JP2020070376A - Propylene-based resin sheet and packaging bag for heat treatment using the same - Google Patents

Abstract

To provide a propylene-based resin single layer sheet which dispenses with a multilayer constitution requiring a complicated molding device, has small physical property change even when recycled, adaptive to heating treatment at 121°C, is furthermore excellent in transparency, flexibility and impact resistance, and is suitable for a packaging bag for heating treatment.SOLUTION: The propylene-based resin single layer sheet is provided that satisfies the following condition. A propylene-based resin composition (X) constituting the sheet contains 15 wt.% or more and less than 70 wt.% of a propylene-based resin composition (A) satisfying the following conditions (A-i) to (A-iii), 10-35 wt.% of an ethylene-α-olefin copolymer (B) satisfying the following conditions (B-i) to (B-ii), and more than 20 wt.% and 50 wt.% or less of a propylene-based resin (C) satisfying the following conditions (C-i) to (C-ii). The total amount of the propylene-based resin composition (A), the ethylene-α-olefin copolymer (B) and the propylene-based resin (C) is 100 wt.%.

Description

  The present invention relates to a propylene-based resin single-layer sheet and a heat-treatment packaging bag using the same.

  Medical liquid containers such as infusion solutions, drug solutions, and blood bags are required to have heat resistance, transparency, flexibility, and impact resistance in a well-balanced manner. As a material for such an infusion bag, for example, Japanese Patent Laid-Open No. 9-308682 (Patent Document 1) discloses at least two kinds of mixed films containing high-density polyethylene and linear low-density polyethylene in different mixing ratios. A film for a liquid container for medical use, which comprises a sealant layer formed by directly laminating layers, is disclosed. However, such a film has a problem that it cannot cope with sterilization at 121 ° C.

In addition, Japanese Patent Application Laid-Open No. 9-99036 (Patent Document 2) discloses a medical container formed of a sheet containing polypropylene as a forming layer, which is produced by a metatheron-based catalyst. The container disclosed in this document has good heat resistance, but is hard and has a problem of insufficient impact resistance.
Japanese Patent Laid-Open No. 9-75444 (Patent Document 3) discloses a medical material containing a block copolymer of a random copolymer containing propylene as a main component and a polymer containing an α-olefin other than propylene as a main component as a layer component. However, such materials have problems that heat resistance is deteriorated and that low molecular weight components bleed out.

  On the other hand, JP-A-9-324022 (Patent Document 4) discloses a polypropylene block copolymer consisting of two kinds of ethylene-propylene copolymer moieties produced in separate steps using a Ziegler-Natta type catalyst. A material such as an infusion bag is disclosed. However, the material disclosed in the document has a problem that a low molecular weight component bleeds out.

  Further, in JP 2010-229256 A (Patent Document 5), a propylene-based resin component satisfying a specific condition, an ethylene-α-olefin copolymer component satisfying a specific condition, and a propylene-based resin component satisfying a specific condition are disclosed. A propylene-based resin composition for a medical container, which comprises a resin component, and a medical container, which comprises a sheet formed from the composition, are disclosed. Although the material described in this document has good transparency, flexibility and impact resistance even if it is a single layer sheet, there is a problem that it cannot cope with sterilization at 121 ° C.

  Japanese Unexamined Patent Publication No. 2010-138211 (Patent Document 6) discloses a propylene-based resin containing a specific propylene-ethylene random copolymer component obtained by sequential polymerization, an ethylene-α-olefin copolymer having a specific density and MFR. A propylene-based resin composition containing a polymer and a propylene-based (co) polymer having a specific melting peak temperature, and a laminated sheet obtained from the composition are disclosed. Although the laminated sheet described in the document is excellent in transparency, flexibility and suitability for secondary processing, it has a problem that it cannot cope with sterilization at 121 ° C.

  As described above, the present situation is that no material for an infusion bag having heat resistance, transparency, flexibility and impact resistance in good balance has been found.

  On the other hand, as a technique corresponding to the above situation, in JP2011-068116A, JP2012-006251A and JP2016-190646A, a three-layer film of polypropylene resin is proposed (Patent Document 1). References 7-9). According to the techniques disclosed in these documents, sterilization at 121 ° C. is possible, but it is necessary that the film has a multilayer structure. However, in order to manufacture a laminated film having a multi-layered structure, a manufacturing device having a complicated structure is required, and a single-layered structure which can be more easily manufactured has been demanded. Furthermore, since the physical properties of the multi-layered film change when it is recycled in the process, there is a demand for a single-layered film that can be recycled in the process.

JP, 9-308682, A JP, 9-99036, A JP-A-9-75444 JP, 9-324022, A JP, 2010-229256, A JP, 2010-138211, A JP, 2011-068116, A JP 2012-006251 A JP, 2016-190646, A

  INDUSTRIAL APPLICABILITY The present invention does not require a multi-layered structure that requires a complicated molding apparatus, has little change in physical properties even when recycled, is compatible with heat treatment at 121 ° C., and further has transparency, flexibility and impact resistance. An object is to provide a propylene-based resin single-layer sheet suitable for a packaging bag for heat treatment, which is excellent in heat resistance.

That is, the present invention is
[1] A propylene-based resin single-layer sheet characterized by satisfying the following conditions.
The propylene-based resin composition (X) constituting the sheet is 15% by weight or more and less than 70% by weight of the propylene-based resin composition (A) satisfying the following conditions (A-i) to (A-iii), and the following conditions ( Ethylene-α-olefin copolymer (B) 10 to 35% by weight which satisfies B-i) to (B-ii), and propylene resin (C which satisfies the following conditions (C-i) to (C-ii) ) 20% by weight or more and 50% by weight or less (wherein the total amount of the propylene resin composition (A), the ethylene-α-olefin copolymer (B) and the propylene resin (C) is 100% by weight). %).
-Propylene resin composition (A):
(Ai) 30 to 70% by weight of propylene-α-olefin random copolymer (A1) having a melting peak temperature (Tm (A1)) of 125 to 145 ° C, and an ethylene content (E [A2]) of 7 to. 17% by weight of 70 to 30% by weight of a metallocene propylene-ethylene random copolymer (A2).
(A-ii) Melt flow rate (MFR (A): 230 ° C., 2.16 kg) is in the range of 0.5 to 20 g / 10 minutes.
(A-iii) In the temperature-loss tangent (tan δ) curve obtained by solid-state viscoelasticity measurement (DMA), the peak of the tan δ curve representing the glass transition observed in the range of −60 to 20 ° C. is a single value below 0 ° C. One peak is shown.
-Ethylene-α-olefin copolymer (B):
(B-i) The density is in the range of 0.860 to 0.910 g / cm ³ .
(B-ii) Melt flow rate (MFR (B): 190 ° C., 2.16 kg) is in the range of 0.1 to 20 g / 10 minutes.
・ Propylene resin (C):
(Ci) The melting peak temperature Tm (C) is in the range of 150 to 170 ° C.
(C-ii) The melt flow rate (MFR (C): 230 ° C., 2.16 kg) is in the range of 2 to 15 g / 10 minutes.
[2] The propylene-based resin single-layer sheet according to [1], wherein the content of the propylene-based resin (C) is more than 25% by weight and 50% by weight or less.
[3] The propylene-based resin single-layer sheet according to [1] or [2], wherein the ethylene-α-olefin copolymer (B) has a density in the range of 0.895 to 0.910 g / cm ³ .
[4] The propylene-based resin single-layer sheet according to any one of [1] to [3], which further comprises 1 to 30 parts by weight of a softening agent based on 100 parts by weight of the propylene-based resin composition (X). ..
[5] The propylene-based resin single-layer sheet according to any one of [1] to [4], wherein the propylene-based resin single-layer sheet is for a heat treatment packaging bag.
[6] The propylene-based resin single-layer sheet according to [5], wherein the packaging bag for heat treatment is an infusion bag.
Is provided.

  According to the present invention, there is no need for a multi-layered structure that requires a complicated molding device, physical property changes are small even when recycled, and heat treatment at 121 ° C. is possible. Furthermore, transparency, flexibility and impact resistance are achieved. It is possible to provide a propylene-based resin single-layer sheet suitable for a heat-treatment packaging bag having excellent properties.

The present invention will be described in detail below.
[1] Constituent Components of Propylene-based Resin Single-Layer Sheet The propylene-based resin single-layer sheet of the present invention comprises the following propylene-based resin composition (A) 15% by weight or more and less than 70% by weight, ethylene-α-olefin copolymer. (B) 10 wt% to 35 wt% and more than 20 wt% and not more than 50 wt% of the propylene resin (C) are formed from the propylene resin composition (X).
Propylene resin composition (A):
(Ai) 30 to 70% by weight of propylene-α-olefin random copolymer (A1) having a melting peak temperature (Tm (A1)) of 125 to 145 ° C, and an ethylene content (E [A2]) of 7 to. 17% by weight of 70 to 30% by weight of a metallocene propylene-ethylene random copolymer (A2).
(A-ii) Melt flow rate (MFR (A): 230 ° C., 2.16 kg) is in the range of 0.5 to 20 g / 10 minutes.
(A-iii) In the temperature-loss tangent (tan δ) curve obtained by solid-state viscoelasticity measurement (DMA), the peak of the tan δ curve representing the glass transition observed in the range of −60 to 20 ° C. is a single value below 0 ° C. One peak is shown.
Ethylene-α-olefin copolymer (B):
(B-i) Density is in the range of 0.860 to 0.910 g / cm ³ (B-ii) Melt flow rate (MFR (B): 190 ° C., 2.16 kg) is 1.5 to
It should be in the range of 10 g / 10 minutes.
Propylene resin (C)
(C-i) Melting peak temperature Tm (C) is in the range of 150 to 170 ° C. (C-ii) Melt flow rate (MFR (C): 230 ° C., 2.16 kg) is 2 to 15
g / 10 minutes range

(1) Propylene resin composition (A)
(1-1) Properties of Propylene-Based Resin Composition (A) Propylene-based resin composition (A) (used as one component of propylene-based resin composition (X) used in the propylene-based resin single-layer sheet of the present invention. Hereinafter, the component (A) may be used), and it is necessary that the transparency, flexibility, and impact resistance are high. In order to satisfy these requirements at a high level, the component (A) needs to satisfy the following conditions (A-i) to (A-iii).

