Decorative part processing technology, decorative part and vehicle lamp

Abstract

The invention discloses a decorating part processing technology, a decorating part and a vehicle lamp, and the decorating part processing technology comprises the following steps: under a vacuum condition, controlling arc discharge to bombard a metal target material, and ionizing to form metal ions, arranging a bias electric field to drive the metal ions to bombard the surface of the base material and combine with preset reaction gas to form a compound film developing layer on the base material, and controlling the color and performance of the compound film developing layer through selection of the metal target material and the preset reaction gas; the matt layer is formed on the compound film color developing layer, the matt layer provides low-reflectivity optical performance and mechanical protection performance, a low-glossiness matte metal surface diffuse reflection effect is formed, light can be scattered in all directions through a special interface structure, and the soft, uniform and bright light effect is achieved when the decorating part reflects the light.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of decorative parts applied to vehicles, in particular to a decorative part processing technology, a decorative part and a vehicle lamp. BACKGROUND

[0002] With the accelerated evolution of individualization and high-endization of the automobile consumption market, the design of the automobile lighting system (covering the front light, LOGO light, grille light, tail light and interior and exterior atmosphere light) is increasingly diversified, becoming the core carrier of brand aesthetics and technological genes.

[0003] At present, the common effect of the decorative part is high-brightness metal luster, matched with direct reflection or mirror reflection optical structure.

[0004] In some implementations, the plastic surface can be electroplated with chromium, the plated metal or other insoluble material is used as an anode, and the plated workpiece is used as a cathode. Through electrochemical reaction, the cations of the plated metal are reduced to a metal plating layer on the surface of the cathode substrate, realizing high-brightness luster as an exterior trim part.

[0005] In other implementations, high-brightness metal luster effect can also be achieved on the surface of plastic or metal through vacuum thin film deposition technology, such as physical vapor deposition technology (PVD) or chemical vapor deposition technology (CVD). The process path of physical vapor deposition technology is to vaporize solid plating film material (aluminum plating, chromium plating, indium plating, etc.) into atomic or molecular state under vacuum conditions, and then deposit it on the surface of the substrate to form a metal thin film, including evaporation plating, sputtering plating (mainstream) and arc plating. By controlling the thickness of the plating layer, full reflection, semi-transmission and semi-reflection effects can be achieved. Chemical vapor deposition technology refers to a technology that introduces two or more gaseous materials into a reaction chamber, and makes them chemically react on the surface of the substrate to form a coating or nanomaterial.

[0006] In addition, the same effect can also be achieved by spraying paint on plastic or metal materials, such as high-brightness metal paint, silver powder paint, etc.

[0007] However, the existing scheme can only achieve high-brightness metal effect. The decorative part with high-brightness metal effect may cause different degrees of optical interference in actual use: 1) glare pollution, which easily affects the vision of the driver of the following vehicle; 2) interference with the laser radar sensor of surrounding vehicles. Laser radar is sensitive to high-brightness surface reflectivity, and the point cloud noise detected by the laser radar sensor increases by 50%, thereby affecting the automatic driving decision. In addition, with the maturation of high-brightness technology, the design tends to be homogenized, weakening the brand recognition. SUMMARY

[0008] The technical problem solved by the present application is to provide a decorative part processing technology, a decorative part and a vehicle lamp to solve the problem of optical interference caused by high-brightness metal effect in the existing exterior part scheme.

[0009] To solve the above problems, the technical scheme of the present application is: The present application provides a decorative part processing technology, comprising: Under vacuum conditions, arc discharge is controlled to bombard metal target material to ionize metal ions, and the metal ions are driven to bombard the surface of the substrate under the action of a bias electric field to form a compound thin film color developing layer on the substrate together with a preset reaction gas; An extinction layer is formed on the compound thin film color developing layer.

[0010] In some embodiments, after forming the extinction layer on the compound thin film color developing layer, it further comprises: controlling inert gas ions to bombard the surface of the extinction layer to form a convex structure.

[0011] In some embodiments, the surface roughness of the convex structure ranges from Ra0.4 to 0.8 μm.

[0012] In some embodiments, the substrate is an aluminum substrate.

