JP2006076647A - Thermal insulation composite container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite container that is thermally insulated and lightweight and covered with a resin film without causing a surface failure. <P>SOLUTION: In the thermal insulation composite container 1, its body includes an inner layer 2 containing bulk-processed pulp, and an outer layer 3 mainly made of pulp and having density higher than that of the inner layer 2. The body of the container 1 has a stacking step and the lower part from the step is made thinner than the top of the step. It is preferable that the angle of the taper of the internal face of the body extending from the step toward the bottom is smaller than the angle of the taper of the external face of the body. In addition, it is preferable that the curvature radius Ro of the external angular part of the bottom and the curvature radius Ri of its internal angular part are 0≤Ro≤5 mm and Ro-0.5 mm<Ri<Ro+1 mm (wherein Ri is 0 when Ro is 0 to 0.5). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-insulating composite container having an inner layer and an outer layer in a body portion.

  The applicant has previously proposed the technique described in Patent Document 1 below regarding a composite container including a low-density inner layer and a high-density outer layer in a body portion and provided with a stacking step on the inner surface of the body portion. . In addition, the level | step difference for stacking means the site | part which contact | abuts to this bottom part in the state which supports the bottom part of the stacked container, when a container is stacked.

  When the inner surface of such a composite container is coated with a resin film by a molding method such as vacuum molding, surface defects such as cracks and kinks may occur on the inner surface (inner layer) of the body portion. As a means for solving such a problem, for example, it is conceivable to increase the strength by partially increasing the density of a portion where surface defects are likely to occur in the trunk portion as in Patent Document 2 below. The container obtained in (1) cannot obtain the desired heat insulating property and also increases the weight of the container. In addition, in terms of manufacturing, there are problems such as an increase in drying time.

JP 2003-113600 A JP-A-10-131100

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a composite container that has a heat insulating property and a light weight and is covered with a resin film without causing surface defects.

  The present inventors have found that when the inner surface of the composite container is coated with a resin film by vacuum forming, cracks and kinks generated in the composite container during vacuum forming mainly occur below the stacking step. And it discovered that the said objective can be achieved by changing the thickness of a trunk | drum rather than pressing a trunk | drum partially and densifying and raising intensity | strength.

  The present invention has been made on the basis of the above knowledge, and is a composite container having an inner layer containing bulky treated pulp and an outer layer mainly composed of pulp and having a higher density than the inner layer, The above-mentioned object is achieved by providing a heat insulating composite container having a stacking step and the body portion below the stacking step being thinner than the thickness of the top of the stacking step. It is a thing.

  ADVANTAGE OF THE INVENTION According to this invention, the composite container which has heat insulation and lightweight property, and an inner surface is coat | covered favorably with a resin film is provided.

  The present invention will be described below based on preferred embodiments with reference to the drawings.

  FIG. 1 shows an embodiment in which the heat insulating composite container of the present invention is applied to a food container such as instant cup noodles. In FIG. 1, the code | symbol 1 has shown the heat insulation composite container.

  The heat insulating composite container 1 includes an inner layer container (inner layer) 2 containing bulky treated pulp, and an outer layer container (outer layer) 3 mainly composed of pulp and having a higher density than the inner layer container 2. The heat insulating composite container 1 has a flange portion 11 at the peripheral edge portion of the mouth portion 10. The heat insulating composite container 1 includes a coating layer 4 made of a resin film extending from the inner surface of the inner layer container 2 to the flange portion 11.

  The heat insulating composite container 1 has a stacking step (hereinafter also simply referred to as a step) 13 formed on the inner surface of the body 12. For this reason, loading and separation after molding can be performed easily. The thickness of the trunk portion 12 below (bottom side) of the stack step 13 is thinner than the step 13. When forming the coating layer 4 of the heat insulating composite container 1, the present inventors have surface defects such as cracks and kinks in the inner layer in the lower part of the stacking step, and the base point (starting point) is particularly the step. It was found that it is a bottom corner portion of the inner layer 2 including 13 bottom side portions. And by reducing the thickness of the body part below the stacking step 13 and reducing the compression strain due to vacuum forming, the occurrence of surface defects such as cracks and kinks in the inner layer without increasing the density. It was found that a heat-insulating composite container having a good coating layer was obtained.

  Further details will be described below. First, the mechanism by which surface defects such as cracks and kinks occur in the inner pulp of the stack step during vacuum forming will be described. In the vacuum forming step, the resin film is gradually bonded from the bottom and the body toward the bottom corner. At this time, the resin film is bonded to the inner layer while compressing the inner layer by vacuum pressure and pressing the inner layer against the outer layer and the mold. Here, even in the circumferential direction of the inner surface of the container, the resin film and the inner layer are adhered, and a pressing time difference occurs. Finally, the resin film is adhered to the inner layer, that is, at the part of the bottom corner, the inner layer is deformed. Therefore, it is considered that surface defects such as cracks and kinks are generated with the bottom corner as a base point. In particular, when the inner layer is low density and the compressive strain is large as in the present embodiment, when the inner layer and the outer layer are not firmly bonded to each other, or when the shape of the vacuum mold and the inner layer is not sufficiently matched The inner layer undergoes the largest deformation strain, and surface defects such as cracks and kinks tend to occur in the inner layer. Therefore, it has been found that the occurrence of surface defects such as cracks and kinking of the inner layer can be prevented by reducing the thickness of the body portion, particularly the inner layer thickness of the lower portion of the stack step, and reducing the amount of compression by vacuum forming. .

  In the heat insulating composite container 1, the thickness of the body portion 12 is thin at a portion below the step 13 for stacking. It is preferable that this portion is continuously thinner as it goes downward, but the thickness below the top of the stack step (on the bottom side) should not exceed the thickness of the top. Here, the top part of the stack step refers to the thickest part between the step part and the bottom part of the trunk part. More specifically, in the heat insulating composite container of the present embodiment, the stacking step and the shape in the vicinity thereof are formed with a downward slope from the step start point S as shown in FIG. After the point P, the thickness decreases toward the bottom. The point where the thickness of the inner layer is the maximum is the peak portion P, and the thickness at the peak portion P is the thickness W of the peak portion.

  In the heat insulating composite container 1, the taper angle θ <b> 2 of the inner surface of the body portion 12 on the bottom side from the stack step 13 is smaller than the taper angle θ <b> 1 of the outer surface of the body portion 12. By setting the taper angle of the inner surface and the taper angle of the outer surface and reducing the thickness of the body portion 12 below the stacking step 13 (bottom side), heat insulation and lightness are impaired. In addition, it is possible to cover the resin film by preventing breakage of the pulp in the inner layer.

  The taper angle θ1 of the outer surface of the body portion 12 on the bottom side of the stack step 13 is 3 to 10 degrees in consideration of ease of use as a container, internal volume, moldability, ease of loading and separation after molding, and the like. In particular, 5 to 8 degrees is preferable. The taper angle θ2 of the inner surface of the body portion 12 on the bottom side from the stacking step 13 does not impair the heat insulating property and light weight of the container as described above, and is vertical to the inner layer 2 when the coating layer 4 is formed by vacuum forming. In consideration of preventing the occurrence of cracks, it is preferably 2 to 9 degrees, particularly 4 to 7 degrees, but 3.5 degrees or more in consideration of releasability from the core (papermaking mold) of the molded body. It is preferable that

  As for the heat insulation composite container 1, the opening edge part of the opening | mouth part 10 is processed into the curved surface. The curvature radius R10 of the opening edge is preferably 0.5 to 3 mm, particularly preferably 1 to 2 mm. By making curvature radius R10 into such a range, while the strength reduction of the corner | angular part of an opening edge part is suppressed, fuzz is prevented by the press effect at the time of shaping | molding. In addition, the mouth feel during use is good, and breakage during the formation of the coating layer 4 can be prevented.

