High-temperature-resistant hot-melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant hot-melt pressure-sensitive adhesive based on SBR (Styrene Butadiene Rubber) and SBS (Styrene Butadiene Styrene) high-temperature thermal crosslinking and a preparation method thereof, and belongs to the technical field of hot-melt pressure-sensitive adhesives. The high-temperature-resistant hot-melt pressure-sensitive adhesive comprises the following components in parts by weight: 20-40 parts of SBR; 15 to 30 parts of SBS (styrene butadiene styrene); 30 to 50 parts of tackifying resin; 5 to 15 parts of a softening agent; and 0.5 to 2 parts of an antioxidant. According to the invention, through a specific polymer combination, a thermal cross-linking reaction is carried out at a high temperature, so that the high-temperature resistance is remarkably improved, and meanwhile, good flexibility and adhesive power to a plurality of substrates are kept. According to the invention, the convenient coating process of the hot-melt pressure-sensitive adhesive is maintained, the temperature resistance limit of the traditional product is broken through, and the adhesive has obvious application advantages in the scenes of new energy automobile battery pack fixation, engine compartment wire harness binding and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of hot melt pressure - sensitive adhesives, and specifically relates to a high - temperature resistant hot melt pressure - sensitive adhesive based on SBR and SBS high - temperature thermal cross - linking and a preparation method thereof. Background Art

[0002] The hot melt pressure - sensitive adhesives used in wire harness tapes on the current market have certain limitations in high - temperature resistance performance. In some high - temperature environments, such as inside electronic devices, around automotive engines, etc., the existing hot melt pressure - sensitive adhesives may exhibit problems such as decreased viscosity, flow, and debonding, resulting in the failure of functions such as tape fixation and sealing, and affecting the normal use and stability of products.

[0003] Most of the existing high - temperature resistant hot melt pressure - sensitive adhesives improve their high - temperature resistance by adding specific high - temperature resistant resins or inorganic fillers, but these methods often bring other problems, such as increasing costs, reducing the flexibility of the adhesive, and affecting its adhesion to different substrates. For example: 1) Existing high - temperature resistant modification schemes (such as introducing acrylate, epoxy resin, etc.) often lead to loss of initial tack or process complexity; 2) When improving the heat resistance through chemical cross - linkers (peroxides, isocyanates, etc.), there are problems such as poor storage stability and uncontrollable cross - linking speed. At the same time, the existing technologies do not fully utilize the special reactions between polymers to enhance the high - temperature resistance performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a high - temperature resistant hot melt pressure - sensitive adhesive based on SBR and SBS high - temperature thermal cross - linking and a preparation method thereof. Through a specific polymer combination, a thermal cross - linking reaction occurs at high temperatures, thereby significantly improving the high - temperature resistance performance, while maintaining good flexibility and adhesion to a variety of substrates.

[0005] The purpose of the present invention can be achieved through the following technical solutions: 1. It is found that SBR and SBS can undergo a self - cross - linking reaction in a specific temperature range (120 - 180 °C) to form a three - dimensional network structure; 2. Using the dynamic thermal cross - linking mechanism, the high - temperature holding tack and the initial tack retention rate are simultaneously improved without adding external cross - linkers; 3. By adjusting the SBR / SBS ratio and optimizing the auxiliary components, the heat resistance and processing performance are balanced.

[0006] Specifically, a high - temperature resistant hot melt pressure - sensitive adhesive based on SBR and SBS high - temperature thermal cross - linking, by weight, comprises the following components: SBR: 20 - 40 parts; SBS: 15 - 30 parts; Tackifying resin: 30 - 50 parts; Softening agent: 5 - 15 parts; Antioxidant: 0.5 - 2 parts.

[0007] Further, the SBR is preferably solution-polymerized SBR, and the mass content of styrene is 25 - 40%.

[0008] Further, the SBS has a star structure, and the styrene / butadiene ratio is 30 / 70 (mass ratio).

[0009] Further, the mass ratio of SBR / SBS is 3:2.

[0010] Further, the tackifying resin is a composite system of C5 / C9 copolymer resin + hydrogenated rosin ester.

[0011] Further, the softening agent is naphthenic oil.

[0012] Further, the antioxidant is a compound of hindered phenol and phosphite.

[0013] The preparation method of the high-temperature resistant hot melt pressure-sensitive adhesive includes the following steps: Step 1: Raw material preparation: Accurately weigh SBR, SBS, tackifying resin, softening agent and antioxidant according to the above weight parts.

