HK1129870A - Method for decorating surfaces - Google Patents

Description

Method of decorating a surface

Technical Field

The invention relates to a method for decorating surfaces, wherein a single-layer or multi-layer film is applied by means of electromagnetic radiation.

Background

Plastic shaped articles (kunststoffformteies) can be joined to one another by a very wide range of plastic welding methods, such as high-frequency welding, heat-pulse welding, thermal contact welding, heated edge welding (heizkeilschwein β en) or by means of electromagnetic radiation, such as laser, IR or microwave radiation. In laser transmission welding (laserdurchtrahlschweii β en), a laser-transparent component (fugeteil) and a laser-absorbing joining fitting (fugepartner) are generally used. Laser radiation passes through the transmitter and encounters an adjacent absorbing molding(s) (() The moulding being melted by local heating. However, the laser beam passing through the joining parts during joining should not penetrate too deeply into the absorbent joining fitting and should cause the absorbent shaped article to melt itself in the surface region. This results in an advantageous local conversion of the laser beam into heat in the joining region. The expanding melt contacts the transfer (transfittierend) engaging the fitting and also locally melts the fitting. The contact pressure supports the formation of the joint. The heat is introduced in a targeted manner and cannot escape to the outside prematurely. Thermoplastic materials in the unfilled state (thermoplast) are as transparent as possible to laser light at the wavelengths typically used for laser transmission welding. The advantage over other welding methods is the very good optical appearance of the joint and the limited local heating of the joint area. The same applies to welding by means of IR radiation or other electromagnetic radiation.

It is known that shaped articles and films can be welded to one another by means of electromagnetic radiation, for example laser radiation (DE19542328A 1; DE19916786A 1; WO 02/055287). Thereby obtaining a structural joint. Methods of decorating surfaces in this manner have heretofore been unknown.

The decoration of surfaces can be used for various purposes:

a) the surface of shaped articles made by rapid prototyping or rapid manufacturing is often rough and aesthetically unappealing.

b) The same applies to shaped articles made from shaped materials reinforced with fibers or fillers.

c) It is often desirable to apply emblems, colored decorative elements, labels or indicia to the molded articles.

d) In addition, it is highly desirable to protect surfaces that are insufficiently scratch, weather, chemical or stress crack resistant under use conditions so that they do not show use marks and, for example, retain their gloss.

EP0568988a1 discloses that surface-resistant parts can be produced by in-mold injection molding (hinderspiratzen), the film being a protective layer made from a thermoplastic melt. Here, the film is already joined to the shaped article during manufacture. This method is not suitable for shaped articles made by rapid prototyping or rapid manufacturing.

Disclosure of Invention

The aim was therefore to develop a possible method: the surface is subsequently decorated in the case of the shaped article produced in the first step, for example to enable decoration of shaped articles that cannot be produced by means of injection molding (Spritzgie β en), or to enable the application of varied decorative elements or small-scale production.

This object is achieved by a process for the production of surface-decorated shaped articles, in which

a) Providing a shaped article, and

b) at least a portion of the surface of the shaped article is welded to the decorative film upon incidence of electromagnetic radiation.

Detailed Description

In one possible embodiment, the shaped article is made by rapid prototyping or rapid manufacturing. Here, a thin film is welded thereto to provide a member having a smooth surface. In addition, the film may satisfy additional decorative functions. The terms "Rapid Prototyping" and "Rapid manufacturing" refer to a mould-less process (i.e. a process without a preformed mould) operating layer by layer, in which regions of each powdered layer are selectively melted and solidified upon cooling. Examples thereof are selective laser sintering (US 6136948; WO96/06881), the SIV process described in WO01/38061, or the process known from EP-A-1015214. The latter two methods melt the powder using a surface infrared heating operation. The selectivity of the melting is achieved in the first method by applying the inhibitor and in the second method by means of a mask (Maske). Another process is described in DE-A-10311438; here, the energy required for melting is introduced by means of a microwave generator and is optionally achieved by applying a receptor (Suszeptor). Further suitable processes are those which operate with absorbents present in powders or applied by the inkjet method, as described in the german patent applications DE102004012682.8, DE102004012683.6 and DE 102004020452.7. A large laser bandwidth can be used for the action of the electromagnetic energy, but planar action of the electromagnetic energy is also suitable.

The powders used in these processes can be prepared by milling the shaped mass, preferably at low temperatures. The abrasive material may then be classified to remove coarse or very fine particles. Mechanical after-treatment for rounding the particles can also be carried out subsequently, for example in a high-speed mixer. It is suggested according to the prior art to treat the powder thus obtained with a flow improver, for example with fumed silica, which is mixed by dry blending. Preferably, the powder thus obtained has a number average particle size of 40 to 120 μm and less than 10m²BET surface area in g.

In another possible embodiment, the shaped article consists of a shaped mass reinforced with fibers and/or fillers. Suitable fibers and fillers and suitable compositions are further described below. In particular in the case of relatively high filling levels, the fillers and reinforcing materials are pressed out of the surface, which results in a rough surface. In addition, the surface may be subject to weathering or dusting, especially when not optimally bonded with fillers and reinforcing materials. This is prevented by the method according to the invention.

In another possible embodiment, a film containing emblems, colored decorative elements or indicia or a representation label is applied to any type of shaped article. Shaped articles may be made by extrusion, injection molding (Spritzgie β en), or any other shaping method.

