Cold transfer printing paste, printing colorant thereof, and preparation method thereof
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Solution Overview
Problem
Existing printing pastes for cold transfer printing face issues with poor rheological properties, sensitivity to shear force, high cost, and instability in the presence of metal ions, leading to chromatic aberration and reduced color fastness.
Innovation Solution
A novel paste comprising polysaccharide, sodium L-pyrrolidonecarboxylate, and etherified starch, combined with a printing colorant that includes reactive dyes, defoamers, flattening agents, and pH stabilizers, which provides improved rheological properties, stability, and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If starch or modified starch is used as the principal component of printing paste, then the paste has good stability, but the rheological properties are poor
Solution Approach 1:
The patent uses a composite thickening system combining xanthan gum and carboxymethyl cellulose sodium salt in specific proportions (0.5-5% xanthan gum and 1-10% carboxymethyl cellulose sodium salt). This composite approach leverages the synergistic effects of two different polysaccharides to achieve both excellent stability and superior rheological properties, resolving the contradiction between stability and operability that plagues single-component starch-based systems.
2Ease of manufacture
If sodium alginate is used as the principal component, then the paste can be formed, but calcium ions or metal ions cause precipitation and chromatic aberration
Solution Approach 1:
The patent completely eliminates sodium alginate from the formulation and replaces it with alternative thickening agents (xanthan gum and carboxymethyl cellulose sodium salt). This extraction of the problematic component removes the source of metal ion interaction and precipitation, while the alternative agents provide equivalent or superior paste formation capabilities without the harmful sensitivity to calcium and other metal ions.
Solution Approach 2:
The patent substitutes expensive sodium alginate with more cost-effective alternatives (xanthan gum and carboxymethyl cellulose sodium salt). This replacement not only reduces material costs but also eliminates the chronic problem of metal ion-induced precipitation and chromatic aberration, providing a more economical and stable long-term solution.
3Ease of manufacture
If inorganic printing paste with montmorillonite powder or rectorite clay is used, then the paste can be formed, but it is not applicable in cold transfer printing process
Solution Approach 1:
The patent fundamentally changes the chemical composition parameters of the printing paste by using organic polysaccharide-based thickening agents instead of inorganic clay materials. This parameter change in composition enables the paste to exhibit appropriate rheological behavior specifically suited for cold transfer printing processes, while maintaining ease of manufacture through the use of commercially available food-grade or industrial-grade polysaccharide materials.
4Ease of manufacture
If modified starch formed through graft copolymerization is used, then the paste can be synthesized, but the colorant is sensitive to shear force and viscosity is lost during high-speed printing
Solution Approach 1:
The patent employs a composite thickening system of xanthan gum and carboxymethyl cellulose sodium salt that provides exceptional shear-thinning behavior and viscosity stability. This composite formulation maintains consistent viscosity under the shear forces encountered during high-speed cold transfer printing, eliminating the viscosity loss problem associated with grafted starch while keeping the paste easy to manufacture from simple mixing of the two polysaccharide components.
Data Source
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AI summary
The present invention relates to a cold transfer printing paste, a printing colorant and preparation methods thereof. Specifically, the present invention relates to: a cold transfer printing past, which contains polysaccharide, sodium L-pyrrolidonecarboxylate, an etherified starch and water; a printing colorant, which contains the paste of the present invention, an active dye, a defoamer, a flatting agent, a pH stabilizing agent and water; and preparation methods of the paste and the printing colorant. The cold transfer printing paste of the present invention and a printing colorant containing the paste are applicable in a cold transfer printing process, and have stable physical properties, thereby preventing decrease of the viscosity in use.