WO2020196750A1

WO2020196750A1 - Organic-inorganic composite resin and method for manufacturing same

Info

Publication number: WO2020196750A1
Application number: PCT/JP2020/013657
Authority: WO
Inventors: 洋樹深海; 松尾　陽一; 宙是横井
Original assignee: 株式会社カネカ
Priority date: 2019-03-28
Filing date: 2020-03-26
Publication date: 2020-10-01
Also published as: CN113631601A; JPWO2020196750A1; JP7433295B2

Abstract

An organic-inorganic composite resin containing a poly(meth)acryl chain and a polyorganosiloxane chain is manufactured by subjecting an alkoxysilane component, which contains an alkoxysilane (a-1) having a radical reactive functional group at least containing a vinyl group and an alkoxysilane (a-2) having no radical reactive functional group, to hydrolysis and dehydration condensation reactions in the presence of water and a condensation catalyst to give a polyorganosiloxane and then radically polymerizing the same with a (meth)acrylate ester monomer. Relative to the sum of (a-1) and (a-2), the ratio of (a-2) is 70-99 wt%. In organic groups contained in (a-2), methyl, ethyl or phenyl group amounts to 50 wt% or more. The equivalence of the radical reactive functional group, which is calculated on the basis of the alkoxysilane component, is 280 or more and less than 5000. Water is added in an amount of 30-60 mol% relative to the sum of the alkoxy groups in the alkoxysilane component.

Description

Organic-inorganic composite resin and its manufacturing method

The present invention relates to an organic-inorganic composite resin, a method for producing the same, a curable resin composition containing the composite resin, and a cured product thereof.

Various resins have been studied as resin components exhibiting curability that constitute a curable composition that can be used as a paint. Among them, polysiloxane-based paints are known as paints aimed at achieving a long life of the coating film, particularly high weather resistance and high heat resistance. Polysiloxane is a curable resin formed by hydrolyzing and dehydrating condensation reaction of organoalkoxysilane. Since the siloxane bond forming this resin is energetically strong, polysiloxane has the property of being difficult to decompose by heat or ultraviolet rays. However, the obtained coating film has low flexibility, and has a problem that cracks are likely to occur due to curing shrinkage of the coating film and a problem that the adhesion to various substrates is low.

On the other hand, acrylic silicone-based paints mainly composed of acrylic resins having a hydrolyzable silyl group are also known. The coating film obtained from the acrylic silicone-based paint has flexibility and is less likely to cause cracks. However, this coating film has a problem of low weather resistance.

In order to provide a paint that has both the advantages of a polysiloxane-based paint and the advantages of an acrylic silicone-based paint, it is conceivable to mix both paints. However, when the polysiloxane-based paint and the acrylic silicone-based paint are simply mixed, the compatibility between the two resins is low, so that the storage stability of the paint is lowered and the coating film formed from the mixed paint causes phase separation. There is a drawback that the coating film becomes cloudy and the transparency is lowered. In this case, there is also a problem that deterioration is likely to occur due to the interface formed inside the coating film.

Therefore, it is being considered to combine polysiloxane and acrylic silicon. For example, Patent Document 1 describes a method for producing a composite resin by reacting an organopolysiloxane and acrylic silicon in the presence of an acid catalyst by a hydrolysis / dehydration condensation reaction of reactive silicon groups of both resins. Has been done.

Further, in Patent Document 2, a cocondensate obtained by hydrolyzing and condensing a silane compound having a polymerizable unsaturated group such as a (meth) acrylic loyl group and a silane compound having an epoxy group, and a (meth) acrylic type. It is described that a composite resin is produced by reacting with a polymerizable monomer such as a monomer.

International Publication No. 2017/16495 International Publication No. 2016/052636

Patent Document 1 describes an organic-inorganic composite resin in which a polysiloxane resin and an acrylic resin are composited, but the graft ratio is not sufficiently high because the production involves a reaction of binding different polymers. The storage stability and the transparency and gloss of the coating film were not sufficiently improved, and in particular, the glossiness of the coating film when a paint containing a pigment was used was not sufficiently improved. Further, in addition to having to give a reactive silicon group to the acrylic resin as a raw material, it is necessary to use methyl methacrylate as a main monomer in order to obtain an acrylic resin composition having high compatibility with a polysiloxane resin. There was a tendency that the types of monomers constituting the acrylic resin were limited.

Further, in Patent Document 2, since an alkoxysilane having a (meth) acryloyl group is used to form a polyorganosiloxane chain, the radical reactivity of the group is too high, so that gelation easily proceeds during radical polymerization. This tended to make manufacturing difficult. Further, the organic-inorganic composite resin described in Patent Document 2 has an epoxy group as an essential functional group, and exhibits curability when used in combination with a photoacid generator.

In view of the above situation, the present invention is a novel organic-inorganic composite resin capable of forming a coating film having excellent transparency or gloss as well as being easy to manufacture by suppressing gelation during production and having excellent storage stability. And its manufacturing method.

As a result of diligent studies to solve the above problems, the present inventors have found that the radical reactivity is lower than the growth reactivity of the methacryloyl group in radical polymerization, instead of the (meth) acryloyl group disclosed in Patent Document 2. An alkoxysilane having the radical-reactive functional groups shown is used to satisfy an equal amount of radical-reactive functional groups in a specific range to obtain a polyorganosiloxane, and in the presence of the polyorganosiloxane, a (meth) acrylic acid ester is obtained. It has been found that a novel organic-inorganic composite resin can be produced by radically polymerizing a radically polymerizable monomer such as a monomer. In addition, the new organic-inorganic composite resin produced has a poly (meth) acrylic chain and a polyorganosiloxane chain bonded only via a hydrocarbon group, and the polyorganosiloxane chain has a reactive silicon group. I found it. We have found that the above problems can be solved by the above, and have arrived at the present invention.

That is, the present invention comprises a monoorganotrialkoxysilane and / or a diorganodialkoxysilane (a-1) having a radical-reactive functional group that exhibits a radical reactivity lower than the growth reactivity of a methacryloyl group in radical polymerization, and a radical. Monoorganotrialkoxysilanes and / or diorganodialkoxysilanes (a-2), which do not have reactive functional groups,
A step of hydrolyzing and dehydrating and condensing a alkoxysilane component containing water in the presence of water and a condensation catalyst to obtain a polyorganosiloxane, and in the presence of the polyorganosiloxane, a (meth) acrylic acid ester monomer is contained. Including the step of radically polymerizing a radically polymerizable monomer component.
The radical-reactive functional group exhibiting a radical reactivity lower than the growth reactivity of the methacryloyl group in the radical polymerization contains at least a vinyl group.
The ratio of (a-2) to the total of (a-1) and (a-2) is 70% by weight or more and 99% by weight or less, and 50% by weight of the organic group contained in (a-2). % Or more is at least one selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.
The radically reactive functional group equivalent amount calculated from the alkoxysilane component is in the range of 280 or more and less than 5000.
The amount of water added is 30 mol% or more and 60 mol% or less with respect to 100% of the total number of moles of alkoxy groups directly bonded to silicon atoms contained in the alkoxysilane component.
The present invention relates to a method for producing an organic-inorganic composite resin containing a poly (meth) acrylic chain and a polyorganosiloxane chain.
Preferably, 50% by weight or more of the organic group contained in (a-2) is a methyl group.
Preferably, the ratio of monoorganotrialkoxysilane and / or diorganodialkoxysilane having a vinyl group to the entire alkoxysilane component is 2% by weight or more and 30% by weight or less.
Preferably, the hydrolysis and dehydration condensation reaction gives a polyorganosiloxane having a reactive silicon group.
Preferably, the weight ratio of the polyorganosiloxane chain to the entire organic-inorganic composite resin is 20% by weight or more and 80% by weight or less.
Preferably, the temperature is controlled so that the temperature of the reaction system does not substantially decrease from the hydrolysis and dehydration condensation reaction to the end of the radical polymerization.
Preferably, the radical polymerization is carried out in the presence of a β-dicarbonyl compound.
Preferably, the hydrolysis and dehydration condensation reactions and the radical polymerization are carried out in an atmosphere substantially free of oxygen molecules.
The present invention is an organic-inorganic composite resin containing a poly (meth) acrylic chain and a polyorganosiloxane chain bonded to the poly (meth) acrylic chain.
The weight ratio of the polyorganosiloxane chain to the entire organic-inorganic composite resin is 20% by weight or more and 80% by weight or less.
The polyorganosiloxane chain is a hydrolysis condensate of an alkoxysilane component containing 70 to 100 mol% of monoorganotrialkoxysilane and 30 to 0 mol% of diorganodialkoxysilane.
The polyorganosiloxane chain has a reactive silicon group and has
The carbon atom in the monomer unit constituting the poly (meth) acrylic chain and the silicon atom in the polyorganosiloxane chain are bonded via only a hydrocarbon group.
The hydrocarbon group contains at least an ethylene group and contains
Of the total of the monoorganotrialkoxysilane and the diorganodialkoxysilane, the proportion of the monoorganotrialkoxysilane and / or the diorganodialkoxysilane (a-2) having no radically reactive functional group is 70. Organic, which is at least 99% by weight and 50% by weight or more of the organic group contained in (a-2) is at least one selected from the group consisting of a methyl group, an ethyl group, and a phenyl group. Also related to inorganic composite resins.
Preferably, the structural unit derived from the monoorganotrialkoxysilane is formed of the structural unit T1 forming one siloxane bond, the structural unit T2 forming two siloxane bonds, and three siloxane bonds. The ratio (%) of the number of moles of T1, T2, and T3 to the total number of moles of T1, T2, and T3 measured by ²⁹ Si-NMR, which are classified into the constituent units T3, is X, Y, respectively. When Z is used, the following formula:
(1 x X + 2 x Y + 3 x Z) / 3
The siloxane bond formation rate calculated by is 60% or more and 80% or less.
Preferably, the solubility parameter value (SP value) of the poly (meth) acrylic chain is 9.0 to 11.0 (cal / cm ³ ) ^1/2 .
Furthermore, the present invention also relates to a curable resin composition containing the organic-inorganic composite resin or a cured product obtained by curing the curable resin composition.

