EP3083238A1

EP3083238A1 - Multilayer laminated composite for tyres

Info

Publication number: EP3083238A1
Application number: EP14809861.9A
Authority: EP
Inventors: Vincent Abad
Original assignee: Michelin Recherche et Technique SA Switzerland; Compagnie Generale des Etablissements Michelin SCA; Michelin Recherche et Technique SA France
Current assignee: Compagnie Generale des Etablissements Michelin SCA
Priority date: 2013-12-17
Filing date: 2014-12-11
Publication date: 2016-10-26
Also published as: FR3014738A1; WO2015091182A1

Abstract

The invention concerns an elastomer laminated composite for tyres, the laminated composite comprising at least three superposed polymer layers: a first layer or thermoplastic layer, consisting of a composition based on at least one thermoplastic polymer (TP), the rate of thermoplastic polymer being in a range from more than 50 to 100 % by weight; a second layer or layer of aromatic polyester block copolymer (APBC), consisting of a composition based on at least one aromatic polyester block copolymer (APBC) thermoplastic elastomer, the rate of aromatic polyester block copolymer (APBC) being in a range from more than 50 to 100 pce (parts by weight per 100 parts by weight of elastomer); the aromatic polyester block copolymer (APBC) thermoplastic elastomer of the second layer being selected from the group consisting of aromatic polyester copolymers and aliphatic polyether and mixtures thereof; and a third layer or diene layer consisting of a composition based on at least one diene elastomer, the rate of diene elastomer layer being in a range from more than 50 to 100 pce.

Description

MULTILAYER LAMINATE FOR PNEUMATIC

The present invention relates to laminates for tires comprising an adhesion layer between a diene layer and a layer consisting predominantly of a thermoplastic polymer.

In a conventional tire the various elastomeric layers consist of diene elastomer compositions, adhering to each other by interdiffusion and creation of bonds during the crosslinking of said elastomers. These layers are associated before baking (or crosslinking) to allow their adhesion. [0003] It is of interest today for tire manufacturers to use non-elastomeric polymeric layers comprising, as a polymer, predominantly thermoplastic polymers (TP) in order to benefit from the properties of these polymers. in particular for the reduction of the rolling resistance and the ease of implementation. The difficulty of using such layers, whose polymers are predominantly TP, is their adhesion to adjacent diene layers of conventional composition, and especially after the baking of the layer adjacent to the layer whose polymers are predominantly TPs.

In the field of laminates, the applicants have previously described laminates for a tire having a layer whose polymers are predominantly thermoplastic elastomers (TPE) particular. In this document, the layer consisting mainly of TPE polystyrene and polyisobutylene block copolymers, can adhere to a diene elastomer layer by the presence of an intermediate specific adhesive layer, comprising a particular thermoplastic elastomer (TPE), styrenic block copolymer and unsaturated elastomeric block.

[0006] Also, document EP 1 987 962 describes the adhesion of a so-called "thermoplastic elastomer" layer and of a diene layer, thanks to an adhesive layer comprising a particular thermoplastic elastomer (TPE), styrenic block copolymer and with unsaturated elastomeric block. In this document, the so-called "thermoplastic elastomer" layer is not a layer mainly composed of polymer thermoplastic TP but a layer composed of a mixture of thermoplastic resin nylon type 40% on the one hand and a butyl-type elastomer 60% brominated on the other hand.

In order to improve conventional tires, it would be desirable to use a layer mainly based on thermoplastic polymer (TP), whatever the nature, while ensuring the adhesion of such a layer to an adjacent diene layer. In this regard, the Applicant has surprisingly found the laminate of the invention.

The invention therefore relates to an elastomeric laminate for a tire, said laminate comprising at least three superposed layers of polymer: a first layer or thermoplastic layer, consisting of a composition based on at least one thermoplastic polymer ( TP), the thermoplastic polymer content being within a range of greater than 50 to 100% by weight;

o a second layer or layer of aromatic polyester block copolymer (CBPA), consisting of a composition based on at least one aromatic polyester block copolymer thermoplastic elastomer (CBPA), the level of aromatic polyester block copolymer (CBPA) being in a range from more than 50 to 100 phr (parts by weight per 100 parts by weight of elastomer); the aromatic polyester block copolymer thermoplastic elastomer (CBPA) of the second layer being selected from the group consisting of aromatic polyester and aliphatic polyether copolymers and mixtures thereof;

a third layer or diene layer, consisting of a composition based on at least one diene elastomer, the content of diene elastomer being in a range from more than 50 to 100 phr.

The second layer, comprising a specific CBPA provides excellent adhesion between the first and third layers of the multilayer laminate of the invention. Compared to the solutions of the prior art, the invention is very simple since it makes it possible to easily adhere a layer composed mainly of a thermoplastic polymer (TP) to a diene layer, whatever the nature of the TP, by avoiding any compatibility problems between the TP and the diene layer.

Preferably, the invention relates to a laminate as defined above, wherein the number average molecular weight of the thermoplastic polymers of the first layer is 5000 g / mol to 150 000g / mol.

