JP6496707B2 - Rubber release agent, rubber release agent water dispersion, rubber, and method for producing rubber - Google Patents

Description

The present invention relates to a release agent for rubber, an aqueous dispersion of a release agent for rubber, rubber, and a method for producing the rubber.

In the field of rubber production and processing, for the purpose of preventing adhesion of rubber (for example, unvulcanized rubber), a release agent (adhesion prevention agent) is attached to the surface of the rubber.

As rubber release agents, rubber release agents mainly composed of inorganic powder are widely used.
These can generally be used in the form of an aqueous dispersion and then attached to the rubber surface (Patent Documents 1 to 7, etc.).

In order for the rubber release agent to exhibit good release properties, it is necessary that the adhesion to the rubber surface be high. For this reason, various devices have been made to enhance the adhesion of the release agent for rubber.
For example, in Patent Documents 1 to 3, an inorganic powder such as bentonite is used in combination with a surfactant, a metal soap, or the like in order to improve the mold release (adhesion) effect. In order to improve the adhesion to the rubber surface, various anti-adhesive agents (release agents) in which latex, water-soluble polymer and the like are used in combination with inorganic powder have been proposed. For example, in Patent Documents 4 to 7, a water-soluble polymer (swelling inorganic powder)
Sodium alginate, CMC, sodium polyacrylate, PVA, etc.), water-soluble polysaccharides (xanthan gum), etc. are added to increase the viscosity of the aqueous dispersion of the anti-adhesive agent and improve the adhesion of the anti-adhesive agent to the rubber surface I am letting.

JP 50-149770 JP 59-19134 JP2011-144221A JP 53-061639 JP 62-032127 JP2009-161667A JP2009-249533

When the rubber mold release agent is used after being dispersed in water, the pH may be lowered by a chemical compounded in rubber (for example, an unvulcanized rubber sheet or the like). Due to this change in pH, aggregation of the components in the release agent occurs, the adhesion state to the rubber surface deteriorates, and releasability (adhesion)
There is a possibility that performance such as the above cannot be exhibited.

Moreover, in patent documents 4-7, as above-mentioned, the adhesiveness to the rubber surface is improved by raising the viscosity of a mold release agent aqueous dispersion. However, if the viscosity of the release agent aqueous dispersion is too high,
Drying takes time, and there is a risk that the rubber adheres to the undried portion (cannot exhibit releasability). Further, because of this problem, it is necessary to strictly control the viscosity of the aqueous dispersion by controlling the concentration of the release agent aqueous dispersion. For this reason, the concentration range of the aqueous dispersion that can be used is narrowed, and the degree of difficulty in controlling the concentration at the site of use of the release agent is increased. That is, the usability of the release agent for rubber is deteriorated.

Therefore, an object of the present invention is to provide a rubber release agent excellent in both usability and releasability, a rubber release agent aqueous dispersion using the same, a rubber, and a method for producing the rubber.

In order to achieve the above object, a first release agent for rubber according to the present invention is a release agent for rubber that contains inorganic powder and is used by adhering to a rubber surface. The pH of the dispersion liquid when 2.0 g of the agent is dispersed is more than 8.0.

The second release agent for rubber of the present invention is a release agent for rubber that contains inorganic powder and is used by adhering to the rubber surface, and further contains mineral oil.

The rubber release agent aqueous dispersion of the present invention is a rubber release agent aqueous dispersion in which the first or second rubber release agent of the present invention is dispersed in water.

The rubber of the present invention is characterized in that the first or second rubber release agent of the present invention is attached to the surface of the rubber and is subjected to a release treatment.

The rubber production method according to the present invention includes a mold release treatment in which the rubber release agent aqueous dispersion of the present invention is adhered to the surface of a rubber that has not been subjected to a mold release treatment, and the water is volatilized. It is a manufacturing method of the rubber of the present invention including a process.

ADVANTAGE OF THE INVENTION According to this invention, the mold release agent for rubber excellent in both usability and mold release property, the mold release agent water dispersion liquid using the same, rubber | gum, and the manufacturing method of rubber | gum can be provided.

Hereinafter, the present invention will be described with examples. However, the present invention is not limited by the following description.

In the first release agent for rubber of the present invention, 100 to 100 g of water, 1.5 to 4 of the release agent for rubber.
. The pH of the dispersion when 0 g is dispersed is preferably more than 8.0, and the pH of the dispersion when 0.5 to 10.0 g of the rubber release agent is dispersed in 100 g of water is 8. More preferably, it exceeds 0. In the first release agent for rubber of the present invention, the p of the aqueous dispersion is used.
It is preferable that H is 9.0 or more. In the first release agent for rubber of the present invention, the pH of the aqueous dispersion is preferably 11.0 or less, and more preferably 10.0 or less.

The first release agent for rubber according to the present invention preferably further contains a pH buffer. The pH buffer is not particularly limited, but is preferably at least one selected from the group consisting of carbonates, phosphates, silicates, and dibasic acid salts. The first release agent for rubber according to the present invention more preferably contains 1 to 30 parts by weight of the pH buffering agent with respect to 100 parts by weight of the inorganic powder.

In the first release agent for rubber of the present invention, it is preferable that the inorganic powder includes finely divided inorganic powder. In the first release agent for rubber of the present invention, the inorganic powder preferably contains a water-swellable inorganic powder.

In the first release agent for rubber according to the present invention, the inorganic powder preferably contains bentonite. The bentonite is more preferably a water-swellable bentonite. In the case where the first release agent for rubber of the present invention contains bentonite, the content of the bentonite with respect to the inorganic powder is more preferably 5 to 100% by weight, and still more preferably 3
It is 0 to 100% by weight, more preferably 50 to 100% by weight. In this case, it is more preferable that the inorganic powder further includes at least one inorganic powder selected from the group consisting of clay, talc, mica, and alkaline earth metal carbonate. Examples of the alkaline earth metal carbonate include calcium carbonate and magnesium carbonate.

