JP2001310916A - Polymerizable resin composition and production method of the same, and its cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radical polymerizable resin composition which can be controlled the molecular weight according to the application, and can be used a low skin stimulative polymerizable monomer as a diluent, and is easily curable in the presence of oxygen, and to provide a production method of the same and its cured product. SOLUTION: The polymerizable resin composition contains a (meta)acrylate polymer (A), a polymerizable monomer shown by the formula (1) and/or the formula (2), and a vinyl ether. (In the formula (1) and formula (2), R1-R4 is H or a 1-12C alkyl group and/or an alicyclic alkyl group even if each may be the same or the different. If R1-R4 is hydrogen, it may be the either form of salt of univalent metallic salt, divalent metallic salt, phosphate, ammonium salt or organic amine salt).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polymerizable resin composition and a method for producing the same. More specifically, the present invention relates to a method for producing a polymerizable resin composition that can be used as a paint, an adhesive, a molding material, an ink, and the like.

[0002]

2. Description of the Related Art As radical polymerizable resins, unsaturated polyester resins and vinyl ester resins are known as typical ones. These polymerizable resins are properly used in each application depending on their characteristics and physical properties, and are industrially useful materials.

However, when various properties are required, it is often necessary to improve existing disadvantages.
For example, most of the above resins have a number average molecular weight of about several hundreds to 2,000 such as oligomers and prepolymers, and are unsuitable for applications requiring higher molecular weight polymers.

[0004] On the other hand, (meth) acrylate polymers have a high degree of freedom in molecular weight design, but when produced by bulk polymerization, it is necessary to stop the reaction during the polymerization, and the diluent is also changed to (meth) acrylate. Limited. In addition, there remains a problem in curability in the presence of oxygen. Further, (1) a resin composition having a malate group in a side chain of a polymer of the resin composition produced by the bulk polymerization, and (2) a polymer produced by solution polymerization, and then devolatilized, ) A resin composition obtained by diluting a polymer having an acryloyl group in a side chain with an acrylate monomer is also known. However, the resin composition obtained by any of the methods (1) and (2) has a diluent. It is a (meth) acrylate monomer and has a major problem that its curability in the presence of oxygen is insufficient.

[0005] Further, the production method (1) is always in danger of gelling or runaway of the reaction due to bulk polymerization. In addition, the manufacturing method (2) requires complicated steps, and there is a problem in terms of process and energy.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to control various molecular weights in accordance with the intended use, to easily produce a product using a vinyl ether as a diluent, and to obtain a product in the presence of oxygen. It is an object of the present invention to provide a polymerizable resin composition having excellent curability, its use, and its cured product.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, in the present invention, a (meth) acrylate polymer (A) and a polymerizable monomer represented by the following general formulas (1) and / or (2) are used. (B) and a polymerizable resin composition containing a vinyl ether (C). General formula (1):

[0008]

Embedded image

General formula (2):

[0010]

Embedded image

(In the above general formulas (1) and (2), R ¹ Ｒ
R ⁴ is hydrogen or an alkyl group having 1 to 12 carbon atoms and / or
Alternatively, they are alicyclic alkyl groups, which may be the same or different. When R ^{1 to} R ⁴ are hydrogen, they may be in the form of any of a monovalent metal salt, a divalent metal salt, a phosphate, an ammonium salt and an organic amine group salt. )Also,
More preferably, the structure of the above general formulas (1) and (2) is not a salt structure, that is, the general formulas (1) and (2)
Wherein R ^{1 to} R ⁴ are hydrogen or an alkyl group having 1 to 12 carbon atoms and / or an alicyclic alkyl group, which may be the same or different.

In the present invention, the efficiency as a polymerization solvent, workability, and physical properties of the polymerizable resin composition when contained in the polymerizable resin composition (viscosity and polymerizability: a side reaction with vinyl ethers may occur) From the viewpoint of the above, it is a more preferred embodiment that the structure of the general formulas (1) and (2) is not a salt structure as described above.

The above (meth) acrylate polymer (A)
However, by having a polymerizable double bond at the terminal and / or the side chain, a polymerizable resin composition more preferable in terms of curability and the like can be obtained.

More specifically, the polymerizable double bond is at least one polymerizable double bond selected from the group consisting of a malate group, a fumarate group, and a (meth) acryloyl group. is there. In another embodiment of the present invention, the (meth) acrylate polymer (A) is subjected to radical polymerization in a polymerizable monomer (B) represented by the following general formulas (1) and / or (2). And a method for producing a polymerizable resin composition, which comprises mixing a polymerizable monomer (D). General formula (1):

[0015]

Embedded image

General formula (2):

[0017]

Embedded image

(In the above general formulas (1) and (2), R ¹ to
R ⁴ is hydrogen or an alkyl group having 1 to 12 carbon atoms and / or
Alternatively, they are alicyclic alkyl groups, which may be the same or different. When R ^{1 to} R ⁴ are hydrogen, they may be in the form of any of a monovalent metal salt, a divalent metal salt, a phosphate, an ammonium salt and an organic amine group salt. Further, more preferably, the structure of the above general formulas (1) and (2) is not a salt structure, that is, in the general formulas (1) and (2), R ^{1 to} R ⁴ are hydrogen or carbon number. This is the case where 1 to 12 alkyl groups and / or alicyclic alkyl groups are the same or different.

In the present invention, the efficiency as a polymerization solvent, the workability, and the physical properties of the polymerizable resin composition when included in the polymerizable resin composition (viscosity and polymerizability: the possibility of side reactions with vinyl ethers From the viewpoint of the above, the case where the structures of the general formulas (1) and (2) are not a salt structure as described above is a more preferred embodiment.

More specifically, the raw material monomer component for producing the (meth) acrylate polymer (A) is a polymerizable monomer represented by the above general formula (1) and / or (2). This is a method for producing a polymerizable resin composition, which comprises mixing a polymerizable monomer (D) after radical polymerization in the body (B).

