U.S. patent application number 13/322907 was filed with the patent office on 2012-10-04 for derivatives of native lignin, lignin-wax compositions, their preparation and uses thereof.
Invention is credited to Alex Berlin, Paul Mulyk.
Application Number | 20120247617 13/322907 |
Document ID | / |
Family ID | 43220959 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120247617 |
Kind Code |
A1 |
Berlin; Alex ; et
al. |
October 4, 2012 |
DERIVATIVES OF NATIVE LIGNIN, LIGNIN-WAX COMPOSITIONS, THEIR
PREPARATION AND USES THEREOF
Abstract
A wax composition comprising a lignin derivative wherein the
derivative has a total hydroxyl content of from about 0.1 mmol/g to
about 7 mmol/g.
Inventors: |
Berlin; Alex; (Davis,
CA) ; Mulyk; Paul; (Vancouver, CA) |
Family ID: |
43220959 |
Appl. No.: |
13/322907 |
Filed: |
May 27, 2010 |
PCT Filed: |
May 27, 2010 |
PCT NO: |
PCT/CA10/00801 |
371 Date: |
February 27, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61182044 |
May 28, 2009 |
|
|
|
61233345 |
Aug 12, 2009 |
|
|
|
Current U.S.
Class: |
144/344 ;
106/164.01; 106/270; 530/500 |
Current CPC
Class: |
C08J 3/00 20130101; Y02P
60/877 20151101; C08H 6/00 20130101; A23K 10/32 20160501; D21C
11/0007 20130101; C08L 97/005 20130101; B27N 3/002 20130101; D21H
11/00 20130101; C08L 57/00 20130101; C08J 2397/00 20130101; A61K
36/15 20130101; C08K 5/13 20130101; C08L 23/02 20130101; C08L
2207/04 20130101; C09K 15/06 20130101; A23L 33/105 20160801; C08L
97/02 20130101; C08L 91/06 20130101; Y02P 60/87 20151101; A61K
36/48 20130101; Y02P 20/582 20151101; A61K 36/54 20130101; C07G
1/00 20130101; C08L 2201/52 20130101; A61K 36/76 20130101 |
Class at
Publication: |
144/344 ;
530/500; 106/270; 106/164.01 |
International
Class: |
C08L 97/02 20060101
C08L097/02; C09D 197/00 20060101 C09D197/00; B27D 5/00 20060101
B27D005/00; C07G 1/00 20110101 C07G001/00 |
Claims
1. A derivative of native lignin wherein said lignin derivative has
a total hydroxyl content of from about 0.1 mmol/g to about 7
mmol/g.
2. A lignin derivative according to claim 1 wherein the derivative
has a total hydroxyl content of from about 3.5 mmol/g to about 6.8
mmol/g.
3. A lignin derivative according to claim 1 wherein the derivative
has a total hydroxyl content of from about 4.5 mmol/g to about 6.5
mmol/g
4. A lignin derivative according to claim 1 wherein the derivative
comprises alkoxy groups.
5. A lignin derivative according to claim 1 wherein the biomass
from which the lignin is derived comprises hardwood biomass.
6. A lignin derivative according to claim 1 wherein the biomass
from which the lignin is derived comprises softwood biomass.
7. A lignin derivative according to claim 1 wherein the biomass
from which the lignin is derived comprises annual fibre
biomass.
8. A lignin derivative according to claim 1 wherein the biomass
from which the lignin is derived comprises Populus spp, Eucalyptus
spp., Acacia spp., or combinations/hybrids thereof.
9. A lignin derivative according to claim 1 wherein the biomass
from which the lignin is derived comprises pine; spruce; or
combinations/hybrids thereof
10. A lignin derivative according to claim 1 wherein the biomass
from which the lignin is derived comprises wheat straw, bagasse,
corn cobs, or combinations/hybrids thereof.
11. A wax composition comprising a lignin derivative according to
claim 1.
12. A composition according to claim 11 wherein the composition is
an emulsion.
13. A composition according to claim 11 comprising, on the basis of
the solid content, from about 1% to about 50%, by weight, of lignin
derivative.
14. A slack wax composition comprising a lignin derivative
according to claim 1.
15. A method for preparing a lignin-modified wax emulsion, the
method comprising: a. preparing an aqueous solution comprising one
of a surface tension reducing agent and an interfacial tension
reducing agent; b. commingling with the aqueous solution a selected
amount of a base; c. commingling with the aqueous solution
containing therein said base, a selected amount of a lignin
derivative according to claim 1; d. separating the aqueous solution
into a filtrate and a retentate wherein the mixture of lignin
derivatives is commingled with said filtrate; and e. commingling a
selected volume of the filtrate with a selected volume of a wax
emulsion.
16. A method according to claim 15, where the one of a surface
tension reducing agent and an interfacial tension reducing agent is
selected from a group consisting of lignosulphonates, isogenic
lignin derivatives, ionogenic detergents exemplified by sodium
dodecyl sulfate and the like, and combinations thereof.
17. A lignin-modified wax emulsion produced according to the method
of claim 15
18. A wax emulsion comprising water, an emulsified wax, one of a
surface tension reducing agent and an interfacial tension reducing
agent, a base, and a lignin derivative according to claim 1.
19. A composite wood product comprising a lignin-modified wax
composition according to claim 11.
20. A method of producing a composite wood product, said method
comprising: a. Obtaining a cellulosic fibre material; b. Obtaining
an adhesive suitable for adhering the fibres of said material; c.
Mixing said cellulosic material with said adhesive, forming the
mixture into a suitable shape and curing; and d. Applying a wax
composition according to claim 11 to the cured article.
Description
FIELD
[0001] This disclosure relates to derivatives of native lignin.
This disclosure further relates to wax emulsions comprising
derivatives of native lignin such as, for example, those suitable
for production of wood composite materials. This disclosure further
relates to waxy compositions, processes for their preparation, and
methods for their use.
BACKGROUND
[0002] Wood composites are among the world's most significant
renewable materials. The most common wood composites produced today
are oriented strandboard (OSB), plywood, and particle board. Waxes
are commonly used in the production of wood composites. The
production of wood composites generally includes the blending of
dried wood strands and/or particles with a suitable oil-derived
liquid wax formulation and an adhesive (resin). These materials are
generally derived from non-renewable sources. The wax component may
provide water repellant properties that reduce swelling of
composites during periods of elevated environmental humidity. The
resin components bind wood strands and/or particles to form the
composite structures. The addition of wax components to the wood
composites is thought to improve the mechanical and physical
properties of the panels.
[0003] Generally, after blending the wood feedstock with a wax
emulsion and a resin, the wood composite is formed by applying
suitable pressure at elevated temperatures. Optimal application of
pressure and temperature levels are determined from the
specifications of the wax and resin components used, the type of
composite being produced, and the tree species from which the wood
fibers and/or strands and/or particles are produced. Once the wood
composites are produced, a number of quality/performance
characteristics are determined including, thickness swell, water
adsorption, modulus of rupture, modulus of elasticity, internal
bond, among others. The testing protocols for each type of wood
composite have been well-defined by the respective regulatory
bodies. Examples of these standards include: the Canadian Standards
Association (CSA) O112.6-M1977 Phenol and Phenol-Resorcinol Resin
Adhesives for Wood (High-Temperature Curing), the CSA O437.1-93
Test Methods for OSB and Waferboard, or the CSA Standard O151-04
Canadian softwood plywood. Before the commercialization of new
resin (adhesive) it is usually necessary for them to meet the
established standards such as the ones listed above.
