Out-of-mold decoration method based on strippable transfer film

Abstract

The invention discloses an out-of-mold decoration method based on a strippable transfer film, which comprises the following steps: coating UV gloss oil on the surface of a release film, baking, and curing by an LED lamp to form a UV layer; coating gloss oil on the surface of the UV layer and baking to obtain a gloss oil layer; printing pattern colors on the surface of the gloss oil layer and baking to obtain a pattern color layer; the surface of the pattern color layer is coated with glue, a bonding layer is formed after baking, and a protective film is attached to the bonding layer to obtain the peelable transfer film; after the protective film of the strippable transfer film is torn off, the bonding layer is attached to the injection molding part through DOD differential pressure coating decoration equipment; and after the release film is torn off, carrying out secondary curing on the UV layer through a mercury lamp. The formula of the UV layer is optimized, the low-energy LED lamp is adopted for primary curing, it is ensured that the UV layer has good flexibility and stretchability, and after the UV layer is attached to an injection molding part, secondary curing is conducted on the UV layer through the high-energy mercury lamp, so that the UV layer has good abrasion resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of out-mold decoration, in particular to an out-mold decoration method based on a peelable transfer film. BACKGROUND

[0002] The OMD (out-mold decoration) process does not need cutting jigs, stamping jigs, and injection molding jigs, has obvious advantages of low mold opening cost and short sample making period. The OMD process is currently in the initial stage of application and has great growth space in the future. The film types that can be currently selected for the OMD process are not many, mainly including PVC, PC, PET, ABS, and other types of printed and embossed films. However, these films are generally thick, with a thickness of about 0.2-0.5 mm, and cannot be made thinner, which has great limitations for industries with relatively precise assembly structures and strict size requirements, because the too thick film will affect the assembly of workpieces.

[0003] The peelable transfer (OMR) film has a total thickness of 35-55 un, is suitable for application of the OMD process to industries with relatively precise assembly structures and strict size requirements such as mobile phones and notebook computers, and is transferred to ABS / PC injection molded parts by a DOD differential pressure coating decoration device under vacuum differential coating process conditions. Since the OMR film is stretched by 30%-100% when being transferred to the injection molded parts by the DOD differential pressure coating decoration device, the UV hardening layer in the OMR film has high requirements for flexible stretchability. The surface performance of the injection molded parts after the film is transferred to the injection molded parts is determined by the UV hardening layer of the film, and generally, if the UV hardening layer has good flexible stretchability, the wear resistance will not be good, and the stretchability and wear resistance cannot be combined. SUMMARY

[0004] The present application provides an out-mold decoration method based on a peelable transfer film, in which low-energy LED lamps are used for curing in the preparation process of the peelable transfer film, so as to ensure that the UV layer has good flexible stretchability and meets the stretching requirements in the DOD differential pressure coating decoration process; and after being attached to the injection molded parts, the UV layer is secondarily cured by high-energy mercury lamps, so that the UV layer has good wear resistance. The UV layer of the process can not only ensure a certain flexibility and meet the stretchability requirements in the DOD differential pressure coating process, but also meet the surface wear resistance requirements of the injection molded parts on the UV layer.

[0005] To solve the above technical problems, the present application provides an out-mold decoration method based on a peelable transfer film, comprising the following steps:

[0006] S1, peelable transfer film preparation:

[0007] S11, coating UV light oil on the surface of the release film, curing by LED lamp after baking to form a UV layer;

[0008] S12, coating light oil on the surface of the UV layer and baking to obtain a light oil layer;

[0009] S13, printing pattern color on the surface of the light oil layer and baking to obtain a pattern color layer;

[0010] S14, coating glue on the surface of the pattern color layer, forming an adhesive layer after baking, and attaching a protective film to obtain a peelable transfer film;

[0011] S2, after removing the protective film of the peelable transfer film, the adhesive layer is attached to the injection molded part by DOD differential pressure coating decoration equipment;

[0012] S3, after removing the release film, the UV layer is exposed and the UV layer is secondarily cured by a mercury lamp.

