DD248157A1 - IMPERMANENT FIBER TREATMENT WITH POLYURETHANES WITH PROPERTY-RESISTANT PORIC PROPORTION - Google Patents

Abstract

The interpenetration compounds according to the invention are composed of nonwovens which have been obtained in a known manner using synthetic, natural or regenerated fibers. Depending on the surface behavior, the fibers forming the nonwoven are completely, partially or not wetted by the preferably porous polyurethane that is contained. The fiber entanglements and fiber intersections are elastically connected by punctiform and sail-shaped lamellas. Due to different polymer contents and different penetration depths in cross sections of the nonwovens, water vapor transport and storage capacity, softness and mechanical strengths of the interpenetration compound can be varied within wide limits. The resulting products are to be processed for a wide range of applications of the clothing industry, footwear industry, furniture industry and other specialties with advantages.

Description

Field of application of the invention

The invention relates to a penetration composite of nonwoven fabric and an elastic polyurethane (PUR), which u.a. characterized by almost isotropic strength behavior of high property level, good hydrolysis resistance, low temperature behavior and excellent hygienic properties, making it particularly suitable for use as, for example, shoe and sports shoe material, artificial leather clothing material, padding material, etc.

Characteristic of the known technical solutions

Penetration of fibrous substrates with polymers or polymer blends to increase the strength and to achieve special properties are known. Such partially or fully penetrating networks are as follows:

According to DE-PS 3,117,894 there are e.g. for the bonding of nonwovens or for the creation of special properties, the possibility of treating them with PUR solutions. The solutions are fully reacted elastic PURs, which are made from long-chain PEs and PEt diols and diisocyanates as well as OH- and amine-containing chain extenders. Evaporation of the solvent results in compact fiber coatings, with the fibers adhered to the entangling points.

As described in the patents JP 56-85,479 and DE-PS 2,639,060, the nonwoven fabrics impregnated with solvent systems can also be solidified by coagulation of the PU by non-solvents. Inhomogeneous phases are fixed out of the solution and, in addition, a certain poromeric structure is generated, which, however, does not function as a property-carrying structural element.

- A solidification of fiber webs can also be done according to DE-PS 1,286,991 by applying a reactive system in two steps successively as NCO-containing prepolymer and OH-containing hardener component by subsequent heat exposure by fiber bonding with compact PUR.

- For the production of PUR-impregnated nonwovens or Durchdringungsverbunden is, as in the patents

JP 78-81 574, JP 78-142,167, JP 78-143,660 and US-PS 4,110,317, the possibility of impregnation with low solvent containing 2-component systems based on branched PEt / PEs-Pölyol with tolylene diisocyanate and diol as a chain extender (NCO: OH = equivalent), whose curing is carried out by means of catalyst in 80 ⁰ C warm water, which except compact fiber wetting or solidification coagulated desired poromeric structures occur to a small extent.

All of these products have the following shortcomings: they are essentially fiber compact coatings in the sense of impregnation with a high degree of bonding of the fibers to one another, which considerably impairs softness, with only minor poromeric proportions which do not significantly or independently influence the overall property image That is why these products only insufficiently meet the hygienic requirements for artificial leather or the desired leather-like softness.

Object of the invention

The aim of the invention is a penetration composite of nonwoven fabric and an elastic PUR, which serves for fiber consolidation, without the soft basic character of the fiber structure is substantially impaired, the composite contains a high degree of a self-contained microporous foam portion, which contributes significantly to the strength properties and at the same time a high Level of personal hygiene causes.

Explanation of the essence of the invention

According to the invention, the object is achieved in that from a nonwoven fabric and a per se known elastic NCO-containing polyurethane one-component system with additives such as foam regulators, color pigments, flame retardants, etc., the per se known methods such as doctoring, rolling, impregnating, etc. in the Nonwoven fabric is introduced in the desired amount and penetration depth up to 100%, by curing in a humidity-heat-climate of 20-100 ⁰ C, preferably 35-60 ⁰ C, and a relative humidity of 30-100%, preferably 65-85 %, a Durchdringungsverbund is formed, which is characterized in that the nonwoven fibers are provided to a small extent with a fine-pored thin polyurethane coating, wherein a small part of Faserverschlaufungsstellen and Fasererkreuzungsstellen is punctiform and / or connected by peg-shaped slats, resulting in significant solidification of the Gesamtverbundes, without significantly affecting its softness, w the bulk of the incorporated polyurethane forms a self-contained foam phase, whereby the overall strength and the hygienic properties are substantially determined, so that the penetration composite is an artificial leather material of almost isotropic strength and very good breathability, which is suitable for clothing, shoe materials, upholstery materials, vehicle equipment, Bags and folders, straps, conveyor belts and belt work can be used for machines, grips and other applications.

Nonwovens suitable for the interpenetration composite can be constructed by compression, needling, compaction or other suitable method from natural, synthetic fibers, regenerated fibers or mixtures thereof. The mixing of different types of fibers gives rise to the possibility of influencing the properties of the fiber substrate and polymer composites. The composition of the nonwoven additionally controls the proportion of wetted and non-wetted fibers. Wettable fibers are z. Cellulose, cotton, polyester, polyamide and polyacrylonitrile fibers. Non-wettable fibers are z. For example, polyethylene and polypropylene fibers.

