FI56503C - SAETT OCH MEDEL FOER ATT FOERSE ETT UNDERLAG MED ETT FASTLIMMAT ELLER VULKAT ELASTTSKIKT - Google Patents

Description

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Patents Registry Board (44) Nihtlvikslpanon Ja kuLLulkalsun pvm. -

Patent · och registerstyrelsen Ansökan utlagd och utUkrlften publlcerad 31.10.79 (32) (33) (31) Privilege claimed —Begird prlorltet 12.03.71 2U.02.72 Sweden-Sweden (SE) 3183/71, 2268/72 Toteennäytetty-Styrkt (71) ) Trelleborgs Guromifabriks Aktiebolag, Nygatan 102, 231 00 Trelleborg,

Sweden-Sverige (SE) (72) Bo Klas Gerhard Persson, Trelleborg, Sweden-Sverige (SE) (7U) Leitzinger Oy (5 ^) Method and spacer for fitting a chassis with a glued or vulcanized elastic layer - Sätt och medel för att förse that the underlag with the fastest or volcanoes elastic

When gluing and curing already vulcanized elastic materials, such as natural rubber and ethylene propylene rubber, it is often necessary not only to clean and degrease the surface to be glued or vulcanized, but also to roughen the surface to form fresh, raw surface parts. This roughening is necessary especially if the vulcanized elastic material has been kept in stock before it is glued or vulcanized to the substrate. Only such roughening and the formation of fresh raw surfaces will achieve the required conditions for the adhesive or vulcanization joint to become sufficiently strong.

Such roughening of the flexible surface is currently carried out, for example, by means of steel brushes, sandpaper or the like. However, attempts have also been made to provide a fresh surface for gluing by using special gluing layers when vulcanizing the product.

However, such mechanically freshened or roughened surfaces and such special adhesive layers have a limited storage time because of the migration of chemicals from the interior of the flexible layer to the surface layer. This migration of chemicals occurs regardless of whether the surface is exposed to ambient air 56603 or whether it is covered with a conventional cover layer of silicone-coated label paper. If it is desired to produce vulcanized resilient layers as a stacked product for bonding or gluing to a substrate, or if it is necessary to produce vulcanized resilient layers for transport to the customer as a special order, it is thus necessary for the user to freshen However, this necessary roughening is time consuming and requires special work steps. The object of the present invention is therefore to provide a simpler way of providing the substrate with an elastic layer, in which way rapid preparation of the surface to be glued or vulcanized to the substrate is possible without special roughening machines.

The present invention relates to a method of providing a substrate with a vulcanized elastic layer, in which a vulcanized separate elastic layer is prepared and the surface of the elastic layer for gluing or vulcanization with the substrate is prepared for gluing or vulcanization, and then the elastic layer is glued or vulcanized. with a binder which can optionally be cured or vulcanized. The method according to the invention is characterized in that the preparation of the surface to be glued or vulcanized of the separate vulcanized elastic layer takes place by placing or applying on the surface only a tissue, fibrous or foil layer inspired superficially with the elastic material, and that in connection with gluing or vulcanizing the elastic layer to the substrate, this fabric, fibrous or foil layer is pulled away from the separate elastic layer by tearing said superficial elastic material at least in part from the surface to be glued or vulcanized so that fresh elastic material is released from at least these parts. Preferably, the fabric, preferably sparse fabric, is vulcanized to the surface of the discrete vulcanized elastic layer so that the elastic material in the discrete elastic layer penetrates through or at least into the fabric, and the elastic material extending through or into the fabric will rupture upon withdrawal. This results in evenly distributed, point-like surface portions of the fresh elastic material in which no chemical enrichment has occurred which is detrimental to the strength of the joint.

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As a fabric, fibrous or foil layer applied inside or on the surface of the vulcanized elastic layer, for example, cord yarn fabric can be used, but a fibrous gauze of such strength can be used that it can be pulled from the main part of the elastic layer so that the elastic material under the fiber layer comes off. It is also possible to use foils which, when fastened, can be so firmly adhered to the elastic layer that, when the foil is torn off, it takes away the parts on the surface of the inner elastic layer. Such foils include polyvinyl chloride foils.