[0013] The UV layer formula is optimized, and in the peelable transfer film preparation process, low-energy LED lamp curing is adopted to ensure that the UV layer has good flexible stretching performance, meeting the stretching requirements in the DOD differential pressure coating decoration process; the peelable transfer film is transferred to the injection molded part under the vacuum differential coating process condition by the DOD differential pressure coating decoration equipment, and after being attached to the injection molded part, the UV layer is secondarily cured by a high-energy mercury lamp, so that the UV layer has good wear resistance. The process UV layer can not only ensure a certain flexibility to meet the stretching requirements in the DOD differential coating process, but also meet the surface wear resistance requirements of the injection molded part on the UV layer.

[0014] Further, the conditions for LED lamp curing are that the light wavelength is 380-400 nm, the energy is 50-300 mJ / cm 2 , and the light intensity is 200-400 mW / cm 2 . The first curing adopts low-energy LED lamp to ensure that the UV layer has appropriate flexible stretching performance.

[0015] Further, the conditions for the mercury lamp to secondarily cure the UV layer are that the energy is 600-1200 mJ / cm 2 , and the light intensity is 300-1000 mW / cm 2 . The second curing adopts high-energy function to improve the wear resistance of the UV layer.

[0016] Further, the UV light oil includes, in parts by mass, high-functionality polyurethane acrylate 42-55 parts, low-functionality polyurethane acrylate 10-20 parts, ethyl acetate 15-25 parts, dipentaerythritol hexaacrylate 5-15 parts, pentaerythritol triacrylate 3-10 parts, TPO (high-performance thermoplastic elastomer) 0.3-1 part, photoinitiator 1.5-3 parts, leveling agent 0.3-1 part.

[0017] Further, the photoinitiator includes photoinitiator 184 1-2 parts, photoinitiator MBF 0.5-1 part.

[0018] Further, the peelable transfer film has a thickness of 35-55 μm. The overall thickness of the film sheet is thin, and can be applied to industries that are relatively precise in assembly structure and strict in size requirements.

[0019] Further, in steps S11-S14, the baking conditions are independently selected from the group consisting of temperature 60-80℃, time 5-30 min.

[0020] Further, the material of the injection molding part is ABS or PC.

[0021] Further, the release film is a planar release film or a textured release film.

[0022] Further, the release film is further provided with a base film on the side away from the UV layer.

[0023] Advantages of the present application:

[0024] The present application optimizes the UV layer formula, and uses low-energy LED lamps for curing in the process of preparing the peelable transfer film, so as to ensure that the UV layer has good flexible stretching performance and meets the stretching requirements in the DOD differential pressure decoration process.

[0025] The peelable transfer film of the present application is transferred to the injection molding part by the DOD differential pressure decoration equipment under the condition of vacuum differential pressure film coating process, and after being attached to the injection molding part, the UV layer is secondarily cured by high-energy mercury lamps, so that the UV layer has good wear resistance.

[0026] The UV layer of the present application can ensure a certain flexibility, meet the stretching requirements in the DOD differential pressure film coating process, and also meet the surface wear resistance requirements of the injection molding part on the UV layer. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described below are only embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 is a schematic diagram of the peelable transfer film structure of embodiment 1 of the present application;

[0029] Figure 2 is a schematic diagram of the peelable transfer film structure of embodiment 1 of the present application. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below in conjunction with specific embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] The present embodiment relates to an off-mold decoration method based on a peelable transfer film, comprising the following steps:

[0032] S1, peelable transfer film preparation:

[0033] S11, coating UV varnish on the surface of the release film, and curing by LED lamp after baking to form a UV layer;

