Typical shaped articles are selected from hoses, such as coolant hoses, and tubes.

Background of the Invention Hose joint assemblies, in particular those assemblies used in fluid circuits for automotive and/or industrial processes, operate in exceedingly harsh environments. Factors including varying pressures and temperatures at dif- ferent points of an assembly, varying diameters of different hoses in a par- ticular circuit, as well as chemical exposure result in the need for highly rig- orous hose assemblies. Therefore, it is difficult if not impossible to effi- ciently and economically manufacture large numbers of permanently shaped rubber hoses. Many previous attempts for manufacturing such assemblies have resulted in products that were not entirely reliable against leakage in use. After assembling engines and car bodies a connection between the dif- ferent aggregates has to be accomplished. Due to the minor amount of space under the hood of an automotive, the rubber hoses used for the con- nection of engine, cooler and radiator, etc. have to be individually adapted to the various engine and car body types. The shape may often be very complex dependent on the available space under the vehicle hood.

Consequently, there is a strong need for hoses, in particular coolant hoses, having a complex shape and a good resistance to the rough environmental conditions in applications under the hood.

A further object of the present invention is the provision of coolant hoses that can easily be recycled and are of lower weight compared to hoses known in the prior art.

Additionally, a process for manufacturing of said hoses in an individual and economic manner, in particular in view of the production of limited quanti- ties is desired.

As a material for the manufacturing of coolant hoses thermoplastic poly- mers, such as thermoplastic elastomers have been established in the last few years. Thermoplastic elastomers (TPE) combine both thermoplastic and elastic properties. Compared to the use of vulcanizable, non-thermoplastic rubbers, a separate vulcanizing step that affords a high temperature treat- ment of the shaped unvulcanized hoses is not necessary anymore.

In order to achieve the desired resistance against high temperatures and working pressures a reinforcement of the thermoplastic elastomers is nec- essary.

For several reasons the use of short fiber reinforced thermoplastic elastom- ers is mandatory for producing shaped articles, such as for permanently curved hoses, by the process according to the present invention: The reinforcement must be present in the stock before it is extruded.

An extrudate without any fiber reinforcement would collapse after leaving the die orifice.

The dispersed short fibers provide the hot extruded shaped article with structural integrity thus minimizing shape distortion before SD- lidification of the extrudate.

- The fiber reinforcement reduces the expansion of, for instance, a ve- hicle radiator hose during its use under elevated temperatures and pressures.

However, the inherent characteristic of the polyolefinic thermoplastic elas- tomer blends is its non-reactive surface. To achieve adhesion between the reinforcing fibers and the embedding thermoplastic matrix the reinforcing fibers have to be modified with a polar material in order to be cohesively bondable to polar substrates.

Due to their low surface tension (28-30 dyns/cm) polyolefinic thermoplastic elastomer blends as well as polyolefinic materials, such as polyethylene or polypropylene, cannot adhere directly to more polar substrates, such as polyamid, polyester, metal and glass.

Various techniques, such as chemical surface treatment, compound modifi- cation via polar ingredients, surface oxidation or reducing surface tension of polar substrates by using a primer/adhesive system have been used to n- crease the surface tension of polyolefinic materials.

United States Patent No. 2,911, 321 describes a method for bonding a poly- olefin layer on polyester using an"anchoring agent"of isocyanate/blocked isocyanate that is applied to the substrate as a dilute solution in organic solvent. The polyolefin is extruded onto the treated polyester substrate and bonded by heat and pressure.

United States Patent No. 4,345, 004 describes a method of forming an ole- finic coating on a (metal) substrate by applying a multi-layer film of epoxy resin, olefinic resin and modified olefinic resin, then heat bonding an olefinic resin layer thereto.

United States Patent No. 4,732, 632 describes a method of coating a sub- strate by applying a liquid, curable polymer composed of resin (e. g. epoxy; polyurethane precursor) and curative (e. g. isocyanurate) to the substrate, then applying a layer of polymer (e. g. polyolefin, EPDM, butyl, etc. ) that can interact chemically or physically with the curable first layer.

United States Patent No. 6,300, 418 discloses a thermoplastic elastomer composition compising a thermoplastic rubber containing a fully cured rub- ber and a thermoplastic polyolefin, a functionalized polyolefin and additives such as crosslinker and reinforcing fibers, e. g. carbon fibers.

United States Patent No. 6,072, 003 discloses a composition comprising a thermoplastic elastomer, a modified polyolefin and additives like fillers.

Saikrasun et al. in"Kevlar reinforcement of polyolefin-based thermoplastic elastomer", POLYMER, Elsevier Science Publishers B. V. , GB, Vol. 40, Nr. 23 Pages 6437-6442 discloses a fiber reinforced thermoplastic elastomer com-

prising a thermoplastic elastomer, a modified polyolefin and a surface modi- fied reinforcing aramid fiber.

International published patent application WO 03/062309 relates to a fiber reinforced rubber composition for tires comprising adhesive activated fi- bers in combination with melamine type crosslinking agents.

Nevertheless, reinforced elastomeric articles comprising the adhesion sys- tems known in the art show an undesired sensitivity to humidity. Since hu- midity is inevitably present in vehicle cooling systems, it has been a further object of the present invention to provide an adhesion system that is less sensitive to humidity/moisture and that is suitable for coolant hoses to be used in cooling water circuits of automotive engines.

A further aspect of the present invention relates to the method of manufac- turing shaped articles like cooling hoses.

By using a special die geometry, as disclosed, for instance by L. A. Goettler, A. J. Lambright, R. I. Leib and P. J. DiMauro at the meeting of the Rubber Division of the American Chemical Society on 7-10 October 1980 in De- troit, Michigan, the reinforcing short fibers (generally of less than 20 mm length) can be oriented toward the circumferential or hoop direction of the extruded hose, in order to counteract the high hoop stresses resulting from hydraulic pressure loading during use.

The economics of producing a reinforced hose structure in a single extrusion step through the use of a short fiber reinforced thermoplastic elastomer is further improved by this simplified shaping technique. Since down-line knit- ting and covering operations are eliminated through the use of short fiber reinforcement, the desired contour can be imposed on the hose right at the die. This is accomplished by simply moving the outer die out of the concen- tricity with the pin (inner die, or mandrel) or vice versa, so as to produce eccentricity in the annular die passage leading up to and including the ori- fice. Consequently, the resulting extrudate will bend away from the side of the die containing the wider passage.

By moving the inner or outer portions of the tube die out of the concentric- ity in a programmed sequence, the direction of extruding the hose can be made to deviate from the machine axis and thus to produce bends in the hose.

The mandrel die technology described above, in particular, facilitates the formation of tight bent hoses.

Nevertheless, it has been observed that burst strength is sacrificed in curv- ing the hose despite of substantial increases in stress in the inner wall of the bend due to the wall thinning and curvature effects.

Additionally, the shapes of the articles obtained are often limited by the sterical interaction of extrudate with the extruder and/or extrusion die. This can be conceived when the hose is widely curved in a direction opposite to the extrusion direction. In this case the shaped article is extruded in the direction of the extruder.

One way to overcome the curvature effects described above is the manufac- turing of hoses by blow molding. During the blow molding process the shape of a mold is transferred to the hose to be shaped. Therefore, this method necessitates molds having the individual shapes. Since the produc- tion of the molds is time and cost consumptive the production of hoses by said method, in particular in low quantities, is uneconomically.

It was therefore necessary to devise a method for the free shaping of cool- ant hoses that additionally avoids the curvature effects described above and which method does not necessitate expensive molds.

Summary of the Invention The present invention relates to a process for manufacturing a shaped arti- cle comprising processing a fiber-reinforced thermoplastic polymer in an extruder apparatus comprising an extruder barrel and an extrusion die wherein said extruder barrel discharging through a mandrel expansion ex- trusion die connected to a robotic handling unit, and wherein the extruder barrel is connected to the extrusion die by means of a flexible pressure hose.

The process according to the invention is applicable to any extrudable polymer composition in which fibers can be dispersed. Any polymer or polymer blend that may be extruded through dies by application of pressure is suitable in the practice of this invention. Thermoplastic polymers are par- ticularly suitable, examples of which are polyvinyl chloride, polyethylene, polypropylene, polyvinyl acetate, polyester polymers, for example, poly (ethylene terephthalate), ABS copolymers, polyamides, for example nylon. A preferred class of extrudable polymers is represented by elas- tomeric polymers. One class of suitable elastomeric (rubbery) polymer comprises thermoplastic elastomers which do not require vulcanization but are shaped above their softening temperature and develop elastomeric properties upon cooling.

Examples of satisfactory thermoplastic elastomers are polyurethane- polyester elastomers (commercially available under the Trademark Texin@), segmented polyethers and polyesters (commercially available under the Trademark Hytrel@), nylon block polymers, styrenic block thermoplastic elastomers and dynamically cured blends of polyolefin resin and mono- olefinic rubber. United States Patents Nos. 3,806, 558,3, 023,192, 3,651, 014,3, 763,109, 3,775, 373,3, 784,520 and 3,533, 172, the disclosure of which is fully incorporated herein by reference, illustrate suitable thermo- plastic elastomers.