The first rubber mold release agent of the present invention preferably further contains a surfactant. In this case, the content of the surfactant is not particularly limited, but is preferably 1 to 50 parts by weight, more preferably 2 to 30 parts by weight, particularly preferably 5 to 100 parts by weight of the inorganic powder. ~ 20 parts by weight.

The first rubber mold release agent of the present invention may further contain mineral oil. The mineral oil is not particularly limited, but preferably includes at least one of paraffinic oil and naphthenic oil. Further, in the case where the first rubber mold release agent of the present invention contains mineral oil, the content of the mineral oil is not particularly limited, but the mineral oil is reduced to 0 with respect to 100 parts by weight of the inorganic powder. It is preferable to contain 5 parts by weight or more, and more preferably 0.5 to 30 parts by weight of the mineral oil with respect to 100 parts by weight of the inorganic powder.

The first rubber release agent of the present invention may be used for any rubber, but is preferably an unvulcanized rubber release agent.

In the aqueous rubber release agent dispersion of the present invention in which the first rubber release agent of the present invention is dispersed in water, the content of the first rubber release agent of the present invention is as follows. Is not particularly limited,
For example, 0.5 to 10.0 g, preferably 1.5 to 4.0 g, particularly preferably 2.0 g with respect to 100 g of water. Further, the pH of the rubber release agent aqueous dispersion of the present invention, in which the first rubber release agent of the present invention is dispersed in water, is preferably a value exceeding 8.0, more preferably. Is 9.0 or more. The upper limit of the pH is not particularly limited, but is preferably 11.0 or less, more preferably 10.0 or less, from the viewpoint of easy handling of the rubber release agent aqueous dispersion of the present invention. .

Next, in the second release agent for rubber according to the present invention, the mineral oil preferably contains at least one of paraffinic oil and naphthenic oil.

In the second release agent for rubber of the present invention, it is preferable that the inorganic powder includes finely divided inorganic powder. In the second release agent for rubber according to the present invention, the inorganic powder preferably contains a water-swellable inorganic powder.

In the second release agent for rubber of the present invention, the inorganic powder preferably contains bentonite. The bentonite is more preferably a water-swellable bentonite. In the case where the second release agent for rubber of the present invention contains bentonite, the content of the bentonite with respect to the inorganic powder is more preferably 5 to 100% by weight, still more preferably 3
It is 0 to 100% by weight, more preferably 50 to 100% by weight. Further, in the second release agent for rubber of the present invention, the inorganic powder further comprises at least one inorganic powder selected from the group consisting of clay, talc, mica, and alkaline earth metal carbonate. More preferably. Examples of the alkaline earth metal carbonate include calcium carbonate and magnesium carbonate.

The second release agent for rubber of the present invention preferably contains 0.5 parts by weight or more of the mineral oil with respect to 100 parts by weight of the inorganic powder, More preferably, it contains 0.5 to 30 parts by weight of mineral oil.

The second rubber mold release agent of the present invention preferably further contains a surfactant. In this case, the content of the surfactant is not particularly limited, but is preferably 1 to 50 parts by weight, more preferably 2 to 30 parts by weight, particularly preferably 5 to 100 parts by weight of the inorganic powder. ~ 20 parts by weight.

The second rubber release agent of the present invention may be used for any rubber, but is preferably an unvulcanized rubber release agent.

  The rubber of the present invention is not particularly limited, and may be, for example, an unvulcanized rubber.

The first rubber mold release agent of the present invention, and the rubber mold release agent aqueous dispersion of the present invention, rubber, and a method for producing the rubber are, for example, the following (1) to (38): However, the present invention is not limited to this.

(1) A release agent for rubber which contains inorganic powder and is used by adhering to a rubber surface.
A release agent for rubber, wherein 2.0 g of the release agent for rubber is dispersed in g, and the pH of the dispersion exceeds 8.0.

(2) p of the dispersion when the rubber mold release agent 1.5-4.0 g is dispersed in 100 g of water.
The mold release agent for rubber according to (1), wherein H exceeds 8.0.

(3) The rubber mold release agent according to (1), wherein the pH of the dispersion liquid when the rubber mold release agent 0.5 to 10.0 g is dispersed in 100 g of water exceeds 8.0.

(4) The mold release agent for rubber according to any one of (1) to (3), wherein the pH of the aqueous dispersion is 9.0 or more.

(5) The mold release agent for rubber according to any one of (1) to (4), wherein the pH of the aqueous dispersion is 11.0 or less.

(6) The release agent for rubber according to any one of (1) to (4), wherein the pH of the aqueous dispersion is 10.0 or less.

(7) The mold release agent for rubber according to any one of (1) to (6), further comprising a pH buffer.

(8) The release agent for rubber according to (7), wherein the pH buffer is at least one selected from the group consisting of carbonates, phosphates, silicates, and dibasic acid salts.

(9) 1 to 30 parts by weight of the pH buffering agent is included with respect to 100 parts by weight of the inorganic powder.
) Or (8) rubber release agent.

(10) The mold release agent for rubber according to any one of (1) to (9), wherein the inorganic powder includes finely divided inorganic powder.

(11) The release agent for rubber according to any one of (1) to (10), wherein the inorganic powder includes a water-swellable inorganic powder.

(12) The mold release agent for rubber according to any one of (1) to (11), wherein the inorganic powder contains bentonite.

(13) The release agent for rubber according to (12), wherein the bentonite is water-swellable bentonite.

(14) The rubber mold release agent according to (12) or (13), wherein the bentonite content relative to the inorganic powder is 5 to 100% by weight.

(15) The release agent for rubber according to (12) or (13), wherein the bentonite content relative to the inorganic powder is 30 to 100% by weight.

(16) The release agent for rubber according to (12) or (13), wherein the bentonite content relative to the inorganic powder is 50 to 100% by weight.

(17) The inorganic powder further includes at least one kind of inorganic powder selected from the group consisting of clay, talc, mica, and alkaline earth metal carbonate (12) to (16
The mold release agent for rubber according to any one of 1).

