Adhesive special for ultra-low surface energy base material and preparation method thereof

Abstract

The invention relates to a hot melt adhesive composition and a preparation method thereof, in particular to a multi-layer hot melt adhesive suitable for a low-surface-energy polyolefin base material, which has good wettability, bonding strength, damp heat resistance and ultraviolet light resistance stability, and is suitable for the industrial application fields of plastic films, sheets, composite materials and the like. The preparation raw materials comprise a styrene-isoprene-styrene block copolymer, hydrogenated hydrocarbon resin, liquid polyisobutene, a hindered phenol antioxidant and an ultraviolet absorbent. The hot melt adhesive disclosed by the invention is suitable for continuous hot melt coating production, uniform in coating and simple and convenient to operate, and can be widely applied to the industrial fields of plastic films, composite materials, automotive upholstery, electronic components and the like. Compared with the prior art, the bonding reliability of the low-surface-energy material is improved, meanwhile, the industrial preparation process is simplified, the production efficiency is improved, and the method has remarkable market application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymers, in particular to an adhesive special for ultra-low surface energy substrates and a preparation method thereof. BACKGROUND

[0002] Polyolefin low surface energy materials (PP, PE, etc.) have low surface energy (usually 30-35 mN / m) and lack of polar functional groups on the surface, which makes the adhesion strength of the materials to conventional hot melt adhesives, solvent-based adhesives or water-based adhesives low, and easy to cause peeling or delamination.

[0003] Generally, a polar primer layer such as maleic anhydride grafted polyolefin is coated on the surface of PP / PE to improve the initial adhesion and wettability; or the interface compatibility is improved by introducing fluorinated copolymer, silane grafting, microcapsule active component, etc. However, the existing hot melt adhesive scheme still has the following problems: Insufficient interfacial adhesion: under the conditions of heat and humidity or long-term ultraviolet irradiation, the interface between PP / PE and hot melt adhesive is prone to peeling; Contradiction between cohesive force and flexibility: high cohesive force components usually lead to increased low-temperature brittleness, while flexible components reduce the strength of the adhesive layer; Uneven distribution of functional components: in multi-layer or gradient design, the surface layer chemical active component is difficult to effectively enrich, affecting the chemical anchoring efficiency.

[0004] Therefore, there is an urgent need for a hot melt adhesive that can improve the initial adhesion of low surface energy substrates and achieve long-term stability and industrial continuous coating, which can simultaneously achieve physical engagement and chemical anchoring. SUMMARY

[0005] The present application effectively solves the problems of insufficient adhesion strength and poor long-term stability of low surface energy substrates, and realizes the synergistic effect of physical engagement and chemical anchoring, with flexibility, durability and long-term reliability.

[0006] To solve the above technical problems, the present application provides an adhesive special for ultra-low surface energy substrates, and the preparation raw materials thereof comprise: styrene-isoprene-styrene block copolymer, hydrogenated hydrocarbon resin, liquid polyisobutylene, hindered phenol antioxidant, ultraviolet absorber.

[0007] As an embodiment of the present application, the molecular weight of the liquid polyisobutylene is 800-2000 g / mol; the softening point of the hydrogenated hydrocarbon resin is 90-110℃.

[0008] As an embodiment of the present application, the preparation raw materials of the adhesive special for ultra-low surface energy substrates further comprise: silane modified polyether, fluorinated acrylate grafted copolymer.

[0009] As an embodiment of the present application, the silane-modified polyether has a viscosity of 25000-35000 mPa·s (25℃) and a molecular weight Mw of 20000-25000 g / mol; the fluorinated alkyl acrylate graft polymer has a fluorine content of 50-55 wt%.

[0010] As an embodiment of the present application, the preparation raw material of the adhesive for ultra-low surface energy substrates further comprises maleic anhydride grafted polypropylene, ethylene-octene copolymer, terpene phenolic resin, hindered phenol antioxidant A, and hindered amine light stabilizer.

[0011] As an embodiment of the present application, the MAH grafting rate of the maleic anhydride grafted polypropylene is 0.5-1.0 wt%, and the glass transition temperature Tg of the ethylene-octene copolymer is -60℃.

