CA1065240A - Artificial fibers preparation - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An article of manufacture comprising a plurality of fibers partially embedded in a solidified plasticized sulfur matrix with one end of the fibers extending outward from the matrix to form a turf or carpet-like surface. By the process of embedding, the steps of cementing or providing a backing with cementing are obviated, thus yielding a simpler made article than conventional materials of the broad class.

Description

~065Z40 BACKGROUND OF T~E INV~NTION

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The present invention relates to a synthetic turf or carpet-like manufacture comprising a plasticized sulfur i matrix.
Prior patents disclosing synthetic turfs include U.S. Patents 3,422,615; 3,332,828; 3,157,557; 2,515,~47;

2,061,750; and 1,939,846.
U.S. Patent 3,422,615 discloses a synthetic turf-like material which i5 referred to as a pile fabric. Fibers which are indicated as being suitable for making the yarns used to make the pile fabric of USP 3,422,615 are said to include olefins, particularly polypropylene, nylon, vinyl, vinylidene chloride, polyvinyl chloride, polyethylene, polyester, polyacrylonitrile, acetate, triacetate, rayon (cellulosics), and glass.
U.S. Patent 3,332,828 relates to artificial turf preferably produced by weaving synthetic fibers on a Wilton cut-pile loom to form a structure consisting of a woven backing having a cut-pile face extending from one surface thereof and then applying a suitable latex formation on the other surface of the backing to render the complete ~tructure dimensionally stable.
U.S. Patent 3,157,557 discloses an integrally molded plastic sod simulating natural grass and comprising a flat flexible base of a thick plastic material having a multiplicity of closely-spaced blade-like plastic stems molded integral with the base.
U.S. Patent 2,515,847 discloses a surfacing structure suitable for use as a putting green for golf. The surfacing structure includes a top layer of rug material having a nap.

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~065Z40 The rug ~aterial is supported on center layers of sponge rubber-like material. The supported rug material is placed upon the earth.
United States Patent 2,061,750 relates to grass mats prepared by stitching grass simulated material to a base.
United States Patent 1,939,846 discloses distributing - : -, :
fibrous material evenly over the top of a sheet of rubber composi-tion and then vulcanizing the fibers to the sheet in a heat press.
Plasticized sulfur has been disclosed in various references, for example by J. I. Jin in "Chemistry of Plastic-ized Sulfur", Petroleum Division, A. C. S. Symposium, Vol. 19, No. 2, March 1974, pp. 234-241 and by C. Kinney Hancock in "Plasticized Sulfur Compositions for Traffic Marking", Industrial and Engineering Chemistry, Vol. 46, No. 11, November 1954, pp. 2431-2435. Exemplary patents disclosing plasticized sulfur include USP 3,316,115 "Marking Compositions"; USP 3,434,852 "Plasticized Sulfur Compositions"; USP 3,447,941, "Sprayable ; Sulfur Road Marking Compositions"; USP 3,459,717 "Sulfur Based Plastic Composition"; USP 3,560,451 "Plastic and Nonflammable Sulfur Composition"; USP 3,453,125 "Plasticized Sulfur Compositions";
; USP 3,674,525 "Plasticized Sulfur Compositions"; and USP 3,676,166 "Plasticized Sulfur Compositions". Also United States Patent

3,823,019, which has been offered for license by the United States Bureau of Mines, discloses plasticized sulfur compositions.
According to the present invention a manufacture is provided comprising a plurality of fibers partially embedded in a solidified plasticized sulfur matrix with one end of the fibers extending outward from the matrix to form a turf or carpet-like i~ surface.
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_ 3 _ ~)65Z40 According to a preferred embodiment of the present invention the sulfur is plasticized with dicyclopentadiene, aliphatic polysulfide, aromatic polysulfide, or mixtures thereof.
The term "fiber" is used herein to include mono-filament strands as well as polyfilament strands (yarns and threads and yarns made by twisting a fibrillated thermoplastic tape). Preferably yarn is used to form the product of the present invention. The yarn can be produced by twisting filaments together by methods known in the carpet-producing art. In this regard, see, for example, U.S. Patent 3,422,615.
Materials which can be used as the monofilament strands or as the polyfilament strands, that is~ yarns, include synthetic plastic materials as well as animal-derived materials'such as wool. Preferably, synthetic materials are used, i.e., synthetic plastic materials capable of being formed into filaments and yarns, for example by extruding into a pellicle and then cut or shredded into filaments which can in turn be converted to yarns. Polypropylene is a particularly preferred synthetic "20 plastic material for forming fibers for use herein, and a particularly preferred polypropylene yarn is made by twisting fibrillated polypropylene tapes. Other materials which can be used include other polyolefins, polyethylene terephthalate, polyacrylonitrile, viscose rayon, cellulose acetate, nylon, polyvinyl chloride, and fibrous glass.
In addition to U.S. Patent 3,422,615, U.S. Patents 3,177,557, 3,242,035 and 3,332,828 disclose materials which can be used to produce monofilament strands as well as poly-filament strands (yarns) for making artificial turf.

