Boiling-resistant hot-melt adhesive film and preparation method and composite structure thereof

Abstract

The present invention relates to the technical field of hot melt adhesives, and in particular to a boiling-resistant hot melt adhesive film, a preparation method thereof and a composite structure. The boiling-resistant hot melt adhesive film comprises a first adhesive layer, an intermediate layer and a second adhesive layer which are sequentially bonded; the first adhesive layer comprises: 60 to 90 parts of polyester TPU particles, 10 to 40 parts of epoxy resin, 1 to 6 parts of tannic acid and 0.05 to 1 part of antioxidant; the intermediate layer comprises: 60 to 90 parts of ethylene-methyl acrylate copolymer, 1 to 10 parts of multifunctional organic acid and 5 to 35 parts of ethylene-methyl acrylate-methacrylate glycidyl terpolymer; the second adhesive layer comprises a polyolefin adhesive resin. The hot melt adhesive film of the present invention can effectively connect PVC waterproof coiled material and metal through a three-layer structure, and can not only effectively prevent the migration of plasticizers in PVC waterproof coiled material, but also has excellent boiling resistance, which is helpful to promote the outdoor application of PVC waterproof coiled material.

Description

Technical Field

[0001] The invention relates to the technical field of hot melt adhesives, in particular to a boiling-resistant hot melt adhesive film and a preparation method and a composite structure thereof. Background Art

[0002] PVC waterproofing membrane is a new type of synthetic material produced using PVC resin. It has the characteristics of high tensile strength, high elongation, corrosion resistance, impermeability, low shrinkage, excellent puncture resistance, and long service life. It is widely used in roof repair projects and steel structure roof waterproofing systems. Mechanical fixing method and full bonding method are traditional methods for combining PVC waterproofing membrane and metal roofing, but each has problems such as poor fixing effect, uneven thickness of glue application, and VOC emission.

[0003] Hot melt adhesive film is an environmentally friendly adhesive film. When used for the combination of PVC waterproofing membrane and metal roof, it can not only solve the problem of difficult to control the amount of glue applied and VOC emission, but also greatly save construction costs and improve construction quality and efficiency. The patent application with publication number CN109207073A discloses a three-layer composite hot melt adhesive film for bonding metal and polar functional plastics, but it cannot effectively solve the migration problem of plasticizers in PVC waterproofing membranes, resulting in insufficient durability of bonding between PVC waterproofing membranes and metals. The patent application with publication number CN114479682A discloses a hot melt adhesive film for bonding metal and PVC and its preparation method. By introducing a maleic anhydride grafted C5 / C9 copolymer resin with a high grafting rate into the first adhesive layer, the peel strength between the first adhesive layer and PVC is improved, and a strong barrier is formed in the first adhesive layer to prevent the migration of plasticizers in PVC to the first adhesive layer, thereby improving the anti-plasticizer effect of the hot melt adhesive film. However, the hot melt adhesive film has poor water boiling resistance and still has great hidden dangers if used in outdoor waterproofing projects.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] One purpose of the present invention is to provide a boiling water resistant hot melt adhesive film, which can not only solve the migration problem of plasticizers in PVC waterproof membranes, but also has good boiling water resistance, greatly promoting the outdoor application of PVC waterproof membranes.

[0006] Another object of the present invention is to provide a method for preparing a boiling-resistant hot-melt adhesive film.

[0007] Another object of the present invention is to provide a composite structure of PVC waterproof coiled material and metal.

[0008] In order to achieve the above-mentioned object of the present invention, the present invention provides a boiling-resistant hot-melt adhesive film, comprising a first adhesive layer, an intermediate layer and a second adhesive layer laminated in sequence;

[0009] The first adhesive layer comprises the following components by weight: 60-90 parts of polyester TPU particles, 10-40 parts of epoxy resin, 1-6 parts of tannic acid and 0.05-1 part of antioxidant;

[0010] The intermediate layer comprises the following components by weight: 60 to 90 parts of ethylene-methyl acrylate copolymer, 1 to 10 parts of multifunctional organic acid and 5 to 35 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer;

[0011] The second adhesive layer includes a polyolefin adhesive resin.

[0012] In a specific embodiment of the present invention, the epoxy value of the epoxy resin is 0.1 to 0.5 eq / 100g.

[0013] In a specific embodiment of the present invention, the melting point of the polyester TPU particles is 100-160° C., and the melt index under the test conditions of 190° C. and 2.16 kg is 15-50 g / 10 min.

[0014] In a specific embodiment of the present invention, the multifunctional organic acid includes at least one of malic acid and citric acid.

[0015] In a specific embodiment of the present invention, the mass ratio of the epoxy resin to the tannic acid is (3-15) : 1, preferably (4-12) : 1.

[0016] In a specific embodiment of the present invention, the content of the GMA block in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 3 wt % to 6 wt %.

[0017] In a specific embodiment of the present invention, the mass ratio of the multifunctional organic acid to the GMA in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 1:(0.06-0.36), preferably 1:(0.08-0.32).

