SK501012013U1 - Rubber compositions and their use - Google Patents

Abstract

Described are rubber compositions comprising at least one rubber, triacetin and at least one filler selected from the group consisting of cellulose and / or cellulose derivatives. The compositions are suitable for the manufacture of vulcanizates and / or shaped articles, e.g. filling golf balls.

Description

RUBBER MIXTURE c Z / ch pCii’í.h'C.

TECHNICAL FIELD The present utility model relates to novel rubber compositions comprising cellulose and / or cellulose derivatives and triacetins, their use in the manufacture of rubber vulcanizates and rubber vulcanizates made therefrom, as well as a novel rubber additive.

Background of the Invention Rolling resistance of passenger car tires increases fuel consumption by 20 to 25 percent, in trucks up to about 30 percent. These values have prompted the European Commission to issue a regulation on the mandatory use of low rolling resistance tires for the automotive industry. For new cars, this obligation came into force in 2011. However, much of the market is made up of tires that will be used to replace the old and used ones. Since 2012, these have to be labeled with regard to their fuel economy, moisture resistance and rolling noise (driving noise). A system of classifications from A (best performance) to G (worst performance), similar to the already established system for classifying household appliances, is intended to provide consumers with greater clarity and essential assistance in purchasing new tires.

Since the European Union has been addressing the limit values for carbon dioxide in the flue gases of passenger cars, car manufacturers are looking for economic options to achieve a CO2 emission value of at most 130 g / km. They are largely concerned with the development of low rolling resistance tires, which do less work to change shape while driving, resulting in reduced fuel consumption. The harder the tire tread adheres to the road surface, the greater the energy loss due to abrasion and shape change. Consequently, the rubber compound intended for the tire tread must not be too soft.

At the same time, the requirements for resistance to moisture and noise during driving have been established so that the reduction in rolling resistance does not adversely affect other important properties. The first indication of shear retention on wet surfaces and rolling resistance is the tan δ loss coefficient. At the temperature

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0 ° C should be as high as possible (good skid retention on wet surfaces), at 60 to 70 ° C as low as possible (rolling resistance reduction).

There is, therefore, a great demand for improved rubber blending compositions which, when introduced into tire production, result in products with better properties, lower rolling resistance and noise and better adhesion to wet surfaces.

[0006] It is known that reinforcing fillers are added to the rubber mixtures during the preparation to improve the above properties. These may be carbon black, silicic acid, cellulose, or layered silicates.

Strengthening of elastomeric materials is generally understood to mean prolongation of service life, improvement of mechanical properties such as strength, abrasion resistance or rolling resistance, but also improvement of dynamic properties due to the interaction of the polymer network and the filler.

While these reinforcing fillers can often improve the properties of a product, they often have a negative effect on the processability of the rubber composition. For this reason, it is common to add to the rubber composition in addition to reinforcing reinforcing fillers also auxiliaries which are intended to improve the processability of the rubber composition. Thus, for example, fatty acid esters, fatty acid salts or softening oils may be used to improve the flowability of the rubber compositions. While these additives advantageously reduce the flowability of the rubber compositions (low Mooney viscosity), at the same time they increase the stress values at high extensibility (e.g. from 100% to 300%), respectively. the disadvantage is that they reduce the hardness of the vulcanizate, whereby the reinforcing effect of the filler fails on losses. However, too low a hardness or inflexibility of the vulcanizate will again adversely affect the properties of the product. If tires are made from vulcanizate of too low a hardness, the driving characteristics, especially in curves, will be unsatisfactory. Increasing the dosage of the reinforcing filler results in an increase in the hardness of the vulcanizate, but at the same time an increase in the viscosity of the mixture, which in turn adversely affects the processability of the vulcanizate. The same applies to the removal of the softening oil addition.

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628 / H — 01.02.2016 In the manufacture of vulcanizates intended for the tread of passenger car tires, the addition of silicic acid as a filler has proven to be successful. Silicic acid contributes to a good combination of properties, rolling resistance, slip retention ability on wet surfaces and friction wear.

In order to achieve the desired combination of properties, it is important that the silicic acid is well dispersed in the rubber preparation process and optimally bound to the rubber network during vulcanization. It is known in the art that organic sulfur-containing silanes (e.g. B.DE-A 24 47 614) or certain polysulfide silanes (e.g. EP-A1 0 0670 347 and US-A) are added to the rubber mixtures as reinforcing agents. -4,709,065). However, in the case of polysulfide silanes, relatively large amounts of these expensive additives are required to achieve acceptable processability.

It is already known from EP-A 1728821 that short fibers, e.g. 0.1-12 mm cellulose fibers. Various plasticizers with a molecular weight greater than 400 g / mol have been used to improve fiber dispersion.

EP-A 2072574 discloses a rubber structure with sulfur connected in a network comprising chemically modified, e.g. acetylated, microfibrous cellulose. This vulcanized rubber structure can be used to manufacture tires. It is clear from EP-A 2072574 that the addition of 1 to 50 parts by weight of acetylated cellulose relative to rubber led to a 6% increase in the tan value. One skilled in the art is to understand the deterioration of the rolling resistance, i.e. according to this document, when cellulose and its derivatives are used as a filler in rubber compositions, and if these compositions are used in the manufacture of tires, the result would be a deterioration of the rolling resistance.

It is generally known that rubber compositions may contain plasticizers. They interact with the rubber and lead to greater mobility of the chain segments, possibly to dissolution / release of crystalline ranges / regions. They cause the stress value, the hardness to decrease and the elasticity and the cold resistance to increase. There are oil softeners such as e.g. paraffinic, naphthenic and aromatic as well as synthetic emollients which:

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34628 / H — 01.02.2016 can be classified as aliphatic and aromatic esters, polyesters, phosphates, ethers and thioethers. Typical ester-based plasticizers are o.i. phthalic acid esters, aliphatic esters, phosphoric acid esters, adipic acid, trimellitic acid, citric acid esters, glycol esters.

