Polyolefin hot melt adhesive for hot-pressed film, preparation method of polyolefin hot melt adhesive and high-shear side plate insulation hot-pressed film

Abstract

The invention discloses a polyolefin hot melt adhesive for a rapid hot-pressing film, a preparation method of the polyolefin hot melt adhesive and a high-shear PET (Polyethylene Terephthalate) insulating hot-pressing film. The polyolefin hot melt adhesive is prepared from the following raw material components in parts by weight: 50 to 100 parts of matrix resin, 5 to 20 parts of tackifying resin, 2 to 10 parts of thermoplastic reinforced resin, 22 to 40 parts of a flame retardant, 0.05 to 0.25 part of a cross-linking agent, 0.1 to 0.5 part of an auxiliary cross-linking agent, 0.1 to 0.4 part of a main antioxidant and 0.1 to 0.4 part of an auxiliary antioxidant. The polyolefin hot melt adhesive provided by the invention has relatively high adhesion and cohesive strength with an aluminum side plate at normal temperature, low temperature (-40 DEG C) and high temperature (60 DEG C), can be used for a long time in an environment of-40 DEG C to 130 DEG C, and is high in insulation safety. The polyolefin hot melt adhesive has few unsaturated double bonds after cross-linking, has better thermal aging performance compared with a traditional hot melt adhesive, does not need a solvent in the preparation process, and is more environment-friendly.

Description

Technical Field

[0001] The invention relates to the field of hot melt adhesive and hot pressing film materials, and in particular to a polyolefin hot melt adhesive for hot pressing film, a preparation method thereof and a high shear side plate insulating hot pressing film. Background Art

[0002] In recent years, with the continuous advancement of lithium battery technology, new energy vehicles have ushered in explosive development, and at the same time, the performance and safety requirements of new energy vehicles are getting higher and higher. Most of the safety issues of new energy vehicles are reflected in the safety of lithium batteries. A battery pack contains multiple battery modules, and the battery module is composed of a series of components such as multiple battery cells, bottom plates, side plates, end plates (including end plate insulation), circuit board busbars, and cover plates. Insulation failure in any part during use may cause a short circuit failure of the monomer in the module. If the above situation occurs, it may cause the battery temperature to rise rapidly, causing a fire or explosion. Among them, the insulation between the aluminum plate and the battery cell is very important. The traditional side plate insulation is completed by spraying epoxy powder coating on the aluminum plate. Because air will be brought in during the spraying, some of them have small pinholes, which will cause the risk of leakage.

[0003] New side panel insulation protection with adhesive insulation film pressed together. CN 111073543, a power lithium battery side panel insulation film and a power lithium battery module, mentions a new energy side panel insulation film with thermosetting polyester glue, which can withstand high and low temperatures, humidity and heat, and has excellent flame retardancy. It is a product that meets the performance requirements, but because isocyanate requires a long curing time, its curing time is as long as 20 minutes, and due to heat transfer efficiency problems, only 20 pieces can be produced at a time, which also limits its production efficiency. There is shaking when the car is running, and if there is shaking in the summer when it is heated by long-term charging and discharging, it may cause problems such as slippage and detachment between the side panel film and the side panel, causing insulation safety problems. Develop a fast hot-pressed insulating flame-retardant side panel film that has high shear strength at room temperature and high temperature, and is resistant to high and low temperatures, humidity and heat to meet the weather resistance and safety requirements of the side panel insulation.

[0004] Therefore, it is necessary to improve the existing technology to provide a more reliable solution. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a polyolefin hot melt adhesive for hot pressing film, a preparation method thereof and a high shear side plate insulation hot pressing film in view of the deficiencies in the above-mentioned prior art.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: the first aspect of the present invention provides a polyolefin hot melt adhesive for hot pressing film, comprising the following raw material components in parts by weight: 50-100 parts of main resin, 5-20 parts of tackifying resin, 2-10 parts of thermoplastic reinforcing resin, 22-40 parts of flame retardant, 0.05-0.25 parts of cross-linking agent, 0.1-0.5 of auxiliary cross-linking agent, 0.1-0.4 parts of primary antioxidant and 0.1-0.4 parts of auxiliary antioxidant.

