Adhesive for low-temperature hot-pressing side plate insulating film, preparation method of adhesive and low-temperature hot-pressing insulating film

Abstract

The invention discloses an adhesive for a low-temperature hot-pressing side plate insulating film, a preparation method of the adhesive and the low-temperature hot-pressing insulating film. The adhesive comprises the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of a flame retardant, 4-6 parts of a curing agent, 0.3-0.7 part of a main antioxidant, 0.2-0.4 part of an auxiliary antioxidant, 1-5 parts of an acid acceptor and 50-150 parts of a solvent. According to the present invention, the polycarbonate polyol modified polyester in the adhesive formula has good low-temperature fluidity, such that the adhesive can well permeate and adhere to the adhered surface during the low-temperature hot pressing process, and particularly can effectively improve the adhesion strength when the insulating material in the low-temperature environment is adhered; by reducing the temperature during hot pressing, the uniformity and stability during hot pressing of the rubber surface can be effectively improved, and the problem of performance reduction caused by excessive heating of the material is avoided.

Description

Technical Field

[0001] The present invention relates to the field of insulating film materials, and in particular to an adhesive for a low-temperature hot-pressed side plate insulating film, a preparation method thereof, and a low-temperature hot-pressed insulating film. Background Art

[0002] With the continuous miniaturization, lightweight and diversified functions of electronic products and electrical equipment, the industry's performance requirements for various materials are also increasing. Insulating materials, in particular, not only need to have excellent electrical insulation properties, but also must be able to meet multiple requirements such as efficient heat dissipation, good mechanical strength and heat treatment performance. With the development of technology, especially in the fields of battery technology, electronic packaging, automotive electronics, etc., hot pressing molding technology is widely used in the manufacture of high-performance insulating materials to ensure the stability and reliability of electronic equipment under high power, high frequency and complex environments.

[0003] As an important processing method, hot pressing technology shapes and solidifies materials by heating and pressurizing. In the manufacturing process of many electronic devices, especially for the production of electronic packaging and battery cells, hot pressing technology is needed to heat the thin film insulating material to a certain temperature, and the material is shaped and the physical properties are modified by combining heat and pressure. Hot pressing technology can ensure that the material's shape, thickness, density and other parameters meet the design requirements, thereby improving the reliability and safety of the overall device.

[0004] However, current hot pressing technology has certain limitations, especially when dealing with some low-temperature sensitive materials, the traditional high-temperature hot pressing process may have adverse effects on these materials. For example, some electronic components, flexible circuit boards, high-performance plastics and polymer materials have relatively low thermal stability and temperature resistance, and are prone to thermal deformation, performance degradation and even failure at high temperatures, which poses potential risks to the performance and service life of the final product.

[0005] The side panel insulation hot pressing film is an important component used in electronic devices, especially liquid crystal displays. Its main function is to provide insulation protection to prevent current leakage or damage to the circuit. The manufacturing process of the side panel insulation film usually requires hot pressing at high temperature to ensure that the film material is well bonded to the substrate and has the required insulation properties. However, in the prior art, the traditional hot pressing process often requires a higher temperature, which brings the following disadvantages:

[0006] 1. High temperature may cause material degradation: Traditional hot pressing processes usually require higher temperatures, which may cause degradation of certain materials, especially some polymer film materials, affecting their mechanical strength, insulation performance and service life. Excessive temperature may also cause the material to deform, resulting in unstable film quality.

[0007] 2. High-temperature hot pressing has high requirements for equipment and process: High-temperature hot pressing process requires production equipment to have high-temperature processing capabilities, and in actual production, temperature control is difficult to be precise, which may lead to instability in the production process. In addition, high-temperature hot pressing process may also increase production costs and energy consumption.

[0008] 3. Non-uniformity during hot pressing: The hot pressing process at high temperature may lead to uneven bonding between the membrane material and the substrate. Some areas may be over-pressed, overheated or under-pressed, affecting the quality of the final product.

[0009] 4. High requirements for the environment: Strict environmental control is required during the high-temperature hot pressing process, including the stability of temperature and humidity, which increases the complexity of the manufacturing process.

