JP2019119814A - Propylene-based resin composition and molded body thereof - Google Patents

Abstract

To provide a propylene-based resin composition for blow molding good in moldability, and excellent in impact strength, transparency and heat deformation resistance, and a medical kit formulation using the same.SOLUTION: There is provided a propylene-based resin composition containing, based on overall weight of the composition, a propylene-ethylene random copolymer (A) satisfying requirements (A-i) to (A-iii) of 65 to 85 wt.%, and an ethylene-α-olefin random copolymer (B) satisfying requirements (B-i) to (B-iii) of 15 to 35 wt.%, and practically no crystallization nucleus agent, and being blow molded.SELECTED DRAWING: None

Description

  The present invention relates to a propylene-based resin composition which is excellent in moldability, transparency, impact strength, heat deformation resistance and is suitable for blow molding, and a medical kit preparation using the same.

  Conventionally, polyethylene, polypropylene, polyvinyl chloride and polyethylene terephthalate have been mainly used as resin blow molded articles. However, crystalline resins such as polyethylene and polypropylene are inferior in transparency and gloss, and are unsuitable for use in glass bottles. Moreover, polyvinyl chloride has problems in recycling and hygiene although it is excellent in transparency and glossiness, and heat shrinkage and hydrolyzability in comparison with polyethylene and polypropylene although polyethylene terephthalate has excellent transparency and glossiness. It was inferior to

On the other hand, in the case of beverage containers, high-temperature filling and hot warmers are required, and in food containers, application to microwave ovens and high-temperature filling are often performed, and heat resistance of the containers is required. In addition, medical containers are required to have heat resistance that can withstand steam sterilization. Especially in recent years, in order to comply with PIC / S (Pharmaceutical Assessment Agreement and Pharmaceutical Inspection Agreement and Pharmaceutical Inspection Co-operation Scheme (PIC / S)), sterilization of higher strength is required, and steam sterilization is required. In the prior art, it has been necessary to withstand sterilization temperatures of 121.degree. C. or higher, which are higher than conventional sterilization temperatures.
In addition, in the propylene-ethylene random copolymer, it is necessary to increase the ethylene content to increase the impact strength, but when the ethylene content is increased, the heat resistance is deteriorated with the decrease of the melting point. Become.

With regard to the improvement of these impact strengths, polypropylene-based thermoplastic elastomers have recently been used in various industrial fields since they have appropriate strength, and their applications in beverage food fields and medical fields are also increasing.
Among such thermoplastic elastomers, so-called block type TPO, which imparts a propylene-ethylene copolymer elastomer to crystalline polypropylene, is higher in productivity than a random copolymer type elastomer, and is also heat resistant. And mechanical strength (in particular, impact strength) and the like, and is widely used in recent years because of its features such as excellent strength.

However, in many cases, crystalline polypropylene and propylene-ethylene copolymer elastomer are phase-separated, the transparency is extremely bad, and its use is difficult in medical kit preparations that require transparency.
Therefore, if a polypropylene resin composition capable of suppressing thermal deformation during high temperature processing while being extremely excellent in transparency and excellent in impact strength is realized, it is recognized as industrially significant and thus various methods have been used. Suggestions for improvement have been made.

For example, in order to solve the deterioration of transparency, polypropylene or a propylene-ethylene copolymer having a low ethylene content, a propylene-ethylene copolymer elastomer having a relatively high ethylene content but having a relatively low ethylene content, The technique of polymerizing using a Natta type catalyst is disclosed (refer to patent documents 1, 2). However, the Ziegler-Natta catalyst produces many low crystallinity components due to the wide distribution of crystallinity, particularly in the case of a propylene-ethylene copolymer having a high ethylene content, since there are multiple types of active sites. Because of this, the bleed-out is severe, and the product has a problem of being sticky and cloudy.
Although there is also disclosed a method of increasing the intrinsic viscosity or molecular weight of the elastomer to a certain extent or more so as to suppress the formation of low molecular weight components to improve the method (see Patent Document 3), the Ziegler-Natta type catalyst is an elastomer. Even if the molecular weight of the polymer is increased, the inhibitory effect on the formation of the low crystalline component is small, the transparency is not sufficient, the improvement in stickiness and bleed out is still insufficient, and the molecular weight of the elastomer is high. Poor appearance called eye etc. is likely to occur, and extrusion molding properties deteriorate, so the use of organic peroxides in the granulation step increases oligomers, and the odor is significantly deteriorated. I have a problem.
On the other hand, methods of improving the transparency of the polypropylene resin composition by including a crystallization nucleating agent have also been proposed (see Patent Documents 4 and 5). On the other hand, the crystallization nucleating agent has many problems such as contamination of contents by bleeding and causing an offensive odor as a product.

  In addition, beverage food containers and medical containers need to be hygienic, and more specifically, they volatilize in the vapor phase of the container due to additive components and decomposition products of the additives that elute from the container into food and medicines. Although it is necessary to minimize the amount of low molecular weight substances to be produced, the prior art can not achieve a sufficient level, and further improvement has been sought.

Japanese Patent Application Laid-Open No. 63-159412 Japanese Patent Application Laid-Open No. 63-168414 JP-A-9-324022 JP, 2010-121126, A JP, 2012-46692, A

  An object of the present invention is to provide a propylene-based resin composition for blow molding, which has good moldability and is excellent in impact strength, transparency, and heat deformation resistance, and a medical kit preparation using the same.