The use of triacetin as a cellulose acetate plasticizer is described in GB 317443.

SUMMARY OF THE INVENTION The object of the present utility model was to provide improved methods for preparing filler-containing rubber, with good engineering properties, from which vulcanizates and the tire outer surfaces produced therefrom demonstrate reduced rolling resistance.

New rubber compositions have been found comprising cellulose and / or cellulose derivatives as filler and triacetin as plasticizer.

Surprisingly, the new rubber compositions have longer vulcanization jump times in combination with shorter vulcanization process times, and thus exhibit improved processability, without adversely affecting properties (hardness, elongation at break, tensile strength, friction wear) rubber which has been produced on their basis. Surprisingly, the vulcanizates produced from the new rubber compositions also have a better surface quality, which results in, for example, a better rolling resistance of the outer surface of the automobile tires thus produced.

In addition to expanding the spectrum of technical applications, economic and environmental aspects also play an increasingly important role. Not only the rising prices of raw materials, but also the increased sensitivity of modern society to the environmental aspects of production, consumption and material removal motivate industry to develop production processes in terms of raw material consumption, and bring products that are both environmentally and consumer friendly.

In this regard, another advantage of the rubber compositions according to the present utility model is that the cellulose contained therein and

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628 / H — 01.02.2016 triacetin can be obtained from renewable raw materials. Triacetin is produced from plant derived glycerin; cellulose from vegetable fibers.

The subject of the present utility is rubber compositions comprising at least one rubber, triacetin and at least one filler of the cellulose and / or cellulose derivatives series.

In the literature, the ratio of the other components to the rubber component in the rubber compounding compositions is normally given in relative quantity phr "parts per hundred parts rubber". This quantity marking is also given in the following.

The rubber compositions according to the present utility model generally comprise 0.1 to 100 phr of at least one cellulose and / or cellulose derivative, preferably 0.2 to 50 phr, in particular 0.3 to 30 phr.

The rubber compositions according to the present utility model generally comprise 0.1 to 80 phr of triacetin, preferably 0.2 to 60 phr and particularly preferably 0.5 to 45 phr, especially 5-30 phr.

Rubber The rubber composition according to the present utility model comprises at least one rubber. Preference is given to diene-based rubbers, in particular double-bonded rubbers, which contain practically no gel content and which are referred to as R-rubbers according to DIN / ISO 1629. These rubbers have double bonds on the backbone. For example, these rubber components are preferably used

NR: natural rubber SBR: styrene / butadiene rubber BR: polybutadiene rubber IR: polyisoprene SIBR: styrene / isoprene rubber

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NBR: nitrile rubber

IIR: butyl rubber (isobutene / isoprene rubber)

HNBR: hydrogenated nitrile rubber

SNBR: styrene / butadiene / acrylonitrile rubber

CR: polychloroprene

XSBR: carboxylated styrene / butadiene rubber

XNBR: carboxylated butadiene-acrylonitrile rubber

ENR: epoxidized natural rubber

ESBR: epoxidized styrene-butadiene rubber and mixtures thereof.

According to the present utility model, rubbers containing double bonds are those which, according to DIN / ISO 1629, are M-rubbers and, in addition to the saturated backbone, have double bonds on the side chains. These include, for example, EPDM.

According to the present utility model, the preferred rubbers are: NR, BR, SBR, IIR and EPDM.

NR, BR, styrene-diolefin rubbers and mixtures of these rubbers are particularly preferred.

Among styrene-diolefin (especially butadiene) rubbers, there are also abbreviated soluble SBR rubbers (or "solution rubbers"), abbreviated: L-SBR, and emulsion SBR rubbers, abbreviated as: E- SBR. L-SBR refers to rubbery polymers which are produced by a dissolution process based on vinylaromates and conjugated dienes. Suitable vinylaromatic monomers are styrene, o-, m- and p-methylstyrene, technical mixtures of methylstyrenes, p-tert-butylstyrene, p-methoxystyrene, vinylnaphthalene, divinylbenzene, trivinylbenzene and divinylnaphthalene. Styrene is preferred. The content of the polymerized vinylaromate is preferably 5 to 50 wt. %, more preferably 10 to 40 wt. %. Suitable diolefins are 1,3-butadiene, isoprene,

1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenyl-1,3-butadiene and 1,3-hexadiene.

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Preferably 1,3-butadiene and isoprene. The content of polymerized dienes is generally 50 to 95 wt. %, preferably 60 to 90 wt. %. The vinyl content of the polymerized diene is generally 10 to 90%, the 1,4-trans double bond content is 20 to 80%, and the 1,4-cis double bond content is complementary to the sum of the vinyl and double bond configurations 1. , 4-trans. The preferred vinyl content of L-SBR is> 20%.

Polymerized monomers and dienes of various configurations are usually represented statistically in polymers. Also, rubbers with a block-formed structure, referred to as integral rubber, fall within the definition of LSBR (A). L-SBR can be understood to include both linear and branched or end-modified rubbers.

In solution, the polymerized rubbers based on vinyl aromatics / diolefins are preferably characterized by Mooney values of from 20 to 150 Mooney units (ME), preferably in the range of 30 to 100 ME.

Particularly high molecular weight E-SBR species with Mooney values> 80 ME may contain oils in amounts of from 30 to 100 parts by weight relative to 100 parts by weight of rubber. Oil-free L-SBR rubbers exhibit glass transition temperatures in the range of -80 to +20 ° C as determined by differential thermoanalysis (DSC).

By E-SBR is meant rubbery polymers which are produced in an emulsion process based on vinyl aromatics, conjugated dienes and optionally other monomers. The vinylaromates are styrene, p-methylstyrene and alpha-methylstyrene, the dienes in particular butadiene and isoprene. Among the monomers, it is in particular acrylonitrile. The vinyl aromatic contents range from 10 to 60 wt. %, glass transition temperature from -50 to +20 ° C (determined by DSC) and Mooney values between 20 and 150 ME. In particular, high molecular weight E-SBR species having Mooney values > 80 ME may contain oils in amounts of from 30 to 100 parts by weight relative to 100 parts by weight of rubber. Oil-free L-SBR rubbers exhibit glass transition temperatures ranging from -80 to +20 ° C as determined by differential thermoanalysis (DSC).