[0004] Native lignin is a naturally occurring amorphous complex
cross-linked organic macro-molecule that comprises an integral
component of all plant biomass. Extracting native lignin from
lignocellulosic biomass during pulping generally results in lignin
fragmentation into numerous mixtures of irregular components.
Furthermore, the lignin fragments may react with any chemicals
employed in the pulping process. Consequently, the generated lignin
fractions can be referred to as lignin derivatives and/or technical
lignins. As it is difficult to elucidate and characterize such
complex mixture of molecules, lignin derivatives are usually
described in terms of the lignocellulosic plant material used, and
the methods by which they are generated and recovered from
lignocellulosic plant material, i.e. hardwood lignins, softwood
lignins, and annual fibre lignins.
[0005] Given that lignin derivatives are available from renewable
biomass sources there is an interest in using these derivatives in
certain industrial applications. For example, lignin derivatives
obtained via organosolv extraction, such as the Alcell.RTM. process
(Alcell is a registered trademark of Lignol Innovations Ltd.,
Burnaby, BC, CA), have been used in rubber products, adhesives,
resins, plastics, asphalt, cement, casting resins, agricultural
products, oil-field products and as feedstocks for the production
of fine chemicals. It has been suggested to use lignin-modified
phenol-formaldehyde resin as an adhesive for wood composites (see,
for example, U.S. Pat. No. 5,010,156; WO93/21260; WO94/24192).
[0006] However, large-scale commercial application of the extracted
lignin derivatives, has been limited due to, for example, the
inconsistency of their chemical and functional properties. This
inconsistency may, for example, be due to changes in feedstock
supplies and the particular extraction/generation/recovery
conditions. These issues are further complicated by the complexity
of the molecular structures of lignin derivatives produced by the
various extraction methods and the difficulty in performing
reliable routine analyses of the structural conformity and
integrity of recovered lignin derivatives.
[0007] Despite the advantages of lignin, for a variety of reasons,
it has not been adopted for widespread use in wood composites. For
instance, it is often problematic to provide lignins that have
acceptable and consistent performance characteristics.
Additionally, the cost of producing and/or purifying the lignin may
make it uneconomic for certain uses. Furthermore, incorporation of
high levels of lignin in phenol-formaldehyde resin can lead to
undesirably high end-point viscosities.
SUMMARY
[0008] The present disclosure provides derivatives of native lignin
having a certain hydroxyl content. Surprisingly, it has been found
that consistent and predictable properties may be provided by
selecting for derivatives of native lignin having certain hydroxyl
contents.
[0009] The present disclosure provides derivatives of native lignin
having a total hydroxyl content of from about 0.1 mmol/g to about 7
mmol/g. Such lignins have surprisingly been found to have an
appropriate hydrophobicity for use in the wax component in the
production of wood composites.
[0010] As used herein, the term "native lignin" refers to lignin in
its natural state, in plant material.
[0011] As used herein, the terms "lignin derivatives" and
"derivatives of native lignin" refer to lignin material extracted
from lignocellulosic biomass. Usually, such material will be a
mixture of chemical compounds that are generated during the
extraction process.
[0012] Some exemplary embodiments of the present disclosure relate
to lignin-modified wax composition, such as an emulsion or a
suspension, suitable for production of composite materials
exemplified by composite wood products and the like.
[0013] Some exemplary embodiments of the present disclosure relate
to lignin derivatives suitable for production of lignin-modified
wax compositions. Suitable lignin derivatives generally comprise
lignin derivatives that are solubilized from lignocellulosic
biomass by an organosolv process.
[0014] This summary does not necessarily describe all features of
the invention. Other aspects, features and advantages of the
invention will be apparent to those of ordinary skill in the art
upon review of the following description of specific embodiments of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present disclosure will be described in conjunction with
reference to the following drawings, in which:
[0016] FIG. 1 is a schematic flowchart showing various exemplary
embodiments of a modular biorefinery processing system for recovery
of four distinct structural classes of lignin derivatives from
lignocellulosic feedstocks with organic solvents;
[0017] FIG. 2 is a schematic flowchart of an exemplary modular
continuous counter-flow biorefinery system configured for
separation and recovery of three lignin solids fractions from a
lignocellulosic feedstock.
DETAILED DESCRIPTION
[0018] The present disclosure provides derivatives of native lignin
having a total hydroxyl content of from about 0.1 mmol/g to about 7
mmol/g. The present lignin derivatives may have a total hydroxyl
content of from about 1 mmol/g, about 2 mmol/g, 3.5 mmol/g, 4
mmol/g, 4.5 mmol/g, or greater. The present lignin derivatives may
have a total hydroxyl content of from about 6.8 mmol/g, about 6.7
mmol/g, about 6.6 mmol/g, about 6.5 mmol/g, or less.
[0019] The present lignin derivatives may be used in the production
of wood composite materials. Examples of wood composites include
low density fibreboard (LDF), medium density fibreboard (MDF), high
density fibreboard (HDF), strawboard & other agricultural
fibre/particle boards, oriented strand board (OSB), particle board,
plywood, and the like. The present lignin derivatives may be used
in the production of wood-plastic composites.
[0020] The present lignin derivatives may be incorporated into the
wax compositions useful in the manufacture of wood composites. The
present wax composition may be an emulsion, suspension, or the
like.
[0021] The present wax compositions preferably comprise, on the
basis of the solid contents, about 50% or less, about 45% or less,
about 40% or less, about 35% or less, about 30% or less, of lignin
derivative. The present wax compositions preferably comprise, on
the basis of the solid contents, about 0.1 or greater, about 1% or
greater, about 5% or greater, about 10% or greater, about 15% or
greater, about 20% or greater, of lignin derivative.
[0022] Presently, it is common to use "slack waxes" in the
manufacture of wood composites. Slack was is a by-product of the
oil refining process and, as such, is a non-renewable resource
whose cost is subject to the vagaries of crude oil prices.
Furthermore, changes in oil-refinery practices, such as catalytic
dewaxing, are eliminating slack-wax as a by-product.
[0023] The present wax compositions may comprises a variety of
waxes including, but not limited to, fossil waxes (e.g. montan,
ozocerite, pyropissite, and the like); non-fossil waxes such as
animal or vegetable waxes (e.g. bees wax, plant waxes such as
carnauba or candelilla, and the like); partially synthetic waxes
(e.g. alcohol waxes, wool wax, and the like); synthetic waxes (e.g.
amide waxes, polyethylene waxes, Fischer-Tropsch, polyolefins,
Ziegler process wax, and the like); petroleum waxes such as
macro-crystalline waxes or microcrystalline waxes (e.g. paraffins,
slack wax, slack wax raffmates, decoiled slack wax, soft wax,
semi-refined wax, filtered wax, fully refined wax, bright stock
wax, plastic microwaxes, hard microwaxes, and the like); and
combinations thereof. Preferred waxes for use herein include,
petroleum waxes, synthetic waxes, and combinations thereof. For
example, the present wax may be a slack wax.
[0024] The present compositions preferably comprise, on the basis
of the solid contents, about 90% or less, about 80% or less, about
70% or less, of wax. The present compositions preferably comprise,
on the basis of the solid contents, about 20% or greater, about 30%
or greater, about 40% or greater, about 50% or greater, of wax.
[0025] The present compositions may comprise a variety of optional
components such as, for example, water, stabilizer, emulsifier, and
combinations thereof.
