U.S. patent application number 15/319446 was filed with the patent office on 2017-11-09 for structure forming a liquid film on the surface thereof and coating solution for forming the liquid film.
This patent application is currently assigned to TOYO SEIKAN CO., LTD.. The applicant listed for this patent is TOYO SEIKAN CO., LTD.. Invention is credited to Tomoyuki MIYAZAKI, Keisuke NYUU, Yoshiaki OKADA.
Application Number | 20170321071 15/319446 |
Document ID | / |
Family ID | 54935248 |
Filed Date | 2017-11-09 |
United States Patent
Application |
20170321071 |
Kind Code |
A1 |
OKADA; Yoshiaki ; et
al. |
November 9, 2017 |
STRUCTURE FORMING A LIQUID FILM ON THE SURFACE THEREOF AND COATING
SOLUTION FOR FORMING THE LIQUID FILM
Abstract
A structure forming, on the surface thereof, a liquid film for
improving sliding property to a fluid substance, the liquid film
containing solid particles of particle size of not more than 300
.mu.m that are dispersed therein. The structure exhibits further
improved sliding property to the fluid substances due to the liquid
film formed on the surface thereof, and can be favorably used as
packing materials such as containers and lids.
Inventors: |
OKADA; Yoshiaki;
(Yokohama-shi, Kanagawa, JP) ; MIYAZAKI; Tomoyuki;
(Yokohama-shi, Kanagawa, JP) ; NYUU; Keisuke;
(Yokohama-shi, Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYO SEIKAN CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
TOYO SEIKAN CO., LTD.
Tokyo
JP
|
Family ID: |
54935248 |
Appl. No.: |
15/319446 |
Filed: |
April 20, 2015 |
PCT Filed: |
April 20, 2015 |
PCT NO: |
PCT/JP2015/062018 |
371 Date: |
December 16, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10N 2050/02 20130101;
C09D 7/69 20180101; B65D 2231/00 20130101; C10M 165/00 20130101;
B32B 5/16 20130101; B32B 2439/00 20130101; C09D 191/00 20130101;
C10M 159/06 20130101; C10M 2205/18 20130101; B32B 33/00 20130101;
C09D 7/40 20180101; B65D 1/00 20130101; B65D 23/02 20130101; C10M
2207/401 20130101; C09D 5/00 20130101; C09D 201/00 20130101; B65D
2231/005 20130101; B32B 17/06 20130101; C09D 7/65 20180101; B65D
1/0207 20130101; B65D 1/0223 20130101; C10M 2209/12 20130101; B32B
2264/00 20130101; C10N 2020/06 20130101; B32B 27/06 20130101; B05D
1/02 20130101 |
International
Class: |
C09D 7/12 20060101
C09D007/12; B32B 5/16 20060101 B32B005/16; B32B 33/00 20060101
B32B033/00; C10M 109/00 20060101 C10M109/00; C09D 201/00 20060101
C09D201/00; B05D 1/02 20060101 B05D001/02; B65D 1/02 20060101
B65D001/02; B32B 27/06 20060101 B32B027/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2014 |
JP |
2014-126877 |
Claims
1. A structure forming, on a surface thereof, a liquid film for
improving sliding property to a fluid substance, the liquid film
containing solid particles of particle size of not more than 300
.mu.m that are dispersed therein.
2. The structure according to claim 1, wherein a liquid forming the
liquid film acquires angle of contact (20.degree. C.) of not more
than 45.degree. relative to the surface that supports the liquid
film and has viscosity (25.degree. C.) of not more than 100
mPas.
3. The structure according to claim 1, wherein the solid particles
are organic particles.
4. The structure according to claim 1, wherein the solid particles
are dispersed in an amount of 0.01 to 10 parts by mass per 100
parts by mass of a liquid that forms the liquid film.
5. The structure according to claim 1, wherein the liquid film is
formed in an amount of 1.0 to 6.2 mg/cm.sup.2 on the surface of the
structure.
6. The structure according to claim 1, wherein the surface of the
structure is formed of a synthetic resin.
7. The structure according to claim 1, wherein the surface of the
structure is formed of glass.
8. The structure according to claim 1, wherein the structure is
used as a packing material.
9. The structure according to claim 8, wherein the packing material
is used for containing a liquid content that has viscosity
(25.degree. C.) of not less than 1260 mPas.
10. The structure according to claim 8, wherein the packing
material is a container.
11. A coating solution for forming a liquid film on a surface of a
structure, the coating solution containing, as a dispersion medium,
a liquid for forming the liquid film and, further, containing solid
particles of particle size of 5 .mu.m to 300 .mu.m in an amount of
0.01 to 20 parts by mass per 100 parts by mass of the liquid that
is the dispersion medium.
Description
TECHNICAL FIELD
[0001] This invention relates to a structure having a liquid film
on the surface thereof. More specifically, the invention relates to
a structure that exhibits improved sliding property to the fluid
substance due to the liquid film and to a coating solution for
forming the liquid film.
BACKGROUND ART
[0002] The containers for containing liquid contents must be
capable of favorably discharging the contents irrespective of the
materials forming the containers. Discharging the content is not
almost of a problem when the liquids having low viscosity such as
water and the like are contained. Discharging the content, however,
becomes a serious problem when the content is a highly viscous
substance such as mayonnaise or ketchup irrespective of the plastic
container or the glass container. Namely, the contents of this kind
are not quickly discharged despite the container is tilted.
Besides, the contents tend to stay on the container wall and cannot
be all recovered. Particularly, the content stays in considerable
amounts on the bottom of the container and is not all
recovered.