-Basic specification of propylene-based resin composition (A) The component (A) used in the present invention is a propylene-based resin composition (A) satisfying the following conditions (A-i) to (A-iii).
(Ai) 30 to 70% by weight of propylene-α-olefin random copolymer (A1) having a melting peak temperature (Tm (A1)) of 125 to 145 ° C, and an ethylene content (E [A2]) of 7 to. It is composed of 70 to 30% by weight of 17% by weight of a metallocene-based propylene-ethylene random copolymer (A2).
(A-ii) Melt flow rate (MFR (A): 230 ° C., 2.16 kg) is 0.5 to
It is in the range of 20 g / 10 minutes.
(A-iii) In the temperature-loss tangent (tan δ) curve obtained by solid-state viscoelasticity measurement (DMA), the peak of the tan δ curve representing the glass transition observed in the range of −60 to 20 ° C. is a single value below 0 ° C. One peak is shown.

The condition (A-i) will be described in detail in the following (i) to (v).
(I) Melting peak temperature (Tm (A1)) of propylene-α-olefin random copolymer (A1)) (hereinafter sometimes referred to as “copolymer (A1)”)
The copolymer (A1) is a component that determines the crystallinity in the propylene resin composition (A). In order to improve the heat resistance of the propylene resin composition (A), it is necessary that the melting peak temperature Tm (A1) of the copolymer (A1) (hereinafter sometimes referred to as Tm (A1)) is high. On the other hand, if Tm (A1) is too high, the flexibility and transparency are impaired, and the heat-sealing temperature is increased to impair the bag-making property. Further, if Tm (A1) is too low, heat resistance may be deteriorated, thinning may be promoted during heat sealing, or inner surface fusion may occur during heat treatment at 121 ° C. or higher. Tm (A1) needs to be in the range of 125 to 145 ° C, preferably 125 to 138 ° C, and more preferably 128 to 135 ° C. The copolymer (A1) is preferably a metallocene-based propylene-α-olefin random copolymer.
The copolymer (A1) is a copolymer obtained by copolymerizing propylene and ethylene and / or an α-olefin having 4 to 20 carbon atoms, and the α-olefin is ethylene and / or Alternatively, those having 4 to 20 carbon atoms, such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, can be preferably exemplified. Of these, ethylene, 1-butene, or both are preferable.
The α-olefin content in the copolymer (A1) is preferably more than 0% by weight and less than 7% by weight, more preferably more than 0% by weight and 5% by weight or less, further preferably 0% by weight. % And 4% by weight or less, particularly preferably 0.5% by weight or more and 3% by weight or less. When the α-olefin content is within the above range, it is easy to control Tm (A1) within the above range.

  Here, the melting peak temperature Tm is a value obtained by a differential scanning calorimeter (DSC manufactured by TA Instruments). Specifically, a sample amount of 5.0 mg is taken and the temperature is 200 ° C. for 5 minutes. It is a value determined as a melting peak temperature when the crystal is held at 40 ° C. at a temperature lowering speed of 10 ° C./min and then melted at a temperature rising speed of 10 ° C./min.

(Ii) Proportion of Copolymer (A1) in Propylene Resin Composition (A) The proportion (W (A1)) of copolymer (A1) in the propylene resin composition (A) is propylene. Although it relates to imparting heat resistance to the resin composition (A), if W (A1) is too much, flexibility, impact resistance and transparency cannot be sufficiently exhibited. Therefore, the proportion of the copolymer (A1) needs to be 70% by weight or less.
On the other hand, when the proportion of the copolymer (A1) is too low, the heat resistance is lowered even if Tm (A1) is sufficient, and the thickness is reduced during heat sealing, or when heat treatment is performed at 121 ° C or higher. Since the inner surface may be fused, the proportion of the copolymer (A1) must be 30% by weight or more. The preferable range of W (A1) is 50 to 60% by weight.

(Iii) Ethylene content E [A2] in the propylene-ethylene random copolymer (A2)
The metallocene-based propylene-ethylene random copolymer (A2) (hereinafter, also referred to as "copolymer (A2)") improves flexibility, impact resistance, and transparency of the propylene-based resin composition (A). It is a necessary ingredient to make it. Generally, in a propylene-ethylene random copolymer, the crystallinity decreases and the flexibility improving effect increases as the ethylene content increases, so that the ethylene content E [A2] (hereinafter , E [A2]) is required to be 7% by weight or more. When E [A2] is 7 wt% or more, sufficient flexibility can be exhibited, and it is preferably 8 wt% or more, more preferably 10 wt% or more.
On the other hand, if E [A2] is excessively increased in order to reduce the crystallinity of the copolymer (A2), the compatibility between the copolymer (A1) and the copolymer (A2) decreases, and the copolymer (A2) decreases. ) Form a domain without being compatibilized with the copolymer (A1). In such a phase-separated structure, if the matrix and the domain have different refractive indices, the transparency is sharply reduced. Therefore, the E (A2) of the copolymer (A2) in the propylene resin composition (A) used in the present invention needs to be 17% by weight or less, preferably 14% by weight or less, and more preferably It is 12% by weight or less.
Further, the copolymer (A2) needs to be a metallocene-based propylene-ethylene random copolymer from the viewpoint of stickiness and bleed-out.

(Iv) Proportion of propylene-ethylene random copolymer (A2) in propylene resin composition (A) Ratio of propylene-ethylene random copolymer (A2) in propylene resin composition (A) ( If W (A2)) is too much, the heat resistance will decrease, so it is necessary to keep W (A2) at 70% by weight or less. On the other hand, if W (A2) is too small, the effect of improving flexibility and impact resistance cannot be obtained. Therefore, W (A2) needs to be 30% by weight or more. The preferable range of W (A2) is 50 to 40% by weight.

(V) Method for producing propylene-based resin composition (A) The propylene-based resin composition (A) used in the present invention preferably contains a metallocene-based catalyst in the first step and is a metallocene-based propylene-α-olefin random. It can be obtained by polymerizing the component (A1) which is a copolymer and successively polymerizing the component (A2) which is a metallocene propylene-ethylene random copolymer in the second step. Specifically, the method described in JP-A-2005-132979 can be used. In the case of sequential polymerization, the method described in JP-A-2005-132979 can be used as the method for measuring each requirement of (Ai).
Alternatively, the propylene-α-olefin random copolymer (A1) and the metallocene-based propylene-ethylene random copolymer (A2), which are separately produced, may be produced using a mixing device instead of the polymerization blending method. it can. For example, a method of melt kneading using a ribbon blender, a Henschel mixer (trade name), a Banbury mixer, a drum tumbler, a single-screw or twin-screw extruder, a kneader and the like can be mentioned.
When not using the polymer blending method, commercially available propylene-α-olefin random copolymer (A1) and metallocene-based propylene-ethylene random copolymer (A2) can be appropriately used. For example, as (A1), The product names "Novatech PP" and "Wintech" manufactured by Nippon Polypro Co., Ltd. may be mentioned, and (A2) may include the product name "Vistamax" manufactured by ExxonMobil, and the product name "Versify" manufactured by Dow Chemical. They can be used in appropriate combination so as to satisfy (Ai) to (A-iii).

Condition (A-ii): Melt flow rate MFR (A) of propylene resin composition (A)
The propylene resin composition (A) used in the present invention has a melt flow rate MFR (230 ° C., 2.16 kg) (hereinafter, also referred to as MFR (A)) of 0.5 to 20 g / 10 min. It is necessary to take a range.

MFR (A) is also referred to as MFR (hereinafter, MFR (A1) and MFR (A2) corresponding to the propylene-α-olefin random copolymer (A1) and the propylene-ethylene random copolymer (A2), respectively. However, in the present invention, if MFR (A) is in the range of 0.5 to 20 g / 10 min, MFR (A1) and MFR (A2) are the objects of the present invention. It is arbitrary as long as it does not impair. However, when the difference in MFR between the two is significantly different, there is a risk of defective appearance and the like, so both MFR (A1) and MFR (A2) are preferably in the range of 4 to 10 g / 10 minutes.
If the MFR (A) is too low, the resistance to rotation of the molding machine screw becomes large, so that not only the motor load and the tip pressure increase, but also the surface of the sheet becomes rough, which causes a problem that the appearance is deteriorated. Therefore, the MFR (A) is preferably 4 g / 10 minutes or more, more preferably 5 g / 10 minutes or more.
On the other hand, if the MFR (A) is too high, the molding tends to be unstable, and it becomes difficult to obtain a uniform sheet. Therefore, the MFR (A) is preferably 10 g / 10 minutes or less, preferably 8 g / 10. It is less than a minute. Here, the MFR is a value measured according to JIS K7210.

Condition (A-iii): temperature-loss tangent (tan δ) curve peak The propylene resin composition (A) used in the present invention has a temperature-loss tangent (tan δ) curve obtained by solid viscoelasticity measurement (DMA). , The peak of the tan δ curve representing the glass transition observed in the range of −60 to 20 ° C. needs to show a single peak at 0 ° C. or lower.
When the propylene-based resin composition (A) has a phase-separated structure, the glass transition temperature of the amorphous part contained in the propylene-α-olefin random copolymer (A1) and the propylene-ethylene random copolymer (A2). Since the glass transition temperatures of the amorphous parts contained in () are different from each other, there are a plurality of peaks. In this case, there arises a problem that transparency is significantly deteriorated.
Usually, the glass transition temperature of the propylene-ethylene random copolymer (A2) is observed in the range of -60 ° C to 20 ° C, and whether or not it has a phase separation structure can be obtained by solid viscoelasticity measurement in this range. The avoidance of the phase-separated structure, which is identifiable in the tan δ curve and influences the transparency of the sheet, is brought about by having a single peak below 0 ° C.

  Here, the solid viscoelasticity measurement (DMA) is specifically performed by applying a sinusoidal strain of a specific frequency to a strip-shaped sample piece and detecting the generated stress. The frequency is 1 Hz, and the measurement temperature is raised stepwise from -60 ° C until the sample melts and cannot be measured. Moreover, the magnitude of strain is recommended to be about 0.1 to 0.5%. From the obtained stress, the storage elastic modulus G ′ and the loss elastic modulus G ″ are obtained by a known method, and the loss tangent (= loss elastic modulus / storage elastic modulus) defined by the ratio thereof is plotted against temperature. , Shows a sharp peak in the temperature range of 0 ° C. or lower. Generally, the peak of the tan δ curve at 0 ° C. or lower is for observing the glass transition of the amorphous portion, and in the present invention, this peak temperature is the glass transition temperature Tg ( ° C).

(1-2) Proportion of Propylene Resin Composition (A) The proportion of the propylene resin composition (A) is such that the propylene resin composition (A), the ethylene-α-olefin copolymer (B) and propylene. It is necessary to be in the range of 15% by weight or more and less than 70% by weight, preferably 30 to 65% by weight, more preferably 35 to 60% by weight, based on 100% by weight of the total amount of the resin (C). is there.
When the content of the propylene resin composition (A) is 15% by weight or more, good flexibility and transparency are obtained, and the content of the propylene resin composition (A) is less than 70% by weight. In addition, there is no fear that the thickness will be reduced during the secondary processing such as heat sealing or the deformation during the heat treatment will be more remarkable.