  In order to solve the problems of the above-mentioned invention which can be said to be highly required and important in the field of polypropylene-based blow in the prior art represented by the prior art in the prior patent documents etc., the prior art is referred to However, various investigations and discussions are carried out on raw materials, polymerization catalysts or polymerization conditions and copolymer compositions, and blow molding conditions, and as a result, depending on the definition of the composition and characteristics obtained using a specific raw material, etc. When blow molding is performed using the propylene-based resin composition to be specified, a resin composition excellent in blow moldability, impact strength, heat deformation resistance, and excellent in transparency without containing a crystallization nucleating agent can be obtained. The present invention has been accomplished on the basis of these findings. Furthermore, low-elution "The 16th revision Japanese Pharmacopoeia General test 7.02 Plastic drug container test method 2 Standard of plastic water soluble injection container 2.1 Polyethylene or polypropylene aqueous injection container" (hereinafter referred to as Japan The inventors have found that molded articles satisfying all the test items of the pharmacopoeia test may be obtained, and have led to the invention of a resin composition which gives an excellent medical kit preparation.

That is, according to the first invention of the present invention, a propylene-ethylene random copolymer (A) satisfying the following requirements (Ai) to (A-iii) based on the total weight of the composition 65 to 85% by weight, containing 15 to 35% by weight of an ethylene-α-olefin random copolymer (B) satisfying the following requirements (Bi) to (B-iii) and substantially crystallized There is provided a propylene-based resin composition which is characterized by being blow molded without containing a nucleating agent.
(Ai) The melt flow rate measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kg is 1 to 20 g / 10 min.
(A-ii) that the ethylene content is 1 to 6% by weight.
(A-iii) The maximum crystal melting peak temperature observed in the range of 50 to 180 ° C. in differential scanning calorimetry is 135 ° C. or higher.
(B-i) It is an ethylene-α-olefin random copolymer polymerized with a metallocene catalyst.
(B-ii) that the melt flow rate measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg is 0.1 to 20 g / 10 min.
(B-iii) The density is 0.899 to 0.920 g / cm ³ .

  According to a second aspect of the present invention, there is provided the propylene-based resin composition according to the first aspect, wherein the propylene-based resin composition is a propylene-based resin composition for medical kit preparation.

  According to a third aspect of the present invention, there is provided a medical kit preparation having a layer comprising the propylene-based resin composition for medical kit preparation according to the second invention, and being produced by blow molding. Be done.

  According to a fourth aspect of the present invention, there is provided a medical kit preparation characterized in that the medical kit preparation according to the third invention is an infusion bag or an infusion bottle.

  According to a fifth aspect of the present invention, there is provided a medical kit preparation characterized in that the medical kit preparation according to the third and fourth inventions is ethylene oxide gas sterilization or high pressure steam sterilization. Ru.

  According to the present invention, when using a propylene-based resin composition specified by the composition and performance specifications obtained using a specific raw material, moldability is good, and impact strength, transparency, heat deformation resistance It is possible to obtain an excellent blow molding propylene-based resin composition and a medical kit preparation using the same, which is extremely valuable industrially.

  Hereinafter, the embodiments of the present invention will be described in detail, but the description of the configuration requirements described below is an example of the embodiment of the present invention, and the present invention is not limited to these contents.

1. Propylene-ethylene random copolymer (A)
(1) Basic Definition The propylene-ethylene random copolymer (A) used in the present invention is produced using a metallocene catalyst or a Ziegler catalyst.

(2) Ratio of propylene-ethylene random copolymer (A) occupied in propylene-based resin composition The ratio of propylene-ethylene random copolymer (A) occupied in propylene-based resin composition is the total weight of the composition Based on 65 to 85% by weight, preferably 70 to 85% by weight, more preferably 75 to 85% by weight. The impact strength of a propylene-type resin composition can fully be exhibited as the ratio of a propylene ethylene random copolymer (A) is 85 weight% or less. Moreover, the heat resistance as a propylene-type resin composition is favorable in the ratio of a propylene ethylene random copolymer (A) being 65 weight% or more.

(3) Requirement (Ai): Melt flow rate (MFR) of propylene-ethylene random copolymer (A)
The propylene-ethylene random copolymer (A) has a MFR of 0.1 to 20 g / 10 min, preferably 0 to 20 g, according to a method measured in accordance with JIS-K7210 (230 ° C., 2.16 kg load). It is 2 to 10 g / 10 minutes, more preferably 0.3 to 5 g / 10 minutes, and still more preferably 0.4 to 3 g / 10 minutes. When the MFR is 20 g / 10 min or less, the MFR as a propylene-based resin composition does not become too high, the container has sufficient impact strength, and uniform melt without insufficient melt tension at the time of blow molding. A thick molded article can be obtained, and when the MFR is 0.1 g / 10 min or more, the problem that the discharge pressure becomes too high at the time of blow molding and productivity decreases can be avoided.

