Compostable wet-laid articles comprising cellulose and cellulose esters

Abstract

Wet laid products including packaging is obtained from co-refined cellulose fibers and synthetic fibers are made biodegradable, and can also be compostable and soil biodegradable. The synthetic fibers include staple cellulose ester fibers. Desirably, such staple cellulose ester fibers have a denier per filament of 3 or less, a cut length of 6 mm or less, are crimped, or are non-round and crimped, and have a degree of substitution of 2.5 or less.

What we claim is: 
     
         1 . A wet laid product comprising:
 a. virgin cellulose fibers, waste/recycle cellulose fibers, or a combination of both, and   b. cellulose ester (CE) staple fibers having:
 i. a denier per filament (DPF) of less than 3, 
 ii. a cut length of less than 6 mm, 
 iii. crimping, 
 iv. or a combination of any two or more of (i)-(iii), 
   wherein said wet laid product is biodegradable, and optionally compostable.   
     
     
         2 . The wet laid product of  claim 1 , wherein the wet laid product, package, or packing article contains or is obtained from a composition containing co-refined cellulose fibers and CE staple fibers. 
     
     
         3 . The wet laid product of  claim 1 , wherein the wet laid product, package, or packing article comprises office paper, newsprint and magazine, printing and writing paper, a sanitary wipe, a tissue, paper toweling, a paper bag, a container board, apparel, bleached board, a corrugated medium, unbleached Kraft paper, a decorative laminate, security paper and currency, grand scale graphic paper, Kraft liner, testliner, folding box board, cigarette wrapping paper, an air or liquid filter, a gypsum liner, printable labels, metallized paper, disposable bed sheeting and linens, medical packaging paper, an envelope, blotter paper, a sticky note, medical tape, a tea bag envelope, a sublimation paper for digital transfer printing, sausage wrapping paper, head rest sheets, vacuum cleaner bag, or a geotextile, or a disposable food and drink product comprising a lid, sealing paper, tray, cup, container for consumable liquids, or machine glaze base paper used in lidding or sealing. 
     
     
         4 . The wet laid product of  claim 1 , wherein the wet laid product satisfies the following criteria:
 1) is biodegradable in that at least 90% of its carbon content is converted within 180 days;   2) is disintegratable in that least 90% of the wet laid product, package, or packing article disintegrates within 12 weeks;   
       where each of these conditions are tested, as applicable, under ASTM D6400, or ISO 17088, or EN 13432 test methods. 
     
     
         5 . The wet laid product of  claim 1 , wherein the wet laid product further satisfies the following criteria:
 a. does not contain heavy metals or fluorine beyond the thresholds established under the EN12423 standard; and   b. the disintegrated content supports future plant growth as humus;   
       where each of these conditions are tested, as applicable, under ASTM D6400, or ISO 17088, or EN 13432 test methods. 
     
     
         6 . The wet laid product of  claim 1 , wherein the wet laid product meets the following four criteria under the conditions and methods of ASTM D6400 or EN 13432:
 1) is biodegradable determined by measuring the carbon dioxide produced by the sample under controlled composting conditions following ISO 14855-1:2012, where the sample is mixed with compost and placed in a bioreactor at 58° C. under continuous flow of humidified air; and   2) is disintegratable in a composting environment following ISO 16929:2013, where the samples in their final form are mixed with fresh artificial bioresidue, and after 12 weeks, the resulting composts are sieved and less than 90% of the wet laid product, package, or packing article having a size of greater than 2 mm remains, and   3) the remaining compost is not ecotoxic under OECD 208 (2006), where the wet laid product, package, or packing article in powder form is added to a bioreactor with fresh bioresidue and containing seedlings and following the same procedure as in step (b), and a comparison of seedling emergence and growth in the compost resulting from a bioreactor containing the wet laid product, package, or packing article (sample) and a bioreactor containing the same ingredients without the wet laid product, package, or packing article (blanks) correlates within 90%, and   4) lacks Zn, Cu, Ni, Cd, Pb, Hg, Cr, Mo, Se, As, and Co beyond the thresholds established under the EN12423.   
     
     
         7 . The wet laid product of  claim 1 , wherein the wet laid product contains a CE staple fiber, or is obtained from a composition containing a CE staple fiber, wherein the CE staple fiber has a degree of substitution of not more than 2.5. 
     
     
         8 . The wet laid product of  claim 1 , wherein the wet laid product does not contain an agent to accelerate or promote biodegradation or decomposition of the wet laid product, package, or packing article. 
     
