WO1998042898A1

WO1998042898A1 - Use of amphiphiles for hydrophilic treatment of polyolefin-based shaped bodies, fibers and films

Info

Publication number: WO1998042898A1
Application number: PCT/EP1998/001505
Authority: WO
Inventors: Norbert Bialas; Paul Birnbrich; Herbert Fischer; Jörg-Dieter KLAMANN; Raymond Mathis
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1997-03-25
Filing date: 1998-03-16
Publication date: 1998-10-01
Also published as: DE19712379A1

Abstract

The invention relates to the use of amphiphiles for permanent hydrophilic treatment of surfaces of polyolefin-based shaped bodies, fibers and films involving the treatment of a mixture containing a) a predominant amount of one or several polyolefins, b) 0.01-10 wt.% - in relation to the polyolefins - of one or several migratable amphiphiles (additive I) and c) between 0.01-1,000 ppm of one or several transition metal compounds (II) - metal content of transition metal compounds (II) in relation to the polyolefins - , wherein said mixture is subjected as is usual to temperatures ranging from 180 to 320 °C for form processing such as extrusion, calendering, injection molding and the like.

Description

Use of amphiphiles for the hydrophilization of polyolefin-based moldings, fibers and films

Field of the Invention

The invention relates to the use of amphiphiles for the permanent hydrophilization of the surfaces of polyolefin-based moldings, fibers and films.

State of the art

In numerous cases, the surface of plastic products must be provided with special effects that can either not be created at all or only incompletely for technical reasons, or can only be produced disadvantageously for economic reasons. Such effects are, for example, the improvement of the wettability with polar liquids such as water - technical applications here are, for example, in the field of the manufacture of hygiene articles or geoswoven fabrics - or the improvement of the antistatic properties.

In the manufacture of hygiene articles, such as diapers or sanitary napkins, absorbent materials are used to absorb aqueous liquids. To prevent direct contact with the absorbent material when worn and to increase comfort, this material is covered with a thin, water-permeable nonwoven. Such nonwovens are usually made from synthetic fibers, such as polyolefin or polyester fibers, since these fibers are inexpensive to produce, have good mechanical properties and are thermally resilient. However, untreated polyolefin or polyester fibers are not suitable for this purpose because their hydrophobic surface means that they are not sufficiently permeable to aqueous liquids.

For this purpose, the fiber surface must be made hydrophilic by an appropriate preparation. It is also desirable that the hydrophilic finish of the fiber is preserved as long as possible without the water permeability of the nonwoven being reduced. If such nonwovens are processed, for example, in diapers, they can be used several times without becoming leaky. In this way, the wearing time of the diapers is increased and the waste caused by used diapers is reduced.

The specialist understands geovlies to be special covers - mostly based on polyolefin-based fabrics - which are intended to protect soil such as arable land or cultivated land or tailings piles against mechanical stress such as wind erosion or treading by humans and animals and / or thermal loads such as heat or frost. However, it may also be desirable to ensure that the floor coverings, which are usually applied in the form of thin foils, are sufficiently permeable to air humidity and rain in order to provide a desired microclimate in the sense of growth-promoting climatic conditions.

For example, US Pat. No. 5,045,387 describes an agent for the hydrophilic finishing of polyolefin fibers which is a mixture of an alkoxylated ricinoleic acid derivative, a hydrogenated ricinoleic acid derivative, a cig fatty acid and one contains polyalkoxylated polymethylsiloxane. This agent must be applied from the outside to the surface of the fibers or films.

The state of the art is to improve the properties of the plastic surface in order to achieve special effects by, for example, oxidative aftertreatment methods such as corona or plasma treatment. Here, the plastic is oxidized or chemically modified in the presence of gases and discharges on the surface, which means that certain surface properties of the plastic can be modified. However, these methods always require an additional operation in addition to high energy consumption and lead to ozone emissions in the manufacture of plastic parts.