In the embodiments of the present invention, various uses of the polymerizable resin composition obtained by the present invention and cured products thereof are preferred embodiments.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically. The polymerizable resin composition of the present invention comprises a (meth) acrylate polymer (A), a polymerizable monomer (B) represented by the general formula (1) and / or the general formula (2), and A polymerizable resin composition comprising a vinyl ether (C). Although the content of the above three components is not particularly limited, it is preferable to produce the polymerizable resin composition of the present invention by adopting a content in a specific range described later. Further, the (meth) acrylate polymer (A)
May be a thermoplastic resin such as PMMA obtained by polymerization using MMA as a monomer component, but in a more preferred form as a polymerizable resin composition,
It is preferable that the (meth) acrylate polymer (A) is a polymer having a polymerizable double bond at a terminal and / or a side chain. That is, in a preferred embodiment of the present invention, the (meth) acrylate polymer (A) is a thermosetting resin.

In the composition of the present invention, the (meth) acrylate polymer (A) is not particularly limited as long as it is produced by polymerizing various (meth) acrylate monomers. In order to obtain sufficient properties as a resin, at least one double bond selected from the group consisting of a maleate group, a fumarate group and a (meth) acryloyl group is provided at the terminal and / or the side chain of the polymer. It is preferable to use a (meth) acrylate polymer (A1) having at least one of terminal and / or side chains of a malate group and / or a fumarate group in consideration of curability in the presence of oxygen. preferable. More specifically, the term "curability in the presence of oxygen" refers to, for example, physical properties such as air-drying property of the coating film surface when the resin composition of the present invention is cured.

The method for producing the (meth) acrylate polymer (A) having a polymerizable double bond at a terminal and / or a side chain, which is the component (A) used in the polymerizable resin composition of the present invention, is as follows: There is no particular limitation. In a more preferred embodiment of the present invention, the polymerizable double bond is a malate group,
The production form will be described below, taking as an example the case of at least one double bond selected from the group consisting of a fumarate group and a (meth) acryloyl group.

For example, as a method for producing a (meth) acrylate polymer (A1) having a maleate group and / or a fumarate group at a terminal and / or a side chain, which can be used for the polymerizable resin composition of the present invention, Although not particularly limited, the following two methods are exemplified.

In the first method, a (meth) acrylate polymer (a) having at least one hydroxyl group in one molecule is used.
This is a method of reacting 1) with maleic anhydride. A malate group is generated by the reaction between the hydroxyl group and the maleic anhydride, and the malate group may be converted into a fumarate group by fumaric acid transfer.

The second method comprises a (meth) acrylate polymer (a2) having at least one epoxy group in one molecule, a maleic acid half ester, a fumaric acid half ester, and a maleic anhydride. And a compound having one alcoholic hydroxyl group in one molecule, specifically, a mixture of maleic anhydride and a compound having one alcoholic hydroxyl group in one molecule. And introducing a malate group and / or a fumarate group into the side chain of the polymer. A malate group and / or a fumarate group are generated by the reaction between the epoxy group and the above-mentioned, and the malate group may be converted into a fumarate group by fumaric acid transfer.

<Regarding the First Method> The (meth) acrylate polymer (a1) having at least one hydroxyl group in one molecule is not particularly limited, and the hydroxyl group may be added to the terminal and / or side of the polymer. What is necessary is just to have in a chain, but it is preferable that the (meth) acrylate type monomer which has at least one hydroxyl group in one molecule is used as an essential component.

As the (meth) acrylate monomer having at least one hydroxyl group in one molecule, for example, 2- (meth) acrylate monomer
Such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (α-hydroxymethyl) ethyl acrylate, 2-hydroxyethyl (meth) acrylate-modified lactone, and (meth) acrylic acid-modified polyethylene glycol; (Meth) acrylate monomers and the like. These (meth) acrylate monomers having at least one hydroxyl group in one molecule may be used alone or in combination of two or more.

The (meth) acrylate polymer (a1) used in the present invention has, as a main structural component, a (meth) acrylate monomer unit having at least one hydroxyl group in one molecule. However, other structural units may be included in the structural unit. Examples of other monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid, and (meth) )
(Meth) acrylate monomers having no hydroxyl group and / or epoxy group such as acrylamide. These other monomers may be used alone or in combination of two or more. The (meth) acrylate-based polymer is a polymer obtained by polymerizing these monomer components.

(Meth) acrylate polymer (a1)
Among them, the ratio of the (meth) acrylate-based monomer unit having at least one hydroxyl group in one molecule is not particularly limited, but is more preferably 20 to 70 mol%.

When the (meth) acrylate polymer (a1) having at least one hydroxyl group in one molecule is reacted with maleic anhydride, the amount of maleic anhydride used is as follows. It is preferably from 20 to 100 mol%, more preferably from 40 to 100 mol%, based on the hydroxyl groups of the polymer (a1).

Further, the (meth) acrylate polymer (A) produced by the above-mentioned first method and used in the present invention.
1) has a carboxyl group derived from maleic anhydride at its terminal and / or side chain, and various functional groups may be further modified with a compound capable of reacting with the carboxyl group.

Compounds capable of reacting with a carboxyl group include compounds having an epoxy group, compounds having a hydroxyl group,
A compound having an amino group, a compound having a vinyl ether group, and the like can be given. Examples of the compound having an epoxy group include compounds having an alkyl or phenyl group such as butyl glycidyl ether and phenyl glycidyl ether, and bisphenol type epoxy such as bisphenol A diglycidyl ether and bisphenol F diglycidyl ether. Compounds, glycol-type epoxy compounds such as triethylene diglycidyl ether,
Epoxy compounds having a (meth) acryloyl group such as glycidyl (meth) acrylate and (3,4-oxycyclohexyl) methyl (meth) acrylate, and epoxy compounds having an allyl group such as allyl glycidyl ether are exemplified.

The above-mentioned compound having a hydroxyl group includes
Examples thereof include alkyl alcohols such as methyl alcohol, ethyl alcohol and butyl alcohol, glycols such as ethylene glycol, and hydroxyl group compounds having a (meth) acryloyl group such as hydroxyethyl (meth) acrylate. As the compound having an amino group,
Examples thereof include alkylamine compounds such as (di) methylamine, (di) ethylamine, and (di) butylamine.
Examples of the compound having a vinyl ether group include methyl vinyl ether, ethyl vinyl ether, alkyl vinyl ethers such as butyl vinyl ether, triethylene glycol divinyl ether, and polyfunctional vinyl ethers such as cyclohexane dimethanol divinyl ether. Or two or more of them may be used in combination.

