A silicone-modified butadiene and styrene copolymer, and a method of making and use thereof
By introducing reactive silanes into butadiene-styrene copolymers, molecular chemical cross-linking is achieved, solving the problem of insufficient strength of traditional copolymers and improving the bonding strength and ease of application of adhesives.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2024-12-25
- Publication Date
- 2026-05-19
AI Technical Summary
When traditional butadiene/styrene copolymers are used as adhesives, insufficient chemical cross-linking results in limited strength, which cannot meet the demanding application requirements. Existing technologies mostly improve the bonding strength by optimizing the formulation rather than by designing the molecular structure.
By introducing reactive silanes into the polymer network and achieving molecular chemical crosslinking through the action of catalysts and water vapor, organosilicon-modified butadiene and styrene copolymers are prepared, giving them self-curing capabilities.
Chemical cross-linking of polymers is achieved at room temperature, which improves the strength and ease of application of the adhesive and meets the demanding application requirements.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to a butadiene-styrene copolymer, and more particularly to an organosilicon-modified butadiene-styrene copolymer, its preparation method, and its application. Background Technology
[0002] Butadiene and styrene are common chemical raw materials. Polymers synthesized from them, such as styrene-butadiene rubber (SBS), are widely used in tires, plastic modification, and adhesives, achieving good market feedback. Traditionally, butadiene / styrene copolymers used as adhesives require compounding with tackifying resins, fillers, and other auxiliary materials to achieve a certain bond strength. This traditional combination, lacking chemical cross-linking, results in limited inherent colloid strength, making it unsuitable for increasingly demanding application requirements.
[0003] For example, patent CN101622323B optimizes the adhesive strength and application range of the formulated adhesive product by optimizing the adhesive formulation based on SBS resin, but does not mention the method of modifying the polymer structure to improve the adhesive strength.
[0004] The same patent, CN 115260952B, improves the weather resistance and adhesion of adhesives by optimizing the formulation of butadiene / styrene copolymer-based resins. However, it does not mention any method to improve adhesive performance through resin molecular structure design.
[0005] In summary, the industry generally adopts formulation optimization to improve the performance of adhesive products based on butadiene / styrene polymers, but there are no reports of molecular structure design to significantly improve their performance for specific applications. Summary of the Invention
[0006] To address the aforementioned technical problems, this invention proposes an organosilicon-modified butadiene-styrene copolymer and its preparation method. This invention innovatively introduces reactive silanes into the polymer network, enabling it to possess self-curing capabilities. Under the action of a catalyst and water vapor, chemical cross-linking of the molecules can be achieved, resulting in improved strength.
[0007] The organosilicon-modified butadiene-styrene copolymer of the present invention can be moisture-cured at room temperature, has a simple process, and can be used as an adhesive.
[0008] In a first aspect, the present invention provides a method for preparing an organosilicon-modified butadiene-styrene copolymer, comprising the following steps:
[0009] 1) Styrene, butadiene, catalyst A, and organic solvent are mixed to carry out the first stage polymerization reaction, and then styrene is added to continue the second stage polymerization reaction;
[0010] 2) Add a silane coupling agent to the system in step 1) to carry out a coupling reaction;
[0011] 3) Add vinylsilane coupling agent and catalyst B to the system in step 2) to react and obtain the organosilicon-modified butadiene and styrene copolymer.
[0012] As a preferred embodiment of the present invention, the total amount of styrene used in step 1) is 10-31% of the mass of butadiene, for example, 10%, 13%, 15%, 18%, 20%, 22%, 25%, 28%, 31%, etc., preferably 15-20%;
[0013] Preferably, the added styrene is 1.6-10 wt% of the total styrene content, such as 1.6%, 2%, 3%, 5%, 7%, 9%, 10%, etc., and more preferably 5-8 wt%.
[0014] As a preferred embodiment of the present invention, the catalyst A in step 1) is selected from organolithium compounds, preferably one or more of methyllithium, ethyllithium, tert-butyllithium, n-butyllithium, sec-butyllithium, trimethylsilyllithium, and phenyllithium. In practical applications, the catalyst A can be used directly in pure form or dissolved in an organic solvent. The present invention does not have any special requirements.
[0015] Preferably, the amount of catalyst A is 1-4% of the total mass of the polymeric monomers, such as 1%, 2%, 3%, 4%, etc., preferably 2-3%, and the polymeric monomers include styrene and butadiene.
