JP2002114265A - Separable container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container in which a plurality of accommodating portions can easily be separated from each other and a method for producing the container. SOLUTION: A container 1 having the plurality of recesses 2 is formed from a sheet containing an amorphous resin (A) and a thermoplastic resin (B), which is incompatible with the constituent (A), at an (A)/(B) ratio of 10/90 to 90/10 (weight ratio). The recesses are tightly sealed under heat with a top film 5 made from the constituent (A) or (B). Thereafter, a score 4 is formed between the adjacent recesses along the sheet flow direction. Thus, the container in which the adjacent recesses can be separated from each other is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container capable of accommodating a plurality of foods and the like and capable of easily dividing the contents, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Cooked foods are often air-tightly packaged by filling with gas. However, once opened, there is a risk of oxidative deterioration and contamination of various bacteria. Therefore, it is required to eat as soon as possible after opening. However, in recent years, aging and nuclear families have progressed, and it is rare to eat food after opening. Therefore, there is a growing need to consume food little by little and to store the rest in a hygienic manner. Therefore, for example, in order to eliminate food leftovers, a packaging form in which the top film is reduced to a small size, or a packaging form in which the top film is opened by a small amount in a container with a top film and eaten by a small amount is used. .

In the case of the above-mentioned container with a top film, usually, a plurality of containers are further peel-wrapped with a barrier film or the like or stored in a paper box. These multiple containers
Usually, from the viewpoint of productivity, a plurality of containers are connected via perforations or cut lines, instead of being peeled and stored in a paper box in a separated form. That is, perforations and cut lines are introduced between a plurality of concave portions (cavities) formed from one sheet.
In the container having such a structure, a portion which has been consumed and becomes unnecessary is cut off using the perforations or scissors. As the base sheet constituting the container,
Polypropylene excellent in oil resistance is generally used, but in the case of polypropylene, it is difficult to separate even if a perforation is provided due to its hinge characteristics, and it cannot be easily divided.

Japanese Patent Application Laid-Open No. Hei 9-111060 discloses that a polyolefin-based film composed of 60 to 95% by weight of a polyolefin resin and 40 to 5% by weight of an incompatible thermoplastic resin is suitable for an easily tearable packaging material. ing. However, since the polyolefin-based resin composition has a high polyolefin content and low rigidity, it is difficult to mold a container and cannot be easily divided.

[0005] Polystyrene resins have high rigidity, good thermal stability and fluidity during melting, and excellent moldability. Furthermore, a container formed of a polystyrene resin can be easily divided by hand by cutting a part of the container. Therefore, polystyrene resin
Utilizing its properties, milk potions and confectionery containers
Used as a material for containers with top film.
On the other hand, since the polystyrene resin is inferior in heat resistance and oil resistance, when a polystyrene resin container containing cooked foods and the like (especially foods containing oils and fats) is directly heated by a microwave oven or the like, the container is deformed. Therefore, in order to improve such disadvantages of the polystyrene resin, a container in which a polystyrene resin container is covered with a polyolefin resin sheet having high heat resistance and oil resistance is generally used. But,
Even if cuts or perforations are provided in this container, it cannot be easily divided because the polyolefin resin layer is present.

In Japanese Patent Publication No. 62-8306,
Heat sealing a lid made of polyolefin resin to the inner layer edge of a container made of a sheet having an inner layer made of polyolefin resin and polystyrene resin and an outer layer made of polystyrene resin. A tightly sealed easy-open container is disclosed. However, in this container, since the outer layer is made of a polystyrene resin, the heat resistance and oil resistance are not sufficient, and the container cannot be easily divided even if cuts or perforations are provided due to the presence of the polyolefin resin layer.

[0007]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a container which can easily divide a plurality of storage portions, and a method of manufacturing the same.

It is another object of the present invention to provide a container which can easily divide a plurality of storage portions and has excellent heat resistance and oil resistance, and a method of manufacturing the same.

It is still another object of the present invention to provide a container capable of easily dividing a plurality of storage portions and easily sealing the storage portions, and a method of manufacturing the same.

Another object of the present invention is to provide a sheet which can easily form a container into which a plurality of storage sections can be divided.

[0011]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, have formed cuts between adjacent recesses along the sheet flow direction, thereby forming a plurality of storage portions. The present inventors have found that a container can be obtained which can be easily divided, and completed the present invention.

That is, the container of the present invention is a container having a plurality of concave portions, and cuts for dividing adjacent concave portions are formed between adjacent concave portions along the sheet flow direction. In the container, the depth of the cut is about 5 to 70% with respect to the thickness of the sheet. The cross-sectional shape of the cut is linear, V-shaped, U-shaped, rectangular, or the like. Also, a top film for sealing the inside of the concave portion may be sealed (particularly heat-sealed) in the portion to be sealed between the concave portions, and a cut may be formed through the top film. At least the portion to be sealed of the sheet that comes into contact with the top film is made of an amorphous resin (particularly a polystyrene resin) (A), and a thermoplastic resin (particularly a polyolefin resin) incompatible with the component (A) (B) (Especially a sea-island structure or a bicontinuous structure of the components (A) and (B)), and the top film may be made of the same resin as the component (A) or the component (B). Good. The ratio (weight ratio) of the component (A) and the component (B) constituting the sheet is (A) / (B) = 1.
0 / 90-90 / 10, preferably 30 / 70-80 /
It is about 20. The container is suitable as a container for individually storing a plurality of identical or different foods in a plurality of recesses.

