WO2019044654A1 - Production method for dip-molded article - Google Patents

Production method for dip-molded article Download PDF

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Publication number
WO2019044654A1
WO2019044654A1 PCT/JP2018/031159 JP2018031159W WO2019044654A1 WO 2019044654 A1 WO2019044654 A1 WO 2019044654A1 JP 2018031159 W JP2018031159 W JP 2018031159W WO 2019044654 A1 WO2019044654 A1 WO 2019044654A1
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Prior art keywords
dip
dip molding
composition
amount
weight
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PCT/JP2018/031159
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French (fr)
Japanese (ja)
Inventor
雅俊 石葉
伊賀　隆志
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日本ゼオン株式会社
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Priority to JP2019539427A priority Critical patent/JP7020487B2/en
Publication of WO2019044654A1 publication Critical patent/WO2019044654A1/en

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Classifications

    • A—HUMAN NECESSITIES
    • A41—WEARING APPAREL
    • A41D—OUTERWEAR; PROTECTIVE GARMENTS; ACCESSORIES
    • A41D19/00—Gloves
    • A41D19/04—Appliances for making gloves; Measuring devices for glove-making
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/02—Shaping 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
    • B29C41/14—Dipping a core
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/42—Nitriles
    • C08F220/44—Acrylonitrile
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L13/00—Compositions of rubbers containing carboxyl groups
    • C08L13/02—Latex

Definitions

  • the present invention relates to a method of manufacturing a dip-formed body, and more particularly, to a method of manufacturing a dip-formed body in which occurrence of coloring such as yellowing is effectively prevented.
  • Patent Document 1 discloses a technique for producing a dip-formed product by dip-forming a dip-forming composition containing a carboxylic acid-modified nitrile copolymer latex using nitrate as a coagulating salt. There is. According to this patent document, a dip-formed body used for surgical gloves, examination gloves, condoms, catheters, industrial gloves, household gloves, health care products, etc. is obtained.
  • the dip-molded product obtained in the technique of Document 1 has a problem of yellowing due to heating at the time of crosslinking, etc., and from the viewpoint of improving product value, suppression of such yellowing has been desired.
  • the present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method for producing a dip-formed body in which the occurrence of coloring such as yellowing is effectively prevented.
  • the inventors of the present invention conducted intensive studies to achieve the above object, and as a result, when dip-forming a composition for dip molding containing a polymer latex, using nitrate as a coagulating salt, The inventors have found that the above object can be achieved by performing dip molding under the condition where the amount of nitrite ion contained in the composition is controlled to 10 ppm by weight or less, and the present invention has been completed.
  • the present invention is a method of producing a dip-formed body by dip-forming a dip-forming composition containing a polymer latex, wherein nitrate is used as the coagulated salt, and the composition for the above-mentioned dip-forming
  • a method for producing a dip-formed product comprises performing dip-forming under the condition that the amount of nitrite ion in the product is controlled to 10 ppm by weight or less.
  • the production method of the present invention it is preferable to perform dip molding under the conditions in which the amount of nitrate ion in the composition for dip molding is controlled to 10 ppm by weight or less. In the production method of the present invention, it is preferable to perform dip molding under the conditions in which the amount of denitrifying bacteria in the composition for dip molding is controlled to 1.0 ⁇ 10 5 (CFU / ml) or less. Further, in the production method of the present invention, the storage temperature at the time of storing the composition for dip molding is preferably in the range of 0 to 18 ° C.
  • the dip molding composition a dip molding composition having a history which has already been used for dip molding using nitrate as a coagulating salt.
  • the solid content concentration of the composition for dip molding is preferably 3.0 to 50% by weight.
  • the polymer constituting the polymer latex is preferably a nitrile rubber.
  • the method for producing a dip-formed article of the present invention is a method for producing a dip-formed article by dip-forming a dip-forming composition containing a polymer latex, wherein nitrate is used as the coagulated salt, and It dip-molds on the conditions which controlled the quantity of the nitrite ion in the composition for shaping
  • the polymer constituting the polymer latex used in the production method of the present invention is not particularly limited in the type of the polymer, and is formed by polymerizing a natural rubber; a monomer containing a conjugated diene such as butadiene or isoprene. Conjugated diene rubbers and the like. Among these, conjugated diene rubbers are preferable.
  • conjugated diene rubbers examples include so-called nitrile rubbers obtained by copolymerizing nitrile group-containing monomers, isoprene rubbers, styrene-butadiene rubbers, chloroprene rubbers and the like. Among these, nitrile rubbers are particularly preferable.
  • the nitrile rubber is not particularly limited, and is obtained by copolymerizing ⁇ , ⁇ -ethylenically unsaturated nitrile monomer and conjugated diene monomer, and other copolymerizable monomer which is optionally used Can be used.
  • the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer is not particularly limited, but an ethylenically unsaturated compound having a nitrile group and having a carbon number of preferably 3 to 18 can be used.
  • examples of such ⁇ , ⁇ -ethylenically unsaturated nitrile monomers include acrylonitrile, methacrylonitrile, halogen-substituted acrylonitrile and the like, and among these, acrylonitrile is particularly preferable.
  • These ⁇ , ⁇ -ethylenically unsaturated nitrile monomers may be used alone or in combination of two or more.
  • the content of the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer unit in the nitrile rubber is preferably 10 to 50% by weight, more preferably 15 to 45% by weight, still more preferably, based on all the monomer units. It is 20 to 40% by weight.
  • the conjugated diene monomer is preferably a conjugated diene monomer having 4 to 6 carbon atoms such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, chloroprene and the like. 1,3-butadiene and isoprene are more preferred, and 1,3-butadiene is particularly preferred.
  • These conjugated diene monomers may be used alone or in combination of two or more.
  • the content of conjugated diene monomer units in the nitrile rubber is preferably 30 to 89% by weight, more preferably 40 to 84% by weight, and still more preferably 50 to 84% by weight, based on all monomer units constituting the nitrile rubber. It is 78% by weight.
  • the nitrile rubber may be obtained by copolymerizing an ethylenically unsaturated acid monomer in addition to the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer and the conjugated diene monomer.
  • the ethylenically unsaturated acid monomer is not particularly limited, and, for example, a carboxyl group-containing ethylenically unsaturated monomer, a sulfonic acid group-containing ethylenically unsaturated monomer, a phosphoric acid group-containing ethylenically unsaturated monomer And the like.
  • the carboxyl group-containing ethylenic unsaturated monomer is not particularly limited.
  • Ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; fumaric acid, maleic acid, itaconic acid, maleic anhydride, anhydride
  • Ethylenically unsaturated polyvalent carboxylic acids such as itaconic acid and anhydrides thereof; Partially esterified products of ethylenically unsaturated polyvalent carboxylic acids such as methyl maleate and methyl itaconate;
  • the sulfonic acid group-containing ethylenic unsaturated monomer is not particularly limited, but vinylsulfonic acid, methylvinylsulfonic acid, styrenesulfonic acid, (meth) allylsulfonic acid, ethyl (meth) acrylic acid-2-sulfonate And 2-acrylamido-2-hydroxypropane sulfonic acid.
  • the phosphoric acid group-containing ethylenic unsaturated monomer is not particularly limited, and is, for example, propyl (meth) acrylate 3-chloro-2-phosphate, ethyl (meth) acrylate 2-phosphate, 3-allyloxy -2-hydroxypropane phosphoric acid and the like.
  • ethylenically unsaturated acid monomers can also be used as an alkali metal salt or ammonium salt, and may be used alone or in combination of two or more.
  • a carboxyl group-containing ethylenically unsaturated monomer is preferable, an ethylenically unsaturated monocarboxylic acid is more preferable, methacrylic acid or acrylic acid is preferable, and methacrylic acid is particularly preferable. preferable.
  • the content ratio of the ethylenically unsaturated acid monomer unit in the nitrile rubber is preferably 1 to 20% by weight, more preferably 1 to 15% by weight, further preferably, with respect to all the monomer units constituting the nitrile rubber. Is 2 to 10% by weight.
  • nitrile rubber in addition to an ⁇ , ⁇ -ethylenically unsaturated nitrile monomer, a conjugated diene monomer, and an ethylenic unsaturated acid monomer which is optionally contained, these single amounts thereof It may be a copolymer of other monomers copolymerizable with the body.
  • copolymerizable monomers include vinyl aromatic monomers such as styrene, alkylstyrene and vinylnaphthalene; fluoroalkyl vinyl ethers such as fluoroethyl vinyl ether; (meth) acrylamide, N-methylol (meth) acrylamide, Ethylenically unsaturated amide monomers such as N, N-dimethylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide; methyl (meth) acrylate, (meth) acrylic acid Ethyl, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, dibutyl maleate, dibutyl fumarate, diethyl maleate (( Meta) acrylic Methoxymethyl
  • the content ratio of the copolymerizable other monomer units in the nitrile rubber is preferably 20% by weight or less, preferably 15% by weight or less, and more preferably, with respect to all the monomer units constituting the nitrile rubber. It is 10% by weight or less.
  • the polymer latex used in the present invention is a conjugated diene rubber such as nitrile rubber
  • the polymer latex used in the present invention emulsion-polymerizes a monomer mixture containing the above-mentioned monomers, for example. It can be obtained by
  • commonly used secondary polymerization materials such as an emulsifier, a polymerization initiator, a molecular weight modifier and the like can be used.
  • the addition method of these polymerization auxiliary materials is not particularly limited, and any method such as initial batch addition method, split addition method, continuous addition method may be used.
  • the emulsifier is not particularly limited.
  • nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester, etc .
  • potassium dodecyl benzene sulfonate dodecyl benzene
  • Anionic emulsifiers such as alkyl benzene sulfonates such as sodium sulfonate, higher alcohol sulfates, alkyl sulfosuccinates
  • cationic emulsifiers such as alkyl trimethyl ammonium chlorides, dialkyl ammonium chlorides and benzyl ammonium chlorides; ⁇ , ⁇ -unsaturated Sulfo esters of carboxylic acids, sulfate esters of ⁇ , ⁇ -unsaturated carboxylic acids, sulfoalkyl aryl ethers
  • a polymerizable emulsifier can be mentioned.
  • anionic emulsifiers are preferable, alkylbenzene sulfonates are more preferable, and potassium dodecylbenzenesulfonate and sodium dodecylbenzenesulfonate are particularly preferable.
  • These emulsifiers can be used alone or in combination of two or more.
  • the amount of the emulsifier used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the monomer mixture.
  • the polymerization initiator is not particularly limited, and for example, inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide and the like; diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-Butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, di- ⁇ - Organic peroxides such as cumyl peroxide, acetyl peroxide, isobutyryl peroxide, benzoyl peroxide; azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, methyl azobisisobutyrate, etc.
  • inorganic peroxides such as sodium persulfate, potassium persul
  • polymerization initiators can be used alone or in combination of two or more.
  • the peroxide initiator is preferably used because it can stably produce a polymer latex and can obtain a dip-molded product having high mechanical strength and soft texture.
  • the amount of the polymerization initiator used is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 2 parts by weight, with respect to 100 parts by weight of the monomer mixture.
  • the peroxide initiator can be used as a redox polymerization initiator in combination with a reducing agent.
  • the reducing agent is not particularly limited, but is a compound containing a metal ion in a reduced state such as ferrous sulfate or cuprous naphthenate; a sulfonic acid compound such as sodium methanesulfonate; an amine compound such as dimethylaniline Carboxylic acid compounds such as sodium ethylenediaminetetraacetate; and the like.
  • These reducing agents can be used alone or in combination of two or more.
  • the amount of the reducing agent used is preferably 3 to 1000 parts by weight with respect to 100 parts by weight of the peroxide.
  • the amount of water used in the emulsion polymerization is preferably 80 to 600 parts by weight, particularly preferably 100 to 200 parts by weight, with respect to 100 parts by weight of all the monomers used.
  • a method of adding monomers for example, a method of adding monomers to be used in a reaction vessel at once, a method of adding continuously or intermittently as polymerization progresses, a part of monomers is added The reaction may be carried out to a specific conversion rate, and then the remaining monomers may be continuously or intermittently added and polymerized, and any method may be employed.
  • the composition of the mixture may be constant or may be changed.
  • each monomer may be added to the reaction container after previously mixing various monomers to be used, or may be separately added to the reaction container.
  • a polymerization auxiliary material such as a chelating agent, a dispersing agent, a pH adjusting agent, an oxygen scavenger, a particle size adjusting agent can be used, and the type and amount thereof are not particularly limited.
  • the polymerization temperature at the time of carrying out the emulsion polymerization is not particularly limited, but is usually 5 to 95 ° C., preferably 30 to 70 ° C.
  • the polymerization time is about 5 to 40 hours.
  • the monomer mixture is emulsion-polymerized, and when reaching a predetermined polymerization conversion rate, the polymerization reaction is stopped by cooling the polymerization system or adding a polymerization terminator.
  • the polymerization conversion rate at the time of terminating the polymerization reaction is preferably 90% by weight or more, more preferably 93% by weight or more.
  • the polymerization terminator is not particularly limited, and examples thereof include hydroxylamine, hydroxyamine sulfate, diethylhydroxylamine, hydroxyamine sulfonic acid and alkali metal salt thereof, sodium dimethyldithiocarbamate, hydroquinone derivative, catechol derivative, and hydroxydimethyl Aromatic hydroxy dithio carboxylic acids, such as benzene thio carboxylic acid, hydroxy diethyl benzene dithio carboxylic acid, hydroxy dibutyl benzene dithio carboxylic acid, and these alkali metal salts etc. are mentioned.
  • the amount of polymerization terminator used is preferably 0.05 to 2 parts by weight with respect to 100 parts by weight of the monomer mixture.
  • a polymer latex can be obtained by removing unreacted monomers and adjusting the solid content concentration and pH.
  • composition for dip molding used in the production method of the present invention contains at least the polymer latex described above, and preferably contains a crosslinking agent in addition to the polymer latex described above.
  • crosslinking agent those commonly used in dip molding can be used, for example, sulfur such as powdered sulfur, sulfur dioxide, precipitated sulfur, colloidal sulfur, surface treated sulfur, insoluble sulfur, etc .; sulfur chloride, sulfur dichloride, morpholine disulfide And sulfur-containing compounds such as alkylphenol disulfide, dibenzothiazyl disulfide, caprolactam disulfide, phosphorus-containing polysulfide, polymer polysulfide, etc .; tetramethylthiuram disulfide, selenium dimethyldithiocarbamate, 2- (4'-morpholinodithio) benzothiazole, etc. Sulfur donating compounds; polyamines such as hexamethylene diamine, triethylene tetramine, tetraethylene pentamine, etc .; These crosslinking agents may be used alone or in combination of two or more.
  • the compounding amount of the crosslinking agent is preferably 0.5 to 10 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the polymer contained in the polymer latex.
  • crosslinking accelerator vulcanization accelerator
  • zinc oxide zinc oxide
  • the crosslinking accelerator (vulcanization accelerator) is not particularly limited, and examples thereof include dithiocarbamates such as diethyldithiocarbamic acid, dibutyldithiocarbamic acid, di-2-ethylhexyl dithiocarbamic acid, dicyclohexyl dithiocarbamic acid, diphenyl dithiocarbamic acid, and dibenzyl dithiocarbamic acid.
  • a cross-linking aid for filler, pH adjuster, thickener, anti-aging agent, dispersant, pigment, filler, softener, etc. May be blended.
  • the solid content concentration of the dip molding composition used in the production method of the present invention is preferably 3.0 to 50% by weight, more preferably 5.0 to 40% by weight. More preferably, it is 7.0 to 40% by weight.
  • the pH of the dip molding composition used in the production method of the present invention is preferably 8.5 to 12, more preferably 9 to 11.
  • the method for producing a dip-formed article of the present invention is a method for producing a dip-formed article by dip-forming a dip-forming composition containing the above-mentioned polymer latex using nitrate as a coagulating salt. At this time, dip molding is performed under the condition that the amount of nitrite ion in the composition for dip molding is controlled to 10 ppm by weight or less and the amount of nitrite ion is controlled to 10 ppm by weight or less. is there.
  • dip molding can be performed, for example, by the following method. That is, the die for dip molding is immersed in an aqueous solution of nitrate as a coagulated salt to make nitrate adhere to the surface of the die for dip molding, and then it is dipped in the composition for dip molding to make the die surface for dip molding It can be carried out by forming a dip molding layer on the
  • nitrate as the coagulated salt examples include barium nitrate, calcium nitrate, zinc nitrate and the like.
