U.S. patent application number 12/305108 was filed with the patent office on 2009-11-05 for method for finishing paper and paper products.
This patent application is currently assigned to BASF SE. Invention is credited to Simon Champ, Roland Ettl.
Application Number | 20090272505 12/305108 |
Document ID | / |
Family ID | 38846005 |
Filed Date | 2009-11-05 |
United States Patent
Application |
20090272505 |
Kind Code |
A1 |
Champ; Simon ; et
al. |
November 5, 2009 |
METHOD FOR FINISHING PAPER AND PAPER PRODUCTS
Abstract
Process for finishing paper and paper products by treating the
surface of paper or paper products with at least one finishing
agent, at least one finishing agent being applied in the form of a
pattern on the top and/or bottom of paper or paper products, and
the papers and paper products obtainable by the process.
Inventors: |
Champ; Simon; (Ludwigshafen,
DE) ; Ettl; Roland; (Ketsch, DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
BASF SE
Ludwigshafen
DE
|
Family ID: |
38846005 |
Appl. No.: |
12/305108 |
Filed: |
June 20, 2007 |
PCT Filed: |
June 20, 2007 |
PCT NO: |
PCT/EP2007/056104 |
371 Date: |
December 16, 2008 |
Current U.S.
Class: |
162/134 ;
162/158; 162/164.1; 162/164.3; 162/164.4; 162/164.6; 162/168.1;
162/168.7 |
Current CPC
Class: |
D21H 19/66 20130101 |
Class at
Publication: |
162/134 ;
162/158; 162/168.7; 162/168.1; 162/164.4; 162/164.1; 162/164.3;
162/164.6 |
International
Class: |
D21H 19/66 20060101
D21H019/66; D21H 23/22 20060101 D21H023/22; D21H 17/37 20060101
D21H017/37; D21H 17/34 20060101 D21H017/34; D21H 17/59 20060101
D21H017/59; D21H 17/45 20060101 D21H017/45; D21H 17/52 20060101
D21H017/52; D21H 17/57 20060101 D21H017/57 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 27, 2006 |
EP |
06116165.9 |
Claims
1. A process for finishing paper or a paper product comprising
treating the surface of said paper or paper product with at least
one finishing agent, wherein the at least one finishing agent is
applied in the form of a pattern to the top and/or bottom of said
paper or paper product.
2. The process according to claim 1, wherein the finishing agent is
applied with the aid of a printing process to the top and/or bottom
of said paper or paper product.
3. The process according to claim 1, wherein the finishing agent is
printed on the top and/or the bottom of said paper or paper product
by a screen printing, inkjet printing, flexographic printing or
offset printing process.
4. The process according to claim 1, wherein the finishing agent is
printed on the top of said paper or paper product by the inkjet
printing process.
5. The process according to claim 1, wherein an engine-sized paper
or paper product is used.
6. The process according to claim 1, wherein the finishing agents
are applied in the form of a grid or of a rhombus or in spiral,
circular, two-dimensional, strip or dot form on the top and/or
bottom of paper or paper products, the pattern printed on being
present in each case in ordered or in random form.
7. The process according to claim 1, wherein the finishing agent is
a strength agent, a water repellant, a hydrophilizing agent, a
paper coating slip and/or a biocide.
8. The process according to claim 1, wherein the finishing agent is
at least one agent which increases the stiffness of paper.
9. The process according to claim 1, wherein the finishing agent is
a dry strength agent and/or a wet strength agent for paper.
10. The process according to claim 1, wherein the finishing agent
is at least one water repellant selected from the group consisting
of alkyldiketenes, alkylsuccinic anhydrides, rosin size, polymer
sizes based on styrene/(meth)acrylate polymers, isocyanates,
ethylene copolymer waxes, polymers comprising siloxane groups and
polymers comprising bound fluorine.
11. The process according to claim 1, wherein the finishing agent
is at least one heat-curable binder selected from the group
consisting of the urea-formaldehyde adducts, urea-glyoxal adducts,
melamine-formaldehyde adducts, phenol-formaldehyde adducts, one-
and two-component systems based on epoxy resins, polyurethanes or
isocyanates, polyacrylates, polymethacrylates,
styrene/(meth)acrylate copolymer dispersions and
styrene/butadiene/(meth)acrylic acid copolymer dispersions.
12. The process according to claim 1, wherein the finishing agent
is at least one heat-curable binder comprising (a) a polymer which
is obtained by free radical polymerization and which comprises from
5 to 100% by weight of an ethylenically unsaturated carboxylic
anhydride or of an ethylenically unsaturated dicarboxylic acid
whose carboxyl groups can form anhydride groups, incorporated in
the form of polymerized units, and (b) at least one alkanolamine
which comprises at least two hydroxyl groups in the molecule and/or
at least one polyhydric alcohol.
13. The process according to claim 1, wherein the finishing agent
is at least one heat-curable binder comprising an aqueous mixture
with at least one polycarboxylic acid and at least one polyhydric
alcohol and/or at least one polyfunctional amine and/or an
alkanolamine.
14. The process according to claim 1, wherein the finishing agent
is at least one biocide selected from the group consisting of
polymers comprising vinylamine units, polymers comprising
ethylenimine units, combinations of at least one polymer comprising
vinylamine units and at least one organic quaternary ammonium salt
and combinations of at least one polymer comprising ethylenimine
units and at least one organic quaternary ammonium salt.
15. A paper or paper product obtained by the process of claim 1.
Description
[0001] The invention relates to a process for finishing paper and
paper products by treating the surface of paper and paper products
with at least one finishing agent, and the finished paper and paper
products obtainable by the process.
[0002] In order to improve the properties of paper and paper
products, for example, the surface of paper or paper products is
treated with finishing agents, such as strength agents, water
repellants, hydrophilizing agents and/or paper coating slips. The
finishing agents are always applied over the whole area on the top
and/or the bottom of the paper or of the paper products.
[0003] The prior German Application 10 2005 050 658.5 discloses a
process for reducing the absorption of water and water vapor and
for increasing the dimensional stability of paper and paper
products. There, cellulose fibers or a paper product obtained
therefrom by draining on a wire are or is first compressed, the
compressed paper product is then brought into contact with an
aqueous solution and/or dispersion of the reactive material, the
compression is then eliminated with further action of the aqueous
solution and/or dispersion and the paper product is dried and is
heated to a temperature at which the reactive material reacts with
itself and/or with the cellulose fibers with crosslinking. Suitable
reactive materials are, for example, heat-curable binders, such as
urea-formaldehyde adducts, one- or two-component systems based on
epoxy resins, polyacrylates and polymethacrylates. In this process,
too, the entire top or bottom of the product is treated with at
least one reactive material.
