Organosilicon modified butadiene and styrene copolymer, and preparation method and application thereof

Abstract

The invention discloses an organic silicon modified butadiene and styrene copolymer as well as a preparation method and application thereof, the preparation method comprises the following steps: 1) mixing styrene, butadiene, a catalyst A and an organic solvent to carry out first-stage polymerization reaction, and then supplementing styrene to continue to carry out second-stage polymerization reaction; (2) adding a silane coupling agent into the system in the step (1) to carry out coupling reaction; and (3) adding a vinyl silane coupling agent and a catalyst B into the system in the step (2) for reaction to obtain the organosilicone modified butadiene and styrene copolymer. Silane with reactivity is creatively introduced into a polymer network, so that the organosilicone modified butadiene and styrene copolymer has self-curing capability, and chemical crosslinking of molecules can be realized under the action of the catalyst and water vapor; and the strength is better. The organic silicon modified butadiene and styrene copolymer can realize moisture curing at room temperature, is simple and convenient in use process, and can be used as an adhesive.

Description

Technical Field

[0001] The invention relates to a butadiene and styrene copolymer, in particular to an organosilicon-modified butadiene and styrene copolymer and a preparation method and application thereof. Background Art

[0002] Butadiene and styrene are common chemical raw materials. The polymers synthesized from them, such as styrene-butadiene rubber and SBS, are widely used in tires, plastic modification, adhesives and other fields, and have achieved good market feedback. When traditional butadiene / styrene copolymers are used as adhesives, they need to be compounded with auxiliary raw materials such as tackifying resins and fillers to obtain a certain bonding strength. This traditional combination is not chemically cross-linked, resulting in limited strength of the colloid itself, which cannot meet the increasingly demanding application requirements.

[0003] For example, patent CN101622323B optimizes the bonding strength and application range of formulated adhesive products by optimizing the adhesive formula based on SBS resin, but does not mention a method for structurally modifying the polymer to improve the bonding strength.

[0004] The same patent CN 115260952B improves the weather resistance and bonding strength of the adhesive by optimizing the formula of butadiene / styrene copolymer as the base resin. It also does not mention the method of improving its bonding performance by designing the resin molecular structure.

[0005] In summary, the industry generally adopts the method of formula optimization to optimize the performance of adhesive products based on butadiene / styrene polymerization resins, and there has been no report on molecular structure design for its application to improve its performance. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes an organosilicon-modified butadiene and styrene copolymer and a preparation method thereof. The present invention creatively introduces reactive silane into the polymer network, so that it has the ability of self-curing, can achieve chemical cross-linking of molecules under the action of catalyst and water vapor, and has better strength.

[0007] The organosilicon-modified butadiene and styrene copolymer of the present invention can realize moisture curing at room temperature, has a simple use process, and can be used as an adhesive.

[0008] In a first aspect, the present invention provides a method for preparing a silicone-modified butadiene-styrene copolymer, comprising the following steps:

[0009] 1) Styrene, butadiene, catalyst A and organic solvent are mixed to carry out a first stage polymerization reaction, and then styrene is added to continue a second stage polymerization reaction;

[0010] 2) adding a silane coupling agent to the system of step 1) to carry out a coupling reaction;

[0011] 3) Adding a vinyl silane coupling agent and a catalyst B to the system of step 2) to react, thereby obtaining the organosilicon-modified butadiene and styrene copolymer.

[0012] As a preferred embodiment of the present invention, the total amount of styrene in step 1) is 10-31% of the mass of butadiene, such as 10%, 13%, 15%, 18%, 20%, 22%, 25%, 28%, 31%, etc., preferably 15-20%;

[0013] Preferably, the additional styrene is 1.6-10wt% of the total amount of styrene used, such as 1.6%, 2%, 3%, 5%, 7%, 9%, 10%, etc., preferably 5-8wt%.

