Note: Descriptions are shown in the official language in which they were submitted.
CA 02678313 2009-09-10
HEAT, GREASE, AND CRACKING RESISTANT RELEASE PAPER AND PROCESS FOR
PRODUCING THE SAME
TECHNICAL FIELD OF THE INVENTION
The present invention relates to papermaking processes and products made
through these processes. More particularly, the invention relates to a
composition and a
process for obtaining a heat, grease, and cracking resistant release paper,
starting from
the combination of cellulose fiber, one or more sizing agents, one or more
fillers, and one
or more binding agents.
BACKGROUND OF THE INVENTION
At present, a variety of paper used to wrap fatty foods, consists of cellulose
fibers
or derivatives to which a mixture of oil, grease or wax is added with organic
dissolvents;
said mixture is added during or after the production of the development paper
pulp,
which is then treated by heat and pressure to obtain a greaseproof paper.
However, this
paper proves to be inconvenient to wrap food, because of the possible risk of
dissolvent
residues, also it can not be used to warm foods wrapped in it as it does not
withstand
high temperatures.
Another current variation of greaseproof paper used to wrap foods is the paper
coated with paraffin on one or both sides, and for the manufacture of which
liquid wax is
applied in conventional coating machines and with a rubber cylinder to reduce
the coating
to a suitable thickness. The disadvantages of this type of papers are that the
hard
paraffin papers are cracking at the least flexion, whereas the smooth paraffin
papers
1
CA 02678313 2009-09-10
' . .
release grease, and particularly they are not appropriate to wrap sensitive
products to
said papers, moreover they cannot be submitted to high temperatures in order
to warm
wrapped foods.
One more variant of greaseproof paper used to wrap foods, are so-called
plastic-
coated papers laminated on one or both sides. This type of paper has the
disadvantage
that it can not be submitted to high temperatures, because of the risk of
being consumed
and releasing toxic components.
Other grease resistant or greaseproof types of paper are described in the
following
patent documents:
Donald K. Pattilloch and Carl Polowczyk, in US patent US-2,957,796 Al,
describe a
resistent paper made from the reaction of cellulose fibers with
polyethyleneimine and
perfluoroalkanoic acid.
Ajit S. Dixit, et al., in US patent US-7,019,054 B2, describe a oil and grease
resistant paper made from the reaction of cellulose fibers with polyvinyl
alcohol and fatty-
acid melanin wax.
Charles W. Propst Jr, in the US patent application US-2004/185286 Al,
describes a
grease, oil or wax resistant paper made from a substratum of cellulose fibers,
covered
with a layer based on a material serving as a filler material selected from
clay, sodium
hexametaphosphate, titanium dioxide and talc; a binding agent selected from
latex,
polyvinyl chloride, polyvinyl acetate, acrylate, maleic acid and protein; and
calcium
carbonate basically free from surfactants.
2
CA 02678313 2009-09-10
Richard F. Rudolph, et al., in the published international patent application
WO-
07014148, describes a grease resistant paper with glueability properties
formed by
cellulose fibers with a fluorocarbon-containing compound, so that this
compound is
dispersed from 5% to 100% in the web of cellulose fibers.
The limitation of these papers described in said patent documents is their low
resistance to heat; therefore, a food product that is wrapped with this paper
can not be
heated in an oven.
In view of this, exist the so-called heat or high temperature resistant
papers,
which can be used to wrap food and heat it in this way in an oven, however,
these papers
have the limitation that they are not waterproof or resistant to grease or
liquids.
Examples of these heat resistant papers are described in the following patent
documents:
Uwe Becker in the publication of the European patent application EP-1,000,198,
describes a high temperature resistant paper composed of a mixture of
cellulose fibers
and silica fibers, cut and thermally contracted. The silica fibers contain 80
% to 99.98 %
of silicon dioxide.
Tirone Cornbower, in the publication of the Mexican patent application MX-
PA04009912, describes a laminated paper structure consisting of two outer
layers and at
least one inner layer. The outer layers are formed by substantially cellulose
pulp and the
inner layer of 60 A, to 80 % by weight of cellulose pulp fiber with 5 % to 15
% by weight
of a high temperature resistant fiber, for example, polyaramide fibers, and 10
% to 25 %
of a polymeric binding agent, for example, of polyvinyl alcohol.