[0003] In recent years, there have been proposed various kinds of
technical arts for improving sliding properties to viscous
substances by forming a liquid film on the surface of a base
material (e.g., see patent documents 1 and 2).
[0004] According to the above technical arts, the sliding property
can be strikingly improved as compared to the cases of adding an
additive such as lubricant to the synthetic resin that forms the
surface of the base material, and attention has now been paid
thereto.
[0005] Here, even according to means for improving surface
properties by forming the liquid film on the surface of the base
material as described above, it is not still possible to
effectively prevent the content from adhering on the bottom of the
container. Therefore, it has been desired to further improve the
sliding property.
[0006] There has, further, been proposed a container with fine
particles of a hydrophobic oxide adhered on the inner surface
thereof and featuring excellent non-adhering property (patent
document 3).
[0007] However, the sliding property expressed by the above
container is very weaker than that expressed by the container
provided with the liquid film.
[0008] Besides, improving the sliding property to the
above-mentioned fluid substances has been desired not only for the
containers but also for the lid materials and for the members such
as pipes for flowing viscous fluid substances.
PRIOR ART DOCUMENTS
Patent Documents
[0009] Patent document 1: WO2012/100099 [0010] Patent document 2:
WO2013/022467
OUTLINE OF THE INVENTION
Problems that the Invention is to Solve
[0011] It is, therefore, an object of the present invention to
provide a structure having a liquid film on the surface thereof and
exhibiting, due to the liquid film, further improved sliding
property to fluid substances and, specifically, to viscous fluid
substances.
[0012] Another object of the present invention is to provide a
structure that exhibits further improved sliding property to the
content and that can be favorably used as packing materials such as
containers and lids.
[0013] A further object of the present invention is to provide a
container that exhibits sliding property to the content, the
sliding property being improved to such an extent that a viscous
content is effectively prevented from adhering or remaining on the
bottom portion.
Means for Solving the Problems
[0014] According to the present invention, there is provided a
structure forming, on a surface thereof, a liquid film for
improving sliding property to a fluid substance, the liquid film
containing solid particles of particle size of not more than 300
.mu.m that are dispersed therein.
[0015] In the structure of the present invention, it is desired
that: [0016] (1) A liquid forming the liquid film acquires angle of
contact (20.degree. C.) of not more than 45.degree. relative to the
surface (underlying surface) that supports the liquid film and has
viscosity (25.degree. C.) of not more than 100 mPas; [0017] (2) The
solid particles are organic particles; [0018] (3) The solid
particles are dispersed in an amount of 0.01 to 10 parts by mass
per 100 parts by mass of a liquid that forms the liquid film;
[0019] (4) The liquid film is formed in an amount of 1.0 to 6.2
mg/cm.sup.2 on the surface of the structure; [0020] (5) The surface
of the structure is formed of a synthetic resin; [0021] (6) The
surface of the structure is formed of glass; [0022] (7) The
structure is used as a packing material; [0023] (8) The packing
material is used for containing a liquid content that has viscosity
(25.degree. C.) of not less than 1260 mPas; and [0024] (9) The
packing material is a container.
[0025] According to the present invention, further, there is
provided a coating solution for forming a liquid film on the
surface of a structure, the coating solution containing, as a
dispersion medium, a liquid for forming the liquid film and,
further, containing solid particles of particle size of 5 .mu.m to
300 .mu.m in an amount of 0.01 to 20 parts by mass per 100 parts by
mass of the liquid that is the dispersion medium.
Effects of the Invention
[0026] Referring to FIG. 1, the structure of the present invention
has a surface structure in which a liquid film 3 is formed by using
a liquid 2 on a surface 1 that comes in contact with a fluid
substance, the liquid film 3 containing, dispersed therein, fine
solid particles 5 of particle size of not more than 300 .mu.m.
Therefore, the fluid substance flowing on the surface 1 comes in
contact with the liquid 2 that is present on the surfaces of the
fine solid particles 5; i.e., greatly improved sliding property is
exhibited to the fluid substance.
[0027] It has been known already that the sliding property to the
content improves if a film of a liquid is formed on the surface of
a packing material such as a container. If a viscous content is to
be discharged from the packing material (e.g., container) having
the above liquid film formed on the inner surface thereof, then the
content is discharged from the packing material in liquid-liquid
contact. That is, the content flows down along the inner surface of
the packing material not in solid-liquid contact but in
liquid-liquid contact. Therefore, if an oily liquid is used that is
immiscible with the content, then the sliding property can be
improved to an aqueous substance that contains water. Further, if
an aqueous liquid is used that is immiscible with the content, then
the sliding property can be improved to an oily substance.
[0028] Here, with the structure of the present invention in which
the fine solid particles 5 are dispersed in the liquid film 3, the
sliding property is further improved to the fluid substance (e.g.,
to the content in the container) owing to the liquid film 3.
[0029] For example, as demonstrated in Experimental Examples
appearing later, the mayonnaise-like food slides down more quickly
when the fine solid particles (rice wax) are dispersed in the film
of a liquid paraffin formed on the surface of a polypropylene sheet
(for detailed conditions, refer to Examples) than when the film of
the liquid paraffin (no solid particle has been dispersed) is
formed on the surface of the polypropylene sheet.
[0030] As described above, the sliding property to the fluid
substance further improves when the fine solid particles 5 are
dispersed in the liquid film 3 because of the reasons which the
present inventors presume as described below.
