U.S. patent application number 10/093970 was filed with the patent office on 2002-11-28 for process for stabilizing the whiteness of lignin-containing fibrous materials, stabilizer composition and fibrous materials stabilized with this.
Invention is credited to Baurich, Christian, Beyer, Mario, Fischer, Klaus, Jakob, Harald, Koch, Helmut, Krasselt, Karsten, Suss, Hans Ulrich.
Application Number | 20020174491 10/093970 |
Document ID | / |
Family ID | 7677319 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020174491 |
Kind Code |
A1 |
Fischer, Klaus ; et
al. |
November 28, 2002 |
Process for stabilizing the whiteness of lignin-containing fibrous
materials, stabilizer composition and fibrous materials stabilized
with this
Abstract
Lignin-containing fibrous materials, in particular paper and
card, are treated with whiteness stabilizers for the purpose of
reducing light-induced yellowing. The whiteness stabilizer are (i)
thiols with at least one additional hydrophilic group from the
series consisting of OH, NH.sub.2, NHR.sup.1m NR.sup.1R.sup.2,
COOH, SO.sub.3H and PO.sub.3H.sub.2 and an amino acid/peptide
structure (ii) thiols with a CC double bond (iii) or heteroaromatic
thiols and (iv), heteroaromatic disulfides or polysulfides. HALS
light stabilizers and/or UV stabilizers are advantageously
additionally employed. The stability is increased further by a
TiO.sub.2-containing coat on the fibrous material. Stabilzer
compositions and fibrous material stabilized according to the
invention, containing a whiteness stabilizer of group (i) to (iv)
are also disclosed.
Inventors: |
Fischer, Klaus;
(Grillenburg, DE) ; Beyer, Mario; (Kurort Hartha,
DE) ; Koch, Helmut; (Dresden, DE) ; Krasselt,
Karsten; (Coschutz, DE) ; Baurich, Christian;
(Kurort Hartha, DE) ; Jakob, Harald; (Hasselroth,
DE) ; Suss, Hans Ulrich; (Hasselroth, DE) |
Correspondence
Address: |
SMITH, GAMBRELL & RUSSELL, LLP
ATTORNEYS AT LAW
SUITE 800
1850 M STREET, N.W.
WASHINGTON
DC
20036
US
|
Family ID: |
7677319 |
Appl. No.: |
10/093970 |
Filed: |
March 11, 2002 |
Current U.S.
Class: |
8/115.51 |
Current CPC
Class: |
D21H 21/143
20130101 |
Class at
Publication: |
8/115.51 |
International
Class: |
D06M 010/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2001 |
DE |
101 12 101.6 |
Claims
We claim:
1. A process for stabilizing the whiteness of a lignin-containing
fibrous material against light-induced yellowing, comprising
contacting said fibrous material with a thio compound as a
whiteness stabilizer in an active amount for increasing the
resistance to yellowing during the production of the fibrous
material, said thio compound being selected from the group
consisting of (i) a thiol which has at least one aliphatically or
cycloaliphatically bonded thiol group and additionally at least one
further hydrophilic group selected from the group consisting of
--OH, --NH.sub.2, --NHR.sup.1, --NR.sup.1R.sup.2, wherein R.sup.1
and R.sup.2 represent C.sub.1- to C.sub.4-alkyl or C.sub.2 to
C.sub.4-hydroxyalkyl, C.sub.2- to C.sub.4-alkanoyl- or
-hydroxyalkanoyl, or together represent cycloalkyl, or --COOH,
--SO.sub.3H and --PO.sub.3H.sub.2 and salts of the acid and base
function, (ii) a thiol which contains at least one aliphatically or
cycloaliphatically bonded thiol group and additionally at least one
CC double bond, (iii) a thiol which contains at least one thiol
group bonded to a heteroaromatic, and (iv) a di- and polysulfide
with at least one heteroaromatic bonded to the di-/polysulfide
group, with the proviso that thioglycerol, dithiothreitol
mercaptoacetic acid, 2- and 3-mercaptopropionic acid, and salts
thereof are excluded as the whiteness stabilizer.
2. The process according to claim 1, wherein the fibrous material
is selected from the group consisting of substantially
mechanically, thermomechanically or chemo-thermomechanically
produced lignin-containing unbleached and bleached fibrous
substances and mixtures thereof.
3. The process according to claim 2 wherein the fibrous material is
paper or card from wood pulp.
4. The process according to claim 1 further comprising adding said
whiteness stabilizer to pulp of the fibrous material or to a size
or brush-on color composition to be applied to a fibrous material,
or a solution or suspension of a composition comprising the
whiteness stabilizer is sprayed on to non-coated fibrous
material.
5. The process according to claim 2 further comprising adding said
whiteness stabilizer to pulp of the fibrous material or to a size
or brush-on color composition to be applied to a fibrous material,
or a solution or suspension of a composition comprising the
whiteness stabilizer is sprayed on to non-coated fibrous
material.
6. Process according to claim 1 further comprising adding to the
fibrous material in addition to said thiol compound whiteness
stabilizer or co-stabilizer selected from the group consisting of
UV absorber, antioxidant, a metal deactivator, agent which trap
free radicals, fluorescent brightener, phosphite, reducing agent
and aromatic sulfide.
7. Process according to claim 2 further comprising adding to the
fibrous material in addition to said thiol compound whiteness
stabilizer or co-stabilizer selected from the group consisting of
UV absorber, antioxidant, a metal deactivator, agent which trap
free radicals, fluorescent brightener, phosphite, reducing agent
and aromatic sulfide.
8. Process according to claim 4 further comprising adding to the
fibrous material in addition to said thiol compound whiteness
stabilizer or co-stabilizer selected from the group consisting of
UV absorber, antioxidant, a metal deactivator, agent which trap
free radicals, fluorescent brightener, phosphite, reducing agent
and aromatic sulfide.
9. The process according to claim 1 wherein a fibrous material
treated with a whiteness stabilizer in the pulp, in a surface
coating or by means of impregnation is coated with a brush-on color
comprising titanium dioxide, or a non-treated fibrous material is
coated with a brush-on color comprising a whiteness stabilizer and
titanium dioxide.
10. The process according to claim 2 wherein a fibrous material
treated with a whiteness stabilizer in the pulp, in a surface
coating or by means of impregnation is coated with a brush-on color
comprising titanium dioxide, or a non-treated fibrous material is
coated with a brush-on color comprising a whiteness stabilizer and
titanium dioxide.
