DE1546853B2 - Method of applying coatings - Google Patents

Description

A mixture of one part of analytically pure denatured alcohol, one part of a dispersion paint solution formed from 20% polyamide thermoplastic resin and the remainder ethyl alcohol becomes further treatment used. The pretreated end face of the neoprene piece is placed in this solution dipped to form a coating on it.

The coated area is then air dried for about 30 minutes at room temperature, so that a coherent film of hardened polyamide forms on it. This creates a hardened one cross-linked elastomer material with a surface on which a coating made of a compound low molecular weight easily without further physical or chemical intermediate treatment can be applied.

Example II

Equivalent results are achieved with a paint solution in which the components are as follows be changed:

2 parts of ethyl alcohol per 1 part of the prescribed dispersion. The application of the coating is carried out by spraying with commercially available spray devices instead of by immersion.

Example III

Equivalent results with an evenly distributed coating are obtained by using the Process steps according to Example I and II and subsequent heating of the coated piece for about 30 minutes in an oven at around 170 ° C.

The coating materials used in the method according to the invention are Low molecular weight resins which can undergo crosslinking reactions; these connections must have physical (hydrogen) or chemical bonds with hydrogen atoms on a Can enter substrate area. Such compounds are synthetic resins such as epoxies, polyurethanes and polysulfides.

Such resins adhere firmly to the thermoplastic film applied according to the invention without Pretreatments are required. Therefore, the thermoplastic films can advantageously be used in place of the hitherto customary bonded, thermosetting and crosslinked materials can be used. It surrendered It is therefore suitable for many electrical applications in which the electrical and mechanical properties of the cured elastomers should be used without restriction, many advantages.

The method according to the invention makes it possible to produce thermosetting and crosslinked elastomers to use. It is possible to manufacture workpieces from these materials with the property to be coated in a suitable manner with the coating resins described. This has the Advantage that large numbers of items are manufactured, stored and later delivered and processed can.

Claims (3)

1 - 2 v- which are used in the named bindings Patent claims: to hardened elastomer materials. Although these are difficult to bind, they are subject to 1. Method of applying coatings easily subject to "free radical attack". In this home Resins with a low molecular weight, which is referred to as "attack by free radicals" before crosslinking reactions can enter into the product of reactions such as oxidation or Cured elastomers understood by the action of free halogenation. Known elastomers, Radicals on the elastomer forming and which can be treated in this way, resistant, reactive areas, which means that natural rubber, cis-isoprene rubber, styrene are identified, that immediately after the io butadiene copolymers, cis-butadiene polymers, Buna formation the reactive areas and before the rubber, polychloroprene and ethylene-propylene application of the coating is the surface of the EIa copolymer and terpolymers. stomer with a film of polyamide, poly- So far, reaction points were on the surface urethane or a vinyl copolymer with crosslinked elastomers immediately before polymerizable unsaturated acids or 15 compounds through the use of strongly oxidizing Vinyl pyridine is coated. the or halogenating substances created, which 2. The method according to claim 1, characterized in the chemical composition of the surface, that as the material for the coating. This method of training links Surfaces that can be used with epoxy, polyurethane or polysulphide have the disadvantage that they become effective. 20 is quickly canceled. The short Le- 3. The method according to claim 1 or 2, characterized in that the reaction sites thus formed will last characterized in that as an elastomer natural declared that the modified structure is in the Rubber, cis-isoprene rubber, a styrene-butadiene original state and / or that Copolymer, a cis-butadiene polymer, the newly formed structural components through partial polychloroprene or an ethylene-propylene 25 would take part in further reactions, d. H. further Vernet mixed polymer is used. tongue, get lost. This disadvantage is ". According to the invention eliminated by a method for applying coatings from low molecular weight resins, which 30 crosslinking reactions can enter into hardened Elastomers due to the action of free radicals The invention relates to a method for applying to the elastomer with the formation of inconsistent rain of coatings made of resins with low molar active sites, which consists in that unkular weight, which crosslinking reactions take place immediately after the formation of the reactive parts can be applied to hardened elastomers by applying the surface and before applying the coating Free radicals on the elastomer under surface of the elastomer with a film of poly formation unstable reactive sites, amide, polyurethane or a vinyl copolymer Many areas are known in electrical engineering, with or polymerizable unsaturated acids in which it is necessary to use curable compounds that are coated with vinyl pyridine. such as epoxy resin with the surface 40. The film firmly applied in this way is of a hardened cross-linked elastomer, as in the case of the surface for firm application without any intervening Neoprene to join. The compound treatment of the resin coating of low molthis Materials is difficult and has heretofore been used by weight. achieved by a chemical treatment, the following are exemplary embodiments of the Surface of the cured elastomer activated 45 invention described .., ... .... is used in order to facilitate the formation of "binding sites" possible. Example I. Bonds between two materials can be physical ("hydrogen bonds") or the flat end face of a cylindrical neoprene chemical Be nature. It is difficult to make such a binding 5 ° piece with a diameter of 2.54 cm fertilize between materials, of which 15 seconds in a bath of pure commercial his has crosslinked structure because the surface is dipped in ordinary acetone to clean it and of, networked. Materials., No reaction or defatting. The part is then Has "binding" posts which are required, air-dried at temperature. around solid hydrogen bonds or chemical bonds to create fertilizer. The meaning of "reaction" for about three minutes in an "activating" solution put «in this context is below from four parts of an aqueous solution of 5.25% still explained. The known hydrogen-concentrated, analytically pure hydrochloric acid In the context of the invention, bond means immersed in 100 parts of water. The »activating« Concatenation of hydrogen atoms in the solution to be applied is in a flat glass container low connection and of strongly electronegative about 0.125 cm high, with the neoprene piece with Atoms such as chlorine, nitrogen or oxygen in its end face on the bottom of the vessel on-surface the other material; chemical bond. fertilize, on the other hand, arise from the division of After removing from the "activating" Electrons between two atoms and / or through 65 solution become the end face and the adjacent ones Connection formation. In certain cases, the areas are washed thoroughly with clear water comfortably both forms of attachment exist. and with compressed air from a normal laboratory air source In general, it concerns with crosslinked substrates, dried quickly.