Preparation method of decorative plastic solvent-free film

Abstract

The invention relates to the technical field of synthetic leather membrane materials, in particular to a preparation method of a decorative plastic solvent-free membrane. The solvent-free film sequentially comprises a polyether type embossing surface layer, a polyester type thermosetting middle layer and a polyether type solvent-free bottom layer, and the preparation method comprises the following steps: S1, preparing a surface layer: mixing polyether type resin, color paste and an auxiliary agent according to a ratio, blade-coating release paper with the color paste by using a D-type blade coating knife, and performing gradient drying to prepare a surface layer film material; s2, preparing a middle layer: mixing waterborne polyester resin, a pigment and an auxiliary agent according to a ratio, blade-coating a color paste on the surface layer membrane material by using a D-shaped knife, and combining the surface layer membrane material and the middle layer membrane material into a whole through gradient drying; s3, a bottom layer is prepared, wherein polyether polyurethane, isocyanate-terminated polyurethane prepolymer and a proper amount of a catalyst are mixed; the decorative plastic solvent-free film has the embossing performance, and the plasticity and applicability of the solvent-free film are improved.

Description

Technical Field

[0001] The invention relates to the technical field of synthetic leather film materials, and in particular to a method for preparing a decorative plastic solvent-free film. Background Art

[0002] With the improvement of ecological and environmental awareness, the traditional synthetic leather industry is facing tremendous transformation pressure. The traditional synthetic leather preparation process usually requires a base fabric as a carrier, which not only limits the applicability of the product in the composite field, but also produces a large amount of volatile organic compounds (VOCs) during the production process, which has an adverse effect on the environment and human health. Although there are some solvent-free film products on the market, most of them are PVC films, which have obvious deficiencies in embossing performance and physical properties, and it is difficult to meet the increasing demand of consumers.

[0003] In view of the above problems, it is urgent to develop a new solvent-free film preparation method, which not only ensures that the product has excellent embossing performance, but also takes into account environmental protection and practicality. Summary of the invention

[0004] The object of the present invention is to provide a decorative plastic solvent-free film to solve the defects of synthetic leather film materials in the prior art, such as high VOCs content, poor embossing performance and insufficient applicability.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A method for preparing a decorative plastic solvent-free film, the solvent-free film sequentially comprising a polyether embossable surface layer, a polyester thermosetting middle layer and a polyether solvent-free bottom layer, the method comprising the following steps:

[0007] S1. Prepare the surface layer: mix the polyether resin, color paste and additives according to the ratio, control the viscosity of the surface paste to 4500-5500cps, use a D-type scraper to scrape the color paste onto the release paper, and dry it at 70℃ / 80℃ / 90℃ / 125℃ gradient to make the surface film material;

[0008] S2. Preparation of the middle layer: Mix the water-based polyester resin, colorant and additives according to the proportion, control the viscosity to 4000-6000cps, use a D-type knife to scrape the color paste onto the surface film material, and dry it at 80℃ / 90℃ / 115℃ / 130℃ gradient to combine the surface film material with the middle film material;

[0009] S3, preparing the bottom layer: mixing polyether polyurethane, isocyanate-terminated polyurethane prepolymer and an appropriate amount of catalyst; uniformly stirring the polyether polyurethane and isocyanate-terminated polyurethane prepolymer in a weight ratio of 100:50-100, applying the materials on the middle layer through a coating head, and controlling the material mixing time to not exceed 40 seconds;

[0010] The obtained bottom layer material is dried in a gradient oven at 110°C / 115°C / 120°C / 120°C / 120°C / 130°C / 130°C, and a polyimide (PI) release film is attached to the slurry when it is in a relatively dry state to obtain a product.

[0011] The decorative plastic solvent-free film of the present invention has embossable properties, and adopts a multi-layer structure design and carrier selection to improve the plasticity and applicability of the solvent-free film. The materials and functions of each layer of the present invention are as follows: Surface layer: polyether resin is used to provide the product with better wear resistance and flexibility, so that the product surface has better embossing performance. Middle layer: water-based polyester resin is used to improve the thermosetting property of the product, make the overall structure of the product more stable, and improve the embossing performance of the product. Bottom layer: polyether resin is selected, and the hydrogen bonds formed by the ether bonds and hydroxyl groups in the material better improve the cohesion and tensile strength of the material, and better improve the stability and durability of the bottom layer of the product. Carrier: PI (polyimide) release film has excellent heat resistance. It is used as a carrier of polyurethane film to provide guarantee for transferring film materials from release paper and pressing patterns.