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[0033] Polybutadiene (BR) mainly comprises two different types of polybutadiene types. In the first class, 1,4-cis dienes are at least 90% and are produced by the action of Ziegler-Natta transition metal catalysts. Catalyst systems based on titanium (Ti), nickel (Ni), cobalt (Co) and neodymium (Nd) are preferably used. The glass transition temperature of this polybutadiene is preferably < -90 ° C (determined by DSC).

The second type class of polybutadienes is produced with the participation of lithium (Li) catalysts and the vinyl content is in the range of 10 to 80%. The glass transition temperatures of these polybutadiene rubbers range from -90 to +20 ° C (determined by DSC).

According to the present utility model, the rubbers are preferably selected from the group of styrene / butadiene rubbers and polybutadiene, which rubbers can also be adjusted with petroleum oils.

Cellulose and cellulose derivatives The preparation of a rubber composition according to the present utility model comprises at least one cellulose and / or one cellulose derivative. The cellulose used is preferably commercial fibrous cellulose, or pulverulent or pulverulent, respectively. in the form of tablets (CAS-Nr.:9004-34-6). Particularly suitable cellulose derivatives are the following products of the reaction of cellulose with phenyl isocyanate, n-butyric anhydride, acetic anhydride, butyl isocyanate, stearyl chloride, stearyl isocyanate, butyric acid chloride. Preferred are cellulose derivatives resulting from the transesterification of cellulose with organic acids (carboxylic acids), e.g. with acetic acid. Of particular preference among cellulose derivatives is cellulose acetate (CAS-Nr .: 9004-35-7). Cellulose can be used alone or in any mixture with said cellulose derivatives. It is preferred to use cellulose acetate alone.

triacetin

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The preparation of the rubber composition according to the present utility model comprises at least one triacetin. Triacetin is also known as glycerol triacetate or 1,2,3-propanetriol triacetate (CAS-Nr .: 102-76-1, commercial product of Lanxess Deutschland GmbH).

Additives The preparation of the rubber compositions according to the present utility model may optionally contain other additives. Examples of suitable fillers, crosslinking systems, sulfur-based vulcanization accelerators, plasticizers, compounds that improve the technical processability of the compositions, anti-aging, UV and ozone protective agents, as well as other additives such as tackifiers, pigments, dyes, blowing agents, adhesion enhancers and adhesives and reversals.

The amount of additives used in the preparation of the rubber compositions according to the present utility model can vary considerably. Generally, the preparation of the rubber according to the present utility model comprises 0.1 to 100 phr, preferably 0.1 to 95 phr and particularly preferably 0.1 to 90 phr of one or more additives.

Fillers There are several possibilities for classifying fillers. It is expedient to divide according to the interaction with rubber, into reinforcing (active) and inactive fillers.

Inactive fillers:

Another suitable filler in the sense of the present utility model is in particular carbon black, in particular ldquor; carbon black ”, which are preferably produced in gas black, furnace black, lamp black and thermal black processes and are designated according to the new ASTM nomenclature (ASTM D 1765 and D 2516) as N 110, N 115, N 121, N 125 N 212 N 220 N 231 N 234

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N 242, N 293, N 299, S 315, N 326, N 330, N 332, N 339, N 343, N 347, N 351

N 375, N 472, N 539, N 550, N 582, N 630, N 642, N 650, N 660, N 683, N 754,

N 762, N 765, N 772, N 774, N 787, N 907, N 908, N 990, N 991, S 3, etc.

The soot used in accordance with the present utility model has a specific surface area determined by the BET method of preferably from 5 to 200 m ² / g.

In the preparation of the rubber compositions according to the present utility model, carbon black may be used in amounts of 0 to 120 phr, preferably in the range of 1 to 100 phr, particularly preferably in the range of 5 to 80 phr.

If the process for preparing the rubber according to the present utility model comprises carbon black, the total amount of oxygen-containing filler containing hydroxyl groups and carbon black preferably ranges from 20 to 160 phr, preferably 25 to 140 phr.

Other fillers that may optionally be used include:

- synthetic silicates, e.g. aluminum silicate, alkaline earth element silicates, such as magnesium or calcium silicate having a BET specific surface area of 20 to 400 m ² / gas with a primary particle diameter of 5 to 400 nm,

- natural silicates, e.g. kaolin and other naturally occurring silicas

- metal oxides, e.g. zinc oxide, calcium oxide, magnesium oxide, aluminum oxide,

- metal carbonates, e.g. calcium, magnesium, zinc carbonate,

- sulphates of metal, e.g. calcium sulfate, barium sulfate,

- metal hydroxides, e.g. aluminum and magnesium hydroxide,

- glass fibers and glass fiber products (plates, cords or glass microspheres).

Active fillers:

Compositions for the preparation of rubber within the meaning of the present utility model preferably comprise at least one additional filler from the series of oxygen-containing fillers containing hydroxyl groups. In the category of oxygen - containing fillers

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It is preferable to use a hydroxyl group filler containing hydroxyl groups and silicon, particularly preferably silicic acid. In hydrophilic silicas, hydroxyl groups are particularly on the surface.

For the purposes of the present utility model, silicic acid or quartz is used, particularly as pyrogenic silicic acid or as a reduced activity silicic acid, preferably with reduced activity silicic acid. The specific surface area of the silicas with reduced activity is 5 to 1000 m ² / g according to BET, preferably 20 to 400 m ² / g. They are prepared from water glass and inorganic acids, with sulfuric acid being preferred. The silicas may also be present as a mixture of oxides with other metal oxides, e.g. with oxides of aluminum, magnesium, calcium, barium, zinc, zirconium, titanium.

