A method for preparing high-thickness silicone transfer label

Abstract

The application discloses a preparation method of high-thickness silicone transfer printing identification, which comprises the following steps: S1, preparing a digital printing bottom layer film, comprising S11, coating a cold-tear resin release agent on a base material to obtain a release base material; S12, coating a wear-resistant layer on the release base material; S13, coating a primer layer on the wear-resistant layer; S14, after corona treatment of the primer layer, digitally printing a pattern on the primer layer; S15, coating a silicone layer on the digital printing pattern; S2, preparing a middle layer rubber film; S3, locking a mold on the middle layer rubber film, wherein the mold is provided with a hollow part corresponding to the pattern; S4, adding silicone into the hollow part of the mold, then covering the digital printing bottom layer film on the silicone, and aligning the digital printing pattern with the mold; and S5, vulcanizing and shaping the silicone. The prepared silicone transfer printing identification has high thickness, cannot cause edge overflow of silicone, and has wear resistance and water washing resistance.

Description

Technical Field

[0001] This invention relates to the field of silicone transfer marking technology, and in particular to a method for preparing high-thickness silicone transfer markings. Background Technology

[0002] In existing silicone transfer label manufacturing processes, liquid silicone is often directly coated or screen printed multiple times until the silicone transfer label reaches the required thickness.

[0003] For example, Chinese patent CN109334293A discloses a method for preparing a heat-transferable silicone transfer label. The method includes the following steps: Step 1: Mix addition-type liquid silicone, color paste, and curing agent evenly according to a certain ratio to obtain printing silicone; Step 2: Print the printing silicone onto a release sheet, and bake it dry after each printing, then print the next time until the required thickness is achieved; Step 3: Prepare a crosslinking agent; Step 4: Print the evenly prepared crosslinking agent onto the surface of the obtained product, and bake it dry each time; Step 5: Add a thinner to the hot melt adhesive, stir evenly, print it on the front side of the product from Step 4, and place it; Step 6: Place the above product in a multi-layer rack, put it in an oven, and control the temperature and time to obtain a silicone transfer label; Step 7: Press the front and back sides together.

[0004] Preparing silicone transfer labels through multiple liquid silicone printing processes presents numerous technical challenges, primarily including: requiring at least 10 printing passes when the silicone thickness exceeds 0.3mm; furthermore, as the silicone thickness increases and the layer becomes relatively soft, issues such as printing position deviations and edge overflow can occur, affecting the quality of the silicone transfer labels. Moreover, the multiple printing steps are cumbersome.

[0005] In view of this, the present invention proposes a method for preparing high-thickness silicone transfer markings to solve the above problems. Summary of the Invention

[0006] To overcome the shortcomings of the above-mentioned technologies, this invention provides a method for preparing high-thickness silicone transfer labels. By optimizing the preparation process, digital printing technology is used to achieve precise transfer of patterns. Combined with mold design and vulcanization molding process, silicone transfer labels with high thickness, high wear resistance, clear patterns and stable quality are successfully prepared.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing high-thickness silicone transfer markings includes the following steps:

[0009] S1: Preparing a digital printing base film, including: S11: Coating a cold-peel resin release agent onto a substrate to obtain a release substrate; S12: Coating a wear-resistant layer onto the release substrate; S13: Coating a base layer onto the wear-resistant layer; S14: Digitally printing a pattern onto the base layer after corona treatment; S15: Coating a silicone layer onto the digitally printed pattern.

[0010] S2: Preparation of the middle layer adhesive film;

[0011] S3: Lock the mold onto the middle layer of adhesive film; the mold has a cutout corresponding to the pattern.

[0012] S4: Add silicone into the hollow of the mold, then cover the silicone with the digital printing bottom film, and align the digital printing pattern with the mold.

[0013] S5: Curing silicone into shape;

[0014] S6: Cut out the excess digital printing base film and middle adhesive film.

