Multilayer film and its uses

Abstract

The present invention relates to a multilayer film comprising: an adhesive layer A comprising at least one polyolefin modified by a carboxylic acid and / or one of its derivatives; an intermediate layer C comprising at least one styrenic block copolymer; a barrier layer B comprising at least one thermoplastic polyester elastomer; and its uses. Figure: None

Description

Title of the invention: Multilayer film and its uses FIELD OF INVENTION

[0001] The present invention relates to a multilayer film and its uses in particular for the preparation of laminates. TECHNOLOGICAL BACKGROUND

[0002] Various single- or multi-layer films, formulated from different polymers, are commercially available for bonding various substrates such as foams, metals, textiles, or plastics. The polymers are typically polyamides, polyolefins, polyamide / polyester copolymers, thermoplastic polyesters, etc.

[0003] In the automotive field, multilayer films can be used for bonding interior parts such as headliners, seat trim, decorative parts requiring assembly, or soundproofing components (car floor mats, trunk floor, engine hood, etc.). The films must be durable and withstand the conditions of use, particularly when exposed to high temperatures (parts near the engine).

[0004] There is therefore a need for new multilayer films exhibiting good mechanical and adhesive properties over time.

[0005] In particular, there is a need for new multilayer films exhibiting good cohesion after extrusion, and which do not delaminate over time.

[0006] In particular, there is a need for new multilayer films exhibiting good temperature resistance (for example, at a temperature greater than or equal to 120°C).

[0007] In particular, there is a need for new multilayer films that are easy to prepare and inexpensive. DESCRIPTION OF THE INVENTION

[0008] The present invention relates to a multilayer film comprising: - an adhesive layer A comprising at least one polyolefin modified by a carboxylic acid and / or by one of its derivatives; - an intermediate layer C comprising at least one styrenic block copolymer; - a barrier layer B comprising at least one thermoplastic polyester elastomer.

[0009] The multilayer film according to the invention advantageously exhibits good mechanical and adhesive properties over time.

[0010] The multilayer film according to the invention advantageously exhibits good cohesion after extrusion.

[0011] The multilayer film according to the invention also exhibits good temperature resistance (for example at a temperature greater than or equal to 120°C).

[0012] The multilayer film according to the invention can advantageously be prepared by a simple and inexpensive process.

[0013] The multilayer film according to the invention can advantageously be used in many applications, such as for example in the automotive field (engine hood for example).

[0014] The multilayer film according to the invention advantageously allows the bonding of various polar and non-polar substrates.

[0015] The multilayer film according to the invention advantageously demonstrates good cohesion between layers A and B without delamination. Multilayer film Adhesive layer

[0016] The adhesive layer A comprises at least one polyolefin modified by a carboxylic acid and / or by one of its derivatives.

[0017] The term "modified polyolefin" means either a copolymer of olefins and said carboxylic acid and / or derivatives, or a homopolymer or copolymer of olefin grafted by said carboxylic acid and / or derivatives.

[0018] Preferably, the polyolefin is a homopolymer or copolymer grafted by a carboxylic acid and / or by one of its derivatives.

[0019] Preferably, the content of carboxylic acid and / or one of its derivatives ranges from 0.1% to 2.0% by weight relative to the total weight of said modified polyolefin.

[0020] Derivatives of carboxylic acids include in particular esters, amides, salts, imides and anhydrides of said acids.

[0021] The carboxylic acid is preferably chosen from the group consisting of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, and mixtures thereof.

[0022] The carboxylic acid derivatives are preferably chosen from maleic anhydride, itaconic anhydride, dimethyl maleic anhydride.

[0023] Preferably, the adhesive layer A comprises at least one polyolefin modified (even more preferably grafted) by maleic acid or maleic anhydride, more preferably maleic anhydride.

[0024] Preferably, the total content of maleic acid or maleic anhydride ranges from 0.1% to 2% by weight relative to the total weight of said modified polyolefin.

[0025] Polyolefins modified by a carboxylic acid and / or one of its derivatives can be synthesized by conventional methods known to those skilled in the art, such as, for example, radical polymerization, metallocene-catalyzed polymerization or polymerization in the presence of a Ziegler-Natta catalyst.

