CN113621138B

CN113621138B - Claw-type polyvinyl silicone oil and preparation method thereof

Info

Publication number: CN113621138B
Application number: CN202110915256.5A
Authority: CN
Inventors: 李书兵; 徐小刚; 孙刚; 王龙文; 李磊; 段贤桂
Original assignee: Yichang Collin Silicon Material Co ltd; Hubei Xingrui Silicon Material Co Ltd
Current assignee: Yichang Collin Silicon Material Co ltd; Hubei Xingrui Silicon Material Co Ltd
Priority date: 2021-08-10
Filing date: 2021-08-10
Publication date: 2022-10-21
Anticipated expiration: 2041-08-10
Also published as: CN113621138A

Abstract

The invention relates to claw-type polyvinyl silicone oil and a preparation method thereof, wherein the preparation method comprises the following steps: dimethyl siloxane ring bodies, methyl vinyl siloxane ring bodies and hexavinyl disiloxane), adding the pretreated materials into a stirring kettle in proportion, keeping the constant temperature T = 30-70 ℃, pumping the materials into a fluidized bed through a conveying pump, reacting at a low temperature to obtain a crude polymer, and feeding the crude polymer into a low-temperature removal system with the pressure of less than 50Pa and the temperature of 100-150 ℃ to obtain the claw-type polyvinyl silicone oil with no peculiar smell, good appearance transparency and low silicon hydroxyl value. The claw-type polyvinyl silicone oil prepared by the low-temperature solid catalyst improves the use efficiency of the hexavinyl disiloxane, reduces the cost, does not additionally introduce metal ions, enriches the varieties of the vinyl silicone oil, and can greatly enhance the application performance indexes such as the linear expansion coefficient, the size change rate and the like of materials such as silica gel and the like.

Description

Claw-type polyvinyl silicone oil and preparation method thereof

Technical Field

The invention relates to claw-type polyvinyl silicone oil and a preparation method thereof.

Background

The vinyl silicone oil is the main raw material of addition type silicone rubber, a reinforcing agent of high-temperature rubber, a modifier of other materials such as polyurethane, acrylic ester and the like, and has wide application fields. The polyvinyl silicone oil is polysiloxane which generally takes siloxane chain links as a main chain, a side chain or an end position and contains vinyl groups and has higher vinyl content, and mainly has the performances of increasing crosslinking density, improving hardness, tearing strength and the like.

Chinese patent document CN105482121A (application No. CN 201511008606.0) discloses a synthetic method of polyvinyl silicone oil, which comprises the following steps: dimethyl cyclosiloxane mixture DMC and tetramethyl divinyl disiloxane are subjected to polymerization reaction under the action of an alkaline catalyst, after the reaction is finished, the temperature is increased to degrade the alkaline catalyst, low-boiling-point substances are removed by distillation, and finally the polyvinyl silicone oil is obtained. The process has the alkaline catalyst of tetramethyl ammonium hydroxide, the reaction temperature is 90-110 ℃, but the boiling point of tetramethyl divinyl disiloxane is 139 ℃, the process is volatile to generate higher saturated vapor, and the effective utilization rate is low. The obtained polyvinyl silicone oil has a polysiloxane main chain and 1 equivalent of vinyl group at the terminal position, and the finished product has a large ammonia odor.

Chinese patent document CN105384936B discloses a preparation method of polyvinyl silicone oil, which comprises the following steps: adding a linear body, tetramethyl tetravinylcyclotetrasiloxane and a capping agent into a reaction kettle, heating to 130-150 ℃, adding potassium hydroxide, stirring for reaction, keeping the temperature, vacuumizing, performing dehydration reaction, recovering normal pressure, adding phosphoric acid or silicon-based phosphate for neutralization, and heating and removing low molecules under negative pressure to obtain the product. Wherein the end sealing agent is methyl silicone oil with the polymerization degree of 2-5 or single vinyl-terminated silicone oil. The main chain of the product obtained by the method is polysiloxane, the terminal position is methyl or single vinyl group, the residual amount of potassium ions is high, and the potassium ions are difficult to remove, so that the application of the product in a scene with requirements on insulating property is limited.