According to the present invention, a novel organic-inorganic composite resin capable of forming a coating film having excellent transparency or gloss as well as being easy to manufacture by suppressing gelation during production and having excellent storage stability, and its manufacture. A method can be provided.
Since the organic-inorganic composite resin according to the preferred embodiment of the present invention has a reactive silicon group, it can be cured by a hydrolysis / dehydration condensation reaction of the reactive silicon group.
The organic-inorganic composite resin according to a preferred embodiment of the present invention generally has excellent storage stability and gloss even when a colored paint containing a pigment whose coating film gloss and storage stability tends to decrease is formed. Can form an excellent coating film. In addition, the organic-inorganic composite resin according to the preferred embodiment of the present invention has high miscibility with pigments and dyes, and can achieve excellent toning properties.
Further, according to the present invention, the monomer species constituting the poly (meth) acrylic chain can be selected from a large number of options, and there is an advantage that the degree of freedom in designing the poly (meth) acrylic chain is high.
Further, in the organic-inorganic composite resin according to the preferred embodiment of the present invention, the poly (meth) acrylic chain and the polyorganosiloxane chain are hydrocarbonized without interposing a heteroatom-containing group such as an ester group such as a (meth) acryloyl group. Since it is bonded only by a hydrogen group, it is not easily affected by main chain cleavage due to hydrolysis or photooxidation, and it can be expected to have excellent weather resistance.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

(Manufacturing method of organic-inorganic composite resin)
First, a method for producing an organic-inorganic composite resin according to an embodiment of the present invention will be described.
(Hydrolysis and dehydration condensation reaction)
In the production method of the present invention, first, hydrolysis of the alkoxysilane component and dehydration condensation reaction are carried out to obtain polyorganosiloxane. The alkoxysilane component used in the present invention includes at least a monoorganotrialkoxysilane and / or a diorganodialkoxysilane (a-1) having a radical-reactive functional group and a monoorganotrialkoxy having no radical-reactive functional group. Includes silanes and / or diorganodialkoxysilanes (a-2). Hereinafter, they may be simply referred to as alkoxysilane (a-1) and alkoxysilane (a-2), respectively.

Alkoxysilane (a-1) is an alkoxysilane that does not have an acryloyl group or a methacryloyl group as an organic group on a silicon atom and has a radically reactive functional group. As the radical-reactive functional group, one that exhibits radical reactivity lower than the growth reactivity of the methacryloyl group in radical polymerization is selected. By using such a radical-reactive functional group, the poly (meth) acrylic chain and the polyorganosiloxane chain can be bonded, gelation during production of the organic-inorganic composite resin is suppressed, and organic. The storage stability of the inorganic composite resin can be improved.

Radical-reactive functional groups that exhibit radical reactivity lower than the growth reactivity of methacryloyl groups in radical polymerization include at least vinyl groups. The vinyl group referred to here refers to a vinyl group directly bonded to a silicon atom, and does not refer to a vinyl group contained in an allyl group or a p-styryl group. The radical-reactive functional group may be a vinyl group alone, or a vinyl group and at least one group selected from the group consisting of an allyl group, a p-styryl group, and a mercapto group may be used in combination. May be good. Such a radical-reactive functional group is preferably directly bonded to the silicon atom of the alkoxysilane (a-1). By using such a radically reactive functional group, it is possible to bond the poly (meth) acrylic chain and the polyorganosiloxane chain only through the hydrocarbon group, and gelation during production is suppressed, and gelation during production is suppressed. , The storage stability of the organic-inorganic composite resin can be improved. In order to realize the bond between the poly (meth) acrylic chain and the polyorganosiloxane chain only through the hydrocarbon group, an alkoxysilane having an ester-containing group such as an acryloyl group or a methacryloyl group or an ether bond-containing group such as vinyloxy is used. It is preferable not to use it.

Further, the alkoxysilane (a-1) may be a monoorganotrialkoxysilane, a diorganodialkoxysilane, or may contain both, but the monoorganotrialkoxysilane may be used. Silane is preferred. Here, the monoorganotrialkoxysilane refers to a silane compound having one organic group and three alkoxy groups as a substituent on the silicon atom, and the diorganodialkoxysilane is on the silicon atom. As a substituent, it refers to a silane compound having two organic groups and two alkoxy groups.

The organic group contained in the alkoxysilane (a-1) refers to an organic group other than the alkoxy group, and specific examples thereof are not particularly limited. For example, the above-mentioned vinyl group, allyl group, p-styryl group, and mercapto group are used. In addition, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms such as a phenyl group, and the like can be mentioned. The alkyl group or aryl group may be an unsubstituted group or may have a non-radical reactive substituent such as a glycidyloxy group or an epoxycyclohexyl group. The alkyl group having 1 to 6 carbon atoms is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. The alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, and even more preferably 1 to 2 carbon atoms. As the organic group, only one type may be used, or two or more types may be mixed.

The alkoxy group contained in the alkoxysilane (a-1) is not particularly limited, and examples thereof include an alkoxy group having 1 to 3 carbon atoms. Specifically, it is a methoxy group, an ethoxy group, or a propoxy group, preferably a methoxy group or an ethoxy group, and more preferably a methoxy group. As the alkoxy group, only one type may be used, or two or more types may be mixed.

Specific examples of the alkoxysilane (a-1) are not particularly limited, but for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, divinyldimethoxysilane, divinyldiethoxysilane; allyl. Trimethoxysilane, allyltriethoxysilane, allylmethyldimethoxysilane, allylmethyldiethoxysilane; p-styryltrimethoxysilane, p-styryltriethoxysilane, p-styrylmethyldimethoxysilane, p-styrylmethyldiethoxysilane; 3 -Mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane and the like can be mentioned. Of these, monoorganotrialkoxysilanes and / or diorganodialkoxysilanes having a vinyl group are preferable, and vinyltrialkoxysilanes are more preferable.

The smaller the amount of the monoorganotrialkoxysilane and / or the diorganodialkoxysilane having a vinyl group used, the more the gelation during production can be suppressed, and the larger the amount, the poly (meth) acrylic chain and the polyorganosiloxane. The graft ratio of the chains can be increased to enhance the transparency and gloss of the coating film. From these viewpoints, the proportion of monoorganotrialkoxysilane and / or diorganodialkoxysilane having a vinyl group with respect to the entire alkoxysilane component is preferably 2% by weight or more and 30% by weight or less, preferably 3% by weight. 28% by weight or more is preferable, and 4% by weight or more and 25% by weight or less is more preferable.

Alkoxysilane (a-2) is an alkoxylan having no radically reactive functional group such as a (meth) alicloyl group or a vinyl group, and may be a monoorganotrialkoxysilane or a diorganodialkoxysilane. It may be present or may contain both, but monoorganotrialkoxysilane is preferable.

The organic group that the alkoxysilane (a-2) has as a substituent on the silicon atom refers to an organic group other than the alkoxy group that does not contain a radical reactive functional group. Specific examples thereof are not particularly limited, and examples thereof include an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 12 carbon atoms such as a phenyl group. The alkyl group or aryl group may be an unsubstituted group or may have a non-radical reactive substituent such as a glycidyloxy group or an epoxycyclohexyl group. The alkyl group having 1 to 6 carbon atoms is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. The alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, and even more preferably 1 to 2 carbon atoms. As the organic group, only one type may be used, or two or more types may be mixed.

As the organic group contained in the alkoxysilane (a-2), at least one selected from the group consisting of a methyl group, an ethyl group, and a phenyl group is preferable. In this case, the ratio of the total of the methyl group, the ethyl group, and the phenyl group to the total organic group of (a-2) is preferably 50% by weight or more, more preferably 70% by weight or more, and 80% by weight. % Or more is more preferable. The upper limit of the ratio may be 100% by weight. Since the curability becomes high when the produced organic-inorganic composite resin is used as the main component of the coating liquid, the organic group of (a-2) is more preferably containing a methyl group and / or an ethyl group, and is methyl. It is more preferable to include a group. Further, it preferably contains a methyl group and / or an ethyl group and a phenyl group, and particularly preferably contains a methyl group and a phenyl group. By using a phenyl group in combination, it becomes easier to suppress gelation during radical polymerization, which will be described later, and it is possible to achieve both storage stability of the organic-inorganic composite resin and transparency and gloss of the coating film at a high level. it can.

In a particularly preferable embodiment, from the viewpoint of curability, the ratio of the methyl group to the total organic group of (a-2) is preferably 50% by weight or more, more preferably 70% by weight or more. , 80% by weight or more is more preferable. The upper limit of the proportion of the methyl group may be 100% by weight, but when an ethyl group and / or a phenyl group are used in combination as described above, it is preferably 99% by weight or less. When an ethyl group and / or a phenyl group are used in combination, the ratio of the ethyl group and / or the phenyl group to the total organic group of (a-2) is preferably 0 to 45% by weight.

Examples of the alkoxy group that the alkoxysilane (a-2) has as a substituent on the silicon atom include the same group as the above-mentioned alkoxy group for the alkoxysilane (a-1).

Specific examples of the alkoxysilane (a-2) are not particularly limited, but examples of the monoorganotrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, and ethyltri. Ethoxysilane, ethyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltriisopropoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltriisopropoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane , Hexyltriisopropoxysilane and the like. Examples of the diorganodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, and the like. Examples thereof include cyclohexylmethyldimethoxysilane and cyclohexylmethyldiethoxysilane.

