JPH0413766A - Composite-type silicone gel material and production thereof - Google Patents

Abstract

PURPOSE:To obtain a composite-type silicone gel material having almost linear stress-strain relationship and causing little deterioration of various properties according to the increase of load by compounding a silicone gel and a filler and forming an uncured thin layer at the interface between the silicone gel and the filler. CONSTITUTION:A substance selected from sulfur, phosphorus, tin compound and amine compound having deactivation effect to a platinum-based catalyst is adsorbed to the surface of a filler in gaseous and/or liquid phase of said substance. The treated filler is added to an uncured silicone gel and the gel is cured by the addition reaction in the presence of a platinum-based catalyst.

Description

[Detailed description of the invention]

(Purpose of the invention)

[Industrial application field]

The present invention is directed to a composite silicone gel material and a composite silicone gel material that can more advantageously exhibit the physical properties of a composite silicone gel material with fillers added, which has come to be used as a cushioning material, a vibration isolator, and a packaging material. The manufacturing method is explained below.

[Background of the invention]

Recently, the excellent cushioning and vibration-proofing properties of gel-like substances have attracted attention.
It has come to be used as insulators for various rotating equipment and OA equipment, insulators for precision, optical, and measuring equipment, special packaging materials, and cushioning materials for various sporting goods. In addition, the ability to tolerate large strains under light loads is an advantage in applying it to various sensors. Among gel materials, addition reaction type silicone gels are used, but in composite silicone gel materials made by adding various fillers to this gel material, depending on the type of filler added,
It has increased buffering properties, improved vibration isolation properties, and additional functions such as conductivity, magnetism, and piezoelectricity. However, when a filler is added, the hardness of the resulting composite silicone gel material generally increases, but the amount of strain is also greatly affected by the applied load. There was a problem in that the various characteristics also tended to be highly dependent on the applied load. For example, adding a specific filler to improve vibration isolation will certainly improve the vibration isolation performance, but on the other hand, the vibration isolation performance will also change sensitively depending on the applied load. In some cases, the expected performance was not achieved. Furthermore, in other applications, silicone gel loses its characteristic of being a material with a low elastic modulus, resulting in the problem that it does not meet the intended purpose.

[Technical matters attempted to be developed]

Therefore, the present invention has been made in view of the current situation, and even in the case of a composite silicone gel material to which a filler is added for a specific purpose, the relationship between the amount of strain and the applied load cannot be determined. Another approach is to create a nearly linear relationship so that the amount of strain does not depend greatly on the applied load, thereby solving the conventional drawback that the various properties exhibited by adding fillers are largely dependent on the applied load. Conventionally, when fillers were added, commercially available fillers were either left untreated or treated with a commercially available coupling agent. This is an attempt to improve the physical properties of a composite silicone gel material by forming an uncured thin layer at the interface. (Structure of the invention)

[Means to achieve the purpose]

Therefore, the composite silicone gel material of the present invention is a composite silicone gel material comprising a silicone gel obtained by curing a silicone gel stock solution and fillers scattered in this silicone gel, and the silicone gel is continuously cured. Forming the entire phase-C and forming a thin layer of uncured silicone gel stock solution at the filler interface,
It is characterized in that a filler is supported through the layer. In addition, the method for producing a composite silicone gel of the present invention includes adding a substance selected from i yellow, phosphorus, a tin-based compound, or an amine compound having an effect of deactivating a platinum-based catalyst, which is a hydrosilylation catalyst, to at least the surface of the filler. In advance, a step of adsorbing the substance in the gas phase and/or liquid phase, a step of adding the filler to which the substance has been adsorbed to an uncured silicone gel, and a step of adding the filler to the uncured silicone gel to which the filler has been added are performed. The method is characterized by comprising a step of subjecting the silicone gel to an addition reaction using the platinum-based catalyst to cure it.

