JPH11164874A - Resin composition for medical transfusion vessel and medical transfusion vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical transfusion vessel whose thickness is uniform and whose transparency, softness, heat resistance, deformation resistance, etc., are well-balanced, and which is kept transparent after being filled with transfusion liquid at a high temperature or after the retort sterilization step at 110 deg.C. SOLUTION: This medical transfusion vessel is made of (A) 90-40 wt.% of a low density polyethylene whose melt flow rate(MFR) is 0.5-5 g/10 min and density 0.925-0.935 g/cm<3> produced by a high pressure radical polymerization, and (B) 60-10 wt.% of an ethylene copolymer whose density is 0.905-0.925 g/cm<3> and MRF 0.5-10 g/10 min, and which has plural peaks in the elution temperature- elution quantity curve by the TREF method, and whose highest temperature peak is 90 deg.C or higher and the relation between the temperature of crystallization (Tc: deg.C) and the density (d: g/cm<3> ) is to satisfy the following equation: Tc<=300 d-172. The MRF of the material of the vessel is 0.5-5 g/10 min, the melt tension is 3 g or higher, and the optical transmission rate by 450 nm wavelength (TBD) is higher than either of the optical transmission rates of the component (A) and the component (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in uniformity of thickness distribution of a container when formed by hollow molding, and is excellent in balance of transparency, flexibility, heat resistance, bending resistance and the like.
The present invention relates to a medical infusion container having a small decrease in transparency even after filling at a high temperature or a retort sterilization step at 110 ° C.

[0002]

2. Description of the Related Art Ziegler-catalyzed ethylene / α-olefin copolymers (linear low-density polyethylene LLDP)
E) has moderate flexibility, and is excellent in moldability, transparency, and impact strength, and is therefore widely used as a packaging material in place of soft vinyl chloride or soft polypropylene (for example, JP-A-52-135386). No., JP-A-61
-284439). Although LLDPE has begun to be widely used in the field of medical infusion containers, the processability has been improved by adding a small amount of high-pressure polyethylene (LDPE) due to the drawback of processability in the case of the hollow molding method. A medical infusion container has been proposed (JP-A-3-168231). Furthermore, in recent years, medical infusion containers have the above-mentioned characteristics,
Higher transparency, flexibility, moldability, heat-resistant deformation during sterilization at high temperatures, and anti-blocking properties are also required. For such required properties, LLDPE by Ziegler catalyst has a limit in transparency, and has a relatively large amount of low molecular weight components, which tends to cause solidification of the surface after container molding and generation of fine particles during storage period, blocking, Even if LDPE is blended, it is still insufficient as a material for medical infusion containers.

Recently, a container using LLDPE having excellent transparency using a metallocene catalyst has been developed (Japanese Patent Laid-Open Publication No.
SUMMARY OF THE INVENTION Although attention has been focused on this metallocene-based LLDPE, L
Compared to LDPE, the molecular weight distribution is narrower and the critical shear rate is low. Therefore, when molding is performed under ordinary molding conditions, the surface of the molten resin surface is significantly rough at the exit of the die, and the transparency of the container is reduced. Although it is possible to reduce the molding speed to solve this surface roughness, it is possible to increase the manufacturing cost, but of course, due to the low melt tension, the drawdown is severe and the thickness of the entire container becomes extremely uneven, Not suitable for infusion containers by hollow molding. The hollow molding method does not require heat sealing at the bottom of the container and can significantly improve the drop strength of the container compared to the film forming method, but the shear rate during molding is several times that of film forming. Therefore, this tendency becomes more pronounced. As another method for improving the moldability, a method for solving the problem by blending a low-density polyethylene by a high-pressure radical polymerization method has been disclosed (JP-A-7-125538, JP-A-6-65).
No. 443, JP-A No. 7-26080), the metallocene-based LLDPE has a low melting point and poor heat resistance, and has a problem in compatibility between the two. Transparent protrusions called "a" are generated. The protrusions may be erroneously recognized as foreign matter after filling the contents, and have disadvantages such as being unfavorable. Therefore, at present, a material for an infusion container having an excellent balance between hollow moldability, transparency and heat resistance has not yet been obtained.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to provide a well-balanced hollow moldability, transparency and heat resistance, and to reduce the generation of fine particles during storage of contents. Is to provide.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in view of the above situation and found that a high density LDPE having a specific density and a melt flow rate can be added to a specific density range having a specific crystallization temperature range. It has been found that, by blending the LLDPE in a specific ratio, a good balance between moldability and heat resistance is obtained, and the material becomes excellent in transparency even after retort treatment, and the present invention has been completed.

That is, in the present invention, first, (A) the MFR is 0.
5-5g / 10min, density 0.925-0.935
g / cm ³ of high-density radical polymerization, 90 to 40% by weight of low-density polyethylene, and (B) 60 to 10% by weight of an ethylene copolymer satisfying the following conditions (a) to (e): There 0.5 to 5 g / 10min, a melt tension than 3g, and 450nm the light transmittance of the wavelength of the (T _BD) is the component (a) and (B) each of the light transmittance of the component (T _a) And a resin composition for a medical infusion container by a hollow molding method, characterized by being higher than any one of ( _B ) and (T _B ), and a medical infusion container made of the composition. (A) Density 0.905 to 0.925 g / cm ³ (b) Melt flow rate (MFR) 0.5 to 10 g / 10 min (c) Elution temperature-elution amount curve by continuous heating elution fractionation method (TREF) There are multiple peaks, and the peak of the highest temperature exists at 90 ° C or higher. (D) The relationship between the crystallization temperature (Tc: ° C.) and the density (d: g / cm ³ ) by DSC satisfies Tc ≦ 300d-172. In the above, the ethylene copolymer of the component (B) further has (e) a composition distribution parameter Cb of 1.08.
Those which also satisfy the condition of ~ 2.00 are preferred. The medical infusion container obtained from the above composition has a new and unique physical property balance.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the resin composition for medical infusion containers of the present invention, (A) the low-density polyethylene obtained by the high-pressure radical polymerization method is a branched low-density polyethylene, and is generally a tank-type reactor or a tubular reactor. Among those obtained by polymerizing ethylene at a pressure of 1400 to 2500 kg / cm ² and a polymerization temperature of 200 to 300 ° C. using a reactor in the presence of a radical initiator, MFR is 0.5
~ 5g / 10min, density 0.925 ~ 0.935g /
cm ³ .

