A silicone rubber tackifier, a silicone rubber and a method for producing the same

Abstract

The application belongs to the field of silicone rubber, and particularly relates to a silicone rubber tackifier, silicone rubber and a preparation method thereof. The silicone rubber tackifier provided in the application contains multiple epoxy groups and siloxane bonds in a chemical structural formula, which endows the silicone rubber tackifier with good compatibility with silicone rubber, improves the bonding effect between the silicone rubber and a matrix, improves the bonding effect between the silicone rubber and the matrix, and thus solves the technical problem that the viscosity of the addition type silicone rubber in the prior art needs to be improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of silicone rubber, and particularly relates to a silicone rubber tackifier, a silicone rubber and a preparation method thereof. BACKGROUND

[0002] Silicone rubber can be divided into condensation type silicone rubber and addition type silicone rubber. Compared with the condensation type silicone rubber, the addition type silicone rubber has the advantages of no by-products generated in the vulcanization process, small shrinkage, deep vulcanization and the like. In addition, the vulcanized addition type silicone rubber has excellent properties such as moisture resistance, water resistance, cold resistance, heat resistance, ultraviolet resistance, insulation, radiation resistance, weather resistance and ozone resistance. Therefore, the addition type silicone rubber is widely used in the fields of electronic and electrical potting adhesive, liquid injection molding adhesive, mold adhesive and roller adhesive and the like.

[0003] However, the large number of non-polar groups contained in the addition type silicone rubber molecules leads to low surface energy of the addition type silicone rubber molecules, and poor bonding effect on the base material. At present, on the one hand, the surface of the base material can be treated by using a primer. The main function of the primer is to increase the adhesion of the LSR to the contact base material, and at the same time, the surface of the fragile base material is strengthened and the components in the base material that hinder vulcanization are shielded, so as to improve the bonding effect of the addition type silicone rubber on the base material. On the other hand, the addition type silicone rubber is modified to enhance the bonding effect of the addition type silicone rubber on the base material. At present, the method for modifying the addition type silicone rubber includes changing the molecular structure of polysiloxane, introducing monomers with functional groups such as phenyl and ester groups in the synthesis of polysiloxane, changing the molecular structure of the addition type silicone rubber itself, and improving the adhesion performance of the silicone rubber. Since the actual production process is relatively complex and the cost is relatively high, the application thereof is limited. In addition, an adhesion promoter can be added in the vulcanization process of the addition type silicone rubber to improve the self-adhesion performance of the addition type silicone rubber. However, the traditional adhesion promoter for the addition type silicone rubber has poor compatibility with the silicone rubber, and phase separation is prone to occur. The bonding layer between the addition type silicone rubber and the base material is easily damaged, which limits the improvement of the adhesion performance of the addition type silicone rubber by the adhesion promoter, and the viscosity of the addition type silicone rubber needs to be improved.

[0004] The present application designs and synthesizes an organosiloxane having multiple epoxy groups. Compared with the traditional adhesion promoter, the adhesion promoter of the present application has multiple epoxy groups and siloxane bonds, can form a firm chemical bond with the base material (such as aluminum sheet, copper sheet and the like), has better compatibility with the organic silicone resin, and will not cause phase separation. In addition, the adhesion promoter can avoid damage to the bonding layer. SUMMARY

[0005] Therefore, the present application provides a silicone rubber tackifier, a silicone rubber and a preparation method thereof, which are used to solve the technical problem that the viscosity of the addition type silicone rubber needs to be improved in the prior art.

[0006] The first aspect of the present application provides a silicone rubber tackifier, and a chemical structure of the silicone rubber tackifier is shown as Formula I:

[0007]

[0008] In Formula I, R1 is -Si(OCH3)2(CH2)3OCH2R5,

[0009] R2 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H;

[0010] R3 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H;

[0011] R4 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H;

[0012] R5 is

[0013] The second aspect of the present application provides a preparation method of a silicone rubber tackifier, and the preparation method comprises the following steps:

[0014] Step S1, dropping an epoxy-containing siloxane compound into a monohydric alcohol solvent of a polyol to obtain an epoxy-containing siloxane solution;

[0015] Step S2, adding an organic titanate catalyst into the epoxy-containing siloxane solution to react to obtain a silicone rubber tackifier;

[0016] In Step S2, the temperature of the reaction is 60-130℃.

[0017] Preferably, in Step S2, the reaction time is 2-18h, and the vacuum degree is 0.01-0.9kPa.

