# US 8,785,526 B2 · Polyoxymethylene fibers in concrete > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,526 B2 - Document ID: US8785526B2 - Status: Granted - Kind: B2 - Application number: 13/325,171 - Filed: 2011-12-14 - Published: 2012-06-21 - Granted: 2014-07-22 - Earliest claimed: 2010-12-16 - Assignees: Ticona LLC - Applicants: Steven Bassetti; Robert M. Gronner; Thomas Heyer; Hanno Hueckstaedt; Arvind Karandikar - Inventors: Steven Bassetti; Robert M. Gronner; Thomas Heyer; Hanno Hueckstaedt; Arvind Karandikar - Web page: https://patentgrep.com/patent/US8785526B2 ## CPC - D01F 6/70: from polyurethanes - C04B 16/0675: {from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds} - C04B 28/02: containing hydraulic cements other than calcium sulfates - D01F 6/66: from polyethers - D01F 6/78: from copolycondensation products - C04B 2103/0051: {Water-absorbing polymers, hydrophilic polymers} - Y10T 428/298: Physical dimension - D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Disclosed are polymeric additives for concrete formed of a polyoxymethylene (POM) copolymer. POM copolymers can be utilized to form fibrous additives for concrete, i.e., microfibers and/or macrofibers. The POM copolymers can include one or more chemical groups, e.g., end groups and/or pendant groups that can increase the polarity of the POM and increase the hydrophilicity of the formed fibers, which can improve miscibility of the fibers in wet concrete. Chemical groups of the POM copolymers can bond with components of the concrete or can hydrolyze to form groups that can bond with components of the concrete, e.g., form covalent or noncovalent (e.g., electrostatic or ionic) bonds with one or more components of the concrete binder. ## Claims ### Claim 1 A concrete comprising: an aggregate; a cementitious binder; and a plurality of discrete fibers randomly distributed throughout the concrete, the fibers comprising a polyoxymethylene copolymer in an amount of at least about 50% by weight of the fibers, at least about 50% of the terminal groups of the polyoxymethylene copolymer being hydroxyl groups, the fibers exhibiting a water contact angle of less than about 30°, the fibers comprising microfibers and/or macrofibers. ### Claim 2 (depends on 1) The concrete of claim 1, wherein the fibers exhibit a water contact angle of less than about 20°. ### Claim 3 (depends on 1) The concrete of claim 1, wherein the polyoxymethylene copolymer is the product of a copolymerization reaction of trioxane with a cyclic acetal containing at least one O(CH2)n group where n is greater than 1. ### Claim 4 (depends on 1) The concrete of claim 1, wherein the polyoxymethylene copolymer is the product of a copolymerization reaction of trioxane with a cyclic formal having pendant acrylate or substituted acrylate ester groups. ### Claim 5 (depends on 1) The concrete of claim 1, wherein the polyoxymethylene copolymer is the product of a copolymerization reaction of trioxane with a cyclic ester. ### Claim 6 (depends on 1) The concrete of claim 1, wherein the polyoxymethylene copolymer is the product of a copolymerization reaction of trioxane with glycerol formal acetate. ### Claim 7 (depends on 1) The concrete of claim 1, wherein the polyoxymethylene copolymer is the product of a copolymerization reaction of trioxane with glycerol formal formate. ### Claim 8 (depends on 1) The concrete of claim 1, wherein the polyoxymethylene copolymer comprises three or more different monomer units. ### Claim 9 (depends on 1) The concrete of claim 1, wherein the melt index of the polyoxymethylene copolymer is between about 2 dg/min and about 30 dg/min. ### Claim 10 (depends on 1) The concrete of claim 1, the fibers further comprising an impact modifier. ### Claim 11 (depends on 1) The concrete of claim 1, the composite comprising the microfibers in an amount of from about 1 pound per cubic yard up to about 3 pounds per cubic yard. ### Claim 12 (depends on 1) The concrete of claim 1, the composite comprising the macrofibers in an amount of from about 2 pounds per cubic yard up to about 8 pounds per cubic yard. ### Claim 13 (depends on 1) The concrete of claim 1, wherein the fibers are deformed fibers. ### Claim 14 (depends on 1) The concrete of claim 1, the composite comprising a mixture of different fibers. ### Claim 15 (depends on 1) The concrete of claim 1, wherein the fibers are less than about 5 inches in length. ### Claim 16 (depends on 1) The concrete of claim 1, wherein the fibers are drawn fibers. ### Claim 17 A method of forming concrete comprising randomly dispersing a plurality of discrete fibers throughout the concrete, the fibers comprising a polyoxymethylene copolymer in an amount of at least about 50% by weight of the fibers, at least about 50% of the terminal groups of the polyoxymethylene copolymer being hydroxyl groups, the fibers exhibiting a water contact angle of less than about 30°, the fibers comprising microfibers and/or macrofibers. ### Claim 18 (depends on 17) The method according to claim 17, further comprising forming the fibers from a composition including the polyoxymethylene copolymer. ### Claim 19 (depends on 18) The method according to claim 18, wherein the fibers are extruded or spun from a melt of the composition. ### Claim 20 (depends on 18) The method according to claim 18, further comprising drawing the fibers. ### Claim 21 (depends on 17) The method according to claim 17, further comprising mixing the fibers with dry cement. ### Claim 22 (depends on 17) The method according to claim 17, further comprising mixing the fibers with wet cement. ### Claim 23 (depends on 10) The concrete of claim 10, wherein the impact modifier comprises a thermoplastic elastomer. ### Claim 24 (depends on 10) The concrete of claim 10, the fibers further comprising a coupling agent capable of coupling the impact modifier to the polyoxymethylene copolymer. ### Claim 25 (depends on 1) The concrete of claim 1, wherein the macrofibers have a denier of between about 500 denier and about 4000 denier. ### Claim 26 (depends on 1) The concrete of claim 1, wherein the microfibers have a denier of between about 1 denier and about 10 denier. ### Claim 27 (depends on 17) The method according to claim 17, wherein the macrofibers have a denier of between about 500 denier and about 4000 denier. ### Claim 28 (depends on 21) The method according to claim 21, wherein the microfibers have a denier of between about 1 denier and about 10 denier.