JPS60195109A - Polypropylene resin composition for high-fluidity injection molding - Google Patents

Abstract

PURPOSE:To provide the titled composition of great industrial value, with high elongation at breaking having melt flow index exceeding a specific value, also of such molecular weight distribution as to be predominant for high-molecular weight region. CONSTITUTION:The objective composition can be obtained by polymerization, using a catalytic system comprising, as Ti-component, a solid catalytic component prepared, for example, by treatment of a Ti-compound with halogenated hydrocarbon, under such a condition that a polypropylene with high-molecular weight region- predominant molecular weight distribution can be formed. The resulting composition has the following characteristics: (1) melt flow index (MFI) >=10; (2) MW/MN >=6. This ratio can be calculated through the following procedures: first, a molecular weight distribution curve is determined by being subjected to gel permeation chromatography (GPC) followed by expressing the resultant data using rectangular coordinates with ordinate and abscissa representing amount of elution and natural logarithm of molecular weight, respectively; second, with its peak as the center, said curve is divided into three regions, i.e., high, medium, and low molecular weight ones, and furthermore, the high-molecular weight region is approximated with Gaussian distribution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies to a city θf having a melt flow index of 10 or more.
For injection molding with high mobility and high elongation at break, ＠
Concerning Lipropylene Resin x++1 composition.

Since polynolopyrene is lagging behind in rigidity and is of low quality, it has been used for many purposes.In order to save capital and energy, polynolopyrene is used for high flow of 4gIJ products and thin walls of molded products. Hi is being measured.

In order to achieve a high fluidity ratio of holiflopyrene resin, the best way is to lower the molecular weight. When propylene is polymerized to obtain j'4-ripropylene, a chain transfer agent such as hydrogen is cooled to lower the molecular weight.
Heat and mix with a lanocal generator such as peracid f arsenic to form a molecule.
- It has been found that high flow rates can be achieved by the full-length method.

However, if the molecule i(t) is simply lowered by the method described above and the r5 IJ propylene resin is subjected to high IIL kinetics, the resulting f resin will have a smaller ripple at breakage, and therefore When actually made into a molded product, its practical strength is poor.

The first objective of the present invention is to provide a polyglopylene resin composition with high fluidity and high elongation at break. The present invention has a melt flow index of 10 or more and is suitable for use in glupermeation chromatography (GPC). And d(
1] Divided into high molecular weight range, low molecular weight range, and intermediate weight range around the peak position of the molecular m distribution curve where the vertical axis is the elution amount and the horizontal axis is the natural logarithm of the molecule J.
The present invention relates to a fluid polypropylene resin composition with high elongation at break, characterized in that MW/MN is 6.0 or more when the t region is approximated by a Gaussian distribution.

In the present invention, t? As a polypropylene resin, it is necessary to use )51J glopylene, which has relatively high stereoregularity, since it has high rigidity, which is an inherent property of id polyglopylene resin. As for the degree of stereoregularity, for example, when the powder state before granulation is extracted with boiling n-hebutane for 10 hours using a Soxhlet extractor, the henotane extraction residue -g (
Polypropylene or glopylene with I
1, a copolymer with hexene-1 is preferred.

If it is 98.0 or more, the impact resistance becomes a problem, which is not preferable.

In the present invention, jtlLF I is a value measured at 230°C according to ASTM D1238 and expressed in units of ji/10m1n, and when MF I is 10LJ or less, the flowability is poor, and the molding cycle during injection molding is shortened and the injection pressure is Energy saving effects such as reduction in energy consumption cannot be realized. Midfielder
A particularly preferred range of I is 15-100.

In the present invention, GPC is measured at 135°C using 1,2,4-trichlorobenzene as a solvent. Measured as a difference. 5 1■W/'4N in the present invention is determined as follows. As shown in Figure 1, the molecular weight distribution curve in which the horizontal axis [111] is expressed as the natural logarithm of the molecular weight and the vertical axis is expressed as the elution amount is divided into three parts.
7 distribution.

For example, the method of approximating the molecular weight distribution with a Gaussian distribution is as follows:
urnal of chromatographic
5science vo120 June 198225
2 is explained in detail. That is, the molecular weight distribution curve is approximated by the following formula.

Y = Ym-exoC(X Km)/'28:]Y;
Height Ym when natural logarithm of molecular weight 1 (tn (molecule 1)) A
ViH is calculated.

In the present invention, the above i+1! It is safe to maintain a large elongation at break if the Mw/"・IN of the polymer j7) region measured and calculated using the I standard method is 6.0 or more. - (i 4
High stereoregularity with elongation at break measured by 'II' of 200% or less, especially II of 90 or more, J? Su7'Dji°reno? , 110096 or less, which is preferable. , 1. The Mw/MN of the j-molecule r-mouth area has a large effect on the elongation at break. 4) A-element is shown in FIG. 2. Figure 2 shows M1y/
When the MN is 6, the elongation at break is large, and the method for producing the composition of the present invention is not particularly limited as long as the polypropylene obtained satisfies the above conditions. Measure the molecular weight distribution of polynolopyrene obtained by combining at a constant temperature with the hydrogen concentration in the gas phase constant, divide the molecular weight curve into three parts using the method described above, and find the molecular weight at the boundary point on the high molecular weight side. , polymerization conditions are set to obtain j9 IJ propylene having a molecular weight such that the molecular weight distribution curve has a peak in a molecular weight range larger than that molecular weight. Usually, it is sufficient to set the conditions of the hydrogen concentration in the gas phase and the combination temperature. The composition of the present invention can be produced under the two conditions of hydrogen concentration and polymerization temperature determined in this way (with the addition of a condition for adding high molecular weight polypropylene if necessary) (for example, by changing the hydrogen degree in the same polymerization system). However, it is obtained by performing two-stage polymerization.As a guideline, the proportion of the higher molecular weight Jjt to the total composition of J?IJ globylene is 30 wt% or less, usually 30 wt% to 5 wt%.
%.

