JP6408326B2 - Non-vulcanized rubber anti-adhesive and its use - Google Patents

Description

  The present invention relates to an unvulcanized rubber anti-adhesive agent and use thereof.

In the production and processing process of rubber products, unvulcanized rubber may be stacked and stored until it is transferred to the next molding or vulcanization process. In this case, adhesion prevention is performed to prevent rubber adhesion. An agent (anti-adhesive) is used.
Conventionally, inorganic particles such as talc, mica, calcium carbonate, magnesium carbonate, bentonite and the like have been used as this anti-adhesive agent because of its excellent anti-adhesive properties. As the method of use, a so-called dry method such as a method of spraying rubber with powder or a method of passing through powder; a method of suspending the powder of inorganic particles in water and spraying the suspension; And so-called wet methods such as a method of spraying on rubber and a method of immersing in a suspension. The purpose of using water in the wet method is to improve the workability and also to cool the rubber. Further, in hollow and thin cylindrical molding of a tire tube or the like using an extruder, the inner surface of the cylinder is prevented from adhering by extrusion molding while blowing air mixed with an anti-adhesive agent into the tube.

When using an anti-corrosion agent using such inorganic particles, after being attached to the rubber surface, the powder falls off before moving to the next molding or vulcanization process, and dust is generated. There's a problem. In addition, a strong lump of inorganic particles continues to exist without breaking down, which may have a great influence on the physical properties of the final rubber product. As a method for suppressing contamination of the work environment due to dust generation, there is a means to install a local exhaust system, but it requires equipment investment costs and is not a fundamental solution.
As countermeasures, various anti-adhesive agents have been developed that reduce the use of inorganic substances and mainly consist of organic substances. However, the anti-adhesive agents that solve the above problems and sufficiently satisfy each characteristic required for the anti-adhesive agent. Never before.

Patent Document 1 discloses a method in which a composition obtained by dispersing a fatty acid soap having a limited number of carbon atoms and metal ions and a specific surfactant in water is applied to a rubber surface to prevent adhesion. This method is characterized in that inorganic powder is not used, and dust scattering and formation of strong lumps after the deposition treatment can be reduced. However, in order to exhibit sufficient anti-adhesion performance, it is necessary to use it at a high concentration, and in that case, there arises a problem that the physical properties of the vulcanized rubber are greatly reduced. Moreover, the sliding frictional force of the rubber surface to which the anti-adhesive composition is applied is large, and there is a concern that the rubber is difficult to slide at the work site and the workability is lowered.
Patent Document 2 discloses an anti-wear composition comprising a water-soluble polymer having film-forming properties and an anionic surfactant or a nonionic surfactant. This anti-wearing composition is also characterized by not using inorganic powder, and dust scattering and formation of a strong lump after the anti-sticking treatment can be reduced. However, in order to exert sufficient anti-adhesion performance, it is necessary to use it at a high concentration, in which case the water retention of the water-soluble polymer becomes remarkably high, and after the application of the anti-adhesive composition The drying process takes time and deteriorates productivity.
As described above, Patent Documents 1 and 2 show anti-adhesives mainly composed of organic substances, but no one that exhibits anti-adhesion performance at a low concentration has been proposed so far.

JP-A 49-47440 JP-A-62-32127

  In view of these conventional problems, the present invention provides an unvulcanized rubber anti-adhesive agent that exhibits excellent wettability and adhesion to unvulcanized rubber even at low concentrations and exhibits good anti-adhesion performance. An object of the present invention is to provide a method for producing a non-vulcanized rubber which has been subjected to an adhesion treatment performed using a vulcanized rubber adhesion preventing agent.

As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by an adhesion-preventing agent containing cellulose having a specific structure, and has reached the present invention.
That is, the non-vulcanized rubber anti-adhesive agent of the present invention is an anti-vulcanized rubber anti-adhesive composition containing hydroxyalkyl methyl cellulose, and the hydroxyalkyl methyl cellulose has a methoxyl group substitution degree of 0.5-2. The hydroxyalkyl group cellulose has an hydroxyalkyl group-substituted mole number of 0.025 to 0.5, and is an anti-vulcanized rubber composition for anti-vulcanized rubber.

