WO2022011966A1

WO2022011966A1 - Thermoplastic polyurethane elastomer film, composite film thereof, and preparation method therefor

Info

Publication number: WO2022011966A1
Application number: PCT/CN2020/137033
Authority: WO
Inventors: 金亚东; 熊斐; 周玉波; 陈兵; 朱正平
Original assignee: 宁波长阳科技股份有限公司
Priority date: 2020-07-13
Filing date: 2020-12-17
Publication date: 2022-01-20
Also published as: CN111763479B; CN111763479A

Abstract

The present application relates to a thermoplastic polyurethane elastomer film, a composite film thereof, and a preparation method therefor. The preparation method comprises: providing a thermoplastic polyurethane elastomer glue, a first release film, and a second release film; heating the thermoplastic polyurethane elastomer glue and placing same between the first release film and the second release film to obtain a preformed film layer; irradiating the first surface of the prefabricated film layer and the second surface opposite to the first surface, such that the first surface absorbs a first energy, the second surface absorbs a second energy, and the thermoplastic polyurethane elastomer glue is cured, so as to obtain a composite film; and separating the first release film and the second release film to obtain a thermoplastic polyurethane elastomer film.

Description

Thermoplastic polyurethane elastomer film and composite film and preparation method thereof

Related applications

This application claims the priority of the Chinese patent application filed on July 13, 2020, the application number is 202010670637.7, and the invention title is "thermoplastic polyurethane elastomer film and its composite film and preparation method", the entire content of which is incorporated herein by reference Applying.

technical field

The present application relates to the technical field of films, in particular to thermoplastic polyurethane elastomer films and composite films and preparation methods thereof.

Background technique

The traditional thermoplastic polyurethane elastomer film is mostly prepared by casting, that is, the raw material is plasticized and melted by an extruder, and then extruded through a T-shaped structure forming die, and cast in a sheet shape to the roller of a smoothly rotating cooling roller. On the surface of the film, the film is cooled and cooled on the cooling roller, and then the product is wound after pulling and trimming. Therefore, the production of thermoplastic polyurethane elastomer film by casting has the disadvantages of large initial equipment investment, cumbersome preparation process, low production efficiency and high energy consumption; and the thermoplastic polyurethane elastomer film obtained by casting is prone to hydrolysis resistance , heavy odor residue, poor mechanical properties and easy warping.

SUMMARY OF THE INVENTION

According to various embodiments of the present application, a method for preparing a composite membrane is provided, the method comprising the following steps:

Provide thermoplastic polyurethane elastomer glue, first release film and second release film;

heating the thermoplastic polyurethane elastomer glue, and by placing the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film to obtain a prefabricated film layer; and

By irradiating the first surface of the prefabricated film layer and the second surface disposed opposite to the first surface, the first surface absorbs the first energy, and the second surface absorbs the second energy, so that the prefabricated film layer in the thermoplastic polyurethane elastomer is cured glue, to obtain a composite film, wherein the first energy of ^{^{10mJ / cm 2 -500mJ / cm 2}} , the second energy ^{^{100mJ / cm 2 -800mJ / cm 2}} .

In one embodiment, after irradiating the first surface of the prefabricated film layer and the second surface opposite to the first surface, the first surface absorbs the first energy, and the second surface absorbs the second energy The energy steps are as follows:

The first surface of the prefabricated film layer and the second surface opposite to the first surface are sequentially irradiated, wherein the first energy is smaller than the second energy.

In one embodiment, when the first surface of the prefabricated film layer and the second surface opposite to the first surface are irradiated, the first surface absorbs the first energy, and the second surface absorbs the second energy In addition to the energy, ultraviolet rays are also used for auxiliary irradiation.

In one of the embodiments, the first energy is provided by a low pressure mercury lamp, and the second energy is provided by a high pressure mercury lamp.

In one embodiment, the time for irradiating the first surface of the prefabricated film layer is 5s-30s, and the time for irradiating the second surface of the prefabricated film layer is 5s-30s.

In one embodiment, the time for irradiating the first surface of the prefabricated film layer is longer than the time for irradiating the second surface of the prefabricated film layer.

In one embodiment, the temperature of the heated thermoplastic polyurethane elastomer glue is 30°C-90°C.

In one embodiment, the release forces of the first release film and the second release film are both 1 g-300 g.

In one embodiment, both the first release film and the second release film include one of a silicon-based release film and a fluorine release film.

