Ultrahigh molecular weight polyethylene film and preparation method thereof

Abstract

The invention relates to the technical field of polyethylene films, in particular to an ultra-high molecular weight polyethylene film, a surface-modified ultra-high molecular weight polyethylene film, an ultra-high molecular weight polyethylene film-cured epoxy resin-metal composite material and a preparation method. The epoxidized metallocene poly-alpha-olefin (mPAO) oligomer is added into the raw material of the ultra-high molecular weight polyethylene film, and the crystallization and orientation of the UHMWPE are not damaged by utilizing the characteristic of similar chemical structure, so that the excellent mechanical property of the ultra-high molecular weight polyethylene film is ensured. In addition, the epoxidation of the mPAO oligomer improves the polarity and initial adhesive strength of the ultra-high molecular weight polyethylene film by introducing an epoxy group, and provides reactive sites for subsequent surface modification. Besides, a scheme of soaking the ultra-high molecular weight polyethylene film with organic amine is provided, amino or silicon hydroxyl with higher polarity and reaction activity is introduced, and physical anchoring is converted into stronger chemical covalent bond combination after the ultra-high molecular weight polyethylene film is bonded with epoxy resin, so that the adhesive property is better.

Description

Technical Field

[0001] This application relates to the field of polyethylene film technology, specifically to an ultra-high molecular weight polyethylene film, a surface-modified ultra-high molecular weight polyethylene film, an ultra-high molecular weight polyethylene film-epoxy resin cured product-metal composite material, and a preparation method thereof. Background Technology

[0002] Ultra-high molecular weight polyethylene (UHMWPE) film possesses many excellent properties, such as high tensile strength, low specific gravity, high impact resistance, and excellent chemical resistance. It is widely used as a bulletproof material, aerospace material, biomedical material, and fishing gear material. During gel spinning, the molecular chains are fully extended, resulting in extremely high crystallinity and molecular orientation of UHMWPE, leading to its high modulus and high strength. However, the repeating methylene structures in the UHMWPE molecular chain segments result in surface chemical inertness, making it difficult to react with polar adhesives such as epoxy resins. Furthermore, the highly oriented UHMWPE film is not easily penetrated by epoxy resins and has poor hydrophilicity, which limits its widespread application. Therefore, improving the surface polarity of UHMWPE film and enhancing its adhesive properties has become a key focus in the industry.

[0003] Current technologies propose various modification methods to improve the surface polarity of UHMWPE films and enhance their adhesion properties, such as plasma treatment, ultraviolet light-induced grafting, electron beam irradiation grafting, and X-ray irradiation grafting. However, these methods suffer from problems such as short processing time, insufficient uniformity, low grafting efficiency, potential breakage or degradation of the UHMWPE film, and excessively high equipment and radiation protection costs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to improve the surface polarity of ultra-high molecular weight polyethylene (UHMWPE) films using a relatively mild and long-lasting method, thereby enhancing their adhesive properties while maintaining the excellent mechanical properties of the UHMWPE films. This application improves the raw materials of UHMWPE films by adding linear low-density polyethylene and epoxidized metallocene polyalphaolefin oligomers, thereby introducing polar epoxy groups. Furthermore, organic amines can be impregnated on the surface, allowing the epoxy groups to react with the amines at room temperature or higher, introducing a stable polar layer to enhance adhesive performance.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: In a first aspect, there is an ultra-high molecular weight polyethylene film, the raw material composition of which includes ultra-high molecular weight polyethylene, linear low-density polyethylene and epoxidized metallocene polyalphaolefin oligomer.

[0006] The viscosity-average molecular weight of the ultra-high molecular weight polyethylene is (1×10⁻⁶). 5-1×10 7 )mol / g; Preferably, the viscosity-average molecular weight of the ultra-high molecular weight polyethylene is (1×10⁻⁶). 6 -1×10 7 )mol / g; The linear low-density polyethylene is a resin obtained by polymerizing ethylene with higher α-olefin monomers. The molecular chain contains short-branched low-density polyethylene. The melt flow rate (MFR) of the linear low-density polyethylene tested according to ASTM D1238 is in the range of 0.5-3.0 (g / 10min@190℃ / 2.16 kg load). Preferably, the melt flow rate (MFR) of the linear low-density polyethylene, tested according to ASTM D1238, is in the range of 0.5-1.5 (g / 10min@190℃ / 2.16 kg load). The degree of polymerization of the epoxidized metallocene polyalphaolefin oligomer is 2-4, preferably 2-3. Preferably, the structure of the epoxidized metallocene polyalphaolefin oligomer is selected from: or Among them, a, b and c are independent of each other, and can take the same or different values. The range of values ​​for a, b and c is 3-19. Preferably, the values ​​of a, b, and c are in the range of 7-19; Preferably, the values ​​of a, b and c are the same.

