Pigment preparations

Abstract

The invention relates to pigment preparations containing or consisting of (a) at least one specific red and / or orange colored pigment; at least one polyolefin; and optionally (c) at least one dispersant.

Description

Pigment preparations Field of the invention

[0001] The invention is in the field of color pigments and relates to new preparations for red and orange pigments with improved stability. Technological background

[0002] Bulk coloring of polyamides with brilliant orange and red tones has been a challenge for applications since the banning of cadmium sulfide pigments (SVHC substances). Many shades in the red and orange range are either very expensive to achieve (e.g., using rare earth pigments) or impossible to achieve with the desired brilliance, especially when high fastness properties are required. This is due to the polar melt of the polyamide combined with its chemical reactivity. Most commercially available pigments are chemically degraded by the polyamide melt or dissolve into their molecular components, thereby uncontrollably changing their color and application properties. State of the art

[0003] DE1694487 A1 (ICI) describes pigmented polyamides produced by polymerizing a mixture of 90 to 99% by weight of hexamethylenediammonium adipate and 0% to 10% by weight of caprolactam in the presence of an organic pigment. Suitable pigments include quinacridone, phthalocyanine, and perylene pigments, e.g., copper phthalocyanine or the bis-N,N1-(31,51-dimethylphenyl)imide of perylene-3,4,9,10-tetracarboxylic acid.

[0004] EP1560877 B1 (BASF) relates to a process for producing a polyamide containing titanium dioxide pigments, wherein the titanium dioxide pigments are dispersed in a starting mixture containing water and caprolactam.

[0005] CN115594989 A (W00C0 PIGMENTS) discloses a process for producing a polyamide pigment preparation. The polyamide resin is produced by polymerizing dicarboxylic acid and diamine at high temperature in the presence of a phosphorus compound. The polymers are then mixed with a color sand.

[0006] JP2169736 A2 (ASAHI) relates to nylon 66, the main chain of which consists of amide bonds, which further contains 0.25 to 1.25 wt.% of a perylene-based red pigment. i

[0007] US 2016017144 A1 (HARRIS) relates to a highly loaded and well-dispersed masterbatch composition and methods for its preparation in a split-stream process. The masterbatch composition contains a colorant, a thermoplastic carrier, a metallocene polymer processing aid, and optionally an additive. The split stream may consist of a primary and a secondary feed. The primary and secondary feeds are combined by at least one of the following measures: feeding the secondary feed either into the same feed port as the primary feed, into a stream located upstream of the primary feed, into a stream located downstream of the primary feed, or a combination thereof.

[0008] US 2012123036 A1 (HOHNER) discloses pigment concentrates for coloring thermoplastics. Sections [0038-0039] indicate that the concentrates may contain polyolefins in addition to pigments.

[0009] US 2003019400 A1 (DECKERS) concerns pigment concentrates comprising color pigments, polyethylene and polyethylene waxes. Object of the invention

[0010] The object of the present invention was therefore to provide new orange and / or red pigments specifically for the mass coloration of polyamides, which are free from the disadvantages described above and, in particular, convey a brilliant and stable color impression during processing. Description of the invention

[0011] A first aspect of the invention relates to pigment preparations, in particular pigment preparations and pigment compounds, containing or consisting of (a) at least one colour pigment in amounts of 1 to 50% by weight; (b) at least one polyolefin in amounts of 50 to 99 wt.% and optionally (c) at least one dispersant in amounts of 0 to 20 wt.%, with the proviso that the amounts add up to 100 wt.%, and wherein the color pigments are red pigments or orange pigments selected from the group consisting of 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione and 2,2 '-((3,3 '-di chloro(1 ,1 '-bi phenyl) -4,4' -diyl) bis(2,1 -;2,2' - [(3,3' -d ich lorobi phenyl-4,4' -diyl)di (E)dia- zene-2,1 -diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1 H-benzimidazol-5-yl)butanamide] and mixtures thereof.

