EP3258007B1 - Method for producing a reinforcing support - Google Patents

Description

The invention relates to a method for producing a reinforcement layer for elastomeric products. A reinforcing layer produced by the method as well as a vehicle tire including at least one reinforcing layer made by the method is also disclosed.

Strength supports for reinforcing various elastomeric products are well known. Here, the reinforcements are usually surrounded by at least one rubber mixture, which is also called Gummierungsmischung. One problem is that the reinforcements and the surrounding rubber mixture have different strengths. In particular, with ongoing mechanical and dynamic stress, such as when used in a vehicle tire while driving, therefore, sufficient adhesion between the strength carrier and the surrounding gum mixture is necessary.

In the prior art it is known to activate the strength members before the rubber coating for sufficient adhesion (adhesion activation), whereby usually so-called RFL dips (resorcinol-formaldehyde latex) are used, through which the strength members are immersed.

However, resorcinol and formaldehyde are classified as harmful to the environment and to health, so that one endeavors to provide alternatives for this purpose. This is what the EP 1745079 B1 as well as the DE 102014211365 A1 the treatment of textile tissue or textile reinforcements with a malein-functionalized polymer, for improved adhesion to rubber mixtures DE19955833A1 discloses a dipping method for producing a reinforcement layer comprising textile reinforcement for elastomeric products. The bath contains an epoxidized natural rubber in toluene.

After drying, a gum is applied with a gum mixture containing 50 phr of natural rubber and 50 phr of carbon black. US4472463 A discloses a 2-bath dip process for producing a reinforcing layer comprising textile reinforcements for elastomeric products. The first bath contains a blocked polyisocyanate and an epoxy compound. The second bath contains a vinyl pyridine-butadiene latex. After drying and heating, a gum is applied with a gum mixture containing 100 phr of natural rubber and 30 phr of carbon black.

The present invention is based on the object to provide a further process for producing a reinforcement layer comprising textile reinforcement, whereby the reinforcement layer produced have improved adhesion between reinforcements and gum mixture and should also be dispensed with environmentally and harmful substances.

• d) Tauchen der textilen Festigkeitsträger in wenigstens einem Bad, welches wenigstens einen epoxydierten Naturkautschuk-Latex (ENR-Latex) enthält und frei ist von freiem Resorcin und freiem Formaldehyd sowie deren Vorkondensaten, und
• e) Anschließendes Trocknen der Festigkeitsträger bei 120 bis 155 °C, und
• f) Anschließendes Erhitzen der Festigkeitsträger auf 210 bis 250 °C, und
• g) Gummierung der mittels d) bis f) vorbehandelten textilen Festigkeitsträger mit einer Gummierungsmischung, die wenigstens einen Dienkautschuk, der ausgewählt ist aus der Gruppe bestehend aus natürlichem Polyisopren und/oder synthetischem Polyisopren und/oder Butadien-Kautschuk und/oder Styrol-Butadien-Kautschuk, und 20 bis 90 phr wenigstens eines Füllstoffes ausgewählt aus der Gruppe bestehend aus Ruß und/oder Kieselsäure enthält.

This object is achieved according to the invention by a process for producing a reinforcement layer comprising textile reinforcement for elastomeric products, the method comprising at least the method steps in the following sequence:

• d) immersing the textile reinforcement in at least one bath which contains at least one epoxidized natural rubber latex (ENR latex) and is free from free resorcinol and free formaldehyde and their precondensates, and
• e) then drying the strength members at 120 to 155 ° C, and
• f) then heating the reinforcements to 210 to 250 ° C, and
• g) gumming of the textile reinforcing agents pretreated by d) to f) with a gumming composition comprising at least one diene rubber selected from the group consisting of natural polyisoprene and / or synthetic polyisoprene and / or butadiene rubber and / or styrene-butadiene rubber. Rubber, and 20 to 90 phr at least one filler selected from the group consisting of carbon black and / or silica.

A further subject matter of the present description is a reinforcement layer comprising textile reinforcement which has been produced by the method according to the invention.

Another object underlying the invention is to provide a vehicle tire having the same or even improved structural integrity Durability has to be waived in at least one reinforcement layer on umweit- and harmful substances. It should thus be created at least one environmentally friendly alternative.

This problem is solved by a vehicle tire, comprising in at least one component at least one reinforcement layer according to the invention, which was produced by the method according to the invention.

It has been found that the described reinforcement layer or the reinforcement layer of the described vehicle tire has a comparable or even improved adhesion between the reinforcements and the surrounding rubbering mixture, the adhesion level being comparable to the standard RFL dip treated reinforcements.

The vehicle tire is preferably a pneumatic vehicle tire.

According to the invention, the reinforcements in process step d) are treated by being dipped in at least one bath, the second bath containing at least one ENR latex polymer and being free from free resorcinol and free formaldehyde and their precondensates.

Epoxy-treated natural rubber (ENR) is known to the person skilled in the art.

Of epoxidized natural rubber, it is known that the degree of epoxidation can be determined, which indicates how many percent of the unopposed natural rubber-free double bonds are epoxidized.

