WO2016047418A1 - Method for producing dip-molded article, and dip-molded article - Google Patents

Method for producing dip-molded article, and dip-molded article Download PDF

Info

Publication number
WO2016047418A1
WO2016047418A1 PCT/JP2015/075182 JP2015075182W WO2016047418A1 WO 2016047418 A1 WO2016047418 A1 WO 2016047418A1 JP 2015075182 W JP2015075182 W JP 2015075182W WO 2016047418 A1 WO2016047418 A1 WO 2016047418A1
Authority
WO
WIPO (PCT)
Prior art keywords
dip
vulcanization
synthetic polyisoprene
mold
weight
Prior art date
Application number
PCT/JP2015/075182
Other languages
French (fr)
Japanese (ja)
Inventor
良幸 中村
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2016550085A priority Critical patent/JP6572902B2/en
Priority to SG11201701075UA priority patent/SG11201701075UA/en
Publication of WO2016047418A1 publication Critical patent/WO2016047418A1/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/02Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
    • B29C41/14Dipping a core
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/34Component parts, details or accessories; Auxiliary operations
    • B29C41/36Feeding the material on to the mould, core or other substrate
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/34Component parts, details or accessories; Auxiliary operations
    • B29C41/46Heating or cooling
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08LCOMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
    • C08L9/10Latex