[0012] Surprisingly, it was found that incorporating the above-mentioned color pigments into a polyolefin matrix significantly improves the stability of the complex organic substances. improved and, in particular, no chemical degradation or color changes occur when they are incorporated, for example, into polyamide or polyamide masterbatches. It was particularly unexpected that this method would also allow the processing of existing pigments that were previously considered unsuitable for use in polyamides due to their insufficient stability. Furthermore, the amounts of polyolefins that enter the materials to be colored, especially polyamides, with the pigments are so small that they do not negatively affect the properties of the materials. Color pigments

[0013] The color pigments that can be used in the context of the invention are red pigments or orange pigments, as well as mixtures thereof. Two pigments that are already known per se have proven particularly suitable, namely Red 254: 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (CAS 84632-65-5) with the following structural formula: as well as Orange 72: 2,2'-((3,3'-dichloro(1,1'-biphenyl)-4,4'-diyl)bis(2,1 -;2,2 , -[(3.3 , -dichlorobiphenyl-4,4'-diyl)di(E)diazene-2,1-diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1H-benzimidazol-5-yl)butanamide] (CAS 78245-94-0) with the following structural formula: The pigments are available from various manufacturers (e.g., Heubach, Sun Chemical, Cinic). The pigment preparations can each contain only one pigment; these are then referred to as mono-preparations or "single pigment concentrates" (SPCs). However, mixtures of different color pigments, which can produce different shades, are also possible. Polyolefins

[0014] The core of the invention is to protect the color pigments against chemical or light-induced decomposition by embedding them in a polyolefin matrix. This can be, for example, polyolefins selected from the group consisting of polyethylene, such as HD polyethylene, LD polyethylene, and polypropylene. Dispersants

[0015] Preferably, the preparations may further contain dispersants which are selected, for example, from the group formed by polyolefin, montan or amide waxes as well as poly(meth)acrylic compounds and stearates Preparations

[0016] In a preferred embodiment of the invention, the preparations can be concentrates ("masterbatch") containing components (a) to (c) in the following amounts: (a) the said red and / or orange colour pigments in amounts of about 1 to about 50% by weight (b) at least one polyolefin in amounts of about 50 to about 99% by weight; and (c) at least one dispersant in amounts of about 5 to about 20% by weight, with the proviso that the amounts add up to 100% by weight.

[0017] Alternatively, compounds containing the components (a) to (d) in the following quantities: (a) the said red or orange colour pigments in amounts of about 0.1 to about 10% by weight (b) at least one polyolefin in amounts of about 0.1 to about 15 wt.%; (c) at least one dispersant in amounts of 0 to about 5% by weight, preferably about 0.1 to about 4% by weight; and (d) at least one polyamide in amounts of about 70 to about 99% by weight, provided that the quantities add up to 100% by weight.

[0018] To avoid misunderstandings, it should be noted that compositions that add up to more than 100 wt.% or less than 100 wt.% are not subject of the invention. Furthermore, the skilled person is readily able to identify compositions within the overall disclosure of the present patent application that satisfy the technical teaching without having to engage in inventive activity. H first I procedure

[0019] Another object of the invention relates to a process for producing a pigment masterbatch, consisting of or comprising the following steps: (i) providing at least one color pigment in amounts of 1 to 50% by weight; (ii) providing at least one polyolefin in amounts of 50 to 99 wt.% and optionally (iii) providing at least one dispersant in amounts of 0 to 20 wt%; (iv) melting the at least one polyolefin above its softening point; (v) dosing of at least one colour pigment and optionally at least one dispersant; (vi) Homogenization of the mixture by introducing shear energy and (vii) cooling the mass, with the proviso that the quantities add up to 100% by weight and wherein the colour pigments are red pigments or orange pigments selected from the group consisting of 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione and 2,2'-((3,3'-dichloro(1 , 1 '-biphenyl)-4,4'-diyl)bis(2, 1 -;2,2'-[(3,3'-dichlorobiphenyl-4,4'-diyl)di(E)diazene-2,1 -diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1 H-benzimidazol-5-yl)butan- amide] and mixtures thereof.

