WO2008034716A1

WO2008034716A1 - Use of ethoxylated alkylamines for modification of the surface tension of plastics

Info

Publication number: WO2008034716A1
Application number: PCT/EP2007/059228
Authority: WO
Inventors: Thomas Enge
Original assignee: Clariant International Ltd; Clariant Finance (Bvi) Limited
Priority date: 2006-09-22
Filing date: 2007-09-04
Publication date: 2008-03-27
Also published as: TW200829636A

Abstract

The invention relates to the use of ethoxylated alkylamines for modification of surface tension, for example for hydrophilizing and for improvement of wettability, of plastics surfaces.

Description

USE OF ETHOXYLATED ALKYLAMINES FOR MODIFICATION OF THE SURFACE TENSION OF PLASTICS

The invention relates to the use of ethoxylated alkylamines for modification of surface tension, for example for hydrophilizing and for improvement of wettability, of plasties surfaces.

The plasties surfaces whose surface tension is modified are hereinafter called surfaces ofpolymers.

Surface tensions of surfaces ofpolymers are modified in order, for example, to change the shape of water droplets on the surface ofpolymers so that a larger area is wetted.

This involves hydrophilizing of the surface ofpolymers, bringing about improved water- wettability. This process increases the surface area of the water droplet and reduces the energy required to remove the droplets by drying, and the surface dries more rapidly. Examples of these modified surfaces are horizontally mounted plastics components in dishwashers.

Conventional processes for modification of surface tension in plastics that are known are corona treatment and flame treatment and are described on page 159 et seq. of "Kunststofffolien (Herstellen-Eigenschaften.-Anwendungen)" [Plastics films (production, properties, applications)] by Nentwig, Hanser Verlag.

There was a need for a process which is easy to use during the conventional processing ofpolymers and which can modify the surface tension of surfaces ofpolymers.

Surprisingly, it has been found that certain ethoxylated alkylamines can modify the surface tension of surfaces ofpolymers.

The invention provides the use of compounds of the formula (A)

as additives for modification of the surface tension of surfaces of polymers; where R¹ is Ci₆-i₈-alkyl.

The compounds of the formula (A) are commercially available, for example as Hostastat® FA 68 Solid (Clariant) and Armostat® 600 (Akzo Nobel).

The expression Ciβ-is-alkyl for the group R¹ in the formula (A) means that R¹ can have been selected from the group Ciβ-alkyl, Cπ-alkyl and Cis-alkyl, preferably from Ci6-alkyl and Cis-alkyl, and from mixtures of these alkyl groups. The alkyl groups can be linear or branched, preferably linear, and saturated or unsaturated. The compounds of the formula (A) can also derive from fatty amines of natural origin, these usually being composed of mixtures of compounds of various chain lengths. The proportion of the fraction where R¹ = Ciβ-is-alkyl in the mixture is preferably at least 50% by weight, particularly preferably at least 75% by weight, in particular at least 85% by weight, based in each case on the total weight of the mixture; and the mixture can also comprise compounds whose alkyl chain sizes are smaller than 16 carbon atoms and/or larger than 18 carbon atoms.

The invention further provides a process for modification of the surface tension of surfaces of polymers, where the compounds of the formula (A) are added to the polymer prior to or during the processing of the polymer.

Polymers whose surface tension is modified via use of the compounds of the formula (A) are preferably organic polymers, preferably from the group of polyolefϊns, preferably polypropylenes (PP) and polyethylenes (PE), or else copolymers of ethylene and propylene, polystyrenes (PS), polystyrene block copolymers, preferably acrylonitrile-butadiene-styrene (ABS), blends of ABS with polyamide (PA) and blends of ABS with polycarbonate (PC), particularly preferred polymers being polypropylene, polyethylene and copolymers of ethylene and propylene, in particular copolymers of ethylene and propylene.

The plastics or polymers equipped with the compounds of the formula (A) can also comprise fillers and reinforcing materials, e.g. glass fibres or talc. These plastics or polymers can likewise comprise further additives, such as antioxidants, light stabilizers, such as UV absorbers or hindered amine stabilizer (HAS) (also called hindered amine light stabilizer (HALS)), nucleating agents, organic and/or inorganic pigments.