[0034] wherein, by mass fraction, the UV varnish comprises: high functionality polyurethane acrylate 42-55 parts, low functionality polyurethane acrylate 10-20 parts, ethyl acetate 15-25 parts, dipentaerythritol hexaacrylate 5-15 parts, pentaerythritol triacrylate 3-10 parts, TPO 0.3-1 part, photoinitiator 184 1-2 parts, photoinitiator MBF 0.5-1 part, leveling agent 0.3-1 part; the curing conditions of the LED lamp are: irradiation light wavelength 380-400 nm, energy 50-300 mJ / cm 2 , light intensity 200-400 mW / cm 2 ;

[0035] S12, coating varnish on the surface of the UV layer and baking to obtain a varnish layer;

[0036] S13, printing pattern color on the surface of the varnish layer and baking to obtain a pattern color layer;

[0037] S14, coating glue on the surface of the pattern color layer, forming an adhesive layer after baking, and adhering a protective film to obtain a peelable transfer film;

[0038] S2, after removing the protective film of the peelable transfer film, the adhesive layer is adhered to the injection molded part by a DOD differential pressure coating decoration device;

[0039] S3, after removing the release film, the UV layer is exposed and subjected to secondary curing by a mercury lamp.

[0040] The conditions for the mercury lamp to perform secondary curing on the UV layer are: energy 600-1200 mJ / cm 2 , light intensity: 300-1000 mW / cm 2 .

[0041] In this embodiment, the UV layer formula is optimized, and a low-energy LED lamp is used for curing during the preparation of the peelable transfer film, to ensure that the UV layer has good flexible stretching performance and meets the stretching requirements in the DOD differential pressure decoration process; the peelable transfer film is transferred to the injection molded part under the vacuum differential coating process conditions of the DOD differential pressure decoration equipment, and after being attached to the injection molded part, the UV layer is subjected to secondary curing by a high-energy mercury lamp, so that the UV layer has good wear resistance. The process UV layer can not only ensure a certain flexibility to meet the stretching requirements in the DOD differential coating process, but also meet the surface wear resistance requirements of the UV layer for the injection molded part.

[0042] As a preferred embodiment, the thickness of the peelable transfer film is 35-55 μm, and the overall thickness of the film sheet is thin, which can be suitable for industries with relatively precise assembly structures and strict size requirements. The material of the injection molded part is ABS or PC; the release film is a planar release film or a textured release film; the side of the release film away from the UV layer is also provided with a base film.

[0043] As a preferred embodiment, in steps S11-S14, the baking conditions are independently selected from: temperature 60-80℃, time 5-30min.

[0044] Example 1

[0045] This embodiment relates to an off-mold decoration method based on a peelable transfer film, comprising the following steps:

[0046] (1) Select a transparent PO film sheet with a thickness of 0.1-0.3 μm as a base film;

[0047] (2) Apply a release agent on the PO film sheet, and bake at 70℃ for 20min to obtain a release film;

[0048] (3) coating UV varnish on the surface of the release film, baking at 70°C for 5 min, and then curing by LED lamp to form a UV layer; wherein, the UV varnish comprises, by mass fraction: lucure8531 high functionality polyurethane acrylate 45 parts, DM584 low functionality polyurethane acrylate 15 parts, ethyl acetate 20 parts, dipentaerythritol hexaacrylate DPHA 10 parts, pentaerythritol triacrylate PETA 6 parts, TPO 1 part, photoinitiator 184 2 parts, photoinitiator MBF 0.5 part, leveling agent 0.5 part; the curing conditions of the LED lamp are: light wavelength 395 nm, energy 250 mJ / cm 2 , light intensity 300 mW / cm 2 ;

[0049] (4) coating varnish on the surface of the UV layer, baking at 70°C for 20 min to obtain a varnish layer;

[0050] (5) printing a pattern color on the surface of the varnish layer, baking at 70°C for 20 min to obtain a pattern color layer;

[0051] (6) coating glue on the surface of the pattern color layer, baking at 70°C for 20 min to form an adhesive layer, and then adhering a protective film to obtain a peelable transfer film, which comprises, in sequence, a base film, a release film, a UV layer, a varnish layer, a pattern color layer, an adhesive layer, and a protective film, as shown in Figure 1 ;

[0052] (7) after removing the protective film of the peelable transfer film, adhering the adhesive layer to an injection molded part by a DOD differential pressure decoration device;

[0053] (9) after removing the release film and the base film, exposing the UV layer, and then performing secondary curing on the UV layer by a mercury lamp; wherein, the secondary curing conditions of the UV layer by the mercury lamp are: energy 800 mJ / cm 2 , light intensity: 800 mW / cm 2 .

