JPH0425514A - Crystalline propylene copolymer and its production - Google Patents

Abstract

PURPOSE:To obtain a syndiotactic propylene copolymer of good processability by copolymerizing propylene with a specified alkadiene in the presence of a specified catalyst. CONSTITUTION:Propylene is copolymerized with a 6-20C alkadiene having vinyl bonds at both terminals in the presence of a catalyst comprising a metallocene compound of the formula (wherein Cp is cyclopentadiene; Rn and R'm are each a 1-20C hydrocarbyl residue; R'' is a structural bridge between Cp rings; Me is Ti, Zr or the like; Q is 1-20C hydrocarbyl or halogen; 0<=k<=3; 0<=n<=4; and 1<=m<=4) and a promoter. Thus, the title copolymer comprising propylene and the alkadiene, wherein the intensity of a peak observed at about 20.2ppm with reference to tetramethoxysilane in <13>C-NMR as measured in a 1,2,4- trichlorobenzene solution is 0.6 or above, the content of an alkadiene monomer units is 0.01-5mol%, and the intrinsic viscosity is 0.4-10dl/g as measured in a tetralin solution at 135 deg.C can be obtained. This copolymer is a syndiotactic propylene copolymer having improved melt viscoelasticity and good processability.

Description

Detailed Description of the Invention [Graduation Field of Application] The present invention relates to a novel crystalline propylene copolymer having a long chain branched structure and a method for producing the same [Prior Art] Nien et al. Invented geeky polypropylene and clarified its manufacturing method.

(JP-A-2-41303 and JP-A-2-41305)
This material is crystalline, has a high melting point, a high molecular weight, and has desirable physical properties for use as molded products, such as being transparent, soft, tough, and stretchable.

[Problem to be solved by the invention]

However, as a drawback, the syndioctic polypropylene obtained by the above-mentioned prior art process was found to be difficult to process.

In other words, when handling resin in the molten state, the same intrinsic viscosity (
When compared with the same weight average molecular weight (measured in tetralin solution at 135°C) or the same weight average molecular weight (measured with high temperature gel permeation chromatography), The viscosity is much higher than that of the tactile film (with a tactile coefficient of about 0.96), and the change in viscosity is small with respect to changes in the sliding speed.

this? When extruding the molten polymer from a die, the die swell is extremely small and the melt tension is also low, making it difficult to process using the processing methods normally used for polypropylene.

An object of the present invention is to provide a syndiotactic propylene copolymer with good processability and a method for producing the same.

[Means for Solving the Problems] In order to correct these drawbacks, we have discovered that a random copolymer of propylene and at least one alkadiene having 6 to 20 carbon atoms and having vinyl bonds at both ends is effective, and the present invention has been achieved. Reached.

An object of the present invention is to provide a novel crystalline propylene-based copolymer having improved melt viscoelastic properties, as well as a method for producing the above-mentioned thermoplastic resin.

According to the present invention, ii) propylene and at least one type having 6 to 20 carbon atoms;
Consisting of an alkadiene with vinyl bonds at both ends, +
The syndiotactic pentad fraction of the propylene chain measured by 3C-NMR is 0.6 or more, the content of the alkadiene monomer unit is in the range of 0.01 to 5 mol%, and the tetralin solution is heated at 135°C. 2) a crystalline propylene-based copolymer with an intrinsic viscosity measured in the range of 0.4 to 10 dfl/g, and 2) propylene and at least one alkadiene having 6 to 20 carbon atoms and having vinyl bonds at both ends, using the following formula. The metallocene compound R”(CpRn)(CpR′m)MeQk (where,
Each Cp is a cyclopentagenyl or substituted cyclopentagenyl ring; each Rn, which may be the same or different, is a hydrocarbyl residue having from 1 to 20 carbon atoms; each R'm is the same or may be different, is a hydrocarbyl residue having 1 to 20 carbon atoms, R'' is a structural bridge between the Cp rings that provides steric rigidity to the catalyst; Me is Ti, Zr or Hf; Each Q is a hydrocarbyl residue or halogen having 1 to 20 carbon atoms; 0≦k≦3; 0≦n≦4; l≦m≦
4; and R'm is (CpR'm) is (CpR
There is provided a method for producing a crystalline propylene copolymer, characterized in that the copolymerization is carried out by using a catalyst consisting of a cocatalyst (selected to be sterically different from n)) and a cocatalyst.

Hereinafter, propylene, alkadiene, copolymerization catalyst, and copolymerization method according to the present invention will be specifically explained.

