Radiation-curable ultra-low peel force release film coating composition, coating and application

Abstract

The present invention relates to the technical field of radiation-curable materials, and in particular to a radiation-curable ultra-low peel force release film coating composition, a coating and a preparation method thereof. The coating composition comprises the following raw materials in parts by weight: 10-30 parts of non-functionalized polysiloxane, 40-60 parts of terminally acrylated free-radically polymerizable siloxane, 10-25 parts of side-chain acrylated free-radically polymerizable siloxane, and 5-20 parts of a photopolymerizable active monomer. The cured film prepared has simultaneously ultra-low peel force (below 5 g / 25 mm), high residual adhesiveness (above 92% at 70 degrees for 20 H), and good aging release force (below 10 g / 25 mm at 70 degrees for 48 hours), and is applicable to fields such as food packaging paper (baking and packaging), adhesive labels and adhesive tapes, and functional films, and is particularly applicable to the field of electronic-grade pressure-sensitive tapes. The preparation method of the coating is simple, there is no VOC emission during the preparation process, environmental pollution is avoided, and at the same time, the operation risk is reduced, and it has significant environmental protection advantages.

Description

Technical Field

[0001] The present invention relates to the technical field of radiation-curable materials, and particularly to a radiation-curable ultra-low peel force release film coating composition, a coating and a preparation method thereof. Background Art

[0002] The release film, also known as the isolation film, peeling film, separation film, etc., has various different names. Common release film products are surface-treated on the substrate, including coating with silicone release agent, fluorine release agent or plasma treatment, so that they have a light and stable release force for different viscous materials. It can be divided into light release release film, medium release release film, and heavy release release film according to the release force. Currently, the release force is generally between 5g and 2000g; in terms of structure, it can be divided into adhesive release film, composite release film, laser film, and non-adhesive release film; in terms of function, it can be divided into isolation release film, protection release film, waterproof release film, light diffusion release film, printing release film, tape release film. The release film has now been widely used in industries such as packaging, printing, screen printing, pad printing, nameplate, membrane switch, flexible circuit, insulation products, circuit board, laser anti-counterfeiting, lamination, electronics, film for sealing materials, reflective materials, waterproof materials, medicine (paper for medical paste), toilet paper, adhesive products, die-cutting and stamping processing.

[0003] The release film is mainly divided into two types according to the curing method: traditional thermal curing technology and modern radiation curing technology. The traditional thermal curing technology mainly has the following problems: 1. It needs to be cured at a relatively high temperature (above 100°C), with high energy consumption, long curing time and low efficiency; 2. The system has a relatively high viscosity, and a large amount of organic solvents need to be added for normal coating, and a large amount of organic solvents are generated during the production process, polluting the environment. Modern radiation curing refers to the processing process in which substances are rapidly transformed from a liquid state to a solid state through a photon source (such as ultraviolet light and gamma radiation) or an electron source (such as an electron beam). Radiation curing technology has the advantages of 5E: economical, efficient, environmental friendly, energy saving and wide applicability, and is more environmentally friendly and efficient than the traditional thermal curing technology. The commonly used radiation curing means in industry are mainly ultraviolet light (UV) curing and electron beam (EB) curing. Using high-efficiency energy as the initiation means, rapid curing of materials can be achieved. For example, UV curing means that under ultraviolet light irradiation, the photoinitiator in the system absorbs ultraviolet light to form excited state molecules, decomposes to generate active free radicals or ions, and these free radicals or ions further initiate the polymerization of unsaturated monomers and prepolymers, thereby instantly transforming the system from a low-viscosity liquid state into a solid material.

[0004] When preparing a release film in the prior art, due to the presence of polyfunctional acrylate groups or other types of unsaturated groups that can undergo free-radical polymerization in the system, the release force of the release film is relatively large, and it is impossible to prepare a release film with an ultra-low release force. Moreover, the UV curing system contains a photoinitiator, which does not participate in the polymerization reaction and is prone to cleavage to generate fragments, resulting in a decrease in residual adhesiveness and a deterioration of the release force during high-temperature aging.

