JP4860252B2 - DIP MOLDING COMPOSITION AND DIP MOLDED ARTICLE - Google Patents

Description

  The present invention relates to a dip molding composition and a dip molded article. More specifically, the present invention relates to a dip-molding composition having high mechanical stability and a low allergenic dip-molded article having excellent physical properties such as texture, tensile strength, and elongation.

In recent years, rubber gloves have been widely used in various fields such as medical treatment (nosocomial infection, prevention of SARS infection, etc.), food processing field (O-157 problem) and electronic component manufacturing field due to increasing interest in safety and health. One method for producing these rubber gloves is the dip molding method. As the dip molding method, an anode adhesion dipping method in which a mold made of wood, glass, ceramics, metal or plastic is previously immersed in a coagulant solution and then immersed in a natural rubber latex composition or a synthetic rubber latex composition. In addition, there is known a Tigue adhesion dipping method in which a mold is dipped in a latex composition and then dipped in a coagulating liquid.
As typical dip molding latex, natural rubber latex or synthetic rubber latex such as acrylonitrile butadiene rubber (NBR rubber) is known. Recently, the former natural rubber latex may cause an allergic reaction depending on the amount of protein contained in some users. Synthetic rubber latex (NBR rubber-copolymer latex) not containing the latter protein has attracted attention. The amount used is also increasing. In order to improve the strength characteristics of such dip-molded products, it is common to use sulfur or a vulcanization accelerator. In recent years, however, the incidence of contact dermatitis based on delayed allergies to vulcanization accelerators in dip moldings such as gloves has been increasing, and development of dip moldings that do not use vulcanization accelerators has been required. Yes.
Further, with the increase in the amount of use, high productivity and high quality are being promoted for the dip-molding copolymer latex. For high productivity, good mechanical stability that does not form agglomerates is required when the dip molding composition is used. For quality improvement, physical properties at a high level such as texture, tensile strength and elongation of the dip-molded product obtained from the dip-molding composition are required.
Therefore, for example, a method for defining the molecular weight and gel content of the copolymer latex (JP-A-5-247266: Patent Document 1, JP-A-6-182788: Patent Document 2), and JP-A-2003-165814 ( Patent Document 3) proposes to use a latex composed of two types of copolymers having different glass transition temperatures by adjusting the composition of the copolymer. However, texture and other characteristics tend to conflict with each other, and it has been very difficult to satisfy all the characteristic balances at the same time. For example, when the amount of a conjugated diene compound such as butadiene having a low glass transition temperature is increased for the purpose of improving the texture, the texture is improved but the oil resistance and chemical resistance are poor.
JP-A 2003-165814 (Patent Document 3) proposes a dip-forming composition characterized by substantially not including any sulfur-containing vulcanizing agent, vulcanization accelerator, or zinc oxide. Yes. However, according to the study by the present inventors, there is a problem that physical properties sufficiently satisfactory in terms of strength cannot be obtained.
JP-A-5-247266 JP-A-6-182788 JP 2003-165814 A

  An object of the present invention is to provide a dip-molding composition having high mechanical stability and a hypoallergenic dip-molded article having excellent physical properties such as texture, tensile strength and elongation.

  As a result of intensive studies in view of the above-described circumstances, the present inventors have found that a specific range of composition, a copolymer latex using potassium hydroxide and / or sodium hydroxide and ammonia in combination as a pH adjuster, and a specific amount of zinc oxide. Can be used for dip molding compositions, so that dip molding compositions with high mechanical stability and physical properties such as texture, tensile strength and elongation can be used without using sulfur-containing vulcanizing agents and vulcanization accelerators. The present inventors have found that a hypoallergenic dip-molded article excellent in the above can be obtained and completed the present invention.

  That is, the present invention relates to 50 to 80% by weight of 1,3-butadiene, 15 to 50% by weight of acrylonitrile, 0 to 10% by weight of ethylenically unsaturated carboxylic acid monomer and other ethylenically unsaturated monomers copolymerizable therewith. A copolymer latex obtained by emulsion polymerization of a monomer comprising 0 to 35% by weight of a saturated monomer and using potassium hydroxide and / or sodium hydroxide and ammonia in combination as a pH adjuster, and the copolymer A composition for dip molding characterized by containing 0.7 to 5 parts by weight of zinc oxide with respect to 100 parts by weight of latex (in terms of solid content) and substantially free of sulfur-containing vulcanizing agent and vulcanization accelerator. And a dip-molded product obtained by dipping the dip-molding composition.

