JP3404107B2 - Injection molding resin and injection molding resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has good moldability such as spiral flow, excellent transparency, excellent impact strength and tensile strength at room temperature or low temperature, and good heat resistance. The present invention relates to a resin composition suitable for an injection molded article having a good balance of rigidity.

[0002]

2. Description of the Related Art Materials conventionally used for food containers made of flexible resin such as Tupperware (registered trademark) include high-density polyethylene, polypropylene, high-pressure low-density polyethylene, and linear low-density polyethylene. To be High-density polyethylene has the drawback of poor flexibility and transparency. If the transparency is poor, the contents in the container may not be visible or may be difficult to see, which may reduce the commercial value of the product or limit its use.

On the other hand, polypropylene has relatively good transparency and good mechanical properties at room temperature, but its strength at low temperature is insufficient, so that it can be cracked or cracked when a local stress is applied to it in frozen storage applications. There was a drawback that whitening was likely to occur. In addition, due to lack of flexibility, there are drawbacks such as white streaks remaining when the container is greatly bent, and it is difficult to return to the original shape.

Although high-pressure low-density polyethylene has relatively good transparency, it cannot be used in applications such as microwave ovens because it does not have heat resistance, and it has environmental resistance (stress) cracking (ESCR). However, it is not good, and there is a problem that the use is limited because it is not suitable for fields requiring acid resistance, base resistance and oil / chemical resistance.

Linear low-density polyethylene has been introduced as a resin that solves the problems of these resins, but again, the transparency cannot reach the level required by the market, and the flexibility is poor. It was

[0006]

DISCLOSURE OF THE INVENTION The present invention has good moldability such as spiral flow, and has excellent transparency and excellent impact strength and tensile strength at room temperature or low temperature, while having good heat resistance. It is an object of the present invention to provide a resin composition suitable for an injection-molded article having a good balance of strength and rigidity.

[0007]

Means for Solving the Problems [Outline of the Invention] As a result of intensive studies to solve the above problems, the present inventors have found that a specific ethylene / α-olefin copolymer and
The inventors have found that the above objects can be achieved by using a resin composition composed of high-pressure low-density polyethylene , and completed the present invention.

Namely, the flexibility first invention of the present application is characterized in that it consists of components A and B shown below
It is a resin composition for resin food container injection molding. Component A: Copolymer of ethylene having the properties (a) to (c) shown below and an α-olefin having 4 or more carbon atoms.
50 to 95% by weight (a) MFR (190 ° C, 2.16 kg load) is 10
˜120 g / 10 min (b) Density is 0.915 g / cm ³ or less (c) There is one peak in the elution curve obtained by temperature rising elution fractionation (TREF), and the peak temperature is 85
Component B having a temperature of not higher than ° C: high having the properties (a) to (c) shown below
Pressure method low density polyethylene 5 to 50 wt% (a) MFR (190 ° C, 2.16 kg load) is 1 to
50 g / 10 min (b) Density 0.915 to 0.93 g / cm ³ (c) ME (3 g) 1.3 or more

The second invention of the present application is based on the first invention.
Haze of 70% or more obtained by injection molding the composition of Ming
Below, the bending elastic modulus is 1500 kgf / cm ² or less
It is a molded product.

[Detailed Description of the Invention] [I] Constituent (1) Copolymer of ethylene and α-olefin having 4 or more carbon atoms (a) Properties In the present invention , specifically, the above-mentioned first invention. Injection related to
Molding resin and resin composition for injection molding according to the second invention
Component A of the product is a copolymer of ethylene and an α-olefin having 4 or more carbon atoms (hereinafter, this copolymer is used in the present invention.
Of ethylene and α-olefins with 4 or more carbon atoms
"Coalition". ) Of, have use properties of ~ below, those preferably further having the properties of.

MFR The MFR (melt flow rate: melt flow rate, 190 ° C., 2.16 kg load) according to JIS-K7210 of the copolymer of ethylene and α-olefin having 4 or more carbon atoms used in the present invention is 10 to 12
0 g / 10 minutes, particularly preferably 10-100 g / 10
Min, most preferably 10 to 70 g / 10 min, particularly preferably 30 to 70 g / 10 min. If the MFR is too high, the strength decreases, which is not preferable. Further, if the MFR is too low, molding becomes difficult, which is not preferable.

Density The density according to JIS-K7112 of the copolymer of ethylene and α-olefin having 4 or more carbon atoms used in the present invention is
0.915 g / cm ³ or less, preferably 0.860 to
0.912 g / cm ³ , particularly preferably 0.870 to
It is 0.910 g / cm ³ . If the density is too high, the transparency is lowered and the flexibility is lowered, which is not preferable. On the other hand, if it is too low, a sticky component is increased on the surface of a molded product, which is not preferable.

Measurement of elution curve by temperature rising elution fractionation Temperature rising elution fractionation
Ionation: TREF) is based on "Journal of A
pplied Pollymer Science. Vol.26, 4217-4231 (198
1) "and" Proceedings of the Macromolecular Forum 2P1C09 (1985) "
It is performed as follows based on the principle described in. First, the polymer to be measured is completely melted in a solvent. Then, it is cooled to form a thin polymer layer on the surface of the inert carrier. In such a polymer layer, the one that is easily crystallized is formed on the inside (the side close to the surface of the inert carrier), and the one that is difficult to crystallize is formed on the outside. Next, when the temperature is raised continuously or stepwise, in the low temperature stage, the amorphous portion in the target polymer composition, that is, the one having a large degree of branching of short chain branches possessed by the polymer, is eluted, and the temperature gradually rises. Those with a low degree of branching elute, and finally the straight-chain portion without branching elutes and the measurement ends. It is possible to detect the concentration of the elution component at each temperature and to see the compositional distribution of the polymer from the graph drawn by the elution amount and the elution temperature.