It is preferable to further contain a water-soluble aldehyde.
The hydroxyalkylmethylcellulose preferably contains at least one selected from formaldehyde, acetaldehyde, propionaldehyde, glyoxal and succinaldehyde.
The viscosity of a 2% aqueous solution of the hydroxyalkyl methylcellulose is preferably 5 × 10 ¹ to 1 × 10 ⁷ mPa · s.
It is preferable that an inorganic powder and / or a surfactant is further contained.
The inorganic powder is at least one selected from bentonite, mica, talc, kaolin, amorphous silica, and calcium carbonate, and the surfactant is at least one selected from an anionic surfactant and a nonionic surfactant. A seed is preferred.

The manufacturing method of the non-vulcanized rubber subjected to the adhesion treatment according to the present application includes a treatment step of adhering the above-mentioned adhesion preventing composition for unvulcanized rubber to the surface of the molded unvulcanized rubber.
The rubber product of the present application is obtained by the above-described method for producing an adhesion-treated unvulcanized rubber.

The anti-vulcanized rubber adhesion-preventing agent of the present invention is excellent in wettability and adhesion to unvulcanized rubber even at low concentrations, and exhibits good adhesion performance.
Further, in the production method of the non-vulcanized rubber subjected to the adhesion treatment of the present invention, the use of the adhesion preventive agent for the unvulcanized rubber according to the present invention, there is little contamination of the rubber product at the adhesion treatment work place, Since it has excellent wettability and adhesion to unvulcanized rubber and exhibits good adhesion prevention performance, unvulcanized rubber can be produced more efficiently than before.

[Anti-curing agent for unvulcanized rubber]
The adhesion preventive agent for unvulcanized rubber of the present invention is an adhesion preventive agent containing hydroxyalkyl methylcellulose having a specific structure. Hereinafter, the following components will be described in detail.

Hydroxyalkyl methylcellulose is a component that forms a film on the surface of the unvulcanized rubber and prevents adhesion between the unvulcanized rubbers. The chemical properties of hydroxyalkyl methylcellulose are the average number of hydroxyl groups substituted with methoxyl groups per glucose ring of cellulose (substitution degree) and the average number of moles of hydroxyalkyl groups added per glucose ring of cellulose (number of substituted moles). Depends on the number. If the substitution degree of the methoxyl group of hydroxyalkylmethylcellulose is too small or too large, the solubility of hydroxyalkylmethylcellulose in water will be poor, and the coating properties on the unvulcanized rubber surface will also be reduced. The number of moles of substitution of the hydroxyalkyl group of the hydroxyalkylmethylcellulose affects the surface tension of the aqueous solution in which the hydroxyalkylmethylcellulose is dissolved. When the number of substituted moles is small, the surface tension is high, the wettability to the unvulcanized rubber surface is deteriorated, and the coating property is also lowered. On the other hand, when the number of substituted moles is too large, the wettability to the unvulcanized rubber surface is too good, dripping occurs, and uniform adhesion may be hindered.
As described above, it is desirable that the substitution degree of the methoxyl group and the number of substituted moles of the hydroxyalkyl group in the hydroxyalkylmethyl cellulose are selected within an appropriate range. The substitution degree of the methoxyl group is 0.5 to 2.5, preferably 0.75 to 2.25, more preferably 1.0 to 2.0, from the viewpoint of excellent water solubility. The number of moles of substitution of the hydroxyalkyl group is from 0.025 to 0.5 mole, preferably from 0.05 to 0.475 mole, more preferably from the viewpoint of excellent wettability and adhesion. 075 to 0.45 mol.

