JPS61155404A - Crystalline polypropylene - Google Patents

Abstract

PURPOSE:A crystalline polypropylene excellent in moldability and the rigidity and transparency of a molding, having an intrinsic viscosity, a weight-average MW/number-average MW ratio and an isotactic pentad fraction which have values in specified ranges. CONSTITUTION:The desired crystalline polypropylene has an intrinsic viscosity [eta]of 0.1-6.0dl/g, a weight-average MW/number-average MW ratio of 2-8 and an isotactic pentad fraction [I] satisfying the relationship.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to crystalline polypropylene, and more particularly to the rigidity of a molded article when it is processed into a molded article.

This invention relates to crystalline polypropylene with excellent transparency and moldability during molding.

[Technical background of the invention and its problems]

Polypropylene is generally heat resistant and chemical resistant.

Polypropylene has good rigidity, moldability, etc., and is widely used as a material for film molding, sheet molding, blow molding, injection molding, etc. However, depending on the application, polypropylene does not fully satisfy the above performance. Do not mean.

Among the above-mentioned performances, in particular, if the rigidity is further improved, it becomes possible to make the molded product thinner, which not only contributes to resource saving and is effective, but also improves productivity.Therefore, conventionally, polypropylene Attempts are being made to develop highly knotty polypropylene to increase the rigidity of (
JP-A-55-81125, 1% JP-A-59-22913). However, the polypropylene disclosed in JP-A-55-81125 has insufficient rigidity, and the polypropylene disclosed in JP-A-59-22313 has somewhat improved rigidity, but still inadequate and insufficiently transparent.

゛- [Object of the Invention] The present invention aims to solve the above-mentioned problems and provide a crystalline polypropylene having excellent rigidity and transparency.

[Summary of the invention]

The present inventors have conducted extensive research to achieve the above objectives.
As a result of the analysis, if the crystalline polypropylene has an intrinsic viscosity, a ratio of weight average molecular weight/number average molecular weight, and a value of the pentad fraction that satisfies the ranges described below, when the crystalline polypropylene is made into a molded article, The present invention was completed based on the discovery that molded products have excellent rigidity and transparency.

That is, the crystalline polypropylene of the present invention has an intrinsic viscosity [η] of 01 to 5. Q dl/9, the ratio of weight average molecular weight/number average molecular weight is 2 to 8, and the isotactic pentad fraction CI) is expressed by the following formula: [I]≧−1,02[η]+98.5 It is characterized by being satisfying.

In the present invention, if the intrinsic viscosity of the crystalline polypropylene is outside the above range and is less than 0.1 dQ79, the impact resistance will decrease; Q dll/9
If it exceeds this value, moldability will decrease.

The preferable range of the value of the above-mentioned intrinsic viscosity is 1.0 to 3,5
It is dQ/9.

Furthermore, if the weight average molecular weight/number average molecular weight ratio is less than 2, the rigidity will decrease and the fluidity during molding will also deteriorate, and if it exceeds 8, the transparency will decrease.

The preferred range of the ratio of weight average molecular weight/number average molecular weight is 3 to 6.

If the isotactic pentad fraction [I] does not satisfy the following formula (% formula %), that is, the intrinsic viscosity is Q, l d
When Q/9, the isotactic pentad fraction is 98
．． If the intrinsic viscosity is less than 398, the intrinsic viscosity is 5. When QdQ/9, if the isotactic pentad fraction is less than 9Z38, the rigidity will decrease. The isotactic pentad fraction [I] is calculated by the following formula: [■]≧-0,12(η)+98.9
It is preferable to satisfy 〇Here, the isotactic pentad fraction is A.

Macramulecule by Zambelli et al.
s, 6.925 (1973),
In other words, it is the isotactic fraction of pentad units in the polypropylene molecular chain measured by a method using C-NMR.In other words, the isotactic pentad fraction is the proportion of 5 consecutive propylene monomer units. This is the fraction of one unit of propylene monomer at the center of the men-bonded chain.However, regarding peak assignment, Macr
Anolecules, 8, 687 (1975). Specifically, the isotactic pentad unit is measured as the intensity fraction of the mmmm peak among the total absorption peaks in the methyl carbon region of the 13C-NMR spectrum.

The value of the isotactic pentad fraction in the present invention is the value of the obtained crystalline polymer as it is, and is not the value of the polymer after extraction, fractionation, etc.

Crystalline polypropylene having the above values is, for example,
It can be manufactured as follows.

That is, after carrying out prepolymerization at °C using a stereoregular catalyst described later and a monomer described later, crystalline polypropylene is produced by main polymerization.

The stereoregular catalyst used here is ethylene.

It is a catalyst commonly used for stereoregular polymerization reactions of propylene and the like, and usually a mixture consisting of a transition metal halide component and an organoaluminum compound component is used.