The copolymer of ethylene and the α-olefin having 4 or more carbon atoms used in the present invention has a temperature rising elution fraction (T
Peak of the elution curve obtained by REF) is Mashimashi one exist, and the peak temperature is 85 ° C. or less, preferably 75 ° C.
The temperature is particularly preferably 60 ° C. or lower. If the peak temperature exceeds 85 ° C., flexibility, since transparency is deteriorated unfavorably.

Elution amount at 40 ° C. by temperature rising elution fractionation The copolymer of ethylene and α-olefin having 4 or more carbon atoms used in the present invention is an elution amount at 40 ° C. by temperature rising elution fractionation (TREF) (Y: % By weight based on the total amount of the copolymer of ethylene and an α-olefin having 4 or more carbon atoms) is preferable to satisfy the following conditions. That is, Y ≦ −3600D + 3304 (D: density of copolymer of ethylene and α-olefin having 4 or more carbon atoms, where Y ≦ 100), preferably Y ≦ −3800.
It is D + 3482 (however, Y <= 100). If it is out of the above range, bleed-out tends to occur on the surface of the product, which is a problem in terms of food hygiene of the product, which is not preferable.

Haze The copolymer of ethylene and α-olefin having 4 or more carbon atoms used in the present invention is an injection-molded sheet (thickness: 2 mm).
It is preferable that the haze measured according to JIS-K7105 is as follows. You
That is, it is 70% or less, preferably 50% or less, particularly preferably 40% or less, and most preferably 30%.

Flexural Modulus The copolymer of ethylene and α-olefin having 4 or more carbon atoms used in the present invention preferably has the following flexural modulus measured according to JIS-K7203.
That is, 1500 kgf / cm ² or less, preferably 1
200 kgf / cm ² hereinafter, particularly preferably 1000k
gf / cm ² or less. Flexural modulus undesirable to the effect that less flexible when Ru exceed <br/> the above range.

(B) Production of Copolymer of Ethylene and α-Olefin Having 4 or More Carbons The method for producing the copolymer of ethylene and α-olefin having 4 or more carbons used in the present invention is described in JP-A-2000-187. 58-19309
No. 59-95292, No. 60-35005, No. 60-35006, No. 60-35007, No. 60-.
No. 35008, No. 60-35009, No. 61-130
No. 314, JP-A-3-163088, European Patent Application Publication No. 420436, US Pat. No. 5,055,438, and International Publication WO 91/0.
4257 and the like. That is, ethylene used in the present invention and α- having 4 or more carbon atoms
The method for producing a copolymer with an olefin is a metallocene catalyst,
In particular, using a metallocene alumoxane catalyst, or a catalyst composed of a compound that reacts with a metallocene compound as described below and a metallocene compound described below to form a stable ion, for example, as disclosed in International Publication WO92 / 04257, It is a method of copolymerizing ethylene as a main component and an α-olefin having a carbon number of 4 or more as a subsidiary component.

The compound that reacts with the metallocene compound to form a stable ion is an ionic compound or an electrophilic compound formed from an ion pair of a cation and an anion, and reacts with the metallocene compound to provide a stable ion. To form polymerization active species.

Of these, the ionic compound is represented by the following formula [I]. [I] [Q] _m [Y] _m- (m is an integer of 1 or more) Q is a cation component of an ionic compound, and is a carbonium cation, tropylium cation, ammonium cation, oxonium cation, sulfonium cation,
Examples thereof include phosphonium cations, and further examples include metal cations and organometallic cations, which are themselves easily reduced. These cations are listed in Special Table 1-50
Not only a cation capable of giving a proton as disclosed in Japanese Patent No. 1950, but also a cation not giving a proton may be used. Specific examples of these cations include triphenyl carbonium, diphenyl carbonium, cycloheptatrienium, indenium,
Triethylammonium, tripropylammonium,
Tributylammonium, N, N-dimethylanilinium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium, tri (dimethylphenyl) phosphonium, tri (methylphenyl) phosphonium, triphenylsulfonium, triphenyloxonium, triethyloxo Examples of the ion include nickel, pyrylium, silver ion, gold ion, platinum ion, palladium ion, mercury ion, and ferrocenium ion.

