JP2001162746A - Laminate and bag for medical care made of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both a laminate, in which hygienic properties are high, flexibility, transparency, resistance to pinhole and heat sealability are excellent and also heat resistance and falling bag strength are good, and a bag for medical care which is made of the laminate and houses chemicals and blood or the like. SOLUTION: In the laminate and the bag for medical care, in which the laminate is used, the outer layer is formed of a polyolefin-based resin material having specific Vicat softening temperature and the inner layer is formed of polyethylens-based resin material incorporating an ethylenes.α-olefin copolymer as a main component. The ethylene.α-olefin copolymer contains a low crystalline component and a high crystalline component. In the low crystalline component, (1) the lower crystalline component in a TREF elution curve has a specific peak temperature, strength and area and (2) MFR is 0.1-20 g/10 minutes and (3) Vicat softening temperature is 65-125 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to hygiene, flexibility,
The present invention relates to a laminate excellent in transparency, heat resistance, dropping strength, suitability for heat sealing, and the like, and a medical bag containing a liquid medicine, blood, and the like made of the laminate.

[0002]

2. Description of the Related Art At present, as a medical container, a hard container made of glass, polyethylene, polypropylene or the like and a soft bag made of polyvinyl chloride containing a plasticizer are known. However, in the case of the former rigid container, air must be introduced using a ventilation needle or an infusion set with a ventilation hole when the content liquid is dropped. Furthermore, there is a possibility that the content liquid may be contaminated. Further, a rigid container made of polyethylene or polypropylene has a problem that transparency is insufficient and the amount of the content liquid is difficult to see.

On the other hand, the latter flexible bag does not require the introduction of air as in the above-described hard container, and has safety and convenience in transportation such as the bag itself being squeezed by the atmospheric pressure as the contents are dropped. There are advantages such as high. However, there is a problem because the plasticizer and residual monomer contained in polyvinyl chloride are precipitated as fine particles in the content liquid. Therefore, an alternative material is desired.

On the other hand, a medical bag using a polymer such as an ethylene-vinyl acetate copolymer or an elastomer for an intermediate layer has been proposed from the viewpoint of flexibility, transparency, hygiene and the like (Japanese Patent Application Laid-Open (JP-A) No. Sho. 58-165866), however, these polymers used in the intermediate layer have poor heat resistance, and thus have a drawback in that they have poor appearance such as wrinkles during sterilization or reduced transparency after sterilization. Further, there may be a problem that a pinhole is generated at the time of transportation, the bag is broken when the bag is dropped, and the like.

On the other hand, JP-A-6-171039 discloses a laminate in which the outer layer is a polypropylene resin and the intermediate layer is a conventional linear ethylene / α-olefin copolymer.
Japanese Patent Application Laid-Open No. Hei 9-141793 proposes laminates each having an ethylene / α-olefin copolymer having a melting point of one produced by using a polypropylene resin for the outer layer and a metallocene catalyst for the intermediate layer. I have. However, medical bags made of these laminates do not have high levels of transparency, strength, flexibility and heat resistance in a well-balanced manner.

Further, from the viewpoint of heat resistance, since a heat-resistant material is disposed in the inner layer, there is almost no difference in melting point between the outer layer and the inner layer. Is attached to the seal bar), and the work efficiency is reduced.

[0007] Therefore, there is no problem as described above, that is, not only good hygiene, but also excellent flexibility and transparency, high heat resistance, and further, the strength of bag breaking when dropped. A good medical bag excellent in heat sealability has not been achieved with a conventional multilayer medical bag.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a laminate having high hygiene, excellent flexibility and transparency, excellent pinhole resistance, excellent heat sealing suitability, and excellent heat resistance and bag drop strength. An object of the present invention is to provide a medical bag that stores a body and a medical solution, blood, and the like made of the body.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that a polyolefin resin material having a specific Vicat softening point is used for the outer layer, and a specific melt flow rate (melt flow rate: hereinafter) is used for the inner layer. "MFR"), the Vicat softening point, and the finding that the object of the above invention can be achieved by using an ethylene / α-olefin copolymer comprising a low crystalline component and a high crystalline component having specific properties. As a result, the present invention has been completed.

That is, the present invention provides a laminate comprising at least an outer layer and an inner layer in this order, wherein the outer layer is formed of a polyolefin resin material satisfying the following physical properties (A1), and the inner layer is formed of a low crystalline component. A copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms and a polycrystalline resin having the following physical properties (B1) to (B5): A laminate comprising a material. (A1) Vicat softening temperature Ta; Tb <Ta ≦ 140 ° C. (B1) Temperature rise elution fractionation (TRE) of the copolymer component
F) In the elution curve, the elution peak temperature of the low crystalline component is in the range of 45 to 85 ° C. (B2) Temperature rise elution fractionation (TRE) of the copolymer component
F) In the elution curve, the peak height of the low crystalline component is H
When the height of the minimum valley between the peak of the low crystal component and the peak of the high crystal component is M, the value of H / M is 9 or more. (B3) Elevated temperature elution fractionation (TRE) of the copolymer component
F) The ratio of the area of the low crystalline component below the elution peak temperature to the entire area of the elution curve is 35% or more. (B4) The copolymer component has an MFR of 0.1 to 20 g /
10 minutes. (B5) The Vicat softening temperature Tb is in the range of 65 to 125 ° C.

[0011] The present invention also provides a method of the present invention, wherein the outer layer has a polypropylene resin satisfying the above-mentioned physical properties.
SC) The high-pressure method low-density polyethylene having an extrapolation melting end temperature of 110 ° C. or higher, ethylene having a density of 0.910 g / cm ³ or higher, and ^{3 to} 18 carbon atoms.
The laminate is characterized in that the laminate comprises a resin material selected from the group consisting of a copolymer with an α-olefin.

The present invention also provides a medical bag comprising any one of the above-mentioned laminates.

[0013]

Embodiments of the present invention will be described below. I. Inner Layer The inner layer of the laminate of the present invention is a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms (hereinafter referred to as “ethylene · α-
Olefin copolymer "or simply" copolymer ") as the main component, and has physical properties (B1) to (B5).

1. Physical properties of copolymer of ethylene and α-olefin having 3 to 18 carbon atoms (1) Physical properties (B1): peak temperature of elution curve by temperature-rise elution fractionation The copolymer used for the inner layer of the laminate of the present invention is: An elution curve having a low crystalline component having an elution peak temperature of 45 to 85 ° C, preferably 48 to 80 ° C, is used in the elution curve obtained by the temperature rise elution fractionation (TREF). If the peak temperature is higher than the above range, flexibility, transparency, pinhole resistance, and film strength are undesirably deteriorated. Also,
If the peak temperature is lower than the above range, heat resistance is undesirably deteriorated.

