KR101603378B1 - Latex and composition for dipforming lightweight dipformed article and method for preparing them - Google Patents

Abstract

The present invention relates to a latex for deep molding, a composition for dip molding, a lightweight dip molded article and a manufacturing method thereof. According to the present invention, it is possible to solve the problem of lowering of physical properties appearing in a thin lightweight glove and to provide a latex for deep molding with high tensile strength There is provided an effect of providing a composition for deep molding capable of producing dip-shaped articles and the like, which can be applied in a field of demand, and a method of producing a lightweight dip-molded article using the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a latex for dip molding, a composition for dip molding, a lightweight dip molded article,

The present invention relates to a latex for dip molding, a composition for dip molding, a lightweight dip molded article, and a method of manufacturing the same, and more particularly, to a method of producing a lightweight dip molded article by dispersing an ethylenically unsaturated acid monomer in a multilayer latex, And a lightweight dip molded product using the latex and a composition and a method of manufacturing the same.

With the increasing demand for gloves used globally for medical inspections and airport and vesicle inspections, there has been a problem in PVC and natural rubber, which are the main raw materials used for such purposes, and a new raw material, acrylonitrile-butadiene The market for latex latex is growing rapidly.

PVC gloves are manufactured by mixing PVC plastisol with DOP as a plasticizer. Due to environmental problems, production and demand are gradually decreased and a new substitute is needed. In case of natural rubber, it causes skin allergy caused by protein, And the use thereof is severely restricted, especially in hospitals and restaurants.

When the gloves are manufactured using acrylonitrile-butadiene-based latex, the market is rapidly expanding because of solving the environmental problems and skin allergy problems caused by the above materials. However, The speed of the manufacturing process is accelerated, and the production of thin lightweight gloves having a thickness of 0.07 mm or less is becoming common. When a thin lightweight glove is produced, the basic glove properties, particularly tensile strength, are deteriorated.

In order to solve the problems of the prior art as described above, the present invention relates to a latex for deep-forming which is capable of producing a deep-formed product having excellent basic properties such as tensile strength when a lightweight product is produced by distributing an ethylenically unsaturated acid monomer in a multi- And a method for producing a dip-molded article using the same.

In order to achieve the above object, the present invention provides a thermoplastic resin composition comprising a conjugated diene monomer, an ethylenically unsaturated nitrile monomer and an ethylenically unsaturated acid monomer in an amount of more than 50 parts by weight in 100 parts by weight of the total monomers constituting the seed and the shell layer And a shell layer comprising the seed and a conjugated diene monomer and an ethylenically unsaturated nitrile monomer in an amount of less than 50 parts by weight based on 100 parts by weight of the total monomers constituting the seed and the shell layer, And a method of producing the latex.

The present invention also provides a composition for dip molding comprising the multi-layer latex and a process for producing the same.

The present invention also provides a lightweight dipped molded article made from the composition for dip molding and a method for producing the same.

Hereinafter, the present invention will be described in detail.

First, in the present invention, as the latex for dip molding, the conjugated diene monomer, the ethylenically unsaturated nitrile monomer and the ethylenic unsaturated acid monomer are contained in an amount exceeding 50 parts by weight in 100 parts by weight of the total monomers constituting the seed and the shell layer And a shell layer comprising the seed and a conjugated diene monomer and an ethylenically unsaturated nitrile monomer in an amount of less than 50 parts by weight based on 100 parts by weight of the total monomers constituting the seed and the shell layer, ≪ / RTI > has a technical feature.

Wherein the multi-layer latex comprises 60 to 90 parts by weight or 66 to 85 parts by weight of 100 parts by weight of the total monomers constituting the seed and the shell layer, and a seed comprising the seed and the shell layer 40 to 10 parts by weight, or 15 to 34 parts by weight, based on 100 parts by weight of the total monomers, , And a shell layer comprising, as a component thereof, a shell layer.

As a specific example, the total monomer constituting the seed and shell layer may be composed of 55 to 75% by weight of a conjugated diene monomer, 15 to 35% by weight of an ethylenically unsaturated nitrile monomer, and 1 to 10% by weight of an ethylenically unsaturated acid monomer have.

