JP7120882B2 - Anti-fogging sheet and container - Google Patents

Description

TECHNICAL FIELD The present invention relates to an antifogging polypropylene sheet and a cup-shaped container formed by molding the sheet.

2. Description of the Related Art Conventionally, thermoformed transparent resin sheets have been widely used in packaging containers for foodstuffs and the like, because it is required to improve the visibility of the contents.
For example, an amorphous polyethylene terephthalate resin sheet (A-PET) is used for moldings for which there is a strong demand for transparency, and is also widely used for deep drawing containers for drinks and the like.
However, since A-PET may deform when the temperature rises above a certain level, when higher heat resistance is required, a polypropylene sheet is used instead of A-PET to produce thermoformed products such as packaging containers. Fabrication is being done. Also, since polypropylene has a lower specific gravity than A-PET, it has the advantage of reducing waste when discarded by the final user.

By the way, polypropylene sheets are excellent in transparency and heat resistance, but on the other hand, since they are made of a hydrophobic material, water vapor condenses on the inner surface due to temperature differences between the inside and outside of the container and changes in internal humidity. Since the condensed water does not spread easily when it is wetted, the water becomes minute water droplets and easily stays on the surface.
If such water droplets adhere over a wide area, the visibility inside the container is reduced. The occurrence of cloudiness not only has the problem of lowering the commercial value of packaging containers characterized by transparency, but also has the risk of water droplets adhering to the contents and deteriorating the quality thereof.
Therefore, polypropylene sheets and deep-drawn containers used for such applications are required to exhibit anti-fogging properties.

As methods for imparting antifogging properties to a polypropylene sheet, a coating method and a kneading method have been proposed so far.
As a coating method, for example, Patent Document 1 discloses a method of coating a mixture of polyglycerin fatty acid ester and sucrose fatty acid ester.
As a kneading method, for example, Patent Document 2 discloses a method of kneading an alkyl dialcoholamide additive into a polypropylene resin during extrusion to form a sheet.

Japanese Patent No. 5840520 JP-A-10-67867

However, when the sheet described in Patent Document 1 is molded into a container shape by the plug assist method, the anti-fogging agent on the surface tends to be scraped off due to the contact of the plug with the sheet during molding, especially when the drawing ratio is low. A deep cup of 1 or more has a problem of deteriorating anti-fogging properties.
In addition, although the container manufactured by the method described in Patent Document 2 exhibits antifogging properties in shallow drawing with a drawing ratio of 0.5 or less, it can be used as a deep container with a drawing ratio of 0.5 or more. Then, there is a problem that the antifogging property is lowered.

The present invention solves such conventional problems, and exhibits a polypropylene sheet with small thickness deviation and reduced blocking without impairing the properties of polypropylene, and excellent antifogging properties. The object of the present invention is to provide a polypropylene cup-shaped container which is a deep-drawn molded product with good visibility of .

That is, the present invention is as follows.
(1) A polypropylene sheet comprising at least a first layer and a second layer, wherein the first layer and the second layer comprise an antifogging agent and polypropylene, and the antifogging agent contains 40 to 80% alkyldiethanolamine. 10 to 50% by weight of glycerin fatty acid ester, and 5 to 20% by weight of polyethylene glycol alkyl acid ester, and each layer containing the antifogging agent and the polypropylene contains the antifogging agent. 0.05 to 0.5% by mass , the content (% by mass) of the antifogging agent in the first layer is greater than the content (% by mass) of the antifogging agent in the second layer, and the An antifogging polypropylene sheet characterized by having a thickness of 0.5 to 3 mm.
(2 ) The thickness of the first layer is 0.05 to 1.5 mm, the thickness of the second layer is 0.25 to 2.7 mm, and the thickness ratio between the first layer and the second layer The antifogging polypropylene sheet according to (1 ) , wherein (first layer:second layer) is 1:1 to 1:9.
( 3 ) An anti-fogging property comprising the anti-fogging polypropylene sheet according to (1) or (2) , having a drawing ratio of 0.5 or more and a side haze value of 10% or less. Polypropylene cup type container.
( 4 ) The antifogging polypropylene cup-shaped container according to ( 3 ), wherein the first layer of the antifogging polypropylene sheet serves as an inner surface.
( 5 ) The method for producing an anti-fogging polypropylene cup-shaped container according to ( 3 ) or ( 4 ), characterized by using a plug-assist method.

