EP0518014A1 - Mouldable floor carpets - Google Patents

Abstract

2. The object was to produce 3D-deformable, recyclable floor carpets. This object has been achieved by floor carpets composed of the following components: a) a carpet upper made from partially crystalline polyolefin, b) a backing made from a moulding composition containing the following components: - from 10 to 95% by weight of one or more substantially amorphous polyolefins having the monomer composition from 0 to 80% by weight of an alpha -olefin having 4 to 10 carbon atoms, from 20 to 100% by weight of propene and less than 20% by weight of ethene; - from 5 to 90% by weight of one or more partially crystalline polyolefins; - a maximum of 70% by weight of fillers; c) a backing reinforcement in the form of a nonwoven material, supporting mesh, woven material or knitted material of partially crystalline polyolefin or of glass. Floor carpets of this type are particularly suitable for use in the footwells or boot of motor vehicles.

Description

The invention relates to three-dimensionally deformable, recyclable floor carpets, in particular car floor carpets and a method for their production.

Three-dimensionally deformable floor carpets currently in use consist of plastic or textile composites, the individual components of which are more or less alien. Such carpets are in several, z. T. labor-intensive process steps obtained as a formable composite, for example by providing a tufting or a needle fleece, which consist predominantly of polyethylene terephthalate (PET), polyacrylic or PET blends with polypropylene fiber components, on the back with a latex application and then layers of different Applies materials that should ensure mechanical stability and good lying behavior.

Floor carpets of this type have, in addition to the elaborate production, the particular disadvantage that, because of the combination of foreign materials, neither the punching waste during the shaping, which can be up to 40%, nor the molded part can be recycled in the disposal of used cars.

• 1) Der Bodenteppich muß aus einer Kombination artgleicher Materialien bestehen, um eine Wiederverwertung zu ermöglichen;
• 2) die Rückenbeschichtung muß bei Heiztemperaturen verformbar sein, bei denen die Teppichoberseite nicht geschädigt wird;
• 3) die Rückenbeschichtung muß einerseits eine ausreichende Flexibilität besitzen, andererseits unter den Gebrauchsbedingungen formstabil sein;
• 4) der Teppichboden muß unter Vermeidung von Vielfachverbund-Kombinationen einfach herstellbar sein.

The task therefore was to provide floor carpets that meet the following conditions:

• 1) The floor carpet must consist of a combination of identical materials in order to enable recycling;
• 2) the back coating must be deformable at heating temperatures at which the top of the carpet is not damaged;
• 3) the back coating must on the one hand have sufficient flexibility and on the other hand be dimensionally stable under the conditions of use;
• 4) the carpet must be easy to produce, avoiding multiple composite combinations.

• a) Die Teppichoberseite, üblicherweise ein Gewebe, Gewirke, Tufting oder Nadelvlies, besteht aus teilkristallinem Polyolefin, vorzugsweise Polypropylen.
• b) Die Rückenbeschichtung besteht aus einer Formmasse, die folgende Komponenten enthält:
  • 10 bis 95 Gew.-% eines oder mehrerer weitgehend amorpher Polyolefine der Monomerenzusammensetzung
    0 bis 80 Gew.-% eines α-Olefins mit 4 bis 10 Kohlenstoffatomen,
    20 bis 100 Gew.-% Propen und
    weniger als 20 Gew.-% Ethen;
  • 5 bis 90 Gew.-% eines oder mehrerer teilkristalliner Polyolefine, vorzugsweise Polypropylen;
  • maximal 70 Gew.-% Füllstoffe.
• c) Rückenverstärkung in Form eines Vlieses, Stützgitters, -gewebes oder -gewirkes aus teilkristallinem Polyolefin, vorzugsweise Polypropylen, oder aus Glas.

This task was solved by floor carpets, which are composed of the following components:

• a) The top of the carpet, usually a fabric, knitted fabric, tufting or needle fleece, consists of partially crystalline polyolefin, preferably polypropylene.
• b) The back coating consists of a molding compound that contains the following components:
  • 10 to 95 wt .-% of one or more largely amorphous polyolefins of the monomer composition
    0 to 80% by weight of an α-olefin with 4 to 10 carbon atoms,
    20 to 100 wt .-% propene and
    less than 20 wt% ethene;
  • 5 to 90% by weight of one or more partially crystalline polyolefins, preferably polypropylene;
  • maximum 70% by weight fillers.
• c) back reinforcement in the form of a fleece, support grid, woven or knitted fabric made of partially crystalline polyolefin, preferably polypropylene, or of glass.