[0016] As a preferred embodiment of the present invention, the organic solvent in step 1) can be a conventional organic solvent in the field, preferably one or more of cyclohexane, n-hexane, toluene, tetrahydrofuran, and n-heptane;
[0017] Preferably, the amount of organic solvent used is 1-20 times the total mass of the polymeric monomers, for example, 1, 3, 5, 8, 10, 12, 15, 18, 20 times, etc., preferably 5-15 times, and the polymeric monomers include styrene and butadiene.
[0018] As a preferred embodiment of the present invention, the polymerization reaction in step 1) is carried out at a temperature of 30-90°C, for example, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, etc.
[0019] Preferably, the conversion rate is tested during the first stage of the polymerization reaction. After the styrene monomer conversion rate rises to over 98%, styrene is added to continue the second stage of the polymerization reaction.
[0020] Preferably, the first stage polymerization reaction time is 30-120 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, etc., and the second stage polymerization reaction time after adding styrene is 30-120 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, etc.
[0021] As a preferred embodiment of the present invention, the silane coupling agent in step 2) is selected from chlorosilanes and alkoxysilanes, preferably one or a mixture of tetrachlorosilane, methyltrichlorosilane, dimethyldichlorosilane, tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane.
[0022] Preferably, the amount of the silane coupling agent is 0.01-0.1% of the mass of the polymerizing monomer in step 1), for example, 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, etc., preferably 0.03-0.08%, wherein the polymerizing monomer includes styrene and butadiene;
[0023] As a preferred embodiment of the present invention, the coupling reaction in step 2) is carried out at a temperature of 30-60°C, such as 30°C, 40°C, 50°C, 60°C, etc., and for a time of 30-120 min, such as 30 min, 50 min, 80 min, 100 min, 120 min, etc.
[0024] As a preferred embodiment of the present invention, the vinyl silane coupling agent in step 3) is selected from vinylalkoxysilane, preferably one or a mixture of vinyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, and methylvinyldiethoxysilane;
[0025] Preferably, the amount of vinylsilane used is 1-7% of the mass of the polymerizing monomer in step 1), such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, etc., preferably 3-5%, and the polymerizing monomer includes styrene and butadiene;
[0026] As a preferred embodiment of the present invention, the catalyst B in step 3) is selected from common free radical initiators in the field, preferably one or a mixture of benzoyl peroxide, azobisisobutyronitrile, and dimethyl azobisisobutyrate;
[0027] Preferably, the amount of catalyst B is 0.1-2% of the mass of the polymerizing monomer in step 1), for example, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.8%, 2%, etc., preferably 0.5-1.5%, and the polymerizing monomer includes styrene and butadiene;
[0028] As a preferred embodiment of the present invention, the reaction in step 3) is carried out at a temperature of 80-120°C, such as 80°C, 90°C, 100°C, 110°C, 120°C, etc., and for a time of 60-180 min, such as 60 min, 80 min, 100 min, 120 min, 150 min, 180 min, etc.
[0029] As a preferred embodiment of the present invention, conventional additives in the field, such as antioxidants, are also added to the system in step 3).
[0030] Preferably, the antioxidant is a free radical scavenging antioxidant, and more preferably one or a mixture of 2,6-di-tert-butyl-p-methylphenol (BHT), octadecyl alcohol di-T-butyl-4-hydroxyhydrocinnamate (antioxidant 1076), and pentaerythritol tetra(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (antioxidant 1010);
[0031] Preferably, the amount of antioxidant is 0.1-2% of the mass of the polymeric monomer in step 1), such as 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.8%, 2%, etc., preferably 0.5-1.5%, and the polymeric monomer includes styrene and butadiene.
[0032] Secondly, the present invention provides an organosilicon-modified butadiene-styrene copolymer, which is prepared by the method described above.
[0033] The polymer described in this invention is an organosilicon-modified star-shaped butadiene and styrene copolymer with a number average molecular weight of 5,000-30,000 and contains siloxane groups that can be moisture-cured.
[0034] Thirdly, the present invention also provides an application of the organosilicon-modified butadiene-styrene copolymer prepared by the method described above as an adhesive, particularly as a waterproof sealing adhesive.
[0035] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:
[0036] This invention involves synthesizing a butadiene-styrene copolymer and then modifying it with a silane coupling agent. It innovatively introduces reactive silanes into the polymer network, giving it self-curing capabilities. Under the action of a catalyst and moisture, the molecules can achieve chemical cross-linking, resulting in improved strength. Furthermore, this copolymer can cure at room temperature, providing more convenient construction conditions. Detailed Implementation
[0037] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.
[0038] Unless otherwise specified, the raw materials and reagents used in the embodiments of this invention can be purchased commercially.