(4) Requirement (A-ii): Ethylene Content of Propylene-Ethylene Random Copolymer (A) As the propylene-ethylene random copolymer (A), the ethylene content is 1 to 6% by weight, preferably Is 1.5 to 5.0% by weight, more preferably 2.0 to 4.5% by weight, and still more preferably 2.5 to 4.0% by weight. When the ethylene content is 6% by weight or less, the rigidity improvement effect as a propylene-based resin composition can be sufficiently obtained, the buckling strength as a container is not impaired, and deformation during heat treatment is caused. Hateful. Furthermore, since crystallization at the time of blow molding is fast, the molding time is short and the blow moldability is good. On the other hand, when the ethylene content is 1 weight or more, it is possible to sufficiently exhibit the impact strength and the transparency of the propylene-based resin composition.

(5) Requirement (A-iii): Maximum crystal melting peak temperature of propylene-ethylene random copolymer (A) As the propylene-ethylene random copolymer (A), it is 50 to 180 ° C. in differential scanning calorimetry The maximum crystal melting peak temperature observed in the range is 135 ° C. or higher, preferably 136 ° C. or higher, more preferably 137 ° C. or higher, and still more preferably 138 ° C. or higher. The heat resistance is sufficient at the time of steam sterilization as it is 135 degreeC or more, and a shape can be maintained as a product. The preferred upper limit is 170 ° C.

2. Method for Producing Propylene-Ethylene Random Copolymer (A) The propylene-ethylene random copolymer (A) used in the present invention can be obtained by polymerization using a Ziegler catalyst or a metallocene catalyst.

  As Ziegler catalysts, transition metal components such as titanium trichloride, titanium tetrachloride, titanium halide compounds such as trichloroethoxytitanium, contact products of the above-mentioned titanium halide compounds and magnesium compounds represented by magnesium halide, and alkyl aluminums Compound or two-component catalyst with an organometallic component such as a halide, hydride or alkoxide thereof, and an electron donative compound containing nitrogen, carbon, phosphorus, sulfur, oxygen, silicon, etc. added to the component 3 Component type catalysts are mentioned.

  As a metallocene catalyst, (i) a transition metal compound of the periodic table group 4 containing a ligand having a cyclopentadienyl skeleton (so-called metallocene compound) and (ii) a metallocene compound to form a stable ion state A catalyst comprising an activatable co-catalyst and, if necessary, (iii) an organoaluminum compound, any known catalyst can be used. The metallocene compound is preferably a bridged metallocene compound capable of stereoregular polymerization of propylene, and more preferably a bridged metallocene compound capable of isoregular polymerization of propylene.

  (I) As a metallocene compound, for example, JP-A-60-35007, JP-A-61-130314, JP-A-63-295607, JP-A-1-275609, JP-A-2-41303, JP-A Nos. 2-131488, JP-A-2-76887, JP-A-3-163088, JP-A-4-300887, JP-A-4-211694, JP-A-5-43616, JP-A-5-20903, JP-A-6. The compounds disclosed in JP-A-2-239914, JP-A-7-504934, and JP-A-8-85708 are preferably used.

  More specifically, methylenebis (2-methylindenyl) zirconium dichloride, ethylenebis (2-methylindenyl) zirconium dichloride, ethylene 1,2- (4-phenylindenyl) (2-methyl-4-phenyl) -4H-Azulenyl) zirconium dichloride, isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dichloride, isopropylidene (4-methylcyclopentadienyl) (3-t-butylindenyl) zirconium dichloride, dimethylsilylene (2- Methyl-4-tert-butyl-cyclopentadienyl) (3′-tert-butyl-5′-methyl-cyclopentadienyl) zirconium dichloride, dimethylsilylene bis (indenyl) zirconium dichloride, dimethylsilylene bis (4,5 6,7-Tetrahydroindenyl) zirconium dichloride, dimethylsilylene bis [1- (2-methyl-4-phenylindenyl)] zirconium dichloride, dimethylsilylene bis [1- (2-ethyl-4-phenylindenyl)] Zirconium dichloride, dimethylsilylene bis [4- (1-phenyl-3-methylindenyl)] zirconium dichloride, dimethylsilylene (fluorenyl) t-butylamidozirconium dichloride, methylphenylsilylene bis [1- (2-methyl-4, (1-Naphthyl) -indenyl) zirconium dichloride, dimethylsilylene bis [1- (2-methyl-4,5-benzoindenyl) zirconium dichloride, dimethylsilylene bis [1- (2-methyl-4-phenyl-) 4H-Azuleni ) Zirconium dichloride, dimethylsilylene bis [1- (2-ethyl-4- (4-chlorophenyl) -4H-azulenyl)] zirconium dichloride, dimethylsilylene bis [1- (2-ethyl-4-naphthyl-4H-azulenyl) ] Zirconium dichloride, diphenylsilylene bis [1- (2-methyl-4- (4-chlorophenyl) -4H-azulenyl)] zirconium dichloride, dimethylsilylene bis [1- (2-ethyl-4- (3-fluorobiphenyl) Ryl) -4H-azulenyl) zirconium dichloride, dimethylgermylene bis [1- (2-ethyl-4- (4-chlorophenyl) -4H-azulenyl)] zirconium dichloride, dimethylgermylene bis [1- (2-ethyl) -4-phenylindenyl)] zirconium di Zirconium compounds such as chloride can be exemplified.