[0031] Namely, if the fluid substance (e.g., the content in the
packing material such as a container) falls down in contact with
the liquid film 3, the solid particles 5 serve as rollers and fall
down rolling together with the fluid substance. It is, therefore,
considered that the sliding property is further improved than when
the liquid film 3 is simply formed. In fact, when the solid
particles 5 are adhered on the surface 1 of the structure instead
of being dispersed in the liquid film 3, the sliding property to
the fluid substance changes little as compared to when the liquid
film 3 is simply formed as also demonstrated in Experimental
Examples appearing later. This is because, in this case, the solid
particles are fixed on the surface 1 and do not serve as
rollers.
[0032] If used, specifically, as a container such as a bottle, the
structure of the present invention works to greatly suppress the
content from adhering and remaining on the bottom portion in
addition to exhibiting improved sliding property to the
content.
[0033] For instance, in Experimental Examples appearing later, the
bottles filled with a mayonnaise-like food (viscosity: 1260
mPas@25.degree. C.) as the content have been evaluated for the
adhesion of food on the bottom portion. In the bottles in which the
fine solid particles are dispersed in the liquid film formed on the
inner surfaces according to the present invention, it is learned
from the results of the tests that adhesion of the mayonnaise-like
food has been greatly suppressed.
[0034] As for the reason why the content is effectively suppressed
from adhering or remaining on the bottom portion, the present
inventors consider that even after the content has slipped down,
the solid particles 5 still work to hold the liquid film 3 on the
surface 1 and are still held on the surface 1 (inner surface of the
container). As a result, the inventors consider that the liquid
film 3 held on the surfaces of the solid particles 5 is effectively
held on the bottom portion of the container. That is, in case the
liquid film 3 is simply formed containing no fine solid particle 5
dispersed therein, if the container is inverted or is tilted, the
liquid film 3 (liquid 2) splits away due to its own weight from the
surface 1 (inner surface of the container) of the structure. As a
result, the sliding property to the content greatly decreases on
the bottom portion. In the present invention, however, the liquid
film 3 (liquid 2) in which the solid particles 5 are dispersed is
firmly held on the surface 1 (inner surface of the container) of
the structure, and the sliding property is stably exhibited in the
bottom portion, too.
[0035] Further, if the container which is the most preferred
embodiment of the structure of the present invention is inverted or
tilted to discharge the content out of the container, part of the
liquid film 3 and part of the solid particles 5 fall down and are
discharged together with the content. If the container is returned
back to the erected state, however, the solid particles 5 holding
the liquid film 3 on the surfaces thereof less tend to slip down
than the content. Namely, the solid particles 5 stay on the bottom
portion of the container and work again to exhibit excellent
sliding property when the content is discharged next time.
[0036] Upon selecting a suitable kind of liquid for forming the
liquid film 3 and selecting a suitable kind of fine solid particles
5 that are to be dispersed in the liquid film 3, the structure or
the container of the present invention can be favorably used for
containing viscous contents that could not be smoothly discharged
so far. Specifically, the structure of the present invention can be
most favorably used as a container for containing the contents
having viscosity (25.degree. C.) of not less than 1260 mPas, such
as mayonnaise, ketchup and a variety of kinds of dressings.
[0037] The liquid film 3 can be easily formed on the surface of the
structure (e.g., on the inner surface of a packing material) of the
present invention by applying a coating solution for forming the
liquid film to the surface of the structure by coating method such
as spraying, the coating solution containing, as a dispersion
medium, a liquid for forming the liquid film and, further,
containing solid particles of particle size of 5 .mu.m to 300 .mu.m
in an amount of 0.01 to 20 parts by mass per 100 parts by mass of
the liquid that is the dispersion medium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a model view illustrating the state of a liquid
film formed on the surface of a structure of the present
invention.
[0039] FIG. 2 is a model view illustrating the state of the liquid
film in a case when the solid particles are dispersed too much in
the liquid film (FIG. 2(a)) and in a case when the solid particles
are dispersed too little (FIG. 2(b)).
[0040] FIG. 3 is a view showing a direct blow-formed bottle which
is a preferred embodiment of the structure of the present
invention.
[0041] FIG. 4 is a view illustrating conditions for testing the
sliding property.
MODES FOR CARRYING OUT THE INVENTION
<Surface of the Structure>
[0042] Referring to FIG. 1, no particular limitation is imposed on
the material for forming the surface 1 of the structure of the
present invention if it is capable of holding the liquid film 3 in
which solid particles 5 described later are dispersed and, at the
same time, if it can be formed to meet the mode of the packing
material. Namely, the material may be a synthetic resin, glass or a
metal. That is, the structure of the present invention is favorably
used as a packing material or as a pipe for flowing viscous fluid
substances. Specifically, the packing material may be a synthetic
resin container, a glass container, a metal container, or may be a
lid made of a synthetic resin used for sealing the mouth portion of
a container or may be a pouring fitting made of a synthetic resin
used for pouring the content out of the container.
[0043] When the structure is used as a container, from the
perspective of effectively pouring viscous contents, it is desired
that the present invention is adopted to a container of which the
inner surface is formed of a synthetic resin or glass and,
specifically, of which the inner surface is formed of the synthetic
resin that has heretofore been used for containing viscous
contents. Therefore, the material forming the inner surface 1 of
the packing material is, most desirably, a synthetic resin.
[0044] The synthetic resin desirable as a material for forming the
surface 1 of the structure (hereinafter called underlying resin)
may be any thermoplastic resin or thermosetting resin that can be
formed. Usually, however, a thermoplastic resin is preferred from
such a standpoint that it can be easily formed and that it is
capable of stably holding the liquid film of an oily liquid and the
solid particles that hold the liquid film on the surfaces
thereof.