[0054] Example 2

[0055] The difference between this example and Example 1 is that a textured release film is prepared in step (2), and other steps and parameters remain unchanged, specifically:

[0056] (1) selecting a transparent PO film piece with a thickness of 0.1-0.3 μm as a base film;

[0057] (2) coating a polyolefin modified compound treatment agent on the PO film piece to improve adhesion, baking at 70°C for 20 min to obtain an adhesion layer; coating UV varnish on the adhesion layer, and then forming a textured release film after embossing and 600 mJ / cm 2 UV energy irradiation;

[0058] (3) coating UV varnish on the surface of the textured release film, baking at 70°C for 5 min, and then curing by LED lamp to form a UV layer; wherein, by mass fraction, the UV varnish comprises: lucure8531 high functionality polyurethane acrylate 45 parts, DM584 low functionality polyurethane acrylate 15 parts, ethyl acetate 20 parts, dipentaerythritol hexaacrylate DPHA 10 parts, pentaerythritol triacrylate PETA 6 parts, TPO 1 part, photoinitiator 184 2 parts, photoinitiator MBF 0.5 parts, leveling agent 0.5 parts; the curing conditions of the LED lamp are: light wavelength 395 nm, energy 250 mJ / cm 2 , light intensity 300 mW / cm 2 ;

[0059] (4) coating varnish on the surface of the UV layer, baking at 70°C for 20 min to obtain a varnish layer;

[0060] (5) printing a pattern color on the surface of the varnish layer, baking at 70°C for 20 min to obtain a pattern color layer;

[0061] (6) coating glue on the surface of the pattern color layer, baking at 70°C for 20 min to form an adhesive layer, and then laminating a protective film to obtain a peelable transfer film, which comprises a base film, an adhesive layer, a textured release film, a UV layer, a varnish layer, a pattern color layer, an adhesive layer and a protective film arranged in sequence, as shown in Figure 2 ;

[0062] (7) after the protective film of the peelable transfer film is removed, the adhesive layer is laminated with an injection molded part by a DOD differential pressure decoration device;

[0063] (9) after the textured release film, the adhesive layer and the base film are removed, the UV layer is exposed, and the UV layer is secondarily cured by a mercury lamp; wherein, the curing conditions of the UV layer by the mercury lamp are: energy 800 mJ / cm 2 , light intensity: 800 mW / cm 2 .

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that the UV varnish in step (3) does not contain TPO, and the LED lamp curing is replaced by mercury lamp curing, and other steps and parameters remain unchanged.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that the UV varnish in step (3) does not contain photoinitiator 184 / MBF, and other steps and parameters remain unchanged.

[0068] Comparative Example 3

[0069] The difference between the comparative example and Example 1 is that polyurethane acrylate 6071 is further included in the UV oil in step (3), and other steps and parameters are unchanged.

[0070] Comparative Example 4

[0071] The difference between the comparative example and Example 1 is that a mercury lamp is used for curing in step (3), and other steps and parameters are unchanged.

[0072] The performance test results of the products obtained by the off-mold decoration process of Examples 1-2 and Comparative Examples 1-4 are shown in Table 1, wherein the wear resistance test conditions of the UV layer are: steel wool 500g load, steel wool type: Bonstar 0000#, 200 times.

[0073] Table 1

[0074]

[0075] As can be seen from Table 1, the UV layer of the process of Examples 1-2 has good flexible stretching performance when being attached in the DOD differential pressure coating decoration equipment, the film appearance is normal, and the UV layer after attachment has excellent wear resistance, and the steel wool 500g 200 times test is OK.