(A) Low density by high pressure radical polymerization
Polyethylene has an MFR of less than 0.5 g / 10 min.
In some cases, poor fluidity causes rough skin or compatibility
Bad, fish eyes were generated on the surface of the container, and 5 g / 10
If it exceeds min, the melt tension of the composition decreases, and
Sometimes it draws down and the thickness distribution becomes poor. Then density
Is 0.925 to 0.935 g / cm^ThreeRange, preferably
Is 0.928 to 0.933 g / cm^ThreeAnd the low density
The density of polyethylene is 0.925 g / cm^ThreeLess than
In general, the density is 0.925 in the present invention.
g / cm^ThreeIt is necessary to use the above. 0.925
g / cm^ThreeIf less, the heat resistance of the container is poor,
Heat deformation due to sterilization. 0.935
g / cm ^ThreeAnything over is difficult to manufacture.

The ethylene copolymer (B) in the present invention is a copolymer of ethylene and at least one selected from α-olefins having 3 to 20 carbon atoms. This carbon number 3-2
The α-olefin of 0 preferably has 3 to 3 carbon atoms.
12, specifically propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and the like. The content of these α-olefins is desirably selected in a range of usually 30 mol% or less, preferably 20 mol% or less.

The ethylene copolymer (B) is (a) a dense
Degree 0.905-0.925g / cm ^Three, (B) Meltov
Low rate (MFR) 0.5 to 10 g / 10 min,
(C) Elution temperature by continuous heating elution fractionation method (TREF)
-If there are multiple peaks in the elution curve,
(D) crystallization temperature by DSC
Degree (Tc: ° C) and density (d: g / cm^Three) Must satisfy the following expression: Tc ≦ 300d−172.

The density (a) of the ethylene copolymer (B) is from 0.905 to 0.925 g / cm ³ , preferably from 0.910 to 0.920 g / cm ³ . Density is 0.
If it is less than 905 g / cm ³ , the heat resistance of the container is inferior.
If it exceeds 25 g / cm ³ , transparency is not sufficient.

The copolymer (b) has an MFR of 0.5-1.
0 g / 10 min, preferably 0.8 to 8 g / 10 mi
n, particularly preferably 1 to 4 g / 10 min. MF
If R is less than 0.5 g / 10 min, the fluidity is poor and the surface becomes rough during molding, or the compatibility with the low-density polyethylene as the component (A) is poor, and irregularities due to fish eyes occur on the surface of the container. If it exceeds / 10 min, the drawdown property is inferior and the wall thickness becomes non-uniform at the time of hollow molding, the compatibility with low-density polyethylene is reduced, and fish eyes and projections are easily generated on the surface of the container.

The ethylene copolymer (B) of the present invention comprises (c)
In the elution temperature-elution amount curve obtained by the continuous heating elution fractionation method (TREF), there are a plurality of peaks, and the peak of the highest temperature must exist at 90 ° C. or more.
The presence of this peak increases the melting point and the crystallinity, thereby improving the heat resistance and rigidity of the molded article. FIG. 1 shows the elution temperature-elution amount (TR) of the copolymer of the present invention.
EF) curve was shown. FIG. 2 shows a typical metallocene-catalyzed elution temperature-elution amount (TREF) curve of a copolymer, with a single peak. Since the copolymer having a single TREF peak has a low melting point, it has poor heat resistance and easily undergoes thermal deformation during retort sterilization.

The method of measuring TREF according to the present invention is as follows. A heat-resistant stabilizer is added to the sample, and the sample is heated and dissolved at 135 ° C. in ODCB so that the sample concentration becomes 0.05% by weight. After injecting 5 ml of the heated solution into a column filled with glass beads, the solution is cooled to 25 ° C. at a cooling rate of 0.1 ° C./min, and the sample is deposited on the surface of the glass beads. Next, the column temperature is raised at a constant rate of 50 ° C./hr while flowing ODCB through the column at a constant flow rate, and samples that can be dissolved in the solution at each temperature are sequentially eluted.
At this time, as for the concentration of the sample in the solvent, the absorption of the asymmetric stretching vibration of methylene at a wave number of 2925 cm ^-1 is continuously detected by an infrared detector. From this concentration, an elution temperature-elution amount curve can be obtained. TREF analysis is a very small sample,
Since the change in the elution rate with respect to the temperature change can be continuously analyzed, relatively fine peaks that cannot be detected by the fractionation method can be detected.

The (B) ethylene copolymer of the present invention further has the following relationship: (d) The relationship between the crystallization temperature (Tc: ° C.) and the density (d: g / cm ³ ) by DSC is as follows: Tc ≦ 300d−
172 must be satisfied. Those that do not satisfy these relationships have poor transparency improving effects. Ethylene ・ α
-The crystallization temperature of the olefin copolymer increases as the density increases. When the TREF curve has a single peak, the crystallization temperature is low for the density, and the crystallization temperature for the copolymer having a plurality of peaks is high for the density. T
A copolymer having a single REF curve peak satisfies this relationship, so that transparency is good, but heat resistance is poor. Further, conventionally known ethylene / α-olefin copolymers using a Ziegler-type catalyst have a plurality of peaks in a TREF curve, but do not satisfy the relationship of Tc ≦ 300d−172, and the transparency of the present composition is poor. . Here, the measurement of Tc is performed by using a sample of 3 to 6 mg as a sheet of about 0.2 mm, heating and holding at 200 ° C. for 5 minutes by a differential scanning calorimeter (DSC), and then lowering the temperature to room temperature at a rate of 10 ° C./min. The temperature at the peak of the observed crystallization peak is measured and determined.

