High-speed thermal transfer ink for glass and method for preparing the same

Abstract

The application discloses a high-speed heat transfer printing glue for glass and belongs to the technical field of heat transfer printing glue. The heat transfer printing glue comprises the following substances: acrylic modified silicone resin, chlorinated polyolefin resin, acrylic modified rosin resin, thermoplastic polyurethane elastomer, latent isocyanate curing agent, organic tin catalyst, gamma-aminopropyl triethoxysilane, phosphate adhesion promoter, nano silicon dioxide, polytetrafluoroethylene micro powder, ultraviolet light absorber and surface wetting agent. The application reduces the time required for heat transfer printing, accelerates the operation construction of the heat transfer printing process, improves the production efficiency and saves the cost.

Description

Technical Field

[0001] This invention belongs to the field of heat transfer adhesive technology, and in particular relates to a high-speed heat transfer adhesive for glass and its preparation method. Background Technology

[0002] With the continuous advancement of heat transfer technology, its advantages in color durability, simplified printing process, and pattern clarity have become increasingly apparent, promoting the application and development of this process and opening up broad prospects. However, existing heat transfer adhesives face several challenges in heat transfer onto glass: slow transfer speeds (typically below 10 meters per minute), failing to meet the demands of continuous high-speed production in modern factories; insufficient initial adhesion after transfer, making the pattern prone to detachment under movement, impact, or touch, requiring a longer baking and curing time for good adhesion; the adhesive layer is prone to yellowing or bubbling under high-temperature baking in the later stages; and thorough cleaning of the glass surface before transfer is essential, otherwise adhesion will significantly decrease. These challenges limit the application of heat transfer technology on glass substrates.

[0003] Therefore, how to provide a heat transfer adhesive composition with excellent initial adhesion that can be used under high-speed transfer conditions and its preparation method, suitable for the industrial continuous production of products such as glass bottles, glasswares, and architectural glass, is a key problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of the technical problems in the prior art, the present invention provides a high-speed heat transfer adhesive for glass, which can achieve excellent transfer effect under high-speed transfer conditions (15-30 meters / minute) and meet the needs of continuous production in factories.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a high-speed heat transfer adhesive for glass, comprising the following components by mass fraction: 12-18% acrylic-modified silicone resin, 6-10% chlorinated polyolefin resin, 8-13% acrylic-modified rosin resin, 2-6% thermoplastic polyurethane elastomer, 5-8% latent isocyanate curing agent, 0.3-1% organotin catalyst, 0.5-3% γ-aminopropyltriethoxysilane, 0.5-2% phosphate ester adhesion promoter, 1-3% nano silica, 0.5-1% polytetrafluoroethylene micro powder, 0.3-0.8% ultraviolet light absorber, 0.05-0.2% surface wetting agent, and the balance being solvent.

[0006] Further, it includes the following components by mass fraction: 15% acrylic modified silicone resin, 8% chlorinated polyolefin resin, 10% acrylic modified rosin resin, 4% thermoplastic polyurethane elastomer, 6% latent isocyanate curing agent, 0.5% organotin catalyst, 0.8% γ-aminopropyltriethoxysilane, 1% phosphate ester adhesion promoter, 1% nano silica, 0.8% polytetrafluoroethylene micro powder, 0.5% ultraviolet light absorber, 0.1% surface wetting agent, and the balance being solvent.

[0007] Because acrylic-modified rosin provides good initial tack and thermoplastic polyurethane elastomer provides good flowability, coupled with the very high polarity of chlorinated polyolefin resin, the three work synergistically to produce excellent initial adhesion for transfer. The silane component forms chemical bonds with the glass surface at the moment of transfer. Organotin lowers the curing temperature by 15-20℃. Later, acrylic-modified organosilicon resin, chlorinated polyolefin resin, acrylic-modified rosin resin, and thermoplastic polyurethane elastomer are baked at 130-140 degrees for 10-20 minutes to form a permanent cured film. Various resins contain functional groups and can cross-link and cure with blocked isocyanates to form a permanent continuous film. Among them, thermoplastic polyurethane elastomer has good shrinkage properties, which can provide a certain degree of thermal expansion and contraction stress buffering for the film material from -10℃ to 75℃, ensuring that the transfer film has long-term adhesion under temperature changes.

[0008] Furthermore, the solvent is composed of ethyl acetate, PMA, methylcyclohexane, and butyl acetate.

[0009] Furthermore, the mass ratio of ethyl acetate, PMA, methylcyclohexane, and butyl acetate is 12:5:23:10.

[0010] Furthermore, the particle size of the nano-silica is 20-80 nm.