[0012] Preferably, the method further comprises S4, post-processing: the post-processing comprises printing and embossing the surface of the film material and separating the film material, wherein:

[0013] The embossing process is: preheat the solvent-free film attached to the PI release film at 160-180℃ to soften the surface of the film, and then emboss it through a cold pressing device. The embossing speed is controlled at 10-15m / min.

[0014] Membrane material separation is: the membrane material and PI release film are separated by a separator, the speed of the separator is controlled at 8-10m / min, and the tension is controlled within 50N.

[0015] Preferably, the printing process is: using polycarbonate printing material, printing the surface of the film material through a 100-mesh roller, with a coating amount of 20g, to protect the surface condition of the product during embossing and reduce the damage to the embossing roller pattern caused by the shedding of the surface material.

[0016] Preferably, the surface layer formula includes: 100 parts of water-based polyether polyurethane resin (solid content 30% ± 5%), several parts of water-based color paste, 3-5 parts of slip agent, 0.1-0.5 parts of defoamer, 0.8-1.2 parts of leveling agent and 1-2 parts of cross-linking agent, and the coating amount is 180-250g / m 2 ;

[0017] The intermediate layer formula includes: 100 parts of water-based polyester resin (solid content 30% ± 5%), several parts of water-based colorant, 0.1-0.5 parts of defoamer, 0.8-1.2 parts of leveling agent, and the coating amount is 180-250g / m 2 ;

[0018] The bottom layer formula includes: 100 parts of polyether polyurethane, 50-100 parts of isocyanate-terminated polyurethane prepolymer, 0.3-0.6 parts of dibutyltin dilaurate, 0.3-0.6 parts of bismuth isooctanoate, and the coating amount is 200-300g / m 2 .

[0019] Preferably, the surface layer uses polytetramethylene glycol with a molecular weight of not less than 2000 as a soft segment and ethylene glycol as a hard segment to form a full polyether surface layer to ensure that the product has good embossing performance and use performance.

[0020] Preferably, the intermediate layer is made of polyester diol with a molecular weight of 2000 made from adipic acid and ethylene glycol, which is used to enhance the thermosetting properties and physical properties of the product.

[0021] Preferably, the surface layer is dried at 60-130°C for 45-75s; the middle layer is dried at 70-140°C for 60-90s; the bottom layer is dried at 100-140°C for 120-180s; the embossing is preheated at 150-190°C for 10-20s; and the bottom layer material is mixed for 30-40s.

[0022] A decorative plastic solvent-free film prepared according to the preparation method of the present invention.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The present invention adopts a completely solvent-free process, with extremely low VOCs content, has significant environmental advantages, and the product is highly safe to use;

[0025] 2. Through the multi-layer structure design of the surface layer, the middle layer and the bottom layer, excellent embossing performance and physical properties are achieved. The polyether surface layer provides the embossing basis; the polyester middle layer provides thermosetting properties, connecting the surface layer and the bottom layer of the product, making the overall structure of the product more stable; the polyether bottom layer provides applicability and durability, making it easy to attach the product to other appliances, broadening the product's application area;

[0026] 3. The product thickness is ≤0.5mm, with ultra-thin and high wear-resistant characteristics. At the same time, the unique cold pressing embossing process can give the product a rich decorative effect;

[0027] 4. Through special formula design and process control, the excellent physical properties of the product are ensured. After testing, the plastic solvent-free film for decoration of the present invention meets the following test indicators: room temperature folding resistance ≥ 50,000 times, tearing load

[0028] ≥10N, Martindale wear resistance ≥25600 revolutions, bursting strength ≥15Kg / cm 2 , tensile load ≥20N / 3cm.

