Preparation process of light-cured organic silicon release film

Abstract

The invention relates to the technical field of release films, in particular to a preparation process of a light-cured organic silicon release film, which comprises the following steps: S1, mixing and uniformly stirring natural organic silicon powder, 2-hydroxyethyl methacrylate, a flatting agent, an organic photocatalyst and an initiator to obtain an organic silicon release agent; and S2, uniformly coating a PET substrate with the organic silicon release agent prepared in the step S1 according to a certain thickness, and curing under the irradiation of visible light to obtain the release film. 2-hydroxyethyl methacrylate (HEMA) contains active double bonds and hydroxyl functional groups, silicon hydroxyl (S i-OH) is arranged on the surface of the porous organic silicon material, free radical polymerization reaction can be carried out by the aid of the double bonds of HEMA, and crosslinking is realized by the aid of condensation reaction of the hydroxyl of HEMA and hydroxyl on the surface of organic silicon. The chemical bonds are not easy to break in an acid-base environment, so that the structural integrity of the material is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of release films, and in particular to a preparation process of a photocurable organic silicon release film. Background Art

[0002] Release films can be divided into BOPET release films, BOPP release films, PE release films, other organic material release films and special purpose release films according to the selected base materials. BOPET is widely used due to its good heat resistance, high mechanical strength, good surface flatness and high bonding strength with release agents. The release agents currently used are: silicone release agents, fluorine-containing release agents and silicate release agents. Silicone release agents have the advantages of good transparency, good isolation effect, high temperature resistance, solvent resistance, adjustable coating thickness and silicon content, good durability and reusability. However, the surface tension of the release film formed by silicone coating is too low to meet the requirements of special occasions. At present, the main method is to modify silicone to increase the surface tension of the release film, but while increasing the surface tension, the peeling force will also increase, and as a release material, it must have a relatively low peeling force.

[0003] Among the preparation methods of release films, photocuring technology has attracted widespread attention due to its advantages of low solvent release (low VOC), fast curing speed, easy control of curing area and curing degree, and good production continuity. Compared with traditional thermal curing technology, energy saving and environmental protection are its most prominent advantages, and it is also a technology that conforms to the direction of industrial development. Ultraviolet light has higher energy and is the first choice for photocuring, but ultraviolet light has higher hazards and a long curing process. Visible light curing is a relatively safer technology, but it places higher requirements on photocatalytic materials. In photocuring, the catalysts currently used more are metal materials. For example, Chinese patent CN107915790A discloses a method for preparing a visible light-cured release film, using a catalyst containing precious metals (facial tris (2-phenylpyridine) iridium). The use of precious metal materials greatly increases the production cost; in addition, the introduction of metals in the release film will also have an adverse effect on subsequent applications. The addition of natural porous silicone can avoid the introduction of metal and contamination of the release film, eliminate the need for additional purification procedures, simplify the production process, and at the same time have the functions of high temperature resistance and antioxidant properties. Therefore, there is an urgent need to develop an economical and environmentally friendly light-curing silicone release film that can be used in acidic and alkaline environments. Summary of the invention

[0004] In order to solve the problems mentioned in the above background technology, the present invention provides a preparation process of a photocurable silicone release film.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A preparation process of a light-curable silicone release film comprises the following steps:

[0007] S1, mixing natural silicone powder, 2-hydroxyethyl methacrylate, a leveling agent, an organic photocatalyst, and an initiator and stirring them uniformly to obtain a silicone release agent;

[0008] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a certain thickness, and cured under the irradiation of visible light to obtain a release film.

[0009] Preferably, the mass ratio of the natural silicone powder, 2-hydroxyethyl methacrylate, leveling agent, organic photocatalyst and initiator is (50-70): (10-15): (0-2): (0.1-0.15): (0.3-0.5).

