DE2127709A1 - Polypropylene mouldings - non-tacky but with soluble polymerization components remaining - Google Patents

Abstract

The moulding material contains fine silica gel with a max. particle size of 0.005 - 0.05 mu. The quantity of silica is 4 - 80%, pref. 8 - 40% of the wt. of the polymerisation components which are soluble in boiling n-heptane and which are allowed to remain in the material.

Description

Badische Anilin- & Soda-Fabrik AG 2127709

Our reference: O.Z. 27 5 ^ 8 .HWz / Wil

67OO Ludwigshafen, 3.6.197I Polypropylene porcelain masses

The present invention relates to polypropylene molding compositions

(1) a polypropylene, in which all of the polymerization formed in - under normal conditions - boiling n-heptane - at a weight ratio of polypropylene; n-heptane of 5:95 - has left soluble fractions, and that together ■ is set from (1.1) 50 to 98 percent by weight of a fraction insoluble in n-heptane - under the conditions mentioned and (1.2) 50 to 2 percent by weight of one - among those mentioned Conditions - fraction soluble in n-heptane and

(2) finely divided silica gel.

The known molding compounds of this type contain a silica gel, the smallest particle diameter of which is around 1 micron, they are hardly used in technology. In the case of the finely divided silica gel-containing polypropylene molding compounds that are mostly used in technology the smallest particle diameter of the silica gel is also around 1 micron, which is polypropylene however, one whose components which are formed during the polymerization and which are soluble in n-heptane - under the conditions mentioned - are one has removed. One reason for this situation is that molded parts made of the first-mentioned molding compounds on the surface are sticky, especially at elevated temperatures. If this disadvantageous property could be eliminated, the first and second mentioned molding compounds mutually beneficial Complementary in terms of application technology, as they differ from one another, desired for one or the other application purpose have physical properties.

Accordingly, the present invention was based on the object To show polypropylene molding compositions of the type defined at the outset that result in molded parts whose surface does not or is sticky to a much lesser extent.

It has been found that this object can be achieved if

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an extremely finely divided silica gel is used in the molding compounds, namely in a certain amount based on the polypropylene content soluble in n-heptane.

The present invention thus relates to polypropylene molding compositions from (1) a polypropylene, in which all of the polymerization resulting from - under normal conditions boiling n-heptane - with a weight ratio of polypropylene: n-heptane of 5:95 - has left soluble components, and that is composed of (1.1) 50 to 98, in particular 70 to 95, Percentage by weight of a fraction insoluble in fe n-heptane - under the conditions mentioned - and (1.2) 50 to 2, in particular JO to 5> percent by weight of one - under the stated conditions - Part soluble in n-heptane and (2) finely divided silica gel. The molding compositions according to the invention are characterized in that that they are per 100 parts by weight of the polypropylene portion under (1.2) 4 to 80, preferably 8 to 40 parts by weight of a finely divided Contain silica gels, the largest particle diameter of which is in the range of 0.005 to 0.05 microns.

The following applies to the components of the molding compositions according to the invention To say the following:

(1) The polypropylene component is known as such and is commercially available; it can also be easily made,

z. B. according to the - especially summarized - teachings from Austrian patents 202 346, 204 and 220 806.

(2) The silica gel component is also known per se and is available on the market; she is z. B. obtainable by gas phase conversion at high temperature of silicon tetrachloride with water vapor.

The molding compositions according to the invention can be produced by the relevant customary methods using the relevant customary devices (e.g. mixer-extruders, mixer-kneaders) by intimately mixing the components together at an elevated temperature (expediently 200 to 550 ^° C.). You can -

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if desired - the molding compounds also incorporate other relevant customary additives, e.g. B. coloring substances or stabilizers.

The molding compositions according to the invention are particularly suitable for producing films, but also other molded parts, such as Injection molded articles, pressed parts and hollow bodies (bottles).

example 1

It is assumed

(1) 100 parts by weight of a polypropylene in which all formed during the polymerization in - under normal conditions - boiling n-heptane - at a weight ratio Polypropylene: n-heptane from 5 J 95 - has left soluble components, and that is composed of

(1.1) 75 percent by weight of a portion which is insoluble in n-heptane under the conditions mentioned, as well as

(1.2) 25 percent by weight of one - under the conditions mentioned - soluble in n-heptane and

(2) 10 parts by weight of a finely divided silica gel, the largest particle diameter of which is 0.05 microns.