[0018] Preferably, in Step S1, the molar ratio of the polyol and the siloxane compound in the epoxy-containing siloxane solution is 1:2-1:10.

[0019] Preferably, in Step S1, the epoxy-containing siloxane compound comprises any one or more than one of 3-(2,3-epoxypropyl)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propylmethyldimethoxysilane, 3-(2,3-epoxypropane propyl triethoxysilane, 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0020] Preferably, in step S1, the polyhydric alcohol includes any one or more of ethylene glycol, glycerol, pentaerythritol, trimethylol ethane, xylitol, sorbitol.

[0021] Preferably, in step S1, the monohydric alcohol solvent includes any one or more of methanol, ethanol, isopropyl alcohol.

[0022] Preferably, in step S2, the organic titanate catalyst includes any one or more of tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetra-t-butyl titanate, and diisopropyl titanate bis(acetylacetone).

[0023] The third aspect of the present application provides a silicone rubber, and the composition of the silicone rubber includes a silicone rubber tackifier.

[0024] It should be noted that the silicone rubber provided by the present application is an addition type silicone rubber.

[0025] The fourth aspect of the present application provides a preparation method of a silicone rubber, and the preparation method includes the following steps:

[0026] Step S3, stirring the silicone rubber tackifier, silicone oil, filler, hexamethyl disilazane, and ethynylcyclohexanol to obtain a to-be-added silicone rubber solution;

[0027] Step S4, adding a platinum gold catalyst solution to the to-be-added silicone rubber solution to perform a silicone rubber addition reaction to obtain a silicone rubber;

[0028] In step S4, the temperature of the silicone rubber addition reaction is 110-150°C.

[0029] Preferably, in step S4, the time of the silicone rubber addition reaction is 1-5h.

[0030] Preferably, in step S3, the filler is fumed white carbon black.

[0031] Preferably, in step S4, the platinum gold catalyst solution is a Karstedt catalyst.

[0032] The concentration of the Karstedt catalyst is 2000-5000ppm.

[0033] Preferably, the mass ratio of the silicone rubber tackifier, silicone oil, filler, hexamethyl disilazane, ethynylcyclohexanol, and platinum gold catalyst is 8-60:700-1000:100-300:20-75:0.01-0.5:0.5-20.

[0034] In summary, the present application provides a silicone rubber tackifier, a silicone rubber and a preparation method thereof. The silicone rubber tackifier contains an epoxy group and a siloxane bond in the chemical structural formula. The epoxy group and the siloxane bond give the silicone rubber tackifier good compatibility with the silicone rubber, so that the silicone rubber tackifier is difficult to separate from the silicone rubber, the bonding layer between the silicone rubber and the substrate is stable, and the bonding effect between the silicone rubber and the substrate is improved. In addition, the silicone rubber tackifier provided by the present application contains multiple epoxy groups and siloxane bonds, which can further improve the good compatibility of the silicone rubber tackifier with the silicone rubber and improve the bonding effect between the silicone rubber and the substrate. Therefore, the silicone rubber tackifier provided by the present application solves the technical problem that the viscosity of the addition type silicone rubber in the prior art needs to be improved. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0036] Figure 1 The infrared spectrum of the silicone rubber tackifier provided for Embodiment 2 of the present application;

[0037] Figure 2 The infrared spectrum of the silicone rubber tackifier provided for Embodiment 3 of the present application;

[0038] Figure 3 The infrared spectrum of the silicone rubber tackifier provided for Embodiment 4 of the present application;

[0039] Figure 4 The preparation reaction principle diagram of the silicone rubber tackifier provided for Embodiment 2 of the present application;

[0040] Figure 5 The preparation reaction principle diagram of the silicone rubber tackifier provided for Embodiment 3 of the present application;

[0041] Figure 6 The preparation reaction principle diagram of the silicone rubber tackifier provided for Embodiment 4 of the present application. DETAILED DESCRIPTION

[0042] The present application provides a silicone rubber tackifier, a silicone rubber and a preparation method thereof, which are used to solve the technical problem that the viscosity of the addition type silicone rubber in the prior art needs to be improved.

[0043] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0044] Embodiment 1

[0045] The embodiment of the present application provides a silicone rubber tackifier, and a chemical structural formula of the silicone rubber tackifier is shown as formula I.

