TWI818000B - Polypropylene resin sheet, method for producing polypropylene resin sheet, and resin container - Google Patents

Abstract

An object of the present invention is to provide a polypropylene resin sheet and a resin container which are excellent in transparency and shock resistance.

The polypropylene resin sheet and the resin container are formed of polypropylene resin composition including homopolypropylene and random polypropylene that have a certain relationship in value of melt mass-flow rate.

Description

Polypropylene resin sheet, method for producing polypropylene resin sheet, and resin container

The present invention relates to a polypropylene resin sheet, a method for producing a polypropylene resin sheet, and a resin container.

Conventionally, a resin container including a container body and a lid has been widely used as a container for packaging food and the like. The container body is provided with an opening in the upper part, and the lid closes the opening.

Conventionally, the container body of such a resin container has been mostly formed of a resin sheet that can be mass-produced.

For the lid of such a resin container, a top sealing material composed of polymer-coated paper, a transparent resin sheet, or the like has conventionally been used.

That is, there is known a resin container of this type in which the top sealing material is heat-sealed around the opening of the container body to seal the food inside.

In this type of container, it is required to ensure good visibility of the contents, and use specific A transparent resin sheet having excellent anti-fogging properties is used as a top sealing material (see Patent Document 1 below).

In such containers, the top sealing material may have the product name and description of the contents printed on it, or may have patterns or logos printed on it. In this case, it is difficult to see the contents through the top sealing material, so the container body also has Situations where transparency is required.

[Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2018-070191

Since the polypropylene-based resin sheet has excellent heat resistance, it is widely used as a material for forming the container body of the above-mentioned resin container.

When the crystal size of the polypropylene resin in the polypropylene resin sheet increases, the transparency is likely to decrease. Even with the same degree of crystallization, those having many fine crystals are more likely to be advantageous in terms of exhibiting transparency.

Therefore, in applications where transparency is required, the polypropylene-based resin composition constituting the polypropylene-based resin sheet may contain a crystal nucleating agent.

However, when the crystals of the polypropylene-based resin sheet are refined, the proportion of the crystals in the entire sheet becomes high, resulting in loss of flexibility and difficulty in ensuring sufficient impact resistance.

Therefore, when a polypropylene-based resin sheet is used to constitute the container body of a resin container, it may be difficult to achieve both excellent transparency and excellent impact resistance, and the polypropylene-based resin sheet is It is required to have both excellent transparency and excellent impact resistance.

The polypropylene resin sheet is required to have both excellent transparency and excellent impact resistance, not only when the polypropylene resin sheet is used as a constituent material of a resin container.

Under such circumstances, no means has been found to enable the polypropylene-based resin sheet to exhibit excellent transparency and impact resistance.

Therefore, the subject of the present invention is to satisfy this requirement.

In order to solve the above problems, the present invention provides a polypropylene-based resin sheet, which is a polypropylene-based resin sheet composed of a polypropylene-based resin composition containing a polypropylene-based resin and has a haze of 25% or less. The aforementioned polypropylene-based resin sheet The resin composition contains homopolypropylene and atactic polypropylene, and the ratio of the homopolypropylene to the total amount of the homopolypropylene and the atactic polypropylene is 50 mass% or more and 95 mass% or less. , and the difference between the melt mass flow rate of the homopolypropylene measured at a temperature of 230°C and a load of 2.16kg and the melt mass flow rate of the atactic polypropylene is 0.6g/10min or more and 6.0g/10min the following.

In order to solve the above problems, the present invention provides a method for manufacturing a polypropylene resin sheet, which implements the following steps to manufacture a polypropylene resin sheet with a haze of 25% or less. The method for manufacturing a polypropylene resin sheet includes: The kneading step is to use an extruder to knead the polypropylene-based resin composition containing the polypropylene-based resin while heating to obtain a molten kneaded product; and the extrusion step is to convert the aforementioned molten kneaded product from the device The polypropylene resin sheet is obtained by extruding it into a thin sheet through the die of the extruder; the polypropylene resin composition used in the kneading step contains homopolymer polypropylene and random polypropylene. Polypropylene in the aforementioned homopolymer polypropylene The ratio to the total amount of the atactic polypropylene is 50 mass % or more and 95 mass % or less, and the melt mass flow rate of the homopolymer polypropylene measured at a temperature of 230°C and a load of 2.16 kg is not the same as the above. The difference in the melt mass flow rate of the conventional polypropylene is 0.6 g/10 min or more and 6.0 g/10 min or less.

In order to solve the above-mentioned problems, the present invention provides a resin container including a container body provided with an opening in the upper part, and a lid closing the opening, wherein at least one of the container body and the lid is made of mist. The polypropylene resin sheet is composed of a polypropylene resin composition containing a polypropylene resin, and the polypropylene resin composition contains a homopolymerized polypropylene. and random polypropylene, and when it is made into a polypropylene-based resin sheet with a thickness of 0.4mm, the total absorbed energy measured by the drop weight impact test is 1.0J or more, and the bending rigidity is 40gf. cm ² /cm or more and 100gf． cm ² /cm or less.

1‧‧‧Resin container

10‧‧‧Container body

10a‧‧‧Opening part

10b‧‧‧Bottom face

10f‧‧‧Flange part

10w‧‧‧Peripheral side wall

20‧‧‧Lid

100, 100’‧‧‧polypropylene resin sheet

CL‧‧‧Cooling Equipment

E1‧‧‧Extruder

EX‧‧‧Manufacturing Equipment

FD‧‧‧Flat mold

HP‧‧‧Hopper

MD‧‧‧Extrusion direction

R0‧‧‧Roller

R1‧‧‧No.1 cooling roller (roller)

R2‧‧‧2nd cooling roller

TD‧‧‧Direction perpendicular to the flow direction

X‧‧‧Contained objects

Figure 1 is a schematic perspective view of a resin container with a container body and a lid.

Figure 2 is a schematic cross-sectional view of the resin container (arrow cross-sectional view along line A-A' in Figure 1).

Figure 3 is a schematic front view showing a polypropylene resin sheet manufacturing equipment.

Figure 4 is a schematic top view showing the manufacturing equipment of the polypropylene resin sheet.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Hereinafter, embodiments of the present invention will be described using a polypropylene-based resin sheet as a constituent material of the container body of a resin container as an example.

First, a resin container will be described with reference to Figures 1 and 2 .

As shown in these figures, the resin container 1 is composed of a resin container body 10 that stores a stored object X such as food, and a lid 20 that seals the stored object X.

More specifically, the resin container 1 is provided with a container body 10 and a lid 20. The container body 10 is provided with an opening 10a at the upper part; and the lid 20 closes the opening 10a; the container body 10 and the lid 20 are provided. 20, the container body 10 is made of a polypropylene resin sheet.

