How to prepare low VOC colorants for high-solid solvent-based coatings?

With the increasingly strict laws and regulations on VOC emissions of coatings and inks, environmentally friendly coatings and inks are attracting more and more attention. Among them, high-solid formula technology has also become one of the potential development directions. The advantages of the high solid content system are: 1. Reduce solvent content, reduce system VOC emissions; Users only need to adjust the traditional solvent-based coating ink production and construction equipment can be applied to high solid content system, save time, reduce equipment modification costs and production application costs

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for high-solid solvent-based coatings, VOC in pigment concentrates typically used in the tonation process can be an important source of final paint VOC. How to reduce the introduction of this part of VOC? This article will focus on this problem to propose ideas and solutions.
How to reduce the demand for solvents in the formulation
If the VOC content of pigment concentrate is high, the VOC of the final product will change with the color after color adjustment, which also brings some difficulty to the quality control of the product VOC. Conversely, if the VOC of the pigment concentrate can be controlled at a lower level, when using this low VOC color palette, even if the amount of addition is high, there is no need to worry that the VOC of the final coating will exceed the scope of the regulations.
to reduce the VOC content of pigment concentrates to a lower level, the primary requirement is to reduce the demand for solvents in formulations, usually by using dispersants or abrasive resins with high efficiency to reduce adhesion.
Created Coating Additives business line teGO® VariPlus LK abrasive resin developed specifically for high-solid pigment concentrated pulp is a good example.
we have studied the performance of VOC and viscosity after the preparation of an iron oxide yellow concentrate in different abrasive resins. The formula and experimental results are as follows:
can be found: when the VOC reaches 310 g/L, the resulting concentrated slurry viscosity is close to 100,000 mPas, basically illiquid. If the abrasive resin in the formula is replaced with AriPlus LK, the viscosity of the slurry is reduced to 800 mPas. After further reducing the VOC to 110g/L of the slurry, the slurry still has a low viscosity. If you use the special dispersant TEGO ® 676 at the same time, the viscosity can be further reduced by about half.
the use of TEGO® VariPlus LK abrasive resin in addition to the preparation of low VOC-specific pigment concentrate, compared with competing resins, but also without increasing the viscosity of the color paste, increase the pigment content. For example, PY 154 pigments shown:
When using abrasive resins and dispersants for competing products, 35% of the pigment content of the pigment viscosity of 2000 mPas, then the VOC content of about 500 g/L. If TEGO® VariPlus LK and TEGO® Dispers 676 are used, the viscosity of the pigment content at 55% is approximately 2200 mPas, but the VOC content can be reduced to 191 g/L at this time.
using TEGO® VariPlus LK and TEGO® Dispers 676 meet both the need to reduce VOC and increase pigment content. This is also very beneficial for recipe costs. In the case of the same pigment content, the cost of the slurry may be lower, or the pigment content may be increased, and the formulation cost of the same color may be lower.
our application experience, the abrasive resin has proven similar application value in several other formulations.
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. TEGO® VariPlus LK Properties Introduction
Excellent anti-stick effect
TEGO® VariPlus LK resin mainly reduces viscosity in two ways: First, it is based on aldehyde resin abrasive resin, unlike the common solid supply form of aldehyde resin on the market, TEGO® Vari Plus LK is a liquid supply form, users can be directly added to the production kettle when used, do not need additional solvents for dissolution, easier to operate, save production costs; By reducing the interaction between pigment particles, a very low viscosity of the slurry can be obtained.
is very compatible with most resin systems
the study found that VariPlus LK is very compatible with most resin systems, such as alkaloid resin, 1K/2K polyester, 2K PU, thermoplastic acrylic acid, epoxy, nitro paint, etc. Mixing with most resin systems results in a clear and transparent mixture, as shown in the figure below.
" does not affect gloss, weather resistance, adhesion, resistance and other
. TEGO® VariPlus LK does not bring significant negative effects to coating performance, even better results such as gloss, weather resistance, adhesion, resistance, etc. Better flexibility is shown in the figure below.
" low temperature stability
. BOTH THE ® VariPlus LK abrasive resins and TEGO® Dispers 676 have good low temperature stability and do not crystallize for a month at 3 degrees C. As follows:
TEGO® VariPlus LK is a unique liquid supply form of low solvent content abrasive resin, more convenient production operation, can be used to prepare low VOC effective grinding resin, with TEGO® Dispers 676, can prepare low VOC content solvent pigment concentrate formula, can meet increasingly stringent VOC emission standards at the same time, the performance of the final coating can be less impact, can give paint manufacturers more room to adjust the formulation.
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