DE1223549B - Process for the production of molded bodies, coatings or cement by hardening organopolysiloxane compounds - Google Patents

Description

Process for the production of moldings, coatings or cement by hardening organopolysiloxane compounds based on fillers and brushes of hard-like silicones, which are formed by stirring suitable fillers into such organopolysiloxanes or their solutions are produced, are for the production of molded parts or electrical insulation known. However, these putties were previously only in the warm hardenable, in the cold only gelling and no hardening occurred, even if metal soaps, amines or alkyl titanates were used as hardeners. These only gelled resin-like putty masses were in terms of surface hardness, Water resistance and solvent resistance very unsatisfactory: besides the adhesion of these putties to surfaces was generally insufficient.

The process according to the invention for the production of moldings, coatings or cementing by hardening organopolysiloxane masses, on the other hand, also leads to Room temperature to a complete hardening and to products with satisfactory Properties. The products prepared according to the invention adhere, for. B. very good on ceramic or metallic surfaces.

The process according to the invention for the production of moldings, coatings or cementing by hardening optionally organic solvents and / or Organopolysiloxane compositions containing color pigments based on about 10 to 70 percent by weight Organopolysiloxane (A), about 30 to 90 percent by weight of an inorganic or organic Filler (B), in the presence of about 1 to 10 percent by weight for curing condensation catalysts known per se from resinous organopolysiloxanes (C) and about 1 to 10 percent by weight of inorganic acid esters on the Si atom Free organic groups containing more than two condensable groups in the molecule Silicon compounds (D) at room temperature are characterized in that one as organopolysiloxanes (A) polymers with at least 0.5 mol percent silicon-bonded Hydroxyl groups and an R: Si ratio of 1: 1 to 1.7: 1, the organic Rests alkyl and / or aryl radicals can be used.

The method according to the invention was not obvious. It was true from the Belgian patent 550 105 already known that diorganopolysiloxanes with two condensable groups in the molecule by means of more than two condensable groups Groups in the molecule have organic silicon compounds applications and for hardening resinous organopolysiloxanes to condensation catalysts known per se Elastomers can be cured. However, it was also known that this curing process a crosslinking of uncrosslinked organopolysiloxanes represents and that organopolysiloxanes with an R: Si ratio of 1: 1 to 1.7: 1, i.e. H. so-called organopolysiloxane resins, are already strongly crosslinked or contain non-crosslinkable siloxane units. Consequently it is surprising that the use of one for organopolysiloxane elastomer manufacture known curing process based on the addition of small amounts of crosslinking agents based on resinous organopolysiloxanes, which, as is evident from the R: Si ratio from 1: 1 to 1.7: 1, are strongly networked from the start or already have many Contain crosslinkable siloxane units, is advantageous and the resinous organopolysilokanes opens up new areas of application. Finally, within the scope of the invention, too not simply resinous organopolysiloxanes used, but such organopolysiloxanes with not the usual high pigment content.

Organopolysiloxanes (A) suitable according to the invention are, for example those manufactured according to German patent specification 813 433 or 958702 are. The hydroxyl group content of these silicones must be at least 0.5 mol percent, to achieve sufficient hardening. The greater the hydroxyl group content of a silicone, the faster it cures. Basically, methyl or phenylsiloxanes useful; the higher the content of phenyl residues in a silicone is the more however, the hardening proceeds more slowly, so that in general pure methylsiloxanes are preferred.

Examples of suitable fillers (B) are: inorganic Fillers, such as asbestos flour, mica flour, quartz flour, vermiculite, calcium carbonate, titanium dioxide, Kieselguhr, precipitated or pyrogenic silicas obtained in the gas phase, zinc oxide, Magnesium oxide or iron oxide, also glass fibers, glass wool, rock wool or metal powder, and organic fillers such as carbon black, cork flour or sawdust. The filler content the mixtures can, based on the resin solids content, within wide limits vary. Mixtures of equal parts by weight of are preferably used Silicone and filler. Basic compounds such as zinc oxide are used as fillers or magnesium oxide, the hardening reaction is very accelerated.

Examples of suitable catalysts (C) include: metal soaps, such as tin ricinoleate or cobalt naphthenate, metal chelates such as chromium acetylacetonate, Metal salts of thiols or dithiocarbamic acids such as the lead salt of mercaptobenzothiazole or Zinkäthylphenyldithiocarbaminat, metal oxides such as mercury, cadmium or Lead oxide (PbO), organometallic compounds such as phenyl mercury acetate or dibutyl tin dilaurate or other dialkyltin diacylates, organic bases such as triethanolamine or polyethyleneimine or acidic compounds such as boric acid, especially organic acids such as oleic acid.

As examples of suitable more than two condensable groups Organic silicon compounds (D) in the molecule may be mentioned: or aryl ortho- or polysilicic acid esters or organopolysiloxanes, the hydrogen atoms wear on silicon. -Also granulate. Color pigments of all kinds in the required quantities can be added.