According to the present invention, there is provided a sheet comprising an amorphous resin (A) and a thermoplastic resin (B) incompatible with the component (A), wherein the sheet is used for molding the container. Is also included. In the present invention, a container having a plurality of concave portions is formed from a sheet composed of an amorphous resin (A) and a thermoplastic resin (B) incompatible with the component (A).
After heat sealing the top film composed of the component or the component (B) to seal the inside of the concave portion, a cut is formed through the top film and between adjacent concave portions along the sheet flow direction. Also, a method for manufacturing a container that can divide an adjacent recess is included.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings as necessary.

[Container] FIG. 1 is a perspective view showing an example of the container of the present invention, and FIG. 2 is an enlarged sectional view of the container shown in FIG.

The container 1 shown in FIG. 1 has a plurality of concave portions (accommodating portions) 2 and a flange portion (sealed portion) 3 extending laterally from the top of the side wall of the concave portion 2. A transparent top film 5 is heat-sealed to the flange portion (sealed portion) 3 of the container 1 to seal the housing portion 2. Usually, the storage section 2 stores foods such as tofu. further,
In the center of the flange portion (sealed portion) 3 between the plurality of concave portions, a V-shaped cut 4 for dividing the plurality of concave portions along the flow direction (MD direction) at the time of sheet forming is provided in the container 1.
The flange portion 3 is formed continuously from one end to the other end. As shown in FIG. 3, the notch 4 is formed penetrating the top film 5, and can be easily divided simply by bending it along the MD direction.

The shape of the concave portion is a columnar shape, a polygonal rectangular shape,
A bulge or a sphere can be exemplified, and the diameter of the opening, the diameter of the bottom, the depth, and the like are not particularly limited. In general, a tetrahedral shape is preferable from the viewpoint of container moldability and content filling rate. The shape of each concave portion may be the same as each other, or the shape and size may be changed according to the application. The depth of the concave portion may be changed according to the application, but is preferably substantially the same from the viewpoint of the stability of the container. The number of recesses may be two or more, and is not particularly limited as long as a cut for separating the recesses can be provided between adjacent recesses.

The cross-sectional shape of the cut is not limited to the V-shape.
Examples include a linear shape, a U shape, and a rectangular shape. Among these shapes, from the viewpoint of ease of division, productivity and moldability,
V-shapes and linear shapes are preferred. The cut may be formed not only on one side but also on both sides, but from the viewpoint of productivity, it is preferable to form the cut on only one side.

The length of the cut is not limited to the cut formed continuously from one end to the other end of the container, and may be any length that can be divided. A continuously extending cut, a single or a plurality of perforated cuts, a cut obtained by combining these cuts, and the like can be exemplified. Of these, it is preferable to form a continuous cut from one end to the other end of the container from the viewpoint of ease of dividing the container and moldability. The number of cuts is not particularly limited, but from the viewpoint of productivity, it is sufficient that at least one cut is provided between each adjacent concave portion.

The depth of the cut is determined by the thickness of the sheet.
It is about 5 to 70%, preferably about 15 to 60%, and more preferably about 20 to 50%. If the cut depth is less than 5%, it is difficult to divide the container, and the cut depth is 70%.
%, Cracks occur due to impact or the like. In the case of a container in which the top film is sealed, it is necessary to form a cut through the top film, and the thickness of the top film is not considered in the depth of the cut. Therefore, in the container in which the top film is sealed, the ratio of the depth of cut to the thickness of the sheet is X (mm), the depth of the sheet is Y (mm), and the depth of the sheet is Y (mm), as shown in FIG. At this time, it is represented by (X / Y) × 100. When cuts are provided on both sides, the depth of each cut is added. That is, the depth of the entire cut may be within the above range. In addition, since the notch is usually formed after container molding and film sealing, the sheet thickness is
The thickness of the raw sheet before container molding is not always equal.

The cut may be formed in the sheet flow direction (MD direction), and may be formed in the sheet flow direction (MD direction).
Direction). If it is formed in another direction (for example, TD direction), it is difficult to divide easily, cracks grow in an unintended direction, and the contents of the concave portion may leak. By forming the cut in the MD direction of the sheet, the sheet can be easily divided by folding along the cut and along the MD direction. For example, the number of recesses is not limited to two. When a plurality of recesses are formed adjacent to each other in the TD direction of the sheet, a cut may be formed between the adjacent recesses in the MD direction. Further, when it is necessary to divide the container in a direction different from the MD direction (for example, the TD direction), for example, when a plurality of concave portions are provided in a grid pattern (vertical and horizontal directions), the cut in the MD direction and the TD It can also be used in combination with a perforated cut in the direction.

As long as the cut is formed between adjacent recesses to divide the recess, the cut formation site is
Although there is no particular limitation, it is preferable to provide the flange portion of the container along the central portion between adjacent concave portions from the viewpoint of making the width of the flange portion of the container the same after the division and unifying the external shape.

The top film may be sealed with an adhesive or the like, but from the viewpoint of simplicity, heat sealing is preferred. When it is not necessary to seal the contents, the top film is unnecessary.

Although the material of the container is not particularly limited, it may be composed of an amorphous resin (A) and a thermoplastic resin (B) incompatible with the component (A). With such a configuration, the component (B) is oriented in the flow direction during extrusion, and the resistance to bending in the direction perpendicular to the flow is reduced. Therefore, if a notch having an appropriate depth is made in the sheet flow direction, the sheet can be easily divided. When the container has a top film, it is particularly preferable that at least the portion to be sealed of the sheet in contact with the top film is made of the components (A) and (B).