The claw-type polyvinyl silicone oil containing 3 equivalent of vinyl groups at the end positions can improve the crosslinking density of materials such as silicon rubber and the like, greatly improve the application performances such as linear expansion coefficient, size change rate and the like of addition type silicon rubber and modified materials, and is particularly applied to aerospace and aviation neck materials. The polyvinyl silicone oil which takes polysiloxane as a main chain and contains 3 equivalent of vinyl groups at the end position and the preparation method thereof are reported, so that the development of the synthetic method of the claw-type polyvinyl silicone oil has important significance.

Disclosure of Invention

In order to prepare the claw-type polyvinyl silicone oil, the ammonia odor is eliminated, the potassium ion content in the product is greatly reduced, the application performance of the product is improved, and the application scene is not influenced. In order to achieve the purpose, the invention provides the following technical scheme:

the molecular formula of the claw-type polyvinyl silicone oil is shown as follows,

wherein m = 1-250, n = 0-50, wherein m and n are integers.

A preparation method of claw-type polyvinyl silicone oil comprises the following steps:

(1) Pretreating raw materials, namely removing water and impurities from dimethyl siloxane ring (DMC) and hexavinyl disiloxane (HVDS);

(2) Adding the pretreated DMC and HVDS into a stirring kettle in proportion, and heating to T = 30-70 ℃ to obtain a mixed material A;

(3) Pumping the mixed material A into a fluidized bed with a constant temperature of T +/-2 ℃ by a material delivery pump, filling a resin catalyst B into the fluidized bed, and allowing the material to pass through the fluidized bed for 5min to 24h to obtain a crude polymer C;

(4) And (3) removing the crude polymer C to obtain a finished product D under the conditions that the pressure is less than 50Pa and the temperature is 100-150 ℃.

The pre-treatment of DMC, VMC and HVDS includes at least filtering in the first stage bag filter and the first stage membrane filter, where the filtered DMC is dewatered in a dewatering kettle at pressure lower than 200Pa and temperature 40-80 deg.c for 0.5-6.0 hr, the DMC, VMC and HVDS are adsorbed in a molecular sieve packed tower separately, and the treated DMC has purity higher than 99.999% and water content lower than 20ppm; HVDS purity is greater than or equal to 99.9%, and water content is less than 20ppm.

In the addition amount of dimethyl siloxane ring body and hexavinyl disiloxane in the step (2), DMC accounts for 64.0-98.5 wt%, and HVDS accounts for 1.5-36.0%.

And (2) adding methylvinylsiloxane ring bodies (VMC), wherein the VMC is pretreated by filtering through at least a first-stage bag filter and a first-stage membrane filter, the VMC is respectively adsorbed by a molecular sieve packed tower, and the purity of the VMC is more than or equal to 99.99% and the water content of the VMC is less than 20ppm after treatment.

The proportions of DMC, VMC and HVDS are that DMC accounts for 64.0-97.5 wt%, VMC accounts for 1-10.0% and HVDS accounts for 1.5-36.0%.

The resin catalyst in the step (3) is polystyrene cation exchange resin loaded with acid sites, wherein the concentration of the acid sites is more than or equal to 5.0mmol/g, the effective particle size is 0.50-2.00 mm, the uniformity coefficient is less than or equal to 1.50, and the water content is less than or equal to 0.5%.

Through the technical scheme, the invention has the following technical effects:

1. the raw materials are pretreated by removing water and impurities, so that the purity of the raw materials is improved, side reactions are reduced, and a target product is purified.

2. The boiling point of the hexavinyl disiloxane is 119 ℃, the volatile component is volatile, the reaction temperature T plus or minus 2 (T = 30-70 ℃) of the invention greatly reduces the saturated vapor pressure of the hexavinyl disiloxane during the reaction, and improves the use efficiency of the hexavinyl disiloxane.

3. The invention adopts porous particles such as polystyrene with higher loading acid site concentration, not only does not have the decomposition of temporary catalyst of tetramethylammonium hydroxide and residual ammonia odor, but also can avoid the ion residue introduced outside the catalyst such as potassium hydroxide and the like which need to be neutralized.

4. The fluidized bed is a double-layer inner and outer cylinder structure, the inner cylinder can rotate, the inner cylinder wall is treated by three prevention and the like, the adhesion of raw and auxiliary materials on the inner wall is greatly reduced, the raw and auxiliary materials are in dynamic balance, and the reaction stability and the material utilization efficiency are improved.

