Chlorosulfonated polyolefin latex

Abstract

Provided is a method whereby a chlorosulfonated polyolefin latex can be coagulated using a general coagulator. Specifically, provided is a chlorosulfonated polyolefin latex containing: an aqueous dispersion medium; a chlorosulfonated polyolefin; at least one compound selected from the group consisting of an alkylbenzene sulfonate, a polyoxyalkylene disulfonate, and a taurine salt (first agent); and a fatty acid salt (second agent).

Description

Technical Field

[0001] This invention relates to chlorosulfonated polyolefin latex, its uses, etc. More specifically, this invention relates to a solidifiable chlorosulfonated polyolefin latex, an impregnation molding composition using the latex, and an impregnation molded article. Background Technology

[0002] Chlorosulfonated polyolefins exhibit excellent heat resistance, weather resistance, ozone resistance, chemical resistance, and abrasion resistance, and are used as coating materials and adhesives in latex form. Patent Document 1 discloses a resorcinol-formaldehyde-latex adhesive (RFL adhesive) using chlorosulfonated polyethylene latex as a latex component in a conductive belt formed by compounding an ethylene-propylene-diene rubber matrix and polyester fibers, for bonding the matrix rubber to the fibers.

[0003] Furthermore, chlorosulfonated polyolefins exhibit excellent resistance to strong acids and alkalis, and are therefore used as raw materials for protective gloves in work processes involving highly hazardous chemicals, such as plating, semiconductor manufacturing, and dyeing. Chlorosulfonated polyolefin gloves are typically manufactured by immersing a hand mold corresponding to the glove's three-dimensional shape in an organic solvent solution of rubber, followed by drying and vulcanization (e.g., Patent Document 2). However, from an environmental perspective, organic solvent solutions are undesirable; therefore, it is desirable to manufacture gloves using chlorosulfonated polyolefin latex, thereby eliminating the need for organic solvents during glove manufacturing.

[0004] Typically, the coagulation impregnation method is widely used as a method for manufacturing rubber gloves from latex. For example, Patent Document 3 discloses a method in which a hand mold corresponding to the three-dimensional shape of a glove is prepared, the surface of the hand mold is treated with a coagulant such as an aqueous solution of calcium nitrate, and then the treated hand mold is impregnated in an impregnation solution containing nitrile rubber latex, causing rubber particles to adhere to the surface of the hand mold, followed by drying and cross-linking, thereby manufacturing a glove. Additionally, Patent Document 4 discloses a method of manufacturing gloves by heat-sensitizing chlorosulfonated polyethylene latex and then using a heat-sensitive coagulation method.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-003991

[0008] Patent Document 2: Japanese Patent Application Publication No. 05-230702

[0009] Patent Document 3: International Publication No. 2015 / 146974

[0010] Patent Document 4: Japanese Patent Application Publication No. 2011-032590 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] As described in Patent Document 4 (especially paragraphs 0008-0009, etc.), conventional chlorosulfonated polyolefin latexes do not coagulate even when using common coagulants (such as calcium salts), making it difficult to form a film useful as a glove.

[0013] Therefore, the inventors have conducted research in order to provide a method that can coagulate even chlorosulfonated polyolefin latex using common coagulants.

[0014] Methods for solving problems

[0015] This invention includes the subject matter described in, for example, the following items.

[0016] <Item 1>

[0017] A chlorosulfonated polyolefin latex, comprising:

[0018] Aqueous dispersion media;

[0019] Chlorosulfonated polyolefins;

[0020] At least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurines (first agent); and

[0021] Fatty acid salts (second agent).

[0022] <Item 2-1>

[0023] According to the latex described in item 1, the taurine is a compound represented by the formula: RN(CH3)-(CH2)2-SO3M.

[0024] (In the formula, R represents a cocoyl group or an acyl group with 8 to 18 carbon atoms, and M represents an alkali metal (preferably sodium or potassium), ammonium (NH4), or triethanolamine (NH(CH2CH2OH)3).)

[0025] <Item 2-2>

[0026] According to item 1 or 2-1, the latex contains alkylbenzene sulfonate as C8 to 18 alkylbenzene sulfonate.

[0027] <Item 2-3>

[0028] According to item 1, 2-1 or 2-2, the latex contains polyoxyethylene disulfonate as a salt of an ester formed by sulfation of the hydroxyl groups at both ends of a polyalkylene glycol, which is polymerized from C2-4 alkylene glycols.

[0029] <Item 3>

[0030] The latex according to any one of items 1 and 2-1 to 2-3, wherein the mass ratio of the first agent to the second agent is 0.5 to 5.

[0031] <Item 4>

[0032] The latex according to any one of items 1, 2-1 to 2-3 and 3, wherein the combined amount of the first agent and the second agent is 3 to 8 parts by mass relative to 100 parts by mass of chlorosulfonated polyolefin.

[0033] <Item 5>

[0034] The latex according to any one of items 1, 2-1 to 2-3 and 3 to 4, wherein the second agent is at least one selected from the group consisting of laurate, myristate and oleate.

[0035] <Item 6>

[0036] A method for manufacturing a chlorosulfonated polyolefin latex, comprising:

[0037] An emulsification process, wherein a chlorosulfonated polyolefin dissolved in an organic solvent is dispersed in an aqueous dispersion medium in the presence of at least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurines (first agent) and a fatty acid salt (second agent) to prepare an emulsion; and

[0038] The solvent removal process involves removing the organic solvent from the emulsion.

[0039] <Item 7>

[0040] A composition for emulsifying chlorosulfonated polyolefins, comprising:

[0041] At least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurines; and

[0042] Fatty acid salts.

[0043] <Item 8>

[0044] An impregnation molding composition comprising any one of items 1, 2-1 to 2-3 and 3 to 5, of which chlorosulfonated polyolefin latex is provided.

[0045] <Item 9>

[0046] An impregnation molded body, which is an impregnation molded body formed by impregnating the impregnation molding composition described in item 8.

[0047] Invention Effects

[0048] A chlorosulfonated polyolefin latex with excellent stability can be obtained and can be used in general coagulation impregnation methods. In addition, by using this latex, impregnated molded articles can be manufactured efficiently. Detailed Implementation

[0049] The various embodiments of the present invention will be described in more detail below. The present invention preferably includes chlorosulfonated polyolefin latex containing a specific emulsifier, its uses, and manufacturing methods, but is not limited thereto. The present invention includes all the contents disclosed in this specification and that can be recognized by those skilled in the art.

[0050] The chlorosulfonated polyolefin latex contained in this invention comprises: an aqueous dispersion medium; a chlorosulfonated polyolefin; at least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurates; and a fatty acid salt. The chlorosulfonated polyolefin latex contained in this invention is sometimes referred to as "the latex of this invention." Additionally, at least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurates is sometimes referred to as "the first agent," and the fatty acid salt as "the second agent." Both the first and second agents are compounds that can function as emulsifiers; by using them in combination, a good chlorosulfonated polyolefin latex can be prepared.

[0051] Chlorosulfonated polyolefins can be obtained by chlorinating and chlorosulfonating polyolefins. Examples of polyolefins include polymers or copolymers of α-olefins, copolymers of α-olefins with other polymerizable components, etc.