[0013] In some embodiments, before the step of controlling arc discharge to bombard metal target material to ionize metal ions under vacuum conditions, and driving the metal ions to bombard the surface of the substrate under the action of a bias electric field to form a compound thin film color developing layer on the substrate together with a preset reaction gas, it further comprises: Pretreating the surface of the substrate to form a bonding force enhancing layer.

[0014] In some embodiments, the pretreatment is a chromium plating treatment.

[0015] In some embodiments, the voltage of the arc ranges from 15 to 40 V, and the current of the arc ranges from 50 to 200 A.

[0016] In some embodiments, the metal target material is Cr and / or Ti, and the preset reaction gas is one or more of N2, C2H2 and CH4. In some embodiments, the extinction layer is a diamond-like carbon extinction layer, and the step of forming the extinction layer on the compound thin film color developing layer comprises: introducing a gaseous precursor containing carbon gas, generating plasma by a radio frequency (RF) or direct current (DC) power source, and depositing carbon ions in the plasma onto the surface of the substrate under the action of an electric field.

[0017] In some embodiments, the gaseous precursor further comprises a silicon-containing gas.

[0018] In some embodiments, the thickness of the adhesion-enhancing layer is in the range of 0.08-0.12 μm, the thickness of the compound thin-film color layer is in the range of 0.4-0.6 μm, and the thickness of the extinction layer is in the range of 0.15-0.25 μm.

[0019] The present application provides a decorative piece comprising, in order, an adhesion-enhancing layer, a compound thin-film color layer, and an extinction layer formed on the surface of a substrate.

[0020] The present application provides a vehicle lamp comprising a decorative piece formed by the decorative piece processing method of any one of the above, or comprising the decorative piece of the above.

[0021] The present application has the following advantages and positive effects compared with the prior art due to the above technical solutions: The present application controls the ionization of metal ions by arc discharge bombardment of a metal target under vacuum conditions, and drives the aforementioned metal ions to bombard the surface of a substrate and combine with a preset reaction gas to form a compound thin-film color layer on the substrate. The color and performance of the compound thin-film color layer can be controlled by selecting the metal target and the preset reaction gas. An extinction layer is further formed on the compound thin-film color layer, which provides low reflectivity optical performance (extinction) and wear-resistant, scratch-resistant mechanical protection performance, forming a low-gloss matte metal surface diffuse reflection effect, avoiding optical interference caused by high-brightness metal effects. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A process flow chart of the decorative piece processing method of Embodiment One of the present application; Figure 2 A plated layer structure schematic diagram of the matte metal diffuse reflection feeling decorative piece formed by the decorative piece processing method of Embodiment One of the present application; Figure 3 A decorative piece structure schematic diagram of Embodiment Four of the present application; Figure 4 A decorative piece structure schematic diagram of Embodiment Five of the present application; Figure 5 A decorative piece structure schematic diagram of Embodiment Six of the present application. DETAILED DESCRIPTION

[0023] The decorative piece processing method of the present application is further described in detail below in combination with the accompanying drawings and specific embodiments. The advantages and features of the present application will be more apparent from the following description and claims.

[0024] Embodiment One Referring to Figure 1 and Figure 2 In one embodiment, a decorative piece processing method is provided, comprising the following steps: S200: Under vacuum conditions, the arc discharge is controlled to bombard the metal target to ionize and form metal ions, and the metal ions are driven to bombard the surface of the substrate 101 and form a compound thin film color layer 105 on the substrate 101 with the preset reaction gas under the action of the bias electric field. S300: An matting layer 107 is formed on the color development layer 105 of the compound thin film.

[0025] Therefore, the above-mentioned decorative part processing technology forms a compound thin film color layer 105 and a matte layer 107 on the surface of the substrate 101 so as to achieve a metallic matte effect while forming a reflection on the surface of the substrate 101.

[0026] In this embodiment, under vacuum conditions, an arc discharge is controlled to bombard a metal target, ionizing it to form metal ions. A piezoelectric field is then set to drive the aforementioned metal ions to bombard the surface of a substrate 101 and combine with a preset reactive gas to form a compound thin film color layer 105 on the substrate 101. The color and properties of the compound thin film color layer 105 can be controlled by selecting the metal target and the preset reactive gas. Furthermore, a matte layer 107 is formed on the compound thin film color layer 105. The matte layer 107 provides low reflectivity optical properties (matte) and wear-resistant and scratch-resistant mechanical protection properties, forming a low-gloss matte metal surface diffuse reflection effect.

