Decorative film based on micro-nano structure, laser holographic veneer and preparation method of laser holographic veneer

Abstract

The invention belongs to the technical field of decorative films, and discloses a decorative film based on a micro-nano structure, a laser holographic veneer and a preparation method of the laser holographic veneer. The preparation method of the decorative film comprises the following steps: S1, taking a base film, performing corona treatment, and coating one side of the base film with a release coating to prepare a pre-coated base film with a release layer; the release coating comprises an acrylate copolymer emulsion, water and alcohol; s2, after the release layer pre-coated with the base film is coated with UV gloss oil, mold pressing is conducted through a mold pressing mother set, then ultraviolet curing is conducted, and a holographic pattern layer of a micro-nano structure is formed; s3, coating a film on the holographic pattern layer to form a transparent medium layer; and printing to obtain the decorative film. According to the invention, laser holographic nanoimprint is combined with a printing process, so that the decorative film is endowed with a rich visual effect; and meanwhile, plastic removal of the veneer in the later period is achieved in a transferring mode, and the purpose of environment-friendly plastic reduction is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of decorative films, and in particular relates to a decorative film based on a micro-nano structure, a laser holographic decorative panel and a preparation method thereof. Background Art

[0002] Finishing material is an important material widely used in the surface decoration of boards. It has unique functions. It can not only carry a variety of colorful colors and exquisite patterns, making all kinds of boards show extremely rich and amazing visual effects, but also protect the boards to a certain extent. It is widely used in many fields such as home decoration, building materials, and automobile decoration.

[0003] The common decorative films on the market today are generally produced by printing PVC white films with embossing rollers and printing rollers. There are two main types of patterns and color effects formed by this printing method, one is monochrome printing, and the other is natural texture printing, such as wood grain, stone grain, etc. With the rapid development of the panel furniture industry and the field of automotive decoration, the demand for decorative films has also increased significantly. At the same time, people have put forward higher requirements for decorative films in terms of design and manufacturing processes. On the one hand, the surface effects brought by traditional monochrome and natural texture printing can no longer fully meet the increasingly diversified and personalized needs of customers; on the other hand, plastic films will inevitably cause certain impacts and pressures on the environment during the production process and subsequent use.

[0004] Therefore, there is an urgent need to provide a decorative film that has rich visual effects and is environmentally friendly and plastic-reducing. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a decorative film based on micro-nano structure, a laser holographic decorative panel and a preparation method thereof. The decorative film provided by the present invention has rich visual effects and is environmentally friendly and plastic-reducing.

[0006] The invention provides a method for preparing a decorative film based on a micro-nano structure.

[0007] Specifically, a method for preparing a decorative film based on a micro-nano structure comprises the following steps:

[0008] S1, taking a base film, applying a release coating on one side of the base film after corona treatment to obtain a pre-coated base film with a release layer; the release coating comprises an acrylate copolymer emulsion, water and alcohol;

[0009] S2, coating the release layer of the pre-coated base film with UV varnish, using a molding master for molding, and then UV curing to form a holographic pattern layer with a micro-nano structure;

[0010] S3, coating the holographic pattern layer to form a transparent medium layer; and then printing on the transparent medium layer to obtain a printed layer, thereby preparing a decorative film based on a micro-nano structure.

[0011] Preferably, the base film is a PET base film, and the thickness of the base film is preferably 15-23 μm.

[0012] Preferably, the coating process is performed using a mesh roller with a mesh number of 150-250. Preferably, the release coating comprises 55-65 parts of acrylate copolymer emulsion, 35-45 parts of water, 1.5-4.5 parts of ethanol, and 0.5-2.0 parts of an auxiliary agent by weight. The acrylate transfer coating is applied to the surface of the base film and can be easily and completely peeled off from the base film layer after drying, thereby achieving the de-filming of the decorative film.

