A non-yellowing cementitious pavement coating and method of use

Abstract

The application discloses a yellowing-resistant cement ground cover coating and a use method thereof. The ground cover coating comprises an isocyanate curing agent component and a resin component, wherein the isocyanate curing agent component is composed of an adduct prepared by reacting isophorone diisocyanate (IPDI) and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol, and an HDI polymer; and the resin component is a hydroxyl resin. The coating has the characteristics of yellowing resistance, excellent mechanical properties, rapid construction and quick use, and solves the problems of poor adhesion, easy falling-off and poor yellowing resistance of the current cement ground cover.

Description

Technical Field

[0001] This invention relates to the field of polyurethane flooring technology, specifically to a yellowing-resistant coating for cement-based flooring and its application method. Background Technology

[0002] Cement-based wear-resistant flooring materials are dry-mixed materials composed of silicate cement, wear-resistant aggregates, and appropriate additives. Compared with ordinary cement floors, cement-based wear-resistant flooring features high strength and excellent wear resistance; due to the addition of cement curing agents and wear-resistant aggregates, its wear resistance is several times that of cement floors. Because of its superior performance, it is increasingly used in highways, airport runways, warehouses, docks, supermarkets, and other places. However, cement-based wear-resistant materials also have disadvantages such as poor cleaning properties, easy penetration of stains, poor decorative properties, and dust generation, which hinders their promotion in food processing workshops, electronic cleanrooms, and other similar settings.

[0003] Traditional methods involve using epoxy flooring materials, but the dense surface of cement-based wear-resistant flooring can lead to peeling and a short lifespan. Furthermore, the paint color yellows under sunlight, reducing its aesthetic appeal. Additionally, epoxy resin materials have poor wear resistance, making them unsuitable for cleanrooms. Patent CN107892870A uses a mixture of HDI biuret and HDI monomers to synthesize a polyurethane topcoat. This two-component product has complex application steps, and its hardness is insufficient for cement-based wear-resistant flooring, resulting in only average wear resistance and lower product safety.

[0004] To address the shortcomings of current cement-based wear-resistant flooring materials in terms of adhesion, aesthetics, and durability, it is necessary to develop a coating for cement-based wear-resistant flooring that offers high aesthetics, high strength, and long service life. Summary of the Invention

[0005] The purpose of this invention is to provide a yellowing-resistant coating for cement-based flooring, applicable to the field of flooring materials. This cement-based wear-resistant flooring coating differs from traditional aliphatic isocyanate and polyol systems. This coating features yellowing resistance, high hardness, and high adhesion, overcoming the shortcomings of traditional materials such as easy peeling, short lifespan, and poor decorative properties.

[0006] Another object of the present invention is to provide a method of using this yellowing-resistant coating for cement flooring.

[0007] To solve the above technical problems, the present invention provides the following technical solution:

[0008] (1) Isocyanate curing agent components, including

[0009] a) IPDI adduct, which is prepared by reacting isophorone diisocyanate (IPDI) with 2,2,6,6-tetra(hydroxymethyl)cyclohexanol;

[0010] b) Optional HDI polymer;

[0011] (2) The resin component is a hydroxyl resin.

[0012] In some specific implementations, the method for preparing the IPDI adduct includes the following steps:

[0013] Under nitrogen protection and at temperatures ranging from 70 to 120°C (e.g., 70°C, 80°C, 90°C, 100°C, 110°C, 120°C), 2,2,6,6-tetra(hydroxymethyl)cyclohexanol is slowly added dropwise to IPDI. The NCO content is then monitored. The IPDI adduct is obtained once the NCO mass fraction reaches the theoretical value. There are no specific restrictions on the addition rate; for example, 10g of 2,2,6,6-tetra(hydroxymethyl)cyclohexanol can be slowly added to 120g of IPDI over 3 minutes. The theoretical endpoint is reached when the NCO mass fraction reaches 28%.

[0014] In some specific embodiments, the molar ratio of IPDI to 2,2,6,6-tetra(hydroxymethyl)cyclohexanol is 5:1 to 25:1; for example, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, etc., preferably 8:1 to 15:1.

