EP1593775B1 - Water-vapour permeable, fungal resistant coated fabric - Google Patents

Abstract

Production of water vapor-permeable, fungus-resistant coated fabrics (A) involves: (i) impregnating a pre-cleaned fabric with an aqueous composition containing an antifungal agent and a hydrophobizing agent; (ii) drying; (iii) coating with an aqueous polyurethane dispersion, also containing an antifungal agent and optionally other additives (e.g. coloring pigments); (iv) drying; (v) post-impregnating with an aqueous hydrophobizing composition; and (vi) drying. An independent claim is included for the coated fabrics (A) obtained by the process.

Description

The invention relates to coated, water vapor permeable and fungus resistant fabrics, in particular technical fabrics, a process for producing the same and their use for the production of sunscreen and weather protection articles such as tent fabrics, boat covers and the like.

Water-vapor permeable, textile fabrics are known in particular from the fields of application of functional sportswear and protective clothing as well as various medical fields. Common processes for the preparation of water vapor-permeable textiles from the above-mentioned areas are known in particular under the names "Goretex" and "Sympatex", which work on the principle of the production of microporous structures.

Waterproof but moisture-permeable coated textile fabrics and methods for their production are also in the DE 2948892 C2 described. The processes described therein work by using a polyurethane solution in an organic solvent and then prepare the microporous polyurethane layer by the coagulation process.

Other processes for the production of polyurethane-coated fabrics which are breathable and water repellent, z. B. in the DE 3633874 C2 described. The process described in this patent uses two aqueous polyurethane dispersions, which are wet-wet after each other.

In the DE 44 22 140 A1 For example, a tent fabric, in particular for the military sector, which has a coating composition on at least one side, is described. This tent fabric is made of a flame retardant yarn, and the coating composition may also contain a flame retardant. Indications that this coating, which may be applied to a pre-impregnation layer and to which a Nachimprägnierungsschicht can be applied, does not contain this document.

The water pressure resistances obtained according to the teaching of this German patent application are at a water column of 500 mm. Notes to obtain such a high water pressure resistance, as it is possible according to the invention are not found in this German application.

US-A-2001021616 describes a process for the preparation of a coated, water-vapor-permeable, oil, dirt and water repellent, fungus-resistant fabric, which fabric is first treated, then impregnated with an aqueous impregnating agent containing a fungicidal and a hydrophobing agent, dried and treated with an aqueous dispersion of a hydrophilic polyurethane, hydrophobing agent and fungicide is coated. To improve the water properties, the coating can be repeated. A high amount of water repellent is used.

However, it has been found that the degree of water vapor permeability is not satisfactory in all cases. In addition, very often form in the pores of the coatings condensates. This brings as a disadvantage u. a. that mushrooms form in these condensates. It is also unavoidable that mushrooms spread even in the rooms that are supposed to be protected by the coated fabric. Thus, on the inventory of the interiors of ships such as yachts and the like unsightly matte deposits that give the objects located in the interior an ugly appearance.

Also, it often happens when such coated textiles serve as a cover for ships and dents form in the covers, where water can collect, that over time, the water pressure on the coated textile is so great that even water in liquid Form penetrates through the coated fabric and enters the interior to be protected.

Although there are already a number of water-vapor-permeable polyurethane-coated fabrics, there is still a need for improved such coated fabrics as well as simple processes for their preparation and in particular for coated fabrics, which are particularly advantageous for the production of sunscreen and weather protection products.

The object of the invention is to provide a method for producing such coated fabrics available, which are characterized by good water vapor permeability and good water pressure resistance, which also have improved fungal protection properties, oil, dirt and water repellent and are also weather resistant beyond ,

This object is achieved by a process for the production of coated, water vapor permeable and fungus resistant fabrics according to the teaching of claim 1, which is: Process for the preparation of coated, water vapor permeable and fungus resistant fabrics with a water vapor permeability of 800 to 2800 g / m ² x 24 h and a water pressure resistance of a water column of 800 to 1800 mm, characterized in that one impregnates a pre-cleaned fabric with an aqueous impregnating agent containing 1-5 wt .-% antifungal agent and 0.2-2 wt .-% water repellent, dries , Then with an aqueous dispersion of a hydrophilic polyurethane, which is also a fungicidal and optionally further additives such. As containing coloring pigments, coated, dried and then re-impregnated with an aqueous hydrophobing agent and drying wherein the hydrophilic polyurethane is applied in an amount that the fabric has a coating coverage between 30 and 50g / m ² dry substance polyurethane.

