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US-12617874-B2 - Cyclodextrin-polyoxometalate ionic liquid inclusion complex flame retardant additive for making a low smoke zero halogen compound

US12617874B2US 12617874 B2US12617874 B2US 12617874B2US-12617874-B2

Abstract

Embodiments of a flame retardant compound are provided. The flame retardant compound includes a polymer base resin and a flame retardant additive distributed within the polymer base resin. The flame retardant additive includes inclusion complexes that are made of at least one guest molecule and at least one carbonific host molecule. The at least one guest molecules is a polyoxometalate ionic liquid. The flame retardant compound achieves a limiting oxygen index of at least 25% according to ISO 4589. Additionally, embodiments of a flame retardant cable are provided that utilize the flame retardant compound as a jacketing material.

Inventors

  • Dayue Jiang
  • Kevin Andrew Vasilakos

Assignees

  • CORNING INCORPORATED

Dates

Publication Date
20260505
Application Date
20230519

Claims (15)

  1. 1 . A flame retardant compound comprising: a polymer base resin; a synergist; and a flame retardant additive distributed within the polymer base resin, the flame retardant additive including inclusion complexes, wherein each inclusion complex comprises: at least one guest molecule, wherein each of the at least one guest molecules is a polyoxometalate ionic liquid; and at least one carbonific host molecule; and wherein the flame retardant compound achieves a limiting oxygen index of at least 25% according to ISO 4589; wherein the flame retardant compound is comprised of from 0.1 to 15 wt % of the inclusion complexes; and wherein the synergist comprises at least one of zeolite or zinc borate.
  2. 2 . The flame retardant compound of claim 1 , wherein the polyoxometalate ionic liquid includes polyoxometalate anions containing molybdenum.
  3. 3 . The flame retardant compound of claim 2 , wherein the polyoxometalate anion is derived from at least one of molybdenum trioxide, ammonium octamolybdate, ammonium phosphomolybdate, molybdenum acetate, calcium molybdate, zinc molybdate, or molybdenum dialkyldithiocarbamate.
  4. 4 . The flame retardant compound of claim 1 , wherein the polyoxometalate ionic liquid is formed from an ionic liquid including at least one based on an ammonium, an imidazolium, a guanidinium, a pyridium, a morpholinium, a pyridazinium, a 1,2,4-triazolium, a triazine, a sulfonium, a phosphazenium, or a phosphonium and an anion based on a sulfate, a sulfonate, a phosphate, or a borate.
  5. 5 . The flame retardant compound of claim 1 , wherein the at least one carbonific host molecule is a cyclodextrin.
  6. 6 . The flame retardant compound of claim 5 , wherein the cyclodextrin is at least one of alpha, beta, gamma, or larger cyclodextrins.
  7. 7 . The flame retardant compound of claim 5 , wherein the cyclodextrin is a chemically modified derivative of cyclodextrin.
  8. 8 . The flame retardant compound of claim 1 , wherein the at least one carbonific host molecule is at least one of calixarene or chemically modified derivatives of calixarene, zeolites, chibaite, urea, thiourea, hydroquinone, or 4-p-hydroxyphenyl-2,2,4-trimethylchroman.
  9. 9 . The flame retardant compound of claim 1 , wherein the base resin includes at least one of ethylene-vinyl acetate copolymers; ethylene-acrylate copolymers; low, medium, and high density polyethylene homopolymers; linear low density polyethylene; very low density polyethylene; polyolefin elastomer copolymer; polypropylene homopolymer; polyethylene-polypropylene copolymer; butene- and octene branched copolymers; maleic anhydride-grafted versions of the previously listed polyolefins; polyvinyl chloride; polyamide 6; polyamide 6/6; polyamide 11; polyamide 12; thermoplastic polyurethane; or crosslinked polyethylene.
  10. 10 . The flame retardant compound of claim 1 , wherein the flame retardant additive further includes at least one of a metal hydrate, a char strength booster, a synergist, or a gas-forming compound.
  11. 11 . The flame retardant compound of claim 1 , wherein the flame retardant additive further includes a carbonific source in addition to the at least one carbonific host molecule, an acid donor, and a spumific agent.
  12. 12 . The flame retardant compound of claim 11 , wherein the carbonific source is at least one of a polyol, a starch, or polyamide-6.
  13. 13 . The flame retardant compound of claim 11 , wherein the acid donor is at least one of ammonium polyphosphate, diammonium diphosphate, or diammonium pentaborate.
  14. 14 . The flame retardant compound of claim 11 , wherein a single compound is both the acid donor and the spumific agent.