[0045] As the thermoplastic resin, there can be exemplified the
following resins; i.e.,
[0046] olefin resins such as low-density polyethylene, high-density
polyethylene, polypropylene, poly(l-butene),
poly(4-methyl-1-pentene), and random or block copolymers of
.alpha.-olefins such as ethylene, propylene, 1-butene or
4-methyl-1-pentene, and cyclic olefin copolymers;
[0047] ethylene-vinyl copolymers such as ethylene-vinyl acetate
copolymer, ethylene-vinyl alcohol copolymer and ethylene-vinyl
chloride copolymer;
[0048] styrene resins such as polystyrene, acrylonitrile-styrene
copolymer, ABS and .alpha.-methylstyrene-styrene copolymer;
[0049] vinyl resins such as polyvinyl chloride, polyvinylidene
chloride, vinyl chloride-vinylidene chloride copolymer, poly(methyl
acrylate) and poly(methyl methacrylate);
[0050] polyamide resins such as nylon 6, nylon 6-6, nylon 6-10,
nylon 11 and nylon 12;
[0051] polyester resins such as polyethylene terephthalate (PET),
polybutylene terephthalate, polyethylene naphthalate and
copolymerized polyesters thereof;
[0052] polycarbonate resins;
[0053] polyphenylene oxide resins; and
[0054] biodegradable resins such as polylactic acid and the
like.
[0055] As a matter of course, it is also allowable to use a blend
of the above thermoplastic resins as the underlying resin so far as
it does not impair the formability.
[0056] In the invention, among the above thermoplastic resins, it
is desired to use an olefin resin and a polyester resin that have
been used as materials of containers for containing viscous
contents, and it is most desired to use the olefin resin.
[0057] That is, as compared to the polyester resin such as PET, the
olefin resin has low glass transition temperature (Tg) and shows
high molecular mobility at room temperature. When an oily liquid
film such as of edible oil is formed on the surface, therefore, the
liquid forming the film partly infiltrates into the interior of the
olefin resin which, therefore, stably holds the liquid film and the
solid particles that also hold the liquid film on the surfaces
thereof.
[0058] Besides, the olefin resin is highly flexible and is also
used for direct blow-forming of the containers that can be squeezed
(squeezable bottles). Therefore, the olefin resin is suitably used
from the standpoint of adopting the invention to the containers of
the above-mentioned type.
<Liquid Film>
[0059] As the liquid 2 used for forming the liquid film 3 on the
surface 1 of the structure, a suitable liquid is selected depending
on the object (e.g., content in the packing material) to which the
sliding property is exhibited by the surface 1. The liquid, as a
matter of course, must be a nonvolatile liquid having a small vapor
pressure under atmospheric pressure, such as a high-boiling liquid
having a boiling point of not lower than 200.degree. C. This is
because if the volatile liquid is used, the liquid easily
volatilizes and extinguishes with the passage of time making it
difficult to form the liquid film 3.
[0060] Moreover, the liquid must have a high boiling point as
described above and must, further, be immiscible with the fluid
substance that flows on the surface 1. Further, the liquid must
have high wettability to the surface 1 and must be capable of
forming the liquid film 3 evenly on the surface 1. From these
points of view, therefore, the liquid must acquire angle of contact
(20.degree. C.) of, desirably, not more than 45.degree. relative to
the surface 1 and must have viscosity (25.degree. C.) of not more
than 100 mPas. Namely, the liquid film 3 is formed by using the
liquid 2 that satisfies the above-mentioned properties irrespective
of if the material forming the surface 1 of the structure is a
synthetic resin, glass or a metal.
[0061] Further, as for the liquid 2 that satisfies the
above-mentioned properties, a liquid exhibits a high lubricating
effect if it has a surface tension greatly different from that of
the substance (e.g., content in the container) that is to slip
down, and is suited for the present invention.
[0062] For example, to improve the sliding property to water or a
hydrophilic substance that contains water, it is desired to use an
oily liquid having a surface tension lying in a range of 10 to 40
mN/m and, specifically, 16 to 35 mN/m. Representative examples are
liquid paraffin, synthetic paraffin, fluorine-containing liquid,
fluorine-containing surfactant, silicone oil, fatty acid
triglyceride and various plant oils. As the plant oils, there can
be preferably used soybean oil, rape oil, olive oil, rice oil, corn
oil, safflower oil, sesame oil, palm oil, castor oil, avocado oil,
coconut oil, almond oil, walnut oil, hazel oil, salad oil, and the
like.
[0063] In the invention, further, it is desired that the liquid
film 3 in which the solid particles 5 are dispersed is formed on
the inner surface 1 of the packing material in an amount of 1.0 to
6.2 mg/cm.sup.2. If the amount thereof is too small, the liquid
film 3 loses stability in exhibiting the effect for improving the
sliding property. If the amount thereof is too large, on the other
hand, the amount of the liquid film 3 loses stability and, besides,
the fine solid particles 5 may fail to work as rollers as will be
described later.
<Fine Solid Particles>
[0064] In the invention, the solid particles 5 to be dispersed in
the liquid film 3 do not dissolve in the liquid 2 that forms the
liquid film 3, are present therein in a solid form and do not,
either, dissolve in a fluid substance (e.g., content in the
container) that flows on the structure 1. Here, it is essential
that the solid particles 5 are fine particles having particle size
(median diameter of particles) of not more than 300 .mu.m and,
preferably, not more than 100 .mu.m. If the particle size is too
large, the particles may fail to roll to a sufficient degree and
may fail to exhibit the effect of improving the sliding property to
a sufficient degree. It is, further, desired that the particle size
is not less than 5 .mu.m. from such a viewpoint that the particles
are homogeneously dispersed in the structure 1 without being
aggregated.