Y is an anion component of an ionic compound, which is a component that reacts with a metallocene compound to form a stable ion, and is an organic boron compound anion, an organic aluminum compound anion, an organic gallium compound anion, an organic phosphorus compound. Examples thereof include anions, organic arsenic compound anions, organic antimony compound anions, and specific examples include tetraphenylboron and tetrakis (3,4,4).
5-trifluorophenyl) boron, tetrakis (3,3
5-di (trifluoromethyl) phenyl) boron, tetrakis (3,5- (t-butyl) phenyl) boron, tetrakis (pentafluorophenyl) boron, tetraphenylaluminum, tetrakis (3,4,5-trifluorophenyl) ) Aluminum, tetrakis (3,5-
Di (trifluoromethyl) phenyl) aluminum, tetrakis (3,5-di (t-butyl) phenyl) aluminum, tetrakis (pentafluorophenyl) aluminum, tetraphenylgallium, tetrakis (3,3)
4,5-trifluorophenyl) gallium, tetrakis (3,5-di (trifluoromethyl) phenyl) gallium, tetrakis (3,5-di (t-butyl) phenyl)
Gallium, tetrakis (pentafluorophenyl) gallium, tetraphenyl phosphorus, tetrakis (pentafluorophenyl) phosphorus, tetraphenyl arsenic, tetrakis (pentafluorophenyl) arsenic, tetraphenyl antimony, tetrakis (pentafluorophenyl) antimony, decaborate, undeca Examples thereof include borate, carbadodecaborate and decachlorodecaborate.

The electrophilic compound, which is known as a Lewis acid compound, is a compound which reacts with a metallocene compound to form stable ions to form a polymerization active species. Examples thereof include metal oxides known as solid acids. Specific examples include magnesium halides and Lewis acidic inorganic oxides.

Α-Olefin Here, the α-olefin is an α-olefin having 4 or more carbon atoms, for example, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 4-methylpentene-. 1,4-methylhexene-1,4,4-dimethylpentene-1 and the like can be mentioned. Among these α-olefins, the number of carbon atoms is preferably 4 to 12, and particularly preferably 6 to 1
0 to 1 or 2 or more α-olefins 2 to 60% by weight, preferably 5 to 50% by weight, particularly preferably 10 to
It is preferred to copolymerize 30% by weight with 40 to 98% by weight of ethylene, preferably 50 to 95% by weight, particularly preferably 70 to 90% by weight.

Examples of the copolymerization polymerization method include a gas phase method, a slurry method, a solution method and a high pressure ionic polymerization method. Among these, the solution method and the high-pressure ionic polymerization method are preferable, and the high-pressure ionic polymerization method is particularly preferable. The high pressure ionic polymerization method is described in JP-A-56-18607 and JP-A-58-225106, and the pressure is 100 kg / cm ² or more, preferably 300 to 20.
00 kg / cm ² , temperature is 125 ° C. or higher, preferably 1
It is a method for producing an ethylene polymer which is carried out under reaction conditions of 30 to 250 ° C, particularly 150 to 200 ° C.

[0025] (2) polymers of component B of the injection molding resin composition for injection molding a resin composition blended resin for the present invention is a high-pressure low-density polyethylene obtained by high-pressure polymerization processes
There is . Moreover, below, the resin may be a 併.

High-pressure low-density polyethylene High-pressure low-density polyethylene when a high-pressure low-density polyethylene is blended with a copolymer of ethylene and an α-olefin having 4 or more carbon atoms to prepare a resin composition for injection molding.
(Component B) has the following properties (a) to (c)
Further, it is desirable to use those having properties (d) to (e) .

(A) MFR MFR according to JIS-K7210 (melt flow rate: Melt Flowrate: melt flow rate, 190)
It is desirable that the material has a physical property of 1 to 50 g / 10 minutes, particularly preferably 10 to 50 g / 10 minutes at a temperature of 2.16 kg. If the MFR is too high, the strength decreases, which is not preferable. Further, if the MFR is too low, it becomes difficult to mix with the component A, which is not preferable.

(B) Density The density according to JIS-K7112 is 0.915 to 0.9.
3 g / cm ³ , preferably 0.918 to 0.927 g /
cm ³ , particularly preferably 0.919 to 0.923 g / c
It is desirable that the physical properties of m ³ are exhibited. When the density is too high, the transparency is deteriorated, which is not preferable. On the other hand, if it is too low, a sticky component is increased on the surface of a molded product, which is not preferable.

(C) ME (Memory Effect): ME (3 g) (Memory Effect) is 1.3.
It is desirable that the above-mentioned physical properties are preferably 1.6 or more, and particularly preferably 1.8 or more. If the ME is smaller than the above value, the effect of improving the moldability is small, which is not preferable. The measurement of the ME (3 g) is performed according to JIS-K7.
The melt indexer used in No. 210 is used, the measurement conditions are set to a cylinder temperature of 240 ° C. and a constant rate extrusion rate of 3 g / min. The device is filled with the sample, only the piston is placed and after 6 minutes the prescribed extrusion rate is applied. Next, a graduated cylinder containing ethyl alcohol is placed immediately below the orifice, and a straight extrudate is collected. The diameter (D) of the sampled extrudate is measured with a micrometer, and the orifice diameter of the die is D ₀ , and ME is calculated by the following equation. ME = D / D ₀

(D) Q value The high-pressure method low-density polyethylene has a Q value (weight average molecular weight / number average molecular weight) of 5 or more, preferably 7 or more, which is determined by size exclusion chromatography (SEC). , Particularly preferably 9
Those having the above physical properties are preferable. If the Q value is too low, the effect of improving the moldability is small, which is not preferable.