  • a nitrate is used as a coagulating salt, but by using such a nitrate, a coagulating property at the time of dip molding and mechanical properties of the resulting dip-formed product are excellent.
  • nitrate as a coagulating salt is usually used in the form of an aqueous solution, a water-soluble organic solvent such as methanol or ethanol or a nonionic surfactant may be further contained in the aqueous solution of nitrate.
  • the concentration of the nitrate in the aqueous solution of the nitrate is usually 5 to 70% by weight, preferably 10 to 50% by weight.
  • the resulting dip-formed product has the problem that coloring such as yellowing occurs, in particular, coloring occurs due to heating at the time of crosslinking, etc. From the viewpoint of improvement, it may be desirable to suppress the occurrence of such coloring.
  • the amount of nitrite ion (NO 2 ⁇ ) in the dip molding composition used for dip molding is controlled to 10 ppm by weight or less, preferably 8 ppm by weight or less It is preferable to control to 6 weight ppm or less more preferably.
  • nitrate as the coagulating salt was nitrate ion (NO 3 ⁇ ) in the composition for dip molding. And nitrate ions are reduced to form nitrite ions (NO 2 ⁇ ), and such nitrite ions cause coloration such as yellowing in the resulting dip-formed product.
  • the influence of such incorporation of nitrate into the dip molding composition is (1) when the dip molding is repeatedly produced using the dip molding composition repeatedly, that is, the dip molding composition In the case where a plurality of dip-formed products are manufactured by repeatedly performing the operation of dipping the dip-forming mold, or (2) after the dip-formed products are manufactured using the composition for dip-forming, dip
  • the dip molding composition is once stored and stored, the dip molding composition is used again to produce a dip molded product, and this becomes remarkable.
  • the present invention by controlling the amount of nitrite ion in the composition for dip molding to 10 ppm by weight or less, even in the above cases (1) and (2), it can be obtained. It is possible to effectively suppress the occurrence of coloring such as yellowing in the dip-formed product.
  • the production is repeated by continuously controlling the amount of nitrite ion in the dip-forming composition to 10 ppm by weight or less. It is possible to effectively suppress the occurrence of coloring such as yellowing in the dip-molded product to be produced.
  • the method for controlling the amount of nitrite ion in the dip molding composition to 10 ppm by weight or less is not particularly limited.
  • the amount of nitrate ion in the dip molding composition Preferably, the amount of denitrifying bacteria is controlled to 10 wt ppm or less, more preferably 8 wt ppm or less, still more preferably 6 wt ppm or less, and the amount of denitrifying bacteria in the composition for dip molding is preferably 1.0 ⁇ 10 10 A method of controlling to 5 (CFU / ml) or less, more preferably 1.0 ⁇ 10 4 (CFU / ml) or less, and further preferably 1.0 ⁇ 10 3 (CFU / ml) or less can be mentioned.
  • the amount of nitrite ion in the composition for dip molding can be controlled to 10 ppm by weight or less.
  • the dip-formed product when a dip-formed product is repeatedly produced using a dip-forming composition repeatedly to obtain a plurality of dip-formed products, the dip-formed product is derived from nitrate as a coagulated salt along with repeated dip-forming. While the amount of nitrate ions increases, or after preparation of the composition for dip molding, denitrifying bacteria are unavoidably taken in from the open air during storage or dip molding, the amounts of these nitrate ions, and By controlling the amount of denitrifying bacteria within the above range, the amount of nitrite ion in the composition for dip molding can be controlled within the above-described predetermined range.
  • the contribution of denitrifying bacteria is mainly due to the reduction of nitrate ions derived from nitrate as coagulated salt to nitrite ions in the composition for dip molding
  • the amount of nitrite ion in the composition for dip molding can be controlled to 10 ppm by weight or less by setting at least one of the amount of nitrate ion and the amount of denitrifying bacteria in the above range. It is a thing.
  • the amount of nitrate ions is larger than the above range, if the amount of denitrifying bacteria is in the above range, the generation of nitrite ions can be effectively suppressed, whereby the amount of nitrite ions can be reduced. If the amount of nitrate ion is in the above range, it is possible to control the formation of nitrite ion, even if the amount of denitrifying bacteria is larger than the above range. It can be effectively suppressed and the amount of nitrite ion can be controlled to 10 ppm by weight or less.
  • denitrifying bacteria is a generic name of various microorganisms which perform the reaction which reduces nitrate ion, and in addition to bacteria, fungi are also mentioned.
  • the denitrifying bacteria include bacteria belonging to the genus Pseudomonas, such as Pseudomonas aeruginosa, Pseudomonas denitrificans, Pseudomonas stazelli, and bacteria belonging to the genus Micrococcus and Paracoccus.
  • the method for controlling the amount of nitrate ion in the dip molding composition to be in the above range is not particularly limited, but after dipping the dip molding die having the nitrate attached thereto in the dip molding composition, When pulling up a dip molding die having a dip molding layer formed on the surface, a method of controlling the liquid containing nitrate, which is dropped from the dip molding die, not to be mixed in the dip molding composition, or in dip molding, A method of shortening the immersion time of the die for dip molding to 2 to 5 seconds may, for example, be mentioned. Specifically, a method of covering the dip tank containing the composition for dip molding when the die for dip molding is pulled up, and the like can be mentioned. However, it is not particularly limited to such a method, and any method can be used as long as the amount of nitrate ion can be controlled within the above range.
  • the method for setting the amount of denitrifying bacteria in the above-mentioned range in the composition for dip molding is not particularly limited, but the environment at the time of storage after producing the composition for dip molding is not exposed to the outside air
  • Method for example, a method for reducing the area of the liquid surface per unit volume of the composition for dip molding), a method for reducing the contact area with the outside air as much as possible
  • the dip-forming composition is stored once, and the stored dip-forming composition is used again.
  • the amount of nitrite ion to 10 ppm by weight or less in the dip-forming composition during storage and after storage, and again when used again, It is possible to effectively suppress the occurrence of coloring such as yellowing in a dip-molded product produced using the dip molding composition after storage.
  • the method for controlling the amount of nitrite ion in the dip molding composition to 10 ppm by weight or less is not particularly limited, but, for example, dip molding as in the case of the above (1)
  • the amount of nitrate ion in the dip-forming composition during storage after dip molding using the composition for the present invention, or after storage, and again when used again is preferably 10 ppm by weight or less
  • the amount of denitrifying bacteria in the dip molding composition is preferably 1.0 ⁇ 10 5 (CFU / ml) or less, more preferably 8 wt ppm or less, and even more preferably 6 wt ppm or less. preferably 1.0 ⁇ 10 4 (CFU / ml ) or less, and a method of more preferably controlled to 1.0 ⁇ 10 3 (CFU / ml ) or less
  • the dip molding composition is subjected to dip molding performed before storage.
  • the nitrate ion derived from the nitrate as the coagulated salt is taken in, whereby the amount of nitrate ion is larger than the above range, and the amount of denitrifying bacteria is 1.0 ⁇ 10 5 (CFU (CFU). If it exceeds / ml, depending on the storage environment, nitrite ions may be generated during storage.
  • the composition for dip molding after storage is used again for dip molding, and even during such storage, the amount of nitrate ion and the amount of denitrifying bacteria It is preferable to control at least one of them in the above range, and thereby it is desirable to suppress the formation of nitrite ion during storage.
  • the amount of nitrate ion and the amount of denitrifying bacteria in this case may be the same as in the above case (1).
  • at least one of the amount of nitrate ion and the amount of denitrifying bacteria is in the above range as in the case of the above (1). It is preferable to control the
  • the temperature during storage is preferably in the range of 0 to 18 ° C.
  • denitrifying bacteria can be inactivated by setting the temperature preferably in the range of 0 to 15 ° C., it is also preferable to adopt a method in which the temperature during storage is in such a range. In this case, in particular, by setting the temperature during storage to the above range, even when the amount of nitrate ion and the amount of denitrifying bacteria in the dip molding composition before storage are both larger than the above ranges.
  • denitrifying bacteria By deactivating denitrifying bacteria, denitrifying bacteria can be reduced (for example, 1.0 ⁇ 10 5 (CFU / ml) or less), whereby the amount of nitrite ion can be reduced. It becomes possible to control to 10 weight ppm or less.
  • the dip molding composition is aged (also referred to as pre-vulcanization) and then aged. It is also good.
  • the time for ripening is not particularly limited, although depending on the temperature for ripening, it is preferably 1 to 14 days, more preferably 1 to 7 days.
  • the ripening temperature is preferably 5 to 40 ° C., more preferably 20 to 40 ° C. Even when the aging is performed, from the viewpoint of suppressing the mixture of denitrifying bacteria, a method of making the environment at the time of aging an environment which does not touch the outside air or a method of minimizing the contact area with the outside air is adopted. It is preferable to do.
  • the temperature at the time of dip molding that is, the temperature of the composition for dip molding at the time of dip molding is preferably in the range of 20 to 40 ° C., more preferably in the range of 22 to 38 ° C. Even if the temperature of the dip molding composition during dip molding is too low or too high, dip molding becomes difficult or the thickness of the dip molding layer formed on the surface of the dip molding die is uneven. It may be
  • the dip-formed layer obtained by dip-forming is usually subjected to heat treatment to be crosslinked.
  • the substrate Before the heat treatment, the substrate may be immersed in water, preferably warm water at 30 to 70 ° C., for about 1 to 60 minutes to remove water-soluble impurities (eg, excess emulsifier, coagulant, etc.).
  • water-soluble impurities eg, excess emulsifier, coagulant, etc.
  • the removal operation of the water-soluble impurities may be carried out after the dip molding layer is heat-treated, but it is preferable to be carried out before the heat treatment in that the water-soluble impurities can be removed more efficiently.
  • Crosslinking of the dip-formed layer is usually carried out by heat treatment at a temperature of 100 to 150 ° C., preferably for 10 to 120 minutes.
  • a heating method a method by external heating with infrared rays or heated air or internal heating with high frequency can be adopted. Among them, external heating by heating air is preferable.
  • a dip-molded body is obtained by removing the crosslinked dip-formed layer from the dip-forming mold.
  • a method of removing it is possible to adopt a method of peeling off from the mold by hand or peeling by water pressure or pressure of compressed air.
  • heat treatment may be further performed at a temperature of 60 to 120 ° C. for 10 to 120 minutes.
  • the dip-formed article obtained by the production method of the present invention is one in which the occurrence of discoloration such as yellowing is effectively suppressed, and is suitable, for example, for gloves, particularly for thin surgical gloves, or gloves
  • gloves particularly for thin surgical gloves, or gloves
  • the composition for dip molding was diluted 1000 times with ion exchange water.
  • the diluted liquid was centrifuged at 110,000 rpm for 2 hours to separate into a solid phase and a liquid phase. Then, the liquid phase is collected from the sample after centrifugation, and this is passed through a 0.2 ⁇ m filter to obtain a transparent liquid, and the obtained transparent liquid is subjected to measurement by anion chromatography, The amount of nitrate ion and the amount of nitrite ion in the dip molding composition were measured.
  • a medium for detecting bacteria (product name "Easicult (R) TTC", manufactured by Orion) is immersed in a carboxyl group-containing nitrile rubber latex or dip molding composition, and the bacteria are cultured at 29 ° C for 48 hours, and then the bacteria are detected. By observing the number of colonies formed in the culture medium, count the number of colonies per 1 mL of carboxyl group-containing nitrile rubber latex or dip molding composition to determine the amount of denitrifying bacteria (unit: CFU / ml) The
  • ⁇ Production Example 1> In a nitrogen-substituted pressure resistant polymerization reactor, 13.5 parts of acrylonitrile, 33.75 parts of 1,3-butadiene and 2.75 parts of methacrylic acid as initial polymerization monomers, and t-dodecyl mercaptan (tDM) as a molecular weight modifier 0.5 parts, 95 parts of deionized water, 1.0 part of sodium dodecylbenzene sulfonate (DBS) as an emulsifier, 0.2 parts of potassium persulfate as a polymerization initiator, and sodium ethylenediaminetetraacetate (EDTA) as a reducing agent 0.1 parts was charged, and the temperature in the polymerization system was raised to 35 ° C.
  • tDM t-dodecyl mercaptan
  • the polymerization conversion rate at the end of the continuous addition was 60%. Thereafter, the polymerization was continued until the polymerization conversion of all the monomers reached 97%, and then the polymerization reaction was stopped by adding 0.1 part of diethylhydroxylamine as a polymerization terminator. Then, after distilling off unreacted monomers from the obtained latex, the solid content concentration and pH were adjusted to obtain a latex of carboxyl group-containing nitrile rubber having a solid content concentration of 45% and pH 8.3. .
  • Reference Example 1 The latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 is adjusted to a solid content concentration of 25% by weight, and then the vulcanizing agent dispersion liquid relative to 100 parts of the solid content in the latex whose solid content concentration is adjusted (A dispersion consisting of 1 part of sulfur, 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water) After mixing 8.66 parts, an appropriate amount of A 5 wt% aqueous potassium hydroxide solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 25 wt% and a pH of 10.0.
  • a dispersion consisting of 1 part of sulfur, 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water After mixing 8.66 parts, an appropriate amount of A 5 wt% aqueous potassium hydroxide solution and deionized water were
  • an aqueous coagulant solution was prepared by mixing 13 parts of calcium nitrate, 0.05 parts of polyoxyethylene octyl phenyl ether as a nonionic emulsifier, and 87 parts of water.
  • dip molding was performed using the composition for dip molding obtained above, and the coagulant
  • the amount of nitrate ion in the composition for dip molding after 50 times of dip molding was measured, and the amount of nitrate ion contained in the composition for dip molding was 0 weight ppm.
  • dip molding was performed using the composition for dip molding obtained above, and the coagulant aqueous solution prepared like the reference example 1. Specifically, 50 dip moldings were performed in the same manner as in Reference Example 1 except that the immersion time of the ceramic mold in the dip molding composition was changed from 2 seconds to 10 seconds.
  • the amount of nitrate ion in the composition for dip molding after 50 times of dip molding was measured, and the amount of nitrate ion contained in the composition for dip molding was 15 weight ppm.
  • dip molding was performed using the composition for dip molding obtained above, and the coagulant aqueous solution prepared like the reference example 1. Specifically, the immersion time of the ceramic mold in the composition for dip molding is changed from 2 seconds to 30 seconds, and a liquid containing nitrate ion (show solution) is not mixed in the composition for dip molding The dip molding was performed 50 times in the same manner as in Reference Example 1 except that no countermeasure (show solution cut) was performed.
  • the amount of nitrate ion in the composition for dip molding after 50 times of dip molding was measured, and the amount of nitrate ion contained in the composition for dip molding was 780 ppm by weight.
  • Example 1 The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex.
  • the number of denitrifying bacteria was measured by the above method and found to be 1.0 ⁇ 10 6 (CFU / ml) or more.
  • the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 25% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex whose solid concentration is adjusted)
  • 8.66 parts an appropriate amount of 5% by weight of hydroxylation
  • a potassium aqueous solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 25% by weight and a pH of 10.0.
  • the obtained dip molding composition is placed in a container so that the amount thereof is 1/2 or more of the volume of the container, and the container is covered to provide an environment free from contact with the outside air, Aging was carried out for 1 day at ° C.
  • the dip molding composition after 50 times of dip molding is covered with an amount of 1/2 or more of the container volume in the same container, so that there is no contact with the open air.
  • the dip molding composition after storage was performed again under the same conditions to obtain a dip molded article for evaluation.
  • each measurement of the nitrite ion amount in the composition for dip molding after obtaining the dip molding for evaluation, the denitrifying bacteria number, and the yellowness degree of the dip molding for evaluation was performed. The results are shown in Table 2.
  • Example 2 Regarding the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1, it is confirmed that the denitrifying bacteria count is 1.0 ⁇ 10 3 (CFU / ml) or less by measuring the denitrifying bacteria count by the above method. Then, the latex was adjusted to a solid concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, zinc oxide 1. A dispersion consisting of 5 parts, 0.5 parts of zinc diethyl carbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), Ion water was added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0. Then, the obtained dip molding composition is placed in a container so that the amount thereof is 1/2 or more of the volume of the container, and the container is covered to provide an environment free from contact with the outside air, Aging was carried out for 1 day at ° C.
