Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
1998-11-10
2001-04-03
Michl, Paul R. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
active
06211275
ABSTRACT:
FIELD OF THE INVENTION
Broadly, the present invention relates to a composition that can serve as a wood substitute in numerous applications where wood is used, and methods of producing a wood substitute using discarded materials.
BACKGROUND OF THE INVENTION
Presently, carpet is used routinely in residential, commercial, industrial, and automobile settings. Although many types of styles and colors are available, the face fibers of carpets produced in North America are predominantly comprised of nylon 6, produced by Allied-Signal Corporation, or nylon 6,6 produced by Solutia Corporation. In addition to the face fiber, which is about 50% by weight of a carpet, a typical broadloom carpet also contains about 10% by weight polypropylene primary and secondary backings, about 9% by weight styrene-butadiene rubber (SBR) latex adhesive, and about 35% by weight calcium carbonate as filler. The construction of a typical broadloom carpet involves weaving the face fiber through the primary polypropylene backing forming a “U” shaped fiber such that the ends of the face fiber form the pile of the carpet, i.e., the surface of the carpet, and the base of the “U” shaped fiber is located beneath the primary polypropylene backing. A layer of a composition comprising the SBR latex adhesive and calcium carbonate filler is then applied to the surface of the primary polypropylene backing opposite of the pile such that the base of the “U” shaped fiber is embedded in the composition. A secondary backing made of polypropylene is then adhered to the layer comprising SBR latex adhesive and calcium carbonate opposite to the pile. A schematical cross sectional view of a typical broadloom carpet is set forth in FIG.
1
.
In order to produce the huge amounts of carpet consumed by the construction industry, and to replace worn carpet, billions of pounds of fibers are produced. For example, in 1995, Canada and the United States produced 3.1 billion pounds of fiber for carpets. With these fibers, approximately 6.4 billion pounds of carpet were produced, of which about 70% was used to replace worn carpet. In order to decrease the amount of landfill volume used by disposed carpet, and to recycle valuable components of carpet, such as the face fibers, efforts have been made to isolate and depolymerize nylon 6 face fibers from carpet. A particular example of such a method is set forth in U.S. Pat. No. 5,457,197 (the '197 patent) and U.S. Pat. No. 5,681,952 (the '952 patent), both of which are hereby incorporated by the reference herein in their entireties. The '197 patent discloses a process for recovering monomer from a multi-component polymeric waste material, such as carpet, that includes at least one hydrolyzable polymeric component, e.g., the nylon 6 pile. As a result of the processes set forth in these patents, nylon 6 fibers can be removed from a multicomponent carpet and depolymerized to form caprolactam, while the remaining components of the carpet form a calcium carbonate and thermoplastic resin blend referred to as “Q compound”. Q compound is a black, brittle solid made up of non-nylon 6 components of carpet produced with the processes of the '197 and '952 patents. In particular, Q compound comprises by weight about 63-65% calcium carbonate, about 15-18% polypropylene, and about 12-15% styrene butadiene rubber. Since carpets processed pursuant to the teachings of the '197 and '952 patents are generally constructed in the same manner with the same materials, the Q compound produced using these processes generally has the same composition and physical properties. Table 1 sets forth ranges and average of the calorific value, and amounts of sulfur and chloride found in Q compound.
TABLE 1
Range and Average Parameters regarding properties of Q Compound
Parameter
Measuring Method
Range
Average
BTU/lb
ASTM D-2015-85
6660-6914
6818
% Sulfur
ASTM D-3177
0.19-0.30
0.24
% Chloride
ASTM C-114
0.05-0.09
0.07
Furthermore, a Material Safety Data Sheet describing the properties of Q compound is incorporated by reference herein, and attached hereto as “Appendix A”.
Since tons of nylon 6 are being reclaimed and recycled every year, tons of Q compound are being produced with no apparent use. Accordingly, what is needed is a use for Q compound so that all the components of discarded carpet can be recycled, thus alleviating the strain on available landfills.
The citation of any reference herein should not be construed as an admission that such reference is available as “Prior Art” to the instant application.
SUMMARY OF THE INVENTION
There is provided, in accordance with the present invention, a composition that can serve as a wood substitute. wherein processes for forming the composition utilize Q compound produced in the reclamation of nylon 6 from discarded carpet. A composition of the present invention has numerous applications in the construction industry, including, but not limited to thermal spacers in metal studs used in framing structures.
Broadly, the present invention extends to a wood substitute composition comprising a polyolefin and a composition comprising calcium carbonate, polypropylene, and styrene butadiene rubber. The amount by weight of polyolefin in the wood substitute composition can vary from about 10% to about 90% by weight, depending upon the desired molding properties of the wood substitute composition. Likewise, the amount of the composition described above included within the wood substitute composition can vary from about 10% to about 90% by weight. The greater the quantity of polyolefin included in a wood substitute composition of the invention, the less rigid the wood substitute composition becomes, and the easier it is for a skilled artisan to mold the wood substitute composition. Also, increasing the amount of the composition set forth above in the wood substitute composition of the invention results in increasing the rigidity of the wood substitute composition. Hence a skilled artisan can readily produce a wood substitute composition of the invention having properties needed for a particular application. In a particular embodiment of the invention, a wood substitute composition comprises by weight about 20% polyolefin, and about 80% of the composition set forth above.
Furthermore, the present invention extends to a wood substitute as explained above, wherein the polyolefin and the composition comprising calcium carbonate, polypropylene, and styrene butadiene rubber are mixed and heated to a sufficient temperature for a sufficient length of time to form a fluid. This fluid is then optionally molded and then cooled in order to form a solid, which is a wood substitute composition of the invention. Numerous temperatures can serve as a sufficient temperature for purposes of producing a wood substitute composition of the invention. For example, a temperature sufficient to form a fluid as described above can range from about 100° to about 230° C., depending upon the amount of polyolefin and composition in the wood substitute composition. In a particular embodiment of the invention, the polyolefin comprises low density polyethylene (LDPE) which is 20% by weight of the wood substitute composition, and the composition described above comprises about 80% by weight. A sufficient temperature to form a fluid for this mixture is about 225° C.
Furthermore, as explained above, a mixture of the composition described above and the polyolefin must be heated for a sufficient length of time in order to form a fluid. Naturally, the sufficient length of time depends upon the temperature to which the mixture is heated. Hence, the sufficient period of time can range from about 3 minutes to about 10 minutes. In a particular embodiment, wherein the polyolefin is LDPE and comprises about 20% by weight of the wood substitute composition, and the composition comprises about 80% by weight. The polyolefin and composition are mixed and heated to about 225° C. for about 5 minutes. Moreover, heating and mixing of the polyolefin and the composition can occur simultaneously.
In addition, numerou
Dey Subir K.
Xanthos Marino
Klauber & Jackson
Michl Paul R.
New Jersey Institute of Technology
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