[0004] It is the object of the invention to improve the properties
of paper and paper products, in particular the stiffness,
printability, laminatability and biocidal action with respect to
microorganisms, in such a way that an adequate effect is achieved
in comparison with known processes even with a smaller amount of
finishing agents.
[0005] The object is achieved, according to the invention, by a
process for finishing paper and paper products by treating the
surface of paper or paper products with at least one finishing
agent, if at least one finishing agent is applied in the form of a
pattern on the top and/or bottom of paper or paper products. The
finishing agent is preferably applied with the aid of a printing
process on the top and/or bottom of paper or paper products. Such
printing processes are part of the prior art. They are usually used
for printing on sized or coated papers or on textiles with print
pastes which differ from finishing agents for paper. The finishing
agent can be printed, for example, by the screen printing, inkjet
printing, flexographic printing or offset printing process on the
top and/or the bottom of paper or paper products.
[0006] Preferably, the finishing agent is printed by the inkjet
printing process on the top of paper or paper products. The paper
may be, for example, unsized or may be an engine-sized paper or
paper product. Suitable engine sizes are, for example,
alkyldiketenes, alkenylsuccinic anhydrides or rosin size.
[0007] The invention also relates to papers and paper products
which in each case are obtainable by the process according to the
invention. These are substantially writing and printing papers,
packaging papers, corrugated board, wallpapers, cardboard, filters
and laminated materials, for example comprising a composite of
board or paper and at least one film of a thermoplastic, for
example polyethylene, polypropylene, polyamide, polyester or
polycarbonate.
[0008] The finishing agents are printed, for example, in the form
of a grid or of a rhombus or in spiral, circular, two-dimensional,
strip or dot form on the top and/or bottom of the paper or paper
products, it being possible for a pattern to be arranged in ordered
or in random form (stochastically). The finishing agents are always
applied according to the pattern. In contrast to known methods for
applying finishing agents to paper, in which the finishing agent is
applied over the whole top or bottom of paper, the finishing agent
in the process according to the invention is applied to the surface
of the paper in a manner such that the whole area is not coated
therewith. For example, the proportion with the area printed
altogether with finishing agent is from 0.1 to 90, preferably from
1 to 70, % and is in general in the range from 10 to 50%. The other
part of the surface of the paper which is not treated with a
finishing agent remains untreated. After the printing, the printed
paper or paper product is dried and, if appropriate, heated to a
temperature at which the finishing agents crosslink, for example to
temperatures in the range from 35 to 200.degree. C.
[0009] The effect achieved in each case with the aid of the process
according to the invention, for example the stiffness of a paper,
is dependent on a plurality of factors, especially on the
composition and amount of the finishing agent, on the structure of
the finishing agent printed in each case on the paper and on the
orientation of the paper, i.e. the stiffness of the paper depends
on the orientation of the cellulose fibers. In the case of a paper
sheet, it differs in the machine direction compared with the
direction transverse thereto. The finishing agent is applied in the
form of a pattern and can be printed, for example, in the form of a
grid, of a rhombus or of a polygon (e.g. hexagon, octagon) or in
spiral, circular, two-dimensional, strip or dot form on the top
and/or bottom of the paper or paper products. The individual strips
of a grid or of a rhombus may have different dimensions, for
example a thickness of from 0.1 to 100 mm, preferably from 1 to 10
mm, and a length of from 0.1 to 100 mm, preferably from 1 to 10 mm.
The distance between the individual strips of a grid, i.e. the
unprinted areas may have, for example, a spacing of from 0.1 to 100
nm, preferably from 1 to 10 mm. The grid may be square, rectangular
or rhombic. If the paper is printed with strips, the strips can
extend over the total length or width of the paper.
[0010] The paper may also be printed in a dot-like manner with a
multiplicity of dots or in a two-dimensional manner,
two-dimensional being understood as meaning that a larger area is
provided with a finishing agent, for example an area having the
dimensions 2.times.2 to 10 cm or 4.times.1 to 10 cm. Circular areas
which are printed on a paper may have, for example, a diameter of
from 1 mm to 10 cm.
[0011] The process according to the invention can be integrated
into the papermaking process. Thus, it is possible, for example, to
print a finishing agent onto the still moist paper and then to dry
the paper thus treated and, if appropriate, to heat it to a higher
temperature (from 170 to 200.degree. C.) in order to crosslink the
finishing agent printed on. However, it is also possible to print a
finishing agent onto the paper during the drying process or
thereafter, to dry the printed material and, if appropriate, to
crosslink it. At least one finishing agent can be printed on the
paper products in a corresponding manner during or after the
production.
[0012] Suitable papers which are finished according to the
invention are preferably all paper types, in particular base
papers. Paper products are to be understood as meaning, for
example, packaging papers, corrugated board, wallpapers, cardboard
and laminated materials, for example comprising a composite of
board or paper and at least one film of a thermoplastic. For
example, for the production of the papers and of the paper
products, it is possible to start from cellulose fibers of all
types, both from natural and from recovered fibers, in particular
from fibers from wastepaper, which are generally used as a mixture
with virgin fibers. Virgin fibers are to be understood as meaning
cellulose fibers which have not yet been processed to a paper
product or which have not yet been dried. Suitable fibers for the
production of the pulps are all qualities customary for this
purpose, for example mechanical pulp, bleached and unbleached
chemical pulp and paper stocks from all annual plants. Mechanical
pulp includes, for example, groundwood, thermomechanical pulp
(TMP), chemothermomechanical (CTMP), pressure groundwood,
semi-chemical pulp, high-yield pulp and refiner mechanical pulp
(RMP). For example, sulfate, sulfite and soda pulps are suitable as
chemical pulp. Unbleached pulp, which is also referred to as
unbleached kraft pulp, is preferably used. Suitable annual plants
for the production of paper stocks are, for example, rice, wheat,
sugar cane and kenaf.
[0013] According to the invention, the paper or the paper products
is or are printed with a finishing agent according to a pattern.
The finishing agent used is, for example, a strength agent, a water
repellant, a hydrophilizing agent, a paper coating slip or an
indicator system for biomaterials (for example for bacteria or
viruses). At least one agent which increases the stiffness of paper
is particularly preferably used for finishing. These agents
generally also simultaneously increase the dry and/or wet strength
of paper and paper products. Further finishing agents are customary
dry strength agents and/or wet strength agents for paper.