When a compound having two or more functional groups capable of reacting with a carboxyl group is used among these compounds, gelation may occur during the reaction.

In consideration of the cured form of the present invention among these compounds, it is preferable to use a compound having an allyl group and / or a (meth) acryloyl group. Among them, allyl glycidyl ether, glycidyl (meth) acrylate, (3) , 4-Oxycyclohexyl) methyl (meth) acrylate is more preferred. The amount of these compounds used is preferably 80 to 100 mol% based on the carboxyl groups.

<Regarding the Second Method> The above-mentioned (meth) acrylate polymer (a2) having at least one epoxy group in one molecule is not particularly limited, and the epoxy group of the polymer is not particularly limited. What is necessary is just to have at the terminal and / or the side chain, but it is preferable to use a (meth) acrylate monomer having at least one epoxy group in one molecule as an essential component.

The above (meth) acrylate monomers having at least one epoxy group in one molecule include:
For example, glycidyl (meth) acrylate, (3,4-oxycyclohexyl) methyl (meth) acrylate and the like can be mentioned. These (meth) acrylate monomers having at least one epoxy group in one molecule may be used alone or in combination of two or more.

The above (meth) acrylate polymer (a)
2) may have a (meth) acrylate monomer unit having at least one epoxy group in one molecule, but may contain another monomer unit. As the other monomers, the monomers exemplified in the first method can be similarly mentioned. These other monomers may be used alone or in combination of two or more.

The (meth) acrylate polymer (a)
In 2), the ratio of the (meth) acrylate monomer unit having at least one epoxy group in one molecule is not particularly limited, but is more preferably 20 to 70 mol%.

As the maleic acid half ester used in the second method, monomethyl maleate, monobutyl maleate and the like can be mentioned. Examples of fumaric acid half ester include monomethyl fumarate and monobutyl fumarate. These maleic acid half esters or fumaric acid half esters may be used alone or in combination of two or more.

In the second method, examples of the compound having maleic anhydride and one alcoholic hydroxyl group in one molecule include methanol and n-butanol. These compounds having one alcoholic hydroxyl group in one molecule may be used alone or in combination of two or more.

(Meth) acrylate polymer (a2) having at least one epoxy group in one molecule, maleic acid half ester, fumaric acid half ester, maleic anhydride and one alcohol in one molecule A reaction with at least one selected from the group consisting of maleic anhydride and a mixture of compounds having one alcoholic hydroxyl group in one molecule. The amount of maleic acid half ester, fumaric acid half ester, or maleic anhydride used is preferably 20 to 100 with respect to the epoxy group of the (meth) acrylate polymer (a2).
Mol%, preferably 40 to 100 mol%. The amount of the compound having one alcoholic hydroxyl group in one molecule is preferably from 80 to 120 mol%, more preferably from 95 to 105 mol%, based on maleic anhydride. preferable.

The method for producing the (meth) acrylate polymer (A1) having a (meth) acryloyl group at the terminal and / or the side chain of the polymer as the polymerizable double bond is not particularly limited, but may be further There are the following two methods.

The third method comprises a (meth) acrylate polymer (a3) having at least one carboxyl group in one molecule and a (meth) acrylate polymer having one epoxy group in one molecule. It is a method of reacting with a monomer.

The fourth method comprises a (meth) acrylate polymer (a4) having at least one epoxy group in one molecule and a (meth) acrylate polymer having one carboxyl group in one molecule. It is a method of reacting with a monomer.

<Regarding the Third Method> The (meth) acrylate polymer (a3) having at least one carboxyl group in one molecule is not particularly limited, and the carboxyl group may be added to the terminal of the polymer and / or Alternatively, any one may be used as long as it has a side chain, but a (meth) acrylate monomer having at least one carboxyl group in one molecule is preferably used as an essential component.

The (meth) acrylate monomer having at least one carboxyl group in one molecule includes, for example, (meth) acrylate monomers such as (meth) acrylic acid. These (meth) acrylate monomers having at least one carboxyl group in one molecule may be used alone or in combination of two or more.

The (meth) acrylate polymer (a)
3) may have a (meth) acrylate-based monomer unit having at least one carboxyl group in one molecule, but may have another monomer unit in its structure. . As the other monomers, the monomers exemplified in the first method can be similarly mentioned. These other monomers may be used alone or in combination of two or more.

Examples of the (meth) acrylate monomer having one epoxy group in one molecule include the monomers exemplified in the second method. These other monomers may be used alone or in combination of two or more.

The (meth) acrylate polymer (a)
In 3), the ratio of the (meth) acrylate monomer unit having at least one carboxyl group in one molecule is not particularly limited, but is more preferably 20 to 70 mol%. Further, a (meth) acrylate polymer having at least one carboxyl group in one molecule (a3)
And the amount of the (meth) acrylate monomer having one epoxy group in one molecule is based on the carboxyl group of the (meth) acrylate polymer (a3).
It is preferably 20 to 100 mol%, and 40 to 10 mol%.
More preferably, it is 0 mol%.

<Regarding the Fourth Method> The (meth) acrylate polymer (a4) having at least one epoxy group in one molecule is not particularly limited. Alternatively, it is only necessary that the (meth) acrylate monomer having at least one epoxy group in one molecule be an essential component.

The above (meth) acrylate monomers having at least one epoxy group in one molecule include:
The monomers exemplified in the second method are also exemplified. These other monomers may be used alone or in combination of two or more.

The (meth) acrylate polymer (a)
4) may be composed of only a (meth) acrylate monomer unit having at least one epoxy group in one molecule, but may contain another monomer unit.
As the other monomers, the monomers exemplified in the first method can be similarly mentioned. These other monomers may be used alone or in combination of two or more.

Examples of the (meth) acrylate monomer having one carboxyl group in one molecule include the monomers exemplified in the third method. These other monomers may be used alone or in combination of two or more.

