A resin composition for bonding polyolefin materials and a method for preparing the same

Abstract

The present application belongs to the technical field of polymer adhesive material, and particularly relates to a resin composition for bonding polyolefin material and a preparation method thereof. The present application is prepared by formula screening optimization, and the ratio of the storage modulus E'30 at 30 DEG C to the storage modulus E'130 at 130 DEG C is greater than 100. The polyurethane resin is used in combination with butadiene-styrene copolymer with butadiene content greater than 60% and butadiene-styrene-vinylpyridine copolymer, so that the adhesive with good fusion and good adhesion to polyethylene base material is obtained. The allyl silicon modified pyridine monomer, allyl silicon modified carbazole monomer and lauryl acrylate are polymerized, and the prepared acrylate polymer is used in combination with the polyurethane resin. The pyridine group, tertiary butyl group, carbazole group and silicon atom in the acrylate polymer and the dodecyl group in the lauryl acrylate are used to improve the adhesion strength to the polyolefin base material.

Description

Technical Field

[0001] This invention belongs to the field of polymer adhesive materials technology, specifically a resin composition for bonding polyolefin materials and its preparation method. Background Technology

[0002] Polyolefins are materials with excellent overall physicochemical properties and a wide range of applications. In some cases, they are used as composite materials, such as bulletproof plates made of unidirectional ultra-high molecular weight polyethylene fiber fabric bonded with resin, and polypropylene car bumpers. However, polyolefins have low surface energy, making them difficult to adhere to, resulting in poor interfacial bonding in the composite materials.

[0003] In the manufacture of unidirectional, non-woven, ultra-high molecular weight polyethylene (UHMWPE) fiber-based composites used in bulletproof products, the resin plays a crucial role in bonding the polyethylene fibers into a cohesive whole. Adjacent layers of unidirectional fiber fabric are perpendicular to each other and are fixed together by resin bonding between the layers. During processing, the unidirectional fiber fabric is typically first impregnated, padded, or coated to create a single-layer resin / fiber composite. Then, multiple layers are stacked and heated and pressurized (including vacuum hot pressing) to create a multilayer product. The resulting multilayer composite requires both good adhesion between the resin and fibers and the ability of the resin layers to fuse together under hot pressing to form a completely continuous resin phase. If adjacent resin layers cannot fuse, a weak interface is created, preventing the formation of a continuous resin phase and thus affecting the mechanical properties of the composite material.

[0004] To improve adhesion to polyolefins, patent EP0191306B1 discloses a composite material of ultra-high molecular weight polyethylene fiber and a block copolymer. The disclosed method involves impregnating the fiber with the block copolymer dissolved in a solvent. This method requires a solvent, and the block copolymer is obtained through directional polymerization, resulting in high costs.

[0005] Therefore, in order to achieve good adhesion to polyolefin substrates and form an integral whole with polyolefin substrates under molding conditions, it is urgent to develop a bonding resin suitable for polyolefin composites. Summary of the Invention

[0006] To address the above problems, this invention provides a resin composition for bonding polyolefin materials and its preparation method, which solves the problem of poor interfacial bonding strength when using adhesives to prepare polyolefin composite materials.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A resin composition for bonding polyolefin materials comprises a polyurethane resin and an elastomer resin; wherein the ratio of the storage modulus of the polyurethane resin at 30°C to its storage modulus at 130°C is ≥100; the elastomer resin is a butadiene-styrene-vinylpyridine copolymer, a butadiene-styrene copolymer, or an acrylate polymer; the butadiene-styrene-vinylpyridine copolymer or the butadiene-styrene copolymer contains not less than 60% butadiene; the acrylate polymer is prepared by polymerization of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, and lauryl acrylate, wherein the structure of the allylsilane-modified pyridine monomer is as follows:

[0009] ;

[0010] The structure of the allylsilane-modified carbazole monomer is as follows:

[0011] .

[0012] Preferably, the mass ratio of the polyurethane resin to the elastomer resin is 24~75:25~76.

[0013] Preferably, the butadiene-styrene-vinylpyridine copolymer contains 65-70% butadiene.

[0014] Preferably, the butadiene-styrene copolymer contains 65-85% butadiene.

[0015] Preferably, the mass ratio of the allylsilane-modified pyridine monomer, the allylsilane-modified carbazole monomer, and the lauryl acrylate is 2~3:1~2:3.5~5.

[0016] Preferably, the initiator used in the polymerization reaction is ammonium persulfate, and the mass of ammonium persulfate is 1.5-3% of the sum of the masses of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, and lauryl acrylate; the polymerization reaction temperature is 80-85°C, and the time is 5-8 hours.

[0017] Preferably, the polymerization reaction is carried out in a solvent consisting of water and ethanol, and an emulsifier, namely sodium dodecyl sulfate, is also added during the polymerization reaction.

[0018] Preferably, the allylsilane-modified pyridine monomer is prepared by reacting 4-tert-butylaminopyridine with n-butyllithium and then with allyl dimethylchlorosilane, wherein the molar ratio of 4-tert-butylaminopyridine, n-butyllithium and allyl dimethylchlorosilane is 1:1:1.1~1.2.