(2) Ethylene-α-olefin copolymer (B)
(2-1) Characteristics of ethylene-α-olefin copolymer (B) Ethylene-α-olefin copolymer used as one component of the propylene-based resin composition (X) used in the propylene-based resin single-layer sheet of the present invention The polymer (B) (hereinafter sometimes referred to as the component (B)) is a copolymer obtained by copolymerizing ethylene and one or more α-olefins having 3 to 20 carbon atoms. As the α-olefin which is a polymer, those having 3 to 20 carbon atoms, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene and the like can be preferably exemplified. The ethylene-α-olefin copolymer (B) is a component that functions to improve the low temperature impact resistance of the propylene resin composition (X), but since it also affects flexibility and transparency, It is necessary to satisfy the conditions (B-i) to (B-ii).

  The propylene resin single layer sheet of the present invention is required to have flexibility and transparency. Regarding the transparency, when the refractive index of the ethylene-α-olefin copolymer (B) is significantly different from the mixture of the propylene resin composition (A) and the propylene resin (C), the transparency of the obtained sheet is Since it deteriorates, it is important to match the refractive index. The refractive index can be controlled by the density, and in order to obtain the transparency required in the present invention, it is important to set the density within a specific range.

Condition (B-i): Density The ethylene-α-olefin copolymer (B) used in the present invention needs to have a density in the range of 0.860 to 0.910 g / cm ³ .
If the density is too low, the refractive index difference becomes large and the transparency deteriorates. Therefore, in order to ensure the transparency required for the present invention, the density of the component (B) is 0.860 g / cm ³ or more. There is a need. The density of the component (B), preferably 0.870 g / cm ³ or more, more preferably 0.880 g / cm ³ or more, and particularly preferably 0.895 g / cm ³ or more.
On the other hand, when the density of the component (B) becomes too high, the crystallinity becomes high and the flexibility becomes insufficient. Therefore, it is necessary to be 0.910 g / cm ³ or less, preferably 0.905 g / cm ^3. Or less, more preferably 0.900 g / cm ³ or less. Here, the density is a value measured according to the D method (density density tube) according to JIS K7112: 1999.

Condition (B-ii): Melt flow rate MFR (B) of ethylene-α-olefin copolymer (B)
The propylene resin composition (X) of the present invention needs to have appropriate fluidity in order to ensure moldability. Therefore, if the melt flow rate MFR (190 ° C., 2.16 kg) of the ethylene-α-olefin copolymer (B) (hereinafter, sometimes referred to as MFR (B)) is too low, the fluidity becomes insufficient, Poor dispersion causes deterioration of transparency. Therefore, MFR (B) needs to be 0.1 g / 10 minutes or more, preferably 0.5 g / 10 minutes or more, more preferably 1.5 g / 10 minutes or more, and particularly 2 g / 10 minutes. That is all.
On the other hand, if the MFR (B) is too high, the molding is unstable and the film thickness varies. Therefore, the MFR (B) needs to be 20 g / 10 minutes or less, preferably 10 g / 10 minutes or less, and particularly preferably 9 g / 10 minutes or less.
Here, the MFR is a value measured according to JIS K7210.

(2-2) Method for producing ethylene-α-olefin copolymer (B) The ethylene-α-olefin copolymer (B) used in the present invention comprises a propylene resin composition (A) and a propylene resin (A). In order to reduce the difference in refractive index from the mixture of C), it is necessary to lower the density, and in order to suppress stickiness and bleed-out, it is desirable that the distribution of crystallinity and molecular weight is narrow. Therefore, for the production of the ethylene-α-olefin copolymer (B), it is desirable to use a metallocene catalyst capable of narrowing the crystallinity and the molecular weight distribution.
The metallocene catalyst and the polymerization method will be described below.

(I) Metallocene catalyst As the metallocene catalyst, various known catalysts used for the polymerization of ethylene-α-olefin copolymers can be used.
Specific examples thereof include metallocene catalysts described in JP-A-58-19309, JP-A-59-95292, JP-A-60-35006 and JP-A-3-163088. ..

(Ii) Polymerization method As a specific polymerization method, a slurry method in the presence of these catalysts, a gas phase fluidized bed method or a solution method, a pressure of 200 kg / cm ² (19.6 MPa) or more, and a polymerization temperature of A high pressure bulk polymerization method at 100 ° C. or higher may be used. High pressure bulk polymerization is mentioned as a preferable manufacturing method.
The ethylene-α-olefin copolymer (B) can be appropriately selected and used from those commercially available as metallocene polyethylene. Commercially available products include DuPont Dow's product names "Affinity" and "ENGAGE", Nippon Polyethylene's product names "Kernel" and "HARMOREX", Exxon Mobil The product name “EXACT” and the like can be mentioned. In these uses, a grade that satisfies the requirements of the present invention, density and MFR, may be appropriately selected.
In addition, the component (B) may be composed of a plurality of ethylene-α-olefin copolymers, and in that case, the mixture of a plurality of ethylene-α-olefin copolymers may satisfy the requirements of the component (B). For example, grades having different densities and MFRs may be combined so that the mixture satisfies the requirement of the component (B).

(2-3) Ratio of ethylene-α-olefin copolymer (B) The ratio of the ethylene-α-olefin copolymer (B) in the propylene resin composition (X) is such that the propylene resin composition (A ), The ethylene-α-olefin copolymer (B) and the propylene-based resin (C), the total amount of 100% by weight is required to be in the range of 10 to 35% by weight.
When the content of the ethylene-α-olefin copolymer (B) is too small, the low temperature impact resistance cannot be imparted sufficiently. On the other hand, when the content of the ethylene-α-olefin copolymer (B) is too large, the thickness of the sheet becomes uneven, and a sheet having a good appearance cannot be obtained.
Therefore, the proportion of the ethylene-α-olefin copolymer (B) in the composition must be in the range of 10 to 35% by weight, and in the case of 10% by weight or more, the flexibility and low temperature impact resistance are high. Sufficient property can be imparted, and when it is 35% by weight or less, the moldability is good. The preferable content of the ethylene-α-olefin copolymer (B) is 100% by weight of the total amount of the propylene resin composition (A), the ethylene-α-olefin copolymer (B) and the propylene resin (C). With respect to 15 to 35% by weight.

(3) Propylene resin (C)
(3-1) Properties of Propylene-based Resin (C) Propylene-based resin (C) preferably used as one component of the propylene-based resin composition (X) of the present invention (hereinafter sometimes referred to as component (C)). Is used as a moldability, a thickness variation suppression, a thinning suppression, and a heat distortion resistant component.
The propylene-based resin composition (A) used as the main component of the propylene-based resin composition (X) is extremely effective for imparting high flexibility and transparency to the laminated sheet, but among them, propylene-α- Since the olefin random copolymer (A1) is a resin having a relatively low melting point, it has a small amount of high crystalline components, is thinned during heat sealing, is likely to be deformed during heat treatment at 121 ° C. or higher, and is easily fused on the inner surface. Have problems such as. In particular, the one obtained by using the metallocene catalyst has a sharp crystallinity distribution, which is especially remarkable.

Therefore, if the crystallinity distribution of the propylene-based resin composition (A) is expanded to increase the relatively high crystal component, the low crystal component is inevitably increased, and as a result, it is caused by bleeding out to the sheet surface. Since it causes problems such as stickiness and poor appearance, it is not suitable for applications requiring transparency.
Therefore, by adding a specific amount of the propylene-based resin (C) to the propylene-based resin composition (A) having a small amount of the high-crystalline component, the high-crystalline component and the high-molecular component can be increased without increasing the low-crystalline component and the low-molecular weight component. The molecular weight component can be increased, and as a result, thickness variation during heat sealing, thinning during heat sealing, deformation during heat treatment at 121 ° C or more, and inner surface fusion can be achieved without causing appearance defects such as bleeding out. It becomes possible to control.

(C-i) Melting peak temperature Tm (C)
The component (C) is a propylene-based resin having a melting peak temperature Tm (C) in the range of 150 to 170 ° C, and more preferably 155 to 170 ° C.
When Tm (C) is 150 ° C. or higher, the high crystalline component is not deficient, sufficient fluidity can be reduced, and the effect of suppressing thinning and shape retention during heat treatment at 121 ° C. or higher can be obtained. Further, when Tm (C) is 170 ° C. or less, industrial production is possible. A more preferable Tm (C) is 155 to 166 ° C.

(C-ii) Melt flow rate MFR (C)
The component (C) in the present invention needs to have appropriate fluidity in order to secure moldability, and the melt flow rate MFR (230 ° C., 2.16 kg load) which is a measure of fluidity (hereinafter, MFR (C)) is required to be in the range of 2 to 15 g / 10 minutes, and the preferable upper limit is 12 g / 10 minutes, more preferably 10 g / 10 minutes. A particularly preferable range of MFR is 2.5 to 10 g / 10 minutes.
When the MFR (C) is 2 g / 10 minutes or more, the dispersion is good and the appearance defects called gel and fish eyes are unlikely to occur. Further, when the MFR (C) is 15 g / 10 minutes or less, the molding is stable and the film thickness variation is less likely to occur.
Here, the MFR is a value measured according to JIS K7210.

(3-2) Method for producing component (C) The propylene-based resin (C) may be produced by any method as long as the above-mentioned various properties are satisfied. As long as the above conditions are satisfied, a propylene homopolymer, propylene-α. It may be an olefin random copolymer, a propylene-α-olefin block copolymer or a mixture thereof, but is preferably a propylene homopolymer.
When the component (C) is a propylene-α-olefin random copolymer or a propylene-α-olefin block copolymer, propylene is preferably copolymerized with ethylene and / or an α-olefin having 4 to 20 carbon atoms. A copolymer obtained by polymerization, wherein the α-olefin has ethylene and / or one having 4 to 20 carbon atoms, for example, 1-butene, 1-pentene, 1-hexene, 1-octene, 1- Preferred examples include heptene. Of these, ethylene, 1-butene, or both are preferable.
When the component (C) is a propylene-α-olefin random copolymer, the α-olefin content is preferably more than 0% by weight and 3% by weight or less, more preferably more than 0% by weight and 2% by weight. % Or less, more preferably more than 0% by weight and 1% by weight or less. When the α-olefin content is within the above range, it is easy to control Tm (C) within the above range.
When the component (C) is a propylene-α-olefin block copolymer, it is a multi-stage stack consisting of a propylene (co) polymer component (C-1) and a propylene-α-olefin copolymer component (C-2). It is a propylene-α-olefin block copolymer which is a combination. The propylene (co) polymer component (C-1) is preferably a propylene homopolymer component or a propylene-α-olefin random copolymer component, more preferably a propylene homopolymer component. When the propylene (co) polymer component (C-1) is a propylene-α-olefin random copolymer component, the α-olefin content is preferably more than 0% by weight and 3% by weight or less, It is preferably 0.1 to 3% by weight, more preferably 1.0 to 2.8% by weight, and particularly preferably 1.5 to 2.6% by weight. When the α-olefin content is within the above range, it is easy to control Tm (C) within the above range. The α-olefin content of the propylene-α-olefin copolymer component (C-2) is preferably 5 to 30% by weight, more preferably 7 to 20% by weight, further preferably 8 to 18% by weight. Is. When the α-olefin content is within the above range, impact resistance and transparency are improved, which is preferable. When the component (C) is a propylene-α-olefin block copolymer, the total of the propylene (co) polymer component (C-1) and the propylene-α-olefin copolymer component (C-2) is 100% by weight. The proportion of the propylene-α-olefin copolymer component (C-2) is preferably 5 to 50% by weight, more preferably 10 to 45% by weight.