[0026] Exemplary embodiments of the present disclosure relate to
lignin-modified wax emulsions suitable for production of wood
composite materials such as, but not limited to, oriented
strandboard (OSB), plywood, and laminated veneerlumber (LVL). For
example, the present lignin derivatives may be commingled with
commercial slack wax compositions to produce lignin-modified slack
wax emulsions. Certain exemplary lignin-modified wax emulsions may
be prepared by intermixing a wax or its components with a surface
tension/interfacial tension reducing agent such as
lignosulphonates, isogenic lignin derivatives, ionogenic detergents
(e.g. sodium dodecyl sulfate and the like), lignin solubilizing
agents (e.g. sodium hydroxide, potassium hydroxide, concentrated
soda solutions), strong nitrogen bases, and the like; and the
present lignin derivatives. Such exemplary emulsions may comprise
at least 20% replacement of solids with the lignin derivatives. The
lignin-modified wax emulsions are preferably stable and provide
bonding and stability performance that is similar to commercial wax
emulsions when applied to wood composites. The levels of lignin
derivatives that may be incorporated into such modified wax
emulsions can be further increased by hydrophobization of the
lignin derivatives by chemical modification or by modified biomass
processing conditions. Such lignin-modified wax emulsions may be
suitable replacements for oil-derived slack wax compositions that
are commonly used for commercial production of wood composite
materials.
[0027] The present invention provides derivatives of native lignin
recovered during or after pulping of lignocellulosic feedstocks.
The pulp may be from any suitable lignocellulosic feedstock
including hardwoods, softwoods, annual fibres, and combinations
thereof.
[0028] Hardwood feedstocks include Acacia; Afzelia; Synsepalum
duloificum; Albizia; Alder (e.g. Alnus glutinosa, Alnus rubra);
Applewood; Arbutus; Ash (e.g. F. nigra, F. quadrangulata, F.
excelsior, F. pennsylvanica lanceolata, F. latifolia, F. profunda,
F. americana); Aspen (e.g. P. grandidentata, P. tremula, P.
tremuloides); Australian Red Cedar (Toona ciliata); Ayna
(Distemonanthus benthamianus); Balsa (Ochroma pyramidale); Basswood
(e.g. T. americana, T. heterophylla); Beech (e.g. F. sylvatica, F.
grandifolia); Birch; (e.g. Betula populifolia, B. nigra, B.
papyrifera, B. lenta, B. alleghaniensis/B. lutea, B. pendula, B.
pubescens); Blackbean; Blackwood; Bocote; Boxelder; Boxwood;
Brazilwood; Bubinga; Buckeye (e.g. Aesculus hippocastanum, Aesculus
glabra, Aesculus flaval/Aesculus octandra); Butternut; Catalpa;
Cherry (e.g. Prunus serotina, Prunus pennylvanica, Prunus avium);
Crabwood; Chestnut; Coachwood; Cocobolo; Corkwood; Cottonwood (e.g.
Populus balsamifera, Populus deltoides, Populus sargentii, Populus
heterophylla); Cucumbertree; Dogwood (e.g. Cornus florida, Cornus
nuttallii); Ebony (e.g. Diospyros kurzii, Dioipyros melanida,
Dimpyros crassiflora); Elm (e.g. Ulmus americana, Ulmus procera,
Ulmus thomasii, Ulmus rubra, Ulmus glabra); Eucalyptus; Greenheart;
Grenadilla; Gum (e.g. Nyssa sylvatica, Eucalyptus globulus,
Liquidambar styraciflua, Nyssa aquatica); Hickory (e.g. Carya alba,
Carya glabra, Carya ovata, Carya laciniosa); Hornbeam; Hophornbeam;
Ip ; Iroko; Ironwood (e.g. Bangkirai, Carpinus caroliniana,
Casuarina equisetifolia, Choricbangarpia subargentea, Copaifira
spp., Eusideroglon zwageri, Guajacum officinale, Guajacum sanctum,
Hopea odorata, Ipe,Krugiodendron ferreum, Lyonothamnus lyonii (L.
floribundus), Mesua ferrea, Olea spp., Olneya tesota, Ostrya
virginiana, Parrotia persica, Tabebuia serratifolia); Jacaranda;
Jotoba; Lacewood; Laurel; Limba; Lignum vitae; Locust (e.g. Robinia
pseudacacia, Gleditsia triacanthos); Mahogany; Maple (e.g. Acer
saccharum, Acer nigrum, Acer negundo, Acer rubrum, Acer
saccharinum, Acer pseudoplatanus); Meranti; Mpingo; Oak (e.g.
Quercus macrocarpa, Quercus alba, Quercus stellata, Quercus
bicolor, Quercus virginiana, Quercus michauxii, Quercus prinus,
Quercus muhlenbergii, Quercus chrysolepis, Quercus lyrata, Quercus
robur, Quercus petraea, Quercus rubra, Quercus velutina, Quercus
laurifolia, Quercus falcata, Quercus nigra, Quercus phellos,
Quercus texana); Obeche; Okoume; Oregon Myrtle; California Bay
Laurel; Pear; Poplar (e.g. P. balsamifera, P. nigra, Hybrid Poplar
(Populus.times.canadensis)); Ramin; Red cedar; Rosewood; Sal;
Sandalwood; Sassafras; Satinwood; Silky Oak; Silver Wattle;
Snakewood; Sourwood; Spanish cedar; American sycamore; Teak; Walnut
(e.g. Juglans nigra, Juglans regia); Willow (e.g. Salix nigra,
Salix alba); Yellow poplar (Liriodendron tulipifera); Bamboo;
Palmwood; and combinations/hybrids thereof.
[0029] For example, hardwood feedstocks for the present invention
may be selected from Acacia, Aspen, Beech, Eucalyptus, Maple,
Birch, Gum, Oak, Poplar, and combinations/hybrids thereof. The
hardwood feedstocks for the present invention may be selected from
Populus spp. (e.g. Populus tremuloides), Eucalyptus spp. (e.g.
Eucalyptus globulus), Acacia spp. (e.g. Acacia dealbata), and
combinations/hybrids thereof.
[0030] Softwood feedstocks include Araucaria (e.g. A. cunninghamii,
A. augustifolia, A. araucana); softwood Cedar (e.g. Juniperus
virginiana, Thuja plicata, Thuja occidentalis, Chamaecyparis
thyoides Callitropsis nootkatensis); Cypress (e.g. Chamaecyparis,
Cupressus Taxodium, Cupressus arkonica, Taxodium distichum,
Chamaecyparis obtusa, Chamaecyparis lawsoniana, Cupressus
semperviren); Rocky Mountain Douglas fir; European Yew; Fir (e.g.
Abies balsamea, Abies alba, Abies procera, Abies amabilis); Hemlock
(e.g. Tsuga canadensis, Tsuga mertensiana, Tsuga heterophylla);
Kauri; Kaya; Larch (e.g. Larix decidua, Larix kaempferi, Larix
laricina, Larix occidentalis); Pine (e.g. Pinus nigra, Pinus
banksiana, Pinus contorta, Pinus radiata, Pinus ponderosa, Pinus
resinosa, Pinus sylvestris, Pinus strobus, Pinus monticola, Pinus
lambertiana, Pinus taeda, Pinus palustris, Pinus rigida, Pinus
echinata); Redwood; Rimu; Spruce (e.g. Picea abies, Picea mariana,
Picea rubens, Picea sitchensis, Picea glauca); Sugi; and
combinations/hybrids thereof.
[0031] For example, softwood feedstocks which may be used herein
include cedar; fir; pine; spruce; and combinations thereof. The
softwood feedstocks for the present invention may be selected from
loblolly pine (Pinus taeda), radiata pine, jack pine, spruce (e.g.,
white, interior, black), Douglas fir, Pinus silvestris, Picea
abies, and combinations/hybrids thereof. The softwood feedstocks
for the present invention may be selected from pine (e.g. Pinus
radiata, Pinus taeda); spruce; and combinations/hybrids
thereof.