The a/L4 casien used in the present invention has 6 to 2 carbon atoms.
An alkadiene having 0 vinyl bonds at both ends is used. This alkadiene can be used without any particular restrictions, whether it is linear or branched, as long as it has vinyl bonds at both ends.
Suitable examples include 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 1,11-dodecadiene, 1,13-tetradecadiene, and the like.

The alkadiene content in the copolymer of these monomers is preferably in the range of 0.01 to 5 mol%.

If the content is less than 0.01 mol%, the effects of the present invention cannot be achieved. In addition, if the content exceeds 5 mol%, the resulting polymer will contain a gel component with a highly branched structure, so the polymer will become partially insoluble in the solvent, and there will also be an infusible part even when heated. and has no industrial value.

When copolymerizing propylene and the above-mentioned alkadiene, it is preferable to make a small amount of ethylene present to form a multi-component copolymer, as this improves the copolymerizability of the alkadiene, and this is also included in the copolymers of the present application.

The catalyst used in the present invention is not particularly limited as long as it is a known catalyst that can polymerize propylene in a highly syndiotactic manner.

In the present invention, an alumoxane compound can be used as a metallocene compound and a cocatalyst.

The metallocene compound that can be used is a compound represented by the following formula: Preferably it is a cyclopentadienyl group; (CpR'm) is preferably a fluorenyl group or a 4,5-methylene-phenanthrenyl group; M8 is TiZr or Hf; Q is preferably is preferably a chlorine atom, a methyl group or a phenyl group; preferably 1 or 2.

Examples of particularly suitable compounds are isopropyl(cyclopentagenyl)(fluorenyl)zirconium dichloride, isopropyl(cyclopentagenyl)(fluorenyl)hafnium dichloride, isopropyl(cyclopentagenyl)(fluorenyl)titanium dichloride. Dichloride, isopropyl (cyclopentadienyl) (fluorenyl) zirconium dimethyl, isopropyl (
cyclopentagenyl) (fluorenyl) hafnium
Dimethyl, etc. These metallocene compounds are particularly preferably used in combination with alumoxane compounds as cocatalysts.

Examples of alumoxane compounds include compounds represented by the general formula R (in the formula, R represents a hydrocarbon residue having 1 to 3 carbon atoms), particularly methylalumoxane where R is a methyl group. is 5 or more, preferably 10 or more.

The ratio of alumoxane to the transition metal compound used is 10 to 1,000,000 times, usually 50 to 5,000 times.

Tetraphenylborate (e.g. tri(S-butyl)
The catalyst system disclosed in JP-A-1-502036 using ammonium tetra(p-tolyl) boron), and the catalyst system using 7,8-dicalhaundecafolane (13) as a cocatalyst as disclosed in JP-A 1-501950. May be used.

The polymerization method carried out in the present invention may be a slurry polymerization method using an inert hydrocarbon (for example, hexane, heptane, octane, toluene, etc.) or liquefied propylene as a solvent, or a so-called gas phase polymerization method.

The alkadiene is normally charged alone or together with propylene after the catalyst solution is charged into the polymerization machine, but there is no particular restriction.

The polymer obtained in the present invention is a crystalline propylene copolymer mainly composed of a sonodiotactic chain structure. Polypropylene with a highly syndiotactic chain structure was first discovered by Nien et al.
3).

Previously known syndiotactic polypropylene had a syndiotactic pentasotho fraction of 0.6 or less (Doi et al.: Macromolecules, 12
, 248 (1979); Makromol, chem.
, 186.2529 (1985); Zambelli et al.: Macromolecules, 1.750 (1
974)), and can the polymer be heated to n-hexane at 365°C? (Marchetti et al.; J, Poly
mer sci,, Polymer Physics
ed, 12.1949 (1979)), the melting point of the polymer is 65-131 °C (Boor et al.; Po
Lymer Letters, 3 577 (1965
)) is relatively low, and the number average molecular weight is 3.4X1.
0' (other than the above; Makromol, chem, 4
j15.1827 (1984) ) (This is 135
The intrinsic viscosity measured in °C tetralin solution is approximately 0.34
a/g].

If the intrinsic viscosity is less than 0.4, the polymer will be soft and wax-like, making it difficult to mold it alone, and if the intrinsic viscosity is more than 10, the melt viscosity will be too high to process with a normal molding machine. It becomes difficult.

