DE10063422A1 - Use of mixtures of metallocene polyolefin waxes and other waxes or additives to improve the properties of lacquers, e.g. matt finish, antislip properties, hardness, abrasion resistance, surface feel and sandability - Google Patents

Abstract

Mixtures of metallocene polyolefin waxes and other waxes or additives are used to improve the properties of lacquers. Mixtures of components (A) and (B) are used to improve the properties of lacquers: (A) C2-C18 alpha -olefin (co)polymers produced using metallocene catalysts or degradation products of such (co)polymers; (B) either: (i) one or more waxes selected from polyethylene waxes, polytetrafluoroethylene (PTFE) waxes, polypropylene waxes, amide waxes, Fischer-Tropsch waxes, montan wax, natural waxes, macro- and microcrystalline paraffin waxes and polar polyolefin waxes or (ii) one or more additives selected from sorbitan esters, polyamides, polyolefins, PTFE, wetting agents and silicates. An independent claim is also included for lacquers containing the wax mixtures.

Description

The present invention relates to the use of metallocene waxes, the Oxidates and their mixtures with other waxes, as well as the corresponding micronisate for paints.

In the manufacture of paints, waxes are generally in one Add a concentration of 0.01-10%. These are PE waxes, PTFE waxes, PP waxes, amide waxes, FT paraffins, montan waxes, natural Waxes, macro- and microcrystalline paraffins, polyethylene copolymers, Sorbitan esters and metallocene waxes, and their mixtures, as in EP-A-0 890 619. The blends can be in different Combinations, both as powder and melt mixtures.

These waxes are added as flakes, granules, powders, dispersions, emulsions or as micronizates, the preferred form of use being able to be regarded as a finely micronized powder with particle sizes of up to 4 μm in DV ₅₀ value. (DV ₅₀ value: 50% of the wax particles are less than or equal to 4 µm). These waxes are used to achieve the following effects on the paints:

• - better scratch resistance
• - better abrasion resistance
• - better dispersion of pigments
• - better pigment stability
• - Improve the tendency to wean
• - Improve the redispersion of pigments
• - Orientation agent for effect pigments
• - good matting
• - a good grip  
• - Improvement of the gliding behavior
• - Improve metal marketing
• - achieve good incorporation of effect pigments
• - Influencing the rheological properties
• - better block resistance
• - better grindability
• - Degassing additive for powder coatings
• - Additive to increase throughput in powder coatings.

These wax additives can be used in all paint systems (e.g. low solids, medium solids, high solids, solvent-based paints, aqueous or water-borne paints, powder coatings, physically drying Coating systems, chemically curing coating materials, as well radiation-curing coating materials, such as. B. UV varnishes).

Since pure polyethylene waxes and metallocene waxes are not used in all paint systems, especially cannot be used in aqueous systems Wax oxidates used.

Since the individual types of wax show different effects in the varnishes, preferred wax mixtures between PE waxes, PTFE waxes, PP waxes, amide waxes, FT paraffins, montan waxes, natural waxes, macro- and microcrystalline paraffins, polyethylene copolymers, sorbitan esters and metallocene waxes are used to combine the above effects to combine and achieve corresponding improvements in paints.

The invention was based, such wax mixtures for the task To find use in paints, particularly many of the above Show effects. Surprisingly, the mixtures showed Metallocene grow the most noticeable improvements. What is special about these Mixtures improve the grindability for the production of wax micronisates, d. H. the yields are increased.  

Another advantage of using the waxes after the Metallocene processes have been produced, which is why they are easier to grind less auxiliary substances are used here than with wax mixtures with waxes, which were produced, for example, with the Ziegler-Natta process.

The invention relates to the use of mixtures of waxes which

• a) a homo- or copolymer of C ₂ -C ₁₈ -α-olefins produced by means of metallocene catalysis, and also degradation waxes produced from polyolefins of higher chain length produced by means of metallocene catalysis,

and as auxiliary substances one or more other waxes selected from the group consisting of

• a) PE waxing,
• b) PTFE waxing,
• c) PP waxing,
• d) amide waxes,
• e) FT paraffins,
• f) Montan growing,
• g) natural waxing,
• h) macro- and microcrystalline paraffins,
• i) polar polyolefin waxes, or
• j) sorbitan esters,
• k) polyamides,
• l) polyolefins,
• m) PTFE,
• n) wetting agents,
• o) silicates

included to improve the properties of paints.  