[0014] As a preferred embodiment of the present invention, the catalyst A in step 1) is selected from an organic lithium compound, preferably one or more of methyl lithium, ethyl lithium, tert-butyl lithium, n-butyl lithium, sec-butyl lithium, trimethylsilyl lithium, and phenyl lithium. In practical applications, the catalyst A can be directly used in pure form or dissolved in an organic solvent for use. The present invention has no special requirements.

[0015] Preferably, the amount of the catalyst A is 1-4% of the total mass of the polymerizable monomers, such as 1%, 2%, 3%, 4%, etc., preferably 2-3%, and the polymerizable monomers include styrene and butadiene.

[0016] As a preferred embodiment of the present invention, the organic solvent in step 1) can be selected from conventional organic solvents in the field, preferably one or more of cyclohexane, n-hexane, toluene, tetrahydrofuran, and n-heptane;

[0017] Preferably, the amount of the organic solvent is 1-20 times the total mass of the polymerized monomers, such as 1, 3, 5, 8, 10, 12, 15, 18, 20, etc., preferably 5-15 times. The polymerized monomers include styrene and butadiene.

[0018] As a preferred embodiment of the present invention, the polymerization reaction in step 1) is performed at a temperature of 30-90°C, such as 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 polymerization reaction, and after the styrene monomer conversion rate rises to more than 98%, styrene is added to continue the second stage polymerization reaction;

[0020] Preferably, the first stage polymerization reaction time is 30-120min, for example 30min, 50min, 80min, 100min, 120min, etc., and the second stage polymerization reaction time after adding styrene is 30-120min, for example 30min, 50min, 80min, 100min, 120min, etc.

[0021] As a preferred embodiment of the present invention, the silane coupling agent in step 2) is selected from chlorosilanes and alkoxysilanes, preferably a mixture of one or more 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 polymerized monomers in step 1), such as 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, etc., preferably 0.03-0.08%, and the polymerized monomers include 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 vinyl alkoxysilane, preferably a mixture of one or more of vinyl trimethoxysilane, vinyl triethoxysilane, methyl vinyl dimethoxysilane and methyl vinyl diethoxysilane;

[0025] Preferably, the amount of the vinyl silane is 1-7% of the mass of the polymerized monomers in step 1), such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, etc., preferably 3-5%, and the polymerized monomers include 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 a mixture of one or more of benzoyl peroxide, azobisisobutyronitrile, and dimethyl azobisisobutyrate;

[0027] Preferably, the amount of the catalyst B is 0.1-2% by mass of the polymerized monomers 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 polymerized monomers include 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, for example, 80°C, 90°C, 100°C, 110°C, 120°C, etc., and the reaction time is 60-180min, for example, 60min, 80min, 100min, 120min, 150min, 180min, 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, preferably a mixture of one or more of 2,6-di-tert-butyl-p-methylphenol (BHT), octadecyl di-T-butyl-4-hydroxyhydrocinnamate (antioxidant 1076), and pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (antioxidant 1010);

[0031] Preferably, the amount of the antioxidant is 0.1-2% by mass of the polymerized monomers 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 polymerized monomers include styrene and butadiene.

[0032] In a second aspect, the present invention provides a silicone-modified butadiene and styrene copolymer, which is prepared by the method described above.

[0033] The polymer described in the present invention is a silicone-modified star-shaped butadiene and styrene copolymer with a number average molecular weight of 5000-30000 and containing moisture-curable siloxane groups.

[0034] In a third aspect, the present invention also provides an application of the organosilicon-modified butadiene and styrene copolymer prepared by the method described above as an adhesive, especially as a waterproof sealing adhesive.

[0035] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0036] The invention uses a silane coupling agent to modify the synthesized butadiene styrene copolymer, creatively introduces reactive silane into the polymer network, so that the copolymer has the ability of self-curing, can achieve chemical cross-linking of molecules under the action of catalyst and water vapor, and has better strength. In addition, the copolymer can be cured at room temperature, which can provide more convenient construction conditions. DETAILED DESCRIPTION

[0037] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0038] Unless otherwise specified, the raw materials and reagents used in the examples of the present invention can be purchased from commercial sources.