  • the dip molding composition after 50 times of dip molding is covered with an amount of 1/2 or more of the container volume in the same container, so that there is no contact with the open air.
  • dip molding is performed again under the same conditions to obtain a dip molded article for evaluation, as in Example 1. Each measurement was performed. The results are shown in Table 2.
  • Example 3 Regarding the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1, it is confirmed that the denitrifying bacteria count is 1.0 ⁇ 10 3 (CFU / ml) or less by measuring the denitrifying bacteria count by the above method. Then, the latex is adjusted to a solid content concentration of 17% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, zinc oxide 1. A dispersion consisting of 5 parts, 0.5 parts of zinc diethyl carbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), Ion water was added to obtain a dip molding composition having a solid concentration of 17% by weight and a pH of 10.0. And, by putting the obtained composition for dip molding into the container so as to be less than a half of the volume of the container, and not covering the lid, an environment having contact with the outside air is obtained. It was aged at 30 ° C. for 1 day.
  • the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered.
  • the dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 30 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
  • Example 4 The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex.
  • the number of denitrifying bacteria was measured by the above method and found to be 1.0 ⁇ 10 6 (CFU / ml) or more.
  • the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex of adjusted solid content concentration)
  • An aqueous solution of potassium and deionized water were added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0.
  • an environment having contact with the outside air is obtained. It was aged at 5 ° C. for 1 day.
  • the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered.
  • the dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 5 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
  • Example 5 The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex.
  • the number of denitrifying bacteria was measured by the above method and found to be 1.0 ⁇ 10 6 (CFU / ml) or more.
  • the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 25% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex whose solid concentration is adjusted)
  • 8.66 parts an appropriate amount of 5% by weight of hydroxylation
  • a potassium aqueous solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 25% by weight and a pH of 10.0.
  • an environment having contact with the outside air is obtained. It was aged at 30 ° C. for 1 day.
  • the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered.
  • the dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 30 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
  • Comparative Example 1 The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex.
  • the number of denitrifying bacteria was measured by the above method and found to be 1.0 ⁇ 10 6 (CFU / ml) or more.
  • the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex of adjusted solid content concentration)
  • An aqueous solution of potassium and deionized water were added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0.
  • an environment having contact with the outside air is obtained. It was aged at 30 ° C. for 1 day.
  • the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered.
  • the dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 30 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
  • Comparative Example 2 The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex.
  • the number of denitrifying bacteria was measured by the above method and found to be 1.0 ⁇ 10 6 (CFU / ml) or more.
  • the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex of adjusted solid content concentration)
  • An aqueous solution of potassium and deionized water were added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0.
  • the obtained dip molding composition is placed in a container so that the amount thereof is 1/2 or more of the volume of the container, and the container is covered to provide an environment free from contact with the outside air, Aging was carried out for 1 day at ° C.
  • the dip molding composition after 50 times of dip molding is covered with an amount of 1/2 or more of the container volume in the same container, so that there is no contact with the open air.
  • dip molding is performed again under the same conditions to obtain a dip molded article for evaluation, as in Example 1. Each measurement was performed. The results are shown in Table 2.
  • Table 1 shows the dip molding conditions of Reference Examples 1 to 3 and the measurement results
  • Table 2 shows the dip molding conditions, storage conditions and measurement results of Examples 1 to 5 and Comparative Examples 1 and 2.
  • the amount of nitrate ion (the amount of nitrate ion after 50 times of dip molding) is 10 ppm by weight or less, or the amount of denitrifying bacteria after storage is 1.0 ⁇ 10 5 ( In Examples 1 to 5 in which the CFU / ml) or less was used, the amount of nitrite ion (the amount of nitrite ion after storage) could be controlled to 10 ppm by weight or less, and the yellowness of the resulting dip-formed product ( YI) was kept low and yellowing was properly prevented.
  • the amount of nitrate ion (the amount of nitrate ion after 50 times of dip molding) is more than 10 ppm by weight, and the denitrifying bacteria after storage is more than 1.0 ⁇ 10 5 (CFU / ml)
  • the degree of yellowness (YI) of the resulting dip-formed product became high, and yellowing occurred.
  • the dip-forming composition was once stored and stored.
  • the dip molding composition was used again to evaluate a dip molded product, but a plurality of dip molded products were repeatedly subjected to dip molding in the storage environment in Examples 1 to 3 and 5. Since it can be considered that the same results as in Examples 1 to 3 and 5 can be obtained even in the case of obtaining the above, as described in (1) above, the dip molding composition is repeatedly used to make a plurality of dips. It can be said that similar results can be obtained even when the molded body is repeatedly manufactured.

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Abstract

Provided is a method for producing a dip-molded article by dip molding of a dip molding composition containing a polymer latex, the method being characterized in that a nitrate is used as a solidification salt, and dip molding is performed under conditions in which the amount of nitrite ions in the dip molding composition is controlled to 10 ppm or less by weight.

Description

ディップ成形体の製造方法Method of manufacturing dip molded body
　本発明は、ディップ成形体の製造方法に係り、さらに詳しくは、黄変などの着色の発生が有効に防止されたディップ成形体の製造方法に関する。 The present invention relates to a method of manufacturing a dip-formed body, and more particularly, to a method of manufacturing a dip-formed body in which occurrence of coloring such as yellowing is effectively prevented.
　重合体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することで、乳首、風船、手袋、バルーン、サック等のディップ成形体を得る技術が知られている。 There is known a technique for obtaining a dip-formed article such as a teat, a balloon, a glove, a balloon, a sack or the like by dip-forming a dip-forming composition containing a polymer latex.
　たとえば、特許文献１では、カルボン酸変性ニトリル系共重合体ラテックスを含有するディップ成形用組成物を、凝固塩として硝酸塩を用いて、ディップ成形することでディップ成形体を製造する技術が開示されている。この特許文献１によれば、手術用手袋、検査手袋、コンドーム、カテーテル、産業用手袋、家庭用手袋または健康管理用品などに用いられるディップ成形体を得るものであるが、その一方で、この特許文献１の技術において得られるディップ成形体は、架橋時の加熱等により黄変してしまうという問題があり、製品価値の向上という観点より、このような黄変の抑制が望まれていた。 For example, Patent Document 1 discloses a technique for producing a dip-formed product by dip-forming a dip-forming composition containing a carboxylic acid-modified nitrile copolymer latex using nitrate as a coagulating salt. There is. According to this patent document, a dip-formed body used for surgical gloves, examination gloves, condoms, catheters, industrial gloves, household gloves, health care products, etc. is obtained. The dip-molded product obtained in the technique of Document 1 has a problem of yellowing due to heating at the time of crosslinking, etc., and from the viewpoint of improving product value, suppression of such yellowing has been desired.
特開２０１６－５３２７４３号公報JP, 2016-532743, A
　本発明は、このような実状に鑑みてなされたものであり、黄変などの着色の発生が有効に防止されたディップ成形体を製造するための方法を提供することを目的とする。 The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a method for producing a dip-formed body in which the occurrence of coloring such as yellowing is effectively prevented.
　本発明者等は、上記目的を達成するために鋭意検討を行った結果、重合体ラテックスを含有するディップ成形用組成物を、凝固塩として硝酸塩を用いて、ディップ成形する際に、ディップ成形用組成物中に含まれる亜硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にてディップ成形を行うことで、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。 The inventors of the present invention conducted intensive studies to achieve the above object, and as a result, when dip-forming a composition for dip molding containing a polymer latex, using nitrate as a coagulating salt, The inventors have found that the above object can be achieved by performing dip molding under the condition where the amount of nitrite ion contained in the composition is controlled to 10 ppm by weight or less, and the present invention has been completed.
　すなわち、本発明によれば、重合体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することで、ディップ成形体を製造する方法であって、凝固塩として硝酸塩を用いるとともに、前記ディップ成形用組成物中における亜硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にてディップ成形を行うことを特徴とするディップ成形体の製造方法が提供される。 That is, according to the present invention, it is a method of producing a dip-formed body by dip-forming a dip-forming composition containing a polymer latex, wherein nitrate is used as the coagulated salt, and the composition for the above-mentioned dip-forming A method for producing a dip-formed product is provided, which comprises performing dip-forming under the condition that the amount of nitrite ion in the product is controlled to 10 ppm by weight or less.
　本発明の製造方法において、前記ディップ成形用組成物中における硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にてディップ成形を行うことが好ましい。
　本発明の製造方法において、前記ディップ成形用組成物中における脱窒菌の量を１．０×１０５（ＣＦＵ／ｍｌ）以下に制御した条件にてディップ成形を行うことが好ましい。
　また、本発明の製造方法において、前記ディップ成形用組成物を保管する際における保管温度を０～１８℃の範囲とすることが好ましい。
　本発明の製造方法においては、前記ディップ成形用組成物として、凝固塩として硝酸塩を用いたディップ成形に既に使用した履歴を有するディップ成形用組成物を用いることができる。
　本発明の製造方法において、前記ディップ成形用組成物の固形分濃度が、３．０～５０重量％であることが好ましい。
　本発明の製造方法において、前記重合体ラテックスを構成する重合体が、ニトリルゴムであることが好ましい。 In the production method of the present invention, it is preferable to perform dip molding under the conditions in which the amount of nitrate ion in the composition for dip molding is controlled to 10 ppm by weight or less.
In the production method of the present invention, it is preferable to perform dip molding under the conditions in which the amount of denitrifying bacteria in the composition for dip molding is controlled to 1.0 × 10 5 (CFU / ml) or less.
Further, in the production method of the present invention, the storage temperature at the time of storing the composition for dip molding is preferably in the range of 0 to 18 ° C.
In the production method of the present invention, it is possible to use, as the dip molding composition, a dip molding composition having a history which has already been used for dip molding using nitrate as a coagulating salt.
In the production method of the present invention, the solid content concentration of the composition for dip molding is preferably 3.0 to 50% by weight.
In the production method of the present invention, the polymer constituting the polymer latex is preferably a nitrile rubber.
　本発明によれば、黄変などの着色の発生が有効に防止されたディップ成形体を製造するための方法を提供することができる。 According to the present invention, it is possible to provide a method for producing a dip-formed body in which the occurrence of coloring such as yellowing is effectively prevented.
　本発明のディップ成形体の製造方法は、重合体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することで、ディップ成形体を製造する方法であって、凝固塩として硝酸塩を用いるとともに、前記ディップ成形用組成物中における亜硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にてディップ成形を行うものである。 The method for producing a dip-formed article of the present invention is a method for producing a dip-formed article by dip-forming a dip-forming composition containing a polymer latex, wherein nitrate is used as the coagulated salt, and It dip-molds on the conditions which controlled the quantity of the nitrite ion in the composition for shaping | molding to 10 weight ppm or less.
＜重合体ラテックス＞
　まず、本発明の製造方法で用いる、重合体ラテックスについて説明する。
　本発明の製造方法で用いる、重合体ラテックスを構成する重合体としては、その重合体の種類に特に限定はなく、天然ゴム；ブタジエンやイソプレンなどの共役ジエンを含む単量体を重合してなる共役ジエン系ゴム；等が挙げられる。これらの中でも、共役ジエン系ゴムが好ましい。共役ジエン系ゴムとしては、ニトリル基含有単量体を共重合してなるいわゆるニトリルゴム、イソプレンゴム、スチレン－ブタジエンゴム、クロロプレンゴム等が挙げられ、これらの中でも、ニトリルゴムが特に好ましい。 <Polymer latex>
First, a polymer latex used in the production method of the present invention will be described.
The polymer constituting the polymer latex used in the production method of the present invention is not particularly limited in the type of the polymer, and is formed by polymerizing a natural rubber; a monomer containing a conjugated diene such as butadiene or isoprene. Conjugated diene rubbers and the like. Among these, conjugated diene rubbers are preferable. Examples of conjugated diene rubbers include so-called nitrile rubbers obtained by copolymerizing nitrile group-containing monomers, isoprene rubbers, styrene-butadiene rubbers, chloroprene rubbers and the like. Among these, nitrile rubbers are particularly preferable.
　ニトリルゴムとしては、特に限定されないが、α，β－エチレン性不飽和ニトリル単量体および共役ジエン単量体、ならびに必要に応じて用いられる共重合可能なその他の単量体を共重合したものを用いることができる。 The nitrile rubber is not particularly limited, and is obtained by copolymerizing α, β-ethylenically unsaturated nitrile monomer and conjugated diene monomer, and other copolymerizable monomer which is optionally used Can be used.
　α，β－エチレン性不飽和ニトリル単量体としては、特に限定されないが、ニトリル基を有し、炭素数が、好ましくは３～１８であるエチレン性不飽和化合物を用いることができる。このようなα，β－エチレン性不飽和ニトリル単量体としては、たとえば、アクリロニトリル、メタクリロニトリル、ハロゲン置換アクリロニトリルなどが挙げられ、これらの中でも、アクリロニトリルが特に好ましい。なお、これらのα，β－エチレン性不飽和ニトリル単量体は、１種単独用いてもよく、２種以上を組み合わせて用いてもよい。 The α, β-ethylenically unsaturated nitrile monomer is not particularly limited, but an ethylenically unsaturated compound having a nitrile group and having a carbon number of preferably 3 to 18 can be used. Examples of such α, β-ethylenically unsaturated nitrile monomers include acrylonitrile, methacrylonitrile, halogen-substituted acrylonitrile and the like, and among these, acrylonitrile is particularly preferable. These α, β-ethylenically unsaturated nitrile monomers may be used alone or in combination of two or more.
　ニトリルゴムにおけるα，β－エチレン性不飽和ニトリル単量体単位の含有割合は、全単量体単位に対して、好ましくは１０～５０重量％、より好ましくは１５～４５重量％、さらに好ましくは２０～４０重量％である。α，β－エチレン性不飽和ニトリル単量体単位の含有割合を上記範囲にすることにより、得られるディップ成形体を引張強度および風合いに優れたものとすることができる。 The content of the α, β-ethylenically unsaturated nitrile monomer unit in the nitrile rubber is preferably 10 to 50% by weight, more preferably 15 to 45% by weight, still more preferably, based on all the monomer units. It is 20 to 40% by weight. By setting the content ratio of the α, β-ethylenically unsaturated nitrile monomer unit to the above range, the resulting dip-formed product can be made excellent in tensile strength and texture.
　共役ジエン単量体としては、１，３－ブタジエン、イソプレン、２，３－ジメチル－１，３－ブタジエン、１，３－ペンタジエン、クロロプレンなどの炭素数４～６の共役ジエン単量体が好ましく、１，３－ブタジエンおよびイソプレンがより好ましく、１，３－ブタジエンが特に好ましい。なお、これらの共役ジエン単量体は、１種単独用いてもよく、２種以上を組み合わせて用いてもよい。 The conjugated diene monomer is preferably a conjugated diene monomer having 4 to 6 carbon atoms such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, chloroprene and the like. 1,3-butadiene and isoprene are more preferred, and 1,3-butadiene is particularly preferred. These conjugated diene monomers may be used alone or in combination of two or more.
　ニトリルゴムにおける共役ジエン単量体単位の含有割合は、ニトリルゴムを構成する全単量体単位に対して、好ましくは３０～８９重量％、より好ましくは４０～８４重量％、さらに好ましくは５０～７８重量％である。共役ジエン単量体単位の含有割合を上記範囲にすることにより、得られるディップ成形体を引張強度および風合いに優れたものとすることができる。 The content of conjugated diene monomer units in the nitrile rubber is preferably 30 to 89% by weight, more preferably 40 to 84% by weight, and still more preferably 50 to 84% by weight, based on all monomer units constituting the nitrile rubber. It is 78% by weight. By making the content rate of a conjugated diene monomer unit into the above-mentioned range, it is possible to make the obtained dip molded body excellent in tensile strength and texture.
　また、ニトリルゴムとしては、α，β－エチレン性不飽和ニトリル単量体および共役ジエン単量体に加えて、エチレン性不飽和酸単量体を共重合してなるものであってもよい。 The nitrile rubber may be obtained by copolymerizing an ethylenically unsaturated acid monomer in addition to the α, β-ethylenically unsaturated nitrile monomer and the conjugated diene monomer.
