DE834002C - Process for surface treatment of glass and the like like - Google Patents

Description

Methods of surface treatment of glass and the like The present The invention relates to a method to produce raw materials, d. H. solid or fibrous objects, to make water repellent.

Although the procedure is practically any organic or inorganic Material is applicable, but it is preferred only for those basic materials, which have a pebble character, such as glass or glazed or enamelled objects, Porcelain, asbestos, quartz, mica and the like are used. It is known that the surfaces of the substances mentioned are hydrophilic and usually have a solid on the surface have adsorbed moisture film. This is often disruptive and makes it desirable to make these surfaces water repellent. For example, it is common to Glass fibers with oils, waxes or the like. To treat during manufacture to the Remove the glass surface from the action of moisture, thereby reducing losses to avoid tensile strength due to friction. The substances just mentioned are under effective under restricted conditions, but can be displaced by water that is opposite Glass has a greater affinity than the substances mentioned the tensile strength of moist fibers is relatively low compared to dry ones Fibers. It therefore seems appropriate to have a material that makes the glass water-repellent makes to prevent a decrease in the tensile strength of glass fibers, though these get damp. Another example of the perishable effects of moisture is the loss of the high electrical surface resistance in glass insulators, if they are exposed to humidity, rain or the like. This is particularly true This also applies to glass threads with their extremely large surface area per unit volume. A material, which helps reduce the high electrical surface resistance to obtain, is therefore highly desirable. Further perishable effects from moisture are too well known to be explained in more detail here.

The present invention is an improved method, in order to generally make non-water-repellent base materials water-repellent.

The invention is specifically directed to pebble-like objects not to make it wettable, in contrast to the high electrical surface resistance To maintain moisture.

Another advantage of the method according to the invention is friction to prevent and to increase the flexural strength as well as the electrical surface resistance from fibers or fibrous textiles made of glass.

It was found that the deficiencies outlined at the beginning thereby Can be turned off if these basic materials with one or more organosilane compounds those from the class of hydrolyzable organosilanes, their hydrolyzation products or their polymerized, hydrolyzed products.

Among hydrolyzable organosilanes are derivatives of SiH4, the hydrolyzable radicals such as halogen, amino groups, alkoxy, aroxy and acyloxy radicals etc., are understood, with the residual valencies of the silicon atom through organic radicals that are bonded to silicon by carbon atoms are saturated will. Examples of such organic radicals are as follows: Aliphatic Radicals such as methyl, ethyl, propyl, isopropyl, butyl, amyl, hexyl, heptyl to octadecyl and higher; alicyclic radicals such as cyclopentyl, cyclohexyl, etc.; Aryl and Alkaryl radicals, such as phenyl, mono- and polyalkylphenyls, such as tolyl, xylyl, mesityl, Mono-, di- and triethylphenyls, mono-, di- and tripropylphenyls, etc.; Naphthyl, Mono- and polyalkylnaphthyls, such as methylnaphthyl, diethylnaphthyl, tripropylnaphthyl etc .; Tetrahydronaphthyl, anthracyl, etc.; Aralkyl, such as benzyl, phenylethyl, etc. ; Alkenyl such as methallyl, allyl, etc. and heterocyclic radicals. The above organic radicals can also, if desired, inorganic substituents, such as z. B. halogen, etc. included.

The hydrolysis of the silanes described above leads to the corresponding Hydroxysilanes, d. H. Silanols, which in certain cases can be isolated. Mostly, however, the silanols condense especially in the heat to form polymers to form, which then contain one or more Si-O-Si groups. These polymers can still be increased by treatment with acids, alkalis or air Polymers are polymerized. According to the invention, the hydrolysis products and the higher polymers of a mixture of organosiloxanes are used. The hydrolysis product of such a mixture is usually a copolymer, which contains varying amounts of differently substituted organosilanes. Summary oath it can therefore be said that all these compounds and mixtures of organosilanes, their hydrolysis products and their polymerized hydrolysis products represent valuable, water-repellent products. The subject of the invention is Use of these compounds for the stated purpose of surface treatment of glass, porcelain, etc.

