JP3360862B2 - Soft olefin polymer composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft olefin polymer composition, and more particularly to a soft olefin polymer composition containing a propylene / 1-butene random copolymer having improved low temperature impact resistance as a main component. .

[0002]

2. Description of the Related Art Propylene / 1-butene random copolymers are low density polyethylene, ethylene / propylene copolymers, ethylene / vinyl acetate copolymers, soft vinyl chloride resins and other soft plastics. It is an alternative to vulcanized rubber because it has excellent properties such as heat resistance, scratch resistance, and abrasion resistance, as well as good flexibility, elastic recovery, transparency, low-temperature heat sealability, and impact resistance. , General packaging film, shrink wrapping film and polypropylene film have been proposed for use as heat seal layers.

[0003]

However, the propylene / 1-butene random copolymer has a drawback that it is inferior in impact strength at low temperature.

Therefore, an object of the present invention is propylene.
Provided is a soft olefin polymer composition having improved low-temperature impact resistance without impairing the excellent properties of butene random copolymer such as flexibility, elastic recovery, abrasion resistance, scratch resistance, and heat resistance. To do.

[0005]

In order to solve the above-mentioned problems, the present invention has a propylene content of 55 to 85 mol%, a heat of fusion of 2 to 80 Joule / g and an intrinsic viscosity of 0.02.
Ethylene polymer having an ethylene content of 50 mol% or more and a crystallinity of 60% or less with respect to 95 to 50 parts by weight of a propylene / 1-butene random copolymer (A) of 0.7 dl / g (B ) 5 to 50 parts by weight of a soft olefin polymer composition is provided.

It is preferable that the ethylene-based polymer (B) is an ethylene / propylene random copolymer having an ethylene content of 60 to 95 mol%.

It is preferable that the ethylene-based polymer (B) is an ethylene / 1-butene random copolymer having an ethylene content of 60 to 90 mol%.

The ethylene / 1-butene random copolymer has an ethylene content of 75 to 92 mol% and a crystallinity of 3 to
A 25% ethylene / 1-butene random copolymer is preferred.

The soft olefin polymer composition of the present invention will be described in detail below.

The propylene / 1-butene random copolymer (A), which is the main component of the soft olefin polymer composition (hereinafter abbreviated as "composition") of the present invention, contains a repeating structural unit derived from propylene. , A repeating structural unit derived from 1-butene is a copolymer randomly distributed in the molecular chain.

The propylene content of the propylene / 1-butene random copolymer (A) is such that a composition having a melting point in an appropriate range, excellent heat resistance and good flexibility can be obtained. 55 to 85 mol%, preferably 6
It is 5 to 83 mol%, and particularly preferably 70 to 80 mol%.

The heat of fusion of crystals of the propylene / 1-butene random copolymer is excellent in heat resistance, abrasion resistance and scratch resistance, and is also excellent in flexibility, elastic recovery and low temperature heat sealability. 20 from the point of getting things
80 Joule / g, preferably 30-70 Joule / g
g, and more preferably 20 to 80 Joule / g. This heat of crystal fusion is an amount related to the crystallinity of the polymer, and the specific heat curve in the completely melted state of the copolymer by a differential scanning calorimeter (preferably the specific heat curve shown at 160 ° C or higher and 240 ° C or lower) It is a value obtained by using a straight line obtained by extrapolating directly to the low temperature side as a baseline. Further, the melting point or the heat of fusion is determined by leaving the sample at 200 ° C. for 5 minutes,
Cool down to -40 ° C at a cooling rate of 10 ° C / min, -4
Let stand for 5 minutes at 0 ° C. After that, the measurement is performed under the measurement condition of increasing the temperature from −40 ° C. to 200 ° C. at a temperature increasing rate of 20 ° C./min.

Furthermore, the intrinsic viscosity [η] of the propylene / 1-butene random copolymer (A) is 0.02 to 0.7 in that it has good compatibility with the ethylene copolymer.
dl / g, preferably 0.1 to 0.7 dl / g
Is. This intrinsic viscosity [η] is a value measured in decalin at 135 ° C.

