AU627697B2 - Root-growth-inhibiting sheet - Google Patents

Description

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WORLD INTELLECTUAL PROPERTY ORGANIZATION International Bureau INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 89/ 01284 A01G 13/02 Al (43) International Publication Date: 23 February 1989 (23.02.89) (21) International Application Number: PCT/US88/02853 (74) Agents: SHAWEKER, Kenneth, E. et al.; Battelle Memorial Institute, 505 King Avenue, Columbus, OH (22) International Filing Date: 18 August 1988 (18.08.88) 43201-2693 (US).

(31) Priority Application Number: 086,757 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (Euro- (32) Priority Date: 18 August 1987 (18.08.87) pean patent), FR (European patent), GB (European patent), IT (European patent), JP, LU (European pa- (33) Priority Country: US tent), NL (European patent), SE (European patent).

(71) Applicant: BATTELLE MEMORIAL INSTITUTE Published [US/US]; 505 King Avenue, Columbus, OH With international search report.

43201-2693 Before the expiration of the time limit for amending the claims and to be republished in the event of the receipt (72) Inventors: BURTON, Frederick, G. 6490 King Pike, of amendments.

West Jefferson, OH 43162 CATALDO, Dominic, A. 908 South Nelson Street, Kennewick, WA A 99336 CLINE, John, F. Route 3, Box 3190, A.O.J.P. 27 APR 1989 Prosser, WA 99350 SKIENS, Eugene 7120 Arbor Lake Drive, Wilsonville, OR, 97070 VAN VORIS, Peter 2306 Inverness Court, Richland, WA 99352

AUSTRALIAN

9 MAR 1989 PATENT OFFICE (54) Title: ROOT-GROWTH-INHIBITING SHEET ~'a (57) Abstract A sheet material is disclosed which can be buried in the soil to prevent the entry of roots into unwanted regions.

The sheet is a water-permeable material which holds a plurality of polymer bodies containing an effective ingredient of 2,6-dinitroaniline. The effective ingredient slowly diffuses from the polymer into the soil adjacent the sheet material to prevent the root growth over time.

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WO 89/01284 PCT/US88/02853 -1- ROOT-GROWTH-INHIBITING SHEET Introduction U.S. Patent applications Serial Number 555,113 filed November 23, 1983 and Serial Numbers 314,809 and 314,810, both filed October 26, 1981 disclose method and articles for the inhibition of root growth, particularly the exclusion of the roots from areas in which they are undesirable, waste burial sites, underground pipelines, basements, sidewalks, or simply the boundaries between adjacent properties. The articles are formed of polymers, polyethylene, contain in admixture dinitroanilines, preferably N,N-di-n-propyl-4 trifluoromethyl 2,6-dinitroaniline having the generic name trifluralin. Among the articles which are disclosed are pellets of cylindrical form, about 9 mm in diameter and the same in length. These pellets are preferably distributed about 1 or 2 inches apart over the area which it is desired to protect. These pellets containing about 25 percent by weight of trifluralin have proven very satisfactory in use and have been shown by tests to have a probable effective life of 50 to over 100 years. Their disadvantage lies in the fact that to distribute them uniformly is a slow, laborious operation.

Summary of the Invention In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or nonwoven textile material. A particularly desirable embodiment is a nonwoven fabric of non-biodegradable material. This type of material is known as a "geotextile" and is used for weed control, WO 89/01284 PCT/US88/02853 -2prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

The polymer containing the root repellent dinitroaniline may be distributed in various forms, as buttons or as, continuous other elongated beads. The choice of the specific mode of distribution depends to a large part on the life desired for the root repellency.

The effectiveness of the porous sheet barrier in inhibiting root elongation is controlled by the soil concentration of dinitroaniline adjacent to the barrier.

This is regulated by the release rate of the dinitroaniline from the buttons, or beads. For buttons, spacing is generally on 1- to 2-inch centers. Elongated beads are arranged in regular patterns or spacing to produce a protective soil area. The dinitroaniline will slowly diffuse from the polymer with which it is mixed at a controlled rate, be absorbed to the soil adjacent to the barrier, and thus prevent further elongation or penetration of the roots.

Brief Description of the Drawings In the drawings Figure 1 is a perspective view of the embodiment employing small buttons of polymer.

