FR2662611A1 - SKI AND SKI ELEMENTS. - Google Patents

Abstract

The invention relates to a ski for use on snow, produced by the assembly of several components, at least one of which consists partially or totally of a composition comprising at least one polyamide-based thermoplastic elastomer and at least one modified polyolefin. These components are, in particular, added moulded parts of shock-absorbing components, or adhesive-bonding films, for example.

Description

i The present invention relates to skis intended to be used on

  snow and in particular the elements used in the constitution of skis These elements have the particularity of being a composition of elastomer (s)

  thermoplastic (s) (TPE) based on polyamide and modified polyolefin (s).

  In patent application FR 2 523 143, compositions containing ethylene-based copolymers (at least 35% by weight) and at least one vinyl ester and containing from 0.5 to 20% of are described. a

  copolyetheresteramide which can be used as hot-melt adhesives (hot-

  melts). 1 O In patent application J 62-84141, resin compositions have been described prepared by mixing in the molten state of 100 parts by weight of polyetheresteramide and from 3 to 50 parts by weight of an ethylene copolymer and

  vinyl acetate grafted vinyl chloride.

  In European patent application NO 312 968, the use of “hot melt” bonding films has been described for assembling elements of the structure of a ski. These films are mainly composed of a thermoplastic polymer. and an adhesion promoter such as a silane or an epoxy resin. The object of the invention is mainly to produce a ski, certain elements of which, by virtue of their composition, have high mechanical and aging properties, an excellent ability for molding, bonding and decoration. The ski according to the invention is produced by the assembly of several elements and is characterized in that at least one element of this assembly consists in part at least of a composition comprising at least one thermoplastic elastomer based on polyamide and at least one modified polyolefin and are such that the thermoplastic elastomer (s) represent at least 50% and preferably at least 60% of the total weight of elastomer (s)

  thermoplastic (s) and modified polyolefin (s).

  Polyamide-based thermoplastic or TPE elastomers can

  be random or block copolymers.

  The random copolymers are formed by the random sequence of the various constituents (monomers and / or prepolymers) while the block copolymers or blocks preferred by the applicant, are formed from blocks having a certain chain length of their various constituents. Polyamide-based copolymers are either polyesteramides or

polyetheramides.

  The block polyetheramides or polyether block amides may in particular result from the copolycondensation of polyamide sequences with reactive ends with polyether sequences with reactive ends, such as, inter alia: a) polyamide sequences at the ends of diamine chains with blocks

  polyoxyalkylenes with dicarboxylic chain ends.

  b) Polyamide sequences at the ends of dicarboxylic chains with 1 O polyoxyalkylene sequences at the ends of diamine chains obtained by cyanoethylation and hydrogenation of alpha, omega polyoxyalkylene sequences

  aliphatic dihydroxylates called polyetherdiols.

  c) Polyamide sequences containing dicarboxylic chain ends with polyetherdiols, called polyetheresteramides, which are particularly preferred by the

1 5 plaintiff.

  The composition and manufacture of such polyetheresteramides have been

  described in French patents No. 2,273,021 and 2,401,947 in particular.

  The number-average molecular mass of these polyamide blocks is generally between 500 and 10,000 and more particularly between 2,600 and 5,000 The polyamide blocks of the polyetheresteramides are preferably formed from aliphatic polyamide and / or from amorphous polyamide or from

  copolyamide resulting from the polycondensation of their monomers.

  The number average molecular weight of the polyethers is included

  generally between 200 and 6000 and more particularly between 600 and 3000.

  The polyether sequences most often consist of po-

  lytetramethylene glycol (PTMG), polyethylene glycol (PEG) and / or

polypropylene glycol (PPG).

  The inherent viscosity of polyetheresteramides is advantageously between 0.8 and 2.05 It is measured in metacresol at 20 C with a

  Initial concentration of 0.5 g of polymer per 100 g of metacresol.

  The polyetheresteramides can be formed from 5 to 85% by weight of polyether, and from 95 to 15% by weight of polyamide, and preferably from 30 to 85

  % by weight of polyether and from 70 to 15% by weight of polyamide.

