CN104140529A - Preparation method of high-viscosity silicone oil - Google Patents

Abstract

The invention discloses a preparation method of high-viscosity hydroxyl-terminated room-temperature vulcanized silicone rubber. The preparation method is characterized by comprising the following steps: A, respectively throwing a dimethyl siloxane mixture, a sealing agent and a potassium hydroxide catalyst into a reaction kettle, stirring, heating to 70-90 DEG C, and then performing vacuum dehydration; B, when the temperature of the reaction kettle reaches 100-140 DEG C, stopping vacuum dehydration, and performing telomeric reaction; C, sampling and detecting, requiring that the ring opening rate reaches more than 85%, and starting a vacuum pump to perform low-component removal operation after polymerization reaction ends; D, after the low-component removal operation is completed, stopping heating, cooling, and packaging to obtain a finished product; or, transferring a material in the reaction kettle to a finished product storage tank for later packaging. By adopting the method, the preparation method disclosed by the invention can be used for preparing high-viscosity silicone oil; the preparation method is simple in process and stable in viscosity, and can not cause a long-sticking phenomenon; the product yield can be increased by 3-5% compared with the existing technical conditions; moreover, the preparation method is easy to control the reaction temperature required for different viscosity, is simple to operate, can be used for saving 8-12% of the cost compared with the same industry, and can meet the requirements of production and markets.

Description

A kind of preparation method of viscous silicone fluid

Technical field

The present invention relates to the preparation method of silicone oil, especially relate to a kind of preparation method of viscous silicone fluid.

Background technology

The purposes of silicone oil glue is extremely extensive, particularly viscous silicone fluid.General viscous silicone fluid is called again 201 methyl-silicone oils, and its range of viscosities is: 2000-100000 mm ²/ s(coventional type), 100000 mm ²/ s above (client need and produce), flash-point:>=300 ℃, it is the linear siloxanes polymkeric substance of exhaustive methylation high molecular, is highly viscous semisolid.The multifrequency natures such as viscous silicone fluid has high, antiseized smooth, the waterproof hydrophobic of molecular weight, reduces surface tension, resistance to oxidation stability and good weatherability, high thermal resistance, resistance to compression, oilness are good, good insulating, colorless and odorless, nontoxic and physiology inertia, are widely used in the rumbling compound of automobile, furniture, floor and leather etc.; In the industry such as chemistry, pharmacy, food, can be made into high effective antifoaming agent; In daily chemical industry, be widely used in makeup; For powder coating, can improve flame retardant properties and the feel of coating; In precision optical machinery and instrument, can be used as shockproof, damping material.

Produce silicone oil material used all the time, if with cracking material: dimethyl silica alkylating mixture (DMC) is manufactured, there is individual shortcoming in capital: be exactly that meeting is returned sticky along with the prolongation of time and the rising of temperature there will be, long sticky phenomenon, namely viscosity can raise at leisure, particularly southern summer temp is higher, more easily occur that viscosity do not advise the change of side, cause the viscosity needing by client while producing to produce, if but manufacturer is not used in the words of production in the short period of time, increase along with period of storage, viscosity will raise at leisure, exceed the needed standard of producing, thereby affect the quality of production, cause serious financial loss to supplier and client.This is mainly used for the starting material of producing, if the silicone oil that the dimethyl silica alkylating mixture that industrial electronic glue scrap stock are produced is processed into, quality is uneven to differ greatly, and causes viscosity to be difficult for accurately controlling.This DMC is during for the production of low sticky silicone oil, even if return sticky, long sticky quality is also affected not quite, but just affects very large for the production of the sticky silicone oil of height.

summary of the invention:

The object of the present invention is to provide a kind of preparation method of high viscosity terminal hydroxy group room temperature vulcanized silicone rubber.

The object of the present invention is achieved like this:

A preparation method for high viscosity terminal hydroxy group room temperature vulcanized silicone rubber, feature is:

A, by dimethyl silica alkylating mixture (DMC), closure agent (dimethyl silicone oil that viscosity is 5cs) and catalyzer: potassium hydroxide drops into respectively in reactor, start the agitator in reactor, in order to reduce loss of material and to guarantee vacuum hydro-extraction effect, slowly heat up to reactor, be heated to 70--90 degree, then carry out vacuum hydro-extraction;

B, question response still temperature reach 100--140 degree while spending, and stop vacuum hydro-extraction, by the nitrogen pressure release of intrasystem vacuum pressure, then carry out telomerization, telomerization: 120 ℃ telomerize, polymerization 4-11 hour, during maintain polymerization temperature at 120 ± 5 ℃;

C, maintain this temperature of reaction, in the middle of getting for the first time, sample detects intermediate viscosity and open loop rate, detects intermediate viscosity and the open loop rate of middle sample for the first time, continues to heat up when open loop rate >=85%, temperature is controlled to 180-220 ℃, after polyreaction finishes, start vacuum pump and take off low operation, de-low molecule, vacuum tightness≤-0.095Mpa, take off to without linear drop, get middle sample for the second time and detect final viscosity, perform an analysis to closing the requirement of symbol customer order;

D, after de-low molecule manipulation completes, stop, to reactor heating, the temperature of reactor being down to packaging temp, after packing, get product; Or by the substance transfer in reactor to finished product storage tank, to be packaged.

