Technical Field
[0001] The present invention relates to a method for packaging a cellulosic polymer and
applications of the same.
Background Art
[0002] Polymers derived from cellulose, such as hydroxyethyl cellulose, carboxymethyl cellulose,
hydroxymethyl cellulose, and hydroxypropyl cellulose, are used in various fields,
such as medicine and food, due to their high safety. For example, carboxymethyl cellulose
is used in thickeners and emulsion stabilizers in foods, such as ice cream, as well
as in non-food products, such as toothpastes, laxatives, diet tablets, aqueous inks,
surfactants, and paper products.
[0003] Conventionally, cellulosic polymers are typically stored in powder form. However,
the viscosity of the solution of the cellulosic polymer stored for a long period of
time is greatly reduced as compared with the viscosity of the solution of the cellulosic
polymer before storage, and thus there has been a problem that the cellulosic polymer
cannot function as a viscosity regulator.
[0004] Therefore, Patent Document 1 proposes a storage method for suppressing viscosity
reduction due to oxidation or others by keeping the oxygen concentration in the packaging
bag at a constant level or less.
Citation List
Patent Literature
Summary of Invention
Technical Problem
[0006] Patent Document 1 proposes a method of reducing the residual oxygen concentration
in the packaging bag as much as possible by nitrogen substitution to decrease the
viscosity reduction to the maximum extent; however, the nitrogen substitution in the
packaging bag to the maximum extent would inflate the packaging bag by internal pressure,
thereby making it difficult to pack the packaging bag or to mutually stack the packaging
bags for transportation.
[0007] In view of the above, one of the problems to be solved is to provide a packaging
method suitable for transporting a cellulosic polymer.
[0008] In addition, one of the further problems to be solved is to provide a packaging method
suitable for transportation or others while suppressing the viscosity reduction of
the cellulosic polymer.
Solution to Problem
[0009] The invention presented in the present disclosure can be perceived in various aspects,
and, for example, may include for solution(s) to the problem(s), as follows. That
is, the present invention has the following aspects [1] to [20].
- [1] A method for packaging a cellulosic polymer, comprising: filling a packaging bag
having a gas barrier property with the cellulosic polymer; and sealing the packaging
bag.
- [2] The method for packaging a cellulosic polymer according to the above item [1],
wherein the method satisfies the following conditions (1) to (3):
- (1) the packaging bag having the gas barrier property is filled with the cellulosic
polymer;
- (2) an oxygen concentration in the packaging bag is adjusted to 0.8% or less and the
packaging bag is sealed; and
- (3) when the packaging bag filled with the cellulosic polymer is placed such that
the longest long side L is horizontal, the depth D of the packaging bag from the horizontal
plane and the long side L satisfy a relational expression of 6.1 ≤ L/D ≤ 10.
- [3] The method for packaging a cellulosic polymer according to the above item 1 or
2, wherein the longest long side L of the packaging bag filled with the cellulosic
polymer has a length of 700 mm or more and 1,100 mm or less.
- [4] The method for packaging a cellulosic polymer according to any one of the above
items [1] to [3], wherein a short side W of the packaging bag perpendicular to the
long side L of the packaging bag filled with the cellulosic polymer has a length of
400 mm or more and less than 700 mm.
- [5] The method for packaging a cellulosic polymer according to any one of the above
items [1] to [4], wherein the depth D of the packaging bag filled with the cellulosic
polymer is less than 130 mm.
- [6] The method for packaging a cellulosic polymer according to any one of the above
items [1] to [5], comprising: filling the packaging bag having a gas barrier property
with a cellulosic polymer, the packaging bag having an outermost layer with a surface
satisfying a range of a static friction coefficient of 0.2 to 0.5 and a dynamic friction
coefficient of 0.15 to 0.35.
- [7] The method for packaging a cellulosic polymer according to the above item [6],
wherein the outermost layer of the packaging bag satisfies a range of a smoothness
of 2 to 10 seconds.
- [8] The method for packaging a cellulosic polymer according to the above item [6]
or [7], wherein the outermost layer of the packaging bag is a paper base material.
- [9] The method for packaging a cellulosic polymer according to any one of the above
items [6] to [8], wherein the outermost layer of the packaging bag satisfies a range
of a basis weight of 50 to 100 g/m2.
- [10] The method for packaging a cellulosic polymer according to any one of the above
items [1] to [9], wherein the cellulosic polymer is carboxymethyl cellulose.
- [11] The method for packaging a cellulosic polymer according to any one of the above
items [1] to [10], wherein after the inside of the packaging bag is vacuum-treated,
nitrogen substitution is conducted to adjust the oxygen concentration to 0.8% or less.
- [12] The method for packaging a cellulosic polymer according to any one of the above
items [1] to [11], wherein the packaging bag has an internal pressure of 85 kPa or
less.
- [13] A method for transporting a cellulosic polymer, comprising: stacking packaging
bags obtained by the method for packaging a cellulosic polymer according to any one
of the above items [1] to [12] and transporting the packaging bags to a destination.
- [14] The method for transporting a cellulosic polymer according to the above item
[13], wherein the packaging bags are stacked in two layers or more and ten layers
or less.
- [15] A cellulosic polymer package, comprising: a sealed packaging bag and a cellulosic
polymer filled in the packaging bag under the following conditions (1) to (3):
- (1) the packaging bag having a gas barrier property is filled with the cellulosic
polymer;
- (2) an oxygen concentration in the packaging bag is adjusted to 0.8% or less before
sealing; and
- (3) when the packaging bag filled with the cellulosic polymer is placed such that
the longest long side L is horizontal, the depth D of the packaging bag from the horizontal
plane and the long side L satisfy the relational expression of 6.1 ≤ LID ≤ 10.
