EP0168835B1 - Cut pile fabric with a reduced tendency to shade, process for its manufacture and yarns therefor - Google Patents

Description

The present invention relates to a cut pile carpet with reduced tendency to shading, a method for reducing shading on cut pile carpets, carpet yarns therefor and the use of solutions, emulsions or dispersions containing film-forming polymers or prepolymers therefor.

Cut pile carpets are textile floor coverings with cut pile nubs, which are also referred to as velor. This includes not only machine-made carpets, but also hand-knotted carpets, provided they have cut polen knobs. The cut pile carpets can be plain, multi-colored or patterned.

The term “shading” refers to patchy changes in the cut pole of carpets. However, these are not caused by color changes, but by a partial, irreversible change in the original line direction of the pile threads. Such line deviations lead to a change in the light reflection at the affected areas, as a result of which spot-like structures become visible.

The shading effect is therefore an optical appearance, which may adversely affect the quality of representation of a carpet product to a greater or lesser extent, but does not affect the durability.

It is known that the shading effect can occur on all cut pile carpets, regardless of the pile fiber materials used. These effects affect natural fibers (e.g. keratin fibers such as wool, coconut fibers) as well as chemical fibers (e.g. polyamide, polyester, polyacrylic). Shading also occurs with all types of thread build-up, i.e. with filament yarns as well as with spun fiber yarns, also with single yarns and twists. The same applies to all manufacturing processes for cut pile carpets, which means that the effect can occur with woven tufted and glued carpets. This also affects all common types of installation (loosely laid, braced, glued) and all types of subfloor (e.g. wood, plastic, screed, etc.). It is also known from experience that shading arises again on cut pile carpets, which are replaced on the spot due to shading formation.

The only typical characteristic of shading is - as already indicated - the irreversibility of the shifting of the pole from its original line direction. This means that the line deviations can neither be removed by mechanical means nor by the additional influence of moisture.

It is also characteristic of shading that the blotchy appearances often pass seamlessly from one web to the other, even when cut pile carpets from different manufacturers are laid side by side.

Despite intensive research in this area, it has so far not been possible to clarify the causes of shading. The assumption that local environmental influences - such as slight differences in humidity, temperature and air speed - could trigger shading has not been proven by measurement.

Attempts have been made in various ways to reduce or prevent shading from occurring. According to DE-B-1 123 630, this was attempted by using yarns with the opposite direction of rotation. According to another proposal, the design data such as fiber titer, yarn count, machine pitch, pile height and fabric weight are to be changed in a targeted manner (see chemical fibers / textile industry 29/81 (1979), pages 602 to 607). According to BE-A-876236, success is to be achieved by conductive bonding of the carpet. According to DE-A-30 33 124, natural, metallic, chemical or physical agents are to be used to shield against earth rays, which is intended to prevent shading.

However, all of these methods have not led to an even approximately satisfactory solution to the problem of the occurrence of shading.

The present invention is based on the object of effectively preventing the occurrence of shading on cut pile carpets in a simple manner.

The invention accordingly relates to a cut pile carpet with a reduced tendency to shading, which is characterized in that the pile fibers, preferably in the region of the nub legs above ground, are completely or partially covered with a film-forming polymer in such a way that at least some of the pile fibers are covered by the film-forming one Polymer is interconnected

• (a) durch Behandlung des Teppichs auf die Polfasern, vorzugsweise im Bereich der Noppenschenkel über Grund, eine Lösung, Emulsion oder Dispersion, enthaltend filmbildende Polymere oder Prepolymere, aufgebracht wird, wobei das Lösungsmittel verdunstet und gegebenenfalls der behandelte Teppich zur Härtung des Polymer oder Prepolymer erwärmt wird, oder
• (b) auf das Teppichgarn eine Lösung, Emulsion oder Dispersion, enthaltend filmbildende Polymere oder Prepolymere, aufgebracht wird, wobei das Lösungsmittel verdunstet und gegebenenfalls das Garn oder der daraus hergestellte Teppich zur Härtung des Polymers oder Prepolymers erwärmt wird.

The invention further relates to a method for reducing shading on cut pile carpets, which is characterized in that

• (a) a solution, emulsion or dispersion containing film-forming polymers or prepolymers is applied to the pile fibers, preferably in the region of the pimples above the ground, by treating the carpet, the solvent evaporating and, if appropriate, the treated carpet for curing the polymer or prepolymer is heated, or
• (b) a solution, emulsion or dispersion containing film-forming polymers or prepolymers is applied to the carpet yarn, the solvent evaporating and, if appropriate, the yarn or the carpet produced therefrom being heated to harden the polymer or prepolymer.