[Action of the invention]

The silicone gel that is the base material in the present invention is made by crosslinking diorganopolysiloxane consisting of dimethylsiloxane component units and organohydrodiene polysiloxane through a hydrosilylation reaction using a platinum catalyst.
It is an addition reaction type silicone gel that hardens. Certain compounds such as sulfur, phosphorus, tin-based compounds, and amines are avoided during the normal curing process because they are so-called catalyst poisons that deactivate the catalytic action of platinum-based catalysts and inhibit crosslinking reactions. However, in the present invention, by actively utilizing the action of these substances as catalyst poisons, even if the entire uncured silicone gel undergoes an addition reaction and is being cured, these substances are not present on the filler surface. deactivates the catalytic action, stops crosslinking and curing of the uncured silicone gel at the filler interface, and forms an uncured layer around the filler. As a result, in the composite silicone gel material obtained, due to the presence of the uncured layer, the added filler is not restricted by the hardened continuous phase of the silicone gel and has freedom of movement, while the silicone gel itself has the ability to move freely. does not directly form a continuous phase. Due to this, for example, as the applied load increases,
Due to the mechanical bond between the gel and the filler, the applied load-strain curve draws a sharp curve, and the damping characteristics, which tend to deteriorate synergistically as the applied load increases, are not exhibited by the addition of the filler. Various characteristics associated with this are eliminated. Here, the silicone gel which is a component as a base material is
It consists of dimethylsiloxane component units and has the following formula [
Diorganopolysiloxane (component A) used in 1]: RR'2S i O-(R22S i O), lS
i R'2R...[■Co[However, R is an alkenyl group, R1 is a monovalent hydrocarbon group having no aliphatic unsaturated bond, and R2 is a monovalent aliphatic hydrocarbon group ( At least 50 mol% of R2 is a methyl group, and if it has an alkenyl group, its content is 10 mol% or less), and n is the viscosity of this component at 25°C of 10
0~100. The number is OOOcst]
and an organohydrodiene polysiloxane (component B) having a viscosity of 5000 cst or less at 25°C and having at least three hydrogen atoms directly bonded to 81 atoms in one molecule, and The ratio (molar ratio) of the total amount of alkenyl groups contained in the diorganopolysiloxane (component A) to the total amount of hydrogen atoms directly bonded to Si atoms in (component B) is 0. It is an addition reaction type silicone copolymer obtained by curing a mixture adjusted to have a molecular weight of 1 to 2.0. To explain this silicone gel in more detail,
The diorganopolysiloxane, which is the above component A, has a linear molecular structure, and has alkenyl groups R at both ends of the molecule.
is a compound that can form a crosslinked structure by adding with the hydrogen atom directly bonded to the Si atom in component B. The alkenyl group present at the end of the molecule is preferably a lower alkenyl group, and in consideration of reactivity, a vinyl group is particularly preferred. Furthermore, R1 present at the end of the molecule is a monovalent hydrocarbon group having no aliphatic unsaturated bonds, and specific examples of such groups include methyl, propyl, and hexyl groups. Examples include alkyl groups, phenyl groups and fluoroalkyl groups. In the above formula [I], R2 is a -valent aliphatic hydrocarbon group, and specific examples of such groups include alkyl groups such as methyl, propyl, and hexyl groups, and vinyl groups. Examples include lower alkenyl groups such as However, if at least 50 mol% of R2 is a methyl group and R2 is an alkenyl group,
Preferably, the alkenyl group is present in an amount of 10 mol% or less. If the amount of alkenyl groups exceeds 10 mol %, the crosslinking density becomes too high and the viscosity tends to increase. In addition, n is the viscosity of this component A at 25°C, which is usually 100 to 100.
．． 000 cSt, preferably 200-20,00
It is set within the range of 0 cSt. The organohydrodiene polysiloxane, which is component B, is a crosslinking agent for component A, and the hydrogen atom directly bonded to the S1 atom adds to the alkenyl group in component A to harden component A. It is sufficient that the component B has the above-mentioned effect, and as the daily component, those having various molecular structures such as linear, branched chain, cyclic, or network-like can be used. Also,