[0039] The main testing methods involved in the embodiments of the present invention are as follows:

[0040] Molecular weight and its distribution (PDI) test method: Agilent PL-GPC-50 gel chromatography was used for testing, and the mobile phase was tetrahydrofuran;

[0041] Adhesion test (i.e. aluminum sheet shear strength): Use universal material testing machine AI-7000S / MU to test, shear mode, the test sample is anodized aluminum sheet;

[0042] Tensile strength: tested using universal material testing machine AI-7000S / MU in accordance with national standard GB / T 528-2009;

[0043] Elongation at break: tested using universal material testing machine AI-7000S / MU in accordance with national standard GB / T 528-2009;

[0044] Anti-aging test method: Use a constant temperature and humidity chamber with double 85 degrees to age for 72 hours, then test the tensile strength and elongation at break.

[0045] Conversion rate test method: Use Agilent 8860 gas chromatograph to test the residual monomer content and calculate the conversion rate.

[0046] Example 1

[0047] In a 1-liter pressure reactor, add 300 g of cyclohexane, 12 g of styrene, and 48 g of butadiene, mix well, heat to 50°C, add 1.2 g of 1.6 mol / L n-butyl catalyst, and after reacting for 60 minutes, test that the styrene conversion rate reaches 99.4%. Add 0.2 g of styrene and continue the reaction for 60 minutes.

[0048] Add 0.02 g of tetrachlorosilane and continue the reaction at 50°C for 30 min.

[0049] 2 g of vinyl triethoxysilane and 0.9 g of catalyst benzoyl oxide were added, reacted at 100° C. for 60 min, then cooled to room temperature, and 0.6 g of antioxidant BHT was added and stirred evenly to obtain an organosilicon-modified butadiene and styrene copolymer.

[0050] The tested molecular weights and their distribution are shown in Table 1.

[0051] Example 2

[0052] In a 1-liter pressure reactor, add 300 g of cyclohexane, 100 g of n-hexane, 10 g of styrene, and 50 g of butadiene, mix evenly, heat to 50°C, add 1.4 g of 1.6 mol / L n-butyl catalyst, and react for 45 minutes until the styrene conversion rate reaches 99.1%. Add 0.25 g of styrene and continue the reaction for 60 minutes.

[0053] Add 0.03 g of tetrachlorosilane and continue the reaction at 50°C for 30 min.

[0054] 1 g of vinyl triethoxysilane and 0.9 g of catalyst benzoyl oxide were added, reacted at 100° C. for 60 min, then cooled to room temperature, 0.8 g of antioxidant BHT was added, and stirred evenly to obtain an organosilicon-modified butadiene and styrene copolymer.

[0055] The tested molecular weights and their distribution are shown in Table 1.

[0056] Example 3

[0057] In a 1-liter pressure reactor, add 500 g of n-hexane, 100 g of tetrahydrofuran, 8 g of styrene, and 52 g of butadiene, mix evenly, heat to 70°C, add 1.6 g of 1.6 mol / L n-butyl catalyst, and react for 90 minutes to test that the styrene conversion rate reaches 99.5%. Add 0.5 g of styrene and continue the reaction for 60 minutes.

[0058] Add 0.04 g of methyltrichlorosilane and continue the reaction at 60°C for 30 min.

[0059] 1.5 g of vinyltrimethoxysilane and 0.6 g of catalyst oxidized benzoyl were added, reacted at 110° C. for 60 min, then cooled to room temperature, 0.9 g of antioxidant 1076 was added, and stirred evenly to obtain a silicone-modified butadiene and styrene copolymer.

[0060] The tested molecular weights and their distribution are shown in Table 1.