According to the present utility model, silicas with a specific surface area of 5 to 1000 m ² / g, particularly preferably 20 to 400 m ² / g, determined according to BET, are preferably used.

The rubber composition compositions according to the present utility model generally comprise 5 to 100 phr of at least one oxygen-containing hydroxyl-containing filler, preferably 30 to 100 phr and particularly preferably 50 to 90 phr, wherein the hydroxyl-containing oxygen-containing filler is preferably at least 30 %, but in particular at least 50% based on the total amount of fillers used.

The surface of the silicic acid can also be modified with silanes. Such a chemical reaction can be performed with all fillers having silanol groups on the surface. The silanol groups react relatively easily with silanes to form organic siloxanes. Modification of OH groups with silanes (mono-bifunctional organic silanes) improves interaction with non-polar rubbers.

Silanes useful for modifying the surface of silicas The compositions for preparing rubber in the sense of the present utility model may include one or more mono- and bifunctional organic silanes.

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Suitable silanes are, in particular, sulfur-containing organic silicon compounds. Particular preference is given to those sulfur-containing organic silicon compounds which contain one or more alkoxy-silyl groups, in particular one or more trialkoxysilyl groups.

Quite particularly preferred sulfur-containing organic silicon compounds are bis (tri-ethoxy-silyl-propyl-polysulfan; these products are, for example, under the trade names Silan Si 75 and Silan Si 69 (CAS-Nr .: 4037272-3) available Degussa.

Organic silicon compounds containing sulfur in amounts of 0.1 to 14 phr, in particular in amounts of 0.2 to 12, may be used in the rubber composition compositions of the present utility model.

In the case where the rubber compositions according to the present utility model comprise an oxygen-containing hydroxyl-containing filler, it is preferable to use at least one silane which ensures the bonding of the hydroxyl-containing oxygen-containing filler to the rubber network. These silanes are also referred to as enhancing additives. They are particularly suitable from the series of organic sulfur-containing silicon compounds. By way of example, bifunctional organosilanes with netting groups - vinyl or thio - may be mentioned. Preferably, at least one bis (triethoxysilyl-propyl) -tetrasulfide or bis (triethoxysilyl-propyl) disulfide has been used as the reinforcing additive for hydroxyl-containing oxygen-containing fillers in the preparation of the rubber according to the present utility model.

Netting System Compositions for preparing rubber in the sense of the present utility model may include one or more netting systems. In particular, sulfur or sulfur donors, such as dithiomorpholine (DTDM) or 2 (4-morpholine-dithio) benzothiazole (MBSS), are suitable. Sulfur and sulfur donors may be used in amounts of 0.1 to 15 phr, preferably 0.1 to 10 phr. Network forming systems may be used alone or in combination with vulcanization accelerators.

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Curing accelerators Suitable curing accelerators are, for example, mercaptobenzothiazole, sulfenamide, guanidine, thiuram disulfide, dithiocarbamates, thioureas, thiocarbonates as well as dithiophosphates and the like.

The vulcanization accelerators may be used in amounts of 0.1 to 15 phr, preferably 0.1 to 10 phr.

Compositions for preparing rubber in accordance with the present utility model include at least one vulcanization accelerator. Alternatively, several accelerators may be used in combination with conventional activators.

Reversible Anti-Reversal Compositions The rubber compositions of the present utility model may comprise one or more reversal anti-reversal agents, e.g. 1,6bis- (N, N-dibenzylthiocarbamoylditio) hexane (CAS-Nr .: 151900-44-6), 1,3-bis (3-methyl-2,5-dioxopyrrol-1-yl) methyl) benzene (CAS -Nr .: 119462-56-5) or hexamethylene-1,6-bis (thiosulfate) disodium dihydrate (CAS-Nr .: 5719-73-3). Particular preference is given to using 1,6-bis- (N, N-dibenzylthiocarbamoylditio) hexane. Said reversal agents may be used individually or in any mixture with each other; preferably in amounts of 0.1 to 20 phr with respect to the rubber.

Anti-Aging Agents When preparing the rubber composition of the present utility model, it is desirable to add one or more anti-aging agents, i. substances inhibiting the effect of heat and oxygen. Suitable are e.g. phenol-derived substances, alkylated phenols, styrene phenol, steric hindered phenols such as e.g. 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol (BHT), 2,6-di-tert-butyl-4-ethylphenol, steric hindered phenols containing ester functional groups, phenols with steric barriers containing thioether functional groups, 2,2-methylene

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628 / H — 01.02.2016 Bis- (4-methyl-6-tert-butylphenol) (BPH) as well as thiobisphenols with spherical obstacles.

If the coloring of the rubber is not of importance, amine-based anti-aging agents, e.g. mixtures of diaryl-phenylenediamines (DTPD), octylated diphenylamine (ODPA), phenyl-anaphthylamine (PAN), phenyl-p-naphthylamine (PBN), in particular phenylenediamine-based compounds. For example, N-isopropyl-N'-phenyl-p-phenylenediamine, N-1,3dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N-1,4-dimethylpentyl-N'-phenyl-phenylenediamine (7PPD), N, N'-bis-1,4- (1,4-dimethylpentyl) -β-phenylenediamine (77PD).

Other anti-aging agents include phosphoric acid derivatives, e.g. tris- (nonylphenyl) phosphite, polymerized 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), 2-mercaptobenzimidazole (MBI), zinc methylmercaptobenzimidazole (ZMMBI). Phosphites are commonly used in combination with phenolic anti-aging agents. For NBR rubbers vulcanized with peroxides, TMQ, MBI and MMBI were used. Said anti-aging agents may be added to the rubber compositions in the usual amounts, for example 0.1 to 5 phr, in the sense of the present utility model.