In one embodiment, by placing the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film, the step of obtaining a prefabricated film layer specifically adopts a glue sticker The bonding method, wherein, the temperature difference between the bonding roller and the thermoplastic polyurethane elastomer glue is less than or equal to 5°C in the process of the glue-drop bonding.

According to various embodiments of the present application, there is also provided a composite film obtained by the preparation method, wherein the composite film includes a thermoplastic polyurethane elastomer film and a first thermoplastic polyurethane elastomer film attached to the opposite surface of the thermoplastic polyurethane elastomer film. Release film and second release film.

The application also relates to a preparation method of a thermoplastic polyurethane elastomer film, comprising:

providing the composite membrane;

The first release film and the second release film in the composite film are separated to obtain a thermoplastic polyurethane elastomer film.

The present application also relates to a thermoplastic polyurethane elastomer film obtained by the preparation method, wherein the thickness of the thermoplastic polyurethane elastomer film is 5 μm-200 μm.

In the preparation method of the above-mentioned composite film, by making the energy absorbed by the first surface and the second surface cooperate with each other, the thermoplastic polyurethane elastomer glue in the prefabricated film layer is urged to be cured at a uniform speed to form a film, and the internal reaction of the film is sufficient and the degree of reaction is the same, so that the The thermoplastic polyurethane elastomer film in the obtained composite film has excellent hydrolysis resistance and mechanical properties, is not easy to warp, has a uniform thickness, and has no or little residual odor.

At the same time, in the present application, thermoplastic polyurethane elastomer glue is formed between the first release film and the second release film for curing to prepare a composite film, and then the first release film and the second release film in the composite film are separated, namely The thermoplastic polyurethane elastomer film can be obtained. Compared with the casting method, the method is simple, the equipment investment can be greatly reduced, and the production efficiency is high and can be low.

detailed description

The thermoplastic polyurethane elastomer film and the composite film and the preparation method thereof provided by the present invention will be further described below.

The preparation method of the composite membrane provided by the present invention comprises:

S11: Provide thermoplastic polyurethane elastomer glue, first release film and second release film;

S12: heating the thermoplastic polyurethane elastomer glue, and placing the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film to obtain a prefabricated film layer;

S13: By irradiating the first surface of the prefabricated film layer and the second surface disposed opposite to the first surface, the first surface absorbs the first energy, and the second surface absorbs the second energy, so that the prefabricated film layer the thermoplastic polyurethane elastomer film layer of glue is cured to obtain a composite film, wherein the first energy of ^{^{10mJ / cm 2 -500mJ / cm 2}} , the second energy 100mJ / cm ² -800mJ / cm ² .

In step S11, the thermoplastic polyurethane elastomer glue preferably uses a solvent-free thermoplastic polyurethane elastomer glue, so as to ensure that the thermoplastic polyurethane elastomer film does not have residual solvent odor.

Since the thermoplastic polyurethane elastomer glue will form adhesion with the contact release film after curing, in order to facilitate the peeling of the intermediate thermoplastic polyurethane elastomer film, it is necessary to separate the first release film and the second release film to be used. Type force is optimized. When the release force of the release film is too large, the release film is not easy to tear off, and it is easy to cause damage to the thermoplastic polyurethane elastomer film; when the release force of the release film is too small, the release film is easy to peel off automatically, so , the release force of the first release film and the second release film is preferably 1g-300g, more preferably 1g-100g, more preferably 3g-10g.

Specifically, both the first release film and the second release film include one of a silicon-based release film and a fluorine release film, and the thicknesses of the first release film and the second release film are preferably 50μm-75μm.

In step S12, in order to ensure that the thickness of the thermoplastic polyurethane elastomer film after curing of the thermoplastic polyurethane elastomer glue has a small deviation from the target value, and the thickness is uniform, the temperature of the heated thermoplastic polyurethane elastomer glue is preferably 30 ℃-90 ℃, More preferably, it is 40 degreeC - 80 degreeC, More preferably, it is 60 degreeC - 80 degreeC.

The way of placing the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film is not limited, including coating, coating, spraying, and the like. In the present invention, the heated thermoplastic polyurethane elastomer glue is preferably applied between the first release film and the second release film by means of glue-dropping.

In the process of adhering the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film by means of glue sticking, preferably the heated thermoplastic polyurethane elastomer glue and the laminating roller The temperature difference does not exceed 5 °C, so as to ensure the thickness stability and appearance stability of the thermoplastic polyurethane elastomer glue during processing.