In addition, chemical pretreatment processes such as the treatment with fluorine or chlorine gas, with chromosulfuric acid or fluorosulfonic acid, etc. has been known for a long time.

EP-B-372 890 describes fibers based on polyolefm or polyester with a lubricant adhered to the surface. This lubricant comprises a mixture of (1) fatty acid diethanolamide, (2) a polyether-modified silicone, (3) a sorbitan fatty acid ester and (4) a metal salt of an alkyl sulfonate; Components (1) to (4) are available in special proportions. According to page 3, lines 20-26, the mixture of components (1) to (4) is applied to the surface. This technique of applying the mixture containing the four components to the surface of finished fibers is also explained in more detail on page 4, lines 6-9. There are listed as application techniques: a) the use of rollers, b) spraying and c) immersion. It is therefore a process in which a mixture of components (1) to (4) is applied to the surface of molded polyolefin parts in an additional processing step. The expression "adhered to the fiber surface" used in claim 1 of EP-B-372 890 is accordingly to be clearly understood by a person skilled in the art in such a way that this is merely a loose and temporary adhesion - for example due to relatively weak adhesive forces - but in no way a permanent anchoring.

With regard to the very widespread classic chemical aftertreatment processes such as corona and plasma treatment, the person skilled in the art is aware that no precise statements can be made about the process processes taking place. However, it has been proven that there are oxidative changes in the surface and certain "active centers" are formed. However, their concentration usually decreases over time, so that the pretreatment effect only lasts for a certain period, usually not over 72 hours (see, for example: Klaus Stoeckert (editor), "Finishing plastic surfaces", Munich 1974, page 137).

All of the methods known from the prior art have in common that the desired surface effects are generally only temporary.

EP-B-616 622 relates to extrudable, compostable polymer compositions comprising an extrudable, thermoplastic polymer, copolymer or mixtures thereof which contains a degradation-promoting system composed of an autooxidative component and a transition metal. The autooxidative system comprises a fatty acid, a substituted fatty acid or derivatives or mixtures thereof, the fatty acid having 10 to 22 carbon atoms and containing at least 0.1% by weight of unsaturated compounds and at least 0.1% by weight of free acid . The transition metal is contained in the composition in an amount of 5-500 ppm in the form of a salt and selected from the group cobalt, manganese, copper, cerium, vanadium and iron. The composition should be in the form of a film about 100 microns thick at 60 ° C and a relative humidity of at least 80% biodegradable within 14 days for embrittlement. Description of the invention

The object of the present invention was to provide tools with which a permanent and effective hydrophilization of the surfaces of polyolefin-based moldings, fibers and films can be achieved. In particular, this was intended to achieve a lasting improvement in the surfaces of polyolefin-based moldings, fibers and films with regard to their wettability with respect to polar liquids such as water and with regard to their antistatic properties.

The term “hydrophilization” - more recently, one often speaks of “hydrophilization” - is well known to the person skilled in the art. For this purpose, in the well-known standard work "Lexikon für Textilveredlung" (publisher: Hans-Karl Rouette; Volume 1; Dülmen 1995, pages 859-862) it is stated that hydrophobic fibers are made wettable by water by hydrophilization, which for example improves the washability of Synthetic fiber articles as well as for a better wearing comfort of such articles makes sense; further advantages of the hydrophilization are mentioned the reduction of the dirtiness and the electrostatic charge. Examples of measurement-technical indicators of a successful hydrophilization are the wetting (the surface spread of a liquid), the rise (a Measure of the speed at which water is transported against the force of gravity in textile fabrics, the determination of the static charge and discharge. In the context of the present invention, fabrics are understood to be flat structures, the uniform shaped bodies or foils represent or in which the flatness is achieved in that they are made up of fibers. In the context of the present invention, hydrophilization is understood to mean that polyolefin surfaces which form a wetting angle of more than 90 ° with water - that is to say “hydrophobic” interfaces - are modified by a special measure in such a way that their critical angle becomes smaller after this measure Examples of this are given in the example section of the present application The outstanding positive properties of hydrophilized surfaces, namely an improvement in the wettability against polar liquids such as water and / or a reduction in electrostatic charge are expressly included in the scope of the present invention These are rather dynamic interactions of appropriately modified polyolefin surfaces with molecules or substrates that are not immobilized but are in flexible contact with the polyolefin surface Effects that fall under the concept of hydrophilization expressly depend on phenomena in which molecules or substrates are in permanent fixation in contact with the polyolefin surface, as is the case with coatings and bonds or with dyeing and printing.