[0011] Another object of the present invention is to provide a method for preparing a high-speed heat transfer adhesive for glass, comprising the following steps: Step 1: Add acrylic-modified silicone resin, chlorinated polyolefin resin, acrylic-modified rosin resin, and thermoplastic polyurethane elastomer to a reaction vessel and heat to 55-65℃. Add 40-50% solvent and stir for 30-50 minutes until completely dissolved. Cool to 40℃ or below to obtain a resin mixture for later use. Step 2: Mix nano-silica with 1 / 3 of the remaining solvent and ultrasonically disperse for 10-30 minutes to obtain a uniform dispersion. Slowly add the dispersion to the resin mixture from Step 1. Then add the latent isocyanate curing agent and organotin catalyst. Stir for 5-15 minutes, then add γ-aminopropyltriethoxysilane, phosphate ester adhesion promoter, polytetrafluoroethylene micro powder, ultraviolet light absorber, surface wetting agent and all remaining solvent. Shear dispersion and filter with a filter bag to obtain high-speed heat transfer adhesive for glass.

[0012] Furthermore, the shearing speed in step 2 is 5000 rpm, and the time is 10 minutes.

[0013] Furthermore, the filter bag is 250 mesh. Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention reduces the time required for heat transfer printing, accelerates the operation of the heat transfer printing process, improves production efficiency, and saves costs.

[0014] 2. This invention improves the initial adhesion of the transfer onto glass (reaching 5B), facilitating subsequent construction and shortening the overall processing time of the product.

[0015] 3. In the entire hot-pressing process, the heat transfer adhesive of the present invention transforms from solid to liquid and then back to solid. The γ-aminopropyltriethoxysilane coupling agent in the heat transfer adhesive forms chemical bonds on the glass surface, greatly increasing the adhesion to the glass. Under high-temperature baking, the components of the latent isocyanate curing agent undergo chemical cross-linking to form a dense film, giving the final transfer coating excellent physical properties. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] Example 1

[0018] This embodiment provides a method for preparing high-speed heat transfer adhesive for glass, including the following steps: 1. Resin premixing: Add 15% acrylic modified silicone resin, 8% chlorinated polyolefin resin, 10% acrylic modified rosin resin, and 4% thermoplastic polyurethane elastomer to the reactor and heat to 55-65℃. Add 40-50% mixed solvent and stir for 30-50 minutes until completely dissolved. Cool to 40℃ or below to ensure that the solvent evaporates as little as possible.

[0019] 2. Additive dispersion: In another container, mix 1% nano silica (particle size 20-50nm) with 1 / 3 of the remaining solvent and ultrasonically disperse for 20 minutes to obtain a uniform dispersion. Slowly add the dispersion to the resin mixture in step one.

[0020] 3. Addition of functional components: Add 6% latent isocyanate curing agent, 0.5% organotin catalyst, stir for 10 minutes, add 0.8% γ-aminopropyltriethoxysilane, 1% phosphate ester adhesion promoter, 0.8% polytetrafluoroethylene micro powder, 0.5% ultraviolet light absorber, 0.1% surface wetting agent, and add the remaining solvent.

[0021] 4. Homogenization and filtration: Pass the mixture through a high-speed shear disperser (5000 rpm, 10 minutes). The material is filtered through a 250-mesh filter bag to remove any particles that may be present, thus obtaining a high-speed heat transfer adhesive for glass.

[0022] The heat transfer adhesive in Example 1 remained stable and did not delaminate even after being stored for more than 6 months.

[0023] Example 2

[0024] This embodiment provides a method for preparing high-speed heat transfer adhesive for glass, including the following steps: 1. Resin premixing: Add 12% acrylic modified silicone resin, 6% chlorinated polyolefin resin, 8% acrylic modified rosin resin, and 2% thermoplastic polyurethane elastomer to the reactor and heat to 55-65℃. Add 40-50% mixed solvent and stir for 30-50 minutes until completely dissolved. Cool down to 40℃ or below to ensure that the solvent evaporates as little as possible.

[0025] 2. Additive dispersion: In another container, mix 0.5% nano silica (particle size 20-50nm) with 1 / 3 of the remaining solvent and ultrasonically disperse for 20 minutes to obtain a uniform dispersion. Slowly add the dispersion to the resin mixture in step one.

[0026] 3. Addition of functional components: Add 5% latent isocyanate curing agent, 0.3% organotin catalyst, stir for 10 minutes, add 0.5% γ-aminopropyltriethoxysilane, 0.5% phosphate ester adhesion promoter, 0.5% polytetrafluoroethylene micro powder, 0.3% ultraviolet light absorber, 0.05% surface wetting agent, and add the remaining solvent.

[0027] 4. Homogenization and filtration: Pass the mixture through a high-speed shear disperser (5000 rpm, 10 minutes). The material is filtered through a 250-mesh filter bag to remove any particles that may be present, thus obtaining a high-speed heat transfer adhesive for glass.

[0028] The heat transfer adhesive in Example 2 remained stable and showed no delamination even after being stored for more than 6 months.

