Anti-adhesion composition for unvulcanized rubber and its use

Abstract

To provide: an adhesion inhibitor composition for unvulcanized rubber, having excellent dispersibility and adhesion inhibition property at the same time; and a method for producing unvulcanized rubber which has been subjected to an adhesion inhibition treatment performed by using the adhesion inhibitor composition for unvulcanized rubber.SOLUTION: Provided is an adhesion inhibitor composition for unvulcanized rubber, comprising: an inorganic component containing a silicate as an essential ingredient; and a surfactant. The silicate contains at least one selected from iron oxide and iron sulfide, and a total of weight ratios of the iron oxide and the iron sulfide relative to a total of the silicate, the iron oxide, and the iron sulfide is 10 wt% or less. The surfactant contains an anionic surfactant (A) and a nonionic surfactant (B), and a weight ratio (A / B) represented by [weight of (A)] / [weight of (B)] is 1 to 20.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to an anti-adhesion composition for unvulcanized rubber and its use. [Background technology]

[0002] In the production and processing of rubber products, unvulcanized rubber is sometimes stored in stacks until it is moved to the next molding or vulcanization process. In this case, an anti-adhesion agent (anti-sticking agent) is used to prevent the rubber from sticking together. Anti-adhesion agents, primarily composed of inorganic powders and surfactants, are widely used. Generally, these are applied to rubber surfaces in the form of aqueous dispersions and then dried. Application methods include spraying the aqueous dispersion or immersing the rubber surface in the aqueous dispersion. However, the sediment generated when using these aqueous dispersions of inorganic powders poses a challenge, as it can lead to a deterioration of the working environment and a decrease in productivity. Excessive sedimentation necessitates cleaning of the equipment and hinders uniform application due to spray clogging and uneven dispersion concentration. For these reasons, there is a need for the development of anti-adhesion agents that produce less sediment and offer superior anti-adhesion performance.

[0003] While various anti-adhesion agents have been developed to date, none have yet solved the above problems while also providing sufficient anti-adhesion protection. Patent Document 1 discloses an anti-adhesion agent that requires bentonite containing a specific amount of montmorillonite, a water-swellable inorganic powder, and a surfactant containing an anionic surfactant and a nonionic surfactant in specific ratios. By increasing the ratio of the nonionic surfactant to that of the anionic surfactant, the adhesion of the anti-adhesion agent to the rubber surface is improved, thereby enhancing its anti-adhesion properties. However, under conditions where the dispersion is at a low concentration, the dispersion effect of the anionic surfactant on the inorganic powder is significantly reduced, leading to a problem of sedimentation. Patent Document 2 discloses a method of preventing adhesion by applying a composition in which fatty acid soaps with limited carbon number and metal ions, metal soaps, and specific surfactants are dispersed in water to a rubber surface. Since inorganic powders are not used, the problem of sedimentation does not occur, but in order to exert a sufficient anti-adhesion effect, it is necessary to use it at a high concentration, which in turn has the problem of degrading the physical properties of vulcanized rubber, thus limiting its use and lacking versatility. As described above, various anti-adhesion agents have been developed, but none have been found to suppress the settling of inorganic powders and provide sufficient anti-adhesion properties. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2013-213202 [Patent Document 2] Japanese Patent Application Publication No. 49-18780 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide an anti-adhesion agent composition for unvulcanized rubber that exhibits excellent dispersibility and anti-adhesion properties simultaneously, and a method for producing anti-adhesion treated unvulcanized rubber using the anti-adhesion agent composition for unvulcanized rubber. [Means for solving the problem]

[0006] As a result of diligent research to solve the above problems, the inventors have found that the above problems can be solved if the weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide and iron sulfide is within a specific range, and the anti-adhesion composition contains anionic surfactant (A) and nonionic surfactant (B) in a specific ratio.

[0007] In other words, the anti-adhesion composition for unvulcanized rubber of the present invention is an anti-adhesion composition for unvulcanized rubber containing an inorganic component and a surfactant, wherein the inorganic component essentially contains a silicate and at least one selected from iron oxide and iron sulfide, the total weight ratio of iron oxide and iron sulfide to the total of the silicate, iron oxide and iron sulfide is 10% by weight or less, and the surfactant includes an anionic surfactant (A) and a nonionic surfactant (B), and the weight ratio (A / B), expressed as the weight of (A) / the weight of (B), is 1 to 20.