  According to the present invention, it is possible to obtain a dip molding composition having high mechanical stability, and a low allergic dip molding product having excellent physical properties such as texture, tensile strength, elongation, etc. Rubber gloves and the like widely used in various fields such as the electronic component manufacturing field can be obtained and are extremely useful.

The present invention is described in detail below.
The monomer composition of the copolymer latex in the present invention is 1,3-butadiene 50 to 80% by weight, acrylonitrile 15 to 50% by weight, ethylenically unsaturated carboxylic acid monomer 0 to 10% by weight, and It is composed of 0 to 35% by weight of another copolymerizable ethylenically unsaturated monomer.

  1,3-butadiene needs to be used in the range of 50 to 80% by weight in the total monomers. If the amount of 1,3-butadiene is less than 50% by weight, the latex polymer after drying does not exhibit properties as an NBR rubber, which is not preferable. When 1,3-butadiene exceeds 80% by weight, the oil resistance decreases. Preferably it is 55 to 75% by weight.

  Acrylonitrile needs to be used in the range of 15 to 50% by weight in all monomers. If acrylonitrile is less than 15% by weight, the oil resistance decreases, and if it exceeds 50% by weight, the latex polymer after drying does not exhibit properties as an NBR rubber, which is not preferable. Preferably it is 20 to 45 weight%.

Examples of the ethylenically unsaturated carboxylic acid monomer used in the present invention include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid and the like. Can do. In particular, methacrylic acid is preferred.
The ethylenically unsaturated carboxylic acid-based monomer needs to be used in the range of 0 to 10% by weight in all monomers. If the ethylenically unsaturated carboxylic acid monomer exceeds 10% by weight, the viscosity of the copolymer latex becomes too high, and there is a high possibility that handling problems will occur in all applications.

  Examples of other copolymerizable ethylenically unsaturated monomers used in the present invention include 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro- Aliphatic conjugated diene compounds such as 1,3-butadiene, substituted linear conjugated pentadienes, substituted and side chain conjugated hexadienes, for example, vinyl cyanide compounds such as methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile, such as , Aromatic vinyl compounds such as styrene and α-methylstyrene, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, etc. Unsaturated carboxylic acid alkyl ester compounds such as acrylic Ethylenically unsaturated carboxylic acid amide compounds such as amide, methacryloamide, N, N-dimethylacrylamide, N-methylolacrylamide, for example, carboxylic acid vinyl esters such as vinyl acetate, for example, methylaminoethyl (meth) acrylate, Examples thereof include ethylenically unsaturated amine compounds such as dimethylaminoethyl (meth) acrylate and 2-vinylpyridine, and one or more of them can be used.

  In the present invention, it is necessary to use potassium hydroxide and / or sodium hydroxide and ammonia in combination as a pH adjuster of the copolymer latex. In the present invention, mechanical stability is imparted to the copolymer latex and the dip molding composition by using potassium hydroxide and / or sodium hydroxide, and texture, tensile strength, elongation, etc. are given by using ammonia. It is considered that a dip-molded product having excellent physical properties can be obtained. There are no particular restrictions on the addition method and order of addition of these pH adjusters, which may be added after polymerization of the copolymer latex, after steam distillation, or at the time of adjusting the dip molding composition. In order to avoid the generation of aggregates at the time of addition, it is preferably added as an aqueous solution having a concentration of 0.1 to 40% by weight.

  Further, in the present invention, it is specified that potassium hydroxide and / or sodium hydroxide and ammonia are used in combination as a pH adjuster. However, within the range that does not impair the object of the present invention, these are further different. It is also possible to use a kind of basic substance.

  Although there is no restriction | limiting in particular about the gel content of the copolymer latex in this invention, From a viewpoint of the physical property balance of a feel, tensile strength, and elongation, a preferable gel content is 80 weight% or less. More preferably, it is 20 to 80% by weight.

  Moreover, there is no restriction | limiting in particular about the particle diameter of copolymer latex, However, The preferable particle diameter of copolymer latex is 0.2 micrometer or less. More preferably, it is 0.18 μm or less, and the most preferable particle diameter of the copolymer latex is 0.05 to 0.15 μm.

  In emulsion polymerization of the copolymer latex of the present invention, a conventional emulsifier, polymerization initiator, reducing agent, chain transfer agent, redox catalyst, hydrocarbon solvent, electrolyte, polymerization accelerator, chelating agent, etc. are used. be able to.

