A three-layer co-extruded PSU film and its preparation method

Abstract

This application discloses a three-layer co-extruded PSU film and its preparation method, belonging to the field of polymer film materials. The three-layer co-extruded PSU film comprises a PSU layer and two modified PSU layers, with the PSU layer disposed between the two modified PSU layers. The modified PSU layers are prepared from the following raw materials in parts by weight: 100 parts PSU resin; 3-4.5 parts modified glass powder; and 0.7-1.2 parts antioxidant. The modified glass powder is obtained by attaching the PESU resin to the surface of the glass powder. This application has the advantage of improving the PSU film's resistance to UV aging.

Description

Technical Field

[0001] The present application relates to the field of polymer film materials, and in particular to a three-layer co-extruded PSU film and a preparation method thereof. Background Art

[0002] Polysulfone is a type of aromatic, non-crystalline, high-performance thermoplastic engineering plastic containing sulfone groups in its molecular backbone. Common polysulfones include PESU, PSU, and PPSU. PESU refers to polyethersulfone, PSU refers to bisphenol A polysulfone, and PPSU refers to polyphenylsulfone.

[0003] Bisphenol A polysulfone (PSU) is made from bisphenol A and 4,4'-dichlorodiphenyl sulfone via a polycondensation reaction. Bisphenol A polysulfone (PSU) exhibits excellent mechanical properties, particularly at high temperatures, where mechanical property retention is high. Therefore, it is suitable for applications in electronics and electrical applications that require miniaturization, lightweighting, and high-temperature resistance.

[0004] However, in more severe environments, such as those with strong ultraviolet rays, PSU is prone to aging, especially for PSU membranes made into film materials, the application effect is poor. Summary of the Invention

[0005] In order to improve the UV aging resistance of the PSU film, the present application provides a three-layer co-extruded PSU film and a preparation method thereof.

[0006] In the first aspect, the present application provides a three-layer co-extruded PSU film using the following technical solutions:

[0007] A three-layer co-extruded PSU film comprises a PSU layer and two modified PSU layers, wherein the PSU layer is disposed between the two modified PSU layers, and the modified PSU layer is prepared from raw materials comprising the following parts by weight:

[0008] 100 parts of PSU resin;

[0009] 3-4.5 parts of modified glass powder;

[0010] 0.7-1.2 parts of antioxidant;

[0011] The modified glass powder is obtained by attaching PESU resin to the surface of the glass powder.

[0012] By adopting the above technical solution, the glass powder has good ability to absorb and scatter ultraviolet rays. By adding glass powder to the modified PSU layer, the modified PSU layer can block ultraviolet rays, which can improve the ultraviolet resistance of the PSU film. In addition, glass powder is only added to the two layers on the surface of the PSU film. The middle PSU layer effectively maintains the mechanical properties of the PSU film, making the overall performance of the PSU film more excellent.

[0013] The modified glass powder obtained by precipitating and adhering PESU resin to the surface of the glass powder has increased interfacial bonding strength with the PSU resin, reduced glass powder agglomeration, improved the dispersion uniformity of the glass powder, and further improved the UV resistance and mechanical properties of the PSU film. The dispersed modified glass powder has little effect on the transmittance of the PSU film.

[0014] Optionally, the raw materials for preparing the modified glass powder include glass powder, PESU resin, ether, water and dimethylacetamide, and the mass ratio of the glass powder, PESU resin, ether, water and dimethylacetamide is 1:(0.1-0.25):(3-5):(6-10):(2-4).

[0015] By adopting the above technical solution, the PESU resin has a similar structure to the PSU resin, which improves the compatibility of the surface of the modified glass powder and the PSU resin matrix, thereby improving the interfacial bonding strength between the two. In addition, the PESU resin has good flexibility, which promotes the intercalation of the modified glass powder surface and the PSU resin, thereby maintaining the good mechanical properties of the PSU film.

[0016] Optionally, the modified glass powder is prepared by dissolving PESU resin in dimethylacetamide, then adding glass powder to dimethylacetamide, first adding ether dropwise, stirring evenly, then adding water dropwise, stirring evenly, and separating to obtain the modified glass powder.

[0017] By adopting the above technical solution, the polarity differences among ether, water and dimethylacetamide and their solubility differences for PESU are utilized. Ether causes PESU to gradually precipitate and adhere to the surface of the glass powder, while water promotes the stable adhesion of PESU, thereby obtaining a modified glass powder.

[0018] Optionally, the glass powder has a particle size of 1 to 5 μm.

[0019] By adopting the above technical solution, the glass powder has better transparency, controls the particle size of the glass powder, promotes the full dispersion of the glass powder, and exerts the ability to absorb and scatter ultraviolet rays.

