new trends in silicone elastomer technology.
Silicone, or multi-organic polymer, due to its flexible inert skeleton consisting of alternating silicon and oxygen atoms, has various material features that are not available in any other single polymer family.
Table 1 lists the physical and chemical properties of various polymer systems.
The free rotation of silicon and oxygen atoms results in extremely high flexibility in harsh environmental conditions. The Si-O bond (at 369. 3KJ/mol)
Than typical c-C bond (347. 9 KJ/mol), and longer (1. 64 Angstroms. 1. 53 A)(ref. 2).
This combination of strength and softness makes silicone polymers a natural choice for sealing, damping, deflection, or wherever elastic materials are required.
As shown in Table 2, the performance of the resulting polymer is significantly affected by changing the substituent base on the silicon atom.
Depending on the desired performance, silicone materials can be designed by using a polymer containing any of the aforementioned substituents.
An example of this is fluorine-
Replacement Silicone Polymers exposed to solvents and corrosive oils must be borne in applications.
If resistance at extreme low temperatures is required, the silicone material will have some benzene-substituted silicone polymer to replace or in addition to Poly-dimethyl or poly-methyl vinyl silicone.
When the linear version of the above polymer is combined with the area-filled filler (
Silica is usually gas phase method)
A special type of silicone called elastic material is formed.
Compared to other silicone products such as pressure sensitive adhesive, resin or other systems, silicone elastomer is a flexible material with a large amount of internal physical strength.
Table 3 illustrates the variety in the product line.
Depending on the processing process, silicone elastomer can be divided into three different categories: can be poured, can be pumped and can be ground.
The final application will determine the type of elastic body required by considering the material requirements and processing parameters.
Only by coupling the correct processing with the correct material performance can a useful elastic system be obtained.
Silicone polymer with low molecular weight (10,000-100,000 g/mol)
A small amount of tonic [isless than]
15 parts and additional additives.
Since the molecular weight of the polymer is the molecular weight of the fluid and the load of the filler is moderate, it is necessary to add cross agents and other functional substances to improve the physical strength of these materials.
Depending on the formula and catalyst system used, these elastic balls are cured by condensation or addition reaction.
Pourable elestors are usually sold in a variety of proportions as two-part systems.
In any case, the mixture of the starting component makes the pre-
The viscosity of the curing material is 100-1,000,000 [mm. sup. 2]/s @ 25[degrees]
C. It\'s pourable (ref. 3).
Pourable siloxane elast is usually used as a mold in-place material or poured into the mold using low pressure.
Material needs to be removed once mixed and before molding
Ventilate to remove any stranded gas in the mix.
Unrelated to the mechanism, these materials are hot cured at medium temperatures.
Room temperature or room temperature
Vulcanization rubber, cured at room temperature.
The grindable elastic body consists of a very high molecular weight organic silicone and a large number of reinforced fillers (300,000-
800,000G/Moore and [Greater than]
Packing is 20 copies respectively).
The polymers used in this type of elastic material are essentially linear, and cross-connections are usually done by functional organic groups attached to silicon atoms on the polymer skeleton.
Depending on the formulation and final use of the product, the catalyst in these products is either peroxide or transition metal.
The compound is processed by grinding uncatalytic rubber using the selected catalyst, followed by subsequent compression molding or injection molding.
Due to the High Green intensity of chewing gum
Extrusion is also a possible manufacturing process.
An alternative to grinding and pouring systems is pumping silicone, commonly referred to as liquid silicone rubber.
Liquid injection molding silicone elastomer has been developed at GE Silicon 1975 to meet the demand for easy-to-process alternative cutting, high consistency rubber (ref. 4).
Liquid injection molding silicone rubber is made of a medium viscosity silicone polymer and is compounded with an enhanced filler, cross-linking agent, and a cured catalyst.
The curing system selected during liquid injection molding is based on platinum-catalytic Silicon hydrogen addition (ref. 5).
There are several inherent benefits to this type of catalysis, including very fast cycle times, thick and thin curing, and no reactionproducts.
High productivity is a sign of the liquid injection molding system, and short cycle time is critical to the production system.
The typical cycle time of the liquid injection molding elastic system is tens of seconds, while the cycle time of many other elastic systems is minutes.
The curing rate is determined by recording the torqueas time function on the modulated disk flowmeter.