[0065] Further, the solid particles 5 remain in a solid form when
the liquid film is being formed and, therefore, should have a
melting point of not lower than 40 degrees.
[0066] There is no specific limitation on the material of the solid
particles 5 which, therefore, may be formed by using any kind of
organic material or inorganic material. From the standpoint of
being held on the surface 1 of the structure and affinity to the
liquid 2 that forms the liquid film 3, however, it is desired that
the solid particles 5 are rather organic particles than inorganic
particles such as metal particles or metal oxide particles.
Desirably, the particles are formed of, for example, olefin wax,
rice wax, carnauba wax, various celluloses and cured organic resin
(e.g., cured product obtained by curing a polyfunctional acrylic
monomer). Specifically, the rice wax and the like are desired from
such a standpoint that they can be used for the contents that are
foods without limitation.
[0067] In the present invention, it is desired that the solid
particles 5 are dispersed in the liquid film 3 in an amount of 0.01
to 10 parts by mass and, specifically, 0.1 to 5 parts by mass per
100 parts by mass of the liquid that forms the liquid film 3 from
such a standpoint that the solid particles roll well to exhibit
rolling property to a sufficient degree and that they are held on
the inner surface 1 of the packing material while holding the
liquid film 3 on the surfaces thereof. For instance, as shown in
the model view of FIG. 2(a), if the amount of the solid particles 5
is too large, the solid particles 5 undergo the aggregation and
fail to improve the sliding property to a sufficient degree.
Further, as shown in the model view of FIG. 2(b), if the amount of
the liquid is too large, the solid particles 5 cannot roll well to
exhibit improved sliding property. Besides, if the packing material
is a container, the solid particles 5 cannot be sufficiently held
on the bottom portion; i.e., the solid particles 5 holding the
liquid film 3 on the surfaces thereof are liable to be
extinguished. If the structure is used as a container, therefore,
the effect becomes insufficient for suppressing the adhesion and
stay of the content on the bottom portion.
[0068] In the invention, further, the liquid film 3 in which the
solid particles 5 are dispersed can be easily formed on the surface
1 of the structure by preparing a coating solution by mixing a
predetermined amount of solid particles 5 having a predetermined
particle size in the liquid 2 that forms the liquid film 3 with
stirring, and applying the coating solution to the surface 1 of the
structure such as a container by spraying, dipping, and the
like.
<Form of the Structure>
[0069] There is no limitation on the form of the structure of the
invention having the above-mentioned surface structure provided the
liquid film 3 in which the solid particles 5 are dispersed is
formed on the surface that comes in contact with the fluid
substance. Namely, the structure of the invention can assume a
variety of forms depending on the use, such as pipes, containers
and lids.
[0070] Specifically, the structure of the present invention is
favorably adapted to the packing materials and is favorably used in
the form of, for example, a synthetic resin container, a glass
container, a metal container, as well as a lid and a pouring
fitting (spout).
[0071] Further, in the case of a container having an inner surface
made of a synthetic resin, the structure may be a single-layer
structure with which the container as a whole is formed while using
the synthetic resin to form the inner surface thereof, or may be a
laminated-layer structure including layers of other synthetic
resins.
[0072] Specifically, when the inner surface is formed of an olefin
resin or a polyester resin, there can be employed the multi-layer
structure including an oxygen-barrier layer or an oxygen-absorbing
layer laminated via a suitable adhesive resin layer as an
intermediate layer and, further, including, on the outer surface
side, a layer of the same resin as the underlying resin (olefin
resin or polyester resin) that is forming the inner surface.
[0073] The oxygen-barrier layer in the multi-layer structure is
formed of an oxygen-barrier resin such as ethylene-vinyl alcohol
copolymer or polyamide, and the oxygen-barrier resin may be,
further, blended with other thermoplastic resins so far as the
oxygen-barrier property is not impaired.
[0074] As described in JP-A-2002-240813 and the like, the
oxygen-absorbing layer includes an oxidizable polymer and a
transition metal catalyst. Due to the action of the transition
metal catalyst, the oxidizable polymer is oxidized with oxygen;
i.e., oxygen is absorbed and transmission of oxygen is shut off.
The oxidizable polymer and the transition metal catalyst have been
closely described in the above JP-A-2002-240813 and are not
described here in detail. If described, however, representative
examples of the oxidizable polymer are olefin resins having
tertiary carbon atoms (e.g., polypropylene, polybutene-1, or
copolymers thereof), thermoplastic polyester, aliphatic polyamide,
xylene group-containing polyamide resin, and ethylenically
unsaturated group-containing polymers (e.g., polymers derived from
polyene, such as butadiene, etc.). As the transition metal
catalyst, there can be exemplified inorganic salts of transition
metals such as iron, cobalt, nickel, etc., organic acid salts
thereof and complexes thereof.
[0075] Adhesive resins used for adhering the layers have been known
per se., and examples thereof include olefin resins graft-modified
with a carboxylic acid such as maleic acid, itaconic acid or
fumaric acid or with an anhydride thereof, or with an amide or
ester; ethylene-acrylic acid copolymer; ionically crosslinked
olefin copolymer; and ethylene-vinyl acetate copolymer.
[0076] Thicknesses of the above layers may be suitably set
depending on the properties required for the layers.
