阅读说明：本技术 一种微晶强化离型膜 (Microcrystalline reinforced release film ) 是由 李益玮 冯彬 许晋嘉 施绍富 杨雍华 陈思垒 于 2021-09-03 设计创作，主要内容包括：本发明属于离型膜技术领域,具体涉及一种微晶强化离型膜,由PET基材、含氟-微晶纤维素嵌段聚氨酯、甲苯组成,所述含氟-微晶纤维素嵌段聚氨酯是以微晶纤维素为扩链基点的三维网络,同时全氟分子分布在三维网络上,所述含氟-微晶纤维素嵌段聚氨酯由化微晶纤维素、羟基功能化的含氟物、二元醇和二异氰酸酯反应制得,本微晶强化离型膜的制备方法包括：(1)羟基功能化含氟物的制备；(2)含氟-微晶纤维素嵌段聚氨酯的制备；(3)离型膜的制备。本发明以微晶纤维素作为三维网络的交联点,提高了离型剂的交联密度,增加了复合材料分子之间的结合力,阻碍了大分子链的运动,增强了离型膜的机械性能和热稳定性。(The invention belongs to the technical field of release films, and particularly relates to a microcrystal-reinforced release film which is composed of a PET (polyethylene terephthalate) substrate, fluorine-containing microcrystalline cellulose block polyurethane and toluene, wherein the fluorine-containing microcrystalline cellulose block polyurethane is a three-dimensional network taking microcrystalline cellulose as a chain extension base point, and perfluorinated molecules are distributed on the three-dimensional network, the fluorine-containing microcrystalline cellulose block polyurethane is prepared by reacting chemical microcrystalline cellulose, hydroxyl functionalized fluorine-containing substances, dihydric alcohol and diisocyanate, and the preparation method of the microcrystal-reinforced release film comprises the following steps: (1) preparing hydroxyl functional fluorine-containing substances; (2) preparing fluorine-microcrystalline cellulose block polyurethane; (3) and (5) preparing a release film. According to the invention, microcrystalline cellulose is taken as a cross-linking point of the three-dimensional network, so that the cross-linking density of the release agent is improved, the binding force between molecules of the composite material is increased, the movement of a macromolecular chain is hindered, and the mechanical property and the thermal stability of the release film are enhanced.)

1. The microcrystal-reinforced release film is characterized in that: the fluorine-containing microcrystalline cellulose segmented polyurethane is prepared by reacting microcrystalline cellulose, hydroxyl functionalized fluorine-containing substance, dihydric alcohol and diisocyanate.

2. The microcrystalline reinforced release film according to claim 1, wherein: the length of the microcrystalline cellulose is 20-35 mu m, the polymerization degree of the microcrystalline cellulose is 30-50, and the thickness of the PET base material is 50-100 mu m.

3. The microcrystalline reinforced release film according to claim 1, wherein: the diisocyanate comprises any one of isophorone diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate, and the dihydric alcohol is at least one of ethylene glycol, propylene glycol and butanediol.

4. The method for preparing the microcrystal-reinforced release film according to any one of claims 1,2 and 3, characterized in that: the method comprises the following steps:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding perfluorooctanoic acid and 2-amino-2 methyl-1, 3-propylene glycol into a mixed solution of dichloromethane and ethanol, adding a condensing agent, stirring for 8-12h in a dark environment, removing the solvent by using a rotary evaporator after the reaction is finished, grinding the obtained product for 10min by using 30ml of diethyl ether, filtering, washing with diethyl ether, and drying to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving diisocyanate and dibutyltin dilaurate in a tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving the hydroxyl-functionalized fluorine-containing substance, microcrystalline cellulose and dihydric alcohol prepared in the step (1) in a tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under the nitrogen atmosphere, heating the mixture to 70 ℃ under the nitrogen atmosphere after dropwise adding, continuously stirring for reacting for 4-6h, cooling to room temperature, filtering, washing with diethyl ether, and drying to obtain the fluorine-microcrystalline cellulose block polyurethane;

(3) dissolving the fluorine-microcrystalline cellulose block polyurethane prepared in the step (2) in toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on the PET substrate subjected to plasma treatment by using a coating machine, and curing at the temperature of 120-150 ℃ for 5-8min to obtain the microcrystalline reinforced release film.

5. The preparation method of the microcrystal-reinforced release film according to claim 4, characterized in that: the mass ratio of the perfluorooctanoic acid, the 2-amino-2-methyl-1, 3-propanediol and the condensing agent in the step (1) is 8-8.5:2.2-2.5: 9.5-10.

