Functional organic silicon adhesive and preparation method thereof

Abstract

The invention relates to the technical field of adhesives, and discloses a functional organic silicon adhesive and a preparation method thereof.The functional organic silicon adhesive is formed by mixing vinyl-terminated methyl phenyl polysiloxane serving as a base material and a tackifying component, a fiber anti-cracking component and the like serving as auxiliary materials. The fiber anti-cracking component contains a large number of branched macromolecular chains connected through silicon-oxygen bonds, and rich silicon-hydrogen bonds exist in the macromolecular chains at the same time, so that the vinyl-terminated methyl phenyl polysiloxane matrix and the tackifying component can be connected in the subsequent adhesive curing process in which a platinum catalyst participates, and the viscosity of the adhesive is improved. According to the present invention, the palm fiber exists in the adhesive in the form of the chemical connection point through the connection mode, the anti-cracking performance of the adhesive is enhanced, the tackifying component can enter the adhesive matrix, and the ether bond and the active group in the glucose can form the hydrogen bond with the bonded matrix so as to further enhance the bonding performance of the organic silica gel adhesive;

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and in particular to a functional organic silicone adhesive and a preparation method thereof. Background Art

[0002] Organic silicone adhesive is a high-performance adhesive made by special process based on organic silicon compounds. Its biggest feature is its excellent temperature resistance, weather resistance, aging resistance and electrical insulation performance. Whether in extremely high or low temperature environment, organic silicone adhesive can maintain stable bonding strength and is not prone to embrittlement. In addition, it also has good elasticity and waterproof and moisture-proof properties, and can adapt to various complex and changeable working environments. Therefore, in recent years, it has gradually shown great application prospects in many industries such as construction, electronic appliances, automobiles and new energy.

[0003] However, organic silicone adhesives still have obvious problems at this stage, the most notable of which is the problem of easy cracking. Once the adhesive cracks, the waterproof and moisture-proof properties of the adhesive may be affected, thereby reducing the service life of the adhered device. Moreover, the bonding performance of the organic silicone adhesive itself is somewhat inferior to that of conventional acrylic resin adhesives, which indirectly leads to a significant limitation on the application scope of the organic silicone adhesive. Based on this, the present invention provides a functional organic silicone adhesive that can solve the problems existing in the prior art. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the purpose of the present invention is to provide a functional organic silicone adhesive and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a functional organic silicone adhesive, the organic silicone adhesive comprising the following raw materials in parts by weight: 50-55 parts of terminal vinyl methyl phenyl polysiloxane; 2-3.5 parts of viscosity-increasing component; 1-3 parts of fiber anti-cracking component; 60-80 parts of dimethyl silicone oil; Catalyst 0.5-1 part; The preparation method comprises the following steps: The first step is to add the terminal vinyl methyl phenyl polysiloxane, the viscosity-increasing component, the dimethyl silicone oil and the catalyst into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 300-500 r / min for 30-60 minutes to form a mixture; The second step is to add the fiber anti-cracking component into the mixture, continue stirring for 2-4 hours, reduce the pressure to degas, and discharge the material to obtain the organic silicone adhesive.

[0006] As a further embodiment of the present invention, the specific preparation method of the viscosity-increasing component is as follows: Glucose and dimethyl sulfoxide are added to a polymerization kettle, nitrogen is passed through for protection, stirring is started, and after a uniform precursor liquid is formed, an alkaline hydroxide aqueous solution is added to the polymerization kettle. After the addition is completed, the temperature is raised to 50-60°C and stirred for 20-30 minutes. Then, 3,4-dichloro-1-butene is added to the polymerization kettle. After the addition is completed, the temperature is further raised to 80-90°C and maintained under stirring for 8-12 hours. The nitrogen is removed, the solvent is evaporated and removed, the temperature is lowered and the material is discharged. The product is collected to obtain a viscosity-increasing component.

[0007] As a further embodiment of the present invention, the alkaline hydroxide is sodium hydroxide or potassium hydroxide.

[0008] As a further embodiment of the present invention, the mass fraction of the alkaline hydroxide aqueous solution is 10-25%.

[0009] As a further embodiment of the present invention, the molar ratio of glucose to 3,4-dichloro-1-butene is 1:1.

[0010] In the above technical scheme, by controlling the dosage ratio of glucose and 3,4-dichloro-1-butene and using alkaline hydroxide for catalysis, the active groups between each other undergo continuous and uninterrupted substitution reactions to obtain a polymeric macromolecular substance alternately connected by ether bonds, namely, a viscosity-enhancing component.