Since hydroxyalkyl methylcellulose generally has a molecular weight distribution, it is controlled by the viscosity of its aqueous solution. The viscosity of a 2% aqueous solution of hydroxyalkylmethylcellulose is preferably 5 × 10 ¹ to 1 × 10 ⁷ mPa · s, more preferably 5 × 10 ^{2 to} 9 × 10 from the viewpoint of excellent film forming ability and film strength. ⁶ mPa · s, more preferably 5 × 10 ³ to 8 × 10 ⁶ mPa · s, and particularly preferably 5 × 10 ^{4 to} 7 × 10 ⁶ mPa · s. In the present invention, the viscosity is measured at 20 ° C. using a Brookfield viscometer.
When the viscosity of a 2% aqueous solution of hydroxyalkylmethylcellulose is less than 5 × 10 ¹ mPa · s, the thickening effect of hydroxyalkylmethylcellulose is small, the film forming ability and the film strength are not excellent, and the adhesion prevention performance may be deteriorated. is there. On the other hand, if the viscosity of a 2% aqueous solution of hydroxyalkylmethylcellulose is more than 1 × 10 ⁷ mPa · s, the thickening effect of hydroxyalkylmethylcellulose is too great, and the handling of the unvulcanized rubber anti-adhesive agent becomes poor. In addition, when the deposition treatment is performed by a wet method, the water retention property may become too high and the drying property may be lowered.

Further, when the viscosity of a 2% aqueous solution of hydroxyalkylmethylcellulose satisfies the range of 5 × 10 ¹ to 1 × 10 ⁷ mPa · s, the thickening effect of hydroxyalkylmethylcellulose is moderate, handling is good, and unvulcanized rubber In the case of using an anti-adhesive agent for an anti-adhesion treatment by a wet method, water retention is moderate and drying is enhanced, which is preferable.

  The hydroxyalkylmethylcellulose is not particularly limited, and examples thereof include hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, and hydroxybutylmethylcellulose. These hydroxyalkyl methylcelluloses may be used alone or in combination of two or more. In the present invention, various hydroxyalkylmethylcelluloses can be selected, but hydroxypropylmethylcellulose is preferable because of its excellent coating performance.

When the anti-adhesive agent for unvulcanized rubber of the present invention further contains a water-soluble aldehyde, the anti-adhesion property is improved, which is preferable.
The reason why the adhesion resistance is improved by further containing a water-soluble aldehyde is that the hydroxyl group of the hydroxyalkylmethylcellulose is made hydrophobic by being sealed by a hemiacetal bond with the water-soluble aldehyde. It is presumed that this part is adsorbed to the rubber.
When a water-soluble aldehyde is contained in an anti-adhesive agent by a method in which an aqueous solution of a water-soluble aldehyde is heated to 60 to 80 ° C. and added to the hydroxyalkylmethylcellulose by spraying or the like and then subjected to aging treatment at 30 to 50 ° C. for several hours, This is preferable because of efficient progress. Thus, the hydroxyalkyl methylcellulose to which water-soluble aldehyde has been added is available as a commercial product.
In addition, the water-soluble aldehyde as used herein means one having a solubility of 0.1 g / L (25 ° C.) or more.

The water-soluble aldehyde is not particularly limited, and examples thereof include saturated monoaldehydes such as formaldehyde, acetaldehyde and propionaldehyde, and dialdehydes such as glyoxal and succinaldehyde.
The content of the water-soluble aldehyde is preferably 0.01 to 5% by weight and more preferably 0.5 to 4.5% by weight with respect to 100% by weight of the hydroxyalkylmethylcellulose. When the added amount is less than 0.01% by weight, dissolution starts immediately when dispersed in water, and it may become mamaco when left for a very short time. If the amount added exceeds 5% by weight, dissolution may not easily proceed after dispersion in water.

In addition to the components described above, the unvulcanized rubber adhesion-preventing agent of the present invention may further contain the following components.
(Surfactant)
The surfactant is a component that assists “wetting” with respect to the unvulcanized rubber. By including the surfactant in the anti-vulcanizing rubber composition of the present invention, the hydroxyalkyl cellulose can be more uniformly coated on the surface of the unvulcanized rubber.
The surfactant used in the present invention is not particularly limited as long as it is selected from nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like. Or 2 or more types may be included.

  Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene cetyl ether and polyoxyethylene lauryl ether; polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Polyoxyalkylene fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monooleate; polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate; polyoxyalkylene alkyl Amine; Fatty acid alkanolamide; Polyoxyalkylene fatty acid amide; Polyoxyalkylene hydrogenated castor oil; Polyoxy Ruki Ren sorbitol fatty acid esters; polyglycerol fatty acid esters, alkyl glycerol ether; polyoxyalkylene cholesteryl ether; alkylpolyglucosides; sucrose fatty acid esters; polyoxyethylene over oxypropylene block polymers and the like.