Take a typical torque/time curve at 120 [degrees]C and 177 [degrees]
As shown in Figure 1. [
Figure 1 illustration omitted]
The T02 is 2% curing time, which represents the injection window of the material.
Similarly, the T90 is 90% of the total curing time of the material, which represents the complete curing of the material.
The maximum torque is a measure of the hardness of the material, and the peak rate indicates how fast the curing is completed once the processing begins.
The addition curing reaction is used in the liquid injection molding system because the elastic material is capable of curing both thick and thin sections at the same time.
And the condensation process must be removed-
In order to promote the completion of the reaction, there is no small molecule evolution in the addition curing reaction.
Therefore, as long as enough heat is transferred to most of the material, it will solidify as quickly as the surface.
This enables consistent curing in parts with uneven wall thickness.
The addition reaction is similar to the condensation of metal catalysis, because the catalyst species will remain in the material after curing occurs.
This is different from the free radical or peroxide catalytic system where the catalyst is destroyed during molding.
However, the remaining catalyst can be taken away during condensation [H. sub. 2]
O re-from the atmosphere
An aggregate network that balances curing.
This process is called a reply, which affects the functional life of the elastic material.
The platinum left in the additional treatment matrix will not be catalytic reversed, because the group without saturation can be associated with it and therefore will not produce an active sitikang (ref. 6).
Figure 2 shows platinum-
Ethylene bonds are formed by ethylene interaction and subsequent reactions. [
Figure 2 illustration omitted]
Generating active sites through platinum/unsaturated carbon interactions is critical to the mechanism of silicon hydrogen addition reaction (ref. 6).
Compared with grindable silicone rubber, liquid injection molding silicone rubber has some inherent advantages, which leads to an increase in productivity and a decrease in cost per part.
As shown in Table 4, the benefits of liquid injection molding Silicone elastic system. Table 4 -
Liquid injection molding.
Depending on the parts to be formed, the number of parts and the capital required, the liquid injection molding Silicone elastic system may be economically advantageous.
It is recommended to first use the liquid type system for a detailed cost analysis of the proposed process and then compare it with the grindable rubber system.
Table 5 the outlinesa method for determining the true cost of the part.
While it is not as detailed as the actual analysis, it does illustrate the need to consider all costs in the machining system, not just the cost of the material.
Silicone for liquid injection molding.
HCE cost analysis 1,000,000 part of the experimental liquid injection molding silicone rubber sample pre-formed at 177 [degrees]
C cool for 15 minutes and cool to room temperature before testing stretch, elongation, tearing, hardness and modulus.
Tensile strength of mold
B. tear strength, % elongation and 100% modulus were tested on Monsanto tensome10 at a speed of 50.
8 cm/minute until failure.
Durometer was measured on Exacta Hardness Testerby NewAge using a onshore stylus on a pressure-cured sheet.
The application rate is a measure of material fluidity determined by squeezing the material out of 3.
17mm holes in 0.
62 MPa and record the amount in grams/minutes.
Curing rate of materials measured at 177 [using Monsanto multi-drug resistant 2000 e]degrees]C.
The compression set is measured by compressing 1.
27mm material plugs, cured at 177 [30 minutes]degrees]
C, in the air circulation oven of 75% , of its original heightdegrees]C for 22hours.
Before the final sample is drawn, the sample is allowed to cool under ambient conditions.
The adhesion test was performed using a 1 pair of lap shear specimens of the required substrate. 27 cm x 1.
27 cm overlap with 3.
17mm thick liquid injection molded silicone as adhesive.
Sample cured in air circulation of 150 [30 minutes]degrees]
C, and allows cooling to room temperature before testing the fault on tensometer.
Results and discussion standard LIM material liquid injection molding silicone elastomer was developed as a processing substitute for grindable and poured silicone elastomer.
Since the liquid injection molding silicone elastomer is available in 1975, this material has become stronger, easier to produce, and has achieved unique performance according to the target application.
By looking at the material improvements made in the past 24 years, industrial acceptance of liquid injection molding silicone elastomer can be traced back.
Liquid injection molded was initially used for small parts under mild conditions.
Such examples include o-
Hanging ring, small cable ring, small gasket, etc.
Compared to the standard RTV, the silicone elastomer formed by the first liquid injection is opaque, adding a curing material with high tear strength (pourable)systems.
They have inherent solvent resistance and wear resistance and are cured in less than two minutes of 177 [by adding a curing process]degrees]C.
