JPS5971349A - Ethylenic resin composition - Google Patents

Abstract

PURPOSE:To provide a composition having excellent moldability, and giving a film having high transparency and excellent mechanical strength even at a relatively high density, by compounding a specific high-pressure polyethylene with a high or medium density polyethylene and a medium or low density linear polyethylene. CONSTITUTION:A composition having an M.I of 0.1-5g/10min and a density of 0.920-0.940g/cm<3> is prepared by mixing (A) a copolymer of ethylene and a 4- 12C alpha-olefin (especially preferably butene-1) having an M.I of 0.1-10g/10min and a density of 0.910-0.940g/cm<3> with (B) a high-pressure polyethylene having an M.I of 0.1-20g/10min, preferably 1.0-5.0g/10min and a density of 0.910- 0.935g/cm<3> and (C) a homogeneous molten mixture of (C1) a high or medium density polyethylene having an average molecular weight of 100,000-1,000,000 and (C2) another high or medium density polyethylene having an average molecular weight of 1,000-100,000 at a ratio (C1:C2) of 30:70-80:20 wherein the molecular weight ratio of C1/C2 is 5-200. The ratio of A:B is 70:30-95:5, and the ratio of the component (C) in the composition is 5wt% or more and below 50wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ethylene resin composition having excellent mechanical properties, transparency and moldability.

So-called linear medium-low density polyethylene, which is a copolymer of ethylene and α-olefin, has superior mechanical strength and resistance to environmental stress cracking (BSOR) compared to conventional high-pressure polyethylene.
) and heat resistance, and is becoming widely used in various applications.

Particularly in the film field, high-pressure polyethylene is rapidly being replaced because of its ability to reduce costs through so-called downgauging, as well as its heat resistance and heat-sealing properties.

However, when carrying out inflation molding using this linear medium-low density polyethylene, the transparency of the film is poor and a special cooling method must be used for molding, and the tension at the time of melting is higher than that of high-pressure polyethylene. Since it is extremely low compared to that of , it has problems such as bubble vibration, resin sag, etc., making stable molding difficult.

Furthermore, linear medium-low density polyethylenes with relatively high densities have a marked decrease in mechanical strength, and in particular, butene-1 copolymers have a marked lack of strength.

In order to improve the above-mentioned drawbacks, the present inventors conducted intensive research and found that by uniformly melt-mixing a specific high-medium density polyethylene, a specific high-pressure polyethylene, and a linear medium-low density polyethylene within a specific range, the present inventors achieved extremely high moldability. The present invention was based on the fact that it is possible to obtain a film which has excellent mechanical strength even when the film has a relatively high density, and is highly transparent.

That is, the present invention has a melt index of 0.1 to 1.
0ri/10 min density is 0.910~0.940ri/cPn
Copolymer (A) of ethylene and α-olefin having 4 to 12 carbon atoms, with a melt index of 0.1 to 2op
A homogeneous melt mixture consisting of high-pressure polyethylene (B) having a /lo minute density of 0.910 to 0.93517 cm, and high-molecular weight high-medium density polyethylene (0) and low-molecular weight high-medium density polyethylene (D). A composition consisting of a certain (E), in which (i) (0) has an average molecular weight of 100,000 to 1,000,000,
The average molecular weight of (D) is from 10,000 to 100,000, and (0
) to (D) is 5 to 200, and (ii)
The mixing ratio of (A), (B) and U) is (A) to (
B) in the composition is 70:30 to 95:5;
) The mixing ratio of (0) and (D) is 30:70 to 80:2.
(iii) The melt index of the composition after uniform melting and mixing is 0.1 to 5 y/lO min, and the density is 0.920.
The present invention relates to an ethylene resin composition having excellent mechanical properties, transparency, and moldability of ~0.940 r/c1n3.

