DE2033803B2 - Polypropylene molding compounds - Google Patents

Description

The present invention relates to polypropylene wise ranging from 1.2 to 3.8.

Molding compounds made of polypropylene and 5 to 80 weight (under the expression "approximately the same" is im

percent (based on the total weight of the form 40 present context always understood that

mass) plate-shaped talc particles, with none of the corresponding characteristics more than r5 ^{o /} _u

these particles have a thickness of 0.01 to 1 μ and one of the mean value of the two characteristics concerned

have mean largest diameter of 2 to 50 μ. deviates.)

The known molding compositions of this type contain as The molding compositions according to the invention allow

The usual polypropylene, especially those made from it in 45 molded parts, which, in addition to other valuable

Commercially available types. These types are poly- full properties with little or no properties

propylene, of which (have brittleness at a weight ratio. The molding compounds are suitable

Polypropylene: toluene of 5:95) in (below normal - therefore also for the production of mechanically stressed

conditions) boiling toluene less than 10 parts by weight, such as household items or technical

weight percent soluble and more than 90 weight percent 50 parts. With a filler content of not more than

are insoluble, in each case both the intrinsic 50 weight percent are the molding materials because of their

Viscosity as well as the molecular weight distribution good toughness and stretchability continue z. B.

the soluble and the insoluble part strongly from - to the extrusion of monofilaments, tapes, sheets, foils

are different from each other; and hollow bodies are particularly suitable in each case.

The intrinsic viscosity of the soluble fraction is considerably lower in the case of the molding compositions according to the invention than that of the insoluble part. The polypropylene to be added from such can be produced in a simple manner Moldings made from molding compositions can be obtained if one of two well-known ones compared to other comparable molded parts is based on facts: (1) Both conventional polymerisation have a number of advantageous properties, but have propylene according to Ziegler-Natta - for example in toluene - the disadvantage that they are brittle and therefore mechanically 60 a polypropylene is formed, which is made from one in each boiling point cannot be heavily used. the toluene is soluble and insoluble, The object of the present invention was to determine the intrinsic viscosity of the soluble fraction reasons, polypropylene molding compounds which initially defl- is considerably less than the insoluble parts, ned type that allow molded parts (2) In this conventional polymerization can be through to obtain therefrom the variation of the process conditions suitable with the above-mentioned 65 (distribution not burdened or to a significantly lesser extent use of molecular weight regulators, changes are. at temperature and pressure, modifications of the It has been found that this object is achieved catalyst system) produce a polypropylene that

overall (that is, both in its.! soluble and """. in its insoluble part) has either a relatively high or a relatively low intrinsic viscosity. - In practice you can accordingly in jwei separate approaches a polypropylene A with a - overall - relatively high intrinsic viscosity and a polypropylene B with a - in ^r total - relatively low intrinsic viscosity, such that the toluene is soluble in boiling toluene The proportion of polypropylene A has (approximately) the same intrinsic viscosity as the proportion of polypropylene B which is insoluble in boiling toluene (if the polypropylenes A and B have also been produced under process conditions that are as close as possible to each other, then their molecular weights are in general also Distributions equal or approximately equal). The polypropylene to be used in the molding compositions according to the invention is then obtained by mixing - for example in a kneader or extruder - the two last-mentioned product components in the required proportions. It goes without saying, however, that the molding compositions according to the invention do not depend on the manner in which the associated polypropylene has been produced. but only on the specification that this polypropylene must have.

The molding compositions according to the invention can be produced as such in the relevant conventional manner by homogenizing their components with one another, e.g. B. initially kneaders, mixers or roller mills. The working temperatures here should be 180 to 400, preferably 180; Is 250 ⁰ C.

The further processing of the molding compositions to form molded parts can also be carried out in the relevant customary manner take place, in particular by extrusion and injection molding. Suitable working temperatures are here 180 to 300, preferably 200 to 260 ° C.

The molding compositions demonstrated in the following examples were obtained as follows:

It is assumed

(A) a customary fine-powdered polypropylene, which consists of a portion which is soluble and insoluble in boiling toluene. The intrinsic viscosities (measured in decalin at 130 ⁰ O are: insoluble part: 3.6, soluble part: 2.6; (B) a customary other finely powdered polypropylene, which consists of a part which is soluble and insoluble in boiling toluene The Iutrinsic viscosities (measured in decalin at 13O ⁰ C) are: 2,7-insoluble content, soluble fraction 1.6.

The soluble portion of the polypropylene under (A) and the insoluble portion of the polypropylene under (B) are isolated by extraction with boiling toluene, whereupon these two portions - their molecular weight distribution (determined by the method of gel permeation chromatography) are approximately the same - in a weight ratio of 25:75 with one another and at the same time with the talc particles (the amounts of which can be found in the examples) (kneader; working temperature. 200 ^° C.).

example 1

The molding compound consists of the polypropylene described above and 20 percent by weight (based on the total weight of the molding compound) platelet-shaped talc particles, the latter having a thickness in the range from 0.02 to 0.8 µm and a mean largest diameter from 20 to 30 µm.

For comparison, an analogous molding compound is produced which differs from the molding compound according to the invention only in the type of polypropylene used. This comparative polypropylene hr.t - total - an intrinsic viscosity (measured in decalin at 130 ⁰ C) of 2.6 and (at a weight ratio of polypropylene: toluene 5: 95) in (under normal conditions) boiling toluene to 7 Weight percent soluble, 93 weight percent insoluble.

