Protective trim for car interior plastic

Abstract

A protective strip for the interior plastic of a car, characterized by being made of multiple layers, wherein the first layer is a primer with an acrylic polymer; the second layer contains a solvent adhesive; the third layer is a cast polyvinyl chloride film for apolar surfaces; the fourth layer is a polyvinyl chloride film with a self-adhesive acrylic layer; the fifth layer is made of a ceramic composition.

Description

[0001] The utility model relates to the field of protecting external and internal surfaces of motor vehicles from physical and chemical impacts and wear that occur during their operation.

[0002] The prior art discloses, for example, a decorative material according to Patent No. RU 2328378 C2 dated July 10, 2008, which is obtained by laminating paper coated with a resin cured by ionizing radiation onto paper impregnated with a thermosetting resin and hot pressing. The decorative material comprises a surface layer and a base material layer laminated and located on its outer side. The surface layer comprises at least a surface polymer layer made of a cured resin material cured by ionizing radiation, a blocking layer for the permeation of uncured thermosetting resin material, and an impregnated paper layer formed by paper impregnated with a thermosetting resin and cured, laminated on the outer side. At least the uppermost surface of the base material layer comprises an impregnated paper layer formed by paper impregnated with a thermosetting resin and cured.

[0003] Also known is a multilayer film according to patent No. RU 2381104 C2 dated 10.02.2010, which can be used for the exterior and interior decoration of cars by creating a connection between a layer of polyamide molding material and a part made of acrylonitrile butadiene styrene (ABS) molding material. The adhesion promoter for the said compound comprises from 2 to 100 wt.% of a copolymer containing from 70 to 99.9 wt.% of monomer units that are derivatives of vinyl compounds selected from the group comprising acrylic acid derivatives, methacrylic acid derivatives and vinyl aromatic compound derivatives, and from 0.1 to 30 wt.% of monomer units with functional groups selected from the group comprising a carboxylic acid anhydride group, an epoxy group and an oxazoline group.A multilayer film comprises at least one layer of a polyamide molding compound and at least one layer of an adhesion promoter of the aforementioned composition, and is produced by coextrusion or lamination. A composite part consists of a part made of an ABS molding compound and a multilayer film, and is produced by injection molding, with the multilayer film being placed in a mold, coextrusion, pressing, lamination, injection, or foaming of the adhesion promoter between the multilayer film and the base.

[0004] The disadvantages of known analogues include low efficiency of protection against mechanical damage.

[0005] The objective of the claimed utility model is to eliminate the shortcomings of analogues.

[0006] The technical result is protection against mechanical damage.

[0007] The technical result is achieved due to the fact that the protective overlay for interior plastic is made of multiple layers, wherein the first layer is a primer with an acrylic polymer; the second layer contains a solvent adhesive; the third layer is a cast polyvinyl chloride film for low-energy (apolar) surfaces; the fourth layer is a vinyl film with a self-adhesive acrylic layer; the fifth layer is a ceramic composition or liquid glass or fast quartz.

[0008] Fig. 1 shows a protective cover for interior plastic.

[0009] 1 - primer with acrylic polymer;

[0010] 2 - solvent glue;

[0011] 3 - cast polyvinyl chloride film for apolar surfaces;

[0012] 4 - vinyl film with self-adhesive acrylic layer;

[0013] 5 - ceramic composition.

[0014] The stated technical solution allows for high protection against mechanical damage to vehicle surfaces due to the fact that the fifth (top) layer functions as a damper, absorbing the main energy of external influence (impact), and layers one through four perform the function of stopping penetrating impact.

[0015] Cars suffer various types of damage during use. Both exterior and interior surfaces are subject to physical and chemical damage. Currently, protection has been developed for exterior surfaces (polyurethane film) and interior surfaces (seat covers, polyurethane film for glossy interior trim). In addition to these interior elements, there are also textured plastic and elements covered with plasticized leather / regular genuine leather. Textured plastic is used to make door panels, sills, roof pillar trim, steering wheel cover, trunk trim, and trunk lid trim on the interior side. Plasticized leather and genuine leather are used to cover door panels and the dashboard. The above-described interior surfaces have one characteristic: they are low-energy (and the material from which they are made is apolar).In everyday terms, this means that these materials are poorly resistant to moisture, dirt, and other household contaminants. This means that textured plastic and plasticized leather are difficult to adhere to, making these surfaces easy to clean and maintain, with minimal dirt retention. However, car owners need to protect these surfaces from scratches and other similar damage, as these same interior elements are also design elements of the car. This is difficult to achieve, as low-energy surfaces are extremely difficult to protect. Typically, any surface protection method involves applying some kind of adhesive-backed material to the surface. The adhesive backing protects the surface from physical damage, while the adhesive layer holds the material to the surface being protected.After the car owner deems the protection to have sustained "sufficient" damage, it must be safely removed from the surface being protected. Ease of removal is a key requirement. There must be no adhesive residue or physical damage left on the surface being protected from the removal of the protective material. This means that strong (permanent) adhesives should not be used; only temporary adhesives, which allow for safe removal, can be used.

