This invention relates to a polypropylene composition which shows a good affinity for dispersion dyes and which comprises an isotactic polypropylene basic polymer and at least a copolyamide as dyeability additive.

Due to its strongly hydrophobic character, polypropylene shows no or only a limited affinity for dyes. As a result of this, the dying and printing of polypropylene by means of the conventional means which are applied with other synthetic fabrics such as polyesters, polya ides, polyacrylates, or with natural fibres such as wool and cotton, is not possible.

Momentarily, polypropylene material mostly is pigmented in the mass during the extrusion process. This process economically makes sense for large production batches only. This limits the flexibility in the choice of colours and also excludes the application of printing technology.

Due to this, a widespread interest does exist, and various attempts were made in order to create a traditionally dyeable polypropylene.

The use of dyeability additives is mostly preferred in comparison to the use of special dyes which are expensive, or the inoculation of dye receptors onto the surface of the polypropylene, which is expensive and yields products with a limited dyeability and with a weak colour fastness.

The use as additives of polar polymers containing acid or

basic groups, as described in the American patents Nos. 3.328.484, 3.433.853, 3.465.060 and 3.686.848, results in a polypropylene which is only dyeable by means of acid or basic dyes.

This is also the case with the polypropylene composition with a copolyamide additive which is described in the Canadian patent application No. 2.047.791. This composi¬ tion contains 85 to 96 % isotactic polypropylene and 4 to 15 % copolyamide which is a reaction product of N-(2- aminoethyl) piperazine adipamide, hexamethylene adipa ide and, eventually, a caprolactam, or 4 to 15% of a copolymer, consisting of hexamethylene adipamide and an equimolar mixture of hexamethylene diamine and a derivate of alcali salt of 5-sulpho-isophtalic acid.

This composition is only dyeable by means of acidic dyes.

The afore ented percentages and all percentages given hereafter are weight percentages, if not mentioned otherwise.

The Japanese patent application No. 05-209.311 A2 describes a dyeable ternary polypropylene composition, consisting of 55-89 % polypropylene, 10-45 % linear aliphatic polyamide and 1-40 % modified polyolefine, being essentially isotactic polypropylene, inoculated with 0,35 % aleic acid anhydride.

Up to now, all these compositions have found little or no industrial application, due to an insufficient compatibi¬ lity of the components, resulting in problems with the manufacture and/or processing of the compositions, or due to their insufficient mechanical properties.

The invention aims at a polypropylene composition which

does not show these or other disadvantages and can easily be dyed or printed with dispersion dyes and furthermore is easily processable into fibres or films and has good mechanical properties.

According to the invention, this aim is reached by a polypropylene composition which

a. comprises 80 to 99 % isotactic polypropylene basic polymer,

b. comprises 1 to 10 % copolyamide component, consisting of the polycondensation products of at least two materials from the group, formed by: lactams, containing 6 to 12 carbon atoms, aminocarbonic acids, containing 6 to 12 carbon atoms, and equimolar quantities of a diamine, containing 4 to 12 carbon atoms, and a diprimary carbonic acid with 6 to 36 carbon atoms, and

c. comprises 0 to 10 % ethylene/vinyl acetate (EVA) copolymer which contains 18-33 % (calculated on the basis of the EVA copolymer) vinyl acetate units,

whereby all % are weight percentages.

The invention also refers to a material, for example, a textile material, manufactured of a composition as described heretofore.

With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, several preferred forms of embodiment of a dyeable and printable composition according to the invention are represented.

In a first series of embodiments, the polypropylene

composition according to the invention consists of:

- 90 to 99 % isotactic polypropylene basic polymer, eventually comprising the usual functional additives, and

- 1 to 10 % copolyamide component, consisting of the polycondensation products of:

- 20 to 90 % (calculated on the quantity of copolyamide) of at least one lactam or aminocarbonic acid (preferably linear and aliphatic), containing 6 to 12 carbon atoms, and — 80 to 10 % (calculated on the quantity of copolyamide) of equimolar quantities of a diamine, containing 4 to 12 carbon atoms and a diprimary carbonic acid with 6 to 36 carbon atoms.

