CN102516773B - Silicon rubber compound special for nipple and preparation method thereof - Google Patents

Abstract

The invention relates to a silicon rubber compound special for a pacifier and a preparation method thereof. Raw rubber is added into a kneader by weight, and the rest components are added by weight for three to five times. In each time of material feeding, after fed material is stirred to be absorbed by the raw rubber to be molded, the next feeding is conducted. Temperature is lower than 85 DEG C, after all components are fed, stirring is continued for 0.8 to 1.2 hours, and the temperature is lower than 100 DEG C. The inside of the kneader is in a vacuum negative pressure state, and the temperature of the kneader rises to 170 DEG C, negative pressure constant temperature is kept for 2-3 hours, materials are discharged after a vacuum state is kept for 10 minutes and cooled, rolls are covered, sheets are discharged, and the materials are filtered to obtain products. The silicon rubber compound special for the pacifier not only has good transparency and physical performance, has good mold releasing performance, and simultaneously is high in production efficiency, small in defective percentage, long in storage life and fully in accordance with requirements for manufacturing the pacifier for a baby.

Description

A kind of silicon rubber compound special for pacifier and preparation method thereof

Technical field

The invention belongs to baby nipple manufacturing technology field, exactly is a kind of silicon rubber compound special for pacifier and preparation method thereof.

Background technology

At present, gas phase method silicone rubber compound is when being made into nipple, and the transparency of nipple is not high, or unstable, the well satisfying the market requirement more and more higher to the baby nipple transparency.Secondly in the process of producing nipple, it is inadequate the nipple physicals often to occur, easily is torn when making the finished product delivery, and the defect ware rate is high.

The baby nipple master glue prescription that uses now is general to adopt high, medium and low vinyl rubber to cooperate, usually cross-linked rubber hardness is about 48 degree, the also requirement that has is about 40 degree, and average vinyl content wherein is higher, vulcanization rate is fast, and cross-linking density is large, and contractibility is little, the transparency that improves cross-linked rubber is had certain help, but so that product when the demoulding, easily tear.

Summary of the invention

The object of the invention is exactly in order to remedy the defective of prior art, a kind of not only have good transparency and physicals to be provided, and to add the silicon rubber compound special for pacifier that has good demolding performace man-hour.

The present invention is achieved by the following technical solutions:

A kind of silicon rubber compound special for pacifier is characterized in that: it is to be made by the raw material of following weight part: rubber 10000, gas-phase silica 2800-4200, hydroxy silicon oil 300-500, containing hydrogen silicone oil 50-90, Zinic stearas 10-45, ultramarine 4-6.

Described a kind of silicon rubber compound special for pacifier, it is characterized in that: described rubber average vinyl content is 0.14-0.24%, it is comprised of the component of following weight part: contents of ethylene is raw-silastic continuously or the silicone oil 20-80 of 3.0-10.0%, contents of ethylene is the raw-silastic continuously 1200-3000 of 0.14-0.18%, ethylene content is the raw-silastic continuously 6000-8500 of 0.03-0.09%, the viscosity of described hydroxy silicon oil is that 20-30CS, hydroxy radical content are 7.5-8.5%, and the hydrogen number that contains of described containing hydrogen silicone oil is 1.2-2.0%.

A kind of preparation method of silicon rubber compound special for pacifier is characterized in that may further comprise the steps:

A, in kneader, add by weight rubber, divide by weight again to add all the other components three to five times, feed intake each time be stirred to rubber and eat the powder moulding after, feed intake, temperature is less than 85 ℃ next time again, added whole components after, continue to stir 0.8-1.2 hour, temperature is less than 100 ℃;

B, the interior negative pressure of vacuum of kneader also are warmed up to 170 ℃, keep negative pressure constant temperature after 2-3 hour, and vacuum discharging about 10 minutes namely gets product after cooling, bag roller, slice, the filtration.