The present invention relates to the use of amphiphiles for the permanent hydrophilization of the surfaces of polyolefin-based moldings, fibers and films, with a mixture containing

a) predominantly one or more polyolefins,

b) 0.01 to 10 wt .-% - based on the polyolefins - one or more migratable amphiphiles (additives I) and

c) 0.01 to 1000 ppm of one or more transition metal compounds (II) - metal content of the transition metal compounds (II) based on the polyolefins - at temperatures in the range of 180 to 320 ° C in a conventional manner, a shaping processing such as extrusion, calendering, injection molding and the like.

The additives according to the invention are also called additives (I) below. These are compounds of an amphiphilic nature. An amphiphilic is understood here - in line with common usage - to mean a compound that combines hydrophobic and hydrophilic parts of the molecule. In other words, in the molecular structure of the amphiphiles there is a "combination" of a suitably designed oleophilic basic molecule based on hydrocarbons, which has one or more substituents with increased polarity. Such substituents with increased polarity are formed in a known manner by molecular components containing heteroatoms, where the heteroatoms oxygen, nitrogen and / or halogen are of particular importance for the formation of the functional group (s) of increased polarity.

The use of the amphiphiles according to the invention ensures that the surfaces of polyolefin-based moldings, fibers and films are permanently hydrophilized and without additional pretreatment, so that, for example, improved wettability with polar liquids such as water and / or improved antistatic properties result. Once set, the hydrophilicity values are retained over long periods or even increase with further storage.

The mixture containing components a), b) and c) is used by customary shaping processing techniques, such as extrusion, calendering, injection molding and the like, which are well known to those skilled in the art. It is preferred in the context of the teaching of the present inventions if, in the course of the shaping processing, the melt of the mixture comprising components a), b) and c) comes into contact with oxygen - in particular atmospheric oxygen is coming. This is the case, for example, in the case of extrusion when the melt leaves the extruder through the outlet nozzle. The preferred embodiment mentioned enables - optionally catalytically supported - oxidative processes, for example an oxidatively induced crosslinking - and thus ultimately immobilization - of olefinically unsaturated molecular constituents of the additives (I) with the formation of higher molecular weight compounds, an oxidatively induced oxidation of activated methylene groups which occur in the immediate vicinity Neighboring to the polar groups of the amphiphiles (I), as well as further oxidative reactions and secondary reactions can take place. (Air) oxygen can act on the surface itself, on the one hand, and also inside the plastic - especially in areas close to the surface - where it can get through diffusion.

The additives (I) which are suitable in the context of the teaching of the present invention have relatively low molecular weights - a prerequisite for an appropriately rapid migration. An upper limit for the molecular weight of suitable internal additives (I) is approximately 5,000 D (Dalton), preferably a maximum value of approximately 3,000 D and in particular a maximum value of approximately 1,000 D. As is known, the molecular weight specification in "Dalton" is the definition of the absolute molecular weight . Compared to the polyolefins with their molecular weights in the millions, there are therefore comparatively low molecular weight compounds. The lower limits for the molecular weight of these internal additives (I) are approximately 50 to 100 D, preferably 150 to 180 D and in particular approximately 200 to 300 D.