Isotactic polypropylene which is suitable for the compositions according to this invention is commercially available and may strongly vary in respect to the degree of stereospecificacy (expressed in %), molecular weight distribution and rheological characteristics. Very suitable is polypropylene with an isotacticity of 90 to 99 %, preferably 95% or more, and with an MFI (Melt Flow Index) in the range between 4 and 45.

The selection of the polypropylene takes place according to general methods, known by those skilled in the art, based on the desired technical features of the composi¬ tion, their technical application and the kind of the used extrusion machinery.

The copolyamide component is obtained by polycondensation of a suitable monomere mixture, preferably a monomer mixture containing a considerable part, for example, more than 10%, preferably 20 to 40%, units with a linear aliphatic chain with 8 to 12 carbon atoms, preferably 12 carbon atoms, and which does not comprise any important quantities of ionic groups. These copolyamides are

commercially available. Typical copolyamides, suitable as component for the compositions of the invention, are, for example, polyamides (PA) of the nylon type which are the polycondensation product of monomer mixtures PA6/PA6.6/ PA12 with a composition (in weight percentage) of 40:20:40 and 40:40:20.

The diamine in the copolyamide component may be a dipri- mary amine or a disecondary, for example, piperazine.

Preferred embodiments according to this invention are compositions wherein the copolyamide component consists of a copolyamide wherein the quantity of the above-men¬ tioned lactam or carbonic acid component is 20 to 60 %, and compositions wherein the above-mentioned lactam or carbonic acid consists of a mixture of at least 2 cyclolactams or linear aliphatic animocarbonic acids.

Further preferred embodiments are compositions wherein the above-mentioned lactam or carbonic acid component of the copolyamide component contains a quantity of 15 to 60 % (of the total weight of copolyamide) 11-aminoundecanic acid and/or 12-aminododecanic acid.

Particularly good dyeable compositions with good processability are obtained when using a copolymide component containing piperazine groups.

The copolyamide component preferably has a relative viscosity n rel of 1,4 to 1,9, measured according to DIN 53727 (m-cresole; c=0,25 g/50 ml; Ubbelohde viscosity meter; capillary II; 25°C).

The molecular weight distribution of the copolyamides in which the individual polyamide segments may be present as well in ordered form as in a random order, does not have

an essential influence upon the dyeability and only a relatively small influence upon the processability of the formulations.

The suitable copolyamides are commercially available.

Polypropylene compositions according to the invention, consisting of a polypropylene component and a copolyamide component, are good dyeable and printable and have good mechanical and physical qualities. This has the effect that these compositions are extremely suitable for processing by means of extrusion to a variety of fibres, yarns, ribbons and films.

In a second series of embodiments of the invention, the polypropylene composition comprises besides the poly¬ propylene component and polyamide component also 1 to 10 % (based on the total composition) ethylene/vinyl acetate (EVA) copolymer which contains 18 to 33 % (based on total EVA copolymer) vinyl acetate.

The EVA copolymer preferably has a MFR (Melt Flow Range) value of 3-8 g/10 min at 190°C and at a pressure of 21,2 N (2,16 kg), measured according to ISO 1133, a density of 0,93 to 0,96 g/cm ³ , measured according to DIN 53455, and a VICAT point of 35 to 65 ^β C, measured according to DIN 53460.

Extremely suitable EVA copolymers are those which comprise 27 to 29% vinyl acetate and/or have a MFR value of 5 to 8 g/10 min.

Suitable EVA copolymers are commercially available.

The polypropylene polymer, as well as the copolyamide component and the EVA copolymer and/or the compositions

thereof, can also contain processing and functional additives which normally are used during the preparation of the polymers and the compositions, and which are well- known to those skilled in the art, such as, for example, anti-oxidantia, UV stabilisators and flame-retardant additives.