[0015] Preferably, step S2 involves forming an intermediate adhesive film by coating the adhesive film with silicone.

[0016] Preferably, the adhesive film is one of TPU, PA, or PU adhesive films.

[0017] Preferably, the silicone thickness in the mold is greater than 0.1 mm.

[0018] Preferably, the substrate is CPP.

[0019] Preferably, the wear-resistant layer comprises acrylic resin and polyethylene wax, and has a thickness of 0.001 to 0.01 mm.

[0020] Preferably, the base coating comprises a polyurethane copolymer with a thickness of 0.001 to 0.01 mm.

[0021] Preferably, in S3, the middle layer adhesive film is placed on a workbench, and multiple molds are placed on the middle layer adhesive film. The molds are fixedly connected to each other, and the molds near the edge of the middle layer adhesive film are fixedly connected to the workbench, so that the molds are pressed tightly on the middle layer adhesive film.

[0022] Preferably, in S4, the digitally printed underlayer film is applied over the silicone, then a cover plate is applied over the digitally printed underlayer film, and then vulcanization is performed.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This invention locks the mold on the middle layer of adhesive film and adds silicone to the mold. The digitally printed bottom layer film covers the silicone, and then the silicone is vulcanized. Under the constraint of the mold, there will be no overflow of silicone at the edge of the transfer mark. Compared with the traditional method of preparing silicone transfer marks by printing multiple times, this invention adds silicone to the mold in one step and then vulcanizes it, which is more suitable for preparing high-thickness silicone transfer marks. It does not require repeated silicone printing, which not only simplifies the preparation steps, but also avoids the problem of positional deviation caused by repeated printing.

[0025] 2. This invention uses digital printing technology to directly print patterns on the base layer. Compared with traditional printing processes, digital printing has higher precision and flexibility, and can achieve accurate transfer of complex patterns, gradient colors and tiny text.

[0026] 3. Both the digital printing base film and the intermediate adhesive film are coated with silicone. During the vulcanization process, the silicone in the digital printing base film, the silicone in the mold, and the silicone in the intermediate adhesive film cross-link, resulting in a strong bond between the digital printing base film, the intermediate silicone, and the intermediate adhesive film. Specifically, the digital printing base film also includes a wear-resistant layer to protect the digitally printed pattern and the intermediate silicone. The adhesive film is one of TPU, PA, or PU adhesive films, which improves the overall washability of the adhesive film. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the high-thickness silicone transfer mark obtained using the present invention;

[0028] Figure 2 This is a schematic diagram of the digital printing base film and mold using the present invention;

[0029] The implementation, functional features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0030] The following examples further illustrate the features and other related characteristics of the present invention in detail, to facilitate understanding by those skilled in the art:

[0031] like Figures 1-2 As shown, an embodiment of the present invention provides a method for preparing high-thickness silicone transfer markings, comprising the following steps:

[0032] S1: Preparing the digital printing base film 7 includes: S11: Coating a cold-peel resin release agent 72 onto a substrate 71 to obtain a release substrate; S12: Coating a wear-resistant layer 73 onto the release substrate; S13: Coating a base layer 74 onto the wear-resistant layer 73; S14: Digitally printing a pattern 75 onto the base layer 74 after corona treatment; S15: Coating a silicone layer 76 onto the digitally printed pattern 75.

[0033] S2: Preparation of the middle layer adhesive film 9;

[0034] S3: Lock the mold 91 onto the middle layer adhesive film 9. The mold 91 has a hollowed-out shape corresponding to the pattern 75.

[0035] S4: Add silicone 8 into the hollow of the mold 91, and then cover the silicone 86 with digital printing bottom film 7, and align the digital printing pattern 75 with the mold 91.

[0036] S5: Curing silicone into shape;

[0037] S6: Cut out the excess digital printing bottom layer film 7 and middle layer adhesive film 9.

[0038] In some embodiments, S2 is performed by coating a silicone 92 onto a film 93 to form an intermediate film 9.

