Fumed silanized silica

The present invention relates to silaneized fumed silica, a method for producing the same, and the use thereof.

Humed silica (silicon dioxide produced by the pyrolysis method) is known from Ullmanns Enzyklopaedie der technischen Chemie, Vol. 21, p. 464 (1982).

The fumed silica is produced by burning an evaporable silicon compound, such as silicon tetrachloride, in a mixture of, for example, hydrogen and oxygen.

Milling of materials to form coarse powders (50-50 μm), fine powders (5-50 μm) and uniform, more pronounced fineness (less than 5 μm) is a generally widespread practice. For all milling operations, there are a variety of technical and industrial equipment provided and operated, all adapted to the specific environment of the special operation. A good overview of the problem of milling and the various machines is given in Ullmanns Enzyklopaedie der technischen Chemie, 3rd Edition, Volume 1, pp. 616-638.

For fumed silica, its average primary particle diameter is significantly smaller (5-50 nm) than can be obtained by mechanical milling.

Surface area 200m²Primary particles and agglomerates of fumed silica with / g can be visualized with an electron microscope.

The primary particles and aggregates of fumed silica aggregate to form larger aggregates, the size of which is generally inversely proportional to the primary particle size or proportional to the specific surface area. There is. The size of the agglomerates also increases in line with the range for compressing fumed silica.

The binding force that holds the agglomerates together is relatively weak. Nevertheless, when those agglomerates are incorporated into a liquid system for uniform distribution of primary particles and agglomerates, or particles with a low degree of agglomerates, and are destroyed in the liquid system. Specific shear energy is required. Depending on the particular area of application, dispersion is carried out using any very wide variety of mixers, where the determinants for selection are not only the viscosity and polarity of the system, but also aggregation. It is also the strength and desired uniformity of the mass.

For simple stirring mechanisms, such as paddle-shaped stirrers, it is usually not possible to perform to satisfy the direct uptake of small amounts of silica, especially if the system in question is not of low viscosity. However, paint and varnish manufacturers, and also those who perform the treatment, are also used by very simple equipment, mainly as thickeners and thixotropes, with very low energy input and in a very short time. I am interested in obtaining the optimum distribution for the performance of silica.

In the case of paddle-shaped stirrer dispersion, the coarse silica agglomerates are not sufficiently milled and can therefore make only a small contribution to the increase in viscosity and thixotropy. The data is related to UP resin (unsaturated polyester resin) as a dispersion medium.

It is only possible to reduce the size of the agglomerates by dispersion outside the range of the liquid system, in other words, in the air or by grinding in the usual sense. This is because, in the case of substances that have a predetermined tendency towards agglomerates, milling is immediately followed by restoration of the old agglutinating state. This effect undergoes a high degree of loosening as a result of mechanical involvement and no longer occurs after recompression of materials that are not applicable to delivery and storage in this form. Moreover, the storage period may have the effect of increasing the regenerated agglomerates.

The variable number of dimensions and the values taken as measurements for the stage of distribution of the size (granularity) of the largest agglomerates of dispersible silica and dispersion is the so-called grain gauge value for DIN 53203<u style="single">(Grind meter value)</u>Is.

Known methods are to provide hydrophobic fumed silica, grind it in a pinned disc mill, and classify it (USA 2004/0110077 A1).

This known silica is used as an external additive in the toner mixture.

Hydrophilic fumed silica with BET surface area has a grain gauge value of 50-60 as measured according to DIN standards in UP resin (BASF unsaturated polyester resin Ludepal P6, 2% dispersion).

Even when this fumed silica is compressed relatively higher (100-120 g / l), the grain gauge value is also much higher, especially above 100, thereby thickeners and thixotropes. Requires an additional significant amount of energy as.

The known method is about 300m²Highly dispersed silica with a surface area of / g is ground in a pinned disc mill.

The grain gauge value achieved is initially 25 for uncompressed silica.

When this silica is compressed to 50 g / l, the grain gauge value increases to 30, and when further compressed to 75 g / l, it increases to about 40.