Finally, in another possible embodiment, the film is applied to a surface which, under the conditions of use, exhibits traces of use due to, for example, its inadequate resistance to scratching, weathering, chemicals or stress cracking. Suitable film materials are known; examples are further set forth below.

The shaped articles used according to the invention are generally composed of thermoplastic polymers, but may also be formed from ceramics, natural substances such as wood or leather, thermosetting substances (Duroplaste) or metals. They may also have a multi-component, e.g. multi-layer, composition.

Suitable thermoplastic polymers are all thermoplastic substances (thermoplasts) known to the person skilled in the art. Suitable thermoplastic polymers are described, for example, in Kunststoff-Taschenbuch, published by Saechtling, 25 th edition, Hanser-Verlag, Munchen, 1992, in particular chapter 4 and the references cited therein, and Kunststoff-Handbuch, eds G.Becker and D.Braun, volumes 1 to 11, Hanser-Verlag, Munchen, 1966-.

The following may be mentioned as examples of suitable thermoplastic materials: polyalkylene oxides, Polycarbonates (PC), polyesters such as polybutylene terephthalate (PBT) or polyethylene terephthalate (PET), polyolefins such as polyethylene or polypropylene, poly (meth) acrylates, polyamides, vinylaromatic (co) polymers such as styrene, impact-toughness-modified polystyrenes such as HI-PS, or ASA, ABS or AES polymers, polyarylene ethers such as polyphenylene ether (PPE), polysulfones, polyurethanes, polylactides, halogen-containing polymers, imino (imino) containing polymers, cellulose esters, silicone polymers and thermoplastic elastomers. It is also possible to use mixtures of different thermoplastic substances as material for the plastic shaped articles. These mixtures may be single-phase or multi-phase polymer blends.

Polyoxyalkylene homo-or copolymers, in particular (co) Polyoxymethylenes (POMs), and processes for their preparation are known per se to the person skilled in the art and are described in the literature. Suitable materials may be found, for example, in trademarks(BASF AG) commercially available. Quite typically, these polymers have at least 50 mol% of the repeating unit-CH in the polymer backbone₂O-is formed. The homopolymers are generally preferably made by passing formaldehyde or formaldehyde in the presence of a suitable catalystPolymerization of trioxane. Polyoxymethylene copolymers and polyoxymethylene terpolymers are preferred. Preferred polyoxymethylene (co) polymers have a melting point of at least 150 ℃ and a molecular weight (weight average) M of 5000-_w. Particular preference is given to end-group-stabilized polyoxymethylene polymers having C-C bonds at the ends of the chains.

Suitable polycarbonates are known per se and are obtainable, for example, by interfacial polycondensation according to DE-B-1300266 or by reaction of diphenyl carbonate with bisphenols according to DE-A-1495730. The preferred bisphenol is 2, 2-bis (4-hydroxyphenyl) propane, commonly referred to as bisphenol A. Suitable polycarbonates are described, for example, in the trade mark(GE Plastics B.V., Netherlands).

Suitable polyesters are likewise known per se and are described in the literature. They contain aromatic rings in the main chain, which rings are derived from aromatic dicarboxylic acids. The aromatic ring may also be substituted, for example, by halogen, e.g. chlorine or bromine, or by C₁-C₄Alkyl radicals such as the methyl, ethyl, isopropyl or n-propyl radical or the n-, isobutyl or tert-butyl radical. Polyesters may be prepared by reacting aromatic dicarboxylic acids, esters thereof or other ester-forming derivatives thereof with aliphatic dihydroxy compounds in a manner known per se. Naphthalene dicarboxylic acid, terephthalic acid and isophthalic acid or mixtures thereof may be mentioned as preferred dicarboxylic acids. Up to 30 mol% of the aromatic dicarboxylic acids may be replaced by aliphatic or cycloaliphatic dicarboxylic acids, for example adipic acid, azelaic acid, sebacic acid, dodecanedioic acids or cyclohexanedicarboxylic acids. Among the aliphatic dihydroxy compounds, preference is given to diols having from 2 to 6 carbon atoms, in particular 1, 2-ethanediol, 1, 4-butanediol, 1, 6-hexanediol, 1, 4-cyclohexanedimethanol and neopentyl glycol or mixtures thereof. Polyalkylene terephthalates derived from alkane diols having 2 to 6C atoms may be mentioned as particularly preferred polyesters. Of these, polyethylene terephthalate (PET), polyethylene naphthalate (polyethylene naphthalate), polybutylene naphthalate and paryleneButylene glycol acid ester (PBT).

Suitable polyolefins are primarily polyethylene and polypropylene and copolymers based on ethylene or propylene, optionally with higher alpha-olefins. Polyolefins are understood as meaning ethylene-propylene elastomers and ethylene-propylene terpolymers.

Mention may be made, in particular, of poly (meth) acrylates, for example those available under the trade mark(BASF AG) orPolymethyl methacrylate (PMMA) obtained under GmbH) and copolymers based on methyl methacrylate with up to 40% by weight of other copolymerizable monomers, for example n-butyl acrylate, t-butyl acrylate or 2-ethylhexyl acrylate. In the context of the present invention, these are also understood to mean impact-toughness-modified poly (meth) acrylates and mixtures of poly (meth) acrylates impact-modified with polyacrylate rubbers and SAN polymers (for example commercial products from BASF AG)

In the context of the present invention, all known polyamides, including polyetheramides and polyether block amides and blends thereof, are to be understood as being among the polyamides. Examples of these are polyamides derived from lactams having 7 to 13 ring members, such as polycaprolactam, polycapryllactam and polylaurolactam, and polyamides obtained by reacting dicarboxylic acids with diamines. The polyamide may also be wholly or partially aromatic; the latter is commonly referred to as PPA.