  Examples of emulsifiers that can be used in the production of the copolymer latex of the present invention include sulfate esters of higher alcohols, alkylbenzene sulfonates, alkyl diphenyl ether sulfonates, aliphatic sulfonates, aliphatic carboxylates, nonionic interfaces. Nonionic surfactants such as an anionic surfactant such as a sulfate ester of an activator or an alkyl ester type, an alkylphenyl ether type, and an alkyl ether type of polyethylene glycol are used, and one or more of these are used. be able to. In particular, alkylbenzene sulfonate and alkyl diphenyl ether sulfonate are preferable.

  As the polymerization initiator, water-soluble polymerization initiators such as potassium persulfate, sodium persulfate, ammonium persulfate, cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, acetyl peroxide, diisopropylbenzene hydroperoxide, An oil-soluble polymerization initiator such as 1,1,3,3-tetramethylbutyl hydroperoxide can be appropriately used. In particular, water-soluble polymerization initiators such as potassium persulfate, sodium persulfate and ammonium persulfate and oil-soluble polymerization initiators of cumene hydroperoxide are preferred.

  Specific examples of the reducing agent preferably used in the present invention include sulfite, bisulfite, pyrosulfite, nitrite, nithionate, thiosulfate, formaldehyde sulfonate, benzaldehyde sulfonate, Examples thereof include carboxylic acids such as L-ascorbic acid, tartaric acid and citric acid, further reducing sugars such as dextrose and saccharose, and amines such as dimethylaniline and triethanolamine. L-ascorbic acid is particularly preferable.

  Examples of the chain transfer agent that can be used for the production of the copolymer latex of the present invention include alkyls such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and n-stearyl mercaptan. Xanthogen compounds such as mercaptan, dimethylxanthogen disulfide, diisopropylxanthogen disulfide, terpinolene, thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, 2,6-di-t-butyl-4 -Halogenation of phenolic compounds such as methylphenol and styrenated phenol, allyl compounds such as allyl alcohol, dichloromethane, dibromomethane, carbon tetrabromide, etc. Hydrogenated compounds, α-benzyloxystyrene, α-benzyloxyacrylonitrile, vinyl ethers such as α-benzyloxyacrylamide, triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thiomalic acid, 2-ethylhexylthioglyco A rate etc. are mentioned, These can be used 1 type or 2 or more types. In particular, n-octyl mercaptan and t-dodecyl mercaptan are preferable. The amount of these chain transfer agents is not particularly limited, but is usually 0 to 5 parts by weight with respect to 100 parts by weight of the monomer.

  In the present invention, α-methylstyrene dimer can also be used as a chain transfer agent. α-Methylstyrene dimer includes 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene and 1,1,3-trimethyl-3-phenyl as isomers. Although there is indane, the α-methylstyrene dimer used in the present invention has a content of 2,4-diphenyl-4-methyl-1-pentene of 60% by weight or more, particularly 80% by weight or more. preferable. Since α-methylstyrene dimer has a high boiling point and remains in the latex particles even after the production of the copolymer latex, the amount used is 100 parts by weight of the monomer due to environmental problems different from the object of the present invention. The amount is preferably less than 2 parts by weight.

  In the polymerization, unsaturated hydrocarbons such as pentene, hexene, heptene, cyclopentene, cyclohexene, cycloheptene, 4-methylcyclohexene, and 1-methylcyclohexene may be used. In particular, cyclohexene, which has a moderately low boiling point and can be easily recovered and reused after the completion of polymerization by steam distillation or the like, is preferable from the viewpoint of environmental problems although it differs from the object of the present invention.

  Furthermore, anti-aging agents, preservatives, dispersants, thickeners and the like can be appropriately added to the copolymer latex as necessary.

  As the polymerization method in the present invention, any one of single-stage polymerization, two-stage polymerization, multi-stage polymerization, seed polymerization, power feed polymerization and the like may be adopted. Further, the addition method of various components in the polymerization method of the present invention is not particularly limited, and any of a batch addition method, a divided addition method, and a continuous addition method can be employed.

  The copolymer latex in the present invention is used as a copolymer latex for dip molding. In order to obtain a dip-molded product, for example, any of the conventionally known dip-molding methods such as a direct dipping method, an anode adhesion dipping method and a teag dipping method are applied.