According to the present invention, it is possible to obtain a polypropylene sheet with reduced blocking properties and excellent sheet thickness variation without impairing the properties of polypropylene. Further, it is possible to provide a polypropylene cup-shaped container, which is a deep-drawn molded article containing the sheet and having excellent anti-fogging properties and visibility of the contents.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the cup-shaped container of this invention, (a) is a shape with a draw ratio of 0.68, (b) is a shape with a draw ratio of 1.4.

Hereinafter, embodiments of the present invention (hereinafter simply referred to as "present embodiments") will be described in detail. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

Polypropylene Sheet The antifogging polypropylene sheet of the present embodiment contains 0.05 to 0.5% by mass of an antifogging agent containing 40 to 80% by mass of alkyldiethanolamine, has a thickness of 0.5 to 3 mm, and contains the antifogging agent. It is characterized by having a first layer comprising a clouding agent and polypropylene.

Layer of Polypropylene Sheet The antifogging polypropylene sheet of the present embodiment has a first layer containing an antifogging agent containing 40 to 80% by mass of alkyldiethanolamine and polypropylene. The anti-fogging polypropylene sheet of the present embodiment may further have a layer containing the anti-fogging agent and polypropylene in addition to the first layer, and a layer other than the layer containing the anti-fogging agent and polypropylene It may have layers.

Antifogging Agent The antifogging agent of the present embodiment contains 40 to 80% by weight of alkyldiethanolamine with respect to 100% by weight of the antifogging agent. Particularly preferably, it is 50 to 70% by mass. Alkyldiethanolamine alone exhibits antifogging properties and has the effect of reducing aggregation of other components of the antifogging agent. When the alkyldiethanolamine is 40% by mass or more, the antifogging property can be sufficiently exhibited when molded into a deep-drawn container shape, and when it is 80% by mass or less, the transparency can be obtained when molded into a deep-drawn container shape. Good. Moreover, if it is 50% by mass or more, the antifogging property is further improved, and if it is 70% by mass or less, the transparency is further improved.

The alkyl group (used in the sense of including an alkenyl group) of the alkyldiethanolamine has about 8 to 22 carbon atoms, preferably about 12 to 18 carbon atoms. Specific examples include lauryldiethanolamine, myristyldiethanolamine, palmityldiethanolamine, stearyldiethanolamine, oleyldiethanolamine, and mixtures thereof. Among these, it is particularly preferable to use an alkyldiethanolamine containing 50% by mass or more of stearyldiethanolamine based on 100% by mass of the alkyldiethanolamine.

Moreover, the antifogging agent of the present embodiment is preferably a ternary system of alkyldiethanolamine, glycerol fatty acid ester and polyethylene glycol alkylate.

As the glycerin fatty acid ester, any of monoglycerin fatty acid ester, diglycerin fatty acid ester, and triglycerin fatty acid ester may be used, but monoglycerin fatty acid ester is particularly preferable.
As the monoglycerin fatty acid ester, a monoglycerin ester of a saturated or unsaturated fatty acid having 12 to 18 carbon atoms is preferred. Specific examples include monoglycerin laurate, monoglycerin myristate, monoglycerin palmitate, monoglycerin stearate, monoglycerin oleate, monoglycerin linolate and the like.
As the diglycerin fatty acid ester, a diglycerin ester of a saturated or unsaturated fatty acid having 12 to 18 carbon atoms is preferred. Specific examples include diglycerin laurate, diglycerin myristate, diglycerin palmitate, diglycerin stearate, diglycerin oleate, diglycerin linolate and the like.
As the triglycerin fatty acid ester, a saturated or unsaturated fatty acid triglycerin ester having 12 to 18 carbon atoms is preferable. Specific examples include triglycerin laurate, triglycerin myristate, triglycerin palmitate, triglycerin stearate, triglycerin oleate, triglycerin linolate and the like.

