JPS63297442A - Thermoplastic polymer composition - Google Patents

Abstract

PURPOSE:To obtain a composition having excellent flexibility, low-temperature characteristics, oil resistance and heat-sealability and suitable for packaging film, by compounding a specific ethylene.alpha-olefin copolymer to a copolymer of ethylene and a carboxyl-containing monomer. CONSTITUTION:The objective composition is composed of (A) 95-50wt.% (excluding 50wt.%) of a copolymer derived from ethylene and a carboxyl-containing monomer (derivative) and having a carboxyl content of 5-50wt.% (preferably ethylene-ethyl acrylate copolymer or ethylene-vinyl acetate copolymer) and (B) 5-50wt.% (excluding 50wt.%) of a copolymer having a density of 0.86-0.91g/cm<3>, maximum peak temperature (measured by DSC) of >=100 deg.C and boiling n-hexane insoluble content of >=10wt.% and produced by polymerizing ethylene and a 3-12C alpha-olefin (preferably propylene or 1-butene) in the presence of a catalyst composed of an organic Al compound and a solid component containing at least Mg and Ti.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to thermoplastic polymer compositions, and more particularly to copolymers of ethylene and carboxyl group-containing monomers and specific ethylene/a-olefin copolymers. The present invention relates to a thermoplastic polymer composition which is suitable for packaging films and has excellent flexibility, low-temperature properties, oil resistance, heat-sealing properties, etc.

[Prior art]

Ethylene-based polymers have a wide range of applications because they have various features including flexibility and moldability. In particular, demand for applications such as various containers, films and sheets, hoses and tubes, materials for covering electric wires, various electrical appliance parts, and various packing materials has increased significantly in recent years, and along with this, requirements for properties have also become stricter. It's coming. When forming these into films and sheets and using them for packaging, especially when used as so-called heavy packaging bags for storing fertilizers, synthetic resins, industrial chemicals, sugar, salt, etc., mechanical strength, heat resistance, In addition to flexibility, properties such as flexibility, low-temperature properties, oil resistance, and heat-sealing properties are required. As a countermeasure against these problems, for example, compositions made by blending ethylene-ethyl acrylate copolymer and niethylene-propylene copolymer rubber have excellent flexibility and low-temperature properties, but have poor heat resistance and oil resistance. etc. may be significantly inferior.

Also, compositions in which linear low density polyethylene is blended with ethylene-ethyl acrylate copolymer (for example,
1-225235), the heat resistance and oil resistance are improved, but the flexibility, low-temperature properties, low-temperature heat sealability, etc. are inferior.

[Problems to be Solved by the Invention] The present invention aims to provide a new thermoplastic polymer composition suitable for packaging films, which has well-balanced improvements in flexibility, low-temperature properties, oil resistance, and heat-sealing properties. purpose.

[Means to solve the problem]

As a result of intensive studies in line with the above objectives, the present inventors found that
By blending a specific ethylene/a-olefin copolymer with a copolymer consisting of ethylene and a carboxyl group-containing monomer or its derivative, an excellent thermoplastic polymer with a well-balanced combination of various properties is produced. The inventors have discovered that a composition can be obtained, and have arrived at the present invention based on this finding.

That is, the present invention provides (a) a copolymer containing ethylene and a carboxyl group-containing monomer or a derivative thereof with a weight of less than 95% and a weight of less than 50%! and (b)
I) Density 0,860~0.910? /cmko,i)
Maximum peak temperature by differential scanning calorimetry (DSC) 1
Copolymers containing ethylene and unsaturated carboxylic acids or esters thereof, such as ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, polymers, ethylene-ethyl acrylate copolymers, ethylene-ethyl methacrylate copolymers, ethylene-maleic anhydride copolymers, and metal salts thereof (for example, ionomer resins). Other examples of copolymers include:
Examples include ethylene-vinyl acetate copolymer. The content of the carboxyl group is 5 to 50% by weight,
Preferably it is in the range of 10 to 40% by weight.

Among these, ethylene-ethyl acrylate copolymer, ionomer resin or ethylene-vinyl acetate copolymer are particularly preferred.

It is a copolymer. Specific α-olefins include propylene, 1-butene, 4-methyl-1-pentene, 1
-hexene, 1-octene, 1-decene, 1-dodecene and the like. Particularly preferred among these is the olefin: '!=1-7f.The α-olefin content in the ethylene/a-olefin copolymer is 5
It is preferable that it is 40 mol.