[0020] Optionally, the molecular weight of the PSU resin is 78,000 to 84,000.

[0021] Optionally, the molecular weight of the PESU resin is 45,000 to 51,000.

[0022] By adopting the above technical solution and using PESU resin with suitable molecular weight, PESU can be well adhered to the surface of glass powder to form a wrapped PESU film, which plays a role in improving the compatibility between glass powder and PSU resin.

[0023] Optionally, the thickness ratio of the PSU layer to the modified PSU layer is 8:1.

[0024] By adopting the above technical solution, the PSU layer is composed of pure PSU resin. By matching the thickness of the above layer structure, the UV resistance of the PSU film is improved while maintaining good mechanical properties.

[0025] Optionally, the antioxidant is selected from one or both of antioxidant 1024 and antioxidant DLTP.

[0026] In a second aspect, the present application provides a method for preparing a three-layer co-extruded PSU film using the following technical solution:

[0027] A method for preparing a three-layer co-extruded PSU film comprises the following steps:

[0028] PSU resin is dried and ready for use;

[0029] PSU resin, modified glass powder and antioxidant are mixed, heated, extruded and granulated to obtain modified PSU particles, and the modified PSU particles are then heated to obtain a modified PSU melt;

[0030] heating the PSU resin to obtain a PSU melt;

[0031] The modified PSU melt is distributed to the upper flow channel and the lower flow channel of the die distributor, and the PSU melt is distributed to the middle flow channel of the die distributor. Then, the modified PSU melt and the PSU melt are compound co-extruded in the co-extrusion die, cast into a film after co-extrusion, and cooled and shaped to obtain a three-layer co-extruded PSU film.

[0032] By adopting the above technical solution, the PSU film is prepared by a three-layer co-extrusion method, and the inherent advantages of the composite PSU resin and the UV resistance of the modified PSU are combined to obtain a PSU film with better overall performance.

[0033] In summary, this application has the following beneficial effects:

[0034] 1. This application provides a modified PSU layer containing modified glass powder. Glass powder has excellent ultraviolet absorption and scattering capabilities. Adding glass powder to the modified PSU layer can improve the UV resistance of the PSU film. Furthermore, glass powder is added only to the surface of the PSU film, while the middle PSU layer effectively maintains the mechanical properties of the PSU film, resulting in superior overall performance. The modified glass powder increases the interfacial bonding strength between the modified glass powder and the PSU resin, reduces glass powder agglomeration, improves the dispersion uniformity of the glass powder, and further enhances the UV resistance and mechanical properties of the PSU film. Furthermore, the dispersed modified glass powder has little effect on the light transmittance of the PSU film.

[0035] 2. The structure of PESU resin is similar to that of PSU resin, which improves the compatibility between the surface of the modified glass powder and the PSU resin matrix, thereby improving the interfacial bonding between the two. In addition, PESU resin has good flexibility, which promotes the intercalation of the modified glass powder surface and PSU resin, maintaining the good mechanical properties of the PSU film. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a layer structure diagram of the three-layer co-extruded PSU film of Example 1 of the present application.

[0037] 1. PSU layer; 2. Modified PSU layer. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1 This application is described in further detail.

[0039] Preparation Example 1

[0040] The preparation method of modified glass powder comprises the following steps:

[0041] Weigh 500 g of glass powder, 50 g of PESU resin, 1500 g of ether, 3000 g of water, and 1000 g of dimethylacetamide; the particle size of the glass powder is 1 to 5 μm, and the molecular weight of the PESU resin is 45,000.

[0042] Dissolve PESU resin in dimethylacetamide, then add glass powder to dimethylacetamide, stir and disperse, first add ether dropwise, stir evenly, after the ether is added dropwise, add water dropwise, stir evenly, after the water is added dropwise, continue stirring for 30 minutes, terminate the reaction, filter, separate and collect the solid part, wash the solid part with ethanol and water, and dry to obtain modified glass powder.

[0043] Preparation Example 2

[0044] The preparation method of modified glass powder comprises the following steps:

[0045] Weigh 500 g of glass powder, 125 g of PESU resin, 2500 g of ether, 5000 g of water, and 2000 g of dimethylacetamide; the particle size of the glass powder is 1 to 5 μm, and the molecular weight of the PESU resin is 51,000.

[0046] Dissolve PESU resin in dimethylacetamide, then add glass powder to dimethylacetamide, stir and disperse, first add ether dropwise, stir evenly, after the ether is added dropwise, add water dropwise, stir evenly, after the water is added dropwise, continue stirring for 30 minutes, terminate the reaction, filter, separate and collect the solid part, wash the solid part with ethanol and water, and dry to obtain modified glass powder.