[0013] Preferably, the acrylic copolymer emulsion is a methyl methacrylate copolymer emulsion. The present invention can adjust the peelability of the coating after film formation by controlling the ratio of methyl methacrylate MMA in the acrylic copolymer emulsion. Methyl methacrylate can also improve the temperature resistance of the coating due to its high glass transition temperature, and avoid the phenomenon of coating sticking to the plate caused by temperature increase caused by UV irradiation in subsequent UV molding.

[0014] Preferably, the auxiliary agent includes at least one of a film-forming auxiliary agent, a defoaming agent, and a leveling agent. The film-forming auxiliary agent includes one or more of alcohol ester dodecahydrate, DPNB, DBE-IB, and PPH. The defoaming agent includes one or more of Wacker 855E, TEGO Airex901W, HY-902W, and dapro df 7005. The leveling agent includes one or more of BYK-333, DC57, DAPRODF7015, DAPRO DF7073, and LA-743.

[0015] Preferably, the process of coating the UV varnish is: gravure coating is adopted, and the thickness of the UV varnish layer obtained by coating is controlled to be 3-10 μm.

[0016] Preferably, the UV varnish is ultraviolet curing varnish, and more preferably free radical curing UV varnish, which can quickly cure to complete the image and text transfer.

[0017] Preferably, the free radical curing UV varnish comprises a prepolymer, an active monomer, a photoinitiator and an auxiliary agent in parts by weight. Further preferably, the free radical curing UV varnish comprises 35-55 parts of a prepolymer, 35-40 parts of an active monomer, 3-5 parts of a photoinitiator and 0.5-1 parts of an auxiliary agent in parts by weight. During the free radical curing process, after the photoinitiator absorbs the radiation energy of ultraviolet rays, it will split and generate free radicals. These free radicals will then trigger the polymerization, crosslinking or grafting reaction of the unsaturated bonds in the prepolymer, thereby completing the curing in a very short time.

[0018] Preferably, the prepolymer is selected from one or more of epoxy acrylate resin, polyurethane acrylate resin, polyester acrylate resin, polyether acrylate resin, and unsaturated polyester resin. The active monomer is an acrylate monomer, and one or more of hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate can be selected. The photoinitiator includes one or more of the brands BP, TPO, 907, ITX, 184, and MBF. The auxiliary agent includes a stabilizer, a leveling agent, etc. The stabilizer is mainly used to reduce the thermal polymerization reaction that may exist during the storage process to improve the storage stability of the varnish, and one or more of hydroquinone, p-methoxyphenol, p-benzoquinone, and 2,6-di-tert-butylcresol can be selected. The leveling agent includes one or more of DC57, TEGO Rad 2100, and BYK-UV3505.

[0019] Preferably, the preparation process of the embossing master includes file design, photolithography, plate imposition, plate mounting and other processes, and the designed texture information is transferred to the metal plate roller to obtain the embossing master.

[0020] Preferably, the transparent medium layer comprises silicon oxide, metal oxide or fluoride; more preferably zinc sulfide.

[0021] The invention also provides a decorative film based on the micro-nano structure.

[0022] Specifically, a decorative film based on a micro-nano structure is prepared by the above-mentioned preparation method, and comprises, from bottom to top, a base film layer, a release layer, a holographic pattern layer, a transparent medium layer and a printing layer.

[0023] The invention also provides a method for preparing the laser holographic decorative panel.

[0024] Specifically, a method for preparing a laser holographic decorative panel comprises the following steps:

[0025] The adhesive is coated on one side of the substrate to form an adhesive layer, and then the printed layer of the decorative film is aligned with the adhesive layer for bonding; then the base film layer of the decorative film is peeled off to expose the release layer, and a protective layer is coated on the release layer to obtain a laser holographic decorative panel.

[0026] Preferably, the adhesive is a polyurethane hot melt adhesive, which comprises a main resin polyurethane, a tackifier and an auxiliary agent, and has good bonding adaptability to both wooden substrates and decorative films.