Particularly preferred compositions comprise 1 to 10%, preferably 3 to 7%, and in particular approximately 5 % EVA copolymer.

Such compositions comprise, for example, 85 to 99% isotactic polypropylene, 1 to 10 % copolyamide, containing 20 to 40% amide units with 12 carbon atoms (PA12), or a copolyamide containing piperazine groups, and 1 to 10 % and preferably approximately 5 % EVA copolymer.

The heretofore described compositions according to both series can be mixed according to known techniques, such as, for example:

- by mechanical mixing of the composing components, followed by extrusion of the mixture;

- by mixing of the composing components in a "Melt Blending" process (compounding);

- by mixing of the composing components during the direct extrusion of the desired fibres, yarns and films;

- by previous preparation of a concentrated mixture (in the form of a pre-mix or melt-blend) of copolyamide and (EVA) copolymer components, and mixing of this mixture with the polypropylene component during the later extrusion. Previous mixing of the components and

compounding is preferred, as this technique, in further processing by means of extrusion, allows for the fabrication of fibres with a very good homogeneity and reproducibility.

The polypropylene compositions according to the invention may be processed by means of generally known techniques, particularly by means of extrusion, to a variety of fibres, for example, staple fibres, either textured or not, CF (continuous filament) yarns and BCF (bulked continuous filament) yarns, and to polypropylene films either fibrillated or not.

However, in consideration of the fact that the polyamide component, in separate form as well as in the form of a concentrated mixture or a mixture of all components of the composition, can take up water, for example, from the air, the components and component mixtures have to be dried previously and the absorption of water during the extrusion process has to be excluded by working under a dry nitrogen atmosphere and/or by limiting the contact time of the components with the surrounding air to less than approximately 60 minutes.

These techniques are generally known to those skilled in the art and are applied, for example, for the extrusion of polyamides.

The mechanical, physical and technical qualities of the obtained fibres and yarns can be compared to those of fibres and yarns obtained by extrusion of standard (pure) polypropylene. They can then be processed under circumstances comparable to those which are used for the processing of standard (pure) polypropylene and known to those skilled in the art.

The fibres and yarns which are produced starting with compositions according to the invention, can be used in a variety of applications, a.o. for the production of textiles, such as the spinning of staple fibres to pure or mixed yarns, the yarns can be woven, knitted or connected to clothes, upholstery and furniture fabric, household and technical textiles, and for the fabrication of carpets, woven or tufted floor coverings. Staple fibres can also be used for the fabrication of needled felt and non-woven products.

The polypropylene compositions according to the invention have a good affinity for a whole series of dispersion dyes and can be dyed and printed by means of the known techniques. The temperature during dying and printing may vary strongly, depending on the applied method, and vary, for example, from 80 to 130°C. After dying, the polypropylene material must be rewashed, and a reductive cleaning has to be applied in order to remove the surplus dye, which is adsorbed at the surface of the material.

Dying and printing of these compositions can be performed with fibres as well as with yarns, woven and knitted textile material, non-woven textile material, tufted carpets, and needled felt.

The invention shall be further illustrated by means of the examples following hereafter, whereby the examples Al and Bl are taken as a reference and are not according to the invention.

The testing of the processability and dyeability of the examined polypropylene compositions was performed, if not mentioned otherwise, according to the general ethodes indicated below.

The mixing of the composition:

First of all, the components of the composition were separately dried and subsequently mixed in the suitable ratio. The obtained mixture then was further homogenized and compounded in an extruder with a single transport and mixing screw (Axon laboratorium compounder). The mixture was melted and extruded at a temperature of 230 °C, if not mentioned otherwise. Then the extrudate was cooled down in water and cut into grains. After drying of the grains, the composition was ready for the extrusion to fibres.

The compounding might also have been performed with other compounding systems, such as, for example, with a Bernsdorf compounder.