As another example, the total monomer constituting the seed and shell layer may be composed of 60 to 72% by weight of a conjugated diene monomer, 22 to 34% by weight of an ethylenically unsaturated nitrile monomer, and 3 to 8% by weight of an ethylenically unsaturated acid monomer have.

As a specific example, the latex may be prepared by adding a conjugated diene monomer, an ethylenically unsaturated nitrile monomer, or an ethylenically unsaturated acid monomer, and if necessary, other monomers copolymerizable with the monomers, emulsifiers, polymerization initiators, chain transfer agents, And at least one member selected from the group consisting of the following:

The conjugated diene monomer, the ethylenically unsaturated nitrile monomer, the ethylenic unsaturated acid monomer, and other monomers copolymerizable with these monomers, if necessary, emulsifier, polymerization initiator, chain transfer agent and other additives are not particularly limited, Can be used, but specific examples will be described below.

The conjugated diene-based monomer is at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and isoprene But are not limited thereto. When the amount of the conjugated diene monomer is less than 55 parts by weight, the polymerized copolymer may be hardened. When the amount of the conjugated diene monomer is more than 75 parts by weight, the rigidity may be deteriorated.

The ethylenically unsaturated nitrile monomer may be at least one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile,? -Chloronitrile and? -Cyanoethyl acrylonitrile, but is not limited thereto Do not. The ethylenically unsaturated nitrile monomer has a function of imparting suitable hardness and chemical resistance to the polymerized copolymer. When the amount is less than 15 parts by weight, sufficient hardness and chemical resistance can not be exhibited. When the amount is more than 35 parts by weight, .

The ethylenic unsaturated acid monomer is an ethylenically unsaturated monomer containing an acidic group such as a carboxyl group, a sulfonic acid group, or an acid anhydride group, and examples thereof include ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, ; Polycarboxylic anhydrides such as maleic anhydride and citraconic anhydride; Ethylenically unsaturated sulfonic acid monomers such as styrenesulfonic acid; At least one of ethylenically unsaturated polycarboxylic acid partial ester monomers such as monobutyl fumarate, monobutyl maleate, and mono-2-hydroxypropyl maleate may be used.

The ethylenic unsaturated acid monomer improves the polymerization stability and conversion of the polymerized copolymer and improves the tensile strength. When the amount of the ethylenic unsaturated acid monomer is less than 1 part by weight, an improvement effect can not be expected. When the amount of the ethylenic unsaturated acid monomer exceeds 10 parts by weight There is a problem in flexibility and the like.

Other monomers copolymerizable with these monomers, if necessary, include fluoroalkyl vinyl ethers such as fluoroethyl vinyl ether; (Meth) acrylamide, N, N-dimethylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide and N-propoxymethyl An ethylenically unsaturated amide monomer selected from the group consisting of: Non-conjugated diene monomers such as vinylpyridine, vinylnorbornene, dicyclopentadiene and 1,4-hexadiene; (Meth) acrylate, tetrafluoropropyl (meth) acrylate, dibutyl maleate, di (meth) acrylate, di (meth) acrylate, Butyl methacrylate, diethyl maleate, methoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, cyanomethyl (meth) acrylate, (Meth) acrylate, 2-ethyl-6-cyanohexyl (meth) acrylate, 3-cyanopropyl (meth) acrylate, hydroxymethyl (meth) acrylate, An ethylenically unsaturated carboxylic acid ester monomer selected from the group consisting of (meth) acrylic acid hydroxypropyl, glycidyl (meth) acrylate, and dimethylaminoethyl (meth) acrylate; One or more of these may be used, but the present invention is not limited thereto.

The emulsifier is added during the polymerization reaction and after the reaction to impart stability to the latex, and various kinds of anionic emulsifiers and nonionic emulsifiers can be used. Examples of the anionic emulsifier include alkylbenzenesulfonates, alcohol sulfates, alcohol ether sulfonates, alkylphenol ether sulfonates, alpha olefin sulfonates, paraffin sulfonates, ester sulfosuccinates, phosphate esters and the like. Include alkylphenol ethoxylate, phthiamine ethoxylate, fatty acid ethoxylate, alkanoamide and the like. These emulsifiers may be used singly or in combination of two or more, and the amount thereof is 0.5 to 10 parts by weight based on 100 parts by weight of the total monomers.

