Preparation process of light-cured silicone release film

Abstract

The present application relates to the technical field of release film, and particularly relates to a preparation process of photocuring organic silicon release film, which comprises the following steps: S1, mixing and stirring natural organic silicon powder, 2-hydroxyethyl methacrylate, a leveling agent, an organic photocatalyst and an initiator uniformly to obtain an organic silicon release agent; S2, uniformly coating the organic silicon release agent prepared in the step S1 on a PET substrate with a certain thickness, and curing under the irradiation of visible light to obtain the release film. In the present application, the 2-hydroxyethyl methacrylate (HEMA) contains active double bonds and hydroxyl functional groups, and the surface of the porous organic silicon material has silicon hydroxyl groups (Si-OH), which can utilize the double bonds of the HEMA to carry out free radical polymerization reaction, and utilize the hydroxyl groups to carry out condensation reaction with the hydroxyl groups on the surface of the organic silicon to realize crosslinking. These chemical bonds are not easy to break in an acid-base environment, thereby ensuring the structural integrity of the material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of release films, in particular to a preparation process of a photocured organic silicon release film. BACKGROUND

[0002] Release films can be divided into BOPET release films, BOPP release films, PE release films, release films made of other organic materials and special-purpose release films according to the base materials selected. BOPET is widely used due to its good heat resistance, high mechanical strength, good surface flatness, high bonding strength with release agents and other advantages. The release agents used at present include organic silicon release agents, fluorine-containing release agents and silicate release agents. The organic silicon release agent has the advantages of good transparency, good isolation effect, high high-temperature resistance, solvent resistance, adjustable coating thickness and silicon content, good durability and reusability and the like. However, the surface tension of the release film formed by coating the organic silicon is relatively low and cannot meet the use requirements in special occasions. At present, the organic silicon is mainly modified to improve the surface tension of the release film, but the surface tension is increased at the same time, and the release film must have a relatively low peeling force.

[0003] In the preparation method of the release film, the photocuring technology is widely concerned due to its low solvent release amount (low VOC), fast curing speed, easy control of the curing area and curing degree, good production continuity and other advantages. Compared with the traditional thermal curing technology, energy saving and environmental protection are the most outstanding advantages, and the technology is also in line with the development direction of the industry. Ultraviolet light has higher energy and is the first choice for photocuring, but ultraviolet light has higher hazards and the curing process is long. Visible light curing is a relatively safer technology, but higher requirements are put forward for the photocatalytic material. In photocuring, the catalyst used at present is a metal material, for example, the preparation method of a visible light curing release film disclosed in Chinese patent CN107915790A uses a catalyst (fac tris(2-phenylpyridine) iridium) containing a noble metal. The use of the noble metal material greatly increases the production cost; in addition, the introduction of the metal into the release film also has adverse effects on the subsequent application. The addition of the natural porous organic silicon can avoid the pollution of the release film caused by the introduction of the metal, does not require an additional purification procedure, simplifies the production process, and has the functions of high-temperature resistance and oxidation resistance, so it is urgent to develop an economical and environmentally friendly photocured organic silicon release film that can be used in acid and alkali environments. SUMMARY

[0004] In order to solve the problems mentioned in the background art, the application provides a preparation process of a photocured organic silicon release film.

[0005] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0006] A preparation process of a photocured organic silicon release film comprises the following steps:

[0007] S1, mix and stir the natural silicone powder, 2-hydroxyethyl methacrylate, leveling agent, organic photocatalyst and initiator uniformly to obtain a silicone release agent;

[0008] S2, uniformly coat the silicone release agent prepared in step S1 on the PET substrate to a certain thickness, and cure under 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 preparation method of the natural porous silicone powder comprises the following steps:

[0011] S1, prepare a mixture by mixing 40-50 parts of dogtail grass, 1-2 parts of cellulase, 1-3 parts of Bacillus subtilis with a viable bacterial concentration of (3-5) x 10 11 CFU / g, and 4-6 parts of ammonium nitrate by weight;

[0012] S2, ferment the mixture in a fermenter at 32-36°C for 5-6 hours to prepare a fermentation mixture, add 30-35 parts of a 20-25% sodium carbonate solution to the fermentation mixture, soak for 5-8 hours, control the temperature at 85-95°C, filter after soaking, and obtain a mixed extract;

[0013] S3, calcine the mixed extract in a sintering furnace in an inert gas and oxygen-free environment, and compound by adopting a three-stage sintering process to obtain a natural silicone powder;

[0014] S4, mix g-aminopropyltriethoxysilane, natural silicone powder and 95% ethanol solution according to a mass ratio of 10:(3-5):(8-11), and perform a hydrolysis condensation reaction between the ethoxyl group of g-aminopropyltriethoxysilane and the hydroxyl group on the surface of the silicone powder at 85-100°C for 3-4 hours to obtain a natural porous silicone powder.