[0052] Examples of α-olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. Other polymerizable components include chain dienes such as isoprene, 1,3-butadiene, 1,4-hexadiene, 1,6-octadiene, and 2-methyl-1,5-hexadiene; cyclic dienes such as 1,4-cyclohexadiene, dicyclopentadiene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, and 6-chloromethyl-5-isopropenyl-2-norbornene; and vinyl compounds such as vinyl acetate, vinyl chloride, acrylonitrile, styrene, methyl acrylate, and methyl methacrylate.

[0053] As a chlorosulfonated polyolefin, a chlorosulfonated α-olefin polymer is preferred. In a chlorosulfonated α-olefin polymer, one or more α-olefins may be used alone. When two or more α-olefins are used, ethylene is preferred as one of them.

[0054] More specifically, examples of chlorosulfonated polyolefins include chlorosulfonated polyethylene, chlorosulfonated ethylene-α-olefin copolymers, and chlorosulfonated α-olefin polymers. It should be noted that "α-olefin" in chlorosulfonated ethylene-α-olefin copolymers and chlorosulfonated α-olefin polymers refers to α-olefins other than ethylene. Propylene is a preferred example of an α-olefin other than ethylene. That is, chlorosulfonated ethylene-α-olefin copolymers are preferably exemplified by chlorosulfonated ethylene-propylene copolymers, and chlorosulfonated propylene polymers are preferably exemplified by chlorosulfonated α-olefin polymers.

[0055] Chlorosulfonated polyolefins can be used alone or in combination with two or more.

[0056] Furthermore, the sulfur content in the chlorosulfonated polyolefin is preferably 0.5% by mass or more, more preferably 0.8% by mass or more. It is also preferably 2.0% by mass or less, more preferably 1.5% by mass or less. Additionally, it is preferably 0.5 to 2.0% by mass, more preferably 0.8 to 1.5% by mass.

[0057] The chlorine content in the chlorosulfonated polyolefin of the present invention is not particularly limited, but is preferably 10% by mass or more, more preferably 20% by mass or more. Furthermore, it is preferably 50% by mass or less, more preferably 40% by mass or less. Additionally, it is preferably 10 to 50% by mass, more preferably 20 to 40% by mass.

[0058] The sulfur and chlorine content of chlorosulfonated polyolefins are the contents of sulfur and chlorine atoms in the chlorosulfonated polyolefins, respectively, and can be determined by the oxygen flask combustion method.

[0059] Methods for chlorinating and chlorosulfonating polyolefins include solution methods where the polyolefin is dissolved in an organic solvent and the reaction is carried out in a homogeneous system; suspension methods where the polyolefin is suspended in a solvent and the reaction is carried out; melt methods where the reaction is carried out in a molten state; and gas-phase methods where the polyolefin is suspended in a gas phase and the reaction is carried out. From the viewpoint of uniformly carrying out chlorination and chlorosulfonation, solution methods are preferred. Examples of chlorinating and chlorosulfonating agents used include the combined use of chlorine and sulfur dioxide, the combined use of chlorine and sulfonyl chloride, and the use of sulfonyl chloride alone. The chlorosulfonation reaction can be carried out by using a chlorinating agent, a chlorosulfonating agent, a free radical generator, and a co-catalyst such as pyridine, as needed.

[0060] Commercially available chlorosulfonated polyolefins can be used. Examples of commercially available products include Tosoh Corporation's trade names "TOSO-CSM" and "extos" (chlorosulfonated polyethylene).

[0061] The content of chlorosulfonated polyolefin in the latex of the present invention is not particularly limited, for example preferably about 20% to about 60% by mass, more preferably about 25% to about 55% by mass or about 30% to about 50% by mass, and even more preferably about 35% to about 45% by mass.

[0062] As described above, the latex of the present invention contains at least one compound (first agent) selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates and taurates.

[0063] Alkylbenzene sulfonates are preferably C8-18 alkylbenzene sulfonates. In other words, the alkyl group contained in the alkylbenzene sulfonate is preferably a C8-18 (C8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18) alkyl group. This alkyl group can be straight-chain or branched, preferably straight-chain. Furthermore, as salts of alkylbenzene sulfonates, alkali metal salts (more specifically, such as sodium salts, potassium salts), ammonium salts, triethanolamine salts, etc., are preferred, with sodium salts being particularly preferred. More specifically, examples of alkylbenzene sulfonates include sodium dodecylbenzene sulfonate, potassium dodecylbenzene sulfonate, ammonium dodecylbenzene sulfonate, triethanolamine dodecylbenzene sulfonate, sodium decylbenzene sulfonate, sodium tetradecylbenzene sulfonate, sodium hexadecylbenzene sulfonate, sodium octadecylbenzene sulfonate, etc. Among these, sodium dodecylbenzene sulfonate is preferred from the viewpoint of easily producing latex with small particle size.

[0064] Alkylbenzene sulfonates can be prepared by sulfonating alkylbenzene and neutralizing the resulting alkylbenzene sulfonic acid with a basic compound. The alkylbenzene used as a starting material can be prepared by the Friedel-Crafts reaction of a haloalkyl group with benzene, or by reacting an olefin with benzene using hydrogen fluoride, zeolite, etc. Alkylbenzene sulfonic acid can be prepared by reacting the obtained alkylbenzene with a sulfonating agent. Examples of sulfonating agents include concentrated sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, and sulfur trioxide-Lewis base complexes. The resulting alkylbenzene sulfonic acid is then neutralized with a basic compound. Examples of basic compounds include alkali metal salts such as sodium hydroxide, potassium hydroxide, and sodium carbonate, ammonia, and triethanolamine.

[0065] Alkylbenzene sulfonates can be commercially available products, such as Kao Corporation's "Neopelex G-25" and LION SPECIALTY. The trade name of CHEMICALS Co., Ltd. is "ライポンLS-250", the trade name of Toho Chemical Industry Co., Ltd. is "ルノッ" "クスS-40TD", Nippon Emulsifier Co., Ltd.'s trade name "ニューコール210", "ニューコール220-L", The trade names of NOF Co., Ltd. are "Nilcon RK" and the trade names of Daiichi Industrial Pharmaceutical Co., Ltd. "ンS-20F", Takemoto Oil Co., Ltd.'s trade name "タケサーフA-41-B", "タケサーフA-41-S", etc.

[0066] Polyoxyalkylene disulfonate is a salt of an ester formed by esterifying the hydroxyl groups at both ends of a polyalkylene glycol with sulfate. Preferably, the polyalkylene glycol is a C2-4 alkylene glycol polymerized from polyalkylene glycols; more specifically, examples include polypropylene glycol, poly-1,2-butanediol, poly-1,3-butanediol, poly-1,4-butanediol, polyethylene glycol-propylene glycol copolymer, polyethylene glycol-1,2-butanediol copolymer, and polypropylene glycol-1,2-butanediol copolymer. In the case of a copolymer with ethylene glycol, it is preferable that the molar ratio of ethylene glycol units (E) to other glycol units (A) is less than 1, i.e., fewer ethylene glycol units than other glycol units. The copolymer can be a random copolymer or a block copolymer. The repeating units of the polyalkylene glycol are preferably 1 to 50, more preferably 5 to 40, and particularly preferably 10 to 30. Polyoxyethylene disulfonate is also preferably polyoxyethylene C2-4 ethylene disulfonate, and the number of polyoxyethylene repetitions is preferably 1-50, more preferably 5-40, and particularly preferably 10-30.