In the present embodiment, the container body 10 described above is a molded product having a three-dimensional structure by thermoforming a flat polypropylene resin sheet.

The container body 10 is a molded product that can be manufactured by thermoforming such as vacuum forming, pressure forming, vacuum/pressure forming, multi-mold forming, compression forming, or the like.

In this embodiment, the lid 20 is configured using a flat top sealing material.

In this embodiment, the lid 20 is constructed using the top sealing material, and the top sealing material is heat-sealed to the container body 10 and then attached to the container body 10 .

The container body 10 is provided with a substantially square bottom surface 10b and a peripheral side wall 10w standing along the outer periphery of the bottom surface 10b. The inner side of the bottom surface 10b and the peripheral side wall 10w is used to store the storage object X. A roughly rectangular-shaped storage space.

The opening 10a of the container body 10 is defined by the upper edge of the peripheral side wall 10w so that its outline shape becomes a square.

The container body 10 has a flange portion 10f extending outward from the upper end portion of the peripheral side wall 10w.

The flange portion 10f is provided to surround the opening 10a and has a substantially constant width to surround the opening 10a.

Therefore, the outline of the container body 10 in plan view defined by the outer edge of the flange portion 10f becomes a square that is larger than the opening 10a.

The lid 20 is constructed using a top sealing material having a shape corresponding to the outer edge shape of the flange portion 10f, and is attached to the container body in a state where the outer edge of the flange portion 10f and the outer edge of the top sealing material are aligned. 10.

More specifically, the lid 20 is attached to the container body 10 in a state in which the opening 10a is closed by thermally bonding the outer peripheral portion of the top sealing material to the upper surface of the flange portion 10f.

Next, the polypropylene resin sheet constituting the container body 10 will be described.

The container body 10 is formed by using a single-layer polypropylene resin sheet composed of a polypropylene resin composition containing polypropylene resin.

The polypropylene resin sheet may also be subjected to surface treatments such as anti-fog treatment, mold release treatment, and antibacterial treatment.

Considering the workability when manufacturing a molded article by thermoforming or the like, the polypropylene-based resin sheet of this embodiment usually has a thickness of 0.05 mm or more and 0.8 mm or less.

The thickness of the polypropylene resin sheet is preferably 0.7mm or less, and more preferably 0.6mm or less. 0.5mm or less is particularly preferred.

The thickness of the polypropylene resin sheet is preferably 0.10 mm or more, more preferably 0.15 mm or more, and more preferably 0.20 mm or more.

In this embodiment, it is also preferable that the container body 10 has the thickness as described above.

The thickness of the polypropylene-based resin sheet in the flat state before forming the molded article is determined by the arithmetic mean of the measured values at a plurality of arbitrarily selected locations (for example, 10 locations).

The thickness of the container body 10 can also be obtained in the same manner.

That is, the thickness of the polypropylene resin sheet and the thickness of the container body 10 in this embodiment mean the average thickness.

The thickness of the polypropylene resin sheet and the container body 10 can be determined using a micrometer, for example.

However, the measurement is performed in the same test environment (temperature 20±2°C, relative humidity 65±5%) after conditioning the sample for more than 24 hours. .

When the container body has fine irregularities such as ribs formed on one surface, it may be difficult for a micrometer to perform accurate measurement.

As another method for determining the average thickness of the polypropylene resin sheet and the container body 10, for example, the polypropylene resin sheet is cut into a predetermined size to produce a measurement sample, and the area of the measurement sample (A : cm ² ), mass (M: g), and density (ρ: g/cm ³ ) of the polypropylene resin sheet.

Specifically, the average thickness (t: mm) of the polypropylene-based resin sheet can be calculated according to the following formula (1) And ask for it.

t=[(M/ρ)/A]×10. ． ． (1)

The density of the polypropylene-based resin sheet can be determined by method A (water substitution method) based on JIS K7112: 1999 "Plastics - Determination of density and specific gravity of non-foamed plastics".

Regarding the container body 10 , the average thickness can also be determined in the same manner as the polypropylene resin sheet by determining the surface area, mass, and density of the outer surface.

The surface area of the container body 10 can be determined using a three-dimensional measuring instrument or the like.

In order to be advantageous in forming the container body 10 with excellent transparency, the haze value of the polypropylene resin sheet of this embodiment is 25% or less.

The haze is preferably 23% or less, more preferably 21% or less, more preferably 19% or less, and particularly preferably 17% or less.

In addition, when the haze of the polypropylene-based resin sheet is to be excessively reduced, the manufacturing method of the polypropylene-based resin sheet may be limited to a special one.

Therefore, in order to easily produce a polypropylene-based resin sheet, the haze is preferably 1% or more, and more preferably 5% or more.

It is preferable that not only the polypropylene-based resin sheet before molding but also the container body 10 after being in the state of the container body 10 have the above-mentioned haze value.

It is preferable that the entirety of the polypropylene resin sheet and the container body exhibit the above-mentioned haze within the above-mentioned preferable average thickness range.

The haze of the polypropylene resin sheet, the container body 10, etc. can be measured according to the method described in JIS K7136: 2000 "Plastics - Method for determining haze of transparent materials."

Specifically, the haze can be measured using a square sample with one side of 50 mm taken from a polypropylene resin sheet, the container body 10, or the like.

The measurement was performed using the haze meter HM-150 type (manufactured by Murakami Color Technology Research Institute, Inc.) and using the aforementioned sample and light source (D65).

In principle, the number of tests at this time is set to three and the arithmetic mean is used as the haze value.

However, the measurement is performed in the same test environment (temperature 20±2°C, relative humidity 65±5%) after conditioning the sample for more than 24 hours. .

Moreover, the haze system can be obtained according to the following formula (2).

Haze (%)={(τ4/τ2)-τ3(τ2/τ1)}×100． ． ． (2)

The meanings of each symbol in this formula (1) are as follows.

τ1: Beam of incident light

τ2: Full beam after transmitting the test piece

τ3: Full beam after device diffusion

τ4: Full beam after diffusion by device and test piece

The polypropylene resin sheet and the container body 10 preferably have not only excellent transparency as mentioned above, but also excellent impact resistance.

Specifically, the value of the total absorbed energy obtained when the polypropylene resin sheet and the container body 10 are subjected to a drop weight impact test is preferably 1.0 J or more.

The value of the total absorbed energy of the polypropylene resin sheet and the container body 10 is preferably 1.2 J or more, more preferably 1.5 J or more, and particularly preferably 2.0 J or more.

In addition, the total energy absorbed by the polypropylene resin sheet and the container body 10 is usually 4J or less. value.

It is preferable that the entirety of the polypropylene-based resin sheet and the container body exhibit the above-described total energy absorption within the above-mentioned preferable average thickness range.

The aforementioned total absorbed energy system can be obtained using the method shown below.