This propylene / 1-butene random copolymer (A) can be produced, for example, by (a) a composite containing at least magnesium, titanium and halogen,
It can be carried out by a method of randomly copolymerizing propylene and 1-butene using a catalyst composed of (b) an organometallic compound of a metal element of Groups 1 to 3 of the periodic table and (c) an electron donor. it can. Part or all of the electron donor (c) may be fixed to part or all of the composite (a), or may be pre-contacted with the organometallic compound (b) prior to use. Good. Particularly preferred is a mode in which a part of the electron donor (c) is fixed to the composite (a), and the rest is added to the polymerization system as it is, or pre-contacted with the organometallic compound (b). It is a catalyst. With such a catalyst system, a copolymer with less methyl acetate solubles is obtained. in this case,
The electron donor fixed to the composite (a) may be the same or different from the electron donor used as it is in the polymerization system as it is or in pre-contact with the organometallic compound (b). May be.

In the above polymerization reaction, a propylene / 1-butene random copolymer having a desired molecular weight can be obtained by appropriately selecting the polymerization conditions such as the polymerization temperature and the use ratio of the catalyst component. Adding hydrogen to the polymerization system is effective in controlling the molecular weight. Particularly, propylene having an intrinsic viscosity [η] of 0.02 to 0.7 dl / g.
In order to obtain a 1-butene random copolymer, it is effective to add a large amount of hydrogen.

Further, propylene-1 used in the present invention
-The butene random copolymer (A) may be directly produced by the above-mentioned polymerization reaction, but by the above-mentioned polymerization reaction, first,
After producing a propylene / 1-butene random copolymer having an intrinsic viscosity higher than a desired range, for example, an intrinsic viscosity [η] of 1 to 6, the propylene / 1-butene random copolymer is thermally decomposed to obtain an ultimate viscosity. Viscosity [η] is 0.02 to 0.7
A dl / g propylene / 1-butene random copolymer (A) can also be produced. According to this method by thermal decomposition, compared with the method of directly producing by polymerization reaction,
There is an advantage that a desired propylene / 1-butene copolymer can be obtained with high yield and high efficiency. This thermal decomposition is carried out in an inert atmosphere such as nitrogen in a propylene having an intrinsic viscosity higher than a desired range, for example, an intrinsic viscosity [η] of 1 to 6
It can be carried out by a method of thermally decomposing the 1-butene random copolymer. The temperature of thermal decomposition is 360 to 43.
The temperature is 0 ° C, preferably 380 to 410 ° C. Further, the method of thermal decomposition is propylene having an intrinsic viscosity [η] of 1 to 6
1-butene random copolymer is fed to the extruder, heated,
Method of thermally decomposing while kneading and extruding; method of charging a propylene / 1-butene random copolymer having an intrinsic viscosity [η] of 1 to 6 dl / g into a thermal decomposition reactor and thermally decomposing while stirring in a batch system. And so on.

Examples of the ethylene polymer which is the component (B) of the composition of the present invention include ethylene homopolymers and copolymers of ethylene and a monomer copolymerizable with the ethylene. Examples of the monomer copolymerizable with ethylene include propylene, 1-butene, 1-pentene,
Α-Olefins such as 1-hexene, 1-octene and 4-methyl-1-pentene; conjugated dienes such as ethylidene norbornene, dicyclopentadiene and 1,4-hexadiene; vinyl acetate, methyl (meth) acrylate, (meth )
Examples thereof include saturated or unsaturated carboxylic acid esters such as ethyl acrylate; maleic anhydride and derivatives thereof, and these may be used alone or in combination of two or more. Specific examples of the ethylene polymer include low density polyethylene; ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 1-pentene copolymer, ethylene / 1-hexene copolymer, ethylene. -Ethylene / α-olefin copolymers such as 1-octene copolymer and ethylene-4-methyl-1-pentene copolymer; ethylene / propylene / ethylidene norbornene copolymer, ethylene / propylene / dicyclopentadiene copolymer Copolymers, ethylene / α-olefin copolymers such as ethylene / propylene / 1,4-hexadiene copolymer; ethylene / vinyl acetate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer And so on.