[0027] The following is a further explanation of the specific details of the decorative part processing technology in this embodiment: In some embodiments, prior to step S200, the following may also be included: Step S100: Pre-treat the surface of the substrate 101 to form an adhesion enhancement layer 103.

[0028] In this embodiment, an adhesion enhancement layer 103 is formed by pre-treating the surface of the substrate 101 to improve the adhesion of subsequent layers to the substrate surface. Correspondingly, step S200 includes controlling an arc discharge to bombard a metal target under vacuum conditions to ionize and form metal ions, and driving the metal ions to bombard the surface of the substrate 101 with the adhesion enhancement layer 103 formed under the action of a bias electric field to form a compound thin film coloring layer on the adhesion enhancement layer 103 with a preset reactive gas.

[0029] In this embodiment, after the matting layer 107 is formed, inert gas ions can be further controlled to bombard the surface of the matting layer 107 to form a raised structure, which can then scatter the incident light to further improve the diffuse reflection effect.

[0030] In this embodiment, the substrate 101 is preferably an aluminum substrate (other metal substrates may also be used in other embodiments); the pretreatment method of the surface of the substrate 101 is preferably chrome plating (other bonding reinforcement layer 103 formation methods may also be selected in other embodiments, and are not limited to chrome plating or chrome bonding reinforcement layer).

[0031] In this embodiment, the specific parameters of the discharge arc used to form the aforementioned metal ions are as follows: the arc voltage range is 15-40V, and the arc current range is 50-200A. The metal target material is Cr and / or Ti. The preset reaction gas used to react with the metal ions to form the compound thin film color layer 105 can be one or more of N2, C2H2, and CH4.

[0032] The specific process is as follows: In a vacuum chamber, an arc-initiating device (such as an arc-initiating needle) briefly contacts a metal target (cathode) and then separates, generating a high-temperature electric arc. The arc spot moves violently on the target surface, instantly generating extremely high temperatures (up to several thousand degrees Celsius), causing the target material to rapidly evaporate and ionize, forming a highly ionized plasma cloud containing metal atoms, a high proportion of metal ions, electrons, and micron-sized droplets. Subsequently, based on the positively charged metal ions in the arc plasma, under the action of an electric field bias, the positive ions are accelerated and attracted by the negatively charged substrate, thus bombarding the substrate surface (specifically the surface of the bonding reinforcement layer 103) with very high energy. The bombardment serves two purposes: first, it transfers kinetic energy to the atoms deposited on the surface, giving them higher surface migration capabilities, filling gaps, and thus generating a dense and uniform thin film structure, reducing defects such as columnar crystals; second, the energy of the bombardment provides the necessary activation energy for the chemical reaction between metal atoms and reactive gases on the surface of the bonding reinforcement layer 103. The reactive deposition process involves introducing reactive gases, such as nitrogen (N2) to prepare nitrides (e.g., TiN, CrN, AlCrN), or acetylene (C2H2) and methane (CH4) to prepare carbides (e.g., TiC, DLC), into a vacuum chamber. On the bombarded, active bonding reinforcement layer 103, high-energy metal ions react with active reactive gas atoms (e.g., N, C) to generate a compound thin film color layer 105.

[0033] The color and properties (such as gray-black CrCN and deep gold TiN) can be controlled by adjusting the gas (e.g., N2 / C2H2) and the bias voltage. N2, as an inert gas, can also prevent oxidation, while C2H2 can act as a reactive gas in CVD coating to control the color of the coating.

[0034] In this embodiment, the matting layer 107 formed on the color development layer 105 of the compound thin film can specifically be a diamond-like carbon matting layer, which can be obtained by plasma-enhanced chemical vapor deposition.

[0035] Specifically, carbon-containing gas (such as CH4 or C2H2) is introduced, and plasma is generated by radio frequency (RF) or direct current (DC) power supply. The carbon ions in the plasma are deposited on the surface of the substrate under the action of the electric field to form a DLC film (i.e., diamond-like carbon matting layer).