[0016] Temporary adhesives cannot be used on textured plastics and plasticized leather, as they do not adhere to low-energy surfaces. Any material with this type of adhesive will peel off from such surfaces almost immediately (or within a couple of days). An example of such an adhesive is acrylic. These adhesives are used in the manufacture of car body protection materials, where the surfaces are not low-energy. Polyurethane car body wraps and vinyl car body wraps are all protective materials that adhere easily to the car body (paint), but they cannot adhere to textured plastics and plasticized leather; they will peel off, especially if the surface being protected is curved.To process a curved surface, it is necessary to stretch the protective material, which entails a thinning of the adhesive layer and the appearance of a shrinkage effect of the stretched material, that is, its tendency to return to its original state due to its own elasticity.

[0017] The following materials are used to produce sets of protection for interior textured plastic and elements covered with plasticized leather.

[0018] The primer provides adhesion on inert power lines (polypropylene, polyethylene) not by “gluing”, but by irreversible chemical-physical modification of the surface layer, creating a new, active interface.

[0019] The key role of acrylic polymer in the primer: acrylic polymer in the primer is not just a film-forming agent, but the main structural and functional agent that performs two tasks:

[0020] 1. Formation of mechanically anchored interface through compatibility and entanglement of chains:

[0021] - The acrylic component of the primer is a specially designed copolymer (e.g. based on butyl or ethyl acrylate) whose solubility parameters (according to Hansen) are selected for limited thermodynamic compatibility with power transmission lines.

[0022] - Active primer solvents selectively plasticize and swell the surface layer of the power transmission line to a depth of tens to hundreds of nanometers, temporarily increasing the mobility of its polymer chains.

[0023] - The acrylic polymer chains from the primer diffuse into this swollen layer. After the solvents evaporate, "setting" occurs, and the primer acrylate chains physically entangle with the substrate chains, forming a strong interpenetrating network at the interface.

[0024] 2. Providing reactive groups for chemical bonding with film adhesive:

[0025] - The acrylic polymer in the primer is functionalized. Units with reactive groups, such as carboxyl (-COOH), hydroxyl (-OH), or epoxy, are introduced into its composition during the synthesis stage.

[0026] These groups perform two functions:

[0027] - Increase the surface energy of the formed interface.

[0028] - Act as sites for chemical interaction with the functional groups of the acrylate adhesive of the protective film. This interaction (formation of hydrogen bonds, possible formation of covalent bonds in the presence of, for example, isocyanate crosslinkers in the adhesive) provides strong chemical adhesion where the original plastic could not provide it.

[0029] Vinyl (polyvinyl chloride) film with a self-adhesive acrylic layer, offering a custom appearance (e.g., the Oracal 970 series or the KPMF 80000 series). These films are available in calendered or cast versions, depending on their manufacturing method. We prefer cast vinyl films, as they have the least shrinkage when stretched and applied to curved surfaces.

[0030] Cast polyvinyl chloride film for low-energy (apolar) surfaces (e.g., Orajet 3105 HT, Orajet 3106SG, Ritrama Hi-Grip 100, Ritrama Hi-Grip 75). These films are designed to protect surfaces to be covered. Their primary purpose was to protect and cover concrete walls, brickwork, polypropylene boards, foam plastic, and rubber. All these materials have a porous structure and a small surface area due to their increased porosity, meaning they require different types and applications of adhesives.

[0031] The adhesive used in these films is solvent-based and reinforced. Furthermore, these materials feature increased thickness of both the PVC layer and the adhesive layer, which is an important factor in protecting the surface being covered from physical impact. These films are also not calendered, but rather cast or polymer-based, allowing them to better adhere to curved surfaces and prevent shrinkage.

[0032] The bottom layer features a reinforced, thick solvent-based adhesive that better penetrates the texture of the protected surface and, due to its improved adhesion to porous and low-energy surfaces, ensures the protective pad adheres securely to the surface. The polyvinyl chloride (PVC) cast / polymer base of the bottom layer eliminates shrinkage when installed on curved surfaces.

[0033] Manufacturing protective pads according to the stated technical solution is technically more complex, but it yields a more reliable result, as only in this case can the service life of the protective kits be equal to the service life of the vehicle (10-12 years). With all other known state-of-the-art solutions, the service life would be significantly shorter, from two days to six months.

[0034] Brief working mechanism:

[0035] Inert power line (low energy, no active groups) - primer application

[0036] - swelling of the surface layer of the power transmission line and diffusion of the acrylic polymer chains of the primer - evaporation of solvents and formation of an anchored layer

[0037] - exposure of reactive -COOH / -OH groups of acrylate primer on a new surface - application of protective film - chemical bonding of film adhesive with primer layer groups and mechanical adhesion of primer layer to plastic - synergistic strong adhesion.