[0019] Preferably, the allylsilane-modified carbazole monomer is prepared by reacting 3,6-di-tert-butylcarbazole with n-butyllithium and then with allyl dimethylchlorosilane, wherein the molar ratio of 3,6-di-tert-butylcarbazole, n-butyllithium and allyl dimethylchlorosilane is 1:1:1.1~1.2.

[0020] A method for preparing a resin composition for bonding polyolefin materials as described above includes the following steps: mixing a polyurethane aqueous dispersion and an elastomer resin emulsion, followed by drying and molding to obtain a resin composition for bonding polyolefin materials.

[0021] When the resin composition for bonding polyolefin materials of the present invention is used to bond polyethylene resin, the resin composition for bonding polyolefin materials is placed between the polyethylene resins to be bonded and then hot-pressed at a temperature of 130~135°C.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) Through formulation screening and optimization, the present invention selects polyurethane resin with a ratio of storage modulus E'30 at 30°C to storage modulus E'130 at 130°C greater than 100, and uses it in combination with butadiene-styrene copolymer and butadiene-styrene-vinylpyridine copolymer with butadiene content greater than 60% to obtain an adhesive with good fusion properties and good adhesion to polyethylene substrate.

[0024] (2) This invention uses the polymerization reaction of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer and lauryl acrylate, and then uses the resulting acrylate in combination with polyurethane resin. The pyridine group, tert-butyl group, carbazole group and silicon atom in the allylsilane-modified pyridine monomer and allylsilane-modified carbazole monomer, as well as the dodecyl group in lauryl acrylate, give the acrylate good toughness and strength. The polar pyridine group and carbazole group, non-polar silicon atom, tert-butyl group and dodecyl group give the acrylate good surface activity, which improves the affinity and attraction to polyolefin substrates. The steric hindrance effect, physical winding effect and chemical effect of pyridine group, carbazole group and tert-butyl group are used to further improve the adhesion strength to polyolefin substrates. Attached Figure Description

[0025] Figure 1 The 1H NMR spectrum of the allylsilane-modified pyridine monomer prepared in Example 9 of this invention;

[0026] Figure 2 The 1H NMR spectrum of the allylsilane-modified carbazole monomer prepared in Example 9 of this invention;

[0027] Figure 3This is a schematic diagram showing the change of the storage modulus of conventional polyurethane resin with temperature in this invention.

[0028] Figure 4 This is a schematic diagram of the stacked composition used to test the adhesion of polyethylene film material in this invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution, the present invention will be described in detail below with reference to embodiments. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0030] Example 1

[0031] The resin composition for bonding polyolefin materials in this embodiment consists of polyurethane resin and butadiene-styrene-vinylpyridine copolymer, with a mass ratio of polyurethane resin to butadiene-styrene-vinylpyridine copolymer of 24:76.

[0032] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene-vinylpyridine copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Baybond® PU330, manufactured by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 30%; the butadiene-styrene-vinylpyridine copolymer emulsion is Pyratex® 221, manufactured by Trinseo, with a non-volatile content of 40.5% and a butadiene content of 70% in the copolymer.

[0033] Example 2

[0034] The only difference between the resin composition for bonding polyolefin materials in this embodiment and the resin composition for bonding polyolefin materials in Example 1 is that the mass ratio of polyurethane resin to butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this embodiment is 42.6:57.4.

[0035] Example 3

[0036] The only difference between the resin composition for bonding polyolefin materials in this embodiment and the resin composition for bonding polyolefin materials in Example 1 is that the mass ratio of polyurethane resin and butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this embodiment is 75:25.

[0037] Example 4

[0038] The only difference between the resin composition for bonding polyolefin materials in this embodiment and the resin composition for bonding polyolefin materials in Example 1 is that the polyurethane aqueous dispersion used in the preparation of the resin composition for bonding polyolefin materials in this embodiment is Bayhydrol® UH240, manufactured by Covestro, which is an aqueous thermally activated polyurethane dispersion with a non-volatile content of 40%; and the mass ratio of polyurethane resin to butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this embodiment is 30:70.

[0039] Example 5

[0040] The only difference between the resin composition for bonding polyolefin materials in this embodiment and the resin composition for bonding polyolefin materials in Example 4 is that the mass ratio of polyurethane resin and butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this embodiment is 50:50.

[0041] Example 6

[0042] The resin composition for bonding polyolefin materials in this embodiment consists of polyurethane resin and butadiene-styrene copolymer, with a mass ratio of polyurethane resin to butadiene-styrene copolymer of 38:62.

[0043] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thereby obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Bayhydrol® UH240, manufactured by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 40%; the butadiene-styrene copolymer emulsion is EL5570, manufactured by Enichem, with a non-volatile content of 66%, and the copolymer contains 74% butadiene.

[0044] Example 7

[0045] The resin composition for bonding polyolefin materials in this embodiment consists of polyurethane resin and butadiene-styrene copolymer, with a mass ratio of polyurethane resin to butadiene-styrene copolymer of 43:57.

[0046] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Baybond® PU330, manufactured by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 30%; the butadiene-styrene copolymer emulsion is SBR-1, manufactured by Yatai Chemical, with a non-volatile content of 50%, and the copolymer contains 85% butadiene.