For storage for 3 months, the ground silica is not modified, but is compressed to 50 g / l and has a grain gauge value of 50-60.

Only reaggregation can be avoided according to the prior art when hydrophilic silica is mixed with 3% by weight of hydrophobic silica and when the mixture is ground by an air jet mill or pinned disc mill. (EP 0 076 377 B1).

In this case, BET surface area 200m²For fumed silica with / g, a grain gauge value of 35 is obtained even after compression to 73 or 107 g / l.

BET surface area 300m²For fumed silica with / g, the addition of hydrophobic silica before grinding has a grain gauge value of 10 for a tamping density of 28.1 g / l and 15-20 for a tamped density of 50 g / l. Produces.

Known fumed silica has the drawback of containing an undesired fraction of hydrophobic silica.

The present invention provides silaneized fumed silica characterized by having the following physicochemical data: Grain gauge value less than 20 μm Compaction density 25 ~ 85g / l

Furthermore, the present invention is characterized by a surface-fixed group, wherein the group is dimethylsilyl and / or monomethylsilyl, preferably dimethylsilyl, silylated, structurally modified. Provided is a method for producing silica of the present invention, which comprises pulverizing the produced fumed silica.

In one preferred embodiment of the invention, the silica used can have the following physicochemical data: BET surface area m²/ g: 25 ~ 400 Average primary particle size nm: 5 ~ 50 pH: 3 ~ 10 Carbon content%: 0.1 ~ 10

Humed Silica, Winnacker-Kuechler Chemische Technologie, Vol. 3, (1983), 4th Edition, p. 77 and It is known from Ullmanns Enzyklopaedie der technischen Chemie, 4th Edition (1982), Vol. 21, p. 462.

Humed silica is particularly evaporable silicon compounds such as SiCl.₄, For example, or produced by flame hydrolysis of organosilicon compounds such as trichloromethylsilane.

The silicified fumed silica used according to the present invention can be produced by treating fumed silica with dimethylchlorosilane and / or monomethyltrichlorosilane in a known manner, in which case dimethylsilyl. And / or the monomethylsilyl group is immobilized on the surface of fumed silica.

In one particular embodiment of the invention, the first silica used can be fumed silicon dioxide hydrophobicized with dimethyldichlorosilane.

Milling of the silaneized fumed silica can be done by a pinned disc mill or an air jet mill.

The silica of the present invention does not show a tendency toward reaggregation. Its grain gauge value is less than 20.

The fumed silica of the present invention is a silicone rubber as a filler.<u style="single">compound</u>Can be used in.

silicone rubber<u style="single">compound</u>, And silicone rubber<u style="single">compound</u>The use of fumed silica (AEROSIL®) in is known (Ullmann, Encyclopaedia of Industrial Chemistry, A Vol. 23, Rubber, 1, 221 ff .; Rubber 3, 3, 6 ff .; A 24. Volume, Silicones 57 ff. 1993).

Fumed silica is used for its excellent thickening effect (thixotropy) in silicone sealants, where this thickening effect is adhesive.<u style="single">compound</u>It is desirable in the description content of use as.

However, silicone rubber<u style="single">compound</u>However, low levels of thickening are desirable when they can be used as paint materials (US Pat. No. 6,268,300).

Of critical importance in both cases is the visual properties of the surface of the silicone vulcanized product.

Therefore, an object of the present invention is a silicone rubber that visually exhibits a high quality surface after vulcanization through the use of fumed silica as a filler.<u style="single">compound</u>Is to provide.