[0029] The decorative plastic solvent-free film of the present invention is suitable for surface decoration of furniture, equipment and other articles. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the decorative plastic solvent-free film of the present invention, wherein 1 is a polyether embossable surface layer, 2 is a polyester thermosetting middle layer, and 3 is a polyether solvent-free bottom layer. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0032] In the present invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0033] Unless otherwise specified, the reagents used in the following examples can be purchased from conventional biochemical reagent stores.

[0034] The reagents used in the present invention can all be replaced by conventional commercially available materials.

[0035]

[0036]

[0037] The embodiment of the present invention discloses a method for preparing a decorative plastic solvent-free film, which achieves excellent embossing effect and physical properties through multi-layer structure design and specific process parameter control.

[0038] Example 1

[0039] A decorative plastic solvent-free film, the solvent-free film sequentially comprises a polyether embossable surface layer 1, a polyester thermosetting middle layer 2 and a polyether solvent-free bottom layer 3 three-layer structure, such as Figure 1 As shown, the method for preparing the decorative plastic solvent-free film is as follows:

[0040] 1. Preparation of surface layer: Mix 100 parts of water-based polyether polyurethane resin (solid content 30%), 10 parts of water-based color paste, 3 parts of slip agent, 0.1 parts of defoamer, 0.8 parts of leveling agent and 1 part of cross-linking agent, control the viscosity of the surface paste to 5000cps, use a D-type scraper to scrape the color paste onto the release paper, and the coating amount is 200g / m 2 , and dried at 70℃ / 80℃ / 90℃ / 125℃ gradient for 60 seconds to make the surface membrane material.

[0041] 2. Preparation of the middle layer: Mix 100 parts of water-based polyester resin (30% solid content), 8 parts of water-based colorant, 0.1 parts of defoamer, and 0.8 parts of leveling agent, control the viscosity to 5000cps, and use a D-type knife to scrape the color paste onto the surface film material, with a coating amount of 200g / m 2 , through 80℃ / 90℃ / 115℃ / 130℃ gradient drying for 75 seconds, the surface layer membrane material and the middle layer membrane material are combined into one.

[0042] 3. Preparation of the bottom layer: Mix 100 parts of polyether polyurethane, 50 parts of isocyanate-terminated polyurethane prepolymer, 0.3 parts of dibutyltin dilaurate, and 0.3 parts of bismuth isooctanoate, control the material temperature to 45°C, and apply it on the middle layer through a coating head, with a coating amount of 250g / m 2 The material mixing time is controlled at about 35 seconds, and the slurry is dried in a gradient oven at 110°C / 115°C / 120°C / 120°C / 120°C / 130°C / 130°C for 160 seconds. When the slurry is in a relatively dry state, a polyimide (PI) release film is attached to obtain a product.

[0043] 4. Printing process: Use 3956 polycarbonate printing material, print through a 100-mesh roller, and apply 20 g.

[0044] 5. Embossing treatment: preheat the film at 170℃ for 15 seconds, and the embossing speed is 12m / min.

[0045] 6. Film separation: The separation machine speed is 9m / min, the tension is 40N, and the embossed decorated product is obtained.

[0046] Example 2

[0047] It is basically the same as Example 1, except that:

[0048] 1. The surface coating amount is adjusted to 180g / m 2 ;

[0049] 2. The coating amount of the middle layer is adjusted to 180g / m 2 ;

[0050] 3. The bottom coating amount is adjusted to 200g / m 2 ;

[0051] 4. The preheating temperature for embossing treatment was adjusted to 160°C.

[0052] Example 3

[0053] It is basically the same as Example 1, except that:

[0054] 1. The surface coating amount is adjusted to 250g / m 2 ;

[0055] 2. The coating amount of the middle layer is adjusted to 250g / m 2 ;

[0056] 3. The bottom coating amount is adjusted to 300g / m 2 ;

[0057] 4. The preheating temperature for embossing treatment was adjusted to 180°C.

[0058] Comparative Example 1

[0059] No multi-layer structure design was adopted, and only a single layer of polyether resin was used to prepare the membrane material. Other process parameters were the same as those in Example 1.