[0014] According to the invention, in order to increase the
stiffness of paper and paper products, a heat-curable binder from
the group consisting of the urea-formaldehyde adducts, urea-glyoxal
adducts, melamine-formaldehyde adducts, phenol-formaldehyde
adducts, one- and two-component systems based on epoxy resins,
polyurethanes or isocyanates, polyacrylates, polymethacrylates,
styrene/(meth)acrylate copolymer dispersions and/or
styrene/butadiene/(meth)acrylic acid copolymer dispersions is
preferably used. In some cases, the use of mixtures of at least two
reactor materials is of interest, for example mixtures of
melamine/urea-formaldehyde condensates. The reactive materials may
be present as aqueous solution or as aqueous dispersion. Here,
transitions between solution and dispersion are possible. If
dispersions are used, for example, the mean particle diameter of
the polymer particles dispersed in water is below 1 .mu.m,
preferably below 500 nm and in general in the range from 10 to 100
nm.
[0015] The aqueous solution and/or dispersion thus comprises, for
example, a group of a reactive, crosslinkable material which may
consist of [0016] (i) at least one reactive substance which forms a
polymer, [0017] (ii) if appropriate, at least one
C.sub.1-5-alcohol, at least one polyol or mixtures thereof and
[0018] (iii) at least one catalyst.
[0019] Examples of (i) a reactive substances which forms a polymer
are urea-glyoxal adducts and derivatives thereof, e.g.
1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-one (referred to
as "DMDHEU" below). When printing on paper or paper products, it
can be used either alone or together with (ii) at least one
C.sub.1-5-alcohol, one polyol or mixtures thereof. If
1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-one is used
together with an alcohol and/or a polyol as a finishing agent,
modified 1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-ones
(referred to as "mDMDHEU" below) accordingly forms. Such compounds
are disclosed, for example, in U.S. Pat. No. 4,396,391 and WO
98/29393. These are reaction products of
1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-one with at
least one C.sub.1-5-alcohol, at least one polyol or mixtures
thereof.
[0020] The compounds of the group (ii) include C.sub.1-5-alcohols,
for example methanol, ethanol, n-propanol, isopropanol, n-butanol,
isobutanol, tert-butanol and n-pentanol, methanol being preferred,
and polyols, such as ethylene glycol, diethylene glycol, 1,2- and
1,3-propylene glycol, 1,2-, 1,3-, and 1,4-butylene glycol,
glycerol, trimethylolpropane and polyalkylene glycols, such as
polyethylene glycol, polypropylene glycol and block copolymers of
ethylene glycol and propylene glycol. Polyethylene glycols of the
formula HO(CH.sub.2CH.sub.2O).sub.nH where n is from 3 to 20 and
diethylene glycol are preferred.
[0021] In order to prepare modified
1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-one (DMDHEU),
DMDHEU and the monohydric alcohol and/or the polyol are mixed, the
monohydric alcohol and/or the polyol being used in an amount of
from 0.1 to 2.0 mol equivalents each, based on DMDHEU. The mixture
of DMDHEU, monohydric alcohol and/or polyol is reacted, for
example, at temperatures of from 20 to 70.degree. C. and a pH of
from 1 to 2.5, the pH being adjusted to 4 to 8 after reaction.
[0022] (i) a reactive substance which forms a polymer is to be
understood as meaning both urea-formaldehyde adducts and
urea-glyoxal adducts and derivatives of each of them. The following
compounds may be mentioned by way of example: dimethylolurea,
bis(methoxymethyl)urea, tetramethylolacetylenediurea,
methylolmethylurea and
1,3-dimethyl-4,5-dihydroxyimidazolidin-2-one,
1,3-bis(hydroxymethyl)imidazolidin-2-one or mixtures thereof. These
compounds of the group (i) can, if appropriate, also be used as
finishing agents in the presence of (ii) at least one
C.sub.1-5-alcohol, at least one polyol or mixtures thereof.
Suitable alcohols and polyols have already been mentioned above.
Methanol, diethylene glycol or mixtures thereof are preferred.
[0023] The aqueous solution of the finishing agent comprises the
reactive compounds of the group (i) and the compounds of the group
(ii), for example, in a concentration of from 1 to 70% by weight,
preferably from 10 to 60% by weight and in particular from 20 to
60% by weight. The impregnating agent preferably comprises
1,3-bis(hydroxymethyl)-4,5-dihydroxyimidazolidin-2-one (DMDHEU) as
a compound of the group (i).
[0024] In addition to (i) and, if appropriate, (ii), the finishing
agent always comprises a catalyst (iii). Suitable catalysts (iii)
are, for example, metal salts from the group consisting of metal
halides, metal sulfates, metal nitrates, metal tetrafluoroborates,
metal phosphates or mixtures thereof. Individual examples of (iii)
are magnesium chloride, magnesium sulfate, zinc chloride, lithium
chloride, lithium bromide, boron trifluoride, aluminum chloride,
aluminum sulfate, zinc nitrate and sodium tetrafluoroborate. Said
compounds can be used either alone or in a mixture as the
catalyst.
[0025] Further suitable compounds (iii) are ammonium salts, such as
ammonium chloride, ammonium sulfate, ammonium oxalate, diammonium
phosphate or mixtures thereof. In addition, organic and/or
inorganic acids can be used as the catalyst. Examples of these are
maleic acid, formic acid, acetic acid, priopionic acid, citric
acid, tartaric acid, oxalic acid, p-toluenesulfonic acid,
hydrochloric acid, sulfuric acid, boric acid or mixtures
thereof.
[0026] Magnesium chloride, zinc chloride, magnesium sulfate,
aluminum sulfate or mixtures of these compounds are preferably used
as compounds of the group (iii). Magnesium chloride is particularly
preferred.
[0027] The catalyst (iii) is present, for example in a
concentration of from 0.1 to 10% by weight, preferably from 0.2 to
8% by weight, particularly preferably from 0.3 to 5% by weight,
based on the components (i)-(iii) of the reactive material.
[0028] Among the above-described products which comprise
formaldehyde incorporated in the form of condensed units, in
particular low-formaldehyde condensates are used. In the present
context, low-formaldehyde is to be understood as meaning that the
reactive materials comprise no substantial amounts of free
formaldehyde and that no substantial amounts of formaldehyde are
released even on drying or curing of the cellulose fibers or paper
products treated therewith. In general, such reactive materials
comprise <100 ppm of formaldehyde.
[0029] Further reactive materials which react with themselves
and/or cellulose fibers with crosslinking are formaldehyde-free,
heat-curable binders. Such binders are described, for example, in
the following publications, which are hereby incorporated by
reference in the disclosure of the present invention, namely U.S.