[0061] Example 4

[0062] 800 g of toluene, 14 g of styrene and 46 g of butadiene were added to a 1-liter pressure reactor and mixed evenly. The mixture was heated to 90°C and 1.8 g of 1.6 mol / L tert-butyl catalyst was added. After reacting for 90 minutes, the styrene conversion rate was tested to be 99.8%. 0.3 g of styrene was added and the reaction was continued for 60 minutes.

[0063] 0.06 g of methyltrichlorosilane was added, and the reaction was continued at 90°C for 30 min.

[0064] Add 2.5 g of methylvinyldimethoxysilane and 0.9 g of catalyst oxidized benzoyl, react at 100° C. for 60 min, then cool to room temperature, add 0.7 g of antioxidant 1010, stir evenly, and obtain a silicone-modified butadiene and styrene copolymer.

[0065] The tested molecular weights and their distribution are shown in Table 1.

[0066] Comparative Example 1

[0067] The preparation method of Example 1 was used with the exception that tetrachlorosilane was not added and other operations and conditions remained unchanged to obtain an organosilicon-modified butadiene and styrene copolymer.

[0068] The tested molecular weights and their distribution are shown in Table 1.

[0069] Comparative Example 2

[0070] The preparation method of Example 1 was used with the exception that no vinyltriethoxysilane was added and other operations and conditions remained unchanged to obtain an organosilicon-modified butadiene and styrene copolymer.

[0071] The tested molecular weights and their distribution are shown in Table 1.

[0072] Comparative Example 3

[0073] The preparation method of Example 1 is referred to, except that vinyltriethoxysilane is replaced by an equal amount of tetrachlorosilane, and other operations and conditions remain unchanged, to obtain an organosilicon-modified butadiene and styrene copolymer.

[0074] The tested molecular weights and their distribution are shown in Table 1.

[0075] Comparative Example 4

[0076] In a 1-liter pressure-resistant reactor, 300 g of cyclohexane, 12 g of styrene, and 48 g of butadiene were added and mixed evenly, heated to 50°C, and 1.6 g of 1.6 mol / L n-butyl catalyst was added. After reacting for 60 minutes, the styrene conversion rate was tested to be 99.4%. 0.2 g of styrene was added and the reaction was continued for 60 minutes. A butadiene and styrene copolymer was obtained.

[0077] The tested molecular weights and their distribution are shown in Table 1.

[0078] Table 1 Indexes of silicone-modified butadiene and styrene copolymers obtained in Examples and Comparative Examples

[0079]

[0080]

[0081]

Application examples

[0082] The test samples were prepared according to the following methods using the organosilicon-modified butadiene and styrene copolymers prepared in the examples and comparative examples, and their properties were tested. The test results are shown in Table 2.

[0083] According to the mass percentage, add 0.5 parts of KH570 and 0.5 parts of tetraethyl orthosilicate to 100 parts of silicone-modified butadiene and styrene copolymer, and mix them for 10 minutes using a high-speed disperser to obtain a uniform adhesive solution. Place the adhesive solution in a custom mold and use a vacuum drying oven to remove the solvent to obtain an adhesive film of uniform thickness, then place it in a constant temperature and humidity chamber for curing for 72 hours, observe the state of the sample, and use a cutter to cut the standard sample that can be cured to obtain a tensile specimen. Shear specimens: Apply the adhesive solution evenly between two aluminum sheets, use a clamp to fix it in a constant temperature and humidity chamber for curing for 72 hours to obtain a shear specimen. Both specimens were tested using a universal material testing machine.

[0084] Table 2 Performance test results of examples and comparative examples

[0085]

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a silicone-modified butadiene and styrene copolymer, characterized in that: The following steps are involved: 1) Styrene, butadiene, catalyst A and organic solvent are mixed to carry out a first stage polymerization reaction, and then styrene is added to continue a second stage polymerization reaction; 2) adding a silane coupling agent to the system of step 1) to carry out a coupling reaction; 3) Adding a vinyl silane coupling agent and a catalyst B to the system of step 2) to react, thereby obtaining the organosilicon-modified butadiene and styrene copolymer.