Vulcanizable elastomers comprise another class of extrudable polymers, especially vulcanizable diene-containing elastomers. Either natural or syn- thetic rubbers or mixtures thereof are satisfactory. However, non-diene rubbers, like silicone rubbers or fluorinated rubbers are also satisfactory.

Illustrative examples of suitable synthetic rubbers include cis-4- polybutadiene, butyl rubber, neoprene, ethylene propylene terpolymers, polymers of 1,3-butadiene, polymers of isoprene, ethylene vinyl-acetate copolymers and copolymers of 1,3-butadiene with others monomers, for example, styrene, acrylonitrile, isobutylene and methylmethacrylate.

The reinforcing fibers to be used in conjunction with the thermoplastic polymers are further specified under paragraph"Reinforcing Fibers (D)"be- low.

In the reinforced thermoplastic polymers used in the process of this inven- tion the amount of reinforcing fibers (D) is from about 1 to about 30 wt.-%, preferably from about 5 to about 20 wt. -%, most preferably from about 8 to 16 wt. -%, based upon the total of the thermoplastic polymer and the rein- forcing fibers (D).

In a preferred embodiment the reinforcing fibers are finely dispersed within the thermoplastic polymer by methods known in the art, such as melt blending.

Thermoplastic Elastomer Composition The thermoplastic elastomer composition used as one alternative thermo- plastic polymer in the process according to the present invention comprises (A) a thermoplastic rubber comprising i. an at least partially cured rubber containing not more than 50 wt. -% of extractable rubber (23°C, 48h, cyclohexane) ; and ii. a thermoplastic polyolefin homopolymer or copoly- mer ; (B) a functionalized polyolefin ; (C) a crosslinking agent selected from resins obtainable by reacting mela- mine, urea, benzoguanamine and/or glycoluril with formaldehyde, ep- oxy-and isocyanate resins; and (D) reinforcing fibers adhesion activated by an epoxy resin selected from the group of glycerol-polyglycidylether, the reaction product of bisphe- nol A and epichlorohydrin and/or a blocked diisocyanate.

In a preferred embodiment the thermoplastic rubber is fully cured, i. e. , it contains not more than 5 wt. -% of extractable rubber (23°C, 48h, cyclohex- an e).

The crosslinked fiber reinforced thermoplastic elastomers obtainable from the compositions according to the invention have excellent mechanical

properties, high temperature and pressure resistance and a significantly decreased sensitivity to humidity.

Furthermore, the short fibers dispersed within the thermoplastic elastomer matrix lead to an improved structural integrity (green strength) that results in a minimum of shape distortion of the hot extrudate leaving the die orifice prior to its solidification. This structural integrity facilitates the processing of the thermoplastic compositions in the process of manufacturing shaped arti- cles, preferably free-standing shaped articles having improved dimensional stability, as described herein below.

The fiber-reinforced thermoplastic elastomer compositions are made by a process comprising the steps of (I) melt-blending of (i) a curable thermoplastic rubber, (ii) a thermoplastic polyolefin homopolymer or copoly- mer, and (iii) a curative, (II) dynamically vulcanizing the mixture to at least partially cure the curable thermoplastic rubber to obtain a thermoplastic rub- ber; (111) melt-blending of (A) the at least partially cured rubber containing not more than 50 wt. -% of extractable rubber (23°C, 48h, cyclo- hexane) of step (II) ; (B) a functionalized polyolefin ; (C) a crosslinking agent; and (D) adhesion activated fibers.

In a preferred embodiment the curable rubber is fully cured, i. e., it contains not more than 5 wt. -% of extractable rubber (23°C, 48h, cyclohexane).

The reinforced thermoplastic elastomer compositions having the properties mentioned above are preferably obtainable by said method after crosslink- ing.

According to the present invention it has surprisingly been found that an arrangement combining a mandrel die and a robotic handling unit as de- scribed in United States Patent No. 5,336, 349 the content of which is fully incorporated herein by reference, solves the problem of sterical interaction of the extrudate with the extrusion die and does not necessitate a mold.

The device according to the present invention facilitates the orientation of the extrusion die by the robotic handling unit.

The apparatus used in conjunction with the process of the present invention comprises (a) an extruder, (b) a mandrel expansion extrusion die, (c) a ro- botic handling unit, and (d) a flexible pressure hose, connecting the ex- truder (a) with the mandrel expansion extrusion die (b), wherein the man- drei expansion extrusion die (b) is controllably connected to the robotic handling unit (c).

In a preferred embodiment the mandrel expansion extrusion die (b) used in the process according to the present invention is an extrusion die having an inner or an outer die that can be offset to result in excentricity in the annu- lar die passage.

Thus, the apparatus used according to the invention facilitates the three- dimensional shaping of extrudates having wide and close bends without causing sterical interactions of the extrudate and parts of the extruder.

The process according to the present invention leads to shaped extruded articles of manufacture comprising the crosslinked reinforced thermoplastic elastomer composition described above. This article may be, for instance, a tube, or a hose, such as coolant hose having high resistance to humidity and excellent mechanical properties, such as pressure and temperature re- sistance.

The resulting extruded article may be of a complex shape, i. e. , having acute and wide bends, wherein the wide bends that are formed by the movement

of the robotic handling unit having a constant wall-thickness on the inside as well as on the outside of the curve.

Alternative and preferred embodiments of the present invention become apparent from the claims and the description that follows.

Description of the Drawings Fig. 1 is a perspective view of the apparatus according to this invention Fig. 2 represents a scheme of a hose having acute and wide bends extruded by the apparatus and method of this invention.

Detailed Description of the Invention In one embodiment of the thermoplastic polymers the reinforced thermo- plastic elastomer composition used in the process according to the present invention can be obtained by blending thermoplastic rubber, a functional- ized polyolefin (B), a crosslinking agent (C) and adhesion activated reinforc- ing fibers (D).

Preferably, the curable rubber (i), the thermoplastic polyolefin homopolymer or copolymer (ii) and the optional curative (iii) have been pre-blended and cured to form the fully cured thermoplastic elastomer (A) prior to its blend- ing with the functionalized polyolefin (B), the crosslinking agent (C) and the adhesion activated reinforcing fibers (D).

The components are mixed at a temperature sufficiently elevated to soften the resin or, preferably, at a temperature above its melting point at which the resin is crystalline at room temperature.

Mixing/blending of the individual compounds is performed using conven- tional mixing equipment such as roll mills, Banbury mixers, Brabender mix- ers, continuous mixers, mixing extruders, and the like. Conventional fillers and additives can be added to the composition at any stage of making it.

Preferably, the addition of the crosslinking agent (C) represents the final step of the process.

Thermoplastic Rubber (A) The thermoplastic rubber (elastomer) composition used according to the present invention as component (A) is generally obtained by blending a thermoplastic polyolefin with an elastomer (rubber) in a way that the elas- tomer is intimately and uniformly dispersed as a discrete particulate phase within a continuous phase of the thermoplastic. Early work with vulcanized compositions is found in U. S. Patent No. 3,037, 954 to Gessler which dis- closes static vulcanization as well as the technique of dynamic vulcanization wherein a vulcanizable elastomer is dispersed into a resinous thermoplastic polymer and the elastomer is cured while continuously mixing and shearing the polymer blend. The resulting composition (thermoplastic elastomer vul- canizate"TPV") is a microgel dispersion of cured elastomer, such as butyl rubber, chlorinated butyl rubber, polybutadiene, polyisobutene etc. in an uncured matrix of thermoplastic polymer, such as polypropylene.

Accordingly, the thermoplastic rubber component (A) may generally be pre- pared by mixing (i) an uncured rubber, (ii) a thermoplastic polyolefin ho- mopoJymer or copolymer and, optionally, (iii) conventional additives and fillers, then melting the mixture under kneading until a homogeneous blend is obtained. The addition of curing agents (also referred to as curatives, crosslinking-or vulcanizing agents) to the blend during the mixing under conditions of heat and shear results in a composition of an at least partially cured, preferably a fully cured (also referred to as"fully vulcanized"or"fully crosslinked") rubber dispersed in a thermoplastic matrix.

The term"rubber"as used herein means any natural or synthetic polymer that can be cured so as to exhibit elastomeric properties. For the purpose of this invention the term"elastomer"is used interchangeably with the term "rubber".

The term"fully cured"used in conjunction with the dynamically cured rub- ber component of this invention denotes that the rubber component to be vulcanized has been cured to a state in which the physical properties of the rubber are developed to impart elastomeric properties to the rubber gener- ally associated with the rubber in its conventional vulcanized state. The de- gree of cure of the vulcanized rubber can be described in terms of gel con-

tent or, conversely, extractable rubber components. Alternatively, the de- gree of cure can be expressed in terms of cross-link density. Where the de- termination of extractable rubber is an appropriate measure of the state of cure, the improved thermopiastic elastomeric compositions are produced by vulcanizing the curable rubber component of the blends to the extent that the composition contains, with increasing preference in the order given, no more than about 5,4, 3,2, 1 weight percent of the rubber component after curing being extractable at room temperature by a solvent that dissolves the uncured rubber. In one alternative the test specimen is extracted by cyclohexane at 23OC for 48 hours. In another alternative the test specimen is extracted in boiling xylene for one half hour. In general, the less ex- tractable rubber the cured rubber component contains the better the prop- erties of the TPE are. It follows that compositions comprising essentially no extractable rubber from the cured rubber phase are highly preferable. In terms of the present invention the term"no extractables"means less than about 0.5 percent by weight, ideally 0 percent by weight extractables. Gel content, reported as percent gel is determined by a procedure that com- prises determining the amount of insoluble polymer by soaking the speci- men for about 48 hours in an organic solvent (for instance, cyclohexane) at room temperature and weighing the dried residue and making suitable cor- rections based upon knowledge of the composition. Thus, corrected initial and final weights are obtained by subtracting from the initial weight, the weight of soluble components, other than the rubber to be vulcanized, such as extender oils, plasticizers and components of the compositions soluble in organic solvent, as well as that rubber component of the TPV which it is not intended to cure. Any insoluble pigments, fillers, etc. , are subtracted from both the initial and final weights. Supplementary to the above it is referred to United States Patent No. 4,311, 628, the disclosure of which is incorpo- rated herein by reference.

