with active energy rays, a sufficiently hard coating film can be formed. Furthermore, polyhydroxysiloxane having substantially no alkoxy group is excellent in compatibility with an organic material. Therefore, the inorganic / organic composite coating composition of the present invention can form a coating film (coating film having an excellent balance between film thickness and hardness) that is compatible with the characteristics of the inorganic material and the organic material, and is homogeneous. A dense coating film with high properties can be formed.

  The inorganic / organic composite coating composition of the present invention includes a polyhydroxysiloxane having substantially no alkoxy group and an organic binder containing an active energy ray-curable resin. The polyhydroxysiloxane having substantially no alkoxy group can be obtained, for example, by mixing a tetraalkoxysilane condensate, a hydrophilic organic solvent, a predetermined amount of water, and a catalyst. In addition, for example, polyhydroxysiloxane having substantially no alkoxy group includes a tetraalkoxysilane condensate, an alkoxysilane compound having an organic group in part, a hydrophilic organic solvent, a predetermined amount of water, and a catalyst. It can be obtained by mixing. Therefore, in one embodiment, the inorganic-organic composite coating composition of the present invention comprises (A) a tetraalkoxysilane condensate (a-1), a hydrophilic organic solvent (a-2), a predetermined amount of water (a 3) and a polyhydroxysiloxane solution obtained by mixing the catalyst (a-4), and (B) an organic binder containing an active energy ray-curable resin. In another embodiment, the inorganic / organic composite coating composition of the present invention comprises a tetraalkoxysilane condensate (a-1), an alkoxysilane compound (a-1 ′) having an organic group in part, and a hydrophilic organic solvent. (A-2), a predetermined amount of water (a-3), and a polyhydroxysiloxane solution obtained by mixing the catalyst (a-4), and (B) an organic binder containing an active energy ray-curable resin Including. Hereinafter, the present invention will be described in detail.

a-1. Condensate of tetraalkoxysilane The condensate of tetraalkoxysilane can be obtained by condensing tetraalkoxysilane. The condensate obtained by the above condensation is not usually a single compound, but typically a mixture of compounds having various structures in terms of the degree of condensation, the presence or absence of branching or crosslinking, and the like. Also, commercially available tetraalkoxysilane condensates are basically a mixture although some of the raw materials tetraalkoxysilane are excluded. For this reason, the condensate of tetraalkoxysilane is typically represented by the following formula (1). In addition, following formula (1) has shown the case where the condensate of tetraalkoxysilane is a linear condensate without a branch and bridge | crosslinking.

  In said formula (1), n is 2 or more, 2-50 are preferable and 5-20 are more preferable. When n is 2 or more, an appropriate amount of hydroxysilyl groups can be obtained, so that the intended coating film can be formed. Moreover, when n is 50 or less, the condensate of tetraalkoxysilane can maintain a liquid state, so that the operability is good. The above n is an average value. The degree of condensation of the tetraalkoxysilane condensate can be determined by gel permeation chromatography (GPC).

In the above formula (1), each R ¹ is independently a substituted or unsubstituted linear or branched alkyl group, preferably a substituted or unsubstituted linear or branched group having 1 to 4 carbon atoms. More preferably an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, and still more preferably an unsubstituted alkyl group having 1 to 2 carbon atoms. When R ¹ is the above preferred alkyl group, the hydrolyzability of the condensate of tetraalkoxysilane is improved, so that polyhydroxysiloxane can be obtained efficiently.

Specific examples of R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. Of these, a methyl group, an ethyl group, a propyl group, an isopropyl group, and an n-butyl group are preferable, a methyl group and an ethyl group are more preferable, and a methyl group is more preferable.

  Any appropriate substituent can be used as the substituent that the alkyl group may have. Specific examples include halogen atoms such as chloro and bromo, alkoxy groups such as methoxy, ethoxy and butoxy, cyano groups and dimethylamino groups. When it has such a substituent, it is preferable that the sum total of carbon number of a substituted alkyl group is 1-6. The alkyl group may be substituted with a compound having an alkylene oxide unit. Examples of the type of alkylene oxide unit include ethylene oxide, propylene oxide, and tetramethylene oxide.

  Therefore, examples of the tetraalkoxysilane condensate include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, Or the condensate of tetra- tert- butoxysilane is mentioned. Especially, the condensate of tetramethoxysilane and the condensate of tetraethoxysilane are preferable, and the condensate of tetramethoxysilane is more preferable. The condensates of tetraalkoxysilane may contain the same or different alkyl groups. In the present invention, only one tetraalkoxysilane condensate may be used, or two or more condensates may be used in combination.

  The condensate of the tetraalkoxysilane may contain a monomeric tetraalkoxysilane. In this case, the tetraalkoxysilane condensate and the monomer tetraalkoxysilane may contain the same or different alkyl groups. Specific examples of the case where the alkyl groups contained are different include the case of containing a condensate of tetramethoxysilane and the monomer tetraethoxysilane. In addition, it is preferable that the compounding quantity of the monomer tetraalkoxysilane is 100 mass parts or less with respect to 100 mass parts of condensates of tetraalkoxysilane.