(E) Activation energy (Ea) The activation energy (Ea) when the shear rate obtained from the viscosity of the high-pressure low-density polyethylene is 24 sec ^-1 is 5 KJ / mol or more, preferably Is 8 KJ / mol or more, particularly preferably 12 KJ / mol or more. When the activation energy is small, the effect of improving the spiral flow is small, which is not preferable. This activation energy is "rheology" (Misuzu Publishing, Tsurutaro Nakagawa, Hirotaro Kobe 604
Page), "Kodansha Contemporary Science Series 18 Rheology"
(Kodansha, Shizuo Hayashi, pp. 160-161) and other documents that describe the relationship between viscosity and temperature.
The activation energy is calculated from the enius formula or the Andrade formula. In particular,
The measurement temperature is 160 ° C with a capillograph type viscosity measuring device.
(433k), 190 ° C (463k), 230 ° C (50
3k), and the shear viscosity (η) at a shear rate of 24 sec ⁻¹ is determined from the viscosity curve (viscosity dependence curve for shear rate) measured at each temperature. Next, the intercept: logA is obtained from a graph in which 1 / T (T = measured temperature: k) is on the horizontal axis and log η is on the vertical axis. Substituting each obtained value into the following equation,
Calculate the activation energy (Ea). η = Ae ^{−Ea / RT} → log η = log A−Ea / RT (η: shear viscosity (poise), A: frequency factor, Ea: activation energy (KJ / mol), R: gas constant (8.3145J / K · mol),
T: Absolute temperature (k))

(F) Specific Examples of High-Pressure Low-Density Polyethylene The high-pressure low-density polyethylene may be appropriately selected from commercial products having the above-mentioned physical properties.

Propylene-based polymer Copolymer of ethylene and α-olefin having 4 or more carbon atoms (component A) and high-pressure low-density polyethylene (component)
When the propylene-based polymer is blended with B) to prepare a resin composition for injection molding, the propylene-based polymer is a homopolymer of propylene or a random or block copolymer of propylene and a small amount of α-olefin. . The production method is not particularly limited, and generally, a Ziegler-Natta catalyst used in combination with a so-called titanium-containing solid transition metal component and an organic component, in particular, the transition metal component essentially requires titanium, magnesium and halogen. As a component, using a catalyst having an electron donating compound as an optional component, a solid component or titanium trichloride, and an organometallic component being an organoaluminum compound, slurry polymerization, gas phase polymerization, bulk polymerization, solution polymerization, or the like, or In a polymerization method in which these are combined, a propylene homopolymer obtained by homopolymerizing propylene in a single stage or multiple stages, or propylene and an α-olefin having 2 or 4 to 12 carbon atoms, preferably ethylene, in a single stage or multiple stages It is a propylene / ethylene copolymer obtained by copolymerization with. The propylene-based polymer may be a random polymer or a block polymer, but is preferably a block polymer. Two or more kinds of these propylene-based polymers may be used. The propylene-based polymer,
It preferably has the following properties.

(A) MFR JIS-K7210 (230) of the propylene polymer.
CFR, 2.16kg load) MFR is 1-100g /
It is 10 minutes, preferably 5 to 50 g / 10 minutes, particularly preferably 10 to 40 g / 10 minutes. If the MFR is too high, the strength decreases, which is not preferable. Further, if the MFR is too low, the spiral flow is deteriorated, which is not preferable.

(B) Activation energy (Ea) Shear rate (Sh calculated from the viscosity of the propylene polymer
ear rate) is 24 sec ^-1Activation energy (E
a) is 8 KJ / mol or more, preferably 10 KJ / mol or more,
It is preferably 12 KJ / mol or more. The activation energy
If the value is too small, the effect of improving spiral flow is small and it is preferable.
Not good. The activation energy is measured by measuring the viscosity.
Constant temperature is 190 ℃ (463k), 230 ℃ (503
k) as described above except that the temperature is 260 ° C. (533 k).
It is a cage.

(C) α-Olefin Content When the propylene-based polymer is a propylene / α-olefin copolymer, the α-olefin content is 1 to 40% by weight in the case of a block copolymer, preferably 1-2
5% by weight, particularly preferably 2 to 20% by weight, most preferably 3 to 15% by weight. Further, in the case of a random copolymer, 10% by weight or less, preferably 0.5 to 7% by weight
Is.

(D) Characteristics by Pulse Method NMR The propylene-based polymer is a product of "Multiple-Pulse Nuclear".
Magnetic Resonanceon Some Crystalline Polymers
(Polymer Journal, Vol 3, No.4, pp 448-462 (1972);
K. Fujimoto, T. Nishi and R. Kado) pulse method N
Crystal component (I), constrained amorphous component (I
The respective proportions of (I) and the unconstrained amorphous component (III) are (I) / (II) in a weight ratio of 1.5 to 4, preferably 2 to 3.5, and (III) is It is 3 to 30% by weight, preferably 5 to 20% by weight. When (I) / (II) is smaller than the above range, the heat resistance is poor, which is not preferable. If it exceeds the above range, the tensile elongation property becomes insufficient, which is not preferable. When (III) is smaller than the above range, the impact resistance is poor, which is not preferable. If the amount exceeds the above range, the surface of the molded product is likely to be scratched and the product value is reduced, which is not preferable.

(E) Specific Example of Propylene-Based Polymer As the propylene-based polymer, a propylene-based polymer having the above-mentioned physical properties can be appropriately selected and used from commercial products.