  As shown in FIG. 1B, the flange portion 11 is formed by covering the flange portion 21 of the inner layer container 2 and the flange portion 31 of the outer layer container 3 with the covering layer 4. For this reason, when it drinks liquid things, such as soup, a liquid substance does not permeate from the edge part of a flange part. Further, when the lid is attached and removed, the flange portion 21 of the inner layer container 2 and the flange portion 31 of the outer layer container 3 are not peeled off. Further, the coating layer 4 is not peeled off from the flange portion 21 of the inner layer container 2 and the flange portion 31 of the outer layer container 3. Moreover, although the edge part of the flange part 21 of the inner layer container 2 and the flange part 31 of the outer layer container 3 are coat | covered, since the trunk | drum 12 is not coat | covered, even when printing etc. are carried out to the trunk | drum 12. Since the end of the coating layer 4 does not come to the inside and is not visually recognized, the aesthetic appearance is also excellent.

  The width W11 of the upper surface portion (flat portion) 110 of the flange portion 11 is preferably 1.0 to 5 mm, particularly preferably 1.5 to 4 mm. By setting the width W11 within such a range, a decrease in strength of the flange portion 11 can be suppressed, and when the lid is attached, a bonding area where good bonding strength and sealing properties can be obtained can be secured.

  The thickness of the flange portion 11 (all layer thickness) T11 is to prevent deformation of the mouth when holding the container by hand (gripping strength), to prevent deformation of the flange when the lid is attached and peeled off, thin and lightweight, Further, considering the goodness of mouth feel at the time of use, it is preferably 0.8 to 5 mm, more preferably 1 to 3.5 mm, and still more preferably 1.2 to 2.5 mm.

  The heat insulating composite container 1 has a portion in the body portion 12 where the total layer thickness and the inner layer density are different in the vertical direction. Here, in this specification, a density means a bulk density.

The thickness T121 in the vicinity of the mouth portion of the body portion 12 prevents the mouth portion from being deformed (gripping strength) when the container is held by hand, prevents buckling in the vicinity of the mouth portion of the body portion 12 under vertical load, and is thin and lightweight. In consideration of the above, it is preferably 0.8 to 3.5 mm, more preferably 0.9 to 2.6 mm, and still more preferably 1 to 2.1 mm.
The thickness T122 in the central portion of the body portion 12 is preferably 0.7 to 3 mm, more preferably 0.8 to 2.2 mm, and still more preferably 0.9 to 2 mm in consideration of heat insulation, thinness, lightness, and the like. It is.
The thickness T123 in the lower part of the body 12 is preferably 0.7 to 4 mm, more preferably 0.8 in consideration of securing the thickness necessary for the stack step and considering the strength, heat insulation, thinness, lightness, etc. of the stack. It is -3.1mm, More preferably, it is 0.9-2.5mm. In the present specification, the vicinity of the mouth portion of the body portion 12 refers to a portion of 0 to 20% from the upper surface portion 110 of the flange portion 11 with respect to the height H of the heat insulating composite container 1. The lower portion of the trunk portion 12 refers to a portion from the stacking step 23 to the bottom surface not including the bottom ground contact surface. The bottom portion refers to a portion including a raised bottom and a bottom grounding surface.

  The heat insulating composite container 1 has a raised bottom portion 141 in which the center portion of the bottom portion 14 is raised to a predetermined height, and a flat grounding portion 142 on the outer side thereof. The thickness T14 of the bottom portion 14 (thickness in the ground contact portion 142) is 0.4 to 2.8 mm, preferably 0.5 to 2 mm, more preferably in consideration of heat insulation, longitudinal compressive strength, thinness / lightness, and the like. Is 0.7-1.8 mm.

  It is preferable that the thickness T14 of the bottom portion 14 is provided to be thinner than the trunk thickness (T121, T122) above the stack step. Thus, by making the thickness of the bottom portion 14 thinner than the thickness of the trunk portion above the stack step, the compression strain due to vacuum forming can be reduced, so that surface defects such as cracks and kinks in the inner layer pulp starting from the bottom corner can be prevented. It is effective in preventing the occurrence. In particular, when T123> T124> T122> T14, it is possible to prevent the occurrence of surface defects such as cracking and kinking of the inner pulp during vacuum forming while satisfying the heat insulation, strength, thinness, and lightness as a container. It is preferable because it is possible. Here, the thickness of the bottom portion 14 is thinner than the thickness of the trunk portion above the stack step, and it is preferable that the maximum thickness of the bottom portion 14 is thinner than the thinnest thickness of the trunk portion above the stack step. It is sufficient that the average thickness is smaller than the average thickness of the trunk portion above the stack step.

  The inner layer container 2 is a pulp mold container having a flange portion 21. The inner layer container 2 is a container that imparts heat insulation to the heat insulating composite container 1 as an inner layer and cushioning the flange portion 11. On the inner surface of the body portion 22 of the inner layer container 2, a step (not shown) is formed on the inner surface of the inner layer container 2 to become the stacking step 23 and the hot water line 15.

  The thickness T21 of the flange portion 21 of the inner layer container 2 constituting the flange portion 11 is to prevent deformation of the mouth when the container is held by hand, flange strength when the lid is attached and peeled off, cushioning property of the flange portion, In consideration of thinness and light weight, good mouth feel, etc., the thickness is preferably 0.4 to 3 mm, more preferably 0.5 to 2 mm, and still more preferably 0.6 to 1.5 mm. The thickness T221 of the body portion 22 of the inner container 2 that constitutes the vicinity of the mouth portion 10 of the body portion 12 is heat-insulating, preventing mouth deformation when the container is held by hand (gripping strength), and compressive load in the vertical direction. Considering prevention of buckling in the vicinity of the mouth portion of the body portion 12 when loaded, thinness, lightness, etc., preferably 0.55 to 2 mm, more preferably 0.6 to 1.7 mm, and still more preferably 0. .65 to 1.4 mm. The thickness T222 of the body portion 22 of the inner layer container 2 constituting the central portion of the body portion 12 is preferably 0.5 to 1.8 mm, more preferably 0.55 in consideration of heat insulation, thinness, lightness, and the like. It is -1.5mm, More preferably, it is 0.6-1.4mm. The thickness T223 of the body portion 22 of the inner layer container 2 constituting the lower portion of the body portion 12 is heat insulation, ensuring the thickness necessary for the step for stacking, and when the coating layer 4 is formed by vacuum forming, the inner layer 2 is In consideration of preventing kinking and breaking, thinness, lightness, and the like, the thickness is preferably 0.55 to 3 mm, more preferably 0.65 to 2.5 mm, and further preferably 0.7 to 2 mm. The thickness T24 of the bottom portion 24 of the inner layer container 2 constituting the bottom portion 14 is preferably 0.3 to 1.8 mm, more preferably 0.4 in consideration of heat insulation properties, longitudinal compressive strength, thinness / lightness, and the like. It is -1.5mm, More preferably, it is 0.55-1.4mm.

