CN117124676A

CN117124676A - Polyphenylene sulfide composite membrane and preparation method thereof

Info

Publication number: CN117124676A
Application number: CN202210983306.8A
Authority: CN
Inventors: 廖洪传
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2023-11-28

Abstract

The invention discloses a polyphenylene sulfide composite film, which comprises a PPS layer and a heat-resistant plastic layer arranged on one surface of the PPS layer, wherein the heat-resistant plastic layer is a plastic layer (including a modified plastic layer) with a thermal deformation temperature of more than 110 ℃, and a base material of the heat-resistant plastic layer contains one or more of PC, PA, PBT, PPO, POM or other resins with thermal deformation temperature of not less than 110 ℃. The thickness of the PPS layer accounts for 2-40% of the total thickness of the two layers, and the thickness of the heat-resistant plastic layer accounts for 60-98% of the total thickness of the two layers. The PPS composite film of the invention can not deform under the environment of up to 150-200 degrees, and the PPS film in the PPS composite film can be fully crystallized, thereby further improving the overall heat resistance and rigidity of the composite film.

Description

Polyphenylene sulfide composite membrane and preparation method thereof

Technical Field

The invention relates to a polyphenylene sulfide (PPS) composite film which can be successfully applied to the fields of electronics, electric appliances, automobiles, aerospace and the like.

Background

Polyphenylene Sulfide (PPS) has excellent overall properties, with the following outstanding advantages:

-good rigidity; the hardness is high, and the wear resistance is high;

high thermal stability: the thermal deformation temperature of the crystal is above 260 ℃ after crystallization, the crystal is degraded in air at 700 ℃, can be continuously used at 200-240 ℃, is more stable in air or nitrogen at the temperature lower than 400 ℃ and basically has no mass loss;

good resistance to chemical attack by chemicals such as acids, bases, hydrocarbons, ketones, alcohols, esters, chlorohydrocarbons, etc., insoluble in any organic solvent known at below 175 ℃ and soluble in chloronaphthalenes only above 175 ℃;

the electrical property is quite stable, the dielectric constant is very small, the dielectric loss is quite low, the surface resistance and the volume resistance are insensitive to the change of frequency, temperature and humidity, the arc-resistant time is long, and the material is a good electrical insulation material;

the dimensional stability is good, the molding shrinkage is 0.15-0.30%, and the minimum shrinkage can reach 0.01%;

-low water absorption: only about 0.03%;

good flame retardancy: the oxygen index can reach 44%, and the flame retardant property of UL 94V-0 can be achieved without adding flame retardant;

-radiation resistance.

Meanwhile, the defects of polyphenylene sulfide (PPS) are obvious, because the PPS has low relative molecular weight, the number average relative molecular weight is 5500, and the rigidity of a high molecular chain is increased by adding a large number of benzene rings on a PPS main chain, so that the brittleness and impact toughness of the PPS are not high, and the application of the PPS is limited to a certain extent, especially the application on a film. The PPS film prepared by the ordinary casting process has poor impact resistance, low crystallinity and temperature difference resistance, and is not produced on a large scale in the current industry.

The PPS film circulated in the market at present is basically a biaxially oriented PPS film or a PPS/PET composite biaxially oriented film, and the crystallinity of the PPS film is improved through a biaxially oriented process, so that the temperature resistance and the impact resistance of the PPS film are improved. However, the biaxial stretching process has huge equipment investment, complex process, high cost and extremely narrow processing window, is currently mastered by a few international companies such as eastern japan, and has strict patent and confidentiality technical protection.

Therefore, there is a need to develop a PPS film that is less costly, overcomes the disadvantages of PPS such as poor impact resistance, and is suitable for common processing techniques.

Disclosure of Invention

The invention provides a polyphenylene sulfide composite membrane and a preparation method thereof, which have the characteristics of lower cost, capability of overcoming the defect of poor impact resistance of PPS and suitability for common processing technology.

The technical scheme of the invention is as follows:

a polyphenylene sulfide (PPS) composite film comprises a polyphenylene sulfide (PPS) layer and a heat-resistant plastic layer, wherein the heat-resistant plastic layer is arranged on one surface of the polyphenylene sulfide layer, the thickness of the polyphenylene sulfide layer accounts for 2-40% of the total thickness of the two layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, and the thickness of the heat-resistant plastic layer accounts for 60-98% of the total thickness of the two layers of the polyphenylene sulfide layer and the heat-resistant plastic layer.