- [16] The cellulosic polymer package according to the above item [15], wherein the
packaging bag has an outermost layer with a surface satisfying a range of a static
friction coefficient of 0.2 to 0.5 and a dynamic friction coefficient of 0.15 to 0.35.
- [17] The cellulosic polymer package according to the above item [15] or [16], wherein
the cellulosic polymer is carboxymethyl cellulose.
- [18] The cellulosic polymer package according to any one of the above items [15] to
[17], wherein the packaging bag has an oxygen concentration of more than 0.3% and
0.8% or less.
- [19] The cellulosic polymer package according to any one of the above items [15] to
[18], wherein the packaging bag has an internal pressure of 85 kPa or less.
- [20] The cellulosic polymer package according to any one of the above items [15] to
[19], wherein the packaging bag has a two-layer structure or a three or more-layer
structure, the outermost layer of the packaging bag is a paper base material, and
at least one of the inner bag layers inside the outermost layer is a gas barrier layer.
Advantageous Effects of Invention
[0010] One aspect of the present invention can provide a packaging method suitable for,
e.g., transportation of a cellulosic polymer.
[0011] In addition, one aspect of the present invention can provide a packaging method suitable
for, e.g., transportation of a cellulosic polymer while suppressing the viscosity
reduction of the cellulosic polymer.
[0012] Further, one aspect of the present invention can provide a cellulosic polymer package
suitable for, e.g., transportation.
[0013] Further, one aspect of the present invention can provide a package suitable for,
e.g., transportation of a cellulosic polymer while suppressing viscosity reduction
of the cellulosic polymer.
Brief Description of Drawings
[0014] FIG. 1 is a view illustrating a packaging bag filled with a cellulosic polymer, wherein
the packaging bag is placed such that the longest long side L is horizontal to a horizontal
placement plane (horizontal plane), in which D represents the depth from the horizontal
plane and W represents the short side in the width direction perpendicular to L.
Description of Embodiments
[0015] Embodiments of the present invention will be described below. In this disclosure,
unless otherwise stated, the expression "AA to BB" regarding numerical range refers
to "AA or more and BB or less" (where "AA" and "BB" are arbitrary values). Unless
otherwise stated, the units of the lower limit and upper limit are the same as the
unit added immediately after the latter (i.e., "BB" here). In addition, in the present
disclosure, the expression "X and/or Y" means both X and Y, or one of the two. In
the present disclosure, unless otherwise stated, a gas concentration is expressed
in terms of volume ratio. For example, the unit "%" or the oxygen concentration indicates
the percentage of the volume ratio (Vol/Vol) of oxygen.
1. FIRST EMBODIMENT OF THE PRESENT INVENTION
[0016] As one embodiment of the present invention, there is provided a method for packaging
a cellulosic polymer comprising: filling a packaging bag having a gas barrier property
with a cellulosic polymer; and sealing the packaging bag, wherein the method satisfies
the following conditions (1) to (3) (hereinafter also referred to as the first embodiment).
Condition (1): The packaging bag having gas barrier property is filled with a cellulosic
polymer.
Condition (2): An oxygen concentration in the packaging bag is adjusted to 0.8% or
less and the package bag is sealed.
Condition (3): When a packaging bag filled with a cellulosic polymer is placed such
that the longest long side L is horizontal, the depth D of the packaging bag from
the horizontal placement plane (horizontal plane) and the long side L satisfy the
relational expression of 6.1 ≤ L/D ≤ 10.
CELLULOSIC POLYMER
[0017] In the first embodiment of the present invention, the cellulosic polymer is not particularly
limited as long as it is a compound derived from cellulose, but is preferably chemically
modified, such chemical modification is to introduce a functional group into pulp,
and the chemical modification is preferably anionic modification, that is, the chemically
modified cellulose preferably has an anionic group. Examples of the anionic group
may include an acid group, such as a carboxyl group, a carboxyl group-containing group,
a phosphate group, a phosphate group-containing group, and a sulfate ester group.
Examples of the carboxyl group-containing group may include -COOH group, -R-COOH (R
is an alkylene group having 1 to 3 carbon atoms), and -O-R-COOH (R is an alkylene
group having 1 to 3 carbon atoms). Examples of the phosphate group-containing group
may include a polyphosphate group, a phosphite group, a phosphonic acid group, a polyphosphonic
acid group. Depending on reaction conditions, these acid groups may be introduced
in the form of salts (for example, carboxylate groups (-COOM, M is a metal atom)).
In the present invention, the chemical modification is preferably oxidation or etherification.
[0018] The oxidation can be carried out as is known. Examples may include oxidizing raw
pulp in water using an oxidizing agent in the presence of an N-oxyl compound and a
substance selected from the group consisting of bromide, iodide, and mixtures thereof.
This method selectively oxidizes the primary hydroxyl group at the C6 position of
the glucopyranose ring on the cellulose surface to produce a group selected from the
group consisting of an aldehyde group, a carboxyl group, and a carboxylate group.
Alternatively, an ozone oxidation method may be used. This oxidation reaction oxidizes
hydroxyl groups, at least at the 2-positon and the 6-position of the glucopyranose
ring constituting the cellulose, and decomposes the cellulose chain.
[0019] Examples of the etherification may include carboxymethylation (etherification), methylation
(etherification), ethylation (etherification), cyanoethylation (etherification), hydroxyethylation
(etherification), hydroxypropylation (etherification), ethylhydroxyethylation (etherification),
and hydroxypropyl methylation (etherification). Among these, carboxymethylation is
preferable. Carboxymethylation can be carried out, for example, by mercerizing raw
pulp as a starting raw material and then etherifying the mercerized raw pulp. Among
these, especially in the case of carboxymethylated cellulose, its viscosity reduction
can be prevented when it is made into an aqueous solution, and the packaging bag can
be made suitable for transportation or others.