  In the above, compounds in which zirconium is replaced by titanium or hafnium can be used as well. It is also preferable to use a mixture of a zirconium compound and a hafnium compound. The chloride can be replaced with another halogen compound, a hydrocarbon group such as methyl, isobutyl or benzyl, an amide group such as dimethylamide or diethylamide, an alkoxide group such as a methoxy group or phenoxy group, a hydride group or the like. Among these, metallocene compounds in which an indenyl group or azulenyl group is bridged by silicon or germyl are particularly preferable.

The metallocene compound may also be used by being supported on a carrier of an inorganic or organic compound. As the carrier, porous compounds of inorganic or organic compounds are preferable, and specifically, ion exchange layered silicate, zeolite, SiO ₂ , Al ₂ O ₃ , silica alumina, MgO, ZrO ₂ , TiO ₂ , B Organic compounds such as inorganic compounds such as ₂ O ₃ , CaO, ZnO, BaO, ThO ₂ , porous polyolefins, styrene / divinyl benzene copolymers, olefin / acrylic acid copolymers, etc., or mixtures thereof Be

  (R) As a cocatalyst which can react with a metallocene compound and be activated to a stable ionic state, an organoaluminum oxy compound (for example, an aluminoxane compound), an ion exchange layered silicate, a Lewis acid, a boron containing compound, an ionic compound And fluorine-containing organic compounds are preferably mentioned.

  (C) Examples of organoaluminum compounds include trialkylaluminums such as triethylaluminum, triisopropylaluminum and triisobutylaluminum, dialkylaluminum halides, alkylaluminum sesquihalides, alkylaluminum dihalides, alkylaluminum hydrides, organoaluminum alkoxides, etc. Preferably mentioned.

As a method for producing a propylene-ethylene random copolymer (A), a slurry method using an inert solvent, a solution method, a gas phase method substantially using no solvent, or a polymerization monomer in the presence of the above catalyst And a bulk polymerization method using as a solvent.
For example, in the case of slurry polymerization, it can be carried out in an inert hydrocarbon or liquid monomer such as n-butane, isobutane, n-pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, xylene, etc. . The polymerization temperature is usually −80 to 150 ° C., preferably 40 to 120 ° C. The polymerization pressure is preferably 1 to 60 atm (0.101 to 6.08 MPa), and adjustment of the molecular weight of the resulting propylene-ethylene random copolymer (A) is carried out with hydrogen or another known molecular weight modifier. be able to.
The polymerization is carried out in a continuous or batch reaction, and the conditions may be those generally used. Furthermore, the polymerization reaction may be carried out in one stage or in multiple stages.

3. Ethylene-α-olefin random copolymer (B)
(1) Basic Provisions (Requirements (Bi))
The ethylene-α-olefin random copolymer (B) used in the present invention is a metallocene-based ethylene-α-olefin random copolymer produced using a metallocene catalyst.

  The ethylene-α-olefin random copolymer (B) used in the present invention is a random copolymer elastomer of ethylene and an α-olefin having 3 or more and 20 or less carbon atoms. Specific examples of the α-olefin having 3 or more carbon atoms and 20 or less carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1 -Decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene and the like. These α-olefins can be used alone or in combination. Among these, in particular, propylene, 1-butene, 1-hexene and 1-octene are preferably used. Furthermore, when using it combining an alpha-olefin, it is preferable to combine a propylene and 1-butene. Details of the ethylene-α-olefin random copolymer are described below.

(2) Content ratio of ethylene-α-olefin random copolymer (B) The ratio of ethylene-α-olefin random copolymer (B) in the propylene resin composition is based on the total weight of the composition It is 15 to 35% by weight, preferably 20 to 30% by weight. When the proportion of the ethylene-α-olefin random copolymer (B) is 35% by weight or less, the heat resistance as a propylene-based resin composition is good. On the other hand, when the ratio of the ethylene-α-olefin random copolymer (B) is 15% by weight or more, it is possible to sufficiently exhibit impact strength and transparency as a propylene-based resin composition.
(3) Requirement (B-ii): Melt flow rate (MFR) of ethylene-α-olefin random copolymer (B)
The MFR at 230 ° C. of the ethylene-α-olefin random copolymer (B) is preferably 0.1 to 20 g / 10 minutes, more preferably 0.2 to 10 g / 10 minutes, still more preferably 0.5 to 8 g 10 minutes, most preferably 1 to 6 g / 10 minutes. Within this range, the mixing condition of the propylene-based resin composition and the ethylene-α-olefin random copolymer becomes good, the dispersion is improved, and a stable resin composition having stability and excellent transparency is obtained. be able to.
(4) Requirement (B-iii): density of ethylene-α-olefin random copolymer (B) The ethylene-α-olefin random copolymer (B) has a density of 0.899 to 0.920 g / cm ³ The ethylene-alpha-olefin random copolymer which is preferably 0.899-0.910 g / cm < ³ > is desirable. If the density is 0.899 g / cm ³ or more, the rigidity as the container can be maintained, and if the density is 0.920 g / cm ³ or less, the transparency as the container can be maintained. It becomes.
(5) Content of Structural Unit Derived from Ethylene The content of the structural unit derived from ethylene in the ethylene-α-olefin random copolymer (B) is preferably 50% by weight or more, more preferably 65 to 95% by weight Within the range, the use of one obtained by copolymerizing another α-olefin results in good impact strength. Examples of other α-olefins include propane, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-octene Decene etc. can be mentioned.
Specific examples of the ethylene-α-olefin random copolymer include ethylene-propylene copolymer, ethylene-1-butene random copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene and ethylene-4. -Methyl-1-pentene copolymer, ethylene-3-methyl-1-pentene copolymer, ethylene-1-heptene copolymer, ethylene-1-octene copolymer, ethylene-1-decene copolymer, etc. Can be mentioned.