[0026] Homopolymers (or copolymers) of grafted olefins can be prepared by reacting a pre-formed polyolefin with the compound to be grafted by heating, with or without a free radical-generating catalyst (such as an organic peroxide) and with or without a solvent. None of the constituent atoms of the grafted radical, often added by a radical reaction, are incorporated into the main chain of the polyolefin. The grafted radical is notably linked, as a pendant group, to certain repeating units of the main chain of the polyolefin. The polyolefin that is grafted can be either a homopolymer or a copolymer.

[0027] The polyolefin can be a homopolymer of C2-C20 alpha-olefins, preferably the polyolefin is selected from polyethylenes, polypropylenes, polybutylenes, and mixtures thereof.

[0028] Polyethylenes can include linear polyethylenes such as, for example, HDPE (High Density Polyethylene), linear low-density polyethylene (LLDPE), very low or ultra-low density polyethylene (VLDPE or ULDPE), and branched polyethylenes such as, for example, low-density polyethylene.

[0029] The polyolefin can be a copolymer of ethylene with a C3-20 alpha-olefin comonomer, or a copolymer of propylene with a C4-C20 alpha-olefin comonomer.

[0030] C3-C20 alpha-olefins can be selected from the group consisting of propylene, 1-butene, 1-hexene, 4-methyl-l-pentene, 1-octene, 1-decene, 1-octadecene and mixtures thereof.

[0031] C4-C20 alpha-olefins can be selected from the group consisting of 1-butene, 1-hexene, 4-methyl-l-pentene, 1-octene, 1-decene, 1-octadecene and mixtures thereof.

[0032] The modified polyolefin may have a melt flow index (or Melt Flow Index MFI) measured at 190°C and under a total weight of 2.16 kg, in accordance with ISO 1133, ranging from 0.5 g / 10 min to 30 g / 10 min.

[0033] The modified polyolefin may have a density ranging from 0.6 to 1.2 g / cm3, preferably from 0.7 to 1.0 g / cm3. The density is preferably measured according to ISO 1133.

[0034] The modified polyolefin preferably has a melting point of 100°C to 150°C. The melting point can be measured according to ASTM D3418.

[0035] Modified polyolefins according to the invention are, for example, commercially available from LyondellBasell, for example under the name Plexar™, or even at Mitsui under the name Admer ™, or the Bynel 4206 marketed by Dupont (maleic anhydride modified LLDPE), or the Orevac® 18360 marketed by Arkema (maleic anhydride grafted LLDPE).

[0036] Preferably, the adhesive layer A comprises a modified polyethylene (even more preferably grafted) with maleic anhydride.

[0037] The adhesive layer A preferably comprises more than 90% by weight of at least one modified polyolefin as defined above, preferably more than 95% by weight, and even more advantageously more than 99% by weight relative to the total weight of said adhesive layer.

[0038] The adhesive layer can have a total thickness ranging from 5 to 60 sqm, preferably from 15 to 50 sqm, and even more preferably from 20 to 40 sqm. Barrier layer

[0039] The barrier layer comprises a thermoplastic polyester elastomer.

[0040] The barrier layer makes it possible in particular to protect the bonded substrate and to make it impermeable to certain gases (example: air) and fluids (example: water).

[0041] The term "thermoplastic polyester elastomer" is well known to those skilled in the art, and is also designated by the acronym "TPC". It is a block copolymer comprising, in alternation, blocks or segments called hard or rigid, and blocks or segments called soft or flexible, with ester bonds in the hard blocks, and possibly ester and / or ether and / or carbonate bonds in the soft blocks.

[0042] The thermoplastic polyester elastomer can be of the polyester-polyester type (with in particular the soft segment comprising a polyester) or polyester-polyether type (with in particular the soft segment comprising a polyether) or polyester-polyester / polyether type (with in particular the soft segment comprising a polyester-polyether copolymer).

[0043] A thermoplastic polyester-polyester elastomer may comprise an aromatic polyester as a hard segment and an aliphatic polyester as a soft segment.

