Stock material or miscellaneous articles – Pile or nap type surface or component – Particular backing structure or composition
Reexamination Certificate
1999-06-11
2001-12-11
Juska, Cheryl (Department: 1771)
Stock material or miscellaneous articles
Pile or nap type surface or component
Particular backing structure or composition
C428S097000, C442S168000
Reexamination Certificate
active
06329039
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to nylon carpets with a polyolefin backing, and especially to such carpets having compositions of ethylene/vinyl acetate copolymers as backing for the nylon fibres. In particular, the invention relates to the stabilization of nylon fibres containing copper stabilizers against degradation effects on the fibres that are caused by those stabilizers in the presence of compositions of ethylene/-vinyl acetate copolymers as backing. Such carpets are particularly intended for use in the manufacture of automotive carpets.
BACKGROUND OF THE INVENTION
In the manufacture of automotive carpets, and other carpets, the back or underside of the carpet is coated with a polyolefin in order to hold the carpet fibres in place and prevent or reduce early abrasive wear and easy removal of tufts of carpet fibres from the carpet. Such a coating is frequently referred to as a pre-coat. In the form of a pre-coat, the polymer wicks into the carpet and forms both mechanical and chemical bonds to the carpet fibres. Thus, the pre-coat functions to retain the fibres in place by such mechanical and chemical bonding to the fibres.
It is understood that the carpet may have additional backing, especially for sound deadening or as backing sheets, all of which may be referred to as “massback”.
A variety of polyolefins are used as pre-coat backing and as a component of sound deadening or backing sheets i.e. “massback”, for automotive carpets.
Problems in the mechanical and chemical bonding of the fibres by the pre-coat have developed as a result of changes in the composition of the fibres in the carpet. Additives containing copper, especially cuprous iodide, are now incorporated into or on the nylon fibres to increase the useful life and retain the colour of the fibre. However, it has been found that in the presence of at least some polyolefin pre-coat or massback compositions, such additives actually cause a degradation reaction that affects the bonding between the fibres and the polyolefin backing. The degradation reaction results in the fibres becoming brittle and crumbling within a short period of time under conditions of heat and sunlight. Such conditions are typical ambient conditions in an automobile in many areas and at many times of the year.
SUMMARY OF THE INVENTION
It has now been found that addition of an additive to the polyolefin backing significantly increases the life of nylon fibres containing copper in carpets, especially automotive carpets, and consequently increases the life of the carpet.
Accordingly, an aspect of the present invention provides a carpet, especially an automotive carpet, comprising nylon fibres and a polyolefin backing that partially envelops said nylon fibres, said nylon fibres having a stabilizer containing copper and said polyolefin backing comprising ethylene/vinyl acetate copolymer and a stabilizing amount of an additive for stabilization of the carpet against copper-induced degradation of the fibre in the presence of such copolymer.
In a preferred embodiment of the automotive carpet, the backing comprises a pre-coat containing ethylene/vinyl acetate copolymer and said additive.
In another embodiment, the backing comprises a pre-coat and a masscoat, said pre-coat or both the pre-coat and masscoat containing ethylene/vinyl acetate copolymer and the additive.
In further embodiments, the additive is 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazine.
Another aspect of the present invention provides a method of manufacture of an automotive carpet having protection against degradation caused by heat and/or light, comprising applying a polyolefin backing to nylon fibres that have a stabilizer containing copper, said polyolefin backing comprising ethylene/vinyl acetate copolymer and an additive for stabilization of nylon fibre against copper-induced degradation of the fibre in the presence of ethylene/vinyl acetate copolymer.
During the manufacture of nylon fibres intended for use in carpets that are likely to be subjected to heat and/or light, it is to be understood that a copper stabilizer e.g. cuprous iodide (CuI), is either added to or coated onto the fibres to act as a stabilizer for the nylon. The nylon may be a variety of types of such polymer, including nylon 6,6, nylon 8 and nylon 12.