  Such ethylene-α-olefin random copolymer (B) is produced by using ethylene stereoregular polymerization catalyst, polymerizing in the coexistence of ethylene and other α-olefins while achieving molecular weight adjustment. can do. Specifically, the ethylene-α-olefin random copolymer uses ethylene and propylene, 1-butene, and the like in processes such as a solution method and a high pressure method using a metallocene catalyst as a stereoregular polymerization catalyst of olefin. It can be produced by copolymerizing α-olefins such as 1-hexene, 4-methyl-1-pentene and 1-octene. When manufactured using a metallocene catalyst, (weight average molecular weight) / (number average molecular weight) can be small and density can be low.

Moreover, ethylene-alpha-olefin random copolymer (B) used for the propylene-type resin composition of this invention can be used 1 type or in combination of 2 or more types.
Such ethylene-α-olefin random copolymers (B) are commercially available as Harmolex series manufactured by Nippon Polyethylene Co., Ltd., Kernel series, Evolue series manufactured by Prime Polymer Co., Ltd., Sumitomo Chemical Co., Ltd. And the like.

  Furthermore, when the molecular weight distribution (Mw / Mn) of the ethylene-α-olefin random copolymer (B) is less than 3.5, the oligomer, the low molecular weight content is small, there is no stickiness, and the odor at the time of molding Since the amount of contamination of the release material which affects the occurrence, odor and odor of the molded product is reduced, it is possible to enhance the product value as a molded product.

4. Additional ingredients (additives)
In the propylene-based resin composition of the present invention, in order to add other properties such as oxidation resistance, the effects of the present invention are not impaired by using, as an additional component, a known additive used for polyolefin. Although it can be formulated within the range, it is necessary to select among these additives those which satisfy the requirements in the beverage food field and the medical field which is the application of the present invention, but in particular, the crystallization nucleating agent is eluted It is necessary not to include substantially from the viewpoint of

(1) Specific Examples of Additives As specific examples of the antioxidant, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate as a specific example of the phenolic antioxidant, 1, 1 , 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, pentaerythrityl-tetrakis [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxyl) Benzyl) benzene, 3,9-bis [2- {3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8 10-tetraoxaspiro [5,5] undecane, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid and the like can be mentioned.
Specific examples of phosphorus-based antioxidants include tris (mixed, mono and dinonyl phenyl phosphite), tris (2,4-di-t-butylphenyl) phosphite, 4,4'-butylidene bis (3- Methyl-6-t-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-di-tridecylphosphite-5-t-butylphenyl) butane, bis (2, 4-di-tert-butylphenyl) pentaerythritol-di-phosphite, tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylene diphosphonite, tetrakis (2,4-di-t) -Butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di- Or the like can be mentioned Sufaito.
Specific examples of sulfur-based antioxidants include di-stearyl-thio-di-propionate, di-myristyl-thio-di-propionate, pentaerythritol-tetrakis (3-lauryl-thio-propionate), etc. .

  Specific examples of the neutralizing agent include calcium stearate, zinc stearate, hydrotalcite, Mizukalac (trade name, manufactured by Mizusawa Chemical Industry Co., Ltd.) and the like.

  Specific examples of the hindered amine stabilizer include polycondensate of dimethyl borate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, tetrakis (1,2) 2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butane tetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, N, N- Bis (3-aminopropyl) ethylenediamine.2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5 -Triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-] Triazine- 2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {2,2,6,6-tetramethyl-4-piperidyl} imino], poly [(6- Morphorino-s-triazine-2,4-diyl) [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) Imino}] and the like.

5. Crystallization Nucleator The propylene-based resin composition of the present invention contains substantially no crystallization nucleating agent. Specifically, the content of the crystallization nucleating agent is a total of 100% by weight of the propylene-ethylene random copolymer (A) and the ethylene-α-olefin random copolymer (B) (this is 100 parts by weight. Should be less than 0.002 parts by weight, preferably 0 parts by weight. Generally, a nucleating agent is blended for the purpose of improving transparency, rigidity and forming cycle, but it has been confirmed that the amount of eluate increases and contaminates the contents. Furthermore, it was also confirmed that the product did not conform to the Japanese Pharmacopoeia. Therefore, the propylene-based resin composition of the present invention contains substantially no crystallization nucleating agent. Examples of crystallization nucleating agents include sorbitol-type nucleating agents (trade name: Gelol MD, manufactured by Shin Nippon Rika Co., Ltd.) and nonitol-type nucleating agents (trade name: Millad Co., Ltd .; Mirad NX 8000 J).