The additives (I) preferred according to the invention are those amphiphiles whose hydrophobic molecular parts at least partially contain olefinically unsaturated functions which are particularly easily accessible to free-radically induced crosslinking reactions in the region of the plastic surface. Such ad additives (I) which, in the unreacted state, have iodine numbers of at least about 10, preferably of at least about 30 to 40 and in particular of at least about 45 to 50. The choice of the method for determining the iodine number is of minor importance. For the purposes of the present invention, however, express reference is made to the methods according to Hanus or Wijs, which have long been part of the CV section of the "DGF standard methods", and to the equivalent method according to Fiebig (cf. Fat Sei. Technol. 1991 , No. 1, pages 13-19).

As will be shown in more detail, both monoolefinically unsaturated hydrocarbon radicals and polyolefinically unsaturated hydrocarbon radicals can be provided in the context of the additives (I) used according to the invention. Combinations of a plurality of corresponding compounds are also important auxiliary substances for the action according to the invention. The respective iodine numbers of the additives (I) used can assume values above 80 to 90 and in particular also values above 100. Highly unsaturated additive components with iodine numbers of up to about 200 or even more, for example in the range from 120 to 170, are auxiliary substances in the sense of the action according to the invention.

In the spatial structure of their hydrocarbon radical, these internal additives (I) can be both straight-chain and branched and / or have a cyclic structure.

Substituents of increased polarity are in principle those functional groups which are distinguished in particular by a content of heteroatoms and in turn preferably by a content of O, N and / or halogen. The term functional group is used in the context of the present invention in its most general sense; atomic groupings are understood here, each of which has a characteristic reactivity have and which contain one or more heteroatoms. Accordingly, this definition includes OH groups (simple atomic groups) or N-containing heterocycles (more complex atomic groups), but not C = C double bonds (no heteroatoms) per se, unless they are included in more complex atomic groups in addition to the heteroatoms . Residues from the classes carboxyl, hydroxyl, amino, oxazoline, imidazoline, epoxy and / or isocyanate and / or derivatives derived therefrom may be mentioned here merely by way of example. The group of such derivatives includes, for example, ester groups, ether groups, amide groups / alkanolamine and / or alkanolamide groups.

A very important class of substituents of increased polarity in the context of the present invention are N-containing heterocycles and / or their derivatives. Examples of these are pyridazine, pyrimidine, pyrazine, pyridine, azane and azinane groups; thiazole, thiazolane, thiazolidine, pyrrole, azolane, azolidine, pyrazole and isooxazole groups are particularly suitable imidazole, imidazoline, diazolidine, oxazoline, oxazole, oxazolidine and oxazolidane groups are particularly suitable.

A particularly preferred class of additives (I) are compounds which on the one hand have one or more olefinically unsaturated functions in the hydrophobic part of the molecule and on the other hand extremely polar functions such as oxazoline, imidazoline, sulfonate, phosphonate or carboxyl groups (or their salts) contain hydrophilic part of the molecule.

Individually selected specific additives of the type shown here, but also mixtures of a plurality of corresponding auxiliaries, can be used as additive (I). By suitable selection of the substituents with Increased polarity of the additives of this class of additives added in each case can be influenced in a predeterminable manner the hydrophilicity properties which can be set on the finished product. However, mixtures of valuable substances of the type concerned here are also corresponding mixtures of substances which can be assigned to a specific subclass in terms of their functional group - for example have carboxyl groups as substituents of increased polarity - but have different basic structures in their hydrocarbon molecule. Corresponding mixtures of substances are known to occur particularly when mixtures of the type concerned here are used based on natural substances. For example, olefinically unsaturated fatty acid mixtures of vegetable and / or animal origin or derivatives derived therefrom can be valuable additives of the type of additives (I) in the sense of the teaching according to the invention.

In a manner known per se to the person skilled in the art, depending on the groups of increased polarity specified here, different improvements in the hydrophilicity properties can be expected. In this respect, reference can be made to the relevant specialist knowledge.