[0010] Therefore, in order to meet the increasing demand for diverse material properties in electronic devices, developing an insulating film material that can achieve good molding effects at lower temperatures has become an important research direction in the field of materials science. This new material needs to have the following advantages: low-temperature molding, excellent electrical insulation, thermal stability, and good mechanical properties. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide an adhesive for low-temperature hot-pressed side plate insulation film, a preparation method thereof and a low-temperature hot-pressed insulation film in view of the deficiencies in the above-mentioned prior art. The main purpose of the present invention is to solve the problems of excessive temperature, excessive energy consumption, unstable production process, etc. existing in the traditional high-temperature hot-pressing process, and to provide an adhesive for low-temperature hot-pressed side plate insulation film and an insulation film, thereby improving product quality, reducing costs, and improving production efficiency.

[0012] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: in the first aspect of the present invention, a low-temperature hot-pressed side panel insulating film adhesive is provided, comprising the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of flame retardant, 4-6 parts of curing agent, 0.3-0.7 parts of primary antioxidant, 0.2-0.4 parts of auxiliary antioxidant, 1-5 parts of acid absorber, and 50-150 parts of solvent.

[0013] Preferably, the modified polyester resin is one or more of polycarbonate polyol modified polyester, isophthalic acid type polyester, isophthalic acid type polyester, and polyurethane modified polyester.

[0014] Preferably, the epoxy resin is one or more of phenolic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and modified epoxy resin.

[0015] Preferably, the flame retardant is one or more of diethyl aluminum phosphite, bisphenol A-bis(diphenyl phosphate), melamine cyanurate, aluminum hydroxide, and magnesium hydroxide;

[0016] Preferably, the primary antioxidant is one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecylβ-(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.

[0017] Preferably, the auxiliary 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 auxiliary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite;

[0018] The curing agent is a blocked polyisocyanate curing agent based on hexamethylene diisocyanate;

[0019] The acid absorbing agent is a hydrotalcite-based inorganic acid absorbing agent;

[0020] The solvent is one or more of butanone and ethyl acetate.

[0021] Preferably, the modified polyester resin is a polycarbonate polyol modified polyester;

[0022] The epoxy resin is a phenolic epoxy resin or a bisphenol F epoxy resin, and the epoxy equivalent is 160-180 g / eq;

[0023] The flame retardant is a mixture of diethyl aluminum hypophosphite and melamine cyanurate, the mass ratio of diethyl aluminum hypophosphite to melamine cyanurate is 8:1 to 3:1, and the particle sizes of both are 2-8 μm;

[0024] 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;

[0025] The auxiliary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite.

[0026] A second aspect of the present invention provides a method for preparing the adhesive for low-temperature hot-pressing side plate insulation film as described above, comprising the following steps:

[0027] By weight, 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of flame retardant, 0.3-0.7 parts of primary antioxidant, 0.2-0.4 parts of secondary antioxidant, 1-5 parts of acid absorber and 20-70 parts of solvent are mixed and stirred evenly, and then 4-6 parts of curing agent and 30-80 parts of solvent are added and stirred evenly to obtain an adhesive for low-temperature hot-pressed side panel insulation film.

[0028] A third aspect of the present invention provides a low-temperature hot-pressed insulating film, which is prepared by the following method:

[0029] The low-temperature hot-pressed side plate insulating film adhesive as described above is evenly coated on the substrate, and the low-temperature hot-pressed insulating film is obtained after curing.

[0030] Preferably, the substrate is a PET film with a thickness of 75-100 μm and is pre-corona treated; the thickness of the adhesive layer formed by coating the low-temperature hot-pressed side plate insulating film with an adhesive is 30-45 μm.

