RU2564326C2 - Polymer composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: composite material is obtained by modification of polyethyleneterephthalate with modifying composite, which has polyhydroxyether and organic clay as its components.

EFFECT: invention provides obtaining bottles, which possess improved barrier properties.

2 tbl

Description

The present invention relates to composite materials based on polyethylene terephthalate (PET), intended for the manufacture of single-layer containers in the form of bottles with enhanced barrier properties.

Bottles made of polyethylene terephthalate (PET) have numerous fields of application due to their excellent characteristics: resistance, lightness, transparency, organoleptic properties. These bottles are manufactured at high speed by biaxial drawing of a preform in a mold. Despite its desirable characteristics, the lack of a gas barrier to PET for oxygen and carbon dioxide limits the use of PET for small packaging, as well as for packaging oxygen-sensitive products such as beer, juice and tea products. In this regard, in the packaging industry there is a pronounced need for further improvement of the gas-barrier properties of PET.

In order to improve the gas-barrier properties of composite materials intended for PET containers, many researchers use modifier complexes. Thus, a polymer composition based on polyester (in particular, polyethylene terephthalate) is known according to RF patent No. 2324712, which incorporates the following modifiers: partially aromatic polyamide, ion component that improves miscibility, and cobalt salt. As an ionic component, the inventors propose using a copolyester containing a metal sulfonate salt. Despite the large number of advantages of the composite material according to the invention, there is a significant drawback - the use of rather expensive substances as modifiers.

The closest to the proposed combination of known features is a polyester composition with low molecular weight additives, designed to improve gas impermeability, intended for films, pipes, bottles, preforms and profiles, incorporating polyethylene terephthalate and a diamide-containing additive in the following ratio, wt.%:

PAT 94.0-99.5 diamide-containing additive 0.5-6

The main disadvantage of this composition is not high enough in terms of gas permeability (US patent application No. 2012199515, IPC В29В 7/00; В29С 39/00; В29С 45/46; В29С 47/00; В29С 49/04; В29С 49/08; B29C 51/00; B65D 23/00; C08L 35/02).

The objective of the invention is the creation of a polymer composition based on polyethylene terephthalate, intended for the manufacture of single-layer containers in the form of bottles with improved gas barrier properties.

To solve the above problem, the present invention provides a polymer polyethylene terephthalate composition comprising polyethylene terephthalate and a modifying composite in the following ratio, wt.%:

PAT 94-99 modifying composite 1-6

In turn, the modifying composite incorporates a polyhydroxyether and organoclay in the following ratio, wt.%:

polyhydroxyether 75-90 organoclay 10-25

In the specified composite material, it is preferable to use polyethylene terephthalate granulate SPET 8200 grade L and a polyhydroxyether with the general formula

Where R is the remainder of bisphenol A

Montmorillonite of the Herpegezh deposit of the Kabardino-Balkarian Republic with a cation exchange capacity of 95 mEq / 100 g clay, previously purified from ballast substances in a hydrocyclone and modified with KATAPAV or KATAPAV / caprolactam mixture at a ratio of 1: 2 in the amount of 30% by weight of mantmorillonite, is used as organoclay. Moreover, the used KATAPAV has the general chemical formula

The modifying composite is obtained by extrusion mixing a polyhydroxyether and organoclay at a temperature of 180-220 ° C.

The invention is illustrated by the following examples.

An example of obtaining a composite material. Polyethylene terephthalate and a modifying composite are sequentially loaded into a mixer heated to 35 ° C. The resulting mixture is poured into an extruder and processed in zones I-VI at temperatures of 235 ° C, 240 ° C, 250 ° C, 260 ° C, 270 ° C, 275 ° C, respectively.

To obtain the composite material, standard laboratory equipment was used: a mixer, an extruder, and well-known methods of testing the obtained materials and the equipment corresponding for these purposes:

- O ₂ permeability index, cm ³ / m ² , over 24 hours at 23 ° C;

- CO ₂ permeability index, cm ³ / m ² , over 24 hours at 23 ° C;

- vapor permeability, g / m ² , over 24 hours at 90% relative humidity and a temperature of 38 ° C, measured in accordance with DIN 53 380 T.2 - ASTM D 1434-M.

The composition and properties of the composite material are shown in tables 1 and 2.

EFFECT: obtaining a composite material based on polyethylene terephthalate with improved barrier properties — oxygen permeability of 18 cm ³ / m ² in 24 hours, CO ₂ permeability _of 8.4 cm ³ / m ² in 24 hours, vapor permeability of 12 cm ³ / m ² in 24 hours.

Claims (1)

A polymer composition based on polyethylene terephthalate for the manufacture of single-layer containers in the form of bottles, characterized in that it further comprises a modifying composite in the following ratio, wt.%:
PAT 94-99 modifying composite 1-6,
the modifying composite used includes polyhydroxy ether and organoclay in the following ratio, wt.%:
polyhydroxyether 75-90 organoclay 10-25,
used polyhydroxyether has the general formula

the organoclay used is montmorillonite of the Herpegezh deposit of the Kabardino-Balkarian Republic with a cation exchange capacity of 95 mEq / 100 g of clay, modified by KATAPAV or KATAPAV / caprolactam mixture at a ratio of 1: 2 in the amount of 30% by weight of montmorillonite.