Specific examples of the alkoxysilane (a-2) having an epoxy group such as the above-mentioned glycidyloxy group and epoxycyclohexyl group include 3-glycidyloxypropyltrimethoxysilane and 3-glycidyloxypropyltriethoxysilane. , 3-Glysidyloxypropylmethyldimethoxysilane, 8-glycidyloxyoctyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like. By using such an alkoxysilane having an epoxy group, the molecular weight of the obtained organic-inorganic composite resin can be increased. When an alkoxysilane having an epoxy group is used, the amount used is preferably 0.1% by weight or more as a ratio of the total amount of the alkoxysilane component. The amount used is preferably 20% by weight or less, more preferably 15% by weight or less, and even more preferably 10% by weight or less. However, it is not necessary to use an alkoxysilane having an epoxy group, and in that case, the transparency and gloss of the coating film obtained by using the organic-inorganic composite resin can be enhanced.

As the alkoxysilane (a-2), it is particularly preferable to use at least one selected from the group consisting of methyltrialkoxysilane, ethyltrialkoxysilane, and phenyltrialkoxysilane. In that case, the ratio of the total of methyltrialkoxysilane, ethyltrialkoxysilane, and phenyltrialkoxysilane to the entire alkoxysisilane component is preferably 70% by weight or more, preferably 80% by weight or more. Is more preferable.

Further, it is particularly preferable to use methyltrialkoxysilane as the alkoxysilane (a-2). In this case, the proportion of methyltrialkoxysilane to the entire alkoxysilane component is preferably 40% by weight or more and less than 100% by weight, more preferably 40% by weight or more and 95% by weight or less, and 45% by weight or more and 95% by weight or more. It is more preferably 50% by weight or more, particularly preferably 50% by weight or more and 95% by weight or less, and most preferably 50% by weight or more and 90% by weight or less. Of the organoalkoxysilanes, the condensate of methyltrialkoxysilane has the highest silicon content. Therefore, as the content of methyltrialkoxysilane in the entire alkoxysilane component increases, the produced polyorganosiloxane chain is peculiar to the inorganic resin. It is preferable because the effect is easily exhibited. Conventionally, when the content of methyltrialkoxysilane is increased, gelation during production tends to occur, but according to the production method of the present invention, the gelation can be suppressed.

The alkoxysilane component used in the present invention includes a radical-reactive functional group contained in the alkoxysilane (a-1) and an alkoxy group on the silicon atom of the alkoxysilane (a-1) and the alkoxysilane (a-2). However, the content ratio of the compound of the alkoxysilane component is set so that the content ratio falls within a specific range. In the present invention, an equal amount of radical-reactive functional groups is used as an index indicating the content ratio of radical-reactive functional groups and alkoxy groups in the alkoxysilane component. The radical-reactive functional group equal amount is a radical when it is assumed that all the alkoxy groups on the silicon atom contained in the alkoxysilane component are converted into siloxane bonds by the hydrolysis / dehydration condensation reaction to form a polysiloxane. It is a value calculated as the molecular weight of the polysiloxane per reactive functional group. A specific calculation method will be described in the section of Examples described later.

In the present invention, the equivalent amount of radical-reactive functional groups calculated from the total amount of the alkoxysilane component used as a raw material satisfies 280 or more and less than 5000. A small value of the equivalent amount of radical-reactive functional groups means that the relative amount of radical-reactive functional groups is large, and conversely, a large value of the equivalent amount of radical-reactive functional groups means that the radicals are large. It means that the relative amount of reactive radicals is small. When the amount of radical-reactive functional groups is smaller than the above range, gelation proceeds during radical polymerization described later, making it difficult to produce an organic-inorganic composite resin, or even if it can be produced, the storage stability of the resin is lowered. Tend. On the contrary, when the equivalent amount of radical-reactive functional groups is larger than the above range, the molecular weight of the obtained organic-inorganic composite resin can be reduced, but in the radical polymerization described later, the poly (meth) acrylic chain and the polyorganosiloxane chain are separated. Bonding does not proceed sufficiently, phase separation occurs in the coating film, and the transparency and gloss of the coating film tend to decrease.

Within the above range, the smaller the amount of the radical reactive functional group is, the better the graft ratio between the poly (meth) acrylic chain and the polyorganosiloxane chain, the compatibility between the organic resin and the inorganic resin, and the storage stability of the paint. , The gloss of the coating film can be increased. Further, within the above range, the larger the equivalent amount of radical-reactive functional groups, the more the gelation during production can be suppressed, and the reproducibility of production can be improved. From the above viewpoint, the radical reactive functional group equivalent amount is preferably 300 or more, more preferably 500 or more, further preferably 800 or more, and particularly preferably 1000 or more. The radical-reactive functional group equivalent is preferably 4000 or less, more preferably 3000 or less, further preferably 2500 or less, and particularly preferably 2000 or less.

The ratio of alkoxysilane (a-1) and alkoxysilane (a-2) used can be appropriately set in consideration of the above radical reactive functional group equivalents, the molecular weight of the polyorganosiloxane chain, and the like. Specifically, the ratio of (a-1) to the total of alkoxysilane (a-1) and alkoxysilane (a-2) is 1% by weight or more and 30% by weight or less, and (a-2) occupies. The ratio is preferably 70% by weight or more and 99% by weight or less, the ratio of (a-1) is 5% by weight or more and 25% by weight or less, and the ratio of (a-2) is 75% by weight or more and 95% by weight or less. preferable. Further, the proportion of (a-1) to the entire alkoxysilane component is preferably 1% by weight or more and 30% by weight or less, and the proportion of (a-2) is preferably 70% by weight or more and 99% by weight or less, and (a). The proportion of -1) is more preferably 5% by weight or more and 25% by weight or less, and the proportion of (a-2) is more preferably 75% by weight or more and 95% by weight or less.

The alkoxysilane component may be composed of only alkoxysilane (a-1) and alkoxysilane (a-2), or in addition to these, alkoxysilane (a-1) and alkoxysilane (a). It may further contain an alkoxysilane (a-3) that does not belong to any of -2). Examples of the alkoxysilane (a-3) include an alkoxysilane having a (meth) acryloyl group, a triorganomonoalkoxysilane, and a tetraalkoxysilane. Alkoxysilane (a-3) does not have to be used, but when alkoxysilane (a-3) is used, the amount used may be determined within a range that does not impair the effects of the present invention. For example, the alkoxysilane component. 10% by weight or less is preferable, 5% by weight or less is more preferable, and 1% by weight or less is further preferable.

Polyorganosiloxane can be formed by hydrolyzing and dehydrating and condensing the alkoxysilane component described above in the presence of water and a condensation catalyst. The produced polyorganosiloxane has a radically reactive functional group derived from alkoxysilane (a-1).

Further, according to a preferred embodiment, after some of the alkoxy groups contained in the alkoxysilane component remain unreacted or the alkoxysilane component undergoes a hydrolysis reaction, the dehydration condensation reaction does not proceed. By remaining as a silanol group in, the produced polyorganosiloxane can further have a reactive silicon group. Here, the reactive silicon group is a concept including both an alkoxysilyl group and a silanol group.

In the hydrolysis and dehydration condensation reaction, water is added to proceed the reaction. At this time, by controlling the amount of water used, gelation during radical polymerization can be suppressed and the storage stability of the organic-inorganic composite resin can be improved. From this point of view, the amount of water used is 100% based on the total number of moles of alkoxy groups directly bonded to the silicon atom contained in the alkoxysilane component, and is 30 mol% or more and 60 mol% or less. The upper limit is preferably 55 mol% or less. The lower limit is preferably 35 mol% or more, more preferably 40 mol% or more, and particularly preferably 45 mol% or more.

In the hydrolysis and dehydration condensation steps, an organic solvent other than water may be used in addition to water. As such an organic solvent, a water-soluble organic solvent is preferable because it is used in combination with water. Further, in order to ensure the solubility of the alkoxysilane component, an organic solvent having 4 or more carbon atoms is preferable. From the above viewpoint, preferred organic solvents include, for example, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, and ethylene glycol monobutyl ether. Diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol Examples thereof include, but are not limited to, monopropyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and ethylene glycol diethyl ether.

Since the organic solvent will be volatilized after the production of the organic-inorganic composite resin or when the coating film is formed, an organic solvent having a boiling point of 150 ° C. or lower under atmospheric pressure is preferable. Specifically, ethylene glycol monoethyl ether. Ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monoethyl ether, and propylene glycol dimethyl ether are particularly preferable.

The hydrolysis and dehydration condensation reactions are carried out in the presence of a condensation catalyst to promote the reaction. As the condensation catalyst, a known one can be used. Condensation catalysts are roughly classified into basic catalysts and acidic catalysts. The acidic catalyst has an action of accelerating hydrolysis compared to condensation, and as a result, the obtained polyorganosiloxane has a relatively large number of silanol groups. Since the silanol group is stabilized in an acidic solution, the storage stability of the organic-inorganic composite resin is improved. Therefore, it is preferable to carry out the hydrolysis and dehydration condensation steps of the present invention in the presence of an acidic catalyst as the condensation catalyst.

As the acidic catalyst, an organic acid is preferable, and a phosphoric acid ester or a carboxylic acid is more preferable, because of compatibility with an alkoxysilane component and an organic solvent. Specific examples of organic acids include ethyl acid phosphate, butyl acid phosphate, butyl pyrophosphate (or dibutylpyrophosphate), butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, isotridecyl acid phosphate, dibutyl phosphate, and bis (2-). Ethylhexyl) phosphate, formic acid, acetic acid, butyric acid, isobutyric acid and the like can be mentioned.

Examples of the basic catalyst include N-ethylmorpholine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine, triethylamine, n-butylamine, hexylamine, and triethanolamine. Examples thereof include amine compounds such as diazabicycloundecene and ammonia, and metal hydroxides such as sodium hydroxide and potassium hydroxide.

A neutral salt can also be used as the condensation catalyst. Even if a neutral salt is used, the same effect as when an acidic catalyst is used can be obtained. Here, the neutral salt is a normal salt composed of a strong acid and a strong base, and is, for example, a group consisting of a group 1 element ion, a group 2 element ion, a tetraalkylammonium ion, and a guanidium ion as cations. It is a salt composed of a combination of any one selected from the above and one selected from the group consisting of Group 17 element ions excluding fluoride ions, sulfate ions, nitrate ions, and perchlorate ions as anions. In particular, the anion is preferably a group 17 element ion because it has high nucleophilicity, and the cation is a group 1 element ion or a group 2 ion as a non-bulky ion so as not to inhibit the nucleophilic action. Element ions are preferred.