Antioxidants The ozone resistance of the rubber prepared according to the present utility model can be increased by known antioxidants, e.g. N1, 3-dimethylbutyl-N'-phenyl-p-phenylenediamine (6PPD), N-1,4-dimethylpentyl-N'phenyl-p-phenylenediamine (7PPD), N, N'-bis-1,4- (1 (4-dimethylpentyl) -p-phenylenediamine (77PD), enol ether or cyclic acetals. The antioxidants may be added to the rubber compositions prepared in accordance with the present utility model in amounts usually e.g. 0.1 to 5 phr.

Plasticizers Compositions for preparing the rubber of the present utility model may include conventional plasticizers such as petroleum oil and / or synthetic.

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628 / H — 01.02.2016 esters such as esters of violet acids, adipic acid, phosphoric acid, citric acid, benzoic acid, trimellitic acid or acetic acid. Amounts of 0.11 to 80 phr, preferably 0.2 to 60 phr, in particular 0.5 to 45 phr, were used.

Formulations Improving the Workability of Rubber Compositions The compositions for preparing the rubber of the present utility model may also include other conventional workability enhancers. These additives should be active between the rubber particles and counteract the frictional forces during mixing, plasticizing and shaping. The rubber composition prepared in accordance with the present utility model may contain all conventional plasticizers suitable for processing plastics in the usual amounts.

Other Additives Alternatively, other additives may be used in the preparation of the rubber composition of the present utility model, e.g. flame retardants, blowing agents, antistatic agents, biocides, petroleum oils, surface adhesion enhancers, dyes, pigments, waxes, resins, bulking agents, organic acids, vulcanization retardants, vulcanization activators, e.g. zinc oxide, stearic acid as well as zinc stearate, metal oxides, as well as other filler activators such as e.g. triethanolamine, trimethylolpropane, polyethylene glycol, hexanetriol, aliphatic trialkoxysilanes or others known in the rubber industry. They are commonly used in amounts of 1 to 50 phr.

Artificial (plastics) Other plastics may also be included in the rubber composition according to the present utility model, which act, for example, as polymer processing aids or as impact improvers. These plastics are of the group of homo- and copolymers based on ethylene, propylene, butadiene, styrene, vinyl acetate, vinyl chloride,

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628 / H — 01.02.2016 glycidyl acrylate, glycidyl methacrylate, acrylates and methacrylates with an alcohol component of a branched or unbranched Cr to C ₁₀ -alcohol. May be mentioned particularly polyacrylates with the same or different alcohol substituents from the group of C ₄ - to C alcohols, in particular butanol, hexanol, octanol and 2-ethylhexanol, polymethyl methacrylate, copolymers of methyl metakrylátbutylakrylátu copolymers, methyl methacrylate-butyl methacrylate copolymers, ethylene vinyl acetate, chlorinated polyethylene, copolymers of ethylene with propylene, copolymers of ethylene, propylene and dienes.

Multiple ingredients may be included in any combination.

Preference is given to rubber compositions comprising at least one rubber, 0.2 to 50 phr cellulose and / or cellulose acetate, 0.2 to 60 phr triacetin and 0 to 10 phr of at least one sulfur-based acceleration system and 0 to 95 phr of at least one additional, additional ingredient.

Preference is given in particular to compositions for the preparation of rubber comprising at least one rubber of the series of synthetic rubbers, 0.3 to 30 phr cellulose and / or 0.3 to 30 phr cellulose acetate, and 0.5 to 45 phr triacetin, 0 to 10 phr phr of at least one sulfur-based acceleration system of a series of sulfur / sulfenamide systems and 50 to 90 phr of at least one oxygen-containing hydroxyl-containing filler and 0.2 to 12 phr of at least one silane of a series of organic sulfur-containing silicon compounds.

Preference is given in particular to compositions for the preparation of rubber comprising at least one rubber of the series styrene-butadiene- and polybutadiene rubbers, 0.3 to 30 phr cellulose and / or 0.3 to 30 phr cellulose acetate and 0.5 to 45 triacetin; up to 10 phr of at least one sulfur-based acceleration system from the series of sulfur / sulfenamide systems, 50 to 90 phr of silicic acid having a specific surface area of 5 to 1000 m ² / g as determined by BET and 0.2 to 12 phr of at least one bis enhancer triethoxysilylpropyl) -tetrasulfide; and bis (triethoxysilylpropyl) disulfide.

The preparation of the rubber in the sense of the present utility model can be carried out by a known process in which, for example, the individual components and, optionally, other additives are mixed with one another. Mixing is carried out routinely

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628 / H — 01.02.2016 in the process of non-continuous mixing (on mixers and rollers) at a temperature of e.g. 80-150 ° C.

The cellulose and / or cellulose derivative and triacetin rubber components may be added individually or as a mixture in any mixing ratio and at each mixing stage during the mixing process.

[0074] Of the rubber compositions according to the present utility model, they can be subsequently used in a mixing apparatus at a temperature of e.g. 150 to 200 ° C, preferably at 130 to 180 ° C and optionally under a pressure of 1 to 100 bar, to produce rubber vulcanizates.

A further object of the utility model is to use a composition comprising at least one cellulose and / or a cellulose and triacetin derivative as a rubber additive.

The compositions useful according to the utility model comprise at least one cellulose and / or a cellulose derivative. Fiber cellulose (pure cellulose description, CAS-Nr .: 9004-34-6) was used. Suitable cellulose derivatives are, in particular, the following products of the reaction of cellulose with phenyl isocyanate, n-butyric anhydride, acetic anhydride, butyl isocyanate, stearyl chloride, stearyl isocyanate or butyric acid chloride.

Preference is given to cellulose derivatives which are obtained by esterifying cellulose with organic, carbonic acids, e.g. with acetic acid. Cellulose acetate (CAS-No .: 9004-35-7) is particularly preferred. Cellulose alone or in any mixture with said cellulose derivatives may be used.

The best usable composition according to the utility model is a mixture of cellulose acetate and triacetin.