[0020] Such carboxymethylated cellulose can generally be produced by treating (mercerizing)
the cellulose with an alkali and then causing the resulting mercerized cellulose (also
referred to as alkali cellulose) to react with a carboxymethylating agent (also referred
to as an etherifying agent).
[0021] In the first embodiment of the present invention, cellulose means a polysaccharide
having a structure in which D-glucopyranose (also referred to simply as "glucose residue"
or "anhydrous glucose") is connected by β-1, 4 bonds. Cellulose is generally classified
into natural cellulose, regenerated cellulose, fine cellulose, and microcrystalline
cellulose excluding non-crystalline regions, among other celluloses based on its origin
and manufacturing method, among other factors. In the present invention, any of these
celluloses can be used as a raw material for mercerized cellulose.
[0022] Examples of natural celluloses may include: bleached or unbleached pulp (bleached
or unbleached wood pulp); linter, purified linter; and cellulose produced by microorganisms
such as acetic acid bacteria. Examples of raw materials of bleached pulp or unbleached
pulp is not particularly limited and may include wood, cotton, straw, bamboo, hemp,
jute, and kenaf. Examples of the method for producing the bleached pulp or the unbleached
pulp is not particularly limited and may include a mechanical method, a chemical method,
or an intermediate method combining the two methods. Examples of the bleached pulp
or unbleached pulp classified by the production method may include: mechanical pulp
(thermomechanical pulp (TMP) and crushed wood pulp); and chemical pulp (sulfite pulps
such as unbleached softwood sulfite pulp [NUSP], bleached softwood sulfite pulp [NBSP],
and kraft pulps such as unbleached softwood kraft pulp [NUKP], bleached softwood kraft
pulp [NBKP], unbleached hardwood kraft pulp [LUKP], and bleached hardwood kraft pulp
[LBKP]). Dissolved pulp may be used in addition to paper pulp. Dissolved pulp is chemically
refined pulp that is mainly dissolved in chemicals and used as a main raw material
for artificial fibers, cellophane, and others.
[0023] The degree of carboxymethyl substitution per anhydrous glucose unit of the carboxymethylated
cellulose is preferably in the range of 0.2 to 1.5, more preferably in the range of
0.3 to 1.2, and still more preferably in the range of 0.5 to 1.0. When the degree
of carboxymethyl substitution is less than 0.2, the expression of viscosity does not
occur much when the carboxymethylated cellulose is made into an aqueous solution,
which limits the effect of the present invention. When the degree of carboxymethyl
substitution is more than 1.5, the viscosity reduction tends to occur, even using
the packaging method of the present invention, thus being not suitable.
[0024] In the first embodiment of the present invention, the anhydrous glucose unit means
each anhydrous glucose (glucose residue) constituting cellulose. The degree of carboxymethyl
substitution (also referred to as the degree of etherification) indicates the proportion
of the hydroxyl group that is substituted by the carboxymethyl ether group in the
glucose residue constituting cellulose (number of carboxymethyl ether groups per one
glucose residue). The degree of carboxymethyl substitution may be abbreviated as DS.
[0025] The degree of carboxymethyl substitution is measured by the following method.
[0026] First, precisely weighed about 2.0 g of a sample is put into a 300 mL stoppered Erlenmeyer
flask. Next, 100 mL of a liquid, the liquid being obtained by adding 100 mL of special
concentrated nitric acid to a solution of 1,000 mL of methanol, is added into the
flask, and shaken for 3 hours, thus converting the salt of carboxymethylcellulose
(CMC) into H-CMC (hydrogen-type carboxymethylcellulose). Precisely weighed 1.5 to
2.0 g of the absolutely dried H-CMC is put into a 300 mL stoppered Erlenmeyer flask.
The H-CMC is moistened with 15 mL of 80% methanol and added with 100 mL of 0.1 N NaOH,
and shaken at room temperature for 3 hours. Excess NaOH is back titrated with 0.1
N-H
2SO
4 by using phenolphthalein as an indicator, and the degree of carboxymethyl substitution
(DS value) is calculated by the following equation.
F' : Factor of 0.1N-H2SO4
F: Factor of 0.1N-NaOH
[0027] As the cellulosic polymer usable in the first embodiment of the present invention,
cellulose in a pulp-like material subjected to chemical modification may be used as
it is, or the pulp-like material may be used as powder produced by pulverization or
others. The pulp-like material may be defibrated to use as a dried material such as
cellulose in the form of microfibrils or cellulose in the form of nanofibers.
[0028] Cellulose nanofibers can be produced by applying a strong shear force to unmodified
cellulose raw material or chemically modified cellulose. In the first embodiment of
the present invention, the cellulose raw material may be unmodified or chemically
modified, but is more preferably chemically modified. As compared to cellulose nanofibers
manufactured by using an unmodified cellulose raw material, cellulose nanofibers manufactured
by using a chemically modified cellulose raw material have uniform fiber length and
fiber diameter and thus have stable dispersibility in water and are presumed to exhibit
superior effects. Examples of chemical modification are not particularly limited but
may include oxidation, etherification, phosphorylation, esterification, silane coupling,
fluorination, and cationization. Among these, any one of oxidation, carboxymethylation,
and cationization using an N-oxyl compound is preferable, and carboxymethylation or
oxidation is particularly preferable.
[0029] The cellulosic polymer used in the first embodiment of the present invention has
a dry solid content of preferably 60 % by weight or more, more preferably 70 % by
weight or more, and still more preferably 80 % by weight or more when filled in a
packaging bag. The dry solid content within this range can reduce the amount of divergence
of the equilibrium moisture in the package, thereby suppressing the deterioration
of the cellulosic polymer due to the moisture.