Specific examples of polyethylene glycol alkylate include polyethylene glycol laurate, polyethylene glycol stearate, polyethylene glycol oleate and the like.

When the composition of the antifogging agent is a ternary system of alkyldiethanolamine, glycerin fatty acid ester, and polyethylene glycol alkylate, the content of each component is 40 to 80% with the antifogging agent being 100% by mass. % by mass, particularly preferably 50 to 70% by mass. Glycerin fatty acid ester is preferably 10 to 50% by mass, particularly preferably 20 to 40% by mass. The content of polyethylene glycol alkylate is preferably 5 to 20% by mass, particularly preferably 7 to 15% by mass. If the glycerin fatty acid ester is 10% by mass or more, the anti-fogging property is excellent, and if it is 50% by mass or less, the transparency is good when molded into a deep-drawn container shape. If the polyethylene glycol alkylate is 5% by mass or more, the antifogging property is excellent, and if it is 20% by mass or less, the transparency is good when molded into a deep-drawn container shape.

The content of the antifogging agent is preferably 0.05 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, in each layer containing the antifogging agent and polypropylene. It is preferably 0.08 to 0.3% by mass, and more preferably 0.08 to 0.3% by mass. If it is 0.05% by mass or more, the antifogging property can be sufficiently exhibited when molded into a cup-shaped container, and if it is 0.5% by mass or less, when forming a sheet into a film, blocking property is reduced, and sheet thickness unevenness is good.
In addition, the content of the antifog agent is 0.05 to 0.5% by mass, preferably 0.05 to 0.4% by mass, and 0.08 to 0.3% by mass, relative to the polypropylene sheet. % by mass is more preferred. If it is 0.05% by mass or more, the antifogging property can be sufficiently exhibited when molded into a cup-shaped container, and if it is 0.5% by mass or less, when forming a sheet into a film, blocking property is reduced, and sheet thickness unevenness is good.

Polypropylene Polypropylene (hereinafter also referred to as "PP") refers to a propylene homopolymer, a copolymer of propylene and ethylene, a copolymer of propylene and an α-olefin having 4 to 8 carbon atoms, a copolymer of propylene and ethylene. It means a copolymer with an α-olefin having 4 to 8 carbon atoms, and may be either a random copolymer or a block copolymer.
Specific examples of α-olefins having 4 to 8 carbon atoms include 1-butene, 4-methyl-1-pentene, 1-pentene, 1-hexene, 1-octene and the like, but are particularly limited to these. not.
Among the monomer components constituting these polypropylenes, those other than propylene may be used alone or in combination of two or more. Moreover, each of these polypropylenes may be used alone, or two or more of them may be used in combination.

The content of polypropylene is preferably 80 to 99.95% by mass, more preferably 90 to 99.95% by mass, more preferably 95 to 99.95% by mass, in each layer containing the antifogging agent and polypropylene. More preferably, it is 95% by mass. If it is 80% by mass or more, it is possible to maintain the rigidity when molded into a cup-shaped container. Stability can be obtained.
Further, the content of polypropylene is preferably 80 to 99.95% by mass, more preferably 90 to 99.95% by mass, and 95 to 99.95% by mass with respect to the polypropylene sheet. is more preferred. If it is 80% by mass or more, it is possible to maintain the rigidity when molded into a cup-shaped container. Stability can be obtained.

The polypropylene sheet of the present embodiment may contain various additives such as crystal nucleating agents, lubricants, antioxidants, heat stabilizers, etc., as long as the performance of the molded cup-shaped container is not deteriorated.
When contained in a layer containing an antifogging agent and polypropylene, the content of the additive in the layer may be, for example, 3% by mass or less. Moreover, the content of the additive in the polypropylene sheet may be, for example, 3% by mass or less.

