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CN-122029023-A - Method for producing a composite part comprising a step of non-contact application of a liquid coating composition

CN122029023ACN 122029023 ACN122029023 ACN 122029023ACN-122029023-A

Abstract

The invention relates to a method for producing a composite component with improved composite adhesion, wherein the composite component comprises a support, a layer (B) and at least one polyurethane layer in direct contact with the layer (B). The invention also relates to composite parts having improved composite adhesion.

Inventors

  • B. Herzberg
  • F. SCHUSTER

Assignees

  • 科思创德国股份有限公司

Dates

Publication Date
20260512
Application Date
20241010
Priority Date
20231017

Claims (15)

  1. 1. Method for producing a composite part comprising A) A carrier made of the thermoplastic composition (Z), B) A layer (B) formed in such a manner as to cover at least a part of the surface in direct contact with the support, C) A polyurethane layer in direct contact with layer (B), The method comprises the following steps of (I) Injecting a melt of the thermoplastic composition (Z) into the mold cavity, followed by cooling to form a carrier, (Ii) Opening the mold cavity, and optionally removing the carrier from the mold cavity, (Iii) Applying non-contact onto a carrier at least one liquid coating composition, wherein the liquid coating composition comprises at least one polyfunctional H-reactive compound (H1) and/or polyisocyanate component (P1), and wherein if the liquid coating composition comprises a solvent, removing the solvent after non-contact application, (Iv) Optionally at least partially curing the coating composition, (V) (va) if the support remains in the mould cavity in method step (ii), closing the mould to create a gap, or introducing the support together with the optionally at least partially cured coating composition into a second mould cavity in the mould having a larger void size than the first mould cavity, thereby creating a gap, (Vb) if the support is removed from the mould cavity in method step (ii), introducing the support together with the optionally at least partially cured coating composition into the mould cavity of the mould to create a gap, And wherein for cases (va) and (vb), the support together with the optionally at least partially cured coating composition is arranged in such a way that the optionally at least partially cured coating composition faces the gap, (Vi) Injecting a reactive polyurethane raw material mixture containing the following components into the gap between the optionally at least partially cured coating composition and the mold surface At least one polyisocyanate component (P2), -At least one polyfunctional H-active compound (H2), and Optionally at least one polyurethane additive and/or processing aid, Wherein the polyurethane raw material mixture and optionally the at least partially cured coating composition are cured in contact with each other, wherein the polyurethane raw material mixture is cured to form a dense polyurethane layer or polyurethane foam layer, the coating composition is cured to form layer (B), (Vii) The composite part is released from the mold cavity.
  2. 2. The method of claim 1, wherein the layer (B) is formed in a form covering a portion of the surface, and the carrier is at least partially in direct contact with the polyurethane layer at a location where the layer (B) is not present.
  3. 3. The process according to claim 1 or 2, wherein the thermoplastic composition (Z) comprises A) At least 95.0 wt.% of an aromatic polycarbonate having a phenolic OH content of 230 ppm to 1500 ppm, and B) 0 to 5.0% by weight of at least one polymer additive.
  4. 4. A process according to claim 3, wherein the thermoplastic composition (Z) consists of components a) and B).
  5. 5. The method according to any one of claims 1 to 4, wherein the wall thickness of the carrier is 0.5mm to 10mm at least at one location.
  6. 6. The method according to any one of claims 1 to 5, wherein the at least one liquid coating composition is applied in method step (iii) by spraying, flow coating or digital printing methods.
  7. 7. A method according to any one of claims 1 to 6, wherein the spatial configuration of layer (B) is predetermined by a digital image and the digital image is transferred directly onto the carrier by a printing machine.
  8. 8. The method of any one of claims 1 to 7, wherein the liquid coating composition comprises the following components: b1 A polyfunctional H-reactive compound (H1) and/or a polyisocyanate component (P1), B2 At least one optional functional component selected from the group consisting of colorants, conductive additives, and additives having radar and/or LiDAR transparency, B3 Optionally a solvent, and B4 Optionally a humectant.
  9. 9. The method of claim 8, wherein the liquid coating composition comprises component B2).
  10. 10. A method according to any of claims 1 to 9, characterized in that a reactive polyurethane raw material mixture with a solvent content of at most 10 wt%, preferably at most 2wt%, more preferably at most 1wt% of lean solvent is used, based on the paint part.
  11. 11. The method according to any one of claims 1 to 9, characterized in that a solvent-free reactive polyurethane raw material mixture is used.
  12. 12. A process according to any one of claims 1 to 11, wherein the pot life of the reactive polyurethane raw material mixture is at most 1 minute, preferably at most 30 seconds, more preferably at most 10 seconds.
  13. 13. The process according to any one of claims 1 to 12, wherein the polymerization in process step (vi) is carried out under high pressure.
  14. 14. A composite part made according to the method of any one of claims 1 to 6 or 8 to 13, comprising A) A carrier made of the thermoplastic composition (Z), B) A layer (B) formed in such a manner as to cover at least a part of the surface in direct contact with the support, C) A polyurethane layer in direct contact with layer (B), Characterized in that the spatial configuration of the layer (B) is predetermined by a digital image and the digital image is transferred directly onto the carrier by means of a printing machine.
  15. 15. The composite component of claim 14, which is an interior or exterior component of a rail vehicle, an aircraft, or a motor vehicle.