[0018] In a specific embodiment of the present invention, polar groups are grafted into the polyolefin adhesive resin, and the polar groups include maleic anhydride and / or carboxyl groups. Further, in the polyolefin adhesive resin, the grafting rate of polar groups is 0.1% to 1.5%, preferably 0.15% to 1.0%.

[0019] In a specific embodiment of the present invention, the ratio of the thickness of the first adhesive layer, the intermediate layer and the second adhesive layer is (1-2):1:(1-2).

[0020] In a specific embodiment of the present invention, the thickness of the boiling-resistant hot-melt adhesive film is 0.03-0.15 mm.

[0021] Another aspect of the present invention provides a method for preparing any one of the above-mentioned boiling-resistant hot-melt adhesive films, comprising the following steps:

[0022] The first adhesive layer raw material, the middle layer raw material and the second adhesive layer raw material are subjected to multi-layer co-extrusion blown film or cast film to obtain the boiling-resistant hot-melt adhesive film.

[0023] Another aspect of the present invention provides a composite structure, comprising a PVC waterproof coiled material, a boiling-resistant hot-melt adhesive film and a metal layer laminated in sequence; the boiling-resistant hot-melt adhesive film is any one of the boiling-resistant hot-melt adhesive films described above.

[0024] In a specific embodiment of the present invention, the first adhesive layer of the boiling-resistant hot-melt adhesive film is bonded to the PVC waterproof coiled material, and the second adhesive layer of the boiling-resistant hot-melt adhesive film is bonded to the metal layer.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The hot melt adhesive film of the present invention is configured with a three-layer structure, which can effectively connect the PVC waterproof membrane and the metal, and the substrate and the adhesive film, as well as the layers of the adhesive film, can show strong interactions, which can not only effectively prevent the migration of plasticizers in the PVC waterproof membrane, but also has excellent boiling water resistance, which is helpful to promote the outdoor application of PVC waterproof membrane;

[0027] (2) The preparation process of the hot melt adhesive film of the present invention is simple and can be produced continuously. DETAILED DESCRIPTION

[0028] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be appreciated by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work, all belong to the scope of protection of the present invention. If specific conditions are not indicated in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0029] In one aspect, the present invention provides a boiling-resistant hot-melt adhesive film, comprising a first adhesive layer, an intermediate layer and a second adhesive layer laminated in sequence;

[0030] The first adhesive layer includes the following components by weight: 60-90 parts of polyester TPU particles, 10-40 parts of epoxy resin, 1-6 parts of tannic acid and 0.05-1 part of antioxidant;

[0031] The middle layer comprises the following components by weight: 60-90 parts of ethylene-methyl acrylate copolymer, 1-10 parts of multifunctional organic acid and 5-35 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer;

[0032] The second adhesive layer includes a polyolefin adhesive resin.

[0033] The hot melt adhesive film of the present invention is arranged with a three-layer structure, which can effectively connect the PVC waterproof membrane and the metal, and there is a strong interaction between the substrate and the adhesive film, and between each layer of the adhesive film. It can not only effectively prevent the migration of plasticizers in the PVC waterproof membrane, but also the hot melt adhesive film has excellent water boiling resistance, which helps to promote the outdoor application of PVC waterproof membrane.

[0034] Among them, in the first adhesive layer, the hydrolysis resistance of the polyester TPU is improved through the synergistic effect of the epoxy resin and tannic acid. When the polyester TPU is hydrolyzed, the carboxyl or hydroxyl groups produced by the hydrolysis will react chemically with the epoxy resin, thereby preventing the further hydrolysis of the polyester TPU. In addition, tannic acid, epoxy resin and organic acid will form a cross-linked network structure, which can not only effectively prevent the migration of plasticizers in PVC waterproof coiled materials, but also significantly improve the bonding strength between the first adhesive layer and the intermediate layer, and further improve the hydrolysis resistance of the polyester TPU.

[0035] The composition design of the middle layer can improve the bonding strength between the middle layer and the first bonding layer and the second bonding layer. The present invention has found that the ethylene-methyl acrylate copolymer in the middle layer has good initial bonding performance with both the polyester TPU and the polyolefin bonding resin. The use of ethylene-methyl acrylate copolymer as the matrix resin of the middle layer helps to improve the bonding between the layers. The addition of the ethylene-methyl acrylate-glycidyl methacrylate terpolymer in the middle layer can improve the compatibility between the matrix and the organic acid on the one hand, and on the other hand, under the promotion of the organic acid, it can react chemically with some polar groups in the second bonding layer, such as maleic anhydride groups, to further improve the bonding stability between the middle layer and the second bonding layer.

[0036] In the first adhesive layer of the present invention, the amounts of the components in parts by weight may be as follows:

[0037] The dosage of polyester TPU particles can be 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts or a range consisting of any two of them; according to diffusion theory and experimental verification, TPU has good adhesion to PVC, and polyester TPU has higher cohesive strength than polyether TPU, and stronger adhesion to polar substrates, so polyester TPU is selected as the base resin for bonding PVC waterproof membrane.

[0038] The amount of epoxy resin can be 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts or any two of them; although polyester TPU has good adhesion to PVC, the ester group in polyester TPU is easily hydrolyzed, resulting in damage to the TPU structure, which in turn leads to decreased mechanical properties and bonding reliability. The present invention utilizes the reaction of carboxyl or hydroxyl groups generated by the hydrolysis of epoxy resin and polyester TPU to prevent further hydrolysis of polyester TPU.