The invention furthermore relates to a carpet yarn for producing cut pile carpets with reduced tendency to shading, which is completely or partially covered with a film-forming polymer.

The invention also relates to the use of solutions, emulsions or dispersions containing film-forming polymers or prepolymers for the treatment of carpets and carpet yarns to reduce shading.

The invention is applicable to all cut pile carpets as described in the introduction. Particularly good results have been achieved on carpets whose pile consists of keratin-containing fibers, preferably wool, and the corresponding carpet yarns.

The amount of film-forming polymer with which the pile fibers are coated is at least so large that at least some of the pile fibers are connected to one another in parts by the film-forming polymer. This amount depends to a certain extent on the pile fiber materials and the construction of the carpet. It also depends on the type of polymer. In general, a sufficient effect is achieved if the amount of the film-forming polymer, based on the pile weight of the carpet, is at least 0.01, advantageously at least 0.05 and preferably at least 0.1% by weight. The upper limit also varies depending on the above parameters. If possible, no more polymer should be applied than is necessary to achieve a significantly reduced tendency for shading. The amount of film-forming polymer should therefore not be more than 10, suitably not more than 5, preferably not more than 2 and particularly preferably not more than 1% by weight, based on the pile weight of the carpet. Too large quantities are not only inappropriate for economic reasons. The amounts used should also not be so large that the other properties of the carpet, such as the handle, are adversely affected. It is a particular advantage of the invention that such small amounts of polymers can be used, thereby avoiding any appreciable disadvantageous influence on the carpet properties.

Pole weight is understood to mean the weight of the pole material over the carrier or base layer.

To reduce the shading of carpets, the carpet yarns used for carpet production can also be coated with the film-forming polymer. Again, the amount depends on the type of material used, the construction of the carpet and the type of polymer. In general, a sufficient effect is achieved if the amount of the film-forming polymer, based on the yarn weight, is at least 0.01, suitably at least 0.05 and preferably at least 0.1% by weight. The upper limit also varies depending on the above parameters. If possible, no more polymer should be applied than is necessary to achieve a significantly reduced tendency for shading. The amount of film-forming polymer should therefore not be more than 10, suitably not more than 5, preferably not more than 2 and particularly preferably not more than 1% by weight.

The solution, emulsion or dispersion of film-forming polymer can be applied to the pile fibers in various ways. The order is preferably from the pole side, for. B. by small order so that the pile fibers are wetted by the treatment liquid. But it is with carpets that are sufficiently permeable to liquids from the back, e.g. B. raw goods, possible to apply the treatment liquid to the back so that the liquid passes through the base fabric or carrier material to the pile fibers. This procedure clearly differs from the application of a primer for anchoring the studs in the base layer or the foaming of the back of the carpet, because in these cases the treatment liquid should and should be prevented from reaching the entire area of the pile fibers. But it is also possible to treat the entire carpet with the aqueous solution, emulsion or dispersion, e.g. B. to impregnate or immerse in the treatment liquid.

It is preferably applied to the pile fibers by treating the entire carpet on a piece dyeing machine. The treatment can also take place during dyeing. The treatment of carpet yarns can be carried out on conventional yarn dyeing machines (package winder, strand and continuous yarn dyeing machines), belt washing machines or on any apparatus or machine which enables wet treatment of yarns.

As already stated, it is preferred, essentially for reasons of the simple procedure and the material saving, that the aqueous solution, emulsion or dispersion containing film-forming polymers or prepolymers is applied to the pile side of the carpet. In order to achieve good and rapid wetting of the pile fibers, it is expedient for the treatment liquid to contain a customary wetting agent. Examples of such wetting agents are anionic and nonionic surfactants such as salts of fatty acids, alkyl, aryl or alkylaryl sulfates or sulfonates, alkyl, aryl or alkylaryl polyglycol ethers or esters, etc. Such commercial products are e.g. B. Arbyl R ^e (polyglycol ether), Duponol LS® (sodium oleyl sulfate), Invadin JFC conc.® (alkylphenol ethoxylate), Leophen LG ° (mixture of sodium salts of aliphatic sulfonic acids), Perenin GNSC "* (fatty alcohol polyglycol ether mixture).