The present invention provides a silicone rubber compound containing 0.5% by mass to 60% by mass of fumed silica of the present invention having physicochemical data of the following properties with respect to the total mass: Grain gauge value less than 20 Tampling density 25 ~ 85g / l as well as For the total mass, the formula,<chemistry num="1"><img file="JP5114425B2_D0001.tif" /></chemistry>[In the formula, R has 1 to 50 carbon atoms, is unsubstituted or substituted with O, S, F, Cl, Br, I, and is the same or different in each case, alkenyl, alkoxy, aryl, Oxime, acetoxy, alkyl groups, and / or polystyrene, polyvinylacetate, polyacrylate, polymethacrylate and polyacrylonitrile groups with repeating units of 40 to 10000. Z is an OH, Cl, Br, acetoxy, amino, amineoxy, oxime, alkoxyamide, alkenyloxy, acrylicoxy or phosphate group, wherein the organic group can have up to 20 carbon atoms. And in each case the same or different, Z'is oxime, alkoxy, acetoxy, amino, amide, n is 1 to 3 x is 100 to 15000] Organopolysiloxane 40% by mass to 99.5% by mass.

As the organopolysiloxane, any polysiloxane used or can be used in the data as the basis for the room temperature crosslinked (room temperature vulcanization) (RTV) composition can be used. They are, for example, general expressions<chemistry num="2"><img file="JP5114425B2_D0002.tif" /></chemistry>May be described by, where x, R, Z'and Z have the following definitions: R has 1 to 50 carbon atoms and is unsubstituted or<u style="single">O</u>, S, F, Cl, Br, I, and in each case the same or different alkenyl, alkoxy, aryl, oxime, acetate, alkyl group, and / or polystyrene, polyvinyl with 40-10000 repeating units. Acetate, polyacrylate, polymethacrylate<u style="single">Or</u>It is a polyacrylonitrile group.

Z is an OH, Cl, Br, acetoxy, amino, amineoxy, oxime, alkoxyamide, alkenyloxy, acrylicoxy or phosphate group, wherein the organic group can have up to 20 carbon atoms. And are the same or different in each case.

Z'is oxime, alkoxy, acetoxy, amino, amide, n is 1 to 3 x is 100 to 15000.

Within and / or along the siloxane chain in the formula shown above, they are usually only as impurities in the form of diorganosiloxane units, such as the formula, RSiO._3/2, R₃O_1/2And SiO_4/2In the formula, R can also be another siloxane unit that exists in the form shown in [in each case, having the definition shown above]. The amount of these other siloxane units should not exceed 10 mol%.

Examples of R for the definition of alkyl groups are, for example, methyl, ethyl, propyl, hexyl and octyl groups; possible alkenyl groups are vinyl, allyl, ethylallyl and butazienyl groups; and as aryl groups, phenyl and tolyl groups. Can be used.

Examples of substituted hydrocarbon groups R are particularly halogenated hydrocarbon groups such as 3,3,3-trifluoropropyl groups, chlorophenyl and bromotril groups; and cyanoalkyl groups such as β-cyanoethyl groups.

Examples of polymers as free radical R are polystyrene, polyvinyl acetate, polyacrylate, polymethacrylate and polyacrylonitrile groups attached to silicon via carbon.

For the easiest use, the major fraction of free radical R is composed of methyl groups. Other free radicals R are, in particular, vinyl and / or phenyl groups.

Z and Z'are hydrolyzable groups, especially in the presence of formulations that can be stored in the absence of water and that cure to elastomers against the ingress of water at room temperature. Examples of such groups are acetoxy, amino, amineoxy, alkenyloxy (eg H).₂C = (CH₃CO-)), acyloxy and phosphate groups. In essence, for the easiest use, the preferred group Z is an acyloxy group, especially an acetoxy group. However, good results are also obtained, for example, with oxime groups, eg formula -ON = C (CH₃) (C₂H₅) Can also be obtained by using the oxime group as Z. Examples of hydrolyzable atoms Z are halogen and hydrogen atoms; examples of alkenyl group Z are especially vinyl groups.

The viscosity of the organopolysiloxane used in the description of the present invention should not exceed 500000 cP at 25 ° C, preferably 150,000 cP at 25 ° C. Therefore, the value x should not, advantageously, exceed 40,000.

Examples of organopolysiloxanes that can be used are, for example, the silicone polymer E50 (α, ω-hydroxydimethylsiloxypolydimethylsiloxane) or M50 (α, ω-hydroxydimethylsiloxypolydimethylsiloxane) manufactured by GE Bayer Silicones.