  The number of alkoxy groups contained in the tetraalkoxysilane condensate is typically 6 or more, preferably 6 to 102, and more preferably 12 to 42. When the number of alkoxy groups is in the preferred range, an appropriate amount of hydroxysilyl groups can be obtained, so that the intended coating film can be easily formed. As described above, since the condensate of tetraalkoxysilane can include those having various degrees of condensation, the number of the alkoxy groups is an average value thereof. The number of alkoxy groups contained in the condensate of tetraalkoxysilane can be determined from the degree of condensation. Moreover, when the condensate of the said tetraalkoxysilane has a substituent, it is preferable that the number is below half of the number of alkoxy groups.

  The condensate of the tetraalkoxysilane can be prepared by hydrolytic condensation of any appropriate tetraalkoxysilane. Commercial products may also be used. Examples of the commercially available products include, for example, trade names “MKC silicate MS51”, “MKC silicate MS56”, “MKC silicate MS57”, “MKC silicate MS60” (all of which are condensates of tetramethoxysilane), Colcoat, manufactured by Mitsubishi Chemical Corporation. And trade names “Ethyl silicate 40” and “Ethyl silicate 48” (both are condensates of tetraethoxysilane). Examples of commercially available condensates of tetraalkoxysilanes containing different alkyl groups include, for example, trade names “MKC silicate MS56B15”, “MKC silicate MS56B30”, “MKC silicate MS58B15”, “MKC silicate MS58B15”, “ Examples thereof include “MKC silicate MS56I30”, “MKC silicate MS56F20”, manufactured by Colcoat Co., Ltd., and trade name “EMS-485”.

a-1 ′. An alkoxysilane compound having an organic group in part As the alkoxysilane compound having an organic group in part, any appropriate alkoxysilane compound can be used as long as it has one or more Si-C bonds. By using together the condensate of tetraalkoxysilane and the alkoxysilane compound having an organic group in part, it is possible to suppress excessive condensation reaction between the hydrolyzates of the alkoxy group-containing components and to obtain polyhydroxy Good compatibility between the siloxane solution and the organic binder can be ensured. Furthermore, when the alkoxysilane compound having an organic group in part has a double bond, the hardness of the resulting coating film can be further increased by crosslinking them.

  As an organic group, Preferably it is C1-C21, More preferably, a 1-10 linear or branched alkyl group etc. are mentioned. When the organic group is a long-chain alkyl group having 4 or more carbon atoms, it is possible to improve the stain resistance (oil marker contamination, fingerprint adhesion, etc.) of the resulting coating film. The alkyl group may have a mercapto group, an epoxy group, an amino group, a vinyl group, an ether bond, an ester bond, or the like.

  Examples of the alkoxysilane compound having a part of the organic group include a silane coupling agent, preferably a silane coupling agent having one or two Si—C bonds. Specific examples include, for example, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, n-decyltrimethoxysilane, n-hexadecyltri. Methoxysilane, 1,6-bis (trimethoxysilyl) hexane, γ-ureidopropyltriethoxysilane, γ-dibutylaminopropyltrimethoxysilane, nonafluorobutylethyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropylto Methoxysilane, γ-chloropropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltrimethoxysilane, dimethyldimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ -(Meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane and the like can be mentioned.

  As the usage-amount of the alkoxysilane compound (a-1 ') which has the said organic group in part, it is a mixed ratio [(a-1') / (a-1) with the condensate (a-1) of tetraalkoxysilane. ): Mass of solid content] is preferably 1/99 to 70/30, more preferably 5/95 to 50/50. By using within this range, a coating film having a desired hardness can be obtained, sufficient compatibility with an organic binder can be ensured, and an effect of suppressing a rapid condensation reaction of a tetraalkoxysilane condensate can be obtained. be able to.

a-2. Hydrophilic organic solvent The hydrophilic organic solvent includes an alkoxysilane compound having in part a condensate of the tetraalkoxysilane and an organic group that is optionally used (in this specification, these components are referred to as “alkoxy group-containing components”). As long as it can be dissolved to such an extent that the hydrolysis reaction proceeds, any appropriate one can be used. The hydrophilic organic solvent preferably contains a compound having a polymerizable double bond. This is because the hardness of the resulting coating film can be further increased. In one embodiment, the hydrophilic organic solvent may be composed only of a compound having a polymerizable double bond.

Examples of the hydrophilic organic solvent include alcohols, glycols, glycol ethers or esters, and ketones. For example, methanol, ethanol, propanol, isopropyl alcohol, R ₂ —O— (CH ₂ CH (R ₃ ) O) _m —H (wherein R ₂ is an alkyl group having 1 to 4 carbon atoms, and R ₃ is H or CH ₃ , m is an integer of 1 to 3), CH ₃ —O— (CH ₂ CH (R ₄ ) O) ₁ —CH ₃ (wherein R ₄ is H or CH ₃ . Yes, l is 1 or 2.), acetone, methyl ethyl ketone, diacetone alcohol, 3-methoxy-3-methyl-1-butanol and the like can be preferably used. In the present invention, only one type of hydrophilic organic solvent may be used, or two or more types may be used in combination.

