JP2005219485A - Laminated body and medical bag made of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated body with a highly hygienic property, superior in a flexibility, transparency and stab resistance and high in a temperature resistance and good in a bag drop strength at a low temperature environment and useful for forming a medical care bag containing a pharmaceutical liquid, a blood or the like and a bag for a medical care. <P>SOLUTION: The laminated body comprises at least an outer layer, a middle layer and an internal layer in the order wherein the outer layer is made of a polyolefinic resin (A) with a specified Vicat softening temperature, the middle layer is formed by a composition consisted of an ethylene-α-olefine copolymer (B) with an MFR of 0.1-20 g/10 min and a density of 0.880-0.930 g/cm<SP>3</SP>of 85-97 wt.% and an HDPE (C) with an MFR of 0.1-20 g/10 min and a density of 0.940-0.980 g/cm<SP>3</SP>of 3-15 wt.% and the internal layer is formed by a composition (b) consisted of the component (B) of 80-95 wt.% and the component (C) of 5-20 wt.% and further the content of the HDPE in the composition (a) and the content of the HDPE in the composition (b) satisfy a specified relational expression. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminate excellent in hygiene, flexibility, transparency, puncture strength, heat resistance, bag drop strength, heat sealability, and the like, and a medical bag containing a drug solution, blood, and the like comprising the laminate.

  The medical bag is required to have transparency so that the content liquid can be visually recognized and from the viewpoint of dripping of the content liquid, flexibility, heat resistance such as sterilization and heat resistance that does not impair the flexibility. As a resin material having the above requirements and having good hygiene, a polyethylene laminate has been studied and many proposals have been made.

For example, the inner and outer layers are made of linear low density polyethylene which is an ethylene / α-olefin copolymer having a density of 0.910 to 0.940 g / cm ³ , and the intermediate layer is 0.880 to 0.905 g / cm ^3. A three-layer structure comprising a linear low-density polyethylene which is an ethylene / α-olefin copolymer having a density of at least 0.01 g / cm ³ between the inner layer, the outer layer and the intermediate layer A plastic container has been proposed (see, for example, Patent Document 1). However, the plastic container has a big problem that the heat resistance is not sufficient. In particular, when the temperature condition of the sterilization treatment is set to a severe condition of 120 ° C. or higher, the molded product has reduced transparency and flexibility.

An outer layer formed of linear polyethylene having a density of 0.910 g / cm ³ or more and less than 0.950 g / cm ³ ; and an inner layer formed of linear polyethylene having a density of 0.940 g / cm ³ or less; And at least one linear polyethylene having a density of 0.920 g / cm ³ or less between the outer layer and the inner layer and having a density different from that of the linear polyethylene forming the outer layer and the inner layer. A linear polyethylene composition comprising an intermediate layer portion including an intermediate layer, and at least one of these layers includes 5 to 55% by weight of high-density polyethylene having a density of 0.950 g / cm ³ or more. There has been proposed a resin laminate characterized by being formed of (see, for example, Patent Document 2).
Furthermore, the outer layer is formed of a polyolefin-based resin material having a specific Vicat softening temperature, and the inner layer is formed of a polyethylene-based material mainly composed of an ethylene / α-olefin copolymer containing a low crystal component and a high crystal component. A laminated body has been proposed (see, for example, Patent Document 3).
However, medical bags made of these laminates have improved heat resistance and improved transparency, but not enough to improve flexibility. In order to further improve heat resistance, even if high-density polyethylene is increased, the piercing strength and drop-off bag strength will deteriorate this time. Therefore, the flexibility and transparency are excellent, and the heat resistance is high. A medical bag excellent in strength and bag breaking strength at the time of dropping a bag and excellent in heat sealability could not be achieved by a conventional multilayer medical bag.
JP-A 63-248633 JP-A-6-246886 JP 2001-162746 A

  In view of the above problems, the present invention is highly hygienic, excellent in flexibility, transparency and puncture strength, has high heat resistance, and has a good bag drop strength in a low temperature atmosphere. It is an object of the present invention to provide a laminated body for medical bags that contains blood and the like, and a medical bag comprising the same.

  As a result of intensive studies to solve the above problems, the present inventors laminated a specific ethylene / α-olefin copolymer composition containing a specific polyolefin-based resin material and a specific high-density polyethylene, and water-cooled inflation. By molding, it contains chemicals, blood, etc. that have high hygiene, excellent flexibility, transparency and puncture strength, high heat resistance, and good bag drop strength in a low-temperature atmosphere. The knowledge that a laminate for medical bags can be obtained has led to the completion of the present invention.

That is, according to the first aspect of the present invention, the laminate includes at least the outer layer, the intermediate layer, and the inner layer in this order,
The outer layer is formed of a polyolefin resin material (A) having a Vicat softening temperature of 90 to 140 ° C.,
The intermediate layer has a melt flow rate of 85 to 97% by weight with an ethylene / α-olefin copolymer (B) having a melt flow rate of 0.1 to 20 g / 10 min and a density of 0.880 to 0.930 g / cm ^3. An ethylene / α-olefin copolymer composition (a) comprising ³ to 15% by weight of high density polyethylene (C) having a rate of 0.1 to 20 g / 10 min and a density of 0.940 to 0.980 g / cm ³ )
The inner layer has an melt flow rate of 80 to 95% by weight of an ethylene / α-olefin copolymer (A) having a melt flow rate of 0.1 to 20 g / 10 min and a density of 0.880 to 0.930 g / cm ^3. Is an ethylene / α-olefin copolymer composition (b) comprising 5 to 20% by weight of high density polyethylene (C) having a density of 0.1 to 20 g / 10 min and a density of 0.940 to 0.980 g / cm ^3. Formed,
And the content [HDPEa] (weight%) of the high density polyethylene in the ethylene / α-olefin copolymer composition (a) and the content of the high density polyethylene in the ethylene / α-olefin copolymer composition (b) There is provided a laminate characterized in that [HDPEb] (% by weight) satisfies the following formulas (1) and (2).
0 <[HDPEb] − [HDPEa] <15 (1)
10 <[HDPEb] + [HDPEa] <30 (2)

  According to the second invention of the present invention, in the first invention, at least one of the intermediate layer or the inner layer ethylene / α-olefin copolymer (B) is produced using a metallocene catalyst, and A laminate having a ratio (Mw / Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn) of 1.5 to 4.0 is provided.