[0038] Thus, the acrylic polymer in the primer acts as a “molecular bridge”: one “end” (non-polar chain) mechanically adheres to the plastic, and the other “end” (polar functional groups) forms a chemical bond with the film adhesive, effectively solving the problem of adhesion to low-energy surfaces.

[0039] Primer (adhesion activator) is a multi-component liquid system applied locally to complex areas of the car body (ribs, curves, edges) before applying a protective polyurethane film (PPF). Its main function is topochemical surface modification to form covalent and specific physical bonds between the substrate (paint or plastic) and the adhesive layer of the film.

[0040] Adhesion Enhancement Mechanism

[0041] Adhesion is enhanced by the synergy of several mechanisms induced by the primer components:

[0042] 1. Plasticization and temporary reduction in the elastic modulus of the adhesive: active solvents selectively diffuse into the surface layer of the adhesive—an acrylic polymer. This causes its reversible swelling and a reduction in viscoelastic properties. This temporary softening allows the adhesive to more effectively intensify molecular contact, filling microroughness on the paint surface. After the solvents evaporate, the adhesive relaxes, creating a larger area of ​​true contact and, consequently, higher van der Waals forces.

[0043] 2. Chemical crosslinking at the phase boundary: the primer contains bifunctional or polyfunctional compounds (e.g., silanes with organofunctional groups). These molecules act as "molecular bridges." One end of such a molecule (e.g., an alkoxysilanol group) is capable of forming covalent bonds with hydroxyl (-OH) or carboxyl (-COOH) groups present on the paintwork surface. The other end (an organofunctional group: epoxy, vinyl, amino) chemically or physically interacts with the polymer matrix of the adhesive. Thus, a strong chemical anchor is formed at the phase boundary.

[0044] 3. Surface-active action and surface energy reduction: The primer components reduce the surface tension of the liquid, ensuring optimal wetting and spreading over the substrate, even on complex geometries. This eliminates the formation of air bubbles at the interface, which are the centers of adhesion failure.

[0045] Selective safety solvent system for paints and plastics

[0046] The safety of the primer for factory paintwork and polymer parts is ensured by careful thermodynamic and kinetic selection of solvents based on the principle of selective compatibility and limited exposure time.

[0047] Selective compatibility (solubility) principle: The primer solvent mixture is optimized for Hansen solubility parameters so that its polarity and hydrogen bonding ability are within the "safety window".

[0048] Solvent Selection Criteria

[0049] 1. The solvent system must be active enough to plasticize the adhesive and possibly cause slight surface swelling of the cleaned paintwork (to enhance adhesion).

[0050] 2. The solvent system must be insufficiently active to penetrate the cross-linked polymer network of the fully cured factory clearcoat. The cross-linking density of the topcoat (especially during high-temperature catalytic drying at the factory) is orders of magnitude higher than that of the adhesive layer on the film. The system is selected so that its solubility parameters do not coincide with those of the paintwork matrix, preventing its degradation.

[0051] 3. The system must be inert to the main types of automotive plastics (polypropylene, ABS, polycarbonate).

[0052] Accounting for the evaporation time of solvents

[0053] 1. The formula includes fast and slow solvents. The fast solvent (e.g., acetone, ethyl acetate) ensures immediate wetting and plasticization. The slow solvent (e.g., an aromatic hydrocarbon with a high boiling point, ketones such as methyl ethyl ketone in a controlled concentration) provides the necessary "open time" for chemical processes. However, the overall evaporation time of the entire system is strictly controlled (usually 30-180 seconds), preventing prolonged contact of the active components with the paintwork and their deep diffusion.

[0054] 2. Absence of aggressive protolytic agents: High-quality primers do not contain strong acids, alkalis, or oxidizing agents capable of hydrolyzing or oxidatively breaking down the chemical bonds in the paintwork. Any acidity / basicity is a consequence of the presence of silanes and is strictly controlled.

[0055] Thus, the primer's action is based on controlled physical plasticization, chemical crosslinking, and increased contact area. Safety is ensured by a precise balance of solubility, evaporation kinetics, and the absence of destructive agents, allowing surface modification for adhesion without compromising the integrity of the highly crosslinked factory paint or polymer substrate.

[0056] The finished set of linings consists of several similarly manufactured parts that have a different shape from each other, repeating the shape of the internal and external spaces of the car and, being installed in the required places in the car, are held on them due to the adhesive layer.

Claims

This utility model relates to the protection of the exterior and interior surfaces of motor vehicles from physical and chemical impacts and wear that occur during operation. A protective trim for interior plastic is distinguished by its multilayer construction, the first layer being a primer with an acrylic polymer; the second layer containing a solvent-based adhesive; the third layer being a cast polyvinyl chloride film for apolar surfaces; the fourth layer being a vinyl film with a self-adhesive acrylic layer; and the fifth layer being a ceramic compound. This provides protection against mechanical damage.

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