The syndiotacticity of the present invention is 0 in Benhood fraction.
．． A polymer having an intrinsic viscosity of 6 or more and an intrinsic viscosity of 0.4 to 10 has excellent crystallinity, a melting point higher than that of polyethylene, can be heat-processed using a normal molding machine, and has the characteristics that the molded product is transparent and strong.

According to the present invention, a copolymer having a branched structure in which at least one terminal vinyl group of an alkadiene is copolymerized with propylene is provided. By adjusting the reaction conditions, it is also possible to copolymerize the remaining vinyl group with propylene to form a long chain branched structure. When using conventionally known Tigrana-Natsuta type catalysts (for example, titanium trichloride or titanium tetrachloride supported on magnesium chloride), the copolymerization of propylene and Nagahora Alkashun is extremely low;
Only some terpolymer was initially formed in the presence of ethylene.

The metallocene catalyst of the present invention has high copolymerizability with propylene of these alkadienes, and the composition distribution of the copolymer is uniform, making it possible for the first time to produce an industrially useful copolymer.

〔Example〕

Next, the present invention will be specifically explained using examples.

Melt index is ASTM D-1238 (JIS
K7210), 230℃ 1 load 2.16kg
The measurement was carried out under the following conditions using a nozzle with a diameter of 2.09 strokes and a length of 8 mm.

The die swell was determined as the ratio of the diameter of the extruded resin and the diameter of the nozzle when measuring the melt index.

Melt strength was measured by installing a resin winding device and a load cell for measuring tension in the melt index measuring device described above.

? 8 The viscoelasticity of the melt is measured using a Bohlin viscometer (Bohlin V
ORRheometer, Bohlin Reolo
(manufactured by Gia AB).

The syndiotactic pendant fraction was measured according to the method of Nien et al. (Japanese Unexamined Patent Publication No. 2-41303).

H-NMR measurement was carried out using 270MH2 using C6D6 as a solvent.
This was done using a spectrometer.

Example 1 20 mg of isopropyl (cyclopentagenyl) (fluorenyl) zirconium dichloride was added to an average polymerization degree of 17.
．． 20% toluene of methylaluminoxane with 7/
8 liquid (manufactured by Tosoh Axo Co., Ltd.) Total 3 with 14.4d
A catalyst solution was prepared by dissolving it in 5 mρ of toluene. After purging the 3j2 autoclave with nitrogen, pentane 12
and 0.60 g of 1,7-octadiene were charged, and the atmosphere in the system was replaced with propylene.

Add the above catalyst solution to 9.2 x 10-' mmol in terms of Zr atoms, and then add propylene to bring the inside of the system to 9 kg/c.
Copolymerization was carried out at 40'C for 1 hour while maintaining the temperature at fh (450 g of propylene was dissolved under these conditions). The reaction was stopped by adding 15 ml of isopropanol, and after cooling, the slurry was taken out and pentane l! Add, filter, and 1 more! After washing the cake with pentane, dry the powder and
49 g of polymer was obtained. Separately, the washing solvent was combined and dried in vacuo to obtain 12.02 g of hebutane-soluble matter. A portion of the powder was taken as a 0.2% by weight tetralin solution and its intrinsic viscosity was measured at 35°C.

The polymer completely dissolves in hot tetralin and has an intrinsic viscosity of 1
．． 48 (d/g), syndiotactic bendanod fraction 0.87, melt index 1.6 (g/10
), die swell is 1.60 (-), melt strength measured at 220'C is 2.2 (g) (drawing speed 150 (m
/min)).

Example 2 The amount of 1.7-octadiene used was changed to 0.60 g.
The same procedure as in Example 1 was carried out except that 40 g was used to obtain 152 g of powder.

The intrinsic viscosity of the obtained powder was 1.40 (d/g),
The syndiotactic pentad fraction is 0.28, the melt index is 3.0 (g/10 min), the die swell is 1.43 (-), and the melt strength measured at 220°C is 1.8 (g). there were.

Comparative Example 1.7-Example 1 except that octadiene was not used
Follow the same procedure to prepare powder 140gj8 medium soluble content 0.1
I got g. The powder had an intrinsic viscosity of 1.40 (a/g) and a syndiotactic pentad fraction of 0.86.

The melt index is 3.6 (g/10 min), the die swell is 1.09 (-), and the melt strength at 220°C is 0.
It was 78 (g).

Example 3 The same procedure as in Example 1 was carried out except that 3.0 g of 1.7-octadiene was used, and 127 g of powder and 0 solvent-soluble content were prepared.
．． 2g was obtained.