Another object of the invention are paints which described Wax blends included.

The homo- or copolymer of C ₂ -C ₁₈ -α-olefins (a) produced by means of metallocene catalysis preferably has the following properties:

Dropping point (Tp): 80-165 ° C
Acid number (SZ): 0-50 mg KOH / g
Density: 0.87-1.03 g / cm ³
Viscosity of the melt at 170 ° C: 10-100,000 mPas.

Homopolymers of ethylene or propylene or come as polyolefin waxes Copolymers of ethylene or propylene with one another, or with one or several 1-olefins in question. Linear or branched olefins are used as 1-olefins with 4-18 carbon atoms, preferably 4-6 carbon atoms. These olefins can an aromatic conjugation with the olefinic double bond Have substitution. Examples include 1-butene, 1-hexene, 1-octene or 1- Octadecene and styrene. Copolymers of ethylene with propene or are preferred 1-butene. Such ethylene-containing copolymers consist of 70-99.9, preferably 80- 99% by weight of ethylene.

Polyolefin waxes with a dropping point between 90 and 160 ° C., preferably between 100 and 155 ° C., a melt viscosity at 140 ° C. between 10 and 10,000 mPas, preferably between 50 and 5000 mPas and a density at 20 ° C. between 0 are particularly suitable , 89 and 0.96 g / cm ³ , preferably between 0.91 and 0.94 g / cm ³ .

Metallocene waxes such as those modified by oxidation are also suitable for example by treating the wax melt with air in accordance with EP-A-0 896 591 can be obtained. The disclosure of this document regarding the Oxidative treatment of wax melts is hereby incorporated into the present application involved.  

Metallocene catalysts for the preparation of the polyolefin waxes are chiral or nonchiral transition metal compounds of the formula M ¹ L _x . The transition metal compound M ¹ L _x contains at least one metal central atom M ¹ to which at least one π ligand, e.g. B. a cyclopentadienyl ligand is bound. In addition, substituents such. B. halogen, alkyl, alkoxy or aryl groups to the metal central atom M ¹ . M ¹ is preferably an element of III., IV., V. or VI. Main group of the periodic table of the elements, such as Ti, Zr or Hf. Cyclopentadienyl ligand is understood to mean unsubstituted cyclopentadienyl radicals and substituted cyclopentadienyl radicals such as methylcyclopentadienyl, indenyl, 2-methylindenyl, 2-methyl-4-phenylindenyl, tetrahydroindenluorenyl or octaeste hydro- nyl or octaeste hydro- nylorenes. The π ligands can be bridged or unbridged, single and multiple bridging - also via ring systems - being possible. The term metallocene also includes compounds with more than one metallocene fragment, so-called multinuclear metallocenes. These can have any substitution pattern and bridging variant. The individual metallocene fragments of such multinuclear metallocenes can be of the same type or different from one another. Examples of such multinuclear metallocenes are e.g. B. described in EP-A-0 632 063. Examples of general structural formulas of metallocenes and for their activation with a colocatalyst are given, inter alia, in EP-A-0 571 882. The disclosures of these items in the two documents are hereby incorporated.

In preferred embodiments, additive b) is Polyethylene homo- and copolymer waxes, which are not by means of metallocene catalysis were produced, and which have a number average molecular weight of 700 to 10,000 g / mol at a dropping point between 80 and 140 ° C.

In preferred embodiments, additive c) is Polytetrafluoroethylene with a molecular weight between 30,000 and 2,000,000 g / mol, in particular between 100,000 and 1,000,000 g / mol.  

In preferred embodiments, additive d) is Polypropylene homo- and copolymer waxes, not by means of metallocene catalysis were produced, and which have a number average molecular weight of 700 to 10,000 g / mol at a dropping point between 80 and 160 ° C.

In preferred embodiments, additive e) is Amide waxes, producible by reacting ammonia or ethylenediamine with saturated and / or unsaturated fatty acids. The fatty acids are for example, stearic acid, tallow fatty acid, palmitic acid or erucic acid.

In preferred embodiments, additive f) is FT- Paraffins with a number average molecular weight of 400 to 800 g / mol a dropping point of 80 to 125 ° C.

Additive g) is preferably montan waxes including acid and ester waxes with a carbon chain length of the carboxylic acid from C ₂₂ to C ₃₆ .