The layer structure of the polypropylene sheet of the present embodiment may be either multiple layers or a single layer, but from the viewpoint of obtaining a high anti-fogging effect, it is preferably a two-layer structure or more including at least the first layer and the second layer. A two-layer structure of the first layer and the second layer is particularly preferred. The same polypropylene resin or different polypropylene resins may be used for the first layer and the second layer.
The content (% by mass) of the antifogging agent in the first layer is preferably higher than the content (% by mass) of the antifogging agent in the second layer. When molded into a cup-shaped container having a first layer with a relatively high antifogging agent content on the inner surface, the antifogging agent bleeds out to the inside of the container, thereby easily exhibiting antifogging performance. In addition, when a cup-shaped container having a second layer with a relatively low antifogging agent content on the outer surface is formed, the amount of the antifogging agent that bleeds out to the outside of the container is small, so the outside of the container is held. It does not feel sticky at times and is good and has excellent printability on the outer surface.

The method of multilayering the sheet is not particularly limited, and a multi-manifold method or a feed port block method may be used.

In the polypropylene sheet of the present embodiment, the thickness ratio of the first layer is preferably 10 to 50%, more preferably 10 to 35%, and even more preferably 10 to 20% when the sheet is multi-layered. Further, the polypropylene sheet of the present embodiment may be a single layer consisting of only the first layer (the ratio of the thickness of the first layer is 100%). If it is 10% or more, the antifogging performance is sufficient, and if it is 50% or less, stickiness due to excessive bleeding out of the antifogging agent can be reduced. In the case of a single layer, by adjusting the content of the antifogging agent, it is possible to suppress stickiness due to excessive bleeding out.
The thickness of the first layer is preferably 0.05 to 1.5 mm, more preferably 0.06 to 1 mm, even more preferably 0.08 to 0.75 mm. Within this range, the antifogging property is good, and stickiness due to excessive bleeding out of the antifogging agent can be suppressed.

The thickness of the second layer is preferably 0.25 to 2.7 mm, more preferably 0.33 to 2.6 mm, even more preferably 0.38 to 2.5 mm. Within this range, the antifogging property is good, and stickiness due to excessive bleeding out of the antifogging agent can be suppressed.

The thickness ratio between the first layer and the second layer (first layer:second layer) is preferably 1:1 to 1:9, more preferably 1:2 to 1:7, and 1:3 to 1:5. is more preferred. Within this range, when molded into a cup-shaped container having the first layer as the inner surface and the second layer as the outer surface, the antifogging performance of the inside is good, the outside is non-sticky, and printability is preferable.

The thickness of the polypropylene sheet of this embodiment is 0.5 to 3 mm, preferably 0.6 to 2.8 mm, more preferably 0.8 to 2.4 mm. When the thickness is 0.5 mm or more, the cup-shaped container is rigid when molded, and when the thickness is 3 mm or less, the cup-shaped container is not excessively rigid, which is preferable.

The thickness accuracy (thickness distribution) of the polypropylene sheet of the present embodiment is preferably less than ±10% with respect to the center value. If the thickness accuracy is within this range, the sheet can be wound into a roll with less wrinkles and unevenness.

The method for producing a polypropylene sheet is not particularly limited, but for example, the resin of each layer is melt-kneaded at a temperature of 160 to 240 ° C. with a co-directional twin-screw extruder (30 to 40 mmφ, L / D 35), followed by a multi-manifold method or A method of laminating each resin by a feed port block method or the like, extruding it from a T-die, and rapidly cooling it at 40 to 80° C. with a cast roll to solidify it can be mentioned.

Polypropylene cup-shaped container The polypropylene cup-shaped container of the present embodiment contains the antifogging polypropylene sheet, has a drawing ratio of 0.5 or more, and has a side haze value of 10% or less.
Moreover, it is preferable that the first layer of the antifogging polypropylene sheet serves as an inner surface of the polypropylene cup-shaped container of the present embodiment. When the first layer is the inner surface, the antifogging agent bleeds out to the inside of the container, thereby easily exhibiting antifogging performance.