In addition to the hydrogen atom, an organic group is bonded to the Si atom in the solar component, and this organic group is usually a lower alkyl group such as a methyl group. Furthermore, the viscosity of component B at 25°C is usually 5000 cst or less, preferably 5
00 cSt or less. Examples of such components include organohydrodienesiloxane with both molecular ends capped with triorganosiloxane groups, copolymers of diorganosiloxane and organohydrogensiloxane, tetraorganotetrahydrodienecyclotetrasiloxane, HR '2Si
Mention copolymerized siloxanes consisting of O1,2 units and S i O4/2 units, and copolymerized siloxanes consisting of HR'2 S 101/2 units, R13S i O172 units, and S i O(/22 units). However, in the above formula, R1 has the same meaning as above.Then, the total molar amount of alkenyl groups in component A with respect to the total molar amount of hydrogen atoms directly bonded to Si in component B, and It is produced by mixing and curing component A and component B so that the ratio is usually in the range Ii of 001 to 2.0, preferably 0.1 to 1.0.The curing reaction in this case is usually carried out using a platinum-based catalyst. Examples of such platinum-based catalysts include finely ground elemental platinum, chloroplatinic acid, platinum oxide, complex salts of platinum and olefins,
Mention may be made of platinum alcoholades and complex salts of chloroplatinic acid with nylsiloxane. Such a catalyst is A
Usually 0.1pp+ based on the total weight of component and B component
*(Platinum equivalent amount, IF for below!) or more, preferably 0
．． 5pl) used in amounts of 11 or more. There is no particular restriction on the upper limit of the amount of such catalyst, but for example, if the catalyst is in liquid form or can be used as a solution, an amount of 200 ppH+ or less is sufficient. The silicone gel obtained by mixing and curing such component A, component B, and catalyst is rated according to JISK (K-2
The penetration measured at 207-198050g load is usually 5 to 250 degrees. The hardness of such a silicone gel can be adjusted by using the amount of the above-mentioned A component in excess of the amount that can form a crosslinked structure with the hydrogen atoms directly bonded to and produced from Si in the component. Be able to do it. In addition, as another method, silicone oil having methyl groups at both ends is applied to the resulting silicone gel for 5 to 7 hours.
It can also be adjusted by adding it in advance in an amount within the range of 5% by weight. In addition to the above-mentioned components A, B, catalyst, and filler, pigments, curing retarders, flame retardants, etc. may also be blended within a range that does not impair the properties of the resulting silicone gel. Such silicone gels can be prepared as described above, or commercially available ones can also be used. Examples of commercially available products that can be used in the present invention include CF3027, TOUGH-3, TO
UGH-4, TOUGH-5, TOUGH-6, TOU
GH-7 () - Made by Dow Corning Silicone Co., Ltd.)
, X32-902/cat1300 (Shin-Etsu Chemical Co., Ltd.), F25O-121 (Nihon Uniriki ■i2), and the like. Next, the substance that deactivates the catalyst used in the present invention will be explained. This substance may be organic or inorganic, as long as it reacts with the platinum-based catalyst more quickly than the reactive groups of the silicone gel and forms a strong chemical bond between the two. Specifically, sulfur-based compounds include sulfuric acid, ammonium sulfate, ammonium persulfate, sodium persulfate, sodium sulfite, hydrosulfide, and 1llI! as inorganic compounds. + Sulfates such as hydroxyamines, sulfur, carbon disulfide, sodium sulfoxylate (Rongalit), etc., and organic compounds include thioglycolic acid, butyl thioglycolate, thioglycolic acid and thioglycolic acid, etc. Examples include thioglycolic acid and its derivatives such as butyl acid, mercaptan compounds such as β-mercaptopropionic acid, surfactants such as thioacetic acid, thiourea, sulfonate salts, and sulfuric acid ester salts. In addition, examples of phosphorus compounds include inorganic compounds such as phosphoric acid, ammonium phosphate phosphorous acid, hypophosphorous acid, sodium pyrophosphate, acidic sodium metaphosphate, and sodium tripolyphosphate, and phosphoric acids and their salts.