Definitions

  • the present invention relates to a method for manufacturing a dip-molded body and a dip-molded body. More specifically, the present invention relates to a method for manufacturing a dip-molded body that does not generate cracks in a beading portion and has a high tear strength, and a dip-molded body manufactured by this manufacturing method.
  • a dip molding composition containing a latex of natural rubber is dip-molded to obtain a dip-molded body used in contact with a human body such as a nipple, a balloon, a glove, a balloon, and a sack.
  • a human body such as a nipple, a balloon, a glove, a balloon, and a sack.
  • natural rubber latex contains a protein that causes allergic symptoms in the human body
  • Patent Document 1 uses a specific vulcanization accelerator
  • Patent Document 2 uses a styrene-maleic acid monoester polymer salt, and the like. Is disclosed. However, although these methods improve the tensile strength but not the tear strength, methods for increasing the vulcanization density, such as a pre-vulcanization method of lengthening the aging process and strengthening the main vulcanization, are considered. It had been.
  • An object of the present invention is to provide a method for producing a dip-molded body having a high tear strength without occurrence of cracks in the beading portion, and a dip-molded body.
  • a dip molding composition containing a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator pre-vulcanize at a temperature of 30 ° C. or higher until the Swell Index in toluene is 25 or lower.
  • a method for producing a dip-molded body comprising a film forming step and a main vulcanization step of vulcanizing the film at a vulcanization temperature of 100 ° C. to 140 ° C .; (2) In the pre-vulcanization step, pre-vulcanization is performed until the Swell Index with toluene is 17 or less, The method for producing a dip-formed product according to (1), (3) The method for producing a dip-molded body according to (1) or (2), wherein the surface temperature of the mold in the film forming step is 65 ° C. or higher. (4) The method for producing a dip-molded body according to any one of (1) to (3), wherein the vulcanization temperature in the main vulcanization step is 110 ° C. to 130 ° C. (5) A dip-molded article obtained by the method for producing a dip-molded article according to any one of (1) to (4) is provided.
  • a dip-molded body manufacturing method and a dip-molded body having a high tear strength with no occurrence of cracks in the beading portion are provided.
  • the method for producing a dip-molded article of the present invention is 30 until the Swell Index in toluene is 25 or less for a dip-molding composition containing a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator.
  • the dip molding composition used in the present invention comprises a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator.
  • the synthetic polyisoprene latex used in the dip molding composition is a latex of synthetic polyisoprene obtained by polymerizing isoprene.
  • the synthetic polyisoprene may be a copolymer of another ethylenically unsaturated monomer copolymerizable with isoprene.
  • the content of isoprene units in the synthetic polyisoprene is flexible, and it is easy to obtain a dip-molded article excellent in tensile strength. Therefore, the content is preferably 70% by weight or more, more preferably 90% by weight based on all monomer units. % Or more, more preferably 95% by weight or more, and particularly preferably 100% by weight (isoprene homopolymer).
  • Examples of other ethylenically unsaturated monomers copolymerizable with isoprene include conjugated diene monomers other than isoprene such as butadiene, chloroprene and 1,3-pentadiene; acrylonitrile, methacrylonitrile, fumaronitrile, ⁇ - Ethylenically unsaturated nitrile monomers such as chloroacrylonitrile; vinyl aromatic monomers such as styrene and alkylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) And ethylenically unsaturated carboxylic acid ester monomers such as 2-ethylhexyl acrylate; crosslinkable monomers such as divinylbenzene, diethylene glycol di (meth) acrylate, and pentaerythritol (meth) acrylate.
  • isoprene units in the synthetic polyisoprene which are cis bond units, trans bond units, 1,2-vinyl bond units, and 3,4-vinyl bond units, depending on the bond state of isoprene.
  • the content of cis-bond units in the isoprene units contained in the synthetic polyisoprene is preferably 70% by weight or more, more preferably 90%, based on the total isoprene units. % By weight or more, particularly preferably 95% by weight or more.
  • the weight average molecular weight of the synthetic polyisoprene is 10,000 to 5,000,000, preferably 500,000 to 5,000,000, particularly preferably 800,000 in terms of standard polystyrene by gel permeation chromatography analysis. 000 to 3,000,000. If the weight average molecular weight of the synthetic polyisoprene is too small, the tensile strength of the dip-molded product tends to decrease. Conversely, if it is too large, the synthetic polyisoprene latex tends to be difficult to produce.
  • the polymer Mooney viscosity [ML 1 + 4 , 100 ° C.] of the synthetic polyisoprene is 50 to 80, preferably 60 to 80, particularly preferably 70 to 80.
  • the volume average particle diameter of latex particles (synthetic polyisoprene particles) in the synthetic polyisoprene latex is preferably 0.5 to 10 ⁇ m, more preferably 0.5 to 3 ⁇ m, and particularly preferably 0.5 to 2 ⁇ m. . If the volume average particle size is too small, the latex viscosity may become too high and difficult to handle. Conversely, if the volume average particle size is too large, a film may be formed on the latex surface when the synthetic polyisoprene latex is stored. .
  • the electrical conductivity of the synthetic polyisoprene latex is preferably 1.0 mS / cm to 2.0 mS / cm.
  • the conductivity is less than 1.0 mS / cm, a large amount of aggregates may be generated during emulsification or concentration.
  • the electrical conductivity exceeds 2.0 mS / cm, foaming becomes severe at the time of solvent removal, foaming is severe at the time of transferring the composition for dip molding or at the time of blending, and defects such as pinholes are left in the glove. There is a case.
  • the conductivity is a value measured at a measurement temperature of 25 ° C. using a conductivity meter (trade name: SG78-FK2) manufactured by METLER TOLEDO.
  • the total content of the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent in the synthetic polyisoprene latex is preferably 500 ppm by weight or less.
  • the alicyclic hydrocarbon solvent is preferably cyclohexane, and the aromatic hydrocarbon solvent is preferably toluene. If the total content of the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent, particularly the total content of cyclohexane and toluene, is too large, the odor of the dip-forming composition tends to be tight.
  • the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent are organic solvents for dissolving or finely dispersing synthetic polyisoprene, which will be described later, when producing synthetic polyisoprene latex.
  • the total content of the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent can be measured by a generally usable measurement method such as a gas chromatography method.
  • a method for producing a synthetic polyisoprene latex for example, (1) a solution or fine suspension of a synthetic polyisoprene dissolved or finely dispersed in an organic solvent is emulsified in water in the presence of a surfactant, and if necessary, A method for producing a synthetic polyisoprene latex by removing an organic solvent, (2) emulsion polymerization or suspension polymerization of isoprene alone or a mixture of ethylenically unsaturated monomers copolymerizable with isoprene, A method of directly producing a synthetic polyisoprene latex is mentioned, but a synthetic polyisoprene having a high ratio of cis bond units in the isoprene unit can be used, and a dip molded article having excellent tensile strength can be obtained.
  • the production method (1) is preferred.
  • Synthetic polyisoprene is produced in an inert polymerization solvent using a conventionally known method, for example, a Ziegler polymerization catalyst composed of trialkylaluminum-titanium tetrachloride or an alkyllithium polymerization catalyst such as n-butyllithium or sec-butyllithium. It can be obtained by solution polymerization of isoprene.
  • the obtained polymer solution of synthetic polyisoprene may be used as it is, but after the solid synthetic polyisoprene is taken out from the polymer solution, the solid synthetic polyisoprene is dissolved in an organic solvent and used. You can also.
  • impurities such as a residue of the polymerization catalyst remaining in the polymer solution may be removed.
  • Commercially available solid synthetic polyisoprene may also be used.
  • Examples of the organic solvent used in the production method (1) include aromatic hydrocarbon solvents such as benzene, toluene and xylene; alicyclic hydrocarbon solvents such as cyclopentane, cyclopentene, cyclohexane and cyclohexene; pentane, hexane, And aliphatic hydrocarbon solvents such as heptane; halogenated hydrocarbon solvents such as methylene chloride, chloroform and ethylene dichloride; Of these, aromatic hydrocarbon solvents and alicyclic hydrocarbon solvents are preferred, with cyclohexane and toluene being particularly preferred.
  • the amount of the organic solvent used is preferably 2,000 parts by weight or less, more preferably 20 to 1,500 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene.
  • Examples of the surfactant used in the production method of (1) above include nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester; Sodium or potassium salts of fatty acids such as lauric acid, myristic acid, palmitic acid, oleic acid, linolenic acid, rosin acid, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, higher alcohol sulfates, alkyl sulfosuccinates, etc.
  • nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester
  • Sodium or potassium salts of fatty acids such as lauric acid, myristic acid, palmitic acid, oleic acid, lino
  • Anionic surfactants cationic surfactants such as alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, alkylbenzyldimethylammonium chloride copolymerizable surfactants such as sulfoesters of ⁇ , ⁇ -unsaturated carboxylic acids, sulfate esters of ⁇ , ⁇ -unsaturated carboxylic acids, sulfoalkylaryl ethers, and the like.
  • Preferred are sodium rosinate and sodium dodecylbenzenesulfonate.
  • these surfactants may be used individually by 1 type, and may use 2 or more types together.
  • the amount of the surfactant used is preferably 0.5 to 50 parts by weight, more preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If the amount is too small, the stability of the latex tends to be inferior. On the other hand, if the amount is too large, foaming tends to occur and problems may occur during dip molding.
  • the amount of water used in the production method (1) is preferably 50 to 5,000 parts by weight, more preferably 100 to 3,000 parts by weight, based on 100 parts by weight of the synthetic polyisoprene.
  • water used examples include hard water, soft water, ion exchange water, distilled water, and zeolite water.
  • An apparatus for emulsifying an organic solvent solution or fine suspension of synthetic polyisoprene in water in the presence of a surfactant can be used without particular limitation as long as it is generally commercially available as an emulsifier or a disperser.
  • the addition method of the surfactant is not particularly limited, and the emulsified liquid may be added during the emulsification operation even if it is added to the organic solvent solution or fine suspension of water and / or synthetic polyisoprene in advance. It may be added in a batch, or may be added all at once or dividedly.
  • emulsifier examples include a batch type emulsifier such as trade name: homogenizer (manufactured by IKA), trade name: polytron (manufactured by Kinematica), trade name: TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), etc.
  • a batch type emulsifier such as trade name: homogenizer (manufactured by IKA), trade name: polytron (manufactured by Kinematica), trade name: TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), etc.
  • TK Pipeline Homomixer manufactured by Koki Kogyo Kogyo Co., Ltd.
  • Product Name: Trigonal Wet Fine Crusher Product name: Cavitron (manufactured by Eurotech), product name: Milder (manufactured by Taiheiyo Kiko Co., Ltd.), product name: Fine Flow Mill (manufactured by Taiheiyo Kiko Co., Ltd.), etc.
  • Microfluidizer manufactured by Mizuho Kogyo Co., Ltd.
  • Nanomizer manufactured by Nanomizer Co., Ltd.
  • APV Gaurin manufactured by Gaulin Co., Ltd.
  • Membrane emulsifiers such as an emulsifier (made by Chilling Industries Co., Ltd.)
  • the conditions of the emulsification operation by the emulsification apparatus are not particularly limited, and the treatment temperature, the treatment time, and the like may be appropriately selected so as to obtain a desired dispersion state.
  • a synthetic polyisoprene latex by removing the organic solvent from the emulsion obtained through the emulsification operation.
  • the method for removing the organic solvent from the emulsion is not particularly limited, and methods such as vacuum distillation, atmospheric distillation, steam distillation, and centrifugation can be employed.
  • a concentration operation may be performed by a method such as vacuum distillation, atmospheric distillation, centrifugation, membrane concentration or the like.
  • the solid content concentration of the synthetic polyisoprene latex is preferably 30 to 70% by weight, more preferably 40 to 70% by weight. If the solid content concentration is too low, there is a concern that the synthetic polyisoprene particles are separated when the synthetic polyisoprene latex is stored. Conversely, if the solid content concentration is too high, the synthetic polyisoprene particles are aggregated to generate coarse aggregates. There is a case.
  • Synthetic polyisoprene latex is usually added in the latex field, and includes additives such as pH adjusters, antifoaming agents, preservatives, crosslinking agents, chelating agents, oxygen scavengers, dispersants, and anti-aging agents. May be blended.
  • pH adjuster examples include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal hydrogen carbonates such as sodium bicarbonate; ammonia
  • alkali metal hydroxides such as sodium hydroxide and potassium hydroxide
  • alkali metal carbonates such as sodium carbonate and potassium carbonate
  • alkali metal hydrogen carbonates such as sodium bicarbonate
  • ammonia An organic amine compound such as trimethylamine or triethanolamine; an alkali metal hydroxide or ammonia is preferred.
  • vulcanizing agent examples include powdered sulfur, sulfur white, precipitated sulfur, colloidal sulfur, surface-treated sulfur, insoluble sulfur, and the like; sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, N, N'- Sulfur-containing compounds such as dithio-bis (hexahydro-2H-azepinone-2), phosphorus-containing polysulfide, polymer polysulfide, 2- (4′-morpholinodithio) benzothiazole, and the like can be used. Of these, sulfur is preferably used. These vulcanizing agents may be used alone or in combination of two or more.
  • the amount of the vulcanizing agent is not particularly limited, but is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If the amount is too small or too large, the tensile strength of the dip-molded product tends to decrease.
  • vulcanization accelerator As the vulcanization accelerator, those usually used in dip molding can be used. For example, diethyldithiocarbamic acid, dibutyldithiocarbamic acid, di-2-ethylhexyldithiocarbamic acid, dicyclohexyldithiocarbamic acid, diphenyldithiocarbamic acid, dibenzyldithiocarbamic acid, etc.
  • These vulcanization accelerators may be used alone or in combination of two or more.
  • the amount of the vulcanization accelerator used is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If this amount is small, the tensile strength of the dip-molded product may decrease. On the other hand, if this amount is excessive, the elongation and tensile strength of the dip-formed product may be lowered.
  • the dip molding composition used in the present invention preferably further contains zinc oxide.
  • the content of zinc oxide is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 2 parts by weight with respect to 100 parts by weight of synthetic polyisoprene. If this amount is too small, the tensile strength of the dip-molded product tends to decrease. On the other hand, if the amount is too large, the stability of the synthetic polyisoprene particles in the dip-molding composition decreases and coarse aggregates are generated. There is a case.
  • the dip molding composition used in the present invention may contain a dispersant as necessary.
  • the dispersant include lauric acid, myristic acid, palmitic acid, oleic acid, linolenic acid, and rosin acid.
  • examples include sodium or potassium salts of fatty acids, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, anionic surfactants such as higher alcohol sulfate esters, alkylsulfosuccinates, etc., but sodium dodecylbenzenesulfonate is particularly preferable.
  • these surfactants may be used individually by 1 type, and may use 2 or more types together.
  • the amount of the dispersing agent used is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If this amount is small, the blending stability of the dip-forming composition may be reduced, or aggregates may increase during pre-vulcanization. On the other hand, if this amount is excessive, the dip-forming composition tends to foam and pinholes are likely to occur.
  • the dip molding composition of the present invention further requires a compounding agent such as an anti-aging agent; a reinforcing agent such as carbon black, silica and talc; a filler such as calcium carbonate and clay; an ultraviolet absorber; a plasticizer; It can be blended according to.
  • a compounding agent such as an anti-aging agent
  • a reinforcing agent such as carbon black, silica and talc
  • a filler such as calcium carbonate and clay
  • an ultraviolet absorber such as calcium carbonate and clay
  • plasticizer a plasticizer
  • Antiaging agents include 2,6-di-4-methylphenol, 2,6-di-t-butylphenol, butylhydroxyanisole, 2,6-di-t-butyl- ⁇ -dimethylamino-p-cresol, Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, styrenated phenol, 2,2′-methylene-bis (6- ⁇ -methyl-benzyl-p-cresol), 4, Butylation of 4'-methylenebis (2,6-di-tert-butylphenol), 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), alkylated bisphenol, p-cresol and dicyclopentadiene Phenol-based antioxidants containing no sulfur atom such as reaction products; 2,2′-thiobis- (4-methyl-6-t-butylphenol) 4,4′-thiobis- (6-tert-butyl-o-cresol), 2,6-
  • Sulfur ester anti-aging agents of: phenyl- ⁇ -naphthylamine, phenyl- ⁇ -naphthylamine, p- (p-toluenesulfonylamido) -diphenylamine, 4,4 ′-( ⁇ , ⁇ -dimethylbenzyl) diphenylamine, N, N -Diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl- -Amine-based antioxidants such as phenylenediamine and butyraldehyde-aniline condensates; Quinoline-based antioxidants such as 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline; 2,5-di- And hydroquinone anti-aging agents such as (t-amyl) hydroquinone. These anti-aging agents may be used alone or in combination of two or more.
  • the amount of the antiaging agent used is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If this amount is too small, the synthetic polyisoprene may deteriorate. Moreover, when there is too much this quantity, the tensile strength of a dip molded object may fall.
  • the method for preparing the dip molding composition is not particularly limited.
  • a dispersing machine such as a ball mill, a kneader, or a disper
  • a latex of synthetic polyisoprene is added to a vulcanizing agent, a vulcanization accelerator, zinc oxide, the above-described dispersing agent, and a monovalent dialkyldithiocarbamic acid.
  • a method of mixing a salt and other compounding agents such as an anti-aging agent compounded as necessary, or an aqueous dispersion of a desired compounding component other than a synthetic polyisoprene latex using the above-described disperser in advance.
  • Examples thereof include a method of mixing the aqueous dispersion with a synthetic polyisoprene latex after the preparation.
  • the above-mentioned dispersant and a monovalent salt of dialkyldithiocarbamic acid are mixed in advance with the latex of synthetic polyisoprene, and then other compounding agents such as a vulcanizing agent, a vulcanization accelerator, and an anti-aging agent are added.
  • the pH of the dip molding composition is preferably 7 or more, more preferably in the range of pH 8-12.
  • the solid content concentration of the dip molding composition is preferably in the range of 15 to 65% by weight.
  • the method for producing a dip-molded product of the present invention includes a pre-vulcanization step of aging (also referred to as pre-vulcanization) before subjecting the dip-molding composition to dip molding.
  • the Swell Index in toluene is 25 or less, preferably 17 or less, for a dip-forming composition containing a synthetic polyisoprene polymer, a vulcanizing agent and a vulcanization accelerator.
  • Pre-vulcanization is performed at a temperature of 30 ° C. or higher until If the Swell Index after pre-vulcanization is too large, the tear strength of the resulting dip-molded product will be reduced.
  • the pre-curing time is not particularly limited and depends on the pre-curing temperature, but is preferably 1 to 14 days, and more preferably 1 to 7 days. If this time is too short or too long, the tensile strength of the resulting dip-formed product tends to decrease.
  • pre-vulcanization After pre-vulcanization, it is preferably stored at a temperature of 10 ° C. to 30 ° C. until it is used for dip molding. When stored at a high temperature, the tensile strength of the resulting dip-molded product tends to decrease.
  • the method for producing a dip-molded article of the present invention includes a film forming step of dip-molding a dip-forming composition that has been pre-vulcanized in the pre-vulcanization step.
  • a mold having a surface temperature of 60 ° C. or higher, preferably 65 ° C. or higher is dipped to form a film on the surface of the mold.
  • the mold is immersed in the dip molding composition, the composition is deposited on the surface of the mold, the mold is then lifted from the composition, and then the composition is deposited on the surface of the mold. Is a method of drying.
  • the surface temperature of the mold before being immersed in the dip molding composition is preheated to 60 ° C. or higher, preferably 65 ° C. or higher. If the surface temperature is too low, cracks may occur in the beading part when the obtained dip-formed product is used as a glove.
  • a coagulant can be used as necessary before the mold is dipped in the dip molding composition or after the mold is lifted from the dip molding composition.
  • the method of using the coagulant include a method in which a mold before dipping in a dip molding composition is immersed in a coagulant solution to attach the coagulant to the mold (anode coagulation dipping method), for dip molding
  • anode coagulation dipping method there is a method of immersing the mold on which the composition is deposited in a coagulant solution
  • the anode adhesion dipping method is preferred in that a dip-formed product with little thickness unevenness can be obtained.
  • coagulants 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; water-soluble polyvalent metal salts such as calcium sulfate, magnesium sulfate, and sulfates such as aluminum sulfate; Of these, calcium salts are preferable, and calcium nitrate is more preferable. These water-soluble polyvalent metal salts may be used alone or in combination of two or more.
  • the coagulant is preferably used in the form of an aqueous solution.
  • This aqueous solution may further contain a water-soluble organic solvent such as methyl alcohol or ethyl alcohol, or a nonionic surfactant.
  • the concentration of the coagulant varies depending on the type of the water-soluble polyvalent metal salt, but is preferably 5 to 50% by weight, more preferably 10 to 30% by weight.
  • the deposit (film) formed on the mold is usually dried by heating. What is necessary is just to select drying conditions suitably.
  • the method for producing a dip-molded article of the present invention includes a main vulcanization step of vulcanizing by heating a deposit (film) formed on a mold.
  • the membrane is vulcanized at a vulcanization temperature of 100 ° C to 140 ° C, preferably 110 ° C to 130 ° C. If the vulcanization temperature is too high, the tear strength of the resulting dip-molded product is lowered.
  • the heating time in this vulcanization step is preferably 10 to 120 minutes.
  • the heating method is not particularly limited, and examples thereof include a method of heating in a dryer, a method of heating with warm air in an oven, and a method of heating by irradiating infrared rays.
  • the mold before or after heating the mold on which the dip molding composition is deposited, the mold is washed with water or warm water in order to remove water-soluble impurities (for example, excess surfactant or coagulant). It is preferable.
  • water-soluble impurities for example, excess surfactant or coagulant.
  • the dip-molded body after this vulcanization process is detached from the mold.
  • the desorption method include a method of peeling from a mold by hand, a method of peeling by water pressure or compressed air pressure, and the like. If the dip-formed body in the middle of the main vulcanization process has sufficient strength against desorption, it may be desorbed in the middle of the main vulcanization process, and then the subsequent main vulcanization process may be continued.
  • the dip-molded body is a glove
  • the glove is made of inorganic fine particles such as talc and calcium carbonate or organic fine particles such as starch particles It may be dispersed on the surface, an elastomer layer containing fine particles may be formed on the surface of the glove, or the surface layer of the glove may be chlorinated.
  • the dip-forming composition that had been subjected to the pre-vulcanization step (aging) was cast into an aluminum pan with a dropper so that the amount was about 1 g dry, and was dried under reduced pressure in a vacuum dryer at room temperature for 3 hours. It was. The obtained dried product was cut into a sample.
  • the sample was precisely weighed in an 80-mesh wire mesh (this weight is A), and 100 mL of toluene was injected and allowed to stand for 24 hours. After 24 hours, the 80-mesh wire mesh was taken out, excess toluene was removed, and the swollen sample was immediately weighed together with the wire mesh (this weight is designated as B).
  • the tensile strength of the dip-molded body was measured based on ASTM D412. Specifically, a film of a dip-molded product was punched with a dumbbell (SDMK-100C: manufactured by Dumbbell) to prepare a test piece for measuring tensile strength. The test piece was pulled with a Tensilon universal testing machine (trade name “RTG-1210”, manufactured by A & D Co., Ltd.) at a pulling speed of 500 mm / min, tensile strength immediately before break (unit: MPa), elongation just before break (unit: :%).
  • the tear strength of the dip-formed body was measured based on ASTM D624-00. Specifically, a film-shaped dip-formed body having a film thickness of about 0.2 mm is conditioned for 24 hours or more in a constant temperature and humidity chamber at 23 ° C. and 50% relative humidity, and then dumbbell (SDMK-1000C: manufactured by Dumbbell) ) To produce a punched specimen. The test piece was pulled with a Tensilon universal testing machine (trade name “RTC-1225A”, manufactured by Orientec Co., Ltd.) at a tensile speed of 500 mm / min, and the tear strength (unit: N / mm) was measured.
  • RTC-1225A manufactured by Orientec Co., Ltd.
  • Example 1 (Dip molding composition) Synthetic polyisoprene latex (trade name “NIPOL ME1150”, manufactured by Nippon Zeon Co., Ltd., homopolymer of isoprene, solid content concentration 61%, average particle size 1.2 ⁇ m, weight average molecular weight 1,300,000, cis bond While stirring a unit amount of 98%, sodium dodecylbenzenesulfonate having a concentration of 10% by weight was added to 100 parts of the synthetic polyisoprene polymer so as to be 1 part in terms of solid content.
  • Synthetic polyisoprene latex trade name “NIPOL ME1150”, manufactured by Nippon Zeon Co., Ltd., homopolymer of isoprene, solid content concentration 61%, average particle size 1.2 ⁇ m, weight average molecular weight 1,300,000, cis bond While stirring a unit amount of 98%, sodium dodecylbenzenesulfonate having a concentration of 10% by weight was added
  • the weight average molecular weight of the synthetic polyisoprene latex is obtained by dissolving the synthetic polyisoprene latex in tetrahydrofuran to a solid content concentration of 0.1% by weight, and subjecting this solution to gel permeation chromatography analysis. It is a value calculated as a weight average molecular weight in terms of standard polystyrene.
  • the amount of cis-bond units is determined based on the total isoprene units in the synthetic polyisoprene obtained by 1 H-NMR analysis after drying the coagulated product obtained by adding methanol to the synthetic polyisoprene latex and coagulating it. The ratio of cis bond units.
  • the hand mold coated with the coagulant was taken out of the oven, and dipped in the dip molding composition for 10 seconds with the surface temperature of the hand mold just before dipping at 65 ° C. Then, after air-drying for 10 minutes at room temperature, beading was carried out and left still for 10 minutes. Ten minutes later, the occurrence of cracks in the beading portion was visually determined, but no cracks were seen. After this hand mold was immersed in warm water at 50 ° C. for 2 minutes, the presence or absence of cracks in the beading portion was similarly judged visually, but no cracks were observed.
  • the hand mold covered with the vulcanized film was cooled to room temperature and sprayed with talc, and then the film was peeled from the hand mold.
  • Table 1 shows the measurement results of the tensile strength, elongation just before breakage, and tear strength of the obtained dip-formed body.
  • Example 2 A dip-molded body was produced in the same manner as in Example 1 except that aging was performed until the Swell Index reached 22 in the pre-vulcanization step, and evaluation was performed in the same manner. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
  • Example 3 A dip-molded body was produced and evaluated in the same manner as in Example 1 except that the temperature of the main vulcanization in the main vulcanization step was 140 ° C. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
  • Example 1 A dip-molded body was produced in the same manner as in Example 1 except that the ripening was stopped when the Swell Index reached 27 in the pre-vulcanization step, and evaluation was performed in the same manner. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
  • Example 2 A dip-molded body was produced in the same manner as in Example 1 except that it was immersed in the dip-molding composition at a surface temperature of the hand mold of 50 ° C. in the film forming step, and evaluated in the same manner. The results are shown in Table 1. In addition, many cracks were seen in the beading part after beading. Moreover, during immersion in warm water, cracks in the beading portion further increased after vulcanization, resulting in a dip molded article having a poor appearance.
  • Example 3 A dip-molded body was produced in the same manner as in Example 1 except that the surface temperature of the hand mold was set to 55 ° C. and immersed in the dip-molding composition in the film forming step, and evaluation was performed in the same manner. The results are shown in Table 1. In addition, two places cracks were seen in the beading part after beading. Also, during immersion in warm water, cracks in the beading portion did not increase after vulcanization, but a dip molded article having a poor appearance was obtained.
  • Example 4 A dip-molded body was produced in the same manner as in Example 1 except that the temperature of the main vulcanization in the main vulcanization step was 160 ° C., and the evaluation was performed in the same manner. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
  • Comparative Example 2 and Comparative Example 3 where the surface temperature of the hand mold was low, a difference was observed in the degree of cracks in the beading part. As the surface temperature of the hand mold decreased, the cracks tended to increase. Furthermore, in Comparative Example 4 in which the vulcanization temperature was increased, no crack was observed in the beading portion, but the tensile strength and tear strength of the dip-formed product were low.
  • the dip molded product obtained by the dip molded product manufacturing method of the present invention has no cracks in the beading portion and has a high tear strength. For this reason, it is suitable for surgical gloves, diagnostic gloves, household gloves, agricultural gloves, fishery gloves, and industrial gloves;