[0036] Furthermore, in plasma-enhanced chemical vapor deposition, a gaseous precursor containing carbon and silicon can be introduced, which dissociates in the plasma and co-deposits onto the color development layer 105 of the compound thin film, i.e., silicon doping is added to increase light scattering (by adjusting the silicon content, the refractive index of the DLC thin film can be controlled within a certain range).

[0037] In this embodiment, the step of controlling the formation of a raised structure by bombarding the surface of the diamond-like carbon matting layer with inert gas ions may further include the selection of the inert gas ions and the surface roughness range of the raised structure. Specifically, the inert gas ions may be argon ions, and the surface roughness range of the raised structure is Ra0.4–0.8 μm.

[0038] The specific process involves argon ion bombardment of the diamond-like carbon (DLC) matte layer surface for surface reshaping and plastic deformation. The DLC matte layer not only has high hardness but also excellent toughness and load-bearing capacity, enabling it to withstand the stress from bombardment and undergo plastic flow. Due to microscopic defects, impurities (such as silicon), and lattice stress inhomogeneity on the DLC matte layer surface, the bombardment rate varies at different points, leading to selective sputtering. Some points are sputtered quickly, forming "valleys"; others are sputtered slowly or accumulate due to pressure from surrounding materials, forming "peaks." These "peaks" are formed by the redistribution of the DLC matte layer itself, resulting in the aforementioned protruding structure. Furthermore, precisely controlled argon ion bombardment only affects the outermost DLC matte layer, without damaging the underlying compound film color layer 105 (such as CrCN). The argon ion bombardment energy used for surface modification is typically controlled within a low range of 100 eV to 200 eV (electron volts). At this energy level, argon ions have a very shallow effect on the material surface, typically only a few nanometers to tens of nanometers.

[0039] In this embodiment, the thickness of the bonding enhancement layer 103 can range from 0.08 to 0.12 μm, with a preferred value of 0.1 μm; the thickness of the compound film color development layer 105 ranges from 0.4 to 0.6 μm, with a preferred value of 0.5 μm; and the thickness of the matting layer 107 ranges from 0.15 to 0.25 μm, with a preferred value of 0.2 μm.

[0040] The decorative parts obtained by the processing technology of this embodiment can achieve a matte metallic diffuse reflection effect. They can be used as decorative rings, decorative panels and other parts for headlights, logo lights, grille lights, taillights and interior and exterior ambient lights. The special interface structure can diffuse light in all directions. When the light source shines on the decorative parts, it reflects light through the decorative parts to present a soft, uniform and bright lighting effect. This can reduce optical interference caused by the reflective surface of the decorative parts and create a sense of "technology" and "ambience".

[0041] Example 2 This embodiment provides a decorative component, which specifically includes a substrate 101, a compound thin film color-developing layer 105, and a matte layer 107 formed on the surface of the compound thin film color-developing layer 105. The compound thin film color-developing layer 105 controls the overall color and properties of the decorative component, while the matte layer 107 provides low reflectivity optical properties (matte finish) and wear-resistant and scratch-resistant mechanical protection properties, thereby enabling the decorative component to achieve a matte metallic surface diffuse reflection effect.

[0042] Furthermore, this application may also include an adhesion enhancement layer 103 formed on the surface of the substrate 101, and a compound film color development layer 105 formed on the surface of the adhesion enhancement layer 103. The adhesion enhancement layer 103 is used to improve the adhesion of the compound film color development layer 105.

[0043] Furthermore, the surface of the matte layer 107 can be configured to have a raised structure, which then scatters the incident light to enhance the diffuse reflection effect of the matte metal surface.

[0044] In this embodiment, the substrate 101 may specifically be an aluminum substrate, and the bonding reinforcement layer 103 may specifically be a chromium plating layer formed on the surface of the aluminum substrate.

[0045] Furthermore, the compound thin film color layer 105 can be formed by physical vapor deposition.

[0046] Furthermore, the matting layer 107 can specifically be a diamond-like carbon matting layer, which can be obtained by plasma-enhanced chemical vapor deposition. The protruding structure on the surface of the diamond-like carbon matting layer can be formed by bombardment with inert gas ions, which can be argon ions.