[0010] Preferably, the method for preparing the natural porous organosilicon powder comprises the following steps:

[0011] S1. By weight, 40-50 parts of foxtail grass, 1-2 parts of cellulase, and a concentration of (3-5)×10 11 CFU / g of Bacillus subtilis 1-3 parts and ammonium nitrate 4-6 parts are prepared into a mixture;

[0012] S2, the mixture is fermented in a fermentation tank at 32-36°C for 5-6 hours to prepare a fermentation mixture, 30-35 parts of a 20-25% sodium carbonate solution are added to the fermentation mixture, and the mixture is soaked for 5-8 hours at a temperature of 85-95°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0013] S3, the mixed extract is calcined in a sintering furnace in an inert gas and oxygen-free environment, compounded, and sintered in three stages to obtain natural organic silicon powder;

[0014] S4. Mix γ-aminopropyltriethoxysilane with natural organic silicon powder and 95% ethanol solution in a mass ratio of 10:(3-5):(8-11), and at 85-100°C for 3-4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0015] The ethoxy group of γ-aminopropyltriethoxysilane undergoes a hydrolysis condensation reaction with the hydroxyl group on the surface of the silicon powder, introducing the organic functional group amino group into the surface of the silicon powder, making it more compatible with organic materials, while also being able to maintain its porous structure to a certain extent.

[0016] Preferably, the natural organic silicon powder is crushed to nanometer scale, with an average particle size of 35-55nm and an average specific surface area of ​​90-100m 2 / g.

[0017] Preferably, the conditions for the three-stage sintering are:

[0018] The sintering conditions in the first stage are controlled as follows: heating to 780-810°C at a heating rate of 1-5°C / min, keeping the temperature for 4-5h, and obtaining preform I;

[0019] The sintering conditions of the second stage are controlled as follows: heating the preform I to 960-1010°C at a heating rate of 5-10°C / min, and keeping the temperature for 5-6h to obtain the preform II;

[0020] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800-820°C at a cooling rate of 1-3°C / min, and keeping the temperature for 5-6 hours to obtain natural organic silicon powder.

[0021] Preferably, the organic photocatalyst is 9-thioxanthone and / or N-methylacridone.

[0022] Preferably, the initiator is one or more of tert-butyl hydroperoxide, 2,2-azobisisobutyronitrile and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0023] Preferably, the wavelength of the visible light is ≥450 nm, the ambient temperature of the curing reaction is 35-50° C., and the reaction time is 3-8 hours.

[0024] Preferably, the thickness of the silicone release agent coated on the PET substrate is 30-50 μm.

[0025] Preferably, the leveling agent is selected from one or more of BYK331, EFKA3883, EFKA3600, and BYK366.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention prepares a visible light organic silicone release agent by mixing natural organic silicon powder, 2-hydroxyethyl methacrylate, a leveling agent, an organic photocatalyst and an initiator in a mass ratio of (50-70): (10-15): (0-2): (0.1-0.15): (0.3-0.5), thereby avoiding the introduction of metal elements, greatly expanding subsequent application fields and reducing production costs.

[0028] 2. In the present invention, 2-hydroxyethyl methacrylate (HEMA) contains active double bonds and hydroxyl functional groups, and the porous silicone material has silanol groups (Si-OH) on its surface. The double bonds of HEMA can be used for free radical polymerization, and its hydroxyl groups can be used for condensation reaction with hydroxyl groups on the silicone surface to achieve crosslinking.

[0029] For the free radical polymerization part, the initiator decomposes to generate free radicals, which trigger the double bonds of HEMA to open and undergo polymerization; the condensation reaction can be carried out under acidic or alkaline conditions to form silicon-oxygen bonds (SiOSi), thereby connecting HEMA to porous silicone. These chemical bonds are not easily broken in acidic or alkaline environments, thus ensuring the structural integrity of the material.

[0030] The cross-linked HEMA forms a continuous organic polymer protective layer on the surface of the porous silicone. This protective layer can block the direct contact between the acid and alkali solutions and the porous silicone, reducing the erosion of the silicone material by acids and alkalis.