6. The preparation method of the microcrystal-reinforced release film according to claim 4, characterized in that: the condensing agent in the step (1) is 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, and the volume ratio of dichloromethane to ethanol of the mixed solution of dichloromethane and ethanol is 2: 1.

7. The preparation method of the microcrystal-reinforced release film according to claim 4, characterized in that: the drying conditions in the step (1) and the step (2) are drying for 18-24h in an oven at 70-80 ℃.

8. The preparation method of the microcrystal-reinforced release film according to claim 4, characterized in that: in the step (2), the mass ratio of diisocyanate, dibutyltin dilaurate, hydroxyl-functionalized fluorine-containing substance, microcrystalline cellulose and dihydric alcohol is 22-25:0.8:2.5-2.8:5-7: 2.8-4.

9. The method for preparing the microcrystal reinforced release film according to claim 4The preparation method is characterized by comprising the following steps: setting the plasma processing parameters in the step (3) as that the peak-to-peak value of the power supply voltage is set as 22kV, the frequency is 8kHz, the air gap distance is fixed as 1mm, and the power density of discharge is 24.5W/cm³The treatment time is 30-60 s.

10. The preparation method of the microcrystal-reinforced release film according to claim 4, characterized in that: the mass-volume ratio of the fluorine-containing microcrystalline cellulose segmented polyurethane to the toluene in the step (3) is 2-3g:6-8ml, and the wet coating amount of the release agent in the step (3) is 5-7g/m²。

Technical Field

The invention relates to the technical field of release films, in particular to a microcrystal reinforced release film.

Background

Release films are films whose surface energy is differentiated, and release films are not sticky or slightly sticky after being contacted with a particular material under limited conditions. Release films, also known as release film and release film separation films, are known in many different contexts. The PET release film is prepared by carrying out surface treatment on a PET substrate, and comprises a silicon release agent and a fluorine release agent which are coated or plasma treatment is carried out to ensure that the PET release film has extremely light and stable release force on different organic pressure-sensitive adhesives, which is the most common release film product. At present, PET release films are widely applied to the fields of packaging, printing, silk-screen printing, transfer printing, nameplates, film switches, flexible circuits, insulating products, circuit boards, laser anti-counterfeiting laminating, film reflecting materials for electronics and sealing materials, waterproof materials, medicines (plaster paper), sanitary paper, adhesive products, die cutting and punching processing and the like.

The PET release film is subjected to evaporation, multiple coating, compounding and final stripping, and the temperature of the procedures and the processing procedures is mostly 120-150 ℃. Thus, the quality requirement of the PET film as a carrier in the whole processing process is relatively high, and the requirements on the flatness, the cleanness and the thermal stability of the film are particularly high. However, the release agent coated with the PET comprises organic silicone oil, fluorine-containing silicone oil and a non-silicon polymer, and the common polyamino acrylate in the non-silicon polymer is used as a main matrix of the release agent, so that the elasticity of the release film can be effectively improved, but the thermal stability is general, the mechanical property is not good, the service life of the release film is short, and the practical application of the release film is limited.

Disclosure of Invention

Technical problem to be solved

The invention aims to provide a microcrystal reinforced release film, which solves the problem that a PET release film is not strong in thermal stability and mechanical property.

(II) technical scheme

In order to solve the above problems, the present invention provides the following solutions:

the microcrystal-reinforced release film consists of a PET (polyethylene terephthalate) base material, fluorine-containing microcrystalline cellulose segmented polyurethane and toluene, wherein the fluorine-containing microcrystalline cellulose segmented polyurethane is a three-dimensional network taking microcrystalline cellulose as a chain extension base point, and perfluorinated molecules are distributed on the three-dimensional network, and the fluorine-containing microcrystalline cellulose segmented polyurethane is prepared by reacting chemical microcrystalline cellulose, hydroxyl functionalized fluorine-containing substances, dihydric alcohol and diisocyanate.

Preferably, the length of the microcrystalline cellulose is 20-35 μm, the polymerization degree of the microcrystalline cellulose is 30-50, and the thickness of the PET substrate is 50-100 μm.

Preferably, the diisocyanate comprises any one of isophorone diisocyanate, dicyclohexyl methane diisocyanate and hexamethylene diisocyanate, and the diol is at least one of ethylene glycol, propylene glycol and butanediol.