[0044] A thermoplastic polyester-polyether elastomer may comprise an aromatic polyester as a hard segment and an aliphatic polyether as a soft segment.

[0045] The hard segment of a thermoplastic polyester elastomer can be a segment comprising a polyester formed from an aromatic polyester prepared for example from an aromatic dicarboxylic acid and a diol.

[0046] Among aromatic dicarboxylic acids, examples may be given to terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, anthracene dicarboxylic acid, diphenyl-4,4-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, and sodium 3-sulfoisophthalate.

[0047] Aromatic polyester can be prepared from a single or a mixture of aromatic dicarboxylic acids.

[0048] The diol can be chosen from those having a molar mass less than or equal to 400 g / mol. For example, it can be chosen from: - aliphatic diols such as, for example, 1,4-butanediol, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol or mixtures thereof; - aromatic diols such as, for example, xylylene glycol, bis(p-hydroxy)diphenyl, bis(p-hydroxy)diphenylpropane, 2,2'-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4(2-hydroxyethoxy)phenyl]sulfone, 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 4,4'-hydroxy-p-terphenyl, or mixtures thereof; - their mixtures.

[0049] The aromatic polyester is preferably prepared from an aromatic dicarboxylic acid such as, for example, terephthalic acid, and an aliphatic diol such as, for example, 1,4-butanediol.

[0050] According to a preferred mode, the hard segment of the thermoplastic polyester elastomer comprises a polyester selected from polybutylene terephthalate, polyethylene terephthalate and polytrimethylene terephthalate, and even more preferably polybutylene terephthalate.

[0051] The soft segment of the thermoplastic polyester elastomer may comprise an aliphatic polyether and / or an aliphatic polyester, preferably an aliphatic polyether.

[0052] The aliphatic polyether can be a poly(ethylene oxide) glycol, a poly(propylene oxide) glycol, a poly(tetramethylene oxide) glycol, poly(hexamethylene glycol), a copolymer of ethylene oxide and propylene oxide, a copolymer of ethylene oxide glycol and tetrahydrofuran.

[0053] The aliphatic polyester can be a poly(e-caprolactone), a polyenanthractone, a polycaprolactone, a polybutylene adipate, a polyethylene adipate.

[0054] The thermoplastic polyester elastomer can be modified with an unsaturated carboxylic acid, such as, for example, acrylic acid, maleic acid, fumaric acid, or their derivatives.

[0055] According to a preferred embodiment, the soft segment of the thermoplastic polyester elastomer comprises an aliphatic polyether selected from poly(tetramethylene oxide) glycol or poly(hexamethylene glycol).

[0056] The hard segment content in the thermoplastic polyester elastomer of the barrier layer can range from 10% by weight to 60% by weight, preferably from 20% by weight to 40% by weight compared to 100% by weight of thermoplastic polyester elastomer.

[0057] The soft segment content in the thermoplastic polyester elastomer of the barrier layer can range from 30% to 90% by weight, preferably from 50% to 80% by weight compared to 100% by weight of thermoplastic polyester elastomer.

[0058] Preferably, the thermoplastic polyester elastomer is a thermoplastic polyester-polyether.

[0059] The melting temperature of the thermoplastic polyester elastomer of the barrier layer can be greater than or equal to 90°C, preferably greater than or equal to 150°C, and even more preferably greater than or equal to 180°C.

[0060] The melting temperature of the thermoplastic polyester elastomer of the barrier layer may be less than or equal to 250°C, preferably less than or equal to 220°C.

[0061] The melting temperature can be determined by DSC (scanning calorimeter).

[0062] The thermoplastic polyester elastomer can have a Shore D hardness ranging from 30 to 80, preferably from 40 to 70, and even more preferably from 40 to 60. The Shore D hardness can be measured as described in DIN ISO 7619-1.

[0063] The barrier layer may comprise one or more thermoplastic polyester elastomers as described above.

[0064] Thermoplastic polyester elastomers are marketed, for example, by Toray DuPont under the "Hytrel™" series or the "Arnitel™" series marketed by DSM. Examples include Arnitel EL630 (poly(ether-ester) copolymers) from DSM, and HYTREL® 6356 from DuPont.