Furthermore, solvents can be used to adjust the consistency and the Pot life can also be used, whereby the catalysed pot life is extended Masses of oxygen-containing organic solvents, in particular esters, alcohols, such as butanol, or ketones are suitable.

The hardening is preferably carried out by adding 1 to 2 percent by weight, based on the silicone solid, a mixture of ethyl orthosilicic acid ester and dibutyltin laurate in a ratio of 1: 1.

- Methylhydrogen polysiloxane can also be used in place of ethyl orthosilicic acid ester be used.

Curing takes place in 30 minutes, depending on the amount of catalyst 3 hours. Faster curing generally occurs because the pot life is too short and because of the risk of shrinkage cracking with solvent-based compositions into consideration. The cured masses can go through in a manner not claimed here surface coating with a 5% solution of alkyl, e.g. butyl titanate, can be made even harder in a suitable solvent. The addition of butyl titanate to hardener liquid, or to mass itself prohibits itself because of the absorbing short pot life of such masses.

The masses can be applied to any surface, such as cement, plaster or. other silicate surfaces, wood or metal, by spraying, painting, speech teln or rollers are applied. To the; better adhesion to these surfaces a pre-priming of the surfaces with 200% solutions of alkyl titanate, silicic acid esters, Organosilicic acid esters or unfilled resinous organopolysiloxanes with reactive Hydroxyl resp.

Ethoxyl groups and the above R: Si ratio in acetone or gasoline attached.

The hardened masses show excellent heat resistance, great water and weather resistance, excellent abrasion resistance and excellent resistance to soaps or synthetic detergents. There if they are free of plasticizers, they do not become brittle even after prolonged storage. they are therefore and because of their surprisingly high abrasion resistance for siloxane products particularly good as a filler or coating compound for floors, walls, etc., where it depends on good heat, water and weather resistance, suitable.

As a result of their resistance to oil, water and ventilation they are also suitable as road marking paints and for sealing concrete and other building materials. They can also be used as joint putty for acid protection and for lining containers.

Example 1 1 kg of a 500 / above solution is mixed in a kneader of a resinous organopolysiloxane, which according to German patent specification 958702 has been produced, with 1 kg of a pigment mixture consisting of 2 parts of asbestos flour and 1 part quartz flour, and add 60 g of tetraethylsilicate and to this mixture 40 g of dibutyltin dilaurate. This mixture is then troweled onto cement plaster. It dries in about an hour and has its highest surface hardness after 12 Hours at room temperature. This filler covering produced in this way shows after 100 hours of boiling in water, water absorption of only 0.2%. The mechanical Properties. of the surface have not changed as a result.

Example 2 A resinous silicone that is 3.6 mole percent silicon-bonded Contains hydroxyl groups made by hydrolysis together of 33.3 mole percent Methyltrichlorosilane, 33.3 mole percent dimethyldichlorosilane, and 33.3 mole percent phenyltrichlorosilane in butyl acetate, was in a kneader with a mixture of quartz flour, asbestos flour and glass staple fibers of 3 mm in length in the ratio 1: 2: 0.5 in such an amount added that the finished mixture contained 30% filler. This mixture were then 10% of a solution of 2 parts of tin ricinoleate and 2 parts of dibutyl monoacetate in 6 parts of hexaethoxydisiloxane added. Subsequently, the thus obtained Putty for lining the joints in sandstone slabs. Used: The putty dried non-sticky after 11/2 hours at room temperature and reached its maximum hardness after 6 days at room temperature. When this putty becomes a 600% solution in a mixture was dissolved from 2 parts of toluene and 1 part of butanol, it was spreadable and suitable as road marking paint. The paint dried within 30 minutes at room temperature, so that the drive can be driven on again without damage, Could, and showed after 6 months Ventilation and driving on no signs of yellowing or wear and tear on a busy street.

Claims (1)

Claim: Process for the production of moldings, coatings or cementing by hardening, optionally organic solvents and / or organopolysiloxane compositions containing color pigments based on about 10 to 70 weight percent organopolysiloxanes (A), about 30 to 90 weight percent one inorganic or organic filler (B) in the presence of about 1 to 10 percent by weight on condensation catalysts known per se for curing resinous organopolysiloxanes (C) and about 1 to 10 percent by weight of inorganic acid esters on the Si atom free organic groups having more than two condensable groups in the molecule Silicon compounds (D) at room temperature, characterized in that one as Organopolysiloxanes (A) Polymers with at least 0.5 mol percent silicon-bonded Hydroxyl groups and an R: Si ratio of 1: 1 to 1.7 1, the organic Rests alkyl and / or aryl radicals can be used. Documents considered: German Auslegeschrift No. 1,254; Belgian patent specification No. 550 105.