　エチレン性不飽和酸単量体としては、特に限定されないが、たとえば、カルボキシル基含有エチレン性不飽和単量体、スルホン酸基含有エチレン性不飽和単量体、リン酸基含有エチレン性不飽和単量体などが挙げられる。 The ethylenically unsaturated acid monomer is not particularly limited, and, for example, a carboxyl group-containing ethylenically unsaturated monomer, a sulfonic acid group-containing ethylenically unsaturated monomer, a phosphoric acid group-containing ethylenically unsaturated monomer And the like.
　カルボキシル基含有エチレン性不飽和単量体としては、特に限定されないが、アクリル酸、メタクリル酸、クロトン酸等のエチレン性不飽和モノカルボン酸；フマル酸、マレイン酸、イタコン酸、無水マレイン酸、無水イタコン酸等のエチレン性不飽和多価カルボン酸およびその無水物；マレイン酸メチル、イタコン酸メチル等のエチレン性不飽和多価カルボン酸の部分エステル化物；などが挙げられる。 The carboxyl group-containing ethylenic unsaturated monomer is not particularly limited. Ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; fumaric acid, maleic acid, itaconic acid, maleic anhydride, anhydride Ethylenically unsaturated polyvalent carboxylic acids such as itaconic acid and anhydrides thereof; Partially esterified products of ethylenically unsaturated polyvalent carboxylic acids such as methyl maleate and methyl itaconate;
　スルホン酸基含有エチレン性不飽和単量体としては、特に限定されないが、ビニルスルホン酸、メチルビニルスルホン酸、スチレンスルホン酸、（メタ）アリルスルホン酸、（メタ）アクリル酸－２－スルホン酸エチル、２－アクリルアミド－２－ヒドロキシプロパンスルホン酸などが挙げられる。 The sulfonic acid group-containing ethylenic unsaturated monomer is not particularly limited, but vinylsulfonic acid, methylvinylsulfonic acid, styrenesulfonic acid, (meth) allylsulfonic acid, ethyl (meth) acrylic acid-2-sulfonate And 2-acrylamido-2-hydroxypropane sulfonic acid.
　リン酸基含有エチレン性不飽和単量体としては、特に限定されないが、（メタ）アクリル酸－３－クロロ－２－リン酸プロピル、（メタ）アクリル酸－２－リン酸エチル、３－アリロキシ－２－ヒドロキシプロパンリン酸などが挙げられる。 The phosphoric acid group-containing ethylenic unsaturated monomer is not particularly limited, and is, for example, propyl (meth) acrylate 3-chloro-2-phosphate, ethyl (meth) acrylate 2-phosphate, 3-allyloxy -2-hydroxypropane phosphoric acid and the like.
　これらのエチレン性不飽和酸単量体は、アルカリ金属塩またはアンモニウム塩として用いることもでき、また、１種単独用いてもよく、２種以上を組み合わせて用いてもよい。上記のエチレン性不飽和酸単量体のなかでも、カルボキシル基含有エチレン性不飽和単量体が好ましく、エチレン性不飽和モノカルボン酸がより好ましく、メタクリル酸またはアクリル酸が好ましく、メタクリル酸が特に好ましい。 These ethylenically unsaturated acid monomers can also be used as an alkali metal salt or ammonium salt, and may be used alone or in combination of two or more. Among the above-mentioned ethylenically unsaturated acid monomers, a carboxyl group-containing ethylenically unsaturated monomer is preferable, an ethylenically unsaturated monocarboxylic acid is more preferable, methacrylic acid or acrylic acid is preferable, and methacrylic acid is particularly preferable. preferable.
　ニトリルゴムにおけるエチレン性不飽和酸単量体単位の含有割合は、ニトリルゴムを構成する全単量体単位に対して、好ましくは１～２０重量％、より好ましくは１～１５重量％、さらに好ましくは２～１０重量％である。エチレン性不飽和酸単量体単位の含有割合を上記範囲とすることにより、得られるディップ成形体の引張強度をより高めることができる。 The content ratio of the ethylenically unsaturated acid monomer unit in the nitrile rubber is preferably 1 to 20% by weight, more preferably 1 to 15% by weight, further preferably, with respect to all the monomer units constituting the nitrile rubber. Is 2 to 10% by weight. By making the content rate of an ethylenically unsaturated acid monomer unit into the said range, the tensile strength of the dip molding obtained can be raised more.
　また、ニトリルゴムとしては、α，β－エチレン性不飽和ニトリル単量体、共役ジエン単量体、および必要に応じて含有されるエチレン性不飽和酸単量体に加えて、これらの単量体と共重合可能なその他の単量体を共重合したものであってもよい。 Moreover, as a nitrile rubber, in addition to an α, β-ethylenically unsaturated nitrile monomer, a conjugated diene monomer, and an ethylenic unsaturated acid monomer which is optionally contained, these single amounts thereof It may be a copolymer of other monomers copolymerizable with the body.
　共重合可能なその他の単量体としては、スチレン、アルキルスチレン、ビニルナフタレン等のビニル芳香族単量体；フルオロエチルビニルエーテル等のフルオロアルキルビニルエーテル；（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド、Ｎ，Ｎ－ジメチロール（メタ）アクリルアミド、Ｎ－メトキシメチル（メタ）アクリルアミド、Ｎ－プロポキシメチル（メタ）アクリルアミド等のエチレン性不飽和アミド単量体；（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、（メタ）アクリル酸トリフルオロエチル、（メタ）アクリル酸テトラフルオロプロピル、マレイン酸ジブチル、フマル酸ジブチル、マレイン酸ジエチル、（メタ）アクリル酸メトキシメチル、（メタ）アクリル酸エトキシエチル、（メタ）アクリル酸メトキシエトキシエチル、（メタ）アクリル酸シアノメチル、（メタ）アクリル酸－２－シアノエチル、（メタ）アクリル酸－１－シアノプロピル、（メタ）アクリル酸－２－エチル－６－シアノヘキシル、（メタ）アクリル酸－３－シアノプロピル、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリル酸ヒドロキシプロピル、グリシジル（メタ）アクリレート、ジメチルアミノエチル（メタ）アクリレート等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、ポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（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；などが挙げられる。これらの共重合可能なその他の単量体は、単独で、または２種以上を組み合わせて使用することができる。 Other copolymerizable monomers include vinyl aromatic monomers such as styrene, alkylstyrene and vinylnaphthalene; fluoroalkyl vinyl ethers such as fluoroethyl vinyl ether; (meth) acrylamide, N-methylol (meth) acrylamide, Ethylenically unsaturated amide monomers such as N, N-dimethylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide; methyl (meth) acrylate, (meth) acrylic acid Ethyl, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, dibutyl maleate, dibutyl fumarate, diethyl maleate (( Meta) acrylic Methoxymethyl, ethoxyethyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate, cyanomethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, -1-cyanopropyl (meth) acrylate, (meth) ) 2-Ethyl-6-cyanohexyl acrylate, 3-cyanopropyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl ( Ethylenically unsaturated carboxylic acid ester monomers such as meta) acrylate; divinyl benzene, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylol propane tri (meth) acrylate, pentaerythritol (Meth) crosslinking monomer, such as acrylate, and the like. These other copolymerizable monomers can be used alone or in combination of two or more.
　ニトリルゴムにおける共重合可能なその他の単量体の単位の含有割合は、ニトリルゴムを構成する全単量体単位に対して、好ましくは２０重量％以下、好ましくは１５重量％以下、さらに好ましくは１０重量％以下である。 The content ratio of the copolymerizable other monomer units in the nitrile rubber is preferably 20% by weight or less, preferably 15% by weight or less, and more preferably, with respect to all the monomer units constituting the nitrile rubber. It is 10% by weight or less.
　本発明で用いる重合体ラテックスが、ニトリルゴムなどの共役ジエン系ゴムである場合、本発明で用いる重合体ラテックスは、たとえば、上記の単量体を含有してなる単量体混合物を乳化重合することにより得ることができる。乳化重合に際しては、通常用いられる、乳化剤、重合開始剤、分子量調整剤等の重合副資材を使用することができる。これら重合副資材の添加方法は特に限定されず、初期一括添加法、分割添加法、連続添加法などいずれの方法でもよい。 When the polymer latex used in the present invention is a conjugated diene rubber such as nitrile rubber, the polymer latex used in the present invention emulsion-polymerizes a monomer mixture containing the above-mentioned monomers, for example. It can be obtained by In the case of emulsion polymerization, commonly used secondary polymerization materials such as an emulsifier, a polymerization initiator, a molecular weight modifier and the like can be used. The addition method of these polymerization auxiliary materials is not particularly limited, and any method such as initial batch addition method, split addition method, continuous addition method may be used.
　乳化剤としては、特に限定されないが、たとえば、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乳化剤；ドデシルベンゼンスルホン酸カリウム、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乳化剤；アルキルトリメチルアンモニウムクロライド、ジアルキルアンモニウムクロライド、ベンジルアンモニウムクロライド等のカチオン性乳化剤；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乳化剤などを挙げることができる。なかでも、アニオン性乳化剤が好ましく、アルキルベンゼンスルホン酸塩がより好ましく、ドデシルベンゼンスルホン酸カ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。これらの乳化剤は、単独で、または２種以上を組合せて用いることができる。乳化剤の使用量は、単量体混合物１００重量部に対して、好ましくは０．１～１０重量部である。 The emulsifier is not particularly limited. For example, nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester, etc .; potassium dodecyl benzene sulfonate, dodecyl benzene Anionic emulsifiers such as alkyl benzene sulfonates such as sodium sulfonate, higher alcohol sulfates, alkyl sulfosuccinates; cationic emulsifiers such as alkyl trimethyl ammonium chlorides, dialkyl ammonium chlorides and benzyl ammonium chlorides; α, β-unsaturated Sulfo esters of carboxylic acids, sulfate esters of α, β-unsaturated carboxylic acids, sulfoalkyl aryl ethers, etc. Or the like can be mentioned a polymerizable emulsifier. Among them, anionic emulsifiers are preferable, alkylbenzene sulfonates are more preferable, and potassium dodecylbenzenesulfonate and sodium dodecylbenzenesulfonate are particularly preferable. These emulsifiers can be used alone or in combination of two or more. The amount of the emulsifier used is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the monomer mixture.
　重合開始剤としては、特に限定されないが、たとえば、過硫酸ナトリウム、過硫酸カリウム、過硫酸アンモニウム、過リン酸カリウム、過酸化水素等の無機過酸化物；ジイソプロピルベンゼンハイドロパーオキサイド、クメンハイドロパーオキサイド、ｔ－ブチルハイドロパーオキサイド、１，１，３，３－テトラメチルブチルハイドロパーオキサイド、２，５－ジメチルヘキサン－２，５－ジハイドロパーオキサイド、ジ－ｔ－ブチルパーオキサイド、ジ－α－クミルパーオキサイド、アセチルパーオキサイド、イソブチリルパーオキサイド、ベンゾイルパーオキサイド等の有機過酸化物；アゾビスイソブチロニトリル、アゾビス－２，４－ジメチルバレロニトリル、アゾビスイソ酪酸メチル等のアゾ化合物；などを挙げることができる。これらの重合開始剤は、それぞれ単独で、または２種類以上を組み合わせて使用することができる。
　なお、過酸化物開始剤は、重合体ラテックスを安定して製造することができ、しかも、機械的強度が高く、風合いが柔らかなディップ成形物が得られるので好ましく用いられる。重合開始剤の使用量は、単量体混合物１００重量部に対して、好ましくは０．０１～１０重量部、より好ましくは０．０１～２重量部である。 The polymerization initiator is not particularly limited, and for example, inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide and the like; diisopropylbenzene hydroperoxide, cumene hydroperoxide, t-Butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, di-α- Organic peroxides such as cumyl peroxide, acetyl peroxide, isobutyryl peroxide, benzoyl peroxide; azo compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, methyl azobisisobutyrate, etc. It can be mentioned. These polymerization initiators can be used alone or in combination of two or more.
The peroxide initiator is preferably used because it can stably produce a polymer latex and can obtain a dip-molded product having high mechanical strength and soft texture. The amount of the polymerization initiator used is preferably 0.01 to 10 parts by weight, more preferably 0.01 to 2 parts by weight, with respect to 100 parts by weight of the monomer mixture.
　また、過酸化物開始剤は還元剤との組み合わせで、レドックス系重合開始剤として使用することができる。この還元剤としては、特に限定されないが、硫酸第一鉄、ナフテン酸第一銅等の還元状態にある金属イオンを含有する化合物；メタンスルホン酸ナトリウム等のスルホン酸化合物；ジメチルアニリン等のアミン化合物；エチレンジアミン四酢酸ナトリウム等のカルボン酸化合物；などが挙げられる。これらの還元剤は単独で、または２種以上を組合せて用いることができる。還元剤の使用量は、過酸化物１００重量部に対して３～１０００重量部であることが好ましい。 Also, the peroxide initiator can be used as a redox polymerization initiator in combination with a reducing agent. The reducing agent is not particularly limited, but is a compound containing a metal ion in a reduced state such as ferrous sulfate or cuprous naphthenate; a sulfonic acid compound such as sodium methanesulfonate; an amine compound such as dimethylaniline Carboxylic acid compounds such as sodium ethylenediaminetetraacetate; and the like. These reducing agents can be used alone or in combination of two or more. The amount of the reducing agent used is preferably 3 to 1000 parts by weight with respect to 100 parts by weight of the peroxide.
　乳化重合する際に使用する水の量は、使用する全単量体１００重量部に対して、８０～６００重量部が好ましく、１００～２００重量部が特に好ましい。 The amount of water used in the emulsion polymerization is preferably 80 to 600 parts by weight, particularly preferably 100 to 200 parts by weight, with respect to 100 parts by weight of all the monomers used.
　単量体の添加方法としては、たとえば、反応容器に使用する単量体を一括して添加する方法、重合の進行に従って連続的または断続的に添加する方法、単量体の一部を添加して特定の転化率まで反応させ、その後、残りの単量体を連続的または断続的に添加して重合する方法等が挙げられ、いずれの方法を採用してもよい。単量体を混合して連続的または断続的に添加する場合、混合物の組成は、一定としても、あるいは変化させてもよい。また、各単量体は、使用する各種単量体を予め混合してから反応容器に添加しても、あるいは別々に反応容器に添加してもよい。 As a method of adding monomers, for example, a method of adding monomers to be used in a reaction vessel at once, a method of adding continuously or intermittently as polymerization progresses, a part of monomers is added The reaction may be carried out to a specific conversion rate, and then the remaining monomers may be continuously or intermittently added and polymerized, and any method may be employed. When the monomers are mixed and added continuously or intermittently, the composition of the mixture may be constant or may be changed. In addition, each monomer may be added to the reaction container after previously mixing various monomers to be used, or may be separately added to the reaction container.
　さらに、必要に応じて、キレート剤、分散剤、ｐＨ調整剤、脱酸素剤、粒子径調整剤等の重合副資材を用いることができ、これらは種類、使用量とも特に限定されない。 Furthermore, if necessary, a polymerization auxiliary material such as a chelating agent, a dispersing agent, a pH adjusting agent, an oxygen scavenger, a particle size adjusting agent can be used, and the type and amount thereof are not particularly limited.
　乳化重合を行う際の重合温度は、特に限定されないが、通常、５～９５℃、好ましくは３０～７０℃である。重合時間は５～４０時間程度である。 The polymerization temperature at the time of carrying out the emulsion polymerization is not particularly limited, but is usually 5 to 95 ° C., preferably 30 to 70 ° C. The polymerization time is about 5 to 40 hours.
　以上のように単量体混合物を乳化重合し、所定の重合転化率に達した時点で、重合系を冷却したり、重合停止剤を添加したりして、重合反応を停止する。重合反応を停止する際の重合転化率は、好ましくは９０重量％以上、より好ましくは９３重量％以上である。 As described above, the monomer mixture is emulsion-polymerized, and when reaching a predetermined polymerization conversion rate, the polymerization reaction is stopped by cooling the polymerization system or adding a polymerization terminator. The polymerization conversion rate at the time of terminating the polymerization reaction is preferably 90% by weight or more, more preferably 93% by weight or more.