[0067] In addition, alkali metal salts (e.g., sodium salts, potassium salts) and ammonium salts are preferred as salts of polyoxyethylene disulfonate.

[0068] More specifically, examples of polyoxyethylene disulfonates include sodium polypropylene glycol disulfonate, potassium polypropylene glycol disulfonate, ammonium polypropylene glycol disulfonate, sodium polyethylene glycol-propylene glycol disulfonate, and sodium poly1,2-butanediol disulfonate. Among these, sodium polypropylene glycol disulfonate is preferred from the viewpoint of easily obtaining latex with small particle size.

[0069] Polyoxyalkylene disulfonates can be prepared by sulfatating the terminal hydroxyl groups of a polyalkylene glycol and neutralizing the resulting sulfate with an alkaline compound to form its salt. Methods for preparing polyalkylene glycols used as raw materials include ring-opening polymerization of cyclic ether compounds and dehydration condensation polymerization of ethylene glycol. Examples of polyalkylene glycols, as mentioned above, include polypropylene glycol, poly-1,2-butanediol, poly-1,3-butanediol, poly-1,4-butanediol, polyethylene glycol-propylene glycol copolymers, polyethylene glycol-1,2-butanediol copolymers, and polypropylene glycol-1,2-butanediol copolymers. In the case of copolymers with ethylene glycol, it is preferable that the molar ratio of ethylene glycol units (E) to other glycol units (A) is less than 1, i.e., fewer ethylene glycol units than other glycol units. The copolymer can be a random copolymer or a block copolymer. The repeating unit of the polyalkylene glycol is preferably 1 to 50, more preferably 5 to 40, and particularly preferably 10 to 30. As a method for sulfation, the polyalkylene glycol is dissolved in an organic solvent, and the reaction is carried out under conditions where the amount of sulfating agent used is more than twice the molar number of the polyalkylene glycol. Examples of sulfating agents include concentrated sulfuric acid, fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, and sulfur trioxide-Lewis base complexes. After sulfation, neutralization is performed with a suitable alkaline compound. Examples of alkaline compounds include alkali metal salts such as sodium hydroxide, potassium hydroxide, and sodium carbonate, ammonia, and triethanolamine.

[0070] Polyoxyethylene disulfonate can be commercially available, such as the product name "Newcole 240" from Nippon Emulsifier Co., Ltd.

[0071] Taurate salts are preferably those obtained by amidation of N-alkyl taurate salts. Other examples of taurate salts include alkali metal salts (e.g., sodium salts, potassium salts), ammonium salts, and triethanolamine salts.

[0072] As such taurine salts, compounds represented by the formula RN(CH3)-(CH2)2-SO3M are preferred.

[0073] (In the formula, R represents a cocoyl group or an acyl group with 8 to 18 carbon atoms, and M represents an alkali metal (preferably sodium or potassium), ammonium (NH4), or triethanolamine (NH(CH2CH2OH)3).)

[0074] Acyl groups with 8 to 18 carbon atoms (8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18) can be more specifically listed as lauroyl, myristyl, palmitoyl, stearoyl, oleoyl, etc.

[0075] More specifically, examples of taurine salts include sodium N-acylmethyl taurate, sodium N-lauroyl methyl taurate, sodium N-myristoyl methyl taurate, sodium N-palmitoyl methyl taurate, sodium N-stearoyl methyl taurate, sodium N-oleoyl methyl taurate, and other sodium N-acylmethyl taurate salts; or potassium N-cocoyl methyl taurate, ammonium N-cocoyl methyl taurate, triethanolamine N-cocoyl methyl taurate, sodium N-cocoyl ethyl taurate, etc. Among these, sodium N-acylmethyl taurate is preferred from the viewpoint of easily obtaining latex with small particle size.

[0076] Such taurates can be prepared, for example, by amidation of N-alkyl taurates. N-alkyl taurates can be prepared by reacting chloroethyl sulfate, bromoethyl sulfate, hydroxyethyl sulfonate, vinyl sulfonate, etc., with alkylamines. Amidation of N-alkyl taurates can be achieved by reacting the resulting N-alkyl taurate with an acyl chloride in the presence of a base, by dehydration condensation of N-alkyl taurate and fatty acid, or by reacting N-alkyl taurate with isopropylene esters of fatty acids.

[0077] Taurine salts can be commercially available products, such as those from Nikko Chemicals Co., Ltd. ("NIKKOL CMT-30", "NIKKOL LMT-30", "NIKKOL MMT", "NIKKOL PMT", "NIKKOL SMT"), Toho Chemical Industry Co., Ltd. ("Neoscop CN-30", "Neoscop CTS-25"), and Nippon Oil Co., Ltd. ("Taipon S", "Taipon LM", "Taipon K").

[0078] The latex of this invention contains fatty acid salts (second agent).

[0079] The fatty acids constituting fatty acid salts can be either saturated or unsaturated fatty acids. As unsaturated fatty acids, those having one, two, three, or four carbon double bonds are preferred, and those having one carbon double bond are more preferred. Furthermore, they can be either linear or branched. Fatty acids with 8 to 24 carbon atoms (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24) are preferred, and those with 12 to 22 carbon atoms are more preferred. More specifically, examples include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid; and unsaturated fatty acids such as myristoleic acid, palmitoleic acid, cis-6-hexadecenoic acid, oleic acid, transoleic acid, ricinoleic acid, linoleic acid, linolenic acid, codoleic acid, arachidonic acid, cetylene acid, erucic acid, and brassinolide. Additionally, as salts of fatty acids, examples include alkali metal salts (e.g., sodium salts, potassium salts), ammonium salts, and amine salts (e.g., triethanolamine salts), with salts of the specific fatty acids mentioned above being particularly preferred.

[0080] From the viewpoint of better latex stability, laurate, myristicate or oleate are preferred among these fatty acid salts, laurate or oleate are more preferred, and potassium laurate or potassium oleate are even more preferred.

[0081] Fatty acid salts can be used alone or in combination of two or more.

[0082] Fatty acid salts can be added in the form of fatty acid salts, or they can be prepared by neutralizing the aforementioned fatty acids with alkali in a latex manufacturing system. When prepared in a system, incomplete neutralization may occur, resulting in unreacted fatty acids remaining in the system. Alternatively, an excess of alkali may be added relative to the amount of fatty acids. The neutralization rate of the fatty acids is not particularly limited, but is preferably 60–400 mol%, more preferably 90–300 mol%, and even more preferably 100–200 mol%. Here, "neutralization rate 400 mol%" means neutralization with 4 equivalents of alkali of the fatty acids.

[0083] Commercially available fatty acid salts can be used, such as those from Kao Corporation ("NnS Soap", "SS-40N", "OS Soap", "KS Soap"), Nikko Chemicals Corporation ("NIKKOL Potassium Laurate LK-120", "NIKKOL Potassium Myristate MK-140", "Tai Soap MNK-40"), and Nippon Oil Corporation ("Non-Salt PK-1", "Non-Salt SK-1", "Non-Salt MK-1"). When fatty acids are used to prepare fatty acid salts, commercially available products can be used, such as those from Nippon Oil Co., Ltd. under the trade names "NAA-142", "NAA-160", "NAA-35" and "Ekistroorein", those from MIYOSHI Oils Co., Ltd. under the trade names "palmitic acid 60", "stearic acid 65" and "PM200", and those from Kao Corporation under the trade names "Lunack L-55A", "Lunack BA" and "Lunack OV".