[0047] Example 8

[0048] The resin composition for bonding polyolefin materials in this embodiment consists of polyurethane resin and butadiene-styrene copolymer in a mass ratio of 50:50.

[0049] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Bayhydrol® UH240, produced by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 40%; the butadiene-styrene copolymer emulsion is SBR-1, produced by Yatai Chemical, with a non-volatile content of 50%, and the copolymer contains 85% butadiene.

[0050] Example 9

[0051] The resin composition for bonding polyolefin materials in this embodiment consists of polyurethane resin and acrylate polymer, with a mass ratio of polyurethane resin to acrylate polymer of 40:60.

[0052] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps:

[0053] (1) 0.02 mol of 4-tert-butylaminopyridine, 0.02 mol of tetramethylethylenediamine and 80 mL of anhydrous tetrahydrofuran were added to a dried stirred tank under nitrogen protection. The mixture was cooled to -78 °C under nitrogen atmosphere. Under stirring, a hexane solution of n-butyllithium with a concentration of 2.2 mol / L (the amount of n-butyllithium in the hexane solution of n-butyllithium was 0.02 mol) was slowly added dropwise. After the addition was completed, the reaction was stirred at -78 °C for 2 h to obtain a lithium pyridine salt solution.

[0054] 0.022 mol of allyl dimethylchlorosilane was added to 20 mL of anhydrous tetrahydrofuran. After stirring, the mixture was cooled to -78 °C. Under nitrogen protection and stirring conditions at -78 °C, a lithium pyridine salt solution was added dropwise to the allyl dimethylchlorosilane tetrahydrofuran solution. After the addition was complete, the mixture was allowed to rise naturally to room temperature, and the reaction was continued with stirring for 12 h. After the reaction was completed, 50 mL of saturated ammonium chloride solution was added to quench the reaction. The mixture was separated, and the organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. After filtration, the filtrate was distilled under reduced pressure to remove the solvent, yielding the crude product. The crude product was then mixed with a mixed solvent consisting of n-hexane and toluene in a volume ratio of 3:1 (the crude product was then dissolved in water). The crude product was heated to 65°C in a water bath with a mixed solvent (mass ratio of 1:3) and stirred until fully dissolved. It was then filtered while hot to remove insoluble impurities. The filtrate was allowed to cool naturally to room temperature and then transferred to a 5°C refrigerator for static cooling and crystallization for 8 hours. The filtrate was filtered while cold and washed three times with a mixed solvent (pre-cooled to 5°C) consisting of n-hexane and toluene in a volume ratio of 3:1 (each wash using 1.2 times the mass of the mixed solvent). The washed filter cake was then transferred to a vacuum drying oven and dried for 12 hours at 45°C and -0.090 to -0.095 MPa to obtain a white solid product, which is the allylsilane-modified pyridine monomer. The chemical structure of 4-tert-butylaminopyridine is as follows:

[0055] ;

[0056] The chemical structure of allyl dimethylchlorosilane is as follows:

[0057] ;

[0058] The 1H NMR spectrum of allylsilane-modified pyridine monomer is shown below. Figure 1 As shown, the chemical structure is as follows:

[0059] .

[0060] (2) 0.012 mol of 3,6-di-tert-butylcarbazole, 0.012 mol of tetramethylethylenediamine and 70 mL of anhydrous tetrahydrofuran were added to a stirred tank filled with nitrogen. Under nitrogen atmosphere, the mixture was cooled to -78 °C. Under stirring, a hexane solution of n-butyllithium with a concentration of 2.2 mol / L (the amount of n-butyllithium in the hexane solution of n-butyllithium was 0.012 mol) was slowly added dropwise. After the addition was completed, the reaction was stirred at -78 °C for 2 h to obtain a carbazole lithium salt solution.

[0061] 0.013 mol of allyl dimethylchlorosilane was added to 20 mL of anhydrous tetrahydrofuran, stirred until homogeneous, and then cooled to -78 °C. Under nitrogen protection and stirring conditions at -78 °C, a carbazole lithium salt solution was added dropwise to the allyl dimethylchlorosilane tetrahydrofuran solution. After the addition was complete, the mixture was allowed to rise naturally to room temperature, and the reaction was continued with stirring for 12 h. After the reaction was completed, 50 mL of saturated ammonium chloride solution was added to quench the reaction. The mixture was separated, and the organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. The solution was filtered, and the solvent was removed by vacuum distillation of the filtrate to obtain a concentrate. The concentrate and a mixed solvent consisting of n-hexane and toluene in a volume ratio of 3:1 (the mass ratio of crude product to mixed solvent was 1:3) were placed in a water bath and heated to 70 °C. The mixture was stirred until the crude product was fully dissolved, and then filtered while hot to remove insoluble impurities. After the filtrate was naturally cooled to room temperature, it was placed in a 3°C refrigerator for static cooling and crystallization for 6 hours. The crystals were then filtered while cold. The filter cake was washed three times with a mixed solvent of n-hexane and toluene (volume ratio 3:1) pre-cooled to 3°C (each wash using 1.5 times the mass of the mixed solvent). The washed filter cake was transferred to a vacuum drying oven and dried for 12 hours at 45°C and -0.090 to -0.095 MPa to obtain allylsilane-modified carbazole monomer. The 1H NMR spectrum of the allylsilane-modified carbazole monomer is shown below. Figure 2 As shown, the chemical structure is as follows:

[0062] .