[0032] Annual fibre feedstocks include biomass derived from annual
plants, plants which complete their growth in one growing season
and therefore must be planted yearly. Examples of annual fibres
include: flax, cereal straw (wheat, barley, oats), sugarcane
bagasse, rice straw, corn stover, corn cobs, hemp, fruit pulp, alfa
grass, switchgrass, and combinations/hybrids thereof. Industrial
residues like corn cobs, fruit peals, seeds, etc. may also be
considered annual fibres since they are commonly derived from
annual fibre biomass such as edible crops and fruits. For example,
the annual fibre feedstock may be selected from wheat straw, corn
stover, corn cobs, sugar cane bagasse, and combinations/hybrids
thereof.
[0033] The derivatives of native lignin will vary with the type of
process used to separate native lignins from cellulose and other
biomass constituents. Preparations very similar to native lignin
can be obtained by (1) solvent extraction of finely ground wood
(milled-wood lignin, MWL) or by (2) acidic dioxane extraction
(acidolysis) of wood. Derivatives of native lignin can be also
isolated from biomass pre-treated using (3) steam explosion, (4)
dilute acid hydrolysis, (5) ammonia fibre expansion, (6)
autohydrolysis methods. Derivatives of native lignin can be
recovered after pulping of lignocellulosics including industrially
operated kraft, soda pulping (and their modifications) or sulphite
pulping. In addition, a number of various pulping methods have been
developed but not industrially introduced. Among them four major
"organosolv" pulping methods tend to produce highly-purified lignin
mixtures. The first organosolv method uses ethanol/solvent pulping
(aka the Alcell.RTM. process); the second organosolv method uses
alkaline sulphite anthraquinone methanol pulping (aka the "ASAM"
process); the third organosolv process uses methanol pulping
followed by methanol, NaOH, and anthraquinone pulping (aka the
"Organocell" process); the fourth organosolv process uses acetic
acid/hydrochloric acid or formic acid pulping (aka the "Acetosolv"
process).
[0034] It should be noted that kraft pulping, sulphite pulping, and
ASAM organosolv pulping will generate derivatives of native lignin
containing significant amounts of organically-bound sulphur which
may make them unsuitable for certain uses. Acid hydrolysis, soda
pulping, steam explosion, Alcell.RTM. pulping, Organocell pulping,
and Acetosolv pulping will generate derivatives of native lignin
that are sulphur-free or contain low amounts of inorganic
sulphur.
[0035] Organosolv processes, particularly the Alcell.RTM. process,
tend to be less aggressive and can be used to separate highly
purified lignin derivatives and other useful materials from biomass
without excessively altering or damaging the native lignin building
blocks. Such processes can therefore be used to maximize the value
from all the components making up the biomass. Organosolv
extraction processes however typically involve extraction at higher
temperatures and pressures with a flammable solvent compared to
other industrial processes and thus are generally considered to be
more complex and expensive.
[0036] A description of the Alcell.RTM. process can be found in
U.S. Pat. No. 4,764,596 (herein incorporated by reference). The
process generally comprises pulping or pre-treating a fibrous
biomass feedstock with primarily an ethanol/water solvent solution
under conditions that include: (a) 60% ethanol/40% water, (b)
temperature of about 180.degree. C. to about 210.degree. C., (c)
pressure of about 20 atm to about 35 atm, and (d) a processing time
of 5-120 minutes. Derivatives of native lignin are fractionated
from the native lignins into the pulping liquor which also receives
solubilised hemicelluloses, other carbohydrates and other
extractives such as resins, organic acids, phenols, and tannins.
Organosolv pulping liquors comprising the fractionated derivatives
of native lignin and other extractives from the fibrous biomass
feedstocks, are often called "black liquors". The organic acid and
extractives released by organosolv pulping significantly acidify
the black liquors to pH levels of about 5 and lower. After
separation from the cellulosic pulps produced during the pulping
process, the derivatives of native lignin are recovered from the
black liquors by depressurization followed by flashing with cold
water which will cause the fractionated derivatives of native
lignin to precipitate thereby enabling their recovery by standard
solids/liquids separation processes. Various disclosures
exemplified by U.S. Pat. No. 7,465,791 and PCT Patent Application
Publication No. WO 2007/129921, describe modifications to the
Alcell organosolv process for the purposes of increasing the yields
of fractionated derivatives of native lignin recovered from fibrous
biomass feedstocks during biorefining. Modifications to the Alcell
organosolv process conditions included adjusting: (a) ethanol
concentration in the pulping liquor to a value selected from a
range of 35%-85% (w/w) ethanol, (b) temperature to a value selected
from a range of 100.degree. C. to 350.degree. C., (c) pressure to a
value selected from a range of 5 atm to 35 atm, and (d) processing
time to a duration from a range of 20 minutes to about 2 hours or
longer, (e) liquor-to-wood ratio of 3:1 to 15:1 or higher, (f) pH
of the cooking liquor from a range of 1 to 6.5 or higher if a basic
catalyst is used.
[0037] The present invention provides a process for producing
derivatives of native lignin, said process comprising:
[0038] (a) pulping a fibrous biomass feedstock with an organic
solvent/water solution,
[0039] (b) separating the cellulosic pulps or pre-treated
substrates from the pulping liquor or pre-treatment solution,
[0040] (c) recovering derivatives of native lignin.
[0041] The organic solvent may be selected from short chain primary
and secondary alcohols, such as such as methanol, ethanol,
propanol, and combinations thereof. For example, the solvent may be
ethanol. The liquor solution may comprise about 20%, by weight, or
greater, about 30% or greater, about 50% or greater, about 60% or
greater, about 70% or greater, of ethanol.
[0042] Step (a) of the process may be carried out at a temperature
of from about 100.degree. C. and greater, or about 120.degree. C.
and greater, or about 140.degree. C. and greater, or about
160.degree. C. and greater, or about 170.degree. C. and greater, or
about 180.degree. C. and greater. The process may be carried out at
a temperature of from about 300.degree. C. and less, or about
280.degree. C. and less, or about 260.degree. C. and less, or about
240.degree. C. and less, or about 220.degree. C. and less, or about
210.degree. C. and less, or about 205.degree. C. and less, or about
200.degree. C. and less.
[0043] Step (a) of the process may be carried out at a pressure of
about 5 atm and greater, or about 10 atm and greater, or about 15
atm and greater, or about 20 atm and greater, or about 25 atm and
greater, or about 30 atm and greater. The process may be carried
out at a pressure of about 150 atm and less, or about 125 atm and
less, or about 115 atm and less, or about 100 atm and less, or
about 90 atm and less, or about 80 atm and less.
[0044] The fibrous biomass may be treated with the solvent solution
of step (a) for about 1 minute or more, about 5 minutes or more,
about 10 minutes or more, about 15 minutes or more, about 30
minutes or more. The fibrous biomass may be treated with the
solvent solution of step (a) at its operating temperature for about
360 minutes or less, about 300 minutes or less, about 240 minutes
or less, about 180 minutes or less, about 120 minutes or less.
[0045] The pH of the pulp liquor may, for example, be from about 1
to about 6, or from about 1.5 to about 5.5.
[0046] The weight ratio of liquor to biomass may be any suitable
ratio. For example, from about 5:1 to about 15:1, from about 5.5:1
to about 10:1; from about 6:1 to about 8:1.