[0007] Preferably, the main resin is one or more of modified POE (modified polyolefin elastomer), modified ethylene-vinyl acetate EVA copolymer, maleic anhydride modified polypropylene, and ethylene-acrylate-glycidyl methacrylate.

[0008] Preferably, the modified POE is maleic anhydride modified POE, and the modified ethylene-vinyl acetate EVA copolymer is maleic anhydride modified ethylene-vinyl acetate EVA copolymer.

[0009] Preferably, the tackifying resin is one or more of rosin-modified phenolic resin, hydrogenated C5 petroleum resin, DCPD petroleum resin, terpene resin and modified terpene phenolic resin.

[0010] Preferably, the thermoplastic reinforced resin is one or more of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and random copolymer polypropylene.

[0011] Preferably, the flame retardant is one or more of diethyl aluminum hypophosphite, bisphenol A-bis(diphenyl phosphate), melamine cyanurate, aluminum hydroxide, and magnesium hydroxide;

[0012] The primary antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)1,3,5-triazine-2,4,6(1H,3H,5H)-trione;

[0013] The auxiliary antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol bisdiphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, tris(nonylphenol)phosphite, didodecanol thiodipropionate, and didecadecanol thiodipropionate.

[0014] Preferably, the crosslinking agent is one or more of 2,4-di-tert-butyl peroxide isopropylbenzene BIBP, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane TMCH, benzoyl peroxide (BPO), diisopropylbenzene peroxide (DCP), tert-amyl peroxyacetate (TAPA), tert-butyl peroxy-2-ethylhexyl carbonate (TBEC) and tert-butyl peroxy-3,5,5-trimethylhexanoate (TBPMH);

[0015] The auxiliary crosslinking agent is one or more of trimethylolpropane triacrylate (TMPTA), triallyl isocyanurate (TAIC), propoxylated glycerol triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, and evolved trimethylolpropane triacrylate.

[0016] Preferably, the main resin is one or both of maleic anhydride modified POE and modified ethylene-vinyl acetate EVA copolymer;

[0017] The tackifying resin is rosin-modified phenolic resin;

[0018] The thermoplastic reinforced resin is one or two of low-density polyethylene LDPE and linear low-density LLDPE polyethylene;

[0019] The flame retardant is a mixture of diethyl aluminum hypophosphite and melamine cyanurate;

[0020] The primary antioxidant is one or two of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione;

[0021] The auxiliary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite;

[0022] The cross-linking agent is one or two of 2,4-di-tert-butyl cumyl peroxide, dicumyl peroxide, and 2,4-di-tert-butyl cumyl peroxide;

[0023] The auxiliary cross-linking agent is propoxylated glycerol triacrylate.

[0024] A second aspect of the present invention provides a method for preparing the polyolefin hot melt adhesive for hot pressing film as described above, characterized in that it comprises the following steps:

[0025] The main resin, tackifying resin, thermoplastic reinforcing resin, flame retardant, crosslinking agent, primary antioxidant and auxiliary antioxidant are uniformly mixed, melt-extruded at 120-150° C. under nitrogen protection to obtain the polyolefin hot melt adhesive for hot pressing film.

[0026] The third aspect of the present invention provides a high shear side panel insulation hot pressing film, which is prepared by the following method: the hot pressing film as described above is coated on the surface of a PET film with a thickness of 50-100 μm by a lamination coating method with a polyolefin hot melt adhesive, the thickness of the adhesive layer is controlled to be 20-50 μm, and then a release film is attached to the adhesive surface to obtain the high shear side panel insulation hot pressing film.