[0039] The dosage of tannic acid can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts or a range consisting of any two of them; tannic acid contains multiple phenolic hydroxyl groups, and tannic acid itself is difficult to react chemically with epoxy resin, but under the action of the organic acid in the middle layer, the three form a cross-linked network structure, which not only further improves the hydrolysis resistance of the polyester TPU, but also prevents the migration of plasticizers in the PVC waterproof membrane, and improves the bonding strength between the first bonding layer and the middle layer.

[0040] The amount of the antioxidant can be 0.05 parts, 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 part or any two of them; the addition of the antioxidant can prevent the thermal oxidation degradation of the polyester TPU during the production and processing, and maintain the mechanical strength of the matrix resin. The antioxidant includes but is not limited to at least one of antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 264, antioxidant B245, antioxidant TPP, and antioxidant TNP.

[0041] In the intermediate layer of the present invention, the amounts of the components in parts by weight can be as follows:

[0042] The amount of ethylene-methyl acrylate copolymer can be 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts or a range consisting of any two of them.

[0043] The dosage of the multifunctional organic acid can be 1 part, 2 parts, 5 parts, 8 parts, 10 parts or a range consisting of any two of them; the multifunctional organic acid is added to the middle layer, which can not only react with the epoxy resin and tannic acid in the first bonding layer to improve water resistance, but also form a cross-linked network structure to prevent plasticizer migration, and improve the bonding strength between the first bonding layer and the middle layer; it can also promote the reaction between the components of the middle layer and the second bonding layer, thereby improving the bonding strength between the middle layer and the second bonding layer.

[0044] The amount of ethylene-methyl acrylate-glycidyl methacrylate terpolymer can be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts or a range consisting of any two of them; ethylene-methyl acrylate-glycidyl methacrylate terpolymer.

[0045] In a specific embodiment of the present invention, the epoxy value of the epoxy resin is 0.1 to 0.5 eq / 100 g. The epoxy resin is preferably a bisphenol A epoxy resin.

[0046] The epoxy group and hydroxyl group in bisphenol A epoxy resin give the resin good reactivity, so that the cured resin has strong cohesion and adhesion. When the epoxy value is too high, the epoxy resin cures more violently, the reaction is difficult to control, and the processing performance of the hot melt adhesive film is affected; when the epoxy value is too low, the improvement effect on the boiling resistance and anti-plasticizer migration performance is insufficient. For example, in different embodiments, the epoxy value of the epoxy resin can be 0.1eq / 100g, 0.2eq / 100g, 0.3eq / 100g, 0.4eq / 100g, 0.5eq / 100g, or a range consisting of any two of them.

[0047] In a specific embodiment of the present invention, the melting point of the polyester TPU particles is 100-160° C., and the melt index under the test conditions of 190° C. and 2.16 kg is 15-50 g / 10 min.

[0048] The first adhesive layer uses polyester TPU particles as the base resin, which has certain temperature resistance and moderate fluidity to meet outdoor application scenarios and film processing properties. For example, in different embodiments, the melting point of the polyester TPU particles can be 100°C, 120°C, 140°C, 160°C, or a range consisting of any two thereof; the melt index under the test conditions of 190°C and 2.16kg can be 15g / 10min, 20g / 10min, 25g / 10min, 35g / 10min, 45g / 10min, 50g / 10min, or a range consisting of any two thereof.

[0049] In a specific embodiment of the present invention, the multifunctional organic acid includes at least one of malic acid and citric acid.

[0050] In a specific embodiment of the present invention, the mass ratio of epoxy resin to tannic acid is (3-15) : 1, preferably (4-12) : 1.

[0051] For example, in different embodiments, the mass ratio of epoxy resin to tannic acid can be 3:1, 4:1, 5:1, 6:1, 8:1, 10:1, 12:1, 15:1, or any two thereof. Regulating the mass ratio of epoxy resin to tannic acid within the above range is more conducive to improving the performance of both water boiling resistance and peel strength.

[0052] In a specific embodiment of the present invention, the content of the GMA block in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 3 wt % to 6 wt %.

[0053] On the one hand, the ethylene-methyl acrylate-glycidyl methacrylate terpolymer can improve the compatibility of organic acids in the middle layer. On the other hand, the ethylene-methyl acrylate-glycidyl methacrylate terpolymer with a certain GMA content can react chemically with polar groups such as maleic anhydride in the second adhesive layer under the promotion of organic acids to improve bonding stability. However, when the GMA content is too high, the reactivity of polar groups in the polyolefin adhesive resin with metals will be deteriorated, thereby affecting the bonding of the second adhesive layer with metals. For example, in different embodiments, in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer, the content of the GMA block can be 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, 5.5wt%, 6wt% or a range consisting of any two of them.

[0054] In a specific embodiment of the present invention, the mass ratio of the multifunctional organic acid to GMA in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 1:(0.06-0.36), preferably 1:(0.08-0.32).