In step S13, in the process of curing the thermoplastic polyurethane elastomer glue in the prefabricated film layer, if the energy required for curing the thermoplastic polyurethane elastomer glue is insufficient, some of the thermoplastic polyurethane elastomer glue will be insufficiently reacted and cannot be completely cured. Film formation, the mechanical properties and hydrolysis resistance of the thermoplastic polyurethane elastomer film will also be greatly reduced, and the residual unreacted part will have residual odor. If the energy required for curing the thermoplastic polyurethane elastomer glue is too high, the curing speed of the thermoplastic polyurethane elastomer glue will be too fast, and the shrinkage will be severe, resulting in obvious warpage of the cured thermoplastic polyurethane elastomer film.

Therefore, the present invention allows the first surface of the prefabricated film layer to absorb ^{a first energy of 10mJ/cm 2} -500mJ/cm ² , and the second surface facing away from the first surface absorbs a second energy of 100mJ/cm ² -800mJ/cm ² energy. By making the first surface and the second surface of the prefabricated film layer cooperate with each other to absorb energy, the thermoplastic polyurethane elastomer glue in the prefabricated film layer is promoted to cure at a uniform speed to form a film, and the internal reaction of the film is sufficient and the degree of reaction is the same, so as to obtain excellent hydrolysis resistance. As well as mechanical properties, it is not easy to warp, the thickness is uniform, and the thermoplastic polyurethane elastomer film has no or little residual odor.

Further, the first energy is ^{50mJ/cm 2} -350mJ/cm ² , and the second energy is 300mJ/cm ² -600mJ/cm ² .

There are three ways to make the first surface of the prefabricated film absorb the first energy and the second surface to absorb the second energy, the first one: make the first surface of the prefabricated film absorb the first energy, and at the same time, The second surface absorbs the second energy; the second type: sequentially causes the second surface of the prefabricated film layer to absorb the second energy, and the first surface absorbs the first energy; the third type: sequentially causes the first surface of the prefabricated film layer to absorb the first energy The surface absorbs the first energy and the second surface absorbs the second energy.

Considering that in the first method, the prefabricated film layer receives the first energy and the second energy at the same time, it is also possible that the curing reaction speed of the thermoplastic polyurethane elastomer glue is too fast, resulting in the warpage of the thermoplastic polyurethane elastomer film. Therefore, the manner in which the first surface of the prefabricated film layer absorbs the first energy and the second surface absorbs the second energy can be selected from the second manner or the third manner.

Further, in the second method, high-energy irradiation is used at the beginning to carry out a high-intensity curing reaction, and the lack of transition may also cause the thermoplastic polyurethane elastomer film to warp; and in the third method, the The first surface of the prefabricated film layer absorbs the first energy, the second surface away from the first surface absorbs the second energy, the curing reaction is gradually carried out from low strength to high strength, the thermoplastic polyurethane elastomer glue is uniformly cured to form a film, and the inside of the film When the reaction is sufficient and the degree of reaction is the same, it is possible to obtain a thermoplastic polyurethane elastomer film with excellent hydrolysis resistance and mechanical properties, not easy to warp, uniform thickness, and no residual odor or less residual odor. Therefore, it is preferable to make the first surface of the prefabricated film layer absorb the first energy and the second surface to absorb the second energy, and the first energy is smaller than the second energy.

Further, since the first energy is less than the second energy, in order to ensure the balance of the energy received by the first surface and the second surface, the time for the first surface to absorb the first energy is longer than the time for the second surface to absorb the first energy. Second energy time.

Meanwhile, in order to ensure the curing effect of the thermoplastic polyurethane elastomer glue, the time for irradiating the first surface of the prefabricated film layer is preferably 5s-30s, more preferably 10s-20s, and the time for irradiating the second surface of the prefabricated film layer is Preferably it is 5s-30s, More preferably, it is 5s-15s.

Considering that ultraviolet rays have a certain penetrating effect, through the penetration of ultraviolet rays and the mutual cooperation of receiving energy, the curing effect of the thermoplastic polyurethane elastomer glue is better, and the thermoplastic polyurethane elastic film with better hydrolysis resistance and mechanical properties can be obtained. And less warpage, less residual odor or no odor residue. Therefore, when the first surface of the prefabricated film layer and the second surface disposed opposite to the first surface are irradiated, the first surface absorbs the first energy, and the second surface absorbs the second energy at the same time. Auxiliary irradiation with ultraviolet light.

