EP3258006B1 - Method for producing a reinforcing support, reinforcing support and vehicle tyre - Google Patents

Description

The invention relates to a method for producing a reinforcement layer for elastomeric products and to a reinforcement layer produced by the method. Furthermore, the invention relates to a vehicle tire which contains at least one reinforcement layer according to the invention.

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.
Furthermore, inter alia, blocked isocyanate and / or epoxy compounds in combination with RFL dips are used to further activate the strength carriers. The WO 2005/026239 A1 for example, discloses the use of polyisocyanates and RFL without epoxy compounds.

However, resorcinol and formaldehyde are classified as harmful to the environment and to health, so that one endeavors to provide alternatives for this purpose. So revealed US 4472463 the use of polyisocyanates without RFL dips. In addition, the reveal EP 1745079 B1 as well as the DE 102014211365 A1 the treatment of textile fabric or textile reinforcements with a maleic-functionalized polymer to achieve improved adhesion to rubber compounds.

The present invention is based on the object to provide a method for producing a reinforcement layer comprising textile reinforcement, whereby the reinforcement layer produced have the same or even improved adhesion between reinforcements and rubberizing mixture and should also be dispensed with umweit- and harmful substances.

1. a) Tauchen der textilen Festigkeitsträger in wenigstens einem ersten Bad, welches wenigstens ein geblocktes Polyisocyanat enthält und frei ist von freiem Resorcin und freiem Formaldehyd sowie deren Vorkondensaten, wobei das Polyisocyanat eine Funktionalität von größer oder gleich 3 aufweist, und
2. b) Anschließendes Trocknen der Festigkeitsträger bei 120 bis 180 °C, und
3. c) Anschließendes Erhitzen der Festigkeitsträger auf 160 bis 230 °C, und
4. d) Tauchen der textilen Festigkeitsträger in wenigstens einem zweiten Bad, welches wenigstens ein Malein-funktionalisertes Polymer enthält und frei ist von freiem Resorcin und freiem Formaldehyd sowie deren Vorkondensaten, und
5. e) Anschließendes Trocknen der Festigkeitsträger bei 120 bis 155 °C, und
6. f) Anschließendes Erhitzen der Festigkeitsträger auf 210 bis 250 °C, und
7. g) Gummierung der mittels a) 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:

1. a) immersing the textile reinforcement in at least one first bath, which contains at least one blocked polyisocyanate and is free of free resorcinol and free formaldehyde and their precondensates, wherein the polyisocyanate has a functionality of greater than or equal to 3, 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, and
4. d) immersing the textile reinforcement in at least one second bath, which contains at least one malein-functionalized polymer and is free of free resorcinol and free formaldehyde and their precondensates, and
5. e) then drying the strength members at 120 to 155 ° C, and
6. f) then heating the reinforcements to 210 to 250 ° C, and
7. g) gumming of the textile reinforcements pretreated by means of a) 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 of at least one filler selected from the group consisting of carbon black and / or silica.

Another object of the present invention is a reinforcement layer comprising textile reinforcement, which was prepared by the inventive method.

A further object on which the invention is based is to provide a vehicle tire which has an improved or at least the same structural durability, wherein it is intended to dispense with substances harmful to health and the environment in at least one reinforcement layer. It should thus be created at least one environmentally friendly alternative.

This object is achieved according to the invention by a vehicle tire, comprising in at least one component at least one reinforcement layer according to the invention, which was prepared by the method according to the invention.

It has been found that the reinforcement layer according to the invention or the reinforcement layer of the vehicle tire according to the invention has improved adhesion between the reinforcements and the surrounding rubber 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 textile reinforcements in step a) are pretreated by immersion in at least one first bath, the first bath containing at least one polyisocyanate blocked with a functionality of greater than or equal to 3 and 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 containing, in addition to water and the blocked polyisocyanate, 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, may contain.

According to a preferred embodiment of the invention, the first bath contains at least one epoxy compound, preferably glycerol triglyceride ether, which is e.g. known 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 polyisocyanates are understood as meaning substances which have three or more terminal 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.

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).

The blocked polyisocyanate has 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 as well as blocked toluene diisocyanate trimer and its blocked higher homologues as well as blocked isophorone diisocyanate trimer and its blocked higher homologs.