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Moulding By Coating Moulds (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

A method for producing a dip-molded article comprises: a pre-vulcanization step of subjecting a dip-molding composition comprising a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization promotor to a pre-vulcanization procedure at a temperature of 30°C or higher until the swell index of a product in toluene becomes 25 or less; a film formation step of immersing a mold having a surface temperature of 60°C or higher in the dip-molding composition that has been subjected to the pre-vulcanization procedure in the pre-vulcanization step to form a film on the surface of the mold; and a vulcanization step of vulcanizing the film at a vulcanization temperature of 100 to 140°C.

Description

ディップ成形体の製造方法、およびディップ成形体DIP MOLDED MANUFACTURING METHOD AND DIP MOLDED BODY
 本発明は、ディップ成形体の製造方法、およびディップ成形体に関する。さらに詳しくは、ビーディング部分にクラックの発生がなく、高い引裂強度を有するディップ成形体の製造方法、およびこの製造方法で製造されたディップ成形体に関する。 The present invention relates to a method for manufacturing a dip-molded body and a dip-molded body. More specifically, the present invention relates to a method for manufacturing a dip-molded body that does not generate cracks in a beading portion and has a high tear strength, and a dip-molded body manufactured by this manufacturing method.
 従来、天然ゴムのラテックスを含有するディップ成形用組成物をディップ成形して、乳首、風船、手袋、バルーン、サック等の人体と接触して使用されるディップ成形体が得られることが知られている。しかしながら、天然ゴムのラテックスは、人体にアレルギー症状を引き起こすような蛋白質を含有するため、生体粘膜又は臓器と直接接触するディップ成形体としては問題がある場合があった。そのため、天然ゴムのラテックスの代わりに合成ポリイソプレン重合体のラテックスを用いる検討がされてきている。 Conventionally, it is known that a dip molding composition containing a latex of natural rubber is dip-molded to obtain a dip-molded body used in contact with a human body such as a nipple, a balloon, a glove, a balloon, and a sack. Yes. However, since natural rubber latex contains a protein that causes allergic symptoms in the human body, there are cases in which there is a problem as a dip-molded product that is in direct contact with a living mucous membrane or an organ. Therefore, studies have been made to use synthetic polyisoprene polymer latex instead of natural rubber latex.
 しかしながら、合成ポリイソプレンラテックスにより得られるディップ成形体を手袋として用いると、天然ゴムのラテックスにより得られるディップ成形体を手袋として用いる場合と比べて引裂強度が劣るため、手袋を着脱する際や医療行為中に破れたりする虞があった。このため、高い引裂強度を有する合成ポリイソプレンラテックスを用いた手袋の開発が求められていた。 However, when a dip molded body obtained from synthetic polyisoprene latex is used as a glove, the tear strength is inferior to that when a dip molded body obtained from natural rubber latex is used as a glove. There was a risk of tearing inside. For this reason, development of the glove using the synthetic polyisoprene latex which has high tear strength was calculated | required.
 手袋の強度を向上させる方法として、例えば、特許文献1には、特定の加硫促進剤を使用する方法、特許文献2には、スチレン-マレイン酸モノエステル重合体の塩を使用する方法、等が開示されている。しかし、これらの方法では引張強さは向上するものの引裂強度が十分に向上しないため、前加硫と呼ばれる熟成工程を長くする方法や本加硫を強くする等の加硫密度を高める方法が検討されていた。 As a method for improving the strength of gloves, for example, Patent Document 1 uses a specific vulcanization accelerator, Patent Document 2 uses a styrene-maleic acid monoester polymer salt, and the like. Is disclosed. However, although these methods improve the tensile strength but not the tear strength, methods for increasing the vulcanization density, such as a pre-vulcanization method of lengthening the aging process and strengthening the main vulcanization, are considered. It had been.
 ところが、加硫密度を高めすぎると手袋のビーディング部分にクラックが生じやすいという問題があった。また、ビーディング部にクラックが発生すると手袋の外観不良問題に加えて、そのクラック部分から裂けやすくなるため、結局、引裂強度が低下する原因になっていた。このため、高い引裂強度を有し、ビーディング部にクラックが発生しないディップ成形体の開発が待たれていた。 However, if the vulcanization density is too high, there is a problem that cracks are likely to occur in the beading portion of the glove. In addition, if a crack occurs in the beading portion, it becomes easy to tear from the crack portion in addition to the problem of poor appearance of the glove, which eventually causes a decrease in tear strength. For this reason, development of a dip-molded body that has high tear strength and does not generate cracks in the beading portion has been awaited.
特開2009-209229号公報JP 2009-209229 A 特開2011-219543号公報JP 2011-219543 A
 本発明は、ビーディング部分にクラックの発生がない高い引裂強度を有するディップ成形体の製造方法およびディップ成形体を提供することを目的とする。 An object of the present invention is to provide a method for producing a dip-molded body having a high tear strength without occurrence of cracks in the beading portion, and a dip-molded body.
 本発明者らは、上記課題を解決すべく鋭意研究した結果、合成ポリイソプレンラテックス、加硫剤および加硫促進剤からなるディップ成形用組成物に対して、下記(i)~(iii)の工程をこの順序で実施することにより、上記目的を達成できることを見出し、本発明を完成させるに至った。
(i)トルエンでのSwell Indexが所定値以下になるまで前加硫を実施する
(ii)表面温度が所定温度以上の型を用いて型表面に膜を形成させる
(iii)100℃~140℃で加硫する
As a result of diligent research to solve the above-mentioned problems, the present inventors have found that the following (i) to (iii) are applied to a dip molding composition comprising a synthetic polyisoprene latex, a vulcanizing agent, and a vulcanization accelerator. By carrying out the steps in this order, it has been found that the above object can be achieved, and the present invention has been completed.
(I) Pre-vulcanization is performed until the Swell Index in toluene is below a predetermined value (ii) A film is formed on the surface of the mold using a mold having a surface temperature equal to or higher than a predetermined temperature (iii) 100 ° C. to 140 ° C. Vulcanize with
 即ち、本発明によれば、
(1) 合成ポリイソプレンラテックス、加硫剤および加硫促進剤を含有してなるディップ成形用組成物に対して、トルエンでのSwell Indexが25以下になるまで30℃以上の温度で前加硫を実施する前加硫工程と、前記前加硫工程において前加硫を実施した前記ディップ成形用組成物に、表面温度が60℃以上の型を浸漬して前記型の表面に膜を形成させる膜形成工程と、前記膜を100℃~140℃の加硫温度で加硫する本加硫工程とを含むディップ成形体の製造方法、
(2) 前記前加硫工程において、トルエンでのSwell Indexが17以下となるまで前加硫を行う(1)に記載のディップ成形体の製造方法、
(3) 前記膜形成工程における前記型の表面温度が65℃以上である(1)または(2)に記載のディップ成形体の製造方法、
(4) 前記本加硫工程における加硫温度が110℃~130℃である(1)~(3)の何れかに記載のディップ成形体の製造方法、
(5) (1)~(4)の何れかに記載のディップ成形体の製造方法により得られたディップ成形体
が提供される。
That is, according to the present invention,
(1) For a dip molding composition containing a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator, pre-vulcanize at a temperature of 30 ° C. or higher until the Swell Index in toluene is 25 or lower. A pre-vulcanization step, and a dip-molding composition that has been pre-vulcanized in the pre-vulcanization step, so as to form a film on the surface of the mold by immersing a mold having a surface temperature of 60 ° C. or higher A method for producing a dip-molded body comprising a film forming step and a main vulcanization step of vulcanizing the film at a vulcanization temperature of 100 ° C. to 140 ° C .;
(2) In the pre-vulcanization step, pre-vulcanization is performed until the Swell Index with toluene is 17 or less, The method for producing a dip-formed product according to (1),
(3) The method for producing a dip-molded body according to (1) or (2), wherein the surface temperature of the mold in the film forming step is 65 ° C. or higher.
(4) The method for producing a dip-molded body according to any one of (1) to (3), wherein the vulcanization temperature in the main vulcanization step is 110 ° C. to 130 ° C.
(5) A dip-molded article obtained by the method for producing a dip-molded article according to any one of (1) to (4) is provided.
 本発明によれば、ビーディング部分にクラックの発生がない高い引裂強度を有するディップ成形体の製造方法およびディップ成形体が提供される。 According to the present invention, there are provided a dip-molded body manufacturing method and a dip-molded body having a high tear strength with no occurrence of cracks in the beading portion.
 以下、本発明のディップ成形体の製造方法について説明する。本発明のディップ成形体の製造方法は、合成ポリイソプレンラテックス、加硫剤および加硫促進剤を含有してなるディップ成形用組成物に対して、トルエンでのSwell Indexが25以下になるまで30℃以上の温度で前加硫を実施する前加硫工程と、前記前加硫工程において前加硫を実施した前記ディップ成形用組成物に、表面温度が60℃以上の型を浸漬して前記型の表面に膜を形成させる膜形成工程と、前記膜を100℃~140℃の加硫温度で加硫する本加硫工程とを含む。 Hereinafter, a method for producing the dip-formed body of the present invention will be described. The method for producing a dip-molded article of the present invention is 30 until the Swell Index in toluene is 25 or less for a dip-molding composition containing a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator. A pre-vulcanization step in which pre-vulcanization is performed at a temperature of ℃ or higher; and a dip-molding composition that has been pre-vulcanized in the pre-vulcanization step; A film forming step of forming a film on the surface of the mold, and a main vulcanization step of vulcanizing the film at a vulcanization temperature of 100 ° C. to 140 ° C.
 (ディップ成形用組成物)
 本発明に用いるディップ成形用組成物は、合成ポリイソプレンラテックス、加硫剤および加硫促進剤を含有してなる。
(Dip molding composition)
The dip molding composition used in the present invention comprises a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator.
 (合成ポリイソプレンラテックス)
 ディップ成形用組成物に用いる合成ポリイソプレンラテックスは、イソプレンを重合して得られる合成ポリイソプレンのラテックスである。
(Synthetic polyisoprene latex)
The synthetic polyisoprene latex used in the dip molding composition is a latex of synthetic polyisoprene obtained by polymerizing isoprene.
 合成ポリイソプレンは、イソプレンと共重合可能な他のエチレン性不飽和単量体を共重合したものであってもよい。合成ポリイソプレンのイソプレン単位の含有量は、柔軟で、引張強さに優れるディップ成形体が得られやすいことから、全単量体単位に対して、好ましくは70重量%以上、より好ましくは90重量%以上、さらに好ましくは95重量%以上、特に好ましくは100重量%(イソプレンの単独重合体)である。 The synthetic polyisoprene may be a copolymer of another ethylenically unsaturated monomer copolymerizable with isoprene. The content of isoprene units in the synthetic polyisoprene is flexible, and it is easy to obtain a dip-molded article excellent in tensile strength. Therefore, the content is preferably 70% by weight or more, more preferably 90% by weight based on all monomer units. % Or more, more preferably 95% by weight or more, and particularly preferably 100% by weight (isoprene homopolymer).
 イソプレンと共重合可能な他のエチレン性不飽和単量体としては、例えば、ブタジエン、クロロプレン、1,3-ペンタジエン等のイソプレン以外の共役ジエン単量体;アクリロニトリル、メタクリロニトリル、フマロニトリル、α-クロロアクリロニトリル等のエチレン性不飽和ニトリル単量体;スチレン、アルキルスチレンなどのビニル芳香族単量体;(メタ)アクリル酸メチル、(メタ)アクリル酸エチル、(メタ)アクリル酸ブチル、(メタ)アクリル酸-2-エチルヘキシルなどのエチレン性不飽和カルボン酸エステル単量体;ジビニルベンゼン、ジエチレングリコールジ(メタ)アクリレート、ペンタエリスリトール(メタ)アクリレート等の架橋性単量体;が挙げられる。なお、これらのイソプレンと共重合可能な他のエチレン性不飽和単量体は、1種を単独で用いてもよいし、複数種を併用してもよい。 Examples of other ethylenically unsaturated monomers copolymerizable with isoprene include conjugated diene monomers other than isoprene such as butadiene, chloroprene and 1,3-pentadiene; acrylonitrile, methacrylonitrile, fumaronitrile, α- Ethylenically unsaturated nitrile monomers such as chloroacrylonitrile; vinyl aromatic monomers such as styrene and alkylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (meth) And ethylenically unsaturated carboxylic acid ester monomers such as 2-ethylhexyl acrylate; crosslinkable monomers such as divinylbenzene, diethylene glycol di (meth) acrylate, and pentaerythritol (meth) acrylate. In addition, the other ethylenically unsaturated monomer copolymerizable with these isoprenes may be used individually by 1 type, and may use multiple types together.
 合成ポリイソプレン中のイソプレン単位としては、イソプレンの結合状態により、シス結合単位、トランス結合単位、1,2-ビニル結合単位、3,4-ビニル結合単位の4種類が存在する。 There are four types of isoprene units in the synthetic polyisoprene, which are cis bond units, trans bond units, 1,2-vinyl bond units, and 3,4-vinyl bond units, depending on the bond state of isoprene.
 そして、ディップ成形体の引張強さ向上の観点から、合成ポリイソプレンに含まれるイソプレン単位中のシス結合単位の含有割合は、全イソプレン単位に対して、好ましくは70重量%以上、より好ましくは90重量%以上、特に好ましくは95重量%以上である。 From the viewpoint of improving the tensile strength of the dip-molded product, the content of cis-bond units in the isoprene units contained in the synthetic polyisoprene is preferably 70% by weight or more, more preferably 90%, based on the total isoprene units. % By weight or more, particularly preferably 95% by weight or more.
 合成ポリイソプレンの重量平均分子量は、ゲル・パーミエーション・クロマトグラフィー分析による標準ポリスチレン換算で、10,000~5,000,000、好ましくは500,000~5,000,000、特に好ましくは800,000~3,000,000である。合成ポリイソプレンの重量平均分子量が小さすぎると、ディップ成形体の引張強さが低下する傾向があり、逆に大きすぎると、合成ポリイソプレンのラテックスが製造し難くなる傾向がある。 The weight average molecular weight of the synthetic polyisoprene is 10,000 to 5,000,000, preferably 500,000 to 5,000,000, particularly preferably 800,000 in terms of standard polystyrene by gel permeation chromatography analysis. 000 to 3,000,000. If the weight average molecular weight of the synthetic polyisoprene is too small, the tensile strength of the dip-molded product tends to decrease. Conversely, if it is too large, the synthetic polyisoprene latex tends to be difficult to produce.
 また、合成ポリイソプレンのポリマームーニー粘度〔ML1+4、100℃〕は、50~80、好ましくは60~80、特に好ましくは70~80である。 The polymer Mooney viscosity [ML 1 + 4 , 100 ° C.] of the synthetic polyisoprene is 50 to 80, preferably 60 to 80, particularly preferably 70 to 80.
 また、合成ポリイソプレンラテックス中のラテックス粒子(合成ポリイソプレン粒子)の体積平均粒子径は、好ましくは0.5~10μm、より好ましくは0.5~3μm、特に好ましくは0.5~2μmである。この体積平均粒子径が小さすぎると、ラテックス粘度が高くなりすぎて取り扱い難くなる場合があり、逆に大きすぎると、合成ポリイソプレンラテックスを貯蔵した際に、ラテックス表面に皮膜が生成する場合がある。 The volume average particle diameter of latex particles (synthetic polyisoprene particles) in the synthetic polyisoprene latex is preferably 0.5 to 10 μm, more preferably 0.5 to 3 μm, and particularly preferably 0.5 to 2 μm. . If the volume average particle size is too small, the latex viscosity may become too high and difficult to handle. Conversely, if the volume average particle size is too large, a film may be formed on the latex surface when the synthetic polyisoprene latex is stored. .
 合成ポリイソプレンラテックスの電導度は、1.0mS/cm~2.0mS/cmであることが好ましい。電導度が1.0mS/cm未満の場合は乳化時や濃縮時に凝集物が多量に発生する場合がある。また、電導度が2.0mS/cmを超える場合には、脱溶剤時に発泡が激しくなったり、ディップ成形用組成物を移送する際や配合時に泡立ちが激しく、手袋にピンホールなどの欠陥を残す場合がある。 The electrical conductivity of the synthetic polyisoprene latex is preferably 1.0 mS / cm to 2.0 mS / cm. When the conductivity is less than 1.0 mS / cm, a large amount of aggregates may be generated during emulsification or concentration. Further, when the electrical conductivity exceeds 2.0 mS / cm, foaming becomes severe at the time of solvent removal, foaming is severe at the time of transferring the composition for dip molding or at the time of blending, and defects such as pinholes are left in the glove. There is a case.
 なお、電導度は、METTLER TOLEDO社製導電率計(商品名:SG78-FK2)を使用し、測定温度25℃で測定した値である。 The conductivity is a value measured at a measurement temperature of 25 ° C. using a conductivity meter (trade name: SG78-FK2) manufactured by METLER TOLEDO.
 合成ポリイソプレンラテックスの脂環族炭化水素溶媒および芳香族炭化水素溶媒の合計含有量は500重量ppm以下であることが好ましい。また、脂環族炭化水素溶媒としてはシクロヘキサンが好ましく、芳香族炭化水素溶媒としてはトルエンが好ましい。脂環族炭化水素溶媒および芳香族炭化水素溶媒の合計含有量、特にシクロヘキサンおよびトルエンの合計含有量が多すぎると、ディップ成形用組成物の臭気がきつくなる傾向がある。 The total content of the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent in the synthetic polyisoprene latex is preferably 500 ppm by weight or less. The alicyclic hydrocarbon solvent is preferably cyclohexane, and the aromatic hydrocarbon solvent is preferably toluene. If the total content of the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent, particularly the total content of cyclohexane and toluene, is too large, the odor of the dip-forming composition tends to be tight.