Because the fastest crystallization temperature of PPS is about 127 ℃, the common salivation PPS film has low crystallinity, temperature difference resistance and low mechanical strength due to the fact that the molten material is quickly cooled to normal temperature, the thermal deformation temperature is about 90 ℃, the PPS film is softened and then crystallized relatively quickly when the temperature is gradually increased to 90-230 ℃ in subsequent processing or application, and internal stress is released and new internal stress is generated to cause distortion deformation, even if the high-temperature crystallization process is added to crystallize the PPS film, or the PPS film is fully crystallized in subsequent high-temperature application, the material is also brittle. Therefore, the common salivated PPS film cannot be mass produced and applied.

In order to solve the problem, the PPS composite film provided by the invention is compounded with the heat-resistant plastic layer, and the heat-resistant plastic layer is not softened when the temperature is increased due to high heat resistance of the heat-resistant plastic layer, and the PPS layer is softened and crystallized, but the PPS composite film is not enough to deform as a whole, and after the crystallinity of the PPS layer of the composite film reaches a stable value, the heat resistance and rigidity of the whole composite film are further improved. Therefore, the problems of low crystallinity, temperature difference resistance, low mechanical strength and the like of the common salivation PPS film can be solved. And the thickness ratio of the PPS layer to the heat-resistant plastic layer is properly selected, and the heat-resistant plastic layer with good impact resistance is further preferably selected, so that the composite film with high impact resistance and meeting the use requirement can be obtained.

Because the cost of the heat-resistant plastic is far lower than that of PPS, and is only one third of the latter or even lower, and the cost of the casting coextrusion process adopted by the invention is also lower than that of the biaxial stretching process, the cost of the PPS composite film is greatly reduced compared with that of the traditional biaxial stretching PPS film or PPS/PET composite biaxial stretching film.

In one embodiment, the polyphenylene sulfide composite film comprises a three-layer structure of a polyphenylene sulfide layer/a heat-resistant plastic layer/a polyphenylene sulfide layer, wherein the heat-resistant plastic layer is positioned between two polyphenylene sulfide (PPS) layers; the thickness of each polyphenylene sulfide layer accounts for 2-40% of the total thickness of the three layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, and the thickness of the heat-resistant plastic layer accounts for 20-96% of the total thickness of the three layers of the polyphenylene sulfide layer and the heat-resistant plastic layer. The three-layer structure has better performances such as temperature resistance, flame retardance and the like, and when the three-layer structure is applied, PPS is arranged on the surface layer, so that the overall performance is improved.

The material of the PPS layer is preferably PPS and contains no other components. Alternatively, the PPS layer is a PPS-based material, and may contain a small amount of substances other than PPS, for example, other resins (such as PA and/or epoxy resin) and/or additives, that is, a PPS-based composite material, or a modified material, and the total content of the other substances may be 0% to 50% by weight, preferably 0% to 20%. The additives include, but are not limited to, inorganic fibers (such as glass fibers, etc.), inorganic powders (such as calcium carbonate, talcum powder, nano silicon dioxide, etc.), antioxidants and functional additives (such as wear-resistant agents (such as PTFE), compatibilizers (such as epoxy resins), conductive graphite, cross-linking agents, coupling agents, toughening agents, etc.). The material of the PPS layer may contain 50 to 100wt% PPS.

The heat-resistant plastic layer is a plastic with a heat distortion temperature of more than 110 degrees (tested according to ISO75-1, -2/Method B standard), more preferably a plastic with a heat distortion temperature of more than 130 degrees (tested according to ISO75-1, -2/Method B standard), and the material of the heat-resistant plastic layer can be modified plastic or unmodified plastic. For example, the substrate of the heat resistant plastic layer may contain one or more of PC, PA, PBT, PPO, POM, and other plastics having heat distortion temperatures not less than 110 degrees. For example, the heat resistant plastic layer may comprise only PC, or only PA, or only PBT, or only PPO, or a blend of PC and PBT, or the like. Alternatively, the heat resistant plastic layer may be a modified plastic such as a physical modified plastic, and the performance of the modified plastic may be improved by adding fillers, and the fillers or additives may include, but are not limited to, inorganic fibers (e.g., glass fibers, etc.), inorganic powders (e.g., calcium carbonate, talc, etc.), antioxidants, and organic functional additives (e.g., anti-wear agents (e.g., PTFE), compatibilizers (e.g., epoxy resins), cross-linking agents, coupling agents, toughening agents, flame retardants (e.g., sulfonate salts), etc.).