[0031] 3. The stock solution of natural silicone powder in the present invention is derived from the herbaceous plant foxtail grass, which is biodegradable and has excellent high temperature resistance. It can improve the heat resistance of the release film and keep stable performance in high temperature environment. Secondly, the pores of natural silicone powder are easily penetrated and corroded by acid and alkali solutions. The cross-linked HEMA fills part of the pores, reduces the exposure of the pores, reduces the diffusion rate of the acid and alkali solutions in the pores, and further enhances the acid and alkali resistance of the release film, thereby extending its service life. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market. Among them, 2-hydroxyethyl methacrylate was purchased from Alibaba, Shouguang Lisheng Chemical Co., Ltd., CAS No.: 868-77-9;

[0034] 9-Thioxanthone was purchased from Aladdin, CAS number: 492-22-8;

[0035] N-methylacridone was purchased from Dingxiangtong, with the product number: YJ-1030661;

[0036] 2,2-Azobisisobutyronitrile was purchased from Aladdin, CAS number: 78-67-1;

[0037] Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide was purchased from Aladdin, CAS number: 162881-26-7.

[0038] Cellulase: The enzyme activity parameter is 100,000 U / g.

[0039] Preparation Example 1

[0040] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0041] S1, 40g of foxtail grass, 1g of cellulase, and 3×10 11 CFU / g of Bacillus subtilis 2g and ammonium nitrate 4g were used to prepare a mixture;

[0042] S2, the mixture is aerobically fermented in a fermentation tank at 32°C for 6 hours to prepare a fermentation mixture, 30g of 20% sodium carbonate solution (50mL) is added to the fermentation mixture, and the mixture is soaked for 7 hours at a temperature of 85°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0043] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0044] S4. Mix 10 g of γ-aminopropyltriethoxysilane, 5 g of natural organic silicon powder and 11 g of 95% ethanol solution. At 85°C and a reaction time of 3 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo a hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0045] The conditions of the three-stage sintering are:

[0046] The sintering conditions in the first stage were controlled as follows: heating to 780°C at a heating rate of 1°C / min and keeping at that temperature for 4 h to obtain preform I;

[0047] The sintering conditions of the second stage are as follows: preform I is heated to 960°C at a heating rate of 5°C / min and kept at this temperature for 5h to obtain preform II;

[0048] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800°C at a cooling rate of 1°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0049] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 35nm and an average specific surface area of ​​100m 2 / g.

[0050] Preparation Example 2

[0051] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0052] S1, 42g of foxtail grass, 1.5g of cellulase, and 3×10 11 CFU / g of Bacillus subtilis 1g and ammonium nitrate 4g were used to prepare a mixture;

[0053] S2, the mixture is fermented in a fermentation tank at 33°C for 6 hours to prepare a fermentation mixture, 30g of a 20% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 7 hours at a temperature of 85°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0054] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0055] S4. Mix 10 g of γ-aminopropyltriethoxysilane, 5 g of natural organic silicon powder and 11 g of 95% ethanol solution. At 85°C and a reaction time of 4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo a hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0056] The conditions of the three-stage sintering are:

[0057] The sintering conditions in the first stage were controlled as follows: heating to 780°C at a heating rate of 1°C / min and keeping at that temperature for 4 h to obtain preform I;

[0058] The sintering conditions of the second stage are as follows: preform I is heated to 960°C at a heating rate of 5°C / min and kept at this temperature for 5h to obtain preform II;

[0059] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800°C at a cooling rate of 1°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0060] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 35nm and an average specific surface area of ​​100m 2 / g.

