Anti-adhesion composition for unvulcanized rubber and its use

Abstract

The object of the present invention is to provide an anti-adhesion agent composition for unvulcanized rubber that is excellent in uniform adhesion, anti-adhesion properties, and flexibility of dry solids, and a method for producing unvulcanized rubber treated with the anti-adhesion agent composition for unvulcanized rubber. [Solution] An anti-adhesion composition for unvulcanized rubber comprising the following components (A) to (C) and satisfying the following condition 1. Ingredient (A): Alkali metal salt of fatty acid Component (B): Salt of fatty acid with a metal other than an alkali metal. Ingredient (C): Water Condition 1: The non-volatile components of the anti-adhesion agent composition for unvulcanized rubber are immersed in acetone to obtain an acetone-insoluble component (I). Then, the insoluble component (I) is immersed in methanol to obtain a methanol-insoluble component (II). The mass ratio of alkali metals and the mass ratio of metals other than alkali metals contained in the insoluble component (II) satisfy the relationship shown in formula (1) below. 0.05 ≤ (mass percentage of alkali metals) ÷ (sum of mass percentage of alkali metals and mass percentage of non-alkali metals) ≤ 0.2 Equation (1)

Description

Technical Field

[0001] The present invention relates to an anti-adhesive agent composition for unvulcanized rubber and its use.

Background Art

[0002] In the production and processing process of rubber products, unvulcanized rubber may be stacked and stored until it is transferred to the next processes such as molding and vulcanization. In this case, an anti-adhesive agent (anti-sticking agent) is used to prevent adhesion between rubbers. Conventionally, as this anti-adhesive agent, inorganic particles such as talc, mica, calcium carbonate, magnesium carbonate, bentonite, etc. have been used because of their excellent anti-sticking properties. As one of the usage methods, there is a so-called wet method such as suspending the powder of inorganic particles in water and spraying the suspension, spraying it onto the rubber in a thin stream, or immersing it in the suspension. The purpose of using water in the wet method is not only to improve workability but also to cool the rubber.

[0003] An anti-adhesive agent using such inorganic particles can impart excellent anti-sticking properties by completely drying it after adhering it to the rubber by the wet method. However, if the concentration of the suspension is too low, the wettability to the rubber surface may decrease, and there may be portions that do not adhere to the rubber surface, resulting in adhesion between rubbers. Also, if the concentration of the suspension is too high, although it has excellent anti-sticking properties between rubbers, the suspension adhering to the equipment may dry to form a very hard solid content. If this solid content re-adheres to the rubber and remains in the rubber without being crushed by the force of rollers or mixers in the subsequent processes, it may become a defective product due to foreign matter contamination, and the production efficiency may be greatly reduced. As a countermeasure against this, an anti-adhesive agent mainly composed of an organic substance that does not use inorganic particles has been developed. However, although this anti-adhesive agent has very excellent uniform adhesion properties, it has a problem of being inferior in anti-sticking properties compared to the anti-adhesive agent using inorganic particles.

[0004] Patent Document 1 discloses a method of anti-adhesion treatment for unvulcanized rubber by dispersing an anti-adhesion composition containing a specific water-soluble polymer, a metal soap, a surfactant, and water in water and applying it to unvulcanized rubber. While such an aqueous dispersion of the anti-adhesion composition applied to unvulcanized rubber exhibits excellent anti-adhesion properties upon drying, and allows for easy removal of solid anti-adhesion components that adhere to the equipment from the rubber surface, these solid components form a hard film and can cause foreign matter contamination if they reattach to the rubber surface. Patent Document 2 discloses a method of treating unvulcanized rubber by applying an anti-adhesion composition for unvulcanized rubber, which essentially contains water, fatty acid soap, metal soap, and a specific surfactant, to the unvulcanized rubber. While such anti-adhesion compositions for unvulcanized rubber are said to have excellent anti-adhesion properties and high-temperature stability, the metal soap in the composition may not adhere well to the rubber surface, resulting in reduced uniform adhesion. Therefore, there is a need for the development of anti-adhesion agents for unvulcanized rubber that offer excellent uniform adhesion, anti-adhesion properties, and flexibility of the dried solids. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-185218 [Patent Document 2] Japanese Patent Publication No. 2020-050812 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide an anti-adhesion agent composition for unvulcanized rubber that is excellent in uniform adhesion, anti-adhesion properties, and flexibility of dry solids, and a method for producing unvulcanized rubber treated with the anti-adhesion agent composition for unvulcanized rubber. [Means for solving the problem]

[0007] As a result of diligent research, the inventors discovered that the above problems can be solved with an anti-adhesion composition for unvulcanized rubber that contains specific components and satisfies specific conditions, and thus arrived at the present invention.

[0008] In other words, the anti-adhesion composition for unvulcanized rubber of the present invention includes the following embodiments. <1> An anti-adhesion composition for unvulcanized rubber, comprising the following components (A) to (C) and satisfying condition 1 below. Ingredient (A): Alkali metal salt of fatty acid Component (B): Salt of fatty acid with a metal other than an alkali metal. Ingredient (C): Water Condition 1: The non-volatile components of the anti-adhesion agent composition for unvulcanized rubber are immersed in acetone to obtain an acetone-insoluble component (I). Then, the insoluble component (I) is immersed in methanol to obtain a methanol-insoluble component (II). The mass ratio of alkali metals and the mass ratio of metals other than alkali metals contained in the insoluble component (II) satisfy the relationship shown in formula (1) below. 0.05 ≤ (mass percentage of alkali metals) ÷ (sum of mass percentage of alkali metals and mass percentage of non-alkali metals) ≤ 0.2 Equation (1) <2> The total mass ratio of component (A) and component (B) to the nonvolatile content of the anti-adhesion agent composition for unvulcanized rubber is 45% by mass or more. <1> The anti-adhesion composition for unvulcanized rubber described above. <3> The following conditions 2 are met: <1> or <2> The anti-adhesion composition for unvulcanized rubber described above. Condition 2: The mass ratio of component (A) and the mass ratio of component (B) in the nonvolatile content of the anti-adhesion agent composition for unvulcanized rubber satisfy the relationship shown in formula (2) below. (Mass ratio of component (A)) > (Mass ratio of component (B)) Equation (2) <4> The component (A) comprises an alkali metal fatty acid salt (a1) having 10 or fewer carbon atoms and an alkali metal fatty acid salt (a3) ​​having 16 or more carbon atoms, and the mass ratio (a1 / a3) of the alkali metal fatty acid salt (a1) to the alkali metal fatty acid salt (a3) ​​is 15 / 100 to 200 / 100. <1> ~ <3> An anti-adhesion composition for unvulcanized rubber as described in any of the following. <5> The following ingredient (D) is also included: <1> ~ <4> An anti-adhesion composition for unvulcanized rubber as described in any of the following. Ingredient (D): Nonionic surfactant <6> The above component (D) has oxyalkylene structural units, and the number of oxyalkylene structural units is 6 or more. <5> The anti-adhesion composition for unvulcanized rubber described above. <7> The following ingredient (E) is also included: <1> ~ <6> An anti-adhesion composition for unvulcanized rubber as described in any of the following. Ingredients (E): Organic polymer particles <8> <1> ~ <7> A method for producing anti-adhesion treated unvulcanized rubber, comprising the step of applying an anti-adhesion composition for unvulcanized rubber described in any of the above to the surface of unvulcanized rubber. [Effects of the Invention]