Alkane dicarboxylic acids and aromatic dicarboxylic acids having 6 to 22, in particular 6 to 12, carbon atoms can be used as dicarboxylic acids. Adipic acid, azelaic acid, sebacic acid, dodecanedioic acid (═ decanedicarboxylic acid) and terephthalic acid and/or isophthalic acid may be mentioned here as acids.

Alkanediamines having 6 to 12, in particular 6 to 8, carbon atoms and m-xylylenediamine, bis (4-aminophenyl) methane, bis (4-aminocyclohexyl) methane, 2-bis (4-aminophenyl) propane or 2, 2-bis (4-aminocyclohexyl) propane are particularly suitable as diamines.

Preferred polyamides are polyhexamethylene adipamide (PA66), polyhexamethylene sebacamide (PA610), polyhexamethylene decanedicarboxamide (PA 612), polycaprolactam (PA 6), in particular copolyamides 6/66 having a proportion of 5 to 95% by weight of caprolactam units and polylaurolactam (PA12) and PA1, and furthermore copolyamides based on caprolactam, terephthalic acid and hexamethylenediamine or on terephthalic acid, adipic acid and hexamethylenediamine.

Mention will also be made of polyamides (PA46) which can be obtained, for example, by condensation of 1, 4-diaminobutane with adipic acid at elevated temperature. Processes for the preparation of polyamides of this structure are described, for example, in EP-A0038094, EP-A0038582 and EP-A0039524.

Further examples are polyamides obtainable by copolymerization of two or more of the abovementioned monomers, or mixtures of more polyamides, where the mixing ratio is arbitrary.

The following non-limiting list contains the polyamides set forth in the context of the present invention and additional polyamides (monomers set forth in parentheses): PA46 (tetramethylenediamine, adipic acid), PA66 (hexamethylenediamine, adipic acid), PA69 (hexamethylenediamine, azelaic acid), PA610 (hexamethylenediamine, sebacic acid), PA612 (hexamethylenediamine, decane dicarboxylic acid), PA613 (hexamethylenediamine, undecane dicarboxylic acid), PA614 (hexamethylenediamine, dodecane dicarboxylic acid), PA1212(1, 12-dodecane diamine, decane dicarboxylic acid), PA1313(1, 13-diaminotridecane, undecane dicarboxylic acid), PA MXD6 (m-xylylenediamine, adipic acid), PA T (trimethylhexamethylenediamine, terephthalic acid), PA4 (pyrrolidone), PA6 (. epsilon. -caprolactam), PA7 (ethanolic lactam (Ethanol)actam)), PA8 (caprylocactam), PA9 (9-aminononanoic acid), PA11 (11-aminoundecanoic acid), PA12 (lauryllactam). These polyamides and their preparation are known. The person skilled in the art can find details of their preparation in the following documents: ullmannsderTechnischen Chemie, 4 th edition, volume 19, pages 39-54, Verlag Chemie, Weinheim1980, and Ullmann's Encyclopedia of Industrial Chemistry, volume A21, pages 179-206, VCH Verlag, Weinheim 1992, and Stoeckhere, Kunststofflexikon, 8 th edition, pages 425-428, Hanser Verlag, Munchen 1992 (keyword "polyamine", et al).

Other suitable thermoplastic materials are vinyl aromatic (co) polymers. The molecular weight of these polymers, known per se and commercially available, is generally 1500-.

Mention may be made here, as being typical only, of vinylaromatic (co) polymers of styrene, chlorostyrene, α -methylstyrene and p-methylstyrene; comonomers such as (meth) acrylonitrile or (meth) acrylates can also be present in minor proportions (preferably not more than 30% by weight, in particular not more than 8% by weight). Particularly preferred vinylaromatic (co) polymers are polystyrene, styrene-acrylonitrile copolymers (SAN) and impact-toughness-modified polystyrene (HIPS ═ high-impact polystyrene). Of course, mixtures of these polymers may also be used. The preparation can be carried out by the process described in EP-A-0302485.

In addition, ASA, ABS and AES polymers (ASA acrylonitrile-styrene-acrylate, ABS acrylonitrile-butadiene-styrene, AES acrylonitrile-EPDM rubber-styrene) are particularly preferred. These impact-resistant vinylaromatic polymers comprise at least one rubbery elastomeric graft polymer and a thermoplastic polymer (matrix polymer). In general, styrene/acrylonitrile polymers (SAN) are considered as matrix materials. It is preferred to use as graft polymers for the rubbers diene rubbers (ABS) which contain dienes, for example butadiene or isoprene, alkyl acrylate rubbers based on alkyl acrylates, for example n-butyl acrylate and 2-ethylhexyl acrylate, EPDM rubbers based on ethylene, propylene and dienes or mixtures of these rubbers or rubber monomers.

