JPH03100031A - Rubber additive - Google Patents

Abstract

PURPOSE:To reduce the scattering, improve the flowability and dispersibility, and facilitate mixing with rubber by mixing a rubber additive such as a powdered inorg. vulcanization accelerator aid, an acid acceptor, or a dehydrating agent with a liq. rubber, a plasticizer or an extender oil. CONSTITUTION:100 pts.wt. rubber additive (selected from the group consisting of a powdered inorg. vulcanization accelerator aid, an acid acceptor, and a dehydrating agent; e.g. ZnO or MgO) is mixed with 3-100 pts.wt. treating agent [selected from the group consisting of a liq. rubber such as a liq. acrylonitrile- butadiene rubber and/or a polyester plasticizer (with a viscosity of 1000cP or higher at 25 deg.C), a polyether plasticizer, and a synthetic hydrocarbon extender oil (e.g. ethylene-alpha-olefin co-oligomer)] at a temp. higher than the softening point of the treating agent, thus giving a rubber additive.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an additive for rubber, and more particularly to a vulcanization accelerator, an acid acceptor, and a water absorbing agent for inorganic rubber.

[Prior art] Rubber vulcanization accelerators include organic fatty acids such as stearic acid, amines, diethylene glycol, etc., and inorganic vulcanization accelerators such as zinc white, activated zinc white, and composite zinc white. , composite active zinc white, basic zinc carbonate, magnesium oxide, calcium hydroxide, etc. are used, and halogen-containing rubbers such as chloroprene rubber, fluororubber,
For chlorosulfonated polyethylene, etc., acid acceptors include zinc white, activated zinc white, composite zinc white, composite active zinc white, basic zinc carbonate, magnesium oxide, magnesium hydroxide,
Inorganic powders such as lead monoxide, red lead, basic lead carbonate, calcium oxide, calcium hydroxide, and hydrotalcites are used, and they are also used to prevent bubbles caused by water in the rubber during the vulcanization process. Powdered calcium oxide is used as a liquid medicine.

However, since the above-mentioned inorganic vulcanization accelerators, acid acceptors, and water-absorbing agents are fine powders, they are difficult to weigh, roll, banbury, and kneader.
Not only do they scatter during the kneading process and have a negative impact on the human body of the worker, worsen the work environment, and have poor dispersion, but they also reduce the cost of shortening the kneading time as part of the recent rationalization of the cross-mixing process. There is a strong demand for down, but it has poor dispersibility during roll kneading, and it takes time and effort to sweep up the powder that falls on the roll pan, collect it, and add it again.
Some powders such as magnesium oxide have the disadvantage that they stick to the back roll during roll kneading, resulting in a long kneading time.

[Problems to be Solved by the Invention] Therefore, the above-mentioned powdered inorganic vulcanization accelerator, acid acceptor,
Products in granular and other shapes are being provided to the rubber industry to improve defects such as the scattering of water absorbing agents.

However, dry granular products that have been granulated using only water as a binder by transfer granulation, extrusion granulation, compression granulation, etc. can improve powder defects such as scattering and fluidity in automatic weighing. The hardness and strength of the particles are required so that they do not break during transportation or other handling, so shear stress caused by cross-rolling in low-viscosity rubber may cause poor dispersion without breaking down to the original powder form. Furthermore, the adhesion to the rubber compound is insufficient, the biting is slow, and it is not sufficient to improve the drawbacks of falling onto the roll plate.

In addition, wet powder or granular products treated with mineral oil or plasticizer as a binder can reduce scattering and improve the dispersibility of the granular products described above, but they have weak adhesiveness and are difficult to adhere to rubber compounds. It is not sufficient to improve the defects of the powder because it slips on the roll, takes time to diffuse into the compound, and some of it also falls on the roll plate.

In addition, granular products treated with rubber vulcanization aids such as higher fatty acids, their esters, and metal salts as binders, ethylene-vinyl acetate copolymers alone or in combination with rubber, and plate-like products treated as masterbatches with rubber. Although it has been put into practical use in some areas, it is insufficient to improve its drawbacks, such as poor adhesion to rubber compounds and slow biting, as well as falling into roll pans, as with general granular products. Furthermore, the plate-shaped masterbatch requires additional heating time during kneading.