The component (C) can also be appropriately selected and used from commercially available products. Examples of commercially available products include trade names "Novatech PP" and "Newcon" manufactured by Japan Polypro Co., Ltd. and trade names "Zelas" manufactured by Mitsubishi Chemical Corporation. In these uses, a grade that satisfies the melting peak temperature and MFR, which are the conditions in the present invention, may be appropriately selected.
Further, the component (C) may be composed of a plurality of propylene-based resins, in which case a mixture of a plurality of propylene-based resins may satisfy the requirements of the component (C), for example, grades having different melting points or MFRs. As long as the mixture satisfies the requirement of the component (C).

(3-3) Ratio of component (C) The ratio of the component (C) to the propylene resin composition (X) needs to be in the range of more than 20% by weight and 50% by weight or less.
Since the melting peak temperature of the component (C) is higher than that of the component (A), keeping the crystalline state even at the temperature at which the component (A) melts prevents the component (A) from flowing and suppresses thinning. , And exhibits the effect of preventing deformation and suppressing inner surface fusion during heat treatment at 121 ° C. or higher.
At this time, if the amount of the component (C) is too small, the high crystalline component becomes insufficient, and it is possible to obtain a sufficient effect of suppressing the thinning, a deformation prevention during the heat treatment at 121 ° C. or higher, and an inner surface fusion prevention effect. Therefore, it is necessary to exceed 20% by weight, preferably above 25% by weight. On the other hand, when the amount of the component (C) is too large, the physical properties such as flexibility and transparency are remarkably deteriorated and the quality required for the resin composition of the present invention cannot be satisfied. % Or less, preferably 40% by weight or less, more preferably 35% by weight or less.

(4) Softener The propylene-based resin composition (X) used in the propylene-based resin single-layer sheet of the present invention contains the component (A) for the purpose of adjusting the flexibility of the propylene-based resin single-layer sheet to a desired value. It is preferable to further mix 1 to 30 parts by weight of a softening agent (hereinafter, also referred to as a softening agent (D) or a component (D)) with respect to a total of 100 parts by weight of the components (B) and (C). ..
The softening agent preferably used in the present invention is preferably a polystyrene-based thermoplastic elastomer having a polystyrene hard segment and a polydiene soft segment in the molecule, for example, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, Styrene-ethylene / butylene-styrene block copolymer, styrene-ethylene / propylene-styrene block copolymer, hydrogenated polymer of random styrene / butadiene rubber, those disclosed in JP2017-57419A, WO2017 / 043532 pamphlet The thing etc. which have been disclosed can be mentioned.
The component (D) can also be appropriately selected and used from commercially available products. Examples of commercially available products include hydrogenated styrene-butadiene block copolymers under the trade name of "Clayton G" from Clayton Polymer Japan Co., Ltd., and trade name of "Tough Tech" from Asahi Kasei Chemicals Corporation. -A trade name of "Septon" from Kuraray Co., Ltd. as a hydrogenated product of isoprene block copolymer, and a trade name of "High Blur" from Kuraray Co., Ltd. as a hydrogenated product of styrene-vinylated polyisoprene block copolymer. Is sold as a hydrogenated product of a styrene-butadiene random copolymer under the trade name of "Dinalon" by JSR Corporation, and may be appropriately selected and used from these product groups. Further, they may be blended alone or in combination of two or more species depending on the desired properties.

(4-1) Properties of Softening Agent (D) The softening agent (D) can be used without particular limitation as long as it can adjust the flexibility of the propylene resin single layer sheet to a desired value. In the case of those having an aromatic vinyl structural unit such as a butadiene block copolymer, it is preferable that the content of the aromatic vinyl unit is 7 to 25% by weight since flexibility is easily expressed, and more preferably 10 to 20% by weight. Is.
Further, considering the dispersibility of the mixture of the component (A), the component (B) and the component (C), the viscosity of the softening agent (D) is large as compared with the component (A) or the component (B) or the component (C). It is preferable that the MFR (230 ° C. 2.16 kg load) is 0.5 to 20, more preferably 2 to 15, MFR (230 ° C. 5 kg load) is 1 to 40, and more preferably 2 to 30. Those are preferable.

(5) Additional component (additive)
The propylene-based resin composition (X) used in the propylene-based single-layer sheet of the present invention may contain any additive such as bleed-out within a range not significantly impairing the effects of the present invention. Such optional components include antioxidants, crystal nucleating agents, clarifiers, lubricants, antiblocking agents, antistatic agents, antifogging agents, neutralizing agents, metal inactive agents used in ordinary polyolefin resin materials. Examples thereof include agents, colorants, dispersants, peroxides, fillers and optical brighteners. Various additives will be described in detail below. Further, an elastomer can be blended as a component that imparts flexibility within a range that does not significantly impair the effects of the present invention.

(1) Antioxidant As the antioxidant, a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant and the like can be used.
Specific examples of the phenolic antioxidant include tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate and 1,1,3-tris (2-methyl-4-hydroxy-5). -T-butylphenyl) butane, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis {3- (3,5-di-t-butyl-4) -Hydroxyphenyl) propionate}, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- {3 -(3-t-Butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] unde Emissions, such as 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid.

Specific examples of the phosphorus-based antioxidant include tris (mixed, mono- and dinonylphenyl phosphite), tris (2,4-di-t-butylphenyl) phosphite, 4,4′-butylidene bis (3-). Methyl-6-t-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-di-tridecylphosphite-5-t-butylphenyl) butane, bis (2,2 4-di-t-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-t) -Butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-pho Examples include sfight.
Specific examples of the sulfur-based antioxidant include di-stearyl-thio-di-propionate, di-myristyl-thio-di-propionate, pentaerythritol-tetrakis- (3-lauryl-thio-propionate) and the like. it can.
These antioxidants can be used singly or in combination of two or more as long as the effects of the present purpose are not impaired.

  The blending amount of the antioxidant is 0.01 to 1.0 part by weight, preferably 0.02 to 0.5 part by weight, and more preferably 0.05 to 0.1 part by weight with respect to 100 parts by weight of each resin. It is a department. When the blending amount is equal to or more than the above lower limit value, the effect of thermal stability is obtained, deterioration is less likely to occur during the production of the resin, and fish eyes due to burns can be suppressed. Further, when it is at most the above upper limit value, it is possible to prevent the substance itself from becoming a foreign substance and causing a fish eye, which is preferable.

(2) Antiblocking Agent The antiblocking agent has an average particle size of 1 to 7 μm, preferably 1 to 5 μm, and more preferably 1 to 4 μm. When the average particle diameter is 1 μm or more, the slipperiness and opening property of the obtained sheet are good, which is preferable. Further, when it is 7 μm or less, transparency and scratch resistance are good, which is preferable. Here, the average particle diameter is a value measured by a Coulter counter.

Specific examples of the antiblocking agent include, for example, synthetic or natural silica (silicon dioxide), magnesium silicate, aluminosilicate, talc, zeolite, aluminum borate, calcium carbonate, calcium sulfate, barium sulfate, calcium phosphate. Etc. are used.
As the organic type, polymethylmethacrylate, poly (methylsilyltosesquioxane) (silicone), polyamide, polytetrafluoroethylene, epoxy resin, polyester resin, benzoguanamine / formaldehyde (urea resin), phenol resin, etc. may be used. it can.
In particular, synthetic silica and polymethylmethacrylate are preferable from the viewpoint of balance among dispersibility, transparency, blocking resistance, and scratch resistance.
Further, the anti-blocking agent may be surface-treated, and as the surface-treating agent, surfactants, metal soaps, organic acids such as acrylic acid, oxalic acid, citric acid, tartaric acid, higher alcohols, esters, Condensed phosphates such as silicone, fluorine resin, silane coupling agent, sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate, and sodium trimetaphosphate can be used, especially those treated with citric acid among organic acid treatments. Is preferred. The treatment method is not particularly limited, and a known method such as surface spraying or dipping can be adopted.
The anti-blocking agent may have any shape, and may have any shape such as spherical shape, angular shape, columnar shape, needle shape, plate shape, and irregular shape.
These anti-blocking agents can be used alone or in combination of two or more as long as the effect of the present purpose is not impaired.

  When the anti-blocking agent is blended, the blending amount is 0.01 to 1.0 part by weight, preferably 0.05 to 0.7 part by weight, and more preferably 0.1 to 0. 5 parts by weight. When the blending amount is at least the above lower limit value, the antiblocking property, the slip property and the opening property of the sheet are good. When it is at most the above upper limit value, the transparency of the sheet will not be impaired, and it will be possible to prevent itself from becoming a foreign substance and causing fish eyes, which is preferable.

(3) Slip Agent Examples of slip agents include monoamides, substituted amides, and bisamides, and these can be used alone or in combination of two or more.
Specific examples of the monoamides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide as the saturated fatty acid monoamide.
Examples of unsaturated fatty acid monoamides include oleic acid amide, erucic acid amide, and ricinoleic acid amide.
Specific examples of the substituted amides include N-stearyl stearic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, N-oleyl palmitic acid amide. Etc.
Specific examples of the bisamides, as saturated fatty acid bisamide, methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebisisostearic acid amide, ethylenebishydroxystearic acid amide, Ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylenebishydroxystearic acid amide, N, N'-distearyl adipic acid amide, N, N'-distearyl Examples include amide sepacic acid.
Examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N'-dioleyl adipate amide, and N, N'-dioleyl sepacic acid amide.
Examples of the aromatic bisamide include m-xylylenebisstearic acid amide and N, N′-distearylisophthalic acid amide.
Of these, oleic acid amide, erucic acid amide, and behenic acid amide are particularly preferably used among the fatty acid amides.