(2) Physical properties (B2): H in TREF
/ M The copolymer used for the inner layer of the laminate of the present invention has a low crystal component having a peak height of H in an elution curve obtained by temperature rise elution fractionation (TREF), and has a low crystal component and a high crystal component. Where M is the height of the minimum valley of H / M
Of 9 or more are used. Here, the minimum valley is a portion where the height is minimum among the valleys formed between the elution peak of the low crystalline component and the elution peak of the high crystalline component. If the value of H / M is less than 9, transparency, pinhole resistance and film strength are undesirably reduced. 1 and 2 show H and M.

(3) Physical Properties (B3): Area Ratio in TREF The copolymer used for the inner layer of the laminate of the present invention has a low crystalline component with respect to the entire area of an elution curve obtained by temperature rise elution fractionation (TREF). Those having an area ratio of 35% or more below the peak temperature are used. If the above value is less than 35%, the flexibility, transparency, pinhole resistance and film strength are undesirably reduced. 1 and 2
The area below the elution peak temperature of the low crystalline component is shown by oblique lines.

Here, the temperature rise elution fractionation (TREF: T
emperature Rising Elution
Fraction means that once the polymer is completely dissolved, it is cooled, a thin polymer layer is formed on the surface of the inert carrier, and then the temperature is continuously or gradually increased.
This is a method in which the eluted component (polymer) is collected, its concentration is continuously detected, and the amount of the eluted component and the elution temperature are determined.

A graph drawn by the elution fraction and the elution temperature is an elution curve, from which the composition distribution (molecular weight and crystallinity distribution) of the polymer can be measured. For details of the method and apparatus for measuring the temperature rise elution fractionation (TREF), see Journal of Appl.
ied Polymer Science, Vol. 26,
Nos. 4217-4231 (1981).

The shape of the elution curve obtained by TREF depends on the molecular weight and the distribution of crystallinity of the polymer.
For example, there are a curve having one peak, a curve having two peaks, a curve having three peaks, and the like. Further, in the curve having two peaks, the peak having a higher elution temperature is more eluted than the peak having a lower elution temperature. In some cases, the ratio is large (the height of the peak is high), and the peak with a high elution temperature has a smaller fraction (lower the height of the peak) than the peak with a lower elution temperature.

Since the copolymer used in the present invention contains at least a low crystalline component and a high crystalline component, it has at least two peaks (elution peaks) of the elution curve. In the case of two peaks, the peak with the higher elution temperature is the elution peak of the high crystalline component, and the one with the lower elution temperature is the elution peak of the low crystalline component.

The copolymer is not particularly limited as long as it has at least two elution peaks. For example, the copolymer may have three or more elution peaks. In that case,
The peak having the highest elution temperature among the elution peaks is the elution peak of the high crystalline component, and among the peaks having lower elution temperatures than the elution peak of the high crystalline component, the peak having the highest peak height is the elution of the low crystalline component. It is a peak. Therefore, in the temperature range lower than the elution temperature of the elution peak of the low crystalline component,
A peak having a lower peak height than the elution peak of the low crystalline component may be present, and a peak from the elution peak of the low crystalline component may be located between the elution peak of the high crystalline component and the elution peak of the low crystalline component. There may be low peaks. Further, in both the temperature region lower than the elution temperature of the elution peak of the low crystalline component and the temperature region between the elution peak of the high crystalline component and the elution peak of the low crystalline component, the peak height is higher than the elution peak of the low crystalline component. Lower peaks may be present.

These will be described specifically with reference to the drawings. FIG. 1 shows an elution curve for two peaks, and FIG. 2 shows an elution curve for three peaks. FIG. 2A shows a temperature range lower than the elution temperature of the elution peak of the low-crystalline component,
FIG. 2B shows the case where a peak having a lower peak height than the elution peak of the low crystalline component is present. This represents a case where a peak having a lower peak height than the elution peak of the component exists. In the figure, 1 is an elution peak of a high crystalline component, and 2 is an elution peak of a low crystalline component.

(4) Physical Properties (B4): Melt Flow Rate The copolymer used in the present invention has a melt flow rate (melt flow rate: hereinafter, abbreviated as “MFR”) of 0.1.
-20 g / 10 min, preferably 0.1-15 g / 10 min
Min, more preferably 0.1 to 10 g / 10 min. The MFR here is JIS-K7210
(190 ° C., 2.16 kg load). If the MFR exceeds the above range, the heat resistance and the film strength decrease, and the film formation of the film becomes unstable. On the other hand, if the MFR is less than the above range, the resin pressure becomes high, and the extrudability decreases, which is not preferable.

(5) Physical properties (B5): Vicat softening temperature The copolymer used for the inner layer of the laminate of the present invention has a Vicat softening temperature Tb of 65 to 125 ° C., preferably 70 to 1
The one at 20 ° C. is used. If the Vicat softening temperature Tb exceeds the above range, the flexibility, transparency, pinhole resistance, and film strength are undesirably deteriorated. Also,
If the peak temperature is lower than the above range, heat resistance is undesirably deteriorated.

(6) Density The density of the copolymer is not particularly limited, but is preferably 0.880 to 0.930 g / cm ³ , and more preferably 0.885 to 0.925 g / cm ³ . When the density is in this range, flexibility, pinhole resistance, and film strength are good, so that it is preferable. In addition, the density here is a value measured based on JIS-K7112.

2. Ethylene / α-olefin copolymer The copolymer of the present invention that satisfies the above properties (B1) to (B5) is an ethylene / α-olefin copolymer that satisfies the properties (B1) to (B5) alone (ie, The above-mentioned ethylene / α-olefin copolymer having a low crystalline component and a high crystalline component simultaneously) may be used alone, or two or more ethylene / α-olefin copolymers may be mixed to form The physical properties (B1) to (B5) may be satisfied.

When an ethylene / α-olefin copolymer which satisfies the above physical properties (B1) to (B5) alone is used, the copolymer preferably contains at least 80 mol% of ethylene and α-olefin which is a comonomer. 20 mol% or less. For example, as a known method for controlling the molecular weight and the distribution of crystallinity, a polymer having desired physical properties can be obtained by appropriately adopting a method of adjusting the polymerization temperature and the amount of comonomer.