(Measurement method of total absorbed energy)

The fully absorbed energy system can be absorbed by the falling weight in accordance with ASTM D-3763-92 (Standard Test Method for High Speed Puncture Properties of Plastics Using Load and Displacement Sensors) The impact test is performed as follows.

That is, the size of the test piece is set to length 100 mm×width 100 mm×original thickness (thickness of the sheet obtained by extrusion molding).

The total absorbed energy (J) when the drop weight perforates the test piece was measured using the falling weight impact test device CEAST9350 (manufactured by CEAST Corporation) and the measurement software CEAST VIEW.

The test conditions etc. are usually as follows.

76mm、使用的錘頭為壓電式4.5kN檢測儀表化錘頭且前端形狀為

12.7mm半球型的錘頭插件、落下高度(止動器位置)：56cm、落錘距離：12cm、試驗溫度23℃、試驗數：6。 Test speed: 1.75m/sec, falling weight load: 1.926kg, no additional weight, test piece support spacing

76mm, the hammer head used is a piezoelectric 4.5kN detection instrumented hammer head and the shape of the front end is

12.7mm hemispherical hammer head insert, drop height (stopper position): 56cm, drop distance: 12cm, test temperature 23°C, number of tests: 6.

The test piece with a test temperature of 23°C was performed in accordance with Procedure A of ASTM D618-13 and was conditioned for more than 40 hours in an environment of 23±2°C and a relative humidity of 50±10% before measurement, and then conducted in the same standard environment. Determination.

The total absorbed energy system allows the integrated value of the graph obtained by the measurement to be Calculated by automatic calculation of settings.

In order to enable the molded article composed of the polypropylene resin sheet to exhibit excellent strength, the polypropylene resin sheet in this embodiment preferably has a predetermined bending rigidity within the above-mentioned preferred average thickness range.

In the polypropylene-based resin sheet of this embodiment, the bending rigidity (characteristic value B) measured using, for example, a bending testing machine commercially available under the trade name "KES FB2-L" from KATO TECH Co., Ltd. showed 40 gf. Values above cm ² /cm are preferred.

The value of the bending rigidity is based on 45gf. cm ² /cm or above is preferred, with 50gf. cm ² /cm or above is particularly good.

The value of this bending rigidity is usually 100gf. cm ² /cm or less.

The bending rigidity can be measured as follows, for example.

(Measurement method of bending rigidity)

Cut out a rectangular test piece with a length of 100 mm and a width of 10 mm at three randomly selected locations on the polypropylene resin sheet.

In addition, the three test pieces were set so that their longitudinal directions were in the same direction and in a direction perpendicular to the resin discharge direction (MD direction) during extrusion of the polypropylene resin sheet (TD direction).

Prepare a bending testing machine (for example, KATO TECH Co., Ltd., large-scale pure bending testing machine, trade name "KES FB2-L"), and use a fixed arm and a movable arm to position each of the longitudinal ends of each test piece with an inter-arm distance of 40mm. The movable arm is controlled in a certain way, and under the measurement conditions of curvature 0.5cm ^-1 and bending speed 0.1cm ^-1 /sec, the movable arm is moved once each to the surface direction and back direction of the test piece, and from the detected rotation The bending rigidity (characteristic value B) of each test piece was calculated using the moment, and the arithmetic mean value of the bending rigidity (characteristic value B) of each test piece was taken as the bending rigidity of the polypropylene-based resin sheet.

When the container body 10 has a complicated shape and it is difficult to accurately measure the bending rigidity and total energy absorption, the container body 10 can also be hot-pressed, or the polypropylene resin composition constituting the container body can be manufactured to a predetermined thickness (for example, 0.4 mm) polypropylene resin sheet, and using this polypropylene resin sheet as a measurement sample, the bending rigidity and total absorbed energy of the container body 10 were determined.

It is preferable that the container body 10 of this embodiment also exhibits good characteristic values in terms of the above-mentioned bending rigidity and total absorbed energy in the measurement of such a polypropylene-based resin sheet.

In order for the polypropylene-based resin sheet and the container body 10 to exhibit the above-described characteristics, it is preferable to adjust the polypropylene-based resin sheet and the container body 10 so that the crystals of the polypropylene in the polypropylene-based resin sheet and the container body 10 are refined and the crystals are formed in the polypropylene. The ratio of the resin sheet to the container body 10 is not excessively high.

In order to provide the polypropylene-based resin sheet and the container body 10 with strength such as rigidity, among the polypropylene-based resin compositions constituting the polypropylene-based resin sheet and the container body 10, the polypropylene-based resin serving as the matrix polymer Homopolymer polypropylene is preferred.

However, when the polypropylene-based resin contained in the polypropylene-based resin composition is only homopolymerized polypropylene, the crystallization ratio in the process of manufacturing the polypropylene-based resin sheet and the container body 10 may be too high, making it difficult to exhibit good impact resistance. sexual situation.

Therefore, the polypropylene-based resin composition preferably contains both homopolypropylene and atactic polypropylene.

That is, in this embodiment, the polypropylene resin composition constituting the polypropylene resin sheet and the container body 10 contains homopolypropylene and random polypropylene as the polypropylene resin.

The aforementioned homopolymerized polypropylene precedes the polypropylene-based resin composition. The proportion of the total amount of the aforementioned random polypropylene is preferably 50% by mass or more.

The aforementioned ratio of the homopolymerized polypropylene is preferably 55 mass% or more, more preferably 60 mass% or more, and particularly preferably 65 mass% or more.

The ratio of the homopolypropylene is preferably 95 mass% or less, more preferably 90 mass% or less, more preferably 85 mass% or less, and particularly preferably 80 mass% or less.

When the ratio is within the above range, a polypropylene resin sheet having excellent impact resistance, transparency, and bending rigidity can be obtained.

When the aforementioned polypropylene-based resin composition contains another polymer in addition to homopolypropylene and random polypropylene, the polypropylene-based resin sheet and the container body 10 may not be able to exhibit sufficiently good transparency. The content of the other polymer is preferably 5% by mass or less.

The content of the other polymer is preferably 4% by mass or less, more preferably 3% by mass or less.

It is particularly preferred that the polypropylene-based resin composition contains no other polymers other than homopolypropylene and atactic polypropylene.

In order for the polypropylene-based resin sheet and the container body 10 to exhibit excellent transparency and excellent impact resistance, it is preferred that the random polypropylene-based resin and the homopolymerized polypropylene exist in a good dispersed state.

In order to bring the random polypropylene into a good dispersion state, it is preferable that the melt mass flow rate of the random polypropylene and the melt mass flow rate of the homopolypropylene have a predetermined relationship.

Specifically, the aforementioned homopolymer polypropylene was measured at a temperature of 230°C and a load of 2.16kg. The difference between the specified melt mass flow rate and the aforementioned melt mass flow rate of the atactic polypropylene is preferably 0.6g/10min or more and 6.0g/10min or less.