  The blending amount of the slip agent is 0.01 to 1.0 part by weight, preferably 0.05 to 0.7 part by weight, and more preferably 0.1 to 0 part by weight with respect to 100 parts by weight of the resin. 0.4 parts by weight. When it is at least the above lower limit, the openability and the slipperiness are good. When it is at most the above upper limit value, the slipping-out of the slip agent will not be excessive, and bleeding on the surface of the sheet and deterioration of transparency can be prevented.

(4) Nucleating agent Specific examples of the nucleating agent include sodium 2,2-methylene-bis (4,6-di-t-butylphenyl) phosphate, talc, and 1,3,2,4-di (p-methyl). Sorbitol-based compounds such as benzylidene) sorbitol, hydroxy-di (t-butylbenzoic acid) aluminum, hydroxy-bis [2,2-methylene-bis (4,6-di-t-butylphenyl) phosphoric acid] aluminum, and carbon number 8 to 20 lithium monocarboxylic acid lithium salt mixture (manufactured by ADEKA, trade name NA21) and the like can be mentioned.
The amount of the nucleating agent to be blended is 0.0005 to 0.5 part by weight, preferably 0.001 to 0.1 part by weight, and more preferably 0. It is 005 to 0.05 parts by weight. When it is at least the above lower limit value, the effect as a nucleating agent can be obtained, and when it is at most the above upper limit value, it is possible to prevent the substance itself from becoming a foreign substance and causing fish eyes, which is preferable.

Further, as a nucleating agent other than the above, a high density polyethylene resin can be cited. The high-density polyethylene resin has a density of 0.94 to 0.98 g / cm ³ , and preferably 0.95 to 0.97 g / cm ³ . When the density is within this range, the effect of improving transparency can be obtained. The 190 ° C. melt flow rate (MFR) of the high-density polyethylene resin is 5 g / 10 min or more, preferably 7-500 g / 10 min, and more preferably 10-100 g / 10 min. When the MFR is 5 g / 10 minutes or more, the dispersed diameter of the high-density polyethylene resin becomes sufficiently small, and it is possible to prevent the itself from becoming a foreign substance and causing fish eyes, which is preferable. Further, in order for the high-density polyethylene resin to be finely dispersed, it is preferable that the MFR of the high-density polyethylene resin be larger than the MFR of the propylene resin composition of the present invention.

  In the production of the high-density polyethylene resin used as a nucleating agent, the polymerization method and catalyst are not particularly limited as long as a polymer having the desired physical properties can be produced. The catalysts include Ziegler type catalysts (ie, those based on a combination of supported or unsupported halogen-containing titanium compounds and organoaluminum compounds), Kaminsky type catalysts (ie, supported or unsupported metallocene compounds and organoaluminum compounds, particularly alumoxane). Based on the combination). The shape of the high-density polyethylene-based resin is not limited, and may be in the form of pellets or powder.

  When used as a nucleating agent, the content of high-density polyethylene is 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, and more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the resin. It is a department. When the amount is at least the above lower limit, the effect as a nucleating agent is obtained, and when the amount is less than the above upper limit, it is possible to prevent the substance itself from becoming a foreign substance and causing fish eyes, which is preferable.

(5) Neutralizing agent Specific examples of the neutralizing agent include calcium stearate, zinc stearate, hydrotalcite, and Mizucarak (manufactured by Mizusawa Chemical Industry Co., Ltd.).
The blending amount of the neutralizing agent is 0.01 to 1.0 part by weight, preferably 0.02 to 0.5 part by weight, and more preferably 0.05 to 0.1 part by weight with respect to 100 parts by weight of the resin. Parts by weight. When the amount is not less than the above lower limit, the effect as a neutralizing agent is obtained, and the deteriorated resin inside the extruder is hardly scratched out to cause fish eyes. Further, when it is at most the above upper limit value, it is possible to prevent the substance itself from becoming a foreign substance and causing fish eyes, which is preferable.

(6) Light Stabilizer As the light stabilizer, a hindered amine-based stabilizer is preferably used, and a structure in which all hydrogens bonded to the carbons at the 2nd and 6th positions of the conventionally known piperidine are replaced with methyl groups. The compound having is used without particular limitation, and specifically, the following compounds are used.
As a specific example, a polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, tetrakis (1,2,2,6,6) -Pentamethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, N, N-bis (3-aminopropyl) ) Ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4- Diil} {(2,2 , 6-Tetramethyl-4-piperidyl) imino} hexamethylene {2,2,6,6-tetramethyl-4-piperidyl} imino], poly [(6-morpholino-s-triazine-2,4-diyl) Examples include [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}].
These hindered amine-based stabilizers can be used alone or in combination of two or more within a range that does not impair the intended effect.

When the hindered amine-based stabilizer is blended, the blending amount is 0.005 to 2 parts by weight, preferably 0.01 to 1 part by weight, and more preferably 0.05 to 0.5 part by weight, relative to 100 parts by weight of the resin. Is desirable.
When the content of the hindered amine-based stabilizer is 0.005 parts by weight or more, the effects of improving stability such as heat resistance and aging resistance are obtained, and when it is 2 parts by weight or less, it becomes a foreign substance. This is preferable because it can prevent the occurrence of fish eyes.

(7) Antistatic Agent The antistatic agent can be used without particular limitation as long as it is a known one which has been conventionally used as an antistatic agent or an antistatic agent, and examples thereof include anionic surfactants and cations. Examples of the surfactant include a nonionic surfactant, a nonionic surfactant, and an amphoteric surfactant.

  Examples of the anionic surfactants include carboxylic acid salts such as fatty acid or rosin acid soap, N-acyl carboxylic acid salts, ether carboxylic acid salts, fatty acid amine salts; sulfosuccinic acid salts, ester sulfonic acid salts, N-acyl sulfonic acids. Sulfonates such as salts; sulfated oils, sulfate esters, alkyl sulfates, alkyl polyoxyethylene sulfates, sulfate ester salts such as sulfate ether salts, sulfate amide salts; alkyl phosphates, alkyl polyoxyethylene phosphates Examples thereof include salts, phosphoric acid ether salts, phosphoric acid ester salts such as phosphoric acid amide salts, and the like.

  Examples of the cationic surfactant include amine salts such as alkylamine salts; alkyltrimethylammonium chloride, alkylbenzyldimethylammonium chloride, alkyldihydroxyethylmethylammonium chloride, dialkyldimethylammonium chloride, tetraalkylammonium salt, N, N-diamine. Quaternary ammonium salts such as (polyoxyethylene) dialkylammonium salt and N-alkylalkanamidoammonium salt; 1-hydroxyethyl-2-alkyl-2-imidazoline, 1-hydroxyethyl-1-alkyl-2-alkyl 2-alkylimidazoline derivatives such as imidazoline; imidazolinium salts, pyridinium salts, isoquinolinium salts and the like.

  Examples of the nonionic surfactant include ether types such as alkyl polyoxyethylene ethers and p-alkylphenyl polyoxyethylene ethers; fatty acid sorbitan polyoxyethylene ethers, fatty acid sorbitol polyoxyethylene ethers, fatty acid glycerin polyoxyethylene ethers and the like. Ester form of fatty acid polyoxyethylene ester, monoglyceride, diglyceride, sorbitan ester, sucrose ester, dihydric alcohol ester, borate ester, etc .; dialcohol alkylamine, dialcohol alkylamine ester, fatty acid alkanolamide, N, N-di (polyoxyethylene) alkanamide, alkanolamine ester, N, N-di (polyoxyethylene) alkaneamine, amine De, a nitrogen-formed and fabricated and alkyl polyethylene imine.

  Examples of the amphoteric surfactant include amino acid forms such as monoaminocarboxylic acid and polyaminocarboxylic acid; N-alkyl-β-alanine such as N-alkylaminopropionate and N, N-di (carboxyethyl) alkylamine salt. Form; N-alkylbetaine, N-alkylamidobetaine, N-alkylsulfobetaine, N, N-di (polyoxyethylene) alkylbetaine, imidazolinium betaine and other betaine forms; 1-carboxymethyl-1-hydroxy- Examples thereof include alkylimidazoline derivatives such as 1-hydroxyethyl-2-alkyl-2-imidazoline and 1-sulfoethyl-2-alkyl-2-imidazoline.

  Among these, nonionic surfactants and amphoteric surfactants are preferable, and among them, ester-type or nitrogen-containing type non-ionic types such as monoglyceride, diglyceride, borate ester, dialcohol alkylamine, dialcohol alkylamine ester, and amide. Ionic surfactants; betaine-type amphoteric surfactants are preferred.

  As the antistatic agent, a commercially available product can be used. For example, electrostripper TS5 (trademark, glycerin monostearate, manufactured by Kao Corporation), electrostripper TS6 (trademark, stearyl, manufactured by Kao Corporation). Diethanolamine), Electrostriper EA (Kao Corporation, trademark, lauryldiethanolamine), Electrostripper EA-7 (Kao Corporation, trademark, polyoxyethylenelaurylamine capryl ester), Denon 331P (Maruhishi Oilification ( Co., Ltd., trademark, stearyldiethanolamine monostearate), Denone 310 (trademark, manufactured by Maruhishi Yuka Co., Ltd., trademark, alkyldiethanolamine fatty acid monoester), Register PE-139 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trademark) , Stearic acid mono & diglyceride Ester), Chemistat 4700 (Sanyo Chemical Industries Co., Ltd., trademark, alkyl dimethyl betaine), rheostat S (Lion Co., Ltd., trademark, alkyl diethanolamide), and the like.

  When the antistatic agent is blended, the blending amount is 0.01 to 2 parts by weight, preferably 0.05 to 1 part by weight, and more preferably 0.1 to 0.8 part by weight, relative to 100 parts by weight of the resin. Most preferably, it is 0.2 to 0.5 part by weight. These antistatic agents can be used alone or in combination of two or more within a range that does not impair the intended effect. When the compounding amount of the antistatic agent is 0.01 parts by weight or more, surface specific resistance can be reduced to prevent damage due to electrification, and when the compounding amount is 2 parts by weight or less, powder blowing on the sheet surface due to bleed hardly occurs. Become.

[II] Production of Propylene-based Resin Single-Layer Sheet Constituting Resin Composition The propylene-based resin composition (X) constituting the propylene-based resin single-layer sheet of the present invention is the above-mentioned propylene-based resin composition (A), ethylene- Henschel mixer (trade name), V blender, ribbon blender, tumbler blender, etc. containing α-olefin copolymer (B), propylene resin (C), and optionally softening agent (D) and other additives as necessary. It is obtained by mixing with. After mixing, it can also be obtained by a method of kneading with a kneader such as a single-screw extruder, a multi-screw extruder, a kneader or a Banbury mixer.
Further, the respective components of the above-mentioned resin compositions may be mixed at the same time, may be mixed in a plurality of times, or may be partly used as a master batch and mixed.

