Aqueous Gel Ballpoint Pen Ink Flow Pore and Storage Modulus Control
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Solution Overview
Problem
Conventional aqueous gel ballpoint pens with needle type ballpoint pen tips suffer from reduced storage stability and writing performance due to ink viscosity increase and pigment sedimentation over time, especially when the ink flow pore diameter is small.
Innovation Solution
The solution involves controlling the storage modulus of the aqueous gel ink within specific ranges (1.3≦G′≦16r−3.2 Pa) in conjunction with optimizing the ink flow pore diameter (0.24≦r≦0.64 mm) to ensure stable ink flow and prevent pigment sedimentation, thereby enhancing storage stability and writing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the ink flow pore diameter is reduced in a needle type ballpoint pen tip, then the pen can be manufactured with smaller dimensions and finer line output, but the storage stability deteriorates due to increased ink viscosity and pigment sedimentation
Solution Approach 1:
The patent applies parameter changes by precisely controlling the storage modulus G' of the aqueous gel ink within the range 1.3 ≤ G' ≤ 16r−3.2 Pa, where r is the ink flow pore diameter. This parameter control prevents pigment sedimentation and maintains ink fluidity in small-diameter needle type tips while enabling fine line output and compact pen design
2Ease of manufacture
If conventional aqueous gel inks are used in needle type ballpoint pen tips, then the pen can be produced with standard ink formulations, but the storage stability is insufficient due to ink viscosity increase over time
Solution Approach 1:
The patent modifies the ink formulation parameters by controlling the storage modulus G' within a specific range that depends on the ink flow pore diameter. This ensures that even with standard needle type tip manufacturing, the ink maintains adequate fluidity and prevents clogging during storage
Solution Approach 2:
The patent applies preliminary anti-action by pre-controlling the storage modulus of the ink before it is put into the pen. This preventive measure counteracts the natural tendency of ink to increase in viscosity and cause sedimentation during storage, ensuring stable performance without requiring special tip designs
3Reliability
If the storage modulus of ink is increased to prevent pigment sedimentation, then the storage stability improves, but the ink fluidity through small ink flow pores deteriorates
Solution Approach 1:
The patent resolves this contradiction by establishing an optimal range for storage modulus G' that balances both requirements. The formula 1.3 ≤ G' ≤ 16r−3.2 Pa ensures that the ink has sufficient viscosity to prevent pigment sedimentation while maintaining enough fluidity to flow through small ink flow pores in needle type tips
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
This approach significantly improves the storage stability and writing performance of aqueous gel ballpoint pens with needle type tips by maintaining ink fluidity and preventing pigment localization, ensuring consistent line density and reducing thin spots in written lines.
Implementation Method 1
an ink flow pore diameter r (unit: mm) in the ballpoint pen tip and a storage modulus G′ (unit: Pa) at 20° C. of the aqueous gel ink satisfy conditions represented by the following formulas (1) and (2): 0.24≦r≦0.64 (1), and 1.3≦G′≦16r−3.2 (2)
Implementation Method 2
there has been proposed an aqueous ink for a ballpoint pen which contains xanthan gum and a noncrosslinked polyacrylic acid having a predetermined molecular weight and the like
Implementation Method 3
proposals for increasing the storage stability have been made
Data Source
AI summary
An aqueous gel ballpoint pen 1 having an ink-storage tube storing an aqueous gel ink containing a pigment as a coloring agent, and a ballpoint pen tip having a ball rotatably held at its leading end and also having an ink flow pore which is formed so that the aqueous gel ink flows from the ink-storage tube to the ball, wherein an ink flow pore diameter r (unit: mm) in the ballpoint pen tip and a storage modulus G′ (unit: Pa) at 20° C. of the aqueous gel ink satisfy conditions represented by the following formulas (1) and (2):0.24≦r≦0.64 (1), and1.3≦G′≦16r−3.2 (2).