Examples of the polymerization initiator include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium persulfate, and hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p-menthol hydroperoxide, di-t-butyl peroxide, t-butyl cumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide Organic peroxides such as oxides, 3,5,5-trimethylhexanol peroxide, t-butyl peroxyisobutyrate; Azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and azobisisobutyric acid (butyl acid) methyl. As a specific example, inorganic or organic peroxides or persulfates may be used among the radical initiators. The amount of the polymerization initiator may be 0.01 to 2 parts by weight, or 0.02 to 1.5 parts by weight based on 100 parts by weight of the total monomers.

The chain transfer agent is used to control the molecular weight, gel content, and gel structure of the acrylonitrile-butadiene-based copolymer. Examples of the chain transfer agent include mercaptans such as? -Methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, and octyl mercaptan; Halogenated hydrocarbons such as carbon tetrachloride, methylene chloride, and methylene bromide; At least one of sulfur-containing compounds such as tetraethylthiuram disulfide, dipentamethylenethiuram disulfide, and diisopropylkisantigen disulfide can be used. The chain transfer agent may be used in an amount of 0.1 to 5 parts by weight, 0.2 to 2.0 parts by weight, or 0.3 to 1.0 part by weight based on 100 parts by weight of the total monomers, though it varies depending on the kind thereof.

As other additives, at least one selected from the group consisting of sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrophosphate and sodium sulfite may be used.

The latex may be prepared in two steps or in multiple stages. Generally, seed latex is prepared and then polymerized by coating one to three layers of the shell. The polymerization conditions may be those used in conventional emulsion polymerization methods.

As a specific example, the ethylenic unsaturated acid monomer of the above composition range and a part of the mixture of the other monomers are added to prepare a seed, and then the remaining monomers except for the ethylenic unsaturated acid monomer are added to prepare an emulsion polymerization system . The polymerization temperature is, for example, 10 to 90 ° C, or 25 to 75 ° C.

And the glass transition temperature of the seed is -35 캜 or higher. The monomers charged after seed preparation are polymerized into a polymeric shell layer surrounding the seed, and the polymeric shell layer has a glass transition temperature of -60 캜 or less.

At this time, the total amount of the ethylenically unsaturated acid monomer in the composition range is put into production of the seed, and the monomer to be added after the seed production is not present in the ethylenic unsaturated acid monomer.

Examples of the polymerization terminator include hydroxylamine, hydroxyamine sulphate, diethylhydroxyamine, hydroxyamine sulphonic acid and its alkali metal ion, sodium dimethyldithiocarbamate, And aromatic hydroxyditricarboxylic acids such as hydroquinone dicarboxylic acid, mate, hydroquinone derivatives, hydroxydiethylbenzenedithiocarboxylic acid, and hydroxy dibutylbenzenedithiocarboxylic acid. The amount of the polymerization terminator to be used is not particularly limited, but is 0.1 to 2 parts by weight based on 100 parts by weight of the monomer

The multi-layer latex may include 80 to 99% by weight, 90 to 99% by weight or 94 to 97% by weight in the composition for dip molding.

In the latex polymerization of the present invention, a pigment such as titanium oxide, a filler such as silica, a thickener, a chelating agent, a dispersant, a pH adjuster, an oxygen scavenger, a particle size regulator, an aging inhibitor, and an oxygen scavenger may be used . In some cases, the polymerization reaction may be terminated, the unreacted monomers may be removed, and the solids content or pH may be adjusted to obtain the latex resin of the present invention. Furthermore, the obtained multi-layer latex of the seed-shell layer type can be adjusted to pH 7 to 9, or pH 7.5 to 8.5.

Concretely, in the group consisting of a vulcanizing agent, a vulcanization accelerator, an ionic crosslinking agent, a pigment such as titanium oxide, a filler such as silica, and a thickener at 80 to 99% by weight, 90 to 99% by weight or 94 to 97% by weight of the multilayer latex From 20 to 1% by weight, from 10 to 1% by weight, or from 3 to 6% by weight, based on the total weight of the composition.