The above (meth) acrylate polymer (a)
In 4), the ratio of the (meth) acrylate-based monomer unit having at least one epoxy group in one molecule is not particularly limited, but is more preferably 20 to 70 mol%. The amounts of the (meth) acrylate polymer (a3) having at least one epoxy group in one molecule and the (meth) acrylate monomer having one carboxyl group in one molecule are as follows. 20 to 1 with respect to the epoxy group of the (meth) acrylate polymer (a4)
00 mol%, preferably 40 to 100 mol%
Is more preferable.

The above (meth) acrylate polymer (A)
Can be adjusted to various molecular weights and glass transition temperatures according to applications, and has a number average molecular weight of 1,000 to 200,000.
It can be manufactured over a wide range. A more preferred number average molecular weight is from 2,000 to 50,000.

The (meth) acrylate polymer of the present invention is a polymer obtained by polymerizing an acrylic monomer component as described above. The polymer can be modified by partially using a monomer other than the acrylate-based monomer as long as the curability and performance of the polymerizable resin composition of the present invention are not affected. However, in order to express the physical properties of the original acrylate-based polymer, when the raw material monomer component for obtaining the (meth) acrylate-based polymer of the present invention is 100% by weight, The proportion of the acrylic monomer occupying is preferably 60 to 100% by weight. More preferably, 70-100% by weight, even more preferably 8%
It is 0-100% by weight, more preferably 90-100% by weight.

The monomer other than the acrylate monomer is not particularly limited as long as it has copolymerizability with the acrylic monomer. For example, styrene, divinylbenzene, vinyl ether, maleic acid, and the like.

The polymerizable monomer (B) which can be used in the present invention
Is a polymerizable monomer (B) represented by the following general formula (1) and / or general formula (2). General formula (1):

[0062]

Embedded image

Formula (2):

[0064]

Embedded image

(However, in the above general formulas (1) and (2), R
^{1 to} R ⁴ are H or an alkyl group having 1 to 12 carbon atoms and / or an alicyclic alkyl group, which may be the same or different. When R ^{1 to} R ⁴ are hydrogen, a monovalent metal salt;
It may be in the form of any of divalent metal salts, phosphates, ammonium salts and organic amine base salts. Further, more preferably, the structure of the above general formulas (1) and (2) is not a salt structure, that is, in the general formulas (1) and (2), R ^{1 to} R ⁴ are hydrogen or carbon number. This is the case where 1 to 12 alkyl groups and / or alicyclic alkyl groups are the same or different.

In the present invention, the efficiency as a polymerization solvent, the workability, and the physical properties of the polymerizable resin composition when included in the polymerizable resin composition (viscosity and polymerizability: the possibility of side reaction with vinyl ethers In view of the above, it is a more preferred embodiment that the structure of the general formulas (1) and (2) is not a salt structure as described above.

More specifically, as the polymerizable monomer (B) in the present invention, dimethyl maleate, diethyl maleate, dinormal butyl maleate, diisobutyl maleate, dioctyl maleate, dilauryl maleate, fumarate maleate Examples thereof include dimethyl acid, diethyl fumarate, dinormal butyl fumarate, diisobutyl fumarate, dioctyl fumarate, and dilauryl fumarate. These may be used alone or in combination of two or more.

The vinyl ethers (C) in the present invention include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, triethylene glycol divinyl ether, cyclohexane dimethanol divinyl ether, hydroxybutyl vinyl ether and the like. These may be used alone or in combination of two or more. It is not particularly limited to these. Further, the polymerizable resin composition of the present invention includes a polymerizable monomer (B) represented by the above general formula (1) and / or the general formula (2) other than the vinyl-ethers (C). A polymerizable monomer may be contained. For example, (meth) acrylates such as butyl acrylate and methyl methacrylate;
Allyl esters such as diallyl phthalate; Allyl ethers such as trimethylol allyl ether; Vinyl esters such as vinyl acetate; Polymerizable monomers (B) and vinyl ethers for aromatic monomers such as styrene It can be used together with (C) to such an extent that the effects of the polymerizable resin of the present invention such as curability and physical properties are not impaired.

For example, the amount of the polymerizable monomer other than the polymerizable monomers (B) and vinyl ethers (C) represented by the general formulas (1) and / or (2) is particularly Although not limited, the range is preferably 20 to 0% by weight, more preferably 10 to 0% by weight, based on 100% by weight of the polymerizable resin composition of the present invention. More preferably, it is 5-0% by weight. If necessary, a crosslinkable monomer that can be classified as a crosslinkable monomer can be used in combination. For example, if it is an acrylate type, it is ethylene glycol diacrylate, and if it is an aromatic type, it is divinylbenzene. What is necessary is just to adjust the addition amount according to desired physical properties.

The method for producing the polymerizable resin composition of the present invention includes (1) ketones such as methyl ethyl ketone and methyl isobutyl ketone, acetates such as ethyl acetate and butyl acetate, and aromatic compounds such as toluene and xylene. And the like. Polymerize the (meth) acrylate polymer (A) in a normal solvent such as
And (2) diluting the polymerizable monomer (B) with a reaction medium (polymerization solvent)
A method in which a (meth) acrylate polymer (A) is polymerized and then diluted with a vinyl ether (C). In particular, the method (2) is preferable because the polymerizable resin composition can be produced in one step. Specifically, the (meth) acrylate-based polymer (A) was obtained by radical polymerization in the polymerizable monomer (B) represented by the general formula (1) and / or (2). After that, it is preferable to adopt a method of blending the polymerizable monomer (D) for production.

The reaction medium (polymerization solvent) of the present invention includes
Although the use of the polymerization solvent represented by the general formula (1) or (2) is preferable, the polymerizable resin composition of the present invention is preferably used in combination with monomers such as vinyl ethers (C) to be blended later. And a polymerizable double bond which may be introduced into the side chain and / or the terminal of the (meth) acrylate polymer, exhibits good polymerizability, and has the general formula (1) described above. ) And the general formula (2) have the following characteristics. <Even if the acrylate monomer is subjected to radical polymerization, it does not substantially participate in radical polymerization. Has substantially no radical polymerizability. > As long as the monomer has the same properties as the reaction medium (polymerization solvent) of the present invention, in combination with the polymerizable monomer (B) represented by the above general formula (1) or (2) You can also.

