Two-component optical liquid silica gel

Abstract

The invention relates to the technical field of liquid silica gel preparation, in particular to bi-component optical liquid silica gel. Comprising the following raw materials: a component A: a basic polymer, a reinforcing filler and an additive; the component B comprises a basic polymer, a cross-linking agent and an additive; the preparation method comprises the following steps: putting a multifunctional crosslinking aid, polydimethylsiloxane and vinyl-terminated polydimethylsiloxane into a stirring container, stirring for 10-15 minutes at the speed of 300-500 revolutions per minute to obtain a mixture, slowly adding fumed silica into the stirring container containing the mixture, stirring for 20-30 minutes at the speed of 800-1000 revolutions per minute, finally adding nano calcium carbonate, and stirring for 20-30 minutes at the speed of 800-1000 revolutions per minute to obtain a finished product. And stirring for 20-30 minutes again to obtain a secondary mixture, and sequentially adding the platinum catalyst, the inhibitor and the release agent into the secondary mixture. The viscosity of the system can be reduced, the flowability is improved, and all corners of a mold can be better filled with liquid silica gel.

Description

Technical Field

[0001] The invention relates to the technical field of liquid silicone preparation, in particular to a two-component optical liquid silicone. Background Art

[0002] With the rapid development of optical technology in numerous fields, such as consumer electronics (e.g., mobile phone cameras, camera lenses, etc.), automotive lighting and sensing (e.g., headlight lenses, sensor protective covers, etc.), medical equipment (e.g., endoscope lenses, optical testing instruments, etc.), and industrial optical systems (e.g., optical components of laser processing equipment, projector lenses, etc.), the performance requirements for optical components are becoming increasingly stringent. As a key optical material, optical liquid silicone rubber plays an important role in these fields, and its quality and performance directly affect the overall performance and reliability of the optical system.

[0003] Currently available two-component optical liquid silicone rubber is typically prepared by reacting the vinyl-terminated polydimethylsiloxane in component A with the hydrogen-containing polydimethylsiloxane in component B. This results in a fast curing rate and is difficult to control. Due to the lack of a crosslinking agent to regulate the reaction process, the reaction can proceed rapidly after components A and B are mixed, resulting in a short operating time. This can prevent the liquid silicone from fully filling the fine structures of the mold before the pouring or molding process is completed, resulting in the lens's shape and dimensional accuracy not meeting the requirements. Furthermore, due to the rapid curing, bubbles may form within the silicone rubber. When light passes through optical components containing bubbles, it will refract and scatter, reducing the product's transparency and optical uniformity, and thus degrading the performance of the optical component, thereby affecting the quality of the liquid silicone rubber.

[0004] Therefore, there is an urgent need for a two-component optical liquid silicone to solve the existing technical problems. Summary of the Invention

[0005] The object of the present invention is to provide a two-component optical liquid silicone rubber to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides a two-component optical liquid silicone rubber comprising the following raw materials:

[0007] Component A: base polymer (polydimethylsiloxane: 50-80 parts, vinyl-terminated polydimethylsiloxane: 10-30 parts), reinforcing filler (fumed silica: 5-15 parts, nano-calcium carbonate: 3-10 parts), additives (platinum catalyst: 0.1-0.5 parts, inhibitor: 0.05-0.2 parts, release agent: 0.5-2 parts);

[0008] Component B: base polymer (hydrogen-containing polydimethylsiloxane: 60-90 parts), crosslinking agent (methyl hydrogen silicone oil: 10-30 parts), additives (inhibitor: 0.05-0.2 parts, pigment: 0.1-2 parts);

[0009] Multifunctional cross-linking auxiliary agent (organic silicon compound containing silicon hydrogen and allyl functional groups: 0.5% to 2% of the total mass of liquid silica gel).