Another possible variation in the design of the internal additives (I) according to the invention lies in the number of functional substituents of increased polarity on the respective hydrocarbon backbone. Even a substituent of increased polarity - especially after coordinating the type and amount of functional groups provided - can lead to the desired permanent and at the same time intensive increase in the hydrophilicity properties. However, it has also been found that the presence of two or more such substituents of increased polarity in the respective molecule of the additive (I) can be an important additional feature for increasing the hydrophilicity properties. For example, reference is made here to the class of the so-called dimer fatty acids. Dimer fatty acids are - as is common in the art - to be understood as those carboxylic acids which are accessible by oligomerizing unsaturated carboxylic acids, generally fatty acids such as oleic acid, linoleic acid, erucic acid and the like. The oligomerization is usually carried out at elevated temperature in the presence of a catalyst made of, for example, alumina. The products obtained are mixtures of different substances, with the dimersization products predominating. However, small proportions of higher oligomers, in particular the trimer fatty acids, are also present. In addition, the dimer fatty acids also contain monomers or monofunctional fatty acids due to their production. Dimer fatty acids are commercially available products and are offered in various compositions and qualities. Analogously to the dimer fatty acids, the trimer fatty acids are oligomerization products of unsaturated fatty acids, but the proportion of trimers in the product predominates. Dimer and trimer fatty acids have olefinic double bonds which enable them to be solidified in the area of the polyolefin surface.

Dialkanolamines with at least partially olefinically unsaturated hydrocarbon radicals or dialkanolamides of unsaturated fatty acids are highly effective in terms of improving the hydrophilicity properties in the sense of the teaching according to the invention. This applies in particular to the corresponding diethanol derivatives. This class includes, for example, oleic acid diethanolamide and linoleic acid diethanolamide. Technical products known to the person skilled in the art, including the secondary components usually occurring therein, are expressly included in this connection. Examples of this are "Comperlan OD" (technical oleic acid dhanolamide) and "Comperlan F" (technical linoleic acid diethanolamide), both known commercial products from the applicant. But also compounds of the type of sorbitan monoesters with in particular ethylenic Unsaturated fatty acids lead to optimized results in the sense of the action according to the invention.

The migration rate to be expected on the basis of the molecular structure of the additives (I) used in each case can be one of the factors which also determine the amount of these additives (I) to be used in the individual case. Lower limits for the amount of these additives of the additive (I) to the polyolefin are about 0.01% by weight and in particular about 0.1% by weight. As a rule, it will be expedient to use at least about 0.2 to 0.8% by weight -% by weight, in each case based on the polyolefins. Optimized hydrophilicity property values for the representatives of this substance class for the additive (I) used in each individual case are generally in the range from about 0.3 to 5% by weight and in particular in the range from 0.4 to about 1% by weight. -% set.

As already mentioned, the optimal surface hydrophilicity to be set is understandably determined by the chemical nature and the possible interaction of the substituents of increased polarity and, if appropriate, reactivity on the additive (I).

As already mentioned, the additives (I) are used in the shaping processing of the polyolefins in combination with transition metal compounds (II). The amount of the transition metal compound (II) - metal content of the transition metal compound (II) based on the polyolefins - 0.01 to 1000 ppm. With regard to the type of transition metal compounds (II), there is no particular restriction per se. Accordingly, in principle all transition metal compounds known to the person skilled in the art can be used in the context of the teaching of the present invention. In one embodiment, transition metal salts, preferably salts based on organic acids having 8 to 22 carbon atoms, are used as transition metal compounds (II). In a further embodiment, the transition metals are selected from the group lead, nickel, zirconium con, chrome, titanium and tin. In a further embodiment, the transition metal compounds are used in an amount which is below 5 ppm, the metal content of the transition metal compound (II), based on the polyolefins. In this case, cobalt, copper, iron, vanadium, cerium and manganese can also be used instead of or in addition to the metals just mentioned.