[0084] It should be noted that, as long as it does not impair the inventive effect of the present invention, the latex of the present invention may contain emulsifiers other than the first and second agents. Examples of such emulsifiers include anionic emulsifiers such as alkyl sulfate salts and alkyl phosphate salts; nonionic emulsifiers such as polyoxyethylene alkyl ethers and glycerol fatty acid esters; and amphoteric emulsifiers such as alkyl betaine salts, sulfobetaine salts, and N-acyl amino acid salts. It should be noted that, preferably, the latex of the present invention does not contain any emulsifiers other than the first and second agents. (In other words, preferably, the latex of the present invention contains only the first and second agents as emulsifiers.)

[0085] In the latex of the present invention, the first agent preferably contains 1 to 15 parts by weight relative to 100 parts by weight of the chlorosulfonated polyolefin latex. The upper or lower limit of this range can be, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 parts by weight. More preferably, this range is 1 to 10 parts by weight, and even more preferably 2 to 5 parts by weight. When the amount of the first agent used is within this range, it is easier to obtain a latex with a small particle size, and therefore this is preferred.

[0086] Furthermore, in the latex of the present invention, the second agent preferably comprises 0.1 to 10 parts by weight relative to 100 parts by weight of the chlorosulfonated polyolefin latex. The upper or lower limit of this range can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, or 9 parts by weight. More preferably, this range is 0.2 to 7 parts by weight, and even more preferably 0.5 to 5 parts by weight. When the amount of the second agent used is within this range, it is easier to obtain a latex with excellent stability, and therefore this is preferred.

[0087] Furthermore, the ratio of the first agent to the second agent is not particularly limited, but it is preferred that the mass ratio of the first agent to the second agent is 0.5 to 5. The upper or lower limit of this range can be, for example, 1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5. For example, a more preferred range is 2 to 4. It should be noted that, further preferably, in addition to satisfying the above-mentioned content ratio of the first agent to 100 parts by mass of chlorosulfonated polyolefin latex and / or the above-mentioned content ratio of the second agent to 100 parts by mass of chlorosulfonated polyolefin latex, this ratio of the first agent to the second agent is also satisfied.

[0088] Furthermore, in the latex of the present invention, the conditions for the content ratio of the first agent and the second agent described above are met, and the total amount of the first agent and the second agent is preferably 3 to 8 parts by mass, and particularly preferably 4 to 6 parts by mass, relative to 100 parts by mass of chlorosulfonated polyolefin.

[0089] As an aqueous dispersion medium, water, which is commonly used in latex applications, is preferred. Water is not particularly limited in type; examples include tap water, deionized water, and distilled water.

[0090] The content of the aqueous dispersion medium in the latex of the present invention is not particularly limited and can be appropriately adjusted according to the amount of other components. For example, in the latex of the present invention, it is preferable to contain 60% by mass or more, more preferably 65% ​​by mass or more, or 70% by mass or more. It can also be used as the balance of components other than the aqueous dispersion medium, adjusting the content ratio of each component while making the latex 100% by mass overall.

[0091] In the latex of the present invention, the average particle size of the chlorosulfonated polyolefin is preferably 0.1 to 10 μm, more preferably 0.3 to 5.0 μm, and even more preferably 0.5 to 2.0 μm. With an average particle size of 10 μm or less, particle settling is not too rapid, and static stability is even better. With an average particle size of 0.1 μm or more, excessive latex viscosity can be suppressed, making handling easier. It should be noted that the average particle size in the present invention is the median particle size based on volume, measured using a laser diffraction particle size distribution system.

[0092] The latex of the present invention can be manufactured, for example, by means of an emulsification process and a solvent removal process. The emulsification process is a process of preparing an emulsion by dispersing a chlorosulfonated polyolefin dissolved in an organic solvent in an aqueous dispersion medium in the presence of a first agent and a second agent. The solvent removal process is a process of removing the organic solvent from the emulsion.

[0093] In the emulsification process, there are no particular limitations on the organic solvents used to dissolve chlorosulfonated polyolefins, as long as they can dissolve the polyolefins. Examples include aliphatic hydrocarbon organic solvents such as hexane, heptane, and octane; alicyclic hydrocarbon organic solvents such as cyclohexane, methylcyclohexane, and decahydronaphthalene; aromatic hydrocarbon organic solvents such as benzene, toluene, and xylene; and halogenated hydrocarbon organic solvents such as chloroform, 1,2-dichloroethane, and chlorobenzene. These organic solvents can be used individually or in combination of two or more.

[0094] The amount of organic solvent used is preferably set in such a way that the concentration of chlorosulfonated polyolefin is 3 to 20% by mass, and more preferably in a way that the concentration of chlorosulfonated polyolefin is 10 to 16% by mass. When the concentration of chlorosulfonated polyolefin is in this range, the solution is easy to handle, and in addition, it is easy to obtain latex with small particle size, so it is preferred.

[0095] The temperature at which chlorosulfonated polyolefins are dissolved in an organic solvent is preferably, for example, about 20°C to about 100°C. From the viewpoint of suppressing the hydrolysis of chlorosulfonated polyolefins (hydrolysis of chlorosulfonic acid groups), it is more preferably 40 to 80°C.

[0096] The emulsification process can be carried out in the following two ways, for example.

[0097] For example, an emulsion can be prepared by dissolving or dispersing the first and second agents in an aqueous dispersion medium, adding a chlorosulfonated polyolefin solution to the aqueous dispersion medium, and dispersing it (this emulsification process is sometimes referred to as the first method). In this method, the first and second agents function as emulsifiers. The first and second agents can be added to the aqueous dispersion medium separately, or they can be mixed and then added to the aqueous dispersion medium.

[0098] Alternatively, for example, by adding fatty acids to a chlorosulfonated polyolefin solution and mixing, dissolving, or dispersing them, and then adding this mixed solution to an aqueous dispersion medium containing a first agent and a neutralizing agent of fatty acids, an emulsion can be prepared (sometimes this emulsification process is referred to as the second method). The fatty acid used is the same as described above, used as a precursor to the second agent. Furthermore, any neutralizing agent used can act on the fatty acid to form a fatty acid salt; preferred examples include sodium hydroxide, sodium methoxide, potassium hydroxide, potassium tert-butoxide, ammonia, and triethanolamine.

[0099] Regarding the amount of aqueous dispersion medium used in the emulsification process, for example, in the first embodiment, it is preferable to set it so that the total concentration of the first agent and the second agent in the aqueous dispersion medium is 0.1% to 50% by mass. Alternatively, in the second embodiment, it is preferable to set it so that the total concentration of the first agent contained in the aqueous dispersion medium and the fatty acid salt formed from the fatty acid in the organic solvent solution and the neutralizing agent of the aqueous dispersion medium is 0.1% to 50% by mass relative to the aqueous dispersion medium.

[0100] Furthermore, in the first embodiment, the amounts of the first agent and the second agent are preferably set to 2 to 5 parts by mass and 0.5 to 4 parts by mass, respectively, relative to 100 parts by mass of the chlorosulfonated polyolefin dissolved in the organic solvent. On the other hand, in the second embodiment, the amount of the first agent is preferably set in the same manner as in the first embodiment. Additionally, the amounts of fatty acids and the neutralizing agent are preferably set in the same manner as in the first embodiment, based on the amount of fatty acid salts formed by adding the organic solvent solution to the aqueous dispersion medium.