When the difference in melt mass flow rates is within the above range, a polypropylene resin sheet having excellent impact resistance, transparency, and bending rigidity can be obtained.

In addition, the so-called "difference in melt mass flow rate" means the absolute value of the difference between the melt mass flow rate of homopolypropylene and the melt mass flow rate of atactic polypropylene, and means which of the two The difference when a lower value is subtracted from a higher value.

That is, it means that when the difference in melt mass flow rate is 0.6g/10min or more and 6.0g/10min or less, the melt mass flow rate of homopolypropylene is set to "MFRh (g/10min)", and When the melt mass flow rate of atactic polypropylene is "MFRr (g/10min)", the following formula (3) is satisfied.

0.6≦|MFRh-MFRr|≦6.0． ． ． (3)

The difference in melt mass flow rate is preferably 0.7g/10min or more, and more preferably 0.8g/10min or more.

The difference in melt mass flow rate is preferably 5.5g/10min or less, more preferably 5.0g/10min or less, and particularly preferably 4.5g/10min or less.

The melt mass flow rate (MFRh) of the homopolymer polypropylene is preferably 1.0g/10min or more, and more preferably 1.5g/10min or more.

The melt mass flow rate (MFRh) of the homopolymer polypropylene is preferably 5.0g/10min or less, and more preferably 4.0g/10min or less.

The melt mass flow rate (MFR) system can use SEMI-AUTO MELT INDEXER2A manufactured by Toyo Seiki Co., Ltd. and is based on JIS K7210: 1999 "Plastic Glue - Test method for melt mass flow rate (MFR) and melt volume flow rate (melt volume-flow rate: MVR) of thermoplastics" "b) Method for measuring the time for the piston to move a predetermined distance" described in Method B Determination.

At this time, the measurement conditions are set as follows in principle.

Sample amount: 3 to 8g

Warm-up time: 270 seconds

Load holding: 30 seconds

Test temperature: 230℃

Test load: 21.18N

In addition, the number of times of testing of the sample was set to three times, and the average was set as the value of the melt mass flow rate (g/10 min).

In this embodiment, it is not necessary to use one type of homopolypropylene alone, and two or more types of homopolypropylene may be blended and used.

When the polypropylene-based resin composition contains a plurality of types of homopolymerized polypropylene, the melt mass flow rate (MFRh) of the homopolymerized polypropylene can be determined by calculating the average value of the mass ratios.

For example, when the polypropylene-based resin composition contains n types of homopolymerized polypropylene, let the mass ratio of the first homopolymerized polypropylene in the total amount of homopolymerized polypropylene be "a1 (%)", and let The melt mass flow rate of 1st homopolymerized polypropylene is set to "MFRh1 (g/10min)", the mass ratio of the 2nd homopolymerized polypropylene is set to "a2 (%)", and the melt mass flow rate of the 2nd homopolymerized polypropylene is set to "a2 (%)". The bulk mass flow rate is set to "MFRh2 (g/10min)", the mass ratio of the nth homopolypropylene is set to "an (%)", and the melt mass flow rate of the nth homopolypropylene is set to " MFRhn (g/10min)", the melt mass flow rate (MFRh) of homopolymer polypropylene can be determined according to the following formula.

MFRh=[MFRh1×a1+MFRh2×a2+. ． ． MFRhn×an]/100

There is no need to include a separate type of polypropylene-based resin composition, and the same applies not only to homopolymerized polypropylene but also to atactic polypropylene.

When the polypropylene-based resin composition contains n types of random polypropylene, let the mass ratio of the first random polypropylene in the total amount of random polypropylene be "b1 (%)", and let the first random polypropylene be "b1 (%)". Let the melt mass flow rate of regular polypropylene be "MFRr1 (g/10min)", let the mass ratio of the second atactic polypropylene be "b2 (%)", and let the melt mass of the second atactic polypropylene The flow rate is set to "MFRr2 (g/10min)", the mass ratio of the nth random polypropylene is set to "bn(%)", and the melt mass flow rate of the nth random polypropylene is set to "MFRrn( g/10min)", the melt mass flow rate (MFRr) of atactic polypropylene can be obtained according to the following formula.

MFRr=[MFRr1×b1+MFRr2×b2+. ． ． MFRrn×bn]/100

As the aforementioned random polypropylene, the content of comonomer components such as ethylene other than propylene is preferably 0.3% by mass or more and 6% by mass or less.

The content of the comonomer component is preferably 0.5% by mass or more.

The content of the comonomer component is preferably 5% by mass or less.

Compared with metallocene catalysts, the aforementioned random polypropylene is preferably a Ziegler-Natta catalyst whose molecular weight distribution tends to be broad.

The aforementioned random polypropylene may also contain α-olefin monomers such as 1-butene, 1-hexene, 1-octene, etc. as comonomer components other than ethylene, and 1-butene, etc. may be included together with ethylene. good.

The polypropylene resin composition constituting the polypropylene resin sheet and the container body 10 preferably contains a crystal nucleating agent so that the polypropylene resin sheet and the container body 10 can exhibit excellent transparency.

As the aforementioned crystal nucleating agent, a nucleating agent commonly used as a nucleating agent for improving the transparency of crystalline polymers can be used, and examples thereof include aromatic carboxylic acid metal salts such as p-tertiary butyl aluminum benzoate; 2,2'-Methylenebis(4,6-di-tertiary butylphenyl)sodium phosphate, 2,2'-methylenebis(4,6-di-tertiary butylphenyl)aluminum phosphate, etc. Aromatic phosphate metal salts; sugar alcohol derivatives, sorbitol derivatives, etc., such as hexitol derivatives, heptitol derivatives, octitol derivatives, nonitol derivatives, etc. Sugar alcohol derivatives; sodium salt of rosin and other metal salts of rosin, etc.

These nucleating agents can be used alone or in combination of multiple types.

The crystallization nucleating agent is preferably contained in the polypropylene-based resin composition at a ratio of 0.1 to 1.0 parts by mass based on 100 parts by mass of the polypropylene-based resin.

The content of the crystallization nucleating agent is preferably 0.2 parts by mass or more, and more preferably 0.3 parts by mass or more based on 100 parts by mass of the polypropylene resin.

The content of the crystallization nucleating agent is preferably 0.9 parts by mass or less, and more preferably 0.8 parts by mass or less based on 100 parts by mass of the polypropylene resin.

As the crystal nucleating agent as mentioned above, alditol derivatives are preferred, and nonitol derivatives are particularly preferred.

That is, the polypropylene-based resin composition preferably contains the nonitol-based derivative in a ratio of 0.1 parts by mass or more and 1.0 parts by mass or less based on 100 parts by mass of the polypropylene-based resin.

The aforementioned polypropylene resin composition may further contain common plastic additives such as a release agent, an antistatic agent, an antibacterial agent, and a weathering agent.