The (B) ethylene copolymer of the present invention further comprises (e) a composition distribution parameter Cb of 1.08 to 2.0.
0, more preferably in the range of 1.12 to 1.70. If it is less than 1.08, the heat resistance becomes poor,
If it exceeds 2.00, the transparency may be poor.

In the present invention, the method for measuring the composition distribution parameter Cb of the ethylene copolymer is as follows. That is, a heat-resistant stabilizer is added to the sample, and the sample is heated and dissolved at 135 ° C. in ODCB so that the sample concentration becomes 0.2% by weight.
The heated solution is transferred to a column filled with diatomaceous earth (Celite 545), filled and cooled to 25 ° C. at a rate of 0.1 ° C./min, and the sample is deposited on the celite surface. Next, while flowing ODCB through the column at a constant flow rate, while gradually increasing the column temperature to 120 ° C. in steps of 5 ° C.,
At each temperature, a solution in which the sample is dissolved is collected. After cooling the solution, the sample is reprecipitated with methanol, filtered and dried to obtain samples at each elution temperature. The weight fraction and the degree of branching (the number of branches per 1000 carbon atoms) of the separated sample are measured. The degree of branching is measured by ¹³ C-NMR.

For each fraction collected at 30 ° C. to 90 ° C. by such a method, the degree of branching is corrected as follows. That is, the degree of branching measured with respect to the elution temperature is plotted, and the correlation is approximated to a straight line by the least squares method to create a calibration curve. The correlation coefficient of this approximation is large enough. The value obtained from this calibration curve is defined as the degree of branching of each fraction. Note that, for a fraction collected at an elution temperature of 95 ° C. or higher, this correction is not performed because a linear relationship is not always established between the elution temperature and the degree of branching.

Next, the weight fraction w of each fraction
The _i, the amount of change in the degree of branching b _i per the elution temperature 5 ° C. (b _i
Obtaining the relative concentration c _i is divided by -b _i-1), by plotting the relative concentration against the branching degree to obtain a composition distribution curve. This composition distribution curve is divided by a certain width, and the composition distribution parameter Cb is calculated from the following equation.

[0020]

(Equation 1)

Here, c _j and b _j are the relative density and branching degree of the j-th section, respectively. Composition distribution parameter C
b becomes 1.0 when the composition of the sample is uniform, and becomes larger as the composition distribution becomes wider.

The ethylene copolymer (B) of the present invention is not particularly limited as long as it satisfies the above-mentioned conditions, but the preferred production method is at least an organic cyclic compound having at least a conjugated double bond and a compound of the periodic table IV. In the present invention, ethylene and an α-olefin having 3 to 20 carbon atoms are copolymerized in the presence of a catalyst containing a group IV transition metal compound. Specifically, it is preferable to polymerize with a catalyst obtained by bringing the following components (a1) to (a4) into contact with each other. That is, (a
1): General formula Me ¹ R ¹ _p R ² _q (OR ³ ) _r X ¹
A transition metal compound of Group IV of the periodic table represented by _4-pqr (where Me ¹ represents Zr, Ti, Hf, R ¹ and R
³ is a hydrocarbon group having 1 to 24 carbon atoms, R ² is 2, 4
-A pentanedionate ligand or a derivative thereof, or a derivative such as a dibenzoylmethanato ligand or a benzoylacetonato ligand; X ¹ represents a halogen atom; p, q and r each represent 0 ≦ p ≦ 4; 0 ≦ q ≦ 4, 0 ≦ r ≦
4, 0 ≦ p + q + r ≦ 4).
(A2): General formula Me ² R ⁴ _m (OR ⁵ ) _n X ² _{zm- n}
Wherein Me ² is a group I-III element of the periodic table, R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 24 carbon atoms, X ² is a halogen atom or a hydrogen atom ( ^Two
Is a hydrogen atom, Me ² is limited to a group III element of the periodic table), z is a valence of Me ² , m and n are respectively 0 ≦ m ≦ z, 0 ≦ n ≦ z And 0 ≦ m + n ≦ z
(A3): an organic cyclic compound having a conjugated double bond, and (a4): Al-OA.
A catalyst obtained by bringing a modified organoaluminum oxy compound containing 1 bond and / or a boron compound into contact with each other.

The general formula Me ¹ R ^{1 of the} catalyst component (a1)
_p R ² _q (OR ³⁾ the periodic table represented by _r X ¹ _4-pqr
In the formula of the group IV transition metal compound, Me ¹ is Zr, Ti, Hf
Is shown. The type of these transition metals is not limited, and a plurality of transition metals can be used. However, it is particularly preferable that zirconium having excellent weather resistance of the copolymer is contained.
R ¹ and R ³ are each a hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 24 carbon atoms.
8, specifically, an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group; an alkenyl group such as a vinyl group and an allyl group; a phenyl group, a tolyl group, a xylyl group, a mesityl group, and an indenyl group And aralkyl groups such as a benzyl group, a trityl group, a phenethyl group, a styryl group, a benzhydryl group, a phenylbutyl group, and a neofuyl group. These may have branches. R ² represents a 2,4-pentanedionato ligand or a derivative thereof, or a derivative such as a dibenzoylmethanato ligand or a benzoylacetonato ligand. X ¹ represents a halogen atom such as fluorine, iodine, chlorine and bromine, and p, q and r are respectively 0 ≦ p ≦ 4, 0 ≦ q ≦ 4, 0 ≦ r ≦ 4, 0 ≦ p + q
+ R ≦ 4.