[0007] Furthermore, the epoxidized metallocene polyalphaolefin oligomer is obtained by epoxidation of the metallocene polyalphaolefin oligomer. The epoxidation reaction specifically includes: reacting the metallocene polyalphaolefin oligomer, 88wt% formic acid aqueous solution, 30wt% hydrogen peroxide aqueous solution, 70wt% sulfuric acid aqueous solution, and solvent ethyl n-propyl ether at a mass ratio of 1:0.15:0.75:0.05:0.75 at a temperature of 60-120℃ for 1-24 hours. After the reaction is completed, the solvent is first evaporated and then purified by column chromatography. The eluent used for column chromatography purification is a petroleum ether / ethyl acetate mixed solvent with a volume ratio of 10:1.

[0008] Preferably, the general structural formula of the metallocene polyalphaolefin oligomer is as follows: or Among them, a, b and c are independent of each other, and can take the same or different values. The range of values ​​for a, b and c is 3-19. Preferably, a, b, and c have the same value; Preferably, the metallocene polyalphaolefin oligomer is obtained by coordination polymerization of a metallocene catalyst system with one or more linear alpha-olefins, wherein the linear alpha-olefin has 6-20 carbon atoms. The metallocene catalyst system comprises at least one metallocene catalyst, which is an inorganic-organic complex containing at least one cyclic ring or cyclic ring derivative as a ligand and at least one group IVB transition element as a central atom.

[0009] Preferably, the group IVB transition element is selected from zirconium (Zr).

[0010] Furthermore, by weight percentage, the corresponding amounts of ultra-high molecular weight polyethylene film raw materials include: 75-85 wt% ultra-high molecular weight polyethylene, 5-15 wt% linear low-density polyethylene, and 5-15 wt% epoxidized metallocene polyalphaolefin oligomer.

[0011] In a second aspect, a method for preparing the above-mentioned ultra-high molecular weight polyethylene film includes: melt-blending ultra-high molecular weight polyethylene, linear low-density polyethylene and epoxidized metallocene polyalphaolefin oligomer and then extruding the mixture, followed by stretching and compounding at 200-300°C, 300-1000% stretch ratio and 0.1-1.0 MPa compressive strength, and finally cooling and shaping at room temperature.

[0012] Preferably, ultra-high molecular weight polyethylene, linear low-density polyethylene, and epoxidized metallocene polyalphaolefin oligomers are melt-blended at 180-250°C. Preferably, the extruded product is subjected to stretching and compounding at 220-250°C; Preferably, the extruded product is stretched and compounded using a stretching ratio of 400-800%. Preferably, the extruded product is subjected to stretching and compounding at a compressive strength of 0.4-0.6 MPa; Thirdly, a method for surface modification includes: immersing the above-described ultra-high molecular weight polyethylene film in an organic amine at room temperature to 100°C; The organic amine is selected from organic compounds including at least one amino group, wherein one or two hydrogen atoms in the amino group are replaced by hydrocarbon groups; Preferably, the organic amine is selected from one or more of the following: m-phenylenediamine, methylcyclohexanediamine, 4,4'-diaminodicyclohexylmethane, isophoronediamine, γ-aminopropyltriethoxysilane (KH550), N-β-aminoethyl-γ-aminopropyltrimethoxysilane (KH792), bis-(γ-trimethoxysilylpropyl)amine, and bis-(γ-triethoxysilylpropyl)amine; Preferably, the immersion temperature exceeds the melting point of the organic amine; Preferably, the soaking time is 1-24 hours.

[0013] Fourthly, a surface-modified ultra-high molecular weight polyethylene film is prepared by the surface modification method described above.