According to an advantageous embodiment of the invention, an ENR latex with a degree of epoxidation of 50% is used, also known to the person skilled in the art as "ENR-50". According to a further advantageous embodiment of the invention, an ENR latex with a degree of epoxidation of 25% is used, also known to the person skilled in the art as "ENR-25".

In the present invention, it is used in the form of a latex. According to Römpp Online, "latex" refers to colloidal dispersions of polymers in aqueous media.

A suitable ENR-50 or ENR-25 is available, for example, from MMG (Muang Mai Guthrie Public Company Limited).

The second bath is preferably an aqueous dispersion which, in addition to water and the ENR latex, preferably contains at least one vinylpyridine polymer, preferably as latex (VP latex). Vinyl-pyridine-latex is a generic term known to those skilled in the art and comprises in particular VP latex from further monomers, such as typically the terpolymer of 15% vinyl pyridine, 15% styrene and 70% butadiene.

According to a preferred embodiment of the invention, the aqueous dispersion consists of 90 to 99.9 wt .-% of water, VP latex and the ENR latex. The aqueous dispersion here preferably contains 40 to 90% by weight of water and 5 to 40% by weight of VP latex and 5 to 40% by weight of the ENR latex, the total amount being 100% by weight. The quantities given here are based on anhydrous VP latex and anhydrous ENR latex, or in this case the water content contained in the VP latex dispersion has already been added to the total amount of water in the aqueous dispersion.

According to a particularly advantageous embodiment of the invention, the weight ratio of epoxidized natural rubber latex to vinylpyridine latex in the bath in process step d) is from 40:60 to 60:40, more preferably from 45:55 to 55:45, again particularly preferred 50 to 50.

The second bath according to step d) is free of free resorcinol and free formaldehyde and their precondensates, i. it contains 0 to 0.01 wt .-%, but preferably 0 wt .-%, of such substances.

In particular, the combination of the dipping containing ENR latex according to step d) with the preferred pre-dip containing diisocyanates according to step a), s. below, leads to comparable adhesion results of reinforcements to the respective surrounding gum mixture, the advantages in particular in a polyamide, preferably nylon, and a polyester, preferably PET, as textile reinforcing materials over a known from the prior art pretreatment with blocked diisocyanates show. Compared to known in the art RFL pretreatments a sufficient level of adhesion is achieved, which is dispensed with environmentally and harmful substances.

Subsequent to process step d), the reinforcements in process step e) are dried at 120 to 155 ° C. Again, this step is to first remove water so that it does not lead to side reactions in subsequent reactions. The duration of the drying step e) is preferably 30 to 120 seconds.

Following the drying in step e), the dried reinforcements are heated to 210 to 250 ° C. in process step f). This serves to react the deprotected substances from the first bath in step a) with the substances from the bath in step d). Preferably, the heating time in process step f) is 30 to 120 seconds.

1. a) Tauchen der textilen Festigkeitsträger in wenigstens einem ersten Bad, welches wenigstens ein geblocktes Diisocyanat enthält und frei ist von freiem Resorcin und freiem Formaldehyd sowie deren Vorkondensaten, und
2. b) Anschließendes Trocknen der Festigkeitsträger bei 120 bis 180 °C, und
3. c) Anschließendes Erhitzen der Festigkeitsträger auf 160 bis 230 °C.

The textile reinforcing materials are preferably treated in time prior to process step d) with at least the following process steps:

1. a) immersing the textile reinforcement in at least one first bath containing at least one blocked diisocyanate and is free of free resorcinol and free formaldehyde and their precondensates, and
2. b) Subsequent drying of the reinforcements at 120 to 180 ° C, and
3. c) then heating the reinforcements to 160 to 230 ° C.

In process step a), the reinforcements are thus preferably pretreated by immersion in at least one first bath, wherein the first bath contains at least one blocked diisocyanate and is free of free resorcinol and free formaldehyde and their precondensates. The textile reinforcements are still ungummed before and after this process step. The first bath is preferably an aqueous dispersion, in addition to water and the blocked diisocyanate may contain at least one epoxy compound such as glycerol triglyceride ether and / or bisphenol A diglycidyl ether and / or 2,3-epoxybutyl azide formate and / or sorbitol polyglycidyl ether. According to a preferred embodiment of the invention, the first bath contains at least one epoxy compound, preferably glycerol triglyceride ether, which is known, for example, under the trade name Grilbond® G 1701. Dipping in the reinforcement in this first bath is carried out in a manner known to those skilled in the art. Such a treatment step is also referred to as pre-dip.

The first bath is free of free resorcinol and free formaldehyde and their precondensates, i. it contains 0 to 0.01 wt .-%, but preferably 0 wt .-%, of such substances.

In the context of the present invention, blocked diisocyanates are understood to mean molecules which have two blocked, i. protected terminal isocyanate groups or formally formed by condensation of molecules with two isocyanate groups. These may be monomers, dimers, trimers or higher homologues of the diisocyanates.

Examples of diisocyanate monomers are methylenediphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), isophorone diisocyanate.