3
_ .
CA 02678313 2009-09-10
Junichi Hoshino and Kosaku Nagashima, in the publication of Japanese patent
application JP-2006291383, describe a heat resistant and release paper made
from a
natural paper as a base paper, which is impregnated with an acrylic resin and
coated on
one of its surfaces with polyvinyl alcohol, and has a coating of a release
agent.
In view of the above, it is therefore necessary to provide a paper that is
heat
resistant, resistant or impervious to liquids, grease or oil, resistant to
cracking, and has
release properties, which can be used as wrapping paper for food and which,
therefore
can be introduced, along with the wrapped food in any type of current oven
without any
risk of burning the paper, releasing residues, adhering to the food, cracking,
or allowing
the passage of liquids or greases released by the heated food, and further, is
not
unpleasant to sight and touch.
SUMMARY OF THE INVENTION
In view of the above, and with the object of finding solutions to the
limitations
encountered, it is the object of the invention to provide a heat, grease, and
cracking
resistant release paper, composed from 55 % to 68 % in weight of cellulose
fiber, from 3
% to 6 % by weight of one or more sizing agents, from 27 % to 37 % by weight
of one or
more fillers, and from 1 % to 3 % by weight of one or more binding agents.
Another object of the invention is to provide a process for producing a heat,
grease, and cracking resistant release paper, the process contains the steps
of forming a
paper pulp from a mixture from 55 % to 68 % by weight of cellulose fibers,
from 6 % to
7.5 % by weight of one or more fillers, and from 0.03 % to 0.05 % by weight of
one or
4
. _
CA 02678313 2009-09-10
more binding agents; reacting the paper pulp with from 1.5 % to 2.4 % by
weight of one
or more sizing agents, from 17 % to 27 (3/0 by weight of one or more fillers,
and from 0.7
% to 1.2 % by weight of one or more binding agents; forming and drying a
continuous
sheet of paper from the paper pulp; and reacting the continuous sheet of paper
with from
1.5 % to 3.6 % by weight of one or more sizing agents, from 2.5 % to 4 % by
weight of
one or more fillers, and from 0.27 % to 1.75 % by weight of one or more
binding agents.
DETAILED DESCRIPTION OF THE INVENTION
The characteristic details of this invention are described in the following
paragraphs, which have the objective of defining the invention, but without
limiting its
scope.
The composition of the paper according to the invention shows components that
in
turn may consist of multiple components. The components are described
individually
below, without necessarily being described in any order of importance.
CELLULOSE FIBER
The present invention includes cellulose fibers commonly referred to as wood
pulp
fibers, obtained from raw materials containing hardwood pulp, softwood pulp,
or
combinations thereof.
The terms "hardwood pulp" and "softwood pulp" refer to species of trees from
which wood is obtained that serves as a raw material to make paper; so, the
hardwood
pulp is obtained mainly from trees of the gymnosperm species or conifers such
as pine or
fir, while the softwood pulp is obtained from trees of the angiosperm species
or flowering
5
CA 02678313 2009-09-10
trees such as oak, birch or maple. The fiber length of hardwood pulp ranges
between 0.2
mm to 0.8 mm, and the fiber length of softwood pulp ranges between 0.8 mm to
4.5 mm.
Furthermore, these terms also refer to the grade of hardness of the wood.
The cellulose fibers for the paper of this invention can be obtained from the
raw
material through numerous chemical processes, known in the state of the art to
produce
paper pulp, and this in turn can undergo a process of decoloring, if desired.
In the composition of the paper of this invention, the range of the cellulose
fiber
.. content is from 55 % to 68 % by weight, where the content of hardwood pulp
in relation
to the content of softwood pulp varies between 0 % to 100 %, and from 100 % to
0 %
respectively. The preferred range of content of the softwood pulp is from 70 %
to 85 %,
and of the hardwood pulp is from 15 % to 30 /0.
