Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]

Definitions

• the present invention relates to a thermoformable multilayer film based on acrylic polymer for the protection of substrates and the objects thus obtained.
• plastic body parts such as bumpers, mirrors, the hood and, increasingly, all other parts such as doors and fenders.
• These parts have the advantage of being lighter than the same steel parts, of being insensitive to corrosion and of having better mechanical properties.
• These parts are produced by injection of molten material and / or thermoforming of thermoplastic material. There is, however, a technical difficulty in knowing that it is much more difficult to paint them than steel.
• One solution consists in covering these parts with a colored film, this film being able to be mono or multilayer.
• this film is placed at the bottom of a mold and then the molten plastic material (the substrate) is injected into it, after cooling and demolding, the part coated with the colored film is obtained, this is the technique of overmolding.
• the adhesion of the film is ensured by the contact of the molten plastic with the film causing the melting of the surface of the film on the side of the injection of the molten plastic and therefore welding. It is also possible to coextrude the substrate and the colored film, lay the substrate on the colored film or else hot press the substrate on the colored film and then optionally thermoform the whole.
• the present invention relates to these films and to the substrates coated according to this technique.
• US Pat. No. 5,514,427 proposes using the so-called "solvent cast” technique for uniformly dispersing the pigments, dyes and fillers in a multilayer film.
• the solvent cast technology firstly consists in producing a liquid composition of thermoplastic polymer in a solvent containing the polymers proper, the dispersion of pigments and the additives meeting a given specification. This liquid composition is then deposited regularly on a carrier strip. The latter is brought into a drying oven in which the solvents are extracted by evaporation and in which the composition is melted to form a continuous layer. The continuous film is then wound up.
• the structure of the film comprises, going from the inside (substrate side which is made of polyolefin or acrylonitrile butadiene styrene) outwards a layer of chlorinated polyolefin, an acrylic adhesive layer and a pigmented layer based on fluorinated polymer and methacrylate d 'alkyl.
• WO 99/37479 describes a multilayer film obtained by the technique called "solvent cast” and lamination which has respectively from the inside (substrate side) to the outside an adhesive layer of the type "pressure sensitive adhesive” (or sensitive adhesive pressure), a layer of opaque pigmented fluoropolymer where the fillers have no particular orientation and a transparent layer based on fluoropolymer.
• Patent EP 949120 proposes a multilayer film constituted from the inside towards the outside of a polymer support layer (polyolefin, acrylonitrile
• butadiene styrene, polyamide, etc. a base methacrylic layer, a pigmented fluorinated layer (without particular orientation) of color and a transparent fluorinated layer, this film then being able to be overmolded by different substrates, such as polyolefins or polyamides.
• thermoformable multilayer film obtained by lamination constituted from the inside towards the outside of an adhesive layer, of a pigmented color layer where the fillers do not have any particular orientation and of a transparent layer.
• US Pat. No. 5,707,697 describes an exterior bodywork that is decorated and weatherproof.
• This piece consists of a multi film layer obtained by the technique known as "solvent cast” then lamination and a substrate.
• the structure of the film comprises from the inside to the outside a layer of chlorinated polyolefin capable of adhering to a polyolefin substrate, a layer based on fluorinated polymer of pigmented color where the fillers do not have any particular orientation and a layer of transparent fluoropolymer with a shiny appearance.
• Patent WO 9640480 describes a multilayer structure which from the inside to the outside has a reinforcing layer (of ABS type) coated by coextrusion of an adhesion primer (acrylic), then of a colored layer consisting of a PVDF-based copolymer in admixture with an acrylic and a transparent surface layer consisting of a mixture of PVDF homopolymer with an acrylic.
• Patent WO 9403337 proposes a multilayer consisting of the interior towards the exterior of a substrate, of an adhesive layer consisting of a compound compatible with the substrate, of a reinforcing layer, of a colored layer which contains pigments in an acrylic, urethane or vinyl matrix and finally a transparent layer based on PVDF and PMMA having a composition gradient.
• the reinforcement layer may consist of PBT, PET, ABS, PVC, PA, polyester, PC, polyolefin, an ethylene copolymer and an alkyl (meth) acrylate, an acrylic polymer or d 'a mixture of at least any two of these polymers.
• US Patent 5658670 describes a bilayer film obtained by coextrusion and hot pressing of a layer of PVDF or derivatives and a layer of PA, polyurethane or polyolefin modified with an amine.
• the weak point is the adhesion of the layer of fluoropolymer to the other layers.
• the prior art has therefore proposed films in which the adhesion of the layer of fluoropolymer to the other layers is greatly improved.