  Examples of the anionic surfactant include fatty acid salts such as sodium oleate, potassium palmitate and triethanolamine; alkyl sulfate esters such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium stearyl sulfate and sodium cetyl sulfate; Polyoxyalkylene alkyl ether acetates such as sodium oxyethylene tridecyl ether acetate; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; polyoxyalkylene alkyl ether sulfates; long-chain sulfosuccinates such as 2-ethylhexylsulfosuccinate Na N-acyl sarcosine salts such as oleoyl sarcosine Na and lauroyl sarcosine Na; stearoyl methyl taurine Na, lauroyl methyl taurine Na, Higher fatty acid amide sulfonates such as stoylmethyl taurine Na and palmitoyl methyl taurine Na; alkyl phosphates such as sodium monostearyl phosphate; polyoxyethylene oleyl ether sodium phosphate, polyoxyethylene stearyl ether sodium phosphate Polyoxyalkylene alkyl ether phosphate ester salts; long-chain N-acyl glutamates such as sodium monosodium N-lauroyl glutamate and disodium N-stearoyl-L-glutamate.

Examples of the cationic surfactant include alkyltrimethylammonium salts such as stearyltrimethylammonium chloride, lauryltrimethylammonium chloride, and cetyltrimethylammonium bromide; dialkyldimethylammonium salts; trialkylmethylammonium salts and alkylamine salts.
Examples of amphoteric surfactants include 2-undecyl-N, N- (hydroxyethylcarboxymethyl) -2-imidazoline sodium, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, and the like. Imidazoline-based amphoteric surfactants; betaine-based amphoteric surfactants such as 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine, lauryldimethylaminoacetic acid betaine, coconut oil fatty acid amidopropyl betaine; and N-laurylglycine Amino acid type amphoteric surfactants such as N-lauryl β-alanine and N-stearyl β-alanine.

(Inorganic powder)
The inorganic powder is a component that adheres to the surface of the unvulcanized rubber, prevents adhesion between the unvulcanized rubber, and reduces friction between the unvulcanized rubber.
Examples of inorganic powders include carbonates such as calcium carbonate, magnesium carbonate, and barium carbonate; silicates such as bentonite, kaolin, aluminum silicate, calcium silicate, clay, talc, mica, and sericite; calcium sulfate, Sulfates such as barium sulfate; Metal oxides such as amorphous silica, alumina, magnesium oxide, antimony trioxide, titanium oxide, white carbon, and iron oxide; Metal water such as aluminum hydroxide, magnesium hydroxide, and iron hydroxide Oxide, bengara, carbon black, graphite, etc.

(Metal soap)
Like the inorganic powder, the metal soap is a component that adheres to the surface of the unvulcanized rubber and prevents adhesion between the unvulcanized rubbers or reduces friction between the unvulcanized rubbers.
Examples of the metal soap include magnesium laurate, calcium laurate, zinc laurate, magnesium myristate, calcium myristate, zinc myristate, magnesium palmitate, calcium palmitate, zinc palmitate, magnesium stearate, calcium stearate, stearin Examples include particles composed of zinc acid, aluminum trioctadecanoate, aluminum dioctadecanoate, aluminum monooctadecanoate, calcium octadecanoate, zinc octadecanoate, magnesium octadecanoate, barium octadecanoate, etc. May be.

(Polyhydric alcohol)
The polyhydric alcohol is a component that adheres to the surface of the unvulcanized rubber, imparts lubricity between the unvulcanized rubber, and reduces friction between the unvulcanized rubber.
The polyhydric alcohol is not particularly limited. For example, glycerin, 1,3-butanediol, propylene glycol, dipropylene glycol, pentylene glycol, neopentyl glycol, hexylene glycol, polyethylene glycol, erythritol, pentaerythritol, di Examples include pentaerythritol, trimethylolethane, trimethylolpropane, ditrimethylolpropane, xylitol, sorbitol, mannitol, maltitol, maltotriose, glucose, sucrose, fructose, maltose, etc. Also good.

