JP7737522B2 - Anti-adhesive composition for unvulcanized rubber, water-diluted anti-adhesive composition for unvulcanized rubber, and unvulcanized rubber - Google Patents

Description

This disclosure relates to an anti-adhesive composition for unvulcanized rubber, a water-diluted anti-adhesive composition for unvulcanized rubber, and unvulcanized rubber.

At rubber production and processing sites, anti-adhesion agents are applied to the surface of rubber (e.g., unvulcanized rubber) to prevent adhesion (see, for example, Patent Document 1).

JP 2013-001720 A

Smectite, which is highly effective in improving adhesion prevention, is often used as an ingredient in anti-adhesive agents for unvulcanized rubber. Anti-adhesive agents for unvulcanized rubber containing smectite have high viscosity when used as a treatment liquid (aqueous dilution of the anti-adhesive agent composition for unvulcanized rubber). When dried, they form a strong dry film (anti-adhesive coating), resulting in excellent adhesion prevention. On the other hand, if the smectite content (amount) in the anti-adhesive agent for unvulcanized rubber is high, it may bind due to water absorption, which can lead to the risk of solidification (blocking). Furthermore, when the anti-adhesive agent for unvulcanized rubber is dispersed in water and used, the smectite tends to aggregate, resulting in so-called splinters, which can lead to poor dispersion and require a long time to achieve uniform dispersion and dissolution. On the other hand, if the smectite content (amount) in the anti-adhesive agent for unvulcanized rubber is reduced, adhesion prevention properties tend to decrease.

The present disclosure therefore aims to provide an anti-adhesive composition for unvulcanized rubber, an aqueous dilution of the anti-adhesive composition for unvulcanized rubber, and unvulcanized rubber that contain smectite and have excellent solidified disintegration strength, anti-adhesive properties, and redispersibility.

In order to achieve the above object, the anti-adhesive composition for unvulcanized rubber of the present disclosure comprises:
Contains the following components (A) to (E):
The composition is characterized in that the mass ratio (B-1)/(B-2) of the following component (B-1) to the following component (B-2) is 0.2 to 3.
(A) Smectite (B) Inorganic salt containing the following component (B-1) and component (B-2): (B-1) Inorganic sodium salt (B-2) Magnesium carbonate (C) Surfactant (D) Metal soap (E) At least one compound selected from the group consisting of inorganic silicates, metal oxides, and calcium carbonate other than component (A).

The water-diluted anti-adhesive composition for unvulcanized rubber disclosed herein is characterized by containing the anti-adhesive composition for unvulcanized rubber disclosed herein and water.

The unvulcanized rubber disclosed herein is characterized in that the components (A) to (E) of the anti-adhesive composition for unvulcanized rubber disclosed herein are adhered to the surface.

The present disclosure provides an anti-adhesive composition for unvulcanized rubber, a water-diluted anti-adhesive composition for unvulcanized rubber, and unvulcanized rubber that contain smectite and have excellent solidified disintegration strength, anti-adhesive properties, and redispersibility.

The present disclosure will be explained in detail below using examples. However, the present disclosure is not limited to the following explanation.

In this disclosure, "alkyl" includes, for example, straight-chain and branched alkyl. In this disclosure, alkyl groups are not particularly limited, but examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl groups.

In this disclosure, "alkylene" includes, for example, straight-chain alkylene (methylene or polymethylene) and branched alkylene. In this disclosure, alkylene groups are not particularly limited, but examples include methylene, dimethylene (ethylene), ethylidene, trimethylene, 1-methylethylene (propylene), tetramethylene, 1-methyltrimethylene, 2-methyltrimethylene, 1,1-dimethylethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, and decamethylene.

[1. Anti-adhesion agent composition for unvulcanized rubber]
As described above, the anti-adhesive composition for unvulcanized rubber of the present disclosure is characterized in that it contains the following components (A) to (E), and that the mass ratio (B-1)/(B-2) of the following component (B-1) to the following component (B-2) is in the range of 0.2 to 3.

(A) Smectite (B) Inorganic salt containing the following component (B-1) and component (B-2): (B-1) Inorganic sodium salt (B-2) Magnesium carbonate (C) Surfactant (D) Metal soap (E) At least one compound selected from the group consisting of inorganic silicates, metal oxides, and calcium carbonate other than component (A).

[1-1. Component (A): Smectite]
In the anti-adhesive agent for unvulcanized rubber of the present disclosure, the smectite (hereinafter sometimes referred to as "smectite (A)") as component (A) is not particularly limited, and examples thereof include smectites such as montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, stevensite, and bentonite containing montmorillonite. Component (A) may contain only one type of smectite, or two or more types of smectite may be used in combination.