The vulcanizing agent is usually used for dip molding, and for example, sulfur such as powdery sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur is preferable. The amount of the vulcanizing agent to be used is 0.1 to 10 parts by weight, or 1 to 5 parts by weight, based on 100 parts by weight of the solid latex.

Examples of the vulcanization accelerator include those commonly used for dip molding, such as 2-mercaptobenzothiazole, 2,2-dithiobisbezothiozolo-2 (2-mercaptobenzothiazole) 2-sulfonamide, N-cyclohexylbenzothiazole-2-sulfenamide, 2-morpholinothiobenzothiazole, tetramethylthiuram monosulfide ), Tetramethylthiuram disulfide, Zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, Diphenylguanidine, di-ols-Toliguanidine (Di-o-tolyguanidine). The amount of the vulcanization accelerator to be used is 0.1 to 10 parts by weight, or 0.5 to 5 parts by weight, based on 100 parts by weight of the solid latex. The amount of zinc oxide to be used is 0.1 to 5 parts by weight, or 0.5 to 2 parts by weight, based on 100 parts by weight of the solid latex.

The composition for dip molding may further contain a pigment, a thickener, a chelating agent, a dispersant, an oxygen scavenger, a particle size regulator, an antioxidant, an oxygen scavenger, etc., if necessary.

The composition for dip molding may further include adjusting pH to 8 to 12, pH 9 to 11, or pH 9.3 to 10.5 using a pH adjusting agent such as ammonia or alkali hydroxide.

The solid content concentration of the composition for dip molding other than water may be 5 to 35% by weight (moisture content 65 to 95%), for example 8 to 30% by weight or 10 to 25% by weight . For example, water may be added to adjust the solid concentration.

Further, the lightweight dip-molded article of the present invention is characterized by being obtained by dip-molding the composition.

The dip molding method is not particularly limited and may be a method commonly used in the art. Specific examples thereof include a direct dipping method, an anode adhesion dipping method, and a Teague adhesion dipping method. Of these, it is preferable to use a deposition dipping method. In this case, a dip-shaped article having a uniform thickness can be easily obtained.

A method of producing a lightweight dip molded article of the present invention comprises the steps of: a) applying a coagulant solution to a mold and drying; b) applying a composition for dip molding to a mold to which a coagulant is applied to form a dip molding layer; c) crosslinking said dip molding layer; And d) peeling the crosslinked dip molding layer from the mold to obtain a dip molded article.

The production method of the lightweight dip-molded product will be described in detail as follows. First, a hand shaped dip forming die is immersed in a coagulating agent solution, and a coagulant is attached to the surface of the dipping forming die.

Examples of coagulants include metal halides such as barium chloride, calcium chloride, magnesium chloride, zinc chloride, aluminum chloride, and the like; Nitrates such as barium nitrate, calcium nitrate and zinc nitrate; Acetic acid salts such as barium acetate, calcium acetate and zinc acetate; Calcium sulfate, magnesium sulfate, and sulfate such as aluminum sulfate. Of these, calcium chloride and calcium nitrate are preferred.

The coagulant solution is a solution in which the above coagulant is dissolved in water, alcohol or a mixture thereof. The concentration of the coagulant in the coagulant solution may be, for example, 5 to 45% by weight, and still another example is 8 to 35% by weight or 10 to 25% by weight.

Then, a dip molding die with the coagulant attached thereto is immersed in the dip molding composition of the present invention, and a dip molding die is taken out to form a dip molding die in a dip molding die. Subsequently, the latex is crosslinked by heat-treating the dip molding layer formed in the dip forming mold. During the heat treatment, the water component first evaporates and vulcanization is carried out through crosslinking. Subsequently, the dip-formed layer crosslinked by the heat treatment is peeled off from the dip forming mold to obtain a dipped molded article. The obtained dip-molded article corresponds to a thin light-weight molded article having a thickness of the dip-molded article of 0.07 mm or less.

The process according to the invention can also be used for any latex article which can be prepared by the well known dip molding process. Specifically, it can be applied lightly to deep-formed latex articles selected from surgical gloves, examination gloves, condoms, catheters or various healthcare products such as industrial and household gloves.