[0047] In this embodiment, the thickness of the bonding enhancement layer 103 can range from 0.08 to 0.12 μm, with a preferred value of 0.1 μm; the thickness of the compound film color development layer 105 ranges from 0.4 to 0.6 μm, with a preferred value of 0.5 μm; and the thickness of the matting layer 107 ranges from 0.15 to 0.25 μm, with a preferred value of 0.2 μm.

[0048] The decorative component in this embodiment can achieve a matte metallic diffuse reflection effect. It can be used as a trim ring, trim panel and other parts in headlights, logo lights, grille lights, taillights and interior and exterior ambient lights. The special interface structure can diffuse light in all directions. When light from the light source shines on the decorative component, it is reflected by the decorative component to present a soft, uniform and bright lighting effect. This can reduce optical interference caused by the reflective surface of the decorative component and create a sense of "technology" and "ambience".

[0049] Example 3 This embodiment provides a vehicle lamp, which includes a decorative part formed by the decorative part processing technology in Embodiment 1 above, or includes a decorative part in Embodiment 2 above.

[0050] Example 4 See Figure 3 This embodiment provides another implementation method to achieve a low-gloss matte metallic effect. This implementation method can spray matte topcoat 205 onto the surface of substrate 201 (such as aluminum substrate). The process path includes: firstly, ablation of the surface of substrate 201 with short pulse (femtosecond / picosecond) laser to form a precisely controllable micro-pits, grooves or array structures 203 on the surface of substrate 201 to construct a diffuse reflection interface; then spraying matte topcoat 205, the color of which can be transparent or black, gray, etc., to create a low-gloss effect.

[0051] The steps are as follows: Step 1: Laser Etching Micrometer- or even nanometer-scale rough structures are formed on the surface of substrate 201, with scales similar to or larger than visible light wavelengths (380-780 nm). Specular reflection is completely eliminated through multiple reflections and scattering. Specifically, suitable laser wavelengths, pulse widths, repetition frequencies, average power, and single-pulse energy are selected, and the scanning speed (100 mm / s - 2000 mm / s) and scan line spacing (5 μm - 20 μm) on the aluminum substrate surface are controlled to etch a micro-pit array or rough structure 203. During processing, compressed air or nitrogen (N2) is used to blow away the processing area, promptly removing debris and plasma clouds generated by ablation, preventing them from redepositing on the surface or obstructing subsequent laser pulses, thus ensuring processing quality and efficiency.

[0052] Step 2: Apply matte topcoat Matte topcoat 205 contains a matting agent that works synergistically with the laser microstructure to further enhance scattering. Specifically, the substrate is pretreated, then sprayed to form a film, and subsequently cured (generally at high temperature, with a temperature range of 70-80℃ and a time range of 30-45 minutes).

[0053] Furthermore, a pretreatment step may be included before step one, which involves forming and curing a primer layer on the substrate 201, so that laser etching is performed on the primer without damaging the substrate.

[0054] Example 5 See Figure 4 This embodiment provides another implementation method to achieve a low-gloss matte metallic effect. This implementation method involves spraying matte metallic paint 307 onto the surface of a plastic substrate 301. Specifically, it includes: applying a primer 305 to the plastic substrate 301 to provide a certain adhesion, and then spraying matte metallic paint 307. The color can be metallic gray or metallic blackish gray, etc., and it contains aluminum powder and matting agent, which can achieve a low gloss while providing a metallic effect.

[0055] The process route is as follows: Step 1: Injection Molding During injection molding, the texture of the plastic substrate 401 is designed directly on the mold, forming a diffuse reflection surface microstructure 303 on the surface of the plastic substrate 301; Step 2: Spraying For PC (polycarbonate), PC+ABS (engineering plastic alloy), and high-temperature resistant ABS (Acrylonitrile Butadiene Styrene) substrates, matte metallic paint 307 can be sprayed directly without primer 305; for low surface energy substrates such as glass fiber reinforced PP (polypropylene) and mineral filled PP (polypropylene), a layer of primer 305 should be sprayed first to increase adhesion before spraying matte metallic paint 307. The matte metallic paint 307 is sprayed into a film and then cured (generally at high temperature, 70~80℃ / 30~45min). The matte metallic paint 307 contains a matting agent, which works synergistically with the diffuse reflection surface microstructure 303 to further enhance scattering.