[0008] It is preferable to further contain carbonates and / or metal soaps. It is preferable that the anionic surfactant (A) includes a fatty acid soap.

[0009] The present invention provides 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 molded unvulcanized rubber. [Effects of the Invention]

[0010] The anti-adhesion composition for unvulcanized rubber of the present invention exhibits excellent dispersibility and anti-adhesion properties. Furthermore, in the method for producing unvulcanized rubber of the present invention, the use of the anti-adhesion composition for unvulcanized rubber of the present invention improves workability due to good dispersibility and anti-adhesion properties, and reduces defects in rubber products. [Modes for carrying out the invention]

[0011] [Anti-adhesion agent composition for unvulcanized rubber] The present invention provides an anti-adhesion composition for unvulcanized rubber that contains an inorganic component, which is essential for a silicate, and a surfactant. The following provides a detailed explanation of each component.

[0012] [Inorganic components] Inorganic components are the materials that form a film on the surface of unvulcanized rubber, providing anti-adhesion properties. The anti-adhesion agent composition for unvulcanized rubber of the present invention contains a silicate as an essential inorganic component. Silicates generally have a structure formed by the connection of silicate tetrahedrons, where one silicon atom enters the gap in the middle of the triangular pyramid formed by four oxygen atoms. Silicates are further classified into nesosilicates, sorosilicates, cyclosilicates, inosilicates, phyllosilicates, tectosilicates, etc. according to the connection method of silicate tetrahedrons. In the antisticking agent for unvulcanized rubber of the present invention, one or more of these silicates may be used in combination.

[0013] Nesosilicates are classified as silicates with an independent connection method and have a basic composition of a structure represented by the chemical formula (SiO4). , 6- , 6- , 4- , There is no particular limitation on nesosilicates. For example, garnets such as forsterite, fayalite, and mangankrantzite; humite; pyrope, almandine, spessartine, grossular, andradite, uvarovite, etc. of garnet; gadolinite such as datolite and sillimanite can be mentioned, and one or more of these may be used in combination. Sorosilicates are classified as silicates with a composite connection method and have a basic composition of at least one selected from the structures represented by the chemical formulas (Si2O7) and (Si5O). 6- and (Si5O 16 ) 12- There is no particular limitation on sorosilicates. For example, epidote such as zoisite and clinozoisite; melilite such as okermanite and gailite; pampeolite such as vesuvianite can be mentioned, and one or more of these may be used in combination.

[0014] Cyclosilicates are classified as silicates with a cyclic connection method and have a basic composition of a structure represented by the chemical formulas (Si3O9), (Si4O), (Si6O). 6- , (Si4O 12 ) 8- , (Si6O 18 ) 12- There is no particular limitation on cyclosilicates. For example, benitoite; axinite; beryl; tourmaline such as ferroelectric tourmaline, magnesian tourmaline, and lithia tourmaline; osumilite can be mentioned, and one or more of these may be used in combination. Inosilicates are classified as silicates with a single-chain connection method and have a basic composition of a structure represented by the chemical formula (Si2O6). 4-, (Si3O9) 6- , (Si4O 11 ) 6- , (Si5O 15 ) 10- , (Si7O 21 ) 14- It has a basic composition of a structure represented by the chemical formula. As inosilicates, there is no particular limitation, for example, pyroxenes such as diopside, clinopyroxene, enstatite, acmite, spodumene, etc.; amphiboles such as orthoamphibole, tremolite, glaucophane, rodonite, etc. These may be used alone or in combination of two or more kinds.

[0015] Phyllosilicates are classified as silicates with a layered linkage type and have a basic composition of a structure represented by the chemical formula of SiO2. As phyllosilicates, there is no particular limitation, for example, smectites such as montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite, etc.; vermiculites such as di-vermiculite, tri-vermiculite, etc.; kaolinites such as halloysite, kaolin, endellite, dickite, nacrite, chrysotile, etc.; talc; mica such as tetrasilicic mica, etc.; pyrophyllite; margarite; clintonite; mica minerals such as muscovite, biotite, phlogopite, synthetic mica, fluorophlogopite, etc.; paragonite; fluorophlogopite; lepidolite; jamosite such as antigorite, etc.; chlorites such as donpeacite, sudite, cookeite, clinocroite, chamosite, chlorite, nantite, etc.; piolite-paragonite such as sepiolite, palygorskite, etc. These may be used alone or in combination of two or more kinds. Tectosilicates are classified as silicates with a network linkage type and have a basic composition of a structure represented by the chemical formula of SiO2. As tectosilicates, there is no particular limitation, for example, feldspars such as sanidine, albite, anorthosite, nepheline, etc.; zeolites such as leucite, scolecite, stilbite, etc.; cordierite, etc. These may be used alone or in combination of two or more kinds.