(Defoamer)
Examples of antifoaming agents include silicone-based antifoaming agents such as polymethylsiloxane and polyether-modified silicone; oil-based antifoaming agents such as castor oil, sesame oil, linseed oil, and animal and vegetable oils; stearic acid, oleic acid, and palmitic acid Fatty acid-based antifoaming agents such as isoamyl stearate, distearyl succinate, ethylene glycol distearate, and butyl stearate; polyoxyalkylene monohydric alcohol di-t-amylphenoxyethanol, 3 -Alcohol-based antifoaming agents such as heptanol and 2-ethylhexanol; Ether-based antifoaming agents such as di-t-amylphenoxyethanol 3-heptylcellosolvonylcellosolve 3-heptylcarbitol; Etc. Acid ester-based antifoaming agents; amine-based antifoaming agents such as diamylamine; amide-based antifoaming agents such as polyalkylene amide and acylate polyamine; sulfate-based antifoaming agents such as sodium lauryl sulfate; polyoxyalkylene-based antifoaming agents Agents; mineral oils and the like.

(Preservative)
Examples of the preservative include thiazoles such as thiazole and 2-mercaptothiazole; thiocyanates such as methylene bisthiocyanate and ammonium thiocyanate; and sulfimides such as o-benzoixsulfimide and phenylmercuric-o-benzoixsulfimide. Alkyldialkylthiocarbamates such as methyldimethylthiocarbamate and ethyldiethyldithiocarbamate; thyllium sulfides such as tetramethyltyranium sulfide and tetraethyltyranium sulfide; Dithiocarbamates such as ferric diethyldithiocarbamate and lead dimethyldithiocarbamate; o-toluenesulfonami Sulfamides such as benzenesulfonanilide; aminosulfonic acids such as 1-aminonaphthyl-4-sulfonic acid and 1-amino-2-naphthol-4-sulfonic acid; phenols such as pentachlorophenol and o-phenylphenol; These alkali metal salts; quinone chlorides such as tetrachloro-p-benzoquinone and 2,3-dichloro-1,4-naphthoquinone; nitro group-containing compounds such as dinitrocaprylphenylcrotonate and dinitro-o-cresol; Triazines such as 1,3,5-trihydroxyethylhexahydro-1,3,5-triazine, 1,3,5-triethylhexahydro-1,3,5-triazine; phenyl mercuric phthalate, o-hydroxy Organomercuration of phenylmercuric chloride, etc. Things; p-aminoazobenzene, amines such as diphenylamine; amides such as Shin'namuanirido; 1,3-diiodo-2-propanol and iodine-containing compounds, and the like.
(water)
The water may be any of tap water, ion-exchanged water, distilled water, etc., and is not particularly limited, but ion-exchanged water or distilled water is preferred. Further, from the viewpoint of water hardness, it is preferable that water is soft water from the viewpoint of quality control.

From the viewpoint of easily exerting the effect of the present application, the weight ratio of hydroxyalkyl methylcellulose in the nonvolatile content of the antiadhesive composition is preferably 2.5 to 100% by weight, more preferably 5.0 to 99.0% by weight. 7.5 to 98.0 wt% is more preferable, 10 to 97.0 wt% is particularly preferable, and 12.5 to 96.0 wt% is most preferable.
When the surfactant composition contains a surfactant or an inorganic powder, the weight ratio of the surfactant or the inorganic powder in the deposit composition is 0 from the viewpoint of easily exerting the effect of the present application. 0.1 to 97.5% by weight is preferable, 0.1 to 95% by weight is more preferable, 0.1 to 92.5% by weight is further preferable, 0.1 to 90% by weight is particularly preferable, and 0.2 to 87.5% by weight is most preferred.

(Manufacturing method of non-vulcanized rubber anti-corrosion agent)
About the manufacturing method of the adhesion preventive agent for unvulcanized rubber of this invention, if the process of mixing a hydroxyalkylmethylcellulose and another component etc. is included, there will be no limitation in particular about a mixing order, mixing equipment to be used, etc. The unvulcanized rubber adhesion-preventing agent can be produced, for example, by sequentially adding and mixing each component into a powder mixer such as a ribbon mixer.