[0055] For example, in different embodiments, the mass ratio of the multifunctional organic acid to the GMA in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer can be 1:0.06, 1:0.09, 1:0.1, 1:0.12, 1:0.15, 1:0.18, 1:0.2, 1:0.22, 1:0.25, 1:0.28, 1:0.3, 1:0.32, 1:0.35, 1:0.36 or a range consisting of any two of them. Regulating the mass ratio of the organic acid to the GMA in the copolymer within the above range is more conducive to improving the boiling resistance of the hot melt adhesive film and the bonding strength between the layers. Among them, the mass of GMA in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer refers to the amount of the GMA block in the terpolymer.

[0056] In a specific embodiment of the present invention, the melt index of the ethylene-methyl acrylate copolymer under the test conditions of 190° C. and 2.16 kg is 1 to 10 g / 10 min.

[0057] For example, in different embodiments, the melt index of ethylene-methyl acrylate copolymer under the test conditions of 190°C and 2.16 kg can be 1 g / 10 min, 2 g / 10 min, 5 g / 10 min, 8 g / 10 min, 10 g / 10 min or a range of any two thereof to further ensure good film processing properties.

[0058] In a specific embodiment of the present invention, the polyolefin adhesive resin has a melt index of 1 to 5 g / 10 min under the test conditions of 190° C. and 2.16 kg.

[0059] For example, in different embodiments, the melt index of the polyolefin adhesive resin under the test conditions of 190° C. and 2.16 kg can be 1 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, or a range composed of any two of them.

[0060] In a specific embodiment of the present invention, polar groups are grafted into the polyolefin adhesive resin, and the polar groups include maleic anhydride and / or carboxyl groups. Further, in the polyolefin adhesive resin, the grafting rate of polar groups is 0.1% to 1.5%, preferably 0.15% to 1.0%.

[0061] For example, in different embodiments, the grafting rate of polar groups in the polyolefin adhesive resin can be 0.1%, 0.2%, 0.5%, 0.8%, 1%, 1.2%, 1.5% or a range consisting of any two thereof. In actual operation, a polyolefin adhesive resin of VB grade produced by Guangzhou Lushan New Materials Co., Ltd., such as at least one of VB550, VB530, VB770 and VB760, can be used. On the one hand, it can react chemically with the ethylene-methyl acrylate-glycidyl methacrylate terpolymer in the middle layer under the promotion of organic acid to improve the interlayer bonding stability. On the other hand, it has good adhesion to metals and meets the requirements of outdoor engineering applications.

[0062] In a specific embodiment of the present invention, the ratio of the thickness of the first adhesive layer, the intermediate layer and the second adhesive layer is (1-2):1:(1-2).

[0063] Regulating the thickness of each layer within the above range is more conducive to effectively forming a cross-linked network structure in the first adhesive layer that can prevent the migration of plasticizers and effectively improve water resistance; at the same time, the bonding strength between the layers is guaranteed. For example, in different embodiments, the thickness ratio of the first adhesive layer, the intermediate layer, and the second adhesive layer can be 1:1:1, 1.5:1:1, 2:1:1, 1:1:1.5, 1:1:2, 1.5:1:1.5, 2:1:1.5, etc., but is not limited thereto.

[0064] In a specific embodiment of the present invention, the thickness of the boiling-resistant hot-melt adhesive film is 0.03-0.15 mm.

[0065] For example, in different embodiments, the thickness of the boiling-resistant hot-melt adhesive film can be 0.03 mm, 0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, or a range consisting of any two of them.

[0066] Another aspect of the present invention provides a method for preparing any one of the above-mentioned boiling-resistant hot-melt adhesive films, comprising the following steps:

[0067] The first adhesive layer raw material, the middle layer raw material and the second adhesive layer raw material are subjected to multi-layer co-extrusion blown film or cast film to obtain a boiling-resistant hot-melt adhesive film.

[0068] Among them, the co-extrusion blown film can be carried out by a blown film machine, and the co-extrusion cast film can be carried out by a cast film machine. The extrusion temperatures of the co-extrusion blown film or cast film of the first adhesive layer, the middle layer, and the second adhesive layer are 140-170°C, 150-190°C, and 140-190°C, respectively, and the co-extrusion die head temperature is 140-160°C.

[0069] In a specific embodiment of the present invention, the preparation of the raw material for the first bonding layer includes: mixing according to the components of the first bonding layer, extruding and granulating; wherein the twin-screw extruder has a total of 11 temperature zones, and the temperature in each temperature zone is as follows: 40°C, 80°C, 120°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, 140-170°C, and the die temperature is 140-170°C.

[0070] In a specific embodiment of the present invention, the preparation of the middle layer raw material includes: mixing according to the components of the middle layer, extruding and granulating; wherein the twin-screw extruder has a total of 11 temperature zones, and the temperature of each temperature zone is as follows: 40°C, 80°C, 120°C, 150-190°C, 150-190°C, 150-190°C, 150-190°C, 150-190°C, 150-190°C, 150-190°C, 150-190°C, 150-190°C, and the die temperature is 150-190°C.

[0071] In actual operation, the mixing operation can be carried out in a high-speed mixer, and the extrusion granulation operation can be carried out in a twin-screw extruder.