Among other factors the present invention is based on my finding of the surprisingly advantageous adherence of - ~ - .

1()65Z40 solidified plasticized sulfur to fibers, especially fibcrs such as polypropylene, and especially polypropylene in the form of pieces of yarn. ~lso the combination product of the present invention has been found to poss~ss particularly attractive durability and serviceability characteristics so that it can advantageously be used in surfaces subjected to abusive foot traffic.
Plasticized sulfur as the term is used herein usually has a lower melting point and a higher viscosity than elemental sulfur. Furthermore, plasticized sulfur requires a longer time to crys~allize; i.e., the rate of crystallization of plasticized sulfur is slower than that - of elemental sulfur. One useful way to measure the rate of crystallization is as follows: the test material (0.040 g) is melted on a microscope slide at 130C. and is then covered with a square microscope slide cover slip. The slide is transferred to a hot-plate and is kept at a temperature of 78+2C., as measured on the glass slide using a surface pyrometer. One corner of the melt is seeded with a crystal of test material. The time required ~or complete crystal-lization is measured. Plasticized sulfur, then, ic sulfur containing an additive which increases the crystallization time within experimental error, i.e., the average crystalli-zation time of the plasticized sulfur is greater than the average crystallization time of the elemental sulfur feedstock.
For the present application, plasticizers are those substances which, when added to molten, elemental sulfur, cause an increase in crystallization time in reference to the elemental sulfur itself. ~n one set of experiments, elemental sulfur required 0.44 minute to crystallize under the above conditions, whereas sulfur containing 3.8% of a phenol-sulfur adduct (as described - . .