[0077] It is, further, allowable to provide, as an inner layer, a
reground resin layer using a blend of a virgin resin such as an
olefin resin and scraps such as burrs generated during the
formation of the multi-layer structure. Or in the container having
the inner surface (surface 1 of the above-mentioned structure)
formed from the olefin resin or the polyester resin, it is also
allowable, as a matter of course, to form an outer surface thereof
using the polyester resin or the olefin resin.
[0078] There is no specific limitation on the shape of the
container, either. Namely, the container may assume the form
depending on the material forming the container, such as a cup, a
bottle, a bag (pouch), a syringe, a pot, a tray, etc., and may have
been stretched.
[0079] Specifically, in the case of a synthetic resin container, a
preform having the inner surface is formed by a method known per
se., is subjected to the after-treatments such as sticking a film
thereto by heat-sealing and vacuum forming such as plug assist
forming or blow-forming to form a container. Further, as briefly
described earlier, the coating solution obtained by dispersing the
solid particles 5 in the liquid that forms the liquid film 3 is
sprayed onto the container to form the liquid film 3 in which the
solid particles have been dispersed. Depending on the form of the
container, however, the coating solution is applied by using a
roller, a knife coater, and the like to form the liquid film 3 on
the inner surface of the container.
[0080] FIG. 3 shows a direct blow-formed bottle which is the most
preferred embodiment of the structure of the present invention.
[0081] In FIG. 3, the bottle generally designated at 10 includes a
neck portion 1 having a screw thread, a body wall 15 continuous to
the neck portion 11 via a shoulder portion 13, and a bottom wall 17
that is closing the lower end of the body wall 15. The
above-mentioned liquid film is formed on the inner surface of the
bottle 10 which is filled with, for example, a viscous content.
[0082] The above-mentioned structure of the present invention
exhibits very excellent sliding property depending on the kinds of
the liquid film 3 and the solid particles 5, and exhibits the
effect of preventing the content from adhering and staying on the
bottom portion. Therefore, the structure of the invention can be
favorably used, specifically, as a container for containing viscous
contents having viscosity (25.degree. C.) of not lower than 100
mPas. Specifically, if the liquid film 3 is formed by using the
above-mentioned oily liquid, the structure of the invention is most
desirably used as a bottle for containing viscous contents such as
mayonnaise, ketchup, aqueous paste, honey, various sauces, mustard,
dressing, jam, chocolate syrup, cosmetic such as milky lotion,
liquid detergent, shampoo, rinse, etc.
EXAMPLES
[0083] The invention will now be described by way of the following
Experimental Examples.
[0084] Described below are the container, lubricating liquids
(liquids for forming the liquid film 3) and contents used in
Examples and in Comparative Examples.
<Container>
(1) Sheet Members
[0085] As sheet members, there were used a multi-layer sheet of a
width of 75 mm and a length of 50 mm cut out from a multi-layer
bottle that will be described later, and a glass plate of a width
of 75 mm and a length of 50 mm.
(2) Bottle
[0086] There was used a direct blow-formed multi-layer bottle
having a multilayer structure of the following layer constitution
and having a capacity of 400 g. [0087] Inner layer: low-density
polyethylene resin (LDPE) [0088] Intermediate layer: ethylene-vinyl
alcohol copolymer (EVOH) [0089] Outer layer: low-density
polyethylene resin (LDPE) [0090] Adhesive layers (among the inner
layer, intermediate layer and outer layer): acid-modified
polyolefin
<Liquid Film>
[0090] [0091] (1) Liquid (lubricating liquid) for forming the
liquid film [0092] Edible oil A: [0093] Salad oil to which
medium-chain fatty acid is added (viscosity: 33 mPas (25.degree.
C.), angle of contact: 18 degrees). [0094] Edible oil B: [0095]
Salad oil to which no medium-chain fatty acid is added (viscosity:
80 mPas (25.degree. C.), angle of contact: 18 degrees). [0096] (2)
Solid particles [0097] Rice wax. [0098] Cellulose.
[0099] Coating solutions in which solid particles of specified
particle size were dispersed were prepared by mixing solid
particles into the above-mentioned liquids (lubricating liquids)
used in Examples and Comparative Examples as shown in Table 1 and
stirring them together. The coating solutions were uniformly
applied in specified amounts onto the sheet materials of the
containers and onto the inner surfaces of the bottles.
<Measurements>
Particle Size of the Solid Particles;
[0100] Solid particles were mixed in an amount of 1% into the
edible oil A, and the distribution of particle size was measured by
the laser diffraction scattering method by using a particle size
distribution measuring apparatus (LA-300 manufactured by HORIBA,
Ltd.). A median diameter thereof was regarded to be particle
size.
Angle of Contact;
[0101] The inner surface of the container that is the multi-layer
sheet of the sheet member was left to face upward, and 10 mg of an
edible oil used as the lubricating liquid was dropped thereon. The
angle of contact of the lubricating liquid was measured by using an
instrument for measuring contact angle (Drop Master 700
manufactured by Kyowa Interface Science Co., Ltd.) at 20.degree.
C., 50% RH.
Viscosity;
[0102] A liquid was introduced into a beaker, and a spindle and a
guard of a B-type digital viscometer were put into the liquid.
While maintaining the temperature at 25.degree. C., the spindle was
turned at 10 rpm for one minute to measure the viscosity.
<Content>
[0103] An egg (50 g), 15 cc of vinegar and 2.5 cc of salt were
mixed together and to which 150 cc of edible oil was, further,
added to prepare a mayonnaise-like food for experiment. In Examples
and Comparative Examples, the contents were prepared in required
amounts and were used.