(2) Method of blending additives As a method of blending the above-mentioned additive components, a method in which the additive powder is directly premixed to the powder of the polymer obtained by the polymerization, and the mixture is melt-kneaded and mixed, The blend can be obtained by, for example, a method of blending a master batch. Examples of mixers or melt kneaders used for the above mechanical mixing or melt-kneading include Henschel mixer, super mixer, V blender, tumbler mixer, ribbon blender, Banbury mixer, kneader blender, Brabender plastograph, roll, single-shaft A screw extruder granulator, a twin screw extruder granulator, etc. can be mentioned. The melt-kneading temperature is generally 100 to 300 ° C., preferably 150 to 280 ° C., more preferably 180 to 250 ° C. The method for producing a propylene-based resin composition for biaxial stretch blow molding according to the present invention can be a method of forming a pellet-like composition by melt-kneading and pelletizing as described above. The propylene-based resin composition of the present invention comprises the propylene-ethylene random copolymer (A), the ethylene-α-olefin random copolymer (B), and, if necessary, each predetermined amount of the above-mentioned additive, the above-mentioned mixer It can obtain by carrying out the melt-kneading process in the temperature range of 180-250 degreeC with the said melt-kneading machine, after throwing in and mixing.

5. Blow Molded Body (1) Blow Molding Method A blow container for a propylene-based resin composition used in the present invention is produced by molding a container using the blow-molding machine for the propylene-based resin composition of the present invention produced as described above. It is obtained by
As a blow molding method to be used, a general direct blow molding method is preferable in which a mold is closed after extrusion of a cylindrical molten resin, and the mold is expanded by air pressure and cooled and solidified. As the blow molding conditions, a molding temperature of 120 to 250 ° C., a blowing pressure of ^{2 to} 10 kg / cm ² (0.196 to 0.981 MPa), and a blow ratio of 1.2 to 5.0 are preferable. Moreover, these moldings can be widely used not only in single layer extrusion but also in multilayer extrusion molding with various resins, but in the case of multilayers, since this application is for medical use, the propylene-ethylene random copolymer of the present invention It is preferable to use the polymer (A) in the innermost layer.

(2) Use of container As a use of a container which consists of a blow molding obtained from a propylene resin composition of the present invention, a container for medical use which can be used for a beverage container, a food container, medical care whole, for example, drinking water Containers, beverage containers such as soft drink containers, sports drink containers etc., soy sauce containers, sauce containers, food containers such as salad oil containers etc., eye wash liquid containers, nutrient containers, fluid food containers, diagnostic medicine containers, medical kit formulations etc. A medical container is mentioned and it can be used not only as a liquid but also as a solid container such as tablets and powders. Among these, heat resistance is required, and it exerts an effect on a container having high performance for transparency and hygiene. In addition, the application of the medical kit preparation includes infusion containers for intravenous injection of blood, Ringer's solution, purified water, etc. which are required to be compatible with the Japanese Pharmacopoeia, dosing containers such as liquid cold medicine, eye drops containers, eye wash containers Not only liquids, but also solid containers such as tablets and powders.

(3) Heat sterilization When used as a medical container, heat sterilization is usually performed after filling the contents. As a method of heat sterilization, a general-purpose steam sterilizer under pressure can be used, and any method such as a batch method, a continuous method, a shower method and the like may be used. The heat resistance required at this time varies depending on the sterilization method, and if boiling sterilization, the temperature is 100 ° C., and the temperature is 110 ° C. or 121 ° C. or more in a steam sterilizer under pressure. At this time, if the temperature is low, the sterilization effect is poor, and if the heating temperature can be generally increased, the heating time can be reduced, so the efficiency of the heat sterilization step can be increased and the production efficiency can be raised. Therefore, it is preferable that the propylene-based resin composition in the present invention has heat resistance of at least 100 ° C., and can cope with sterilization at preferably 110 ° C. or more, more preferably 121 ° C. or more.

In the following, in order to explain the present invention more specifically and clearly, the present invention will be described in comparison with the examples and comparative examples to demonstrate the rationality and significance of the requirements of the constitution of the present invention.
In addition, the evaluation method and resin which were used by the Example and the comparative example are as follows.