  Insulation composite container 1 has a gripping strength of 3.5 N or more, particularly 5 N or more considering that it is small in deformation when hot water is put in and held by hand, there is no risk of spilling hot water, and it is easy to hold. Is preferred. Here, for the gripping strength, a compression tester (Orientec Co., Ltd., Tensilon RTA500) was used, and with the heat insulating composite container placed sideways, the flange portion was pressed from above with a load cell speed of 20 mm / min. A compression test is performed, and a 5 mm displacement load obtained from the load cell displacement and the load change is used.

  The heat insulating composite container 1 preferably has a buckling strength of 245 N or more, particularly 394 N or more in consideration of prevention of crushing during container transportation and stacking. Here, the buckling strength of the heat-insulating composite container is fixed to a compression tester (Orientec, Tensilon RTA500) with the mouth of the heat-insulating composite container facing up, and a compression test is performed with a presser at a load cell speed of 20 mm / min. And measuring changes in displacement and load until buckling occurs. Note that the compression test is performed while releasing the load at one point when the load reaches 10 kgf and confirming the state of crushing, repeating the same measurement by raising the load every 5 kgf, and checking each time.

  The heat insulating composite container 1 is preferably 45 to 75 ° C., particularly 50 to 70 ° C., considering that the heat insulating composite container 1 is held by hand even when hot water is added and is thin and lightweight and has a predetermined strength. Here, heat insulation is measured by the measuring method of the Example mentioned later.

  The heat insulating composite container 1 has a peel strength of the covering layer 4 in the flange portion 11 of 15 to 30 N, particularly 18 to 25 N, considering the storage stability of the contents after sealing the lid and the ease of peeling of the lid during use. Preferably there is. Here, the peel strength of the covering layer is determined by fixing the heat insulating composite container to a tensile tester (Orientec Co., Ltd., Tensilon RTA500) with the mouth facing up after the lid is heated and bonded to the flange part of the heat insulating composite container. This is a value obtained as a load when the grip portion of the lid is gripped with a chuck, a tensile test is performed at a load cell speed of 300 mm / min, and the lid is first opened from the flange portion.

The heat insulating composite container 1 has a water vapor barrier property of 30 g / m ² · 24 h or less in consideration of the stable storage stability of the contents and the fact that steam is not attached to the desk even when hot water is put into the container 1. In particular, it is preferably 20 g / m ² · 24 h or less, more preferably 10 g / m ² · 24 h or less. Here, the water vapor barrier property of the heat insulating composite container is measured in accordance with JIS Z-0208 by taking a sample from the body of the heat insulating composite container.

  The heat insulating composite container 1 takes into consideration that the coating layer 4 is coated without thickness unevenness by vacuum forming or pressure forming, prevention of pinholes, or uniform bonding between the coating layer 4 and the inner layer container 2. The air permeability is 30 seconds to 120 seconds, preferably 40 to 60 seconds, more preferably 45 seconds to 55 seconds. Here, the air permeability is measured by a measuring method of an example described later.

  The total weight of the heat insulating composite container 1 is 10 to 30 g, preferably 10 to 25 g, more preferably 12 to 23 g in consideration of disposal property, cost, strength, heat insulating property and the like.

The inner layer container 2 preferably has a density of 0.05 to 0.8 g / cm ³ , particularly 0.1 to 0.8 g / cm ³ . By setting the density within such a range, the heat insulating composite container can be provided with good heat insulating properties, and the container weight can be reduced. In addition, the gripping strength and compressive strength of the heat insulating composite container 1 can be improved.

The density ρ21 of the flange portion 21 of the inner layer container 2 is preferably in consideration of prevention of mouth deformation when the container is held by hand, flange strength when the lid is attached and peeled off, cushioning properties of the flange portion, etc. It is 0.2-1.5 g / cm < ³ >, More preferably, it is 0.2-0.8 g / cm < ³ >, More preferably, it is 0.3-0.6 g / cm < ³ >.

The density ρ221 of the body portion 22 of the inner layer container 2 constituting the vicinity of the mouth portion 10 of the body portion 12 is a heat insulating property, a mouth deformation preventing mouth portion when the container is held by hand, and a mouth caused by a longitudinal compressive load. In consideration of buckling prevention at the part, it is preferably 0.2 to 0.8 g / cm ³ , more preferably 0.3 to 0.7 g / cm ³ .
The density ρ222 of the body portion 22 of the inner layer container 2 constituting the central portion of the body portion 12 is considered for heat insulation, prevention of dent of the body portion when holding the container by hand, and prevention of deformation due to printing pressure during printing. Then, it is preferably 0.05 to 0.5 g / cm ³ , more preferably 0.1 to 0.4 g / cm ³ .
The density ρ223 of the body portion 22 of the inner layer container 2 constituting the lower portion of the body portion 12 is heat-insulating, prevents dents in the body portion when the container is held by hand, prevents deformation due to printing pressure during printing, etc. Considering it, it is preferably 0.05 to 0.5 g / cm ³ , more preferably 0.1 to 0.4 g / cm ³ .
The density ρ24 of the bottom 24 of the inner layer container 2 constituting the bottom 14 is preferably 0.2 to 1.5 g / cm ³ in consideration of heat insulation, prevention of buckling of the bottom due to a compressive load in the vertical direction, and the like. Preferably it is 0.2-0.8 g / cm < ³ >, More preferably, it is 0.3-0.8 g / cm < ³ >.

  The inner layer container 2 is preferably provided with a smoother inner surface than an outer surface. The surface roughness of the inner surface of the inner layer is preferably 3 to 15 μm, more preferably 3 to 12 μm, considering pinhole prevention of the coating layer 4, adhesiveness between the coating layer 4 and the inner layer container 2, good appearance, etc. More preferably, it is 4-7 micrometers. The surface roughness of the outer surface of the inner layer is preferably 4 to 20 μm, more preferably 5 to 5 μm, considering that the friction with the outer layer container 3 is increased and the inner layer and the outer layer are not separated without using an adhesive. It is 15 μm, more preferably 6 to 10 μm. The surface roughness is measured using Surfcom (manufactured by Tokyo Seimitsu Co., Ltd.) in accordance with JIS B0601-2001 (measurement conditions are Gaussian correction, inclination correction: straight line).

  The inner layer container 2 preferably has an air permeability that allows the coating layer 4 to be easily deformed by suction during vacuum forming.

  The inner layer container 2 contains bulky treated pulp as a pulp component. The amount of the bulky treated pulp contained in the inner layer container 2 is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and still more preferably 30 to 70% by weight in the pulp components constituting the inner layer container 2. When the blending amount of the bulky treated pulp in the pulp component is within such a range, the bulky effect is exhibited, and the cushioning property of the flange portion 11 and the heat insulating property of the container are improved. In addition, the amount of binder used for securing the strength of the container and the flange portion can be suppressed to an appropriate amount. Here, the bulky treated pulp used in the inner layer container 2 refers to a pulp fiber that has been curled or hydrophobized by a bulky treatment such as a crosslinking treatment or mercerization treatment, or the rigidity of the fiber itself has been improved. As the cross-linked pulp, commercially available curd fibers (for example, “HBA” manufactured by U.S. Warehauser), and as the mercerized pulp, commercially available mercerized pulp (for example, “POROSAUIE”, “ULTRANIER,” manufactured by Rayonnia) are used. “SULFATE” can be mentioned.

The cross-linked pulp, mercerized pulp or bulky treated pulp can be used alone or in combination of two or more.
The mercerized pulp can be used by mixing with the crosslinked pulp at an appropriate ratio. Mercerized pulp is less bulky than crosslinked pulp, but by adjusting the mixing ratio of mercerized pulp to crosslinked pulp, the strength of the inner layer container and the moldability (transferability) of the inner surface of the inner layer container are improved. It becomes good. Moreover, flocs of pulp fibers can be suppressed, and the occurrence of papermaking unevenness can be prevented.