[0027] Preferably, the protective layer is a transparent protective layer. The protective layer can be made of polyurethane and / or epoxy resin. Coating a transparent protective layer on the surface of the release layer can enhance its wear resistance and weather resistance.

[0028] The invention also provides a laser holographic decorative panel.

[0029] Specifically, a laser holographic decorative panel is prepared by the above-mentioned preparation method, and comprises, from bottom to top, a wooden substrate, an adhesive layer, a printing layer, a transparent medium layer, a holographic pattern layer, a release layer and a protective layer.

[0030] One of the existing decorative films is that the base film and the release layer have poor bonding strength. If the molding process of the present invention is used to prepare a holographic pattern with a micro-nano structure, the release layer will partially or completely stick to the plate during the molding process; the other is that the release layer has good bonding strength with the base film and the molded varnish, so it is difficult to easily remove the film when preparing the laser holographic decorative panel. The present invention, through the design of the release coating, uses acrylic copolymer emulsion, water and alcohol as the main raw materials of the coating, which not only has the advantages of good flexibility, high gloss, and strong offset printing adaptability, but also can adjust the peelability of the coating after film formation, and can avoid the phenomenon of the coating sticking to the plate due to the temperature increase caused by UV irradiation in the subsequent UV molding.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The decorative film based on micro-nano structure prepared by the present invention first coats the surface of the base film with a release layer after corona treatment and dries it; then coats it with UV varnish, and uses ultraviolet radiation to cure it during the molding process, thereby realizing the transfer of the pattern; then coats it with a transparent medium layer to enhance the optical performance of the holographic pattern and ensure the integrity of the microstructure during subsequent printing; finally, prints are performed on the surface of the transparent medium layer to add color elements to enrich the appearance of the decorative film. The present invention combines color with laser holography and adopts laser holographic nanoimprinting combined with printing technology to give the new decorative film a rich visual effect, and at the same time realizes the deplasticization process of the later decorative panel by transfer, so as to achieve the purpose of environmental protection and plastic reduction.

[0033] (2) The decorative film based on micro-nano structure provided by the present invention realizes the perfect combination of color and laser holography, and laser holography technology brings a new dimension to color. It uses the interference and diffraction principles of lasers to form extremely fine and complex holographic patterns and textures on the decorative film. When these holographic patterns are superimposed on the carefully formulated colors (printing layers), the decorative effect becomes more unique, gorgeous and layered, greatly enhancing the visual appeal and impact, so that it can be widely used in various fields, bringing new breakthroughs and innovations to the decoration and beautification of products. Furthermore, the present invention utilizes a seamless molding process to achieve the complete presentation of large-format graphics, making the overall decorative effect more coherent and avoiding the imperfections and visual interference caused by splicing gaps. Secondly, the film removal process of the present invention is simple and environmentally friendly, which can not only effectively reduce the use and residue of harmful substances such as plastics, but also is very friendly to the environment and effectively implements the concept of environmental protection; it also brings great convenience and sustainability to subsequent processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The process flow chart of preparing the decorative film based on micro-nano structure and the laser holographic decorative panel for Examples 1 and 2;

[0035] Figure 2 A schematic diagram of the structure of a micro-nanostructured decorative film prepared in Example 1;

[0036] Figure 3 This is a schematic diagram of the structure of the laser holographic decorative panel prepared in Example 2;

[0037] Figure 4 This is the appearance of the laser holographic decorative panel prepared in Example 2;

[0038] Description of Figure Numbers:

[0039] Base film layer 100 , release layer 200 , holographic pattern layer 300 , dielectric layer 400 , printing layer 500 , adhesive layer 600 , wooden substrate 700 , and protective layer 800 . DETAILED DESCRIPTION

[0040] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0041] It should be noted that, in the description of the present invention, if there is a description of orientation, such as the orientation or position relationship indicated by the upper, lower, front, rear, left, right, etc., it is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and cannot be understood as a limitation of the present invention. In addition, the raw materials, reagents or devices used in the following examples, unless otherwise specified, can be obtained from conventional commercial channels, or can be obtained by existing known methods.