Pat. No. 4,076,917, EP-A 0 445 578, EP-A 0 583 086, EP-A 0 651 088,
WO 97/31036, page 4, line 12 to page 12, line 14, WO 97/31059, page
2, line 22 to page 12, line 5, WO 97/31060, page 3, line 8 to page
12, line 36, DE-A 199 49 591, page 3, line 5 to page 7, line 38, WO
01/27163, page 5, line 34 to page 22, line 2 and the
radiation-curable binders disclosed in DE-A 199 17 965.
[0030] Suitable heat-curable binders apart from the binders which
are described in the abovementioned publications are all curable
binders which are described in the literature, for example, for
strengthening fiber webs and/or which are used for this purpose in
practice, such as heat-curable resins based on phenol and
formaldehyde, the abovementioned melamine-formaldehyde and
urea-formaldehyde resins, urea-glyoxal resins and in particular
formaldehyde-free one- and two-component systems based on epoxy
resins or polyurethanes, polyacrylates, polymethacrylates,
polyvinyl acetates, styrene/acrylate copolymer dispersions,
styrene/methacrylate copolymer dispersions,
styrene/butadiene/(meth)acrylic acid copolymer dispersions and
mixtures of said dispersions with a mixture of a polycarboxylic
acid and a polyhydric alcohol as a crosslinking component.
[0031] Examples of preferred finishing agents are heat-curable
binders in the form of mixtures of [0032] (a) a polymer which is
obtainable by free radical polymerization and which comprises from
5 to 100% by weight of an ethylenically unsaturated carboxylic
anhydride or of an ethylenically unsaturated dicarboxylic acid
whose carboxyl groups can form anhydride groups, incorporated in
the form of polymerized units, and [0033] (b) at least one
alkanolamine which comprises at least two hydroxyl groups in the
molecule and/or at least one polyhydric alcohol.
[0034] Specific examples of such mixtures are aqueous solutions
and/or dispersions of a copolymer of 80% by weight of acrylic acid
and 20% by weight of maleic acid, having a molar mass M.sub.w of
from 15 000 to 900 000, which solutions and/or dispersions comprise
from about 40 to 60% by weight of solids, in combination with
triethanolamine or aqueous solutions of a copolymer of 55% by
weight of acrylic acid and 45% by weight of the maleic acid in
combination with triethanolamine. These binders can, if
appropriate, comprise an esterification catalyst and/or a compound
comprising bound phosphorus, such as hypophosphorous acid, as a
reaction accelerator.
[0035] The copolymer (a) described above may also be composed, for
example, of [0036] from 50 to 99.5% by weight of at least one
ethylenically unsaturated mono- or dicarboxylic acid, [0037] from
0.5 to 50% by weight of at least one ethylenically unsaturated
compound from the group consisting of the esters of ethylenically
unsaturated monocarboxylic acids and the monoesters and the
diesters of ethylenically unsaturated dicarboxylic acids with an
amine having at least one hydroxyl group and [0038] up to 20% by
weight of another monomer.
[0039] Heat-curable, aqueous compositions which comprise at least
one copolymer (a) and at least one alkanolamine or
higher-functional .beta.-hydroxyalkylamine and/or at least one
polyhydric alcohol can, if appropriate, additionally comprise at
least one surfactant.
[0040] Further heat-curable binders which can be used as finishing
agents are based on aqueous mixtures of [0041] polycarboxylic
acids, such as polyacrylic acid, polymethacrylic acid, copolymers
of acrylic acid and maleic acid, copolymers of methacrylic acid and
maleic acid, copolymers of ethylene and maleic acid, styrene and
maleic acid, or copolymers of acrylic acid or methacrylic acid and
esters of acrylic or methacrylic acid with, preferably, monohydric
alcohols comprising 1 to 24 carbon atoms, the polycarboxylic acids
having a K value of from 50 to 100 (measured in unneutralized form
of the polycarboxylic acids according to H. Fikentscher in
dimethylformamide at 25.degree. C. and a polymer concentration of
0.1% by weight) and [0042] polyhydric alcohols, such as
trimethylpropane, glycerol, 2-hydroxymethylbutane-1,4-diol or
polyvinyl alcohol, and/or polyfunctional amines and/or
alkanolamines.
[0043] Polycarboxylic acids, polyhydric alcohols, alkanolamines and
polyfunctional amines are preferably used in amounts such that the
number of acid functions is equivalent to the total number of
alcoholic hydroxyl and amine functions, cf. EP-A 0 445 578. In
addition, crosslinkable materials which consist of an aqueous
solution of a polycarboxylic acid (homo- or copolymer), preferably
having a molar mass M.sub.w of 10 000 or less, and a polyol, such
as triethanolamine, and in which the ratio of the equivalents of
hydroxyl groups to equivalents of carboxyl groups is in the range
from 0.4:1 to 1.0:1 are suitable, cf. EP-A 0 990 727.
[0044] In the process according to the invention, reactive
materials which are sold under the trade name Acrodur.RTM. by BASF
Aktiengesellschaft are particularly advantageously used as
finishing agents. An example of this is an aqueous styrene/acrylate
polymer dispersion which is modified with a polycarboxylic acid and
a polyhydric alcohol as crosslinking component. It crosslinks at a
temperature of only 130.degree. C. However, in order to achieve
high production rates, the crosslinking is preferably carried out
at temperatures of from 180 to 200.degree. C. A further
formaldehyde-free binder is commercially available, for example, as
a colorless to slightly yellowish, clear, aqueous solution of a
modified polycarboxylic acid with a polyhydric alcohol as
crosslinking component. It crosslinks, for example, at drying
temperatures of from about 160 to 180.degree. C.
[0045] Formaldehyde-free reactive materials which comprise at least
one polycarboxylic acid and at least one polyhydric alcohol and/or
alkanolamine or polyfunctional amine are particularly preferred.
Compositions which comprise these reactive agents can, if
appropriate, also comprise further formaldehyde-free polymers, e.g.
polyacrylates, which are sold under the trade name Acronal.RTM. by
BASF Aktiengesellschaft. The aqueous solutions and/or dispersions
of a reactive material which are used for printing comprise the
reactive material, for example, in an amount of from 1 to 70% by
weight, preferably from 10 to 60% by weight and in general from 30
to 50% by weight.
