Polyurethane (PU) waterproof coatings, also known as polyurethane coated waterproof materials, are a class of polymer waterproof materials with polyurethane resin as the main film-forming substance.Polyurethane waterproof coating is a reactive coating waterproof material formed by mixing a mixture of isocyanate-based (-NCO) polyurethane prepromers and curing agents containing polycarbonyls (-OH) or amine groups (-NH2) and other additives in a certain proportion.Products are divided into two types of single-component (S) and multi-component (M) according to their components.According to the basic properties, it is divided into type I, TYPE II and TYPE III, according to whether it is exposed to use, it is divided into exposed (E) and non-exposed (N), and according to the limit of hazardous substances, it is divided into category A and Category B.

Product features：　

Before curing, it is an amorphous viscous liquid substance, which is easy to construct on the surface of any complex base layer, easy to handle the ends, and easy to guarantee the quality of waterproof engineering; it is formed by chemical reaction, almost solvent-free, small volume shrinkage, and easy to make a thicker coating film. The waterproof layer of the coating film has no joints and strong integrity; cold construction operations, safe operation; the coating film has rubber elasticity, good extensibility, high tensile strength and tear strength; it has strong adaptability to cracks in the base layer within a certain range.

Scope of application：　

It is suitable for waterproof projects of various underground buildings, kitchens, bathrooms, and toilets; leak-proof of sewage ponds; waterproof and anticorrosive of underground pipelines, and waterproof of high-speed rail and bridge structures.

Construction process：　

◎ Basic requirements: flat, sturdy, and fully dry (no obvious wet stains can be found in underground projects); the yin and yang angles should be made into an arc shape, the diameter of the yin angle is greater than 50mm, and the diameter of the yang angle is greater than 10mm.；

◎ Ingredients: According to the construction dosage.Mix the A/B components in a ratio of 1:2 and stir well；

◎ Large-surface waterproof construction: The mixed coating is evenly coated with rubber or plastic scrapers, and the thickness is required to be consistent, generally 1.5mm-2.0mm. It should be brushed 3-4 times. The next brushing should be done after the previous brushing is cured into a film, and the scraping is carried out in a vertical direction.Reference dosage of coating: The approximate dosage of 1mm thick coating film is: 1.5-1.7kg/m2 (1.5mm thick generally uses about 2.4 kg/m2); generally, it is a separate film, and the underground engineering floor should be covered with an additional layer of carcass reinforcing material.；

◎ Coating thickness: The underground project is 1.2-2.0mm, which should generally be 1.5mm thick, and the toilet and bath room should not be less than 1.5mm. When the exposed roofing project is multi-channel waterproof, the thickness of each channel is not less than 1.2mm. When the waterproof level is 111, the roof is fortification, the thickness of the waterproof layer is not less than 2mm, and when the carcass reinforcing material is added between the coatings, the thickness of the coating under the carcass is not less than 1.0mm, and the coating on the top is not less than 0.5mm；

◎ Closing head and edge treatment: additional coating for closure；

◎ Protective layer: The surface of the coated waterproof layer should be isolated and protected according to the design requirements to prevent damage to the coated waterproof layer.