Preferably, the blocked polyisocyanate is blocked 1,6-hexamethylene diisocyanate trimer or blocked toluene diisocyanate trimer, more preferably 1,6-hexamethylene diisocyanate trimer.

Since the 1,6-hexamethylene diisocyanate trimer is formed formally by condensation of three 1,6-hexamethylene diisocyanate molecules on one isocyanate group of the diisocyanates, the 1,6-hexamethylene diisocyanate trimer has three (remaining) terminal isocyanate groups ,

The protecting groups of the blocked polyisocyanate (s) may be any protecting group known to those skilled in the art. The protective groups of the blocked polyisocyanate (s) are preferably 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, as preferred malonic acid ester 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 polyisocyanate 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 maleic polymer from step b) particularly good adhesive properties, in addition to environmental and harmful substances can be dispensed with.

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 an undesirable To prevent 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. According to the invention, the reinforcements in process step d) are treated by being dipped in at least one second bath, the second bath containing at least one malein-functionalized polymer and being free of free resorcinol and free formaldehyde and their precondensates.
A maleic-functionalized polymer is a polymer which carries maleic groups as functional groups by reaction with maleic acid and / or maleic anhydride. A malein-functionalized polymer is available, for example, under the trade name Ricobond® 7004 from Cray Valley as an aqueous dispersion.
The second bath is preferably an aqueous dispersion which preferably contains at least one VP latex (vinyl pyridine latex, typically 15% vinyl pyridine, 15% styrene and 70% butadiene) in addition to water and the malein functionalized polymer. According to a preferred embodiment of the invention, the aqueous dispersion consists of 90 to 99.9 wt .-% of water, VP latex and said maleic polymer. The aqueous dispersion here preferably comprises 40 to 90% by weight of water and 5 to 40% by weight of VP latex and 1 to 10% by weight of the said maleic polymer. The VP latex is likewise preferably used as aqueous dispersion, the above quantities being based on anhydrous VP latex, or the water content contained in the VP latex dispersion already having been added to the total amount of water of the aqueous dispersion.

Like in the EP 1745079 B1 discloses arise from malein-functionalized polymers by reaction with amines imide functionalities and thus maleimide polymers. Since not all malein groups have to be converted into imide groups, For example, the resulting maleimide polymer has both maleic and imide groups.

The terms "group" and "functionalization" are used synonymously in the context of the chemical characteristics of the polymers used.

The maleic polymer used preferably has a molecular weight of 5,000 to 20,000 g / mol, particularly preferably 5,000 to 15,000 g / mol, very particularly preferably 7,000 to 13,000 g / mol, again very particularly preferably 10,500 to 13,000 g / mol.
With such a molecular weight of the maleic polymer, sufficient adhesion to the strength member results, and the workability of the dispersion is good.

The maleic-functionalized polymer described above, according to a preferred embodiment of the invention, is a polybutadiene.

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 the maleic polymer according to step d) with said pre-dip containing polyisocyanates according to step a) leads to improved adhesion results of reinforcing agents to the respective surrounding rubberizing mixture, wherein the advantages in particular in a polyamide, preferably nylon, and a polyester, preferably PET, as textile reinforcing materials in comparison to a pretreatment with blocked diisocyanates known from the prior art. Compared to RFL pretreatments known in the prior art, a sufficient level of adhesion is achieved, omitting substances harmful to health and the environment.

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 second bath in step d). Preferably, the heating time in process step f) is 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 method steps a) to f) are gummed according to the invention in step g) with at least one gumming mixture, i. jacketed. 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 can be solution-polymerized styrene-butadiene copolymers (S-SBR) having a styrene content, based on the polymer, of about 10 to 45% by weight and a vinyl content (content of 1.2 bound butadiene, based on the total polymer) of from 10 to 70% by weight, which can be prepared using, for example, 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 completely functionalized form become. 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, particularly in reinforcing layers of vehicle tires, very good physical properties of the rubberizing mixture are manifested 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.
However, the gum mixture is preferably free of these further fillers, ie 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 which has 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 out The coupling agents known in the prior art are bifunctional organosilanes which have at least one alkoxy, cycloalkoxy or phenoxy group as leaving group on the silicon atom and which, as other functionality, have a group which, if desired, can 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 , the WO 2008/083242 A1 , 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 gumming 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 a good level of properties with regard 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 If liquid polymers are used as plasticizers in the gumming mixture, they are not used as rubber in the calculation of the composition of the polymer matrix (phr calculation). on.
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 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 carried out in the presence of very small amounts of sulfur in combination with sulfur-donating substances.