[0016] The silicate contained in the inorganic component used in this invention preferably contains phyllosilicate, which can form a coating with good water dispersibility and excellent adhesion properties. In particular, it is preferable that the phyllosilicate is at least one selected from smectite, kaolinite, talc, and mica, as this forms a coating with excellent adhesion properties. When smectite comes into contact with water, water molecules successively hydrate the exchangeable cations between its layers, causing it to swell and thus effectively disperse in water. Therefore, if the phyllosilicate is smectite, it is even more preferable because it exhibits excellent dispersibility and improved film-forming properties when mixed with water. Among smectites, montmorillonite is preferred because of its particularly remarkable water-swelling properties.

[0017] Montmorillonite is a dioctahedral, hydrated, layered silicate mineral containing sodium, calcium, potassium, magnesium, and hydrogen ions as exchange cations. These cations are readily exchangeable and also readily absorb water. When the exchange cation is a sodium ion, it readily absorbs water molecules through hydration, increasing the interlayer spacing and causing significant swelling. Generally, layered clay minerals containing montmorillonite as the main component are called bentonite. Bentonite is an example of an inorganic component that can be easily adsorbed onto the surface of unvulcanized rubber and form a film. Since the bentonite film has excellent anti-adhesion and lubricity properties, it is even more preferable that the silicate in the anti-adhesion agent composition for unvulcanized rubber of the present invention contains bentonite as an essential component. Furthermore, it is particularly preferable that the bentonite contains sodium bentonite in high purity, as this significantly enhances its water-swelling effect.

[0018] The amount of silicate contained in the anti-adhesion agent composition for unvulcanized rubber of the present invention is not particularly limited, but when the total amount of inorganic components and surfactants is 100 parts by weight, it is preferably 30 to 90 parts by weight, more preferably 32.5 to 87.5 parts by weight, even more preferably 35 to 85 parts by weight, and particularly preferably 37.5 to 82.5 parts by weight. When the silicate content is 30 parts by weight or more, the anti-adhesion properties tend to improve, and when it is 90 parts by weight or less, the dispersibility tends to improve.

[0019] In addition to the silicate mentioned above, the inorganic components must include at least one selected from iron oxide and iron sulfide. Furthermore, the total weight percentage of iron oxide and iron sulfide relative to the total of silicate, iron oxide, and iron sulfide is 10% by weight or less. Although silicate may be present with trace amounts of iron compounds, iron compounds have a higher specific gravity than silicate and carbonate. Therefore, if the weight percentage of iron compounds in silicate exceeds 10% by weight, precipitates will form, leading to decreased productivity and reduced adhesion resistance. In this invention, the iron compound refers to at least one selected from iron oxide and iron sulfide, and may contain both. The total weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide, and iron sulfide is preferably 9% by weight or less, more preferably 8% by weight or less, even more preferably 7% by weight or less, and particularly preferably 6% by weight or less. On the other hand, there is no particular limit to the total weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide, and iron sulfide, but it is preferred in the following order: (1) greater than 0% by weight, (2) 0.05% by weight, (3) 0.1% by weight, (4) 0.3% by weight, (5) 0.6% by weight, (6) 0.7% by weight, (7) 0.8% by weight, (8) 0.9% by weight, and (9) 1% by weight (the higher the number in parentheses, the more preferable it is).

[0020] As a method for adjusting the weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide, and iron sulfide, commercially available silicates with a weight ratio of 10% by weight or less of iron compounds present together can be obtained, or the silicate composition containing iron compounds may be subjected to treatments such as centrifugation or centrifugation, or iron compounds may be mixed in.

[0021] [Analysis method for the weight percentage of iron compounds] The weight percentage of iron compounds present with silicates was measured by powder X-ray diffraction. When the measured value was below the detection limit, it was recorded as 0% by weight.