[0027] The beneficial effects of the present invention are:

[0028] The present invention provides a polyolefin hot melt adhesive for hot pressing film, a preparation method thereof, and a high shear poly-side plate insulating hot pressing film based on the hot melt adhesive; the polyolefin hot melt adhesive provided by the present invention has high adhesion and cohesive strength with an aluminum water-cooled plate at room temperature, low temperature (-40°C), and high temperature (60°C), can be used for a long time in an environment of -40°C to 80°C, and has high insulation safety;

[0029] The polyolefin hot melt adhesive of the present invention has fewer unsaturated double bonds after cross-linking, and has better thermal aging performance than traditional hot melt adhesives. In addition, the preparation process thereof does not require solvents and is more environmentally friendly.

[0030] The high shear poly side panel insulation hot pressing film prepared by the present invention has high processing efficiency and can be hot pressed and bonded at 120-180° C. The hot pressing time can be completed in 20-60 seconds, which is faster than the side panel hot pressing film processing on the market. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0032] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0033] The test methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified. In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0034] The invention provides a polyolefin hot melt adhesive for hot pressing film, comprising the following raw material components in parts by weight: 50-100 parts of a main resin, 5-20 parts of a tackifying resin, 2-6 parts of a thermoplastic reinforcing resin, 22-40 parts of a flame retardant, 0.05-0.25 parts of a cross-linking agent, 0.1-0.5 parts of an auxiliary cross-linking agent, 0.1-0.4 parts of a primary antioxidant, and 0.1-0.4 parts of an auxiliary antioxidant.

[0035] In a preferred embodiment, the main resin is one or more of modified POE, modified ethylene-vinyl acetate EVA copolymer, maleic anhydride modified polypropylene, and ethylene-acrylate-methacrylate glycerol. Among them, the modified POE is maleic anhydride modified POE, and the modified ethylene-vinyl acetate EVA copolymer is maleic anhydride modified ethylene-vinyl acetate EVA copolymer.

[0036] More preferably, the main resin is maleic anhydride modified POE, wherein the maleic anhydride content is 0.8-3%, the melting point is 70-95°C, and the melting index at 190°C is 0.8-25g / 10min. Polyolefin elastomers have relatively high cohesive strength, and a small amount of polar groups can better bond the aluminum base and the PET substrate.

[0037] In a preferred embodiment, the tackifying resin is one or more of rosin-modified phenolic resin, hydrogenated C5 petroleum resin, DCPD petroleum resin, terpene resin and modified terpene phenolic resin, which is used to increase the adhesion of the hot melt adhesive to the substrate. More preferably, the tackifying resin is rosin-modified phenolic resin.

[0038] In a preferred embodiment, the thermoplastic reinforced resin is one or more of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and random copolymer polypropylene. More preferably, the thermoplastic reinforced resin is a mixture of low-density polyethylene LDPE and linear low-density polyethylene, and the density of the low-density polyethylene and the linear low-density polyethylene is 0.91-0.92 g / cm3, and the melt index at 190°C is 0.5-15 g / 10min.

[0039] In a preferred embodiment, the flame retardant is one or more of diethyl aluminum hypophosphite, bisphenol A-bis(diphenyl phosphate), melamine cyanurate, aluminum hydroxide, and magnesium hydroxide; more preferably, the flame retardant is a compound of diethyl aluminum hypophosphite and melamine cyanurate, diethyl aluminum hypophosphite: melamine cyanurate = 8:1 to 3:1, and the particle size is 2-8 μm.

[0040] In a preferred embodiment, the primary antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)1,3,5-triazine-2,4,6(1H,3H,5H)-trione; more preferably, the primary antioxidant is one or two of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

[0041] In a preferred embodiment, the secondary antioxidant is one or more of tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol bis diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate, tris(nonylphenol) phosphite, didodecanol thiodipropionate, and distearyl thiodipropionate. More preferably, the secondary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite.