~65Z40 in United States Patent 3,892,686) required 2.9 minutes. Sulfur containing 6.6% and 9.9% of the same phenol-sulfur adduct required 5.7 and 22 minutes, respectively.
Inorganic plasticizers include iron, arsenic and phosphorus sulfides, but the particularly preferred plasticizers are organic compounds which can react with sulfur to give sulfur-containing materials, such as styrene, alphamethylstyrene, dicyclopentadiene, vinyl cyclohexene, the aromatic compound-sulfur adducts of United States Patent 3,892,686 as well as the aromatic compounds used to produce these adducts, aromatic or ali-phatic liquid polysulfides (e.g., those sold under the trade mark of ThiokolLP-3 or LP-32), and the viscosity control agents described in United States ~- Patents 3,674,525, 3,453,125 and 3,676,166. The preferred aromatic plastic-izing compounds are styrene and the phenol-sulfur adduct of the aforesaid United States Patent 3,892,686. The preferred aliphatic compound is dicyclopentadiene.
One preferred plasticized sulfur substance contains dicyclo-pentadiene, sulfur, glass fiber and talc.
The elemental sulfur may be either crystalline or amorphous and may contain small amounts of impurities such as those normally found in commercial grades of sulfur. Optimum proportions of sulfur, as well as of the other components of the composition may vary considerably. However, proportions of sulfur of about 73 to 97%, by weight, are generally satisfact-ory~
; Dicyclopentadiene is readily available commercially, gener-ally at a purity of about 96% or greater. Preferably it is used in the above preferred plasticized sulfur composition in an amount of about 1 to 7% by ;~
weight.
The glass fiber of the preferred plasticized sulfur compo-. . .
sition is preferably employed in the form of milled fibers, with the fibers generally ranging from about 1/32 to 1/4" in `~4 .
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1~5Z40 length, preferably with an average length of about l/16".
These fibers, which generally consist of high-silica glass, are readily available co~nercially, often coated with a starch binder. The type of glass is, however, not critical, as long as it provides the resulting composition with adequate shear strength, preferably a shear strength of about 400 to 800 psi.
The glass fiber preferably constitutes about l to 5% by weight of the composition of the invention.
The talc used in the preferred dicyclopentadiene-lQ sulfur-glass fiber-talc composition prefera~ly is a foliated type, or a compact variety such as steatite. Impure varieties such as soapstone can also be used. This ingredient is preferably used in an amount of about l to 15~ by weight of the composition, and serves the dual function of providing thixotropy to the mixture and of dispersing the glass fiber throughout the composition, thereby preventing agglomeration of the fibers.
The preferred composition is used as a fluid mixture of the ingredients, with the sulfur and dicyclopentadiene in molten form and the glass fiber and talc distributed throughout the molten material. Thus the composition is prepared by homogeneous mixing of the ingredients at elevated temperature sufficient to maintain the sulfur and dicyclopentadiene in a molten state. A temperature of about 240 to 320~. is satisfactory, with about 275 to 320F. being preferred. Any conventional vessel or reactor capable of providing the required temperature and mixing means may be used for preparation of the composition.
DRAWING
The drawing is a schematic illustration of an embodiment of the present invention. As shown in the drawing the plasticized sulfur rests on the soil or floor, and yarns or 1~65Z40 fibers are embedded into the plasticized sulfur. The thickness of the plasticized sulfur can vary but typically is between abou~ 1/4" to 3", more usually between about 1/2" and 2" thick. One advantage in preparing the product of the present invention is that it can be prepared for outdoor applications on the site as well as being capable of being prepared in modules or sections in a plant. Usually the product is prepared by im-mersing or embedding fibers in the molten plasticized sulfur and then - removing a backing or o~her means which might be used to hold the fibers or yarn elements in place when they are embedded in the molten plasticized sulfur and during the solidification of the plasticized sulfur. Means for implanting fibers into molten plasticized sulfur are also discussed in my joint inventorship and commonly assigned United States Patent 3,944,452.
EXAMPLES
Example 1 -- Plasticized Sulfur Mastic as a Carpet Base A plasticized sulfur mastic was prepared by heating a mixture of 3 parts of dicyclopentadiene and 100 parts of molten sulfur until there was a noticeable increase in viscosity. Next, 10 parts of talc and 3 parts of glass fiber (milled to 1/8" lengths) were added and the .;.
whole mixture was stirred until it was homogenous. This material was then ; 20 poured onto a flat 12" x 18" area of ground covered with small-sized gravel to a depth of 3/8". Before the sulfur mastic hardened, a sheared or cut-pile indoor-outdoor carpet, made by tufting polypropylene yarn into a polypropylene primary backing and without any latex or other secondary backing, was laid on the mastic. When the mastic had hardened, a corner of the backing -: ~

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1~65Z40 was pried loose, and then the entire backing was pulled upward, through the cut piles, leaving the tufts securely anchored in the smooth, hard mastic surface. The finished installation had the appearance of a grassy lawn.
One unexpected beneficial advantage of thc product was the excellent adherence and retention of the polypropylene fibers or yarn by the plasticized sulfur.
~xample 2--Non-Plasticized Sulfur ~lastic as a Carpet Base (a) A small (4" x 4") piece of polypropylene tufted o indoor-outdoor carpet was immersed upside down (about 1/4") into a molten sulfur-glass fiber mixture 1/2" deep. When the sulfur had hardened, the carpet backing was cut off, leaving a grass-like structure held in place by the solidified sulfur-glass fiber mixture.
(b) The same experiment was repeated except that the glass fibers were replaced by sand. The results were the same.
The above experiment indicates that sulfur, with or without an added material such as talc or sand or glass fiber, can be used in the present invention instead of plasticized . 2d sulfur. However, my other experimental work indicates that plasticized sulfur performs better in the present invention.

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Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An article of manufacture comprising a plurality of fibers partially embedded in a solidified plasticized sulfur matrix with one end of the fibers extending outward from the matrix to form a turf or carpet-like surface.

2. An article of manufacture in accordance with claim 1 wherein the sulfur is plasticized with dicyclopentadiene, aliphatic polysulfide, aromatic polysulfides, or mixtures thereof.

3. An article of manufacture in accordance with claim 1 wherein the fibers are wool, cotton, nylon, polypropylene, polyethylene, polyurethane, or mixtures thereof.

4. An article of manufacture in accordance with claim 1 wherein the fibers are polypropylene.

5. An article of manufacture in accordance with claim 1 wherein the plasticized sulfur comprises, by weight, about 73 to 97%
sulfur, about 1 to 7% dicyclopentadiene, about 1 to 5% glass fiber, and about 1 to 15% talc.