The performance properties of the initial liquid injection molding silicone material are sufficient to be accepted after introduction, and the material is still in use today.
However, there are some shortcomings in this material.
It is not clear at present that the proportion of the material is very high and the curing speed is two minutes faster.
This curing cycle is too long to take full advantage of the productivity provided by the liquid injection molding system.
The next improvement in liquid silicone rubber chemistry is the introduction of a clear, fast curing product line.
The material has the physical strength of the original liquid injection molded elastic return Ball series, but the optics are clear, the specific gravity is low, and in [is less than]
30 seconds at 177 [degrees]C.
The series has been found for use in applications from medical to electronic to consumer goods, and represents liquid injection molding silicone elastomer with the highest physical strength, fastest curing rate and minimum specific gravity.
Some applications that this line does not fill, including areas that require low compression sets, where self-
Bonding is required, or silicone is required to have a controlled force deflection when finally used.
The new development of force deflection, no primerless bonding and molded low compression permanent deformation controlled by LIM material properties is three key technical features that a new generation of liquid injection molded silicone elastomer must possess.
Progress has been made in all of the above areas, and the resulting new materials can be used in previous applications where the performance of liquid silicon fibers is insufficient.
The requirement for controlled force deflection to show controlled deflection of the elastic body has been determined.
This feature is useful in medical systems where elastic materials are used as springs in pumping systems or in the electronics industry where the keyboard requires controlled force to work effectively.
A series of liquid injection molding silicone elastomer with control deflection has been developed, providing a wide range of physical properties and processing alternatives.
The utilization rate of all these materials is very high, which means that they can be filled with complex geometry, such as the geometry used for pumps or keyboards, and cured in a very short period of time.
The selection of materials will depend on the physical strength required and the life of the parts.
Figure 3 shows the force deflection properties and life cycle of two of these materials. [
Figure 3 illustration omitted]
The controlled force deflection series materials provide different physical strength, application rate and life, thus providing the design engineer with great flexibility of the platform materials while maintaining a consistent deflection force. Self-
According to the general rules, part-by-design, liquid injection of moldesilie elostomers is not usually done without priming and/or post-baking.
LIM silicone elastomer is a curing material added, so there is no large number of polar species on the surface of the material interacting with other materials.
This type of non
The menu faces very good release performance, so the reason why silicone is often used as a release pad.
One reason why silicone is difficult to attach is that the surface energy of cured silicone is very low ~ 18 mN/m.
Low surface energy prevents other materials from moistening the surface of silicone.
The wet surface means that the material must be unfolded in such a way that the two surface areas are contacted under appropriate conditions.
Materials with lower surface energy wet materials with higher surface energy.
This is because the intra-molecular interaction of lower surface energy materials is low enough to be overcome by higher-energy substrate surfaces.
In order to determine the humidity of the material, contact angle measurement is usually used.
Place a drop of material on a surface of known energy and measure the angle with the drop tangent and surface.
As shown in figure 4, if the sample is not wet at all, the angle is is180 [degrees];
If the sample is completely wets, the angle is 0 [degrees].
Different degrees of non
Between these two extremes, moistening and moistening can occur.
Silicone usually has very high contact points, corresponding to very low surface energy, so it is difficult to wet.
Water droplets on organic silicon wax are a non-
Figure 4 illustration omitted]
Recently, there have been some developments that make it possible to easily combine the formulation of silicone with engineering plastics, glass and metal.
Adhesive or non-adhesive enables the design engineer to take full advantage of the productivity of the liquid injection molding elastic system by eliminating the start-up steps of the process.
Since it is no longer necessary to mechanically lock the elasticity in the appropriate position, the adhesive elasticity gives the part itself a certain design flexibility.
The first generation of self
At 177 [the adhesive liquid injection molded silicone elastomer is translucent and has good physical properties and molds in less than 30 secondsdegrees]C.
In addition to rapid curing and impressive physical profiles, the material has a low specific gravity and a high application rate.
The adhesive properties of this material have been tested on many engineering plastics and metals.
Table 6 gives the results of this test. Table 6 -
Adhesion test results on various substrates
The values given in the table represent the general material distribution, are qualitative and do not represent absolute.
This is because processing and contamination can affect the surface of the substrate.
Adhesion is purely a surface phenomenon, so contamination and impurities can damage adhesion.
Table 7 lists the quantitative experimental results of a single batch of 30% glass filled tb. (*)
30% the glass film is immediately important in the mold by using the adhesive obtained from this material, and increases with the duration of the part at room temperature and pressure.
