EP2396367A1

EP2396367A1 - Polymer compositions containing nanoparticulate ir absorbers

Info

Publication number: EP2396367A1
Application number: EP10702874A
Authority: EP
Inventors: Alban Glaser; Johannes LÖBEL
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2009-02-12
Filing date: 2010-02-08
Publication date: 2011-12-21
Also published as: US20120021152A1; BRPI1008338A2; KR20110128861A; CN102317355A; AU2010212940A1; JP2012517517A; MX2011007983A; WO2010092013A1; RU2011137186A

Abstract

The invention relates to methods for producing polymer compositions using preparations of nanoparticulate IR absorbers and to polymer compositions produced in such a way. The invention further relates to uses of said polymer compositions, for example, in heat management or in agriculture, in particular as greenhouse films. The invention further relates to molded bodies, in particular films containing such polymer compositions.

Description

Polymer compositions containing nanoparticulate IR absorbers

Description:

The present invention relates to processes for the preparation of polymer compositions by means of preparations of nanoparticulate IR absorbers and polymer compositions prepared in such a way. Uses of these polymer compositions, for example in thermal management or in agriculture, especially as greenhouse films, are also the subject of the invention. Another object of the invention are moldings, in particular films containing such polymer compositions.

Further embodiments of the present invention can be taken from the claims, the description and the examples. It is understood that the features mentioned above and those yet to be explained of the subject matter according to the invention can be used not only in the particular concretely specified combination but also in other combinations without departing from the scope of the invention. Preferred or very preferred are the embodiments of the present invention in which all features have the preferred or very preferred meanings.

EP 1 554 924 A1 describes materials for shielding thermal radiation in the field of agriculture or horticulture. The materials include a sheet consisting of a resin substrate and a filler of fine particles dispersed in the resin. The fine particles are, for example, lanthanum hexaboride or antimony-doped tin oxide.

EP 1 865 027 A1 describes polycarbonate compositions comprising metal boride fine particles. The moldings described in EP 1 865 027 A1 consisting of such polycarbonate compositions can be used as materials for windows and roofs or as films in agriculture.

GB 2 014 513 A describes transparent thermoplastic laminates which can be used as materials for greenhouses. The laminates contain at least two layers, with the lowermost layer having a high UV resistance and the other layers being impermeable to IR radiation. Allingham US 4,895,904 describes sheets or sheets of polymers and their use in greenhouses. Such plates or films contain finely divided components which absorb or reflect in the NIR range. These plates or foils are transparent to a proportion of at least 75% of the radiation relevant to photosynthesis. As finely divided components oxides or metals are used. Furthermore, in the plates or films UV stabilizers are included.

The excessive absorption of thermal radiation, in particular the thermal radiation of sunlight through the surface of, for example, buildings, vehicles, warehouses or greenhouses often leads to a significant increase in indoor temperatures, especially in areas with high solar radiation. In the case of greenhouses, this increase in the effect of heat has a negative effect on the yield of the plants grown in the greenhouse.

By shielding the heat radiation, however, often other areas of the solar spectrum should not be hidden as well. In particular, in the shielding of the heat radiation through greenhouse films, in addition to an effective shielding of the heat radiation, a high transparency is sought in the visible spectral range, in particular in the region of the visible spectrum, which is relevant for the photosynthesis processes of plants. Especially in these applications, therefore, only a slight turbidity of the materials is accepted by the heat protection, since even a slightly increased transparency usually leads to a significant increase in the yield.

The object of the present invention was therefore to provide a shield against heat radiation in the action of light, in particular of solar radiation on the surface of, for example, greenhouses and to ensure a high transparency to visible light with a simultaneous effective shielding of the heat radiation.

These and other objects have been achieved, as described below, by methods of making a polymer composition comprising the following steps a. Providing a polymer melt, b. Providing a preparation containing a liquid carrier medium and dispersed therein nanoparticulate IR absorbers, c. Mixing the polymer melt (a.) With the preparation (b.), D. Processing of the mixture (c).

Nanoparticulate IR absorbers in the context of the present application are particles having a weight-average particle diameter of generally at most 200 nm, preferably of at most 100 nm. A preferred particle size range is 4 to 100 nm, in particular 5 to 90 nm. Such particles are generally characterized high uniformity in size, size distribution and morphology. The particle size can be z. B. after the UPA method (Ultrafine Particle Analyzer) are determined, for. B. after the laser scattered light method (laser light back scattering).

In the IR range (about 700 to 12000 nm), preferably in the NIR range of 700 to 1500 nm, particularly preferably in the range of 900 to 1200, the nanoparticulate IR absorbers have a strong absorption. In the visible spectral range of about 400 nm to 760 nm, the nanoparticulate IR absorbers have only a weak absorption.