Using a catalyst system that gives a polymer with a large distribution. Although many excellent catalyst systems are already known, it is not known what kind of molecular weight distribution the polynolopyrene produced in each catalyst system has.
Although it is not possible to clarify all catalyst systems, as a catalyst system that gives a relatively wide molecular J and distribution in a high molecular region, a solid catalyst component obtained by treating a titanium compound with a halide, especially a halogenated hydrocarbon, is used as the titanium component. Alternatively, during polymerization, oxygen-containing compounds, especially organic acid esters,
When a ketone ratio compound is used, although the reason is not clear, there is a tendency to obtain a polymer with a wide molecular weight distribution in the high molecular weight range. In particular, as a catalyst thread that provides a polymer with a wide range of high molecular weights) - Rodan ratio Magnesium treated with halodan ratio carbon f arsenide, oxygen-containing compound Active titanium catalyst obtained by supporting halodan f titanium on a carrier and organoaluminum ratio Examples include catalyst systems consisting of compounds and organic acid esters. When using a catalyst system that produces a polymer with a relatively wide molecular weight distribution in a relatively high molecular weight region as described above, the polymerization is carried out under certain polymerization conditions, such as keeping the hydrogen concentration in the gas phase and the polymerization temperature constant. The composition of the present invention can be obtained even if the method is carried out.

The composition of the present invention has excellent properties as a polypropylene for injection molding, in that it has excellent fluidity during molding and the elongation of the resulting molded product at break is large, and is valuable for manufacturing. be.

The present invention will be further explained with reference to Examples below.

In Examples and Comparative Examples, physical properties are measured by the following method.

MFI (,!i'/10m1n) ASTM D1
238 Tensile Yield Strength (LV Wound 2) ASTM D6
38-64T elongation at break (ch) ASTM D63
8-64T bending rigidity (k1Mo+2) ASTM
D747-631 Izod impact strength (with notch) A
STM D256-56MFI is 230℃, other physical properties are 8 cm x 16 tyn x by injection molding machine
2 mm injection molded sheets were produced and measured at 23°C.

Example 1) Production of active titanium catalyst 1) Magnesium chloride 20g, orthoethyl acetate 1In
l, 1,2-dichloroethane 4d co-pulverized with 4
Activated titanium catalyst (A) obtained by contact treatment with salt rhititanium and subsequent washing with n-hemethane, which was repeated three times.

11) A commercially available highly active triad [Hititanium catalyst TBN-05 (dt number) manufactured by Marubeni Solve A Co., Ltd. was used for the first time. Active titanium catalyst (+3).

2) Polymerization conditions for production of polybabile/1) Using a catalyst consisting of 2 g of the above activated titanium catalyst (A), ) IJ ethyl aluminum 5 rnl, diethylaluminum chloride s, 5 rrrl * rotolyl fermentation methyl 4 htl, propylene itself was used as a medium. In the bulk polymerization method, polymerization was carried out at 75° C. using a 1 m polymerizer with a constant hydrogen concentration, and then the catalyst was deactivated with isonoro-2-nol and washed three times with propylene at 40° C. to obtain polynolopylene. Approximately 200,009/jj-cat per active titanium catalyst.

Using a catalyst consisting of ethylaluminum chloride 800, d and using n-hegetane as a medium, the total pressure was 10 kg/c.
rn-darts, polymerized at 70°C. At this time, polymerization was carried out using a two-stage polymerization method in which the hydrogen concentration was kept constant or the hydrogen concentration was changed and carried out in two stages and one beak, and after 2 hours of polymerization, the catalyst was washed repeatedly with drained water in which the catalyst had been deactivated with methanol. After that, the n-hegetane layer was coated with P to obtain polypropylene.

After drying the powder obtained in 1) and 11) above, a phenolic antioxidant (to powder 2/1000 weight ratio) was added.

Calcium stearate (weight ratio of 1/1000 to the powder) was added to granulate the mixture, and then injection molded 7-plates were prepared and their physical properties were measured.

The results are shown in the table. Example 2 was carried out in the same manner as Example fa111 except that the hydrogen concentration was changed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a molecular weight distribution curve and its division method, in which a shows a high molecular weight range, b shows an intermediate weight range, and C shows a high molecular weight range. FIG. 2 is a graph showing the relationship between JAW/MN (!: elongation at break) in the high molecular weight range, and the broken line indicates Mw/MN=6.0.

Claims (1)

[Claims] 1) Melt flow index (MFI) is 10 or more.
Measured by cell permeation chromatography (Gl)C), r:, ++'i is the elution amount,
UJj (iGI + peak position of the molecular weight distribution curve expressed by the natural logarithm of all molecules (molecular weight range centered on Feng, 1
A highly fluid polyglopylene tree with a large elongation at break, characterized by a MwA4N of 6.0 or more when approximated by the I-us distribution for the entire Y-row area and the middle JJt area. i7+tifl composition.