WO2013133207A1

WO2013133207A1 - Anti-tack agent for unvulcanized rubbers, and method for producing anti-tack-treated unvulcanized rubber

Info

Publication number: WO2013133207A1
Application number: PCT/JP2013/055831
Authority: WO
Inventors: 石川　浩; 友一小熊; 孝介市橋; 栄志森口; 保昌石原
Original assignee: 一方社油脂工業株式会社
Priority date: 2012-03-06
Filing date: 2013-03-04
Publication date: 2013-09-12
Also published as: JP2013213202A; CN104159961B; CN104159961A; JP5998079B2

Abstract

The present invention relates to an anti-tack agent for unvulcanized rubbers, which comprises a bentonite (A) in an amount of 50 to 90 mass% relative to the total amount of the anti-tack agent for unvulcanized rubbers, an anionic surfactant (B) and a nonionic surfactant (C) represented by formula (1), wherein the bentonite (A) contains Na-type montmorillonite in an amount of 60 mass% or more relative to the total amount of the bentonite and the ratio of the content of the anionic surfactant (B) to the content of the nonionic surfactant (C) (i.e., B/C) is 0.15 to 0.65 by mass. R(AO)_nH (1) In the formula, R represents an aliphatic hydrocarbon group having 8 to 18 carbon atoms; AO represents an oxyalkylene group having 2 to 4 carbon atoms; n refers to the average molar number of AO groups added and represents a numeral value of 1 to 8; and (AO)_n contains at least an oxyethylene group.

Description

Anti-curing agent for unvulcanized rubber and method for producing non-vulcanized rubber having been subjected to anti-adhesion treatment

The present invention relates to an adhesion preventive agent for preventing adhesion between unvulcanized rubbers, and a method for producing an adhesion-treated unvulcanized rubber using the same.
This application claims priority based on Japanese Patent Application No. 2012-049000 filed in Japan on March 6, 2012, the contents of which are incorporated herein by reference.

For example, in the field of production and processing of rubber such as natural rubber (NR) and butadiene rubber (BR), unvulcanized rubber molded into a sheet or the like is transferred to the next molding and vulcanization process. In the meantime, they may be stacked or folded for storage. At the time of such storage, for the purpose of preventing the unvulcanized rubber from adhering to each other, an adhesion preventing agent (adhesion preventing agent) is adhered to the surface of the unvulcanized rubber (for example, (See Patent Document 1).

There is a wet method using a suspension in which an anti-adhesive agent is dispersed in water at a concentration of about 2 to 3% by mass as a method for attaching the anti-adhesive agent to the surface of an unvulcanized rubber. In the wet method, the suspension is sprayed with shower equipment on unvulcanized rubber in a high temperature state (for example, 80 to 150 ° C.) after being formed into a sheet or the like, or in a tank containing the suspension. The suspension is attached to the surface of the unvulcanized rubber by dipping the unvulcanized rubber in a high temperature state for a short time. Moisture in the adhering suspension is rapidly evaporated and dried by the heat of the unvulcanized rubber, thereby forming a film of an adhesion-preventing agent on the surface of the unvulcanized rubber.

JP 2009-249533 A

However, in such a wet method, even if the wettability between the adhesion-suspending agent suspension and the surface of the unvulcanized rubber is insufficient or the wettability is relatively good, the wet method is in a high temperature state. Under conditions where the suspension is rapidly dried by the heat of the unvulcanized rubber, the suspension is repelled in the drying process, and the adhesion agent is not evenly adhered to the surface of the unvulcanized rubber. It was difficult. If there is uneven adhesion of the anti-adhesive agent, it is difficult to fully exhibit the anti-adhesion performance.

Also, in recent years, work sites where anti-adhesive agents are used have been required to improve workability. Specifically, the anti-adhesive agents are adhered to the rubber surface by reducing the concentration of the anti-adhesive agent in the suspension. A method of reducing the amount of the agent is taken. Also, since the anti-adhesive agent adhering to the surface of the unvulcanized rubber is kneaded into the rubber in the next step, the amount of the anti-adhesive agent adhering to the unvulcanized rubber is made as small as possible, and the anti-adhesive agent is the rubber. It is preferable not to adversely affect the physical properties.
However, when a suspension with a low concentration of the anti-adhesive agent is used in this way, the deterioration of the anti-adhesion performance due to uneven adhesion of the anti-adhesive agent is more significant than when a suspension with a high concentration of the anti-adhesive agent is used. There was a tendency to become.
More recently, the diversification of rubber types has increased the number of unvulcanized rubbers with complex surface conditions, and cases have been recognized in which adherents are less likely to adhere.

The present invention has been made in view of the above circumstances, and when the anti-adhesive agent is used as an anti-adhesive suspension, the anti-adhesive suspension has good wettability with respect to the surface of the unvulcanized rubber. In addition, when the anti-adhesive agent suspension is dried, the anti-adhesive agent adheres uniformly to the surface of the unvulcanized rubber and exhibits excellent adhesion. It is an object of the present invention to provide an anti-vulcanized rubber anti-adhesive agent that exhibits good anti-adhesion performance even when used as an adhesive.