In general, a material is called transparent if you can see what is lying behind relatively clearly - for example, window glass. Transparency means as in the context of the present invention optical transparency substantially without scattering of the light through the transparent material in the visible spectral range.

To measure the haze, a haze meter, for example from Bykgardner, can be used. It consists of a tube placed in front of an integrating sphere. The measurement of the turbidity can be carried out according to ASTM D1003-7, as mentioned, for example, in EP 1 529 632 A1.

The temperature and pressure conditions under which the production process according to the invention is carried out are generally dependent on the polymers used and carrier media and can therefore vary over a wide range. In general, the provision of a polymer melt (a.) At temperatures of 100 to 300 ⁰ C, preferably from 100 to 250 ⁰ C is performed. In general, the provision of a preparation (b.) At temperatures from 0 to 150 ⁰ C, preferably from 10 to 120 ⁰ C. carried out. Mixing the polymer melt with the preparation in step c. is usually carried out at temperatures of 100 to 300 ⁰ C, preferably from 100 to 250 ⁰ C. The mixture is in step d. usually at temperatures of 100 to 300 ⁰ C, preferably from 100 to 250 ⁰ C carried out. All steps of the method according to the invention can be carried out at atmospheric pressure (1 atm.), But also at an overpressure of up to 100 bar or under a slight negative pressure.

Of course, one or more polymers, for example in the form of polymer blends or blends, can be used to provide the polymer melt (a.).

In a preferred embodiment of the process according to the invention, the polymers used to provide the polymer melt (a) are thermoplastic polymers.

Suitable thermoplastic polymers include oligomers, polymers, ionomers, dendrimers, copolymers, for example block copolymers, graft copolymers, star-shaped block copolymers, random block copolymers or mixtures of these. In general, the thermoplastic polymers have weight-average molecular weights Mw of 3,000 to 1,000,000 g / mol. Preferably, Mw is 10,000 to 100,000 g / mol, more preferably 20,000 to 50,000 g / mol, in particular 25,000 to 35,000 g / mol.

The thermoplastic polymers are primarily polyolefins, in particular polypropylenes and polyethylenes, polyolefin copolymers, in particular ethylvinylacetate copolymers, polytetrafluoroethylenes, ethylene-tetrafluoroethylene copolymers, polyvinylidene fluorides (PVDF), polyvinyl chlorides (PVC), polyvinylidene chlorides, polyvinyl alcohols, polyvinyl esters, polyvinylalkanals , Polyvinyl ketals, polyamides, polyimides, polycarbonates, polycarbonate blends, polyesters, polyester blends, poly (meth) acrylates, poly (meth) acrylate-styrene copolymer blends, poly (meth) acrylate-polyvinylidene difluoride

Blends, polyurethanes, polystyrenes, styrene copolymers, polyethers, polyether ketones, polysulfones and mixtures of these polymers. Polyethylene, PVC or PVDF are preferably used.

Polymer melts may be provided by any of the methods known to those skilled in the art, such as by melting polymers. The poly- mers may be present before melting in the form of powders and pellets. Preferably, the polymers are in the form of pellets. The melting preferably takes place in an extruder or calender.

The process according to the invention for the preparation of a polymer composition comprises, in step (b.), The provision of a liquid carrier medium having dispersed therein nanoparticulate IR absorbers. This means that the carrier medium is liquid at the respectively used pressure and temperature conditions in step (b.) And (c.). In the context of the present invention, a liquid carrier medium is understood as meaning a carrier medium having rheological properties which range from low viscosity via pasty / ointment-like to gelatinous. "Flowable compounds" typically have a higher viscosity than a liquid, but are not yet self-supporting, i. H. they do not maintain a form given to them without a shape-stabilizing covering. In the context of the present invention, the term liquid carrier medium should also include flowable components. The viscosity of such preparations is, for example, in a range of about 1 to 60,000 mPas.

An advantage of the use of liquid carrier media with dispersed nanoparticulate IR absorbers over the use of nanoparticulate IR absorbers in the solid state, for example as a powder, is that a generally more homogeneous distribution of the nanoparticulate IR absorbers in the polymer composition is achieved leaves without larger agglomerates occur. As a rule, larger agglomerates lead to undesired increased scattering of visible light, while a fine, homogeneous distribution of the nanoparticulate IR absorbers leads to improved absorption of IR radiation.

Suitable carrier media are, for example, many organic solvents which are liquid at room temperature and preferably do not react with oxygen. Preferably, these solvents have an approximately neutral pH.