  According to the third invention of the present invention, in the first or second invention, the polyolefin resin material (A) has an extrapolated melting end temperature of the melting peak obtained by differential scanning calorimetry (DSC). A laminate is provided that is a high-pressure low-density polyethylene at 110 to 125 ° C.

According to the fourth invention of the present invention, in any of the first to third inventions, the melting peak obtained by differential scanning calorimetry (DSC) of ethylene / α-olefin copolymerization (B) is compensated. An outer melting end temperature (Tm _b ) and an extrapolated melting end temperature (Tm _c ) of the high-density polyethylene (C) satisfy the following formula (3).
15 ≦ (Tm _c −Tm _b ) ≦ 50 (3)

According to the fifth invention of the present invention, in any one of the first to fourth inventions, the Olsen bending stiffness of the resin composition constituting the outer layer, the intermediate layer, and the inner layer satisfies the following formula (4): A laminate is provided.
Intermediate layer <Inner layer <Outer layer (4)

  According to a sixth aspect of the present invention, there is provided a medical bag comprising the laminate according to any one of the first to fifth aspects.

  The laminate of the present invention not only has good hygiene, but also has excellent flexibility, transparency and puncture strength after 115 ° C. sterilization treatment, and heat resistance, bag drop strength that causes problems during transportation and handling In addition, since it adheres to the upper seal bar during sealing, it can be suitably used as a soft container in the medical field such as a medical bag, particularly an infusion bag.

  The laminate of the present invention is a laminate comprising at least an outer layer, an intermediate layer, and an inner layer in this order. The outer layer is formed of a polyolefin resin material (A), and the intermediate layer and the inner layer are ethylene / α-olefin copolymers. It is formed by ethylene / α-olefin copolymer compositions (a) and (b) each containing (B) and high-density polyethylene (C) at specific ratios. The components, laminates, etc. constituting each layer will be described below.

1. Outer layer (1) Polyolefin resin material (A)
The polyolefin resin material (A) used for the outer layer of the laminate of the present invention is a polyolefin resin having a Vicat softening temperature of 90 to 140 ° C, preferably 95 ° C to 130 ° C, more preferably 100 to 120 ° C. If the Vicat softening temperature is less than 90 ° C., adhesion to the upper seal bar occurs during sealing, which is not preferable. Moreover, when it exceeds 140 degreeC, a softness | flexibility is lacking and it is not preferable.
Further, the Vicat softening temperature Ta of the component (A) is related to the Vicat softening temperature Tb of the inner layer resin composition.
Tb <Ta ≦ 140 ° C.
Those satisfying the conditions are preferably used. When the Vicat softening temperature Ta of the polyolefin resin material of the outer layer is equal to or lower than the Vicat softening temperature Tb of the resin composition of the inner layer, when the bag is made (the inner layer and the inner layer are heat-sealed by the seal bar), It is not preferable because it is removed (the outer layer adheres to the upper seal bar) and the working efficiency is lowered.
The Vicat softening temperature is a value measured according to JIS-K7206-1974.

The polyolefin resin material (A) satisfying the above characteristics includes (i) a high-pressure low-density polyethylene having an extrapolated melting end temperature of 110 ° C. or higher at a melting peak obtained by differential scanning calorimetry (DSC) described below. (Ii) A copolymer of ethylene having a density of 0.910 g / cm ³ or more and an α-olefin having ^{3 to} 18 carbon atoms, or a mixture thereof.

(I) High pressure method low density polyethylene The high pressure method low density polyethylene which can be used as a polyolefin resin material used for the outer layer is an extrapolated melting end temperature (Tm _a ) of _a melting peak obtained by differential scanning calorimetry (DSC). Is 110 ° C. or higher, preferably 110 to 125 ° C., more preferably 113 to 120 ° C. Tm _a heat resistance is deteriorated at below 110 ° C..
The measurement of Tm _a uses a Seiko Co. differential scanning calorimeter, the sample amount takes a 5.0 mg, was held 5 minutes at 170 ° C., crystals 10 ° C. / min cooling speed to -10 ° C. It is held for 1 minute after being converted to an extrapolated melting end temperature at the melting peak when it is further melted at a heating rate of 10 ° C./min.

The MFR of the high-pressure low-density polyethylene is not particularly limited, but is preferably 0.05 to 100 g / 10 minutes, more preferably 0.1 to 50 g / 10 minutes, and particularly preferably 0.2 to 20 g / 10 minutes. It is. When the MFR value is within this range, there is an advantage that the film formation is stable.
Here, the measurement of MFR is performed according to JIS-K6922-2: 1997 annex (190 degreeC, 21.18N load).

Further, the density of the high-pressure low-density polyethylene is not particularly limited, but is preferably 0.915 to 0.940 g / cm ³ , more preferably 0.920 to 0.935 g / cm ³ . If the density is within this range, the heat resistance and flexibility are excellent.
Here, the density is determined according to JIS-K6922-2: 1997 appendix (in the case of low density polyethylene) (23 ° C.).

  The high-pressure method low-density polyethylene may be one type or a mixture of two or more types.

(Ii) Copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms A copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms that can be used as a polyolefin-based resin material used for the outer layer has a density of Is 0.910 g / cm ³ or more, preferably 0.910 to 0.940 g / cm ³ , more preferably 0.910 to 0.935 g / cm ³ . If the density is within this range, the heat resistance, flexibility, and transparency are excellent.
Here, the density is measured according to JIS-K6922-2: 1997 appendix (in the case of low density polyethylene) (23 ° C.).

Moreover, although MFR of the copolymer of ethylene and C3-C18 alpha olefin is not specifically limited, Preferably it is 0.05-100 g / 10min, More preferably, it is 0.1-50 g / 10min, Most preferably, it is 0.2-20 g / 10min. If the MFR value is within this range, there is an advantage that the film formation is stable.
Here, the measurement of MFR is performed according to JIS-K6922-2: 1997 annex (190 degreeC, 21.18N load).

  As a copolymer of ethylene and a C3-C18 alpha olefin, what was manufactured using the Ziegler type catalyst and what was manufactured using the metallocene catalyst can be mentioned. In addition, the 1 type, or 2 or more types of mixture may be sufficient as the copolymer of ethylene and a C3-C18 alpha olefin.