[0047] The volume of extraction solution is from about 5 to about
10 times the volume of the biomass feedstock. For example, the
volume of extraction solution may be from about 6 to about 8 times
that of the biomass
[0048] The present disclosure provides a process for producing a
lignin derivative having a total hydroxyl content of about 0.1
mmol/g to about 7 mmol/g. Said process comprises: [0049] a) pulping
or pre-treating a fibrous biomass feedstock in a vessel with an
organic solvent/water solution to form a liquor, wherein: [0050] i.
the solution comprises about 30% or greater, by weight, of organic
solvent; and [0051] ii. the pH of the liquor is from about 1 to
about 6; [0052] b) heating the liquor to about 100.degree. C. or
greater; [0053] c) raising the pressure in the vessel to about 5
atm or greater; [0054] d) maintaining the elevated temperature and
pressure for 1 minute or longer; [0055] e) separating the
cellulosic pulps from the pulp liquor
[0056] The present lignin derivatives may comprise alkoxy groups.
For example, the present lignin derivatives may have an alkoxy
content of 2 mmol/g or less; about 1.4 mmol/g or less; about 1.2
mmol/g or less; about 1 mmol/g or less; about 0 8 mmol/g or less;
about 0.7 mmol/g or less; about 0.6 mmol/g or less; about 0.5
mmol/g or less; about 0.4 mmol/g or less; about 0.3 mmol/g or less.
The present lignin derivatives may have an alkoxy content of 0.001
mmol/g or greater, about 0.01 mmol/g of greater, about 0.05 mmol/g
or greater, about 0.1 mmol/g or greater.
[0057] The present lignin derivatives may comprise ethoxyl groups.
For example, the present lignin derivatives may have an ethoxyl
content of 2 mmol/g or less; about 1.4 mmol/g or less; about 1.2
mmol/g or less; about 1 mmol/g or less; about 0.8 mmol/g or less;
about 0.7 mmol/g or less; about 0.6 mmol/g or less; about 0.5
mmol/g or less; about 0.4 mmol/g or less; about 0.3 mmol/g or less.
The present lignin derivatives may have an ethoxyl content of 0.001
mmol/g or greater, about 0.01 mmol/g of greater, about 0.05 mmol/g
or greater, about 0.1 mmol/g or greater.
[0058] The present lignin derivatives may have any suitable
phenolic hydroxyl content such as from about 2 mmol/g to about 8
mmol/g. For example, the phenolic hydroxyl content may be from
about 2.5 mmol/g to about 7 mmol/g; about 3 mmol/g to about 6
mmol/g.
[0059] The present lignin derivatives may have any suitable number
average molecular weight (Mn). For example, the Mn may be from
about 200 g/mol to about 3000 g/mol; about 350 g/mol to about 2000
g/mol; about 500 g/mol to about 1500 g/mol.
[0060] The present lignin derivatives may have any suitable weight
average molecular weight (Mw). For example, the Mw may be from
about 500 g/mol to about 5000 g/mol; about 750 g/mol to about 4000
g/mol; about 900 g/mol to about 3500 g/mol.
[0061] The present lignin derivatives may have any suitable
polydispersity (D). For example, the D may be from about 1 to about
5; from about 1.2 to about 4; from about 1.3 to about 3.5; from
about 1.4 to about 3.
[0062] The present lignin derivatives are preferably hydrophobic.
Hydrophobicity may be assessed using standard contact angle
measurements. In the case of lignin a pellet may be formed using a
FTIR KBr pellet press. Then a water droplet is added onto the
pellet surface and the contact angle between the water droplet and
the lignin pellet is measured using a contact angle goniometer. As
the hydrophobicity of lignins increases the contact angle also
increases. Preferably the lignins herein will have a contact angle
of about 90.degree. or greater. In the case of the use of lignin in
wax emulsions the lignins are preferably very hydrophobic so as to
resemble paraffin and provide maximum water repellent
properties.
[0063] As used herein the term "total hydroxyl content" refers to
the quantity of hydroxyl groups in the lignin derivatives and is
the arithmetic sum of the quantity of aliphatic and phenolic
hydroxyl groups (OHtot=OHal+OHph). OHal is the arithmetic sum of
the quantity of primary and secondary hydroxyl groups
(OHal=OHpr+OHsec). The hydroxyl content can be measured by
quantitative .sup.13C high resolution NMR spectroscopy of
acetylated and non-acetylated lignin derivatives, using, for
instance, 1,3,5-trioxane and tetramethyl silane (TMS) as internal
reference. For the data analysis "BASEOPT" (DIGMOD set to baseopt)
routine in the software package TopSpin 2.1.4 was used to predict
the first FID data point back at the mid-point of .sup.13C r.f.
pulse in the digitally filtered data was used. For the NMR spectra
recording a Bruker AVANCE II digital NMR spectrometer running
TopSpin 2.1 was used. The spectrometer used a Bruker 54 mm bore
Ultrashield magnet operating at 14.1 Tesla (600.13 MHz for .sup.1H,
150.90 MHz for .sup.13C). The spectrometer was coupled with a
Bruker QNP cryoprobe (5 mm NMR samples, .sup.13C direct observe on
inner coil, .sup.1H outer coil) that had both coils cooled by
helium gas to 20K and all preamplifiers cooled to 77K for maximum
sensitivity. Sample temperature was maintained at 300 K.+-.0.1 K
using a Bruker BVT 3000 temperature unit and a Bruker BCU05 cooler
with ca. 95% nitrogen gas flowing over the sample tube at a rate of
800 L/h.
[0064] Quantification of ethoxyl groups was performed similarly to
aliphatic hydroxyls quantification by high resolution .sup.13C NMR
spectroscopy. Identification of ethoxyl groups was confirmed by 2D
NMR HSQC spectroscopy. 2D NMR spectra were recorded by a Bruker 700
MHz UltraShield Plus standard bore magnet spectrometer equipped
with a sensitive cryogenically cooled 5 mm TCI gradient probe with
inverse geometry. The acquisition parameters were as follow:
standard Bruker pulse program hsqcetgp, temperature of 298 K, a
90.degree. pulse, 1.1 sec pulse delay (d1), and acquisition time of
60 msec.
[0065] The present disclosure provides a method of producing a
composite wood product, said method comprising: [0066] a. Obtaining
a cellulosic fibre material; [0067] b. Obtaining an adhesive
suitable for adhering the fibres of said material; [0068] c. Mixing
said cellulosic material with said adhesive, forming the mixture
into a suitable shape and curing; and [0069] d. Applying a wax
composition according to the present disclosure to the shaped
article.
[0070] While the present wax compositions are useful in the
production of composite wood products, they also have other
utilities. For example, the present wax compositions may be used in
paints/lacquers, printing inks, textiles, floor
polishes/protectants, facade protection, wood/timber protection,
mold release, tube drawing, agricultural uses, automotive polishes,
packaging films, temporary protective coatings, food coatings,
metal working, alkali strippable coatings, anti-transpiration,
paper & board (coatings/lubricants, sixing, corrugated board
treatment, transfer papers, wet-strength improvement, printability
improvement), glass lubrication, glass fibre sizing, insecticide
stickers, leather treatment, and the like.
[0071] All citations are herein incorporated by reference, as if
each individual publication was specifically and individually
indicated to be incorporated by reference herein and as though it
were fully set forth herein. Citation of references herein is not
to be construed nor considered as an admission that such references
are prior art to the present invention.
[0072] One or more currently preferred embodiments of the invention
have been described by way of example. The invention includes all
embodiments, modifications and variations substantially as
hereinbefore described and with reference to the examples and
figures. It will be apparent to persons skilled in the art that a
number of variations and modifications can be made without
departing from the scope of the invention as defined in the claims.
Examples of such modifications include the substitution of known
equivalents for any aspect of the invention in order to achieve the
same result in substantially the same way.