[III] Propylene-based resin single-layer sheet The propylene-based resin single-layer sheet of the present invention can be produced by a known method using the propylene-based resin composition (X). For example, it is manufactured by a known technique such as extrusion molding using a T-die or a circular die. A water-cooled inflation method using a circular die is preferred.
Incidentally, the single-layer sheet here means that it is substantially a single layer, and when a multi-layer sheet molding machine is used, if the same resin composition is used for all layers, Considered a layer. Specifically, when a molding machine for three layers is used and the same resin composition is used for all layers, a sheet of one kind of three layers is obtained, but in this case, it is considered as a single layer.
In addition, since the propylene-based resin single-layer sheet of the present invention has a single-layer structure, a part of the propylene-based resin composition (X), which is a raw material for molding the propylene-based resin sheet, is used as a scrap material of the sheet once molded. It is possible to suppress the waste generated during the sheet production as much as possible.
The propylene-based resin single-layer sheet of the present invention is excellent in flexibility, transparency, impact resistance, heat resistance, and cleanliness, can suppress thickness unevenness, and can suppress thinning in secondary processing such as heat sealing. In addition, while it has excellent performance that it can retain its shape even when it is heat-treated at a temperature of 121 ° C or higher, it does not cause physical property change during recycling, which was difficult to achieve with a multilayer sheet. It has a characteristic that generation can be suppressed as much as possible. It is suitable for a packaging bag for heat treatment that requires a heat treatment step such as sterilization or sterilization, particularly an infusion bag that requires a heat treatment at 121 ° C. or higher.
The heat treatment packaging bag such as an infusion bag includes a so-called single bag including only one chamber and a so-called multi-compartment bag divided into a plurality of compartments, and any of them can be used.

  In the following, in order to describe the present invention more specifically and clearly, the present invention will be described in comparison with Examples and Comparative Examples, and the rationality and significance of the constituent features of the present invention will be demonstrated. The invention is not limited to these examples. The physical property measuring methods, characteristic evaluation methods, and resin materials used in Examples and Comparative Examples are as follows.

1. Measurement method of resin physical properties (1) MFR (unit: g / 10 minutes): Propylene resin composition (A) and propylene resin (C) are in accordance with JIS K7210 A method condition M, test temperature: 230 ° C., nominal Load: 2.16 kg, die shape: diameter 2.095 mm, length 8.00 mm.
The ethylene-α-olefin copolymer (B) was measured according to JIS K7210 A method, condition D, test temperature: 190 ° C., nominal load: 2.16 kg, die shape: diameter 2.095 mm, length 8.00 mm.
(2) Density (unit: g / cm ³ ): Measured by the density gradient tube method according to JIS K7112 D method.
(3) Melting peak temperature (Tm, unit: ° C): Using a product name Q2000 type differential scanning calorimeter (DSC) manufactured by TA Instruments, the temperature was once raised to 200 ° C and kept for 5 minutes. After erasing the thermal history, the temperature was lowered to 40 ° C at a temperature decrease rate of 10 ° C / min, held for 1 minute, and again measured at the temperature increase rate of 10 ° C / min. The temperature (melting point) (Tm) was used. When a plurality of endothermic peaks appeared, the largest endothermic peak was taken as the melting peak temperature (melting point) (Tm). The measurement sample was 5 mg.

(4) Solid viscoelasticity measurement The sample used for the measurement was a sheet cut into a strip of 10 mm width × 18 mm length × 2 mm thickness from a 2 mm thick sheet injection-molded under the following conditions. The device used was ARES manufactured by Rheometric Scientific. The frequency is 1 Hz. The measurement temperature rises at a rate of 3 ° C / 30 seconds from -60 ° C to 20 ° C, and gradually rises at a rate of 3 ° C / 40 seconds above 20 ° C, and the sample melts and measurement becomes impossible. The measurement was performed until. The strain was performed in the range of 0.1 to 0.5%. Then, in the temperature-loss tangent (tan δ) curve obtained by the measurement, it was confirmed whether the tan δ curve has a single peak at 0 ° C. or less or is separated.
[Creation of test pieces]
Standard number: JIS-7152 (ISO294-1)
Molding machine: EC-20 injection molding machine manufactured by Toshiba Kikai Molding machine Set temperature: 80,80,160,200,200,200 ° C from under the hopper
Mold temperature: 40 ℃
Injection speed: 200 mm / sec (speed in mold cavity)
Holding pressure: 20MPa
Holding time: 40 seconds Mold shape: Flat plate (thickness 2 mm, width 40 mm, length 80 mm)

2. Evaluation method of propylene resin sheet (1) Heat resistance (appearance)
A cylindrical propylene resin multilayer sheet was cut into a size of 210 mm in the flow direction, and one of the cut pieces was heat-sealed (heat-sealing condition: width of seal bar 10 mm, pressure 0.34 MPa, time 5 seconds, temperature 160 C., heat sealer manufactured by Tester Sangyo Co., Ltd.) to form a bag. Then, 250 ml of pure water was filled therein, and the other side was heat-sealed by using an impulse sealer and sealed. The heat seals were sealed so that the distance between them was 200 mm.

The sample bag thus obtained was placed in a small cooking sterilization tester (Yamakura SII Co., Ltd., YRF-40.50EZ type) and then the ambient temperature was raised to 121 ° C. Hold for 20 minutes. Then, it cooled to about 50 degreeC and took out this sample bag from a test machine. Hereinafter, this heat-treated sample bag may be referred to as a “heat-treated sample bag”, and the water removed from the sample bag may be referred to as a “heat-treated sheet”.
The heat resistance of the heat-treated sheet was evaluated according to the following criteria.
Δ: Unusable due to deformation, wrinkles and inner surface fusion.
○-: A level that can be used although it is slightly deformed.
◯: Deformation, wrinkles, and fusion on the inner surface did not occur, and the state was good.

(2) Transparency (internal haze):
After the heat treatment, both sides of the sheet were brought into close contact with a slide glass with liquid paraffin, and measured with a haze meter in accordance with JIS-K7136-2000. The smaller the obtained value is, the better the transparency is. When this value is 15% or less, it is easy to confirm the contents and the display effect is excellent, and 12% or less is preferable and 10% is preferable. The following are particularly preferred.

(3) Flexibility (tensile modulus):
According to JIS K-7127-1989, the tensile modulus in the machine direction (MD) of the sheet after heat treatment was measured under the following conditions. The smaller the obtained value is, the more excellent the flexibility is, and when the value is 400 MPa or less, it is excellent in obtaining a high-quality feeling with a good tactile feel, and 380 MPa or less is preferable, and 360 MPa or less is particularly preferable. preferable.
Sample length: 110mm
Sample width: 10 mm
Distance between chucks: 50 mm
Crosshead speed: 0.5mm / min
(4) Drop bag impact test: (Bag resistance)
After the heat-treated sample bag prepared by the above method was conditioned for 1 day or more in an atmosphere of 5 ° C., the obtained heat-treated sample bag was dropped from a height of 2 m on a metal plate 10 times in succession. The maximum number of drops without breaking the bag was evaluated. The average value of the maximum number of drops in which N = 5 was evaluated and the bag was not broken was used as an index of bag breaking resistance. It is considered to be at a practical level unless the bag is broken five times or more on average.

3. Resin used (1) Propylene resin composition (A)
The propylene-based resin composition (A-1) obtained by sequential polymerization according to the following Production Example (A-1) was used.

[Production Example (A-1): Production of PP (A-1)]
(I) Preparation of prepolymerization catalyst (chemical treatment of silicate)
A glass separable flask equipped with a 10-liter stirring blade was slowly added with 3.75 liters of distilled water, followed by 2.5 kg of concentrated sulfuric acid (96%). At 50 ° C, 1 kg of montmorillonite (manufactured by Mizusawa Chemical Co., Ltd., trade name Benclay SL; average particle size = 25 µm, particle size distribution = 10 to 60 µm) was further dispersed, and the temperature was raised to 90 ° C for 6.5 hours. The temperature was maintained. After cooling to 50 ° C., this slurry was filtered under reduced pressure to collect a cake. Distilled water (7 liters) was added to this cake to form a reslurry, which was then filtered. This washing operation was carried out until the pH of the washing liquid (filtrate) exceeded 3.5. The collected cake was dried overnight at 110 ° C. under a nitrogen atmosphere. The weight after drying was 707 g.

(Drying of silicate)
The previously chemically treated silicate was dried by a kiln dryer. The specifications and drying conditions are as follows.
Rotating cylinder: cylindrical, inner diameter 50 mm, heating zone 550 mm (electric furnace)
Rotation speed with scraping blade: 2 rpm Tilt angle: 20/520
Silicate supply rate: 2.5 g / min Gas flow rate: Nitrogen 96 liters / hour Countercurrent drying temperature: 200 ° C (powder temperature)

(Preparation of catalyst)
An autoclave with an internal volume of 16 liters equipped with a stirring and temperature control device was thoroughly replaced with nitrogen. 200 g of dried silicate was introduced, 1160 ml of mixed heptane and 840 ml of a heptane solution of triethylaluminum (0.60M) were added, and the mixture was stirred at room temperature. After 1 hour, the mixture was washed with mixed heptane to adjust the silicate slurry to 2,000 ml. Next, 9.6 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added to the silicate slurry prepared above and reacted at 25 ° C. for 1 hour. In parallel, (r) -dichloro [1,1′-dimethylsilylenebis {2-methyl-4- (4-chlorophenyl) -4H-azurenyl}] zirconium 2,177 mg (0.3 mmol) and mixed heptane (870 ml) were added. , 33.1 ml of a heptane solution of triisobutylaluminum (0.71M) and reacted at room temperature for 1 hour, the mixture was added to the silicate slurry, stirred for 1 hour, and then mixed with heptane to add 5,000 ml. Adjusted to.

(Preliminary polymerization / washing)
Subsequently, the temperature inside the tank was raised to 40 ° C., and when the temperature became stable, propylene was supplied at a rate of 100 g / hour to maintain the temperature. After 4 hours, the propylene supply was stopped and maintained for another 2 hours.
After the completion of the prepolymerization, residual monomers were purged, stirring was stopped, and the mixture was allowed to stand for about 10 minutes, and 2,400 ml of the supernatant was decanted. Subsequently, 9.5 ml of a heptane solution of triisobutylaluminum (0.71 M / L) and 5,600 ml of a mixed heptane were added, and the mixture was stirred at 40 ° C. for 30 minutes and allowed to stand for 10 minutes, and then the supernatant was removed by 5,600 ml. It was This operation was repeated 3 times. When the component analysis of the final supernatant liquid was carried out, the concentration of the organoaluminum component was 1.23 mM / L, and the Zr concentration was 8.6 × 10 ⁻⁶ g / L, and the amount of Zr present in the supernatant liquid relative to the charged amount. The (weight ratio) was 0.018% by weight. Subsequently, 170 ml of a heptane solution of triisobutylaluminum (0.71M / L) was added, and then vacuum drying was carried out at 45 ° C. A prepolymerized catalyst containing 2.0 g of polypropylene per 1 g of catalyst was obtained.
Using this preliminary polymerization catalyst, a propylene-based resin composition was produced according to the following procedure.

