Electrostatic Toner with 1,2-Propanediol Polyester
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Solution Overview
Problem
Toner production for electrostatic image development faces challenges with excessive pulverization during the pulverization step, leading to low yield and generation of fine powders, particularly when using resin binders with 1,2-propanediol and rosin compounds.
Innovation Solution
A method involving melt-kneading a resin binder containing a polyester obtained by polycondensing 1,2-propanediol and a carboxylic acid component with a rosin compound and an aliphatic dicarboxylic acid, followed by pulverization and classification, which suppresses pulverization pressure and fine powder generation, enhancing yield and properties like low-temperature fixing ability and thermal-resistant storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a resin binder containing polyester obtained by polycondensing 1,2-propanediol and rosin compound is used, then low-temperature fixing ability is improved, but excessive pulverization occurs during the pulverization step
Solution Approach 1:
The patent changes the chemical composition parameters of the resin binder by specifying precise ratios of 1,2-propanediol (65-85 mol%) and adding specific dicarboxylic acids (adipic acid, sebacic acid, etc.) to modify the polyester structure. This parameter optimization reduces excessive pulverization while maintaining low-temperature fixing ability.
Solution Approach 2:
The patent creates a composite resin binder system combining polyester with specific additives including dibutyl phthalate (5-20 parts by weight per 100 parts polyester) and metal salts. This composite formulation balances the pulverization characteristics with the fixing performance.
2Productivity
If excessive pulverization occurs during pulverization step, then yield is reduced and fine powders are generated
Solution Approach 1:
The patent optimizes the resin binder's molecular structure by controlling the polycondensation of 1,2-propanediol with specific carboxylic acid components and adding plasticizers. These parameter changes produce a resin with controlled pulverization characteristics that reduces fine powder generation and improves yield.
Solution Approach 2:
The patent introduces dibutyl phthalate as an intermediary substance that mediates between the resin binder and the pulverization process. This plasticizer acts as a buffer that reduces excessive pulverization while maintaining the necessary binding properties.
3Reliability
If resin binder contains polyester with specific composition for low-temperature fixing, then storage property and filming resistance are improved, but pulverization pressure increases
Solution Approach 1:
The patent carefully balances the composition parameters of the polyester, controlling the mol% of 1,2-propanediol (65-85%) and incorporating specific dicarboxylic acids to achieve the right softening point range. This parameter optimization reduces pulverization pressure while maintaining storage stability and filming resistance.
Solution Approach 2:
The patent applies local quality modification by adding specific functional components (dibutyl phthalate, metal salts) in controlled amounts to specific regions of the resin binder system, creating localized properties that reduce pulverization pressure without compromising overall reliability.
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 method results in toners with excellent low-temperature fixing ability, high-temperature offset resistance, and thermal-resistant storage properties, with reduced pulverization pressure and fine powder generation, thereby improving pulverization and classification yield.
Implementation Method 1
a polyester obtained by polycondensing an alcohol component containing 1,2-propanediol and a carboxylic acid component containing a rosin compound and an aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms
Implementation Method 2
step 1: melt-kneading components containing a resin binder and a charge control agent to provide a melt-kneaded product
Data Source
AI summary
A method for producing a toner for electrostatic image development containing at least a resin binder and a charge control agent, including step 1: melt-kneading components containing a resin binder and a charge control agent to provide a melt-kneaded product; and step 2: pulverizing the melt-kneaded product, and classifying a pulverized product, wherein the resin binder contains a polyester A obtained by polycondensing an alcohol component containing 1,2-propanediol and a carboxylic acid component containing a rosin compound and an aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms, wherein 1,2-propanediol is contained in the alcohol component of the polyester A in an amount of 85% by mol or more. The toner for electrostatic image development obtained by the method of the present invention can be suitably used in, for example, the development or the like of latent image formed in electrophotography, an electrostatic recording method, an electrostatic printing method, or the like.