[0011] As a further solution of the present invention, the specific preparation method of the fiber anti-cracking component is as follows: The palm fiber treated with alkali is added to toluene, and ultrasonically dispersed for 30-60 minutes to form a uniform dispersion. Methyldichlorosilane is then added to the dispersion. After the addition is completed, nitrogen is introduced for protection. The temperature is raised to 70-80°C, and after stirring for 1-2 hours, the temperature is lowered to 50-55°C. A branching agent and an alkaline catalyst are continuously added. After the addition is completed, the temperature is further raised to 60-70°C, and stirring is continued for 6-9 hours. The material is cooled and discharged, and the solid material is separated by centrifugation. The fiber anti-cracking component can be obtained after washing and vacuum drying.

[0012] As a further embodiment of the present invention, the alkali treatment method of the palm fiber is specifically as follows: The palm fiber is soaked in a sodium hydroxide aqueous solution with a mass fraction of 5-20%, stirred at room temperature for 30-60 minutes, taken out, washed with water until neutral, and then vacuum dried.

[0013] As a further embodiment of the present invention, the branching agent is pentaerythritol or triethanolamine; and the alkaline catalyst is triethylamine.

[0014] In the above technical scheme, the palm fiber is firstly treated with alkali so that the active hydroxyl groups on its surface can be fully exposed, and then the alkali-treated palm fiber is surface-modified using methyldichlorosilane, and then a branching agent containing multiple substituted hydroxyl groups is added to react with methyldichlorosilane and chain extension is performed, thereby modifying the surface of the palm fiber with a branched macromolecular chain, and the molecular chain contains abundant Si-H bonds, i.e., the fiber anti-cracking component.

[0015] As a further embodiment of the present invention, the catalyst is a platinum-vinyl complex or a platinum-alkyne complex.

[0016] A functional organic silicone adhesive is prepared by adopting the preparation method.

[0017] Beneficial effects of the present invention: The fiber anti-cracking component structure prepared by the present invention contains a large number of branched macromolecular chains connected by silicon-oxygen bonds, and there are abundant silicon-hydrogen bonds in the molecular chain. In the subsequent adhesive curing process involving a platinum catalyst, the presence of silicon-hydrogen bonds can react with the terminal vinylmethylphenyl polysiloxane matrix and the unsaturated olefin functional group in the viscosity-increasing component structure to undergo silicon-hydrogen addition reaction, thereby connecting the three in the form of chemical bonds. On the one hand, this connection method can make the palm fiber exist in the adhesive in the form of a chemical connection point, and due to the presence of branched molecular chains, the molecular chain of the adhesive can be converted from a straight chain type to a three-dimensional cross-linked network type, which not only enables the adhesive to have higher cohesive energy and show more excellent bonding strength, but also enables the palm fiber and the matrix to produce a structure similar to a "mortise and tenon" type, thereby effectively exerting the advantages of the palm fiber and enhancing the anti-cracking performance of the adhesive.

[0018] The viscosity-increasing component prepared by the present invention is a polymeric macromolecular substance alternately connected by ether bonds. Since the unsaturated olefinic functional groups in its structure can participate in the curing during the subsequent curing process, it can enter the adhesive matrix. The active groups in the ether bonds and glucose can form hydrogen bonds with the adhered matrix, thereby further enhancing the bonding performance of the organic silicone adhesive.

[0019] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. DETAILED DESCRIPTION

[0020] The technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Preparation Example 1 Preparation of viscosity-enhancing component: 0.5 g of glucose and dimethyl sulfoxide were added to the polymerization kettle, nitrogen was passed for protection, stirring was started, and after a uniform precursor solution was formed, 5 mL of a 25% by mass sodium hydroxide aqueous solution was added to the polymerization kettle. After the addition was completed, the temperature was raised to 55°C and stirred for 30 minutes. Then, 0.32 g of 3,4-dichloro-1-butene was added to the polymerization kettle. After the addition was completed, the temperature was further raised to 85°C and kept under stirring for 9 hours. Then, the nitrogen was removed, the solvent was evaporated, the temperature was lowered and the material was discharged. The product was collected to obtain a viscosity-increasing component.

[0022] The thickening component was titrated using the iodine titration method. 0.2 g of the thickening component was taken as a sample, a 0.1 M sodium thiosulfate solution was used as the standard solution, a 2% starch aqueous solution was used as an indicator, and the mass fraction of potassium iodide used was 15%. The test results showed that the unsaturated olefin content of the thickening component was 1.224 mmol / g.

[0023] Preparation Example 2 Preparation of fiber anti-cracking components: Step 1: Soak the palm fiber in a 20% sodium hydroxide aqueous solution, stir at room temperature for 40 minutes, take it out, wash it with water until it is neutral, and then vacuum dry it; Step 2: Add 3 g of alkali-treated palm fiber to toluene, ultrasonically disperse for 40 minutes to form a uniform dispersion, then add 8.5 g of methyldichlorosilane to the dispersion, and after the addition, introduce nitrogen for protection, raise the temperature to 75°C, keep stirring for 1 hour, then lower the temperature to 50°C, continue to add 5 g of triethanolamine and 0.5 g of triethylamine, and after the addition, continue to raise the temperature to 70°C, continue stirring for 8 hours, cool and discharge, centrifuge to separate the solid material, wash and vacuum dry, and then obtain the fiber anti-cracking component.