[0065] The barrier layer may include at least one additive selected from the group consisting of pigments, fillers, dispersants, colorants, flame retardants, antioxidants, stabilizers, and mixtures thereof.

[0066] The total content of additives can range from 0% to 5%, preferably from 0.01% to 5%, and even more preferably from 0.01% to 2% by weight relative to the total weight of said barrier layer.

[0067] The barrier layer may comprise one or more non-elastomeric polymers, such as, for example, a polyolefin resin, a polystyrene resin, an ethylene-vinyl acetate copolymer.

[0068] Preferably, the barrier layer comprises more than 95% by weight of thermoplastic polyester elastomer as defined above, preferably more than 98% by weight, and even more advantageously more than 99% by weight, and even more preferably more than 99.9% by weight relative to the total weight of said barrier layer.

[0069] Preferably, the barrier layer does not comprise any polymers other than the thermoplastic polyester elastomer as defined above.

[0070] The barrier layer can have a total thickness ranging from 5 to 40 pm, preferably from 5 to 30 pm, and even more preferably from 10 to 25 pm.

[0071] According to one embodiment, the melting temperature of the barrier layer is higher than the melting temperature of the adhesive layer. This advantageously allows the adhesive layer to adhere to a substrate by heating it to a temperature lower than the melting temperature of the barrier layer. Thus, the adhesive layer is melted or softened sufficiently to adhere to the substrate while preventing the softening or melting of the barrier layer, and therefore maintaining the properties of the barrier layer. Intermediate layer C

[0072] The intermediate layer C comprises at least one styrenic block copolymer.

[0073] Preferably, layer C is an intermediate layer, bonded on one of its sides to layer A and on the other side layer B.

[0074] The styrene block copolymer is a copolymer comprising at least one styrene block, including in particular styrene triblock copolymers, styrene diblock copolymers, and mixtures thereof.

[0075] This styrene block copolymer has at least one block A that includes styrene and at least one block B that includes, for example, elastomeric conjugated dienes (e.g., hydrogenated and non-hydrogenated conjugated dienes), sesquiterpenes (e.g., hydrogenated and non-hydrogenated sesquiterpenes), and combinations thereof. Blocks A and B are linked to each other in various ways, allowing the resulting copolymer to adopt diverse structures, such as random, linear, branched, radial, star, comb, tapered, and combinations thereof.

[0076] The block copolymer can take different forms, including for example a linear block AB, a linear block ABA, a linear multiblock A-(BA)nB, where n is an integer of at least 3, a radial block (AB)nY, where Y is a multivalent compound and n is an integer of at least 3, a tetrablock copolymer, for example, ABAB, and a pentablock copolymer having an ABABA structure.

[0077] Among the suitable styrene A blocks, examples include styrene, alpha-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene and 2,4,6-trimethylstyrene, as well as their combinations.

[0078] Among the suitable conjugated diene elastomeric B blocks, examples include butadiene (e.g., polybutadiene), isoprene (e.g., polyisoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, as well as their hydrogenated versions, such as ethylene, propylene and butylene, and their combinations.

[0079] The styrenic block copolymer is preferably chosen from the group consisting of SB, SI, SEB, SEP, SBBS, SBS, SEBS, SEPS, SEEPS, SIBS, SIS, and mixtures thereof.

[0080] “SBBS” means a styrene-butadiene-butylene-styrene triblock copolymer. “SBS” means a styrene-butadiene-styrene triblock copolymer. “SEBS” means a styrene-ethylene-butylene-styrene triblock copolymer. “SEPS” means a styrene-ethylene-propylene-styrene triblock copolymer. “SEEPS” means a styrene-ethylene-ethylene-propylene-styrene triblock copolymer. “SIBS” means a styrene-isoprene-butadiene-styrene triblock copolymer. “SIS” means a styrene-isoprene-styrene triblock copolymer. “SB” means a styrene-butadiene diblock copolymer. “SI” means a styrene-isoprene diblock copolymer. “SEB” refers to a styrene-ethylene-butylene diblock copolymer. “SEP” refers to a styrene-ethylene-propylene diblock copolymer.