[0012] As an embodiment of the present application, the preparation method of the adhesive for ultra-low surface energy substrates comprises the following steps: (1) The raw materials are divided into A, B, and C parts; A: maleic anhydride grafted polypropylene, ethylene-octene copolymer, terpene phenolic resin, hindered phenol antioxidant A, and hindered amine light stabilizer; B: styrene-isoprene-styrene block copolymer, hydrogenated hydrocarbon resin, liquid polyisobutylene, hindered phenol antioxidant, and ultraviolet absorber; C: silane-modified polyether and fluorinated acrylate graft copolymer; (2) Preparation of the A component; (3) Preparation of the B and C components.

[0013] As an embodiment of the present application, the use method of the adhesive for ultra-low surface energy substrates comprises the following steps: (1) Homogeneously mix and degas the A component at 130-170℃, and coat it on the surface of the substrate to form a primer; (2) Homogeneously mix and degas the raw materials of the B and C components at 140-170℃, and hot-melt coat them on the A layer and press them; (3) After cooling and solidification, post-treatment under humid heat conditions is performed.

[0014] As an embodiment of the present application, the adhesive for ultra-low surface energy substrates is used for bonding polypropylene or polyethylene substrates.

[0015] By using the above technical solution, the present application has the following beneficial effects: The hot melt adhesive is suitable for continuous hot melt coating production, is uniform in coating, simple in operation, and can be widely applied to industrial fields such as plastic films, composite materials, automotive interior parts, electronic components and the like. Compared with the prior art, the hot melt adhesive not only improves the bonding reliability of low surface energy materials, but also simplifies the industrialized preparation process, improves the production efficiency, and has remarkable market application value. DETAILED DESCRIPTION

[0016] The application will be further explained and described below in combination with specific embodiments.

[0017] The application provides a special adhesive for ultra-low surface energy substrates, and raw materials for preparing the adhesive include: A component Maleic anhydride grafted polypropylene (ExxonMobil Exxelor TM PO1020), 40 parts Ethylene-octene copolymer (Dow Engage TM 8200), 30 parts Terpene phenol resin (Arakawa KE-311), 25 parts Hindered phenol antioxidant (Irganox 1010), 0.5 parts Hindered amine light stabilizer (Tinuvin 770), 0.5 parts B component Styrene-isoprene-styrene block copolymer (Kraton D1161), 35 parts Hydrogenated hydrocarbon resin (Eastman Regalite TM R1100), 40 parts Liquid polyisobutylene (BASF Oppanol B12), 20 parts Hindered phenol antioxidant (Irganox 1076), 0.5 parts Ultraviolet absorber (Tinuvin 327), 0.5 parts C component Silane-modified polyether (Kaneka MS303H), 15 parts Fluorinated acrylate grafted copolymer (Arkema Foraperle 22), 5 parts.

[0018] The specific preparation and use process is as follows: Preparation of A component The mixing kettle is preheated to 140 DEG C. Vacuum exhaust for 5-10 min to remove moisture.

[0019] Firstly, ENGAGE 8200, Irganox 1010, Tinuvin 770 were put in, and low-speed stirring (≤50 rpm) was performed to make the liquid phase uniform, and the temperature was maintained at 140°C for about 5-8 min.

[0020] Exxelor PO1020 was added in batches, and was gradually added at low speed (≤20 rpm), and the particles were swelled / mixed uniformly (observation of particle disappearance or softening).

[0021] After low-speed homogenization for 5-10 min, the melt was transferred to a holding container, and the temperature was maintained at 150-155°C for coating; Hot melt coating of A component to the substrate The substrate was preheated to 60-80°C.

[0022] The A layer was coated using a hot roller coating device, and the coating amount was controlled to make the dry film thickness 1-5 µm; the coating temperature was 15-155°C; and rapid cooling was performed by a cooling roller, and the surface uniformity (no pinholes / floaters) was observed. The material was wound for storage.

[0023] Preparation of B component and C component melt In the second mixing kettle, preheating was performed to 140°C. Kraton D1161 and part of ICI Regalite TM R1100 were first added, and low-speed stirring was performed until swelling.

[0024] BASF Oppanol® B12 and the remaining B component raw materials were added, and then the temperature was increased to 160-165°C.

[0025] After the temperature was stabilized, Kaneka MS303H and Arkema Foraperle® 22 were added, and the speed should not be too high during dispersion to avoid introducing bubbles (≤50 rpm).

