JP3229889B2 - Mold cleaning rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition and, more particularly, to a mold cleaning rubber composition used for cleaning a mold whose surface has been contaminated by repeated vulcanization.

[0002]

2. Description of the Related Art In the rubber molding and processing industry, contamination of a vulcanizing mold has been known for a long time, and mold contamination is promoted in the vulcanizing process together with the frequency of use, and the quality of a rubber molded product is improved. There are problems such as giving a serious defect to the product such as appearance and dimensional accuracy, releasing from the mold and shortening the life of the mold. For this reason, a number of studies have been made on mold contamination countermeasures, for example, Japanese Patent Publication No. 59-449.
No. 80, a method of adding an organic phosphate or a cyclopentadiene derivative carboxylate to an outer surface liquid, or a method described in JP-A No. 62-113518 to a compound having silicon and isocyanate groups in a molecule. There has been a method of surface-treating a mold.

Alternatively, there has been proposed a method of using a composition in which various organic compounds are added to a rubber composition. These include cyclized polybutadienes described in JP-A-54-63144, organic phosphoric acid ester salts described in JP-B-57-53812, and JP-A-54-10.
No. 7943, mercaptobenzo-1,3
-Diazole salts, cyclopentadiene derivative carboxylic acid metal salts described in JP-A-54-126251,
2-mercaptobenzimidazole or a zinc salt thereof described in JP-B-61-20585;
No. 238143 discloses an attempt to improve mold contamination by blending a specific silica, hydrous silicic acid, or the like.

[0004] In addition, periodic cleaning of a mold, for example, a shot blast method using glass beads or the like, acid or alkali cleaning, and the like are performed. As a method for cleaning the mold without removing it from the vulcanizer, a mold cleaning rubber composition is commercially available. These contain a large amount of amine-based chemicals which are almost easily decomposed, such as 2-amino-2-methyl-1-propanol and aminoethyldiethyleneamine. Examples of these rubber compositions include glycol ethers described in JP-A-63-105099, lactams and organic cyclic imides which are organic cyclic compounds described in JP-A-3-161309. JP Hei 3
161310 has proposed an alkylene oxide adduct of an alkylamine.

[0005]

However, the method of blending various organic compounds in the rubber composition can delay the contamination, but cannot completely prevent the contamination. Periodic mold cleaning not only damages the mold and speeds up the subsequent contamination and corrodes the mold, but also requires the mold to be removed from the vulcanizer for cleaning, especially for tires, etc. In the case of a large rubber product, the man-hour cannot be ignored and there is a disadvantage that productivity is reduced. In addition, although the mold cleaning rubber composition has a certain effect, it cannot be said that it is still sufficient.Moreover, most of these cleaning rubber compositions are easily decomposed amines, so that ammonia odor is generated even at room temperature, Thereafter, a large amount of amines and the like is generated, which corrodes the mold and is extremely problematic in the working environment.

The present invention provides a rubber mold cleaning rubber composition which is excellent in mold cleaning effect, has good productivity, does not damage or corrode the mold, and improves the working environment. The purpose is to:

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problem, that is, damage or corrosion of a mold or a problem in a working environment. As a result, the present inventors have found that a rubber composition containing a water-glycol-based low-viscosity hydraulic fluid known as a hydraulic oil for hydraulic devices has a remarkable cleaning effect, and completed the present invention.

[0008] More specifically, a mold cleaning rubber composition containing 1 to 100 parts by weight of a working fluid liquid containing water and glycols as main components based on 100 parts by weight of a rubber made of natural rubber and / or synthetic rubber. Alternatively, a mold cleaning rubber composition containing 1 to 200 parts by weight of an adsorbent to these mold cleaning rubber compositions, or a metal having a water content of 5 to 80% by weight of the working fluid. It is a mold cleaning rubber composition. In the rubber composition of the present invention, as the rubber, natural rubber,
Synthetic polyisoprene rubber, styrene-butadiene copolymer rubber, polybutadiene rubber, ethylene-propylene diene terpolymer rubber, butyl rubber, halogenated butyl rubber, etc. are used. These may be used alone or by blending two or more. However, natural rubber or synthetic polyisoprene rubber having high adhesiveness is preferable.

In the rubber composition of the present invention, the liquid containing water and glycols as main components includes, for example, a water-glycol-based hard-to-viscosity hydraulic fluid, which is used for a hydraulic device or the like that handles a high heat metal. Hydraulic fluid that contains water and glycols such as polyethylene glycol
As a main component , a high-molecular polymer and an antifoaming agent are added as needed for viscosity adjustment, and a rust inhibitor is added for the purpose of preventing metal rust.

These products include, for example, New Highland FRG46 and New Highland FRG32 manufactured by Nippon Oil Co., Ltd., Cosmo Fluid HY32 and Cosmo Fluid HQ46 manufactured by Cosmo Oil Co., Ltd., GW Fluid manufactured by Showa Shell Sekiyu KK, Mobil Oil Co., Ltd. Nyvac FR2000 Fluid, Mobil Hydro Fluid HFC, Hydria G manufactured by Kyodo Sekiyu Co., Ltd. and BP, Enorg manufactured by Vetrub International Co., Ltd.
olSF-15 and the like, and two or more of these may be used in combination, but the present invention is not limited to these.
Liquid containing as a main component working fluid and the other water <br/> and glycols water glycol having similar effects are also included.