[0015] The hydrolysis condensation reaction between the ethoxyl group of g-aminopropyltriethoxysilane and the hydroxyl group on the surface of the silicone powder introduces an organic functional group, amino, to the surface of the silicone powder, which has better compatibility with organic materials, and also maintains the porous structure to a certain extent.

[0016] Preferably, the natural silicone powder is pulverized to a nanoscale, with an average particle size of 35-55 nm and an average specific surface area of 90-100 m 2 / g.

[0017] Preferably, the sintering conditions of the three stages are as follows:

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

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

[0020] The sintering conditions of the third stage are controlled as follows: cooling the preform II to 800-820 DEG C at a cooling rate of 1-3 DEG C / min, and holding for 5-6 h to obtain the natural silicone powder.

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

[0022] Preferably, the initiator is one or more of t-butyl hydroperoxide, 2,2-azobis isobutyronitrile and phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide.

[0023] Preferably, the wavelength of the visible light is greater than or equal to 450 nm, the ambient temperature of the curing reaction is 35-50 DEG 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 microns.

[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 application has the following advantages:

[0027] 1. The present application configures a visible light organic silicone release agent by using natural silicone 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), which avoids the introduction of metal elements, greatly expands the subsequent application field, and reduces the production cost.

[0028] 2. In the present application, 2-hydroxyethyl methacrylate (HEMA) contains active double bonds and hydroxyl functional groups, and the surface of the porous organic silicone material has silicon hydroxyl groups (Si-OH), which can utilize the double bonds of HEMA for free radical polymerization reaction, and utilize the hydroxyl groups for condensation reaction with the hydroxyl groups on the surface of the organic silicone to realize crosslinking.

[0029] For the free radical polymerization part, free radicals are generated by initiator decomposition, which initiates the opening of the double bond of HEMA and carries out polymerization reaction; the condensation reaction can be carried out under acidic or basic conditions to form a silicon-oxygen bond (Si-O-Si), thereby connecting HEMA with porous organosilica. These chemical bonds are not easily broken in acidic or basic environments, thereby ensuring the structural integrity of the material.

[0030] And the crosslinked HEMA forms a continuous organic polymer protective layer on the surface of the porous organosilica, which can block the direct contact of the acid-base solution with the porous organosilica and reduce the erosion of the acid-base on the organosilica material.

[0031] 3. The natural organosilica powder in the present application is derived from the herb dogtail grass, has the characteristics of biodegradability, and also has excellent high-temperature resistance, which can improve the heat resistance of the release film and enable it to maintain stable performance in a high-temperature environment. In addition, the pores of the natural organosilica powder are easily penetrated and eroded by acid-base solution, and the crosslinked HEMA fills part of the pores, reduces the exposure degree of the pores, and reduces the diffusion speed of the acid-base solution in the pores, further enhancing the acid-base resistance of the release film and prolonging its service life. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0033] Unless otherwise specified, the raw materials used in the present application are all purchased from the market and are conventional products. Among them, 2-hydroxyethyl methacrylate is purchased from Alibaba, Shouguang City Lisheng Chemical Co., Ltd., CAS number: 868-77-9;

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

[0035] N-methylacridone is purchased from Clove, with the item number YJ-1030661;

[0036] 2,2-azobis (isobutyronitrile) is purchased from Aladdin, CAS number: 78-67-1;

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

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

[0039] Preparation Example 1

[0040] The preparation method of the natural porous organosilicon powder comprises the following steps:

[0041] S1, dog tail 40g, cellulase 1g, Bacillus subtilis with a viable bacterial concentration of 3×10 11 CFU / g 2g, ammonium nitrate 4g were prepared into a mixed material;

[0042] S2, the mixed material was subjected to aerobic fermentation in a fermentation tank at 32℃ for 6 hours to prepare a fermentation mixed material, 50mL of 20% sodium carbonate solution was added to the fermentation mixed material, and soaking was performed for 7 hours, with the temperature being controlled at 85℃, after the soaking was completed, filtration was performed to obtain a mixed extract;

[0043] S3, the mixed extract was subjected to calcination and compounding in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, three-stage sintering was adopted, and a natural organosilicon powder was prepared;

[0044] S4, 10g of γ-aminopropyl triethoxysilane was mixed with 5g of the natural organosilicon powder and 11g of 95% ethanol solution, hydrolytic condensation reaction occurred between the ethoxyl group of the γ-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicon powder at 85℃ and a reaction time of 3 hours, and the natural porous organosilicon powder was obtained.