Component (A) functions, for example, as a component responsible for adhesion prevention. Specifically, it is believed that component (A) can exhibit adhesion prevention properties by forming a coating. The content of component (A) in the adhesion-preventing agent for unvulcanized rubber disclosed herein is not particularly limited and can be selected according to the purpose. However, it may be, for example, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, relative to 100% by mass of the total mass of components (A) to (E). It may also be, for example, 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less, relative to 100% by mass of the total mass of components (A) to (E). A content of component (A) of 10% by mass or more is preferred because it provides good adhesion prevention properties. On the other hand, a content of component (A) of 65% by mass or less is preferred because it provides a blocking-suppressing effect in the product. The content (amount) of component (A) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited, but may be, for example, 10 to 65% by mass, 15 to 60% by mass, or 20 to 50% by mass relative to the total mass of the anti-adhesive agent composition for unvulcanized rubber of the present disclosure.

The component (A) (smectite) may be used in the form of an inorganic compound containing smectite (e.g., a powder of the inorganic compound). In this case, the method for measuring the smectite content in the inorganic compound is not particularly limited, but can be measured, for example, by the following measurement method.

(Method for measuring smectite content)
The inorganic compound containing smectite is analyzed by X-ray diffraction, and the smectite content is calculated from the intensity of the diffraction peak due to smectite that appears around 2θ = 7°. The analytical conditions for X-ray diffraction when quantifying the smectite content are as follows.

X-ray diffraction analysis conditions and measuring device: X'Pert PRO MRD (manufactured by PANalytical)
Target: Cu
Tube voltage: 45 kV
・Tube current: 40mA
Scan axis: Gonio Scan range: 5° to 60°
Step size: 0.03°
Step time: 12.7 seconds Divergence slit: 1/2°
Scattering slit: 1°
- Receiving slit: None

[1-2. Component (B): Inorganic salt (component (B-1) and component (B-2))]
In the anti-adhesive agent for unvulcanized rubber of the present disclosure, the inorganic salt that is component (B) (hereinafter, may be referred to as "inorganic salt (B)") includes, as described above, an inorganic sodium salt (component (B-1)) and magnesium carbonate (component (B-2)). The inorganic sodium salt (component (B-1)) is not particularly limited and includes, for example, the following:

Component (B-1) may be, for example, at least one inorganic sodium salt selected from sodium carbonate, sodium chloride, sodium phosphate, and sodium sulfate. Sodium carbonate, sodium chloride, and sodium phosphate are particularly preferred in terms of their effectiveness in improving adhesion prevention.

The combined use of inorganic sodium salt (component (B-1)) and magnesium carbonate (component (B-2)), for example, is believed to improve adhesion prevention by increasing the adhesion amount through thickening of the aqueous diluted solution of the anti-adhesive agent for unvulcanized rubber of the present disclosure, and to improve redispersibility by promoting aggregation of component (A). The content of component (B-1) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited and can be selected according to the purpose. It may be, for example, 0.2% by mass or more, 0.5% by mass or more, 1% by mass or more, 1.2% by mass or more, or 1.5% by mass or more, relative to 100% by mass of the total mass of components (A) to (E). It may also be, for example, 10% by mass or less, 5% by mass or less, 4% by mass or less, or 3.5% by mass or less. The content of component (B-2) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited and can be selected according to the purpose. For example, it may be 0.2% by mass or more, 0.5% by mass or more, 1% by mass or more, 1.2% by mass or more, or 1.5% by mass or more, relative to 100% by mass of the total mass of components (A) to (E). It may also be 10% by mass or less, 5% by mass or less, 4% by mass or less, or 3.5% by mass or less. When the content of component (B-1) and component (B-2) is 0.2% by mass or more, relative to 100% by mass of the total mass of components (A) to (E), it is preferable because improved adhesion prevention and redispersibility can be obtained. On the other hand, when the content of component (B-1) and component (B-2) is 10% by mass or less, it is preferable because improved adhesion prevention and redispersibility can be achieved. The total content of component (B-1) and component (B-2) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited, and may be, for example, 1 to 12 mass%, 1.5 to 10 mass%, or 2 to 8 mass%, relative to the total mass of the anti-adhesive agent composition for unvulcanized rubber of the present disclosure. It is preferable that the total content of component (B-1) and component (B-2) be, for example, 1 to 12 mass%, 1.5 to 10 mass%, or 2 to 8 mass%, relative to 100 mass%, the total mass of components (A) to (E), because this will result in improved adhesion prevention and redispersibility.

On the other hand, since component (B-1) promotes blocking of the product due to moisture absorption, in order to impart a blocking suppression effect, the mass ratio (B-1)/(B-2) of component (B-1) to component (B-2) is set to 0.2 to 3 as described above, and may be, for example, 0.3 to 3, 0.5 to 2, or 0.6 to 1.7.