  Hereinafter, the anode adhesion dipping method will be briefly described. First, the mold is dipped in a coagulating liquid, and then pulled up and dried to make the coagulant adhere to the mold surface. The coagulation liquid is obtained by dissolving a calcium salt such as calcium chloride, calcium nitrate, or calcium acetate in water or a hydrophilic organic solvent such as alcohol or ketone. The calcium concentration in the coagulation liquid is usually 5 to 50% by weight, preferably 10 to 30% by weight. If necessary, the coagulation liquid may contain a surfactant such as nonionic or anionic surfactant, and a filler such as calcium carbonate, talc, or silica gel. Next, the mold to which the coagulant is attached is immersed in the dip-molding copolymer latex composition and pulled up. At this time, the coagulant and the copolymer latex react to form a rubbery film on the mold. The obtained film is washed with water, dried, and then peeled off from the mold to form a dip-molded product.

The dip molding composition of the present invention contains 0.7 to 5 parts by weight of zinc oxide with respect to 100 parts by weight of the copolymer latex (in terms of solid content), and contains a sulfur-containing vulcanizing agent and a vulcanization accelerator. Need to be substantially free of

  About this zinc oxide, it is necessary to use in 0.7-5 weight part. If the amount of zinc oxide added is less than 0.7 parts by weight, sufficient film strength of the dip-formed product cannot be obtained, and if it exceeds 5 parts by weight, the texture of the dip-formed product becomes too hard. Preferably it is 0.7-3 weight part.

  The sulfur-containing vulcanizing agent and the vulcanization accelerator need not be substantially contained. Although it is particularly preferable that these substances are not contained in the dip molding composition at all, specifically, any of the substances is 0 for 100 parts by weight of copolymer latex (in terms of solid content). Use of 2 parts by weight or less is preferred.

  In addition, the dip molding composition of the present invention may be added to a rubber latex such as natural rubber latex or isoprene rubber latex, a pH adjuster such as potassium hydroxide, sodium hydroxide, or aqueous ammonia as necessary. As appropriate, fillers such as titanium dioxide, phthalic anhydride, benzoic acid, salicylic acid, magnesium carbonate, anti-aging agents such as styrenated phenol, imidazoles, paraphenylenediamine, and colorants such as first yellow, phthalocyanine blue, ultramarine blue, etc. You may mix | blend.

〔Example〕
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples, unless the summary is exceeded. In the examples, parts and percentages indicating percentages are based on weight unless otherwise specified. In addition, various physical properties in the examples were evaluated by the following methods.

The particle size number measured average particle size of the copolymer latex was measured by dynamic light scattering method. In the measurement, LPA-3000 / 3100 manufactured by Otsuka Electronics was used.

Measurement of Gel Content of Copolymer Latex It is dried for 24 hours in a room temperature atmosphere to prepare a film of copolymer latex. About 1 g of the film is weighed and placed in 400 cc of methyl ethyl ketone and expanded and dissolved for 48 hours. Thereafter, this was filtered through a 300-mesh wire mesh, the methyl ethyl ketone insoluble part captured by the wire mesh was dried and weighed, and the ratio of this weight to the initial film weight was calculated as a gel content in wt%.

Measurement of mechanical stability of dip molding composition The mechanical stability of the copolymer latex was evaluated by the following method. Using a Maron mechanical stability tester manufactured by Kumagai Riki Kogyo Co., Ltd., 50 g (solid content concentration: 33%) of a dip-molding composition filtered in advance with 300 mesh, a rotor rotation speed of 1000 rpm, a rotor load of 30 kg, and a rotation time After applying mechanical shear for 15 minutes, the sample was filtered through 300 mesh. After the trapped coagulum was dried, the ratio of the coagulum to the original solid content was determined by weight%. The results are shown in Table 2.
◯: The ratio of the generated coagulum is 0.01% by weight or less. Δ: The ratio of the generated coagulum exceeds 0.01% by weight and is 0.05% or less. Exceed

Each physical property of the dip-formed product was evaluated as follows, and the results are shown in Table 2.
Evaluation of the texture of the dip-formed product The evaluation of the texture was performed by measuring the tensile stress when the glove-shaped dip-formed product reached a 300% elongation at a tensile speed of 500 mm / min. A smaller value indicates a better texture.
Evaluation of tensile strength of dip-molded product Tensile strength evaluation was performed by pulling a glove-shaped dip-molded product at a pulling speed of 500 mm / min and measuring the tensile strength immediately before breaking.
Evaluation of Elongation of Dip Molded Products For evaluation of elongation, a glove-shaped dip molded product was pulled at a pulling speed of 500 mm / min, and the elongation immediately before breaking was measured.