  The polyetheresteramides preferred by the applicant are those in which the polyamide blocks consist essentially of PA-11, 12 and / or 12.12 and when a composition having antistatic properties is sought, polyetheresteramides are preferably used in which the polyether blocks are essentially made of polyethylene glycol

(PEG).

  By modified polyolefins is meant copolymers comprising: an ethylene or an α-olefin monomer or optionally a diolefin. at least one comonomer chosen from vinyl esters of saturated carboxylic acid, unsaturated mono and dicarboxylic acids, their esters, salts, anhydrides of saturated or unsaturated dicarboxylic acids 1 O The olefin represents at least 50% and of preferably at least 60% of the total weight of the copolymer, it being understood that the copolymers can be polymerized statistically or in sequence and have a linear structure

  or branched, for the polyolefins modified according to the invention.

  By way of example, mention may be made of: 1 5 * copolymers of ethylene and vinyl acetate (EVA), maleized or not, particularly preferred by the applicant, (maleic anhydride can be grafted or terpolymerized) containing from 2 to 40% by weight of vinyl acetate, from 0 to 0.5% by weight of grafted maleic anhydride or from O to 10% by weight of terpolymerized maleic anhydride relative to the total weight of the copolymer copolymers of ethylene and (meth) acrylic acid containing from 2 to% by weight of acid relative to the total weight of the copolymer * copolymers of ethylene, vinyl acetate and optionally (meth) acrylic acid and / or alkyl (meth) acrylate (such as glycidyl methacrylate) containing from 2 to 40% by weight of vinyl acetate and from 0 to 9% by weight of (meth) acrylic acid and / or alkyl (meth) acrylate * copolymers of ethylene, alkyl (meth) acrylate (such as methyl acrylate, ethyl, N- butyl) and optionally maleic anhydride containing from 2 to 40% by weight of alkyl (meth) acrylate and from 0 to 8% by weight of anhydride relative to the total weight of the copolymer. By modified polyolefins is meant also block copolymers based on styrene and in particular those consisting of polystyrene blocks and polybutadiene blocks (SBS), of polystyrene blocks and of blocks

  polyisoprene (SIS), polystyrene and poly (ethylene-

  Butylene) (SEBS) containing from 0.2 to 0.8% by weight of maleic anhydride and from 30 to 55% of styrene for SBS from 15 to 25% for SIS and from 13 to

32% for SEBS.

  Various other compositions can be incorporated into the compositions described above.

  constituents, such as fillers, pigments or dyes, various additives.

  Examples of fillers that may be mentioned are glass fibers, carbon fibers, aramids, talc, silica, kaolin, glass beads and fibers, ceramics, metallic fillers, metal salts and oxides , such as aluminum powder, calcium and manganese carbonates, ferrite powder,

titanium oxide.

  In general, up to 50% and preferably up to% by weight of fillers can be incorporated relative to the elastomer (s) compositions.

  thermoplastic (s) and modified polyolefin (s) proper.

  By way of example of additives, mention may be made of anti-UV agents, agents

release agents, impact modifiers.

  The compositions can in particular be prepared by compounding; the constituents, most often in the form of granules with an average diameter of less than 5 mm, are mixed in the molten state in general in a kneader

  a temperature between 190 and 250 OC.

  Because of their easy implementation, their good mechanical properties (especially resistance to cold shock, abrasion, tear resistance), their dimensional stability between -20 and 60 C, their good aging behavior as well as their excellent ability to bond and to decorate, the compositions according to the invention can be used in very diverse forms (molded or extruded parts, films, sheets, fibers) alone or for the production of complex or composite objects : rooms

overmolded, coextruded films.

  The molded or extruded parts can be obtained according to known molding and extrusion techniques, the processing temperatures being generally similar to those of the compounding of

  constituents of the compositions according to the invention (20 'C in general).

  The elements used in the composition of the ski include in particular the films or bonding sheets from the compositions They

  can be obtained by any known extrusion process such as extrusion-

  flat calendering, extrusion plastering, extrusion blow molding, temperature

  being generally between 190 and 250 ° C.

  According to Modem Plastics Encyclopedia, the term "film" is reserved for objects of planar section whose thickness is less than 250 gm and the term "sheet" for objects of greater thickness and up to several mm,

  but in everything that follows and for reasons of simplification, we can use

  read one or the other of the terms to simultaneously designate films and sheets.