The ester waxes are preferably reaction products of Montanic acids with monohydric or polyhydric alcohols with 2 to 6 carbon atoms, such as Example ethanediol, butane-1,3-diol or propane-1,2,3-triol.

In a preferred embodiment, additive h) is Carnauba wax or candelilla wax.

Additive i) is paraffins and microcrystalline waxes, which incurred in oil refining. The dropping points of such paraffins are located preferably between 45 and 65 ° C, that of such microcrystalline waxes preferably between 73 and 100 ° C.

In preferred embodiments, additive j) is polar polyolefin waxes which can be prepared by oxidation of ethylene or propylene, homopolymer and copolymer waxes or their grafting with maleic anhydride. Polyolefin waxes with a dropping point between 90 and 165 ° C., in particular between 100 and 160 ° C., a melt viscosity at 140 ° C. (polyethylene waxes) or at 170 ° C. (polypropylene waxes) between 10 and 10,000 mPas, in particular between, are particularly preferred for this 50 and 5000 mPas and a density at 20 ° C between 0.8b and 0.96 g / cm ³ .

In preferred embodiments, additive k) is Reaction products of sorbitol (sorbitol) with saturated and / or unsaturated Fatty acids and / or montanic acids. The fatty acids are Examples include stearic acid, tallow fatty acid, palmitic acid or erucic acid.

Additive l) is preferably ground polyamide, for example polyamide-6, polyamide-6,6 or polyamide-12. The particle size of the Polyamides are preferably in the range of 5-200 microns, especially 10-100 microns.

Additive m) is a polyolefin, for example polypropylene, Polyethylene or copolymers of high or low density propylene and ethylene with molecular weights of preferably 10,000 to 1,000,000 D, in particular 15,000 up to 500,000 D as the number average for the molecular weight, the particle size of Grinding is in the range of preferably 5-200 microns, in particular 10-100 microns.

Additive n) is thermoplastic PTFE with a molecular weight of preferably 500,000-10,000,000 D, in particular 500,000-2,000,000 D as a number average, the particle size of which is preferably by grinding 5-200 µm, in particular 10-100 µm,

Additive o) is an amphiphilic compound which in Generally lower the surface tension of liquids. Both Wetting agents are, for example, alkyl ethoxylates, fatty alcohol ethoxylates, Alkylbenzenesulfonates or betaines.  

Additive p) is a silicate, which is not a filler or Pigment can be used in the recipes. Silicic acids or are preferred Talcum used.

The mixing ratio of component a) to components b) to p) can be in Range can be varied from 1 to 99 wt .-% a) to 1 to 99 wt .-% b) to p). Becomes If a mixture of several of the components b) to p) is used, then the Quantity specification for the sum of the quantities of these components.

In a preferred embodiment, the waxes are used in micronized form for the purpose according to the invention. The use of polyolefin wax and optionally admixed auxiliaries and additives as ultra-fine powder with a particle size distribution d ₉₀ <40 μm is particularly preferred.

U. a. matting of the paints, dispersibility and stability (Tendency to settle or cream) in paints and dispersions, an improvement in Slip friction, hardness and abrasion resistance, increase in throughput and Improvement of pigment dispersion in powder coatings, better antiblocking and Sensation of grip (soft feeling). The wax mixtures are in generally about powder or melt mixtures.

Examples

Table 1

Characterization of the components of the wax mixtures used

Table 2

Wax mixtures (all mixtures micronized to DV ₅₀ = 8 µm)

Preparation of an aqueous wax dispersion from a micropowder

1% by weight of Tylose® is stirred into 60% by weight of water and left to swell briefly, then 39% by weight of micronized, oxidized wax is added to the tylose solution dispersed.

Table 3

Dispersion / stability of wax mixtures

Incorporation of an aqueous wax dispersion in an aqueous acrylic paint: 4% by weight of the wax dispersion mentioned in Example 2 is converted into 96% by weight aqueous acrylic varnish (based on Mowilith® LDM 7460) stirred in and then with a squeegee (60 µm wet film thickness) mounted on a glass plate. To the gloss is determined after drying.

Table 4

Gloss of wax mixtures

Incorporation of micronized waxes into a standard nitrocellulose lacquer for matting and sliding friction

2 wt .-% micronized wax in 98 wt .-% NC lacquer using a Dispersed in the dissolver and then with a squeegee (60 µm Wet film thickness) on a glass plate. After drying, the shine certainly.