 ここで、上記脂環族炭化水素溶媒および芳香族炭化水素溶媒は、合成ポリイソプレンラテックスを製造する際に、後述する、合成ポリイソプレンを溶解または微分散するための有機溶媒である。 Here, the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent are organic solvents for dissolving or finely dispersing synthetic polyisoprene, which will be described later, when producing synthetic polyisoprene latex.
 なお、脂環族炭化水素溶媒および芳香族炭化水素溶媒の合計含有量の測定は、ガスクロマトグラフィー法など、一般的に使用可能な測定方法で測定することができる。 Note that the total content of the alicyclic hydrocarbon solvent and the aromatic hydrocarbon solvent can be measured by a generally usable measurement method such as a gas chromatography method.
 合成ポリイソプレンラテックスの製造方法としては、例えば、(1)有機溶媒に溶解または微分散した合成ポリイソプレンの溶液または微細懸濁液を、界面活性剤の存在下に、水中で乳化し、必要により有機溶媒を除去して、合成ポリイソプレンラテックスを製造する方法、(2)イソプレン単独または、イソプレンと共重合可能なエチレン性不飽和単量体との混合物を、乳化重合もしくは懸濁重合して、直接、合成ポリイソプレンラテックスを製造する方法、が挙げられるが、イソプレン単位中のシス結合単位の割合が高い合成ポリイソプレンを用いることができ、引張強さに優れるディップ成形体が得られる点から、上記(1)の製造方法が好ましい。 As a method for producing a synthetic polyisoprene latex, for example, (1) a solution or fine suspension of a synthetic polyisoprene dissolved or finely dispersed in an organic solvent is emulsified in water in the presence of a surfactant, and if necessary, A method for producing a synthetic polyisoprene latex by removing an organic solvent, (2) emulsion polymerization or suspension polymerization of isoprene alone or a mixture of ethylenically unsaturated monomers copolymerizable with isoprene, A method of directly producing a synthetic polyisoprene latex is mentioned, but a synthetic polyisoprene having a high ratio of cis bond units in the isoprene unit can be used, and a dip molded article having excellent tensile strength can be obtained. The production method (1) is preferred.
 合成ポリイソプレンは、従来公知の方法、例えばトリアルキルアルミニウム-四塩化チタンからなるチーグラー系重合触媒やn-ブチルリチウム、sec-ブチルリチウムなどのアルキルリチウム重合触媒を用いて、不活性重合溶媒中で、イソプレンを溶液重合して得ることができる。そして、得られた合成ポリイソプレンの重合体溶液を、そのまま用いても良いが、該重合体溶液から固形の合成ポリイソプレンを取り出した後、その固形の合成ポリイソプレンを有機溶媒に溶解して用いることもできる。 Synthetic polyisoprene is produced in an inert polymerization solvent using a conventionally known method, for example, a Ziegler polymerization catalyst composed of trialkylaluminum-titanium tetrachloride or an alkyllithium polymerization catalyst such as n-butyllithium or sec-butyllithium. It can be obtained by solution polymerization of isoprene. The obtained polymer solution of synthetic polyisoprene may be used as it is, but after the solid synthetic polyisoprene is taken out from the polymer solution, the solid synthetic polyisoprene is dissolved in an organic solvent and used. You can also.
 この際、ポリイソプレンを合成した後に、重合体溶液中に残った重合触媒の残渣などの不純物を取り除いてもよい。また、重合中または重合後の溶液に、後述する老化防止剤を添加してもよい。
 また、市販の固形の合成ポリイソプレンを用いてもよい。
At this time, after synthesizing the polyisoprene, impurities such as a residue of the polymerization catalyst remaining in the polymer solution may be removed. Moreover, you may add the anti-aging agent mentioned later to the solution during superposition | polymerization or after superposition | polymerization.
Commercially available solid synthetic polyisoprene may also be used.
 上記(1)の製造方法で用いる有機溶媒としては、例えば、ベンゼン、トルエン、キシレン等の芳香族炭化水素溶媒;シクロペンタン、シクロペンテン、シクロヘキサン、シクロヘキセン等の脂環族炭化水素溶媒;ペンタン、ヘキサン、ヘプタン等の脂肪族炭化水素溶媒;塩化メチレン、クロロホルム、二塩化エチレン等のハロゲン化炭化水素溶媒;等を挙げることができる。これらのうち、芳香族炭化水素溶媒および脂環族炭化水素溶媒が好ましく、シクロヘキサンおよびトルエンが特に好ましい。
 なお、有機溶媒の使用量は、合成ポリイソプレン100重量部に対して、好ましくは2,000重量部以下、より好ましくは20~1,500重量部である。
Examples of the organic solvent used in the production method (1) include aromatic hydrocarbon solvents such as benzene, toluene and xylene; alicyclic hydrocarbon solvents such as cyclopentane, cyclopentene, cyclohexane and cyclohexene; pentane, hexane, And aliphatic hydrocarbon solvents such as heptane; halogenated hydrocarbon solvents such as methylene chloride, chloroform and ethylene dichloride; Of these, aromatic hydrocarbon solvents and alicyclic hydrocarbon solvents are preferred, with cyclohexane and toluene being particularly preferred.
The amount of the organic solvent used is preferably 2,000 parts by weight or less, more preferably 20 to 1,500 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene.
 上記(1)の製造方法で用いる界面活性剤としては、例えば、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンアルキルフェノールエーテル、ポリオキシエチレンアルキルエステル、ポリオキシエチレンソルビタンアルキルエステル等の非イオン性界面活性剤;ラウリン酸、ミリスチン酸、パルミチン酸、オレイン酸、リノレン酸、ロジン酸の如き脂肪酸のナトリウムまたはカリウム塩、ドデシルベンゼンスルホン酸ナトリウムなどのアルキルベンゼンスルホン酸塩、高級アルコール硫酸エステル塩、アルキルスルホコハク酸塩等のアニオン性界面活性剤;アルキルトリメチルアンモニウムクロライド、ジアルキルジメチルアンモニウムクロライド、アルキルベンジルジメチルアンモニウムクロライド等のカチオン性界面活性剤;α,β-不飽和カルボン酸のスルホエステル、α,β-不飽和カルボン酸のサルフェートエステル、スルホアルキルアリールエーテル等の共重合性の界面活性剤;等が挙げられるが、アニオン性界面活性剤が好適であり、ロジン酸ナトリウムおよびドデシルベンゼンスルホン酸ナトリウムが特に好ましい。なお、これらの界面活性剤は、1種を単独で用いてもよいし、2種以上を併用してもよい。 Examples of the surfactant used in the production method of (1) above include nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester; Sodium or potassium salts of fatty acids such as lauric acid, myristic acid, palmitic acid, oleic acid, linolenic acid, rosin acid, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, higher alcohol sulfates, alkyl sulfosuccinates, etc. Anionic surfactants; cationic surfactants such as alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, alkylbenzyldimethylammonium chloride copolymerizable surfactants such as sulfoesters of α, β-unsaturated carboxylic acids, sulfate esters of α, β-unsaturated carboxylic acids, sulfoalkylaryl ethers, and the like. Preferred are sodium rosinate and sodium dodecylbenzenesulfonate. In addition, these surfactants may be used individually by 1 type, and may use 2 or more types together.
 界面活性剤の使用量は、合成ポリイソプレン100重量部に対して、好ましくは0.5~50重量部、より好ましくは0.5~30重量部である。この量が少なすぎると、ラテックスの安定性が劣る傾向にあり、逆に多すぎると、発泡しやすくなり、ディップ成形時に問題が起きる可能性がある。 The amount of the surfactant used is preferably 0.5 to 50 parts by weight, more preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If the amount is too small, the stability of the latex tends to be inferior. On the other hand, if the amount is too large, foaming tends to occur and problems may occur during dip molding.
 上記(1)の製造方法で使用する水の量は、合成ポリイソプレン100重量部に対して、好ましくは50~5,000重量部、より好ましくは100~3,000重量部である。 The amount of water used in the production method (1) is preferably 50 to 5,000 parts by weight, more preferably 100 to 3,000 parts by weight, based on 100 parts by weight of the synthetic polyisoprene.
 使用する水の種類としては、硬水、軟水、イオン交換水、蒸留水、ゼオライトウォーターなどが挙げられる。また、メタノールなどのアルコールに代表される極性溶媒を水と併用してもよい。 Examples of the water used include hard water, soft water, ion exchange water, distilled water, and zeolite water. Moreover, you may use together the polar solvent represented by alcohol, such as methanol, with water.
 合成ポリイソプレンの有機溶媒溶液または微細懸濁液を、界面活性剤の存在下、水中で乳化する装置は、一般に乳化機又は分散機として市販されているものであれば特に限定されず使用できる。そして、界面活性剤の添加方法は、特に限定されず、予め水および/または合成ポリイソプレンの有機溶媒溶液または微細懸濁液に添加しても、乳化操作を行っている最中に、乳化液に添加してもよく、一括添加しても、分割添加してもよい。 An apparatus for emulsifying an organic solvent solution or fine suspension of synthetic polyisoprene in water in the presence of a surfactant can be used without particular limitation as long as it is generally commercially available as an emulsifier or a disperser. The addition method of the surfactant is not particularly limited, and the emulsified liquid may be added during the emulsification operation even if it is added to the organic solvent solution or fine suspension of water and / or synthetic polyisoprene in advance. It may be added in a batch, or may be added all at once or dividedly.
 乳化装置としては、例えば、商品名:ホモジナイザー(IKA社製)、商品名:ポリトロン(キネマティカ社製)、商品名:TKオートホモミキサー(特殊機化工業社製)等のバッチ式乳化機;商品名:TKパイプラインホモミキサー(特殊機化工業社製)、商品名:コロイドミル(神鋼パンテック社製)、商品名:スラッシャー(日本コークス工業社製)、商品名:トリゴナル湿式微粉砕機(三井三池化工機社製)、商品名:キャビトロン(ユーロテック社製)、商品名:マイルダー(太平洋機工社製)、商品名:ファインフローミル(太平洋機工社製)等の連続式乳化機;商品名:マイクロフルイダイザー(みずほ工業社製)、商品名:ナノマイザー(ナノマイザー社製)、商品名:APVガウリン(ガウリン社製)等の高圧乳化機;膜乳化機(冷化工業社製)等の膜乳化機;商品名:バイブロミキサー(冷化工業社製)等の振動式乳化機;商品名:超音波ホモジナイザー(ブランソン社製)等の超音波乳化機;等が挙げられる。なお、乳化装置による乳化操作の条件は、特に限定されず、所望の分散状態になるように、処理温度、処理時間などを適宜選定すれば良い。 Examples of the emulsifier include a batch type emulsifier such as trade name: homogenizer (manufactured by IKA), trade name: polytron (manufactured by Kinematica), trade name: TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), etc. Name: TK Pipeline Homomixer (manufactured by Koki Kogyo Kogyo Co., Ltd.), Product Name: Colloid Mill (made by Shinko Pantech Co., Ltd.), Product Name: Thrasher (manufactured by Nihon Coke Kogyo Co., Ltd.), Product Name: Trigonal Wet Fine Crusher ( Product name: Cavitron (manufactured by Eurotech), product name: Milder (manufactured by Taiheiyo Kiko Co., Ltd.), product name: Fine Flow Mill (manufactured by Taiheiyo Kiko Co., Ltd.), etc. Name: Microfluidizer (manufactured by Mizuho Kogyo Co., Ltd.), trade name: Nanomizer (manufactured by Nanomizer Co., Ltd.), trade name: APV Gaurin (manufactured by Gaulin Co., Ltd.), etc .; Membrane emulsifiers such as an emulsifier (made by Chilling Industries Co., Ltd.); Product name: Vibratory emulsifiers such as Vibro mixer (made by Chilling Industries Co., Ltd.); Machine; and the like. In addition, the conditions of the emulsification operation by the emulsification apparatus are not particularly limited, and the treatment temperature, the treatment time, and the like may be appropriately selected so as to obtain a desired dispersion state.
 上記(1)の方法においては、乳化操作を経て得られた乳化物から、有機溶媒を除去して、合成ポリイソプレンラテックスを得ることが好ましい。乳化物から有機溶媒を除去する方法は、特に限定されず、減圧蒸留、常圧蒸留、水蒸気蒸留、遠心分離等の方法を採用することができる。 In the method (1) above, it is preferable to obtain a synthetic polyisoprene latex by removing the organic solvent from the emulsion obtained through the emulsification operation. The method for removing the organic solvent from the emulsion is not particularly limited, and methods such as vacuum distillation, atmospheric distillation, steam distillation, and centrifugation can be employed.
 また、有機溶媒を除去した後、必要に応じ、合成ポリイソプレンラテックスの固形分濃度を上げるために、減圧蒸留、常圧蒸留、遠心分離、膜濃縮等の方法で濃縮操作を施してもよい。 Further, after removing the organic solvent, if necessary, in order to increase the solid content concentration of the synthetic polyisoprene latex, a concentration operation may be performed by a method such as vacuum distillation, atmospheric distillation, centrifugation, membrane concentration or the like.
 合成ポリイソプレンラテックスの固形分濃度は、好ましくは30~70重量%、より好ましくは40~70重量%である。固形分濃度が低すぎると、合成ポリイソプレンラテックスを貯蔵した際に、合成ポリイソプレン粒子が分離する懸念があり、逆に高すぎると、合成ポリイソプレン粒子同士が凝集して粗大凝集物が発生する場合がある。 The solid content concentration of the synthetic polyisoprene latex is preferably 30 to 70% by weight, more preferably 40 to 70% by weight. If the solid content concentration is too low, there is a concern that the synthetic polyisoprene particles are separated when the synthetic polyisoprene latex is stored. Conversely, if the solid content concentration is too high, the synthetic polyisoprene particles are aggregated to generate coarse aggregates. There is a case.
 また、合成ポリイソプレンラテックスには、ラテックスの分野で通常配合される、pH調整剤、消泡剤、防腐剤、架橋剤、キレート化剤、酸素捕捉剤、分散剤、老化防止剤等の添加剤を配合しても良い。 Synthetic polyisoprene latex is usually added in the latex field, and includes additives such as pH adjusters, antifoaming agents, preservatives, crosslinking agents, chelating agents, oxygen scavengers, dispersants, and anti-aging agents. May be blended.
 pH調整剤としては、例えば、水酸化ナトリウム、水酸化カリウムなどのアルカリ金属の水酸化物;炭酸ナトリウム、炭酸カリウムなどのアルカリ金属の炭酸塩;炭酸水素ナトリウムなどのアルカリ金属の炭酸水素塩;アンモニア;トリメチルアミン、トリエタノールアミンなどの有機アミン化合物;等が挙げられるが、アルカリ金属の水酸化物またはアンモニアが好ましい。 Examples of the pH adjuster include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal hydrogen carbonates such as sodium bicarbonate; ammonia An organic amine compound such as trimethylamine or triethanolamine; an alkali metal hydroxide or ammonia is preferred.
 (加硫剤)
 加硫剤としては、例えば、粉末硫黄、硫黄華、沈降硫黄、コロイド硫黄、表面処理硫黄、不溶性硫黄等の硫黄;塩化硫黄、二塩化硫黄、モルホリン・ジスルフィド、アルキルフェノール・ジスルフィド、N,N'-ジチオ-ビス(ヘキサヒドロ-2H-アゼピノン-2)、含りんポリスルフィド、高分子多硫化物、2-(4'-モルホリノジチオ)ベンゾチアゾール等の硫黄含有化合物等を用いることができる。なかでも、硫黄が好ましく使用できる。これらの加硫剤は、1種を単独で用いてもよいし、2種以上を併用してもよい。
(Vulcanizing agent)
Examples of the vulcanizing agent include powdered sulfur, sulfur white, precipitated sulfur, colloidal sulfur, surface-treated sulfur, insoluble sulfur, and the like; sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, N, N'- Sulfur-containing compounds such as dithio-bis (hexahydro-2H-azepinone-2), phosphorus-containing polysulfide, polymer polysulfide, 2- (4′-morpholinodithio) benzothiazole, and the like can be used. Of these, sulfur is preferably used. These vulcanizing agents may be used alone or in combination of two or more.
 加硫剤の使用量は、特に限定されないが、合成ポリイソプレン100重量部に対して、好ましくは0.1~10重量部、より好ましくは0.2~3重量部である。この量が少なすぎても、多すぎても、ディップ成形体の引張強さが低下する傾向がある。 The amount of the vulcanizing agent is not particularly limited, but is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If the amount is too small or too large, the tensile strength of the dip-molded product tends to decrease.
 (加硫促進剤)
 加硫促進剤としては、ディップ成形において通常用いられるものが使用でき、例えば、ジエチルジチオカルバミン酸、ジブチルジチオカルバミン酸、ジ-2-エチルヘキシルジチオカルバミン酸、ジシクロヘキシルジチオカルバミン酸、ジフェニルジチオカルバミン酸、ジベンジルジチオカルバミン酸などのジチオカルバミン酸類およびそれらの亜鉛塩;2-メルカプトベンゾチアゾール、2-メルカプトベンゾチアゾール亜鉛、2-メルカプトチアゾリン、ジベンゾチアジル・ジスルフィド、2-(2,4-ジニトロフェニルチオ)ベンゾチアゾール、2-(N,N-ジエチルチオ・カルバイルチオ)ベンゾチアゾール、2-(2,6-ジメチル-4-モルホリノチオ)ベンゾチアゾール、2-(4′-モルホリノ・ジチオ)ベンゾチアゾール、4-モルホニリル-2-ベンゾチアジル・ジスルフィド、1,3-ビス(2-ベンゾチアジル・メルカプトメチル)ユリアなどが挙げられるが、ジエチルジチオカルバミン酸亜鉛、2-メルカプトベンゾチアゾール、2-メルカプトベンゾチアゾール亜鉛が好ましい。これらの加硫促進剤は、1種を単独で用いてもよいし、2種以上を併用してもよい。
(Vulcanization accelerator)
As the vulcanization accelerator, those usually used in dip molding can be used. For example, diethyldithiocarbamic acid, dibutyldithiocarbamic acid, di-2-ethylhexyldithiocarbamic acid, dicyclohexyldithiocarbamic acid, diphenyldithiocarbamic acid, dibenzyldithiocarbamic acid, etc. Dithiocarbamic acids and zinc salts thereof; 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc, 2-mercaptothiazoline, dibenzothiazyl disulfide, 2- (2,4-dinitrophenylthio) benzothiazole, 2- (N , N-diethylthiocarbaylthio) benzothiazole, 2- (2,6-dimethyl-4-morpholinothio) benzothiazole, 2- (4′-morpholino dithio) benzothiazo And 4-morpholinyl-2-benzothiazyl disulfide, 1,3-bis (2-benzothiazyl mercaptomethyl) urea, and the like, zinc diethyldithiocarbamate, 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc preferable. These vulcanization accelerators may be used alone or in combination of two or more.