Also preferably, the invention relates to a laminate as defined above, wherein the thermoplastic polymer of the first layer is selected from the group consisting of polymers having a glass transition temperature greater than 60 ° C and in the case of a semi-crystalline thermoplastic polymer, a melting temperature above 60 ° C. Preferably, the thermoplastic polymer of the first layer is chosen from the group consisting of polyurethanes, polyamides, polyesters, polyacetals, polyethers, phenylene polysulfides, polycarbonates, polysulfones, polymethylmethacrylate, polyetherimide, copolymers thermoplastics such as acrylonitrile-butadiene-styrene copolymer (ABS), and mixtures thereof. More preferably, the thermoplastic polymer further comprises carbon and hydrogen atoms, heteroatoms such as, preferably, nitrogen, oxygen, sulfur or a mixture thereof. More preferably also, the thermoplastic polymer of the first layer is selected from the group consisting of polyurethanes, polyamides, polyesters, polycarbonates, polymethylmethacrylate, acrylonitrile-butadiene-styrene copolymers (ABS), and mixtures thereof.

Preferably, the invention relates to a laminate as defined above, wherein the level of thermoplastic polymer (TP) in the composition of the first layer is in a range from 70% to 100%, more preferably from 80% to 100%). Preferably, the thermoplastic polymer is the only polymer of the first layer.

Preferably, the invention relates to a laminate as defined above, wherein the first layer does not contain a crosslinking system.

Preferably, the invention relates to a laminate as defined above, wherein the level of aromatic thermoplastic copolymer elastomer polyester aromatic (CBPA) in the composition of the second layer is in a range from 70 to 100 phr, preferably from 80 to 100 phr, more preferably 100 phr.

Preferably, the invention relates to a laminate as defined above, wherein the number-average molecular weight of CBPA is preferably between 15,000 and 500,000 g / mol.

[0016] Preferably, the invention relates to a laminate as defined above, in which the aromatic polyester block copolymer thermoplastic elastomer (CBPA) of the second layer has a glass transition temperature ("Tg") which is less than or equal to 25 ° C, more preferably less than or equal to 10 ° C. Preferably, the invention relates to a laminate as defined above, wherein the diene elastomer of the third layer is selected from the group consisting of essentially unsaturated diene elastomers, and mixtures of these elastomers. Preferably, the diene elastomer of the third layer is chosen from the group consisting of homopolymers obtained by polymerization of a conjugated diene monomer having from 4 to 12 carbon atoms, the copolymers obtained by copolymerization of one or more conjugated dienes. between them or with one or more vinyl aromatic compounds having 8 to 20 carbon atoms, and mixtures thereof. Preferably, the diene elastomer of the third layer is chosen from the group consisting of polybutadienes, synthetic polyisoprenes, natural rubber, butadiene copolymers, isoprene copolymers and mixtures of these elastomers.

Preferably, the invention relates to a laminate as defined above, wherein the third layer comprises a reinforcing filler. Preferably, the reinforcing filler is carbon black and / or silica, and preferably the majority reinforcing filler is a carbon black. The invention also relates to a tire comprising a laminate as defined above.

In addition, the invention also relates to the use in a pneumatic object of a laminate as defined above.

The invention relates more particularly to the laminates as defined above, used in tires intended to equip vehicles without engines such as the bicycles, or motor-vehicles of the tourism type, SUV ("Sport Utility Vehicles"), two-wheeled vehicles (in particular motorcycles), planes, such as industrial vehicles chosen from vans, "heavy vehicles" - that is to say metros, buses, road transport vehicles (trucks, tractors, trailers), off-the-road vehicles such as agricultural or civil engineering vehicles; other transport or handling vehicles.

The invention as well as its advantages will be readily understood in light of the description and examples of embodiments which follow.

DETAILED DESCRIPTION OF THE INVENTION In the present description, unless expressly indicated otherwise, all the percentages (%) indicated are percentages by weight.

For the purposes of the present invention and in a manner known to those skilled in the art, the term polymer denotes a molecule comprising monomers (of the same nature or of different natures) polymerized. This term brings together polymers that may differ in their physical properties such as thermoplastic polymers and elastomers. Within the meaning of the present invention, the elastomers include diene elastomers, which are well known, and thermoplastic elastomers. These are therefore part of the family of elastomers, and for the purposes of the present invention, are not considered as thermoplastic polymers. These distinctions being given, we find in the laminate of the invention thermoplastic polymers, diene elastomers and special thermoplastic elastomers, selected from aromatic polyester block copolymers (CBPA).

The term "phr", well known to those skilled in the art, means within the meaning of the present patent application, part by weight per hundred parts of elastomer, that is to say here, thermoplastic elastomers and diene elastomers combined.

On the other hand, any range of values designated by the expression "between a and b" represents the range of values from more than a to less than b (that is to say terminals a and b excluded). ) while any range of values designated by the expression "from a to b" signifies the range of values from a to b (that is to say, including the strict limits a and b). For the purposes of the present invention, it is specified that in the present patent application, the term "thermoplastic layer" a polymeric layer comprising, relative to the total weight of all polymers, a majority (that is, at least 50%) of thermoplastic polymer; and denominated "diene layer" an elastomeric layer comprising, predominantly by weight (that is to say at least 50%), diene elastomers. Also, a "CBPA layer" is a layer consisting of a composition based on at least one aromatic polyester block copolymer thermoplastic elastomer (CBPA), the content of aromatic polyester block copolymer thermoplastic elastomer being in a range from from more than 50 to 100 pce.

The laminate according to the invention has excellent adhesion between a thermoplastic layer (first layer) and a diene layer (third layer) thanks to the presence of a layer CBPA (second layer), named for the need for clarity of the invention first, second and third layers (or respectively, thermoplastic layer, CBPA layer and diene layer).

The details of the invention will be explained below, by the description of the different layers of the laminate, and by the description of the adhesion between the layers of the laminate according to the invention.