　重合停止剤としては、特に限定されないが、たとえば、ヒドロキシルアミン、ヒドロキシアミン硫酸塩、ジエチルヒドロキシルアミン、ヒドロキシアミンスルホン酸およびそのアルカリ金属塩、ジメチルジチオカルバミン酸ナトリウム、ハイドロキノン誘導体、カテコール誘導体、ならびに、ヒドロキシジメチルベンゼンチオカルボン酸、ヒドロキシジエチルベンゼンジチオカルボン酸、ヒドロキシジブチルベンゼンジチオカルボン酸などの芳香族ヒドロキシジチオカルボン酸およびこれらのアルカリ金属塩などが挙げられる。重合停止剤の使用量は、単量体混合物１００重量部に対して、好ましくは０．０５～２重量部である。 The polymerization terminator is not particularly limited, and examples thereof include hydroxylamine, hydroxyamine sulfate, diethylhydroxylamine, hydroxyamine sulfonic acid and alkali metal salt thereof, sodium dimethyldithiocarbamate, hydroquinone derivative, catechol derivative, and hydroxydimethyl Aromatic hydroxy dithio carboxylic acids, such as benzene thio carboxylic acid, hydroxy diethyl benzene dithio carboxylic acid, hydroxy dibutyl benzene dithio carboxylic acid, and these alkali metal salts etc. are mentioned. The amount of polymerization terminator used is preferably 0.05 to 2 parts by weight with respect to 100 parts by weight of the monomer mixture.
　重合反応を停止した後、所望により、未反応の単量体を除去し、固形分濃度やｐＨを調整することで、重合体ラテックスを得ることができる。 After termination of the polymerization reaction, if desired, a polymer latex can be obtained by removing unreacted monomers and adjusting the solid content concentration and pH.
＜ディップ成形用組成物＞
　本発明の製造方法で用いるディップ成形用組成物は、上述した重合体ラテックスを少なくとも含有するものであり、上述した重合体ラテックスに加えて、架橋剤を含有するものであることが好ましい。 <Dip Molding Composition>
The composition for dip molding used in the production method of the present invention contains at least the polymer latex described above, and preferably contains a crosslinking agent in addition to the polymer latex described above.
　架橋剤としては、ディップ成形において通常用いられるものが使用でき、たとえば、粉末硫黄、硫黄華、沈降性硫黄、コロイド硫黄、表面処理硫黄、不溶性硫黄などの硫黄；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、ジベンゾチアジルジスルフィド、カプロラクタムジスルフィド、含リンポリスルフィド、高分子多硫化物などの含硫黄化合物；テトラメチルチウラムジスルフィド、ジメチルジチオカルバミン酸セレン、２－（４’－モルホリノジチオ）ベンゾチアゾールなどの硫黄供与性化合物；ヘキサメチレンジアミン、トリエチレンテトラミン、テトラエチレンペンタミン等のポリアミン類；などが挙げられる。これらの架橋剤は、１種単独用いてもよく、２種以上を組み合わせて用いてもよい。 As the crosslinking agent, those commonly used in dip molding can be used, for example, sulfur such as powdered sulfur, sulfur dioxide, precipitated sulfur, colloidal sulfur, surface treated sulfur, insoluble sulfur, etc .; sulfur chloride, sulfur dichloride, morpholine disulfide And sulfur-containing compounds such as alkylphenol disulfide, dibenzothiazyl disulfide, caprolactam disulfide, phosphorus-containing polysulfide, polymer polysulfide, etc .; tetramethylthiuram disulfide, selenium dimethyldithiocarbamate, 2- (4'-morpholinodithio) benzothiazole, etc. Sulfur donating compounds; polyamines such as hexamethylene diamine, triethylene tetramine, tetraethylene pentamine, etc .; These crosslinking agents may be used alone or in combination of two or more.
　架橋剤の配合量は、重合体ラテックス中に含まれる重合体１００重量部に対し、好ましくは０．５～１０重量部、より好ましくは０．５～５重量部である。 The compounding amount of the crosslinking agent is preferably 0.5 to 10 parts by weight, more preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of the polymer contained in the polymer latex.
　架橋剤として硫黄を使用する場合には、架橋促進剤（加硫促進剤）や、酸化亜鉛を併用することが好ましい。
　架橋促進剤（加硫促進剤）としては、特に限定されないが、たとえば、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－モルホリニル－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、これらの中でも、ジエチルジチオカルバミン酸亜鉛、ジブ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。これらの架橋促進剤は、１種単独用いてもよく、２種以上を組み合わせて用いてもよい。 When using sulfur as a crosslinking agent, it is preferable to use a crosslinking accelerator (vulcanization accelerator) and zinc oxide in combination.
The crosslinking accelerator (vulcanization accelerator) is not particularly limited, and examples thereof include dithiocarbamates such as diethyldithiocarbamic acid, dibutyldithiocarbamic acid, di-2-ethylhexyl dithiocarbamic acid, dicyclohexyl dithiocarbamic acid, diphenyl dithiocarbamic acid, and dibenzyl dithiocarbamic acid. Acids and their zinc salts; 2-mercaptobenzothiazole, 2-mercaptobenzothiazole zinc, 2-mercaptothiazoline, dibenzothiazyl disulfide, 2- (2,4-dinitrophenylthio) benzothiazole, 2- (N, N-diethylthio carbamoylthio) benzothiazole, 2- (2,6-dimethyl-4-morpholinothio) benzothiazole, 2- (4'-morpholino dithio) benzothiazole, 4-mole Among these, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, 2-mercaptobenzothiazole, 2-mercapto, and the like can be mentioned. Benzothiazole zinc is preferred. These crosslinking accelerators may be used alone or in combination of two or more.
　また、本発明の製造方法で用いるディップ成形用組成物には、所望により、架橋助剤、充填剤、ｐＨ調整剤、増粘剤、老化防止剤、分散剤、顔料、充填剤、軟化剤等を配合してもよい。 Further, in the dip molding composition used in the production method of the present invention, if necessary, a cross-linking aid, filler, pH adjuster, thickener, anti-aging agent, dispersant, pigment, filler, softener, etc. May be blended.
　本発明の製造方法で用いるディップ成形用組成物の固形分濃度は、好ましくは３．０～５０重量％、より好ましくは５．０～４０重量％である。更に好ましくは、７．０～４０重量％である。また、本発明の製造方法で用いるディップ成形用組成物のｐＨは、好ましくは８．５～１２、より好ましくは９～１１である。 The solid content concentration of the dip molding composition used in the production method of the present invention is preferably 3.0 to 50% by weight, more preferably 5.0 to 40% by weight. More preferably, it is 7.0 to 40% by weight. The pH of the dip molding composition used in the production method of the present invention is preferably 8.5 to 12, more preferably 9 to 11.
＜ディップ成形体の製造方法＞
　次いで、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、上述した重合体ラテックスを含有するディップ成形用組成物を、凝固塩として硝酸塩を用いて、ディップ成形することで、ディップ成形体を製造する方法である。そして、この際に、ディップ成形用組成物中における亜硝酸イオンの量を１０重量ｐｐｍ以下に制御し、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にて、ディップ成形を行うものである。 <Method of manufacturing dip-formed body>
Then, the manufacturing method of the dip molding of this invention is demonstrated.
The method for producing a dip-formed article of the present invention is a method for producing a dip-formed article by dip-forming a dip-forming composition containing the above-mentioned polymer latex using nitrate as a coagulating salt. At this time, dip molding is performed under the condition that the amount of nitrite ion in the composition for dip molding is controlled to 10 ppm by weight or less and the amount of nitrite ion is controlled to 10 ppm by weight or less. is there.
　本発明の製造方法において、ディップ成形は、たとえば、次の方法により行うことができる。すなわち、ディップ成形用型を、凝固塩としての硝酸塩の水溶液に浸漬して、ディップ成形用型表面に硝酸塩を付着させた後、それをディップ成形用組成物に浸漬して、ディップ成形用型表面にディップ成形層を形成することにより行うことができる。 In the manufacturing method of the present invention, dip molding can be performed, for example, by the following method. That is, the die for dip molding is immersed in an aqueous solution of nitrate as a coagulated salt to make nitrate adhere to the surface of the die for dip molding, and then it is dipped in the composition for dip molding to make the die surface for dip molding It can be carried out by forming a dip molding layer on the
　凝固塩としての硝酸塩としては、たとえば、硝酸バリウム、硝酸カルシウム、硝酸亜鉛などが挙げられる。本発明の製造方法においては、凝固塩として、硝酸塩を用いるものであるが、このような硝酸塩を用いることにより、ディップ成形時の凝固性、および得られるディップ成形体の機械的特性を良好なものとすることができるものである。なお、凝固塩としての硝酸塩は、通常、水溶液の形態にて使用するが、硝酸塩の水溶液中には、さらにメタノール、エタノ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させてもよい。硝酸塩の水溶液中における、硝酸塩の濃度は、通常、５～７０重量％、好ましくは１０～５０重量％である。 Examples of the nitrate as the coagulated salt include barium nitrate, calcium nitrate, zinc nitrate and the like. In the production method of the present invention, a nitrate is used as a coagulating salt, but by using such a nitrate, a coagulating property at the time of dip molding and mechanical properties of the resulting dip-formed product are excellent. It is possible to Although nitrate as a coagulating salt is usually used in the form of an aqueous solution, a water-soluble organic solvent such as methanol or ethanol or a nonionic surfactant may be further contained in the aqueous solution of nitrate. The concentration of the nitrate in the aqueous solution of the nitrate is usually 5 to 70% by weight, preferably 10 to 50% by weight.
　本発明の製造方法においては、ディップ成形時の凝固性、および得られるディップ成形体の機械的特性を良好にできるという観点より、凝固塩として硝酸塩を用いるものであるが、その一方で、凝固塩として硝酸塩を用いてディップ成形を行うと、得られるディップ成形体に黄変などの着色の発生、特に、架橋時などの加熱などにより着色が発生してしまうという不具合があり、特に、製品価値の向上という観点より、このような着色の発生を抑制することが望ましいといえる。 In the production method of the present invention, although nitrate is used as the coagulating salt from the viewpoint that the coagulating property at the time of dip molding and the mechanical properties of the resulting dip-formed product can be made favorable, on the other hand When dip molding is performed using nitrate as a component, the resulting dip-formed product has the problem that coloring such as yellowing occurs, in particular, coloring occurs due to heating at the time of crosslinking, etc. From the viewpoint of improvement, it may be desirable to suppress the occurrence of such coloring.
　これに対し、本発明者等が、鋭意検討を行ったところ、ディップ成形に用いるディップ成形用組成物中における亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することにより、このような黄変などの着色の発生を有効に防止できることを見出し、本発明を完成させるに至ったものである。 On the other hand, when the present inventors intensively studied, by controlling the amount of nitrite ion in the dip molding composition used for dip molding to 10 ppm by weight or less, such yellowing etc. It has been found that it is possible to effectively prevent the occurrence of coloration, and the present invention has been completed.
　すなわち、本発明の製造方法においては、ディップ成形に用いる、ディップ成形用組成物中における亜硝酸イオン（ＮＯ２ －）の量を１０重量ｐｐｍ以下に制御するものであり、好ましくは８重量ｐｐｍ以下、より好ましくは６重量ｐｐｍ以下に制御することが好ましい。亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することで、得られるディップ成形体の黄変などの着色の発生を有効に抑制できる一方で、亜硝酸イオンの量が１０重量ｐｐｍを超えると、得られるディップ成形体に黄変などの着色の発生が発生してしまう。 That is, in the production method of the present invention, the amount of nitrite ion (NO 2 − ) in the dip molding composition used for dip molding is controlled to 10 ppm by weight or less, preferably 8 ppm by weight or less It is preferable to control to 6 weight ppm or less more preferably. By controlling the amount of nitrite ion to 10 ppm by weight or less, it is possible to effectively suppress the occurrence of coloring such as yellowing of the resulting dip-formed product, while when the amount of nitrite ion exceeds 10 ppm by weight, Occurrence of coloring such as yellowing occurs in the resulting dip-formed product.
　特に、本発明者等が検討を行ったところ、凝固塩として硝酸塩を用いてディップ成形を行った場合には、凝固塩としての硝酸塩が、ディップ成形用組成物中に硝酸イオン（ＮＯ３ －）の形態で混入してしまい、混入した硝酸イオンが還元されることで、亜硝酸イオン（ＮＯ２ －）となり、このような亜硝酸イオンが、得られるディップ成形体に黄変などの着色を発生させる原因となることがわかった。特に、このような硝酸塩のディップ成形用組成物中への混入による影響は、（１）ディップ成形用組成物を繰り返し使用して、ディップ成形体を繰り返し製造した場合、すなわち、ディップ成形用組成物に、ディップ成形用型の浸漬する操作を繰り返し行うことで、複数のディップ成形体を製造した場合や、（２）ディップ成形用組成物を用いて、ディップ成形体の製造を行った後、ディップ成形用組成物を一度保管し、保管したディップ成形用組成物を、再度使用してディップ成形体を製造した場合、などにおいて顕著となるものである。 In particular, in the case where the present inventors conducted investigations and conducted dip molding using nitrate as the coagulating salt, nitrate as the coagulating salt was nitrate ion (NO 3 − ) in the composition for dip molding. And nitrate ions are reduced to form nitrite ions (NO 2 − ), and such nitrite ions cause coloration such as yellowing in the resulting dip-formed product. It turned out that it causes it to In particular, the influence of such incorporation of nitrate into the dip molding composition is (1) when the dip molding is repeatedly produced using the dip molding composition repeatedly, that is, the dip molding composition In the case where a plurality of dip-formed products are manufactured by repeatedly performing the operation of dipping the dip-forming mold, or (2) after the dip-formed products are manufactured using the composition for dip-forming, dip When the dip molding composition is once stored and stored, the dip molding composition is used again to produce a dip molded product, and this becomes remarkable.
　これに対し、本発明によれば、ディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することで、上記（１）、（２）のような場合でも、得られるディップ成形体における黄変などの着色の発生を有効に抑制できるものである。 On the other hand, according to the present invention, by controlling the amount of nitrite ion in the composition for dip molding to 10 ppm by weight or less, even in the above cases (1) and (2), it can be obtained. It is possible to effectively suppress the occurrence of coloring such as yellowing in the dip-formed product.
　すなわち、たとえば、上記（１）のように、ディップ成形用組成物を繰り返し使用して、ディップ成形体を繰り返し製造した場合、すなわち、ディップ成形用組成物に、ディップ成形用型の浸漬する操作を繰り返し行うことで、複数のディップ成形体を製造した場合において、繰り返し製造している際において、ディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御し続けることで、繰り返し製造されるディップ成形体における、黄変などの着色の発生を有効に抑制できるものである。 That is, for example, as in the above (1), when a dip-formed product is repeatedly produced using the dip-forming composition repeatedly, that is, an operation of immersing the dip-forming mold in the dip-forming composition In the case where a plurality of dip-formed articles are produced repeatedly, the production is repeated by continuously controlling the amount of nitrite ion in the dip-forming composition to 10 ppm by weight or less. It is possible to effectively suppress the occurrence of coloring such as yellowing in the dip-molded product to be produced.
　なお、この場合において、ディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御する方法としては、特に限定されないが、たとえば、ディップ成形用組成物中における、硝酸イオンの量を、好ましくは１０重量ｐｐｍ以下、より好ましくは８重量ｐｐｍ以下、さらに好ましくは６重量ｐｐｍ以下に制御する方法や、ディップ成形用組成物中における脱窒菌の量を、好ましくは１．０×１０５（ＣＦＵ／ｍｌ）以下、より好ましくは１．０×１０４（ＣＦＵ／ｍｌ）以下、さらに好ましくは１．０×１０３（ＣＦＵ／ｍｌ）以下に制御する方法などが挙げられる。硝酸イオンの量、および脱窒菌の量のうち少なくとも一方を上記範囲とすることにより、ディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することができるものである。 In this case, the method for controlling the amount of nitrite ion in the dip molding composition to 10 ppm by weight or less is not particularly limited. For example, the amount of nitrate ion in the dip molding composition Preferably, the amount of denitrifying bacteria is controlled to 10 wt ppm or less, more preferably 8 wt ppm or less, still more preferably 6 wt ppm or less, and the amount of denitrifying bacteria in the composition for dip molding is preferably 1.0 × 10 10 A method of controlling to 5 (CFU / ml) or less, more preferably 1.0 × 10 4 (CFU / ml) or less, and further preferably 1.0 × 10 3 (CFU / ml) or less can be mentioned. By setting at least one of the amount of nitrate ion and the amount of denitrifying bacteria in the above range, the amount of nitrite ion in the composition for dip molding can be controlled to 10 ppm by weight or less.