The composition usable according to the utility model generally comprises 99 parts by weight to 1 part by weight of at least one cellulose and / or cellulose derivative and 1 to 99 parts by weight of triacetin, preferably a mixture consisting of 60 to 2 parts by weight of at least one cellulose and / or derivative cellulose and 40 to 98 parts by weight of triacetin, particularly preferably mixtures containing 50 to 3 parts by weight of cellulose and / or a cellulose derivative

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And 50 to 97 parts by weight of triacetin, particularly preferably 40 to 4 parts by weight of cellulose and / or cellulose derivative and 60 to 96 parts by weight of triacetin.

The composition usable according to the utility model is a suitable rubber additive. Suitable rubbers are those mentioned above as being conventional and preferred, and mixtures thereof. The addition of the inventive compositions useful as rubber additives can improve the technical processability during the rubber preparation. In particular, the addition prolonged the time of vulcanization, while reducing the duration of vulcanization, without adversely affecting the properties of the rubber vulcanizate thus produced (such as hardness, extensibility or elongation at break, tensile strength, friction wear).

The rubber vulcanizates are produced in a multi-stage blending process, wherein at least one cellulose and / or cellulose derivative and triacetin and at least one rubber are mixed in amounts indicated for these components generally or preferentially, optionally in the presence of one or more additives, e.g. . other fillers, anti-aging agents, anti-aging agents, antioxidants, plasticizers, and aids to facilitate processing at temperatures of 80-150 ° C in a mixing apparatus, e.g. in a mixer, roller and / or extruder, and vulcanized in the presence of at least one screening system and / or vulcanization accelerator at a temperature of 150 ° C to 250 ° C, preferably 130 to 180 ° C, optionally under a pressure of 1 to 100 bar.

Filled rubber vulcanizates are produced by mixing at a temperature of 80 to 150 ° C in a mixing apparatus, e.g. mix in at least one rubber, at least one cellulose and / or cellulose derivative and triacetin, at least one hydroxyl-containing oxygen-containing filler and at least one mono- or bifunctional organic silane, in the amounts specified for the mixer, roller and / or extruder in a multi-stage mixing process these components in general or preferably, optionally in the presence of one or more additives, such as e.g. other fillers, antiperspirants,

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628 / H — 01.02.2016 anti-aging agents, antioxidants, plasticizers and processability improvers, and vulcanized in the presence of at least one network-forming system and / or vulcanization accelerator at a temperature of 150 ° C to 250 ° C, preferably 130 to 180 ° C, optionally at a pressure of 1 to 100 bar.

In the manufacture of rubber vulcanizates according to the present utility model, it is preferred to connect the sulfur to the network with the aforementioned network forming systems.

According to the present utility model, the rubber additives and possibly other additives are added, in particular in the first part of the mixing process, at a batch temperature of 100 to 200 ° C, but they can be added later at lower temperatures (20 to 100 ° C). ° C) e.g. together with a sulfur-based netting additive and / or accelerator. Utility model additives can be added directly as a mixture consisting of cellulose and / or cellulose derivative and triacetin or as individual components.

The netting agent and / or the vulcanization accelerator is expediently not added in one mixing step at elevated temperatures, when it activates an oxygen-containing filler containing hydroxyl groups (e.g. silicic acid) by the action of organic sulfur-containing silicon compounds, as this would lead to to premature cure the mixture. The crosslinking additive and / or the vulcanization accelerator are therefore preferably worked after addition of sulfur-containing organic silicon compounds, preferably at temperatures below 100 ° C.

The production of rubber vulcanizates according to the present utility model can be carried out, for example, in the following mixing stages:

Stage 1 mixing:

[0087]

Put rubber (e.g. a mixture of SBR and BR) into the mixer and allow to stir for about 30 seconds.

Respectively. an oxygen - containing filler containing hydroxyl groups and silane is added to

PUV 50101-2013

628 / H — 01.02.2016 surface modification (eg two-thirds of silicic acid, two-thirds of silane, allowed to mix for about 60 seconds, and a third of silicic acid, one-third of silane added, allowed to mix for about 60 seconds).

A mixture of cellulose acetate and triacetin is added. carbon black, oil, anti-aging agent, zinc oxide as well as ozone-protecting waxes; the mixture is allowed to stir for about 60 seconds.

This mixing process can be carried out at temperatures of 20 to 200 ° C, preferably around 150 ° C.

2nd mixing stage:

Upon completion of the 1st mixing stage, the mixture is transferred to an attached roller where it is formed into a plate, strip or tablet and stored at room temperature for 24 hours.

The processing temperatures do not exceed 60 ° C.

3rd degree of mixing:

In the third mixing step, at a temperature of 140 to 170 ° C, preferably at 150 ° C, additional cleavage, e.g. in a mixer / batch mixer.

4th degree of mixing:

Addition of additives such as e.g. vulcanization accelerators and / or sulfur-containing netting additives, preferably on a roller at low temperatures (<80 ° C).

Aggregates suitable for the production of mixtures are known and include, for example, rollers, batch mixers or even mixing extruders.

A further object of the present utility model is the use of a rubber composition according to the utility model for the production of rubber vulcanizates,

PUV 50101-2013

628 / H — 01.02.2016 specially filled rubber vulcanizates and molded articles of rubber, in particular tires and prefabricated pneumatic products.

A further object of the present utility model is rubber vulcanizates and molded rubber articles which can be produced by vulcanization in a manner known from the preparation of rubber compositions within the meaning of the present utility model.

The rubber vulcanizates produced are suitable for the production of various tire precast products, in particular tire treads, lower treads, tire casing skeletons, sidewalls, reinforced sidewalls of roll-over tires, apex mixtures, etc., as well as the production of technical rubber products. e.g. shock absorber elements, roller / rolling machine linings, transporters, belts, spindles, gaskets, golf ball pads, shoe soles, etc. The mixtures are particularly suitable for the production of tire treads, protector lower parts, tire casings and apex mixtures. Tires resp. the tire parts also include, for example, the treads of summer, winter and all-year tires as well as passenger and truck tires.

Examples In the following, the utility model is explained in the examples, but is not limited thereto.