[0024] The element content of the fiber anti-cracking component was analyzed using a TQ-3C element analyzer. The elements tested were mainly C and N. The test results showed that the percentage of carbon was 48.4% and the percentage of nitrogen was 5.41%. Obviously, the nitrogen element came from triethanolamine. Example 1

[0025] A functional organic silicone adhesive, comprising the following raw materials in parts by weight: 50 parts of terminal vinyl methyl phenyl polysiloxane; 2 parts of viscosity-enhancing component; 1 part of fiber anti-cracking component; 60 parts of dimethyl silicone oil; 0.5 parts of platinum-vinyl complex; The preparation method comprises the following steps: The first step is to add the terminal vinyl methyl phenyl polysiloxane, the viscosity-increasing component, the dimethyl silicone oil and the platinum-vinyl complex into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 300 r / min for 60 minutes to form a mixture; The second step is to add the fiber anti-cracking component into the mixture, continue stirring for 2 hours, reduce the pressure to degas, and discharge the material to obtain the organic silicone adhesive.

[0026] The preparation method of the viscosity-enhancing component is shown in Preparation Example 1; the fiber anti-cracking component is shown in Preparation Example 2, and the rest are the same. Example 2

[0027] A functional organic silicone adhesive, comprising the following raw materials in parts by weight: 52 parts of terminal vinyl methyl phenyl polysiloxane; 3.5 parts of viscosity-enhancing component; 2.5 parts of fiber anti-cracking component; 65 parts of dimethyl silicone oil; 0.6 parts of platinum-alkyne complex; The preparation method comprises the following steps: The first step is to add the terminal vinyl methyl phenyl polysiloxane, the viscosity-increasing component, the dimethyl silicone oil and the platinum-alkyne complex into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 400 r / min for 40 minutes to form a mixture; The second step is to add the fiber anti-cracking component into the mixture, continue stirring for 3 hours, reduce the pressure to degas, and discharge the material to obtain the organic silicone adhesive. Example 3

[0028] A functional organic silicone adhesive, comprising the following raw materials in parts by weight: 55 parts of terminal vinyl methyl phenyl polysiloxane; 3.5 parts of viscosity-enhancing component; 3 parts of fiber anti-cracking component; 80 parts of dimethyl silicone oil; 1 part of platinum-alkyne complex; The preparation method comprises the following steps: The first step is to add the terminal vinyl methyl phenyl polysiloxane, the viscosity-increasing component, the dimethyl silicone oil and the platinum-alkyne complex into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 500 r / min for 30 minutes to form a mixture; The second step is to add the fiber anti-cracking component into the mixture, continue stirring for 4 hours, reduce the pressure to degas, and discharge the material to obtain the organic silicone adhesive.

[0029] Comparative Example 1 A functional organic silicone adhesive, comprising the following raw materials in parts by weight: 52 parts of terminal vinyl methyl phenyl polysiloxane; 2.5 parts of fiber anti-cracking component; 65 parts of dimethyl silicone oil; 0.6 parts of platinum-alkyne complex; The preparation method comprises the following steps: The first step is to add terminal vinyl methyl phenyl polysiloxane, dimethyl silicone oil and platinum-alkyne complex into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 400 r / min for 40 minutes to form a mixture; The second step is to add the fiber anti-cracking component into the mixture, continue stirring for 3 hours, reduce the pressure to degas, and discharge the material to obtain the organic silicone adhesive.

[0030] Comparative Example 2 A functional organic silicone adhesive, comprising the following raw materials in parts by weight: 52 parts of terminal vinyl methyl phenyl polysiloxane; 3.5 parts of viscosity-enhancing component; 2.5 parts of palm fiber; 65 parts of dimethyl silicone oil; 0.6 parts of platinum-alkyne complex; The preparation method comprises the following steps: The first step is to add the terminal vinyl methyl phenyl polysiloxane, the viscosity-increasing component, the dimethyl silicone oil and the platinum-alkyne complex into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 400 r / min for 40 minutes to form a mixture; The second step is to add palm fiber into the mixture, continue stirring for 3 hours, reduce the pressure to degas, and discharge the mixture to obtain the silicone adhesive.