[0005] Therefore, it is necessary to develop a radiation-curable release film coating composition with an ultra-low release force and a coating prepared based on this composition. Summary of the Invention

[0006] In view of the above problems existing in the prior art, the applicant of the present invention provides a radiation-curable release film coating composition with an ultra-low release force, a coating, and a preparation method thereof.

[0007] The radiation-curable release film coating composition of the present invention adopts a solvent-free electron beam (EB) curing technology, has no VOC emissions, and the formed cured film simultaneously has an ultra-low release force (below 5 g / 25 mm), a high residual adhesiveness (above 92% at 70 degrees for 20 hours), and a good aging release force (below 10 g / 25 mm at 70 degrees for 48 hours). It is applicable to fields such as food packaging paper (baking and packaging), adhesive labels and adhesive tapes, functional films, etc., and is particularly suitable for the field of electronic-grade pressure-sensitive tapes.

[0008] The first aspect of the present application is to provide a radiation-curable release film coating composition with an ultra-low release force.

[0009] The specific technical solution is as follows:

[0010] A radiation-curable release film coating composition with an ultra-low release force, comprising the following raw materials in parts by weight:

[0011] 10 - 30 parts of non-functionalized polysiloxane,

[0012] 40 - 60 parts of a silicon oxygen alkane modified with terminal acrylate and capable of free-radical polymerization,

[0013] 10 - 25 parts of a silicon oxygen alkane modified with side-chain acrylate and capable of free-radical polymerization,

[0014] 5 - 20 parts of a photo-polymerizable active monomer.

[0015] Furthermore, the non-functionalized polysiloxane has a straight-chain polysiloxane main chain and has aliphatic or aromatic substituents, and the structural formula is as shown in Formula 1:

[0016]

[0017] In Formula 1, R1, R2, R3, R4 and R5 are independently selected from alkyl groups and aryl groups, where m and n are integers, and m and n are not both zero at the same time.

[0018] Furthermore, the non-functionalized polysiloxane is a linear material with a siloxane backbone having aliphatic or aromatic substituents. In Formula 1, R1, R2, R3, R4 and R5 are independently selected from alkyl groups, where m and n are integers, and m and n are not both zero at the same time;

[0019] Furthermore, the non-functionalized polysiloxane is a linear material with a siloxane backbone having aliphatic or aromatic substituents. In Formula 1, R1, R2, R3, R4 and R5 are all methyl groups, where m and n are integers, and m and n are not both zero at the same time;

[0020] Furthermore, the non-functionalized polysiloxane is a fluid with an appropriate molecular weight, and its dynamic viscosity at 25 °C is 5000 mPa·s - 20000 mPa·s; 20000 mPa·s - 30000 mPa·s; 30000 mPa·s - 60000 mPa·s; 60000 mPa·s - 80000 mPa·s; 80000 mPa·s - 100000 mPa·s;

[0021] A fluid with an appropriate molecular weight is used to define the non-functionalized polysiloxane to ensure that its viscosity is within a certain range.

[0022] Furthermore, the non-functionalized polysiloxane is a fluid with an appropriate molecular weight, and its dynamic viscosity at 25 °C is 10000 mPa·s - 20000 mPa·s; 20000 mPa·s - 30000 mPa·s; 30000 mPa·s - 60000 mPa·s; 60000 mPa·s - 80000 mPa·s;

[0023] Furthermore, the non-functionalized polysiloxane is a fluid with an appropriate molecular weight, and its dynamic viscosity at 25 °C is 20000 mPa·s - 30000 mPa·s; 30000 mPa·s - 60000 mPa·s; 60000 mPa·s - 80000 mPa·s;

[0024] When the dynamic viscosity of the non-functionalized polysiloxane at 25 °C is lower than 5000 mPa·s, the coating after EB curing is not completely cured, fingerprints are generated, resulting in a decrease in residual adhesion and a poor release force during high-temperature aging; when the dynamic viscosity of the non-functionalized polysiloxane at 25 °C is greater than 100000 mPa·s, the system compatibility is poor and phase separation occurs, resulting in an orange peel-like appearance of the coating and unable to be tested normally;