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, preferably 15-20%; Preferably, the additional styrene is 1.6-10wt% of the total amount of styrene used, preferably 5-8wt%; and / or Step 1) the catalyst A is selected from an organic lithium compound, preferably one or more of methyl lithium, ethyl lithium, tert-butyl lithium, n-butyl lithium, sec-butyl lithium, trimethylsilyl lithium, and phenyl lithium; Preferably, the amount of the catalyst A is 1-4%, preferably 2-3%, of the total mass of the polymerizable monomers, wherein the polymerizable monomers include styrene and butadiene; and / or Step 1) the organic solvent is one or more of cyclohexane, n-hexane, toluene, tetrahydrofuran, and n-heptane; Preferably, the amount of the organic solvent is 1-20 times, preferably 5-15 times, the total mass of the polymerizable monomers, and the polymerizable monomers include styrene and butadiene.

3. The preparation method according to claim 1, characterized in that: The polymerization reaction in step 1) is carried out at a temperature of 30-90°C; Preferably, the conversion rate is tested during the first stage polymerization reaction, and after the styrene monomer conversion rate rises to more than 98%, styrene is added to continue the second stage polymerization reaction; Preferably, the first stage polymerization reaction time is 30-120 min, and the second stage polymerization reaction time after adding styrene is 30-120 min.

4. The preparation method according to claim 1, characterized in that: Step 2) the silane coupling agent is selected from chlorosilanes and alkoxysilanes, preferably a mixture of one or more of tetrachlorosilane, methyltrichlorosilane, dimethyldichlorosilane, tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane and methyltriethoxysilane; Preferably, the amount of the silane coupling agent used is 0.01-0.1%, preferably 0.03-0.08% of the mass of the polymerized monomers in step 1), and the polymerized monomers include styrene and butadiene.

5. The preparation method according to claim 1, characterized in that: Step 2) The coupling reaction is carried out at a temperature of 30-60° C. and a time of 30-120 min.

6. The preparation method according to claim 1, characterized in that: Step 3) the vinyl silane coupling agent is selected from vinyl alkoxysilane, preferably a mixture of one or more of vinyl trimethoxysilane, vinyl triethoxysilane, methyl vinyl dimethoxysilane and methyl vinyl diethoxysilane; Preferably, the amount of the vinyl silane is 1-7%, preferably 3-5% of the mass of the polymerized monomers in step 1), and the polymerized monomers include styrene and butadiene; and / or Step 3) the catalyst B is selected from free radical initiators commonly used in the field, preferably a mixture of one or more of benzoyl peroxide, azobisisobutyronitrile, and dimethyl azobisisobutyrate; Preferably, the amount of the catalyst B used is 0.1-2%, preferably 0.5-1.5% of the mass of the polymerized monomers in step 1), and the polymerized monomers include styrene and butadiene.

7. The preparation method according to claim 1, characterized in that: Step 3) The reaction temperature is 80-120°C and the reaction time is 60-180 min.

8. The preparation method according to claim 1, characterized in that: Step 3) adding an antioxidant into the system; Preferably, the antioxidant is a mixture of one or more of 2,6-di-tert-butyl-p-methylphenol, octadecyl di-T-butyl-4-hydroxyhydrocinnamate, and pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate); Preferably, the amount of the antioxidant is 0.1-2%, preferably 0.5-1.5% of the mass of the polymerized monomers in step 1), and the polymerized monomers include styrene and butadiene.

9. An organosilicon-modified butadiene and styrene copolymer, which is prepared by the method according to any one of claims 1 to 8.

10. Use of the organosilicon-modified butadiene and styrene copolymer as claimed in claim 9, or the organosilicon-modified butadiene and styrene copolymer prepared by the method according to any one of claims 1 to 8 as an adhesive, especially as a waterproof sealing adhesive.

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