As indicated above, the multilayer laminate of the invention therefore has the essential feature of comprising at least three superimposed layers of polymer: a first layer or thermoplastic layer, consisting of a composition based on at least one polymer thermoplastic (TP), the level of thermoplastic polymer being in a range from more than 50 to 100% by weight;

o a second layer or layer of aromatic polyester block copolymer

(CBPA), consisting of a composition based on at least one aromatic polyester block copolymer thermoplastic elastomer (CBPA), the content of aromatic polyester block copolymer (CBPA) being in a range from more than 50 to 100 pce (parts by weight per 100 parts by weight of elastomer); a third layer or diene layer, consisting of a composition based on at least one diene elastomer, the content of diene elastomer being in a range from more than 50 to 100 phr.

The multilayer laminate according to the invention therefore has the essential feature of being provided with at least three layers called "thermoplastic layer", "CBPA layer" and "diene layer" of different formulations. Nevertheless, said layers of said multilayer laminate may comprise, in addition to constituents which are specific thereto, optional constituents such as those defined below and in particular plasticizers or reinforcing fillers.

I- First layer of the multilayer laminate or thermoplastic layer

The first layer of the laminate, or thermoplastic layer consists of a composition based on at least one thermoplastic polymer (TP), the level of thermoplastic polymer being in a range from more than 50 to 100% in We will use for the definition of thermoplastic polymers the characteristic of glass transition temperature (Tg, measured according to ASTM D3418) of the thermoplastic polymer. This characteristic is well known to those skilled in the art. It allows in particular to choose the temperature of industrial implementation (transformation). In the case of an amorphous polymer, the processing temperature is chosen substantially higher than the Tg of the thermoplastic polymer. In the specific case of a semicrystalline polymer, a melting point can be observed, then greater than the glass transition temperature. In this case, it is rather the melting temperature (Tf) that allows to choose the implementation temperature of the polymer in question. Thus, later, when we talk about "Tg (or Tf, if any)", we must consider that this is the temperature used to choose the temperature of implementation.

For the purposes of the invention, the thermoplastic layer comprises one or more thermoplastic polymer (s) preferably having a Tg (or Tf, where appropriate) greater than or equal to 60 ° C. and consisting of ) from polymerized monomers. Preferably, this thermoplastic polymer has a Tg (or Tf, where appropriate) in a range of 60 ° C to 250 ° C. Preferably, the Tg (or Tf, if any) of this thermoplastic polymer is preferably 70 ° C to 200 ° C, more preferably 80 ° C to 180 ° C.

Thermoplastic polymers having a Tg (or Tf, if appropriate) greater than or equal to 60 ° C may be made from polymerized monomers of various kinds, in particular they may constitute the following polymers or their mixtures: polyurethanes ;

polyamides;

polyesters, for example polyterephthalates;

polyacetals;

polyethers (polyethylene oxide, polyphenylene ether);

phenylene polysulfides;

polycarbonates;

polysulfones;

polymethyl methacrylate;

polyetherimide;

thermoplastic copolymers such as acrylonitrile-butadiene-styrene copolymer (ABS).

Also preferably, the thermoplastic polymer further comprises carbon and hydrogen atoms, heteroatoms such as, preferably, nitrogen, oxygen, sulfur or a mixture thereof.

Thus, preferably from the monomers listed above, the thermoplastic polymers having a Tg (or Tf, if appropriate) greater than or equal to 60 ° C are constituted from polymerized monomers of various natures, in particular, they may constitute the following polymers or their mixtures: polyurethanes;

polyamides;

polyesters, such as for example polyterephthalates and in particular polybutylene terephthalate;

polycarbonates;

polymethyl methacrylate;

acrylonitrile-butadiene-styrene copolymers (ABS). According to a variant of the invention, the polymerized monomer as defined above may be copolymerized with at least one other monomer so as to form a thermoplastic polymer having a Tg (or Tf, if appropriate) as defined above.

By way of illustration, this other monomer capable of copolymerizing with the polymerized monomer may be chosen from diene monomers, more particularly conjugated diene monomers having 4 to 14 carbon atoms, and vinylaromatic-type monomers having from 8 to 20 carbon atoms, as defined in the part relating to the elastomeric polymer.

According to the invention, the thermoplastic polymers have a number-average molecular weight ("Mn") ranging from 5,000 g / mol to 150,000 g / mol, so as to give the TP good mechanical properties, which are sufficient and compatible. with the use of multilayer laminate tire.

The number average molecular weight (Mn) of the thermoplastic polymer is determined by any technique known to those skilled in the art and in particular, in a known manner, by steric exclusion chromatography (SEC). The sample is solubilized beforehand in a suitable solvent known to those skilled in the art, at a concentration of approximately 2 g / l; then the solution is filtered on 0.45 μιη porosity filter before injection. The apparatus used is a "WATERS alliance" chromatographic chain. The elution solvent is, for example, for a polybutylene terephthalate hexafluoroisopropanol with sodium trifluoroactetate salt at a concentration of 0.02 M, the flow rate of 0.5 ml / min, the temperature of the system of 35 ° C and the analysis time of 90 min. It uses a set of three Phenomenex columns in series of trade names "Phenogel" (pore size: 5 10 ^A, 10 ^A 4, 10 ^A 3 A). The injected volume of the solution of the polymer sample is 100 μΐ. The detector is a differential refractometer "WATERS 2410" and its associated chromatographic data exploitation software is the "EMPOWER" system. The calculated average molar masses relate to a calibration curve made with PMMA (polymethyl methacrylate) standards. The conditions are adaptable by those skilled in the art.