The components of the rubber preparation according to the present utility model:

1) Buna® VSL 5025-1 from Lanxess Deutschland GmbH

2) Buna® CB 24 from Lanxess Deutschland GmbH

3) Vulkasil S from Lanxess Deutschland GmbH

4) Tudalen 1849-1

5) Zinc Beloba Red Seal (Zinkweiss Rotsiegel) by Grillo Zinkoxid GmbH

6) Edenor C 18 98-100 from Cognis Deutschland GmbH

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628 / H-01.02.2016

7) 2,2,4-trimethyl-1,2-dihydroquinoline, polymerized (Vulkanox® HS / LG from Lanxess Deutschland GmbH)

8) N-1,3-dimethylbutyl-N‘-phenyl-p-phenylenediamine (Vulkanox® 4020 / LG from Lanxess Deutschland GmbH)

9) Antilux® 654 from RheinChemie GmbH

10) Bis (triethoxysilylpropyl) polysulfide (Si 69 from Degussa Huls AG)

11) Corax N 339 from Degussa Huls AG

12) Soluble sulfur (Solvay Barium Strontium 90/95 ° Chancel® ground sulfur)

13) N-cyclohexyl-2-benzthiazylsulfenamide (Vulkacit® CZ from Lanxess Deutschland GmbH)

14) Diphenylguanidine (Vulkacit® D / C from Lanxess Deutschland GmbH)

15) Cellulose acetate (CAS-Nr .: 9004-35-7) 4% by weight from Eastman and 96% by weight triacetin (CAS-Nr .: 102-76-

1) from Lanxess Deutschland GmbH

Production of rubber vulcanizates according to the present utility model The vulcanizates were produced according to the rubber recipes relating to Examples 1 and 2 as well as the Reference Example shown in Table 1. As shown below, the respective ingredients were mixed in a multi-stage mixing process (each). Examples 1 and 2 as well as Reference Example), and the mixtures were subsequently cured at 170 ° C.

Stage 1 mixing:

[0100]

The mixer charge (BUNA® CB 24 and BUNA® VSL 5025-1) was allowed to stir for about 30 seconds.

Add two thirds of VULKASIL® S, two thirds of SI® 69, mixing about 60

PUV 50101-2013

34628 / H — 01.02.2016 Seconds.

Add one third of VULKASIL® S, one third of SI® 69 as well as TUDALEN® 1849-1, stirring for about 60 seconds.

Addition of CORAX® N 339, EDENOR® C 18 98-100, Cellulose Acetate Triacetin Mixture, VULKANOX® 4020 / LG, VULKANOX® HS / LG, Zinc White Red Seal as well as ANTILUX® 654, Mix for about 60 seconds .

This mixing process was carried out at a temperature of 150 ° C.

2nd mixing stage:

Upon completion of the 1st stage of mixing, the mixture was passed to an attached roller and formed into a plate that was stored at room temperature for 24 hours.

The processing temperatures did not exceed 60 ° C.

3. Stirring stage:

In the 3rd mixing stage, further digestion in the kneader at 150 ° C followed.

4th degree of mixing:

Addition of additives: CHANCEL 90/95 ground sulfur, VULKACIT® CZ / C, VULKACIT® D / C to the rolling machine at temperatures not exceeding 80 ° C.

The prepared rubber mixtures and vulcanizates were subjected to the technical tests described in the following section. The measured values are also shown in Tab. First

Tests on prepared rubbers and vulcanizates:

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628 / H-01.02.2016

Mooney viscosity measurement:

The viscosity can be determined by the strength by which the rubbers (and mixtures of rubbers) resist their processing. In a parallel plate viscometer according to Mooney, the fluted disk is filled from above and below with the test substance and moved in a tempered chamber at a frequency of about 2 revolutions per minute. The force exerted on this is measured as torque and corresponds to the corresponding viscosity. As a rule, the sample is preheated to 100 ° C for one minute; The measurement, at a constant maintained temperature, takes an additional 4 minutes.

The viscosity is reported along with the respective test conditions, e.g. ML (1 + 4) 100 ° C (M = Mooney viscosity; L = wide, large, i.e. large, rotor; duration of preheating and measurement in minutes; temperature of measurement). The viscosity values of the prepared rubbers listed in Table 1 were measured using a Mooney shear disc viscometer.

The reaction of the blend to scorch ("Scorch") can also be measured by the same assay. In this patent, a temperature of 130 ° C was chosen. The rotor runs until the torque value rises to 5 Mooney units after the minimum has been exceeded relative to the minimum value (t5). The higher the value (in seconds), the slower the vulcanization starts (high Scorch values).

Rheometer (vulcameter) vulcanization time 170 ° C / t95;

The curing process on the moving die rheometer (MDR) and the relevant analytical data were obtained using an MDR 2000 rheometer from Monsanto according to ASTM D5289-95. The results of this test are collected in Tab.

Second

During vulcanization, the time at which 95% of the rubber was crosslinked at a selected temperature of 170 ° C was measured.

Determination of hardness (Shore A):

PUV 50101-2013

34628 / H — 01.02.2016 In order to determine the hardness of the rubber composition prepared in accordance with the present utility model, rubber layers coated on a 6 mm thick cylinder were made from the rubber composition made according to the formulas shown in Table 1. Samples with a diameter of 35 mm were cut from these layers and the hardness (Shore A) was measured with a digital tester manufactured by Zwick GmbH & KG, Olm.

Tear test:

The tear test serves directly to measure the elastomer load limits. The length of the specimen at rupture relative to the original length corresponds to the relative elongation at rupture. The force is also measured to reach certain elongation stages, mostly 50, 100, 200 and 300%, and is expressed as the value of stress (tensile strength at said 300% elongation or Module 300).

The measurement results are shown in Tab. First

Dynamic Damping Dynamic measurement processes were used to characterize the deformation reaction of elastomers exposed to periodic load changes. The externally applied voltage changes the conformation of the polymer chain.

In this measurement, the loss factor ian 5 is determined indirectly from the ratio of the state module G 'to the storage module G'.