[0042] In a preferred embodiment, the crosslinking agent is one or more of 2,4-di-tert-butyl peroxide isopropylbenzene (BIBP), 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane TMCH, benzoyl peroxide (BPO), diisopropylbenzene peroxide (DCP), tert-amyl peroxy acetate (TAPA), tert-butyl peroxy-2-ethylhexyl carbonate (TBEC) and tert-butyl peroxy-3,5,5-trimethylhexanoate (TBPMH); more preferably, the crosslinking agent is 2,4-di-tert-butyl peroxide isopropylbenzene (BIBP).

[0043] In a preferred embodiment, the auxiliary crosslinking agent is one or more of trimethylolpropane triacrylate (TMPTA), triallyl isocyanurate (TAIC), propoxylated glycerol triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, and ethoxylated trimethylolpropane triacrylate. More preferably, (3) one or two of propoxylated glycerol triacrylate and triallyl isocyanurate (TAIC).

[0044] In a preferred embodiment, the main resin is one or both of maleic anhydride modified POE and modified ethylene-vinyl acetate EVA copolymer;

[0045] The tackifying resin is rosin-modified phenolic resin;

[0046] The thermoplastic reinforcing resin is one or two of low-density polyethylene LDPE and linear low-density LLDPE polyethylene;

[0047] The flame retardant is a mixture of diethylaluminum hypophosphite and melamine cyanurate;

[0048] The main antioxidant is one or two of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione;

[0049] The auxiliary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite;

[0050] The cross-linking agent is one or two of 1,3-1,4-di(tert-butyl peroxyisopropylbenzene)benzene, diisopropylbenzene peroxide, and 2,4-di-tert-butyl peroxyisopropylbenzene;

[0051] The auxiliary crosslinking agent is propoxylated glycerol triacrylate.

[0052] The present invention also provides a method for preparing the polyolefin hot melt adhesive for hot pressing film as above, comprising the following steps:

[0053] The main resin, tackifying resin, thermoplastic reinforcing resin, flame retardant, crosslinking agent, primary antioxidant and auxiliary antioxidant are uniformly mixed, melt-extruded at 120-150° C. under nitrogen protection to obtain a polyolefin hot melt adhesive for hot pressing film.

[0054] The present invention also provides a high shear side panel insulation hot pressing film, which is prepared by the following method: the above hot pressing film is coated on the surface of a PET film with a thickness of 50-100 μm by a lamination coating method using a polyolefin hot melt adhesive, the thickness of the adhesive layer is controlled to be 20-50 μm, and then a release film is attached to the adhesive surface to obtain a high shear side panel insulation hot pressing film.

[0055] The present invention uses modified polyolefin elastomer (POE) as the main resin. The polyolefin elastomer has a very narrow molecular weight distribution and a short branched chain structure, and thus has excellent physical and mechanical properties such as high elasticity, high strength, high elongation, and excellent high and low temperature resistance.

[0056] The present invention can adjust the cohesive strength of the hot melt adhesive by adding high melting point and high strength polyolefins such as low density polyethylene and linear low density polyethylene into the formula, thereby improving the shear performance and peeling performance between the water cooling plate and the hot pressing film. The addition of polypropylene can also reduce the water absorption of the material and increase the moisture and heat resistance and high temperature bonding performance of the hot melt adhesive.

[0057] The invention partially crosslinks polyolefin by controlling the addition amount of the crosslinking agent and the auxiliary crosslinking agent, thereby improving the thermal aging, mechanical strength and other properties of maleic anhydride modified POE; and the high polarity group in the auxiliary crosslinking agent can increase the adhesion to the metal and increase the shearing, pulling and other bonding properties of the hot pressing film.

[0058] The present invention adds a specific proportion of nitrogen-phosphorus flame retardant in combination with other flame retardants, and the synergistic flame retardant effect produced can make the water-cooled plate insulation film reach the UL-94VTM-0 flame retardant grade; the strong dehydration effect produced by the phosphorus-containing compound when decomposed by heat causes the covered polymer surface to be carbonized to form a carbon film, and this carbon film can play the role of heat insulation and oxygen isolation, effectively preventing the further spread of the surface flame, and achieving the flame retardant effect.