The compounds of the formula (A) can be used directly, in the form of concentrates, called a masterbatch, or in the form of a mixture with other substances, preferably with other plastics additives. They are preferably used directly or in the form of a masterbatch, particularly preferably directly. If the material is used in the form of concentrate or mixture, the concentrate or the mixture preferably comprises at least 5% by weight, particularly preferably at least 10% by weight, in particular at least 30% by weight, specifically at least 50% by weight, based in each case on the total weight of the concentrate or of the mixture, of the compound of the formula (A); and it is preferable here that, as upper limit, the concentrate comprises up to 80% by weight, based on the total weight of the concentrate, of the compound of the formula (A).

The compounds of the formula (A), or the masterbatches or the mixtures with the compounds of the formula (A), are used in solid or liquid, for example molten, form, preferably in solid form. In solid form, the compounds of the formula (A) or the masterbatches or the mixtures with the compounds of the formula (A) are preferably used in the form of pellets or powder.

In order to produce the plastics, and preferably in order to produce plastics injection mouldings and plastics films, in particular to produce plastics injection mouldings, with modified surface tension, the compounds of the formula (A) are mixed with the polymer. This mixture is processed to give semifinished products, films and finished components, preferably via extrusion, in particular flat-film extrusion (cast films), blown- film extrusion and injection moulding. The compounds of the formula (A) or their masterbatches or the mixtures comprising compounds of the formula (A) are added to the polymer prior to or during the processing of the polymer to give the semifinished product, or finished component, or to give the film, preferably prior to or during the extrusion process via direct addition of the compounds of the formula (A) or of their masterbatches or of the mixtures comprising compounds of the formula (A) to the polymer melt.

The amount used of the compounds of the formula (A) is preferably from 0.05 to 5% by weight, particularly preferably from 0.1 to 2% by weight, in particular from 0.1 to 1.5% by weight, based in each case on the weight of the polymer, either directly or as a masterbatch or as a mixture comprising compounds of the formula (A).

The precise amount to be used of compounds of the formula (A) depends on the magnitude of the desired surface tension and is selected appropriately by the person skilled in the art.

It was surprising that the compounds of the formula (A) affect the surface tension of surfaces of polymers or of plastics. It was moreover not foreseeable that the effect is specifically dependent on the chain length of the alkyl group R¹.

Examples

The stated amounts in percent of the substances used in the examples are % by weight, and the % by weight data are based on the weight of the polymer unless expressly otherwise stated.

Surface tension test method

The surface tension was determined to DIN EN 828. Unlike in the standard mentioned, the test substances used were water, glycerol and ethylene glycol.

A mixture composed of 30% by weight of talc and also of the amount stated in Table 1 of additives whose descriptions are found in Table 2 was added via side feed to a propylene-ethylene copolymer (Moplen® EP 440G, Basell) in a twin-screw extruder. The compounded material produced was pelletized and then the pellets were used to produce 8 x 8 mm sheets of thickness 2 mm via the injection moulding process. On the sheets comprising the compound (I) it was found that the shape of water droplets was changed in such a way that a larger area was wetted, and that the water droplets did not have the typical spherical shape. Subsequent measurements of the respective surface tensions on the sheets gave markedly higher surface tensions than those expected for the polypropylene sheets. The value for untreated polypropylene is usually from 30 to 32 mN/m.

Claims

1. Use of compounds of the formula (A)

for modification of the surface tension of surfaces of polymers; where R¹ is Ci6-i8-alkyl.

2. Use of compounds of the formula (A) according to Claim 1, where the compounds of the formula (A) are added to the polymer prior to or during the processing of the polymer.

3. Use of compounds of the formula (A) according to Claim 1 or 2, where the polymers have been selected from the group of polyolefms, copolymers of ethylene and propylene, polystyrenes, polystyrene block copolymers, blends of acrylonitrile- butadiene-styrene with polyamide and blends of acrylonitrile-butadiene-styrene with polycarbonate.

4. Use of compounds of the formula (A) according to one or more of Claims 1 to 3, where the amount used of the compounds of the formula (A) is from 0.05 to 5% by weight, based on the weight of the polymer.

5. Use of compounds of the formula (A) according to one or more of Claims 1 to 4, where the polymers comprise fillers and reinforcing materials, additives, nucleating agents, organic and/or inorganic pigments.

6. Use of compounds of the formula (A) according to one or more of Claims 1 to 5, where the compounds of the formula (A) are used directly, in the form of a masterbatch or in the form of a mixture with other substances.

7. Use of compounds of the formula (A) according to Claim 2, where the polymer is processed via extrusion.