The polypropylene-based resin composition can be made into a polypropylene-based resin sheet by, for example, the equipment shown in FIGS. 3 and 4 .

The 3rd picture is a schematic front view of the equipment used to manufacture polypropylene resin sheets, and the 4th picture is Above image of the same device.

As shown in this figure, the polypropylene-based resin sheet manufacturing equipment EX in this embodiment is equipped with: an extruder E1 for melt-kneading the aforementioned polypropylene-based resin composition; and a flat die TD. , which is used to extrude the melt-kneaded product obtained by the melt-kneading of the extruder E1 into a sheet shape to obtain a polypropylene-based resin sheet.

The extruder E1 is equipped with a hopper HP for introducing the polypropylene resin composition on the base end side of the extrusion direction MD, and the flat die FD is installed in the extruder opposite to the hopper HP. The front end of E1.

In this embodiment, the flat die FD is installed at the front end in the extrusion direction MD to extrude the melt-kneaded material into a sheet shape.

The flat die FD has a linear discharge port. The extending direction of the discharge port is a horizontal direction and is arranged so that the discharge direction faces downward.

In this embodiment, the aforementioned manufacturing equipment EX is further equipped with a cooling device for cooling and solidifying the molten polypropylene-based resin sheet 100' discharged from the linear discharge port of the flat mold FD.

Specifically, the manufacturing equipment EX is equipped with a cooling device CL formed by arranging three rollers with parallel rotation axes in the horizontal direction.

The three rollers are arranged so that the discharge port of the flat die FD is parallel to the rotation axis, and are arranged below the flat die FD in the direction in which the molten kneaded product is extruded.

Among the three rollers, the central roller is a cooling roller R1 for cooling the melt-kneaded material extruded into a sheet shape. The melt-kneaded material (polypropylene-based resin sheet in a molten state 100') is extruded from the flat die FD to its outer peripheral surface, and the extruded polypropylene resin sheet 100' is closely adhered to the outer peripheral surface of the cooling roller R1 to cool the polypropylene resin sheet from one side. 100'.

The cooling roller R1 of the center roller is rotated so that the outer peripheral surface of the position located below the flat die FD is away from the flat die FD, and is arranged so as to pull the polypropylene resin sheet 100' with this rotation. .

In addition, a roller arranged adjacent to the cooling roller R1 on the downstream side of the cooling roller R1 in the flow direction of the sheet can also achieve the same function as the cooling roller R1. From the cooling roller The polypropylene resin sheet 100' with the outer circumferential surface of the side edge portion of the drum R1 peeled off is wound around the outer circumferential surface of the roller, and this roller can serve as the second cooling roller R2 (hereinafter also referred to as " The function of the second cooling roller R2") is to cool the polypropylene resin sheet 100' from the side opposite to the side cooled by the cooling roller R1.

Furthermore, the roller on the opposite side to the second cooling roller R2 and adjacent to the center roller is used to pass through the center cooling roller R1 (hereinafter also referred to as "the first cooling roller R1"). The thickness of the finally obtained polypropylene-based resin sheet 100 becomes a constant roller R0 (hereinafter also referred to as "thickness regulating roller R0").

The polypropylene resin sheet 100 manufactured using this manufacturing equipment EX is manufactured by adjusting the discharge amount from the extruder E1 and the rotation speed of the first cooling roller R1 (polypropylene resin sheet 100 The thickness is determined by the pulling speed) and the thickness is determined by the thickness-defining roller R0 so that the thickness does not vary.

Furthermore, when the polypropylene-based resin sheet 100 is extruded from the flat die FD, at least the central portion in the thickness direction is at a higher temperature than the melting points of random polypropylene and homopolypropylene. A cooling roller R1 comes into contact with the thickness-defining roller R0 and is rapidly cooled.

Therefore, in the present embodiment, the aforementioned manufacturing equipment EX can be controlled by adjusting the temperature setting of the extruder, the distance from the flat die FD to the first cooling roller R1, the first cooling roller R1, and the thickness regulating roller. The crystallization of the polypropylene resin sheet 100 is adjusted by adjusting the temperature of the cylinder R0 and the like.

As described above, the polypropylene resin sheet 100 is manufactured by a polypropylene resin sheet manufacturing method that carries out the following steps to manufacture the polypropylene resin sheet 100, including: a kneading step in which the extruder E1 is used to mix the polypropylene resin sheet containing A step of melt-kneading a polypropylene-based resin composition of a polypropylene-based resin to obtain a melt-kneaded product; and an extrusion step, which involves extruding the aforementioned melt-kneaded product from a die (flat die FD) installed in the aforementioned extruder E1. A step of extruding the kneaded material into a sheet shape to obtain a polypropylene resin sheet.

In the manufacturing method of the polypropylene-based resin sheet 100, the polypropylene-based resin composition used in the kneading step contains homopolymerized polypropylene and random polypropylene, and the aforementioned homopolymerized polypropylene is in the aforementioned homopolymerized polypropylene. The ratio to the total amount of the atactic polypropylene is 50 mass % or more and 95 mass % or less, and the melt mass flow rate of the homopolymer polypropylene measured at a temperature of 230°C and a load of 2.16 kg is consistent with the above The difference in the melt mass flow rates of atactic polypropylene is 0.6 g/10 min or more and 6.0 g/10 min or less.

In this embodiment, the polypropylene-based resin composition contains atactic polypropylene and homopolypropylene whose melt mass flow rates are close to each other. Therefore, inside the extruder E1, the atactic polypropylene-based and homopolymer-based polypropylene are Polypropylene shows good dispersibility, and the polypropylene-based resin sheet 100 after being discharged from the flat die FD does not undergo rapid crystallization.

Therefore, in the aforementioned extrusion step, acrylic resin sheets having excellent transparency with a haze of 25% or less can be easily produced.

In this embodiment, since the flat mold FD is used as the mold and the The extrusion step of extruding the molten kneaded material into a sheet form from the flat die FD is performed on the outer peripheral surface of the rotating roller (first cooling roller R1), and following the extrusion step, the roller is It is particularly easy to produce a polypropylene-based resin sheet having excellent transparency with a haze of 25% or less through the cooling step of the melt-kneaded material before being extruded into a sheet shape by the roller cooling.

In addition, the polypropylene-based resin sheet 100 of this embodiment can be produced not only by this method but also by various methods such as blow molding.

In order to manufacture the container body 10 using the polypropylene resin sheet 100 manufactured by the manufacturing equipment EX, in this embodiment, a vacuum forming method, a pressure forming method, a vacuum-pressure forming method, a multi-mold forming method, or Compression molding is a method commonly used in thermoforming.

In this embodiment, the polypropylene resin sheet 100 is used to form the container body 10. However, the polypropylene resin sheet 100 may also be used as a material for forming the lid.