The term"partially cured"used in conjunction with the dynamically cured rubber component denotes that with increasing preference in the order given, up to about 50, up to 30, up to 15, up to but not including 5 weight percent of the cured rubber component being extractable at room tempera-

ture by a solvent that dissolves the uncured rubber (23°C, cyclohexane, 48h). As specified above fully cured rubbers are preferred.

In the measurement of the gel content asample of a thermoplastic elas- tomer composition of about 100 g is weighed and cut into fine fragments (size: 0.5 mm x 0.5 mm x 0.5 mm). In a closed vessel, the sample is im- mersed in 30 ml of cyclohexane at 23°C for 48 hours. Then, the sample is taken out, placed on a filter paper and dried at room temperature for not less than 72 hours until a constant weight is reached. From the weight of the dry residue, the weight of all the cyclohexane-insoluble components (e. g. , fibrous filler, filler, pigment) other than the polymer component is subtracted. The obtained value is taken as"corrected final weight (Y)". On the other hand, from the sample weight, the weight of the cyclohexane- soluble components (e. g. , softener) other than the polymer component and the weight of the cyclohexane-insoluble components (e. g., fibrous filler, filler, pigment) are subtracted. The obtained value is taken as"corrected initial weight (X)". The gel content (content of the cyclohexane-insoluble com ponents)is calculated by the following equation.

Gel-Content [wt.-%] = Y/X#100 In a preferred embodiment said thermoplastic rubber (A) has a Shore hard- ness from about 20A to about 60D, preferably from about 30A to about 40D, most preferably about 35A to about 85A (as measured according to ASTM D2240-02 @ 5 seconds delay).

In a further preferred embodiment the thermoplastic rubber (A) has an LCR-viscosity (laboratory capillary rheometer) of about 45 to about 70 Pa-s, preferably about 50 to about 65 Pa-s, and in a specific embodiment about 55 Pa-s.

For preparing the thermoplastic rubber composition used as the component (A) in the composition according to the present invention rubber (i) is mixed with the thermoplastic polyolefin homo-or copolymer (ii) at a temperature

sufficient to soften the resin or, more commonly, at a temperature above its melting point where the resin is crystalline at room temperature. After the polyolefin and rubber are intimately mixed, the curative is added. Heating and masticating with shearing at vulcanization temperatures are generally adequate to complete vulcanization in about 0.5 to about 10 minutes. The curing time can be reduced by elevating the curing temperature. A suitable range of curing temperatures is from about the peak melting point of the resin (for instance, about 130°C for high density polyethylene and about 165°C for polypropylene) to about 250°C. More typically, the temperature range is from about 160°C to about 225°C. Preferably the vulcanization is carried out at a temperature ranging from about 170into about 200 °C.

Dynamic vulcanization is effected by mixing the thermoplastic and elas- tomer components at elevated temperature on conventional mixing equip- ment such as roll mills, Banbury m ixers, Brabender mixers, continuous mix- ers, mixing extruders and the like.

Suitable thermoplastic rubbers (A) that can be used in conjunction with the present invention are commercially available, for instance from Advanced Elastomer Systems, Akron, OH, USA, under the trade designations Santo- prenez In accordance with the process according to the present invention thermo- plastic rubbers (A) utilizing phenolic curing systems are preferably used.

In the following the individual constituents of the thermoplastic rubber (A) are described in more detail.

Rubber (i) Illustrative, non-limiting examples of rubbers (i) suitable for use in the thermoplastic rubber (A) include rubbers selected from the group consisting of ethylene/alpha-olefin/non-conjugated diene copolymer rubbers, such as ethylene-propylene/non-conjugated diene rubber (EPDM), ethylene/alpha- olefin copolymer rubber wherein the alpha-olefin is of the formula C$=CHR and wherein R is a straight or branched alkyl group having 1 to 12 carbon atoms such as propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-

heptene, 1-octene, 3-methyl-1-pentene, 4methyl-1-pentene, 5-methyl-1- hexene, and the like. A preferred ethylene/alpha-olefin rubber is ethyl- ene/propylene copolymer rubber (EPM). Further examples of rubbers are butyl rubber, halogenated butyl rubber, copolymers of C4 to C7 isomonoole- fins and para-alkylstyrene and their halogenated derivatives, natural or syn- thetic rubbers, polyisoprene rubber, polybutadiene rubber, sty- rene/butadiene copolymer rubbers, and blends thereof.

The curable or vulcanizable rubbers that can be used in the practice of this invention include both synthetic and natural rubbers; at least one of the rubbers utilized must be vulcanizable.

While polyisobutylene (PIB) is not a true rubber because it cannot be vul- canized, it can be utilized in the practice of this invention in conjunction with a vulcanizable rubber provided that the PIB has a viscosity average molecular weight of from about 40,000 to about one million.

The term"nitrile rubber"means an acrylonitrile copolymer rubber. Suitable nitrile rubbers comprise rubbery polymers of 1,3-butadiene or isoprene and acrylonitrile. Preferred nitrile rubbers comprise polymers of 1,3-butadiene and about 20 to 50 weight percent acrylonitrile. Any nitrile rubber that is a "solid"rubber having an average molecular weight of at least 50,000, and preferably from about 100,000 to 1,000, 000 can be used. Commercially available nitrile rubbers suitable for the practice of the invention are de- scribed in Rubber World Blue Book, 1980 Edition, Materials and Compound- ing Ingredients for Rubber, pages 386-406.

Suitable halogenated copolymers of a t ; to CZ isomonoolefin and a para- alkylstyrene include copolymers comprising para-alkylstyrene moieties which may be represented by the formula:

wherein F and Ra are independently selected from the group consisting of hydrogen, alkyl groups having about 1 to 5 carbon atoms, primary and sec- ondary haloalkyl groups having about 1 to 5 carbon atoms, and X is se- lected from the group consisting of bromine, chlorine and mixtures thereof, such as those disclosed in published European Patent application 0355021.

Preferably, the alkylstyrene copolymer is a halogenated copolymer of isobu- tylene and para-methylstyrene, more preferably, the brominated copolymer of isobutylene and para-methylstyrene.

Butyl rubber is a copolymer of an isoolefin and a conjugated multiolefin. The useful rubber copolymers comprise a major portion of isoolefin and a minor amount, preferably not more than about 30 weight percent, of a conjugated multiolefin. The preferred rubber copolymers comprise about 85 to about 99.5 weight percent (preferably about 95 to 99.5 weight percent) of a C4 to C7 isoolefin, such as isobutylene, and about 15 to 0.5 weight percent (pref- erably about 5 to 0.5 wt %) of a multiolefin of about 4 to 14 carbon atoms.

These copolymers are referred to in the literature as"butyl rubber. " The term"butyl rubber"as used herein includes the aforementioned co- polymers of an isoolefin having 4 to 7 carbon atoms and about 0.5 to about 20 weight percent of a conjugated multiolefin of about 4 to 14 carbon at- oms. Preferably these copolymers contain about 0.5 to about 5% conju- gated multiolefin. The preferred isoolefin is isobutylene. Suitable conjugated multiolefins include isoprene, butadiene, dimethyl butadiene, piperylene, etc. Commercial butyl rubber is a copolymer of isobutylene and minor amounts of isoprene.

Butyl rubber as above described may be halogenated with from about 0.1 to about 10, preferably, about 0.5 to about 3.0 weight percent chlorine or bromine to make a suitable halobutyl rubber. The chlorinated form of butyl rubber is commonly known as"chlorobutyl rubber"and the brominated form as"bromobutyl rubber. " Another suitable rubber according to the present invention is based on poly- chlorinated butadienes such as polychloroprene rubber. These rubbers are commercially available under the trade names Neoprenes (DuPont Dow) and Bayprene (Mobay).

In a preferred embodiment of the invention the rubber (i) is an ethyl- ene/alpha-olefin copolymer rubber (EPM) or ethylene/alpha-olefin/non- conjugated diene copolymer rubber (EPDM), the latter being most pre- ferred.

The non-conjugated diene monomer can be a straight chain, branched chain or cyclic hydrocarbon diene having from about 6 to about 15 carbon atoms.