The stabilizing effect of the copper stabilizer may be observed when the fibres are exposed to heat and/or UV light. However, it has been found that when a polyolefin backing, especially a pre-coat, formed from an ethylene/vinyl acetate copolymer composition comes in contact with the fibre, the presence of copper ions in the fibre has a de-stabilizing effect on the resultant carpet and causes fibre degradation. While it is believed that both the polyolefin pre-coat and nylon fibres degrade, the effects are most apparent in the fibres. This is indicated by the colour of the pre-coat and the brittleness of the nylon fibres.
Thus, it is the object of an aspect of the present invention to provide a stabilized polyolefin composition comprising ethylene/vinylacetate copolymer that will resist degradation reactions in the fibre that are catalysed by the copper stabilizer in the nylon fibres in the presence of the polyolefin. This reaction is accelerated under conditions of heat and ultra-violet light.
It is understood that the ethylene/vinyl acetate copolymer may be all or part of the polyolefin of the pre-coat or both pre-coat and massback. The polyolefin containing ethylene/vinyl acetate contains the stabilizer that reduces or permits degradation of the nylon of the fibre.
The phenomena can be observed on carpets that have been obtained from cars which have received excessive heat and sunlight, and on carpet samples that have been aged in dry heat or in the presence of Xenon light. It will be noted that the copper stabilizer (CuI) which was added to stabilize the nylon, ultimately promotes carpet degradation and especially promotes fibre degradation.
As exemplified herein, a number of antioxidants such as phenolics and hindered amines were tested but found not to significantly reduce the degradation of the nylon fibres.
It has been found that the addition of metal certain additives, especially de-activators, for instance Irganox™ MD 1024 metal deactivator to polyolefin backings containing ethylene/vinyl acetate copolymers, particularly ethylene/vinyl acetate copolymer carpet pre-coat, reduces degradation of the nylon carpet fibres containing CuI stabilizer.
Thus, it is believed that the copper stabilizer in the nylon fibre is actually promoting degradation of the fibre it is intended to protect, when ethylene/vinyl acetate copolymer is used in the backing.
Irganox MD 1024 metal deactivator is 1,2-bis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamoyl)hydrazine, and the chemical structure is given in FIG.
1
.
This type of additive is commonly referred to as a metal de-activator, of which Irganox MD 1024 metal deactivator is one example. Other metal deactivators may be used but 1,2-bis(3,5-di-tert-butyl-4-hydroxyhydro-cinnamoyl)hydrazine i.e. Irganoz MD 1024, is preferred.
A preferred additive level is from 500 ppm to 1000 ppm, although other levels may also be used.
The present invention provides carpet comprising copper-stabilized nylon fibres and polyolefin backing ethylene/vinyl acetate copolymer with improved stability against degradation. While the invention is particularly directed to automotive carpet, it also relates to other carpets that might be subjected to heat and/or ultraviolet light. subjected to heat and/or ultraviolet light.
REFERENCES:
patent: 4455204 (1984-06-01), Pieslak et al.
patent: 5216054 (1993-06-01), Iwanami et al.
patent: 5945469 (1999-08-01), Heath et al.
patent: 610 155 (1994-08-01), None
JPO English abstract of JP 05-70016, (Oct. 1994).*
Derwent English abstact of JP 05-2927, (Jan. 1993).*
Derwent English abstract of DD 231 947, (Jan. 1996).*
Textiletech abstact of G. Reinhart, “Photostability of Polyamide Fibers,” Colourage, Annual 1990-1991: 41-48 (1990).*
“Stabilization of Polyolefins in Contact With Cop
AT Plastics Inc
Juska Cheryl
Sheridan & Ross P.C.
LandOfFree
Polyolefin-backed nylon carpets with improved stability does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polyolefin-backed nylon carpets with improved stability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polyolefin-backed nylon carpets with improved stability will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2571190