The preparation method of the microcrystalline reinforced release film comprises the following specific preparation processes:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding perfluorooctanoic acid and 2-amino-2 methyl-1, 3-propylene glycol into a mixed solution of dichloromethane and ethanol, adding a condensing agent, stirring for 8-12h in a dark environment, removing the solvent by using a rotary evaporator after the reaction is finished, grinding the obtained product for 10min by using 30ml of diethyl ether, filtering, washing with diethyl ether, and drying to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving diisocyanate and dibutyltin dilaurate in a tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving the hydroxyl-functionalized fluorine-containing substance, microcrystalline cellulose and dihydric alcohol prepared in the step (1) in a tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under the nitrogen atmosphere, heating the mixture to 70 ℃ under the nitrogen atmosphere after dropwise adding, continuously stirring for reacting for 4-6h, cooling to room temperature, filtering, washing with diethyl ether, and drying to obtain the fluorine-microcrystalline cellulose block polyurethane;

(3) dissolving the fluorine-microcrystalline cellulose block polyurethane prepared in the step (2) in toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on the PET substrate subjected to plasma treatment by using a coating machine, and curing at the temperature of 120-150 ℃ for 5-8min to obtain the microcrystalline reinforced release film.

Preferably, the mass ratio of the perfluorooctanoic acid, the 2-amino-2 methyl-1, 3-propanediol and the condensing agent in the step (1) is 8-8.5:2.2-2.5: 9.5-10.

Preferably, the condensing agent in the step (1) is 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, and the volume ratio of the dichloromethane and the ethanol of the mixed solution of the dichloromethane and the ethanol is 2: 1.

Preferably, the drying conditions in the step (1) and the step (2) are drying for 18-24h in an oven at 70-80 ℃.

Preferably, in the step (2), the mass ratio of the diisocyanate, the dibutyltin dilaurate, the hydroxyl functionalized fluoride, the microcrystalline cellulose and the dihydric alcohol is 22-25:0.8:2.5-2.8:5-7: 2.8-4.

Preferably, the plasma treatment parameters in the step (3) are set as that the peak-to-peak value of the power supply voltage is set as 22kV, the frequency is 8kHz, the air gap distance is fixed as 1mm, the power density of the discharge is 24.5W/cm3, and the treatment time is 30-60 s.

Preferably, the mass-to-volume ratio of the fluorine-containing microcrystalline cellulose segmented polyurethane to the toluene in the step (3) is 2-3g:6-8ml, and the wet coating amount of the release agent in the step (3) is 5-7g/m 2.

Compared with the prior art, the method has the beneficial effects that:

(1) according to the preparation method of the microcrystal-reinforced release film, microcrystalline cellulose participates in the polymerization of polyurethane, and abundant hydroxyl groups on the surface of the microcrystalline cellulose can react with diisocyanate, so that a three-dimensional network with the microcrystalline cellulose as a chain extension base point is constructed, meanwhile, perfluorooctanoic acid is distributed on the three-dimensional network to obtain fluorine-microcrystalline cellulose segmented polyurethane, and the fluorine-microcrystalline cellulose segmented polyurethane is prepared into release liquid which is coated on a PET (polyethylene terephthalate) base material subjected to plasma treatment and cured to obtain the microcrystal-reinforced release film.

(2) According to the microcrystalline reinforced release film provided by the invention, microcrystalline cellulose is used as a cross-linking point of a three-dimensional network, so that the cross-linking density of the release agent is improved, the binding force between molecules of a composite material is increased, and the movement of a macromolecular chain is hindered, so that the thermal stability of the release agent is improved.

(3) According to the microcrystalline reinforced release film provided by the invention, the rigidity of the release film is increased due to the addition of the microcrystalline cellulose, the microcrystalline cellulose is used as a cross-linking point of a three-dimensional network, the cross-linking density of the release agent is improved, and meanwhile, the fluorine-containing organic matter participates in the polymerization of polyurethane, so that the migration phenomenon of organic silicon in the release film is avoided, the mechanical property of the release film is further enhanced, and the service life of the release film is prolonged.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A preparation method of water-based organic nano ink applied to an organic thin film device comprises the following steps:

a preparation method of a microcrystalline reinforced release film comprises the following specific preparation processes:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding 8g of perfluorooctanoic acid and 2.2g of 2-amino-2-methyl-1, 3-propanediol into 300ml of mixed solution of dichloromethane and ethanol, adding 9.5g of 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring for 8h in the dark environment, removing the solvent by using a rotary evaporator after the reaction is finished, adding 50ml of diethyl ether into the obtained product, grinding for 10min, filtering, washing with the diethyl ether, and drying in an oven at 70 ℃ for 24h to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving 11g of isophorone diisocyanate and 0.4g of dibutyltin dilaurate in 100ml of tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving 1.25g of hydroxyl functionalized fluorine-containing substance prepared in the step (1), 2.5g of microcrystalline cellulose and 1.4g of ethylene glycol in 50ml of tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under nitrogen atmosphere, heating the mixture to 70 ℃ under nitrogen atmosphere after dropwise adding, continuously stirring for reaction for 4h, cooling to room temperature, filtering, washing with 50ml of diethyl ether, and drying in an oven at 70 ℃ for 24h to obtain fluorine-containing microcrystalline cellulose block polyurethane;

(3) dissolving 10g of the fluorine-containing microcrystalline cellulose segmented polyurethane prepared in the step (2) in 30ml of toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on a PET (polyethylene terephthalate) substrate subjected to plasma treatment by using a coating machine, wherein plasma treatment parameters are set as a power supply voltage peak value of 22kV, a frequency of 8kHz, an air gap distance of 1mm, a discharge power density of 24.5W/cm3 and a treatment time of 30s, and curing at 120 ℃ for 8min to obtain the microcrystalline reinforced release film.

Example 2

A preparation method of a microcrystalline reinforced release film comprises the following specific preparation processes:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding 8.2g of perfluorooctanoic acid and 2.3g of 2-amino-2-methyl-1, 3-propanediol into 300ml of mixed solution of dichloromethane and ethanol, adding 9.7g of 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring for 10 hours in the dark, removing the solvent by using a rotary evaporator after the reaction is finished, adding 50ml of diethyl ether into the obtained product, grinding for 10 minutes, filtering, washing with the diethyl ether, and drying in an oven at 72 ℃ for 20 hours to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving 12g of dicyclohexylmethane diisocyanate and 0.4g of dibutyltin dilaurate in 100ml of tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving 1.3g of hydroxyl functionalized fluorine-containing substance prepared in the step (1), 3g of microcrystalline cellulose and 1.6g of ethylene glycol in 50ml of tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under nitrogen atmosphere, heating the mixture to 70 ℃ under nitrogen atmosphere after dropwise adding, continuously stirring for reaction for 5h, cooling to room temperature, filtering, washing with 50ml of diethyl ether, and drying in a 72 ℃ oven for 20h to obtain fluorine-containing microcrystalline cellulose block polyurethane;

(3) and (3) dissolving 12g of the fluorine-containing microcrystalline cellulose segmented polyurethane prepared in the step (2) in 35ml of toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on a PET (polyethylene terephthalate) substrate subjected to plasma treatment by using a coating machine, wherein plasma treatment parameters are set to be that the peak value of a power supply voltage is set to be 22kV, the frequency is 8kHz, the air gap distance is fixed to be 1mm, the power density of discharge is 24.5W/cm3, the treatment time is 40s, and the mixture is placed at 130 ℃ for curing for 7min to obtain the microcrystalline reinforced release film.

Example 3

A preparation method of a microcrystalline reinforced release film comprises the following specific preparation processes:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding 8.4g of perfluorooctanoic acid and 2.4g of 2-amino-2-methyl-1, 3-propanediol into 300ml of mixed solution of dichloromethane and ethanol, adding 9.8g of 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring for 10 hours in the dark, removing the solvent by using a rotary evaporator after the reaction is finished, adding 50ml of diethyl ether into the obtained product, grinding for 10 minutes, filtering, washing with the diethyl ether, and drying in an oven at 78 ℃ for 18 hours to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving 12.5g of hexamethylene diisocyanate and 0.4g of dibutyltin dilaurate in 100ml of tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving 1.4g of hydroxyl functionalized fluorine-containing substance prepared in the step (1), 3.5g of microcrystalline cellulose and 1.8g of propylene glycol in 50ml of tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A within 0.5h under a nitrogen atmosphere, heating the mixture to 70 ℃ under the nitrogen atmosphere after dropwise adding, continuously stirring for reacting for 6h, cooling to room temperature, filtering, washing with 50ml of diethyl ether, and drying in an oven at 78 ℃ for 18h to obtain the fluorine-containing microcrystalline cellulose block polyurethane;

(3) and (3) dissolving 14g of the fluorine-containing microcrystalline cellulose segmented polyurethane prepared in the step (2) in 38ml of toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on a PET (polyethylene terephthalate) substrate subjected to plasma treatment by using a coating machine, wherein plasma treatment parameters are set to be that the peak value of a power supply voltage is set to be 22kV, the frequency is 8kHz, the air gap distance is fixed to be 1mm, the power density of discharge is 24.5W/cm3, the treatment time is 50s, and the mixture is placed at 140 ℃ for curing for 6min to obtain the microcrystalline reinforced release film.