[0060] Comparative Example 2

[0061] A double-layer structure (surface layer + bottom layer) is adopted, the middle layer is omitted, and other process parameters are the same as those in Example 1.

[0062] Comparative Example 3

[0063] Basically the same as Example 1, but without the printing process step.

[0064] Performance test: The decorative plastic solvent-free films prepared in the above embodiments and comparative examples were subjected to performance tests. The test results are shown in Table 1.

[0065] Table 1: Comparison of physical properties test results

[0066]

[0067]

[0068] Table 2: Comparison of VOCs emission test results (unit: mg / m 3 )

[0069] Testing time Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 1 day 0.08 0.07 0.09 0.25 0.18 0.08 3 days 0.05 0.04 0.06 0.20 0.15 0.05 7 days 0.02 0.02 0.03 0.15 0.10 0.02

[0070] From the test results we can see that:

[0071] 1. The decorative plastic solvent-free films prepared in Examples 1-3 have excellent physical properties, the folding times at room temperature are all more than 50,000 times, the tearing load is all more than 10N, the Martindale abrasion resistance is all more than 25,000 revolutions, and the embossing effect is good;

[0072] 2. Comparative Example 1 has only a single-layer structure, so its physical properties are obviously insufficient, especially its folding resistance and wear resistance are significantly lower than those of the embodiment;

[0073] 3. Although Comparative Example 2 adopts a double-layer structure, due to the lack of transition effect of the middle layer, the surface layer and the bottom layer are not firmly bonded, and various physical properties are lower than those of the embodiment;

[0074] 4. Comparative Example 3 has poor embossing effect due to the lack of printing treatment, and the surface material is prone to fall off during actual use;

[0075] 5. In terms of VOCs emission, Examples 1-3 and Comparative Example 3 all exhibited extremely low emission levels, while Comparative Examples 1 and 2 had relatively high VOCs emission levels.

[0076] Through the analysis of the above test results, it can be seen that the preparation method of the decorative plastic solvent-free film provided by the present invention successfully solves the technical problems in the prior art through multi-layer structure design and specific process parameter control. The prepared product has excellent embossing performance and physical properties, while maintaining extremely low VOCs emission, and has significant technical effects.

[0077] In order to further verify the effect of the decorative plastic solvent-free film provided by the present invention in practical applications, the following application tests were conducted:

[0078] Application example 1: Furniture veneer

[0079] The decorative plastic solvent-free film prepared in Example 1 is applied to the surface of wooden furniture for coating. The specific steps are as follows:

[0080] 1. Polish the surface of wooden furniture and remove dust;

[0081] 2. Use PUR hot melt adhesive to laminate the solvent-free film to the furniture surface at 180°C;

[0082] 3. Press with a cold press at a pressure of 0.5 MPa for 30 seconds.

[0083] Test results: The surface of the furniture after bonding is smooth and flat, the embossing effect is clear, there is no obvious change after 3000 hours of accelerated aging test, and there is no warping or bubbling after being placed in a 60℃ environment for 30 days.

[0084] Application example 2: Automotive interior parts

[0085] The decorative plastic solvent-free film prepared in Example 2 is applied to the surface decoration of the automobile instrument panel. The specific steps are as follows:

[0086] 1. Treat the surface of ABS substrate with plasma;

[0087] 2. Use polyurethane adhesive to laminate the solvent-free film to the substrate;

[0088] 3. The vacuum lamination process is used for molding.

[0089] Test results: The surface decoration effect of the formed dashboard is excellent. After 100 cycles of temperature testing from -40℃ to 85℃, there is no cracking or deformation, and the wear resistance meets the requirements of automotive interior parts.

[0090] Application example 3: Electronic product housing

[0091] The decorative plastic solvent-free film prepared in Example 3 is applied to the surface decoration of the notebook computer shell. The specific steps are as follows:

[0092] 1. Clean the surface of PC / ABS shell;

[0093] 2. Use two-component polyurethane adhesive for compounding;

[0094] 3. The hot autoclave process is used for pressing, the temperature is 160℃ and the pressure is 0.6MPa.

[0095] Test results: The surface texture of the composite shell is clear and the touch is delicate. After 20,000 opening and closing tests, there is no cracking and the wear resistance is good.