  15. 15 . The flame retardant compound of claim 1 , wherein the ratio of carbonific host molecule to polyoxometalate anion of the polyoxometalate ionic liquid is more than 0 and less than or equal to 3.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional of U.S. patent application Ser. No. 16/776,555 filed Jan. 30, 2020, now U.S. Pat. No. 11,667,846, which is continuation of International Application No. PCT/US2018/044339 filed Jul. 30, 2018, which claims the benefit of priority of U.S. Provisional Application Ser. No. 62/539,765, filed Aug. 1, 2017, the content of which is relied upon and incorporated herein by reference in its entirety. BACKGROUND The disclosure relates generally to flame retardant compounds and more particularly to a thermoplastic flame retardant compound. Flame retardant materials are used to protect combustible materials, such as plastics or wood, from fire damage and heat. Additionally, flame retardant materials have been used to protect materials that lose their strength when exposed to high temperatures, such as steel. SUMMARY In one aspect, embodiments of a flame retardant compound are provided. The flame retardant compound includes a polymer base resin and a flame retardant additive distributed within the polymer base resin. The flame retardant additive includes inclusion complexes that are made of at least one guest molecule and at least one carbonific host molecule. The at least one guest molecules is a polyoxometalate ionic liquid. The flame retardant compound achieves a limiting oxygen index of at least 25% according to ISO 4589. In another aspect, embodiments of a flame retardant cable are provided. The flame retardant cable includes at least one communication element and a polymeric jacket that surrounds the at least one communication element. The polymeric jacket is formed from a flame retardant compound that includes a polymer base resin and a flame retardant additive distributed within the polymer base resin. The flame retardant additive includes inclusion complexes that are formed of at least one guest molecule and at least one carbonific host molecule. Each of the at least one guest molecules is a polyoxometalate ionic liquid. Additional features and advantages will be set forth in the detailed description that follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings. It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understand the nature and character of the claims. The accompanying drawings are included to provide a further understanding and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and the operation of the various embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a schematic representation of a flame retardant inclusion complex according to an exemplary embodiment; FIGS. 2A-2B depict an α-cyclodextrin host molecule according to an exemplary embodiment; FIGS. 3A-3B depict a β-cyclodextrin host molecule according to an exemplary embodiment; FIGS. 4A-4B depict a γ-cyclodextrin host molecule according to an exemplary embodiment; FIGS. 5A-5C depict a β-cyclodextrin and ionic liquid modified octamolybdate partial and full inclusion complexes, according to an exemplary embodiment; FIG. 6 depicts a graphical representation of the limiting oxygen index of three samples, including a sample containing an inclusion complex, according to an exemplary embodiment; and FIG. 7 depicts a cable including a flame retardant material according to an exemplary embodiment. DETAILED DESCRIPTION Referring generally to the figures, various embodiments of a low-smoke, zero halogen (LSZH) flame retardant compound and its applications are shown. In general, the embodiments discussed herein relate to a thermoplastic compound comprised of a polymer, such as a polyolefin homopolymer or copolymer base resin, and an LSZH flame retardant additive. The LSZH flame retardant additive includes a carbon source. More specifically, the carbon source is, at least in part, in the form of inclusion complexes in which each inclusion complex has one or more host molecules and a guest molecule. The host molecule is a carbonific molecule, and the guest molecule is an ionic liquid (IL) modified polyoxometalate (POM), or as used herein, a polyoxometalate ionic liquid (PIL). The inclusion complex is part of an LSZH flame retardant additive that can be added to various thermoplastic resins to provide a thermoplastic LSZH flame retardant compound. The host and guest molecules interact physically at the molecular level, such that each host molecule is part of a complex with a guest molecule. Thus, during the compounding process of a thermoplastic LSZH fire retardant compound, the host molecules are advantageously able to resist aggregating with the othe