Examples of suitable non-conjugated dienes are straight chain acyclic die- nes such as 1,4-hexadiene and 1,6-octadiene : branched chain acyclic die- nes such as 5-methyl-1, 4-hexadiene ; 3, 7-dimethyl-1, 6-octadiene; 3,7- dim ethyl-1, 7-octadiene and mixed isomers of dihydromyricene and dihy- droocinene; single ring alicyclic dienes such as 1, 3-cyclopentadiene ; 1,4- cyclohexadiene ; 1, 5-cyclooctadiene and 1, 5-cyclododecadiene : and multi- ring alicyclic fused and bridged ring dienes such as tetrahydroindene, methyl tetrahydroindene, dicyclopentadiene ; bicyclo- (2, 2,1)-hepta-2, 5- diene ; alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as 5-methylene-2-norbornene (MNB); 5-propenyl-2-norbornene, 5- isopropylidene-2-norbornene ; 5- (4-cyclopentenyl)-2-norbornene, 5- cyclohexylidene-2-norbornene, 5-vinyl-2-norbornene and norbornadiene.

Of the dienes typically used to prepare EPDMs, the particularly preferred dienes are 1,4-hexadiene (HD), 5-ethylidene-2-norbornene (ENB), 5- vinylidene-2-norbornene (VNB), 5-methylene-2-norbornene (MNB), and di- cyclopentadiene (DCPD). The especially preferred dienes are 5-ethylidene- 2-norbornene (ENB) and 1,4-hexadiene (HD).

The ethylene/alpha-olefin/non-conjugated diene rubber contains from about 40 to about 85 weight percent of ethylene, preferably from about 45 to about 80 weight percent, and more preferably in the range of from about 50 to about 75 weight percent, based on the ethylene/propylene/non- conjugated diene rubber. The ethylene/propylene/non-conjugated diene rubber contains from about 0.25 to about 5 weight percent of diene, pref- erably from about 0.25 to about 2 weight percent and more preferably in the range of from about 0.5 to about 1.2 weight percent. The balance of the ethylene, alpha-olefin, non-conjugated diene elastomeric polymer to about 100 percent will generally be made up of an alpha-olefin which is selected from the group consisting of propylene, 1-butene, 1-hexene, 4-methyl-1- pentene, 1-octene, 1-decene and combinations thereof, and the like. The ethylenelpropylene/non-conjugated diene rubber which is preferred accord- ing to this invention contains propylene as the alpha-olefin and 5-vinyl-2- norbornene as the diene comonomer.

In the thermoplastic rubber component (A) the amount of rubber (i) gener- ally ranges from about 95 to about 10 weight percent, based on the weight of the rubber (i) and thermoplastic resin (ii) (total polymer). Preferably, the rubber content will be in the range of from about 80 to about 20 weight percent of total polymer.

Thermoplastic Polyolefin Homopolymer or Copolymer (ii) The term"thermoplastic polyolefin"as used herein in conjunction with the description of the thermoplastic elastomer component (A) denotes any polyolefin resin that exhibits thermoplastic properties.

A wide range of thermoplastic resins and/or their mixtures have been used in the preparation of thermoplastic elastomers, including polypropylene (PP), polypropylene copolymers, high density polyethylene (HDPE), low density polyethylene (LDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), polyethylene copolymers, cyclic olefin homopolymers or copolymers as well as olefinic block copolymers, polysty- rene, polyphenylene sulfide, polyphenylene oxide and ethylene propylene copolymer (EP) thermoplastics.

Thermoplastic resins useful in the compositions produced by the invention include crystalline and semi-crystalline polyolefin homopolymers and co- polymers. They are desirably prepared from mono-olefin monomers having about 2 to about 20, preferably about 2 to about 12, more preferably about 2 to about 7 carbon atoms, such as ethylene, propylene, 1-butene, isobu- tylene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 3-methyl-1-pentene, 4- methyl-1-pentene, 5-methyl-1-hexene and mixtures thereof and cops- mers thereof with (meth) acrylates, such as methyl (meth) acrylates.

As used in the specification and claims the term"polypropylene"includes homopolymers of propylene as well as reactor copolymers of polypropylene (PPRC) that can contain about 1 to about 20 weight percent of ethylene or an alpha-olefin comonomer of about 4 to about 20 carbon atoms, and mix- tures thereof. The polypropylene can be atactic, isotactic or syndiotactic, made with Ziegler-Natta or metallocene catalysts. The PPRC can be either a random or block copolymer. The density of the PP or PPRC can be from about 0.88 to about 0.92 g/cm3, preferably from about 0.89 to about 0.91 g/cm3. Commercially available polyolefins may be used in the practice of the invention. Blends of thermoplastic resins may also be used.

The preferred polyolefin resins are high density polyethylene (HDPE) and polypropylene. While other polyolefin homopolymers and copolymers of ethylene can be utilized in the practice of this invention, the resulting TPE compositions are deficient in high temperature characteristics. Such other polyolefins include low density polyethylene (LDPE), very bw density poly- ethylene (VLPE), linear low density polyethylene (LLDPE) and polybutylene (PB). However, these other polyolefin resins can be incorporated into the thermoplastic elastomer composition (a) of this invention along with the polypropylene (PP) or high density polyethylene (HDPE).

High density polyethylene (HDPE), useful as the polyolefin resin of this h- vention, has a density of about 0.941 to about 0.965 g/cm3. High density polyethylene is an established product of commerce and its manufacture and general properties are well known to the art. Typically, HDPE has a relatively broad molecular weight distribution, characterized by the ratio of

weight average molecular weight to number average molecular weight of from about 20 to about 40.

The term"low density polyethylene"or"LDPE"as used herein means both low and medium density polyethylene having densities of about 0.910 to about 0.940 g/cm3. The terms include linear polyethylene as well as- polymers of ethylene which are thermoplastic resins.

The term"very low density polyethylene"or"VLDPE"is used herein to mean polyethylene having a density below about 0.910 g/cm3 and includes linear polyethylene as well as copolymers of ethylene which are thermoplastic res- ins.

Linear low density polyethylene (LLDPE) is a class of low density polyethyl- ene characterized by little, if any, long chain branching derived from C3 to Ci2 alpha-olefins selected from the group consisting of propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene ; preferably 1-butene or 1-hexene.

The processes for producing LLDPE are well known in the art and commer- cial grades of this polyolefin resin are available. Generally, it is produced in gas-phase fluidized bed reactors or liquid-phase solution process reactors; the former process can be carried out at pressures of about 0.69 to 2. 07 MPa (100 to 300 psi) and temperatures as low as about 100 °C.

The amount of thermoplastic polyolefin (ii) found to provide useful composi- tions (A) is generally from about 5 to about 90 weight percent, based on the weight of the rubber (i) and thermoplastic polyolefin resin (ii). Prefera- bly, the thermoplastic resin content will range from about 20 to about 80 percent by weight of the total polymer.

Curatives (iii) In composition (A) the rubber component will be partially, preferably fully vulcanized/crosslinked. Those of ordinary skill in the art will appreciate the appropriate quantities, types of cure systems and vulcanization conditions required to carry out partial or full vulcanization of the rubber. The rubber can be vulcanized using varying amounts of curative, temperatures and time effective to obtain the optimum full crosslinking desired. Any known

cure system can be used, so long as it is suitable under the vulcanization conditions for the rubber being used and is compatible with the thermoplas- tic polyolefin resin component of the TPV. These curatives nclude sulfur, sulfur donors, metal oxides, resin systems, high energy radiation and the like, both with and without accelerators and co-agents. In a further pre- ferred alternative of the present invention crosslinking can also be effected by hydrosilylation crosslinking as disclosed in published European patent application 0776937, the disclosure of which is incorporated herein by ref- erence.

Organic peroxides with an adequate well-know co-agent can be used as cure system except where the butyl rubber is a non-halogenated butyl rub- ber. The role of the co-agent in peroxide cure systems is to enhance the cure-state and inhibiting chain-fragmentation or scission effect. Specific ex- amples of useful organic peroxides are selected from octanoyl peroxide, lauroyl peroxide, benzoyl peroxide, tert.-butyl peroctoate, p-chlorobenzoyl peroxide, 2, 4-dicholorbenzoyl peroxide, cyclohexanone peroxide, tert.-butyl peroxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, di-tert.- butyl peroxide, 2, 5-dim ethyl-2, 5-di (benzoylperoxy) hexane 2, 5-dimethyl- 2,5-di (tert.-butylperoxy) hexane, di-tert.-butyl diperoxiphthalate, tert. - butylcumyl peroxide, diisopropylbenzene hydroperoxide, 1,3-bis (tert.-butyl- peroxyisopropyl) benzene tert.-butyl peroxy-pivalate, 3,5, 5-trimethyl- hexanoyl peroxide, 1,1-bis (tert.-butyl-peroxy)-3, 5, 5-trimethylcyclohexane, 1,1-bis (tert.-butyl-peroxy) cyclohexane, etc.; azo compounds such as azo- bisisobutyronitrile, and the like.

The peroxide-based cure systems may be used with or without co-agents such as ethylene dimethacrylate, polyethylene glycol dimethacrylate, trimethylol propane trimethacrylate, divinyl benzene, diallyl itaconate, trial- lyl cyanurate, diallyl phthalate, allyl methacrylate, cyclohexyl methacrylate, m-phenylene bis maleimide (HVA-2), and the like.

