Insulated containers and packaging paper for insulated containers

Abstract

To make a paper-made heat insulation vessel water-resistant.SOLUTION: A heat insulation vessel 1 comprises: a paper-made vessel body which comprises a cylindrical trunk part 12 and a bottom part 13 closing a reverse surface of the trunk part 12; and a cylindrical paper-made exterior sleeve 14 which is fixed covering the trunk part 12 so that a heat insulation space D is formed outside the trunk part 12 of the vessel body, and has an inward curl part 14A at a lower-end peripheral edge part. The exterior sleeve 14 is made of synthetic paper formed by agglutinating and intertwining vegetable fiber and polyethylene fiber together, to include the vegetable fiber by a 50 to 85% weight ratio, and the polyethylene fiber for the rest.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermally insulated container and packaging paper for the thermally insulated container. [Background technology]

[0002] Insulated containers generally consist of a container body with a body and a bottom, and a cylindrical outer sleeve attached to the outside of the container body, with a gap between the body of the container body and the outer sleeve providing thermal insulation. In recent years, insulated containers made of paper have become mainstream instead of plastic ones in order to reduce carbon dioxide emissions during incineration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-324538

[0004] Paper containers are prone to stains and tears when wet. Condensation is likely to occur when the product is distributed frozen, and the same applies if condensation does occur. Summary of the Invention [Problem to be solved by the invention]

[0005] The object of this invention is to provide a paper insulated container with water resistance. [Means for solving the problem]

[0006] The insulated container of this invention comprises a paper container body having a cylindrical body and a bottom that closes the underside of the body, and a cylindrical paper outer sleeve having an inward curled portion at the lower end periphery that is placed over and fixed to the body so as to form an insulating space between the outside of the body of the container body, characterized in that the outer sleeve is made of synthetic paper made by intertwining and cementing together plant fibers and thermoplastic resin fibers, with the weight ratio of the plant fibers being more than 50% and not more than 85%, and the remainder being thermoplastic resin fibers.

[0007] The insulated container according to this invention can also be defined as follows: The insulated container according to this invention comprises a paper container body having a cylindrical body and a bottom that closes the underside of the body, and a cylindrical paper outer sleeve having an inward curled portion at the periphery of its lower end that is placed over and fixed to the body so as to form an insulating space between the outside of the body of the container body, and is characterized in that the outer sleeve is made of synthetic paper made by intertwining and agglutinating plant fibers and thermoplastic resin fibers, contains more than 50% plant fiber by weight, and has a water absorption rate of 50% or less.

[0008] Plant fibers are made from wood and other raw materials, and softwood kraft pulp, hardwood kraft pulp, and other natural pulps can be used.

[0009] The thermoplastic resin fiber is, for example, a polyolefin hyperbranched fiber made from polyethylene, and one example that can be used is one commercially available from Mitsui Chemicals, Inc. under the trade name SWP.

[0010] The water absorption rate is calculated by measuring the amount of water absorbed (g) by immersing a small piece of the outer sleeve in water, dividing the amount of water absorbed by the weight of the paper piece before immersion, and multiplying the result by 100. The higher the water absorption rate, the easier it is to absorb water, and the lower the rate, the less likely it is to absorb water, meaning it is water resistant.

[0011] The outer sleeve constituting the insulated container of this invention is classified as "paper" because it contains more than 50% vegetable fiber by weight.

[0012] The container body onto which the outer sleeve is placed is also made of paper. The container body may be made of the same synthetic paper as the outer sleeve, or it may be made of a different paperboard. For example, the container body may be made of paperboard made of plant fiber with a synthetic resin protective film coated on the inside and / or outside. The container body is also made of paper and contains more than 50% plant fiber by weight.

[0013] According to this invention, the paper outer sleeve that constitutes the insulated container is made water-resistant, so stains and tears are less likely to occur even when it gets wet. A water-resistant insulated container is provided.

[0014] The present invention also provides an exterior paper that forms an exterior sleeve used in the above-mentioned insulated container. The exterior paper according to the present invention is an exterior paper that forms a tubular exterior sleeve having an inward curled portion at the periphery of the lower end, and that is placed over and fixed to a paper container body having a tubular body and a bottom that closes the lower surface of the body so as to form an insulating space between the body and the exterior sleeve, and is made of synthetic paper made by intertwining and agglutinating plant fibers and thermoplastic resin fibers, with the weight ratio of the plant fibers being more than 50% but not more than 85%, and the remainder being thermoplastic resin fibers.

[0015] The packaging paper of this invention can also be defined as follows: That is, the packaging paper of this invention is packaging paper that forms a cylindrical packaging sleeve with an inward curled portion at the bottom periphery, which is placed over and fixed to the body of a paper container body having a cylindrical body and a bottom that closes the underside of the body so as to form an insulating space between the body and the outside of the body, and is made of synthetic paper made by intertwining and agglutinating plant fibers and thermoplastic resin fibers, and contains plant fibers at a weight ratio of more than 50% and has a moisture absorption rate of 50% or less.