As the component (A), for example, a polystyrene resin, a polycarbonate resin (bisphenol A)
Polycarbonate resin), acrylic resin (polymethyl methacrylate, etc.), vinyl acetate resin (polyvinyl acetate, etc.), vinyl chloride resin (polyvinyl chloride, etc.), amorphous polyester resin, cyclic polyolefin resin, Examples thereof include polyphenylene ether, polyarylate, polysulfone, and polyetherimide.

As the component (B), for example, olefin resins (crystalline olefin resins), polyamide resins (nylon 6, nylon 66, nylon 6/10, nylon 6/11, nylon 6/12, etc.), Polyester resin (polyalkylene terephthalate such as polyethylene terephthalate and polybutylene terephthalate, copolyester containing alkylene terephthalate as a main component, etc.), liquid crystal polymer (liquid crystal polyester, polyimide, etc.), polyetheretherketone, polyamideimide, polyphenylene sulfide And cellulose esters.

Of these, from the viewpoint of moldability, price, etc.,
As the component (A), a polystyrene resin is preferable,
As the component (B), a polyolefin resin is preferable. By combining polystyrene resin and polyolefin resin and controlling the phase structure, it is possible to balance the characteristics of polystyrene resin such as moldability and rigidity with the characteristics of polyolefin resin such as oil resistance and heat resistance. Can be.

Examples of the polystyrene resin include styrene monomer homopolymers and copolymers. Examples of the styrene monomer include aromatic vinyl monomers [eg, styrene, alkylstyrene (eg, vinyl toluenes such as o-, m-, p-methylstyrene, etc.), and vinyl xylenes such as 2,4-dimethylstyrene. Styrenes, C _2-4 alkyl-substituted styrenes such as p-ethylstyrene, pt-butylstyrene, etc.), α-alkyl-substituted styrene (for example, α-
Methylstyrene, α-methyl-4-methylstyrene, etc.), halogen-substituted styrene (eg, o-, m-, p
-Chlorostyrene, bromostyrene and the like)]. These styrene monomers can be used alone or in combination of two or more. Preferred styrene monomers include styrene, vinyltoluene, α-methylstyrene, and the like, with styrene being particularly preferred.

The polystyrene resin may be a copolymer of the styrene monomer and a copolymerizable vinyl monomer. As the copolymerizable vinyl monomer, for example, a (meth) acrylic alkyl ester [for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, _C1-20 (preferably _C1-8 ) alkyl esters of (meth) acrylates such as lauryl (meth) acrylate, etc., and vinyl cyanide Monomer [eg, (meth) acrylonitrile etc.], carboxyl group-containing monomer or anhydride thereof [eg, (meth) acrylic acid, maleic acid, maleic anhydride, fumaric acid etc.], hydroxyl group-containing monomer [Hydroxy C _2-4 such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate]
Alkyl (meth) acrylate, etc.], epoxy group-containing monomer [eg, glycidyl (meth) acrylate], imide type monomer [eg, maleimide, N-methylmaleimide, N-ethylmaleimide, N-phenylmaleimide, etc. ], Vinyl ester monomers [eg, vinyl acetate, etc.]. These copolymerizable vinyl monomers can be used alone or in combination of two or more.

The copolymerizable vinyl monomer is used in an amount of 0 to 100 parts by weight based on 100 parts by weight of the styrene monomer.
Preferably 0 to 50 parts by weight, more preferably 0 to 25 parts by weight.
It can be selected from a range of about parts by weight.

The polystyrene resin of the component (A) may have a rubber component by kneading, grafting or block copolymerization, if necessary. Examples of the rubber component in the rubber-containing styrene resin include non-styrene rubbers such as conjugated diene rubbers (butadiene rubber, butadiene-isoprene rubber, butadiene-acrylonitrile rubber, isoprene, etc .; styrene-butadiene rubber, styrene-isoprene rubber) Styrene rubber, etc.), ethylene-propylene rubber (EPDM rubber), acrylic rubber,
Examples thereof include an ethylene-vinyl acetate copolymer and chlorinated polyethylene. The butadiene rubber may be of high cis type having a high content of cis-1,4-structure,
Any low-cis type with a low content of 1,4-structure may be used.

The content of the rubber component in the resin composition containing the rubber-containing styrenic resin is 0.5 to 20% by weight (for example, 1 to 20% by weight), preferably 1 to 18% by weight (for example, 3% by weight). To 15% by weight), more preferably 4 to 15% by weight (for example, 5 to 15% by weight), particularly 5 to 10% by weight.
It is about.

The polymerization form of the copolymer is not particularly limited.
There may be grafts, blocks, random, tapered blocks, and the like. Also, the structure of the block copolymer is not particularly limited, and may be linear or star.

As the polystyrene resin, for example, polystyrene (GPPS), styrene-methyl methacrylate copolymer (MS resin), acrylonitrile-styrene copolymer (AS resin), rubber-containing styrene resin [for example, impact-resistant Polystyrene (HIPS), acrylonitrile-butadiene rubber-styrene resin (ABS resin),
Butadiene-styrene-maleic anhydride copolymer (rubber-modified styrene-maleic anhydride copolymer), acrylonitrile-ethylene propylene rubber-styrene resin (AE
S resin), acrylonitrile-butadiene rubber-methyl methacrylate-styrene resin (ABS resin), acrylonitrile-n-butyl acrylate rubber-styrene resin (AAS resin), acrylonitrile-ethylene-vinyl acetate-styrene resin, acrylonitrile-chlorinated polyethylene Graft copolymers such as styrene resin; block copolymers such as styrene-butadiene copolymer (SB resin), styrene-butadiene-styrene copolymer (SBS resin) and styrene-isoprene-styrene copolymer (SIS resin). Polymer]. Further, the rubber-containing styrenic resin may be a hydrogenated product.