  The films obtained from the compositions can be used as such but can also be used in the manufacture of multilayer films obtained for example by co-extrusion, hot lamination. The multilayer films particularly preferred by the applicant comprise: a layer of aliphatic polyamide (such as PA-6, PA-6 6, PA-il, PA-12, PA-12 12), of amorphous polyamide, of thermoplastic elastomer with 1 i O based on polyamide and / or copolymer of ethylene and vinyl alcohol

(EVOH)

  a layer of composition according to the invention.

  The process for manufacturing these composite materials can take place in 2 stages: 1 5 The co-extrusion of the bi-layer film is first carried out and then hot glued to the side of the composition layer according to the invention, on the support

  in synthetic material for example, by hot forming or thermoforming.

  These composite materials can be decorated using the sublimable ink transfer printing method and in particular according to the methods described in patent application FR 2596286. The decoration of these materials can also be carried out using other techniques such as by screen printing, painting or varnishing, hot transfer, pad printing, inkjet, laser marking, it being understood that the decoration techniques can be applied to the compositions according to the invention in any form (film, molded parts, fibers) These films can be glued on rigid parts of the ski and in particular on metal parts serving as reinforcement (such as cables, sheets) or on wooden parts as well as on synthetic materials preferably based

  of, covered or impregnated with epoxy resin (s) and / or polyester (s).

  The composite materials made up of the two-layer film described above and of a support impregnated with epoxy resin (s) and / or polyester (s), and / or polyurethane (s), possibly decorated, are particularly suitable for the

  production of ski tops according to the invention.

  The compositions in the form of single-layer films can also serve as co-extrusion binder for multilayer films making it possible to make

  adhere layers whose bonding is difficult or impossible.

  By way of example, mention may be made of the use of films of composition according to the invention as co-extrusion binder of a film based on polycarbonate (PC) on the one hand and of a film based on copolymer ethylene and

  vinyl alcohol (EVOH) on the other hand.

  The embodiments described below in detail will be better understood with reference to the appended figures, of which; Figure l shows a cross-sectional view of an example of a detailed ski structure; FIG. 2 represents a cross-sectional view of a ski, the structure of which has been simplified according to a particular embodiment of the invention; FIG. 3 represents a detailed cross-sectional view of a ski of another particular embodiment; Figure 4 shows an exploded perspective view of a ski; FIG. 5 represents a cross-sectional view of a ski according to a

last embodiment.

  As can be seen in Figure 1, a ski is generally made up of the assembly of several elements independently performing the necessary functions such as mechanical strength, protection, sliding, etc. Thus, modern skis generally have a uniting assembly the so-called "mechanical" elements which are in particular a core 3, lower and upper mechanical reinforcement elements 4, squares 5 and a sole 1, or sliding surface and an upper decoration and protection assembly 2 consisting of one or more multiple layers extending or not

  laterally along the ski edges.

  Figure 2 illustrates a specific example of application to an element

  superior decoration and protection 2 of the compositions according to the invention.

  In this particular case, this element consists of an upper layer 21 of polyamide 11, resistant to UV rays, to hot creep, and easily sublimable and of a lower layer 22 consisting of a composition of that described previously. The bilayer can advantageously be produced by coextrusion or hot plaxing for example It is then hot glued to the upper reinforcement impregnated with an epoxy resin and / or polyester, and / or polyurethane shown in FIG. 1 The operating conditions and the results d adhesion are those given in the following examples I to VII:

EXAMPLE I:

  1 In a single-screw extruder whose screw speed is adjusted to rpm, 60 parts of polyether esteramide (A 1) and 40 are compounded.

  parts of copolymer of ethylene and maleized vinyl acetate (B 1).

  The extrusion temperature is between 200 and 250 C and the flow

  of rextruder is set at 20 kg / h.

  At the outlet of the die, the composition obtained in the form of rods with an average particle size equal to approximately 3 mm has a melt index (MI) of 1.31

  measured at 190 C under a load of 2.16 kg according to ASTM D 1238.

  1 O The polyetheresteramide (A 1) used consists of 88% of sequences

  PA-12 (Mn = 5,000) and 12% PTMG (B 1) sequences (Mn = 650).