[0031] The beneficial effects of the present invention are:

[0032] The present invention provides an adhesive for a low-temperature hot-pressed side panel insulating film, a preparation method thereof, and a low-temperature hot-pressed insulating film. The polycarbonate polyol-modified polyester in the adhesive formula of the present invention has good low-temperature fluidity. This is because the molecular structure of polycarbonate has a certain flexibility, especially when it is used to modify polyester, it can reduce the glass transition temperature (Tg) of polyester, so that the adhesive can maintain good fluidity and adhesion at lower temperatures; this feature enables the adhesive to better penetrate and adhere to the bonded surface during the low-temperature hot-pressing process, especially when bonding insulating materials in a low-temperature environment, it can effectively improve the bonding strength; the present invention can effectively increase the uniformity and stability of the adhesive surface during hot pressing by reducing the temperature during hot pressing, thereby avoiding the problem of performance degradation caused by excessive heating of the material. In general, the scheme of the present invention also has at least the following advantages:

[0033] 1. Reduce production temperature:

[0034] The present invention develops materials suitable for low-temperature hot pressing, reduces the temperature required in the production process, avoids material degradation and performance loss caused by excessively high temperatures, and prolongs the service life of the product.

[0035] 2. Reduce energy consumption and costs:

[0036] Low-temperature hot pressing can significantly reduce energy consumption in the production process, thereby reducing production costs; in addition, low temperatures place lower demands on equipment, which can simplify production equipment and reduce the difficulty of equipment maintenance and management.

[0037] 3. Improve the uniformity of hot pressing process:

[0038] Low temperature hot pressing helps avoid overheating or overpressure, improves the uniformity of bonding between the film material and the substrate, and ensures a more stable quality of the final product.

[0039] 4. Control requirements for improving the production environment:

[0040] The low-temperature hot pressing process has lower requirements for environmental control, reduces strict requirements for temperature, humidity, etc., helps to simplify the production process and improve production efficiency.

[0041] 5. Provide higher reliability and security:

[0042] Low temperature processing can reduce the safety hazards caused by high temperature processing, especially in the manufacture of certain sensitive materials or components, low temperature processing may be safer and more reliable. DETAILED DESCRIPTION

[0043] 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.

[0044] 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.

[0045] 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.

[0046] The present invention provides an adhesive for low-temperature hot-pressed side plate insulating film, comprising the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of flame retardant, 4-6 parts of curing agent, 0.3-0.7 parts of primary antioxidant, 0.2-0.4 parts of auxiliary antioxidant, 1-5 parts of acid absorbent and 50-150 parts of solvent.

[0047] In a preferred embodiment, the modified polyester resin is one or more of polycarbonate polyol modified polyester, isophthalic acid type polyester, isophthalic polyester, polyurethane modified polyester. More preferably, the modified polyester resin is polycarbonate polyol modified polyester, which is a solvent-based polyester modified by polycarbonate polyol with a low glass transition temperature (Tg). This product is suitable for adhesives that exhibit excellent flexibility and adhesion to various substrates. Compared with traditional low Tg polyesters, the most important feature is that it has extremely high hydrolysis resistance under high temperature and high humidity.

[0048] In a preferred embodiment, the epoxy resin is one or more of novolac epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and modified epoxy resin. More preferably, the epoxy resin is bisphenol F epoxy resin with an epoxy equivalent of 160-180 g / eq, which has low viscosity and low molecular weight, good fluidity, and high stability.

[0049] 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 mixture of diethyl aluminum hypophosphite and melamine cyanurate, the mass ratio of diethyl aluminum hypophosphite: melamine cyanurate = 8:1 to 3:1, and the particle size of both is 2-8 μm;

[0050] 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. More preferably, the primary antioxidant is one or both of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

[0051] 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; more preferably, the secondary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite.

[0052] In a preferred embodiment, the curing agent is a blocked polyisocyanate curing agent based on hexamethylene diisocyanate.

[0053] In a preferred embodiment, the acid scavenger is a hydrotalcite-based inorganic acid scavenger.

[0054] In a preferred embodiment, the solvent is one or more of butanone and ethyl acetate.