Examples of the compound represented by the general formula of the catalyst component (a1) include tetramethyl zirconium, tetraethyl zirconium, tetrabenzyl zirconium,
Tetrapropoxy zirconium, tripropoxy monochloro rhodiconium, dipropoxy dichloro zirconium, tetrabutoxy zirconium, tributoxy monochloro rhodiconium, dibutoxy dichloro zirconium,
Examples thereof include tetrabutoxytitanium and tetrabutoxyhafnium, and specific examples of the 2,4-pentanedionato ligand or a derivative thereof include tetra (2,4-
(Pentanedionato) zirconium, tri (2,4-pentanedionato) chloride zirconium, di (2,4-
Pentandionato) diethoxide zirconium, di (2,4-pentanedionato) di-n-propoxide zirconium, di (2,4-pentanedionato) di-n
-Butoxide zirconium, di (2,4-pentanedionato) dibenzyl zirconium, di (2,4-pentanedionato) dineofyl zirconium, tetra (dibenzoyl methanate) zirconium, di (dibenzoyl methanate) ) Diethoxide zirconium, di (dibenzoyl methanate) di-n-propoxide zirconium, di (dibenzoylacetonate) diethoxide zirconium, di (dibenzoylacetonate) di-n-
Propoxide zirconium, di (dibenzoylacetonate) di-n-butoxide zirconium and the like can be mentioned, and a mixture of two or more of these may be used.

The general formula Me ² R ^{4 of the} catalyst component (a2)
_m (OR ⁵ ) _n X ² _zmn
² represents an element of Groups I to III of the periodic table, and includes lithium, sodium, potassium, magnesium, calcium, zinc,
Boron, aluminum and the like. R ⁴ and R ⁵ are each a hydrocarbon group having 1 to 24 carbon atoms, preferably 1 to 24 carbon atoms.
12, more preferably 1 to 8, specifically alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group and butyl group; alkenyl groups such as vinyl group and allyl group; phenyl group, tolyl group, Aryl groups such as a xylyl group, a mesityl group, an indenyl group, and a naphthyl group; and aralkyl groups such as a benzyl group, a trityl group, a phenethyl group, a styryl group, a benzhydryl group, a phenylbutyl group, and a neofuyl group. These may have branches. X ² represents a halogen atom or a hydrogen atom such as fluorine, iodine, chlorine and bromine. However, when X ² is a hydrogen atom, Me ² is limited to a group III element of the periodic table exemplified by boron, aluminum and the like. Z represents the valence of Me ² , m and n are integers satisfying 0 ≦ m ≦ z and 0 ≦ n ≦ z, respectively, and 0 ≦ m + n ≦ z.

Examples of the compound represented by the general formula of the catalyst component (a2) include organic lithium compounds such as methyllithium and ethyllithium; dimethylmagnesium, diethylmagnesium, methylmagnesium chloride,
Organic magnesium compounds such as ethyl magnesium chloride; organic zinc compounds such as dimethyl zinc and diethyl zinc; organic boron compounds such as trimethyl boron and triethyl boron; trimethyl aluminum, triethyl aluminum, tripropyl aluminum, triisobutyl aluminum, trihexyl aluminum and trihexyl aluminum Decyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, diethyl aluminum ethoxide,
Derivatives such as organoaluminum compounds such as diethylaluminum hydride are exemplified.

Examples of the organic cyclic compound having a conjugated double bond of the catalyst component (a3) include: 1) a carbon ring having two or more, preferably 2 to 4, more preferably 2 to 3 conjugated double bonds. A) a cyclic hydrocarbon compound having 1 or 2 or more and having a total carbon number of 4 to 24, preferably 4 to 12) 2) the cyclic hydrocarbon compound of the above 1) has 1 to 6 hydrocarbon groups (typical) A) a cyclic hydrocarbon compound partially substituted with an alkyl group or an aralkyl group having 1 to 12 carbon atoms; 3) 2 or more, preferably 2 to 4, more preferably 2 to 3 conjugated double bonds. An organosilicon compound having a cyclic hydrocarbon group having one or more carbocycles, and having a total carbon number of 4 to 24, preferably 4 to 12 4) The hydrogen of the cyclic hydrocarbon group of the above 3) is , Partially substituted with 1 to 6 hydrocarbon groups 5) An alkali metal salt (sodium or lithium salt) of a compound represented by the above 1) to 4).

One of the cyclic hydrocarbon compounds suitable as the component (a3) is represented by the following general formula.

[0029]

Embedded image

Wherein R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ^{10 each} independently represent hydrogen or a hydrocarbon group having 1 to 10 carbon atoms;
Any two of the hydrocarbon groups can together form a cyclic hydrocarbon group. The above hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, t-butyl group, hexyl group and octyl group; alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group. An aryl group such as a phenyl group; an aryloxy group such as a phenoxy group;
An aralkyl group such as a benzyl group is included. Further, when any two of the above hydrocarbon groups together form a cyclic hydrocarbon group, the skeleton thereof includes cycloheptatriene, aryl and a condensed ring thereof. Among the cyclic hydrocarbon compounds represented by the above general formula, preferred are cyclopentadiene, indene, azulene and the like, and further substituted with alkyl, aryl, aralkyl, alkoxy or aryloxy having 1 to 10 carbon atoms. And the like. When the cyclic hydrocarbon compound represented by the above general formula is an alkylene group (having usually 2 carbon atoms)
To 8, preferably 2 to 3, or an alkylidene group (the number of carbon atoms of which is usually 2 to 8, preferably 2 to 3).

The organosilicon compound having a cyclic hydrocarbon group can be represented by the following general formula. Here ^{_{A L SiR 11 M X 3 4}} -LM, A represents a cyclopentadienyl group, substituted cyclopentadienyl group, indenyl group, the cyclic hydrocarbon group exemplified by substituted indenyl group, R ¹¹ is methyl Groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, pentyl groups, hexyl groups, alkyl groups such as octyl groups, alkenyl groups such as vinyl groups; methoxy groups, ethoxy groups,
As shown by an alkoxy group such as a propoxy group and a butoxy group; an aryl group such as a phenyl group, a tolyl group and a xylyl group; an aryloxy group such as a phenoxy group; an aralkyl group such as a benzyl group, a phenethyl group, a styryl group, and a neofuyl group. Having 1 to 24 carbon atoms, preferably 1 to 12 carbon atoms.
In which R ¹¹ is not only n- but also various structural isomers such as iso-, s-, t- and neo-. X ³ is fluorine,
Represents a halogen atom of iodine, chlorine, or bromine, and L and M are in the range of 0 <L ≦ 4, 0 ≦ M ≦ 3, and preferably 1 ≦ L + M ≦ 4.