Suitable PUR systems for the penetration composite are z. B. NCO-containing prepolymers consisting of one or more polyhydroxy compounds of functionality 1.75-4.5, preferably the functionality 2-3, one or more isocyanates of functionality 1.5-3, preferably 2-3, catalysts, fillers , Pigments and / or other additives. Preferred polyhydroxy compounds are polyether alcohols of the functionality 2-3 of one or more alkylene oxides of the mean equivalent weights 500-5000, preferably 1000-2500. Preference is given to mixtures of polythene diols and polyether triols of different equivalent weights. Suitable isocyanates are tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, their mixtures technical products or reaction products with low molecular weight di- and / or polyalcohols. Suitable catalysts are tertiary amines such as Ν, Ν, Ν ', Ν'-tetramethylbutanediamine, triethylenediamine, dimethylcyclohexylamine, etc. possibly in admixture with organometallic catalysts. Suitable additives are conventional foam regulators, flame retardants such as antimony trioxide, tris- (2-chloroethyl-lphosphate and alumina hydrate, pigments, organic dyes, matting agents such as silicones etc. The penetration composite according to the invention is preferably prepared by the following process: A suitable fibrous substrate, for example a Needle web of 80% polyester fibers and 20% polypropylene fibers, is clamped in a coating system and by means of a coating, drawing, spraying, printing, pouring, troweling or rolling device with the dyed prepolymer in a dry atmosphere with a layer thickness of 0 , 1-0,5mm applied.

The prepolymer penetrates into the nonwoven. Immediately thereafter, curing takes place within 20-180 sea. at 20-80 ⁰ C and 50-90% relative humidity.

At 5O ⁰ C and 70% relative humidity, curing is completed in 2min. Thereafter, one of the following processes can be carried out with the material.

- The Verbundmateriai is made up, since it has already reached its final state.

- The composite material is separated by cutting in the desired thickness.

- The composite material is treated by thermal pressure treatment at temperatures of 180-220 ° C and a pressure of 0.01-1 MPa and thus densified the surface smooth.

- The composite material is roughened by sanding, brushing, etc., thereby preserving the character of suede.

- The composite material is provided with a compact or porous cover layer.

Example:

A penetration compound of 1.2 mm thickness consisting of a needle felt (300 g / m ² ) consisting of 80% polyester fibers and 20% polypropylene fibers and a PUR (160 g / m ² ) whose base composition consists of 36 parts tolylene diisocyanate, 170 parts of a triol Basis glycerol and propylene oxide / ethylene oxide of average molar mass 3500.80 parts of polypropylene glycol average molecular weight 2000 and 10 parts of dipropylene glycol, has the following property profile:

Tear force longitudinal: 90 N TGIL34266 / 01

Elongation at break: 68% TGL34266 / 01

Tear force: 74N TGL34 266/01

Elongation at break across: 74% TGL34266 / 01

Tensile strength + elongation at break were determined using type 2 specimen according to TGL 35700.

Tear propagation longitudinal and transverse: 47N TGL 34 266/01

Flexural rigidity: 100N-m TGL29423

Water vapor permeability: TGL 0-53333

900mgH ₂ O / 10cm ² -d

Water vapor pickup: 10.2mgH ₂ O / cm ² -d TGL15 / 1105

Tropical test (14 d, 70 ⁰ C, 100% relative humidity.): 100% GlasübergangstemperaturT _g: -58 ⁰ C.

Bending behavior at +20 ⁰ C: TGL32 935

150,000 kinks

Bending behavior at -10 ⁰ C TGL32935

20,000 kinks

Claims (10)

1. Soft penetration composite consisting of nonwoven fabric and polyurethane, wherein a nonwoven fabric of synthetic, natural or regenerated fibers or mixtures thereof may consist of and pretreated or pre-consolidated in different ways and a polymer may have penetrated the cross section of the nonwoven fabric in whole or in part, with almost isotropic strength and very good breathability and hydrolysis resistance and low temperature behavior, characterized in that the nonwoven fibers are partially provided with a fine-pored thin polyurethane coating, that a small part of Faserverschlaufungsstellen and Fasererkreuzungsstellen is punctiform and / or connected by bubble-shaped lamellae and that the majority of Polyurethane is an independent property-determining foam phase. 2. Durchdringungsverbund according to item 1, characterized in that the polyurethane of toluene diisocyanate, at least one polyether alcohol of functionality 2-3 having a molecular weight of 1,000-5,000, at least one short-chain diol of molecular weight 62-600 and from a tertiary amine catalyst exists, possibly with the addition of other additives. 3. Penetration composite according to item 1, characterized in that the nonwoven fabric consists of regenerated fibers, natural or artificial fibers or mixtures thereof, which have been pretreated possibly by pressing, needling, compacting, shrinking and / or impregnating. 4. Penetration composite according to item 1, characterized in that it has been treated by grinding, roughening, brushing, pressing, embossing, rolling or ironing. 5. Penetration composite according to item 1-4, characterized in that the material is processed into leatherette clothing. 6. Durchdringungsverbund according to item 1-4, characterized in that the material is processed into shoes or shoe parts. 7. Durchdringungsverbund according to item 1-4, characterized in that the material is processed into folders and bags. 8. Penetration composite according to item 1-4, characterized in that the material is processed into upholstery and automotive equipment. 9. Durchdringungsverbund according to item 1-4, characterized in that the material is processed into straps, conveyor belts and machine belt. 10. Penetration composite according to item 1-4, characterized in that the material is processed into handle mantles, tennis, golf or table tennis racket wraps, steering wheel wrappings etc. with high grip and breathability.