[0014] Fifthly, an ultra-high molecular weight polyethylene film-epoxy resin cured product-metal composite material, wherein the ultra-high molecular weight polyethylene film is selected from the ultra-high molecular weight polyethylene film described above or the surface-modified ultra-high molecular weight polyethylene film described above; The epoxy resin cured product is a three-dimensional network polymer formed by the chemical reaction between epoxy resin and its curing agent, and its raw materials are selected from liquid epoxy resin and curing agent. The metal is selected from: aluminum, copper, or corresponding alloys; Preferably, the liquid epoxy resin is selected from bisphenol A type epoxy resin; Preferably, the curing agent is selected from any one of aliphatic amines, cycloaliphatic amines, aromatic amines, acid anhydrides, or phenolic resins.

[0015] Sixthly, a method for preparing the above-mentioned ultra-high molecular weight polyethylene film-epoxy resin cured product-metal composite material includes: pre-mixing epoxy resin and curing agent evenly, coating the mixture onto the surface of the ultra-high molecular weight polyethylene film, and then bonding it to the metal surface and curing it to obtain the composite material. The curing temperature is from room temperature to 180°C; The curing pressure is 0.1-10 MPa; The curing time is 1-120 minutes.

[0016] The beneficial effects of the technical solution proposed in this application are as follows: An epoxidized metallocene polyalphaolefin (mPAO) oligomer is added as a compatibilizer to the ultra-high molecular weight polyethylene (UHMWPE) film raw material. Utilizing the similarity between the long hydrocarbon chains of mPAO and the chemical structures of UHMWPE and LLDPE, good compatibility and dispersibility of each component are ensured, particularly without disrupting the crystallization and orientation of UHMWPE, thus guaranteeing the excellent mechanical properties of the UHMWPE film. Furthermore, the epoxidation of the mPAO oligomer introduces epoxy groups, improving the polarity and initial adhesion of the UHMWPE film, and also providing reactive sites for subsequent surface modification.

[0017] Adding epoxidized mPAO directly to UHMWPE and LLDPE during processing can permanently and substantially increase the polarity of ultra-high molecular weight polyethylene films. Even if the surface is worn, the film still contains polar epoxy groups, avoiding the short-term effect of using surface treatment alone to increase polarity.

[0018] On the other hand, an organic amine immersion treatment scheme is proposed based on ultra-high molecular weight polyethylene film. Taking advantage of the high reactivity between amino and epoxy groups, organic amines or silane coupling agents containing organic amines are used to carry out ring-opening reactions with the epoxy groups on the surface, introducing amino or silanol groups with stronger polarity and reactivity. After bonding with epoxy resin, the physical anchoring is transformed into a stronger chemical covalent bond, realizing a fundamental change in the bonding failure mode from "interfacial failure" to "cohesive failure", while significantly improving the peel strength. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 The image shows the ATR-FTIR spectrum of the ultra-high molecular weight polyethylene film prepared in Example 1. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are for illustrative purposes only and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to enable a more thorough and comprehensive understanding of the disclosure of the present application. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0022] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] Furthermore, unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0024] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.

[0025] Unless otherwise specified in this application, experimental conditions are generally performed according to conventional conditions in the field or according to the conditions recommended by the reagent company. Unless otherwise specified, the materials and reagents used in the embodiments of this application can be purchased commercially.

[0026] All references to documents mentioned in this application are incorporated herein by reference as if each document were individually incorporated herein by reference. Unless they conflict with the inventive purpose and / or technical solution of this application, all cited documents are incorporated herein by reference in their entirety and for all purposes. When citing documents in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. When citing documents in this application, examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.

[0027] The preparation method of epoxidized metallocene polyalphaolefin oligomers refers to the method described in Chinese Patent CN120157975B. Polyalphaolefin oligomers are obtained through coordination polymerization of linear alphaolefins. Metallocene-siloxane-silicon-bridged zirconium dichloride is used as the main catalyst. After the reaction is completed, the fraction collected at 110-130℃ under a vacuum of 0.5 mmHg yields C10 metallocene polyalphaolefin dimers; the fraction collected at 140-160℃ under a vacuum of 0.5 mmHg yields C12 metallocene polyalphaolefin dimers; the fraction collected at 140-160℃ under a vacuum of 0.2 mmHg yields C10 metallocene polyalphaolefin trimers; and the fraction collected at 180-200℃ under a vacuum of 0.2 mmHg yields C12 metallocene polyalphaolefin trimers.