[0063] (3) Add allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, lauryl acrylate and ethanol into a stirred tank and stir evenly to obtain a monomer mixture. The mass fraction of ethanol in the monomer mixture is 25%, and the mass ratio of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer and lauryl acrylate is 2:1:3.5.

[0064] Water, sodium dodecyl sulfate, and ammonium persulfate were added to a reaction vessel, stirred until homogeneous, and then heated to 80°C. The monomer mixture was then added to the reaction vessel under stirring conditions, and the mixture was stirred for 5 hours to obtain an acrylate polymer emulsion. The mass of ammonium persulfate was 1.5% of the sum of the masses of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, and lauryl acrylate, and the mass of sodium dodecyl sulfate was 2% of the sum of the masses of water and the monomer mixture. The mass ratio of water to monomer mixture was 4:6.

[0065] (4) The polyurethane aqueous dispersion and the acrylate polymer emulsion prepared in step (3) are stirred evenly to obtain a mixture. 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm×60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining a resin composition for bonding polyolefin materials. Among them, the polyurethane aqueous dispersion is Baybond® PU330, produced by Covestro, which is a water-based thermally activated polyurethane dispersion with a non-volatile content of 30%.

[0066] Example 10

[0067] The resin composition for bonding polyolefin materials in this embodiment consists of polyurethane resin and acrylate polymer, with a mass ratio of polyurethane resin to acrylate polymer of 60:40.

[0068] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps:

[0069] (1) 0.02 mol of 4-tert-butylaminopyridine, 0.02 mol of tetramethylethylenediamine and 80 mL of anhydrous tetrahydrofuran were added to a dried stirred tank under nitrogen protection. The mixture was cooled to -78 °C under nitrogen atmosphere. Under stirring, a hexane solution of n-butyllithium with a concentration of 2.2 mol / L (the amount of n-butyllithium in the hexane solution of n-butyllithium was 0.02 mol) was slowly added dropwise. After the addition was completed, the reaction was stirred at -78 °C for 2 h to obtain a lithium pyridine salt solution.

[0070] 0.022 mol of allyl dimethylchlorosilane was added to 20 mL of anhydrous tetrahydrofuran. After stirring, the mixture was cooled to -78 °C. Under nitrogen protection and stirring conditions at -78 °C, a lithium pyridine salt solution was added dropwise to the allyl dimethylchlorosilane tetrahydrofuran solution. After the addition was complete, the mixture was allowed to rise naturally to room temperature, and the reaction was continued with stirring for 12 h. After the reaction was completed, 50 mL of saturated ammonium chloride solution was added to quench the reaction. The mixture was separated, and the organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. After filtration, the filtrate was distilled under reduced pressure to remove the solvent, yielding the crude product. The crude product was then mixed with a mixed solvent consisting of n-hexane and toluene in a volume ratio of 3:1 (the crude product was then dissolved in water). The crude product was heated to 65°C in a water bath with a mixed solvent (mass ratio of 1:3) and stirred until fully dissolved. It was then filtered while hot to remove insoluble impurities. The filtrate was allowed to cool naturally to room temperature and then transferred to a 5°C refrigerator for static cooling and crystallization for 8 hours. The filtrate was filtered while cold and washed three times with a mixed solvent (pre-cooled to 5°C) consisting of n-hexane and toluene in a volume ratio of 3:1 (each wash using 1.2 times the mass of the mixed solvent). The washed filter cake was then transferred to a vacuum drying oven and dried for 12 hours at 45°C and -0.090 to -0.095 MPa to obtain a white solid product, which is the allylsilane-modified pyridine monomer. The chemical structure of 4-tert-butylaminopyridine is as follows:

[0071] ;

[0072] The chemical structure of allyl dimethylchlorosilane is as follows:

[0073] ;

[0074] The chemical structure of the allylsilane-modified pyridine monomer is shown below:

[0075] .

[0076] (2) 0.012 mol of 3,6-di-tert-butylcarbazole, 0.012 mol of tetramethylethylenediamine and 70 mL of anhydrous tetrahydrofuran were added to a stirred tank filled with nitrogen. Under nitrogen atmosphere, the mixture was cooled to -78 °C. Under stirring, a hexane solution of n-butyllithium with a concentration of 2.2 mol / L (the amount of n-butyllithium in the hexane solution of n-butyllithium was 0.012 mol) was slowly added dropwise. After the addition was completed, the reaction was stirred at -78 °C for 2 h to obtain a carbazole lithium salt solution.