[0072] Another aspect of the present invention provides a composite structure, comprising a PVC waterproof coiled material, a boiling-resistant hot-melt adhesive film and a metal layer laminated in sequence; the boiling-resistant hot-melt adhesive film is any one of the above-mentioned boiling-resistant hot-melt adhesive films.

[0073] In a specific embodiment of the present invention, the first adhesive layer of the boiling-resistant hot-melt adhesive film is laminated to the PVC waterproof coiled material, and the second adhesive layer of the boiling-resistant hot-melt adhesive film is laminated to the metal layer.

[0074] When the boiling-resistant hot-melt adhesive film of the present invention is composited with a PVC waterproof coiled material and a galvanized sheet, the 180° room temperature peeling strength may be ≥135N / 25mm, such as 138N / 25mm, 140N / 25mm, 145N / 25mm, 150N / 25mm, 155N / 25mm, 160N / 25mm, etc.; the 180° room temperature peeling strength after boiling in water for 4 hours may be ≥127N / 25mm, such as 130N / 25mm, 140N / 25mm, 145N / 25mm, 150N / 25mm, 155N / 25mm, 160N / 25mm, etc.; the peeling strength retention rate after boiling in water for 4 hours is greater than 90%, such as 92%, 95%, 98%, 100%, etc.

[0075] Example 1

[0076] This embodiment provides a boiling-resistant hot-melt adhesive film, comprising a first adhesive layer, an intermediate layer and a second adhesive layer laminated in sequence. The thickness of the first adhesive layer is 0.03 mm, the thickness of the intermediate layer is 0.02 mm, and the thickness of the second adhesive layer is 0.03 mm.

[0077] The raw materials of the first bonding layer include the following components by weight: 80 parts of polyester TPU particles, 18 parts of epoxy resin, 2 parts of tannic acid, and 0.3 parts of antioxidant. The polyester TPU particles have a melting point of 130-140°C and a melt index of 40g / 10min (190°C / 2.16kg), purchased from Zhejiang Huafeng Thermoplastic Polyurethane Co., Ltd., with a brand name of HF-3H80A-6; the epoxy resin is bisphenol A type epoxy resin E-44, with an epoxy value of 0.44eq / 100g; the CAS number of tannic acid is 1401-55-4; and the antioxidant is selected from antioxidant 1010.

[0078] The raw materials of the middle layer include the following components by weight: 70 parts of ethylene-methyl acrylate copolymer (EMA), 5 parts of organic acid, and 25 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA). The EMA brand is Optema TC 111, and the melt index is 2g / 10min (190℃ / 2.16kg); the organic acid is malic acid, and the CAS number is 6915-15-7; the GMA content of EMA-GMA is 6wt%, and the brand is Japan Sumitomo BF-7M.

[0079] The raw material of the second adhesive layer is hot melt adhesive particles VB550 (Guangzhou Lushan New Materials Co., Ltd.).

[0080] The method for preparing the boiling-resistant hot-melt adhesive film of this embodiment comprises the following steps:

[0081] (a) First, the raw materials of the first adhesive layer and the intermediate layer are uniformly mixed in a high-speed mixer according to their proportions, and then melt-extruded and granulated in a twin-screw extruder to obtain pellets of the first adhesive layer and pellets of the intermediate layer, respectively. When the first adhesive layer is extruded and granulated, the twin-screw extruder includes 11 temperature zones, and the temperatures of each temperature zone are: 40°C, 80°C, 120°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, and the die head temperature is 150°C; when the intermediate layer is extruded and granulated, the twin-screw extruder includes 11 temperature zones, and the temperatures of each temperature zone are: 40°C, 80°C, 120°C, 160°C, 160°C, 160°C, 160°C, 160°C, 160°C, 160°C, 160°C, and the die head temperature is 160°C.

[0082] (b) The pellets of the first adhesive layer, the pellets of the middle layer and the pellets of the second adhesive layer are blown on a three-layer co-extrusion film blowing machine to obtain corresponding hot melt adhesive films, wherein the thickness of the first adhesive layer is 0.03 mm, the thickness of the middle layer is 0.02 mm, and the thickness of the second adhesive layer is 0.03 mm. During the co-extrusion film blowing, the extrusion section temperature of the first adhesive layer is 150°C, the extrusion section temperature of the middle layer is 160°C, the extrusion section temperature of the second adhesive layer is 150°C, and the temperature of the co-extrusion die head is 150°C.

[0083] Example 2

[0084] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the type of epoxy resin in the first adhesive layer is different.

[0085] In this embodiment, the epoxy resin is bisphenol A type epoxy resin E-12, and the epoxy value is 0.10eq / 100g.

[0086] Example 3

[0087] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the type of epoxy resin in the first adhesive layer is different.

[0088] In this embodiment, the epoxy resin is bisphenol A epoxy resin E-51, and the epoxy value is 0.50 eq / 100 g.

[0089] Example 4

[0090] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the type of epoxy resin in the first adhesive layer is different.

[0091] In this embodiment, the epoxy resin is bisphenol A epoxy resin E-55, and the epoxy value is 0.55 eq / 100 g.