The ethylene / α-olefin copolymer has a structural unit derived from ethylene as a main component, and the α-olefin used as a comonomer is a 1-olefin having 3 to 18 carbon atoms. . Specific examples of the 1-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 1-olefin.
Heptene, 4-methyl-pentene-1, 4-methyl-hexene-1, 4,4-dimethylpentene-1 and the like can be mentioned. Specific examples of such an ethylene / α-olefin copolymer include an ethylene / 1-butene copolymer,
Examples thereof include an ethylene / 1-hexene copolymer and an ethylene / 1-octene copolymer.

The α-olefin used as a comonomer is not limited to one kind, and a multi-component copolymer using two or more kinds such as a terpolymer is also preferable. Specific examples include an ethylene / propylene / 1-butene terpolymer.

When two or more ethylene / α-olefin copolymers are mixed to satisfy the above physical properties (B1) to (B5), the elution peak temperature in the temperature rise elution fractionation (TREF) elution curve Is an ethylene / α-olefin copolymer having 45 to 85 ° C. (low crystalline component: component A);
It is preferable to mix an ethylene / α-olefin copolymer having a higher elution peak temperature than that (highly crystalline component: component B) and use it as a resin mixture.

With respect to the ethylene / α-olefin copolymer used as component A (low crystalline component) and component B (high crystalline component) in the resin mixture, the ratio of ethylene to comonomer and the type of comonomer are as follows. This is the same as the case of the ethylene / α-olefin copolymer that satisfies the above-mentioned properties (B1) to (B5) alone.

The MFR of component A is preferably 0.1 to 2
0 g / 10 min, more preferably 0.1 to 15 g / 10 min
And the density is preferably 0.870 to 0.930 g /
cm ³, More preferably 0.880 to 0.925 g / c.
m³It is. If the MFR is within this range, the film strength
This has the advantage of excellent film formation stability and density.
Within the range, blocking resistance, heat resistance, flexibility,
It has the advantage of excellent pinhole properties. Such components
Specific examples of A include ethylene / 1-hexene copolymer
And ethylene / 1-octene copolymer.

The MFR of component B is preferably from 0.1 to 50.
g / 10 min, more preferably 0.5 to 40 g / 10 min, and the density is preferably 0.930 to 0.970 g / c.
m ³ , more preferably 0.935 to 0.968 g / cm
³ . When the MFR is in this range, the film forming stability is good, and when the density is in this range, the heat resistance is good.
Specific examples of the component B include ethylene homopolymer,
Ethylene / 1-butene copolymer and the like.

The mixing ratio of the components A and B in the resin mixture is not particularly limited, but is based on the total amount of the resin mixture.
98 to 45% by weight of component A, more preferably 95 to 50%
% By weight, 2 to 55% by weight of component B, more preferably 5 to
It is preferable to contain 50% by weight.

3. Method for Producing Ethylene / α-Olefin Copolymer Ethylene / α-olefin copolymer (including each component such as component A and component B when used alone or as a resin mixture) There are no particular restrictions on the polymerization method and catalyst as long as a compound satisfying the above physical properties can be produced.

For example, as the catalyst, a Ziegler type catalyst (based on a combination of a supported or unsupported halogen-containing titanium compound and an organoaluminum compound), a Phillips type catalyst (based on supported chromium oxide (Cr ⁶⁺ )), Kaminsky Type catalysts (based on a combination of a supported or unsupported metallocene compound and an organoaluminum compound, particularly an alumoxane), and the like.

The metallocene-based catalysts are specifically described in JP-A-58-19309, JP-A-59-95292, JP-A-60-35005, JP-A-60-35006, and JP-A-60-35006. No. 35007, JP-A-60-35008,
JP-A-60-35009, JP-A-61-130314
JP-A-3-1630088, European Patent Application Publication No. 420,436, U.S. Pat.
055,438, and International Publication WO 91
/ 04257 and metallocene catalysts or metallocene / alumoxane catalysts, or a metallocene compound as disclosed in, for example, International Publication WO92 / 07123 and the like, and reacted with the metallocene compound And a catalyst comprising a compound that becomes a stable ion.

The ethylene / α-olefin copolymer having an elution peak on the high temperature side (highly crystalline component: component B) used in the case of forming a resin mixture is not limited in terms of catalyst as long as a copolymer satisfying the above conditions is obtained. The polymer of any of the catalysts can exert the effects of the present invention.

On the other hand, an ethylene / α-olefin copolymer having an elution peak on the low temperature side (low crystalline component: component A)
It is preferable to use a catalyst having a relatively narrow composition distribution that does not contain a high crystalline component and a low crystalline component. Therefore, it is particularly preferable to use a Kaminski catalyst, that is, a metallocene catalyst using a metallocene compound containing a tetravalent transition metal.

The metallocene compound used for the Kaminsky type catalyst includes, for example, an organic transition metal of a Group 4 to 6 transition metal compound such as Zr, Ti, and Hf, particularly a Group 4 transition metal compound and cyclopentadiene or a cyclopentadiene derivative. Compounds can be used.

As the cyclopentadiene derivative, an alkyl substituent such as pentamethylcyclopentadiene, or a compound having two or more substituents bonded to form a saturated or unsaturated cyclic substituent can be used. Examples include indene, fluorene, azulene, and partially hydrogenated products thereof.

Further, a compound in which a plurality of cyclopentadiene are linked by an alkylene group, a silylene group or the like can be used. As the co-catalyst, a compound capable of reacting with an organoaluminum or metallocene catalyst to form stable ions can be used, and alumoxane is generally used.

As a polymerization method, a slurry method in the presence of these catalysts, a gas-phase fluidized-bed method (for example,
23011), a solution method, or a high-pressure bulk polymerization method in which the pressure is 200 kg / cm ² or more and the polymerization temperature is 100 ° C. or more.

With respect to a specific method for producing the ethylene / α-olefin copolymer in the present invention, when an ethylene / α-olefin copolymer satisfying the above physical properties (B1) to (B5) alone is used, it is usually used. A method of producing the copolymer in one reaction vessel is employed. Further, as the ethylene / α-olefin copolymer, the component A and the component B
When a resin mixture of two or more components such as is used, a method of producing each component in one reaction tank, connecting two or more reaction tanks, polymerizing each component in each tank, and continuously A method for producing a resin composition that satisfies the above physical properties (B1) to (B5), by separately polymerizing each component, and then blending each component according to a method similar to a usual method for producing a resin composition, Various methods such as a method of producing a resin mixture satisfying the above physical properties (B1) to (B5) can be adopted.