[0015] In some specific implementations, the HDI polymer includes at least one of HDI dimer, HDI trimer, HDI pentamer, HDI heptamer, HDI nonamer, and HDI polymer; for example, it includes HDI trimer and other polymers. Preferably, the mass content of the trimer in the HDI polymer is 10-80%, such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc., more preferably 10-50%. More preferably, the viscosity of the HDI polymer at 25°C is 300-1200 mPa·s, such as 300 mPa·s, 400 mPa·s, 500 mPa·s, 600 mPa·s, 700 mPa·s, 800 mPa·s, 900 mPa·s, 1000 mPa·s, 1100 mPa·s, 1200 mPa·s, etc.

[0016] In some specific embodiments, the HDI polymer accounts for 0 to 50 wt% of the total mass of the isocyanate curing agent component, for example, 0, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, etc.; preferably 30 to 50 wt%.

[0017] In some specific embodiments, the resin component is selected from modified castor oil resin; preferably, it is selected from modified castor oil resins with a hydroxyl value of 200-400 mgKOH, such as 250 mgKOH, 300 mgKOH, 350 mgKOH, etc., a viscosity at 25°C of 750-1500 mPa·s, such as 800 mPa·s, 850 mPa·s, 900 mPa·s, 950 mPa·s, 1000 mPa·s, 1100 mPa·s, 1200 mPa·s, 1300 mPa·s, 1400 mPa·s, 1500 mPa·s, etc., and a functionality of 2.5-4.0, such as functionality of 2.5, 3, 3.5, 4. Examples of the modified castor oil resins of this invention include BASF 750 resin and Shanghai Jingri New Materials Co., Ltd.'s 4105 resin, but are not limited thereto.

[0018] Some specific implementations also include a solvent, the amount of which accounts for 0-40% of the total mass of the coating system, such as 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, etc., preferably 5-15%.

[0019] In some specific embodiments, the solvent is selected from at least one of mixed dicarboxylic acid dimethyl ester, propylene glycol methyl ether propionate, ethylene glycol diacetate, propylene glycol diacetate, butyl acetate, xylene, and ethyl acetate.

[0020] In some specific embodiments, the molar ratio of NCO in the isocyanate curing agent component to OH in the resin component is 1 to 2, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc. Preferably, the molar ratio of NCO to OH is 1.2 to 1.5.

[0021] Some specific implementations also include a wetting agent and a catalyst; preferably, the catalyst is selected from at least one of bismuth-based and tin-based catalysts, wherein bismuth-based and tin-based catalysts are common catalysts in the polyurethane field, such as dibutyltin dilaurate, etc. The amount of catalyst added accounts for 0 to 0.5% of the total mass of the coating system, for example 0, 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc., preferably 0.02% to 0.1%.

[0022] The wetting agent is selected from one or more wetting agents such as BYK333, BYK310, and ZY-2702. Preferably, the amount of the wetting agent added is 0 to 0.5% of the total mass of the coating system, for example, 0, 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc., preferably 0.2% to 0.5%.

[0023] In this invention, the total mass of the coating system refers to the total mass of all components, including the aforementioned isocyanate curing agent component, resin component, and optional solvent, optional catalyst, optional wetting agent, etc., which is well known to those skilled in the art.

[0024] On the other hand, the method of using the yellowing-resistant cement base floor coating includes the steps of mixing the isocyanate curing agent component and the resin component evenly and then applying the coating by brushing; preferably, any one of scraping, rolling, or spraying is used, with rolling or spraying being preferred.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] In this invention, an adduct of 2,2,6,6-tetra(hydroxymethyl)cyclohexanol and IPDI is introduced into the system. The robust cyclic structure of IPDI reacts with the five-hydroxyl cyclic compound to produce an IPDI adduct with high functionality. This adduct reacts with similarly functional hydroxyl resins (such as modified castor oil resin) and has short branches, resulting in a significant increase in film hardness and enhanced abrasion resistance and service life. Simultaneously, the high functionality brings more urethane groups that react with the resin, greatly improving the adhesion between the film and cementitious substrates. Unexpectedly, the introduction of the 2,2,6,6-tetra(hydroxymethyl)cyclohexanol compound significantly enhances the film's weather resistance, yellowing resistance, and organic acid resistance.