[0009] The anti-adhesion agent composition for unvulcanized rubber of the present invention exhibits excellent uniform adhesion, anti-adhesion properties, and flexibility of the dry solid content. The present invention provides a method for producing anti-adhesion treated unvulcanized rubber, which includes a step of applying the anti-adhesion agent for unvulcanized rubber to the surface of the unvulcanized rubber, and therefore offers excellent productivity in producing unvulcanized rubber with excellent uniform adhesion and anti-adhesion properties. [Modes for carrying out the invention]

[0010] The anti-adhesion composition for unvulcanized rubber of the present invention (hereinafter sometimes referred to as the anti-adhesion composition) comprises the following components (A), (B), and (C). Ingredient (A): Alkali metal salt of fatty acid Component (B): Salt of fatty acid with a metal other than an alkali metal. Ingredient (C): Water First, each component of the anti-adhesion composition of the present invention will be described, and the anti-adhesion composition will be described in detail.

[0011] [Ingredient (A)] As described above, component (A) is an alkali metal salt of a fatty acid, which imparts wettability and anti-adhesion properties, and also assists in the adhesion of the active ingredient in the anti-adhesion composition to unvulcanized rubber. It is also a component that contributes to the flexibility of the dry solids of the anti-adhesion composition. The fatty acid in component (A) may be a saturated fatty acid or an unsaturated fatty acid. Also, the fatty acid in component (A) may have a linear hydrocarbon group or a branched hydrocarbon group. The number of carbon atoms of the fatty acid in component (A) is not particularly limited, but is preferably 6 to 30, more preferably 8 to 24, and even more preferably 8 to 22. The fatty acid in component (A) is not particularly limited, and examples thereof include caproic acid, caprylic acid, 2-ethylhexanoic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, isoleic acid, linoleic acid, linolenic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, melissic acid, etc.

[0012] The alkali metals in component (A) include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr), and lithium, sodium, and potassium are preferred. Component (A) may be a single fatty acid alkali metal salt or may be composed of two or more fatty acid alkali metal salts.

[0013] Component (A) is not particularly limited, but when it contains a fatty acid alkali metal salt (a1) having 10 or less carbon atoms and a fatty acid alkali metal salt (a3) having 16 or more carbon atoms, it is preferable in that the wettability is improved and a film excellent in anti-fouling property can be formed. When component (A) contains the fatty acid alkali metal salts (a1) and (a3), the mass ratio (a1 / a3) of the fatty acid alkali metal salt (a1) to the fatty acid alkali metal (a3) is not particularly limited, but is preferably 15 / 100 to 200 / 100, more preferably 20 / 100 to 150 / 100, and even more preferably 25 / 100 to 100 / 100.

[0014] When component (A) contains fatty acid alkali metal salts (a1) and (a3), the total mass ratio of the fatty acid alkali metal salts (a1) and (a3) in component (A) is not particularly limited, but is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and particularly preferably 80% by mass or more.

[0015] When component (A) contains a fatty acid alkali metal salt (a3) having 16 or more carbon atoms, the fatty acid alkali metal salt (a3) may contain an unsaturated fatty acid alkali metal salt. It is preferable that the fatty acid alkali metal salt (a3) contains an unsaturated fatty acid alkali metal salt in that it improves the wettability to the unvulcanized rubber. The mass ratio of the unsaturated fatty acid alkali metal salt in the fatty acid alkali metal salt (a3) is not particularly limited, but is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

[0016] Component (A) may contain a fatty acid alkali metal salt (a2) having 11 to 15 carbon atoms. The mass ratio of the fatty acid alkali metal salt (a2) in component (A) is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and particularly preferably 20% by mass or less.

[0017] 〔Component (B)〕 Component (B) is a salt of a fatty acid and a metal other than an alkali metal as described above, and is a component that imparts lubricity and anti-adhesion properties. It is also a component that contributes to the flexibility of the dry solid content of the anti-adhesion agent composition. The fatty acid in component (B) is not particularly limited, and may be the same as the fatty acid in component (A). The carbon number of the fatty acid in component (B) is not particularly limited, but is preferably 6 to 30, more preferably 8 to 20, and still more preferably 10 to 18.

[0018] The metal other than an alkali metal in component (B) is not particularly limited, and may be a typical metal or a transition metal. Metals other than alkali metals are not particularly limited, but examples include alkaline earth metals such as magnesium, calcium, barium, strontium, and barium; typical metals such as aluminum, zinc, tin, and lead; transition metals such as manganese, iron, cobalt, nickel, copper, and silver; and rare earth metals. Component (B) may also be a salt of a polyvalent metal ion with a valency of 2 or higher.