SIZING AGENTS
In order to increase the resistance to moisture absorption and the resistance
to
the passage of liquids, for example, water, oil or grease, as well as to
obtain a smooth
surface finish of the paper of the present invention, one or more sizing
agents are
incorporated, which are selected from and alkyl ketene dimer and derivatives,
alkenyl
succinic anhydride, calcium stearate, cellulose stearate, cellulose and
combinations
thereof.
In accordance with the stages of a paper making process of the prior art, an
internal sizing of the paper of the invention can be performed during or after
the stage of
.. refining the paper pulp, by applying alkyl ketene dimer and derivatives,
and alkenyl
succinic anhydride, and a superficial sizing can be performed during a sizing
stage by
6
CA 02678313 2009-09-10
pressing, applying an alkyl ketene dimer and derivatives, alkenyl succinic
anhydride,
calcium stearate, cellulose stearate, and combinations thereof. For an
effective sizing, it is
convenient that the sizing agent is distributed evenly across the fibers of
the paper pulp,
which is recommended to prepare emulsions or dispersions containing an aqueous
phase
and finely divided particles of sizing agents dispersed in the same, and with
the use of
emulsion stabilizers. The emulsion stabilizers or binding agents commonly used
to
prepare such emulsions are, for example, starches and cationic polymers that
are
described below.
In an embodiment of the invention, one or more sizing agents are used from 3
A)
to 6 % by weight, and particularly from 2.5 % to 5 % by weight of alkyl ketene
dimer and
its derivatives, and from 0.5 % to 1 % by weight of calcium stearate.
FILLERS
In order to increase the heat resistance of the paper of the present invention
and
serve as a sealant for the same, microparticles of fillers are incorporated,
which are
selected of calcium carbonate, granulated calcium carbonate, precipitated
calcium
carbonate, kaolin, titanium dioxide, rutile titanium dioxide, anatasic
titanium dioxide,
hydrated aluminum silicate, talc, and combinations thereof.
The calcium carbonate, granulated calcium carbonate and/or precipitated
calcium
carbonate are basically used to increase the resistance to heat of the paper
of this
invention; whereas the release property, the opacity, as well as the whiteness
of the
paper of this invention improves through the incorporation of the rutile
titanium dioxide
and/or anatasic titanium dioxide.
7
CA 02678313 2009-09-10
In a process for producing paper according to prior art, the fillers can be
added
during the preparation and refining of the paper pulp, as well as once the
paper is made
during the sizing stage by pressing.
In a preferred embodiment of the invention, one or more fillers from 27 % to
37 %
by weight are used, and particularly from 26.8 % to 36 % by weight of calcium
carbonate, and from 0.2 % to 1 % by weight of titanium dioxide.
BINDING AGENTS
In order to increase the resistence of the paper of the invention and serve as
a
sealant against the passage of liquids through the same, one or more binding
agents are
incorporated, such as starch, cationic starch, cationic amylopectin starch,
acetylated
starch, ethylated starch, polyvinyl alcohol, carboxy-methyl cellulose, anionic
polyacrylamide, cationic polyacrylamide, epichlorohydrin polyamine, polyvinyl
acetate,
polyacrylates, polyacrylic acid, polystyrene, amylopectin-2-hydroxy-3-
(trimethylammonium) propyl ether chloride, and combinations thereof.
According to the invention, the use of cationic starch is preferred, in
particular
cationic amylopectine starch can be prepared from treating amylopectin starch
with a
cationic agent such as 3-chloro-2-hydroxypropyl (trimethylammonium) chloride,
2,3-
epoxypropyl (trimethylammonium) chloride, or 2-chloro ethyl
(trimethylammonium)
chloride, obtaining, for example, amylopectin-2-hydroxy-3-(trimethylammonium)
propyl
ether chloride.
The cationic amylopectin starch can be added at any point in the process for
producing the paper, for example, during or after the refining stage of the
paper pulp. If
8
CA 02678313 2009-09-10
necessary, in addition to the cationic amylopectin starch, cationic starch can
also be
added to the paper pulp.
