Cationic Surface Sizing Agent via Surfactant-Free Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cationic surface sizing agents are susceptible to environmental factors such as water hardness and pH, leading to instability and inadequate sizing properties on paper and paperboard, especially when applied to different types of paper or under varying conditions.
Innovation Solution
A method involving solution-polymerization of a monomer mixture containing a tertiary amino group, (meth)acrylic acid ester, and styrenes in the presence of a chain transfer agent, followed by polymerization with nonionic hydrophilic and hydrophobic monomers without surfactants, and quaternization of the tertiary amino group to produce a cationic surface sizing agent with improved stability and sizing properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solution-polymerization is used to produce cationic surface sizing agent, then good sizing property is achieved, but stability against water hardness and pH is insufficient
Solution Approach 1:
The patent uses a composite polymer system combining a cationic polymer (with tertiary amino groups) and a water-soluble polymer in specific weight ratios (0.1-10:1). This composite structure allows the cationic polymer to provide sizing properties while the water-soluble polymer enhances stability against water hardness and pH variations, resolving the contradiction between sizing effectiveness and environmental stability.
Solution Approach 2:
The patent optimizes specific parameters including the weight ratio of cationic polymer to water-soluble polymer (0.1-10:1), the amount of water-soluble polymer (1-50 parts by weight per 100 parts cationic polymer), and pH range (5-9) to achieve both good sizing properties and enhanced stability against environmental variations.
2Stability of the object's composition
If emulsion polymerization is used without organic solvent, then environmental stability is improved, but sizing property effect is inferior
Solution Approach 1:
The patent combines emulsion-polymerized cationic polymer with water-soluble polymer in optimized ratios, where the water-soluble polymer compensates for the inferior sizing effect of emulsion polymerization while maintaining environmental stability. This composite approach achieves both stability and sizing effectiveness.
Solution Approach 2:
The water-soluble polymer acts as an intermediary that enhances the performance of the emulsion-polymerized cationic polymer, improving sizing properties without compromising the environmental stability already achieved through surfactant-free emulsion polymerization.
3Stability of the object's composition
If surfactant is used in emulsion polymerization, then stability against environment of usage is improved, but sizing property effect is reduced
Solution Approach 1:
The patent uses a composite of surfactant-free emulsion-polymerized cationic polymer and water-soluble polymer, where the water-soluble polymer compensates for any stability deficits from omitting surfactants while maintaining sizing effectiveness, achieving both goals without traditional surfactants.
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 resulting cationic surface sizing agent exhibits excellent dispersion stability and sizing properties regardless of water conditions or paper types, ensuring uniform distribution and enhanced hydrophobicity on the surface, even when applied to papers without internal sizing agents.
Implementation Method 1
quaternization of the tertiary amino group to produce a cationic surface sizing agent
Implementation Method 2
solution-polymerization of a monomer mixture containing a tertiary amino group, (meth)acrylic acid ester, and styrenes
Data Source
AI summary
The present invention relates to a method for producing a cationic surface sizing agent, and contains a first step of obtaining a copolymer (A) by solution-polymerizing a monomer mixture which contains a monomer having a tertiary amino group (a) in the amount of 15 to 45% by weight, a (meth)acrylic acid ester (b) in the amount of 15 to 85% by weight, and styrenes (c) in the amount of 0 to 70% by weight in the presence of a chain transfer agent; a second step of obtaining a copolymer (B) by polymerizing the copolymer (A) and a nonionic hydrophilic monomer (d); a third step of obtaining a copolymer (C) by polymerizing the copolymer (B) and a hydrophobic monomer (e) in the absence of a surfactant; and a fourth step of obtaining a quaternary ammonium salt of the copolymer (C) by quaternizing a tertiary amino group present in the copolymer (C).