[0061] Preparation Example 3

[0062] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0063] S1, 45g of foxtail grass, 1.5g of cellulase, and 3×10 11 CFU / g of Bacillus subtilis 2g and ammonium nitrate 5g were used to prepare a mixture;

[0064] S2, the mixture is fermented in a fermentation tank at 35°C for 6 hours to prepare a fermentation mixture, 30g of 25% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 7 hours at a temperature of 85°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0065] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0066] S4. Mix 10 g of γ-aminopropyltriethoxysilane, 5 g of natural organic silicon powder and 11 g of 95% ethanol solution. At 90° C. and a reaction time of 4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo a hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0067] The conditions of the three-stage sintering are:

[0068] The sintering conditions in the first stage were controlled as follows: heating to 780°C at a heating rate of 1°C / min and keeping at that temperature for 4 h to obtain preform I;

[0069] The sintering conditions of the second stage are as follows: preform I is heated to 960°C at a heating rate of 5°C / min and kept at this temperature for 5h to obtain preform II;

[0070] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800°C at a cooling rate of 1°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0071] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 35nm and an average specific surface area of ​​100m 2 / g.

[0072] Preparation Example 4

[0073] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0074] S1, 46g of foxtail grass, 2g of cellulase, and 3×10 11 CFU / g of Bacillus subtilis 3g and ammonium nitrate 5g were used to prepare a mixture;

[0075] S2, the mixture is fermented in a fermentation tank at 35°C for 6 hours to prepare a fermentation mixture, 32g of a 23% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 7 hours at a temperature of 90°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0076] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0077] S4. Mix 10 g of γ-aminopropyltriethoxysilane, 4 g of natural organic silicon powder and 10 g of 95% ethanol solution. At 90° C. and for 3 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0078] The conditions of the three-stage sintering are:

[0079] The sintering conditions in the first stage were controlled as follows: heating to 800°C at a heating rate of 2°C / min and keeping at that temperature for 5 h to obtain preform I;

[0080] The sintering conditions of the second stage are as follows: preform I is heated to 1000°C at a heating rate of 8°C / min and kept at this temperature for 5 h to obtain preform II;

[0081] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 810°C at a cooling rate of 2°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0082] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 45nm and an average specific surface area of ​​95m 2 / g.

[0083] Preparation Example 5

[0084] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0085] S1, 46g of foxtail grass, 2g of cellulase, and 4×10 11 CFU / g of Bacillus subtilis 3g and ammonium nitrate 5g were used to prepare a mixture;

[0086] S2, the mixture is fermented in a fermentation tank at 35°C for 6 hours to prepare a fermentation mixture, 32g of 25% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 8 hours at a temperature of 90°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0087] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0088] S4. Mix 10 g of γ-aminopropyltriethoxysilane, 4 g of natural organic silicon powder and 10 g of 95% ethanol solution. At 95° C. and for 4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0089] The conditions of the three-stage sintering are:

[0090] The sintering conditions in the first stage were controlled as follows: heating to 800°C at a heating rate of 2°C / min and keeping at that temperature for 5 h to obtain preform I;

[0091] The sintering conditions of the second stage are as follows: preform I is heated to 1000°C at a heating rate of 8°C / min and kept at this temperature for 5 h to obtain preform II;

[0092] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 810°C at a cooling rate of 2°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0093] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 45nm and an average specific surface area of ​​95m 2 / g.

[0094] Preparation Example 6

[0095] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0096] S1, 48g of foxtail grass, 2g of cellulase, and 3×10 11 CFU / g of Bacillus subtilis 3g and ammonium nitrate 6g were used to prepare a mixture;

[0097] S2, the mixture is fermented in a fermentation tank at 35°C for 6 hours to prepare a fermentation mixture, 32g of 25% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 8 hours at a temperature of 90°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0098] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0099] S4. Mix 10 g of γ-aminopropyltriethoxysilane, 4 g of natural organic silicon powder and 10 g of 95% ethanol solution. At 95° C. and for 3 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0100] The conditions of the three-stage sintering are:

[0101] The sintering conditions in the first stage were controlled as follows: heating to 800°C at a heating rate of 2°C / min and keeping at that temperature for 5 h to obtain preform I;

[0102] The sintering conditions of the second stage are as follows: preform I is heated to 1000°C at a heating rate of 8°C / min and kept at this temperature for 5 h to obtain preform II;

[0103] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 810°C at a cooling rate of 2°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0104] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 45nm and an average specific surface area of ​​95m 2 / g.