The cationic starch can be made through chemical modification of the starch,
or
just by boiling the raw starch and adding a cationic polymer of low molecular
weight
before, during or after the boiling, for example, cationic polyacrylamide.
The starch, the cationic starch, the cationic amylopectine starch, acetylated
starch,
ethylated starch, and amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether
chloride are used as reinforcement supports.
On the one hand, epichlorohydrin polyamine resins, anionic polyacrylamide
resins,
and mixtures thereof act as binding agents to determine and uniformly deposit
the fillers
in the cellulose fiber, whereas the acetylated starch, ethylated starch,
cellulose
carboxymethyl resins, cationic polyacrylamide resins, polyvinyl alcohol
resins, starch,
cationic starch, cationic amylopectin
starch, amylopectin-2-hydroxy-3-
(trimethylammonium) propyl ether chloride, and mixtures thereof act as binding
agents
for resistance to the traction of the paper in the dry state, and in
particular the
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride improves the
resistance to tearing. Whereas on the other side, the sodium polyacrylate acts
as a
disperser.
In a preferred embodiment of the invention, one or more binding agents from 1
%
to 3 % by weight are used, and particularly from 0.8 % to 1.6 % by weight of
acetylated
starch, from 0.1 % to 0.4 % by weight of anionic polyacrylamide, from 0.05 %
to 0.25 %
by weight of sodium polyacrylate, from 0.01 % to 0.07 % by weight of
epichlorohydrin
9
CA 02678313 2009-09-10
polyamine, from 0.3 A, to 0.6 % by weight of cationic starch, and from 0.01 %
by weight
to 0.07 % by weight of amylopectin-2-hydroxy-3-(trimethylammonium) propyl
ether
chloride.
COMPOSITION OF THE PAPER OF THE INVENTION
The paper producted according to this invention presents a composition from 55
%
to 68 % by weight of cellulose fibers; from 3 % to 6 % by weight of one or
more sizing
agents; from 27 % to 37 % by weight of one or more fillers; and from 1 % to 3
% by
weight of one or more binding agents.
Where the contents of the cellulose fiber, from 70 % to 85 % is softwood pulp
and
from 15 % to 30 % is hardwood pulp; the contents of the sizing agents, from
2.5 % to 5
% by weight is alkyl ketene dimer and its derivatives, and from 0.5 % to 1% by
weight is
calcium stearate; the contents of the fillers is from 26.8 % to 36 % by weight
is calcium
carbonate, and from 0.2 % to 1 % by weight is titanium dioxide; and the
content of the
binding agents is from 0.8 % to 1.6 % by weight of acetylated starch, from 0.1
% to 0.4
% by weight of anionic polyacrylamide, from 0.05 % to 0.25 % by weight of
sodium
polyacrylate, from 0.01 % to 0.07 % by weight of epichlorohydrin polyamine,
from 0.3 %
to 0.6 % by weight of cationic starch, and from 0.01 % to 0.07 % by weight of
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride.
PROCESS FOR PRODUCING THE PAPER OF THE INVENTION
The heat, grease, and cracking resistant release paper of the invention, is
produced from a paper pulp with a mixture from 55 % to 68 % by weight of
cellulose
fiber, whereas from 70 % to 85 % of the cellulose fiber is softwood pulp, and
from 15 %
to 30 % is hardwood pulp; from 6 % to 7.5 % by weight of one or more fillers,
preferably
CA 02678313 2009-09-10
calcium carbonate, and from 0.03 % to 0.05 % by weight one or more binding
agents,
preferably epichlorohydrin polyamine.
Then, during or after a stage of refining, the paper pulp reacts with from 1.5
% to
2.4 % by weight of one or more sizing agents, preferably alkyl ketene dimer;
with from
17 % to 27 % by weight of one or more fillers, preferably granulated calcium
carbonate;
and with from 0.7 % to 1.2 % by weight of one or more binding agents,
preferably from
0.35 % to 0.57 % by weight of cationic starch, from 0.24 % to 0.37 % by weight
of
anionic polyacrylamide, and from 0.11 % to 0.17 % by weight of sodium
polyacrylate.