(Method for producing non-vulcanized rubber subjected to adhesion treatment)
The method for producing an adhesion-treated unvulcanized rubber according to the present invention includes a treatment step of adhering the above-mentioned composition for an unvulcanized rubber to the surface of the unvulcanized rubber. Here, the unvulcanized rubber may be formed and processed.
In the treatment step, a wet method, that is, a method using a dispersion liquid in which water is blended as an anti-adhesive composition for unvulcanized rubber is preferable.
In the case where the treatment process is performed by a wet method, a method of spraying an unvulcanized rubber anti-adhesive composition (dispersion), a method of spraying rubber on a narrow stream, a method of immersing in a dispersion, and the like can be mentioned. The method of immersing in the dispersion is preferable because the anti-vulcanizing rubber composition for unvulcanized rubber can be uniformly attached. The unvulcanized rubber used in the production method of the present invention is usually in a state heated to 100 to 180 ° C., and the unvulcanized rubber can be cooled by a method of immersing it in a dispersion. The temperature of the dispersion is not particularly limited, but is preferably 0 to 60 ° C. Next, a step of drying the unvulcanized rubber after attaching the dispersion may be performed. Although there is no limitation in particular as a drying method, cost may be cheap if it is the method of forcedly drying by sending hot air with a hot air machine or a blow heater.

  The concentration of the dispersion is preferably from 0.01 to 10%, more preferably from 0.05 to 7.5%, more preferably from 0.1 to 5.0, from the viewpoint of easily exhibiting good adhesion and drying properties. % Is more preferable. If it is less than 0.01%, the adhesion resistance may deteriorate, and if it exceeds 10%, the drying property may deteriorate.

In the treatment step, a dry method, that is, a method using an unvulcanized rubber adhesion preventive agent containing no water may be performed.
In the case of the unvulcanized rubber that has been subjected to the adhesion treatment and manufactured as described above, the unvulcanized rubber can be prevented from adhering when stacked and stored until the next step.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to these examples. Each physical property in Examples and Comparative Examples was evaluated as follows.
[Wettability]
An NR / BR test piece (thickness 0.5 cm × length 5 cm × width 3 cm) heated to 100 ° C. is immersed in the anti-vulcanized rubber composition or dispersion composition and immediately pulled up. The immersed rubber test piece was visually observed, and visually evaluated in five stages. The more evenly wet, the higher the adhesion of the anti-adhesive agent.
Based on the following criteria, the cases where the wettability was 5 and 4 were determined to be acceptable.
5: Wet uniformly, the index is ◎
4; Slightly repel, indicator is ○
3; Repel less than 50% of rubber surface, index is △
2; Repel 50% or more of rubber surface, index is x
1; It repels the entire rubber surface and the index is XX

[Adhesion]
An NR / BR test piece (thickness 0.5 cm × length 5 cm × width 3 cm) heated to 100 ° C. is immersed in the anti-vulcanized rubber composition or dispersion composition and immediately pulled up. Two soaked rubber test pieces are produced, air-dried, overlapped, left under a constant temperature bath of 40 ° C. under a load of 1000 kg / m ² for 24 hours. The test piece taken out from the thermostat was air-cooled to room temperature, and the peel resistance (N) was measured at a speed of 100 mm / min using a tensile tester. The smaller the peel resistance, the easier it is to peel off and the higher the adhesion resistance. The evaluation criteria are as follows, and the case where the peel resistance was less than 0.5 N was determined to be acceptable.
Peel resistance of 0.2 N or less: very good adhesion (can easily peel off unvulcanized rubber, index is ◎)
Peel resistance of more than 0.2N and less than 0.5N: Good adhesion (can peel unvulcanized rubber without load, index is ○)
Peel resistance of 0.5N or more and 1N or less: poor adhesion (high load when peeling unvulcanized rubber, low adhesion, index is Δ)
Peel resistance exceeding 1N: very poor adhesion (rubbers are in close contact and difficult to peel. Very low adhesion, index is x)