[0055] The present invention also provides a method for preparing the adhesive for low-temperature hot-pressing side plate insulation film as above, comprising the following steps:

[0056] By weight, 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of flame retardant, 0.3-0.7 parts of primary antioxidant, 0.2-0.4 parts of secondary antioxidant, 1-5 parts of acid absorber and 20-70 parts of solvent are mixed and stirred evenly, and then 4-6 parts of curing agent and 30-80 parts of solvent are added and stirred evenly to obtain an adhesive for low-temperature hot-pressed side panel insulation film.

[0057] The present invention also provides a low-temperature hot-pressed insulating film, which is prepared by the following method:

[0058] The low-temperature hot-pressed side plate insulating film adhesive as above is evenly coated on the substrate, and the low-temperature hot-pressed insulating film is obtained after curing.

[0059] In a preferred embodiment, the substrate is a PET film with a thickness of 75-100 μm and is pre-corona treated; the thickness of the adhesive layer formed by coating the low-temperature hot-pressed side plate insulating film with an adhesive is 30-45 μm.

[0060] The present invention uses solvent-based polyester modified with polycarbonate polyol as the main resin, and the carbonate group (-OC(=O)-O-) in its chemical structure enables it to have strong chemical stability and high temperature resistance. After the polycarbonate polyol is introduced into the polyester molecule, the overall structure of the polyester can be significantly changed. This chemical structure can improve the heat resistance of the polyester material, make it have better thermal stability under high temperature or rapid temperature changes, and reduce decomposition or aging caused by overheating. The carbonate group (-OC(=O)-O-) contained in the polycarbonate molecule is a polar group. This polarity can enhance the tolerance of polyester to other polar substances, especially when it is chemically corroded or in contact with solvents.

[0061] The present invention adds bisphenol F epoxy to the formula, and the aromatic rings and oxygen atoms are arranged alternately, so that the epoxy groups formed have strong reactivity. The addition of bisphenol F epoxy can improve the thermal stability, hardness and chemical corrosion resistance of the low-temperature hot-pressed side plate film. The high cross-linking ability of the epoxy group helps to enhance the mechanical strength and heat resistance of the film, especially under low temperature conditions, and its low glass transition temperature (Tg) and good fluidity help to form a more uniform structure during the hot pressing process, effectively improving the molding quality of the film.

[0062] 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 side 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.

[0063] 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.

[0064] Example 1

[0065] A low-temperature hot-pressed side plate insulating film is prepared by the following method:

[0066] S1: By weight, 40 parts of polycarbonate polyol modified solvent-based polyester (ES-380, Guangzhou Haoyi New Materials Technology Co., Ltd.), 40 parts of bisphenol F epoxy resin (NPEL-170, Nan Ya Plastics Industry Co., Ltd.), 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.), 0.3 parts of primary antioxidant 1010 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 3 parts of acid absorber (Hycite713, Clariant Chemical), 50 parts of solvent were mixed and stirred to obtain an emulsified dispersion and then 4 parts of curing agent (Hafotex HF-3180, Guangzhou Innova Chemical Co., Ltd.) and 60 parts of solvent (butanone) were mixed evenly to obtain an adhesive for low-temperature hot-pressing side plate insulation film.

[0067] S2: preparing low-temperature hot-pressed side panel insulating film: pre-corona-treating a 100 μm PET film, and applying the adhesive in step S1 to the corona surface of the PET film, drying it to obtain a 30 μm adhesive layer to prepare a low-temperature hot-pressed side panel insulating film.

[0068] Example 2

[0069] A low-temperature hot-pressed side plate insulating film is prepared by the following method:

[0070] S1: By weight, 60 parts of polycarbonate polyol modified solvent-based polyester (ES-380, Guangzhou Haoyi New Materials Technology Co., Ltd.), 40 parts of bisphenol F epoxy resin (NPEL-170, Nan Ya Plastics Industry Co., Ltd.), 15 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 8 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.5 parts of primary antioxidant 1010 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 3 parts of acid absorber (Hycite713, Clariant Chemical), 50 parts of solvent were mixed and stirred to obtain an emulsified dispersion and then 4 parts of curing agent (Hafotex HF-3180, Guangzhou Innova Chemical Co., Ltd.) and 60 parts of solvent (butanone) were mixed evenly to obtain an adhesive for low-temperature hot-pressing side plate insulation film.