These organosilicon compounds can be prepared by dipping or spraying or other application both in liquid form and in solution to the objects to be treated are applied. The liquid compounds can can also be vaporized by blowing air or steam through them, and those to be treated Objects can become coated by exposure to these vapors. The liquid products can also be vaporized by heat or negative pressure and the vapors are brought into contact with the substances to be treated.

An excess of the organosilicone compounds can be used if desired appears by washing or rinsing the treated surface with fresh solvents be eliminated. After this treatment there remains a film that is likely is not thicker than several molecular layers and the very firmly attached to the treated Surface is adsorbed and makes it water-repellent.

The adhesive strength of the organosilicon compounds, especially when they are represent a hydrolysis product or a polymerized hydrolysis product, is increased by adding traces of a polymerization catalyst, preferably an acid or alkali before the objects to be treated come into contact with it to be brought. If the material to be treated is glass, it is advantageous to use it wash, rinse and dry beforehand in a strong acid such as hydrochloric acid, before it is brought into contact with the organosilicon compounds. It was found that the organosilicon; connections have greater adhesion to glass if the glass surface has been treated with acid beforehand.

It was further found that the effect of the treatment and the Adhesion of the film is increased when the treated objects are at temperatures are heated that are below the boiling point or the decomposition temperature of the Silicone compounds lie. A heating time of several minutes to one Hour is enough. For some inexplicable reason, this heating renders the invisible Film not eliminated, on the contrary, it seems to be improved in stability. At the same time, this also increases the water-repellent properties of the film. The best results are obtained with the use of organosilicon halides, the higher alkyl radicals, preferably those containing seven or more carbon atoms, such as heptyl, lauryl, octadecyl, etc. contain.

The following examples are intended to illustrate the invention without affecting it is limited in its full scope, explain in more detail.

Example i A beaker is covered inside with a cloth that is covered with a Solution of isoamyltrichlorosilane in benzene moistened is rubbed out. The inside of the beaker cannot be wetted, and if water is boiled in it, the wall of the glass is covered with vapor bubbles that are constantly forming and climb up. Liquids that are heated in such a beaker tend to be then no longer for pushing.

Example 2 A glass capillary is created inside by flowing through a Treated benzene solution of phenylethylsilane. The capillary tube thus treated is together with untreated tubes that have the same inner diameter, immersed in distilled water. The rise in water in the treated capillary is only three quarters of the height of the untreated capillaries. this clearly shows that the inner surface of the treated glass capillary is water-repellent has become, and that by the treatment the surface tension between water and glass has changed. Example 3 Diphenylsiloxane contained in a bottle is, similar to steam distillation, is evaporated by steam. If the escaping vapors are passed into a glass flask for a short time, so the inner surface of the piston becomes water-repellent. Used in place of diphenylsiloxane a phenylethylsiloxane evaporates in the same way, and the vapors are in passed another clean glass flask, the result is the same again, d. H. the inner surface of the piston thus treated has become water repellent.

Example ¢ The water-repellent properties of organosubstituted silicone compounds, when they are applied to glass fiber yarn, are demonstrated by the following tests: When carrying out the test, the yarn is passed over a freely rotating steel mandrel with a diameter of ½ inch, about 3.2 mm at a tension of 0.277 kg. If the yarn breaks the test is terminated The tests are carried out first using a dry yarn and then with a yarn over which water is poured while the yarn is being bent over the mandrel . With dry, untreated yarns 700 to 100 bends are achieved. If, however, the untreated yarn is wet, the yarn breaks after 3o to 40 bends. If, however, the yarn is treated with a dilute solution of phenylethylsiloxane in toluene, those treated in this way keep dry Threads 2ooo to 3000 bends and wet threads 65o to 1200 bends to the point of breaking. If the yarn is dime treated with thylsiloxane, the dry threads can withstand 1,600 to 1,700 bends and the wet threads 6oo to 8oo bends.