[0022] The inorganic components may include inorganic substances other than silicates, iron oxides, and iron sulfides. While there are no particular limitations on the inorganic substances other than silicates, iron oxides, and iron sulfides, examples include carbonates such as calcium carbonate, sodium carbonate, and magnesium carbonate; sulfates such as calcium sulfate and barium sulfate; metal oxides such as amorphous silica, alumina, magnesium oxide, antimony trioxide, titanium oxide, and white carbon; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; red iron oxide; carbon black; graphite, etc. Among these inorganic substances other than silicates, iron oxides, and iron sulfides, carbonates are preferred in terms of their ability to prevent adhesion to unvulcanized rubber. Furthermore, it is more preferable that at least one selected from calcium carbonate, sodium carbonate, and magnesium carbonate is used.

[0023] While there are no particular limitations on the average particle size of the inorganic components, considering adhesion to unvulcanized rubber, it is preferably 0.1 to 200 μm, more preferably 0.1 to 100 μm, even more preferably 0.1 to 50 μm, particularly preferably 0.1 to 40 μm, and most preferably 0.1 to 30 μm.

[0024] [Surfactants] Surfactants are essential components of the present invention, assisting in the dispersion of the anti-adhesion agent composition and assisting in "wetting" of unvulcanized rubber. The inclusion of surfactants in the anti-adhesion agent composition for unvulcanized rubber of the present invention improves the dispersibility of inorganic components, suppressing sedimentation, and improves wettability to unvulcanized rubber, allowing for a more uniform film to be formed on the surface of the unvulcanized rubber.

[0025] The surfactant used in this invention essentially includes an anionic surfactant and a nonionic surfactant. The anionic surfactant improves the dispersibility of the anti-adhesion composition, and the nonionic surfactant improves the adhesion of the anti-adhesion composition to rubber. Therefore, both anionic and nonionic surfactants are essential.

[0026] A key aspect of the present invention is the correlation between the weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide, and iron sulfide, and the weight ratio (A / B) of anionic surfactant (A) to nonionic surfactant (B). In other words, the researchers identified iron compounds as substances that inhibit the stability of anti-adhesion compositions, and found that when the iron compound is present at a specific level, the iron compound can be appropriately dispersed when anionic surfactant (A) and nonionic surfactant (B) are blended in a specific ratio.

[0027] In other words, to satisfy both dispersibility and adhesion properties, the weight ratio (A / B) of the anionic surfactant (A) to the nonionic surfactant (B) must be in the range of 1 to 20. If A / B is less than 1, dispersibility decreases and sedimentation increases. On the other hand, if A / B exceeds 20, adhesion decreases. A / B is preferably 1.2 to 18, more preferably 1.4 to 16, and even more preferably 1.6 to 14.

[0028] There are no particular limitations on anionic surfactants and nonionic surfactants; they may contain one or more types. Examples of anionic surfactants include fatty acid soaps such as potassium caprate, sodium caprate, sodium laurate, potassium laurate, sodium palmitate, potassium plutinate, potassium stearate, sodium palm kernel oil fatty acid, potassium palm kernel oil fatty acid, potassium palm stearate, sodium palm stearate, sodium coconut oil fatty acid, potassium coconut oil fatty acid, sodium beef tallow fatty acid, potassium beef tallow fatty acid; alkyl sulfate esters such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium stearyl sulfate, sodium cetyl sulfate; polyoxyalkylene alkyl ether acetates such as sodium polyoxyethylene tridecyl ether acetate; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; and polyoxyalkylene alkyl ether sulfates. Examples include: long-chain sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium 2-ethylhexyl sulfosuccinate; N-acyl sarcosinate salts such as sodium oleoyl sarcosinate and sodium lauroyl sarcosinate; higher fatty acid amide sulfonates such as sodium stearoyl methyl taurate, sodium lauroyl methyl taurate, sodium myristoyl methyl taurate, and sodium palmitoyl methyl taurate; alkyl phosphates such as sodium monostearyl phosphate; polyoxyalkylene alkyl ether phosphate salts such as sodium polyoxyethylene oleyl ether phosphate and sodium polyoxyethylene stearyl ether phosphate; and long-chain N-acyl glutamate salts such as sodium N-lauroyl glutamate monosodium and disodium N-stearoyl-L-glutamate. One or more of these may be used in combination.