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. 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 are valid for the inventive method, the reinforcement layer according to the invention and the vehicle tire according to the invention.

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 esters 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 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 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 reinforcing materials preferably have the stated properties already before process step a), ie they are first twisted and then treated with process steps a) to f).
In the event that the textile reinforcing elements are embedded as a tissue in the rubberizing mixture, preferably after twisting and before the treatment according to the process steps a) to f), as known to those skilled in 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 according to the invention can be used in all components of a vehicle tire, which contain reinforcements, resulting in the above-mentioned advantages in terms of substances and the production and 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, pre-dip containing DMP-blocked HDI trimer, dip containing maleic polymer

Nylon cords made from two 940 dtex (940 x 2) nylon yarns each were made by a pre-dip containing 95.54 weight percent water and 0.75 weight percent Grilbond® G 1701 and 3 , 71% by weight of Acrafix PCI (DMP-blocked HDI trimer, solids content about 31.5% by weight). Subsequently, the cords were dried for 30 to 120 seconds at 165 ° C and then heated to 225 ° C.

These cords were dipped through another dip bath containing 54% by weight of water and 42.4% by weight of VP latex (40% by weight of VP polymer in water, ie 17% by weight of VP). Latex in the dip) and 3.6% by weight of RICOBOND 7004, Cray Valley (30% by weight of maleic polymer in water: mean value from manufacturer's information 25 to 35% by weight). It was then dried again at 140 ° C. for 30 to 120 seconds and then heated to 235 ° C.

Comparative Example 1 (V1): Nylon Cords as Textile Reinforcements, Pre-Dip Containing Caprolactam Blocked MDI, Dip Containing Maleic Polymer

The cords according to Comparative Example 1 (V1) were prepared analogously to E1 with the exception that instead of Acrafix PCI (DMP-blocked HDI trimer) Grilbond® IL-6 (caprolactam blocked MDI) was used. The pre-dip contained 96.71% by weight of water and 2.54% by weight of Grilbond® IL-6 and 0.75% by weight of Grilbond® G 1701.

For all the cords, the process step of drying involving hot drawing was undisturbed, ie, as known to those skilled in the art. This serves to improve the properties, such as elongation at break, elongation at break and heat shrinkage of the cord by targeted stretching on the desired level, wherein the voltage applied to the cord between tension and relaxation is varied.

Comparison of liability Example 1 (E1) vs. Comparative Example 1 (V1)

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. 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

The reinforcement layer produced by means of the method according to the invention shows, as can be seen in Table 2, a comparable or even improved durability, since the adhesion of the reinforcements to the rubber coating mixture is improved. Furthermore, in the example of the invention, the disadvantages associated with resorcinol and formaldehyde are avoided. Table 2 property unit V1 E1 liability N / 25mm 190.7 195.4 covering (1 to 5) 3.5 4.5 breaking force N 150 152 Elongation at 45 N % 5.4 5.2 Shrinkage at 180 ° C % 6.1 6.0 Residual shrinkage % 3.7 3.6

Inventive Example 2 (E2): polyester cords as textile reinforcements, pre-dip containing MEKO blocked HDI trimer, dip containing maleic polymer

Cores of polyester made from two polyester yarns (polyethylene terephthalate PET) with a thickness of 1440 dtex (1440 x 2) were obtained by a pre-dip containing 96.71% by weight of water and 0.75% by weight of Grilbond® G 1701 and 2.54 wt% Edolan® XCIB (MEKO-blocked HDI trimer) dipped. Subsequently, the cords were dried for 30 to 120 seconds at 160 ° C and then heated to 235 ° C.

These dried cords were dipped through another dip bath containing 54% by weight of water and 42.4% by weight of VP latex (40% by weight VP polymer in water) and 3.6% by weight. % RICOBOND 7004, Cray Valley (30 wt .-% maleic polymer in water: average from manufacturer 25 to 35 wt .-%) contained. It was then dried again at 165 ° C. for 30 to 120 seconds and then heated to 235 ° C.