[0028] C10 / C12 / C14 metallocene polyalphaolefin dimers were added to a mixture of 88 wt% formic acid aqueous solution, 30 wt% hydrogen peroxide aqueous solution, 70 wt% sulfuric acid aqueous solution, and ethyl n-propyl ether solvent at a mass ratio of 1:0.15:0.75:0.05:0.75. The mixture was stirred at 90°C for 12 hours. After the reaction was completed, the azeotrope of water and ethyl n-propyl ether was removed by rotary evaporation. The mixture was then purified by column chromatography using a petroleum ether / ethyl acetate mixed solvent at a volume ratio of 10:1. The purified C10 / C12 epoxidized metallocene polyalphaolefin dimers and C10 / C12 epoxidized metallocene polyalphaolefin trimers were obtained.

[0029] Structural characterization of C10 epoxide metallocene polyalphaolefin dimers 13C-NMR (CDCl3 101 MHz): δ14.2 (2C), 22.8 (2C), 29.4-29.6 (6C), 29.6-29.7 (4C), 32.0 (2C), 36.7 (2C), 50.6, 59.7; Structural characterization of C10 epoxide metallocene polyalphaolefin trimer 13 C-NMR (CDCl3 101 MHz): δ14.1 (3C), 22.6-22.7 (3C), 26.5 (2C), 29.3-29.5 (9C), 29.5-29.6 (4C), 31.9(3C), 33.3 (2C), 36.4, 50.7, 59.8, 111.5; Structural characterization of C12 epoxide metallocene polyalphaolefin dimers 13 C-NMR (CDCl3 101 MHz): δ14.0-14.1 (2C), 22.8 (2C), 29.6-29.8 (6C), 29.5-29.6 (4C), 31.8 (2C), 36.4(2C), 50.5, 59.6; Structural characterization of C12 epoxide metallocene polyalphaolefin trimer 13 C-NMR (CDCl3 101 MHz): δ14.0-14.1 (3C), 22.7 (3C), 26.6 (2C), 29.4-29.5 (9C), 29.7 (10C), 32.0 (3C), 33.0-33.1 (2C), 36.3, 50.7, 59.3, 111.7.

[0030] Example 1

[0031] Ultra-high molecular weight polyethylene (UHMWPE) films were prepared using a co-extrusion molding process. The raw material composition included UHMWPE (YUHWA HIDEN U090) with a viscosity-average molecular weight of 9 × 10⁻⁶. 6 The composition consists of three components: mol / g, melting point 135℃ (Korean Oil & Chemical Corporation), linear low-density polyethylene 2045G (MFR=1.0g / 10min@190℃ / 2.16 kg load, ExxonMobil), and epoxidized metallocene polyalphaolefin oligomer, with corresponding amounts of: 80wt% UHMWPE, 8wt% linear low-density polyethylene 2045G, and 12wt% C10 epoxidized metallocene polyalphaolefin dimer.

[0032] The molding process of ultra-high molecular weight polyethylene film is as follows: UHMWPE, linear low-density polyethylene 2045G and C10 epoxidized metallocene polyalphaolefin dimer are melt-blended for 15 minutes and then extruded at 190°C. The film is then stretched and compounded at 235±10°C, 600% stretch ratio and 0.6MPa compressive strength. After stretching, the film is cooled and shaped at room temperature to obtain an ultra-high molecular weight polyethylene film with a thickness of (15±2)μm.

[0033] The ultra-high molecular weight polyethylene film prepared in Example 1 was cut into strips of 100×25mm and bonded to a 75×70×0.5mm copper foil substrate using epoxy resin adhesive. The bonded surfaces were coated with bisphenol A type epoxy resin (epoxy equivalent 184 g / mol, Leuna-Harze GmbH, Epilux A 19-03) and isophorone diamine curing agent (molecular weight 170.3 g / mol, active hydrogen equivalent 42.6 g / mol), with an epoxy resin to curing agent ratio of 100:23. The bonding and curing process was performed by pressing in a flat vulcanizing machine under curing conditions of 120°C, 8 MPa, and 30 minutes.

[0034] Example 2 The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 1 was immersed in m-phenylenediamine at 40°C for 20 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0035] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0036] Example 3

[0037] The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 1 was immersed in KH550 at room temperature for 24 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0038] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0039] Example 4

[0040] Ultra-high molecular weight polyethylene (UHMWPE) films were prepared using a co-extrusion molding process. The formulation and preparation process were the same as in Example 1, except that the surface layer consisted of 80 wt% UHMWPE, 10 wt% linear low-density polyethylene 2045G, and 10 wt% C10 epoxidized metallocene polyalphaolefin trimer.