As the transition metal halide compound, a titanium halide is preferred, and titanium trichloride is particularly preferred. Titanium trichloride is obtained by reducing titanium tetrachloride by various methods; it can be further processed by ball milling and/or solvent washing (for example, washing with an inert solvent and/or an inert solvent containing a polar compound). activated;
Titanium trichloride or titanium trichloride eutectic (for example 'p
Examples include co-pulverization treatment with icQ3 sulfur, halogen derivatives, organic or inorganic nitrogen or phosphorus compounds, etc. Furthermore, a material in which a titanium chloride is supported on a magnesium compound can also be used.

As an organoaluminum compound, the following formula: A
Represents a value of n≦3. ) are preferred.

Examples of such materials include triethylaluminum, triisobutylaluminum, tri-17-n-
Propyl aluminum, diethylaluminium monochloride, diethylaluminium monobromide, diethylaluminium monoiodide, diethylaluminium monoethoxide, diisobutylaluminum monoisobutoxide, diethylaluminum monohydride, diisobutylaluminum monohydride, ethylaluminum sesquichloride etc., and one or more of these can be used.

The molar ratio of AQ/Ti in the mixture of these catalysts is set between 0.1 and 1000.

In addition, as a catalyst component, for example, alcohol.

aldehydes, ethers, esters, lactones, ketones,
Amine, amide, organic phosphorus compound, organic silicon compound,
The use of electron-donating compounds such as thiols, thioethers, and thioesters is unsuitable because the catalyst activity decreases.

Suitable monomers used in the prepolymerization include 4-methylpentene-1,3-methylpentene-1,3-methylbutene-1, ethylene, styrenes (styrene, substituted with an alkyl group having 1 to 10 carbon atoms) Examples of unsuitable heptamers include propylene, hexene, octene, decene, etc.

The polymerization amount of the monomer is 0.02 to 109/unit titanium component, preferably 0.05 to 3.09/unit titanium component.

When the polymerization amount is less than 0.02979-titanium component, the stereoregularity and rigidity are not improved, and when it exceeds 109/9-titanium component, the activity is decreased and the rigidity is not improved.

Further, as the solvent, aliphatic, alicyclic, or aromatic inert hydrocarbons are preferable, and examples thereof include pentane, hexane, heptane, cyclohexane, benzene, and toluene.

The conditions for prepolymerization performed using the above catalyst, monomer, and solvent are as follows.

The monomer concentration is 0.5-500 d/g-solvent, preferably 5-200 WLt/Q-solvent. Temperature is 0-100
C is preferably 10 to 90C. Pressure is 0.01~3
0ky/cm” preferably 0.05 to 15 kl/an
” is.

Main polymerization is carried out after prepolymerization using the above-mentioned monomers.The main polymerization conditions include a temperature of 0 to 100C, preferably 30 to 90C.
0 C, and the pressure is 0.01 to 45 ky/an, preferably 0.05 to 40 ky/cm". Known methods can be applied for the prepolymerization and the first polymerization. For example, slurry Examples include polymerization, solution polymerization, gas phase polymerization, and liquid phase polymerization using an olefin monomer as a medium.

Intrinsic viscosity 1 Ratio of weight average molecular weight/number average molecular weight (MY/Mn) of crystalline polypropylene.

The value of the isotactic pentad fraction is controlled, for example, in the above manufacturing method as follows.

The intrinsic viscosity is determined by adjusting and selecting the amount of molecular weight regulator such as H2 used in the main polymerization, MW/Mn and isotactic pentad fraction by adjusting and selecting the catalyst in the prepolymerization, the type of monomer used in the prepolymerization, etc. The value is controlled.

When the surface of the crystalline polypropylene powder produced by the above method and controlled to the above value is observed under a scanning electron microscope, the surface is cracked in a network pattern, unlike conventional polypropylene powder.

7, it is presumed that the cleaning effect in the washing step after main polymerization is significantly enhanced and the isotactic yield (IY) is lowered.

Here, in the case of the present invention, the isotactic yield refers to the residual fraction of the entire polymer obtained by reprecipitating the slurry with methanol after extraction with boiling 1i1n-heptane.

In conventional polypropylene, isotactic yield and rigidity were in a directly proportional relationship, but in the polypropylene of the present invention, a relationship was obtained in which the lower the isotactic yield, the higher the rigidity.

When producing a molded article using the crystalline polypropylene powder obtained by K as described above, appropriate amounts of heat stabilizers, antioxidants, and ultraviolet absorbers are added as necessary.

Anti-blocking agents, lubricants, nucleating agents, coloring agents and other additives can be blended. In addition, ethylene propylene rubber is used for purposes such as improving impact resistance.

Polyethylene and ethylene-propylene copolymers can also be blended.