Subsequently, a continuous dry sheet of paper is formed, which is reacted with
from 1.5 % to 3.6 % by weight of one or more sizing agents, preferably from 1
% to 2 %
by weight of alkyl ketene dimer, and from 0.5 % to 1.6 % by weight of calcium
stearate;
with from 2.5 % to 4 % by weight of one or more fillers, preferably from 1.78
% to 3.3 %
by weight of calcium carbonate and from 0.3 % to 0.7 % by weight of titanium
dioxide;
and with from 0.27 % to 1.75 % by weight of one or more binding agents,
preferably
from 0.25 % to 1.7 % by weight of acetylated starch and from 0.02 % to 0.05 %
by
weight of sodium polyacrylate.
MECHANICAL AND PHYSICAL PROPERTIES OF THE PAPER OF THE INVENTION
The produced paper according to the invention has the following physical and
mechanical properties, shown in Table 1 according to standards and methods of
the
Technical Association of Pulp and Paper Industry known by its initials in
English as TAPPI.
TAPPI
Property Unit Objective Minimum Maximum
Method
Base Weight g/m2 39 37 41 T-410
11
Humidity ok 4.0 3.5 4.5 T-412
Thickness in x 10-3 2.3 2.1 2.5 T-411
Gurley Porosity sec 15 5 30 T-460
Whiteness % PH 89 86 - T-452
Opacity /ci PH 78 74 - , T-425
Sizing COBB girt.12 12 10 14 T-441
Ashes iyo 20 17 23 T-413
Hue L L 95 93 97 T-524
Tone A a 1.0 0.0 2.0 T-524
Tone A b 0.0 -1.5 1.5 T-524
MD Tensile kg/15mm 2.0 1.6 - T-404
CD Tensile kg/15mm 1.4 0.8 - T-404
MD Tearing grams 12 10 - T-414
,
CD Tearing grams 14 12 - T-414
LF Sliding grades 27 25 30 T-548
LT Sliding grades 27 25 30 T-548
Clean S / M Good - - 6
Formation S/M Good - - Visual
COF Radians Good - 0.6 T-549
Table 1
EXAMPLES OF EMBODIMENTS OF THE INVENTION
The invention will now be described in reference to the following examples,
which
is solely for the purpose of presenting the way of carrying out the
implementation of the
principles of the invention. The following examples are not intended to be a
comprehensive presentation of the invention, nor try to limit the scope
thereof.
EXAMPLE 1
Paper pulp is prepared containing 655.50 kg of softwood pulp, 115.7 kg of
hardwood pulp, 85 kg of calcium carbonate, and 0.5 kg of epichlorohydrin
polyamine
resin per ton of produced paper. Next, during of after the refining stage,
this paper pulp is
increased by 6 kg of cationic starch or amylopectin-2-hydroxy-3-
(trimethylammonium)
12
CA 2678313 2018-06-11
-
CA 02678313 2009-09-10
propyl ether chloride, 25 kg of alkyl ketene dimer, 4 kg of anionic
polyacrylamide resin,
1.7 kg of sodium polyacrylate, and 286 kg of calcium carbonate per ton of
produced
paper. Once the continuous sheet of paper is produced, it is made to react by
a sizing
press with 0.3 kg of sodium polyacrylate, 16 kg of acetylated starch, 29 kg of
sodium
carbonate, 5 kg of rutile titanium dioxide, 10 kg of calcium stearate, and 20
kg of alkyl
ketene dimer per ton of produced paper.
EXAMPLE 2
The same preparation as in example 1, except that during the preparation of
the
paper pulp, 540 kg of softwood pulp and 231.35 kg of hardwood pulp are used
per ton of
produced paper.
EXAMPLE 3
Paper pulp is prepared containing 775.16 kg of softwood pulp, 85 kg of calcium
carbonate, and 0.5 kg of epichlorohydrin polyamine resin per ton of produced
paper.