[0041] Example 5

[0042] The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 4 was immersed in methylcyclohexanediamine at 40°C for 18 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0043] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0044] Example 6

[0045] The ultra-high molecular weight polyethylene (UHMWPE) film obtained from the cooling and shaping process of Example 4 was immersed in KH792 at room temperature for 18 hours to obtain a surface-modified UHMWPE film. Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated UHMWPE film, with the ratio of epoxy resin to curing agent being 100:22. The bonding and curing process was the same as in Example 1.

[0046] Example 7

[0047] Ultra-high molecular weight polyethylene (UHMWPE) films were prepared using a co-extrusion molding process. The formulation and preparation process were the same as in Example 1, except that the surface layer consisted of 80 wt% UHMWPE, 8 wt% linear low-density polyethylene 2045G, and 12 wt% C12 epoxidized metallocene polyalphaolefin dimer.

[0048] Example 8

[0049] The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 7 was immersed in 4,4'-diaminodicyclohexylmethane at 50°C for 24 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0050] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0051] Example 9

[0052] The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 7 was immersed in bis-(γ-trimethoxysilylpropyl)amine at room temperature for 18 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0053] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0054] Example 10

[0055] Ultra-high molecular weight polyethylene (UHMWPE) films were prepared using a co-extrusion molding process. The formulation and preparation process were the same as in Example 1, except that the surface layer consisted of 80 wt% UHMWPE, 10 wt% linear low-density polyethylene 2045G, and 10 wt% C12 epoxidized metallocene polyalphaolefin trimer.

[0056] Example 11

[0057] The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 10 was immersed in isophorone diamine at room temperature for 24 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0058] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0059] Example 12

[0060] The ultra-high molecular weight polyethylene film obtained by cooling and shaping in Example 10 was immersed in bis-(γ-triethoxysilylpropyl)amine at room temperature for 18 hours to obtain a surface-modified ultra-high molecular weight polyethylene film.

[0061] Subsequently, following the method of Example 1, epoxy resin and a curing agent were coated onto the adhesive surface of the treated ultra-high molecular weight polyethylene film, wherein the ratio of epoxy resin to curing agent was 100:22. The bonding and curing process was the same as in Example 1.

[0062] Comparative Example 1 Ultra-high molecular weight polyethylene (UHMWPE) films were prepared using a co-extrusion molding process. The raw material composition included UHMWPE (YUHWA HIDEN U090) with a viscosity-average molecular weight of 9 × 10⁻⁶. 6 The product contains three different components: mol / g, melting point 135℃, linear low-density polyethylene 2045G, and epoxidized metallocene polyalphaolefin oligomer. The corresponding composition includes: 80wt% UHMWPE, 10wt% linear low-density polyethylene 2045G, and 10wt% epoxidized soybean oil.

[0063] The molding process of ultra-high molecular weight polyethylene film is as follows: UHMWPE, linear low-density polyethylene 2045G and epoxidized soybean oil are melt-blended for 15 minutes and then extruded at 190°C. The ultra-high molecular weight polyethylene film is then stretched and laminated at 235±10°C, 600% elongation ratio and 0.6MPa compressive strength. After stretching, the film is cooled and shaped at room temperature to obtain an ultra-high molecular weight polyethylene film with a thickness of (15±2)μm.

[0064] The ultra-high molecular weight polyethylene film prepared in Example 1 was cut into strips of 100×25mm and bonded to a rigid copper foil substrate of 75×70×0.2mm using epoxy resin adhesive. The bonding surfaces were coated with bisphenol A type epoxy resin (epoxy equivalent 184g / mol, Leuna-Harze GmbH, Epilux A 19-03) and isophorone diamine curing agent (molecular weight 170.3g / mol, active hydrogen equivalent 42.6g / mol), wherein the ratio of epoxy resin to curing agent was 100:23. The bonding and curing process was carried out by pressing in a flat vulcanizing machine, and the curing conditions were 120°C, 8 MPa, and 30 minutes.

[0065] Comparative Example 2 The treatment method is the same as in Example 2, except that the ultra-high molecular weight polyethylene film prepared in Comparative Example 1 is used instead of the ultra-high molecular weight polyethylene film prepared in Example 1.