In addition, in the present invention, any crystalline polypropylene whose values such as the above-described intrinsic viscosity are set to predetermined values may be used, and the manufacturing method thereof is not necessarily limited to the above-described method.

[Examples of the invention] Examples 1 to 10. Comparative Examples 1 to 5 1g) 2Q of dehydrated and purified n-hebutane was charged into a stainless steel polymerization reactor having a prepolymerization internal volume of 5Q. In addition, titanium trimide 0
49. diethylaluminum chloride)” 5 mJ!
! (AQ/Ti = 15.4 mol 1 mol) was added and mixed, and the leaves calculated to have the indicated polymerization amount of dehydrated and purified monomers were added, and the mixture was heated to a temperature of 20 to 6 mol.
Prepolymerization was carried out under the conditions of 0C1 pressure of 0.2 to 1.2 kl/cm2G and stirring for 30 to 90 minutes.

(b1 polymerization After the prepolymerization, the reactor temperature was subsequently increased to 65C.

After sufficiently replacing the ff phase with propylene and supplying a measured amount of water to achieve a predetermined intrinsic viscosity, propylene was continuously added while stirring so that the total pressure remained constant at 9.0 kg/cm2G. The main polymerization was carried out for 60 minutes at a temperature of 65C.

Thereafter, 30 ml of n-butanol f was added to stop the polymerization and catalytic decomposition was performed. After removing unreacted propylene, the produced polypropylene was separated, washed with n-hebutane, and dried to obtain a powdery polymer.

The isotactic pentad fraction and isotactic yield (IY) of the polymer were measured and observed according to the specifications described above, and the intrinsic viscosity [η), Mw/Mn, and powder form were measured and observed according to the specifications below. A molded article was manufactured using the molded article, and the tensile modulus (rigidity) and film haze were measured according to the following specifications, and these are summarized in the table.

Intrinsic viscosity: 13511:', measured value in tetralin.

Mw/Mn: Measured by 't' rubraniation chromatography (GPC method).

To 100 parts by weight of orundichlorobenzene solvent, 0.089 parts of polymer (3,5 parts as stabilizer)
- 0.059 di-t-butylhydroxytoluene added to 100 parts by weight of polymer) was added to form a solution, and then 2
Impurities such as dust were removed using a ~5μ filter, and measurements were made at a column temperature of 135C, a flow rate of l, and Qrnt/min. Quantitative ratios were calculated on a polystyrene basis.

Observe the surface with a scanning electron microscope in powder form.

Tensile modulus: Based on JISK6758.

Film haze: Compliant with JIS K7105.

Comparative Example 6 Titanium trichloride 0.49% was used as a catalyst. Polymerization and measurement were carried out in the same manner as in Example except that diethylaluminum chloride 51 and ethyl benzoate (electron donating compounds) o and 1y were used.

[Effects of the Invention] As is clear from the embodiments of the invention, K, intrinsic viscosity #
When comparing two identical products, the crystalline polypropylene of the present invention has a tensile modulus (stiffness).

It has excellent haze (transparency), as well as moldability and impact resistance.

Therefore, if the crystalline polypropylene of the present invention is used, it becomes possible to improve the rigidity of the molded article and to make the molded article thinner, which is effective in terms of resource saving and productivity.

The crystalline polypropylene of the present invention is useful not only as a material for films but also as a material for home appliances, industrial materials, and general miscellaneous goods. 〇Procedural amendment January 25, 1985 Mr. Manabu Shiga, Commissioner of the Patent Office■, # Display of patent application No. 274479 filed in 1982 2, name of the invention Crystalline polypropylene 3, relationship with the case of the person making the amendment Name of patent applicant Idemitsu Petrochemical Co., Ltd. 4, agent 5, date of amendment order 6 , Subject of amendment Column for detailed explanation of the invention in the specification It
B? The column for detailed description of the invention in Section 4 is amended as follows.

(1) r 59-223 described on page 2, line 15 of the specification
13 Publication" is amended to "r5L22913 Publication".

(2) “[11≧-0” in the first line of page 45 of the specification pi
, 12[η] + 98.9J as r [11≧-1,
Corrected to 02[η] +88.91.

(3) "I'1973" stated in page 4 of page 55 of the specification is amended to r 1973J.

(4) 1975 as stated on page 13, line 11 of the specification.”
is corrected to r 1975J.

(5) "Relationship of direct proportion" stated on page 11, line 3 of the specification
(6) Correct "gel permeation" described on page 13, line 11 of the specification to "gel permeation."

Claims (1)

[Scope of Claims] The intrinsic viscosity [η] is 0.1 to 6.0 dl/g, the ratio of weight average molecular weight/number average molecular weight is 2 to 8, and the isotactic pentad fraction [I] is A crystalline polypropylene satisfying the following formula: [I]≧-1.02[η]+98.5.