[0101] In the preparation of the emulsion during the emulsification process, the following methods can be used: mixing using an emulsifier with appropriate shear force, such as a batch emulsifier like a homogenizer, homogenizer disperser, homogenizer, or colloid mill; mixing using a continuous emulsifier like an online homogenizer or online homogenizer; or dispersing using an ultrasonic disperser. These methods can be used individually or in combination. The temperature during the emulsification process is not particularly limited, but is preferably set to 5–70°C, more preferably 25–60°C. It should be noted that the average particle size of the chlorosulfonated polyolefin in the target chlorosulfonated polyolefin latex can also be adjusted during emulsion preparation by controlling the intensity of stirring, the frequency of ultrasound, the processing time, and the processing temperature.

[0102] In the desolventizing process, methods for removing organic solvents from the emulsion obtained from the emulsification process include, for example, distilling the emulsion under normal pressure, reduced pressure, or increased pressure; blowing steam or the like into the emulsion to evaporate and remove the organic solvent; and using a membrane that selectively allows only organic solvents to pass through to remove the organic solvent. These methods can be used individually or in combination of two or more.

[0103] In the desolventizing process, defoamers can be used to suppress foaming of the emulsion. Examples of defoamers include mineral oil-based defoamers, polysiloxane-based defoamers, acetylene-based defoamers, metal soap-based defoamers, acrylic-based defoamers, and fluorinated defoamers. Acetylene-based defoamers are preferred. They can be used alone or in combination of two or more. The amount of defoamer used also depends on the amount of emulsifier used, and is preferably 100–2000 ppmwt relative to 100 parts by weight of chlorosulfonated polyolefin. The defoamer can be added to the emulsion before the desolventizing process or added appropriately during the desolventizing process. Methods of addition include one-time addition, dripping, and spraying.

[0104] Furthermore, the emulsion after removing the organic solvent can be concentrated to the desired solids concentration as needed. Examples of concentration methods include heating, centrifugation, filtration, or wet separation. Among these, methods using a filtration membrane are preferred, and methods using an ultrafiltration membrane are more preferred, as they minimize the application of heat and stress to the emulsion and minimize damage to its stability.

[0105] The solid content of the target chlorosulfonated polyolefin latex obtained after the desolventizing process is preferably 20-60% by mass.

[0106] In the above manufacturing method, a neutralizing agent can be added to the obtained chlorosulfonated polyolefin latex to adjust the pH. Common neutralizing agents such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and monoethanolamine can be used. The neutralizing agent can be added before, during, or after the desolventizing process.

[0107] To improve the stability of the latex of the present invention, additives such as polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, butylated hydroxytoluene, 2,5-di-tert-butylhydroquinone, and bisphenol A epoxy resin can be added without impairing the inventive effect of the present invention. Such additives can be added to the prepared chlorosulfonated polyolefin latex, or, depending on the type of additive, to the organic solvent solution or aqueous dispersion medium used in the emulsification process during the preparation of the chlorosulfonated polyolefin latex. It should be noted that these additives are generally preferably added in the form of aqueous solutions or aqueous dispersions, either alone or in mixtures. When additives are added, the total amount is preferably about 0.1 to about 10 parts by weight relative to 100 parts by weight of the chlorosulfonated polyolefin.

[0108] Furthermore, the present invention also includes a composition for emulsifying chlorosulfonated polyolefins, which is a composition containing a first agent and a second agent. This composition for emulsifying chlorosulfonated polyolefins is sometimes referred to as the emulsifying composition of the present invention. The emulsifying composition of the present invention contains a first agent and a second agent, therefore, by using it to emulsify chlorosulfonated polyolefins, a chlorosulfonated polyolefin latex with excellent stability and a solidifiable consistency can be manufactured. The emulsifying composition of the present invention is preferably used to manufacture the chlorosulfonated polyolefin latex of the present invention.

[0109] Regarding the emulsifying composition of the present invention, the above description is directly applicable to the chlorosulfonated polyolefin to which emulsification is intended, the types of the first and second agents contained therein, their mass ratio, and the preferred amounts when applied to the chlorosulfonated polyolefin.

[0110] The latex of the present invention is particularly preferred for use as a composition for dip molding.

[0111] Without impairing the inventive effects of the present invention, the latex of the present invention may also contain known additives such as rheology modifiers, anti-aging agents, defoamers, pH adjusters, chelating agents, vulcanizing agents, vulcanization accelerators, vulcanization accelerator aids, acid acceptors, film-forming aids, plasticizers, fillers, and pigments. Such additives are particularly preferred when the latex of the present invention is used as a composition for dip molding.

[0112] As rheology modifiers, examples include polysaccharides such as cellulose, cellulose nanofibers, cellulose nanocrystals, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, chitin, chitosan, guar gum, xanthan gum, polyacrylic acid, sodium polyacrylate, cross-linked polyacrylic acid, polyacrylamide, polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, and other water-soluble vinyl polymers, as well as clay minerals such as montmorillonite, chlorodeionite, soapstone, bedeite, and hydropyrite.

[0113] Examples of anti-aging agents include phenolic anti-aging agents such as butylated hydroxytoluene, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), and 2,5-di-tert-butylhydroquinone; amine anti-aging agents such as N-phenyl-1-naphthylamine and di(4-octylphenyl)amine; phosphorus anti-aging agents such as tri(nonylphenyl) phosphite; sulfur-based anti-aging agents such as dilauryl thiodipropionate, 2-mercaptobenzimidazole, and nickel dibutyldithiocarbamate; and bisphenol A type epoxy resins.

[0114] As defoamers, examples include oil-based defoamers, mineral oil-based defoamers, polysiloxane-based defoamers, and polyether-based defoamers.

[0115] Examples of pH adjusters include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia, trimethylamine, triethanolamine, hydrochloric acid, sulfuric acid, phosphoric acid, citric acid, and acetic acid.

[0116] Examples of chelating agents include ethylenediaminetetraacetic acid, hypozinotriacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, bis(aminoethyl) glycol ether-N,N,N',N'-tetraacetic acid, N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid, dihydroxyethylglycine, 1-hydroxyethane-1,1-diphosphonic acid, gluconic acid, citric acid, malic acid, and tartaric acid.

[0117] As vulcanizing agents, examples include powdered sulfur, sulfur bloom, precipitated sulfur, colloidal sulfur, and other sulfur compounds; organic peroxides such as di-tert-butyl peroxide and dicumyl peroxide; maleimide compounds such as N,N'-m-phenylene bismaleimide; quinone compounds such as p-quinone dioxime and p,p'-dibenzoylquinone dioxime; metal compounds such as magnesium oxide and lead oxide; and polyol compounds such as pentaerythritol, dipentaerythritol, sorbitol, and trimethylolpropane.

[0118] Examples of vulcanization accelerators include diethyldithiocarbamate, dibutyldithiocarbamate, diphenyldithiocarbamate, sodium diethyldithiocarbamate, sodium dibutyldithiocarbamate, sodium diphenyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc diphenyldithiocarbamate, 2-mercaptobenzothiazole, zinc 2-mercaptobenzothiazole, and dibenzothiazole disulfide. 2-(4'-morpholinodithio)benzothiazole, trimethylthiourea, N,N'-diethylthiourea, 1,3-diphenylguanidine, 1,3-di-o-tolylguanidine, N-cyclohexyl-2-benzothiazole sulfenamide, N-oxodiethylene-2-benzothiazole sulfenamide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram tetrasulfide, zinc isopropyl xanthionate, etc.