[0073] The following examples are intended to be exemplary of the
invention and are not intended to be limiting.
EXAMPLES
Example 1
Preparation of Lignin-Modified Wax Emulsions Using Sodium Hydroxide
as a Solubilizing Agent at Medium Slack Wax Replacement Levels
[0074] An exemplary lignin-modified slack wax emulsion was prepared
with the follow process: [0075] (a) a selected amount of a
Reax.RTM. 85A (Reax is a registered trademark of the MeadWestvaco
Corporation, Glen Allen, Va., USA), a commercial lignosulphonate
(LS) was dissolved in suitable volume of water; [0076] (b) a
selected amount of sodium hydroxide (NaOH) was mixed into the
solution; [0077] (c) a selected amount of a mixture of lignin
derivatives was mixed into the solution; [0078] (d) the solution
was filtered to produce a filtrate; and [0079] (e) the filtrate
then was then mixed into a selected volume of a commercial slack
wax emulsion (EW-58S, Hexion Specialty Chemicals, Columbus, Ohio,
USA) to produce a stable lignin-modified wax emulsion. The EW-58S
wax emulsion contained 58% solids. The lignin derivatives were
produced by organosolv pulping of a batch of aspen chips. The black
liquor generated during the organosolv pulping was separated from
the pulp solids materials, and then was rapidly diluted with cold
water which caused precipitation of lignin derivatives. The lignin
derivatives were separated from the de-lignified liquor and dried
prior to use. The processing conditions and physico-chemical
properties of the lignin derivatives recovered after organosolv
pulping of the aspen wood chips, are shown in Table 1.
TABLE-US-00001 [0079] TABLE 1 Biomass processing parameter Acid (%
odw feed) 0 Cooking time (min) 60 Cooking temperature (.degree. C.)
193 Ethanol concentration in cooking liquor (% wt.) 50 Lignin
derivatives yield (% total native lignin) 60 Characteristics of
lignin derivatives Primary hydroxyl groups (mmol/g) 0.95 Secondary
hydroxyl groups (mmol/g) 0.79 Aliphatic hydroxyl groups (mmol/g)
1.74 Phenolic hydroxyl groups (mmol/g) 4.21 Total hydroxyl groups
(mmol/g) 5.95 Methoxyl groups (mmol/g) 6.32 Ethoxyl groups (mmol/g)
0.68 Syringyl groups (mmol/g) 4.84 Guaiacyl groups (mmol/g) 1.89
Degree of condensation (DC) 33 Number-average molecular weight (Mn,
g/mol) 887 Weight-average molecular weight (Mw, g/mol) 1,808 Z
average molecular weight (Mz, g/mol) 3,650 Polydispersity (D) 2.04
Glass transition point (Tg, .degree. C.) 61 Thermal Flow Index at
105.degree. C. (mm) 24 Thermal Flow Index at 120.degree. C. (mm) 37
Thermal Flow Index at 150.degree. C. (mm) 69 Thermal Flow Index at
180.degree. C. (mm) 82 Melt Flow Index (g lignin derivatives/10 min
measured at ~50 160.degree. C.) Normalized specific Internal bond
strength at 120.degree. C. 2.9 (MPa/cm.sup.2/mg) Normalized
specific Internal bond strength at 150.degree. C. 3.6
(MPa/cm.sup.2/mg)* Normalized specific Internal bond strength at
180.degree. C. 4.9 (MPa/cm.sup.2/mg)* *Measured at 30% replacement
level by a lignin derivative of a commercial OSB phenolic
resin.
[0080] Favourable emulsifying conditions for incorporation of the
lignin derivatives into a slack wax emulsion were achieved. Several
lignin-modified wax emulsion formulations were prepared by
combining solutions produced by following steps (a)-(d) that
incorporated mixtures of lignin derivatives recovered from
different types of hardwood lignocellulosic feedstocks, with the
EW-58S wax emulsion. Several other lignin-modified wax emulsions
were prepared by proportionally increasing the amounts of mixtures
of lignin derivatives incorporated into the EW-58S wax emulsions.
The LS was added to all samples, as a surface tension/interfacial
tension reducing agent, in a fixed amount to yield a final
concentration of 0.03%. A range of solutions with varying
concentrations of NaOH were prepared while mixtures of lignin
derivatives were added in excess (Table 2). Excess lignin
derivatives were filtered out. The remaining supernatants
containing the lignin derivatives were intermixed into the EW-58S
wax emulsions in a 1:1 volume ratio. The solutions were mixed
thoroughly and then left to stand for 24 hrs.
[0081] Modified-lignin wax emulsion samples 1-4 (Table 2) formed a
solid black mass when intermixed into the commercial slack wax
emulsion and produced a non-liquid formulation with limited
suitability for wood composites applications.
TABLE-US-00002 TABLE 2 7.4% NaOH Final Final Final Sample added
Water LS Lignin NaOH LS NaOH ID (mL) (mL) (mL) derivatives(g) (%)
(%) (%) Comments 1 12 0 0 1.0211 5.00 0 5.00 Solid broken 2 10 0 2
1.0519 4.17 0.03 4.17 Solid broken 3 5 5 2 1.0508 2.08 0.03 2.08
Solid broken 4 2.5 7.5 2 0.9732 1.04 0.03 1.04 Solid broken 5 1.25
8.75 2 0.8626 0.52 0.03 0.52 Thick light 6 0.6 9.4 2 1.0217 0.25
0.03 0.25 Normal viscosity lighter 7 0.25 9.75 2 1.0020 0.10 0.03
0.10 Normal viscosity lighter
[0082] Modified-lignin wax emulsion sample 5 (Table 2) formed a
thick coffee brown solution when intermixed into the commercial
slack wax emulsion and produced a non-liquid formulation with
limited suitability for wood composites applications.
[0083] Modified-lignin wax emulsion samples 6 and 7 (Table 2)
formed liquid light brown solutions when intermixed into the
commercial slack wax emulsion, that were stable for several days at
room temperature. These modified-lignin wax emulsions were suitable
for wood composites applications. These modified-lignin wax
emulsions contained about 10-25% wt. of the novel lignin
derivatives.
Example 2
Preparation of Lignin Wax Emulsions with Varying NaOH & LS
Contents
[0084] Modified-lignin wax emulsion samples were produced according
to the recipes shown in Tables 3-6, with the following process
steps: [0085] (a) a solution comprising LS, NaOH and water was
prepared following steps (a)-(b) from Example 1; [0086] (b) a
mixture of lignin derivatives was added to the solution at a ratio
of about 1 g:2 g yielding about 33% lignin (by wt) in the solution;
[0087] (c) the lignin solution was exposed to ultrasound treatments
and mixed thoroughly to produce a black paste; [0088] (d) the black
paste was combined with EW-58S wax emulsion at a ratio of 3:2,
mixed thoroughly, and left to stand for two days at an ambient
temperature.