If desired, in addition to the obligatory transition metal compounds (II) mentioned, other compounds are used which are known to the person skilled in the art as catalysts for oxidative processes.

In a preferred embodiment, the weight ratio of the additives (I) to the metal content of the transition metal compounds (II) is set in the range from 10: 0.1 and 10: 10 " ^7. A range from 10: 0.02 and is preferred 10: 10 " ⁶ and in particular 10: 0.01 and 10: 10" ⁵ .

With regard to the teaching of the EP-B-616 622 dealt with at the beginning, the following applies:

The technical action within the meaning of the teaching according to the invention ensures on the one hand that the desired improved and permanent surface hydrophilicity is achieved, and on the other hand that this can be achieved without impairing other material parameters.

In a preferred embodiment, the transition metal compounds (II) are used in combination with such additives (I) which are selected from the class of the diefhanolamides of unsaturated fatty acids. As already stated, the diethanolamides are preferably used as technical goods.

The amphiphilic additives (I) are used according to the invention in the course of customary shaping processing processes such as extrusion, ca Landing, injection molding and the like. It may be desirable to use a pre-assembled mixture of components a), b) and c). Other customary auxiliaries which have been used and which have generally proven themselves in the processing of plastics and which are known to the person skilled in the art, for example slip agents, antistatic agents, lubricants, mold release agents, UV stabilizers, antioxidants, fillers, fire retardants, mold release agents, nucleating agents and anti-blocking agents can be used accordingly pre-assembled in separate form and added during the final mixing of the finished products. However, it may also be desirable, for example when using the extrusion technology, to meter all or part of the components b) and / or c) and / or other additives directly into the polyolefin melt on the extruder, so that the mixture of components a), b) and c) - and possibly other auxiliaries - is not already present as a ready-made product from the outset, but is only present in the extruder itself. Such a technique is useful, for example, when the additives (I) to be added to the polymer melt are in liquid form and injection of this component is easier than pre-assembly.

It may also be desirable - although not necessary to achieve the effect according to the invention - to carry out a corona or plasma treatment in the usual way after the use of components a) - c) according to the invention.

As an oleophilic polyolefin base material, all known polymer and copolymer types based on ethylene or propylene are suitable per se.

Mixtures of pure polyolefins with copolymers are also fundamentally suitable, as long as the migratability of the additives (I) is maintained in the sense of the invention and thus their enrichment in the area of the solid surfaces is ensured. Polymer types which are particularly suitable for the teaching according to the invention are listed in the following compilation: Poly (ethylene) such as HDPE (high density polyethylene), LDPE (low density polyethylene), VLDPE (very low density polyethylene), LLDPE (linear low density polyethylene), MDPE (medium density polyethylene), UHMPE (ultra high molecular polyethylene), VPE (cross-linked polyethylene), HPPE (high pressure polyethylene); isotactic polypropylene; syndiotactic polypropylene; Metallocene catalyzed polypropylene, impact modified polypropylene, random copolymers based on ethylene and propylene, block copolymers based on ethylene and propylene; EPM (poly [ethylene-co-propylene]); EPDM (Poly [ethylene-co-propylene-co-conjugated diene]).

Other suitable types of polymer are: Poιy (styrene); Poly (methyl styrene); Poly (oxymethylene); Metallocene-catalyzed alpha-olefin or cycloolefin copolymers such as norbornene-ethylene copolymers; Copolymers containing at least 80% ethylene and / or styrene and less than 20% monomers such as vinyl acetate, acrylic acid ester, methacrylic acid ester, acrylic acid, acrylonitrile, vinyl chloride. Examples of such polymers are: poly (ethylene-co-ethyl acrylate), poly (ethylene-co-vinyl acetate), poly (ethylene-co-vinyl chloride), poly (styrene-co-acrylonitrile). Graft copolymers and polymer blends, that is to say mixtures of polymers which contain, inter alia, the abovementioned polymers, for example polymer blends based on polyethylene and polypropylene, are also suitable.

