Butene-1 terpolymers and process for their preparation

Abstract

Butene-1 terpolymers having a content of propylene derived units of 0.5-13% mol, and a content of ethylene derived units of 1-3% mol, a ratio C3/C2 of the content of propylene and ethylene derived units is of from 1 to 10, said butene-1 terpolymers having a melt flow rate MIE, measured at 190 C./2.16 Kg of from 0.3 to 3 g/10 min, and a molecular weight distribution curve determined by GPC with a ratio Mw/Mn of from 4 to 10, and the portion of molecular weights of 110.sup.5 or lower, accounting for 22% or larger of the total area.

Claims

1. A butene-1 terpolymer comprising: (A) a propylene content of 0.5-13 mol %; (B) an ethylene content of 0.5-3 mol %; (C) a C.sub.3/C.sub.2 molar content ratio of propylene to ethylene of 1-10; (D) a melt flow rate (MIE; ISO 1133, 190 C., 2.16 kg) of 0.3-3 g/10 min; (E) a molecular weight distribution curve (Mw/Mn, determined by GPC) of 4-10, where a portion of molecular weights of 110.sup.5 or lower is at least 22% of the total area of the molecular weight distribution curve; and (F) a xylene solubility at 25 C. of over 5 wt % to 7.5 wt %.

2. The butene-1 terpolymer of claim 1, comprising: (A) 40-60% by weight of a first polymer composition comprising: (i) 0.5-13 mol % propylene, and (ii) 0.5-3 mol % ethylene, wherein the first polymer composition has a melt flow rate, measured at 190 C./21.6 kg, of 10-45 g/10 min; and (B) 60-40% by weight of a second polymer composition selected from the group consisting of (i) a copolymer of butene-1 and propylene comprising: 97-99.5 mol % of butene-1 derived units, and 0.5-13 mol % of propylene derived units, and (ii) a copolymer of butene-1, propylene and ethylene comprising: 0.5-13 mol % of propylene derived units, and 0.5-3 mol % of ethylene derived units, wherein the second polymer composition has a melt flow rate (MIE, ISO 1133, 190 C., 2.16 kg) of 0.5-10 g/10 min.

3. A manufactured article comprising the butene-1 terpolymer of claim 2.

4. The manufactured article of claim 3, wherein the article is a pipe.

5. A process for the preparation of the butene-1 polymer composition of claim 2, comprising copolymerizing butene-1, ethylene and propylene in the presence of a stereospecific catalyst comprising (A) a solid catalyst component comprising a Ti compound and an internal electron donor compound supported on MgCl.sub.2; (B) an alkylaluminum compound; and (C) an external electron donor compound comprising thexyltrimethoxysilane, wherein the process is carried out in liquid butene-1.

6. The process of claim 5 in which the co-polymerization is carried out in at least two reactors operating under the same or different reaction conditions selected from the group consisting of molecular weight regulator concentration, comonomer concentration, temperature, pressure and combinations thereof.

Description

EXAMPLES

(1) Preparation of Solid Catalyst Component

(2) Into a 500 ml four-necked round flask, purged with nitrogen, 225 ml of TiCl.sub.4 were introduced at 0 C. While stirring, 6.8 g of microspheroidal MgCl.sub.2.2.7C.sub.2H.sub.5OH (prepared as described in Ex. 2 of U.S. Pat. No. 4,399,054 but operating at 3,000 rpm instead of 10,000) were added. The flask was heated to 40 C. and 4.4 mmoles of diisobutylphthalate were thereupon added. The temperature was raised to 100 C. and maintained for two hours, then stirring was discontinued, the solid product was allowed to settle and the supernatant liquid was siphoned off.

(3) 200 ml of fresh TiCl.sub.4 were added, the mixture was reacted at 120 C. for one hour then the supernatant liquid was siphoned off and the solid obtained was washed six times with anhydrous hexane (6100 ml) at 60 C. and then dried under vacuum. The catalyst component contained 2.8 wt % of Ti and 12.3 wt % of phthalate.

Examples 1-2 Preparation of Butene-1/Propylene/Ethylene Copolymers (Terpolymers) by Sequential Copolymerization

(4) In examples 1-2 the sequential polymerization was carried out after a precontacting step, in two liquid-phase stirred reactors (R1, R2) connected in series in which liquid butene-1 constituted the liquid medium. During the precontacting step the solid catalyst component, the Al-Alkyl compound TIBAL (i.e. triisobutylaluminum) and the external donor thexyltrimethoxysilane were pre-mixed under the conditions reported in table 1. The catalyst system was injected into the first reactor working under the conditions reported in table 1.