(18) The mold release agent for rubber according to (17), wherein the alkaline earth metal carbonate contains at least one of calcium carbonate and magnesium carbonate.

(19) The mold release agent for rubber according to any one of (1) to (18), further comprising a surfactant.

(20) The release agent for rubber according to (19), wherein the content of the surfactant is 1 to 50 parts by weight with respect to 100 parts by weight of the inorganic powder.

(21) The mold release agent for rubber according to (19), wherein the content of the surfactant is 2 to 30 parts by weight with respect to 100 parts by weight of the inorganic powder.

(22) The release agent for rubber according to (19), wherein the content of the surfactant is 5 to 20 parts by weight with respect to 100 parts by weight of the inorganic powder.

(23) The mold release agent for rubber according to any one of (1) to (22), further comprising mineral oil.

(24) The rubber mold release agent according to (23), wherein the mineral oil contains at least one of paraffinic oil and naphthenic oil.

(25) 0.5 parts by weight or more of the mineral oil is included with respect to 100 parts by weight of the inorganic powder.
23) or a release agent for rubber according to (24).

(26) The mineral oil is included in an amount of 0.5 to 30 parts by weight with respect to 100 parts by weight of the inorganic powder.
(23) or the mold release agent for rubbers as described in (24).

(27) The rubber release agent according to any one of (1) to (26), which is a release agent for unvulcanized rubber.

(28) A rubber release agent aqueous dispersion in which the rubber release agent according to any one of (1) to (27) is dispersed in water.

(29) The rubber release agent aqueous dispersion according to (28), wherein the content of the rubber release agent is 0.5 to 10.0 g with respect to 100 g of water.

(30) The rubber mold release agent content is 1.5 to 4.0 g with respect to 100 g of water.
(28) The rubber mold release agent aqueous dispersion described in (28).

(31) The content rate of the said mold release agent for rubbers is 2.0g with respect to 100g of water, (28)
The rubber mold release agent aqueous dispersion described in 1.

(32) The release agent aqueous dispersion for rubber according to any one of (28) to (31), wherein the pH exceeds 8.0.

(33) The rubber release agent aqueous dispersion according to any one of (28) to (31), wherein the pH is 9.0 or more.

(34) The release agent aqueous dispersion for rubber according to any one of (28) to (33), wherein the pH is 11.0 or less.

(35) The rubber release agent aqueous dispersion according to any one of (28) to (33), which has a pH of 10.0 or less.

(36) A rubber characterized in that the rubber release agent according to any one of (1) to (27) is attached to the surface of the rubber and subjected to a release treatment.

(37) The rubber according to (36), which is an unvulcanized rubber.

(38) The rubber release agent aqueous dispersion described in any one of (28) to (35) is attached to the surface of the rubber that has not been subjected to the mold release treatment, and the mold release treatment is performed by volatilizing water. The method for producing rubber according to (36) or (37), comprising a mold release treatment step.

The second rubber mold release agent of the present invention and the rubber mold release agent aqueous dispersion of the present invention, rubber, and a method for producing the rubber are, for example, the following (39) to (60): However, the present invention is not limited to this.

(39) A rubber mold release agent comprising an inorganic powder and used by adhering to a rubber surface, further comprising mineral oil.

(40) The rubber release agent according to (39), wherein the mineral oil contains at least one of paraffinic oil and naphthenic oil.

(41) The mold release agent for rubber according to (39) or (40), wherein the inorganic powder includes finely divided inorganic powder.

(42) The mold release agent for rubber according to any one of (39) to (41), wherein the inorganic powder includes a water-swellable inorganic powder.

(43) The mold release agent for rubber according to any one of (39) to (42), wherein the inorganic powder contains bentonite.

(44) The mold release agent for rubber according to (43), wherein the bentonite is water-swellable bentonite.

(45) The release agent for rubber according to (43) or (44), wherein the bentonite content relative to the inorganic powder is 5 to 100% by weight.

(46) The rubber mold release agent according to (43) or (44), wherein the bentonite content relative to the inorganic powder is 30 to 100% by weight.

(47) The rubber mold release agent according to (43) or (44), wherein the bentonite content relative to the inorganic powder is 50 to 100% by weight.

(48) The inorganic powder further comprises at least one inorganic powder selected from the group consisting of clay, talc, mica, and alkaline earth metal carbonate (43) to (47)
The mold release agent for rubber according to any one of 1).

(49) The mold release agent for rubber according to (48), wherein the alkaline earth metal carbonate contains at least one of calcium carbonate and magnesium carbonate.

(50) 0.5 parts by weight or more of the mineral oil with respect to 100 parts by weight of the inorganic powder.
The release agent for rubber according to any one of 39) to (49).

(51) The mineral oil is included in an amount of 0.5 to 30 parts by weight with respect to 100 parts by weight of the inorganic powder.
The release agent for rubber according to any one of (39) to (49).

(52) The release agent for rubber according to any one of (39) to (51), further comprising a surfactant.

(53) The release agent for rubber according to (52), wherein the content of the surfactant is 1 to 50 parts by weight with respect to 100 parts by weight of the inorganic powder.

(54) The release agent for rubber according to (52), wherein the content of the surfactant is 2 to 30 parts by weight with respect to 100 parts by weight of the inorganic powder.

(55) The release agent for rubber according to (52), wherein the content of the surfactant is 5 to 20 parts by weight with respect to 100 parts by weight of the inorganic powder.

(56) The release agent for rubber according to any one of (39) to (55), which is a release agent for unvulcanized rubber.

(57) A rubber release agent aqueous dispersion in which the rubber release agent according to any one of (39) to (56) is dispersed in water.

(58) A rubber characterized in that the rubber release agent according to any one of (39) to (56) is attached to the surface of the rubber and subjected to a release treatment.

(59) The rubber according to (58), which is an unvulcanized rubber.

(60) A mold release treatment step in which the rubber release agent aqueous dispersion according to (57) is attached to the surface of a rubber that has not been subjected to a mold release treatment, and the mold release treatment is performed by volatilizing water. (58
) Or the method for producing rubber according to (59).