Further, the low-pressure mercury lamp and the high-pressure mercury lamp can simultaneously provide the required energy and ultraviolet rays with certain penetrating performance, so the first energy is preferably provided by the low-pressure mercury lamp, and the second energy is preferably provided by the high-pressure mercury lamp. .

It should be noted that the low-pressure mercury lamp in the present invention refers to a mercury vapor pressure of 1.3Pa-13Pa (0.01mmHg-0.1mmHg), a main emission wavelength of 253.7nm (0.01mmHg) in the ultraviolet region, and an equivalent energy of 471.0kJ/ mol (112.5kcal/mol), a mercury vapor arc lamp that accounts for 70% of the total energy of the lamp. High-pressure mercury lamp refers to a mercury vapor arc lamp with a mercury vapor pressure of 51kPa-507kPa, a main emission wavelength of 365.0nm, and an equivalent energy of 327.3kJ/mol.

Specifically, the low-pressure mercury lamp and the high-pressure mercury lamp consist of adjustable UV lamps.

The present invention also provides a composite film, comprising a thermoplastic polyurethane elastomer film and a first release film and a second release film attached to the opposite surfaces of the thermoplastic polyurethane elastomer film.

In the composite film of the present invention, the thermoplastic polyurethane elastomer film has sufficient internal reaction and the same degree of reaction, has excellent hydrolysis resistance and mechanical properties, is not easy to warp, has a uniform thickness, and has no or little residual odor.

The present invention also provides a preparation method of the thermoplastic polyurethane elastomer film, comprising:

S21: provide the composite membrane;

S22: Separate the first release film and the second release film in the composite film to obtain a thermoplastic polyurethane elastomer film.

In the present invention, the thermoplastic polyurethane elastomer glue is formed between the first release film and the second release film for curing to prepare the composite film, and then the first release film and the second release film in the composite film are separated, so that Compared with the casting method, the thermoplastic polyurethane elastomer film is obtained, the method is simple, the investment in equipment can be greatly reduced, and the production efficiency is high and can be low.

The present invention also provides a thermoplastic polyurethane elastomer film, which is obtained by the preparation method and has a thickness of 5 μm-200 μm.

The thermoplastic polyurethane elastomer film prepared by the invention has excellent hydrolysis resistance and mechanical properties, is not easy to warp, has a uniform thickness, and has no residual smell or little residual smell. It can be used in automobiles, mobile phones and other products, such as high value-added products such as car coat film, car interior, mobile phone back cover, 3D curved protective film, etc.

Hereinafter, the thermoplastic polyurethane elastomer film and its composite film and preparation method will be further described by the following specific examples.

Example 1

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 40 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film and the second release film are both silicon-based release films, with a thickness of 50 μm and a release force of 3 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a bonding roller at 40 ° C to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 20s to ensure that the first energy absorbed by the first surface is 50mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 15s to ensure that the second surface The second energy absorbed is 300 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer is cured to obtain a composite film.

Example 2

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 50 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film and the second release film are both fluorine release films with a thickness of 50 μm and a release force of 10 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a laminating roller at 50 ° C to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 20s to ensure that the first energy absorbed by the first surface is 100mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 10s to ensure that the second surface The second energy absorbed was 350 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 3

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 60 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue-dipping. The release film and the second release film are both silicon-based release films with a thickness of 50 μm and a release force of 5 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a bonding roller at 60° C. to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 20s to ensure that the first energy absorbed by the first surface is 150mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 10s to ensure that the second surface The second energy absorbed was 400 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 4

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 70 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film and the second release film are both fluorine release films with a thickness of 50 μm and a release force of 5 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a laminating roller at 70 ° C to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 15s to ensure that the first energy absorbed by the first surface is 200mJ/cm ² , and then irradiate the second surface away from the first surface with a high-pressure mercury lamp for 10s to ensure that the second surface The second energy absorbed was 450 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 5

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 80 ° C, drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue-dropping. The release film and the second release film are both silicon-based release films with a thickness of 50 μm and a release force of 5 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a laminating roller at 80° C. to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low pressure mercury lamp for 15s to ensure that the first energy absorbed by the first surface is 250mJ/cm ² , and then use a high pressure mercury lamp to illuminate the second surface away from the first surface for 5s to ensure that the second surface The second energy absorbed was 500 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 6