Therefore, the following compounds are included in the organic cyclic hydrocarbon compound usable as the component (a3). Cyclopentadiene, methylcyclopentadiene, ethylcyclopentadiene, t-butylcyclopentadiene, propylcyclopentadiene, isopropylcyclopentadiene, butylcyclopentadiene, isobutylcyclopentadiene, sec-butylcyclopentadiene, 1-methyl-3-ethylcyclopentadiene, -Ethyl-3-methylcyclopentadiene, 1-methyl-3-propylcyclopentadiene, 1
-Propyl-3-methylcyclopentadiene, 2-ethyl-5-isopropylcyclopentadiene, 2-methyl-5-phenylcyclopentadiene, 2-ethyl-3,
5-dimethylcyclopentadiene, hexylcyclopentadiene, octylcyclopentadiene, 1,2-dimethylcyclopentadiene, 1,3-dimethylcyclopentadiene, 1,2,4-trimethylcyclopentadiene, 1,2,3,4-tetramethyl Substituted cyclopentadiene such as cyclopentadiene and pentamethylcyclopentadiene; indene; 2-methylindene; 4-methylindene; 4,7-dimethylindene;
Substituted indene such as 6,7-tetrahydroindene,
Substituted cycloheptatriene such as cycloheptatriene and methylcycloheptatriene, substituted cyclooctatetraene such as cyclooctatetraene and methylcyclooctatetraene, azulene, methylazulene, ethylazulene, and substituted fluorene such as fluorene and methylfluorene A cyclopolyene or substituted cyclopolyene having 7 to 24 carbon atoms,

Dimethylsilylenebiscyclopentadiene, dimethylsilylenebisindene, dimethylsilylenebispropylcyclopentadiene, dimethylsilylenebisbutylcyclopentadiene, diphenylsilylenebiscyclopentadiene, diphenylsilylenebisindene, diphenylsilylenebispropylcyclopentadiene, diphenylsilylenebisbutyl Cyclopentadiene, monocyclopentadienylsilane, dicyclopentadienylsilane, tricyclopentadienylsilane, tetracyclopentadienylsilane, monocyclopentadienylmonomethylsilane, monocyclopentadienylmonoethylsilane, monocyclo Pentadienyldimethylsilane, monocyclopentadienyldiethylsilane, monocyclopentadienyltol Methylsilane, monocyclopentadienyltriethylsilane, monocyclopentadienyl monomethoxysilane, monocyclopentadienyl monoethoxysilane, monocyclopentadienyl monophenoxysilane, monocyclopentadienyl monomethylmonochlorosilane, monocyclopentadi Enyl monoethyl monochlorosilane, monocyclopentadienyl monomethyl dichlorosilane, monocyclopentadienyl monoethyl dichlorosilane, monocyclopentadienyl trichlorosilane, dicyclopentadienyl monomethyl silane,
Dicyclopentadienyl monoethylsilane, dicyclopentadienyldimethylsilane, dicyclopentadienyldiethylsilane, dicyclopentadienylmethylethylsilane, dicyclopentadienyldipropylsilane, dicyclopentadienylethylpropyl Silane, dicyclopentadienyldiphenylsilane, dicyclopentadienylphenylmethylsilane, dicyclopentadienylmethylchlorosilane, dicyclopentadienylethylchlorosilane, dicyclopentadienyldichlorosilane, dicyclopentadienylmonomethoxy Silane, dicyclopentadienyl monoethoxysilane, dicyclopentadienyl monomethoxy monochlorosilane, dicyclopentadienyl monoethoxy monochlorosilane, tricyclopentadienyl monomethyl Rushiran, tri cyclopentadienyl monoethyl silane, tri cyclopentadienyl monomethoxy silane, tri cyclopentadienyl mono silane, tri cyclopentadienyl monochlorosilane,
3-methylcyclopentadienylsilane, bis3-methylcyclopentadienylsilane, 3-methylcyclopentadienylmethylsilane, 1,2-dimethylcyclopentadienylsilane, 1,3-dimethylcyclopentadienylsilane 1,2,4-trimethylcyclopentadienylsilane, 1,2,3,4-tetramethylcyclopentadienylsilane, pentamethylcyclopentadienylsilane,

Monoindenyl silane, diindenyl silane, triindenyl silane, tetraindenyl silane,
Monoindenyl monomethylsilane, monoindenyl monoethylsilane, monoindenyldimethylsilane, monoindenyldiethylsilane, monoindenyltrimethylsilane, monoindenyltriethylsilane, monoindenylmonomethoxysilane, monoindenylmonoethoxysilane , Monoindenyl monophenoxysilane, monoindenyl monomethyl monochlorosilane, monoindenyl monoethyl monochlorosilane, monoindenyl monomethyl dichlorosilane, monoindenyl monoethyl dichlorosilane, monoindenyl trichlorosilane, diindenyl monomethylsilane, Diindenylmonoethylsilane, diindenyldimethylsilane, diindenyldiethylsilane, diindenylmethylethylsilane, diindenyldipropylsilane, Indenyl ethylpropyl silane,
Diindenyldiphenylsilane, diindenylphenylmethylsilane, diindenylmethylchlorosilane, diindenylethylchlorosilane, diindenyldichlorosilane, diindenylmonomethoxysilane, diindenylmonoethoxysilane, diindenylmonomethoxy Monochlorosilane, diindenylmonoethoxymonochlorosilane, triindenylmonomethylsilane, triindenylmonoethylsilane, triindenylmonomethoxysilane, triindenylmonoethoxysilane, triindenylmonochlorosilane, 3-methylindenylsilane , Bis 3-methylindenylsilane, 3-methylindenylmethylsilane, 1,2-dimethylindenylsilane,
Examples include 1,3-dimethylindenylsilane, 1,2,4-trimethylindenylsilane, 1,2,3,4-tetramethylindenylsilane, and pentamethylindenylsilane.