The specific compound of the neutral salt is not particularly limited, but for example, preferred neutral salts include lithium chloride, sodium chloride, potassium chloride, ravidium chloride, cesium chloride, magnesium chloride, calcium chloride, strontium chloride, lithium bromide, and the like. Sodium bromide, potassium bromide, ravidium bromide, cesium bromide, magnesium bromide, calcium bromide, strontium bromide, lithium iodide, sodium iodide, potassium iodide, ravidium iodide, cesium iodide, iodide Examples include magnesium, calcium iodide, and strontium iodide.

The amount of the condensation catalyst added can be adjusted as appropriate, but may be, for example, about 50 ppm to 3% by weight with respect to the alkoxysilane component. However, in order to suppress the progress of gelation during the production or storage of the organic-inorganic composite resin, the smaller the amount of the condensation catalyst used, the more suitable it is within the range in which the effect of shortening the reaction time by the condensation catalyst is achieved.

A person skilled in the art can appropriately set the reaction temperature when carrying out the hydrolysis and dehydration condensation steps, but for example, it is preferable to heat the reaction solution in the range of 50 to 150 ° C. The reaction time can be appropriately set by those skilled in the art, but may be, for example, about 10 minutes to 12 hours.

After performing the hydrolysis and dehydration condensation steps, it is preferable to carry out a step of removing the alcohol generated in the hydrolysis step from the reaction solution. By removing the alcohol, the hydrolysis reaction that produces alcohol as a by-product can be further promoted. The alcohol removal step can be carried out by subjecting the reaction solution after the hydrolysis and dehydration condensation steps to vacuum distillation to distill off the alcohol. The conditions for vacuum distillation can be appropriately set by those skilled in the art.

In the hydrolysis and dehydration condensation reactions, the radical-reactive functional groups of the alkoxysilane (a-1) are substantially unaffected. Therefore, the polyorganosiloxane produced in the reaction is as described above. It will have a radically reactive functional group derived from alkoxysilane (a-1).

The number of radical-reactive functional groups per molecule of polyorganosiloxane is not particularly limited, but may be about 1 or more. When the number is one or more, the graft ratio of the poly (meth) acrylic chain and the polyorganosiloxane chain can be increased, and good transparency and gloss of the coating film can be achieved. Further, the number may exceed 3 or 4 or more. Even if a polyorganosiloxane having such a large number of radical-reactive functional groups is used, gelation during production can be suppressed according to the production method of the present invention. The number is preferably 8 or less from the viewpoint of suppressing gelation and improving storage stability.

(Radical polymerization)
In the present invention, a polyorganosiloxane is obtained by hydrolysis and dehydration condensation reaction of the alkoxysilane component, and then a radically polymerizable monomer component containing a (meth) acrylic acid ester monomer is radically polymerized in the presence of the polyorganosiloxane. As a result, an organic-inorganic composite resin containing a poly (meth) acrylic chain and a polyorganosiloxane chain is produced. In the radical polymerization, first, the polymerization of the radically polymerizable monomer component containing the (meth) acrylic acid ester monomer having high growth reactivity in the radical polymerization proceeds to form a poly (meth) acrylic chain, and then the poly (meth) acrylic chain is formed. A poly (meth) acrylic chain and a polyorganosiloxane chain are composited by reacting a radical-reactive functional group that exhibits a radical reactivity lower than the growth reactivity of the methacryloyl group in radical polymerization at the end of the meta) acrylic chain. Is realized. However, some of the radically reactive functional groups exhibiting low radical reactivity may copolymerize with a portion other than the terminal of the poly (meth) acrylic chain. The (meth) acrylic refers to acrylic and / or methacrylic.

The (meth) acrylic acid ester monomer is not particularly limited, and for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate and other alkyl (meth) acrylates having an alkyl group having 1 to 22 carbon atoms; benzyl (meth) acrylate, 2 -Aralkyl (meth) acrylates such as phenylethyl (meth) acrylate; cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; 2-methoxyethyl (meth) acrylate, 4-methoxybutyl Ω-alkoxyalkyl (meth) acrylates such as (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) Hydroxyl-containing (meth) acrylates such as acrylates and glycerol mono (meth) acrylates; 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropyl Cyril group-containing (meth) acrylates such as triethoxysilane, 3- (meth) acryloyloxypropylmethyldiethoxysilane, (meth) acryloyloxyoctylrimethoxysilane, and (meth) acryloyloxyoctylriethoxysilane Can be mentioned. Only one of these may be used, or two or more thereof may be used in combination.

The radically polymerizable monomer component to be subjected to radical polymerization may be only the (meth) acrylic acid ester monomer described above, but the (meth) acrylic acid ester monomer may be used in combination with another radically polymerizable monomer. Good. The radically polymerizable monomer is not particularly limited, but for example, unsaturated carboxylic acids such as (meth) acrylic acid; (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, Acrylamides such as N-dimethyl (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide; styrene, α-methylstyrene, chlorostyrene, styrenesulfonic acid, 4-hydroxystyrene, vinyltoluene Aromatic hydrocarbon vinyl compounds such as; acid anhydrides of unsaturated carboxylic acids such as maleic anhydride, diesters of these acid anhydrides with alcohols or amines having linear or branched chains of 1 to 20 carbon atoms or Saturated carboxylic acid esters such as half esters; vinyl esters and aryl compounds such as vinyl acetate, vinyl propionate, diallyl phthalate; amino group-containing vinyl compounds such as vinyl pyridine and aminoethyl vinyl ether; itaconic acid diamide, crotonic acid Amide group-containing vinyl compounds such as amide, maleic acid diamide, fumaric acid diamide, N-vinylpyrrolidone; (meth) acrylonitrile, 2-hydroxyethyl vinyl ether, methyl vinyl ether, cyclohexyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene. , Propylene, butadiene, isoprene, fluoroolefin maleimide, N-vinylimidazole, vinyl sulfonic acid and the like. Only one of these may be used, or two or more thereof may be used in combination.

The ratio of the (meth) acrylic acid ester monomer to the entire radically polymerizable monomer component can be appropriately set. However, from the viewpoint of adhesion of the produced organic-inorganic composite resin to the base material, it is preferable that the methacrylic acid ester monomer accounts for 60% by weight or more, and 65% by weight, based on the entire radically polymerizable monomer component. The above is more preferable, and 70% by weight or more is further preferable.

Regarding the types and proportions of the monomers constituting the poly (meth) acrylic chain, the solubility parameter value (SP value) of the formed poly (meth) acrylic chain is 9.0 to 11.0 (cal / cm ³ ) ^1. It is preferably selected so that it is in the range of ^{/ 2} . When the SP value of the poly (meth) acrylic chain is in this range, it becomes easy to dissolve the produced organic-inorganic composite resin in a weak solvent to provide a coating material. In particular, it was difficult to combine a poly (meth) acrylic chain and a polyorganosiloxane chain having an SP value in the range of 9.0 to 10.0 (cal / cm ³ ) ^1/2 by the conventional method. According to the present invention, an organic-inorganic composite resin in which a poly (meth) acrylic chain showing such an SP value is composited can be preferably produced. The SP value is more preferably 9.2 to 10.0 (cal / cm ³ ) ^{1/2, and} particularly preferably 9.4 to 9.9 (cal / cm ³ ) ^1/2 .

The SP value is Fedors [Robert F. et al. Fedors, Polymer Engineering and Science, 14, 147-154 (1974)], and the value δ is calculated by the following formula.
Fedors formula: δ = (ΣΔei / ΣΔvi) ^1/2
In the formula, Δei: indicates the evaporation energy (cal / mol) of atoms and atomic groups, and Δvi: indicates the molar volume (cm ³ / mol).

The number of carbon atoms contained in the monomer unit constituting the poly (meth) acrylic chain is not particularly limited, but for example, when an organic-inorganic composite resin is dissolved in a weak solvent to form a coating material, the number of carbon atoms in the side chain of the monomer unit is limited. Is preferably in the range of 3 to 7, more preferably in the range of 3.3 to 6.7, and even more preferably in the range of 3.5 to 6.2. The carbon number of the side chain is, for example, the carbon number of the ester portion in the case of a (meth) acrylic acid ester monomer, and in the case of other monomers, the carbon-carbon unsaturated bond forming the main chain of the polymer is formed. It is the carbon number of the part to be excluded. Specifically, the side chain of methyl methacrylate has a carbon number of 1, the side chain of butyl methacrylate has a carbon number of 4, cyclohexyl methacrylate has a carbon number of 6, and the side chain of 2-hirodoxyethyl methacrylate has a carbon number of 2. The side chain of 3-methacryloyloxypropyltrimethoxysilane has 6 carbon atoms, and the styrene side chain has 6 carbon atoms. If a large amount of monomers with large steric damage around the main chain, such as butyl methacrylate and cyclohexyl methacrylate, are used, the compatibility with polyorganosiloxane decreases, so in general, polyorganosiloxane chains and poly (meth) acrylic chains are used. Although compounding becomes difficult, according to the present invention, an organic-inorganic composite resin in which a polyorganosiloxane chain and a poly (meth) acrylic chain are compounded can be produced even if a large amount of such a monomer having a large carbon number is used. be able to.

The radically polymerizable monomer component containing the (meth) acrylic acid ester monomer described above is mixed with the polyorganosiloxane to carry out radical polymerization. The method of radical polymerization can be a conventional method, and known polymerization methods such as a massive radical polymerization method, a solution radical polymerization method, and a non-aqueous dispersion radical polymerization method can be used.

Radical polymerization is carried out in the presence of a radical polymerization initiator. The radical polymerization initiator is not particularly limited, and is, for example, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,2'-azobis). 2-Methylbutylonitrile), tert-butylperoxypivalate, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, diisopropyl Examples thereof include peroxycarbonate. Only one of these may be used, or two or more thereof may be used in combination.

