# US 5,347,753 A · Degradation resistant molded pulp horticultural container > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,347,753 A - Document ID: US5347753A - Status: Granted - Kind: A - Application number: 07/773,346 - Filed: 1991-10-07 - Granted: 1994-09-20 - Earliest claimed: 1991-02-08 - Assignees: Keyes Fiber Co. - Inventors: Paul E. Dall - Web page: https://patentgrep.com/patent/US5347753A ## CPC - A01G 9/029: Receptacles for seedlings (growth substrates in block form A01G24/44) - A01G: HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING (picking of fruits, vegetables, hops or the like A01D46/00; propagating unicellular algae C12N1/12) ## Abstract A horticultural container is disclosed which is composed of molded pulp fiber and which contains an organic thiocyanate microbicide, the container being resistant to degradation when exposed to soil burial or greenhouse conditions. ## Claims ### Claim 1 A horticultural container composed of molded pulp formed from an aqueous pulp fiber dispersion and containing dispersed within the molded pulp an effective amount of an organic thiocyanate selected from S-thiocyanomethyl compounds of 2-mercaptobenzothiazoles, 2-mercaptobenzoxazoles, or 2-mercaptobenzimidazoles, the organic thiocyanate being provided in the aqueous pulp fiber dispersion and retained in the molded pulp container during formation to control the degradation of said container. ### Claim 2 (depends on 1) The container of claim 1 wherein the organic thiocyanate is 2-(thiocyanomethylthio) benzothiazole. ### Claim 3 (depends on 2) The container of claim 2 containing between 450 and 3000 ppm of the organic thiocyanate. ### Claim 4 (depends on 3) The container of claim 3 containing between 450 and 2000 ppm of the organic thiocyanate. ### Claim 5 (depends on 2) The container of claim 2 additionally containing a sizing. ### Claim 6 (depends on 2) The container of claim 2 additionally containing a retention aid. ### Claim 7 (depends on 6) The container of claim 6 wherein the retention aid is alum. ### Claim 8 (depends on 2) The container of claim 2 additionally containing a wet-strength resin. ### Claim 9 (depends on 2) The container of claim 2 wherein the wall thickness of the container is between 0.03 and 0.1 inches. ### Claim 10 (depends on 1) The container of claim 1 wherein the molded pulp includes low bond strength fibers to facilitate root-penetrability. ### Claim 11 (depends on 5) The container of claim 5, containing less than 5% by weight asphalt as sizing. ### Claim 12 (depends on 1) The container of claim 1, wherein the container is asphalt-free. ### Claim 13 (depends on 1) The container of claim 1, wherein the container is provided with root-penetrable openings. ### Claim 14 (depends on 2) The container of claim 2, wherein the container is provided with root-penetrable openings. ### Claim 15 A plant propogation tray consisting of a plurality of individual cells, the plant propogation tray being composed of molded pulp fiber formed from an aqueous pulp fiber dispersion and containing dispersed within the molded fiber an effective amount of an organic thiocyanate selected from S-thiocyanomethyl compounds of 2-mercaptobenzothiazoles, 2-mercaptobenzoxazoles, or 2-mercaptobenzimidazoles, the organic thiocyanate being provided in the aqueous pulp fiber dispersion and retained in the molded pulp tray during formation to control the degradation of said container. ### Claim 16 (depends on 15) The plant propogation tray of claim 15 wherein the organic thiocyanate is 2-(thiocyanomethylthio) benzothiazole. ### Claim 17 (depends on 16) The plant propogation tray of claim 16, containing 450-3000 ppm of organic thiocyanate. ### Claim 18 (depends on 16) The plant propogation tray of claim 16 additionally containing a sizing. ### Claim 19 (depends on 16) The plant propogation tray of claim 16 additionally containing a retention aid. ### Claim 20 (depends on 16) The plant propogation tray of claim 16, wherein the tray is asphalt-free. ### Claim 21 (depends on 16) The plant propogation tray of claim 16, wherein the tray is peat-free. ### Claim 22 (depends on 16) The plant propogation tray of claim 16, wherein the molded pulp includes low bond strength fibers to facilitate root-penetrability. ### Claim 23 (depends on 16) The plant propogation tray of claim 16, wherein each cell is provided with at least one root-penetrable opening. ### Claim 24 (depends on 16) The plant propogation tray of claim 16, additionally containing a wet-strength resin. ### Claim 25 A process for preparing a molded pulp horticultural container which is resistant to microbial degradation, comprising: a) providing an aqueous fiber dispersion; b) combining and admixing with the fiber dispersion a dispersion of an organic thiocyanate to form a dispersion mixture, the organic thiocyanate being selected from S-thiocyanomethyl compounds of 2-mercapto-benzothiazoles, 2-mercaptobenzoxazoles, or 2-mercaptobenzimidazoles; and c) forming the dispersion mixture into a molded container, the organic thiocyanate controlling the degradation of said container. ### Claim 26 (depends on 26) The process of claim 26 wherein from 6 to 40 pounds of a 30% dispersion of organic thiocyanate are added per ton of fiber dispersion in forming the dispersion mixture. ### Claim 27 (depends on 25) The process of claim 25, wherein the dispersion mixture contains alum. ### Claim 28 (depends on 27) The process of claim 27, wherein the alum comprises 2% to 4% by weight of the dispersion mixture. ### Claim 29 (depends on 25) The process of claim 25 wherein the organic isothiocyanate is 2-(thiocyanomethylthio) benzothiazole. ### Claim 30 (depends on 25) The process of claim 25, wherein the dispersion mixture contains a retention aid. ### Claim 31 (depends on 24) A horticultural container produced by the process of claim 24. ### Claim 32 (depends on 28) A horticultural container produced by the process of claim 28.