[0025] In some embodiments, the non-functionalized polysiloxane is selected from one or more of PMX200-5000cst, PMX200-10000cst, PMX200-20000cst, PMX200-30000cst, PMX200-40000cst, PMX200-50000cst, PMX200-60000cst, PMX200-80000cst, PMX200-100000cst produced by Dow Corning;

[0026] Furthermore, the terminal acrylate-modified free-radically polymerizable siloxane contains no less than 2 acrylate groups;

[0027] Still further, the terminal acrylate-modified free-radically polymerizable siloxane is selected from one or a combination of TEGORC702, TEGO RC706, TEGO RC715, TEGO RC730, TEGO RC800, TEGO RC902, TEGO RC922 produced by Evonik, UV Poly 110, UV Poly 112 produced by Elkem, 4629 produced by Changxing, and KF-2005 produced by Shin-Etsu;

[0028] In some preferred embodiments, the terminal acrylate-modified free-radically polymerizable siloxane is preferably one or a combination of TEGO RC902 and TEGO RC922 produced by Evonik;

[0029] Furthermore, the side-chain acrylate-modified free-radically polymerizable siloxane contains more than 2 acrylate groups;

[0030] Still further, the side-chain acrylate-modified free-radically polymerizable siloxane is selected from one or a combination of TEGORC711, TEGO RC722 produced by Evonik, UV Poly 111 produced by Elkem, and 4659 produced by Changxing;

[0031] In some preferred embodiments, the side-chain acrylate-modified free-radically polymerizable siloxane is preferably one or two of TEGO RC711 and TEGO RC722 produced by Evonik;

[0032] Furthermore, the photo-polymerizable active monomer contains 2 or more and 6 or less acrylate groups;

[0033] Further, the photo-polymerizable active monomer is selected from one or more of 1,4-butanediol di(meth)acrylate, 1,6-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, neopentyl glycol hydroxytriacetate di(meth)acrylate, dicyclopentyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, propionate-modified dipentaerythritol penta(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(acryloyloxyethyl)isocyanurate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, propionate-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0034] The second aspect of the present application is to provide a preparation method for a radiation-curable low-peel-force release film coating composition, and the preparation method includes the following steps:

[0035] Mix 10 - 30 parts of non-functionalized polysiloxane, 40 - 60 parts of end-acrylate-modified free-radical polymerizable siloxane, 10 - 25 parts of side-chain acrylate-modified free-radical polymerizable siloxane, and 5 - 20 parts of photo-polymerizable active monomer, and stir and disperse them evenly to obtain the radiation-curable low-peel-force release film coating composition.

[0036] Further, the dispersion method uses a high-speed disperser;

[0037] Further, the rotation speed of the disperser is 1000 - 3000 rpm, and the dispersion time is 20 - 40 minutes; [[ID=1�]]

[0038] The third aspect of the present application is to provide a preparation method for a radiation-curable low-peel-force release film coating, using the coating composition described above or the coating composition prepared by the preparation method described above. The preparation method includes the following steps:

[0039] S11: First, coat the radiation-curable low-peel-force release film coating composition on a PET film with a wire bar to form a liquid coating with a thickness of 0.5 - 1.5 μm;

[0040] S12: Then, put the PET film coated with the liquid coating prepared in S11 into an electron beam curing device for radiation curing to obtain an ultra-low peel force release film coating.

[0041] In one embodiment, electron beam (EB) curing is used in step S12.

[0042] Furthermore, the EB curing conditions in step S12 are: voltage 50 KeV - 150 KeV, dose 20 KGy - 120 KGy.

[0043] The fourth aspect of the present application lies in providing an application of a film coating composition, which is characterized in that the coating composition can form a dry film and a cured product after EB curing, and is applied to the fields of preparing food packaging paper, adhesive labels and tapes, functional films, etc.; the food packaging paper includes but is not limited to baking paper and packaging paper.

[0044] The fifth aspect of the present application lies in providing an application of a radiation-cured ultra-low peel force release film coating, which is characterized in that it is applied to the preparation of electronic-grade pressure-sensitive tapes.