[0077] 0.013 mol of allyl dimethylchlorosilane was added to 20 mL of anhydrous tetrahydrofuran, stirred until homogeneous, and then cooled to -78 °C. Under nitrogen protection and stirring conditions at -78 °C, a carbazole lithium salt solution was added dropwise to the allyl dimethylchlorosilane tetrahydrofuran solution. After the addition was complete, the mixture was allowed to rise naturally to room temperature, and the reaction was continued with stirring for 12 h. After the reaction was completed, 50 mL of saturated ammonium chloride solution was added to quench the reaction. The mixture was separated, and the organic phase was washed with saturated brine and dried with anhydrous sodium sulfate. The solution was filtered, and the solvent was removed by vacuum distillation of the filtrate to obtain a concentrate. The concentrate and a mixed solvent consisting of n-hexane and toluene in a volume ratio of 3:1 (the mass ratio of crude product to mixed solvent was 1:3) were placed in a water bath and heated to 70 °C. The mixture was stirred until the crude product was fully dissolved, and then filtered while hot to remove insoluble impurities. After the filtrate was naturally cooled to room temperature, it was placed in a 3°C refrigerator for static cooling and crystallization for 6 hours. The crystals were then filtered while cold. The filter cake was washed three times with a mixed solvent of n-hexane and toluene (volume ratio 3:1) pre-cooled to 3°C (each wash using 1.5 times the mass of the mixed solvent). The washed filter cake was transferred to a vacuum drying oven and dried for 12 hours at 45°C and -0.090 to -0.095 MPa to obtain allylsilane-modified carbazole monomer. The chemical structure of the allylsilane-modified carbazole monomer is shown below:

[0078] .

[0079] (3) Add allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, lauryl acrylate and ethanol into a stirring tank and stir evenly to obtain a monomer mixture. The mass fraction of ethanol in the monomer mixture is 30%, and the mass ratio of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer and lauryl acrylate is 3:2:5.

[0080] Water, sodium dodecyl sulfate, and ammonium persulfate were added to a reaction vessel, stirred until homogeneous, and then heated to 85°C. The monomer mixture was then added to the reaction vessel under stirring conditions, and the mixture was stirred for 8 hours to obtain an acrylate polymer emulsion. The mass of ammonium persulfate was 3% of the sum of the masses of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, and lauryl acrylate, and the mass of sodium dodecyl sulfate was 3% of the sum of the masses of water and the monomer mixture. The mass ratio of water to the monomer mixture was 5:7.

[0081] (4) The polyurethane aqueous dispersion and the acrylate polymer emulsion prepared in step (3) are stirred evenly to obtain a mixture. 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm×60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining a resin composition for bonding polyolefin materials. Among them, the polyurethane aqueous dispersion is Baybond® PU330, produced by Covestro, which is a water-based thermally activated polyurethane dispersion with a non-volatile content of 30%.

[0082] Comparative Example 1

[0083] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 1 is that the mass of the butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this comparative example is 0.

[0084] Comparative Example 2

[0085] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 1 is that the mass of polyurethane resin in the resin composition for bonding polyolefin materials in this comparative example is 0.

[0086] Comparative Example 3

[0087] The resin composition for bonding polyolefin materials in this comparative example consists of polyurethane resin and butadiene-styrene-vinylpyridine copolymer in a mass ratio of 50:50.

[0088] The method for preparing the resin composition for bonding polyolefin materials in this embodiment includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene-vinylpyridine copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Impranil® DLN-SD, manufactured by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 40%; the butadiene-styrene-vinylpyridine copolymer emulsion is Pyratex® 221, manufactured by Trinseo, with a non-volatile content of 40.5% and a butadiene content of 70% in the copolymer.

[0089] Comparative Example 4

[0090] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Comparative Example 3 is that the mass of the butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this comparative example is 0.

[0091] Comparative Example 5

[0092] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Comparative Example 3 is that the polyurethane aqueous dispersion used in the preparation of the resin composition for bonding polyolefin materials in this comparative example is Impranil® DL2611, manufactured by Covestro, which is an aqueous, non-thermally activated polyurethane dispersion with a non-volatile content of 40%.

[0093] Comparative Example 6

[0094] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Comparative Example 3 is that the polyurethane aqueous dispersion used in the preparation of the resin composition for bonding polyolefin materials in this comparative example is Impranil® DLH, manufactured by Covestro, which is an aqueous thermally activated polyurethane dispersion with a non-volatile content of 40%.

[0095] Comparative Example 7

[0096] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 4 is that the mass of the butadiene-styrene-vinylpyridine copolymer in the resin composition for bonding polyolefin materials in this comparative example is 0.

[0097] Comparative Example 8

[0098] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 6 is that the mass of polyurethane resin in the resin composition for bonding polyolefin materials in this comparative example is 0.

[0099] Comparative Example 9

[0100] The resin composition for bonding polyolefin materials in this comparative example consists of polyurethane resin and butadiene-styrene copolymer in a mass ratio of 50:50.

[0101] The preparation method of the resin composition for bonding polyolefin materials in this comparative example includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Bayhydrol® UH240, manufactured by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 40%; the butadiene-styrene copolymer emulsion is Ligos A3698, manufactured by Trinseo, and contains 45% butadiene in the copolymer.

[0102] Comparative Example 10

[0103] The resin composition for bonding polyolefin materials in this comparative example consists of polyurethane resin and butadiene-styrene copolymer in a mass ratio of 50:50.