[0104] By using the contents of Examples and Comparative Examples,
further, the sliding properties (sliding properties of the sheet
members) and sliding properties of the bottom portions (bottles)
were evaluated in a manner as described below.
<Evaluating the Sliding Properties>
[0105] The coating solution was applied to the sheet member which
was thereafter held at an angle of 30 degrees (see FIG. 4). 6
Milligrams of the mayonnaise-like food was dropped thereon, and the
time was measured until it moved 5 cm. The sliding properties were
evaluated on the following basis. [0106] .circleincircle.: Moved in
less than 14 seconds. [0107] .largecircle.: Moved in not less than
14 seconds but less than 18 seconds. [0108] .DELTA.: Moved in not
less than 18 seconds. [0109] X: Not slipped down for not less than
60 seconds.
<Evaluating the Sliding Properties on the Bottom Portion of the
Containers>
[0110] A spray nozzle was inserted in the bottle up to the bottom
thereof and was pulled up while spraying the coating solution so
that the coating solution was applied to the whole side wall
surfaces starting from the bottom portion of the bottle. Into the
bottle having the liquid film with the solid particles dispersed
therein formed on the inner surface thereof, 400 g of the content
or the mayonnaise-like food was introduced in a customary manner.
The mouth portion of the bottle was heat-sealed with an aluminum
foil and was sealed with a cap to obtain a filled bottle.
[0111] The bottle filled with the content was stored at 23.degree.
C. for one week. The bottle stored for one week was pressed on its
body portion, and the content was squeezed out up to its last drip
through the mouth portion of the bottle. Thereafter, the air was
introduced into the bottle to restore its original shape.
[0112] Next, the bottle was inverted (mouth portion down) and was
stored for one hour. Thereafter, the body wall of the bottle was
measured in regard to what extent the content has slid down (to
what extent the content has no longer been adhered to the body wall
portion). The content slide-down ratio was calculated in compliance
with the following formula.
Content slide-down ratio (%)=(surface area on which the content is
sliding down/surface area of the body wall of the
bottle).times.100
From the content slide-down ratios calculated above, the sliding
properties were evaluated on the following basis. [0113]
.largecircle.: The content slide-down ratio is not less than 90%.
[0114] .DELTA.: The content slide-down ratio is not less than 50%
but is less than 90%. [0115] X: The content slide-down ratio is
less than 50%.
Examples 1 to 6
[0116] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, coating solutions
obtained by dispersing the rice wax (particle size of 100 .mu.m) in
the edible oil A (lubricating liquid) were applied thereon at solid
particle dispersion ratios and in amounts as shown in Table 1, and
the sliding properties were evaluated.
Example 7
[0117] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, a coating solution was
applied thereon in the same manner as in Example 1 but changing the
solid particles into the rice wax (particle size of 50 .mu.m) at a
solid particle dispersion ratio and in an amount as shown in Table
1, and the sliding property was evaluated.
Example 8
[0118] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, a coating solution was
applied thereon in the same manner as in Example 1 but changing the
solid particles into the rice wax (particle size of 250 .mu.m) at a
solid particle dispersion ratio and in an amount as shown in Table
1, and the sliding property was evaluated.
Example 9
[0119] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, a coating solution was
applied thereon in the same manner as in Example 1 but changing the
lubricating liquid into the edible oil B at a solid particle
dispersion ratio and in an amount as shown in Table 1, and the
sliding property was evaluated.
Example 10
[0120] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, a coating solution was
applied thereon in the same manner as in Example 1 but changing he
solid particles into the cellulose (particle size of 120 .mu.m) at
a solid particle dispersion ratio and in an amount as shown in
Table 1, and the sliding property was evaluated.
Example 11
[0121] By using the glass plate as a material for forming the inner
surface of the packing material, the coating solution was applied
thereon in the same manner as in Example 1 at a solid particle
dispersion ratio and in an amount as shown in Table 1, and the
sliding property was evaluated.
Example 12
[0122] By using the multi-layer bottle as the packing material, a
coating solution obtained by dispersing the rice wax (particle size
of 100 .mu.m) in the edible oil A was applied thereon at a solid
particle dispersion ratio and in an amount as shown in Table 1, and
the sliding property on the bottom portion was evaluated.
Example 13
[0123] By using the multi-layer bottle as the packing material, a
coating solution obtained by dispersing the rice wax (particle size
of 50 .mu.m) in the edible oil A was applied thereon at a solid
particle dispersion ratio and in an amount as shown in Table 1, and
the sliding property on the bottom portion was evaluated.
Example 14
[0124] By using the multi-layer bottle as the packing material, a
coating solution obtained by dispersing the rice wax (particle size
of 250 .mu.m) in the edible oil A was applied thereon at a solid
particle dispersion ratio and in an amount as shown in Table 1, and
the sliding property on the bottom portion was evaluated.
Comparative Examples 1 and 2
[0125] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, a coating solution
obtained by dispersing the rice wax (particle size of 100 .mu.m) in
the edible oil A was applied thereon at solid particle dispersion
ratios and in amounts as shown in Table 2, and the sliding
properties were evaluated.
Comparative Example 3
[0126] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, a coating solution
obtained by dispersing the rice wax (particle size of 350 m) in the
edible oil A was applied thereon at a solid particle dispersion
ratio and in an amount as shown in Table 2, and the sliding
property was evaluated.
Comparative Example 4
[0127] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, the edible oil A was
applied thereon in an amount as shown in Table 2, and the sliding
property was evaluated.