[0059] The above is the overall concept of the present invention, and detailed embodiments and comparative examples are provided below on the basis of the overall concept of the present invention to further illustrate the present invention.

[0060] Example 1

[0061] A high shear side plate insulation hot pressing film is prepared by the following method:

[0062] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 15 parts of rosin modified phenolic resin (PR-12603, Japan Sumitomo) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 18 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.1 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate (SR9092NS) are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0063] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0064] Example 2

[0065] A high shear side plate insulation hot pressing film is prepared by the following method:

[0066] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 15 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 10 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 27 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 9 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.1 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0067] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0068] Example 3

[0069] A high shear side plate insulation hot pressing film is prepared by the following method:

[0070] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 15 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 30 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.1 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0071] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0072] Example 4

[0073] A high shear side plate insulation hot pressing film is prepared by the following method:

[0074] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 10 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 30 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.2 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0075] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0076] Example 5

[0077] A high shear side plate insulation hot pressing film is prepared by the following method:

[0078] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 10 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 30 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.05 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0079] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0080] Comparative Example 1

[0081] A high shear side plate insulation hot pressing film is prepared by the following method:

[0082] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 30 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 30 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.1 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0083] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0084] Comparative Example 2

[0085] A high shear side plate insulation hot pressing film is prepared by the following method:

[0086] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 15 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 15 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 30 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.1 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0087] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0088] Comparative Example 3

[0089] A high shear side plate insulation hot pressing film is prepared by the following method:

[0090] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 15 parts of rosin modified phenolic resin (PR-12603, Japan Sumitomo) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 15 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 3 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.1 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0091] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0092] Comparative Example 4

[0093] A high shear side plate insulation hot pressing film is prepared by the following method:

[0094] By weight, 75 parts of maleic anhydride modified POE ExxonMobil EXXELOR VA1803 Dongguan Kadar Plastic Raw Materials Co., Ltd.), 15 parts of rosin modified phenolic resin (PR-12603, Sumitomo, Japan) resin, 6 parts of LLDPE polyethylene thermoplastic reinforced resin (Dow Chemical 41E687), 30 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 6 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.2 parts of primary antioxidant 1010 pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 0.8 parts of crosslinking agent BIBP (manufacturer Changshu Arkema), 0.4 parts of (3) propoxylated propylene glycol triacrylate SR9092NS are mixed at room temperature to obtain an adhesive mixture; then the adhesive mixture is extruded through a single screw extruder in a nitrogen environment at 125°C to obtain a polyolefin hot melt adhesive for heat pressing film;

[0095] The hot melt adhesive was coated on the surface of black PET with a thickness of 100 μm by laminating to form an adhesive layer with a thickness of 30 μm. The adhesive surface was attached with a release film to obtain a high shear side panel insulation hot pressing film.

[0096] The following performance tests were performed on the insulating thermal films prepared in the above Examples 1-5 and Comparative Examples 1-4.

[0097] 1. Peeling force test of 5 aluminum plates

[0098] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0099] (2) Cut the tape into 25.4mm*300mm pieces, 5 pieces in total;

[0100] (3) Peel off the release layer of the tape, stick the adhesive surface to the aluminum plate with a rubber roller, and heat press the polyimide tape film to the surface of the aluminum plate at a temperature of 120-180°C within 20-60 seconds.

[0101] (4) After curing, measure according to GB / T 2792-1998 standard, requirement: >3000gf / inch

[0102] 3. Shear test on 5 aluminum plates

[0103] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0104] (2) Cut the tape into 25.4mm*12.5mm pieces, 5 pieces in total;

[0105] (3) Peel off the release layer of the tape, and use a rubber roller to stick the adhesive surface to the aluminum plate. Press the polyimide tape film onto the surface of the aluminum plate at 120-180°C for 20-60 seconds.