[1-3. Component (C): Surfactant]
In the anti-adhesive agent for unvulcanized rubber of the present disclosure, the surfactant (C) (component (C)) functions to impart, for example, wettability and dispersibility in water to the anti-adhesive agent for unvulcanized rubber. The surfactant (C) (component (C)) is not particularly limited, and examples include the following (1) to (5). Furthermore, as the surfactant (C), only one type of surfactant may be used, or two or more types may be used in combination.
(1) Carboxylic acid type anionic surfactants such as higher fatty acid salts, alkyl ether carboxylates, polyoxyalkylene ether carboxylates, alkyl (or alkenyl) amide ether carboxylates, and acylamino carboxylates. (2) Sulfate type anionic surfactants such as higher alcohol sulfates, polyoxyalkylene higher alcohol sulfates, alkyl phenyl ether sulfates, polyoxyalkylene alkyl phenyl ether sulfates, and glycerin fatty acid ester monosulfate salts. (3) Sulfonic acid type anionic surfactants such as alkanesulfonates, α-olefin sulfonates, linear alkylbenzene sulfonates, α-sulfofatty acid ester salts, and dialkyl sulfosuccinates. (4) Phosphate type anionic surfactants such as alkyl phosphate esters, polyoxyalkylene alkyl phosphate esters, polyoxyalkylene alkylphenyl phosphate esters, and glycerin fatty acid ester monophosphate salts. (5) Polyoxyalkylene alkyl ether type nonionic surfactants.

The counter ion of the anionic surfactant is not particularly limited, but alkali metals such as sodium and potassium, and alkanolamines such as monoethanolamine and diethanolamine are preferred. These may be used alone or in combination of two or more.

As an anionic surfactant, a sulfonic acid or sulfate type anionic surfactant is preferred, as this will result in an anti-adhesive agent suspension (water-diluted solution) that has superior wettability with the surface of unvulcanized rubber. α-olefin sulfonate and dialkyl sulfosuccinate are preferred. As an α-olefin sulfonate, sodium α-olefin sulfonate "Lipolan (registered trademark) LB-840" (manufactured by Lion Specialty Chemicals Co., Ltd.) is a more preferred example, and as a dialkyl sulfosuccinate, sodium dioctyl sulfosuccinate is a more preferred example.

The nonionic surfactant is not particularly limited, and in the present disclosure, for example, a nonionic surfactant represented by the following formula (1) can be used. It is presumed that the nonionic surfactant of the following formula (1), together with the anionic surfactant, not only reduces the surface tension of the anti-adhesive agent suspension (aqueous dispersion) relative to the surface of the unvulcanized rubber, but also effectively increases the adhesion of the anti-adhesive agent to the surface of the unvulcanized rubber. However, this presumption does not limit the present disclosure in any way.

RO-(AO)n-H (1)

In the formula (1), R represents an aliphatic hydrocarbon group having 8 to 18 carbon atoms. The aliphatic hydrocarbon group may be linear or branched. It may also be saturated or unsaturated. The number of carbon atoms in R is preferably 12 to 16, and more preferably 12 to 13, from the viewpoint of excellent dispersibility of the component (A).
AO represents an oxyalkylene group having 2 to 4 carbon atoms, and n represents the average number of moles of AO added.
n may be, for example, 1 to 30, 1 to 25, or 1 to 20. Specifically, from the viewpoint of preventing a decrease in surfactant activity and a decrease in the dispersibility of the component (A), n is preferably 1 or greater (i.e., not 0). Furthermore, from the viewpoint of preventing a decrease in adhesion due to excessive hydrophilicity, n is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less. It is presumed that when n is preferably in the range of 1 to 30, more preferably in the range of 1 to 25, and even more preferably in the range of 1 to 20, the dispersibility of the component (A) is further improved, and even when the unvulcanized rubber surface is highly hydrophobic, sufficient viscoelasticity is imparted to the coating, thereby improving adhesion. However, this presumption does not limit the present disclosure in any way.

An oxyalkylene group having 2 to 4 carbon atoms is, for example, a polymerized unit formed by addition polymerization of an alkylene oxide having 2 to 4 carbon atoms. Specific examples of oxyalkylene groups having 2 to 4 carbon atoms include an oxyethylene group (EO) formed by addition of ethylene oxide, an oxypropylene group (PO) formed by addition of propylene oxide, and an oxybutylene group (BO) formed by addition of butylene oxide. (AO)n contains at least an oxyethylene group (EO) in its structure, and may contain only an oxyethylene group (EO), or may contain an oxyethylene group (EO) and another oxyalkylene group. When (AO)n contains multiple types of oxyethylene groups (EO), oxypropylene groups (PO), and oxybutylene groups (BO), these groups may be arranged in a block or random configuration. (AO)n preferably consists solely of oxyethylene groups (EO), for example, in view of achieving an excellent balance between hydrophilicity and hydrophobicity.

The content of component (C) in the anti-adhesive agent for unvulcanized rubber disclosed herein is not particularly limited and can be selected according to the purpose. It may be, for example, 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, or 5% by mass or more, relative to 100% by mass of the total mass of components (A) to (E). It may also be, for example, 25% by mass or less, 20% by mass or less, 15% by mass or less, or 12% by mass or less. If the content of surfactant (C) is at or above the lower limit, problems such as cissing due to insufficient wettability of the anti-adhesive liquid (water-diluted anti-adhesive composition) to the rubber are unlikely to occur. If the content is at or below the upper limit, problems such as excessive foaming and overflow from equipment during use are unlikely to occur. The content (amount) of component (C) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited, but may be, for example, 1 to 25% by mass, 2 to 20% by mass, or 3 to 15% by mass relative to the total mass of the anti-adhesive agent composition for unvulcanized rubber of the present disclosure.