Example 4

A preparation method of a microcrystalline reinforced release film comprises the following specific preparation processes:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding 8.5g of perfluorooctanoic acid and 2.5g of 2-amino-2-methyl-1, 3-propanediol into 300ml of mixed solution of dichloromethane and ethanol, adding 10g of 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring for 12h in the dark environment, removing the solvent by using a rotary evaporator after the reaction is finished, adding 50ml of diethyl ether into the obtained product, grinding for 10min, filtering, washing with the diethyl ether, and drying in an oven at 80 ℃ for 18h to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving 12.5g of isophorone diisocyanate and 0.4g of dibutyltin dilaurate in 100ml of tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving 1.4g of hydroxyl functionalized fluorine-containing substance prepared in the step (1), 3.5g of microcrystalline cellulose and 2g of butanediol in 50ml of tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under nitrogen atmosphere, heating the mixture to 70 ℃ under nitrogen atmosphere after dropwise adding, continuously stirring for reaction for 4h, cooling to room temperature, filtering, washing with 50ml of diethyl ether, and drying in an oven at 80 ℃ for 18h to obtain fluorine-containing microcrystalline cellulose block polyurethane;

(3) and (3) dissolving 15g of the fluorine-containing microcrystalline cellulose segmented polyurethane prepared in the step (2) in 40ml of toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on a PET (polyethylene terephthalate) substrate subjected to plasma treatment by using a coating machine, wherein plasma treatment parameters are set to be that the peak value of a power supply voltage is set to be 22kV, the frequency is 8kHz, the air gap distance is fixed to be 1mm, the power density of discharge is 24.5W/cm3, the treatment time is 60s, and the mixture is placed at 150 ℃ for curing for 5min to obtain the microcrystalline reinforced release film.

Comparative example 1

A preparation method of a microcrystalline doped release film comprises the following specific preparation processes:

(1) preparation of hydroxyl functionalized fluorine-containing material: adding 8g of perfluorooctanoic acid and 2.2g of 2-amino-2 methyl-1, 3-propanediol into 300ml of mixed solution of dichloromethane and ethanol, adding 9.5g of 2-ethoxy-1-ethoxycarbonyl-1, 2-dihydroquinoline, stirring for 8-12h in the dark environment, removing the solvent by using a rotary evaporator after the reaction is finished, adding 50ml of diethyl ether into the obtained product, grinding for 10min, filtering, washing with the diethyl ether, and drying in an oven at 78 ℃ for 18h to obtain hydroxyl functionalized perfluorooctanoic acid;

(2) dissolving 11g of isophorone diisocyanate and 0.4g of dibutyltin dilaurate in 100ml of tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving 1.25g of hydroxyl functionalized fluorine-containing substance prepared in the step (1) and 1.4g of ethylene glycol in 50ml of tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under the nitrogen atmosphere, heating the mixture to 70 ℃ under the nitrogen atmosphere after dropwise adding, continuously stirring for reaction for 6h, cooling to room temperature, filtering, washing with 50ml of diethyl ether, and drying in an oven at 78 ℃ for 18h to obtain the fluorine-containing block polyurethane;

(3) dissolving 10g of the fluorine-containing block polyurethane prepared in the step (2) and 2.5g of microcrystalline cellulose in 35ml of toluene, continuously stirring to obtain a uniform release agent, uniformly coating the release agent on a PET (polyethylene terephthalate) substrate subjected to plasma treatment by using a coating machine, wherein the plasma treatment parameters are set as a power supply voltage peak value of 22kV, a frequency of 8kHz, an air gap distance of 1mm, a discharge power density of 24.5W/cm3 and a treatment time of 60s, and curing at 150 ℃ for 5min to obtain the microcrystalline doped release film.