The compounded compositions then have been extruded by means of an extruder with a single transport and mixing screw (Type: Plasticisers Lab-line MK1; screw charac¬ teristics: nitrated steel, diameter 22 mm, L/D ratio 21/1). An extrusion plate, provided with 120 circle- shaped openings, was used. If not mentioned otherwise, the extrusion temperature was 230 °C. The obtained fila¬ ments were subjected to an extension by a factor 4. In this manner, fibres were obtained of approximately 40 dtex/filament.

During the extrusion was inspected whether problems occurred, such as breaking of the filament and irregula¬ rities in the thickness of the filament, which indicates a bad compatibility of the applied composition.

The physical characteristics (tensioning force and extension) of the extruded fibres were tested by means of

an Instron apparatus.

Testing of the dyeability.

The dyeability of the compositions was tested on laboratory's scale in the following manner:

A dye bath was prepared, consisting of 100 ml water, acidified with ethanoic acid to a pH value of 5, whereto

1 gram per litre dispersion agent was added. Into this bath, 5 g of fibres were added which were obtained by means of the aforementioned method. Then the bath was heated up to 70 °C, and 0,05 g dyeing agent, namely Cetylon Blue BR (Cl Disperse Bleu 3), were added. The bath was heated further with a speed of 2 ^° C/minute to

100 °C, was kept 30 minutes at 100 °C and then cooled down in 10 minutes to 70 "c. Then, the dye bath was removed, and after rinsing and a reductive rinsing with a solution of 2 g/1 hydrosulphite (Na ₂ S ₂ 0 ₄ ), the fibres were dried.

The dyed fibres were inspected by means of a spectrophotometer (ACS colour matching system) , and the colour intensity was examined, whereby use was made of the sum of the K/S values, determined with different wavelengths.

Actual examples.

The following examples A.2 to A.10 and B.2 to B.14 illustrate the present invention and represent various compositions according to the invention. The examples Al and Bl are reference compositions which are not within the scope of the invention.

The results of the compounding, extrusion and dyeability tests, performed as described heretofore, are summarized ⁱ n the table, represented hereafter.

In the compositions described hereafter, the polypropylene PP. _{if not men} tioned otherwise, is of commercial quality with an isotacticity of 96' and a MFI equal to 12, whereas n rel is the aforementioned relative viscosity.

A. Compositions with different (co)pol amides

Example A.I (as a comparison) 100 % PP

Example A.2 97 % PP

3 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40 % n rel = 1,55

Example A.3 97 % pp

3 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 %. n rel = 1,71

Example A.4 97 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 % n rel = 1,87

Example A.5 97 % PP

3 % copolyamide

composition PA 6/PA 66/PA 12 of 6/54/40 %. n rel = 1,82

Example A.6 97 % PP

3 % copolyamide composition PA 6/PA 66/PA 12 of 40/40/20 %. n rel = 1,72

Example A.7 97 % PP 3 % copolyamide (composition piperazine 12/piperazine 9/PA 11 of 70/15/15 %) . n rel = 1,60

Example A.8 99 % PP 1 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40 %. n rel - 1,55

Example A.9 97 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 %. n rel = 1,55

Example A.10 90 % PP

10 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 %. n rel = 1,55

B. Compositions with addition of copolyamides and of ethylene/vinyl acetate (EVA) component:

In the examples described hereafter, the EVA, if not mentioned otherwise, contains 28% of vinyl acetate units, in grain form)

Example B.l (as a comparison) 95 % PP 5 % EVA

Example B.2 92 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 %

5 % EVA n rel = 1,55

Example B.3 92 % PP

3 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40 %

5 % EVA n rel = 1,55

Example B.4 92 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40 % 5 % EVA n rel = 1,87

Example B.5 92 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 Of 6/54/40 %

5 % EVA n rel = 1,82

Example B.6 92 % PP

3 % copolyamide composition PA 6/PA 66/PA 12 of 40/40/20 %

5 % EVA n rel = 1,72

Example B.7 92 % PP 3 % copolyamide (composition with piperazine) 5 % EVA n rel = 1,60