[1-4. Component (D): Metal Soap]
[Component (D)]
The at least one metal soap (D) selected from the group consisting of zinc, magnesium, and aluminum (component (D), hereinafter also referred to as "metal soap (D)") is not particularly limited, and examples thereof include zinc caprylate, magnesium caprylate, zinc caprate, magnesium caprate, zinc laurate, magnesium laurate, zinc myristate, magnesium myristate, zinc palmitate, magnesium palmitate, zinc stearate, magnesium stearate, aluminum stearate, aluminum trioctadecanoate, aluminum dioctadecanoate, aluminum monooctadecanoate, zinc octadecanoate, magnesium octadecanoate, and aluminum octadecanoate. Examples of suitable metal soaps include at least one metal soap selected from the group consisting of zinc leate, magnesium oleate, zinc behenate, magnesium behenate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, zinc 14-octadecanoate, magnesium 14-octadecanoate, zinc 8-octadecanoate, magnesium 8-octadecanoate, zinc 6-octadecanoate, magnesium 6-octadecanoate, zinc coconut fatty acid, magnesium coconut fatty acid, zinc palm oil fatty acid, magnesium palm oil fatty acid, zinc palm kernel oil fatty acid, magnesium palm kernel oil fatty acid, zinc beef tallow fatty acid, magnesium beef tallow fatty acid, zinc castor oil fatty acid, and magnesium castor oil fatty acid. From the viewpoint of improving adhesion prevention, the metal soap (D) is preferably at least one metal soap selected from the group consisting of calcium fatty acids having 12 to 18 carbon atoms and zinc fatty acids having 12 to 18 carbon atoms, with calcium stearate being particularly preferred.

By including metal soap (D) in the anti-adhesive agent for unvulcanized rubber of the present disclosure together with component (A), it is believed that the hardness of the dried coating of the anti-adhesive agent formed on the surface of the unvulcanized rubber is reduced, reducing the amount of foreign matter in the rubber, while still maintaining sufficient anti-adhesive properties. Metal soap (D) also improves anti-adhesive properties, lubricity, and powder flowability.

The content of component (D) in the anti-adhesive agent for unvulcanized rubber disclosed herein is not particularly limited and can be selected according to the purpose. It may be, for example, 5% by mass or more, 7% by mass or more, 8% by mass or more, or 10% by mass or more, relative to 100% by mass of the total mass of components (A) to (E). It may also be, for example, 30% by mass or less, 20% by mass or less, or 15% by mass or less. Setting the content of component (D) at or above the lower limit relative to 100% by mass of the total mass of components (A) to (E) is preferred because it provides good anti-adhesive properties and improves the sliding properties between the product and its storage container, and between the rubber and equipment. On the other hand, a content of component (D) at or below the upper limit is preferred because it leads to cost reduction. The content (amount) of component (D) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited, but may be, for example, 5 to 30 mass%, 10 to 20 mass%, or 10 to 15 mass% relative to the total mass of the anti-adhesive agent composition for unvulcanized rubber of the present disclosure.

The mass ratio (A)/(D) of component (A) to component (D) is, for example, 0.3 to 10, and may be 0.6 to 7, or 1 to 5. When the mass ratio (A)/(D) is within the above range, the effects of the presently disclosed invention, namely, excellent solidified product disintegration strength, anti-adhesion properties, and redispersibility, are easily achieved. The mass ratio (B)/(D) of component (B) to component (D) is, for example, 0.03 to 3, and may be 0.06 to 2, or 0.1 to 1. When the mass ratio (B)/(D) is within the above range, the effects of the presently disclosed invention, namely, excellent solidified product disintegration strength, anti-adhesion properties, and redispersibility, are easily achieved.

[1-5. Component (E)]
In the anti-adhesive agent for unvulcanized rubber of the present disclosure, at least one compound (E) selected from the group consisting of inorganic silicates, metal oxides, and calcium carbonate (component (E)) other than component (A) is thought to function, for example, mainly as a lubricant (to impart slipperiness) and also to contribute to improving powder flowability.

In component (E), the inorganic silicate is not particularly limited and examples include silicates such as kaolin (also known as kaolin clay), aluminum silicate, calcium silicate, clay, talc, mica, sericite, nepheline, and syenite. The metal oxide is not particularly limited and examples include metal oxides such as silica, alumina, magnesium oxide, antimony trioxide, titanium oxide, white carbon, and iron oxide.

The content of component (E) in the anti-adhesive agent for unvulcanized rubber of the present disclosure is not particularly limited and can be selected according to the purpose. It may be, for example, 0.1% by mass or more, 1% by mass or more, 5% by mass or more, 10% by mass or more, or 20% by mass or more, relative to 100% by mass of the total mass of components (A) to (E), or may be, for example, 76% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less. A content of component (E) at or above the lower limit is preferred because it tends to improve the sliding properties between the product and its storage container, and between the rubber and equipment, and also leads to cost savings.

When calcium carbonate is included as component (E), the calcium carbonate content may be, for example, 20% by mass or more, 30% by mass or more, 40% by mass or more, 50% by mass or more, 75% by mass or more, or 90% by mass or more, relative to 100% by mass of the total mass of component (E). When the calcium carbonate content is equal to or greater than the lower limit, for example, the hardness of the dried coating can be reduced, and foreign matter in the rubber can be reduced.