[0081] There are many styrenic block copolymers commercially available, such as for example KRATON D and G ® from Kraton Polymers, EUROPRENE Sol T ® from Versalis (Eni group), SOLPRENE ® from Dynasol Elastomers, SINOPEC ® from SINOPEC, or the Cawiton® range from Wittenburg.

[0082] Preferably, the styrenic block copolymer is chosen from SEBS, SEB, and mixtures thereof.

[0083] The intermediate layer C can have a total thickness ranging from 1 to 15 sqm, preferably from 5 to 10 sqm. Multilayer film

[0084] The multilayer film according to the invention comprises a barrier layer B and an adhesive layer A as defined above, and an intermediate layer C.

[0085] The aforementioned adhesive layer A may comprise one or more adhesive layers of identical or different natures.

[0086] The aforementioned barrier layer B may comprise one or more barrier layers of identical or different natures.

[0087] According to a preferred mode, the multilayer film comprises a single barrier layer B and a single adhesive layer A.

[0088] The total thickness of the multilayer film can range from 6 to 80 sqm, preferably from 10 to 70 sqm.

[0089] The present invention also relates to a method for preparing a multilayer film as described above. The method may include a coextrusion step, such as, for example, coextrusion-blowing, or flat die coextrusion.

[0090] As is known to those skilled in the art, the coextrusion-blowing process comprises: - the melting, in separate extruders, of the constituent compositions of the adhesive and barrier layers; then - the passage of the corresponding flows through an annular and concentric die, so as to form a multi-layered tubular bubble, then - radial expansion (relative to the annular channel) and stretching (in the axial direction) of the bubble; then - the cooling of the bubble.

[0091] The geometric characteristics of the dies, as well as the process parameters such as the radial expansion rate and the stretching speed, can be fixed in such a way as to obtain the desired thickness for the different constituent layers of the multilayer film. Laminates / uses

[0092] The present invention also relates to the use of the multilayer film as defined above for the preparation of laminate.

[0093] The present invention relates to the preparation of a laminate comprising: - the supply of a multilayer film as defined above; - bonding the multilayer film to a substrate.

[0094] The bonding step can be carried out by laminating the film onto the substrate and heating to a temperature below the melting temperature of the barrier layer (for example after or during deposition on substrate).

[0095] The adhesive layer is in particular the layer of the multilayer film which is in contact with the substrate to which it adheres, which advantageously allows the barrier layer of the multilayer film to adhere to the substrate.

[0096] The substrate can be of various kinds. It can be a substrate chosen from foams, textiles, plastics, metals, elastomers, thermosets, composites.

[0097] Textiles can be based on synthetic fibers, natural fibers, semi-synthetic fibers, inorganic fibers, or mixtures thereof.

[0098] Examples of synthetic fibers include polyamide-based copolymers (such as nylon), polyesters (such as polybutylene terephthalate PBT, polyethylene terephthalate PET), polyether ketones, and / or polyolefins.

[0099] The multilayer film is preferably intended to be applied to a textile. More particularly, the multilayer film is intended to be applied to a textile by means of its adhesive layer.

[0100] The present invention relates to the use of the multilayer film, or laminate, as defined above for the bonding / preparation of parts, for example parts found in automobiles.

[0101] The parts thus formed can be used for soundproofing in the automotive field (such as for example in the engine hood, the trunk floor, floor mats, ...), for safety, for decoration.

[0102] All the embodiments described above can be combined with each other.

[0103] In the context of the invention, "between x and y" or "ranging from x to y" means an interval in which the bounds x and y are included. For example, the range "between 0% and 25%" includes, in particular, the values ​​0% and 25%.

[0104] The invention is now described in the following embodiment examples which are given purely for illustrative purposes, and should not be interpreted to limit its scope. Examples

[0105] Example 1: Preparation of the multilayer film (Film Fl) by coextrusion blown film

[0106] Composition A is used as the constituent of the adhesive layer: a linear low-density polyethylene (LLDPE) modified with maleic anhydride (content less than 0.2%), having an MFR equal to 3 g / 10 min (190°C, / 2.16 kg).