[0045] Advantageous effects:

[0046] The advantageous effects of the present application are as follows:

[0047] The radiation-cured ultra-low peel force release film coating composition provided by the present application has an ultra-low peel force (below 5 g / 25 mm), high residual adhesiveness (above 92% at 70 degrees for 20 hours), and good aging peel force (below 10 g / 25 mm at 70 degrees for 48 hours) for the cured film prepared. It is suitable for the fields of food packaging paper (baking and packaging), adhesive labels and tapes, functional films, etc., and is particularly suitable for the field of electronic-grade pressure-sensitive tapes.

[0048] The radiation-cured ultra-low peel force release film coating provided by the present application has a simple preparation method, no VOC emission during the preparation process, avoids environmental pollution, and also reduces operation risks, having significant environmental protection advantages.

[0049] The present invention uses non-functionalized polysiloxane as a raw material and prepares a release film with ultra-low peel force by electron beam curing, overcoming the defect that non-functionalized polysiloxane cannot participate in the reaction in conventional curing methods. Specific embodiments

[0050] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] Performance test method:

[0052] (1) Peel strength test

[0053] Testing instrument: Tensile tester or similar instrument, whose fixture can peel the pressure-sensitive material at 180°, with a peeling speed of 300 mm / min, accuracy of ±2%, and the test plate is made of stainless steel with a smooth surface. A standard pressure roller (2KG);

[0054] Test sample: It should be a test strip taken from a representative material, with a width of 25 mm; at least 200 mm long along the instrument direction, the incision is clean and straight, and at least 3 strips of each material should be taken for testing. The test tape uses TESA7475;

[0055] Test conditions: Temperature 23°C ± 2°C, 50% RH ± 5% RH;

[0056] Test procedure: Place the TESA7475 with the adhesive side down, and gently press with your finger to stick the tape to the clean test plate. Use the pressure roller to press back and forth 2 times at a speed of about 10 mm / second to make the adhesive surface closely contact with the test plate. After the test strip is properly pasted, wait for 20 minutes before testing. Adjust the peeling angle to 180°, set the speed to 300 mm / min, and start the machine to run the test;

[0057] Test result: The peel strength is expressed in g / 25mm, and the average value is taken for each test strip.

[0058] (2) Residual adhesive force test

[0059] Testing instrument: Tensile tester or similar instrument, whose fixture can peel the pressure-sensitive material at 180°, with a peeling speed of 300 mm / min, accuracy of ±2%, and the test plate is made of stainless steel with a smooth surface. A standard pressure roller (2KG);

[0060] Test sample: It should be a test strip taken from a representative material; at least 200 mm long along the instrument direction, the incision is clean and straight, and at least 3 strips of each material should be taken for testing. The test tape uses Nitto 31B;

[0061] Test conditions: Temperature 23°C ± 2°C, 50% RH ± 5% RH;

[0062] Test procedure:

[0063] 1. Stick the Nitto 31B tape with a width of 25 mm on the test sample, roll it back and forth 2 times with a 2KG pressure roller, then age it for 20 hours under the pressure of a 2 kg standard weight at 70°C, and then cool it for 0.5 - 2 hours at room temperature of 23 ± 2°C and relative humidity of 50%, and then perform 180° peeling at 300 mm / min. Each group of specimens should have no less than 3 strips;

[0064] 2. Reattach the Nitto 31B tape peeled off in Process 1 to the stainless steel plate, place it for 2 hours at a pressure of 2KG, room temperature of 23 ± 2°C, and relative humidity of 50%, and then perform a 180° peel at 300 mm / min. Take the average value and record it as L1;

[0065] 3. Attach the standard Nitto 31B tape to the stainless steel plate, roll it back and forth 2 times with a 2KG pressure roller, place it for 2 hours at a pressure of 2KG, room temperature of 23 ± 2°C, and relative humidity of 50%, and then perform a 180° peel at 300 mm / min. Take the average value and record it as L0;

[0066] Test result: L1 ÷ L0 × 100% is the residual adhesive force.