The present invention has been made to solve the above problems,
Its purpose is to improve the dispersibility, fluidity, roll workability, and dispersibility of rubber additives such as powdered inorganic vulcanization accelerators, acid acceptors, and water-absorbing agents, as well as to improve conventional proposals and put them into practical use. In addition to improving the dispersibility of the granular products mentioned above, the most important feature of the present invention is that the rubber compound can be easily penetrated into the rubber compound by cross-wires such as rolls and banburys, and the inner part of the compound can be It is an object of the present invention to provide a rubber additive that diffuses quickly into the rubber plate, does not fall onto the roll plate, and can shorten the kneading time.

[Means for Solving the Problems] That is, the present invention provides a rubber additive 1 selected from the group consisting of a vulcanization accelerator for powdered inorganic rubber, an acid acceptor, and a water absorbing agent.
00 parts by weight, a total amount of 3 to 100 parts of one or more selected from the group consisting of liquid rubber and/or polyester plasticizers, polyether plasticizers, and hydrocarbon synthetic extension oils as a processing agent. The present invention relates to a rubber additive characterized in that parts by weight are mixed at a temperature equal to or higher than the softening point of the processing agent used.

[Function] The rubber additives used in the present invention include powdered inorganic vulcanization accelerators, acid acceptors, water absorbing agents, etc., and the powdered French method generally used for rubber. brought back by
No. 1, No. 2, No. 3 zinc white, No. 1, No. 2 zinc white according to American method, activated zinc white, composite zinc white, composite active zinc white, basic zinc carbonate, magnesium oxide, magnesium hydroxide, lead monoxide. , red lead, basic lead carbonate, calcium oxide, calcium hydroxide, hydrotalcites, and mixtures thereof.

Further, as the processing agent, liquid rubber, polyester plasticizer, polyether plasticizer, hydrocarbon synthetic extender oil, etc. can be used.

The processing agent is liquid rubber alone or polyester plasticizer,
One or more components selected from the group consisting of a polyether plasticizer and a hydrocarbon synthetic extender oil, or the liquid rubber and a polyester plasticizer, a polyether plasticizer, and a hydrocarbon synthetic extender oil. It is also possible to use one type or a combination of two or more types of components selected from the group consisting of.

Liquid rubbers that can be used in the present invention include those that have high viscosity at room temperature, such as liquid acrylonitrile-butadiene rubber, liquid imprene rubber, liquid butadiene rubber, liquid chloroprene rubber, and liquid polysulfide. Note that these components can be used alone or in combination of two or more.

Polyester plasticizers that can be used in the present invention include dibasic acids selected from the group consisting of zebacic acid, adipic acid, azelaic acid, and phthalic acid, monoethylene glycol, diethylene glycol, triethylene glycol, monopropylene glycol, and Examples include polyesters of dihydric alcohols selected from the group consisting of dipropylene glycol, which have a viscosity of 1000 centipoise or more at 25°C. Note that these components can be used alone or in combination of two or more.

Polyether plasticizers that can be used in the present invention have a viscosity of 1000 centipoise or more at 25°C;
For example, Bayer AG's Vulcanol FH can be mentioned.

Examples of hydrocarbon synthetic extender oils include Lucant HC-10, 20, 40, 100, manufactured by Mitsui Petrochemical Industries, Ltd.
Hydrocarbon-based synthetic extender oils such as 150, 600, 2,000, and 3,000X, which are cooligomers of ethylene and α-olefin, having high viscosity at room temperature can be used.

The temperature at which the treatment agent is mixed with rubber additives such as powdered inorganic vulcanization accelerators, acid acceptors, and water-absorbing agents is such that the treatment agent softens or melts during mixing and forms an inorganic binder. Since it is necessary to bind the powder particles, a temperature above the softening point or melting point of the processing agent is required, but since the softening point of the processing agent is below room temperature, mixing at a temperature above room temperature is usually sufficient. It is.

The shape of the mixture can vary from wet powder to granular to paste products depending on the proportions of the inorganic powder, processing agent, and additives described below, but handling considerations such as scattering and weighing may vary. A fine granular product such as a wet powder or a granular product is preferable.