Hereinafter, embodiments of the present invention will be described more specifically. However, the present invention is not limited to the following embodiments.

[1. First rubber mold release agent]
As described above, the first release agent for rubber according to the present invention is a release agent for rubber that contains inorganic powder and is used by adhering to a rubber surface. It is characterized in that the pH of the dispersion liquid when 8.0 g is dispersed exceeds 8.0. The first release agent for rubber according to the present invention has high adhesion to the rubber surface and good releasability (adhesion resistance) because the pH of the aqueous dispersion is in the numerical range. It is. The reason for this is not necessarily clear, but, for example, when the pH is in the above numerical range, the viscosity of the rubber release agent aqueous dispersion becomes an appropriate range, and the water dispersion wets the rubber surface. It is presumed that the inorganic powder can be prevented from agglomeration and the like while the properties are enhanced. However, this assumption does not limit the present invention. The pH is
It is preferably in the range of more than 8.0 and 11.0 or less, and particularly preferably in the range of 9.0 to 10.0.

Further, the first release agent for rubber of the present invention has good adhesion to the rubber surface without increasing the viscosity of the aqueous dispersion with a thickener or the like. Therefore, the first release agent for rubber of the present invention is
Since there is no difficulty in drying due to the viscosity of the aqueous dispersion being too high, and there is no difficulty in controlling the concentration of the aqueous dispersion, it is easy to use. As will be described later, the same applies to the second release agent for rubber of the present invention.

Examples of the inorganic powder include bentonite, clay, talc, mica, and alkaline earth metal carbonate as described above. Examples of the alkaline earth metal carbonate include:
Examples include calcium carbonate and magnesium carbonate.

Moreover, although the said inorganic powder is not specifically limited, As above-mentioned, it is preferable that a water-swellable inorganic powder is included. The water-swellable inorganic powder can impart, for example, improved adhesion amount and dispersion stability to a rubber release agent. The water-swellable inorganic powder refers to an inorganic powder having a property of increasing the volume by absorbing water, and is not particularly limited. For example, it may be a kind of colloid-containing aluminum silicate having a three-layer structure. Examples of the water-swellable inorganic powder include, but are not limited to, the water-swellable bentonite described above. More specifically, the water-swellable inorganic powder includes, for example, bentonite, piderite, nontronite, saponite, hectorite, aluminum magnesium silicate, and silicic anhydride, which may be natural products or synthetic products. But it ’s okay. The water-swellable inorganic powder may be used alone or in combination. In addition, the water-swellable inorganic powder is particularly preferably bentonite from the viewpoint of improving the adhesion amount and dispersion stability. The bentonite preferably has a montmorillonite content of 40% by weight or more in the bentonite. The montmorillonite content can be measured according to the Japan Bentonite Industry Association Standard Test Method (JBAS-107-91). Moreover, it is preferable that the said bentonite has as little crystalline silica content as possible from a viewpoint of the influence on a human body. The bentonite is particularly preferably bentonite whose bentonite 5 wt% aqueous dispersion has a viscosity of 50 mPa · s (25 ° C.) or more. In the present invention, the viscosity of the bentonite aqueous dispersion can be measured, for example, by the following method. That is, first, water is put in a glass container, bentonite is added at an arbitrary ratio while stirring, and dispersed in water. The disperser is not particularly limited, and may be a general disperser, and examples thereof include a homomixer and a homodisper. The dispersion is allowed to stand for 30 minutes, and then the viscosity after 6 rpm and 1 minute is measured with a B-type viscometer. In addition, this measuring method is an illustration and does not limit this invention.

The content of the water-swellable inorganic powder in the first release agent for rubber of the present invention is not particularly limited, but is, for example, 10 to 90% by weight based on the total weight of the release agent for rubber of the present invention. Preferably it is 30-80 weight%, More preferably, it is 50-80 weight%. From the viewpoint of imparting improved adhesion amount and high dispersion stability to the rubber release agent of the present invention and preventing separation in water, it is preferable that the content of the water-swellable inorganic powder is not too low. Moreover, it is preferable that the content rate of the said water swelling inorganic powder is not too high from a viewpoint of preventing the dispersibility fall of the mold release agent for rubber | gum of this invention, and a drying fall.

In the 1st release agent for rubbers of this invention, as mentioned above, it is preferable that the said inorganic powder contains fine powder inorganic powder. The fine inorganic powder is not particularly limited, and examples thereof include bentonite, clay, talc, and mica. Moreover, although the average particle diameter of the said fine powder inorganic powder is not specifically limited, For example, 0.1-50 micrometers, Preferably it is 0.1-30 micrometers, More preferably, it is 0.1-10 micrometers. In the case where the first release agent for rubber of the present invention contains finely divided inorganic powder, the content of the finely divided inorganic powder with respect to the inorganic powder is preferably 30 to 100% by weight, more preferably 50 to 100% by weight. More preferably, it is 70 to 100% by weight. In the first rubber mold release agent of the present invention, the “average particle diameter” of the finely divided inorganic powder is:
Unless otherwise specified, it refers to the weight average particle diameter measured using a laser diffraction scattering method. The average particle size of the fine powder inorganic powder can be measured, for example, by a particle size distribution measuring device, and more specifically, for example, measured by JIS Z 8825-1 (Particle size breaking-laser diffraction method). Can do. However, this measurement method is an example, and the present invention is not limited to this measurement method.