[0092] Example 5

[0093] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the amounts of epoxy resin and tannic acid used in the first adhesive layer are different.

[0094] In this embodiment, the epoxy resin is 15 parts and the tannic acid is 5 parts.

[0095] Example 6

[0096] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the amounts of epoxy resin and tannic acid used in the first adhesive layer are different.

[0097] In this embodiment, the epoxy resin is 19 parts and the tannic acid is 1 part.

[0098] Example 7

[0099] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the types of EMA-GMA in the middle layer are different.

[0100] In this embodiment, the GMA content of EMA-GMA is 8 wt %, and the brand is French Arkema AX 8900.

[0101] Example 8

[0102] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the amounts of the components in the middle layer are different.

[0103] In this embodiment, the raw materials of the middle layer include the following components in parts by weight: 90 parts of ethylene-methyl acrylate copolymer (EMA), 5 parts of organic acid, and 5 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA).

[0104] Example 9

[0105] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, with the only difference being that the amounts of the components in the middle layer are different.

[0106] In this embodiment, the raw materials of the middle layer include the following components in parts by weight: 65 parts of ethylene-methyl acrylate copolymer (EMA), 5 parts of organic acid, and 30 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA).

[0107] Example 10

[0108] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, except that the components, amounts and thicknesses of each layer are different.

[0109] In this embodiment, the thickness of the first adhesive layer is 0.02 mm, the thickness of the middle layer is 0.02 mm, and the thickness of the second adhesive layer is 0.02 mm.

[0110] The raw materials of the first bonding layer include the following components by weight: 70 parts of polyester TPU particles, 26 parts of epoxy resin, 4 parts of tannic acid, and 0.5 parts of antioxidant. The polyester TPU particles have a melting point of 118-128°C and a melt index of 32g / 10min (190°C / 2.16kg), purchased from Wanhua Chemical Group Co., Ltd., with a brand name of WHT-6229; the epoxy resin is bisphenol A type epoxy resin NPES-901, with an epoxy value of 0.22eq / 100g; the CAS number of tannic acid is 1401-55-4; and the antioxidant is selected from antioxidant B245.

[0111] The raw materials of the middle layer include the following components by weight: 80 parts of ethylene-methyl acrylate copolymer (EMA), 3 parts of organic acid, and 17 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA). The EMA brand is Optema TC 220, and the melt index is 5g / 10min (190℃ / 2.16kg); the organic acid is malic acid, and the CAS number is 6915-15-7; the GMA content of EMA-GMA is 3wt%, and the brand is Japan Sumitomo BF-7L.

[0112] The raw material of the second adhesive layer is hot melt adhesive particles VB530 (Guangzhou Lushan New Materials Co., Ltd.).

[0113] Embodiment 11

[0114] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, except that the components, amounts and thicknesses of each layer are different.

[0115] In this embodiment, the thickness of the first adhesive layer is 0.04 mm, the thickness of the middle layer is 0.02 mm, and the thickness of the second adhesive layer is 0.03 mm.

[0116] The raw materials of the first bonding layer include the following components by weight: 85 parts of polyester TPU particles, 12 parts of epoxy resin, 3 parts of tannic acid, and 0.6 parts of antioxidant. The polyester TPU particles have a melting point of 100-110°C and a melt index of 25g / 10min (190°C / 2.16kg), purchased from Wanhua Chemical Group Co., Ltd., with a brand name of WHT-6232B; the epoxy resin is bisphenol A type epoxy resin NPES-904, with an epoxy value of 0.12eq / 100g; the CAS number of tannic acid is 1401-55-4; and the antioxidant is selected from antioxidant 1098.

[0117] The raw materials of the middle layer include the following components by weight: 65 parts of ethylene-methyl acrylate copolymer (EMA), 8 parts of organic acid, and 27 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA). The EMA brand is Optema TC 121, and the melt index is 65g / 10min (190℃ / 2.16kg); the organic acid is malic acid, and the CAS number is 6915-15-7; the GMA content of EMA-GMA is 3wt%, and the brand is Japan Sumitomo BF-7L.

[0118] The raw material of the second adhesive layer is hot melt adhesive particles VB550 (Guangzhou Lushan New Materials Co., Ltd.).

[0119] Example 12

[0120] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, except that the components, amounts and thicknesses of each layer are different.

[0121] In this embodiment, the thickness of the first adhesive layer is 0.05 mm, the thickness of the middle layer is 0.03 mm, and the thickness of the second adhesive layer is 0.04 mm.

[0122] The raw materials of the first bonding layer include the following components by weight: 65 parts of polyester TPU particles, 29 parts of epoxy resin, 6 parts of tannic acid, and 0.2 parts of antioxidant. The polyester TPU particles have a melting point of 110-120°C and a melt index of 45g / 10min (190°C / 2.16kg), purchased from Wanhua Chemical Group Co., Ltd., with a brand name of WHT-6232B; the epoxy resin is bisphenol A type epoxy resin E-35, with an epoxy value of 0.35eq / 100g; the CAS number of tannic acid is 1401-55-4; and the antioxidant is selected from antioxidant TPP.