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

[0046] The sintering conditions of the first stage were controlled as follows: the temperature was raised to 780℃ at a temperature raising rate of 1℃ / min, and the temperature was maintained for 4h to obtain a preform I;

[0047] The sintering conditions of the second stage were controlled as follows: the preform I was raised to 960℃ at a temperature raising rate of 5℃ / min, and the temperature was maintained for 5h to obtain a preform II;

[0048] The sintering conditions of the third stage were controlled as follows: the preform II was lowered to 800℃ at a temperature lowering rate of 1℃ / min, and the temperature was maintained for 5h to obtain the natural organosilicon powder.

[0049] The natural organosilicon powder is pulverized to a nanoscale, the average particle size is 35nm, and the average specific surface area is 100m 2 / g.

[0050] Preparation Example 2

[0051] The preparation method of the natural porous organosilicon powder comprises the following steps:

[0052] S1, dog tail 42g, cellulase 1.5g, Bacillus subtilis with a viable bacterial concentration of 3×10 11 CFU / g 1g, ammonium nitrate 4g were prepared into a mixed material;

[0053] S2, the mixture is fermented in a 33℃ fermentation tank for 6 hours to produce a fermented mixture, 30g of a 20% sodium carbonate solution is added to the fermented mixture, soaked for 7 hours, the temperature is controlled at 85℃, after soaking, filtration is performed to obtain a mixed extract;

[0054] S3, the mixed extract is calcined and compounded in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, three-stage sintering is adopted to produce natural organic silicon powder;

[0055] S4, 10g of γ-aminopropyl triethoxysilane is mixed with 5g of natural organic silicon powder and 11g of 95% ethanol solution, hydrolytic condensation reaction occurs between the ethoxyl group of the γ-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicon powder at 85℃ and a reaction time of 4 hours, and natural porous organic silicon powder is obtained.

[0056] The three-stage sintering conditions are as follows:

[0057] The sintering conditions of the first stage are controlled as follows: the temperature is raised to 780℃ at a rate of 1℃ / min, and the temperature is maintained for 4h to obtain a preform I;

[0058] The sintering conditions of the second stage are controlled as follows: the preform I is heated to 960℃ at a rate of 5℃ / min, and the temperature is maintained for 5h to obtain a preform II;

[0059] The sintering conditions of the third stage are controlled as follows: the preform II is cooled to 800℃ at a rate of 1℃ / min, and the temperature is maintained for 5h to produce natural organic silicon powder.

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

[0061] Preparation Example 3

[0062] The preparation method of the natural porous organic silicon powder comprises the following steps:

[0063] S1, 45g of dogtail grass, 1.5g of cellulase, 2g of Bacillus subtilis with a viable bacterial concentration of 3×10 11 CFU / g, and 5g of ammonium nitrate are prepared into a mixture;

[0064] S2, the mixture is fermented in a 35℃ fermentation tank for 6 hours to produce a fermented mixture, 30g of a 25% sodium carbonate solution is added to the fermented mixture, soaked for 7 hours, the temperature is controlled at 85℃, after soaking, filtration is performed to obtain a mixed extract;

[0065] S3, the mixed extract is calcined and compounded in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, three-stage sintering is adopted to produce natural organic silicon powder;

[0066] S4, 10 g of gamma-aminopropyl triethoxysilane is mixed with 5 g of natural silicon powder, 11 g of 95% ethanol solution, and hydrolytic condensation reaction of the ethoxyl group of the gamma-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicon powder occurs at 90 DEG C and a reaction time of 4 hours, and the natural porous silicon powder is obtained.