[0010] As a further improvement of the present technical solution, the preparation method of the two-component optical liquid silicone comprises the following steps:

[0011] S1. Stirring the base polymer of component A: polydimethylsiloxane and vinyl-terminated polydimethylsiloxane are placed in a stirring container to obtain a mixture;

[0012] S2. Add reinforcing filler and stir: slowly add fumed silica to the stirring container containing the mixture, and finally add nano calcium carbonate to obtain a secondary mixture;

[0013] S3. Add additives and stir: add the platinum catalyst, inhibitor and release agent to the secondary mixture in sequence to obtain the final mixture of component A, and place the container of the final mixture in a vacuum drying oven;

[0014] S4. Mixing the base polymer of component B: placing hydrogen polydimethylsiloxane and methyl hydrogen silicone oil in a mixing container to obtain a mixture;

[0015] S5. Add additives and stir: Add the inhibitor and pigment to the mixture to obtain a final mixture of component B, and place the container of the final mixture in a vacuum drying oven;

[0016] S6. Mixing and stirring component A, component B and a multifunctional crosslinking auxiliary agent: The final mixture of component A and the final mixture of component B are mixed in a stirring container, and an organosilicon compound with silicon hydrogen and allyl functional groups is added to obtain liquid silicone rubber, which is poured into a pre-prepared optical mold.

[0017] As a further improvement of the present technical solution, the stirring speed of the stirrer in S1 is 300 to 500 rpm, and the stirring time is 10 to 15 minutes.

[0018] As a further improvement of the present technical solution, the stirring speed of the stirrer in S2 is 800 to 1000 rpm, the stirring time is 20 to 30 minutes, and the stirring speed remains unchanged after the addition of nano-calcium carbonate, and the stirring is also within 20 to 30 minutes.

[0019] As a further improvement of the present technical solution, the stirring speed of the stirrer in S3 is 500 to 700 rpm for 10 to 15 minutes, the vacuum degree of the stirrer is -0.08 to -0.1 MPa, and the vacuuming time is 10 to 20 minutes.

[0020] As a further improvement of the present technical solution, the stirring speed of the stirrer in S4 is 400 to 600 rpm, and the stirring time is 10 to 15 minutes.

[0021] As a further improvement of the present technical solution, the stirring speed of the stirrer in S5 is 400 to 600 rpm, the stirring is 10 to 15 minutes, the vacuum degree of the stirrer is -0.08 to -0.1 MPa, and the vacuuming time is 10 to 20 minutes.

[0022] As a further improvement of the present technical solution, the stirring speed of the stirrer in S6 is 800-1000 rpm, stirring is carried out for 3-5 minutes, the temperature is controlled at 60°C-100°C, and the humidity is controlled at 40-60% for curing.

[0023] As a further improvement of the present technical solution, the inhibitors in components A and B are acetylenic alcohol compounds, the platinum catalyst in component A is chloroplatinic acid and its complex, and the hydrogenated polydimethylsiloxane is an allyl-terminated polysiloxane.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. This two-component optical liquid silicone rubber, by adding silicone compounds with silicon hydrogen and allyl functional groups, can react simultaneously with the vinyl-terminated polydimethylsiloxane in component A and the hydrogen-containing polydimethylsiloxane in component B, which can adjust the crosslinking density and optimize the network structure of the liquid silicone rubber. During the curing process, its allyl group can undergo addition reaction with the vinyl group in the vinyl-terminated polydimethylsiloxane, and at the same time, the silicon hydrogen bond can participate in the crosslinking reaction with the hydrogen-containing polydimethylsiloxane, which can make the silicone rubber network more uniform and compact, thereby improving the strength, elasticity and tear resistance of the silicone rubber. It can also improve the rheological properties of the liquid silicone rubber, making it easier to operate during the mixing and molding process, and can reduce the viscosity of the system, improve the fluidity, and ensure that the liquid silicone rubber better fills every corner of the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the preparation process of the two-component optical liquid silicone rubber of the present invention. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] See also Figure 1 shown

[0029] Example 1:

[0030] A two-component optical liquid silicone rubber, comprising the following raw materials: component A: base polymer (polydimethylsiloxane: 50 parts, vinyl-terminated polydimethylsiloxane: 10 parts), reinforcing filler (fumed silica: 5 parts, nano-calcium carbonate: 3 parts), additives (platinum catalyst: 0.1 parts, inhibitor: 0.05 parts, release agent: 0.5 parts);

[0031] Component B: base polymer (hydrogen-containing polydimethylsiloxane: 60 parts), crosslinking agent (methyl hydrogen silicone oil: 10 parts), additives (inhibitor: 0.05 parts, pigment: 0.1 parts);

[0032] A multifunctional crosslinking agent (organosilicon compound containing silane and allyl functional groups: 0.5% to 2% of the total mass of the liquid silica gel). The total mass of the above components A and B is 138.8 parts. 0.5% of the total mass of the liquid silica gel is taken, which is 0.694 parts.

[0033] Polydimethylsiloxane and vinyl-terminated polydimethylsiloxane are placed in a stirring container and stirred at 300 rpm for 10 minutes to obtain a mixture. Fumed silica is slowly added to the stirring container containing the mixture and stirred at 800 rpm for 20 minutes. Finally, nano-calcium carbonate is added and stirred again for 20 minutes to obtain a secondary mixture. The platinum catalyst, inhibitor and release agent are sequentially added to the secondary mixture and stirred at 500 rpm for 10 minutes to obtain a final mixture of component A. The container of the final mixture is placed in a vacuum drying oven, the vacuum degree is set to -0.08 MPa, and the vacuuming time is 10 minutes;

[0034] Hydrogen polydimethylsiloxane and methyl hydrogen silicone oil are placed in a stirring container and stirred at 400 rpm for 10 minutes to obtain a mixture. The inhibitor and pigment are added to the mixture, and the stirring speed is maintained at 400 rpm and stirred for 10 minutes to obtain a final mixture of component B. The container of the final mixture is placed in a vacuum drying oven, the vacuum degree is set to -0.08 MPa, and the vacuum time is 10 minutes. The final mixture of component A and the final mixture of component B are mixed in a stirring container, and an organosilicon compound with silicon hydrogen and allyl functional groups is added. The mixture is rapidly stirred at 800 rpm for 3 minutes to obtain liquid silicone rubber, which is poured into a pre-prepared optical mold and cured at a temperature of 60°C and a humidity of 40% to obtain a two-component optical liquid silicone rubber. The test data are shown in Table 1.

[0035] Example 2:

[0036] A two-component optical liquid silicone rubber, comprising the following raw materials: component A: base polymer (polydimethylsiloxane: 65 parts, vinyl-terminated polydimethylsiloxane: 20 parts), reinforcing filler (fumed silica: 10 parts, nano-calcium carbonate: 7 parts), additives (platinum catalyst: 0.3 parts, inhibitor: 0.1 parts, release agent: 1 part);

[0037] Component B: base polymer (hydrogen-containing polydimethylsiloxane: 75 parts), crosslinking agent (methyl hydrogen silicone oil: 20 parts), additives (inhibitor: 0.1 parts, pigment: 1 part);

[0038] A multifunctional crosslinking agent (organosilicon compound containing silane and allyl functional groups: 0.5% to 2% of the total mass of the liquid silica gel), the total mass of the above components A and B is 199.5 parts, and 1% of the total mass of the liquid silica gel is taken, which is 2 parts;

[0039] Polydimethylsiloxane and vinyl-terminated polydimethylsiloxane are placed in a stirring container and stirred at 400 rpm for 12 minutes to obtain a mixture. Fumed silica is slowly added to the stirring container containing the mixture and stirred at 900 rpm for 25 minutes. Finally, nano-calcium carbonate is added and stirred again for 25 minutes to obtain a secondary mixture. The platinum catalyst, inhibitor and release agent are sequentially added to the secondary mixture and stirred at 600 rpm for 12 minutes to obtain a final mixture of component A. The container of the final mixture is placed in a vacuum drying oven, the vacuum degree is set to -0.09 MPa, and the vacuuming time is 15 minutes;

