RU2326139C1 - Heterophase polyolefin mixture - Google Patents

Abstract

FIELD: plastic industry.

SUBSTANCE: mixture consists of crystalline polypropylene, modified olefin copolymers and functional additives. The functional additive is a mixture of a structure-forming agent and a poly-diethyl-silicone liquid with mass ratio of 1.0:0.04-8.0.

EFFECT: stability of the properties of the product during repeated treatment of the mixture at high temperatures.

4 tbl, 5 ex

Description

The present invention relates to the plastics industry and relates to the development of a heterophasic polyolefin (PO) composition for producing products by melt forming, including crystalline polypropylene (PP), modified by double and / or triple copolymers of polyolefins and functional additives.

Known means and goals of structural modification of polymers, providing products from polymer melts with desired properties (Encyclopedia of Polymers. M: Soviet Encyclopedia, t.1, p.843, t.2, s.265, t.3, p.556 )

Known heterophase polyolefin composition comprising crystalline PP with an isotactic index of more than 90, modified with a copolymer containing predominantly ethylene and a copolymer of ethylene and propylene, with the content of the components of the composition, respectively, wt.%: 36.8-46.0: 15.0-20, 0: 37.2-44.2 (RF Patent No. 2085560).

Heterophasic polyolefin compositions are also known, including crystalline PP modified with double and / or triple copolymers of polyolefins and, according to the examples described in the patent specification, modifying functional additives, including structure-forming agents (RF Patents No. 2097391 and No. 2174526), and aimed at structural modification of polyolefin compositions based on PP homopolymer (Patents of the Russian Federation No. 2174526 and No. 2206583) and heterophase mixtures based on copolymers of polyolefins (RF Patent No. 2167897), which provide optimization technological casting processes and properties of finished products.

The above technical solutions use heterophasic polyolefin compositions, the distinguishing feature of which is a high degree of crystallinity of the PP phase (more than 80), and the degree of crystallinity of the amorphous phase is 20-60 or more, and together with the proposed modifiers based on double or triple copolymers ensure the presence in the products obtained from melts, a necessary complex of properties.

The listed technical solutions, having a number of advantages in obtaining products from polymer melts with the necessary set of properties, have the main disadvantage due to the fact that these compositions do not ensure the stability of the properties of the products during their repeated processing at elevated temperatures, because "the uniform distribution of the builders is associated with significant difficulties due to their low content" (Encyclopedia of Polymers. M: Soviet Encyclopedia, v.1, p.843).

Varying the ratio of the degrees of crystallinity of PP in the amorphous and crystalline phases of the compositions in the ranges of known technical solutions in the presence of functional additives of structural modification allows one-time products to be obtained from melts of heterophase compositions in a wide range of consumer properties.

The closest technical solution is a composition based on isotactic (crystalline) PP modified with copolymers of propylene with a diene or a triple copolymer based on propylene, diene and ethylene with a ratio of the components of the composition, respectively, wt.%: 75.0-85.0: 15.0 -25.0 and 20.0-80.0: 0.5-9.0: 19.5-79.5 with the amount of modifier 20.0-65.0% of the total weight of the polymer composition and 5% of functional additives ( RF patent No. 2190636).

However, this composition also does not ensure the stability of the properties of products during repeated processing at elevated temperatures.

The objective of the invention is the development of a heterophasic polyolefin composition for producing products by molding from a melt and ensuring the stability of the properties of the products during repeated processing of the composition at elevated temperatures.

The problem is solved in that the heterophasic polyolefin composition for producing products by molding from a melt, including crystalline polypropylene, modified by double and / or triple copolymers of olefins and functional additives, as the latter contains a mixture of a structurant and polydiethylsiloxane liquid in a ratio of 1.0: 0.04 -8.0, respectively, with the following content of the components of the composition, wt.%:

Crystalline polypropylene  34.32-90.0 Double and / or triple olefin copolymer  9.88-64.38 Specified Functional Additive  0.12-1.3

According to the invention use:

A) Structuring agents with a melting point above 100 ° C.

For example, 2 chloro-4-ethylamino-6-isopropylamino (1,3,5) -triazine (atrazine), 2 chloro-4,6-bis (ethylamino) -1,3,5-triazine (simazine), dibenzoledensorbite , cobalt naphthenate, etc.

B) Polydiethylsiloxane liquid (PES-5)

with a density of 0.99-1.02 g / cm ²

C) Copolymers:

- a double copolymer of ethylene and α-olefin CH ₂ = CHR, where R is C _4-6 straight or branched alkyl. The copolymer can be high and low pressure, for example, high pressure - a linear copolymer of ethylene and 1-octene with a density of 0.89-0.927 g / cm ³ ;

- a triple copolymer based on propylene (93.2-99%), ethylene (0.5-1.9%) and C ₄ -C ₁₀ α-olefin (0.5-4.9%) or (14.5 -60%) propylene, (30.0-85.0%) ethylene and (0.5-10.0%) diene.

Dien: 1,4 hexadiene, dicyclopentadiene, 2-ethyldien 5-norbornene;

- elastomeric copolymers of ethylene, propylene and diene;

- DOW Lex - 2045 - linear low-density polyethylene containing octen-1 comonomer, density 0.92 g / cm ³ ;

- Static copolymers of propylene and ethylene Pzo-fax 861, Hastalen PPU 5736 S2G, Hastalen PPW 1780 S2A;

- Crystal polypropylene "Drop".

The invention is illustrated by examples.