11. The process according to claim 4 wherein a fibrous material
treated with a whiteness stabilizer in the pulp, in a surface
coating or by means of impregnation is coated with a brush-on color
comprising titanium dioxide, or a non-treated fibrous material is
coated with a brush-on color comprising a whiteness stabilizer and
titanium dioxide.
12. The process according to claim 6 wherein a fibrous material
treated with a whiteness stabilizer in the pulp, in a surface
coating or by means of impregnation is coated with a brush-on color
comprising titanium dioxide, or a non-treated fibrous material is
coated with a brush-on color comprising a whiteness stabilizer and
titanium dioxide.
13. The process according to claim 1 wherein said thiol (i) is an
ester of a polyhydric alcohol selected from the group consisting of
ethylene glycol, di-, tri- and polyethylene glycol, propane-1,2-
and 1,3-diol, butane-1,4-diol, hexane-1,2,6-triol,
trimethylolethane (TME), trimethylolpropane (TMP), erythritol,
pentaerythritol (penta), di-TME, di-TMP, di-penta, sugar alcohols,
sugar acids and lactones thereof and water-soluble polymeric
alcohols, with a mercaptocarboxylic acid selected from the group
consisting of mercaptoacetic acid (=thioglycollic acid), 2- and
3-mercaptopropionic acid, mono- and dimercaptosuccinic acid,
wherein at least one hydroxyl group of the polyhydric alcohol is
non-esterified.
14. The process according to claim 2 wherein said thiol (i) is an
ester of a polyhydric alcohol selected from the group consisting of
ethylene glycol, di-, tri- and polyethylene glycol, propane-1,2-
and 1,3-diol, butane-1,4-diol, hexane-1,2,6-triol,
trimethylolethane (TME), trimethylolpropane (TMP), erythritol,
pentaerythritol (penta), di-TME, di-TMP, di-penta, sugar alcohols,
sugar acids and lactones thereof and water-soluble polymeric
alcohols, with a mercaptocarboxylic acid selected from the group
consisting of mercaptoacetic acid (=thioglycollic acid), 2- and
3-mercaptopropionic acid, mono- and dimercaptosuccinic acid,
wherein at least one hydroxyl group of the polyhydric alcohol is
non-esterified.
15. The process according to claim 4 wherein said thiol (i) is an
ester of a polyhydric alcohol selected from the group consisting of
ethylene glycol, di-, tri- and polyethylene glycol, propane-1,2-
and 1,3-diol, butane-1,4-diol, hexane-1,2,6-triol,
trimethylolethane (TME), trimethylolpropane (TMP), erythritol,
pentaerythritol (penta), di-TME, di-TMP, di-penta, sugar alcohols,
sugar acids and lactones thereof and water-soluble polymeric
alcohols, with a mercaptocarboxylic acid selected from the group
consisting of mercaptoacetic acid (=thioglycollic acid), 2- and
3-mercaptopropionic acid, mono- and dimercaptosuccinic acid,
wherein at least one hydroxyl group of the polyhydric alcohol is
non-esterified.
16. The process according to claim 6 wherein said thiol (i) is an
ester of a polyhydric alcohol selected from the group consisting of
ethylene glycol, di-, tri- and polyethylene glycol, propane-1,2-
and 1,3-diol, butane-1,4-diol, hexane-1,2,6-triol,
trimethylolethane (TME), trimethylolpropane (TMP), erythritol,
pentaerythritol (penta), di-TME, di-TMP, di-penta, sugar alcohols,
sugar acids and lactones thereof and water-soluble polymeric
alcohols, with a mercaptocarboxylic acid selected from the group
consisting of mercaptoacetic acid (=thioglycollic acid), 2- and
3-mercaptopropionic acid, mono- and dimercaptosuccinic acid,
wherein at least one hydroxyl group of the polyhydric alcohol is
non-esterified.
17. The process according to claim 9 wherein said thiol (i) is an
ester of a polyhydric alcohol selected from the group consisting of
ethylene glycol, di-, tri- and polyethylene glycol, propane-1,2-
and 1,3-diol, butane-1,4-diol, hexane-1,2,6-triol,
trimethylolethane (TME), trimethylolpropane (TMP), erythritol,
pentaerythritol (penta), di-TME, di-TMP, di-penta, sugar alcohols,
sugar acids and lactones thereof and water-soluble polymeric
alcohols, with a mercaptocarboxylic acid selected from the group
consisting of mercaptoacetic acid (=thioglycollic acid), 2- and
3-mercaptopropionic acid, mono- and dimercaptosuccinic acid,
wherein at least one hydroxyl group of the polyhydric alcohol is
non-esterified.
18. The process according to claim 6, wherein said ester is a di-
or triester of pentaerythritol with mercaptoacetic acid or 1 or
2-mercaptopropionic acid, or a di-, tri- or tetraester of a
pentitol or hexitol.
19. The process according to claim 18 wherein the ester is selected
from the group consisting of pentaerythritol trithiolglycollate
said sorbitol tetrathioglycollate.
20. The process according to claim 1 wherein said thiol compound is
an ester of an alcohol with an allyl structural element, with a
mercaptocarboxylic acid having 2 to 4 C atoms.
21. The process according to claim 20 wherein said ester is
cinnamyl alcohol thioglycollate.
22. The process according to claim 1 wherein the compound is a
mercapto-s-triazine, mercapto-triazole, mercapto-diazole,
mercapto-1,3,4-thiadiazole compound,
2-mercapto-4,6-diamino-s-trazine, wherein the amino groups can be
substituted by alkyl, cycloalkyl or alkyl.
23. The process according to claim 1 wherein the thiol compound is
a compound selected from the group consisting of 2-amino-4,6-bis
polysulfido-s-triazine, bis-4,6-diamino-s-triazin-2-yl
tetrasulfide, bis-5-amino-1,3,4-triadiazol-2-yl di- and
tetrasulfide, wherein the amino groups can in each case be alkyl-,
cycloalkyl- or allyl-substituted.
24. The process according to claim 1 wherein the thiol an amino
acid containing thiol groups, an N-acylated amino acid containing
thiol groups, or an oligopeptide containing thiol groups.