[0067] (3) Aging release force test

[0068] Testing instrument: Tensile tester or similar instrument, whose fixture can peel the pressure-sensitive material at 180°, the peeling speed is 300 mm / min, the accuracy is ±2%, and the test plate is made of stainless steel with a smooth surface. A standard pressure roller (2KG);

[0069] Test sample: It should be a test strip taken from a representative material, with a width of 25 mm; at least 200 mm long along the instrument direction, the cut is clean and straight, and at least 3 strips of each material should be taken for testing. The testing tape uses TESA7475;

[0070] Test conditions: Temperature 23°C ± 2°C, 50% RH ± 5% RH;

[0071] Test steps: Place the TESA7475 tape with the adhesive side down, and gently press it to attach the tape to the clean test plate. Roll the pressure roller back and forth 2 times at a speed of about 10 mm / second to make the adhesive side closely contact with the test plate. After the test strip is attached properly, age it for 48 hours under a pressure of a 2-kilogram standard weight at a temperature of 70°C, and then cool it for 0.5 - 2 hours at room temperature of 23 ± 2°C and relative humidity of 50% before testing. Adjust the peeling angle to 180°, set the speed to 300 mm / min, and start the machine to run the test;

[0072] Test result: The aging release force is expressed in g / 25mm, and the average value is taken for each test strip.

[0073] The present invention will be specifically described below. The raw materials and their dosages used in each embodiment are shown in Table 1.

[0074] Table 1 Component ratios of each embodiment

[0075]

[0076] Example 1

[0077] A preparation method of a radiation-curable low peel force release film coating composition, the preparation method comprising the following steps:

[0078] Mix 10 parts of non-functionalized polysiloxane (PMX200 - 30000cst produced by Dow Corning), 60 parts of end-acrylate modified free-radical polymerizable siloxane (TEGO RC922 produced by Evonik), 25 parts of side-chain acrylate modified free-radical polymerizable siloxane (TEGO RC722 produced by Evonik), and 5 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes; to obtain the radiation-curable low peel force release film coating composition.

[0079] A preparation method of a radiation-curable low peel force release film coating comprises the following steps:

[0080] S11: First, coat the radiation-curable low peel force release film coating composition on a PET film with a wire bar to form a liquid coating with a thickness of 0.8 μm;

[0081] S12: Then, put the PET film with the liquid coating into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 40 KGy), thereby obtaining the radiation-curable low peel force release film coating.

[0082] Example 2

[0083] A preparation method of a radiation-curable low peel force release film coating composition, the preparation method comprising the following steps:

[0084] Mix 20 parts of non-functionalized polysiloxane (PMX200 - 30000cst produced by Dow Corning), 50 parts of end-acrylate modified free-radical polymerizable siloxane (TEGO RC922 produced by Evonik), 20 parts of side-chain acrylate modified free-radical polymerizable siloxane (TEGO RC722 produced by Evonik), and 10 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes; to obtain the radiation-curable low peel force release film coating composition.

[0085] A preparation method of a radiation-curable low peel force release film coating comprises the following steps:

[0086] S11: First, coat the radiation-curable low peel force release film coating composition on a PET film with a wire bar to form a liquid coating with a thickness of 0.8 um;

[0087] S12: Then, place the PET film with the liquid coating into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 50 KGy) to obtain a radiation-cured low peel force release film coating.

[0088] Example 3

[0089] A preparation method of a radiation-cured low peel force release film coating composition, the preparation method comprising the following steps:

[0090] Mix 30 parts of non-functionalized polysiloxane (PMX200 - 30000 cst produced by Dow Corning), 40 parts of end acrylate-modified free-radical polymerizable siloxane (TEGO RC902 produced by Evonik), 10 parts of side-chain acrylate-modified free-radical polymerizable siloxane (TEGO RC711 produced by Evonik), and 20 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes to obtain the radiation-cured low peel force release film coating composition.

[0091] A preparation method of a radiation-cured low peel force release film coating comprises the following steps:

[0092] S11: First, coat the radiation-cured low peel force release film coating composition on the PET film with a wire bar to form a liquid coating with a thickness of 0.8 um;

[0093] S12: Then, place the PET film with the liquid coating into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 KGy) to obtain a radiation-cured low peel force release film coating.