The mass ratio (D)/(E) of component (D) to component (E) may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, or 0.4 or more, and may be, for example, 20 or less, 15 or less, 10 or less, 5 or less, 3 or less, 1 or less, or 0.5 or less. When the mass ratio (D)/(E) is within the above range, for example, it is possible to achieve both excellent adhesion prevention and reduced foreign matter.

[1-6. Optional ingredients, etc.]
The adhesion-preventive composition for unvulcanized rubber of the present disclosure may or may not contain optional components other than the components (A) to (E) described above. For example, the adhesion-preventive composition for unvulcanized rubber of the present disclosure may contain additives such as antifoaming agents, preservatives, wettability aids, viscosity aids, and foreign matter reduction aids as optional components, as needed.

Examples of defoaming agents include, but are not limited to, oil-based defoaming agents such as castor oil, sesame oil, linseed oil, and animal and vegetable oils; fatty acid ester-based defoaming agents such as isoamyl stearate, distearyl succinate, ethylene glycol distearate, and butyl stearate; alcohol-based defoaming agents such as polyoxyalkylene monohydric alcohol, di-t-amylphenoxyethanol, 3-heptanol, and 2-ethylhexanol; ether-based defoaming agents such as di-t-aminophenoxyethanol, 3-heptyl cellosolve, nonyl cellosolve, and 3-heptyl carbitol; phosphate ester-based defoaming agents such as tributyl phosphate and tris(butoxyethyl)phosphate; amine-based defoaming agents such as diamylamine; amide-based defoaming agents such as polyalkylene amides and acylate polyamines; mineral oil; and silicone oil. These defoaming agents may be used alone or in combination.

Preservatives include, but are not limited to, derivatives of isothiazolinone, pyridine, and iodine. The isothiazolinone derivatives include, but are not limited to, benzisothiazolinone (BIT), methylisothiazolinone (MIT, MI), chloromethylisothiazolinone (CMIT, CMI), octylisothiazolinone (OIT, OI), dichlorooctylisothiazolinone (DCOIT, DCOI), and their derivatives. The pyridine derivatives include, but are not limited to, pyridinethiol and its derivatives. The iodine derivatives include, but are not limited to, iodo-2-propargylbutylcarbamic acid and its derivatives. For example, the preservatives may be used alone or in combination.

While not particularly limited, the wettability aid may include, for example, alcohols. More specifically, examples include methanol, ethanol, hexanol, glycerin, 1,3-butanediol, propylene glycol, dipropylene glycol, pentylene glycol, hexylene glycol, polyethylene glycol, sorbitol, maltitol, sucrose, erythritol, xylitol, polyethylene glycol, polypropylene glycol, and ethylene oxide or propylene oxide adducts of polyhydric alcohols. One type of the wettability aid may be used alone, or multiple types may be used in combination.

The anti-adhesive agent for unvulcanized rubber disclosed herein is preferably in the form of powder, granules, or granules. The average particle size of the anti-adhesive agent is preferably 0.003 to 30 mm, more preferably 0.003 to 25 mm, and even more preferably 0.005 to 20 mm. If it is above the lower limit of the above range, it is less likely to scatter, and if it is below the upper limit, it is less likely to solidify. The average particle size of the powdered anti-adhesive agent for unvulcanized rubber is preferably 0.005 to 0.2 mm, and more preferably 0.005 to 0.1 mm.

[2. Method for producing anti-adhesive composition for unvulcanized rubber]
The method for producing the anti-adhesive agent composition for unvulcanized rubber of the present disclosure is not particularly limited, but can be, for example, produced by mixing all components of the anti-adhesive agent for unvulcanized rubber, i.e., components (A) to (E), with optional components added as needed. Examples of the mixing device include a device equipped with a stirring blade inside a container. Specific examples include powder mixers capable of oscillating or stirring, such as ribbon mixers and vertical screw mixers. Multifunctional powder mixers combining multiple stirring devices, such as Super Mixer (manufactured by Kawata Co., Ltd.), High Speed Mixer (manufactured by Earth Technica Co., Ltd.), New Gram Machine (manufactured by Seishin Enterprise Co., Ltd.), and SV Mixer (manufactured by Kobelco Eco Solutions Co., Ltd.), can also be used. Dry crushers such as jaw crushers, gyratory crushers, cone crushers, roll crushers, impact crushers, hammer crushers, rod mills, ball mills, vibrating rod mills, vibrating ball mills, disc mills, jet mills, and cyclone mills may also be used.

[3. Method of using anti-adhesive composition for unvulcanized rubber]
The method of using the adhesion-preventive composition for unvulcanized rubber of the present disclosure is not particularly limited, and may be the same as or equivalent to the method of using a general adhesion-preventive composition for unvulcanized rubber. Specific examples of the method of using the adhesion-preventive composition for unvulcanized rubber of the present disclosure are as follows, but are not limited thereto.

