Polyurethane Blade Cured Layer Formation
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Solution Overview
Problem
The existing methods for producing blade members in electrophotographic image forming devices face issues with the stability of surface treatment liquids containing isocyanate compounds, as polymerization reactions occur prematurely, leading to gelation and uneven curing, which affects the blade's performance and longevity.
Innovation Solution
A method involving the use of a surface treatment liquid with a carbodiimide-modified polyvalent isocyanate compound and a salt of diazabicycloundecene, where the polymerization reaction is suppressed at ordinary temperatures and promoted during heating, ensuring stable impregnation and even curing of the blade member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the isocyanate compound and polymerization catalyst are mixed in advance to prepare the surface treatment liquid, then the polymerization reaction progresses at ordinary temperature before heating, but gelation is caused and the surface treatment liquid becomes unstable
Solution Approach 1:
The patent extracts the polymerization catalyst from the surface treatment liquid formulation, using only the isocyanate compound without adding a separate catalyst. This eliminates the premature polymerization reaction that causes gelation, while still achieving effective curing through the isocyanate compound's inherent reactivity with moisture and other substrates.
Solution Approach 2:
The patent introduces a solvent as an intermediary medium to dissolve the isocyanate compound and create a stable surface treatment liquid. The solvent prevents premature reaction by providing a stable dissolution environment, allowing the liquid to remain stable during storage and application while enabling controlled curing when applied to the blade member.
2Reliability
If the isocyanate compound and polymerization catalyst are mixed immediately before impregnation, then gelation is avoided, but polymerization reaction progresses during impregnation treatment causing cured product formation on surface and uneven curing
Solution Approach 1:
The patent removes the polymerization catalyst from the formulation, preventing polymerization during impregnation while maintaining liquid stability. This ensures uniform impregnation throughout the blade member without premature cured product formation on the surface, achieving both stability and curing uniformity.
Solution Approach 2:
The isocyanate compound performs dual functions: it serves as both the reactive curing agent and the effective surface treatment component. The compound naturally reacts with moisture and substrates without requiring an external catalyst, enabling controlled polymerization during heating while maintaining stability during storage and impregnation.
3Ease of operation
If a polyurethane rubber blade portion is used with high friction coefficient, then cleaning effectiveness is achieved, but surface treatment is required to increase surface hardness
Solution Approach 1:
The patent creates a composite structure by impregnating the polyurethane rubber blade member with a carbodiimide-modified isocyanate compound that forms a cured layer. This combines the soft, high-friction polyurethane base material that provides effective toner removal with a hardened surface layer that increases surface hardness and durability, achieving both cleaning effectiveness and surface strength.
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 allows for a stable and long-lasting blade member with enhanced impregnation properties and improved curing, preventing premature gelation and ensuring effective removal of residual toner from photoreceptors.
Implementation Method 1
a cured layer formation step of heating and curing the carbodiimide-modified polyvalent isocyanate compound which is impregnated into the blade portion, to form a cured layer
Data Source
AI summary
A method for producing a blade member 1 includes an impregnation step of impregnating at least a portion of a surface of a blade portion 11 made of a polyurethane rubber with a surface treatment liquid that includes a salt of diazabicycloundecene and a carbodiimide-modified polyvalent isocyanate compound including a carbodiimide-modified polyvalent isocyanate dimer and a carbodiimide-modified polyvalent isocyanate trimer or higher multimer, in which a content of the trimer or higher multimer is 50% by mass or less, and a cured layer formation step of heating and curing the carbodiimide-modified polyvalent isocyanate compound which is impregnated into the blade portion 11, to form a cured layer 110.