Some compositions of high and medium density polyethylene and low density polyethylene are already known. However, the composition of the present invention is not disclosed or even suggested in the concepts of these known compositions. For example, in Special Publication No. 43-24532 (,) Low Density J (
Polyethylene, (b) density 0.930 or more, M, I value 0
．． A composition comprising polyethylene 0.3 to 8 modified 1L having a density of 1 or less and (C) a polyethylene 1 to 33 by weight having a density of 0.930 or more and an M value of 0.1 or more is disclosed. is one type of low-density polyethylene,
This composition is different from the present invention in that the mixing ratio is different.

The copolymer (A) of ethylene and α-olefin used in the present invention will be explained.

The copolymer (A) is so-called linear medium-low density polyethylene.

M and I of the copolymer (A) are in the range of O01 to 10y/lo minutes, preferably 0.3 to sy/10 minutes, and more preferably 0.5 to 2.0 P/lo minutes.

When M and I are lower than this range, moldability deteriorates, and when M and I are higher than this range, mechanical strength decreases.

The density is 0.910 to 0.940 f7cm", preferably 0.915 to 0.935 y/cms. If the density deviates from this range, the moldability, mechanical strength, transparency, etc. according to the present invention will be affected. A balanced composition cannot be obtained.-As a catalyst for producing copolymer (A), /・
Transition metal compounds of the first to older groups such as titanium halides or sodium halides, and organic compounds such as alkylaluminum-magnesium complexes, alkylalkoxyaluminum-magnesium complexes, alkylaluminum or alkylaluminum chlorides, etc. The so-called Ziegler type is used in combination with a Group 1-III organometallic compound such as aluminum.

Suspension polymerization, solution polymerization, gas phase polymerization and 500-3000
It is manufactured by various high-pressure polymerization processes in which polymerization is carried out at atmospheric pressure and at 150 to 300°C.

As the α-olefin having 4 to 101′IiI carbon atoms,
All contains 1 butene, 1 pentene, 1 hexene,
4-methylpentene-1, heptene-11 octene-1
Examples include nonene-1, decene-1, butene-1
is particularly preferred.

There is a correlation between the α-olefin content in the copolymer (A) and the density of the copolymer.
The content of α-olefin is determined by the density of A).

Next, the high-pressure polyethylene (B) used in the present invention will be explained.

M and I of high pressure ethylene (B) are 0.1 to 20y/
It is 10 minutes, preferably 0.5 to 10 x 710 minutes, and more preferably 1.0 to 5.0 x 710 minutes.

Outside this range, the effects of the present invention cannot be obtained.

The density is 0.910-0.935 y/α3, so-called high-pressure process-1J ethylene.

The method for producing high-pressure polyethylene (B) may be either a tubular method or an autoclave method.

Next, high-molecular-weight high-molecular-weight ff1l, which is a component of the present invention,
! Polyethylene (0) and low molecular weight high-medium density polyethylene (D) are ethylene homopolymers or copolymers of ethylene and other olefins and dienes having a density of 0.93 to 0.98. Other olefins and dienes used in copolymerization include propylene, butene, pentene,
Examples include α-olefins such as 4-methylpentene-1, hexene, octene, and decene, diolefins such as sitadiene and isoprene, and cycloolefins such as cyclopentene, cyclohexene, cyclopentadiene, and norphene.

The high molecular weight component (0) has an average molecular weight of 100,000 to 1 million, preferably 300,000 to 800,000, and the low molecular weight component (
D) has an average molecular weight of 0.1 to 100,000, preferably 0.
50,000 to 50,000. The ratio of the molecular weights of (0) and (D) is 5
to 200, preferably 10 to 100. When the molecular weight ratio is lower than 5, the excellent physical properties of the present invention are particularly good.
Also, the molecular weight distribution is not sufficiently wide, resulting in poor moldability. On the other hand, even if the molecular weight ratio becomes more than 200,
There is no advantage in improving physical properties and moldability, and it is also disadvantageous in terms of manufacturing.