The preparation of suitable ABS polymers is described in detail, for example, in DE-A10026858 or DE-A19728629. For the preparation of ASA polymers, reference may be made, for example, to EP-A0099532. Information on the preparation of AES polymers is disclosed in, for example, US3,055,859 or US4,224,419. Polyarylene ethers are preferably understood as meaning polyarylene ethers per se, polyarylene ether sulfides, polyarylene ether sulfones or polyarylene ether ketones. The arylene groups thereof may be the same or different and represent, independently of one another, an aryl group having 6 to 18C atoms. Examples of suitable arylene groups are phenylene, biphenylene, terphenylene, 1, 5-naphthylene, 1, 6-naphthylene, 1, 5-anthracenylene, 9, 10-anthracenylene or 2, 6-anthracenylene. Of these, 1, 4-phenylene and 4, 4' -biphenylene are preferable. These aryl groups are preferably unsubstituted. However, they may carry one or more substituents. Suitable polyphenylene ethers may be available under the trademark PPO(GE Plastics B.V., Netherlands).

Polyarylene ethers are known per se or can be prepared by methods known per se.

Preferred process conditions for the synthesis of polyarylene ether sulfones or polyarylene ether ketones are described, for example, in EP-A0113112 and EP-A0135130. Suitable polyphenylene ether sulfones may be found, for example, in the trademarkE (BASF AG) and suitable polyphenylene ether ketones are available under the trademark Polyphenylene Ether (R)(Degussa GmbH) was obtained commercially.

In addition, polyurethanes, polyisocyanurates and polyureas are suitable materials for the manufacture of plastic shaped articles. Flexible, semi-rigid or rigid, thermoplastic or crosslinked polyisocyanate polyaddition reaction products, such as polyurethanes, polyisocyanurates and/or polyureas, are generally known. Their preparation is widely described and generally proceeds under generally known conditions by reaction of isocyanates with isocyanate-reactive compounds. The reaction is preferably carried out in the presence of a catalyst and/or promoter.

Aromatic, araliphatic, aliphatic and/or cycloaliphatic organic isocyanates, preferably diisocyanates, known per se are suitable as isocyanates.

For example, compounds which are generally known to have a molecular weight of from 60 to 10000g/mol and a functionality of from 1 to 8, preferably from 2 to 6, in the case of thermoplastic polyurethanes having a functionality of about 2 can be used as compounds which react toward isocyanates, for example polyols having a molecular weight of 500-10000g/mol, such as polyether polyols, polyester polyols and polyether polyester polyols, and/or diols, triols and/or polyols having a molecular weight of less than 500 g/mol.

Polylactides (polylactides), such as lactic acid polymers, are known per se and can be prepared by methods known per se.

In addition to polylactide, copolymers or block copolymers based on lactic acid and further monomers may also be used. Generally, linear polylactides are used. However, branched lactic acid polymers may also be used. For example, polyfunctional acids or alcohols may act as branching agents.

For example, vinyl chloride polymers may be mentioned as suitable halogen-containing polymers, in particular polyvinyl chloride (PVC), such as rigid PVC and flexible PVC, and copolymers of vinyl chloride, such as PVC-U molding compounds. Furthermore, fluoropolymers are suitable, in particular Polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoropropylene copolymers (FEP), copolymers of tetrafluoroethylene with perfluoroalkyl vinyl ethers, ethylene-tetrafluoroethylene copolymers (ETFE), polyvinylidene 1, 1-difluoroethylene (PVDF), polyvinyl fluoride (PVF), Polychlorotrifluoroethylene (PCTFE) and ethylene-chlorotrifluoroethylene copolymers (ECTFE).

Polymers containing imino groups (imidigreppenhalog) are in particular polyimides, polyetherimides and polyamideimides.

Suitable cellulose esters are, for example, cellulose acetate, cellulose acetobutyrate and cellulose propionate.

In addition, silicone polymers are also suitable as thermoplastic substances. In particular, silicone rubbers are suitable. These are generally polyorganosiloxanes having groups capable of crosslinking reactions. Such polymers are described, for example, inChemie Lexikon, CD-ROM version 1.0, Thieme Verlag Stuttgart 1995.

Finally, compounds of the type consisting of thermoplastic elastomers (TPE) can also be used. TPEs can be processed as thermoplastics but have elastomeric properties. TPE block copolymers, TPE graft copolymers and segmented TPE copolymers comprising two or more monomeric building blocks are suitable. Particularly suitable TPEs are thermoplastic polyurethane elastomers (TPE-U or TPU), styrene oligomeric block copolymers (TPE-S) such as SBS (styrene-butadiene-styrene block copolymer) and SEBS (styrene-ethylene-butylene-styrene block copolymer, obtainable by hydrogenation of SBS), thermoplastic polyolefin elastomers (TPE-O), thermoplastic polyester elastomers (TPE-E), thermoplastic polyamide elastomers (TPE-A) and in particular thermoplastic vulcanizates (TPE-V). Details of TPEs can be found by those skilled in the art in G.Holden et al, Thermoplastic Elastomers, 2 nd edition, Hanser Verlag, Munich 1996. The shaped articles may furthermore comprise conventional additives and processing aids.

Suitable additives and processing aids are, for example, lubricants or mold release agents, rubbers, antioxidants, light stabilizers, antistatics, flameproofing agents or fibrous or pulverulent fillers or reinforcing materials, and further additives or mixtures thereof.