More specifically, the component A (low crystal component) and the component B (high crystal component) may be dry-blended in advance, and the resulting blend may be directly charged into a hopper of a molding machine. Further, the blend can be melted and kneaded using an extruder, a Brabender blast graph, a Banbury mixer, a kneader blender, or the like, and formed into pellets by a commonly used method to produce a film or sheet.

4. Auxiliary additive component The polyethylene resin material constituting the inner layer may be composed of only the above-mentioned ethylene / α-olefin copolymer as a main component, but in addition, a range that does not significantly impair the effects of the present invention. In the above, an auxiliary additive component generally used for a resin composition may be blended as required.

Examples of such auxiliary additives include an antioxidant, an antiblocking agent, a neutralizing agent, a heat stabilizer and the like. As the antioxidant, phenol-based and phosphorus-based antioxidants are preferable.

When a resin mixture of a component A having an elution peak on the low-temperature side and a component B having an elution peak on the high-temperature side is used as a main component, the two components are mixed before, during or after mixing. The above-mentioned auxiliary additive component can be blended with either one or both.

The ethylene / α-olefin copolymer alone, or the total weight of the resin mixture of the component A having an elution peak on the low temperature side and the component B having an elution peak on the high temperature side may be used in the present invention. In order to improve the interlayer adhesion within the range where the effect is not impaired, the polypropylene resin used for the outer layer, high-pressure low-density polyethylene, ethylene and carbon number 3
To 40 to 18% by weight of a resin material selected from the group consisting of copolymers with α-olefins of No.

In order to provide flexibility, a crystalline ethylene / α-olefin copolymer and / or EBR, E
Ethylene / α-olefin elastomer such as PR, SE
A rubber-based compound such as a styrene-based elastomer such as BS or HSBC may be blended in an amount of 3 to 75% by weight.

II. Outer layer 1. Physical Properties of Polyolefin Resin (1) Vicat Softening Temperature The polyolefin resin material of the outer layer of the laminate of the present invention is:
Those whose Vicat softening temperature Ta satisfies Tb (Vicat softening temperature of the inner layer) <Ta ≦ 140 ° C. are used. Vicat softening temperature Ta of polyolefin resin material of outer layer
If the temperature is below the Vicat softening temperature Tb of the copolymer of the inner layer, the outer layer side is taken by the seal bar (the outer layer adheres to the upper seal bar) during bag making (the inner layer and the inner layer are heat-sealed by a seal bar). This is not preferable because the working efficiency is reduced. On the other hand, if the Vicat softening temperature Ta of the polyolefin resin material in the outer layer exceeds 140 ° C., the flexibility is insufficient, which is not preferable.

2. Polyolefin resin The polyolefin resin material of the outer layer is not particularly limited as long as its Vicat softening temperature Tb satisfies the above range, but preferably (i) a polypropylene resin,
(Ii) extrapolation melting end temperature of the melting peak obtained by differential scanning calorimetry (DSC) is 110 ° C. or higher; high-pressure low-density polyethylene; and (iii) JIS-K71.
The density measured according to No. 12 is 0.910 g / cm ³
It is preferably a polyolefin resin material selected from the group consisting of the above-mentioned copolymers of ethylene and α-olefins having 3 to 18 carbon atoms.

(I) Polypropylene resin Specific examples of the polypropylene resin (i) include a polypropylene homopolymer and a random copolymer of propylene and ethylene or an α-olefin having 4 or more carbon atoms. be able to. Examples of the α-olefin having 4 or more carbon atoms include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methyl-pentene-1, 4-methyl-hexene-1,4,4. -Dimethylpentene-1 and the like. The proportion of structural units (propylene units) derived from propylene in the random copolymer is preferably at least 80% by weight, particularly preferably at least 85% by weight.

The MFR of the polypropylene resin is not particularly limited, but is preferably 0.1 to 100 g / 10
Min, particularly preferably 0.3 to 80 g / 10 min. The MFR here is JIS-K6758 (230 ° C,
2.16 kg load). MF
When R is within the above range, there is an advantage that film formation is stable.

Specific examples of the polypropylene resin include propylene / ethylene random copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1
-Butene copolymer and the like.

The Ziegler-type or metallocene-based resin is added to the total weight of the polypropylene-based resin in order to impart flexibility and / or to improve the interlayer adhesion within a range that does not impair the effects of the present invention. A crystalline ethylene / α-olefin copolymer polymerized by a catalyst and / or an ethylene / α-olefin elastomer such as EBR or EPR; a styrene-based elastomer such as SEBS or HSBC (hydrogenated styrene block copolymer); A rubber compound can be blended in an amount of 3 to 75% by weight.

In order to improve the interlayer adhesion within the range not impairing the effects of the present invention with respect to the total weight of the polypropylene-based resin, ethylene containing the low-crystalline component and the high-crystalline component used in the inner layer is used. A copolymer with an α-olefin having 3 to 18 carbon atoms can be blended in an amount of 3 to 40% by weight.

(Ii) High-pressure low-density polyethylene High-pressure low-density polyethylene having an extrapolated melting end temperature of 110 ° C. or higher at the melting peak obtained by (ii) differential scanning calorimetry (DSC) has an MFR Although not particularly limited, preferably 0.05 to 100 g / 1
0 minutes, more preferably 0.1 to 80 g / 10 minutes, particularly preferably 0.2 to 70 g / 10 minutes. M here
FR is JIS-K7210 (190 ° C, 2.16 kg
Load). When the MFR value is in this range, there is an advantage that film formation is stable. The density is not particularly limited, but is preferably 0.915
0.940 g / cm ³ , more preferably 0.920 g / cm ³
0.935 g / cm ³ . When the density is in this range, there is an advantage that heat resistance and flexibility are excellent. The density here is a value measured according to JIS-K7112.

Further, in order to impart flexibility and / or to improve the interlayer adhesion, the Ziegler type or low-density polyethylene is added to the total weight of the high-pressure low-density polyethylene, as long as the effect of the present invention is not impaired. A crystalline ethylene / α-olefin copolymer polymerized by a metallocene catalyst and / or an ethylene / α-olefin elastomer such as EBR and EPR, and a styrene elastomer such as SEBS and HSBC (hydrogenated styrene block copolymer) Rubber compound such as 3 to 75% by weight.

In order to improve the interlayer adhesion, the low-crystalline component and the high-crystalline component used in the inner layer are mixed with respect to the total weight of the high-pressure low-density polyethylene, as long as the effect of the present invention is not impaired. A copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms can be blended in an amount of 3 to 40% by weight.