25. The process according to claim 24 wherein the compound is
selected from the group consisting of cysterine, N-acetylcysterine
and glutathione.
26. Whiteness-stabilized lignin-containing fibrous material, of
mechanically produced, thermomechanically, chemo-thermomechanically
wood pulp or high-yield cellulose, containing a whiteness
stabilizer selected from the group consisting of the thiols, di-
and polysulfides according to groups (i) to (iv) of claim 1 in at
least one of the pulp of the fibrous material and in a layer
produced by impregnation, sizing or by a brush-on color.
27. Whiteness-stabilized lignin-containing fibrous material
according to claim 26, wherein the fibrous substance is a bleached
wood pulp or high-yield cellulose.
28. Whiteness-stabilized lignin-containing fibrous material
according to claim 26 which has a coating of a size or coating
color comprising titanium dioxide.
29. Whiteness-stabilized lignin-containing fibrous material
according to claim 27 which has a coating of a size or coating
color comprising titanium dioxide.
30. Whiteness-stabilized lignin-containing fibrous material
according to claim 26 further comprising in the pulp and/or in a
layer produced by impregnation and/or coating, one or more other
whiteness stabilizers and/or co-stabilizers selected from the group
consisting of agents which trap free radicals, UV absorbers
fluorescent brighteners, antioxidants, metal deactivators, reducing
agents, phosphites and other aromatic sulfides.
31. A composition comprising a whiteness stabilizer, characterized
by a content of at least one whiteness stabilizer according to
claim 1, in an aqueous, organic or aqueous-organic liquid or
paste-like medium which can be used for spraying or coating.
32. A composition comprising a whiteness stabilizer, characterized
by a content of at least one whiteness stabilizer according to
claim 13, in an aqueous, organic or aqueous-organic liquid or
paste-like medium which can be used for spraying or coating.
33. Composition according to claim 31, further comprising one or
more other whiteness stabilizers and/or co-stabilizers selected
from the group consisting of agents which trap free radicals,
antioxidants, UV absorbers, reducing agents, fluorescent
brighteners, metal deactivators, phosphites and aromatic
sulfides.
34. Composition according to claim 31 further comprising a HALS
light stabilizer, and/or an antioxidant from the series consisting
of sterically hindered phenols.
35. The composition according to claim 34 containing 2,2,6,6
tetramethyl-4-hydroxypiperidine N-oxide, and/or a
2-hydroxyaryl-benzotria- zole a hydroxybenzophenone or a
2-substituted 3-(hydroxyaryl)acrylic acid ester.
36. Composition according to claim 34 additionally comprising a
HALS light stabilizer and a UV absorber in a weight ratio of 1 to
(0.02 to 0.5) to (0.2 to 2), in particular 1 to (0.05 to 0.2) to
(0.5 to 2).
37. Composition according to claim 31 characterized in that it
comprises a dispersing agent and/or an organic binder or sizing
agent and/or titanium dioxide.
38. Composition according to claim 31 characterized in that it is a
brush-on color for coating a fibrous material.
39. UV absorbers for use for stabilizing the whiteness of
lignin-containing fibrous materials, characterized by a structural
element of the formula 2wherein: R.sup.1: denotes H,
(C.sub.1-C.sub.12)-alkanoyl, in particular acetyl, propionyl,
n-butanoyl; (C.sub.1-C.sub.12) alkoxycarbonyl, in particular
--COOCH.sub.3, --COOC.sub.2H.sub.5, R.sup.2: denotes
(C.sub.1-C.sub.12)-alkyl, linear or branched, in particular methyl,
ethyl, n-propyl, n-butyl, i-propyl Ar--OH: denotes
hydroxy-substituted aryl radical, wherein at least one hydroxyl
group is bonded in the ortho- or para-position of the aromatic
bonded to the olefinic double bond, in addition further
substituents, such as alkyl, in particular methyl, ethyl, propyl,
n-butyl, i-propyl, sec-butyl, tert-butyl, alkoxy, in particular
methoxy and ethoxy, phenyl, p(o)-hydroxyphenyl, benzoyl, --COOH and
SO.sub.3H can be bonded to the aromatic, and wherein Ar represents
the benzene or naphthalene ring.
40. UV absorbers for use for stabilizing the whiteness of
lignin-containing fibrous substances according to claim 39
characterized in that it is a
3-methoxy-4-hydroxybenzylidene-malonic acid dialkyl ester, wherein
alkyl represents methyl or ethyl.
Description
INTRODUCTION AND BACKGROUND
[0001] The present invention relates to a process for stabilizing
the whiteness of lignin-containing fibrous materials, in particular
paper and cardboard of mechanically produced fibrous materials, in
particular wood pulp, against light-induced yellowing. The process
comprises the use of a sulfur-containing whiteness stabilizer. The
invention furthermore relates to whiteness-stabilized
lignin-containing fibrous materials obtainable according to the
invention and to a stabilizer composition.
[0002] The low stability to whiteness of lignin-containing
high-yield fibrous materials such as are obtainable using
mechanically produced fibrous substances, that is to say in
particular fibrous substances produced thermomechanically (TMP),
chemo-thermomechanically (CTMP) or by stone-grinding of wood (SGW),
is a serious obstacle to employing high-yield fibrous substances
obtained in this way, in particular wood pulps, for the production
of high-finish paper and card products. Bleached lignin-containing
wood pulps and celluloses in particular are highly susceptible to
light-induced yellowing.
[0003] The causes and prevention of light-induced yellowing of
celluloses are reported by J. S. Gratzl in "Das Papier" 39/10 A
(1985), pages V16 to V23. For increasing the whiteness and
improving the light stability of celluloses, in particular
lignin-rich high-yield celluloses, reductive measure are suitable,
such as treatment of the cellulose with sodium boranate or the use
of a combination of formaldehyde with a dithionite salt or addition
of tin(II) salts. The tendency towards yellowing can furthermore be
reduced effectively by using a UV filter, for example a
2-hydroxybenzophenone or 2-hydroxybenzotriazole.
[0004] In the context of mechanistic studies by Dian Yan Lee et al.
(Holzforschung 45 (1991) suppl. pages 15 to 20), it was found that
1-thioglycerol is active to a certain extent in both the bleaching
and the stabilization of the whiteness of mechanically produced
fibrous substances. A disadvantage of thioglycerol is its low
molecular weight and therefore also its unpleasant smell, which
impedes use in practice.