(For 100 parts by weight of the polypropylene content under (1.2) i.e. 40 parts by weight of the silica gel.)

The components (I) and (2) are mixed together in a kneader irinig (200 ⁰ C, 5 minutes).

Pressed plates are produced with the dimensions 100 mm 100 χ χ 2 of the present invention thus obtained molding composition at 200 ⁰ C, whereupon the plates are stored in a drying cabinet for 48 hours at 100 ⁰ C. It turns out that the surface of the plates is not or becomes not sticky.

Comparative experiment

The procedure is exactly as in Example 1 with the only exception that a silica gel is used, its smallest Particle diameter is about 1 micron. Here the

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The surface of the press plate is sticky.

Example 2

It is assumed

(1) 100 parts by weight of a polypropylene: in which all formed during the polymerization in - under normal conditions - boiling n-heptane - at a weight ratio Polypropylene: n-heptane of 5:95 - has left soluble components, and that is composed of

(1.1) 65 percent by weight of one - under the conditions mentioned - Part insoluble in n-heptane as well

(1.2) 35 percent by weight of one - under the conditions mentioned - Part soluble in n-heptane and

(2) 10 parts by weight of a finely divided silica gel, its largest particle diameter is 0.02 microns.

(For 100 parts by weight of the polypropylene content under (1.2) i.e. 28.6 parts by weight of the silica gel.)

Components (1) and (2) are intimately mixed with one another in a kneader (200 ^° C., 5 minutes).

From the molding composition according to the invention obtained in this way, press plates with dimensions of 100 × 100 × 2 mm are produced ^{at 20O 0} C, whereupon the boards are stored ^{in a drying cabinet at 100 0 C for 48 hours.} It turns out that the surface of the plates is not or becomes not sticky.

Comparative experiment

The procedure is exactly as in Example 2, with the only exception that a silica gel is used, its smallest Particle diameter is about 1 micron. This makes the surface of the press plate sticky.

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Example 3

It is assumed

(1) 100 parts by weight of a polypropylene, in which all formed during the polymerization, in - under normal conditions - boiling n-heptane - with a weight ratio of polypropylene: n-heptane of 5:95 - leave the soluble components has, and that is composed of

(1.1) 90 percent by weight of one - under the conditions mentioned - Part insoluble in n-heptane as well

(1.2) 10 percent by weight of a component soluble in n-heptane - under the conditions mentioned - and

(2) 3 parts by weight of a finely divided silica gel, its largest particle diameter is 0.02 microns.

(For 100 parts by weight of the polypropylene content under (1.2) i.e. 30 parts by weight of the silica gel.)

Components (1) and (2) are intimately mixed with one another in a kneader (200 ^° C., 5 minutes).

Pressed plates are produced with the dimensions 100 mm 100 χ χ 2 of the present invention thus obtained molding composition at 200 ⁰ C, whereupon the plates are stored in a drying cabinet for 48 hours at 100 ⁰ C. It turns out that the surface of the plates is not or becomes not sticky.

Comparative experiment

The procedure is exactly as in Example 3 with the only one Exception that a silica gel is used, the smallest particle diameter of which is around 1 micron. Here the The surface of the press plate is sticky.

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Claims (1)

- β - O.Z. 27 538 Claim Polypropylene molding masses made from (1) a polypropylene in which all of the fractions formed during the polymerization and which are soluble in - under normal conditions - boiling n-heptane - at a weight ratio of polypropylene: n-heptane of 5:95 - have been left, and that is composed is composed of (1.1) 50 to 98 percent by weight of a fraction that is insoluble in n-heptane under the conditions mentioned and (1.2) 50 to 2 percent by weight of a fraction that is soluble in n-heptane under the conditions mentioned, and (2) finely divided silica gel, characterized in that, per 100 parts by weight of the polypropylene fraction, they contain under (1.2) 4 to 80 parts by weight of a finely divided silica gel, the largest particle diameter of which is in the range from 0.005 to 0.05 microns. Badische Anilin- & Soda-Pabrik AG 209851/0963