[0104] The preparation method of the resin composition for bonding polyolefin materials in this comparative example includes the following steps: a polyurethane aqueous dispersion and a butadiene-styrene copolymer emulsion are stirred evenly to obtain a mixture; 8g of the mixture is poured into a polytetrafluoroethylene mold with a cavity size of 120mm × 60mm, placed horizontally, and dried at room temperature to form a film, thus obtaining the resin composition for bonding polyolefin materials. The polyurethane aqueous dispersion is Impranil® DLN-SD, manufactured by Covestro, and is an aqueous, thermally activated polyurethane dispersion with a non-volatile content of 40%; the butadiene-styrene copolymer emulsion is SBR-1, manufactured by Yatai Chemical, with a non-volatile content of 50%, and the copolymer contains 85% butadiene.

[0105] Comparative Example 11

[0106] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 7 is that the mass of polyurethane resin in the resin composition for bonding polyolefin materials in this comparative example is 0.

[0107] Comparative Example 12

[0108] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that the allylsilane-modified carbazole monomer in step (3) of the preparation of the resin composition for bonding polyolefin materials in this comparative example is replaced with N-vinylcarbazole.

[0109] Comparative Example 13

[0110] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that 3,6-di-tert-butylcarbazole is replaced with carbazole in step (2) of the preparation of the resin composition for bonding polyolefin materials in this comparative example.

[0111] Comparative Example 14

[0112] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that the allylsilane-modified pyridine monomer in step (3) of the preparation of the resin composition for bonding polyolefin materials in this comparative example is replaced with 4-vinylpyridine.

[0113] Comparative Example 15

[0114] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that lauryl acrylate is replaced with hexyl acrylate in step (3) of the preparation of the resin composition for bonding polyolefin materials in this comparative example.

[0115] Comparative Example 16

[0116] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that lauryl acrylate is replaced with octadecyl acrylate in step (3) of the preparation of the resin composition for bonding polyolefin materials in this comparative example.

[0117] Comparative Example 17

[0118] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that the amount of allylsilane-modified pyridine monomer used in step (3) of the preparation of the resin composition for bonding polyolefin materials in this comparative example is 0.

[0119] Comparative Example 18

[0120] The only difference between the resin composition for bonding polyolefin materials in this comparative example and the resin composition for bonding polyolefin materials in Example 9 is that the amount of allylsilane-modified carbazole monomer used in step (3) of the preparation of the resin composition for bonding polyolefin materials in this comparative example is 0.

[0121] Experimental Example 1

[0122] This experimental example is used to test the dynamic mechanical properties of the polyurethane resins used in the various embodiments and comparative examples. The storage modulus of conventional polyurethane resins as a function of temperature is shown in the figure below. Figure 3 As shown. Figure 3 The blue line represents polyurethane resin, which is a heat-softening resin. This resin has a high storage modulus at room temperature, but the storage modulus begins to drop sharply at a temperature of about 55°C. When the temperature rises to 85°C, the storage modulus drops to the point where the force value is below the detection limit. Figure 3 The polyurethane resin represented by the green line is a heat-softening resin. This resin has a low storage modulus at room temperature, but its storage modulus drops sharply when the temperature rises to about 90°C. When the temperature rises to about 110°C, the storage modulus drops to the point where the force value is below the detection limit. Figure 3 The polyurethane resin represented by the red line is a resin that cannot be softened by heat below 180°C. The storage modulus of this resin is not high at room temperature, and the decrease in storage modulus is not significant even when the temperature is raised to 180°C.

[0123] In this experimental example, the polyurethane aqueous dispersions used in the various embodiments and comparative examples were poured into a mold and dried at room temperature to obtain a polyurethane resin film. The polyurethane film was then cut into strips of 13mm × 20mm and their dynamic mechanical properties were tested according to the method in standard ASTM D4065-2020. Specifically, the cut strips were clamped in the upper and lower dynamic and static fixtures of a dynamic mechanical analyzer (DMA), and a reciprocating stretching method was used. The temperature was increased from room temperature to 180°C at a rate of 3°C / min, or stopped when the film softened to the point where the tensile force was too small to be measured. The stretching amplitude was 1%, and the frequency was 1Hz. The dynamic mechanical performance of the tested samples under these reciprocating stretching conditions was recorded, and the storage modulus was used to characterize the softening of the strips. Since the service temperature of the resin composition for bonding polyolefin materials in this invention is 130°C, the ratio of the storage modulus E'30 at 30°C to the storage modulus E'130 at 130°C was used as a benchmark to evaluate the viscoelasticity of the polyurethane resin film at 130°C.

[0124] The storage modulus test results of the thin film specimens prepared by the polyurethane aqueous dispersions used in each embodiment and comparative example are shown in Table 1.

[0125] Table 1. Examples and Comparative Examples Used

[0126] Storage modulus of thin film specimens prepared from polyurethane aqueous dispersion

[0127]

[0128] As shown in Table 1, the polyurethane resins Baybond® PU330 and Bayhydrol® UH240 exhibit viscoelasticity at 130°C and can be used to bond polyolefin materials at 130°C.