The amount of the radical polymerization initiator used is not particularly limited, but the molecular weight of the produced organic-inorganic composite resin can be controlled by adjusting the amount used, and gelation during radical polymerization can be suppressed. Can be done. Specifically, the amount of the radical polymerization initiator used may be, for example, 0.1 to 10 parts by weight, preferably 0.5 to 7 parts by weight, based on 100 parts by weight of the radically polymerizable monomer component.

The radical polymerization can be preferably carried out by adding a radically polymerizable monomer component and a radical polymerization initiator to the system containing the polyorganosiloxane obtained by the hydrolysis / dehydration condensation reaction. That is, it is not necessary to take out the produced polyorganosiloxane from the reaction vessel and transfer it to another reaction vessel, and the hydrolysis / dehydration condensation reaction and radical polymerization can be continuously carried out in one reaction vessel. The production method of the present invention has a process advantage that an organic-inorganic composite resin can be produced while suppressing gelation by such a simple method.

The radical polymerization may be carried out in the presence of a β-dicarbonyl compound. The β-dicarbonyl compound is a compound having a structure in which two carbonyl groups are bonded with one carbon atom sandwiched between them. By allowing the β-dicarbonyl compound to exist in the polymerization system, it is possible to suppress the progress of the dehydration condensation reaction of the silanol group of the polyorganosiloxane during radical polymerization. This makes it easy for the produced organic-inorganic composite resin to retain a silanol group. The β-dicarbonyl compound is not particularly limited, and examples thereof include acetylacetone, dimedone, cyclohexane-1,3-dione, methyl acetoacetate, ethyl acetoacetate, dimethyl malonate, diethyl malonate, and meldrum's acid. The amount of the β-dicarbonyl compound used may be set so as to achieve the above effect. For example, it may be 0.01 to 10 parts by weight with respect to 100 parts by weight of the polyorganosiloxane, and 0.1 to 5 parts by weight. It may be about a part by weight.

The polymerization temperature during radical polymerization can be determined by a conventional method. However, when the temperature of the reaction system decreases after the polyorganosiloxane containing silanol groups is produced by hydrolysis and dehydration condensation reaction, the dehydration condensation reaction between silanol groups tends to proceed, and the produced organic-inorganic composite resin The molecular weight of the siloxane may fluctuate, and gelation may easily proceed during radical polymerization. Therefore, from the viewpoint of suppressing fluctuations in molecular weight and progress of gelation, temperature control is performed from the hydrolysis and dehydration condensation reaction to the end of the radical polymerization so that the temperature of the reaction system does not substantially decrease. Is preferable. Here, when the temperature of the reaction system does not substantially decrease, the temperature at the time of radical polymerization is set to be substantially the same as the temperature at the time of hydrolysis and dehydration condensation reaction, or the temperature at the time of hydrolysis and dehydration condensation reaction is substantially the same. It means setting it higher than the hour temperature. In addition, the term "substantially does not decrease" includes the case where the temperature of the reaction system decreases slightly within a range that does not cause a substantial problem from the viewpoint of suppressing fluctuations in molecular weight and progress of gelation. Specifically, it also includes a case where the temperature decreases in the range of less than 5 ° C., preferably less than 3 ° C.

Further, it is preferable that the hydrolysis and dehydration condensation reaction and the radical polymerization are carried out in an atmosphere substantially free of oxygen molecules. As a result, the reaction of the radically reactive functional group exhibiting low radical reactivity is promoted, the graft ratio of the poly (meth) acrylic chain and the polyorganosiloxane chain is improved, and the transparency or gloss of the coating film is improved. Can be done.

By the above radical polymerization, a poly (meth) acrylic chain is formed, and the radical reactive functional group exhibiting low radical reactivity reacts with the terminal of the poly (meth) acrylic chain to bond polyorganosiloxane. By doing so, an organic-inorganic composite resin containing a poly (meth) acrylic chain and a polyorganosiloxane chain is produced.

According to a preferred embodiment, the polyorganosiloxane chain contained in the produced organic-inorganic composite resin can have a reactive silicon group (alkoxysilyl group and / or silanol group). With this reactive silicon, the organic-inorganic composite resin can exhibit curability utilizing the hydrolysis / dehydration reaction of the reactive silicon group.

In this case, in order to ensure the stability of the reactive silicon, it is preferable to mix the dehydrating agent with the produced organic-inorganic composite resin. As a result, the storage stability of the organic-inorganic composite resin having a reactive silicon group in the polyorganosiloxane chain can be improved. As the dehydrating agent, known ones can be used and are not particularly limited, and for example, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane. , Methyl orthoate, ethyl orthoate, methyl orthoacetate, or ethyl orthoacetate is preferred. Only one of these may be used, or a plurality of these may be used.

The amount of the dehydrating agent used is not particularly limited, and can be appropriately determined by those skilled in the art in consideration of the amount of water contained in the organic-inorganic composite resin before dehydration and the target water content after dehydration. As an example, it is about 0.01 to 20 parts by weight, and may be about 0.1 to 10 parts by weight with respect to 100 parts by weight of the organic-inorganic composite resin.

(Organic-inorganic composite resin)
Next, the organic-inorganic composite resin according to the embodiment of the present invention will be described.
The organic-inorganic composite resin of the present invention is formed by bonding a poly (meth) acrylic chain and a polyorganosiloxane chain, and the bond between the two chains is carbon in the monomer unit constituting the poly (meth) acrylic chain. This is achieved by linking the atom and the silicon atom in the polyorganosiloxane chain not via a heteroatomic group such as an ester group, an ether group, an amide group, or an imide group, but via a hydrocarbon group only. The carbon atom in the monomer unit constituting the poly (meth) acrylic chain refers to a carbon atom forming the main chain of the poly (meth) acrylic chain, and refers to the poly (meth) acrylic chain. It does not refer to the carbon atom contained in the side chain.

The connecting portion of both chains is expressed by the following equation.
-CR-Si-
In the formula, C represents a carbon atom contained in the monomer unit constituting the poly (meth) acrylic chain. The carbon atom is a carbon atom that constitutes a carbon-carbon double bond in the monomer before polymerization for producing a poly (meth) acrylic chain. R represents a divalent hydrocarbon group. Si represents a silicon atom contained in a polyorganosiloxane chain. As described above, the poly (meth) acrylic chain and the polyorganosiloxane chain are not bonded by a heteroatom-containing group such as an ester group or an ether group, but are bonded only via a hydrocarbon group.

The hydrocarbon group is a divalent bonding group that bonds a carbon atom in the monomer unit constituting the poly (meth) acrylic chain and a silicon atom in the polyorganosiloxane chain. The number of carbon atoms is not particularly limited, but is preferably 2 to 20, more preferably 2 to 8, further preferably 2 to 4, further preferably 2 to 3, and particularly preferably 2. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. It may be linear or branched. Specifically, an ethylene group (including 1,2-ethylene group and 1,1-ethylene group), a propylene group (1,3-propylene group, 2,3-propylene group, etc.), or a p-phenylene ethylene group. (Including p-phenylene-1,2-ethylene group and p-phenylene-1,1-ethylene group). The hydrocarbon group is preferably derived from the radically reactive double bond-containing group contained in the above-mentioned alkoxysilane (a-1), for example, an alkoxy having a vinyl group as the alkoxysilane (a-1). When silane is used, an ethylene group is formed as the hydrocarbon group. The hydrocarbon group preferably contains at least an ethylene group. The ethylene group referred to here does not mean an ethylene group contained in a propylene group or a p-phenylene ethylene group.

The poly (meth) acrylic chain refers to a homopolymer or copolymer of a radically polymerizable monomer component containing a (meth) acrylic acid ester monomer. Details of the types and proportions of the monomers forming the poly (meth) acrylic chain are as described above.

The polyorganosiloxane chain refers to a hydrolyzed condensate of an alkoxysilane component containing 70 to 100 mol% of monoorganotrialkoxysilane and 30 to 0 mol% of diorganodialkoxysilane. The definitions of the monoorganotrialkoxysilane and the diorganodialkoxysilane are as described above. The monoorganotrialkoxysilane is an essential component, but the diorganodialkoxysilane may or may not be used. The proportion of diorganodialkoxysilane in the total of monoorganotrialkoxysilane and diorganodialkoxysilane is 30% by weight or less, preferably 20% by weight or more, more preferably 10% by weight or less, and 5% by weight. The following is even more preferable, and 1% by weight or less is even more preferable.

In order to realize the bond between the poly (meth) acrylic chain and the polyorganosiloxane chain in the organic-inorganic composite resin of the present invention, a radically reactive double bond-containing group is used as a monoorganotrialkoxysilane and / or a diorganodialkoxysilane. Monoorganotrialkoxysilanes and / or diorganodialkoxysilanes (a-1) having the above are used. Further, it is preferable to use monoorganotrialkoxysilane and / or diorganodialkoxysilane (a-2) having no radical-reactive double bond-containing group together with (a-1). Details of the (a-1) and (a-2) are as described above.

The polyorganosiloxane chain according to the preferred embodiment has a reactive silicon group as described above. Due to the presence of the reactive silicon group, the organic-inorganic composite resin of the present invention can exhibit curability by hydrolysis / dehydration condensation reaction.

In order for the polyorganosiloxane chain to have a reactive silicon group, the siloxane bond formation rate (also referred to as the condensation rate) of the polyorganosiloxane chain needs to be less than 100%. Here, the siloxane bond formation rate is a numerical value indicating the conversion rate of the alkoxy group on the silicon atom contained in the alkoxysilane component of the raw material into a siloxane bond, and when all the alkoxy groups are converted into siloxane bonds, It becomes 100%.