PACKAGING BAG
[0030] In the first embodiment of the present invention, any packaging bag can be used without
any particular restriction as long as the packaging bag has a gas barrier property.
In the present invention, "having a gas barrier property" means having a function
of suppressing permeation of oxygen, moisture, and the like. Such a packaging bag
is preferably formed by using: an aluminum having a high gas barrier property; a transparent
barrier film comprising polyacrylonitrile, polyvinyl alcohol, a nylon film having
a coating film of a polyvinylidene chloride resin, an ethylene-vinyl alcohol copolymer,
an olefin-based polymer, an olefin-polycarboxylic acid copolymer, or a plastic base
material on which a vapor deposition layer of an inorganic oxide such as silicon oxide
or aluminum oxide is provided; and a barrier film provided with a vapor deposition
layer of a metal such as aluminum.
[0031] Further, the outermost layer of the packaging bag is preferably made of a material
that is strong and hard to tear, and a paper base material is suitable.
[0032] Examples of such paper base material may include kraft paper.
[0033] Therefore, it is preferable that the outermost layer of the packaging bag used in
the first embodiment of the present invention is a paper base material and has a gas
barrier layer in the inner layer. Such a gas barrier layer may be used as a separate
bag as an inner bag, or may be attached by pasting processing (e.g., lamination processing)
to the outermost paper base material. It is more preferable to use the gas barrier
layer as the inner bag from the viewpoint of convenience of handling.
[0034] In addition, the packaging bag used in the first embodiment of the present invention
preferably has ultraviolet impermeability or light shielding properties from the viewpoint
of maintaining the quality of the cellulosic polymer to be filled.
FILLING OF CELLULOSIC POLYMER
[0035] The method for filling the packaging bag with the cellulosic polymer is not particularly
limited, and the packaging bag may be filled in such a manner that the cellulosic
polymer is appropriately filled. It should be noted that an excessive filling of the
cellulosic polymer will make it difficult for adjustment of the condition (3) described
later concerning the first embodiment or adjustment of the oxygen concentration; therefore,
the filling amount of the cellulosic polymer is preferably 99% or less, more preferably
95% or less, and still more preferably 90% or less of the inner volume of the packaging
bag.
[0036] In a case where the packaging bag is a packaging bag having an outer bag (or outer
layer) of a paper base material in the outermost layer described above and an inner
bag (or inner layer) of a gas barrier layer, the inner bag may be filled with a cellulosic
polymer before being packed in the outer bag, or the inner bag may be packed in the
outer bag before being filled with a cellulosic polymer.
ADJUSTMENT OF OXYGEN CONCENTRATION IN PACKAGING BAG
[0037] Although the adjustment of the oxygen concentration in the packaging bag is not particularly
limited, the adjustment is preferably performed after filling the cellulosic polymer,
and examples of the adjustment may include methods of, after filling the cellulosic
polymer, 1) vacuuming the inside of the packaging bag, 2) conducting nitrogen substitution
in the packaging bag, 3) conducting nitrogen substitution after vacuuming the inside
of the packaging bag, and 4) enclosing an oxygen absorbent in the packaging bag. Among
these methods, the method of conducting nitrogen substitution after vacuuming the
inside of the packaging bag is more preferable in the first embodiment of the present
invention because this method can suppress aggregation of the cellulosic polymer.
[0038] In the packaging method according to the first embodiment of the present invention,
it is important that the packaging bag is sealed with the adjustment of the oxygen
concentration to be more than 0.8%. If the oxygen concentration is more than 0.8%,
the cellulosic polymer tends to deteriorate, and there is a concern that the viscosity
reduction occurs when the cellulosic polymer is converted into an aqueous solution.
The oxygen concentration is preferably 0.75% or less, more preferably 0.7% or less,
and still more preferably 0.6% or less. Although the lower limit of the oxygen concentration
is not limited, it is preferably 0.1% or more, more preferably 0.2% or more, and still
more preferably 0.3% or more from the viewpoint of workability and internal pressure
adjustment at the time of nitrogen substitution.
[0039] The internal pressure in the packaging bag is preferably 85 kPa or less, and in particular,
the internal pressure in the gas barrier layer is preferably 85 kPa or less. If the
internal pressure is more than 85 kPa, the expansion of the packaging bag with respect
to the filling material becomes large, and thus it becomes difficult to stack the
packaging bags in a stacked state and there arises a problem in transportation and
others. The internal pressure of such a packaging bag is more preferably 80 kPa or
less.
[0040] Although the method of adjusting the internal pressure in the packaging bag is not
particularly limited, in the case of, e.g., a method of conducting nitrogen substitution
after vacuuming the inside of the packaging bag, the internal pressure in the packaging
bag can be appropriately adjusted by appropriately adjusting the nitrogen injection
amount and the internal pressure indication value from the original pressure when
injecting nitrogen after the vacuum treatment.
SHAPE OF SEALED PACKAGING BAG
[0041] In the first embodiment of the present invention, when the packaging bag filled with
the cellulosic polymer, adjusted in oxygen concentration and sealed is placed on a
horizontal placement plane (also referred to as a horizontal plane) so that the longest
long side L thereof is horizontal, it is important that the depth D of the packaging
bag from the horizontal plane and the long side L satisfies the relational expression
of 6.1 ≤ L/D ≤ 10.
[0042] FIG. 1 shows a packaging bag filled with a cellulosic polymer, which is placed on
a horizontal plane so that the long side L is horizontal. In the present invention,
it is important that the packaging bag filled with the cellulosic polymer is placed
horizontally, and then the filling region is uniformly filled along the horizontal
plane before measuring the long side L and the depth D.
