DD298799A5 - STABILIZER LUBRICANT SYSTEM FOR POLYMERS OF VINYL CHLORIDE - Google Patents

Abstract

The invention relates to a stabilizer-lubricant system based on calcium compounds, hydrocarbons, optionally further lubricants and co-stabilizers, which is used in the PVC soft and hard processing. The essence of the invention is that the calcium compounds are present as a calcium stearate-coated finely dispersed combination of calcium hydroxide, calcium carbonate and calcium sulfate. When using the inventive stabilizer-lubricant system resulting from improved initial color, high residual stability and improved rheological properties comprehensive application possibilities of such stabilized PVC molding compositions {stabilizer-lubricant system; Calcium compounds; hydrocarbons; Lubricant; co-stabilizers; Soft PVC processing; Rigid PVC processing; calcium stearate; Coating; finely dispersed combination; calcium hydroxide; rheological properties}

Description

Field of application of the invention

The invention relates to a stabilizer-lubricant system for polymers of vinyl chloride, which consists of calcium compounds, hydrocarbons and optionally further lubricants and co-stabilizers and which is used in the PCV processing, especially soft PVC.

Characteristic of the known state of the art

The use of both stabilizers and lubricants in PVC processing has been known for some time and is described in detail in the relevant literature.

More recently, especially those stabilizer-lubricant combinations gain importance, which have no toxicity and are therefore widely available. In this context, predominantly calcium compounds assume a dominant position, in particular Calciunicarboxy late or corresponding combinations with these outweigh. However, stabilizer-lubricant combinations based on calcium compounds are known in which inorganic versus organic calcium compounds quantitatively clearly outweigh.

In DD-PS 160455 and 160456 such combinations are described in which calcium stearate is bound differently to the quantitatively predominant calcium hydroxide. The resulting benefits, such as high stabilizer efficiency, thermal stability and impact resistance, generally occur but, on the other hand, require a relatively high level of basic calcium compounds. This requirement is particularly relevant to achieving high residual stability, in part in favor of the initial color. This dominance of calcium hydroxide also adversely affects the theological properties, so that the systems described in DD-PS160455 and 160456 are not accessible to all applications.

Object of the invention

The aim of the invention is to remedy the disadvantages resulting from the relatively high proportion of inorganic basic calcium compounds in terms of initial color in stabilizer-lubricant systems based on calcium compounds, hydrocarbons and optionally other lubricants and costabilizers or to eliminate as far as possible. '

Another object of the invention is to improve the theological properties in terms of a comprehensive applicability of the PVC molding compositions.

Explanation of the essence of the invention

The invention is therefore based on the object to develop by changing the components of a stabilizer Gaitmittel system, which corresponds to the aforementioned objectives.

According to the invention, stabilizer-lubricant systems consisting of calcium compounds, hydrocarbons and optionally further lubricants and co-stabilizers, for polymers of vinyl chloride with improved initial color and rheology, if within the system, the calcium compounds as a coated with calcium stearate, finely dispersed combination of calcium hydroxide, calcium carbonate and Calcium sulfate present.

It is essential to the invention that calcium hydroxide predominates within the calcium compounds, with a proportion of between 30 and 60% having proven advantageous.

Also significant in terms of quantity is the proportion of calcium carbonate in the coated combination, which should be between 25 and 55%. The stabilizer-lubricant system according to the invention is characterized by the reduced calcium hydroxide by an improved initial color, without the residual stability is impaired. Rather, the residual stability in the PVC soft processing could even be slightly increased, which in combination with improved rheological properties result in wider applications of the PVC molding mass.

embodiments

1. To 100 parts of PVC-S (K value 65) and 50 parts of dioctyl phthalate are added 3 parts of a stabilizer-lubricant system consisting of

60.0% hydrocarbon wax,

31.0% of a combination of 5 parts of calcium hydroxide, 4 parts of calcium carbonate, 0.3 parts of calcium sulfate and 1 part of calcium stearate,

2.5% zinc stearate and 6.5% trimethylolpropane added.