[0029] Example 3

[0030] This embodiment provides a method for preparing high-speed heat transfer adhesive for glass, including the following steps: 1. Resin premixing: Add 18% acrylic modified silicone resin, 10% chlorinated polyolefin resin, 13% acrylic modified rosin resin, and 6% thermoplastic polyurethane elastomer to the reactor and heat to 55-65℃. Add 40-50% mixed solvent and stir for 30-50 minutes until completely dissolved. Cool to 40℃ or below to ensure that the solvent evaporates as little as possible.

[0031] 2. Additive dispersion: In another container, mix 1.5% nano silica (particle size 20-50nm) with 1 / 3 of the remaining solvent and ultrasonically disperse for 20 minutes to obtain a uniform dispersion. Slowly add the dispersion to the resin mixture in step one.

[0032] 3. Addition of functional components: Add 8% latent isocyanate curing agent, 1% organotin catalyst, stir for 10 minutes, add 3% γ-aminopropyltriethoxysilane, 2% phosphate ester adhesion promoter, 1% polytetrafluoroethylene micro powder, 0.8% ultraviolet light absorber, 0.2% surface wetting agent, and add the remaining solvent.

[0033] 4. Homogenization and filtration: Pass the mixture through a high-speed shear disperser (5000 rpm, 10 minutes). The material is filtered through a 250-mesh filter bag to remove any particles that may be present, thus obtaining a high-speed heat transfer adhesive for glass.

[0034] The heat transfer adhesive in Example 3 remained stable and did not delaminate even after being stored for more than 6 months.

[0035] Comparative Example 1: Commercially available heat transfer adhesive. After 6 months of storage, it will show signs of separation and increased viscosity.

[0036] Application Example 1: High-speed transfer printing on glass bottles The heat transfer adhesive of Example 1 of this invention is applied to a PET transfer film with a dry adhesive thickness of 8-12 μm. The glass bottle surface is clean and at room temperature. The transfer temperature is set to 200°C, the transfer pressure to 0.4 MPa, and the transfer speed to 20 m / min. The heat-pressing contact time is approximately 0.4-0.6 seconds (depending on the thickness of the PET film, which is 0.019 mm-0.029 mm). After cooling for 3 minutes after the transfer, the next process can be carried out.

[0037] Comparative Example 1: Commercially available heat transfer adhesive was applied to a PET transfer film with a dry adhesive thickness of 8-12 μm. The glass bottle surface was clean and at room temperature. The transfer temperature was set to 200℃, the transfer pressure to 0.4 MPa, and the transfer speed to 10 m / min. The heat-pressing contact time was approximately 0.6-1 second (depending on the thickness of the PET film, which ranges from 0.019 mm to 0.300 mm). The film needed to be baked for 30 minutes before proceeding to the next step.

[0038] Compared with the traditional transfer printing process, the production time of this invention can be reduced by half.

[0039] Performance testing: Performance testing was performed on Example 1, and the results are as follows: Applicable transfer speed: 15-30 meters / minute; minimum effective transfer time: 4 seconds (150℃); wide transfer temperature range: good results can be obtained at 150-200℃.

[0040] Excellent initial adhesion: The adhesion reaches 5B (cross-cut test) within 2-5 minutes after transfer; subsequent printing, spraying and other processes can be carried out after 5 minutes; after baking at 170℃ for 15-20 minutes to fully cure, the adhesion reaches 5B, and it can pass the boiling water test. It has good resistance to yellowing.

[0041] Wide operating window: adaptable to glass surface temperature changes of ±10℃; reduced requirements for glass surface cleanliness, with a certain degree of anti-pollution ability; wide transfer pressure range (0.3-0.4MPa).

[0042] Finished product adhesion test: 5B at 1 minute, 5B at 10 minutes, and 5B at 24 hours.

[0043] Performance testing was performed on Example 1, and the results are as follows: Applicable transfer speed: 10-20 meters / minute; minimum effective transfer time: 4 seconds (180℃); wide transfer temperature range: 180-220℃ can achieve good results.

[0044] Excellent initial adhesion: Without baking after transfer, the adhesion cannot reach 5B (cross-cut test); without baking, the transferred pattern is too soft and easily scratched, making it unsuitable for subsequent printing, spraying, and other processes; after baking at 170℃ for 30 minutes to fully cure, the adhesion reaches 5B, and it can pass the boiling water test, with good resistance to yellowing.

[0045] Wide operating window: adaptable to glass surface temperature changes of ±10℃; high requirements for glass surface cleanliness; wide transfer pressure range (0.3-0.4MPa).

[0046] Adhesion test of finished product: There is basically no adhesion after transfer without baking, and the adhesion is 5B after baking at 170℃ for half an hour.

