MODIFIED LIGNINS

LIGNINES MODIFIEES

English Abstract

Ligning and polyether glycol produces a product which has a distinct melt
point and melt viscosity. This has a plasticizing effect wherein the polyether
glycol can be thought of as the hard resin. When 20 parts of polyether glycol
are processed with 80 parts of lignin a new material which has a melt point
and a viscosity is created whereas lignin itself has no melt and flow
characteristics. The new modified lignin can be cured with hexamine like a
phenolic resin.

French Abstract

On obtient en mélangeant de la lignine et du glycol de polyéther un produit qui possède un point de fusion et une viscosité à l'état fondu caractéristiques. Ceci se traduit par un effet plastifiant qui fait que le glycol de polyéther peut être considéré comme la résine dure. Lorsqu'on mélange 20 parts de glycol de polyéther et 80 parts de lignine, on obtient une nouvelle matière possédant un point de fusion et une caractéristique de viscosité alors que la lignine seule ne possède aucune caractéristique de fusion ou de fluidité. Il est possible de polymériser la nouvelle lignine modifiée avec une hexamine comme une résine phénolique.

Claims

4
what is claimed is:
1. A composition comprising lignin blended with a polyether
compound to improve the melt and flow characteristics of the
lignin, said lignin having a sodium level less than 22% by
weight of sodium.
2. A composition as claimed in claim 1 wherein the
percentage of said polyether compound is from 1% to 70% of
the composition.
3. A composition comprising lignin blended with a polyester
compound to improve the melt and flow characteristics of the
lignin, said lignin having a sodium level less than 22% by
weight of sodium.
4. A composition as claimed in claim 3 wherein the
percentage of said polyester compound is from 1% to 70% of
the composition.
5. A composition as claimed in claim 1 wherein said
polyether compound is produced by a reaction involving at
least one of ethylene oxide and propylene oxide.
6. A composition comprising lignin and blended with a
combination of polyester resins and polyether glycols to
improve the melt and flow characteristics of the lignin, said
lignin having a sodium level less than 22% by weight of
sodium.
7. A composition comprising a polyether derivative (derived
from at least one of ethylene oxide and propylene oxide)
which is initiated by a chemical selected from the group
consisting of nonlyphenol, phenol and a substituted phenol
blended with lignin to improve the melt and flow
characteristics of lignin, said lignin having a sodium level

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less than 22% by weight of sodium.
8. A composition as claimed in claim 1 wherein the modified
lignin is reacted with hexamine to produce a cured product.
9. A composition as claimed in claim 3 wherein the modified
lignin is reacted with hexamine to produce a cured product.
10. A composition as claimed in claim 6 wherein the modified
lignin is reacted with hexamine to produce a cured product.
11. A composition as claimed in claim 7 wherein the modified
lignin is reacted with hexamine to produce a cured product.

Description

CA 02262940 1999-02-03
WO 98/08903 PCT/US97/15039
MODIFIED LIGNINS
There are substantial markets available to lignins if they can
achieve the same melt and flow characteristics as a phenolic resin. There are
at least two major factors of this present invention which allow these new
modified lignins to be able to totally replace phenolic resins. The first
factor
that has been that a lignin which does not have any distinct melt point or
flow
characteristics can be modified with a certain amount of polyether glycol to
achieve a certain desired melt point. So, what occurs is a certain ratio of
lignin to a polyether compound (such as polyether glycol) produces a
product which has a distinct melt point and melt viscosity. This effect can be
thought of as a type of plasticizing effect wherein the lignin can be thought
of
as the hard resin. For example, when 20- parts of a polyether glycol is
properly processed with 80 parts of lignin what results is a new material
which now has melt and flow characteristics, whereas lignin by itself has no
melt and flow characteristics. Because these melt and flow characteristics are
similar to a phenoiic resin these new modified lignins can be cured with
hexamine just like a phenolic resin. This is because the lignin molecule
contains phenolic groups which are reactive to hexamine just as in a phenolic
resin. This is significant because although lignin itself does contain
phenolic
groups that are reactive to hexamine the fact that the lignin molecule does
not
melt and flow means that it would be almost impossible to obtain a
commercially moldable part from a press with heat and pressure.
Another major advantage of this present invention is that lignin
is derived from wood, which is a natural product. As in all natural products
there will exist a certain amount of variation depending on the exact type of
wood, age and other conditions. These variations are another major reason
why lignins have not been extensively utilized as replacements for phenolic
resins, whereas a synthetic phenolic resin can be made to exact and
SUBSTITUTE SHEET {RULE 26)