[0071] S2: preparing low-temperature hot-pressed side panel insulating film: pre-corona-treating a 100 μm PET film, and applying the adhesive in step S1 to the corona surface of the PET film, drying it to obtain a 40 μm adhesive layer to prepare a low-temperature hot-pressed side panel insulating film.

[0072] Example 3

[0073] A low-temperature hot-pressed side plate insulating film is prepared by the following method:

[0074] S1: By weight, 60 parts of polycarbonate polyol modified solvent-based polyester (ES-380, Guangzhou Haoyi New Materials Technology Co., Ltd.), 50 parts of bisphenol F epoxy resin (NPEL-170, Nan Ya Plastics Industry Co., Ltd.), 15 parts of diethyl aluminum hypophosphite flame retardant (op 935, manufacturer Clariant Chemical Co., Ltd.), 8 parts of MCA flame retardant (melamine cyanurate, manufacturer Jinan Jinbang Environmental Protection Technology Co., Ltd.), 0.6 parts of primary antioxidant 1010 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (manufacturer Tianjin Lianlong), 0.4 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 3 parts of acid absorber (Hycite713, Clariant Chemical), and 50 parts of solvent were mixed and stirred to obtain an emulsified dispersion and then 4 parts of curing agent (Hafotex HF-3180, Guangzhou Innova Chemical Co., Ltd.) and 60 parts of solvent (butanone) were mixed evenly to obtain an adhesive for low-temperature hot-pressing side plate insulation film.

[0075] S2: preparing low-temperature hot-pressed side panel insulating film: pre-corona-treating a 100 μm PET film, and applying the adhesive in step S1 to the corona surface of the PET film, drying it to obtain a 40 μm adhesive layer to prepare a low-temperature hot-pressed side panel insulating film.

[0076] Comparative Example 1:

[0077] A low-temperature hot-pressed side plate insulating film is prepared by the following method:

[0078] S1: By weight, 20 parts of polycarbonate polyol modified solvent-based polyester (ES-380, Guangzhou Haoyi New Materials Technology Co., Ltd.), 40 parts of bisphenol F epoxy resin (NPEL-170, Nan Ya Plastics Industry Co., Ltd.), 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.), 0.4 parts of primary antioxidant 1010 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 3 parts of acid absorber (Hycite713, Clariant Chemical), 50 parts of solvent were mixed and stirred to obtain an emulsified dispersion and then 4 parts of curing agent (Hafotex HF-3180, Guangzhou Innova Chemical Co., Ltd.) and 60 parts of solvent (butanone) were mixed evenly to obtain an adhesive for low-temperature hot-pressing side plate insulation film.

[0079] S2: preparing low-temperature hot-pressed side panel insulating film: pre-corona-treating a 100 μm PET film, and applying the adhesive in step S1 to the corona surface of the PET film, drying it to obtain a 30 μm adhesive layer to prepare a low-temperature hot-pressed side panel insulating film.

[0080] Comparative Example 2:

[0081] A low-temperature hot-pressed side plate insulating film is prepared by the following method:

[0082] S1: By weight, 60 parts of polycarbonate polyol modified solvent-based polyester (ES-380, Guangzhou Haoyi New Materials Technology Co., Ltd.), 20 parts of bisphenol F epoxy resin (NPEL-170, Nan Ya Plastics Industry Co., Ltd.), 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.), 0.4 parts of primary antioxidant 1010 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (manufacturer Tianjin Lianlong), 0.2 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 3 parts of acid absorber (Hycite713, Clariant Chemical), 50 parts of solvent were mixed and stirred to obtain an emulsified dispersion and then 4 parts of curing agent (Hafotex HF-3180, Guangzhou Innova Chemical Co., Ltd.) and 60 parts of solvent (butanone) were mixed evenly to obtain an adhesive for low-temperature hot-pressing side plate insulation film.

[0083] S2: preparing low-temperature hot-pressed side panel insulating film: pre-corona-treating a 100 μm PET film, and applying the adhesive in step S1 to the corona surface of the PET film, drying it to obtain a 30 μm adhesive layer to prepare a low-temperature hot-pressed side panel insulating film.