Diisocyanate trimers or higher homologs are grouped together as polyisocyanates and are compounds having three or more terminal isocyanate groups. They arise z. B. formally by condensation of three or more molecules, each with two isocyanate groups (diisocyanates). Formally, the condensation usually takes place via in each case one isocyanate group of each molecule, so that the polyisocyanates correspondingly have three or more isocyanate groups which are blocked only by a protective group and are available for further chemical reactions after / during the removal of the protective group , Because z. B. the 1,6-hexamethylene diisocyanate trimer formally formed by condensation of three 1,6-hexamethylene diisocyanate molecules on each one isocyanate group of the diisocyanates, has the 1,6-hexamethylene diisocyanate trimer three (remaining) terminal isocyanate groups.

As is known to those skilled in the art, the higher homologues of the precondensed isocyanates give, depending on the degree of condensation, average functionalities of greater than three.

The isocyanates can then be present as a mixture of different molecules with different functionalities, wherein the average number of terminal isocyanate groups corresponds to the average functionality. As known to the person skilled in the art, this so-called isocyanate number is determined by titration (ISO 14896/3, see Metrohm, Application Bulletin 200/3 e; http://www.google.de/url?sa=t&rct=j&q=&esrc= s & source = web & cd = 1 & ved = 0ahUKEwib np6n1KTNAhXoD8AKHQY4ApQQFggfMAA & url = http% 3A% 2F% 2Fpartners.metrohm. com% 2FGetDocument% 3Faction% 3Dget_dms_document% 26docid% 3D1662929 & usg = A FQjCNEOo_1vxWxdWsscUzU830rsT6JbxQ).

Preferably, the blocked diisocyanate has a functionality greater than 2. According to an advantageous embodiment of the invention, the blocked diisocyanate is a blocked polyisocyanate having a functionality of greater than or equal to 3, particularly preferably 3 to 5, very particularly preferably 3 to 4, for example, in particular 3.3. Here, the blocked polyisocyanate is preferably selected from the group consisting of blocked 1,6-hexamethylene diisocyanate trimer (HDI) and its blocked higher homologues and blocked toluene diisocyanate trimer and its blocked higher homologues as well as blocked isophorone diisocyanate trimer and its blocked higher homologs.

More preferably, the blocked polyisocyanate is blocked 1,6-hexamethylene diisocyanate trimer or blocked toluene diisocyanate trimer, most preferably 1,6-hexamethylene diisocyanate trimer.

The protecting groups of the blocked diisocyanate (s) may be any of the protecting groups known to those skilled in the art. Preferably, the protecting groups of the blocked polyisocyanate (s) are selected from the group consisting of ketoximes, such as preferably methyl ethyl ketoxime (MEKO), and / or pyrazole derivatives, such as preferably 3,5-dimethylpyrazole (DMP), and / or esters, such as preferably malonic acid esters or caprolactam or alkylated phenols. The protective group is preferably methyl ethyl ketoxime and / or 3,5-dimethylpyrazole.

According to a particularly advantageous embodiment of the invention, the blocked diisocyanate in process step a) methyl ethyl ketoxime blocked 1,6-hexamethylene diisocyanate trimer or 3,5-dimethylpyrazole blocked 1,6-hexamethylene diisocyanate trimer.

This results in combination with the ENR latex from step d) particularly good adhesive properties, which also can be dispensed with umweit- and harmful substances.

Subsequent to process step a), the reinforcements in process step b) are dried at 120 to 180 ° C. In this case, the temperature must not be too high, so that there is no deprotection of the blocked isocyanates to prevent an undesirable side reaction with the evaporating (residual) water. The duration of the drying step b) is preferably 30 to 120 seconds.

After drying, the dried reinforcements are heated in process step c) to 160 to 230 ° C to deprotect the isocyanates.

The heating time in step c) is preferably 30 to 120 seconds.

All of the described drying steps and steps for heating the reinforcements are carried out in devices known to those skilled in the art, such as in particular 1- or 2-zone furnaces, through which the reinforcements are preferably passed continuously.

The strength carriers treated by means of process steps d) to f), preferably a) to f), are in accordance with the invention in process step g) with at least one Gum mixture gummed, ie coated. The gum mixture for this purpose contains at least one diene rubber selected from the group consisting of natural polyisoprene and / or synthetic polyisoprene and / or butadiene rubber and / or styrene-butadiene rubber, and 20 to 90 phr of at least one filler selected from the group consisting of carbon black and / or silica. In the following, the ingredients of the gum mixture are explained in more detail. All embodiments also apply to the reinforcement layer according to the invention, which was produced by the method according to the invention and the vehicle tire having the reinforcement layer according to the invention in at least one component. It is clear to the person skilled in the art that the constituents, in particular the rubbers, are chemically modified in the vulcanized tire.

These may be all diene rubbers of the abovementioned group known to the person skilled in the art.

The gum mixture may contain polyisoprene (IR, NR) as the diene rubber. These may be both cis-1,4-polyisoprene and 3,4-polyisoprene. However, preference is given to the use of cis-1,4-polyisoprenes having a cis-1,4 content of> 90% by weight. First, such a polyisoprene can be obtained by stereospecific polymerization in solution with Ziegler-Natta catalysts or using finely divided lithium alkyls. On the other hand, natural rubber (NR) is such a cis-1,4-polyisoprene, the cis-1,4-content in natural rubber is greater than 99% by weight.