• thermoformable multilayer film successively comprising: • a protective layer (A), • a transparent layer (B) comprising (by weight the total being 100%) 0 to 100% of a fluoropolymer (B1) and 100 to 0% of a polymer (B2) essentially consisting of (meth) acrylate units d alkyl,
• a layer (C) based on polyamide with amino terminations • a layer (D) consisting of a polyolefin functionalized with an unsaturated carboxylic acid anhydride,
• This film is obtained by coextrusion of the different layers, the layer (A) being able to be laminated according to the usual technique of thermoplastics. This film is then used to cover different substrates, for example by injecting the substrate in the molten state onto the multilayer film placed in the bottom of an injection mold, the layer (A) of the film being placed against the wall of the mold. .
• the layer (B) consists mainly of a functionalized acrylic polymer then we could replace the layers (C) and (D) with a single layer consisting of a copolymer of ethylene and an alkyl (meth) acrylate carrying an epoxy function.
• the prior art has not described such multilayers.
• Patent application JP 09 193189 A published on July 29, 1997 describes a film comprising 4 layers which from the inside to the outside are respectively a layer of polypropylene, a layer of charged polypropylene (pigments), a layer of a copolymer ethylene - glycidyl methacrylate and a transparent surface layer based on polymethyl methacrylate (PMMA).
• PMMA is used in the examples and in the description, functionalized PMMA is not clearly described, and all the acrylic polymers described are presented as equivalent. It will be seen in the comparative examples of the present invention that this is not the case.
• thermoformable multilayer film successively comprising:
• a layer (B) comprising (by weight, the total being 100%) 0 to 30% of a fluoropolymer (B1) and 100 to 70% of a functionalized polymer (B2) essentially consisting of (meth) acrylate units alkyl,
• This film is obtained by coextrusion or plaxing of the different layers, the layer (A) can be laminated according to the usual technique of thermoplastics. This film is then used to cover different substrates, for example by injecting the substrate in the molten state onto the multilayer film placed in the bottom of an injection mold, the layer (B) or the optional layer (A) of the film. being disposed against the wall of the mold.
• the present invention also relates to the substrates coated with these films.
• the protective layer (A) is a temporary layer making it possible to protect the layer (B) during the film handling, thermoforming and injection stages.
• This protective layer makes it possible to maintain or promote a given surface condition.
• This layer can be smooth or rough depending on the desired surface condition.
• This layer avoids the use of release agent capable of degrading the surface condition of (B).
• This layer advantageously has a thickness between 10 and 150 ⁇ m and preferably from 50 to 100 ⁇ m.
• the materials which can be used to produce this layer can be chosen from (i) saturated polyesters such as PET, PBT, copolyesters and polyetheresters and (ii) homopolymeric or copolymeric polyolefins such as polyethylenes and polypropylenes.
• the surface layer (B) is formed of a polymer or of a mixture of polymers making it possible to obtain a transparent, shiny surface, resistant to attacks of a chemical or external nature or to UV.
• This layer advantageously has a thickness of 10 to 1200 ⁇ m and preferably 70 to 500 ⁇ m. We will see later that this layer is not always transparent, it can be colored with pigments.
• PVDF polymers of vinylidene fluoride (VF2) and copolymers of vinylidene fluoride (VF2) preferably containing at least 50% by weight of VF2 and at least one other fluorinated monomer such as chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene (VF3), tetrafluoroethylene (TFE),
• CTFE chlorotrifluoroethylene
• HFP hexafluoropropylene
• VF3 trifluoroethylene
• TFE tetrafluoroethylene
• VF3 trifluoroethylene
• the copolymers and in particular terpolymers, associating the residues of the chlorotrifluoroethylene (CTFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and / or ethylene units and optionally VF2 and / or VF3 units.
• CTFE chlorotrifluoroethylene
• TFE tetrafluoroethylene
• HFP hexafluoropropylene
• B1 fluorinated polymers
• the polymer (B2) consists essentially of alkyl (meth) acrylate units, advantageously methyl methacrylate, and it is functionalized, that is to say that it comprises at least one functional group chosen from acid functions, acid chloride, alcohol, anhydride.
• the alcohol function can be provided by hydroxyethyl (meth) acrylate.
• the polymer (B2) is the polyalkyl methacrylate comprising units:
• R1 represents H or a linear or branched alkyl having from 1 to 20 carbon atoms; and R 2 identical or different from Ri when the latter does not represent H, represents a linear or branched alkyl having from 1 to 20 carbon atoms, and units:
• R 3 represents H or a linear or branched alkyl having from 1 to 20 carbon atoms, in acid form, or its anhydride derivatives or mixtures thereof.