[0039] The main testing methods involved in the embodiments of this invention are as follows:
[0040] Molecular weight and distribution (PDI) test method: The test was performed using Agilent PL-GPC-50 gel chromatography with tetrahydrofuran as the mobile phase;
[0041] Adhesion strength test (i.e. aluminum sheet shear strength): The test was conducted using a universal testing machine AI-7000S / MU in shear mode. The test sample was an anodized aluminum sheet.
[0042] Tensile strength: Tested using a universal testing machine AI-7000S / MU, in accordance with national standard GB / T 528-2009;
[0043] Elongation at break: Tested using a universal testing machine AI-7000S / MU, in accordance with national standard GB / T 528-2009;
[0044] Anti-aging test method: Tensile strength and elongation at break are tested after aging in a constant temperature and humidity chamber at 85 for 72 hours.
[0045] Conversion rate testing method: The residual monomer content was tested using an Agilent 8860 gas chromatograph, and the conversion rate was calculated.
[0046] Example 1
[0047] 300g of cyclohexane, 12g of styrene, and 48g of butadiene were added to a 1-liter pressure-resistant reactor and mixed thoroughly. The mixture was heated to 50°C, and 1.2g of 1.6mol / L n-butyl catalyst was added. After reacting for 60 minutes, the styrene conversion rate was tested and found to be 99.4%. 0.2g of styrene was added, and the reaction was continued for another 60 minutes.
[0048] Add 0.02 g of tetrachlorosilane and continue the reaction at 50 °C for 30 min.
[0049] Add 2g of vinyltriethoxysilane and 0.9g of benzoyl oxidase catalyst, react at 100℃ for 60min, cool to room temperature, add 0.6g of antioxidant BHT, stir evenly, and obtain organosilicon-modified butadiene and styrene copolymer.
[0050] The molecular weight and its distribution were tested, as shown in Table 1.
[0051] Example 2
[0052] 300g of cyclohexane, 100g of n-hexane, 10g of styrene, and 50g of butadiene were added to a 1-liter pressure-resistant reactor and mixed thoroughly. The mixture was heated to 50°C, and 1.4g of 1.6mol / L n-butyl catalyst was added. After reacting for 45 minutes, the styrene conversion rate was tested and found to be 99.1%. 0.25g of styrene was added, and the reaction was continued for another 60 minutes.
[0053] Add 0.03 g of tetrachlorosilane and continue the reaction at 50 °C for 30 min.
[0054] Add 1g of vinyltriethoxysilane and 0.9g of benzoyl oxidase catalyst, react at 100℃ for 60min, cool to room temperature, add 0.8g of antioxidant BHT, stir evenly, and obtain organosilicon-modified butadiene and styrene copolymer.
[0055] The molecular weight and its distribution were tested, as shown in Table 1.
[0056] Example 3
[0057] 500g of n-hexane, 100g of tetrahydrofuran, 8g of styrene, and 52g of butadiene were added to a 1-liter pressure-resistant reactor and mixed thoroughly. The mixture was heated to 70°C, and 1.6g of 1.6mol / L n-butyl catalyst was added. After reacting for 90 minutes, the styrene conversion rate was tested and found to be 99.5%. 0.5g of styrene was added, and the reaction was continued for another 60 minutes.
[0058] Add 0.04 g of methyltrichlorosilane and continue the reaction at 60 °C for 30 min.
[0059] Add 1.5g of vinyltrimethoxysilane and 0.6g of benzoyl oxidase catalyst, react at 110℃ for 60min, then cool to room temperature, add 0.9g of antioxidant 1076, stir evenly, and obtain organosilicon-modified butadiene and styrene copolymer.
[0060] The molecular weight and its distribution were tested, as shown in Table 1.
[0061] Example 4
[0062] 800g of toluene, 14g of styrene, and 46g of butadiene were added to a 1-liter pressure-resistant reactor and mixed thoroughly. The mixture was heated to 90°C, and 1.8g of 1.6mol / L tert-butyl catalyst was added. After reacting for 90 minutes, the styrene conversion rate was tested and found to be 99.8%. 0.3g of styrene was added, and the reaction was continued for another 60 minutes.
[0063] Add 0.06 g of methyltrichlorosilane and continue the reaction at 90 °C for 30 min.
[0064] 2.5g of methylvinyldimethoxysilane and 0.9g of benzoyl oxidase catalyst were added and reacted at 100℃ for 60min. The mixture was then cooled to room temperature, and 0.7g of antioxidant 1010 was added. The mixture was stirred until homogeneous to obtain a silicone-modified butadiene-styrene copolymer.
[0065] The molecular weight and its distribution were tested, as shown in Table 1.