The high-medium density polyethylenes (C) and (D) can be produced by conventional suspension polymerization, gas phase polymerization, or solution polymerization. The catalyst used in the polymerization may be any catalyst as long as it can produce high-medium density polyethylene (0) and (D). However, industrially, it is desirable to have a highly active catalyst that can omit the decatalyst step, and the present inventors invented Japanese Patent Publication Nos. 52-36788 and 52-36.
No. 790, No. 52-36791, No. 52-36795
Catalysts and polymerization methods described in JP-A-52-127490 and JP-A-53-70991 are suitable. As a manufacturing method, it is also possible to manufacture the high-medium density polyethylenes (C) and (D) by a multi-stage continuous method of two or more stages. It is also possible to produce a mixture of C and D all at once by continuously polymerizing C and D in series.

Next, the mixing ratio of components (A), (B) and (E) will be explained. The ratio of (A) to (B) is from 70:3o to 95:5, preferably from 80:2o to 90:10.
It is. If (B) exceeds 30%, the excellent mechanical properties of copolymer A are impaired and the effects of the present invention cannot be obtained.

The mixing ratio of component (g) in the composition is 5% or more and less than 50%, preferably 10 to 30%.

By mixing within this range, moldability and film rigidity can be improved without impairing the characteristics of linear medium-low density polyethylene. If the amount of component (g) mixed is small, the effect of improving film formability etc. cannot be obtained, and if the amount mixed is 50% or more, the fluidity decreases'' - the appearance (transparency, etc.) of the molded product is completely impaired.

Next, the mixing ratio of (0) and (D), which are the constituent components of component (E), will be explained.

The ratio of (0) to (D) ranges from 30:70 to 80:20, preferably from 40:60 to 70:30. If (0) exceeds 80 or (D) exceeds 70, good physical properties and moldability cannot be obtained.

The method of mixing the three components (A), (B) and (E) is (
A).

(B) A method of mixing and kneading (0) and (D) at the same time, adding (A) to a mixture of (0) and (D) in advance.
) and (B) may be mixed and kneaded in succession, or any combination or order of mixing may be used.

The copolymer (A), low-density polyethylene (B), and high-medium density polyethylene (E) (or (0) and (D)) are mixed in a molten state using an ordinary extruder or mixer under ordinary conditions. It will be held in The extruder may be either a single screw type or a double screw type, and examples of the double screw type include the Japan IL! ! OIM for steel works, etc.
FOM, D8M, etc. manufactured by Parrel Corporation can be used, and as the crosstalk device, for example, a Nogino Lee mixer can be used.

It is of course possible to mix into the compositions of the invention customary stabilizers, lubricants, anti-sanding agents, pigments, inorganic or organic fillers. Examples of these additives include BHT
, Shell Ionox 3301 Gutdrich Gutdry) 3114. , Tinuvin 327, Sankyo Pharmaceutical Co., Ltd.'s Nord LS77QDM'rDP DLTDP, , Calcium stearate, Lead stearate, Titanium White, Calcium carbonate, Cargin! Examples include racks and the like.

The invention will be described below with reference to Examples, but the invention is not limited in any way by these Examples.

The meanings of terms used in the Examples are as follows.

(1) Molecular weight (MW): using decalin solution, 135°C
Intrinsic viscosity [η] measured by
6.8 X l □' MWo, MW was determined from 67.

(11) Density: Measured according to ASTM D-1505.

(iii) M,r; represents melt index, according to A8TMD-1238, temperature 190°C load 2.
Measurements were made under 16 to 9 conditions.

+IV) Melt tension = 190 by flow tester
The melt tension is defined as the tension when the strand is extruded at a temperature of 0.6 crn/- at a temperature of 0.6 crn/- and the strand is stretched at l Q m/mr.

(■) Tensile impact strength: Measured according to ASTM D-1822.

(V-core film tensile customization: ASTM D-88
Measured according to 2.

Axis Film dart impact: ASTM D-1709
Measured according to

(liii) Film tear strength: ASTM
Measured according to D-1922.

GX) Haze: ASTM D-10
Measured according to 03-61.

(1) Solid catalyst Human trichlorosilane (H8+ OIg) 1 mol 1°C hexane solution 2I! , into an 81 autoclave,
It was kept at 50°C. This has a composition of AlMg6. . (02H,
Enter.