  Examples of the compound having a polymerizable double bond include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene oxide-modified (meth) acrylate, hydroxy Hydroxyl group-containing monomers such as alkyl vinyl ether, hydroxystyrene, allyl alcohol, etc .; (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N, N′-dimethylacrylamide, dimethylamino Amide group-containing monomers such as propyl (meth) acrylamide, N-vinylpyrrolidone and N-acryloylmorpholine; Carboxyl group-containing monomers such as acrylic acid and methacrylic acid; 2-hydroxyethyl ( Phosphoric acid monoester of acrylate, phosphoric acid monoester of 2-hydroxypropyl (meth) acrylate, mono (meth) acryloyl acid phosphate (for example, Johoku Chemical Co., Ltd., trade name “JAMP-514”), etc. Non-acrylic monomers such as acid group-containing monomers; epoxy group-containing monomers such as allyl glycidyl ether; and polyfunctional unsaturated monomers such as polyethylene oxide-modified di (meth) acrylate. These monomers may be used alone or in combination of two or more.

  The content of the compound having a polymerizable double bond in the hydrophilic organic solvent is preferably 20 to 100% by mass, more preferably 50 to 100% by mass.

Solubility in water of the hydrophilic organic solvent as (20 ° C.) is preferably 5g / 100gH ₂ O or more, more preferably 20g / 100gH ₂ O or more, still more preferably 100g / 100gH ₂ O or more. By using a hydrophilic organic solvent having such solubility, a system containing the hydrophilic organic solvent, water, and an alkoxy group-containing component that is not sufficiently soluble in water can be made uniform. As a result, the hydrolysis reaction of the alkoxy group-containing component can be efficiently advanced.

  The usage-amount of the said hydrophilic organic solvent should just be more than the quantity which can melt | dissolve an alkoxy-group containing component. As the usage-amount of the said hydrophilic organic solvent, the mixing ratio (mass part) of the alkoxy-group containing component {(a-1) + (a-1 ')} and the hydrophilic organic solvent (a-2) [{(a -1) + (a-1 ′)} / (a-2)] is more than 1, it is advantageous for lowering the VOC of the inorganic / organic composite coating composition, and mixing with an aqueous organic binder is effective. It has the advantage of being easy. On the other hand, the amount of the hydrophilic organic solvent used is the mixing ratio (parts by mass) of the alkoxy group-containing component {(a-1) + (a-1 ′)} and the hydrophilic organic solvent (a-2) [{ When (a-1) + (a-1 ′)} / (a-2)] is 1 or less, there is an advantage that mixing with a solvent-type organic binder becomes easy.

a-3. Water Any appropriate water can be used as the water. For example, tap water, ion exchange water, and pure water are preferably used.

  The usage-amount of the said water is more than the equivalent (mol) of the alkoxy group which an alkoxy group containing component has. By using this amount of water, the hydrolysis reaction of the alkoxy group-containing component can sufficiently proceed. As a result, polyhydroxysiloxane substantially free of alkoxy groups can be obtained.

  The amount of water used is preferably 20 times equivalent (mole) or less, more preferably 5 times equivalent (mole) or less of the alkoxy group of the alkoxy group-containing component. In one embodiment, when a solvent-type organic binder is used, the amount of water used is preferably 2 equivalents (moles) or less, more preferably 1 equivalent, of the alkoxy groups of the alkoxy group-containing component. (Mol). By using this amount of water, precipitation of the alkoxy group-containing component or the hydrolyzate thereof during the hydrolysis reaction can be prevented, and the storage stability of the resulting polyhydroxysiloxane can be improved.

a-4. Catalyst Any appropriate catalyst can be used as the catalyst as long as it has a catalytic action on the hydrolysis reaction of the alkoxy group of the alkoxy group-containing component. Specific examples include inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid; organic acids such as acetic acid and paratoluenesulfonic acid; metal alkoxides and chelate compounds such as titanium, aluminum and zirconium. This is because the catalytic action is moderate, so that the condensation of the produced polyhydroxysiloxane hardly proceeds. Among these, an aluminum catalyst is preferably used. Examples of the aluminum catalyst include aluminum trisacetylacetonate, aluminum monoacetylacetonate bis (ethylacetoacetate), and ethylacetoacetate aluminum diisopropylate.

  The amount of the catalyst used may be at least an amount that exhibits a catalytic action for the hydrolysis reaction of the alkoxy group of the alkoxy group-containing component. Specifically, the amount used is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the alkoxy group-containing component.

A. Polyhydroxysiloxane Solution The polyhydroxysiloxane solution can be obtained, for example, by mixing the tetraalkoxysilane condensate, a hydrophilic organic solvent, water, and a catalyst. At that time, if necessary, an alkoxysilane compound having an organic group in part is further added and mixed. Thereby, excessive condensation reaction of the condensate of tetraalkoxysilane can be suppressed, and good compatibility between the obtained polyhydroxysiloxane solution and the organic binder can be ensured.