[0119] Examples of accelerators for vulcanization include metal oxides such as zinc oxide and magnesium oxide, and fatty acids such as stearic acid and palmitic acid.

[0120] Examples of acid acceptors include metal oxides such as lead oxide, magnesium oxide, zinc oxide, and calcium oxide; metal hydroxides such as magnesium hydroxide, calcium hydroxide, and aluminum hydroxide; clay minerals such as hydrotalcite; and epoxy compounds such as phenyl glycidyl ether, bisphenol A diglycidyl ether, epoxidized soybean oil, epoxidized linseed oil, epoxidized polybutadiene, and polyglycidyl methacrylate.

[0121] Examples of film-forming aids include propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono-tert-butyl ether, ethylene glycol monophenyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol mono-tert-butyl ether, diethylene glycol monophenyl ether, diethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, etc.

[0122] Examples of plasticizers include phthalates, adipates, glyceryl fatty acid esters, polyether polyols, and polyester polyols.

[0123] Examples of fillers include carbon fiber, cellulose fiber, carbon black, silica, talc, clay, calcium carbonate, titanium dioxide, and barium sulfate.

[0124] As pigments, examples include carbon black, titanium dioxide, chromium oxide, Prussian blue, amber, nickel titanium yellow, chrome green, cobalt blue, phthalocyanine blue, phthalocyanine green, molybdenum orange, chrome yellow, anthraquinone, and quinacridone.

[0125] When additives are present, the amount of additives contained in the latex of the present invention is not particularly limited, but is preferably 5 to 30 parts by mass relative to 100 parts by mass of the solid component (i.e., chlorosulfonated polyolefin) in the latex composition.

[0126] Furthermore, when using the latex of the present invention as a composition for dip molding, other rubber latexes may be included without impairing the effect. Examples of such other latexes include, for instance, natural rubber latex, isoprene rubber latex, butadiene rubber latex, chloroprene rubber latex, butyl rubber latex, styrene-butadiene rubber latex, acrylic rubber latex, acrylonitrile-butadiene rubber latex, silicone rubber latex, fluororubber latex, epichlorohydrin rubber latex, and olefin rubber latex. Regarding the content of these various rubber latexes combined with the latex of the present invention in a composition for dip molding, it is preferable that the content of the other rubbers is less than the content of the chlorosulfonated polyolefin, for example, preferably 50 parts by weight or less, 40 parts by weight or less, 30 parts by weight or less, 20 parts by weight or less, 10 parts by weight or less, or 5 parts by weight or less, relative to 100 parts by weight of the chlorosulfonated polyolefin.

[0127] There are no particular limitations on the method for preparing such a composition for impregnation molding, and examples include: a method of mixing various additives in the above-mentioned chlorosulfonated polyolefin latex using a disperser such as a ball mill, bead mill, kneader, or disperser; a method of preparing an aqueous dispersion of the desired additive in advance using a disperser, and then mixing the aqueous dispersion with the chlorosulfonated polyolefin latex; and a method of mixing a portion of the additives into the chlorosulfonated polyolefin latex, and then mixing it with an aqueous dispersion of other additives, etc.

[0128] The pH of the latex of the present invention (especially when used as a composition for impregnation molding) is preferably 5 or more, and more preferably 7 to 12.

[0129] When the latex of the present invention is used as a composition for dip molding, it can be cured (also called pre-vulcanization) before being supplied for dip molding. The curing time also depends on the type of additive and the curing temperature, so it cannot be generalized, but is preferably 1 to 7 days, more preferably 1 to 3 days. In addition, the curing temperature is preferably 10 to 50°C, more preferably 20 to 40°C.

[0130] After curing, it is preferably stored at a temperature below 30°C before being used for impregnation molding.

[0131] The present invention also includes dip-molded articles obtained by using the latex of the present invention as a dip-molded article composition.

[0132] Dip molding is a method in which a mold (molding mold) is immersed in a dip molding composition, causing the composition to deposit on the surface of the mold, the mold is then lifted from the composition, and the composition deposited on the surface of the mold is dried. The method for preparing dip-molded articles of the present invention is described in more detail below.

[0133] The mold used in dip molding can be a single piece made of ceramic, metal, glass, plastic, or other materials, corresponding to the desired three-dimensional shape. The surface of the mold can be finished to resemble a pear skin, or made of other raw materials such as fibers or other types of rubber films, depending on the purpose of the dip-molded body. Furthermore, the mold can be preheated before being dipped into the dip molding composition.

[0134] Before immersing the mold in the dip-molding composition, or after removing the mold from the dip-molding composition, a coagulant is preferably used to coagulate the solid component (hereinafter sometimes simply referred to as the rubber component) with chlorosulfonated polyolefin as the main component. Methods of using the coagulant include: immersing the mold before immersion in the dip-molding composition into a solution of the coagulant (hereinafter also referred to as the coagulating liquid) to allow the coagulant to adhere to the mold; and immersing the mold with the dip-molding composition deposited on it into the coagulating liquid. From the viewpoint of obtaining a dip-molded body with less thickness unevenness, the method of immersing the mold before immersion in the dip-molding composition into a solution of the coagulant to allow the coagulant to adhere to the mold is preferred.

[0135] Metal salts can be used as coagulants, with water-soluble metal salts being more preferred. Among metal salts, from the viewpoint of high coagulation power, polyvalent metal salts that generate polyvalent metal ions are preferred, and water-soluble polyvalent metal salts are even more preferred. Examples of water-soluble metal salts include metal halides such as sodium chloride, potassium chloride, barium chloride, calcium chloride, magnesium chloride, zinc chloride, and aluminum chloride; metal nitrates such as sodium nitrate, potassium nitrate, barium nitrate, calcium nitrate, zinc nitrate, and aluminum nitrate; metal acetates such as sodium acetate, potassium acetate, barium acetate, calcium acetate, zinc acetate, and aluminum acetate; and water-soluble metal sulfates such as sodium sulfate, potassium sulfate, calcium sulfate, magnesium sulfate, and aluminum sulfate. Alkaline earth metals are preferred as polyvalent metals, with calcium, barium, and magnesium being more preferred, and calcium being the most preferred. Furthermore, from the viewpoint of high solubility in water, calcium chloride and calcium nitrate are particularly preferred as coagulants. These coagulants can be used alone or in combination of two or more.

[0136] The coagulant is preferably used in the form of an aqueous solution. This aqueous solution may also contain water-soluble organic solvents such as methanol and ethanol, and nonionic surfactants. The concentration of the coagulant is not particularly limited, but is preferably 5-50% by mass, more preferably 10-40% by mass, and particularly preferably 15-35% by mass. The immersion time of the molding die in the coagulant is not particularly limited, but is generally preferably 5-300 seconds, more preferably 10-100 seconds.

