Polysulfone film and preparation method therefor

Abstract

Disclosed in the present invention are a polysulfone film and a preparation method therefor. The polysulfone film has a thickness of 25-250 μm, and comprises a polysulfone polymer, a reinforcing agent, a mobile phase aid, and an ultraviolet absorbent. The polysulfone film is obtained by means of processes of blending and pelletization, and cast film extrusion. In the present invention, the polysulfone polymer is blended with the reinforcing agent and the flow aid, so that the mobile phase and strength of the polysulfone polymer are improved, film formation is facilitated, and the light transmittance is not affected; and then the ultraviolet absorbent is added, so that the long-term ultraviolet resistance can be effectively improved. The polysulfone film of the present invention can be realized by means of the processes such as blending and pelletization, cast film extrusion and the like, the process steps are simple, and wide application is facilitated.

Description

A polysulfone film and its preparation method Technical Field

[0001] The present invention relates to the field of new material films, and in particular to a polysulfone film and a preparation method thereof. Background Art

[0002] Polysulfone polymer material (PSU) is a special engineering plastic with excellent mechanical properties and flame retardant characteristics. It also has the characteristics of high temperature resistance, high modulus, corrosion resistance, and high-temperature water vapor resistance. It is widely used in high-end fields such as electronics, aerospace, etc., and the long-term use temperature range is -100°C to 180°C.

[0003] However, PSU and its derivatives PESU (polyethersulfone) and PPSU (polyphenylsulfone) are all amorphous polymer materials. Although they have low melting points (within the range of 180°C-240°C), they have poor fluidity, with an initial flow temperature of approximately 300°C, which is not conducive to the preparation of thin films, thus limiting their scope of application. In addition, although sulfone polymer materials have many excellent properties, they are not UV-resistant and will age under long-term UV exposure, resulting in performance degradation and color changes. Summary of the Invention

[0004] The first technical problem to be solved by the present invention is to provide a polysulfone film, which broadens the application range of polysulfone polymers.

[0005] In order to solve the above technical problems, the present invention provides a polysulfone film having a thickness of 25-250 μm, which comprises the following components:

[0006] Polysulfone polymer: 75-120 parts by weight, preferably 100 parts by weight;

[0007] Enhancer: 0.5-0.75 parts by weight, preferably 0.5 parts by weight;

[0008] Flowability aid: 0.2-0.35 parts by weight, preferably 0.25 parts by weight;

[0009] Ultraviolet absorber: 0.75-2.5 parts by weight.

[0010] Preferably, the polysulfone polymer is selected from PSU, PESU or PPSU.

[0011] Preferably, the reinforcing agent is silica particles with a particle size of 50-100 nm. Other reinforcing agents may affect the light transmittance of the film, and therefore, silica particles are preferred.

[0012] The fluidity aid is SiC powder with a particle size of 2-5 μm. Other fluidity aids are easily volatilized during the preparation process and thus cannot play a role, or require a larger addition amount to play a role. However, a larger addition amount will affect the performance of the film. Therefore, SiC powder is preferred.

[0013] Preferably, the film has the following properties:

[0014] Tensile strength CD: 77.8-85.9 MPa;

[0015] Tensile strength MD: 78.4-87.3MPa;

[0016] UV blocking rate: 90%;

[0017] At 180°C, the thermal shrinkage after heating for 30 minutes is -1.10% to -1.35%;

[0018] Light transmittance: 85%-92%;

[0019] Dyne value: 40-46.

[0020] The second technical problem to be solved by the present invention is to provide a method for preparing a polysulfone film, thereby realizing the formation of polysulfone polymer films.

[0021] In order to solve the above technical problems, the present invention provides a method for preparing a polysulfone film, comprising the following steps:

[0022] Step S1. The polysulfone polymer, the reinforcing agent, the mobile phase additive and the ultraviolet absorber are blended and granulated using a twin-screw blending and granulation equipment to obtain modified particles;

[0023] Step S2: After heat treatment, the modified particles in step S1 are added to a high-temperature extruder to obtain a film through a cast extrusion process.