In addition, the polypropylene-based resin sheet 100 can be used in a multi-layered manner as long as it satisfies required physical properties.

Furthermore, the polypropylene resin sheet 100 can be used in various applications in which transparency and impact resistance are required, in addition to being used as a container for storing objects X such as food.

That is, the present invention is not limited at all by the above examples.

[Example]

Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these Examples.

Verification results regarding the effects of the present invention are shown below.

<Verification 1>

(Comparative Example 1-1)

100 parts by mass of homopolypropylene (hPP1) (MFR: 3.0g/10min, impact strength (23°C, ASTM D256) 3.0kg.cm/cm) and 4 parts by mass of masterbatch (MB1) containing crystal nucleation agent The polypropylene-based resin composition is supplied to an extruder, melt-kneaded using the extruder, extruded using a flat die, and cooled and solidified by a cooling roller to produce a polypropylene-based resin sheet.

(base weigh)

A square sample with a side of 10 cm was cut out from the obtained polypropylene resin sheet, the mass was measured, and the basis weight (mass per 1 m ² ) was calculated by converting it into mass per 1 m ² .

(Evaluation of impact resistance)

The impact resistance of polypropylene resin sheets was evaluated using the falling weight impact test device CEAST9350.

The evaluation item is set to total absorbed energy (J).

(Transparency)

The haze of the polypropylene resin sheet was measured.

(bending rigidity)

The bending rigidity (characteristic value B) of the polypropylene-based resin sheet was determined using a bending testing machine (trade name "KES FB2-L") of KATO TECH Co., Ltd.

(Example 1-1)

50 parts by mass of the same homopolypropylene (hPP1) (MFR: 3.0g/10min) used in "Comparative Example 1-1" and random polypropylene (rPP1) (MFR: 1.2g/10min, impact strength (23℃, JIS K6921-2) 24.0kJ/m ² ) 50 parts by mass of the polypropylene resin composition are supplied to the extruder, and the extruder is used for melting and kneading using a flat die A polypropylene-based resin sheet was produced by extrusion and cooling and solidification with a cooling roller, and was evaluated in the same manner as the polypropylene-based resin sheet of "Comparative Example 1-1".

(Example 1-2)

Containing 50 parts by mass of the same homopolypropylene (hPP1) (MFR: 3.0g/10min) as used in "Comparative Example 1-1", and 50 parts by mass of the same homopolypropylene as used in "Example 1-1" 50 parts by mass of a polypropylene-based resin composition of random polypropylene (rPP2) (MFR: 2.3g/10min, impact strength (23°C, JIS K6921-2) 7.8kJ/m ² ) was supplied to the extruder, and used The extruder melt-kneaded and extruded using a flat die, and cooled and solidified with a cooling roller to produce a polypropylene-based resin sheet, and evaluated similarly to the polypropylene-based resin sheet of "Comparative Example 1-1".

The evaluation results of the polypropylene resin sheet produced in this verification 1 are shown in the following table.

As shown in the results, in "Example 1-1" and "Example 1-2" containing atactic polypropylene with a melt mass flow rate close to that of homopolymer polypropylene, no crystallization nucleating agent was used. Masterbatch, but compared to "Comparative Example 1-1" using a crystal nucleating agent masterbatch, the haze is only slightly increased and has excellent transparency.

Furthermore, compared to "Comparative Example 1-1", the total absorbed energy in "Example 1-1" and "Example 1-2" shows a value approximately 5 times greater.

That is, from this situation, it is understood that according to the present invention, the polypropylene-based resin sheet can exhibit excellent transparency, impact resistance, and bending rigidity.

<Verification 2>

(Comparative Example 2-1)

Homopolypropylene (hPP2) (MFR: 0.5g/10min, impact strength (23°C, JIS K6921-2) 8.2kJ/m ² ) different from verification 1 was melt-kneaded using an extruder and a flat die was used Extrusion is performed, and cooling and solidification are performed with a cooling roller to produce a polypropylene-based resin sheet.

(Comparative Example 2-2)

A polypropylene-based resin sheet was produced using the same crystal nucleating agent masterbatch (MB1) as in Verification 1 at a ratio of 2 parts by mass with respect to 100 parts by mass of homopolypropylene (hPP2).

The evaluation results of the polypropylene-based resin sheets produced in this verification 2 are shown in the following table.

From the table above, it is found that transparency and impact resistance are insufficient when random polypropylene is not blended.

<Verification 3>

(Example 3-1)

A random polypropylene containing 90 parts by mass of homopolypropylene (hPP3) (MFR: 3.0g/10min, impact strength (23°C, JIS K6921-2) 5.7kJ/m ² ) different from verification 1 and verification 2 (rPP3) (MFR: 1.3g/10min, impact strength (23°C, JIS K7111) 9.0kJ/m ² ) 10 parts by mass, and contains 2 parts by mass of the same crystal nucleation agent masterbatch (MB1) as in Verification 1 The propylene-based resin composition is supplied to an extruder, melt-kneaded using the extruder, extruded using a flat die, and cooled and solidified by a cooling roller to produce a polypropylene-based resin sheet.

(Example 3-2)

A polypropylene resin sheet was produced in the same manner as "Example 3-1" except that the ratio of homopolypropylene (hPP3) and random polypropylene (rPP3) was changed from 90:10 to 70:30.

(Example 3-3)

A polypropylene resin sheet was produced in the same manner as "Example 3-1" except that the ratio of homopolypropylene (hPP3) and random polypropylene (rPP3) was changed from 90:10 to 50:50.

(Comparative Example 3-1)

A polypropylene resin sheet was produced in the same manner as in "Example 3-1" except that the ratio of homopolypropylene (hPP3) and random polypropylene (rPP3) was changed from 90:10 to 30:70.

The evaluation results of the polypropylene-based resin sheets produced in this verification 3 are shown in the following table.

In the above table, as in the verification so far, the compound containing atactic polypropylene showed superior transparency and impact resistance compared to other compounds.

Furthermore, in the above table, it is found that when the blending amount of random polypropylene exceeds 50 parts by mass, the values of "total absorbed energy" and "bending rigidity" decrease, and the impact resistance and rigidity each begin to decrease.

<Verification 4>

(Example 4-1)

A random polypropylene containing 50 parts by mass of the same homopolypropylene (hPP1) (MFR: 3.0g/10min) as in Verification 1 but different from the atactic polypropylene used in the verification so far was prepared. A polypropylene-based resin composed of 50 parts by mass of propylene (rPP4) (MFR: 1.8g/10min, impact strength (23°C, ASTM D256) 6.0kg.cm/cm) and 2.0 parts by mass of crystal nucleation agent masterbatch (MB1) The material is supplied to the extruder, and the extruder is used for melting and kneading and a flat die is used for extrusion. The cooling roller is cooled and solidified to produce a polypropylene resin sheet.