Production of copolymer latex A In a pressure-resistant polymerization reactor, 155 parts of pure water under nitrogen atmosphere, 1.7 parts of sodium dodecylbenzenesulfonate as an emulsifier, 0.7 parts of sodium alkyldiphenyl ether disulfonate, After adding each monomer shown in Table 1, 0.65 parts of t-dodecyl mercaptan and 1.1 parts of L-ascorbic acid and stirring sufficiently, 0.6 parts of cumene hydroperoxide was charged and polymerized at 30 ° C. Started. 18 hours after the start of the polymerization, 0.05 part of diethylhydroxylamine was added as a polymerization terminator to complete the polymerization. Next, after adjusting the pH of the copolymer latex to 7.5 with an aqueous potassium hydroxide solution, steam distillation was performed at 90 ° C. for 9 hours to remove unreacted monomers and other low-boiling compounds. Furthermore, pH was adjusted to 8.3 with ammonia water having a concentration of 10% (hereinafter simply referred to as ammonia water) to obtain a copolymer latex A having a particle size and a gel content shown in Table 1.

Preparation of copolymer latex B In a pressure-resistant polymerization reactor, 140 parts of pure water under nitrogen atmosphere, 2.3 parts of sodium dodecylbenzenesulfonate as an emulsifier, each monomer shown in Table 1, and After adding 0.4 part of t-dodecyl mercaptan, 2.0 parts of cyclohexene and 1.0 part of L-ascorbic acid and stirring sufficiently, 0.5 part of potassium persulfate and 0.4 part of cumene hydroperoxide were charged. Polymerization was started at 35 ° C. 18 hours after the start of the polymerization, 0.05 part of diethylhydroxylamine was added as a polymerization terminator to complete the polymerization. Next, after adjusting the pH of the copolymer latex to 8.5 with aqueous ammonia, steam distillation was performed at 90 ° C. for 11 hours to remove unreacted monomers and other low-boiling compounds. Further, the pH was adjusted to 8.5 with an aqueous potassium hydroxide solution to obtain a copolymer latex B having the particle size and gel content shown in Table 1.

Preparation of copolymer latex C In a pressure-resistant polymerization reactor, 150 parts of pure water under a nitrogen atmosphere, 1.0 part of sodium alkyldiphenyl ether disulfonate as an emulsifier, 1.2 parts of sodium dodecylbenzenesulfonate, Each monomer shown in Table 1, 0.2 part of α-methylstyrene dimer, 0.75 part of t-dodecyl mercaptan and 0.7 part of L-ascorbic acid were added and stirred sufficiently. 3 parts and 0.7 parts of cumene hydroperoxide were charged and polymerization was started at 50 ° C. 13 hours after the start of the polymerization, 0.1 part of diethylhydroxylamine was added as a polymerization terminator to complete the polymerization. Subsequently, after adjusting pH of copolymer latex to 8.3 with potassium hydroxide aqueous solution, steam distillation was performed at 85 degreeC for 8 hours, and the unreacted monomer and other low boiling-point compounds were removed. Further, the pH was adjusted to 8.5 with an aqueous potassium hydroxide solution, and further adjusted to pH 8.8 with aqueous ammonia to obtain a copolymer latex C having a particle size and a gel content shown in Table 1.

Preparation of copolymer latex D Polymerization was carried out in the same manner as copolymer latex A, and then the pH of the copolymer latex was adjusted to 8.1 with an aqueous sodium hydroxide solution. Distillation was carried out for 9 hours to remove unreacted monomers and other low-boiling compounds. Furthermore, pH was adjusted to 8.5 with aqueous ammonia to obtain a copolymer latex D having a particle size and a gel content shown in Table 1.