Furthermore, the rubber additive of the present invention is kneaded into a rubber compound using a roll, Nigoo mixer, Banbury mixer, etc.
- For boat fishing, the lowest cross wire temperature is 50 to 60 degrees Celsius in the case of roll cross wire, but even in that case, the processing agent softens and powdered inorganic vulcanization accelerator is added to the compound. In order for the particles of the acid acceptor and water absorbing agent to be dispersed, the treatment agent must have a softening point or melting point of the crosstalk temperature of 50°C or less,
In addition, in order to adhere well to the compound and bite into it well, the processing agent must be a substance that exhibits high adhesion to the compound when wires are crossed. At a softening point or melting point of 50°C or less, 50
Substances that exhibit high viscosity when crossed at ~60°C are the liquid rubbers, polyester plasticizers, and polyether plasticizers that are fluid at room temperature, and whose viscosity is 100°C at 25°C.
Plasticizers of 0 centipoise or higher and carbon-mono-arsenic synthetic extender oils can be used.

In addition, not only general plasticizers and softeners with a viscosity of 100 centipoise or less at 25°C, but also plasticizers and softeners with a viscosity of less than 1000 centipoise at 25°C can be used as processing agents. It has poor adhesion to rubber compounds, slips on the roll surface, takes time to diffuse into the compound, and also falls onto the roll surface, making it unsuitable as a processing agent.

In addition, inorganic vulcanization accelerators, acid acceptors, water-absorbing agents for powdered rubber, fillers for rubber such as ordinary light calcium carbonate, light calcium carbonate colloids, heavy calcium carbonate, clay, Talc, basic magnesium carbonate, calcium sulfate, barium sulfate, aluminum hydroxide, etc., rubber reinforcing agents such as carbon black, white carbon, etc., white pigments such as titanium dioxide, Nidobon, etc., -a
When powdered rubber compounding agents such as sulfur for rubber and vulcanization accelerators used for rubber are added and treated with the above-mentioned processing agent, the shape, hardness, size, and particle size distribution of the treated product are generated. It is possible to adjust the adhesion of the grain surface. The amount of these components added is approximately 0 to 100 parts by weight per 100 parts by weight of the inorganic vulcanization accelerator.

Similarly, rubber softeners such as petroleum process oil, paraffin, petroleum asphalt, vegetable oil softeners, sub-softeners, etc., and plasticizers such as phthalate esters, adipate esters, azelaic acid, etc. may be added to the above-mentioned processing agents as necessary. Ester, sebacate ester, maleate ester, fumarate ester, trimellitate ester, citric acid ester, phosphate ester, epoxy plasticizer, oleate ester, butyl stearate, chlorinated paraffin, etc., and tackifier for rubber. Agents such as coumaron/indene resin, p-tert-butylphenyl/acetylene resin, phenol/formaldehyde resin, terpene/phenol resin, polyterpene resin, xylene/formaldehyde resin, synthetic polyterpene resin, aromatic hydrocarbon resin, aliphatic carbonization Hydrogen resin, aliphatic cyclic hydrocarbon resin, polymerized special polyester, polybutyl atactic polypropylene,
Processing aids for rubber such as rosin derivatives, higher fatty acid esters of monohydric or polyhydric alcohols such as stearyl stearate, stearate ester of pentaerythritol, stearate ester of sorbitol, stearic acid, lauric acid, oleic acid, etc. higher fatty acid salt,
Calcium salts, magnesium salts, aluminum salts, etc.
Lubricants such as paraffin wax, low molecular weight polyethylene, low molecular weight polypropylene, ethylene/vinyl acetate copolymers, aliphatic amides, fatty alcohols, organic vulcanization accelerators such as higher fatty acids such as stearic acid, myristic acid, lauric acid, etc. By adding amines and the like, it is possible to adjust the shape, hardness, size, and particle size distribution of the particles, and the adhesion of the surface of the particles. The amount of these components added is 0 to 100 per 100 parts by weight of the processing agent.
The weight part is the weight height.

The amount of the treatment agent may be a rubber additive selected from the group consisting of a powdered inorganic vulcanization accelerator, an acid acceptor, and a water absorbing agent, or a rubber additive containing the filler, etc. The amount is 3 to 100 parts by weight, preferably 5 to 50 parts by weight, per 100 parts by weight of the agent. If the amount of the treatment agent is less than 3 parts by weight, the same drawbacks as powdered products such as scattering and dispersibility will not be improved, and if it exceeds 100 parts by weight, the treated material will pass through the granules and become block-like or clay-like. It becomes paste-like and is not suitable. In addition, the mixing method for the powdered inorganic vulcanization accelerator, acid acceptor, water-absorbing agent, and treatment agent may be as long as the temperature at the time of mixing is higher than the softening point or melting point before treatment, and the mixer model Although general rotary or stirring type mixers can be used, high-speed stirring fluid type mixers such as Henschel mixer,
Micro speed mixers are preferred for producing homogeneous wet powder products and uniform granular products.