Examples of organic phosphorus compounds include trimethyl phosphate, dialkyldithiophosphoric acid, and phosphorous ester. Furthermore, tin compounds include various tin chlorides and tin oxides, as well as rhodan salts and stannous sulfate, and amine compounds include iminobispropylamine, triethylamine, 3-diethylaminopropylamine, Examples include tetramethylethylenediamine and 3-methoxypropylamine. Furthermore, fillers added to the silicone gel as a base material include organic and inorganic balloons, general fillers such as talc, mica, and lead powder, metal-based, organic-based,
Inorganic fibers, whiskers, conductive and piezoelectric fillers, etc.
Any additive may be used as long as it is added to improve or add functionality. Therefore, a filler added for any purpose is mixed and dispersed in an uncured silicone gel, and then an addition reaction is caused by the platinum-based catalytic action and the filler is cured to obtain a composite silicone gel material. In the method of the present invention, before adding the filler to the uncured silicone gel, the filler is brought into contact with a substance that is a catalyst poison of the platinum-based catalyst in its gas phase and/or liquid phase, and at least A treatment is performed to adsorb these substances onto the surface. This can be done by leaving the filler to be added in an atmosphere containing organic or inorganic compounds such as sulfur, phosphorus, tin-based compounds or amines, or by placing the filler in an aqueous or solvent solution in which the compound is dissolved. This is done by immersing the material and then removing water and solvent by heating or the like. Thereafter, a predetermined amount of the filler that has undergone this treatment is added to one or both of the uncured silicone gel A solution and B solution, and a curing step is carried out. In the curing process, these uncured raw materials are placed in designated molds, trays,
Alternatively, the film is poured onto a molding surface such as a heald surface on which a film is laid, and then heated at a predetermined temperature and for a predetermined time, for example, 80° C. for 1 hour, while applying pressure if necessary, to harden to a desired hardness. A composite silicone gel material of the present invention having a desired shape is obtained. In the present invention, the catalyst poison of the platinum-based catalyst adsorbed on the filler selectively reacts with the platinum-based catalyst in the silicone gel raw material at the interface of the filler during the curing process, and the two are strongly bonded to each other. Even if the activity of the system catalyst is deactivated and uncrosslinked components still exist in the silicone gel phase, the reaction at the filler interface is stopped, and the silicone gel that is the base material hardens, forming a hardened continuous phase of the gel. Even if a silicone gel is formed, the uncured silicone gel is not cured on the surface of the filler dispersed therein, and an uncured layer is formed at the filler interface. As a result, in the composite silicone gel material obtained, due to the presence of the uncured phase, the filler is not restrained by the hardened continuous phase of the silicone gel and has freedom of movement, while the silicone gel itself is not directly connected to the filler. The load-strain curve can now exhibit linearity without forming a continuous phase, and for example, the damping characteristics, which tend to deteriorate as the applied load increases, can be significantly improved. Note that the detarder compound, which is a component of silicone gel, also reacts with the hydrosilylation catalyst using a reaction mechanism similar to that of these catalyst poison compounds, but the purpose is to prevent crosslinking reactions below the curing temperature. The catalyst is selectively reacted with the catalyst, and during the crosslinking reaction, it is dissociated or decomposed at a temperature higher than the curing temperature to restore the catalytic activity. On the other hand, the compounds used in the present invention react with the catalyst more quickly than the reactive groups of the gel, but the bond with the catalyst is permanent, and the purpose of use, method of use, ingredients, and contents of the compound are permanent. Completely different.