[0039] In some embodiments, the adhesive film 93 is one of TPU, PA, or PU adhesive films.

[0040] In some embodiments, the silicone thickness in the mold 91 is greater than 0.1 mm.

[0041] In some embodiments, the substrate 71 is CPP.

[0042] In some embodiments, the wear-resistant layer 73 comprises acrylic resin and polyethylene wax, and has a thickness of 0.001 to 0.01 mm.

[0043] In some embodiments, the base coating 74 comprises a polyurethane copolymer with a thickness of 0.001 to 0.01 mm, which can increase the interfacial adhesion of the wear-resistant layer 73 and facilitate the adhesion of digital ink.

[0044] In some embodiments, in S3, the intermediate adhesive film 9 is placed on a workbench, and a plurality of molds 91 are placed on the intermediate adhesive film 9. The molds 91 are fixedly connected to each other, and the molds 91 near the edge of the intermediate adhesive film 9 are fixedly connected to the workbench and pressed tightly onto the intermediate adhesive film 9.

[0045] In some embodiments, in S4, the digital printing underlayer film 7 is covered on silicone, and then a cover plate is covered on top of the digital printing underlayer film 7, so that the silicone of the digital printing underlayer film 7 adheres to the silicone in the mold 91, and then vulcanization is performed.

[0046] In some embodiments, the mold 91 is made of copper, which has good thermal conductivity and is beneficial for the molding of vulcanized silicone.

[0047] Example 1 provides a silicone transfer mark, the preparation method of which includes the following steps:

[0048] S11: Apply cold-peel resin release agent 72 to the CPP substrate and dry it to obtain the release substrate.

[0049] S12: Coat a mixture of acrylic resin and polyethylene wax onto a release substrate, wherein the mass ratio of acrylic resin to polyethylene wax in the mixture is 1:10, and dry to form a wear-resistant layer with a thickness of 0.005 mm.

[0050] S13: Apply a primer containing a polyurethane copolymer onto the wear-resistant layer, and dry it to form a primer layer with a thickness of 0.005 mm.

[0051] S14: After applying an 800-1200W corona base coat, digitally print a pattern on the base coat.

[0052] S15: Apply a silicone layer with a thickness of 0.005mm to the digitally printed pattern;

[0053] S2: Coat the TPU film with silicone to form an intermediate film.

[0054] S3: The middle layer of adhesive film is placed on the worktable, and multiple molds are placed on the middle layer of adhesive film. The molds have cutouts corresponding to the patterns. The molds are fixedly connected to each other, and the molds near the edge of the middle layer of adhesive film are fixedly connected to the worktable, so that the molds are pressed tightly on the middle layer of adhesive film.

[0055] S4: Add 0.3mm thick silicone to the hollow part of the mold, then cover the silicone with the digital printing base film, and align the digital printing pattern with the mold.

[0056] S5: Cover the digital printing base film with a cover plate, so that the silicone of the digital printing base film adheres to the silicone in the mold, and then vulcanize. Vulcanization conditions: 150℃, vulcanization time 400s.

[0057] S6: Cut out the excess digital printing base film and middle adhesive film.

[0058] Example 2 provides a silicone transfer mark, the preparation method of which is the same as in Example 1 except that the silicone thickness added into the mold in S4 is 0.4 mm, the vulcanization conditions are 165℃ and the vulcanization time is 530s.

[0059] Comparative Example 1 provides a silicone transfer mark, the preparation method of which includes S11-14 of Example 1 to obtain a digital printing base film; then, silicone mesh is printed onto the digital printing base film by a wire, and the silicone layer is dried after each printing before printing the next time, until the silicone layer thickness reaches 0.3 mm.

[0060] Comparative Example 2 provides a silicone transfer mark, the preparation method of which is the same as in Example 1 except that a silicone layer with a thickness of 0.005 mm is not coated on the digital printing base film, and the TPU film is directly covered on the mold without being coated with silicone.