1. Physical property, evaluation method (1) Preparation of injection test piece for physical property evaluation The test piece for each physical property evaluation is created by injection molding method using injection molding machine of 80t of mold clamping force for resin pellet, Test piece before heat sterilization Were prepared by conditioning for 72 hours in a temperature-controlled room adjusted to room temperature 23 ± 5 ° C. and relative humidity 50 ± 5% after blow molding or press molding described later.
(2) Preparation of test pieces for Japanese Pharmacopoeia test 70 kg of resin pellets after melting for 7 minutes at a pressure of 0 kg / cm ² G (gauge pressure, the same shall apply hereinafter) (0 MPa G) using an electric press at a temperature of 230 ° C. It compressed for 3 minutes by the pressure of / cm < ² > G (6.86MPaG). Thereafter, the sample was quickly moved to a cooling press at 30 ° C., and was cooled for 3 minutes under a pressure of 120 kg / cm ² G (11.77 MPaG) to prepare a flat plate having a thickness of 0.5 mm and a surface area of 1200 cm ^{2 on} the front and back.
(3) MFR
Melt flow rate (MFR) was measured according to JIS K-7210-1999 (230 ° C., 2.16 kg load) using resin pellets.
(4) Flexural modulus After molding a test piece by injection molding and leaving it for 72 hours in a thermostatic chamber adjusted to room temperature 23 ± 5 ° C. and relative humidity 50 ± 5%, JIS K-7171 (ISO 178) Asked according to.
(5) 0 ° C. Charpy impact strength A test piece is formed by injection molding, and after forming for 72 hours in a constant temperature room adjusted to room temperature 23 ± 5 ° C. and relative humidity 50 ± 5%, a 0 ° C. constant temperature bath The condition was adjusted for 1 hour, and determined in accordance with JIS K-7111.
(6) Transparency (Haze)
After molding an ISO flat plate with a thickness of 1 mm by injection molding and leaving it for 72 hours in a thermostatic chamber adjusted to room temperature 23 ± 5 ° C. and relative humidity 50 ± 5%, JIS K-7136 (ISO 14782) JIS K It asked according to -7361-1.
(7) Differential scanning calorimetry (DSC)
Using a differential scanning calorimeter (DSC), take a 5.0 mg sample amount from the resin pellet, raise the temperature to 200 ° C. once to erase the heat history, and hold at 200 ° C. for 5 minutes, then 10 ° C./min The temperature of the endothermic peak top observed in the range of 50 to 180 ° C. when the temperature is lowered to 40 ° C. to cause crystallization and the melting rate is measured again at a temperature rising rate of 10 ° C./min. As the maximum crystal melting peak temperature (melting point) (Tm).
(8) Blow moldability evaluation A molding temperature 200 using a small direct blow molding machine Model JB105 made by Japan Steel Works, Ltd. with a screw and die of L / D 22 having a diameter of 50 mmφ and L / D 22 with a dullage kneading portion at the tip. C., blow mold cooling temperature 15.degree. C., cooling time 24 seconds conditions: a flat 550cc bottle with an inner capacity of 30 g is formed, and the ratio of the upper thickness to the lower thickness of the molded body is 0.8-1. The thing of 0 was made good, and the thing of less than 0.8 or the thing which is a molding defect or a non-mold was made into defect.

(9) Heat resistance evaluation of 121 ° C. The sample container obtained in the above (8) was filled with 500 ml of water, and a sheet of 0.5 mm in thickness which was thermally compressed in advance with the same material as this sample container was heated to about 200 ° C. Heat sealed at a pressure of 2 kg for 30 seconds with a butt welding machine. Subsequently, the sample container was placed in a stainless steel autoclave type steam sterilizer having an inner volume of 100 L and heated at a temperature of 121 ° C. for 30 minutes, cooled to normal temperature and taken out, and the state of the container was determined.
○: No deformation was observed compared to before the test.
Δ: Some occurrence of deformation is recognized.
×: occurrence of significant deformation is recognized.
(10) 16th Revision Japanese Pharmacopoeia General Examination (Japanese Pharmacopoeia Examination):
According to the test method of the Japanese Pharmacopoeia "7.02 plastic drug container test method 2 standard of plastic water soluble injection container, 2.1 polyethylene or polypropylene water injection container", the ashing test and the eluted product The trial was evaluated.
However, as a sample used for the test, a flat plate of 0.5 mm thick prepared in (2) and having a surface area of 1200 cm ^{2 on} the front and back was used, and the ashing test was used by cutting 5 g of the flat plate. The elution test was conducted using a 0.5 mm thick plate having 1200 cm ² of front and back surface area, shredded to about 5 cm long and about 0.5 cm wide, washed with water, and dried at room temperature. Put this in a hard glass container with an internal volume of about 300 ml, add exactly 200 ml of water, seal with a suitable stopper, heat at 121 ° C. for 1 hour using a high-pressure steam sterilizer, and reach room temperature The mixture was left to stand, this internal solution was used as a test solution, and a blank test solution was separately prepared for water separately in the same manner. And, the Japanese Pharmacopoeia 2.1 was evaluated as conforming if it complies with all the specifications of the polyethylene or polypropylene aqueous injection container, and as nonconforming if any one item is nonconforming.

2. Materials Used Propylene-Ethylene Random Copolymer (A)
(A-1)
Ziegler-based propylene-ethylene random copolymer "Nippon Polypro Co., Ltd."; trade name Novatec PP EG8Q
The MFR (230 ° C., 2.16 kg load) is 0.8 g / 10 min, the ethylene content is 3.3% by weight, and the maximum crystal melting peak temperature is 140 ° C.
(A-2)
Metallocene propylene-ethylene random copolymer "Nippon Polypro Co., Ltd."; trade name Wintec WFX6Q
The MFR (230 ° C., 2.16 kg load) is 2.0 g / 10 min, the ethylene content is 3.2% by weight, and the maximum crystal melting peak temperature is 125 ° C.
(A-3)
Ziegler-based propylene-ethylene random copolymer "Nippon Polypro Co., Ltd. product; trade name Novatec PP MG03BQ"
The MFR (230 ° C., 2.16 kg load) is 30 g / 10 min, the ethylene content is 2.2 wt%, and the maximum crystal melting peak temperature is 154 ° C.