Next, during of after a refining stage, this paper pulp is increased by 4.2 kg
of cationic
starch or amylopectin-2-hydroxy-3-(trimethylannmonium) propyl ether chloride,
17.5 kg
of alkyl ketene dimer, 2.8 kg of anionic polyacrylamide resin, 1.2 kg of
sodium
polyacrylate, and 220.2 kg of calcium carbonate per ton of produced paper.
Once the
continuous sheet of paper is produced, it is made to react by a sizing press
with 0.2 kg of
sodium polyacrylate, 11.2 kg of acetylated starch, 20.3 kg of sodium
carbonate, 3.5 kg of
rutile titanium dioxide, 7 kg of calcium stearate, and 24 kg of alkyl ketene
dimer per ton
of produced paper.
EXAMPLE 4
A paper pulp is prepared containing containing 775.16 kg of softwood pulp, 85
kg
13
CA 02678313 2009-09-10
of calcium carbonate, and 0.5 kg of epichlorohydrin polyamine resin per ton of
produced
paper. Later, during or after a refining stage, this paper pulp is increased
with 7.8 kg of
cationic starch or amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether
chloride,
32.5 kg of alkyl ketene dimer, 5.2 kg of anionic polyacrylamide resin, 2.2 kg
of sodium
plyacrylate, and 371.8 kg of calcium carbonate per ton of produced paper. Once
the
continuous sheet of paper is produced, it is made to react by a sizing press
with 0.4 kg of
sodium polyacrylate, 20.8 kg of acetylated starch, 37.7 kg of sodium
carbonate, 6.5 kg of
rutile titanium dioxide, 13 kg of calcium stearate, and 26 kg of alkyl ketene
dimer per ton
of produced paper.
EXAMPLE 5
Paper pulp is prepared containing 775.16 kg of softwood pulp, 85 kg of calcium
carbonate, and 0.5 kg of poliamin epichlorhydrine resin per ton of produced
paper. Later,
during or after a refining stage, this paper pulp is increased with 6 kg of
cationic starch or
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride, 25 kg of
alkyl
ketene dimer, 4 kg of anionic polyacrylamide resin, 1.7 kg of sodium
polyacrylate, and
286 kg of calcium carbonate per ton of produced paper. Once the continuous
sheet of
paper is produced, it is made to react by a sizing press with 0.3 kg of sodium
polyacrylate, 16 kg of acetylated starch, 29 kg of sodium carbonate, 5 kg of
rutile
titanium dioxide, 10 kg of calcium stearate, and 20 kg of alkyl ketene dimer
per ton of
produced paper.
EXAMPLE 6
The same preparation as in Example 5, except that it contains ethylated
starch,
not any other starch.
14
CA 02678313 2009-09-10
EXAMPLE 7
Paper pulp is prepared containing 775.16 kg of softwood pulp, 85 kg of calcium
carbonate, and 0.5 kg of epichlorhydrine poliamin resin per ton of produced
paper. Next,
during of after the refining stage, this paper pulp is increased by 6 kg of
cationic starch or
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride, 25 kg of
alkyl
ketene dimer, 4 kg of anionic polyacrylamide resin, 1.7 kg of sodium
polyacrylate, and
286 kg of calcium carbonate per ton of paper produced Once the continuous
sheet of
paper is produced, it is made to react by a sizing press with 0.3 kg of sodium
polyacrylate, 16 kg of acetylated starch, 29 kg of sodium carbonate, 5 kg of
rutile
titanium dioxide, 10 kg of calcium stearate and 20 kg of alkyl ketene dimer
per ton of
produced paper.
EXAMPLE 8
Paper pulp is prepared containing 775.16 kg of softwood pulp, 85 kg of calcium
carbonate, and 0,5 kg of epichlorhydrine poliamin resin per ton of produced
paper. Next,
during of after the refining stage, this paper pulp is increased by 6 kg of
cationic starch or
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride, 25 kg of
alkyl
ketene dimer, 4 kg of anionic polyacrylamide resin, 1.7 kg of sodium
polyacrylate, and
286 kg of calcium carbonate per ton of paper produced. Once the continuous
sheet of
paper is produced, it is made to react by a sizing press with 0.3 kg of sodium
polyacrylate, 16 kg of acetylated starch, 5 kg of rutile titanium dioxide, 10
kg of calcium
stearate, and 20 kg of alkyl ketene dimer per ton of produced paper.