Preferably, the aqueous impregnating agent contains 2-4% by weight of antifungal agent. It is advantageous if the aqueous impregnating agent preferably contains from 0.4 to 1% by weight of a hydrophobing agent.

It is also advantageous if the impregnated and dried fabric is coated at least once with an aqueous polyurethane dispersion.

It is also advantageous to carry out the impregnation by the padding method or spray application method.

Another object of the invention are coated water vapor permeable and fungus resistant fabric, prepared by one of the methods given above.

The fabrics according to the invention have a water vapor permeability of 800 to 2,800 g / m ² x 24 h in a temperature range of 20 - 50 ° C. and a water pressure resistance of a water column of 800 to 1,800 mm.

The process according to the invention can be carried out as follows.

First, a fabric is produced in a manner known per se. The fabrics are in particular so-called technical fabrics, which are distinguished from purely textile fabrics by a higher basis weight and higher tensile strength. Suitably, the basis weight of the fabrics is in the range of 150 to 450 g / m ² .

The tissue is then cleaned z. Example by washing the raw tissue by means of a jigger or Continuewaschverfahrensverfahren, in particular the residual substance such as spin finish and the like are removed.

The thus washed and dried fabric is then impregnated with an aqueous impregnating agent. This impregnating agent contains one or more antifungal agents and one or more water repellents. The fabric is then impregnated in a manner, i. H. so thoroughly that the fibers or yarns are completely covered with the impregnating agent. This is necessary in order to obtain a full-surface coating in the subsequent coating process.

After impregnation, the fabric thus impregnated is dried. The antifungal agent is generally contained in an amount of 20-40 g, preferably 30 g, per liter of water in the impregnating agent. Furthermore, the impregnating agent contains a water repellent in an amount of, for example, 4 - 10 g, in particular 7 g per liter of water.

After impregnation, the thus impregnated and dried fabric is coated. For coating serve aqueous dispersions of hydrophilic polyurethanes. The aqueous dispersion should contain so much polyurethane that a sufficient amount of polyurethane is applied to the fabric. Advantageously, the amount is so dimensioned that the fabric contains between 30 and 50 g of coating coating per square meter of surface, these quantities being based on dry-substance polyurethane.

The aqueous coating composition further contains a fungicidal agent, preferably the same, possibly also a similar or similar antifungal agent, as used in the impregnation. The coating composition may further contain conventional additives, such as. B. coloring pigments.

When a sufficient and uniform coating has been applied to the fabric, it is dried, and then the fabric is subjected to further impregnation using an aqueous system containing a hydrophobing agent, preferably 3 to 5 g per 100 g of aqueous composition. Through this Nachimprägnierung an improvement in oil, water and soil repellency is achieved.

The thus coated fabrics are characterized in particular by good water vapor permeability, high water pressure resistance, by good oil dirt and water repellency, as well as by an excellent fungus resistance. These functional properties are retained throughout the entire service life, so that even the protected interior is protected from moisture and fungal infestation.

The thus coated fabrics can be used in an excellent manner according to the invention for sunscreen and weather protection items. Tent fabrics, tent roofs, marquee fabrics, boat covers, boat winter coverings, boat summer coverings, splashback covers are especially worth mentioning Boat area, bow windows on boats, especially in such fabrics, the rooms z. B. cabins, boat huts to protect against moisture and fungus formation.

As base substrates, i. H. Yarns for the fabrics may be polyester, in particular polyethylene terephthalate threads or fibers, e.g. As filament yarns, continuous fibers or staple fiber yarns, fibers of polyacrylic, cotton and mixtures of synthetic and natural fibers or man-made fibers such as cellulosic fibers are used.