The thermoplastic polymer may also consist of several thermoplastic polymers as defined above. For example, TP is a polymer selected from the group consisting of polycarbonates, polyurethanes (PU), polyethers, polyesters (especially polyterephthalates), polyamides, thermoplastics such as acrylonitrile-butadiene-copolymer. styrene (ABS). It is also possible that the TP given as an example above are mixed together in the thermoplastic layer of the multilayer laminate according to the invention.

Examples of thermoplastic polymer commercially available include polybutylene terephthalate "Ultradur B4500" marketed by BASF.

As a first layer, thermoplastic, is used a composition comprising more than 50 phr of thermoplastic polymer as defined above, with all the preferences previously expressed.

The thermoplastic layer described above could optionally comprise other polymers, such as elastomers in a minor amount (at most 50% of the total mass of polymer). Preferably, the level of thermoplastic polymer (TP) in the first layer is in a range from 70% to 100%, in particular in a range from 80% to 100%.

However, according to a particularly preferred embodiment, the thermoplastic polymer (s) (TP) are the only polymers present in the thermoplastic layer; accordingly, in such a case, at a rate equal to 100% of the total mass of the polymers.

II- Second layer of the multilayer laminate or CBPA layer

The second layer of the laminate, or aromatic polyester block copolymer layer (CBPA) consists of a composition based on at least one aromatic polyester block copolymer thermoplastic elastomer (CBPA), the block copolymer content aromatic polyester (CBPA) being in a range from more than 50 to 100 phr (parts by weight per hundred parts by weight of elastomer). The aromatic polyester block copolymer thermoplastic elastomer (CBPA) of the second layer is selected from the group consisting of aromatic polyester and aliphatic polyether copolymers and mixtures thereof.

Thermoplastic elastomers (abbreviated as "TPE") have an intermediate structure between thermoplastic polymers and elastomers. They are block copolymers, made up of rigid, thermoplastic blocks, connected by flexible blocks, elastomers.

By convention, this aromatic polyester block copolymer thermoplastic elastomer (TPE) is abbreviated CBPA in the present application.

The number-average molecular weight (denoted by Mn) of the CBPA is preferably between 15,000 and 500,000 g / mol, more preferably between 20,000 and 300,000 g / mol. Below the minima indicated, the cohesion between the elastomer chains of the CBPA, in particular because of its possible dilution (in the presence of an extension oil), is likely to be affected; on the other hand, an increase in the temperature of use may affect the mechanical properties, including the properties at break, resulting in reduced performance "hot". Moreover, a mass Mn that is too high can be penalizing for the implementation. Thus, it has been found that a value in the range of 20,000 to 50,000 g / mol is particularly well suited, particularly to the use of CBPA in an adhesive composition for multilayer tire laminate. The number average molecular weight (Mn) of CBPA is determined by any technique known to those skilled in the art and in particular, in a known manner, by steric exclusion chromatography (SEC). The sample is solubilized beforehand in a suitable solvent at a concentration of approximately 2 g / l; then the solution is filtered on 0.45 μιη porosity filter before injection. The apparatus used is a "WATERS alliance" chromatographic chain. For example, in the case of COPE-type CBPAs, the elution solvent is hexafluoroisopranol with sodium trifluoroactetate salt at a concentration of 0.02 M, the flow rate of 0.5 ml / min, the temperature of the system of 35 ° C and the analysis time of 90 min. It uses a set of three Phenomenex columns in series of trade names "Phenogel" (pore size: 5 10 ^A, 10 ^A 4, 10 ^A 3 A). The injected volume of the solution of the polymer sample is 100 μΐ. The detector is a differential refractometer "WATERS 2410" and its Associated Chromatographic Data Operating Software is the "EMPOWER" system. The calculated average molar masses relate to a calibration curve made with PMMA (polymethyl methacrylate) standards. The conditions are adaptable by those skilled in the art. The value of the polydispersity index Ip (booster: Ip = Mw / Mn with Mw weight average molecular weight and Mn average molecular weight) of the TPE is preferably less than 3; more preferably less than 2 and even more preferably less than 1.5.

In the present application, when reference is made to the glass transition temperature of CBPA, it is the Tg relative to the elastomeric block. The CBPA preferably has a glass transition temperature ("Tg") which is preferably less than or equal to 25 ° C, more preferably less than or equal to 10 ° C. A value of Tg higher than these minima can reduce the performance of the multilayer laminate during use at very low temperature; for such use, the Tg of the TPE is more preferably still less than or equal to -10 ° C. Also preferentially, the Tg of CBPA is greater than -100 ° C.

In known manner, the CBPAs have two glass transition temperature peaks (Tg, measured according to ASTM D3418), the lowest temperature being relative to the elastomer portion of the CBPA, the highest temperature being relative to the thermoplastic part of the CBPA, that is to say the aromatic polyester block. Thus, the soft blocks of the CBPAs, of aliphatic polyether, are defined by a Tg lower than the ambient temperature (25 ° C.), whereas the rigid blocks of aromatic polyester have a Tg greater than 60 ° C.

The CBPA have, by their thermoplastic blocks, a melting temperature (Tf) (measured by DSC) greater than 120 ° C. Preferably for the purposes of the invention, preference will be given to the CBPA layer thermoplastic elastomers CBPA whose Tf is between 140 and 210 ° C.