In order to prevent the accumulation of silicone on the surface of the mold, the author suggests that the mold
Use a permanent nickel/PTFE coating before use.
This allows the parts to be easily removed from the mold and reduces the amount of work required for regular cleaning of the mold.
The low compression setIn is a typical additive-cured silicone elastomer with a functional mass of less than 100% for the reaction.
This is achieved to a certain extent by design, and is also the result of vinyl and hydrogen sulfide being locked in the polymer matrix, not in locations close to each other.
This is sufficient for the material to be designed at standard temperature and pressure.
However, if the material is exposed to extreme pressure and temperature for a long period of time, the unresponsive function groups present in the cured silicone network can react, making the parts have a new set of dimensions.
This phenomenon is called compression deformation, and the sensitivity of liquid injection molded silicone rubber limits their application in high temperature, high stress environments.
There are ways to reduce the compression permanent deformation performance of liquid silicone rubber, making it suitable for gasoline and seals for automotive applications under the hood, as well as environments requiring low compression permanent deformation.
The first of these methods is apost bake to drive the possible response to completion.
In this technique, the part is cooked in the oven for several hours at a temperature of 200 [nearby]degrees]
C. promote the response of any remaining functional groups. By post-
Bake a LIM that reduces the compressed set from a value of 45% [is less than]20%.
Another method is to fill the liquid silicone rubber with precipitated silica gel.
This leads to a system that usually has good compression set values in teenagers.
There are shortcomings in each method, which must be emphasized. Inpost-
When baking parts, the entire cycle time of subsystem manufacturing is lengthened by the number of later stagesbake.
This severely reduces the profitability of the liquid silicone system.
Compared to hot curing elastic materials, liquid silicone is profitable when you can quickly form the cycle.
If you were post-
Baking a part for four hours, the actual molding cycle is not a speed limit step, so reducing cycle time does not save a lot of the total production time.
In terms of the precipitation system, high filling leads to a low tearing system and a very high proportion.
A new method for achieving a low compression set in a liquid injection molding silicone rubber system has recently been developed, where astandard liquid injection molding silicone rubber system is combined with additive packaging to produce a low compression set.
The liquid injection molding silicone rubber studied has excellent physical properties, rapid curing cycle, low specific gravity and [molding compression device]is less than]20%.
This method of creating a low compression permanent deformation liquid injection molding Silicone elastic system has several advantages compared to the aforementioned precipitated silica gel method.
The specific gravity of low CS liquid injection molding silicone rubber is lower than that of precipitated silicone rubber.
This leads to a lower price per part because the part is filled by volume (L)
Sales of materials by weight (g).
Figure 5 compares the specific gravity of various liquid elastomer. [
Figure 5 illustration omitted]
As shown in Figure 6, the tear strength of the material is also affected under the precipitation system.
Even if the tear strength is not a key component of the part design, it is useful in partremoval, and the high tear strength can cause fewer parts to be scrapped due to tearing during processing. [
Figure 6 illustration omitted]
When the low compression set attribute is combined with the self-compression set attribute, the final material benefit can be obtained
Adhesive properties produce fluid injection molded rubber with both properties.
This material fits well belowthe-
LIM processing terms liquid injection molding silicone elastomer refers to the method of processing silicone by injection molding.
When the overall flow chart of this method of producing silicone (thermosets)
Compared with other injection molded elastic plastics and thermoplastic plastics, many similarities can be seen.
The LIM material is pumped to a static mixer in a 1:1 ratio and fed into the barrel of the injection molding machine.
Then, according to the style of the machine, the material is fed into the nozzle through the screw or ram type unit.
Since it is similar to thermoplastic molding, screws are the most common transfer methods, while ram/plunger methods are becoming more and more popular due to the high accuracy and repeatability of each material.
Until this point, the material is kept near room temperature to minimize the pre-
Treatment that occurs.
Such precautions must be taken because once the catalyst exists with the chain (i. e.
, After mixing A and Bare in A static mixer)
This material can be cured at high temperature.
This material is injected into the heated mold through a cooled nozzle.
Molding takes place at 10-
The mold will open in 40 seconds and the part will be removed.
The mold can be side or parting door, and the runner can be cold (cold)or heated (hot).
The cold runner system can save materials, but the cost of the mold will usually be higher, while the hot runner mold is a lower-cost capital investment, however, since the silicone elastomer formed by liquid injection is thermoformed and cannot be reused, the entire flow channel must be scrapped.