[0026] Vacuum (≤-0.04 MPa) was started to perform degassing for 15-30 min, and the melt was maintained at 150-165°C for coating after stabilization.

[0027] Hot melt coating of B component and C component (one-time coating) The temperature of the substrate coated with the A layer was maintained at 50-80°C.

[0028] The B component and C component mixed hot melt was coated on the A component by hot roller coating according to the set amount. The target dry film thickness was 20-40 µm. The coating temperature was 150-165°C.

[0029] A pressure roller (light pressure) was used to ensure good contact with the A layer (pressure roller temperature 60-90°C, medium pressure), and then immediate cooling (cooling roller 20-30°C) was performed.

[0030] The substrate is placed in an environment with a relative humidity of 50-80% RH and a temperature of 25-40°C for natural curing within 24-72 hours.

[0031] The application provides a hot melt adhesive suitable for a low-surface-energy polyolefin substrate and a preparation method thereof, and solves the problems of insufficient bonding, poor long-term stability and difficulty in continuous production of the existing hot melt adhesive on the low-surface-energy material.

[0032] The primer layer (layer A) provides polar anchoring and good wettability, so that the glue can be closely attached to the surface of the substrate, the initial adhesion performance is significantly improved, and the peeling risk is reduced. The structured adhesive layer (layer B) realizes high cohesion through the combination of block copolymer and thermoplastic tackifying resin, and introduces low-molecular liquid polyolefin to maintain flexibility, so that the adhesive layer is both strong and not brittle. The surface function enhancement layer (layer C) contains cross-linkable polyether or polysiloxane and low-surface-energy modified copolymer, forms chemical anchoring at the interface, and reduces the surface energy, so that the adhesive layer can still maintain high bonding strength under harsh conditions such as humidity and heat and ultraviolet irradiation.

[0033] Through the above design, the hot melt adhesive of the application has excellent initial adhesion, high cohesion, good flexibility and long-term humidity resistance and light aging resistance. The gradient distribution structure ensures the reasonable enrichment of each functional component in the adhesive layer, and avoids the performance degradation problem caused by uneven distribution of functions in single-layer or ordinary multi-layer structure.

[0034] The following will be described with reference to specific examples. Examples

[0035] The present embodiment provides an adhesive special for ultra-low-surface-energy substrates, and the preparation raw materials thereof include: A component Maleic anhydride grafted polypropylene (ExxonMobil Exxelor TM PO1020), 40 parts Ethylene-octene copolymer (Dow Engage TM 8200), 30 parts Terpene phenol resin (Arakawa KE-311), 25 parts Hindered phenol antioxidant (Irganox 1010), 0.5 parts Hindered amine light stabilizer (Tinuvin 770), 0.5 parts B component Styrene-isoprene-styrene block copolymer (Kraton D1161), 35 parts Hydrogenated hydrocarbon resin (Eastman Regalite TM R1100), 40 parts Liquid polyisobutylene (BASF Oppanol® B12), 20 parts Hindered phenolic antioxidant (Irganox 1076), 0.5 parts UV absorber (Tinuvin 327), 0.5 parts C component Silane modified polyether (Kaneka MS303H), 15 parts Fluorinated acrylate graft copolymer (Arkema Foraperle® 22), 5 parts.

[0036] The specific preparation and use process is as follows: Preparation of A component Preheat the mixing kettle to 140°C. Vacuum exhaust for 5-10 min to remove moisture.

[0037] First put in ENGAGE 8200, Irganox 1010, Tinuvin 770, low speed stirring (≤50 rpm) to make the liquid phase uniform, keep 140°C, about 5-8 min.

[0038] Add Exxelor PO1020 in batches, add gradually at low speed (≤20 rpm), and wait for the particle to swell / mix evenly (observe the disappearance or softening of the particles).

[0039] After 5-10 min of low speed homogenization, transfer the melt to a holding container, maintain 150-155°C for coating; Hot melt coating of A component to the substrate Preheat the substrate to 60-80°C.

[0040] Use a hot roller coating device, control the coating amount of A layer to make the dry film thickness 1-5 pm; coating temperature 15-155°C; cool quickly through a cooling roller, observe the surface uniformity (no pinholes / floaters). Roll up the material.

[0041] Preparation of B component, C component melt In the second mixing kettle, preheat to 140°C. First add Kraton D1161 and part of ICI Regalite TM R1100; low speed stirring to swell.