The inventors of the present invention have focused on the wettability of the adhesive suspension to the unvulcanized rubber surface and the adhesion of the adhesive, and found that these improvements lead to the provision of excellent adhesion performance. The present invention has been completed.
The antivulcanizing agent for unvulcanized rubber according to the present invention contains bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more based on the total mass of bentonite with respect to the total mass of the unvulcanized rubber. -90 mass%, an anionic surfactant (B), and a nonionic surfactant (C) represented by the following formula (1), wherein the mass of (B) / the mass of (C) The expressed mass ratio is 0.15 to 0.65.

(Wherein R represents an aliphatic hydrocarbon group having 8 to 18 carbon atoms, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average number of moles of AO added, and n represents 1 to 1) 8 and (AO) _n contains at least an oxyethylene group)
The method for producing an adhesion-treated unvulcanized rubber according to the present invention is characterized by including a step of adhering the adhesion agent for unvulcanized rubber to the surface of the unvulcanized rubber.

The anti-curing agent for unvulcanized rubber of the present invention has good wettability with respect to the surface of the unvulcanized rubber when the anti-sticking agent is used as an anti-sticking agent suspension. In addition, when the anti-adhesive agent suspension is dried, the anti-adhesive agent adheres uniformly to the surface of the unvulcanized rubber. For this reason, even when the suspension is used at a low concentration of the anti-sticking agent, it exhibits good anti-sticking performance.

Hereinafter, the present invention will be described in detail.
The unvulcanized rubber anti-adhesive agent of the present invention (in the present specification, sometimes simply referred to as an anti-adhesive agent), for example, adheres to the surface of the unvulcanized rubber formed into a sheet to form a film, This prevents the sheet-like unvulcanized rubber from adhering to each other during storage.
The anti-adhesive agent of the present invention comprises 50 to 90% by mass of bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more with respect to the total mass of the bentonite, and an anionic surfactant. A powder composition containing (B) and a specific nonionic surfactant (C), usually in the form of an anti-adhesive suspension in which the anti-adhesive is dispersed in water, and an unvulcanized rubber Applied to the surface of the.

[(A) component]
In this invention, the bentonite (A) which contains Na type montmorillonite 60 mass% or more with respect to the total mass of bentonite is used as (A) component. The said bentonite (A) is a component which bears the anti-adhesion property of an anti-adhesive agent, Comprising: It is more preferable that content of Na type montmorillonite in bentonite (A) is 90 mass% or more with respect to the total mass of bentonite. preferable. An anti-adhesive agent using bentonite having a Na-type montmorillonite content of less than 60% by mass with respect to the total mass of bentonite has insufficient adhesion to the surface of the unvulcanized rubber. Excellent anti-adhesion performance cannot be imparted. Bentonite (A) contains quartz, cristobalite, feldspar, carbonate minerals, etc. in addition to Na-type montmorillonite. Adhesion decreases when the total mass of these impurities exceeds 40% by mass with respect to the total mass of bentonite. To do.
The content of Na-type montmorillonite in bentonite (A) is a value measured by X-ray diffraction.

[Component (B)]
In the present invention, an anionic surfactant is used as the component (B).
The anionic surfactant (B) effectively adsorbs to the Na-type montmorillonite in the bentonite (A) when the anti-vulcanized rubber anti-adhesive agent of the present invention is used as an anti-adhesive suspension. The type montmorillonite is uniformly dispersed in the form of flakes in the anti-adhesive agent suspension, and the surface tension of the anti-adhesive agent suspension with respect to the surface of the unvulcanized rubber is reduced, whereby the anti-adhesive agent suspension It is surmised that it has the effect of improving the wettability with the surface of the unvulcanized rubber.
Specifically, as the component (B),
(1) Carboxylic acid type anionic surfactants such as higher fatty acid salts, alkyl ether carboxylates, polyoxyalkylene ether carboxylates, alkyl (or alkenyl) amide ether carboxylates, acylaminocarboxylates,
(2) Sulfate-type anionic surface activity such as higher alcohol sulfate, polyoxyalkylene higher alcohol sulfate, alkylphenyl ether sulfate, polyoxyalkylene alkylphenyl ether sulfate, glycerin fatty acid ester monosulfate Agent,
(3) sulfonic acid type anionic surfactants such as alkane sulfonate, α-olefin sulfonate, linear alkylbenzene sulfonate, α-sulfo fatty acid ester salt, dialkyl sulfosuccinate,
(4) Phosphate ester type anionic surfactants such as alkyl phosphate ester salts, polyoxyalkylene alkyl phosphate ester salts, polyoxyalkylene alkyl phenyl phosphate ester salts, glycerin fatty acid ester monophosphate ester salts, and the like.

The higher fatty acid means a fatty acid having 6 to 20 carbon atoms, and the higher alcohol means an alcohol having 6 to 20 carbon atoms.
The counter ion of the anionic surfactant is preferably an alkali metal such as sodium or potassium, or an alkanolamine such as monoethanolamine or diethanolamine. These may be used alone or in combination of two or more. That is, the salt of the anionic surfactant is preferably a salt with an alkali metal such as sodium or potassium, or a salt with an alkanolamine such as monoethanolamine or diethanolamine.
As the anionic surfactant, a dialkylsulfosuccinate is preferable, and a dioctylsulfosuccinate Na salt is more preferable because an anti-adhesive suspension excellent in wettability with the surface of the unvulcanized rubber can be obtained.