[0106] (4) After curing, measure according to GB / T 7124-2008 standard, peel at a speed of 4mm / min, record the software reading, and the requirement is >7mpa;

[0107] 4. Pull-out test on 5 aluminum plates

[0108] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0109] (2) Cut the tape into 25.4mm*25.4mm pieces, 5 pieces in total;

[0110] (3) Peel off the release layer of the tape, and use a rubber roller to stick the adhesive surface to the aluminum plate. Heat press the polyimide tape film to the surface of the aluminum plate at a temperature of 120-180°C for 20-60 seconds.

[0111] (4) After curing, measure according to GB / T 7124-2008 standard, peel at a speed of 4mm / min, record the software reading, and the requirement is >7mpa;

[0112] 5. Shear and pull test of 5 aluminum plates at 60℃

[0113] According to the test process of test items 2, 3, and 4, the test sample is placed in a 60℃ environment for 30 minutes before the test, and then tested in a 60℃ environment, and the software readings are recorded. Shear and pull are required to be greater than 3mpa;

[0114] 6. Shear and pull test of 5 aluminum plates at -40℃;

[0115] According to the test process of test items 2, 3, and 4, the test sample is placed in a -40℃ environment for 30 minutes before the test, and then tested in a -40℃ environment, and the software readings are recorded. Shear and pull are required to be greater than 7mpa;

[0116] 7. UL 94VTM-0, VTM-1, VTM-2 vertical combustion test

[0117] Test method: Conduct flame retardancy test on μm130 PET polyolefin hot melt adhesive film according to UL-94 test standard. The flame retardancy level is required to be better than VTM-1.

[0118] 8. Aging test

[0119] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0120] (2) Peel off the release layer of the tape, and use a rubber roller to stick the adhesive surface to the aluminum plate. Press the polyimide tape film onto the aluminum plate surface at 120-180°C for 20-40 seconds.

[0121] (3) Place the sample in a test box at a temperature of 85°C and a humidity of 85% for 1000 hours, perform a shear test on 5 aluminum plates according to the second test item, and test the aged sample.

[0122] The test results are shown in Table 1 below:

[0123] Table 1

[0124]

[0125] According to the test results in Table 1, it can be seen that the high shear polyimide water-cooled plate insulating thermal film prepared in Examples 1-5 has excellent comprehensive performance, has high adhesion and cohesive strength with the aluminum water-cooled plate at room temperature, low temperature (-40°C), and high temperature (60°C), can be used for a long time in an environment of -40-130°C, and has high insulation safety.

[0126] Comparison of Example 3 with Comparative Example 1 shows that excessive tackifying resin leads to a decrease in colloid TG, and a decrease in high-temperature shear and drawing at 60°C.

[0127] Comparison between Example 3 and Comparative Example 2 shows that too much LLDPE reduces the adhesive peeling force, shearing, pulling and other properties. The main reason is that LLDPE is a relatively hard material. Adding LLDPE will reduce flexibility and room temperature adhesion. Adding too much LLDPE will reduce the bonding performance of hot melt adhesive to metal.

[0128] From the comparison between Example 3 and Comparative Example 3, it can be seen that if the amount of flame retardant added is too low, the flame retardant performance will not reach VTM-1.

[0129] By comparing Example 2 with Comparative Example 4, it can be seen that adding too much cross-linking agent will cause the hot melt adhesive to cross-link prematurely and the degree of cross-linking is too large, which will cause the adhesive to burn easily during hot pressing and fail to melt and bond to the aluminum plate.

[0130] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A polyolefin hot melt adhesive for hot pressing film, characterized in that: The invention comprises the following raw material components in parts by weight: 50-100 parts of main resin, 5-20 parts of tackifying resin, 2-10 parts of thermoplastic reinforcing resin, 22-40 parts of flame retardant, 0.05-0.25 parts of crosslinking agent, 0.1-0.5 parts of auxiliary crosslinking agent, 0.1-0.4 parts of main antioxidant and 0.1-0.4 parts of auxiliary antioxidant.