The selection of each material kind and consumption:

1. the raw-silastic continuously contents of ethylene is selected to need to use high, medium and low three kinds of methyl vinyl silicon kautschuks to cooperate, average vinyl content is 0.14-0.24%, take rubber as 100 parts of calculating as mass parts, wherein, rubber or the silicon oil dosage of high-vinyl-content (3.0-10.0%) are about the 2-8% mass parts, the rubber consumption of medium vinyl content (about 0.16) accounts for the 12-30% mass parts, and the rubber consumption of low ethylene content (0.03-0.09) accounts for the 60-85% mass parts.Can form good tensile strength, tear strength and elongation like this;

2. the selection of the molecular weight of raw-silastic continuously need to use molecular weight to be the rubber of 55-75 ten thousand, can guarantee that rubber has larger mooney viscosity, and the shearing force when improving refining glue makes the easier dispersion of reinforced filling, to improving the transparency side of product;

3, to select specific surface area be that the above gas-phase silica of 250m2/g carries out reinforcement in the selection of reinforced filling, and long-pending larger than table, reinforcing effect and transparency are just better.General consumption is the 28-42% mass parts, and the gas-phase silica consumption is larger, and tear strength is higher, and hardness is higher, but the rubber unvulcanizate flowability is poorer, will have a negative impact to processing characteristics.QS25, QS30, the QS40 of the model of commonly using at present such as day Bender mountain production, the T40 of watt gram, the H300 of Cabot, 380, H5 etc.;

3. the hydroxy silicon oil of low viscosity (20-30CS), hydroxy radical content higher (about 8%) is selected in the selection of constitution controller.Consumption is about the 3-5% mass parts.With the low hydroxyl oil of viscosity the rubber unvulcanizate heat refining heat up and thermostatic process in, by vacuum, low molecule volatilizees easily, can not remain in the middle of the silica gel, and the silica gel transparency is improved, and can not turn white, a mist.Hydroxy radical content is high, the dispersiveness in the time of can improving silica gel adding white carbon black and the storage time of rubber unvulcanizate;

4. the selection of anti-yellowing and vulcanization accelerator: select to contain hydrogen number and be about 1.6% high containing hydrogen silicone oil.Consumption is about the 0.5-0.9 mass parts.So that be difficult in process of production xanthochromia at silicon rubber gross rubber, and the post vulcanization during nipple is non-yellowing; Vulcanization rate in the time of can improving the sulfuration of nipple glue, the production efficiency of raising product;

5, the consumption of the selection releasing agent of releasing agent has strict restriction, and the transparency of meeting reduction silicon rubber that consumption is many causes nipple to turn white, send out mist.Consumption is about the 0.1-0.45 mass parts.At present the most frequently used is the Zinic stearas of import.The nipple of making like this is difficult for sticking to mould, takes out easily in mould, so that product is not easy to damage when the demoulding, production efficiency is high, and mould is in cleaning.

Beneficial effect of the present invention is:

1, the present invention has high-clarity, when using the present invention to be made into nipple, has kept good transparency, non-whitening;

2, the nipple good physical performance made of the present invention, shrinking percentage is little, and elasticity is good, and product can not form parcel and the adsorption to mould, and product is difficult for being torn when taking out from mould;

3. the releasing agent kind and the consumption that use of the present invention do not affect the transparency that silica gel is made nipple, can make that the nipple of primary vulcanization is removed easily in mould;

4, production efficiency of the present invention is high, and fraction defective is little, has higher tensile strength, tear strength, elongation, suitable hardness and good release property and long shelf lives, meets fully for the requirement of making baby nipple.

Embodiment

(1) main raw material(s)

High-vinyl silicone oil is self-produced; Two kinds of poly-ethylene methacrylic radical siloxanes (raw-silastic continuously), molecular weight 65-75 ten thousand, contents of ethylene are respectively 0.16% and 0.04%, and the silicon industry company of containing is closed in Zhejiang;

White carbon black QS25, day Bender mountain; Hydroxy silicon oil, the Hongyuan, Yangzhou; Containing hydrogen silicone oil Zhejiang San Men; Zinic stearas, Singapore; Ultramarine, Shanghai.

