Polymer Particle Dispersion for Coating Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polymer dispersions used in coatings exhibit poor storage stability, water resistance, and solvent resistance, particularly when used in low-temperature and short-time drying conditions, and lack sufficient film forming properties.
Innovation Solution
The development of polymer particles comprising a urethane resin and an acrylic polymer with specific structural features, such as a gel fraction of 10% or more, and the inclusion of sulfonic acid groups, which are produced through a method involving emulsion polymerization to enhance crosslinking and molecular weight, improving film forming properties and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If water-based paints are used to replace organic solvent-based paints for environmental conservation and safety, then environmental friendliness and safety are improved, but the appearance of coating film and coating film performance such as weather resistance, water resistance, solvent resistance, and contamination resistance deteriorate
Solution Approach 1:
The invention uses a composite polymer particle system containing both polyurethane resin and acrylic polymer components within the same particle. This composite structure allows the water-based paint to achieve coating film performance comparable to organic solvent-based paints while maintaining environmental benefits, specifically improving water resistance, solvent resistance, and weather resistance through the synergistic combination of different polymer materials.
Solution Approach 2:
The invention changes the chemical composition parameters of the polymer particles by incorporating acrylic polymer components with specific functional groups (carboxyl, hydroxyl, or amino groups) into the polyurethane resin matrix. This parameter modification enables the water-based coating to achieve enhanced crosslinking density and intermolecular interactions, thereby improving the coating film's resistance to water, solvents, and weathering without requiring organic solvents.
2Reliability
If polymer particles with intraparticle mixture of resins are used to improve coating film performance, then water resistance and solvent resistance are improved, but storage stability of the dispersion deteriorates
Solution Approach 1:
The invention creates local quality differentiation within the polymer particle by forming an intraparticle mixture where the acrylic polymer component is distributed within the polyurethane resin matrix. This localized composition allows different regions of the particle to contribute different properties: the polyurethane resin provides structural integrity and storage stability, while the acrylic polymer domains provide enhanced water and solvent resistance, thus resolving the contradiction between improved resistance and maintained storage stability.
3Use of energy by moving object
If low temperature and short time drying conditions are applied for energy saving, then energy consumption is reduced, but water resistance and solvent resistance of the coating film deteriorate
Solution Approach 1:
The invention performs preliminary action by pre-forming the crosslinked structure and molecular weight during the polymer particle synthesis stage through emulsion polymerization. This preliminary crosslinking within the particles ensures that the coating film achieves adequate water resistance and solvent resistance even when subjected to low temperature and short time drying conditions, thereby reducing energy consumption without sacrificing coating performance.
4Reliability
If emulsion polymerization is used to produce polymer particles with crosslinked structure, then water resistance and solvent resistance are improved, but manufacturing complexity increases
Solution Approach 1:
The invention merges the polymerization process with crosslinking formation by conducting emulsion polymerization in the presence of crosslinking agents. This combined approach allows the formation of crosslinked acrylic polymer components within the polyurethane resin matrix during a single manufacturing step, thereby achieving improved water and solvent resistance without significantly increasing manufacturing complexity, as the crosslinking occurs concurrently with particle formation rather than as a separate subsequent step.
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 polymer dispersion demonstrates improved storage stability, paint viscosity characteristics, and enhanced water and solvent resistance, enabling the formation of coatings with excellent water and solvent resistance even under low-temperature and short-time drying conditions.
Implementation Method 1
a particulate polymer as a mixture of a urethane resin and an acrylic polymer obtained by emulsion polymerization of an acrylic monomer in an aqueous dispersion of the urethane resin
Implementation Method 2
the acrylic polymer does not have a crosslinked structure. As a result, the coating film obtained from a dispersion containing this polymer exhibits insufficient water resistance and solvent resistance
Data Source
AI summary
The present invention relates to: a polymer particle in which a urethane resin (A1) and an acrylic polymer (B1) are included in a single particle, said polymer particle having a gel fraction of 10% or more as measured using N,N-dimethylformamide (DMF) as a solvent; a polymer particle in which a urethane resin (A2) having a sulfonic acid group and an acrylic polymer (B2) are included in a single particle, said polymer particle having a surface acid value of 0.1 to 19 mgKOH/g as measured by a potentiometric titration method; and a method for producing a polymer dispersion. According to the present invention, it becomes possible to provide: a polymer dispersion which has excellent polymerization stability and can have an excellent coating viscosity property and excellent storage stability when used in a coating material; a method for producing the polymer dispersion; and a polymer particle contained in the polymer dispersion. It also becomes possible to provide: a coating material which enables the formation of a coating film that can have excellent water resistance and solvent resistance even when the drying conditions include a low temperature and a shorter drying time; and a coated material which has the coating material applied thereon.