[0046] Further finishing agents are water repellants from the group
consisting of alkyldiketenes, alkenylsuccinic anhydrides, rosin
size, polymer sizes based on styrene/(meth)acrylate polymers and
isocyanates. Preferred alkyldiketenes are C.sub.14- to
C.sub.22-alkyl- or alkenyldiketenes. They are prepared, for
example, from the corresponding acyl chlorides by elimination of
hydrogen chloride with tertiary amines. The diketenes which can be
used according to the invention may carry saturated or unsaturated,
branched or cyclic hydrocarbon radicals. Examples of such
alkyldiketenes are tetradecyldiketene, hexadecyldiketene,
octadecyldiketene, docosyldiketene, palmityldiketene,
oleyldiketene, stearyldiketene and behenyldiketene.
Stearyldiketene, palmityldiketene, oleyldiketene, behenyldiketene,
isostearyidiketene or mixtures of alkyl diketenes, e.g. mixtures of
behenyldiketene and stearyldiketene or mixtures of stearyldiketene
and palmityldiketene, are preferably used.
[0047] Alkenylsuccinic anhydrides are described in detail, for
example, in U.S. Pat. No. 3,102,064, EP-A 0 609 879 and EP-A-0 593
075. All alkenylsuccinic anhydrides which have been described to
date in the literature as engine sizes for paper are also suitable
according to the invention as finishing agents, either alone, or in
combination with alkyldiketenes. Suitable alkylsuccinic anhydrides
comprise, in the alkyl group, an alkyl radical having at least 6
carbon atoms, preferably a C.sub.14- to C.sub.24-olefin radical.
Particularly preferred alkenylsuccinic anhydrides comprise 16 to
22, in general 16 to 18, carbon atoms in the alkenyl group. They
may comprise linear, additionally unsaturated or branched alkenyl
groups. Alkenylsuccinic anhydrides are obtainable, for example,
from .alpha.-olefins, which are first isomerized. This gives a
mixture of different isomers, which is then reacted with maleic
anhydride in an ene reaction to give succinic anhydrides.
Alkenylsuccinic anhydrides are prepared according to EP-A 0 593 075
by reaction of propylene oligomers or n-butylene oligomers with
maleic anhydride. Examples of this group of reactive sizes are
decenylsuccinic anhydride, dodecenylsuccinic anhydride,
octenylsuccinic anhydride and n-hexadecenylsuccinic anhydride. The
individual isomeric succinic anhydride may have a different sizing
effect. Thus, for example, 2- and 3-hexadecenyl succinic anhydrides
are not as effective engine sizes as the isomeric 4-, 5-, 6-, 7-
and 8-hexadecenylsuccinic anhydrides.
[0048] A further finishing agent in the context of the present
invention is rosin size and derivatives derived therefrom, such as,
for example, reaction products of rosin size and maleic anhydride.
The derivatives may be branched or unsaturated, e.g. abietic acid.
Moreover, polymer sizes based on styrene and (meth)acrylates, which
are preferably obtainable by polymerization of the monomers in the
presence of degraded starch, are suitable as finishing agents. Such
sizes are disclosed, for example, in EP-A 0 276 770, EP-A 0 257
412, EP-A 0 307 812 and WO 02/14393. If sizes for paper are used
according to the invention as finishing agents, sized papers which
are particularly suitable as writing and printing papers are
obtained.
[0049] Further finishing agents are hydrophilizing agents and water
repellants, such as ethylene copolymer waxes, polymers comprising
siloxane groups and/or polymers comprising bound fluorine, such as
Lodyne.RTM. from Clariant, and paper coating slips (aqueous
mixtures of at least one pigment and at least one binder, based in
each case on an acid group-comprising copolymer of styrene and
butadiene or of styrene and (meth)acrylate) and biocides. The
papers and paper products finished with a biocide are used, for
example, for applications in the sanitary or hygiene area, in the
food sector, in particular for the packaging of foods, or for
industrial applications, e.g. for filters.
[0050] Particularly suitable biocides are compounds from the group
consisting of polymers comprising vinylamine units, polymers
comprising ethylenimine units, combinations of at least one polymer
comprising vinylamine units and at least one organic quaternary
ammonium salt and combinations of at least one monomer comprising
ethylenimine units and at least one organic quaternary ammonium
salt. The suitable polymers and the organic quaternary ammonium
salts are known. Furthermore, DE-A 196 08 555 discloses use of
polymers comprising vinylamine units or ethylenimine units as
biocidal active substances, for example as slime control agents in
papermaking. The polymers which are described in DE-A 196 08 555
and comprise vinylamine units or ethylenimine units are applied,
preferably printed on, by the process according to the invention as
a biocide on paper or paper products in the form of a pattern.
Regarding the details of the polymers suitable according to the
invention, reference is therefore made to the abovementioned DE-A
196 08 555, page 1, line 43 to page 10, line 8.
[0051] Polymers comprising vinylamine units are obtainable by a
two-stage process by polymerization of N-vinylcarboxamides and
hydrolysis of the resulting poly(N-vinylcarboxamides) with
formation of vinylamine units, cf. U.S. Pat. No. 4,421,602, U.S.
Pat. No. 5,334,287, EP-A 0 216 387, U.S. Pat. No. 5,981,689, WO
00/63295, U.S. Pat. No. 6,121,409 and U.S. Pat. No. 6,132,558.
Examples of N-vinylcarboxamides are N-vinylformamide,
N-vinyl-N-methylformamide, N-vinylacetamide,
N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide and
N-vinylpropionamide. Said monomers can be polymerized either alone,
as a mixture with one another or together with other monomers.
N-vinylformamide is preferred.
[0052] Suitable monoethylenically unsaturated monomers which are
copolymerized with the N-vinylcarboxamide are all compounds
copolymerizable therewith. Examples of these are vinyl esters of
saturated carboxylic acids of 1 to 6 carbon atoms, such as vinyl
formate, vinyl acetate, N-vinylpyrrolidone, vinyl propionate and
vinyl butyrate, and vinyl ethers, such as C.sub.1- to C.sub.6-alkyl
vinyl ethers, e.g. methyl or ethyl vinyl ether. Further suitable
comonomers are esters of alcohols having, for example, 1 to 6
carbon atoms, amides and nitriles of ethylenically unsaturated
C.sub.3- to C.sub.6-carboxylic acids, for example methyl acrylate,
methyl methacrylate, ethyl acrylate, ethyl methacrylate and
dimethyl maleate, acrylamide and methacrylamide and acrylonitrile
and methacrylonitrile.