[0040] Hydrogen polydimethylsiloxane and methyl hydrogen silicone oil are placed in a stirring container and stirred at 500 rpm for 12 minutes to obtain a mixture. The inhibitor and pigment are added to the mixture, and the stirring speed is maintained at 500 rpm and stirred for 12 minutes to obtain a final mixture of component B. The container of the final mixture is placed in a vacuum drying oven, the vacuum degree is set to -0.09 MPa, and the vacuum time is 15 minutes. The final mixture of component A and the final mixture of component B are mixed in a stirring container, and an organosilicon compound with silicon hydrogen and allyl functional groups is added. The mixture is rapidly stirred at 900 rpm for 4 minutes to obtain liquid silicone rubber, which is poured into a pre-prepared optical mold and cured at a temperature of 80°C and a humidity of 50% to obtain a two-component optical liquid silicone rubber. The test data are shown in Table 1.

[0041] Example 3:

[0042] A two-component optical liquid silicone rubber, comprising the following raw materials: component A: base polymer (polydimethylsiloxane: 80 parts, vinyl-terminated polydimethylsiloxane: 30 parts), reinforcing filler (fumed silica: 15 parts, nano-calcium carbonate: 10 parts), additives (platinum catalyst: 0.5 parts, inhibitor: 0.2 parts, release agent: 2 parts);

[0043] Component B: base polymer (hydrogen-containing polydimethylsiloxane: 90 parts), crosslinking agent (methyl hydrogen silicone oil: 30 parts), additives (inhibitor: 0.2 parts, pigment: 2 parts);

[0044] A multifunctional crosslinking agent (organosilicon compound containing silane and allyl functional groups: 0.5% to 2% of the total mass of the liquid silica gel). The total mass of the above components A and B is 259.9 parts, and 2% of the total mass of the liquid silica gel is taken, which is 5.2 parts;

[0045] Polydimethylsiloxane and vinyl-terminated polydimethylsiloxane are placed in a stirring container and stirred at 500 rpm for 15 minutes to obtain a mixture. Fumed silica is slowly added to the stirring container containing the mixture and stirred at 1000 rpm for 30 minutes. Finally, nano-calcium carbonate is added and stirred again for 30 minutes to obtain a secondary mixture. The platinum catalyst, inhibitor and release agent are sequentially added to the secondary mixture and stirred at 700 rpm for 15 minutes to obtain a final mixture of component A. The container of the final mixture is placed in a vacuum drying oven, the vacuum degree is set to -0.1 MPa, and the vacuuming time is 20 minutes;

[0046] Hydrogen polydimethylsiloxane and methyl hydrogen silicone oil are placed in a stirring container and stirred at 600 rpm for 15 minutes to obtain a mixture. The inhibitor and pigment are added to the mixture, and the stirring speed is maintained at 600 rpm and stirred for 15 minutes to obtain a final mixture of component B. The container of the final mixture is placed in a vacuum drying oven, the vacuum degree is set to -0.1 MPa, and the vacuum time is 20 minutes. The final mixture of component A and the final mixture of component B are mixed in a stirring container, and an organosilicon compound with silicon hydrogen and allyl functional groups is added. The mixture is rapidly stirred at 1000 rpm for 5 minutes to obtain liquid silicone rubber, which is poured into a pre-prepared optical mold and cured at a temperature of 100°C and a humidity of 60% to obtain a two-component optical liquid silicone rubber. The test data are shown in Table 1.