As the polyolefin-based resin material used for the outer layer, among the components (i) or (ii), the resin is prevented from dripping particularly at the time of start-up at the time of molding, the bubble is stabilized, etc. From the viewpoint, (i) a high-pressure low-density polyethylene having an extrapolated melting end temperature of a melting peak obtained by differential scanning calorimetry (DSC) of 110 ° C. or higher is preferable.
Furthermore, the melt tension is preferably 0.8 to 20 g, more preferably 0.9 to 15 g, and particularly preferably 1.0 to 10 g. If the melt tension is within this range, there is an advantage that the moldability is excellent because the resin is prevented from dripping at the time of start-up at the time of molding and the bubbles are stabilized.

(2) Other components In the outer layer of the laminate of the present invention, an auxiliary additive component generally used for a resin composition can be blended as necessary within a range that does not significantly impair the effects of the present invention. Examples of such auxiliary additive components include antioxidants (in particular, phenol-based and phosphorus-based antioxidants are preferable), anti-blocking agents, neutralizing agents, and heat stabilizers.
In order to impart flexibility to the total weight of the component (A) without impairing the effects of the present invention and / or to improve interlayer adhesion, polymerization is performed with a Ziegler-based or metallocene-based catalyst. A crystalline ethylene / α-olefin copolymer and / or a rubber compound such as an ethylene / α-olefin elastomer such as EBR or EPR or a styrene elastomer such as SEBS or hydrogenated styrene block copolymer; 75% by weight can also be blended.

2. Intermediate Layer The intermediate layer of the laminate of the present invention is a layer comprising an ethylene / α-olefin copolymer composition (a) containing an ethylene / α-olefin copolymer (B) and high-density polyethylene (C). is there. Each component will be described.
(1) Ethylene / α-olefin copolymer (B)
The ethylene / α-olefin copolymer (B) used for the intermediate layer of the laminate of the present invention is a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms. The copolymer has the following characteristics (B1) to (B2), and is preferably an ethylene / α-olefin copolymer that is polymerized with a metallocene catalyst and further has characteristics (B3) to (B4). is there. Hereinafter, the constituent monomer, the polymerization method, and the characteristics of the monomer will be described in order.

(I) Monomer configuration The ethylene / α-olefin copolymer used in the present invention is a random copolymer of ethylene and an α-olefin mainly composed of a structural unit derived from ethylene.
The α-olefin used as a comonomer is preferably an α-olefin having 3 to 12 carbon atoms. Specifically, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene- 1 etc. can be mentioned. Specific examples of such ethylene / α-olefin copolymers include ethylene / propylene copolymers, ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, ethylene / 1-octene copolymers, ethylene -4-methyl-pentene-1 copolymer is mentioned. Moreover, 1 type or 2 or more types of combinations may be sufficient as an alpha olefin. When two types of α-olefins are combined to form a terpolymer, ethylene / propylene / hexcenter polymer, ethylene / butene / hexcenter polymer, ethylene / propylene / octene terpolymer, and ethylene / butene / octene terpolymer may be mentioned. .
The amount of ethylene units in the ethylene / α-olefin copolymer will be described later as the characteristic (B4).

(Ii) Polymerization Catalyst and Polymerization Method The ethylene / α-olefin copolymer used in the present invention can be produced using a Ziegler catalyst, a vanadium catalyst, a metallocene catalyst, preferably a metallocene catalyst. Examples of the production method include a high-pressure ion polymerization method, a gas phase method, a solution method, and a slurry method.

(Iii) Characteristics (B1) Melt flow rate (MFR)
MFR (190 degreeC, 21.18N load) of the ethylene * alpha-olefin used by this invention is 0.1-20 g / 10min, Preferably it is 0.5-10 g / 10min, More preferably, it is 1 0.0 to 5 g / 10 min. When the MFR of the ethylene / α-olefin copolymer is less than 0.1 g / 10 min, the resin pressure is high and the moldability is poor, and when it exceeds 20 g / 10 min, the bubbles become unstable during inflation molding and the moldability is poor. become.
Here, the MFR of the ethylene / α-olefin copolymer is measured according to JIS-K6922-2: 1997 appendix (190 ° C., 21.18 N load).

(B2) Density The density of the ethylene / α-olefin copolymer used in the present invention is 0.880 to 0.930 g / cm ³ , preferably 0.885 to 0.925 g / cm ³ , and more preferably 0.890. ˜0.920 g / cm ³ . When the density of the ethylene / α-olefin copolymer is less than 0.880 g / cm ³ , poor transparency occurs after 115 ° C. treatment, and when it exceeds 0.930 g / cm ³ , it is preferable because of poor transparency and reduced flexibility. Absent.
Here, the density of the ethylene / α-olefin copolymer is measured at 23 ° C. in accordance with JIS-K6922-2: 1997 appendix (in the case of low density polyethylene).

(B3) Weight average molecular weight (Mw) / Number average molecular weight (Mn)
The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the ethylene / α-olefin copolymer used in the present invention is 1.5 to 4.0, preferably 1.8 to 3.3. When Mw / Mn exceeds the above range, the transparency is lowered, which is not preferable. When it is less than the above range, processability is deteriorated such that the extrusion load increases and shark skin is easily generated.
Examples of a method for setting Mw / Mn within a predetermined range include a method for selecting an appropriate metallocene catalyst.
Mw / Mn is measured by gel permeation chromatography (GPC), and the measurement conditions are as follows.

Apparatus: Waters GPC 150C type detector: MIRAN 1A infrared spectrophotometer (measurement wavelength: 3.42 μm)
Column: Showa Denko 3 AD806M / S (column calibration is Tosoh monodisperse polystyrene (0.5 mg / ml solution each of A500, A2500, F1, F2, F4, F10, F20, F40, F288) The logarithm of the elution volume and molecular weight was approximated by a quadratic equation, and the molecular weight of the sample was converted to polyethylene using the viscosity equation of polystyrene and polyethylene, where the coefficient of the viscosity equation of polystyrene was α = 0. 723, log K = −3.967, and polyethylene has α = 0.733 and log K = −3.407.)
Measurement temperature: 140 ° C
Concentration: 20 mg / 10 mL
Injection volume: 0.2ml
Solvent: orthodichlorobenzene Flow rate: 1.0 ml / min.