 加硫促進剤の使用量は、合成ポリイソプレン100重量部に対して、好ましくは0.05~5重量部であり、更に好ましくは0.1~2重量部である。この量が少ないとディップ成形体の引張強さが低下する場合がある。また、この量が過大であると、ディップ成形体の伸び、および引張強さが低下する場合がある。 The amount of the vulcanization accelerator used is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If this amount is small, the tensile strength of the dip-molded product may decrease. On the other hand, if this amount is excessive, the elongation and tensile strength of the dip-formed product may be lowered.
 (その他の成分)
 (酸化亜鉛)
 本発明に用いるディップ成形用組成物は、さらに酸化亜鉛を含有することが好ましい。酸化亜鉛の含有量は、特に限定されないが、合成ポリイソプレン100重量部に対して、好ましくは0.1~5重量部、より好ましくは0.2~2重量部である。この量が少なすぎるとディップ成形体の引張強さが低下する傾向があり、逆に多すぎると、ディップ成形用組成物中の合成ポリイソプレン粒子の安定性が低下して粗大な凝集物が発生する場合がある。
(Other ingredients)
(Zinc oxide)
The dip molding composition used in the present invention preferably further contains zinc oxide. The content of zinc oxide is not particularly limited, but is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 2 parts by weight with respect to 100 parts by weight of synthetic polyisoprene. If this amount is too small, the tensile strength of the dip-molded product tends to decrease. On the other hand, if the amount is too large, the stability of the synthetic polyisoprene particles in the dip-molding composition decreases and coarse aggregates are generated. There is a case.
 (分散剤)
 本発明に用いるディップ成形用組成物は、分散剤を必要に応じて含有してもよく、分散剤としては、例えば、ラウリン酸、ミリスチン酸、パルミチン酸、オレイン酸、リノレン酸およびロジン酸などの脂肪酸のナトリウムまたはカリウム塩、ドデシルベンゼンスルホン酸ナトリウムなどのアルキルベンゼンスルホン酸塩、高級アルコール硫酸エステル塩、アルキルスルホコハク酸塩等のアニオン性界面活性剤等が挙げられるが、ドデシルベンゼンスルホン酸ナトリウムが特に好ましい。なお、これらの界面活性剤は、1種を単独で用いてもよいし、2種以上を併用してもよい。
(Dispersant)
The dip molding composition used in the present invention may contain a dispersant as necessary. Examples of the dispersant include lauric acid, myristic acid, palmitic acid, oleic acid, linolenic acid, and rosin acid. Examples include sodium or potassium salts of fatty acids, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, anionic surfactants such as higher alcohol sulfate esters, alkylsulfosuccinates, etc., but sodium dodecylbenzenesulfonate is particularly preferable. . In addition, these surfactants may be used individually by 1 type, and may use 2 or more types together.
 分散剤の使用量は、合成ポリイソプレン100重量部に対して、好ましくは0.01~5重量部であり、更に好ましくは0.05~3重量部である。この量が少ないとディップ成形用組成物の配合安定性が低下したり、前加硫時に凝集物が多くなる場合がある。また、この量が過大であると、ディップ成形用組成物が泡立ちやすくなり、ピンホールが発生しやすくなる場合がある。 The amount of the dispersing agent used is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If this amount is small, the blending stability of the dip-forming composition may be reduced, or aggregates may increase during pre-vulcanization. On the other hand, if this amount is excessive, the dip-forming composition tends to foam and pinholes are likely to occur.
 (配合剤)
 本発明のディップ成形用組成物には、さらに、老化防止剤;カーボンブラック、シリカ、タルク等の補強剤;炭酸カルシウム、クレー等の充填剤;紫外線吸収剤;可塑剤;等の配合剤を必要に応じて配合することができる。
(Combination agent)
The dip molding composition of the present invention further requires a compounding agent such as an anti-aging agent; a reinforcing agent such as carbon black, silica and talc; a filler such as calcium carbonate and clay; an ultraviolet absorber; a plasticizer; It can be blended according to.
 老化防止剤としては、2,6-ジ-4-メチルフェノール、2,6-ジ-t-ブチルフェノール、ブチルヒドロキシアニソール、2,6-ジ-t-ブチル-α-ジメチルアミノ-p-クレゾール、オクタデシル-3-(3,5-ジ-t-ブチル-4-ヒドロキシフェニル)プロピオネート、スチレン化フェノール、2,2'-メチレン-ビス(6-α-メチル-ベンジル-p-クレゾール)、4,4'-メチレンビス(2,6-ジ-t-ブチルフノール)、2,2'-メチレン-ビス(4-メチル-6-t-ブチルフェノール)、アルキル化ビスフェノール、p-クレゾールとジシクロペンタジエンのブチル化反応生成物、などの硫黄原子を含有しないフェノール系老化防止剤;2,2'-チオビス-(4-メチル-6-t-ブチルフェノール)、4,4'-チオビス-(6-t-ブチル-o-クレゾール)、2,6-ジ-t-ブチル-4-(4,6-ビス(オクチルチオ)-1,3,5-トリアジン-2-イルアミノ)フェノールなどのチオビスフェノール系老化防止剤;トリス(ノニルフェニル)ホスファイト、ジフェニルイソデシルホスファイト、テトラフェニルジプロピレングリコール・ジホスファイトなどの亜燐酸エステル系老化防止剤;チオジプロピオン酸ジラウリルなどの硫黄エステル系老化防止剤;フェニル-α-ナフチルアミン、フェニル-β-ナフチルアミン、p-(p-トルエンスルホニルアミド)-ジフェニルアミン、4,4'―(α,α-ジメチルベンジル)ジフェニルアミン、N,N-ジフェニル-p-フェニレンジアミン、N-イソプロピル-N'-フェニル-p-フェニレンジアミン、ブチルアルデヒド-アニリン縮合物などのアミン系老化防止剤;6-エトキシ-2,2,4-トリメチル-1,2-ジヒドロキノリンなどのキノリン系老化防止剤;2,5-ジ-(t-アミル)ハイドロキノンなどのハイドロキノン系老化防止剤;などが挙げられる。これらの老化防止剤は、1種を単独で用いてもよいし、または2種以上を併用してもよい。 Antiaging agents include 2,6-di-4-methylphenol, 2,6-di-t-butylphenol, butylhydroxyanisole, 2,6-di-t-butyl-α-dimethylamino-p-cresol, Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, styrenated phenol, 2,2′-methylene-bis (6-α-methyl-benzyl-p-cresol), 4, Butylation of 4'-methylenebis (2,6-di-tert-butylphenol), 2,2'-methylene-bis (4-methyl-6-tert-butylphenol), alkylated bisphenol, p-cresol and dicyclopentadiene Phenol-based antioxidants containing no sulfur atom such as reaction products; 2,2′-thiobis- (4-methyl-6-t-butylphenol) 4,4′-thiobis- (6-tert-butyl-o-cresol), 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3,5-triazine-2 -Thiobisphenol-based antioxidants such as ylamino) phenol; phosphite-based antioxidants such as tris (nonylphenyl) phosphite, diphenylisodecyl phosphite, tetraphenyldipropylene glycol diphosphite; dilauryl thiodipropionate, etc. Sulfur ester anti-aging agents of: phenyl-α-naphthylamine, phenyl-β-naphthylamine, p- (p-toluenesulfonylamido) -diphenylamine, 4,4 ′-(α, α-dimethylbenzyl) diphenylamine, N, N -Diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl- -Amine-based antioxidants such as phenylenediamine and butyraldehyde-aniline condensates; Quinoline-based antioxidants such as 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline; 2,5-di- And hydroquinone anti-aging agents such as (t-amyl) hydroquinone. These anti-aging agents may be used alone or in combination of two or more.
 老化防止剤の使用量は、合成ポリイソプレン100重量部に対して、好ましくは0.05~10重量部、より好ましくは0.1~5重量部である。この量が少なすぎると、合成ポリイソプレンが劣化する場合がある。また、この量が多すぎると、ディップ成形体の引張強さが低下する場合がある。 The amount of the antiaging agent used is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the synthetic polyisoprene. If this amount is too small, the synthetic polyisoprene may deteriorate. Moreover, when there is too much this quantity, the tensile strength of a dip molded object may fall.
 ディップ成形用組成物の調製方法は、特に限定されない。当該調整方法としては、ボールミル、ニーダー、ディスパー等の分散機を用いて、合成ポリイソプレンのラテックスに、加硫剤、加硫促進剤、酸化亜鉛、上記の分散剤およびジアルキルジチオカルバミン酸類の一価の塩、並びに必要に応じて配合される老化防止剤などのその他の配合剤を混合する方法や、予め上記の分散機を用いて、合成ポリイソプレンのラテックス以外の所望の配合成分の水性分散液を調製した後、該水性分散液を合成ポリイソプレンのラテックスに混合する方法などが挙げられる。また、合成ポリイソプレンのラテックスに前記の分散剤およびジアルキルジチオカルバミン酸の一価の塩を予め混合した後、加硫剤、加硫促進剤、および老化防止剤などのその他の配合剤、を添加することもできる。
 ディップ成形用組成物のpHは、7以上であることが好ましく、pH8~12の範囲であることがより好ましい。
 また、ディップ成形用組成物の固形分濃度は、15~65重量%の範囲にあることが好ましい。
The method for preparing the dip molding composition is not particularly limited. As the adjustment method, using a dispersing machine such as a ball mill, a kneader, or a disper, a latex of synthetic polyisoprene is added to a vulcanizing agent, a vulcanization accelerator, zinc oxide, the above-described dispersing agent, and a monovalent dialkyldithiocarbamic acid. A method of mixing a salt and other compounding agents such as an anti-aging agent compounded as necessary, or an aqueous dispersion of a desired compounding component other than a synthetic polyisoprene latex using the above-described disperser in advance. Examples thereof include a method of mixing the aqueous dispersion with a synthetic polyisoprene latex after the preparation. In addition, the above-mentioned dispersant and a monovalent salt of dialkyldithiocarbamic acid are mixed in advance with the latex of synthetic polyisoprene, and then other compounding agents such as a vulcanizing agent, a vulcanization accelerator, and an anti-aging agent are added. You can also.
The pH of the dip molding composition is preferably 7 or more, more preferably in the range of pH 8-12.
The solid content concentration of the dip molding composition is preferably in the range of 15 to 65% by weight.
 (前加硫工程)
 本発明のディップ成形体の製造方法は、ディップ成形用組成物をディップ成形に供する前に、熟成(前加硫ともいう。)させる前加硫工程を含む。本発明の前加硫工程では、合成ポリイソプレン重合体、加硫剤および加硫促進剤を含有してなるディップ成形用組成物に対して、トルエンでのSwell Indexが25以下、好ましくは17以下になるまで30℃以上の温度で前加硫を実施する。前加硫を実施した後のSwell Indexが大きすぎると、得られるディップ成形体の引裂強度が低下する。
(Pre-curing process)
The method for producing a dip-molded product of the present invention includes a pre-vulcanization step of aging (also referred to as pre-vulcanization) before subjecting the dip-molding composition to dip molding. In the pre-vulcanization step of the present invention, the Swell Index in toluene is 25 or less, preferably 17 or less, for a dip-forming composition containing a synthetic polyisoprene polymer, a vulcanizing agent and a vulcanization accelerator. Pre-vulcanization is performed at a temperature of 30 ° C. or higher until If the Swell Index after pre-vulcanization is too large, the tear strength of the resulting dip-molded product will be reduced.
 前加硫する時間は、特に限定されず、前加硫温度にも依存するが、好ましくは1~14日間であり、更に好ましくは1~7日間である。この時間が短すぎても長すぎても得られるディップ成形体の引張強さが低下する傾向にある。 The pre-curing time is not particularly limited and depends on the pre-curing temperature, but is preferably 1 to 14 days, and more preferably 1 to 7 days. If this time is too short or too long, the tensile strength of the resulting dip-formed product tends to decrease.
 そして、前加硫した後、ディップ成形に供されるまで、好ましくは10℃~30℃の温度で貯蔵することが好ましい。高温のまま貯蔵すると、得られるディップ成形体の引張強さが低下する傾向にある。 Then, after pre-vulcanization, it is preferably stored at a temperature of 10 ° C. to 30 ° C. until it is used for dip molding. When stored at a high temperature, the tensile strength of the resulting dip-molded product tends to decrease.
 (膜形成工程)
 本発明のディップ成形体の製造方法は、前加硫工程において前加硫を実施したディップ成形用組成物をディップ成形する膜形成工程を含む。膜形成工程では、表面温度が60℃以上、好ましくは65℃以上の型を浸漬して前記型の表面に膜を形成させる。
(Film formation process)
The method for producing a dip-molded article of the present invention includes a film forming step of dip-molding a dip-forming composition that has been pre-vulcanized in the pre-vulcanization step. In the film forming step, a mold having a surface temperature of 60 ° C. or higher, preferably 65 ° C. or higher is dipped to form a film on the surface of the mold.
 ここで、ディップ成形は、ディップ成形用組成物に型を浸漬し、型の表面に当該組成物を沈着させ、次に型を当該組成物から引き上げ、その後、型の表面に沈着した当該組成物を乾燥させる方法である。 Here, in the dip molding, the mold is immersed in the dip molding composition, the composition is deposited on the surface of the mold, the mold is then lifted from the composition, and then the composition is deposited on the surface of the mold. Is a method of drying.
 本発明においては、ディップ成形用組成物に浸漬される前の型の表面温度を60℃以上、好ましくは65℃以上に予熱する。表面温度が低すぎると、得られたディップ成形体を手袋としたときにビーディング部にクラックが発生する虞がある。 In the present invention, the surface temperature of the mold before being immersed in the dip molding composition is preheated to 60 ° C. or higher, preferably 65 ° C. or higher. If the surface temperature is too low, cracks may occur in the beading part when the obtained dip-formed product is used as a glove.
 また、型をディップ成形用組成物に浸漬する前、または、型をディップ成形用組成物から引き上げた後、必要に応じて凝固剤を使用することができる。 Also, a coagulant can be used as necessary before the mold is dipped in the dip molding composition or after the mold is lifted from the dip molding composition.
 凝固剤の使用方法の具体例としては、ディップ成形用組成物に浸漬する前の型を凝固剤の溶液に浸漬して型に凝固剤を付着させる方法(アノード凝着浸漬法)、ディップ成形用組成物を沈着させた型を凝固剤溶液に浸漬する方法(ティーグ凝着浸漬法)などがあるが、厚みムラの少ないディップ成形体が得られる点で、アノード凝着浸漬法が好ましい。 Specific examples of the method of using the coagulant include a method in which a mold before dipping in a dip molding composition is immersed in a coagulant solution to attach the coagulant to the mold (anode coagulation dipping method), for dip molding Although there is a method of immersing the mold on which the composition is deposited in a coagulant solution (Teag adhesion dipping method), the anode adhesion dipping method is preferred in that a dip-formed product with little thickness unevenness can be obtained.
 凝固剤の具体例としては、塩化バリウム、塩化カルシウム、塩化マグネシウム、塩化亜鉛、塩化アルミニウムなどのハロゲン化金属;硝酸バリウム、硝酸カルシウム、硝酸亜鉛などの硝酸塩;酢酸バリウム、酢酸カルシウム、酢酸亜鉛など酢酸塩;硫酸カルシウム、硫酸マグネシウム、硫酸アルミニウムなどの硫酸塩;などの水溶性多価金属塩である。なかでも、カルシウム塩が好ましく、硝酸カルシウムがより好ましい。
 これらの水溶性多価金属塩は、1種を単独で用いてもよいし、2種以上を併用してもよい。
Specific examples of coagulants 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; water-soluble polyvalent metal salts such as calcium sulfate, magnesium sulfate, and sulfates such as aluminum sulfate; Of these, calcium salts are preferable, and calcium nitrate is more preferable.
These water-soluble polyvalent metal salts may be used alone or in combination of two or more.
 凝固剤は、好ましくは水溶液の状態で使用する。この水溶液は、さらにメチルアルコール、エチルアルコールなどの水溶性有機溶媒やノニオン性界面活性剤を含有していても良い。凝固剤の濃度は、水溶性多価金属塩の種類によっても異なるが、好ましくは5~50重量%、より好ましくは10~30重量%である。 The coagulant is preferably used in the form of an aqueous solution. This aqueous solution may further contain a water-soluble organic solvent such as methyl alcohol or ethyl alcohol, or a nonionic surfactant. The concentration of the coagulant varies depending on the type of the water-soluble polyvalent metal salt, but is preferably 5 to 50% by weight, more preferably 10 to 30% by weight.
 型をディップ成形用組成物から引き上げた後、通常、加熱して型上に形成された沈着物(膜)を乾燥させる。乾燥条件は適宜選択すれば良い。 After the mold is lifted from the dip molding composition, the deposit (film) formed on the mold is usually dried by heating. What is necessary is just to select drying conditions suitably.
 (本加硫工程)
 本発明のディップ成形体の製造方法は、型上に形成された沈着物(膜)を加熱することにより加硫する本加硫工程を含む。本加硫工程では、膜を100℃~140℃、好ましくは110℃~130℃の加硫温度で加硫する。加硫温度が高すぎると、得られるディップ成形体の引裂強度が低下する。
(This vulcanization process)
The method for producing a dip-molded article of the present invention includes a main vulcanization step of vulcanizing by heating a deposit (film) formed on a mold. In this vulcanization step, the membrane is vulcanized at a vulcanization temperature of 100 ° C to 140 ° C, preferably 110 ° C to 130 ° C. If the vulcanization temperature is too high, the tear strength of the resulting dip-molded product is lowered.
 また、本加硫工程における加熱時間は、好ましくは10~120分の加熱時間である。加熱の方法は、特に限定されないが、乾燥機中で加熱する方法、オーブンの中で温風で加熱する方法、赤外線を照射して加熱する方法などがある。 The heating time in this vulcanization step is preferably 10 to 120 minutes. The heating method is not particularly limited, and examples thereof include a method of heating in a dryer, a method of heating with warm air in an oven, and a method of heating by irradiating infrared rays.
 また、ディップ成形用組成物を沈着させた型を加熱する前あるいは加熱した後に、水溶性不純物(例えば、余剰の界面活性剤や凝固剤)を除去するために、型を水または温水で洗浄することが好ましい。 Also, before or after heating the mold on which the dip molding composition is deposited, the mold is washed with water or warm water in order to remove water-soluble impurities (for example, excess surfactant or coagulant). It is preferable.
