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CN-117487446-B - High-density rigid polyurea coating and preparation method thereof

CN117487446BCN 117487446 BCN117487446 BCN 117487446BCN-117487446-B

Abstract

The application relates to a high-density rigid polyurea coating and a preparation method thereof. The polyurea coating comprises a component A and a component B, wherein the component A comprises, by weight, 10-30 parts of isocyanate modified MDI, 5-20 parts of polyether glycol, 15-35 parts of polymeric MDI, 30-45 parts of barium sulfate and 1-2 parts of a first auxiliary agent, and the component B comprises, by weight, 30-50 parts of polyether polyol, 10-20 parts of an amino chain extender, 20-40 parts of barium sulfate, 5-10 parts of a water scavenger, 2-5 parts of color paste, 0.5-2 parts of a second auxiliary agent and 0.2-0.5 part of a catalyst. Barium sulfate is added into both the component A and the component B of the polyurea coating, so that the problems of more fillers and poor storage stability in the component A (modified isocyanate component) of the polyurea coating are successfully solved, the prepared polyurea coating is high in density and good in compactness, and the corrosion resistance of the coating is remarkably improved.

Inventors

  • LIU HUILAI
  • YU YANJUN

Assignees

  • 石家庄玮士奇新材料有限公司

Dates

Publication Date
20260505
Application Date
20231009

Claims (5)

  1. 1. The high-density rigid polyurea coating is characterized by comprising an A component and a B component, wherein the raw materials for preparing the A component and the B component both contain barium sulfate filler; The preparation raw materials of the component A comprise, by weight, 10-30 parts of isocyanate modified MDI, 5-20 parts of polyether glycol, 15-35 parts of polymeric MDI, 30-45 parts of barium sulfate and 1-2 parts of a first auxiliary agent; The preparation of the component A comprises the following steps: S1, mixing barium sulfate, polymeric MDI and a first auxiliary agent, grouting, and then filling into a closed container for nitrogen filling and sealing to obtain barium sulfate grouting material; S2, pumping polyether glycol into a reaction kettle in vacuum, adding isocyanate modified MDI for addition polymerization, adding the barium sulfate grouting material after the reaction is finished, and preserving heat to obtain the component A; In the step S1, the sealing time is 25-35 days, in the step S2, the temperature of the addition polymerization reaction is 75-85 ℃ and the time is 2-3 hours, and the heat preservation time is 20-40 minutes; the preparation raw materials of the component B comprise, by weight, 30-50 parts of polyether polyol, 10-20 parts of amino chain extender, 20-40 parts of barium sulfate, 5-10 parts of water scavenger, 2-5 parts of color paste, 0.5-2 parts of second auxiliary agent and 0.2-0.5 part of catalyst, wherein the catalyst is an organic bismuth catalyst; the preparation of the component B comprises the following steps: T1, mixing barium sulfate, a first part of polyether polyol, a water scavenger and a second auxiliary agent, grouting, and then filling into a closed container for nitrogen filling and sealing to obtain a B-component partial pressure slurry; t2, adding the rest polyether polyol and the amino chain extender into a reaction kettle, heating to 50-60 ℃, adding color paste and a catalyst, mixing, adding the B-component partial pressure slurry, and mixing again to obtain the B-component; In the step T1, the polyether polyol in the first part accounts for 30-40 wt% of the total amount of the polyether polyol, and the sealing time is 25-35 days.
  2. 2. The polyurea coating of claim 1, wherein the first auxiliary agent is a wetting dispersant.
  3. 3. The polyurea coating of claim 1 or 2, wherein the water scavenger is a molecular sieve selected from at least one of a 3A molecular sieve and a 4A molecular sieve.
  4. 4. The polyurea coating according to claim 1 or 2, wherein the polyurea coating is sprayed after mixing the component A and the component B in a volume ratio of (0.8-1.2).
  5. 5. The method for preparing a polyurea coating according to any one of claims 1-4, wherein the method comprises the steps of preparing an A component and preparing a B component, wherein the preparation of the A component comprises the steps of: S1, mixing barium sulfate, polymeric MDI and a first auxiliary agent, grouting, and then filling into a closed container for nitrogen filling and sealing to obtain barium sulfate grouting material; S2, pumping polyether glycol into a reaction kettle in vacuum, adding isocyanate modified MDI for addition polymerization, adding the barium sulfate grouting material after the reaction is finished, and preserving heat to obtain the component A; In the step S1, the sealing time is 25-35 days, in the step S2, the temperature of the addition polymerization reaction is 75-85 ℃ and the time is 2-3 hours, and the heat preservation time is 20-40 minutes; the preparation of the component B comprises the following steps: T1, mixing barium sulfate, a first part of polyether polyol, a water scavenger and a second auxiliary agent, grouting, and then filling into a closed container for nitrogen filling and sealing to obtain a B-component partial pressure slurry; t2, adding the rest polyether polyol and the amino chain extender into a reaction kettle, heating to 50-60 ℃, adding color paste and a catalyst, mixing, adding the B-component partial pressure slurry, and mixing again to obtain the B-component; In the step T1, the polyether polyol in the first part accounts for 30-40 wt% of the total amount of the polyether polyol, and the sealing time is 25-35 days.