[0047] Preparation Example 3

[0048] This Preparation Example differs from Preparation Example 1 in that the molecular weight of the PESU resin is 92,000.

[0049] Comparative Preparation Example 1

[0050] The difference between this comparative preparation example and preparation example 1 is that the PESU resin is replaced by an equal amount of PSU resin, and the molecular weight of the PSU resin is 65,000.

[0051] Comparative Preparation Example 2

[0052] The difference between this comparative preparation example and preparation example 1 is that the PESU resin is replaced by an equal amount of PPSU resin, and the molecular weight of the PPSU resin is 60,000.

[0053] Example 1

[0054] like Figure 1 As shown, the three-layer co-extruded PSU film includes a PSU layer 1 and two modified PSU layers 2 , and the PSU layer 1 is arranged between the two modified PSU layers 2 .

[0055] The preparation method of the three-layer co-extruded PSU film comprises the following steps:

[0056] Preparation of modified PSU melt:

[0057] Weigh 10 kg of PSU resin, 300 g of modified glass powder, and 70 g of antioxidant.

[0058] The molecular weight of the PSU resin is 78,000, the modified glass powder is prepared according to Preparation Example 1, and the antioxidant is composed of antioxidant 1024 and antioxidant DLTP in a mass ratio of 2:3.

[0059] The PSU resin was dried at 140°C for 4 h and set aside.

[0060] PSU resin, modified glass powder and antioxidant are mixed in a high-speed mixer, and then put into a twin-screw extruder for heating, extrusion and granulation. The extruder temperature is: zone 1 temperature 330°C, zone 2-5 temperature 340°C, and die head temperature 340°C to obtain modified PSU particles. The modified PSU particles are then put into a single-screw extruder and heated to 340°C to obtain a modified PSU melt.

[0061] Preparation of PSU melt:

[0062] Another PSU resin was taken and put into another single-screw extruder and heated to 340° C. to obtain a PSU melt.

[0063] Preparation of three-layer co-extruded PSU film:

[0064] The modified PSU melt is distributed to the upper flow channel and the lower flow channel of the die distributor, and the PSU melt is distributed to the middle flow channel of the die distributor. Then, the modified PSU melt and the PSU melt are compound co-extruded in the co-extrusion die. The die temperature is 340°C. After co-extrusion, the film is cast and cooled to shape. The modified PSU melt forms a modified PSU layer, and the PSU melt forms a PSU layer to obtain a three-layer co-extruded PSU film.

[0065] The thickness of the three-layer co-extruded PSU film is 150 μm, and the thickness ratio of the PSU layer to the single-layer modified PSU layer is 8:1.

[0066] Example 2

[0067] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the modified PSU layer are different.

[0068] The raw materials for preparing the modified PSU layer are:

[0069] 10kg PSU resin, 450g modified glass powder, 120g antioxidant.

[0070] The molecular weight of the PSU resin is 84,000, the modified glass powder is prepared according to Preparation Example 2, and the antioxidant is composed of antioxidant 1024 and antioxidant DLTP in a mass ratio of 2:3.

[0071] Example 3

[0072] The difference between this embodiment and embodiment 1 is that the raw materials for preparing the modified PSU layer are different.

[0073] Among the raw materials for preparing the modified PSU layer, the modified glass powder is prepared according to Preparation Example 3.

[0074] Comparative Example 1

[0075] The PSU film is prepared from PSU resin, comprising the following steps:

[0076] Take PSU resin, the molecular weight of PSU resin is 78000, put the PSU resin into a single screw extruder and heat it to 340°C to obtain a PSU melt, the melt is cast into a film, and cooled and shaped to obtain a PSU film, the thickness of the PSU film is 150 μm.

[0077] Comparative Example 2

[0078] The difference between this comparative example and Example 1 is that the raw materials for preparing the modified PSU layer are different.

[0079] In this comparative example, the modified glass powder was replaced with an equal amount of glass powder.

[0080] Comparative Example 3

[0081] The difference between this comparative example and Example 1 is that the raw materials for preparing the modified PSU layer are different.

[0082] The modified glass powder of this comparative example was prepared by Comparative Preparation Example 1.

[0083] Comparative Example 4

[0084] The difference between this comparative example and Example 1 is that the raw materials for preparing the modified PSU layer are different.

[0085] The modified glass powder of this comparative example was prepared by Comparative Preparation Example 2.