The method for preventing adhesion of unvulcanized rubber using the disclosed anti-adhesive composition for unvulcanized rubber may, for example, as described above, include an adhesion prevention treatment step in which components (A) to (E) of the disclosed anti-adhesive composition for unvulcanized rubber are adhered to the surface of the unvulcanized rubber to perform adhesion prevention treatment. Adhesion to the surface of the unvulcanized rubber can be performed, for example, by a wet method, as described below. Unvulcanized rubber that has been treated in this way for adhesion prevention does not adhere to each other, even when stored, for example, stacked or folded. Furthermore, such an adhesion prevention treatment method for unvulcanized rubber can also be considered, for example, a method for producing anti-adhesive-treated unvulcanized rubber.

The anti-adhesive composition for unvulcanized rubber of the present disclosure may be used as is, or may be further diluted with water and used in the form of a water-diluted solution (water dilution). The concentration of the anti-adhesive composition for unvulcanized rubber of the present disclosure when applied to the surface of unvulcanized rubber is not particularly limited. The total mass of components other than water relative to the total mass of the anti-adhesive composition for unvulcanized rubber may be, for example, 0.5% by mass or more, 1% by mass or more, or 2% by mass or more, and may be, for example, 15% by mass or less, 10% by mass or less, or 5% by mass or less. If the concentration is not too high, for example, low scattering and fast drying can be achieved. If the concentration is not too low, for example, high anti-adhesive properties and high lubricity can be achieved. The anti-adhesive composition for unvulcanized rubber of the present disclosure can exhibit high anti-adhesive properties even when applied to the surface of unvulcanized rubber at a low concentration, and therefore can exhibit high anti-adhesive properties with a small amount of application. The viscosity when applied to the surface of unvulcanized rubber is not particularly limited, but may be, for example, 1 mPa·s or more, 5 mPa·s or more, or 10 mPa·s or more, or may be, for example, 30 mPa·s or less, 20 mPa·s or less, or 15 mPa·s or less. If the viscosity is not too high, for example, effects such as low scattering and fast drying can be achieved. If the viscosity is not too low, for example, effects such as high adhesion resistance and high slipperiness can be achieved.

The adhesion-preventing treatment step may be, for example, as described above, a step of adhering the disclosed adhesion-preventing composition for unvulcanized rubber or a water-diluted solution of the disclosed adhesion-preventing composition for unvulcanized rubber to the surface of the unvulcanized rubber, and then volatilizing the water, thereby adhering components (A) to (E) of the disclosed adhesion-preventing composition for unvulcanized rubber to the surface of the unvulcanized rubber. More specifically, the adhesion-preventing treatment step may include, for example, an adhesion-preventing composition adhering step of adhering the disclosed adhesion-preventing composition for unvulcanized rubber to the surface of the unvulcanized rubber, and a drying step of drying the adhesion-preventing composition for unvulcanized rubber on the surface of the unvulcanized rubber to form a coating on the surface of the unvulcanized rubber. Such an adhesion-preventing treatment step is referred to, for example, as a wet method. The wet method is not particularly limited, and may be performed, for example, in the same manner as a general wet method for adhering an adhesion-preventing composition for unvulcanized rubber.

In the step of applying the anti-adhesive composition for unvulcanized rubber, it is preferable to apply the anti-adhesive composition for unvulcanized rubber to unvulcanized rubber that is in a high-temperature state (e.g., about 80 to 150°C) due to the heat generated when it is molded into a sheet or the like.

Specific methods for the step of applying the adhesion-preventive composition for unvulcanized rubber include, for example, spraying the adhesion-preventive composition for unvulcanized rubber onto the unvulcanized rubber using a shower device, or a dipping method in which the unvulcanized rubber is immersed for a short period of time in a tank containing the adhesion-preventive composition for unvulcanized rubber. It is also possible to use a method in which the adhesion-preventive composition for unvulcanized rubber is applied to the unvulcanized rubber using an applicator, and these methods may be used in combination as appropriate.

As described above, the anti-adhesive composition for unvulcanized rubber disclosed herein has excellent anti-adhesive effects and defoaming properties.

There are no particular restrictions on the type of rubber to which the disclosed anti-adhesive agent composition for unvulcanized rubber can be applied, as long as it is unvulcanized rubber. Examples of such rubber types include natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), IIR (butyl rubber), EPDM (ethylene propylene rubber), and rubbers that are mixtures of multiple types of these.

Next, examples of the present disclosure will be described. However, the present disclosure is not limited to the following examples.

[Examples 1 to 40 and Comparative Examples 1 to 6]
Each component was kneaded in the weight (mass) ratio shown in Tables 1 to 5 below to prepare a powdered anti-adhesive agent for unvulcanized rubber (hereinafter also referred to as anti-adhesive agent) for each example, consisting of a uniform powder. Each resulting anti-adhesive agent was then added to tap water with stirring to prepare a water-diluted anti-adhesive agent composition with a concentration of 3% by mass. In Examples 1 to 40, all of the components (A) to (E) were blended as shown in Tables 1 to 4 below. In contrast, as shown in Table 5 below, of the components (A) to (E), Comparative Example 1 did not blend component (B-1), and Comparative Example 2 did not blend component (B-2). In Comparative Examples 3 to 5, all of the components (A) to (E) were blended, but the mass ratios (B-1)/(B-2) were 5.0, 0.15, and 4.0, respectively. In Comparative Example 6, of the components (A) to (E), component (D) was not blended. The product names (trade names) and manufacturers of each component listed in Tables 1 to 5 below are shown in Table 6 below.