     
         9 . The wet laid product of  claim 1 , wherein the wet laid product is soil biodegradable under ISO 17556:2003. 
     
     
         10 . The wet laid product of  claim 1 , wherein the wet laid product possesses at least one of the following biodegradability characteristics (i) through (iii):
 (i) a biodegradation of at least 90% within not more than 180 days, measured according to ISO 14855-1 (2012) under industrial composting conditions;   (ii) biodegradation of at least 90% within not more than 2 years, measured according to ISO 17556 (2012) at ambient temperature; and   (iii) biodegradation of at least 90% within not more than 1 year measured according to ISO 14855-1 (2012) under industrial composting conditions.   
     
     
         11 . The wet laid product of  claim 1 , wherein the wet laid product does not contain:
 (i) more than 10 weight percent of plasticizers;   (ii) more than 0.05 weight percent of a photodegradation agent; and   (iii) more than 0.005 weight percent of a biodegradation agent or a decomposition accelerating agent, and   (iv) more than 0.50 weight percent of additives selected from the group consisting of polyesters, enzymes, microorganisms, water soluble polymers, modified cellulose acetate, water-dispersible additives, nitrogen-containing compounds, hydroxy-functional compounds, oxygen-containing heterocyclic compounds, sulfur-containing heterocyclic compounds, anhydrides, monoepoxides, and combinations thereof, wherein the weight percent is based on the total weight of the fiber.   
     
     
         12 . The wet laid product of  claim 1 , wherein the wet laid product is biodegradable in an amount of at least 90% within a period of not more than 100 days under home composting conditions satisfying French norm NF T 51-800 or the Australian standard AS 5810 standards. 
     
     
         13 . The wet laid product of  claim 1 , wherein the wet laid product is biodegradable in an amount of at least 75% in a period of not more than 45 days, when tested under aerobic industrial composting conditions at ambient temperature (28° C.±2° C.) according to ISO 14855-1 (2012). 
     
     
         14 . A process for obtaining biodegradability certification, comprising:
 a. an entity or person making or having made a composition containing cellulose ester (CE) staple fibers or an article containing or obtained from a composition containing CE staple fibers,   b. the entity or person furnishing the article or composition directly or indirectly to a laboratory that is not directly or indirectly owned by or controlled by the entity or person to have the laboratory perform biodegradation tests on the article or composition in accordance with a methodology acceptable to a certification agency.   
     
     
         15 . The process of  claim 14 , wherein the CE staple fiber is made from or obtained with a cellulose ester polymer having a degree of substitution of not more than 2.5. 
     
     
         16 . The process of  claim 14 , further comprising:
 c. the entity or person submit the results of the laboratory tests to a certification agency or has the laboratory submit the results to the certification agency or has the laboratory grant the certification agency access to the results.   
     
     
         17 . The process of  claim 14 , wherein the first entity or person selects a laboratory that is approved by the certification agency as compliant with test methods specified by the certification agency to issue a biodegradation certification. 
     
     
         18 . The process of  claim 14 , wherein the first entity or person receives a certification from the certification agency that the article or composition is biodegradable. 
     
     
         19 . A packaging article comprising cellulose ester (CE) staple fibers or obtained by a composition comprising cellulose fibers and CE staple fibers, said article bearing an indicia of biodegradation certification. 
     
     
         20 . The packaging article of  claim 19 , wherein the article is a container containing content(s), and the contents comprise wet laid products or one or more articles containing or obtained from a composition containing cellulose fibers and CE staple fibers, and said contents bear an indicia of biodegradation certification. 
     
     
         21 . Use of a cellulose ester (CE) staple fiber to modify one or more properties of a wet laid product containing cellulose fibers:
 a. water drainage rate,   b. water absorbency,   c. air permeability,   d. density at an equivalent basis weight,   e. bulk,   f. softness,   g. stiffness,   h. embossing performance,   i. caliper rebound,   j. brightness,   k. tensile strength   l. removal of ink particles;   wherein said CE staple fibers have:
 i. a denier per filament (DPF) of less than 3, 
 ii. a cut length of less than 6 mm, 
 iii. crimping, 
 iv. or a combination of any two or more of (i)-(iii); and 
   said wet laid product is biodegradable.   
     
     
         22 . The use of the CE staple fiber of  claim 21 , wherein the wet laid product is compostable and has a degree of substitution of not more than or less than 2.5.