Mixtures of various organopolysiloxanes can also be used.

Mixing of the organopolysiloxane with fumed silica and, where appropriate, with other constituents of the formulations of the invention can be carried out in any desirable known manner, eg, in a mechanical mixing apparatus. .. It is achieved very quickly and easily, regardless of the order in which the mixed ingredients are added.

Advantageously, the fumed silica of the present invention can be cured to an elastomer.<u style="single">compound</u>It is used in an amount of 0.5% by mass to 60% by mass, preferably 3% by mass to 30% by mass, based on the total mass of.

Further, the diorganopolysiloxane is crosslinked when only the reactive terminal units present in the diorganopolysiloxane containing the reactive terminal units are the reactive terminal units having a Si-linked hydroxyl group. Should be. This can be done in the usual way by the water present in the air, additionally with other water as needed, with a cross-linking agent. In the present specification, for example, Silopren cross-linking agent 3034 manufactured by GE Bayer Silicones, ethyltriacetoxysilane, can be used in a known method in the presence of a concentration catalyst, in some cases. Suitable catalysts for all formulations of the present invention are, for example, Silopren catalyst DBTA or type 162 dibutyltin diacetate or dilaurate, manufactured by the same manufacturer.

Silicone rubber of the present invention<u style="single">compound</u>In one particular variant of<u style="single">compound</u>For the total mass of<chemistry num="3"><img file="JP5114425B2_D0003.tif" /></chemistry>[In the formula, R has 1 to 50 carbon atoms and is unsubstituted or substituted with O, S, F, Cl, Br, I and the same or different in each case, alkyl, alkoxy, acetoxy, Oxime, aryl, alkoxy groups, and / or polystyrene, polyvinylacetate, polyacrylate, polymethacrylate and polyacrylonitrile groups with repeating units of 5 to 5000. Z'is an OH, Cl, Br, acetoxy, oxime, amino, amineoxy, alkenyloxy or phosphate group, in which the organic group can have up to 20 carbon atoms, in each case. Same or different in t can be 0.5% to 20% by weight, preferably 2% to 10% by weight, of the cross-linking agent having [3 or 4].

All mass data is silicone rubber<u style="single">compound</u>It is related to the total mass of.

Examples of silanes of the formula shown above are ethyltriacetoxysilane, methyltriacetoxysilane, isopropyltriacetoxysilane, isopropoxytriacetoxysilane, vinyltriacetoxysilane, methyltrisdiethylaminooxysilane, methyltris (cyclohexylamino) silane. , Methyltris (diethyl phosphate) silane and methyltris (methylethylketoximo) silane.

Of course, the formulations of the present invention can be further cured to organopolysiloxanes, hydrophobized silicas, cross-linking agents and cross-linking catalysts, and if desired, elastomers.<u style="single">compound</u>Can include fillers that are commonly or frequently used in. An example of such a substance is a surface area of 50 m.²Fillers with less than / g, such as coarse quartz powder, kaolin, phyllosilicates, clay minerals, diatomaceous soil, plus zirconium silicates and calcium carbonate, as well as silicon dioxide, organic produced by untreated thermal decomposition methods. Resins such as polyvinyl chloride powder, organopolysiloxane resins, fibrous fillers such as asbestos, fiberglass, and organic pigments, soluble dyes, perfumes, corrosion inhibitors, curing inhibitors such as benzotriazole, and reversible agents such as trimethyl. It is a dimethylpolysiloxane whose end is blocked by a siloxy group.

In some cases, the RTV 1K [single component system] silicone rubber of the present invention<u style="single">compound</u>Containing 0.1% to 20% by weight (relative to the total amount of the (water-binding material) formulation), preferably 0.1% to 15% by weight, particularly preferably 0.1% to 10% by weight sell. Suitable substances for this purpose are, for example, acetic anhydride or maleic anhydride, and / or carbonic acid esters such as diethyl carbonate, ethyl carbonate, and / or alkenyloxy compounds, and / or ketals such as dimethyl. Dioxolane. One or more of those substances can be used.