  The maleized EVA used contains 18% vinyl acetate and 0.27% maleic anhydride, its melting point is 86 C and its point

  Vicat measured according to standard D 1525 is equal to 61 C.

  1 5 In Table I, the following are indicated: the Shore D hardness (5 s) measured according to ISO standard 868

  the modulus of elasticity in bending at 20 C and the coefficient of stiffness

  fication between 20 and -20 C measured according to ASTM D 790 standard the tear resistance measured according to ISO 34 standard (method 2 0 B) (tear perpendicular to the injection) Izod impact resistance with notch measured according to the standard ISO the tensile breaking stress measured at -40 C according to the standard

ASTM D 638.

  for composition 1 1 and for constituents A 1 and B 1.

  We then proceed to the coextrusion of a two-layer sheet PA-

l 1 // composition 1 1.

  The co-extrusion conditions are as follows: extrusion temperatures: 3 0 of PA 11: 210 C / 230 C / 240 C / 240 C of 1 1: 205 C / 230 C / 230 C / 230 C die temperature: 245 C calender temperature: 50 C / 35 C / 50 C At the outlet of the die, a two-layer is obtained consisting: 3 5 of a layer of PA-11 (Mn = 20,000) of thickness equal to approximately 0.3 nim

  of a layer of composition 1 1 of thickness equal to approximately 0.5 mm.

  Then proceed to hot bonding of the above bi-layer film on an epoxy support consisting of textile sheets (glass fabric) impregnated with% epoxy resin based on bisphenol-A in the presence of an amine hardener of MDI type and a crosslinking accelerator. The bilayer is glued to the support in a mold at a temperature

  about 150 ° C under a pressure of 8 kg / cm 3 and then cooled before demolding.

  The adhesion of the bi-layer on the epoxy support is measured after 72

  hours in distilled water according to standard NFT 76-112.

  1 O The characteristics of the materials are gathered in Table I. The adhesion results gathered in Table II correspond to

  average values calculated from 5 tests.

  2 Compound under the same conditions as in I 1 a composition (I 2) consisting of 90 parts of I 1 and 10 parts of glass fibers of

average length equal to 4 mm.

  This composition is then co-extruded with PA-11 with the same characteristics as in M 1 The bi-layer obtained consists of a layer of PA-1 i with a thickness equal to approximately 0.3 mm

  of a layer of composition 1 2 with a thickness equal to approximately 0.5 mm.

  It is then bonded to an epoxy support under the same conditions

than in M 1.

  The adhesion results are collated in Table II.

  3 Compound under the same conditions as in I 1 a composition (I.3) consisting of 90 parts of I 1 and 10 parts of glass fibers of

average length equal to 4 mm.

  This composition is then co-extruded with PA-11 with the same characteristics as in M 1 The bi-layer obtained consists of a layer of PA-11 with a thickness equal to approximately 0.3 mm

  a layer of composition 13 with a thickness equal to approximately 0.5 mm.

  It is then bonded to an epoxy support under the same conditions

than 1 1.

  The adhesion results are collated in Table II.

  4 Compound under the same conditions as in 1 1 a composition

  (I.4) consisting of 80 parts of 1 1 and 20 parts of Ca CO 3.

  This composition is then co-extruded with PA-11 with the same characteristics as in 1 1 The bi-layer obtained consists of a layer of PA-11 with a thickness equal to approximately 0.3 mm

  a layer of composition 1 4 of thickness equal to about 0.5 mm.

EXAMPLE II:

  Under the same conditions as in 1 1, 60 parts of polyetheresteramide i A (A 1) and 40 parts of ethylene and maleized vinyl acetate copolymer (B 2) containing 28% of vinyl acetate are compounded and 0.2% maleic anhydride (melting point: 75 C: Vicat point: 57 C) The composition obtained (11) (M 1 = 1.89) is then co-extruded with PA-11 and then bonded to

  an epoxy support under the same conditions as in 1 1.

  The adhesion results are collated in Table II.

EXAMPLE III:

  Under the same conditions as in 1 1, 60 parts of polyetheresteramide (A 1) and 40 parts of ethylene-acetate copolymer are compounded.

  vinyl (B 3) containing 28% vinyl acetate (MI = 3).