Example 5 A hydrofluoric acid pretreated, distilled The glass plate, rinsed with water and dried, is treated with an 8% solution of methyltriethoxysilane treated in benzene. The plate treated in this way is then exposed to a jet of water and when taken away by the jet of water it appears to be wet, though the water drained from the treated surface first. Another glass plate is treated similarly, but then heated to 22o ° C for 15 minutes before being demolished Exposure to water. The surface treated in this way is then noticeably water-repellent.

EXAMPLE 6 An 8% solution of dimethyl diethoxysilane in benzene is applied to one half of a glass plate, and this plate is then heated to 220 ° C. for 10 minutes. The treated part of the glass plate is then hydrophobic, while the untreated part is hydrophilic.

Example A fiberglass tape that has been cleaned and the finish u. Like. Is freed by washing in an ammoniacal acetone and water is immersed in a 2% solution of lauryltrichlorosilane in xylene and exposed to air dried. The tape is then highly water-repellent and cannot be wetted. It's softer, shinier, and has a better grip than it did before removal the finish. Example 8 A fiberglass tape obtained as in Example 7 from the finish is freed, is immersed in a 25% solution of dilauryldichlorosilane in xylene and air dried. The tape is then water-repellent, soft and shiny and has a better grip.

Example 9 A two-strand glass thread weighing 0.16 g has one Breaking strength of 3; 96 kg, when wet of 1.26 kg. Treats the yarn with a 0.5% solution of diethyldichlorosilane in benzene, the breaking strength is 3.92 kg when dry and 3.00 kg when wet, i.e. more than twice as much like the breaking strength of the untreated wet yarn. The electrical surface resistance is 5 megohms per inch for the untreated yarn and 200 for the treated yarn Megaohm. Resistance fluctuations; caused by breathing a sigh of relief on the test object are noticeably reduced after the treatment.

Example io A number of glass rods are made by etching the surface With, hydrofluoric acid carefully prepared to remove bumps from the surface and remove impurities. Some of the rods pretreated in this way are used in a i% solution of octadecyltrichlorosilane in benzene and then dipped for 3 minutes heated to iio ° C. All rods are then one under the same test conditions Subject to abrasion. Then the tensile strength of the rods after known procedure. The average tensile strength of the treated Rods is twice as large as that of the untreated.

What the unusual water-repellent effect of the invention Articles treated with organosilanes cannot be precisely determined. Although it is known that hydrophilic surfaces such. B. surfaces of glass or other siliceous materials, usually a tightly adsorbed film of moisture own. There is a possibility that the hydrolyzable organosilanes through the surface moisture is hydrolyzed and the corresponding silicones or siloxanes, but why the hydrolysis products or the polymers Hydrolysis products are so strongly adsorbed by themselves on the hydrophilic surfaces become, and why these organosilicon compounds in general such surfaces Make it water-repellent has not yet been clarified.

As already stated, the method according to the invention can applied to siliceous materials such as glass, mica, asbestos, alsifilm, etc. will. However, the process can also be applied to non-siliceous materials including Textiles such as cotton, silk, rayon, wool, hemp, flax and the like, application Find; as well as organic: material such as paper, wood, cellophane, regenerated Cellulose, cellulose esters and ethers, vinyl polymers, polyamides, etc.; on plastic Natural or synthetic materials, fabrics and products made from them. According to the invention, the method is advantageously used for treating glass threads during of the manufacturing process to protect them from the harmful effects of moisture to protect and to give them better flexural strength in the wet, a high To impart abrasion and greater electrical surface resistance. Advantageous therefore becomes the method in the manufacture of electrical insulating material that exposed to humid conditions, -related.

As already stated above, when the excess of organosilanes has been washed off by solvents, coatings only have a molecular thickness. In special cases, however, it appears desirable not to wash off the excess of organosilane compounds in order to provide the treated objects with a coating layer that is thicker than a number of molecular starches. This layer then also serves other purposes than just to make the treated object water-repellent. For example, in the continuous production of glass fibers or fabrics, the organic

Claims (1)