[0105] Preparation Example 7

[0106] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0107] S1, 50g of foxtail grass, 2g of cellulase, and 5×10 11 CFU / g of Bacillus subtilis 3g and ammonium nitrate 6g were used to prepare a mixture;

[0108] S2, the mixture is fermented in a fermentation tank at 36°C for 6 hours to prepare a fermentation mixture, 35g of a 25% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 8 hours at a temperature of 95°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0109] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0110] S4. Mix 10 g of γ-aminopropyltriethoxysilane with 3 g of natural organic silicon powder and 8 g of 95% ethanol solution. At 100° C. and a reaction time of 3 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo a hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0111] The conditions of the three-stage sintering are:

[0112] The sintering conditions in the first stage were controlled as follows: heating to 780°C at a heating rate of 2°C / min and keeping the temperature for 4 h to obtain preform I;

[0113] The sintering conditions of the second stage are as follows: preform I is heated to 980°C at a heating rate of 5°C / min and kept at this temperature for 5h to obtain preform II;

[0114] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800°C at a cooling rate of 1°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0115] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 45nm and an average specific surface area of ​​95m 2 / g.

[0116] Preparation Example 8

[0117] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0118] S1, 50g of foxtail grass, 2g of cellulase, and 5×10 11 CFU / g of Bacillus subtilis 3g and ammonium nitrate 6g were used to prepare a mixture;

[0119] S2, the mixture is fermented in a fermentation tank at 36°C for 6 hours to prepare a fermentation mixture, 35g of a 25% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 8 hours at a temperature of 95°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0120] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0121] S4. Mix 10 g of γ-aminopropyltriethoxysilane with 3 g of natural organic silicon powder and 8 g of 95% ethanol solution. At 100° C. and a reaction time of 4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo a hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0122] The conditions of the three-stage sintering are:

[0123] The sintering conditions in the first stage were controlled as follows: heating to 780°C at a heating rate of 3°C / min and keeping at that temperature for 4h to obtain preform I;

[0124] The sintering conditions of the second stage are as follows: preform I is heated to 980°C at a heating rate of 5°C / min and kept at this temperature for 5h to obtain preform II;

[0125] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 810°C at a cooling rate of 2°C / min and keeping the temperature for 5 hours to obtain natural organosilicon powder.

[0126] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 46nm and an average specific surface area of ​​94m 2 / g.

[0127] Preparation Example 9

[0128] The method for preparing the natural porous organosilicon powder comprises the following steps:

[0129] S1, 50g of foxtail grass, 2g of cellulase, and 5×10 11 CFU / g of Bacillus subtilis 3g and ammonium nitrate 6g were used to prepare a mixture;

[0130] S2, the mixture is fermented in a fermentation tank at 36°C for 6 hours to prepare a fermentation mixture, 35g of a 25% sodium carbonate solution is added to the fermentation mixture, and the mixture is soaked for 8 hours at a temperature of 95°C. After the soaking, the mixture is filtered to obtain a mixed extract;

[0131] S3, calcining the mixed extract in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, compounding, and adopting a three-stage sintering method to obtain natural organic silicon powder;

[0132] S4. Mix 10 g of γ-aminopropyltriethoxysilane with 3 g of natural organic silicon powder and 8 g of 95% ethanol solution. At 100° C. and a reaction time of 4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo a hydrolysis condensation reaction to obtain natural porous organic silicon powder.

[0133] The conditions of the three-stage sintering are:

[0134] The sintering conditions in the first stage were controlled as follows: heating to 790°C at a heating rate of 5°C / min and keeping at that temperature for 4h to obtain preform I;

[0135] The sintering conditions of the second stage are as follows: preform I is heated to 1010°C at a heating rate of 10°C / min and kept at this temperature for 5h to obtain preform II;

[0136] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 810°C at a cooling rate of 3°C / min and keeping the temperature for 5 hours to obtain natural organic silicon powder.