The present invention uses rearrangement technology, with dimethyl silica alkylating mixture (DMC), manufacture high sticky silicone oil, production and technology can be guaranteed, and preparation technology is simple, stable viscosity, there will not be long sticky phenomenon, the comparable existing technical qualification of product yield improve 3--5%, and the required temperature of reaction of different viscosity is easy to control, simple to operate, than the cost 8--12% that saves of the same trade, can meet the demand of production & marketing.

embodiment:

Below in conjunction with embodiment, the present invention is further detailed.

Raw material is processed:

Cracking DMC raw material is added in washing kettle, then adds a certain amount of deionized water to wash it and start stirring, heats up to washing kettle simultaneously, and its temperature is controlled 60-75 ℃ and carried out boiling.Holding temperature boiling temperature 2-4 hours, stops stirring, lowering the temperature.Stratification 6-8 hours, gets rid of the water at the bottom of still.By washing, Cucumber in DMC is eliminated together with water simultaneously.

Embodiment 1:

By the dimethyl silica alkylating mixture (DMC) of 1000 kilograms, closure agent (dimethyl silicone oil that viscosity is 5cs) and the catalyzer of 2 kilograms: 100 grams of potassium hydroxide drop into respectively in reactor, start reactor agitator, slowly heat up to reactor, be heated to 70 degree, then carry out vacuum hydro-extraction.Question response still temperature reaches 100 while spending, and stops vacuum hydro-extraction, carries out telomerization.Maintain this temperature of reaction, in the middle of getting for the first time, sample detects intermediate viscosity and open loop rate, require open loop rate to reach more than 85% requirement, after polyreaction finishes, start vacuum pump and take off low operation, de-low molecule, vacuum tightness≤-0.095Mpa, take off to without linear drop, get middle sample for the second time and detect final viscosity, perform an analysis to closing the requirement of symbol customer order; After de-low molecule manipulation completes, stop, to reactor heating, reactor being down to packaging temp, after packing, get product.

Embodiment 2:

By the dimethyl silica alkylating mixture (DMC) of 2000 kilograms, closure agent (dimethyl silicone oil that viscosity is 5cs) and the catalyzer of 4 kilograms: 200 grams of potassium hydroxide drop into respectively in reactor, start reactor agitator, slowly heat up to reactor, be heated to 90 degree, then carry out vacuum hydro-extraction.Question response still temperature reaches 140 while spending, and stops vacuum hydro-extraction, carries out telomerization.Maintain this temperature of reaction, in the middle of getting for the first time, sample detects intermediate viscosity and open loop rate, require open loop rate to reach more than 85% requirement, temperature is controlled to 220 ℃, after polyreaction finishes, start vacuum pump and take off low operation, de-low molecule, vacuum tightness≤-0.095Mpa, takes off to without linear drop, in the middle of getting for the second time, sample detects final viscosity, performs an analysis to closing the requirement of symbol customer order; After de-low molecule manipulation completes, stop to reactor heating, the substance transfer in reactor is to finished product storage tank, to be packaged.

Embodiment 3:

By the dimethyl silica alkylating mixture (DMC) of 1500 kilograms, closure agent (dimethyl silicone oil that viscosity is 5cs) and the catalyzer of 3 kilograms: 150 grams of potassium hydroxide drop into respectively in reactor, start reactor agitator, slowly heat up to reactor, be heated to 80 degree, then carry out vacuum hydro-extraction.Question response still temperature reaches 110 while spending, and stops vacuum hydro-extraction, carries out telomerization.Maintain this temperature of reaction, in the middle of getting for the first time, sample detects intermediate viscosity and open loop rate, require open loop rate to reach more than 85% requirement, temperature is controlled to 200 ℃, after polyreaction finishes, start vacuum pump and take off low operation, de-low molecule, vacuum tightness≤-0.095Mpa, takes off to without linear drop, in the middle of getting for the second time, sample detects final viscosity, performs an analysis to closing the requirement of symbol customer order; After de-low molecule manipulation completes, stop heating to reactor.Reactor is down to packaging temp, after packing, gets product.

Claims (1)

1. a preparation method for high viscosity terminal hydroxy group room temperature vulcanized silicone rubber, is characterized in that:

A, by dimethyl silica alkylating mixture (DMC), closure agent (dimethyl silicone oil that viscosity is 5cs) and catalyzer: potassium hydroxide drops into respectively in reactor, start the agitator in reactor, slowly heat up to reactor, be heated to 70--90 degree, then carry out vacuum hydro-extraction;

B, question response still temperature reach 100--140 while spending, and stop vacuum hydro-extraction, then carry out telomerization, telomerization: 120 ℃ telomerize, polymerization 4-11 hour, during maintain polymerization temperature at 120 ± 5 ℃;

C, maintain this temperature of reaction, in the middle of getting for the first time, sample detects intermediate viscosity and open loop rate, detects intermediate viscosity and the open loop rate of middle sample for the first time, continues to heat up when open loop rate >=85%, temperature is controlled to 180-220 ℃, after polyreaction finishes, start vacuum pump and take off low operation, de-low molecule, vacuum tightness≤-0.095Mpa, take off to without linear drop, get middle sample for the second time and detect final viscosity, perform an analysis to closing the requirement of symbol customer order;

D, after de-low molecule manipulation completes, stop, to reactor heating, the temperature of reactor being down to packaging temp, after packing, get product; Or by the substance transfer in reactor to finished product storage tank, to be packaged.