Phenolic resin curatives are preferred for the preparation of the thermoplas- tic elastomer vulcanizate of the invention, and such cure systems are well known in the art and literature of vulcanization of rubbers. Their use in vul-

canized compositions is more fully described in U. S. Patent No. 4,311, 628, the disclosure of which is fully incorporated herein by this reference.

A basic ingredient of such system is a phenolic curing resin made by con- densation of halogen substituted phenol, C,-C10 alkyl substituted phenol or unsubstituted phenol with an aldehyde, preferably, formaldehyde, in an al- kaline medium or by condensation of bifunctional phenoldialcohols. Di- methylol phenols substituted in the para-position with C5-C10 alkyl groups are preferred. Halogenated alkyl substituted phenol curing resins prepared by halogenation of alkyl substituted phenol curing resin are also especially suitable. Phenolic curative systems comprising methylol phenolic resins, halogen donor and metal compound are especially recommended, details of which are described in Giller, U. S. Patent No. 3,287, 440 and Gerstin et al, U. S. Patent No. 3,709, 840. Non-halogenated phenol curing resins are used in conjunction with halogen donors, preferably, along with a hydrogen hal- ide scavenger. Ordinarily, halogenated, preferably brominated, phenolic res- ins containing about 2-10 weight percent bromine, do not require halogen donor but are used in conjunction with a hydrogen halide scavenger such as metal oxides such as iron oxide, titanium oxide, magnesium oxide, magne- sium silicate, silicon dioxide and preferably zinc oxide, the presence of which promotes the crosslinking function of the phenolic resin, however, with rubbers that do not readily cure with phenolic resins, the conjoint use of a halogen donor and zinc oxide is recommended. The preparation of halogenated phenol resins and their use in a curative system with zinc oxide are described in U. S. Patent Nos. 2,972, 600 and 3,093, 613, the disclosure of which along with the disclosure of the aforesaid Giller and Gerstin patents are incorporated herein by reference. Examples of suitable halogen donors are stannous chloride, ferric chloride, or halogen donating polymers such as chlorinated paraffin, chlorinated polyethylene, chlorosulfonated poly- ethylene, and polychlorobutadiene (neoprene rubber). The term"activator" as used herein means any material that materially increases the cross- linking efficiency of the phenolic curing resin and includes metal oxides and halogen donors either used alone or conjointly. For further details of pheno- lic curative systems see"Vulcanization and Vulcanizing Agents, "W. Hoff- man, Palmerton Publishing Company. Suitable phenolic curing resins and

brominated phenolic curing resins are commercially available, for example, such resins may be purchased under the trade names SP-1045, CRJ-352, SP-1055 and SP-1056 from Schenectady Chemicals, Inc. Similar function- ally equivalent phenolic curing resins may be obtained from other suppliers.

As explained above, sufficient quantities of curatives are used to achieve essentially complete cure of the rubber.

For halogenated butyl rubbers, a preferred cure system is one which is based on ZnO and/or MgO. In this system, the MgO does not act as an acti- vator but as an acid acceptor to stabilize the rubber from dehydrohalogena- tion.

Another preferred cure system for halogenated butyl rubbers comprises ZnO and a maleimide product. Among the maleimide product, a bismaleim- ide is especially superior in effectiveness and m-phenylene bismaleimide (4, 4'-m-phenylene bismaleimide) (HVA-2) preferred. Other examples of the bismaleimide are 4, 4'-vinylenediphenyl bismaleimide, p-phenylene bis- maleimide, 4, 4'-sulfonyidiphenyl bismaleimide, 2, 2'-dithiodiphenyl bis- maleimide, 4, 4'-ethylene-bis-oxophenyl bismaleimide, 3, 3'-dichloro-4, 4'- biphenyl bismaleimide, o-phenylene bismaleimide, hexamethylene bis- maleimide and 3,6-durine bismaleim ides. Usually about 1 to about 15 weight parts, preferably from about 2 to about 10 weight parts of the cura- tive or curative system are used per 100 weight parts of the rubber to be cured.

Conventional Additives and Fillers (iv) Depending upon the degree t which it might be desirable to have fillers and/or additives incorporated into the elastomer phase, the fillers and/or additives may be added at the desired level of cure of the elastomer phase.

As an alternative to the above process, the thermoplastic rubber (A) may be produced without fillers or additives. The fillers and/or additives may then be added in a later second compounding operation.

Generally, adding fillers and/or additives is conventional in the art of rubber compounding. Suitable additives are selected from the group consisting of pigments, antistatic agents, antioxidants, ultraviolet light stabilizers, anti-

blocking agents, lubricants, processing oils, waxes, coupling agents for fill- ers and mixtures thereof. The term"filler"as used herein refers to non- reinforcing fillers, reinforcing fillers, organic fillers and inorganic fillers. The fillers may be organic fillers and inorganic fillers (e. g. , mineral fillers). Pref- erably, the filler is an inorganic filler. Suitable fillers include talc, silica, clays, solid flame retardants, calcium carbonate, titanium dioxide, barium sulfate, carbon black, other mineral fillers, and mixtures thereof. The carbon black can be derived from any source and be any type of carbon black such as channel blacks, furnace blacks, thermal blacks, acetylene black, lamp black and the like. Any effective amount of filler may be added. Typically, the filler may be added in an amount of up to about 60 weight percent, preferably ranging from about 2 to about 50 weight percent based on the total thermoplastic dynamically vulcanized composition (A). For specific fill- ers, these proportions may vary. Carbon black, for instance, is preferably added in an amount ranging from about 1 to about 40 weight percent, more preferably from 2 to 20 weight percent, based on composition (A).

It will be understood that for a particular application, the effective amount of filler or additive may well be outside of these ranges. Since the invention concentrates the filler in the thermoplastic phase where it is most needed in the case of reinforcing fillers, a reduction in the quantity of filler to be added may be expected for maintaining the same strength desired.

The suitable additives for the practice of the invention may be added in an amount ranging from about 0.05 to about 5 weight percent, preferably from about 0.05 to about 3 weight percent, based on the total composition.

When the suitable additive is an ultraviolet light stabilizer, the ultraviolet light stabilizer may be present in an amount ranging from about 0.05 to about 1.0 weight percent, based on the total elastomeric composition (A).

The term"ultra-violet light stabilizer" (U. V. stabilizer, typically a particulate solid at standard temperature and pressure having a molecular weight of at least about 1,000, preferably, at least about 5,000) is used herein to denote compounds that provide stabilization or protection from the degrading ef- fects of ultra-violet light on TPV compositions. The U. V. stabilizers do not adversely affect the TPV compositions of the present invention. It has been

found that addition of U. V. stabilizers to TPV compositions can significantly decrease the crosslinking performance of curatives utilized for halobutyl elastomer materials. Such decrease does not occur to the same extent when the curative system is a maleimide curative system. Suitable U. V. stabilizers include hindered amine light stabilizers (HALS) which belong to a class of compounds referred to as"hindered amines."These hindered amines have been found to be effective in stabilizing polymers. See, for ex- ample, U. S. Patent No. 4,064, 102 the teachings of which are hereby incor- porated by reference. Preferred UV stabilizers are the 2,2, 4,4- tetramethylpiperidine derivatives such as N, N-bis (2,2, 6, 6-tetramethyl-4- piperidinyl)-1, 6-hexanediamine, bis (2, 2, 6, 6-tetra-methyl-4-piperidinyl) decane-dioate, and the reaction product of dimethyl succinate plus 4- hydroxy-2,2, 6, 6-tetramethyl-1-piperidine-ethanol sold by Ciba-Geigy Cor- poration under the trade names Chimassorbe 944LD, Tinuvin 770, and TinuvinO 622LD, respectively. The effective amount of U. V. stabilizer added will depend upon the particular stabilizer used and the degree of protection desired. The HALS is employed at about 0.01 to 0.5 wt % of the composi- tion (A), preferably from about 0. 02 to 0.25 wt %, and most preferably from about 0.03 to 0.15 wt %, based on composition (A).

When U. V. stabilizers are used it is preferred that the blends be dynamically vulcanized in the presence of a maleimide cure system although other cure systems discussed below are also useful. The maleimide compound prefera- bly used in the invention is a bismaleimide compound. Among the maleim- ide compounds a bismaleimide compound is especially superior in effective- ness and m-phenylene bismaleimide (4, 4'-m-phenylene bismaleimide) is preferred. Examples of the bismaleimide are 4, 4'-vinylenediphenyl bis- maleimide, p-phenylene bismaleimide, 4, 4'-sulfonyidiphenyl bismaleimide, 2, 2'-dithiodiphenyl bismaleimide, 4, 4'-ethylene-bis-oxophenyl bismaleim- ide, 3, 3'-dichloro-4, 4'-biphenyl bismaleimide, o-phenylene bismaleimide, m-phenylene bismaleimide (HVA-2), hexamethylene bismaleimide and 3,6- purine bismaleimides.