• R 4 and R 5 identical or different, represent H or a linear or branched alkyl having from 1 to 20 carbon atoms. It would not go beyond the scope of the invention if the motif (3) were wholly or partly replaced by its imide derivative.
• the polymer (B2) comprises, in moles, up to 30% of unit (2), in acid form, or its anhydride derivative or their mixtures.
• the polymer (B2) comprises, in moles, up to 15% of unit (2), in acid form, or its anhydride derivative or their mixtures.
• the unit (1) is methyl methacrylate and the unit (2) is (meth) acrylic acid.
• the motif (1) is a mixture of methyl methacrylate and of another acrylate in respective proportions which can vary from 80/20 to 95/5. This other acrylate is for example methyl acrylate or ethyl acrylate.
• the polymers (B2) mentioned above can be prepared by any suitable method known in the art. We will cite for example the process described in patent EP 774471.
• (B2) also comprises at least one monomer chosen from acrylonitrile, butadiene, styrene, isoprene provided that the proportion of alkyl (meth) acrylate is at least 50% by moles.
• These polymers (B2) either consist of the monomers and optionally the comonomers mentioned above and do not contain an impact modifier or they additionally contain an acrylic impact modifier.
• the acrylic impact modifiers are, for example, random or block copolymers of at least one monomer chosen from styrene, butadiene, isoprene and at least one monomer chosen from acrylonitrile and alkyl (meth) acrylates, they can be of the core-shell type (also called core-shell).
• acrylic impact modifiers can be mixed with the polymer (B2) once prepared or be introduced during the polymerization of (B2) or prepared simultaneously during the polymerization of (B2).
• the amount of acrylic impact modifier can be for example from 0 to 30 parts per 100 to 70 parts of (B2) and advantageously from 5 to 20 parts per 95 to 20 parts of (B2). It would not be departing from the scope of the invention if (B2) were a mixture of two or more of the preceding polymers.
• Suitable polymers for (B2) are SUMIPEX TR ® from Sumitomo ® and OROGLAS HT121 ® from ATOGLAS and for (B1) KYNAR 720 ® from ATOFINA.
• This layer can contain different organic and / or inorganic fillers, for example UV absorbers from the TINUVIN ® family of Ciba Specialty chemicals, this layer can also contain pigments or dyes.
• This layer has very good resistance to the various fluids used in the automobile such as petrol, coolant, windshield washer fluid, brake fluid, engine oil and hydraulic transmission fluid. Very good conservation over time is obtained of the condition and surface appearance of the film.
• the layer (C) based on an ethylene copolymer, an alkyl (meth) acrylate and an unsaturated epoxide.
• unsaturated epoxides there may be mentioned: aliphatic glycidyl esters and ethers such as Pallyl glycidyl ether, vinyl glycidyl ether, glycidyl maleate and itaconate, glycidyl (meth) acrylate, and alicyclic glycidyl esters and ethers such as 2-cyclohexene-1 - glycidyl ether, cyclohexene-4,5-diglycidyl carboxylate, cyclohexene-4-glycidyl carboxylate, 5-norbomene-2-methyl-2-glycidyl carboxylate and endo cis-bicyclo (2,2,1) -5- heptene-2,3-diglycidyl dicarboxylate.
• aliphatic glycidyl esters and ethers such as Pallyl glycidyl ether, vinyl glycidyl
• alkyl (meth) acrylates By way of example of alkyl (meth) acrylates, mention may be made of those in which the alkyls can have up to 24 carbon atoms.
• alkyl acrylate or methacrylate are in particular methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate.
• copolymers of layer (C) can be copolymers obtained by radical polymerization of the monomers: ethylene, (meth) alkyl acrylate and unsaturated epoxide.
• this copolymer can comprise other monomers such as:
• alpha-olefins advantageously those having 3 to 30 carbon atoms, as examples of alpha olefins, mention may be made of propylene, 1-butene, 1 -pentene, 3-methyl-1 -butene , 1-hexene, 4-methyl-1 -pentene, 3-methyl-1 -pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, 1-dococene, 1-tetracocene, 1-hexacocene, 1-octacocene, and 1-triacontene; these alpha-olefins can be used alone or as a mixture of two or more than two, - vinyl esters of saturated carboxylic acids such as, for example, vinyl acetate or propionate.
• - dienes such as, for example, 1,4-hexadiene.
