DE1167706B - Process for the production of coatings containing a silicone resin, which prevent sticking or sticking, on objects made of glass, porcelain, earthenware and enamel - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: B44d

German KL: 75 c -5/08

Number: 1167 706

File number: U 5682 VIb / 75 c

Filing date: October 17, 1958

Opening day: April 9, 1964

It is known that silicone varnishes are used for applying a non-adhesive coating to bread molds and wafer molds etc. used for the purpose of facilitating removal from the molds and sticking on to prevent the shape. The use of these varnishes to treat aluminum appliances has heretofore been did not deliver good results. The layer deposited on the metal turns out to be proportionate soft, even after prolonged curing. Therefore, such a coating wears out quickly. On the other hand, the anti-sticking effect of silicones on certain foods is also possible to be desired.

It is also known that polytetrafluoroethylene (trade name "Teflon") on aluminum devices is applied to prevent the food from sticking. The one deposited on the metal Layer is harder than that obtained with silicone varnishes. However, it is difficult to apply a layer which adheres completely to the metal due to the anti-ao adhesive property of the polytetrafluoroethylene. Previous and complex treatments of the metal or Polytetrafiuoräthylens must be be applied.

It has now been found that the combined use of silicones and polytetrafluoroethylene enables non-metallic surfaces with anti-adhesive To cover layers, which still adhere completely. The inventive method for the production of sticking or sticking preventing containing a silicone resin Coatings on objects made of glass, porcelain, earthenware and enamel is characterized in that several silicone resin coatings with an addition of polytetrafluoroethylene and possibly pigments are applied, the content of silicone resin with increasing distance from the surface of the object decreases.

The silicones ensure that the coatings adhere to the surface, while the polytetrafluoroethylene the hardness is increased and the anti-adhesive property to substances such as sugar, gelatine, Carpentry glue, sodium silicate, cement, acrylic resins, polyesters, rubber and the like improved.

The hardness of the layers produced in this way is superior to that of aluminum. It is 7 H to 8 H after the scale of Wi 1 k i η s ο η (pencil scale), whereby the hardness of the aluminum is about 3 H to 4 H on this Scale is.

The method according to the invention can be implemented in various ways. The number of layers applied is variable; in the process for producing sticking or sticking-preventing, a silicone resin
containing coatings on objects
Glass, porcelain, earthenware and enamel

Applicant:

UCB (Union Chimique-Chemische Bedrijven)

SA, Saint-Gilles-lez-Bruxelles (Belgium)

Representative:

Dr.-Ing. A. van der Werth,

Hamburg-Harburg, Wilstorfer Str. 32,

and Dr. F. Lederer, Munich 8, patent attorneys

Named as inventor:

Abraam Gancberg, Forest (Belgium)

Claimed priority:

Belgium October 18, 1957 (561714)

generally one to ten. You can start with the application of an emulsion, which is active Contains 50% silicones and 50% polytetrafluoroethylene, and ends with an emulsion with 25% Silicone and 75% polytetrafluoroethylene, or even 5% silicone and 95% polytetrafluoroethylene, or with Polytetrafluoroethylene alone. Obviously the combinations can be changed in countless ways.

You can also add pigments to the emulsions and thus get the treated surfaces with a colored non-stick coating. These pigments are used in any of the on the Surface applied emulsions incorporated. This pigmented emulsion is produced after any known manner.

All pigments are basically suitable, but they have to be those which the emulsions do not break. The choice depends primarily on the desired effect of the jewelry. One preferably uses metallic powders, e.g. B. of aluminum, zinc and bronze, or powder of iron, chrome and Titanium oxides, chromates, for example zinc chromate, sulfides, sulfates, ultramarine blue, etc. Of course All of these pigments must have a distribution state that the granules in Suspension remain in the mixture of emulsions. For numerous applications, these Pigments also have good heat resistance.

409 558/361

For the production of the emulsion one uses methyl-, phenyl- and methylphenylsilicone with one R: Si ratio below 1.8.

The agents applied according to the invention are produced, for example, as follows.

One begins by making a silicone emulsion by turning water into an emulsifying agent containing silicone varnish adds. The polytetrafluoroethylene emulsion is then used, and optionally Pigments added. Finally, the concentration is set, which is 150 to 350 g of the binder per liter.

Of course, the production of the agents does not belong to the invention and they can be made according to known methods Process are produced.

In the following examples are the compositions of the emulsions expressed as a percentage of the binders. . .