Possible carrier media here are, for example:

Esters of alkyl and aryl carboxylic acids,

hydrogenated esters of arylcarboxylic acids with alkanols, monohydric or polyhydric alcohols,

Ether alcohols, Polyether polyols,

Ether,

saturated acyclic and cyclic hydrocarbons,

- mineral oils, - mineral oil derivatives,

- silicone oils,

aprotic polar solvents or mixtures of these carrier media. Preferred carrier media are ethylene glycol, glycerol, 1,3-propanediol, 1,4-butanediol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, acyclic or cyclic ethers, polyether polyols, low-boiling (boiling point less than 200 ^° C.) alcohols, in particular 1-butanol, 2-butanol or hydrocarbons having a boiling point less than 200 ⁰ C or mixtures of the said preferred carrier media used.

Furthermore come as a possible carrier media waxes in question. Preference can be used as carrier media polyolefin and Polyolefincomonomerwachse use, especially ethylene homopolymer waxes, montan waxes, oxidized and micronizing th PE waxes, metallocene PE waxes, ethylene copolymer waxes, for example products of Luwax ^® portfolio of the company. BASF SE.

Carrier media are generally available commercially.

In a preferred embodiment of the process according to the invention, the support medium is liquid under atmospheric pressure in a temperature range from 50 to 120 ^° C., preferably in a temperature range from 90 to 110 ^° C. In particular, the support medium is a PE wax.

According to the invention, the nanoparticulate IR absorbers are dispersed in the preparation from step (b.). This means that the nanoparticulate IR absorbers are present homogeneously and finely distributed in the carrier medium. Such a dispersion is achieved in that the nanoscale IR absorbers form substantially no aggregates or particles which are greater than 500 nm. Preferably, no aggregates or particles are larger than 300 nm, very preferably there are no aggregates or particles larger than 200 nm. In particular, there are separate particles with an average distance of at least 200 nm. In one embodiment of the composition of step (b.) Of the process according to the invention, more than 90% In a further preferred embodiment, more than 95% of the particles have an average particle size of less than 200 nm. In another embodiment, more than 99% of the particles have an average particle size of less than 200 In a further preferred embodiment, less than 10% of the particles, more preferably less than 5% of the particles have a smaller distance to the nearest particle of at least 50 nm, preferably at least 100 nm, more preferably at least 250 nm and in particular preferably at least 500 nm.

The particles can assume any shape. For example, spherical, rod-shaped, platelet-shaped particles or particles of irregular shape are possible. It is also possible to use nanoscale IR absorbers with bimodal or multimodal particle size distributions. The distribution of the particles can be checked, for example, with the aid of confocal laser scanning microscopy. The method is described, for example, in "Confocal and Two-Photon Microscopy," edited by Alberto Diaspro, ISBN 0-471-40920-0, Wiley-Liss, and John Wiley & Sons, Inc. Publicity, in Chapter 2, p It is also possible to determine the size of the ponds (distributions) using electron microscopy (TEM) methods.

As nanoparticulate IR absorbers which are present in the preparation in step (b.) Dispersed in the carrier medium, can be mentioned in the process of the invention, for example, Ruse, metal borides or doped tin oxides.

Nanoparticulate tin oxides doped with antimony (ATO) or indium (ITO) or nanoparticulate metal borides (MB _x , where x is from 1 to 6), in particular alkaline earth borides or borides of the rare earths, are preferably used as IR absorbers. Particular preference is given to nanoparticulate borides of the rare earths. Very particular preference is given to metal hexaborides of the symbolic formula MBε, in particular M = La, Pr, Nd, Ce, Tb, Dy, Ho, Y, Sm, Eu, Er, Tm, Yb, Lu, Sr, Ca. Metal borides MB2, in particular with M = Ti, Zr, Hf, V, Ta, Cr, Mo, are also preferred. Other suitable metal borides are M02B5, MoB, W2B5. A very excellent IR absorber is nanoparticulate lanthanum hexaboride (Laße). Of course, mixtures of the nanoparticulate substances mentioned are also suitable as IR absorbers. Nanoparticulate Laße is commercially available or can according to the methods of WO 2006/134141 or WO2007 / 107407 are produced. Nanoparticulate ITO or ATO is commercially available.

The amount of nanoparticulate IR absorber used can vary over a wide range and depends, for example, on the ultimate end use of the polymer composition. Decisive for an effective effect of the IR absorber is usually that when passing the heat radiation through the polymer composition enough IR absorber is present in the radiation path to absorb the heat radiation.

The amount of nanoparticulate IR absorber in the Polymerzusanmmensetzung is up to 2 wt .-% based on the thermoplastic polymer melt from step a. The amount of IR absorber is preferably 0.001 to 1 wt .-%, more preferably 0.01 to 0.5 wt .-% and in particular 0.01 to 0.2 wt .-%.