【Example】

Commercially available Phyllite (registered trademark = made by Nippon Phyllite ■), grade 200/7, which is pre-dried micro hollow spheres of silica alumina, was mixed with commercially available Soft Seishin (registered trademark 2), which is a linear alkylhenzenesulfonic acid surfactant. After pouring into a 100T PPM aqueous solution of NOF ■1 and stirring, it was filtered with a Nutsche filter and dried at 120°C for a day and night to make the filler adsorb the catalyst poison. Note that before and after treatment When the weight of the filler was measured and the amount of adsorption was determined from the weight difference, it was found that in the example, 3.9X 10-3 WT% was adsorbed.Subsequently, a predetermined weight of filler that had been adsorbed in this way was Two-component addition-reactive silicone gel y!, Kataru CF3
056 ()-Made by Dow Corning Silicone)
The mixture was added to each of Liquids A and B, and stirred to uniformly disperse the mixture. In addition, this silicone gel raw material contains A liquid, B liquid
A platinum-based catalyst is already mixed in one side of the liquid. Thereafter, the A and B liquids were mixed at a mixing ratio of 1:1, poured into a mold which was a cylindrical hole with a diameter of 19 mm and a depth of 11.5 mm, and after curing at 80°C for 1 hour, the mixture was further heated to 30°C at 30°C. It took time to harden. In addition, the total amount of filler is
35 νT% was added. Thereafter, it was left to cool at room temperature, and the cylindrical silicone gel was taken out from the mold, and used as an example sample for evaluation. On the other hand, as a comparative example, the above phyllite was not subjected to adsorption treatment,
After adding it as it was, a comparative sample was prepared in the same manner as in Example 1. The strain amount and vibration characteristics of these samples under static load were measured, and the damping ratio was calculated from the latter. The measurement results are shown in Table 1 and FIGS. 1 and 2. Table 1 A: Load (kg/piece) B: Resonance frequency (H2) C: Resonance magnification (d8) D: Distortion! (%) E: Damping ratio (ζ) As shown in the above results, according to the composite silicone gel material of the present invention, the relationship between load and strain was significantly improved to be more linear. Compared to a composite silicone gel material made by adding an untreated filler, the strain of the present invention does not increase rapidly and the Young's modulus remains almost constant even when the applied load increases. When the applied composite silicone gel material is incorporated into various types of equipment, for example as a vibration damping material, it becomes extremely easy to assemble. This is because the catalytic poison component adsorbed on the surface of the filler forms an uncured layer discontinuous with the hardened continuous phase at the interface of the filler in the hardened continuous phase of the silicone gel. It is speculated that this is because the mechanical bond between them was severed, allowing them to move freely. In addition, regarding the load dependence of the damping ratio, compared to conventional composite silicone gel materials, the damping ratio decreases less even in the high load region, and the resonance magnification is reduced, which is the original purpose of adding fillers. It becomes possible to manufacture and supply vibration isolating materials. In addition to improving the attenuation characteristics as in the embodiments, the present invention
Depending on the filler added, the conventional mechanical bond between the gel and filler is broken and both can move freely, resulting in a linear load-strain curve and a nearly constant Young's modulus. Improvements in properties are also expected with respect to other functions that should be caused by the erosion, such as buffering properties, conductivity, magnetism, piezoelectricity, etc.

【Effect of the invention】

As described above, with the composite silicone gel material of the present invention, the added filler is not restricted by the hardened continuous phase of the gel and has freedom of movement, while the hardened continuous phase of the gel itself is not directly continuous with the filler. Conventionally, as the load increased, the gel's load-strain curve drew a rapid curve due to the mechanical bond between the gel and the filler, indicating a rapid increase in gel hardness, but in a wider load range. As a result, the damping characteristics, which tended to deteriorate as the load increased, were significantly improved. Of course, depending on the filler added, the linearity of the load-strain curve can be maintained, and the Young's modulus can be maintained almost constant, thereby providing additional functions such as cushioning properties, conductivity, magnetism, piezoelectricity, etc. Improvements can also be expected in the characteristics of Furthermore, according to the method for producing a composite silicone gel material of the present invention, such a composite silicone gel material can be obtained extremely easily.

[Brief explanation of the drawing]

The figure shows the measurement results of strain amount and vibration characteristics under static load in Examples and Comparative Examples. This is a distortion amount curve, and FIG. 2 is a damping ratio-strain amount curve with the vertical axis representing the damping ratio and the horizontal axis representing the strain amount.

Claims (2)

[Claims] (1) A composite silicone gel material comprising a silicone gel obtained by curing a silicone gel stock solution and a filler scattered in this silicone gel, in which the silicone gel forms the whole as a hardened continuous phase, and the filler A composite silicone gel material, characterized in that a thin layer of an uncured silicone gel stock solution is formed at the interface, and a filler is supported through the layer. (2) At least on the surface of the filler, a substance selected from sulfur, phosphorus, tin-based compounds, or amine compounds that have a deactivating effect on a platinum-based catalyst as a hydrosilylation catalyst is applied in advance to the gas phase and/or liquid phase of the substance. a step of adsorbing the substance in the phase, a step of adding the filler adsorbed with the substance to the uncured silicone gel, and adding the filler to the uncured silicone gel using the platinum-based catalyst. 1. A method for producing a composite silicone gel material, comprising a step of reacting and curing the material.