[0005] C. Heitner ("Pulp Bleaching-Principle and Practice", C. W.
Dence, D. W. Reeve, eds., TAPPI PRESS, Atlanta, 1996, pages 183 to
211) gives an overview of the prior art on yellowing of
lignin-containing fibrous substances. The use of phosphites, UV
absorbers and agents which trap free radicals, such as ascorbic
acid, thiols and thioethers, is reported. It is stated in WO
99/05108 that the substances mentioned in this document are still
not an adequate and practically applicable solution for avoiding
light-induced yellowing.
[0006] According to another study of light- and heat-induced
yellowing of fibrous substances (M. Beyer, Ch. Burich and K.
Fischer in "Das Papier", volume 10A (1995), pages V8 to V14)
yellowing can be counteracted by targeted application of a
combination of ascorbic acid with a compound containing a thiol
group. A further improvement is achieved by applying a pigmented
coat to a paper comprising the combination mentioned. This document
does not reveal what structure the thiol must have to effect
effective resistance to yellowing.
[0007] According to U.S. Pat. No. 5,942,567, yellowing of casting
resins can be reduced by using a combination of a phenolic
antioxidant and a non-aromatic thiol compound. The thiols are
alkylmercaptans, such as, in particular, hexylmercaptan,
dithioglycol and 3-mercaptopropyltriethoxysil- ane, all of which
are an odour nuisance. No reference to the use of such a
combination as a whiteness stabilizer for lignin-containing fibrous
materials, such as paper, is to be found in this document.
[0008] The teaching of U.S. Pat. No. 6,059,927 is a process for
stabilizing the whiteness of mechanically produced bleached wood
pulps. For this, a combination of an aqueous formaldehyde solution
with a carbonate is employed in the wood pulp substance; a further
increase in the resistance to yellowing is effected by using a
polyethylene glycol bisthiol, polyethylene glycol bisthiolactate
and polyethylene glycol bisthioglycollate being mentioned
exclusively as the thiol compound. The amount of these thiols
employed is in the range from 2 to 6 wt. %, based on the wood pulp.
The high amount of the said bisthiols employed is a disadvantage of
this process. No indication that these bisthiols can be employed in
the absence of formaldehyde and carbonate for stabilizing whiteness
can be found in this document.
[0009] Studies by B. J. W. Cole at al. (Journal of Wood Chemistry
and Technology, 20 (1), 1-17 (2000)) on the bleaching and
photostabilization of high-yield fibrous substances show that
ethylene glycol bismercaptoacetate (=ethylene glycol
dithioglycollate) has a bleaching and stabilizing action, while
pentaerythrytol tetrathioglycollate has no bleaching action and
leads to only a slight decolorization in the system
investigated.
[0010] Effective stabilization of the whiteness of TMP and CTMP
fibrous substances or papers produced therefrom is effected
according to WO 99/05108 by the use of derivatives of
1-oxyl-2,2,6,6-tetramethylpiperidin- -4-ol and selected
hydroxylamine salts. The action is increased by additional use of
co-additives, such as UV absorbers, antioxidants, nitrones,
fluorescent brighteners and sulfur-containing stabilizers. The
sulfur-containing stabilizers, which are employed only in
combination with an N-oxide or hydroxylamine light stabilizer, are
compounds with a thiol or thioether group. The following thiols,
which are predominantly compounds presenting an odour nuisance, are
mentioned: thioglycerol, dithiothreitol, 2,2'-oxydiethanethiol,
2-(2'-methoxyethoxy)-ethanethiol, thioglycollic acid, 2- and
3-mercaptopropionic acid and Na salts thereof, diesters of the
mercaptocarboxylic acid mentioned with ethylene glycol and
polyethylene glycol and trimethylolpropane
tri(3-mercaptopropionate).
[0011] It is therefore an object of the present invention is to
improve stabilizing the whiteness of lignin-containing fibrous
materials against light-induced yellowing and to enable producing
paper and card with improved resistance to yellowing.
[0012] According to another object the whiteness stabilizers to be
used according to the invention should have the lowest possible
smell and show a high activity by themselves, and in particular in
combination with other known whiteness stabilizers or co-additives
at the lowest possible total concentration of additives.
[0013] A further object of the invention is aimed at providing a
composition comprising one or more whiteness stabilizers, the use
of which in the pulp of the fibrous substance or in a composition
for impregnating or coating, such as a size or a so-called coat,
the leads to a high stabilization of the whiteness of fibrous
material.
SUMMARY OF THE INVENTION
[0014] The above and other objects of the present invention can be
achieved by or process which uses a whiteness stabilizer selected
from the group consisting of
[0015] (i) thiols which have at least one aliphatically or
cycloaliphatically bonded thiol group and additionally at least one
further hydrophilic group selected from the group consisting of
--OH, --NH.sub.2,--NHR.sup.1, --NR.sup.1R.sup.2, wherein R.sup.1
and R.sup.2 represent C.sub.1- to C.sub.4-alkyl or C.sub.2- to
C.sub.4-hydroxyalkyl, such as hydroxyethyl and dihydroxypropyl,
C.sub.2- to C.sub.4-alkanoyl- or -hydroxyalkanoyl, or taken
together represent cycloalkyl, or --COOH, --SO.sub.3H and
--PO.sub.3H.sub.2 and salts of the acid and base function,
[0016] (ii) thiols which contain at least one aliphatically or
cycloaliphatically bonded thiol group and additionally at least one
CC double bond,
[0017] (iii) thiols which contain at least one thiol group bonded
to a heteroaromatic, and
[0018] (iv) di- and polysulfides with at least one heteroaromatic
bonded to the di-/polysulfide group,
[0019] in the production of the fibrous material, that is to say in
particular paper and card, with the proviso that thioglycerol,
dithiothreitol mercaptoacetic acid, 2- and 3-mercaptopropionic
acid, and salts therefor being excluded as the whiteness
stabilizer.
[0020] The term "lignin-containing fibrous materials" is understood
as meaning all materials which comprise a lignin-containing fibrous
substance as the essential constituent. The fibrous substances are,
in particular, lignin-containing wood pulps, but lignin-containing
celluloses are also suitable for use in the process according to
the invention. Stabilization of the whiteness and therefore
prevention of yellowing is of industrial importance in particular
in so-called high-yield wood pulps which are obtained
thermomechanically (TMP) or chemo-thermomechanically (CTMP) or by
stone-grinding (SGW). The raw materials mentioned are inexpensive
raw materials which, if the whiteness stabilization is adequate,
can be employed both in papers of medium quality and in
high-quality papers and cards. The process according to the
invention is also particularly suitable for stabilizing the
whiteness of bleached wood pulps, which tend to yellow in
particular without stabilization.