  Any appropriate method is used as the mixing method. Preferably, a tetraalkoxysilane condensate, a catalyst, a hydrophilic organic solvent, and, if necessary, an alkoxysilane compound partially containing an organic group are mixed, and then water is added to the resulting mixture. It is done. By mixing in such a manner, white turbidity, formation of precipitates, or gelation of the obtained mixed solution can be prevented. Water is preferably added little by little, and more preferably added dropwise. In addition, when a precipitate etc. produce | generate as a by-product during mixing, it can be used, after removing by arbitrary appropriate methods, such as filtration, and making it a state without turbidity visually.

  In the above mixed solution, a hydrolysis reaction of the condensate of tetraalkoxysilane (when an alkoxysilane compound having an organic group in part is mixed, the hydrolysis reaction) proceeds. Siloxane is produced. Examples of suitable conditions for the hydrolysis reaction include the following conditions. That is, the reaction temperature is preferably 10 to 100 ° C, more preferably 20 to 80 ° C, and still more preferably 40 to 60 ° C. The reaction time is preferably 0.5 to 10 hours, more preferably 1 to 8 hours, and further preferably 2 to 6 hours. By performing the hydrolysis reaction under the conditions, the hydrolysis reaction can be sufficiently advanced to produce the desired polyhydroxysiloxane, and the condensation of the produced polyhydroxysiloxanes can be suppressed.

  The hydrolysis reaction is preferably terminated after substantially all the alkoxy groups contained in the alkoxy group-containing component in the mixed solution are hydrolyzed. In this case, the produced polyhydroxysiloxane has substantially no alkoxy group. “Substantially all of the alkoxy groups have been hydrolyzed” and “the polyhydroxysiloxane has substantially no alkoxy groups” can be, for example, nuclear magnetic resonance analysis (H-NMR) and / or infrared It can be confirmed by spectroscopic analysis (IR) that no peak based on an alkoxy group is observed. A polyhydroxysiloxane that has substantially no alkoxy group and can be combined with an organic material has not been able to be obtained in a practical state in the past. It is obtained.

  In addition, the polyhydroxysiloxane is typically in a solution as shown by a hydrolyzate of tetraalkoxysilane and / or its condensate described in JP-A-9-165450 and WO95 / 17349. In addition, no microdomains of 3 nm or more are formed. That is, a polyhydroxysiloxane solution can be obtained as a uniform solution. The presence or absence of particulates or microdomains of 3 nm or more can be confirmed by observation with a transmission electron microscope (TEM), a laser light scattering measurement device, or a small-angle X-ray scattering device.

In the polyhydroxysiloxane solution obtained as described above, it is preferable that condensation between the hydrolyzate of the alkoxy group-containing components, especially among the polyhydroxysiloxanes, does not substantially occur. Therefore, in one preferred embodiment, the average condensation degree n ₁ of the alkoxy group-containing component subjected to the hydrolysis reaction and the average condensation degree n _{2 of the} resulting hydrolyzate of the alkoxy group-containing component are preferably 1 ≦ n. ₂ / n ₁ ≦ 3. The average degree of condensation of the hydrolyzate of the alkoxy group-containing component can be determined by GPC analysis.

  The polyhydroxysiloxane solution contains at least polyhydroxysiloxane, a hydrophilic organic solvent, water, a catalyst, and an alcohol generated by hydrolysis of an alkoxy group. The solid content concentration in the solution is typically about 5 to 40% by mass. The solid content concentration can be adjusted to a desired value (for example, 3 to 30% by mass) by further adding a hydrophilic organic solvent and / or water to the solution. The hydrophilic organic solvent and water to be added can be appropriately selected from those described in the above items a-2 and a-3 depending on the type of the organic binder. Specifically, water is preferably added when an aqueous organic binder is used, and a hydrophilic organic solvent is preferably added when a solvent-type organic binder is used.

Typically, the polyhydroxysiloxane solution cannot form a coating film alone, or even if formed, the coating film has a thickness of 0.5 μm or less. Thus, by using a polyhydroxysiloxane solution that is difficult to form a coating film having a sufficient thickness by itself with an organic binder described later, for example, a coating film having a film thickness of 1 μm or more, preferably 5 μm or more is formed. can do. In the present specification, unless otherwise specified, “form a coating film” is applied to a tin plate with a predetermined bar coater, dried at 80 ° C. for 1 minute, and then 360 nm with a mercury lamp or a metal halide lamp. This means that a continuous film of 5 cm × 5 cm or more is formed after irradiating 100 mJ / cm ² of ultraviolet light with a light quantity of 5 nm.

B. Organic Binder The organic binder used in the present invention contains an active energy ray curable resin. As a result, the resulting coating film can be cured with active energy rays, so that there are two types of curing: curing by condensation reaction of polyhydroxysiloxane by heat and curing by polymerization reaction of organic binder by irradiation of active energy rays. A matrix is formed, and a harder coating film can be obtained. As a result, not only is the balance between the film thickness and the hardness excellent, but a dense coating film with high homogeneity between the inorganic material (polyhydroxysiloxane) and the organic material (organic binder) can be formed.