[0056] Example 6 See Figure 5 This embodiment provides another method for achieving a low-gloss matte metallic effect. This method involves depositing an aluminum layer 405 on the surface of a plastic substrate 401 and then spraying a matte topcoat 407 to achieve the matte metallic effect. The aluminum layer 405 provides a metallic texture base, and the matte topcoat 407 reduces gloss, thus preserving the visual depth of the metal while controlling mirror glare. The plastic substrate 401 can be PC (polycarbonate) or PC+ABS (engineering plastic alloy).

[0057] The process route includes: Step 1: Injection Molding During injection molding, the texture of the plastic substrate 401 is designed directly on the mold, forming a diffuse reflection surface microstructure 403 on the surface of the plastic substrate 401. Step 2: Aluminum plating An aluminum layer 405 is deposited on the surface of the plastic substrate 401 using evaporation or sputtering deposition techniques. The parameters for the aluminum deposition process can be: vacuum degree 7.5–8.0 × 10⁻⁶. -3 Pa, coating time 600±20S, coating current 25±2A, coating voltage 480±20V, fixture speed 6±1 r / min; Step 3: Spraying A layer of matte topcoat 407 is sprayed onto the aluminum film. This topcoat can be transparent or gray, dark gray, or other colors. The matte topcoat 407 is sprayed into a film and then cured (generally at high temperature, 70-80℃ for 30-45 minutes). The matte topcoat 407 contains a matting agent, which works synergistically with the diffuse reflection surface microstructure 403 to further enhance scattering.

[0058] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.

Claims

1. A processing technology for decorative parts, characterized in that, include: Under vacuum conditions, an arc discharge is controlled to bombard a metal target to ionize and form metal ions. Under the action of a bias electric field, the metal ions are driven to bombard the surface of a substrate and form a compound thin film color layer on the substrate with a preset reaction gas. An matting layer is formed on the color development layer of the compound film.

2. The decorative part processing technology as described in claim 1, characterized in that, After forming the matting layer on the color-developing layer of the compound film, the method further includes: Inert gas ions are controlled to bombard the surface of the matting layer to form a raised structure.

3. The decorative part processing technology as described in claim 2, characterized in that, The surface roughness of the protrusion structure ranges from Ra0.4 to 0.8 μm.

4. The decorative part processing technology as described in claim 1, characterized in that, The substrate is an aluminum substrate.

5. The decorative part processing technology as described in claim 1, characterized in that, Before the process of controlling the arc discharge to bombard the metal target to ionize and form metal ions under vacuum conditions, and driving the metal ions to bombard the substrate surface with a preset reactive gas to form a compound thin film coloring layer on the substrate, the process further includes: Pre-treat the substrate surface to form an adhesion-enhancing layer.

6. The decorative part processing technology as described in claim 5, characterized in that, The pretreatment is chrome plating.

7. The decorative part processing technology as described in claim 1, characterized in that, The voltage range of the electric arc is 15-40V, and the current range of the electric arc is 50-200A.

8. The decorative part processing technology as described in claim 1, characterized in that, The metal target is Cr and / or Ti, and the preset reaction gas is one or more of N2, C2H2, and CH4.

9. The decorative part processing technology as described in claim 1, characterized in that, The matting layer is a diamond-like carbon matting layer, and the formation of the matting layer on the color-developing layer of the compound film includes: A gaseous precursor containing carbon gas is introduced, and plasma is generated by a radio frequency (RF) or direct current (DC) power supply. Carbon ions in the plasma are deposited onto the surface of the substrate under the action of an electric field.

10. The decorative part processing technology as described in claim 9, characterized in that, The gaseous precursor also includes silicon-containing gas.

11. The decorative part processing technology as described in claim 5, characterized in that, The thickness of the bonding enhancement layer ranges from 0.08 to 0.12 μm, the thickness of the compound film color development layer ranges from 0.4 to 0.6 μm, and the thickness of the matting layer ranges from 0.15 to 0.25 μm.

12. A decorative element, characterized in that, It includes a compound thin film coloring layer and a matting layer formed sequentially on the surface of the substrate.

13. A vehicle lighting fixture, comprising a decorative element formed by the decorative element processing technology as described in any one of claims 1 to 11, or comprising a decorative element as described in claim 12.

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