As a specific and particularly useful example of a fabric, fibrous or foil layer adhered to the surface of the elastic layer, mention may be made of a relatively sparsely woven sail-type cotton fabric, and only a slightly twisted or preferably non-twisted nylon or other synthetic nonwoven fabric material.

The invention also relates to a spacer for applying the above-mentioned method, which spacer consists of a vulcanized, separate flexible layer for gluing or vulcanizing to a substrate, on the surface or surface of which the gluing or vulcanizing surface is applied or applied only superficially with the underlying elastic material, removable fibrous or foil layer.

In this case, the vulcanized separate elastic layer preferably has a sparse fabric arranged on its surface to be glued or vulcanized, because chemicals harmful to the strength of the joint can thus pass through the fabric to its outer side. This will remove all of these harmful chemicals from the tissue.

Examples of elastic materials to which the method according to the invention can be applied are natural and synthetic rubber grades, in particular wear rubber grades, for example natural rubber / styrene-butadiene rubber mixtures and polyisobutadiene / styrene-butadiene rubber mixtures. The invention can also be used for urethane rubber, butyl rubber, etc. rubber grades.

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The invention will be described in more detail below with reference to the accompanying drawing, in which Figure 1 shows on a large scale and in section an example of a vulcanized, separate resilient element having a vulcanized, retractable fabric layer or fabric layer on its adhesive or vulcanizable surface; can be fitted to the surface of a separate vulcanized resilient element in the manufacture of the resilient layer.

Figure 1 thus shows on a large scale a part of a vulcanized, discrete elastic element 10 having an adhesive-retractable fabric layer 14 on the surface to be glued or vulcanized, which, when removed, tears off at least some of the resilient material to be so-glued or rolled. that fresh elastic material is released at least from the area of these surface parts.

Figure 2 is a sectional and fragmentary view of how the calendered unvulcanized elastic layer 16 is positioned relative to the specially formed fabric, fiber or foil layer 18 when inserted into the vulcanization press to vulcanize the layers 16 and 18 together. The layer 18 is in this case provided with a bend 20 stabilized by a weak seam 22. When inserted into the vulcanization press, the bend 20 is turned away from the elastic layer 16 so that this bend does not adhere to the elastic material to a greater extent in the vulcanization. When the elastic layer has been transported to the place of consumption after vulcanization and the elastic layer is to be glued or vulcanized, the bend 20 is cut open and the layer 18 is pulled out in two different pieces, whereby the seam 22 is unwound before being pulled apart or automatically opened in a pull-out. 18 tearing is greatly facilitated.

The invention will now be illustrated by a few practical application examples, which, however, are not intended to limit the scope of the invention, especially since the problem of the invention is mechanical rather than chemical.

Example 1 In this embodiment, the invention is used in connection with the vulcanization of a pre-vulcanized elastic layer to another also pre-vulcanized substrate. An example of such use is in connection with the retreading of the outer tire of a motor vehicle.

The vulcanizable wear rubber mixture based on natural rubber and styrene butadiene rubber is mixed according to the following recipe.

Parts by weight

Mastasticized natural rubber (NR) 85

Styrene butadiene rubber (SBR 1500) 15

Zinc oxide 5

Stearic acid 2.5

Antioxidants phenyl-N-naphthylamine 0.75 phenyl-p-phenylenediamine 0.25

Tree tar 8

Carbon black, CRF-black (i.e. channel replacement black) 50

Sulfur, insoluble 1.45

Oxydiethylbenzothiazolesulfenamide 1.00

The vulcanizable wear rubber mixture mixed in the mixing roller apparatus was calendered into a layer and pressed in a vulcanization press against a cotton fabric of the type of sailcloth dyed with a vat dye shaped according to Fig. 2.

The yarn density of this cotton fabric was 38 warp yarns per 2.45 cm and 30 weft yarns per 2.54 cm, and both the warp and weft yarns had the yarn number tex 50x4 (corresponding to the English cotton yarn number Ne 12/4).

The vulcanization of the wear rubber mixture and the cotton fabric into a vulcanized elastic element about 12 cm thick was performed in a vulcanization press at a temperature of 150 ° for 30 minutes.