EXAMPLE 9
Paper pulp is prepared containing 775.16 kg of softwood pulp, 85 kg of calcium
carbonate, and 0.5 kg of epichlorhydrine poliamin resin per ton of produced
paper. Next,
CA 02678313 2009-09-10
during of after the refining stage, this paper pulp is increased by 6 kg of
cationic starch or
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride, 25 kg of
alkyl
ketene dimer, 4 kg of anionic polyacrylamide resin, 1.7 kg of sodium
polyacrylate, and
286 kg of calcium carbonate per ton of paper produced. Once the continuous
sheet of
paper is produced, it is made to react by a sizing press with 0.3 kg of sodium
polyacrylate, 16 kg of acetylated starch, 29 kg of sodium carbonate, 5 kg of
rutile
titanium dioxide, 10 kg of calcium stearate, and 4 kg of alkenyl succinic
anhydride per ton
of produced paper.
EXAMPLE 10
Paper pulp is prepared containing 775.16 kg of softwood pulp, 85 kg of calcium
carbonate, and 0.5 kg of epichlorhydrine poliamin resin per ton of produced
paper. Next,
during of after the refining stage, this paper pulp is increased by 6 kg of
cationic starch or
amylopectin-2-hydroxy-3-(trimethylammonium) propyl ether chloride, 25 kg of
alkyl
ketene dimer, 4 kg of anionic polyacrylamide resin, 1.7 kg of sodium
polyacrylate, and
286 kg of calcium carbonate per ton of produced paper. Once the continuous
sheet of
paper is produced, it is made to react by a sizing press with 0.3 kg of sodium
polyacrylate, 16 kg of acetylated starch, 29 kg of sodium carbonate, 5 kg of
rutile
titanium dioxide, 10 kg of calcium stearate per ton of produced paper.
Four sample sheets from each of the examples 1 to 10 were submitted to
physical
tests to determine, through visual assessment, smell and touch, its heat
resistance,
grease resistance, resistance to cracking, and anti-adherent properties.
The tests consisted in placing in the center of sample sheet 1 a raw biscuit,
in the
center of sample sheet 2 a piece of 4 cm X 4 cm of a conventional slice of
yellow cheese,
16
CA 02678313 2009-09-10
in the center of sample sheet 3 a piece of approximately 4.5 cm x 2 cm of
conventional
slice of bacon, and nothing on sample 4. Each of the 4 samples for each of the
examples
1 to 10 were placed on a plastic tray and introduced separately in a cooking
oven by
combination of hot air, microwave and infrared heating of the TurboChef@
brand, model
Tornado manufactured by TurboChef Technologies, Inc. at a cooking temperature
of
about 260 C to 345 C for 20 seconds and that was previously started for
three hours.
Later, each sample is removed from the cooking oven, and then the samples 1, 2
and 3
are removed, the biscuit, yellow cheese and bacon respectively, and thus
evaluate the
degree of heat resistance, resistance to grease, resistance to cracking and
release
properties of each of the samples for each of the examples.
The results obtained from the former samples are shown in Table 2, with the
value
of the grade of resistance to heat, resistance to fat, resistance to cracking
and release on
a scale from 0 to 5, where:
For the testing of resistance to fat and release:
0 means very bad, that is, grease passes completely through the paper and
the cheese, bacon or biscuit sticks to said sample paper.
1 means bad, that is, grease passes through the paper and approximately
3/4 parts of the cheese, bacon or biscuit that was in contact with the paper,
sticks
to said sample paper.
2 means regular, that is, grease passes slightly through the paper and
approximately 2/4 parts of the cheese, bacon or biscuit that was in contact
with
the paper, sticks to said sample paper.
3 means good, that is, a small spot of grease is observed on the paper, and
small pieces of cheese, bacon or biscuit stick to said sample paper.