  The composition (III) obtained (MI = 3.5) is then co-extruded with

  PA-11 then bonded to an epoxy support under the same conditions as in 1 1.

  The adhesion results are collated in Table II.

  EXAMPLE IV (Comparative): By way of comparison and according to patent application EP 312 968, compounding is carried out under the same conditions as in 1150 parts of polyetheresteramide (A 2), 1 part of silane, 19 parts of talc and 30 games of

tackifying resins.

  The polyetheresteramide A 2 consists of 50% of PA12 sequences

  (Mn = 2000) and 50% of PTMG sequences (Mn = 2000).

  The composition obtained (III) (MI = 4) is then co-extruded with

  PA-11 then bonded to an epoxy support under the same conditions as in 1 1.

  The adhesion results are collated in Table II.

EXAMPLE V:

  Under the same conditions as in 1 1, 80 parts of

  polyetheresteramide (A 1) and 20 parts of maleized SBS (B 4).

  Maleized SBS is a styrene / butadiene-1,3 / styrene block copolymer containing 30% styrene and 0.2% maleic anhydride and MI = 4. The composition (IV) obtained is then co-extruded with PA -11 then

  bonded to an epoxy support under the same conditions as in 1 1.

EXAMPLE VI:

  1 O Composition (III) is co-extruded with EVOH (containing 44%

  ethylene; d = 1.14; MI = 3.5; melting point: 164 C).

  The co-extrusion conditions are as follows: extrusion temperatures: from EVOH: 200 C / 220 C / 235 C from II: 200 C / 210 C / 220 C / 230 C die temperature: 220 C calender temperature: 50 C / 35 C / 50 C At the outlet of the die, a bi-layer is obtained consisting of: a layer of EVOH of thickness equal to approximately 0.3 mm,

  2 0 of a layer of composition III of thickness equal to about 0.8 mm.

EXAMPLE VII:

  Under the same conditions as in 11 L, 70 parts of

  polyetheresteramide A 4 and 30 parts of maleized EVA B 7.

  Polyetherestamide A 4 consists of 80% of PA-12 sequences

  (MN = 4,000) AND 20% of PTMG sequences (Mn = 1,000).

  Maleized EVA B 7 contains 14% vinyl acetate and 0.35% maleic anhydride Its melting temperature is 94 C and its Vicat point is 71 C.

  Composition VII obtained is then used as a co-binder.

  extrusion between EVOH and crystal polycarbon.

  The EVOH used has the same characteristics as that of Example VI.

  The crystal polycarbonate used is marketed by General Electric

Company, under the brand LEXAN 154.

  1 1 l The coextrusion conditions are as follows: extrusion temperatures: of the EVOH: 190 C / 200 C / 205 C / 210 of VII: 185 C / 190 C / 190 C / 190 C temperature of the crystal PC: 270 C / 275 C / 270 C / 270 C die temperature: 250 C calender temperature: 45 C / 50 C / 50 C At the end of the die, a two-layer is obtained consisting of: a layer of thick EVOH equal to about 0.3 mm of a layer of XII thickness equal to about 0.1 mm

  a layer of crystal PC with a thickness of approximately 0.3 mm.

  The peel is measured at 180 of the tri-layer on a 15 mm wide test tube by subjecting each of the outer layers to a traction (speed

tensile = 100 mm / min).

  The coat obtained, expressed in g / 10 mm,

is equal to 910.

TABLE I

  CHARACTERISTICS 1 1 l I II A 1 A 2 Bl B 3 Al + Bl Al + B 2 AI + B 3 Shore hardness D 50 55 55 70 40 31 26 Flexural modulus 215 226 221 460 75 40 22 CoeffRigidification 3.2 3.1 3.1 4.07 2.36 Tear Resistance (k N / m) 160 131 70 49.3 37.7 Izod Shock (k J / m 2) 4.8 4.7 5 2.7 2.5 Stress Failure (M Pa) 31 35.3 50 36 19.4 19.7

TABLE II

N ADHESIVE EXAMPLE (N / mm)

1.1 10

1.2 11.6

1.3 12.9

II 15.9

II 15.9

IV 9

  In the case of injected skiing, it is advantageous to use the film of the invention as a bonding film and more particularly, in the form of a tubular envelope 6 as shown in FIG. 3 In this case, the structured elements of the ski are arranged in a mold and a thermosetting foam is injected inside the tubular envelope. The expansion of the foam in the envelope creates the compaction of the ski elements, including reinforcements 4. expansion reaction is accompanied by an exothermic reaction which is generally sufficient to achieve the adhesion of the film to the

compacted elements.