The first rubber mold release agent of the present invention may or may not contain other components than the inorganic powder. For example, the first rubber mold release agent of the present invention preferably further includes a pH buffer as described above. The rubber release agent contains a pH buffer,
Even when there is a pH lowering factor (for example, a drug compounded in rubber), the pH
The buffering agent can buffer (control) the pH and maintain an appropriate pH range. The pH buffer is not particularly limited, and examples thereof include carbonates, phosphates, silicates, and organic acid salts. Although it does not specifically limit as said carbonate, For example, sodium carbonate, trisodium hydrogencarbonate, potassium carbonate, ammonium carbonate, ammonium hydrogencarbonate, etc. are mentioned. The phosphate is not particularly limited, and examples thereof include trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium tetrapolyphosphate, and pyrolin. Potassium acid, potassium tripolyphosphate, etc. Examples of the silicate include sodium metasilicate, sodium sesquisilicate, sodium orthosilicate, sodium aluminosilicate, potassium silicate, and the like. Although it does not specifically limit as said organic acid salt, For example, dibasic acid salts, such as terephthalic acid and adipic acid, and polycarboxylic acid salt are mentioned. Among these, carbonate, phosphate, silicate, and dibasic acid salt are preferable. Examples of these salts include inorganic metal salts such as sodium and potassium, and organic salts such as diethanolamine and triethanolamine, among which sodium salts and potassium salts are preferred because of their versatility.

The first rubber mold release agent of the present invention preferably further contains a surfactant as described above. The surfactant is not particularly limited and may be a cationic surfactant, a nonionic surfactant, or an anionic surfactant, but at least one of a nonionic surfactant and an anionic surfactant Is preferred. Examples of the nonionic surfactant include [1] polyoxyalkylene alkyl ethers such as polyoxyethylene cetyl ether and polyoxyethylene lauryl ether, [2] polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether and the like. Polyoxyalkylene alkyl phenyl ether, [3] polyoxyalkylene fatty acid ester such as polyoxyethylene monolaurate, polyoxyethylene monooleate, [4] polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate Polyoxyalkylene sorbitan fatty acid esters such as [5] polyoxyalkylene hydrogenated castor oil, [
6] polyoxyalkylene sorbitol fatty acid ester, [7] polyglycerin fatty acid ester, [8] alkyl glycerin ether, [9] polyoxyalkylene cholesteryl ether, [10] alkyl polyglucoside, [11] sucrose fatty acid ester, [12 ]
Polyoxyalkylene alkylamine, [13] oxyethylene-oxypropylene block polymer, etc. are mentioned. Examples of the anionic surfactant include [1] fatty acid salts such as sodium oleate, potassium palmitate, triethanolamine oleate, [2] sodium lauryl sulfate, ammonium lauryl sulfate, sodium stearyl sulfate, sodium cetyl sulfate and the like. [3] polyoxyalkylene alkyl ether acetates such as sodium polyoxyethylene tridecyl ether acetate, [3]
4] Alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate, [5]
Polyoxyalkylene alkyl ether sulfate, [6] stearoyl methyl taurine Na
Higher fatty acid amide sulfonates such as lauroylmethyl taurine Na, myristoyl methyl taurine Na, palmitoyl methyl taurine Na, [7] N-acyl sarcosine salts such as sodium lauroyl sarcosine, [8] alkyl phosphorus such as sodium monostearyl phosphate Acid salts, polyoxyalkylene alkyl ether phosphates such as [9] sodium polyoxyethylene oleyl ether phosphate, sodium polyoxyethylene stearyl ether phosphate, [10] sodium di-2-ethylhexyl sulfosuccinate, dioctyl sulfosuccinic acid Long chain sulfosuccinates such as sodium, [11] sodium N-lauroyl glutamate monosodium, N-stearoyl-L-glutamate disodium, etc. Salt, and the like. Although the total content of the surfactant is not particularly limited, for example, 0 to 15% by weight with respect to the total weight of the rubber release agent of the present invention,
Preferably it is 0 to 10 weight%, More preferably, it is 1 to 7 weight%.

As said other component, you may use a fatty-acid salt hardly soluble in water, for example, fatty-acid calcium, fatty-acid zinc, fatty-acid aluminum, fatty-acid magnesium, etc. as a lubricity imparting agent, for example. The fatty acid salt is preferably added in powder form. When the release agent for rubber of the present invention contains the fatty acid salt, the total content thereof is not particularly limited, but is 0 to 40% by weight, for example, with respect to the total weight of the release agent for rubber of the present invention, Preferably 0-30% by weight, more preferably 5-1
5% by weight.

Moreover, as said other component, a polyhydric alcohol is mentioned, for example. The polyhydric alcohol is not particularly limited. For example, [1] polyethylene glycols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, and hexaethylene glycol; Polypropylene glycols such as propylene glycol, tripropylene glycol, tetrapropylene glycol, pentapropylene glycol and hexapropylene glycol, [3] polybutylene such as dibutylene glycol, tributylene glycol, tetrabutylene glycol, pentabylene glycol and hexabutylene glycol Glycols, [4] ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol 1,2-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,2-decanediol, 1,10-decanediol, 1 , 2-decanediol, 1,
12-dodecanediol, 1,2-dodecanediol, 1,14-tetradecanediol, 1,2-tetradecanediol, 1,16-hexadecanediol, 1,2-hexadecanediol, 2-methyl-2,4-pentanediol 3-methyl-1,5-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-
2,4-dimethylpentanediol, 2,2-diethyl-1,3-propanediol, 2
, 2,4-trimethyl-1,3-pentanediol, dimethyloloctane, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 2-methyl-1,8- Octanediol, 2-butyl-2-ethyl-1,3-propanediol,
2,4-diethyl-1,5-pentanediol, 1,2-cyclohexanediol, 1,
4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cycloheptanediol, tricyclodecane dimethanol, glycerin, trimethylolpropane, 1,2,6-hexanetriol, 3-methylpentane-1,3 , 5-triol, hydroxymethylhexanediol, trimethyloloctane, polyethylene glycol,
Examples thereof include polypropylene glycol, polyethylene glycol polypyropylene glycol, and copolymers thereof. When the rubber mold release agent of the present invention contains the polyhydric alcohol, the content is not particularly limited, but is, for example, 0.1 to 10% by weight with respect to the total weight of the rubber mold release agent of the present invention. , Preferably 0.1-7 wt%, more preferably 0.1-5 wt%
It is.

Furthermore, examples of the other components include pastes such as polyvinyl alcohol, methyl cellulose, and carboxymethyl cellulose, water, various antifoaming agents, and various preservatives.

