FI58607C - FOERFARANDE FOER ATT FAESTA EN VULKANISERAD GUMMIKROPP VID ETT UNDERLAG MEDELST SMAELTLIM - Google Patents

Description

{• 5 ^ 1 fBl Publication publication CÄi; n »7 lBJ“ “UTLACCNINQSSKIUFT S00U7 C Patent granted 10 03 1031 • 2S5 («> Patent rceddelat ^ (S1) iMh? A) ta3 B 29 H 9/10

ENGLISH —FINLAND ¢ 21) PWwrttiWwmi · —N »nei * etoih» f T926UU

(22) Hakmltpllvi — AnaMcnlnfriai 2U.08.T9 (23) AlkupWft — GIM | httfdig 2U.08.T9 (41) Tirilut JulkMol - BMvfc cffwKlIj

Pfttwttl-is Registry Board (44) j. toetMitobun

Patent · och refisterstyralsan '# AmMcm utl «| d och utUkrlfton publicorad 28.11.80 (32) (33) (31) Fyydatty« uoikwM — Boglrd pdoritat (Tl) 0y Nokia Ab, Mikonkatu 15 »00100 Helsinki 10, Finland-Finland ( Pi) (T2) Timo Erkki Tapio Laurila, Tampere, Finland-Finland (FI) (7U) Oy Kolster Ab (5U) Method for attaching a vulcanized rubber body to a substrate by melting - Förfarande for att fasta en vulcaniserad gummi-kropp vid ett underlag medelst smältlim is a method of attaching a vulcanized rubber body to a substrate with a hot melt adhesive, the method comprising providing the rubber body with a hot melt adhesive and heating the hot melt adhesive to bring it into an adhesive state on the substrate.

For attaching a vulcanized rubber body, such as a rubber mat, rubber strip or the like, to a substrate which may be iron, steel, other metal or alloy, glass, concrete, wood and articles thereof, such as plywood, particle board, paper, cardboard, etc., leather, plastic, rubber or other material, various methods are previously known.

Typically, various adhesives are used which are applied either to the halide or to the otherwise treated vulcanized rubber surface. The main disadvantage of such adhesives are solvents which, when evaporated, generate solvent vapors which are harmful to health.

\ ι- ··, · 2 56607

Another way to attach vulcanized rubber to a substrate is to use vulcanizable adhesives or interlayer rubbers. The main disadvantage of such methods is the heating required to vulcanize the adhesive and the pressure required during vulcanization.

There are also self-vulcanizing adhesives which have the disadvantage of slowness, as well as adhesives which act rapidly after thermal activation. The disadvantage of these is the evaporation time of the solvent required before thermal activation.

There are also hot melt adhesives in which the disadvantages of the above-mentioned adhesives are avoided, but which have the disadvantage of poor adhesion to vulcanized rubber.

The object of the present invention is to provide a method which avoids the disadvantages described above and which allows the hot-melt adhesive to adhere well to the vulcanized rubber. This object is achieved by a method according to the invention, characterized in that - a thermoplastic adhesive layer adhering the hot-melt adhesive to the rubber body is applied to the surface to be attached to the unvulcanized rubber body, and - the rubber body and the adhesive layer are vulcanized together so that the adhesive layer

The method according to the invention is based on the idea that the hot melt adhesive is made to adhere to the rubber body by means of a thermoplastic adhesive layer to which the hot melt adhesive readily adheres or is incorporated and which adhesive layer in turn adheres to the rubber body by chemical bonding during vulcanization. Compared to the known methods, the method according to the invention achieves the following advantages: no solvents are required, no vulcanization is required at the application site, gluing is fast, hot-melt adhesive adheres to the rubber.

It is possible to apply a special thermoplastic adhesive layer to the surface of the rubber body to be attached first and an actual hot melt adhesive layer on it, or alternatively to apply a combined adhesive and hot melt adhesive layer to the rubber body surface if the hot melt adhesive is made on a thermoplastic rubber base.

The invention will be explained in more detail below with reference to the accompanying drawing, in which Figure 1 shows a preferred embodiment of the method according to the invention, Figure 2 shows a rubber element prefabricated according to this method, Figure 3 shows another embodiment of the method and Figure 58+ shows a prefabricated rubber element according to this method.