Any one of the above compounds may be an alkylene group (having usually 2 to 8, preferably 2 to 2 carbon atoms).
3) or an alkylidene group (the number of carbon atoms of which is usually 2 to 8,
Compounds linked via preferably 2-3) can also be used as component (a3) of the present invention, such as ethylene biscyclopentadiene, ethylene bispropylcyclopentadiene, ethylene bis Butylcyclopentadiene, isopropylidenebiscyclopentadiene, isopropylidenebisindene, isopropylidenebispropylcyclopentadiene, isopropylidenebisbutylcyclopentadiene,
Bisindenylethane, bis (4,5,6,7-tetrahydro-1-indenyl) ethane, 1,3-propanedienylbisindene, 1,3-propanedienylbis (4,5,6,7 -Tetrahydro) indene, propylenebis (1-indene), isopropylidene (1-indenyl) cyclopentadiene, diphenylmethylene (9-fluorenyl) cyclopentadiene, isopropylidenecyclopentadienyl-1-fluorene and the like.

The modified organoaluminum oxy compound containing an Al—O—Al bond obtained by reacting the organoaluminum compound of the catalyst component (a4) with water is usually obtained by reacting an alkylaluminum compound with water. Modified organoaluminum called aluminoxane, usually 1 to 100, preferably 1 to
It contains 50 Al-O-Al bonds. The modified organic aluminum oxy compound may be linear or cyclic.

The reaction between the organoaluminum and water is usually carried out in an inert hydrocarbon. As the inert hydrocarbon,
Aliphatic, alicyclic and aromatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, benzene, toluene and xylene are preferred. The reaction ratio between water and the organoaluminum compound (water / Al molar ratio) is usually 0.25 / 1 to 1.2.
/ 1, preferably 0.5 / 1 to 1/1.

The boron compound as the catalyst component (a4) includes, for example, triethylammonium tetra (pentafluorophenyl) borate, dimethylanilinium tetra (pentafluorophenyl) borate, butylammonium tetra (pentafluorophenyl) borate, N, N −
Dimethylanilinium tetra (pentafluorophenyl) borate, N, N-dimethylaniliniumtetra (3,5-difluorophenyl) borate and the like can be mentioned.

In the production of the ethylene copolymer (B), a catalyst obtained by bringing the catalyst components (a1) to (a4) into contact with each other is used as an inorganic carrier and / or a particulate polymer carrier (a5). ) Can be used for the polymerization reaction. The inorganic carrier of the component (a5) may be in any shape such as powder, granule, flake, foil, or fiber as long as the original shape is maintained at the stage of preparing the catalyst. Regardless of the shape, those having a maximum length in the range of usually 5 to 200 μm, preferably 10 to 100 μm are suitable. Further, the inorganic carrier is preferably porous, usually,
Its surface area is 50-1000 m ² / g and its pore volume is 0.
In the range of 0.5 to ³ cm ³ / g. As the inorganic carrier, a carbonaceous material, a metal, a metal oxide, a metal chloride, a metal carbonate or a mixture thereof can be used, and these are usually in the air at 200 to 900 ° C. or in an inert gas such as nitrogen or argon. It is used after firing in it.

Suitable inorganic carriers that can be used
Metals include iron, aluminum, nickel, etc.
Can be Further, as metal oxides, groups I to VIII of the periodic table
A single oxide or a composite oxide of
SiO_Two, Al_TwoO_Three, MgO, CaO, B_TwoO_Three, T
iO_Two, ZrO_Two, Fe_TwoO_Three, SiO_Two-Al
_TwoO _Three, Al_TwoO_Three-MgO, Al_TwoO_Three-CaO, A
l_TwoO_Three-MgO-CaO, Al_TwoO_Three-MgO-Si
O_Two, Al_TwoO_Three-CuO, Al_TwoO_Three-Fe_TwoO_Three,
Al_TwoO_Three-NiO, SiO_Two-MgO etc.
You. Note that the above formula expressed as an oxide is not a molecular formula,
Only the composition is shown. That is, in the present invention,
The structure and component ratio of the mixed oxides are not particularly limited.
It is not something to be done. The metal acid used in the present invention
Can absorb a small amount of water.
It may contain an amount of impurities.

As the metal chloride, for example, an alkali metal or alkaline earth metal chloride is preferable, and specifically, MgCl ₂ , CaCl _{2 and the} like are particularly preferable. As the metal carbonate, a carbonate of an alkali metal or an alkaline earth metal is preferable, and specific examples include magnesium carbonate, calcium carbonate, barium carbonate and the like. Examples of the carbonaceous substance include carbon black and activated carbon. Although any of the above inorganic carriers can be suitably used in the present invention, use of metal oxides such as silica and alumina is particularly preferable.

On the other hand, as the particulate polymer carrier, any of a thermoplastic resin and a thermosetting resin can be used as long as they maintain a solid state without melting or the like during catalyst preparation and polymerization reaction. The particle size is usually 5-2000μ
m, preferably in the range of 10 to 100 μm. The molecular weight of these polymer carriers is not particularly limited as long as the polymer can exist as a solid substance at the time of catalyst preparation and polymerization reaction.
It can be used arbitrarily from low molecular weight to ultra high molecular weight.

Specifically, various polyolefins (preferably having 2 to 12 carbon atoms) represented by particulate ethylene polymer, ethylene copolymer, propylene polymer or (co) polymer, poly 1-butene, etc. ), Polyester, polyamide, polyvinyl chloride, polymethyl (meth) acrylate, polystyrene, polynorbornene, various natural polymers, and mixtures thereof.

The above-mentioned inorganic carrier and / or particulate polymer carrier can be used as they are, but preferably these carriers are preliminarily treated with an organic aluminum compound or a modified organic aluminum compound containing an Al—O—Al bond. After the contact treatment, it can be used as the component (a5).

The method for producing the ethylene copolymer (B) of the present invention is produced by a gas phase method, a slurry method, a solution method or the like, and is not particularly limited, such as a one-stage polymerization method or a multi-stage polymerization method. It is desirable to manufacture by a gas phase method from the viewpoint of balance between cost and economy.