Comparison of molding conditions for silicone rubber and thermoplastic by liquid injection molding is shown in Table 8. Table 8 -
Liquid injection molding Silicon/ETP process comparison liquid injection molding silicon elastomer is usually used to make separate parts such as baby bottle nipples, floppy disk washers, intervals, o-rings, etc.
However, there are applications that require a more advanced form of molding in which the elastic material is formed on a thermoplastic or metal carrier.
This is called overforming and does not require the molding of discrete washers, assembled with the chosen carrier, resulting in productivity and lower overall cost.
In overforming, several factors must be taken into account, including the plastic used, the cycle time of the process, the injection pressure, the silicone material used and the molding design.
The molding conditions must be conducive to the construction of thermal plastics (ETP)
The substrate formed in Tg, Tmof materials must be compatible with the mold temperature, and the injection pressure must not deform the part during the molding cycle.
It is recommended to preheat the part before overforming, so that the substrate does not function as a radiator and slows the molding process down to a bad cycle time. Two-
By using two parts or two parts, maximum efficiency and design flexibility of shooting or two parts can be achieved
Injection molding, in injection molding, the ETPpart is formed, and the silicone elastomer formed by liquid injection is formed once on the plastic part.
In order to achieve the goal of forming thermostats and thermoplastic in one process, it is necessary to divide the whole process into three separate steps: * injection molding of ETP starts the whole process, the fastest step, usually [is less than]20 seconds.
* When the material is still hot, the mold opens and the part is transferred to the liquid injection molded silicone elastic tool in the second step.
* Then molded liquid injection molded silicone rubber on top of ETP to complete the cycle.
The mold is opened and a complete part is taken out, and the whole process begins.
The key to the whole process is to transfer the ETP part to the silicone molding part, which can be achieved in three ways: the rotary plate, the retractable core and the rotary plate.
The rotating platform, perhaps the most versatile two-component molding method, uses the rotating plate to transfer the ETP to the liquid injection molding part.
In the rotary plate design, the thermoplastic plastic is injected into the thermoplastic mold and cooled to a certain extent in the mold.
Once the structural integrity of the part is fully realized, the mold opens and the part is removed from both sides of the mold.
The part is maintained by a center plate and the center plate rotates so that the plastic part is now located between the two heated parts of the liquid injection molded silicone elastic mold.
The mold is closed, and the silicone is formed on the plastic parts, while forming new plastic parts in the previous cavity.
Once the elastic material molding cycle is completed, the mold is opened again, separated from both sides of the part, the part is removed, the center platform is closed, the mold is closed, and the whole molding process is repeated.
Figure 7 shows the chemical properties of this design. [
In addition to the full thermoplastic side of the mold, the rubber can be fixed on both sides of the part by having a complete and dedicated liquid injection molding side.
This ability provides a lot of design flexibility, but it also poses some technical challenges.
During the molding process, the part must be disassembled and reshaped on both sides, which means that the tolerance of the thermoplastic mold must be very tight in order for the part to be consistent with the tolerance in the liquid injection molding silicone mold.
The sliding core mold forms another way of liquid silicone rubber on the thermoplastic plastic by sliding core mold.
Instead of removing the part and moving it to a new location, the mold is able to form additional air holes for liquid silica gel through an internal sliding mechanism.
The ETP is molded in the first part of the process, and then when it cools, the mold changes the shape to create gaps for silicone filling.
The silicone cavity can be formed by sliding pins or cores, and once this occurs, the silicone elastomer formed by liquid injection is formed in place.
Although this eliminates the need to rotate the mold, the mold design becomes very complex depending on the desired cavity type and quantity.
Another drawback is that the two processes of thermoplastic molding and liquid silicone molding must be carried out in series.
This leads to two independent molding activities that must be carried out equally during the molding cycle, thus reducing the productivity of the whole process.
The third mold design option available for rotating templates in the dual-element mold system is rotating templates.
In this design, three of the four mold cavities are thermoplastic forming designs because they are cooled to the temperature required for the ETP part of the molded part.
Once the thermoplastic molding cycle is completed, the mold will open, the part will remain in half of the mold, and then the entire half of the mold rotates so that the plastic part is aligned with the heating half of the liquid injection molding silicone elastomer.
The mold of the liquid silicone mold is closed, and another hot plastic part is molded at the same time.