(Ii) First Polymerization Step A horizontal reactor (L / D = 6, internal volume 100 liter) having a stirring blade was sufficiently dried, and the inside was sufficiently replaced with nitrogen gas. 0.568 g / hr of the prepolymerized catalyst prepared by the above method (as the solid catalyst amount excluding the prepolymerized powder) was added to the upstream portion of the reactor while stirring at a rotation speed of 30 rpm in the presence of a polypropylene powder bed. Triisobutylaluminum was continuously supplied at 15.0 mmol / hr. The temperature of the reactor is kept at 65 ° C, the pressure is kept at 2.1 MPaG, and the monomer mixed gas is continuously reacted so that the ethylene / propylene molar ratio in the gas phase in the reactor is 0.07 and the hydrogen concentration is 100 ppm. It was circulated in the vessel to carry out gas phase polymerization. The polymer powder generated by the reaction was continuously withdrawn from the downstream portion of the reactor so that the amount of the powder bed in the reactor was constant. At this time, the amount of polymer withdrawn at the steady state was 10.0 kg / hr.
When the propylene-ethylene random copolymer obtained in the first polymerization step was analyzed, the MFR was 6.0 g / 10 minutes and the ethylene content was 2.2% by weight.

(Iii) Second Polymerization Step A propylene-ethylene random copolymer extracted from the first step was continuously supplied to a horizontal reactor (L / D = 6, internal volume 100 liters) having a stirring blade. While stirring at a rotation speed of 25 rpm, the temperature of the reactor was kept at 70 ° C., the pressure was maintained at 2.0 MPaG, and the ethylene / propylene molar ratio in the gas phase in the reactor was 0.453 and the hydrogen concentration was 330 ppm. The monomer mixed gas was continuously circulated in the reactor to carry out gas phase polymerization. The polymer powder generated by the reaction was continuously withdrawn from the downstream portion of the reactor so that the amount of the powder bed in the reactor was constant. At this time, oxygen was supplied as an activity inhibitor so that the amount of polymer withdrawn was 17.9 kg / hr, and the amount of polymerization reaction in the second polymerization step was controlled. The activity was 31.4 kg / g-catalyst.
Table 1 shows various analytical results of the propylene resin composition PP (A-1) thus obtained.

Granulation Further, to 100 parts by weight of the obtained propylene resin PP (A-1), 0.05 part by weight of the following antioxidant 1 and 0.05 part by weight of the following antioxidant 2 were added, and a Henschel mixer ( Fully agitated and mixed with a product name), a twin screw extruder with a screw diameter of 25 mm (KZW-25 manufactured by Techno Bell Co., Ltd.), a screw rotation speed of 200 rpm, a discharge rate of 20 kg / hr, and an extruder temperature of 200 ° C. to melt and knead the strand. The molten resin extruded from the die is collected while being cooled and solidified in a cooling water tank, and a strand cutter is used to cut the strand into a diameter of about 2 mm and a length of about 3 mm to obtain a propylene-based resin composition PP (A-1). It was
Antioxidant 1:
Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (BASF Japan Ltd. trade name "Irganox 1010")
Antioxidant 2:
Tris (2,4-di-t-butylphenyl) phosphite (trade name “IRGAPHOS 168” manufactured by BASF Japan Ltd.)

(2) Ethylene-α-olefin copolymer (B)
Commercially available products PE (B-1) and PE (B-2) were used.
PE (B-1)
Product name "Kernel KS340T" (metallocene ethylene-α-olefin copolymer) MFR3.5, density 0.880, melting peak temperature 60 ° C manufactured by Nippon Polyethylene Co., Ltd.
PE (B-2)
Product name "Kernel KF261T" (metallocene ethylene-α-olefin copolymer) MFR 2.2, density 0.898, melting peak temperature 91 ° C manufactured by Nippon Polyethylene Co., Ltd.

(3) Propylene resin (C)
Commercially available products PP (C-1), PP (C-3), PP (C-4) and PP (C-2) obtained in the following Production Example (C-2) were used.
PP (C-1): Product name "Novatech PP FL4" manufactured by Japan Polypro Co., Ltd.
Propylene homopolymer MFR 4.2, melting point 165 ° C
PP (C-2): the one obtained in Production Example (C-2) below. MFR 5.4, melting point 161 ° C
PP (C-3): Product name "Novatech PP FY4" manufactured by Japan Polypro Co., Ltd.
Propylene homopolymer MFR5, melting point 161 ° C
PP (C-4): Product name “Wintech WFW4” manufactured by Japan Polypro Co., Ltd.
Metallocene-based propylene-ethylene random copolymer MFR7, melting point 135 ° C

Production Example (C-2)
A polymer was obtained according to Production Example C-1 of JP2010-229256A. Further, with respect to 100 parts by weight of the obtained polymer, 0.05 parts by weight of the following antioxidant 1, 0.05 parts by weight of the following antioxidant 2 and calcium stearate (Ca-St manufactured by Nitto Kasei Co., Ltd.) were added. 0.02 parts by weight was added, and the mixture was sufficiently stirred and mixed with a Henschel mixer (trade name), a twin screw extruder having a screw diameter of 25 mm (KZW-25 manufactured by Technovel Co., Ltd.), a screw rotation speed of 200 rpm, a discharge rate of 20 kg / hr, Melt kneading at an extruder temperature of 200 ° C., the molten resin extruded from the strand die is taken while cooling and solidifying in a cooling water tank, and a strand cutter is used to cut the strand to a diameter of about 2 mm and a length of about 3 mm, thereby producing a propylene-based material. Resin PP (C-2) was obtained.
Antioxidant 1:
Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (BASF Japan Ltd. trade name "Irganox 1010")
Antioxidant 2:
Tris (2,4-di-t-butylphenyl) phosphite (trade name “IRGAPHOS 168” manufactured by BASF Japan Ltd.)

(4) Softener (D)
A commercial product SEBS (D-1) was used.
SEBS (D-1)
Kraton Polymer Japan G1645MO (MFR: 2 to 4.5 g / 10 minutes, styrene content: 11.5 to 13.5%)

(Example 1)
44% by weight of PP (A-1) pellets as component A, 30% by weight of PE (B-1) pellets as component B, 26% by weight of PP (C-1) pellets as component C, components A and B KZW-25 twin screw extruder manufactured by Technobel Co., Ltd. with a screw diameter of 25 mm is put into a plastic bag so that a total of 5 kg and component C are put in a plastic bag, and the bag is shaken by hand vertically and horizontally to thoroughly mix the contents. At 350 rpm, a discharge rate of 20 kg / hr, and an extruder temperature of 200 ° C., the molten resin extruded from the strand die is cooled and solidified in a cooling water tank, and the strand is cut using a strand cutter. A propylene-based resin composition (X-1) pellet was obtained by cutting into a diameter of about 2 mm and a length of about 3 mm.
The obtained pellets are put into all extruders of a single-screw extruder with a diameter of 30 mm for the middle layer and a single-screw extruder with a diameter of 18 mm for the outer and inner layers, and set from a circular die with a diameter of 50 mm and a lip width of 1.0 mm. Extrusion at a temperature of 220 ° C., water cooling with a water cooling ring adjusted to 10 ° C., water-cooled inflation molding was performed at a speed of 2.3 m / min so that the folding width was 92 mm, and a 280 μm-thick substantially single piece was formed. A cylindrical sheet having a layer structure was obtained.
Next, the obtained tubular sheet was heat-treated by the above-mentioned method, and then held in an atmosphere of 23 ° C. and 50% RH for 48 hours or more, and then the physical properties of the single-layer sheet were evaluated. The evaluation results are shown in Table 2 below.

(Example 2)
The same operation as in Example 1 was performed except that PP (A-1) was changed to 40% by weight and PP (C-1) was changed to 30% by weight. The evaluation results are shown in Table 2.

(Example 3)
The same operation as in Example 1 was performed except that PE (B-1) was changed to PE (B-2). The evaluation results are shown in Table 2.

(Example 4)
The same operation as in Example 3 was performed except that PP (A-1) was changed to 40% by weight and PP (C-1) was changed to 30% by weight. The evaluation results are shown in Table 2.

(Example 5)
The same operation as in Example 3 was performed except that PP (A-1) was changed to 48% by weight and PP (C-1) was changed to 22% by weight. The evaluation results are shown in Table 2.

(Example 6)
28% by weight of PP (A-1) pellets as component A, 24% by weight of PE (B-2) pellets as component B, 30% by weight of PP (C-1) pellets as component C, SEBS (as component D D-1) Pellet 18% by weight was put in a polybag so that the total amount of component A, component B, component C and component D was 5 kg, and the whole bag was shaken by hand vertically and horizontally to thoroughly stir the contents. Blended, melted and kneaded at a screw rotation speed of 350 rpm, a discharge rate of 20 kg / hr, and an extruder temperature of 200 ° C. with a Techno Bell KZW-25 twin screw extruder having a screw diameter of 25 mm, and the molten resin extruded from the strand die is The propylene-based resin composition (with a diameter of about 2 mm and a length of about 3 mm was cut using a strand cutter while being cooled and solidified in a cooling water tank, and taken out. -6) to obtain pellets. The propylene-based resin composition (X-6) contained 34.1% by weight of component A, 29.3% by weight of component B, and 29.3% by weight of component C in 100 parts by weight in total of the components A, B and C. It accounts for 36.6% by weight, and 22 parts by weight of the component D is mixed with 100 parts by weight of the total of the components A, B and C.
The obtained pellets are put into all extruders of a single-screw extruder with a diameter of 30 mm for the middle layer and a single-screw extruder with a diameter of 18 mm for the outer and inner layers, and set from a circular die with a diameter of 50 mm and a lip width of 1.0 mm. Extrusion at a temperature of 220 ° C., water cooling with a water cooling ring adjusted to 10 ° C., water-cooled inflation molding was performed at a speed of 2.3 m / min so that the folding width was 92 mm, and a 280 μm-thick substantially single piece was formed. A cylindrical sheet having a layer structure was obtained.
Next, the obtained tubular sheet was heat-treated by the above-mentioned method, and then held in an atmosphere of 23 ° C. and 50% RH for 48 hours or more, and then the physical properties of the single-layer sheet were evaluated. The evaluation results are shown in Table 2 below.

