Toner with Insoluble-Soluble Polyester Blend for Fixability
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Solution Overview
Problem
Conventional toner production methods, such as the kneading pulverizing method, face challenges in achieving small particle diameters, uniform particle size distribution, and low-temperature fixability, leading to inadequate image quality and high fixing energy consumption, while methods like polymerization improve particle size but may compromise heat resistance and offset resistance.
Innovation Solution
A toner comprising a blend of polyester resin components A and B, where component A is insoluble in tetrahydrofuran and component B is soluble, with specific weight ratios and glass transition temperatures, enhancing low-temperature fixability, heat resistance, and charge stability through controlled molecular structure and compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the kneading pulverizing method is used to produce toner, then the production process is simple, but the particle diameter cannot be made small, the particle size distribution is broad, and the fixability at low temperature is poor
Solution Approach 1:
The patent changes the chemical composition parameters of the toner by incorporating specific polyester resins with defined glass transition temperatures and solubility characteristics. This transforms the production approach from purely mechanical (kneading pulverizing) to a combination of chemical formulation and controlled manufacturing, achieving narrow particle size distribution and small particle diameter while maintaining processability.
Solution Approach 2:
The patent creates a composite toner material consisting of multiple polyester resins with different properties (soluble and insoluble components, different glass transition temperatures) combined with specific additives. This composite approach allows simultaneous optimization of particle size distribution, fixability, and other performance characteristics that cannot be achieved with a single material.
2Temperature
If wax is added to improve fixability, then low-temperature fixability improves, but the toner cracks at interfaces with wax during pulverization, causing wax deposition on toner surface and leading to filming on carriers and photoconductors
Solution Approach 1:
The patent changes the chemical compatibility parameters between the toner resin and wax by selecting polyester resins with specific glass transition temperatures and solubility characteristics. This ensures the resin and wax remain compatible during pulverization, preventing cracking and wax deposition while maintaining low-temperature fixability.
Solution Approach 2:
The patent converts the potential harm of wax cracking during pulverization into a benefit by carefully selecting resin-wax combinations that remain compatible. The wax serves its dual function of improving fixability without causing the harmful cracking and deposition effects that occur with incompatible materials.
3Manufacturing precision
If polymerization method is used to produce toner, then particle diameter becomes small and particle size distribution becomes sharp, but heat resistant preservability and offset resistance may be compromised
Solution Approach 1:
The patent creates a composite resin system combining polyester resins with different glass transition temperatures and solubility characteristics. This composite approach allows the toner to achieve sharp particle size distribution through controlled polymerization while the specific resin combination provides heat resistant preservability and offset resistance that would not be obtained from a single resin.
Solution Approach 2:
The patent precisely controls the glass transition temperature parameters and solubility parameters of the polyester resins used in the polymerization process. By adjusting these parameters, the patent achieves both sharp particle size distribution and high heat resistant preservability, resolving the contradiction between particle size control and thermal 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 toner achieves improved low-temperature fixability, high-temperature offset resistance, and heat-resistant preservability, producing images with high glossiness and stable chargeability, while maintaining durability and image quality.
Implementation Method 1
The toner has a first glass transition temperature (Tg1st) of from 20° C. to 50° C., measured at a first temperature rising in differential scanning calorimetry (DSC)... TgA, TgB and TgAB represent second glass transition temperatures (Tg2nd), measured at a second temperature rising in differential scanning calorimetry
Implementation Method 2
a polyester resin component A (A) insoluble in tetrahydrofuran; and a polyester resin component B (B) soluble in tetrahydrofuran
Data Source
AI summary
A toner includes a polyester resin including a polyester resin component A (A) insoluble in tetrahydrofuran; and a polyester resin component B (B) soluble in tetrahydrofuran. The toner has a first glass transition temperature (Tg1st) of from 20° C. to 50° C., measured at a first temperature rising in differential scanning calorimetry (DSC), and satisfies the following formulae (1) and (2):T=1/{a/(TgA+273)+b/(TgB+273)}−273 (1)T−TgAB>30×a (2)wherein a and b represent weight ratios of (A) and (B) to a total weight of (A) and (B), and satisfy the equation a+b=1; and TgA, TgB and TgAB represent second glass transition temperatures (Tg2nd), measured at a second temperature rising in differential scanning calorimetry, of (A), (B), and a mixture of (A) and (B), respectively.