Suitable lubricants and mold-release agents are, for example, stearic acid, stearyl alcohol, stearates or stearamides, silicone oils, metal stearates, montan waxes and waxes based on polyethylene and polypropylene.

Suitable antioxidants (thermostabilizers) are, for example, sterically hindered phenols, hydroquinones, aromatic amines, phosphites, variously substituted representatives of these classes and mixtures thereof.

Suitable light stabilizers are, for example, various substituted resorcinols, salicylates, benzotriazoles, benzophenones and HALS (hindered amine light stabilizers).

Suitable antistatic agents are, for example, amine derivatives such as N, N-bis (hydroxyalkyl) -alkylamines or-alkyleneamines, polyethylene glycol esters or glyceryl mono-and distearates and mixtures thereof.

Suitable flame retardants are, for example, halogen-containing compounds known to the person skilled in the art, alone or together with antimony trioxide, or phosphorus-containing compounds, magnesium hydroxide, red phosphorus and other conventional compounds or mixtures thereof. These include, for example, the phosphorus compounds disclosed in DE-A19632675, or the phosphorus compounds disclosed in Encyclopedia of Chemical Technology, eds R.Kirk and D.Othmer, Vol.10, 3 rd edition, Wiley, New York, 1980, page 340-420, for example phosphates, for example triaryl phosphates such as tricresyl phosphate, phosphites, for example triaryl phosphites or phosphonites. Bis (2, 4-di-tert-butylphenyl) phenylphosphonite, tris (2, 4-di-tert-butylphenyl) phosphonite, tetrakis (2, 4-di-tert-butyl-6-methylphenyl) -4, 4 ' -biphenylene diphosphonite, tetrakis (2, 4-di-tert-butylphenyl) -4, 4 ' -biphenylene diphosphonite, tetrakis (2, 4-dimethylphenyl) -1, 4-phenylene diphosphonite, tetrakis (2, 4-di-tert-butylphenyl) -1, 6-hexylene diphosphonite and/or tetrakis (3, 5-dimethyl-4-hydroxyphenyl) -4, 4 ' -biphenylene diphosphonite or tetrakis (3, 5-di-tert-butyl-4-hydroxyphenyl) -4, 4' -biphenylene diphosphonites are generally used as phosphonites.

In addition, inorganic flame retardants based on, in particular, magnesium hydroxides or carbonates, inorganic and organoboron compounds, such as boric acid, sodium borate, boron oxide, sodium tetraphenylborate and tribenzylborate, nitrogen-containing flame retardants, such as Iminophosphorane (Iminophosphorane), melamine cyanurate and ammonium polyphosphate and melamine phosphate are suitable (see also Encyclopedia of chemical technology, ibid.). In addition, mixtures with antidripping agents, such as Teflon or high molecular weight polystyrene, are also suitable as flameproofing agents.

Mention may be made of carbon fibers or glass fibers in the form of glass fabrics, glass mats or rovings, engraved glass and glass beads, glass fibers being particularly preferred as examples of fibrous or pulverulent fillers and reinforcing materials. The glass fibers used may comprise E-, A-or C-glass and are preferably treated with, for example, epoxy-, silane-, aminosilane-or polyurethane-based sizes and adhesion promoters based on functionalized silanes. The introduction of the glass fibers can be carried out in the form of short glass fibers and in the form of continuous strands (rovings).

For example, amorphous silica, whiskers, alumina fibers, magnesium carbonate (chalk), powdered quartz, Mica (Glimmer), Mica (Mica), bentonite, talc, feldspar or, in particular, calcium silicates, such as wollastonite and kaolin, are suitable as particulate fillers.

Fibrous, pulverulent or particulate fillers and reinforcing materials are generally used in amounts of from 1 to 60% by weight and preferably from 10 to 50% by weight, based on the shaped article.

The following embodiments of the invention are possible when welding by means of electromagnetic radiation:

shaped articles or films which absorb electromagnetic radiation in the wavelength range used without additives, or

-generating the absorption of electromagnetic radiation by adding an absorbing additive.

In both cases, one of the two components is transparent to the electromagnetic radiation used and the other component absorbs the radiation. In each case, the radiation is incident through a component that is transparent to the radiation.

The film used may be a monolayer film; in this case it consists of a material that produces a strong bond to the material of the shaped article. If a strong bond cannot be obtained with a single layer film due to insufficient material compatibility, two layers of film can be used — the bonding of one film layer to the shaped article is optimized. The film may also contain additional layers if the application requires it. The production of these multilayer films, for example by coextrusion, is state of the art.

Generally, the thin film is no more than 2000 μm, no more than 1600 μm, no more than 1200 μm, no more than 1000 μm, no more than 900 μm, no more than 800 μm, no more than 700 μm, or no more than 600 μm thick, with a minimum thickness of 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm.

In a preferred embodiment, the film or the outer-facing layer thereof (nach au β en hingerichtet) consists of a molding compound based on a semicrystalline polyamide.

The semi-crystalline polyamide is not subject to any restrictions. Here, predominantly suitable are aliphatic homo-and copolymers, such as PA46, PA66, PA88, PA610, PA612, PA810, PA1010, PA1012, PA1212, PA6, PA7, PA8, PA9, PA10, PA11 and PA 12. (the characterization of polyamides corresponds to international standards, the first number (Ziffer) referring to the number of carbon atoms of the starting diamine and the last number referring to the number of C atoms of the dicarboxylic acid if only one number is mentioned, this means that alpha, omega-aminocarboxylic acids or lactams derived therefrom are used as starting material; furthermore, reference may be made to H.Dominghaus, Die Kunststoffe und ihre Eigenschafen, page 272, et al, VDI-Verlag, 1976.)