[0067] The three-stage sintering conditions are as follows:

[0068] The sintering conditions of the first stage are controlled as follows: temperature is raised to 780 DEG C at a rate of 1 DEG C / min, and the temperature is kept constant for 4 h, and the preform I is obtained;

[0069] The sintering conditions of the second stage are controlled as follows: the preform I is heated to 960 DEG C at a rate of 5 DEG C / min, and the temperature is kept constant for 5 h, and the preform II is obtained;

[0070] The sintering conditions of the third stage are controlled as follows: the preform II is cooled to 800 DEG C at a rate of 1 DEG C / min, and the temperature is kept constant for 5 h, and the natural silicon powder is obtained.

[0071] The natural silicon powder is pulverized to a nanoscale, and the average particle size is 35 nm, and the average specific surface area is 100 m 2 / g.

[0072] Preparation Example 4

[0073] The preparation method of the natural porous silicon powder comprises the following steps:

[0074] S1, 46 g of dogtail grass, 2 g of cellulase, 3 g of Bacillus subtilis with a living bacteria concentration of 3 x 10 11 CFU / g, and 5 g of ammonium nitrate are prepared into a mixture;

[0075] S2, the mixture is fermented in a 35 DEG C fermentation tank for 6 h, and a fermented mixture is prepared, 32 g of a 23% sodium carbonate solution is added to the fermented mixture, and soaked for 7 h, the temperature is controlled at 90 DEG C, after the soaking is completed, filtration is performed, and a mixed extract is obtained;

[0076] S3, the mixed extract is calcined and compounded in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, three-stage sintering is adopted, and the natural silicon powder is obtained;

[0077] S4, 10 g of gamma-aminopropyl triethoxysilane is mixed with 4 g of natural silicon powder, and 10 g of 95% ethanol solution, and hydrolytic condensation reaction of the ethoxyl group of the gamma-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicon powder occurs at 90 DEG C and a reaction time of 3 h, and the natural porous silicon powder is obtained.

[0078] The three-stage sintering conditions are as follows:

[0079] The sintering condition of the first stage is controlled as follows: temperature rising to 800℃ at a rate of 2℃ / min, and keeping for 5h, to obtain a preform I;

[0080] The sintering condition of the second stage is controlled as follows: temperature rising to 1000℃ at a rate of 8℃ / min for the preform I, and keeping for 5h, to obtain a preform II;

[0081] The sintering condition of the third stage is controlled as follows: temperature dropping to 810℃ at a rate of 2℃ / min for the preform II, and keeping for 5h, to obtain the natural organic silicon powder.

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

[0083] Preparation Example 5

[0084] The preparation method of the natural porous organic silicon powder comprises the following steps:

[0085] S1, 46g of dogtail grass, 2g of cellulase, 3g of Bacillus subtilis with a viable bacterial concentration of 4×10 11 CFU / g, and 5g of ammonium nitrate are prepared into a mixture;

[0086] S2, the mixture is fermented in a 35℃ fermentation tank for 6h to prepare a fermentation mixture, 32g of a 25% sodium carbonate solution is added to the fermentation mixture and soaked for 8h, the temperature is controlled at 90℃, after the soaking is completed, filtration is performed to obtain a mixed extract;

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

[0088] S4, 10g of γ-aminopropyl triethoxysilane is mixed with 4g of the natural organic silicon powder and 10g of a 95% ethanol solution, and a hydrolysis condensation reaction occurs between the ethoxyl groups of the γ-aminopropyl triethoxysilane and the hydroxyl groups on the surface of the silicon powder at 95℃ and for 4h, to obtain the natural porous organic silicon powder.

[0089] The sintering condition of the three-stage sintering is as follows:

[0090] The sintering condition of the first stage is controlled as follows: temperature rising to 800℃ at a rate of 2℃ / min, and keeping for 5h, to obtain a preform I;

[0091] The sintering condition of the second stage is controlled as follows: temperature rising to 1000℃ at a rate of 8℃ / min for the preform I, and keeping for 5h, to obtain a preform II;

[0092] The third stage sintering condition is controlled as follows: the preform II is cooled to 810℃ at a cooling rate of 2℃ / min, and kept for 5h, to obtain the natural organic silicon powder.