When the crosslinked pulp is used among the bulky treated pulp, the wet curled factor is preferably 0.1 to 1.0, particularly preferably 0.1 to 0.6. By setting the wet curled factor within such a range, desired bulkiness can be easily obtained. Further, the dispersibility in the raw material slurry is also good, the papermaking unevenness can be suppressed and uneven thickness can be prevented from occurring in the compact, and the strength and surface properties of the compact can be improved. Here, the wet curled factor, using the FQA (Fiber Quality Analyzer) was dipped in pure water at room temperature of pulp fibers, measuring the number 1000 or more, the measurement range 0.5~10mm, ((L _A / L _B ) is a value obtained by the arithmetic average of -1) and is a numerical value indicating the degree of fiber curving. However, L _A is the actual pulp fibers length, L _B is the maximum dimension of the rectangle surrounding the pulp fibers bent state.

  The inner layer container 2 can contain, as the pulp component, pulp fibers that are not subjected to bulky treatment in addition to the bulky treated pulp. The pulp fiber is preferably contained in the pulp component in an amount of 10 to 90% by weight, particularly 20 to 80% by weight. When the pulp fiber is contained in such a range, the strength reduction of the flange portion and the container and the generation of paper dust can be suppressed, and the amount of binder added for obtaining strength and preventing paper dust can be suppressed. . Moreover, bulkiness is also obtained and the cushioning property of the flange portion and the heat insulating property of the container are improved. Examples of the pulp fibers include unbleached or bleached kraft pulp, sulfite pulp, alkali pulp, ground pulp, or thermomechanical pulp of softwood or hardwood. These pulp fibers can be used alone or in admixture of two or more at an appropriate ratio. In particular, by mixing two or more kinds, pulp fibers having various fiber length distributions can be prepared.

The pulp fibers for the inner layer preferably have a Canadian Standard Freeness (CSF) of 500 to 800 ml, particularly 600 to 750 ml. When the CSF is within this range, the drainage is good and the paper making time and drying time can be shortened. Further, papermaking unevenness can be suppressed, and uneven thickness can be prevented from being obtained in the obtained molded body, and the surface property of the molded body can be prevented from being deteriorated. Furthermore, desired heat insulation can be obtained.
The pulp fibers for the outer layer preferably have a CSF of 200 to 600 ml, particularly 300 to 600 ml. When the CSF is within this range, the drainage is good and the paper making time and drying time can be shortened. Further, papermaking unevenness can be suppressed, and uneven thickness can be prevented from being obtained in the obtained molded body, and the surface property of the molded body can be prevented from being deteriorated.

  The average fiber length of the pulp fibers not subjected to bulky treatment is preferably 0.4 to 5 mm, particularly preferably 0.5 to 3 mm. When the average fiber length of the pulp fibers is within such a range, moderate entanglement with the bulky treated pulp can be obtained, and the resulting molded article can be prevented from strength reduction and paper dust generation. Moreover, since flocs (aggregation of pulp fibers) do not increase and papermaking unevenness is unlikely to occur, it is possible to prevent uneven thickness from occurring and deterioration of surface properties.

  Any of the pulp fibers of wood pulp and non-wood pulp can be used for the bulky treated pulp and the pulp fiber used as the pulp component of the inner layer container 2. Further, any pulp fiber of virgin pulp and waste paper pulp can be used. These pulp fibers can be used alone or in admixture of two or more at an appropriate ratio.

The inner layer container 2 may contain 0.2 to 10% by weight of a bulking agent. By including a bulking agent within these ranges, bulkiness can be obtained more stably.
Examples of the bulking agent include “KB115” and “KB85” manufactured by Kao Corporation, and among these, “KB115” is preferable because it can suppress bulkiness and obtain bulkiness. .

  The inner layer container 2 may contain additives for the inner layer such as a dispersant, a pigment, a fungicide, a sizing agent, a paper strength enhancer, a water resistance agent, and an adhesive in an appropriate ratio as necessary.

  The outer layer container 3 is a container that mainly gives strength to the heat insulating composite container 1. The outer layer container 3 has a flange portion 31 that constitutes the flange portion 11.

  The thickness T31 of the flange portion 31 of the outer layer container 3 is preferably 0 in consideration of prevention of mouth deformation when the container is held by hand, flange strength when the lid is attached and peeled off, thinness, light weight, etc. .4 to 2 mm, more preferably 0.5 to 1.5 mm, and still more preferably 0.6 to 1.0 mm. The thickness T321 of the body portion 32 of the outer layer container 3 constituting the vicinity of the mouth portion 10 of the body portion 12 is to prevent deformation of the mouth portion when the container is held by hand, and at the mouth portion due to a compressive load in the vertical direction. In consideration of buckling prevention, thin wall, light weight, etc., the thickness is preferably 0.25 to 1.5 mm, more preferably 0.3 to 0.9 mm, and still more preferably 0.35 to 0.7 mm. The thickness T322 of the barrel portion 32 of the outer layer container 3 constituting the central portion of the barrel portion 12 prevents deformation of the barrel portion when the container is held by hand, prevents deformation due to printing pressure during printing, and is thin and lightweight. In consideration of the above, it is preferably 0.2 to 1.2 mm, more preferably 0.25 to 0.7 mm, and still more preferably 0.3 to 0.6 mm. The thickness T323 of the body portion 32 of the outer layer container 3 constituting the lower portion of the body portion 12 is 0.15 to 0 in consideration of prevention of buckling at the bottom due to a compressive load in the vertical direction, thinness, lightness, and the like. .6 mm, particularly preferably 0.2 to 0.5 mm. The thickness T34 of the bottom 34 of the outer container 3 constituting the bottom 14 is preferably 0.1 to 1 mm, more preferably 0 in consideration of buckling prevention at the bottom due to a compressive load in the vertical direction, thin wall, light weight, and the like. 0.1 to 0.5 mm, more preferably 0.15 to 0.4 mm.

Density ρ31 of the flange portion 31 of the outer layer container 3 is the deformation prevention (gripping strength) of the container when the container is held by hand, the deformation prevention of the flange part when the lid is attached and peeled off, the thin wall, and the light weight In consideration of the above, it is preferably 0.5 to 2 g / cm ³ , more preferably 0.7 to 1.5 g / cm ³ .

The density ρ321 of the body portion 32 of the outer layer container 3 constituting the vicinity of the mouth portion of the body portion 12 is surface smoothness, prevention of paper dust generation, prevention of deformation of the container when the container is held by hand (gripping strength), In consideration of buckling prevention at the mouth due to a compressive load in the vertical direction, thinness, lightness, etc., it is preferably 0.5 to 2 g / cm ³ , more preferably 0.7 to 1.5 g / cm ³ .
The density ρ 322 of the body portion 32 of the outer layer container 3 constituting the center portion of the body portion 12 is the surface smoothness, the prevention of paper dust generation, the prevention of dents during transportation, the body when the container is held by hand with hot water. In consideration of prevention of deformation of parts, deformation prevention due to printing pressure at the time of printing, thinness, and lightness, it is preferably 0.5 to 2 g / cm ³ , more preferably 0.7 to 1.5 g / cm ³ .
The density ρ 323 of the body portion 32 of the outer container 3 constituting the lower portion of the body portion 12 takes into account surface smoothness, prevention of dents during conveyance, prevention of deformation due to printing pressure during printing, thinness, lightness, etc. Then, Preferably it is 0.5-2 g / cm < ³ >, More preferably, it is 0.7-1.5 g / cm < ³ >.
The density ρ34 of the bottom 34 of the outer container 3 constituting the bottom 14 is preferably 0.5 to 2 g / cm ³ , considering the prevention of crushing of the bottom at the time of stacking or transporting, thin wall, light weight, etc. Is 0.7 to 1.5 g / cm ³ .