[0053] Further suitable compounds copolymerizable with
N-vinylcarboxamides are carboxylic esters of glycols or
polyalkylene glycols, in each case only one OH group being
esterified, e.g. hydroxyethyl acrylate, hydroxyethyl methacrylate,
hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypropyl
methacrylate, hydroxybutyl methacrylate and monoesters of acrylic
acid with polyalkylene glycols having a molar mass of from 500 to
10 000. Further suitable comonomers are esters of ethylenically
unsaturated carboxylic acids with aminoalcohols, such as, for
example, dimethylaminoethyl acrylate, dimethylaminoethyl
methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl
methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl
methacrylate, diethylaminopropyl acrylate, dimethylaminobutyl
acrylate and diethylaminobutyl acrylate. The basic acrylates can be
used in the form of the free bases, of the salts with mineral
acids, such as hydrochloric acid, sulfuric acid or nitric acid, of
the salts with organic acids, such as formic acid, acetic acid or
propionic acid, or of the sulfonic acids or in quaternized form.
Suitable quaternizing agents are, for example, dimethyl sulfate,
diethyl sulfate, methyl chloride, ethyl chloride or benzyl
chloride. Further suitable comonomers are amides of ethylenically
unsaturated carboxylic acids, such as acrylamide, methacrylamide
and N-alkylmono- and diamides of monoethylenically unsaturated
carboxylic acids having alkyl radicals of 1 to 6 carbon atoms, e.g.
N-methylacrylamide, N,N-dimethylacrylamide, N-methylmethacrylamide,
N-ethylacrylamide, N-propylacrylamide and tert-butylacrylamide, and
basic (meth)acrylamides, such as, for example,
dimethylaminoethylacrylamide, dimethylaminoethylmethacrylamide,
diethylaminoethylacrylamide, diethylaminoethylmethacrylamide,
dimethylaminopropylacrylamide, diethylaminopropylacrylamide,
dimethylaminopropylmethacrylamide and
diethylaminopropylmethacrylamide.
[0054] Furthermore, N-vinylpyrrolidone, N-vinylcaprolactam,
acrylonitrile, methacrylonitrile, N-vinylimidazole and substituted
N-vinylimidazoles, such as, for example, N-vinyl-2-methylimidazole,
N-vinyl-4-methylimidazole, N-vinyl-5-methylimidazole and
N-vinyl-2-ethylimidazole, and N-vinylimidazolines, such as
N-vinylimidazoline, N-vinyl-2-methylimidazoline and
N-vinyl-2-ethylimidazoline, are suitable as comonomers.
N-vinylimidazoles and N-vinylimidazolines are used not only in the
form of free bases but also in the form neutralized with mineral
acids or organic acids or in quaternized form, the quaternization
preferably being carried out with the dimethyl sulfate, diethyl
sulfate, methyl chloride or benzyl chloride. Diallydialkylammonium
halides, such as, for example, diallyldimethylammonium chloride,
are also suitable.
[0055] The copolymers comprise, for example, [0056] from 95 to 5
mol %, preferably from 90 to 10 mol %, of at least one
N-vinylcarboxamide, preferably N-vinylformamide, and [0057] from 5
to 95 mol %, preferably from 10 to 90 mol %, of monoethylenically
unsaturated monomers incorporated in the form of polymerized units.
The comonomers are preferably free of acid groups.
[0058] The polymerization of the monomers is usually carried out in
the presence of free radical polymerization initiators. The homo-
and copolymers can be obtained by known processes; for example they
are obtained by solution polymerization in water, alcohols, ethers
or dimethylformamide or in mixtures of different solvents, by
precipitation polymerization, inverse suspension polymerization
(polymerization of an emulsion of a monomer-containing aqueous
phase in an oil phase) and polymerization in a water-in-water
emulsion, for example in which an aqueous monomer solution is
dissolved or emulsified in an aqueous phase and polymerization for
formation of an aqueous dispersion of a water-soluble polymer, as
described, for example, in WO 00/27893. After the polymerization,
the homo- and copolymers which comprise N-vinylcarboxamide units
incorporated in the form of polymerized units are partly or
completely hydrolyzed as described below.
[0059] In order to prepare polymers comprising vinylamine units, it
is preferable to start from homopolymers of N-vinylformamide or
from copolymers which are obtainable by copolymerization of [0060]
N-vinylformamide with [0061] vinyl formate, vinyl acetate, vinyl
propionate, acrylonitrile, methyl acrylate, ethyl acrylate and/or
methyl methacrylate and subsequent hydrolysis of the homo- or
copolymers with formation of vinylamine units from the
N-vinylformamide units incorporated in the form of polymerized
units, the degree of hydrolysis being, for example, from 1 to 100
mol %, preferably from 25 to 100 mol %, particularly preferably
from 50 to 100 mol % and especially preferably from 70 to 100 mol
%. The degree of hydrolysis corresponds to the content of
vinylamine groups in the polymers, in mol %. The hydrolysis of
polymers described above is effected by known methods, by the
action of acids (e.g. mineral acids, such as sulfuric acid,
hydrochloric acid or phosphoric acid, carboxylic acids, such as
formic acid or acetic acid, or sulfonic acids or phosphonic acids),
bases or enzymes, as described, for example, in DE-A 31 28 478 and
U.S. Pat. No. 6,132,558. When acids are used as hydrolysis agents,
the vinylamine units of the polymers are present as the ammonium
salts, whereas the free amino groups are formed in the case of
hydrolysis with bases.
[0062] In most cases, the degree of hydrolysis of homo- and
copolymers used is from 85 to 95 mol %. The degree of hydrolysis of
the homopolymers is equivalent to the content of vinylamine units
in the polymers. In the case of copolymers which comprise vinyl
esters incorporated in the form of polymerized units, hydrolysis of
the ester groups with formation of vinyl alcohol units can occur in
addition to the hydrolysis of the N-vinylformamide units. This is
the case in particular when the hydrolysis of the copolymers is
carried out in the presence of sodium hydroxide solution.
Acrylonitrile incorporated in the form of polymerized units is
likewise chemically modified in the hydrolysis. Here, for example,
amido groups or carboxyl groups form. The homo- and copolymers
comprising vinylamine units can, if appropriate, comprise up to 20
mol % of amidine units, which form, for example, by reaction of
formic acid with two neighboring amino groups or by intramolecular
reaction of an amino group with a neighboring amido group, e.g. of
N-vinylformamide incorporated in the form of polymerized units.
[0063] The average molar mass M.sub.w of the polymers comprising
vinylamine units are, for example, from 500 to 10 million,
preferably from 750 to 5 million and particularly preferably from 1
000 to 2 million g/mol (determined by light scattering). This molar
mass range corresponds, for example, to K values of from 30 to 250,
preferably from 60 to 100 (determined according to H. Fikentscher
in 5% strength aqueous sodium chloride solution at 25.degree. C., a
pH of 7 and a polymer concentration of 0.5% by weight). Polymers
which comprise vinylamine units and have K values of from 85 to 95
are particularly preferably used as a biocide.