[0016] To provide an exterior paper suitable for an exterior sleeve that is resistant to stains and tears even when wet with water. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a partially cutaway front view of the heat-insulating container. [Figure 2] This is a close-up photo of the outer sleeve. [Figure 3] This is a close-up photo of the outer sleeve. [Figure 4] This is a close-up photo of the outer sleeve. [Figure 5] The results of the water supply measurement test are shown. DETAILED DESCRIPTION OF THE INVENTION

[0018] FIG. 1 shows a partially cutaway front view of the heat-insulating container 1. As shown in FIG.

[0019] The insulated container 1 comprises a body 12 and a bottom 13 that constitute the container body, and an exterior sleeve 14 .

[0020] The body 12 is a truncated cone-shaped cylinder with a larger diameter at the top and a smaller diameter at the bottom, and the contents are placed in through the open top. The upper peripheral edge of the body 12 is curled outward, forming a so-called outward curled portion 12A. The bottom 13 is circular, and its peripheral edge is bent downward (bent portion 13A). The bottom 13 fits snugly into the bottom opening of the body 12, and the lower end of the body 12 is folded inward (folded portion 12B), and this folded portion 12B sandwiches the bent portion 13A of the bottom 13. The inner and outer surfaces of the bent portion 13A of the bottom 13 and the inner surface of the lower end of the body 12 that sandwiches it are glued or welded together, and the lower opening of the body 12 is tightly closed by the bottom 13.

[0021] The exterior sleeve 14 is attached to the outside of the body 12 of the container body. The exterior sleeve 14 is formed by gluing the sides of an arched exterior paper together to form a cylindrical shape. When the sides of the arched exterior paper are glued together to form a cylindrical shape, it takes on a truncated cone shape that is larger at the top and gets smaller as it goes down, just like the body 12. The lower peripheral edge of the exterior sleeve 14 is curled inward, forming an inward curl portion 14A at the lower peripheral edge of the exterior sleeve 14.

[0022] The height of the outer sleeve 14 is slightly lower than the height of the body 12. The body 12 having the bottom 13 is inserted (fitted) into the outer sleeve 14 from above. The upper end of the outer sleeve 14 fits into the gap between the outward curled portion 12A of the body 12 and the body 12, and the inward curled portion 14A at the lower peripheral edge of the outer sleeve 14 comes into contact with the outer surface of the thread end portion of the body 12. One or both of the upper end and the inward curled portion 14A of the outer sleeve 14 may be glued to the body 12 to firmly secure the outer sleeve 14 to the body 12.

[0023] An inward curled portion 14A is formed on the peripheral edge of the lower end of the outer sleeve 14, so a gap is formed between the outer sleeve 14 and the barrel 12 of the container body, and this gap becomes an insulating space D between the outer surface of the barrel 12 and the inner surface of the outer sleeve 14. The heat of hot water poured into the container body is not directly transferred to the hand, making it easy to hold.

[0024] The container body (body 12 and bottom 13) is made of paper, and its inner and / or outer surfaces are coated with a protective film (resin film, resin film, etc.) as needed. Specific examples of protective films include polyethylene (PE), polypropylene (PP), polyester, and ethylene-vinyl acetate copolymer. These can also be used for bonding by heat sealing.

[0025] On the other hand, the outer sleeve 14 is made of a synthetic material that is mainly composed of paper (plant fiber) (typically pulp fiber) (over 50% by weight) mixed with polyolefin hyperbranched fiber, such as polyethylene (PE) fiber. Polyethylene fiber is a type of thermoplastic resin fiber that softens when heated and is water-resistant (water absorption rate is close to zero).

[0026] Figures 2 to 4 are enlarged photographs of the outer sleeve 14. Figure 2 shows one in which the weight ratio of polyethylene fiber to pulp fiber is 15:85, Figure 3 shows one in which the weight ratio of polyethylene fiber to pulp fiber is 30:70, and Figure 4 shows one in which the weight ratio of polyethylene fiber to pulp fiber is 49:51.

[0027] As can be seen from the enlarged photograph, the outer sleeve 14 is not made of paper laminated with polyethylene (paper coated on the inner / outer surfaces with polyethylene), but is made of synthetic paper made by intertwining and gluing together the plant fibers that make up the paper (pulp fibers in the examples of Figures 2 to 4) and thermoplastic resin fibers (polyethylene fibers in the examples of Figures 2 to 4).

[0028] Figure 5 shows the results of the water supply measurement test.