(B4) Content of α-olefin The content of α-olefin in the ethylene / α-olefin copolymer used in the present invention is preferably 5 to 40% by weight, more preferably 7 to 35% by weight, even more preferably. Is 9-30% by weight. When the α-olefin content is low, the impact strength and flexibility of the film cannot be obtained, and when it is too high, the heat resistance is impaired. Here, the content of α-olefin is a value measured by ¹³ C-NMR method under the following conditions.
Device: JEOL-GSX270 manufactured by JEOL
Concentration: 300 mg / 2 mL
Solvent: Orthodichlorobenzene

  The ethylene / α-olefin copolymer may be one kind or a mixture of two or more kinds.

(2) High density polyethylene (C)
The high density polyethylene (C) used for the intermediate layer of the laminate of the present invention is a high density polyethylene having the following properties (C1) to (C2).
(I) Characteristics (C1) Melt flow rate (MFR: 190 ° C., 21.18 N load)
The MFR of the component (C) used in the present invention is 0.1 to 20 g / 10 minutes, preferably 1 to 20 g / 10 minutes, and more preferably 2 to 20 g / 10 minutes. If the MFR of the component (C) is less than 0.1 g / 10 minutes, the dispersibility in the component (B) is lacking, so the heat resistance during the 115 ° C. treatment is not improved, which is not preferable. On the other hand, if the MFR exceeds 20 g / 10 min, the film formation stability is insufficient, which is not preferable.
Here, MFR of high density polyethylene is measured based on JIS-K6922-2: 1997 appendix (190 degreeC, 21.18N load).

(C2) Density The density of the component (C) used in the present invention is 0.940 to 0.980 g / cm ³ , preferably 0.950 to 0.980 g / cm ³ , and more preferably 0.960 to 0.980 g. / Cm ³ . When the density of the component (C) is less than 0.940 g / cm ³ , the effect of improving heat resistance is not sufficient, and it is difficult to produce polyethylene exceeding 0.980 g / cm ³ .
Here, the density of a component (C) is measured based on JIS-K6922-2: 1997 annex (23 degreeC).

  In addition, 1 type or a 2 or more types of mixture may be sufficient as high density polyethylene.

(Ii) Polymerization Method and Polymerization Catalyst The production of component (C) of the present invention is not particularly limited with respect to the polymerization method and catalyst as long as a polymer having the desired physical properties can be produced, but polyethylene obtained by an intermediate pressure process. Is preferred.
For catalysts, Ziegler type catalysts (ie, 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, especially alumoxanes). Based on the combination).
The Ziegler-type catalyst can be obtained by a usual polymerization method using, for example, a combination catalyst of a solid catalyst component and an organoaluminum compound containing magnesium halide, titanium halide, and an electron donor compound as components.
The shape of polyethylene is not limited, and may be any of pellets, powders, and waxes.

(3) Relationship between component (B) and component (C) Component (B) and component (C) in composition (a) are subjected to extrapolation of the melting peak obtained by differential scanning calorimetry (DSC). It is preferable that the extrapolated melting end temperature (Tm _c ) of the temperature (Tm _b ) and the component (C) satisfy the following formula (3).
15 ≦ (Tm _c −Tm _b ) ≦ 50 (3)
If the difference between the components extrapolation melting completion temperature of melting peak _(B) (Tm b) and extrapolated ending melting temperature of component _(C) (Tm c) is less than 15, is not sufficient heat resistance during sterilization , More than 50 is not preferable because it lacks flexibility.
The measurement of Tm _b and Tm _c uses a Seiko Co. differential scanning calorimeter, the sample amount takes a 5.0 mg, was held 5 minutes at 170 ° C., cooling of 10 ° C. / min to -10 ° C. After crystallization at a speed, the temperature is held for 1 minute, and further evaluated by the extrapolated melting end temperature of the melting peak when melted at a heating rate of 10 ° C./min.
When there were a plurality of melting peaks and a plurality of melting peaks overlapped, the extrapolation melting end temperature for the peak appearing on the highest temperature side was determined.
The extrapolation melting end temperature is determined according to JIS-K-7121.

(4) Other additive components The resin composition (a) used for the intermediate layer of the present invention can be blended with other additional optional components as long as the effects of the present invention are not significantly impaired. As such optional components, antioxidants used in ordinary polyolefin resin materials (in particular, phenol-based and phosphorus-based antioxidants are preferable), antiblocking agents, neutralizing agents, heat stabilizers, crystals Examples thereof include a nucleating agent, a clarifying agent, a lubricant, a coloring agent, a dispersing agent, a peroxide, a filler, and a fluorescent brightening agent.
In order to give flexibility, crystalline ethylene / α-olefin copolymers polymerized by Ziegler type catalysts or metallocene catalysts and / or ethylene / α-olefin elastomers such as EBR and EPR, SEBS, HSBR, etc. In order to improve the bubble stability at the time of molding, high pressure method low density polyethylene (HP-LD) can be blended.
Further, the blending ratio of the high pressure method low density polyethylene is 3 to 70 parts by weight with respect to 100 parts by weight of the resin mixture of the component (B) and the component (C), and the crystallinity polymerized by the Ziegler type catalyst or the metallocene catalyst. In the case of the ethylene / α-olefin copolymer and rubber compound, about 3 to 240 parts by weight are preferable.

(5) Blending ratio of component (B) and component (C) The blending ratio of component (B) and component (C) in the ethylene / α-olefin copolymer composition (a) is 85-85. It mix | blends so that a component (C) may be 3 to 15 weight% with respect to 97 weight%, Preferably a component (C) will be 3 to 10 weight% with respect to 90 to 97 weight% of a component (B). If the ratio of the component (C) is larger than the above range, the flexibility and bag drop strength are lowered, which is not preferable. Moreover, since the heat resistance falls when the mixture ratio of a component (C) is smaller than the said range, it is unpreferable.