[0043] Such a long side L does not include the sealing opening of the packaging bag and
represents the length of only the filling area of the packaging bag. The long side
L is preferably 700 mm or more and 1,100 mm or less, more preferably 700 mm or more
and 1,000 mm or less, and still more preferably 700 mm or more and 900 mm or less.
[0044] The short side W perpendicular to the long side L of the packaging bag filled with
the cellulosic polymer is preferably 400 mm or more and less than 700 mm, more preferably
450 mm or more and 650 mm or less, still more preferably 450 mm or more and 600 mm
or less.
[0045] The depth D of the packaging bag filled with the cellulosic polymer is preferably
less than 130 mm, more preferably 125 mm or less, and still more preferably 120 mm
or less.
[0046] In the packaging method of the cellulosic polymer according to the first embodiment
of the present invention, satisfying the above relational expression will appropriately
balance the packaging bags filled with the cellulosic polymer in stacking, thereby
facilitating stacking. The long side L, the depth D, and the short side W of the packaging
bag satisfying the above-mentioned ranges can facilitate filling of the cellulosic
polymer and stacking of the packaging bags.
[0047] Further, it is important in the present invention in order to suppress the lack of
balance in the stacked state due to vibration or others when the packaging bags are
stacked and transported.
[0048] In the first embodiment of the present invention, when the packaging bags are stacked,
it is preferable that the packaging bags are stacked in two layers or more and ten
layers or less, and more preferably in two layers or more and eight layers or less.
The stacked state within the above range will appropriately balance the stacked state
of the packaging bags.
2. SECOND EMBODIMENT OF THE PRESENT INVENTION
[0049] As another embodiment of the present invention, there is provided a method for packaging
a cellulosic polymer comprising filling a packaging bag having a gas barrier property
with a cellulosic polymer, the packaging bag having an outermost layer with a surface
satisfying a range of a static friction coefficient of 0.2 to 0.5 and a dynamic friction
coefficient of 0.15 to 0.35 (hereinafter also referred to as the second embodiment).
[0050] First, a packaging bag as one characteristic part in the second embodiment will be
described.
PACKAGING BAG
[0051] In the second embodiment of the present invention, any packaging bag can be used
without any particular restriction as long as the packaging bag has a gas barrier
property. In the present invention, "having a gas barrier property" means having a
function of suppressing permeation of oxygen, moisture, and the like. Such a packaging
bag is preferably formed by using: an aluminum having a high gas barrier property;
a transparent barrier film comprising polyacrylonitrile, polyvinyl alcohol, a nylon
film having a coating film of a polyvinylidene chloride resin, an ethylene-vinyl alcohol
copolymer, an olefin-based polymer, an olefin-polycarboxylic acid copolymer, or a
plastic base material on which a vapor deposition layer of an inorganic oxide such
as silicon oxide or aluminum oxide is provided; and a barrier film provided with a
vapor deposition layer of a metal such as aluminum.
[0052] Further, the outermost layer of the packaging bag is preferably made of a material
that is strong and hard to tear, and a paper base material is suitable. Examples of
such paper base material may include kraft paper.
[0053] Therefore, it is preferable that the outermost layer of the packaging bag used in
the second embodiment of the present invention is a paper base material and has a
gas barrier layer in the inner layer. Such a gas barrier layer may be used as a separate
bag as an inner bag, or may be attached by pasting processing (for eample, lamination
processing) to the outermost paper base material. It is more preferable to use the
gas barrier layer as the inner bag from the viewpoint of convenience of handling.
[0054] It is important that the outermost surface of such a packaging bag have a static
friction coefficient in the range of 0.2 to 0.5, preferably in the range of 0.2 to
0.45, and more preferably in the range of 0.2 to 0.4. By setting the static friction
coefficient of the outermost layer surface within this range, even when the packaging
bags are filled with the cellulosic polymer and stacked each other on a pallet or
the like for transportation, the packaging bags are unlikely to lose balance and fall,
and also the frictional force is not too strong, thus easily adjusting the stacked
state by moving by sliding the packaging bags with rubbing during stacking.
[0055] Further, it is important that the outermost surface of the packaging bag have a dynamic
friction coefficient in the range of 0.15 to 0.35, preferably in the range of 0.2
to 0.35, and more preferably in the range of 0.22 to 0.32. This range is appropriate
because, by setting the dynamic friction coefficient of the outermost layer surface
within this range, even when the packaging bags are filled with the cellulosic polymer
and stacked each other on a pallet or the like for transportation, each of the stacked
packaging bags can be easily moved by sliding with rubbing and also they are unlikely
to lose balance and fall. It should be noted that the static friction coefficient
and the dynamic friction coefficient of the outermost surface of the packaging bag
can be measured in accordance with JIS P8147.
[0056] Further, the outermost layer of the packaging bag has a smoothness by the Oken method,
preferably in the range of 2 to 10 seconds, more preferably in the range of 3 to 9
seconds, and still more preferably in the range of 4 to 8 seconds. The smoothness
of the surface of the outermost layer in this range allows the unevenness of the surface
of the outermost layer to provide a suitable balance, wherein the packaging bags are
filled with cellulosic polymers and stacked each other on a pallet or the like for
transportation, to prevent them from falling or move them by sliding with rubbing.
The smoothness by Oken method can be measured in accordance with JIS P8155.
[0057] In the second embodiment of the present invention, the outermost layer of the packaging
bag has a basis weight of preferably in the range of 50 to 100 g/m
2, more preferably in the range of 60 to 100 g/m
2, and still more preferably in the range of 65 to 95 g/m
2. Wherein the outermost layer base material of the packaging bag satisfys the above
range, it is easier to achieve the optimal balance as the aforementioned outermost
layer, while maintaining strength, even when filled with cellulosic polymers. The
basis weight can be measured in accordance with JIS P8124.