[0029] Examples of nonionic surfactants include: decyl ether with 3 moles of polyoxyethylene, decyl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene, decyl ether with 5 moles of polyoxyethylene, decyl ether with 7 moles of polyoxyethylene, isodecyl ether with 3 moles of polyoxyethylene, isodecyl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene, isodecyl ether with 5 moles of polyoxyethylene, isodecyl ether with 7 moles of polyoxyethylene, lauryl ether with 3 moles of polyoxyethylene, lauryl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene, lauryl ether with 5 moles of polyoxyethylene, lauryl ether with 7 moles of polyoxyethylene, tridecyl ether with 3 moles of polyoxyethylene, tridecyl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene, tridecyl ether with 5 moles of polyoxyethylene, tridecyl ether with 7 moles of polyoxyethylene, and polyoxyethylene Polyoxyalkylene alkyl ethers such as isotridecyl ether with 3 moles of polyethylene added, isotridecyl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene added, isotridecyl ether with 5 moles of polyoxyethylene added, isotridecyl ether with 7 moles of polyoxyethylene added, myristyl ether with 3 moles of polyoxyethylene added, myristyl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene added, myristyl ether with 5 moles of polyoxyethylene added, myristyl ether with 7 moles of polyoxyethylene added, cetyl ether with 3 moles of polyoxyethylene added, cetyl ether with 3 moles of polyoxyethylene and 1 mole of polyoxypropylene added, cetyl ether with 5 moles of polyoxyethylene added, and cetyl ether with 7 moles of polyoxyethylene added; polyoxyalkylene alkylphenyl ethers such as polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether; polyoxyalkylene fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monooleate;Examples include polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate; polyoxyalkylene alkylamines; fatty acid alkanolamides; polyoxyalkylene fatty acid amides; polyoxyalkylene hydrogenated castor oil; polyoxyalkylene sorbitol fatty acid esters; polyglycerin fatty acid esters; alkylglycerin ethers; polyoxyalkylene cholesteryl ethers; alkyl polyglucosides; sucrose fatty acid esters; and oxyethylene-oxypropylene block polymers, which may be used individually or in combination of two or more.

[0030] The amount of surfactant contained in the anti-adhesion agent composition for unvulcanized rubber of the present invention is not particularly limited, but when the total amount of inorganic components and surfactant is 100 parts by weight, it is preferably 1 to 40 parts by weight, more preferably 2 to 35 parts by weight, even more preferably 3 to 30 parts by weight, and particularly preferably 4 to 25 parts by weight. When the surfactant content is 1 part by weight or more, dispersibility tends to improve, and when it is 40 parts by weight or less, anti-adhesion properties tend to improve.

[0031] The anti-adhesion composition for unvulcanized rubber of the present invention may further contain the following components in addition to the components described above.

[0032] [Metallic soaps] Metallic soaps are components that adhere to the surface of unvulcanized rubber and can reduce friction between unvulcanized rubbers. Examples of metallic soaps include magnesium laurate, calcium laurate, zinc laurate, magnesium myristate, calcium myristate, zinc myristate, magnesium palmitate, calcium palmitate, zinc palmitate, magnesium stearate, calcium stearate, zinc stearate, aluminum trioctadecanoate, aluminum dioctadecanoate, aluminum monooctadecanoate, calcium octadecanoate, zinc octadecanoate, magnesium octadecanoate, and barium octadecanoate. One or more of these may be used in combination. As the metal soap, it is preferable to use at least one selected from magnesium stearate, calcium stearate, and zinc stearate, as this provides a high effect in reducing friction between unvulcanized rubbers.

[0033] Furthermore, the anti-adhesion composition for unvulcanized rubber of the present invention is preferable in that it contains carbonates and / or metal soaps, as this enhances the effects of the present invention. In the anti-adhesion composition for unvulcanized rubber of the present invention, if carbonate and / or metal soap are included, the total content of carbonate and metal soap is not particularly limited, but when the total amount of inorganic components and surfactants is 100 parts by weight, it is preferably 1 to 40 parts by weight, more preferably 2 to 35 parts by weight, even more preferably 3 to 30 parts by weight, and most preferably 4 to 25 parts by weight. When the total content of carbonate and metal soap is 1 part by weight or more, dispersibility tends to improve, and when it is 40 parts by weight or less, anti-adhesion properties tend to improve.