The ethylene/α-olefin copolymer (b) used in the present invention can be produced as follows.

The catalyst system used first consists of a solid catalyst component containing at least magnesium and titanium and an organoaluminum compound. Examples of the solid catalyst component include metal magnesium; magnesium hydroxide: magnesium oxide; magnesium salts such as magnesium carbonate and magnesium chloride; double salts and double oxides containing a magnesium atom and an element selected from silicon, aluminum, and calcium; .

Carbonates, chlorides, hydroxides, etc.: Furthermore, inorganic solid compounds containing magnesium, such as those obtained by treating or reacting these inorganic solid compounds with oxygen-containing compounds, sulfur-containing compounds, aromatic hydrocarbons, or halogen-containing substances. To,
Examples include those in which a titanated metal is supported by a known method.

The above oxygen-containing compounds include, for example, water; organic oxygen-containing compounds such as alcohols, phenols, ketones, aldehydes, carboxylic acids, esters, polysiloxanes, and acid amides; and inorganic oxygen-containing compounds such as metal alkoxides and metal oxychlorides. can be exemplified. Examples of the sulfur-containing compound include organic sulfur-containing compounds such as thiol and thioether, and inorganic sulfur compounds such as sulfur dioxide, sulfur trioxide, and sulfuric acid. Examples of aromatic hydrocarbons include various monocyclic and polycyclic aromatic hydrocarbon compounds such as benzene, toluene, xylene, anthracene, and phenanthrene. Examples of halogen-containing substances include compounds such as chlorine, hydrogen chloride, metal chlorides, and organic halides.

On the other hand, examples of the titanium compound supported on the magnesium-containing inorganic solid compound include titanium halides, alkoxy halides, alkoxides, and halogenated oxides. As the titanium compound, a tetravalent titanium compound and a trivalent titanium compound are suitable, and the tetravalent titanium compound specifically has the general formula Ti(OR).
HX4-n' where R represents an alkyl group, aryl group or aralkyl group having 1 to 20 carbon atoms, X represents a halogen atom, and n is an integer of 0≦n≦4) is preferred. , titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, monomethoxytrichlorotitanium, dimethoxydichlorotitanium, trimethoxymonochlorotitanium, tetramethoxytitanium, monoethoxytrichlorotitanium,
Jetoxydichlorotitanium, triethoxymonochlorotitanium, tetraethoxytitanium, monoisopropoxytrichlorotitanium, diisopropoxydichlorotitanium, triisopropoxymonochlorotitanium, tetralinepropoxytitanium, monobutoxytrichlorotitanium, dibutoxydichlorotitanium, monopentoxy Examples include trichlorotitanium, monophenokiditrichlorotitanium, diphenoxydichlorotitanium, triphenoxymonochlorotitanium, and tetraphenoxytitanium. Trivalent titanium compounds can be obtained by reducing tetravalent titanium such as titanium tetrachloride and titanium tetrabromide with hydrogen, aluminum, titanium, or organometallic compounds of metals from groups ■ to ■ of the periodic table. Examples include titanium trihalide. Also, the general formula Ti(OR)mX4. (Here, R has 1 to 20 carbon atoms.
represents an alkyl group, aryl group or aralkyl group,
X represents a halogen atom, m is an integer of 0 < m < 4 The following titanium compounds are mentioned.

Among these titanium compounds, tetravalent titanium compounds are particularly preferred.

Another example of a catalyst system is a catalyst system in which a reaction product of an organomagnesium compound such as a so-called Grignard compound and a titanium compound is used as a solid catalyst component, and an organoaluminum compound is combined therewith.

In addition, as an example of other catalyst systems, 5i is used as a solid catalyst component.
An example is a solid material obtained by contacting an inorganic oxide such as 02, Al2O3, etc. with the above-mentioned solid catalyst component containing at least magnesium and titanium, and a combination of this with an organoaluminum compound.

Specific examples of organoaluminum compounds to be combined with the solid catalyst component described above include general formulas R3Al, R
, AIX.