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

[0094] Preparation Example 6

[0095] The preparation method of the natural porous organic silicon powder comprises the following steps:

[0096] S1, 48g of dogtail grass, 2g of cellulase, 3g of Bacillus subtilis with a viable bacterial concentration of 3×10 11 CFU / g, and 6g of ammonium nitrate are prepared into a mixture;

[0097] S2, the mixture is fermented in a fermentation tank at 35℃ for 6h to obtain a fermented mixture, 32g of a 25% sodium carbonate solution is added to the fermented mixture and soaked for 8h, the temperature is controlled at 90℃, after the soaking is completed, filtration is performed to obtain a mixed extract;

[0098] S3, the mixed extract is calcined and compounded in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, three-stage sintering is adopted, and the natural organic silicon powder is obtained;

[0099] S4, 10g of γ-aminopropyl triethoxysilane, 4g of the natural organic silicon powder, and 10g of a 95% ethanol solution are mixed, hydrolytic condensation reaction occurs between the ethoxyl groups of the γ-aminopropyl triethoxysilane and the hydroxyl groups on the surface of the silicon powder at 95℃ and for 3h, and the natural porous organic silicon powder is obtained.

[0100] The three-stage sintering condition is as follows:

[0101] The first stage sintering condition is controlled as follows: the temperature is increased to 800℃ at a heating rate of 2℃ / min, and kept for 5h, to obtain a preform I;

[0102] The second stage sintering condition is controlled as follows: the preform I is heated to 1000℃ at a heating rate of 8℃ / min, and kept for 5h, to obtain a preform II;

[0103] The third stage sintering condition is controlled as follows: the preform II is cooled to 810℃ at a cooling rate of 2℃ / min, and kept for 5h, to obtain the natural organic silicon powder.

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

[0105] Preparation Example 7

[0106] The preparation method of the natural porous organosilicon powder comprises the following steps:

[0107] S1, 50g of dogtail grass, 2g of cellulase, 3g of Bacillus subtilis with a viable bacterial concentration of 5×10 11 CFU / g, and 6g of ammonium nitrate are prepared into a mixed material;

[0108] S2, the mixed material is fermented in a 36℃ fermentation tank for 6 hours to prepare a fermentation mixed material, 35g of a 25% sodium carbonate solution is added to the fermentation mixed material, and soaking is performed for 8 hours, with the temperature being controlled at 95℃; after the soaking is completed, filtration is performed to obtain a mixed extract;

[0109] S3, the mixed extract is calcined in a sintering furnace in a nitrogen atmosphere and an oxygen-free environment, and is compounded by adopting three-stage sintering to prepare the natural organosilicon powder;

[0110] S4, 10g of γ-aminopropyl triethoxysilane, 3g of the natural organosilicon powder, and 8g of a 95% ethanol solution are mixed, and hydrolytic condensation reaction occurs between the ethoxyl groups of the γ-aminopropyl triethoxysilane and the hydroxyl groups on the surface of the silicon powder at 100℃ and for 3 hours, and the natural porous organosilicon powder is obtained.

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

[0112] The sintering conditions of the first stage are controlled as follows: the temperature is raised to 780℃ at a temperature raising rate of 2℃ / min, and the temperature is kept for 4h to obtain a preform I;

[0113] The sintering conditions of the second stage are controlled as follows: the preform I is raised to 980℃ at a temperature raising rate of 5℃ / min, and the temperature is kept for 5h to obtain a preform II;

[0114] The sintering conditions of the third stage are controlled as follows: the preform II is lowered to 800℃ at a temperature lowering rate of 1℃ / min, and the temperature is kept for 5h to obtain the natural organosilicon powder.

[0115] The natural organosilicon powder is pulverized to a nanoscale, and the average particle size is 45nm, and the average specific surface area is 95m 2 / g.

[0116] Preparation Example 8

[0117] The preparation method of the natural porous organosilicon powder comprises the following steps:

[0118] S1, 50g of dogtail grass, 2g of cellulase, 3g of Bacillus subtilis with a viable bacterial concentration of 5×10 11 CFU / g, and 6g of ammonium nitrate are prepared into a mixed material;

[0119] S2, the mixture is fermented in a 36℃ fermentation tank for 6 hours to produce fermented mixture, 35g of 25% sodium carbonate solution is added to the fermented mixture, soaked for 8 hours, the temperature is controlled at 95℃, after soaking, filtration is performed to obtain mixed extract;

[0120] S3, the mixed extract is calcined and compounded in a sintering furnace in a nitrogen atmosphere and oxygen-free environment, three-stage sintering is adopted to produce natural organic silicon powder;

[0121] S4, 10g of γ-aminopropyl triethoxysilane is mixed with 3g of natural organic silicon powder and 8g of 95% ethanol solution, hydrolytic condensation reaction occurs between the ethoxyl group of the γ-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicon powder at 100℃ and for 4 hours, and the natural porous organic silicon powder is obtained.