The claw-type polyvinyl silicone oil prepared by the method has no peculiar smell, good appearance transparency, turbidity less than 0.5NTU and relative value of silicon hydroxyl less than 1.050. The reaction temperature is lower, the energy consumption and the carbon emission are reduced, the saturated vapor pressure of the materials is reduced, and the utilization efficiency of the materials is improved.

Detailed Description

Example 1

100kg dimethyl siloxane ring body (DMC) is filtered by a first-stage bag filter and a first-stage membrane filter, enters a glass fiber reinforced plastic dehydration kettle, is heated to 70 ℃, is vacuumized under 100Pa, and is dehydrated for 4 hours to obtain DMC-1 with the purity of 99.9995 percent and the water content of 15ppm for later use.

10kg of hexavinyl disiloxane (HVDS) is filtered by a first-stage bag filter and a first-stage membrane filter respectively, and then enters a packed tower filled with molecular sieves respectively for 18h to obtain HVDS-1 with the purity of 99.92% and the water content of 12ppm for later use.

Catalyst: the acid site-loaded polystyrene cation exchange resin has the acid site concentration of 5.1mmol/g, effective grain size of 0.50-1.00 mm, uniformity coefficient of less than or equal to 0.50 and water content of less than or equal to 0.15%.

1950g of DMC-1 and 50g of HVDS-1 were added to a stirred tank made of glass fiber reinforced plastic, and the mixture was stirred at low speed for 1 hour while the temperature was raised to 70. + -. 2 ℃ to obtain a mixture A1. The mixture raw material A1 is pumped into a fluidized bed with an inner cylinder capable of rotating at 68 +/-2 ℃ through a delivery pump, the residence time of the catalyst in the fluidized bed is controlled to be about 1h, and a crude polymer C1 with the viscosity of 145cP and the conversion rate of 88.8 percent is obtained. And (3) feeding the crude polymer C1 into a reduction system with the pressure of 35-45 Pa and the temperature of 130 ℃ to obtain a finished product D1. The finished product D1 has the molecular formula of m = 100-150 and n =0, is colorless and transparent in appearance, has 0.75% of volatile components, has the viscosity of 236cP, and has the relative value of silicon hydroxyl of 1.023.

Example 2

The procedure and the procedure were the same as in example 1 except that the residence time in the fluidized bed was controlled to about 4 hours, to obtain a crude polymer C2 and a finished product D2, respectively. Crude polymer C2, viscosity 185cP, conversion 89.1%. And the finished product D2 has the molecular formula of m = 140-190 and n =0, is colorless and transparent in appearance, has 0.80% of volatile matter, has the viscosity of 304cP and has the silicon hydroxyl relative value of 1.028.

Example 3

The procedure and procedure were the same as in example 1 except that the constant temperature in the stirred tank was 40. + -. 2 ℃ and the constant temperature in the fluidized bed was 35. + -. 2 ℃ to obtain crude polymer C3 and finished product D3, respectively. Crude polymer C3, viscosity 125cP, conversion 84.1%. And a finished product D3, wherein m = 800-135 and n =0 in the molecular formula, is colorless and transparent in appearance, has 0.78% of volatile matter, 190cP in viscosity and 1.020 in relative value of silicon hydroxyl.

Example 4

The procedure and procedure were the same as in example 1 except that the pressure was reduced at 25 to 30Pa and the temperature was 110. + -. 2 ℃ to obtain a crude polymer C4 and a finished product D4, respectively. Crude polymer C4, viscosity 147cP, conversion 88.6%. The finished product D4 has the molecular formula of m = 100-150 and n =0, is colorless and transparent in appearance, has 1.50% of volatile components, has the viscosity of 212cP and has the relative value of silicon hydroxyl of 1.022.

