Silicone rubber curing catalyst and preparation method thereof

Abstract

The invention relates to the related technical field of silicone rubber, in particular to a silicone rubber curing catalyst and a preparation method thereof, the silicone rubber curing catalyst comprises a platinum catalyst, vinyl silicone oil and a pigment, the proportion of the platinum catalyst to the vinyl silicone oil to the pigment is 3: 5: 2, the viscosity of the vinyl silicone oil is 1000-5000 mPa.s, and the pigment is a high-temperature-resistant organic pigment. The method has the advantages that the composition of the catalyst is adjusted by matching the silicone oil with the pigment, so that the catalyst components are safe, and the curing speed of the liquid silicone rubber can be accelerated.

Description

Technical Field

[0001] The present invention relates to the technical field of silicone rubber, and specifically refers to a catalyst for curing silicone rubber and a preparation method thereof. Background Art

[0002] Liquid silicone rubber is an organosilicon polymer material in liquid form, composed of low-viscosity linear polysiloxane. It presents a flowing state before curing and can be transformed into an elastic solid through a curing reaction, facilitating molding through processes such as injection and casting, and facilitating the preparation of impression molds of different shapes.

[0003] Currently, the curing of silicone rubber relies on a catalyst to promote the cross-linking reaction. The current catalysts often contain dibutyltin dilaurate, which has certain toxicity and may pose hazards to human health and the environment. Summary of the Invention

[0004] The technical problem to be solved by the present invention is the problem that the dibutyltin dilaurate component contained in the catalyst for curing silicone rubber has certain toxicity.

[0005] To solve the above technical problem, the technical solution provided by the present invention is: A catalyst for curing silicone rubber, which includes a platinum catalyst, vinyl silicone oil, and a pigment. The mixing ratio of the platinum catalyst, vinyl silicone oil, and pigment is: 3:5:2. The viscosity of the vinyl silicone oil is 1000 - 5000 mPa·s, and the pigment is a high-temperature resistant organic pigment.

[0006] A preparation method of a catalyst for curing silicone rubber, which includes the following steps:

[0007] a. Dehydrate the vinyl silicone oil in a vacuum kneader at 80 - 120 °C for 1 - 2 hours, and cool it to room temperature;

[0008] b. Add the platinum catalyst into the vinyl silicone oil in proportion and stir for 30 minutes under nitrogen protection until evenly dispersed;

[0009] c. Fill the paste prepared in step b into tube A and tube B in a ratio of 8:2;

[0010] d. Seal tube A in bottle A, add the pigment into tube B in proportion according to the total paste amount, mix evenly, and then seal it in bottle B;

[0011] e. Store bottle A and bottle B synchronously and mix them for use when needed.

[0012] The present invention has the following advantages: By using the method of mixing silicone oil with pigments to adjust the composition of the catalyst, the catalyst components are safe, without adding toxic and harmful components such as dibutyltin dilaurate, which can protect the physical health of workers as much as possible, and can accelerate the curing speed of liquid silicone rubber. At the same time, the catalyst and pigments are separated by using AB tubes to prevent the pigments from affecting the inactivation of the catalyst. Detailed implementation mode

[0013] The following further describes the present invention in detail with reference to embodiments.

[0014] Embodiment 1

[0015] A catalyst for curing silicone rubber, which includes a platinum catalyst, vinyl silicone oil and pigments. The mixing ratio of the platinum catalyst, vinyl silicone oil and pigments is: 3:5:2. The viscosity of the vinyl silicone oil is 2000 mPa·s. The pigments are high-temperature resistant organic pigments, and the specific components of the pigments are inorganic materials such as metal oxides. According to their colors, they are titanium dioxide (TiO2, white), iron oxide (Fe2O3, red / yellow / black), or organic materials such as phthalocyanine blue, phthalocyanine green, azo red, azo yellow, etc.

[0016] A preparation method of a catalyst for curing silicone rubber, which includes the following steps:

[0017] a. Dehydrate the vinyl silicone oil in a vacuum kneader at 90°C for 1.5 hours and cool it to room temperature;

[0018] b. Add the platinum catalyst to the vinyl silicone oil in proportion and stir for 30 minutes under nitrogen protection until evenly dispersed;

[0019] c. Fill the paste prepared in step b into tube A and tube B in a ratio of 8:2;

[0020] d. Seal tube A in bottle A, add pigments to tube B in proportion according to the total paste amount, mix evenly and then seal it in bottle B;

[0021] e. Store bottle A and bottle B synchronously and mix them when in use.

[0022] When the present invention is specifically implemented, the usage method of the catalyst is as follows:

[0023] 1. Use a spoon to take out the required amount of matrix (liquid silicone rubber), open the envelopes of catalyst bottles A and B, install the mixing head and the push rod, push out the catalyst, and the amount of catalyst taken out from bottle A and bottle B is the same;

[0024] Under the standard room temperature environment of 25°C ± 2°C, when the matrix addition amount is 30 g, adding different amounts of catalyst will result in different operations and curing times:

[0025] ① Catalyst addition amount: 2 cm, operation time 60', total curing time 12'.

[0026] ② Catalyst addition amount: 3 cm, operation time 50', total curing time 5'25".

[0027] ③ Catalyst addition amount: 4 cm, operation time 40', total curing time 3'30".

[0028] ④ Catalyst addition amount: 5 cm, operation time 40', total curing time 3'15".

[0029] ⑤ Catalyst addition amount: 6 cm, operation time 30', total curing time 2'50".

[0030] Note: The catalyst dosage can be adjusted according to the required time and room temperature. Increase the dosage when acceleration is needed, and decrease the dosage when deceleration is needed.

[0031] 2. Manually mix the matrix and the catalyst until the color is uniform;

[0032] Note: If the mixing is uneven, it will affect the curing and product performance.

[0033] 3. Stretch the mixed matrix into a long strip shape so that it can cover the working area after curing, and prepare it into the required shape for use.

[0034] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection of the present invention.

Claims

1. A catalyst for curing silicone rubber, characterized in that: It includes a platinum catalyst, vinyl silicone oil and a pigment. The mixing ratio of the platinum catalyst, vinyl silicone oil and pigment is: 3:5:

2. The viscosity of the vinyl silicone oil is 1000 - 5000 mPa·s, and the pigment is a high-temperature resistant organic pigment.

2. The preparation method of a catalyst for curing silicone rubber according to claim 1, wherein: It includes the following steps: a. Dehydrate the vinyl silicone oil in a vacuum kneader at 80 - 120 °C for 1 - 2 hours, and cool it to room temperature; b. Add the platinum catalyst to the vinyl silicone oil in proportion and stir for 30 minutes under nitrogen protection until evenly dispersed; c. Fill the paste prepared in step b into tubes A and B respectively according to a ratio of 8:2; d. Seal tube A in bottle A. Add the pigment to tube B in proportion according to the total paste amount, and after mixing evenly, seal it in bottle B; e. Store bottle A and bottle B synchronously, and mix them for use when in use.