[0019] There are no particular limitations on component (B), but examples include calcium caprylate, zinc caprylate, magnesium caprylate, aluminum caprylate, calcium caprate, zinc caprate, magnesium caprate, aluminum caprate, calcium laurate, zinc laurate, magnesium laurate, aluminum laurate, calcium myristate, zinc myristate, magnesium myristate, aluminum myristate, calcium palmitate, zinc palmitate, magnesium palmitate, aluminum palmitate, calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, aluminum trioctadecanoate, aluminum dioctadecanoate, aluminum monooctadecanoate, calcium octadecanoate, zinc octadecanoate, magnesium octadecanoate, aluminum octadecanoate, calcium oleate, zinc oleate, magnesium oleate, aluminum oleate, calcium behenate, zinc behenate, magnesium behenate, aluminum behenate, calcium 12-hydroxystearate M, 12-Zinc hydroxystearate, 12-Magnesium hydroxystearate, 12-Aluminum hydroxystearate, 14-Calcium octadecanoate, 14-Zinc octadecanoate, 14-Magnesium octadecanoate, 14-Aluminum octadecanoate, 8-Calcium octadecanoate, 8-Zinc octadecanoate, 8-Magnesium octadecanoate, 8-Aluminum octadecanoate, 6-Calcium octadecanoate, 6-Zinc octadecanoate, 6-Magnesium octadecanoate, 6-Aluminum octadecanoate, Coconut fat Examples include calcium carbonate, zinc coconut fatty acid, magnesium coconut fatty acid, aluminum coconut fatty acid, calcium palm oil fatty acid, zinc palm oil fatty acid, magnesium palm oil fatty acid, aluminum palm oil fatty acid, calcium palm kernel oil fatty acid, zinc palm kernel oil fatty acid, magnesium palm kernel oil fatty acid, aluminum palm kernel oil fatty acid, calcium beef tallow fatty acid, zinc beef tallow fatty acid, magnesium beef tallow fatty acid, aluminum beef tallow fatty acid, calcium castor oil fatty acid, zinc castor oil fatty acid, magnesium castor oil fatty acid, and aluminum castor oil fatty acid. Component (B) may be a salt of one fatty acid and a metal other than an alkali metal, or it may be composed of two or more such components.

[0020] [Component (C)] As mentioned above, component (C) is water. By including component (C), it is possible to uniformly adhere to the unvulcanized rubber, adjust the degree of methanol-insoluble component (II) generation under condition 1 described later, and stabilize methanol-insoluble component (II). For the water used, you may use any of the following: tap water, deionized water, distilled water, etc.

[0021] [Component (D)] The anti-adhesion composition of the present invention may further contain the following component (D). The inclusion of the following component (D) is preferable in that it improves wettability to the rubber surface. It is also preferable in that it improves the flexibility of the dry solid content of the anti-adhesion composition. Ingredient (D): Nonionic surfactant

[0022] There are no particular limitations on component (D), but examples include polyoxyalkylene alkyl ethers such as polyoxyalkylene cetyl ether and polyoxyalkylene lauryl ether; polyoxyalkylene alkylphenyl ethers such as polyoxyalkylene nonylphenyl ether, polyoxyalkylene octylphenyl ether and polyoxyalkylene styrene phenyl ether; polyoxyalkylene fatty acid esters such as polyoxyalkylene monolaurate and polyoxyalkylene monooleate; sorbitan fatty acid esters such as sorbitan monopalmitate and sorbitan monooleate; and polyoxyalkylene Examples include polyoxyalkylene sorbitan fatty acid esters such as sorbitan monostearate and polyoxyalkylene sorbitan monooleate; glycerin fatty acid esters such as glycerin monostearate, glycerin monopalmitate, and glycerin monolaurate; polyoxyalkylene sorbitol fatty acid esters; polyglycerin fatty acid esters; alkylglycerin ethers; polyoxyalkylene cholesteryl ethers; alkyl polyglucosides; sucrose fatty acid esters; polyoxyalkylene alkylamines; oxyethylene-oxypropylene block polymers, etc., and one or more of these may be used in combination.

[0023] Component (D) is not particularly limited, but it is preferable if it has an oxyalkylene structural unit in its molecule, as this imparts wettability and suppresses foaming of the anti-adhesion composition. The number of carbon atoms in the oxyalkylene structural unit is not particularly limited, but is preferably 2 to 4, more preferably 2 to 3. When component (D) has an oxyalkylene structural unit, there are no particular limitations on component (D), but it is preferable that it has an oxyethylene structural unit in order to achieve the effects of the present invention.

[0024] If component (D) has oxyalkylene structural units in its molecule, the number of such units is not particularly limited, but is preferably 2 or more, more preferably 2 to 50, even more preferably 3 to 40, and most preferably 5 to 30. Component (D) may be an alkylene oxide adduct, and the average number of added moles of alkylene oxide is not particularly limited, but is preferably 2 or more, more preferably 2 to 50, even more preferably 3 to 40, and particularly preferably 5 to 30.

[0025] The HLB of component (D) by the Griffin method is not particularly limited, but is preferably 6 to 18, more preferably 7 to 17, and even more preferably 10 to 16. When the HLB is 6 or higher, wettability tends to improve. When the HLB is 18 or lower, foaming of the anti-adhesion composition tends to be suppressed. Here, HLB by the Griffin method is a value that can be calculated based on the molecular structure using the following formula (3). In other words, HLB by the Griffin method takes a value from 0 to 20, and the smaller the value (closer to 0), the more lipophilic (hydrophobic) it is, and the larger the value (closer to 20), the more hydrophilic it is. HLB = 20 × (Sum of formula weights of hydrophilic parts / Molecular weight) Equation (3)

[0026] [Component (E)] The anti-adhesion composition of the present invention may further contain the following component (E). The inclusion of the following component (E) is preferable in that it forms a film with excellent anti-adhesion properties. Ingredients (E): Organic polymer particles