[0066] Comparative Example 1
[0067] The preparation method of Example 1 was followed, except that tetrachlorosilane was not added, while other operations and conditions remained unchanged, to obtain an organosilicon-modified butadiene and styrene copolymer.
[0068] The molecular weight and its distribution were tested, as shown in Table 1.
[0069] Comparative Example 2
[0070] The preparation method of Example 1 is the same, except that vinyltriethoxysilane is not added, while other operations and conditions remain unchanged, to obtain organosilicon-modified butadiene and styrene copolymer.
[0071] The molecular weight and its distribution were tested, as shown in Table 1.
[0072] Comparative Example 3
[0073] The preparation method of Example 1 is the same, except that vinyltriethoxysilane is replaced with an equal amount of tetrachlorosilane, while other operations and conditions remain unchanged, to obtain organosilicon-modified butadiene and styrene copolymer.
[0074] The molecular weight and its distribution were tested, as shown in Table 1.
[0075] Comparative Example 4
[0076] 300g of cyclohexane, 12g of styrene, and 48g of butadiene were added to a 1-liter pressure-resistant reactor and mixed thoroughly. The mixture was heated to 50°C, and 1.6g of 1.6mol / L n-butyl catalyst was added. After reacting for 60 minutes, the styrene conversion rate was measured to be 99.4%. 0.2g of styrene was added, and the reaction continued for another 60 minutes. A copolymer of butadiene and styrene was obtained.
[0077] The molecular weight and its distribution were tested, as shown in Table 1.
[0078] Table 1. Indicators of the organosilicon-modified butadiene-styrene copolymers prepared in the examples and comparative examples.
[0079]
[0080]
[0081]
Application Example
[0082] The organosilicon-modified butadiene and styrene copolymers prepared according to the various examples and comparative examples were used to prepare test samples, and their properties were tested. The test results are shown in Table 2.
[0083] According to the mass ratio, 0.5 parts KH570 and 0.5 parts tetraethyl orthosilicate were added to 100 parts of silicone-modified butadiene and styrene copolymer, and mixed for 10 minutes using a high-speed disperser to obtain a homogeneous adhesive. The adhesive was placed in a custom mold and the solvent was removed using a vacuum drying oven to obtain an adhesive film of uniform thickness. The film was then cured in a constant temperature and humidity chamber for 72 hours. The sample condition was observed, and those that could be cured were cut into standard specimens using a cutter to obtain tensile specimens. For shearing specimens, the adhesive was evenly applied between two aluminum sheets, and the specimens were fixed in place using clamps and cured in a constant temperature and humidity chamber for 72 hours to obtain sheared specimens. Both types of specimens were tested using a universal testing machine.
[0084] Table 2 Performance test results of the examples and comparative samples
[0085]
[0086] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing an organosilicon-modified butadiene-styrene copolymer, characterized in that, Includes the following steps: 1) Styrene, butadiene, catalyst A, and organic solvent are mixed to carry out the first stage polymerization reaction, and then styrene is added to continue the second stage polymerization reaction; 2) Add a silane coupling agent to the system in step 1) to carry out a coupling reaction; 3) Add vinylsilane coupling agent and catalyst B to the system in step 2) to react and obtain the organosilicon-modified butadiene and styrene copolymer; Step 2) The silane coupling agent is selected from one or more of chlorosilanes and alkoxysilanes; Step 3) The vinylsilane coupling agent is selected from one or more of vinylalkoxysilanes.
2. The preparation method according to claim 1, characterized in that, Step 1) The total amount of styrene used is 10-31% of the mass of butadiene; and / or Step 1) The catalyst A is selected from one or more organolithium compounds; and / or Step 1) The organic solvent is one or more of cyclohexane, n-hexane, toluene, tetrahydrofuran, and n-heptane.
3. The preparation method according to claim 2, characterized in that, Step 1) The total amount of styrene used is 15-20% of the mass of butadiene.
4. The preparation method according to claim 2, characterized in that, Step 1) The catalyst A is selected from one or more of methyl lithium, ethyl lithium, tert-butyl lithium, n-butyl lithium, sec-butyl lithium, trimethylsilyl lithium, and phenyl lithium.
5. The preparation method according to claim 1, characterized in that, Step 1) The amount of styrene added is 1.6-10 wt% of the total styrene content.
6. The preparation method according to claim 5, characterized in that, Step 1) The amount of styrene added is 5-8 wt% of the total styrene content.
7. The preparation method according to claim 1, characterized in that, Step 1) The amount of catalyst A is 1-4% of the total mass of the polymer monomers, wherein the polymer monomers are styrene and butadiene.