If copolyamides are used, these may contain, for example, adipic acid, sebacic acid, suberic acid, isophthalic acid, terephthalic acid, naphthalene-2, 6-dicarboxylic acid, etc., as co-acids(s) (II)) Or bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, trimethylhexamethylenediamine, hexamethylenediamine and the likeAs a co-diamine (Codiamin). It is likewise possible to incorporate lactams, such as caprolactam or lauryllactam, or aminocarboxylic acids, such as omega-aminoundecanoic acid, as co-components.

The preparation of these polyamides is known (for example D.B. Jacobs, J.Zimmermann, Polymerization Processes, p.424-467, Interscience Publishers, New York, 1977; DE-AS 2152194).

In addition, mixed aliphatic/aromatic polycondensates as described, for example, in U.S. Pat. Nos. 4163101, 4603166, 4831108, 5112685, 5436294 and 5447980 and EP-A-0309095 are also suitable as polyamides. These are generally polycondensates: the monomers thereof are selected from aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, aliphatic dicarboxylic acids such as adipic acid, aliphatic diamines such as hexamethylenediamine, nonamethylenediamine, dodecamethylenediamine and 2-methyl-1, 5-pentanediamine, and lactams or omega-aminocarboxylic acids such as caprolactam, laurolactam and omega-aminoundecanoic acid. The content of aromatic monomer units in the polycondensate is generally at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45% or about 50%, based on the sum of all monomer units. These polycondensates are commonly referred to as "polyphthalamides" or "PPAs". Further suitable polyamides are poly (ether ester amides) or poly (ether amides); these products are described, for example, in DE-OSS2523991, 2712987 and 3006961.

The semi-crystalline polyamide has a melting enthalpy of at least 8J/g, preferably at least 10J/g, particularly preferably at least 12J/g and particularly preferably at least 16J/g, measured by the DSC method according to ISO 11357 with the integration of the 2 nd heating and melting peak.

The polyamide molding material may comprise one of these polyamides or a plurality of them as a mixture. In addition, up to 40% by weight of other thermoplastics may be present, provided that they do not interfere with the adhesion, in particular the rubber which becomes impact-resistant, for example ethylene/propylene or ethylene/propylene/diene copolymers, polypentenes, polyoctenes, alkenyl aromatics and aliphatic olefins orRandom or block copolymers of dienes (EP-A-0261748), or of polymers having ｃA glass transition temperature T_g<Tough and resilient core/shell rubbers of (meth) acrylate, butadiene or styrene/butadiene rubbers at 10 ℃, the core may be crosslinked and may consist of styrene and/or methyl methacrylate and/or further unsaturated monomers (DE-OSS 2144528, 3728685).

Auxiliaries and additives conventionally used for polyamides, such as flameproofing agents, stabilizers, UV absorbers, plasticizers, processing aids, fillers, in particular for increasing the electrical conductivity, nanofillers, pigments, dyes, nucleating agents, etc., can be added to the polyamide moulding material. The amount of the agent should be metered so as not to seriously adversely affect the desired properties. For most applications, it is desirable that the polyamide molding material is sufficiently transparent at the layer thicknesses used.

In a preferred embodiment, the monomer units of the polyamide derived from diamines, dicarboxylic acids or lactams (or aminocarboxylic acids) have on average at least 8C atoms and particularly preferably at least 9C atoms.

In the context of the present invention, particularly suitable polyamides are:

polyamides starting from 1, 12-dodecanedioic acid and 4,4 '-diaminodicyclohexylmethane (PA PACM12), in particular from 4, 4' -diaminodicyclohexylmethane with a trans, trans-isomer ratio of 35 to 65%;

-PA612, PA1010, PA1012, PA11, PA12, PA1212 and mixtures thereof;

-a copolyamide consisting of the following monomer combination:

a) from 65 to 99 mol%, preferably from 75 to 98 mol%, particularly preferably from 80 to 97 mol% and particularly preferably from 85 to 96 mol%, of a mixture of essentially equimolar amounts of aliphatic linear diamines and aliphatic linear dicarboxylic acids, which is present as a salt if desired and the diamines and dicarboxylic acids are additionally calculated separately in each case in the calculation of the composition, with the proviso that the mixture of diamines and dicarboxylic acids contains on average from 8 to 12C atoms and preferably from 9 to 11C atoms per monomer;

b) from 1 to 35 mol%, preferably from 2 to 25 mol%, particularly preferably from 3 to 20 mol% and particularly preferably from 4 to 15 mol%, of a mixture of essentially equimolar cycloaliphatic diamines and dicarboxylic acids;

-a copolyamide consisting of the following monomer combination:

a) from 50 to 100 parts by weight, preferably from 60 to 98 parts by weight, particularly preferably from 70 to 95 parts by weight and particularly preferably from 75 to 90 parts by weight of a polyamide, which can be prepared from the following monomers:

α)70 to 100 mol%, preferably 75 to 99 mol%, particularly preferably 80 to 98 mol% and particularly preferably 85 to 97 mol% of m-and/or p-xylylenediamine, and