[2. Second release agent for rubber]
As described above, the second release agent for rubber of the present invention is a release agent for rubber that contains inorganic powder and is used by adhering to the rubber surface, and further contains mineral oil. . The second release agent for rubber according to the present invention contains the mineral oil, so that the adhesion to the rubber surface is high, and the release property (
Good adhesion resistance). The reason for this is not necessarily clear, but for example, by mixing a hydrophobic mineral oil with a hydrophilic inorganic powder, the rubber surface (
It is presumed that the wettability to the hydrophobic surface is improved. That is, by improving the wettability, it is presumed that the adhesive property (adsorbability) of the rubber release agent to the rubber surface is enhanced, and as a result, various performances such as releasability (adhesion property) are improved. However, these assumptions do not limit the present invention.

Since the second release agent for rubber of the present invention contains mineral oil, the adhesion to the rubber surface is good without increasing the viscosity of the aqueous dispersion with a thickener or the like. For this reason, the second release agent for rubber of the present invention is easy to use because there is no poor drying due to the viscosity of the aqueous dispersion being too high, difficulty in controlling the concentration of the aqueous dispersion, and the like. .

In the second release agent for rubber of the present invention, as described above, the inorganic powder is, for example,
Bentonite, clay, talc, mica, alkaline earth metal carbonate and the like can be mentioned. Examples of the alkaline earth metal carbonate include calcium carbonate and magnesium carbonate.

In the second release agent for rubber according to the present invention, the inorganic powder is not particularly limited, but preferably contains a water-swellable inorganic powder as described above. The water-swellable inorganic powder can impart, for example, improved adhesion amount and dispersion stability to a rubber release agent. The type of the water-swellable inorganic powder, the content of the water-swellable inorganic powder in the second rubber release agent of the present invention, and the like are not particularly limited. For example, for the first rubber of the present invention Same as mold release agent.

In the second release agent for rubber of the present invention, as described above, it is preferable that the inorganic powder contains finely divided inorganic powder. The fine inorganic powder is not particularly limited, and examples thereof include bentonite, clay, talc, and mica. Moreover, although the average particle diameter of the said fine powder inorganic powder is not specifically limited, For example, 0.1-100 micrometers, Preferably it is 0.1-50 micrometers, More preferably, it is 0.1-10 micrometers or less. In the case where the first release agent for rubber of the present invention contains finely divided inorganic powder, the content of the finely divided inorganic powder with respect to the inorganic powder is preferably 30 to 1.
00% by weight, more preferably 50-100% by weight, still more preferably 70-100% by weight
It is. In the second rubber mold release agent of the present invention, the “average particle diameter” of the fine inorganic powder is the same as that of the first rubber mold release agent of the present invention unless otherwise specified. The weight average particle diameter measured using the method. The average particle size of the fine powder inorganic powder can be measured by, for example, a particle size distribution measuring apparatus, more specifically, for example, JIS Z 8825-1 as in the first release agent for rubber of the present invention. It can be measured by (Particle Diameter Decomposition-Laser Diffraction Method). However, this measurement method is an example, and the present invention is not limited to this measurement method.

The second rubber mold release agent of the present invention may or may not contain other components than the inorganic powder and the mineral oil. Although it does not specifically limit as said other component, For example, the said surfactant, the said fatty acid salt, and the said polyhydric alcohol are mentioned.
Although the kind and content rate are not specifically limited, For example, it is the same as that of the said 1st release agent for rubber | gum of the said invention. Examples of the other components include water, various antifoaming agents, pastes, various preservatives, and the like, similar to the first release agent for rubber of the present invention.

The method for producing the release agent for rubber of the present invention is not particularly limited, and may be the same as that of a general release agent for rubber, for example. Specifically, for example, in the method for producing a rubber release agent of the present invention, each component constituting the rubber mold release agent of the present invention may be mixed. The mixing method is not particularly limited, but may be mixed while being pulverized, if necessary, using a machine or the like. The machine used for mixing is not particularly limited. More specifically, the method for producing the release agent for rubber according to the present invention includes, for example,
You may carry out according to the below-mentioned Example.

Further, the method of using the release agent for rubber of the present invention is not particularly limited, but from the viewpoint of usability,
It is preferably used after being dispersed in water and used as the rubber release agent aqueous dispersion of the present invention.

[3. Rubber release agent aqueous dispersion]
Next, the rubber release agent aqueous dispersion of the present invention will be described.

As described above, the rubber release agent aqueous dispersion of the present invention is a rubber release agent aqueous dispersion in which the rubber release agent of the present invention is dispersed in water.

The method for producing (preparing) the rubber release agent aqueous dispersion of the present invention is not particularly limited. For example, the rubber release agent of the present invention may be mixed and dispersed in water. In the rubber release agent aqueous dispersion of the present invention, the concentration of the rubber release agent of the present invention is not particularly limited.
-15 wt%, preferably 0.5-10 wt%, more preferably 0.5-5 wt%. The method of using the rubber release agent aqueous dispersion of the present invention is not particularly limited, and may be the same as, for example, a general rubber release agent aqueous dispersion. Specifically, for example, the rubber release agent aqueous dispersion of the present invention may be applied to an unvulcanized rubber on the rubber surface or the like by dipping, showering, spraying or the like.

[4. Rubber and rubber production method]
About the rubber | gum of this invention and the manufacturing method of rubber | gum, it is as above-mentioned. These are also not particularly limited. For example, instead of a general rubber release agent or a general rubber release agent aqueous dispersion, the rubber release agent of the present invention or the rubber of the present invention is used. Except for using an aqueous release agent dispersion, it may be the same as a general rubber or rubber production method. As mentioned above,
In the rubber and the rubber production method of the present invention, the rubber is not particularly limited, and any rubber may be used, but unvulcanized rubber is preferable. Alternatively, the rubber of the present invention is, for example, subjected to a release treatment by attaching the rubber release agent of the present invention to the surface of the unvulcanized rubber (for example, by dipping, coating, etc.)
Furthermore, it is also preferable that the rubber is produced by a method of vulcanizing the unvulcanized rubber (a method for producing a vulcanized rubber). The release treatment may be performed, for example, by attaching the rubber release agent aqueous dispersion of the present invention to the surface of the unvulcanized rubber and volatilizing water.