The proportion of IR radiation absorbed by the polymer composition will depend on the particular application desired. For example, the polymer composition absorbs more than 5% of the incident IR radiation. Preferably, more than 20%, more preferably more than 50% of the incident IR radiation is absorbed.

As a rule, the liquid carrier and the nanoparticulate IR absorbers are mixed with one another to provide the preparation in step (b.) Of the process according to the invention. The mixing can in principle be carried out using any mixing apparatus known to the person skilled in the art, such as, for example, stirrers, extruders and kneaders.

In a preferred embodiment of the method according to the invention for producing the polymer composition, the composition in step (b.) Containing metal borides is provided by means of in situ plasma synthesis, as described in the still unpublished EP 08167612.4. Here, a starting material for metal borides is provided, this starting material is subjected to a thermal treatment under plasma conditions, the product obtained is rapidly cooled and the resulting cooled product is introduced into a liquid to obtain a suspension which can be used as a preparation in step (b. ) of the method according to the invention can be used directly. The end- For example, starting material for borides of metal is provided by synthesis from suitable starting materials. The advantage of this method lies in the high purity of the preparations provided. In particular, in this case, for example, the grinding body abrasion occurring in the grinding process is avoided, which can lead to contamination of the preparation by foreign substances and later to turbidity of the polymer composition.

In another embodiment, the preparation of the preparation from step (b.) Is preferably carried out by incorporating at least one metal boride, preferably MBβ, in particular LaBβ in the carrier medium with simultaneous comminution, preferably with grinding, as described in WO2007 / 107407. Of course, in this variant, a metal boride can be used, which is already present in the form of nanoparticulate particles. The metal boride to be comminuted is preferably used in non-nanoparticulate form. In particular, the metal borides to be comminuted initially have a size of from 500 nm to 50 μm, preferably from 1 to 20 μm.

The comminution is carried out in equipment suitable for this purpose, preferably in mills such as, for example, ball mills, stirred ball mills, stirred mills (stirred ball mill with pin grinding system), disk mills, annular chamber mills, twin-cone mills, three-roll mills and batch mills (see Arno Kwade, "Grinding and Dispersing with Stirred Media Mills: Research and Application ", Technical University of Braunschweig, FB Maschinenbau, Edition: 1, 2007) If desired, the grinding chambers are equipped with cooling devices for dissipating the heat energy introduced during the grinding process the ball mill Drais Superflow DCP SF 12, the circulation mill system ZETA from Netzsch-Feinmahltechnik GmbH or the disk mill from Netzsch Feinmahltechnik GmbH, Selb, Germany.

For milling, grinding media made of aluminum oxide, zirconium oxide or zirconium oxide doped with yttrium are frequently used. In the context of the method according to the invention, in the preparation of the preparation from step (b.), The grinding of the carrier media with the IR absorbers with aluminum oxide grinding bodies is preferably carried out. The advantage of such a grinding is that the abrasion occurring in the case of the grinding media made of zirconium oxide, which is generally used, which generally leads to clouding of the polymer composition, does not occur. The polymer compositions which are produced by means of the process according to the invention therefore preferably have only a low content of zirconium oxide. Preferably less than 0.2% by weight, based on the polymer composition, of zirconium oxide is contained, more preferably less than 0.15% by weight.

In a further preferred embodiment, therefore, the polymer compositions which are prepared by the process according to the invention from 0.001 to 1 wt .-%, more preferably 0.01 to 0.8 wt .-% and in particular 0.01 to 0.5 wt % of a nanoparticulate metal boride, preferably MBβ, in particular LaBβ, and only a low content of zirconium oxide. Preference is given to less than 50% by weight of zirconium oxide, based on the total amount of zirconium oxide and nanoparticulate metal boride, more preferably less than 40% by weight. Most preferably, the nanoparticulate metal borides have a weight-average particle diameter of at most 200 nm, preferably not more than 150 nm, in particular from 70 to 130 nm.

The comminution preferably takes place with the addition of the main amount, in particular at least 80% to 100% of the carrier medium.

The time required for comminution depends in a manner known per se on the desired degree of fineness or the particle size of the active ingredient particles and can be determined by the person skilled in the art in routine experiments. For example, grinding times in the range of 30 minutes to 72 hours have proved successful, although a longer period of time is also conceivable.

Pressure and temperature conditions during comminution are generally not critical, for example, normal pressure has proven to be suitable. As temperatures, for example, temperatures in the range of 10 ⁰ C to 100 ⁰ C have been found to be suitable, with a temperature increase usually leads to a reduction in grinding time.