[0031] Comparative Example 3 A functional organic silicone adhesive, comprising the following raw materials in parts by weight: 52 parts of terminal vinyl methyl phenyl polysiloxane; 3.5 parts of viscosity-enhancing component; 65 parts of dimethyl silicone oil; 0.6 parts of platinum-alkyne complex; The preparation method comprises the following steps: Add terminal vinyl methyl phenyl polysiloxane, viscosity-increasing component, dimethyl silicone oil and platinum-alkyne complex into a mixer, start stirring, mechanically stir and mix at a stirring rate of 400 r / min for 40 minutes, then reduce pressure to degas, discharge, and obtain an organic silicone adhesive.

[0032] Test Case According to HB 5164-1981, the shear strength of silicone adhesive is tested; The organic silicone adhesive in the embodiment and the comparative example was coated on a clean glass plate and cured at a temperature of 100° C. After it was completely cured, the anti-cracking performance of the adhesive film was measured using a thermal shock test chamber at -40° C. to 120° C. for 168 hours. The test results are shown in the table below:

[0033] From the analysis and test results, it can be seen that the organic silicone adhesive prepared by adding the viscosity-enhancing component in Preparation Example 1 of the present invention and the fiber anti-cracking component in Preparation Example 2 at the same time has significantly higher bonding performance and anti-cracking performance.

[0034] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a functional organic silicone adhesive, characterized in that: The organic silicone adhesive comprises the following raw materials in parts by weight: 50-55 parts of terminal vinyl methyl phenyl polysiloxane; 2-3.5 parts of viscosity-increasing component; 1-3 parts of fiber anti-cracking component; 60-80 parts of dimethyl silicone oil; Catalyst 0.5-1 part; The preparation method comprises the following steps: The first step is to add the terminal vinyl methyl phenyl polysiloxane, the viscosity-increasing component, the dimethyl silicone oil and the catalyst into a mixer, start stirring, and mechanically stir and mix at a stirring rate of 300-500 r / min for 30-60 minutes to form a mixture; The second step is to add the fiber anti-cracking component into the mixture, continue stirring for 2-4 hours, reduce the pressure to degas, and discharge the material to obtain the organic silicone adhesive.

2. The method for preparing a functional organic silicone adhesive according to claim 1, characterized in that: The specific preparation method of the viscosity-increasing component is as follows: Glucose and dimethyl sulfoxide are added to a polymerization kettle, nitrogen is passed through for protection, stirring is started, and after a uniform precursor liquid is formed, an alkaline hydroxide aqueous solution is added to the polymerization kettle. After the addition is completed, the temperature is raised to 50-60°C and stirred for 20-30 minutes. Then, 3,4-dichloro-1-butene is added to the polymerization kettle. After the addition is completed, the temperature is further raised to 80-90°C and maintained under stirring for 8-12 hours. The nitrogen is removed, the solvent is evaporated and removed, the temperature is lowered and the material is discharged. The product is collected to obtain a viscosity-increasing component.

3. The method for preparing a functional organic silicone adhesive according to claim 2, characterized in that: The alkaline hydroxide is sodium hydroxide or potassium hydroxide.

4. The method for preparing a functional organic silicone adhesive according to claim 2, characterized in that: The mass fraction of the alkaline hydroxide aqueous solution is 10-25%.

5. The method for preparing a functional organic silicone adhesive according to claim 2, characterized in that: The molar ratio of glucose to 3,4-dichloro-1-butene is 1:

1.

6. The method for preparing a functional organic silicone adhesive according to claim 1, characterized in that: The specific preparation method of the fiber anti-cracking component is as follows: The palm fiber treated with alkali is added to toluene, and ultrasonically dispersed for 30-60 minutes to form a uniform dispersion. Methyldichlorosilane is then added to the dispersion. After the addition is completed, nitrogen is introduced for protection. The temperature is raised to 70-80°C, and after stirring for 1-2 hours, the temperature is lowered to 50-55°C. A branching agent and an alkaline catalyst are continuously added. After the addition is completed, the temperature is further raised to 60-70°C, and stirring is continued for 6-9 hours. The material is cooled and discharged, and the solid material is separated by centrifugation. The fiber anti-cracking component can be obtained after washing and vacuum drying.

7. The method for preparing a functional organic silicone adhesive according to claim 6, characterized in that: The alkali treatment method of the palm fiber is specifically as follows: The palm fiber is soaked in a sodium hydroxide aqueous solution with a mass fraction of 5-20%, stirred at room temperature for 30-60 minutes, taken out, washed with water until neutral, and then vacuum dried.

8. The method for preparing a functional organic silicone adhesive according to claim 6, characterized in that: The branching agent is pentaerythritol or triethanolamine; and the alkaline catalyst is triethylamine.

9. The method for preparing a functional organic silicone adhesive according to claim 1, characterized in that: The catalyst is a platinum-vinyl complex or a platinum-alkyne complex.

10. A functional organic silicone adhesive, characterized in that: The method is prepared according to any one of claims 1 to 9.

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