(Iii) ethylene and α having 3 to 18 carbon atoms
-Copolymer with olefin As the copolymer of ethylene as the component (iii) and an α-olefin having 3 to 18 carbon atoms, a copolymer produced using a Ziegler-type catalyst or a metallocene-based catalyst is used. The product (except for the component B used in the inner layer) or the ethylene / α-olefin copolymer usable in the inner layer (single physical property (B1) to
(B5) (including the resin mixture obtained by mixing the component A and the component B to satisfy the above physical properties (B1) to (B5)). Ethylene / α that satisfies the above physical properties (B1) to (B5)
-Among the olefin copolymers, the Vicat softening temperature is higher than the Vicat softening temperature of the copolymer used for the inner layer, 140
C. or lower.

The MFR of the component (iii) is not particularly limited, but is preferably 0.05 to 100 g / 10 min, more preferably 0.1 to 80 g / 10 min, and particularly preferably 0.2 to 70 g / 10 min. It is. The MFR here is
It is a value measured in accordance with JIS-K7210 (190 ° C., 2.16 kg load). When the MFR value is in this range, there is an advantage that film formation is stable. Further, a more preferable range of the density is 0.910 to 0.940 g / c.
m ³ , particularly preferably 0.910 to 0.935 g / cm
³ . If the density is in this range, heat resistance, flexibility,
It has the advantage of excellent transparency. The density here is a value measured according to JIS-K7112.

The above ethylene and α of 3 to 18 carbon atoms
-With respect to the total weight of the copolymer with the olefin, a Ziegler-type or metallocene-based catalyst is used to impart flexibility or / and improve interlayer adhesion within a range that does not impair the effects of the present invention. Polymerized crystalline ethylene / α-olefin copolymer and / or EBR, E
Ethylene / α-olefin elastomer such as PR, SE
A rubber compound such as a styrene elastomer such as BS or HSBC (hydrogenated styrene block copolymer) may be blended in an amount of 3 to 75% by weight.

The above ethylene and α of 3 to 18 carbon atoms
-Ethylene and carbon containing a low-crystalline component and a high-crystalline component used in the inner layer in order to improve the interlayer adhesion, within a range that does not impair the effects of the present invention, based on the total weight of the copolymer with the olefin; The copolymer with the α-olefin of the number 3 to 18 can be blended in an amount of 3 to 40% by weight.

Specific examples of such a copolymer of ethylene and an α-olefin having 3 to 18 carbon atoms include ethylene / 1
-Butene copolymer, ethylene / 1-hexene copolymer,
Examples thereof include an ethylene / 1-octene copolymer.

III. Laminate and medical bag The laminate of the present invention may include at least the outer layer and the inner layer in this order, and in addition to the outer layer and the inner layer, various layers generally used in the laminate. May be provided as needed, and thus a three-layer, four-layer, or more laminate may be used. Specific examples of various commonly used layers include polyolefin resin materials,
Adhesive resin, rubber, polyamide, polyester, EVOH
And the like.

As a method for obtaining a laminate, a water-cooled or air-cooled coextrusion inflation method, a coextrusion T-die method, a dry lamination method, an extrusion lamination method, or the like can be employed. The laminate is usually in the form of a tube or a sheet.These are stacked and heat-sealed to form a bag having a predetermined shape and dimensions, and an injection port is attached to form a target medical bag. Obtainable.

The thickness of the laminate is preferably 0.1 to 0.5.
7 mm, more preferably 0.15 to 0.6 mm.
If it is less than 0.1 mm, the feeling of mass is impaired. On the other hand, 0.7
If it exceeds mm, the flexibility tends to be insufficient. The thickness ratio of each layer is not particularly limited. However, in order to sufficiently impart flexibility to the laminate, the thickness of the inner layer should be 50% or more, preferably 55% or more, more preferably 9% or more of the total thickness of the laminate.
The thickness is preferably 8 to 60%, and the thickness of the outer layer is preferably 1 to 50%. If the thickness ratio of the outer layer to the entire laminate exceeds the above range, the flexibility of the laminate tends to be insufficient. If the thickness of each of the outer layers is less than 0.01 mm, the outer layers tend to adhere to the upper seal bar.

The medical bag of the present invention comprises the above-mentioned laminate. Specific uses of the medical bag include an infusion bag, a container for injecting, discharging, and preserving a body fluid or a drug solution, a peritoneal dialysis bag, an artificial dialysis bag, and the like. Further, since the laminate of the present invention is excellent in transparency, flexibility, heat resistance, and dropping strength, it can be suitably used as a food packaging bag (for example, for semi-retort, retort, etc.).

[0070]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. In addition, the measurement of various physical properties of the resin and the evaluation of the laminated body in these Examples and Comparative Examples were performed by the following methods.

1. Method for Measuring Physical Properties of Resin (1) MFR: For MFR of ethylene / α-olefin copolymer and high-pressure low-density polyethylene, JIS
It measured based on -K7210 (190 degreeC, 2.16 kg load). The MFR of the polypropylene resin was measured according to JIS-K6758 (230 ° C, 2.16 kg load).

(2) Measurement of elution curve obtained by TREF: Measurement of the elution curve by TREF in the present invention was carried out as follows. The measurement was carried out using a cloth separation apparatus (CFC T150A, manufactured by Mitsubishi Chemical Corporation) as a measurement apparatus according to the measurement method in the attached operation manual. The cross separation apparatus includes a temperature-rise elution separation (TREF) mechanism for separating a sample using a difference in dissolution temperature,
A size exclusion chromatograph (Size Exclusion Chron) for further fractionating the fractionated fraction by molecular size
(SEC) is an apparatus connected online with the SEC (romatography: SEC).

First, the sample to be measured (ethylene · α
-Olefin copolymer) using a solvent (o-dichlorobenzene) to give a concentration of 4 mg / ml.
It was melted at ℃ and injected into a sample loop in the measuring device. The following measurements were performed automatically according to the set conditions.