[0094] Example 4

[0095] A preparation method of a radiation-cured low peel force release film coating composition, the preparation method comprising the following steps:

[0096] Mix 10 parts of non-functionalized polysiloxane (PMX200 - 80000 cst produced by Dow Corning), 60 parts of end acrylate-modified free-radical polymerizable siloxane (TEGO RC902 produced by Evonik), 20 parts of side-chain acrylate-modified free-radical polymerizable siloxane (TEGO RC711 produced by Evonik), and 10 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes to obtain the radiation-cured low peel force release film coating composition.

[0097] A preparation method of a radiation-cured low peel force release film coating comprises the following steps:

[0098] S11: First, use a wire bar to coat the radiation-curable ultra-low peel force release film coating composition on a PET film to form a liquid coating with a thickness of 0.8 μm.

[0099] S12: Then, place the PET film with the liquid coating into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 kGy) to obtain a radiation-curable ultra-low peel force release film coating.

[0100] Example 5

[0101] A preparation method of a radiation-curable ultra-low peel force release film coating composition, the preparation method comprising the following steps:

[0102] Mix 10 parts of non-functionalized polysiloxane (PMX200 - 60000 cst produced by Dow Corning), 60 parts of end-acrylate modified free-radical polymerizable siloxane (TEGO RC902 produced by Evonik), 20 parts of side-chain acrylate modified free-radical polymerizable siloxane (TEGO RC711 produced by Evonik), and 10 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes; to obtain the radiation-curable ultra-low peel force release film coating composition.

[0103] A preparation method of a radiation-curable ultra-low peel force release film coating comprises the following steps:

[0104] S11: First, use a wire bar to coat the radiation-curable ultra-low peel force release film coating composition on a PET film to form a liquid coating with a thickness of 0.8 μm.

[0105] S12: Then, place the PET film with the liquid coating into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 kGy) to obtain a radiation-curable ultra-low peel force release film coating.

[0106] Example 6

[0107] A preparation method of a radiation-curable ultra-low peel force release film coating composition, the preparation method comprising the following steps:

[0108] Thirty parts of non-functionalized polysiloxane (PMX200 - 20000cst produced by Dow Corning), forty parts of end-acrylate-modified free-radical polymerizable siloxane (TEGO RC902 produced by Evonik), twenty parts of side-chain acrylate-modified free-radical polymerizable siloxane (TEGO RC711 produced by Evonik), and ten parts of photo-polymerizable active monomer mixture (TMPTA) were stirred and dispersed at a speed of 2000 rpm for 30 minutes using a disperser; the radiation-curable ultra-low peel force release film coating composition was prepared.

[0109] A preparation method of a radiation-curable ultra-low peel force release film coating comprises the following steps:

[0110] S11: First, the radiation-curable ultra-low peel force release film coating composition was coated on a PET film using a wire bar to form a liquid coating with a thickness of 0.8 μm.

[0111] S12: Then, the PET film with the liquid coating was put into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 kGy), thereby obtaining the radiation-curable ultra-low peel force release film coating.

[0112] Comparative Example 1

[0113] A preparation method of a radiation-curable ultra-low peel force release film coating composition, the preparation method comprises the following steps:

[0114] Five parts of non-functionalized polysiloxane (PMX200 - 30000cst produced by Dow Corning), sixty-five parts of end-acrylate-modified free-radical polymerizable siloxane (TEGO RC922 produced by Evonik), twenty parts of side-chain acrylate-modified free-radical polymerizable siloxane (TEGO RC722 produced by Evonik), and ten parts of photo-polymerizable active monomer mixture (TMPTA) were stirred and dispersed at a speed of 2000 rpm for 30 minutes using a disperser; the radiation-curable ultra-low peel force release film coating composition was prepared.

[0115] A preparation method of a radiation-curable ultra-low peel force release film coating comprises the following steps:

[0116] S11: First, the radiation-curable ultra-low peel force release film coating composition was coated on a PET film using a wire bar to form a liquid coating with a thickness of 0.8 μm.