[0027] Component (E) is water-insoluble. In this invention, "water-insoluble" means that its water solubility at 20°C is less than 1 g / 100 g. There are no particular limitations on the organic polymer that constitutes component (E), but examples include thermoplastic resins and rubber. Examples of thermoplastic resins include polyolefins such as polyethylene, polypropylene, modified polyethylene, modified polypropylene, ethylene-vinyl acetate copolymer, and ethylene-(meth)acrylate copolymer; poly(meth)acrylic acid esters such as poly(meth)acrylate, poly(meth)acrylate, poly(meth)acrylate, poly(meth)acrylate, poly(meth)acrylate lauryl, poly(meth)acrylate 2-ethylhexyl, and poly(meth)acrylate stearyl; acrylonitrile-styrene copolymer (AS resin); acrylonitrile-butadiene-styrene copolymer (ABS resin); polystyrene such as polystyrene; polyamides such as nylon 6 and nylon 66; and polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytributylene terephthalate, polylactic acid, polybutylene succinate, and polyhydroxyalkanoate. There are no particular limitations on the type of rubber, but examples include natural rubber, isoprene rubber, butadiene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, silicone rubber, and ethylene-propylene-diene rubber. Organic polymers may be used individually or in combination of two or more types.

[0028] The volume-average particle diameter of component (E) is not particularly limited, but is preferably 0.1 to 50 μm, more preferably 0.12 to 20 μm, even more preferably 0.15 to 10 μm, and particularly preferably 0.2 to 5 μm. When the volume-average particle diameter is within the above range, the smoothness of the formed film tends to improve. The volume-average particle diameter refers to the volume-based D50 value measured by a laser diffraction scattering particle size distribution analyzer (for example, LA-950 manufactured by Horiba, Ltd.).

[0029] [Other ingredients] The anti-adhesion composition of the present invention may further contain, in addition to the above components (A) to (D), inorganic particles, surfactants other than components (A) and (C), polyhydric alcohols, water-soluble polymers, dispersants, defoamers, preservatives, mineral oil, oils and fats, etc. In this invention, "water-soluble" means that the solubility in water at 20°C is 1 g / 100 g or more.

[0030] (Inorganic particles) There are no particular limitations on the inorganic particles, but examples include carbonates such as calcium carbonate, magnesium carbonate, and barium carbonate; silicates such as bentonite, clay, kaolin, talc, mica, and sericite; sulfates such as calcium sulfate and barium sulfate; metal oxides such as amorphous silica, alumina, magnesium oxide, antimony trioxide, titanium oxide, white carbon, and iron oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and iron hydroxide; red iron oxide; carbon black; graphite, etc., and one or more of these may be used in combination. When the anti-adhesion composition of the present invention contains inorganic particles, its anti-adhesion properties and lubricity tend to improve.

[0031] The average particle size of the inorganic particles is not particularly limited, but in terms of adhesion to unvulcanized rubber, it is preferably 0.01 to 200 μm, more preferably 0.03 to 100 μm, even more preferably 0.05 to 50 μm, particularly preferably 0.07 to 40 μm, and most preferably 0.1 to 30 μm.

[0032] (Polyhydric alcohol) There are no particular limitations on the polyhydric alcohols, but examples include glycerin, 1,3-butanediol, propylene glycol, dipropylene glycol, polypropylene glycol, pentylene glycol, neopentyl glycol, hexylene glycol, polyethylene glycol, erythritol, pentaerythritol, dipentaerythritol, trimethylolethane, trimethylolpropane, ditrimethylolpropane, xylitol, sorbitol, mannitol, maltitol, maltotriose, glucose, sucrose, fructose, maltose, etc., and one or more of these may be used in combination. When the anti-adhesion composition of the present invention contains a polyhydric alcohol, its wettability to unvulcanized rubber tends to improve.

[0033] (Water-soluble polymer) There are no particular limitations on water-soluble polymers, but examples include starches such as wheat starch, corn starch, potato starch, sweet potato starch, tapioca starch, wheat flour starch, oxidized starch, acetic acid starch, phosphate starch, carboxymethyl starch, carboxyethyl starch, hydroxyethyl starch, positive starch, cyanoethylated starch, dialdehyde starch, phosphorylated starch, etc.; mannan; alginic acid derivatives such as alginic acid, sodium alginate, propylene glycol alginate, triethanolamine alginate, ammonium alginate, etc.; tarakanto gum, gum arabic, guar gum, xanthan gum, British gum, glucomannan, gellan gum, tara gum, locust bean gum, Examples include natural gums such as carrageenan, gelan gum, dieutan gum, tamarind gum, tamarind seed gum, tragacanth gum, ramzan gum, succinoglycan, karaya gum, and pectin; cellulose ethers such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose and their salts; proteins such as gelatin, casein, and collagen; sodium polyacrylate; polyvinyl alcohol; polyethylene glycol; polyethylene oxide; water-soluble acrylic resin; water-soluble urethane resin; water-soluble melamine resin; water-soluble epoxy resin; water-soluble butadiene resin; and water-soluble phenolic resin, and one or more of these may be used in combination. When the anti-adhesion composition of the present invention contains a water-soluble polymer, the dispersion stability of the anti-adhesion composition tends to improve, and its adhesion to unvulcanized rubber tends to improve as well.

[0034] (Dispersant) There are no particular limitations on the dispersant, but examples include salts of condensates of aromatic hydrocarbons having sulfonic acid groups, such as sodium naphthalene sulfonic acid formalin condensate, sodium alkyl diphenyl ether sulfonate, and sodium butyl naphthalene sulfonate formalin condensate. One or more of these may be used in combination. When the anti-adhesion composition of the present invention contains a dispersant, it tends to suppress the excessive generation of interactions between the hydrophobic groups and hydrophilic groups of component (A) and component (B). Furthermore, when a small amount of component (C) is included, it tends to suppress a significant increase in the viscosity of the anti-adhesion composition.