(Comparative Example 1)
58% by weight of PP (A-1) pellets as component A, 27% by weight of PE (B-1) pellets as component B, 15% by weight of PP (C-2) pellets as component C, components A and B KZW-25 twin screw extruder manufactured by Technobel Co., Ltd. with a screw diameter of 25 mm is put into a plastic bag so that a total of 5 kg and component C are put in a plastic bag, and the bag is shaken by hand vertically and horizontally to thoroughly mix the contents. At 350 rpm, a discharge rate of 20 kg / hr, and an extruder temperature of 200 ° C., the molten resin extruded from the strand die is cooled and solidified in a cooling water tank, and the strand is cut using a strand cutter. A propylene-based resin composition (X-7) pellet was obtained by cutting into a diameter of about 2 mm and a length of about 3 mm.
The obtained pellets are put into all extruders of a single-screw extruder with a diameter of 30 mm for the middle layer and a single-screw extruder with a diameter of 18 mm for the outer and inner layers, and set from a circular die with a diameter of 50 mm and a lip width of 1.0 mm. Extrusion at a temperature of 220 ° C., water cooling with a water cooling ring adjusted to 10 ° C., water-cooled inflation molding was performed at a speed of 2.3 m / min so that the folding width was 92 mm, and a 280 μm-thick substantially single piece was formed. A cylindrical sheet having a layer structure was obtained.
Next, the obtained tubular sheet was subjected to heat treatment by the above-mentioned method. However, since the blending amount of the component C was outside the range of the present invention, deformation was caused at 121 ° C sterilization.

(Comparative example 2)
The same operation as in Example 1 was performed except that PP (A-1) was changed to 63% by weight, PE (B-1) was changed to 27% by weight, and PP (C-1) was changed to 10% by weight. The evaluation results are shown in Table 2. Since the compounding amount of the component C was out of the range of the present invention, it was deformed at 121 ° C sterilization.

(Example 7) Example of recycling By the same operation as in Example 3, propylene-based resin composition (X-3) pellets were obtained.
50% by weight of the obtained (X-3) pellets and 50% by weight of the single layer sheet prepared in Example 3 were cut with scissors into a size of about 3 to 5 mm in length and about 2 to 3 mm in width. -3) Pellet and the cut product of the single-layer sheet were put in a plastic bag so that the total amount thereof was 4 kg, and the bag was shaken by hand up and down, left and right, and the contents were sufficiently stirred to blend the propylene resin composition ( X-9) was prepared. The propylene-based resin composition (X-9) was charged into all extruders of a single-screw extruder having a bore of 30 mm for the intermediate layer and a single-screw extruder having a bore of 18 mm for the outer layer and the inner layer, and the bore of 50 mm and the lip width of 1. Extruded from a 0 mm circular die at a set temperature of 220 ° C., water-cooled with a water-cooled ring adjusted to 10 ° C., water-cooled inflation molding was performed at a speed of 2.3 m / min so that a folding width of 92 mm was obtained. A substantially single-layered cylindrical sheet having a thickness of 280 μm was obtained. This substantially single-layered tubular sheet is obtained by recycling 50% by weight of the resin composition constituting the single-layered sheet of Example 3.
Next, the obtained tubular sheet was heat-treated by the above-mentioned method, and then held in an atmosphere of 23 ° C. and 50% RH for 48 hours or more, and then the physical properties of the single-layer sheet were evaluated. The evaluation results are shown in Table 3 below. The physical properties were almost the same as those in Example 3.

Reference Example 1 Example of Laminated Virgin 70% by weight of PP (A-1) pellets, 20% by weight of PE (B-1) pellets and 10% by weight of PP (C-3) pellets were used as a resin for the intermediate layer. Put PP (A-1), PE (B-1) and PP (C-3) in a plastic bag so that the total weight is 5 kg, and shake the bag by hand vertically and horizontally to thoroughly stir the contents. Blended, melted and kneaded at a screw rotation speed of 350 rpm, a discharge rate of 20 kg / hr, and an extruder temperature of 200 ° C. with a Techno Bell KZW-25 twin screw extruder having a screw diameter of 25 mm, and the molten resin extruded from the strand die is Then, the propylene-based resin composition (X-10) pellets were obtained by taking out while cooling and solidifying in a cooling water tank and cutting the strand into a diameter of about 2 mm and a length of about 3 mm using a strand cutter. .
As the resin for the inner layer, 90% by weight of PP (C-4) pellets and 10% by weight of PE (B-1) pellets were added so that the total amount of PP (C-4) and PE (B-1) was 5 kg. Put in a plastic bag, shake the bag by hand up and down, left and right, and stir the contents sufficiently to blend, and use a Technovel KZW-25 twin screw extruder with a screw diameter of 25 mm, screw rotation speed 350 rpm, discharge The melted resin is melted and kneaded at an amount of 20 kg / hr and an extruder temperature of 200 ° C., and the molten resin extruded from the strand die is taken while cooling and solidifying in a cooling water tank. The propylene resin composition (Z-1) pellets were obtained by cutting.
The propylene-based resin composition (X-10) was applied to a single-screw extruder for the intermediate layer having a diameter of 30 mm, the propylene-based resin PP (C-3) was applied to a single-screw extruder for the outer layer having a diameter of 18 mm, and the propylene-based resin composition ( Z-1) was introduced into a single-screw extruder having an inner layer diameter of 18 mm, and the extruder rotation speed was adjusted so that outer layer thickness / intermediate layer thickness / inner layer thickness = 1/8/1. Extruded from a 1.0 mm circular die at a set temperature of 200 ° C., water-cooled with a water-cooled ring adjusted to 10 ° C., and water-cooled inflation molding was performed at a speed of 3.0 m / min so that a folding width was 92 mm. A tubular sheet having a thickness of 200 μm and a three-kind three-layer structure was obtained.
Next, the obtained cylindrical sheet was heat-treated by the above-mentioned method, and then held in an atmosphere of 23 ° C. and 50% RH for 48 hours or more, and then the physical properties of the three-kind three-layer sheet were evaluated. The evaluation results are shown in Table 3 below.

(Comparative Example 3) Example of recycling of laminated intermediate layer By the same operation as in Reference Example 1, propylene-based resin composition (X-10) pellets were obtained.
50% by weight of the obtained (X-10) pellets and 50% by weight of the three-kind three-layer sheet prepared in Reference Example 1 was cut with scissors into a size of about 3 to 5 mm in length and about 2 to 3 mm in width. (X-10) Pellets and the cut product of the three-kind three-layer sheet were put in a plastic bag so that the total amount was 4 kg, and the bag was shaken by hand up and down and left and right, and the contents were sufficiently agitated to blend the propylene resin composition. The product (X-11) was prepared.
The propylene-based resin composition (X-11) was applied to a single-screw extruder for the intermediate layer having a diameter of 30 mm, the propylene-based resin PP (C-3) was applied to a single-screw extruder for the outer layer having a diameter of 18 mm, and the propylene-based resin composition ( Z-1) was put into a single-screw extruder having an inner layer diameter of 18 mm, and the extruder rotation speed was adjusted so that outer layer thickness / intermediate layer thickness / inner layer thickness = 1/8/1. Extruded from a 1.0 mm circular die at a set temperature of 200 ° C., water-cooled with a water-cooled ring adjusted to 10 ° C., and water-cooled inflation molding was performed at a speed of 3.0 m / min so that a folding width was 92 mm. A tubular sheet having a thickness of 200 μm and a three-kind three-layer structure was obtained. The tubular sheet having the three-kind, three-layer structure is obtained by recycling the three-kind, three-layer sheet of Reference Example 1 to 50% by weight of the resin composition forming the intermediate layer of Reference Example 1.
Next, the obtained cylindrical sheet was heat-treated by the above-mentioned method, and then held in an atmosphere of 23 ° C. and 50% RH for 48 hours or more, and then the physical properties of the three-kind three-layer sheet were evaluated. The evaluation results are shown in Table 3 below. Since it was not a single-layer structure, the ratio of the components constituting the intermediate layer was changed, and the internal haze and tensile elastic modulus were significantly different from those in Reference Example 1, and were not suitable for recycling.

Claims (6)

A propylene-based resin single-layer sheet characterized by satisfying the following conditions.
The propylene-based resin composition (X) constituting the sheet is 15% by weight or more and less than 70% by weight of the propylene-based resin composition (A) satisfying the following conditions (A-i) to (A-iii), and the following conditions ( Ethylene-α-olefin copolymer (B) 10 to 35% by weight which satisfies B-i) to (B-ii), and propylene resin (C which satisfies the following conditions (C-i) to (C-ii) ) 20% by weight or more and 50% by weight or less (wherein the total amount of the propylene resin composition (A), the ethylene-α-olefin copolymer (B) and the propylene resin (C) is 100% by weight). %).
-Propylene resin composition (A):
(Ai) 30 to 70% by weight of propylene-α-olefin random copolymer (A1) having a melting peak temperature (Tm (A1)) of 125 to 145 ° C, and an ethylene content (E [A2]) of 7 to. 17% by weight of 70 to 30% by weight of a metallocene propylene-ethylene random copolymer (A2).
(A-ii) Melt flow rate (MFR (A): 230 ° C., 2.16 kg) is in the range of 0.5 to 20 g / 10 minutes.
(A-iii) In the temperature-loss tangent (tan δ) curve obtained by solid-state viscoelasticity measurement (DMA), the peak of the tan δ curve representing the glass transition observed in the range of −60 to 20 ° C. is a single value below 0 ° C. One peak is shown.
-Ethylene-α-olefin copolymer (B):
(B-i) The density is in the range of 0.860 to 0.910 g / cm ³ .
(B-ii) Melt flow rate (MFR (B): 190 ° C., 2.16 kg) is in the range of 0.1 to 20 g / 10 minutes.
・ Propylene resin (C):
(Ci) The melting peak temperature Tm (C) is in the range of 150 to 170 ° C.
(C-ii) The melt flow rate (MFR (C): 230 ° C., 2.16 kg) is in the range of 2 to 15 g / 10 minutes.   The propylene-based resin single-layer sheet according to claim 1, wherein the content of the propylene-based resin (C) is more than 25% by weight and 50% by weight or less. The propylene-based resin single-layer sheet according to claim 1 or 2, wherein the ethylene-α-olefin copolymer (B) has a density of 0.895 to 0.910 g / cm ³ .   The propylene-based resin single-layer sheet according to any one of claims 1 to 3, further comprising 1 to 30 parts by weight of a softening agent, based on 100 parts by weight of the propylene-based resin composition (X).   The propylene-based resin single-layer sheet according to any one of claims 1 to 4, wherein the propylene-based resin single-layer sheet is used for a packaging bag for heat treatment.   The propylene resin single-layer sheet according to claim 5, wherein the packaging bag for heat treatment is an infusion bag.