[0137] After immersing the molding die in the coagulating liquid to allow the liquid to adhere to its surface, the solvent in the coagulating liquid can be removed by drying. The drying temperature can be appropriately set depending on the type of solvent and salt used, preferably 60–150°C, more preferably 80–120°C. Furthermore, the drying time is not particularly limited, preferably 1–600 seconds, more preferably 5–300 seconds. By drying the coagulating liquid on the surface of the molding die, it is easy to form a state where salt is uniformly adhered to the surface of the molding die.

[0138] The time for immersing the molding die in the latex (implant molding composition) of the present invention can be appropriately set according to the desired thickness (film thickness), preferably 5 to 600 seconds, more preferably 10 to 300 seconds.

[0139] After the molding die is lifted from the dip-molding composition, it is usually heated to dry the solidified film formed on the die surface. The drying method is not particularly limited; hot air heating devices, infrared heating devices, microwave heating devices, high-frequency heating devices, etc., can be used. The drying temperature is not particularly limited, but is preferably 50–160°C, more preferably 60–140°C, and particularly preferably 70–120°C. Furthermore, the drying time is not particularly limited, but is preferably 1–120 minutes, more preferably 10–100 minutes, and particularly preferably 20–60 minutes.

[0140] Alternatively, further heating can be applied as needed to vulcanize the solidified film formed on the mold surface. The heating conditions during vulcanization are not particularly limited, but 60–200°C is preferred, more preferably 80–180°C, and particularly preferably 100–160°C. By maintaining the heating temperature within this range, a suitable vulcanization rate can be achieved while suppressing the deterioration of the rubber components caused by excessive heating. The heating time for vulcanization can be appropriately selected based on the heating temperature, typically ranging from 5 to 120 minutes. The heating method can, for example, be the same as the heating method described above.

[0141] In addition, before or after heating the mold on which the impregnation molding composition has been deposited, it is preferable to clean the mold with water or warm water to remove water-soluble impurities (e.g., residual emulsifier, surfactant, coagulant, uncured latex, etc.). The temperature of the water or warm water used is preferably 20 to 80°C, more preferably 30 to 70°C. The cleaning time is preferably about 0.5 minutes to about 60 minutes.

[0142] After drying (and further vulcanization as needed), the dipped molded body is removed from the molding die. Methods of removal include peeling by hand, peeling using a peeling roller, and peeling using water pressure or compressed air pressure. After removal from the die, the dipped molded body can be further washed. Furthermore, as needed, to prevent adhesion between the contact surfaces of the dipped molded bodies and improve smoothness during loading and unloading, inorganic microparticles such as talc or calcium carbonate, or organic microparticles such as corn starch, can be coated on the surface; or an elastomer layer containing microparticles can be further formed on the surface; or the surface layer can be chlorinated.

[0143] The resulting impregnated molded body has a film thickness preferably of 0.1 to 2 mm, more preferably 0.2 to 1.5 mm, and particularly preferably 0.3 to 1.0 mm. As described above, the film thickness can be appropriately set according to the impregnation time, etc.

[0144] It should be noted that, in this specification, "comprising" also includes "consisting essentially of" and "consisting of." Furthermore, this invention encompasses all arbitrary combinations of the technical features described in this specification.

[0145] Furthermore, the various characteristics (properties, structures, functions, etc.) described in the above embodiments of the present invention can be arbitrarily combined when determining the subject matter encompassed by the present invention. That is, the present invention includes all combinations of the various characteristics that can be combined as described in this specification.

[0146] Example

[0147] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited by these examples or any other examples.

[0148] As a chlorosulfonated polyolefin, chlorosulfonated polyethylene (TOSO-CSM, trade name: TS-320, TS-530, or CN-1500, manufactured by Tosoh Corporation) is used. The chlorine and sulfur content of these chlorosulfonated polyethylenes (CSM rubbers) are as follows.

[0149] TS-320: Chlorine content 23% by mass, sulfur content 1.0% by mass

[0150] TS-530: Chlorine content 35% by mass, sulfur content 1.0% by mass

[0151] CN-1500: Chlorine content 30% by mass, sulfur content 1.4% by mass

[0152] The following lists the emulsifiers (containing fatty acids as precursors) used in the examples and comparative examples.

[0153] A: Sodium alkyl (C10-16)benzenesulfonate (manufactured by Nippon Oil Co., Ltd., trade name "Newrex R", solid content concentration 50% by mass)

[0154] B: Sodium N-acylmethyl taurate (manufactured by Nippon Oil Co., Ltd., trade name "Dyapon S", solid content concentration 13% by mass)

[0155] C: Sodium polyoxyethylene disulfonate (manufactured by Nippon Emulsifier Co., Ltd., trade name "Newco 240", solid content concentration 30% by mass)

[0156] D: Sodium N-lauroyl methyl alanine (manufactured by Nippon Oil Co., Ltd., trade name "Sofitel AS-L", solid content concentration 30% by mass)

[0157] E: Sodium lauryl sulfate (manufactured by Tokyo Chemical Industry Co., Ltd., reagent, solid content concentration 97% by mass)

[0158] F: Sodium polyoxyethylene C12,14 alkyl ether sulfate (manufactured by Nippon Oil Co., Ltd., trade name "Personal EF", solid content concentration 25% by mass)

[0159] G: Lauryl dimethylaminoacetic acid betaine (manufactured by Nichiyu Corporation, trade name "Nissannon BL", solid content concentration 35% by mass)

[0160] H: Oleic acid (manufactured by NOF Co., Ltd., trade name "Escortron")

[0161] I: Myristic acid (manufactured by KISHIDA Chemical Co., Ltd., reagent, solid component concentration 99% by mass)

[0162] J: Lauric acid (manufactured by Tokyo Chemical Industry Co., Ltd., reagent, solid component concentration 98% by mass)

[0163] The parts by mass of each emulsifier in the Examples and Comparative Examples are values ​​relative to 100 parts by mass of chlorosulfonated polyolefin (specifically chlorosulfonated polyethylene) in the chlorosulfonated polyolefin latex. The parts by mass added [phr] (per hundred rubber) in Table 1 represent this value.

[0164] It should be noted that the emulsifier concentration (solid component concentration) varies among the aforementioned emulsifier products. The mass fraction values ​​of each emulsifier in the examples are calculated based on the emulsifier dosage converted from the solid component concentration. For example, as described below, in Example 1, 3.14 g of sodium alkyl (C10-16) benzenesulfonate product (Newrex R) with a solid component concentration of 50% by mass was used as the first agent, relative to 37.8 g of chlorosulfonated polyethylene. As mentioned above, the solid component concentration of Newrex R is 50% by mass, therefore the phr of the sodium alkyl (C10-16) benzenesulfonate at this time is calculated to be 3.14 × 0.5 / 37.8 × 100 = 4.16.

[0165] In addition, in Table 1, in the column for the second agent, besides the emulsifier products H, I, and J, there is also "+KOH", which indicates that KOH is added to each of the fatty acids H to J to obtain a fatty acid salt. phr also indicates the mass parts of this fatty acid salt relative to 100 parts by mass of chlorosulfonated polyolefin (specifically chlorosulfonated polyethylene).

[0166] <Evaluation Methods>

[0167] The chlorosulfonated polyethylene latex and films obtained in the various embodiments and comparative examples were evaluated by the following methods.

[0168] (Determination of average particle size)

[0169] The average particle size of emulsions and latexes was measured using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, trade name "SALD-2300"). It should be noted that the average particle size here is the median particle size calculated based on a volume reference, where the measured particles, regardless of their shape, are considered to have a particle size of 1 μm, exhibiting a diffraction and scattering pattern identical to that of a sphere with a diameter of 1 μm.