17
CA 02678313 2009-09-10
4 means very good, that is, a very small spot of grease is observed on the
paper, and no residues of cheese, bacon or biscuit stick to said sample paper.
means very good, that is, a very small spot of grease is observed on the
paper, and there are no residues of cheese, bacon or biscuit stuck to said
sample
5 paper.
For the testing of resistance to heat:
0 means very bad, that is, the entire sample paper is dark brown compared
with a sample of the paper that was not submitted to the test.
1 means bad, that is, the sample paper surface is approximately 80 % dark
brown and the rest of its surface is light brown compared with a sample of the
paper that was not submitted to the test.
2 means regular, that is, the sample paper surface is approximately 50 %
dark brown and the rest of its surface is light brown compared with a sample
of
the paper that was not submitted to the test.
3 means good, that is, the sample paper surface is approximately 30 %
light brown and the rest of its surface is yellowish compared with a sample of
the
paper that was not submitted to the test.
4 means very good, that is, the sample paper surface is approximately 20
% yellowish and the rest of its surface is very light brown compared with a
sample
of the paper that was not submitted to the test.
5 means excellent, that is, the entire sample paper does not show any
degradation in color compared with a sample of the paper that was not
submitted
to the test.
For the testing of resistance to cracking:
18
_ -
CA 02678313 2009-09-10
0 means very bad, that is, the entire sample paper is completely torn to
pieces.
1 means very bad, that is, the sample paper is cracked over approximately
3/4 parts.
2 means regular, that is, the sample paper is slightly torn over
approximately 2/4 parts.
3 means good, that is, the sample paper is only crumpled over
approximately 3/4 parts, but this area is not cracked.
4 means very good, that is, the sample paper is only crumpled over
approximately 2/4 parts, but this area is not cracked.
5 means excellent, ie the sample of paper slightly crumples and does not
break.
Test Sample 1
Example 1 Example 2 Example 3 Example 4
Example 5
Heat
4.5 4.5 4.5 5 4.5
resistance
Grease
5 5 5 5 5
Resistance
Release 4 4 4 4 4
Example 6 Example 7 Example 8 Example 9
Example 10
Heat
4.5 4.5 4.5 4.5 4.5
resistance
Grease
5 5 5 5 5
Resistance
Release 4 3.5 4 4 4
Test Sample 2
EXAMPLE 1 EXAMPLE 2 EXAMPLE 3 EXAMPLE 4
EXAMPLE 5
Heat
4 4.5 4.5 5 5
resistance
Grease
4.5 3.5 4 4 4
Resistance
Release 4 4.5 3.5 4.5 5
EXAMPLE 6 EXAMPLE 7 Example 8 Example 9
Example 10
Heat
4.5 4.5 5 5 4.5
resistance
Grease
4 4 4 4.5 3.5
Resistance
19
CA 02678313 2009-09-10
Release 5 4 4
Sample 3
Test
Example 1 Example 2 Example 3
Example 4 Example 5
Heat
4.5 4.5 5 5 4.5
resistance
Grease
4 5 4 4.5 4
Resistance
_ Release 5 5 5 4.5 5
Example 6 Example 7 Example 8
Example 9 Example 10
Heat
5 5 5 5
resistance _
Grease
4.5 4.5 4 4.5 4
Resistance -
Release 4.5 4.5 4 4.5 5
Sample 4
Test
Example 1 Example 2 _ Example 3
Example 4 Example 5
Heat
4.5 4.5 4.5 4.5 4
resistance
Resistance to
5 5 4.5 4.5 5
cracking
, Example 6 _ Example 7 Example 8 Example 9 , Example 10
Heat
4.5 4.0 4.5 4.0 3.5
resistance
Resistance to
4.5 4.0 5.0 4.5 4.5
cracking
Table 2
Finally, it must be understood that the heat, grease, and cracking resistant
release
5 paper, and the process for producing it according to the invention are
not limited to the
embodiments or modalities described above and before, and that the experts in
the field
will be trained by the training set established herein to perform changes in
the
composition of the paper and the conditions of the processof the present
invention, whose
scope will be established exclusively by the following claims:
20
,
,