Example 5

100kg dimethyl siloxane ring body (DMC) is filtered by a first-stage bag filter and a first-stage membrane filter, enters a glass fiber reinforced plastic dehydration kettle, is heated to 70 ℃, is vacuumized under 100Pa, and is dehydrated for 4 hours to obtain DMC-5 with the purity of 99.9995 percent and the water content of 15ppm for later use. 10kg of methyl vinyl siloxane ring body (VMC) and 10kg of hexavinyl disiloxane (HVDS) are respectively filtered by a first-stage bag filter and a first-stage membrane filter, and then respectively enter a packed tower filled with molecular sieves to be treated for 18h, so that VMC-5 with the purity of 99.992 percent, the water content of 10ppm, HVDS-5 with the purity of 99.92 percent and the water content of 12ppm are respectively obtained for standby. 1850g of DMC-5, 80g of VMC-5 and 70g of HVDS-5 were added into a stirred tank made of glass fiber reinforced plastics, and the mixture was stirred at low speed for 1 hour while the temperature was raised to 70. + -. 2 ℃ to obtain a mixture A5. The mixture raw material A5 is pumped into a fluidized bed with an inner cylinder capable of rotating at 68 +/-2 ℃ by a delivery pump, the acid site concentration of a catalyst in the fluidized bed is 5.6mmol/g (the effective particle size is 0.80-1.20 mm, the uniformity coefficient is less than or equal to 0.60, and the water content is less than or equal to 0.20%), the retention time is controlled for about 1 hour, and a crude polymer C5 with the viscosity of 80cP and the conversion rate of 87.5 is obtained. And (3) feeding the crude polymer C5 into a reduction system with the pressure of 35-45 Pa and the temperature of 130 ℃ to obtain a finished product D5. And a finished product D5, wherein m = 70-130 and n = 3-8 in the molecular formula, is colorless and transparent in appearance, has 1.25% of volatile components, has the viscosity of 128cP and has the silicon hydroxyl relative value of 1.027.

Example 6

The procedure and the procedure were the same as in example 5 except that the residence time in the fluidized bed was controlled to about 6 hours, to obtain a crude polymer C6 and a finished product D6, respectively. Crude polymer C6, viscosity 105cP, conversion 88.2%. The finished product D6 has the molecular formula of m = 80-140 and n = 3-8, is colorless and transparent in appearance, has 1.28% of volatile components, has the viscosity of 156cP and has the silicon hydroxyl relative value of 1.030.

Example 7

The procedure and procedure were the same as in example 5 except that the temperature in the stirred tank was kept constant at 55. + -. 2 ℃ and the temperature in the fluidized bed was kept constant at 50. + -. 2 ℃ to obtain crude polymer C7 and finished product D7, respectively. Crude polymer C7, viscosity 73cP, conversion 84.7%. And a finished product D7, wherein m = 70-130 and n = 3-8 in the molecular formula, is colorless and transparent in appearance, has 0.75% of volatile matter, has viscosity of 126cP and has a silicon hydroxyl relative value of 1.026.

Example 8

The procedure and procedure were the same as in example 5 except that the pressure was reduced to 25 to 30Pa, to obtain a crude polymer C8 and a finished product D8, respectively. Crude polymer C8, viscosity 79cP, conversion 87.6%. And a finished product D8, wherein m = 70-130 and n = 3-8 in the molecular formula, is colorless and transparent in appearance, has 0.52% of volatile matter, 130cP in viscosity and 1.021 in silicon hydroxyl relative value.

Comparative example 1

The acid site concentration of the catalyst in the fluidized bed was 3.2mmol/g (effective particle size 0.50-1.00 mm, uniformity coefficient not more than 0.50, water content not more than 0.15%), and the other procedures and steps were the same as in example 1 to obtain crude polymer C1-1 and finished product D1-1, respectively. Crude polymer C1-1, viscosity 81cP, conversion 62.5%. The finished product D1-1 has a molecular formula of m = 90-160 and n =0, is colorless and transparent in appearance, has a volatile component of 0.85%, has a viscosity of 228cP, and has a silicon hydroxyl relative value of 1.021.

Comparative example 2

The procedure and procedure were the same as in example 1 except that the temperature in the stirred tank was kept constant at 110. + -. 2 ℃ and the temperature in the fluidized bed was kept constant at 105. + -. 2 ℃ to obtain crude polymer C1-2 and finished product D1-2, respectively. Crude polymer C1-2, viscosity 320cP, conversion 89.4%. The finished product D1-2 has a molecular formula of m = 230-300 and n =0, is colorless and transparent in appearance, has 0.75% of volatile matter, has the viscosity of 589cP and has the relative value of silicon hydroxyl of 1.019.