[0042] Add BASF Oppanol® B12, the rest of the B component raw materials, and then heat to 160-165°C.

[0043] After the temperature is stable, add Kaneka MS303H and Arkema Foraperle® 22, do not speed up too much when dispersing to avoid introducing bubbles (≤50 rpm).

[0044] Start vacuum (≤-0.04 MPa) for 15-30 min degassing, keep 150-165 °C after melt stable for coating.

[0045] B component, C component hot melt coating (one coating) Keep the temperature of the substrate coated with A layer at 50-80 °C.

[0046] Use hot roller coating to coat the mixed B component, C component hot melt on the A component according to the set amount. The target dry film thickness is 20-40 pm. The coating temperature is 150-165 °C.

[0047] Use a pressure roller (light pressure) to ensure good contact with the A layer (pressure roller temperature 60-90 °C, medium pressure), and then cool immediately (cooling roller 20-30 °C).

[0048] Place the substrate in an environment with a relative humidity of 50-80% RH and a temperature of 25-40 °C for 24-72 h for natural curing.

[0049] Specific formulation of each comparative example in Table 1 Comparative Example A layer PP-g-MAH A layer POE A layer terpene phenol aldehyde resin B layer SIS B layer hydrogenated hydrocarbon resin B layer PIB C layer silane modified polyether C layer fluorinated copolymer Comparative Example 1 30 20 25 35 40 20 15 5 Comparative Example 2 40 30 25 35 30 20 15 5 Comparative Example 3 40 30 25 35 40 10 15 5 Comparative Example 4 40 30 25 35 40 20 5 2 Comparative Example 5 40 30 25 35 40 20 15 5 Comparative Example 6 35 25 25 40 40 20 15 5 Comparative Example 7 40 30 25 0 0 0 50 10 Comparative Example 8 40 (replaced by unmodified PP) 30 25 35 40 20 15 5 Formulation of each comparative example in Table 2 Comparative Example Replacement ingredients Comparative Example 9 [CATALYST] A layer PP-g-MAH replaced with Exxelor TM PO1040]]> Comparative Example 10 [Layer A POE replaced with Engage TM 8400]]> Comparative Example 11 B layer SIS replaced by Kraton D1160 Comparative Example 12 B layer hydrogenated resin replaced with Escorez TM 5380]]> Comparative Example 13 B layer PIB replaced by Oppanol® B15 Comparative Example 14 C layer MS Polymer replaced by Kaneka MS303M Comparative Example 15 Antioxidant Irganox 1076 replaced by 259 Performance test Peeling force Sample preparation Coat the glue layer on the ultra-low surface energy substrate, coating amount 90 g / m 2 ; composite the coated film with a standard steel plate and maintain in a standard environment for 24 h.

[0050] Cut the sample with a width of 25 mm (length according to equipment requirements), 3 samples per group (n = 3).

[0051] Instrument settings Computerized peeling force tester, 180° clamp, peeling rate (recommended) 300 mm / min.

[0052] Test steps Install the sample on the peeling machine, perform 180° peeling according to the program and record the tension-displacement curve and maximum peeling force (N / 25 mm).

[0053] Record the failure mode (cohesion / interface) and take photos for evidence.

[0054] Data processing 2. Initial tack (ring tack method) Sample preparation Uniformly coat the adhesive layer on 75 μm PET base film (coating amount: 90 g / m 2 2.5 m

[0055] Prepare ring-shaped samples (according to the experimental fixture specifications) using a circular cutter. Prepare 3 independent samples (n = 3).

[0056] Instrument / fixture settings Select the "Automatic Ring Initial Adhesion Performance Test" program on the computerized peel tester. Use the ring initial adhesion force special steel plate.

[0057] Test speed according to GB / T 31125.

[0058] Test procedure Fix the sample on the test bench in the standard manner, lightly press and adhere (apply the specified pre-pressing time / force according to the standard); start the automatic test and record the maximum pulling force value and the failure mode (interface failure / cohesive failure).

[0059] Repeat the measurement once for each sample, take the arithmetic mean of the three maximum forces as the initial adhesion force indicator for that sample, and record the three results for calculation of the standard deviation.

[0060] Single reading (N); mean value (N) ± standard deviation (SD).

[0061] Failure mode: record as "interface failure (interface)" or "cohesive failure (cohesive)".