• copolymers of layer (C) can also be copolymers of ethylene and of an alkyl (meth) acrylate and optionally of an alpha-olefin or of a vinyl ester or of a diene on which graft the unsaturated epoxide.
• the grafting operation is known in itself.
• the copolymers of layer (C) are advantageously the ethylene / (meth) alkyl acrylate / unsaturated epoxide copolymers obtained by copolymerization of the monomers and not by grafting of the unsaturated epoxide. They advantageously contain from 5 to 40% by weight of alkyl (meth) acrylate, preferably 10 to 40% and better still from 20 to 35%.
• the proportion of epoxide can be between 0.5 and 10% by weight and preferably between 2 and 9%.
• the epoxide is advantageously glycidyl (meth) acrylate (GMA).
• GMA glycidyl (meth) acrylate
• the MFI abbreviation of Melt Flow Index or melt flow index
• melt flow index is advantageously between 5 and 100 (in g / 10 min at 190 ° C under 2.16 kg), the melting temperature is between 60 and 110 ° C.
• the layer (C) consisted of (i) an ethylene copolymer, an unsaturated epoxide and optionally an alkyl (meth) acrylate mixed with ( ii) a polyethylene homopolymer or a copolymer of ethylene and of at least one monomer chosen from alpha-olefins, alkyl (meth) acrylates, vinyl esters and dienes provided that at least one of the constituents (i) and (ii) contains an alkyl (meth) acrylate.
• the mixture (i) + (ii) contains from 5 to 40% by weight of alkyl (meth) acrylate, preferably 10 to 40% and better still from 20 to 35%.
• This layer advantageously has a thickness of 10 to 1200 ⁇ m and preferably 70 to 500 ⁇ m.
• the bonding layer (D) which makes it possible to bond with the substrate is a polyolefin
• the polyolefins have been defined in the layer (D). These materials have sufficient compatibility and affinity to allow bonding with the layer (D) and the substrate.
• Polypropylene is advantageously used. Materials which are perfectly suitable for the production of this layer are the polypropylenes 3050 BN1 and 3060 MN5 from the company Appryl.
• the thickness of this layer is advantageously between 400 and 1200 ⁇ m and preferably between 500 and 600 ⁇ m.
• This layer can contain different organic and / or inorganic fillers, for example UV absorbers from the TINUVIN ® family of Ciba Specialty chemicals, this layer may also contain pigments or dyes.
• the film of the invention is produced by coextrusion according to a usual technique of thermoplastics in which the molten material of the different layers is forced through flat dies arranged very close to each other, the association of the molten materials forms the multilayer film that '' it is cooled by passing over rollers at controlled temperature.
• thermoplastics in which the molten material of the different layers is forced through flat dies arranged very close to each other, the association of the molten materials forms the multilayer film that '' it is cooled by passing over rollers at controlled temperature.
• the MFIs of the different layers are chosen as close as possible, between 1 and 20 (at 230 ° C., 2.16 kg), the MFIs are advantageously between 4 and 7, this choice is up to the man of coextrusion profession.
• the multilayer film of the invention is useful for covering substrates either by overmolding, or by coextrusion, or by coating or even by hot pressing.
• the overmolding technique is used. If the mold is simple, the injection of the substrate in the molten state is enough to press the film against the wall of the mold, the film is then used as obtained. If the mold is of a more complicated shape, to avoid constraints in the film and to ensure good contact of the film with the walls of the mold, it is necessary to preform the film by thermoforming before putting it in the mold. We can use another mold of the same shape and using a part having the same shape but in positive we thermoform the film, we can also use the same mold which is used for the injection of the substrate.
• thermoforming temperature range with as wide an overlap area as possible.
• the different layers may contain fillers and additives provided that the properties of the upper layer (B) and the colors and color effects of the whole structure are not affected.
• the invention is particularly useful for covering polypropylene substrates.
• Example 1 (Example according to the invention)
• a plate of 1 mm is performed with a polypropylene PP 3060MN5 ATOFINA MVI (Melt Volume Index or melt index by volume in the molten state) 6.5 cm 3/1 Ominutes to 230 ° C under 2.16 kg as well as '' a 1 mm thick plate with a lotader® AX8900 (ethylene-methyl acrylate-glycidyl methacrylate copolymer at 25% by weight of acrylate and 8% by weight of GMA) from the company ATOFINA from MFI 6 g / 10 minutes at 190 ° C under 2.16 kg and a 0.3 mm plate of PMMA OROGLAS® HT121 (it contains 8% by weight of acrylic acid and 2% by weight of methyl acrylate) from the company ATOFINA from MFI 2 g / 10 minutes at 230 ° C under 3.8 kg.