[0046]

[0047] In formula I, R1 is -Si(OCH3)2(CH2)3OCH2R5,

[0048] R2 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H;

[0049] R3 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H;

[0050] R4 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H;

[0051] R5 is

[0052] As can be seen from formula I, the chemical structural formula of the silicone rubber tackifier contains an epoxy group and a siloxane bond, which increases the polarity of the silicone rubber, is conducive to bonding with various metal substrates, and the epoxy group and the siloxane bond are similar to the structure of the silicone rubber, which endows the silicone rubber tackifier with good compatibility with the silicone rubber, so that the silicone rubber tackifier is difficult to separate from the silicone rubber, the bonding layer between the silicone rubber and the substrate is stable, the bonding effect between the silicone rubber and the substrate is greatly improved, and since the epoxy group and the siloxane bond contained are multiple, the good compatibility of the silicone rubber tackifier with the silicone rubber is further improved, and the bonding effect between the silicone rubber and the substrate is improved. Therefore, the silicone rubber tackifier provided by the present application solves the technical problem that the viscosity of the addition type silicone rubber in the prior art needs to be improved.

[0053] Embodiment 2

[0054] The embodiment of the present application provides a preparation method of a silicone rubber tackifier, which comprises the steps of preparing an epoxy group-containing siloxane solution and reacting to prepare the silicone rubber tackifier.

[0055] The step of preparing the siloxane solution containing an epoxy group comprises adding 30 g of glycerol and 400 mL of anhydrous methanol into a reactor with a thermometer and a condenser, stirring uniformly, and adding 200 g of (2,3-epoxypropoxy) propyl trimethoxysilane dropwise to obtain the siloxane solution containing an epoxy group;

[0056] The step of preparing the silicone rubber tackifier by reaction comprises adding 3 g of tetrabutyl titanate into the siloxane solution containing an epoxy group, reacting at 70 DEG C for about 2 h, and continuously reacting for 3 h under a vacuum degree of 0.3 kPa to obtain the silicone rubber tackifier. Figure 4 The reaction principle of preparing the silicone rubber tackifier is shown in Figure 1 , and the infrared spectrum of the silicone rubber tackifier is shown in

[0057] Example 3

[0058] The embodiment of the present application provides a preparation method of a silicone rubber tackifier, and the preparation method comprises the steps of preparing a siloxane solution containing an epoxy group and reacting a silicone rubber tackifier.

[0059] The step of preparing the siloxane solution containing an epoxy group comprises adding 25 g of pentaerythritol and 400 mL of anhydrous methanol into a reactor with a thermometer and a condenser, stirring uniformly, and adding 170 g of (2,3-epoxypropoxy) propyl trimethoxysilane dropwise to obtain the siloxane solution containing an epoxy group.

[0060] The step of preparing the silicone rubber tackifier by reaction comprises adding 2.5 g of tetrabutyl titanate into the siloxane solution containing an epoxy group, reacting at 70 DEG C for about 2 h, and continuously reacting for 3 h under a vacuum degree of 0.5 kPa to obtain the silicone rubber tackifier. Figure 5 The reaction principle of preparing the silicone rubber tackifier is shown in , and the infrared spectrum of the silicone rubber tackifier is shown in

[0061] Example 4

[0062] The embodiment of the present application provides a preparation method of a silicone rubber tackifier, and the preparation method comprises the steps of preparing a siloxane solution containing an epoxy group and reacting a silicone rubber tackifier.

[0063] The step of preparing the siloxane solution containing an epoxy group comprises adding 20 g of trimethylol ethane and 150 mL of anhydrous methanol into a reactor with a thermometer and a condenser, stirring uniformly, and adding 120 g of (2,3-epoxypropoxy) propyl trimethoxysilane dropwise to obtain the siloxane solution containing an epoxy group.

[0064] The step of preparing the silicone rubber tackifier by reaction includes adding 2g of tetrabutyl titanate into the solution containing the epoxy group, reacting at 70℃ for about 2h, and continuously reacting for 3h under the condition of 0.4kPa vacuum degree, to obtain the silicone rubber tackifier, and the reaction principle of preparing the silicone rubber tackifier is shown in Figure 6 The infrared spectrum of the silicone rubber tackifier is shown in Fig. 3.

[0065] Example 5

[0066] The embodiment of the present application provides a silicone rubber preparation method, and the preparation method includes the steps of preparing a silicone rubber solution to be added and preparing silicone rubber by reaction.

[0067] The step of preparing the silicone rubber solution to be added includes adding 720 parts of 2000cp vinyl silicone oil, 250 parts of 200 specific surface area fumed white carbon black, 50 parts of hexamethyldisilazane, 30 parts of 0.5% hydrogen-containing silicone oil, 0.1 part of ethynylcyclohexanol, and 10 parts of the silicone rubber tackifier provided in the embodiment 2 into a kneader, and uniformly kneading at room temperature to obtain the silicone rubber solution to be added.