After homogenization in the intensive mixer, the dryblend is processed into a cable sheath by means of an extruder. The measured values (flow value, initial color, residual stability) determined during processing and on the finished product are given in Table 1.

In addition, the cable sheath obtained by a spec. ^Volume resistivity of ^{2.2-10 l3} ohms. This value guarantees according to TGL 200-1612 / 02 or VDE 0207 sufficient insulating properties of the cable sheathing.

2. To 100 parts of PVC-S (K value 60) are 2.5 parts of a stabilizer-lubricant system consisting of

68% carbohydrate wax,

19% of a combination of 6 parts of calcium hydroxide, 2.5 parts of calcium carbonate, 0.1 part of calcium sulfate and 1.5 parts of calcium stearate.

4% zinc stearate and 9% mannitol added.

After intensive mixing, the plasticized molding compound is processed on a calender to 200 μηι thick hard film. The measured values obtained during processing and testing on the finished product are also in Table 1

demonstrated.

The PVC hard film is characterized by significantly improved migration resistance and is thus for the packaging

suitable for food.

3. To 100 parts of PVC-S (K value 60) is added 2.8 parts of a stabilizer lubricant system consisting of 50% hydrocarbon wax,

44% of a combination of 3 parts of calcium hydroxide, 5.5 parts of calcium carbonate, 0.5 part of calcium sulfate and 0.4 part of calcium stearate,

1% zinc stearate and

5% pentaerythritol added.

After homogenization by means of an intensive mixer, the dry blend is extruded by means of a twin-screw extruder to pressure tubes with 110 mm diameter and 5.4 mm wall thickness.

The measured values obtained during processing and testing on the finished product are also given in Table 1. The PVC pipes were also characterized by very high pressure resistance during control tests according to TGL11689. For comparison, 100 parts PVC-S (K value 67) with 2 parts of a stabilizer-lubricant system consisting of 49.0% hydrocarbon wax, 40.0% calcium hydroxide

8.0% zinc stearate and 3.0% dilauryl thiodipropionate homogenized in the intensive mixer.

The dryblend is then processed into a cable sheath by means of an extruder.

The measured values obtained during processing and on the finished product are shown in Table 1. * When testing the insulation ^properties , a specific volume resistance of 1.1 10 ^l2 ohms was determined, which does not meet the requirements of TGL 200-1612 / 02 or VDE 0207.

Furthermore, for comparison, 100 parts PVC-S (K value 60) with 2.5 parts of a stabilizer-lubricant system consisting of

69% lubricant mixture (hard paraffin and low molecular weight polyethylene in the ratio 4: 1) 15% calcium hydroxide

11% magnesium laurate

5% aminocrotonic acid ester

mixed intensively and processed on a calender to a 200pm thick hard film.

The measured values obtained during processing and on the finished product are likewise contained in Table 1.

When calendering a strong tendency to sticking of the film ayrf occurred on the calendar rollers , which is particularly bad

Surface quality of the film and in extreme cases led to cracks in the film web.

Table 1

Properties / parameters

Exemplary embodiments 1 2 3

Comparative Examples 1 2

Flow value after initial color SYNMERO® residual stability on molding (min) at 185 ⁰ C

1.5 1 46

1,8 2

70

2.6 3

49

3.9 2 41

Claims (3)

A stabilizer-lubricant system for polymers of vinyl chloride consisting of calcium compounds, hydrocarbon waxes and other lubricants and co-stabilizers, characterized in that the calcium compounds are present as a calcium stearate-coated finely dispersed combination of calcium hydroxide, calcium carbonate and calcium sulfate in the stabilizer-lubricant system , 2. stabilizer-lubricant system according to claim!, Characterized in that the proportion of calcium hydroxide in the coated combination is 30-60%. 3. stabilizer-lubricant system according to claim 1 and 2, characterized in that the proportion of calcium carbonate in the coated combination is 25-55%.