[Component (C)]
In the present invention, a nonionic surfactant represented by the formula (1) (that means a polyoxyalkylene alkyl ether) is used as the component (C). The nonionic surfactant of the formula (1), together with the anionic surfactant which is the component (B), reduces the surface tension of the anti-adhesive agent suspension relative to the surface of the unvulcanized rubber, It is presumed that the effect of effectively increasing the adhesion of the adhesion-preventing agent to the surface of the vulcanized rubber is exhibited.

In the formula, R represents an aliphatic hydrocarbon group having 8 to 18 carbon atoms. The aliphatic hydrocarbon group for R may be linear or branched. Moreover, either saturated or unsaturated may be sufficient. The carbon number of 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 is the average added mole number of AO.
n is preferably 1 to 8, and more preferably 1 to 5.
When n is less than 1, the surface activity decreases, and the dispersibility of component (A) decreases. When n is in the range of 1 to 8, the dispersibility of component (A) is improved, and adhesion is improved by giving sufficient viscoelasticity to the coating even when the hydrophobicity of the unvulcanized rubber surface is high. It is considered a thing. When n exceeds 8, the hydrophilicity becomes too high and lacks suitability.

The oxyalkylene group having 2 to 4 carbon atoms is a group formed by adding an alkylene oxide having 2 to 4 carbon atoms, and is formed by adding an oxyethylene group (EO) formed by adding ethylene oxide or propylene oxide. There are oxypropylene groups (PO) and oxybutylene groups (BO) formed by addition of butylene oxide, and (AO) _n contains at least an oxyethylene group. (AO) When _n contains an oxyethylene group (EO) and an oxypropylene group (PO) and / or an oxybutylene group (BO), these groups are randomly arranged even if they are arranged in a block shape. It may be arranged. Preferable (AO) _n consists of only an oxyethylene group (EO) from the viewpoint of excellent balance between hydrophilicity and hydrophobicity.

As such nonionic surfactant (C), the following are mentioned, for example.
A nonionic surfactant (hereinafter referred to as C13EO3) in which R in the formula (1) is a branched and saturated aliphatic hydrocarbon group having 13 carbon atoms, n is 3, and AO is EO. May be indicated.) As such a nonionic surfactant (C), there is “Leocor TD-30 (purity 100%)” manufactured by Lion Corporation.
-Nonion in which R in formula (1) is a branched and saturated aliphatic hydrocarbon group having 13 carbon atoms, n is 3, and 2 mol of EO and 1 mol of PO are added as AO Surfactant (hereinafter sometimes referred to as C13EO2 / PO1). As such a nonionic surfactant (C), there is “Finesurf TDP-0201R (100% purity)” manufactured by Aoki Oil & Fat Co., Ltd.
A nonionic surfactant (hereinafter referred to as C18EO5) in which R in the formula (1) is a linear and saturated aliphatic hydrocarbon group having 18 carbon atoms, n is 5, and AO is EO. May be written.) As such a nonionic surfactant (C), there is “Brownon SR-705 (purity 100%)” manufactured by Aoki Oil & Fat Co., Ltd.).
Among these, C13EO3 and C13EO2 / PO1 are more preferable.

[Optional ingredients]
In addition to the above-mentioned components (A) to (C), the anti-adhesive agent of the present invention may contain additives such as antifoaming agents, wettability aids, lubricants (sliding agents), and viscosity aids as necessary. May be included as an optional component.
There are no particular limitations on the antifoaming agent, but for example, oil-based antifoaming agents such as castor oil, sesame oil, linseed oil, animal and vegetable oils; isoamyl stearate, distearyl succinate, ethylene glycol distearate, butyl stearate, etc. Fatty acid ester antifoaming agents; alcohol defoaming agents such as polyoxyalkylene monohydric alcohol di-t-amylphenoxyethanol, 3-heptanol, 2-ethylhexanol; di-t-amylphenoxyethanol, 3-heptylcellosolve, Ether-based antifoaming agents such as nonyl cellosolve and 3-heptylcarbitol; phosphate ester-based antifoaming agents such as tributyl osphate and tris (butoxyethyl) phosphate; amine-based antifoaming agents such as diamylamine; Acylate polyami Amide-based defoaming agent and the like; mineral oils; silicone oil; and the like. One or more of the above antifoaming agents can be used.

Examples of the wettability aid include alcohols, and are not particularly limited. For example, methanol, ethanol, hexanol, glycerin, 1,3-butanediol, propylene glycol, dipropylene glycol, pentylene glycol, hexylene glycol, Examples thereof include polyethylene glycol, saltol, maltitol, sucrose, erythritol, xylitol and the like, and one or more kinds can be used.

Examples of the lubricant include metal soaps, and are not particularly limited. For example, magnesium laurate, calcium laurate, zinc laurate, magnesium myristate, calcium myristate, zinc myristate, magnesium palmitate, calcium palmitate, Particles consisting of zinc palmitate, magnesium stearate, calcium stearate, zinc stearate, aluminum trioctadecanoate, aluminum dioctadecanoate, aluminum monooctadecanoate, calcium octadecanoate, zinc octadecanoate, magnesium octadecanoate, barium octadecanoate, etc. 1 or more types can be used. The metal soaps described here are water-insoluble salts and generally do not correspond to anionic surfactants.
Further, as the lubricant, for example, carbonates such as calcium carbonate, magnesium carbonate, barium carbonate; silicates such as kaolin, aluminum silicate, calcium silicate, clay, talc, mica, sericite; calcium sulfate, sulfuric acid Sulfates such as barium; metal oxides such as silica, alumina, magnesium oxide, antimony trioxide, titanium oxide, white carbon and iron oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide and iron hydroxide; bengara Carbon black; inorganic powders such as graphite are also included, and one or more kinds can be used.