The siloxane bond formation rate is a structural unit derived from monoorganotrialkoxysilane, a structural unit T1 forming one siloxane bond, a structural unit T2 forming two siloxane bonds, and a siloxane bond. Classified into three constituent units T3, the ratio (%) of the number of moles of T1, T2, and T3 to the total number of moles of T1, T2, and T3 measured by ²⁹ Si-NMR is X, respectively. , Y, Z, it is a value calculated by the following formula. The total of X, Y, and Z is 100.
Siloxane bond formation rate = (1 x X + 2 x Y + 3 x Z) / 3

When the siloxane bond formation rate is close to 100%, almost all the alkoxy groups are converted into siloxane bonds, so that the number of reactive silicon groups in the polyorganosiloxane chain is reduced. On the other hand, if the siloxane bond formation rate is too low, a polyorganosiloxane chain having a sufficient molecular weight is not formed, and it becomes difficult for the organic-inorganic composite resin to exhibit the physical properties derived from the polyorganosiloxane chain. From the above viewpoint, the organic-inorganic composite resin of the present invention preferably has a siloxane bond formation rate of 20% or more and 80% or less. It is more preferably 30% or more, further preferably 40% or more, still more preferably 50% or more, particularly preferably 60% or more, and most preferably 65% or more. Further, from the viewpoint of the reactivity of the reactive silicon group of the polyorganosiloxane chain, the siloxane bond formation rate is more preferably 75% or less, still more preferably 72% or less.

The siloxane bond formation rate adjusts the amount of water used during the hydrolysis / dehydration condensation reaction for forming a polyorganosiloxane chain, the type / amount of catalyst, and the reaction of components that stabilize silanol groups. It can be adjusted by coexisting with the system.

In the organic-inorganic composite resin of the present invention, the ratio of the poly (meth) acrylic chain to the polyorganosiloxane chain can be set so that the physical properties based on each chain can be compatible. The ratio of the polyorganosiloxane chain is determined in consideration of the expression of physical properties based on this inorganic chain, the pigment dispersibility when the organic-inorganic composite resin is used for the paint, the transparency and gloss of the coating film, and the mechanical properties. It is preferable to do so. Specifically, the weight ratio of the polyorganosiloxane chain to the entire organic-inorganic composite resin is preferably 20% by weight or more and 80% by weight or less. More preferably, it is 30% by weight or more, and even more preferably 40% by weight or more. Further, it is more preferably 70% by weight or less, further preferably 60% by weight or less, and particularly preferably 50% by weight or less.

The weight average molecular weight (MW) of the organic-inorganic composite resin of the present invention can be appropriately determined according to desired physical properties, but is preferably in the range of 2,000 to 500,000, more preferably in the range of 5,000 to 300,000. In this range, the organic-inorganic composite resin can form a coating film having excellent storage stability and excellent transparency or gloss while avoiding gelation during production. The weight average molecular weight of the organic-inorganic composite resin can be determined by the method described in the section of Examples.

(Coating liquid)
The organic-inorganic composite resin of the present invention can be used as a main component of a curable resin composition for paints, that is, a coating liquid. For known paints such as pigments, plasticizers, dispersants, anti-settling agents, anti-skinning agents, desiccants, anti-dripping agents, matting agents, antistatic agents, conductive agents, flame retardants, etc. Additives can be added as appropriate. The organic-inorganic composite resin of the present invention can be used as any coating liquid, but since it has excellent weather resistance and high transparency, it is a pigment-free coating liquid for clear coatings or a coating liquid for clear coatings. It can also be suitably used as a colored coating liquid containing a pigment or dye.

The curable resin composition or coating liquid of the present invention contains a curing agent because the curing reaction of the coating film is promoted in the presence of the curing agent and the working time at the time of forming the coating film can be shortened. Alternatively, it is preferably a two-component composition or coating containing the curing agent in a separate package.

As the curing agent, a curing agent known as a curing agent used for a curable resin composition utilizing a hydrolysis reaction and a dehydration condensation reaction of a reactive silyl group can be appropriately used. Specifically, as the curing agent, the above-mentioned condensation catalyst can be used, and an organic tin compound, a titanium chelate compound, an aluminum chelate compound, an organic amine compound and the like can be used.

Specific examples of the above organic tin compounds include dioctyl tin bis (2-ethylhexyl malate), dioctyl tin oxide or a condensate of dibutyl tin oxide and silicate, dibutyl tin dioctate, dibutyl tin dilaurate, dibutyl tin distearate, and dibutyl tin diacetyl. Acetonate, dibutyltin bis (ethylmalate), dibutyltin bis (butylmalate), dibutyltin bis (2-ethylhexylmalate), dibutyltin bis (oleylmalate), stanas octoate, tin stearate, di-n- Examples include butyltin laurate oxide. Specific examples of the organotin compound having an S atom in the molecule include dibutyltin bisisononyl-3-mercaptopropionate, dioctyltin bisisononyl-3-mercaptopropionate, and octylbutyltin bisisononyl-3-mercaptopropio. Nate, dibutyltin bisisooctylthioglucolate, dioctyltin bisisooctylthioglucolate, octylbutyltin bisisooctylthioglucolate and the like can be mentioned.

Specific examples of the titanium chelate compound include titanium acetylacetonate, titaniumtetraacetylacetonate, titanium ethylacetate, titanium phosphate compound, titanium octylene glycolate, titanium ethylacetate acetate and the like.

Specific examples of the aluminum chelate compound include ethyl acetoacetate aluminum diisopropylate, aluminum tris (acetylacetone), aluminum tris (ethylacetate acetate), aluminum monoacetylacetate bis (ethylacetate acetate), and alkylacetylacetate aluminum diisopropi. The rate etc. can be mentioned.

Specific examples of the organic amine compound include triethylamine, triethylenediamine, trimethylamine, tetramethylenediamine, N-methylmorpholine, N-ethylmorpholine, N, N'-diethyl-2-methylpiperazine, laurylamine, dimethyllaurylamine and the like. Can be mentioned.

The amount of the curing agent used can be appropriately adjusted according to the curing temperature and the curing time. For example, it is preferably about 0.01 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the organic-inorganic composite resin, and is 0.1. It is more preferably about 10 parts by weight or more by weight.

The curable resin composition of the present invention can be applied to a substrate and cured to form a coating film. The conditions for coating and curing are not particularly limited, but it is preferable to use a heat source to promote the evaporation of the solvent during curing.

The thickness of the coating film formed is not particularly limited, but in the present invention, the thickness after drying is preferably 5 μm or more and 100 μm or less. If the thickness is thinner than 5 μm, the water resistance and moisture resistance of the coating film may be insufficient. If the thickness exceeds 100 μm, cracks may occur due to curing shrinkage during formation of the coating film. It is more preferably 5 μm or more and 50 μm or less, and further preferably 10 μm or more and 40 μm or less.

The base material to which the curable resin composition of the present invention can be applied is not particularly limited, and for example, an organic base material such as polycarbonate (PC), acrylic, ABS, ABS / PC, polyethylene terephthalate (PET), glass, aluminum, etc. , SUS, copper, iron, stone and other inorganic substrates can be used.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

The substances used in Examples and Comparative Examples are as follows.
Alkoxysilane component Vi (A-171: Vinyltrimethoxysilane manufactured by Momentive Performance Materials Japan LLC, molecular weight 148.2)
Me (OFS-6070: Methyltrimethoxysilane manufactured by Dow Toray Co., Ltd., molecular weight 136.2)
Ph (Z-6124: Phenyltrimexisilane manufactured by Dow Toray Co., Ltd., molecular weight 198.3)
MA (A-174: Momentive Performance Materials Japan GK, 3-methacryloyloxypropyltrimethoxysilane, molecular weight 248.4)
Ge (OFS-6040: manufactured by Dow Toray Co., Ltd., 3-glycidyloxypropyltrimethoxysilane, molecular weight 236.3).

Condensation catalyst DBP (manufactured by Johoku Chemical Industry Co., Ltd., dibutyl phosphate, molecular weight 210.2).
MgCl ₂ (manufactured by Tokyo Kasei Co., Ltd., magnesium chloride hexahydrate, molecular weight 203.3).
LiCl (manufactured by Tokyo Kasei Co., Ltd., lithium chloride, molecular weight 42.4).

(Meta) Acrylic resin raw material monomer and radical polymerization initiator MMA (manufactured by Mitsubishi Gas Chemical Company, Inc., methyl methacrylate, molecular weight 100.1)
TSMA (A-174: Momentive Performance Materials Japan LLC, 3-methacryloyloxypropyltrimethoxysilane, molecular weight 248.4)
BA (manufactured by Nippon Shokubai Co., Ltd., butyl acrylate, molecular weight 128.2)
CHMA (manufactured by Nippon Shokubai Co., Ltd., cyclohexyl methacrylate, molecular weight 168.0)
BMA (manufactured by Mitsubishi Gas Chemical Company, Inc., butyl methacrylate, molecular weight 142.2)
AA (manufactured by Nippon Shokubai Co., Ltd., acrylic acid, molecular weight 72.1)
HEMA (manufactured by Nippon Shokubai Co., Ltd., 2-hirodoxyethyl methacrylate, molecular weight 130.1)
St (manufactured by Sankyo Chemical Co., Ltd., styrene, molecular weight 104.2)
V59 (manufactured by Wako Pure Chemical Industries, Ltd., 2,2'-azobis (2-methylbutyronitrile), molecular weight 192.3).

Dehydrating agent MOA (manufactured by Tokyo Chemical Industry Co., Ltd., trimethyl orthoformate, molecular weight 106.1).

Solvent S100 (manufactured by Sanwa Chemical Co., Ltd., mineral oil, cumene, xylene, trimethylbenzene mixture)
LAWS (Mineral Spirit, Xylene, Trimethylbenzene, Nonane Mixture, manufactured by Shell Chemicals Japan Co., Ltd.)
PMA (manufactured by Sankyo Chemical Co., Ltd., propylene glycol monomethyl ether acetate, molecular weight 132.2)

Stabilizer AcAc (manufactured by Daicel Corporation, acetylacetone, molecular weight 100.1)
Curing catalyst U-20 (manufactured by Nitto Kasei Co., Ltd., dibutyltin dilaurate, 631.6)

(Polysiloxane reaction time)
After mixing the alkoxysilane component, the condensation catalyst, and water at room temperature, the mixture is heated in an oil bath heated to 90 ° C., and the reaction start point is when the internal temperature reaches 70 ° C. Then, the reaction time was defined as the time of heating in an oil bath at 90 ° C., and the reaction was carried out for 6 hours.