Description

High-density rigid polyurea coating and preparation method thereof Technical Field The application relates to the technical field of polyurea coatings, in particular to a high-density rigid polyurea coating and a preparation method thereof. Background The polyurea is usually formed by two-component reaction, and the polyurea coating has excellent corrosion resistance and ageing resistance, particularly has excellent corrosion resistance in the aspects of resisting atmospheric corrosion, low-acid-alkali medium and inorganic salt solution, is convenient to construct on site, has high adhesive force, is difficult to crack in a coating, has strong permeation resistance, is a novel material in the current corrosion prevention field, and has the characteristics of long-acting and wide applicability. In the 70 s, 100% solid rigid polyurea anticorrosive coating technology is successfully developed in North America, and is one of the most widely used anticorrosive coating technology in North America, represents the development direction of the twenty-first century coating industry, has a successful application history in more than thirty years all over the world, has advanced spraying technology, stable quality, fast coating solidification, convenient and quick construction and extremely high efficiency, and can be widely applied to corrosion prevention of various matrixes such as steel, cast iron, cement and the like. The prior art discloses a polyurea coating and a preparation method thereof, wherein the polyurea coating comprises a component A and a component B, the component A comprises, by mass, 30-60 parts of polyisocyanate, 5-20 parts of acrylic acid modified polyurethane emulsion, 5-20 parts of epoxy modified acrylic resin, 10-15 parts of polycarbonate polyol and 10-15 parts of polyether polyol, and the component B comprises, by mass, 20-35 parts of amino-terminated polyether, 20-30 parts of amino chain extender, 1-15 parts of modified nano inorganic filler, 12-18 parts of organosilicon diamine, 10-15 parts of (methyl) acrylic ester, 0.1-1 part of leveling agent and 0.1-1 part of defoaming agent. A small amount of filler is added into the component B in the polyurea coating, so that the prepared polyurea coating has low density and thinner coating thickness, and therefore, the corrosion resistance of the coating needs to be further improved, and the coating is not suitable for being applied to various industrial heavy-duty corrosion prevention fields. Disclosure of Invention In order to solve the defects in the prior art, the application provides the high-density rigid polyurea coating and the preparation method thereof, wherein barium sulfate filler is added into two components (A component and B component) of the polyurea coating, so that the prepared polyurea coating has higher density and compactness, the density can be 1.5kg/cm 3, the corrosion resistance of the coating is obviously improved, and the coating is suitable for various industrial heavy-duty corrosion prevention fields. To this end, the first aspect of the present application provides a high density rigid polyurea coating comprising an A component and a B component; The preparation raw materials of the component A comprise, by weight, 10-30 parts of isocyanate modified MDI, 5-20 parts of polyether glycol, 15-35 parts of polymeric MDI, 30-45 parts of barium sulfate and 1-2 parts of a first auxiliary agent; The raw materials for preparing the component B comprise, by weight, 30-50 parts of polyether polyol, 10-20 parts of amino chain extender, 20-40 parts of barium sulfate, 5-10 parts of water scavenger, 2-5 parts of color paste, 0.5-2 parts of second auxiliary agent and 0.2-0.5 part of catalyst. In the prior art, a little filler is generally added into the B component of the polyurea coating, so that the density of the prepared polyurea coating is lower, and when the content of the filler in the B component is increased, the viscosity of the B component is too high due to the too high filler content, so that the preparation and subsequent construction of the polyurea coating are not facilitated. The A component and the B component of the polyurea coating provided by the application are added with the filler (barium sulfate) and are matched with a specific preparation process, so that the prepared polyurea coating has high density and good compactness, further the corrosion resistance of the coating is obviously improved, and the polyurea coating is suitable for various industrial heavy corrosion prevention fields, such as electrolysis, electroplating baths, chemical storage tanks, sulfur removal flues, chemical sewage tanks and the like. In the application, the isocyanate modified MDI is MDI50 which is a mixture containing MDI2, 4 isomer and MDI4, 4' isomer, and is colorless or light yellow transparent liquid at normal temperature. The MDI50 used in the present application is a commercially available product purchased from vandergar chemical