The Liquidsilicone mold uses the original thermoplastic material as a closing device, and the entire thermoplastic cycle is completed when the LIM Silicone elastic material is formed.
The increase in cycle time is at the expense of mold complexity.
To take advantage of this two-component molding method, it is necessary to have the ability of sequential injection and gate.
This, and the necessity of the rotation of the entire mold, leads to a more complex mold design.
Rotating formwork molds do not allow the molding of liquid silicone rubber on both sides of the thermoplastic part, but only liquid silicone rubber on one side facing the heating silicone mold.
Independent of which type of mold system to use, other factors need to be taken into account when designing a dual lens system.
The type of gate, whether it is a cold runner or a hot runner, must be determined according to the complexity of the mold and possible material loss.
This process should have the flexibility to be sequential.
The position and size of the vent must be determined.
Even the geometry of the ETP part is related to the liquid injection molding puzzle as it can be used as a closure
Its potential heat can be used to assist in the injection molding of silicone rubber by hot curing liquid.
The appropriate material must be selected according to the part design.
As arule, the physical properties remain the same throughout the liquid injection molded silicone product line.
The typical value is: Tensilestrength 6. 2-8. 96 MPa; elongation 300-700%;
B tear strength62-5. 25 J/[cm. sup. 2];
And proportion 1,100-1,150 Kg/[m. sup. 3].
Materials should be selected based on other factors required, such as clarity, adhesion and fluidity.
Table 9 is useful in determining the correct material that meets the specific design requirements.
It is important to decide which type of bonding is required between the liquid injection molded silicone rubber and the ETP substrate.
There are three types of bonding available: * in static bonding, the material is connected to the substrate by a strong enough force to keep the rubber on the sub-strategy in order to remove it from the mold, but weak enough so that the rubber can be removed without damaging the bulk material.
* The second bonding option is mechanical interlocking.
In this method, the design of the ETP part makes it have a cut or flow channel that allows the flow of uncured liquid silicone rubber, but prevents the curing material from being removed.
This is a form of physical bonding, which is useful where the part will fall off to remove the elastic material of static bonding.
The lower-cut scanning presents a technical challenge to the design of the traditional ETP part, in addition, at the micro level, the bond is easy to leak around the rubber part.
* Final bonding occurs by using chemical bonds.
This is possible by using the self
Adhesive liquid injection molding silicone rubber.
Bonds obtained by this method in [Greater than]
90% cohesive failure inside the rubber.
The following data focuses on
When forming on various plastic substrates using two injection molding processes, adhesive liquid injection molding silicone rubber.
Select sample geometry to illustrate three different features that are common in injection parts: o-ring gasket;
Vertical interlocking seal;
And variable nominal wall band.
These parts are formed on a 150-ton double-split ETP injection molding machine that is converted into a nETP/liquid silicone double shot machine.
The part cycle time varies from a few minutes to less than 40 seconds throughout the molding process, depending on the elastic return tube. Adhesion data (table 10)
, Given in a qualitative way, corresponding to the number of cohesive failures (excellent is [isgreater than]
95% cohesive failure). Table 10 -two-
Test with self-mold bonding
Bonding-grade ssissianes provides unique properties as elastic materials, and is therefore increasingly used in this application.
The liquid injection molded silicone material has excellent physical and chemical properties, making it a suitable replacement for standard grindable and poured silicone elastomer.
New progress in liquid injection molding silicone materials, including self-injection
The combination, low compression set, and controlled force deflection solve some of the previous problems that limit the use of these systems in certain applications.
Component forming is especially suitable for liquid silicon system. the progress of mold design makes two
The injection ETP/liquid injection molding elastic system to be developed soon.
This system provides extremely high productivity, and when combined with material progress, depicts a bright future for liquid injection molding silicone. References(1. )F. S. Kipping, Proc. Chem. Soc. 20, 15 (1904). (2. )J. March.
\"Advanced Organic Chemistry\"Interscience (1985). (3. )B. B. Hardman and A. Torkelson.
Encyclopedia of Chemical Technology. pp. 922-962 (1982). (4. )U. S.
Patent 3884866 Jeram et al. (5. )J. L.
Webster J. SpierA. and Barnes G. H. , J. Am. Chem. Soc. 79, 974 (1957). (6. )B. Marciniec.
Pergamon publishing house \"comprehensive manual of silicon hydrogen addition reaction\" (1992).