Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-03-14
2003-05-06
Szekely, Peter (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S100000
Reexamination Certificate
active
06559207
ABSTRACT:
TECHNICAL FIELD
This invention relates to flame resistant compositions. More particularly, this invention relates to flame resistant polymer compositions. Even more particularly, this invention relates to flame resistant polymers with a synergistic mixture of flame retardant and compatible additive which allows a lower concentration of flame retardant to be used than would otherwise be effective. The invention further provides a method for rendering polymers flame resistant.
BACKGROUND OF THE INVENTION
Many polymer compositions are not ordinarily flame resistant. In fact, certain polymers, such as polyolefins, can be highly flammable. Imparting flame resistance to polymer compositions can be highly desirable or even required for polymers to be useful in certain applications such as those in the textile field. Various compounds are known to impart flame resistance to polymer compositions.
The use of sterically hindered amines to render polymers flame resistant is well known. Hindered amines have been previously added to polyolefins to impart resistance to the effects of light, heat and oxygen. Certain hindered amines, however, were previously found to be incompatible with some flame retardants and other compounds. Specifically, organohalogenated and organosulfur compounds were found to interfere with the activity of some hindered amines as photostabilizers. A subset of these hindered amines, however, are compatible with such compounds. These hindered amines are known as N-alkoxy (or NOR) substituted hindered amines or NOR hindered amine light stabilizers (NOR HALS). U.S. Pat. No. 5,096,950, for example, discloses the use of NOR substituted hindered amines in conjunction with a polyolefin substrate. Similarly, U.S. Pat. No. 5,393,812 discloses the use of a halogenated hydrocarbyl phosphate and phosphonate ester flame retardant with an alkoxyamine hindered amine to render a polyolefin product flame retardant, light stable, and resistant to fading. It was subsequently determined that N-alkoxy substituted hindered amines function as not only light stabilizers, but also impart flame resistance to polyolefins.
The discovery of the utility of NOR substituted hindered amines as flame retardants provided several benefits including the elimination of certain toxic compounds from flame resistant articles. For example, some halo-organic compounds generate toxic by-products both during production and in the case of combustion of the final product. Additionally, some metal-containing flame retardants such as antimony oxides sometimes contain trace amounts of arsenic compounds.
The use of NOR substituted hindered amines as flame retardants and their structure are well known and are described in PCT Application PCT/US98/13469 (WO99/00450). One useful NOR substituted hindered amine is sold under the tradename CGL-116.
The use of NOR substituted hindered amines as flame retardants generally involves blending the NOR substituted hindered amine with a polymer and, optionally, additional components, followed by melt compounding the mixture into pellets. The polymer can then be processed into fiber, for example, by extruding. While the concentrations at which certain NOR substituted hindered amines are effective as flame retardants are generally lower than those at which brominated flame retardants are effective, it is still desirable to minimize the amount of these compounds used in order to minimize cost. For example, the cost of NOR substituted hindered amines represent a major portion of the cost of producing flame resistant fabrics.
It is also generally desirable to insure that any flame retardant compound used is homogeneously dispersed in the polymer to maximize its effectiveness and insure that excess flame retardant is not required to insure effective incorporation of the flame retardant in all portions of the polymer article. This is particularly important when using flame retardants that do not easily incorporate uniformly into a resin during extrusion.
It is further desirable to be able to add pigments to polymer compositions that do not interfere with the activity of the flame retardant, yielding colored flame retardant compositions. This is particularly desirable in industries such as the automotive fabric industry where colored flame resistant fabrics are currently produced by combining flame resistant fibers and non-flame resistant fibers. When both flame resistant and non-flame resistant fibers are combined in a non-woven fabric, concerns exist over non-homogeneous blending of the two types of fibers. If the blending is not homogeneous, localized areas of the fabric may not have sufficient concentration of flame resistant fibers for the complete article to be flame resistant.
SUMMARY OF INVENTION
It is, therefore, an object of the present invention to provide a flame resistant composition comprising a polymer and a synergistic mixture comprising a non-halogenated flame retardant compound and a compatible additive.
It is another object of the present invention to provide a flame resistant composition wherein a flame retardant compound is homogeneously dispersed through a polymer.
It is still another object of the present invention to provide a flame resistant composition comprising a polymer and a synergistic mixture comprising a non-halogenated N-alkoxy hindered amine and carbon black.
It is yet another object of the present invention to provide a flame retardant compound comprising a non-halogenated flame retardant compound and a pigment that does not interfere with the flame retardant compound.
It is still another object of the present invention to provide a method of rendering a polymer flame resistant comprising compounding a polymer with a synergistic mixture comprising a non-halogenated flame retardant compound and a compatible additive.
It is yet another object of the present invention to provide a method of rendering a polymer flame resistant comprising dispersing a non-halogenated N-alkoxy hindered amine homogeneously through a polymer.
It is still another object of the present invention to provide a method of rendering a polymer flame resistant comprising compounding a polymer with an effective amount of a synergistic mixture comprising a non-halogenated N-alkoxy hindered amine and carbon black.
It is yet another object of the present invention to provide a method of rendering a polymer flame resistant comprising dispersing a non-halogenated flame retardant compound and a pigment that does not interfere with the flame retardant compound.
It is still another object of the present invention to provide a flame resistant fiber comprising a polymer and a synergistic mixture comprising a non-halogenated flame retardant compound and a compatible additive.
It is still another object of the present invention to provide a pigmented flame resistant fiber comprising a polymer, a non-halogenated flame retardant compound, and a pigment that does not interfere with the flame retardant compound.
It is still another object of the present invention to provide a flame resistant fabric comprising a polymer and a synergistic mixture comprising a non-halogenated flame retardant compound and a compatible additive.
It is yet another object of the present invention to provide a pigmented flame resistant fabric comprising a polymer, a non-halogenated flame retardant compound, and a pigment which does not interfere with the flame retardant compound.
At least one or more of the foregoing objects, together with the advantages thereof over the known art relating to the use of flame retardants in polymer compositions, which shall become apparent from the specification which follows, are accomplished by the invention as hereinafter described and claimed.
In general the present invention provides a flame resistant composition comprising(a) a polymer; (b) a synergistic mixture comprising (i) from about 0.6 to about 3 percent of a non-halogenated flame retardant compound; and (ii) at least about 0.06 percent of a compatible additive; wherein said percentages are based on weight percent of (a) plus (b), whe
English Larry
Kirkland Kevin
Tyvand Courtney
Renner Kenner Greive Bobak Taylor & Weber
SI Corporation
Szekely Peter
LandOfFree
Flame resistant polymer composition and method for rendering... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flame resistant polymer composition and method for rendering..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flame resistant polymer composition and method for rendering... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3041244