So-called rapid wetting agents are particularly advantageous because rapid wetting of the fibers of the carpet is desired in order to bring about a rapid and uniform distribution of the treatment liquid and thus of the film-forming polymer on the carpet fibers.

Such rapid wetting agents include polyethylene oxide adducts of aliphatic or aromatic alcohols with a relatively small proportion of ethylene oxide (low HLB value), e.g. B. Nilin GX ^* or sulfosuccinic diester salts, e.g. B. Leophen RA _, ".

According to the invention, polymers of the most varied types can be used as film-forming polymers, e.g. B. those polymers that form a film after evaporation or evaporation of the solvent without curing, as well as those polymers or prepolymers that harden after application to the carpet or carpet yarn. The term «prepolymers also includes mixtures of compounds which can be polymerized with one another, including mixtures of polymeric compounds with monomeric compounds which react with the polymeric compounds to increase their molecular size.

The term "hardening" is understood to mean that the prepolymers or polymers react by increasing the molecular size, as a result of which their solubility is reduced or reduced to such an extent that the hardened polymers are practically no longer soluble if the carpet comes into contact with water during use. The treatment liquid can contain hardening or accelerating additives in the usual way.

Additives are those that contain at least two reactive groups per molecule, e.g. B. di- or polyamines and di- or polythiols in question. On the other hand, catalysts and / or accelerators can be used in self-crosslinking polymers, such as acids in acid-curing prepolymers and bases in alkaline-curing prepolymers.

Hardening can also be achieved by exposure to elevated temperatures. The choice of hardener and temperature naturally depends on the hardening mechanism of the polymers or prepolymers used. Naturally, only those polymers and prepolymers can be used that cure under conditions (alkali or acid content and temperatures) that do not damage the carpet.

Examples of usable polymers and prepolymers are polyamides, such as a cationic polymer (Hercosett 57 ^@ ) made from adipic acid and diethylenetriamine and reacted with epichlorohydrin, polyether based on polyethylene oxide, polypropylene oxide or polytetrahydrofuran, polyester based on aliphatic or aromatic dicarboxylic acids and dialcohols. They can contain reactive groups such as thiol, thiomalate, isocyanate, carbamoyl sulfate, thiosulfate, thioglycolate or sulfonium bromide, epoxy, aziridine etc. Commercial products of this type are e.g. B. Synthappret LKF8 (polyether triisocyanate), Synthappret BAP @ (polyether tricarbamoyl sulfate), Lankrolan SH 3 ^@ (polyether trithiosulfate, polysiloxanes such as polydimethylsiloxane. The latter polymers may also contain reactive groups such as thiol or hydroxyl groups. The use of a crosslinking agent is such as a di- or polyamine necessary in many cases, polyacrylate and methacrylate copolymers of various structures, as described, for example, in DE-A-26 38 386, can also be used, and these polymers can also contain reactive groups such as N-methylol or epoxide -, Aziridine groups etc. An addition of crosslinking agents or catalysts can also be expedient here, for example acids in the case of polymers containing N-methylol groups or polyamines in the case of polymers containing epoxide groups.

Hydrophilic or water-soluble polymers can expediently be used in the form of aqueous solutions or dispersions. Stabilized emulsions or dispersions of hydrophobic polymers can also be used. These systems expediently contain the usual emulsifiers and / or stabilizers.

Particularly good results were achieved with the commercial product Synthappret BAP ⁸ (polyether tricarbamoyl sulfate). This product and the preparation of aqueous solutions thereof are e.g. B. in DE-A-23 07 563 and DE-A-24 14 470 described in detail.

The treatment liquid (solution, emulsion or dispersion) of film-forming polymers or prepolymers is expediently applied from a short liquor, expediently in a ratio of pile weight to liquor quantity from 10 1 to 1:10. The upper limit is preferably 5: 1, particularly preferably at 2: 1. The lower limit is preferably 1: 5, particularly preferably 1: 2. In principle, however, it is also possible to work with longer liquors, but the use of large amounts of water is generally not advantageous for economic reasons.

Particularly good results have been achieved if the treatment liquid is applied as foam only to the pile side of the carpet. This can be done immediately after the carpet is finished, without the need for extensive additional machinery. You can e.g. B. suitable for dyeing devices for the method according to the invention. If the solution, emulsion or dispersion according to the invention is used as a foam, it is expedient to add suitable foaming agents according to the prior art. Examples include: a. the anionic and nonionic surfactants already mentioned as wetting agents.