TABLE-US-00003 [0088] TABLE 3 Preparation of the LS-NaOH solutions
to produce lignin-modified slack wax emulsions with a final LS
concentration of 0.3% Sample 7.4% NaOH Water LS [Final NaOH] ID#
added (mL) (mL) (mL) [Final LS] (%) (%) 1A 2.0 8.0 2.0 0.8 1.23 1B
1.5 8.5 2.0 0.8 0.93 1C 1.0 9.0 2.0 0.8 0.62 1D 0.8 9.2 2.0 0.8
0.49 1E 0.6 9.4 2.0 0.8 0.37 1F 0.4 9.6 2.0 0.8 0.25
TABLE-US-00004 TABLE 4 Preparation of lignin-modified wax emulsions
with a final LS concentration of 0.3% LS- Lignin NaOH deriva- Wax
[Final [Final [Final [Final Sample solution tives emulsion LS]
NaOH] lignin] wax] ID# (g) (g) (0.9 g/mL) (%) (%) (%) (%) 1A2 2.0
1.11 1.8 0.3 0.50 22.6 21.3 1B2 2.0 1.08 1.8 0.3 0.38 22.1 21.4 1C2
2.0 1.04 1.8 0.3 0.25 21.5 21.6 1D2 2.0 1.05 1.8 0.3 0.20 21.6 21.5
1E2 2.0 1.14 1.8 0.3 0.15 23.1 21.1 1F2 2.0 0.97 1.8 0.3 0.10 20.3
21.9
TABLE-US-00005 TABLE 5 Preparation of the LS-NaOH solutions to
produce lignin-modified slack wax emulsions with a final LS
concentration of 1.6% Sample 7.4% NaOH Water LS [Final NaOH] ID#
added (mL) (mL) (mL) [Final LS] (%) (%) 2A 2.0 8.0 2.0 2.3 1.23 2B
1.5 8.5 2.0 3.9 0.93 2C 1.0 9.0 2.0 3.9 0.62 2D 0.8 9.2 2.0 3.9
0.49 2E 0.6 9.4 2.0 3.9 0.37 2F 0.4 9.6 2.0 3.9 0.25
TABLE-US-00006 TABLE 6 Preparation of lignin-modified wax emulsions
with a final LS concentration of 1.6% LS- Lignin NaOH deriva- Wax
[Final [Final [Final [Final Sample solution tives emulsion LS]
NaOH] lignin] wax] ID# (g) (g) (0.9 g/mL) (%) (%) (%) (%) 2A2 2.0
1.03 1.8 1.0 0.51 21.3 21.6 2B2 2.0 0.94 1.8 1.6 0.39 19.8 22.0 2C2
2.0 1.01 1.8 1.6 0.26 21.0 21.7 2D2 2.0 1.14 1.8 1.6 0.20 23.1 21.1
2E2 2.0 1.02 1.8 1.6 0.15 21.2 21.7 2F2 2.0 1.05 1.8 1.6 0.10 21.6
21.5
[0089] Lignin-modified wax emulsion sample ID#s 1A2-1B2 resulted in
black broken emulsions. Lignin-modified wax emulsion sample ID#s
1F2 resulted in a chocolate brown liquid with phase separation.
Lignin-modified wax emulsion sample ID#s 1C2-1E2 conditions yielded
liquid, chocolate brown formulations with evenly distributed
precipitates. Lignin-modified wax emulsions sample ID#1C2 appeared
to be the most homogenous formulation.
[0090] Lignin-modified wax emulsion sample 1D#s 2A2-2B2 resulted in
solid brown/black solid mass, broken emulsion. Lignin-modified wax
emulsion sample ID#2C2 resulted in a slightly thick chocolate brown
solution with precipitates, and showed some phase separation.
Lignin-modified wax emulsion sample ID#s 2D2-2F2 resulted in a
chocolate brown formulation containing some evenly distributed
precipitates and particulate matter. Lignin-modified wax emulsion
sample ID#1C2 yielded the best result formulation comprising a
stable and uniform emulsion at 0.3% LS. The best formulation with a
1.6% LS final concentration was the lignin-modified wax emulsion
sample ID#2C2 which had a slightly thicker composition in
comparison to the series of wax emulsions produced with a 0.3% LS
final concentration.
[0091] The optimal range of final NaOH concentrations was found to
be about 0.25% to about 0.15% for the 0.3% LS series, and the
optimal range of final NaOH concentrations in the 1.6% LS series
was about 0.26% to about 0.10%.
[0092] The addition of excess NaOH appeared to break-down the
lignin-modified wax emulsion into separated phases, although the
lignin derivatives remained in solution. Lower final NaOH
concentrations did not yield stable lignin-modified slack wax
formulations in view of the particle aggregation that was observed
in those compositions. The addition of the LS facilitated stable
lignin-modified slack wax formulations. However, combinations of
higher concentrations of both LS and NaOH resulted in thicker wax
emulsions that are not particularly suitable for the manufacture of
wood composite materials.
[0093] In this example, the concentrations of LS incorporated into
the compositions were relatively higher compared to those used in
Example #1, but were kept constant among a given dilution series
(Tables 3 and 5). The final concentration achieved of LS was 0.3%
for the first dilution series (Table 4) and 1.6% for the second
dilution series (Table 6). Both dilution series were otherwise
identical. The final NaOH concentration in the emulsions ranged
from 0.1% to 0.5%. The concentration of lignin derivative mixtures
was about 22% of the total final formulations. The final
concentration of solids in the lignin-modified wax emulsions
produced in this example was around 45% with the lignin derivatives
comprising about half of the emulsions and the remainder comprising
the commercial slack wax.
[0094] The increase in the lignin derivatives content produced
stable wax emulsions suitable for use in production of OSB
materials.
Example 3
Preparation of Lignin-Modified Wax Emulsions with Varying LS and
Lignin Derivatives Contents
[0095] Fifty-mL samples of modified-lignin wax emulsion samples
were produced according to the recipes shown in Tables 7-10,
following process steps outlined in Example 2. A first series was
prepared wherein the final solids content in the modified-lignin
wax emulsions was 54% solids, with approximately half comprising
novel lignin derivatives solubilized and recovered from a hardwood
lignocellulosic feedstock.
[0096] A second series was prepared wherein the final solids
content in the modified-lignin wax emulsions was 56%, with 25% of
that comprising the novel lignin derivatives.
TABLE-US-00007 TABLE 7 Preparation of the LS-NaOH solutions to
produce lignin-modified slack wax emulsions with a final LS
concentration of 1.0%, and comprising about 50% lignins. 7.4% NaOH
Water LS [Final NaOH] ID# added (mL) (mL) (mL) [Final LS] (%) (%)
1C 1.0 9.0 2.0 3.9 0.62 2C 1.0 9.0 2.0 3.9 0.62 2D 0.8 9.2 2.0 3.9
0.49 2E 0.6 9.4 2.0 3.9 0.37
TABLE-US-00008 TABLE 8 Preparation of lignin-modified wax emulsions
with a final LS concentration of about 1% LS- Lignin NaOH deriva-
Wax [Final [Final [Final [Final solution tives emulsion LS] NaOH]
lignin] wax] ID# (g) (g) (0.9 g/mL) (%) (%) (%) (%) 1C3 12.00 12.31
26.11 0.9 0.20 24.4 30.0 2C3 12.64 12.53 24.52 1.0 0.16 25.2 28.6
2D3 12.18 11.93 25.16 1.0 0.12 24.2 29.6 2E3 12.19 11.76 24.44 1.0
0.09 24.3 29.3
TABLE-US-00009 TABLE 9 Preparation of the LS-NaOH solutions to
produce lignin- modified slack wax emulsions with a final LS
concentration of 1.0%, and comprising about 25% lignins. LS- Lignin
NaOH deriva- Wax [Final [Final [Final [Final solution tives
emulsion LS] NaOH] lignin] wax] ID# (g) (g) (0.9 g/mL) (%) (%) (%)
(%) 1C5 6.01 6.11 36.97 0.5 0.15 12.4 43.7 2C5 6.12 6.12 36.79 0.5
0.12 12.5 43.5 2D5 6.03 5.91 37.45 0.5 0.12 12.0 44.0 2E5 6.01 6.11
36.97 0.5 0.12 12.4 43.7
TABLE-US-00010 TABLE 10 Preparation of lignin-modified wax
emulsions with a final LS concentration of 1.0%, and comprising
about 25% lignins. Wax [Final [Final [Final [Final Final Total %
lignin % lignin LS (g) LS-NaOH Lignin emulsion LS] NaOH] lignin]
wax] Mass solids of total of total (1 mL/g) soln (g) deri. (g) (0.9
g/mL) (%) (%) (%) (%) (g) (%) solids solids 2D11 117.27 0 116.34
240.0 1.0 0.12 24.6 29.4 6.01 6.11 36.97 0.5
[0097] All of the samples produced with the recipes shown in Tables
7-10 comprised liquid lignin-modified slack wax emulsions.