  The outer layer container 3 is preferably provided with a smooth outer surface rather than an inner surface. The surface roughness of the inner surface of the outer layer container 3 is preferably 0.5 to 3 μm, particularly preferably 1 to 2 μm in consideration of printability, prevention of paper dust generation, good appearance, and the like. A mesh is preferably formed on the inner surface of the outer layer container 3. In consideration of printing, labeling, paper dust generation prevention, and the like, it is preferable that the outer surface of the outer container 3, particularly the outer surface of the body portion, has no suction holes.

Outer container 3 is preferably a density of 0.5 to 2 g / cm ^3, more preferably 0.7~1.5g / cm ^3. When the density is in such a range, the pressure applied to the molded body during dry molding does not become excessive, and it is possible to prevent the discoloration of the pulp fibers and the strength of the pulp fibers themselves, and the strength and surface required for the outer layer container. Sex is secured. Here, the density of the outer layer container 3 is determined from the thickness, area, and weight of the cut outer layer container.

  The density of the outer layer container 3 is preferably 1.5 to 30 times that of the inner layer container 2, and more preferably 2 to 10 times. When the density of the outer layer container 3 is in such a range with respect to the density of the inner layer container 2, deformation when the container is gripped can be suppressed, and the smoothness of the outer surface can be improved. Moreover, the strength of the flange portion can be sufficiently obtained. Furthermore, the smoothness and strength of the inner surface are sufficient, and it is possible to prevent the inner surface from being crushed when a covering layer is formed by stretching a resin film as will be described later.

  Examples of the pulp fibers constituting the outer layer container 3 include unbleached or bleached kraft pulp, sulfite pulp, alkali pulp, ground pulp, and thermomechanical pulp. Among these, bleached kraft pulp of conifers and hardwoods is particularly preferable from the viewpoints of moldability, whiteness, surface properties of the molded body, and strength. These fibers can be used alone or in admixture of two or more at an appropriate ratio.

  The outer layer container 3 may contain additives for outer layers such as a dispersant, a pigment, a fixing agent, an antifungal agent, a sizing agent, an adhesive, and a paper strength enhancer as necessary.

The air permeability of the outer layer container 3 (value measured using a measuring device (Tokyo tester, Gurley's Desometer) in accordance with JIS P81170-1980 with the smooth side set to the upper side of the device) is the surface smoothness. In view of the above, it is preferably 30 to 120 seconds, more preferably 65 to 120 seconds, and further preferably 70 to 100 seconds.
Further, the air permeability of the outer layer container is preferably larger than that of the inner layer container. By making the air permeability of the outer layer container larger than that of the inner layer container, when the coating layer is brought into close contact by vacuum forming as will be described later, the outer layer container has a ventilation resistance and is provided in the vacuum forming mold. Concentration of local suction force in the suction groove can be prevented, pinholes in the resin film can be prevented, and coating without unevenness of adhesion can be achieved.

  The inner dimension of the outer layer container 3 is smaller than the outer dimension of the inner layer container 3, and in the state where both are combined, the outer surface of the outer layer container having low rigidity is almost the outer dimension of the outer layer container. Does not deform. For this reason, in line conveyance etc., the container on the line flows smoothly without stagnation, and the outer layer container does not curve, so that the printability is excellent. Further, when the coating layer is brought into close contact by vacuum molding as will be described later, the inner layer and the outer layer are integrated, so that the occurrence of inner layer cracking due to vacuum pressure is prevented.

In the composite container 1, the inner layer container 2 and the outer layer container 3 are united by fitting. Here, the term “fitting” means that when the inner layer container 2 and the outer layer container 3 are combined, a stress such as compression or pulling occurs between them, and a contact force is generated between the inner layer container 2 and the outer layer container 3. The state that has occurred. As described above, the inner layer container 2 and the outer layer container 3 are provided in such a form that the outer surface of the inner layer container has low density irregularities, and the inner surface of the outer layer container is rigid and preferably has a coarse, preferably mesh-like back. Therefore, in the fitted state, the outer surface of the inner layer container bites into the inner surface of the outer layer container. For this reason, a friction coefficient becomes high and it is in the state which the inner-layer container 2 and the outer-layer container 3 become difficult to isolate | separate, and an adhesive agent is not especially required for these joining. For this reason, the production cost can be kept low and the manufacturing equipment can be simplified.
Also, here, if the inner surface of the inner layer is provided with circumferential slits and suction round hole projections for escape of steam at the time of drying, the contents are caught by the projections during eating and drinking, and this is left uneaten. There's a problem. In addition, the resin film covering the convex portion may be damaged by scratching with a chopstick or a spoon. Therefore, by providing a slit at the time of drying in the height direction on the inner surface of the inner layer, a container that is less likely to catch chopsticks and spoons, less likely to catch contents, and easy to eat and drink is manufactured. Furthermore, in the case of coating with a resin film by vacuum forming, the film is pasted from the cup mouth portion toward the bottom, but in the presence of the round hole shape or circumferential convex portion, the film of the convex portion On the downstream side in the direction in which the film is pasted, the film stretches greatly, and the phenomenon that the film becomes thin occurs, and pinholes are easily generated in the film. However, since the direction in which the film is pasted and the direction in which the slit protrusions are formed coincide with each other by using the longitudinal slit, such a phenomenon does not occur and pinholes are less likely to occur.

  The thickness of the coating layer 4 is 0.02 to 0.15 mm, particularly 0.03 to 0.03 in consideration of barrier properties such as water vapor, prevention of pinholes, material costs, and prevention of tearing by scratching with a spoon or chopsticks. It is preferable to set it as 0.01 mm.

  A resin film is preferably used for the covering layer 4. Examples of the resin film include thermoplastic resins such as polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon, polyvinyl resins such as polyvinyl chloride, and styrene resins such as polystyrene. Examples thereof include biodegradable resin films such as films, modified polyethylene terephthalate, and aliphatic polyesters. Among these, polyolefin resins are preferable in terms of production cost, moldability, and the like, and biodegradable resin films and biomass-derived resin films are preferable in terms of environment. These resin films can be used alone or in a laminate of two or more for the coating layer 4.

In the heat insulating composite container 1, the flange portion 11 has a thickness (total layer thickness) T <b> 11, a thickness in the vicinity of the mouth portion of the trunk portion 12 (total layer thickness) T <b> 121, and a central portion thickness (total layer thickness). The thickness (total layer thickness) T14) of T122 and the bottom 14 is preferably T11 >>T121>T122> T14.
Further, the density ρ21 of the flange portion 21 of the inner layer container 2, the density ρ221 of the body portion 22 of the inner layer container 2, the density ρ222 of the body portion 22 of the inner layer container 2, the density ρ24 of the bottom portion 24 of the inner layer container 2 is ρ221> ρ222 It is preferable that ρ21> ρ222 and ρ24> ρ222.
Furthermore, the thickness T31, the thickness T321, and the thickness T322 of the flange portion 31 of the outer layer container 3 are preferably T321> T322 and T31> T322, and more preferably T31>T321> T322.
By setting the relationship between the thicknesses of the respective parts of the heat insulating composite container 1, the relationship between the densities of the respective parts of the inner layer container 2, and the relationship between the thicknesses of the respective parts of the outer layer container 3, the following effects can be obtained.
The heat insulating composite container 1 obtained by increasing the density of the flange portion 21 of the inner layer container 2 constituting the flange portion 11 and increasing the thickness of the flange portion 31 of the outer layer container 3 and increasing the thickness of the flange portion 11. The grip strength can be increased. Further, by increasing the thicknesses T121 and T321 near the mouth and increasing the density ρ221, the gripping strength and buckling strength of the heat insulating composite container 1 obtained can be increased. By increasing the inner layer density of the bottom 24 of the inner layer container 2 constituting the bottom 14 and reducing the thickness T14, buckling due to a compressive load in the vertical direction and cracking of the inner layer during vacuum forming can be prevented. In particular, by reducing the thickness of the trunk portion T122 that requires heat insulation and reducing the inner layer density ρ222, it is possible to realize thinness and lightness.