[0034] [Water-soluble polymer] Water-soluble polymers can impart viscosity to anti-adhesion compositions for unvulcanized rubber, improving their adhesion to the surface of the unvulcanized rubber. This effect is particularly enhanced when the composition for unvulcanized rubber is in the form of an aqueous dispersion, as described later. Examples of water-soluble polymers include starches such as oxidized starch, acetic acid starch, phosphate starch, carboxymethyl starch, carboxyethyl starch, hydroxyethyl starch, positive starch, cyanoethylated starch, and dialdehyde starch; mannan; alginic acids such as alginic acid, sodium alginate, propylene glycol alginate, triethanolamine alginate, and ammonium alginate; methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and hydroxyethylcellulose. Examples include cellulose ethers such as cellulose, hydroxyethyl ethylcellulose, and carboxymethylcellulose; natural gums such as tarakanto gum, gum arabic, guar gum, xanthan gum, British gum, glucomannan, gellan gum, tara gum, locust bean gum, and carrageenan; 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.

[0035] [Polyhydric alcohols] Polyhydric alcohols adhere to the surface of unvulcanized rubber, providing lubrication between the unvulcanized rubber layers and reducing friction between them. Examples of polyhydric alcohols include glycerin, 1,3-butanediol, propylene glycol, dipropylene 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.

[0036] [Antifoaming agent] Examples of defoaming agents include silicone-based defoamers such as polymethylsiloxane and polyether-modified silicone; oil-based defoamers such as castor oil, sesame oil, linseed oil, and animal and vegetable oils; fatty acid-based defoamers such as stearic acid, oleic acid, and palmitic acid; fatty acid ester-based defoamers such as isoamyl stearate, distearyl succinate, ethylene glycol distearate, and butyl stearate; and polyoxyalkylene monohydrate alcohols such as di-t-amylphenoxyethanol, 3-heptanol, and 2-ethylhexanol. Examples of antifoaming agents include ethanol-based antifoamers; ether-based antifoamers such as di-t-amylphenoxyethanol, 3-heptylcellosolve, nonylcellosolve, and 3-heptylcarbitol; phosphate ester antifoamers such as tributylphosphate and tris(butoxyethyl)phosphate; amine-based antifoamers such as diamylamine; amide-based antifoamers such as polyalkyleneamide and acylate polyamine; sulfate ester antifoamers such as sodium lauryl sulfate; polyoxyalkylene antifoamers; and mineral oils. One or more of these may be used in combination.

[0037] [Preservatives] 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-sulfonic acid, 1-amino Examples include aminosulfonic acids such as -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. One or more of these may be used in combination.

[0038] 〔water〕 The anti-adhesion composition for unvulcanized rubber of the present invention may contain water. The inclusion of water in the anti-adhesion composition for unvulcanized rubber is preferable from the viewpoint of handling properties. The water can be tap water, deionized water, distilled water, etc., and there are no particular limitations, but deionized water or distilled water is preferred. Also, from a quality control standpoint, soft water is preferred because its hardness can be adjusted. Furthermore, if the anti-adhesion agent composition for unvulcanized rubber of the present invention contains water, the anti-adhesion agent composition for unvulcanized rubber may be in the form of an aqueous dispersion in which components other than water are dispersed or dissolved in water.

[0039] When the anti-adhesion agent composition for unvulcanized rubber of the present invention is in the form of an aqueous dispersion, the weight percentage of water in the anti-adhesion agent composition for unvulcanized rubber is not particularly limited, but is preferably 90 to 99.99% by weight, more preferably 92.5 to 99.95% by weight, and even more preferably 95 to 99.5% by weight. When the weight percentage of water is 90% by weight or more, drying properties tend to improve, and when it is 99.9% by weight or less, anti-adhesion properties tend to improve.

[0040] [Method for manufacturing an anti-adhesion agent for unvulcanized rubber] In the present invention, there are no particular limitations on the manufacturing method of the anti-adhesion agent composition for unvulcanized rubber, as long as it includes a step of mixing an inorganic component, a surfactant, and other components as needed, in the order of mixing and the mixing equipment used. The anti-adhesion agent composition for unvulcanized rubber can be manufactured, for example, by sequentially adding and mixing each component in a mixer such as a ribbon-type mixer or a vertical screw-type mixer.

[0041] [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. In the processing step, a wet method is preferred, that is, a method using the anti-adhesion agent composition for unvulcanized rubber in the form of the aqueous dispersion described above.