CBPAs are copolymers comprising a large number of blocks (more than 30, typically 50 to 500), these blocks preferably having low masses, for example 500 to 5000 g / mol, these CBPA are called multiblocks and are a sequential elastomeric block - thermoplastic block that repeats itself. By aromatic polyester block copolymer thermoplastic elastomers (CBPA) is meant block copolymer thermoplastic elastomer in which the rigid blocks are essentially (that is to say more than 80% by weight, preferably greater than 90% by weight). % by weight and more preferably greater than 99% by weight) made of aromatic polyester (that is to say one or more aromatic polyester (s)).

Among the CBPA, block copolymers aromatic polyester and polyether, ie the family of block copolymers polyester and polyether (abbreviated "COPE"), can be made for example COPE marketed by the company TOYOBO such as "COPE P30B", "COPE P40B", "COPE P40H" or "COPE P55B". There may also be mentioned the COPE TPE marketed by the company DSM under the name "Arnitel", or by the company Dupont under the name "Hytrel", or by the company Ticona under the name "Riteflex".

If any other elastomers (non-CBPA) are used in the composition of the CBPA layer, the CBPA elastomer (s) constitute the majority fraction by weight; they then represent at least 50%, preferably at least 65%, preferably at least 70% by weight, more preferably at least 80% by weight of all the elastomers present in the elastomer composition. Also preferably, the CBPA elastomer or elastomers represent at least 95% (in particular 100%) by weight of all the elastomers present in the elastomer composition of the CBPA layer. Thus, the total amount of CBPA elastomer is in a range that varies from more than 50 to 100 phr, preferably from 65 to 100 phr, preferably from 70 to 100 phr, and in particular from 80 to 100 phr. Also preferably, the composition contains from 95 to 100 phr of CBPA elastomer. The CBPA elastomer or elastomers are preferably the single elastomer (s) of the CBPA layer. III- Third layer of the multilayer laminate or diene layer

As a third layer is used, an elastomeric composition whose essential characteristic is to have a diene elastomer content in a range from 50 to 100 phr. Preferably, the level of diene elastomer (that is to say the total level if there are several) is preferably in a range from 55 to 100 phr and more preferably from 60 to 100 phr. Thus, the diene layer of the multilayer laminate according to the invention comprises at least one (that is to say one or more) diene elastomer, which can be used alone, or in a blend with at least one (c '). that is, one or more other diene elastomer (or rubber). This layer may optionally also contain all the usual constituents of the diene compositions such as fillers, plasticizers, additives and crosslinking agents, which are described below as optional components possibly common to the three layers of the laminate of the invention.

By elastomer or "diene" rubber, must be understood in a known way (one means one or more) elastomer derived at least in part (ie a homopolymer or a copolymer) of monomers dienes (monomers carrying two double bonds carbon - carbon, conjugated or not).

These diene elastomers can be classified in two categories: "essentially unsaturated" or "essentially saturated".

The term "essentially unsaturated" is generally understood to mean a diene elastomer derived at least in part from conjugated diene monomers having a proportion of units or units of diene origin (conjugated dienes) which is greater than 15% (% by weight). mole). In the category of "essentially unsaturated" diene elastomers, the term "highly unsaturated" diene elastomer is particularly understood to mean a diene elastomer having a content of units of diene origin (conjugated dienes) which is greater than 50%. Thus, diene elastomers such as certain butyl rubbers or copolymers of dienes and alpha olefins EPDM type can be described as "essentially saturated" diene elastomers (low or very low diene origin ratio). low, always less than 15>).

These definitions being given, the term "diene elastomer" is understood to mean, whatever the category above, which may be used in the compositions according to the invention:

(a) any homopolymer obtained by polymerization of a conjugated diene monomer having from 4 to 12 carbon atoms; (b) any copolymer obtained by copolymerization of one or more conjugated dienes with each other or with one or more vinyl aromatic compounds having from 8 to 20 carbon atoms;

(c) a ternary copolymer obtained by copolymerization of ethylene, an α-olefin having 3 to 6 carbon atoms with a non-conjugated diene monomer having from 6 to 12 carbon atoms, for example elastomers obtained from ethylene, propylene with a nonconjugated diene monomer of the aforementioned type such as in particular 1,4-hexadiene, ethylidene norbornene, dicyclopentadiene;

(d) a copolymer of isobutene and isoprene (butyl diene rubber), as well as the halogenated versions, in particular chlorinated or brominated, of this type of copolymer.

Any type of diene elastomer can be used in the invention. When the composition contains a vulcanization system, essentially unsaturated elastomers, especially types (a) and (b) above, are preferably used for the manufacture of the multilayer laminate according to the present invention. As conjugated dienes 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-di (C 1 -C 5) alkyl-1,3-butadienes, such as for example 2,3-dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl 1,3-butadiene, aryl-1,3-butadiene, 1,3-pentadiene, 2,4-hexadiene. Suitable vinylaromatic compounds are, for example, styrene, ortho-, meta-, para-methylstyrene, the "vinyl-toluene" commercial mixture, para-tertiarybutylstyrene, methoxystyrenes, chlorostyrenes, vinylmesitylene, divinylbenzene, vinylnaphthalene.

