CS261326B1 - Method of leathers and fibrous character-elastic flat materials treatment - Google Patents

Abstract

The solution relates to surface problems treatment of leather in which it is combined with polymeric binders and color pigments using a special preparation that affects making movie editing. To improve them in particular the properties of the coating that by using said formulation, applied under the conditions of the solution, the desired is achieved the degree of coloration of the leather at optimal the thickness of the film editing, which creates basic assumption for high quality and surface finishes.

Description

The invention relates to the problem of the surface treatment of leather, in which a special composition affecting the formation of the treatment film is used in combination with polymeric binders and colored pigments. It is an object of the present invention to improve the coating properties, in particular by providing the composition applied under the conditions of the present invention with the desired degree of dyeing of leather at the optimum film thickness, which constitutes a prerequisite for high quality and appearance characteristics.

The surface treatment of leather, the last part of the complex technological process of converting leather into leather, is one of the main criteria determining their quality and marketability.

It is therefore clear that she has always been and will continue to receive considerable care and attention, which is reflected in particular in the use of a very wide and relatively rapidly changing palette of finishing products. By their purposeful application, the properties of the leather surface can be varied to a wide extent and thus achieve the criteria required for individual types of leather according to their use.

The repair gives the leather the desired color shade, uniformity or, on the contrary, the variety of colors, affects the delicacy of the face drawing, high gloss or matt and the like. In terms of physical properties, the leather treatment must be sufficiently elastic to not crack when the leather is bent sharply or repeatedly bent, such as walking, or at elevated or low temperatures. The repair must have sufficient adhesion to prevent peeling of leather shoes during production or wearing. The repair shall have sufficient strength and resistance to water so that it does not rub and rub either dry or wet. Furthermore, the treatment must be sufficiently warm and light fast to resist ironing at higher temperatures and weather conditions and sunlight. The requirements for the leather coating properties indicate that the range of tanneries for surface treatment is extremely wide. In principle, however, they can be divided into four basic groups according to purpose and use. They are:

1. Colors for leather finishing

2. Basic film-forming binders

3. Binders for final protective layers

4. Special auxiliary products

As stated above, the basic criteria for assessing the quality of a coating treatment are its physical properties, which determine its utility properties. These properties can be ensured in addition to a suitable selection of preparations from the individual basic groups, as well as by their own surface treatment technique, especially the optimum thickness of the applied coating film, which has a direct influence on its bending resistance, adhesion and hence wearing behavior. A disadvantage of the formulations and application techniques used hitherto is that the actual amount of coating depends on the degree of covering of the leather surface, so that the optimum film thickness is often exceeded. This results in a deterioration of the physical properties of the treatment. Another negative accompanying phenomenon is higher labor intensity, consumption of treatment products, higher demand of electric energy for driving machines and thermal energy for drying of higher number of deposits of treatment solutions. There are therefore attempts to regulate the hiding power of dressings. This can basically be achieved in two ways. By varying the quality and quantity of pigments used or by reducing the absorbency of the leather surface. Since the surface of the leather is substantially inhomogeneous and the individual leather differs from one another, or the surface of the leather can be damaged or machined, e.g. To date, special leveling preparations, most often made on the basis of paraffin, have been used for this purpose, but they often impair the adhesion of the surface treatment to the cheek of the leather or reduce the physical properties of the treatment. These deteriorated properties of the treatment are related to the fact that the increased content of pigments or leveling agents disrupts the film integrity of the polymeric binder used, especially when the so-called critical volume concentration is reached, especially since these substances differ significantly from those of polymeric binders. These drawbacks are avoided by the surface treatment process of the invention, wherein a special leveling agent consisting of a mixture of an aqueous dispersion of a wax component, a binder component of the acrylate copolymer, a protective colloid and an oil component produced under the name Egalton and protected is added to the polymer binder and pigments. AO 240 027. Due to its waxy content, Egalton reduces the penetration capability of the dressing and, due to the presence of an acrylic polymer, it maintains the quality of the formed polymer film even at an increased bulk concentration of pigments and leveling waxes. Thus, the addition of leveling agent to the finishing finish increases the film's compatibility even at a significantly increased system opacity. This film compatibility is due to the fact that at constant polymeric binder amounts, the EGALTON leveling agent provides a pigment distribution in the treatment film that corresponds to a condition below a critical volume concentration, although without the use of EGALTON this concentration would be exceeded. While it is not possible to exceed the limit of 15 to 20% by volume pigment concentration without the deterioration of the treatment quality in commonly used treatment solutions, with DGALTON this limit is shifted to 20 to 25%, at the same time significantly increased the level of application. This effect is achieved when the EGALTON leveling agent is dosed in an amount of 20 to 120 g / l of the treatment solution, preferably 60 to 100 g / l, with a dry weight of polymeric binders in the range of 10 to 18%. The surface treatment according to the invention results in the possibility of reducing the number of individual coatings required to cover the leather surface by 10 to 30%, which results in significant savings in chemicals, thermal and electrical energy and increased labor productivity. The accompanying advantages of this coating process according to the invention include the fact that the finished coating film exhibits reduced stickiness at normal and elevated temperature due to the presence of the wax component in the leveling agent, allowing the ironing of the coating to be carried out at temperatures of 70-90 ° C. improve the compatibility and the resulting physical properties of the coating film without sticking the leather when stacked after ironing. In addition, the increased compatibility of the treatment film caused by the addition of EGALTON allows the amount of water usually added to the treatment recipes to be reduced by up to 50%, which speeds up drying between coatings and again positively affects the physical properties and reduces the tackiness of the treatment.

The surface treatment according to the invention can be practiced according to one of the following examples:

Coating Squirt 120 220 100 ALIGN! 60 350 300 430 420

Example 1

Composition of the treatment solution for the surface treatment of the corrected face cowhide, composition in parts by weight:

Casein opaque paint, tinted EGALTON, leveling agent Mixture of polymeric binders Water

Example 2

Usage of EGALTON for surface treatment of full grain leather in white finish:

Coating Squirt A) Casein opaque color white 130 230 Casein opaque color okr 1 - EGALTON 90 70 Mixture of polymeric binders 330 300 Water 449 400 B) Reduced water treatment Casein opaque color white 175 280 Casein opaque color okr 1 - EGALTON 120 100 ALIGN! Mixture of polymeric binders 440 300 Water 264 240

Example 3

Use in surface treatment of full grain leather:

Coat + Spray

Casein opaque colors tinted EGALTON

Mixture of polymeric binders

Waterborne nitroemulsion varnish

Water

220

320

350

Repair solutions are applied by commonly used techniques, ie painting, spraying or pouring, in the case of pouring, the solutions are concentrated to the necessary viscosity by the addition of thickening agents.

Claims (3)

object of the invention Method for treating leather and flexible fiber materials of a fibrous character, characterized in that 20 to 120 g / l of a special leveling agent based on an aqueous dispersion of a wax component, a binder of the character, are added to the mixture of pigments and polymer binders. an acrylate terpolymer and a protective colloid, for example manufactured under the trade name EGALTON, at a dry weight of polymeric binders of 10 to 18%. 2. The process of item 1, wherein to increase the opacity, the pigment pigment volume concentration is increased from the usual 12 to 20% up to 25%, i.e., depending on the dry matter and specific gravity of the pigments, in an amount of 220 to 300 g / l of treatment solution. 3. The method according to items 1 and 2, wherein, in order to increase the compactness and opacity of the film, the addition of water for dilution is reduced by 10 to 60% over commonly used formulations.