Further, the heat-resistant plastic layer is preferably made of a material with good impact resistance, and the impact resistance can be measured by cantilever notched impact strength (ISO 180/1A). Cantilever notched impact strength of PPS in general<10KJ/m ² . Preferably, the notched Izod impact strength of the heat-resistant plastic layer is more than or equal to 20KJ/m ² More preferably 50KJ/m or more ² 。

In order to increase the bonding strength of the PPS layer and the heat-resistant plastic layer, a certain content of PPS can be added in the heat-resistant plastic layer; some PPS leftover materials can also be recycled and added into a heat-resistant plastic layer, for example, in actual production, edges are required to be cut off to obtain a product with neat edges when sheet films are produced, the cut edges are usually required to be reused after being crushed and are returned to an extruder for processing, and the PPS leftover materials are generally added into an intermediate layer (the intermediate layer is thicker, the receiving capacity is good, and the performance of the surface layer with better performance is not affected), so that the intermediate layer (namely the heat-resistant plastic layer) contains a small amount of PPS. Accordingly, the heat-resistant plastic layer may contain a part of PPS in the range of 0 to 20%, preferably the PPS content should be less than 15wt% of the heat-resistant plastic layer, more preferably 0 to 10%. The heat-resistant plastic layer may not contain PPS.

In the present invention, a two-layer structure of a polyphenylene sulfide layer/a heat-resistant plastic layer or a three-layer structure of a polyphenylene sulfide layer/a heat-resistant plastic layer/a polyphenylene sulfide layer may be used as a basic unit, and the laminated and repeated arrangement may be performed so that the polyphenylene sulfide composite film of the present invention includes a plurality of the above basic units.

In the present invention, no other layer structure is provided between the polyphenylene sulfide layer and the heat-resistant plastic layer of the polyphenylene sulfide composite film, but other layer structures, such as functional layers, may be provided in addition to the two-layer structure of the polyphenylene sulfide layer/the heat-resistant plastic layer or the three-layer structure of the polyphenylene sulfide layer/the heat-resistant plastic layer/the polyphenylene sulfide layer, and the present invention is not limited to the arrangement or the arrangement type of other layer structures, such as functional layers.

The total thickness of the polyphenylene sulfide composite film is preferably 0.02 to 6mm, more preferably 0.075 to 1.5mm, and even more preferably 0.12 to 0.95mm.

In a preferred embodiment of the invention, the PPS layer and the heat-resistant plastic layer are directly joined together by a coextrusion process.

Preferably, the PPS composite film can be subjected to crystallization and annealing treatment at 90-230 ℃. The crystallization and annealing treatment requires heating, and the treatment is performed at high temperature, mainly achieving two effects:

first, PPS can rapidly crystallize, and after crystallization, its temperature resistance is greatly improved, thereby also improving the heat resistance of the composite film. Before PPS is crystallized, the temperature resistance is poor and deformation is generated at less than 100 ℃. The heat resistance of the composite film before crystallization mainly depends on a heat-resistant plastic layer (such as PC, thermal deformation temperature is about 140 ℃). After crystallization, the melting point of PPS is about 260-285 ℃, and the heat resistance of the composite film is improved to a better heat resistance level than that of the heat-resistant plastic layer. Taking PPS/PC/PPS as an example, even if the composite film is heated to 230 degrees after crystallization, the composite film is only softened, but the shape of the composite film is maintained because PPS whose surface layer has been crystallized is not heated to the melting point, is not softened, and has relatively good rigidity, whereas PC films having less than 200 degrees are surface softened, and the surfaces are tacky, are not rigid, and cannot maintain the shape of the film.

And secondly, annealing can reduce the internal stress of the composite film and reduce the distortion and deformation of the composite film under high-temperature application.

In particular, the crystallization and annealing treatment may be a special production process or a high-temperature application environment. The high-temperature application environment means that the composite film is not specially subjected to high-temperature crystallization and annealing, and is directly sold to a customer, if the application temperature of the customer is high, the PPS is quickly crystallized in a heating process in use and can be crystallized in tens of seconds to a few seconds, the PPS is quickly crystallized in the heating process of the application environment, and the heat resistance of the composite film is correspondingly improved. Of course, PPS does not crystallize if the application temperature of the customer is low, which corresponds to not passing through a high temperature application environment, but the heat resistance of the composite film is also sufficient.