[0122] The three-stage sintering conditions are as follows:

[0123] The sintering conditions of the first stage are controlled as follows: the temperature is raised to 780℃ at a rate of 3℃ / min, and the temperature is maintained for 4h to obtain preform I;

[0124] The sintering conditions of the second stage are controlled as follows: the preform I is heated to 980℃ at a rate of 5℃ / min, and the temperature is maintained for 5h to obtain preform II;

[0125] The sintering conditions of the third stage are controlled as follows: the preform II is cooled to 810℃ at a rate of 2℃ / min, and the temperature is maintained for 5h to obtain natural organic silicon powder.

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

[0127] Preparation Example 9

[0128] The preparation method of the natural porous organic silicon powder comprises the following steps:

[0129] S1, 50g of dogtail grass, 2g of cellulase, 3g of bacillus subtilis with a viable bacterial concentration of 5×10 11 CFU / g, and 6g of ammonium nitrate are prepared into a mixture;

[0130] S2, the mixture is fermented in a 36℃ fermentation tank for 6 hours to produce fermented mixture, 35g of 25% sodium carbonate solution is added to the fermented mixture, soaked for 8 hours, the temperature is controlled at 95℃, after soaking, filtration is performed to obtain mixed extract;

[0131] S3, the mixed extract is calcined and compounded in a sintering furnace in a nitrogen atmosphere and oxygen-free environment, three-stage sintering is adopted to produce natural organic silicon powder;

[0132] S4, mixing 10 g of gamma-aminopropyl triethoxysilane with 3 g of natural silicone powder and 8 g of 95% ethanol solution, and carrying out hydrolytic condensation reaction between the ethoxyl group of the gamma-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicone powder at 100°C for 4 hours to obtain the natural porous silicone powder.

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

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

[0135] The sintering conditions of the second stage are controlled as follows: heating the preform I to 1010°C at a heating rate of 10°C / min, and holding for 5 h to obtain the 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 holding for 5 h to obtain the natural silicone powder.

[0137] The natural silicone powder is pulverized to a nanoscale, with an average particle size of 46 nm and an average specific surface area of 94 m 2 / g.

[0138] Comparative Preparation Example 1

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

[0140] Comparative Preparation Example 2

[0141] The difference between this comparative preparation example and Preparation Example 1 is that the cellulase is not added.

[0142] Example 1

[0143] A preparation process of a photocurable silicone release film, comprising the following steps:

[0144] S1, mixing 50 g of the natural porous silicone powder prepared in Preparation Example 1, 12 g of 2-hydroxyethyl methacrylate, 0.1 g of an organic photocatalyst 9-thioxanthone, and 0.3 g of an initiator tert-butyl hydroperoxide at a temperature of 45°C and stirring uniformly to obtain an organic silicone release agent;

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

[0146] Example 2

[0147] A preparation process of a photocured silicone release film, comprising the following steps:

[0148] S1, the natural porous silicone powder prepared in preparation example 2 50g, 2-hydroxyethyl methacrylate 12g, organic photocatalyst 9-thioxanthone 0.1g, initiator tert-butyl hydroperoxide 0.3g is mixed and stirred uniformly at 45℃ temperature, and the silicone release agent is obtained;

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

[0150] Example 3

[0151] A preparation process of a photocured silicone release film, comprising the following steps:

[0152] S1, the natural porous silicone powder prepared in preparation example 3 50g, 2-hydroxyethyl methacrylate 12g, organic photocatalyst 9-thioxanthone 0.1g, initiator tert-butyl hydroperoxide 0.3g is mixed and stirred uniformly at 45℃ temperature, and the silicone release agent is obtained;

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

[0154] Example 4

[0155] A preparation process of a photocured silicone release film, comprising the following steps:

[0156] S1, the natural porous silicone powder prepared in preparation example 4 60g, 2-hydroxyethyl methacrylate 13g, leveling agent BYK331 1g, organic photocatalyst 9-thioxanthone 0.12g, initiator tert-butyl hydroperoxide 0.3g is mixed and stirred uniformly at 45℃ temperature, and the silicone release agent is obtained;

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

[0158] Example 5

[0159] A preparation process of a photocured silicone release film, comprising the following steps:

[0160] S1, the natural porous silicone powder prepared in preparation example 5 60g, 2-hydroxyethyl methacrylate 13g, leveling agent BYK331 1g, organic photocatalyst 9-thioxanthone 0.12g, initiator tert-butyl hydroperoxide 0.3g are mixed and stirred uniformly at a temperature of 45℃, to obtain a silicone release agent;

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

[0162] Example 6

[0163] A preparation process of a photocured silicone release film, comprising the following steps:

[0164] S1, the natural porous silicone powder prepared in preparation example 6 60g, 2-hydroxyethyl methacrylate 13g, leveling agent BYK331 1g, organic photocatalyst N-methyl acridone 0.12g, initiator 2,2-azobis isobutyronitrile 0.3g are mixed and stirred uniformly at a temperature of 45℃, 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 31μm, and is cured under the conditions that the wavelength of visible light is 450nm, the ambient temperature of the curing reaction is 40℃, and the reaction time is 5 hours, to obtain a release film.

[0166] Example 7

[0167] A preparation process of a photocured silicone release film, comprising the following steps:

[0168] S1, the natural porous silicone powder prepared in preparation example 7 70g, 2-hydroxyethyl methacrylate 15g, leveling agent BYK331 1g, organic photocatalyst N-methyl acridone 0.15g, initiator tert-butyl hydroperoxide 0.5g are mixed and stirred uniformly at a temperature of 55℃, to obtain a silicone release agent;

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

[0170] Example 8

[0171] A preparation process of a photocured silicone release film, comprising the following steps:

[0172] S1, the natural porous silicone powder prepared in preparation example 8 70g, 2-hydroxyethyl methacrylate 15g, leveling agent BYK331 1g, organic photocatalyst N-methyl acridone 0.15g, initiator 2,2-azobisisobutyronitrile 0.5g are mixed and stirred uniformly at a temperature of 55℃, to obtain a silicone release agent;

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

[0174] Example 9

[0175] A preparation process of a photocured silicone release film, comprising the following steps:

[0176] S1, the natural porous silicone powder prepared in preparation example 9 70g, 2-hydroxyethyl methacrylate 15g, leveling agent BYK331 1g, organic photocatalyst N-methyl acridone 0.15g, initiator 2,2-azobisisobutyronitrile 0.5g are mixed and stirred uniformly at a temperature of 55℃, 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 31μm, and is cured under the conditions that the wavelength of visible light is 450nm, the environmental temperature of the curing reaction is 40℃, and the reaction time is 5 hours, to obtain a release film.

[0178] Example 10

[0179] A preparation process of a photocured silicone release film, comprising the following steps:

[0180] S1, the natural porous silicone powder prepared in preparation example 9 70g, 2-hydroxyethyl methacrylate 15g, leveling agent BYK331 1g, organic photocatalyst N-methyl acridone 0.15g, initiator 2,2-azobisisobutyronitrile 0.5g are mixed and stirred uniformly at a temperature of 55℃, to obtain a silicone release agent;

[0181] S2, the silicone release agent prepared in step S1 is uniformly coated on the PET substrate with a thickness of 31μm, and is cured under the conditions that the wavelength of visible light is 450nm, the environmental temperature of the curing reaction is 40℃, and the reaction time is 5 hours, to obtain a release film.

[0182] Example 11

[0183] A preparation process of a photocured silicone release film, comprising the following steps:

[0184] S1, 50 g of the natural porous silicone powder prepared in Comparative Preparation 2, 12 g of 2-hydroxyethyl methacrylate, 0.1 g of an organic photocatalyst 9-thioxanthone, and 0.3 g of an initiator t-butyl hydroperoxide were mixed and stirred uniformly at a temperature of 45°C to obtain a silicone release agent;

[0185] S2, the silicone release agent prepared in step S1 was uniformly coated on a PET substrate at a thickness of 30 pm, and cured under the conditions that the wavelength of visible light was 450 nm, the ambient temperature of the curing reaction was 40°C, and the reaction time was 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 silicone powder prepared in Preparation Example 1 is replaced with a common commercially available silicone powder, which is purchased from Shanghai Longti Chemical Co., Ltd., and the model number is 4-7105.

