Toner Composition Using Polysiloxane Derivatives for Hot Offset Resistance
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Solution Overview
Problem
Toner formulations using ethylene-vinyl acetate copolymers for low temperature fixability suffer from poor hot offset resistance and flowability issues due to the hydrophobic nature of the copolymers, which limits the effectiveness of incorporated release agents and polysiloxane derivatives.
Innovation Solution
A toner composition combining an ethylene-vinyl acetate copolymer with specific polysiloxane derivatives A and B, where derivative B has a high affinity for the copolymer to retain derivative A within the toner, enhancing hot offset resistance without compromising flowability, achieved through an emulsion aggregation method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an ethylene-vinyl acetate copolymer is used as a binder resin to improve low temperature fixability, then low temperature fixability is improved, but hot offset resistance deteriorates
Solution Approach 1:
The patent uses a composite binder resin system combining ethylene-vinyl acetate copolymer (for low temperature fixability) with polyester resin and polypropylene resin (for hot offset resistance). This composite material approach allows the toner to achieve both low temperature fixability and good hot offset resistance by leveraging the complementary properties of different resins.
2Reliability
If a polysiloxane derivative is incorporated to improve hot offset resistance, then hot offset resistance is improved, but flowability deteriorates due to migration during long term storage
Solution Approach 1:
The patent introduces a specific polyester resin as an intermediary substance that mediates between the polysiloxane derivative and the ethylene-vinyl acetate copolymer. The polyester resin has compatible polarity with both components, acting as a bridge that prevents phase separation and migration of the polysiloxane derivative, thereby maintaining flowability while preserving hot offset resistance.
Solution Approach 2:
The patent carefully controls the molecular weight, glass transition temperature, and chemical structure parameters of the polyester resin to optimize its mediating function. By adjusting these parameters, the polyester resin maintains the polysiloxane derivative in a dispersed state without migration, ensuring both flowability and hot offset resistance are preserved during long term storage.
3Temperature
If the ethylene-vinyl acetate copolymer content is increased to enhance low temperature fixability, then low temperature fixability is improved, but compatibility with release agents deteriorates
Solution Approach 1:
The patent creates a composite resin system where polyester resin and polypropylene resin are combined with ethylene-vinyl acetate copolymer. This composite structure provides alternative compatible phases for hydrophobic release agents like alkyl waxes, preventing incompatibility issues even when ethylene-vinyl acetate copolymer content is high (50-100 mass%).
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 toner exhibits improved low temperature fixability, excellent hot offset resistance, and maintained flowability even after long-term storage, with the polysiloxane derivatives effectively incorporated to prevent migration and plasticization.
Implementation Method 1
derivative B has a high affinity for the copolymer to retain derivative A within the toner
Implementation Method 2
aggregating particles in a dispersed solution that contains resin fine particles in an aqueous medium so as to form aggregate particles
Data Source
AI summary
A toner including: a binder resin containing an ethylene-vinyl acetate copolymer; a polysiloxane derivative A represented by structural formula 1; and a polysiloxane derivative B represented by structural formula 2:(in structural formula 1, R1 to R10 each independently represent a methyl group or a phenyl group, and l, m and n each independently represent an integer of at least 1)(in structural formula 2, at least one of R11 to R20 is an organic group having a C4-30 alkyl group, a C4-30 alkoxy group, an acrylic group, an amino group, a methacrylic group or a carboxyl group, the remaining groups among R11 to R20 each independently represent a methyl group or a phenyl group, and p, q and r each independently represent an integer of at least 1).