[0035] (Antifoaming agent) Examples of defoaming agents include: silicone-based defoaming agents such as polymethylsiloxane and polyether-modified silicone; oil-based defoaming agents such as castor oil, sesame oil, linseed oil, and animal and vegetable oils; fatty acid-based defoaming agents such as stearic acid, oleic acid, and palmitic acid; fatty acid ester-based defoaming agents such as isoamyl stearate, distearyl succinate, ethylene glycol distearate, and butyl stearate; polyoxyalkylene monohydrate alcohol di-t-amylphenoxyethanol, 3-heptanol, and 2-ethylethanol. Examples include alcohol-based defoamers such as xanol; ether-based defoamers such as di-t-amylphenoxyethanol, 3-heptylcellosolve, nonylcellosolve, and 3-heptylcarbitol; phosphate ester-based defoamers such as tributylphosphate and tris(butoxyethyl)phosphate; amine-based defoamers such as diamylamine; amide-based defoamers such as polyalkyleneamides and acylate polyamines; sulfate-based defoamers such as sodium lauryl sulfate; polyoxyalkylene-based defoamers; and mineral oils.

[0036] (Preservative) Examples of preservatives include thiazoles such as thiazole and 2-mercaptothiazole; thiocyanates such as methylene bisthiocyanate and ammonium thiocyanate; sulfimides such as o-benzoix sulfimide and phenylmercuric-o-benzoix sulfimide; alkyldialkylthiocarbamates such as methyldimethylthiocarbamate and ethyldiethyldithiocarbamate; thiraum sulfides such as tetramethylthiraum sulfide and tetraethylthiraum sulfide; thiraum disulfides such as tetramethylthiraum disulfide and tetraethylthiraum disulfide; dithiocarbamates such as ferric diethyldithiocarbamate and reed dimethyldithiocarbamate; sulfamides such as o-toluenesulfonamide and benzenesulfonanilide; and 1-aminonaphthyl-4-sulfonamide. Examples include aminosulfonic acids such as nic acid and 1-amino-2-naphthol-4-sulfonic acid; phenols such as pentachlorophenol and o-phenylphenol and their alkali metal salts; chloride quinones such as tetrachloro-p-benzoquinone and 2,3-dichloro-1,4-naphthoquinone; nitro group-containing compounds such as dinitrocaprylphenylcrotonate and dinitro-o-cresol; triazines such as 1,3,5-trihydroxyethylhexahydro-1,3,5-triazine and 1,3,5-triethylhexahydro-1,3,5-triazine; organic mercury compounds such as phenylmercuric phthalate and o-hydroxyphenylmercuric chloride; amines such as p-aminoazobenzene and diphenylamine; amides such as cinnamanilide; and iodine-containing compounds such as 1,3-diiodo-2-propanol.

[0037] [Anti-adhesion composition for unvulcanized rubber and method for producing the same] The anti-adhesion composition for unvulcanized rubber of the present invention contains the above components (A) to (C) and satisfies the following condition 1. Condition 1: The non-volatile components of the anti-adhesion agent composition for unvulcanized rubber are immersed in acetone to obtain an acetone-insoluble component (I). Then, the insoluble component (I) is immersed in methanol to obtain a methanol-insoluble component (II). The mass ratio of alkali metals and the mass ratio of metals other than alkali metals contained in the insoluble component (II) satisfy the relationship shown in formula (1) below. 0.05 ≤ (mass percentage of alkali metals) ÷ (sum of mass percentage of alkali metals and mass percentage of non-alkali metals) ≤ 0.2 Equation (1)

[0038] A portion of the methanol-insoluble matter (II) described in condition 1 above is thought to be obtained through the interaction of component (A) and component (B), specifically through the interaction of the hydrophobic groups of component (A) and the hydrophilic groups of component (B). A portion of this methanol-insoluble (II) contributes to uniform adhesion, adhesion prevention, and flexibility of the dry solids, and further satisfying formula (1) results in superior uniform adhesion, adhesion prevention, and flexibility of the dry solids. The numerical range of formula (1) described in condition 1 above is 0.05 to 0.2, preferably 0.06 to 0.19, and more preferably 0.07 to 0.18. If the numerical range is less than 0.05, the amount of material generated by the interaction between component (A) and component (B) will be insufficient, and the uniform adhesion of the anti-adhesion agent composition to the unvulcanized rubber will decrease. If the numerical range is greater than 0.2, the amount of material generated by the interaction between component (A) and component (B) will be excessive, reducing wettability and adhesion to the rubber surface, thus reducing anti-adhesion performance. In this case, the viscosity of the anti-adhesion agent composition may increase significantly, and handling may become difficult. Furthermore, the non-volatile content of the anti-adhesion agent composition for unvulcanized rubber in this invention is the residue after the anti-adhesion agent composition has been dried in an environmental testing machine at 40°C and its mass has become constant.

[0039] The mass percentage of component (A) in the anti-adhesion composition of the present invention is not particularly limited, but is preferably 5 to 30% by mass, more preferably 10 to 25% by mass. When the mass percentage is 5% by mass or more, interaction between component (A) and component (B) is more likely to occur, and uniform adhesion tends to improve. When the mass percentage is 30% by mass or less, the interaction between component (A) and component (B) is optimized, the anti-adhesion properties and the flexibility of the dry solids are improved, and the increase in viscosity of the anti-adhesion composition tends to be suppressed.

[0040] The mass percentage of component (A) in the nonvolatile content of the anti-adhesion composition of the present invention is not particularly limited, but is preferably 20 to 60% by mass, more preferably 25 to 55% by mass. When the mass percentage is 20% by mass or more, wettability tends to improve. When the mass percentage is 60% by mass or less, lubricity tends to be optimized.

[0041] The mass percentage of component (B) in the anti-adhesion composition of the present invention is not particularly limited, but is preferably 5 to 25% by mass, more preferably 5 to 20% by mass. When the mass percentage is 5% by mass or more, the anti-adhesion properties and lubricity tend to improve. When the mass percentage is 25% by mass or less, the interaction between component (A) and component (B) is optimized, the uniform adhesion and flexibility of the dry solids improve, and the increase in viscosity of the anti-adhesion composition tends to be suppressed.

[0042] The mass percentage of component (B) in the nonvolatile content of the anti-adhesion composition of the present invention is not particularly limited, but is preferably 20 to 40% by mass, more preferably 25 to 35% by mass. When the mass percentage is 20% by mass or more, the lubricity tends to improve. When the mass percentage is 40% by mass or less, the wettability tends to improve.