[0117] S12: Then, the PET film with the liquid coating was put into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 kGy), thereby obtaining the radiation-curable ultra-low peel force release film coating.

[0118] Comparative Example 2

[0119] A preparation method of a radiation-curable ultra-low peel force release film coating composition, the preparation method comprising the following steps:

[0120] Mix 40 parts of non-functionalized polysiloxane (PMX200-30000cst produced by Dow Corning), 30 parts of end-acrylate modified free-radical polymerizable siloxane (TEGO RC902 produced by Evonik), 20 parts of side-chain acrylate modified free-radical polymerizable siloxane (TEGO RC711 produced by Evonik), and 10 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes; to obtain the radiation-curable ultra-low peel force release film coating composition.

[0121] A preparation method of a radiation-curable ultra-low peel force release film coating comprises the following steps:

[0122] S11: First, coat the radiation-curable ultra-low peel force release film coating composition on a PET base film with a wire bar to form a liquid coating with a thickness of 0.8 um;

[0123] S12: Then put the PET film with the liquid coating into an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 KGy), thereby obtaining a radiation-curable ultra-low peel force release film coating.

[0124] Comparative Example 3

[0125] A preparation method of a radiation-curable ultra-low peel force release film coating composition, the preparation method comprising the following steps:

[0126] Mix 20 parts of non-functionalized polysiloxane (PMX200-1000cst produced by Dow Corning), 50 parts of end-acrylate modified free-radical polymerizable siloxane (TEGO RC922 produced by Evonik), 20 parts of side-chain acrylate modified free-radical polymerizable siloxane (TEGO RC722 produced by Evonik), and 10 parts of a photo-polymerizable active monomer (TMPTA), and stir and disperse with a disperser at a rotation speed of 2000 rpm for 30 minutes; to obtain the radiation-curable ultra-low peel force release film coating composition.

[0127] A preparation method of a radiation-curable ultra-low peel force release film coating comprises the following steps:

[0128] S11: First, coat the radiation-curable ultra-low peel force release film coating composition on a PET film with a wire bar to form a liquid coating with a thickness of 0.8 um;

[0129] S12: The PET film containing the liquid coating is then placed in an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 KGy), thereby preparing a radiation-cured ultra-low peel force release film coating.

[0130] Comparative Example 4

[0131] A method for preparing a radiation-curable ultra-low peel force release film coating composition, the preparation method comprising the following steps:

[0132] 20 parts of non-functionalized polysiloxane (PMX200-200000cst produced by Dow Corning), 50 parts of terminal acrylate-modified free radical polymerizable siloxane (TEGO RC902 produced by Evonik), 20 parts of side chain acrylate-modified free radical polymerizable siloxane (TEGO RC711 produced by Evonik), and 10 parts of photopolymerizable monomer (TMPTA) were mixed and stirred and dispersed at a speed of 2000 rpm for 30 minutes using a disperser to prepare the radiation-curable ultra-low peel force release film coating composition.

[0133] A method for preparing a radiation-cured ultra-low peel force release film coating comprises the following steps:

[0134] S11: First, a radiation-curable ultra-low peel force release film coating composition is coated on a PET film using a wire rod to form a liquid coating with a thickness of 0.8 μm;

[0135] S12: The PET film containing the liquid coating is then placed in an electron beam (EB) curing device for radiation curing (EB curing conditions: voltage 110 KeV, dose 60 KGy), thereby preparing a radiation-cured ultra-low peel force release film coating.

[0136] Performance test results:

[0137] The film coatings obtained in Examples 1 to 6 of the present invention and Comparative Examples 1 to 4 were tested for peel strength, residual adhesion, and aged release strength. The test results are shown in Table 2.

[0138] Table 2

[0139]

[0140] From the test results in Table 2, we can see that:

[0141] The film coatings prepared in Examples 1 to 6 of the present invention have a peel force of 1.5-4.3 g / 25 mm, a residual adhesion of more than 93%, and an aged release force of 5.9-8.9 g / 25 mm. They have ultra-low peel force, high residual adhesion, and good aged release force, and are particularly suitable for the field of electronic-grade pressure-sensitive tapes. The preparation process has no VOC emissions, is energy-saving and environmentally friendly.