The copolymers may contain between 99% and 20% by weight of diene units and between 1% and 80% by weight of vinylaromatic units. The elastomers may have any microstructure which is a function of the polymerization conditions used, in particular the presence or absence of a modifying and / or randomizing agent and the amounts of modifying and / or randomizing agent used. The elastomers may for example be prepared in dispersion or in solution; they may be coupled and / or starred or functionalized with a coupling agent and / or starring or functionalization. For coupling with carbon black, there may be mentioned for example functional groups comprising a C-Sn bond or amino functional groups such as benzophenone for example; for coupling to a reinforcing inorganic filler such as silica, mention may be made, for example, of silanol or polysiloxane functional groups having a silanol end (as described, for example, in FR 2,740,778 or US Pat. No. 6,013,718), alkoxysilane groups (such as as described for example in FR 2,765,882 or US 5,977,238), carboxylic groups (as described for example in WO 01/92402 or US 6,815,473, WO 2004/096865 or US 2006/0089445) or groups polyethers (as described for example in EP 1 127 909 or US Pat. No. 6,503,973). As other examples of functionalized elastomers, mention may also be made of elastomers (such as SBR, BR, NR or IR) of the epoxidized type.

IV- Optional constituents of multilayer laminate layers

Nanometric (or reinforcing) and micrometric (or non-reinforcing) charges

The elastomers and polymers described above are sufficient in themselves to be usable multilayer laminate according to the invention, nevertheless a reinforcing filler can be used in one or more of the compositions, and in particular in the diene layer of the laminate of the invention. 'invention.

When a reinforcing filler is used, it is possible to use any type of filler usually used for the manufacture of tires, for example an organic filler such as carbon black, an inorganic filler such as silica, or a cutting of these two types of filler, including a cut of carbon black and silica.

When an inorganic reinforcing filler is used, it is possible for example to use, in known manner, at least one bifunctional coupling agent (or bonding agent) intended to ensure a sufficient chemical and / or physical connection between the inorganic filler (surface of its particles) and the elastomer, in particular organosilanes or bifunctional polyorganosiloxanes.

In the same way, the composition of the layers of the multilayer laminate of the invention may contain one or more micrometric charges, called "non-reinforcing" or inert, such as lamellar fillers known to those skilled in the art. . Various additives

The multilayer laminate of the invention may further comprise the various additives usually present in the tire elastomeric layers known to those skilled in the art. For example, one or more additives chosen from protective agents such as antioxidants or antiozonants, anti-UV agents, the various agents of implementation or other stabilizers, or the promoters able to promote the adhesion to the rest of the structure will be chosen. of the tire. Preferably, the thermoplastic and CBPA layers of the multilayer laminate do not contain all these additives at the same time and preferentially in some cases, the thermoplastic and aromatic polyester block copolymer (CBPA) layers of the multilayer laminate do not contain any antiozonant, anti-blocking agents. UV, no processing agent, no stabilizer, no adhesion promoter.

Also and optionally, the composition of the layers of the multilayer laminate of the invention may contain a crosslinking system known to those skilled in the art. Preferably, the composition of the "thermoplastic" and "CBPA" layers of the multilayer laminate of the invention do not contain a crosslinking system.

Optionally also, the composition of the layers of the multilayer laminate of the invention may contain a plasticizer, such as an extender oil (or plasticizing oil) or a plasticizing resin whose function is to facilitate the implementation. multilayer laminate, particularly its integration with the tire by a lowering of the module and an increase in tackifiant power.

V- Adhesion of layers of laminate

It was found that the adhesion of the first layer to the third layer in the laminate of the invention is significantly improved with respect to the adhesion of a TP layer, the type of the first layer of the laminate of the invention, to a diene layer of the type of the third layer of the laminate, thanks to the presence of the CBPA layer, as adhesion layer. VI- Use of the laminate, in particular in a tire

The laminate of the invention can be used in any type of article. It is particularly well suited for use in a pneumatic tire, finished tire product or semi-finished tire, rubber, especially in a tire for a motor vehicle such as a vehicle type two-wheel, tourism or industrial, or not automobile such as bicycle.

The laminate of the invention can be manufactured by combining the layers of the laminate before baking, or even after baking. More specifically, since the thermoplastic and CBPA layers do not require firing, they can be associated with the diene layer of the laminate of the invention before or after the firing of this diene layer, which requires cooking before being used in pneumatic form. .

The multilayer laminate of the invention is advantageously used in tires of all types of vehicles, especially in tires for passenger vehicles likely to drive at very high speeds or tires for industrial vehicles such as trucks.

VII- Preparation of the laminate

The multilayer laminate of the invention is prepared according to the methods known to those skilled in the art, for example by separately preparing the three layers of the laminate, and then combining the thermoplastic layer with the diene layer via of the CBPA layer, before firing of the diene layer. The combination of the thermoplastic layer and the diene layer via the CBPA layer can be done under the action of heat and possibly pressure.

Preparation of the thermoplastic layer

The thermoplastic layer of the multilayer laminate of the invention is prepared conventionally, for example, by incorporating the various components into a twin-screw extruder, so as to achieve the melting of the matrix and incorporation of all the ingredients. , then use of a flat die for producing the thermoplastic layer with the desired target thickness. More generally, the formatting of the TP can be made by any method known to those skilled in the art: extrusion, calendering, extrusion blow molding, injection, cast film.

Preparation of the Aromatic Polyester Block Copolymer (CBPA) Layer The CBPA layer of the multilayer laminate of the invention is prepared conventionally, for example, by incorporating the various components into a twin-screw extruder, so that perform the melting of the matrix and incorporation of all the ingredients, then use a flat die to achieve the thermoplastic layer with the desired target thickness. More generally, the formatting of the CBPA may be made by any method known to those skilled in the art: extrusion, calendering, extrusion blow molding, injection, cast film.