[0021] According to the invention, the resistance to yellowing of
lignin-containing fibrous substances and the materials produced
therefrom can be increased and the whiteness thus stabilized if a
thiol compound according to the invention is employed in an active
amount during the production of the fibrous material. The amount
employed depends on the desired degree of stabilization and on
whether and to what extent further whiteness stabilizers and/or
co-additives are employed in the production of the fibrous
material. The amount of thio compound according to the invention
employed is conventionally in the range from 0.01 to 5 wt. %,
preferably 0.1 to 3 wt. % and particularly preferably 0.5 to 2 wt.
%, in each case based on the dry fibrous substance.
DETAILED DESCRIPTION OF INVENTION
[0022] The whiteness stabilizers according to the invention from
group (i) are thiols which have at least one aliphatically or
cycloaliphatically bonded thiol group and additionally at least one
hydrophilic group according to the claims. Such thiols can have
various structures, such as, for example:
[0023] Mercaptoalcohols of the general formula
(HS).sub.mX(OH).sub.n, wherein X represents an optionally
alkyl-substituted cycloaliphatic, a linear or branched hydrocarbon
radical having 4 to 20 C atoms, in particular 5 to 8 C atoms, and m
and n represent an integer from 1 to 5. Examples are di-, tri- and
tetrathiopentitols and -hexitols.
[0024] Mercaptoalcohols of the general formula
(HS).sub.mY(OH).sub.n, wherein Y represents a linear or branched
hydrocarbon radical which is interrupted once or several times by a
--O--, --S--, --NH-- or N-alkyl bridge and has 4 to 20 C atoms in
total and m and n have the abovementioned meaning. Examples are
reaction products of polyhydric alcohols with ethylene sulfide or a
mercaptoalkyl halide, at least one hydroxyl group remaining on the
hydrocarbon radical.
[0025] Mercaptoalcohols of the general formula
(HS(CH.sub.2).sub.p--COO).s- ub.mZ(OH).sub.n, wherein Z has the
meaning of X or Y or represents a polymeric hydrocarbon chain, m
and n have the above mentioned meaning or in the case of a
polymeric matrix can also go far beyond the values mentioned and p
represents 1 or 2, wherein the mercapto group can be bonded
internally or terminally. These are preferably an ester of a
polyhydric alcohol, such as ethylene glycol, di-, tri- and
polyethylene glycol, propane-1,2 and -1,3-diol, butane-1,4-diol,
hexane-1,2,6-triol, trimethylolethane (TME), trimethylolpropane
(TMP), erythritol, pentaerythritol (penta), di-TME, di-TMP,
di-penta, sugar alcohols, sugar acids and lactones thereof with a
mercaptocarboxylic acid from the series consisting of
mercaptoacetic acid (=thioglycollic acid), 2- and
3-mercaptopropionic acid, mono- and dimercaptosuccinic acid. The
polyhydric alcohol can also be partly esterified with a
mercaptocarboxylic acid other than those mentioned above. The
polymeric alcohols esterified with a mercaptocarboxylic acid are,
for example, an oligo- or polysaccharide, such as starch, or
polyvenyl alcohol.
[0026] Particularly suitable mercaptoalcohols of the abovementioned
type are the di- or triester of pentaerythritol with mercaptoacetic
acid or 1 or 2-mercaptopropionic acid, in particular
pentaerythritol trithiolglycollate, and the di-, tri- or tetraester
of a pentitol or hexitol, in particular sorbitol
tetrathioglycollate. It has been found that such compounds have a
considerably better action as a whiteness stabilizer than the
compounds which are already known and have a similar structure but
no longer contain a free hydroxyl group.
[0027] Mercaptoamines which contain, as hydrophilic group(s), at
least one NH.sub.2, NHR.sup.1 or NR.sup.1R.sup.2 group, wherein
R.sup.1 and R.sup.2 can be identical or different and can represent
a lower alkyl group, such as methyl, ethyl, propyl, hydroxyethyl,
hydroxypropyl or dihydroxypropyl or can be bonded together, on a
linear, cycloaliphatic or branched carbon skeleton, which can be
interrupted once or several times by --O--, --S--, --NH-- or
N-alkyl, also have a stabilizing action. Examples are
N-mercaptoethyl-diethylenetriamine and
N-mercaptoethyl-diethanolamine, and salts of these amines.
[0028] Thiols with an acid function as the hydrophilic group are,
for example, mercaptosuccinic acid, dimercaptosuccinic acid,
mercaptopropanesulfonic acid, mercaptoethyaminomethanephosphonic
acid. Salts, in particular alkali metal salts, of the acids
mentioned are also active.
[0029] A particularly preferred group of thiols of group (i) are
mercaptoamino acids, such as, in particular, cysteine, N-acylated
mercaptoamino acids, such as acetylcysteine, and di- and
oligopeptides with at least one amino acid containing mercapto
groups. A particularly good whiteness stabilizer, which moreover is
completely odour-free and is highly active especially with
co-stabilizers, is the tripeptide glutathione
(.gamma.-glutamylcysteineglycine).
[0030] It has been found that the yellowing-inhibiting action of
mercapto compounds is increased by additionally containing at least
one olefinic CC double bond (group (ii)). These are preferably
compounds which have an allyl structure. Examples are esters of
allyl alcohol or cinnamyl alcohol with a mercaptocarboxylic acid
having 2 to 4 C atoms, such as thioglycollic acid, thiolactic acid
and mercaptosuccinic acid.
[0031] Surprisingly, thiols which contain at least one mercapto
group on a heteroaromatic have proven to be an active yellowing
inhibitor (group(iii)). The heteroaromatics are 5- and 6-membered
heteroaromatics with optionally another fused-on aromatic or
heteroaromatic ring system. They contain one, two or three
heteroatoms from the series consisting of O, S and N, rings with
two or three heteroatoms being preferred, such as those selected
from the group consisting of s-triazine, thiadiazole, thiazole,
diazole. Such heteroaromatics optionally contain, in addition to at
least one mercapto group, one or two amino or alkylated amino
groups, alkylmercapto or alkoxy groups. They are particularly
preferably monomercapto-diamino-s-triazines and
dimercapto-amino-s-triazine, it being possible for amino groups to
be substituted by one or two C.sub.1- to C.sub.3-alkyl groups or
allyl groups or to be part of a five- or six-membered ring.