Rubber process oils have particular ASTM designations depending on whether they fall into the class of paraffinic, naphthenic or aromatic process

oils. They are derived from petroleum fractions. The type of process oil util- ized will be that customarily used in conjunction with the rubber compo- nent. The ordinarily skilled rubber chemist will recognize which type of oil that should be utilized with a particular rubber. The quantity of rubber proc- ess oil utilized is based on the total rubber content, both cured and un- cured, and can be defined as the ratio, by weight, of process oil to the total rubber in the TPE. This ratio may range from about above 0 to about 1.5/1, preferably about 0.2/1 to about 1.0/1 ; more preferably about 0.3/1 to about 0.8/1. Larger amounts of process oil can be used, the deficit being reduced physical strength of the composition. Oils other than petroleum based oils, such as oils derived from coal tar and pine tar, can also be util- ized. In addition to the rubber process oils, organic esters and other syn- thetic plasticizers may be used.

Antioxidants can be added to the rubber composition (A). The particular an- tioxidant utilized will depend on the rubbers utilized as can synthetic oils such as isoparaffinic oil and more than one type may be required. Their proper selection is well within the ordinary skill of the rubber processing chemist. Antioxidants will generally fall into the class of chemical protectors or physical protectants.

Physical protectants are used where there is to be little movement in the part to be manufactured from the composition. These are generally waxy materials that impart a"bloom"to the surface of the rubber part and form a protective coating to shield the part from oxygen, ozone, etc.

The chemical protectors generally fall into three chemical groups; secondary amines, phenolics and phosphites. Typical examples of these types of anti- oxidants useful in the practice of this invention are conventional and known to the skilled person and are selected from the groups of compounds such as hindered phenols, amino phenols, hydroquinones, alkyldiamines, amine condensation products, etc. Examples for the antioxidants include phenol- based antioxidants, amine-based antioxidants, sulfur-based oxidants, and the like, The physical antioxidants include mixed petroleum waxes and micro- crystalline waxes. All or a portion of the fillers and/or additives can be

added before the dynamic vulcanization step, after partial but before the dynamic vulcanization step or after the dynamic vulcanization step.

In the reinforced thermoplastic elastomer composition of this invention the thermoplastic rubber (A) may be present from about 40 wt. -% to about 95 wt.-%, preferably from about 60 wt. -% to about 85 wt. -%, most pref- erably from about 70 wt. -% to about 80 wt. -%, based upon the total of the thermoplastic rubber (A), the functionalized polyolefin (B), the crosslinking agent (C) and the adhesion activated reinforcing fibers (D).

Functionalized Polyolefin (B) In accordance with the present invention the functionalized polyolefin (B) is selected from homopolymers or copolymers of Cz to C7 monoolefin mono- mers or copolymers of C2 to C, monoolefinmonomers with acrylates, (meth) acrylates, such as methyl-, ethyl-, propyl-, or butyl-methacrylates or vinyl acetates. The Ce to C, monoolefin monomers can be selected from ethylene, propylene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1- heptene, 1-octene, 3-methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1- hexene and mixtures thereof. In a preferred embodiment of the present invention the functionalized polyolefins have grafted thereon monomers se- lected from unsaturated carboxylic acids containing 3 to 20 carbon at- oms, unsaturated dicarboxylic acids containing 4 to 10 carbon at- oms or their derivatives or their anhydrides provided that they exist, epoxy-group containing esters of unsaturated carboxylic ac- ids containing at least 6 carbon atoms, hydroxy-group containing esters of unsaturated carboxylic acids containing at least 5 carbon atoms, oxazoline

said unsaturated carboxylic acid and/or unsaturated dicarboxylic acid mono- mers being further functionalized with polyamines, and mixtures thereof.

Suitable functionalized polyolefins are disclosed in United States Patent 5,609, 962, the disclosure of which is fully incorporated herein by reference.

Examples of the unsaturated carboxylic acids, dicarboxylic acids that may be present in the functionalized polyolefin are those having 3 to 20 carbon atoms per molecule such as acrylic acid, methacrylic acid, maleic acid, fu- maric acid and itaconic acid.

Especially preferred as grafting monomers are selected from unsaturated dicarboxylic acids having 4 to 10 carbon atoms per molecule and anhydrides thereof. These grafting monomers include, for example, maleic acid, t- maric acid, itaconic acid, citraconic acid, cyclohex-4-ene-1, 2-di-carboxylic acid, bicyclo [2. 2.1] hept-5-ene-2, 3-dicarboxylic acid, maleic anhydride, ita- conic anhydride, citraconic anhydride, allylsuccinic anhydride, 4- methylcyclohex-4-ene-1, 2-dicarboxylic anhydride and bicyclo [2.2. 1] hept-5- ene-2, 3-dicarboxylic anhydride. In a preferred embodiment maleic acid grafted polypropylene (MA-g-PP) supplied by Uniroyal Chemical Co. under the trade designation POLYBOND° 3150 has been used.

Further grafting monomers are epoxy-group containing esters of unsatu- rated carboxylic acids that contain at least 6, preferably 7 carbon atoms and up to 20 carbon atoms.

Particularly preferred are glycidyl acrylate and glycidyl methacrylate. Fur- ther grafting monomers are hydroxy-group containing compounds such as hydroxy-group containing esters of unsaturated carboxylic acids containing at least 5 carbon atoms, preferably up to 6 carbon atoms and up to 12 car- bon atoms such as 2-hydroxyethylmethacrylate, 2-hydroxyethylacrylate, hydroxypropylmethacrylate and hydroxypropylacrylate.

Further preferred are polyolefins which comprise amine functional groups.

These are obtainable by reaction of polyolefins containing carboxylic acids, anhydrides or epoxy groups as described above with polyamines (diamines, triamines, tetramines) and derivatives thereof such as 3-amino-1-

methylaminopropane, piperazine, polyoxyalkyleneamines family (Jeffam- ine@).

Furthermore, the polyolefins can be functionalized with an oxazoline group by using, for example, 2-(4-vinylphenyl)-4, 4-dimethyl-2-oxazoline as the grafting monomer.

Various known methods can be used to graft the grafting monomer onto the basic polymer. For example, this can be achieved by heating the polymer and the grafting monomer at high temperatures of from about 150°C b about 300°C in the presence or absence of a solvent with or without radical initiator. Another vinyl monomer may be present during the grafting reac- tion. Suitable radical initiators that may be used include tert.-butyl hydrop- eroxide, diisopropylbenzene hydroperoxide, di-tert.-butyl peroxide, tert.- butyl cumyl peroxide, acetyl peroxide, benzoyl peroxide, isobutyryl peroxide and methylethylketone peroxide.

In the functionalized polyolefin thus obtained, the amount of graft mono- mer, preferably the amount of the carboxylic acid or anhydride is about 0.3 to about 10 wt-%, more preferably about 0.3 to about 5 wt. -%, and most preferably at least about 1 wt. -%, based on the weight of the functionalized polyolefin (B).

In a preferred embodiment maleated polypropylene which is supplied, e. g., by DuPont under the trade designation Fusabonde is used as the functional polyolefin (B).

In a further preferred embodiment the content of the graft monomers in the functionalized polyolefin (B) is from about 0.1 wt. -% to 10 wt. -%, prefera- bly about 0.3 wt.-% to 5 wt. -%, most preferably about 0.5 wt. -% to 3.0 wt. -%, based on the amount of the functionalized polyolefin (B).

In the reinforced thermoplastic elastomer composition the functionalized polyolefin (B) is from about 0.3 wt. -% to about 15 wt. -%, preferably from about 1 wt. -% to about 10 wt.-%, most preferably from about 3wt.-% to about 8wt. -%, based upon the total of the thermoplastic rubber (A), the functionalized polyolefin (B), the crosslinking agent (C) and the adhesion activated reinforcing fibers (D).

Crosslinking Agent (C) It has surprisingly been found that the adhesion of adhesion activated fibers (D) to the thermoplastic composition (A) can significantly be improved, in particular with regard to the moisture sensitivity and bonding strength of the obtained fiber reinforced thermoplastic elastomer, if a crosslinking agent (C) is added to the composition. The crosslinking agents that are used in accordance with the present invention initiate crosslinking of the functional- ized polyolefin (B) with the adhesion activation system of the reinforcing fibers (D).

Preferred crosslinking agents (C) are compounds obtainable by the reaction of melamines, urea, benzoguanamine, glycoluril or mixtures thereof with formaldehyde. Moreover, epoxy and/or isocyanate resins can be used as crosslinking agents (C) according to the present invention. In a more pre- ferred embodiment melamine resins are used as crosslinking agents (C).

Preferred melamine resins are selected from the group consisting of hexa- methoxymethylmelamine resins, high solids methylated melamine resins, high solids mixed ether melamine resins and butylated melamine resins.

"High solids"means that the solid content is generally above 70 to 98 wt.- %, based on organic volatile measurements. Said crosslinking agents are commercially available, for instance, from SOLUTIA under the trade desig- nation Resimenes or from CYTEC under the trade designation Cyme@. In a preferred exemplary embodiment Resimene"745 (hexamethoxymethyl- melamine) and Resimene@3521 S are used.

In an alternative embodiment of the invention epoxy resins are used as crosslinking agents (C). Epoxy resins are prepolymers obtainable by the re- action of epichlorohydrine with a diol, triol or polyol, such as bisphenol A.