The obtained powder completely dissolves in tetralin at 135°C, exhibits an intrinsic viscosity of 2.68 (a/g), a diotactic penclad fraction of 0.84, and a melt index of 0.08 (a/g). 10 minutes).

A stabilizer was added to the obtained copolymer and the mixture was heated at 230°C and 1120k.
A press sheet was prepared by holding at g/cffl for 3 minutes.

The sheet was transparent, but there was some unevenness in transparency.
It was determined that a gel was beginning to form under these polymerization conditions.

FIG. 1 shows the IR absorption spectrum of a 0.70 mm thick press sheet. FIG. 2 is an IR absorption spectrum of a comparative polymer.

The copolymer obtained by the method of the present invention had vinyl group absorption at 1640 cm-', and it was clearly recognized that 1,7-octadiene was copolymerized.

Next, H-NMR was measured to quantify the vinyl group. Measurements were performed using a 270 MHz spectrometer at 140'C with CbDb as solvent. The method of JP-A-2-64111 was referred to as a method for quantifying the diene incorporated into the polymer. 6. As shown in Figure 3. Absorption based on vinyl protons was observed near oppm, and its amount (
Pendant vinyl group) was calculated to be 0.5 mol%.

According to the theory of high gelation, 50% of the pendant vinyl group
Gelation occurs at the point where the above reacts, and the amount of crosslinked vinyl groups at this point is also 0.5 mol%, so the 1,7-octadiene content of the propylene copolymer is 1.
．． Estimated to be 0 mol%.

Since the amount charged was 3.0 g and the amount of polymer was 127 g, the amount of 1,7-octadiene reacted was almost quantitative.

Reference Example FIGS. 4 and 5 show the frequency dependence of the melt viscosity (η) of the copolymer of Example 1 and the non-diotactic polypropylene homopolymer of Comparative Example.

The homopolymer shows little change in viscosity with frequency and exhibits behavior close to Newtonian viscosity, but the copolymer of Example 1 has a large frequency dependence of viscosity and exhibits significant non-Newtonian behavior.

Figures 6 and 7 show the storage modulus (G゛) of the above sample.
It is plotted against the frequency of . As expected for a polymer with a long chain branched structure, the example sample exhibits large storage modulus values.

[Brief explanation of the drawing]

FIGS. 1 and 2 show IR absorption spectra measured for the polymers of Example 3 and Comparative Example. Figure 3 shows H-N measured for polymer B of Example 3.
An MR spectrum is shown. Figures 4 to 7 show the results of measuring the viscoelasticity of the molten polymer by varying the crystallinity and vibration frequency. [Effects of the Invention] A feature of a polymer having a long chain branched structure is its viscoelastic behavior when melted. That is, when compared to a linear polymer (syndiotactic polypropylene homopolymer) with the same intrinsic viscosity, (]) melotoindenox is smaller (higher melt viscosity), and (2) when extruded from a nozzle. (3) large melt strength; (4) large dependence of melt viscosity on slip rate;
(5) Exhibits characteristics such as a high elastic modulus of the melt. In practical terms, it facilitates melt spinning, blow molding, thermoforming of sheets, etc.

Claims (1)

[Claims] 1) Propylene and at least one type having 6 to 20 carbon atoms
consisting of an alkadiene having vinyl bonds at both ends, 1
,2,4-Trichlorohenzene solution^1^3
In C-NMR, the peak intensity observed at about 20.2 ppm based on tetramethoxysilane is 0.6 or more of the total peak intensity attributed to the methyl group of propylene, and the content of the alkadiene monomer unit is 0. .01~
A crystalline propylene copolymer having an intrinsic viscosity of 0.4 to 10 dl/g as measured in a tetralin solution at 135°C. 2) Propylene and at least one carbon number 6-20
A metallocene compound having an alkadiene having vinyl bonds at both ends represented by the following formula. R″(CpRn)(CpR′m)MeQk (wherein each Cp is a cyclopentadiene or substituted cyclopentadienyl ring; each Rn may be the same or different and is a hydrocarbyl ring having 1 to 20 carbon atoms) each R'm, which may be the same or different, is a hydrocarbyl residue having 1 to 20 carbon atoms, and R'' is a structural bridge between the Cp rings that provides steric rigidity to the catalyst. ; Me is Ti, Zr or Hf; each Q is a hydrocarbyl residue or halogen having 1 to 20 carbon atoms; 0≦k≦3; 0≦n≦4; and 1≦m≦4; ; and R'm is (CpR'm)
is selected such that it is sterically different from (CpRn)) and a cocatalyst.