Examples are: 2-mercapto-4-allylamino-6-diethylamino-s- -triazine,
2,4-dimercapto-6-allylamino-s-triazine and
2-mercapto-4-ethylamino-6-morpholino-s-triazine. Finally,
trimercapto-s-triazine, in particular in the form of a mono-, di-
and tri-alkali metal salt, also has a whiteness-stabilizing action.
The mercaptotriazine compounds can be obtained in a manner known
per se by stepwise reaction of cyanuric chloride with one or two
amines and sodium hydrogen sulfide.
[0032] Whiteness stabilizers of group (iv) contain one or more di-
or polysulfide groupings on a heteroaromatic of the type already
mentioned above or between two heteroaromatics. Polysulfide groups
are also understood as meaning tri- and tetrasulfides. The second
function of a polysulfide can be satisfied by hydrogen or an alkali
metal, or by oligomerization.
[0033] Examples are 2,4-di-polysulfido-6-diethylamino-s-triazine,
bis-2-methylamino-1,3,4-thiadiazin-5-yl disulfide and
bis-[2,4-di(dialkylamino)-triazin-6-yl] tetrasulfide. The
polysulfidotriazine is prepared e.g. by reaction of
2-diethylamino-4,6-dimercapto-2-triazine with S.sub.2Cl.sub.2 in
petroleum ether; thiadiazinyl disulfide is obtainable by an
oxidation of methylamino-mercapto-1,3,4-thiadiazole with
H.sub.2O.sub.2, and the tetrasulfide mentioned can be obtained by
reaction of the corresponding bis(dialkylamino)-triazinylmercapto
compound with S.sub.2Cl.sub.2.
[0034] The action of whiteness stabilizers to be used according to
the invention which have one or more thiol groups or
di-/polysulfide groups can be increased by the co-use of known
whiteness stabilizers or co-stabilizers. These are substances
selected from the group consisting of light stabilizers, in
particular those selected from the group consisting of sterically
hindered nitroxides and hydroxylamines and salts thereof (=HALS
stabilizers), UV absorbers, antioxidants, fluorescent brighteners,
agents which trap free radicals, metal deactivators, phosphites,
aromatic sulfides and reducing agents other than thiols.
[0035] The HALS light stabilizers are compounds such as are
mentioned by way of example in WO 99/05108 and U.S. Pat. Nos.
5,496,875 and 6,080,864. Suitable compounds are e.g.
1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidin- e;
1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium chloride or a
carboxylic acid salt according to this type, such as
tetra(1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium)
ethylenediaminetetraacetate;
1-oxyl-2,2,6,6-tetramethyl-4-alkyloxypiperid- ine;
octadecyl-2,2,6,6-tetramethyl-4-piperidinyl carbonate. The amount
of such stabilizers employed is expediently in the range from 0.01
to 2 wt. %. Combinations of thiols according to the invention, in
particular those from group (i), such as mercaptocarboxylic acid
esters of polyhydric alcohols, amino acids or oligopeptides
containing thiol groups, with HALS light stabilizers lead to a
synergistic effect in respect of the whiteness stabilization, so
that the total amount of stabilizers can be reduced, or the
activity can be increased noticeably by means of a small addition
of a HALS stabilizer, such as 0.02 to 0.2 wt. %.
[0036] The UV absorbers are known substances selected from the
group consisting of benzotriazoles and benzophenones, such as
3-tert-butyl-4-hydroxy-5-(2H-benzotriazol-2-yl)-hydrocinnamic acid
and 2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole;
2,4-dihydroxybenzophenone and
2,2-dihydroxy-4,4-dimethoxy-5,5-disulfobenz- ophenone di-Na salt. A
further class of UV absorbers which are suitable for stabilizing
the whiteness of lignin-containing fibrous substances in the
absence of whiteness stabilizers according to the invention
comprises substances represented by the structural of the general
formula: 1
[0037] wherein:
[0038] R.sup.1: denotes H, (C.sub.1-C.sub.12)-alkanoyl, in
particular acetyl, propionyl, n-butanoyl;
(C.sub.1-C.sub.12)alkoxycarbonyl, in particular --COOCH.sub.3,
--COOC.sub.2H.sub.5,
[0039] R.sup.2: denotes (C.sub.1-C.sub.12)-alkyl, linear or
branched, in particular methyl, ethyl, n-propyl, n-butyl,
i-propyl
[0040] Ar--OH: denotes hydroxy-substituted aryl radical, wherein at
least one hydroxyl group is bonded in the ortho- or para-position
of the aromatic bonded to the olefinic double bond, in addition
further substituents, such as alkyl, in particular methyl, ethyl,
propyl, n-butyl, i-propyl, sec-butyl, tert-butyl, alkoxy, in
particular methoxy and ethoxy, phenyl, p(o)-hydroxyphenyl, benzoyl,
--COOH and SO.sub.3H, can be bonded to the aromatic, and wherein Ar
represents the benzene or naphthalene ring.
[0041] 3-Methoxy-4-hydroxybenzylidene-malonic acid esters and
3-(3-methoxy-4-hydroxybenzylidene-pentane-2,4-dione are
particularly suitable.
[0042] The antioxidants are usually sterically hindered phenols,
such as 2,6-di.-tert-butyl-4-methylphenol, hydroxylated
thiodiphenyl ethers, triazines, such as
2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxya-
nilino-1,3,5-triazine.
[0043] Phosphites and phosphonites, in particular sterically
hindered compounds, such as tris(2,4-di-tert-butylphenyl)
phosphite, assist the whiteness stabilization, since they act as
agents which trap peroxides and free radicals.
[0044] Various hydrazine derivatives, such as isophthaloyl
dihydrazide and N,N-bis(salicyloyl)hydrazine, are active as metal
deactivators. A further class comprises complexing agents from the
series consisting of citrates, gluconates, keto acids,
aminocarboxylic acids, such as EDTA, DTPA and phosphonates, such as
hydroxyethane-diphosphonate (HEDP).