The sample solution held in the sample loop is separated using a TREF column (internal diameter of 4 m filled with glass beads as an inert carrier) by utilizing the difference in dissolution temperature.
m, 150mm length stainless steel column attached to the device)
Was injected 0.4 ml. The sample was cooled at a rate of 1 ° C./min from 140 ° C. to 0 ° C. and coated on the inert carrier. At this time, from the high crystal component (the one that is easy to crystallize) to the low crystal component (the one that hardly crystallizes)
The polymer layer is formed on the surface of the inert carrier in this order. TR
After holding the EF column at 0 ° C. for an additional 30 minutes, 2 ml of the component dissolved at a temperature of 0 ° C. was added at a flow rate of 1 ml / min.
From REF column to SEC column (Showa Denko KK,
AD80M · S, 3 tubes). While fractionation by molecular size was being performed by SEC, the temperature of the TREF column was raised to the next elution temperature (5 ° C.) and maintained at that temperature for about 30 minutes. The measurement of each elution section by SEC was performed at intervals of 39 minutes. The following temperature is used as the elution temperature,
The temperature was raised stepwise.

Elution temperature (° C.): 0, 5, 10, 15, 2
0, 25, 30, 35, 40, 45, 49, 52, 5
5,58,61,64,67,70,73,76,7
9,82,85,88,91,94,97,100,1
02,120,140 ° C.

With respect to the solution separated by the molecular size in the SEC column, the absorbance in proportion to the concentration of the polymer was measured with an infrared spectrophotometer attached to the apparatus (wavelength 3.42 μm).
m, detection by stretching vibration of methylene) to obtain chromatograms for each elution temperature category. Using built-in data processing software,
A baseline of the chromatogram of each elution temperature section obtained by the above measurement was drawn and subjected to arithmetic processing. The area of each chromatogram was integrated and an integrated elution curve was calculated. Also,
This integrated elution curve was differentiated by temperature to calculate a differential elution curve. The plot of the calculation results was output to a printer. In the plot of the output differential elution curve, the elution temperature is plotted on the horizontal axis.
The difference was 89.3 mm per 0 ° C. and the differential amount on the vertical axis (elution fraction: the total integrated elution amount was standardized to 1.0, and the change at 1 ° C. was defined as the differential amount) at 76.5 mm per 0.1. .

Next, from this differential elution curve, the peak at the highest temperature was taken as the elution peak of the high crystal component, and the maximum peak at a lower temperature side was taken as the elution peak of the low crystal component. Further, the value of H / M was calculated, where H is the peak height on the low temperature side, and M is the height of the minimum valley between the elution peak of the low crystalline component and the elution peak of the high crystalline component. Next, the area ratio of the low crystalline component at or below the elution peak temperature to the total area was determined from the integrated elution curve.

(3) Density: Measured according to JIS-K7112.

(4) Extrapolation melting temperature of melting peak by DSC: Approximately 5 mg of a sample was weighed from a 100 μm film formed by a hot press, and was weighed into an RDC 220 DSC device manufactured by Seiko Denshi Kogyo KK. Set
After the temperature was raised to 170 ° C and maintained at that temperature for 5 minutes, it was cooled to -10 ° C at a rate of temperature decrease of 10 ° C / min. Next, -1
After holding at 0 ° C. for 1 minute, the temperature was raised at a rate of 10 ° C./min.
The temperature was raised to 10 ° C and the DSC measurement was performed.
DSC curves up to ° C were obtained. In accordance with JIS-K7121, the temperature at the intersection of a line obtained by extending the base line on the high-temperature side of the DSC curve to the low-temperature side and the tangent drawn at the point where the gradient becomes maximum on the high-temperature side curve of the melting peak is extrapolated. End temperature.

(5) Vicat softening temperature: JIS-K72
It measured according to 06-1974.

2. Evaluation method of laminate (1) Adhesion to outer layer and upper seal bar: heat seal temperature: 160 ° C., seal pressure: 2 kg / cm ² , seal time: 3 seconds, seal bar width: 10 mm heat seal conditions: The inner surfaces of the laminate are heat-sealed with a seal bar,
When the seal bar was raised, the case where the outer surface of the laminate adhered to the upper seal bar was evaluated as x, and the case where it did not adhere was evaluated as ○. In the case where the outer surface of the laminate does not adhere to the upper seal bar, the optimum heat sealing temperature is widened, so that not only the work efficiency is good but also troubles such as poor heat sealing are lessened, so that the laminate is excellent.

(2) Heat resistance at 115 ° C .: tube (cylinder)
The laminated body (having two layers) is
It was cut into a size of 90 mm × 190 mm and heat-sealed on three sides to form a bag. Then, 60 ml of distilled water is placed therein.
0 ml was filled, and the other side was heat-sealed and sealed.
The sample bag thus obtained is subjected to a high-temperature and high-pressure cooking sterilization tester (RCS-40RTGN manufactured by Hisaka Manufacturing Co., Ltd.).
After being placed in the mold, the pressure was increased, the ambient temperature was increased to 115 ° C., and the temperature was maintained at 115 ° C. for 30 minutes. afterwards,
The sample bag was taken out of the tester and evaluated according to the following criteria. A sample with a rating of ○ has heat resistance and is excellent. X: When a wrinkle state occurs in the sample bag or when the transparency is deteriorated. ：: When there is no wrinkle state in the sample bag and there is not much difference from before appearance temperature is applied.

(3) Haze: The haze (1) of the sample bag sterilized at 115 ° C. for 30 minutes by the above method.
Was measured in accordance with JIS-K7105. The smaller the value, the higher the transparency and the better.

(4) Vertical Tensile Modulus (Flexibility): I
In accordance with SO-R1184, 115
A sample bag sterilized at 30 ° C. for 30 minutes was cut out, and the tensile modulus in the vertical direction was measured by an Instron type autograph. The smaller the value, the more flexible and excellent.

(5) Dropping strength: 115 in the above method
A sample bag containing distilled water sterilized at 30 ° C. for 30 minutes
In an atmosphere of ° C, the bag was dropped three times from a height of 2 m by parallel drop, and then three times from a height of 2 m by vertical drop. did.

In addition, the ethylene and ethylene used in Examples and Comparative Examples
The α-olefin copolymer was synthesized as follows. Synthesis Example Preparation of Ethylene / α-Olefin Copolymer The catalyst was prepared by the method described in JP-A-61-130314. That is, to 2.0 mmol of the complex ethylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, methylammonoxane (manufactured by Toyo Stouffer Co., Ltd.) was added 1000 times as much as the above complex, and diluted to 10 liters with toluene. Thus, a catalyst solution was prepared, and polymerization was performed by the following method. A mixture of ethylene and 1-hexene was added to a 1.5-liter stirred autoclave-type continuous reactor in which
3% by weight, and the pressure in the reactor was 130
The reaction was performed at a temperature of 105 ° C. while maintaining the pressure at 0 kg / cm ² . After the reaction was completed, the MFR was 2.2 g / 10 min, and TREF
The peak temperature of the elution curve due to
A hexene copolymer “PE-1” was obtained. A catalyst was prepared and polymerized in the same manner as described above except that the composition of 1-hexene and the polymerization temperature during polymerization were changed, and the MFR was 2.2 g.
/ 10 min, peak temperature of elution curve by TREF is 70
Ethylene-1-hexene copolymer "PE-2"
I got

Example 1 As the polyolefin resin material constituting the outer layer, the ethylene content was 5.9 mol% and the MFR was 6.0 g / 10.
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

As the inner layer, “PE-1” and high-density polyethylene (Novatech HD HJ562, manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm ³⁾ ) Was blended at a ratio of 90:10, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 55 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve was 56% or less, and the H / M was 48%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 2.5 g / 10 minutes and a Vicat softening temperature of 81 ° C.