[0107] A thermoplastic copolyester elastomer is used as composition B constituting the barrier layer: Melting range (ISO 11357-1 and -3): 207°C, Shore D hardness (ISO 868, 3s): 53, Melt flow index by mass MFR (ISO 1133): 9.68 g / lOmin (230°C; 21.6kg).

[0108] A thermoplastic elastomer compound comprising a SEBS is used as the constituent composition C of the intermediate layer.

[0109] The Fl film is manufactured on a blown coextrusion line with at least 3 screw extruders.

[0110] The process parameters are adjusted to manufacture a three-layer film comprising: - an adhesive layer with a thickness of 32 pm made up of composition A; - an intermediate layer with a thickness of 8 pm made up of composition C; - a barrier layer with a thickness of 20 pm made up of composition B.

[0111] Among the parameters usually set, we can mention: - Extruder temperature(s) of the adhesive layer between 170 and 210°C, - Extruder temperature(s) of the barrier layer between 210 and 250°C, - Processing temperatures between 210 and 250°C, - The inflation ratio (BUR: Blow Up Ratio) used is between 1.2 and 3.

[0112] The three-layer film thus obtained has a total thickness of 60 pm.

Claims

Demands

1. Multilayer film comprising: - an adhesive layer A comprising at least one polyolefin modified by a carboxylic acid and / or by one of its derivatives; - an intermediate layer C comprising at least one styrenic block copolymer; - a barrier layer B comprising at least one thermoplastic polyester elastomer.

2. Film according to claim 1, characterized in that the content of carboxylic acid and / or one of its derivatives of the modified polyolefin ranges from 0.1% to 2.0% by weight relative to the total weight of said modified polyolefin.

3. Film according to claim 1 or claim 2, characterized in that the carboxylic acid is selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, and mixtures thereof.

4. Film according to any one of claims 1 to 3, characterized in that the carboxylic acid derivatives are selected from maleic anhydride, itaconic anhydride, dimethyl maleic anhydride.

5. Film according to any one of claims 1 to 4, characterized in that the adhesive layer A comprises at least one polyolefin modified (preferably grafted) by maleic acid or maleic anhydride.

6. Film according to claim 5, characterized in that the total content of maleic acid or maleic anhydride in the modified polyolefin ranges from 0.1% to 2% by weight relative to the total weight of said modified polyolefin.

7. Film according to any one of claims 1 to 6, characterized in that the polyolefin is a homopolymer of C2-C20 alpha-olefins, preferably the polyolefin is selected from polyethylenes, polypropylenes, polybutylenes, and mixtures thereof.

8. Film according to any one of claims 1 to 7, characterized in that the adhesive layer A comprises a modified polyethylene (preferably grafted) with maleic anhydride.

9. Film according to any one of claims 1 to 8, characterized in that the thermoplastic polyester elastomer is of the polyester-polyester type (having in particular the soft segment comprising a polyester) or polyester-polyether type (having in particular the soft segment comprising a polyether) or polyester-polyester / polyether type (having in particular the soft segment comprising a polyester-polyether copolymer), preferably a thermoplastic polyester-polyether.

10. Film according to any one of claims 1 to 9, characterized in that the thermoplastic polyester elastomer has a Shore D hardness of 30 to 80, preferably 40 to 70, and even more preferably 40 to 60.

11. Film according to any one of claims 1 to 10, characterized in that the barrier layer comprises more than 95% by weight of thermoplastic polyester elastomer, preferably more than 98% by weight, and even more advantageously more than 99% by weight, and even more preferably more than 99.9% by weight relative to the total weight of said barrier layer.

12. Film according to any one of claims 1 to 11, characterized in that the styrenic block copolymer is selected from the group consisting of SB, SI, SEB, SEP, SBBS, SBS, SEBS, SEPS, SEEPS, SIBS, SIS, and mixtures thereof.

13. Film according to any one of claims 1 to 12, characterized in that the styrenic block copolymer is selected from SEBS, SEB, and mixtures thereof.

14. Laminate comprising the multilayer film according to any one of claims 1 to 13.

15. Use of the multilayer film according to any one of claims 1 to 13, or of the laminate according to claim 14, for the bonding / preparation of parts, for example of parts found in automobiles.