(Dealcohol in polysiloxane synthesis)
As described above, the resin solution obtained by reacting for 6 hours is composed of polysiloxane, alcohol generated in the reaction process, and a small amount of residual water. In order to remove volatile components other than polysiloxane by distillation, the resin solution is heated with an oil bath heated to 120 ° C. and slightly pressurized with nitrogen to obtain the set content liquid amount while measuring the recovered liquid amount. Distillation continued until.

The amount of alcohol that needs to be removed by distillation was calculated according to the following formula.
(When the condensation catalyst is DBP or MgCl ₂ ) Amount of added water x 32/18 x 2 x 85%
(When the condensation catalyst is LiCl) Amount of added water x 32/18 x 2 x 100%

The total weight of alcohol that can be generated was calculated assuming that 1 mol of alcohol is generated with respect to 1 mol of the alkoxysilyl group contained in the alkoxysilane component used in the reaction. For example, 1 mol of a trimethoxysilicate group has 3 mol of a methoxysilyl group and generates 3 mol of methanol, and 1 mol of a methyldimethoxysilyl group has 2 mol of a methoxysilyl group and generates 2 mol of methanol. To do. In addition, 1 mol of water produces 1 mol to 1 mol of silanol groups and 1 mol of alcohol of an alkoxysilyl group. Further, 1 mol of silanol group generated reacts with 1 mol of alkoxysilyl group to generate 1 mol of alcohol. That is, 2 mol of alcohol is generated from 1 mol of water. There is a difference in the progress of this reaction depending on the condensation catalyst, and LiCl progresses 100%, whereas DBP and MgCl ₂ progress only about 85%. Therefore, in consideration of this point, the calculation formula is as described above. Corrected.

(Synthesis of Polyorganosiloxane of Example 1)
Put 4.7 g of vinyltrimethoxysilane, 79.7 g of methyltrimethoxysilane, 0.0042 g of dibutyl phosphate, and 12.7 g of pure water in a 300 ml volume 4-necked flask equipped with a cooling tube, and use an oil bath set at 90 ° C. It was heated and reacted for 6 hours. Methanol produced by hydrolysis was refluxed in the flask, and the internal temperature became about 67 ° C. Then, the distillation apparatus was recombined while heating while being careful not to substantially lower the internal temperature, and the generated methanol and residual water were removed to obtain 59.2 g of a polysiloxane solution. When recombining with a distillation apparatus, avoid mixing oxygen as much as possible by installing a nitrogen immigration pipe and pressurizing nitrogen, carry out under nitrogen bubbling conditions during distillation, and substantially during radical polymerization after distillation and thereafter. The condition that almost no oxygen was present was maintained.

For Examples 2 to 39 and Comparative Examples 1 to 5, a polysiloxane solution was obtained in the same manner as in Example 1 except that the alkoxysilane component, the condensation catalyst, and water were used according to the description in Table 1. In Table 1, the unit of the blending amount of each component is gram (g).

(Equivalent amount of radical reactive functional groups)
The radical reactive functional group equivalent was calculated by the following formula.
(Molecular weight of alkoxysilane having radical-reactive functional group-Molecular weight of structure desorbed from alkoxysilane by hydrolysis / dehydration condensation reaction) ÷ (Akoxysilane having radical-reactive functional group with respect to the total amount of alkoxysilane component used) Mol%)

As an example, a method for calculating the equivalent amount of radical-reactive functional groups will be described below for Example 1. "Molecular weight of alkoxysilane having a radical reactive functional group-molecular weight of structure desorbed from alkoxysilane by hydrolysis / dehydration condensation reaction" is 148.23-69 = 79.23. The number of moles of vinyltrimethoxysilane used is 4.7 ÷ 148.23 = 0.0317, and the number of moles of methyltrimethoxysilane used is 79.7 ÷ 136.22 = 0.585. From the above, the radical reactive functional group equivalent amount is calculated as 79.23 ÷ (0.0317 ÷ (0.0317 + 0.585)) ≈1542.

The reason why "the molecular weight of the structure desorbed from alkoxysilane by hydrolysis / dehydration condensation reaction" is set to "69" in the above formula is as follows. Trimethoxysilane: In -Si (OCH ₃ ) ₃ , when all the methoxy groups form a siloxane bond by the condensation reaction, the structure represented by -Si (O _0.5 ) _3- is formed. Correspondingly, the structure desorbed by the hydrolysis / dehydration condensation reaction is represented by (O _0.5 CH ₃ ) ₃ , and its molecular weight is “69”.

(Weight average molecular weight)
The weight average molecular weight of polyorganosiloxane was measured by GPC. GPC was carried out using HLC-8320GPC manufactured by Toso Co., Ltd. as a liquid feeding system, TSK-GEL H type manufactured by Toso Co., Ltd. as a column, and THF as a solvent, and the weight average molecular weight was calculated in terms of polystyrene. However, in Table 1, it is shown as the IP molecular weight.

(Synthesis of composite resin)
From the above distillation apparatus, the cooling pipe was changed and the apparatus was rearranged so as to reflux. The oil bath was set so that the internal temperature became 110 ° C. while flowing nitrogen gas, and the "initial solvent" in Table 2 was added to the polysiloxane solution obtained above to set the internal temperature to 110 ° C.

Separately from the above 4-neck flask, "AC composition monomer" + "radical generator" + "polymerization solvent" in Table 2 was added to a brown bottle to prepare a monomer solution for adding a pump. The prepared monomer solution was added dropwise to the four-necked flask over 3 hours using a diaphragm pump.

In order to consume the residual monomer, add the "radical generator for residual monomer" + "polymerization solvent for residual monomer" in Table 2 to a brown bottle to prepare a radical generator solution for residual monomer, and use a pump to prepare 1 It was added dropwise to the reaction solution over time. After completion of the dropping, the mixture was further heated for 1 hour to obtain the desired composite resin solution. Specifically, it is as follows.

(Synthesis of Composite Resin of Example 1)
To the 59.2 g of the polysiloxane solution obtained in the synthesis of the polyorganosiloxane of Example 1 described above, 19.7 g of S100 and 46.1 g of LAWS were added and heated so that the internal temperature became 110 ° C.
MMA 5.0 g, TSMA 1.0 g, BA 3.0 g, BMA 41.0 g, V59 2.0 g, S100 2.5 g, and LAWS 5.9 g were mixed in a brown bottle, and a pump was added over 3 hours.
Further, a solution consisting of 0.2 g of V59, 5.6 g of S100, and 13.1 g of LAWS was added to the pump over 1 hour, and further heated for 1 hour to obtain 204.4 g of a composite resin solution. In the obtained composite resin, the carbon atom in the monomer unit constituting the poly (meth) acrylic chain and the silicon atom in the polyorganosiloxane chain are bonded via only an ethylene group, and the polyorganosiloxane chain is formed. It has a reactive silicon group.

In Examples 2 to 39 and Comparative Examples 1 to 5 in Table 2, the polysiloxane solutions, solvents, monomers, and radicals generated in Examples 2 to 39 and Comparative Examples 1 to 5 in Table 1 were generated according to the description in Table 2. A composite resin solution was obtained in the same manner as in the above-mentioned "Synthesis of composite resin of Example 1" except that the agent was used. However, in Comparative Examples 2 to 5, gelation occurred in the polymerization process of the (meth) acrylic acid ester monomer, and the composite resin could not be produced. In Examples 25 and 26, a dehydrating agent was added to the obtained composite resin solution according to the description in Table 2, and in Examples 37 to 39, a stabilizer was added together with the initial solvent according to the description in Table 2. did. In Table 2, the unit of the blending amount of each component is gram (g).

(IP amount)
The IP amount is the weight ratio of the total amount of the polyorganosiloxane to the total amount of the polyorganosiloxane formed by hydrolysis and dehydration condensation of the alkoxysilane component and the total amount of the radically polymerizable monomer component.

(Weight average molecular weight)
The weight average molecular weight of the organic-inorganic composite resin was measured by GPC. GPC was carried out using HLC-8320GPC manufactured by Tosoh Corporation as a liquid feeding system, TSK-GEL H type manufactured by Tosoh Corporation as a column, and THF as a solvent, and the weight average molecular weight was calculated in terms of polystyrene. did.

( ²⁹ Si-NMR)
The structural units derived from the monoorganotrialkoxysilane are the structural unit T1 forming one siloxane bond, the structural unit T2 forming two siloxane bonds, and the structural unit T2 forming three siloxane bonds. It is classified into the unit T3. ²⁹ Si-NMR of the organic-inorganic composite resin was measured using AVANCE III HD500 manufactured by BRUKER, and the peak area ratio derived from each obtained structure was determined by the moles of the T1, T2, and T3 structures contained in the organic-inorganic composite resin. It was a ratio.

(Siloxane bond formation rate)
When the molar ratios of the T1, T2, and T3 structures are X, Y, and Z,
Formula: (1 x X + 2 x Y + 3 x Z) / 3
The value calculated by the above was taken as the siloxane bond formation rate (condensation rate).

(Storage stability of composite resin solution)
Two bottles of the obtained composite resin solution sealed in a closed glass bottle were prepared. One was placed in a dryer at 50 ° C. for 4 weeks, and the other was stored in a thermostatic chamber controlled at 23 ° C. for the same period, and the viscosity of the composite resin solution after 4 weeks was visually evaluated. The results are shown in Table 2.
A: No change in viscosity to less than 10 times thickening by visual estimation, B: 10 times or more thickening by visual estimation, C: Gelation

(Preparation and painting of clear coating liquid)
A clear coating solution is prepared by mixing 10.0 g of the composite resin solution obtained in each Example and Comparative Example with 0.050 g of the organic tin compound U-20 as the curing catalyst and 0.050 g of S-100 as the diluting solvent. did.

