Pigment preparations
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Solution Overview
Problem
Metal azo pigments, particularly those based on azobarbituric acid and nickel salts, face limitations in heat stability, which restricts their application in high-temperature processing environments such as the coloring of plastics like polypropylene, polyester, and polyamide.
Innovation Solution
The development of pigment preparations containing metal azo pigments with specific metal ion compositions, including copper and nickel, combined with melamine and certain fatty acids, which form adducts that enhance heat stability by improving the molecular interactions and crystal lattice structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pigment surface is treated with additives to improve dispersion properties, then dispersion properties are improved, but color strength is lost
Solution Approach 1:
The patent applies parameter changes by carefully controlling the amount of fatty acid additive (70-210 g per 1 mol of metal azo compounds) and selecting specific chain lengths (C10-C22) to optimize the balance between dispersion properties and color strength. This quantitative parameter optimization allows improving dispersion without excessive color strength loss.
Solution Approach 2:
The patent creates a composite pigment preparation system combining metal azo pigments (with Cu2+ and Ni2+ ions), melamine derivatives, and fatty acids. This composite structure allows the fatty acid to modify the pigment surface for better dispersion while the melamine and metal complex maintain the color strength, resolving the contradiction between dispersion improvement and color strength preservation.
2Adaptability or versatility
If metal azo pigments are used for coloring plastics, then coloring capability is achieved, but heat stability is insufficient at high processing temperatures
Solution Approach 1:
The fatty acid acts as an intermediary substance that mediates between the metal azo pigment and the plastic matrix. It forms a protective interface layer that enhances heat stability during high-temperature processing while preserving the coloring capability. The melamine derivative also serves as a stabilizing intermediary that reinforces the pigment structure at elevated temperatures.
Solution Approach 2:
The patent modifies the chemical composition parameters of the pigment system by incorporating specific ratios of Cu2+ (97-100 mol%) and Ni2+ (0-3 mol%) metal ions, along with controlled amounts of fatty acid and melamine derivative. These parameter changes enhance the thermal stability of the pigment complex, allowing it to maintain its coloring capability at high processing temperatures typical for plastics like polypropylene and polyester.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The improved heat stability of these pigment preparations allows for their effective use in high-temperature applications, maintaining color strength and dispersibility while adjusting chroma and transparency, making them suitable for various pigment end uses, including synthetic and natural fibers, and printing materials.
Implementation Method 1
Metal complexes formed from azobarbituric acid with nickel salts... metal azo pigments A) containing the components a) at least two metal azo compounds of the formula (I)... Me1 is Cu2+ or Ni2+
Implementation Method 2
The components a) present in the metal azo pigments A) preferably form adducts together with the components b)... at least one aliphatic monocarboxylic acid B) having 10 to 22 carbon atoms
Data Source
AI summary
The novel pigment preparations containing at least one metal azo pigment A) and at least one aliphatic monocarboxylic acid B) having 10 to 22 carbon atoms are suitable for the colouring of plastics and in this connection feature improved heat stability.