The invention also provides a preparation method of the PPS composite film, which comprises the steps of extruding and plasticizing PPS from one extruder, enabling a molten material to flow to a distributor, extruding and plasticizing heat-resistant plastic from the other extruder, enabling the molten material to flow to the distributor, dividing the PPS into one or two layers of molten material flows at the distributor, overlapping one or two sides of the distributor and the heat-resistant plastic layers to form a two-layer or three-layer structure, and cooling and forming the solid film after flowing out of a die head.

The above preparation method is further preferable, and then the solid film is subjected to heat treatment at 90 to 230 ℃ to crystallize and anneal the solid film, and the heat treatment temperature is further preferable to be 120 to 160 ℃.

The invention also provides a preparation method of the PPS composite film, which comprises the steps of extruding and plasticizing PPS from a first extruder, enabling a molten material to flow to a distributor, extruding and plasticizing heat-resistant plastic from a second extruder, enabling the molten material to flow to the distributor, extruding and plasticizing PPS from a third extruder, enabling the molten material to flow to the distributor, extruding and plasticizing PPS molten materials from the first extruder and the third extruder to be overlapped on two sides of the distributor and the heat-resistant plastic layer to form a three-layer structure, and cooling and forming the solid film after the molten material flows out of a die head.

The above preparation method is further preferable, and then the solid film is subjected to heat treatment in an environment of 90 to 230 ℃ to crystallize and anneal the solid film. The heat treatment is preferably carried out at a temperature of 120℃to 160 ℃.

In both of the above methods, the molten materials may also be laminated at the die to form a multilayer structure.

The PPS composite film disclosed by the invention adopts the combination of PPS and a heat-resistant plastic layer structure as a main structural layer, and simultaneously realizes the effects of low cost, chemical resistance, impact resistance, high rigidity, high flame retardance and high temperature resistance.

Compared with the prior art, the invention has the following beneficial effects:

1. at present, PPS film or PPS/PET composite film is produced by international company by biaxial stretching process, which has large investment and high process cost, and has patent and security protection technology, and can not be widely popularized and applied. The invention can produce PPS composite film by using common casting equipment and process, and greatly reduces equipment investment cost and process technology cost.

2. The common salivation PPS film cannot resist high temperature due to low crystallinity, and is softened and deformed when heated to 90 ℃, so that the crystallization phenomenon further aggravates the deformation in a high temperature region. The PPS composite film of the invention can not deform under the environment of up to 150-200 degrees, can not deform under the environment of 240 degrees at most, and can fully crystallize the PPS film, thereby further improving the overall heat resistance and rigidity of the composite film.

3. The common salivation PPS film has low impact strength and is easy to crack after being fully thermally crystallized. The heat-resistant plastic layer in the PPS composite film is preferably a material with good impact resistance, can play a synergistic reinforcing effect in the structure, improves the integral impact resistance of the PPS composite film, and overcomes the defect of brittleness of the PPS film.

4. PPS is 3 to 5 times more costly than common engineering plastics (e.g., PC), resulting in high PPS film costs. The PPS composite film contains a heat-resistant plastic layer which is made of common engineering plastics, so that the raw material cost of the PPS composite film is also greatly reduced.

Of course, it is not necessary for any one product to practice the invention to achieve all of the advantages set forth above at the same time.

Drawings

Fig. 1 is a schematic structural diagram of a PPS composite film according to an embodiment of the present invention;

FIG. 2 is a schematic view of another structure of a PPS composite film according to an embodiment of the present invention;

in the figure, a 1-PPS layer; 2-a heat resistant plastic layer; 3-PPS layer.

Detailed Description

The invention provides a polyphenylene sulfide composite film, which has two main preferable implementation structures.

One of the two-layer structure comprises a polyphenylene sulfide (PPS) layer and a heat-resistant plastic layer, wherein the heat-resistant plastic layer is arranged on one surface of the polyphenylene sulfide layer, the thickness of the polyphenylene sulfide layer accounts for 2-40% of the total thickness of the two layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, the thickness of the heat-resistant plastic layer accounts for 60-98% of the total thickness of the two layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, and a schematic diagram of the two-layer structure is shown in figure 1 of an attached drawing of the specification.