The weight average molecular weight of the polystyrene resin (for the rubber-containing styrene resin, the styrene resin constituting the matrix) is 1 × 10 ⁴ to 10 × 10 ⁵ , preferably 2 × 10 ^{4 to} 5 × 10 ⁵ , More preferably, 5 × 10 ⁴
About 3 × 10 ⁵ .

Examples of the polyolefin resin include olefin homopolymers and copolymers. Examples of the olefin include ethylene, propylene, 1-butene, isobutene, 4-methyl-1-butene, 1-pentene, and 3-olefin.
Examples thereof include C _2-10 -α-olefins such as methyl-1-pentene, 1-hexene, and 1-octene. These olefins may be used alone or in combination of two or more. Among these olefins, ethylene and propylene, particularly propylene, are preferred.

The polyolefin resin may be a copolymer of an olefin and a copolymerizable monomer. Examples of the copolymerizable monomer include (meth) acrylic esters [eg, C _1-6 alkyl (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate]; vinyl esters ( For example, vinyl acetate, vinyl propionate, etc.); cyclic olefins (norbornene, ethylidene norbornene, cyclopentadiene, etc.); dienes (butadiene, isoprene, etc.) can be exemplified. The copolymerizable monomers can be used alone or in combination of two or more. The amount of the copolymerizable monomer to be used can be selected from the range of 0 to 100 parts by weight, preferably 0 to 50 parts by weight, more preferably 0 to 25 parts by weight, based on 100 parts by weight of the olefin.

As the polyolefin resin, a polyethylene resin [eg, low, medium or high density polyethylene,
Linear low-density polyethylene, ethylene-propylene copolymer, ethylene- (meth) acrylic acid copolymer, ionomer, ethylene- (meth) acrylate, ethylene-vinyl acetate copolymer, etc.], polypropylene resin (for example, Propylene-based resin having a propylene content of 80% by weight or more such as polypropylene, propylene-ethylene copolymer, propylene-butene copolymer, and propylene-ethylene-butene copolymer), and methylpentene resin. Among these polyolefin-based resins, propylene-based resins having a propylene content of 80% by weight or more, such as polypropylene, a propylene-ethylene copolymer, and a propylene-butene copolymer, are preferable from the viewpoints of heat resistance, economy, and the like.

The polyolefin resin has an isotactic index of 50 to 100%, preferably 60 to 1%.
00%, more preferably about 70 to 100%.

It is preferable that the component (A) and the component (B) form a sea-island structure or a both (co) continuous structure (network structure). The sea-island structure includes a mutually incompatible (immiscible) sea component (sea polymer) and an island component (island polymer),
A sea-island structure (dispersed structure) is formed by phase separation. Further, in the sea-island structure, in any one of the MD direction and the TD direction, they exist in a state of being independent of each other in the form of particles or fibers. The sea-island structure can be formed by adjusting the melt viscosity, fluidity (such as melt index), and content of the sea component (matrix component) and the island component. Further, the melt viscosity, fluidity and content of the sea component and the island component, and the kneading conditions (temperature, shearing force, etc.) greatly affect the size and shape of the island component. For example, when two components having different melt viscosities are used, generally, a resin having a high melt viscosity and a high content tends to be a sea component (matrix component).

The proportion of the island component is within a range in which the island component can be formed stably according to the type of the sea component (for example, 0.5 to 40% by weight in terms of solid content based on the total amount of the sea component and the island component). For example, 1 to 40% by weight (e.g., 5 to 3 wt.
5% by weight), preferably 5 to 30% by weight (for example, 5 to 5% by weight).
25% by weight). If the proportion of the island polymer is too large, it is easy for the island components to fuse with time, and it is difficult to control the size of the island component. If the proportion of the island polymer is too small, the efficiency of forming dispersed particulate island components is increased. Tends to decrease. When an olefin-based resin (particularly, a polypropylene-based resin) forms a matrix, oil resistance can be greatly improved. The melt viscosity can be controlled by various methods, for example, by adjusting the molecular weight of the island polymer and the sea polymer, the type of the substituent, and the degree of substitution.

The bicontinuous structure has a phase-separated structure in which a plurality of resin components are mixed in a network shape in any of the MD and TD directions.
In particular, a container having a network structure (bicontinuous structure) in which a styrene-based resin and an olefin-based resin are continuously dispersed is excellent in heat resistance, oil resistance, and the like.

The above-mentioned bicontinuous structure can also be obtained by adjusting the melt viscosity, fluidity and content of each resin, kneading conditions and the like. When the network structure is composed of, for example, a two-component resin, the proportions of the respective components are substantially equal to each other [for example,
The ratio of one resin to the other is 40 / 60-60.
/ 40 (weight ratio)].
When the melt viscosity of one resin is reduced, a wide quantitative ratio [for example, the ratio of one resin to the other resin is 30 /
70-70 / 30 (weight ratio)], a bicontinuous structure can be formed.

Even when three or more resin components are used in each resin layer, a sea-island structure or a bicontinuous structure can be formed by adjusting the above conditions (for example, melt index and content).