As described above, the latex and composition for deep molding capable of producing a dip molded article having excellent basic properties such as tensile strength and the like by producing an ethylenic unsaturated acid monomer in a multi-layered latex, and a lightweight dip- And a manufacturing method thereof.

Hereinafter, the present invention will be described in detail with reference to the following examples, but the scope of the present invention is not limited to these examples.

Example  One

(Production of latex for deep molding)

A 10 L pressure reactor equipped with a stirrer, a thermometer, a condenser and an inlet of nitrogen gas and equipped with a monomer, an emulsifier and a polymerization initiator was charged with 27 parts by weight of acrylonitrile, 52 parts by weight of methacrylic acid, 6 parts by weight of methacrylic acid (corresponding to 85 parts by weight of total monomer), 3.0 parts by weight of sodium dodecylbenzenesulfonate, 1 part by weight of sodium naphthalate, 0.5 parts by weight of ethylene oxide- 0.9 part by weight of mercaptan and 200 parts by weight of ion-exchanged water were charged, and then the temperature was raised to 40 占 폚. 0.5 part by weight of calcium persulfate as a polymerization initiator was added thereto, followed by stirring for about 480 minutes to prepare a seed.

2 parts by weight of acrylonitrile, 13 parts by weight of butadiene (corresponding to 15 parts by weight of the total monomers), 0.5 part by weight of sodium dodecylbenzenesulfonate and 50 parts by weight of ion-exchanged water were mixed and stirred to prepare a pre-emulsion.

After the preemulsion was charged into the reactor, the temperature was raised to 60 ° C to allow the polymerization to proceed. When the conversion was 94%, 0.3 part by weight of ammonium hydroxide was added to terminate the polymerization. Unreacted monomers were removed by deodorization process and ammonia water, antioxidants, antifoaming agents and the like were added to prepare an acrylonitrile-butadiene latex having a solid concentration of 44.5% and a pH of 8.0.

(Preparation of composition for dip molding)

1.5 parts by weight of sulfur, 1.5 parts by weight of zinc oxide, 0.5 part by weight of zinc dibutyldithiocarbamate and a 3% potassium hydroxide solution and an appropriate amount of secondary distilled water were added to 100 parts by weight of the latex to obtain a dip having a solid concentration of 25% To obtain a molding composition.

(Dip molded article production)

12 parts by weight of calcium nitrate, 79.5 parts by weight of water, 8 parts by weight of calcium carbonate and 0.5 part by weight of wetting agent (Teric 320 produced by Huntsman Corporation, Australia) were mixed to prepare a coagulant solution. A hand-shaped ceramic mold was immersed in this solution for 1 minute, taken out, dried at 70 ° C for 3 minutes, and the coagulant was applied to the hand mold.

Next, the mold to which the coagulant was applied was immersed in the composition for deep molding for 15 seconds, pulled up, dried at 70 DEG C for 1 minute, and immersed in water or hot water for 3 minutes. The mold was again dried at 70 DEG C for 3 minutes and then crosslinked at 125 DEG C for 20 minutes. The crosslinked dip-formed layer was peeled off from the hand-shaped mold to prepare a glove-shaped dip-molded article, and the physical properties thereof are shown in Table 1 below.

Example  2

A 10 L pressure reactor equipped with a stirrer, a thermometer, a condenser and an inlet of nitrogen gas and equipped with a monomer, an emulsifier and a polymerization initiator was charged with 32 parts by weight of acrylonitrile, 47 parts by weight of methacrylic acid, 6 parts by weight of methacrylic acid (corresponding to 85 parts by weight of total monomer), 3.0 parts by weight of sodium dodecylbenzenesulfonate, 1 part by weight of sodium naphthalate, 0.5 part by weight of ethylene oxide- 0.9 part by weight of mercaptan and 200 parts by weight of ion-exchanged water were charged, and then the temperature was raised to 40 占 폚. 0.5 part by weight of calcium persulfate as a polymerization initiator was added thereto, followed by stirring for about 480 minutes to prepare a seed.

