Methods for making lignocellulose containing composite products

Patent metadata

Field	Value
Publication number	US-9458298-B2
Application number	US-201314040791-A
Country	US
Kind code	B2
Filing date	Sep 30, 2013
Priority date	Oct 1, 2012
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Methods for making composite products are provided. In at least one specific embodiment, the method can include combining a plurality of lignocellulose substrates and one or more free radical precursors to produce a mixture of the lignocellulose substrates and the one or more free radical precursors. The method can also include maintaining the mixture at a temperature less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the one or more free radical precursors charged to the mixture. The method can then include heating the mixture comprising at least 11 wt % of the one or more free radical precursors charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product. The composite product can have a density less than 1 g/cm 3 and an internal bond strength of at least 0.35 MPa.

First claim

What is claimed is:

1. A method for making a composite product, comprising:
combining a plurality of lignocellulose substrates and one or more free radical precursors comprising a catalyst and an oxidant to produce a mixture of the lignocellulose substrates and the one or more free radical precursors;
maintaining the mixture at a temperature less than 60° C. for at least 10 minutes while retaining at least 11 wt % of the oxidant charged to the mixture; and then
heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product having a density less than 1 g/cm 3 and an internal bond strength of at least 0.35 MPa.

2. The method of claim 1 , wherein the mixture is maintained at the temperature less than 60° C. for at least 20 minutes while retaining at least 25 wt % of the oxidant charged to the mixture, and wherein the mixture comprising at least 25 wt % of the oxidant charged to the mixture is heated to the temperature of at least 60° C. to about 300° C. to produce the composite product.

3. The method of claim 1 , wherein the mixture is maintained at the temperature less than 60° C. for at least 30 minutes while retaining at least 11 wt % of the oxidant charged to the mixture.

4. The method of claim 1 , wherein the composite product is in the form of a panel having an average thickness, and wherein the mixture is heated to the temperature of at least 60° C. to about 300° C. for about 3 seconds to about 20 seconds per millimeter of the average thickness.

5. The method of claim 1 , wherein, prior to heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to the temperature of at least 60° C. to about 300° C. to produce the composite product, an amount of energy generated from the mixture due to any exothermic reaction is less than 20 cal/g.

6. The method of claim 1 , wherein the composite product has an internal bond strength of at least 0.5 MPa and a density of less than 0.9 g/cm 3 .

7. The method of claim 1 , wherein the oxidant comprises hydrogen peroxide.

8. The method of claim 1 , wherein the oxidant comprises hydrogen peroxide and the catalyst comprises one or more iron containing catalysts.

9. The method of claim 8 , wherein an amount of the one or more iron containing catalysts present in the mixture is from about 0.05 wt % to about 5 wt %, based on a dry weight of the plurality of lignocellulose substrates.

10. The method of claim 1 , wherein the catalyst comprises one or more metals in the form of a complex bound to one or more complexing agents.

11. The method of claim 10 , wherein the one or more complexing agents comprise cyanide, sulfate, ethylenediaminetetraacetic acid (EDTA), ethylenediamine-N,N′-disuccinic acid (EDDS), ethyleneglycol-bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid (EGTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-diaminocyclohexane tetraacetic acid (CDTA), iminodisuccinate (IDS), nitrilotriacetic acid (NTA), or any mixture thereof.

12. The method of claim 1 , wherein the catalyst comprises potassium ferricyanide, an iron complex of ethylenediaminetetraacetic acid, an iron complex of (S,S′)-ethylenediamine-N,N′-disuccinic acid, an iron complex of diethylenetriamine pentaacetic acid, an iron complex of ethyleneglycol-bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, an iron complex of trans-1,2-diaminocyclohexanetetraacetic acid, or any mixture thereof.

13. The method of claim 1 , wherein the mixture is maintained at the temperature less than 60° C. for at least 20 minutes while retaining at least 35 wt % of the oxidant charged to the mixture, and wherein the mixture comprising at least 35 wt % of the oxidant charged to the mixture is heated to the temperature of at least 60° C. to about 300° C. to produce the composite product.

14. The method of claim 1 , further comprising combining one or more polyphenolic compounds with the plurality of lignocellulose substrates and the one or more free radical precursors to produce the mixture, wherein the one or more polyphenolic compounds comprise lignin, tannins, a novolac resin, modified phenol formaldehyde resin, bis-phenol A, humic acids, or any mixture thereof.

15. A method for making a composite product, comprising:
combining a plurality of lignocellulose substrates, one or more free radical precursors comprising a catalyst and an oxidant, and one or more compounds comprising at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals to produce a mixture; and
heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product.

16. The method of claim 15 , wherein the mixture is maintained at a temperature less than 60° C. for at least 10 minutes prior to heating the mixture comprising at least 11 wt % of the oxidant charged to the mixture to the temperature of at least 60° C. to about 300° C., and wherein the composite product has a density less than 1 g/cm 3 and an internal bond strength of at least 0.35 MPa.

17. The method of claim 15 , wherein the one or more compounds comprising at least two hydrogen atoms that are abstractable in the presence of hydroxyl radicals comprise lignin, tannins, a novolac resin, bis-phenol A, modified phenol formaldehyde resin, humic acid, or any mixture thereof.

18. The method of claim 15 , wherein the mixture comprises at least 20 wt % of the oxidant charged to the mixture when heated to the temperature of at least 60° C. to about 300° C. to produce the composite product.

19. The method of claim 15 , wherein the catalyst comprises potassium ferricyanide, an iron complex of ethylenediaminetetraacetic acid, an iron complex of (S,S′)-ethylenediamine-N,N′-disuccinic acid, an iron complex of diethylenetriamine pentaacetic acid, an iron complex of ethyleneglycol-bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, an iron complex of trans-1,2-diaminocyclohexanetetraacetic acid, or any mixture thereof.

20. A method for making a composite product, comprising:
combining a plurality of lignocellulose substrates and one or more free radical precursors comprising one or more iron containing catalysts and hydrogen peroxide to produce a mixture; and
heating the mixture comprising at least 11 wt % of the hydrogen peroxide charged to the mixture to a temperature of at least 60° C. to about 300° C. to produce a composite product, wherein:
the one or more iron containing catalysts are present in the mixture in an amount of about 0.05 wt % to about 5 wt %, based on a dry weight of the plurality of lignocellulose substrates, and
the one or more iron containing catalysts comprise potassium ferricyanide, an iron complex of ethylenediaminetetraacetic acid, an iron complex of (S,S′)-ethylenediamine-N,N′-disuccinic acid, an iron complex of diethylenetriamine pentaacetic acid, an iron complex of ethyleneglycol-bis(2-aminoethyl)-N,N,N′,N′-tetraacetic acid, an iron complex of trans-1,2-diaminocyclohexanetetraacetic acid, or any mixture thereof.

Assignees

• Georgia Pacific Chemicals Llc

Inventors

• Sniady Adam K
• Hagiopol Cornel
• Atkinson Derek L
• Williamson Bobby L
• Hines John B

Classifications

• C08L97/02

  Lignocellulosic material, e.g. wood, straw or bagasse {(manufacture of articles made from lignocellulosic material by dry processes B27N)} · CPC title

• B27N3/02

  from particles · CPC title

• C08H6/00

  Macromolecular compounds derived from lignin, e.g. tannins, humic acids · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• B27N3/002 Primary

  characterised by the type of binder (compositions of macromolecular compounds C08L) · CPC title