If the rubber mixture contains polybutadiene (BR) as the diene rubber, these may be either cis-1,4- or vinyl-polybutadiene (about 10-90% by weight vinyl content). Preference is given to the use of cis-1,4-polybutadiene with a cis-1,4 content greater than 90 wt .-%, which z. By solution polymerization in the presence of rare earth type catalysts.

As further diene rubbers styrene-butadiene copolymers can be used. The styrene-butadiene copolymers may be solution-polymerized styrene-butadiene copolymers (S-SBR) having a styrene content, based on the polymer, of about 10 to 45 Wt .-% and a vinyl content (content of 1,2-bound butadiene, based on the total polymer) of 10 to 70 wt .-%, which can be prepared, for example, using lithium alkyls in organic solvent. The S-SBR can also be coupled and end-group modified. However, it is also possible to use emulsion-polymerized styrene-butadiene copolymers (E-SBR) and mixtures of E-SBR and S-SBR. The styrene content of the E-SBR is about 15 to 50% by weight, and the types known in the art obtained by copolymerization of styrene and 1,3-butadiene in aqueous emulsion can be used.

The diene rubbers used in the mixture, in particular the styrene-butadiene copolymers, can also be used in a partially or fully functionalized form. The functionalization can be carried out with groups that can interact with the fillers used, in particular with OH-bearing fillers. It may be z. B. functionalizations with hydroxyl groups and / or epoxy groups and / or siloxane groups and / or amino groups and / or phthalocyanine groups and / or carboxy groups and / or silane-sulfide groups act.

The gum mixture preferably contains from 25 to 100 phr, particularly preferably from 50 to 100 phr, again particularly preferably from 70 to 100 phr of natural polyisoprene and / or synthetic polyisoprene, in which case natural polyisoprene is preferred.

According to a preferred embodiment of the invention, the gumming mixture contains 100 phr of at least one natural polyisoprene (NR) and / or synthetic polyisoprene (IR), whereby a mixture of NR and IR is conceivable.

According to a further preferred development of the invention, the gumming mixture contains 25 to 85 phr of at least one natural and / or synthetic polyisoprene and 15 to 50 phr of at least one butadiene rubber and / or 15 to 50 phr of at least one styrene-butadiene rubber. In particular, with these rubbers show, especially in reinforcing layers of vehicle tires, very good physical properties of the gumming mixture in terms of processability, durability and tear properties while achieving a sufficient level of adhesion.

The term phr (parts per hundred parts of rubber by weight) used in this document is the quantity used in the rubber industry for mixture formulations. The dosage of the parts by weight of the individual substances is always based on 100 parts by weight of the total mass of all the rubbers present in the mixture. The mass of all rubbers present in the mixture adds up to 100.

The gum mixture may contain as fillers carbon blacks and / or silicic acids, the fillers may be used in combination and the total amount of carbon black and silica is 20 to 90 phr. Preferably 30 to 90 phr, more preferably 50 to 70 phr of at least one carbon black are used.

According to an advantageous embodiment of the invention, the gumming mixture contains 50 to 100 phr of at least one natural and / or synthetic polyisoprene and 30 to 90 phr of at least one carbon black. This results in a particularly good structural durability of the reinforcement layer produced, especially when used in vehicle tires.

Furthermore, in small amounts, 0 to 10 phr, according to a preferred embodiment of 0.1 to 10 phr, further fillers such as aluminosilicates, chalk, starch, magnesium oxide, titanium dioxide or rubber gels may be included.

Furthermore, it is conceivable that the rubber mixture carbon nanotubes (CNT) including discrete CNTs, so-called hollow carbon fibers (HCF) and modified CNT containing one or more functional groups, such as hydroxyl, carboxyl and carbonyl groups).

Graphite and graphene as well as so-called "carbon-silica dual-phase filler" are conceivable as filler.

Preferably, however, the gum mixture is free of these further fillers, that is, it preferably contains 0 to 0.001 phr of these further fillers.

Zinc oxide is not considered a filler in the present invention.

When carbon black is used in the gum mixture, it is preferably those types having an STSA surface area (in accordance with ASTM D 6556) of more than 30 m ² / g, preferably 30 to 120 m ² / g. These can be easily incorporated and ensure low heat build-up.

According to a preferred development of the invention, the gumming mixture contains at least one carbon black having an iodine adsorption number according to ASTM D 1510 of 40 to 110 g / kg and an STSA surface (according to ASTM D 6556) of 40 to 120 m ² / g. With such a carbon black, in particular due to the comparatively high surface area, a sufficient reinforcement and strength of the rubberizing mixture is achieved in order to balance the differences in strength between reinforcements and rubber of the rubbering mixture as well as possible. A possible preferred type of carbon black is, for example, carbon black N326 having an iodine adsorption number according to ASTM D 1510 of 82 g / kg and an STSA surface (according to ASTM D 6556) of 76 m ² / g. Another possible preferred type of carbon black is, for example, carbon black N660 having an iodine adsorption number according to ASTM D 1510 of 36 g / kg and an STSA surface (according to ASTM D 6556) of 34 m ² / g.