[0066] Comparative Example 3 The treatment method is the same as in Example 3, except that the ultra-high molecular weight polyethylene film prepared in Comparative Example 1 is used instead of the ultra-high molecular weight polyethylene film prepared in Example 1.

[0067] Performance testing section The mechanical properties of the ultra-high molecular weight polyethylene (UHMWPE) films obtained by cooling and shaping in Examples 1, 4, 7, 10, and Comparative Example 1, as well as the UHMWPE films obtained by soaking in organic amines (Examples 2-3, 5-6, 8-9, 11-12, and Comparative Example 2-3), were tested in accordance with the standard GB / T 1040.2-2022. The tensile strength and elongation at break of different UHMWPE film samples were tested accordingly.

[0068] Water contact angle test: Referring to the standard ISO 15989:2004, the water contact angle of different ultra-high molecular weight polyethylene film samples was tested. The contact angle test software was used to fit the contact angle of the water droplet on both sides of the film surface, and the average value was taken to calculate the water contact angle.

[0069] Peel strength test: Referring to the 180° peel strength test standard in ISO 8510-2:2006, the 180° peel strength of different ultra-high molecular weight polyethylene film samples after being coated with epoxy resin and curing agent and then thermo-cured was tested, as well as the failure mode of the contact interface between the polyethylene film sample and the copper foil after peeling.

[0070] Infrared spectroscopy test: The ultra-high molecular weight polyethylene film prepared in Example 1 was tested for infrared absorption by ATR-FTIR. Analysis of the infrared spectrum showed that the absorption was within the range of 900-920 cm⁻¹. -1 The marker peak of the epoxy group appears at the location.

[0071] The test results are recorded in Table 1.

[0072] Analysis of the data in Table 1 shows that the ultra-high molecular weight polyethylene films prepared in Examples 1-12 have excellent mechanical properties and a certain degree of adhesion to the strongly polar epoxy resin system. The epoxy resin itself contains polar epoxy groups and hydroxyl groups, which make it difficult to form an interfacial interaction with the originally non-polar ultra-high molecular weight polyethylene film surface. By introducing epoxidized metallocene polyalphaolefin oligomers into the film surface layer, the content of oxygen-containing polar functional groups in the surface layer is increased, thereby enhancing the interaction with the epoxy resin system.

[0073] Based on Examples 1, 4, 7, and 10, ultra-high molecular weight polyethylene film was immersed in organic amine, allowing the epoxy and amino groups on the surface to undergo a ring-opening reaction beforehand, forming corresponding imino and hydroxyl groups. This further increased the content of polar groups on the surface of the ultra-high molecular weight polyethylene film, thereby further enhancing its interaction with the epoxy resin system.

[0074] Table 1

[0075] Comparative Example 1 used epoxidized soybean oil instead of epoxidized metallocene polyalphaolefin oligomers. Epoxidized soybean oil contains ester bonds and has significantly higher polarity than polyethylene resin, resulting in poor compatibility and difficulty in forming a homogeneous phase. As a low-molecular-weight additive in the surface layer, epoxidized soybean oil hinders the orientation and crystallization of UHMWPE molecular chains during stretching, which is crucial for the high strength of ultra-high molecular weight polyethylene films. Therefore, the mechanical properties of the ultra-high molecular weight polyethylene films prepared in Comparative Examples 1-3 are significantly reduced, while the peel strength is not significantly improved compared to Examples 1-12.

[0076] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Although the specific embodiments of the present invention have been described above, they are not intended to limit the protection scope of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A type of ultra-high molecular weight polyethylene film, characterized in that, The raw material composition includes ultra-high molecular weight polyethylene, linear low-density polyethylene, and epoxidized metallocene polyalphaolefin oligomers; The viscosity-average molecular weight of the ultra-high molecular weight polyethylene is (1×10⁻⁶). 6 -9×10 6 )mol / g; The linear low-density polyethylene is a resin obtained by polymerizing ethylene with higher α-olefin monomers. It is a low-density polyethylene with short-chain molecular chains. The melt flow rate of the linear low-density polyethylene tested according to ASTM D1238 is 0.5-3.0 (g / 10min@190℃ / 2.16 kg load). The degree of polymerization of the epoxidized metallocene polyalphaolefin oligomer is 2-4.