Within the scope of the present invention, homopolymers and copolymers based on ethylene and propylene are particularly preferred. In one embodiment of the present invention, accordingly, only polyethylene is used as the polyolefin, in another embodiment only polypropylene, in another embodiment, copolymers based on ethylene and propylene. Another object of the invention is a process for the permanent improvement of the surface hydrophilicity of polyolefin-based moldings, fibers and films, wherein one containing a mixture

a) predominantly one or more polyolefins,

c) 0.01 to 1000 ppm of one or more transition metal compounds (II) - metal content of the transition metal compounds (II) based on the polyolefins -

at temperatures in the range of 180 to 320 ° C in a conventional manner, a shaping processing such as extrusion, calendering, injection molding and the like.

As already mentioned, the outstanding effects of surface hydrophilicity are above all the improved wettability against polar liquids such as water and / or improved antistatic properties.

Another object of the invention is the use of polyolefin-based moldings, fibers and films with permanently improved surface hydrophilicity, which can be obtained by the above-mentioned method according to the invention, for the production of textile fabrics. Non-woven fabrics - such as those used in the area of hygiene articles - and geoylites - such as those used in the area of ground coverings are preferred. General requirement profiles for nonwovens and geovlies have already been described above. They are fulfilled in an excellent manner by the use according to the invention mentioned here. The following examples serve to illustrate the invention and are not to be understood as restrictive.

B e i s p i e l e

1. Materials used:

1.1. Polyolefins

PE: high molecular weight polyethylene granulate (commercial product "Lupolen 1800 H" from BASF AG)

PP: high-molecular polyolefin, a polypropylene granulate commercial product "Hostalen PPH 2150" from Hoechst AG)

1.2. Additives (I)

Ricinic acid: (commercial product "Edenor Ri 90" from Henkel KGaA)

Comperlan F: linoleic acid diethanolamide, technical quality (commercial product "Comperlan F" from Henkel KGaA, Düsseldorf)

1.3. Transition metal compounds (II)

Pb-C8: lead 2-ethylhexanoate (lead salt of 2-ethylhexanoic acid)

Ni-acac: nickel acetylacetonate

Co / Zr / Pb-lig: mixture of a cobalt, zirconium and lead 2-ethylhexanoate (contains 1.04% by weight of Co; 2.48% by weight of Zr; 9.93% by weight of Pb ) 2. Production of surface-modified polyolefins

according to the method of the invention

To check the hydrophilicity properties of surface-modified polyolefins according to the invention, polyethylene or polypropylene tapes were first produced. To do this, each

- 600 g of polyethylene or polypropylene granules with

- 9.0 g (= 1.5%) additive (I) and

- 0.38 g transition metal compound (II)

blended. The additives (I) and transition metal compounds (II) used in each case can be found in the data in Tables 1 to 3. These mixtures were fed into an extruder through a hopper. A twin screw extruder DSK 42/7 from Brabender OHG (Duisburg) was used.

An extruder is - as is well known to the person skilled in the art - a plastic processing machine which is suitable for the continuous mixing and plasticizing of both powder and granular thermoplastics.

In addition to water cooling, which is intended to prevent premature melting of the granules or powder, there is also a counter-rotating twin screw, which is divided lengthways into three heating zones. The temperature of the heating zones and the speed of the twin screw can be controlled via a PL 2000 data processing plast corder, which is connected to the extruder via a PC interface. The following temperatures were set for the production of the polyolefin tapes: heating zone I: 250 ° C., heating zone II: 270 ° C., heating zone III: 290 ° C., the three heating zones being air-cooled in order to keep the temperatures constant.

The polyolefin granules (including the respective additive (I) and the transition metal compound II) were automatically drawn into the extruder by the twin screw running counter to one another and conveyed along the screw. The speed was 25 revolutions per minute. This ensured a relatively long residence time in the extruder and, accordingly, good mixing and homogenization. This homogeneous and practically bubble-free mixture finally came into a nozzle, which is a fourth heating zone. The temperature of the nozzle was 300 ° C - at this temperature the mixture left the extruder.