[0061] Performance testing

[0062] 1. Observe the edge of the silicone transfer mark under a microscope and calculate the edge glue overflow rate = glue overflow area / area of ​​standard silicone transfer mark × 100%.

[0063] 2. Test the peel strength between the digital printing base film and the silicone layer according to GB / T 2792 standard.

[0064] III. Test the water resistance of silicone transfer markings according to AATCC 135 standard.

[0065] Table 1. Performance test results of Examples 1-2 and Comparative Examples 1-2

[0066] Example 1 0 15.2 >50 times without falling off Example 2 0 15.4 >50 times without falling off Comparative Example 1 9.5％ 9.5 30 instances of localized cracking Comparative Example 2 0 6.3 20 layers

[0067] (1) As can be seen from the above test results, in Comparative Example 1, silicone was screen-printed multiple times on the digital printing base film to form a silicone transfer mark with a thickness of 0.3mm. However, there was glue overflow at the edges. This is because silicone has fluidity, and as the thickness of the silicone increases, and the silicone layer is relatively soft, printing position deviations will occur. However, in Examples 1 and 2, by locking the mold on the middle layer of adhesive film and then injecting adhesive into the mold, the glue overflow at the edges can be avoided.

[0068] (2) As can be seen from the comparison between Examples 1 and 2 and Comparative Example 2, the connection strength between the digital printing bottom film coated with silicone and the high-thickness silicone layer (i.e., the silicone in the mold) is better. This is because the silicone of the digital printing bottom film and the high-thickness silicone layer undergo an addition reaction at the interface during the vulcanization process to form a Si-C-Si covalent bond network, which makes the silicone completely cross-linked into one.

[0069] (3) As can be seen from the comparison between Examples 1-2 and Comparative Examples 1-2, the middle layer film and the digital printing bottom layer film can improve the water resistance of silicone transfer markings.

[0070] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing high-thickness silicone transfer markings, characterized in that, Includes the following steps: S1: Preparation of the digital printing base film, including: S11: Apply a cold-peel resin release agent to the substrate to obtain a release substrate; S12: Apply a wear-resistant layer to the release substrate; S13: Apply a base coat to the wear-resistant layer; S14: Digitally print a pattern on the base coating after corona coating; S15: Apply a silicone layer to the digitally printed pattern; S2: A middle layer adhesive film is obtained by coating the adhesive film with silicone. S3: Lock the mold onto the middle layer of adhesive film; the mold has a cutout corresponding to the pattern. S4: Add silicone into the hollow of the mold, then cover the silicone with the digital printing bottom film, and align the digital printing pattern with the mold. S5: Curing the silicone into shape; During the curing process, an addition reaction occurs at the interface between the silicone layer of the bottom film and the silicone in the mold, forming a Si-C-Si covalent network, which crosslinks the silicone layer with the silicone in the mold into one piece; S6: Cut out the excess digital printing base film and middle adhesive film.

2. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, The adhesive film is one of TPU, PA, or PU adhesive films.

3. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, The silicone thickness in the mold is greater than 0.1 mm.

4. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, The substrate is CPP.

5. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, The wear-resistant layer comprises acrylic resin and polyethylene wax, with a thickness of 0.001~0.01mm.

6. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, The base coating comprises a polyurethane copolymer with a thickness of 0.001~0.01 mm.

7. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, In S3, the middle layer adhesive film is placed on the worktable, and multiple molds are placed on the middle layer adhesive film. The molds are fixedly connected to each other, and the molds near the edge of the middle layer adhesive film are fixedly connected to the worktable, so that the molds are pressed tightly on the middle layer adhesive film.

8. The method for preparing a high-thickness silicone transfer mark according to claim 1, characterized in that, In S4, the digitally printed underlayer film is applied over the silicone, then a cover plate is applied over the digitally printed underlayer film, and then vulcanization is performed.

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