Preparation of the diene layer

The diene layer of the multilayer laminate of the invention is prepared in suitable mixers, using two successive preparation phases according to a general procedure well known to those skilled in the art: a first phase of work or thermo-mechanical kneading (sometimes referred to as a "non-productive" phase) at a high temperature, up to a maximum temperature of between 130 ° C and 200 ° C, preferably between 145 ° C and 185 ° C, followed by a second phase of work mechanical (sometimes called a "productive" phase) at a lower temperature, typically less than 120 ° C, for example between 60 ° C and 100 ° C, finishing phase during which is incorporated the crosslinking system or vulcanization.

According to a preferred embodiment of the invention, all the basic constituents of the compositions of the invention, with the exception of the vulcanization system, such as any fillers and additives, are incorporated in an intimate manner by mixing, with the diene elastomer during the first so-called non-productive phase, that is to say that is introduced into the mixer and which is kneaded thermomechanically, in one or more steps, at least these different basic constituents until the maximum temperature is between 130 ° C and 200 ° C, preferably between 145 ° C and 185 ° C. For example, the first phase (non-productive) is conducted in a single thermomechanical step during which is introduced into a suitable mixer such as a conventional internal mixer, all the necessary constituents, the possible additional coating or processing agents and other miscellaneous additives, with the exception of the vulcanisation system. The total mixing time, in this non-productive phase, is preferably between 1 and 15 min. After cooling the mixture thus obtained during the first non-productive phase, the vulcanization system is then incorporated at low temperature, generally in an external mixer such as a roller mixer; the whole is then mixed (productive phase) for a few minutes, for example between 2 and 15 min.

The final composition thus obtained is then calendered, for example in the form of a layer denominated in the present invention diene layer.

Preparation of the laminate The multilayer laminate of the invention is prepared by combining the thermoplastic layer with the diene layer via the CBPA layer, before firing the diene layer. This consists of placing the CBPA layer on the diene layer, then the thermoplastic layer on the CBPA layer to form the laminate of the invention and then to proceed with the baking of the laminate or tire provided with said laminate. In order for the adhesion to be optimal, it is preferable that the temperature at the interface is greater than the operating temperature of the TP and the CBPA, itself higher than the glass transition temperature (Tg) and, in the case of a semi-crystalline thermoplastic block, at the melting temperature (Tf) of said TP and CBPA, possibly associated with the application of pressure.

VIII- Examples

Preparation of examples

The multilayer laminate examples of the invention are prepared as indicated above. Description of the tests used

The multilayer laminate examples of the invention are tested as to the adhesion of the thermoplastic layer to the diene layer in the presence (examples of the invention) or absence (control) of the adhesive layer CBPA according to a test called peel. The peel test pieces are made by contacting the following layers of the laminate: diene layer reinforced with a fabric (so as to limit the deformation of said layers under tension) / adhesive layer consisting of CBPA / TP layer / adhesive layer constituted of CBPA / diene layer reinforced with a tissue. In this symmetrical stack, a break primer is inserted between the TP layer and one of the adjacent CBPA layers.

The laminate specimen once assembled is brought to 180 ° C under pressure for 10 minutes. Strips 30 mm wide were cut with a cutter. Both sides of the fracture primer were then placed in the jaws of an Intron ^® brand traction machine. The tests are carried out at ambient temperature and at a tensile speed of 100 mm / min. The tensile forces are recorded and these are standardized by the width of the specimen. A force curve is obtained per unit of width (in N / mm) as a function of the displacement of the moving beam of the traction machine (between 0 and 200 mm). The value of adhesion retained corresponds to the initiation of the rupture within the specimen and therefore to the maximum value of this curve. The performance of the examples are standardized with respect to the control free of the adhesive CBPA layer (base 100). The adhesion value is supplemented by the fracture facies or fracture type: an adhesive facies means that the adhesive interface was the breaking point whereas a cohesive facies reveals a lower material cohesion (diene layer or TP). the adhesive holding of the interface, with a break point inside one of the layers.

Example of laminate

Thermoplastic layer, diene layer and CBPA adhesion layer compositions were prepared, assembled and tested as previously indicated. The compositions as well as their associations and adhesion results are presented below. The so-called thermoplastic layer (Layer A) is a layer consisting solely of polybutene terephthalate "Ultradur B4500" marketed by BASF, the adhesive layer CBPA (Layer B) in the example is a layer consisting solely of COPE P30B, copolymer of aromatic polyester and aliphatic polyether marketed by TOYOBO and the diene layer (Layer C) is a layer whose composition is shown in Table 1 below.

Table 1

Rate component in pce

BR (1) 15

SBR (2) 85

N234 (3) 5

Sil 160MP (4) 70

liquid silane (5) 6

Oil (6) 2

Resin (7) 15

Antioxidant (8) 2

DPG (9) 1.5

Stearic acid (10) 2

ZnO (l l) 1

CBS (12) 2

Sulfur 1

(1) Ollybutadiene BR with 4% 1,2- and 93% 1,4-cis (Tg = -106 ° C)

(2) SBR copolymer solution of styrene and butadiene with 26.5% of styrene units and 24% of 1,2-butadiene modifications (Tg of -48 ° C.)