β) from 0 to 30 mol%, preferably from 1 to 25 mol%, particularly preferably from 2 to 20 mol% and particularly preferably from 3 to 15 mol%, of further diamines having from 6 to 14C atoms, the mol% data being based here on the sum of the diamines, and

γ) from 70 to 100 mol%, preferably from 75 to 99 mol%, particularly preferably from 80 to 98 mol% and particularly preferably from 85 to 97 mol%, of an aliphatic dicarboxylic acid having from 10 to 18C atoms, and

δ)0 to 30 mol%, preferably 1 to 25 mol%, particularly preferably 2 to 20 mol% and particularly preferably 3 to 15 mol% of further dicarboxylic acids having 6 to 9C atoms, the mol% data being based here on the sum of the dicarboxylic acids;

b) from 0 to 50 parts by weight, preferably from 2 to 40 parts by weight, particularly preferably from 5 to 30 parts by weight and particularly preferably from 10 to 25 parts by weight of another polyamide, preferably a polyamide having on average at least 8C atoms in the monomer units, the parts by weight of a) and b) adding up to 100.

In a further preferred embodiment, the film or the outward layer thereof consists of a shaped mass based on: fluoropolymers such as polyvinylidene 1, 1-difluoride (PVDF), ethylene/tetrafluoroethylene copolymers (ETFE) or terpolymers based on ethylene, tetrafluoroethylene and a third monomer usually containing fluorine and introduced mainly for lowering the melting point. These products are commercially available.

In another preferred embodiment, the film or the outward layer thereof consists of a polyester-or polyolefin-based molding compound. Suitable polyesters are, for example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene 2, 6-naphthalate, polypropylene 2, 6-naphthalate or polybutylene 2, 6-naphthalate, with polyethylene (in particular HDPE, LDPE and LLDPE) and polypropylene (isotactic or syndiotactic homopolymers and copolymers with ethylene and/or 1-butene, here preferably random copolymers) being suitable as polyolefins.

In the case of an inwardly facing film layer acting as an adhesion promoter, a known molding compound suitable for the selected material combination is selected. Adhesion promoters which are generally used are, for example, polyolefins modified with unsaturated carboxylic acids or unsaturated anhydrides. A series of these products are available under the trade markAndthe following were obtained commercially.

Other known adhesion promoters include polymers of the shaped article and the outward film layer, and optionally, a compatibilizing agent.

Additives that absorb electromagnetic radiation are prior art. The absorbing additive may be, for example, carbon black. Other suitable absorption additives are bone char, graphite, other carbon particles, copper hydroxide phosphate (KHP), dyes, pigments or metal powders. Interference pigments such as those described in EP-A-0797511 are also very suitable; corresponding products under the trade markAnd (5) selling the product. Additives as described in WO00/20157 and WO02/38677 (e.g.) Or product seriesAdditives of IR (BASF AG) are also very suitable.

In addition, the following are also suitable: mica or mica pigments, titanium dioxide, kaolin, antimony (III) oxide, metallic pigments, pigments based on bismuth oxychloride (e.g. from Merck's Biflair series, high gloss pigments), indium tin oxide (nano ITO powder from Nanogate Technologies GmbH or AdNano from Degussa)^TM ITO)、AdNano^TMZinc oxide (Degussa), lanthanum hexaboride, antimony tin oxide and commercially available flame retardants including melamine cyanurate or phosphorus, preferably phosphate, phosphite, phosphonite or elemental (red) phosphorus.

If it is intended to avoid adversely affecting the natural color, the absorber preferably comprises interference pigments, particularly preferably the Iridins LS series or from MerckThe interference pigment of (1).

The carbon black may be prepared by a furnace black process, a gas black process or a flame black process, preferably by a furnace black process. The primary particle size is from 10 to 100nm, preferably from 20 to 60nm, and the particle distribution can be narrow or broad. BET surface area according to DIN 53601 of 10 to 600m²Per g, preferably from 70 to 400m²(ii) in terms of/g. The carbon black particles may be oxidatively post-treated for adjusting surface functionality. They may be rendered hydrophobic (e.g., Printex 55 or flame black 101 from Degussa) or hydrophilic (e.g., farrbu β FW20 or Printex 150T from Degussa). They may be highly structured or less structured; thereby describing the degree of aggregation of the primary particles. By using special conductive carbon blacks, the conductivity of the components produced from the powder according to the invention can be adjusted. By using beaded carbon black, better dispersion can be utilized in both wet and dry mixing processes. The use of carbon black dispersions may also be advantageous.

Bone char is a mineral black pigment containing elemental carbon. It contains 70-90% calcium phosphate and 30-10% carbon. The density is usually 2.3-2.8 g/ml.

The absorber may also comprise mixtures of organic and/or inorganic pigments, flame retardants or other colorants, each of which does not absorb or poorly absorbs at wavelengths of 100-3000nm, but in combination absorbs the incoming electromagnetic energy used in the method according to the invention sufficiently well.

The concentration of the absorption additive in the molding compound is generally from 0.05 to 20% by weight, preferably from 0.1 to 5% by weight and particularly preferably from 0.2 to 1.5% by weight.

According to the prior art, it is proposed to perform welding under contact pressure.

Electromagnetic radiation is not limited in terms of frequency range. It may be, for example, microwave radiation, IR radiation or, preferably, laser radiation.