Example 1

A mixture of atrazine and PES-5 in a ratio of 1.0: 0.04 is mixed with crystalline PP in an intense hermetic fluid type mixer with a polished inner surface. The concentrate prepared in the mixer and the main portion of the polyolefin composition are fed into the hot unit of the main mixing of the Henschel type two-chamber mixer, where the polyolefin composition of the following composition is intensively mixed for 5-7 minutes, wt.%:

Crystalline polypropylene  34.32 Copolymer propylene and ethylene (with ethylene content 3.0%)  64.38 Specified Functional Additive  1.3

The polymers used according to the invention contain stabilizing additives introduced into the polymers at the final stages of commercial production. After hot mixing, the composition is fed to a mixer with cooling. Material cooled to 70 ° C with a bulk density of 0.4-0.5 kg / l is fed to a Werner und Pfleiderer twin-screw extruder granulator ZSK with a screw diameter of 28 mm, the intensity of the mixing process in which is especially high, because material due to the small depth of cutting is only in the form of thin film layers.

Temperature in the extruder zones, ° С: 140 (inlet), 200, 260, 280 and 260 (die). A granulate was obtained and samples were taken for further studies after 1, 3 and 10-fold granulation of the composition of the above composition.

The preservation of properties after repeated granulation was judged by the PTR data, g / 10 min, measured at 230 ° С / 2.16 kg. The properties of the granules are presented in table 1, which shows examples of comparison.

Table 1 Mixture components Examples one Comparative Prototype
Pat. RF 2190636 1a 1b wt.% Crystal PP 34.32 34.32 34.32 35.0 Propylene and ethylene copolymer 64.38 64.38 64.38 65.0 Functional Additive 1.3 - - - Atrazine * - - 0.144 - PES-5 ** - 1,156 - - Granulation rate PTR, g / 10 min one 3.4 3,5 3.83 1,56 2 3.4 5,4 6.6 2.9 3 3.6 18.0 Partial destruction Destruction * The effective content of builders is in the range of 0.1-1.0 wt.% (See, for example, US Pat. RF No. 2081132, Encyclopedia of Polymers, t.1, p.843).
** The effective content of microadditives is in the range of 0.02-1.0 wt.% (See, for example, Andrianova G.P., Kargin V.A. DAN USSR, 183, 587, 1968; Naval Forces, A13, No. 7 , 1564, 1971.

Example 2

Analogously to example 1, a heterophase composition composition was granulated, wt.%:

Crystalline polypropylene  90.0 Triple copolymer propylene (50%), ethylene (48%) and diene (2%)  9.88 Functional supplement based dimethyldibenzene-sensorbitol and PES-5 in the ratio respectively 1: 5  0.12

The following data were obtained on the change in melt flow rate:

Multiplicity of a pass PTR, g / 10 min one 2.6 3 2.6 10 2.9

From the granular compositions of Example 2 with the above MFR, g / 10 min sheets were formed through a slit head of an OMV brand extruder 1.5 mm thick and 585 mm wide. The temperature regime of extrusion is presented in table.2.

table 2 Zone I II III IV V Die Head T, ° С 220 230 235 240 240 240 245

On a three-roll calender, the sheets in the free state were drawn at a speed of 3.7 m / min, and after passing through the 3rd cooling shaft, the articles were formed from the sheets. The molding is carried out on an OMV F 25 RIO thermoforming machine at a speed of 16 cycles per minute at an average temperature of the 11-zone top heating of the forming socket 439 ° С and the lower 10-zone 380 ° С. The thickness of the products is 0.2 mm. The properties of the products are presented in table.3.

Table 3 Granulation rate Tensile yield strength, MPa GOST 11262-80 Relative extension, %
GOST 11262-80 Light transmission coefficient GOST 15875-80 one 28.6-29.0 520 90 3 28.6-29.0 520 90 10 28.0-28.3 515 90 Prototype one 27.5 500 65-70 3 Partial destruction

Example 3

According to example 1, a heterophasic polyolefin composition was prepared, wt.%:

Crystalline polypropylene  40,0 Static copolymer polypropylene (2.3% ethylene)  50,0 Triple copolymer according to example 2  9.0 Functional Additive

Simazine (2chloro-4,6-bis (ethylamino) -1,3,5triazine):

PES-5 in a ratio of 1: 8  1,0

The following data were obtained on the change in PTR, g / 10 min (230 ° C / 2.16)

Extraction rate PTR, g / 10 min one twenty 3 twenty 10 21

Prototype - partial destruction after triple granulation.

Example 4-5

Heterophase compositions were prepared, the compositions of which are shown in table 4.

Table 4 The components of the mixture, wt.% Example 4 Example 5 Crystalline polypropylene 34.0 90.0 A copolymer of olefin based on propylene and ethylene with a content of the latter 3% 64.0 9.9 2.0 0.1 Functional supplement of example 2 with the ratio of builder: PES-5 1: 0,02 with the ratio of builder: PES-5 1: 9

The experimental data of examples 4 and 5 showed that when the ratio of the components of the composition of example 4 is not achieved, the stability of the properties of the products during repeated processing is not achieved, and when processing the composition of example 5 in the proposed technological sequence, it is not possible to realize the positive effect of the proposed technical solution (maximum destruction after triple granulation).

Thus, the proposed technical solution allows you to:

- to process secondary polymer raw materials from products obtained from the proposed heterophasic polyolefin composition with various durations and operating conditions into high-grade products with the necessary consumer properties;

- reduce the cost of products due to the exclusion from the formulation of the composition of the source (primary) polymer raw materials.

Claims (1)

A heterophasic polyolefin composition for producing melt-molded articles, including crystalline polypropylene, modified by double and / or triple olefin copolymers and functional additives, characterized in that the composition contains a structure-forming agent and polydiethylsiloxane liquid in a ratio of 1.0: 0.04 as a functional additive -8.0, respectively, with the following content of the components of the composition, wt.%: crystalline polypropylene 34.32-90.0 double and / or triple olefin copolymer 9.88-64.38 specified functional additive 0.12-1.3