Examples of the viscosity auxiliary agent include water-soluble polymers and are not particularly limited. For example, proteins, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethylene oxide, Synthetic water-soluble polymers such as water-soluble urethane resin, water-soluble melamine resin, water-soluble epoxy resin, water-soluble butadiene resin and water-soluble phenol resin; xanthan gum, guar gum, welan gum, locust bean gum, diyutan gum, tamarind gum, tamarind Examples include natural water-soluble polymers such as seed gum, tragacanth gum, gum arabic, carrageenan, rhamzan gum, succinoglycan, tara gum, gellan gum, karaya gum, pectin, alginic acid derivatives, and cellulose ethers. These can be used 1 or more.
The anti-adhesive agent may contain water for the purpose of suppressing the powder flow. In that case, the content of water is, for example, about 2 to 3% by mass relative to the total mass of the adhesion-preventing agent.

[Anti-curing agent and non-vulcanized rubber with anti-deposition treatment]
The anti-adhesive agent of the present invention comprises 50 to 90% by mass of bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more with respect to the total mass of the bentonite, and an anionic surfactant. (B) and the nonionic surfactant (C) represented by Formula (1) are contained.
Since bentonite (A) is a component responsible for adhesion, the adhesion is reduced when the content in the adhesion is less than 50% by mass relative to the total mass of the adhesion. On the other hand, when the content in the anti-adhesive agent exceeds 90% by mass with respect to the total mass of the anti-adhesive agent, the contents of the component (B) and the component (C) are relatively reduced. As a result, the wettability and adhesion of the suspension of the anti-adhesive agent to the surface of the resin deteriorate, and as a result, sufficient anti-adhesive properties cannot be obtained. A more preferable content of bentonite (A) in the anti-adhesive agent is 60 to 80% by mass with respect to the total mass of the anti-adhesive agent.
In addition, some bentonite circulates in a state containing water, but in the present specification, when the content of bentonite (A) is referred to, the content is a value not including the amount of water.

The mass ratio (B) / (C) of the mass of the component (B) to the mass of the component (C) in the anti-adhesive agent is preferably 0.15 to 0.65. With such a mass ratio, when the anti-adhesive agent of the present invention is used as an anti-adhesive suspension, the anti-adhesive suspension exhibits good wettability with respect to the surface of the unvulcanized rubber. And when the anti-adhesive suspension is dehydrated and dried on the surface of the unvulcanized rubber in a high temperature state, the anti-adhesive suspension is removed from the surface of the unvulcanized rubber. And an excellent anti-adhesive that adheres uniformly to the surface. Thus, when both the wettability and adhesion between the anti-adhesive suspension and the unvulcanized rubber are excellent, even when the concentration of the anti-adhesive suspension is reduced, And good adhesion performance can be imparted. When the mass ratio is less than 0.15, the wettability between the anti-adhesive suspension and the unvulcanized rubber is insufficient due to the relatively small amount of the anionic surfactant as the component (B). Become. On the other hand, when it exceeds 0.65, due to the relatively small amount of the specific nonionic surfactant as the component (C), the adhesion of the anti-adhesive agent to the surface of the unvulcanized rubber becomes insufficient. . The mass ratio (B) / (C) is preferably 0.20 to 0.50.

The mass ratio ((B) + (C)) / (A) of the total mass of the component (B) and the component (C) to the mass of the component (A) in the anti-adhesive agent is preferably 0.05 or more, More preferably, it is 0.15 to 0.30. When the mass ratio is less than the above lower limit, the wettability between the surface of the anti-adhesive agent suspension and the unvulcanized rubber, the adhesion of the anti-adhesive agent to the surface of the unvulcanized rubber is insufficient, There is a tendency that it is impossible to impart good adhesion performance. On the other hand, even if the mass ratio ((B) + (C)) / (A) is increased, the above-mentioned wettability and adhesion are not lowered, but the amount of the surfactant is relatively increased. In addition, foaming troubles may occur during the preparation of the anti-sticking agent suspension or when the anti-sticking agent suspension is adhered to the unvulcanized rubber. Further, since the surfactant is expensive, it is not advantageous in terms of cost. From these points, the mass ratio ((B) + (C)) / (A) is preferably 0.30 or less.

The anti-adhesive agent of the present invention can be produced by mixing the components (A) to (C) and optional components blended as necessary. As an apparatus used for mixing, an apparatus having a configuration in which a stirring blade is provided in a container can be used. Specific examples include a powder mixer that can perform rocking stirring or stirring, such as a ribbon-type mixer and a vertical screw-type mixer. In addition, a super mixer (manufactured by Kawata Co., Ltd.), a high speed mixer (manufactured by Fukae Co., Ltd.), a new gram machine (manufactured by Seishin Enterprise Co., Ltd.), and an SV mixer (manufactured by Shinko Environmental Solution Co., Ltd.) Multifunctional powder mixers such as can also be used. Also, dry crushers such as jaw crusher, gyratory crusher, cone crusher, roll crusher, impact crusher, hammer crusher, rod mill, ball mill, vibration rod mill, vibration ball mill, disk type mill, jet mill, cyclone mill, etc. Good.
In addition, when using at least one liquid component among the components (A) to (C) and optional components, a spray device for spraying or spraying the liquid component on a mixture other than the liquid component, You may use a shower apparatus etc. together.