 本加硫工程後のディップ成形体は、型から脱着される。脱着方法の具体例は、手で型から剥がす方法、水圧又は圧縮空気圧力により剥がす方法、などがある。本加硫工程の途中のディップ成形体が脱着に対する十分な強度を有していれば、本加硫工程の途中で脱着し、引き続き、その後の本加硫工程を継続してもよい。 ¡The dip-molded body after this vulcanization process is detached from the mold. Specific examples of the desorption method include a method of peeling from a mold by hand, a method of peeling by water pressure or compressed air pressure, and the like. If the dip-formed body in the middle of the main vulcanization process has sufficient strength against desorption, it may be desorbed in the middle of the main vulcanization process, and then the subsequent main vulcanization process may be continued.
 ディップ成形体が手袋である場合、ディップ成形体同士の接触面における密着を防止し、着脱の際の滑りをよくするために、タルク、炭酸カルシウムなどの無機微粒子または澱粉粒子などの有機微粒子を手袋表面に散布したり、微粒子を含有するエラストマー層を手袋表面に形成したり、手袋の表面層を塩素化したりしてもよい。 When the dip-molded body is a glove, in order to prevent the dip-molded bodies from sticking to each other at the contact surface, and to improve the slippage when attaching and detaching, the glove is made of inorganic fine particles such as talc and calcium carbonate or organic fine particles such as starch particles It may be dispersed on the surface, an elastomer layer containing fine particles may be formed on the surface of the glove, or the surface layer of the glove may be chlorinated.
 以下、実施例により本発明が詳細に説明されるが、本発明はこれらの実施例に限定されない。なお、以下の「%」および「部」は、特に断りのない限り、重量基準である。なお、各種の物性は以下のように測定した。 Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples. The following “%” and “part” are based on weight unless otherwise specified. Various physical properties were measured as follows.
 (Swell Index)
 実施例および比較例において、前加硫工程(熟成)を実施したディップ成形用組成物を約ドライ1gになるようにスポイトでアルミ皿に流延し、室温の真空乾燥機内で3時間減圧乾燥させた。得られた乾燥物を裁断しサンプルとした。
(Swell Index)
In the examples and comparative examples, the dip-forming composition that had been subjected to the pre-vulcanization step (aging) was cast into an aluminum pan with a dropper so that the amount was about 1 g dry, and was dried under reduced pressure in a vacuum dryer at room temperature for 3 hours. It was. The obtained dried product was cut into a sample.
 80メッシュ金網内にこのサンプルを精秤して(この重量をAとする)入れ、トルエン100mLを注入して24時間静置した。24時間後に80メッシュ金網を取出し、余分なトルエンを除去した後、直ちに膨潤したサンプルを金網ごと精秤した(この重量をBとする)。 The sample was precisely weighed in an 80-mesh wire mesh (this weight is A), and 100 mL of toluene was injected and allowed to stand for 24 hours. After 24 hours, the 80-mesh wire mesh was taken out, excess toluene was removed, and the swollen sample was immediately weighed together with the wire mesh (this weight is designated as B).
 そして、ドラフト内でトルエンを揮散させた後、内温が105℃の乾燥機内で2時間乾燥させ、金網ごと重量を測定した(この重量をCとする)。Swell Indexは、下記の式により求めた。
 Swell Index=(B-A)/(C-A)
Then, after evaporating toluene in a fume hood, it was dried in a dryer having an internal temperature of 105 ° C. for 2 hours, and the weight of the entire wire mesh was measured (this weight is C). The Swell Index was determined by the following formula.
Swell Index = (BA) / (CA)
 (ビーディング部のクラック発生状況)
 実施例および比較例の各工程において、ビーディング部におけるクラック発生状況を目視にて判断した。
(The cracking situation of the beading part)
In each step of the example and the comparative example, the crack occurrence state in the beading portion was visually determined.
 (ディップ成形体の引張強さおよび破断直前の伸び)
 ディップ成形体の引張強さは、ASTM D412に基づいて測定した。具体的には、ディップ成形体のフィルムをダンベル(SDMK-100C:ダンベル社製)で打ち抜き、引張強さ測定用試験片を作製した。当該試験片をテンシロン万能試験機(商品名「RTG-1210」、A&D(株)製)で引張速度500mm/minで引っ張り、破断直前の引張強さ(単位:MPa)、破断直前の伸び(単位:%)を測定した。
(Tensile strength of dip-molded body and elongation just before breaking)
The tensile strength of the dip-molded body was measured based on ASTM D412. Specifically, a film of a dip-molded product was punched with a dumbbell (SDMK-100C: manufactured by Dumbbell) to prepare a test piece for measuring tensile strength. The test piece was pulled with a Tensilon universal testing machine (trade name “RTG-1210”, manufactured by A & D Co., Ltd.) at a pulling speed of 500 mm / min, tensile strength immediately before break (unit: MPa), elongation just before break (unit: :%).
 (ディップ成形体の引裂強度)
 ディップ成形体の引裂強度は、ASTM D624-00に基づいて測定した。具体的には、膜厚が約0.2mmのフィルム状のディップ成形体を、23℃相対湿度50%の恒温恒湿室で24時間以上調湿した後、ダンベル(SDMK-1000C:ダンベル社製)で打ち抜き試験片を作製した。当該試験片をテンシロン万能試験機(商品名「RTC-1225A」、(株)オリエンテック製)で引張速度500mm/minで引っ張り、引裂強度(単位:N/mm)を測定した。
(Tear strength of dip molding)
The tear strength of the dip-formed body was measured based on ASTM D624-00. Specifically, a film-shaped dip-formed body having a film thickness of about 0.2 mm is conditioned for 24 hours or more in a constant temperature and humidity chamber at 23 ° C. and 50% relative humidity, and then dumbbell (SDMK-1000C: manufactured by Dumbbell) ) To produce a punched specimen. The test piece was pulled with a Tensilon universal testing machine (trade name “RTC-1225A”, manufactured by Orientec Co., Ltd.) at a tensile speed of 500 mm / min, and the tear strength (unit: N / mm) was measured.
 (実施例1)
 (ディップ成形用組成物)
 合成ポリイソプレンラテックス(商品名「NIPOL ME1150」、日本ゼオン(株)製、イソプレンの単独重合体、固形分濃度61%、平均粒子径1.2μm、重量平均分子量が1,300,000、シス結合単位量98%)を攪拌しながら、合成ポリイソプレン重合体100部に対して、固形分換算で1部になるように濃度10重量%のドデシルベンゼンスルホン酸ソーダを添加した。そして、得られた混合物を攪拌しながら、混合物中の合成ポリイソプレン重合体100部に対して、それぞれ固形分換算で、酸化亜鉛1.5部、硫黄1.5部、老化防止剤(商品名:Wingstay L、グッドイヤー社製)2部、ジエチルジチオカルバミン酸亜鉛0.3部、ジブチルジチオカルバミン酸亜鉛0.5部、2-メルカプトベンゾチアゾール亜鉛0.7部となるように、各配合剤の水分散液を添加した後、水酸化カリウム水溶液を添加して、pHを10.5に調整したディップ成形用組成物を得た。
(Example 1)
(Dip molding composition)
Synthetic polyisoprene latex (trade name “NIPOL ME1150”, manufactured by Nippon Zeon Co., Ltd., homopolymer of isoprene, solid content concentration 61%, average particle size 1.2 μm, weight average molecular weight 1,300,000, cis bond While stirring a unit amount of 98%, sodium dodecylbenzenesulfonate having a concentration of 10% by weight was added to 100 parts of the synthetic polyisoprene polymer so as to be 1 part in terms of solid content. While stirring the resulting mixture, 1.5 parts of zinc oxide, 1.5 parts of sulfur, an antioxidant (trade name) in terms of solid content with respect to 100 parts of the synthetic polyisoprene polymer in the mixture, respectively. : Wingstay L, manufactured by Goodyear) 2 parts, zinc diethyldithiocarbamate 0.3 parts, zinc dibutyldithiocarbamate 0.5 parts, zinc 2-mercaptobenzothiazole zinc 0.7 parts After the liquid was added, an aqueous potassium hydroxide solution was added to obtain a dip molding composition having a pH adjusted to 10.5.
 なお、合成ポリイソプレンラテックスの重量平均分子量は、合成ポリイソプレンラテックスを固形分濃度で0.1重量%となるようにテトラヒドロフランに溶解し、この溶液をゲル・パーミエーション・クロマトグラフィー分析することにより、標準ポリスチレン換算の重量平均分子量として算出した値である。また、シス結合単位量は、合成ポリイソプレンラテックスにメタノールを添加し、凝固することにより得られた凝固物を乾燥した後1H-NMR分析して求められる、合成ポリイソプレン中の全イソプレン単位に対するシス結合単位の割合である。 The weight average molecular weight of the synthetic polyisoprene latex is obtained by dissolving the synthetic polyisoprene latex in tetrahydrofuran to a solid content concentration of 0.1% by weight, and subjecting this solution to gel permeation chromatography analysis. It is a value calculated as a weight average molecular weight in terms of standard polystyrene. In addition, the amount of cis-bond units is determined based on the total isoprene units in the synthetic polyisoprene obtained by 1 H-NMR analysis after drying the coagulated product obtained by adding methanol to the synthetic polyisoprene latex and coagulating it. The ratio of cis bond units.
 (前加硫工程)
 得られたディップ成形用組成物を、30℃に調整された恒温水槽でSwell Indexが13になるまで前加硫(熟成)を行った。
(Pre-curing process)
The obtained dip-forming composition was pre-vulcanized (ripened) in a constant temperature water bath adjusted to 30 ° C. until the Swell Index reached 13.
 (膜形成工程)
 市販のセラミック製手型(株式会社 シンコー社製)を洗浄し、70℃のオーブン内で予備加熱した後、18重量%の硝酸カルシウムおよび0.05重量%のポリオキシエチレンラウリルエーテル(商品名:エマルゲン109P、花王(株)製)からなる凝固剤水溶液に5秒間浸漬し、取り出した。次いで、凝固剤で被覆された手型を70℃のオーブン内で30分以上乾燥した。
(Film formation process)
After washing a commercially available ceramic hand mold (manufactured by Shinko Co., Ltd.) and preheating in an oven at 70 ° C., 18 wt% calcium nitrate and 0.05 wt% polyoxyethylene lauryl ether (trade name: It was immersed in a coagulant aqueous solution made of Emulgen 109P (manufactured by Kao Corporation) for 5 seconds and taken out. Next, the hand mold coated with the coagulant was dried in an oven at 70 ° C. for 30 minutes or more.
 その後、凝固剤で被覆された手型をオーブンから取り出し、ディップ直前の手型の表面温度を65℃としてディップ成形用組成物に10秒間浸漬した。その後、室温で10分間風乾してからビーディングを実施し更に10分間静置した。10分後、ビーディング部のクラック発生状況を目視で判断したが、クラックは見られなかった。
 この手型を50℃の温水中に2分間浸漬した後、同様にビーディング部に亀裂の有無を目視で判断したが、クラックは見られなかった。
Thereafter, the hand mold coated with the coagulant was taken out of the oven, and dipped in the dip molding composition for 10 seconds with the surface temperature of the hand mold just before dipping at 65 ° C. Then, after air-drying for 10 minutes at room temperature, beading was carried out and left still for 10 minutes. Ten minutes later, the occurrence of cracks in the beading portion was visually determined, but no cracks were seen.
After this hand mold was immersed in warm water at 50 ° C. for 2 minutes, the presence or absence of cracks in the beading portion was similarly judged visually, but no cracks were observed.
 (本加硫工程)
 その後、フィルム状の合成ポリイソプレン重合体で被覆された手型をオーブン内に置き、120℃で30分間本加硫を行った。本加硫工程後もビーディング部にクラックは見られなかった。
(This vulcanization process)
Thereafter, a hand mold coated with a film-like synthetic polyisoprene polymer was placed in an oven and subjected to main vulcanization at 120 ° C. for 30 minutes. No cracks were found in the beading part even after this vulcanization step.
 本加硫されたフィルムで被覆された手型を室温まで冷却し、タルクを散布した後、当該フィルムを手型から剥離した。得られたディップ成形体の引張強さ、破断直前の伸びおよび引裂強度の測定結果を表1に示す。 The hand mold covered with the vulcanized film was cooled to room temperature and sprayed with talc, and then the film was peeled from the hand mold. Table 1 shows the measurement results of the tensile strength, elongation just before breakage, and tear strength of the obtained dip-formed body.
 (実施例2)
 前加硫工程においてSwell Indexが22になるまで熟成した以外は、実施例1と同様にディップ成形体を製造し、同様に評価を行った。その結果を表1に示す。なお、ビーディング後、温水浸漬後、加硫後のいずれの段階でもビーディング部にクラックは見られなかった。
(Example 2)
A dip-molded body was produced in the same manner as in Example 1 except that aging was performed until the Swell Index reached 22 in the pre-vulcanization step, and evaluation was performed in the same manner. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
 (実施例3)
 本加硫工程における本加硫の温度を140℃にした以外は、実施例1と同様にして、ディップ成形体を製造し同様に評価を行った。その結果を表1に示す。なお、ビーディング後、温水浸漬後、加硫後のいずれの段階でもビーディング部にクラックは見られなかった。
(Example 3)
A dip-molded body was produced and evaluated in the same manner as in Example 1 except that the temperature of the main vulcanization in the main vulcanization step was 140 ° C. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
 (比較例1)
 前加硫工程においてSwell Indexが27になった時点で熟成を中止した以外は、実施例1と同様にディップ成形体を製造し、同様に評価を行った。その結果を表1に示す。なお、ビーディング後、温水浸漬後、加硫後のいずれの段階でもビーディング部にクラックは見られなかった。
(Comparative Example 1)
A dip-molded body was produced in the same manner as in Example 1 except that the ripening was stopped when the Swell Index reached 27 in the pre-vulcanization step, and evaluation was performed in the same manner. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
 (比較例2)
 膜形成工程において手型の表面温度を50℃としてディップ成形用組成物に浸漬した以外は、実施例1と同様にディップ成形体を製造し、同様に評価を行った。その結果を表1に示す。なお、ビーディング後にビーディング部に多数のクラックが見られた。また、温水浸漬中、加硫後にビーディング部におけるクラックが更に増え、外観の悪いディップ成形体になった。
(Comparative Example 2)
A dip-molded body was produced in the same manner as in Example 1 except that it was immersed in the dip-molding composition at a surface temperature of the hand mold of 50 ° C. in the film forming step, and evaluated in the same manner. The results are shown in Table 1. In addition, many cracks were seen in the beading part after beading. Moreover, during immersion in warm water, cracks in the beading portion further increased after vulcanization, resulting in a dip molded article having a poor appearance.
 (比較例3)
 膜形成工程において手型の表面温度を55℃としてディップ成形用組成物に浸漬した以外は、実施例1と同様にディップ成形体を製造し、同様に評価を行った。その結果を表1に示す。なお、ビーディング後にビーディング部に2箇所クラックが見られた。また、温水浸漬中、加硫後にビーディング部におけるクラックは増えなかったが、外観の悪いディップ成形体になった。
(Comparative Example 3)
A dip-molded body was produced in the same manner as in Example 1 except that the surface temperature of the hand mold was set to 55 ° C. and immersed in the dip-molding composition in the film forming step, and evaluation was performed in the same manner. The results are shown in Table 1. In addition, two places cracks were seen in the beading part after beading. Also, during immersion in warm water, cracks in the beading portion did not increase after vulcanization, but a dip molded article having a poor appearance was obtained.
 (比較例4)
 本加硫工程における本加硫の温度を160℃にした以外は、実施例1と同様にディップ成形体を製造し、同様に評価を行った。その結果を表1に示す。なお、ビーディング後、温水浸漬後、加硫後のいずれの段階でもビーディング部にクラックは見られなかった。
(Comparative Example 4)
A dip-molded body was produced in the same manner as in Example 1 except that the temperature of the main vulcanization in the main vulcanization step was 160 ° C., and the evaluation was performed in the same manner. The results are shown in Table 1. Note that no cracks were observed in the beading part at any stage after beading, immersion in warm water, and after vulcanization.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
 実施例1~3の製造方法では、いずれもビーディング部にクラックは観察されず、ディップ成形体の引裂強度が高いものであった。 In the production methods of Examples 1 to 3, no cracks were observed in the beading part, and the tear strength of the dip-formed product was high.
 一方、Swell Indexが27になった時点で熟成を中止した比較例1においては、ビーディング部にクラックは観察されないものの、ディップ成形体の引裂強度が低いものであった。 On the other hand, in Comparative Example 1 in which the ripening was stopped when the Swell index reached 27, no crack was observed in the beading part, but the tear strength of the dip-formed product was low.
 また、手型の表面温度が低い比較例2および比較例3では、ビーディング部にクラックの程度に差が見られた。手型の表面温度が低くなる程、亀裂が増える傾向が見えた。
 更に、加硫温度を高くした比較例4では、ビーディング部にクラックは観察されないものの、ディップ成形体の引張強さおよび引裂強度が低いものであった。
Further, in Comparative Example 2 and Comparative Example 3 where the surface temperature of the hand mold was low, a difference was observed in the degree of cracks in the beading part. As the surface temperature of the hand mold decreased, the cracks tended to increase.
Furthermore, in Comparative Example 4 in which the vulcanization temperature was increased, no crack was observed in the beading portion, but the tensile strength and tear strength of the dip-formed product were low.
 本発明のディップ成形体の製造方法で得られたディップ成形体は、ビーディング部にクラックがなく、高い引裂強度を有する。このため、手術用、診察用、家庭用、農業用、漁業用および工業用の手袋;指サックなどに好適である。 The dip molded product obtained by the dip molded product manufacturing method of the present invention has no cracks in the beading portion and has a high tear strength. For this reason, it is suitable for surgical gloves, diagnostic gloves, household gloves, agricultural gloves, fishery gloves, and industrial gloves;