[0043] The total mass percentage of components (A) and (B) in the nonvolatile content of the anti-adhesion composition of the present invention is not particularly limited, but is preferably 45% by mass or more, more preferably 45 to 90% by mass, and even more preferably 50 to 85% by mass. When the mass percentage is 45% by mass or more, the amount of methanol-insoluble component (II) generated increases, and uniform adhesion and anti-adhesion properties tend to improve.

[0044] The anti-adhesion composition of the present invention is not particularly limited, but is preferable if it further satisfies the following condition 2, in that it forms a film with superior flexibility. Condition 2: The mass ratio of component (A) and the mass ratio of component (B) in the nonvolatile content of the anti-adhesion composition satisfy the relationship shown in formula (2) below. (Mass ratio of component (A)) > (Mass ratio of component (B)) Equation (2)

[0045] The mass ratio (A / B) of component (A) to component (B) contained in the anti-adhesion composition of the present invention is not particularly limited, but is preferably 1.05 to 2, more preferably 1.1 to 1.9, and even more preferably 1.15 to 1.8.

[0046] The mass percentage of component (C) in the anti-adhesion composition of the present invention is not particularly limited, but is preferably 30 to 90% by mass, more preferably 50 to 85% by mass, and even more preferably 60 to 80% by mass. When the mass percentage is 30% by mass or more, it tends to adhere more uniformly to unvulcanized rubber. When the mass percentage is 90% by mass or less, the amount of methanol-insoluble component (II) generated tends to be more optimized.

[0047] When the anti-adhesion composition of the present invention contains component (D), the mass percentage of component (D) in the anti-adhesion composition is not particularly limited, but is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass. When the mass percentage is 0.5% by mass or more, wettability tends to improve. When the mass percentage is 10% by mass or less, the interaction between component (A) and component (B) tends to be optimized.

[0048] When the anti-adhesion composition of the present invention contains component (D), the mass percentage of component (D) in the non-volatile content of the anti-adhesion composition of the present invention is not particularly limited, but is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass. When the mass percentage is 1% by mass or more, the wettability to unvulcanized rubber tends to improve. When the mass percentage is 40% by mass or less, the lubricity tends to be optimized.

[0049] When the anti-adhesion composition of the present invention contains component (E), the mass percentage of component (E) in the anti-adhesion composition of the present invention is not particularly limited, but is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass, and even more preferably 1 to 5% by mass. When the mass percentage is 0.5% by mass or more, the anti-adhesion properties and lubricity tend to improve. When the mass percentage is 10% by mass or less, the stability of the anti-adhesion composition tends to improve.

[0050] The mass percentage of component (E) in the nonvolatile content of the anti-adhesion composition of the present invention is not particularly limited, but is preferably 1 to 30% by mass, more preferably 3 to 25% by mass, and more preferably 5 to 20% by mass. When the mass percentage is 1% by mass or more, the anti-adhesion properties and lubricity tend to improve. When the mass percentage is 30% by mass or less, the flexibility of the dry solids tends to improve.

[0051] The pH of the anti-adhesion composition of the present invention at 20°C is not particularly limited, but in terms of achieving the effects of the present invention, it is preferably 6 to 13, more preferably 7 to 12.5, even more preferably 7.5 to 12, and most preferably 8 to 11.5. The viscosity of the anti-adhesion composition of the present invention at 20°C is not particularly limited, but in terms of the handling properties of the anti-adhesion composition, it is preferably 10 to 10,000 mPa·s, more preferably 20 to 5,000 mPa·s, even more preferably 20 to 3,000 mPa·s, and particularly preferably 30 to 2,000 mPa·s. The viscosity of the anti-adhesion composition of the present invention at 20°C refers to the viscosity measured at 20°C using a B-type viscometer (12 rpm).

[0052] One method for producing the anti-adhesion composition of the present invention is to mix the above components (A) to (C) with components (D) to (E) and other components as needed. Methods for mixing the ingredients include, for example, adding and mixing all ingredients simultaneously, adding and mixing each ingredient sequentially, or adding and mixing some ingredients beforehand and then adding and mixing the remaining ingredients or a mixture thereof. There are no particular limitations on the mixing process; it can be carried out using a device with a very simple mechanism, such as a container and a stirring blade. Examples of mixing devices include homomixers, homogenizers, colloid mills, and line mixers.

[0053] Furthermore, during the production of the anti-adhesion composition, the components (A) to (C) may be mixed while heating, or at least one of the components (A) to (C) may be heated before mixing with the other components. Alternatively, a mixture containing components (A) to (C) may be obtained and then heated. During the production of the anti-adhesion composition, heating when obtaining the mixture of components (A) to (C), or after obtaining the mixture, can promote the interaction between component (A) and component (B), making it easier to obtain an anti-adhesion composition that satisfies the above condition 1. When manufacturing the anti-adhesion agent composition, it is preferable to heat the mixture of components (A) to (C) during the mixing process, as this allows for efficient acquisition of the anti-adhesion agent composition.

[0054] The heating temperature is not particularly limited, but is preferably 45 to 95°C, more preferably 50 to 90°C, and even more preferably 60 to 80°C. There are no particular limitations on the heating time, but it is preferably 15 minutes or more and less than 120 minutes, more preferably 30 to 110 minutes, and even more preferably 60 to 100 minutes. By keeping the heating temperature and heating time within the above range, excessive interaction between component (A) and component (B) can be suppressed, making it easier to obtain an anti-adhesion composition that satisfies condition 1 above.

[0055] In addition, if the mixture of components (A) to (C) is heated during the production of the anti-adhesion composition, or after the mixture has been obtained, it may be cooled afterward. Cooling allows the components (A) and (B) to interact and stabilize, which in turn interacts with component (C), making it easier to obtain an anti-adhesion composition that satisfies the above condition 1. The cooling temperature is not particularly limited, but is preferably 40°C or lower, more preferably 35°C or lower, and even more preferably 30°C or lower. To promote the interaction between component (A) and component (B), the above heating and cooling process may be repeated.