Furthermore, the silicone rubber<u style="single">compound</u>May contain 0.01% by weight to 99.5% by weight of defunctionalized polysiloxane. Non-functionalized polysiloxanes already specified and provided can be used herein. One suitable non-functional polysiloxane is, for example, Baysilone oil M1000 (polydimethylsiloxane) manufactured by GE Bayer Silicones.

Furthermore, the silicone rubber<u style="single">compound</u>0.01% to 6% by weight of organic or inorganic compounds of metals Pt, Sn, Ti and / or Zn as catalysts, and / or 0.01% to 6% by weight of inhibitors, and / or fungicides and / or Disinfectant 0.01% to 6% by weight and / or fixer (eg, composition: Silopren fixer from GE Bayer Silicones with di-tert-butoxydiacetoxysilane) 0.01% to 6% by weight May contain. As the fungicide / fungicide, for example, isothiazolinone, Vinycin or benzisothiazolinone can be used.

Silicone rubber of the present invention<u style="single">compound</u>Is a one-component (1K RTV) silicone rubber sealant that is vulcanized at room temperature, and a self-leveling silicone rubber that is crosslinked at room temperature.<u style="single">compound</u>Can be used as a silicone rubber system from the (1K RTV) group.

The silicone rubber<u style="single">compound</u>Is glued<u style="single">compound</u>Can be used as sealants in window sealants, automobiles, sports equipment and household appliances, heat resistant seals, oil bleeding and chemical resistant seals, and water vapor resistant seals, as well as seals in electrical and electronic products.

The silicone rubber<u style="single">compound</u>Can be used as a paint material for woven fabrics, such as lace tape (anti-slip), and woven materials, such as fiberglass or nylon fiber woven fabrics.

Silicone rubber of the present invention<u style="single">compound</u>The vulcanized product has an advantageously high quality surface.

The embodiments according to the invention are performed by weighing and supplying industrial AEROSIL® R 972 (bagged product) using a weighing balance in a mill used and subject to grinding. Been formed. The physicochemical data for AEROSIL® 972 are listed in Table 1.

The manufacturing method parameters are listed in Table 2.

The experiment was carried out using a pinned disc mill (Alpine 160Z, rotor diameter 160 mm) or an air jet mill (crushing chamber diameter: 240 mm, grinding chamber height: 35 mm). Hose filter for crushed material (filter area: 3.6 m)², Filter material: Nylon fiber woven fabric) separated. In another experiment, the resulting pulverized material was packed in a conventional commercial bag using a conventional commercial bagging machine. In other experiments, bags filled with crushed material were homogenized prior to palpitation, using methods that are common in the industry and stable for purposes.

<u style="single">Table 1:</u><u style="single">Humed silica used</u><tables num="1"><img file="JP5114425B2_D0004.tif" /></tables>

<u style="single">Table 2:</u><u style="single">Manufacture of parameters according to an embodiment of the present invention</u><tables num="2"><img file="JP5114425B2_D0005.tif" /></tables>

<u style="single">Table 3:</u><u style="single">Physicochemical data of the silica of the present invention and comparative examples</u><tables num="3"><img file="JP5114425B2_D0006.tif" /></tables>

For nearly identical specific surface area and unchanged pH values, the milled product data show lower grain gauge values. Surprisingly, lower grain gauge values are maintained, despite compression, as a result of bagging or bagging / homogenization, clearly through the tamping density.

In some cases, the tamping density is actually higher than the tamping density of the oxide used, i.e. the oxides of the invention have lower grain gauge values, despite the same or higher compression. Is shown.

<u style="single">Table 4:</u><u style="single">Particle size measurement by measuring TEM micrographs</u><tables num="4"><img file="JP5114425B2_D0007.tif" /></tables>

The fumed silica of the present invention may have a D50 (g) of 25.7 to 35.0 nm (ie, median mass distribution).