The property values given in the table are determined on both molding compounds. Included clearly shows the superiority of the molding composition according to the invention.

properties unit Test method According to the invention
Molding compound Comparative
Molding compound Impact strength (23 ° C)
Notched impact strength (23 ⁰ C)
Elongation at break cm x kp / cm ³
cm x kp / cm ²
O,
O DIN 53 453
DIN 53 453
DIN 53 455 without break
8th
400 40
4th
15th

Example 2

The molding compound consists of the polypropylene described above and 30 percent by weight (based on the total weight of the molding compound) platelet-shaped talc particles, the latter having a thickness in the range from 0.02 to 0.8 μ and a mean largest diameter of 20 to 30 μ to have.

For comparison, an analogous molding compound is produced which differs from the molding compound according to the invention only in the type of polypropylene used . This comparative polypropylene has - overall - an intrinsic viscosity (measured in decalin at 130 ^° C.) of 2.6 and is 7% by weight soluble (at a weight ratio of polypropylene: toluene of 5:95) in boiling toluene (under normal conditions) , 93 percent by weight insoluble.

The property values given in the table are determined on both molding compounds. This clearly shows the superiority of the molding composition according to the invention.

properties unit Test method According to the invention
Molding compound Comparative
Molding compound Impact strength (23 ° C)
Notched impact strength (23 ⁰ C)
Elongation at break cm x kp / cm ²
cm x kp / cm ²
/ 0 DIN 53 453
DIN 53 453
DIN 53 455 without break
7th
100 22nd
3.5
8th

Example 3

The molding compound consists of that described above Polypropylene and 40 percent by weight (based on the total weight of the molding compound) plSttohenf örmigen S Talc particles, the latter having a thickness in the range from 0.02 to 0.8 u, and a mean largest diameter have from 20 to 30 μ.

For comparison, an analogous molding compound is produced which differs from the molding compound according to the invention only in the type of polypropylene used. This Vergleicbs-Poiypropylen bat - as a whole - a Jntrinsic viscosity (measured in m Dekalia lW'Q of 2.6 and is (for a Gewichteverhaltnis polypropylene: soluble toluene of 5:95) in (under normal conditions) boiling toluene to 7 percent by weight, at 93 percent by weight

insoluble. ,

The in the table specified property values determined. This clearly shows the superiority of the invention Molding compound.

properties unit PrOfmetbode According to the invention
Molding compound Comparative
Molding compound Impact strength (23 ° Q
Notched impact strength (23 ° Q
Elongation at break cm x kp / cm ^a
cm x kp / cm ⁸
O/
/O DIN 53 453
DIN 53 453
DIN 53 455 40
5
60 10
2.5
2

Claims (1)

can be if the molding compounds are considered polypropylene Claim: contain a certain mixture of two of one other different polypropylenes ^ which are in their Polypropylene molding compositions made of polypropylene and solubility differ greatly from one another, but in 5 to 80 percent by weight (based on the total δ of their intrinsic viscosity and their molecular weight of the molding compositions) they have platelet-shaped trough weight distribution.
Cumulative particles, these particles having a thickness of 0.1 to 1 μm and a mean largest diameter corresponding to polypropylene molding compounds made from poly-knife of 2 to 50 μm, thus propylene with 5 to 80, preferably 10 to 50 Characterized that the molding compounds as weight percent (based on the total weight of the polypropylene contain a mixture of molding compounds) platelet-shaped Tafcum particles, where- , _x -_ .. _place ". . .,. _, with these particles having a thickness of 0.01 to 1, preferably (a) 70 to 80 parts by weight of a polypropylene, "^ e from 0 02 to 0 8 μ and a mean largest of the (with a weight ratio poly ^^ ser from 2 to 50, preferably from 5 to 30 μ propylene: toluene from 5:95) less than 1 Ge J ££ "JJ ^ Zdm ^^ nlor ^^ n stad da ^ Weight percent m (under normal conditions) _fa “^^ ΐ ^ _{that s} i _e as polypropylene boiling ι oluene is soluble, and p,. *? do _a it ".n anc (b) 20 to 30 parts by weight of a polypropylene, mixture develop and form of which (with a weight ratio of poly- (a) 70 to 80 parts by weight of a polypropylene, of propylene: toluene of 5:95) more than 99% (with a weight ratio of poly weight percent in (under normal conditions) ²⁰ pylene: toluene of 5: 95) less than 1 weight boiling toluene are soluble, percent in (under normal conditions) boiling • jwn ,. ,. j η j toluene is soluble, and with the provisos (i) the sum of the overall ^) OQ to 30 parts by weight of a polypropylene of weight parts (a) and (b) are respectively 100, ^ _{em (Bej ejnem} weight ratio Polypro-QI) that the polypropylenes under (a) and (b) 25 _py i _en each. Toluene of 5:95) more than 99 weight both the approximately the same intrinsic viscosity _percent in boiling (under normal conditions) and the approximately the same molecular toluene is soluble
weight distributions (determined according to the method gel permeation chromatography) with the provisos, (I) that the sum of the weights and (III) that the absolute values of the intrinsic 30 parts under (a) and (b) are each 100, (II) that the viscosities ( measured in decalin at 13O ⁰ C) Polypropylene (a) and (b) are both in each case be in the range 1 to 10 approximately the same intrinsic viscosities as well approximately the same molecular weight distributions (determined according to the gel permeation method 35 chromatography) and (III) that the absolute values of the intrinsic viscosities (measured in decalin at 130 ⁰ C) each in the range from 1 to 10, preferably