2 parts by weight of acrylonitrile, 13 parts by weight of butadiene (corresponding to 15 parts by weight of the total monomers), 0.5 part by weight of sodium dodecylbenzenesulfonate and 50 parts by weight of ion-exchanged water were mixed and stirred to prepare a pre-emulsion. After the preemulsion was charged into the reactor, the temperature was raised to 60 ° C to allow the polymerization to proceed. When the conversion was 94%, 0.3 part by weight of ammonium hydroxide was added to terminate the polymerization. Unreacted monomers were removed by deodorization process and ammonia water, antioxidants, antifoaming agents and the like were added to prepare an acrylonitrile-butadiene latex having a solid concentration of 44.5% and a pH of 8.0. Thereafter, a composition for dip molding and a dip-molded article were prepared in the same manner as in Example 1 to prepare a glove-shaped dip-molded article, and physical properties thereof are shown in Table 1 below.

Example  3

A 10 L pressure reactor equipped with a stirrer, a thermometer, a condenser and an inlet of nitrogen gas, equipped with a monomer, an emulsifier and a polymerization initiator, was charged with 20 parts by weight of acrylonitrile, 40 parts by weight of methacrylic acid, 6 parts by weight of methacrylic acid (corresponding to 66 parts by weight of total monomer), 3.0 parts by weight of sodium dodecylbenzenesulfonate, 1 part by weight of sodium naphthalate, 0.5 part by weight of ethylene oxide-based sulfonate, 0.9 part by weight of mercaptan and 200 parts by weight of ion-exchanged water were charged, and then the temperature was raised to 40 占 폚. 0.5 part by weight of calcium persulfate as a polymerization initiator was added thereto, followed by stirring for about 360 minutes to prepare a seed.

2 parts by weight of acrylonitrile, 32 parts by weight of butadiene (corresponding to 34 parts by weight of the total monomer), 0.5 part by weight of sodium dodecylbenzenesulfonate and 50 parts by weight of ion-exchanged water were mixed and stirred to prepare a pre-emulsion. After the preemulsion was charged into the reactor, the temperature was raised to 60 ° C to allow the polymerization to proceed. When the conversion was 94%, 0.3 part by weight of ammonium hydroxide was added to terminate the polymerization. Unreacted monomers were removed by deodorization process and ammonia water, antioxidants, antifoaming agents and the like were added to prepare an acrylonitrile-butadiene latex having a solid concentration of 44.5% and a pH of 8.0. Thereafter, a composition for dip molding and a dip-molded article were prepared in the same manner as in Example 1 to prepare a glove-shaped dip-molded article, and physical properties thereof are shown in Table 1 below.

Comparative Example  One

A 10 L pressure reactor equipped with a stirrer, a thermometer, a condenser and an inlet of nitrogen gas and equipped with a monomer, an emulsifier and a polymerization initiator was charged with 27 parts by weight of acrylonitrile, 52 parts by weight of methacrylic acid, 4 parts by weight of methacrylic acid (corresponding to 83 parts by weight of total monomer), 3.0 parts by weight of sodium dodecylbenzenesulfonate, 1 part by weight of sodium naphthalate, 0.5 parts by weight of ethylene oxide- 0.9 part by weight of mercaptan and 200 parts by weight of ion-exchanged water were charged, and then the temperature was raised to 40 占 폚. 0.5 part by weight of calcium persulfate as a polymerization initiator was added thereto, followed by stirring for about 480 minutes to prepare a seed.

2 parts by weight of acrylonitrile, 13 parts by weight of butadiene, 2 parts by weight (corresponding to 17 parts by weight of total monomer) of methacrylic acid, 0.5 part by weight of sodium dodecylbenzenesulfonate and 50 parts by weight of ion-exchanged water were mixed and stirred To prepare a pre-emulsion. After the preemulsion was charged into the reactor, the temperature was raised to 60 ° C to allow the polymerization to proceed. When the conversion was 94%, 0.3 part by weight of ammonium hydroxide was added to terminate the polymerization. Unreacted monomers were removed by deodorization process and ammonia water, antioxidants, antifoaming agents and the like were added to prepare an acrylonitrile-butadiene latex having a solid concentration of 44.5% and a pH of 8.0. Thereafter, a composition for dip molding and a dip-molded article were prepared in the same manner as in Example 1 to prepare a glove-shaped dip-molded article, and physical properties thereof are shown in Table 1 below.