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 90 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film and the second release film are both silicon-based release films, with a thickness of 50 μm and a release force of 5 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a bonding roller at 90 ° C to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low pressure mercury lamp for 10s to ensure that the first energy absorbed by the first surface is 300mJ/cm ² , and then use a high pressure mercury lamp to illuminate the second surface away from the first surface for 5s to ensure that the second surface The second energy absorbed was 550 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 7

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 70 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film and the second release film are both silicon-based release films with a thickness of 50 μm and a release force of 5 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a laminating roller at 70° C. to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 10s to ensure that the first energy absorbed by the first surface is 350mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 5s to ensure that the second surface The second energy absorbed was 600 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 8

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 15s to ensure that the first energy absorbed by the first surface is 350mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 10s to ensure that the second surface The second energy absorbed was 600 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 9

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 20s to ensure that the first energy absorbed by the first surface is 350mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 15s to ensure that the second surface The second energy absorbed was 600 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 10

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 20s to ensure that the first energy absorbed by the first surface is 250 mJ/cm ² . The second energy absorbed by the surface is 500 mJ/cm ² , so that the thermoplastic polyurethane elastomer glue in the prefabricated film layer is cured to obtain a composite film.

Example 11

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 80 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film and the second release film are both silicon-based release films with a thickness of 50 μm and a release force of 5 g, and the thermoplastic polyurethane elastomer glue is extruded to a thickness of 150 μm with a laminating roller at 80° C. to obtain a prefabricated film Floor.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 10s to ensure that the first energy absorbed by the first surface is 50mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 5s to ensure that the second surface The second energy absorbed is 300 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer is cured to obtain a composite film.

Example 12

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 30 ° C, and drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue sticking. The release film is a silicon-based release film, the release force of the first release film is 1g, the thickness of the first release film is 50 μm, the second release film is a fluorine-based release film, and the thickness of the second release film is 1 g. The release force was 2 g, the thickness of the second release film was 70 μm, and the thermoplastic polyurethane elastomer glue was extruded to a thickness of 5 μm with a bonding roller at 30° C. to obtain a prefabricated film layer.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 5s to ensure that the first energy absorbed by the first surface is 500mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 30s to ensure that the second surface The second energy absorbed is 100 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer is cured to obtain a composite film.

Example 13

Provide solvent-free thermoplastic polyurethane elastomer glue and heat it to 80 ° C, drop the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film in the form of glue-dropping. The release film is a fluorine release film, the release force of the first release film is 270g, the thickness of the first release film is 75 μm, the second release film is a silicon-based release film, and the second release film is The release force was 300 g, the thickness of the second release film was 55 μm, and the thermoplastic polyurethane elastomer glue was extruded to a thickness of 200 μm with a bonding roller at 80° C. to obtain a prefabricated film layer.

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 30s to ensure that the first energy absorbed by the first surface is 10mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 5s to ensure that the second surface The second energy absorbed was 800 mJ/cm ² , which cured the thermoplastic polyurethane elastomer glue in the prefabricated film layer to obtain a composite film.

Example 14

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 15s to ensure that the first energy absorbed by the first surface is 350mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 8s to ensure that the second surface The second energy absorbed was 600 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Example 15

Irradiate the first surface of the prefabricated film layer with a low-pressure mercury lamp for 12s to ensure that the first energy absorbed by the first surface is 350mJ/cm ² , and then use a high-pressure mercury lamp to illuminate the second surface away from the first surface for 10s to ensure that the second surface The second energy absorbed was 600 mJ/cm ² , and the thermoplastic polyurethane elastomer glue in the prefabricated film layer was cured to obtain a composite film.

Comparative Example 1

Provide a coating solution in which thermoplastic polyurethane elastomer glue and methyl ethyl ketone are mixed in a mass ratio of 1:4, and a release film with a thickness of 50 μm and a release force of 5 g.

The coating liquid is uniformly coated on the surface of the release film through a slit coating head, and all the solvent in the coating liquid is dried in an oven to separate the release film to obtain a thermoplastic polyurethane elastomer film.

The thermoplastic polyurethane elastomer films of Examples 1-15 and Comparative Example 1 were tested for performance, and the results are shown in Table 1.