[0188] Comparative Example 2

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

[0190] Comparative Example 3

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

[0192] Comparative Example 4

[0193] The difference between this comparative example and Example 1 is that the 2-hydroxyethyl methacrylate is replaced with a common commercially available acrylate, which is purchased from Aldrich, and the CAS number is 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 with 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 tested for performance, and the structure is shown in Table 1:

[0199] Release force testing tool: Tesa7475 tape; method: 300 mm / min, 180° peeling;

[0200] Compostable biodegradation rate: test according to GB / T 19277.1-2011 Determination of ultimate aerobic biodegradation of materials under controlled composting conditions - Method using measured carbon dioxide evolution;

[0201] Heat shrinkage rate: test the transverse heat shrinkage rate of the release film after 30 min at 150 DEG C using a heat shrinkage tester RSY-01, and the smaller the value, the better the high temperature resistance.

[0202] Table 1: Effect test

[0203]

[0204] In summary: the light-cured silicone release film prepared in examples 1-11 has ultra-low peeling force, excellent aging release force, and low heat shrinkage rate, ensuring that the adhered surface remains flat during storage and use, facilitating smooth peeling and use of the adhesive tape, and can be used for continuous bonding of electronic product frames. The discarded release film also has good degradability and does not affect the ecological environment.

[0205] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A process for producing a photocured silicone release film, characterized by, The method comprises the following steps: S1, mixing and stirring natural porous organosilica powder, 2-hydroxyethyl methacrylate, leveling agent, organic photocatalyst and initiator to obtain organosilicon release agent; S2, uniformly coating the organosilicon release agent prepared in step S1 on the PET substrate to a certain thickness, and curing under visible light irradiation to obtain a release film; The mass ratio of the natural porous organosilica 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). The preparation method of the natural porous organosilica powder comprises the following steps: S1, 40-50 parts by weight of dogtail grass, 1-2 parts of cellulase, 1-3 parts of bacillus subtilis with a living bacteria concentration of (3-5)×10 11 CFU / g, 4-6 parts of ammonium nitrate are prepared into a mixture; S2, fermenting the mixed material in a 32-36℃ fermenter for 5-6 hours to prepare fermented mixed material, adding 30-35 parts of 20-25% sodium carbonate solution to the fermented mixed material, soaking for 5-8 hours, controlling the temperature at 85-95℃, filtering after the soaking is completed, and obtaining mixed extract; S3, calcining the mixed extract in an inert gas and oxygen-free environment sintering furnace, compounding, and using three-stage sintering to prepare natural organosilica powder; S4, mixing γ-aminopropyl triethoxysilane, natural organosilica powder and 95% ethanol solution according to a mass ratio of 10:(3-5):(8-11), and performing hydrolysis and condensation reaction between the ethoxyl group of the γ-aminopropyl triethoxysilane and the hydroxyl group on the surface of the silicon powder at 85-100℃ and for 3-4 hours to obtain natural porous organosilica powder.

2. The preparation process of photocured silicone release film according to claim 1, characterized in that, The natural silicone powder in step S3 is pulverized to nanoscale, with an average particle size of 35-55 nm and an average specific surface area of 90-100 m 2 / g.

3. The preparation process of photocured silicone release film according to claim 1, characterized in that, The three-stage sintering conditions are as follows: The first-stage sintering condition is controlled as follows: increasing the temperature to 780-810℃ at a temperature increasing rate of 1-5℃ / min, and maintaining the temperature for 4-5h to obtain preform I; The second-stage sintering condition is controlled as follows: increasing the temperature of the preform I to 960-1010℃ at a temperature increasing rate of 5-10℃ / min, and maintaining the temperature for 5-6h to obtain preform II; The third-stage sintering condition is controlled as follows: decreasing the temperature of the preform II to 800-820℃ at a temperature decreasing rate of 1-3℃ / min, and maintaining the temperature for 5-6h to obtain natural organosilica powder.

4. The preparation process of photocured silicone release film according to claim 1, characterized in that, The organic photocatalyst is 9-thioxanthone and / or N-methyl acridone.

5. The preparation process of photocured silicone release film according to claim 1, characterized in that, The initiator is one or more of tert-butyl hydroperoxide, 2,2-azobis isobutyronitrile and phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide.

6. The preparation process of photocured silicone release film according to claim 1, characterized in that, The wavelength of the visible light is ≥450nm, the environmental temperature of the curing reaction is 35-50℃, and the reaction time is 3-8 hours.

7. The preparation process of photocured silicone release film according to claim 1, characterized in that, The thickness of the organosilicon release agent coated on the PET substrate is 30-50μm.

8. The preparation process of photocured 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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