[0014] Step 2: Mixing and melting: Add SBR, SBS, softening agent and antioxidant into the reaction kettle, heat up to 150 - 180 °C, and fully melt and mix them under stirring conditions.

[0015] Step 3: Adding tackifying resin: After SBR, SBS, softening agent and antioxidant are mixed evenly, lower the temperature to 120 - 140 °C, add tackifying resin and antioxidant, and continue stirring to fully mix all components.

[0016] Step 4: Discharging: After stirring is completed, filter the hot melt pressure-sensitive adhesive in the reaction kettle through a filter screen to remove possible impurities, and then discharge it to obtain the high-temperature resistant hot melt pressure-sensitive adhesive.

[0017] Further, in Step 2, the stirring speed is 100 - 300 r / min, and the stirring time is 30 - 60 minutes.

[0018] Further, the continuous stirring time in Step 3 is 30 - 60 minutes.

[0019] The above scheme has the following advantages: Unique self-crosslinking reaction: It has been found that SBR and SBS can undergo a self-crosslinking reaction within a specific temperature range of 120 - 180°C. During melt processing (140 - 160°C) and subsequent use, the butadiene segments of SBR and the polybutadiene blocks of SBS undergo a free radical crosslinking reaction under thermal activation, thereby forming a three-dimensional network structure and an interpenetrating network structure (IPN).

[0020] Performance improvement based on dynamic thermal crosslinking: With this dynamic thermal crosslinking mechanism, it is possible to simultaneously improve the high-temperature holding tack and the initial tack retention rate of the material without adding external crosslinking agents. At the same time, by adjusting the ratio of SBR / SBS and optimizing the auxiliary components, the balance between heat resistance and processing performance can also be achieved. It is worth mentioning that the appropriate ratio of SBR to SBS is 3:2. At this time, the crosslinking density can be effectively controlled, enabling the material to maintain elasticity at high temperatures and avoid rigid fracture.

[0021] Advantages of the present invention: The present invention realizes the "adaptive crosslinking" of materials at high temperatures through molecular design, which not only maintains the convenient coating process of hot melt pressure-sensitive adhesives but also breaks through the temperature resistance limit of traditional products. It has significant application advantages in scenarios such as the fixation of new energy vehicle battery packs and the bundling of engine compartment wiring harnesses. Specifically, it has the following key features: Thermal crosslinking trigger mechanism: During melt processing (140 - 160°C) and subsequent use, the butadiene segments of SBR and the polybutadiene blocks of SBS undergo a free radical crosslinking reaction under thermal activation to form an interpenetrating network structure (IPN), significantly enhancing the high-temperature cohesive strength. Synergistic tackifying system: The use of a composite of hydrogenated rosin ester and C5 / C9 resin maintains the compatibility of the tackifying resin at high temperatures and avoids performance degradation caused by phase separation. Dynamic crosslinking control: By selecting the ratio of SBR / SBS (preferably 3:2) and the type of softener, the crosslinking density is regulated to enable the material to maintain elasticity rather than rigid fracture at high temperatures. Detailed implementation manners

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0023] The hot melt pressure-sensitive adhesives in the following examples and comparative examples were prepared according to the following process: Step 1: Raw material preparation: Accurately weigh SBR, SBS, tackifying resin, softener, and antioxidant according to parts by weight.

[0024] Step 2: Mixing and melting: Add SBR, SBS, softener, and antioxidant into the reaction kettle, heat up to 150 - 180 °C, and make them fully melt and mix under stirring conditions. The stirring speed is 100 - 300 r / min, and the stirring time is 30 - 60 minutes.

[0025] Step 3: Adding tackifying resin: After the SBR, SBS, softener, and antioxidant are mixed evenly, lower the temperature to 120 - 140 °C, add the tackifying resin and antioxidant, and continue stirring for 30 - 60 minutes to make all components fully mixed.

[0026] Step 4: Discharging: After stirring is completed, filter the hot melt pressure - sensitive adhesive in the reaction kettle through a filter screen to remove possible impurities, and then discharge it to obtain the high - temperature - resistant hot melt pressure - sensitive adhesive of the present invention.

[0027] The SBR (styrene 35%) used in the following examples and comparative examples is 2605 from Sinopec; the C5 / C9 copolymer resin is 1288 from Henghe Resin; the hydrogenated DCPD petroleum resin is HD1100 from Henghe Resin.