  As the active energy ray-curable resin, any appropriate one can be used depending on the purpose. Preferably, a resin containing a polymerizable double bond or an epoxy group is used. The resin containing a polymerizable double bond is preferably a compound having two or more α, β-unsaturated carbonyl groups per molecule. The α, β-unsaturated carbonyl group is a functional group having a double bond between the α carbon and β carbon with respect to the carbonyl group, and examples thereof include a methacrylate group, an acrylate group, a maleate group, and a fumarate group. it can. When it has only one α, β-unsaturated carbonyl group, it may not exhibit sufficient active energy ray curability. The α, β-unsaturated carbonyl group is preferably 10 or less per molecule, more preferably 6 or less.

  Examples of the resin containing a polymerizable double bond include (meth) acrylic acid ester of polyol, unsaturated polyester polymer and epoxy polymer containing α, β-unsaturated dicarboxylic acid such as fumaric acid and maleic acid as an acid component. (Meth) acrylic acid ester, (meth) acryloyl group-containing urethane compound, α, β-unsaturated carbonyl group-containing acrylic polymer, (meth) acryloyl group-containing polyether polymer, (meth) acryloyl group-containing silicone oligomer, etc. Can be mentioned. Among them, a (meth) acrylic acid ester of a polyol is preferable because of high reactivity, weather resistance, compatibility, and high gloss.

  Specific examples of (meth) acrylic acid ester of polyol include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide modified tri (meth) acrylate, Trimethylolpropane propylene oxide modified tri (meth) acrylate, glycerin tri (meth) acrylate, glycerin ethylene oxide modified tri (meth) acrylate, glycerin B pyrene-modified tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate. Moreover, the acrylic monomers used for producing the acrylic polymer can be used in combination with the resin.

  The molecular weight (double bond equivalent) per double bond in the resin containing a polymerizable double bond is preferably 50 to 1500, more preferably 70 to 1000. When the double bond equivalent is less than 50, an unreacted (meth) acrylate group remains in the resulting coating film, and the weather resistance of the coating film decreases, or the resulting coating film becomes hard and brittle. There is a case. Moreover, when it exceeds 1500, the crosslinking density of the coating film obtained will become small and the physical property and performance of a coating film may fall.

  Examples of the resin containing an epoxy group include a bisphenol type epoxy resin and an alicyclic epoxy resin. Specifically, bisphenol A type epoxy resin, bisphenol A type epoxy resin, alkyl substituted bisphenol A type epoxy resin, bisphenol F type epoxy resin, alkyl substituted bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol A type An epoxy resin etc. are mentioned. Examples of the alicyclic epoxy resin include 4-vinylcyclohexene monooxide, vinylcyclohexene dioxide, methylated vinylcyclohexene dioxide, (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexyl carboxylate, and bis. -(3,4-epoxycyclohexyl) adipate, bis- (3,4-epoxycyclohexylmethylene) adipate, bis- (2,3-epoxycyclopentyl) ether, (2,3-epoxy-6-methylcyclohexylmethyl) adipate , Dicyclopentadiene dioxide and the like. Other than these, polyfunctional alicyclic epoxy resins, trifunctional, and tetrafunctional alicyclic epoxy resins can also be used.

  The number average molecular weight (Mn) of the active energy ray-curable resin before curing is preferably 200 to 5000, more preferably 250 to 3000. When the number average molecular weight (Mn) is less than 200, the solvent resistance, water resistance and weather resistance of the coating film are reduced due to volatilization at the time of heat curing, decrease in the hardness of the coating film, and decrease in the curability of the paint. There is. When the number average molecular weight (Mn) exceeds 5000, the viscosity of the active energy ray-curable resin itself becomes high, and the content of the solution in the diluted paint at the time of application may become large. In addition, in this specification, a number average molecular weight (Mn) is a number average molecular weight of polystyrene conversion measured by GPC (gel permeation chromatography).

  The content of the active energy ray-curable resin in the organic binder is preferably 30 to 100 parts by mass, and more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the total resin solid content in the organic binder. The organic binder may contain any appropriate other resin other than the active energy ray-curable resin depending on the purpose.

C. Photocuring Initiator The inorganic / organic composite coating composition of the present invention preferably further comprises a photocuring initiator. Any appropriate one can be used as the photocuring initiator. Specific examples include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin propyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone Acetophenones such as 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1,2-benzyl-2-dimethylamino-1- (4-morpho Aminoacetophenones such as linophenyl) -butanone-1, N, N-dimethylaminoacetophenone; annes such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 1-chloroanthraquinone Laquinones; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, 4, Examples thereof include benzophenones such as 4′-bisdiethylaminobenzophenone or xanthones; 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  As content of a photocuring initiator, it can set suitably according to the ratio of thermosetting and active energy ray hardening. The content of the photocuring initiator is generally 0.1 to 30 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the active energy ray-curable resin. .