The epoxy resins contain on the average two or more epoxide groups per molecule. Their reaction with a variety of curing agents leads to cross-linked or thermoset plastics with excellent strength, toughness and chemical resis- tance. Suitable epoxy resins are known from the prior art a commercially available. For instance, D. E. R. @, D. E. N. @, Tactix@, Quartexs supplied by Dow Chemical ; Pore, Epikoteo, Eponof, Eponexs supplied by Shell ; Araldite@, Aracasf supplied by Ciba Geigy; Epi-Rz° supplied by Celanese, Epotufo)

supplied by Reichold or Uno) e supplied by Union Carbide, Neukadur@, Bire- sine and Ebalta LM can be used.

In a further alternative embodiment isocyanate resins can be used as crosslinking agents (C). Suitable isocyanates are diisocyanates having two reactive isocyanate groups suitable to react with both the functionalized polyolefin (B) and with the adhesion activation system of the reinforcing fibers (D) in order to crosslink. Representative diisocyanates are typically selected from diisocyanates such as 1, 6-hexamethylene diisocyanate, 1,8- octomethylene diisocyanate, 1, 12-dodecamethylene diisocyanate, 2,2, 4- trimethylhexamethylene diisocyanate and similar isocyanates, 3,3'- diisocyanatodipropyl ether, 3-isocyanatomethyl-3, 5, 5'-trimethylcyclohexyl isocyanate, cyclopentalene-1, 3-diisocyanate, cyclohexylene-1, 4- diisocyanate, methyl-2, 6-diisocyanatocaprolate, bis- (2-isocyanatoethyl)- fumarate, 4-methyl-1, 3-diisocyanatocyclohexane, trans-vinylene diisocy- anate and similar unsaturated polyisocyanates, 4, 4'-methylene-bis- (cyclohexylisocyanate) and related polyisocyanates, methane diisocyanates, bis- (2-isocyanatoethyl) carbonate and similar carbonate polyisocyanates, N, N'N"-tris-(6-isocyanatohexamethylene) biuret and related polyisocyanates as well as other known polyisocyanates derived from aliphatic polyamines, toluene diisocyanates, xylene diisocyanates, dianisidine diisocyanate, 4,4'- diphenylm ethane diisocyanate, 1-ethoxy-2,4-diisocyanatobenzene, 1- chloro-2, 4-diisocyanatobenzene, tris (4-isocyanatophenyl) methane, naph- thalene diisocyanates, 4, 4'-biphenyl diisocyanate, phenylen diisocyanates, 3, 3'-dimethyl-4, 4'-biphenyl diisocyanate, p-isocyanatobenzoyl isocyanate and tetrachloro-1, 3-phenylene diisocyanate, and mixtures thereof. In a pre- ferred embodiment of the invention isocyanates blocked by caprolactam, phenol and other blocking-agents known in the prior art are used. In a fur- ther preferred embodiment polyisocyanates based on isophorone diisocy- anate and other known blocked poly-isocyanates and blends thereof are used. A caprolactam blocked isocyanate that is preferably used in conjunc- tion with the present invention is commercially available from EMS-Chemie under the name Grilbonds IL-6.

In a preferred embodiment of the method for making the reinforced ther- moplastic elastomer composition the crosslinking agent (C) is the last com- ponent added to the composition comprising the thermoplastic rubber (A), the functionalized polyolefin (B) and the adhesion activated reinforcing fi- bers (D), i. e. , component (C) is added after thoroughly melt-blending the further components. Preferably, the crosslinking agent is added in the ex- trusion step, i. e. , when the entire blend is at a temperature of from 150 °C to 250 °C, preferably from 180 °C to 230 °C.

In an alternative embodiment the crosslinking agent (C) is applied to the adhesion activated fibers (D) prior to embedding them into the thermoplas- tic rubber (A) and the functionalized polyolefin (B). Crosslinking proceeds at temperatures between about 150 and 250 °C, i. e., typically under extru- sion and molding conditions mentioned above.

The reinforced thermoplastic elastomer composition contains the crosslink- ing agent (C) in an amount from about 0.3 wt. -% to about 15 wt.-%, pref- erably from about 1 wt. -% to about 10 wt. -%, most preferably from about 3 wt. -% to about 7 wt. -%, based upon the total of the thermoplastic rubber (A), the functionalized polyolefin (B), crosslinking agent (C) and the adhe- sion activated reinforcing fibers (D).

Reinforcing Fibers (D) The present invention is not limited to any special kind of fibers. Accord- ingly, any kind of organic, inorganic, synthetic or non-synthetic fibers can be used as the reinforcing fiber, for instance, fibers selected from the group consisting of polyester, polyaramid, polyethylene naphthalate (PEN), poly- <BR> <BR> <BR> <BR> ester-polyarylate, polyvinylchloride, polypropylene, polyphenylenesulfide, polyetherimid, polyamide, polyimide or cellulose fibers are used. As an al- ternative inorganic fibers such as glass, steel, boron, carbon or wollastonite fibers, clay, talkum or fibrous hydrated magnesium silicate of the formula Mg4Si6016 (OH) 2-6can be used.

In a preferred embodiment polyaramid fibers or polyester-polyarylate fibers are used. Both kinds of fibers having high mechanical stability which facili-

tates the recycling of the reinforced thermoplastic elastomer compositions without decreasing their fiber-length. Suitable'polyaramid fibers are com- mercially available from Teijin Twaron B. V. under the trade designation Twaron°, polyester-polyarylate fibers are available under the trade designa- tion Vectrane from Celanese. According to the present invention the rein- forcing fibers (D) preferably have a fiber length of about 0.3 mm to 20 mm, preferably about 1 mm to 15 mm or 6 mm, most preferably about 2 mm to 4 mm.

In a preferred embodiment the diameter of said fibers (D) ranges from about 1 to about 100 um, preferably from about 5 to about 75 um, most preferably from about 10 to about 30 . m.

In the preferably used reinforced thermoplastic elastomer composition the amount of adhesion activated reinforcing fibers (D) is from about 1 to about 30 wt.-%, preferably from about 5 to about 20 wt.-%, most preferably from about 8 to 16 wt.-%, based upon the total of the thermoplastic rubber (A), the functionalized polyolefin (B), the crosslinking agent (C) and the adhe- sion activated reinforcing fibers (D).

Typically, most of the reinforcing fibers mentioned above require a surface treatment in order to achieve good adhesion to the surrounding elastomeric matrix.

In the present invention any adhesion activating system that is suitable to react with the crosslinking agent (C) may be used.

For instance, Twarons fibers which inter alia may be used in the present invention comprise a cured epoxy-containing finish as disclosed in published European patent application 0107887, the disclosure of which is fully incor- porated herein by reference.

In accordance with the present invention the reinforcing fibers are adhesion activated in order to improve the adhesion between the fiber surface and the embedding thermoplastic elastomer composition matrix. Therefore, the fibers are surface treated prior to embedding them into the elastomer com- position matrix. The surface treatment promotes adhesion by the formation

of a thin layer of the adhesion activating agent (adhesion promoter) on the fiber surface.

In a preferred embodiment of the present invention polyester, polyester- polyarylate-or polyaramid fibers have been treated by the method as de- scribed in United States Patent 5,609, 962 from col. 2, line 10 to col. 8 line 47, the disclosure of which is fully incorporated herein by reference.

According to that method the fibers may optionally be epoxy-activated which means that the polyester is treated with an epoxy derivative such as 1-chloro-2, 3-epoxypropane (epichlorohydrine).

In a first step the fibers can be treated with a water-dispersible, blocked di- isocyanate in aqueous dispersion. The blocked di-isocyanates are selected from caprolactam blocked methylene-bis- (4-phenylisocyanate) or 4,4'- methylene-bis- (phenylcarbanilate).

The treatment may be carried out by dipping the fibers into the dispersion containing the blocked diisocyanate. The dipping time commonly depends on the nature fibers and can vary from 1 second to 1 hour. After dipping the fibers are dried at a suitable temperature to effect the evaporation of water.

Drying can be accomplished by exposing the fibers to a temperature of from 100°Cto 240°Cfor 1 to 60 minutes, depending on the nature of the fibers.

In a second step the treated and dried fibers are then treated with a water- based epoxy resin emulsion in an aqueous emulsion. The epoxy resins are selected from glycerol-poly-glycidylether (e. g. Glycidether 100, supplied by Raschig, Germany), epoxy resin resulting from the reaction between bisphenol A and epichlorohydrin and modified in order to make it water emulsifiable, such as Epikote DX 258, a product of Shell Chemical or Eure- pox 756/67W supplied by Witco. As to the treatment, to the conditions of the treatment and the subsequent drying step it is referred to what has been set out above with respect to the treatment of the fibers with the dis- persion of the blocked diisocyanate. Instead of dipping the fibers into the emulsions/dispersions the emulsions/dispersions can also be sprayed onto the surface of the fibers and subsequently dried.

It should be noted that the first and the second step for the treatment of the fibers can be reversed, i. e. the treatment of the fibers with the epoxy resin can be carried out prior to the treatment of the fibers with the blocked di-isocyanate. The treatment of the fibers with the blocked diisocyanate and the epoxy resin can also be carried out in one step, i. e. simultaneously. In this instance only one drying step is required.