(6) Preparation method of ethylene / α-olefin copolymer composition (a) The ethylene / α-olefin copolymer composition (a) comprises components (B) and (C) prepared from a conventional resin composition. It can mix | blend according to a manufacturing method and can adjust by melt-kneading as needed.
More specifically, the component (B) and the component (C) may be dry blended in advance, and the blended product may be put into a hopper of a molding machine as it is. Further, the blend can be melted and kneaded using an extruder, a Brabender plastograph, a Banbury mixer, a kneader blender, etc., and formed into pellets by a commonly used method to produce a film or sheet.

3. Inner layer The inner layer of the laminate of the present invention is a layer composed of an ethylene / α-olefin copolymer composition (b) containing an ethylene / α-olefin copolymer (B) and high-density polyethylene (C). Each component will be described.
(1) Ethylene / α-olefin copolymer (B)
The ethylene / α-olefin copolymer (B) used for the inner layer of the laminate of the present invention is the same copolymer as the ethylene / α-olefin copolymer used for the intermediate layer, and is the same as the intermediate layer. It may be different or different.
The ethylene / α-olefin copolymer may be one kind or a mixture of two or more kinds.

(2) High density polyethylene (C)
The high density polyethylene (C) used for the inner layer of the laminate of the present invention is the same as the high density polyethylene used for the intermediate layer described above, and may be the same as or different from the intermediate layer.
In addition, 1 type or a 2 or more types of mixture may be sufficient as high density polyethylene.

(3) Relationship between component (B) and component (C) Component (B) and component (C) in the ethylene / α-olefin copolymer composition (b) are obtained by differential scanning calorimetry (DSC). it is extrapolated ending melting temperature of the extrapolated ending melting temperature of the melting peak (Tm _b) to component (C) (Tm _c) preferably satisfies the following formula (3).
15 ≦ (Tm _c −Tm _b ) ≦ 50 (3)
If the difference between the components extrapolation melting completion temperature of melting peak _(B) (Tm b) and extrapolated ending melting temperature of component _(C) (Tm c) is less than 15, is not sufficient heat resistance during sterilization , More than 50 is not preferable because it lacks flexibility.
The measurement of Tm _b and Tm _c uses a Seiko Co. differential scanning calorimeter, the sample amount takes a 5.0 mg, it was held 5 minutes at 170 ° C., of 10 ° C. / min to -10 ° C. cooling speed The crystal is held for 1 minute after being crystallized at, and evaluated by the extrapolated melting end temperature of the melting peak when melted at a heating rate of 10 ° C./min.

(4) Other additive components The ethylene / α-olefin copolymer composition (b) used for the inner layer of the present invention is blended with other additional optional components as long as the effects of the present invention are not significantly impaired. Can do. As such optional components, antioxidants used in ordinary polyolefin resin materials (in particular, phenol-based and phosphorus-based antioxidants are preferable), antiblocking agents, neutralizing agents, heat stabilizers, crystals Examples thereof include a nucleating agent, a clarifying agent, a lubricant, a coloring agent, a dispersing agent, a peroxide, a filler, and a fluorescent brightening agent.
In order to give flexibility, crystalline ethylene / α-olefin copolymers polymerized by Ziegler type catalysts or metallocene catalysts and / or ethylene / α-olefin elastomers such as EBR and EPR, SEBS, HSBR, etc. In order to improve the bubble stability at the time of molding, high pressure method low density polyethylene (HP-LD) can be blended.
Further, the blending ratio of the high pressure method low density polyethylene is 3 to 70 parts by weight with respect to 100 parts by weight of the resin mixture of the component (B) and the component (C), and the crystallinity polymerized by the Ziegler type catalyst or the metallocene catalyst. In the case of the ethylene / α-olefin copolymer and rubber compound, about 3 to 240 parts by weight are preferable.

(5) Blending ratio of component (B) and component (C) The blending ratio of component (B) and component (C) in the ethylene / α-olefin copolymer composition (b) is from component (B) 80 to It mix | blends so that a component (C) may be 5 to 20 weight% with respect to 95 weight%, Preferably, a component (C) will be 8 to 17 weight% with respect to 87 to 92 weight% of a component (B). If the ratio of the component (C) is larger than the above range, the flexibility and bag drop strength are lowered, which is not preferable. Moreover, since the heat resistance falls when the mixture ratio of a component (C) is smaller than the said range, it is unpreferable.

(6) Ratio of the (C) component amount of the intermediate layer and the (C) component amount ratio of the inner layer The component (C) used in the laminate of the present invention has a content in the intermediate layer and a content in the inner layer represented by the following formula (1) ) And formula (2) must be satisfied.
Blending ratio of component (C) in ethylene / α-olefin copolymer composition (a): HDPEa and blending ratio of component (C) in ethylene / α-olefin copolymer composition (b): HDPEb ,
0 <HDPEb-HDPEa <15 (1)
10 <HDPEb + HDPEa <30 (2)
And preferably 0 <HDPEb−HDPEa <12 (1) ′
13 <HDPEb + HDPEa <27 (2) ′
It is necessary to satisfy.
If the above relationship is not satisfied, the intermediate layer will be less flexible than the inner layer, the balance between flexibility and heat resistance will be poor, the laminate will not be flexible enough, the transparency will deteriorate due to poor heat resistance, and the piercing strength will be insufficient Etc. are not preferable.

(7) Preparation Method of Ethylene / α-Olefin Copolymer Composition (b) The ethylene / α-olefin copolymer composition (b) is obtained by mixing the component (B) and the component (C) with an ordinary resin composition. It can mix | blend according to a manufacturing method and can adjust by melt-kneading as needed.
Specifically, it is the same as in the case of the ethylene / α-olefin copolymer composition (a).

4). Laminate The laminate of the present invention may be any laminate as long as at least the outer layer, the intermediate layer, and the inner layer are laminated in this order. In addition to the outer layer, the intermediate layer, and the inner layer, the laminate is generally used for such a laminate. Various layers can be provided as necessary. Specifically, an adhesive layer or a gas barrier layer such as EVOH can be provided between various layers.

Moreover, it is preferable that the Olsen bending stiffness of the resin material or composition constituting the outer layer, the intermediate layer, and the inner layer satisfy the relationship of the following formula (4).
Intermediate layer <Inner layer <Outer layer (4)
By satisfying the above relationship, it is possible to maintain a high balance of physical properties such as flexibility, heat resistance, and sealing properties.
In addition, Olsen bending stiffness is performed according to JIS-K7106-1995 using a 2 mm sheet of each resin produced under the following conditions.
The sample was preheated at 160 ° C. for 3 minutes and pressurized at 160 ° C. and 150 kgf / cm ^{2 for} 1 minute. Then, it cooled to room temperature at 14 degreeC / min, the 2 mm-thick press sheet was obtained, and it was set as the test piece.