Example 1
To 99 g of tap water, 1 g of hydroxypropylmethylcellulose (the substitution degree of methoxyl group is 1.8, the substitution mole number of hydroxypropyl group is 0.15, the viscosity of 2% aqueous solution is 6.0 × 10 ⁴ ) is added with stirring, By uniformly dispersing in water, an anti-adhesive composition for 1% unvulcanized rubber (dispersion) was obtained. An NR / BR rubber test piece heated to 100 ° C. was immersed in the obtained dispersion and immediately pulled up. When the wettability of the dispersion liquid to the unvulcanized rubber surface was judged by visual observation, it was uniformly wet and the wettability was 5. Two soaked rubber test pieces were prepared, overlapped when air-dried, and left in a constant temperature bath at 40 ° C. under a load of 1000 kg / m ² for 24 hours. The peel resistance was 0.35 N, and it was possible to peel without load, and the adhesion resistance was excellent.
Further, 98% of tap water and 2 g of the hydroxypropyl methylcellulose were used to obtain an anti-adhesive composition for 2% unvulcanized rubber (dispersion) in the same procedure. When the obtained dispersion was used to evaluate wettability and adhesion, the wettability was 5 and the peel resistance was 0.19 N, indicating excellent wettability and high adhesion.

(Examples 2 to 16)
In Examples 2 to 16, except that the composition was changed as shown in Tables 1 and 2, an anti-adhesive composition for an unvulcanized rubber (dispersion) was obtained and evaluated in the same manner as in Example 1. . The results are shown in Table 1 and Table 2, respectively. They were excellent in wettability and adhesion, and also showed high adhesion.

(Example 17)
Hydroxypropyl methylcellulose (the substitution degree of methoxyl group is 1.8, the substitution mole number of hydroxypropyl group is 0.15, the viscosity of 2% aqueous solution is 6.0 × 10 ⁴ )
15 g of kaolin, 80 g of kaolin and 5 g of sodium 2-ethylhexyl sulfosuccinate were uniformly mixed to obtain an unvulcanized rubber anti-adhesive composition.
Next, 1 g of the above-mentioned anti-adhesive composition was added to 99 g of tap water while stirring and dispersed uniformly in water to obtain an anti-adhesive composition for 1% unvulcanized rubber (dispersion).
An NR / BR rubber test piece heated to 100 ° C. was immersed in the obtained dispersion and immediately pulled up. When the wettability of the dispersion liquid to the unvulcanized rubber surface was judged by visual observation, it was uniformly wet and the wettability was 5. Two soaked rubber test pieces were prepared, overlapped when air-dried, and left in a constant temperature bath at 40 ° C. under a load of 1000 kg / m ² for 24 hours. The peel resistance was 0.3N, and it was possible to peel without load, and the adhesion resistance was excellent.
Further, an anti-adhesive composition for 2% unvulcanized rubber (dispersion liquid) was obtained in the same procedure using 98 g of tap water and 2 g of the anti-adhesive composition. When the obtained dispersion was used to evaluate wettability and adhesion, the wettability was 5 and the peel resistance was 0.17 N, indicating excellent wettability and high adhesion.

(Examples 17 to 34)
In Examples 17 to 34, an unvulcanized rubber anti-adhesive composition (dispersion) was obtained and evaluated in the same manner as in Example 17 except that the composition was changed as shown in Tables 3 and 4. The results are shown in Table 3 and Table 4, respectively. They were excellent in wettability and adhesion, and also showed high adhesion.

(Comparative Example 1)
1 g of hydroxypropylmethylcellulose (the substitution degree of methoxyl group is 0.1, the substitution mole number of hydroxypropyl group is 0.15, the viscosity of 5.0% 10 ⁴ aqueous solution) is added to 99 g of tap water with stirring. When dispersed in water, it was not sufficiently dissolved, and a uniform anti-vulcanized rubber composition (dispersion) could not be obtained. An NR / BR rubber test piece heated to 100 ° C. was immersed in the dispersion and immediately pulled up. When the wettability of the dispersion liquid to the unvulcanized rubber surface was judged by visual observation, repelling was seen on the front surface of the rubber surface and the wettability was 1. Two soaked rubber test pieces were prepared, overlapped when air-dried, and left in a constant temperature bath at 40 ° C. under a load of 1000 kg / m ² for 24 hours. The peel resistance was 1.5 N, and the adhesion resistance was poor.
Further, even when 98 g of tap water and 2 g of the hydroxypropylmethylcellulose were used, a uniform anti-vulcanized rubber composition (dispersion liquid) could not be obtained. When the wettability and adhesion resistance were evaluated using the dispersion, the wettability was 1 and the peel resistance was 1.5 N. The wettability was inferior and sufficient adhesion resistance was not exhibited.