Known foam stabilizers such as polyvinyl alcohol, hydroxymethyl or hydroxyethyl cellulose or polyelectrolytes such as polyacrylic acids, etc. can be used to extend the life of foam.

The reason for the surprising effect which is achieved according to the invention has not been fully clarified. A shift of the pole is apparently prevented by the fact that a part of the pile fibers is connected to one another in parts by the film-forming polymer. It is astonishing that an extremely small amount of polymer used has an excellent effect on this effect. According to the invention, not only can a reduced tendency of shading be brought about, but the formation of shading can be practically completely prevented. So far this has not been possible.

The concentration of polymers or prepolymers in the treatment liquid depends on that Liquor ratio in combination with the desired amount of polymers to be applied. It can be calculated from the specified data. The lower limit for the concentration is expediently about 0.01 g / liter of liquid. The upper limit is expediently about 100, preferably about 50, particularly preferably 20 g / liter of liquid.

example 1

• 4 g/l Prepolymer, Synthappret BAP⁸ (BAYER AG) (Polyethertricarbamoylsulfat, 50 %-ige Lösung)
• 5 g/I Verschäumungsmittel, Pentasol BN^@ (Hansawerke) (Alkylbetain, 50 %-ige Lösung)
• 0,75 g/I Netzmittel, Nilin GX@ (Alkylpolyglykolether)
• 1 g/I Natriumcarbonat, wasserfrei.

The foam described below was applied to 50 x 100 cm pieces of a woven velor carpet with a pile layer of pure wool. The untreated carpet showed a pronounced tendency to form shading. Its weight per unit area was 2,800 g / m ² , the pile weight 900 g / m ² , the total thickness 9.5 mm and the pole height 5.8 mm. A foamed liquor with a foam liter weight of 94 g / l was applied to the sample pieces in an amount of 100 parts by weight of foam per 100 parts by weight of carpet pile. The fleet had the following composition before foaming:

• 4 g / l prepolymer, Synthappret BAP ⁸ (BAYER AG) (polyether tricarbamoyl sulfate, 50% solution)
• 5 g / I foaming agent, Pentasol BN ^@ (Hansawerke) (alkyl betaine, 50% solution)
• 0.75 g / l wetting agent, Nilin GX @ (alkyl polyglycol ether)
• 1 g / l sodium carbonate, anhydrous.

The sodium carbonate serves as a catalyst or as an accelerator for the curing of the polymer. The foamed test pieces were then dried in a drying cabinet at 140 ° C. for 10 minutes.

The handle of the carpet was not changed visibly.

Some of the carpet samples treated in this way were laid in the production direction on a test track which was characterized by an extremely high frequency of walking (8,000 walks per week). After a test period of 6 months (approximately 200,000 inspections), the sample according to the invention had no discernible shading formation, while the unequipped control samples laid in the same place showed pronounced shading effects.

The remainder of the treated samples were laid on a special shading test track, on which velor goods previously laid out showed clear shading effects in a very short time (from 1 to 3 weeks). After a four-month test period, the finished samples remained shading-free, the unequipped sample showing pregnant shading effects.

In order to be able to assess the contamination of the samples, all samples, i.e. H. on samples according to the invention and on untreated control samples, the color location is determined by color measurement. The measurements showed that the carpet treated according to the invention was less soiled (color locus: 0.46) than the carpet that was not equipped (color locus: 1.3).

Example 2

• 20 g/I Synthappret BAP⁸
• 1 g/I Natriumcarbonat, wasserfrei
• 1 g/I Nilin GX⁸

Yarn strands of 100% virgin wool with a fineness of Nm 6.1 were prewashed in a continuously operating belt washing machine and then soaked in the following solution for 2 minutes:

• 20 g / l Synthappret BAP ⁸
• 1 g / l sodium carbonate, anhydrous
• 1 g / l Nilin GX ⁸

The yarn was then squeezed to 100% moisture and then dried in a sieve drum dryer at a chamber temperature of 110 ° C.

A carpet was produced from this yarn as described in Example 1 and tested on the test track mentioned. After three months of testing, the untreated control sample showed strong shading effects, while the treated shading remained free.