• ATOFINA MVI Melt Volume Index or melt index by volume in the molten state
• the HT121 plate is brought into contact with the AX8900 lotader itself in contact with the PP 3060MN5.
• This structure is placed in a press at 240 ° C. in the following manner, 2 minutes of preheating, 2 minutes under 40 bars and 4 minutes of cooling under 40 bars. Samples are then cut into a 2 cm test tube to carry out a peel test at 20 mm / minute.
• the peeling force for the PP / lotader interface is 15.5 N / cm, the HT121 / Lotader interface being non-bootable.
• Example 2 (comparative)
• a plate of 1 mm is performed with a polypropylene PP 3060MN5 ATOFINA MFR of 6.5 cm 3/1 Ominutes to 230 ° C under 2.16 kg and a plate of 1 mm thick with a LOTADER AX8900 society ATOFINA from MFI 6 g / 10 minutes at 190 ° C under 2.16 kg and a 0.3 mm plate of PMMA OROGLAS® V825T from the company ATOFINA from MFI 2.5 g / 10 minutes at 230 ° C under 3.8 kg, this PMMA does not has no reactive function in its chain.
• the V825T plate is brought into contact with the AX8900 lotader itself in contact with the PP 3060MN5.
• This structure is placed in a press at 240 ° C. in the following manner, 2 minutes of preheating, 2 minutes under 40 bars and 4 minutes of cooling under 40 bars. Samples are then cut into a 2 cm test tube to carry out a peel test at 20 mm / minute.
• the peel strength for the PP / lotader interface is 11 N / cm the PMMA / Lotader interface has no adhesion.
• Example 3 (Example according to the invention)
• a plate of 1 mm is performed with a polypropylene PP 3060MN5 ATOFINA MFR of 6.5 cm 3/1 Ominutes to 230 ° C under 2.16 kg and a plate of 1 mm thick with a Lotader® AX8930 (copolymer ethylene-methyl acrylate-glycidyl methacrylate at 24% by weight of acrylate and 3% by weight of GMA) from the company ATOFINA of MFI 6 g / 10 minutes at 190 ° C. under 2.16 kg and a plate of 0.3 mm of PMMA OROGLAS® HT121 from the company ATOFINA from MFI 2 g / 10 minutes at 230 ° C under 3.8 kg.
• the HT121 plate is brought into contact with the AX8930 lotader itself in contact with the PP 3060MN5.
• This structure is placed in a press at 240 ° C. in the following manner, 2 minutes of preheating, 2 minutes under 40 bars and 4 minutes of cooling under 40 bars. Samples are then cut into a 2 cm test tube to carry out a peel test at 20 mm / minute. Strength of peeling for the PP / lotader interface is 12 N / cm, the HT121 / Lotader interface being non-bootable.
• a 1 mm plate is made with polypropylene PP 3060MN5 from ATOFINA of MFR 6.5 cm 3 / 10minutes at 230 ° C under 2.16 kg as well as a 1 mm thick plate with a lotader® AX8840 (ethylene copolymer - glycidyl methacrylate at 8% by weight of GMA) from the company ATOFINA from MFI 5 g / 10 minutes at 190 ° C. under 2.16 kg and a plate of 0.3 mm of PMMA OROGLAS HT121 from the company ATOFINA from MFI 2 g / 10 minutes at 230 ° C under 3.8 kg.
• the HT121 plate is brought into contact with the AX8840 lotader itself in contact with the PP 3060MN5.
• This structure is placed in a press at 240 ° C. in the following manner, 2 minutes of preheating, 2 minutes under 40 bars and 4 minutes of cooling under 40 bars. Samples are then cut into a 2 cm test tube to carry out a peel test at 20 mm / minute.
• the peeling force for the PP / lotader interface is 1.5 N / cm, the HT121 / Lotader interface being non-bootable.

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• 2002
  • 2002-11-29 JP JP2003547169A patent/JP2005534520A/ja not_active Ceased
  • 2002-11-29 EP EP02799762A patent/EP1448380A2/de not_active Withdrawn
  • 2002-11-29 AU AU2002364409A patent/AU2002364409A1/en not_active Abandoned
  • 2002-11-29 KR KR1020047008240A patent/KR100580906B1/ko not_active IP Right Cessation
  • 2002-11-29 CN CNA028239881A patent/CN1599665A/zh active Pending
  • 2002-11-29 WO PCT/FR2002/004107 patent/WO2003045689A2/fr active Application Filing
  • 2002-11-29 US US10/496,922 patent/US20050069710A1/en not_active Abandoned

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