The method for producing an adhesion-treated unvulcanized rubber according to the present invention includes a step of adhering the above-mentioned adhesion preventing agent to the surface of the unvulcanized rubber. Even if the non-vulcanized rubber that has been subjected to the adhesion treatment manufactured in this way is stored by being stacked or folded, the unvulcanized rubber does not adhere to each other.
The adhesion process includes a suspension adhesion process in which an anti-adhesive suspension in which an anti-adhesive is dispersed in water is adhered to the surface of the unvulcanized rubber, and an anti-adhesive suspension on the surface of the unvulcanized rubber. A step having a drying step of drying the liquid and forming a film made of an anti-adhesive agent on the surface of the unvulcanized rubber is preferable. Such a process is sometimes called a wet method.

In the suspension adhering step, it is preferable to adhere the anti-adhesive agent suspension to the unvulcanized rubber at a high temperature of, for example, about 80 to 150 ° C. by heat when it is formed into a sheet or the like.

Specific methods of the suspension adhesion step include, for example, a method of spraying the anti-adhesive suspension on the unvulcanized rubber with a shower device, and a short method of unvulcanized rubber in the tank containing the anti-adhesive suspension. There is a dipping method in which the immersion is performed for a time. Moreover, the method of apply | coating anti-adhesive agent suspension to unvulcanized rubber using an application | coating apparatus may be employ | adopted, and these methods may be used together suitably.

As described above, the anti-adhesive agent of the present invention contains Na-type montmorillonite in an amount of 60% by mass or more with respect to the total mass of bentonite, and bentonite (A) having excellent adhesiveness with respect to the total mass of the anti-adhesive agent. In addition to containing 50 to 90% by mass, the anionic surfactant (B) and the nonionic surfactant (C) represented by the formula (1) are included. The mass ratio (B) / (C) of the content of the anionic surfactant (B) to the content of the nonionic surfactant (C) is preferably 0.15 to 0.65. Therefore, when the antiadhesive is used as an antiadhesive suspension, the concentration of the antiadhesive is as low as 1.0 to 1.5% by mass relative to the total mass of the antiadhesive suspension. It can be used at a low concentration, and even when used at the low concentration, it can form a uniform film composed of the anti-adhesive agent on the surface of the unvulcanized rubber, and has excellent anti-adhesion performance against the unvulcanized rubber. Give.

The reason why the anti-adhesive agent of the present invention has such an effect can be presumed as follows.
The anionic surfactant of the component (B) constituting the anti-adhesive agent is effectively adsorbed on Na-type montmorillonite in bentonite (A) when the anti-adhesive agent is used as an anti-adhesive suspension, It is considered that Na-type montmorillonite is uniformly dispersed in the form of flakes in the above-mentioned anti-adhesive suspension, and the surface tension of the above-mentioned anti-adhesive suspension with respect to the surface of the unvulcanized rubber is reduced. Therefore, the anti-sticking agent suspension prepared from the anti-sticking agent of the present invention containing the component (B) is not only excellent in wettability with the surface of the unvulcanized rubber, but also in a highly dispersed state of Na-type montmorillonite. It is considered that the surface of the unvulcanized rubber can be efficiently covered.

On the other hand, the nonionic surfactant of component (C) that constitutes the anti-adhesive agent acts together with the anionic surfactant as the component (B), and the surface of the anti-adhesive suspension with respect to the surface of the unvulcanized rubber. In addition to lowering the tension, the dispersion of the bentonite component (A) in the above-described anti-adhesive suspension is controlled, and the anti-adhesive suspension covering the surface of the unvulcanized rubber is dried and dehydrated. In the course of the process, it is presumed that the adhesion of the adhesion preventing agent to the unvulcanized rubber surface is effectively enhanced by increasing the viscoelasticity of the adhesion preventing agent suspension. For this reason, the anti-adhesive agent in the anti-adhesive suspension covering the surface of the unvulcanized rubber does not repel the surface of the unvulcanized rubber during the drying process after adhering to the surface. It is thought that it adheres and forms a uniform film.

Thus, in addition to containing bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more with respect to the total mass of bentonite as a component responsible for adhesion, the depositing agent of the present invention is as described above. An anionic surfactant (B) and a nonionic surfactant (C) that exhibit a specific action are contained in a specific ratio.
Therefore, when the anti-adhesive agent of the present invention is used as an anti-adhesive suspension, the anti-adhesive agent suspension exhibits good wettability with respect to the surface of the unvulcanized rubber, and When the adhesive suspension is dried, the anti-adhesive agent adheres to the surface of the unvulcanized rubber evenly and exhibits excellent adhesion. Therefore, even when the suspension is used with a low concentration of the anti-adhesive agent, Good adhesion performance can be imparted to unvulcanized rubber.

