Solvent-Based Pigment Paste VOC Reduction
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Solution Overview
Problem
Solvent-based pigment pastes typically have high VOC (Volatile Organic Compound) content, leading to environmental concerns and safety issues due to the release of organic solvents, and existing solutions do not adequately address the problem of high VOC levels while maintaining practical viscosity and corrosion protection.
Innovation Solution
A solvent-containing pigment paste formulation using methoxypropyl acetate, propylene glycol diacetate, and urea-aldehyde resin with a branched-chain polyester or polyester block copolymer as wetting and dispersing agents, achieving a viscosity of 400 to 4,000 mPas and a flash point greater than 45 °C, which reduces VOC content and eliminates the need for explosion-proof measures in tinting machines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional organic solvents are used in pigment paste, then good dispersion and processing properties are achieved, but high VOC content and flash point safety issues occur
Solution Approach 1:
The patent changes the chemical parameters of the solvent system by replacing traditional high-VOC organic solvents with a specific solvent composition containing methoxypropyl acetate (5-50 wt%), propylene glycol diacetate (30-70 wt%), and water (5-40 wt%). This parameter change reduces VOC content to less than 500 g/l while maintaining the necessary dissolution and dispersion properties for pigment paste processing.
Solution Approach 2:
The patent uses a composite solvent system combining multiple solvents with different properties (methoxypropyl acetate for dissolution, propylene glycol diacetate for viscosity control, and water for VOC reduction). This composite approach allows the pigment paste to achieve both good processing properties and reduced harmful emissions simultaneously.
2Object-generated harmful factors
If solvent content is reduced to lower VOC, then environmental compliance improves, but viscosity control and corrosion protection deteriorate
Solution Approach 1:
The patent adjusts the solvent composition parameters to maintain adequate solvent content (50-95 wt% total solvents) for corrosion protection while reducing VOC content below 500 g/l. The specific balance of methoxypropyl acetate, propylene glycol diacetate, and water provides both low VOC and sufficient protective properties.
Solution Approach 2:
The patent introduces propylene glycol diacetate as an intermediary substance that bridges the gap between VOC reduction and corrosion protection. This solvent component provides both viscosity control and protective film formation, enabling the system to achieve low VOC content while maintaining reliable corrosion protection.
3Object-affected harmful factors
If flash point is increased for safety, then explosion risk decreases, but solvent effectiveness and drying properties worsen
Solution Approach 1:
The patent changes the flash point parameter by selecting solvents with inherently higher flash points. The combination of methoxypropyl acetate, propylene glycol diacetate, and water achieves a flash point greater than 45°C, reducing explosion risk while maintaining adequate drying properties through the balanced solvent composition.
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 solvent-containing pigment pastes achieve a significant reduction in VOC content to less than 500 g/l, maintain high flash points for safety, and provide effective corrosion protection with a long-lasting category C5-I coating performance, while being universally applicable across various coating compositions without requiring adjustments.
Implementation Method 1
a solvent-based pigment paste for tinting coating compositions, containing or consisting of a1) methoxypropyl acetate, n-propyl lactate and/or 2-ethylhexyl lactate, in particular methoxypropyl acetate, as solvent, a2) propylene glycol diacetate, ethylene glycol diacetate and/or butylene glycol diacetate, in particular propylene glycol diacetate, as solvent, b) at least one pigment
Implementation Method 2
c) at least one aldehyde-based resin, in particular urea-aldehyde resin, and/or at least one ketone-based resin, in particular at least one aldehyde-based resin
Data Source
AI summary
The present invention relates to a solvent-containing pigment paste for tinting coating compounds, comprising: a1) methoxypropyl acetate, n-propyl lactate and/or 2-ethylhexyl lactate as solvents, a2) propylene glycol diacetate, ethylene glycol diacetate and/or butylene glycol diacetate as solvents, b) a pigment, c) an aldehyde-based resin and/or a ketone-based resin, and d) a wetting and/or dispersing agent. The invention further relates to a kit-of-parts coating system comprising: a) at least one solvent-containing pigment paste according to the invention, and b) a coating compound.Furthermore, the invention relates to the use of the solvent-based pigment pastes according to the invention in tinting machines for tinting solvent-based paints, varnishes, and glazes, in particular 2K epoxy resin systems, 2K PU resin systems, 1K epoxy resin systems, 1K PU resin systems, and alkyd resin systems, for the production of tinted coating systems, and for ensuring a flash point greater than or equal to 45 °C. Finally, the invention relates to a tinted coating system obtainable from the kit-of-parts coating system according to the invention, as well as coatings obtainable by applying the tinted coating system according to the invention to a substrate surface.