[0020] Preferably, the process is conducted such that a pigment concentration of about 2 to about 30 wt.%, and in particular about 20 to about 50 wt.%, is established in the masterbatch. The process is within the general experience of the person skilled in the art and can be carried out, for example, in a heatable stirred tank. Polyamide

[0021] Two further objects of the present invention relate to polyamide workpieces, including fibers containing the pigment preparations identified above, with amounts of about 0.5 to about 10 wt.% and in particular about 1 to about 5 wt.% being preferred. Examples of workpieces based on polyamides, in addition to the fibers already mentioned, are primarily household items and technical parts that must be highly abrasion-resistant, such as dowels, screws, housings, plain bearings, insulators in the electrical engineering field, cable ties, adhesive bases, plug connections, plugs, housing parts for electronic devices, plastic parts for electrical installations in vehicles and battery-operated systems, joint pieces for medical tents, kitchen utensils (ladles, spoons), machine parts (covers, gears, bearings, casters), and toothbrush bristles.Due to its resistance to lubricants and fuels at temperatures up to and above 150 °C, applications in vehicle construction are also possible, for example for engine components such as intake systems, fuel lines, engine covers, oil pans and for compressed air systems such as chassis and brakes. Industrial applicability

[0022] Another object of the invention relates to a process for producing a polyamide workpiece, in which a polyamide masterbatch is mixed with an amount of the pigment preparations identified above, homogenized and then brought into a mold.

[0023] Furthermore, the use of polyolefins for stabilizing color pigments selected from the group formed by 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione and 2,2'-((3,3'-dichloro(1 , 1 '-biphenyl)-4,4'-diyl)bis(2, 1 -;2,2'-[(3,3'-dichlorobiphenyl-4,4'-diyl)di(E)diazene-2,1 -diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1 H-benzimidazol-5-yl)butan- amide] and mixtures thereof. against chemical degradation when used in polyamides.

[0024] It should be noted that the above-mentioned preferred embodiments, mixtures, amounts and the like also apply to the above-mentioned processes and uses, so that repetition is unnecessary. EXAMPLES Example 1 Pigment concentrate with Red 254

[0025] A batch comprising 4.5 kg of LD-PE, 1.5 kg of polymer wax and 4 kg of the pigment Reds 254 was premixed in a high-speed mixer and then processed in a twin-screw extruder at 160 °C, cooled in a water bath and strand granulated. Example 2 Pigment concentrate with Orange 72

[0026] A batch comprising 4.5 kg of LD-PE, 1.5 kg of polymer wax and 4 kg of the pigment Orange 72 was premixed in a high-speed mixer and then processed in a twin-screw extruder at 160 °C, cooled in a water bath and strand granulated. Example 3 - Comparison Example V1 Application-related assessment

[0027] A batch of 10 kg polyamide was melted and homogenized by extrusion with 200 g of non-stabilized Pigment Red 254 and with 500 g of the monoconcentrate obtained according to Example 1 and processed into a workpiece by injection molding. This workpiece was later assembled with other components to create a more complex plastic device, which was exposed to weathering during long-term outdoor use. The polyamide test specimens were exposed to light, heat, and water in a weathering device for six weeks and then tested for their durability. While the coloring test with the unstabilized product failed in the first step of incorporating the pigment into the polyamide matrix because the pigment changed color, the masterbatch colored with the inventive concentrate proved to be coloristically stable even during the injection molding process. In the subsequent weathering test, it achieved the high color fastness typical for pigment chemistry.