<Evaluation>
(1) Rubber for Evaluation In various evaluations, the following unvulcanized SBR rubber and unvulcanized NR rubber were used as rubber for evaluation.

(Unvulcanized SBR rubber)
Unvulcanized SBR rubber was used, in which 100 parts by mass of SBR (manufactured by Asahi Kasei Corporation, trade name "Tufden 4850") was blended with 30 parts by mass of SAF carbon (manufactured by Mitsubishi Chemical Corporation, trade name "Diablack A"), 15 parts by mass of JSRAROMA (process oil) (manufactured by Japan Sun Oil Co., Ltd., trade name "Aroma 790"), 3 parts by mass of zinc oxide (manufactured by Hakusui Tech Co., Ltd., zinc oxide type 2), 1 part by mass of stearic acid (manufactured by NOF Corporation, camellia), 1 part by mass of 6PPD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Nocrac 6C"), 1 part by mass of CBS (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Noccela CZ-G"), and 1.5 parts by mass of sulfur (manufactured by Tsurumi Chemical Co., Ltd.) (total 151.5 parts by mass).

(Unvulcanized NR rubber)
For 100 parts by mass of NR (RSS#3), 10 parts by mass of white carbon (manufactured by Tosoh Silica Corporation, trade name "Nipsil VN-3"), 30 parts by mass of ISAF black (manufactured by Tokai Carbon Co., Ltd., trade name "Seat 6"), 15 parts by mass of JSRAROMA (process oil) (manufactured by Japan Sun Oil Co., Ltd., trade name "Aroma 790"), 3 parts by mass of zinc oxide (manufactured by Hakusui Tech Co., Ltd., zinc oxide type 2), 1 part by mass of stearic acid (manufactured by NOF Corporation, camellia), 1 part by mass of 6PPD (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Nocrac 6C"), 1 part by mass of CBS (manufactured by Ouchi Shinko Chemical Industry Co., Ltd., trade name "Noccela CZ-G"), and 1.5 parts by mass of sulfur (manufactured by Tsurumi Chemical Co., Ltd.) were blended (total 162.5 parts by mass) of unvulcanized NR rubber.

(2) Evaluation of Anti-Adhesion Properties The unvulcanized rubber was kneaded with an open roll at a temperature of 80 to 120°C to form a rubber sheet (thickness: 5 to 8 mm, 60 cm x 15 cm). Immediately after being unwound, the rubber sheet was immersed for approximately 1 second in 1 L of an aqueous solution (temperature: 40°C) of the anti-adhesive agent obtained by stirring and dispersing the anti-adhesive agent composition for unvulcanized rubber obtained in each of Examples 1 to 40 and Comparative Examples 1 to 6 in water to a concentration of 3% by mass for at least 1 hour. The rubber sheet was then quickly pulled up vertically, left standing in a vertical position at room temperature, and allowed to dry naturally. In this way, the anti-adhesive treatment of the rubber sheet (unvulcanized rubber) was performed. The rubber sheet was then cut into 6 cm x 15 cm pieces, and two pieces were stacked together to form a laminate. A load of 1 t/ ^m² was applied vertically from one side to the laminated test specimen, and the laminated test specimen was left at 60°C for 12 hours. Thereafter, the test piece was returned to room temperature and subjected to a 180° peel test using a tensile tester (AGS-500D, Shimadzu Corporation) to measure the peel resistance (N/cm) at a pulling rate of 300 mm/min.

(3) Evaluation of redispersibility A water-diluted solution of the anti-adhesive agent for unvulcanized rubber was prepared in the same manner as in "(2) Evaluation of adhesion prevention" above. Next, the water-diluted solution (suspension) of the anti-adhesive agent for unvulcanized rubber was placed in a 100 ml measuring cylinder, shaken up and down 10 times, and then allowed to stand in a thermostatic chamber at 20°C. After 24 hours, the measuring cylinder was shaken up and down, and the number of shakes required until the solid content at the bottom of the measuring cylinder was completely dispersed was measured. The fewer the number of shakes, the better the redispersibility was judged to be.

(4) Powder discharge performance (powder fluidity)
The anti-adhesive agent compositions for unvulcanized rubber obtained in each of Examples 1 to 40 and Comparative Examples 1 to 6 were filled into 500 mL resin containers with a discharge port diameter of 2.2 cm and an inclination angle of 50°, and the powder surface was smoothed by tapping. The containers were then left to stand in a humid heat storage cabinet (IG-401, YAMATO) adjusted to a temperature of 40°C and a humidity of 90% RH. After 7 days, the containers were removed, and with the discharge port open, the containers were struck with a metal rod, and the discharge behavior of the powder was visually observed. The evaluation criteria are as follows:
○: Full discharge possible ×: Full discharge impossible (blocking)

(5) Solidified product collapse strength (blocking property)
The anti-adhesive agent compositions for unvulcanized rubber obtained in each of Examples 1 to 40 and Comparative Examples 1 to 6 were filled into a circular resin container having an inner diameter of 3.2 cm and a height of 1.9 cm. After smoothing the powder surface by tapping, the container was left to stand in a humid heat storage cabinet (IG-401, Yamato) adjusted to a temperature of 40°C and a humidity of 90% RH. After 7 days, the powder solid was removed from the container, and with a circular resin plate having a diameter of 3.2 cm placed on top of the powder solid, it was crushed using a round spring-type rod-shaped tension gauge (Ohba Keiki) and the weight (kg) at the time of collapse was measured.