2. The polyolefin hot melt adhesive for hot pressing film according to claim 1, characterized in that: The main resin is one or more of modified POE, modified ethylene-vinyl acetate EVA copolymer, maleic anhydride modified polypropylene, and ethylene-acrylate-glycidyl methacrylate.

3. The polyolefin hot melt adhesive for hot pressing film according to claim 2, characterized in that: in, The modified POE is maleic anhydride modified POE, and the modified ethylene-vinyl acetate EVA copolymer is maleic anhydride modified ethylene-vinyl acetate EVA copolymer.

4. The polyolefin hot melt adhesive for hot pressing film according to claim 1, characterized in that: The tackifying resin is one or more of rosin-modified phenolic resin, hydrogenated C5 petroleum resin, DCPD petroleum resin, terpene resin and modified terpene phenolic resin.

5. The polyolefin hot melt adhesive for hot pressing film according to claim 1, characterized in that: The thermoplastic reinforced resin is one or more of low-density polyethylene, linear low-density polyethylene, and random copolymer polypropylene.

6. The polyolefin hot melt adhesive for hot pressing film according to claim 1, characterized in that: The flame retardant is one or more of diethyl aluminum hypophosphite, bisphenol A-bis(diphenyl phosphate), melamine cyanurate, aluminum hydroxide, and magnesium hydroxide; The primary antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)1,3,5-triazine-2,4,6(1H,3H,5H)-trione; The auxiliary antioxidant is one or more of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol bisdiphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, tris(nonylphenol)phosphite, didodecanol thiodipropionate, and didecadecanol thiodipropionate.

7. The polyolefin hot melt adhesive for hot pressing film according to claim 1, characterized in that: The cross-linking agent is one or more of 2,4-di-tert-butyl peroxide isopropylbenzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, benzoyl peroxide, diisopropylbenzene peroxide, tert-amyl peroxyacetate, tert-butyl peroxy-2-ethylhexyl carbonate and tert-butyl peroxy-3,5,5-trimethylhexanoate; The auxiliary crosslinking agent is one or more of trimethylolpropane triacrylate, triallyl isocyanurate, propoxylated glycerol triacrylate, tri(2-hydroxyethyl)isocyanuric acid triacrylate, and ethoxylated trimethylolpropane triacrylate.

8. The polyolefin hot melt adhesive for hot pressing film according to claim 1, characterized in that: The main resin is one or both of maleic anhydride modified POE and maleic anhydride modified ethylene-vinyl acetate EVA copolymer; The tackifying resin is rosin-modified phenolic resin; The thermoplastic reinforced resin is one or two of low-density polyethylene LDPE and linear low-density LLDPE polyethylene; The flame retardant is a mixture of diethyl aluminum hypophosphite and melamine cyanurate; The primary antioxidant is one or two of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione; The auxiliary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite; The cross-linking agent is one or two of 2,4-di-tert-butyl cumyl peroxide, dicumyl peroxide, and 2,4-di-tert-butyl cumyl peroxide; The auxiliary cross-linking agent is propoxylated glycerol triacrylate.

9. A method for preparing a polyolefin hot melt adhesive for hot pressing film according to any one of claims 1 to 8, characterized in that: The following steps are involved: The main resin, tackifying resin, thermoplastic reinforcing resin, flame retardant, crosslinking agent, primary antioxidant and auxiliary antioxidant are uniformly mixed, melt-extruded at 120-150° C. under nitrogen protection to obtain the polyolefin hot melt adhesive for hot pressing film.

10. A high shear side plate insulation hot pressing film, characterized in that: It is prepared by the following method: coating the polyolefin hot melt adhesive for hot pressing film as described in any one of claims 1 to 8 on the surface of a PET film with a thickness of 50-100 μm by laminating coating, controlling the thickness of the adhesive layer to be 20-50 μm, and then laminating a release film on the adhesive surface to obtain the high shear side panel insulation hot pressing film.

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