The ratio (weight ratio) of component (A) to component (B) is 10/90 to 90/10, preferably 30/7.
0-80 / 20, more preferably 50 / 50-70 /
It is about 30. If the proportion of the component (A) is too small, the rigidity is reduced and division is difficult, the formability of the sheet is reduced, and the adhesive strength with the top film cannot be controlled. Incompatible.
When the proportion of the component (A) is too large, not only the heat resistance and oil resistance are reduced, but also the easy opening and sealing properties of the top film cannot be compatible.

In addition to the components (A) and (B), a compatibilizer (C) may be added. The component (C) can be selected according to the type of resin used. As the compatibilizer when using a polystyrene resin and a polyolefin resin, for example, (C-1) (random or block) copolymer of a styrene monomer and a conjugated diene compound or a hydrogenated product thereof, (C-2) an epoxy-modified product of a copolymer of a styrene-based monomer and a conjugated diene compound or a hydrogenated product thereof, (C-3) a styrene-based monomer serving as a constituent unit of a polystyrene-based resin, and a polyolefin Copolymer with an olefin monomer as a constitutional unit of the resin, (C-4) a copolymer of a styrene monomer and a carboxyl group-containing vinyl compound or an acid anhydride group-containing monomer thereof Etc. can be exemplified. As the styrene monomer, the conjugated diene compound and the olefin, the compounds exemplified above can be used.

Typical hydrogenated copolymers include, for example, hydrogenated rubber-modified styrene resins [styrene-ethylene-butylene-styrene (SEBS) copolymer, styrene-ethylene-propylene-styrene (SEPS) copolymer]. Coalescence etc.] can be illustrated. The hydrogenated copolymer also includes a random or block copolymer of a styrene monomer and at least one α-olefin.

As the epoxy-modified copolymer, a polymer block mainly composed of a styrene monomer (such as styrene) and a conjugated diene compound (such as butadiene and isoprene) are mainly contained in the same molecule. Among the block copolymers composed of a polymer block (such as a polybutadiene block) and its partially hydrogenated product, an epoxy-modified block copolymer in which a double bond derived from a conjugated diene compound is epoxidized, etc. Can be illustrated. The ratio between the styrene monomer and the conjugated diene compound is
It can be appropriately selected from the range of about 5/95 to 95/5 (weight ratio).

Component (C) is added in an amount of 0.1 to 3 based on 100 parts by weight of the total of components (A) and (B).
0 parts by weight, preferably 0.5 to 15 parts by weight, more preferably about 1 to 15 parts by weight, and can be usually selected from the range of about 1 to 10 parts by weight.

The sheet forming the container may be a monolayer composed of the components (A) and (B),
It may be a laminate with another thermoplastic sheet. In the case of a laminate, the portion in contact with the top film is (A)
What is necessary is just to be comprised with a component and (B) component, For example,
2 wherein the layer in contact with the top film is composed of the above components
Examples thereof include a laminate of layers and a laminate of two or three layers, three or four layers, or two or five layers in which the outermost layer is composed of the above components. The resin non-foamed sheet used in the case of the laminated body is appropriately selected from a desired material in accordance with the application and the property to be imparted, for example, heat resistance, abrasion resistance, improvement in surface appearance, printing characteristics. it can. Among these, a single-layer body and a two-layer three-layer laminate [for example, a laminate in which the intermediate layer is composed of the component (A) (particularly, a polystyrene resin)] are preferable.

In the case of a laminate, a waste resin can be reduced by adding a pulverized product of punching chips and skeletons generated at the time of forming the container to the intermediate layer, and an environment-friendly container can be obtained. In addition, those laminated with different types of thermoplastic resins,
For example, additional heat resistance can be imparted by laminating with a polypropylene resin, and oxygen barrier properties can be imparted by laminating with an ethylene vinyl alcohol resin (EVOH resin) or maleic anhydride-modified polypropylene.
In these cases, it is necessary to consider the layer thickness of the different resin and the degree of cut so as not to impair the performance of easily dividing the container. For example, if splitting is difficult due to an intermediate barrier layer, cut into the barrier layer,
Only the resin that is easily divided may be left.

The sheet forming the container may further include, if necessary, a stabilizer (antioxidant, ultraviolet absorber, heat stabilizer, etc.), a flame retardant, a lubricant, a release agent, an antistatic agent, talc and the like. Inorganic fillers, coloring agents such as pigments, dispersants such as higher fatty acids, plasticizers, conductivity-imparting agents, and antistatic agents such as silicones can be added.

In a container in which the top film is heat-sealed, the adhesive strength between the top film and the sheet is as follows:
When peeling the top film from the sheet, the strength is such that the top film can be easily peeled from the sheet,
Specifically, 2 to 25 N / 15 mm, preferably 5 to 20
N / 15 mm. If the bond strength is too weak, for example,
The top film may be peeled off during transportation and the contents may be damaged, or the internal pressure of the container may be increased due to a long stay at a high temperature, and the top film may be peeled off. On the other hand, if the adhesive strength is too strong, the easy-opening property is impaired, and the base sheet or the top film is damaged at the time of opening, and the contents are scattered. The heat seal strength was measured by the method described in Examples, and the heat seal conditions were, for example, a temperature of 100 to 300 ° C. and a pressure of 10,000 to 300,000 N.
/ M ² within the range of 0.1 to 10 seconds.