(2) proportioning of the special-purpose rubber unvulcanizate of gas phase transparent silicon rubber nipple

(2) the main manufacturing and processing equipment of the special-purpose rubber unvulcanizate of gas phase transparent silicon rubber nipple

Equipment	Model	The place of production
			Two roller mills	16 cun	Morning twilight rubber machinery plant, Wuxi
Kneader	20L	Jiangsu prosperous and powerful kneader factory
			Vulcanizing press	25 tons	Taizhou

(3) plant and instrument

Detecting instrument equipment mainly contains sclerometer, reisilometer, electronic tensile machine etc.

Equipment	Model	The place of production
			Sclerometer	LX-A	Jiangdu Xin Zhenwei test machines limited liability company
The impact elasticity test instrument	WTD-0.5	Jiangdu Xin Zhenwei test machines limited liability company
			Electronic tensile machine	?	Jiangdu Xin Zhenwei test machines limited liability company

(4) sample preparation

1, a kind of preparation method of silicon rubber compound special for pacifier is characterized in that may further comprise the steps:

A, in kneader, add by weight rubber, divide by weight again to add all the other components three to five times, feed intake each time be stirred to rubber and eat the powder moulding after, feed intake, temperature is less than 85 ℃ next time again, added whole components after, continue to stir 1 hour, temperature is less than 100 ℃;

B, the interior negative pressure of vacuum of kneader also are warmed up to 170 ℃, keep negative pressure constant temperature after 2-3 hour, and vacuum discharging about 10 minutes namely gets product after cooling, bag roller, slice, the filtration.

2, performance test

170 ℃ * 10min of sample cure conditions

Transparency detects

1. do two sulfuration test pieces (about 50 grams, thickness are 2 millimeters), observe its vulcanization rate, yellowing resistance, release property is not to adsorb mould as standard; 2. get wherein one under natural light, be placed on the centre of the palm and observe, test piece is limpid, penetrating, non-whitening, without vaporific be standard; 3. get wherein one and do the physicals detection, hardness is pressed GB/T 531-1999 test; Pull apart tensile strength and elongation, tear strength is tested by GB/T 528-1998.

(5) conclusion

This product Shao Er hardness is 47 degree, has both taken into account the high strength with 9.8Mpa, the high resistance tearing force of 38KN/M, takes into account again to have 62% good resilience and 4% less tensile set.

This product not only has good transparency and physicals, and has good demolding performace man-hour adding, and production efficiency is high simultaneously, and fraction defective is little, has the long shelf lives, meets fully for the requirement of making baby nipple.

Claims (2)

1. silicon rubber compound special for pacifier, it is characterized in that: it is to be made by the raw material of following weight part: rubber 10000, gas-phase silica 2800-4200, hydroxy silicon oil 300-500, containing hydrogen silicone oil 50-90, Zinic stearas 10-45, ultramarine 4-6; Described rubber average vinyl content is 0.14-0.24%, it is comprised of the component of following weight part: contents of ethylene is raw-silastic continuously or the silicone oil 20-80 of 3.0-10.0%, contents of ethylene is the raw-silastic continuously 1200-3000 of 0.14-0.18%, ethylene content is the raw-silastic continuously 6000-8500 of 0.03-0.09%, the viscosity of described hydroxy silicon oil is that 20-30CS, hydroxy radical content are 7.5-8.5%, and the hydrogen number that contains of described containing hydrogen silicone oil is 1.2-2.0%.

2. the preparation method of silicon rubber compound special for pacifier according to claim 1 is characterized in that may further comprise the steps:

A, in kneader, add by weight rubber, divide by weight again to add all the other components three to five times, feed intake each time be stirred to rubber and eat the powder moulding after, feed intake, temperature is less than 85 ℃ next time again, added whole components after, continue to stir 0.8-1.2 hour, temperature is less than 100 ℃;

B, the interior negative pressure of vacuum of kneader also are warmed up to 170 ℃, keep negative pressure constant temperature after 2-3 hour, and vacuum discharging in 10 minutes namely gets product after cooling, bag roller, slice, the filtration.