(n 04H1l)11. ! + (004H,)s,
1 mol of organoaluminium-magnesium complex of s 12
2 ρ of hexane solution was added dropwise over 2 hours with stirring, and the reaction was further allowed to proceed at this temperature for 2 hours. The produced solid component was washed twice with hexane at 2° C. by the precipitation method. 22 titanium tetrachloride was added to the slurry containing this solid component, and 1
After reacting for 2 hours at 30°C, the solid catalyst was isolated and washed with hexane until no free halogen was detected. This solid catalyst vi contained 2.1% titanium.

(2) Solid catalyst (B) After removing oxygen and moisture inside the autoclave with dry nitrogen, a 1.6°C hexane solution of trichlorosilane 70, 4 moVρ and 1.2 A of hexane were charged, and the temperature was raised to 70°C. . Next, A I□, 15 Mg (n
-Bu)1.75(0-nBu)6. , (octane solution with metal concentration 0, 9' mol/j!) 0.5
5fi and Hexa 70.351 were added at 70'C over 1 hour. The sample contained 0.7 p of titanium tetrachloride.

In addition, AIo, 15 Mg (rl-Bu)l, 75
(0-nBu). , 7 was manufactured in Japanese Unexamined Patent Application Publication No. 1986-57.
According to Publication No. 09.

(3) Manufacturing reaction volume of high and medium density polyethylene (0) and Φ) 200! Polyethylene was produced by continuous loading using a stainless steel polymerization machine. The polymerization temperature was 86°C, the polymerization pressure was 12 Kg/cm2G, and the polymerization was controlled so that the production amount was 8 Ky/hr.

The catalyst was triethylaluminum at 0.5 mmol.
/Il, the amount of polymerization produced by solid catalyst A is 8.
It was introduced with hexane at 30°C/Hr so that the odor/Hr. Hydrogen was used as a molecular weight regulator. High molecular weight ethylene (C) has a molecule of -n 4800 o o
The gas phase composition was adjusted so that The hydrogen concentration was approximately 13%, and the catalyst efficiency was 780,000 polymers 1 yTi. Low molecular weight polyethylene (D) has a molecular weight of 24,000
Polymerization was carried out so that The hydrogen concentration was approximately 73%, and the catalyst efficiency was 110,000 liters of polymer 1yTi.

(4) Production of ethylene-α olefin copolymer 20
Polymer production was carried out under continuous polymerization conditions using a reactor with a container of No. 01. Solvent is hexane f 5042 /H
r, the number of pyrimers produced from ethylene is 6 to 10 Kf/H
The solid catalyst (B) produced in the above (1) was supplied in an amount necessary to maintain the temperature at 0.1 to 0.25 p/Hr, and the triethylaluminum was supplied in an amount of 2.0 to 3.0 p/Hr. Ommol/Hr
, hydrogen 10-8θIt/Hr, α-onfin 3.0-6.0Ky/Hr, polymerization temperature 130-220
Copolymers 1 to 4 shown in Table 1 were produced by changing the temperature within the range of °C.

(5) Film forming conditions Molding machine: Air-cooled blown film device manufactured by Modern Machinery Co., Ltd. Extrusion machine: Modern Mannery 50 ■ φ Delcer molding material: Extrusion temperature 180℃ Die 125 mm φ Snow ξ Iral die gear knob 2゜0 Blow ratio 2.0 70 line height 50 c1n discharge! 20 K9/Hr take-up 9-speed If
9 m 1 minute film thickness 50μ Example 1 High-medium density polyethylene (0
) and (D) were mixed in a ratio of 55/2, and kneaded and extruded with Irganoc 5, 1076, 1000 ppm, and calcium stearate 1000 ppm in a twin-screw extruder at 200°C to form pellets and produce component (E). M,
I is 0.06 yz' lQ+ain, density is 0.95
It was 3777cm3.