After various lengths of time, the tissue was withdrawn, and a standard adhesion test was performed. For this experiment, two pieces of elastic elements released from the tissue were placed twice and a vulcanizable adhesive layer was placed between the two test pieces, and the test pieces were not roughened other than by pulling the tissue out.

Both specimens were 2 cm wide and cured together in o 2 air for about 130 ° C for 1 hour at a pressure of 3.0 kg / cm 3. The composition of the binder used for co-vulcanizing the specimens was as follows: 6 66503

Parts by weight

Smoked sheet rubber RSS 1 100

Zinc oxide 5

Silica 30

Stearin 1

Aging protection N-phenyl-N-isopropyl-p-phenylenediamine 1 Antioxidant phenyl-S-naphthylamine 1 mineral rubber MRX 5

High-aromatic mineral oil 6

Sulfur 2

Carbon black HAF 5 diethylene glycol 3 diphenylguanidine 3 dibenzothiazyl disulfide 2 N-pentamethylene ammonium N-pentamethylenedithiocarbamate 2 This binder is designed for "cold vulcanization" at 85 ° C but was used in adhesion tests at 128 ° C for vulcanization. Upon lamination, both specimens were brushed with a gasoline solution of said binder mixture (10% solids) after tissue removal. The naphtha had a distillation range of 85-110 ° C and a viscosity of 250 cP as measured in a Brookfield viscose meter. The test pieces were then placed together and between them with a bonding rubber layer, after which said vulcanization was carried out at about 130 ° C for one hour.

For comparison, conventional roughening of the test pieces was also performed, which test pieces were of vulcanized wear rubber grade without a vulcanized tissue layer. After this conventional roughening, doubling was performed in the same manner as for the above-mentioned retractable tissue specimens.

The table below shows the results of the adhesion experiments performed as splitting experiments.

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Pulled tissue Normal roughening Splitting force xx Fracturing force Fracturing test time x_kg_point ma xx kg_point immediately 25.1 A - -

After 1 day - - 28.6 A

After 1 week 35.1 B 37.8 A

2 "" - - 34.2 A

3 "" 44.0 A 44.6 A

4 "" - - 40.8 A

5 "" 30.4 B

8 "" 30.6 A - 11 "” 32.3 B - 14 "" 32.7 A - x The time interval between vulcanization and doubling of the wear rubber layer by vulcanizing together with a rubber band xx Force per 2 cm of the width of the test piece A Rubber bond hydrogen sulphide B Tear off the wear rubber.

The results show that the adhesion was essentially the same regardless of whether the roughening was performed by pulling off the fabric according to the invention or by conventional mechanical roughening. However, the great advantage of the method according to the invention is that roughening by pulling the tissue requires only a fraction of the time spent on conventional roughening. When retreading a large motor vehicle tire, this time saving can go up to one or more hours.

Example 2 In this embodiment, the same unvulcanized wear rubber compound as in Example 1 was used, but in this case, a nylon fabric was vulcanized to the surface while vulcanizing the wear rubber compound. The nylon fabric consisted of twisted nylon yarn with a thread number of 940 deci-tex (equivalent to 840 denier) and a twist of 7 turns / 2.54 cm. The fabric had 21 warp yarns at 2.54 cm and 22.5 weft yarns at 2.54 cm. A 4 cm thick wear rubber layer was calendered and placed together with the nylon fabric in a vulcanization press where vulcanization was performed at 8 56503 160 ° C for 30 minutes.

After vulcanization, the vulcanized wear rubber layer was allowed to cool. After 1 day, an adhesion test was performed by splitting partly with respect to the adhesion of the fabric to the wear rubber layer, partly with respect to the adhesion of the wear rubber layer to the metal substrate (steel), after the wear rubber layer fabric was pulled off and the wear rubber layer glued to the metal substrate.

After the fabric was removed, the adhesive was performed by first coating the abrasive rubber layer with a conventional chloroprene primer and then gluing with a conventional chloroprene rubber type adhesive. For comparison, the same gluing was also performed after conventional, mechanical roughening.