Preparation of copolymer latex E In a pressure resistant polymerization reactor, under a nitrogen atmosphere, 160 parts of pure water, 2.8 parts of sodium dodecylbenzenesulfonate as an emulsifier, each monomer shown in Table 1, and After adding 0.25 part of t-dodecyl mercaptan and 1.5 part of L-ascorbic acid and stirring sufficiently, 0.8 part of cumene hydroperoxide was charged and polymerization was started at 35 ° C. 16 hours after the start of polymerization, 0.1 part of diethylhydroxylamine was added as a polymerization terminator to complete the polymerization. Subsequently, after adjusting pH of the copolymer latex to 7.8 with an aqueous potassium hydroxide solution, steam distillation was performed at 85 ° C. for 11 hours to remove unreacted monomers and other low-boiling compounds. Further, the pH was adjusted to 8.6 with aqueous ammonia to obtain a copolymer latex E having a particle size and a gel content shown in Table 1.

Preparation of copolymer latex F Polymerization similar to that of copolymer latex A was carried out, and then the copolymer latex was adjusted to pH 8.5 with an aqueous potassium hydroxide solution and then steamed at 90C. Distillation was carried out for 9 hours to remove unreacted monomers and other low-boiling compounds. A copolymer latex F having a pH of 8.5 and a particle size and a gel content shown in Table 1 was obtained.

Production of copolymer latex G Polymerization similar to that of copolymer latex A was carried out, and then the copolymer latex was adjusted to pH 9.1 with ammonia water, followed by steam distillation at 90C. It was performed for 9 hours to remove unreacted monomers and other low-boiling compounds. Furthermore, pH was adjusted to 8.2 with aqueous ammonia to obtain a copolymer latex G having a particle size and a gel content shown in Table 1.

Example 1
Preparation of Dip Molding Composition 100 parts by weight (converted to solid content) of copolymer latex A 0.7% of 3% aqueous potassium hydroxide solution, 1.5 parts of zinc oxide dispersed in a ball mill, and titanium dioxide 1 After adding 2 parts, deionized water was added to obtain a dip molding composition having a solid content of 33%. The measurement results of the mechanical stability of the dip molding composition are shown in Table 2.
Prepare a 15% strength aqueous solution of calcium nitrate as a coagulation solution for each dip-molded product, soak the glove mold pre-dried at 80 ° C. for 2 seconds, pull it up, and then level it and dry under rotation ( 80 ° C. × 2 minutes). Subsequently, the mold for gloves was immersed in the dip molding composition for 2 seconds, pulled up, and then dried horizontally (80 ° C. × 2 minutes) under rotation. Next, the mold for gloves was immersed in warm water at 40 ° C. for 3 minutes, washed, and then heated at 120 ° C. for 20 minutes to obtain a solid film on the surface of the mold for gloves. Finally, the solid coating was removed from the glove mold to obtain a glove-shaped dip-formed product. Table 2 shows the measurement results of the texture, tensile strength and elongation of the dip-formed product.

Examples 2-5, Comparative Examples 1-5
Table 2 shows the types of copolymer latex, potassium hydroxide (in Example 5 and Comparative Example 3 only, ammonia water having a concentration of 10% was used instead of potassium hydroxide), and the amount of zinc oxide added. A dip-molded composition was prepared in the same manner as in Example 1 except that the dip-molded product was obtained. Table 2 shows the measurement results of the mechanical stability of the dip molding composition and the measurement results of the texture, tensile strength and elongation of the dip molding product.

The composition, particle size, and gel content of each copolymer latex are shown in Table 1, and the formulation of each dip molding composition, the physical properties, and the physical properties of each dip molded product are summarized in Table 2.

As described above, by using the dip molding composition of the present invention, a dip molding composition having high mechanical stability and less aggregates is obtained, and by using the dip molding composition of the present invention, A dip-molded product having excellent texture, tensile strength and elongation can be obtained. Rubber gloves and the like widely used in various fields such as medical treatment, food processing field and electronic component manufacturing field can be obtained.

Claims (2)

1,3-butadiene 50 to 80% by weight, acrylonitrile 15 to 50% by weight, ethylenically unsaturated carboxylic acid monomer 4.3 to 10% by weight and other ethylenically unsaturated monomers copolymerizable therewith A copolymer latex obtained by emulsion polymerization of a monomer comprising 0 to 35% by weight of a body and using potassium hydroxide and / or sodium hydroxide and ammonia in combination as a pH adjuster, and 100% by weight of the copolymer latex Dip characterized in that it contains 0.7 to 5 parts by weight of zinc oxide with respect to parts (in terms of solid content), and the amount of sulfur-containing vulcanizing agent and vulcanization accelerator used is 0.2 parts by weight or less Molding composition. A dip-molded product obtained by dip-molding the dip-molding composition according to claim 1.