Example B.8 94 % PP 1 % copolyamide

(composition with piperazine) 5 % EVA n rel = 1,60

Example B.9 98 % PP

1 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40

1 % EVA n rel = 1,55

Example B.10 94 % PP 1 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40

5 % EVA

n rel = 1 , 55

Example B.ll 96 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40 % 1 % EVA n rel = 1,55

Example B.12 92 % PP

3 % copolyamide composition PA 6/PA 66/PA 12 Of 40/20/40 %

5 % EVA n rel = 1,55

Example B.13 87 % PP 3 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 %

10 % EVA n rel = 1,55

Example B.14 85 % PP

10 % copolyamide composition PA 6/PA 66/PA 12 of 40/20/40 % and 5 % EVA. n rel = 1,55

Table: Results, obtained with the tested compositions.

Ex. Processa¬ Tension Elongation Colour

NO. bility force at rupture intensity

N/Tex (%) sum K/S

Al good 1,61 120 44

A2 good 120

A3 good 1,71 126 108

A4 good 1,64 133 107

A5 good 1,69 157 113

A6 moderate 1,83 137 111

A7 good 1,81 135 146

A8 84

A9 120

A10 149

Bl good 1,94 126 107

B2 good 149

B3 good 1,65 111 151

B4 good 1,84 110 154

B5 good 1,68 127 162

B6 good 1,8 114 160

B7 good 1,88 129 169

B8 good 140

B9 92

BIO 117

Bll 132

B12 149

B13 156

B14 176

From this table follows that a whole series of copolyamides can be used for the preparation of dyeable compositions according to the invention, if these copolyamides contain sufficiently long aliphatic carbon chains.

The copolyamides show a sufficient compatibility with the used polypropylene, such that fibres can be spun from a composition according to the invention.

Polypropylene compositions containing copolyamides with the general structure PA6/ PA66/PA12 x/y/z have a good processability and a good dyeability, upon which the molecular weight and the molecular weight distribution and the relative viscosity n rel of the copolyamides have only a limited influence. Polypropylene compositions with a copolyamide containing piperazine are good to process and very good dyeable.

The influence of the copolyamide and EVA components upon the physical features of fibres, manufactured from compositions according to the invention, are limited. If necessary, the extension at rupture can be adapted to the necessities of specific applications by adapting the working conditions during the extrusion, such as the extension factor and the temperature.

The addition of an EVA component renders a considerable enhancement of the processability and dyeability of the compositions, whereas the physical features are not influenced considerably.

Furthermore, in order to illustrate the invention, examples are given hereafter on a semi-industrial and industrial scale.

Extrusion of Bulked Continuous Filament (BCF) yarns.

The composition of example B.2, containing 92 % PP, 3 % copolyamide, and 5 % EVA, was tested on semi-industrial scale. The copolyamide and EVA components were mixed, after previous drying, with polypropylene, and subse¬ quently the formulation was further homogenized in a mixer with a mixing screw (Axon laboratorium compounder) as described here above.

The dried composition then was extruded to BCF carpet yarn by means of a Thermoalfa pilot extrusion line. The extrusion was performed under conditions which are identical with the conditions for the normal extrusion of polypropylene with an MFI of 12 to yarn. In this example, the mixture was extruded at 230°C through a spinning plate with 120 trilobal openings.

The obtained fibres were cooled in a cooling hood by means of cold air. Then, approximately 0,7 % of spinning oil were applied thereto and the fibre was received on a roll, heated up to 100°C, at a rotation speed of 350 m/min.

The yarn was extended in two steps, using rolls which were heated up to 130°C and rotating with a speed of 700 and 1050 meters per minute respectively, whereby an extension of a factor 3 was obtained. The yarn was texturized by means of a hot airstream, cooled down on a cooled cylinder, tangled by air and finally wound up at 950 m/min. The obtained yarn is classical BCF carpet yarn with 120 trilobal filaments and a total of 1800 denier.