The other is of a three-layer structure and comprises two polyphenylene sulfide layers and one heat-resistant plastic layer, wherein the heat-resistant plastic layer is arranged on one surface of the polyphenylene sulfide layers, and the heat-resistant plastic layer is positioned on the other surface of the heat-resistant plastic layer, so that the heat-resistant plastic layer is positioned between the two polyphenylene sulfide layers; the thickness of each polyphenylene sulfide layer accounts for 2-40% of the total thickness of the three layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, the thickness of the heat-resistant plastic layer accounts for 20-96% of the total thickness of the three layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, and a schematic diagram of the three-layer structure is shown in figure 2 of the attached drawing.

On the basis that the two-layer and three-layer structures are basic invention points, the polyphenylene sulfide composite film also has various modification embodiments, and the description is omitted here for the sake of illustration in the summary of the invention.

In this document, a range from "one value to another value" is a shorthand way of referring individually to all the values in the range, which are avoided in the specification. Thus, recitation of a particular numerical range includes any numerical value within that range, as well as the smaller numerical range bounded by any numerical value within that range, as if the any numerical value and the smaller numerical range were written in the specification in the clear.

The invention will be further illustrated with reference to specific examples. It should be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. Modifications and adaptations of the invention will occur to those skilled in the art and are intended to be within the scope of the invention in practice.

Example 1

A PPS composite film of this embodiment 1 is shown in FIG. 2, and includes a PPS layer 1 located on the upper layer of the film, a PC layer 2 located on the lower surface of the PPS layer 1, and a PPS layer 3 further located on the lower surface of the PC layer 2, wherein the thickness of the PPS layer 1 is 10% of the total thickness, the thickness of the PC layer 2 is 80% of the total thickness, the thickness of the PPS layer 3 is 10% of the total thickness, and the total thickness of the film is 0.2mm.

The preparation method comprises the following steps: the PPS granules and the PC granules are respectively dried, conveyed to a co-extrusion sheet machine set for extrusion molding and heat treated for 3 minutes at 135 ℃.

The test results of the chemical corrosion resistance and the flame retardant property are shown in the table one, and the PC film material with the same thickness is used as a control, and the performance is shown in the table two.

List one

Watch II

The comparison of the table results shows that after the PPS layer is compounded on the surface of the PC layer with lower cost, the whole composite film also has the advantages of chemical resistance and high flame retardance of the PPS film.

Example 2

A PPS composite film in this embodiment 2 is shown in FIG. 1, and comprises a PPS layer 1 located on the upper layer of the film, and a PC and PBT blend alloy layer 2 located on the lower surface of the PPS layer 1, wherein the thickness of the PPS layer 1 is 4% of the total thickness, the thickness of the PC and PBT blend alloy layer 2 is 96% of the total thickness, and the total thickness of the film is 0.5mm.

The preparation method comprises the following steps: the PPS granules, the PC and the PBT blend alloy granules are respectively subjected to drying treatment, conveyed to a coextrusion sheet machine set for extrusion molding, and subjected to heat treatment at 150 ℃ for 5 minutes.

The surface hardness performance test results are shown in Table three, and the performance of the PPS film material with the same thickness is shown in Table four as a comparison. The material cost calculations are also listed in tables three and four.

Watch III

Table four

The comparison of the results of the above tables shows that the PPS composite film has a surface hardness similar to that of PPS film, but at a cost reduced by 48% compared to the latter.

Example 3

The PPS composite film of this embodiment 3 includes a PPS/PA6 blend alloy layer 1 (PPS accounts for 80% and PA6 accounts for 20% in the substrate) located on the upper layer of the film, a PA6 layer 2 located on the lower surface of the PPS/PA6 blend alloy layer 1, and a PPS/PA6 blend alloy layer 3 (PPS accounts for 80% and PA6 accounts for 20% in the substrate) located on the lower surface of the PA6 layer 2, the thickness of the PPS/PA6 blend alloy layer 1 accounts for 30% of the total thickness, the thickness of the PA6 layer 2 accounts for 40% of the total thickness, the thickness of the PPS/PA6 blend alloy layer 3 accounts for 30% of the total thickness, and the total thickness of the film is 1.0mm.

The preparation method comprises the following steps: and respectively drying PPS/PA6 blending alloy granules and PA6 granules, conveying to a co-extrusion sheet machine set for extrusion molding, and carrying out heat treatment at 135 ℃ for 10 minutes.

The notched impact strength performance test results are shown in Table five, and the performance of the same thickness PPS film material is shown in Table six. The material cost calculations are also listed in tables three and four.