Inventive Example 3 (E3): polyester cords as textile reinforcement, pre-dip containing MEKO blocked TDI trimer, dip containing maleic polymer

The cords according to Inventive Example 3 (E3) were prepared analogously to E2 with the exception that instead of Edolan® XCIB (MEKO-blocked HDI trimer) 2.54% by weight Baygard® EDW (MEKO blocked TDI) was used.

Comparative Example 2 (V2): polyester cords as textile reinforcements, pre-dip containing caprolactam blocked MDI, dip containing maleic polymer

The cords according to Comparative Example 2 (V2) were prepared analogously to E2, except that 2.54% by weight of Grilbond IL-6 (caprolactam blocked MDI) was used instead of Edolan® XCIB (MEKO-blocked HDI trimer).

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.

The cords of Examples E2 and E3 and V2 were gummed analogously to Examples E1 and V1 with a gumming mixture according to Table 2 and then the adhesion and coverage as well as the rigidity were tested as described above.
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 are summarized in Table 3. Table 3 property unit V2 E2 E3 liability N / 25mm 108 125 125 covering (1 to 5) 4 5 4.7 breaking force N 201 198 198 Elongation at 45 N % 2.9 2.9 2.9 Shrinkage at 180 ° C % 5.1 4.8 4.9 Residual shrinkage % 4.9 4.6 4.7

A vehicle tire according to the invention, preferably a pneumatic vehicle tire, which contains at least one reinforcement layer produced according to the invention 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 as resorcinol-formaldehyde Pre-condensates can be dispensed with.

Claims (11)

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

   a) dipping the textile strength members into at least one first bath which contains at least one blocked polyisocyanate and is free of free resorcinol and free formaldehyde and precondensates thereof, where the polyisocyanate has a functionality of not less than 3, and

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

   c) subsequently heating the strength members to 160 to 230°C, and

   d) dipping the textile strength members into at least one second bath which contains at least one malein-functionalized polymer and is free of free resorcinol and free formaldehyde and precondensates thereof, and

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

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

   g) rubberizing the textile strength members pretreated by means of a) to f) with a rubberizing mixture 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, 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 polyisocyanate is selected from the group consisting of blocked hexamethylene 1,6-diisocyanate trimer and the blocked higher homologues thereof, and blocked toluene diisocyanate trimer and the blocked higher homologues thereof, and blocked isophorone diisocyanate trimer and the blocked higher homologues thereof.
3. Process according to either of the preceding claims, characterized in that the protecting groups of the blocked polyisocyanate(s) are selected from the group consisting of ketoximes, such as preferably methyl ethyl ketoxime, and/or pyrazole derivatives, such as preferably 3,5-dimethylpyrazole, and/or esters, such as preferably malonic esters, or caprolactam or alkylated phenols.
4. Process according to any of the preceding claims, characterized in that the malein polymer has a molecular weight of 5000 to 20 000 g/mol.
5. Process according to any of the preceding claims, characterized in that the polymer in step d) is a malein-functionalized polybutadiene.
6. Process according to any of the preceding claims, characterized in that the textile strength members are polyethylene terephthalate (PET) and/or polyethylene naphthalate (PEN) and/or polybutylene terephthalate (PBT) and/or polycarbonate (PC) and/or cellulose and/or cellulose esters 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 nylon-4,6 (PA 4.6) and/or nylon-4,10 (PA 4.10) and/or nylon-6 (PA 6) and/or nylon-6,6 (PA 6.6 polyhexamethyleneadipamide) and/or nylon-6,12 (PA 6.12) and/or nylon-10,10 (PA 10.10) and/or nylon-12, 12 (PA 12.12).
7. 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.
8. Process according to any of the preceding claims, characterized in that the carbon black in the rubberizing mixture has an iodine adsorption number to ASTM D 1510 of 40 to 110 g/kg and an STSA surface area (to ASTM D 6556) of 40 to 120 m²/g.
9. Strength member ply for elastomeric products, which has been produced by at least one process according to any of Claims 1 to 8.
10. Vehicle tyre comprising, in at least one component, at least one strength member ply according to Claim 9.
11. Vehicle tyre according to Claim 10, characterized in that it includes the strength member ply at least in the carcass ply and/or the belt bandage and/or the belt and/or the bead reinforcement.