In the present invention, (A) 90 to 40% by weight of a low-density polyethylene obtained by a high-pressure radical polymerization method and (B) 10 to 60% by weight of an ethylene copolymer. ) 90 to 5 components
0% by weight, more preferably 90 to 60% by weight. (A) When the blending amount of the low-density polyethylene by the high-pressure radical polymerization method is less than 40% by weight, the moldability is poor and the wall thickness distribution becomes non-uniform, and (B) when the ethylene copolymer is less than 10% by weight, it is transparent. The properties are not improved.

The resin composition obtained by blending the components (A) and (B) has an MFR of 0.5 to 5 g / 10 min and a melt tension of 3 g or more. MFR is 0.5g / 10mi
If it is less than n, the fluidity is poor, and if it exceeds 5 g / 10 min, the drawdown property is poor. If the melt tension is less than 3 g, the drawdown property is inferior, and the thickness distribution becomes non-uniform during hollow molding.

The resin composition has a light transmittance (T _BD ) at a wavelength of 450 nm, which is higher than that of the components (A) and (B) before blending.
It must be superior to both of the light transmittances (T _A ) and (T _B ) of the components (T _BD > T _A and T _BD > T _B ). The light transmittance is obtained by placing a sample punched out of a 0.4 mm thick bottle formed by molding each component under constant conditions into a glass cell filled with pure water, and measuring the transmittance at a wavelength of 450 nm.

Further, the resin composition of the present invention is obtained by molding a 0.4 mm thick cylindrical container under a predetermined condition.
Light transmittance at 450 nm wavelength after retorting at 05 ° C (T
_BD ) is 60% or more and the wall thickness distribution is 0.55 or more, as a container for medical infusion, transparency after retort does not decrease and foreign matter inside can be easily distinguished. This is particularly preferable because the drop strength of the sample does not decrease.

The above relationship shows that the transparency is better when the components are mixed than when the components are used alone. If the light transmittance does not satisfy this relationship, the transparency is insufficient, and it is used for hollow molding where the thickness is thicker and the cooling rate is slower than the medical infusion container obtained by sheet, film molding, etc., and the transparency tends to decrease. It is not suitable as a composition.

The above-mentioned components are mixed with various polymers by various known methods, for example, a Henschel mixer, a V blender, a ribbon blender, a tumbler mixer, or the like, or after mixing, a single-screw extruder, a twin-screw extruder, or a kneader. After melt-kneading with a Banbury mixer or the like, granulation or pulverization may be employed.

The composition of the present invention may contain, if necessary, an antioxidant, a nucleating agent, a lubricant, an antistatic agent, a pigment, an antifogging agent as long as the properties of the present invention are not substantially impaired. Known additives such as an ultraviolet absorber, a flame retardant, and a dispersant can be added. Furthermore, other thermoplastic resins within a range that does not essentially impair the required properties of the present invention, such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene rubber, ethylene-propylene-diene rubber, and the like. It can be used by blending with a polyolefin.

The medical infusion container of the present invention is formed by hollow molding. The transparency does not decrease even by retort sterilization, and the drop strength is strong.

[0054]

EXAMPLES Next, specific examples of the present invention will be described.

(Resin used) (A) High pressure radical polymerization low density polyethylene A1: MFR 1.2 g / 10 min, density 0.929 g
/ Cm ³ , melt tension 12 g A2: MFR 1.0 g / 10 min, density 0.922 g
/ Cm ³ , melt tension 13g

(B) Production of Ethylene Copolymers (B1), (B2), (B5) and (B6) Preparation of Solid Catalyst Under nitrogen, 60 ml of purified toluene was added to a catalyst preparation device equipped with an electromagnetic induction stirrer, and then tetraethylene was added. 1.3 g of propoxyzirconium (Zr (OPr) ₄ ) and 1.9 g of indene
Was added, and 3.0 g of triethylaluminum was added dropwise while maintaining the system at 0 ° C. After completion of the dropwise addition, the reaction system
And stirred for 8 hours. Next, a toluene solution of methylaluminoxane (Al concentration: 4.5 wt%) was added to the reaction vessel.
280 ml was added, and the mixture was stirred at room temperature for 1 hour. This is designated as solution A. Next, silica (Fuji Devison, grade # 952, surface area 300) previously calcined at 400 ° C. for 5 hours was placed in another catalyst preparation device with an electromagnetic induction stirrer under nitrogen.
After adding 100 g of m ² / g), the whole amount of the solution A was added, followed by stirring at room temperature for 1 hour. Then, the solvent was removed by nitrogen blowing to obtain a solid catalyst powder having good fluidity. This is designated as catalyst B.

(Polymerization of Samples B1, B2, B5 and B6) Using a continuous fluidized bed gas phase polymerization apparatus, a polymerization temperature of 70 ° C.
Copolymerization of ethylene and 1-hexene was performed at a total pressure of 20 kgf / cm ² G. The polymerization was carried out by continuously supplying the catalyst B, and the polymerization was carried out while continuously supplying each gas in order to keep the gas composition in the system constant. The properties of the produced copolymer are shown in the separate table.