[0045] The fluorescent brighteners are, in particular, known
substances selected from the group consisting of stilbene
derivatives, such as 4,4'-(diphenyl)-stilbene and
4,4'-bis-(triazinylamino)-stilbene-2,2'-disu- lfonic acid.
[0046] Polymeric inhibitors, such as polyethylene glycol,
polyvinylpyrrolidone and polytetrahydrofuran, are also suitable
co-stabilizers.
[0047] One or more thiols or di-/polysulfides according to the
invention in combination with a HALS light stabilizer or other
agents which trap free radicals and a UV absorber selected from the
group consisting of benzotriazoles or benzophenones and optionally
additionally or alternatively an antioxidant, in particular a
sterically hindered phenol, are particularly preferably employed,
since a synergistic effect is fully effective here. Examples of
particularly active combinations are: glutathione or sorbitol
tetrathioglycollate, 2,2,6,6-tetramethyl-4-hydrox- ypiperidine
N-oxide or a derivative thereof and 2-(2-hydroxyphenyl)-benzot-
riazole.
[0048] One or more whiteness stabilizers to be used according to
the invention selected from the group consisting of thiols or
di-/polysulfides or a combination of these compound(s) with one or
more co-stabilizers selected from the group consisting of the
abovementioned substance classes can be employed at various points
in the production process of the fibrous material. It is possible
to add the whiteness stabilizer or stabilizers and co-stabilizers
individually or in the form of a composition to the mass of the
fibrous substance, which is present e.g. in the form of a pulp. The
addition is possible e.g. before, during or after a bleaching stage
which is optionally carried out, or during the dewatering of the
fibrous material.
[0049] In an alternative and usually preferred embodiment, the
whiteness stabilizer or a composition comprising it is sprayed in
the form of a solution or suspension on to the fibrous material,
which has been at least partly dewatered. This spraying process is
then followed by the sizing and/or coating stages well known in
paper and card production.
[0050] According to another preferred alternative, the whiteness
stabilizer to be used according to the invention or a composition
comprising it is introduced into the medium used for sizing or
coating the paper or card and then applied to the fibrous
material.
[0051] It has been found that a considerable intensification of the
yellowing-inhibiting effect of the whiteness stabilizers to be used
according to the invention and composition comprising such can be
achieved by applying a pigment-containing coat, in particular
containing titanium dioxide, after application of the whiteness
stabilizer, for example by impregnation or together with the size
application. According to a particularly preferred embodiment, the
whiteness stabilizer or stabilizers and optionally co-stabilizers
are applied to the fibrous material together with titanium dioxide
and optionally other constituents of a size or coating and the
material is processed to the finished paper or card in a manner
known per se.
[0052] The invention also provides a whiteness-stabilized
lignin-containing fibrous material, in particular paper and card of
mechanically produced wood pulp or high-yield cellulose, which can
be bleached or unbleached, which comprises a whiteness stabilizer
selected from the group consisting of the thiols, di or
polysulfides of groups (i) to (iv) to be used according to the
invention. The whiteness stabilizer here can be either in the pulp
or in a size or coating or in a surface layer of the fibrous
material produced by impregnation.
[0053] According to a particularly preferred embodiment of the
whiteness-stabilized lignin-containing fibrous material according
to the invention, this comprises a coating-which can be the size or
a coating with a brush-on color which comprises titanium dioxide. A
TiO.sub.2 content in the range from 0.1 to 5 wt. %, based on the
dried coating, leads to a significant increase in the resistance to
yellowing.
[0054] As has been explained in detail in the description of the
process according to the invention, in addition to one or more
whiteness stabilizers according to the invention, the pulp of the
fibrous material or a size or coating on this can also comprise
other known whiteness stabilizers and/or co-stabilizers.
[0055] The invention also provides a composition which comprises at
least one of the whiteness stabilizers to be used according to the
invention from group (i) to (iv) in an aqueous, organic or
aqueous-organic liquid or paste-like medium which can be used for
spraying or coating. The composition preferably comprises one or
more of the preferred stabilizers described above. According to a
particularly preferred embodiment, the composition additionally
comprises one or more other whiteness stabilizers/co-stabilizers
selected from the group consisting of agents which trap free
radicals, such as HALS light stabilizers, antioxidants, UV
absorbers, reducing agents, fluorescent brighteners, metal
deactivators, phosphites and aromatic sulfides. According to a
particularly preferred embodiment, the composition comprises the
combination of a whiteness stabilizer according to the invention, a
HALS light stabilizer and/or a UV absorber and/or an antioxidant.
Examples of such compositions have already been mentioned above.
The composition expediently comprises at least one whiteness
stabilizer according to the invention, a HALS light stabilizer and
a UV absorber in a weight ratio of 1 to (0.02 to 0.5) to (0.2 to
2), in particular 1 to (0.05 to 0.2) to (0.5 to 2). A preferred
composition is a brush-on color for coating a fibrous material. For
the purpose of white coarse sand stabilization, such a brush-on
color particularly preferably comprises, in addition to
conventional base constituents, a combination of at least one white
coarse sand stabilizers according to the invention at least one UV
absorber and at least one agent which traps free radicals.
[0056] Particularly preferred compositions additionally comprise
titanium dioxide, in addition to at least one whiteness stabilizer
according to the invention. Compositions which are used for sizing
purposes or a final coat additionally comprise conventional sizing
components or binders and further inorganic pigments, additives and
dispersing auxiliaries.
[0057] The present invention thus provides a large number of
further highly active whiteness stabilizers of prevention of
yellowing of lignin-containing fibrous materials, such as, in
particular, paper and card. The whiteness stabilizers can be used
by themselves, but preferably in combination with known whiteness
stabilizers and/or co-stabilizers, synergistic effects being
achieved thereby. A further increase in the resistance to yellowing
is effected by the additional use of titanium dioxide in the size
or in a coat. The subject matter according to the invention allows
mechanically produced fibrous substances to be employed for the
production of high-quality papers and cards, since the risk of
light-induced yellowing is reduced decisively by the use of
whiteness stabilizers according to the description herein.
[0058] The invention is illustrated with the aid of the following
examples.