[0084] Comparative Example 3:

[0085] A low-temperature hot-pressed side plate insulating film is prepared by the following method:

[0086] S1: By weight, 60 parts of polycarbonate polyol modified solvent-based polyester (ES-380, Guangzhou Haoyi New Materials Technology Co., Ltd.), 50 parts of bisphenol F epoxy resin (NPEL-170, Nan Ya Plastics Industry Co., Ltd.), 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.), 0.1 parts of primary antioxidant 1010 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (manufacturer Tianjin Lianlong), 0.1 parts of secondary antioxidant 168 tris(2,4-di-tert-butylphenyl) phosphite (manufacturer Tianjin Lianlong), 1 part of acid absorber (Hycite713, Clariant Chemical), and 50 parts of solvent were mixed and stirred to obtain an emulsified dispersion and then 4 parts of curing agent (Hafotex HF-3180, Guangzhou Innova Chemical Co., Ltd.) and 60 parts of solvent (butanone) were mixed evenly to obtain an adhesive for low-temperature hot-pressing side plate insulation film.

[0087] S2: preparing low-temperature hot-pressed side panel insulating film: pre-corona-treating a 100 μm PET film, and applying the adhesive in step S1 to the corona surface of the PET film, drying it to obtain a 30 μm adhesive layer to prepare a low-temperature hot-pressed side panel insulating film.

[0088] The following performance tests were performed on the insulating thermal films prepared in the above Examples 1-3 and Comparative Examples 1-3.

[0089] 1. Peeling force test of aluminum plate

[0090] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0091] (2) Cut the tape into 25.4mm*300mm pieces, 5 pieces in total;

[0092] (3) Peel off the release layer of the tape, stick the adhesive surface to the aluminum plate with a rubber roller, and hot press the adhesive film to the surface of the aluminum plate at 120°C for 3 minutes.

[0093] (4) After curing, measure according to GB / T 2792-1998 standard, requirement: >3000gf / inch

[0094] 3. Shear test on aluminum plate

[0095] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0096] (2) Cut the tape into 25.4mm*12.5mm pieces, 5 pieces in total;

[0097] (3) Peel off the release layer of the tape, stick the adhesive surface to the aluminum plate with a rubber roller, and hot press the adhesive film to the surface of the aluminum plate at 120°C for 3 minutes.

[0098] (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;

[0099] 4. Pull-out test on aluminum plate

[0100] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0101] (2) Cut the tape into 25.4mm*25.4mm pieces, 5 pieces in total;

[0102] (3) Peel off the release layer of the tape, stick the adhesive surface to the aluminum plate with a rubber roller, and hot press the adhesive film to the surface of the aluminum plate at 120°C for 3 minutes.

[0103] (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;

[0104] 5. Aging test

[0105] (1) After sampling at different positions of the tape, place it in a standard environment for 24 hours;

[0106] (2) Peel off the release layer of the tape, stick the adhesive surface to the aluminum plate with a rubber roller, and hot press the adhesive film to the surface of the aluminum plate at 120°C for 3 minutes.

[0107] (3) Place the sample in a test box at a temperature of 85°C and a humidity of 85% for 1000 hours, perform the aluminum plate peeling test according to the first test item, and test the aged sample.

[0108] The test results are shown in Table 1 below:

[0109] Table 1

[0110]

[0111] According to the test results in Table 1, it can be seen that the low-temperature insulating hot-pressed films prepared in Examples 1-3 have excellent comprehensive properties, have high adhesion and cohesive strength with the aluminum water-cooled plate at room temperature and after aging, have a long service life, and have high insulation safety.

[0112] From the comparison between Example 1 and Comparative Example 1, it can be seen that the polycarbonate polyol-modified polyester has a certain water resistance and can improve the hydrolysis resistance and moisture resistance of the adhesive; if the addition amount is too low, the adhesive may absorb moisture in a high humidity environment, resulting in performance degradation; in a low-temperature hot pressing environment, if the adhesive absorbs moisture or is unevenly distributed, it may lead to weakened bonding strength or local failure.