Organoaluminum compounds of RAIXz, RzAlOR, RAI (OR)X and RmAl*Xs (where 8
is an alkyl group, aryl group, or aralkyl group having 1 to 20 carbon atoms, X represents a halogen atom, and R may be the same or different), and preferred are compounds represented by triethylaluminum, triisobutylaluminum, trihexylaluminum , trioctylaluminum, diethylaluminum chloride, diethylaluminum ethoxide, ethylaluminum sesquichloride, and mixtures thereof.

The amount of the organoaluminum compound to be used is not particularly limited, but it can usually be used in an amount of 0.1 to 1,000 times the amount of the titanium compound.

The polymerization reaction is carried out in the same manner as a typical olefin polymerization reaction using a Ziegler type catalyst. That is, all reactions are carried out in a gas phase, in the presence of an inert solvent, or in the presence of the monomer itself as a solvent, in a state substantially free of oxygen, water, etc.

The olefin polymerization conditions are a temperature of 20 to 300°C, preferably 40 to 200°C, and a pressure of normal pressure to 70 kW.
/cn? -G.

Preferably, it is 2 to 22 2.G to 60 to 3.G. The molecular weight can be effectively controlled by adding hydrogen into the polymerization system, which can be controlled to some extent by changing polymerization conditions such as polymerization temperature and catalyst molar ratio. Of course, a two-step or more multi-step polymerization reaction with different polymerization conditions such as hydrogen concentration and polymerization temperature can also be carried out without any problem.

Density of (b) ethylene/a-olefin copolymer synthesized as above (according to LIS K6760)
is 0.860 to 0.91097 cm3, preferably 0.
870 = 0.905 t/ctrr".DS
The temperature (Tm) of the maximum peak due to CK is 100°C or higher, preferably 110°C or higher. Boiling n-hexane insoluble content (C, insoluble content) is 10 weight tS or more, preferably 20 to 9
It is 5% by weight.

(b) The density of the ethylene/a-olefin copolymer is 0.
If it is less than 860 fΔ-, the tensile strength of the thermoplastic polymer composition decreases, and the surface of the composition becomes sticky, impairing its appearance. Further, if the density is 0.910PΔ- or more, the flexibility decreases, which is undesirable. If Tm is less than 100°C, the tensile strength decreases, stickiness occurs on the surface of the composition, and heat resistance and oil resistance also decrease, which is undesirable. C6
When the insoluble content is less than 10% by weight, the tensile strength similarly decreases and the surface of the composition becomes sticky, which is undesirable.

Component (b) above has a coexistence of highly crystalline parts and non-quality parts, and has the mechanical strength, heat resistance, and oil resistance of conventional crystalline polyolefins, and the rubber-like elasticity and flexibility of amorphous polymers. It is a special ethylene/a-olefin copolymer that has properties such as properties, and by blending it with component (a), it maintains the various properties required for packaging films in an extremely well-balanced manner. It was found that a composition with the following properties can be easily obtained.

(b) The method for measuring Tm and C6 insoluble content by DSC regarding the ethylene/a-olefin copolymer is as follows: (Method for measuring 'rm by DSC) From a 100 μm thick film formed by hot press molding. Approximately 5y
Precisely weigh sample 9 and DSC it! ! 1.
After raising the temperature to 70° C. and maintaining it at that temperature for 15 ml, it is cooled to 0° C. at a cooling rate of 2.5 C/min. Next, from this state, the temperature at the peak position of the temperature increase rate is defined as Tm.

(C, method for measuring insoluble content) A sheet with a thickness of 200 μm was formed using a heat press, and the specifications were printed (no changes to the contents). Three sheets of 20 au + x 30 m were cut from this, and they were tested using a double-tube method. Boiling sn using a Nxley extractor
- Perform a 5 hr extraction with hexane. The n-hexane insoluble matter was taken out, and after vacuum drying (7 hours, 50°C),
The C6 insoluble content is calculated using the following formula.

The blending composition of (a) a copolymer containing ethylene and a carboxyl group-containing monomer or a derivative thereof and (b) an ethylene/a-olefin copolymer in the thermoplastic polymer composition of the present invention is as follows: The total amount of component (a) and (b) is 10,000% by weight, and component (a) is 95 to 5%.
0]i amount% (however, 50% by weight is not included), preferably 85 to 55% by weight, and component (b) is 5 to 50% by weight
(However, 50% by weight is not included), preferably 15 to 45
Weight%. If the amount of component (b) is less than 5% by weight, the low temperature properties will be insufficient and the oil resistance will also be low. On the other hand, 50
If it exceeds % by weight, the heat-sealing strength in low-temperature heat-sealing may become insufficient, which is not preferable.