If silicas are present in the mixture, these may be the silicas customary for tire rubber mixtures. It is particularly preferred when a finely divided, precipitated silica is used which has a CTAB surface area (according to ASTM D 3765) of 30 to 350 m ² / g, preferably from 120 to 250 m ² / g. As silicic acids it is possible to use both conventional silica such as VN3 (trade name) from Evonik and highly dispersible silicas, so-called HD silicas (eg Ultrasil 7000 from Evonik). Silicas are preferably used in amounts of less than 15 phr.

To improve the processability and to attach the silica and other optional polar fillers to the diene rubber silane coupling agents can be used in rubber mixtures. Here, one or more different silane coupling agents can be used in combination with each other. The gum mixture may thus contain a mixture of different silanes.

The silane coupling agents react with the superficial silanol groups of the silica or other polar groups during the mixing of the rubber or the rubber mixture (in situ) or even before the addition of the filler to the rubber in the sense of a pretreatment (pre-modification). All silane coupling agents known to the person skilled in the art for use in rubber mixtures can be used as silane coupling agents. Such known from the prior art coupling agents are bifunctional organosilanes having on the silicon atom at least one alkoxy, cycloalkoxy or phenoxy group as a leaving group and have as other functionality a group which may optionally undergo a chemical reaction with the double bonds of the polymer after cleavage , In the latter group may be z. For example, they may be the following chemical groups:
-SCN, -SH, -NH ₂ or -S _x - (where x = 2 to 8).

Thus, as silane coupling agents z. For example, 3-mercaptopropyltriethoxysilane, 3-thiocyanato-propyltrimethoxysilane or 3,3'-bis (triethoxysilylpropyl) polysulfides having 2 to 8 sulfur atoms, such as. For example, 3,3'-bis (triethoxysilylpropyl) tetrasulfide (TESPT), the corresponding disulfide (TESPD) or mixtures of the sulfides having 1 to 8 sulfur atoms with different contents of the various sulfides, are used. For example, TESPT can also be added as a mixture with carbon black (trade name X50S® from Evonik).

Preference is given to using a silane mixture which comprises 40 to 100% by weight of disulfides, particularly preferably 55 to 85% by weight of disulfides and very particularly preferably 60 to 80% by weight of disulfides. Such a mixture is available, for example, under the trade name Si 261® Evonik, which, for example, in the DE 102006004062 A1 is described.

Also blocked mercaptosilanes, as z. B. from the WO 99/09036 are known, can be used as a silane coupling agent. Also silanes, as in the WO 2008/083241 A1 , of the WO 2008/083242 A1 , of the WO 2008/083243 A1 and the WO 2008/083244 A1 can be used, can be used. Suitable for. B. silanes, which are sold under the name NXT in different variants by the company Momentive, USA, or those sold under the name VP Si 363® by Evonik Industries. Furthermore, it is conceivable that one of the abovementioned mercaptosilanes, in particular 3-mercaptopropyltriethoxysilane, can be used in combination with processing aids (which are listed below), in particular PEG-carboxylic acid esters.

According to a preferred embodiment of the invention, the gum mixture contains a combination of 3-mercaptopropyltriethoxysilane and PEG carboxylic acid ester, which gives particularly good properties, in particular with regard to the technical problem to be solved and overall good property level with respect to the other properties.

Furthermore, the gumming mixture can contain further activators and / or agents for the binding of fillers, in particular carbon black. This may be, for example, the example in the EP 2589619 A1 disclosed compound S- (3-aminopropyl) thiosulfuric acid and / or their metal salts, resulting in very good physical properties of the gumming especially when combined with at least one carbon black as a filler.

From 0 to 70 phr, preferably from 0.1 to 60 phr, of at least one plasticizer may be present in the gum mixture. These include all plasticizers known to those skilled in the art, such as aromatic, naphthenic or paraffinic mineral oil plasticizers, such as, for example, MES (mild extraction solvate) or TDAE (treated distillate aromatic extract), or rubber-to-liquid oils (RTL) or biomass-to-liquid. Oils (BTL, as used in the DE 10 2008 037714 A1 disclosed)) or oils based on renewable raw materials (such as rapeseed oil, terpene oils (eg orange oils) or Faktisse or plasticizer resins or liquid polymers (such as liquid BR) whose average molecular weight (determination by GPC = gel permeation chromatography, based on BS ISO 11344: 2004) is between 500 and 20000 g / mol Gum mixture Liquid polymers used as plasticizers are not included as rubber in the calculation of the composition of the polymer matrix (phr calculation).

When using mineral oil, this is preferably selected from the group consisting of DAE (Distilled Aromatic Extracts) and / or RAE (Residual Aromatic Extract) and / or TDAE (Treated Distilled Aromatic Extracts) and / or MES (Mild Extracted Solvents) and / or naphthenic oils.