[0113] From the comparison between Example 2 and Comparative Example 2, it can be seen that if the amount of bisphenol F epoxy resin added is too low, the bonding strength will be significantly reduced, especially under low temperature hot pressing conditions, the bonding effect may not meet expectations; and it will cause problems such as peeling and cracking of the adhesive layer, affecting the application performance of the adhesive in the final product.

[0114] From the comparison between Example 3 and Comparative Example 3, it can be seen that the addition of the acid absorber has no effect on the performance at room temperature, but has a great impact on the peeling force performance after aging; if the amount of the acid absorber added is too low, the acidic substances in the humid and hot environment cannot be effectively neutralized or adsorbed, resulting in more serious aging failure of the insulating film in the humid and hot environment.

[0115] 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. An adhesive for low-temperature hot-pressed side plate insulation film, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of flame retardant, 4-6 parts of curing agent, 0.3-0.7 parts of primary antioxidant, 0.2-0.4 parts of secondary antioxidant, 1-5 parts of acid absorbent and 50-150 parts of solvent.

2. The adhesive for low temperature hot pressing side plate insulation film according to claim 1, characterized in that: The modified polyester resin is one or more of polycarbonate polyol modified polyester, isophthalic acid type polyester, isophthalic acid type polyester, and polyurethane modified polyester.

3. The adhesive for low temperature hot pressing side plate insulation film according to claim 1, characterized in that: The epoxy resin is one or more of phenolic epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin and modified epoxy resin.

4. The adhesive for low temperature hot pressing side plate insulation 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.

5. The adhesive for low temperature hot pressing side plate insulation film according to claim 1, characterized in that: The primary antioxidant is one or more of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, 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 tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester and 1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

6. The adhesive for low temperature hot pressing side plate insulation film according to claim 1, characterized in that: 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 didecyl thiodipropionate; The curing agent is a blocked polyisocyanate curing agent based on hexamethylene diisocyanate; The acid absorbing agent is a hydrotalcite-based inorganic acid absorbing agent; The solvent is one or more of butanone and ethyl acetate.

7. The adhesive for low temperature hot pressing side plate insulation film according to any one of claim 1, characterized in that: The modified polyester resin is a polycarbonate polyol modified polyester; The epoxy resin is a phenolic epoxy resin or a bisphenol F epoxy resin, and the epoxy equivalent is 160-180 g / eq; The flame retardant is a mixture of diethyl aluminum hypophosphite and melamine cyanurate, the mass ratio of diethyl aluminum hypophosphite to melamine cyanurate is 8:1 to 3:1, and the particle sizes of both are 2-8 μm; 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; The auxiliary antioxidant is one or two of distearyl thiodipropionate and tris(2,4-di-tert-butylphenyl) phosphite.

8. A method for preparing an adhesive for low-temperature hot-pressed side plate insulation film according to any one of claims 1 to 7, characterized in that: The following steps are involved: By weight, 40-60 parts of modified polyester resin, 40-60 parts of epoxy resin, 30-40 parts of flame retardant, 0.3-0.7 parts of primary antioxidant, 0.2-0.4 parts of secondary antioxidant, 1-5 parts of acid absorber and 20-70 parts of solvent are mixed and stirred evenly, and then 4-6 parts of curing agent and 30-80 parts of solvent are added and stirred evenly to obtain an adhesive for low-temperature hot-pressed side panel insulation film.

9. A low temperature hot pressing insulating film, characterized in that: It is prepared by the following method: The low-temperature hot-pressed side plate insulating film adhesive as claimed in any one of claims 1 to 7 is uniformly coated on a substrate, and a low-temperature hot-pressed insulating film is obtained after curing.

10. The low temperature hot pressing insulating film according to claim 9, characterized in that: The substrate is a PET film with a thickness of 75-100 μm and is pre-corona treated; the thickness of the adhesive layer formed by coating the low-temperature hot-pressed side plate insulation film with an adhesive is 30-45 μm.

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