D. Other Components The inorganic / organic composite coating composition of the present invention may further contain any appropriate other component. Examples of the other components include a silicone compound having an alkoxy group, a sensitizer, a pigment, a surface conditioner, an antifoaming agent, a plasticizer, a film-forming aid, an ultraviolet absorber, and an antioxidant.

  When an organic binder containing a polymerizable double bond or an epoxy group is used, the inorganic organic composite coating composition of the present invention further includes a silicone compound having an alkoxy group, thereby reducing the crosslinking density of the resulting coating film. Can be increased. As a result, a denser coating film can be formed.

E. Manufacturing method of inorganic organic composite coating composition The manufacturing method of the inorganic organic composite coating composition of this invention can employ | adopt arbitrary appropriate methods. For example, a method such as mixing the above-described polyhydroxysiloxane solution and compounding components such as an organic binder using a stirring means well known to those skilled in the art, such as a disper, may be mentioned.

  The blending ratio [(A) / (B): solid content (mass)] of (A) polyhydroxysiloxane solution and (B) organic binder is preferably 1/9 to 9/1, more preferably 2. / 8 to 8/2, more preferably 3/7 to 7/3. An inorganic / organic composite coating composition of the present invention comprising (A) a polyhydroxysiloxane solution and (B) an organic binder at a blending ratio [(A) / (B): solid content (mass)] of 1/9 or more. The object can form a coating film having sufficient hardness. In addition, the inorganic / organic composite of the present invention includes a (A) polyhydroxysiloxane solution and (B) an organic binder in a blending ratio [(A) / (B): solid content (mass)] of 9/1 or less. The coating composition can form a coating film having a sufficient film thickness.

F. Coating film A coating film is formed by applying the inorganic-organic composite coating composition of the present invention on any appropriate substrate. Examples of the coating method include a bar coater method and a spray method. The coating film of the present invention can be preferably 1 μm or more, more preferably 5 μm or more. The dry film thickness of the coating film can be set to any appropriate value depending on the application.

  The obtained coating film may be cured by heating. By curing by heating, the physical properties and various performances of the coating film can be improved. The heating temperature can be appropriately set according to the type of the inorganic / organic composite coating composition. In general, it is preferably set to 40 to 180 ° C. The heating time can be arbitrarily set according to the heating temperature.

The obtained coating film may be subjected to active energy ray curing (for example, electron beam curing, ultraviolet curing, photocuring). By curing the active energy ray, the physical properties and various performances of the coating film can be improved. The energy ray curing conditions can be appropriately set according to the type of the inorganic / organic composite coating composition. For example, ultraviolet rays may be irradiated with a mercury lamp or a metal halide lamp so that the irradiation light quantity at a wavelength of 360 nm is preferably 0.1 to 5 J / cm ² , more preferably 0.1 to 3 J / cm ² .

  Further, the obtained coating film may be double-cured by thermal curing and active energy ray curing. At that time, active energy ray curing may be performed after heat curing, heat curing may be performed after active energy ray curing, or heat curing and active energy ray curing may be performed simultaneously. By double curing, the crosslink density is further improved, and a dense coating film in which the inorganic material and the organic material are homogenized can be formed. The double-cured coating film has a hardness (pencil hardness) of, for example, F or more, preferably H or more.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. Unless otherwise specified, parts and% in the examples are based on mass.

The measurement conditions for each measurement performed in the examples are shown below.
<Confirmation of presence or absence of alkoxy group>
IR analysis: A peak based on C—H stretching of the alkoxy group (in the case of SiOMe, around 2846 to 2849 cm ⁻¹ ) was observed.
H-NMR analysis: A signal based on hydrogen contained in the alkoxy group (in the case of SiOMe, around 3.51 to 3.65 ppm) was observed.
When the peak or signal based on the alkoxy group was not observed, it was evaluated as “No”, and when it was observed, it was evaluated as “Yes”.

<Measurement of average degree of condensation>
The average degree of condensation n ₁ of the alkoxy group-containing component was calculated from the molecular weight (polystyrene conversion) obtained by gel permeation chromatography (GPC) analysis, assuming that the molecule was not branched. GPC analysis was performed with the following apparatus, instrument, and measurement conditions.
・ Analyzer: Tosoh HLC-8220
・ Eluent: Chloroform ・ Flow rate: 0.6 mL / min ・ Detector: RI
-Column temperature: 40 ° C
・ Injection volume: 20μL

The average degree of condensation n ₂ of hydrolyzate of the alkoxy group-containing component, the molecular weight obtained by GPC analysis of (in terms of polyethylene glycol), was calculated that there is no branch in the molecule. GPC analysis was performed with the following apparatus, instrument, and measurement conditions.
・ Analyzer: Tosoh HLC-8220
・ Eluent: methanol containing 10 mM lithium bromide ・ Flow rate: 0.6 mL / min ・ Detector: RI
-Column temperature: 40 ° C
・ Injection volume: 20μL

<Measurement of solid content concentration>
After measuring the weight of the sample (about 1 g), the sample was dried in an oven at 140 ° C. for 10 minutes. Next, the weight of the dried sample was measured. A value obtained by dividing the weight of the sample after drying by the weight of the sample before drying and multiplying by 100 was defined as the solid content concentration (%).