[0137] The natural organic silicon powder is crushed to nanometer level, with an average particle size of 46nm and an average specific surface area of ​​94m 2 / g.

[0138] Comparative Preparation Example 1

[0139] The difference between this comparative preparation example and preparation example 1 is that three-stage sintering is not adopted.

[0140] Comparative Preparation Example 2

[0141] The difference between this comparative preparation example and preparation example 1 is that no cellulase is added.

[0142] Example 1

[0143] A preparation process of a light-curable silicone release film comprises the following steps:

[0144] S1. Mix 50 g of the natural porous organosilicon powder prepared in Preparation Example 1, 12 g of 2-hydroxyethyl methacrylate, 0.1 g of the organic photocatalyst 9-thioxanthone, and 0.3 g of the initiator tert-butyl hydroperoxide at 45° C. and stir evenly to obtain an organosilicon release agent;

[0145] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 30 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0146] Example 2

[0147] A preparation process of a light-curable silicone release film comprises the following steps:

[0148] S1. Mix and stir 50 g of the natural porous organosilicon powder prepared in Preparation Example 2, 12 g of 2-hydroxyethyl methacrylate, 0.1 g of the organic photocatalyst 9-thioxanthone, and 0.3 g of the initiator tert-butyl hydroperoxide at 45° C. to obtain an organosilicon release agent;

[0149] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0150] Example 3

[0151] A preparation process of a light-curing silicone release film comprises the following steps:

[0152] S1. Mix 50 g of the natural porous organosilicon powder prepared in Preparation Example 3, 12 g of 2-hydroxyethyl methacrylate, 0.1 g of the organic photocatalyst 9-thioxanthone, and 0.3 g of the initiator tert-butyl hydroperoxide at 45° C. and stir evenly to obtain an organosilicon release agent;

[0153] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0154] Example 4

[0155] A preparation process of a light-curable silicone release film comprises the following steps:

[0156] S1. Mix and stir 60 g of the natural porous organosilicon powder prepared in Preparation Example 4, 13 g of 2-hydroxyethyl methacrylate, 11 g of leveling agent BYK33, 0.12 g of organic photocatalyst 9-thioxanthone, and 0.3 g of initiator tert-butyl hydroperoxide at 45° C. to obtain an organosilicon release agent;

[0157] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0158] Example 5

[0159] A preparation process of a light-curable silicone release film comprises the following steps:

[0160] S1. Mix 60 g of the natural porous organosilicon powder prepared in Preparation Example 5, 13 g of 2-hydroxyethyl methacrylate, 11 g of a leveling agent BYK33, 0.12 g of an organic photocatalyst 9-thioxanthone, and 0.3 g of an initiator tert-butyl hydroperoxide at 45° C. and stir evenly to obtain an organosilicon release agent;

[0161] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0162] Example 6

[0163] A preparation process of a light-curable silicone release film comprises the following steps:

[0164] S1. Mix 60 g of the natural porous silicone powder prepared in Preparation Example 6, 13 g of 2-hydroxyethyl methacrylate, 11 g of a leveling agent BYK33, 0.12 g of an organic photocatalyst N-methylacridone, and 0.3 g of an initiator 2,2-azobisisobutyronitrile at 45° C. and stir evenly to obtain a silicone release agent;

[0165] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0166] Example 7

[0167] A preparation process of a light-curable silicone release film comprises the following steps:

[0168] S1. Mix 70 g of the natural porous organosilicon powder prepared in Preparation Example 7, 15 g of 2-hydroxyethyl methacrylate, 11 g of a leveling agent BYK33, 0.15 g of an organic photocatalyst N-methylacridone, and 0.5 g of an initiator tert-butyl hydroperoxide at 55° C. and stir evenly to obtain an organosilicon release agent;

[0169] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0170] Example 8

[0171] A preparation process of a light-curable silicone release film comprises the following steps:

[0172] S1. Mix 70 g of the natural porous organic silicon powder prepared in Preparation Example 8, 15 g of 2-hydroxyethyl methacrylate, 11 g of a leveling agent BYK33, 0.15 g of an organic photocatalyst N-methylacridone, and 0.5 g of an initiator 2,2-azobisisobutyronitrile at 55° C. and stir evenly to obtain an organic silicon release agent;

[0173] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0174] Example 9

[0175] A preparation process of a light-curable silicone release film comprises the following steps:

[0176] S1. Mix 70 g of the natural porous silicone powder prepared in Preparation Example 9, 15 g of 2-hydroxyethyl methacrylate, 11 g of a leveling agent BYK33, 0.15 g of an organic photocatalyst N-methylacridone, and 0.5 g of an initiator 2,2-azobisisobutyronitrile at 55° C. and stir evenly to obtain a silicone release agent;

[0177] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0178] Example 10

[0179] A preparation process of a light-curable silicone release film comprises the following steps:

[0180] S1. Mix and stir evenly the natural porous organosilicon powder 50 g prepared in Comparative Preparation Example 1, 12 g 2-hydroxyethyl methacrylate, 0.1 g organic photocatalyst 9-thioxanthone, and 0.3 g initiator tert-butyl hydroperoxide at 45° C. to obtain an organosilicon release agent;

[0181] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 30 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0182] Embodiment 11

[0183] A preparation process of a light-curable silicone release film comprises the following steps:

[0184] S1. Mix and stir evenly the natural porous organosilicon powder 50 g prepared in Comparative Preparation Example 2, 12 g 2-hydroxyethyl methacrylate, 0.1 g organic photocatalyst 9-thioxanthone, and 0.3 g initiator tert-butyl hydroperoxide at 45° C. to obtain an organosilicon release agent;

[0185] S2. The silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 30 μm, and cured under the conditions of a visible light wavelength of 450 nm, a curing reaction environment temperature of 40° C., and a reaction time of 5 hours to obtain a release film.

[0186] Comparative Example 1

[0187] The difference between this comparative example and Example 1 is that the natural porous organosilicon powder prepared in Preparation Example 1 is replaced by ordinary commercially available organosilicon powder purchased from Shanghai Longti Chemical Co., Ltd., model number 4-7105.

[0188] Comparative Example 2

[0189] The difference between this comparative example and Example 1 is that 50 g of the natural porous organosilicon powder prepared in Preparation Example 1 is replaced by 100 g.

[0190] Comparative Example 3

[0191] The difference between this comparative example and Example 1 is that in the preparation process of the natural porous organosilicon powder in Preparation Example 1, the operation of step S4 is not performed.

[0192] Comparative Example 4

[0193] The difference between this comparative example and Example 1 is that 2-hydroxyethyl methacrylate is replaced by common commercially available acrylate purchased from Aladdin with a CAS number of 96-33-3.

[0194] Comparative Example 5

[0195] The difference between this comparative example and Example 1 is that 12 g of 2-hydroxyethyl methacrylate is replaced by 3 g.

[0196] Comparative Example 6

[0197] The difference between this comparative example and Example 1 is that the wavelength of visible light is 300 nm.

[0198] The release films prepared in Examples 1-11 and Comparative Examples 1-6 were subjected to performance tests, and the structures are shown in Table 1:

[0199] Release force test tool: Tesa7475 tape; Method: Peel at 300mm / min, 180°;

[0200] Composting biodegradation rate: tested using the method of "GB / T 19277.1-2011 Determination of the final aerobic biodegradability of materials under controlled composting conditions using the method of measuring the released carbon dioxide";

[0201] Heat shrinkage rate: The heat shrinkage tester RSY-01 was used to test the transverse heat shrinkage rate of the release film of each sample after 30 minutes at 150°C. The smaller the value, the better the high temperature resistance.

[0202] Table 1: Effect test

[0203]

[0204] In summary, the light-cured silicone release films prepared in Examples 1-11 of the present invention have ultra-low peeling force, excellent aging release force, and low thermal shrinkage, which ensures that the laminating surface of the tape remains flat during storage and use, which is conducive to the smooth peeling and use of the tape, and can be used for continuous bonding of electronic product frames. The discarded release film is also highly degradable and will not affect the ecological environment.