Copolymer (A) 41 produced in (4) and M, Is, o
y/1om+density 0.91897cm" high pressure polyethylene (Asahi Dow MM-1850A) at a weight ratio of 85/
Further, 15 wt% of the above component CF3) was added to this 5, and the mixture was mixed with 1000 ppm of Irganox 1076 and 1000 ppm of calcium stearate using an extruder with a diameter of 65 mm.
Kneading and extrusion were performed at ℃ to obtain pellets. Table 2 shows the custom values of this composition and the characteristic values of the film formed under the film forming conditions (5).

Examples 2 to 4 Copolymer (^), high pressure polyethylene (B) and component (
The same experiment as in Example 1 was conducted except that the mixing ratio of B) was changed as shown in Table 2, and the results shown in Table 2 were obtained.

Examples 5 to 7 The same experiments as in Example 1 were conducted except that the copolymer (A) was changed to Il6-2 to Il6-4, and the results shown in Table 2 were obtained.

Examples 8 to 9 High-pressure polyethylene was M and I, respectively. 2. Oy, /1
0 minute density 0.91897cm” (Asahi Dow M-182
0) and M, I2.3F/10 min density o, 5aoP/Bi3 (QO951 manufactured by Asahi Dow), and Example 5, respectively.
, and an experiment similar to Example 6 was conducted to obtain the results shown in Table 2.

Comparative Examples 1 to 3 Table 2 shows the results of evaluating each of the copolymers (A) it~/I63 individually.

Comparative Example 4 Copolymer (A) Ma 3 and M, I 5,07/10 min density 0
．． 918y/cm” high pressure polyethylene (Asahi Dow H
M-185OA) at a weight ratio of 85/15,
Irganox 1076 1000 ppm and calcium stearate 1000 ppm were kneaded and extruded at 230°C in an extruder with a diameter of 65 bars to obtain pellets. Table 2 shows the results of evaluating this composition in the same manner as in Example 1.
It was shown to.

Comparative Example 5 15 wt% of the high-medium density polyethylene (E) used in Example 1 was added to copolymer (A) 41, and the mixture was mixed with 1000 ppm of Irganox 1076 and 1000 ppm of calcium stearate using a 65 wmφ extruder.
Pellets were obtained by kneading and extrusion at 0°C.

This composition was evaluated in the same manner as in Example 1, and the results are shown in Table 2.

As can be seen from the results of the practical examples and comparative examples, only the blend composition according to the present invention containing a specific range of specific components can produce a film with a good balance without impairing any of the formability, rigidity, strength, and transparency of the film. You can see what you can get.

j kushita margin

Claims (1)

[Scope of Claims] (1) A copolymer of ethylene and an α-olefin having 4 to 12 carbon atoms (
A), melt index is o, t~20y/lO min,
High-pressure polyethylene (B) having a density of 0.910 to 0.93517 cm" and (E) a homogeneous melt mixture consisting of high-molecular weight high-medium density polyethylene (0) and low-molecular weight high-medium density polyethylene (D) A composition comprising: (i) (c) has an average molecular weight of 100,000 to 1 million;
The average molecular bone of (D) is θ, 10,000 to 100,000, and (0)
(D) molecular weight ratio y15 to 200, (ii)
The mixing ratio of (A), (B) and (E) is (A)
(El) is from 70:30 to 95:5, and the mixing ratio of (g) in the composition is 5% by weight or more.
4, the mixing ratio of (0) and (D) is from 30:70 to 80:20, and the melt index of the composition after homogeneous melting and mixing is 0.1 to 5y/lO, and the density is 0.920-0.9
Ethylene-based resin composition with excellent mechanical properties, transparency, and moldability (2) Polymer experimental component (0)
has an average molecular weight of 300,000 to 800,000, a low molecular weight component (D) has an average molecular weight of 0.5 to 50,000, and the molecular ratio of (0) to (D) is 10 to 100. The composition according to claim 1 (3) The composition according to claims 1 and 2, wherein the ethylene resin composition is suitable for film forming (4) Copolymer (A) The composition according to claims 1 to 3, wherein the α-olefin used in the scent is butene-1.