  Further, the haze (HAZE) of the laminate of the present invention is preferably 30% or less, more preferably 25% or less after 115 ° C. treatment. If the value of HAZE exceeds 30%, the contents are not clearly visible, such as the contents are not clearly visible.

  Furthermore, as for the thickness of the laminated body of this invention, 100-700 micrometers is preferable. If it is in the said range, since the film excellent in transparency can be shape | molded stably, it is preferable. Furthermore, the laminate obtained in the present invention can be subjected to a surface treatment such as a corona discharge treatment or a flame treatment by a method usually used industrially.

There is no restriction | limiting in particular in the manufacturing method of the laminated body of this invention, Although it can carry out by a well-known method, manufacturing by a water cooling inflation method is preferable.
Specifically, the water-cooled inflation molding method in which the resin material for the outer layer, the intermediate layer, and the inner layer described above is coextruded using an extruder and a circular die, introduced into a water tank while being expanded by introducing air into a molten tube, and rapidly cooled. Is formed into a film. The conditions of the water-cooled inflation method are not particularly limited, but examples include a method of blowing downward and cooling with water confined inside, or using a sizing link or a water tank-type water cooling ring. The molding temperature is 160 to 280 ° C, preferably 170 to 230 ° C, and the water temperature for water cooling is 10 to 60 ° C, preferably 15 to 50 ° C.

5). Applications The laminate of the present invention can be used for medical bags, food packaging bags, and the like. In particular, it can be suitably used for 115 ° C. sterilization treatment requiring heat resistance. Specific applications of the medical bag include infusion bags, containers for injecting, discharging, and storing body fluids and drug solutions, peritoneal dialysis bags, artificial dialysis bags, and the like. Examples of food packaging bags include retort food bags.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The evaluation methods and resins used in the examples and comparative examples are as follows.

1. Evaluation method of resin physical properties (1) Melt flow rate (MFR): As described above, the MFR of the propylene / α-olefin random copolymer is JIS-K6922-2: 1997 appendix (190 ° C., 21.18 N load). Measured according to
(2) Vicat softening temperature Ta and Tb: Measured according to JIS-K7206-1974.
(3) Tm _b and Tm _c : As described above, measured by DSC.
(4) Mw / Mn: Measured by GPC as described above.
(5) Density: As described above, the density was measured according to JIS-K6922-2: 1997 appendix (23 ° C.).
(6) Olsen bending stiffness: As described above, measured according to JIS-K7106-1995.
(7) Melt tension: It is set as the stress at the time of taking a resin filament at the test temperature of 190 degreeC, the extrusion speed of 10 mm / min, and the take-up speed of 4 m / min in Toyo Seiki Capillograph 1-B. The die diameter used is 8.00 mm in length, 2.095 mm in inner diameter, and 9.50 mm in outer diameter.

2. Forming method of laminated body Three types of three-layer water-cooled inflation molding machine (die diameter: 100 mmφ, die lip: 3 mm, die temperature: 185 ° C.) manufactured by Plako Co., Ltd., outer layer and inner layer thickness of 50 μm, intermediate layer thickness of 150 μm, folding diameter A 180 mm tubular laminate was formed.

3. Laminate Evaluation Method (1) Heat Resistance: A cylindrical laminate was cut into a size of 210 mm, and one of the cut out was heat sealed to form a bag. Next, 500 ml of pure water was filled therein, and the other side was heat-sealed and sealed. Sealing was performed such that the distance between the heat seal and the heat seal was 180 mm. The sample bag thus obtained is put into a high-temperature and high-pressure cooking sterilization tester (manufactured by Nisaka Manufacturing Co., Ltd., RCS / 40RTGN type) and then pressurized, the ambient temperature is increased to 115 ° C., and the temperature is adjusted. Hold for 30 minutes. Then, it cooled to about 40 degreeC and took out this sample bag from the testing machine. Hereinafter, this sterilized laminate (“sample bag”) is referred to as “sterilized laminate”.
The heat sealing was performed under the conditions of temperature: 200 ° C., pressure: 2 kg / cm ² , and time of 4 seconds.
The heat resistance of the sample bag was evaluated according to the following criteria.
○: Almost no wrinkles. Or not at all.
X: There are many wrinkles. Or, transparency is lowered.
(2) Haze: As described above, the haze was measured according to JIS-K7136-2000. The HAZE measurement was performed for both the molded laminate and the sterilized laminate. When measuring the HAZE of the laminate after sterilization, the water filled in the laminate was taken out and 2 hours later.
(3) Tensile modulus (MD): Based on ISO1184-1983, the tensile modulus of the laminate in the MD direction (film or sheet take-up direction) was measured. It shows that it is excellent in the softness, so that this value is small. In addition, the tensile elasticity modulus was performed about what drained water from the laminated body after sterilization (use the laminated body 48 hours after draining water).
(4) Bag drop strength: After sterilization, the laminates (2 pieces) were stored at 10 ° C. for 24 hours, and then dropped at a temperature from a height of 2 m onto a steel plate in parallel for evaluation. Evaluation was made according to the following criteria.
○: One or two laminated bodies were broken after sterilization.
X: The state did not change from before the drop test, and there was no problem with the two.
(5) Adhesion to the outer layer and upper seal bar: heat seal temperature: 160 ° C., seal pressure: 2 kg / cm ² , seal time: 3 seconds, seal bar width: laminated on the seal bar under heat seal conditions of 10 mm When the inner surfaces of the bodies were heat-sealed and the seal bar was raised, the case where the outer surface of the laminated body adhered to the upper seal bar was evaluated as x, and the case where it did not adhere was evaluated as ◯. In addition, when the outer surface of the laminate does not adhere to the upper seal bar, the optimum heat seal temperature is widened, so that not only the work efficiency is good, but also there are few troubles such as defective heat seal, which is excellent.
(6) Puncture strength: Measured with reference to the method described in Japanese Agricultural Standards (JAS) (Ministry of Agriculture and Forestry Notification No. 1019) of retort pouch foods.
As the test piece, a laminate after sterilization treatment was used. The outer layer was fixed on the surface. Fixing was performed so that the laminated body appeared as a circle having a diameter of 55 mm after sterilization.
A rod having a diameter of 25 mm and a tip shape of 12.5 mmR was pierced on the surface of the fixed test piece at a speed of 50 mm / min, and the maximum load (kg) until the rod penetrated was measured.
Similarly, measurement was performed from the inner layer side. The measurement was performed using a tensile tester.
(7) Formability: When forming by water-cooled inflation, formability was comprehensively evaluated according to the following criteria.
○: The bubble was stable and there was no problem.
Δ: It took time for the bubbles to stabilize.
X: Could not be molded.