[0123] The raw materials of the middle layer include the following components by weight: 75 parts of ethylene-methyl acrylate copolymer (EMA), 6 parts of organic acid, and 19 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA). The EMA brand is Optema TC 114, and the melt index is 3.2g / 10min (190℃ / 2.16kg); the organic acid is citric acid, and the CAS number is 77-92-9; the GMA content of EMA-GMA is 6wt%, and the brand is Japan Sumitomo BF-7M.

[0124] The raw material of the second adhesive layer is hot melt adhesive particles VB770 (Guangzhou Lushan New Materials Co., Ltd.).

[0125] Embodiment 13

[0126] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, except that the components, amounts and thicknesses of each layer are different.

[0127] In this embodiment, the thickness of the first adhesive layer is 0.02 mm, the thickness of the middle layer is 0.01 mm, and the thickness of the second adhesive layer is 0.01 mm.

[0128] The raw materials of the first bonding layer include the following components by weight: 75 parts of polyester TPU particles, 23 parts of epoxy resin, 2 parts of tannic acid, and 0.4 parts of antioxidant. The polyester TPU particles have a melting point of 145-155°C and a melt index of 35g / 10min (190°C / 2.16kg), purchased from Zhejiang Huafeng Thermoplastic Polyurethane Co., Ltd., with a brand name of WHT-6235B; the epoxy resin is bisphenol A type epoxy resin E-20, with an epoxy value of 0.20eq / 100g; the CAS number of tannic acid is 1401-55-4; and the antioxidant is selected from antioxidant TNP.

[0129] The raw materials of the middle layer include the following components by weight: 85 parts of ethylene-methyl acrylate copolymer (EMA), 5 parts of organic acid, and 10 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA). The EMA brand is Optema TC 120, and the melt index is 6g / 10min (190℃ / 2.16kg); the organic acid is citric acid, and the CAS number is 77-92-9; the GMA content of EMA-GMA is 6wt%, and the brand is Japan Sumitomo BF-7M.

[0130] The raw material of the second adhesive layer is hot melt adhesive particles VB770 (Guangzhou Lushan New Materials Co., Ltd.).

[0131] Embodiment 14

[0132] This embodiment refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Embodiment 1, except that the components, amounts and thicknesses of each layer are different.

[0133] In this embodiment, the thickness of the first adhesive layer is 0.03 mm, the thickness of the middle layer is 0.02 mm, and the thickness of the second adhesive layer is 0.02 mm.

[0134] The raw materials of the first bonding layer include the following components by weight: 60 parts of polyester TPU particles, 35 parts of epoxy resin, 5 parts of tannic acid, and 0.1 parts of antioxidant. The polyester TPU particles have a melting point of 118-128°C and a melt index of 32g / 10min (190°C / 2.16kg), purchased from Wanhua Chemical Group Co., Ltd., with a brand name of WHT-6672; the epoxy resin is bisphenol A type epoxy resin E-42, with an epoxy value of 0.42eq / 100g; the CAS number of tannic acid is 1401-55-4; and the antioxidant is selected from antioxidant 264.

[0135] The raw materials of the middle layer include the following components by weight: 60 parts of ethylene-methyl acrylate copolymer (EMA), 9 parts of organic acid, and 31 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA). The EMA brand is Optema TC 110, and the melt index is 2g / 10min (190℃ / 2.16kg); the organic acid is citric acid, and the CAS number is 77-92-9; the GMA content of EMA-GMA is 3wt%, and the brand is Japan Sumitomo BF-7L.

[0136] The raw material of the second adhesive layer is hot melt adhesive particles VB530 (Guangzhou Lushan New Materials Co., Ltd.).

[0137] Comparative Example 1

[0138] Comparative Example 1 refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Example 1, except that the components of each layer are different.

[0139] In Comparative Example 1, the raw material of the first adhesive layer is polyester TPU particles; the raw material of the middle layer is ethylene-methyl acrylate copolymer (EMA); and the raw material of the second adhesive layer is hot-melt adhesive particles VB550.

[0140] Comparative Example 2

[0141] Comparative Example 2 refers to the boiling-resistant hot-melt adhesive film and its preparation method of Example 1, except that: the amount of components used in the first adhesive layer is different.

[0142] In Comparative Example 2, the raw materials of the first adhesive layer include the following components in parts by weight: 98 parts of polyester TPU particles, 2 parts of tannic acid, and 0.3 parts of antioxidant.

[0143] Comparative Example 3

[0144] Comparative Example 3 refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Example 1, except that: the amount of components used in the first adhesive layer is different.

[0145] In Comparative Example 3, the raw materials of the first adhesive layer include the following components in parts by weight: 80 parts of polyester TPU particles, 18 parts of epoxy resin, and 0.3 parts of antioxidant.

[0146] Comparative Example 4

[0147] Comparative Example 4 refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Example 1, except that: the dosage of the components of the middle layer is different.

[0148] In Comparative Example 4, the raw materials of the middle layer include the following components in parts by weight: 75 parts of ethylene-methyl acrylate copolymer (EMA) and 25 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMA-GMA).

[0149] Comparative Example 5

[0150] Comparative Example 5 refers to the boiling-resistant hot-melt adhesive film and preparation method thereof of Example 1, except that: the dosage of the components of the middle layer is different.