　たとえば、ディップ成形用組成物を繰り返し使用して、ディップ成形体を繰り返し製造し、複数のディップ成形体を得た場合には、ディップ成形を繰り返し行うことに伴い、凝固塩としての硝酸塩に由来する硝酸イオンの量が増加したり、あるいは、ディップ成形用組成物の作製後、保管時やディップ成形時に、外気から不可避的に脱窒菌が取り込まれてしまうのに対し、これら硝酸イオンの量、および脱窒菌の量を上記範囲に制御することにより、ディップ成形用組成物中における、亜硝酸イオンの量を上述した所定の範囲に制御できるものである。特に、本発明者等が検討を行ったところ、ディップ成形用組成物中において、凝固塩としての硝酸塩に由来する硝酸イオンが、亜硝酸イオンに還元される原因としては、主として脱窒菌の関与が考えられるところ、硝酸イオンの量、および脱窒菌の量のうち少なくとも一方を上記範囲とすることにより、ディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することができるものである。なお、たとえば、硝酸イオンの量が上記した範囲より多い場合であっても、脱窒菌の量が上記範囲であれば、亜硝酸イオンの生成を有効に抑制でき、これにより、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することが可能であり、同様に、脱窒菌の量が上記した範囲より多い場合であっても、硝酸イオンの量が上記範囲であれば、亜硝酸イオンの生成を有効に抑制でき、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することができるものである。 For example, when a dip-formed product is repeatedly produced using a dip-forming composition repeatedly to obtain a plurality of dip-formed products, the dip-formed product is derived from nitrate as a coagulated salt along with repeated dip-forming. While the amount of nitrate ions increases, or after preparation of the composition for dip molding, denitrifying bacteria are unavoidably taken in from the open air during storage or dip molding, the amounts of these nitrate ions, and By controlling the amount of denitrifying bacteria within the above range, the amount of nitrite ion in the composition for dip molding can be controlled within the above-described predetermined range. In particular, when the present inventors examined, in the composition for dip molding, the contribution of denitrifying bacteria is mainly due to the reduction of nitrate ions derived from nitrate as coagulated salt to nitrite ions in the composition for dip molding As can be considered, the amount of nitrite ion in the composition for dip molding can be controlled to 10 ppm by weight or less by setting at least one of the amount of nitrate ion and the amount of denitrifying bacteria in the above range. It is a thing. For example, even if the amount of nitrate ions is larger than the above range, if the amount of denitrifying bacteria is in the above range, the generation of nitrite ions can be effectively suppressed, whereby the amount of nitrite ions can be reduced. If the amount of nitrate ion is in the above range, it is possible to control the formation of nitrite ion, even if the amount of denitrifying bacteria is larger than the above range. It can be effectively suppressed and the amount of nitrite ion can be controlled to 10 ppm by weight or less.
　なお、脱窒菌は、硝酸イオンを還元する反応を行う多種多様な微生物の総称であり、細菌類の他、真菌類も挙げられる。脱窒菌としては、たとえば、シュードモナス・エアルギノーザ、シュードモナス・デニトリフィカンス、シュードモナス・スタツェリ等のシュードモナス属の細菌のほか、ミクロコッカス属、パラコッカス属等に属する細菌などが挙げられる。 In addition, denitrifying bacteria is a generic name of various microorganisms which perform the reaction which reduces nitrate ion, and in addition to bacteria, fungi are also mentioned. Examples of the denitrifying bacteria include bacteria belonging to the genus Pseudomonas, such as Pseudomonas aeruginosa, Pseudomonas denitrificans, Pseudomonas stazelli, and bacteria belonging to the genus Micrococcus and Paracoccus.
　また、ディップ成形用組成物中における、硝酸イオンの量を上記範囲に制御する方法としては、特に限定されないが、硝酸塩を付着させたディップ成形用型を、ディップ成形用組成物に浸漬した後、表面にディップ成形層を形成したディップ成形用型を引き上げる際に、ディップ成形用型から滴下する、硝酸塩を含む液体が、ディップ成形用組成物中に混入しないよう制御する方法や、ディップ成形における、ディップ成形用型の浸漬時間を２～５秒と短くする方法などが挙げられる。具体的には、ディップ成形用型を引き上げた際に、ディップ成形用組成物を含むディップ槽に蓋をする方法などが挙げられる。ただし、このような方法に特に限定されるものでなく、硝酸イオンの量を上記範囲に制御できる方法であれば何でもよい。 The method for controlling the amount of nitrate ion in the dip molding composition to be in the above range is not particularly limited, but after dipping the dip molding die having the nitrate attached thereto in the dip molding composition, When pulling up a dip molding die having a dip molding layer formed on the surface, a method of controlling the liquid containing nitrate, which is dropped from the dip molding die, not to be mixed in the dip molding composition, or in dip molding, A method of shortening the immersion time of the die for dip molding to 2 to 5 seconds may, for example, be mentioned. Specifically, a method of covering the dip tank containing the composition for dip molding when the die for dip molding is pulled up, and the like can be mentioned. However, it is not particularly limited to such a method, and any method can be used as long as the amount of nitrate ion can be controlled within the above range.
　さらに、ディップ成形用組成物中における、脱窒菌の量を上記範囲とする方法としては、特に限定されないが、ディップ成形用組成物を作製した後、保管を行う際における環境を、外気と触れないような環境とする方法（たとえば、ディップ成形用組成物の単位容積当たりの液面の面積を小さくする方法）や、外気との接触面積をできるだけ少なくする方法、さらには、ディップ成形を繰り返し行う際における環境（外気環境）を、脱窒菌の量が管理された環境とする方法や、ディップ成形用組成物における外気との接触面積ができるだけ少なくなるような態様にてディップ成形を行う方法などが挙げられる。 Furthermore, the method for setting the amount of denitrifying bacteria in the above-mentioned range in the composition for dip molding is not particularly limited, but the environment at the time of storage after producing the composition for dip molding is not exposed to the outside air Method (for example, a method for reducing the area of the liquid surface per unit volume of the composition for dip molding), a method for reducing the contact area with the outside air as much as possible, The method of setting the environment (open air environment) in the environment as the environment where the amount of denitrifying bacteria was managed, and the method of performing dip molding in such a mode that the contact area with the open air in the composition for dip molding is minimized Be
　また、上記（２）のように、ディップ成形用組成物を用いて、ディップ成形体の製造を行った後、ディップ成形用組成物を一度保管し、保管したディップ成形用組成物を、再度使用してディップ成形体を製造する際においては、保管中および保管後、さらには、再度使用する際におけるディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することで、保管後のディップ成形用組成物を用いて製造されるディップ成形体における、黄変などの着色の発生を有効に抑制できるものである。 In addition, as described in (2) above, after the dip-molded product is manufactured using the dip-forming composition, the dip-forming composition is stored once, and the stored dip-forming composition is used again When manufacturing a dip-formed product, by controlling the amount of nitrite ion to 10 ppm by weight or less in the dip-forming composition during storage and after storage, and again when used again, It is possible to effectively suppress the occurrence of coloring such as yellowing in a dip-molded product produced using the dip molding composition after storage.
　なお、この場合において、ディップ成形用組成物中における、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御する方法としては、特に限定されないが、上記（１）の場合と同様に、たとえば、ディップ成形用組成物を用いてディップ成形を行った後の保管中、あるいは保管後、さらには、再度使用する際における、ディップ成形用組成物中における、硝酸イオンの量を、好ましくは１０重量ｐｐｍ以下、より好ましくは８重量ｐｐｍ以下、さらに好ましくは６重量ｐｐｍ以下に制御する方法や、ディップ成形用組成物中における脱窒菌の量を、好ましくは１．０×１０５（ＣＦＵ／ｍｌ）以下、より好ましくは１．０×１０４（ＣＦＵ／ｍｌ）以下、さらに好ましくは１．０×１０３（ＣＦＵ／ｍｌ）以下に制御する方法などが挙げられる。 In this case, the method for controlling the amount of nitrite ion in the dip molding composition to 10 ppm by weight or less is not particularly limited, but, for example, dip molding as in the case of the above (1) The amount of nitrate ion in the dip-forming composition during storage after dip molding using the composition for the present invention, or after storage, and again when used again is preferably 10 ppm by weight or less, The amount of denitrifying bacteria in the dip molding composition is preferably 1.0 × 10 5 (CFU / ml) or less, more preferably 8 wt ppm or less, and even more preferably 6 wt ppm or less. preferably 1.0 × 10 4 (CFU / ml ) or less, and a method of more preferably controlled to 1.0 × 10 3 (CFU / ml ) or less
　特に、ディップ成形用組成物の保管中には、凝固塩としての硝酸塩に由来する硝酸イオンが新たに増加することはないものの、保管前に行ったディップ成形によって、ディップ成形用組成物中に、凝固塩としての硝酸塩に由来する硝酸イオンが取り込まれており、これにより、硝酸イオンの量が上記範囲よりも多い量となっており、かつ、脱窒菌の量が１．０×１０５（ＣＦＵ／ｍｌ）超であると、保管環境によっては、保管中に亜硝酸イオンが生成してしまうこととなる。そのため、上記（２）の場合においては、保管後のディップ成形用組成物を用いて、再度、ディップ成形を行う際に加え、このような保管中においても、硝酸イオンの量および脱窒菌の量のうち少なくとも一方を上記範囲に制御することが好ましく、これにより、保管中における、亜硝酸イオンの生成を抑制することが望ましい。なお、この場合における、硝酸イオンの量および脱窒菌の量を上記範囲とする方法としては、上記（１）の場合と同様とすればよい。また、保管後のディップ成形用組成物を用いて、再度、ディップ成形を行う際には、上記（１）の場合と同様に、硝酸イオンの量および脱窒菌の量のうち少なくとも一方を上記範囲に制御すること好ましい。 In particular, during storage of the composition for dip molding, although the nitrate ion derived from the nitrate as the coagulated salt does not newly increase, the dip molding composition is subjected to dip molding performed before storage. The nitrate ion derived from the nitrate as the coagulated salt is taken in, whereby the amount of nitrate ion is larger than the above range, and the amount of denitrifying bacteria is 1.0 × 10 5 (CFU (CFU). If it exceeds / ml, depending on the storage environment, nitrite ions may be generated during storage. Therefore, in the case of the above (2), the composition for dip molding after storage is used again for dip molding, and even during such storage, the amount of nitrate ion and the amount of denitrifying bacteria It is preferable to control at least one of them in the above range, and thereby it is desirable to suppress the formation of nitrite ion during storage. The amount of nitrate ion and the amount of denitrifying bacteria in this case may be the same as in the above case (1). Moreover, when performing dip molding again using the composition for dip molding after storage, at least one of the amount of nitrate ion and the amount of denitrifying bacteria is in the above range as in the case of the above (1). It is preferable to control the
　一方で、ディップ成形用組成物中における硝酸イオンの量、および脱窒菌の量の両方が上記範囲よりも多い場合であっても、保管中の温度を、好ましくは０～１８℃の範囲、より好ましくは０～１５℃の範囲とすることで、脱窒菌を不活性化することができるため、保管中の温度をこのような範囲とする方法を採用することも好ましい。特に、この場合には、保管前における、ディップ成形用組成物中における硝酸イオンの量、および脱窒菌の量の両方が上記範囲よりも多い場合でも、保管中の温度を上記範囲とすることにより、脱窒菌を不活性化させることで、脱窒菌を減少させることができ（たとえば、１．０×１０５（ＣＦＵ／ｍｌ）以下とすることができ）、これにより、亜硝酸イオンの量を１０重量ｐｐｍ以下に制御することが可能となる。 On the other hand, even when both the amount of nitrate ion and the amount of denitrifying bacteria in the composition for dip molding are larger than the above ranges, the temperature during storage is preferably in the range of 0 to 18 ° C., Since denitrifying bacteria can be inactivated by setting the temperature preferably in the range of 0 to 15 ° C., it is also preferable to adopt a method in which the temperature during storage is in such a range. In this case, in particular, by setting the temperature during storage to the above range, even when the amount of nitrate ion and the amount of denitrifying bacteria in the dip molding composition before storage are both larger than the above ranges. By deactivating denitrifying bacteria, denitrifying bacteria can be reduced (for example, 1.0 × 10 5 (CFU / ml) or less), whereby the amount of nitrite ion can be reduced. It becomes possible to control to 10 weight ppm or less.
　また、本発明の製造方法においては、ディップ成形用組成物を用いてディップ成形を行う前に、ディップ成形用組成物の熟成（前加硫ともいう。）を行い、熟成させたものを用いてもよい。
　熟成する時間は、特に限定されず、熟成する温度にもよるが、好ましくは１～１４日間であり、より好ましくは１～７日間である。また、熟成温度は、好ましくは５～４０℃、より好ましくは２０～４０℃である。熟成を行う際においても、脱窒菌の混入を抑制するという観点より、熟成を行う際における環境を、外気と触れないような環境とする方法や、外気との接触面積をできるだけ少なくする方法を採用することが好ましい。 Further, in the production method of the present invention, prior to dip molding using the dip molding composition, the dip molding composition is aged (also referred to as pre-vulcanization) and then aged. It is also good.
The time for ripening is not particularly limited, although depending on the temperature for ripening, it is preferably 1 to 14 days, more preferably 1 to 7 days. The ripening temperature is preferably 5 to 40 ° C., more preferably 20 to 40 ° C. Even when the aging is performed, from the viewpoint of suppressing the mixture of denitrifying bacteria, a method of making the environment at the time of aging an environment which does not touch the outside air or a method of minimizing the contact area with the outside air is adopted. It is preferable to do.
　ディップ成形時の温度、すなわち、ディップ成形時におけるディップ成形用組成物の温度は、好ましくは２０～４０℃の範囲、より好ましくは２２～３８℃の範囲である。ディップ成形時におけるディップ成形用組成物の温度が低すぎても、また、高すぎても、ディップ成形が困難となったり、ディップ成形用型の表面に形成されるディップ成形層の厚みが不均一となる場合がある。 The temperature at the time of dip molding, that is, the temperature of the composition for dip molding at the time of dip molding is preferably in the range of 20 to 40 ° C., more preferably in the range of 22 to 38 ° C. Even if the temperature of the dip molding composition during dip molding is too low or too high, dip molding becomes difficult or the thickness of the dip molding layer formed on the surface of the dip molding die is uneven. It may be
　ディップ成形により得られたディップ成形層は、通常、加熱処理を施し架橋する。加熱処理を施す前に、水、好ましくは３０～７０℃の温水に、１～６０分程度浸漬し、水溶性不純物（たとえば、余剰の乳化剤や凝固剤等）を除去してもよい。水溶性不純物の除去操作は、ディップ成形層を加熱処理した後に行なってもよいが、より効率的に水溶性不純物を除去できる点から、加熱処理前に行なうことが好ましい。 The dip-formed layer obtained by dip-forming is usually subjected to heat treatment to be crosslinked. Before the heat treatment, the substrate may be immersed in water, preferably warm water at 30 to 70 ° C., for about 1 to 60 minutes to remove water-soluble impurities (eg, excess emulsifier, coagulant, etc.). The removal operation of the water-soluble impurities may be carried out after the dip molding layer is heat-treated, but it is preferable to be carried out before the heat treatment in that the water-soluble impurities can be removed more efficiently.
　ディップ成形層の架橋は、通常、１００～１５０℃の温度で、好ましくは１０～１２０分の加熱処理を施すことにより行われる。加熱の方法としては、赤外線や加熱空気による外部加熱または高周波による内部加熱による方法が採用できる。なかでも、加熱空気による外部加熱が好ましい。 Crosslinking of the dip-formed layer is usually carried out by heat treatment at a temperature of 100 to 150 ° C., preferably for 10 to 120 minutes. As a heating method, a method by external heating with infrared rays or heated air or internal heating with high frequency can be adopted. Among them, external heating by heating air is preferable.
　そして、架橋したディップ成形層をディップ成形用型から取り外すことによって、ディップ成形体が得られる。取り外す際の方法としては、手で成形用型から剥したり、水圧や圧縮空気の圧力により剥したりする方法を採用することができる。なお、ディップ成形用型から取り外した後、さらに６０～１２０℃の温度で、１０～１２０分の加熱処理を行なってもよい。 And a dip-molded body is obtained by removing the crosslinked dip-formed layer from the dip-forming mold. As a method of removing, it is possible to adopt a method of peeling off from the mold by hand or peeling by water pressure or pressure of compressed air. After removal from the dip mold, heat treatment may be further performed at a temperature of 60 to 120 ° C. for 10 to 120 minutes.