The resin material of the inner and outer layers was converted to a two-layer, two-layer water-cooled inflation molding machine (Die diameter: 100
mmφ, die lip; 3mm, die temperature; 200 ° C)
Using a 250 μm laminated body (outer layer thickness 37.5 μm,
A tubular laminate having an intermediate layer thickness of 212.5 μm) and a folded diameter of 200 mm was formed. Table 1 shows the evaluation results.

Example 2 As the polyolefin resin material constituting the outer layer, the extrapolative melting end temperature of the melting peak obtained by differential scanning calorimetry (DSC) was 113 ° C., and the MFR was 2.8 g / 1.
For 0 minutes, high-pressure low-density polyethylene (HP-LD) having a Vicat softening temperature of 98 ° C. was used.

The inner layer was made of "PE-1" and a high-density polyethylene (Novatech HD HJ562, manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was mixed at a ratio of 90:10, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 55 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve was 56% or less, and the H / M was 48%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 2.5 g / 10 minutes and a Vicat softening temperature of 81 ° C.

Each of the resin materials of the inner and outer layers was set in the above-mentioned two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 1 shows the results.

Example 3 As a polyolefin resin material constituting the outer layer, a density produced using a Ziegler type catalyst was 0.921 g /
cm ¹ , MFR 1.1 g / 10 min, Vicat softening temperature 102 ° C. ethylene / 1-butene copolymer (LL)
D) was used.

The inner layer was made of “PE-1” and a high-density polyethylene (“Novatech HD HJ562” manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was mixed at a ratio of 90:10, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 55 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve was 56% or less, and the H / M was 48%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 2.5 g / 10 minutes and a Vicat softening temperature of 81 ° C.

Each of the resin materials of the inner and outer layers was set in the above-mentioned two-layer two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 1 shows the results.

Example 4 As the polyolefin resin material constituting the outer layer, the ethylene content was 5.9 mol% and the MFR was 6.0 min / 10.
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

The inner layer was made of "PE-1" and a high-density polyethylene ("Novatech HD HJ562" manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was blended at a ratio of 70:30, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF is 55 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve is 45% or less, and the H / M is 30%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 3.1 g / 10 minutes and a Vicat softening temperature of 101 ° C.

The resin materials of the inner and outer layers were respectively set in the above-mentioned two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd., and subjected to water-cooled inflation molding under the above-mentioned conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 1 shows the results.

Example 5 As the polyolefin resin material constituting the outer layer, the ethylene content was 5.9 mol% and the MFR was 6.0 min / 10.
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

The inner layer was made of “PE-2” and a high-density polyethylene (“Novatech HD HJ562” manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was mixed at a ratio of 90:10, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 70 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve was 57% or less, and the H / M was 46%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 2.5 g / 10 min and a Vicat softening temperature of 98 ° C.

The resin materials of the inner and outer layers were respectively set in the above-mentioned two-layer two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd., and subjected to water-cooled inflation molding under the above-mentioned conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 1 shows the results.

Example 6 As the polyolefin resin material constituting the outer layer, "P
E-2 "and high-density polyethylene (Nippon Polychem Co., Ltd.)
Manufactured by Novatec HD HJ562, MFR;
7 g / 10 min, density: 0.964 g / cm ³ ) 90:
A polyethylene resin composition (ethylene / 1-hexene copolymer:
L-LD). The resin composition is a mixture containing a low crystalline component and a high crystalline component, having a density of 0.913 g / cm ³ , an MFR of 2.5 g / 10 min, and a Vicat softening temperature of 98 ° C.

The inner layer was made of "PE-1" and a high-density polyethylene (Novatech HD HJ562, manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was mixed at a ratio of 90:10, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 55 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve was 56% or less, and the H / M was 48%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 2.5 g / 10 minutes and a Vicat softening temperature of 81 ° C.

The resin material for the inner and outer layers was set in each of the above-mentioned two-layer, two-layer water-cooled inflation molding machines manufactured by Placo Co., and subjected to water-cooled inflation molding under the above conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 1 shows the results.

Comparative Example 1 The polyolefin resin material constituting the outer layer had an ethylene content of 5.9 mol% and an MFR of 6.0 min / 10
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

For the inner layer, “PE-2” was used alone. The resin material had an elution peak temperature of 70 ° C. in an elution curve by TREF and an MFR of 2.2 g / 10 g.
Min, the Vicat softening temperature is 93 ° C.

Each of the resin materials of the inner and outer layers was set in the above-mentioned two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 2 shows the results. Although the outer layer does not adhere to the upper seal bar and has good transparency, flexibility and dropping strength, it is not preferable because of poor heat resistance.

Comparative Example 2 The polyolefin resin material constituting the outer layer had an ethylene content of 5.9 mol% and an MFR of 6.0 min / 10
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

The inner layer was made of Mitsui Chemicals Co., Ltd., trade name “Ultzex 1020L” (the elution peak temperature of the low crystalline component in the elution curve by TREF was 66 ° C., and the low crystalline component relative to the entire area of the elution curve was The area ratio below the peak temperature is 52%, the H / M is 3.5, the MFR of the resin composition is 2.0 g / 10 min, the Vicat softening temperature is 93 ° C., and ethylene / 4-methylpentene-1 copolymer. Was used.

Each of the resin materials of the inner and outer layers was set in the above-described two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd., and subjected to water-cooled inflation molding under the above conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 2 shows the results. This is not preferable since the outer layer does not adhere to the upper seal bar and the flexibility and the dropping strength are good, but the transparency and the heat resistance are inferior.