[0056] [Method for manufacturing unvulcanized rubber with anti-adhesion treatment] The present invention relates to a method for producing anti-adhesion treated unvulcanized rubber, which includes a step of applying the above-mentioned anti-adhesion composition for unvulcanized rubber to the surface of the unvulcanized rubber. Here, the unvulcanized rubber may be molded. There are no particular limitations on the processing steps, but examples include the following methods 1) to 3). 1) A method of spraying an anti-adhesion agent composition, a dispersion thereof in water, or a diluted solution thereof. 2) A method of spraying an anti-adhesion agent composition into rubber in the form of fine particles. 3) A method of immersion in an anti-adhesion composition, a dispersion thereof in water, or a diluted solution thereof. The method described in 3) above is preferred because it allows the anti-adhesion agent composition to be applied uniformly.

[0057] The unvulcanized rubber used in the manufacturing method of the present invention is usually heated to 100-180°C and can be cooled by immersion in a dispersion. The temperature of the dispersion is not particularly limited, but is preferably 0-60°C. Subsequently, a drying step may be performed on the unvulcanized rubber after the dispersion has been applied. The drying method is not particularly limited, but a method of forcibly drying by blowing hot air using a hot air fan or blow heater is preferable as it is less expensive.

[0058] When diluting an anti-adhesion agent composition with water, the effective concentration of the diluent is not particularly limited, but is preferably 0.01 to 15% by mass, more preferably 0.05 to 12.5% ​​by mass, and even more preferably 0.1 to 10% by mass, as it exhibits good wettability and anti-adhesion properties. A concentration of 0.01% by mass or higher tends to improve anti-adhesion properties. A concentration of 15% by mass or lower tends to improve drying properties. The above effective concentration refers to the concentration of components other than water in the diluent. In this way, the anti-adhesion treated unvulcanized rubber can be stored in stacks without sticking together between processes. [Examples]

[0059] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to these examples. In the following examples and comparative examples, unless otherwise specified, "parts" refers to "parts by mass." Furthermore, the evaluation of each physical property in the following examples and comparative examples was carried out as follows.

[0060] [Measurement of the mass ratio of alkali metals and non-alkali metals contained in methanol-insoluble component (II)] (Method for obtaining methanol-insoluble component (II)) The anti-adhesion agent composition was dried in an environmental testing chamber at 40°C to remove moisture. The residue obtained when the mass became constant was considered the non-volatile content of the anti-adhesion agent composition. Next, the non-volatile components of the obtained anti-adhesion agent composition were immersed in acetone to disperse and dissolve. After standing at 25°C for 2 hours, the insoluble components were separated by filtration and dried in an environmental testing chamber at 40°C. The residue obtained when a constant weight was reached was designated as acetone-insoluble component (I). The obtained acetone-insoluble component (I) was immersed in methanol to disperse and dissolve. After standing at 25°C for 2 hours, the insoluble portion was separated by filtration and dried in an environmental testing chamber at 40°C. The residue obtained when a constant weight was reached was designated as methanol-insoluble component (II). (Measurement of the mass ratio of alkali metals and non-alkali metals contained in insoluble component (II)) The content of alkali metals and non-alkali metals in 1 g of the obtained methanol-insoluble (II) was measured by X-ray fluorescence analysis. From the measured mass percentages of alkali metals and non-alkali metals, the mass percentage of alkali metals relative to the total mass percentages of alkali metals and non-alkali metals was calculated.

[0061] [Evaluation of uniform adhesion] A NR / BR rubber test piece (natural rubber / butadiene rubber; 0.5 cm thick × 5 cm long × 3 cm wide) heated to 100°C was immersed in an aqueous dilution of the anti-adhesion agent composition (non-volatile content of the anti-adhesion agent composition; 3% by mass) and immediately removed. After air-drying at room temperature, the surface of the test piece was visually inspected to determine if the anti-adhesion agent composition was uniformly adhered. ◎: The anti-adhesion agent composition adheres uniformly to the entire surface of the unvulcanized rubber, resulting in excellent uniform adhesion. ○: The anti-adhesion agent composition adheres to the entire surface of the unvulcanized rubber, but traces of liquid leakage can be seen in a few places, indicating that the uniformity of adhesion is somewhat good. △: The anti-adhesion agent composition adheres to the entire surface of the unvulcanized rubber, but traces of liquid runoff are visible on more than 50% of the surface, indicating somewhat poor uniformity of adhesion. ×: There are areas on the unvulcanized rubber surface where the anti-adhesion agent composition is not adhered, resulting in poor uniform adhesion.

[0062] [Evaluation of adhesion resistance] A diluted solution of the anti-adhesion agent composition (non-volatile content of the anti-adhesion agent composition; 3% by mass), dispersed in water heated to 45°C, was used to immerse an NR / BR test piece (natural rubber / butadiene rubber; 0.5 cm thick × 5 cm long × 3 cm wide) heated to 100°C. The piece was immediately removed. Two immersed rubber test pieces were prepared, air-dried, and then stacked. A pressure of 1000 kg / m² was applied. 2 A considerable load was applied, and the specimens were left in a 40°C constant temperature chamber for 24 hours. After removing the specimens from the chamber, they were air-cooled to room temperature, and the peel resistance (N / cm) was measured using a tensile testing machine at a speed of 100 mm / min. A lower peel resistance indicates easier peeling and higher adhesion resistance. The evaluation criteria were as follows, with a peel resistance of 2 N / cm or less being considered acceptable. ◎: The peel resistance is 1 N / cm or less, and it has excellent adhesion resistance. (Unvulcanized rubber can be easily peeled apart.) ○: The peel resistance is greater than 1 N / cm and less than or equal to 2 N / cm, indicating slightly superior adhesion resistance. (Unvulcanized rubber can be peeled apart without any load.) △: The peel resistance is greater than 2 N / cm but less than or equal to 3 N / cm, indicating somewhat poor adhesion resistance. (The load is high when separating unvulcanized rubber from each other.) ×: The peel resistance is greater than 3 N / cm, indicating poor adhesion. (The rubbers adhere tightly to each other, making separation difficult.)