The heat insulating composite container 1 preferably has a radius of curvature Ro of the outer corner portion of the bottom portion 14 of 5 mm or less, particularly preferably 0 to 3 mm, and a grounding width W14 of the grounding portion 142 of the bottom portion 14 is 1 to 20 mm, particularly 2 to 2. The height H14 of the raised bottom portion 141 of the bottom portion 14 is preferably 0.5 to 5 mm, particularly preferably 1 to 3 mm.
By setting the radius of curvature within such a range, sufficient strength can be secured in terms of shape. By setting the ground contact width 14 in such a range, a ground contact area that receives a vertical compression load can be sufficiently secured. By setting the height H14 of the raised bottom portion 141 within such a range, the content of the inner surface corner portion does not enter without narrowing the inner volume of the container. In addition, the shape can be satisfactorily transferred by the male mold made of an elastic material described later on the corner portion having the radius of curvature and the bottom portion 14 having the contact width. Moreover, when the heat insulation composite container 1 is packaged with a packaging material such as a shrink film, the packaging material can be easily broken. Furthermore, by setting the curvature radius Ro, the ground contact width W14, and the height H14 of the raised bottom portion 141 within such ranges, as a synergistic effect thereof, sufficient strength in shape of the heat insulating composite container 1 with respect to the compressive load in the vertical direction can be obtained. can get.

  From the viewpoint of making the shape of the heat insulating composite container 1 so that the bottom corner portion is the thinnest and the thickness of the trunk portion is thinned from the stacking step to the bottom side to prevent the occurrence of cracks in the inner layer due to vacuum forming. The curvature radius Ro of the outer corner of the bottom portion 14 and the curvature radius Ri of the inner corner are preferably 0 ≦ Ro ≦ 5 mm and Ro−0.5 mm <Ri <Ro + 1 mm (where Ro is 0). Ri is 0 when .about.0.5). In addition, 0 <= Ro <= 3mm is preferable from a viewpoint of the intensity | strength improvement of the heat insulation container with respect to a longitudinal compression load.

Next, a method for manufacturing the heat insulating composite container 1 will be described.
The heat insulating composite container 1 is manufactured by individually preparing the inner layer container 2 and the outer layer container 3, combining them, and further covering with the coating layer 4.

  As shown in FIGS. 2 (a) to (f), the inner layer container 2 and the outer layer container 3 make the papermaking bodies 2 ′ and 3 ′ which are intermediates by a wet papermaking method using the papermaking molds 200 and 300, It is manufactured by molding with a dry mold 600,700.

  As shown in FIG. 2A, the papermaking portion 210 of the papermaking mold 200 has a flange portion 211 and has a predetermined taper angle and tapers toward the tip portion.

  The papermaking section 210 is composed of a thin mold in which a porous plate is bent and welded, and a net (not shown) in which a metal net placed thereon is bent and welded. The papermaking section 310 is also composed of a thin-walled mold obtained by bending and welding a plate with many f holes, and a net obtained by bending and welding a metal net placed thereon.

  A dry mold 600 for dry-molding the papermaking body 2 ′ includes a male mold 610 and a female mold 620 as shown in FIG. The male mold 610 and the female mold 620 are metal molds such as a rigid aluminum alloy.

  The male mold 610 has a convex shaped portion 611 corresponding to the inner surface shape of the inner layer container 2. A thin molded portion 612 having a reduced diameter corresponding to the stacking step 23 of the inner layer container 2 is provided at the tip of the molded portion 611.

  Inside the molding part 611, there are a plurality of gas-liquid flow passages 614 that are separated from the gas-liquid flow passage 613 and the gas-liquid flow passage 613 and are opened in the height direction on the outer peripheral surface, and the bottom surface in the circumferential direction. A plurality of slit-shaped airflow passages (not shown) opened in an arc shape are provided, and dewatering and exhausting are performed when the papermaking body 2 'is dried through these gas-liquid flow passages. Further, a cartridge heater (not shown) is disposed inside the molding unit 611 so that heating can be performed from the outer surface of the molding unit 611.

  The female mold 620 has a concave molded portion 621 corresponding to the outer shape of the inner layer container 2. A cartridge heater 622 is disposed inside the female mold 620. Further, the female mold 620 is provided so that a predetermined clearance is formed between the convex portion of the molded part 611 and the molded part 621 when combined with the male mold 610. Although not shown in the drawing, the female die 620 is provided with a slit in the circumferential direction on the body and a slit on an arc at the bottom for shortening the drying time and sucking and holding the papermaking body 2.

The male mold 710 is made of an elastic body such as natural rubber or synthetic rubber such as silicone rubber from the viewpoint of durability. A fluid-permeable stretchable net is coated on the outside of the elastic body.
A plurality of gas-liquid flow passages 714 that are separated from the gas-liquid flow passage 713 and are connected to the outer peripheral surface and a plurality of gas-liquid flow passages 715 that are open at the front end surface and corners are provided inside the molding portion 711. When the papermaking body 3 ′ is dried through the gas-liquid flow passage, dehydration and exhaust are performed.

  The female die 720 has a concave shaped portion 721 corresponding to the outer shape of the outer layer container 3. A cartridge heater 722 is disposed inside the female mold 720. The female mold 720 is preferably one that does not have an exhaust hole that opens on the inner surface of the molding portion 721 so as not to leave behind on the outer surface of the inner layer container 3. For the suction holding, a slit in the circumferential direction can be provided in the body portion, and a slit on an arc can be provided in the bottom portion.

  When papermaking body 2 ′ and papermaking body 3 ′ are made, as shown in FIGS. 2 (a) and 2 (d), gas-liquid circulation is provided in the gas-liquid flow passages provided in papermaking sections 210 and 310. The tubes 220 and 320 are connected. And after arranging the raw material slurry injection pipes 230 and 330 so as to surround the papermaking sections 210 and 310 of the papermaking molds 200 and 300, the valves of the slurry supply pipes 231 and 331 attached to the injection pipes 230 and 330 are opened, After supplying predetermined slurry to the papermaking sections 210 and 310, the gas-liquid circulation pipes 220 and 320 are opened, and the liquid component in the raw material slurry is sucked through the gas-liquid circulation pipes 220 and 320 and the gas-liquid flow passage. The solid content in the raw material slurry is deposited on the net. When the discharge by the suction of the liquid component is completed and the papermaking bodies 2 'and 3' are formed on the surface of the papermaking net, the injection pipes 230 and 330 are retracted. Moreover, after arranging the injection pipes 230 and 330, a predetermined amount of water can be supplied, and then the slurry can be charged. Thereby, it can prevent that the pulp fiber in a slurry is entangled in a metal net | network, and can make mold release from the net | network of a papermaking body easy. Also, by reducing the slurry concentration in the injection tube, it is possible to obtain a papermaking body with less unevenness in papermaking without increasing the equipment such as a slurry tank, and by changing the amount of water injection, The amount of pulp in the height direction can be changed.