Comparative example 2

A preparation method of a fluorine-containing release film comprises the following specific preparation processes:

(1) dissolving 8g of isophorone diisocyanate and 0.4g of dibutyltin dilaurate in 100ml of tetrahydrofuran solvent, uniformly stirring to obtain a mixed solution A, dissolving 1.4g of ethylene glycol in 20ml of tetrahydrofuran solvent contained in another reaction bottle, uniformly mixing to obtain a mixed solution B, dropwise adding the mixed solution B into the mixed solution A in 0.5h under nitrogen atmosphere, heating the mixture to 70 ℃ under nitrogen atmosphere after dropwise adding, continuously stirring for reaction for 5h, cooling to room temperature, filtering, washing with 50ml of diethyl ether, and drying in a 75 ℃ oven for 24h to obtain polyurethane;

(2) dissolving 10g of polyurethane prepared in the step (2) and perfluorooctanoic acid in 35ml of toluene, and continuously stirring to obtain a uniform release agent;

(3) uniformly coating the parting agent on the PET substrate subjected to plasma treatment by a coating machine, wherein the plasma treatment parameters are set as that the peak value of the power supply voltage is set as 22kV, the frequency is 8kHz, the air gap distance is fixed as 1mm, the power density of discharge is 24.5W/cm3, the treatment time is 50s, and curing is carried out at 130 ℃ for 6min to obtain the fluorine-containing release film.

The result of the detection

1) The method for testing the release force of the release film comprises the following steps: the release films to be tested were made into standard test specimens of 25mm x 200mm according to GB 2792-1998. The four-dimensional adhesive tape MY-2G is attached to a release film to be tested according to a standard method, the release film is rolled back and forth for 4 times by a standard compression roller, then the release film is placed for 24 hours at room temperature, a release force tester (AR-1500) is used for testing 180-degree peel strength, the testing tensile speed is 300mm/min, and the tested force is the release force.

2) The method for testing the adhesive force of the release film comprises the following steps: testing according to GB/T9286-1998 standard, marking a grid square grid on a release film sample by using a grid marking device, wherein the cutting number of each direction of a cutting pattern is 6, the interval is 2mm, each strip penetrates through a coating to a substrate, and a visual magnifier is used for checking whether the release coating falls off on the surface appearance of a cross cutting area.

The release films prepared in examples 1 to 4 and comparative examples 1 to 2 were tested to prepare standard samples of 25mm × 200mm according to the above release force and adhesion test method of the release film, and the test results are shown in table 1.

Table 1:

as can be seen from table 1, compared with the release films prepared in comparative examples 1 and 2, the release films of examples 1 to 4 have lower release force and better adhesion compared with comparative example 1, and meet the normal use requirement of the release films.

3) Mechanical testing of release films

The release films prepared in examples 1 to 4 and comparative examples 1 to 2 were used to prepare dumbbell-shaped test bars (total length 150 mm; end width 20 mm; narrow width 10 mm; narrow length 60mm) using a blade by ISO1184-1983 "Plastic-film tensile Property test method", and the tensile strength and elongation at break were measured by subjecting the sample to a tensile maximum load using a film tensile tester, the test results being shown in Table 2.

Table 2:

as can be seen from table 2, the release films of examples 1 to 4 have more excellent tensile strength and elongation at break than those of the release films prepared in comparative examples 1 and 2, and the microcrystalline reinforced release film prepared by the present invention has more excellent mechanical properties.

4) Heat stability test of Release film

The release films prepared in examples 1 to 4 and comparative examples 1 to 2 were subjected to thermodynamic tests using a thermal analyzer under a nitrogen atmosphere, 5mg was sampled, the parameters were set to a maximum temperature of 500 ℃, a temperature rise rate of 10 ℃/min, and a temperature at which the loss was 5% was T5%, and the test results are shown in table 3.

Table 3:

testing	T5％(℃)	Residual carbon amount (%)
			Example 1	238.72	20.32
Example 2	239.39	21.05
			Example 3	238.18	21.32
Example 4	238.05	20.28
			Comparative example 1	166.42	8.12
Comparative example 2	212.15	14.27

As can be seen from table 3, the release films prepared in examples and comparative example 2 both contain microcrystalline cellulose, and they have only 5% loss at above 210 ℃, and the temperature of examples 1-5 at 5% loss is above 230 ℃, while comparative example 1 starts to have 5% loss at around 166 ℃, and at 5% loss, this shows that the microcrystalline release films prepared by the present invention use microcrystalline cellulose as the crosslinking point of the three-dimensional network, which increases the crosslinking density of the release agent, increases the bonding force between the composite molecules, and hinders the movement of the large molecular chain, thereby improving the thermal stability of the release agent, and due to the addition of microcrystalline cellulose, the number of hydrogen bonds between polyurethane and microcrystalline cellulose is increased, and the hydrogen bonds in the crosslinked network interact with each other, further enhancing the thermal stability of the crosslinked network.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.