For example, dibutyl malate which is a class of the general formula (1) or (2) presented in the reaction medium (polymerization solvent) of the present invention has a specific functional group (in this case, a malate group or a fumarate group). Groups and double bonds derived from vinyl ether monomers). Therefore, if a monomer having such properties is used as the reaction medium (polymerization solvent) of the present invention, the general formula (1) or the general formula (2)
Can be used in combination with the polymerizable monomer (B). The ratio of the monomers used in combination is not particularly limited as long as the production method of the present invention and the desired physical properties of the finally obtained polymerizable resin composition are not hindered.

In the present invention, in order to preferably obtain the finally obtained polymerizable resin composition of the present invention, or in order for the obtained polymerizable resin composition to have preferable polymerizability, the above general formula It is preferable to obtain a (meth) acrylate polymer (A) by radical polymerization of a predetermined acrylate monomer using the formula (1) or the general formula (2) as a reaction medium (polymerization solvent).

More specifically, when the reaction medium (polymerization solvent) of the present invention is 100% by weight, the reaction medium (B) of the monomer (B) represented by the general formula (1) or (2) The content in the polymerization solvent is preferably 20 to 100% by weight.
0-100% by weight is more preferred. More preferably, 5
0-100% by weight. More preferably, 60-10
0% by weight. More preferably, it is 80 to 100% by weight. More preferably, it is 90-100% by weight.
As described above, a reaction medium (polymerization solvent) substantially containing the monomer represented by the general formula (1) or (2) as a main component
It is preferable to employ

In the polymerization solvent of the present invention, as described above, it may be necessary to remove the used organic solvent later in a devolatilization step or the like. It is also possible to use a solvent or the like in combination. For example, when the weight average molecular weight of the acrylate-based polymer (A) is increased, the type of the acrylate-based monomer to be selected, or the single unit represented by the general formula (1) or (2) is selected. In the case where the polymerization efficiency is reduced depending on the type of the monomer (B), an organic solvent may be used in combination if desired. The organic solvent used at that time is not limited. The amount of use can also be appropriately set as desired.

Further, using the polymerizable monomer (B) of the present invention as a reaction medium (solvent for polymerization), a (meth) acrylate polymer (A) is polymerized, and then the polymerizable monomer (D) is used. As the polymerizable monomer (D) in the production method for dilution, a vinyl ether (C) is most preferable, but a polymerizable monomer having good reactivity with other malate groups and / or fumarate groups is used. Can also be used. Other polymerizable monomers (D) include styrene derivatives such as styrene and α-methylstyrene. More specifically, in the present invention, the monomer component for producing the (meth) acrylate polymer (A) is radically polymerized using the polymerizable monomer (B) as a reaction medium (polymerization solvent). That is. The ratio of the amount of the polymerization solvent and the amount of the monomer component for polymerization that can be employed during the polymerization is not particularly limited. The use ratio may be selected so that the polymerization efficiency or the content of each component, which is preferable for the finally obtained polymerizable resin composition, is obtained.

The (meth) acrylate polymer (A)
In the case of the (meth) acrylate polymer (A1) having a malate group and / or a fumarate group at a terminal and / or a side chain, the (meth) acrylate is produced by the same production method as in the above (1) and (2). After synthesizing the base polymer (A), the obtained polymer is reacted with maleic anhydride, or an alkyl half ester of maleic acid and / or an alkyl half ester of fumaric acid is obtained. Or a combination of maleic anhydride and a compound having one alcoholic hydroxyl group in one molecule is reacted with the obtained polymer (more specifically, the obtained ( A compound having one alcoholic hydroxyl group in one molecule in the presence of maleic anhydride with respect to the (meth) acrylate-based polymer (A), It reacted against,) having a malate group, and / or fumarate groups in terminal and / or side chain by (meth) acrylate polymer (A1)
And then diluting with the polymerizable monomer (D) to obtain the desired polymerizable resin composition.

The ratio of the total amount of the maleate group and / or the fumarate group of the (meth) acrylate polymer (A) and / or the polymerizable monomer (B) of the present invention to the unsaturated group of the vinyl ether (C) Is not particularly limited, but the unsaturated group of vinyl ethers (C) is based on the total amount of the maleate group and / or fumarate group of the (meth) acrylate polymer (A) and / or the polymerizable monomer (B). Preferably, the molar ratio is in the range of 0.7 to 1.4,
The range of 0.9 to 1.1 is more preferable. If the amount is too small or too large, when the polymerizable composition is cured, sufficient curability is not obtained, and desired physical properties are hardly obtained.

The (meth) acrylate polymer (A), polymerizable monomer (B) and vinyl ethers (C) of the present invention
The proportion of the (meth) acrylate-based polymer (A) is 5 to 80% by weight in 100% by weight of the resin composition, and the polymerizable monomer (B) is not particularly limited.
Is 5 to 50% by weight, and vinyl ethers (C) are 5 to 50% by weight.
% By weight, (meth) acrylate polymer (A) is 10 to 60% by weight, and polymerizable monomer (B)
Is 10 to 45% by weight, and vinyl ethers (C) are 10 to 45% by weight.
More preferably, it is 45% by weight.

A cured product can be obtained by curing the polymerizable resin composition. The curing conditions are not particularly limited, but the polymerizable resin composition of the present invention has excellent curability in the presence of oxygen, and can be dried at room temperature in air.

The polymerizable resin composition of the present invention may contain various additives as necessary. As additional components,
Azo-based compounds such as azobisisobutyronitrile and azobisisovaleronitrile; organic peroxides such as benzoyl peroxide, lauroyl peroxide, acetyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide and di-tert-butyl peroxide. Radical polymerization initiators such as compound-based radical polymerization initiators, acetophenone-based compounds, benzoin-based compounds, benzophenone-based compounds, thioxanthone-based compounds, imidazole-based compounds, and acylphosphine oxide-based compounds. These polymerization initiators can be used in combination. If desired, a radical polymerization initiator and a photopolymerization initiator may be used in combination. If necessary, the composition can be cured by heating or light irradiation.

100% by weight of the polymerizable resin composition of the present invention
The preferable addition amount of the polymerization initiator is 0.1 to 15% by weight. More preferably, 0.3 to 10
% By weight.

The polymerizable resin composition of the present invention can be preferably used as a curable resin composition which can be cured in various cured forms by blending these polymerization initiators. Therefore, a curable resin composition using the polymerizable composition of the present invention is one of the preferable embodiments of the present invention. For example, the polymerizable resin composition of the present invention can be used as a photosensitive resin composition if a photopolymerization initiator is added. Further, in the embodiment of the present invention, a cured product using the polymerizable resin composition of the present invention is one of preferred embodiments.

Further, other additives include, for example, polymerization inhibitors such as hydroquinone and paramethoxyphenol, and the addition amount is preferably 0.01 to 0.1% by weight.

Further, to the polymerizable resin composition of the present invention, a plasticizer such as dibutyl phthalate and a diluent such as an epoxy group-containing compound and an oxetane ring-containing compound can be added. Also, by blending a filler such as talc, calcium carbonate, silica, mica, etc., it can be used for various molding materials.

The polymerizable resin composition of the present invention can be mixed with various paint compositions and coating compositions by blending a pigment such as titanium oxide, carbon black, phthalocyanine blue or a thixotropic agent as required. It can also be used as a composition. Of course, it is also effective as a coating composition for a top coat that does not use a pigment or the like. In addition, as other additives, foaming agent, antioxidant, ultraviolet absorber,
Lubricants and the like. Of course, it is not limited to these lists.

The polymerizable resin composition of the present invention may be used in the same manner as generally used polymerizable resin compositions, such as various FRP molded products, casting, buttons, decorative plate resins, insulating varnish resins, and the like. Wood, paper, particle board, metal, plastic, glass, concrete, asphalt, ceramic, etc. coating materials for various base materials, bolt fixing materials, floor coating materials, paint resins, putties, sealing agents, adhesives, printing ink binders , Resin for stereolithography, resin for solder resist, resin for photoresist, resin for printing plate,
It can be used for various photosensitive resins, various molding materials, and the like.

Further, various molded articles and molded articles obtained by curing the polymerizable composition of the present invention are also one of the preferred embodiments of the present invention.

[0089]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

The number average molecular weight of the present invention was determined by using the following conditions: Measurement conditions for number average molecular weight: GPC-8020 series (manufactured by Tosoh Corporation). Column: two TSK-gel GMHXL, G2000H.
XL2 using tetrahydrofuran as solvent, measuring temperature 40 ° C
The number molecular weights described above are molecular weights in terms of standard polystyrene.

In the following, "parts" and "%" are "parts by weight" and "% by weight", respectively, unless otherwise specified.

Example 1 A four-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen blowing tube was charged with 100 parts of methyl isobutyl ketone, and the temperature was raised to the reflux temperature while blowing nitrogen. Next, 2-
A monomer liquid obtained by mixing 15 parts of hydroxyethyl acrylate, 85 parts of ethyl acrylate, and 4 parts of azobisisobutyronitrile was uniformly dropped over 6 hours.
It was kept at the same temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 3,300.

Next, 12 parts of maleic anhydride was added, and 11 parts of maleic anhydride were added.
It was kept at 5 ° C. for 3 hours. Thereafter, the mixture was devolatilized under reduced pressure using an evaporator, and further washed with petroleum ether. This operation was repeated three times to obtain a viscous liquid. ^{By 1} H-NMR, it was confirmed that a polymerization bond derived from maleic acid was introduced into a side chain of the polymer. 20 parts of dimethyl malate and 25 parts of butyl vinyl ether 25 were added to 100 parts of the obtained viscous liquid.
Was added to obtain a polymerizable resin composition (1).

Example 2 100 parts of methyl isobutyl ketone was charged into a four-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen blowing tube, and the temperature was raised to 90 ° C. while blowing nitrogen. Next, a monomer liquid prepared by previously mixing 15 parts of 2-hydroxyethyl acrylate, 35 parts of butyl acrylate, 50 parts of methyl methacrylate, and 1.5 parts of azobisisobutyronitrile is uniformly dropped over 3 hours. After completion of the dropwise addition, the mixture was kept at the same temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 14,
500.

Next, 12 parts of maleic anhydride was added, and
The mixture was kept at 5 ° C. for 3 hours to obtain a reaction product containing a polymer having an acid value of 34. Thereafter, the mixture was devolatilized under reduced pressure using an evaporator, and further washed with petroleum ether. This operation was repeated three times to obtain a viscous liquid. To 100 parts of the obtained viscous liquid, 30 parts of dibutyl fumarate and 25 parts of triethylene glycol divinyl ether were added to obtain a polymerizable resin composition (2).

Example 3 150 parts of dimethyl malate was charged into a four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen blowing tube.
The temperature was raised to 0 ° C. Next, a monomer solution prepared by mixing 25 parts of previously prepared 2-hydroxyethyl acrylate, 175 parts of cyclohexyl methacrylate, and 7 parts of azobisisobutyronitrile was uniformly added dropwise over 3 hours. It was kept at the temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 6,400.

Next, 20 parts of maleic anhydride was added to the system. Thereafter, the reaction was performed at 90 ° C. for 2 hours. To this, add 0.4 parts of hydroquinone and 1 part of triethylamine,
The system was further heated to 115 ° C. in a mixed gas (nitrogen / air = 2/1) atmosphere. Next, 30 parts of glycidyl methacrylate was gradually added while controlling the heat generation, and further maintained at the same temperature for 7 hours. To this, 60 parts of cyclohexanedimethanol divinyl ether and 63 parts of triethylene glycol divinyl ether were added to obtain a polymerizable resin composition (3).

Example 4 150 parts of dimethyl malate was charged into a four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen blowing tube.
The temperature was raised to 0 ° C. Next, a monomer solution prepared by mixing 25 parts of previously prepared 2-hydroxyethyl acrylate, 175 parts of cyclohexyl methacrylate, and 7 parts of azobisisobutyronitrile was uniformly added dropwise over 3 hours. It was kept at the temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 6,400.

Next, 20 parts of maleic anhydride was added to the system. Thereafter, the reaction was performed at 90 ° C. for 2 hours. To this, add 0.4 parts of hydroquinone and 1 part of triethylamine,
Further, the temperature inside the system was raised to 115 ° C. Next, 17 parts of allyl glycidyl ether was gradually added while controlling the heat generation, and the temperature was further maintained at the same temperature for 7 hours. To this, 60 parts of cyclohexane dimethanol divinyl ether and 63 parts of triethylene glycol divinyl ether were added to obtain a polymerizable resin composition (4).

Embodiment 5 FIG. 100 parts of methyl isobutyl ketone was charged into a four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen blowing tube, and the temperature was raised to the reflux temperature while blowing nitrogen. Next, 30 parts of glycidyl methacrylate prepared in advance and 70 parts of ethyl acrylate were prepared.
, And a monomer liquid obtained by mixing 3 parts of azobisisobutyronitrile was uniformly dropped over 3 hours. After the completion of the dropping, the mixture was kept at the same temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 6,500.

Next, 27 parts of fumaric acid monomethyl ester and 1 part of triethylamine were added, and the temperature was raised to 115 ° C. and maintained at the same temperature for 7 hours. Thereafter, the mixture was devolatilized under reduced pressure using an evaporator, and further washed with petroleum ether. This operation was repeated three times to obtain a viscous liquid. 30 parts of dimethyl malate and 37 parts of butyl vinyl ether were added to 100 parts of the obtained viscous liquid to obtain a polymerizable resin composition (5).

Embodiment 6 FIG. ] A four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen blowing tube was charged with 150 parts of dibutyl fumarate, and charged with nitrogen while blowing 1 part.
The temperature was raised to 20 ° C. Next, 40 parts of glycidyl methacrylate previously prepared and 160 parts of methyl methacrylate were prepared.
And 9 parts of azobisisobutyronitrile were uniformly added dropwise over 4 hours, and after completion of the addition, the mixture was kept at the same temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 5,100. Next, the temperature in the system was raised to 115 ° C., and 35 parts of maleic acid monomethyl ester and 1 part of triethylamine were added to the system. Thereafter, the temperature was maintained at the same temperature for 7 hours. Thereafter, 95 parts of triethylene glycol divinyl ether was added to obtain a polymerizable composition (6).

Example 7 A four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen gas inlet tube was charged with 150 parts of dibutyl malate.
The temperature was raised to 0 ° C. Next, a previously prepared monomer liquid obtained by mixing 150 parts of methyl methacrylate and 7 parts of azobisisobutyronitrile was uniformly added dropwise over 5 hours. After completion of the addition, the mixture was kept at the same temperature for 2 hours, and cooled. did. The number average molecular weight of the obtained polymer was 5,400. To this, 65 parts of triethylene glycol divinyl ether was added to obtain a polymerizable resin composition (7).

Example 8 A four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and a nitrogen blowing tube was charged with 150 parts of dibutyl fumarate, and charged with nitrogen while blowing nitrogen.
The temperature was raised to 20 ° C. Next, a previously prepared monomer liquid obtained by mixing 20 parts of methacrylic acid, 140 parts of methyl methacrylate, 40 parts of butyl acrylate, and 9 parts of azobisisobutyronitrile was uniformly dropped over 4 hours, and the dropping was completed. Thereafter, the mixture was kept at the same temperature for 2 hours and cooled. The number average molecular weight of the obtained polymer was 4,800.

Next, 0.4 part of hydroquinone and 1 part of triethylamine were added, and a mixed gas (nitrogen / air =
2/1) The temperature was raised to 115 ° C. in an atmosphere. Further, 33 parts of glycidyl methacrylate was added to the system. Thereafter, the temperature was maintained at the same temperature for 7 hours. Thereafter, 95 parts of triethylene glycol divinyl ether was added, and the polymerizable composition (8) was added.
I got

Example 9 A four-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen blowing tube was charged with 100 parts of dibutyl malate and 100 parts of methyl ethyl ketone, and heated to a reflux temperature while blowing nitrogen. . Next, a monomer solution prepared by mixing 150 parts of methyl methacrylate previously prepared and 7 parts of azobisisobutyronitrile was uniformly dropped over 5 hours, and after completion of the dropping, kept at the same temperature for 2 hours and cooled. did. The number average molecular weight of the obtained polymer was 7,500. After completion of the reaction, methyl ethyl ketone was degassed under reduced pressure so that dibutyl malate would not evaporate.
Triethylene glycol divinyl ether 6
6 parts were added to obtain a polymerizable resin composition (9).

Note that, in Example 2-9 except for the above-described Example 7, ¹ H—N was obtained under the same conditions as in Example 1.
By using MR, it was found that the polymer was a polymer having a double bond introduced therein (specifically, a polymer having a maleate group, a fumarate group or an acryloyl double bond introduced therein).

Comparative Example 1 Bisphenol A type epoxy resin (epoxy equivalent: 185) 37 was placed in a four-necked flask equipped with a stirrer, a dropping funnel, a thermometer, and an air blowing tube.
0 parts, 176.3 parts of methacrylic acid, 2.3 parts of triethylamine, 0.2 parts of hydroquinone, and reacted at 115 ° C. for 8 hours while blowing air thereinto. Thereafter, 234.1 parts of butyl vinyl ether was added, and an acid value of 6.5 was added. A vinyl ester resin (A) was obtained. The number average molecular weight of the obtained polymer was 840.

Comparative Example 2 100 parts of methyl isobutyl ketone was charged into a four-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen blowing tube, and the temperature was raised to 90 ° C. while blowing nitrogen. Next, a monomer solution prepared by previously mixing 15 parts of methacrylic acid, 85 parts of ethyl acrylate, and 1.5 parts of azobisisobutyronitrile was uniformly dropped over 3 hours. For 2 hours and cooled. The number average molecular weight of the obtained polymer was 14,
500. Next, 20 parts of glycidyl methacrylate was added, and the mixture was kept at 115 ° C. for 6 hours while blowing air. Thereafter, the mixture was devolatilized under reduced pressure using an evaporator, and further washed with petroleum ether. This operation was repeated three times to obtain a viscous liquid. 30 parts of butyl vinyl ether was added to 70 parts of the obtained viscous liquid to obtain a polymerizable resin composition (B).

Comparative Example 3 A four-necked flask equipped with a stirrer, a dropping funnel, a thermometer and a nitrogen blowing tube was charged with 296 parts of phthalic anhydride, 294 parts of maleic anhydride, 152 parts of propylene glycol and 334 parts of diethylene glycol. After performing a dehydration condensation reaction at 210 ° C. for 6 hours while blowing nitrogen, the mixture was cooled to synthesize 986 parts of unsaturated polyester. 140 parts of the above unsaturated polyester was dissolved in 60 parts of a styrene monomer to obtain a polymerizable resin composition (C).

Comparative Example 4 As a urethane acrylate, UV-7550B manufactured by Nippon Synthetic Chemical Co., Ltd. was dissolved in 60 parts of triethylene glycol diacrylate using 140 parts of a diluent to obtain a polymerizable resin composition (D).

[Embodiment 10. ~ 18. Comparative Example 5. ~
8. ] The resin compositions (1) obtained in Examples 1 to 9
(9) The resin compositions (A) obtained in Comparative Examples 1 to 4.
(D) was evaluated for thermal radical curability and photo radical curability by the following method. Thermal radical curability Cobalt octenoate is added to 100 parts of each resin composition.
5 parts, 0.2 parts of dimethylaniline, and 1.0 part of a curing agent 328E (manufactured by Kayaku Akzo) were added, respectively, and applied on a glass substrate using an applicator so as to have a thickness of 200 μm. Cured. The time required for the coating film surface to dry to the touch at that time was defined as thermal radical curability, and the obtained cured product was subjected to an acetone rubbing test. The results are shown in Table 1. Photo-radical curability 100 parts of each resin composition is treated with a photo-curing agent Irgacure 6
51 (manufactured by Ciba-Geigy) was added, applied to a glass substrate using a bar coater so as to have a thickness of 30 μm, and cured by a belt conveyor type UV curing device. The energy required for touch drying of the coating surface at that time (10
0 mj / time) was taken as the heat-radical curability, and an acetone rubbing test was performed on the obtained cured product. The results are shown in Table 1.

[0113]

[Table 1]

Criteria for acetone rubbing test: A cotton cloth impregnated with acetone was used for one reciprocation at a time, and the coating was rubbed 50 times, and the state of the coating at that time was determined as follows. In addition, about the coating film which is not dried in 8 hours, that is, the surface hardening property does not come out, the subsequent acetone rubbing test was not performed and the evaluation was described as <-> in the table. And it evaluated as follows. ◎ Scratches, not dissolved ○ Some scratches, but not dissolved × Dissolved

[0115]

The (meth) acrylate polymer (A) contained in the radically polymerizable resin composition of the present invention can be adjusted to various molecular weights depending on the application. Further, the above (meth) acrylate polymer (A), a polymerizable monomer (B) represented by the following general formulas (1) and / or (2) having low skin irritation as a diluent and vinyl ethers: Can be easily produced. Moreover, the radically polymerizable resin composition of the present invention has excellent curability in the presence of oxygen. General formula (1)

[0116]

Embedded image

General formula (2)

[0118]

Embedded image

(In the above general formulas (1) and (2), R ¹ to
R ⁴ is H or an alkyl group having 1 to 12 carbon atoms and / or an alicyclic alkyl group, which may be the same or different. When R ^{1 to} R ⁴ are hydrogen, a monovalent metal salt;
It may be in the form of any of divalent metal salts, phosphates, ammonium salts and organic amine base salts. More preferably, the structure of the above general formulas (1) and (2) is not a salt structure, that is, the general formulas (1) and (2)
Wherein R ^{1 to} R ⁴ are hydrogen or an alkyl group having 1 to 12 carbon atoms and / or an alicyclic alkyl group, which may be the same or different.

In the present invention, the efficiency as a polymerization solvent, the workability, and the physical properties of the polymerizable resin composition when included in the polymerizable resin composition (viscosity and polymerizability: a side reaction with vinyl ethers may occur) From the viewpoint of, for example, the case where the structures of the general formulas (1) and (2) are not salt structures as described above, is a more preferred embodiment.

Continued on the front page F-term (reference) 4J011 PA69 PB30 QA03 QA08 QA19 QA20 QA35 UA01 UA08 4J026 AA45 AA48 AA76 BA15 BA17 BA27 BA30 BA33 BA35 BA36 DB02 FA04 4J027 AA01 AA02 BA03 BA07 BA08 BA09 BA08 CC08

Claims (4)

[Claims] 1. A (meth) acrylate-based polymer (A),
A polymerizable resin composition comprising a polymerizable monomer (B) represented by the following general formula (1) and / or general formula (2) and a vinyl ether (C). General formula (1): General formula (2): (However, in the general formulas (1) and (2), R ^{1 to} R ⁴ are hydrogen or an alkyl group having 1 to 12 carbon atoms and / or an alicyclic alkyl group, and may be the same or different. When R ^{1 to} R ⁴ are hydrogen, they may be in the form of any of monovalent metal salts, divalent metal salts, phosphates, ammonium salts and organic amine groups.) 2. The polymerizable resin composition according to claim 1, wherein the (meth) acrylate polymer (A) has a polymerizable double bond at a terminal and / or a side chain. 3. The polymerizable double bond according to claim 2, wherein the polymerizable double bond is at least one polymerizable double bond selected from the group consisting of a malate group, a fumarate group, and a (meth) acryloyl group. The polymerizable resin composition according to the above. 4. A polymer obtained by subjecting a (meth) acrylate-based polymer (A) to radical polymerization in a polymerizable monomer (B) represented by the following general formula (1) and / or (2). A method for producing a polymerizable resin composition, comprising blending a polymerizable monomer (D). General formula (1): General formula (2): (In the above general formulas (1) and (2), R ^{1 to} R ⁴ are hydrogen or an alkyl group having 1 to 12 carbon atoms and / or an alicyclic alkyl group, which may be the same or different. When R ^{1 to} R ⁴ are hydrogen, they may be in the form of any of a monovalent metal salt, a divalent metal salt, a phosphate, an ammonium salt and an organic amine group salt.)