[0068] The step of preparing the silicone rubber by reaction includes adding 1 part of 3000ppm Karstedt catalyst into the silicone rubber solution to be added, uniformly stirring, and placing the silicone rubber solution to be added into a vacuum drying box at room temperature, fully exhausting bubbles, and finally curing for 2h at 120℃ to form.

[0069] Example 6

[0070] The embodiment of the present application provides a silicone rubber preparation method, and the preparation method includes the steps of preparing a silicone rubber solution to be added and preparing silicone rubber by reaction.

[0071] The step of preparing the silicone rubber solution to be added includes adding 740 parts of 2000cp vinyl silicone oil, 260 parts of 200 specific surface area fumed white carbon black, 55 parts of hexamethyldisilazane, 32 parts of 0.5% hydrogen-containing silicone oil, 0.12 part of ethynylcyclohexanol, and 15 parts of the silicone rubber tackifier provided in the embodiment 3 into a kneader, and uniformly kneading at room temperature to obtain the silicone rubber solution to be added.

[0072] The step of preparing the silicone rubber by reaction includes adding 1.2 parts of 3000ppm Karstedt catalyst into the silicone rubber solution to be added, uniformly stirring, and placing the silicone rubber solution to be added into a vacuum drying box at room temperature, fully exhausting bubbles, and finally curing for 2h at 130℃ to form.

[0073] Example 7

[0074] The embodiment of the present application provides a silicone rubber preparation method, and the preparation method includes the steps of preparing a silicone rubber solution to be added and preparing silicone rubber by reaction.

[0075] The step of preparing the solution of the silicone rubber to be added includes adding 720 parts of 2000 cp vinyl silicone oil, 250 parts of 200 specific surface area fumed white carbon black, 50 parts of hexamethyldisilazane, 30 parts of 0.5% hydrogen-containing silicone oil, and 0.1 part of ethynylcyclohexanol into a kneader and kneading uniformly at room temperature to obtain the solution of the silicone rubber to be added.

[0076] The step of preparing the silicone rubber by reaction includes adding 1 part of 3000 ppm Karstedt catalyst into the solution of the silicone rubber to be added, stirring uniformly, placing it into a vacuum drying box at room temperature, fully releasing bubbles, and finally curing at 120°C for 2 hours to form a shape.

[0077] Comparative Example 1

[0078] The present application provides a silicone rubber preparation method, the step of preparing the solution of the silicone rubber to be added and the step of preparing the silicone rubber by reaction.

[0079] The step of preparing the solution of the silicone rubber to be added includes adding 720 parts of 2000 cp vinyl silicone oil, 250 parts of 200 specific surface area fumed white carbon black, 50 parts of hexamethyldisilazane, 30 parts of 0.5% hydrogen-containing silicone oil, and 0.1 part of ethynylcyclohexanol into a kneader and kneading uniformly at room temperature to obtain the solution of the silicone rubber to be added.

[0080] The step of preparing the silicone rubber by reaction includes adding 1 part of 3000 ppm Karstedt catalyst into the solution of the silicone rubber to be added, stirring uniformly, placing it into a vacuum drying box at room temperature, fully releasing bubbles, and finally curing at 120°C for 2 hours to form a shape.

[0081] Comparative Example 2

[0082] The present application provides a silicone rubber preparation method, the step of preparing the solution of the silicone rubber to be added and the step of preparing the silicone rubber by reaction.

[0083] The step of preparing the solution of the silicone rubber to be added includes adding 730 parts of 2000 cp vinyl silicone oil, 255 parts of 200 specific surface area fumed white carbon black, 53 parts of hexamethyldisilazane, 32 parts of 0.5% hydrogen-containing silicone oil, 0.1 part of ethynylcyclohexanol, and 10 parts of TAC-03 silicone rubber tackifier into a kneader and kneading uniformly at room temperature to obtain the solution of the silicone rubber to be added.

[0084] The step of preparing the silicone rubber by reaction includes adding 1 part of 3000 ppm Karstedt catalyst into the solution of the silicone rubber to be added, stirring uniformly, placing it into a vacuum drying box at room temperature, fully releasing bubbles, and finally curing at 120°C for 2 hours to form a shape.

[0085] Test Example 1

[0086] The test example provides the silicone rubber test method provided by Examples 5-7 and Comparative Example 1, and tests including viscosity test and mechanical property test.