There are no particular restrictions on the type of rubber to which the adhesion-preventing agent of the present invention can be applied, as long as it is an unvulcanized rubber.
Examples of rubber types include natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), IIR (butyl rubber), EPDM (ethylene propylene rubber), and a mixture of these. The rubber which was made is mentioned. In addition, the unvulcanized rubber to which the adhesion-preventing agent is applied is a vulcanizing agent (sulfur etc.) and various additives generally used for rubber (anti-aging agent, vulcanization accelerator, carbon black, etc.). ) And the like.
One aspect of the present invention is that the bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more with respect to the total mass of bentonite is 50 to 90% by mass with respect to the total mass of the composition, B) and the nonionic surfactant (C) represented by the formula (1), and the mass ratio represented by the mass of the (B) / the mass of the (C) is 0.15 to Relates to the composition being 0.65.
Another aspect of the present invention is that the bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more based on the total mass of bentonite is 50 to 90% by mass based on the total mass of the composition; More preferably, an anionic surfactant (B) which is a dioctylsulfosuccinate Na salt; represented by the formula (1), wherein R in the formula (1) is a branched and saturated aliphatic group having 13 carbon atoms. A nonionic surfactant having a hydrocarbon group, n of 3 and AO of EO, represented by the formula (1), wherein R in the formula (1) is branched and saturated with 13 carbon atoms Type non-ionic surfactant having n type of 3 and 2 mol of EO and 1 mol of PO as AO, and the formula (1) R is straight and saturated with 18 carbon atoms At least one nonionic surfactant (C) selected from the group consisting of nonionic surfactants, wherein n is 5, and AO is EO, The present invention relates to a composition in which the mass ratio represented by the mass of B) / the mass of (C) is 0.15 to 0.65.
Another aspect of the present invention is any one of the above aspects, further comprising at least one additive selected from the group consisting of an antifoaming agent, a wettability aid, a lubricant (slipper), and a viscosity aid. Relates to one composition.
Yet another aspect of the present invention relates to the use of any one of the above aspects for the prevention of unvulcanized rubber.

Hereinafter, the present invention will be specifically described with reference to examples.
[Production example]
Bentonite (A-1) (“Kunipia-F” manufactured by Kunimine Kogyo Co., Ltd., Na-type montmorillonite content: 98.5% by mass (Kunipia F product) so that the Na-type montmorillonite content is as shown in Table 1. 6) Bentonite (A-2) to (A-6) with different contents of Na-type montmorillonite mixed with bentonite sub-mineral prepared by the following method. ) Was prepared as component (A).

(Method for preparing bentonite secondary mineral)
A 5% by mass aqueous dispersion of bentonite (“Kunigel V-1” manufactured by Kunimine Kogyo Co., Ltd.) was prepared and allowed to stand for one day to precipitate a solid content. Next, the liquid in which the solid content was precipitated was centrifuged (rotation speed: about 5000 rpm, 30 minutes), and the precipitate was collected.
Next, a 5% by mass aqueous dispersion of this precipitate is prepared, and the series of operations of solid content precipitation, centrifugation, and precipitation recovery by the same method as described above is repeated twice more, and the resulting precipitate is decompressed. After drying, it was pulverized in an agate mortar. The powder thus obtained was designated as “bentonite secondary mineral”.
As a result of analyzing the bentonite minor mineral by X-ray diffraction, the bentonite minor mineral mainly contains quartz, cristobalite, feldspar, carbonate mineral, etc., and diffraction derived from Na-type montmorillonite appearing near 2θ = 7 °. It was confirmed that the content (residual amount) of Na-type montmorillonite determined from the peak intensity was 1% by mass or less of the detection limit.
The analysis conditions for X-ray diffraction when the Na-type montmorillonite content (residual amount) is quantified are as follows.

X-ray diffraction analysis conditions / measurement device: X'Pert PRO MRD (manufactured by PANalytical)
・ Target: Cu
・ Tube voltage: 45kV
・ Tube current: 40 mA
・ Scan axis: Goniometer ・ Scan range: 5 ° -60 °
・ Step size: 0.03 °
・ Step time: 12.7 seconds ・ Divergent slit: 1/2 °
・ Scatter slit: 1 °
・ Reception slit: None

In addition, “Kunigel V-1” used as a raw material for bentonite sub-minerals is described in the literature [Analysis of Bentonite Mineral Composition (Journal of the Atomic Energy Society of Japan) 1055-1058], the smectite content is 46 to 49% by mass. The smectite here is montmorillonite.

[Examples 1 to 18, Comparative Examples 1 to 9]
The components (A) to (C) and calcium stearate (optional component: manufactured by NOF Corporation, calcium stearate (purity 100%)) as a lubricant are kneaded at a mass ratio shown in Tables 2 to 4. In each case, an anti-adhesive agent comprising a uniform powder was prepared. And each obtained anti-adhesive was added to tap water, stirring, and prepared the anti-adhesive suspension whose density | concentration of an anti-adhesive is 1 mass% with respect to the total mass of an anti-adhesive suspension. .
The following evaluation was performed using the obtained anti-adhesive agent suspension (concentration 1% by mass) of each example.