[0042] Example 1

[0043] A decorative film based on micro-nano structures, such as Figure 2 As shown, from bottom to top, it includes a base film layer 100, a release layer 200, a holographic pattern layer 300, a transparent medium layer 400 and a printing layer 500.

[0044] See also Figure 1 , a method for preparing a decorative film based on a micro-nano structure, comprising the following steps:

[0045] (1) In the file design stage, professional graphic design software is used to cleverly arrange the layout of lines, patterns and shapes to achieve specific optical effects, such as three-dimensional effect, dynamic effect, color change, etc.; then, the designed file information is accurately transferred to the photolithography glass using photolithography equipment, and various parameters such as photolithography exposure time and light intensity are strictly controlled to form a clear and accurate pattern on the photolithography glass; then the large plate is spliced, and the same or different local photolithography texture units are spliced ​​through UV replication to obtain a laser holographic texture resin plate; finally, it is transferred to the metal plate roller through nano-imprinting to form a molded master.

[0046] (2) A PET base film with a thickness of 23 μm is selected as a carrier of the decorative film. After corona treatment, the base film is coated by a mesh roller with a mesh size of 180. The release coating is evenly coated on the surface of the base film layer 100 on the coating equipment, and then rolled up after oven drying to obtain a pre-coated base film with a release layer 200. The release coating is composed of the following components by weight: 60 parts of methyl methacrylate copolymer emulsion, 36 parts of water, 3 parts of ethanol, and additives (0.4 parts of alcohol twelve, 0.3 parts of BYK-333, and 0.3 parts of HY-902W).

[0047] (3) After coating the release layer 200 of the pre-coated base film with UV varnish (ultraviolet curing varnish), the release layer 200 is sent to the working area of ​​the UV molding machine, and UV molding is performed using a molding master (UV plate). Under the pressure of the molding machine, the micro-nano structure on the surface of the plate roller is imprinted on the release layer 200 to form the required holographic pattern and texture; at the same time, ultraviolet irradiation is used for curing to form a holographic pattern layer 300 having a micro-nano structure and corresponding to the master pattern. In parts by weight, the UV varnish is composed of the following components: 55 parts of prepolymer polyurethane acrylate, 40 parts of acrylic monomer, 4.5 parts of 184 photoinitiator, 0.3 parts of stabilizer p-methoxyphenol and 0.2 parts of leveling agent DC57.

[0048] (4) The molded film roll is placed in a vacuum coating machine, and then the vacuum system is started to draw to the required vacuum degree, and then the zinc sulfide is evaporated by heating the evaporation boat, and the vapor is deposited on the holographic pattern layer 300 to form a zinc sulfide coating layer, thereby obtaining a transparent medium layer 400. A transparent medium layer 400 is coated on the surface of the molded holographic pattern layer 300 to enhance the optical performance of the holographic pattern and ensure the integrity of the microstructure during subsequent printing.

[0049] (5) The ink is transferred to the dielectric layer 400 according to the design pattern by a printing machine, and single-color printing or multiple-color printing can be performed to obtain a printed layer 500, thereby obtaining a decorative film based on a micro-nano structure. Printing is performed on the surface of the transparent dielectric layer 400 to add color elements to enrich the appearance of the decorative film.

[0050] Example 2

[0051] A laser holographic decorative panel, such as Figure 3 As shown, from bottom to top, it includes a wooden substrate 700, an adhesive layer 600, a printing layer 500, a transparent medium layer 400, a holographic pattern layer 300, a release layer 200 and a protective layer 800.

[0052] See also Figure 1 , a method for preparing a laser holographic decorative panel, comprising the following steps:

[0053] (1) Gluing treatment: The decorative film prepared in Example 1 is laminated with the wooden substrate 700 using an adhesive on a laminating device. The specific process is as follows: prepare the wooden substrate 700 to be glued, ensure that the surface is clean, flat and free of oil stains, and evenly apply polyurethane hot melt glue (adhesive) on the gluing surface of the wooden substrate 700 to form an adhesive layer 600; then align the printed layer 500 of the decorative film with the adhesive layer 600, align and fit them, and apply appropriate pressure to ensure that the gluing is tight without bubbles and wrinkles, until the glue is completely cured.