  1 O Such a manufacturing process is described in French application N O 89

15665 of the plaintiff.

  The composition according to the invention also allows the manufacture of added molded parts such as the heel tips 7 or the spatulas 8 These parts are generally molded and can be loaded with glass fiber 1 5 for example They can be removably mounted on the ski body,

  especially for the spatula 8, as shown in Figure 4.

  Finally, provision can be made to insert internal damping elements of the composition of the invention into the structure of the ski. Constructions which can integrate such elements are described in the French applications for

  Patent NO 2611 518, 2615 404, 2615405, 2615406.

  FIG. 5 illustrates a nonlimiting embodiment of the invention o the damping elements 9 of the composition of the invention are located laterally between the lateral faces of the core 3 and the inclined lateral faces

from the top of the ski 2.

Claims (2)

CLAIMS 1 Ski consisting of an assembly of several elements including in particular a lower sliding surface (1), an upper decoration assembly (2), a core (3), internal mechanical reinforcement elements (4), lower edges (5), characterized in that at least one element of this assembly consists in part at least of a composition which comprises: * at least one thermoplastic elastomer based on polyamide, 1 O * at least one modified polyolefin chosen from random or block copolymers comprising: at least one comonomer chosen from vinyl esters of saturated carboxylic acid, unsaturated mono and dicarboxylic acids, their esters, salts, anhydrides of dicarboxylic acids, saturated or not. The olefin representing at least 50% and preferably at least 60% of the total weight of the copolymer, or the block copolymers based on styrene containing from 0.2 to 0.8% by weight of maleic anhydride. 2 Ski according to claim 1, characterized in that the thermoplastic elastomer (s) represent at least 50% and preferably at least 60% of the total weight of thermoplastic elastomer (s) and modified polyolefin (s). 3 Ski according to claim 1 or 2, characterized in that the thermoplastic elastomer, based on polyamide is a polyetheramide and preferably 2 5 a polyetheresteramide. 4 Ski according to claim 1 or 2 or 3, characterized in that the modified polyolefin is chosen from: * copolymers of ethylene and vinyl acetate, maleized or not, * copolymers of ethylene and of acid (meth ) acrylic, 30 * copolymers of ethylene, vinyl acetate and optionally (meth) acrylic acid and / or alkyl (meth) acrylate, * copolymers of ethylene, (meth) acrylate alkyl and optionally maleic anhydride, * SBS, SIS, and maleized SEBS. 3 5 5 Ski according to any one of the preceding claims, characterized in that the compositions contain additives and / or pigments or dyes, and / or up to 50% and preferably up to 40% by weight of fillers with respect to the polyamide-based thermoplastic elastomers (s) and to the modified polyolefin (s). 6 Ski according to any one of the preceding claims, characterized in that the element consisting at least in part of the composition of the mixture is a monolayer or multilayer film suitable for bonding. 7 Ski according to claim 6, characterized in that the monolayer or multilayer film is hot bonded to a support impregnated with epoxy resin (s) and / or polyester (s) and / or polyurethane (s). 1 O 8 Ski according to claim 7 characterized in that the element is a bi-layer film (2) composed of a layer of aliphatic polyamide (21) on which adheres a layer of the composition of the mixture (22). 9 Ski according to claim 8 characterized in that the aliphatic polyamide is a polyamide 11.   1 5 10 Ski according to claim 8 or 9 characterized in that the bilayer   constitutes a superior decorative and protective element (2).   11 Ski according to claims 1 to 5 characterized in that the element of the   composition of the mixture is a molded insert such as a nozzle heel (7) or a spatula (8).   2 0 12 Ski according to claims 1 to 5 characterized in that the element of the   composition of the mixture is an internal damping element (9).