Self-supporting polyolefin laminates on the basis of a rigid support made of a polyolefin plate, which on one or both surfaces without the interposition of adhesives with a flexible layer based on polyolefin, e.g. B. a fabric or nonwoven fabric made of isotactic polypropylene, are known from DE-A-31 00 682. However, their rigidity causes their resonance frequency to be within the audible range; the sound absorption is low. Since they also cannot adapt to the subtleties of the floor geometry, they are unsuitable as floor carpets.

GB-A 2 072 578 describes sound-absorbing floor carpets whose backing coating contains a polyolefin, a synthetic rubber, petroleum oil in considerable quantities and an inorganic filler. A serious disadvantage of this composition is that the very high melt viscosity of the combination of polyolefin / synthetic rubber / filler has to be reduced to a level which is sensible in terms of processing technology by adding the oil. However, the presence of an oil is undesirable for several reasons. Since it naturally tends to exude, it can cause serious fogging problems. Adhesion to the top of the carpet also deteriorates, which is why you have to cover it with latex before applying the backing. Finally, the presence of oil and latex is undesirable for recycling.

This document also gives no information as to whether the floor carpets described there can be three-dimensionally deformed after they have been manufactured.

The floor carpets of the present invention, on the other hand, are easily recyclable, can be three-dimensionally deformed without difficulty, give no cause for fogging, are easy to produce and have good flexibility and good sound-absorbing and sound-absorbing effects.

Isotactic polypropylene is preferably used as the material for the top of the carpet for reasons of good recyclability. Homopolymers and copolymers can be used; the homopolymer is preferably used. According to the prior art, the polymer can contain the usual amounts of pigments, stabilizers, processing aids, antistatic agents and the like.

In the back coating as a largely amorphous polyolefin z. B. atactic polypropylene in the form of homo- or copolymers. Atactic polypropylene (APP) and / or binary or ternary copolymers of the monomers butene-1, propene and optionally ethene are preferably used. Such copolymers can be produced by targeted polymerization on classic Ziegler catalysts or their further developments, as described for example in DE-PS 23 06 667 or DE-PS 29 30 108. In general, the largely amorphous polyolefins have a degree of crystallization of at most 25%, determined by X-ray diffraction.

In a preferred embodiment, a largely amorphous polyolefin with a softening point (ring and ball method) between 70 and 160 ° C, a melt viscosity according to ASTM D 3236-73 at 190 ° C between 2,000 and 200,000 mPa s, a density lower as 0.90 g / cm³ and a needle penetration 100/25/5 according to DIN 52 010 between 5 and 50 0.1 mm. Particularly preferred, largely amorphous polyolefins have a softening point between 90 and 150 ° C, a melt viscosity at 190 ° C between 5,000 and 150,000 mPa s and a needle penetration between 15 and 40 0.1 mm.

In principle, any polymer that is also suitable for the top of the carpet can be used as the semi-crystalline polyolefin for the back coating. However, higher molecular weight PP random or block copolymers are preferably used.

According to the prior art, at least part of the largely amorphous polyolefin and / or the partially crystalline polyolefin can be grafted with free radicals with monomers containing double bonds which carry at least one functional group. Suitable polymer mixtures are described, for example, in EP-A 0 309 674, to which reference is hereby expressly made.

For example, chalk, talc, mica, heavy spar, similar rock flour, glass fibers and / or glass balls can be used as fillers be used. Chalk and / or heavy spar are preferably used. The average particle diameter should not exceed 150 µm.

The molding compound of the back coating can be produced from the components by all customary methods, in particular by melt mixing.

As a rule, the back coating has a thickness of approximately 0.2 to approximately 5 mm.

The back coating contains a fleece, support grid, mesh or knitted fabric, from which it is usually embedded. The same polymers are suitable as materials as they can also be used for the top of the carpet.

The composite can be produced in various ways, for example by lamination or coating. It can be obtained particularly advantageously by extrusion coating.