Examples of the present invention will be described below. The present invention is not limited to these examples.

In the following examples, the components described in Table 1 below were used as the components of the rubber release agent unless otherwise specified. Bentonite used in the following examples ("Sun bentonite KA-1" in Table 1 below is a water-swellable bentonite. In the following examples, the average particle size of the inorganic powder is determined by laser diffraction scattering method. The weight average particle diameter measured by JIS Z 88
It was measured by 25-1 (Particle size resolving-laser diffraction method). Further, in the following Examples, when simply described as “surfactant”, unless otherwise specified, surfactant A and surfactant B described in Table 1 below are referred to as surfactant A: surfactant. The mixture was used at a mass ratio of B = 3: 1.

In the following examples, the release treatment of the rubber sheet and the evaluation of various properties of the release agent for rubber were performed according to the following methods unless otherwise specified.

[Rubber sheet release treatment method]
An unvulcanized rubber sheet (length 15 cm, width 6 cm, thickness 5 mm) is heated to 100 ° C., immersed in an aqueous dispersion (45 ° C.) obtained by adding a rubber release agent to water, and immediately pulled up. It was.

[Drying]
During the mold release treatment of the unvulcanized rubber sheet, the time from when the unvulcanized rubber sheet is pulled up until the portion other than the lower portion (the portion from the lower end to a width of 0.5 cm) is dried is visually measured. did. The lower part of the unvulcanized rubber sheet (the part from the lower end to the width of 0.5 cm) was ignored because it was difficult to dry because of liquid pooling.

In the release-treated unvulcanized rubber sheet, the wetted area (%) in the portion other than the lower portion (the portion from the lower end to the width of 0.5 cm) was visually confirmed. The larger the wet area (%), the better the wettability, and ideally the wet area is 100%. The lower part of the unvulcanized rubber sheet (the part from the lower end to the width of 0.5 cm) was ignored because a liquid pool could be formed.

[Adhesion to rubber]
The mold release treatment was performed on the unvulcanized rubber sheet (length 15 cm, width 6 cm, thickness 5 mm) whose initial weight was measured in advance and completely dried. The weight of the unvulcanized rubber sheet after drying was measured, and the numerical value obtained by converting the difference weight obtained by subtracting the initial weight from the weight after drying per 100 cm ² area was defined as the adhesion amount (mg / 100 cm ² ). In addition, since the surface area of the unvulcanized rubber sheet is 201 cm ² , the adhesion amount (mg / 100 cm ² ) is expressed by the following formula (A)
It is represented by

(Amount of deposition (mg / 100 cm ² )) = {(weight after treatment (mg)) − (initial weight (mg))}
/ 201 × 100 (A)

The said adhesion amount evaluated 30-50 mg / 100cm < ² > as the optimal (adhesion evaluation "(circle)" in the below-mentioned Table 2 and 3). If the amount of adhesion is large, the rubber adhesion tends to be good, but if the amount of adhesion is too large, the rubber adhesion is hardly improved and the drying property is deteriorated.

[Rubber adhesion]
As described above, two unvulcanized rubber sheets that had been subjected to mold release treatment and dried were superposed and pressure-bonded in a constant temperature bath at 60 ° C. for 24 hours under a load of 1 t / m ² . Then air-cooled to room temperature, 30cm
/ Min. The peel resistance (N / cm) was measured. The smaller the peel resistance, the better the adhesion resistance.

[Example 1: First release agent for rubber of the present invention]
[Example 1-1]
90 parts of bentonite, 4 parts of a surfactant as a wetting agent for rubber, and 2 parts of sodium carbonate as a pH buffering agent were blended. Furthermore, 0.05% of stearic acid was added to the treatment liquid as an acid expected to be mixed in the treatment liquid. In this way, a release agent for rubber of this example was obtained.

[Example 1-2]
The mixed stearic acid assumed in Example 1-1 was changed to 0.1% and added. In this way
A release agent for rubber of this example was obtained.

[Example 1-3]
90 parts of bentonite of Example 1-1 were changed to 70 parts of bentonite and 20 parts of clay and mixed. In this way, a release agent for rubber of this example was obtained.

[Example 1-4]
The total amount of sodium carbonate of Example 1-3 was changed to dipotassium adipate, and 4 parts were blended.
In this way, a release agent for rubber of this example was obtained.

[Example 1-5]
The clay of Example 1-3 was changed to talc and blended. In this way, a release agent for rubber of this example was obtained.

[Example 1-6]
5 parts of mineral oil (paraffinic) was further added to the blending components of Example 1-2 and blended. In this way, a release agent for rubber of this example was obtained.

[Example 1-7]
Further, 5 parts of mineral oil (naphthene) was added to the blending components of Example 1-2 and blended.
In this way, a release agent for rubber of this example was obtained.

[Comparative Example 1-1]
All of the sodium carbonate of Example 1-1 was deleted and blended.

[Comparative Example 1-2]
The whole amount of sodium carbonate of Example 1-2 was deleted and blended.

[Comparative Example 1-3]
The total amount of sodium carbonate of Example 1-3 was deleted and blended.

[Comparative Example 1-4]
The whole amount of sodium carbonate of Example 1-5 was deleted and blended.

[Rubber sheet release treatment and evaluation of rubber release agents]
For the rubber release agents (anti-adhesives) of Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-4, 2 wt% aqueous dispersions (treatment liquids) were prepared. Using this aqueous dispersion (treatment liquid), the unvulcanized rubber sheet was subjected to mold release treatment by the above method. And dryness, wettability to rubber,
The adhesion to rubber and the release property (adhesion property) of the rubber were evaluated by the above methods. Table 2 below
Shows the results. In addition, in the releasability (adhesion property) of rubber, the numerical value (N / cm) is an index of the magnitude of force required to peel off rubbers. That is, the smaller this value is, the easier it is to peel off rubbers and the higher the releasability (adhesiveness). As shown in Table 2, the rubber release agents of the examples all have adhesion to rubber (adhesion amount to rubber surface).
As a result, the release property (adhesion property) of the rubber was high. On the other hand, in the comparative example, the adhesion to rubber (the amount of adhesion to the rubber surface) was lower than that in the example, and as a result, the release property (adhesion) of the rubber was low.