Comparative Example  2

A 10 L pressure reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet was installed to continuously feed monomers, an emulsifier and a polymerization initiator. The reactor was charged with 29 parts by weight of acrylonitrile, 6 parts by weight of methacrylic acid (corresponding to 100 parts by weight of total monomer), 3.0 parts by weight of sodium dodecylbenzenesulfonate, 1 part by weight of sodium naphthalate, 0.5 part by weight of ethylene oxide-based sulfonate, 0.9 part by weight of mercaptan and 200 parts by weight of ion-exchanged water were charged, and then the temperature was raised to 40 占 폚. 0.5 part by weight of calcium persulfate as a polymerization initiator was added thereto, stirred for about 480 minutes, and the temperature was raised to 60 DEG C to proceed the polymerization. When the conversion was 94%, 0.3 part by weight of ammonium hydroxide was added to stop the polymerization. Unreacted monomers were removed by deodorization process and ammonia water, antioxidants, antifoaming agents and the like were added to prepare an acrylonitrile-butadiene latex having a solid concentration of 44.5% and a pH of 8.0. Thereafter, a composition for dip molding and a dip-molded article were prepared in the same manner as in Example 1 to prepare a glove-shaped dip-molded article, and physical properties thereof are shown in Table 1 below.

Comparative Example  3

A 10 L pressure reactor equipped with a stirrer, a thermometer, a condenser and an inlet of nitrogen gas and equipped with a monomer, an emulsifier and a polymerization initiator was charged with 10 parts by weight of acrylonitrile, 20 parts by weight of methacrylic acid, 6 parts by weight of methacrylic acid (corresponding to 36 parts by weight of total monomer), 3.0 parts by weight of sodium dodecylbenzenesulfonate, 1 part by weight of sodium naphthalate, 0.5 part by weight of ethylene oxide- 0.9 part by weight of mercaptan and 200 parts by weight of ion-exchanged water were charged, and then the temperature was raised to 40 占 폚. 0.5 part by weight of calcium persulfate as a polymerization initiator was added thereto and stirred for about 240 minutes to prepare a seed.

19 parts by weight of acrylonitrile, 45 parts by weight of butadiene (corresponding to 64 parts by weight of total monomer), 0.5 part by weight of sodium dodecylbenzenesulfonate and 50 parts by weight of ion-exchanged water were mixed and stirred to prepare a pre-emulsion. After the preemulsion was charged into the reactor, the temperature was raised to 60 ° C to allow the polymerization to proceed. When the conversion was 94%, 0.3 part by weight of ammonium hydroxide was added to terminate the polymerization. Unreacted monomers were removed by deodorization process and ammonia water, antioxidants, antifoaming agents and the like were added to prepare an acrylonitrile-butadiene latex having a solid concentration of 44.5% and a pH of 8.0. Thereafter, a composition for dip molding and a dip-molded article were prepared in the same manner as in Example 1 to prepare a glove-shaped dip-molded article, and physical properties thereof are shown in Table 1 below.

[Test Example]

The physical properties of each of the dip-molded articles produced in Examples 1 to 3 and Comparative Examples 1 to 3 were measured by the following methods.

* Tensile Strength (MPa), Elongation (%), Stress (%) at 300% Elongation: A dumbbell-shaped specimen was prepared according to ASTM D-412. Subsequently, the test piece was pulled at a stretching speed of 500 mm / min, and the stress was measured at an elongation of 300%.

Thickness (mm) Tensile Strength (MPa) Elongation (%) Stress at 300% elongation (MPa) Example 1 0.063 45 631 5.2 Example 2 0.062 46 606 5.5 Example 3 0.063 44 615 5.3 Comparative Example 1 0.063 36 646 4.6 Comparative Example 2 0.062 38 653 4.7 Comparative Example 3 0.063 23 530 4.4

As shown in Table 1, when the ethylenic unsaturated acid monomer was distributed in the multilayer latex as in Examples 1 to 3, a rubber glove-shaped deep molded product having excellent mechanical properties such as tensile strength was produced .