[0054] (2) Coating treatment: The base film layer 100 on the surface of the decorative film is peeled off and removed, and a wear-resistant coating with excellent wear resistance is selected. The coating can be applied by brushing, spraying, etc. to ensure uniform coverage of the coating to obtain a protective layer 800. Multiple layers of coating can be applied according to the coating requirements, and each layer must be properly dried.

[0055] (3) Cutting and edge banding: Cut the prepared laser holographic decorative panel according to the designed size and prepare the edge banding strip. The width of the edge banding strip should match the thickness of the laser holographic decorative panel. Use an edge banding machine or hand tools to stick the edge banding strip around the laser holographic decorative panel so that it fits tightly with the edge of the laser holographic decorative panel without warping, and obtain the laser holographic decorative panel.

[0056] Figure 4 This is the appearance of the laser holographic decorative panel prepared in this embodiment, where Figure 4 B is Figure 4 A partial enlarged view of the middle A. Figure 4 It can be seen that the laser holographic decorative panel achieves a perfect combination of color and laser holography, and its decorative effect is unique, gorgeous and layered.

[0057] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a decorative film based on a micro-nano structure, characterized in that: The following steps are involved: S1, taking a base film, applying a release coating on one side of the base film after corona treatment to obtain a pre-coated base film with a release layer; the release coating comprises an acrylate copolymer emulsion, water and alcohol; S2, coating the release layer of the pre-coated base film with UV varnish, using a molding master for molding, and then UV curing to form a holographic pattern layer with a micro-nano structure; S3, coating the holographic pattern layer to form a transparent medium layer; and then printing on the transparent medium layer to obtain a printed layer, thereby preparing a decorative film based on a micro-nano structure.

2. The preparation method according to claim 1, characterized in that: The base film is a PET base film, and the thickness of the base film is preferably 15-23 μm.

3. The preparation method according to claim 1 or 2, characterized in that: In parts by weight, the release coating comprises 55-65 parts of acrylic copolymer emulsion, 35-45 parts of water, 1.5-4.5 parts of ethanol, and 0.5-2.0 parts of an auxiliary agent.

4. The preparation method according to claim 1 or 2, characterized in that: The process of coating the UV varnish is: adopting gravure coating, and controlling the thickness of the UV varnish layer obtained by coating to be 3-10 μm.

5. The preparation method according to claim 1 or 2, characterized in that: The preparation process of the molded master includes file design, photolithography, plate imposition, plate mounting and other processes, and the designed texture information is transferred to the metal plate roller to obtain the molded master.

6. The preparation method according to claim 1, characterized in that: The transparent medium layer includes silicon oxide, metal oxide or fluoride.

7. A decorative film based on micro-nano structure, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 6, and comprises, from bottom to top, a base film layer, a release layer, a holographic pattern layer, a transparent medium layer and a printing layer.

8. A method for preparing a laser holographic decorative panel, characterized in that: The following steps are involved: The adhesive is coated on one side of the substrate to form an adhesive layer, and then the printed layer of the decorative film according to claim 7 is aligned with the adhesive layer for bonding; then the base film layer of the decorative film is peeled off to expose the release layer, and a protective layer is coated on the release layer to obtain a laser holographic decorative panel.

9. The preparation method according to claim 8, characterized in that: The adhesive is polyurethane hot melt adhesive.

10. A laser holographic decorative panel, characterized in that: The invention is prepared by the preparation method according to claim 8 or 9, and comprises, from bottom to top, a wooden substrate, an adhesive layer, a printing layer, a transparent medium layer, a holographic pattern layer, a release layer and a protective layer.

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