The draw ratio of the polypropylene cup-shaped container of the present embodiment is 0.5 or more, preferably 1 or more. If the drawing ratio is 0.5 or more, it is easy to fill the contents such as food, and if the drawing ratio is 1 or more, it becomes easy to hold by hand because it has a large capacity. It is easy to achieve the effect of achieving both mechanical strength and transparency.
The drawing ratio of the cup is expressed by (height of the cup)/(minor diameter of the opening). The minor diameter of the opening indicates the diameter if the opening is circular, the minor diameter if the opening is elliptical, the short side if the opening is rectangular, and the square if the opening is square. indicates the length of one side. For example, in the case of shape 1 in FIG. 1A, the drawing ratio is 51/75=0.68, and in the case of shape 2 in FIG. 1B, the drawing ratio is 137/96=1.4.

The polypropylene cup-shaped container of the present embodiment has a side haze value of 10% or less, preferably 5% or less. If the haze value is 10% or less, the contents can be clearly visually recognized, and if it is 5% or less, the visibility is even better.
In the present disclosure, the haze value is a value measured according to JIS K7136.

As a method for manufacturing the polypropylene cup-shaped container of the present embodiment, a plug-assist vacuum pressure molding method is preferable. The polypropylene sheet may be molded off-line after being wound once, or the extruded sheet may be directly molded in-line without winding.
The sheet molding method is not particularly limited, but as an example, the polypropylene sheet obtained by the above production method is heated offline or inline using an indirect heater to the softening point of polypropylene and then softened. , and formed into a cup shape by the vacuum pressure air method of the plug assist method. As a method for separating the molded cup portion and the non-molded portion of the sheet, either simultaneous punching during molding or providing a punching process after molding may be used.
When a polypropylene sheet is deep-drawn into a cup shape, the plug-assist method is preferably used. Although it is difficult to exhibit it, the kneading type antifogging agent of the present embodiment can provide good antifogging performance.
In addition, the surface of the sheet or cup may be subjected to corona treatment or plasma treatment in order to promote bleeding out of the antifogging agent.

EXAMPLES The present invention will be described below based on examples. The evaluation methods for various physical properties and the resins used are as follows.

Uneven thickness (thickness distribution)
For the 800 mm wide sheets extruded in Examples , Reference Examples , and Comparative Examples, the thickness distribution of 700 mm width excluding 50 mm widths on both sides was measured at intervals of 100 mm. This measurement was performed 10 times at intervals of 50 m in length to measure the thickness distribution for 500 m.
(Evaluation criteria)
○ (excellent): the range of thickness distribution is less than ±10% with respect to the center value × (poor): the range of thickness distribution is ±10% or more with respect to the center value.

The 800 mm wide sheets extruded in the blocking properties Examples , Reference Examples and Comparative Examples were wound up to a length of 500 m. The roll was placed at 40°C for 1 week to accelerate the bleed out of the antifoggant. After that, the sheet was unwound from the roll.
◯ (excellent): No blocking occurs, and the sheet can be fed out to the end of 500 m.
x (defective): Blocking occurred on the way, and it was not possible to pay out to the end of 500 m.

It was calculated by drawing ratio (cup height)/(minor diameter of opening).

Haze value (%)
Sampling was performed at three locations on the sides of the cup-shaped containers obtained in Examples , Reference Examples , and Comparative Examples so that the central portion in the height direction was the central portion for haze value measurement, and the following was performed in accordance with JIS K7136. It was measured using a measuring instrument and an average value was obtained.
Measuring instrument: Haze Meter NDH4000 manufactured by NIPPON DENSHOKU

A container filled with hot water at 80°C, which is 70% of the capacity, in an anti-fogging cup-shaped container, turned upside down so that the mouth of the empty container and the mouth of the container filled with hot water are aligned. placed on top of After 3 minutes, the cloudiness of the empty container was evaluated.
(Evaluation criteria)
◎ (excellent): 80% or more of the surface area of the empty container is not clouded ○ (slightly excellent): 50% or more and less than 80% of the surface area of the empty container is not clouded △ (good): 20% or more of the surface area of the empty container 5 Less than 10% is not clouded × (bad): Less than 20% of the surface area of the empty container is not clouded

Resin used Random PP (r-PP): E-333GV (MFR = 2.4) manufactured by Prime Polymer Co., Ltd.
・ Homo PP (h-PP): F-300SP (MFR = 3.0) manufactured by Prime Polymer Co., Ltd.