After manufacture and, if necessary, cutting, the composite can be deformed three-dimensionally, for example by compression molding or vacuum molding. For this purpose, it first runs through a heating field in which the molded part is brought to a temperature at which the back coating softens, but the fibers on the top of the carpet are still dimensionally stable.

Floor carpets of this type are particularly suitable for use in motor vehicles, where in this way the composite can easily be adapted to the contours of, for example, the footwell or the trunk.

The punching waste or the entire molded part can be easily recycled. For this purpose, the material is crushed in the usual way and fed to an extruder, where other substances can be mixed. The mass obtained can be used, for example, for the back coating. Since only thermoplastic polymers of the same type are contained, no delamination or speck formation is observed.

Example:

A tufting velor made of 100% polypropylene homopolymer of 360 g / m² (without back bracing as otherwise necessary for pole binding) was used in a width of 2 m with a fiber pile height of 4.5 mm and a fiber titer of 17 dtex.

This carpet velor was fed from a 3-roll smoothing calender (working width 2.40 m). After passing through the first roller, a melt film consisting of an extruder was then passed through a slot die
33 1/3% random copolymer VESTOLEN P 8400,
33 1/3% amorphous directly polymerized atactic polypropylene VESTOPLAST 891 and
33 1/3% heavy spar batch, consisting of 70% by weight heavy spar and 30% by weight polypropylene homopolymer
on the back against the carpet velor with a 60 g / m² polyolefin net (grid size 1.2 x 1.5 mm) made of VESTOLEN A 6012. A single-screw extruder (120 mm ⌀ screw diameter) with a dynamic mixer, melt pump, static mixer and flex-lip nozzle (2.20 m working width) was used as the extruder. The union was brought together via the smoothing calender.

Adequate bond adhesion was achieved by setting the smoothing roll gap 10% less than the total thickness of the bond to be produced.

The carpet produced in this way can be fed to the thermoforming process in rolls or in format sizes.

Molding process

Starting from the roll, the carpet composite was held by means of a needled chain feed (with a stylus) and transported to the forming station.

The heating process was carried out on both sides by infrared radiators via separately controllable longitudinal heating controls below the melting range of the fiber top, so that this was not thermally damaged. A perfect, sharp-contoured deformation was then carried out by press molding. The molded part was punched out during this pressing process.

The punching waste (approx. 40% by weight) was used in a further production approach of the same type as a component of the back coating, the calculated amounts of the individual primary components of the back coating (in total 48% by weight) being substituted by the corresponding amount of the crushed punching waste . Here, a composite of equal quality was obtained.

Claims (8)

Floor carpet composed of the following components: a) top of carpet made of partially crystalline polyolefin; b) back coating from a molding compound which contains the following components: - 10 to 95 wt .-% of one or more largely amorphous polyolefins of the monomer composition

0 to 80% by weight of an α-olefin with 4 to 10 carbon atoms,
20 to 100 wt .-% propene and
less than 20 wt% ethene; 5 to 90% by weight of one or more partially crystalline polyolefins; - a maximum of 70% by weight of fillers; c) back reinforcement in the form of a fleece, support grid, woven or knitted fabric made of partially crystalline polyolefin or glass. Floor carpet according to claim 1,
characterized,
that, independently of one another, the top of the carpet, the partially crystalline polyolefin component of the back coating and / or the back reinforcement consist of polypropylene. Floor carpet according to claim 2,
characterized,
that the polypropylene is a homo- or copolymer. Floor carpet according to one of claims 1 to 3,
characterized,
that atactic polypropylene (APP) and / or binary or ternary copolymers of the monomers butene-1, propene and optionally ethene are used as the largely amorphous polyolefin of the back coating. Floor carpet according to one of claims 1 to 4,
characterized,
that chalk, talc, mica, heavy spar, similar rock flour, glass fibers and / or glass balls are used as filler for the back coating. Process for the production of floor carpets according to claims 1 to 5,
characterized,
that the back coating is applied by extrusion coating and then calendered. A method according to claim 6,
characterized,
that the composite is then three-dimensionally deformed. Use of a floor carpet according to one of claims 1 to 5 or a floor carpet produced by the method according to claim 6 or 7 in motor vehicles.