[0042] When performing the processing step using the wet method, methods include spraying the anti-adhesion agent composition for unvulcanized rubber in the form of an aqueous dispersion, spraying it onto the rubber in a fine stream, or immersing it in an aqueous dispersion. The method of immersion in an aqueous dispersion is preferable because it allows for uniform adhesion of the anti-adhesion composition for unvulcanized rubber. 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 an aqueous dispersion. The temperature of the aqueous dispersion is not particularly limited, but is preferably 0-60°C. Next, a step may be taken to dry the unvulcanized rubber after applying the aqueous dispersion. There are no particular limitations on the drying method, but a method of forcibly drying by blowing hot air using a hot air fan or blow heater is preferable because it is inexpensive.

[0043] In the processing step, a dry method may be used, that is, a method using an anti-adhesion composition for unvulcanized rubber that does not contain water. In this way, the anti-adhesion treated unvulcanized rubber can be stored in stacks without sticking together between processes. [Examples]

[0044] The present invention will be specifically described below with reference to examples and comparative examples. It is not limited to the above. The evaluation of each physical property in the examples and comparative examples is as follows: I went. Examples 2-18 and 22 are for reference only.

[0045] [Adhesion resistance] An NR / BR 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 dispersion of an anti-adhesion agent composition for unvulcanized rubber (water weight ratio: 98.5% by weight) and immediately removed. Two immersed rubber test pieces were prepared, air-dried, and then stacked. A load of 1000 kg / m² was applied. 2 The specimens were subjected to a load and 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 less than 2 N / cm being considered acceptable. Peel resistance of 1 N / cm or less: Excellent adhesion (unvulcanized rubber can be easily separated from each other; the indicator is ◎) Peel resistance greater than 1 N / cm and less than 2 N / cm: Good adhesion resistance (unvulcanized rubber can be peeled apart without load; the indicator is ○) Peel resistance between 2N / cm and 3N / cm: Poor adhesion resistance (high load when separating unvulcanized rubber pieces, resulting in low adhesion resistance; index is △) Peel resistance exceeding 3 N / cm: Very poor adhesion (the rubbers adhere tightly to each other, making separation difficult. Adhesion resistance is very low; the indicator is ×)

[0046] [Dispersibility] An aqueous dispersion of an anti-adhesion agent composition for unvulcanized rubber (with a water weight of 98.5% by weight) was prepared and placed in a 100 ml graduated cylinder, where it was allowed to stand for 24 hours. After standing, the presence or absence of precipitate was checked. If precipitate was present, the graduated cylinder was inverted and mixed to evaluate whether the precipitate redispersed. The evaluation criteria for dispersibility were as follows. No precipitation: Dispersibility is very good (indicator is ◎) Precipitation occurs, but it redisperses easily: Dispersibility is good (5 or fewer inversions required, indicator is ○) Precipitation present, difficult to redisperse: Poor dispersibility (indicator is △, with more than 5 but less than 10 inversions). Precipitation present, redispersion very difficult: Dispersibility is very poor (more than 10 inversions required, indicator is ×)

[0047] (Example 1) A composition of anti-adhesion agent for unvulcanized rubber was obtained by uniformly mixing 1 g of bentonite, 10 g of calcium carbonate, 8 g of sodium dioctyl sulfosuccinate, and 2 g of POE(3) tridecyl ether. Next, 4.5 g of the above anti-adhesion agent composition was added to 295.5 g of tap water and uniformly dispersed in the water to obtain an aqueous dispersion of the anti-adhesion agent composition for unvulcanized rubber. The anti-adhesion properties and dispersibility of the obtained aqueous dispersion were evaluated. The evaluation results are shown in Table 1, and it exhibited excellent anti-adhesion properties and dispersibility.

[0048] (Examples 2-23) In Examples 2 to 23, anti-adhesion compositions for unvulcanized rubber and their aqueous dispersions were obtained and evaluated in the same manner as in Example 1, except that the composition was changed as shown in Tables 1 to 3. The evaluation results are shown in Tables 1 to 3.

[0049] (Comparative Example 1) A composition of anti-adhesion agent for unvulcanized rubber was obtained by uniformly mixing 80 g of bentonite 4, 10 g of calcium carbonate, 8 g of sodium dioctyl sulfosuccinate, and 2 g of POE(3) tridecyl ether. Next, 4.5 g of the above anti-adhesion agent composition was added to 295.5 g of tap water and uniformly dispersed in the water to obtain an aqueous dispersion of the anti-adhesion agent composition for unvulcanized rubber. The anti-adhesion properties and dispersibility of the obtained aqueous dispersion were evaluated. The evaluation results are shown in Table 4, and the dispersibility was poor.