Claims (5)

  1.  合成ポリイソプレンラテックス、加硫剤および加硫促進剤を含有してなるディップ成形用組成物に対して、トルエンでのSwell Indexが25以下になるまで30℃以上の温度で前加硫を実施する前加硫工程と、
     前記前加硫工程において前加硫を実施した前記ディップ成形用組成物に、表面温度が60℃以上の型を浸漬して前記型の表面に膜を形成させる膜形成工程と、
     前記膜を100℃~140℃の加硫温度で加硫する本加硫工程と
    を含むディップ成形体の製造方法。
    A dip molding composition containing a synthetic polyisoprene latex, a vulcanizing agent and a vulcanization accelerator is pre-vulcanized at a temperature of 30 ° C. or higher until the Swell Index in toluene is 25 or lower. A pre-vulcanization process;
    A film forming step of immersing a mold having a surface temperature of 60 ° C. or higher to form a film on the surface of the mold in the dip molding composition that has been pre-vulcanized in the pre-vulcanization process;
    And a main vulcanization step of vulcanizing the membrane at a vulcanization temperature of 100 ° C. to 140 ° C.
  2.  前記前加硫工程において、トルエンでのSwell Indexが17以下となるまで前加硫を行う請求項1に記載のディップ成形体の製造方法。 The method for producing a dip-formed body according to claim 1, wherein in the pre-vulcanization step, pre-vulcanization is performed until the Swell index with toluene becomes 17 or less.
  3.  前記膜形成工程における前記型の表面温度が65℃以上である請求項1または2に記載のディップ成形体の製造方法。 The method for producing a dip-formed body according to claim 1 or 2, wherein the surface temperature of the mold in the film forming step is 65 ° C or higher.
  4.  前記本加硫工程における加硫温度が110℃~130℃である請求項1~3の何れかに記載のディップ成形体の製造方法。 The method for producing a dip-formed body according to any one of claims 1 to 3, wherein a vulcanization temperature in the main vulcanization step is 110 ° C to 130 ° C.
  5.  請求項1~4の何れかに記載のディップ成形体の製造方法により得られたディップ成形体。 A dip-molded product obtained by the method for producing a dip-molded product according to any one of claims 1 to 4.
PCT/JP2015/075182 2014-09-26 2015-09-04 Method for producing dip-molded article, and dip-molded article WO2016047418A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2016550085A JP6572902B2 (en) 2014-09-26 2015-09-04 Method for producing dip-molded body
SG11201701075UA SG11201701075UA (en) 2014-09-26 2015-09-04 Method for producing dip-formed article, and dip-formed article