Lignin-modified wax emulsion sample ID#s 1C3-2E3 (.about.50:50
lignin/wax) were liquid and were about the same chocolate brown
color. All samples had visually detectable particles distributed
throughout emulsions. Lignin-modified wax emulsion sample ID#s
105-2E5 (.about.25/75 lignin/wax) were almost identical in color.
These samples were of a grey/brown color that was significantly
lighter than the color of lignin-modified wax emulsion sample ID#s
1C3-2E3.
[0098] The preceding examples exemplify methods of the present
invention for preparing lignin-modified wax emulsions comprising
lignin derivatives solubilized during and recovered from organosolv
pulping of lignocellulosic biomass sources.
Example 4
OSB Panels Prepared with a Lignin-Modified Wax Emulsion
[0099] Lignin-modified wax emulsion sample ID#s 2D5 and 2D11 were
prepared in 250-mL volumes following the process steps outlined in
Example 3, and were used for production of OSB panels. Three types
of homogenous OSB panels were produced in triplicate using aspen
strands as the feedstock. The strands were screened to remove fines
and then dried to about 2% moisture content prior to blending with
a commercial liquid OSB face phenol-formaldehyde resin (EW-58S
emulsion). The EW-58S emulsion was added at 3% (dry wood basis).
The target moisture content of strands after blending was 5.5%. The
commingled aspen strand--EW-58S emulsion was passed through a
conventional press set at a target density of 40 lb/ft.sup.3 to
produce panels having a thickness of 0.4375 inches.
[0100] The first set of three OSB panels were the controls produced
with the EW-58S emulsion with the following process steps: [0101]
(a) aspen strands were screened to remove fines; [0102] (b) 14 kg
aspen strands were dried to about 2% moisture content (MC); [0103]
(c) the liquid PF resin OSF-59LFM was warmed to 25.degree. C.;
[0104] (d) the blending was conducted using the following
parameters:
[0105] strands: 14 kg dry Aspen/blend (2% MC)
[0106] wax emulsion: 241 g EW-58S
[0107] phenol-formaldehyde resin: (59% solids): 711 g of OSF-59FLM
resin [0108] (e) resinated furnish was checked for moisture
content. [0109] (f) each mat was formed manually with care to
ensure even density distribution across the face of each panel.
[0110] (g) each panel was pressed with the following
parameters:
[0111] weight of dispensed materials: 3665 g/mat
[0112] dimensions: 28''.times.28''.times. 7/16''
[0113] density: 40 lb/f.sup.3
[0114] press temperature: 210.degree. C.
[0115] press time: 4 minutes [0116] (h) the control OSB panels were
labeled C1-C3
[0117] The second set of three OSB panels were produced following
the same process steps listed for the control OSB panels except
that the wax emulsion in step (d) was substituted with
lignin-modified wax emulsion sample ID#2D11 (50%:50% lignol:wax
ratio). The three OSB panels produced with lignin-modified wax
emulsion sample ID#2D5, were labeled E5-E7.
[0118] The third set of three OSB panels were produced following
the same process steps listed for the control OSB panels except
that the wax emulsion in step (d) was substituted with
lignin-modified wax emulsion sample ID#2D5 (25%:75% lignol:wax
ratio). The three OSB panels produced with lignin-modified wax
emulsion sample ID#2D5, were labeled E1-E3.
[0119] Each of the three panels from each blend was tested for: (a)
density, (b) internal bond strength (IB), (c) bond durability using
MOR and MOE determinations (MOR=modulus of rupture; MOE=modulus of
elasticity), (d) thickness swell and water absorption after (i) a
24-hour submerged water soaking, and (ii) a 2-hour period of
boiling in water. The above tests were conducted following the
Canadian Standard #0437.1-93 Test Methods for OSB and Waferboard
(ISSN 0317-5669, published in April 1993 by Canadian Standards
Association, Toronto, ON, Canada). The testing results are shown in
Tables 11-13.
TABLE-US-00011 TABLE 11 Internal bond Panel density IB density
strength TSWA* density Panel ID # (lb/ft.sup.3) (lb/ft.sup.3) (MPa)
(lb/ft.sup.3) C1 41.0 42.6 0.256 43.5 C2 40.0 38.8 0.216 41.8 C3
39.9 40.6 0.238 40.0 C1-C2 mean 40.3 40.7 0.237 41.8 E1 40.3 39.7
0.212 42.0 E2 39.6 38.9 0.206 41.4 E3 40.2 40.5 0.266 42.2 E1-E3
mean 40.0 39.7 0.228 41.9 E5 39.5 39.2 0.139 41.4 E6 39.6 37.1
0.155 40.1 E7 39.5 39.9 0.132 42.7 E5-E7 mean 39.5 38.7 0.142 41.4
*TSWA is "Thickness swell and water absorption".
TABLE-US-00012 TABLE 12 % thickness % water % thickness % water
swelling absorption swelling absorption (24-h soak + (24-h soak +
Panel ID # (24-h soak) (24-h soak) 2-h boil) 2-h boil) C1 20.3 30.3
75.3 142.3 C2 20.2 31.5 66.4 141.6 C3 19.8 31.6 64.1 142.9 C1-C2
mean 20.1 31.1 68.6 142.3 E1 20.0 31.5 65.0 141.8 E2 22.9 34.1 72.0
141.6 E3 23.7 34.3 67.7 140.6 E1-E3 mean 22.2 33.3 68.2 143.1 E5
26.7 41.5 78.3 150.4 E6 30.0 44.7 79.2 155.8 E7 29.5 41.1 87.4
153.2 E5-E7 mean 28.7 42.4 81.6 153.1
TABLE-US-00013 TABLE 13 Wet Dry bending Dry Dry Wet bending bending
density MOR MOE density MOR Panel ID # (lb ft.sup.3) (MPa) (MPa)
(lb ft.sup.3) (MPa) C1 40.9 30.40 4596 41.3 11.99 C2 41.4 25.75
3824 39.9 9.25 C3 42.0 32.22 4510 38.5 9.25 C1-C2 mean 41.4 29.46
4310 39.9 10.16 E1 42.6 31.72 4971 40.8 11.60 E2 40.7 26.16 3670
40.4 11.56 E3 40.9 33.22 4061 40.2 11.00 E1-E3 mean 41.4 30.37 4234
40.5 11.39 E5 39.7 22.86 3823 39.4 4.99 E6 41.7 26.51 3984 40.4
6.81 E7 40.0 22.16 3580 39.5 6.37 E5-E7 mean 40.5 23.84 3796 39.8
6.06
[0120] OSB panels prepared with lignin-modified wax emulsion sample
ID#2D5 (i.e., panels E1-E3) performed similarly to OSB panels
prepared with the commercial slack wax EW-58S (i.e., panels C1-C3).
Lignin-modified wax emulsion sample ID#2D5 comprised a 25%:75%
lignol:wax ratio. These data indicate that 25% of a commercial
slack wax emulsion used for production of OSB materials, can be
replaced with lignin derivatives.
* * * * *