[0024] Preferably, the contents of the components in step S1 are as follows:

[0025] Polysulfone polymer: 75-120 parts by weight, preferably 100 parts by weight;

[0026] Enhancer: 0.5-0.75 parts by weight, preferably 0.5 parts by weight;

[0027] Flowability aid: 0.2-0.35 parts by weight, preferably 0.25 parts by weight;

[0028] Ultraviolet absorber: 0.75-2.5 parts by weight;

[0029] Wherein, the polysulfone polymer is selected from PSU, PESU or PPSU;

[0030] The reinforcing agent is silicon dioxide particles with a particle size of 50-100 nm;

[0031] The fluidity aid is SiC micropowder with a particle size of 2-5 μm.

[0032] Preferably, the temperature of the blending and granulation in step S1 is 220°C-300°C.

[0033] Preferably, in step S2, the heat treatment temperature is 150° C. and the heat treatment time is 4 hours.

[0034] Preferably, in step S2, the extrusion temperature of the cast extrusion process is 300°C-390°C.

[0035] Preferably, the method for preparing the polysulfone film further comprises the following steps:

[0036] Step S3. The film obtained in step S2 is cooled in a temperature gradient of 220° C., 200° C., 180° C., 150° C., 120° C., and 90° C. in sequence to obtain a polysulfone film with a thickness of 25-250 μm.

[0037] The present invention improves the mobile phase and strength of the polysulfone polymer by blending it with a reinforcing agent and a fluidity aid, thereby facilitating film formation while maintaining light transmittance. Furthermore, the addition of an ultraviolet absorber can effectively improve long-term ultraviolet resistance. The polysulfone film of the present invention can be produced through processes such as blending granulation and cast extrusion film formation, with simple process steps and convenient for wide application. DETAILED DESCRIPTION

[0038] The following is a clear and complete description of the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0039] Example 1 General steps for preparing polysulfone membrane

[0040] Step S1: using a twin-screw blending and granulating device to blend and granulate polysulfone polymer, silicon dioxide, SiC and ultraviolet absorber at 220° C.-300° C. to obtain modified particles;

[0041] The content of each component is as follows:

[0042] Polysulfone polymer: 75-120 parts by weight;

[0043] Enhancer: 0.5-0.75 parts by weight;

[0044] Flowability aid: 0.2-0.35 parts by weight;

[0045] Ultraviolet absorber: 0.75-2.5 parts by weight;

[0046] Wherein, the polysulfone polymer is selected from PSU, PESU or PPSU;

[0047] The reinforcing agent is silicon dioxide particles with a particle size of 50-100 nm;

[0048] The fluidity aid is SiC micropowder with a particle size of 2-5 μm.

[0049] Step S2: heat-treating the modified particles in step S1 at 150° C. for 4 h, adding the particles to a high-temperature extruder, and obtaining a film by a cast extrusion process;

[0050] The extrusion temperature of the cast extrusion process is 300°C-390°C.

[0051] Step S3. The film obtained in step S2 is cooled in a temperature gradient of 220° C., 200° C., 180° C., 150° C., 120° C., and 90° C. in sequence to obtain a polysulfone film with a thickness of 25-250 μm. Example

[0052] Polysulfone membranes were prepared according to the method of Example 1. The properties of the different components are shown in Table 1. The content of each component in the experimental group is presented in parts by weight, so the weight unit is not given:

[0053] Table 1 List of different components of the polysulfone membrane of the present invention and their membrane properties

[0054]

[0055] Example 3 Comparative Example

[0056] A polysulfone film was prepared according to the method of Example 1 as a control group. In the control group, the only difference between the components and those in Example 1 was the content. In the control group, the content of each component is presented in parts by weight. The components and corresponding properties of the control group are shown in Table 2, so the weight units are not given.