Comparative example 3

The concentration of the acid sites of the catalyst in the fluidized bed is 4.5mmol/g, the effective particle size is 0.50-1.00 mm, the uniformity coefficient is less than or equal to 1.0, the water content is less than or equal to 0.2 percent, and other processes and steps are the same as those of the example 1, so that a crude polymer C1-3 and a finished product D1-3 are respectively obtained. Crude polymer C1-3, viscosity 146cP, conversion 88.7%. The finished product D1-3 has a molecular formula of m = 100-150 and n =0, is colorless and transparent in appearance, has 0.75% of volatile matter, has the viscosity of 238cP and has the relative value of 1.020 of silicon hydroxyl.

Comparative example 4

The procedure and procedure were the same as in example 1 except that the pressure was reduced to 180 to 200Pa, to obtain crude polymers C1-4 and finished products D1-4, respectively. Crude polymer C1-3, viscosity 142cP, conversion 88.3%. And a finished product D1-4, wherein m = 100-150 and n =0 in the molecular formula, is colorless and transparent in appearance, has 2.83% of volatile components, has the viscosity of 218cP and has the relative value of silicon hydroxyl of 1.025.

Comparative example 5

The procedure and the procedure were the same as in example 1 except that 1300g of DMC-1 and 700g of HVDS-1 were used, to obtain crude polymers C1-5 and finished products D1-5, respectively. Crude polymer C1-5, viscosity 3.1cP, conversion 78.3%. The finished product D1-5 has a molecular formula of m = 7-12 and n =0, is colorless and transparent in appearance, has 4.60% of volatile components, has the viscosity of 5.4cP, and has the relative value of silicon hydroxyl of 1.019.

Comparative example 6

The procedure and procedure were the same as in example 5 except that the temperature was 190 ℃ to obtain crude polymer C5-6 and finished product D5-6, respectively. Crude polymer C5-6, viscosity 80cP, conversion 87.7%. The finished product D5-6 has a molecular formula of m = 70-130 and n = 3-8, is light yellow and transparent in appearance, has 0.43% of volatile matter, has the viscosity of 135cP and has the silicon hydroxyl relative value of 1.023.

Comparative example 7

The procedure and procedure were the same as in example 5 except that DMC, VMC and HVDS were not subjected to impurity removal, to obtain crude polymer C5-7 and finished product D5-7, respectively. Crude polymer C5-7, viscosity 53cP, conversion 85.7%. And a finished product D5-7, wherein m = 50-110 and n = 3-8 in the molecular formula, the appearance is turbid, the volatile matter is 1.05%, the viscosity is 109cP, and the relative value of silicon hydroxyl is 1.078.

Comparative example 8

Adding 1850g of dimethyl siloxane ring body, 80g of VMC and 70g of HVDS into a stainless steel reaction kettle (DMC, VMC and HVDS are not subjected to impurity removal treatment), stirring, heating to 130 ℃, adding 0.052g of potassium hydroxide, keeping the temperature, stirring for reaction for 3 hours, adding 0.062g of phosphoric acid for neutralization for 0.5 hour, and obtaining a crude polymer C5-8 with the viscosity of 79cP and the conversion rate of 85.6 percent after the neutralization is finished. And (3) removing the crude polymer C5-8 in a removing system with the constant temperature of 180 +/-2 ℃ and the pressure of 3kPa to obtain the polyvinyl silicone oil D5-8. The polyvinyl silicone oil D5-8 has a molecular formula of m = 70-130 and n = 3-10, is yellow and slightly turbid in appearance, contains 2.60% of volatile components, has a silicon hydroxyl relative value of 1.17 and has a viscosity of 131cP.

