DE1177036B - Method for stiffening shoe parts - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: A 43 b

German class: 71 a -23/16

Number: 1 177 036

File number: F 22919 VH a / 71 a

Filing date: April 27, 1957

Opening day: August 27, 1964

The invention relates to a method for stiffening shoe parts, in particular toe caps. For this purpose, both woven and non-woven fabrics have been used, which were previously preferred with a stiffening agent, such as. B. celluloid, synthetic resins, aminoplasts, etc., impregnated.

Such toe caps have various disadvantages. So z. B. Fabric front caps are only ever inserted into the shoe diagonally to the warp and weft directions. Only then does the toe cap exist the necessary "pull" during the subsequent entanglement. Another disadvantage is that In the case of light upper leathers, the warp and weft threads of the inlaid fabric front caps on the upper side sign off. To eliminate these disadvantages, it has already been proposed to use nonwovens with known impregnating agents, like celluloid etc. to impregnate. However, such toe caps are extremely flammable.

It has also already been proposed to use both woven and non-woven fabrics with non-flammable resins, that have not yet fully hardened to be impregnated. This toe cap material must be immersed in an aqueous solution containing a catalyst shortly before use the hardening of the impregnating agent in question is accelerated.

However, such toe caps also have disadvantages. In particular, their storage frequency is limited, because the air in industrial areas often contains acidic and / or basic components, which in turn cause the resin to harden before use.

But even if such resin-impregnated toe caps are used in good time, there are disadvantages because the catalyst applied later initially causes the outer layers to harden.

Now, however, the resin should not only stiffen the toe caps, but also bond them together with the upper leather and the lining.

However, only the outer layers of the resin are available for bonding. However, if the Curing of the resin by the diffusing catalyst takes place from the outer layers, so at the same time the adhesiveness of the latter is reduced.

As a result of these facts, a known method has not prevailed, according to which under among other things, the toe cap material with the catalyst and the upper leather or lining material with the Resin are to be impregnated. When the layers so impregnated are put together, the Kataly process should be used for stiffening shoe parts

Applicant:

Carl Freudenberg, Weinheim (a. D. Bergstrasse)

Named as inventor:
Dr. Wilhelm Lauppe,
Dr. Robert Schabert, Weinheim (ad Bergstrasse)

diffuse from one layer into the resin-impregnated layer, causing it to harden cause. It turns out, however, that the desired effect is achieved only very imperfectly. First of all, catalyst certainly diffuses into the surface of the stiffening agent. Already effected after a short time However, this catalyst causes the upper layer to harden and thus blocks the access of further ones Amount of catalyst for the lower lying, not yet hardened resin layers.

In another process, a fabric or fleece is again impregnated with hardenable resins, which by a catalyst or by the action of heat in the cured final state pass over. However, since such products are too rigid, non-curable resins are mixed with the curable resins Polymers. The uncured resin portions of such toe caps are at a temperature however, run out above 30 ° C. So resin penetrates through and often gives the upper leather a stained appearance.

It has now been found that the disadvantages of the known toe caps can be eliminated by that a latex-bonded nonwoven fabric is first treated with a catalyst, e.g. B. a zinc chloride solution impregnated, and only shortly before inserting into the shaft and shaping on the last with and / or intermediate condensates of such plastics re-impregnated, which under the action of the catalyst pass into the solid end state at room temperature, e.g. B. with prefix and resp. or intermediate condensates among aminoplasts and / or thermoplastics.

In this mode of operation, the catalyst diffuses from the inside (out of the nonwoven layer) to the outside. It the adhesive effect of the outer layer is thus initially retained. This is important as we know the adhesive effect must be used

j.,. . ·, -, -. ··.,, .-. J, 409658/159

to firmly connect the toe caps with the upper leather and the lining. Only after this gluing has occurred, the catalyst diffuses into the outer layer of the resin and hardens this too off, which makes the toe caps inert to the effects of heat, etc. You can also use the methods according to the invention vary the amount of resin to be applied in the toe cap.

This fact is not insignificant because there is a front or back cap - depending on which shoes it is to be used in - have a more or less stiffening effect target.

However, if the shoe manufacturer is supplied with a material with a certain amount of resin, then it is such a variation is not possible. In this case, the shoe manufacturer must have different types of toe caps in stock so that you can find the right caps when you need them. He will then immerse this in the catalyst solution.

Since an impregnation must be carried out in any case, it seems more appropriate to use the Shoe manufacturer to deliver a catalyst-containing nonwoven fabric, which is only used shortly before use Resin is impregnated.

It turns out that the best results are achieved if one impregnated with latex as a carrier material Non-woven fabric used. The latter is isoelastic, so it has the same elasticity in every direction on. Wrong insertion as with a woven toe cap is therefore not possible.

In addition, since the absorption capacity of a latex-bonded nonwoven fabric is very high, very large amounts of resin can also be stored. The production of a latex-bonded nonwoven fabric is known; she can z. B. can be taken from German Patent 211.

Claims (1)

Claim: Method for stiffening shoe parts, in particular toe caps, by means of one of a latex-bonded nonwoven insert, characterized in that such a Nonwoven fabric with a catalyst, e.g. B. zinc chloride solution, pre-impregnated and just before the insertion in the shaft and the molding on the last with pre-and or or Intermediate condensates of such plastics is re-impregnated under the action of the catalyst pass into the solid end state at room temperature, e.g. B. with before and or or intermediate condensates of aminoplasts and / or phenolic plastics. Considered publications: German Patent Nos. 839 460, 849 237; German patent application G 6833 IVd / 81 (announced on April 22, 1954); Swiss Patent No. 229 408; French patents No. 1 000 251,
672, 1118 896; U.S. Patents Nos. 2,277,941, 2,298,274,
424 869. 409 658/159 8.64 O Bundesdruckerei Berlin