(Example 4-2)

Except for changing the ratio of homopolypropylene (hPP1) (MFR: 3.0g/10min) and atactic polypropylene (rPP4) (MFR: 1.8g/10min)) from 50:50 to 70:30, it is the same as " Example 4-1" A polypropylene resin sheet was produced in the same manner.

(Example 4-3)

Except for changing the ratio of homopolypropylene (hPP1) (MFR: 3.0g/10min) and atactic polypropylene (rPP4) (MFR: 1.8g/10min)) from 50:50 to 80:20, it is the same as " Example 4-1" A polypropylene resin sheet was produced in the same manner.

(Example 4-4)

Except for changing the ratio of homopolypropylene (hPP1) (MFR: 3.0g/10min) and atactic polypropylene (rPP4) (MFR: 1.8g/10min)) from 50:50 to 90:10, it is the same as " Example 4-1" A polypropylene resin sheet was produced in the same manner.

The evaluation results of the polypropylene-based resin sheets produced in this verification 4 are shown in the following table.

From the results shown in this table, it is known that the impact resistance of the polypropylene-based resin sheet can be improved by containing random polypropylene.

<Verification 5>

(Example 5-1)

Containing 90 parts by mass of the same homopolypropylene (hPP3) (MFR: 3.0g/10min) as in Verification 3 and the same random polypropylene (rPP2) (MFR: 2.3) as in "Example 1-2" of Verification 1 g/10min) 10 parts by mass of the polypropylene resin composition and 2.0 parts by mass of the crystallization nucleating agent masterbatch (MB1) were supplied to the extruder, melt-kneaded using the extruder and extruded using a flat die. The cooling roller performs cooling and solidification to produce a polypropylene resin sheet.

(Example 5-2)

In addition to combining homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP2) (MFR: 2.3g/10min))) except that the ratio was changed from 90:10 to 70:30, a polypropylene-based resin sheet was produced in the same manner as "Example 5-1".

(Example 5-3)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP2) (MFR: 2.3g/10min)) from 90:10 to 50:50, it is the same as " Example 5-1" A polypropylene resin sheet was produced in the same manner.

(Comparative Example 5-1)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP2) (MFR: 2.3g/10min)) from 90:10 to 30:70, it is the same as " Example 5-1" A polypropylene resin sheet was produced in the same manner.

The evaluation results of the polypropylene-based resin sheets produced in this verification 5 are shown in the following table.

Same as the results obtained in Verification 3, it was found that when the blending amount of the random polypropylene in the above table exceeds 50 parts by mass, the values of "total absorbed energy" and "bending rigidity" decrease, and the impact resistance and rigidity decrease. Each began to decrease.

<Verification 6>

(Example 6-1)

It contains 90 parts by mass of the same homopolypropylene (hPP3) (MFR: 3.0g/10min) as verified in Verification 3 and Verification 5, and another random polypropylene (rPP5) (MFR: 5.8g/ 10 minutes, 10 parts by mass of impact strength (23°C, manufacturer's method) 20.0 kJ/m) and 2.0 parts by mass of crystal nucleation agent masterbatch (MB1) of the polypropylene resin composition are supplied to the extruder, and the extruder is used. The mixture is melt-kneaded and extruded using a flat die, and is cooled and solidified by a cooling roller to produce a polypropylene-based resin sheet.

(Example 6-2)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP5) (MFR: 5.8g/10min)) from 90:10 to 70:30, it is the same as " Example 6-1" A polypropylene resin sheet was produced in the same manner.

(Example 6-3)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP5) (MFR: 5.8g/10min)) from 90:10 to 50:50, it is the same as " Example 6-1" A polypropylene resin sheet was produced in the same manner.

(Comparative Example 6-1)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP5) (MFR: 5.8g/10min)) from 90:10 to 30:70, it is the same as " implement Example 6-1" A polypropylene resin sheet was produced in the same manner.

The evaluation results of the polypropylene-based resin sheets produced in this verification 6 are shown in the following table.

In this verification 6, unlike the verifications so far, the melt mass flow rate of atactic polypropylene is higher than that of homopolypropylene.

However, it was found that a polypropylene resin sheet having excellent transparency and impact resistance can be obtained by setting the melt mass flow rate within a predetermined range even in this case.

In addition, from the above table, it is found that when the blending amount of random polypropylene exceeds 50 parts by mass, the "haze" value increases and the transparency decreases, and the "bending rigidity" value also begins to decrease.

<Verification 7>

(Example 7-1)

Similar to Verification 6, verification was conducted using random polypropylene with a higher melt mass flow rate than homopolymer polypropylene.

Here, compared to the random polypropylene (rPP5) (MFR: 5.8g/10min) used in verification 6, atactic polypropylene (rPP6) (MFR: 7.0g/ 10min).

Specifically, the system contains 50 parts by mass of the same homopolypropylene (hPP3) (MFR: 3.0g/10min) as verified in Verification 3, Verification 5, and Verification 6, and another random polypropylene (which has been verified so far). rPP6) (MFR: 7.0g/10min, impact strength (23°C, manufacturer's method) 20.0KJ/m) 50 parts by mass and a polypropylene resin composition of 2.0 parts by mass of crystal nucleation agent masterbatch (MB1) were supplied to the extruder. The extruder is used for melt-kneading, the flat die is used for extrusion, and the polypropylene-based resin sheet is cooled and solidified by a cooling roller.

(Comparative Example 7-1)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP6) (MFR: 7.0g/10min)) from 50:50 to 30:70, it is the same as " Example 7-1" A polypropylene resin sheet was produced in the same manner.

The evaluation results of the polypropylene-based resin sheets produced in this verification 7 are shown in the following table.

In this verification 7, it was also found that when the blending amount of random polypropylene exceeds 50 parts by mass, the "haze" value increases and the transparency begins to decrease.

<Verification 8>

(Comparative Example 8-1)

Similar to Verification 6 and Verification 7, the verification was conducted using random polypropylene with a higher melt mass flow rate than homopolymer polypropylene.

Here, atactic polypropylene (rPP7) (MFR: 9.5g) with a higher melt mass flow rate than the atactic polypropylene (rPP6) (MFR: 7.0g/10min) used in Verification 7 was used. /10min, impact strength (23℃, JIS K6921-2) 4.9kJ/m ² ).

That is, the verification was performed here using homopolypropylene and random polypropylene whose melt mass flow rate difference is larger than 6.0 g/10 min.

Specifically, the system contains 90 parts by mass of the same homopolypropylene (hPP3) (MFR: 3.0g/10min) as in Verification 3, Verification 5, Verification 6, and Verification 7, and the verification up to this point is another random one. A polypropylene-based resin composition of 10 parts by mass of polypropylene (rPP7) (MFR: 9.5g/10min) and 2.0 parts by mass of a crystal nucleation agent masterbatch (MB1) was supplied to an extruder, and melt-kneading was performed using the extruder. Furthermore, a flat die is used for extrusion, and a polypropylene-based resin sheet is produced by cooling and solidifying with a cooling roller.