<Measurement of coating film thickness>
The film thickness of the coating film on the tin plate was measured using an electromagnetic film thickness meter (LE-300J, manufactured by Kett Science Laboratory). The film thickness of the coating film on the PET film and the glass plate was measured using a coolant proof micrometer (manufactured by Mitutoyo Corporation). The film thickness of the coating film on the nonmagnetic metal was measured using an eddy current film thickness meter (LH-300J, manufactured by Kett Science Laboratory).

<Measurement of coating film hardness (pencil hardness)>
It measured based on JIS-K-5600-5-4.

<Measurement of oily marker contamination of coating film>
On the prepared coating film, letters were written with an oil-based marker (trade name “Mckey extra fine (black)” manufactured by Zebra Co., Ltd.), and the ink remaining after lightly wiping with a cloth was visually evaluated.

[Preparation Examples 1 to 18]
In the formulation shown in Table 1, a tetraalkoxysilane condensate (a-1), an alkoxysilane compound (a-1 ′) having an organic group in part, a hydrophilic organic solvent (a-2), Water (a-3) and catalyst (a-4) were mixed and reacted to obtain polyhydroxysiloxane solutions 1 to 18. In addition, reaction conditions 1-3 in Table 1 are as follows, respectively.

<Reaction condition 1>
A tetraalkoxysilane condensate, a catalyst, and a hydrophilic organic solvent were added to the reaction vessel and mixed at 20 ° C. While maintaining the obtained mixture at 20 ° C. and stirring, water was further added dropwise to the reaction vessel over 20 minutes. After completion of the dropwise addition, the resulting mixture was stirred at room temperature (about 20 ° C.) for 40 minutes, then heated to 80 ° C. and stirred for 3 hours.

<Reaction condition 2>
A tetraalkoxysilane condensate, a catalyst, and a hydrophilic organic solvent were added to the reaction vessel and mixed at room temperature. While stirring the resulting mixture at room temperature, water was further added dropwise to the reaction vessel over 10 minutes. After completion of dropping, the resulting mixture was stirred at room temperature for 1 hour, then heated to 40 ° C. and stirred for 3 hours.

<Reaction condition 3>
A tetraalkoxysilane condensate, a catalyst, and a hydrophilic organic solvent were added to the reaction vessel and mixed at 20 ° C. While maintaining the obtained mixture at 20 ° C. and stirring, water was further added dropwise to the reaction vessel over 20 minutes. After completion of the dropwise addition, the resulting mixture was stirred at room temperature for 40 minutes, then heated to 40 ° C. and stirred for 3 hours.

When the polyhydroxysiloxane solutions 1 to 18 obtained in Preparation Examples 1 to 18 were observed by TEM, fine particles having an average particle diameter of about 5 nm were observed in the polyhydroxysiloxane solution 2. In all other polyhydroxysiloxane solutions, formation of particles and microdomains of 3 nm or more was not observed. In addition, for the polyhydroxy siloxane solution 1 to 18, appearance (visual), presence or absence of an alkoxy group, an average degree of condensation ratio _(n 2 _{/ n} 1), was investigated solids concentration. The results are summarized in Table 1.

[Preparation Example a]
(Preparation of organic binder (a))
Acrylic emulsion which is a water dispersible resin (methyl methacrylate / n-butyl acrylate / acrylic acid = 50/49/1 (solid content mass ratio), average particle size: 100 nm, pH: 9.0, neutralizer: aqueous ammonia ) As an organic binder (a).

[Preparation Example b]
(Preparation of organic binder (b))
An acrylic polyol (solid content: 60%, hydroxyl value: 140, acid value: 114, glass transition temperature (Tg): 50 ° C.) was used as the organic binder (b).

[Preparation Example c]
(Preparation of organic binder (c))
An organic binder (c) was obtained by mixing 100 parts of pentaerythritol triacrylate having a polymerizable double bond and 10 parts of a photocuring initiator benzyl dimethyl ketal.

The solid content concentration of the organic binders (a) to (c) and the dry film thickness formed with the organic binder alone 5 μm (after drying at 80 ° C. for 1 minute and 1.9 J / cm ² after the drying treatment) Table 2 summarizes the pencil hardness of the coating film when irradiated with UV light.

[Examples 1-11, Comparative Examples 1-3, Reference Examples 1-2]
An inorganic / organic composite coating composition was obtained by thoroughly mixing the polyhydroxysiloxane solution obtained above and the organic binder at the blending ratio shown in Table 3. Next, the obtained inorganic / organic composite coating composition was coated under the coating conditions shown in Table 3 to obtain an inorganic / organic composite coating film. About the obtained inorganic organic composite coating film | membrane, the external appearance (visual observation), pencil hardness, and the dry film thickness were investigated. The results are shown in Table 4. As shown in Table 4, the inorganic-organic composite coating film obtained in Comparative Example 1 was cloudy. Moreover, the crack generate | occur | produced seven days after coating.