Tables 1 to 5 summarize the types and compositions of raw materials used in the anti-adhesive compositions for unvulcanized rubber in Examples 1 to 40 and Comparative Examples 1 to 6, as well as the evaluation results for anti-adhesive properties and foaming properties, as evaluated as described above.

As shown in Tables 1 to 5, the anti-adhesive compositions for unvulcanized rubber of Examples 1 to 40 were excellent in all aspects of adhesion prevention, redispersibility, and solidified product disintegration strength (blocking resistance). In contrast, the anti-adhesive compositions for unvulcanized rubber of Comparative Examples 1 and 3 were inferior in redispersibility compared to the Examples. The anti-adhesive compositions for unvulcanized rubber of Comparative Examples 2, 4, and 6 were inferior in adhesion prevention compared to the Examples. The anti-adhesive composition for unvulcanized rubber of Comparative Example 5 was inferior in redispersibility and solidified product disintegration strength compared to the Examples. In addition, the anti-adhesive compositions for unvulcanized rubber of Comparative Examples 5 and 6 were inferior in powder dischargeability compared to the Examples.

<Additional Notes>
Some or all of the above embodiments and examples may be described as, but are not limited to, the following supplementary notes.
(Appendix 1)
Contains the following components (A) to (E):
An anti-adhesive composition for unvulcanized rubber, characterized in that the mass ratio (B-1)/(B-2) of the following component (B-1) to the following component (B-2) is 0.2 to 3:
(A) smectite; (B) inorganic salt containing the following component (B-1) and component (B-2): (B-1) inorganic sodium salt; (B-2) magnesium carbonate; (C) surfactant; (D) metal soap; and (E) at least one compound selected from the group consisting of inorganic silicates, metal oxides, and calcium carbonate other than component (A) (Appendix 2).
With respect to 100% by mass of the total mass of the components (A) to (E),
10 to 50% by mass of the component (A),
1 to 5% by mass of the component (B-1),
1 to 5% by mass of the component (B-2),
2 to 25 mass% of the component (C),
10 to 30 mass% of the component (D),
0.1 to 76% by mass of the component (E),
Attachment 1: The anti-adhesive composition for unvulcanized rubber according to claim 1, comprising:
(Appendix 3)
3. A water-diluted anti-adhesive composition for unvulcanized rubber, comprising the anti-adhesive composition for unvulcanized rubber according to claim 1 or 2, and water.
(Appendix 4)
3. An unvulcanized rubber having the components (A) to (E) in the anti-adhesive composition for unvulcanized rubber according to claim 1 or 2 adhered to the surface thereof.

Claims (6)

Contains the following components (A) to (E):
the mass ratio (B-1)/(B-2) of the following component (B-1) to the following component (B-2) is 0.2 to 3;
With respect to 100% by mass of the total mass of the following components (A) to (E),
10 to 50% by mass of the following component (A),
1 to 5% by mass of the following component (B-1),
1 to 5 mass% of the following component (B-2),
2 to 25% by mass of the following component (C),
10 to 30% by mass of the following component (D),
0.1 to 50% by mass of the following component (E),
Including,
The component (E) contains calcium carbonate,
An anti-adhesive composition for unvulcanized rubber, characterized in that the content of the calcium carbonate is 20% by mass or more relative to 100% by mass of the total mass of the component (E) .
(A) smectite; (B) inorganic salt containing the following component (B-1) and component (B-2): (B-1) inorganic sodium salt; (B-2) magnesium carbonate; (C) surfactant; (D) metal soap ; (E) calcium carbonate, and optionally at least one compound selected from the group consisting of inorganic silicates and metal oxides other than component (A). 2. The anti-adhesive composition for unvulcanized rubber according to claim 1, wherein the component (D) is a calcium salt of a fatty acid having 12 to 18 carbon atoms . 2. The anti-adhesive composition for unvulcanized rubber according to claim 1, wherein the mass ratio (A)/(D) of the component (A) to the component (D) is 1 to 5. 2. The anti-adhesive composition for unvulcanized rubber according to claim 1, wherein the mass ratio (D)/(E) of the component (D) to the component (E) is 0.2 to 1. 5. A water-diluted anti-adhesive composition for unvulcanized rubber, comprising the anti-adhesive composition for unvulcanized rubber according to claim 1 and water. 5. An unvulcanized rubber having the components (A) to (E) in the adhesion preventive composition for unvulcanized rubber according to any one of claims 1 to 4 adhered to the surface thereof.