Among them, the odor evaluation method: 10mm from the thermoplastic polyurethane elastomer film surface to smell the odor judgment degree, and the odor degree is divided into serious, heavy, slight, and none.

Evaluation method of hydrolysis resistance: Cut the thermoplastic polyurethane elastomer film into a sample of 100mm*100mm, put it in water with a temperature of 80 ° C, soak it for 30 minutes and take it out. The degree of damage: intact, deformed, and melted.

Warpage evaluation method: Cut the sample into 200mm*200mm samples, place them on a marble platform, measure the height of the four corners from the table with a steel ruler, and take the average as the warpage data.

The test method of the first energy and the second energy: use the tester of the model MICROCURE DATAREADER produced by EIT Instruments Calibration Services for testing.

Test method for the release force of the first release film and the second release film: use a computer-controlled electronic universal material testing machine model CTM8010 produced by Xieqiang Instrument Manufacturing (Shanghai) Co., Ltd. for testing. The test method of the release force of the first release film and the second release film is carried out in accordance with the GB/T 25256-2010 standard.

Table 1

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

A method for preparing a composite membrane, comprising:

Provide thermoplastic polyurethane elastomer glue, first release film and second release film;

heating the thermoplastic polyurethane elastomer glue, and by placing the heated thermoplastic polyurethane elastomer glue between the first release film and the second release film to obtain a prefabricated film layer; and

By irradiating the first surface of the prefabricated film layer and the second surface disposed opposite to the first surface, the first surface absorbs the first energy, and the second surface absorbs the second energy, so that the prefabricated film layer in the thermoplastic polyurethane elastomer is cured glue, to obtain a composite film, wherein the first energy of 10mJ / cm 2 -500mJ / cm 2 , the second energy 100mJ / cm 2 -800mJ / cm 2 .
The preparation method of the composite film according to claim 1, wherein, by irradiating the first surface of the prefabricated film layer and the second surface opposite to the first surface, the first surface is made to absorb the first surface. energy, and the step of absorbing the second energy by the second surface is as follows:

The first surface of the prefabricated film layer and the second surface opposite to the first surface are sequentially irradiated, wherein the first energy is smaller than the second energy.
The method for preparing a composite film according to claim 1, wherein when the first surface of the prefabricated film layer and the second surface disposed opposite to the first surface are irradiated, the first surface is made to absorb the first surface. When the second surface absorbs the second energy, it also uses ultraviolet rays for auxiliary irradiation.
The method for preparing a composite film according to claim 3, wherein the first energy is provided by a low-pressure mercury lamp, and the second energy is provided by a high-pressure mercury lamp.
The preparation method of the composite film according to claim 1, wherein the time for irradiating the first surface of the prefabricated film layer is 5s-30s, and the time for irradiating the second surface of the prefabricated film layer is 5s-30s .
The method for preparing a composite film according to claim 1, wherein the time for irradiating the first surface of the prefabricated film layer is longer than the time for irradiating the second surface of the prefabricated film layer.
The method for preparing a composite film according to claim 1, wherein the temperature of the heated thermoplastic polyurethane elastomer glue is 30°C-90°C.
The preparation method of the composite film according to claim 1, wherein the release force of the first release film and the second release film are both 1g-300g.
The method for preparing a composite film according to claim 1, wherein the first release film and the second release film both comprise one of a silicon-based release film and a fluorine release film.
The method for preparing a composite film according to claim 1, wherein the heated thermoplastic polyurethane elastomer glue is placed between the first release film and the second release film to obtain The step of prefabricating the film layer specifically adopts the method of glue drop lamination, wherein the temperature difference between the lamination roller and the thermoplastic polyurethane elastomer glue during the glue drop lamination process is less than or equal to 5°C.
A composite film, characterized in that, obtained by the preparation method according to any one of claims 1-10, the composite film comprises a thermoplastic polyurethane elastomer film and a first thermoplastic polyurethane elastomer film attached to the opposite surface of the thermoplastic polyurethane elastomer film. A release film and a second release film.
A preparation method of thermoplastic polyurethane elastomer film, characterized in that, comprising:

providing the composite membrane of claim 11;

The first release film and the second release film in the composite film are separated to obtain a thermoplastic polyurethane elastomer film.
A thermoplastic polyurethane elastomer film, characterized in that, obtained by the preparation method according to claim 12 , and the thickness of the thermoplastic polyurethane elastomer film is 5 μm-200 μm.