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014196443 2014-09-26
JP2014-196443 2014-09-26

Publications (1)

Publication Number Publication Date
WO2016047418A1 true WO2016047418A1 (en) 2016-03-31

Family

ID=55580946

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/075182 WO2016047418A1 (en) 2014-09-26 2015-09-04 Method for producing dip-molded article, and dip-molded article

Country Status (4)

Country Link
JP (1) JP6572902B2 (en)
SG (1) SG11201701075UA (en)
TW (1) TW201615717A (en)
WO (1) WO2016047418A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019159779A1 (en) * 2018-02-16 2019-08-22 日本ゼオン株式会社 Production method for dip-molded article
WO2024070750A1 (en) * 2022-09-26 2024-04-04 住友精化株式会社 Method for producing dip-formed object, and dip-formed object

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113858514B (en) * 2021-09-13 2024-05-14 泗阳杰盛医疗科技有限公司 Production method of nitrile latex gloves with stable performance

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05202200A (en) * 1991-11-12 1993-08-10 Sumitomo Rubber Ind Ltd Latex rubber product and its production
WO2005095508A1 (en) * 2004-03-31 2005-10-13 Zeon Corporation Composition for dip forming and molding obtained by dip forming
JP2009531509A (en) * 2006-03-31 2009-09-03 エルアールシー プロデュクトス リミテド Polyisoprene condom
JP2012062487A (en) * 2011-12-27 2012-03-29 Nippon Zeon Co Ltd Dip molding composition, and dip molded product

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05202200A (en) * 1991-11-12 1993-08-10 Sumitomo Rubber Ind Ltd Latex rubber product and its production
WO2005095508A1 (en) * 2004-03-31 2005-10-13 Zeon Corporation Composition for dip forming and molding obtained by dip forming
JP2009531509A (en) * 2006-03-31 2009-09-03 エルアールシー プロデュクトス リミテド Polyisoprene condom
JP2012062487A (en) * 2011-12-27 2012-03-29 Nippon Zeon Co Ltd Dip molding composition, and dip molded product

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019159779A1 (en) * 2018-02-16 2019-08-22 日本ゼオン株式会社 Production method for dip-molded article
US20210001521A1 (en) * 2018-02-16 2021-01-07 Zeon Corporation Production method for dip-molded article
JPWO2019159779A1 (en) * 2018-02-16 2021-01-28 日本ゼオン株式会社 Manufacturing method of dip molded product
JP7238879B2 (en) 2018-02-16 2023-03-14 日本ゼオン株式会社 Method for manufacturing dip molded body
WO2024070750A1 (en) * 2022-09-26 2024-04-04 住友精化株式会社 Method for producing dip-formed object, and dip-formed object

Also Published As

Publication number Publication date
TW201615717A (en) 2016-05-01
JP6572902B2 (en) 2019-09-11
SG11201701075UA (en) 2017-03-30
JPWO2016047418A1 (en) 2017-07-06

Similar Documents

Publication Publication Date Title
JP5999103B2 (en) Latex, dip molding composition and dip molding
CN108431118B (en) Latex composition
JP5472286B2 (en) DIP MOLDING COMPOSITION AND DIP MOLDED BODY
JP5488137B2 (en) DIP MOLDING COMPOSITION AND DIP MOLDED BODY
WO2014129547A1 (en) Latex for dip molding use, composition for dip molding use, and dip-molded article
JP6358262B2 (en) DIP MOLDING COMPOSITION AND DIP MOLDED BODY
JP6614159B2 (en) Synthetic polyisoprene latex for dip molding, dip molding composition and dip molded body
WO2014157034A1 (en) Method for producing synthetic isoprene polymer latex
WO2017135144A1 (en) Polymer latex production method
WO2014181714A1 (en) Polyisoprene latex for molding medical supplies, composition for dip molding, medical supplies, and method for molding same
WO2017135146A1 (en) Polymer latex production method
JP2009209229A (en) Composition for dip molding and molded article
JP6572902B2 (en) Method for producing dip-molded body
JP6459564B2 (en) Synthetic isoprene polymer latex for dip molding, dip molding composition and dip molded body
JP6729549B2 (en) Method for producing synthetic isoprene polymer latex for dip molding, method for producing dip molding composition and method for producing dip molded article
JP2016150946A (en) Isoprene polymer latex for dip molding, composition for dip molding and dip molded body
JP2016141691A (en) Composition for dip molding and dip molded body
JP2016160366A (en) Synthetic isoprene polymer latex for dip molding
JP2016160365A (en) Manufacturing method of synthetic isoprene polymer latex, synthetic isoprene polymer latex, composition for dip molding and dip molded body
US20230295385A1 (en) Film molded body
JP2016132761A (en) Method for producing dip molding and dip molding
WO2022172696A1 (en) Method for producing molded body
WO2018088327A1 (en) Synthetic polyisoprene latex

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15843705

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2016550085

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15843705

Country of ref document: EP

Kind code of ref document: A1