The ethylene content of the ethylene polymer (B) is 50 mol% or more, preferably 60 to 95 mol% from the viewpoint of obtaining a composition having good low temperature impact strength.

The ethylene-based polymer (B) has a crystallinity of 60% or less in that it has a good low-temperature characteristic and a rubber-like composition such as flexibility and elastic recovery. ,
It is preferably 20% or less. This crystallinity is a value measured by X-ray analysis.

Further, the melt index (190 ° C.) of this ethylene polymer (B) is usually 0.1 to 50.
It is about g / 10 minutes.

Among the ethylene polymers (B), a composition having an excellent effect of improving low temperature impact strength and an improved flexibility can be obtained by adding a small amount of the composition to the composition. Ethylene with an ethylene content of 60 to 95 mol%
1-butene random copolymer, ethylene content 60-9
A 0 mol% ethylene / propylene random copolymer is preferred.

Further, among the ethylene / 1-butene random copolymers, a composition having improved low temperature impact strength can be obtained by blending it with the composition without lowering transparency and heat resistance. An ethylene / 1-butene random copolymer having an ethylene content of 75 to 92 mol%, a density of 0.87 to 0.90 g / cm ³ , a melting point of 60 to 90 ° C. and a crystallinity of 3 to 25% is particularly preferable.

Propylene 1- in the composition of the present invention
The blending ratio of the butene random copolymer (A) and the ethylene polymer (B) is such that the low temperature impact resistance is sufficiently improved, and the propylene / 1-butene random copolymer has excellent performances such as heat resistance and abrasion resistance. Of a propylene / 1-butene random copolymer (A) in an amount of 95 to 50% by weight and an ethylene polymer in an amount of 5 to 50% by weight, in terms of obtaining a composition having excellent properties, scratch resistance and flexibility. Is 90 to 70% by weight of propylene / 1-butene random copolymer (A)
On the other hand, it is 10 to 30% by weight of the ethylene polymer (B).

In the composition of the present invention, in addition to the propylene / 1-butene random copolymer (A) and the ethylene polymer (B), if necessary, known heat stabilizers and ultraviolet absorbers can be used. You may mix | blend various compounding agents, such as an agent, an anti-blocking agent, a pigment, a dye, a filler, a lubricant, a slip agent, an antistatic agent, and a flame retardant.

The composition of the present invention can be produced by a conventional method and is not particularly limited. For example,
The propylene / 1-butene random copolymer (A) and the ethylene polymer (B) and, if necessary, the above compounding ingredients were mixed using a mixer such as a V-type blender, a tumbler mixer, a Henschel mixer. After that, it can be produced by supplying to an extruder, a kneader, a Banbury mixer or the like and kneading.

The composition of the present invention can be suitably applied to applications in which vulcanized rubber and soft vinyl chloride resin are used. For example, automobile parts such as bumper parts and side seals; footwear such as shoe soles and sandals; electric parts such as electric wire coatings, connectors and cap plugs; golf club grips, baseball bat grips, gaskets, waterproof cloths, garden hoses, belts, etc. Molded products; hoses, sheets, etc .; or various films such as general packaging film, food packaging film, frozen food packaging film, retort food packaging film, shrink packaging film, stretch film, protect film, or the like, or Examples thereof include applications of various composite films such as easily heat-sealable biaxially oriented polypropylene film and flexible containers such as mayonnaise and ketchup.

[0027]

EXAMPLES Examples and comparative examples of the present invention will be given below.
The present invention will be specifically described, but the present invention is not limited to these examples. Moreover, in the following, the physical properties of the press sheet were evaluated according to the following methods.

Tensile properties It was measured according to the method of JIS K6301.

Spring hardness was measured using a type A and type D durometer according to the method of ASTM D2740.

Torsional rigidity According to the method of JIS K6301, the temperature was measured at 23 ° C, 0 ° C and -10 ° C.