4). Preparation of Resin Used (1) Component (B): Ethylene / α-Olefin Copolymer (PE-1) to (PE-2) obtained in the following Production Examples 1-2 were used. The physical properties are shown in Table 1.

(Production Example 1)
(1-1) Catalyst preparation The catalyst was prepared by the method described in JP-T-7-508545. That is, 2.0 mol of complex dimethylsilylene bis (4,5,6,7-tetrahydroindenyl) hafnium dimethyl is added in an equimolar amount to the above complex, and diluted to 10 liters with toluene. A catalyst solution was prepared.
(1-2) Polymerization A stirred autoclave type continuous reactor having an internal volume of 1.5 liters was maintained at a pressure of 130 MPa, and a mixture of ethylene and 1-hexene was 55% by weight of 1-hexene. The raw material gas was continuously supplied at a rate of 40 kg / hour. The catalyst solution was continuously supplied, and the supply amount was adjusted so that the polymerization temperature was maintained at 148 ° C. The polymer production per hour was about 2.1 kg. After completion of the reaction, an ethylene / 1-hexene copolymer having a 1-hexene content of 12% by weight, MFR = 2.2 g / 10 minutes, density = 0.905 g / cm ³ , and Mw / Mn = 2.3 ( PE-1) was obtained.

(Production Example 2)
Catalyst preparation and polymerization were carried out in the same manner as in Production Example 1 except that the composition of 1-hexene at the time of polymerization was changed to 58% by weight and the polymerization temperature was changed to 143 ° C. The polymer production per hour was about 2.1 kg. After completion of the reaction, an ethylene / 1-hexene copolymer (1-hexene content = 14% by weight, MFR = 2.2 g / 10 minutes, density = 0.901 g / cm ³ , Mw / Mn = 2.3) PE-2) was obtained.

(Production Example 3)
Catalyst preparation and polymerization were carried out in the same manner as in Production Example 1, except that the composition of 1-hexene at the time of polymerization was changed to 50% by weight and the polymerization temperature was changed to 156 ° C. The polymer production per hour was about 2.6 kg. After completion of the reaction, an ethylene / 1-hexene copolymer having 1-hexene content = 11 wt%, MFR = 2.2 g / 10 min, density = 0.910 g / cm ³ , and Mw / Mn = 2.3 ( PE-4) was obtained.

(Production Example 4)
Catalyst preparation and polymerization were carried out in the same manner as in Production Example 1 except that the composition of 1-hexene at the time of polymerization was changed to 62% by weight and the polymerization temperature was changed to 140 ° C. The amount of polymer produced per hour was about 2.0 kg. After completion of the reaction, an ethylene / 1-hexene copolymer having 1-hexene content = 15 wt%, MFR = 2.2 g / 10 min, density = 0.898 g / cm ³ , and Mw / Mn = 2.3 ( PE-5) was obtained.

(2) Component (C): High-density polyethylene As a high-density polyethylene (HD), a commercially available product “Novatech HJ562” (MFR: 7 g / 10 min, density: 0.964 g / cm ³ , supplementary) The outer melting end temperature (Tm _c ): 136 ° C.) was used.

(Example 1)
As the component (A) in the outer layer, high pressure method low density polyethylene (HP-LD) (extrapolated end temperature (Tm _a ) of melting peak: 118 ° C., MFR: 4 g / 10 minutes, Vicat softening temperature (Ta): 106 ° C. , Melt tension: 1.03 g) was used.
Moreover, the composition which mix | blended 5 weight% of component (C) with respect to 95 weight% of (PE-1) was used for the intermediate | middle layer.
Furthermore, the composition which mix | blended 10 weight% of high density polyethylene (HD) of a component (C) with respect to 90 weight% of (PE-1) was used for the inner layer.
The resin material of each layer is set in a three-layer, three-layer water-cooled inflation molding machine manufactured by Plako, and water-cooled inflation molding is performed under the above conditions. The thickness of the outer layer and inner layer is 50 μm, the thickness of the intermediate layer is 150 μm, the folding diameter is 180 mm A tubular laminate was formed. Table 2 shows the evaluation results of the obtained laminate.

(Example 2)
A laminate was obtained in the same manner as in Example 1 except that a composition in which 7.5% by weight of component (C) was blended with respect to 92.5% by weight of (PE-1) was used for the intermediate layer. The evaluation results are shown in Table 2.

(Example 3)
Ethylene 1-butene copolymer (L-LD) produced using Ziegler type catalyst as component (A) in the outer layer (density: 0.921 g / cm ³ , MFR: 1.1 g / 10 min, Vicat) A laminate was obtained in the same manner as in Example 1 except that softening temperature: 102 ° C., melt tension: 0.75 g) (PE-3) was used. The evaluation results are shown in Table 2.

Example 4
In the intermediate layer, a composition in which 10% by weight of component (C) was blended with 90% by weight of (PE-1) and 15% of component (C) was blended with 85% by weight of (PE-1) in the inner layer. A laminate was obtained in the same manner as in Example 1 except that the composition containing wt% was used. The evaluation results are shown in Table 2.

(Example 5)
A laminate was obtained in the same manner as in Example 4 except that the intermediate layer was composed of 95% by weight of (PE-1) and 5% by weight of component (C). The evaluation results are shown in Table 2.