[0087] The viscosity test includes viscosity test of the silicone rubber and bonding tensile shear strength test of the silicone rubber and copper plate, and the mechanical property test includes tensile strength, elongation at break of the silicone rubber and Shore A hardness test of the silicone rubber.

[0088] The viscosity of the silicone rubber is determined according to GB / T 2794-1995, the bonding tensile shear strength of the silicone rubber and copper plate is determined according to GB / T 13936-1992, the tensile strength and elongation at break of the silicone rubber are determined according to GB / T 528-2009, and the Shore A hardness of the silicone rubber is determined according to GB / T 531-2008. The viscosity test and the mechanical property test are shown in Table 1.

[0089]

[0090] Table 1

[0091] As can be seen from the viscosity test data shown in Table 1, the bonding shear strength of the silicone rubber provided by Comparative Example 1 and copper plate is 0.41 MPa, the bonding shear strength of the silicone rubber provided by Comparative Example 2 and copper plate is 0.90 MPa, and the bonding shear strength of the silicone rubber provided by Examples 5-6 and copper plate is 0.95-1.21 MPa, which is greater than the bonding tensile shear strength of the silicone rubber provided by Comparative Examples 1-2 and copper plate. This shows that the silicone rubber tackifier provided by Examples 5-6 not only has the active groups on the surface of the conventional silicone rubber tackifier and the substrate to interact, thereby imparting the addition type silicone rubber with good self-adhesion properties, but also the good compatibility of the multiple epoxy groups and siloxane bonds in the silicone rubber tackifier with the silicone rubber, making it difficult for the silicone rubber tackifier to phase separate from the silicone rubber, and the bonding layer between the silicone rubber and the substrate is stable, thereby greatly improving the bonding effect between the silicone rubber and the substrate.

[0092] The above examples are only used to illustrate the technical solutions of the present application, but not to 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 they can still modify the technical solutions described 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. A silicone rubber tackifier, characterized by, The chemical structure of the silicone rubber tackifier is shown as formula I: Formula I; In formula I, R1 is -Si(OCH3)2(CH2)3OCH2R5; R2 is -CH2OSi(OCH3)2(CH2)3OCH2R5; R3 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H; R4 is -CH2OSi(OCH3)2(CH2)3OCH2R5 or CH2OH or H; R5 is .

2. A process for the preparation of a silicone rubber tackifier as claimed in claim 1, characterized in that, The preparation method comprises the steps of: Step S1, dropping the epoxy-containing siloxane compound into the monohydric alcohol solution of the polyol to obtain an epoxy-containing siloxane solution; Step S2, adding an organic titanate catalyst to the epoxy-containing siloxane solution to react to obtain a silicone rubber tackifier; In step S2, the temperature of the reaction is 60-130°C. The epoxy-containing siloxane compound is selected from 3-(2,3-epoxypropoxy)propyl trimethoxysilane; The polyol is selected from pentaerythritol.

3. The method for preparing a silicone rubber tackifier according to claim 2, characterized in that, In step S2, the reaction time is 2-18h, and the vacuum degree is 0.01-0.9 kPa.

4. The method for preparing a silicone rubber tackifier according to claim 2, characterized in that, In step S1, the molar ratio of the polyol and the siloxane compound in the epoxy-containing siloxane solution is 1:2-1:

10.

5. The method for preparing a silicone rubber tackifier according to claim 2, characterized in that, In step S1, the monohydric alcohol includes any one or more of methanol, ethanol, and isopropyl alcohol.

6. The method for preparing a silicone rubber tackifier according to claim 2, characterized in that, In step S2, the organic titanate catalyst includes any one or more of tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetra-t-butyl titanate, and di(acetylacetone) titanium diisopropyl titanate.

7. A silicone rubber characterised in that, The silicone rubber comprises the silicone rubber tackifier of claim 1 or the silicone rubber tackifier prepared by the preparation method of any one of claims 2-6.

8. A process for the production of a silicone rubber as claimed in claim 7, characterised in that, The preparation method comprises the steps of: Step S3, stirring the silicone rubber tackifier, silicone oil, filler, hexamethyldisilazane, and ethynylcyclohexanol to obtain a to-be-added silicone rubber solution; Step S4, dropping a platinum gold catalyst solution into the to-be-added silicone rubber solution to perform a silicone rubber addition reaction to obtain a silicone rubber; In step S4, the temperature of the silicone rubber addition reaction is 110-150°C.

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