In order essentially to prevent agglomeration or coalescence of the nanoparticulate IR absorbers and / or to ensure good dispersibility of the particulate phase in the carrier medium, the IR absorbers used can be surface-modified or surface-coated. For example the particles have on at least part of their surface a single- or multi-layer coating containing at least one compound with ionic, ionic and / or nonionic surface-active groups. The compounds having surface-active groups are preferably selected from the salts of strong inorganic acids, e.g. Nitrates and perchlorates, saturated and unsaturated fatty acids such as palmitic acid, margaric acid, stearic acid, isostearic acid, nonadecanic acid, lignoceric acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid and elaosteric acid, quaternary ammonium compounds such as tetraalkylammonium hydroxides, e.g. Tetramethylammonium hydroxide, silanes such as alkyltrialkoxysilanes and mixtures thereof. In a preferred embodiment, the nanoparticulate IR absorbers used according to the invention have no surface modifiers.

The preparation of the preparation from step (b.) Is preferably carried out by in situ comminution, especially in situ grinding, in the liquid carrier medium in which it is subsequently used. In this case, in particular after reaching the dispersed state, the carrier medium is no longer removed from the preparation and its proportion is at most reduced to the extent that the dispersed state is maintained. Any partial or complete replacement of the carrier medium is carried out by liquid-liquid reaction in which the dispersed state is maintained. Preferably, the carrier medium is no longer replaced after preparation of the preparation. However, it is possible to add at least one further component which is compatible with the carrier medium, provided that the dispersed state is retained. The addition of one or more further components may be carried out before, during or after the preparation of the dispersed preparation. Preferably, the preparation obtained by in situ comminution is subjected to further processing immediately after its preparation.

The solids content of the preparation from step (b) is preferably at least 1% by weight, particularly preferably at least 10% by weight, very particularly preferably at least 20% by weight and in particular from 20 to 40% by weight on the total weight of the preparation from step (b.).

The content of nanoparticulate IR absorber in the preparation from step (b.) Is preferably at least 1% by weight, more preferably at least 10% by weight, very preferably at least 20% by weight and in particular from 20 to 40% by weight .-% based on the total weight of the preparation from step (b.). The content of metal boride, in particular MBβ, of the preparation from step (b) is preferably at least 50% by weight, particularly preferably at least 65% by weight, based on the total solids content of the preparation.

As already mentioned, preparations containing waxes and nanoparticulate I R absorbers dispersed therein can also be used in step (b). The incorporation of nanoparticulate IR absorbers in waxes is normally done in a mixing apparatus, as known to those skilled in the art. The incorporation can in this case by means of a so-called flushing process, such as in unpublished European Patent Application 08159697.5. The nanoparticulate I R absorbers are often present in the form of a dispersion in a polar or aqueous solution. Batch kneaders, dispersion kneaders but also extruders with mixing units can be used as mixing apparatuses. With particular preference, the incorporation of the dispersion of the nanoparticulate I R absorbers takes place in a batch kneader. In this case, the temperature of the play dough, the ratio of the nanoparticulate I R absorber to the wax, the shear introduced and the duration of the shear is important. One can drive in the incorporation of the dispersions of the nanoparticulate I R absorbers in the wax a temperature program, starting at a slightly elevated temperature and then lowering the temperature to increase the viscosity of the mass. This improves the dispersion result. Preferably, the procedure is to melt the wax in the kneader and then to add the dispersion of the nanoparticulate I R absorbers in portions or at once. The wax can also be introduced as a melt in the mixing device. Preferably, a temperature of 50 to 150 ⁰ C is selected. Particularly preferably, the temperature is in the mixing unit between 70 and 120 ⁰ C. The transfer of the nanopartikulärene IR absorbers in the apolar environment of the wax phase, recognized by the fact that polar or aqueous solvent or water is separated, which liquid depending on the temperature in the form of Drops or as water vapor of the plasticine escapes.

The phase transition of the nanoparticulate I R absorbers from the polar dispersion into the wax produces a composition suitable for step (b.) Of the process according to the invention. The solvent can be separated from the composition in various ways. It may be withdrawn or evaporated from the mixing means or the preparation may be removed from the mixing means and then dried and optionally ground. In general, preparations are comminuted for ease of handling and further processing. In this case, the preparation can be granulated, pelleted or pulverized. For use as a liquid composition in step (b.) Of the process according to the invention, the composition is of course in the molten state.