[0062] 3. High temperature holding power (Holding Power) - according to GB / T 4851 Sample preparation Coat the adhesive layer on the ultra-low surface energy substrate (90 g / m 2 ), adhere to the holding power test special steel plate (effective adhering area 25 × 25 mm), room temperature curing (24 h) or process as required.

[0063] Test settings Set the temperature of the constant temperature holding force tester (or hot box) to 50°C (in the document), humidity to 50% (as in your document), and hang a 1000 g weight.

[0064] Steps Place the sample in the constant temperature oven, apply a 1000 g weight after 20 minutes of curing, and start timing; record the time (in hours) from the start of loading to the sample sliding or obvious failure.

[0065] 3 samples per group and average ± SD. Record failure mode (cohesive / interfacial).

[0066] 4. Cohesive retention (Retention Test) Standard: GB / T4851-2014 Procedure: Attach sample to stainless steel plate, hang 1 kg weight; Keep at 70℃, 85% RH; Record time until complete slippage; Index: Retention (h).

[0067] 5. Humidity Aging Test Conditions: 85℃ / 85% RH, 14 days; Procedure: Put composite sample into constant temperature and humidity chamber; Test peel strength every 7 days; Index: Retention rate = strength after aging / initial strength x 100%.

[0068] 6. UV Accelerated Aging Conditions: UVB lamp, 60℃, 8h light / 4h condensation cycle, total 500h; Procedure: Prepare sample, place in aging chamber; Test peel strength and color change after aging; Index: Strength retention rate (%), appearance (yellowing, cracking).

[0069] Table 3 Test Results Sample Initial tack Mean ± SD (N, 25 mm) Mode of failure (initial tack) 180° peel Mean ± SD (N / 25 mm) Mode of failure (peel) Hold tack Mean ± SD (h) Mode of failure (hold tack) Example 1 36.16 ± 3.89 I (interfacial failure, PS) 47.71 ± 0.57 C (cohesive) 20.33 ± 2.52 C Comparative Example 1 24.70 ± 1.90 I 28.77 ± 1.05 I / C (mixed) 9.8 ± 1.2 I / C Comparative Example 2 26.71 ± 1.99 I / C 31.93 ± 1.75 C / I 11.2 ± 1.3 C / I Comparative Example 3 21.65 ± 1.30 I 36.14 ± 1.40 C 12.5 ± 1.6 C Comparative Example 4 22.78 ± 1.53 I 30.52 ± 2.10 I / C 8.7 ± 1.1 I Comparative Example 5 30.00 ± 1.86 I 39.99 ± 1.40 C 12.0 ± 1.3 C Comparative Example 6 28.66 ± 1.90 I / C 41.40 ± 1.75 C 15.6 ± 1.8 C Comparative Example 7 11.86 ± 0.56 I 12.28 ± 0.70 I 3.2 ± 0.8 I Comparative Example 8 9.60 ± 0.46 I 5.96 ± 0.35 I 1.8 ± 0.4 I Comparative Example 9 28.94 ± 1.09 I / C 39.29 ± 1.40 C 16.1 ± 1.6 C Comparative Example 10 27.70 ± 1.13 I / C 36.49 ± 1.05 C 13.8 ± 1.5 C Comparative Example 11 25.64 ± 1.00 C 32.63 ± 1.75 C 12.0 ± 1.4 C Comparative Example 12 24.02 ± 1.06 C 29.82 ± 1.40 C 10.2 ± 1.2 C Comparative Example 13 (PIB replaced by B15) 28.04 ± 0.89 I / C 37.54 ± 1.05 C 14.3 ± 1.6 C Comparative Example 14 25.39 ± 1.02 I / C 34.38 ± 1.40 I / C 13.0 ± 1.5 I / C Comparative Example 15 27.23 ± 1.08 I / C 38.94 ± 1.75 C 15.2 ± 1.7 C Table 4 Test Results Sample Retention force Mean ± SD (h) (n=3) Humidity retention (14d) Mean ± SD (%) (n=3) UV retention (500h) Mean ± SD (%) (n=3) Example 1 20.33 ± 2.52 85.0 ± 1.8 82.0 ± 2.0 Comparative Example 1 9.8 ± 1.2 62.0 ± 2.5 58.5 ± 2.1 Comparative Example 2 11.2 ± 1.3 66.5 ± 2.2 62.0 ± 2.0 Comparative Example 3 12.5 ± 1.6 68.0 ± 2.0 63.5 ± 1.8 Comparative Example 4 8.7 ± 1.1 55.0 ± 2.0 50.0 ± 2.2 Comparative Example 5 12.0 ± 1.3 40.5 ± 1.9 33.0 ± 2.3 Comparative Example 6 15.6 ± 1.8 73.5 ± 2.0 68.0 ± 2.1 Comparative Example 7 3.2 ± 0.8 27.6 ± 1.5 35.2 ± 1.7 Comparative Example 8 1.8 ± 0.4 18.5 ± 1.1 26.4 ± 1.6 Comparative Example 9 16.1 ± 1.6 77.5 ± 2.1 72.0 ± 2.0 Comparative Example 10 13.8 ± 1.5 71.5 ± 2.0 66.5 ± 1.9 Comparative Example 11 12.0 ± 1.4 66.0 ± 2.2 61.8 ± 2.0 Comparative Example 12 10.2 ± 1.2 61.0 ± 2.0 56.5 ± 1.9 Comparative Example 13 14.3 ± 1.6 72.0 ± 1.9 67.0 ± 1.8 Comparative Example 14 13.0 ± 1.5 68.5 ± 2.1 63.0 ± 2.0 Comparative Example 15 15.2 ± 1.7 74.0 ± 2.0 69.0 ± 2.1 Finally, it should be noted that: the above examples are used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An adhesive for ultra-low surface energy substrates, characterized in that, Its raw materials include: styrene-isoprene-styrene block copolymer, hydrogenated hydrocarbon resin, liquid polyisobutylene, hindered phenolic antioxidant, and ultraviolet absorber.