TABLE five

TABLE six

The comparison of the results of the table shows that the PPS composite film improves the notch impact strength of the PPS film and simultaneously reduces the cost by 36 percent.

Example 4

The PPS composite film of this embodiment 4 includes a PPS layer 1 located on the upper layer of the film, a PC layer 2 located on the lower surface of the PPS layer 1, and a PPS layer 3 further located on the lower surface of the PC layer 2, wherein the PPS layer 1 has a thickness of 25% of the total thickness, the PC layer 2 has a thickness of 50% of the total thickness, the PPS layer 3 has a thickness of 25% of the total thickness, and the total thickness of the film is 0.5mm.

The preparation method comprises the following steps: the PPS granules and the PC granules are respectively dried, conveyed to a co-extrusion sheet machine set for extrusion molding and heat treated for 5 minutes at 135 ℃.

In addition, the PPS composite film and the PC film of example 1 were each produced into a sheet having a thickness of 1.0mm using the same raw materials and processes. And heat treated at 135℃for 5 minutes.

The PPS composite film comprises a PPS layer 1 positioned on the upper layer of the film, a modified PA6 layer 2 with a thermal deformation temperature of 160 ℃ (ISO 75-1, -2,0.45 MPa) and a PPS layer 3 arranged on the lower surface of the modified PA6 layer 2, wherein the thickness of the PPS layer 1 accounts for 25% of the total thickness, the thickness of the modified PA6 layer 2 accounts for 50% of the total thickness, the thickness of the PPS layer 3 accounts for 25% of the total thickness, and the total thickness of the film is 1.0mm.

The preparation method comprises the following steps: and respectively drying PPS granules and modified PA6 granules, conveying to a co-extrusion sheet machine set for extrusion molding, and carrying out heat treatment at 150 ℃ for 5 minutes.

The heat distortion temperature of the above samples was measured, and the measurement results are shown in Table seven.

Watch seven

The comparison of the results shows that after the PPS composite film is subjected to crystallization annealing at the temperature not higher than the thermal deformation temperature of the middle layer, the thermal deformation temperature of the PPS layer is greatly increased due to PPS crystallization, so that the thermal deformation temperature of the whole composite film is obviously improved, and the composite film can not deform under the environment of 150-200 ℃.

It is readily apparent to those skilled in the art from the teachings of the present invention and the foregoing examples that each of the raw materials and their equivalents, each of the processing methods and their equivalents as exemplified or exemplified herein may be used to practice the present invention, and that the values of the upper and lower limits and the values of the intervals of the parameters of each of the raw materials and the processing methods may be used to practice the present invention, and the examples are not to be construed as limiting.

The preferred embodiments of the invention disclosed above are intended only to assist in the explanation of the invention. The preferred embodiments are not exhaustive or to limit the invention to the precise form disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best understand and utilize the invention. The invention is limited only by the claims and the full scope and equivalents thereof.

Claims

1. The polyphenylene sulfide composite membrane is characterized by comprising a polyphenylene sulfide layer and a heat-resistant plastic layer, wherein the heat-resistant plastic layer is arranged on one surface of the polyphenylene sulfide layer, the thickness of the polyphenylene sulfide layer accounts for 2-40% of the total thickness of the two layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, and the thickness of the heat-resistant plastic layer accounts for 60-98% of the total thickness of the two layers of the polyphenylene sulfide layer and the heat-resistant plastic layer.

2. The polyphenylene sulfide composite film according to claim 1, further comprising another polyphenylene sulfide layer on the other surface of the heat-resistant plastic layer with the heat-resistant plastic layer being located between two polyphenylene sulfide layers; the thickness of each polyphenylene sulfide layer accounts for 2-40% of the total thickness of the three layers of the polyphenylene sulfide layer and the heat-resistant plastic layer, and the thickness of the heat-resistant plastic layer accounts for 20-96% of the total thickness of the three layers of the polyphenylene sulfide layer and the heat-resistant plastic layer.

3. The polyphenylene sulfide composite film according to claim 1 or 2, comprising one or more sets of polyphenylene sulfide layer/heat resistant plastic layer, or polyphenylene sulfide layer/heat resistant plastic layer/polyphenylene sulfide layer base unit.

4. The polyphenylene sulfide composite film according to claim 1 or 2, wherein the material of the polyphenylene sulfide layer does not contain other resins and additives.