Linear Low-Density Polyethylene A copolymer of ethylene and an α-olefin having 4 or more carbon atoms (component A) and a high-pressure low-density polyethylene (component)
The linear low-density polyethylene in the case where the linear low-density polyethylene is blended with B) to prepare a resin composition for injection molding is a copolymer of ethylene and another α-olefin, and ethylene and, for example, propylene, l-butene, l-pentene,
It is produced by copolymerizing 1-hexene, 1-octene, 1-heptene, 4-methylpentene-1,4-methylhexene-1,4,4-dimethylpentene-1 and the like. Among these α-olefins, α-olefins having 4 to 12 carbon atoms are preferable, and 1-hexene is particularly preferable. The production method is not particularly limited, but specifically, a gas phase method using a so-called Ziegler-based catalyst,
It can be manufactured by a method such as a slurry method, a solution method, or a high-pressure ionic polymerization method. The linear low density polyethylene preferably has the following properties.

(A) MFR The linear low density polyethylene JIS-K7210 (1)
MFR at 90 ° C, 2.16kg load) is 1-100
g / 10 minutes, preferably 1 to 50 g / 10 minutes, particularly preferably 10 to 40 g / 10 minutes. If the MFR is too high, the strength decreases, which is not preferable. Further, if the MFR is too low, the spiral flow is deteriorated, which is not preferable.

(B) Density The linear low-density polyethylene has a density according to JIS-K7112 of 0.90 to 0.935 g / cm ³ , preferably 0.91 to 0.93 g / cm ³ , and particularly preferably 0.
It is desirable to have physical properties of 915 to 0.925 g / cm ³ . If the density is too high, transparency is impaired, which is not preferable. On the other hand, if it is too low, a sticky component is increased on the surface of a molded product, which is not preferable.

(C) Peak of elution curve by temperature rising elution fractionation (TREF) The peak of the elution curve of the linear low density polyethylene is 1
One or more, preferably two or more, of which at least one peak temperature is 90 ° C. or higher.

(D) Q value The Q value of the linear low density polyethylene is preferably 2.
It is 5 to 6, particularly preferably 2.7 to 4.

Blending ratio The blending ratio of each component in the resin composition comprising the above component A and component B is as follows: component A: component B = 50: 50-9
It is 5: 5% by weight, preferably 60:40 to 90: 10% by weight, particularly preferably 70: 30% by weight to 90: 10% by weight. If the blending ratio of the component B is too large, the balance of physical properties such as flexibility and impact strength becomes poor, which is not preferable. If the blending ratio of the component B is too small, the effect of improving the moldability is small, which is not preferable.

(3) Other additional components Auxiliary additive components that are generally used as resin additives in the production of injection molded articles, such as antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, Lubricants, antistatic agents, and if necessary, pigments and the like can be added within a range that does not significantly impair the effects of the present invention.

(4) Physical Properties of Resin Composition The resin composition for injection molding of the present invention has an HAZE (haze) of 70% or less measured according to JIS-K7105 using an injection-molded sheet (thickness: 2 mm). It is preferably 50% or less, particularly preferably 40% or less, most preferably 30% or less, and particularly preferably 25% or less. Is. The MFR of the resin composition for injection molding of the present invention is preferably 5 to 100 g / 10 minutes, particularly preferably 5 to 50 g.
/ 10 minutes. The ME (memory effect) of the resin composition for injection molding of the present invention is preferably 1.1 or more, particularly preferably 1.2 or more.

[II] Method for Producing Injection Molded Body The resin and the resin composition of the present invention are melt-kneaded and pelletized by a uniaxial or biaxial extruder, a kneader blender, a Brabender plastograph, a Banbury mixer, a roll or the like. To do. The pellets are used to form a molded product by an injection molding machine. The injection molding is carried out under a general condition using an ordinary injection molding machine, but the present invention is not particularly limited by the conditions of the injection molding.

[0048]

The present invention will be described in detail below with reference to examples of the present invention. (1) Physical Property Measuring Method and Evaluation Method The measuring methods used in Examples and Comparative Examples are as follows. MFR: JIS K7210 compliant (ethylene polymer: 190 ° C, 2.16 kg load) (Propylene polymer: 230 ° C, 2.16 kg load) Density: JIS K7112 Elution curve measurement: temperature rise in the present invention Elution Fractionation (TRE)
The peak of the elution curve according to F) is such that once the polymer is completely dissolved at a high temperature and then cooled, a thin polymer layer is formed on the surface of the inert carrier, and then the temperature is raised continuously or stepwise, The eluted components are collected, the concentration thereof is continuously detected, and the compositional distribution of the polymer is measured by the peak of a graph (elution curve) drawn by the amount of elution and the elution temperature.

The elution curve was measured as follows. Cross sorter as a measuring device (Mitsubishi Yuka Co., Ltd.)
Manufactured by CFC T150A) according to the measurement method in the attached operation manual. This cross sorting device
Temperature rising elution fractionation (TREF) mechanism that separates samples using the difference in melting temperature and size exclusion chromatograph (Size Exclusi) that separates the separated fractions by molecular size
on Chromatography (SEC) is an online device.

