A method for producing a pigmented polymer material
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Solution Overview
Problem
Existing methods for dyeing or printing polypropylene films face challenges such as poor ink adhesion, low dye substantivity, pale coloring, and high risk of ink transfer issues, due to the high hydrophobicity of polypropylene, which limits the affinity for inorganic and organic pigments.
Innovation Solution
A method involving a blend of a first polymer composition and a second polymer composition, where the second composition includes a binding agent consisting of an amine-terminated polyamide and a terpolymer of ethylene, acrylic or methacrylic ester, and glycidyl methacrylate, is used to dye or print polypropylene materials. This method involves heating the polymer material to an activation temperature, contacting it with an aqueous pigment composition, and then subjecting it to a fixation step to immobilize the pigment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polypropylene is used as the polymer material, then the material has good chemical resistance and durability, but the high hydrophobicity of polypropylene causes poor ink adhesion and low dye substantivity
Solution Approach 1:
A binding agent comprising a blend of at least one cationic polymer and at least one polymer having reactive groups is introduced as an intermediary substance. This binding agent is incorporated into the polymer material before printing, creating a receptive layer that mediates between the hydrophobic polypropylene substrate and the aqueous pigment composition, enabling effective pigment attachment without compromising the underlying polypropylene structure
Solution Approach 2:
The binding agent is incorporated into the polymer material in advance, before the printing process. This preliminary incorporation ensures that the polymer material already possesses the necessary affinity for aqueous pigments when the time comes for printing, eliminating the need for post-manufacturing surface treatments or activations
2Ease of manufacture
If conventional printing methods are used on polypropylene, then the process is simple, but the result is pale coloring and high risk of ink transfer
Solution Approach 1:
The binding agent serves as a mediator that enables strong pigment attachment to the polypropylene surface. By incorporating this binding agent beforehand, the printing process can use standard aqueous pigment compositions to achieve intense, vibrant colors without requiring specialized printing equipment or complex multi-step processes
Solution Approach 2:
The invention changes the chemical parameters of the polymer material by incorporating polymers with specific properties (cationic polymers and polymers with reactive groups). These parameter changes give the polypropylene surface enhanced affinity for aqueous pigments, allowing conventional printing methods to produce intense, transfer-resistant coloration
3Manufacturing precision
If surface activation treatments are applied to improve pigment affinity, then the adhesion improves, but the process complexity and cost increase
Solution Approach 1:
Instead of applying surface activation treatments after manufacturing, the binding agent is incorporated into the polymer material during the manufacturing process itself. This preliminary action ensures pigment affinity is built-in from the start, eliminating the need for subsequent surface treatment steps
Solution Approach 2:
The invention merges the function of the binding agent incorporation with the polymer material manufacturing process. By combining these steps, the need for separate surface activation treatments is eliminated, reducing overall process complexity while achieving the same pigment affinity enhancement
4Reliability
If protective coatings are applied to prevent ink transfer, then the print stability improves, but the device complexity and production time increase
Solution Approach 1:
The binding agent is incorporated into the polymer material in advance, before printing. This preliminary preparation creates a surface that inherently resists ink transfer, eliminating the need for subsequent protective coating applications and associated production time delays
Solution Approach 2:
The invention extracts the protective function from a separate post-printing coating layer and integrates it into the polymer material itself through the binding agent. This eliminates the need for additional protective coating steps while maintaining print stability
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 method achieves enhanced affinity for pigments, improved color intensity, stability, and fastness, with minimal risk of pigment removal upon water contact, without the need for surface activation treatments or protective coatings.
Implementation Method 1
a binding agent for the at least one pigment... comprising a blend consisting essentially of an amine terminated polyamide and a terpolymer of ethylene, acrylic or methacrylic ester and glycidyl methacrylate
Implementation Method 2
heating the polymer material to an activation temperature of at least 50 °C and below 150°C
Implementation Method 3
subjecting the pigmented polymer material to a fixation step to fixate the at least one pigment therein by cooling the pigmented polymer material to a fixation temperature which is lower than the temperature at which contacting of the polymer material with the aqueous pigment composition is carried out
Data Source
AI summary
The invention relates to a method for dyeing a polymer material with an aqueous pigment composition containing at least one pigment dispersed therein, wherein the polymer material is a blend comprising a first polymer composition and a second polymer composition which is compatible with the first polymer composition, which second polymer composition comprises a binding agent for the at least one pigment. The method comprises the steps of : - heating the polymer material to an activation temperature below the softening temperature of the polymer material, - contacting the polymer material with the aqueous pigment composition at a contact temperature for a period of time sufficient to form a pigmented polymer material, - subjecting the pigmented polymer material to a fixation step to fixate the at least one pigment therein by cooling the pigmented polymer material to a fixation temperature which is lower than the temperature at which contacting of the polymer material with the aqueous pigment composition is carried out.