　本発明の製造方法により得られるディップ成形体は、黄変などの変色の発生が有効に抑制されたものであり、たとえば、手袋用途、とりわけ、薄手の手術用手袋に好適であり、あるいは、手袋の他にも、哺乳瓶用乳首、スポイト、チューブ、水枕、バルーンサック、カテーテル、コンドームなどの医療用品；風船、人形、ボールなどの玩具；加圧成形用バック、ガス貯蔵用バックなどの工業用品；指サックなどにも用いることができる。 The dip-formed article obtained by the production method of the present invention is one in which the occurrence of discoloration such as yellowing is effectively suppressed, and is suitable, for example, for gloves, particularly for thin surgical gloves, or gloves In addition to baby bottle nipples, syringes, tubes, water pillows, balloon sacks, catheters, condoms and other medical supplies; balloons, dolls, toys such as balls; industrial products such as back pressure bags, gas storage bags It can also be used as a finger sack.
　以下に、実施例を挙げて、本発明についてより具体的に説明するが、本発明はこの実施例に限られるものではない。以下において、特記しない限り、「部」は重量基準である。物性および特性の試験または評価方法は以下のとおりである。 Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to these examples. In the following, unless otherwise stated, "parts" is by weight. The test or evaluation method of physical properties and characteristics is as follows.
＜硝酸イオン量、亜硝酸イオン量＞
　ディップ成形用組成物を、イオン交換水を用いて１０００倍に希釈した。希釈した液体を、１１０，０００ｒｐｍにて２時間遠心分離を行い、固層と液相に分離した。次いで、遠心分離後の試料から液相を採取し、これを０．２μｍのフィルターを通すことで透明な液体を得て、得られた透明な液体について、アニオンクロマトグラフィーによる測定を行うことで、ディップ成形用組成物中における硝酸イオン量、亜硝酸イオン量を測定した。 <Amount of nitrate ion, amount of nitrite ion>
The composition for dip molding was diluted 1000 times with ion exchange water. The diluted liquid was centrifuged at 110,000 rpm for 2 hours to separate into a solid phase and a liquid phase. Then, the liquid phase is collected from the sample after centrifugation, and this is passed through a 0.2 μm filter to obtain a transparent liquid, and the obtained transparent liquid is subjected to measurement by anion chromatography, The amount of nitrate ion and the amount of nitrite ion in the dip molding composition were measured.
＜脱窒菌量＞
　カルボキシル基含有ニトリルゴムのラテックス、ディップ成形用組成物に、細菌検出用培地（製品名「Ｅａｓｉｃｕｌｔ（Ｒ）ＴＴＣ」、オリオン社製）を浸し、２９℃で４８時間菌を培養した後、細菌検出用培地に生じたコロニーの数を観察することで、カルボキシル基含有ニトリルゴムのラテックス、またはディップ成形用組成物１ｍＬあたりのコロニー数をカウントして、脱窒菌量（単位：ＣＦＵ／ｍｌ）を求めた。 <Amount of denitrifying bacteria>
A medium for detecting bacteria (product name "Easicult (R) TTC", manufactured by Orion) is immersed in a carboxyl group-containing nitrile rubber latex or dip molding composition, and the bacteria are cultured at 29 ° C for 48 hours, and then the bacteria are detected. By observing the number of colonies formed in the culture medium, count the number of colonies per 1 mL of carboxyl group-containing nitrile rubber latex or dip molding composition to determine the amount of denitrifying bacteria (unit: CFU / ml) The
＜黄色度測定＞
　ディップ成形により得られたフィルム状成形体を、オーブンに入れ１２０℃で２０分間の条件で加硫させた。そして、加硫後のフィルム状成形体について、カラーメーターを用いて、黄色度（ＹＩ）の測定を行った。黄色度（ＹＩ）は、以下の基準で評価した。
　　Ａ：黄色度（ＹＩ）が５未満
　　Ｂ：黄色度（ＹＩ）が５以上、１０未満
　　Ｃ：黄色度（ＹＩ）が１０以上 <Yellowness measurement>
The film-like molded product obtained by dip molding was put into an oven and vulcanized at 120 ° C. for 20 minutes. Then, the degree of yellowness (YI) of the film-like molded product after vulcanization was measured using a color meter. Yellowness (YI) was evaluated according to the following criteria.
A: Yellowness (YI) is less than 5 B: Yellowness (YI) is 5 or more, less than 10 C: Yellowness (YI) is 10 or more
＜製造例１＞
　窒素置換した耐圧重合反応器に、初期重合単量体として、アクリロニトリル１３．５部、１，３－ブタジエン３３．７５部およびメタクリル酸２．７５部、分子量調整剤としてｔ－ドデシルメルカプタン（ｔＤＭ）０．５部、脱イオン水９５部、乳化剤としてドデシルベンゼンスルホン酸ナトリウム（ＤＢＳ）１．０部、重合開始剤として過硫酸カリウム０．２部、ならびに、還元剤としてエチレンジアミン四酢酸ナトリウム（ＥＤＴＡ）０．１部を仕込み、重合系内の温度を３５℃に上昇させて重合反応を開始した。そして、重合転化率が５０％になった時点で、追加の乳化剤として、ドデシルベンゼンスルホン酸ナトリウム１．０部を１０％水溶液の形態で一括添加した。その後、残余の単量体として、アクリロニトリル１３．５部、１，３－ブタジエン３３．７５部およびメタクリル酸２．７５部からなる単量体混合物、ならびに、ｔ－ドデシルメルカプタン０．４部を脱イオン水１５．０部およびドデシルベンゼンスルホン酸ナトリウム０．５部にて乳化して得られたエマルジョンを、２７０分間に亘って、重合系に連続添加した。この連続添加終了時の重合転化率は６０％であった。その後、全単量体の重合転化率が９７％になるまで重合を継続した後、重合停止剤としてジエチルヒドロキシルアミン０．１部を添加することで重合反応を停止した。
　そして、得られたラテックスから、未反応単量体を留去した後、固形分濃度およびｐＨを調整することで、固形分濃度４５％、ｐＨ８．３のカルボキシル基含有ニトリルゴムのラテックスを得た。 <Production Example 1>
In a nitrogen-substituted pressure resistant polymerization reactor, 13.5 parts of acrylonitrile, 33.75 parts of 1,3-butadiene and 2.75 parts of methacrylic acid as initial polymerization monomers, and t-dodecyl mercaptan (tDM) as a molecular weight modifier 0.5 parts, 95 parts of deionized water, 1.0 part of sodium dodecylbenzene sulfonate (DBS) as an emulsifier, 0.2 parts of potassium persulfate as a polymerization initiator, and sodium ethylenediaminetetraacetate (EDTA) as a reducing agent 0.1 parts was charged, and the temperature in the polymerization system was raised to 35 ° C. to start the polymerization reaction. Then, when the polymerization conversion ratio reached 50%, 1.0 part of sodium dodecylbenzene sulfonate was added at once in the form of a 10% aqueous solution as an additional emulsifier. Thereafter, as the remaining monomers, a monomer mixture consisting of 13.5 parts of acrylonitrile, 33.75 parts of 1,3-butadiene and 2.75 parts of methacrylic acid, and 0.4 parts of t-dodecyl mercaptan are removed. An emulsion obtained by emulsifying with 15.0 parts of ion water and 0.5 parts of sodium dodecylbenzene sulfonate was continuously added to the polymerization system over 270 minutes. The polymerization conversion rate at the end of the continuous addition was 60%. Thereafter, the polymerization was continued until the polymerization conversion of all the monomers reached 97%, and then the polymerization reaction was stopped by adding 0.1 part of diethylhydroxylamine as a polymerization terminator.
Then, after distilling off unreacted monomers from the obtained latex, the solid content concentration and pH were adjusted to obtain a latex of carboxyl group-containing nitrile rubber having a solid content concentration of 45% and pH 8.3. .
＜参考例１＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスを、固形分濃度２５重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度２５重量％、ｐＨ１０．０のディップ成形用組成物を得た。また、上記とは別に、硝酸カルシウム１３部、非イオン性乳化剤としてのポリオキシエチレンオクチルフェニルエーテル０．０５部、および水８７部を混合することで、凝固剤水溶液を調製した。 Reference Example 1
The latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 is adjusted to a solid content concentration of 25% by weight, and then the vulcanizing agent dispersion liquid relative to 100 parts of the solid content in the latex whose solid content concentration is adjusted (A dispersion consisting of 1 part of sulfur, 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water) After mixing 8.66 parts, an appropriate amount of A 5 wt% aqueous potassium hydroxide solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 25 wt% and a pH of 10.0. Further, separately from the above, an aqueous coagulant solution was prepared by mixing 13 parts of calcium nitrate, 0.05 parts of polyoxyethylene octyl phenyl ether as a nonionic emulsifier, and 87 parts of water.
　そして、上記にて得られたディップ成形用組成物および凝固剤水溶液を用いて、ディップ成形を行った。具体的には、セラミックモールドを、凝固剤水溶液中に１分間浸漬し、引き上げた後、７０℃で３０分間乾燥して、凝固剤をセラミックモールドに付着させた。次いで、凝固剤の付着したセラミックモールドを、温度３０℃としたディップ成形用組成物中に２秒間浸漬し、引き上げた。なお、本例においては、ディップ成形用組成物から、セラミックモールドを引き上げた際に、ディップ成形用組成物が入っているディップ槽に蓋をすることで、セラミックモールド表面に形成されたディップ成形層から滴下する、硝酸イオンを含む液体（ショウ液）が、ディップ成形用組成物中に混入しないようにする対策（ショウ液カット）を行った。そして、本例においては、このようなディップ成形を５０回行った。 And dip molding was performed using the composition for dip molding obtained above, and the coagulant | flocculant aqueous solution. Specifically, the ceramic mold was immersed in an aqueous coagulant solution for 1 minute, pulled up, and dried at 70 ° C. for 30 minutes to attach the coagulant to the ceramic mold. Then, the ceramic mold to which the coagulant was attached was immersed in the dip molding composition at a temperature of 30 ° C. for 2 seconds and pulled up. In this example, when the ceramic mold is pulled up from the dip molding composition, the dip molding layer formed on the surface of the ceramic mold is covered by covering the dip tank containing the dip molding composition. As a solution (show solution cut) to prevent the liquid containing nitrate ion (show solution) dropped from the above from mixing into the dip molding composition. And in this example, such dip molding was performed 50 times.
　５０回のディップ成形を行った後のディップ成形用組成物中の硝酸イオン量を測定したところ、ディップ成形用組成物に含まれる硝酸イオン量は０重量ｐｐｍであった。 The amount of nitrate ion in the composition for dip molding after 50 times of dip molding was measured, and the amount of nitrate ion contained in the composition for dip molding was 0 weight ppm.
＜参考例２＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスを、固形分濃度１７重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度１７重量％、ｐＨ１０．０のディップ成形用組成物を得た。 Reference Example 2
The latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 is adjusted to a solid content concentration of 17% by weight, and then a vulcanizing agent dispersion liquid relative to 100 parts of the solid content in the latex whose solid content concentration is adjusted. (A dispersion consisting of 1 part of sulfur, 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water) After mixing 8.66 parts, an appropriate amount of A 5 wt% potassium hydroxide aqueous solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 17 wt% and a pH of 10.0.
　そして、上記にて得られたディップ成形用組成物および参考例１と同様にして調製した凝固剤水溶液を用いて、ディップ成形を行った。具体的には、ディップ成形用組成物中における、セラミックモールドの浸漬時間を２秒から１０秒に変更した以外は、参考例１と同様にして、５０回のディップ成形を行った。 And dip molding was performed using the composition for dip molding obtained above, and the coagulant aqueous solution prepared like the reference example 1. Specifically, 50 dip moldings were performed in the same manner as in Reference Example 1 except that the immersion time of the ceramic mold in the dip molding composition was changed from 2 seconds to 10 seconds.
　５０回のディップ成形を行った後のディップ成形用組成物中の硝酸イオン量を測定したところ、ディップ成形用組成物に含まれる硝酸イオン量は１５重量ｐｐｍであった。 The amount of nitrate ion in the composition for dip molding after 50 times of dip molding was measured, and the amount of nitrate ion contained in the composition for dip molding was 15 weight ppm.
＜参考例３＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスを、固形分濃度９重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度９重量％、ｐＨ１０．０のディップ成形用組成物を得た。 Reference Example 3
The latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 is adjusted to a solid concentration of 9% by weight, and then the vulcanizing agent is dispersed relative to 100 parts of the solid content in the latex whose solid concentration is adjusted. (A dispersion consisting of 1 part of sulfur, 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water) After mixing 8.66 parts, an appropriate amount of A 5 wt% potassium hydroxide aqueous solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 9 wt% and a pH of 10.0.
　そして、上記にて得られたディップ成形用組成物および参考例１と同様にして調製した凝固剤水溶液を用いて、ディップ成形を行った。具体的には、ディップ成形用組成物中における、セラミックモールドの浸漬時間を２秒から３０秒に変更するとともに、硝酸イオンを含む液体（ショウ液）が、ディップ成形用組成物中に混入しないようにする対策（ショウ液カット）を行わなかった以外は、参考例１と同様にして、５０回のディップ成形を行った。 And dip molding was performed using the composition for dip molding obtained above, and the coagulant aqueous solution prepared like the reference example 1. Specifically, the immersion time of the ceramic mold in the composition for dip molding is changed from 2 seconds to 30 seconds, and a liquid containing nitrate ion (show solution) is not mixed in the composition for dip molding The dip molding was performed 50 times in the same manner as in Reference Example 1 except that no countermeasure (show solution cut) was performed.
　５０回のディップ成形を行った後のディップ成形用組成物中の硝酸イオン量を測定したところ、ディップ成形用組成物に含まれる硝酸イオン量は７８０重量ｐｐｍであった。 The amount of nitrate ion in the composition for dip molding after 50 times of dip molding was measured, and the amount of nitrate ion contained in the composition for dip molding was 780 ppm by weight.
＜実施例１＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスに、脱窒菌を培養した培地を浸漬させ、１日室温で保管することで、脱窒菌をラテックス中で繁殖させた。脱窒菌数を上記方法にて測定したところ、１．０×１０６（ＣＦＵ／ｍｌ）以上であった。次いで、脱窒菌を繁殖させたラテックスを、固形分濃度２５重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度２５重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２以上の量となるように、容器中に入れ、蓋をすることで、外気との接触が無い環境にして、３０℃で１日間熟成させた。 Example 1
The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex. The number of denitrifying bacteria was measured by the above method and found to be 1.0 × 10 6 (CFU / ml) or more. Next, the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 25% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex whose solid concentration is adjusted) A dispersion consisting of 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), and after mixing 8.66 parts, an appropriate amount of 5% by weight of hydroxylation A potassium aqueous solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 25% by weight and a pH of 10.0. Then, the obtained dip molding composition is placed in a container so that the amount thereof is 1/2 or more of the volume of the container, and the container is covered to provide an environment free from contact with the outside air, Aging was carried out for 1 day at ° C.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例１と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例１と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 1 except that the composition for dip molding thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 1.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２以上の量にて、蓋をすることで、外気との接触が無い環境にして、１日間３０℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得た。そして、上記方法にしたがって、評価用ディップ成形体を得た後のディップ成形用組成物中の亜硝酸イオン量、脱窒菌数、および、評価用ディップ成形体の黄色度の各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is covered with an amount of 1/2 or more of the container volume in the same container, so that there is no contact with the open air. Under the environment, stored at 30 ° C. for 1 day, and using the dip molding composition after storage, dip molding was performed again under the same conditions to obtain a dip molded article for evaluation. And according to the said method, each measurement of the nitrite ion amount in the composition for dip molding after obtaining the dip molding for evaluation, the denitrifying bacteria number, and the yellowness degree of the dip molding for evaluation was performed. The results are shown in Table 2.