[0129] Experiment Example 2

[0130] This experimental example is used to evaluate the fusibility of the resin compositions for bonding polyolefin materials in each embodiment and comparative example. The test method is as follows: The resin compositions for bonding polyolefin materials in each embodiment and comparative example are cut into two samples with a size of 15mm × 5mm, stacked crosswise, placed between two polytetrafluoroethylene films, and then hot-pressed on a flatbed hot press preheated to 130°C for 1 minute. After cooling to room temperature, the fusibility between the two layers of resin composition after hot pressing is observed. The fusibility is scored according to the observation results, and the scoring criteria are as follows:

[0131] 4 points: The two resin layers have completely fused together to form a whole, and the edges between the two layers are not visible. The two resin layers cannot be separated.

[0132] 3 points: The two resin layers are bonded together, but an edge is still visible between them. Separating the two resin layers will damage the resin layers.

[0133] 2 points: The two resin layers are bonded together, and you can still see the edges between the two layers. When separating the two resin layers, the resin layers will not be damaged and can be separated completely, but it requires a lot of force.

[0134] 1 point: The two resin layers are only lightly bonded together, and can be separated with very little force.

[0135] 0 points: The two layers of resin composition separate naturally and do not stick together.

[0136] The fusion performance scores of the resin compositions used for bonding polyolefin materials in each embodiment and comparative example are shown in Table 2.

[0137] Table 2. Adhesives used in each embodiment and comparative example.

[0138] Melting properties score of resin compositions of polyolefin materials

[0139]

[0140] As shown in Table 2, adhesives prepared using Baybond® PU330 or Bayhydrol® UH240 polyurethane alone exhibit better fusion properties, while adhesives prepared using other polyurethanes or elastomer resins alone show poorer fusion properties. Furthermore, the resin compositions of each embodiment demonstrate good fusion properties, indicating that the resin compositions of the present invention can form a good fusion within the adhesive layer when used to bond polyolefin materials at 130°C. In addition, to obtain better fusion properties, a polyurethane resin with a storage modulus E'30 at 30°C to a storage modulus E'130 at 130°C greater than 100 is required.

[0141] Example of effect

[0142] To examine the bonding effect of the resin compositions used for bonding polyolefin materials in the various embodiments and comparative examples on polyolefin materials, the resin compositions used for bonding polyolefin materials in the various embodiments and comparative examples were used to bond polyethylene film materials and polyethylene sheets, and then the bonding force was tested.

[0143] The test method for the adhesive strength of polyethylene film materials is as follows: A 1mm thick high-density polyethylene film is cut into samples measuring 150mm × 10mm. The resin compositions for bonding polyolefin materials from each example and comparative example are placed between two cut high-density polyethylene films. Release paper is placed between the ends of the upper and lower layers of high-density polyethylene films to prevent the ends of the polyethylene films from thermally bonding together. A schematic diagram of the stacked compositions is shown below. Figure 4 As shown, the stacked composition was placed between two polytetrafluoroethylene (PTFE) films, and then hot-pressed for 1 minute on a flatbed hot press preheated to 130°C. After cooling to room temperature, a multilayer composite material was obtained. The high-density polyethylene (HDPE) film in the multilayer composite material was peeled off using a universal testing machine. The adhesion strength was scored based on the peeling results, according to the following criteria:

[0144] 4 points: The polyethylene film and resin composition cannot be peeled apart, and the polyethylene film breaks during the peeling process;

[0145] 3 points: The polyethylene film and resin composition can be completely peeled off, but the polyethylene film undergoes significant deformation during the peeling process;

[0146] 2 points: The polyethylene film and resin composition can be completely peeled off, and the polyethylene film undergoes slight deformation during the peeling process;

[0147] 1 point: The polyethylene film and resin composition can be completely peeled off without deformation of the polyethylene film;

[0148] 0 points: The polyethylene film and resin composition are not bonded together and separate automatically without force.

[0149] The test method for the adhesion of polyethylene sheets is as follows: The resin compositions for bonding polyolefin materials in each example and comparative example are placed between two high-density polyethylene sheets of the same thickness, and then placed on a flatbed hot press preheated to 130°C for 10 minutes. After cooling to room temperature, the T-peel strength is tested using a universal testing machine according to the method in standard GB / T 2791-1995, and the tensile shear strength is tested according to the method in standard GB / T 7124-2008.

[0150] The bonding properties of the resin compositions for bonding polyolefin materials in each embodiment and comparative example to polyethylene films and polyethylene sheets are shown in Table 3.

[0151] Table 3. Examples and comparative examples of bonding polyolefins

[0152] The adhesive properties of the resin composition of the material to polyethylene film and polyethylene sheet

[0153]

[0154] Note: "-" indicates that it has not been tested.

[0155] As shown in Table 3, the resin composition of the present invention has good adhesion to both polyethylene film and polyethylene sheet. The adhesion to polyethylene film is basically greater than the strength of polyethylene film, and the peel strength to polyethylene sheet is greater than 1.4 kN / m and the shear strength is greater than 1.6 MPa.