The laser radiation used in the method according to the invention typically has a wavelength of 150-.

In principle, all conventional lasers are suitable, such as gas lasers and solid-state lasers. Examples of gas lasers are (typical wavelengths of emitted radiation are indicated in parentheses): CO 2₂Laser (10600nm), argon laser (488nm and 514.5nm), helium-neon laser (543nm, 632.8nm, 1150nm), krypton laser (330-; examples of solid-state lasers are (typical wavelengths of emitted radiation are indicated in parentheses): nd: YAG laser (Nd)³⁺：Y₃Al₅O₁₂) (1064nm), high power diode laser (800-₂Excimer laser (157nm), ArF excimer laser (193nm), KrCl excimer laser (222nm), KrF excimer laser (248nm), XeCl excimer laser (308nm), XeF excimer laser (351nm), and Nd having multiple frequencies of 532nm (double frequency), 355nm (triple frequency), or 266nm (quadruple frequency): YAG laser.

The lasers used are generally operated at a power of from 1 to 200, preferably from 5 to 100 and in particular from 10 to 50, watts.

The energy density of the laser used is described in the literature as the so-called "energy per unit length" and is generally 0.1 to 50J/mm in the present invention. The actual energy density is defined as the power introduced/weld area produced. This value is equivalent to the ratio of energy per unit length to the width of the weld seam produced. The actual energy density of the laser used is usually 0.01 to 25J/mm². The selected energy density depends not only on the reflective properties of the transparent body but also, in particular, on whether the plastic shaped articles to be joined contain fillers or reinforcing materials or other substances which strongly absorb or scatter the laser light. For polymers with low reflection and no filler or reinforcing material, the energy density is generally from 1 to 20, in particular from 3 to 10J/mm. For polymers containing fillers or reinforcements, they are generally from 3 to 50, in particular from 5 to 20J/mm.

Corresponding lasers which can be used in the process according to the invention are commercially available.

Particularly preferred lasers emit in the short-wave infrared range. The particularly preferred laser is a solid state laser, particularly Nd: YAG laser (1064nm) and high power diode laser (800-.

If the shaped article absorbs the electromagnetic radiation used, the radiation is incident through the film. In this case, the radiation of the film is sufficiently transparent.

However, shaped articles and absorbent monolayer films transparent to radiation may also be used; in this case, the radiation is incident through the shaped article.

In another embodiment, the inner layer (i.e., against the shaped article) to which it is applied is an absorbent multilayer film. In this case, the radiation may be incident through the film. However, if the shaped article is sufficiently transparent, radiation may also be incident through the shaped article.

In the case of a transparent film or outer layer, it is advantageous if the film or outer layer does not melt together. Thus, the contact pressure does not produce any marks on the surface. Where it is advantageous to adjust the melting and softening ranges of the outer layer or film (in the case of the single-layer embodiment), the possible adhesion promoter layer and the shaped article with respect to one another. Preferably, the adhesion promoting layer has a melting or softening point range lower than that of the (tiefer) outer layer. In the case of a monolayer film, it is preferred if the melting or softening point range of the material of the shaped article is low.

The film (in the case of a single layer embodiment) or the outer layer (i.e. the outward-facing layer of the multilayer film) can meet a very wide range of requirements. It may have a protective function with good scratch resistance, UV stability, thermal stability or chemical resistance, or if it is sufficiently transparent, it may be printed on the back, with the result that the print cannot be removed or wiped off. For example, by means of the process according to the invention, polyolefin surfaces, for example bottles, can be provided with a film, for example in the form of a label, without pretreatment. The application of the emblem or protective film is feasible just as the application of surface decoration or inscriptions or markings of safety-relevant parts or of original evidence or statements or safety information. By means of this technique even relatively small batches can be produced easily and reliably.

When welding, the film may be pressed onto it by means of a small ball or roller. The light beam may be directed through a sufficiently transparent pressure roller. Alternatively, the light beam can also be temporarily directed to the rear or between two rollers. The film may also be drawn onto the shaped article by means of vacuum or joined by means of a combination of pressure rollers and vacuum.

In a particularly suitable embodiment, the laser beam is focused by a rotatable glass spherical mirror which simultaneously acts as a mechanical pressure means. With this variant of the method, it is also possible to weld complex parts with three-dimensional joint seams. A gas-filled rotatable glass spherical mirror introduces a contact pressure onto the joining area. The contact pressure point is continuously present on the axis of the optical system, so that the laser radiation is incident only where the contact pressure is present. This ensures a high welding quality even in the case of complex three-dimensional geometries.

Claims (6)

1. A process for producing a surface-decorated shaped article, wherein

a) Providing a shaped article, and

b) at least a portion of the surface of the shaped article is welded to the decorative film with the incidence of electromagnetic radiation.

2. A method according to claim 1, characterized in that: shaped articles are manufactured by a mould-less process operating layer by layer.

3. A method according to claim 1, characterized in that: the shaped articles comprise from 1 to 60% by weight of fillers and/or reinforcing materials.

4. A method according to any of the preceding claims, characterized in that the film is single-or multi-layered.

5. Method according to any one of the preceding claims, characterized in that the film or the outward layer of the film consists of a shaped material based on a semi-crystalline polyamide, fluoropolymer, polyester or polyolefin.

6. A method according to any of the preceding claims, characterized in that the electromagnetic radiation is laser radiation.