The mixing of the liquid preparation from step (b.) With the polymer melt from step (a.) Is carried out in mixing apparatus known to those skilled in the art, for example mono- or co-extruders, and calenders. In this case, the provision of the polymer melt in step (a.) Can take place either before or simultaneously with the mixing process in step (c.). Preferably, the polymer melt is provided immediately before or during mixing. The provision of the liquid composition in step (b.) Is usually done prior to mixing in step (c). Preferably, the provided liquid composition is added to the polymer melt in one or more steps during the mixing in step (c.).

In a preferred embodiment of the process according to the invention, the provision of a polymer melt (a.) And the mixing (c.) Of the polymer melt with the preparation (b.) Takes place in the context of an extrusion, injection molding, blow molding or kneading process.

Preference is given in step (c.) To the preparation of polymer compositions by a so-called mass addition process. Specific mass addition processes which may be mentioned in detail include extrusion, also coextrusion, injection molding, blow molding or kneading. The liquid compositions from step (b.) Preferably have boiling temperatures and / or flame temperatures above the processing temperature used to prepare the polymer composition. In another preferred embodiment, liquid compositions from step (b.) Here preferably have boiling temperatures below and flame temperatures above the processing temperature used to prepare the polymer composition.

A removal, in particular a substantially complete removal, of the carrier medium of the liquid composition from step (b.) After incorporation into As a rule, a polymer is not required, which represents an advantage of the process according to the invention.

In the process of the invention, after mixing in step (c.), The polymer compositions are processed in step (d.). The processing takes place according to the usual, known in the art steps for the processing of plastics. In particular, the polymer compositions can be further processed by extrusion, compounding, processing into granules or pellets, processing into shaped articles by extrusion, also coextrusion, injection molding, blow molding or kneading in step (d.). The polymer compositions are preferably processed into films by extrusion or coextrusion (compare Saechtling Kunststoff Taschenbuch, 28th edition, Karl Oberbach, 2001).

Another object of the invention is a polymer composition prepared by the production method of the invention described above.

In a specific embodiment, the polymer compositions of the invention or the molded articles produced therefrom contain a thermoplastic polymer component or consist of a thermoplastic polymer component. Thermoplastics are characterized by their good processability and can be used in the softened state for. B. be processed by molding, extrusion, injection molding or other molding processes to form parts.

The polymer composition according to the invention may additionally comprise at least one additive which is preferably selected from colorants, antioxidants, light stabilizers, UV absorbers, hindered amine light stabilizers (HALS), nickel quenchers, metal deactivators, reinforcing and filling agents, anti-fogging agents, biocides, acid scavengers , Antistatics, other IR absorbers for long-wave IR radiation such as kaolin, antiblocking agents such as SiO2, light diffusers such as MgO or TiO2, inorganic or organic reflectors (for example aluminum flakes).

The total amount of optional further additives in the polymer composition is up to 15% by weight, based on the polymer melt from step (a.). Preferably, the amount of these additives 0.5 to 15 wt .-%, more preferably 0.5 to 10 wt .-% and in particular 0.5 to 7.5 wt .-%. These optional additives are added in the inventive preparation of the polymer composition either in one of the steps (a.), (B.), (C.) And / or (d.) Or in optional additional steps of the process. The addition of the additives can be carried out, for example, in step (a.) In the provision of the polymer melt or the polymers used for the polymer melt may already contain the additives. The addition of the additives may also be accomplished by providing the liquid composition in step (b.) Which already contains the additives. Also in the mixing in step (c.), Further additives may be added to the mixture of the polymer melt and the liquid preparation. Further additives can also be added to the polymer composition during processing (d.).

With the aid of the polymer compositions prepared by the process according to the invention, shaped articles can be produced. The shaped articles can be produced from the polymer composition produced according to the invention by methods known to the person skilled in the art, for example extrusion, coextrusion, injection molding and blow molding.

Another object of the invention is the use of the polymer compositions and the moldings in thermal management. Thermal management includes use in automobiles, architecture, residential and office buildings, warehouses, stadiums, airports, or other areas where the heat generated by incident heat radiation is undesirable.

The polymer compositions or moldings are preferably used in agriculture, in particular as films for greenhouses. Further preferred

Applications in agriculture include other agricultural films such as silage films, wrap-stretch silage films, packaging films such as stretch and stretch hoods or heavy-duty bags.

A further subject of the invention are films comprising the polymer composition prepared according to the invention, wherein the films have from 1 to 7 layers, preferably from 1 to 4 layers, in particular from 1 to 3 layers. Preferably, these films have a thickness of at most 500 .mu.m, preferably from 100 to 300 .mu.m, more preferably from 150 to 250 .mu.m, in particular from 150 to 200 .mu.m. The slides generally have a thickness of at least 30 microns. The films can be prepared, for example, by extrusion or coextrusion as described in Saechtling Kunststoff Taschenbuch, 28th edition, Karl Oberbach, 2001.