[0050] (Comparative Examples 2-8) In Comparative Examples 2 to 8, anti-adhesion agents for unvulcanized rubber were obtained and evaluated in the same manner as in Comparative Example 1, except that the composition was changed as shown in Table 4. The results for each are shown in Table 4. In the above examples and comparative examples, POE(n) means polyoxyethylene (number of repeating units of oxyethylene: n), and POP(n) means polyoxypropylene (repeating unit of polyoxypropylene: n). Furthermore, the types of iron compounds contained in the silicate used and their weight ratios relative to the silicate are as follows. Bentonite 1: 1% by weight of iron oxide, 99% by weight of silicate Bentonite 2: 2% by weight of iron oxide and iron sulfide, 98% by weight of silicate Bentonite 3: 5% by weight of iron oxide and iron sulfide, 95% by weight of silicate Bentonite 4: 10% by weight of iron oxide and iron sulfide, 90% by weight of silicate Bentonite 5: 15% by weight of iron oxide and iron sulfide, 85% by weight of silicate Bentonite 6: 20% by weight of iron oxide and iron sulfide, 80% by weight of silicate Kaolin: 0.1% by weight of iron oxide, 99.9% by weight of silicate

[0051] [Table 1]

[0052] [Table 2]

[0053] [Table 3]

[0054] [Table 4]

[0055] As can be seen from Tables 1 to 3, the anti-adhesion compositions for unvulcanized rubber of Examples 1 to 23 are anti-adhesion compositions for unvulcanized rubber containing an inorganic component and a surfactant, wherein the inorganic component must contain a silicate and at least one selected from iron oxide and iron sulfide, the total weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide and iron sulfide is 10% by weight or less, and the surfactant contains an anionic surfactant (A) and a nonionic surfactant (B), and the weight ratio (A / B), expressed as the weight of (A) / the weight of (B), is 1 to 20, so that the anti-adhesion properties, which are the problem of the present invention, are simultaneously excellent. On the other hand, as can be seen from Table 4, when the total weight ratio of iron oxide and iron sulfide to the total of silicate, iron oxide and iron sulfide exceeds 10% by weight (Comparative Examples 1 and 2), when (A / B) is not in the range of 1 to 20 (Comparative Examples 3, 4, 5, and 6), or when silicate and at least one selected from iron oxide and iron sulfide are not contained (Comparative Examples 7 and 8), at least one of the problems of dispersibility and anti-adhesion, which are the issues of the present invention, cannot be solved. [Industrial applicability]

[0056] The anti-adhesion composition for unvulcanized rubber of the present invention is used in the production and processing of unvulcanized rubber products and can prevent rubber from sticking together when the unvulcanized rubber is stored in stacks until it is moved to the next process such as molding or vulcanization. In this case, it has good dispersibility and anti-adhesion properties, and can reduce defects in rubber products.

Claims

1. An anti-adhesion composition for unvulcanized rubber containing inorganic components and surfactants, The inorganic component essentially includes at least one selected from iron oxide and iron sulfide and a silicate. The sum of the weight ratios of iron oxide and iron sulfide to the total of the silicate, iron oxide and iron sulfide is 1.68% by weight or less, The amount of silicate is 30 to 79.2 parts by weight when the total amount of the inorganic component and the surfactant is 100 parts by weight. An anti-adhesion composition for unvulcanized rubber, wherein the surfactant comprises an anionic surfactant (A) and a nonionic surfactant (B), and the weight ratio (A / B), expressed as the weight of (A) / the weight of (B), is 1 to 20.

2. The anti-adhesion composition for unvulcanized rubber according to claim 1, wherein the amount of the surfactant is 4 to 25 parts by weight when the total amount of the inorganic component and the surfactant is 100 parts by weight.

3. The anti-adhesion composition for unvulcanized rubber according to claim 1 or 2, wherein the weight ratio (A / B) is 1.4 to 9.

4. The anti-adhesion composition for unvulcanized rubber according to any one of claims 1 to 3, wherein the amount of silicate is 30 to 76 parts by weight when the total amount of the inorganic component and the surfactant is 100 parts by weight.

5. The anti-adhesion composition for unvulcanized rubber according to any one of claims 1 to 4, wherein the anionic surfactant (A) comprises a fatty acid soap.

6. A method for producing anti-adhesion treated unvulcanized rubber, comprising a step of applying an anti-adhesion composition for unvulcanized rubber according to any one of claims 1 to 5 to the surface of molded unvulcanized rubber.

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