The amount of these liquids is 1 to 100 parts by weight. If the compounding amount is less than 1 part by weight, the cleaning effect is not sufficient, and if it exceeds 100 parts by weight, not only is it difficult to knead the working fluid into the rubber composition during kneading, but also a part of the liquid Remains undesirably. The water content of these liquids is from 5 to 80% by weight, preferably from 20 to 60% by weight, and if the amount of water is larger or smaller than this range, the cleaning effect deteriorates, which is not preferable.

In the present invention, it is necessary to peel off contaminants from the mold and remove them by adsorbing them to the rubber composition. For this purpose, if an adsorbent is used in combination as required, the cleaning effect is synergistically improved. . Further, when the above liquid is kneaded into rubber, the rubber is impregnated with these adsorbents and kneaded, whereby the rubber is kneaded more smoothly. As these adsorbents, silica, activated alumina, activated carbon, magnesium oxide, titanium oxide, magnesium carbonate, calcium carbonate, starch, bentonite, diatomaceous earth, etc. are used.When the rubber composition is taken out after washing the mold, In the case of a mold having a complicated shape, the rubber composition may be formed in the middle and may remain in the mold. Therefore, silica having a reinforcing property is preferably used.

The amount of these adsorbents is 1 to 200 parts by weight per 100 parts by weight of rubber. These adsorbents are added when the above-mentioned liquid is kneaded with rubber. If the amount is less than 1 part by weight, the mold cleaning effect is not sufficient,
If the amount exceeds 0 parts by weight, not only the effect of increasing the amount cannot be exhibited, but also the viscosity of the rubber composition becomes too high, so that the rubber composition cannot sufficiently flow into every corner of the mold, and uncleaned portions remain. Therefore, it is not preferable. In the rubber composition of the present invention, carbon black, clay, fillers such as calcium carbonate, aroma oils, softeners such as naphthenic oil, vulcanizing agents such as sulfur and vulcanization accelerators commonly used in the rubber industry are used. , An anti-aging agent and the like can be added as needed. The rubber composition of the present invention is suitably used for cleaning a mold for vulcanizing any rubber product such as a tire.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. (Example 1) Various rubber compositions having the composition shown in Table 1 were kneaded to prepare an unvulcanized rubber sheet having a thickness of 2 mm. Of these various rubber sheets, six types of Examples 1 to 5 and Comparative Example were affixed to the entire surface of a raw tire having a tire size of 135SR12 by dividing the surface into six equal parts. The remaining rubber sheets, Examples 6 to 10 and the conventional example were also affixed in six equal parts to the entire surface of a green tire of the same size. These two
The same kind of green tire was continuously vulcanized for two weeks, so that it was put into a mold whose surface was contaminated with black and vulcanized for 15 minutes, and the tire was taken out as usual. The cleaning degree of the mold at that time was visually evaluated. The case where cleaning was not performed at all was evaluated as 0, and the case where cleaning was performed completely was evaluated as 5, and evaluated in 6 levels. The results are shown in Table 1.

[0015]

[Table 1]

The compounding contents of the prior art are described in Polymer No. 11, Vol. 11, pp. 693-695. 100 parts by weight of EPDM, 20 parts by weight of silica, 30 parts by weight of 2-amino-1-propanol, oxidized Titanium 10
Parts by weight, stearic acid 1 part by weight, zinc white 5 parts by weight, dicumyl peroxide 9 parts by weight, and sulfur 0.3 parts by weight. As is clear from Table 1, the mold cleaning rubber compositions of the present invention shown in the examples have remarkably excellent cleaning effects.

[0017]

According to the present invention, the cleaning effect is excellent.
Since no amine-based chemical is used unlike the conventional cleaning rubber, there is no problem in hygiene. Conventionally, cleaning of a mold for a tire has taken a lot of man-hours because the mold was removed and washed by shot blasting with glass beads or the like.However, if the mold cleaning rubber composition of the present invention is used, a great deal of work is required. Man-hour reduction and damage to the mold surface can be remarkably improved.

Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI C11D 7:26) C11D 7:26) (56) References JP-A-1-297411 (JP, A) JP-A-63-105099 (JP, A) JP-A-3-161309 (JP, A) JP-A-2-20538 (JP, A) JP-A-60-67532 (JP, A) JP-A-6-507581 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) B29C 33/00-33/76 C08L 21/00 C11D 7/60

Claims (3)

(57) [Claims] 1. Water and glycols are the main components with respect to 100 parts by weight of rubber made of natural rubber and / or synthetic rubber.
A mold cleaning rubber composition containing 1 to 100 parts by weight of a liquid for working fluid. 2. Water and glycols are the main components with respect to 100 parts by weight of rubber made of natural rubber and / or synthetic rubber.
1 to 100 parts by weight of the working fluid liquid and the adsorbent 1
A rubber composition for cleaning a mold, which further comprises -200 parts by weight. 3. The water content of the working liquid is 5-8.
The mold cleaning rubber composition according to claim 1 or 2, which is 0% by weight.