The treatment of the fibers can also be carried out using the dispersion of the blocked di-isocyanate alone and applying it as described above. The fi- nal amount of the treatment agent (blocked di-isocyanate and epoxy-resin or blocked di-isocyanate alone) on the treated fibers is about 5 to about 500 grams per one m2 of fiber surface, preferably about 20 to about 100 g/m2.

The dried fibers are then further processed by bonding thereon the modified thermoplastic elastomer under the influence of heat and pressure as de- scribed herein below.

In conjunction with the present invention a caprolactame-blocked diisocy- anate supplied by EMS-Chemie, Switzerland, under the trade designation Grillbond° has preferably been used.

Generally, any adhesion activation system known in the art for improving and/or imparting adhesion of filaments, such as polyester, polyaramid and polyamide fibers/filaments to rubbers when forming fiber-reinforced rubber composites can be utilized such as those disclosed in United States Patent Nos. 3,956, 566; 3,964, 950; 3,968, 304; 3,991, 027; 4,009, 134; 4,026, 744; 4,134, 869; 4,251, 409 and 4,409, 055, the entire disclosures of which are incorporated herein by reference.

In general the thermoplastic elastomer blend is applied to the fibers under exposure to heat and pressure, for instance by use of conventional mixing equipment such as roll mills, Banbury mixers, Brabender mixers, continuous mixers, mixing extruders, and the like.

Articles made from the cured reinforced elastomer compositions according to the present nvention have good mechanical properties in combination with a high chemical, heat and pressure stability and a significantly less sensitive to humidity.

Consequently, the reinforced elastomer compositions according to the pre- sent invention can advantageously applied in processes for the manufactur- ing of extruded shaped articles requiring a high stability to heat and pres- sure and resistance to chemicals, such as in automotive applications, for instance, coolant hoses as well as tubes. Typical processes are extrusion and molding processes, such as conventional extrusion or blow molding.

Manufacturing of Shaped Articles The reinforced elastomeric compositions according to the present invention exhibit sufficient green strength, i. e. , a structural integrity necessary to minimize the shape distortion prior to solidifying of the extrudate after leav- ing the extrusion die orifice.

The reinforced elastomer compositions according to the present invention can be shaped by extrusion using conventional moving mandrel expanding dies. The fiber reinforced thermoplastic elastomer composition of the pre- sent invention leads to shaped articles that are less sensitive to humidity.

In order to overcome the disadvantages of sterical interaction of extruder and extrudate and the different wall thicknesses of the extrudate it has been found that an extrusion die arranged at a robotic handling unit leads to an apparatus for free-shaping of an extrudate.

The arrangement is comparable to a robotic extrusion assembly as de- scribed in United States Patent No. 5,336, 349 to Cornils et al., the disclo- sure of which is fully incorporated herein by reference.

The thermoplastic elastomer composition according to this invention is fed via an extruder 1 and a heated pressure hose 2 to a heated extrusion die 3.

The extrusion die is guided by a robot 4, and the elastomer is extruded and laid by means of the extrusion die onto a preferably pre-shaped supplemen- tary surface 5. The die is guided by an automatic handling device and the elastomer is extruded and simultaneously shaped. In a preferred embodi- ment the extrusion die 3 is a moving mandrel expanding die as disclosed in L. A. Goettler, A. J. Lambright, R. I. Leib and P. J. DiMauro at the meeting of the Rubber Division of the American Chemical Society on 7 to 10 October

1980 in Detroit, Michigan. With this assembly acute bends are formed by offsetting the inner and outer part of the mandrel expansion extrusion die 3 and wider bends are formed by the movement of the robotic handling unit 4.

Moreover, the movement of the robotic handling unit 4 may be aligned with the off-setting of the inner die 3 in order to obtain extrudates 6 having con- stant wall thicknesses on the inside and on the outside of the bends.

For instance, the excessive movement of the robotic handling unit 4 would generally result in a bend that is stretched on the outside (wide radius) and compressed on the inside (narrow radius). Consequently, the wall thickness of the wall inside the bend would be thicker compared to the thinner wall outside the bend. Off-setting of the inner or outer part of the die counter- acts the formation of different wall thicknesses if the annular die passage is narrow on the inside and wide on the outside of the bend.

In order to prevent the extrudate 6 from coming in contact with the ex- truder 1, the extrusion die 3 or the handling unit 4, the outlet orifice of the mandrel die 3 that is arranged at the handling unit 4 is oriented into a di- rection away from the extruder/handling unit 1/4.

In the method according to this invention common screw extruders com- prising external cylinder heaters may be used, that plasticize the thermo- plastic elastomeric material to the necessary processing temperature. The molten elastomer is supplied from the discharging zone of the extruder to the extrusion die via a flexible high pressure hose, also provided with a suitable heater, which hose must be capable of resisting the high pressures corresponding to the viscosity of the thermoplastic elastomer. The mandrel extrusion die is also heated by means of a suitable heater to the necessary processing temperature of the elastomer and is guided by means of a robot.

Depending on the needs the pressure hose may have a length of from about 20 cm to about 6.0 m, and a diameter of from about 5 mm to 50 mm.

For further particulars about robotic extrusion reference is made to United States Patent No. 5,336, 349 to Cornils et al., the disclosure of which is n- corporated herein by reference in its entirety.

To produce a shaped extrudate the dry blend is typically processed in a long-barrel extruder having a barrel length/diameter (L/D) ratio in the range from about 24: 1 to about 60: 1, fitted with a screw that provides a compression ratio greater than about 2.5 : 1, and a substantially constant pressure on the melt within the barrel, and preferably in the entry zone of a grooved barrel section. In one embodiment the diameter of said barrel is in the range from about 2.54 cm to about 15.24 cm. The extrudate may also be produced in a tandem or twin screw extruder.

For the extrusion process according to the present invention any extrusion die can be used. Preferred is an extrusion die that facilitates the control of the fiber orientation within the extrudate. Most preferred is a mandrel ex- panding extrusion die comprising an inner and an outer die that can be off- set in order to shape the extrudate. The obtained parisons (extrudates) of present invention having a high melt strength based on the morphology of the thermoplastic elastomer used and also due to the presence and orienta- tion of the short fibers which is sufficient for a parison manipulation by modern blow-molding techniques. Typical extrusion temperatures are from about 150 °C to about 250 °C, preferably from about 180 °Cto about 230 °C.

The following examples are presented to illustrate the invention which is not intended to be considered as being limited thereto. In the examples and throughout percentages are by weight unless otherwise indicated.

While in accordance with the patent statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.

Examples Effect of Fiber Reinforcement on Burst Pressure of a Hose The hoses have been manufactured by melt-extrusion of a composition comprising Santoprenee 121-67W175, Orevace (carboxylated polypropyl- ene) and the respective amounts of aramid fibers via a mandrel expanding die @ 200°C. Aramid fiber content [%] 0 5 10 Burst pressure @120°C [bar] 1. 2 2. 8 3. 5

Effect of Different Shaping Methods on Fiber Reinforced Hoses Shaping by Movement of the Robotic Handling Unit Hoop Properties Axial Properties Wall thickness [mm] 2.2 2.6 2.3 2. 5 Tensile strength [MPa] 4.5 4.7 5.1 5. 0 Elongation at break [%] 249 273 317 305 Modulus at 50% ext [MPa] 2.6 2.6 2.7 2.7

Note: All measurements of the elastomeric properties have been performed according to ISO 37/1994.

Shaping by Off-setting the Die Hoop Properties Axial Properties Wall thickness [mm] 2.7 2. 1 2.6 2.3 Tensile strength [MPa] 4.3 4.3 5.0 5.1 Elongation at break [%] 212 240 267 308 Modulus at 50% ext. 2. 5 2.7 2.8 2.7

The hoses have been manufactured by melt-extrusion of a composition comprising Santoprene"101-64 and 5 wt. -% of aramid short fibers via a mandrel expanding die @ 200°C. The degree of cure has been determined to be above 96 % as determined by the extraction method described above.

Flexible Extrusion of a TPE Hose Materials used: Santoprenee SFR001, based on Santoprene 101-64, maleated polypropylene and 8 wt. -% of adhesive activated polyester short fibers.

Extrusion Equipment: Single screw extruder of 45 mm diameter and 25 : 1 L/D; Reis RV30 robot, mandrel expansion extrusion die with 21.2 mm outer diameter, 15.2 mm inner diameter and a 2.5 : 1 expansion ratio. Off-setting of the die was con- trolled by two DC motors.

Test Procedure : Extrusion of a hose with a straight end and three curves (see Figure 2), wherein the geometry of a curve is predominantly realized by the robot movement and to a smaller extend by the off-setting of the inner die in or- der to compensate for any difference in wall thickness of the tube. Extrusion speed with regard to max. pressure limit : 16 mm/s C 19. 1 MPa, dosing rate of extruder: 40%.

To check the reproducibility a total of ten hoses were extruded and cut into cross sections for measuring the wall thickness. The average values are given in the Table below.

Test Results: A reproducible extrusion of hoses could be verified. The deviation of the wall thickness in the area of the curves is acceptable as it can be derived from the list which follows. Curve 1 Curve 2 Curve 3 inner outer inner inner outer A inner outer A wall wall wall wall wall wall [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] 2,69 2,72 0,03 2,71 2,72 0,01 2,72 2,72 0,00