(Comparative Examples 2 to 8)
In Comparative Examples 2 to 8, except that the composition was changed as shown in Tables 5 and 6, an anti-adhesive composition for an unvulcanized rubber (dispersion) was obtained and evaluated in the same manner as in Comparative Example 1. . The results are shown in Table 5 and Table 6, respectively.
In Comparative Examples 2 to 8, the wettability and adhesion were inferior to those of the Examples, and sufficient adhesion resistance was not exhibited.

(Comparative Example 9)
95 g of kaolin and 5 g of sodium 2-ethylhexyl sulfosuccinate were uniformly mixed to obtain an unvulcanized rubber anti-adhesive composition.
Next, 1 g of the above-mentioned anti-adhesive composition was added to 99 g of tap water while stirring and dispersed uniformly in water to obtain an anti-adhesive composition for 1% unvulcanized rubber (dispersion).
An NR / BR rubber test piece heated to 100 ° C. was immersed in the obtained dispersion and immediately pulled up. When the wettability of the dispersion liquid on the surface of the unvulcanized rubber was judged by visual observation, there was some repelling and the wettability was 3. Two soaked rubber test pieces were prepared, overlapped when air-dried, and left in a constant temperature bath at 40 ° C. under a load of 1000 kg / m ² for 24 hours. The peel resistance was 1.2 N, and the adhesion resistance was poor.
Further, an anti-adhesive composition for 2% unvulcanized rubber (dispersion liquid) was obtained in the same procedure using 98 g of tap water and 2 g of the anti-adhesive composition. When the obtained dispersion was used to evaluate wettability and adhesion resistance, the wettability was 5 and the peel resistance was 0.8 N, which did not show sufficient adhesion resistance.
(Comparative Example 10)
In Comparative Example 10, an unvulcanized rubber anti-adhesive composition (dispersion) was obtained and evaluated in the same manner as in Comparative Example 9 except that the composition was changed as shown in Table 6. The results are shown in Table 6.
Comparative Example 10 did not show sufficient anti-adhesion properties compared to the Examples.

  The anti-adhesive agent for unvulcanized rubber of the present invention is used in the production and processing process of unvulcanized rubber products, and is accumulated and stored until the unvulcanized rubber moves to the next molding or vulcanization process. In this case, it is possible to prevent the rubber from sticking. At that time, it can be used at a low concentration, and foreign matter contamination can be reduced. In addition, a strong coating prevents rubber adhesion and greatly improves workability.

Claims (8)

  An anti-adhesive composition for an unvulcanized rubber containing hydroxyalkylmethylcellulose, wherein the hydroxyalkylmethylcellulose has a methoxyl group substitution degree of 0.5 to 2.5, and the hydroxyalkylmethylcellulose has a hydroxyalkyl group substitution mole number. Is an anti-adhesive composition for an unvulcanized rubber, wherein 0.025 to 0.5.   The anti-adhesive composition for unvulcanized rubber according to claim 1, further comprising a water-soluble aldehyde.   The anti-adhesive composition for unvulcanized rubber according to claim 2, wherein the water-soluble aldehyde is at least one selected from formaldehyde, acetaldehyde, propionaldehyde, glyoxal and succinaldehyde. The anti-adhesive composition for unvulcanized rubber according to any one of claims 1 to 3, wherein a viscosity of a 2% aqueous solution of hydroxyalkylmethylcellulose is 5 x 10 ¹ to 1 x 10 ⁷ mPa · s.   The antiadhesive composition for unvulcanized rubber according to any one of claims 1 to 4, further comprising an inorganic powder and / or a surfactant.   The inorganic powder is at least one selected from bentonite, mica, talc, kaolin, amorphous silica, and calcium carbonate, and the surfactant is at least one selected from an anionic surfactant and a nonionic surfactant. The anti-adhesive composition for unvulcanized rubber according to claim 5, which is a seed.   An adhesion-treated unvulcanized rubber comprising a treatment step of adhering the anti-vulcanized rubber composition for unvulcanized rubber according to any one of claims 1 to 6 to the surface of a molded unvulcanized rubber. Manufacturing method.   A rubber product obtained by the method according to claim 7.