In order for the adhesive strength between the top film and the sheet to be within the above range, the resin constituting the top film is preferably the same type of resin as the component (A) or the component (B). The adhesive strength with the top film varies depending on the structure of the resin of the sheet that comes into contact with the top film. If the sheet that comes into contact with the top film has a sea-island structure, the same type of resin as the matrix component (bicontinuous structure) In this case, either is acceptable).

The resin constituting the top film is usually
Polyolefin resin, but in this case contact
The matrix component of the sheet is a polyolefin resin
Or polyolefin resin is one component of both continuous layers
Is preferred. However, polyolefin resin is rigid
Is low, and if added in large amounts, the container cannot be easily divided
There is a risk of becoming. Therefore, the addition of polyolefin resin
In order to minimize the amount and improve the adhesive strength,
Olefin resin is a matrix component with sea-island structure
Component) or one component of a bicontinuous structure,
Melt viscosity (η _(A)) Of polyolefin resin
Melt viscosity (η_(B)) Must be set low. Each resin
Melt viscosity of a conventional capillary rheometer
Can be measured under various conditions depending on the purpose.
Can be measured. For example, styrene resin and olefin resin
If combined with fat, set temperature 210 ° C and shear rate
1.216 × 10^Two(Sec^-1), Diameter = 1.0m
m, L = 20 mm, D = 1.0 mm, barrel system = 9.5
Using a 5 mm nozzle, a rheometer (capillary
And Toyo Seiki Co., Ltd.). concrete
Is the viscosity ratio of the component (A) to the component (B), η_(A)/
η_(B)= 0.5-5.0, preferably 1.0-4.5
It is important to set the range. Set temperature to 210 ° C
Generally speaking, polystyrene resin and polyp
The melt viscosity of the propylene-based resin is almost
In order to show the same inclination, the shear rate of 1.2
16 × 10^Two(Sec^-1) Is especially specified during kneading.
And the shearing history experienced by the resin during molding
It is.

The container of the present invention can easily divide a plurality of storage portions and is excellent in heat resistance and oil resistance, so that foods containing a large amount of fats and oils (for example, foods containing fats and oils such as dumplings, fish and shellfish) It is useful as a container for food), a container heated in an oven or a microwave oven, a container heat-sterilized during production and use, various non-heated containers, frozen food containers, confectionery containers, chemical containers, and the like. In particular, since the contents can be divided and stored in a sealed state, foods (gel foods such as tofu, pudding, jelly, and solid foods such as prepared foods, oil-and-fat-containing foods, and confectionery) and medicines can be stored in containers. It is useful for containers whose contents are hermetically sealed.

[Method of Manufacturing Container] The method of manufacturing the sheet forming the container of the present invention is not particularly limited. For example, kneaders such as kneaders, Banbury mixers, rolls, ribbon blenders, Henschel mixers, etc. may be used, if necessary. The resin composition prepared by a mixer or the like is supplied to a single-screw or twin-screw extruder, melted and kneaded by heating, and extruded from a die [flat shape, T shape (T die), cylindrical shape (circular die), etc.]. Can be molded. The die only needs to have a lip opening corresponding to the thickness of the sheet. The sheet obtained by the sheet forming method may be uniaxially or biaxially stretched as necessary. In the case of a laminated sheet, the resin composition used for each constituent layer is molded by a plurality of extrusion molding machines, and the obtained sheet-like molded body is laminated by heating and laminated, or manufactured by a dry lamination method or the like. Alternatively, the resin composition for each constituent layer may be co-extruded using a general-purpose die with a feed block, a multi-manifold die, or the like.

The resin sheet thus obtained is excellent in moldability, and is therefore formed by vacuum forming, pressure forming (extrusion pressure forming, hot plate pressure forming, vacuum pressure forming, etc.), free blow forming, bending, matching. Secondary molding can be easily performed by conventional thermoforming such as molding and hot plate molding.

The container of the present invention includes a container without a top film and a container in which the top film is heat-sealed, depending on the use. In the case of a container without a top film, one side or both sides of the secondary molded article are used. By providing the cuts, the container is manufactured.

In the case where the top film is a heat-sealed container, a cut may be formed in the secondary molded product and the top film may be cut separately. After the top film is heat-sealed, it is preferable to make a cut through the top film from the upper surface of the secondary molded product.

[0061]

According to the container of the present invention, a plurality of storage portions can be easily divided, so that even if only a part of the storage material is consumed, the remaining storage portion can be preserved by separating the storage portion. In particular, in the case of a container in which the top film is heat-sealed, the container can be stored in a sanitary manner because the sealing property is maintained. In addition, the container of the present invention can be distributed to a large number of people at once and distributed, so that it is suitable for use in resorts and the like. Further, since the container of the present invention is excellent in heat resistance, oil resistance and moldability, it can be easily molded into various containers and can be used for various applications.

[0062]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The contents of the abbreviations of each component used in Examples and Comparative Examples, and the evaluation methods of each evaluation item are as follows.

[Contents of Abbreviations of Each Component] (A) Component A-1: Polystyrene (# 30, Toyo Styrene Co., Ltd.)
Ltd., melt viscosity ^{877N · sec / m 2) A} -2: Polystyrene (# 10, TOYO STYRENE Co.,
Ltd., melt viscosity ^{386N · sec / m 2) A} -3: high impact polystyrene (S85, TOYO STYRENE Co., melt viscosity 986N · sec / m ^2).