(Samples B3, B4) Linear low density polyethylene solution-polymerized with B3 Ziegler catalyst: MFR 2.0 g / 10 min, density 0.920
g / cm ³ , crystallization peak temperature 105.5 ° C. B4 metallocene LLDPE EXACT manufactured by Exxon
3025: MFR 2.0 g / 10 min, density 0.91
0 g / cm ³ , crystallization peak temperature 87 ° C

[0059]

[Table 1]

[Evaluation method] Melt tension: 190 ° C., extrusion speed 20 mm / min, using a melt tension tester manufactured by Toyo Seiki Co., Ltd.
Measured at a take-off speed of 15 m / min. Wall thickness distribution ID: A bottle is formed by the following method, the wall thickness of the bottle body excluding corners is measured in the axial direction and the circumferential direction, and the ratio of the minimum wall thickness to the maximum wall thickness is calculated as the wall thickness distribution. ID
And Wall thickness distribution ID = (minimum wall thickness of bottle) / (highest wall thickness of bottle) Bending stiffness: JIS based on 1.5 mm press sheet
The method of K7106 was followed. Tensile impact value: ASTM for bottle punched sample
The method of D1822 was followed. Pinch-off strength and elongation at break: Measured by punching sample from bottle pinch-off. Underwater transmittance: Put pure water in a glass cell, thickness 0.4
A sample punched out from the body of the bottle was inserted, and the transmittance at a wavelength of 450 nm was measured. Thermal deformation: The degree of deformation of the bottle after the retort treatment is visually judged in two stages.な し indicates no deformation and X indicates deformation. Drop strength: average thickness 0.4 mm, content 100
A flat container of 0 ml was molded, filled with 95% of water, and a sample that did not break when dropped from a height of 150 cm at an ambient temperature of 5 ° C. was rated as “O”, and a sample that broke and leaked liquid was rated as “X”.

[Formation of Bottle] Cylindrical bottle (body diameter 5.
(5 cm, body height 13 cm) was hollow-formed under the following molding conditions. Molding machine: Japan Steel Works, Ltd. Hollow molding machine JB105 (single-cavity mold, single head, with 50 mmφ extruder) Die diameter 14.0 mmφ, core diameter: 9.0 mmφ Screw rotation speed: 10 rpm Molding temperature: 180 ° C. Blowing air pressure: 4.0 kgf / cm ² Blowing time: 10 to 16 seconds Mold temperature: 30 ° C Average body thickness: 0.4 mm

Example 1 80% by weight of sample A1 and 20% by weight of sample B1 were uniformly stirred by a Henschel mixer for 1 minute and then melt-kneaded by a single screw extruder having a screw diameter of 50 mmφ and L / D25. The melt tension of the pellets was measured, and a sheet having a thickness of 1.5 mm was formed by press molding under the conditions of JIS K6760, and the bending stiffness was measured according to JIS K7106.

Next, a bottle having a capacity of 300 ml and a round cross section was formed at a set temperature of 180 ° C. using a JB105 blow molding machine manufactured by Japan Steel Works. The thickness distribution of the bottle was measured, and at the same time, the transmittance of light having a wavelength of 450 nm of a sample cut out to a size of 10 × 60 mm in water was measured. Further, retort treatment was performed at 105 ° C. and 110 ° C. for 30 minutes, and the degree of deformation of the bottle was observed. At the same time, the bottle was punched out, and the tensile impact strength, pinch-off strength and elongation at break in the MD and TD directions were measured. The results are shown in Table 1.

Example 2 The same procedure was carried out as in Example 1 except that sample A1 was 50% by weight and sample B1 was 50% by weight. The results are shown in Table 1.

Example 3 The same procedure as in Example 1 was carried out except that Sample A1 was 60% by weight and Sample B2 was 40% by weight. The results are shown in Table 1.

[Comparative Example 1] A sample A1 was used as the component A, and a sample B3, which was a Ziegler method LL, was used as the component B.
The same was done. The results are shown in the table. Poor transparency.

[Comparative Example 2] The same procedure as in Example 1 was carried out, except that Sample A2 having a low density was used as the component A and Sample B1 was used as the component B. The results are shown in the table. Transparency in retort sterilization is large and heat resistance is poor.

[Comparative Example 3] The same procedure as in Example 1 was carried out except that sample A1 was used as the component A and sample B4 was used as the component B. The results are shown in the table. Transparency in retort sterilization is large and heat resistance is poor.

[Comparative Example 4] The same procedure as in Example 1 was carried out using only the sample A1 as the component A and without using the component B. The results are shown in the table. Poor transparency. Further, although the thickness ID is good, the strength of the composition itself is weak, so that the drop strength is inferior.

Comparative Example 5 Sample A1 was used as an
The same procedure as in Example 1 was carried out except that B1 was 80% by weight as the B component and the B component. The results are shown in the table. The melt tension is low and the thickness distribution of the bottle is not uniform.

[Comparative Example 6] The same procedure as in Example 1 was performed using Sample B5 having a high MFR as the B component. The results are shown in the table. The melt tension is low and the thickness distribution of the bottle is not uniform.

[Comparative Example 7] The same procedure as in Example 1 was carried out using a high density sample B6 as the B component. The results are shown in the table.
Poor transparency.

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

[Brief description of the drawings]

FIG. 1 is a temperature-elution amount curve of the ethylene copolymer (B) used in the present invention.

Fig. 2 Temperature-elution curve of ethylene copolymer with single-site catalyst

Claims (3)

[Claims] (A) The MFR is 0.5 to 5 g / 10 mi.
n, 90 to 40% by weight of low-density polyethylene having a density of 0.925 to 0.935 g / cm ³ by high-pressure radical polymerization, and (B) ethylene copolymer satisfying the following conditions (a) to (e): Composed of 60 to 10% by weight, MFR 0.5 to
5 g / 10 min, melt tension of 3 g or more, and 450 g
The hollow molding characterized in that the light transmittance (T _BD ) at a wavelength of nm is higher than each of the light transmittances (T _A ) and (T _B ) of the components ( _A ) and ( _B ). A resin composition for medical infusion containers by the method. (A) Density 0.905 to 0.925 g / cm ³ (b) Melt flow rate (MFR) 0.5 to 10 g / 10 min (c) Elution temperature-elution amount curve by continuous heating elution fractionation method (TREF) There are multiple peaks, and the peak of the highest temperature exists at 90 ° C or higher. (D) The relationship between the crystallization temperature (Tc: ° C.) and the density (d: g / cm ³ ) by DSC is Tc ≦ 300d-172. 2. The ethylene copolymer (B) further comprises (e) a composition distribution parameter Cb of 1.08 to 2.00.
The resin composition for a medical infusion container according to claim 1, which satisfies the following condition: 3. A medical infusion container comprising the resin composition according to claim 1 or 2.