[0156] Comparative Examples 1, 3, and 7 show that polyurethane resin alone exhibits weak adhesion to polyethylene. Comparative Examples 2, 5-6, 8, and 10-11 show that while butadiene-styrene copolymer alone shows some adhesion to polyethylene film, its T-peel strength and shear strength are low, failing to meet the requirements for high-strength adhesion. Examples 1, 4, and 6-7 show that using both polyurethane resin and butadiene-styrene copolymer simultaneously significantly improves the adhesion strength to polyethylene, indicating a synergistic effect between the two. Comparative Example 9 shows that a low butadiene content in the butadiene-styrene copolymer results in poor adhesion to the polyethylene substrate, indicating that butadiene content significantly affects adhesion performance. To obtain better adhesion performance, the butadiene content in the butadiene-styrene copolymer needs to be greater than 60%.

[0157] As can be seen from Examples 1-3, the mass ratio of polyurethane resin and butadiene-styrene-vinylpyridine copolymer in the resin composition also has a certain influence on the adhesion force, but the influence is not significant. Moreover, as the mass ratio of the two increases, the adhesion force to polyethylene shows a trend of first increasing and then decreasing.

[0158] As shown in Comparative Examples 4-6 and 10, when the butadiene-styrene copolymer is kept constant, the adhesion of the resin composition to polyethylene decreases when the type of polyurethane resin is changed. This indicates that the type of polyurethane also has a significant impact on the adhesion performance. Only polyurethane resins with a storage modulus E'30 at 30°C and a storage modulus E'130 at 130°C greater than 100 can impart better adhesion performance to the composition.

[0159] As can be seen from Examples 1-8 and Comparative Examples 1-11, only when polyurethane resin with a storage modulus E'30 at 30°C and a storage modulus E'130 at 130°C greater than 100 is used in combination with an appropriate amount of butadiene-styrene copolymer or butadiene-styrene-vinylpyridine copolymer with a butadiene content greater than 60% can polyethylene be effectively bonded.

[0160] Furthermore, as demonstrated in Examples 8-9 and Comparative Examples 12-18, acrylates prepared by polymerizing allylsilane-modified pyridine monomers, allylsilane-modified carbazole monomers, and lauryl acrylate can also achieve good adhesion to polyethylene when used in combination with polyurethane resins. The pyridine, tert-butyl, carbazole, and silicon atoms in the allylsilane-modified pyridine and carbazole monomers, as well as the dodecyl group in lauryl acrylate, impart good toughness and strength to the acrylate. The polar pyridine and carbazole groups, the non-polar silicon atoms, the tert-butyl groups, and the dodecyl group impart good surface activity to the acrylate, enhancing its affinity and attraction to polyolefin substrates. The pyridine, carbazole, and tert-butyl groups further enhance the adhesive strength to polyolefin substrates through steric hindrance, physical entanglement, and chemical action.

[0161] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the concept and technical solution of the present invention to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A resin composition for bonding polyolefin materials, characterized in that, Composed of polyurethane resin and elastomer resin; the ratio of the storage modulus of the polyurethane resin at 30°C to its storage modulus at 130°C is ≥100; the elastomer resin is a butadiene-styrene-vinylpyridine copolymer, a butadiene-styrene copolymer, or an acrylate polymer; the butadiene content in the butadiene-styrene-vinylpyridine copolymer or the butadiene-styrene copolymer is not less than 60%; the acrylate polymer is prepared by polymerization of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, and lauryl acrylate, and the structure of the allylsilane-modified pyridine monomer is as follows: ； The structure of the allylsilane-modified carbazole monomer is as follows: 。 2. The resin composition for bonding polyolefin materials according to claim 1, characterized in that, The mass ratio of the polyurethane resin to the elastomer resin is 24~75:25~76.

3. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The butadiene-styrene-vinylpyridine copolymer contains 65-70% butadiene.

4. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The butadiene-styrene copolymer contains 65-85% butadiene.

5. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The mass ratio of the allylsilane-modified pyridine monomer, the allylsilane-modified carbazole monomer, and the lauryl acrylate is 2~3:1~2:3.5~5.

6. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The polymerization reaction uses ammonium persulfate as the initiator, and the mass of ammonium persulfate is 1.5-3% of the sum of the masses of allylsilane-modified pyridine monomer, allylsilane-modified carbazole monomer, and lauryl acrylate; the polymerization reaction is carried out at a temperature of 80-85°C for 5-8 hours.

7. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The polymerization reaction is carried out in a solvent consisting of water and ethanol, and an emulsifier, sodium dodecyl sulfate, is also added during the polymerization reaction.

8. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The allylsilane-modified pyridine monomer is prepared by reacting 4-tert-butylaminopyridine with n-butyllithium and then with allyl dimethylchlorosilane, wherein the molar ratio of 4-tert-butylaminopyridine, n-butyllithium and allyl dimethylchlorosilane is 1:1:1.1~1.

2.

9. The resin composition for bonding polyolefin materials according to claim 1 or 2, characterized in that, The allylsilane-modified carbazole monomer is prepared by reacting 3,6-di-tert-butylcarbazole with n-butyllithium and then with allyl dimethylchlorosilane, wherein the molar ratio of 3,6-di-tert-butylcarbazole, n-butyllithium and allyl dimethylchlorosilane is 1:1:1.1~1.

2.

10. A method for preparing a resin composition for bonding polyolefin materials as described in any one of claims 1-9, comprising the following steps: A polyurethane aqueous dispersion and an elastomer resin emulsion are mixed and then dried and molded to obtain a resin composition for bonding polyolefin materials.

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