Any known technique can be used to produce the thermoplastic polymer composition. A typical example is a method of mechanically melt-kneading the above-mentioned compound, and melt-kneading can be performed using a -screw and twin-screw extruder, a Banbury mixer 1, various types of Nigoo, rolls, etc. The temperature of melt-kneading is generally 3
00°C or lower, preferably at a temperature at which the compound used is sufficiently melted, usually preferably from 150 to 250°C.

In addition, carbon black, calcium carbonate,
Fillers such as silica, metal fibers, and carbon fibers, or additives such as antioxidants, flame retardants, and colorants may be added as necessary. Furthermore, crystalline polyolefins such as high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, natural rubber, various synthetic rubbers, styrenic thermoplastics, etc. Various resins and rubbers such as elastomers may be blended as necessary.

〔Effect of the invention〕

The thermoplastic polymer composition obtained by the present invention not only achieves the above objectives as described below, but also exhibits other excellent features. That is, (
a) Excellent flexibility and low temperature properties.

(b) It has excellent heat-sealing properties, and high sealing strength can be obtained by heat-sealing at low temperatures.

(C) Excellent heat resistance and oil resistance.

(d) It has low density and is extremely lightweight.

Since the thermoplastic polymer composition of the present invention exhibits the above-mentioned excellent properties, it has an extremely wide range of applications as packaging films and sheets, bag-like containers made from these, and other materials. Be expected.

[Examples and comparative examples]

Hereinafter, the present invention will be specifically explained based on Examples and Comparative Examples, but the present invention is not limited thereto. In addition, the preparation of the test sheet and the physical property measurement in each Example and Comparative Example were carried out by the following method.

(Preparation of test sheet) The produced thermoplastic polymer composition was
0iu +
After 1n preheating, 5ml1n was pressure molded at the same temperature, 150 K, Δ-, and then 150 ky/? at 30°C. Cooled for 10 min while keeping the pressure at 11". Further, cooled at 50°C for 20 hr.
After annealing, the test sheet was left at room temperature for 24 hours.

(Flexibility) As flexibility at room temperature, 100% tensile stress is JIS
Measured according to K6301. A dumbbell-shaped No. 3 test piece was prepared from a test sheet with a thickness of 2jIj, and this was tested using a tensile tester at 50. The test piece was pulled at a speed of 1
Tensile stress at 00% elongation (kp f 7cm”)
I asked for

(Low-temperature properties) Water temperature was measured in accordance with JIS K6773 as an index representing the ability to retain rubber-like elasticity at low temperatures. Thickness approx. 1
A test piece was prepared from a test sheet of 1LII.

(Oil resistance) Volume change rate when immersed in oil is JIS K6301
Measured according to A test piece was prepared from a test sheet with a thickness of 2u, and the test oil was the same JIS specified lubricant (
A immersion test was conducted at 70° C. for 22 hours to determine the volume change rate (c%).

(Heat sealing strength) Using a T-die with a 40mφ extruder, seal at 160°C to a thickness of 30mm.
A 15 m wide film was formed by molding two films, and the sealed sample film was cut out into a strip with a width of 15 m, and the strength of the heat-sealed portion was measured using a tensile tester at a tensile speed of 300 m/min.

The following were used as components (a) and (b).

(a) Component: (4) Ethylene-ethyl acrylate copolymer (1) (ethyl acrylate content 20% by weight; product name: Shiraishi Rexron A4200, manufactured by Nippon Petrochemical Co., Ltd.) Engraving of the specification (no changes to the contents) ) (B) Ethylene-ethyl acrylate copolymer (2)
(Ethyl acrylate content: 15% by weight; trade name: Futamekashi Xuron A2150. Manufactured by Nippon Petrochemical Co., Ltd.) C) Ethylene-
Vinyl acetate copolymer (vinyl acetate content 15% by weight; trade name Futamekashi Xuron V270, manufactured by Nippon Petrochemical Co., Ltd.) (b) Components: (b) Ethylene/1-butene copolymer Substantially anhydrous magnesium chloride Using a catalyst consisting of a solid catalyst component obtained from , L2-dichloroethane and titanium tetrachloride, and triethylaluminum, ethylene and 1-butene were copolymerized to obtain an ethylene/17-butene copolymer.