[Example] The present invention will be further explained below with reference to Examples.

Example 1 Zinc white No. 1 according to French method [Mitsui Mining & Co., Ltd. 12]
．． High-speed agitation fluid mixing type mixer with internal volume of 101 [Mitsui Miike Kakoki Co., Ltd. Henschel mixer FMIO]
Type B], and add 0.3 of liquid acrylonitrile-butadiene rubber [Nipol 1312, Nippon Zeon Co., Ltd.] to it.
6kFI (18 parts by weight of processing agent per 100 parts by weight of Zinc White No. 1)
0.5 parts by weight) and mixed for 5 minutes at room temperature.
~20 mm granules were produced.

Example 2 Activated zinc white [Benjo Lime Industry Co., Ltd. NET8.2102]
1, 2, and light calcium carbonate ordinary product 0.4ky
and liquid isoprene rubber [Kuraray Co., Ltd.: Kurarun LIR]
-50] When 0.4 kg (25 parts by weight of the treatment agent per 100 parts by weight of the active zinc white and calcium carbonate content) is mixed in the same manner as in Example 1, a wet powder-like granule product of 0.15 to II is obtained. generated. This product had a finer and more uniform particle size than the product without the addition of calcium carbonate.

Example 3 Composite activated zinc white [Benjo Lime Industry Co., Ltd.: METΔ・
ZL50] 75g and polyester plasticizer U Adair Argus Chemical Co., Ltd. Niadeka Sizer PN-400, adipic acid polyester, viscosity (25°C) 9000-1
2000 centipoise] 25g<composite active zinc white 100
When 33.3 parts by weight of the processing agent was placed in a porcelain mortar and mixed at room temperature, granular products of 0.15 to 5 mm were produced.

Example 4 Magnesium oxide [Kyowa Kagaku Kogyo Co., Ltd.: Kyowa Mag 150] 1.0 kg and liquid chloroprene rubber [Denki Kagaku Kogyo Co., Ltd.; Denka LCR-H-050 0.5 kg]
kg (5 parts of treatment agent per 100 parts by weight of magnesium oxide)
0 parts by weight) is mixed in the same manner as in Example 1, it becomes 0.15 to 1
A 0 mm granular product was produced.

Example 5 Hydrotalcites [Kyowa Chemical Industry Co., Ltd.']: D
) IT4^, Hg<, s^L (OH) + zcL・
3.5H20] 75 g and liquid butadiene rubber [Idemitsu Petrochemical Co., Ltd.: Poly bd R-45IIT]
20y and stearic acid [NOF Corporation: tallow stearic acid pine] 5 g <33.3 parts by weight of liquid butadiene rubber as a processing agent and stearic acid, based on 100 parts by weight of hydrotalcite) in a porcelain mold. The mixture was placed in a mortar, heated to about 70°C, which is above the melting point of stearic acid, thoroughly mixed with a pestle, and then cooled to produce a granular product with a size of 0.15 to 5111I11. This product had harder grains and was less sticky than the product without the addition of stearic acid.

Example 6 Finely powdered calcium oxide [Benjo Lime Industry Co., Ltd. VEST
A PP] 200 g and hydrocarbon synthetic extension oil of cooligomer of ethylene and α-olefin [Mitsui Petrochemical Industries, Ltd. Nil-Cant IC-2000] 40 g<
A treatment agent (20 parts by weight per 100 parts by weight of calcium oxide) was placed in a porcelain mortar, mixed at room temperature, and then passed through a 5 mm wire gauze to give a granular product of 0.25 to 5 mm.

Example 7 Finely powdered calcium hydroxide [Benjo Lime Industry Co., Ltd.: N
ICC3000] 100 g and a polyether plasticizer [Bayer; Vulcanol FH] 5 g <5 parts by weight of treatment agent per 100 parts by weight of calcium hydroxide) are placed in a porcelain mortar and mixed at room temperature to produce a mixture of 0.15~ A wet powder-like granular product of IIm was produced.