In Figures 1 and 2 of the drawing, reference numeral 1 shows a rubber body of vulcanizable rubber intended to be attached on its lower surface 1a to a substrate 2. Reference numeral 3 shows a thin thermoplastic rubber adhesive film applied to said surface 1a of a rubber body. The rubber body and the film applied to its surface are normally vulcanized in a mold, press, continuous mat, autoclave or the like, whereby the vulcanization chemicals in the rubber mixture provide chemical bonds between the rubber body and the film on their opposing surfaces. The surface of the film 3 located away from the vulcanized rubber body remains thermoplastic. The film is applied to this surface by heating the hot melt adhesive layer h.

The vulcanized rubber element 5 prefabricated as described above can be attached to the substrate 2 anywhere or at any time by heating the hot melt adhesive layer 1 * with a heat gun, heat radiation or any other heat source. The adhesion reaches its strength after the adhesive layer has cooled.

The alternative method shown in Figures 3 and k of the drawing differs from the method described in connection with Figures 1 and 2 only in that a combined adhesive and hot melt adhesive layer 6, such as a hot melt adhesive made of thermoplastic rubber, is applied to the surface 1a of the rubber body. In this case, the hot melt adhesive itself vulcanizes to the rubber body under the action of the rubber contained in the layer when the rubber body is vulcanized after application of the layer. The rubber element 7 thus prepared is attached to the base as described above.

Example 1

A typical rubber compound was made from natural rubber, from which a 2 mm thick sheet 1 was made with a rubber roller. Thermoplastic rubber, which is available in several different grades on the market, was made with a rubber roller, a 0.8 mm thick film 3, which was applied to the rubber sheet surface 1a. These were cured together in a mold for the time required by the rubber compound.

Thus, a vulcanized rubber sheet 5 having a thermoplastic rubber 3 adhered to one surface was obtained. A hot melt adhesive layer J + having a composition of: ethylene vinyl acetate 1 * 0%, coumarone resin 28% and microcrystalline wax 32% was applied to the surface of the thermoplastic rubber. With the adhesive melted, the vulcanized rubber sheet was pressed onto the steel sheet 2 and allowed to cool. The strength of the adhesive joint was tested by the Peel test according to ASTM D 3330 and the adhesion was 250 N / 25 mm.

Example 2 A typical rubber compound was prepared from SBR rubber, which was made into a rubber sheet 1, to which a thermoplastic rubber film 3 was applied. The rubber sheet was then vulcanized. The vulcanized sheet was glued with hot melt adhesive 1 * to the steel sheet 2 and the adhesion was measured by the Peel test according to k 58607 ASTM D 3330. The infection was lk2 N / 25 mm. A second vulcanized rubber sheet made of the same mixture without the adhesive film 3 was glued with the same glue to a similar steel sheet. The measured adhesion was 7 N / 25 mm.

Example 3 An adhesive film 3 of thermoplastic rubber was vulcanized on both sides of a rubber body 1 made of an SBR rubber compound. The rubber piece was glued by melting h 2 between two 1.8 cm steel pieces 2. A force of 385 N / cm was required to pull these pieces apart.

The drawing and the related explanation are only intended to illustrate the idea of the invention. The details of the method according to the invention may vary considerably within the scope of the claims.

Claims (5)

5 S8607 A method of attaching a vulcanized rubber body to a substrate with a hot melt adhesive, the method comprising providing the rubber body (1) with a hot melt adhesive and heating the hot melt adhesive to an adhesive state on the substrate (2), characterized in that a thermoplastic the adhesive layer (3; 6) connecting the hot-melt adhesive to the rubber body, and - that the rubber body (1) and the adhesive layer (3; 6) are vulcanized together so that the adhesive layer is cured to the rubber body. Method according to Claim 1, characterized in that a special thermoplastic adhesive layer (3) is applied to the surface (1a) of the rubber body (1) and that a hot-melt adhesive layer (¾) is applied to the surface of the adhesive layer vulcanized to the rubber body. Method according to Claim 1, characterized in that a thermoplastic adhesive layer (6) containing hot-melt adhesive is applied to the surface (1a) of the rubber body (1). Method according to Claim 2, characterized in that the adhesive layer (3) is a film made of thermoplastic rubber. Method according to Claim 3, characterized in that the adhesive layer (6) is made of thermoplastic rubber mixed with hot-melt adhesive.