Permanent elongation It was measured according to the method of JIS K6301.

Scratch strength A pencil hardness tester manufactured by Toyo Seiki Co., Ltd.
The width of the scratches when the sample was scratched was measured under the respective loads of 00 g and 300 g, and shown in units of 1 / mm.

Amount of taper wear Using a taper wear tester, set the cs-17 wheel to 1
The amount of wear reduction of the sample was measured when the sample was rotated 1000 times under a load of 000 g.

Heat-deformation resistance One end of a sample having a length of 100 mm, a width of 20 mm and a thickness of 2 mm was fixed by a cantilever method, and the free end of the other free end after 1 hour was adjusted to 80 ° C. and 100 ° C. The value (mm) obtained by measuring at each temperature and subtracting the amount of sagging at 23 ° C. was obtained as an index of heat distortion resistance.

Low temperature embrittlement temperature It was measured according to the method of JIS K6301.

(Example 1) [Production of propylene / 1-butene random copolymer] 200 g of anhydrous magnesium chloride, 46 ml of ethyl benzoate
Then, 30 ml of methyl polysiloxane and 30 ml of methyl polysiloxane were charged into a ball mill, kneaded in a nitrogen atmosphere, and then added to titanium tetrachloride to prepare a suspension. The solid content obtained by filtering this suspension had a titanium concentration of 0.01 mmol / l.
So that the concentration of triethylaluminum in the polymerization vessel is 1.0 mmol / l, and the concentration of methyl p-toluate is 0.33 mmol / l in the polymerization vessel.
So as to be charged into a stainless steel polymerization vessel having an internal volume of 20 l equipped with a stirrer, and n-heptane as a polymerization solvent, mixed gas of propylene and 1-butene (70 mol% of propylene, 30 mol of 1-butene). %) 4k / h
It was supplied at a flow rate of 1 and a copolymerization reaction was carried out at 70 ° C. The nuclear magnetic resonance spectrum of the obtained propylene / 1-butene random copolymer was measured to determine the propylene content, which was 77.6 mol%. Further, the melting point, the heat of fusion, and the intrinsic viscosity [η] were measured to be 116 each.
C., 56 Joule / g, 2.00 dl / g.

[Thermal Decomposition of Copolymer] The propylene / 1-butene copolymer obtained above was fed to a twin-screw extruder (screw diameter: 30 mmφ), and 400 rpm and 25 rpm.
It was thermally decomposed while being extruded at the screw rotation speed of.
When the intrinsic viscosity [η] of the obtained pyrolyzed propylene / 1-butene copolymer was measured in decalin at 135 ° C.,
It was 0.4 dl / g.

[Preparation of Composition] 20 parts by weight of a pyrolyzed propylene / 1-butene copolymer having an intrinsic viscosity [η] of 0.4 dl / g obtained above and ethylene / propylene rubber (ethylene content: 71 mol%, melt index (190 ° C.): 1.2 g / 10 minutes, crystallinity: 0%)
20 parts by weight (hereinafter, abbreviated as "EPR") is mixed with a tumbler blender for 10 minutes, then supplied to an extruder and extruded while kneading at a resin temperature of 210 ° C. to form an olefin polymer composition. Pellets were obtained.

The pellets of the obtained composition were press-molded at 200 ° C. to prepare a press sheet having a length of 10 cm, a width of 10 cm and a thickness of 3 mm. A sample piece was cut out from this press sheet and used for evaluation of each physical property. The results are shown in Table 1.

(Examples 2 and 3 and Comparative Examples 1 and 2) A composition was prepared in the same manner as in Example 1 except that the compounding ratio of PBC and EPR was as shown in Table 1, and the composition was further prepared. A press sheet was prepared from and used for evaluation of each physical property. The results are shown in Table 1.

[0041]

[Table 1]

(Examples 4 to 6 and Comparative Examples 3 to 4) Example 1
A composition was prepared in the same manner as in Example 1 except that the propylene / 1-butene copolymer obtained by changing the compounding ratio of propylene and 1-butene as shown in Table 2 was used instead of the PBC used in 1. Was prepared, and a press sheet was prepared from the composition, and the physical properties were evaluated. The results are shown in Table 2.