(5) After the first polymerization step the content of the first reactor was transferred into the second reactor where the polymerization continued under the conditions reported in the same table 1. The polymerization was stopped by killing the catalyst and transferring the polymerized mass in the devolatilization step.

(6) A detailed description of the process is found in the International Patent Application WO04/000895.

(7) The results of the characterization carried out on the obtained terpolymers are reported in Table 1b.

Comparative Example 1 (1C): Butene-1/Ethylene Copolymer

(8) The polymerization was carried out as in example 1 and 2 under the conditions reported in the same Table 1.

(9) The characterization of the copolymer is reported in Table 2.

Comparative Example 2 (2C): Butene-1 Homo-Polymer

(10) A commercial Butene-1 homopolymer grade produced by Basell under the trade name PB0110M having a melt flow rate value (MIE measured at 190 C. and 2.16 Kg) of 0.4 g/10 min, density 0.914 Kg/dm.sup.3. The properties of the polymer were measured for comparison purpose and reported in Table 2.

(11) It is evident from the examples and the comparative examples the role of the comonomer (i.e. ethylene and propylene) and their amount to target properties that are not simply due to a large molecular weight distribution (comparative 2c) nor are obtainable without the presence of both ethylene and propylene as comonomers (comparative 1c).

(12) TABLE-US-00001 TABLE 1 Polymerization Process EXAMPLES 1C 1 2 PRECONTACTING temperature C. 9 9 9 Al-Alkyl/donor g/g 76 86 84 Al-Alkyl/catalyst g/g 87 92 100 POLYMERIZATION First reactor temperature C. 70 70 70 C4-reactor feed g/h 132000 135000 118000 C3-reactor feed g/h no 1480 940 C2-reactor feed g/h 250 250 170 H2 reactor feed g/h 1.4 1.25 1.08 Residence time min 89 88 99 C3-BONDED % wt 3.36 3.46 C2-BONDED % wt 0.5 0.6 0.8 split % wt 50 50 50 MIE g/10 min 0.19 0.17 0.15 MIF g/10 min 44.8 40.1 35.9 Second reactor temperature C. 75 75 75 C4-reactor feed g/h 25000 25000 25400 C3-reactor feed C3 (g/h) no 300 500 C2-reactor feed C2 (g/h) no no 110 H2 reactor feed H2 (g/h) 21.7 18 14 Residence time (min) 76 75 83 split % wt 50 50 50 MIE (calculated) 9 14 15 ADDITIVE Irganox 10120/ ppm 453 781 663 Irganox 1070 (70:30)

(13) TABLE-US-00002 TABLE 2 Final polymer structure and properties EXAMPLES 1C 1 2 2C C3-BONDED % wt 2.76 2.6 C2-BONDED % wt 0.5 0.55 0.8 C3-BONDED % mol 3.3 3.1 C2-BONDED % mol 1.2 1 1.2 C3/C2 mol ratio 3.3 2.5 C3/C2 wt ratio 5.01 3.25 Tm(II) C. 109 104 99 117 Tm(I) 122 117 113 128 xilene soluble % wt 2.25 6.5 6.7 2.01 fraction I.V. of xylene- dl/g 1.99 1.96 2.04 2.3 soluble fraction MIE g/10 min 0.91 0.9 0.8 0.4 (190 C./2.16 Kg) MIE 0.9 1 0.95 Finale PI 7.8 7.3 7.1 7.2 Mw/Mn 6.2 6 5.6 5.6 % Area GPC 26.6 25.8 23.4 23.7 Below 1 10.sup.5 Density Kg/dm.sup.3 0.9096 0.9083 0.9064 0.914 Flexural Modulus* MPa 327 300 281 450 Strength at Yield MPa 19 17.9 18.1 19.5 Strength at Break MPa 37.2 35.9 39.6 35 Elongation at Break % 340 360 370 300 Isteresi parameter E.sub.total Joule 0.0056 0.01 0.0048 0.0072 E.sub.absorbed Joule 0.0011 0.001 0.0008 0.0018 E.sub.released Joule 0.0045 0.0048 0.004 0.0054 hystresis parameter Ratio 19.691 17.259 16.582 24.576 *after aging 10 min in autoclave