[0086] Performance testing

[0087] Tensile property test: With reference to GB / T 1040.3-2006 “Determination of tensile properties of plastics Part 3: Test conditions for films and sheets”, the tensile strength and elongation at break of the PSU films prepared in each embodiment and comparative example were tested. The test results are shown in Table 1.

[0088] Ultraviolet aging test: The PSU films prepared in each embodiment and comparative example were placed in a UV aging box. The irradiation light source used was a UVA-340 ultraviolet fluorescent lamp. The aging temperature was 55°C, the humidity was 80%, and the aging time was 120 h. After the aging, the tensile properties of the PSU film were tested. The tensile properties of the PSU film that had not been aged were compared and the aging retention rate was calculated. The results are shown in Table 1.

[0089] Light transmittance test: Referring to GB / T 2410-2008 “Determination of light transmittance and haze of transparent plastics”, the light transmittance of the PSU films prepared in each embodiment and comparative example was tested. The test results are shown in Table 1.

[0090] Table 1

[0091]

[0092] From the test results in Table 1, taking Examples 1-2 and Comparative Example 1 as examples, although the addition of modified glass powder will reduce the mechanical tensile properties of the PSU membrane, the reduction is small, and the mechanical properties of the PSU membrane are effectively maintained. After ultraviolet aging, the mechanical tensile properties of the PSU membrane of Examples 1-2 have a high retention rate, and the transmittance remains above 80%. Therefore, it is suitable for application scenarios with strong ultraviolet radiation and has higher durability.

[0093] Taking Example 1 and Comparative Example 2 as examples, it can be seen that the addition of unmodified glass powder leads to a more serious reduction in the tensile properties of the PSU film due to the poor dispersibility of the glass powder, and the degree of performance degradation after ultraviolet aging is even higher.

[0094] Taking Example 1 and Comparative Examples 3-4 as examples, it can be seen that when using glass powder modified with PSU or PPSU, the mechanical properties of the PSU film obtained cannot be well maintained after ultraviolet aging. Therefore, it is shown that the glass powder modified with PESU can effectively enhance the ultraviolet aging resistance of the PSU film.

[0095] Taking Example 1 and Example 3 as examples, it can be seen that selecting a PESU resin with a moderate molecular weight to modify the glass powder can further improve the UV aging resistance of the PSU film.

[0096] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A three-layer co-extruded PSU film, characterized by: The invention comprises a PSU layer and two modified PSU layers, wherein the PSU layer is arranged between the two modified PSU layers, and the modified PSU layer is prepared from raw materials comprising the following parts by weight: 100 parts of PSU resin; 3~4.5 parts of modified glass powder; 0.7~1.2 parts of antioxidant; The modified glass powder is obtained by attaching PESU resin to the surface of the glass powder.

2. A three-layer co-extruded PSU film according to claim 1, characterized in that: The raw materials for preparing the modified glass powder include glass powder, PESU resin, ether, water and dimethylacetamide, and the mass ratio of the glass powder, PESU resin, ether, water and dimethylacetamide is 1:(0.1-0.25):(3-5):(6-10):(2-4).

3. A three-layer co-extruded PSU film according to claim 2, characterized in that: The preparation method of the modified glass powder comprises the following steps: dissolving PESU resin in dimethylacetamide, adding glass powder into the dimethylacetamide, first adding ether dropwise, stirring evenly, then adding water dropwise, stirring evenly, and separating to obtain the modified glass powder.

4. The three-layer co-extruded PSU film according to claim 2, characterized in that: The particle size of the glass powder is 1-5 μm.

5. The three-layer co-extruded PSU film according to claim 1, characterized in that: The molecular weight of the PSU resin is 78,000-84,000.

6. The three-layer co-extruded PSU film according to claim 1, characterized in that: The molecular weight of the PESU resin is 45,000-51,000.

7. The three-layer co-extruded PSU film according to claim 1, characterized in that: The antioxidant is selected from one or both of antioxidant 1024 and antioxidant DLTP.

8. A method for preparing a three-layer co-extruded PSU film according to any one of claims 1 to 7, characterized in that: The following steps are involved: PSU resin is dried and ready for use; PSU resin, modified glass powder and antioxidant are mixed, heated, extruded and granulated to obtain modified PSU particles, and the modified PSU particles are then heated to obtain a modified PSU melt; heating the PSU resin to obtain a PSU melt; The modified PSU melt is distributed to the upper flow channel and the lower flow channel of the die distributor, and the PSU melt is distributed to the middle flow channel of the die distributor. Then, the modified PSU melt and the PSU melt are compound co-extruded in the co-extrusion die, cast into a film after co-extrusion, and cooled and shaped to obtain a three-layer co-extruded PSU film.

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