Comparative example 9

Adding 1850g of dimethyl siloxane ring body, 80g of VMC and 70g of HVDS into a stainless steel reaction kettle (DMC, VMC and HVDS are not subjected to impurity removal treatment), stirring, heating to 100 ℃, adding 0.110g of tetramethylammonium hydroxide, keeping the temperature, stirring for reaction for 3 hours, heating to 150 ℃, degrading an alkaline catalyst tetramethylammonium hydroxide for 6 hours, and decomposing the catalyst for 3 hours at 140 +/-2 ℃, thereby obtaining a crude polymer C5-9 with the viscosity of 74cP and the conversion rate of 83.6%. And (3) entering a low removal system with the constant temperature of 140 +/-2 ℃ and the pressure of 500Pa for removing low to obtain the polyvinyl silicone oil D5-9. The polyvinyl silicone oil D5-9 has a molecular formula of m = 70-130 and n = 3-10, has a large ammonia odor, is colorless and transparent in appearance, contains 2.50% of volatile components, has a silicon hydroxyl relative value of 1.21, and has a viscosity of 119cP.

Comparative example 10

DMC, VMC and HVDS pretreatment, addition proportions were the same as in example 5, except that: adding the materials into a stainless steel reaction kettle, stirring, heating to 100 ℃, adding 0.110g of tetramethylammonium hydroxide, keeping the temperature, stirring for reacting for 3h, heating to 150 ℃, degrading an alkaline catalyst tetramethylammonium hydroxide for 6h, and decomposing the catalyst at 170 +/-2 ℃ to obtain a crude polymer C5-10, the viscosity of 89cP and the conversion rate of 86.9%. And (3) removing the crude polymer C5-10 in a removing system with the constant temperature of 170 +/-2 ℃ and the pressure of 200Pa to obtain the polyvinyl silicone oil D5-10. The polyvinyl silicone oil D5-10 has a molecular formula of m = 70-130 and n = 3-10, has a large ammonia odor, is light yellow and transparent in appearance, has a volatile component of 0.76%, a silicon hydroxyl relative value of 1.018, and has a viscosity of 126cP.

Claims

1. A preparation method of claw type polyvinyl silicone oil comprises the following steps:

(1) Pretreating raw materials, namely performing water removal and impurity removal pretreatment on dimethyl siloxane ring bodies and hexavinyl disiloxane;

(2) Adding the pretreated dimethyl siloxane ring body and hexavinyl disiloxane into a stirring kettle in proportion, and heating to the temperature of T = 30-70 ℃ to obtain a mixed material A;

(3) Pumping the mixed material A into a fluidized bed with a constant temperature of T +/-2 ℃ by a material delivery pump, filling a resin catalyst B in the fluidized bed, wherein the resin catalyst B is polystyrene cation exchange resin loaded with acid sites, the concentration of the acid sites is more than or equal to 5.0mmol/g, the effective particle size is 0.50-2.00 mm, the uniformity coefficient is less than or equal to 1.50, the water content is less than or equal to 0.5%, and the retention time of the material in the fluidized bed is 5 min-24 h to obtain a crude polymer C;

(4) And (3) removing the crude polymer C to obtain the finished claw-shaped polyvinyl silicone oil under the conditions that the pressure is less than 50Pa and the temperature is 100-150 ℃, wherein the claw-shaped polyvinyl silicone oil has a simple structure formula as follows:

wherein m = 1-250, n = 0-50, wherein m and n are integers.

2. The method for preparing claw-type polyvinyl silicone oil according to claim 1, wherein the dimethyl siloxane ring body in step (1) has a purity of not less than 99.999% and a water content of less than 20ppm; the purity of the hexavinyl disiloxane is more than or equal to 99.9 percent, and the water content is less than 20ppm.

3. The method for preparing a claw-type polyvinyl silicone oil according to claim 1, wherein in the addition amount of dimethylsiloxane rings and hexavinyldisiloxane in step (2), DMC accounts for 64.0-98.5 wt%, and HVDS accounts for 1.5-36.0%.

4. The method for preparing claw-type polyvinyl silicone oil according to claim 1, wherein methyl vinyl siloxane ring bodies are further added in the step (2), the purity of the methyl vinyl siloxane ring bodies is more than or equal to 99.99%, and the water content is less than 20ppm.

5. The method for preparing claw-type polyvinyl silicone oil according to claim 4, wherein the proportions of the dimethylsiloxane rings, the methylvinylsiloxane rings and the hexavinyldisiloxane in step (2) are 64.0 to 97.5wt% for the dimethylsiloxane rings, 1 to 10.0% for the methylvinylsiloxane rings and 1.5 to 36.0% for the hexavinyldisiloxane.