(Comparative Example 8-2)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP7) (MFR: 9.5g/10min)) from 90:10 to 70:30, it is the same as " Comparative Example 8-1" A polypropylene resin sheet was produced in the same manner.

(Comparative Example 8-3)

Except for changing the ratio of homopolypropylene (hPP3) (MFR: 3.0g/10min) and atactic polypropylene (rPP7) (MFR: 9.5g/10min)) from 90:10 to 50:50, it is the same as " Comparative Example 8-1" A polypropylene resin sheet was produced in the same manner.

The evaluation results of the polypropylene-based resin sheets produced in this verification 8 are shown in the table below.

In this verification 8, unlike the verifications up to this point, the effect of adding random polypropylene was not observed.

<Verification 9>

(Comparative Example 9-1)

Contrary to Verification 8, the verification was performed using homopolypropylene and atactic polypropylene with a small difference in melt mass flow rates.

Specifically, the system contains 90 parts by mass of homopolypropylene (hPP4) (MFR: 7.5g/10min, impact strength (23°C, JIS K6921-2) 4.0kJ/m ² ), the same random material as in Verification 7. A polypropylene-based resin composition of 10 parts by mass of polypropylene (rPP6) (MFR: 7.0g/10min) and 2.0 parts by mass of a crystal nucleation agent masterbatch (MB1) was supplied to an extruder, and melt-kneading was performed using the extruder. Furthermore, a flat die is used for extrusion, and a polypropylene-based resin sheet is produced by cooling and solidifying with a cooling roller.

(Comparative Example 9-2)

Except for changing the ratio of homopolypropylene (hPP4) (MFR: 7.5g/10min) and atactic polypropylene (rPP6) (MFR: 7.0g/10min)) from 90:10 to 50:50, it is the same as " Comparative Example 9-1" A polypropylene resin sheet was produced in the same manner.

The evaluation results of the polypropylene-based resin sheets produced in this verification 10 are shown in the following table.

In this verification 9, similarly to verification 8, the effect of adding random polypropylene was not observed.

From the above results, it can be understood that according to the present invention, the polypropylene-based resin sheet can exhibit excellent transparency, impact resistance, and bending rigidity.

1‧‧‧Resin container

10‧‧‧Container body

10a‧‧‧Opening part

10b‧‧‧Bottom face

10f‧‧‧Flange part

10w‧‧‧Peripheral side wall

20‧‧‧Lid

X‧‧‧Contained objects

Claims (10)

A polypropylene resin sheet, which is a polypropylene resin sheet with a haze of less than 25% and is composed of a polypropylene resin composition containing a polypropylene resin, the polypropylene resin composition containing homopolymer polypropylene and random polypropylene, the content of the aforementioned random polypropylene-based comonomer components other than propylene is 0.3% by mass or more and less than 6% by mass, and the aforementioned homopolymerized polypropylene is a combination of the aforementioned homopolymerized polypropylene and the aforementioned random polypropylene. The total amount of The difference in body mass flow rate is 0.6g/10min or more and 6.0g/10min or less. In the polypropylene resin sheet described in the first aspect of the patent application, the total absorbed energy obtained by the drop weight impact test is 1.0J or more. The polypropylene resin sheet described in item 1 of the patent application has a bending rigidity of 40gf. cm ² /cm or more and 100gf． cm ² /cm or less. As for the polypropylene resin sheet described in claim 1, the polypropylene resin composition further contains a crystallization nucleating agent. The polypropylene-based resin sheet described in claim 1, wherein the melt mass flow rate of the homopolymer polypropylene is 0.1g/10min or more and 5.0g/10min or less. A method for manufacturing a polypropylene-based resin sheet by performing the following steps to produce a polypropylene-based resin sheet with a haze of 25% or less. The method for manufacturing a polypropylene-based resin sheet includes a kneading step using an extruder. Composed of polypropylene resin containing polypropylene resin The material is kneaded while heating to obtain a molten kneaded product; and an extrusion step is to extrude the aforementioned molten kneaded product from a die installed in the aforementioned extruder into a sheet shape to obtain a polypropylene-based resin sheet; in the aforementioned The polypropylene-based resin composition used in the kneading step contains homopolypropylene and random polypropylene, and the content of the copolymerized monomer components other than propylene in the random polypropylene-based resin is 0.3 mass% or more and 6 mass% or less. Or, the ratio of the aforementioned homopolymerized polypropylene to the total amount of the aforementioned homopolymerized polypropylene and the aforementioned random polypropylene is 50 mass % or more and 95 mass % or less, and the aforementioned homopolymerized polypropylene has a temperature of 230° C. and a load of 2.16 The difference between the melt mass flow rate measured in kg and the melt mass flow rate of the atactic polypropylene is 0.6 g/10 min or more and 6.0 g/10 min or less. The method for manufacturing a polypropylene resin sheet according to claim 6, wherein a flat die is used as the die in the extrusion step and the outer circumferential surface of the rotating roller is drawn from the flat die. The melt-kneaded product is extruded into a sheet shape; and, after the extrusion step, a cooling step is performed. In the cooling step, the roller is cooled and the extruded sheet is extruded by the roller. The aforementioned molten kneaded product is cooled. A resin container, which is provided with a container body having an opening at its upper part, and a lid that closes the opening, wherein at least one of the container body and the lid is made of polypropylene resin with a haze of 25% or less. The polypropylene resin sheet is composed of a polypropylene resin composition containing a polypropylene resin, and the polypropylene resin composition contains a homopolymer polypropylene and a random polypropylene. When the content of comonomer components other than propylene-based propylene is 0.3% by mass or more and 6% by mass or less, the total absorbed energy measured by the drop weight impact test when a polypropylene-based resin sheet with a thickness of 0.4mm is produced is 1.0J or more, and the bending rigidity is 40gf. cm ² /cm or more and 100gf． cm ² /cm or less. The resin container described in Item 8 of the patent application, wherein the ratio of the homopolypropylene to the total amount of the homopolypropylene and the atactic polypropylene is 50 mass% or more and 95 mass% or less, Furthermore, the difference between the melt mass flow rate of the homopolypropylene measured at a temperature of 230°C and a load of 2.16 kg and the melt mass flow rate of the random polypropylene is 0.6g/10min or more and 6.0g/10min or less. . The resin container according to claim 8 or 9, wherein the container body is composed of the polypropylene resin sheet, the container body is provided with an outwardly extending flange portion at the opening, and the lid It is composed of a top sealing material adhered to the flange portion and closing the opening portion, and the average thickness of the container body composed of the polypropylene resin sheet is 0.1 mm or more and 0.7 mm or less.

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