Comparative Example 5
[0128] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, the rice wax applied
thereon in an amount of 2.5 g and, thereafter, the edible oil A was
applied thereon in an amount as shown in Table 2, and the sliding
property was evaluated.
Comparative Example 6
[0129] By using the multi-layer sheet as the material for forming
the inner surface of the packing material, the sliding property was
evaluated but without applying the lubricating liquid.
Comparative Example 7
[0130] By using the multi-layer bottle as the packing material, the
edible oil A was applied thereon, and the sliding property on the
bottom portion was evaluated.
Comparative Example 8
[0131] By using the multi-layer bottle as the packing material, the
sliding property on the bottom portion was evaluated but without
applying the lubricating liquid.
[0132] Tables 1 and 2 show the results of evaluation in the above
Examples and Comparative Examples.
[0133] In Tables 1 and 2, Ex. stands for Examples and Com. stands
for Comparative Examples.
TABLE-US-00001 TABLE 1 Evaluation Coating solution Coating Sliding
Lubricating Solid weight Sliding property Base material liquid
particles (mg/cm.sup.2) *1 down on bottom Ex. 1 multi-layer sheet
edible oil A *2 (*4, 100 .mu.m) 2.4 3 .circleincircle. -- Ex. 2
.uparw. .uparw. .uparw. 1 3 .largecircle. -- Ex. 3 .uparw. .uparw.
.uparw. 6.2 3 .largecircle. -- Ex. 4 .uparw. .uparw. .uparw. 2.4
0.01 .largecircle. -- Ex. 5 .uparw. .uparw. .uparw. 2.4 5
.circleincircle. -- Ex. 6 .uparw. .uparw. .uparw. 2.4 10
.largecircle. -- Ex. 7 .uparw. .uparw. *2 (*4, 50 .mu.m) 2.4 3
.largecircle. -- Ex. 8 .uparw. .uparw. *2 (*4, 250 .mu.m) 2.4 3
.largecircle. -- Ex. 9 .uparw. edible oil B *2 (*4, 100 .mu.m) 2.4
3 .largecircle. -- Ex. 10 .uparw. edible oil A *3 (*4, 120 .mu.m)
2.4 3 .largecircle. -- Ex. 11 glass plate .uparw. *2 (*4, 100
.mu.m) 2.4 3 .largecircle. -- Ex. 12 bottle .uparw. .uparw. 2.4 3
-- .largecircle. Ex. 13 .uparw. .uparw. *2 (*4, 50 .mu.m) 2.4 3 --
.largecircle. Ex. 14 .uparw. .uparw. *2 (*4, 250 .mu.m) 2.4 3 --
.largecircle. *1: solid particle dispersion ratio (g/100 g of
liquid), *2: rice wax, *3: cellulose, *4: particle size
TABLE-US-00002 TABLE 2 Evaluation Coating solution Coating Sliding
Lubricating Solid weight Sliding property Base material liquid
particles (mg/cm.sup.2) *1 down on bottom Com. 2 .uparw. .uparw.
.uparw. 2.4 20 .DELTA. -- Com. 3 .uparw. .uparw. *2 (*3, 350 .mu.m)
2.4 3 .DELTA. -- Com. 4 .uparw. .uparw. -- 2.4 -- .DELTA. -- Com. 5
.uparw. edible oil A was applied 2.4 -- .DELTA. -- after rice wax
has adhered Com. 6 .uparw. -- -- -- -- X -- Com. 7 bottle edible
oil A -- 2.4 -- -- .DELTA. Com. 8 .uparw. -- -- -- -- -- X *1:
solid particle dispersion ratio (g/100 g of liquid), *2: rice wax,
*3: particle size
[0134] Upon forming the liquid film in which the solid particles
are dispersed on the inner surface of the sheet member and the
bottle, improved sliding property is exhibited to the content. It
will, therefore, be learned that the packing material exhibits
excellent sliding property to the content if it has the liquid film
formed on the inner surface thereof by applying the coating
solution prepared by dispersing the solid particles in the liquid
onto the inner surface thereof.
Experimental Examples 1 to 4
[0135] In compliance with the above Examples, the coating solutions
shown in Table 3 were applied each in an amount of 0.6 cc onto the
glass members (preparates) and were allowed to cover the whole
surfaces thereof. Thereafter, the peparates were held vertically
for 30 seconds and were returned to the horizontal state to measure
the remaining ratios (%) of the coating solutions per the areas.
The results were as shown in Table 3.
TABLE-US-00003 TABLE 3 Ratio of solid particles Remaining dispersed
(g/100 g of liquid layer) ratio (%) Experimental 0 2 Example 1
Experimental 0.1 9 Example 2 Experimental 1 39 Example 3
Experimental 10 85 Example 4
[0136] As will be obvious from Table 3, the higher the ratio of the
solid particles in the liquid film, the higher the remaining ratio
of the liquid film and the solid particles.
[0137] Though not shown in Table, if the ratio of the solid
particles is too high in the liquid film, the solid particles may
aggregate together and may hinder the content from sliding down or
may infiltrate into the content. Therefore, the ratio thereof is,
desirably, 0.01 to 10% and, specifically, 0.1 to 5%.
DESCRIPTION OF REFERENCE NUMERALS
[0138] 1: inner surface of the structure [0139] 2: liquid [0140] 3:
liquid film [0141] 5: solid particles [0142] 10: bottle [0143] 11:
neck portion [0144] 13: shoulder portion [0145] 15: body wall
[0146] 17: bottom wall
* * * * *