Figure 2 is a cross section on the line 2-2 of Figure i. Figure 3 is a plan view of the type employing continuous beads. Figure 4 is a section on the line 4-4 of Figure 3D Detailed Description In Figure 1 we have shown a sheet of nonwoven fabric formed of felted fibers of polyethylene or other thermoplastic material. Attached to it are buttons !i

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I I WO 89/01284 PCT/US88/02853 of polymer in which is mixed from 2 to 30 dinitroaniline, preferably trifluralin. Carbon black is usually added to improve retention of the dinitroaniline. The buttons may be made from a polymer selected from the following list: Polyethylenes (low density, linear low density, high density) Polypropylene Copolymers and blends of above polymers Ethylene vinylacetate/ethylene acrylic acid/ethylene ethyl acrylate Polybutylene Acrylate-styrene-acrylonitrile Epoxies Polyamides Polyesters (aromatic) Polyurethanes Silicones Thermoplastic elastomers which may be prepared from a number of monomers such as styrene block copolymers with butadiene or isoprene, polyether-esters or olefinics.

The buttons, 4, are attached to the sheet, 2, by adhesives or mechanical fasteners. A particularly desirable mode is by extrusion of a molten plastic mixed with the dinitroaniline onto or through the fabric and allowing it to cool in place. Desirably the buttons have an average diameter of 1/4 to 3/8 inch and an average thickness of 1/8 to 3/8 inch and spaced on 1 to 3 inch centers, preferably not more than 2 inches. As stated above, they should contain from 2 to 30 percent dinitroaniline. Based on experimental results, buttons of the 3/8-inch diameter and 3/8-inch thickness containing percent trifluralin and 25 percent carbon black will have an effective root repelling lifetime of at least 50 years and probably 100 years. Buttons of other sizes i i iS WO 89/01284 PCT/US88/02853 4 made of different polymers and/or containing different dinitroanilines will have different lives which may be varied according to the intended use. As may be expected, the use of smaller buttons and the use of smaller proportions of dinitroaniline will result in shorter lives, as will the use of dinitroanilines which diffuse more rapidly than trifluralin.

While we have shown the buttons arranged in right angled rows, other distributions, in a diamond i:O pattern, may be preferred in some cases.

In Figures 3 and 4 we show the use of elongated beads, 8, attached to the fabric 6. These beads may be formed of the same materials and attached in the same manner as the buttons, 4, of Figures 1 and 2.

They may have widths and thicknesses in the range of 1/16 to 1/4 inch and should not leave gaps of more than 2 inches. Because they have a stiffening effect on the fabric, this embodiment is somewhat less flexible in use than the one having buttons shown in Figures 1 and 2. The beads need not be parallel, but may be arranged in other patterns.

While we have described certain embodiments in detail, it will be obvious to those skilled in the art that various changes can be made. We therefore wish our invention to be limited solely by the scope of the. appended claims.

Claims (14)

1. A material for preventing the entry of roots into unwanted areas comprising a sheet of water-permeable material; characterised in that the sheet material carries distributed bodies of a polymer blended with from 2 to 30 percent of a 2,6-dinitroaniline; wherein the dinitroaniline is released slowly from the distributed bodies by diffusion from the polymer into the soil juxtaposed the material, thereby to prevent elongation or penetration of the roots into the soil around the material.

2. A material as defined in claim 1 wherein said dinitroaniline is trifluralin.

3. A material as defined in claim 1 or claim 2 wherein said sheet is flexible.

4. A material as defined in any preceding claim wherein said sheet is formed of a non-biodegradable composition.

A material as defined in any preceding claim wherein said sheet is a nonwoven fabric of a non-biodegradable polymeric composition.

6. A material as defined in any preceding claim wherein said polymer is blended further with an amount of carbon black sufficient to improve retention of said dinitroaniline.

7. A material as claimed in claim 6 wherein the concentration of carbon black is about 25 percent.

8. A material as defined in any preceding claim wherein said polymer is polyethylene.

9. A material as defined in any preceding claim wherein said polymer is in the form of buttons attached to, and distributed over, said sheet.

A material as defined in claim 9, wherein said buttons are 6.3 to 9.45mm (1/4 to 3/8 inch) in diameter and 3.15 to 9.45mm (1/8 to 3/8 inch) maximum thickness.

11. Material as defined in claim 9 or 10 wherein said buttons to 3 inc

12. An wherein 5

13. An are 0.15 to 6.3mn

14. An unwantec 10 with ref Descript DATED t i a. a. r 7 i I 6 buttons are spaced apart an average of 2.52 to 7.56 cms (1 to 3 inches). 12. A material as defined in any one of claims 1 to 8 wherein said polymer is in the form of elongated beads. 13. A material as defined in claim 12 wherein said beads are 0.158 to 0.63 cm (1/16 to 1/4 inch) wide and from 1.57 to 6.3mms (1/16 to 1/4 inch) in maximum thickness. 14. A material for preventing the entry of roots into unwanted areas substantially as hereinbefore described with reference to the description entitled "Detailed Description". DATED this 16 day of June 1992 BATTELLE MEMORIAL INSTITUTE Patent Attorneys for the Applicant: F.B. RICE CO. a e e *s