[0151] In Comparative Example 5, the raw materials of the middle layer include the following components in parts by weight: 95 parts of ethylene-methyl acrylate copolymer (EMA) and 5 parts of organic acid.

[0152] Experimental example

[0153] The hot melt adhesive film obtained in each embodiment and comparative example was compounded with a PVC waterproof membrane and a galvanized sheet, and the compounding process was as follows: the PVC waterproof membrane was first pre-laminated with the first adhesive layer of the hot melt adhesive film, and then the second adhesive layer of the hot melt adhesive film was laminated on the heated galvanized sheet, wherein the compounding temperature was 170°C, the compounding time was 20s, and the compounding pressure was 0.2MPa, to obtain a bonding structure of PVC waterproof membrane / first adhesive layer / middle layer / second adhesive layer / galvanized sheet, and the 180° room temperature peel strength and boiling resistance of the bonding structure were investigated, and the test results are shown in Table 1. Among them, 180° room temperature peel strength refers to the 180° peel strength test after cooling to room temperature after lamination; boiling resistance refers to the PVC waterproof membrane / first bonding layer / middle layer / second bonding layer / galvanized sheet bonding structure is put into water for boiling (temperature is 100°C, time is 4h) after lamination, and then the sample is taken out and cooled to room temperature for 180° peel strength test.

[0154] Table 1 180° room temperature peel strength and boiling water resistance test results of different bonding structures

[0155]

[0156] By comparing the test results of Example 1 and Comparative Examples 1 to 5, it can be seen that the addition of epoxy resin can greatly improve the hydrolysis resistance of polyester TPU, and the cross-linked network formed by epoxy resin, tannic acid and organic acid greatly improves the bonding strength between the first bonding layer and the middle layer and the boiling water resistance between the layers; EMA-GMA improves the compatibility between EMA and organic acids, and improves the bonding strength between the middle layer and the second bonding layer and the boiling water resistance between the layers.

[0157] According to the embodiments of the present invention, after the hot melt adhesive film prepared by the preferred formula of the present invention is combined with PVC waterproof coiled material and galvanized sheet, the peel strength can reach more than 135N / 25mm, and the peel strength retention rate after boiling in water for 4 hours is higher than 90%, indicating that the hot melt adhesive film of the present invention has excellent peel strength and boiling resistance. In addition, the preparation process of the hot melt adhesive film of the present invention is simple and can be continuously produced, which can greatly promote the outdoor application of PVC waterproof coiled material.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Boiling resistant hot melt adhesive film, It is characterized in that It includes a first adhesive layer, an intermediate layer and a second adhesive layer which are laminated in sequence; The first adhesive layer comprises the following components by weight: 60-90 parts of polyester TPU particles, 10-40 parts of epoxy resin, 1-6 parts of tannic acid and 0.05-1 part of antioxidant; The intermediate layer comprises the following components by weight: 60 to 90 parts of ethylene-methyl acrylate copolymer, 1 to 10 parts of multifunctional organic acid and 5 to 35 parts of ethylene-methyl acrylate-glycidyl methacrylate terpolymer; The second adhesive layer includes a polyolefin adhesive resin; The epoxy value of the epoxy resin is 0.1 to 0.5 eq / 100 g; The mass ratio of the epoxy resin to the tannic acid is (4-15):1; In the ethylene-methyl acrylate-glycidyl methacrylate terpolymer, the content of glycidyl methacrylate block is 3wt% to 6wt%; polar groups are grafted into the polyolefin adhesive resin, and the polar groups include maleic anhydride and / or carboxyl groups.

2. The boiling-resistant hot-melt adhesive film according to claim 1, It is characterized in that The polyester TPU particles have a melting point of 100 to 160° C., and a melt index of 15 to 50 g / 10 min under the test conditions of 190° C. and 2.16 kg.

3. The boiling-resistant hot-melt adhesive film according to claim 1, It is characterized in that The multifunctional organic acid includes at least one of malic acid and citric acid.

4. The boiling-resistant hot-melt adhesive film according to claim 1, It is characterized in that The mass ratio of the multifunctional organic acid to the glycidyl methacrylate in the ethylene-methyl acrylate-glycidyl methacrylate terpolymer is 1:(0.06-0.36).

5. The boiling-resistant hot-melt adhesive film according to claim 1, It is characterized in that In the polyolefin adhesive resin, the grafting rate of polar groups is 0.1% to 1.5%.

6. The method for preparing the boiling-resistant hot-melt adhesive film according to any one of claims 1 to 5, It is characterized in that The steps include: The first adhesive layer raw material, the middle layer raw material and the second adhesive layer raw material are subjected to multi-layer co-extrusion blown film or cast film to obtain the boiling-resistant hot-melt adhesive film.

7. A composite structure, It is characterized in that It comprises a PVC waterproof coiled material, a boiling-resistant hot-melt adhesive film and a metal layer which are laminated in sequence; the boiling-resistant hot-melt adhesive film is the boiling-resistant hot-melt adhesive film according to any one of claims 1 to 5 or the boiling-resistant hot-melt adhesive film prepared by the preparation method according to claim 6.

Images