Example 1

An enamelled pan is cleaned with sand, washed and dried. A mixture of an aqueous emulsion of a methylphenyl silicone resin (CH ₃ + C ₆ H ₅ : Si = 1.6) and a polytetrafluoroethylene emulsion is placed on the pan. The mixture contains equal amounts of each binder by weight. The pan is dried by the action of infrared rays and then heated rapidly to 380 ° C. in order to agglomerate the polytetrafluoroethylene particles. Then bringing an emulsion layer with a content of 10 ⁰ / o of the same silicone resin and 90% polytetrafluoroethylene. It is dried and polymerized in the heat as just described. Scrambled eggs are poured into the pan that has been treated in this way, without adding any fatty substances, left to roast over a low fire and then the omelette, which does not stick to the pan, can easily be removed.

Example 2

The cuts of a flask and a cooler made of Pyrex glass are carefully washed and dried. A thin layer of hydrofluoric acid with 30% HF is applied to the ground, which quickly evaporates in the air. It is then treated with an aqueous emulsion which contains 25% of a phenyl silicone resin (C ₆ H ₅ : Si = 1.6) and 75% of polytetrafluoroethylene. After drying in hot air or with infrared rays heating the cut bodies rapidly to 38O ⁰ C, so as to agglomerate the Polytetrafluoräthylenteilchen.

An emulsion containing 5% of the same silicone resin is applied to the first layer 95% polytetrafluoroethylene. Dry and sinter in the heat as just described. One gives between these grinding points caustic soda of 30% and let stand for 48 hours. The dismantling grinding is easy, and no caking of the ground surfaces can be seen.

Example 3

The chick of an earthenware faucet is mechanically depolished with an abrasive, washed and dried and treated with methyltrichlorosilane, which hydrolyzes in humid air. Man dries the treated surface with a rag and successively applies:

a) an emulsion with a content of 60% methylphenyl silicone (CH ₃ + C ₆ H ₅ : Si = 1.5) and 40% polytetrafluoroethylene;

b) an emulsion with a content of 30% methylphenyl silicone (CH ₃ + C ₆ H ₅ : Si = 1.5) and 70% polytetrafluoroethylene;

c) an emulsion with a content of 10% methylphenyl silicone (CH ₃ + C ₆ H ₅ : Si = 1.5) and 90% polytetrafluoroethylene.

At each of these plots by drying and sintering connects at 38O ⁰ C.

This tap is placed in a bypass line for benzoyl chloride brought. After use, the tap is not stuck. In contrast, there is such a person Hahn stuck very quickly if he wasn't using a silicone-polytetrafluoroethylene mixture is treated.

Example 4

The cuts of a faucet made of Pyrex glass are degreased, washed and dried. Man treated they with methyltrichlorosilane, which hydrolyzes rapidly in air. Rinse with water and then dry.

An emulsion with a content of 5% of a methylphenyl silicone resin (^ - = 1.5; CH ₃ + C ₆ H ₅ : Si = 1.4) and 95% of polytetrafluoroethylene is applied to the cuts.

The mixture is gradually heated until fluorine is evolved from the polytetrafluoroethylene.

It is allowed to cool, caustic soda is introduced into the joint and the whole thing is left for 24 hours himself. The next day you find that the tap turns slightly.

Example 5

A Pyrex glass container is depolished by the action of hydrofluoric acid vapors, washed and dried and then treats it with methyltrichlorosilane, which hydrolyzes in air. One brings to the Container an aqueous emulsion with a solid content of 45% methylphenyl silicone

₃ + C _e H ₅ : Si = 1.5),

10% chromium oxide and 45% polytetrafluoroethylene. The container is dried with infrared rays, then it is heated rapidly to 380 ^° C. in order to agglomerate the polytetrafluoroethylene particles. Then applies an emulsion layer containing 10% of the same silicone resin and 90% polytetrafluoroethylene. Dry and sinter in the heat as just described. The container thus treated has a beautiful appearance.

Milk is boiled in this container. The milk does not stick to the glass, even if you use it can easily burn.

Claims (1)

Claim: Method of manufacturing a sticking or sticking-preventing silicone resin containing coatings on objects made of glass, porcelain, earthenware and enamel, thereby characterized in that several silicone resin coatings with an addition of polytetrafluoroethylene and optionally pigments are applied, the content of silicone resin with increasing Distance from the surface of the object decreases. Considered publications:
U.S. Patent No. 2,644,802. 409 558/361 3.64 © Bundesdruckerei Berlin