[0170] (Stability evaluation)

[0171] The following conditions are marked as ○: during the latex manufacturing process and when the latex is left to stand at 25°C for one month and almost no aggregates are visible; △: when the latex is left to stand at 25°C for one month and aggregates are visible; ×: when a large amount of aggregates are visible during the manufacturing process.

[0172] (Evaluation of whether solidification is possible)

[0173] Cases with a film thickness of 0.1 mm or more are marked as solidified and are marked as ○, while cases with a film thickness of less than 0.1 mm are marked as not solidified and are marked as ×.

[0174] (Measurement of film thickness)

[0175] The thickness is measured near the centroid of the upper, middle and lower parts (three rectangles) when the dipped molded body is roughly divided into three parts along its length. The average of the whole is taken as the thickness of the dipped molded body.

[0176] <Example 1>

[0177] (Latex manufacturing)

[0178] 37.8 g of chlorosulfonated polyethylene (TOSO-CSM, model TS-320, manufactured by Tosoh Corporation) and 232.2 g of toluene were added to a 500 mL detachable flask and stirred at 70 °C for 6 hours to dissolve. 0.39 g of oleic acid (Ekistraolene, manufactured by Nippon Yu Co., Ltd.) was then added to prepare an organic solvent solution. Separately, 3.14 g of sodium alkylbenzene sulfonate (Newrex R, manufactured by Nippon Yu Co., Ltd.) and 0.16 g of potassium hydroxide (Kanto Chemical Co., Ltd., reagent) were dissolved in 159.45 g of water to prepare an aqueous solution.

[0179] An aqueous solution was added to the organic solvent solution, and the mixture was stirred for 12 minutes using a homogenizer (PRIMIX Co., Ltd., trade name "TK Homogenizer M type") to obtain an emulsion. The stirring speed was set to 12,000 rpm. The resulting emulsion was heated to 55°C under reduced pressure of 20 kPa, and toluene was removed by distillation. The emulsion was then concentrated using an ultrafiltration machine (ultrafiltration membrane: flat membrane type, molecular weight cutoff 200,000, material polysulfone) to achieve a solids concentration of 40%, yielding chlorosulfonated polyethylene latex. It should be noted that the solids concentration was determined by measuring the mass of the residue after drying a portion of the obtained latex at 130°C for 2 hours to remove moisture.

[0180] (Preparation of the composition for dip molding)

[0181] In the above-mentioned chlorosulfonated polyethylene latex, 3 parts by weight of sodium dibutyldithiocarbamate aqueous solution (manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name "Nocuser TP") and 10 parts by weight of tripropylene glycol monomethyl ether (manufactured by Nippon Emulsifier Co., Ltd., trade name "Metzel Propeller Rigrillol") were added and stirred until homogeneous to obtain a composition for impregnation molding.

[0182] (Manufacturing of impregnated molded parts)

[0183] A ceramic mold (boat-shaped, 10cm long x 1.5cm wide x 1cm deep) was immersed in a 35% (w / w) calcium nitrate aqueous solution for 5 seconds and dried in a blower dryer at 120°C for 5 minutes. Then, the ceramic mold was immersed in the above-mentioned impregnation molding composition for 30 seconds to allow the rubber component to adhere to the mold, and then removed from the composition. The mold was dried in a blower dryer at 100°C for 20 minutes, and then further heated at 160°C for 20 minutes for vulcanization. After cooling to room temperature, the film was peeled off the ceramic mold, and the film thickness of the resulting impregnated molded body was measured.

[0184] <Examples 2-11, Comparative Examples 1-5>

[0185] Using the types and amounts of rubber and emulsifiers listed in Table 1, except for the same procedures as in Example 1, the resulting latex and film were evaluated.

[0186] The results are summarized in Table 1.

[0187]

[0188] Furthermore, the emulsifier used as the first agent was changed to the following components, and the study was conducted under the same conditions as in Example 1. The results showed no cases where latex could be prepared (i.e., no rubber agglomeration occurred) and both stability and coagulation were zero. The results are summarized below regarding the emulsifier used as the first agent.

[0189] [Rubber agglomerates without yielding latex]

[0190] Potassium rosinate

[0191] Polystyrene / maleic anhydride semi-ester ammonium

[0192] Sodium lauryl sulfate

[0193] Sodium N-lauroyl methylalanine

[0194] Disodium alkyl sulfosuccinate

[0195] [Stability rating: ×]

[0196] Sodium dioctyl sulfosuccinate

[0197] Sodium allyl alkyl sulfosuccinate

[0198] Sodium naphthalenesulfonate-formaldehyde condensate

[0199] Potassium oleate

[0200] [Stability rating: ○, but solidification rating: ×]

[0201] Lauryl dimethylaminoacetic acid betaine

[0202] Sodium polyoxyethylene lauryl sulfate

[0203] Industrial availability

[0204] According to one aspect of the invention, a chlorosulfonated polyolefin latex with excellent stability can be obtained and can be applied to general coagulation impregnation methods. Using this latex, impregnated molded articles can be manufactured efficiently. Furthermore, since impregnated molded articles such as gloves can be obtained without using organic solvents during impregnation molding, the invention is also useful from an environmental protection perspective.

Claims

1. A chlorosulfonated polyolefin latex, comprising: Aqueous dispersion media; Chlorosulfonated polyolefins; At least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurines (first agent); and Fatty acid salts (second agent).

2. The latex according to claim 1, wherein, Alkylbenzene sulfonates are C8-18 alkylbenzene sulfonates. Polyoxyalkylene disulfonate is a salt of an ester formed by sulfation of the hydroxyl groups at both ends of a polyalkylene glycol, which is polymerized from C2-4 alkylene glycols. Taurine salts are compounds represented by the formula: RN(CH3)-(CH2)2-SO3M. In the formula, R represents cocoyl or an acyl group with 8 to 18 carbon atoms, and M represents an alkali metal (preferably sodium or potassium), ammonium (NH4) or triethanolamine (NH(CH2CH2OH)3).

3. The latex according to claim 1 or 2, wherein, The mass ratio of the first agent to the second agent is 0.5 to 5.

4. The latex according to claim 1 or 2, wherein, The combined amount of the first agent and the second agent is 3 to 8 parts by mass relative to 100 parts by mass of chlorosulfonated polyolefin.

5. The latex according to claim 1 or 2, wherein, The second agent is at least one selected from the group consisting of laurate, myristate and oleate.

6. A method for manufacturing a chlorosulfonated polyolefin latex, comprising: An emulsification process, wherein a chlorosulfonated polyolefin dissolved in an organic solvent is dispersed in an aqueous dispersion medium in the presence of at least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurines (first agent) and a fatty acid salt (second agent) to prepare an emulsion; and A solvent removal process, wherein the organic solvent is removed from the emulsion.

7. A composition for emulsifying chlorosulfonated polyolefins, comprising: At least one compound selected from the group consisting of alkylbenzene sulfonates, polyoxyethylene disulfonates, and taurines; and Fatty acid salts.

8. A composition for dip molding comprising the chlorosulfonated polyolefin latex of claim 1 or 2.

9. An impregnation molded body, which is an impregnation molded body formed by impregnating the impregnation molding composition of claim 8.

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