First, a sample (copolymer) to be measured is used in a solvent (o-dichlorobenzene) at a concentration of 4 mg /
It is melted at 140 ° C. so that it becomes ml, and this is injected into the sample loop in the measuring device. The following measurements are automatically performed according to the set conditions. The sample solution held in the sample loop is separated by utilizing the difference in melting temperature.
0.4 ml is injected into a REF column (a stainless steel column with an inner diameter of 4 mm and a length of 150 mm, which is attached to the apparatus and is filled with glass beads as an inert carrier). The sample is then cooled at a rate of 1 ° C./min from 140 ° C. to 0 ° C. and coated on the inert carrier. At this time,
A polymer layer is formed on the surface of the inert carrier in the order of the highly crystalline component (those that are easily crystallized) to the low crystalline component (that is difficult to crystallize). After the TREF column was kept at 0 ° C for an additional 30 minutes, 2 ml of the dissolved component at the temperature of 0 ° C
Is injected from the TREF column to the SEC column (3 AD80M / S manufactured by Showa Denko KK) at a flow rate of 1 ml / min.

While fractionation by molecular size is being performed by SEC, the temperature is raised to the next elution temperature (5 ° C.) in the TREF column and the temperature is maintained for about 30 minutes. The measurement of each elution section by SEC was performed at 39 minute intervals. The elution temperature is raised stepwise at the following temperatures. 0, 5, 10, 15, 20, 25, 30, 35, 40,
45, 49, 52, 55, 58, 61, 64, 67, 7
0,73,76,79,82,85,88,91,9
4,97,100,102,120,140 ℃

The solution classified by the SEC column according to the molecular size was measured for absorbance in proportion to the concentration of the polymer with an infrared spectrophotometer attached to the apparatus (wavelength 3.42 μ, detected by stretching vibration of methylene). A chromatogram of the elution temperature range is obtained. Using the built-in data processing software, the baseline of the chromatogram of each elution temperature section obtained in the above measurement is drawn and the calculation processing is performed. The area of each chromatogram is integrated and an integrated elution curve is calculated. Also,
This integrated elution curve is differentiated with temperature to calculate the differential elution curve. The plot of the calculation result is output to the printer.
The plot of the output differential elution curve shows the elution temperature as 1 on the horizontal axis.
89.3 mm per 00 ° C, differential amount on vertical axis (total integrated elution amount was standardized to 1.0, and change amount at 1 ° C was used as differential amount)
It was performed at 76.5 mm per 0.1.

Q value: size exclusion chromatography (S
ize Exclusion Chromatography: SEC), and measured under the following measurement conditions, and the Q value was determined from the weight average molecular weight / number average molecular weight. A universal calibration curve was prepared using monodisperse polystyrene and calculated as the molecular weight of linear polyethylene. Model: Waters Model 150C GPC Solvent: o-dichlorobenzene Flow rate: 1 ml / min Temperature: 140 ° C Measurement concentration: 2 mg / ml Injection volume: 200 μl Column: Showa Denko AD80M / S 3 bottles

ME (Memory Effect) The melt indexer used in JIS-K7210 was used, the measurement conditions were set to a cylinder temperature of 240 ° C. and a constant speed extrusion rate of 3 g / min. To be done. The device is filled with the sample, only the piston is placed and after 6 minutes the prescribed extrusion rate is applied. Next, a graduated cylinder containing ethyl alcohol is placed immediately below the orifice, and a straight extrudate is collected. The diameter (D) of the sampled extrudate is measured with a micrometer, and the orifice diameter of the die is D ₀ , and ME is calculated by the following equation. ME = D / D ₀

Activation energy (Ea): Toyo Seiki Seisakusho's "Capirograph 1B PMD-C" was used,
The capillary has a diameter of 1 mm and a length of 10 mm, and the extrusion speed is 2.5, 5, 10, 20, 50, 100, 200.
The viscosity was measured at each temperature by auto-speed setting at m / min, and calculated by the activation energy (Ea) calculation method described above.

Pulse method NMR: JEOL manufactured by JEOL
-GSX270 ", 90 for samples at 30 ° C
A solid echo is measured with a pulse width of 1.8 ° C. and 1.8 μs. The obtained magnetization decay curve was logarithmically plotted, and the above-mentioned document "Multiple-Pulse Nuclear Magnetic Resonance on
Some Crystalline Polymers (Polymer Journal, Vol
3, No.4, pp 448-462 (1972); K. Fujimoto, T. Nishi and
R. Kado) separates the components by the method described in R. Kado) and obtains the fraction of each component.

(2) Evaluation method Spiral flow: injection molding was carried out under the following conditions, the mold was spiral and the flow path dimension was 2 mm in thickness, the width of the mold fixing surface was 6 mm, the width of the facing surface was 4 mm, and the flow path surface was spaced by 5 mm. Shred the scale of No. 1 and transfer to the test piece. The distance that the sample flows through the die from the transferred scale is measured. Machine type: Toshiba IS-90B Cylinder temperature: 240 ° C Mold temperature: 40 ° C Injection pressure: 800kg / cm ² Screw rotation speed: 70rpm Cushion amount: 5mm

Flexural modulus: conforming to JIS K7203 Haze: conforming to JIS K7105 Tensile strength at break (kg / cm ² ): JIS K711
3 Tensile elongation at break (%): In accordance with JIS K7113

Tensile impact strength (kg / cm ² ): A tester having the following performance is used. Capacity: 20 kgfcm Impact strength: 3.4 m / sec Hammer lifting angle: 150 ° Grasping tool: Crosshead press sheet (temperature 160 ° C, slow cooling method, thickness 0.5 m)
From m), punch out a dumbbell test piece with the following dimensions,
Measure its thickness. (Dimension) Length: 50 mm, width: 10 mm (minimum width of central part: 3 mm) After performing a blank test with a tester, a test piece is attached and a hammer is struck to read the tensile impact energy (E). The tensile impact strength is calculated by the following formula. (Formula) Tensile impact strength = (E−F) / (a × b) In the formula E: Tensile impact energy (kgfcm) F: Blank test value (kgfcm) a: Thickness (cm) b: Width (cm)