[0096] Durability test: In order to verify the long-term performance of the decorative plastic solvent-free film prepared by the present invention, the following durability test was conducted:

[0097] Table 3: Durability test results

[0098]

[0099] Stability test: In order to verify the stability of the decorative plastic solvent-free film prepared by the present invention under different environments, the following tests were conducted:

[0100] Table 4: Environmental adaptability test results

[0101]

[0102] According to the above application examples and test results, we can see that:

[0103] 1. The decorative plastic solvent-free film prepared by the present invention has excellent practical application effects and can be widely used in the fields of furniture, automobile interiors, electronic product housings, etc.;

[0104] 2. In the durability test, Examples 1-3 showed excellent heat resistance, cold resistance, UV resistance and mildew resistance, which were significantly better than the comparative examples;

[0105] 3. In the environmental adaptability test, Examples 1-3 showed excellent stability and maintained good performance under various extreme environmental conditions.

[0106] Process parameter optimization study: In order to further explore the influence of process parameters on product performance, the present invention conducted the following optimization studies:

[0107] 1. Research on coating amount optimization

[0108] Through a systematic study of the coating amount of the top layer, middle layer, and bottom layer, the following results were obtained:

[0109] Table 5: Effect of different coating amounts on product performance

[0110]

[0111] Research shows that when the coating amount of the three layers is less than 180 / 180 / 200, the overall performance of the product will be significantly reduced; when the coating amount exceeds 250 / 250 / 300, the performance improvement is not obvious, but the production cost will increase; therefore, the optimal coating amount range is: surface layer 180-250g / m 2 , middle layer 180-250g / m 2 , bottom layer 200-300g / m 2 .

[0112] 2. Temperature parameter optimization research

[0113] The temperature parameters of each process are optimized, and the results are as follows:

[0114] Table 6: Effect of temperature parameters on product performance

[0115]

[0116] 3. Research on time parameter optimization

[0117] Table 7: Effect of time parameters on product performance

[0118] Process Time range(s) Best time(s) Critical Control Points Surface drying 45-75 60 Fully cured Middle layer drying 60-90 75 Interlayer bonding Bottom drying 120-180 160 Fully cured Embossing preheating 10-20 15 Uniform heating Base material mixing 30-40 35 Degree of reaction

[0119] 4. Study on the synergistic effect of process parameters

[0120] The study found that there is a clear synergistic effect between the process parameters:

[0121] a) Temperature-time synergistic effect:

[0122] Higher temperatures can shorten the curing time, but are more likely to cause surface defects; lower temperatures require longer curing time, but the product quality is more stable; the best solution is to use a gradient heating method to ensure sufficient curing and avoid defects.

[0123] b) Coating amount-temperature synergy effect:

[0124] The larger the coating amount, the higher the curing temperature or longer the curing time is required; the smaller the coating amount, the more critical the temperature control is, and insufficient curing is prone to occur.

[0125] Based on the above research results, the following process parameter optimization was established:

[0126] 1. Optimization of surface preparation:

[0127] Coating amount: controlled at 180-250g / m 2 Within the range,

[0128] Temperature: Four-stage gradient heating is adopted to ensure full curing.

[0129] Time: Adjust according to the coating amount, the base value is 60 seconds.

[0130] 2. Optimization of intermediate layer preparation:

[0131] Coating amount: Matches the surface layer, usually the same as the surface layer,

[0132] Temperature: Four-stage gradient heating is adopted to ensure the bonding between layers.

[0133] Time: 75 seconds as the benchmark, adjusted according to actual working conditions.

[0134] 3. Optimization of bottom layer preparation:

[0135] Coating amount: controlled at 200-300g / m 2 Within the range,

[0136] Temperature: Seven-stage precise temperature control is adopted to ensure full curing.

[0137] Time: controlled at about 160 seconds to ensure that VOCs are fully volatilized.

[0138] 4. Embossing process optimization:

[0139] Preheating temperature: around 170℃ is the best.

[0140] Preheating time: 15 seconds is appropriate, embossing speed: 12m / min is optimal.