(B) Component B-1: Polypropylene (B101WA, manufactured by Grand Polymer Co., Ltd., melt viscosity = 1100 N · sec / m ² ) B-2: Polypropylene (J106M, manufactured by Grand Polymer Co., melt viscosity = 368 N · sec / m ² ) B-3: Polypropylene (J108M, manufactured by Grand Polymer Co., Ltd., melt viscosity = 214 N · sec / m ² ) B-4: Polypropylene (FL100, manufactured by Grand Polymer Co., melt viscosity = 461 N · sec / m ² ) B-5: Polypropylene (J103, manufactured by Grand Polymer Co., Ltd., melt viscosity = 509 N · sec / m ² ).

The melt viscosity was measured at a set temperature of 210 ° C. and a shear rate of 121.6 (sec ⁻¹ ) at a diameter of 1.0 m.
m, L = 20 mm, D = 1.0 mm, barrel system = 9.5
The measurement was performed with a rheometer (Capillograph, manufactured by Toyo Seiki Co., Ltd.) using a 5 mm nozzle.

(C) Component C-1: Styrene-butadiene-styrene copolymer (T
R2003, manufactured by JSR Corporation, rubber content 57% by weight) C-2: Styrene-ethylene-propylene-styrene copolymer (Septon 2104, manufactured by Kuraray Co., Ltd.) C-3: Styrene-ethylene-butylene-styrene Copolymer (Clayton G1650, manufactured by Shell Co., Ltd.) C-4: Epoxy-modified styrene-butadiene copolymer (Epofriend A1020, Daicel Chemical Industries, Ltd.)
C-5: Hydrogenated epoxy-modified styrene-butadiene copolymer (JP-A-7-25984, page 2, column 2, 31-4)
According to the method described in the third row, hydrogen was added to Epofriend A1020 manufactured by Daicel Chemical Industries, Ltd.).

[Peel strength] A thermoplastic resin sheet (sheet sheet) was covered with a polypropylene composite film [laminate film of polyethylene terephthalate film (PET) 20 µm and unstretched polypropylene film (CPP) 20 µm]. PM-R manufactured by
Using a mold, at a temperature of 200 ° C and a gauge pressure of 0.4MP
a, Under the conditions of a time of 1.0 second, the CPP layer was superimposed on the raw sheet and heat-sealed. Then, heat-sealed part 1
Cut to a width of 5 mm and a tensile tester (Tensilon, manufactured by Orientec Co., Ltd.) at a tensile speed of 10 mm / min.
An 80 ° peel test was performed to measure the peel strength, which was evaluated according to the following criteria. In Comparative Example 4, a CPP film was used instead of the polypropylene composite film.

：: more than 5 N / 15 mm and 20 N / 15 mm or less Δ: 2 to 5 N / 15 mm or 20 to 25 N / 15 mm ×: less than 2 N / 15 mm or more than 25 N / 15 mm.

[Container Formability] Using a single-shot vacuum forming machine (manufactured by Asano Research Institute Co., Ltd.), a container having two concave portions shown in FIG. 1 (a flange length of 183 mm × a flange width of 88 mm, an opening portion length of 71 mm × width). 71mm, bottom length 60mm x width 60
(mm, depth 27 mm), and the portion where the bottom surface and the side surface are in contact with each other, the tear of the side surface, and the surface state (appearance and gloss) were visually observed and evaluated according to the following criteria.

：: No breakage, good surface condition △: No breakage, but uneven unevenness on surface ×: Breakage

[Heat deformation resistance] Heat resistance was evaluated in accordance with JIS S 2033. First, a rectangular container (140 m long) was placed on a straight plate of a thermostat with air stirring.
m, width 105 mm, height 20 mm), and the temperature of the constant temperature bath is raised by 5 ° C. in a range of 80 to 140 ° C., and during that time, the degree of deformation of the container is visually observed. I asked.

[Separability] Using a single-shot vacuum forming machine (manufactured by Asano Laboratories), a container having two concave portions shown in FIG. 1 was formed, and the top film was heat-sealed in the same manner as in the peel strength test. After that, the sheet thickness of 0.
A notch having a depth of 0.24 mm was provided from the upper surface of the container with a cutter knife for 6 mm to obtain a container shown in FIG. In Comparative Example 4, a cut was provided from the side opposite to the surface on which the top film was sealed. The depth of cut was measured with a digital electron microscope (Keyence Corporation). Then, as shown in FIG. 3, the container is bent by hand in a direction in which both ends of the container come into contact with each other with the center portion between the concave portions as a base point. , And the divisibility was evaluated based on the following criteria.

◎: When both ends come into contact, they are almost half broken at the same time. ○: Even when both ends come into contact, they do not break into half. However, when a load is applied, they are split into half. Δ: Before both ends come into contact, they are split into half. It does not break even if it is applied.

Examples 1 to 12 and Comparative Examples 1 to 3 A resin composition having the composition shown in Table 1 was mixed with a twin-screw extruder (Ikegai Co., Ltd.)
Manufactured by PCM30), and extruded into strands were cut into resin pellets. This resin pellet is extruded (diameter 65 mm, L / D = 32)
The mixture was melt-kneaded and extruded from a T-die to obtain a single-layer resin sheet having a thickness of 0.57 mm.
Table 1 shows the evaluation results of the obtained resin sheets.