The moldings according to the invention are preferably also used as glazing or roofing material, as films in agriculture, in particular greenhouse films, or as part of windows.

Of course, with the aid of the shaped bodies according to the invention, it is also possible to produce objects, in particular components, which contain one or more shaped bodies. Such components can be used in particular for thermal management of buildings.

The use of the polymer compositions or moldings according to the invention containing nanoparticulate IR absorbers enables effective shielding against the effect of heat radiation on the surface of, for example, buildings, vehicles or greenhouses. These materials enable thermal management of interiors. In general, these materials provide high transparency to visible light while effectively shielding the heat radiation so that interior spaces remain bright in sunlight and do not heat up as much. Increased transparency, when using the polymer compositions in greenhouse films, has a direct positive effect on an increased yield of the plants grown in the greenhouse.

The invention is explained in more detail by the examples without the examples restricting the subject matter of the invention.

Examples:

Example 1 :

Production of agrofoils with heat management function

Quantities are given in wt .-% based on the total amount of the masterbatch or of the film. Since it is often difficult to dose small volumes of additives or homogeneously incorporated into a film, the additives are first processed in the form of a masterbatch. This ensures a homogeneous additization of a polymer that is processed into a film over the entire film surface and facilitates the process.

The following additives were processed into a masterbatch using an extruder:

1.25% nanoparticulate LaBβ prepared by in situ plasma synthesis, 15.0% Uvinu®l 5050H (HALS), 7.5% Uvinul® 3008 (UV absorber),

2.5% Irganox® B 225 (mixture Irgafos® 168 and Irganox® 1010 from Ciba, Antioxidant),

73.75% LDPE (Low Density Polyethylene).

Nanoparticulate LaBβ was added to the polymer melt (LDPE) via a liquid dosing, the ingredients other than powder or granules.

8% of the masterbatch along with 92% LDPE granules were added via silos to the hopper of the extruder, which then processed the ingredients to a homogeneous plastic composition. The molten polymer exited via a nozzle and was shaped by appropriate air flows to a film bubble, which was folded into a film after cooling and rolled up.

These films were used in a greenhouse and the temperature history compared with those in other greenhouse compartments in which standard films were used.

In winter, when using films of the invention at noon, the maximum temperature on average by up to 5 ⁰ C can be reduced. At night, however, only a 1-2 ⁰ C lower temperature was measured.

In the summer months, however, a temperature reduction of up to 10 ⁰ C at noon was detected.

Other films having the following compositions were prepared according to the method described above: Example 2:

Composition of the film:

1, 0% Uvinul® 5050H (HALS), 0.5% Uvinul® 3008 (UV absorber), 0.3% Irganox® 1010, 0.2% Irgafos® 168, 0.03% nanoparticulate LaB ₆ , 97, 97% Lupolen® 1840 D (PE).

This film has a reduction in the transmission of IR radiation in the wavelength range from 750 to 1500 nm of up to 50% compared to a film without nanoparticulate LaB ₆ .

This film also has a reduction in the transmission of IR radiation in the wavelength range of 750 to 1500 nm of up to 50% compared to a film with agglomerated non-nanoparticulate LaB ₆ particles (particle size, for example, from 1 .mu.m to 50 .mu.m).

The other film compositions of Examples 3 to 6 show a comparable reduction in the transmission, as in Example 2.

Example 3:

Composition of the film:

1, 0% Uvinul® 5050H, 0.5% Uvinul® 3008, 0.3% Irganox® 1010, 0.2% Irgafos® 168,

0.03% nanoparticulate LaB ₆ , 97.97% Lupolen® 1840 D.

Example 4:

Composition of the film:

1, 0% Uvinul® 5050H, 0.5% Uvinul® 3008, 0.3% Irganox® 1010, 0.2% Irgafos® 168, 0.0225% nanoparticulate LaB ₆ , 0.0075% Mark it® (antimony compound for laser marking) , 97.97% Lupolen® 1840 D.

Example 5

Composition of the film:

1, 0% Uvinul® 5050H, 0.5% Uvinul® 3008, 0.3% Irganox® 1010, 0.2 Irgafos® 168,

0.03% nanoparticulate LaB ₆ , 0.5% magnesium oxide, 97.47% Lupolen® 1840 D.

Example 6 Composition of the film:

0.03% nanoparticulate LaB ₆ , 0.1% K 1010 (Ni titanate), 97.87% Lupolen® 1840 D.