[0064] The polymers comprising vinylamine units have, for example,
a charge density (determined at pH 7) of from 0 to 18 meq/g,
preferably from 5 to 18 meq/g and in particular from 10 to 16
meq/g.
[0065] The polymers comprising vinylamine units are preferably used
in salt-free form. Salt-free aqueous solutions of polymers
comprising vinylamine units can be prepared, for example, from the
salt-containing polymer solutions described above with the aid of
ultrafiltration or with suitable membranes at cut-offs of, for
example, from 1000 to 500 000 dalton, preferably from 10 000 to 300
000 dalton.
[0066] Derivatives of polymers comprising vinylamine units may also
be used. Thus, it is possible, for example, to prepare a
multiplicity of suitable derivatives from the polymers comprising
vinylamine units for amidation, alkylation, sulfonamide formation,
urea formation, thiourea formation, carbamate formation, acylation,
carboxymethylation, phosphonomethylation or Michael addition of the
amino groups of the polymer. Of particular interest here are
uncrosslinked polyvinylguanidines, which are obtainable by reaction
of polymers comprising vinylamine units, preferably
polyvinylamines, with cyanamide (R.sup.1R.sup.2N--CN, where
R.sup.1, R.sup.2 are H, C.sub.1- to C.sub.4-alkyl, C.sub.3- to
C.sub.6-cycloalkyl, phenyl, benzyl, alkyl-substituted phenyl or
naphthyl), cf. U.S. Pat. No. 6,087,448, column 3, line 64 to column
5, line 14.
[0067] The polymers comprising vinylamine units also comprise
hydrolyzed graft polymers of, for example, N-vinylformamide on
polyalkylene glycols, polyvinyl acetate, polyvinyl alcohol,
polyvinylformamides, polysaccharides, such as starch,
oligosaccharides or monosaccharides. The graft polymers are
obtainable by, for example, subjecting N-vinylformamide to free
radical polymerization in an aqueous medium in the presence of at
least one of said grafting bases, if appropriate together with
copolymerizable other monomers, and subsequently hydrolyzing the
grafted-on vinylformamide units in a known manner to give
vinylamine units.
[0068] Preferred polymers comprising vinylamine units are
hydrolyzed homopolymers of N-vinylformamide having a degree of
hydrolysis of from 1 to 100 mol %, preferably from 25 to 100 mol %,
and copolymers of N-vinylformamide and vinyl formate, vinyl
acetate, vinyl propionate, acrylonitrile, methyl acrylate, ethyl
acrylate and/or methyl methacrylate, having a degree of hydrolysis
of from 1 to 100 mol %, preferably from 25 to 100 mol %, and K
values of 30 to 150, in particular from 60 to 100. The
abovementioned partly or completely hydrolyzed homopolymers of
N-vinylformamide are particularly preferably used in the process
according to the invention.
[0069] Typical members of these homopolymers of N-vinylformamide
are known under the trade names Catiofast.RTM. VFH, Catiofast.RTM.
VSH and Catiofast.RTM. VMP from BASF Aktiengesellschaft.
[0070] The polyvinylamine preferably comprises from 0.1 to 22
milliequivalents (meq), particularly preferably from 5 to 18 meq,
of cationic groups per gram of polyvinylamine. The polymers
comprising vinylamine units are used, for example, in the form of
an aqueous dispersion or solution.
[0071] The polymers comprising ethylenimine unites are preferably
polyethylenimines which are obtainable by polymerization of
ethylenimine in the presence of, as a catalyst, acids, Lewis acids
or compounds eliminating acids. Such catalysts are, for example,
alkyl halides, such as methyl chloride, ethyl chloride, propyl
chloride, methylene chloride, trichloromethane, carbon
tetrachloride or tetrabromomethane. The polyethylenimines have, for
example, molar masses M.sub.w in the range from 120 to 10 million,
preferably from 500 to 500 000 and in particular from 1000 to 50
000. Polymers which are obtainable by grafting polyamidoamines with
ethylenimine or by grafting polymers of open-chain
N-vinylcarboxamides with ethylenimine are also suitable as
compounds comprising ethylenimine units. Grafted polyamidoamindes
are disclosed, for example, in U.S. Pat. No. 4,144,123. The
polymers comprising ethylenimine units have, for example, a charge
density (measured at pH 7) of from 0.1 to 22 meq
(milliequivalents), preferably from 4 to 10 meq. They are
preferably used in aqueous solution.
[0072] The above-described polymers comprising vinylamine or
ethylenimine units are used either alone or in combination with an
organic, quaternary ammonium salt as a biocide. Such ammonium salts
preferably comprise at least one hydrophobic molecular group,
preferably one to four, particularly preferably one to three, very
particularly preferably two or three and in particular three
hydrophobic molecular groups, bonded to the N atoms, such as, in
particular, C.sub.1- to C.sub.30-alkyl groups.
[0073] Particularly effective biocides of ammonium salts preferably
have at least one reactive group which results in or promotes
binding of the ammonium salt to the substrate surface. The reactive
group may be an organic molecular group which comprises at least
one functional group which can react with the substrate surface,
such as, in particular, epoxy groups, hydroxyl groups, acid groups
and alkoxy groups. The ammonium salts preferably comprises, as the
reactive group, an alkoxylated silane which is bound by a spacer to
the N atom. Such ammonium salts are disclosed, for example, in WO
2004/087226, in particular in claim 6.
[0074] The quaternary ammonium salt is preferably a low molecular
weight compound and has in particular a molecular weight of less
than 2000 g/mol, particularly preferably less than 1500 g/mol, in
particular from 200 to 1000 g/mol. It is used in particular in the
form of an aqueous dispersion or preferably of an aqueous solution.
Like the polymers comprising amino groups, the organic, quaternary
polymer, too, can be applied alone as a biocide according to a
pattern to the surface of paper or paper products. Preferably,
however, it is used in combination with at least one polymer
comprising vinylamine units and/or at least one polymer comprising
ethylenimine units. It is easiest to start from commercially
available aqueous solutions or dispersions of the polymers
comprising amino groups, to mix them with an aqueous solution of
the quaternary amine and then to print the mixture thus obtainable
on a paper. However, it is also possible first to print according
to a pattern on a paper or a paper product separately with a
polymer comprising vinylamine units and/or a polymer comprising
ethylenimine units and then--if appropriate after a drying step--to
print on at least one organic, quaternary amine, likewise in the
form of a pattern, and then to dry the printing material. As a
result, a mixture of the two biocides is then present on the
substrate surface in this case too.