[0076] As can be seen from the comparison between Comparative Example 1 and Example 1, when the UV oil does not contain TPO and is cured by a mercury lamp, the flexible stretching performance of the UV layer is poor, and the film cracks when being attached in the DOD differential pressure coating decoration equipment. In Comparative Example 2, the photoinitiator 184 / MBF is not included, and the wear resistance of the UV layer is poor. In Comparative Example 3, the low cross-linking degree polyurethane acrylate 6071 is increased, and the wear resistance of the UV layer is poor. In Comparative Example 4, the UV oil is cured by a mercury lamp, which results in poor flexible stretching performance of the film, and the film cracks when being attached in the DOD differential pressure coating decoration equipment.

[0077] In summary, by optimizing the formula of the UV layer, in the process of preparing the peelable transfer film, low-energy LED lamp curing is used to ensure that the UV layer has good flexible stretching performance, meeting the stretching requirements in the DOD differential pressure coating decoration process; the peelable transfer film is transferred to the injection molded part under the vacuum differential pressure coating process conditions by the DOD differential pressure coating decoration equipment, and after being attached to the injection molded part, the UV layer is secondarily cured by a high-energy mercury lamp, so that the UV layer has good wear resistance; the off-mold decoration process UV layer can not only ensure a certain flexibility to meet the stretching requirements in the DOD differential pressure coating process, but also meet the surface wear resistance requirements of the UV layer for the injection molded part.

[0078] The present application is described in detail above with reference to specific embodiments and exemplary examples, but these are not to be understood as limiting the present application. It is understood by a person skilled in the art that various equivalent substitutions, modifications or improvements can be made to the technical solutions of the present application and the embodiments thereof without departing from the spirit and scope of the present application, and these all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims.

Claims

1. An off mold decoration method based on a peelable transfer film, characterized in that, The method comprises the following steps: S1, preparing a peelable transfer film; S11, coating a UV varnish on the surface of the release film, curing by LED light after baking to form a UV layer; S12, coating a varnish on the surface of the UV layer and baking to obtain a varnish layer; S13, printing a pattern color on the surface of the varnish layer and baking to obtain a pattern color layer; S14, coating a glue on the surface of the pattern color layer, forming an adhesive layer after baking, and adhering a protective film to obtain a peelable transfer film; S2, after removing the protective film of the peelable transfer film, adhering the adhesive layer to an injection molded part by a DOD differential pressure coating decoration device; S3, after removing the release film, exposing the UV layer and performing secondary curing on the UV layer by a mercury lamp.

2. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The LED lamp curing condition is: irradiation light wavelength 380-400 nm, energy 50-300 mJ / cm 2 , light intensity 200-400 mW / cm 2 .

3. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The mercury lamp secondary cures the UV layer under the conditions of energy 600-1200 mJ / cm 2 , light intensity: 300-1000 mW / cm 2 .

4. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The UV varnish comprises, by mass fraction, 42-55 parts of high-functionality polyurethane acrylate, 10-20 parts of low-functionality polyurethane acrylate, 15-25 parts of ethyl acetate, 5-15 parts of dipentaerythritol hexaacrylate, 3-10 parts of pentaerythritol triacrylate, 0.3-1 part of TPO, 1.5-3 parts of a photoinitiator, and 0.3-1 part of a leveling agent.

5. The out-of-mold decoration method based on a peelable transfer film according to claim 4, characterized in that, The photoinitiator comprises 1-2 parts of photoinitiator 184 and 0.5-1 part of photoinitiator MBF.

6. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The peelable transfer film has a thickness of 35-55 μm.

7. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, In steps S11-S14, the baking condition is independently selected from the following: a temperature of 60-80℃ and a time of 5-30 min.

8. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The injection molded part is made of ABS or PC.

9. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The release film is a planar release film or a textured release film.

10. The out-of-mold decoration method based on a peelable transfer film according to claim 1, characterized in that, The side of the release film away from the UV layer is further provided with a base film.

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