The components (B) and (C) used in each example are as follows.
(B-1): Dioctyl sulfosuccinate Na salt (manufactured by Nippon Cytec Industries, Ltd., “Aerosol GPG (purity 70%)”)
(B-2): Alkylbenzenesulfonic acid sodium salt whose alkyl group has 12 to 20 carbon atoms (“Liporan PB (purity 95%)” manufactured by Lion Corporation)
(B-3): Na stearate (manufactured by Dainichi Chemical Co., Ltd., “Die Wax NA (purity 100%))

(C-1): “Leocor TD-30 (100% purity)” manufactured by Lion Corporation
(C-2): “Finesurf TDP-0201R (purity 100%)” manufactured by Aoki Oil & Fat Co., Ltd.
(C-3): “Brownon SR-705 (100% purity)” manufactured by Aoki Oil & Fat Co., Ltd.
(C-4): Comparative product, wherein in formula (1), R is a linear, saturated, n = 9, AO = EO nonionic surfactant having 12 carbon atoms, manufactured by Lion Corporation, “ Leox CC-90 (purity 98%) "

<Evaluation>
For various evaluations, the following unvulcanized NR / BR rubber was used as a rubber for evaluation.
(Unvulcanized NR / BR rubber)
For a total of 100 parts by mass of 70 parts by mass of NR (RSS # 3) and 30 parts by mass of BR (manufactured by JSR Co., Ltd., “BR-01”), White Carbon (Tosoh Silica Co., Ltd., “Nip Seal VN -3 ") 10 parts by mass, ISAF black (manufactured by Tokai Carbon Co., Ltd.," Seast 6 "), 30 parts by mass, JSRARAMA (process oil) (Nihon Sun Sekiyu Co., Ltd.," Aroma 790 ") 15 parts by mass Parts, 3 parts by weight of zinc white (Hakusuitec Co., Ltd., 2 types of zinc white), 1 part by weight of stearic acid (manufactured by NOF Corporation, cocoon), 6PPD (manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.) , Anti-aging agent “NOCRACK 6C”, 1 part by mass of N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine), CBS (manufactured by Ouchi Shinsei Chemical Co., Ltd., vulcanization accelerator) "Noxeller CZ-G", N- Unvulcanized NR / BR rubber containing 1 part by weight of cyclohexyl-2-benzothiazolylsulfenamide) and 1.5 parts by weight of sulfur (manufactured by Tsurumi Chemical Co., Ltd.) (total of 162.5 parts by weight).

(1) Evaluation of wettability The unvulcanized rubber (unvulcanized NR / BR rubber) is kneaded with an open roll at a temperature of 80 to 120 ° C. to obtain a rubber sheet (thickness: 5 to 8 mm, 60 cm × 15 cm). The rubber sheet immediately after kneading was immersed in 1 L of an anti-adhesive suspension (temperature 40 ° C.) obtained in each example for about 1 second. Thereafter, the rubber sheet was quickly pulled up vertically and allowed to stand at room temperature. After about 3 seconds, the surface of the rubber sheet was photographed. By observing the obtained photograph, the ratio (%) of the area of the wetted part when the surface area of the rubber sheet was set to 100% was determined, and the wettability was judged from the values in the following five stages 1-5. . The larger the area of the wet part, the better the wettability. The results are shown in Tables 2-4.
1%
2: 0 and less than 50% 3: 50% or more and less than 90% 4: 90% or more and less than 100% (pass)
5: 100% (pass)

(2) Evaluation of adhesiveness Immediately after evaluating the wettability as described in (1) above (that is, immediately after taking a picture of the surface of the rubber sheet), it is allowed to stand still at room temperature, and again after 90 seconds, The surface of the rubber sheet was photographed. By observing the obtained photograph, the ratio (%) of the area (coating area) of the portion covered with the dry coating of the anti-adhesive agent when the surface area of the rubber sheet is 100%, and the homogeneity of the coating ( From the two sides (which are covered with a uniform film thickness), the following 5 grades of 1 to 5 were made. The results are shown in the table.
1: 0% coating area
2: The coating area exceeds 0 and less than 40% 3: The coating area is 40% or more and less than 70% 4: The coating area is 70% or more and less than 100%, and the coating is not vertically striped or madrid It is a film (pass).
5: The coating area is 100%, and the coating is a homogeneous coating that is not vertically striped or madrid (pass).

As described above, immediately after pulling out the rubber, which has been kneaded with an open roll at 80 to 120 ° C. and whose surface is in a high temperature state, the rubber is immersed in the anti-adhesive agent suspension for a very short time (about 1 second). In addition, even if moisture rapidly evaporates from the attached anti-adhesive suspension, the anti-adhesive agent can be applied in a uniform thin film state with no unevenness such as vertical stripes and madras. The state that can remain on the rubber surface was regarded as a passing score.

(3) Evaluation of adhesion prevention performance Unvulcanized rubber (unvulcanized NR / BR rubber) is kneaded with an open roll at a temperature of 80 to 120 ° C. to give a rubber sheet (thickness: 5 to 8 mm, 60 cm × 15 cm) The rubber sheet immediately after being kneaded was immersed in 1 L of the anti-adhesive suspension (temperature 40 ° C.) obtained in each example for about 1 second. Thereafter, the rubber sheet was quickly pulled up vertically, allowed to stand in a vertical state at room temperature, and naturally dried.
Thereafter, the rubber sheet was cut into 6 cm × 15 cm, and the two sheets were laminated to form a laminated state. A load of 1 t / m ² was applied to the test piece in the laminated state in the vertical direction from one surface, and 60 It was left at 12 ° C. for 12 hours.
Thereafter, the test piece was returned to room temperature, a 180 ° peel test was performed using a tensile tester [AGS-500D type, SHIMADZU], and peel resistance (N / cm) was measured at a pulling speed of 300 mm / min. The measured peel resistance values are listed in Tables 2-4.