EXAMPLES
[0059] In each case a TCF-bleached aspen CTMP cellulose with a
whiteness of 86% was used as the paper base
[0060] 1. Individual substances
[0061] The substances shown in table 1 were applied to the paper in
the form of a solution. The amount applied was 1% by weight,
calculated with respect to the cellulose. After drying, irradiation
was carried out. Irradiation time was 10 h in a xenon test
apparatus, level 2. The whiteness (W) (%) as a function of time was
determined; the loss in whiteness results from this as the
difference (=dW) between the whiteness before (=W.sub.0) and after
(W.sub.10h)the irradiation or as the relative drop in whiteness
dW.100/W.sub.0.
1TABLE 1 W.sub.0 (%) before W.sub.10 (%) W.sub.0- Number Stabilizer
irradiation after 10 h W.sub.10 CE 1 None 86 55 31 Ex. 1
2-diallylamino-4-(3'- 88 67 21 Methoxypropyl) amino-
6-mercapto-1,3,5- triazine Ex. 2 2-N-piperidino-4- 87 65 22
Ethylamino-6- mercapto-1,3,5- trazine Ex. 3 2,2'-bis-(5- 81 61 20
methylamino-1,3,4- thiadiazolyl) disulfide CE 2
2,2,6,6-tetramethyl- 78 56 22 4-hydroxypiperidine N-oxide (is
coloured!) Ex. 4 sorbitol 83 58 25 tetrathioglycollate Ex. 5
pentaerythritol 83 58 25 triatiolglycollate CE 3 pentaerythritol 86
54 32 tetra-thioglycollate
[0062] Examples 1 to 5 show the good action of thiols according to
the invention. The action is the same or better than that of the
HALS stabilizer of comparison example CE 2. Comparison of example 5
with comparison example CE 3 shows the unexpected influence of the
additional hydroxyl group.
[0063] 2. Combinations
[0064] Combinations of a whiteness stabilizer (WS) according to the
invention according to table 2a and b (1 wt. %), the HALS light
stabilizer (agent which traps free radicals=FRT)
2,2,6,6-tetramethyl-4-hy- droxypiperidine N-oxide (0.1 wt. %) and
the UV absorber (UV) 2-(2-hydroxyphenyl)-benzotriazole (1 wt. %)
were investigated. The use and testing were carried out analogously
to those described under 1. The relative decrease in whiteness (%)
after irradiation for 10 h and 20 h is shown in table 2b.
2TABLE 2a W.sub.0 (%) before W.sub.10 (%) W.sub.0- Number
Combination irradiation after 10 h W.sub.10 CE 1 no WS, FRT and UV
86 55 31 CE 4 no WS; 87 68 19 with FRT and UV Ex. 6 sorbitol
tetrakis- 87 75 12 thioglycollate and FRT and UV
[0065]
3 TABLE 2b 1 ( W t - W 0 ) 100 W 0 after 10 h after 20 h Number
Combination (%) (%) CE 1 no WS, FRT and UV 33 42 CE 4 no WS, with
FRT and 22 31 UV Ex. 6 sorbitol tetrakis- 14 22 thioglycollate with
FRT and UV Ex. 7 cinnamyl meroapto- 19 26.5 glycollate with UV and
FRT
[0066] 3. Combinations and TiO.sub.2 in a Coat
[0067] Combinations comprising whiteness stabilizers (WS) according
to the invention the UV (UV) absorber mentioned under 2. and an
agent which traps free radicals (FRT) were investigated. The amount
employed, where present, as before 1% WS, 0.1% FRT, 1% UV, in each
cased based on the fibrous substance). After application of the
particular stabilizer composition and drying, a
TiO.sub.2-containing coat was applied.
[0068] Composition of the brush-on color: 5 parts of inorganic
pigment, of which 4 parts of calcium carbonate, 0.9 part of kaolin,
0.1 part of titanium dioxide, 3.5 parts of binder, 3.5 parts of
water, dispersing auxiliary. Coat thickness 12 g/m.sup.2.
[0069] The results follow from table 3a: Stabilizer-free comparison
example CE 5 stabilizer-free paper was coated only with the stated
brush-on color. Stabilizer-free paper. The paper according to
example 8 contained, under the coat, an impregnation with
glutathione (1 wt. %, based on the dyestuff), and that of example 9
additionally FRT 0.1 wt. % and UV (1 wt. %). The comparison shows
the increase in action on changing from the coat-free,
non-stabilized system (CE 1) to the system with a
TiO.sub.2-containing coat (CE 5), to the system with glutathione
under a TiO.sub.2-containing coat (Ex. 8) and finally a
TiO.sub.2-containing coat on a paper with an impregnation
comprising glutathione, FRT and UV.
4 TABLE 3 a W.sub.10 (%) W.sub.0- after W.sub.10 Number Stabilizer;
coat W.sub.0 (%) 10 h (%) CE 1 no stabilizer, no 86 55 31 TiO.sub.2
CE 5 no stabilizer, but 88 68 20 coat with TiO.sub.2 Ex. 8
Glutathione + coat 85 72 13 with TiO.sub.2 Ex. 9 Glutathione and 85
80 5 FRT and UV and coat with TiO.sub.2
[0070] Examples Ex. 10 and Ex. 11 in table 3 illustrate the
influence of TiO.sub.2 in the coat. The coat composition in E 10
contained no TiO.sub.2 by 1 part of kaolin, in example 11 0.7 part
of kaolin and 0.3 part of TiO.sub.2; the other constituents
corresponded to the coat composition described above.
5TABLE 3 b W.sub.10 (%) W.sub.0- after W.sub.10 Number Stabilizer;
coat W.sub.0 (%) 10 h (%) Ex. 10* Pentaerythritol 83.5 77.5 6 tris-
thioglycollate and FRT and UV and coat without TiO.sub.2 Ex. 11*
pentaerythritol 86.5 82.5 4 tris- thioglycollate and FRT and UV and
coat with TiO.sub.2 *The abovementioned coat composition contained
in example 10 . . . parts of TiO.sub.2 and 1 part of kaolin; in
example 11 the composition contained 0.7 parts of kaolin and 0 3
parts of TiO.sub.2.
[0071] Example 10 and 11 illustrate the influence of TiO.sub.2 in
the coat.
[0072] Further variations and modifications of the foregoing will
be apparent to those skilled in the art and are intended to be
encompassed by the claims appended hereto.
[0073] German priority application 101 12 101.6 is relied on and
incorporated herein by reference.
* * * * *