The 1-butene content of this ethylene/1-butene copolymer is 12 mole, the density is 0.89697 cm3, and the Tm is 12
0°C, C6 insoluble content is 82% by weight, MFR is 0.9 P/
It was 10 min.

(6) Ethylene-propylene copolymer Ethylene and propylene are copolymerized using a solid catalyst component obtained from substantially anhydrous magnesium chloride, anthracene and titanium tetrachloride, and a catalyst consisting of (1) ethyl tetrarealuminum. Polymerization was performed to obtain an ethylene-propylene copolymer.

The propylene content of this ethylene-propylene copolymer is 14 molty, the density is 0.898 f/m', the 'rm is 122°C, the C6 insoluble content is 86% by weight, and the MFR is 1.0.
It was t710 min.

The above components (a) and (b) were melt-kneaded at 200° C. using a 30 wφ extruder according to the blending ratios shown in Table 4. Table 1 shows the evaluation results of various properties of the obtained mixture.

Comparative Examples 3 to 5 Engraving of specification (additional L to replace content)・(
Example 1 to b) except that the following polymer was used as the component.
It was prepared in exactly the same manner as in No. 6 and its properties were evaluated. Table 1 shows the blending ratio and properties.

(F) Ethylene-propylene copolymer rubber Ethylene-propylene copolymer rubber was obtained using a vanadyl trichloride-ethylaluminum sesquichloride catalyst.

The propylene content of the copolymer rubber is 26% by weight, the Mooney viscosity (ML□+4.100°C) is 73, and the density is 0.86.
2? /cm3. Further, no peak was observed by DSC, and no C6 insoluble matter was observed at all.

(G) Ethylene-1-butene copolymer rubber (F
) An ethylene-1-butene copolymer rubber was synthesized using the same catalyst system.

0,895 f 7cm3, 'rm is 81℃, C6 insoluble content 1.5% by weight, MFR is 3.5 y/ 10 min
Met.

(6) Linear low-density polyethylene (trade name: 8 stone Sunilex AF2320, manufactured by Nippon Petroleum Chemicals) Comparative Example 6 (A) Ethylene-Ac 1 of component (a) in Example 2
) The preparation was carried out in exactly the same manner as in Example 2, except that (F) ethylene-propylene copolymer rubber was used instead of ethyl phosphate copolymer (1), and the properties were evaluated. The results are shown in Table 1.

From the above results, it is concluded that the thermoplastic heavy material composition obtained by the present invention exhibits well-balanced and excellent performance in terms of flexibility, low-temperature properties, oil resistance, and heat-sea/L strength. September 22, 1988 Kunio Ogawa, Commissioner of the Patent Office 1 Display of the case 1988 Patent Application No. 132035 2 Name of the invention Thermoplastic polymer composition 3 Relationship to the amended person case Patent applicant Name Japan Petrochemical Co., Ltd. 4th Agent August 25, 1988 7 No amendments.

Claims (3)

[Claims] (1) (a) A copolymer containing ethylene and a carboxyl group-containing monomer or its derivative in an amount of 95% by weight or less but more than 50% by weight, and (b) i) Density of 0.8
60 to 0.910 g/cm^3, ii) Maximum peak temperature measured by differential scanning calorimetry (DSC) of 100°C or higher, and iii) Ethylene/α-olefin copolymer with boiling n-hexane insoluble content of 10% by weight or higher. 5% by weight or more
A thermoplastic polymer composition comprising less than 0% by weight. (2) Claim 1, wherein the copolymer (a) containing ethylene and a carboxyl group-containing monomer or a derivative thereof is an ethylene-ethyl acrylate copolymer or an ethylene-vinyl acetate copolymer. The thermoplastic polymer composition described in . (3) The above (b) ethylene/α-olefin copolymer is produced by combining ethylene and an α-olefin having 3 to 12 carbon atoms in the presence of a solid component containing at least magnesium and titanium and a catalyst consisting of an organoaluminum compound. The thermoplastic polymer composition according to claim 1, which is a copolymer obtained by polymerizing the following.