  As a raw material slurry used for papermaking of the papermaking body 2 ', it is preferable to use a slurry having a pulp fiber concentration of 0.1 to 2.0 wt%. Although there is no restriction | limiting in particular in a dispersion medium, It is preferable to use water or white water as a dispersion medium from the point of handleability and production cost. In addition, the raw material slurry may contain the inner layer additive at an appropriate ratio, if necessary.

It is preferable that the raw material slurry used for papermaking of the papermaking body 2 ′ contains 0.01 to 0.5 wt% of a dispersant with respect to the pulp component. If the dispersant is 0.01 wt% or more, a dispersion effect is sufficiently obtained, and if it is 0.5 wt% or less, papermaking can be performed without requiring a long time, and contamination of the papermaking net and the mold itself can be suppressed.
Examples of the dispersant include various surfactants, polyethylene oxide or a derivative thereof, and among these, polyethylene oxide is preferable from the viewpoint of less foaming and easy handling of the slurry.

  As a raw material slurry used for papermaking of the papermaking body 3 ', it is preferable to use a slurry having a pulp fiber concentration of 0.1 to 2.0 wt%. Although there is no restriction | limiting in particular in a dispersion medium, It is preferable to use water or white water as a dispersion medium from the point of handleability and production cost. In addition, the outer layer additive may be included in the slurry at an appropriate ratio, if necessary.

Next, the papermaking bodies 2 ′ and 3 ′ are dry-molded with dry dies 600 and 700.
As shown in FIGS. 2B and 2E, the papermaking bodies 2 ′ and 3 ′ are placed in the drying dies 600 and 700 heated by the heater and press-molded while drying. The moisture content of the papermaking bodies 2 ′ and 3 ′ at this time is preferably 55 to 80%, particularly 60 to 75% from the viewpoints of shortening the drying time, smoothness of the surface, and prevention of scorching and discoloration.

  When the papermaking bodies 2 ′ and 3 ′ are dried, the liquid (vapor) of the papermaking bodies 2 ′ and 3 ′ is sucked through the gas-liquid passages of the male molds 610 and 710 and discharged to the outside.

  The mold temperature during drying of the papermaking bodies 2 'and 3' is preferably 110 to 250 ° C, particularly 120 to 230 ° C in consideration of prevention of scorching due to drying, drying efficiency, surface smoothness, and the like. After the papermaking bodies 2 ′ and 3 ′ are dried, the male molds 610 and 710 are withdrawn from the papermaking molds 600 and 700, and the papermaking bodies 2 ′ and 3 ′ are taken out from the male molds (see FIGS. 2C and 2F). . Then, as shown in FIG. 2 (g), the inner layer container 2 is fitted into the outer layer container 3 so as to be combined, and after trimming of the excess portion of the flange portion, the container main body 100 is formed and the covering layer 4 is formed.

  An adhesive may be used for joining the inner layer container 2 and the outer layer container 3 to increase the adhesive strength as necessary. As the adhesive, it is preferable to use a natural adhesive such as starch or carboxymethylcellulose, or a synthetic water-soluble adhesive such as PVA.

Next, the coating layer 4 is formed from the inner surface of the inner layer container 2 to the lower side of the flange portion 31 of the outer layer container 3 on the container body 100 in which the inner layer container 2 and the outer layer container 3 are overlapped. When this coating layer 4 is formed, the thickness of all layers in the portion below the stacking step is made thinner than the thickness of the top of the stacking step. In order to reduce the thickness of the entire layer in the portion, it is preferable to reduce the thickness of the inner layer.
The covering layer 4 can be formed by a conventional method such as vacuum forming using a resin film, pressure forming, or the like. In the case of vacuum forming, for example, as shown in FIG. 3, a vacuum forming die 800 having a vacuum suction path 810 and a band heater 820, and a plug 900 having a heater are used. The vacuum forming die 800 is provided with a predetermined clearance between a portion 811 facing the lower surface of the flange 101 of the container body 100 and the flange portion 101, and a suction port for the vacuum suction path 810 is also provided in the portion 811. Keep it.

  Then, the container body 100 is set in the vacuum mold 800, and the resin film 40 is set so as to close the opening of the container body 100. Further, the plug 900 heated from above is brought into contact with the resin film 40, the resin film 40 is pushed into the vacuum mold 800, and the inside of the container main body 100 is passed through the vacuum suction path 810 using the air permeability of the container main body 100. The resin film 40 is brought into close contact with the inner surface of the container body 100 by evacuation.

  At this time, the resin film 40 that has been softened by heating in advance is rolled up to the lower surface of the flange portion 101 of the container body 100 and is brought into close contact therewith. Then, unnecessary portions of the resin film 40 are trimmed to complete the formation of the coating layer 4.

  The heat insulating composite container 1 of the present embodiment thus obtained has heat insulating properties and light weight, and is coated with a resin film without causing surface defects, and preferred forms thereof are heat insulating properties and structural strength. It is an excellent thin and lightweight container that satisfies various high performances such as surface properties, moldability, disposal properties, and storage stability of contents.

  The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.

  In the above embodiment, the paper making and drying steps are used. However, the paper making bodies 2 'and 3' may be made, then dehydrated in a dewatering type, and then dried in a dry type. Moreover, the direction of the papermaking mold, the dewatering mold, and the drying mold used in the manufacturing process can be changed as appropriate. The mold may be split or split in consideration of handling properties, mold workability, assembly performance, maintainability, and the like.

  Hereinafter, the present invention will be described more specifically with reference to examples.

[Example 1]
A heat insulating composite container having the form shown in FIG. 1 and having the following dimensions was produced as follows. The weight of the obtained container is 20.6 g

<Insulated composite container dimensions>
Height H: 106mm
Mouth inner diameter φ10: 90mm
Curvature radius of opening edge of mouth R10: 1mm
Flange thickness T12: 2mm
Flange outer diameter φ11: 96mm
Stacking step: position 22.28 mm from bottom Body thickness T121: 1.69 mm (position 100 mm from bottom)
Body thickness T122: 1.36 mm (position 40 mm from the bottom)
Body thickness T123: 1.87 mm (position 15 mm from the bottom)
Body thickness T124: 1.61 mm (position 5 mm from the bottom)
Body taper angle θ1: 6.5 degrees Body taper angle θ2: 4 degrees Bottom thickness T14: 0.95 mm
Bottom outer diameter φ14: 68.5mm
Raised bottom height H14: 3mm
Raised bottom outer diameter φ141: 40mm
Inner diameter of bottom contact surface φ142: 55mm
Corner radius of curvature Ro: 2 mm
Corner radius of curvature Ri: 2 mm

<Making of inner layer container and outer layer container>
First, water is injected as shown in FIGS. 2 (a) and 2 (e) using a papermaking mold in which a perforated plate is bent and a metal net is welded and processed on the surface of the mold that has been welded into a male shape. Thereafter, the following raw material slurry was supplied to form a wet papermaking.
Raw material slurry for inner layer;
Formulation: (pulp fiber (HBA (warehauser)) / pulp for outer layer = 5/5 (weight ratio), CSF = 720 ml), pulp fiber concentration in pulp slurry is 0.5% by weight, concentration after adding water Is 0.25 wt%)
Sizing agent: 2% by weight of pulp
Raw material slurry for outer layer;
Formulation: (pulp fiber (trade name Hinton / trade name CENIBRA = 3/7 (weight ratio), CSF = 450 ml), pulp fiber concentration in the pulp slurry is 0.5% by weight, and the concentration after adding water is 0.25 weight%)
Sizing agent (2% by weight of pulp)