[Comparative Example 4]
To a solution obtained by dissolving 0.3 part of sodium dodecylbenzenesulfonate in 80 parts of ion-exchanged water, polymethoxysiloxane (trade name “MS51” manufactured by Mitsubishi Chemical Corporation) and a condensate of tetramethoxysilane (condensation degree: 5 ) SiO ₂ content: 51%) When 29 parts were added and stirred at room temperature for 4 hours, the mixed solution gelled. As a result, it was not possible to obtain polyhydroxysiloxane that can be used as an inorganic material for the inorganic / organic composite coating composition of the present invention.

[Comparative Example 5]
The polyhydroxysiloxane solution 1 obtained in Preparation Example 1 was coated on a PET film (trade name “Cosmo Shine A4100” manufactured by Toyobo Co., Ltd.) with a # 8 bar coater and dried at 80 ° C. for 1 minute. Subsequently, when the cross section of the PET film was observed with TEM, the thickness of the coating film was 200 nm. Further, when the polyhydroxysiloxane solution 1 was applied to a tin plate with a # 20 bar coater and dried at 100 ° C. for 10 minutes, the coating layer became small strips and peeled off from the tin plate, and a coating film was obtained. There wasn't.

  The polyhydroxysiloxane solution used as an inorganic material in the present invention cannot form a coating film having a sufficient film thickness by itself (see Comparative Example 5). However, since the polyhydroxysiloxane solution is excellent in compatibility with an organic material, it is used in combination with an organic material, so that a coating film excellent in the balance between film thickness and hardness and excellent in transparency is used. (See Examples 1 to 11 and Comparative Example 1). Furthermore, since the inorganic-organic composite coating composition of the present invention employs an active energy ray-curable resin as the organic material, it is cured by a polyhydroxysiloxane condensation reaction by heat and an organic binder by active energy ray irradiation. Two types of matrices consisting of curing by the polymerization reaction are formed, and a harder coating film can be obtained (see Examples 1 and 3 and Reference Examples 1 and 2).

  The inorganic / organic composite coating composition of the present invention can be suitably used in the field of paints because it balances the properties of an inorganic material and the properties of an organic material.

Claims (10)

(A) a tetraalkoxysilane condensate (a-1), a hydrophilic organic solvent (a-2), water (a-3) equal to or greater than the equivalent (mol) of an alkoxy group possessed by the tetraalkoxysilane condensate, And an inorganic / organic composite coating composition comprising a polyhydroxysiloxane solution substantially free of alkoxy groups, obtained by mixing the catalyst (a-4), and an organic binder containing an active energy ray-curable resin. A thing ,
The average condensation degree n _{1 of the} tetraalkoxysilane condensate (a-1) and the average condensation degree n _{2 of the} polyhydroxysiloxane have a relationship of 1 ≦ n ₂ / n ₁ ≦ 3,
Inorganic organic composite coating composition wherein the catalyst (a-4) is an aluminum catalyst selected from aluminum trisacetylacetonate, aluminum monoacetylacetonate bis (ethylacetoacetate), and ethylacetoacetate aluminum diisopropylate object. The (A) polyhydroxysiloxane solution is a tetraalkoxysilane condensate (a-1), an alkoxysilane compound (a-1 ′) having an organic group in part, a hydrophilic organic solvent (a-2), It is obtained by mixing water (a-3) and catalyst (a-4) in an amount equal to or greater than the equivalent (mole) of the alkoxy group of the alkoxysilane compound having a part of the tetraalkoxysilane condensate and the organic group. polyhydroxy siloxane solution der is,
The average condensation degree n _{1 ′ of the} tetraalkoxysilane condensate (a-1) and the alkoxysilane compound (a-1 ′) having an organic group in part and the average condensation degree n _{2 of the} polyhydroxysiloxane are 1 The inorganic-organic composite coating composition according to claim 1 , satisfying a relationship of ≦ n ₂ / n _{1 ′} ≦ 3 . The inorganic-organic composite coating composition according to claim 2 , wherein the alkoxysilane compound (a-1 ′) has a double bond. The inorganic-organic composite coating composition according to any one of claims 1 to 3 , wherein the hydrophilic organic solvent (a-2) contains a compound having a polymerizable double bond. The inorganic-organic composite coating composition according to any one of claims 1 to 4 , wherein the active energy ray-curable resin is a resin having a polymerizable double bond or an epoxy group. The inorganic-organic composite coating composition according to any one of claims 1 to 5 , further comprising a photocuring initiator. The inorganic-organic composite coating composition according to any one of claims 1 to 6, wherein the catalyst (a-4) is aluminum monoacetylacetonate bis (ethylacetoacetate). The coating film formed from the inorganic organic composite coating composition in any one of Claims 1-7 .   The coating film according to claim 8, which is double-cured by heat and active energy rays. A step (1) of applying the inorganic-organic composite coating composition according to any one of claims 1 to 7 on a substrate, and the inorganic-organic composite coating composition applied in step (1) Step to harden (2)
A method for producing a coating film, comprising: