WO2017146238A1

WO2017146238A1 - Latex composition and film molded body

Info

Publication number: WO2017146238A1
Application number: PCT/JP2017/007225
Authority: WO
Inventors: 直広伊賀利; 実紗山本; 昌北川; 慎二加藤
Original assignee: 日本ゼオン株式会社
Priority date: 2016-02-25
Filing date: 2017-02-24
Publication date: 2017-08-31
Also published as: MY194391A

Abstract

Provided is a latex composition which contains a latex of a carboxyl group-containing conjugated diene-based rubber (A) and a metal compound containing a trivalent or higher metal, wherein the content of the metal compound is 0.1-1.5 parts by weight relative to 100 parts by weight of the carboxyl group-containing conjugated diene-based rubber (A).

Description

Latex composition and film molded body

The present invention relates to a latex composition that can suppress the occurrence of delayed allergy (Type IV) in addition to immediate allergy (Type I), and has high tensile strength, large elongation, and a flexible texture. The present invention relates to a latex composition capable of providing a film molded body such as a dip molded body, a method for producing such a latex composition, and a dip molded body and a film molded body obtained using such a latex composition.

Conventionally, a dip-molded product that is used in contact with a human body such as a nipple, a balloon, a glove, a balloon, and a sack is formed by dip-molding a latex composition containing a natural latex typified by a natural rubber latex. Yes. However, since natural rubber latex contains proteins that cause allergic symptoms in the human body, it contains proteins that cause immediate allergy (Type I) symptoms in the human body, so it is in direct contact with living mucous membranes or organs. There are cases where there is a problem as a dip-molded body. Therefore, studies have been made on using synthetic nitrile rubber latex.

For example, Patent Document 1 includes zinc oxide, sulfur and a vulcanization accelerator in an emulsion containing a carboxylated nitrile butadiene random terpolymer of acrylonitrile, carboxylic acid, and butadiene and having a total solid content of 15 to 25% by weight. Is disclosed. However, the technique of Patent Document 1 can prevent the occurrence of immediate type allergy (Type I). On the other hand, when a dip-molded body is formed, the human body is caused by sulfur and a vulcanization accelerator contained in the dip-molded body. When touched, allergic symptoms of delayed type allergy (Type IV) may occur.

On the other hand, for example, Patent Document 2 contains 25 to 30% by weight of acrylonitrile residues, 62 to 71% by weight of butadiene residues, and 4 to 8% by weight of unsaturated carboxylic acid residues, contains zinc oxide, and is crosslinked. Latex compositions that do not contain sulfur as an agent and sulfur compounds as vulcanization accelerators are disclosed. According to the technique of Patent Document 2, since sulfur and sulfur compounds that are vulcanization accelerators are not included, not only immediate type allergy (Type I) but also delayed type allergy (Type IV) can be suppressed. However, the obtained dip-molded article had low elongation and was also inferior in texture and touch.

Japanese Patent No. 5697578 Japanese Patent No. 5184720

The present invention can suppress the occurrence of delayed type allergy (Type IV) in addition to immediate type allergy (Type I), and has a high tensile strength, large elongation, a flexible texture, etc. An object of the present invention is to provide a latex composition capable of providing a film molded body, a method for producing such a latex composition, and a dip molded body and a film molded body obtained by using such a latex composition. To do.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a latex obtained by blending a predetermined amount of a metal compound containing a trivalent or higher metal into a latex of a carboxyl group-containing conjugated diene rubber (A). The present inventors have found that the above object can be achieved by a composition, and have completed the present invention.

That is, according to the present invention, a latex composition comprising a latex of a carboxyl group-containing conjugated diene rubber (A) and a metal compound (B) containing a trivalent or higher metal, the metal compound Is provided in a latex composition of 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the carboxyl group-containing conjugated diene rubber (A).
Preferably, the metal compound (B) is an aluminum compound.

The latex composition of the present invention further contains at least one alcoholic hydroxyl group-containing compound (C) selected from saccharide (c1), sugar alcohol (c2), hydroxy acid (c3) and hydroxy acid salt (c4). It is preferable to do.
Preferably, the content of the metal compound (B) and the content of the alcoholic hydroxyl group-containing compound (C) are in a weight ratio of “metal compound (B): alcoholic hydroxyl group-containing compound (C)”. 1: 0.1 to 1:50.
Preferably, the alcoholic hydroxyl group-containing compound (C) is at least one selected from sugar alcohol (c2) and hydroxy acid salt (c4).

Preferably, the carboxyl group-containing conjugated diene rubber (A) comprises 56 to 78% by weight of a conjugated diene monomer unit, 20 to 40% by weight of an ethylenically unsaturated nitrile monomer unit, and an ethylenically unsaturated acid monomer. A carboxyl group-containing nitrile rubber (a1) containing 2 to 6.5% by weight of a monomer unit.
Preferably, the carboxyl group-containing conjugated diene rubber (A) is a conjugated diene monomer unit, an ethylenically unsaturated carboxylic acid monomer unit, an amide group-containing monomer unit, and an epoxy group-containing monomer. And at least one monomer unit selected from the units.
Preferably, the monomer constituting at least one monomer unit selected from the amide group-containing monomer unit and the epoxy group-containing monomer unit is (meth) acrylamide.
Preferably, the monomer constituting at least one monomer unit selected from the amide group-containing monomer unit and the epoxy group-containing monomer unit is an epoxy group-containing (meth) acrylate.

Further, according to the present invention, there is provided a method for producing a latex composition comprising a latex of a carboxyl group-containing conjugated diene rubber (A) and a metal compound (B) containing a trivalent or higher metal. And
A monomer mixture containing at least a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer is subjected to emulsion polymerization at 0 to 25 ° C., whereby the latex of the carboxyl group-containing conjugated diene rubber (A) is obtained. A first step to obtain;
There is provided a method for producing a latex composition comprising a second step of blending the metal compound (B) with the latex of the carboxyl group-containing conjugated diene rubber (A).

Alternatively, according to the present invention, there is provided a method for producing a latex composition comprising a latex of a carboxyl group-containing conjugated diene rubber (A) and a metal compound (B) containing a trivalent or higher metal. And
The presence of 0.15 to 0.95 parts by weight of a chain transfer agent in a monomer mixture containing at least a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer with respect to 100 parts by weight of the monomer mixture A first step of obtaining a latex of the carboxyl group-containing conjugated diene rubber (A) by emulsion polymerization under;
There is provided a method for producing a latex composition comprising a second step of blending the metal compound (B) with the latex of the carboxyl group-containing conjugated diene rubber (A).

In the method for producing a latex composition, in the second step, in addition to the metal compound (B), a saccharide (c1), a sugar alcohol (to the latex of the carboxyl group-containing conjugated diene rubber (A) ( It is preferable to further blend at least one alcoholic hydroxyl group-containing compound (C) selected from c2), hydroxy acid (c3) and hydroxy acid salt (c4).

Moreover, according to this invention, the manufacturing method of a dip molded object provided with the process of dip-molding the latex composition of the said invention or the latex composition obtained by the manufacturing method of the said invention is provided.
Furthermore, according to this invention, the film molded object which consists of a latex composition of the said invention is provided.

According to the present invention, a dip-molded body that can suppress the occurrence of delayed allergy (Type IV) in addition to immediate allergy (Type I), and has high tensile strength, large elongation, and a soft texture. It is possible to provide a latex composition capable of providing a film molded body such as, a method for producing such a latex composition, and a dip molded body and a film molded body obtained using such a latex composition it can.

The latex composition of the present invention comprises a latex of carboxyl group-containing conjugated diene rubber (A) and a metal compound containing a trivalent or higher metal, and the content ratio of the metal compound is the carboxyl group-containing content. The latex composition is 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the conjugated diene rubber (A).

Latex of carboxyl group-containing conjugated diene rubber (A) The latex of carboxyl group-containing conjugated diene rubber (A) used in the present invention is a monomer comprising at least a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer. A latex of a copolymer obtained by copolymerizing a body mixture, and examples of the carboxyl group-containing conjugated diene rubber (A) include a carboxyl group-containing nitrile rubber (a1), a carboxyl group-containing styrene-butadiene rubber (a2), and At least one selected from carboxyl group-containing conjugated diene rubber (a3) is preferred.

The latex of the carboxyl group-containing nitrile rubber (a1) is a copolymer latex obtained by copolymerizing an ethylenically unsaturated nitrile monomer in addition to a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer. In addition to these, a latex of a copolymer obtained by copolymerizing other ethylenically unsaturated monomers copolymerizable with these used as necessary may be used.

Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and chloroprene. It is done. Among these, 1,3-butadiene and isoprene are preferable, and 1,3-butadiene is more preferable. These conjugated diene monomers can be used alone or in combination of two or more. The content ratio of the conjugated diene monomer unit formed by the conjugated diene monomer in the carboxyl group-containing nitrile rubber (a1) is preferably 56 to 78% by weight, more preferably 56 to 73% by weight, More preferably, it is 56 to 70% by weight. By making the content of the conjugated diene monomer unit within the above range, the obtained dip-molded product such as a dip-molded product should have excellent texture and large elongation while having sufficient tensile strength. Can do.

The ethylenically unsaturated carboxylic acid monomer is not particularly limited as long as it is an ethylenically unsaturated monomer containing a carboxyl group. For example, a single amount of ethylenically unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid Body; ethylenically unsaturated polyvalent carboxylic acid monomer such as itaconic acid, maleic acid, fumaric acid; ethylenically unsaturated polyvalent carboxylic acid anhydride such as maleic anhydride, citraconic anhydride; monobutyl fumarate, maleic acid And ethylenically unsaturated polyvalent carboxylic acid partial ester monomers such as monobutyl and mono-2-hydroxypropyl maleate. Among these, ethylenically unsaturated monocarboxylic acid is preferable, and methacrylic acid is particularly preferable. These ethylenically unsaturated carboxylic acid monomers can also be used as alkali metal salts or ammonium salts. Further, the ethylenically unsaturated carboxylic acid monomers can be used alone or in combination of two or more. The content ratio of the ethylenically unsaturated carboxylic acid monomer unit formed by the ethylenically unsaturated carboxylic acid monomer in the carboxyl group-containing nitrile rubber (a1) is preferably 2 to 6.5% by weight. More preferably, it is 2 to 6% by weight, more preferably 2 to 5% by weight, still more preferably 2 to 4.5% by weight, and particularly preferably 2.5 to 4.5% by weight. By setting the content of the ethylenically unsaturated carboxylic acid monomer unit in the above range, the film molded product such as a dip molded product obtained is excellent in texture and stretched while having sufficient tensile strength. Can be big.

The ethylenically unsaturated nitrile monomer is not particularly limited as long as it is an ethylenically unsaturated monomer containing a nitrile group. For example, acrylonitrile, methacrylonitrile, fumaronitrile, α-chloroacrylonitrile, α-cyanoethylacrylonitrile Etc. Of these, acrylonitrile and methacrylonitrile are preferable, and acrylonitrile is more preferable. These ethylenically unsaturated nitrile monomers can be used alone or in combination of two or more. The content ratio of the ethylenically unsaturated nitrile monomer unit formed by the ethylenically unsaturated nitrile monomer in the carboxyl group-containing nitrile rubber (a1) is preferably 20 to 40% by weight, more preferably It is 25 to 40% by weight, more preferably 30 to 40% by weight. By making the content of the ethylenically unsaturated nitrile monomer unit in the above range, the resulting film molded article such as a dip molded article is excellent in texture and has a larger elongation while having sufficient tensile strength. Can be.

Further, other ethylenically unsaturated monomers copolymerizable with the conjugated diene monomer, ethylenically unsaturated carboxylic acid monomer and ethylenically unsaturated nitrile monomer are not particularly limited, and can be obtained. From the viewpoint that the tensile strength of a film molded body such as a dip molded body can be further increased and a high stress retention can be provided, an amide group-containing monomer and an epoxy group-containing monomer Preferable examples include at least one monomer selected from the group consisting of:

The amide group-containing monomer is not particularly limited as long as it has at least one amide group in one molecule. For example, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl ( (Meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-butyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N- Dimethylaminopropyl (meth) acrylamide N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylol (meth) acrylamide, diacetone (meth) acrylamide, and (meth) acryloyl morpholine. Among these, (meth) acrylamide is preferable, N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide is more preferable, and N-methylol (meth) acrylamide is particularly preferable. These amide group-containing monomers can be used alone or in combination of two or more.

The content ratio of the amide group-containing monomer unit in the carboxyl group-containing nitrile rubber (a1) is preferably 0.1 to 5.0% by weight, more preferably 0.25 to 4.5% by weight, More preferably, it is 0.5 to 4.0% by weight. By setting the content of the amide group-containing monomer unit in the above range, the obtained molded film such as a dip molded body can be further improved in tensile strength and provided with a high stress retention. be able to

The epoxy group-containing monomer is not particularly limited as long as it is a monomer having at least one epoxy group in one molecule. For example, glycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, vinyl glycidyl ether, allyl glycidyl ether, 2-methylallyl glycidyl ether, 3,4-epoxy-1-butene, 3,4-epoxy-1-methyl-1-butene, 3,4-epoxy-1-pentene, 3,4-epoxy-3-methyl-1-pentene, 5,6-epoxy-1-hexene, 1,2-vinylcyclohexene monoepoxide, styrene-p-glycidyl ether, etc. Is mentioned. Among these, an epoxy group-containing (meth) acrylate is preferable, and glycidyl (meth) acrylate is particularly preferable. These epoxy group-containing monomers can be used alone or in combination of two or more.

The content ratio of the epoxy group-containing monomer unit in the carboxyl group-containing nitrile rubber (a1) is preferably 0.1 to 4.0% by weight, more preferably 0.25 to 3.5% by weight, More preferably, it is 0.5 to 3.0% by weight. By setting the content of the epoxy group-containing monomer unit in the above range, the obtained molded film such as a dip molded body can be further improved in tensile strength and provided with a high stress retention. be able to.

The carboxyl group-containing nitrile rubber (a1) is a copolymerizable other ethylenically unsaturated monomer other than at least one monomer selected from amide group-containing monomers and epoxy group-containing monomers. Such other copolymerizable ethylenically unsaturated monomers include, for example, vinyl aromatic monomers such as styrene, alkylstyrene and vinylnaphthalene; fluoro Fluoroalkyl vinyl ethers such as ethyl vinyl ether; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, trifluoroethyl (meth) acrylate, (meth ) Tetrafluoropropyl acrylate, dibutyl maleate, dibutyl fumarate, diethyl maleate , Methoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, cyanomethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, (meth) acrylic acid-1 -Cyanopropyl, 2-ethyl-6-cyanohexyl (meth) acrylate, 3-cyanopropyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, dimethylaminoethyl ( Ethylenically unsaturated carboxylic acid ester monomers such as (meth) acrylate; divinylbenzene, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol (meth) a Crosslinking monomers such relations; and the like. These ethylenically unsaturated monomers can be used alone or in combination of two or more.

In the carboxyl group-containing nitrile rubber (a1), the content of other monomer units formed by other ethylenically unsaturated monomers is preferably 10% by weight or less, more preferably 5% by weight. Hereinafter, it is more preferably 3% by weight or less.

The latex of the carboxyl group-containing nitrile rubber (a1) used in the present invention is obtained by copolymerizing a monomer mixture containing the above-mentioned monomers, and a method of copolymerization by emulsion polymerization is preferred. The emulsion polymerization method will be described later.

The latex of carboxyl group-containing styrene-butadiene rubber (a2) used in the present invention is copolymerized with styrene in addition to 1,3-butadiene and an ethylenically unsaturated carboxylic acid monomer as a conjugated diene monomer. In addition to these, a latex of a copolymer obtained by copolymerizing another ethylenically unsaturated monomer copolymerizable with these, which is used as necessary. There may be.

The content ratio of butadiene units formed from 1,3-butadiene in the carboxyl group-containing styrene-butadiene rubber (a2) is preferably 56 to 78% by weight, more preferably 56 to 73% by weight, still more preferably. Is 56 to 70% by weight. By setting the content of the butadiene unit within the above range, it is possible to make the film molded body such as a dip molded body obtained excellent in the texture and have a larger elongation while making the tensile strength sufficient.

The ethylenically unsaturated carboxylic acid monomer is not particularly limited as long as it is an ethylenically unsaturated monomer containing a carboxyl group. For example, the same as the latex of the carboxyl group-containing nitrile rubber (a1) described above Can be used. The content of the ethylenically unsaturated carboxylic acid monomer unit formed by the ethylenically unsaturated carboxylic acid monomer in the carboxyl group-containing styrene-butadiene rubber (a2) is preferably 2 to 6.5% by weight. More preferably, it is 2 to 6% by weight, more preferably 2 to 5% by weight, still more preferably 2 to 4.5% by weight, and particularly preferably 2.5 to 4.5% by weight. By setting the content of the ethylenically unsaturated carboxylic acid monomer unit in the above range, the film molded product such as a dip molded product obtained is excellent in texture and stretched while having sufficient tensile strength. Can be big.

In the carboxyl group-containing styrene-butadiene rubber (a2), the content of styrene units formed by styrene is preferably 20 to 40% by weight, more preferably 25 to 40% by weight, and still more preferably 30 to 40%. % By weight. By setting the content of the styrene unit within the above range, it is possible to make the film molded body such as a dip molded body obtained excellent in the texture and have a larger elongation while making the tensile strength sufficient.

Further, 1,3-butadiene as the conjugated diene monomer, ethylenically unsaturated carboxylic acid monomer and other ethylenically unsaturated monomers copolymerizable with styrene are not particularly limited, and can be obtained. From the viewpoint that the tensile strength of a film molded body such as a dip molded body can be further increased and a high stress retention can be provided, an amide group-containing monomer and an epoxy group-containing monomer Preferable examples include at least one monomer selected from the group consisting of:

The amide group-containing monomer is not particularly limited as long as it is a monomer having at least one amide group in one molecule. For example, the same amide group-containing nitrile rubber (a1) latex as described above is used. Can be used. The content ratio of the amide group-containing monomer unit in the carboxyl group-containing styrene-butadiene rubber (a2) is preferably 0.1 to 5.0% by weight, more preferably 0.25 to 4.5% by weight. %, More preferably 0.5 to 4.0% by weight. By setting the content of the amide group-containing monomer unit in the above range, the obtained molded film such as a dip molded body can be further improved in tensile strength and provided with a high stress retention. be able to.

The epoxy group-containing monomer is not particularly limited as long as it is a monomer having at least one epoxy group in one molecule. For example, the epoxy group-containing monomer is the same as the latex of the carboxyl group-containing nitrile rubber (a1) described above. Can be used. The content ratio of the epoxy group-containing monomer unit in the carboxyl group-containing styrene-butadiene rubber (a2) is preferably 0.1 to 4.0% by weight, more preferably 0.25 to 3.5% by weight. %, More preferably 0.5 to 3.0% by weight. By setting the content of the epoxy group-containing monomer unit in the above range, the obtained molded film such as a dip molded body can be further improved in tensile strength and provided with a high stress retention. be able to.

In addition, the carboxyl group-containing styrene-butadiene rubber (a2) is a copolymerizable other ethylenically unsaturated group other than at least one monomer selected from amide group-containing monomers and epoxy group-containing monomers. The monomer may be copolymerized. Examples of such other copolymerizable ethylenically unsaturated monomers include those similar to the latex of the carboxyl group-containing nitrile rubber (a1) described above. Other than 1,3-butadiene such as isoprene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and chloroprene And conjugated diene monomers. In the carboxyl group-containing styrene-butadiene rubber (a2), the content ratio of other monomer units formed by other ethylenically unsaturated monomers is preferably 10% by weight or less, more preferably 5%. % By weight or less, more preferably 3% by weight or less.

The latex of the carboxyl group-containing styrene-butadiene rubber (a2) used in the present invention can be obtained by copolymerizing a monomer mixture containing the above-mentioned monomers. preferable. The emulsion polymerization method will be described later. *

The latex of carboxyl group-containing conjugated diene rubber (a3) used in the present invention is a copolymer latex obtained by copolymerizing a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer. Further, it may be a latex of a copolymer obtained by copolymerizing another ethylenically unsaturated monomer copolymerizable with these, which is used as necessary.

The content ratio of the conjugated diene monomer unit formed by the conjugated diene monomer in the carboxyl group-containing conjugated diene rubber (a3) is preferably 80 to 98% by weight, more preferably 90 to 98% by weight, More preferably, it is 95 to 97.5% by weight. By setting the content of the conjugated diene monomer unit within the above range, the resulting molded film such as a dip-molded article is excellent in texture and has a greater elongation while having sufficient tensile strength. be able to.

The ethylenically unsaturated carboxylic acid monomer is not particularly limited as long as it is an ethylenically unsaturated monomer containing a carboxyl group. For example, the same as the latex of the carboxyl group-containing nitrile rubber (a1) described above Can be used. In the carboxyl group-containing conjugated diene rubber (a3), the content ratio of the ethylenically unsaturated carboxylic acid monomer unit formed by the ethylenically unsaturated carboxylic acid monomer is preferably 2 to 10% by weight, and more It is preferably 2 to 7.5% by weight, more preferably 2 to 6.5% by weight, even more preferably 2 to 6% by weight, particularly preferably 2 to 5% by weight, and most preferably 2.5 to 5%. % By weight. By setting the content of the ethylenically unsaturated carboxylic acid monomer unit in the above range, the film molded product such as a dip molded product obtained is excellent in texture and stretched while having sufficient tensile strength. Can be big.

Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and chloroprene. Any one of these conjugated diene monomers may be used alone, or two or more may be used in combination.

Further, other ethylenically unsaturated monomers copolymerizable with the conjugated diene monomer and the ethylenically unsaturated carboxylic acid monomer are not particularly limited, but the obtained film molded body such as a dip molded body From the viewpoint that the tensile strength can be further increased and a high stress retention can be provided, at least one monomer selected from an amide group-containing monomer and an epoxy group-containing monomer is used. A body is mentioned suitably.

The amide group-containing monomer is not particularly limited as long as it is a monomer having at least one amide group in one molecule. For example, the same amide group-containing nitrile rubber (a1) latex as described above is used. Can be used. The content ratio of the amide group-containing monomer unit in the carboxyl group-containing conjugated diene rubber (a3) is preferably 0.1 to 5.0% by weight, more preferably 0.25 to 4.5% by weight, More preferably, it is 0.5 to 4.0% by weight. By setting the content of the amide group-containing monomer unit in the above range, the obtained molded film such as a dip molded body can be further improved in tensile strength and provided with a high stress retention. be able to.

The epoxy group-containing monomer is not particularly limited as long as it is a monomer having at least one epoxy group in one molecule. For example, the epoxy group-containing monomer is the same as the latex of the carboxyl group-containing nitrile rubber (a1) described above. Can be used. The content ratio of the epoxy group-containing monomer unit in the carboxyl group-containing conjugated diene rubber (a3) is preferably 0.1 to 4.0% by weight, more preferably 0.25 to 3.5% by weight, More preferably, it is 0.5 to 3.0% by weight. By setting the content of the epoxy group-containing monomer unit in the above range, the obtained molded film such as a dip molded body can be further improved in tensile strength and provided with a high stress retention. be able to.

The carboxyl group-containing conjugated diene rubber (a3) is a copolymerizable other ethylenically unsaturated monomer other than at least one monomer selected from amide group-containing monomers and epoxy group-containing monomers. Such other copolymerizable ethylenically unsaturated monomers may be, for example, those similar to the latex of the carboxyl group-containing nitrile rubber (a1) described above ( However, excluding styrene). In the carboxyl group-containing conjugated diene rubber (a3), the content of other monomer units formed by other ethylenically unsaturated monomers is preferably 10% by weight or less, more preferably 5% by weight. Hereinafter, it is more preferably 3% by weight or less.

The latex of the carboxyl group-containing conjugated diene rubber (a3) used in the present invention is obtained by copolymerizing a monomer mixture containing the above-mentioned monomers, and a method of copolymerization by emulsion polymerization is preferred. The emulsion polymerization method will be described later.

Next, latex of the carboxyl group-containing conjugated diene rubber (A) (latex of carboxyl group-containing nitrile rubber (a1), latex of carboxyl group-containing styrene-butadiene rubber (a2), carboxyl group-containing conjugated diene rubber (a3) The emulsion polymerization method for obtaining the latex will be described.

The latex of the carboxyl group-containing conjugated diene rubber (A) described above can be produced by emulsion polymerization of a monomer mixture containing the above-described monomer by a conventionally known emulsion polymerization method.

The polymerization temperature for carrying out the emulsion polymerization is not particularly limited, and may be selected, for example, in the range of 0 to 75 ° C., preferably in the range of 0 to 50 ° C. From the viewpoint of further increasing the tensile strength, it is preferable to control the temperature of the emulsion polymerization to 0 to 25 ° C., and to control the temperature of the emulsion polymerization to 0 to 25 ° C. to obtain a film molded body such as a dip molded body. The tensile strength can be further increased while the elongation is large and the texture is excellent. From this, the temperature of emulsion polymerization is preferably 0 to 75 ° C., more preferably 0 to 50 ° C., further preferably 0 to 25 ° C., even more preferably 5 to 20 ° C. 15 ° C. is particularly preferred.

A specific emulsion polymerization method is not particularly limited as long as the polymerization can be performed by controlling the polymerization temperature within the above range, and a monomer mixture containing the above-described monomers is used. And can be polymerized by a conventionally known method.

In addition, from the viewpoint of making a film molded body such as a dip molded body excellent in tensile strength, elongation and texture in a balanced manner, when the monomer mixture is subjected to emulsion polymerization, a single amount used for polymerization The emulsion polymerization is preferably performed in the presence of 0.15 to 0.95 parts by weight of a chain transfer agent with respect to 100 parts by weight of the body mixture. The amount of the chain transfer agent used is preferably 0.15 to 0.95 parts by weight, more preferably 0.20 to 0.70 parts by weight, more preferably 100 parts by weight of the monomer mixture used for the polymerization. The amount is preferably 0.20 to 0.50 parts by weight.

Further, when emulsion polymerization of the monomer mixture, by performing emulsion polymerization in the presence of 0.15 to 0.95 parts by weight of a chain transfer agent with respect to 100 parts by weight of the monomer mixture used for polymerization, The molecular weight of the carboxyl group-containing conjugated diene rubber (A) can be adjusted moderately, whereby the amount of carboxyl group-containing conjugated diene rubber (A) insoluble in methyl ethyl ketone and the degree of swelling with respect to methyl ethyl ketone are within a desired range. Thereby, the tensile strength, elongation, and stress at 500% elongation of a film molded body such as a dip molded body can be more highly balanced.

Specifically, the methyl ethyl ketone insoluble content of the carboxyl group-containing conjugated diene rubber (A) can be preferably 50 to 90% by weight, more preferably 55 to 85% by weight. Further, the swelling degree of the carboxyl group-containing conjugated diene rubber (A) with respect to methyl ethyl ketone can be preferably 10 to 150 times, more preferably 10 to 100 times.

The methyl ethyl ketone insoluble content and the degree of swelling with respect to methyl ethyl ketone can be measured, for example, by the following method. That is, first, a film of carboxyl group-containing conjugated diene rubber (A) was obtained, and the weight (W1) of the dried film before being immersed in methyl ethyl ketone was measured, and the film before being immersed in an 80-mesh cage metal mesh In the put state, it is immersed in methyl ethyl ketone for 24 hours at room temperature. Then, the weight (W2) of the swelled film remaining in the cage wire net is measured, and then the film after the immersion is dried at 105 ° C. to remove methyl ethyl ketone, thereby obtaining a dried film. The weight (W3) of the subsequent dry film is measured. And based on the obtained measurement result, it can calculate by following formula (1), (2).
Methyl ethyl ketone insoluble content (unit:% by weight) = (weight of dried film after immersion (W3) / weight of dried film before immersion (W1)) × 100 (1)
Swelling degree with respect to methyl ethyl ketone (unit: times) = (weight of swollen film (W2) / weight of dried film after immersion (W3)) (2)

Further, the chain transfer agent used in the emulsion polymerization is not particularly limited as long as the molecular weight of the obtained carboxyl group-containing conjugated diene rubber (A) can be appropriately adjusted. Examples thereof include mercaptans such as mercaptan and t-dodecyl mercaptan, sulfides such as tetraethylthiuram sulfide and dibentamethylenethiuram hexasulfide, α-methylstyrene dimer, carbon tetrachloride and the like. Of these, mercaptans are preferable, and t-dodecyl mercaptan is more preferable. These may be used individually by 1 type, or may be used in combination of 2 or more type.

In addition, in the emulsion polymerization, in addition to the chain transfer agent described above, commonly used polymerization auxiliary materials such as an emulsifier and a polymerization initiator can be used. The method for adding these polymerization auxiliary materials is not particularly limited, and any method such as an initial batch addition method, a divided addition method, or a continuous addition method may be used.

Although it does not specifically limit as an emulsifier, For example, Nonionic emulsifiers, such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester; potassium dodecylbenzenesulfonate, dodecylbenzene Anionic emulsifiers such as alkyl benzene sulfonates such as sodium sulfonate, higher alcohol sulfates and alkyl sulfosuccinates; Cationic emulsifiers such as alkyltrimethylammonium chloride, dialkylammonium chloride and benzylammonium chloride; α, β-unsaturated Such as sulfo ester of carboxylic acid, sulfate ester of α, β-unsaturated carboxylic acid, sulfoalkyl aryl ether, etc. Or the like can be mentioned a polymerizable emulsifier. Among these, anionic emulsifiers are preferable, alkylbenzene sulfonates are more preferable, and potassium dodecylbenzenesulfonate and sodium dodecylbenzenesulfonate are particularly preferable. These emulsifiers can be used alone or in combination of two or more. The amount of the emulsifier used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the monomer mixture.

The polymerization initiator is not particularly limited, and examples thereof include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, di-α- Organic peroxides such as cumyl peroxide, acetyl peroxide, isobutyryl peroxide, benzoyl peroxide; azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, methyl azobisisobutyrate; Can be mentionedThese polymerization initiators can be used alone or in combination of two or more. The amount of the polymerization initiator used is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the monomer mixture.

Also, the peroxide initiator can be used as a redox polymerization initiator in combination with a reducing agent. The reducing agent is not particularly limited, but is a compound containing a metal ion in a reduced state such as ferrous sulfate or cuprous naphthenate; a sulfonic acid compound such as sodium methanesulfonate; an amine compound such as dimethylaniline. And so on. These reducing agents can be used alone or in combination of two or more. The amount of the reducing agent used is preferably 3 to 1000 parts by weight with respect to 100 parts by weight of the peroxide.

The amount of water used for emulsion polymerization is preferably 80 to 600 parts by weight, particularly preferably 100 to 200 parts by weight, based on 100 parts by weight of all monomers used.

Examples of the monomer addition method include a method of adding monomers to be used in a reaction vessel all at once, a method of adding continuously or intermittently as the polymerization proceeds, and a part of the monomer is added. And a method in which the remaining monomer is continuously or intermittently added and polymerized, and any method may be employed. When the monomers are mixed and added continuously or intermittently, the composition of the mixture may be constant or may be changed. Each monomer may be added to the reaction vessel after previously mixing various monomers to be used, or may be added separately to the reaction vessel.

Furthermore, if necessary, polymerization auxiliary materials such as a chelating agent, a dispersant, a pH adjuster, an oxygen scavenger, and a particle size adjuster can be used, and these are not particularly limited in type and amount used.

The polymerization time for carrying out the emulsion polymerization is not particularly limited, but is usually about 5 to 40 hours.

As described above, the monomer mixture is emulsion-polymerized, and when the predetermined polymerization conversion rate is reached, the polymerization reaction is stopped by cooling the polymerization system or adding a polymerization terminator. The polymerization conversion rate when stopping the polymerization reaction is preferably 90% by weight or more, more preferably 93% by weight or more.

The polymerization terminator is not particularly limited. For example, hydroxylamine, hydroxyamine sulfate, diethylhydroxylamine, hydroxyaminesulfonic acid and its alkali metal salt, sodium dimethyldithiocarbamate, hydroquinone derivative, catechol derivative, and hydroxydimethyl Examples thereof include aromatic hydroxydithiocarboxylic acids such as benzenethiocarboxylic acid, hydroxydiethylbenzenedithiocarboxylic acid, hydroxydibutylbenzenedithiocarboxylic acid, and alkali metal salts thereof. The amount of the polymerization terminator used is preferably 0.05 to 2 parts by weight with respect to 100 parts by weight of the monomer mixture.

After stopping the polymerization reaction, if desired, the unreacted monomer is removed, and the solid content concentration and pH are adjusted so that the latex of the carboxyl group-containing conjugated diene rubber (A) (the carboxyl group-containing nitrile described above) is obtained. Rubber (a1) latex, carboxyl group-containing styrene-butadiene rubber (a2) latex, and carboxyl group-containing conjugated diene rubber (a3) latex).

In addition, an anti-aging agent, an antiseptic, an antibacterial agent, a dispersant, and the like may be appropriately added to the carboxyl group-containing conjugated diene rubber (A) latex used in the present invention, if necessary.

The number average particle diameter of the latex of the carboxyl group-containing conjugated diene rubber (A) used in the present invention is preferably 60 to 300 nm, more preferably 80 to 150 nm. The particle diameter can be adjusted to a desired value by a method such as adjusting the amount of emulsifier and polymerization initiator used.

Metal compound containing a trivalent or higher metal (B)
The latex composition of the present invention comprises a metal compound (B) containing a trivalent or higher metal in addition to the carboxyl group-containing conjugated diene rubber (A) latex described above. The content ratio of the metal compound (B) containing a trivalent or higher metal to 100 parts by weight of the carboxyl group-containing conjugated diene rubber (A) is in the range of 0.1 to 1.5 parts by weight. . In the latex composition of the present invention, the metal compound (B) containing a trivalent or higher metal acts as a crosslinking agent.

According to the present invention, a metal compound (B) containing a trivalent or higher metal is used as a cross-linking agent instead of sulfur that is usually used as a cross-linking agent. Because it does not require a sulfur accelerator, in addition to immediate type allergy (Type I), it may cause delayed type allergy (Type IV) due to sulfur and sulfur-containing vulcanization accelerators. It can be effectively suppressed.

In addition, according to the present invention, the above-mentioned specific amount of the metal compound (B) containing a trivalent or higher metal is contained in the latex of the carboxyl group-containing conjugated diene rubber (A), so that a dip-molded body or the like is obtained. When the film molded body is obtained, the obtained film molded body such as a dip molded body can be provided with a soft texture in addition to high tensile strength and high elongation. In particular, when a film molded body such as a dip molded body is used for a glove application, in addition to high tensile strength and large elongation, a feeling of use when a user wears this and works is important. Is. And when the present inventors examined such a usability | use_condition, they discovered that it was desirable that it was excellent also in the texture (low stress at the time of 500% expansion | extension).

The metal compound (B) containing a trivalent or higher metal is not particularly limited as long as it is a compound containing a trivalent or higher metal, and examples thereof include an aluminum compound, a cobalt compound, a zirconium compound, and a titanium compound. Among these, an aluminum compound is preferable from the viewpoint that the carboxyl group-containing conjugated diene rubber (A) contained in the latex can be more favorably crosslinked.

The aluminum compound is not particularly limited. For example, aluminum oxide, aluminum chloride, aluminum hydroxide, aluminum nitrate, aluminum sulfate, aluminum metal, aluminum ammonium sulfate, aluminum bromide, aluminum fluoride, aluminum sulfate / potassium, aluminum Examples thereof include isopropoxide, sodium aluminate, potassium aluminate, and sodium aluminum sulfite. In addition, these aluminum compounds can be used individually or in combination of 2 or more types. Among these, sodium aluminate is preferable from the viewpoint that the effects of the present invention can be made more remarkable.

The content ratio of the metal compound (B) containing a trivalent or higher valent metal in the latex composition of the present invention is 0.100 parts by weight with respect to 100 parts by weight of the carboxyl group-containing conjugated diene rubber (A) contained in the latex. 1 to 1.5 parts by weight, preferably 0.1 to 1.25 parts by weight, more preferably 0.1 to 1 part by weight, still more preferably 0.1 to 0.8 parts by weight, Particularly preferred is 0.1 to 0.6 parts by weight. If the content ratio of the metal compound containing a trivalent or higher metal is too small, the crosslinking becomes insufficient, and the obtained film molded body such as a dip molded body is inferior in tensile strength. When a film molded body such as a dip molded body is obtained, the obtained film molded body such as a dip molded body has a small elongation and a poor texture.

Alcoholic hydroxyl group-containing compound (C)
Moreover, in addition to the latex of the carboxyl group-containing conjugated diene rubber (A) and the metal compound (B) containing a trivalent or higher metal, the latex composition of the present invention includes a saccharide (c1), a sugar alcohol ( It is preferable to contain at least one alcoholic hydroxyl group-containing compound (C) selected from c2), hydroxy acid (c3) and hydroxy acid salt (c4).

By further containing the alcoholic hydroxyl group-containing compound (C), the stability as a latex composition can be further improved, and when it is formed into a film molded body such as a dip molded body, the dip molded body obtained, etc. In addition to having a high tensile strength, a large elongation, and a soft texture, the film molded body can be provided with a high stress retention.

In particular, when using a metal compound (B) containing a trivalent or higher metal as a crosslinking agent, an alcoholic hydroxyl group-containing compound (C) is blended with such a metal compound (B) containing a trivalent or higher metal. By doing so, the dispersion state of the metal compound (B) containing a trivalent or higher metal in the latex composition can be made better, and thereby the stability as the latex composition is made better. A film molded body such as a dip molded body obtained by the action of the metal compound (B) containing a trivalent or higher metal and the alcoholic hydroxyl group-containing compound (C), In addition to having a high tensile strength, a high elongation, and a soft texture, it can also have a high stress retention.

In particular, when a film molded body such as a dip molded body is used for a glove application, as described above, the tensile strength is high and the elongation is large from the viewpoint of a feeling of use when this is worn and the work is performed. In addition, it is important to have a soft texture, but from the viewpoint of further improving the feeling of use, it is possible to effectively prevent looseness and sagging from occurring over time after installation (that is, a dip molded body). for film compacts tensile stretched 100% stress M _100, such as _(0), the high stress retention represented by a percentage of stretch to stop to six minutes later stress M _{100 (6))} Gayori preferable. Therefore, from such a viewpoint, in addition to the latex of the carboxyl group-containing conjugated diene rubber (A) and the metal compound (B) containing a trivalent or higher metal, the alcoholic hydroxyl group-containing compound (C) is further added. It is preferable to mix, and thereby, the film composition such as a dip-molded body obtained with good stability as a latex composition has high tensile strength, large elongation, and stress at 500% elongation. In addition to being excellent in (texture), it can have a high stress retention.

The alcoholic hydroxyl group-containing compound (C) used in the present invention is at least one selected from saccharide (c1), sugar alcohol (c2), hydroxy acid (c3) and hydroxy acid salt (c4). From the viewpoint that the obtained film molded body such as a dip molded body can have a softer texture and a higher stress retention, sugar alcohol (c2) and hydroxy acid salt (c4) It is preferable to use at least one selected from When two or more alcoholic hydroxyl group-containing compounds (C) are used in combination, at least one selected from saccharide (c1) and sugar alcohol (c2), hydroxy acid (c3) and hydroxy acid salt It is preferable to use a combination of at least one selected from (c4), and it is more preferable to use a combination of sugar alcohol (c2) and hydroxy acid salt (c4).

The saccharide (c1) is not particularly limited as long as it is a monosaccharide or a polysaccharide in which two or more monosaccharides are bonded by a glycosidic bond. For example, erythrose, sreose, ribose, lyxose, xylose, arabinose, allose , Talose, growth, altrose, galactose, idose, erythrulose, xylulose, ribulose, psicose, fructose, sorbose, tagatose, monosaccharides; trehalose, maltose, isomaltose, cellobiose, gentiobiose, melibiose, lactose, sucrose, palatinose, etc. Disaccharides of: maltotriose, isomaltotriose, panose, cellotriose, manninotriose, solatriose, melezitose, planteose, gentianose, Trisaccharides such as umbelliferose, lactosucrose, and raffinose; homo-oligosaccharides such as maltotetraose and isomalttetraose; tetrasaccharides such as stachyose, cellotetraose, scorodose, liquinose, and panose; and maltopentaose and isomaltopentaose Pentasaccharides; hexasaccharides such as maltohexaose and isomalthexaose; and the like. These may be used individually by 1 type, or may be used in combination of 2 or more type.

The sugar alcohol (c2) is not particularly limited as long as it is a monosaccharide or polysaccharide sugar alcohol; for example, tritol such as glycerin; tetritol such as erythritol, D-threitol, L-threitol; D-arabinitol, Pentitols such as L-arabinitol, xylitol, ribitol, pentaerythritol; pentaerythritol; hexitols such as sorbitol, D-iditol, galactitol, D-glucitol, mannitol; heptitols such as boleitol, perseitol; D-erythro-D- Octitol such as galacto-octitol; and the like. These may be used individually by 1 type, or may be used in combination of 2 or more type. Among these, hexitol which is a sugar alcohol having 6 carbon atoms is preferable, and sorbitol is more preferable.

The hydroxy acid (c3) is not particularly limited as long as it is a carboxylic acid having a hydroxyl group. For example, glycolic acid, lactic acid, tartronic acid, glyceric acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, γ-hydroxy Aliphatic acids such as butyric acid, malic acid, 3-methylmalic acid, tartaric acid, citramalic acid, citric acid, isocitric acid, leucine acid, mevalonic acid, pantoic acid, ricinoleic acid, ricinaleic acid, cerebronic acid, quinic acid, shikimic acid, serine Hydroxy acid; salicylic acid, creosote acid (homosalicylic acid, hydroxy (methyl) benzoic acid), vanillic acid, syringic acid, hydroxypropanoic acid, hydroxypentanoic acid, hydroxyhexanoic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, hydroxynonanoic acid, Hydroxyde Monohydroxy such as acid, hydroxyundecanoic acid, hydroxydododecanoic acid, hydroxytridecanoic acid, hydroxytetradecanoic acid, hydroxypentadecanoic acid, hydroxyheptadecanoic acid, hydroxyoctadecanoic acid, hydroxynonadecanoic acid, hydroxyicosanoic acid, ricinoleic acid Benzoic acid derivatives, pyrocatechuic acid, resorcylic acid, protocatechuic acid, dihydroxybenzoic acid derivatives such as gentisic acid, orthothelic acid, trihydroxybenzoic acid derivatives such as gallic acid, phenylacetic acid derivatives such as mandelic acid, benzylic acid, atrolactic acid, And aromatic hydroxy acids such as cinnamic acid and hydrocinnamic acid derivatives such as mellitoic acid, furoletic acid, coumaric acid, umbelic acid, caffeic acid, ferulic acid, and sinapinic acid. These may be used individually by 1 type, or may be used in combination of 2 or more type. Among these, aliphatic hydroxy acids are preferable, aliphatic α-hydroxy acids are more preferable, glycolic acid, lactic acid, tartronic acid, glyceric acid, malic acid, tartaric acid, and citric acid are more preferable, and glycolic acid is particularly preferable.

The hydroxy acid salt (c4) is not particularly limited as long as it is a salt of a hydroxy acid, and examples thereof include metal salts of hydroxy acid exemplified as specific examples of the hydroxy acid (c3), such as sodium and potassium. And alkali metal salts such as calcium and magnesium. As the hydroxy acid salt (c4), one kind may be used alone, or two or more kinds may be used in combination. As the hydroxy acid salt (c4), an alkali metal salt of hydroxy acid is preferable, and a sodium salt of hydroxy acid is preferable. The hydroxy acid constituting the hydroxy acid salt (c4) is preferably an aliphatic hydroxy acid, more preferably an aliphatic α-hydroxy acid, glycolic acid, lactic acid, tartronic acid, glyceric acid, malic acid, tartaric acid, citric acid. An acid is further preferred, and glycolic acid is particularly preferred. That is, sodium glycolate is particularly suitable as the hydroxy acid salt (c4).

The content of the alcoholic hydroxyl group-containing compound (C) in the latex composition of the present invention is “the metal compound (B) containing a trivalent or higher metal” relative to the metal compound (B) containing a trivalent or higher metal. : Alcoholic hydroxyl group-containing compound (C) ", preferably in an amount ranging from 1: 0.1 to 1:50, more preferably from 1: 0.2 to 1:45. The amount is more preferably in the range of 1: 0.3 to 1:30. By setting the content of the alcoholic hydroxyl group-containing compound (C) to the above range relative to the metal compound (B) containing a trivalent or higher metal, the effect of adding the alcoholic hydroxyl group-containing compound (C) can be further enhanced. .

The content of the alcoholic hydroxyl group-containing compound (C) may be such that the content with respect to the metal compound (B) containing a trivalent or higher metal falls within the above range, but the carboxyl group contained in the latex The content with respect to 100 parts by weight of the conjugated diene rubber (A) is preferably 0.03 to 15 parts by weight, and more preferably 0.05 to 10 parts by weight.

The latex composition of the present invention includes, for example, a metal compound (B) containing a trivalent or higher metal in a latex of a carboxyl group-containing conjugated diene rubber (A), and an alcoholic hydroxyl group-containing compound (if necessary) ( And C). As a method of blending the latex of the carboxyl group-containing conjugated diene rubber (A) with the metal compound (B) containing a trivalent or higher metal and the alcoholic hydroxyl group-containing compound (C) used as necessary, Although it is not particularly limited, the metal compound (B) containing a trivalent or higher metal and the alcoholic hydroxyl group-containing compound (C) used as necessary can be favorably dispersed in the obtained latex composition. More preferably, the metal compound (B) containing a trivalent or higher metal and the alcoholic hydroxyl group-containing compound (C) used as necessary are dissolved in water or alcohol and added in the form of an aqueous solution or alcohol solution. In addition, it is preferable to add a stabilizer such as a chelating agent or a buffering agent in order to increase the stability of the solution when dissolved.

In addition, the latex composition of the present invention contains a latex of the carboxyl group-containing conjugated diene rubber (A) described above, a metal compound (B) containing a trivalent or higher metal, and an alcoholic hydroxyl group used as necessary. In addition to the compound (C), a filler, a pH adjuster, a thickener, an anti-aging agent, a dispersant, a pigment, a filler, a softener and the like may be blended as desired.

The solid content concentration of the latex composition of the present invention is preferably 10 to 40% by weight, more preferably 15 to 35% by weight. The pH of the latex composition of the present invention is preferably 7.5 to 12.0, more preferably 7.5 to 11.0, still more preferably 7.5 to 9.4, particularly preferably 7.5. ~ 9.2.

Dip molded body The dip molded body of the present invention can be obtained by dip molding the latex composition of the present invention described above.
As the dip molding method, a normal method may be employed, and examples thereof include a direct dipping method, an anode adhesion dipping method, and a teag adhesion dipping method. Of these, the anode coagulation dipping method is preferable in that a dip-formed body having a uniform thickness is easily obtained.

In the case of the anode adhesion dipping method, for example, a dip-molding mold is dipped in a coagulant solution to attach a coagulant to the mold surface, and then dipped in a latex composition to dip on the mold surface. A molding layer is formed.

Examples of the coagulant include metal halides such as barium chloride, calcium chloride, magnesium chloride, zinc chloride, and aluminum chloride; nitrates such as barium nitrate, calcium nitrate, and zinc nitrate; acetic acid such as barium acetate, calcium acetate, and zinc acetate. Salts; sulfates such as calcium sulfate, magnesium sulfate, and aluminum sulfate; and the like. Of these, calcium chloride and calcium nitrate are preferred.
The coagulant is usually used as a solution of water, alcohol, or a mixture thereof. The coagulant concentration is usually 5 to 50% by weight, preferably 10 to 35% by weight.

The obtained dip-molded layer is usually subjected to heat treatment to be crosslinked. Prior to the heat treatment, water-soluble impurities (for example, excess emulsifier and coagulant) may be removed by immersing in water, preferably warm water of 30 to 70 ° C., for about 1 to 60 minutes. The operation for removing the water-soluble impurities may be performed after the dip-molded layer is heat-treated, but it is preferably performed before the heat-treatment because the water-soluble impurities can be more efficiently removed.

The crosslinking of the dip-molded layer is usually performed by performing a heat treatment at a temperature of 80 to 150 ° C., preferably 10 to 130 minutes. As a heating method, an external heating method using infrared rays or heated air or an internal heating method using high frequency can be employed. Of these, external heating with heated air is preferred.

Then, the dip molded body is obtained as a film-shaped film molded body by detaching the crosslinked dip molded layer from the dip molding die. As the desorption method, it is possible to adopt a method of peeling from the mold by hand, or peeling by water pressure or compressed air pressure. After the desorption, a heat treatment may be further performed at a temperature of 60 to 120 ° C. for 10 to 120 minutes.
The film thickness of the film molded body is preferably 0.03 to 0.50 mm, more preferably 0.05 to 0.40 mm, and particularly preferably 0.08 to 0.30 mm. In addition to the method of dip-molding the latex composition of the present invention described above, the film molded body of the present invention is a method that can form the latex composition of the present invention into a film (for example, a coating method, etc.). ) As long as it is obtained by any method.

Since the film molded body of the present invention including the dip molded body of the present invention is obtained using the above-described latex composition of the present invention, in addition to immediate allergy (Type I), delayed allergy (Type IV) ) Is also suppressed, and the tensile strength is high, the elongation is large, and a soft texture is provided. Therefore, it is suitable for glove use, particularly for surgical gloves. Alternatively, the membrane molded body of the present invention including the dip molded body of the present invention is a medical product such as a baby bottle nipple, a dropper, a tube, a water pillow, a balloon sack, a catheter, and a condom in addition to gloves; a balloon, a doll, It can also be used for toys such as balls; industrial articles such as pressure forming bags and gas storage bags;

Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples. In the following, “part” is based on weight unless otherwise specified. The test and evaluation were as follows.

Tensile strength, elongation at break, rubber gloves as a dip molded product obtained in stress examples and comparative examples at 500% elongation, ASTM D-412 dumbbell according to (Die-C: manufactured by Dumbbell Co., Ltd.) using Thus, a dumbbell-shaped test piece was produced. Subsequently, the obtained test piece was pulled at a tensile speed of 500 mm / min, and the tensile strength at break, the elongation at break, and the stress at 500% elongation were measured. Further, higher tensile strength and elongation at break are more preferable. Further, the smaller the stress at the time of 500% elongation, the more flexible the texture, so that it is preferable.

Rubber gloves as dip molded product obtained in stress retention Examples and Comparative Examples, dumbbell according to ASTM D-412: with (Die-C manufactured by Dumbbell Co., Ltd.), to prepare a test piece of dumbbell shape Then, tensile stress was applied to both ends of the test piece at a speed of 500 mm / min, and when the standard section 20 mm of the test piece was doubled (100%), the extension was stopped and the tensile stress M ₁₀₀ (0) was measured. In addition, the tensile stress M ₁₀₀ (6) after 6 minutes was measured as it was. _Then, the _{M 100} percent of _{M 100} (6) with respect to (0) _{_{(i.e., M 100 (6) / M}} 100 (0) in percentage) the stress retention. The larger the stress retention rate, the more preferable it is because the sag (loosening or sagging) associated with the use of gloves does not easily occur. The stress retention rate was measured in Examples 2-1 to 2-9, 3-1 to 3-9, 4-1 to 4-8, and Comparative Examples 2-1 to 2-3, 4-1, 4 -2.

Production Example 1
Production of latex of carboxyl group-containing nitrile rubber (a1-1) In a polymerization reactor, 34 parts of acrylonitrile, 62.5 parts of 1,3-butadiene, 3.5 parts of methacrylic acid, 0.4 part of t-dodecyl mercaptan, ion 132 parts of exchanged water, 3 parts of sodium dodecylbenzenesulfonate, 0.5 part of sodium salt of β-naphthalenesulfonic acid formalin condensate, 0.3 part of potassium persulfate and 0.05 part of sodium ethylenediaminetetraacetate were added, and the polymerization temperature was adjusted. The polymerization was started while maintaining at 37 ° C. Then, when the polymerization conversion rate becomes 70%, the polymerization temperature is raised to 44 ° C., and the reaction is continued until the polymerization conversion rate becomes 95%. Thereafter, sodium dimethyldithiocarbamate as a polymerization terminator is used. The polymerization reaction was stopped by adding 1 part. Then, after the unreacted monomer was distilled off under reduced pressure from the obtained copolymer latex, the solid content concentration and pH were adjusted, and the carboxyl group-containing nitrile rubber having a solid content concentration of 40% and pH 7.5 ( A latex of a1-1) was obtained. The composition of the carboxyl group-containing nitrile rubber (a1-1) contained in the obtained latex is 34.0% by weight of acrylonitrile units, 62.5% by weight of 1,3-butadiene units, and 3.5% by weight of methacrylic acid units. Met.

Production Example 2
36 parts from 34 parts amount of the preparation acrylonitrile latex of the carboxyl group-containing nitrile rubber (a1-2), 61 parts of the usage 62.5 parts of 1,3-butadiene, the amount of methacrylic acid 3 A latex of carboxyl group-containing nitrile rubber (a1-2) having a solid content of 40% and a pH of 7.5 was obtained in the same manner as in Production Example 1, except that the amount was changed from 5 parts to 3 parts. The composition of the carboxyl group-containing nitrile rubber (a1-2) contained in the obtained latex is 36.0% by weight of acrylonitrile units, 61.0% by weight of 1,3-butadiene units, and 3.0% by weight of methacrylic acid units. Met.

Production Example 3
Production of latex of carboxyl group-containing nitrile rubber (a1-3) The amount of acrylonitrile used was changed from 34 parts to 28.0 parts, and the amount of 1,3-butadiene used was changed from 62.5 parts to 68.5 parts. Except for the above, a latex of carboxyl group-containing nitrile rubber (a1-3) having a solid content of 40% and a pH of 7.5 was obtained in the same manner as in Production Example 1. The composition of the carboxyl group-containing nitrile rubber (a1-3) contained in the obtained latex was as follows: acrylonitrile unit 28.0% by weight, 1,3-butadiene unit 68.5% by weight, methacrylic acid unit 3.5% by weight. Met.

Production Example 4
Production of latex of carboxyl group-containing nitrile rubber (a1-4) The amount of acrylonitrile used was changed from 34 parts to 30.5 parts, the amount of 1,3-butadiene used was changed from 62.5 parts to 63.5 parts, The amount used was changed from 3.5 parts to 6 parts, respectively, and the pH after the unreacted monomer was distilled off under reduced pressure from the obtained copolymer latex was changed from 7.5 to 7.0. A latex of carboxyl group-containing nitrile rubber (a1-4) having a solid content concentration of 40% and a pH of 7.0 was obtained in the same manner as in Production Example 1 except for the change. The composition of the carboxyl group-containing nitrile rubber (a1-4) contained in the obtained latex is 30.5% by weight of acrylonitrile units, 63.5% by weight of 1,3-butadiene units, and 6.0% by weight of methacrylic acid units. Met.

Production Example 5
Production of latex of carboxyl group-containing nitrile rubber (a1-5) In a pressure-resistant polymerization reaction vessel equipped with a stirrer, 63 parts of 1,3-butadiene, 34 parts of acrylonitrile, 3 parts of methacrylic acid, t-dodecyl mercaptan as a chain transfer agent 25 parts, 132 parts of deionized water, 3 parts of sodium dodecylbenzenesulfonate, 1 part of sodium β-naphthalenesulfonate formalin condensate, 0.3 part of potassium persulfate, and 0.005 part of sodium ethylenediaminetetraacetate were polymerized. The temperature was maintained at 37 ° C. to initiate polymerization. Then, when the polymerization conversion rate becomes 70%, the polymerization temperature is raised to 43 ° C., and the reaction is continued until the polymerization conversion rate becomes 95%. Thereafter, sodium dimethyldithiocarbamate 0% as a polymerization terminator is used. The polymerization reaction was stopped by adding 1 part. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing nitrile rubber (a1-5) was obtained. The composition of the obtained carboxyl group-containing nitrile rubber (a1-5) was 63% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, and 3% by weight of methacrylic acid units.

Production Example 6
Production of latex of carboxyl group-containing styrene-butadiene rubber (a2-1) In a pressure-resistant vessel equipped with a stirrer, 50 parts of deionized water, 0.3 part of sodium dodecylbenzenesulfonate, 0.4 part of t-dodecyl mercaptan, 1, A monomer emulsion was obtained by charging 63 parts of 3-butadiene, 34 parts of styrene, and 3 parts of methacrylic acid. Separately, in a pressure-resistant polymerization reaction vessel equipped with a stirrer, 40 parts of deionized water, 0.2 part of sodium dodecylbenzenesulfonate, 0.35 part of sodium bicarbonate and 0.05 part of sodium ethylenediaminetetraacetate were charged and mixed. The temperature was raised to 70 ° C. And after adding 0.5 parts of potassium persulfate to this, addition of the monomer emulsion obtained above was started immediately, and it added continuously over 5 hours, stirring and mixing. After the addition of the monomer emulsion, 0.2 part of potassium persulfate was added as a 3 wt% aqueous solution. When the polymerization conversion reached 90%, the temperature was raised to 85 ° C and the reaction was continued for another 3 hours. When the polymerization conversion rate was 95%, 0.1 part of sodium dimethyldithiocarbamate was added as a polymerization terminator to terminate the polymerization reaction. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing styrene-butadiene rubber (a2-1) was obtained. The composition of the obtained carboxyl group-containing styrene-butadiene rubber (a2-1) was 63% by weight of 1,3-butadiene units, 34% by weight of styrene units, and 3% by weight of methacrylic acid units.

Production Example 7
In a pressure-resistant polymerization reactor equipped with a latex stirrer of carboxyl group-containing butadiene rubber (a3-1), 97 parts of 1,3-butadiene, 3 parts of methacrylic acid, 0.8 part of t-dodecyl mercaptan as a chain transfer agent, deionized water 132 parts, sodium dodecylbenzenesulfonate 3 parts, β-naphthalenesulfonic acid formalin condensate 1 part, potassium persulfate 0.3 part, and ethylenediaminetetraacetate 0.005 part are charged, and the polymerization temperature is maintained at 37 ° C. Then, polymerization was started. Then, when the polymerization conversion rate becomes 70%, the polymerization temperature is raised to 43 ° C., and the reaction is continued until the polymerization conversion rate becomes 95%. Thereafter, sodium dimethyldithiocarbamate 0% as a polymerization terminator is used. The polymerization reaction was stopped by adding 1 part. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing butadiene rubber (a3-1) was obtained. The composition of the obtained carboxyl group-containing butadiene rubber (a3-1) was 97% by weight of 1,3-butadiene units and 3% by weight of methacrylic acid units.

Production Example 8
Production of latex of carboxyl group-containing nitrile rubber (a1-6) In a pressure-resistant polymerization reaction vessel equipped with a stirrer, 63 parts of 1,3-butadiene, 34 parts of acrylonitrile, 3 parts of methacrylic acid, t-dodecyl mercaptan as a chain transfer agent 25 parts, 132 parts of deionized water, 3 parts of sodium dodecylbenzenesulfonate, 1 part of sodium β-naphthalenesulfonate formalin condensate and 0.01 part of sodium hyposulfite were charged, and the polymerization reaction vessel temperature was maintained at 5 ° C. Thereafter, 6 parts of ion-exchanged water, 0.020 part of ethylenediaminetetraacetate, 0.002 part of ferrous sulfate, and 0.003 part of sodium formaldehyde sulfoxylate were added to the polymerization reaction vessel, and 1,1 Then, 0.004 part of 3,3-tetramethylbutyl hydroperoxide was added and the temperature was maintained at 5 ° C. to initiate the polymerization. And it was made to react until the polymerization conversion rate became 95%, and 0.1 part of sodium dimethyldithiocarbamate was then added as a polymerization terminator to terminate the polymerization reaction. During the polymerization reaction, the temperature of the reaction system was kept in the range of 5 to 10 ° C. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing nitrile rubber (a1-6) was obtained. The carboxyl group-containing nitrile rubber (a1-6) contained in the obtained latex was measured for the amount of methyl ethyl ketone insoluble matter and the degree of swelling with respect to methyl ethyl ketone. As a result, the amount of methyl ethyl ketone insoluble matter was 80% by weight and the degree of swelling with respect to methyl ethyl ketone was 45 times. there were. The composition of the obtained carboxyl group-containing nitrile rubber (a1-6) was 63% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, and 3% by weight of methacrylic acid units.

Production Example 9
Production of latex of carboxyl group-containing styrene-butadiene rubber (a2-1) In a pressure-resistant polymerization reaction vessel equipped with a stirrer, 63 parts of 1,3-butadiene, 34 parts of styrene, 3 parts of methacrylic acid, t-dodecyl mercaptan as a chain transfer agent 0.4 parts, 132 parts of deionized water, 1.5 parts of sodium dodecylbenzenesulfonate, 1 part of β-naphthalenesulfonic acid formalin condensate and 0.01 part of sodium hyposulfite were charged, and the temperature of the polymerization reaction vessel was 10. Held at 0C. Thereafter, a mixture of 6 parts of ion exchanged water, 0.05 part of sodium ethylenediaminetetraacetate, 0.006 part of ferrous sulfate and 0.05 part of sodium formaldehyde sulfoxylate was added to the polymerization reaction vessel, and diisopropylbenzene hydro 0.15 parts of peroxide was added and the temperature was maintained at 10 ° C. to initiate polymerization. When the polymerization conversion reached 50% and 70%, 1.2 parts of deionized water and 0.5 part of sodium dodecylbenzenesulfonate were added to the polymerization reaction vessel. And it was made to react until the polymerization conversion rate became 95%, and 0.1 part of sodium dimethyldithiocarbamate was then added as a polymerization terminator to terminate the polymerization reaction. During the polymerization reaction, the temperature of the reaction system was kept in the range of 10 to 15 ° C. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing styrene-butadiene rubber (a2-2) was obtained. The carboxyl group-containing styrene-butadiene rubber (a2-2) contained in the obtained latex was measured for the insoluble content of methyl ethyl ketone and the degree of swelling with respect to methyl ethyl ketone. As a result, the insoluble amount of methyl ethyl ketone was 70% by weight and the degree of swelling with respect to methyl ethyl ketone was 60%. It was twice. The composition of the obtained carboxyl group-containing styrene-butadiene rubber (a2-2) was 63% by weight of 1,3-butadiene units, 34% by weight of styrene units, and 3% by weight of methacrylic acid units.

Production Example 10
In a pressure-resistant polymerization reaction vessel equipped with a latex stirrer of carboxyl group-containing butadiene rubber (a3-2), 97 parts of 1,3-butadiene, 3 parts of methacrylic acid, 0.4 part of t-dodecyl mercaptan as a chain transfer agent, deionized water 135 parts, 1.5 parts of sodium dodecylbenzenesulfonate, 1 part of sodium β-naphthalenesulfonate formalin condensate and 0.01 part of sodium hyposulfite were charged, and the temperature of the polymerization reaction vessel was maintained at 10 ° C. Thereafter, a mixture of 6 parts of ion exchange water, 0.02 part of sodium ethylenediaminetetraacetate, 0.008 part of ferrous sulfate and 0.05 part of sodium formaldehyde sulfoxylate was added to the polymerization reaction vessel, and diisopropylbenzene hydro The polymerization was started by adding 0.05 part of peroxide and maintaining the temperature at 10 ° C. When the polymerization conversion reached 60% and 80%, 1.2 parts of deionized water and 0.5 part of sodium dodecylbenzenesulfonate were added to the polymerization reaction vessel. When the polymerization conversion rate reached 60%, 0.01 part of diisopropylbenzene hydroperoxide was added. And it was made to react until the polymerization conversion rate became 95%, and 0.1 part of sodium dimethyldithiocarbamate was then added as a polymerization terminator to terminate the polymerization reaction. During the polymerization reaction, the temperature of the reaction system was kept in the range of 10 to 15 ° C. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing butadiene rubber (a3-2) was obtained. The carboxyl group-containing butadiene rubber (a3-2) contained in the obtained latex was measured for the insoluble content of methyl ethyl ketone and the degree of swelling with respect to methyl ethyl ketone. As a result, the insoluble amount of methyl ethyl ketone was 65% by weight and the degree of swelling with respect to methyl ethyl ketone was 80 times. there were. The composition of the resulting carboxyl group-containing butadiene rubber (a3-2) was 97% by weight of 1,3-butadiene units and 3% by weight of methacrylic acid units.

Production Example 11
Production of latex of carboxyl group-containing nitrile rubber (a1-7) Carboxyl group-containing nitrile rubber in the same manner as in Production Example 5, except that the amount of t-dodecyl mercaptan used as a chain transfer agent was changed to 0.50 parts. A latex (a1-7) was obtained. The carboxyl group-containing nitrile rubber (a1-7) contained in the obtained latex was measured for the insoluble content of methyl ethyl ketone and the degree of swelling with respect to methyl ethyl ketone. As a result, the insoluble amount of methyl ethyl ketone was 75% by weight and the degree of swelling with respect to methyl ethyl ketone was 30 times. there were. The composition of the obtained carboxyl group-containing nitrile rubber (a1-7) was 63% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, and 3% by weight of methacrylic acid units.

Production Example 12
Except for changing the amount of t- dodecylmercaptan as a manufacturing chain transfer agent of the latex of the carboxyl group-containing nitrile rubber (A1-8) to 0.80 parts, in the same manner as in Preparation Example 5, a carboxyl group-containing nitrile rubber A latex (a1-8) was obtained. The carboxyl group-containing nitrile rubber (a1-8) contained in the obtained latex was measured for the amount of methyl ethyl ketone insoluble matter and the degree of swelling with respect to methyl ethyl ketone. As a result, the amount of methyl ethyl ketone insoluble matter was 55% by weight and the degree of swelling with respect to methyl ethyl ketone was 60 times. there were. The composition of the obtained carboxyl group-containing nitrile rubber (a1-8) was 63% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, and 3% by weight of methacrylic acid units.

Production Example 13
Production of latex of carboxyl group-containing nitrile rubber (a1-9) In a pressure-resistant polymerization reaction vessel equipped with a stirrer, 62.5 parts of 1,3-butadiene, 34 parts of acrylonitrile, 3 parts of methacrylic acid, as an amide group-containing monomer N-methylolacrylamide 0.5 part, t-dodecyl mercaptan 0.25 part as chain transfer agent, deionized water 132 parts, sodium dodecylbenzenesulfonate 3 parts, sodium β-naphthalenesulfonate formalin condensate 1 part, The polymerization reaction vessel temperature was maintained at 5 ° C. Thereafter, 6 parts of ion-exchanged water, 0.020 part of ethylenediaminetetraacetate, 0.002 part of ferrous sulfate, and 0.003 part of sodium formaldehyde sulfoxylate were added to the polymerization reaction vessel, and 1,1 Polymerization was initiated by adding 0.004 part of 3,3-tetramethylbutyl hydroperoxide. The reaction was continued until the polymerization conversion reached 95%, and then 0.1 part of sodium dimethyldithiocarbamate was added as a polymerization terminator to terminate the polymerization reaction. Then, after the unreacted monomer is distilled off under reduced pressure from the obtained copolymer latex, the solid content concentration and pH are adjusted, and the carboxyl group-containing nitrile rubber having a solid content concentration of 40% by weight and pH 8.0. A latex (a1-9) was obtained. The composition of the obtained carboxy group-containing nitrile rubber (a1-9) was 62.5% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, 3% by weight of methacrylic acid units, 0.5% of N-methylolacrylamide units. % By weight.

Production Example 14
Preparation of latex of carboxyl group-containing nitrile rubber (a1-10) Instead of N-methylolacrylamide as an amide group-containing monomer, except that 0.5 part of glycidyl methacrylate as an epoxy group-containing monomer was used In the same manner as in Production Example 13, a latex of carboxyl group-containing nitrile rubber (a1-10) was obtained. The composition of the resulting carboxyl group-containing nitrile rubber (a1-10) was composed of 62.5% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, 3% by weight of methacrylic acid units, and 0.5% by weight of glycidyl methacrylate units. Met.

Production Example 15
Manufacture of latex of carboxyl group-containing nitrile rubber (a1-11) The amount of 1,3-butadiene used was changed to 61 parts, and the amount of N-methylolacrylamide as an amide group-containing monomer was changed to 2.0 parts. Except for the above, a carboxyl group-containing nitrile rubber (a1-11) latex was obtained in the same manner as in Production Example 13. The composition of the obtained carboxyl group-containing nitrile rubber (a1-11) was composed of 61% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, 3% by weight of methacrylic acid units, and 2.0% by weight of N-methylolacrylamide units. Met.

Production Example 16
61 parts of the amount of production of 1,3-butadiene latex of the carboxyl group-containing nitrile rubber (A1-12), except for changing each 2.0 parts usage glycidyl methacrylate as the epoxy group-containing monomer In the same manner as in Production Example 13, a latex of carboxyl group-containing nitrile rubber (a1-12) was obtained. The composition of the resulting carboxyl group-containing nitrile rubber (a1-12) was 61% by weight of 1,3-butadiene units, 34% by weight of acrylonitrile units, 3% by weight of methacrylic acid units, and 2.0% by weight of glycidyl methacrylate units. It was.

Production Example 17
Production of latex of carboxyl group-containing styrene-butadiene rubber (a2-3) In a pressure-resistant vessel equipped with a stirrer, 50 parts of deionized water, 0.3 part of sodium dodecylbenzenesulfonate, 0.4 t-dodecyl mercaptan as a chain transfer agent Parts, 1.3-butadiene 62.5 parts, styrene 34 parts, methacrylic acid 3 parts, and amide group-containing monomer N-methylolacrylamide 0.5 parts were obtained to obtain a monomer emulsion. Separately, in a pressure-resistant polymerization reaction vessel equipped with a stirrer, 40 parts of deionized water, 0.2 part of sodium dodecylbenzenesulfonate, 0.35 part of sodium bicarbonate and 0.05 part of sodium ethylenediaminetetraacetate were charged and mixed. The temperature was raised to 70 ° C. And after adding 0.5 part of potassium persulfate to this, addition of the monomer emulsion obtained above was started immediately, and it added continuously over 5 hours, stirring and mixing. After the addition of the monomer emulsion, 0.2 part of potassium persulfate was added as a 3 wt% aqueous solution. When the polymerization conversion reached 90%, the temperature was raised to 85 ° C and the reaction was continued for another 3 hours. When the polymerization conversion rate was 95%, 0.1 part of sodium dimethyldithiocarbamate was added as a polymerization terminator to terminate the polymerization reaction. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing styrene-butadiene rubber (a2-3) was obtained. The resulting carboxyl group-containing styrene-butadiene rubber (a2-3) had a composition of 62.5% by weight of 1,3-butadiene units, 34% by weight of styrene units, 3% by weight of methacrylic acid units, 0 units of N-methylolacrylamide units. 0.5% by weight.

Production Example 18
Preparation of latex of carboxyl group-containing styrene-butadiene rubber (a2-4) Instead of N-methylolacrylamide as an amide group-containing monomer, 0.5 part of glycidyl methacrylate as an epoxy group-containing monomer was used. Except for the above, a carboxyl group-containing styrene-butadiene rubber (a2-4) latex was obtained in the same manner as in Production Example 17. The resulting carboxyl group-containing styrene-butadiene rubber (a2-4) had a composition of 62.5% by weight of 1,3-butadiene units, 34% by weight of styrene units, 3% by weight of methacrylic acid units, 0.5% of glycidyl methacrylate units. % By weight.

Production Example 19
In a pressure-resistant polymerization reaction vessel equipped with a latex stirrer of carboxyl group-containing butadiene rubber (a3-3), 96.5 parts of 1.3-butadiene, 3 parts of methacrylic acid, and N-methylolacrylamide as an amide group-containing monomer were added. 5 parts, 0.8 parts t-dodecyl mercaptan as chain transfer agent, 132 parts deionized water, 3 parts sodium dodecylbenzenesulfonate, 1 part sodium β-naphthalene sulfonate formalin condensate, 0.3 part potassium persulfate, Then, 0.005 part of sodium ethylenediaminetetraacetate was charged, and the polymerization temperature was maintained at 37 ° C. to initiate the polymerization. Then, when the polymerization conversion rate becomes 70%, the polymerization temperature is raised to 43 ° C., and the reaction is continued until the polymerization conversion rate becomes 95%. Thereafter, sodium dimethyldithiocarbamate 0% as a polymerization terminator is used. The polymerization reaction was stopped by adding 1 part. The unreacted monomer was distilled off from the copolymer latex under reduced pressure, and then the solid content concentration and pH were adjusted to obtain a carboxyl content having a solid content concentration of 40% by weight and pH 8.0. A latex of group-containing butadiene rubber (a3-3) was obtained. The composition of the obtained carboxyl group-containing butadiene rubber (a3-3) was 96.5% by weight of 1,3-butadiene units, 3% by weight of methacrylic acid units, and 0.5% by weight of N-methylolacrylamide units.

Production Example 20
Manufactured except that 0.5 part of glycidyl methacrylate as an epoxy group-containing monomer was used in place of N-methylolacrylamide as a latex amide group-containing monomer of carboxyl group-containing butadiene rubber (a3-4) In the same manner as in Example 19, a latex of carboxyl group-containing butadiene rubber (a3-4) was obtained. The composition of the obtained carboxyl group-containing butadiene rubber (a3-4) was 96.5% by weight of 1,3-butadiene units, 3% by weight of methacrylic acid units, and 0.5% by weight of glycidyl methacrylate units.

Example 1-1
Preparation of Latex Composition Deionized water was added to 250 parts of latex (100 parts in terms of carboxyl group-containing nitrile rubber (a1-1)) of carboxyl group-containing nitrile rubber (a1-1) obtained in Production Example 1. The solid concentration was adjusted to 35% by weight, and then 0.4 part of a sodium aluminate aqueous solution was added in terms of sodium aluminate. And after adjusting the pH of the said composition to 8.3 using potassium hydroxide, the latex composition was obtained by adjusting solid content concentration to 30 weight% by further adding deionized water. . The obtained latex composition was subjected to an operation for removing aggregates and the like in the latex composition by filtration as necessary (Examples 1-2 to 1-5, Comparative Example 1 described later). For 1-4, the operation for removing aggregates and the like was performed in the same manner as necessary.

Producing calcium nitrate, 13 parts of the dip molded product by mixing 0.05 parts of polyethylene glycol octylphenyl ether and water 87 parts of a nonionic emulsifier, and the aqueous coagulant solution was prepared. Next, a ceramic glove mold preliminarily heated to 70 ° C. is immersed in this aqueous coagulant solution for 5 seconds, pulled up, and dried at a temperature of 70 ° C. for 10 minutes to attach the coagulant to the glove mold. It was. Then, the glove mold with the coagulant attached is immersed in the latex composition obtained above for 10 seconds, pulled up, then immersed in warm water at 50 ° C. for 90 seconds to elute water-soluble impurities, A dip-molded layer was formed on the glove mold.
Next, the dip-molded layer-formed glove mold is heated at a temperature of 125 ° C. for 25 minutes to crosslink the dip-molded layer, and the crosslinked dip-molded layer is peeled off from the glove mold to form a dip-molded body (rubber gloves). Got. And about each of the obtained dip molding (rubber glove), tensile strength, elongation at break, and stress at the time of 500% elongation were measured. The results are shown in Table 1.

Example 1-2
Example 1-1, except that when preparing the latex composition, the amount of sodium aluminate aqueous solution added was changed to 0.2 parts in terms of sodium aluminate and the pH of the composition was adjusted to 8.5. A latex composition and a dip-formed product (rubber glove) were produced in the same manner as described above and evaluated in the same manner. The results are shown in Table 1.

Example 1-3
In preparing the latex composition, instead of the latex of the carboxyl group-containing nitrile rubber (a1-1) obtained in Production Example 1, the carboxyl group-containing nitrile rubber (a1-2) obtained in Production Example 2 was used. While using latex (100 parts in terms of carboxyl group-containing nitrile rubber (a1-2)), the amount of sodium aluminate aqueous solution added was 0.3 parts in terms of sodium aluminate, and the pH of the composition was 8.5. A latex composition and a dip-molded body (rubber glove) were produced in the same manner as in Example 1-1 except that the above was adjusted, and evaluated in the same manner. The results are shown in Table 1.

Example 1-4
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-1) latex obtained in Production Example 1, the carboxyl group-containing nitrile rubber (a1-3) obtained in Production Example 3 was used. A latex composition and dip were prepared in the same manner as in Example 1-2 except that latex (100 parts in terms of carboxyl group-containing nitrile rubber (a1-3)) was used and the pH of the composition was adjusted to 8.3. A molded body (rubber glove) was produced and evaluated in the same manner. The results are shown in Table 1.

Example 1-5
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-1) latex obtained in Production Example 1, the carboxyl group-containing nitrile rubber (a1-4) obtained in Production Example 4 was used. Except that latex (100 parts in terms of carboxyl group-containing nitrile rubber (a1-4)) was used and the pH of the composition was adjusted to 7.5, the latex composition and A dip-molded body (rubber glove) was produced and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 1-1
A latex composition and a dip-molded body (rubber gloves) were prepared in the same manner as in Example 1-1 except that when preparing the latex composition, the aqueous sodium aluminate solution was not added and the pH was adjusted to 8.4. Were manufactured and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 1-2
In preparing the latex composition, 1 part of sulfur (crosslinking agent), 0.5 part of zinc dibutyldithiocarbamate (vulcanization accelerator), and 1.2 parts of zinc oxide were used in place of the sodium aluminate aqueous solution. A latex composition and a dip-formed product (rubber glove) were produced in the same manner as in Example 1-1 except that the pH was adjusted to 8.5, and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 1-3
A latex composition and a dip-formed product (rubber gloves) were prepared in the same manner as in Example 1-1 except that 1.5 parts of zinc oxide was used instead of the sodium aluminate aqueous solution when preparing the latex composition. Were manufactured and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 1-4
A latex composition and a dip-molded body (rubber) were prepared in the same manner as in Example 1-1 except that the amount of the sodium aluminate aqueous solution was changed to 2.0 parts in terms of sodium aluminate when preparing the latex composition. Gloves) were manufactured and evaluated in the same manner. The results are shown in Table 1.

Evaluation of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-4 As shown in Table 1, latex containing carboxyl group-containing conjugated diene rubber (A) and a metal containing a trivalent or higher metal The content ratio of the metal compound (B) containing the compound (B) and containing a trivalent or higher metal is 0.1 to 1.5 with respect to 100 parts by weight of the carboxyl group-containing conjugated diene rubber (A). The dip-molded body (rubber glove) obtained by using the latex composition in parts by weight has a large tensile strength and elongation and a soft texture (less stress at 500% elongation). Examples 1-1 to 1-5).

On the other hand, when the metal compound (B) containing a trivalent or higher metal was not blended, the dip-molded body (rubber glove) was inferior in tensile strength (Comparative Example 1-1).
When sulfur was used in combination with a vulcanization accelerator and zinc oxide instead of the metal compound (B) containing a trivalent or higher metal, the elongation was small and the stress at the time of elongation was inferior to 500%. (Comparative Example 1-2). In Comparative Example 1-2, it is considered that the occurrence of delayed type allergy (Type IV) cannot be suppressed because it contains sulfur and a vulcanization accelerator.
Further, when zinc oxide was used alone instead of the metal compound (B) containing a trivalent or higher metal, the elongation was small and the stress at the time of 500% elongation was inferior (Comparative Example 1- 3).
Further, when the amount of the metal compound (B) containing a trivalent or higher metal was too large, the elongation was small and the stress at the time of 500% elongation was inferior (Comparative Example 1-4).

Example 2-1
250 parts latex of a carboxyl group-containing nitrile rubber obtained in Preparation Production Example 5 (a1-5) latex composition (carboxyl group-containing nitrile rubber (a1-5) 100 parts by equivalent), sodium aluminate 0.5 Part, 0.75 part of sorbitol and 0.75 part of sodium glycolate in water were added. And deionized water was added to this, and the latex composition was obtained by adjusting solid content concentration to 30 weight%.

Production of Dip Molded Body A coagulant aqueous solution was prepared by mixing 30 parts of calcium nitrate, 0.05 part of polyethylene glycol octylphenyl ether, which is a nonionic emulsifier, and 70 parts of water. Next, a ceramic glove mold preliminarily heated to 70 ° C. is immersed in this aqueous coagulant solution for 5 seconds, pulled up, and dried at a temperature of 70 ° C. for 10 minutes to attach the coagulant to the glove mold. It was. Then, the glove mold with the coagulant attached is immersed in the latex composition obtained above for 10 seconds, pulled up, then immersed in warm water at 50 ° C. for 90 seconds to elute water-soluble impurities, A dip-molded layer was formed on the glove mold.
Next, the dip-molded layer-formed glove mold is heated at a temperature of 125 ° C. for 25 minutes to crosslink the dip-molded layer, and the crosslinked dip-molded layer is peeled off from the glove mold to form a dip-molded body (rubber gloves). Got. And about the obtained dip molding (rubber glove), according to the said method, each measurement of tensile strength, elongation at break, stress at the time of 500% elongation, and stress retention was performed. The results are shown in Table 2.

Example 2-2
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-5) latex, 250 parts of the carboxyl group-containing styrene-butadiene rubber (a2-1) latex obtained in Production Example 6 (carboxyl A latex composition having a solid content concentration of 30% by weight and a dip-molded body (rubber gloves) except that a group-containing styrene-butadiene rubber (a2-1) 100 parts) was used. Were manufactured and evaluated in the same manner. The results are shown in Table 2.

Example 2-3
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-5) latex, 250 parts of the carboxyl group-containing butadiene rubber (a3-1) latex obtained in Production Example 7 (carboxyl group-containing) A latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber gloves) were produced in the same manner as in Example 2-1, except that 100 parts of butadiene rubber (a3-1) was used. Evaluation was performed in the same manner. The results are shown in Table 2.

Example 2-4
When preparing the latex composition, the solid content concentration was 30% by weight in the same manner as in Example 2-1, except that the blending amount of sorbitol was changed to 1.5 parts and sodium glycolate was not blended. A latex composition and a dip-molded body (rubber gloves) were produced and evaluated in the same manner. The results are shown in Table 2.

Example 2-5
When preparing the latex composition, the solid content concentration was 30% by weight in the same manner as in Example 2-1, except that the blending amount of sodium glycolate was changed to 1.5 parts and sorbitol was not blended. A latex composition and a dip-molded body (rubber gloves) were produced and evaluated in the same manner. The results are shown in Table 2.

Example 2-6
When preparing the latex composition, the amount of sodium aluminate was changed to 0.1 part, the amount of sorbitol was changed to 0.015 part, and the amount of sodium glycolate was changed to 0.015 part. In the same manner as in Example 2-1, a latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber glove) were produced and evaluated in the same manner. The results are shown in Table 2.

Example 2-7
When preparing the latex composition, the amount of sodium aluminate was changed to 0.1 part, the amount of sorbitol was changed to 0.5 part, and the amount of sodium glycolate was changed to 0.5 part, respectively. In the same manner as in Example 2-1, a latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber glove) were produced and evaluated in the same manner. The results are shown in Table 2.

Example 2-8
When preparing the latex composition, the amount of sodium aluminate was changed to 1 part, the amount of sorbitol was changed to 0.15 parts, and the amount of sodium glycolate was changed to 0.15 parts, respectively. In the same manner as in Example 2-1, a latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber glove) were produced and evaluated in the same manner. The results are shown in Table 2.

Example 2-9
Example 2 was prepared except that the amount of sodium aluminate was changed to 1 part, the amount of sorbitol was changed to 5 parts, and the amount of sodium glycolate was changed to 5 parts when preparing the latex composition. In the same manner as in Example 1, a latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber gloves) were produced and evaluated in the same manner. The results are shown in Table 2.

Comparative Example 2-1
A latex composition and a dip-molded body having a solid content of 30% by weight were prepared in the same manner as in Example 2-1, except that sodium aluminate, sorbitol and sodium glycolate were not blended when preparing the latex composition. (Rubber gloves) were manufactured and evaluated in the same manner. The results are shown in Table 2.

Comparative Example 2-2
A latex composition and a dip-molded body having a solid content concentration of 30% by weight were prepared in the same manner as in Example 2-2, except that sodium aluminate, sorbitol and sodium glycolate were not blended when preparing the latex composition. (Rubber gloves) were manufactured and evaluated in the same manner. The results are shown in Table 2.

Comparative Example 2-3
A latex composition having a solid content concentration of 30% by weight and a dip-molded article were prepared in the same manner as in Example 2-3, except that sodium aluminate, sorbitol and sodium glycolate were not blended when preparing the latex composition. (Rubber gloves) were manufactured and evaluated in the same manner. The results are shown in Table 2.

The following can be confirmed from Evaluation Table 2 of Examples 2-1 to 2-9 and Comparative Examples 2-1 to 2-3 .
That is, a latex composition obtained by blending a carboxyl group-containing conjugated diene rubber (A) latex with an alcoholic hydroxyl group-containing compound (C) in addition to a metal compound (B) containing a trivalent or higher metal. The dip-molded body (rubber glove) obtained by using such a latex composition is excellent in stability as a latex composition, has a large tensile strength and elongation, and has a soft texture (stress at 500% elongation). (Examples 2-1 to 2-9).

On the other hand, when it does not contain a metal compound (B) containing a trivalent or higher metal and an alcoholic hydroxyl group-containing compound (C), the resulting latex composition has a tensile strength when formed into a dip-molded body (rubber glove). As a result (Comparative Examples 2-1 to 2-3).

Example 3-1
250 parts latex of a carboxyl group-containing nitrile rubber obtained in Preparation Production Example 8 (a1-6) latex composition (carboxyl group-containing nitrile rubber (a1-6) 100 parts by equivalent), sodium aluminate 0.2 A mixed aqueous solution in which 0.4 part of sorbitol and 0.4 part of sodium glycolate were dissolved in water was added. And a deionized water and 5 weight% potassium hydroxide aqueous solution were added to this, and the latex composition was obtained by adjusting solid content concentration to 30 weight% and pH to 9.2.

Production of Dip Molded Body A coagulant aqueous solution was prepared by mixing 30 parts of calcium nitrate, 0.05 part of polyethylene glycol octylphenyl ether, which is a nonionic emulsifier, and 70 parts of water. Next, a ceramic glove mold preliminarily heated to 70 ° C. is immersed in this aqueous coagulant solution for 5 seconds, pulled up, and dried at a temperature of 70 ° C. for 10 minutes to attach the coagulant to the glove mold. It was. Then, the glove mold with the coagulant attached is immersed in the latex composition obtained above for 10 seconds, pulled up, then immersed in warm water at 50 ° C. for 90 seconds to elute water-soluble impurities, A dip-molded layer was formed on the glove mold.
Next, the dip-molded layer-formed glove mold is heated at a temperature of 125 ° C. for 25 minutes to crosslink the dip-molded layer, and the crosslinked dip-molded layer is peeled off from the glove mold to form a dip-molded body (rubber gloves) Got. And about the obtained dip molding (rubber glove), according to the said method, each measurement of tensile strength, elongation at break, stress at the time of 500% elongation, and stress retention was performed. The results are shown in Table 3.

Example 3-2
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing styrene-butadiene rubber (a2-2) latex obtained in Production Example 9 (carboxyl A latex composition having a solid content concentration of 30% by weight and a dip-molded body (rubber glove) in the same manner as in Example 3-1, except that a group-containing styrene-butadiene rubber (a2-2) 100 parts) was used. Were manufactured and evaluated in the same manner. The results are shown in Table 3.

Example 3-3
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing butadiene rubber (a3-2) latex obtained in Production Example 10 (carboxyl group-containing) Except that butadiene rubber (100 parts in terms of a3-2) was used, a latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber gloves) were produced in the same manner as in Example 3-1, Evaluation was performed in the same manner. The results are shown in Table 3.

Example 3-4
The amount of sodium aluminate is 0.2 to 0.5 parts, the amount of sorbitol is 0.4 to 0.75 parts, and the amount of sodium glycolate is 0.4 to 0.75 parts A latex composition and a dip-molded body (rubber glove) having a solid content concentration of 30% by weight were produced in the same manner as in Example 3-1, except that each was changed. The results are shown in Table 3.

Example 3-5
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing nitrile rubber (a1-5) latex obtained in Production Example 5 (carboxyl group-containing) A latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber gloves) were produced in the same manner as in Example 3-1, except that 100 parts of nitrile rubber (a1-5) was used. Evaluation was performed in the same manner. The results are shown in Table 3.

Example 3-6
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing styrene-butadiene rubber (a2-1) latex obtained in Production Example 6 (carboxyl) A latex composition having a solid content concentration of 30% by weight and a dip-molded article (rubber gloves) except that a group-containing styrene-butadiene rubber (a2-1) 100 parts) was used. Were manufactured and evaluated in the same manner. The results are shown in Table 3.

Example 3-7
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing butadiene rubber (a3-1) latex obtained in Production Example 7 (carboxyl group-containing) A latex composition having a solid content concentration of 30% by weight and a dip-molded body (rubber gloves) were produced in the same manner as in Example 3-1, except that 100 parts of butadiene rubber (a3-1) was used. Evaluation was performed in the same manner. The results are shown in Table 3.

Example 3-8
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing nitrile rubber (a1-7) latex obtained in Production Example 11 (carboxyl group-containing) A latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber gloves) were produced in the same manner as in Example 3-1, except that 100 parts of nitrile rubber (a1-7) was used. Evaluation was performed in the same manner. The results are shown in Table 3.

Example 3-9
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-6) latex, 250 parts of the carboxyl group-containing nitrile rubber (a1-8) latex obtained in Production Example 12 (carboxyl group-containing) A latex composition having a solid content concentration of 30% by weight and a dip-formed product (rubber gloves) were produced in the same manner as in Example 3-1, except that 100 parts of nitrile rubber (a1-8) was used. Evaluation was performed in the same manner. The results are shown in Table 3.

From Evaluation Table 3 of Examples 3-1 to 3-9 , the following can be confirmed.
That is, the carboxyl group-containing conjugated diene rubber obtained by emulsion polymerization at 0 to 25 ° C. by comparing Examples 3-1 to 3-4 and Examples 3-5 to 3-7 By using (A), it is possible to further improve the tensile strength as compared with the case of using carboxyl group-containing conjugated diene rubber (A) obtained by emulsion polymerization at 37 ° C. to 70 ° C. It can be confirmed that there is. In particular, the results shown in Table 3 indicate that by using the carboxyl group-containing conjugated diene rubber (A) obtained by emulsion polymerization at 0 to 25 ° C., the elongation is large and the soft texture (at 500% elongation) It is confirmed that the tensile strength can be further improved while keeping the stress of the
Further, by comparing Examples 3-5, 3-8, and 3-9, the amount of chain transfer agent used was in the range of 0.15 to 0.95 parts by weight with respect to 100 parts by weight of the monomer mixture. It can be said that the tensile strength, the elongation, and the soft texture (the stress at the time of 500% elongation is small) can be appropriately adjusted within a suitable range.

Example 4-1
250 parts latex of a carboxyl group-containing nitrile rubber obtained in Preparation Production Example 13 (A1-9) latex composition (carboxyl group-containing nitrile rubber (A1-9) 100 parts by equivalent), sodium aluminate 0.2 A mixed aqueous solution in which 0.4 part of sorbitol and 0.4 part of sodium glycolate were dissolved in water was added. And the deionized water and 5% potassium hydroxide aqueous solution were added to this, and the latex composition was obtained by adjusting solid content concentration to 30 weight% and pH9.2.

Producing calcium nitrate, 30 parts of the dip-molded product, by mixing 0.05 parts of polyethylene glycol octylphenyl ether and 70 parts of water are nonionic emulsifiers, and the aqueous coagulant solution was prepared. Next, a ceramic glove mold preliminarily heated to 70 ° C. is immersed in this aqueous coagulant solution for 5 seconds, pulled up, and dried at a temperature of 70 ° C. for 10 minutes to attach the coagulant to the glove mold. It was. Then, the glove mold with the coagulant attached is immersed in the latex composition obtained above for 10 seconds, pulled up, then immersed in warm water at 50 ° C. for 90 seconds to elute water-soluble impurities, A dip-molded layer was formed on the glove mold.
Next, the dip-molded layer-formed glove mold is heated at a temperature of 125 ° C. for 25 minutes to crosslink the dip-molded layer, and the crosslinked dip-molded layer is peeled off from the glove mold to form a dip-molded body (rubber glove). Got. And about the obtained dip molding (rubber glove), according to the said method, each measurement of tensile strength, elongation at break, stress at the time of 500% elongation, and stress retention was performed. The results are shown in Table 4.

Example 4-2
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing nitrile rubber (a1-10) latex obtained in Production Example 14 (carboxyl group-containing) A latex composition and a dip-formed product (rubber glove) were produced in the same manner as in Example 4-1, except that 100 parts of nitrile rubber (a1-10) was used, and evaluated in the same manner. The results are shown in Table 4.

Example 4-3
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing nitrile rubber (a1-11) latex obtained in Production Example 15 (carboxyl group-containing) A latex composition and a dip-molded body (rubber glove) were produced in the same manner as in Example 4-1, except that 100 parts of nitrile rubber (a1-11) was used, and evaluated in the same manner. The results are shown in Table 4.

Example 4-4
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing nitrile rubber (a1-12) latex obtained in Production Example 16 (carboxyl group-containing) A latex composition and a dip-formed product (rubber glove) were produced in the same manner as in Example 4-1, except that 100 parts of nitrile rubber (a1-12) was used, and evaluated in the same manner. The results are shown in Table 4.

Example 4-5
When preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing styrene-butadiene rubber (a2-3) latex obtained in Production Example 17 (carboxyl) A latex composition and a dip-molded body (rubber glove) were produced in the same manner as in Example 4-1, except that the group-containing styrene-butadiene rubber (100 parts in terms of a2-3) was used. went. The results are shown in Table 4.

Example 4-6
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing styrene-butadiene rubber (a2-4) latex obtained in Production Example 18 (carboxyl) A latex composition and a dip-molded body (rubber glove) were produced in the same manner as in Example 4-1, except that the group-containing styrene-butadiene rubber (100 parts in terms of a2-4) was used. went. The results are shown in Table 4.

Example 4-7
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing butadiene rubber (a3-3) latex obtained in Production Example 19 (carboxyl group-containing) A latex composition and a dip-molded body (rubber glove) were produced in the same manner as in Example 4-1, except that butadiene rubber (100 parts in terms of a3-3) was used, and evaluated in the same manner. The results are shown in Table 4.

Example 4-8
In preparing the latex composition, instead of the carboxyl group-containing nitrile rubber (a1-9) latex, 250 parts of the carboxyl group-containing butadiene rubber (a3-4) latex obtained in Production Example 20 (carboxyl group-containing) A latex composition and a dip-formed product (rubber gloves) were produced in the same manner as in Example 4-1, except that butadiene rubber (100 parts in terms of a3-4) was used, and evaluated in the same manner. The results are shown in Table 4.

Comparative Example 4-1
A latex composition and a dip-formed product (rubber gloves) were produced in the same manner as in Example 4-1, except that sodium aluminate, sorbitol and sodium glycolate were not blended when preparing the latex composition. Evaluation was performed in the same manner. The results are shown in Table 4.

Comparative Example 4-2
A latex composition and a dip-formed product (rubber gloves) were produced in the same manner as in Example 4-2, except that sodium aluminate, sorbitol and sodium glycolate were not blended when preparing the latex composition. Evaluation was performed in the same manner. The results are shown in Table 4.

The following can be confirmed from Evaluation Table 4 of Examples 4-1 to 4-8 and Comparative Examples 4-1 and 4-2 .
That is, as the carboxyl group-containing conjugated diene rubber (A) constituting the latex of the carboxyl group-containing conjugated diene rubber (A), one containing an amide group-containing monomer unit or an epoxy group-containing monomer unit was used. In this case, the obtained dip-molded body (rubber glove) can have a higher stress retention (Examples 4-1 to 4-8). In particular, from the results of Table 4, when using a carboxyl group-containing conjugated diene rubber (A) containing an amide group-containing monomer unit or an epoxy group-containing monomer unit, the tensile strength is high, It can be confirmed that the stress retention rate can be further improved while maintaining a large texture and a soft texture (less stress at 500% elongation).

On the other hand, even when a carboxyl group-containing conjugated diene rubber (A) containing an amide group-containing monomer unit or an epoxy group-containing monomer unit is used, a metal compound (B) containing a trivalent or higher metal. When the alcoholic hydroxyl group-containing compound (C) was not contained, the obtained dip-molded body (rubber glove) was inferior in tensile strength and stress retention (Comparative Examples 4-1 and 4-2).

Claims

A latex composition comprising a latex of a carboxyl group-containing conjugated diene rubber (A) and a metal compound (B) containing a trivalent or higher metal,
A latex composition in which the content ratio of the metal compound is 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the carboxyl group-containing conjugated diene rubber (A).
The latex composition according to claim 1, wherein the metal compound (B) is an aluminum compound.
The at least 1 sort (s) of alcoholic hydroxyl group containing compound (C) selected from saccharide | sugar (c1), sugar alcohol (c2), a hydroxy acid (c3), and a hydroxy acid salt (c4) is further contained. Latex composition.
The content of the metal compound (B) and the content of the alcoholic hydroxyl group-containing compound (C) are 1: 0 by weight ratio of “metal compound (B): alcoholic hydroxyl group-containing compound (C)”. The latex composition according to claim 3, wherein the latex composition is 1 to 1:50.
The latex composition according to claim 3 or 4, wherein the alcoholic hydroxyl group-containing compound (C) is at least one selected from sugar alcohol (c2) and hydroxy acid salt (c4).
The carboxyl group-containing conjugated diene rubber (A) comprises 56 to 78% by weight of a conjugated diene monomer unit, 20 to 40% by weight of an ethylenically unsaturated nitrile monomer unit, and an ethylenically unsaturated carboxylic acid monomer. 6. The latex composition according to claim 1, which is a carboxyl group-containing nitrile rubber (a1) containing 2 to 6.5% by weight of units.
The carboxyl group-containing conjugated diene rubber (A) is selected from a conjugated diene monomer unit, an ethylenically unsaturated carboxylic acid monomer unit, an amide group-containing monomer unit, and an epoxy group-containing monomer unit. The latex composition according to any one of claims 1 to 5, comprising at least one monomer unit.
The latex composition according to claim 7, wherein the monomer constituting at least one monomer unit selected from the amide group-containing monomer unit and the epoxy group-containing monomer unit is (meth) acrylamide.
The monomer constituting at least one monomer unit selected from the amide group-containing monomer unit and the epoxy group-containing monomer unit is an epoxy group-containing (meth) acrylate. Latex composition.
A method for producing a latex composition comprising a latex of a carboxyl group-containing conjugated diene rubber (A) and a metal compound (B) containing a trivalent or higher metal,
A monomer mixture containing at least a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer is subjected to emulsion polymerization at 0 to 25 ° C., whereby the latex of the carboxyl group-containing conjugated diene rubber (A) is obtained. A first step to obtain;
A method for producing a latex composition, comprising: a second step of blending the metal compound (B) with the latex of the carboxyl group-containing conjugated diene rubber (A).
A method for producing a latex composition comprising a latex of a carboxyl group-containing conjugated diene rubber (A) and a metal compound (B) containing a trivalent or higher metal,
The presence of 0.15 to 0.95 parts by weight of a chain transfer agent in a monomer mixture containing at least a conjugated diene monomer and an ethylenically unsaturated carboxylic acid monomer with respect to 100 parts by weight of the monomer mixture A first step of obtaining a latex of the carboxyl group-containing conjugated diene rubber (A) by emulsion polymerization under;
A method for producing a latex composition, comprising: a second step of blending the metal compound (B) with the latex of the carboxyl group-containing conjugated diene rubber (A).
In the second step, in addition to the metal compound (B), a saccharide (c1), a sugar alcohol (c2), a hydroxy acid (c3) and a hydroxy group are added to the latex of the carboxyl group-containing conjugated diene rubber (A). The method for producing a latex composition according to claim 10 or 12, wherein at least one alcoholic hydroxyl group-containing compound (C) selected from acid salts (c4) is further blended.
A method for producing a dip-molded product, comprising a step of dip-molding the latex composition according to any one of claims 1 to 9 or the latex composition obtained by the production method according to any one of claims 10 to 12.
A film molded article comprising the latex composition according to any one of claims 1 to 9.