[0058] In addition, the packaging bag used in the first embodiment of the present invention
preferably has ultraviolet impermeability or light shielding properties from the viewpoint
of maintaining the quality of the cellulosic polymer to be filled.
[0059] Other technical matters related to the second embodiment are the same as those of
the first embodiment. In other words, the matters described in the description of
the first embodiment such as: the definition of a cellulosic polymer; method of oxidation;
etherification; carboxymethylated cellulose; cellulose; natural cellulose; degree
of carboxymethyl substitution per anhydrous glucose unit of carboxymethylated cellulose;
anhydrous glucose unit; method of measuring degree of carboxymethyl substitution;
shapes of cellulosic polymers (pulp, powder, microfibril, and nanofiber, and others);
dry solid content when filled in a packaging bag; and the state regarding the number
of stacked layers of the packaging bags may be employed in the second embodiment as
in the first embodiment.
3. COMBINATION OF FIRST EMBODIMENT AND SECOND EMBODIMENT
[0060] As another embodiment of the present invention, the first embodiment and the second
embodiment described above may be combined. Such a modification may be, for example,
the following embodiment.
EXAMPLE OF COMBINATION OF FIRST EMBODIMENT AND SECOND EMBODIMENT
[0061] A method for packaging a cellulosic polymer comprising: filling a packaging bag having
a gas barrier property with a cellulosic polymer; and sealing the packaging bag, wherein
the method satisfies the following conditions (1) to (4):
- (1) the packaging bag having a gas barrier property is filled with a cellulosic polymer;
- (2) an oxygen concentration in the packaging bag is adjusted to 0.8% or less and the
packaging bag is sealed;
- (3) when the packaging bag filled with the cellulosic polymer is placed such that
the longest long side L is horizontal, the depth D of the packaging bag from the horizontal
plane and the long side L satisfy a relational expression of 6.1 ≤ L/D ≤ 10; and
- (4) the packaging bag has an outermost layer with a surface satisfying a range of
a static friction coefficient of 0.2 to 0.5 and a dynamic friction coefficient of
0.15 to 0.35.
[0062] Specific technical matters and preferred examples described in the first embodiment
or the second embodiment are similarly applicable to the combination of the first
and second embodiments.
4. THIRD EMBODIMENT OF THE PRESENT INVENTION
[0063] As described above, the present invention may include some aspects, such as a method
for packaging and a method for transporting, and the present invention further provide
a cellulosic polymer package utilizing such a packaging method. As an embodiment of
the package, for example, the following cellulosic polymer package may be provided
by the packaging method described in the first embodiment.
[0064] A cellulosic polymer package comprising a sealed packaging bag and a cellulosic polymer
filled in the packaging bag under the following conditions (1) to (3):
- (1): the packaging bag having a gas barrier property is filled with a cellulosic polymer;
- (2): the oxygen concentration in the packaging bag is adjusted to 0.8% or less and
the packaging bag is sealed; and
- (3): when a packaging bag filled with a cellulosic polymer is placed such that the
longest long side L is horizontal, the depth D of the packaging bag from the horizontal
placement plane (horizontal plane) and the long side L satisfy the relational expression
of 6.1 ≤ L/D ≤ 10.
[0065] As another embodiment of the package, for example, a cellulosic polymer package as
described below is provided by the packaging method described in the second embodiment.
[0066] A cellulosic polymer package comprising a sealed packaging bag having a gas barrier
property and a cellulosic polymer filled in the packaging bag,
wherein the packaging bag has an outermost layer with a surface satisfying a range
of a static friction coefficient of 0.2 to 0.5 and a dynamic friction coefficient
of 0.15 to 0.35.
[0067] More specific technical matters and preferred examples described in the first embodiment
or the second embodiment are applicable in the same fashion to the third embodiment.
Further, a cellulosic polymer package may be prepared by combining the technical matters
described in the first embodiment and the second embodiment.
Examples
FIRST EXAMPLE GROUP
EXAMPLE 1-1
[0068] Carboxymethyl cellulose (manufactured by Nippon Paper, product name: MAC500LC) was
filled in an unfilled (empty) packaging bag having a length of 850 mm and a width
of 565 mm, the outermost layer of which was a kraft paper base material, and the interior
of which was a film base material.
[0069] After filling and vacuum degassing, nitrogen gas was injected, the oxygen concentration
in the package was adjusted to 0.50%, the internal pressure indication value was adjusted
to 70 kPa, and the sealing opening was sealed.
[0070] The obtained packaging bag was placed on a horizontal plane so that the content of
the packaging bag was uniform in the filling area, and then the packaging bag was
measured; the longest long side L was 760 mm, the depth D from the horizontal plane
was 110 mm, and the short side W perpendicular to the long side L was 520 mm.
EXAMPLE 1-2
[0071] A packaging bag was obtained in the same manner as in Example 1-1 except that carboxymethyl
cellulose (manufactured by Nippon Paper, product name: MAC350HC) was used.
EXAMPLE 1-3
[0072] A packaging bag was obtained in the same manner as in Example 1 except that carboxymethyl
cellulose (manufactured by Nippon Paper, product name: MAC800LC) was used.
COMPARATIVE EXAMPLE 1-1
[0073] A packaging bag was obtained in the same manner as in Example 1 except that the oxygen
concentration in the package was set to 0.3% and the internal pressure indication
value was set to 90 kPa. The obtained packaging bag was placed on a horizontal plane
so that the content of the packaging bag was uniform in the filling area, and the
packaging bag was measured; the longest long side L was 760 mm, the depth D from the
horizontal plane was 130 mm, and the short side W perpendicular to the long side L
was 520 mm.