Ethylene-α-olefin random copolymer (B)
(B-1)
Metallocene ethylene-α-olefin copolymer “Nippon Polyethylene Co., Ltd.”;
Product Name Kernel KS261 "
The MFR (230 ° C., 2.16 kg load) is 4 g / 10 min, and the density is 0.900 g / cm ³ .
(B-2)
Metallocene ethylene-α-olefin copolymer “Nippon Polyethylene Co., Ltd.”;
Product Name Kernel KF 283 "
The MFR (230 ° C., 2.16 kg load) is 5 g / 10 min, and the density is 0.921 g / cm ³ .
(B-3)
Metallocene ethylene-α-olefin copolymer “Nippon Polyethylene Co., Ltd.”;
Product Name Kernel KS240T "
The MFR (230 ° C., 2.16 kg load) is 4 g / 10 min, and the density is 0.880 g / cm ³ .
(B-4)
Metallocene ethylene-α-olefin copolymer “Nippon Polyethylene Co., Ltd.”;
Product Name Kernel KS572 "
The MFR (230 ° C., 2.16 kg load) is 40 g / 10 min, and the density is 0.907 g / cm ³ .
(C-1)
Phenolic antioxidant "BASF company; trade name Irganox 1076"
(C-2)
Phosphorus-based antioxidant "made by BASF; trade name Irgafos 168"
(C-3)
Neutralizer "Kyowa Chemical Industry Co., Ltd. product name: DHT-4A"
(C-4)
Crystallization nucleating agent "Miriken & Co., Ltd. product name; Mirad NX 8000 J"

(Examples 1 to 3, Comparative Examples 1 to 9)
The compounding ratio as described in Table 1 is prepared, and specifically, a total of 100% by weight of a propylene-ethylene random copolymer (A) and an ethylene-α-olefin random copolymer (B) (100 parts by weight Of the additives to be formulated are weighed in parts by weight, and then dry blended for 3 minutes with a super mixer, using a 35 mm ° twin screw extruder, temperature 200 ° C., screw rotation speed 200 rpm, extrusion amount about 15 kg / hr The sample supply hopper was melt-kneaded under the condition of nitrogen atmosphere to obtain pellets of a propylene-based resin composition. Physical properties and evaluation results are shown in Table 1.

From Table 1, it is excellent in impact resistance, transparency, blow moldability, and 121 ° C heat resistance in Examples 1 to 3 which are the new propylene resin composition of the present invention which satisfies each prescription in the composition of the present invention. And, it is clear that it conforms to the Japanese Pharmacopoeia.
On the other hand, Comparative Example 1 is inferior in impact resistance because it does not contain the ethylene-α-olefin random copolymer (B). In Comparative Example 2, it is found that the blending amount of the ethylene-α-olefin random copolymer (B) is small and the impact resistance is inferior. In Comparative Example 3, it can be seen that the blending amount of the ethylene-α-olefin random copolymer (B) is large, the container becomes too soft and the heat resistance at 121 ° C. is inferior. It is understood that Comparative Example 4 is inferior in transparency because the density of the ethylene-α-olefin random copolymer (B) is high. In Comparative Example 5, since the density of the ethylene-α-olefin random copolymer (B) is low, it is understood that the transparency is poor. In Comparative Example 6, since the MFR of the ethylene-α-olefin random copolymer (B) is high, it is understood that the transparency is inferior. In Comparative Example 7, since the melting peak temperature of the propylene-ethylene random copolymer (A) is low, it is understood that the heat resistance is inferior at 121 ° C. In Comparative Example 8, since the MFR of the propylene-ethylene random copolymer (A) is high, it is understood that the blow moldability is inferior. In Comparative Example 9, since the crystallization nucleating agent is formulated, it is understood that although the transparency is excellent and the physical property balance is good, it does not conform to the Japanese Pharmacopoeia.

Claims (5)

Based on the total weight of the composition, 65 to 85% by weight of a propylene-ethylene random copolymer (A) satisfying the following requirements (Ai) to (A-iii), the following requirements (Bi ) Characterized by containing 15 to 35% by weight of the ethylene-α-olefin random copolymer (B) satisfying (1) to (B-iii) and containing substantially no crystallization nucleating agent and blow molding Propylene-based resin composition.
(Ai) The melt flow rate measured under the conditions of a temperature of 230 ° C. and a load of 2.16 kg being 0.1 to 20 g / 10 min.
(A-ii) that the ethylene content is 1 to 6% by weight.
(A-iii) The maximum crystal melting peak temperature observed in the range of 50 to 180 ° C. in differential scanning calorimetry is 135 ° C. or higher.
(B-i) It is an ethylene-α-olefin random copolymer polymerized with a metallocene catalyst.
(B-ii) that the melt flow rate measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg is 0.1 to 20 g / 10 min.
(B-iii) The density is 0.899 to 0.920 g / cm ³ .   The propylene-based resin composition according to claim 1, wherein the propylene-based resin composition is a propylene-based resin composition for medical kit preparation.   The medical kit formulation which has a layer which consists of a propylene-type resin composition for medical kit formulation of Claim 2, and is manufactured by blow molding.   The medical kit preparation according to claim 3, wherein the medical kit preparation is an infusion bag or an infusion bottle.   The medical kit preparation according to claim 3 or 4, wherein the medical kit preparation is ethylene oxide gas sterilization or high-pressure steam sterilization.