The results of the adhesion tests were as follows, whereby tensile means the force required to split the wear rubber from the fabric against a metal substrate using 2.54 cm wide test pieces.

magnetism

Adhesion of the fabric to the abrasive rubber 7-8 kg Adhesion of the abrasive rubber to the metal substrate in conventional roughening approx. 5 kg of fabric when pulling 7-8 kg

Both in the conventional roughening and in the roughening according to the invention, cracks appeared in the adhesive joint.

It will be seen from this embodiment that the adhesion becomes somewhat better when using the invention than when using conventional roughening. In addition, it can be seen that the fabric formed of twisted nylon yarn accumulated strong adhesion to the vulcanized wear rubber layer, which made it somewhat difficult to peel the fabric. A traction of the order of 2.5-3 kg / 2.54 cm would be most preferred.

Example 3

Example 2 was repeated with the difference that the nylon fabric was replaced by a so-called with a flat yarn nylon fabric, namely 9 56503 nylon yarn fabric with a yarn number of 940 deci-tex but no twist, the filaments of the Nylon yarn were thus essentially parallel, resulting in a smaller free loop opening compared to the nylon fabric of Example 2. The yarn density of the nylon fabric used in Example 3 was 21.5 warp yarns per 2.54 cm and 23.0 weft yarns per 2.54 cm.

The adhesion test gave the following results for a 2.54 cm wide specimen.

magnetism

Adhesion of the fabric against abrasive rubber Adhesion of 3 kg of abrasive rubber to the metal substrate by conventional roughening of approx. 5 kg of fabric when pulling out 9-10 kg

Both in the conventional roughening and in the roughening according to the invention, cracks appeared in the adhesive joint.

It can be seen from this example that the nylon fabric formed from the flat yarn gave a better result both in terms of the peelability of the fabric and in the adhesion of the abrasive rubber to the substrate after gluing. It is thus clear that this type of nylon fabric is more advantageous than a fabric made of twisted yarn.

It can be seen from both Example 2 and Example 3 that the method according to the invention resulted in a stronger adhesive joint than the conventional adhesive joint after mechanical roughening.

The method according to the invention is useful not only for retreading motor vehicle tires but also for attaching any pre-vulcanized resilient layer to any type of substrate, including other resilient layers, plastic, metal, wood and concrete, eg by gluing a wear rubber liner to a sheet metal drum.

Claims (6)

A method of providing a substrate with a vulcanized elastic layer, the method comprising: preparing a vulcanized discrete elastic layer (10) and pre-gluing the surface of the elastic layer for gluing or vulcanizing with the substrate and then gluing or vulcanizing the resilient layer with a binder, optionally curable or vulcanizable, characterized in that the surface (12) of the separate vulcanized resilient layer (10) to be glued or vulcanized is prepared in such a way that a separate resilient layer is only placed on or applied to this surface a layer of fabric, fiber or foil (18) to be removed with the elastic material, and that this layer of fabric, fiber or foil is pulled out of a separate layer of elastic during gluing or vulcanization to the substrate of the elastic layer (16); when tearing said superficial elastic material onto at least a part of the surface for gluing or vulcanization, so that the fresh elastic material is released at least from these parts of the surface. A method according to claim 1, characterized in that a sparse fabric is placed on the surface of the separate elastic layer so that the elastic material in the separate elastic layer penetrates through or at least into the fabric, and such that the elastic material extending through or inside the fabric breaks. Method according to Claim 1 or 2, characterized in that a synthetic fiber fabric made of untwisted multifilament yarn is applied to the surface of the separate elastic layer. Spacer for applying the method according to claim 1, characterized in that it consists of a vulcanized, separate flexible layer for gluing or vulcanizing to a substrate, on the surface or surface of which the surface or surface to be glued or vulcanized is placed or applied only superficially below it. a layer of tissue, fiber or foil to be removed with the elastic material (18). 11 565G3 Intermediate piece according to Claim · +, characterized in that the separate elastic layer has a sparse fabric arranged on the surface to be glued or vulcanized. Spacer »according to Claim 4 or 5, characterized in that the separate flexible layer has a synthetic fiber fabric formed of untwisted multifilament yarn arranged on the surface to be glued or vulcanized.