A dye bath was prepared, consisting of 100 ml water, acidified with ethanoic acid to a pH value of 5, and 1

g/1 dispersion agent. A quantity of 5 g of the obtained BCF yarn was brought into the bath which was heated up to 70 "c and to which 0,05 g colouring agent (Dispersol Blue BN 150 [Cl Disperse Bleu 56]), were added. The bath was heated further with a speed of 2 °C/minute to loo °C. The bath was kept 30 minutes at this temperature and then cooled down in 10 minutes to 70 °C. The dye bath was removed, and after rinsing and a reductive post-treatment with a solution of 2 g/1 hydrosulphite (Na ₂ S ₂ 0 ₄ ), the fibres were dried.

The dyed yarns were measured by means of CMS, and the obtained values are L*: 48,13; a*: -3,86 b*: -35,22.

The dye exhaustion was calculated by means of measurements in UV and visible light and, in this example, had a value of 85%.

Extrusion of a flat continuous filament yarn (CF yarn)

A composition, consisting of:

92% polypropylene with a MFI value of 25 and an isotacticity of 94% (commercial quality) 3% copolyamide (PA 6/PA 66/PA12 of 40/20/40%) 5% EVA (28% vinyl acetate units) was extruded to CF yarn by means of a Thermoalfa extrusion line. The components were dried beforehand and then added to the polypropylene and mixed for the extrusion which was performed at 230^ through a head with 72 openings. The obtained fibres were cooled by means of cold air, were provided with spinning oil (approximately 1%), and wound upon a roll heated up to 110°C and with a rotation speed of 550 m/min. The yarn was extended in two steps by means of rolls heated up to 150°C and rotating with a speed of 1100 and 1650 m/min

respectively, which resulted in an extension with a factor 3, and then was wound on spools. The obtained yarn with a denier of 800 can be used in the fabrication of woven textiles for furniture upholstery.

A dye bath was prepared, consisting of 100 ml water, acidified with ethanoic acid to a pH value of 5, and 10 g of the obtained fibres were brought into it. The bath was heated up to 70 °C, and 0,05 g colouring agent, namely Cetylon Ecarlate B 166% (Cl Disperse Red 1), was added. The bath was heated further with a speed of l "c/minute to 120 °C. The bath was kept 15 minutes at this temperature and then cooled down in 15 minutes to 70 °C. The dye bath was removed, the yarn was rinsed, and an post-treatment with a solution of 2 g/1 hydrosulphite was performed.

The dyed yarns were measured by means of CMS, and the following values were obtained:

L*: 47,38; a*: 41,89 b*: 32,80.

A knitted product, fabricated with the aforementioned CF yarn, was printed with a printing paste consisting of: a solution of 50 g/kg of a natural thickener (Solvitose) in hot water, acidified with 2 g/kg citric acid, and

30 g/kg dispersion colouring agent. The material was printed using a flat screen on a Zimmer table, and the fixation of the print was performed at 120 ^° C. Subsequently, the printed material was rinsed with cold water and a soap solution at 50°C.

This knitted product was good printable.

Extrusion of texturized staple fibres on industrial scale.

A composition, consisting of:

92% polypropylene with a MFI value of 18, 3% copolyamide (PA 6/PA 66/PA 12 40/20/40%) 5% EVA (28% vinyl acetate units) was extruded by means of a Neumag extrusion line to staple fibers suitable for processing to carpets.

After previous drying, the components were added to the polypropylene and the whole was mixed before being extruded. The mixture was extruded at 230°C, and the obtained fibres were cooled down with cold air. The fibres were treated with 1% of spinning oil and wound onto a cold rotating roll at a speed of 450 m/min. The yarn was extended in two steps, such that a total extension with a factor 3 was obtained. The yarn was texturized by means of a hot airstream, stabilized and cut to fibres with a length of 15 cm.

The dyeability was examined by means of the above described standard method.

These staple fibres can be processed further by means of spinning to yarns for the production of tufted or woven carpets.

The invention is in no way limited to the above described polypropylene compositions and products manufactured therewith, on the contrary may such compositions and products be realized in different variations without leaving the scope of the invention.