1. A) Alterungsschutzmittel, wie z. B. N-Phenyl-N'-(1,3-dimethylbutyl)-p-phenylendiamin (6PPD), N,N'-Diphenyl-p-phenylendiamin (DPPD), N,N'-Ditolyl-p-phenylendiamin (DTPD), N-Isopropyl-N'-phenyl-p-phenylendiamin (IPPD), 2,2,4-Trimethyl-1,2-dihydrochinolin (TMQ) und andere Substanzen, wie sie beispielsweise aus J. Schnetger, Lexikon der Kautschuktechnik, 2. Auflage, Hüthig Buch Verlag, Heidelberg, 1991, S. 42-48 bekannt sind,
2. B) Aktivatoren, wie z. B. Zinkoxid und Fettsäuren (z. B. Stearinsäure),
3. C) Wachse,
4. D) Harze, insbesondere Klebharze, die keine Weichmacherharze sind,
5. E) Methylenakzeptoren, wie Resorcin und Resorcinäquivalente, und/oder Methylendonor/Formaldehydspender, wie z. B. Hexamethoxymethylmelamin (HMMM) und/oder Hexamethylentetramin (HMT)
6. F) Mastikationshilfsmittel, wie z. B. 2,2'-Dibenzamidodiphenyldisulfid (DBD) und
7. G) Verarbeitungshilfsmittel, wie z.B. Fettsäuresalze, wie z.B. Zinkseifen, und Fettsäureester und deren Derivate, wie z.B. PEG-Carbonsäureester.

Furthermore, the gum mixture may contain conventional additives in conventional parts by weight. These additives include

1. A) anti-aging agents, such. N-phenyl-N '- (1,3-dimethylbutyl) -p-phenylenediamine (6PPD), N, N'-diphenyl-p-phenylenediamine (DPPD), N, N'-ditolyl-p-phenylenediamine (DTPD ), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) and other substances, such as those of J. Schnetger, Encyclopedia of Rubber Technology, 2nd edition, Hüthig Book Verlag, Heidelberg, 1991, pp. 42-48 are known,
2. B) activators, such. Zinc oxide and fatty acids (eg stearic acid),
3. C) waxes,
4. D) Resins, in particular tackifier resins which are not plasticizer resins,
5. E) methylene acceptors, such as resorcinol and resorcinol equivalents, and / or methylene donor / formaldehyde donors, such as. Hexamethoxymethylmelamine (HMMM) and / or hexamethylenetetramine (HMT)
6. F) Mastikationshilfsmittel such. B. 2,2'-Dibenzamidodiphenyldisulfid (DBD) and
7. G) processing aids, such as fatty acid salts, such as zinc soaps, and fatty acid esters and their derivatives, such as PEG carboxylic acid ester.

The vulcanization is carried out in the presence of sulfur and / or sulfur donors, with some sulfur donors can also act as a vulcanization accelerator. Sulfur or sulfur donors are added in the last mixing step in the amounts customary by the skilled person (0.4 to 8 phr, sulfur, preferably in amounts of 0.4 to 4 phr) of the gum mixture. The vulcanization can also be done in Presence of very small amounts of sulfur in combination with sulfur-donating substances done.

Furthermore, the gum mixture may contain vulcanization-affecting substances such as vulcanization accelerators, vulcanization retarders and vulcanization activators in conventional amounts in order to control the time and / or temperature of vulcanization required and to improve the vulcanizate properties. The vulcanization accelerators may be selected, for example, from the following groups of accelerators: thiazole accelerators such as. B. 2-mercaptobenzothiazole, sulfenamide accelerators such as. B. benzothiazyl-2-cyclohexylsulfenamid (CBS), guanidine accelerators such as. N, N'-diphenylguanidine (DPG), dithiocarbamate accelerators such as. As zinc dibenzyldithiocarbamate, disulfides, thiophosphates. The accelerators can also be used in combination with each other, which can result in synergistic effects.

The preparation of the gum mixture is carried out in a conventional manner, wherein first of all a masterbatch containing all constituents except for the vulcanization system (sulfur and vulcanization-affecting substances) is prepared in one or more mixing stages followed by the addition of the curing system is produced. Subsequently, the mixture is processed further.

The gumming of the reinforcement in step g) also takes place in a manner known to those skilled in the art.

In the following, the properties of the textile reinforcement are explained in more detail. All embodiments apply to the method according to the invention, the reinforcement layer produced and the vehicle tires produced.

The textile reinforcements preferably comprise polyethylene terephthalate (PET) and / or polyethylene naphthalate (PEN) and / or polybutylene terephthalate (PBT) and / or Polycarbonate (PC) and / or cellulose and / or cellulose ester and / or m-aramid and / or p-aramid and / or a mixture of m-aramid and p-aramid and / or a polyamide which is selected from the group of polyamide 46 (PA 4.6) and / or polyamide 410 (PA 4.10) and / or polyamide 6 (PA 6) and / or polyamide 66 (PA 6.6 polyhexamethylene adipamide) and / or polyamide 612 (PA 6.12) and / or polyamide 1010 ( PA 10.10) and / or polyamide 1212 (PA 12.12).