Table 5

Gloss and sliding friction of the wax mixtures

Incorporation in a white hybrid powder coating to improve the Pencil hardness and abrasion resistance

The waxes are mixed with the individual raw materials in a high-speed mixer mixed together, then the raw materials are put on a laboratory Twin screw extruder (PC19-25 from APV) extruded at 110 ° C; ground on <125 µm and applied to aluminum or steel sheet. after baking (15 min. at 180 ° C) the coated sheets are stored in the climatic room for 24 hours, then the pencil hardness (according to Wolff-Wilborn) determined and the abrasion test on Taber Abraser determined.

Table 6

Pencil hardness and abrasion test

Incorporation in a blue hybrid powder coating to improve the Dispersion and throughput improvement:

The waxes are mixed with the individual raw materials in a high-speed mixer mixed together, then the raw materials are put on a laboratory Twin screw extruder (PC19-25 from APV) extruded at 110 ° C Dosing quantity set to a power consumption of 70% on the extruder,  the throughput is recorded, ground to <125 µm and on aluminum or Steel sheet applied. After baking (15 min. At 180 ° C) the coated sheets stored in the climatic room for 24 hours, then the color depth measured.

Table 7

Color depth

Incorporation in an alkyd resin varnish to assess the block properties and of the grip impression

2 wt .-% micronized wax is in the alkyd resin varnish using a dissolver incorporated, then with the help of a squeegee (60 µm wet film thickness) Lacquer applied to glass (at least 2 plates each). After 24 hours storage in The handle is assessed (subjectively) in the climatic room, then the panels in the Warm cabinet stored at 50 ° C for 24 hours. The plates with the Coating placed on top of each other and loaded with a 500 g weight.

The block behavior is then assessed.  

Table 8

Assessment of block behavior

Table 9

Grip behavior of the wax mixtures

Incorporation into a 2-component PUR lacquer, apply to wooden boards and assess the Sandability:  

2 or 4% by weight of micronized wax in the 1 component of a 2K Disperse the polyurethane coating system, then add the second component and apply with a brush to a wooden board in the cloister. After that Allow to dry in the climate room for 24 hours. Then carry out a grinding test, a sheet of sandpaper (240 grit) is stretched on a wooden block, passed 20 × over the wooden board without pressure and the abrasion was then assessed. The less sandpaper is used, the better the sandability.

Table 10

Grindability of additive lacquers

Claims (10)

1. Use of mixtures of waxes, which

• a) a homo- or copolymer of C ₂ -C ₁₈ -α-olefins produced by means of metallocene catalysis, and also degradation waxes produced from polyolefins of higher chain length produced by means of metallocene catalysis,

and as auxiliary substances one or more other waxes selected from the group consisting of

• a) PE waxing,
• b) PTFE waxing,
• c) PP waxing,
• d) amide waxes,
• e) FT paraffins,
• f) Montan growing,
• g) natural waxing,
• h) macro- and microcrystalline paraffins,
• i) polar polyolefin waxes, or
• j) sorbitan esters,
• k) polyamides,
• l) polyolefins,
• m) PTFE,
• n) wetting agents,
• o) silicates

included to improve the properties of paints. 2. Use according to claim 1, wherein component a) is an oxidate of a Metallocene wax is. 3. Use according to claim 1 and / or 2, wherein it is in component a) is a homo- or copolymer of ethylene or propylene.   4. Use according to one or more of claims 1 to 3, wherein the wax mentioned as constituent a) has a melt viscosity at 140 ° C. of 10 to 10,000 mPas. 5. Use according to one or more of claims 1 to 4, wherein the wax mentioned as component a) has a density of 0.87 to 1.03 g / cm ³ . 6. Use according to one or more of claims 1 to 5, wherein the as component b) a wax not produced by means of metallocene catalysis Polyethylene wax with a number average molecular weight of 700 to 10,000 g / mol is. 7. Use according to one or more of claims 1 to 6, wherein the as component d) a wax not produced by means of metallocene catalysis Polypropylene wax with a number average molecular weight between 700 and 10,000 is g / mol. 8. Use according to one or more of claims 1 to 7, wherein the as component j) with a wax by oxidation or grafting Maleic anhydride is modified polyethylene or polypropylene wax. 9. Use micronized waxes as in one or more of the Claims 1 to 8 defined. 10. Lacquers comprising wax mixtures according to one or more of the Claims 1 to 9.