On the other hand, when the ethylenically unsaturated acid monomer was distributed not only inside and outside the multi-layer latex as in Comparative Example 1 but also the ethylenically unsaturated acid monomer was distributed in the single-layer latex as in Comparative Example 2, It was confirmed that when the total monomer content constituting the shell layer is larger than the total monomer content constituting the seed, the mechanical properties such as tensile strength are poor.

Claims (15)

An ethylenically unsaturated nitrile monomer, and an ethylenically unsaturated acid monomer in an amount of more than 50 parts by weight based on 100 parts by weight of the total monomers constituting the seed and the shell layer; and a step of wrapping the seed, A shell layer comprising a diene monomer and an ethylenically unsaturated nitrile monomer in an amount of less than 50 parts by weight based on 100 parts by weight of the total monomers constituting the seed and the shell layer. The method according to claim 1,
Wherein the latex comprises 60 to 90 parts by weight of the seed and 100 parts by weight of the total monomers constituting the shell layer, and 100 parts by weight of the total of all the monomers constituting the seed and shell layer And 40 to 10 parts by weight based on 100 parts by weight of the emulsion polymerization latex. The method according to claim 1,
Wherein the total monomer constituting the seed and the shell layer is composed of 55 to 75% by weight of a conjugated diene monomer, 15 to 35% by weight of an ethylenically unsaturated nitrile monomer and 1 to 10% by weight of an ethylenically unsaturated acid monomer. Emulsion polymerization latex for molding. The method according to claim 1,
The conjugated diene-based monomer is at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 1,3-pentadiene and isoprene By weight based on the total weight of the emulsion polymerization latex. The method according to claim 1,
Wherein the ethylenically unsaturated nitrile monomer is at least one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile,? -Chloronitrile and? -Cyanoethyl acrylonitrile, Emulsion polymerization latex. The method according to claim 1,
The ethylenic unsaturated acid monomer may be at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, maleic anhydride, citraconic anhydride, styrenesulfonic acid, monobutyl fumarate, monobutyl maleate and mono-2-hydroxypropyl maleate Wherein the emulsion polymerization latex is at least one selected from the group consisting of the following. The ethylenically unsaturated nitrile monomer and the ethylenic unsaturated acid monomer in an amount of more than 50 parts by weight based on 100 parts by weight of the total monomers constituting the seed and the shell layer, followed by emulsion polymerization to prepare a seed; And
The seed is prepared by graft-emulsion-polymerizing a conjugated diene-based monomer and an ethylenically unsaturated nitrile-based monomer in a content of less than 50 parts by weight in 100 parts by weight of the total monomers constituting the seed and the shell layer, ; By weight based on the total weight of the emulsion polymerization latex. 8. The method of claim 7,
And adjusting the latex of the seed-skin layer to a pH of 7 to 9. A composition for dip molding comprising 80 to 99% by weight of an emulsion polymerization latex according to any one of claims 1 to 6. 10. The method of claim 9,
Wherein the solid content concentration of the dip molding composition is 5 to 35% by weight.  Comprising 20 to 1% by weight of at least one selected from the group consisting of a vulcanizing agent, an ionic crosslinking agent, a pigment, a filler, and a thickening agent in 80 to 99% by weight of the latex of any one of claims 1 to 6; By weight based on the total weight of the composition. 12. The method of claim 11,
Adjusting the composition to a pH of 8 to 12; Further comprising the step of: A lightweight dip-formed article having a thickness of 0.07 mm or less, prepared by dip-molding the composition of claim 9. a) applying a coagulant solution to the mold and drying;
b) applying the composition of claim 9 as a composition for dip molding to a mold to which a coagulant is applied to form a dip molding layer;
c) crosslinking said dip molding layer; And
d) peeling the cross-linked dip-formed layer from the mold to obtain a dip-molded article. 15. The method of claim 14,
Wherein the coagulant solution is a solution in which the coagulant is dissolved in water, alcohol or a mixture thereof in a concentration of 5 to 45% by weight.