The textile reinforcements particularly preferably comprise polyethylene terephthalate (PET) and / or cellulose and / or cellulose esters and / or polyamide 66 (PA 6.6 polyhexamethylene adipamide).

The textile reinforcement are preferably cords having at least one twisted yarn.

In this case, all known in the prior art subtleties (titer in the unit dtex) and twisting of the cords and yarns are conceivable. It is expedient if the denier of each yarn is between 200 and 5000 dtex and if the twist of the yarns and cords is between 100 and 800 t / m.

The textile reinforcements preferably have the properties mentioned before step d), i. they are first twisted and then treated with the process steps d) to f), preferably a) to f).

In the event that the textile reinforcement are embedded as a fabric in the gumming, preferably after twisting and before the treatment according to the process steps d) to f), preferably a) to f), as known in the art, a weaving step.

According to a preferred development of the invention, the reinforcing members are cords of a respective yarn, with which a twisted yarn represents a cord in each case.

According to a further preferred development of the invention, the strength carriers are cords of at least two, more preferably two, yarns.

According to a further preferred embodiment of the invention, the reinforcement layer according to the invention or that of the vehicle tire according to the invention contains cords of different numbers of yarns as reinforcement.

The reinforcement layer produced can be used in all components of a vehicle tire, which contain reinforcing materials, with the above-mentioned advantages in terms of substances and the production and the sufficient adhesion. These components are, in particular, the carcass ply and / or the belt (in the belt layer or layers) and / or the belt bandage and / or the bead reinforcement.

The advantages described above are also achieved in the use of the above-described reinforcement layer for the production of other elastomeric products, such as conveyor belts, drive belts, hoses and bellows.

The invention will now be explained in more detail with reference to the following examples.

Inventive Example 1 (E1): Nylon cords as textile reinforcements, dip containing ENR-50 latex

Nylon cords made from two nylon yarns each having a 940 dtex (940 x 2) thickness were obtained by a pre-dip containing 94.2% by weight of water and 0.4% by weight of Grilbond® G 1701 and 5 4% by weight of Edolan® XCIB (MEKO-blocked HDI trimer). Subsequently, the cords were dried for 30 to 120 seconds at 140 ° C and then heated to 200 ° C.

These cords were then dipped through another dip bath containing 46.7% by weight of water and 27.1% by weight of VP latex (40% by weight solids of the terpolymer of 15% vinylpyridine, 15 % Styrene and 70% butadiene in water, ie 10.8% by weight of the terpolymer) and 26.2% by weight of ENR latex (ENR-50, MMG, solids content 43.7% by weight in water, ie, 11.4% by weight of ENR). It was then dried again at 170 ° C. for 30 to 120 seconds and then heated to 225 ° C.

Comparative Example 1 (V1): Nylon cords as textile reinforcement, RFL dip

Nylon cords made of two 940 dtex (940 x 2) nylon yarns each were provided by an RFL dip containing 46.5% by weight of water and 45.7% by weight of VP latex (40% by weight) % Solids content of the terpolymer of 15% vinylpyridine, 15% styrene and 70% butadiene in water) and 2.2% by weight of ammonium hydroxide and 0.2% by weight of sodium hydroxide and 3.1% by weight of resorcinol Formaldehyde resin (penacolite, aqueous solution having a solids content of 75 wt .-%) and 2.3 wt .-% formaldehyde dipped. Subsequently, the cords were dried for 30 to 120 seconds at 125 ° C and then heated to 220 ° C.

Inventive Example 2 (E2): Polyester cords as textile reinforcements, dip containing ENR-50 latex

Cores of polyester made from two polyester yarns (polyethylene terephthalate PET) having a thickness of 1440 dtex (1440 x 2) were obtained by a pre-dip containing 94.2% by weight of water and 0.4% by weight of Grilbond® G 1701 and 5.4% by weight Edolan® XCIB (MEKO-blocked HDI trimer) dipped. Subsequently, the cords were dried for 30 to 120 seconds at 140 ° C and then heated to 200 ° C.

These dried cords were dipped through another dip bath containing 56.9 wt.% Water and 21.9 wt.% VP latex (40 wt.% Solids content of the terpolymer of 15% vinylpyridine, 15 % Styrene and 70% butadiene in water) and 21.2 wt% ENR-50 latex (ENR-50, MMG, solids content 43.7 wt% in water). It was then dried again for 30 to 120 seconds at 150 ° C and then heated to 240 ° C.

Comparative Example 2 (V2): PET cords as textile reinforcement, RFL dip

Cords made of polyester each made of two 940 dtex (940 × 2) polyester yarns (polyethylene terephthalate PET) were coated by an RFL dip containing 48.8% by weight of water and 41.6% by weight of VP Latex (40% by weight solids content of the terpolymer of 15% vinyl pyridine, 15% styrene and 70% butadiene in water) and 3.4% by weight Grilbond IL-6 (caprolactam blocked MDI) and 0.5% by weight. % Sodium hydroxide and 4.3% by weight of resorcinol-formaldehyde resin (penacolite; aqueous solution with a Solids content of 75% by weight) and 1.3% by weight of formaldehyde. Subsequently, the cords were dried for 30 to 120 seconds at 130 ° C and then heated to 230 ° C.