Claims

claims:

A process for producing a polymer composition comprising the following process steps a. Providing a polymer melt, b. Providing a preparation containing a liquid carrier medium and dispersed therein nanoparticulate IR absorbers, c. Mixing the polymer melt (a.) With the preparation (b.), D. Processing of the mixture (α).

2. The method according to claim 1, characterized in that the polymer melt contains one or more thermoplastic polymers.

3. Process according to claim 2, wherein the thermoplastic polymers are selected from polyolefins, polyolefin copolymers, polyvinyl alcohols, polyvinyl esters,

Polyvinylalkanals, polyvinyl ketals, polyamides, polyimides, polycarbonates, polycarbonate blends, polyesters, polyester blends, poly (meth) acrylates, poly (meth) acrylate-styrene copolymer blends, poly (meth) acrylate-polyvinylidene difluoride blends, Polyurethanes, polystyrenes, styrene copolymers, polyethers, polyether ketones, polysulfones, polyvinyl chloride.

4. The method according to claims 1 to 3, wherein the preparation of the preparation (b.) By plasma synthesis of the nanoparticulate IR absorber takes place.

5. The method according to claims 1 to 3, wherein the provision of the preparation (b.) By the comminution of the IR absorber in the carrier medium takes place.

6. The method according to claim 5, wherein the comminution of the IR absorber in the carrier medium is carried out by grinding.

7. The method of claim 5 or 6, wherein for comminuting the IR absorber is initially used not nanoparticulate form.

8. The method according to claims 1 to 7, wherein the nanoparticulate IR absorbers have a weight-average particle diameter of at most 200 nm.

9. The method according to claims 1 to 8, wherein the solids content of the preparation (b.) Based on the total weight of the preparation (b.), At least 1 wt .-% is.

10. The method according to claims 1 to 9, wherein the content of nanoparticulate IR absorber, based on the total solids content of the preparation (b.), At least 1 wt .-% is.

11. The process according to claims 1 to 10, characterized in that the nanoparticulate IR absorbers are metal borides, ATO, ITO, nanoscale

Ruse, or mixtures of these substances.

12. The method according to claim 1 1, characterized in that the metal borides are hexaborides of the general formula MBβ, where M is a metal component.

13. The method according to claims 1 to 12, wherein the liquid carrier medium is selected from esters of alkyl and arylcarboxylic acids, hydrogenated esters of A- rylcarbonsäuren with alkanols, mono- or polyhydric alcohols, ether alcohols, polyether polyols, ethers, saturated acyclic and cyclic hydrocarbons , Mineral oils, mineral oil derivatives, silicone oils, aprotic polar solvents, or mixtures thereof.

14. Process according to claims 1 to 12, wherein the liquid carrier medium is selected from polyolefin waxes and polyolefin comonomer waxes.

15. The method of claim 13, wherein the support medium is selected from ethylene glycol, glycerol, 1, 3-propanediol, 1, 4-butanediol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, acyclic or cyclic ethers, polyether polyols, low-boiling alcohols or hydrocarbons with boiling point less than 200 ⁰ C or mixtures of said carrier media.

16. Process according to claims 1 to 15, wherein the preparation (b.) Has a boiling temperature and / or flame temperature above that used for mixing (c.)

Processing temperature has.

17. Process according to claims 1 to 15, wherein the preparation (b.) Has a boiling temperature below the processing temperature used for mixing (c.).

18. Process according to claims 1 to 17, characterized in that the mixing (c.) Takes place with deposition of the carrier medium.

19. The method according to claims 1 to 18, wherein the polymer melt as further component additives selected from colorants, antioxidants, light stabilizers, UV absorbers, hindered amine light stabilizers, nickel quenchers, metal deactivators, reinforcing and fillers, anti-fogging agents, biocides, acid scavengers , Antistatic agents, other IR absorbers for long-wave IR radiation such as kaolin, antiblocking agents such as SiÜ2, light scatterers such as MgO or TΪO2, inorganic or organic reflectors are added.

20. Process according to claims 1 to 19, wherein the provision of a polymer melt (a.) And the mixing (c.) Of the polymer melt with the preparation (b.) Takes place in the course of an extrusion or kneading process.

21. Polymer compositions prepared according to claims 1 to 20.

22. Use of polymer compositions according to claim 20 in thermal mangement.

23. Use of polymer compositions according to claim 20 in agriculture.

24. Use of polymer compositions according to claim 20 in films for greenhouses.

25. Use of polymer compositions according to claim 20 as silage films, Wickelstretchsilagefolien, packaging films or heavy bags.

26. Films comprising polymer compositions according to claim 20, wherein the films have from 1 to 7 layers.

27. Films according to claim 26 or comprising polymer compositions according to claim 20, which have a thickness of at most 500 μm.