The total length of the particles can be 2.500 to 87.140 nm.

The average particle diameter, DA, for surface area can be 23.0-30.9 nm.

The average particle diameter, DV, for volume can be 26.5-40.0 nm.

Figures 1-8 show a graphical representation of the distribution measured for silica in Example 1 (according to the present invention) and Comparative Examples.

<u style="single">Table 5:</u><u style="single">Particle size measurement with Cilas</u><tables num="5"><img file="JP5114425B2_D0008.tif" /></tables>

The silica of the present invention may have a d50 value of 4.5-7.0 μm as measured by Cilas.

B<u style="single">E</u>T surface area BET surface area is measured according to DIN ISO 9277.

Tampling density The tamping density is measured according to DIN EN ISO 787-11.

Principle of measuring tamping density: The tamping density (formerly tamped volume) is equal to the mass ratio of the tamped powder to the volume of the tamped powder under defined conditions on a tamping volume meter. According to DIN ISO 787 / XI, the tamping density is g / cm³Reported at. However, due to the very low tamping density of the oxide, it shows a value at g / l. In addition, repeated drying and sieving and tamping methods are omitted.

Equipment for measuring tamping density: Tamping volume meter Graduated cylinder Laboratory balance (reading accuracy 0.01 g)

How to measure tamping density: Introduce 200 ± 10 ml of oxide into the graduated cylinder of the tamping volume meter so that there are no remaining cavities and the surface is horizontal.

Determine the mass of the introduced sample to an accuracy of 0.01 g.<u style="single">Trial</u>Insert the graduated cylinder containing the charge into the cylinder holder of the tamping volume meter, and tamper 1250 times.

Read the volume of the tamped oxide to an accuracy of 1 ml.

Evaluation of tamping density measurement:<maths num="1"><img file="JP5114425B2_D0009.tif" /></maths>

pH Reagents for pH measurement: Distilled or deionized water with pH&gt; 5.5 Methanol, pa Buffer pH7.00 pH4.66

Equipment for pH measurement: Laboratory balance (reading accuracy 0.1 g) Glass beaker, 250 ml Porcelain stirrer Porcelain rod length 4 cm Mixed pH electrode pH meter 100 ml dispenser

How to measure pH: The measurement is performed by the improved method of DIN EN ISO 787-9.

Calibration: Prior to pH measurement, the meter was calibrated with buffer. One calibration is sufficient if two or more measurements are made sequentially.

Cover 4 g of oxide with 48 g (61 ml) of methanol in a 250 ml glass beaker, and dilute the suspension with 48 g (48 ml) of water, with pH electrode, porcelain stirrer (about 1000 min).^-1Use (speed of) and stir for 5 minutes.

After turning off the stirrer, its pH is read after leaving it for 1 minute. The results are summarized in one digit after the decimal point.

Grain gauge value principle: The degree of dispersion determines the performance characteristics of Aerosil-concentrated liquids. Measuring the grain gauge value provides an assessment of the degree of dispersion. With respect to the grain gauge value, it represents the thickness of the boundary layer less than the thickness at which existing particles or agglomerates become visible on the surface of a fully covered sample.

The sample is completely covered with a scraper in a groove where the groove depth at one end is twice the diameter of the largest Aerosil particle and, on the other hand, is steadily decreasing to zero. For a scale indicating the depth of the groove, the depth value is read in micrometers, where the value in question is that a relatively large number of Aerosil particles are a small piece or piece on the surface of the adhesive system. Less than the value that becomes visible as a result of scratches. The value read is the grain gauge value of the system present.

Equipment and reagents: Hegmann grain gauge with a depth range of 100 to 0 micrometers. Polyester resin dispersion with 2% Aerosil, manufactured by Testing Instruction 0380.

procedure: The grain gauge block was placed on a horizontal, non-slip surface and wiped clean just before testing. The Aerosil dispersion, which should not have air bubbles, is then applied to the deepest point of the groove in a way that flows out to some extent beyond the edge of the groove. The scraper is then supported by both hands and placed at the end of the groove in which the dispersion is placed, at a gentle pressure, perpendicular to the grain gauge block and perpendicular to the vertical edge. The dispersion is then slowly coated in the groove by covering the block and uniformly removing the scraper. The grain gauge value is read by 3 seconds after the dispersion is coated.