[0063] [Evaluation of the flexibility of dry solids] The anti-adhesion agent composition was concentrated to dryness in an environmental testing chamber at 40°C to prepare 10 mm square dry solids. The obtained dry solids were then temperature-controlled in an environmental testing chamber at 20°C, and their hardness was measured using a durometer. A lower value indicates greater crumbling and higher flexibility of the dry solid. The evaluation criteria were as follows, with a value of less than 70 considered acceptable. ◎: A value of less than 60 indicates excellent flexibility. (The dry solid content crumbles easily.) ○: A value between 60 and 70 indicates slightly superior flexibility. (The dry solids will crumble.) △: A value between 70 and 80 indicates slightly poor flexibility. (The dry solid content is somewhat resistant to crumbling.) ×: Value is 80 or higher or measurement is not possible, indicating poor flexibility. (The dry solids are not easily crumbled.)

[0064] (Example 1) 2.5 parts potassium 2-ethylhexanoate, 5 parts potassium oleate, 0.5 parts calcium caprate, 6 parts zinc stearate, 70 parts water, 4 parts POE(3) alkyl(C12-14) ether, and 4 parts POE(9) alkyl(C12-14) ether were uniformly mixed, then heated to 60°C and stirred for 30 minutes. Next, the mixture was cooled to below 45°C, and 8 parts styrene-vinyl acetate copolymer particles were added and uniformly mixed to obtain an anti-adhesion agent composition. Then, water was added to a concentration of non-volatile matter of 3% by mass, and the mixture was uniformly dispersed in the water to obtain a diluted solution of the anti-adhesion agent composition for unvulcanized rubber. The uniform adhesion and anti-adhesion properties of the obtained diluted solution were evaluated as described above. The flexibility of the dry solids of the anti-adhesion agent composition was also evaluated as described above. The evaluation results are shown in Table 1, and the composition exhibited excellent uniform adhesion, anti-adhesion properties, and flexibility of the dry solids.

[0065] (Examples 2-10, Comparative Examples 1-5) In Examples 2-10 and Comparative Examples 1-5, anti-adhesion agents for unvulcanized rubber and their dilutions were obtained and evaluated in the same manner as in Example 1, except that the composition and manufacturing conditions were changed as shown in Tables 1-2. The results are shown in Tables 1-2, respectively. Further details regarding the raw materials listed in Tables 1 and 2 are as follows. In the raw materials listed in Tables 1 and 2, POE stands for polyoxyethylene, and the number in parentheses following POE indicates the number of moles of oxyethylene added. Potassium coconut fatty acid: Contains 5% by mass of saturated potassium fatty acids with 10 or fewer carbon atoms, 64.2% by mass of saturated potassium fatty acids with 12 to 14 carbon atoms, 10.4% by mass of saturated potassium fatty acids with 16 or more carbon atoms, and 20.4% by mass of unsaturated potassium fatty acids with 16 or more carbon atoms. Styrene-vinyl acetate copolymer particles: Volume average particle size 5 μm Oxidized polyethylene wax particles: Volume average particle size 0.18 μm Polyethylene particles: Volume average particle size 10 μm

[0066] [Table 1]

[0067] [Table 2]

[0068] As can be seen from Tables 1-2, the anti-adhesion compositions of Examples 1-10 contain a fatty acid alkali metal salt as component (A), a salt of a fatty acid and a metal other than an alkali metal as component (B), and water as component (C), satisfying the above condition 1, and thus solving the problem of the present invention. On the other hand, the problem of the present invention is not solved when component (A) is not included (Comparative Example 1), when component (B) is not included (Comparative Example 2), when component (C) is not included (Comparative Example 3), or when condition 1 is not met (Comparative Examples 4 and 5).

Claims

1. An anti-adhesion composition for unvulcanized rubber, comprising the following components (A) to (C) and satisfying condition 1 below. Ingredient (A): Alkali metal salt of fatty acid Component (B): Salt of fatty acid with a metal other than an alkali metal. Component (C): water Condition 1: The non-volatile components of the anti-adhesion agent composition for unvulcanized rubber are immersed in acetone to obtain an acetone-insoluble component (I). Then, the insoluble component (I) is immersed in methanol to obtain a methanol-insoluble component (II). The mass ratio of alkali metals and the mass ratio of metals other than alkali metals contained in the insoluble component (II) satisfy the following relationship (1). 0.05 ≤ (mass percentage of alkali metals) ÷ (sum of mass percentages of alkali metals and non-alkali metals) ≤ 0.2 Equation (1)

2. The anti-adhesion agent composition for unvulcanized rubber according to claim 1, wherein the total mass ratio of component (A) and component (B) to the non-volatile content of the anti-adhesion agent composition for unvulcanized rubber is 45% by mass or more.

3. An anti-adhesion composition for unvulcanized rubber according to claim 1 or 2, satisfying the following condition 2. Condition 2: The mass ratio of component (A) and the mass ratio of component (B) in the nonvolatile content of the anti-adhesion agent composition for unvulcanized rubber satisfy the relationship shown in formula (2) below. (Mass ratio of component (A)) > (Mass ratio of component (B)) Equation (2)

4. The anti-adhesion composition for unvulcanized rubber according to claim 1 or 2, wherein component (A) comprises a fatty acid alkali metal salt (a1) having 10 or fewer carbon atoms and a fatty acid alkali metal salt (a3) ​​having 16 or more carbon atoms, and the mass ratio (a1 / a3) of the fatty acid alkali metal salt (a1) to the fatty acid alkali metal (a3) ​​is 15 / 100 to 200 / 100.

5. The anti-adhesion composition for unvulcanized rubber according to claim 1 or 2, further comprising the following component (D). Ingredient (D): Nonionic surfactant

6. The anti-adhesion agent composition for unvulcanized rubber according to claim 5, wherein component (D) has oxyalkylene structural units, and the number of oxyalkylene structural units is 6 or more.

7. The anti-adhesion composition for unvulcanized rubber according to claim 1 or 2, further comprising the following component (E). Ingredients (E): Organic polymer particles

8. A method for producing anti-adhesion treated unvulcanized rubber, comprising the step of applying the anti-adhesion composition for unvulcanized rubber described in claim 1 or 2 to the surface of unvulcanized rubber.

Images