Preparation of Antifogging Agent Masterbatch A co -rotating twin-screw extruder with a screw diameter of 30 mm and L/D=40 was used to prepare an antifogging agent masterbatch. Random PP (E-333GV) manufactured by Prime Polymer Co., Ltd. was used as the base resin of the masterbatch, and the content of the antifogging agent in the masterbatch was adjusted to 10% by mass.
Seven types of antifogging agent masterbatches A to G were prepared with the compositions (weight ratios) shown in Table 1. In the antifogging agent masterbatch F, undecyldiethanolamide described in Example 1 of JP-A-10-67867 was used as the antifogging agent.

[ Reference example 1]
Random PP and antifogging agent masterbatch A were dry blended so that the content of the antifogging agent was 0.5% by mass (5% by mass as the content of the masterbatch). The mixture was kneaded and extruded on a D35 co-rotating twin-screw extruder at a temperature of 200°C. A monolayer sheet with a width of 800 mm and a thickness of 1.3 mm was extruded from a T-die, cooled with a chill roll at 50° C., and wound up to a length of 1000 m. Next, the sheet was unrolled, heated to near the softening point of polypropylene with an indirect IR heater, and cup-shaped in shape 1 (Fig. 1(a), drawing ratio: 0.68) by the vacuum pressure air plug assist method. molded into The molded part and the non-molded part of the sheet were separated by punching at the same time during molding.
Table 2 below shows the evaluation results of each example , reference example , and comparative example.

[ Reference example 2]
A sheet and a cup were produced in the same manner as in Reference Example 1, except that the sheet was molded into a cup shape of shape 2 (Fig. 1(b), drawing ratio: 1.4).

[ Reference example 3]
The first layer is a resin obtained by dry blending random PP and antifogging agent masterbatch A so that the content of the antifogging agent is 0.5% by mass (5% by mass as the content of the masterbatch). The mixture was kneaded and extruded at a temperature of 200° C. using a co-rotating twin-screw extruder with a diameter of 40 mmφ and L/D=35. For the second layer, a random PP resin was kneaded at a temperature of 200° C. with a short-screw extruder having a diameter of 40 mmφ and L/D=35, and extruded. Both layers are adjusted by the feed port block method so that the thickness ratio of the first layer and the second layer is first layer: second layer = 1: 5, and a two-layer sheet with a thickness of 800 mm and a width of 800 mm is obtained from a T die. After extrusion and chill roll cooling at 50° C., a 1000 m length was wound up. Next, the sheet was unwound, heated to near the softening point by an IR heater for indirect heating, and formed into a cup shape of Shape 1 by a vacuum pressure air plug assist method. The molded part and the non-molded part of the sheet were separated by punching at the same time during molding.

[Example 4]
The content of the anti-fogging agent in the second layer is 0.2% by mass (2% by mass as the content of the masterbatch), and the thickness ratio is the first layer: the second layer = 1:7, and the cup shape is formed. A sheet and a cup were produced in the same manner as in Example 3, except that 2 was used.

[ Reference Example 5]
The content of the antifogging agent in the first layer is 0.6% by mass (6% by mass as the content of the masterbatch), and the thickness ratio is the first layer: the second layer = 1:9, and the cup shape is formed. A sheet and a cup were produced in the same manner as in Reference Example 3, except that 2 was used.

[ Reference Example 6]
For the first layer, random PP and antifogging agent masterbatch B are adjusted so that the content of the antifogging agent is 0.5% by mass (5% by mass as the content of the masterbatch), and the cup shape is shaped. A sheet and a cup were produced in the same manner as in Reference Example 3, except that 2 was used.

[ Reference Example 7]
For the first layer, random PP and antifogging agent masterbatch C are adjusted so that the content of the antifogging agent is 0.5% by mass (5% by mass as the content of the masterbatch), and the cup shape is formed. A sheet and a cup were produced in the same manner as in Reference Example 3, except that 2 was used.