The prepared clear coating liquid is coated on a 70 × 150 × 2 mm float glass plate and a 50 × 150 × 1 mm black ABS plate with a 6 mil applicator, and a dry clear coating film having a thickness of about 0.076 mm is applied. Obtained.

(Transparency of clear coating film)
After applying the clear coating film on a glass plate and curing it in a thermostatic chamber adjusted to 23 ° C for one week, the clear coating film is used with the simultaneous color and turbidity measuring device COH400 (manufactured by Nippon Denshoku Industries Co., Ltd.). The haze value of was measured and evaluated. The results are shown in Table 2.
A: No turbidity (haze value <5), B: Turbidity (haze value ≥ 5)

(Gloss of clear coating film)
After coating the clear coating liquid on a black ABS plate and curing it in a thermostatic chamber adjusted to 23 ° C. for 1 week, the gloss value of the clear coating film at 60 ° was measured and evaluated using a gloss meter. The results are shown in Table 2.
A: 60 or more, B: less than 60

(Tack free time)
After applying the clear coating film on a glass plate, it is cured in a thermostatic chamber adjusted to 23 ° C, and the time until the stickiness is not felt when the index finger is lightly pressed against the surface of the clear coating film and released is measured. did. Immediately after painting is the starting point. The results are shown in Table 2.

(Gel)
A 0.1 mm thick aluminum sheet is cut with scissors to a size of 2.5 x 2.5 x 0.1 mm, 0.2 g of clear coating film is dropped onto it, and in a constant temperature room adjusted to 23 ° C. After curing for 1 week, it was immersed in an acetone bath, and the gel content was calculated from (insoluble content weight) ÷ (coating film weight) × 100. When soaking in an acetone bath, it was soaked in a bag made of a 200-mesh wire mesh to separate and recover the insoluble and eluted components. The results are shown in Table 2.

As can be seen from Table 2, the composite resin obtained in each example had good storage stability, and the transparency and gloss of the clear coating film obtained by using the composite resin were both good. On the other hand, in Comparative Example 1, the transparency and gloss of the clear coating film were both insufficient. Further, in Comparative Examples 2 to 5, gelation occurred and the composite resin could not be produced.

(Making white enamel paint)
Titanium oxide fine particles were dispersed in the composite resin solutions obtained in Comparative Examples 1 and 9 to 12, 15, 16, 21, 25, and 27 to 39 to obtain a resin solution for white enamel paint. BYK-142 was added as a dispersant to help disperse titanium oxide, MOA was added as a dehydrating agent to remove water derived from titanium oxide, and glass beads were used to crush the agglomeration of titanium oxide fine particles. There was.

First, a mill base was prepared by mixing with a small amount of composite resin solution so that the titanium oxide fine particles were easily dispersed so as to have a high concentration. Then, an additional composite resin solution was added and diluted to obtain a white enamel paint. Specifically, it is as follows.

[Mill base]
In a 225 ml volume of mayonnaise bottle, according to the description of "Mill base" in Table 3, 30.15 g of the composite resin solution, 33.50 g of titanium oxide, 0.56 g of the dispersant, 0.50 g of the dehydrating agent, as a diluting solvent. A mill base was obtained by adding 0.35 g of S100, 0.15 g of Laws, and 50 g of glass beads and vibrating at high speed for 2 hours using a paint conditioner.

[Cutback]
Then, according to the description of "cutback" in Table 3, 70.35 g of the composite resin solution, 3.2 g of S100 and 1.37 g of LAWS as the diluting solvent were added, and the white enamel paint 140 was vibrated at high speed for 30 minutes with a paint conditioner. .1 g (excluding the weight of glass beads) was obtained.

(Storage stability of white enamel paint)
Two bottles of the obtained white enamel paint enclosed in a sealed glass bottle were prepared. One was placed in a dryer at 50 ° C. for 4 weeks, and the other was stored in a thermostatic chamber controlled at 23 ° C. for the same period, and the viscosity of the paint after 4 weeks was visually evaluated. The results are shown in Table 3.
A: No change in viscosity to less than 10 times thickening by visual estimation, B: 10 times or more thickening by visual estimation, C: Gelation

(Creation and painting of white enamel coating liquid)
A white enamel coating solution to which a curing catalyst was added by mixing 10.0 g of the obtained white enamel paint with 0.060 g of an organic tin compound U-20 as a curing catalyst and 0.060 g of S-100 as a diluting solvent. Was produced.
The prepared white enamel coating solution containing a curing catalyst was coated on a 70 × 150 × 2 mm float glass plate with a 6 mil applicator to obtain a dry white enamel coating film having a thickness of about 0.090 mm.

(Gloss of white enamel coating)
After applying the white enamel coating film on a glass plate and curing it in a thermostatic chamber adjusted to 23 ° C. for 1 week, the gloss value of the white enamel coating film at 60 ° was measured and evaluated using a gloss meter. .. The results are shown in Table 3.
A: 60 or more, B: 55 or more and less than 60, C: 55 or less

As can be seen from Table 3, the white enamel coating film obtained in each example had good storage stability, and the white enamel coating film obtained using this had good gloss. In particular, the white enamel coating film obtained in Examples 31-33 had the best appearance, good pigment dispersibility, and good toning property.

Claims

Monoorganotrialkoxysilanes and / or diorganodialkoxysilanes (a-1) having radical-reactive functional groups that exhibit radical reactivity lower than the growth reactivity of methacryloyl groups in radical polymerization, and radical-reactive functional groups. Monoorganotrialkoxysilanes and / or diorganodialkoxysilanes (a-2) that do not have,
A step of hydrolyzing and dehydrating and condensing a alkoxysilane component containing water in the presence of water and a condensation catalyst to obtain a polyorganosiloxane, and in the presence of the polyorganosiloxane, a (meth) acrylic acid ester monomer is contained. Including the step of radically polymerizing a radically polymerizable monomer component.
The radical-reactive functional group exhibiting a radical reactivity lower than the growth reactivity of the methacryloyl group in the radical polymerization contains at least a vinyl group.
The ratio of (a-2) to the total of (a-1) and (a-2) is 70% by weight or more and 99% by weight or less, and 50% by weight of the organic group contained in (a-2). % Or more is at least one selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.
The radically reactive functional group equivalent amount calculated from the alkoxysilane component is in the range of 280 or more and less than 5000.
The amount of water added is 30 mol% or more and 60 mol% or less with respect to 100% of the total number of moles of alkoxy groups directly bonded to silicon atoms contained in the alkoxysilane component.
A method for producing an organic-inorganic composite resin containing a poly (meth) acrylic chain and a polyorganosiloxane chain.
The method for producing an organic-inorganic composite resin according to claim 1, wherein 50% by weight or more of the organic group contained in (a-2) is a methyl group.
The organic according to claim 1 or 2, wherein the ratio of the monoorganotrialkoxysilane having a vinyl group and / or the diorganodialkoxysilane to the whole alkoxysilane component is 2% by weight or more and 30% by weight or less. A method for producing an inorganic composite resin.
The production method according to any one of claims 1 to 3, wherein a polyorganosiloxane having a reactive silicon group is obtained by the hydrolysis and dehydration condensation reaction.
The production method according to any one of claims 1 to 4, wherein the weight ratio of the polyorganosiloxane chain to the entire organic-inorganic composite resin is 20% by weight or more and 80% by weight or less.
The production method according to any one of claims 1 to 5, wherein the temperature is controlled so that the temperature of the reaction system does not substantially decrease from the hydrolysis and dehydration condensation reaction to the end of the radical polymerization.
The production method according to any one of claims 1 to 6, wherein the radical polymerization is carried out in the presence of a β-dicarbonyl compound.
The production method according to any one of claims 1 to 7, wherein the hydrolysis and dehydration condensation reaction and the radical polymerization are carried out in an atmosphere substantially free of oxygen molecules.
An organic-inorganic composite resin containing a poly (meth) acrylic chain and a polyorganosiloxane chain bonded to the poly (meth) acrylic chain.
The weight ratio of the polyorganosiloxane chain to the entire organic-inorganic composite resin is 20% by weight or more and 80% by weight or less.
The polyorganosiloxane chain is a hydrolysis condensate of an alkoxysilane component containing 70 to 100 mol% of monoorganotrialkoxysilane and 30 to 0 mol% of diorganodialkoxysilane.
The polyorganosiloxane chain has a reactive silicon group and has
The carbon atom in the monomer unit constituting the poly (meth) acrylic chain and the silicon atom in the polyorganosiloxane chain are bonded via only a hydrocarbon group.
The hydrocarbon group contains at least an ethylene group and contains
Of the total of the monoorganotrialkoxysilane and the diorganodialkoxysilane, the proportion of the monoorganotrialkoxysilane and / or the diorganodialkoxysilane (a-2) having no radically reactive functional group is 70. Organic, which is at least 99% by weight and 50% by weight or more of the organic group contained in (a-2) is at least one selected from the group consisting of a methyl group, an ethyl group, and a phenyl group. Inorganic composite resin.
The structural unit derived from the monoorganotrialkoxysilane forms a structural unit T1 forming one siloxane bond, a structural unit T2 forming two siloxane bonds, and three siloxane bonds. Classified into the structural unit T3, the ratio (%) of the number of moles of T1, T2, and T3 to the total number of moles of T1, T2, and T3 measured by 29 Si-NMR was set to X, Y, and Z, respectively. At the time, the following formula:
(1 x X + 2 x Y + 3 x Z) / 3
The organic-inorganic composite resin according to claim 9, wherein the siloxane bond formation rate calculated by the above method is 60% or more and 80% or less.
The organic-inorganic composite resin according to claim 9 or 10, wherein the solubility parameter value (SP value) of the poly (meth) acrylic chain is 9.0 to 11.0 (cal / cm 3 ) 1/2 .
A curable resin composition containing the organic-inorganic composite resin according to any one of claims 9 to 11.
A cured product obtained by curing the curable resin composition according to claim 12.