Table 1

References. Example 1 Example 2 phr phr phr BUNA CB 24 30 30 30 BUNAVSL 5025-1 96 96 96 CORAX N 339 6.4 6.4 6.4 VULKASIL S 80 80 80 TUDALEN 1849-1 8 8 0

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628 / H-01.02.2016

References. Example 1 Example 2 phr phr phr EDENOR C 1898-100 1 1 1 Vulkanox 4020 / LG 1 1 1 Vulcanox HS / LG 1 1 1 Zinc Beloba Red seal 2.5 2.5 2.5 ANTILUX 654 1.5 1.5 1.5 SI 69 6.4 6.4 6.4 Ground sulfur 90/95 CHANCEL 1.5 1.5 1.5 VULKACIT CZ / C 1.5 1.5 1.5 VULCACIT D / C 2 2 2 Cellulose acetate with triacetin 10 20 Mooney viscosity (ML 1 + 4) DIN 53523 [Me] 91 66 66 Cure time according to ASTMD (MS-t5) 5289-95 with 1085 1582 1468 Vulcanization time (t95%) DIN 53529 with 1213 1091 940 Hardness DIN 53505 [Shore A] 70 70 69 Module 300 DIN 53504 MPa 16 14 12 ^Elongation K ^ri OIN 53504 rupture % 338 377 388 Tensile strength DIN 53504 MPa 18 19 16 Friction wear DIN 53516 mm ³ 85 89 94 tan δ (-1 ° C) indication of shear resistance on wet surfaces 0,458 0,416 0,399 Tan 5 (60 ° C) rolling resistance indication 0,147 0,142 0,123

As shown in the results of Example 1, the tan 5 at 60 ° C (rolling resistance indication) was reduced by the addition of an additive composed of a 10 phr cellulose acetate and triacetin utility pattern based on rubber. Simultaneously, the flowability (Mooney viscosity) decreased. In addition, the time of vulcanization start up as well as the relative elongation at rupture has been increased, and the duration of vulcanization has been reduced while maintaining good shear resistance in wet conditions.

PUV 50101-2013

628 / H — 01.02.2016 surface (> 0.380). If, as can be seen from the results of Example 2, the amounts of softening oil (TUDALEN 1849-1) are omitted, but the amount of cellulose acetate and triacetin used is further increased to 20 phr relative to the rubber, it turns out surprisingly that tan δ, can be greatly reduced without compromising other mechanical properties, such as e.g. elongation at break, tensile strength and hardness. Also in Example 2, it was possible to increase the cure time of the vulcanization, thereby increasing the safety of production as well as shortening the cure time.

Claims (15)

PROTECTION REQUIREMENTS CLAIMS 1. Rubber mixtures characterized in that they comprise at least one rubber, triacetin and at least one filler of the cellulose and / or cellulose derivatives series. Rubber mixtures according to claim 1, characterized in that they comprise 0.1 to 100 phr of at least one cellulose and / or cellulose derivative and 0.1 to 80 phr of triacetin. Rubber mixtures according to claims 1 and 2, characterized in that they comprise at least one rubber selected from the group of styrene-butadiene rubbers and polybutadiene rubbers. Rubber mixtures according to at least one of Claims 1 to 3, characterized in that they comprise cellulose acetate as the cellulose derivative. Rubber mixtures according to at least one of claims 1 to 4, characterized in that they comprise at least one further filler of a plurality of hydroxyl-containing oxygen-containing fillers. Rubber mixtures according to at least one of claims 1 to 5, characterized in that they comprise silicic acid having a specific surface area of 5 to 1000 m ² / g as further filler. Rubber mixtures according to at least one of claims 1 to 6, characterized in that they comprise at least one rubber of the series of synthetic rubbers, 0.3 to 30 phr cellulose and / or 0.3 to 30 phr cellulose acetate, 0.5 to 30 phr of cellulose acetate. 45 phr of triacetin, to 10 phr of at least one sulfur-containing acceleration system, a series of sulfur / sulfenamide systems, 50 to 90 phr of at least one oxygen-containing hydroxyl group filler, and 0.2 to 12 phr of at least one silane of a series of organic sulfur-containing silicon compounds. Rubber mixtures according to at least one of claims 1 to 7, characterized in that they comprise at least one rubber of the series styrene-butadiene and polybutadiene rubbers, 0.3 to 30 phr cellulose and / or cellulose acetate and 0.5 to 45 phr triacetin, to 10 phr of at least one acceleration system PUV 50101-2013 34628 / H — 01.02.2016 containing sulfur from a series of sulfur / sulfenamide systems, 50 to 90 phr of silicic acid with a specific surface area of 5 to 1000 m ² / g and 0.2 to 12 phr of at least one silane of bis (triethoxysilylpropyl) -tetrasulfide; bis (triethoxysilylpropyl) disulfide. Use of a composition comprising at least one cellulose and / or a cellulose derivative and triacetin as an additive for the preparation of a rubber composition according to any one of claims 1 to 8. Use according to claim 9, characterized in that the mixture comprises at least 99 to 1 part by weight of at least one cellulose and / or cellulose derivative and 1 to 99 parts by weight of triacetin. Use of a rubber composition according to any one of claims 1 to 8 for the manufacture of rubber vulcanizates or of a molded rubber product. Use according to claim 11, wherein the rubber vulcanizate and / or molded rubber product is in the form of a tire or tire part selected from the group consisting of tire treads, sidewalls, reinforced sidewalls of coasting tires, and apex mixtures. Use according to claim 11, wherein the rubber vulcanizate and / or molded rubber product is in the form of a technical rubber product selected from the group consisting of parts of dampers, cylinder linings, conveyor belts, belts, spindles, seals. Use according to claim 11, wherein the rubber vulcanizate and / or the shaped rubber product is in the form of a golf ball filling. Use according to claim 11, wherein the rubber vulcanizate and / or the shaped rubber product is in the form of a sole.