[Table 1]
[0074]
Table 1
|
Packaging Bag |
Filled Substance |
Packaging Bag After Filled |
Outermost Layer |
Inner Layer |
Oxygen Concentration (%) |
Internal Pressure (KPa) |
L (mm) |
D (mm) |
W (mm) |
L/D |
EXAMPLE 1-1 |
Kraft Paper |
Film |
MAC500LC |
0.5 |
70 |
760 |
110 |
520 |
6.9 |
EXAMPLE 1-2 |
Kraft Paper |
Film |
MAC350HC |
0.5 |
70 |
760 |
110 |
520 |
6.9 |
EXAMPLE 1-3 |
Kraft Paper |
Film |
MAC800LC |
0.5 |
70 |
760 |
110 |
520 |
6.9 |
COMPARATIVE EXAMPLE 1-1 |
Kraft Paper |
Film |
MAC500LC |
0.3 |
90 |
760 |
130 |
520 |
5.8 |
[0075] The viscosities of 1% aqueous solution of Examples 1-1 to 1-3 and Comparative Example
1-1 were measured immediately after filling with carboxymethyl cellulose and after
storage in a container at 50°C for 1, 3, and 6 months. The adjustment of the aqueous
solution and the measurement of the viscosity were performed by the method described
later.
[0076] In addition, the obtained packaging bags were stacked on a pallet in 4 rows and 6
layers, and the stacked state thereof was visually checked.
ADJUSTMENT OF AQUEOUS SOLUTION
[0077] About 10 g of a sample is weighed with a balance scale. The sample is gradually charged
into a beaker containing 880 ml of pure water, while stirring using a dissolving stirrer,
and stirred for 3 hours. The purified water calculated from the water content is corrected
so as to achieve a concentration of 1%.
VISCOSITY MEASUREMENT
[0078] After stirring for 3 hours (to confirm complete dissolution), the temperature of
the solution is adjusted to 25 ± 0.2°C. The viscosity is measured by using a type
B viscometer. The measured value is read on the scale 3 minutes after the start of
the rotor.
VISCOSITY CHANGE RATE
[0079] The rate of change in the viscosity of 1% aqueous solution of the cellulosic polymer
stored (1 month, 3 months, 6 months) at 50°C in the container after packaging (Viscosity
2) with respect to the viscosity of 1% aqueous solution of the cellulosic polymer
for 0 elapsed days (before packaging) (Viscosity 1) is calculated by the following
formula (1).

[Table 2]
[0080]
Table 2
|
Viscosity Change Rate |
Stacking State |
Elapsed Month(s) |
0 |
1 month |
3 months |
6 months |
EXAMPLE 1-1 |
0 |
-1 |
-1 |
-3 |
Each packaging bag is tightly stacked and excels in balance. |
EXAMPLE 1-2 |
0 |
-3 |
-3 |
-4 |
Each packaging bag is tightly stacked and excels in balance. |
EXAMPLE 1-3 |
0 |
-4 |
-1 |
-3 |
Each packaging bag is tightly stacked and excels in balance. |
COMPARATIVE EXAMPLE 1-1 |
0 |
-1 |
-1 |
-2 |
Each packaging bag is expanded, cannot be tightly stacked, and is unbalanced. |
[0081] It can be seen that, in the packaging bags of Examples 1-1 to 1-3, the filled carboxymethyl
cellulose can maintain a high viscosity after storage. Further, since the inner pressure
of the packaging bag is well balanced with respect to the strength of the packaging
bag and does not cause expansion, the packaging bag is also well balanced during stacking.
[0082] On the contrary, although having an excellent effect of maintaining the viscosity
of carboxymethyl cellulose because the oxygen concentration is kept low, the packaging
bag of Comparative Example 1-1 is not suitable for transportation because the inner
pressure is high and the packaging bag is expanded and unbalanced in the stacked state.
SECOND EXAMPLE GROUP
EXAMPLE 2-1
[0083] Carboxymethyl cellulose (manufactured by Nippon Paper, product name: MAC500LC) was
filled in a packaging bag having a kraft paper base material (surface static friction
coefficient of 0.32, dynamic friction coefficient of 0.28, Oken type smoothness of
5 seconds, and basis weight of 85 g/m
2) as the outermost layer and a film base material as an inner layer.
[0084] After filling and vacuum degassing, nitrogen gas was injected, the oxygen concentration
in the package was adjusted to 0.50% and the internal pressure indication value was
adjusted to 70 kPa, the sealing opening was sealed, thus obtaining a packaging bag
2-1 filled with carboxymethyl cellulose.
EXAMPLE 2-2
[0085] A packaging bag 2-2 filled with carboxymethyl cellulose was obtained in the same
manner as in Example 1 except that the outermost layer was changed to a kraft paper
base material (surface static friction coefficient of 0.30, dynamic friction coefficient
of 0.28, Oken type smoothness of 5 seconds, and basis weight of 76 g/m
2) .
COMPARATIVE EXAMPLE 2-1
[0086] A packaging bag 3 filled with carboxymethyl cellulose was obtained in the same manner
as in Example 1 except thatthe outermost layer is changed to a film base material
(surface static friction coefficient of 0.12, dynamic friction coefficient of 0.1,
Oken type smoothness being not measurable, and basis weight of 109 g/m
2), not using the kraft paper base material.
[Table 3]
[0087]
Table 3
|
Packaging Bag |
Filled Substance |
Outermost Layer |
Inner Layer |
EXAMPLE 2-1 |
Kraft Paper |
Film |
MAC500LC |
EXAMPLE 2-2 |
Kraft Paper |
Film |
MAC500LC |
COMPARATIVE EXAMPLE 2-1 |
Film |
- |
MAC500LC |
[0088] The viscosities of 1% aqueous solution of Examples 2-1 and 2-2 were measured immediately
after filling with carboxymethyl cellulose and after storage in a container at 50°C
for 1, 3, and 6 months. The adjustment of the aqueous solution, the measurement of
the viscosity, and the calculation of the viscosity change rate were performed by
the same method as that shown for the first example group.