＜実施例２＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスについて、脱窒菌数を上記方法にて測定することで、脱窒菌数が１．０×１０３（ＣＦＵ／ｍｌ）以下であることを確認した後、該ラテックスを、固形分濃度９重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度９重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２以上の量となるように、容器中に入れ、蓋をすることで、外気との接触が無い環境にして、３０℃で１日間熟成させた。 Example 2
Regarding the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1, it is confirmed that the denitrifying bacteria count is 1.0 × 10 3 (CFU / ml) or less by measuring the denitrifying bacteria count by the above method. Then, the latex was adjusted to a solid concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, zinc oxide 1. A dispersion consisting of 5 parts, 0.5 parts of zinc diethyl carbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), Ion water was added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0. Then, the obtained dip molding composition is placed in a container so that the amount thereof is 1/2 or more of the volume of the container, and the container is covered to provide an environment free from contact with the outside air, Aging was carried out for 1 day at ° C.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例３と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例３と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 3 except that the dip molding composition thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 3.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２以上の量にて、蓋をすることで、外気との接触が無い環境にして、１日間３０℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得て、実施例１と同様にして各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is covered with an amount of 1/2 or more of the container volume in the same container, so that there is no contact with the open air. In an environment, stored at 30 ° C. for 1 day, and using the dip molding composition after storage, dip molding is performed again under the same conditions to obtain a dip molded article for evaluation, as in Example 1. Each measurement was performed. The results are shown in Table 2.
＜実施例３＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスについて、脱窒菌数を上記方法にて測定することで、脱窒菌数が１．０×１０３（ＣＦＵ／ｍｌ）以下であることを確認した後、該ラテックスを、固形分濃度１７重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度１７重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２未満の量となるように、容器中に入れ、かつ、蓋をしないことで、外気との接触が有る環境にして、３０℃で１日間熟成させた。 Example 3
Regarding the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1, it is confirmed that the denitrifying bacteria count is 1.0 × 10 3 (CFU / ml) or less by measuring the denitrifying bacteria count by the above method. Then, the latex is adjusted to a solid content concentration of 17% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, zinc oxide 1. A dispersion consisting of 5 parts, 0.5 parts of zinc diethyl carbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), Ion water was added to obtain a dip molding composition having a solid concentration of 17% by weight and a pH of 10.0. And, by putting the obtained composition for dip molding into the container so as to be less than a half of the volume of the container, and not covering the lid, an environment having contact with the outside air is obtained. It was aged at 30 ° C. for 1 day.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例２と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例２と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 2 except that the composition for dip molding thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 2.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２未満の量にて、かつ、蓋をしないことで、外気との接触が有る環境にして、１日間３０℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得て、実施例１と同様にして各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered. The dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 30 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
＜実施例４＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスに、脱窒菌を培養した培地を浸漬させ、１日室温で保管することで、脱窒菌をラテックス中で繁殖させた。脱窒菌数を上記方法にて測定したところ、１．０×１０６（ＣＦＵ／ｍｌ）以上であった。次いで、脱窒菌を繁殖させたラテックスを、固形分濃度９重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度９重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２未満の量となるように、容器中に入れ、かつ、蓋をしないことで、外気との接触が有る環境にして、５℃で１日間熟成させた。 Example 4
The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex. The number of denitrifying bacteria was measured by the above method and found to be 1.0 × 10 6 (CFU / ml) or more. Next, the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex of adjusted solid content concentration) A dispersion consisting of 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), and after mixing 8.66 parts, an appropriate amount of 5% by weight of hydroxylation An aqueous solution of potassium and deionized water were added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0. And, by putting the obtained composition for dip molding into the container so as to be less than a half of the volume of the container, and not covering the lid, an environment having contact with the outside air is obtained. It was aged at 5 ° C. for 1 day.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例３と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例３と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 3 except that the dip molding composition thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 3.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２未満の量にて、かつ、蓋をしないことで、外気との接触が有る環境にして、１日間５℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得て、実施例１と同様にして各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered. The dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 5 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
＜実施例５＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスに、脱窒菌を培養した培地を浸漬させ、１日室温で保管することで、脱窒菌をラテックス中で繁殖させた。脱窒菌数を上記方法にて測定したところ、１．０×１０６（ＣＦＵ／ｍｌ）以上であった。次いで、脱窒菌を繁殖させたラテックスを、固形分濃度２５重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度２５重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２未満の量となるように、容器中に入れ、かつ、蓋をしないことで、外気との接触が有る環境にして、３０℃で１日間熟成させた。 Example 5
The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex. The number of denitrifying bacteria was measured by the above method and found to be 1.0 × 10 6 (CFU / ml) or more. Next, the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 25% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex whose solid concentration is adjusted) A dispersion consisting of 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), and after mixing 8.66 parts, an appropriate amount of 5% by weight of hydroxylation A potassium aqueous solution and deionized water were added to obtain a dip molding composition having a solid content concentration of 25% by weight and a pH of 10.0. And, by putting the obtained composition for dip molding into the container so as to be less than a half of the volume of the container, and not covering the lid, an environment having contact with the outside air is obtained. It was aged at 30 ° C. for 1 day.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例１と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例１と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 1 except that the composition for dip molding thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 1.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２未満の量にて、かつ、蓋をしないことで、外気との接触が有る環境にして、１日間３０℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得て、実施例１と同様にして各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered. The dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 30 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
＜比較例１＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスに、脱窒菌を培養した培地を浸漬させ、１日室温で保管することで、脱窒菌をラテックス中で繁殖させた。脱窒菌数を上記方法にて測定したところ、１．０×１０６（ＣＦＵ／ｍｌ）以上であった。次いで、脱窒菌を繁殖させたラテックスを、固形分濃度９重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度９重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２未満の量となるように、容器中に入れ、かつ、蓋をしないことで、外気との接触が有る環境にして、３０℃で１日間熟成させた。 Comparative Example 1
The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex. The number of denitrifying bacteria was measured by the above method and found to be 1.0 × 10 6 (CFU / ml) or more. Next, the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex of adjusted solid content concentration) A dispersion consisting of 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), and after mixing 8.66 parts, an appropriate amount of 5% by weight of hydroxylation An aqueous solution of potassium and deionized water were added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0. And, by putting the obtained composition for dip molding into the container so as to be less than a half of the volume of the container, and not covering the lid, an environment having contact with the outside air is obtained. It was aged at 30 ° C. for 1 day.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例３と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例３と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 3 except that the dip molding composition thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 3.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２未満の量にて、かつ、蓋をしないことで、外気との接触が有る環境にして、１日間３０℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得て、実施例１と同様にして各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is brought into contact with the open air in the same container, in an amount less than 1/2 of the container volume, and not covered. The dip-formed product for evaluation is obtained by performing dip-forming under the same conditions again using the dip-forming composition after storage at 30 ° C. for 1 day in an environment where Each measurement was performed in the same manner as in. The results are shown in Table 2.
＜比較例２＞
　製造例１で得られたカルボキシル基含有ニトリルゴムのラテックスに、脱窒菌を培養した培地を浸漬させ、１日室温で保管することで、脱窒菌をラテックス中で繁殖させた。脱窒菌数を上記方法にて測定したところ、１．０×１０６（ＣＦＵ／ｍｌ）以上であった。次いで、脱窒菌を繁殖させたラテックスを、固形分濃度９重量％に調整し、次いで、固形分濃度を調整したラテックス中の固形分１００部に対して、加硫剤分散液（硫黄１部、酸化亜鉛１．５部、ジエチルカルバミン酸亜鉛０．５部、水酸化カリウム０．０３部および水５．６３部からなる分散液）８．６６部を混合した後、適量の５重量％水酸化カリウム水溶液、脱イオン水を加えて、固形分濃度９重量％、ｐＨ１０．０のディップ成形用組成物を得た。そして、得られたディップ成形用組成物を、容器体積に対して１／２以上の量となるように、容器中に入れ、蓋をすることで、外気との接触が無い環境にして、３０℃で１日間熟成させた。 Comparative Example 2
The medium in which the denitrifying bacteria were cultured was immersed in the latex of the carboxyl group-containing nitrile rubber obtained in Production Example 1 and stored at room temperature for 1 day to propagate the denitrifying bacteria in the latex. The number of denitrifying bacteria was measured by the above method and found to be 1.0 × 10 6 (CFU / ml) or more. Next, the latex in which the denitrifying bacteria is propagated is adjusted to a solid content concentration of 9% by weight, and then the vulcanizing agent dispersion (1 part of sulfur, with respect to 100 parts of solid content in the latex of adjusted solid content concentration) A dispersion consisting of 1.5 parts of zinc oxide, 0.5 parts of zinc diethylcarbamate, 0.03 parts of potassium hydroxide and 5.63 parts of water), and after mixing 8.66 parts, an appropriate amount of 5% by weight of hydroxylation An aqueous solution of potassium and deionized water were added to obtain a dip molding composition having a solid concentration of 9% by weight and a pH of 10.0. Then, the obtained dip molding composition is placed in a container so that the amount thereof is 1/2 or more of the volume of the container, and the container is covered to provide an environment free from contact with the outside air, Aging was carried out for 1 day at ° C.
　そして、このようにして得られたディップ成形用組成物を用いた以外は、参考例３と同様にして、５０回のディップ成形を行った。なお、５０回のディップ成形を行った後のディップ成形用組成物の硝酸イオン量は、参考例３と同程度であると考えられる。 Then, 50 dip moldings were performed in the same manner as in Reference Example 3 except that the dip molding composition thus obtained was used. The nitrate ion content of the dip molding composition after 50 dip moldings is considered to be similar to that of Reference Example 3.
　次いで、５０回のディップ成形を行った後のディップ成形用組成物を、同じ容器中において、容器体積に対して１／２以上の量にて、蓋をすることで、外気との接触が無い環境にして、１日間３０℃で保管し、保管後のディップ成形用組成物を用いて、再度、同じ条件でディップ成形を行うことで、評価用ディップ成形体を得て、実施例１と同様にして各測定を行った。結果を表２に示す。 Subsequently, the dip molding composition after 50 times of dip molding is covered with an amount of 1/2 or more of the container volume in the same container, so that there is no contact with the open air. In an environment, stored at 30 ° C. for 1 day, and using the dip molding composition after storage, dip molding is performed again under the same conditions to obtain a dip molded article for evaluation, as in Example 1. Each measurement was performed. The results are shown in Table 2.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１に、参考例１～３のディップ成形条件、および測定結果を、表２に、実施例１～５、比較例１，２のディップ成形条件、保管条件、および測定結果をそれぞれ示す。 Table 1 shows the dip molding conditions of Reference Examples 1 to 3 and the measurement results, and Table 2 shows the dip molding conditions, storage conditions and measurement results of Examples 1 to 5 and Comparative Examples 1 and 2.
　表２に示すように、硝酸イオンの量（５０回のディップ成形を行った後における硝酸イオンの量）を１０重量ｐｐｍ以下、または、保管後の脱窒菌の量を１．０×１０５（ＣＦＵ／ｍｌ）以下とした実施例１～５においては、亜硝酸イオンの量（保管後の亜硝酸イオンの量）を１０重量ｐｐｍ以下に制御することでき、得られるディップ成形体の黄色度（ＹＩ）は低く抑えられており、黄変が適切に防止されたものであった。 As shown in Table 2, the amount of nitrate ion (the amount of nitrate ion after 50 times of dip molding) is 10 ppm by weight or less, or the amount of denitrifying bacteria after storage is 1.0 × 10 5 ( In Examples 1 to 5 in which the CFU / ml) or less was used, the amount of nitrite ion (the amount of nitrite ion after storage) could be controlled to 10 ppm by weight or less, and the yellowness of the resulting dip-formed product ( YI) was kept low and yellowing was properly prevented.
　一方、硝酸イオンの量（５０回のディップ成形を行った後における硝酸イオンの量）が１０重量ｐｐｍ超であり、かつ、保管後の脱窒菌が１．０×１０５（ＣＦＵ／ｍｌ）超であった比較例１，２は、亜硝酸イオンの量が１０重量ｐｐｍ超となり、得られるディップ成形体の黄色度（ＹＩ）は高くなってしまい、黄変が発生する結果となった。 On the other hand, the amount of nitrate ion (the amount of nitrate ion after 50 times of dip molding) is more than 10 ppm by weight, and the denitrifying bacteria after storage is more than 1.0 × 10 5 (CFU / ml) In Comparative Examples 1 and 2 in which the amount of nitrite ion was more than 10 ppm by weight, the degree of yellowness (YI) of the resulting dip-formed product became high, and yellowing occurred.
　なお、本実施例、比較例においては、上記（２）のように、ディップ成形用組成物を用いて、ディップ成形体の製造を行った後、ディップ成形用組成物を一度保管し、保管したディップ成形用組成物を、再度使用してディップ成形体を製造した際における評価を行ったが、実施例１～３，５における保管環境において、ディップ成形を繰り返し行うことで、複数のディップ成形体を得た場合にも、実施例１～３，５と同等の結果が得られると考えることができることから、上記（１）のように、ディップ成形用組成物を繰り返し使用して、複数のディップ成形体を繰り返し製造した場合においても同様の結果が得られるということができる。 In the examples and comparative examples, as described in (2) above, after the dip-formed product was manufactured using the dip-forming composition, the dip-forming composition was once stored and stored. The dip molding composition was used again to evaluate a dip molded product, but a plurality of dip molded products were repeatedly subjected to dip molding in the storage environment in Examples 1 to 3 and 5. Since it can be considered that the same results as in Examples 1 to 3 and 5 can be obtained even in the case of obtaining the above, as described in (1) above, the dip molding composition is repeatedly used to make a plurality of dips. It can be said that similar results can be obtained even when the molded body is repeatedly manufactured.

Claims (7)

  1. 　重合体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することで、ディップ成形体を製造する方法であって、
    　凝固塩として硝酸塩を用いるとともに、
    　前記ディップ成形用組成物中における亜硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にてディップ成形を行うことを特徴とするディップ成形体の製造方法。     A method of producing a dip-formed product by dip-forming a dip-forming composition containing a polymer latex,
    In addition to using nitrate as the coagulating salt,
    A method for producing a dip-formed product, comprising performing dip-forming under the condition that the amount of nitrite ion in the composition for dip-forming is controlled to 10 ppm by weight or less.
  2. 　前記ディップ成形用組成物中における硝酸イオンの量を１０重量ｐｐｍ以下に制御した条件にてディップ成形を行う請求項１に記載のディップ成形体の製造方法。 The method for producing a dip-formed product according to claim 1, wherein the dip-forming is performed under the condition that the amount of nitrate ion in the composition for dip-forming is controlled to 10 ppm by weight or less.
  3. 　前記ディップ成形用組成物中における脱窒菌の量を１．０×１０５（ＣＦＵ／ｍｌ）以下に制御した条件にてディップ成形を行う請求項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 product according to claim 1 or 2, wherein the dip-forming is performed under the condition that the amount of denitrifying bacteria in the composition for dip-forming is controlled to 1.0 × 10 5 (CFU / ml) or less.
  4. 　前記ディップ成形用組成物を保管する際における保管温度を０～１８℃の範囲とする請求項１～３のいず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 product according to any one of claims 1 to 3, wherein the storage temperature at the time of storing the dip-forming composition is in the range of 0 to 18 属 C.
  5. 　凝固塩として硝酸塩を用いたディップ成形に使用した履歴を有するディップ成形用組成物を用いる請求項１～４のいず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 product according to any one of claims 1 to 4, wherein the dip-forming composition having a history used for dip-forming using nitrate as the coagulated salt is used.
  6. 　前記ディップ成形用組成物の固形分濃度が、３．０～５０重量％である請求項１～５のいず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 product according to any one of claims 1 to 5, wherein a solid content concentration of the composition for dip molding is 3.0 to 50% by weight.
  7. 　前記重合体ラテックスを構成する重合体が、ニトリルゴムである請求項１～６のいず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 product according to any one of claims 1 to 6, wherein the polymer constituting the polymer latex is a nitrile rubber.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002241412A (en) * 2000-12-12 2002-08-28 Takeda Chem Ind Ltd Latex for dip forming and dip formed material
JP2006321954A (en) * 2005-05-20 2006-11-30 Nippon Zeon Co Ltd Dip molded article
JP2011231433A (en) * 2010-04-28 2011-11-17 Showa Glove Kk Slip-resistant glove and method for producing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002241412A (en) * 2000-12-12 2002-08-28 Takeda Chem Ind Ltd Latex for dip forming and dip formed material
JP2006321954A (en) * 2005-05-20 2006-11-30 Nippon Zeon Co Ltd Dip molded article
JP2011231433A (en) * 2010-04-28 2011-11-17 Showa Glove Kk Slip-resistant glove and method for producing the same

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