[Example 2: Second rubber mold release agent of the present invention]
[Example 2-1]
90 parts of bentonite, 4 parts of surfactant as a wetting agent for rubber, and 5 parts of mineral oil (paraffin type) as an adhesion control agent were blended. In this way, a release agent for rubber of this example was obtained.

[Example 2-2]
The mineral oil of Example 2-1 was changed from paraffinic to naphthenic and blended. In this way, a release agent for rubber of this example was obtained.

[Example 2-3]
90 parts of bentonite of Example 2-1 was changed to 70 parts of bentonite and 20 parts of clay and blended. In this way, a release agent for rubber of this example was obtained.

[Example 2-4]
The clay of Example 2-3 was changed to talc and blended. In this way, a release agent for rubber of this example was obtained.

[Example 2-5]
The clay of Example 2-3 was changed to calcium carbonate and blended. In this way, a release agent for rubber of this example was obtained.

[Example 2-6]
The blending amount of the mineral oil (paraffinic) in Example 2-1 was changed from 5 parts to 1 part and blended. In this way, a release agent for rubber of this example was obtained.

[Example 2-7]
The amount of the mineral oil (paraffinic) in Example 2-1 was changed from 5 parts to 20 parts, and the amount of the surfactant was changed from 4 parts to 16 parts. In this way, a release agent for rubber of this example was obtained.

[Comparative Example 2-1]
All of the mineral oil of Example 2-1 was deleted and blended.

[Comparative Example 2-2]
The whole amount of the mineral oil of Example 2-1 was deleted, and 2 parts of CMC (thickener) was blended.

[Comparative Example 2-3]
90 parts of bentonite of Comparative Example 2-2 was changed to 70 parts of bentonite and 20 parts of clay and mixed.

[Comparative Example 2-4]
The clay of Comparative Example 2-3 was mixed with the total amount of talc.

[Comparative Example 2-5]
The clay of Comparative Example 2-3 was changed to calcium carbonate and blended.

[Comparative Example 2-6]
The total amount of CMC in Comparative Example 2-5 was changed to sodium polyacrylate and blended.

About the rubber mold release agent (anti-adhesive agent) of Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-6, a 2 wt% aqueous dispersion (treatment liquid) was prepared. Using this aqueous dispersion (treatment liquid), the unvulcanized rubber sheet was subjected to mold release treatment by the above method. And dryness, wettability to rubber,
The adhesion to rubber and the release property (adhesion property) of the rubber were evaluated by the above methods. Table 3 below
Shows the results. As shown in Table 3, the rubber release agents of the examples are all dry,
It was excellent in all of the adhesion to rubber (the amount of adhesion to the rubber surface) and the release property of the rubber (adhesion resistance). On the other hand, in Comparative Example 2-1, the adhesion to rubber (the amount of adhesion to the rubber surface) is low,
As a result, the releasability (adhesion resistance) of the rubber was low. On the other hand, in Comparative Examples 2-2 to 2-6, although the adhesion to rubber (adhesion amount to the rubber surface) and the release property (adhesion property) of rubber are high, the drying property is poor (the drying time is long). ), Work efficiency was extremely inferior.

As described above, according to the present invention, a rubber release agent excellent in both usability and releasability, a rubber release agent water dispersion using the same, a rubber, and a method for producing rubber are provided. Can be provided. The rubber mold release agent of the present invention and the rubber mold release agent aqueous dispersion of the present invention using the rubber release agent are particularly suitable as an adhesion preventing agent for unvulcanized rubber, but are not limited to this application. You may use for the mold release of rubber.

Claims (12)

A rubber mold release agent used is adhered to the rubber surface,
The rubber release agent comprises an inorganic powder and a pH buffer,
The pH buffer is at least one of carbonate and dibasic acid salt;
The inorganic powder is an inorganic powder other than the pH buffer;
A rubber mold release agent characterized in that the pH of the dispersion liquid is more than 8.0 and 10.0 or less when 2.0 g of the rubber mold release agent is dispersed in 100 g of water.   The rubber release agent according to claim 1, wherein the pH of the aqueous dispersion is 9.0 or more.   The rubber release agent according to claim 1 or 2, wherein the pH buffer is sodium carbonate.   Furthermore, the mold release agent for rubber | gum as described in any one of Claim 1 to 3 containing mineral oil.   The rubber mold release agent according to claim 4, wherein the mineral oil contains at least one of paraffinic oil and naphthenic oil. Wherein the inorganic powder is seen containing a water-swellable inorganic powder, the water-swellable inorganic powder content is, based on the total weight of the rubber releasing agent of claims 1 to 5 from 10 to 90 wt% The mold release agent for rubber | gum as described in any one.   The rubber mold release agent according to any one of claims 1 to 6, wherein the inorganic powder contains bentonite.   The mold release agent for rubber according to claim 7, wherein the inorganic powder further contains at least one kind of inorganic powder selected from the group consisting of clay, talc, mica, and alkaline earth metal carbonate.   Furthermore, the mold release agent for rubber | gum as described in any one of Claim 1 to 8 containing surfactant.   A rubber release agent aqueous dispersion in which the rubber release agent according to any one of claims 1 to 9 is dispersed in water. Release-treated rubber,
A rubber characterized in that the rubber release agent according to any one of claims 1 to 9 is adhered to a surface of a rubber that has not been subjected to a release treatment, and the release treatment is performed.   The mold release processing process of attaching the rubber mold release agent water dispersion according to claim 10 to the surface of the rubber which has not been subjected to the mold release treatment and further releasing the water by volatilizing water. Of manufacturing rubber.