Description

Method for producing a composite part comprising a step of non-contact application of a liquid coating composition The invention relates to a method for producing a composite component with improved composite adhesion, wherein the composite component comprises a carrier, a layer formed in such a way as to cover at least part of the surface, which layer is applied to the carrier in a contactless manner by using a liquid coating composition, and at least one polyurethane layer in direct contact with the layer. The invention also relates to composite parts having improved composite adhesion. Composite components comprising a carrier made of thermoplastic and at least one polyurethane layer in direct contact with the carrier are known from the prior art. For example, the coated solid molded article can be produced by a method such as RIM method (reaction injection molding). Particularly advantageous methods for producing composite components with coatings having a high layer thickness are so-called in-mold coating (IMC) or Direct Coating (DC). The coating components are applied to the respective carriers in the mold and cured in the mold cavity. In addition to the above requirements, the great advantages of IMC technology include fast processing times, low raw material losses, and one pass of production of coated injection molded parts (composite parts) comprising the coating. The composite parts obtained by the RIM process and the IMC process both have the mechanical properties of the carrier material, but their weather resistance and scratch resistance are improved by the polyurethane layer. Needless to say, the overall performance and overall stability of the composite part is also dependent on the adhesion of the polyurethane layer to the carrier. In conventional composite parts, for example comprising polycarbonate as carrier material, adhesion losses often occur after being subjected to stresses such as environmental cycling tests or storage. This also reduces the overall performance of the composite part. Another advantage of RIM or IMC methods is that specific designs are available through these methods that are not available through other methods. This is especially because the coating of the composite part can be made relatively thick while reacting quickly. DE 196 50 854 C1 discloses an IMC process for producing a multilayer plastic part, wherein a plastic injection molded part is coated with at least one layer of a two-component thermosetting material, preferably polyurethane. In this method, the plastic part and the two-component thermosetting material layer are injected successively in a cyclically synchronized manner into the same mold. The effect of the process parameters on the adhesion between the carrier material of the composite part and the layers connected thereto is not described in DE 196 50 854 C1. WO 2006/072366 A1 describes a method of forming and coating a substrate in a mould having at least two mould cavities. The method comprises the following steps: a) A substrate is formed in a first cavity of a mold, B) Introducing the substrate produced in the previous step into a second cavity of a mold, and C) The substrate is coated with a paint in a second mold cavity, wherein the coating is performed under high pressure. The focus in this document is also not the adhesion between the carrier material and the lacquer layer. EP2899008A1 describes that the adhesion to the polyurethane layer can be improved by a special surface structuring of the support. It is furthermore known that the use of primers or specific activation of the carrier material can also lead to improved adhesion. WO2011/015286 A1 relates to providing an improved composite between a support material and a polyurethane layer, provided that no modification of the support surface (in particular primer or surface activation) is required. It was found here that the use of a foamed carrier material has a positive effect on the adhesion to the polyurethane layer. The effect of the rubber content in a composition comprising polycarbonate and rubber-modified vinyl (co) polymer as carrier material on the composite adhesion was investigated in WO2011/070044 A4. PCT/EP2023/069171, which has not yet been published, achieves an improvement in the composite adhesion of composite parts by using supports or films having a specific OH group content. DE 112018006158 T5 discloses an ink for digital printing which offers a great degree of freedom of design by printing a surface. In these documents, the improvement of the composite adhesion is achieved either by additional steps, such as applying a primer, surface activation, surface structuring or foaming the carrier material, or by adding additives to the composition of the carrier material. This means that in the production of composite parts either additional steps are required which are dedicated to improving the adhesion and thus bring about a corresponding cost and complexity. Or require