IZOD impact strength: JIS K7110
(Measurement temperature: -30 ° C) Embrittlement temperature: Complies with Dentsu Lab. Method (Notch depth: 0.3 m
m) Rockwell hardness: According to ASTM D785 A method (R hardness)

< Production Example 1> Copolymer of ethylene and α-olefin having 4 or more carbon atoms
Preparation of manufacturing the catalyst was performed by the method described in JP-A-61-130314. That is, to a complex ethylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride of 2.0 mmol, Toyo Stoufer's methylalumoxane was added in an amount of 1000 mol times, and diluted with toluene to 10 liters. A catalyst solution was prepared and the following polymerization was carried out. To a stirring autoclave type continuous reactor having an internal volume of 1.5 liters, ethylene and 1-hexene were fed at a composition of 83% by weight, the pressure inside the reactor was kept at 1500 kg / cm ² , and the temperature was kept at 180 ° C. The reaction was carried out at temperature. After the reaction, MFR is 31g / 10
An ethylene / 1-hexene copolymer (1-hexene content 28% by weight) having a density of 0.892 g / cm ³ was obtained.

Molding The obtained ethylene-1-hexene copolymer was 40 mmφ
It was melted at a temperature of 160 ° C. with a single screw extruder to obtain pellets. A press sheet was prepared using this pellet, and the embrittlement temperature was measured. The pellets were put into an injection molding machine SJ-45 (15oz-150t, 45 mmφ in-line screw type) manufactured by Meiki Seisakusho, and molded into an injection sheet under the following conditions. Mold: JIS2 No. molding temperature: 200 ° C., mold temperature (cooling temperature): 40 ° C. screw rotation speed: 80 rpm Injection Pressure: clamping pressure 95~105kg / cm ² 1 primary injection pressure 400 kg / cm ² 2 primary injection pressure 300 kg / cm ² Injection time: Primary injection 5 sec Secondary injection 10 sec Cooling 20 sec Evaluation was performed using the obtained sheet. The evaluation results are as shown in Table 1.

< Production Examples 2 to 5, Reference Examples 1 to 3> Regarding MFR, the temperature and pressure were adjusted during the polymerization, and the density was adjusted by changing the supply amount of α-olefin. A copolymer having the physical properties shown in 3 was produced , molded in the same manner as in Production Example 1, and evaluated. The evaluation results are shown in Tables 1 and 3.

[0064] <Production Example 6> Production Example 1 in an ethylene · alpha-olefin copolymer alpha-olefin is 1-butene, except that the feed to the reactor was 78 wt% same as in Production Example 1 Ethylene / 1-butene copolymer under the conditions (1-butene content 20% by weight)
Was manufactured. The copolymer was molded and evaluated in the same manner as in Production Example 1. The evaluation results are shown in Table 1.

<Examples 1 and 2 > The ethylene / α-olefin copolymer of Production Example 1 was prepared according to Table 2
Molded and evaluated in the same manner as in Production Example 1 except that the high-pressure low-density polyethylene having the physical properties shown in Table 1 was blended in the ratio shown in Table 2 to form a resin composition. The evaluation results are as shown in Table 2.

Reference Example 4 Molding was carried out in the same manner as in Production Example 1 except that the ethylene / α-olefin copolymer of Production Example 1 was replaced by the high-pressure low-density polyethylene having the physical properties shown in Table 3, and evaluated. did. The evaluation results are shown in Table 3.

Reference Example 5 An ethylene / α-olefin copolymer having the physical properties shown in Table 3 produced by using a Ziegler catalyst was used in place of the ethylene / α-olefin copolymer of Production Example 1. except
It was molded and evaluated in the same manner as in Production Example 1. Table 3 shows the evaluation results.
As shown in.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

[Table 3]

<Example 3 > Component A used in Examples 3 to 6 and Comparative Examples 1 to 5 (d)
Copolymer of ethylene and α-olefin having 4 or more carbon atoms)
Preparation of manufacturing the catalyst was performed by the method described in JP-A-61-130314. That is, to a complex ethylenebis (4,5,6,7-tetrahydroindenyl) zirconium dichloride 2.0 mmol, Toyo Stoufer's methylalumoxane was added in an amount of 1000 mol times, and diluted with toluene to 10 liters. A catalyst solution was prepared and the following polymerization was carried out. A mixture of ethylene and 1-hexene was fed to a stirring autoclave type continuous reactor having an internal volume of 1.5 liters so that the composition of 1-hexene was 83% by weight, and the pressure in the reactor was 1600 kg / c.
The reaction was carried out at a temperature of 165 ° C. while maintaining m ² . After completion of the reaction, MFR is 13 g / 10 min, density is 0.898 g / c
m ³ , the TREF elution curve has one peak, the peak temperature is 55 ° C., an elution amount other than the peak is present, and the elution amount at 40 ° C. is 15%. The ethylene / 1-hexene copolymer (1-
Hexene content 20 wt%) was obtained (C ₂ -C _6).