[0047] The adhesive film of the heat transfer adhesive of the present invention rapidly becomes molten at the transfer temperature (160-180℃), ensuring good flowability and wettability; when cooled to room temperature after transfer, the Tg rises to 70-80℃, providing sufficient hardness and scratch resistance; after final baking and complete curing, the Tg reaches 90-100℃, ensuring final durability and permanent adhesion.

[0048] Rapid wetting and spreading technology: Adding surface energy modifiers to make the contact angle of the adhesive on the glass surface <15°; controlling the viscosity at the transfer temperature to 500-1000cps to achieve complete spreading within 1 second.

[0049] In summary, the initial adhesion of the present invention transferred onto glass bottles (reaching 5B) facilitates subsequent construction and shortens the overall processing time of the product.

[0050] Application Example 2: Continuous transfer printing on flat glass The heat transfer adhesive of Example 1 of the present invention: After cleaning the flat glass, under normal room temperature conditions, the transfer temperature is 160℃, the pressure is 0.3MPa, and the production line speed is 4 meters / minute (traditional transfer printing line). Stacking and packaging can begin 3 minutes after transfer. The final product passed the QUV aging test for 600 hours without any peeling.

[0051] Comparison with commercially available heat transfer adhesive in Example 1: After cleaning the flat glass, under normal room temperature conditions, the transfer temperature is 180℃, the pressure is 0.3MPa, and the production line speed is 4 meters / minute (traditional transfer production line). The pattern is not complete after transfer, so the production line speed is reduced to 3 meters / minute. After transfer, it needs to be baked at 170℃ for 30 minutes before it can be stacked and packaged.

[0052] The final product passed the QUV aging test for 600 hours without any peeling.

Claims

1. A high-speed heat transfer adhesive for glass, characterized in that, The product comprises the following components by mass fraction: 12-18% acrylic-modified silicone resin, 6-10% chlorinated polyolefin resin, 8-13% acrylic-modified rosin resin, 2-6% thermoplastic polyurethane elastomer, 5-8% latent isocyanate curing agent, 0.3-1% organotin catalyst, 0.5-3% γ-aminopropyltriethoxysilane, 0.5-2% phosphate ester adhesion promoter, 0.5-1.5% nano silica, 0.5-1% polytetrafluoroethylene micro powder, 0.3-0.8% ultraviolet light absorber, 0.05-0.2% surface wetting agent, and the balance being solvent.

2. The high-speed heat transfer adhesive for glass according to claim 1, characterized in that, The product comprises the following components by mass fraction: 15% acrylic-modified silicone resin, 8% chlorinated polyolefin resin, 10% acrylic-modified rosin resin, 4% thermoplastic polyurethane elastomer, 6% latent isocyanate curing agent, 0.5% organotin catalyst, 0.8% γ-aminopropyltriethoxysilane, 1% phosphate ester adhesion promoter, 1% nano silica, 0.8% polytetrafluoroethylene micro powder, 0.5% ultraviolet light absorber, 0.1% surface wetting agent, and the balance being solvent.

3. The high-speed heat transfer adhesive for glass according to claim 1, characterized in that, The solvent consists of ethyl acetate, PMA, methylcyclohexane, and butyl acetate.

4. The high-speed heat transfer adhesive for glass according to claim 3, characterized in that, The mass ratio of ethyl acetate, PMA, methylcyclohexane, and butyl acetate is 12:5:23:

10.

5. The high-speed heat transfer adhesive for glass according to claim 1, characterized in that, The particle size of the nano-silica is 20-80 nm.

6. The high-speed heat transfer adhesive for glass according to any one of claims 1-5, characterized in that, The preparation method of the high-speed heat transfer adhesive for glass includes the following steps: Step 1: Add acrylic-modified silicone resin, chlorinated polyolefin resin, acrylic-modified rosin resin, and thermoplastic polyurethane elastomer to a reaction vessel and heat to 55-65℃. Add 50% solvent and stir for 30-50 minutes until completely dissolved. Cool down to 40℃ or below to obtain a resin mixture for later use. Step 2: Mix nano-silica with 1 / 3 of the remaining solvent and ultrasonically disperse for 10-30 minutes to obtain a uniform dispersion. Slowly add the dispersion to the resin mixture from Step 1. Then add the latent isocyanate curing agent and organotin catalyst. Stir for 5-15 minutes, then add γ-aminopropyltriethoxysilane, phosphate ester adhesion promoter, polytetrafluoroethylene micro powder, ultraviolet light absorber, surface wetting agent and all remaining solvent. Shear dispersion and filter with a filter bag to obtain high-speed heat transfer adhesive for glass.

7. The high-speed heat transfer adhesive for glass according to any one of claims 6, characterized in that, The shearing speed in step 2 is 5000 rpm, and the time is 10 minutes.

8. The high-speed heat transfer adhesive for glass according to any one of claims 6, characterized in that, The filter bag has a mesh size of 250.