As shown in FIG. 2 (b), the obtained papermaking product was placed in a dry mold and dried under the following conditions.
Mold (620) temperature: 200 ° C, mold (610) temperature 200 ° C, drying time 25 seconds.
As shown in FIG. 2 (e), the obtained papermaking product was placed in a dry mold and dried under the following conditions.
Mold (720) temperature: 170 ° C
Pressing force: 9800N (pressing continues for 50 seconds)

<Formation of coating layer>
After the inner layer container and the outer layer container were combined, the following resin film was placed in contact with the inner layer container and laminated under the following molding conditions.
Resin film;
Outer layer / inner layer = high density polyethylene / low density polyethylene Resin film total thickness: 200 μm (before molding)
Molding condition;
Vacuum forming machine: PLAVAC-FE36PHS, manufactured by Sanwa Kogyo Co., Ltd. Film heating method: Infrared heater (space between heater and resin film 110 mm)
Film heating temperature: 300 ° C (molding machine display temperature)
Film heating time: 26 seconds Plug dimensions: Diameter 60 mm x length 110 mm
Plug material: Aluminum alloy (Fluoro resin processing on the surface)
Plug temperature: 110 ° C (plug actual surface temperature)
Mold temperature for vacuum forming: 110 ° C (actual surface temperature inside the mold)
Molding time: 10 seconds

[Comparative Example 1]
A heat-insulating composite container was produced in the same manner as in Example 1 except that the dimensions and shapes were changed with respect to the following points. The weight of the obtained container was 20.3 g.
Body thickness T122: 1.54 mm (position 40 mm from the bottom)
Body thickness T123: 2.27 mm (position 15 mm from the bottom)
Body thickness T124: 2.38 mm (position 5 mm from the bottom)
Body taper angle θ1: 6.5 degrees Body taper angle θ2: 6.5 degrees Bottom thickness T14: 1.43 mm
Corner radius of curvature Ro: 2 mm
Corner radius of curvature Ri: 3 mm

(Comparative Example 2)
A heat insulating container was produced in the same manner as in Example 1 except that the dimensional shape was changed with respect to the following points.
Body taper angle θ1: 6.5 degrees Body taper angle θ2: 3 degrees Corner radius of curvature Ro: 2 mm
Corner radius of curvature Ri: 1.5mm

[Measurement of total thickness and thickness of each layer]
Using a thickness meter (manufactured by Nippon Parametrics Co., Ltd., Magnamic, Model 8000), measure the total thickness of each part of the heat-insulated composite container using a target ball diameter of 1/8 inch, and use a punch with an inner diameter of 4 mm. A sample of each part was taken out from the heat insulating composite container, and the thickness of the outer layer was measured with the same measurement meter. Furthermore, the coating layer was peeled off from the inner layer, and the thickness of the coating layer was measured with the same measuring instrument. The thickness of the inner layer was determined by subtracting the thickness of the outer layer and the coating layer from the total thickness. The measured value was an average value at four locations in the circumferential direction. The thicknesses of the inner layer and the outer layer of the flange portion were measured using those before cutting the burr of the flange portion. The total thickness of the flange portion was set to the size of the front end portion of the flange by calipers. In Table 1, among the measurement results for Example 1 and Comparative Example 1, the thickness of the whole body layer, the inner layer and the outer layer at 5 mm, 15 mm and 40 mm from the bottom, and the thickness of the whole layer, the inner layer and the outer layer at the bottom part Is shown.

[Measurement of density of each layer]
The density of each layer was calculated based on the thickness, the area of the cut sample, and its weight.

(Evaluation of thermal insulation properties)
A temperature sensor (Anritsu 503K-TC-WT) measuring unit is attached to the outer surface of the heat insulating composite container with aluminum tape, and hot water of 98 to 100 ° C. is poured into the heat insulating composite container, and the temperature of the outer surface of the container after 1 minute is measured. It was measured.

  As shown in Table 1, the heat-insulating composite container obtained in Example 1 is substantially the same as the heat-insulating composite container obtained in Comparative Example 1, but the inner surface is good with a resin film. It was coated. In Comparative Example 2, the molded product could not be released from the core (papermaking mold) after molding.

  There is no restriction | limiting in particular in the use of the heat insulation composite container of this invention, and there is no restriction | limiting in particular also in the content accommodated. Examples of the use of the sealed container include, in addition to the instant cup noodles of the above embodiment, instant foods other than noodles, various foods and foods such as ice cream and confectionery, seasonings, chemicals, cosmetics, detergents, etc. Examples of the storage container include a container in which an article is attached separately from the contents stored in the container main body.

It is a figure which shows typically one Embodiment which applied the heat insulation composite container of this invention to the food container, (a) is a half sectional view, (b) is an enlarged view of the part of (a), (c). (A) is an enlarged view of a portion B, (d) is an enlarged view of a portion C of (a), and (e) is an enlarged view of the vicinity of a stacking step. It is a figure which shows typically the manufacturing process of the heat insulation composite container of the embodiment, (a) is a figure which shows the papermaking process of the papermaking body for inner-layer containers, (b) is the dry molding process of the papermaking body for inner-layer containers. (C) is a diagram showing an inner layer container, (d) is a diagram showing a paper making process of a paper product for an outer layer container, (e) is a diagram showing a dry molding process of the paper product for the outer layer container, (f) is a figure which shows the papermaking body for outer layer containers, (g) is a figure which shows the state which united the inner layer container and the outer layer container. It is a figure which shows typically the formation process of the coating layer in the manufacturing process of the heat insulation composite container of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat insulation composite container 10 Mouth part 11 Flange part 110 Upper surface part 12 Trunk part 13 Level | step difference 14 Bottom part 2 Inner layer container (inner layer)
3 Outer container (outer layer)
4 Coating layer 800 Vacuum forming die 900 Plug

Claims (6)

A heat-insulating composite container comprising an inner layer containing bulky treated pulp, and an outer layer having pulp as a main component and a higher density than the inner layer,
A heat insulating composite container having a stacking step in the body portion, wherein the body portion in a lower part of the stacking step is provided thinner than a thickness of an ascending portion of the stacking step.   2. The heat insulating composite container according to claim 1, wherein a thickness of the inner layer in the trunk portion below the stacking step is provided thinner than a thickness of the inner layer in the top portion of the stacking step.   3. The heat insulating composite container according to claim 1, wherein a taper angle of an inner surface of the barrel portion below the stacking step is smaller than a taper angle of an outer surface of the barrel portion.   The heat insulation composite container of Claim 1 or 2 provided so that the thickness of a bottom part may become thinner than the thickness of this trunk | drum above the stack part level | step difference of the said trunk | drum. The radius of curvature Ro of the outer corner of the bottom and the radius of curvature Ri of the inner corner are
0 ≦ Ro ≦ 5 mm and Ro−0.5 mm <Ri <Ro + 1 mm (However, when Ro is 0 to 0.5, Ri is 0)
The heat insulating composite container according to claim 1 or 2. The heat insulation composite container in any one of Claims 1-5 provided with the coating layer on the surface of the said inner layer.

Images