[0141] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0142] The above is a detailed introduction to the preparation method of a decorative plastic solvent-free film provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a decorative plastic solvent-free film, the solvent-free film comprising a three-layer structure of a polyether embossable surface layer (1), a polyester thermosetting middle layer (2) and a polyether solvent-free bottom layer (3), characterized in that The method comprises the following steps: S1. Prepare the surface layer: mix the polyether resin, color paste and additives according to the ratio, control the viscosity of the surface paste to 4500-5500cps, use a D-type scraper to scrape the color paste onto the release paper, and dry it at 70℃ / 80℃ / 90℃ / 125℃ gradient to make the surface film material; S2. Preparation of the middle layer: Mix the water-based polyester resin, colorant and additives according to the proportion, control the viscosity to 4000-6000cps, use a D-type knife to scrape the color paste onto the surface film material, and dry it at 80℃ / 90℃ / 115℃ / 130℃ gradient to combine the surface film material with the middle film material; S3, preparing the bottom layer: mixing polyether polyurethane, isocyanate-terminated polyurethane prepolymer and an appropriate amount of catalyst; uniformly stirring the polyether polyurethane and isocyanate-terminated polyurethane prepolymer in a weight ratio of 100:50-100, applying the materials on the middle layer through a coating head, and controlling the material mixing time to not exceed 40 seconds; The obtained bottom layer material is dried in a gradient oven at 110°C / 115°C / 120°C / 120°C / 120°C / 130°C / 130°C, and a polyimide (PI) release film is attached to the slurry when it is in a relatively dry state to obtain a product.

2. The preparation method according to claim 1, characterized in that: The method further includes S4, post-processing: the post-processing includes printing and embossing the surface of the film material and separating the film material, wherein: The embossing process is: preheat the solvent-free film attached to the PI release film at 160-180℃ to soften the surface of the film, and then emboss it through a cold pressing device. The embossing speed is controlled at 10-15m / min. Membrane material separation is: the membrane material and PI release film are separated by a separator, the speed of the separator is controlled at 8-10m / min, and the tension is controlled within 50N.

3. The preparation method according to claim 1, characterized in that The printing process is as follows: using a polycarbonate printing material, printing the surface of the film material through a 100-mesh roller, with a coating amount of 20 g, to protect the surface condition of the product during embossing and reduce the damage to the embossing roller pattern caused by the shedding of the surface material.

4. The preparation method according to claim 1, characterized in that: The surface layer formula includes: 100 parts of water-based polyether polyurethane resin (solid content 30%±5%), several parts of water-based color paste, 3-5 parts of slip agent, 0.1-0.5 parts of defoamer, 0.8-1.2 parts of leveling agent and 1-2 parts of cross-linking agent, and the coating amount is 180-250g / m 2 ; The intermediate layer formula includes: 100 parts of water-based polyester resin (solid content 30% ± 5%), several parts of water-based colorant, 0.1-0.5 parts of defoamer, 0.8-1.2 parts of leveling agent, and the coating amount is 180-250g / m 2 ; The bottom layer formula includes: 100 parts of polyether polyurethane, 50-100 parts of isocyanate-terminated polyurethane prepolymer, 0.3-0.6 parts of dibutyltin dilaurate, 0.3-0.6 parts of bismuth isooctanoate, and the coating amount is 200-300g / m 2 .

5. The preparation method according to claim 1, characterized in that: The surface layer uses polytetramethylene glycol with a molecular weight of not less than 2000 as a soft segment and ethylene glycol as a hard segment to form a full polyether surface layer to ensure that the product has good embossing performance and use performance.

6. The preparation method according to claim 1, characterized in that: The middle layer adopts polyester diol with a molecular weight of 2000 made from adipic acid and ethylene glycol, which is used to enhance the thermosetting property and physical properties of the product.

7. The preparation method according to claim 1, characterized in that: The surface layer is dried at 60-130℃, 45-75s; the middle layer is dried at 70-140℃, 60-90s; the bottom layer is dried at 100-140℃, 120-180s; the embossing is preheated at 150-190℃, 10-20s; the bottom layer material is mixed for 30-40s.

8. A decorative plastic solvent-free film prepared according to the preparation method of claim 1.

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