[0043]

[Table 2]

Example 7 Instead of EPR, an ethylene / 1-butene random copolymer (melt index (190 ° C.): 4.0 g / 10 minutes, ethylene content: 9)
0 mol%, density: 0.885 g / cm ³ , crystallinity: 1
7%, melting point: 71 ° C.) (hereinafter abbreviated as “EBC”), a composition was produced in the same manner as in Example 1, and a press sheet was prepared from the composition to evaluate each physical property. I went to The results are shown in Table 3.

Example 8 Instead of EPR, an ethylene / vinyl acetate copolymer (melt index (190
C.): 35 g / 10 min, vinyl acetate content: 10% by weight, crystallinity: 32%) (hereinafter abbreviated as “EVA”) except that a composition was produced in the same manner as in Example 1. ,
Further, a press sheet was prepared from the composition and used for evaluation of each physical property. The results are shown in Table 3.

Comparative Example 5 Instead of EPR, high density polyethylene (melt index (190 ° C.): 6.5)
g / 10 min, crystallinity: 77%), a composition was produced in the same manner as in Example 1, and a press sheet was prepared from the composition, and the physical properties were evaluated. The results are shown in Table 3.

Comparative Example 6 EVA alone used in Example 8 was molded into a press sheet in the same manner as in Example 1 and subjected to evaluation of various physical properties. The results are shown in Table 3.

(Comparative Example 7) High-pressure low-density polyethylene (melt index (190 ° C): 2.3 g / 10)
Min., Crystallinity: 56%) was molded into a press sheet in the same manner as in Example 1 and evaluated for each physical property. The results are shown in Table 3.

[0049]

[Table 3]

[0050]

The soft olefin polymer composition of the present invention has excellent flexibility, elastic recovery, abrasion resistance, scratch resistance, heat resistance and low temperature heat which a propylene / 1-butene random copolymer has. While maintaining the sealability,
It has improved low temperature impact resistance. Therefore, the composition of the present invention has been used in fields where vulcanized rubber, soft vinyl chloride resin and the like have been conventionally used, for example, automobile parts such as bumpers and side seals; footwear such as shoe soles and sandals; wire coatings, connectors, Electric parts such as cap plugs; grips for golf clubs, grips for baseball bats, various molded products such as gaskets; waterproof cloth, sprinkling hoses, hoses such as belts, use as sheets; and by combining with other films, Films such as general packaging film, food packaging film, frozen food packaging film, retort food packaging film, shrink packaging film, stretch film and protect film; various composite films such as heat-heat sealable biaxially oriented polypropylene film Uses: For flexible containers such as mayonnaise and ketchup It can be suitably used.

Continuation of the front page (56) Reference JP-A-3-66737 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 23 / 00-23 / 36

Claims (4)

(57) [Claims] 1. A propylene content of 55 to 85 mol%, a heat of fusion of 2 to 80 Joule / g, and an intrinsic viscosity of 0.02 to 0.
Ethylene polymer (B) 5 having an ethylene content of 50 mol% or more and a crystallinity of 60% or less with respect to 95 to 50 parts by weight of a propylene / 1-butene random copolymer (A) of 7 dl / g. A soft olefin polymer composition comprising ˜50 parts by weight. 2. The soft olefin polymer composition according to claim 1, wherein the ethylene polymer (B) is an ethylene / propylene random copolymer having an ethylene content of 60 to 95 mol%. 3. The soft olefin polymer composition according to claim 1, wherein the ethylene polymer (B) is an ethylene / 1-butene random copolymer having an ethylene content of 60 to 90 mol%. 4. The ethylene / 1-butene random copolymer has an ethylene content of 75 to 92 mol%, and a crystallinity of 3 to 3.
The soft olefin polymer composition according to claim 3, which is a 25% ethylene / 1-butene random copolymer.