In order to compare the treated rubber additives obtained in Examples 1 to 7 above with equivalent amounts of untreated products, the products of Examples 1 to 3 were treated with vulcanization accelerator as described below. Table 1 shows the formulation and test results of acrylonitrile-butadiene rubber (NBR) as an acid acceptor, and the formulation of chloroprene rubber (CR) as an acid acceptor with the products of Examples 4 and 5 as an acid acceptor. and the test results are shown in Table 2. Ethylene-propylene rubber (EPDM) containing the product of Example 6 as a water-absorbing agent
) and the test results are shown in Table 3, and Table 4 shows the compounding and test results for fluororubber in which the product of Example 7 was blended as an acid acceptor.

($1) NBR Compound N 1pol DN200 Stearic Acid White Carbon Bai Rika CC OP Actingu SL Sulfur Accelerator CZ 100 parts by weight 1 part by weight 30 parts by weight 30 parts by weight 5 parts by weight 1 part by weight 2 parts by weight 2I'' [Tsuta total 171 weight parts Part (* 2) CR compound neoprene W Stearic acid carbon black (Geast S) Accelerator 22 Zinc white No. 1 100 parts by weight 0.5 parts by weight 29 parts by weight 0.5 parts by weight 111 111 Total 135 parts by weight ( *3) EPDM Compound Nisprene 502 100 parts by weight Stearic acid 1 part by weight Zinc White No. 3 5 parts by weight FEF carbon 100 parts by weight Nantene oil 90 parts by weight Accelerator M O 15 parts by weight Accelerator TT
1.5 parts by weight accelerator PZ
1.5 parts by weight Needle 301 parts by weight Table 3 Table 4 (*4) Fluororubber compound Piton E-60C 100 parts by weight MT Carbon 30 parts by weight Kyowa Mag 150 3.11 Total 133 parts by weight [Effects of the invention] The present invention Treated rubber additives not only improve scattering, fluidity, and dispersibility, which are disadvantages of untreated powder products, but also have strong adhesion to compounds and are easy to bite into. It diffuses quickly into the interior and does not fall onto the roll pan, so there is no need to sweep up and collect the products that fall off the pan, which shortens the kneading time and improves productivity.

Claims (1)

[Scope of Claims] 1. 100 parts by weight of a rubber additive selected from the group consisting of a vulcanization accelerator for powdered inorganic rubber, an acid acceptor, and a water-absorbing agent, and a liquid rubber and/or as a processing agent. or one or more selected from the group consisting of polyester plasticizers, polyether plasticizers, and hydrocarbon synthetic extender oils in a total amount of 3 to 100 parts by weight or higher than the softening point of the processing agent used. A rubber additive characterized by being mixed at a temperature of . 2. The liquid rubber is one or more selected from the group consisting of liquid acrylonitrile-butadiene rubber, liquid isoprene rubber, liquid butadiene rubber, liquid chloroprene rubber, and liquid polysulfide, and the polyester plasticizer is sebacic acid or adipine. A polyester of a dibasic acid selected from the group consisting of azelaic acid, azelaic acid and phthalic acid and a dihydric alcohol selected from monoethylene glycol, diethylene glycol, triethylene glycol, monopropylene glycol and dipropylene glycol, the viscosity of which is is one or more polyesters having a viscosity of 1000 centipoise or more at 25°C, the polyether plasticizer has a viscosity of 1000 centipoise or more at 25°C, and the hydrocarbon synthetic extender oil has ethylene and α- The rubber additive according to claim 1, which is an olefin cooligomer. 3. Rubber additives selected from the group consisting of vulcanization accelerators, acid acceptors, and water-absorbing agents for powdered inorganic rubber include zinc white, activated zinc white, composite zinc white, basic zinc carbonate, and oxidized zinc white. A claim containing one or more components selected from the group consisting of magnesium, magnesium hydroxide, lead monoxide, red lead, basic lead carbonate, calcium oxide, calcium hydroxide, and hydrotalcites. The rubber additive according to item 1 or 2. 4. A rubber additive selected from the group consisting of a powdered inorganic rubber vulcanization accelerator, an acid acceptor, and a water absorbing agent is used as a rubber reinforcing agent, a white pigment, rubber sulfur, and a rubber vulcanization accelerator. The rubber additive according to any one of claims 1 to 3, which contains one or more components selected from the group consisting of additives. 5. The processing agent is one or two selected from the group consisting of rubber softeners, plasticizers, rubber tackifiers, rubber processing aids, lubricants, anti-aging agents, and organic vulcanization accelerators. The rubber additive according to any one of claims 1 to 4, which contains the above components.