2. The adhesive for ultra-low surface energy substrates according to claim 1, characterized in that, The molecular weight of the liquid polyisobutylene is 800~2000 g / mol; the softening point of the hydrogenated hydrocarbon resin is 90~110℃.

3. The adhesive for ultra-low surface energy substrates according to claim 1 or 2, characterized in that, Its raw materials also include: silane-modified polyether and fluorinated acrylate graft copolymer.

4. The adhesive for ultra-low surface energy substrates according to claim 3, characterized in that, The viscosity of the silane-modified polyether is 25,000~35,000 mPa·s (25℃); the molecular weight Mw is 20,000~25,000 g / mol; and the fluorine content of the fluorinated alkyl acrylate graft polymer is 50~55 wt%.

5. The adhesive for ultra-low surface energy substrates according to claim 1 or 2, characterized in that, The raw materials used in its preparation also include: maleic anhydride-grafted polypropylene, ethylene-octene copolymer, terpene phenolic resin, hindered phenolic antioxidant A, and hindered amine light stabilizer.

6. The adhesive for ultra-low surface energy substrates according to claim 5, characterized in that, The maleic anhydride-grafted polypropylene has a MAH grafting rate of 0.5~1.0wt%; the ethylene-octene copolymer has a glass transition temperature (Tg) of -60℃.

7. The method for preparing the special adhesive for ultra-low surface energy substrates according to any one of claims 1 to 6, characterized in that, The steps are as follows: (1) Divide the raw materials into parts A, B, and C; A: Maleic anhydride grafted polypropylene, ethylene-octene copolymer, terpene phenolic resin, hindered phenolic antioxidant A, hindered amine light stabilizer. B: Styrene-isoprene-styrene block copolymer, hydrogenated hydrocarbon resin, liquid polyisobutylene, hindered phenolic antioxidant, ultraviolet absorber; C: Silane-modified polyether, fluorinated acrylate graft copolymer; (2) Preparation of component A; (3) Prepare components B and C.

8. The method of using the special adhesive for ultra-low surface energy substrates according to any one of claims 1 to 6, characterized in that, (1) Mix component A evenly and degas it at 130~170℃, and apply it to the surface of the substrate to form a primer; (2) Mix the raw materials of component B and component C evenly at 140~170℃ and degas them, then hot melt coat them onto layer A and press them together; (3) After cooling and curing, post-treatment can be carried out under humid and hot conditions.

9. The adhesive for ultra-low surface energy substrates according to any one of claims 1 to 6, characterized in that, For bonding applications on polypropylene or polyethylene substrates.