Claims

PATENT CLAIMS 1. Pigment preparations containing or consisting of (a) at least one colour pigment in amounts of 1 to 50% by weight; (b) at least one polyolefin in amounts of 50 to 99 wt.% and optionally (c) at least one dispersant in amounts of 0 to 20 wt.%, with the proviso that the amounts add up to 100 wt.%, and wherein the color pigments are red pigments or orange pigments selected from the group consisting of 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione and 2,2'-((3,3'-dichloro(1 , 1 '-biphenyl)-4,4'-diyl)bis(2, 1 -;2,2'-[(3,3'-dichlorobiphenyl- 4,4'-diyl)di(E)diazene-2,1 -diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1 H-benzimidazol- 5-yl)butanamide] and mixtures thereof.

2. Preparations according to claim 1, characterized in that the polyolefins are selected from the group formed by HD polyethylenes, LD polyethylenes and polypropylenes.

3. Preparations according to at least one of claims 1 to 2, characterized in that the dispersants are selected from the group formed by polyolefin waxes, polyamide waxes and poly(meth)acrylic compounds and stearates 4. Preparations according to at least one of claims 1 to 5, characterized in that they contain components (a) to (c) in the following amounts: (a) the said red and / or orange colour pigments in amounts of about 1 to about 50% by weight (b) at least one polyolefin in amounts of about 50 to about 99% by weight; and (c) at least one dispersant in amounts of about 5 to about 20% by weight, with the proviso that the amounts add up to 100% by weight.

5. Compounds, characterized in that they contain components (a) to (d) in the following amounts: (a) the said red or orange colour pigments in amounts of about 0.1 to about 10% by weight (b) at least one polyolefin in amounts of about 0.1 to about 15 wt.%; (c) at least one dispersant in amounts of 0 to about 5% by weight, and (d) at least one polyamide in amounts of about 70 to about 99% by weight, with the proviso that the amounts add up to 100% by weight.

6. A process for producing a pigment masterbatch according to claim 1, consisting or comprising the following steps: (i) providing at least one color pigment in amounts of 1 to 50% by weight; (ii) providing at least one polyolefin in amounts of 50 to 99 wt.% and optionally (iii) providing at least one dispersant in amounts of 0 to 20 wt%; (iv) melting the at least one polyolefin above its softening point; (v) dosing of at least one colour pigment and optionally at least one dispersant; (vi) Homogenization of the mixture by introducing shear energy and (vii) cooling the mass, with the proviso that the quantities add up to 100% by weight and wherein the colour pigments are red pigments or orange pigments selected from the group consisting of 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione and 2,2'-((3,3'-dichloro(1, 1'-biphenyl)-4,4'-diyl)bis(2, 1 -;2,2'-[(3,3'-dichlorobiphenyl- 4,4'-diyl)di(E)diazene-2,1-diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1 H-benzimidazol- 5-yl)butanamide] and mixtures thereof.

7. The process according to claim 5, characterized in that a pigment concentration of about 1 to about 50 wt.% is set in the masterbatch.

8. Polyamide workpieces containing the pigment preparations according to at least one of claims 1 to 4.

9. Polyamide fibers containing the pigment preparations according to at least one of claims 1 to 4.

10. Polyamide workpieces or polyamide fibers according to claims 7 and / or 8, characterized in that they contain the pigment preparations in amounts of about 0.5 to about 10 wt.%.

11. A process for producing polyamide workpieces, in which a polyamide masterbatch is mixed with an amount of the pigment preparations according to at least one of claims 1 to 4, homogenized and then molded.

12. Use of pigment preparations according to at least one of claims 1 to 4 for the production of polyamide masterbatches.

13. Use of masterbatches for polyamide coloring containing pigment preparations according to at least one of claims 1 to 4 for the production of workpieces and fibers.

14. Use of polyolefins for stabilizing color pigments selected from the group formed by 3,6-Bis(4-chlorophenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione and 2,2'-((3,3'-dichloro(1,1'-biphenyl)-4,4'-diyl) bis(2,1-;2,2'-[(3,3'-dichlorophenyl-4,4'-diyl)di(E)diazene-2,1-diyl]bis[3-oxo-N-(2-oxo-2,3-dihydro-1H-benzimidazol-5-yl)butanamide] and mixtures thereof. against chemical degradation when used in polyamides.

Images