The industry is well-known waterproof coating is mainly polyurethane system, which is isocyanate, polyether and other polymerized by the polymerization of isocyanic acid-based pre-polymerization, with catalysts, waterless fillers, solvents, etc., by mixing and other processes made.
Compared with the thermal viscosity and brittle characteristics of acrylic resin, polyurethane resin has the characteristics of hard but not brittle, soft and non-stick, the use of resin with this characteristic prepared waterproof coating, at normal low temperature fracture elongation, fracture strength is very good, can meet the waterproofing needs of most scenes.
with the consumption upgrade, environmental protection requirements gradually improve, environmental protection paint has been paid attention to.
how to upgrade a waterproof coating with a small amount of solvent to a high solid content system or solvent-free system, and how to switch to a water-based waterproofing system, has become a hot topic in the waterproof industry.
Resin emulsions used in conventional water-based coatings can be roughly divided into acrylic, EVA, polyurethane, etc.
In the same waterproof coating formulation conditions, waterproof coating mechanical performance, water absorption rate, bonding strength and other properties, what are the characteristics, please see the following explanation.1 mechanical performance waterproof coating mechanical performance, has been a characterization of the paint excellent or not one of the most important items, and the preparation of paint resin on its mechanical performance has the greatest impact.
Water-based polyurethane dispersion retains the soft and hard segment characteristics of the molecular segment of polyurethane resin, has good elasticity and strength, and the normal low temperature fracture elongation and fracture strength in waterproof coatings are also excellent: 2 alkali treatment mechanical properties waterproof coating directly applied to the concrete substrate, will be affected by the base pan-alkali, used indoors will also be affected by alkaline cleaning agent.
excellent alkali resistance, it extends coating life and provides long-lasting water resistance.
, water-based polyurethane waterproof coatings exhibit excellent alkali resistance.
3 absorption rate is too high, the coating after long-term immersion will dissolve, bubble, and grass-roots adhesion decreased, resulting in a decrease in waterproof capacity.
waterproof coating prepared with polyurethane and acrylic emulsion, its water absorption rate is as follows: The experimental results show that the PA coating shows different deformation: 4 bonding strength bond strength characterized paint adhesion to the substrate, the higher the strength, the better the adhesion, the less easy it is to fall off.
water-based polyurethane waterproof coating bonding strength is high, and there is no significant change in different substrates, expanding the application of waterproof coatings.
5VOCVOC, or volatile organic compound, has a great impact on human health.
When the VOC in the room reaches a certain concentration, people will feel headache, nausea, vomiting, fatigue, etc. in a short period of time, when severe convulsions, coma, and will harm the human liver, kidneys, brain and nervous system, resulting in memory loss and other serious consequences.
the interior decoration process of the paint is one of the main sources of indoor VOC, all countries have made restrictions on the content of paint and other decorative decoration materials VOC.
Water-based waterproof coatings perform extremely well on VOCs: In summary, water-based polyurethane dispersion system-ready waterproof coatings in the same formulation (shown below) exhibit better mechanical properties, lower water absorption and higher bonding strength, and lower VOC.
For example: water-based PU waterproof coating room temperature elongation rate of 620%, break strength 4MPa, water absorption rate of 8%, substation bonding strength 1.5MPa, VOC about 10g/L, can effectively cover the wall small cracks, reduce seepage, extend service life, etc., reduce the building waterproof repair rate, improve the quality of life.
Note: The PUD lotion used in this article is Archsol®8355 Statement: This number remains neutral on reprinting, sharing, statement, and opinion, for the purpose of industry communication only, and the copyright is owned by the original author.
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