After exiting the nozzle, the hot mixture flowed onto a conveyor belt, the speed of which was adjusted in such a way that a smooth and uniformly thick and wide belt was formed when cooling in air. In the work described here, the speed was set so that the polyolefin tape was about 35 mm wide and about 0.35 mm thick. Square test specimens were punched out of this material and used for the experiments described in more detail below.

For comparison purposes, test specimens made of pure polyethylene or polypropylene were used. The production was carried out using the extrusion technique just described, but only polyethylene or polypropylene granules were used without the addition of additive (I) and transition metal compound (II). The test results based on this material are identified in Table 1 in the first column in each case by the indication "compare". 3. Determination of the hydrophilicity properties

Untreated and surface-modified polypropylene test specimens according to the present invention were first stored for 7 days at 60 ° C. and then the wetting tension and the contact angle against water were determined at 25 ° C. using a Kl 4 tensiometer from Krüss. The corresponding polyethylene test specimens were examined immediately after manufacture, ie without storage.

The test results are summarized in Table 1. All results are averages from five experiments each. The wetting tension is given in the dimension mN / m, the contact angle in the dimension °.

Table 1: Wetting voltages (BSp) and contact angle (KWi)

Claims

Patent claims

1. Use of amphiphiles for the permanent hydrophilization of the surfaces of polyolefin-based moldings, fibers and films, with a mixture containing

a) predominantly one or more polyolefins,

2. Use according to claim 1, wherein such additives (I) are used which have molecular weights in the range from 50 to 3000 D.

3. Use according to claim 1 or 2, wherein such additives (I) are used which have iodine numbers in the range from 10 to 200.

4. Use according to one of claims 1 to 3, wherein such additives (I) are used which, as substituents of increased polarity, residues from the classes carboxyl, hydroxyl, amino, oxazoline, imidazoline, epoxy and / or isocyanate and / or residues of derivatives derived therefrom, in particular ester, ether, amide, alkanolamine and / or alkanolamide groups.

5. Use according to one of claims 1 to 4, wherein the transition metal compounds (II) are selected from the group of transition metal salts.

6. Use according to any one of claims 1 to 5, wherein the transition metal compounds (II) are used in an amount which is below 5 ppm - metal content of the transition metal compounds (II) based on the polyolefins.

7. Use according to one of claims 1 to 6, wherein such transition metal compounds (II) are used in which the transition metal is selected from the group lead, nickel, zirconium, chromium, titanium and tin.

8. Use according to one of claims 1 to 7, wherein the weight ratio of the additives (I) to the metal content of the transition metal compounds (II) is set in the range from 10: 0.1 and 10: 10 ^{~ 7} .

9. Use according to one of claims 1 to 8, wherein the polyolefin used is exclusively polyethylene or polypropylene or an ethylene-propylene.

10. Use according to one of claims 1 to 9, wherein in the shaping processing of the polyolefins customary additional auxiliaries are added and / or as an additional further processing step in the usual way carries out a corona or plasma treatment.

11. Use for the permanent improvement of the surface hydrophilicity of polyolefin-based moldings, fibers and films, characterized in that containing a mixture

a) predominantly one or more polyolefins,

b) 0.01 to 10% by weight, based on the polyolefins, of one or more migratable amphiphiles (additives I) and c) 0.01 to 1000 ppm of one or more transition metal compounds (II) - metal content of the transition metal compounds (II) based on the polyolefins -

12. Use of polyolefin-based moldings, fibers and films with permanent improvement in surface hydrophilicity, which are obtainable by the process according to claim 11, for the production of textile fabrics.

13. Use according to claim 12, wherein the textile fabrics are nonwovens.

14. Use according to claim 12, wherein the textile fabrics are geovlies.