[0047] Table 1 Comparison of experimental data of Examples 1-3

[0048] Example 1 Example 2 Example 3 Gel time (min) 20 25 30 <![CDATA[Crosslink density (mol / cm 3 )]]> 1.2 1.4 1.8 Shore hardness (A) 35 40 45 Tensile strength (MPa) 6 8 10 Elongation at break (%) 450 500 550 Tear strength (kN / m) 18 20 25 Light transmittance (%) 92 95 98 Refractive index 1.42 1.45 1.48

[0049] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A two-component optical liquid silicone rubber, characterized in that: Including the following ingredients: Component A: base polymer (polydimethylsiloxane: 50-80 parts, vinyl-terminated polydimethylsiloxane: 10-30 parts), reinforcing filler (fumed silica: 5-15 parts, nano-calcium carbonate: 3-10 parts), additives (platinum catalyst: 0.1-0.5 parts, inhibitor: 0.05-0.2 parts, release agent: 0.5-2 parts); Component B: base polymer (hydrogen-containing polydimethylsiloxane: 60-90 parts), crosslinking agent (methyl hydrogen silicone oil: 10-30 parts), additives (inhibitor: 0.05-0.2 parts, pigment: 0.1-2 parts); Multifunctional cross-linking auxiliary agent (organic silicon compound containing silicon hydrogen and allyl functional groups: 0.5% to 2% of the total mass of liquid silica gel).

2. The two-component optical liquid silicone according to claim 1, characterized in that: The preparation method of the two-component optical liquid silicone comprises the following steps: S1. Stirring the base polymer of component A: polydimethylsiloxane and vinyl-terminated polydimethylsiloxane are placed in a stirring container to obtain a mixture; S2. Add reinforcing filler and stir: slowly add fumed silica to the stirring container containing the mixture, and finally add nano calcium carbonate to obtain a secondary mixture; S3. Add additives and stir: add the platinum catalyst, inhibitor and release agent to the secondary mixture in sequence to obtain the final mixture of component A, and place the container of the final mixture in a vacuum drying oven; S4. Mixing the base polymer of component B: placing hydrogen polydimethylsiloxane and methyl hydrogen silicone oil in a mixing container to obtain a mixture; S5. Add additives and stir: Add the inhibitor and pigment to the mixture to obtain a final mixture of component B, and place the container of the final mixture in a vacuum drying oven; S6. Mixing and stirring component A, component B and a multifunctional crosslinking auxiliary agent: The final mixture of component A and the final mixture of component B are mixed in a stirring container, and an organosilicon compound with silicon hydrogen and allyl functional groups is added to obtain liquid silicone rubber, which is poured into a pre-prepared optical mold.

3. The two-component optical liquid silicone according to claim 2, characterized in that: The stirring speed of the stirrer in S1 is 300 to 500 rpm, and the stirring time is 10 to 15 minutes.

4. The two-component optical liquid silicone according to claim 2, characterized in that: The stirring speed of the stirrer in S2 is 800-1000 rpm, and the stirring time is 20-30 minutes. The stirring speed remains unchanged after the addition of nano-calcium carbonate, and the stirring time is also within 20-30 minutes.

5. The two-component optical liquid silicone according to claim 2, characterized in that: The stirring speed of the stirrer in S3 is 500 to 700 rpm for 10 to 15 minutes, the vacuum degree of the stirrer is -0.08 to -0.1 MPa, and the vacuuming time is 10 to 20 minutes.

6. The two-component optical liquid silicone rubber according to claim 2, characterized in that: The stirring speed of the stirrer in S4 is 400 to 600 rpm, and the stirring time is 10 to 15 minutes.

7. The two-component optical liquid silicone rubber according to claim 2, characterized in that: The stirring speed of the stirrer in S5 is 400 to 600 rpm, stirring for 10 to 15 minutes, the vacuum degree of the stirrer is -0.08 to -0.1 MPa, and the vacuuming time is 10 to 20 minutes.

8. The two-component optical liquid silicone rubber according to claim 2, characterized in that: The stirring speed of the stirrer in S6 is 800-1000 rpm, stirring for 3-5 minutes, and curing under the conditions of temperature controlled at 60° C.-100° C. and humidity controlled at 40-60%.

9. The two-component optical liquid silicone according to claim 2, characterized in that: The inhibitors in the components A and B are acetylenic alcohol compounds, the platinum catalyst in the component A is chloroplatinic acid and its complex, and the hydrogen-containing polydimethylsiloxane is allyl-terminated polysiloxane.

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