[0089] In addition, the packaging bags of Examples 2-1 and 2-2 and Comparative Example 2-1
were stacked on a pallet in 4 rows and 6 layers, and the ease of stacking was confirmed
and the stacked state was visually checked.
Table 4
|
Viscosity Change Rate |
Stacked State |
Elapsed Month(s) |
0 |
1 month |
3 months |
6 months |
EXAMPLE 2-1 |
0 |
-1 |
-1 |
-3 |
Each packaging bag could be easily adjusted to be stacked closely by sliding with
rubbing. The packaging bags also have excellent balance when stacked. |
EXAMPLE 2-2 |
0 |
-1 |
-1 |
-3 |
Each packaging bag could be easily adjusted to be stacked closely by sliding with
rubbing. The packaging bags also have excellent balance when stacked. |
COMPARATIVE EXAMPLE 2-1 |
- |
- |
- |
- |
Each packaging bag was out of balance when it was slid with rubbing, and the packaging
bags could not maintain a closely stacked state. |
1. A method for packaging a cellulosic polymer, comprising: filling a packaging bag having
a gas barrier property with the cellulosic polymer; and sealing the packaging bag.
2. The method for packaging a cellulosic polymer according to claim 1, wherein the method
satisfies the following conditions (1) to (3):
(1) the packaging bag having the gas barrier property is filled with a cellulosic
polymer;
(2) an oxygen concentration in the packaging bag is adjusted to 0.8% or less and the
packaging bag is sealed; and
(3) when the packaging bag filled with the cellulosic polymer is placed such that
the longest long side L is horizontal, the depth D of the packaging bag from the horizontal
plane and the long side L satisfy a relational expression of 6.1 ≤ LID ≤ 10.
3. The method for packaging a cellulosic polymer according to claim 1 or 2, wherein the
longest long side L of the packaging bag filled with the cellulosic polymer has a
length of 700 mm or more and 1,100 mm or less.
4. The method for packaging a cellulosic polymer according to any one of claims 1 to
3, wherein a short side W of the packaging bag perpendicular to the long side L of
the packaging bag filled with the cellulosic polymer has a length of 400 mm or more
and less than 700 mm.
5. The method for packaging a cellulosic polymer according to any one of claims 1 to
4, wherein the depth D of the packaging bag filled with the cellulosic polymer is
less than 130 mm.
6. The method for packaging a cellulosic polymer according to any one of claims 1 to
5, comprising: filling the packaging bag having a gas barrier property with a cellulosic
polymer, the packaging bag having an outermost layer with a surface satisfying a range
of a static friction coefficient of 0.2 to 0.5 and a dynamic friction coefficient
of 0.15 to 0.35.
7. The method for packaging a cellulosic polymer according to claim 6, wherein the outermost
layer of the packaging bag satisfies a range of a smoothness of 2 to 10 seconds.
8. The method for packaging a cellulosic polymer according to claim 6 or 7, wherein the
outermost layer of the packaging bag is a paper base material.
9. The method for packaging a cellulosic polymer according to any one of claims 6 to
8, wherein the outermost layer of the packaging bag satisfies a range of a basis weight
of 50 to 100 g/m2.
10. The method for packaging a cellulosic polymer according to any one of claims 1 to
9, wherein the cellulosic polymer is carboxymethyl cellulose.
11. The method for packaging a cellulosic polymer according to any one of claims 1 to
10, wherein after the inside of the packaging bag is vacuum-treated, nitrogen substitution
is conducted to adjust the oxygen concentration to 0.8% or less.
12. The method for packaging a cellulosic polymer according to any one of claims 1 to
11, wherein the packaging bag has an internal pressure of 85 kPa or less.
13. A method for transporting a cellulosic polymer, comprising: stacking packaging bags
obtained by the method for packaging a cellulosic polymer according to any one of
claims 1 to 12 and transporting the packaging bags to a destination.
14. The method for transporting a cellulosic polymer according to claim 13, wherein the
packaging bags are stacked in two layers or more and ten layers or less.
15. A cellulosic polymer package, comprising: a sealed packaging bag and a cellulosic
polymer filled in the packaging bag under the following conditions (1) to (3):
(1) the packaging bag having a gas barrier property is filled with the cellulosic
polymer;
(2) an oxygen concentration in the packaging bag is adjusted to 0.8% or less and the
packing bag is sealed; and
(3) when the packaging bag filled with the cellulosic polymer is placed such that
the longest long side L is horizontal, the depth D of the packaging bag from the horizontal
plane and the long side L satisfy a relational expression of 6.1 ≤ LID ≤ 10.
16. The cellulosic polymer package according to claim 15, wherein the packaging bag has
an outermost layer with a surface satisfying a range of a static friction coefficient
of 0.2 to 0.5 and a dynamic friction coefficient of 0.15 to 0.35.
17. The cellulosic polymer package according to claim 15 or 16, wherein the cellulosic
polymer is carboxymethyl cellulose.
18. The cellulosic polymer package according to any one of claims 15 to 17, wherein the
packaging bag has an oxygen concentration of more than 0.3% and 0.8% or less.
19. The cellulosic polymer package according to any one of claims 15 to 18, wherein the
packaging bag has an internal pressure of 85 kPa or less.
20. The cellulosic polymer package according to any one of claims 15 to 19, wherein the
packaging bag has a two-layer structure or a three or more-layer structure, the outermost
layer of the packaging bag is a paper base material, and at least one of the inner
bag layers inside the outermost layer is a gas barrier layer.