View the surface of the diffused dispersion (sideways to the groove) at an angle of 20 to 30 ° (with respect to the surface) from the top. The block is fixed to light in such a way that the surface structure of the diffused dispersion is effortlessly obvious.

The grain gauge value read for the scale is a value in micrometers, less than the value at which a relatively large number of Aerosil particles become visible as small pieces or scratches on the surface. Random individual pieces or scratches are not included in the reports herein.

Its particle size is evaluated at least twice in each case for the newer diffused dispersion.

Rating: Make an arithmetic mean from the measured values. The relationship between the grain gauge value in micrometers and the FSPT and Hegmann units based on the inch system is as follows: B = 8-0.079A C = 10-0.098A = 1.25B

In this relationship: A = Grain gauge value at micrometer Grain gauge value in B = Hegmann unit Grain gauge value in C = FSPT unit

<u style="single">II. Manufacture of silicone rubber compound</u> 1. General experimental method a) Principle Silicone for testing<u style="single">compound</u>The corresponding performance characteristics of AEROSIL® in RTV1 silicone sealant are manufactured for standard formulations on laboratory balances.

b) Equipment<u style="single">Planetary gear melters should meet the following requirements:</u>The stirring vessel provides a jacket having a capacity of about 2 liters and having a cooling water junction. The planetary gear device and the melting device are independent. They must have a decompression pump. An additional drum press facilitates product transport. Removal for cleaning purposes should be rapid.

c) Formulation 62.4% silicone polymer Silopren E 50 (manufactured by GE Bayer Silicones) 24.6% silicone oil Silicone Oil M 1000 (manufactured by GE Bayer Silicones) 4.0% acetate crosslinker Crosslinker AC 3034 (manufactured by GE Bayer Silicones) 1.0% fixer Fixing agent AC 3001 (manufactured by GE Bayer Silicones) 0.01% dibutyltin diacetate catalyst 8.0% fumed silica AEROSIL (registered trademark) (manufactured by Degussa AG)

d) Procedure Weigh 468.0 g of silicone polymer, 184.5 g of silicone oil, 30.0 g of cross-linking agent and 7.5 g of fixing agent in a stirring container, and 50 rev min for 1 minute.^-1Speed planetary gears and 500 rev min^-1Uniformize with a melting machine at the speed of.

Then, 60 g of silica is taken up in two sets (about 30 g each) at the same speed, and the time required for wetting is measured.

As soon as the silica is completely moist, apply a reduced pressure of about 200 mbar, and disperse, 100 rev min for 5 minutes.^-1Planetary gears and 2000 rev min^-1Perform with the dissolution device at.

A drum press is used to transport the sealant in two aluminum tubes.

Silicone rubber obtained by this method<u style="single">compound</u>Is coated using a doctor blade and vulcanized within 24 hours at room temperature in ambient air. The surface of the vulcanizer is evaluated visually and according to the evaluation points: Rating: 1 = very good, 2 = good, 3 = sufficient, 4 = insufficient, 5 = lack

Surprisingly, when the silicas from Examples 1, 3, 4, 6, 7 and 9 are used, the silicas, in some cases, usually have lower grade surface quality compared to the standard material. Guide<u style="single">Ku</u>Despite the fact that it may have a very high tamping density, good surface properties of silicone vulcanizers are obtained. The surface of the silicone vulcanized product with the standard material fills slightly.

<u style="single">Table 6: Characteristics of non-crosslinked sealants</u><tables num="6"><img file="JP5114425B2_D0010.tif" /></tables>

<figref num="1">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="2">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="3">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="4">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="5">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="6">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="7">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref><figref num="8">The schematic which shows the distribution measured with respect to the silica of Example 1 and the comparative example by a graph display.</figref>