[0057] Table 2 List of different components and film properties of the control group polysulfone film

[0058]

[0059] In the control groups 1-3, the amount of UV absorber added was adjusted. When the added amount was less than 0.75 parts by weight, the UV blocking effect became worse. When the added amount was increased to 3 parts by weight, although the UV blocking rate was improved compared to the 2.5 addition amount, it was found during the thermal shrinkage experiment that the precipitates on the film surface were serious, which would seriously affect the continuous production of extrusion.

[0060] In the control group 4-5, the addition amount of SiC micropowder was adjusted. When the addition amount reached 0.5 parts by weight, holes appeared on the surface of the produced film, and the strength and transmittance of the film also decreased. It is speculated that the increase in the addition amount may lead to poor compatibility, affecting continuous production.

[0061] In control groups 6-8, the amount of silicon dioxide added was adjusted. When the addition amount reached 0.75 parts by weight, the strength of the film did not increase significantly. The marginal effect of continued addition weakened, increasing the production cost. After continuing to add to 1 part by weight, the strength of the film began to decrease, and the light transmittance also began to decrease. After continuing to increase to 2 parts by weight, the light transmittance and strength of the film continued to decrease, and holes appeared on the surface of the film, affecting continuous production.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A polysulfone film, characterized in that The film has a thickness of 25-250 μm and comprises the following components: Polysulfone polymer: 75-120 parts by weight; Enhancer: 0.5-0.75 parts by weight; Flowability aid: 0.2-0.35 parts by weight; Ultraviolet light absorber: 0.75-2.5 parts by weight.

2. The polysulfone membrane according to claim 1, characterized in that The polysulfone polymer is selected from PSU, PESU or PPSU.

3. The polysulfone membrane according to claim 1, characterized in that The reinforcing agent is silicon dioxide particles with a particle size of 50-100 nm; The fluidity aid is SiC powder with a particle size of 2-5 μm.

4. The polysulfone membrane according to claim 1, characterized in that The film has the following properties: Tensile strength CD: 77.8-85.9 MPa; Tensile strength MD: 78.4-87.3MPa; UV blocking rate: 90%; At 180°C, the thermal shrinkage rate after heating for 30 minutes is -1.10% to -1.35%; Light transmittance: 85%-92%; Dyne value: 40-46.

5. A method for preparing the polysulfone film according to any one of claims 1 to 4, characterized in that: The steps include: Step S1. The polysulfone polymer, the reinforcing agent, the mobile phase aid and the ultraviolet absorber are blended and granulated by a twin-screw blending and granulation equipment to obtain modified particles; Step S2: After the modified particles in step S1 are heat-treated, they are added to a high-temperature extruder to obtain a film through a cast extrusion process.

6. The preparation method according to claim 5, characterized in that: The contents of the components in step S1 are as follows: Polysulfone polymer: 75-120 parts by weight; Enhancer: 0.5-0.75 parts by weight; Flowability aid: 0.2-0.35 parts by weight; Ultraviolet light absorber: 0.75-2.5 parts by weight; Wherein, the polysulfone polymer is selected from PSU, PESU or PPSU; The reinforcing agent is silicon dioxide particles with a particle size of 50-100 nm; The fluidity aid is SiC powder with a particle size of 2-5 μm.

7. The preparation method according to claim 6, characterized in that: The temperature of the blending and granulation in step S1 is 220°C-300°C.

8. The preparation method according to claim 5, characterized in that: In step S2, the heat treatment temperature is 150° C. and the heat treatment time is 4 hours.

9. The preparation method according to claim 5, characterized in that: In the step S2, the extrusion temperature of the cast extrusion process is 300°C-390°C.

10. The preparation method according to claim 5, characterized in that: The preparation method of the polysulfone film also includes the following steps: Step S3. The film obtained in step S2 is cooled at a temperature gradient of 220° C., 200° C., 180° C., 150° C., 120° C., and 90° C. in sequence to obtain a polysulfone film with a thickness of 25-250 μm.

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