Comparative Example 3 The polyolefin resin material constituting the outer layer had an ethylene content of 5.9 mol% and an MFR of 6.0 min / 10
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

The inner layer was made by Nippon Polychem Co., Ltd.
Trade name "Novatech LL UF230" (the elution peak temperature of the low crystalline component in the elution curve by TREF is 81 ° C, the area ratio below the peak temperature of the low crystalline component to the entire area of the elution curve is 52%, and the H / M is 1.2, M of the resin composition
FR: 1.1 g / 10 min, Vicat softening temperature: 102
° C, ethylene / 1-butene).

The resin materials for the inner and outer layers were set in the above-mentioned two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd., and subjected to water-cooled inflation molding under the above conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 2 shows the results. This is not preferable because the outer layer does not adhere to the upper seal bar and the heat resistance and the dropping strength are good, but the transparency and flexibility are inferior.

Comparative Example 4 As a polyolefin resin material constituting the outer layer, the density produced using a Ziegler type catalyst was 0.910 g /
An ethylene / 4-methylpentene-1 copolymer (L-LD) having a cm ³ , an MFR of 2.0 g / 10 min, and a Vicat softening temperature of 93 ° C. was used.

The inner layer was made of “PE-2” and a high-density polyethylene (Novatech HD HJ562, manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was mixed at a ratio of 90:10, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 70 ° C., the area ratio of the peak temperature of the low crystalline component to the entire area of the elution curve was 57% or less, and the H / M was 46%. A mixture containing a low crystalline component and a high crystalline component, the resin composition having an MFR of 2.5 g / 10 min and a Vicat softening temperature of 98 ° C.

The resin materials of the inner and outer layers were set in the above-mentioned two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd., and subjected to water-cooled inflation molding under the above conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 2 shows the results. Although this is good in heat resistance, transparency, flexibility and dropping strength, it is not preferable because the outer layer adheres to the upper seal bar, thereby lowering work efficiency and causing trouble.

Comparative Example 5 As the polyolefin resin material constituting the outer layer, the ethylene content was 5.9 mol% and the MFR was 6.0 min / 10.
For this, a polypropylene resin (PP: propylene / ethylene random copolymer) having a Vicat softening temperature of 130 ° C. was used.

The inner layer was made of "PE-2" and a high-density polyethylene (Novatec HD HJ562, manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.964 g / cm). ³ ) was mixed at a ratio of 40:60, and a polyethylene-based resin composition obtained by pelletizing was used. In this resin composition, the elution peak temperature of the low crystalline component in the elution curve by TREF was 70 ° C., the area ratio of the low crystalline component peak temperature or less to the entire area of the elution curve was 30%, and the H / M was 15%. A mixture containing a low crystalline component and a high crystalline component, the MFR of the resin composition being 4.4 g / 10 min and the Vicat softening temperature being 120 ° C.

Each of the resin materials of the inner and outer layers was set in the above-mentioned two-layer, two-layer water-cooled inflation molding machine manufactured by Placo Co., Ltd., and subjected to water-cooled inflation molding under the above conditions.
A laminate having a thickness of 0 μm was obtained and evaluated. Table 2 shows the results. This is not preferable because the outer layer does not adhere to the upper seal bar and the heat resistance is good, but the transparency, flexibility and bag drop strength are inferior.

[0120]

[Table 1]

[0121]

[Table 2]

[0122]

The laminate of the present invention not only has good hygiene, but also has remarkably excellent flexibility and transparency, and is excellent in heat resistance, bag drop strength which is problematic in transportation and handling,
Furthermore, the heat sealability is excellent. Therefore, it can be suitably used as a soft bag in the medical field such as a medical bag, particularly an infusion bag. In addition, the medical bag of the present invention not only has good hygiene properties, but also has extremely excellent flexibility and transparency, heat resistance, and pinhole resistance (piercing strength) which is a problem during transportation. Since it is excellent, it can be suitably used in the medical field such as an infusion bag.

[Brief description of the drawings]

FIG. 1 shows the TREF elution curve for two peaks.

FIG. 2 shows a TREF elution curve for three peaks. FIG. 2A shows a case where a peak having a lower peak height than the elution peak of the low crystalline component exists in a temperature region lower than the elution temperature of the elution peak of the low crystalline component. FIG. 2 (b)
Represents a case where a peak having a lower peak height than the elution peak of the low crystalline component exists between the elution peak of the high crystalline component and the elution peak of the low crystalline component.

[Explanation of symbols]

 1 Elution peak of high crystalline component 2 Elution peak of low crystalline component

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 23/08 C08L 23/10 23/10 A61J 1/00 331A 331C F term (reference) 3E064 BA24 BA27 BA30 BB03 BC01 BC13 BC15 BC18 EA30 FA04 4F100 AK03A AK06A AK07A AK62A AK62B AK62K BA02 GB17 GB66 JA04A JA04B JA06B JA11B JA13A JA20B JJ03 JK10 JK13 JK14 JK17 JN01 YY00A YY00B 4J002 BB02X BB05YBB

Claims (3)

[Claims] 1. A laminate comprising at least an outer layer and an inner layer in this order, wherein the outer layer is formed of a polyolefin resin material satisfying the following physical properties (A1), and the inner layer is composed of a low crystalline component and a high crystalline component. Containing ethylene and carbon number 3
A laminate comprising a polyethylene-based resin material whose main component is a copolymer with α-olefins of Nos. 1 to 18 satisfying all of the following physical properties (B1) to (B5). (A1) Vicat softening temperature Ta; Tb <Ta ≦ 140 ° C. (B1) Temperature rise elution fractionation (TRE) of the copolymer component
F) In the elution curve, the elution peak temperature of the low crystalline component is in the range of 45 to 85 ° C. (B2) Temperature rise elution fractionation (TRE) of the copolymer component
F) In the elution curve, the peak height of the low crystalline component is H
When the height of the minimum valley between the peak of the low crystal component and the peak of the high crystal component is M, the value of H / M is 9 or more. (B3) Elevated temperature elution fractionation (TRE) of the copolymer component
F) The ratio of the area of the low crystalline component below the elution peak temperature to the entire area of the elution curve is 35% or more. (B4) The copolymer component has an MFR of 0.1 to 20 g /
10 minutes. (B5) The Vicat softening temperature Tb is in the range of 65 to 125 ° C. 2. The method according to claim 1, wherein the outer layer comprises a polypropylene resin satisfying the above physical properties, 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), and a density of 0. .910 g /
2. The laminate according to claim 1, comprising a resin material selected from the group consisting of a copolymer of ethylene having a cm ³ or more and an α-olefin having ^{3 to} 18 carbon atoms. 3. 3. A medical bag comprising the laminate according to claim 1.