[0029] In the water absorption measurement test, 5 cm square pieces of paper (coated cardboard) containing only pulp fiber (Comparative Example 1), 5 cm square pieces of synthetic paper with a weight ratio of polyethylene fiber to pulp fiber of 15:85 (Example 1), 5 cm square pieces of synthetic paper with a weight ratio of polyethylene fiber to pulp fiber of 30:70 (Example 2), and 5 cm square pieces of synthetic paper with a weight ratio of polyethylene fiber to pulp fiber of 49:51 (Example 3) were prepared, and their weights (before immersion) and after immersion in water for 3 minutes (after immersion) were measured. In Figure 5, the water absorption amount (g) is shown as the weight after immersion minus the weight before immersion. Water absorption amount (g / m 2 ) is the amount of water supplied per unit area (water supply amount (g) is the area of ​​a 5cm square piece of paper (0.0025m 2 The water absorption rate (%) is the amount of water absorbed (g) divided by the weight (g) of the paper piece before immersion and multiplied by 100.

[0030] Coated cardboard that does not contain polyethylene fibers absorbs a lot of water (Comparative Example 1). In contrast, the absorption amount and water absorption rate of synthetic paper that contains polyethylene fibers are significantly lower than those of coated cardboard (Examples 1 to 3).

[0031] When the pulp fiber and polyethylene fiber were mixed in roughly equal amounts (Example 3), the amount of water absorbed was reduced to the point where almost no water was absorbed (below the measurement limit; shown as "N / A" in Figure 5). The outer sleeve with a weight ratio of polyethylene fiber to pulp fiber of 49:51 is mostly pulp fiber, so it can be classified as "paper" and has excellent water resistance.

[0032] If the weight ratio of polyethylene fiber is too small, the water absorption rate approaches that of coated cardboard, making it more susceptible to staining and tearing when wet. When about 15% polyethylene fiber is mixed (Example 1), the water absorption rate becomes 50%, which significantly improves water resistance compared to coated cardboard, making it less susceptible to staining and tearing when wet. If the polyethylene fiber content is less than 15%, the pieces of paper soaked in water lose stiffness over time, become more susceptible to water penetration, and are more susceptible to staining. It is appropriate for the weight ratio of polyethylene fiber to be 15% or more (i.e., the weight ratio of pulp fiber to be 85% or less). [Explanation of symbols]

[0033] 1. Insulated container 12 Torso 13 Bottom 14 Exterior sleeve 14A Inward curl D. Insulated space

Claims

1. The container comprises a paper container body having a cylindrical body and a bottom that closes the lower surface of the body, and a cylindrical paper outer sleeve having an inward curled portion at the bottom edge that is placed over and fixed to the body so as to form an insulating space between the outside of the body of the container body and the sleeve, the outer sleeve is made of synthetic paper of plant fibers and polyethylene hyperbranched fibers, and the plant fibers and the polyethylene hyperbranched fibers are entangled and glued together in the synthetic paper; The weight ratio of the plant fiber is more than 50% and not more than 85%, and the remainder is polyethylene hyperbranched fiber. Insulated container.

2. The container comprises a paper container body having a cylindrical body and a bottom that closes the lower surface of the body, and a cylindrical paper outer sleeve having an inward curled portion at the bottom edge that is placed over and fixed to the body so as to form an insulating space between the outside of the body of the container body and the sleeve, the outer sleeve is made of synthetic paper of plant fibers and polyethylene hyperbranched fibers, and the plant fibers and the polyethylene hyperbranched fibers are entangled and glued together in the synthetic paper; Contains more than 50% vegetable fiber by weight and has a water content of 50% or less. Insulated container.

3. An outer packaging paper forming a cylindrical outer sleeve having an inward curled portion at a lower end peripheral edge is placed over and fixed to a paper container body having a cylindrical body and a bottom portion closing the lower surface of the body so as to form an insulating space between the body and the outside of the body, The paper is made of synthetic paper of plant fibers and polyethylene hyperbranched fibers, and the plant fibers and the polyethylene hyperbranched fibers are entangled and glued together in the synthetic paper, The weight ratio of the plant fiber is more than 50% and not more than 85%, and the remainder is polyethylene hyperbranched fiber. Outer packaging paper for insulating containers.

4. An outer packaging paper forming a cylindrical outer sleeve having an inward curled portion at a lower end peripheral edge is placed over and fixed to a paper container body having a cylindrical body and a bottom portion closing the lower surface of the body so as to form an insulating space between the body and the outside of the body, The paper is made of synthetic paper of plant fibers and polyethylene hyperbranched fibers, and the plant fibers and the polyethylene hyperbranched fibers are entangled and glued together in the synthetic paper, Contains more than 50% vegetable fiber by weight and has a water content of 50% or less. Outer packaging paper for insulating containers.

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