[Comparative Example 1]
For the first layer, random PP and antifogging agent masterbatch D are adjusted so that the content of the antifogging agent is 0.5% by mass (5% by mass as the content of the masterbatch), and the cup shape is shaped. A sheet and a cup were produced in the same manner as in Reference Example 3, except that 2 was used.

[Comparative Example 2]
For the first layer, random PP and antifogging agent masterbatch E are adjusted so that the content of the antifogging agent is 0.5% by mass (5% by mass as the content of the masterbatch), and the cup shape is formed. A sheet and a cup were produced in the same manner as in Reference Example 3, except that 2 was used.

[Comparative Example 3]
For the first layer, random PP and antifogging agent masterbatch F are adjusted so that the content of the antifogging agent is 0.5% by mass (5% by mass as the content of the masterbatch), and the cup shape is formed. A sheet and a cup were produced in the same manner as in Reference Example 3, except that 2 was used.

[Comparative Example 4]
A sheet and a cup were produced in the same manner as in Reference Example 1, except that the cup shape of Shape 2 was used using the antifogging agent masterbatch F.

[ Reference Example 8]
A sheet and a cup were produced in the same manner as in Reference Example 3, except that homo-PP was used for the second layer and the cup shape of Shape 2 was used.

[Comparative Example 5]
The first layer is random PP and the antifogging agent masterbatch E is adjusted so that the content of the antifogging agent is 0.6% by mass (6% by mass as the content of the masterbatch). A sheet and a cup were produced in the same manner as in Reference Example 1 except that they were shaped.
The sheet had large thickness unevenness and blocking occurred.

[Comparative Example 6]
The thickness ratio of the first layer: the second layer = 1: 9, the content of the antifogging agent A in the first layer was 0.4% by mass (4% by mass as the content of the masterbatch), and the cup shape was A sheet and a cup were produced in the same manner as in Reference Example 3 except that Shape 2 was used.

[ Reference Example 9]
A sheet and a cup were produced in the same manner as in Reference Example 3 except that the sheet thickness was 0.6 mm and the cup shape was changed to shape 2.

[ Reference Example 10]
A sheet and a cup were produced in the same manner as in Reference Example 3 except that the sheet thickness was 2.9 mm and the cup shape was changed to shape 2.

[ Reference Example 11]
A sheet and a cup were produced in the same manner as in Reference Example 3, except that the antifogging agent masterbatch G was used and the shape of the cup was changed to Shape 2.

The present invention provides a polypropylene sheet having a small uneven thickness and reduced blocking without impairing the properties of polypropylene, and a polypropylene cup which is a deep-drawn molded product that exhibits excellent anti-fogging properties and has good visibility of the contents. Since a mold container can be provided, it can be suitably used for deep-drawn containers for foods and drinks.

Claims (5)

A polypropylene sheet comprising at least a first layer and a second layer,
wherein said first layer and said second layer comprise an antifogging agent and polypropylene;
The antifog agent contains 40 to 80% by mass of alkyldiethanolamine, 10 to 50% by mass of glycerin fatty acid ester, and 5 to 20% by mass of polyethylene glycol alkylate,
Each layer containing the antifogging agent and the polypropylene contains 0.05 to 0.5% by mass of the antifogging agent,
The content (% by mass) of the antifogging agent in the first layer is greater than the content (% by mass) of the antifogging agent in the second layer,
The polypropylene sheet has a thickness of 0.5 to 3 mm
An antifogging polypropylene sheet characterized by: The first layer has a thickness of 0.05 to 1.5 mm,
The second layer has a thickness of 0.25 to 2.7 mm,
2. The antifogging polypropylene sheet according to claim 1, wherein the thickness ratio between the first layer and the second layer (first layer:second layer) is from 1:1 to 1:9. 3. An anti-fogging polypropylene cup-shaped container comprising the anti-fogging polypropylene sheet according to claim 1 or 2 , having a drawing ratio of 0.5 or more and a side haze value of 10% or less. 4. The anti-fog polypropylene cup-shaped container according to claim 3 , wherein said first layer of said anti-fog polypropylene sheet is an inner surface. 5. The method for producing an antifogging polypropylene cup-shaped container according to claim 3 or 4 , wherein a plug-assist method is used.

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