When the peel resistance is 2.0 N / cm or less, the rubber sheet can be peeled off without a large load, and it can be judged that the adhesion prevention performance is good. When the peel resistance is more than 2.0 N / cm, it can be determined that the load when peeling the rubber sheet is large and the adhesion prevention performance is poor. Furthermore, when the peeling resistance is more than 3.0 N / cm, the rubber sheet is in close contact, and it can be judged that peeling at a normal work site is difficult.

The blending amount (mass ratio%) of each component in the table is a value calculated in terms of pure content.

As shown in Tables 2 to 3, each of the anti-sticking agent suspensions obtained in Examples 1 to 18 has both wettability and adhesion to the surface of the unvulcanized rubber in a high temperature state. It was a passing score of 4 points or more and was excellent. Specifically, according to each of the anti-sticking agent suspensions obtained in Examples 1 to 18, the rubber having the surface heated at 80 to 120 ° C. and having a high temperature is removed for a very short time (about 1 sec) shows excellent wettability immediately after pulling up, and even if moisture rapidly evaporates from the adhered suspension of adhesion, unevenness such as vertical stripes and madras A uniform thin film of the anti-adhesive agent dried film having no area could be formed on the rubber surface at a high area ratio. The unvulcanized rubber treated with the anti-adhesive agent suspensions of Examples 1 to 18 having excellent wettability and adhesion as described above has a peel resistance even after being overlaid and loaded. All of them were as low as 2 N / cm or less, and high adhesion performance was imparted.
From the above, it has been clarified that having both good wettability and adhesion leads to the provision of excellent anti-adhesion performance.

On the other hand, as shown in Table 4, each of the anti-sticking agent suspensions obtained in Comparative Examples 1 to 9 is not good because at least one of wettability and adhesion is 3 points or less. Therefore, the result was that the adhesion preventing performance was not good. For example, in Comparative Examples 1 and 2 using bentonite (A) having a low Na-type montmorillonite content, wettability and adhesion were poor. In Comparative Example 3, since the amount of bentonite (A) is small, the wettability is good but the adhesion is poor. In Comparative Example 4, the amount of bentonite (A) is excessive, and the anionic surfactant (B) and the nonionic surfactant Since there was little (C), wettability was bad and adhesiveness was also bad. Further, in Comparative Example 5 using a nonionic surfactant having a large average added mole number of oxyalkylene groups, the nonionic surfactant (C) has high hydrophilicity and insufficient wettability and adhesion. It was. In Comparative Example 6 containing no nonionic surfactant (C), the wettability was excellent, but the adhesion was poor. In Comparative Example 7 not containing the anionic surfactant (B), wettability and adhesion were extremely poor, and therefore, in the evaluation of the anti-adhesion performance, the two rubber sheets constituting the test piece were in close contact with each other. In the 180 ° peel test under the above conditions, the test piece could not be peeled off, and the test piece was also broken. Further, Comparative Example 8 having a small (B) / (C) had poor wettability, and Comparative Example 9 having a large (B) / (C) had particularly poor adhesion.
In addition, regarding the adhesion, in Comparative Example 3 and Comparative Example 6, the ratio of the area of the portion covered with the dry film is high, but vertical striped unevenness is observed. In Comparative Example 4, the dry film is In addition to the low area ratio of the covered part, spotted irregularities were observed.
As described above, the suspensions of Examples 1 to 18 were prepared by using bentonite (A) containing 60% by mass or more of Na-type montmorillonite, an anionic surfactant (B), and a specific nonion as the deposition inhibitor. A surfactant (C) and a mass ratio represented by (B) / (C) of 0.15 to 0.65 is used. It exhibits good wettability and exhibits excellent adhesion that adheres to the surface of the unvulcanized rubber evenly when dried. Therefore, even if the concentration of the anti-sticking agent in the suspension is as low as 1% by mass, It was clear that good adhesion performance could be imparted to the vulcanized rubber.

In the above embodiment, NR / BR rubber is used as the rubber of the unvulcanized rubber. However, even when rubber such as general NR, SBR, BR, IIR, EPDM is used, the above embodiment and Results similar to those of the comparative example are obtained.

The anti-curing agent for unvulcanized rubber according to the present invention, when the anti-sticking agent is used as an anti-sticking agent suspension, the unvulcanized rubber is used even if the anti-sticking agent concentration of the suspension is lowered. Excellent adhesion performance.

Claims

Bentonite (A) containing Na-type montmorillonite in an amount of 60% by mass or more with respect to the total mass of bentonite is 50 to 90% by mass with respect to the total mass of the unvulcanized rubber protective agent, and an anionic surfactant (B) And a nonionic surfactant (C) represented by the following formula (1), and the mass ratio represented by the mass of (B) / the mass of (C) is 0.15 to 0.001. An adhesion preventive agent for unvulcanized rubber, which is 65.

(Wherein R represents an aliphatic hydrocarbon group having 8 to 18 carbon atoms, AO represents an oxyalkylene group having 2 to 4 carbon atoms, n represents an average number of moles of AO added, and n represents 1 to 1) 8 and (AO) n contains at least an oxyethylene group)
A process for producing an adhesion-treated unvulcanized rubber, comprising the step of adhering the adhesion preventive for unvulcanized rubber according to claim 1 to the surface of the unvulcanized rubber.