(Example 6)
A composition in which 50% by weight of (PE-5) and 5% by weight of component (C) were blended with 45% by weight of (PE-4) in the intermediate layer and 90% by weight of (PE-4) in the inner layer. On the other hand, a laminate was obtained in the same manner as in Example 1 except that a composition containing 10% by weight of the component (C) was used. The evaluation results are shown in Table 2.

(Comparative Example 1)
A laminate was obtained in the same manner as in Example 1 except that a composition in which 2.5% by weight of the component (C) was blended with respect to 97.5% by weight of (PE-2) was used for the intermediate layer. The evaluation results are shown in Table 3.
This has good flexibility (after sterilization), drop bag strength (after sterilization) and adhesion to the seal bar, but is inferior in heat resistance and transparency (after sterilization).

(Comparative Example 2)
Except for using high-pressure low-density polyethylene (HP-LD) (extrapolated end temperature of melting peak (Tm _a ): 118 ° C., MFR: 4 g / 10 min, Vicat softening temperature (Ta): 106 ° C.) for the inner layer Obtained a laminate in the same manner as in Example 1. The evaluation results are shown in Table 3.
This has good heat resistance, bag drop strength (after sterilization treatment) and adhesion to the seal bar, but is inferior in transparency (after sterilization treatment) and flexibility (after sterilization treatment).

(Comparative Example 3)
A laminate was obtained in the same manner as in Example 1 except that a resin composition in which 90% by weight of (PE-1) and 10% by weight (HD) were used in the intermediate layer was used. The evaluation results are shown in Table 3.
This material has good heat resistance, transparency (after sterilization treatment), and adhesion to the seal bar, but is inferior in flexibility (after sterilization treatment) and bag drop strength (after sterilization treatment).

(Comparative Example 4)
A laminate was obtained using a resin composition in which 90% by weight of (PE-1) and 10% by weight of (HD) were blended in all three layers. The evaluation results are shown in Table 3.
This product has good heat resistance, transparency (after sterilization treatment), flexibility (after sterilization treatment), and bag drop strength (after sterilization treatment), but poor adhesion to the seal bar.

(Comparative Example 5)
High pressure method low density polyethylene (HP-LD) (melting peak extrapolation end temperature (Tm _a ): 118 ° C., MFR: 4 g / 10 min, Vicat softening temperature (Ta): 106 ° C.) is used for all three layers. A laminate was obtained. The evaluation results are shown in Table 3.
This material has good adhesion to the seal bar, but is inferior in heat resistance, transparency (after sterilization treatment), flexibility (after sterilization treatment), bag drop strength (after sterilization treatment), and piercing strength.

(Comparative Example 6)
In the intermediate layer, a composition containing 5.0% by weight of component (C) with respect to 95.0% by weight of (PE-3) was used. A laminate was obtained in the same manner as in Example 1 except that a composition containing 10% by weight of C) was used. The evaluation results are shown in Table 3.
This product has good heat resistance, flexibility (after sterilization treatment), and good adhesion to the seal bar, but is inferior in piercing strength, transparency (after sterilization treatment) and bag drop strength (after sterilization treatment).

(Comparative Example 7)
In Example 1, the resin composition materials of the outer layer and the intermediate layer were replaced, and a laminate was obtained in the same manner as in Example 1. The evaluation results are shown in Table 3.
This product has good heat resistance, but is inferior in flexibility (after sterilization treatment), drop bag strength (after sterilization treatment), adhesion to a seal bar, and puncture strength.

  The laminate of the present invention not only has good hygiene, but also has excellent flexibility, transparency and puncture strength after 115 ° C. sterilization treatment, and heat resistance, bag drop strength that causes problems during transportation and handling Is excellent. Therefore, it can also be used in the medical field such as medical bags, particularly infusion bags, and the food packaging field for retorts that require heat resistance.

Claims (6)

A laminate including at least an outer layer, an intermediate layer, and an inner layer in this order,
The outer layer is formed of a polyolefin resin material (A) having a Vicat softening temperature of 90 to 140 ° C.,
The intermediate layer has a melt flow rate of 85 to 97% by weight with an ethylene / α-olefin copolymer (B) having a melt flow rate of 0.1 to 20 g / 10 min and a density of 0.880 to 0.930 g / cm ^3. An ethylene / α-olefin copolymer composition (a) comprising ³ to 15% by weight of high density polyethylene (C) having a rate of 0.1 to 20 g / 10 min and a density of 0.940 to 0.980 g / cm ³ )
The inner layer has an melt flow rate of 80 to 95% by weight of an ethylene / α-olefin copolymer (B) having a melt flow rate of 0.1 to 20 g / 10 min and a density of 0.880 to 0.930 g / cm ^3. Is an ethylene / α-olefin copolymer composition (b) comprising 5 to 20% by weight of high density polyethylene (C) having a density of 0.1 to 20 g / 10 min and a density of 0.940 to 0.980 g / cm ^3. Formed,
And the content [HDPEa] (weight%) of the high density polyethylene in the ethylene / α-olefin copolymer composition (a) and the content of the high density polyethylene in the ethylene / α-olefin copolymer composition (b) [HDPEb] (% by weight) satisfies the following formulas (1) and (2).
0 <[HDPEb] − [HDPEa] <15 (1)
10 <[HDPEb] + [HDPEa] <30 (2)   At least one of the intermediate layer or inner layer ethylene / α-olefin copolymer (B) is produced using a metallocene catalyst, and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (Mw / The laminate according to claim 1, wherein Mn) is 1.5 to 4.0.   The polyolefin resin material (A) is a high pressure method low density polyethylene having an extrapolation end temperature of a melting peak of 110 to 125 ° C obtained by differential scanning calorimetry (DSC). 2. The laminate according to 2. Extrapolated melting end temperature (Tm _b ) of melting peak obtained by differential scanning calorimetry (DSC) of ethylene / α-olefin copolymer (B) and extrapolated melting end temperature (Tm) of high-density polyethylene (C) _c ) satisfies following formula (3), The laminated body of any one of Claims 1-3 characterized by the above-mentioned.
15 ≦ (Tm _c −Tm _b ) ≦ 50 (3) The laminate according to any one of claims 1 to 4, wherein the resin composition constituting the outer layer, the intermediate layer, and the inner layer satisfies the following formula (4).
Intermediate layer <Inner layer <Outer layer (4)   A medical bag comprising the laminate according to any one of claims 1 to 5.