8. The preparation method according to claim 7, characterized in that, Step 1) The amount of catalyst A is 2-3% of the total mass of the polymer monomers, wherein the polymer monomers are styrene and butadiene.
9. The preparation method according to claim 1, characterized in that, Step 1) The amount of organic solvent used is 1-20 times the total mass of the polymer monomers, wherein the polymer monomers are styrene and butadiene.
10. The preparation method according to claim 9, characterized in that, Step 1) The amount of organic solvent used is 5-15 times the total mass of the polymer monomers, wherein the polymer monomers are styrene and butadiene.
11. The preparation method according to claim 1, characterized in that, The polymerization reaction described in step 1) is carried out at a temperature of 30-90℃.
12. The preparation method according to claim 1, characterized in that, Step 1) Test the conversion rate during the first stage of polymerization. After the styrene monomer conversion rate rises to over 98%, add styrene to continue the second stage of polymerization.
13. The preparation method according to claim 1, characterized in that, Step 1) The first stage of polymerization reaction takes 30-120 minutes. After adding styrene, the second stage of polymerization reaction continues for another 30-120 minutes.
14. The preparation method according to claim 1, characterized in that, The silane coupling agent is selected from one or more of tetrachlorosilane, methyltrichlorosilane, dimethyldichlorosilane, tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane, or a mixture thereof.
15. The preparation method according to claim 1, characterized in that, The amount of silane coupling agent used in step 2) is 0.01-0.1% of the mass of the polymeric monomers in step 1), wherein the polymeric monomers are styrene and butadiene.
16. The preparation method according to claim 15, characterized in that, In step 2), the amount of silane coupling agent used is 0.03-0.08% of the mass of the polymeric monomers in step 1), wherein the polymeric monomers are styrene and butadiene.
17. The preparation method according to claim 1, characterized in that, The coupling reaction described in step 2) is carried out at a temperature of 30-60℃ for a time of 30-120 min.
18. The preparation method according to claim 1, characterized in that, Step 3) The catalyst B is selected from one or more free radical initiators or a mixture thereof.
19. The preparation method according to claim 1, characterized in that, Step 3) The vinyl silane coupling agent is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, and methylvinyldiethoxysilane, or a mixture thereof.
20. The preparation method according to claim 19, characterized in that, Step 3) The catalyst B is selected from one or more of benzoyl peroxide, azobisisobutyronitrile, and dimethyl azobisisobutyrate, or a mixture thereof.
21. The preparation method according to claim 1, characterized in that, Step 3) The amount of vinylsilane used is 1-7% of the mass of the polymer monomers in Step 1), wherein the polymer monomers are styrene and butadiene.
22. The preparation method according to claim 21, characterized in that, Step 3) The amount of vinylsilane used is 3-5% of the mass of the polymer monomers in Step 1), wherein the polymer monomers are styrene and butadiene.
23. The preparation method according to claim 1, characterized in that, Step 3) The amount of catalyst B used is 0.1-2% of the mass of the polymerizing monomer in step 1), wherein the polymerizing monomer is styrene and butadiene.
24. The preparation method according to claim 23, characterized in that, In step 3), the amount of catalyst B is 0.5-1.5% of the mass of the polymerizing monomers in step 1), wherein the polymerizing monomers are styrene and butadiene.
25. The preparation method according to claim 1, characterized in that, The reaction described in step 3) is carried out at a temperature of 80-120℃ for a time of 60-180 minutes.
26. The preparation method according to claim 1, characterized in that, Step 3) Antioxidants are added to the system.
27. The preparation method according to claim 26, characterized in that, The antioxidant is one or a mixture of 2,6-di-tert-butyl-p-methylphenol, octadecyl di-T-butyl-4-hydroxyhydrocinnamate, and pentaerythritol tetra(3,5-di-tert-butyl-4-hydroxyhydrocinnamate).
28. The preparation method according to claim 26, characterized in that, The amount of antioxidant used is 0.1-2% of the mass of the polymeric monomer in step 1), wherein the polymeric monomer is styrene and butadiene.
29. The preparation method according to claim 28, characterized in that, The amount of antioxidant used is 0.5-1.5% of the mass of the polymeric monomers in step 1), wherein the polymeric monomers are styrene and butadiene.
30. An organosilicon-modified butadiene-styrene copolymer, the copolymer being prepared by the method according to any one of claims 1-29.
31. The use of the silicone-modified butadiene and styrene copolymer as described in claim 30, or the silicone-modified butadiene and styrene copolymer prepared by any one of claims 1-29, as an adhesive.
32. The application according to claim 31, characterized in that, As a waterproof sealant.