[0028] Example 1: Formula of high - temperature - resistant hot melt pressure - sensitive adhesive: SBR (styrene 35%): 30 parts SBS (YH - 791): 20 parts C5 / C9 copolymer resin (tackifying resin): 10 parts Hydrogenated DCPD petroleum resin (tackifying resin): 30 parts Naphthenic oil (KN4010, softener): 10 parts Antioxidant 1010 / 168 (mass ratio of the two is 1:1): 0.3 part Example 2: Upper limit extreme value: SBR (styrene 35%): 40 parts SBS (YH - 791): 10 parts C5 / C9 copolymer resin (tackifying resin): 10 parts Hydrogenated DCPD petroleum resin (tackifying resin): 30 parts Naphthenic oil (KN4010, softener): 10 parts Antioxidant 1010 / 168 (mass ratio of the two is 1:1): 0.3 part Example 3: SBR (styrene 35%): 10 parts SBS (YH - 791): 40 parts C5 / C9 copolymer resin (tackifying resin): 10 parts Hydrogenated DCPD petroleum resin (tackifying resin): 30 parts Naphthenic oil (KN4010, plasticizer): 10 parts Antioxidant 1010 / 168 (mass ratio of the two is 1:1): 0.3 parts Comparative Example 1: Traditional hot melt pressure sensitive adhesive formulation: SIS: 25 parts SBS: 25 parts C5 / C9 copolymer resin (tackifying resin): 15 parts Hydrogenated DCPD petroleum resin (tackifying resin): 25 parts Naphthenic oil (KN4010, plasticizer): 10 parts Antioxidant 1010 / 168 (mass ratio of the two is 1:1): 0.3 parts Comparative Example 2: Traditional hot melt pressure sensitive adhesive formulation: SBR (styrene 35%): 15 parts SBS (YH-791): 15 parts SIS: 20 parts C5 / C9 copolymer resin (tackifying resin): 25 parts Modified epoxy resin (tackifying resin): 15 parts Naphthenic oil (KN4010, plasticizer): 10 parts Antioxidant 1010 / 168 (mass ratio of the two is 1:1): 0.3 parts The following performance tests were carried out on the above Example 1, Comparative Example 1 and Comparative Example 2. The test methods are shown in Table 1, and the specific test data are shown in Table 2:

[0029]

[0030] The above content is only an example and illustration of the present invention. Those skilled in the art of this technology can make various modifications or supplements or use similar methods to replace the specific embodiments described. As long as they do not deviate from the invention or exceed the scope defined by the claims of this patent, they should fall within the protection scope of the present invention.

Claims

1. A high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking, characterized in that, By weight, it comprises the following components: SBR: 20 - 40 parts; SBS: 15 - 30 parts; Tackifying resin: 30 - 50 parts; Softening agent: 5 - 15 parts; Antioxidant: 0.5 - 2 parts.

2. The high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, characterized in that The SBR is solution-polymerized SBR with a styrene content of 25 - 40%.

3. A high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, characterized in that, The SBS has a star structure with a styrene / butadiene ratio of 30 / 70.

4. An anti-high temperature hot melt pressure-sensitive adhesive based on SBR and SBS high temperature thermal crosslinking according to claim 1, characterized in that, The mass ratio of SBR / SBS is 3:

2.

5. A high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, characterized in that, The tackifying resin is a composite system of C5 / C9 copolymer resin + hydrogenated rosin ester.

6. The high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, wherein, The softening agent is naphthenic oil.

7. A high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, characterized in that, The antioxidant is a compound of hindered phenol and phosphite.

8. The preparation method of a high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, characterized in that, It includes the following steps: Step 1: Raw material preparation: Accurately weigh SBR, SBS, tackifying resin, softening agent and antioxidant according to the weight parts; Step 2: Mixing and melting: Add SBR, SBS, softening agent and antioxidant into the reaction kettle, heat up to 150 - 180 °C, and make them fully melt and mix under stirring conditions; Step 3: Adding tackifying resin: After SBR, SBS, softening agent and antioxidant are mixed evenly, lower the temperature to 120 - 140 °C, add the tackifying resin, and continue stirring to make all components fully mixed; Step 4: Discharging: After stirring is completed, filter the hot melt pressure-sensitive adhesive in the reaction kettle through a filter screen, and then discharge it to obtain the high-temperature resistant hot melt pressure-sensitive adhesive.

9. The preparation method of a high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 8, characterized in that, In Step 2, the stirring speed is 100 - 300 r / min, and the stirring time is 30 - 60 minutes.

10. The preparation method of a high-temperature resistant hot melt pressure-sensitive adhesive based on SBR and SBS high-temperature thermal crosslinking according to claim 1, characterized in that, In Step 3, the continuous stirring time is 30 - 60 minutes.

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