2. The ultra-high molecular weight polyethylene film according to claim 1, characterized in that, The structure of the epoxidized metallocene polyalphaolefin oligomer is selected from: or Wherein, a, b, and c are independent of each other, and their values ​​may be the same or different. The value range of a, b, and c is 3-19. And / or, the epoxidized metallocene polyalphaolefin oligomer is obtained by epoxidation of metallocene polyalphaolefin oligomer. The epoxidation reaction specifically includes: reacting metallocene polyalphaolefin oligomer, 88wt% formic acid aqueous solution, 30wt% hydrogen peroxide aqueous solution, 70wt% sulfuric acid aqueous solution, and solvent ethyl n-propyl ether in a mass ratio of 1:0.15:0.75:0.05:0.75 at a temperature of 60-120℃ for 1-24 hours. After the reaction is completed, the solvent is first evaporated and then purified by column chromatography. The eluent used for column chromatography purification is a petroleum ether / ethyl acetate mixed solvent with a volume ratio of 10:

1.

3. The ultra-high molecular weight polyethylene film according to claim 1, characterized in that, The amount of ultra-high molecular weight polyethylene film raw material used, by weight percentage, includes: 75-85 wt% ultra-high molecular weight polyethylene, 5-15 wt% linear low density polyethylene, and 5-15 wt% epoxidized metallocene polyalphaolefin oligomer.

4. A method for preparing an ultra-high molecular weight polyethylene film as described in any one of claims 1-3, characterized in that, Ultra-high molecular weight polyethylene, linear low-density polyethylene, and epoxidized metallocene polyalphaolefin oligomers are melt-blended and extruded, then stretched and compounded at 200-300℃, 300-1000% elongation and 0.1-1.0MPa compressive strength, and finally cooled and shaped at room temperature.

5. The method for preparing ultra-high molecular weight polyethylene film according to claim 4, characterized in that, Ultra-high molecular weight polyethylene, linear low-density polyethylene and epoxidized metallocene polyalphaolefin oligomers were melt-blended at 180-250℃. And / or, stretching and compounding the extruded product at 220-250°C; And / or, stretch compounding of extruded products using a stretch ratio of 400-800%; And / or, stretching the extruded product under a compressive strength of 0.4-0.6 MPa.

6. A method for surface modification of ultra-high molecular weight polyethylene film, characterized in that, The ultra-high molecular weight polyethylene film according to any one of claims 1-3 is immersed in organic amine at room temperature to 100°C; The organic amine is selected from organic compounds including at least one amino group, wherein one or two hydrogen atoms in the amino group are replaced by hydrocarbon groups.

7. The method for surface modification of ultra-high molecular weight polyethylene film according to claim 6, characterized in that, The organic amine is selected from one or more of the following: m-phenylenediamine, methylcyclohexanediamine, 4,4'-diaminodicyclohexylmethane, isophoronediamine, γ-aminopropyltriethoxysilane (KH550), N-β-aminoethyl-γ-aminopropyltrimethoxysilane (KH792), bis-(γ-trimethoxysilylpropyl)amine, and bis-(γ-triethoxysilylpropyl)amine; And / or, the immersion temperature exceeds the melting point of the organic amine; And / or, the soaking time is 1-24 hours.

8. A surface-modified ultra-high molecular weight polyethylene film, characterized in that, It is prepared by the surface modification method as described in any one of claims 6-7.

9. A composite material of ultra-high molecular weight polyethylene film-epoxy resin cured product-metal, characterized in that, The ultra-high molecular weight polyethylene film is selected from the ultra-high molecular weight polyethylene film as described in any one of claims 1-3 or the surface-modified ultra-high molecular weight polyethylene film as described in any one of claims 6-7. The epoxy resin cured product is a three-dimensional network polymer formed by the chemical reaction between epoxy resin and its curing agent, and its raw materials are selected from liquid epoxy resin and curing agent. The metal is selected from aluminum, copper, or corresponding alloys.

10. A method for preparing the ultra-high molecular weight polyethylene film-epoxy resin cured product-metal composite material as described in claim 9, characterized in that, The epoxy resin and curing agent are pre-mixed evenly, coated on the surface of ultra-high molecular weight polyethylene film, and then bonded to the metal surface and cured. The curing temperature is from room temperature to 180°C; The curing pressure is 0.1-10 MPa; The curing time is 1-120 minutes.

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