CA 02262940 2001-11-20
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reproducible specifications, and the lignin molecule may have wide
variations. Therefore, if there is a variation in the lignin this
can be adjusted by changing the ratio of lignin to a polyether
compound (such as polyether glycol) in order to achieve the desired
melt and flow characteristics.
Another aspect of this invention that has a synergistic
effect on the melt and flow characteristics in the sodium level of
the lignin. It was discovered that if the sodium level is too high
the modified lignin will not have melt and flow characteristics
which can be utilized as a commercial product. It was found that
the same lignin, but with different sodium levels, will produce
modified lignins with wide variations in melt and flow
characteristics. Therefore, it was discovered that there is a
certain critical level for the presence of sodium and other ionic
materials above which no useful products could be obtained. This
critical level may vary depending on the specific nature or
chemical composition of the lignins. In general, experimentation
has determined that the sodium level of lignin should preferably be
less than 22 percent by weight of sodium.
Another major invention is the fact that lignins are a
natural product and as such there may be natural chemical
variations in the lignin molecule. These variations may include
different functional groups or different concentrations of these
functional groups. These variations become rather significant when
you are trying to formulate a product that must have, in addition
to certain physical properties such as melt and flow, certain
curing characteristics in order to produce a consistent product day
in and day out.
If there is a variation in the lignin, then this variation
can be accommodated by changing the ratio of lignin to a polyether
compound (such as polyether glycol) in order to achieve the desired
melt and flow characteristics. Preferably, the ratio of the
polyether compound to lignin is from 1 percent to 70 percent. The
polyether compound can be made from the reaction of propylene oxide
or ethylene oxide with alcohols, amines, nonylphenol, phenol or any
phenolic compound.

CA 02262940 2001-11-20
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These curing characteristics are very important because in
addition to the physical properties of the product they also
determine the productivity, which directly affects how profitable
the product will be. One major market for lignins is to either
partially or totally replace phenolic resins in many products that
currently use all phenolic resins. There are at least two major
advantages why lignins can be used as either partial or total
replacement of phenolic resins in phenolic production. One major
advantage is that lignins can offer significant economic
advantages. Since most phenolic resins are made from phenol and
phenol is a petrochemical product, cost of phenol is very dependent
on the cost of oil. So, as the cost of oil increases, the cost of
phenol and phenolic resins will also increase. These price
increases could make phenolic resins less competitive and thereby
make it possible for these phenolic products to be replaced by
other products. Therefore, when more lignin can be incorporated
into a phenolic product, this could offset price increases and make
these lignin modified phenolic products more profitable and more
competitive, thus increasing their market share.
EXAMPLE I
In a suitable vessel 20 parts of Pluracol P-410r"" is heated to
200°F and 80 parts of lignin is slowly added while adequate
agitation is maintained and the heat slowly increased to 200°F.
The viscosity of this mixture will increase significantly but it
still is able to b mixed. Then once all of the lignin is added,
the mixture is continued to be mixed until everything is
homogeneous. Then this mixture is poured out on to a surface which
allows this mixture to cool and form a hard brittle material. This
lignin is now in a form which is very similar to phenolic resins.
This modification of the lignin now makes it possible for it to
have melt and flow characteristics.