[0075] Independently of the form of use, the proportion of the
vinylamine and/or polyethylenimine is from 1 to 99% by weight,
preferably from 10 to 90% by weight and particularly preferably
from 30 to 70% by weight, based on the sum of the weights of
polymer and ammonium salt (solid, without solvent). Accordingly,
the proportion of the ammonium salt is likewise from 1 to 99% by
weight, preferably from 10 to 90% by weight and particularly
preferably from 30 to 70% by weight.
[0076] A mixture of polyvinylamine and ammonium salt is preferably
used; in particular, it is an aqueous solution which comprises the
two constituents. It preferably comprises from 0.01 to 5% by weight
of biocide (sum of polymer and ammonium salt). Treatment of the
paper or of the paper product over the whole area with the solution
or dispersion, i.e. preferably printing of the biocide according to
a pattern on the substrate, can be effected at room temperature or
directly after sheet formation in the papermaking process before,
during or after drying. After the drying, the paper or paper
product is appropriately finished.
[0077] The amount of biocide (sum of polymer and ammonium salt) is
preferably from 0.001 to 1000 mg, particularly preferably from 0.1
to 10 mg, per square meter of surface of the substrate to be
finished with the biocide.
[0078] The substrates finished with the biocide may be, for
example, products for medical applications, applications in the
sanitary or hygiene area, in the food area, in particular in food
packaging, or substrates for a wide range of industrial
applications, in particular filters, for example for
air-conditioning systems.
[0079] Compared with the known impregnation processes, the process
according to the invention has the advantage that substantially
smaller amounts of finishing agent are required for approximately
comparable properties of the papers and paper products and hence
papers and paper products can be more economically produced.
[0080] Unless otherwise evident from the context, the stated
percentages in examples are percent by weight.
EXAMPLE
Determination of the Stiffness
[0081] A DIN A4 sheet was printed according to the invention with a
finishing agent, dried, and conditioned for 24 hours at 25.degree.
C. and 60% relative humidity. The measurements were carried out at
room temperature under the respective prevailing air pressure. A
test piece having the dimensions 100.times.100 mm was cut from the
center of the DIN A4 sheet printed according to the invention with
the finishing agent. The test piece was then fixed between two
blocks of wood so that 50% of the test piece projected. That part
of the test piece which projected from the block was then loaded
with weights of from 1 to 50 g by placing the weights in the middle
of the test piece at a distance of 10 mm from the outer edge. As
soon as the end of the test piece projecting from the block had
reached 25 mm or the weight had fallen from the paper, the load
required for this purpose in g was measured as a measure of the
stiffness.
[0082] The following finishing agents were used: [0083] Finishing
agent 1: Mixture of a polycarboxylic acid and a polyfunctional
amine in the form of a 35% strength aqueous solution (Acrodur.RTM.
950L) [0084] Finishing agent 2: Mixture of a polycarboxylic acid
and a polyfunctional amine in the form of a 35% strength aqueous
dispersion (Acrodur.RTM. D3515) [0085] Finishing agent 3: 70%
strength aqueous solution of a heat-curable urea-formaldehyde resin
(Fixapret.RTM. ECO)
Examples 1 to 36 and Comparative Examples 1 to 16
[0086] DIN A4 sheets were each printed with the amounts of
finishing agents stated in the table below with the aid of the
inkjet printing process in the pattern likewise stated in the
table. The sheets printed with the finishing agents 1 to 3 were
each stored for 15 minutes at 140.degree. C. in order to crosslink
the polymers. Thereafter, the stiffness of the paper was determined
in each case by the method described above. The results are shown
in the table.
[0087] In the table, "Line (MD)" denotes lines which are printed on
the DIN A4 sheet and which run in the machine direction of the
sheet during papermaking and "Line (CD)" denotes lines which are
printed on and run transverse to the machine direction.
[0088] In comparative examples 1 to 6, water was printed on the
sheet in the print patterns stated in the table, and the sheet thus
treated was dried in each case before the determination of the
stiffness.
TABLE-US-00001 TABLE Stiffness Solids Amount Stiffness transverse
Finishing content printed on in machine to machine agent No. [%]
Printed pattern [g/m.sup.2] direction direction Example No. 1 1
12.5 Line (MD) 5 15 1 2 1 12.5 Line (CD) 5 1 20 3 1 12.5 Spiral 5 7
6 4 1 12.5 Concentric 5 7 7 circles 5 1 12.5 Square 5 10 1 6 1 12.5
Rhombus 5 20 9 7 1 25 Line (MD) 15 18 1 8 1 25 Line (CD) 20 1 16 9
1 25 Spiral 15 12 12 10 1 25 Concentric 15 12 12 circles 11 1 25
Square 20 12 1 12 1 25 Rhombus 15 22 22 13 2 12.5 Line (MD) 5 17 1
14 2 12.5 Line (CD) 5 2 23 15 2 12.5 Spiral 5 14 12 16 2 12.5
Concentric 4 17 17 circles 17 2 12.5 Square 5 25 6 18 2 12.5
Rhombus 4 7 12 19 2 25 Line (MD) 12 12 7 20 2 25 Line (CD) 15 1 24
21 2 25 Spiral 14 19 19 22 2 25 Concentric 20 21 19 circles 23 2 25
Square 14 >30 4 24 2 25 Rhombus 8 27 9 25 3 12.5 Line (MD) 4 7 1
26 3 12.5 Line (CD) 5 1 5 27 3 12.5 Spiral 4 6 7 28 3 12.5
Concentric 4 6 6 circles 29 3 12.5 Square 4 8 1 30 3 12.5 Rhombus 4
8 4 31 3 25 Line (MD) 20 16 1 32 3 25 Line (CD) 16 1 17 33 3 25
Spiral 17 12 12 34 3 25 Concentric 15 9 8 circles 35 3 25 Square 11
19 2 36 3 25 Rhombus 8 10 4 Comparative examples 1 Water Line (MD)
0 6 1 2 Water Line (CD) 0 6 1 3 Water Spiral 0 6 1 4 Water
Concentric 0 4 1 circles 5 Water Square 0 5 1 6 Water Rhombus 0 5 2
7 1 Whole area 5 5 1 8 1 Whole area 20 7 2 9 1 Whole area 100 22 20
10 2 Whole area 5 4 1 11 2 Whole area 20 7 2 12 2 Whole area 100 25
23 13 3 Whole area 5 5 1 14 3 Whole area 20 6 3 15 3 Whole area 100
20 23 16 Unprinted 6 1 and uncoated test paper
* * * * *