In all the cords, the drying step, which involves hot drawing, was unaffected by the maleimide polymer, i. as known to the skilled person. This serves to adjust the properties, such as elongation at break, elongation at break and heat shrinkage of the cord by targeted stretching to the desired level. wherein the tension applied to the cord is varied between tension and relaxation.

Comparison of adhesion Example 1 (El) vs. Comparative Example 1 (V1) and E2 vs. V2

Adhesive tests, so-called peel tests, according to ISO 36: 2011 (E) with evaluation in accordance with DIN ISO 6133 without aging were carried out with the differently treated cords. For this purpose, the strength carrier cords were rubberized with an uncured gum mixture having the composition according to Table 1 (according to process step g)) and then vulcanized. The gumming takes place by placing the cords on or between calendered thin rubber sheets of the gumming compound and then compressing the entire specimen in the heating press.

Then, the force for peeling off the mixture from the cords was determined (adhesion), and the coverage of the cords with mixture after peeling was optically determined. 5 means complete coverage, 0 means no rubber remains on the cord. Furthermore, the breaking force, the elongation at 45 N, the shrinkage at 180 ° C and the residual shrinkage based on ASTM D 855 were determined.

The results of the adhesion tests are shown in Table 2.

The reinforcement layer produced by means of the method according to the invention shows as shown in Table 2 a comparable or even improved durability, since the Adhesion of the strength carrier to the gum mixture is comparable or even improved in part. Furthermore, in the example of the invention, the disadvantages associated with resorcinol and formaldehyde are avoided. Table 1: Components of the gum mixture ingredients Quantity (phr) NR / IR 70 BR / SBR 30 Soot N660 50 Processing oil / adhesive resin 5 Other additives ^a) 8th Resin from resorcinol and formaldehyde donor 5 Sulfur and accelerator 3.3 a) anti-aging agent, ZnO, stearic acid property unit V1 E1 V2 E2 liability N / 25mm 197 161 184 191 covering (1 to 5) 4.8 4.7 4.5 5

A vehicle tire produced by means of the method according to the invention, preferably a pneumatic vehicle tire, which contains at least one manufactured reinforcement layer in at least one component, is distinguished by a durability comparable to the prior art, with the activation of adhesion in the dips being based on the use of free resorcinol and formaldehyde as well Resorcinol formaldehyde precondensates can be dispensed with.

Claims (7)

1. Process for producing a strength member ply comprising textile strength members for elastomeric articles of manufacture, wherein the process comprises at least the following process steps in the following sequence:

   d)immersing the textile strength members in at least one bath which contains at least one epoxidized natural rubber latex and is free from free resorcinol and free formaldehyde and precondensates thereof, and

   e)subsequently drying the strength members at 120°C to 155°C, and

   f)subsequently heating the strength members to 210°C to 250°C, and

   g)rubberizing the textile strength members pretreated by means of d) to f) with a rubberizing mixture containing at least one diene rubber selected from the group consisting of natural polyisoprene and/or synthetic polyisoprene and/or butadiene rubber and/or styrene-butadiene rubber and
   20 to 90 phr of at least one filler selected from the group consisting of carbon black and/or silica.
2. Process according to Claim 1, characterized in that the bath in process step d) contains at least one vinyl-pyridine latex.
3. Process according to Claim 2, characterized in that the weight ratio of epoxidized natural rubber latex to vinyl-pyridine latex in the bath is from 40:60 to 60:40.
4. Process according to any of the preceding claims, characterized in that prior to process step d) the textile strength members are treated with at least the following process steps:

   a) immersing the textile strength members in at least one first bath which contains at least one blocked diisocyanate and is free from free resorcinol and free formaldehyde and precondensates thereof, and

   b) subsequently drying the strength members at 120°C to 180°C, and

   c) subsequently heating the strength members to 160°C to 230°C.
5. Process according to any of the preceding claims, characterized in that the textile strength members contain polyethylene terephthalate (PET) and/or polyethylene naphthalate (PEN) and/or polybutylene terephthalate (PBT) and/or polycarbonate (PC) and/or cellulose and/or cellulose ester and/or m-aramid and/or p-aramid and/or a mixture of m-aramid and p-aramid and/or a polyamide selected from the group consisting of polyamide 46 (PA 4.6) and/or polyamide 410 (PA 4.10) and/or polyamide 6 (PA 6) and/or polyamide 66 (PA 6.6 polyhexamethylene adipinamide) and/or polyamide 612 (PA 6.12) and/or polyamide 1010 (PA 10.10) and/or polyamide 1212 (PA 12.12).
6. Process according to any of the preceding claims, characterized in that the rubberizing mixture contains 50 to 100 phr of at least one natural and/or synthetic polyisoprene and 30 to 90 phr of at least one carbon black.
7. Process according to any of the preceding claims, characterized in that the carbon black of the rubberizing mixture has an iodine adsorption number according to ASTM D 1510 of 40 to 110 g/kg and an STSA surface area (according to ASTM D 6556) of 40 to 120 m²/g.