Example 13 A resin composition having the composition shown in Table 1 was mixed with a twin-screw extruder (Ikegai Co., Ltd.)
Manufactured by PCM30), and extruded into strands were cut into resin pellets. This resin pellet was placed in a second extruder (diameter 40 mm, L / D =
28), and pulverized sheet obtained from the resin pellets is passed through a first extruder (65 mm in diameter, L / D
= 32), melt-kneaded, and extruded from a T-die to obtain a two-type three-layer resin sheet (thickness 0.57 mm) having a lamination ratio (thickness) of 1: 14: 1. Table 1 shows the evaluation results of the obtained resin sheets.

Comparative Example 4 A resin composition having the composition shown in Table 1 was mixed with a twin-screw extruder (Ikegai Co., Ltd.)
Manufactured by PCM30), and extruded into strands were cut into resin pellets. This resin pellet is extruded (diameter 65 mm, L / D = 32)
And melt-kneaded, and then extruded from a T-die to obtain a single-layer resin sheet having a thickness of 0.55 mm.
A CPP film having a thickness of 0.025 mm was laminated thereon by heat to obtain a resin sheet. Table 1 shows the evaluation results of the obtained resin sheets.

[0077]

[Table 1]

From the results shown in Table 1, the sheets and containers of the examples have a bicontinuous structure or a sea-island structure in which the component (A) is an island, and are excellent in easy-opening properties, moldability, heat resistance, and division properties.
In contrast, the sheets and containers of Comparative Examples 1 and 3
(A) Since the component is not sufficiently mixed, easy opening property,
Moldability and splitting properties are not sufficient. The sheet and the container of Comparative Example 2 form a sea-island structure in which the component (A) is a sea, and the peel strength is too weak, and the heat resistance and the dividing property are not sufficient. In the sheet and the container of Comparative Example 4, since the component (A) and the component (B) are laminated as separate sheets, the easy-openability, heat resistance, and division property are not sufficient.

Example 14 The thickness obtained from the resin composition having the same composition as that of Example 6 was 0.1 mm.
Adjust 6mm sheet, 0.02mm, 0.04m
m, 0.08 mm, 0.16 mm, 0.24 mm, 0.
Slits of 32 mm, 0.40 mm, and 0.50 mm were made with a knife, and the slits were bent with fingers so as to widen the cuts, and evaluated according to the following criteria. Table 2 shows the results.

◎: Cracked by pressing the slit portion after bending. ：: Cracking only by bending. だ け: Cracking only by bending with extremely weak force. ×: Cracks run in portions other than the slit.

[0081]

[Table 2]

From the results shown in Table 2, the cutting depth is preferably 5 to 70%, particularly preferably about 15 to 60%, based on the sheet thickness.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the container of the present invention.

FIG. 2 is an enlarged cross-sectional view of the container of FIG. 1 taken along line AA.

FIG. 3 is a side view for explaining a dividability test of an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Container 2 ... Concave part (accommodation part) 3 ... Flange part (sealed part) 4 ... Cut 5 ... Top film

Claims (13)

[Claims] 1. A container having a plurality of recesses, wherein cuts for dividing adjacent recesses are formed between adjacent recesses along the sheet flow direction. 2. The container according to claim 1, wherein the depth of the cut is 5 to 70% with respect to the thickness of the sheet. 3. The cross section of the cut has a linear shape, a V shape,
2. The container according to claim 1, wherein the container has at least one shape selected from a U-shape and a rectangular shape. 4. The container according to claim 1, wherein the top film for sealing the inside of the recess is a container sealed in a portion to be sealed between the recesses, wherein a cut is formed through the top film. Container. 5. The container according to claim 4, wherein the top film is heat-sealed. 6. A sealed portion of a sheet at least in contact with a top film is formed of an amorphous resin (A) and a thermoplastic resin (B) incompatible with the component (A).
The container according to claim 4, wherein the top film is made of the same resin as the component (A) or the component (B). 7. The container according to claim 6, wherein at least the portion to be sealed of the sheet in contact with the top film has a sea-island structure or a bicontinuous structure of the components (A) and (B). 8. The component (A) is a polystyrene resin, and the component (B) is a polyolefin resin.
The container as described. 9. The ratio (weight ratio) of the component (A) and the component (B) constituting the sheet is (A) / (B) = 10/90.
The container according to claim 6, wherein the ratio is from 90 to 90/10. 10. A top film having a plurality of concave portions, a top film for sealing the inside of the concave portions is heat-sealed to a portion to be sealed between the concave portions, and a cut for dividing an adjacent concave portion penetrates the top film. And a container formed between adjacent recesses along the sheet flow direction, wherein the top film is made of a polyolefin-based resin, and at least the portion to be sealed of the sheet in contact with the top film is a polystyrene-based resin. It has a bicontinuous structure composed of (A) and the polyolefin resin (B) or a sea-island structure having the component (B) as a matrix, and a ratio (weight) of the component (A) to the component (B) constituting the sheet. Ratio),
A container wherein (A) / (B) = 30/70 to 80/20. 11. The container according to claim 4, wherein a plurality of the same or different foods are individually accommodated in the plurality of recesses. 12. A non-crystalline resin (A) and (A)
A sheet for forming the container according to claim 1, which is a sheet made of a thermoplastic resin (B) incompatible with the components. 13. A non-crystalline resin (A), and (A)
A container having a plurality of concave portions is formed from a sheet composed of a thermoplastic resin (B) incompatible with the component, and the top film composed of the component (A) or the component (B) is heat-sealed. A method of manufacturing a container capable of dividing adjacent recesses by sealing the inside of the recesses, then penetrating the top film, and forming cuts between the adjacent recesses in the sheet flow direction.