Component B: Examples 3 to 6 and Comparative Example 1 to
Component B used in 4 (high pressure low density polyethylene), professional
The pyrene polymer and the linear low density polyethylene each have the following physical properties. (A) High pressure method low density polyethylene (HPLD): MF
R = 20 g / 10 min, density = 0.918 g / cm ³ , M
E = 1.5, Q value = 7, Ea = 16 KJ / mol

(B) High-pressure method low-density polyethylene (HPLD
): MFR = 40 g / 10 minutes, density = 0.923 g /
cm ³ , ME = 1.3 Q value = 11, Ea = 19 KJ / m
ol

(C) High pressure method low density polyethylene (HPLD
): MFR = 1 g / 10 minutes, density = 0.923 g / c
m ³ , ME = 2.0 Q value = 7, Ea = 10 KJ / mol

(D) Propylene / ethylene block copolymer (PP): MFR = 10 g / 10 minutes, Ea = 12K
J / mol, α-olefin content = 2% by weight, pulsed NMR component (I) / component (II) = 2.5, component (III)
= 6% by weight

(E) Propylene / ethylene block copolymer (PP): MFR = 30 g / 10 minutes, Ea = 16K
J / mol, α-olefin content = 4% by weight, pulsed NMR component (I) / component (II) = 2.5, component (III)
= 8% by weight

(F) Propylene homopolymer (PP): M
FR = 11 g / 10 min, Ea = 13 KJ / mol, component (I) / component (II) = 2.4, component (I
II) = 5% by weight

(G) Linear low density polyethylene (ethylene / 1-butene copolymer produced using Ziegler type catalyst: LLDPE): MFR = 30 g / 10 min, density = 0.919 g / cm ³ , TREF peak number = 2, peak temperature = 78 ° C. and 92 ° C., Q value = 4, Ea = 12K
J / mol

Compounding / Molding Component A and component B were dry blended, and the resulting composition was melted at a temperature of 160 ° C. with a 40 mmφ single screw extruder to form pellets. A press sheet was prepared using this pellet, and the tensile impact strength was measured. Injection molding machine SJ-45 (15oz-150t, 4 manufactured by Meiki Seisakusho)
5 mmφ in-line screw type), and molded into an injection sheet under the following conditions, and the molded product was evaluated. The evaluation results are shown in Table 4. Mold: JIS2 No. molding temperature: 200 ° C., mold temperature (cooling temperature): 40 ° C. screw rotation speed: 80 rpm Injection Pressure: clamping pressure 95~105kg / cm ² 1 primary injection pressure 400 kg / cm ² 2 primary injection pressure 300kg / cm ² Injection time: Primary injection 5sec Secondary injection 10sec Cooling 20sec

<Examples 4 to 6 and Comparative Examples 6 to 8> The components A and B shown in the table were used, and molding was carried out in the same manner as in Example 3 except that the compounding ratio and the like were changed, and the evaluation was made. went. The evaluation results are shown in Tables 4 to 7.

[0081] <Comparative Example 5> ethylene obtained in Example 3, 1-hexene copolymer only (C ₂ -C _6), was formed in the same manner as in Example 3, was evaluated. The results are shown in Table 6.

<Comparative Examples 9 and 10> Linear low density polyethylene (LLDPE, density = 0. 0) produced by using a Ziegler type catalyst instead of the component A.
(922 g / cm ³ , MFR = 16 g / 10 min) was used and molded in the same manner as in Example 3 and evaluated. The results are shown in Table 8.

[0083]

[Table 4]

[0084]

[Table 5]

[0085]

[Table 6]

[0086]

[Table 7]

[0087]

[Table 8]

[0088] molding a resin composition out morphism of the present invention is excellent in transparency, is excellent in strength at room temperature or low temperatures, has good balance between strength and rigidity, Tupperware (registered trademark) manufactured by flexible resin not only is extremely useful as a material for such as food containers, has equal high transparency and vinyl chloride resin, and since it is a material excellent in strength at low temperatures, industrially very useful.

─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-4-372637 (JP, A) JP-A-61-130314 (JP, A) JP-A-5-310847 (JP, A) JP-A-5- 5051 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 23/00-23/36 B65D 85/50 C08F 210/00, 210/18

Claims (3)

(57) [Claims] 1. A resin composition for injection molding of a flexible resin food container, which comprises the following components A and B. Component A: Copolymer of ethylene having the properties (a) to (c) shown below and an α-olefin having 4 or more carbon atoms.
50 to 95% by weight (a) MFR (190 ° C, 2.16 kg load) is 10
˜120 g / 10 min (b) Density is 0.915 g / cm ³ or less (c) There is one peak in the elution curve obtained by temperature rising elution fractionation (TREF), and the peak temperature is 85
Component B having a temperature of not higher than ° C: high having the properties (a) to (c) shown below
Pressure method low density polyethylene 5 to 50 wt% (a) MFR (190 ° C, 2.16 kg load) is 1 to
50 g / 10 min (b) Density 0.915 to 0.93 g / cm ³ (c) ME (3 g) 1.3 or more Wherein component A composition according to claim 1 is obtained by using a metallocene catalyst. 3. A haze of 70% or less and a flexural modulus of 15 obtained by injection molding the composition according to claim 1 or 2.
An injection-molded product with a pressure of 00 kgf / cm ² or less.