5. The polyphenylene sulfide composite film according to claim 1 or 2, wherein the polyphenylene sulfide layer is made of a polyphenylene sulfide-based material, contains other resins and/or additives, and has a polyphenylene sulfide content of 50 to 100wt%.

6. The polyphenylene sulfide composite film according to claim 1 or 2, wherein the heat resistant plastic layer is a plastic layer having a heat distortion temperature above 110 degrees, wherein the heat distortion temperature is tested according to ISO75-1, -2/Method B standard.

7. The polyphenylene sulfide composite film according to claim 1 or 2, wherein the heat resistant plastic layer is a plastic layer having a heat distortion temperature of 130 degrees or more, the heat distortion temperature being measured according to ISO75-1, -2/Method B standard.

8. The polyphenylene sulfide composite film according to claim 1 or 2, wherein the substrate of the heat-resistant plastic layer contains one or more of polycarbonate PC, polyamide PA, polybutylene terephthalate PBT, polyethylene terephthalate PET, polyphenylene oxide PPO, polyoxymethylene POM; the material of the heat-resistant plastic layer contains or does not contain other resin and/or filler and additive.

9. The polyphenylene sulfide composite film according to claim 8, wherein the heat resistant plastic layer contains polyphenylene sulfide and the polyphenylene sulfide content is less than 15wt% of the heat resistant plastic layer.

10. The polyphenylene sulfide composite film according to claim 6, wherein the heat-resistant plastic layer has a notched Izod impact strength (ISO 180/1A) of 20KJ/m or more ² 。

11. The polyphenylene sulfide composite film according to claim 10, wherein the heat resistant plastic layer has a notched Izod impact strength (ISO 180/1A) of 50KJ/m or more ² 。

12. The polyphenylene sulfide composite film according to claim 1 or 2, characterized in that the total thickness of the polyphenylene sulfide composite film is 0.02 to 6mm.

13. The polyphenylene sulfide composite film according to claim 1 or 2, characterized in that the total thickness of the polyphenylene sulfide composite film is 0.075 to 1.5mm.

14. The polyphenylene sulfide composite film according to claim 1 or 2, characterized in that the total thickness of the polyphenylene sulfide composite film is 0.12 to 0.95mm.

15. The polyphenylene sulfide composite film according to claim 1 or 2, characterized in that the polyphenylene sulfide layer and the heat resistant plastic layer are directly compounded together by a co-extrusion process.

16. The polyphenylene sulfide composite film according to claim 15, wherein the polyphenylene sulfide composite film produced by the coextrusion process is subjected to crystallization and annealing at 90 to 230 ℃.

17. The polyphenylene sulfide composite film according to claim 3, wherein the polyphenylene sulfide layer/heat resistant plastic layer unit is selected from PPS/PC, PPS/PA, PPS/PBT, or PPS/PPO, and the polyphenylene sulfide layer/heat resistant plastic layer/polyphenylene sulfide layer unit is selected from PPS/PC/PPS, PPS/PA/PPS, PPS/PBT/PPS, or PPS/PPO/PPS.

18. A method for preparing the polyphenylene sulfide composite membrane according to any one of claims 1 to 17, comprising:

the PPS is extruded and plasticized from one extruder, the molten material flows to a distributor, and the heat-resistant plastic is extruded and plasticized from the other extruder, and the molten material also flows to the distributor, wherein the PPS is divided into one layer or two layers of molten material flows at the distributor, and one side or two sides of the distributor and the heat-resistant plastic layer are overlapped together to form a two-layer or three-layer structure, and the two layers or three-layer structure is cooled and formed into a solid film after flowing out of a die head.

19. A method for preparing the polyphenylene sulfide composite membrane as set forth in claims 2 to 17, comprising:

the PPS is extruded and plasticized from a first extruder, the molten material flows to a distributor, the heat-resistant plastic is extruded and plasticized from a second extruder, the molten material also flows to the distributor, the PPS is extruded and plasticized from a third extruder, the molten material flows to the distributor, the plasticized PPS molten materials extruded and plasticized from the first extruder and the third extruder are overlapped on two sides of the distributor and the heat-resistant plastic layer to form a three-layer structure, and the three-layer structure is cooled and molded into a solid film after flowing out of a die head.

20. The method for producing a polyphenylene sulfide composite film according to claim 18 or 19, further comprising: and (3) placing the solid film in an environment of 90-230 ℃ for heat treatment so as to crystallize and anneal the solid film.