[0205] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for preparing a light-curable silicone release film, characterized in that: The following steps are involved: S1, mixing natural silicone powder, 2-hydroxyethyl methacrylate, a leveling agent, an organic photocatalyst, and an initiator and stirring them uniformly to obtain a silicone release agent; S2. The silicone release agent prepared in step S1 is evenly coated on the PET substrate with a certain thickness, and cured under the irradiation of visible light to obtain a release film.

2. A process for preparing a light-curable silicone release film according to claim 1, characterized in that: The mass ratio of the natural organic silicon powder, 2-hydroxyethyl methacrylate, leveling agent, organic photocatalyst and initiator is (50-70): (10-15): (0-2): (0.1-0.15): (0.3-0.5).

3. The process for preparing a light-curable silicone release film according to claim 1, characterized in that: The preparation method of the natural organosilicon powder comprises the following steps: S1. By weight, 40-50 parts of foxtail grass, 1-2 parts of cellulase, and a concentration of (3-5)×10 11 CFU / g of Bacillus subtilis 1-3 parts and ammonium nitrate 4-6 parts are prepared into a mixture; S2, the mixture is fermented in a fermentation tank at 32-36°C for 5-6 hours to prepare a fermentation mixture, 30-35 parts of a 20-25% sodium carbonate solution are added to the fermentation mixture, and the mixture is soaked for 5-8 hours at a temperature of 85-95°C. After the soaking, the mixture is filtered to obtain a mixed extract; S3, the mixed extract is calcined in a sintering furnace in an inert gas and oxygen-free environment, compounded, and sintered in three stages to obtain natural organic silicon powder; S4. Mix γ-aminopropyltriethoxysilane with natural organic silicon powder and 95% ethanol solution in a mass ratio of 10:(3-5):(8-11), and at 85-100°C for 3-4 hours, the ethoxy group of γ-aminopropyltriethoxysilane reacts with the hydroxyl group on the surface of the silicon powder to undergo hydrolysis condensation reaction to obtain natural porous organic silicon powder.

4. A process for preparing a light-curable silicone release film according to claim 3, characterized in that: The natural organic silicon powder in step S3 is crushed to nanometer scale, with an average particle size of 35-55nm and an average specific surface area of ​​90-100m 2 / g.

5. The process for preparing a light-curable silicone release film according to claim 3, characterized in that: The conditions of the three-stage sintering are: The sintering conditions in the first stage are controlled as follows: heating to 780-810°C at a heating rate of 1-5°C / min, keeping the temperature for 4-5h, and obtaining preform I; The sintering conditions of the second stage are as follows: heating the preform I to 960-1010°C at a heating rate of 5-10°C / min, and keeping the temperature for 5-6h to obtain the preform II; The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800-820°C at a cooling rate of 1-3°C / min, and keeping the temperature for 5-6 hours to obtain natural organic silicon powder.

6. The process for preparing a light-curable silicone release film according to claim 1, characterized in that: The organic photocatalyst is 9-thioxanthone and / or N-methylacridone.

7. The process for preparing a light-curable silicone release film according to claim 1, characterized in that: The initiator is one or more of tert-butyl hydroperoxide, 2,2-azobisisobutyronitrile and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

8. The process for preparing a light-curable silicone release film according to claim 1, characterized in that: The wavelength of the visible light is ≥450 nm, the ambient temperature of the curing reaction is 35-50° C., and the reaction time is 3-8 hours.

9. The process for preparing a light-curable silicone release film according to claim 1, characterized in that: The thickness of the organic silicon release agent coated on the PET substrate is 30-50 μm.

10. The process for preparing a light-curable silicone release film according to claim 1, characterized in that: The leveling agent is selected from one or more of BYK331, EFKA3883, EFKA3600, and BYK366.

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