As further additives in the impregnation or coating can be used conventional additives, eg. B. coloring pigments.

The invention is explained in more detail by the following example:

example

As the base fabric to be refined, in this embodiment, an acrylic fabric having a basis weight of 300 g / m ^{2 was} used, this fabric being made of spun-dyed staple fiber yarns.

In a first process step, a washing process for the substrate, wherein removal of residual substances such as spin finishes is effected by this washing of the raw fabric by means of a jigger or Continuewaschverfahrens.

The following step consists in a pre-impregnation, which on the one hand ensures that in the subsequent coating process, the coating agent film can be applied over the entire surface, on the other hand, the fungicide is well distributed in the tissue.

In this pre-impregnation, the antifungal agent is contained in an amount of 20 to 40 g - preferably 30 g - per liter of water and a water repellent in an amount of 4 to 10 g - for example 7 g - per liter of water.

The hydrophobizing agent causes the coating agent to be applied in a film-like manner to the surface of the fabric in the following step.

In the subsequent coating process, the full-surface application of a water-vapor-permeable polyurethane - namely a hydrophilic aliphatic polyurethane (or a mixture of this polyurethane with another polyurethane) in the form of an aqueous dispersion in a single-coat process, wherein the applied to the fabric amount between 30 and 50 g / m ² - preferably 40 g / m ² - is.

This amount is to be understood as the amount of solids which is contained in dissolved form in an aqueous solution of 100 g total weight, which is used per m ² of tissue to be coated.

In addition, in the coating composition - ie in the aqueous dispersion - the similar fungicides in a concentration of 3 to 5% - in this example 4% - ie 4 g in 100 g aqueous dispersion.

Finally, the product thus coated is subjected to a Nachimprägnierung by a conventional Foulardierungsverfahren, again the water repellents is contained in an amount of 4 g of 100 g of aqueous solution, whereby the textile end product in addition sufficient oil, water and soil repellency is achieved.

Claims (11)

1. Process for producing coated, water-vapour-pervious and fungus-resistant wovens, having a water-vapour transmission rate of 800 to 2800 g/m² x 24 h and a water pressure resistance of 800-1800 mm hydrohead, characterized in that a precleaned woven is impregnated with an aqueous impregnant comprising 1 to 5 weight percent of a fungicide and 0.2 weight percent to 2 weight percent of a hydrophobicizer such a way that the fibers and yarns are fully enveloped by the impregnant, dried, subsequently coated with an aqeous dispersion of a hydrophilic polyurethane which comprises as well a fungicide and optionally further additives such as colour pigments, dried and subsequently reimpregnated with an aqueous hydrophobicizer and dried, whereby the hydrophilic polyurethane is applied in an amount such that the woven comprises a coating add on per square meter of area between 30 and 50 g dry substance polyurethane.
2. Process according to claim 1, characterized in that the aqueous impregnant comprises 2-4 weight percent fungicide.
3. Process according to claim 1 or 2, characterized in that the aqueous impregnant comprises 0,4-1 weight percent of a hydrophobicizer.
4. Process according to one or more of claims 1 to 3, characterized in that the precleaned woven is at least once subjected to the impregnating step and dried.
5. Process according to one or more of claims 1 to 4, characterized in that the impregnated and dried woven is at least once coated with an aqueous polyurethane dispersion.
6. Process according to one or more of claims 1 to 5, characterized in that the impregnating is effected by pad-mangling or by spraying.
7. Process according to one or more of claims 1 to 6 characterized in that the coating is effected by knife coating, preferably by air knife coating or by knife over roll coating or Magno roller knife coating.
8. Coated, water-vapour-pervious and fungus-resistant wovens produced by a process according to one or more of claims 1 to 7.
9. Use of the coated, water-vapour-pervious and fungus resistant wovens according to claim 8 for producing sun and weather protection articles.
10. Use according to claim 9 for producing boat covers, boat winter storage covers, boat summer covers and also sprayhoods in the boat sector.
11. Use according to claim 9 for producing tent materials