(3) ASTM N347 or ASTM N683 grade marketed by Cabot

(4) 160 MP silica, "Zeosil 1165MP" from Rhodia

(5) "Dynasilan Octeo", from Degussa

(6) MES oil "Catenex SNR" marketed by Shell

(7) Resin C5 / C9 "Escorez 2173" from the company Exxon

(8) N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine "6-PPD" from Flexsys (9) Diphenylguanidine ("Perkacit" DPG from Flexsys)

(10) Stearin ('Pristerene 4931' from Uniqema)

(11) Zinc oxide (industrial grade - Umicore company)

(12) N-cyclohexyl-2-benzothiazol sulfenamide "Santocure CBS" from the company Flexsys

The laminates assembled for the purposes of the test are of two types: a three-layer laminate according to the invention and a two-layer laminate, not comprising the adhesion layer (CBPA layer) as a control laminate the effect of the adhesion layer:

- A / C: two-layer control only, without the adhesive layer (CBPA) and, - A / B / C: according to the invention with three layers, a thermoplastic layer, a CBPA adhesive layer and a diene layer.

Table 2

The results presented in Table 2 demonstrate an improvement of the adhesive performance of the laminate by more than a factor of 2 when using the laminate of the invention, compared to the situation in which the thermoplastic layer is directly exposed. in contact with the diene layer, without an adhesive layer.

Claims

An elastomeric tire laminate, said laminate comprising at least three superimposed layers of polymer:

a first layer, or thermoplastic layer, consisting of a composition based on at least one thermoplastic polymer (TP), the content of thermoplastic polymer being in a range from more than 50 to 100% by weight;

a second layer, or layer of aromatic polyester block copolymer (CBPA), consisting of a composition based on at least one aromatic polyester block copolymer thermoplastic elastomer (CBPA), the level of aromatic polyester block copolymer (CBPA) ) being in a range from more than 50 to 100 phr (parts by weight per 100 parts by weight of elastomer); the aromatic polyester block copolymer thermoplastic elastomer (CBPA) of the second layer being selected from the group consisting of aromatic polyester and aliphatic polyether copolymers and mixtures thereof;

a third layer, or diene layer, consisting of a composition based on at least one diene elastomer, the content of diene elastomer being in a range from more than 50 to 100 phr.

The laminate of claim 1, wherein the number average molecular weight of the thermoplastic polymers of the first layer is 5,000 g / mol to 150,000 g / mol.

A laminate according to any one of the preceding claims wherein the thermoplastic polymer of the first layer is selected from the group consisting of polymers having a glass transition temperature above 60 ° C and, in the case of a thermoplastic polymer semi-crystalline, a melting temperature above 60 ° C.

A laminate according to any one of the preceding claims wherein the thermoplastic polymer of the first layer is selected from the group consisting of polyurethanes, polyamides, polyesters, polyacetals, polyethers, phenylene polysulfides, polycarbonates, polysulfones, polymethylmethacrylate, polyetherimide, thermoplastic copolymers such as acrylonitrile-butadiene-styrene copolymer (ABS), and mixtures thereof.

A laminate according to any one of the preceding claims wherein the thermoplastic polymer further comprises carbon and hydrogen atoms, heteroatoms such as, preferably, nitrogen, oxygen, sulfur or a mixture of these latter.

6. A laminate according to any one of the preceding claims wherein the thermoplastic polymer of the first layer is selected from the group consisting of polyurethanes, polyamides, polyesters, polycarbonates, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymers ( ABS), and mixtures thereof.

A laminate according to any one of the preceding claims, wherein the level of thermoplastic polymer (TP) in the composition of the first layer is within a range of 70% to 100%.

The laminate of claim 7, wherein the level of thermoplastic polymer (TP) in the composition of the first layer is within a range of 80% to 100%.

The laminate of claim 8, wherein the thermoplastic polymer is the sole polymer of the first layer.

10. A laminate according to any one of the preceding claims, wherein the first layer does not contain a crosslinking system.

A laminate according to any one of the preceding claims, wherein the content of aromatic polyester block copolymer thermoplastic elastomer (CBPA) in the composition of the second layer is within a range of 70 to 100 phr.

12. A laminate according to claim 11, wherein the content of aromatic polyester block copolymer thermoplastic elastomer (CBPA) in the composition of the second layer is in a range from 80 to 100 phr.

13. A laminate according to claim 12, wherein the content of aromatic polyester block copolymer thermoplastic elastomer (CBPA) in the composition of the second layer is 100 phr.

14. Laminate according to one of the preceding claims, wherein the number average molecular weight of CBPA is preferably between 15,000 and 500,000 g / mol.

Laminate according to one of the preceding claims, wherein the aromatic polyester block copolymer thermoplastic elastomer (CBPA) of the second layer has a glass transition temperature ("Tg") which is less than or equal to 25 ° C, more preferably less than or equal to 10 ° C.

16. A laminate according to one of the preceding claims wherein the diene elastomer of the third layer is selected from the group consisting of essentially unsaturated diene elastomers, and mixtures of these elastomers.

17. A laminate according to claim 16 wherein the diene elastomer of the third layer is selected from the group consisting of homopolymers obtained by polymerization of a conjugated diene monomer having from 4 to 12 carbon atoms, the copolymers obtained by copolymerization d one or more dienes conjugated to one another or to one or more vinyl aromatic compounds having 8 to 20 carbon atoms, and mixtures thereof.

The laminate of claim 17, wherein the diene elastomer of the third layer is selected from the group consisting of polybutadienes, synthetic polyisoprenes, natural rubber, butadiene copolymers, isoprene copolymers and blends. of these elastomers.

Laminate according to any one of the preceding claims, wherein the third layer comprises a reinforcing filler.

The laminate of claim 19, wherein the reinforcing filler is carbon black and / or silica.

The laminate of claim 20, wherein the majority reinforcing filler is a carbon black.

22. A tire comprising a laminate according to any one of the preceding claims.

23. Use in a pneumatic object of a laminate according to any one of claims 1 to 21.