[0142] However, the performance of the thin film coatings prepared in Comparative Examples 1-4 could not meet the requirements. Among them, the thin film coating prepared in Comparative Example 1 had high residual adhesion and good aging release force, but the peel force was relatively high. The reason was that the addition amount of non-functionalized polysiloxane was too small to achieve the effect of reducing the peel force and could not meet the requirements in the field of electronic adhesive pressure-sensitive tapes.

[0143] The thin film coating prepared in Comparative Example 2 had an ultra-low peel force, but the residual adhesion and aging release force were poor. The reason was that the addition amount of non-functionalized polysiloxane was too large, resulting in insufficient curing crosslinking degree, which easily caused the performance degradation of the pressure-sensitive adhesive and thus could not meet the requirements in the field of electronic adhesive pressure-sensitive tapes.

[0144] For the thin film coating prepared in Comparative Example 3, due to the too low molecular weight of the non-functionalized polysiloxane, it could not undergo a complete crosslinking reaction under EB curing conditions, the coating was not completely cured, fingerprints were generated, resulting in poor performance in all aspects.

[0145] For the thin film coating prepared in Comparative Example 4, due to the too high molecular weight of the non-functionalized polysiloxane, the system compatibility was poor and phase separation occurred, resulting in an orange peel-like appearance of the coating and too large fluctuations in the test values, and it could not meet the basic requirements of the release film.

[0146] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various modifications and decorations without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims

1. A radiation-curable ultra-low peel force release film coating composition, characterized in that: The raw materials include the following parts by weight: 10-30 parts of non-functional polysiloxane, 40-60 parts of terminal acrylate-modified free radical polymerizable siloxane, 10-25 parts of side chain acrylate modified free radical polymerizable siloxane, 5-20 parts of photopolymerizable monomer; in: The non-functionalized polysiloxane is Dow Corning PMX200, and has a dynamic viscosity of 20,000-80,000 mPa·s at 25°C; The terminal acrylate-modified free radical polymerizable siloxane is selected from TEGO RC902 or TEGO RC922; The side chain acrylate modified free radical polymerizable siloxane is selected from TEGO RC711 or TEGO RC722; The photopolymerizable active monomer is trimethylolpropane triacrylate.

2. The method for preparing the radiation-curable ultra-low peeling force release film coating composition according to claim 1, characterized in that: The steps include: 10-30 parts of non-functionalized polysiloxane, 40-60 parts of terminal acrylate-modified free radical polymerizable siloxane, 10-25 parts of side chain acrylate-modified free radical polymerizable siloxane, and 5-20 parts of photopolymerizable active monomer are mixed and stirred to uniformly disperse; the radiation-curable ultra-low peel force release film coating composition is prepared.

3. A method for preparing a radiation-cured ultra-low peel force release film coating, characterized in that: A coating composition prepared using the coating composition according to claim 1 or the coating composition prepared by the preparation method according to claim 2; The preparation method of the release film coating comprises the following steps: S11: First, a radiation-curable ultra-low peel force release film coating composition is coated on a PET film using a wire rod to form a liquid coating having a thickness of 0.5 to 1.5 μm; S12: The PET film coated with the liquid coating obtained in S11 is then placed in an electron beam curing device for radiation curing to obtain an ultra-low peeling force release film coating.

4. The method for preparing a radiation-cured ultra-low peel force release film coating according to claim 3, wherein: The electron beam curing condition in step S12 is a voltage of 50 KeV-150 KeV.

5. The method for preparing a radiation-curable ultra-low peel force release film coating according to claim 4, wherein: The electron beam curing condition in step S12 is a dose of 20 KGy to 120 KGy.

6. Use of the coating composition according to claim 1, or the coating composition prepared by the preparation method according to claim 2, characterized in that: After curing to form a dry film, it can be used to prepare food paper, adhesive labels and adhesive tapes.

7. Application of the coating prepared by the preparation method according to claim 3, characterized in that: Used in the preparation of electronic grade pressure-sensitive tape.

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