Example 3

• 6,5 g/I Synthappret BAP®
• 1 g/I Natriumcarbonat, wasserfrei
• 1 g/I Nilin GX®

A piece of carpet 200 m long was treated in a reel skid at a liquor ratio of 1:30 with the following solution for 10 minutes at room temperature:

• 6.5 g / l Synthappret BAP®
• 1 g / l sodium carbonate, anhydrous
• 1 g / l Nilin GX®

The carpet was then vacuumed on the pole side, after which the residual moisture content was 300% (based on the weight of the goods).

The carpet was then dried at 140 ° C for 10 minutes. From this carpet samples were taken and tested on the test section mentioned in Example 1. The treated carpet samples remained shading-free after a 3-month test period, while the untreated control samples clearly showed shading.

Claims (17)

1. A cut pile carpet having a reduced tendency towards shading, characterized in that the pile fibers are completely or partly coated with a film-forming polymer in such a way that at least some of the pile fibers are joined to one another by the film-forming polymer.

2. A cut pile carpet as claimed in Claim 1, characterized in that the pile fibers are coated above the backing at the sides of the loops.

3. A cut pile carpet as claimed in Claim 1 or 2, characterized in that the film-forming polymer is applied in a quantity of at least 0.01 % by weight and preferably in a quantity of at least 0.05 % by weight and more preferably in a quantity of at least 0.1 % by weight, based on the pile weight of the carpet.

4. A cut pile carpet as claimed in any of Claims 1 to 3, characterized in that the film-forming polymer is applied in a quantity of at most 10 % by weight, preferably in a quantity of at most 5 % by weight and more preferably in a quantity of at most 1 % by weight, based on the pile weight of the carpet.

5. A process for reducing shading in cut pile carpets, characterized in that

(a) a solution, emulsion or dispersion containing film-forming polymers or prepolymers is applied to the pile fibers by treatment of the carpet, the solvent is evaporated and the treated carpet is optionally heated to harden the polymer or prepolymer or

(b) a solution, emulsion or dispersion containing film-forming polymers or prepolymers is applied to the carpet yarn, the solvent is evaporated and the yarn or the carpet produced therefrom is optionally heated to harden the polymer or prepolymer.

6. A process as claimed in Claim 5, characterized in that the solution, emulsion or dispersion is applied above the backing at the sides of the loops.

7. A process as claimed in Claim 5 or 6, characterized in that the solution, emulsion or dispersion is applied from a concentrated liquor.

8. A process as claimed in any of Claims 5 to 7, characterized in that the solution, emulsion or dispersion is applied as a foam.

9. A process as claimed in one or more of Claims 5 to 8, characterized in that the polymer or prepolymer present in the solution, dispersion or emulsion hardens with enlargement of the molecule after application.

10. A process as claimed in one or more of Claims 5 to 9, characterized in that the polymer or prepolymer is applied in a quantity of at least 0.01 % by weight, preferably in a quantity of at least 0.05 % by weight and more preferably in a quantity of at least 0.1 % by weight, based on the pile weight of the carpet.

11. A process as claimed in one or more of Claims 5 to 10, characterized in that the polymer or prepolymer is applied in a quantity of at most 10 % by weight, preferably in a quantity of at most 5 % by weight and more preferably in a quantity of at most 1 % by weight, based on the pile weight of the carpet.

12. A process as claimed in any of Claims 5 to 11, characterized in that the carpet is treated in piece- dyeing machines.

13. A process as claimed in any of Claims 5 to 12, characterized in that the carpet is treated during dyeing.

14. A carpet yarn for the production of cut pile carpets having a reduced tendency towards shading, characterized in that the carpet yarn is completely or partly coated with a film-forming polymer.

15. A carpet yarn as claimed in Claim 14, characterized in that the film-forming polymer is applied in a quantity of at least 0.01 % by weight, preferably in a quantity of at least 0.05 % by weight and more preferably in a quantity of at least 0.1 % by weight, based on the weight of the yarn.

16. A carpet yarn as claimed in Claim 14 or 15, characterized in that the film-forming polymer is applied in a quantity of at most 10 % by weight, preferably in a quantity of at most 5 % by weight and more preferably in a quantity of at most 1 % by weight, based on the weight of the yarn.

17. The use of solutions, emulsions or dispersions containing film-forming polymers or prepolymers for the treatment of carpets and carpet yarns to reduce shading.