[0027] The yellowing-resistant cement-based wear-resistant floor coating of the present invention overcomes the shortcomings of traditional floor coatings, such as easy peeling and flaking, poor adhesion, and easy yellowing, and improves the mechanical properties and weather resistance of the paint film, making it very suitable for use as a topcoat on cement-based wear-resistant floors. Detailed Implementation

[0028] To more clearly describe the technical solution and beneficial effects of the present invention, the specific embodiments of the present invention will be further described below, but the present invention is not limited to the embodiments described below.

[0029] The main raw materials used in the embodiments of the present invention are as follows:

[0030] IPDI Wanhua Chemical;

[0031] HDI polymer, brand name HT-600 Wanhua Chemical;

[0032] IPDI trimer, brand name IP-170B, Wanhua Chemical;

[0033] 2,2,6,6-Tetra(hydroxymethyl)cyclohexanol Aladdin reagent;

[0034] Catalyst, dibutyltin dilaurate Aladdin reagent;

[0035] Resin, 750 BASF;

[0036] Resin, 4105 Shanghai Jingri New Materials Co., Ltd.;

[0037] Aladdin reagent for mixed dicarboxylic acid dimethyl ester.

[0038] Example 1

[0039] The isocyanate curing agent components consist of isophorone diisocyanate (IPDI) and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol in a molar ratio of 10:1, with IPDI comprising 54.5 parts by weight and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol comprising 5.5 parts by weight. After the reaction is completed at 90°C, 40 parts of HT-600 are added.

[0040] The resin components consist of 20 parts BASF 750 resin, 25.3 parts isocyanate, and 7.4 parts dimethyl dicarboxylate. 500 ppm dibutyltin dilaurate was added as a catalyst. The mixture was then sprayed onto a cement-based wear-resistant floor. The designation is A.

[0041] Example 2

[0042] The isocyanate curing agent components consist of isophorone diisocyanate (IPDI) and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol in a molar ratio of 16:1, with IPDI comprising 47.1 parts by weight and 2.9 parts by weight of 2,2,6,6-tetra(hydroxymethyl)cyclohexanol. After the reaction is completed at 80°C, 50 parts of HT-600 are added.

[0043] The resin components consist of 20 parts BASF 750 resin, 23.6 parts isocyanate, 1.3 parts dimethyl dicarboxylate, and 500 ppm dibutyltin dilaurate is added as a catalyst. The mixture is then sprayed onto a cement-based wear-resistant floor. This is designated as B.

[0044] Example 3

[0045] The isocyanate curing agent components consist of isophorone diisocyanate (IPDI) and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol in a molar ratio of 8:1, with IPDI comprising 61.3 parts by weight and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol comprising 7.7 parts by weight. After the reaction is completed at 120°C, 31 parts of HT-600 are added.

[0046] The resin components consist of 20 parts BASF 750 resin, 27 parts isocyanate, and 7.7 parts dimethyl dicarboxylate. 500 ppm dibutyltin dilaurate was added as a catalyst. The mixture was then sprayed onto a cement-based wear-resistant floor. The designation is C.

[0047] Example 4

[0048] The isocyanate curing agent components consist of isophorone diisocyanate (IPDI) and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol in a molar ratio of 23:1, with IPDI comprising 80.5 parts by weight and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol comprising 3.5 parts by weight. After the reaction is completed at 72°C, 16 parts of HT-600 are added.

[0049] A mixture of 20 parts of Shanghai Jingri 4105 resin, 20 parts of isocyanate, 17.1 parts of dimethyl dicarboxylate, and 500 ppm of dibutyltin dilaurate catalyst was sprayed onto a cement-based wear-resistant floor. The coating is designated as D.

[0050] Example 5

[0051] The isocyanate curing agent components consist of isophorone diisocyanate (IPDI) and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol in a molar ratio of 7:1, with IPDI comprising 87.5 parts by mass and 2,2,6,6-tetra(hydroxymethyl)cyclohexanol comprising 12.5 parts by mass. The reaction is terminated at 71°C.

[0052] The resin components consist of 20 parts of Shanghai Jingri 4105 resin, 29 parts of isocyanate, 18.1 parts of dimethyl dicarboxylate, and 500 ppm of dibutyltin dilaurate as a catalyst. The mixture is then sprayed onto a cement-based wear-resistant floor. The designation is D.

[0053] Comparative Example 1

[0054] The resin components consist of 20 parts of BASF 750 resin, 27.9 parts of HT-600 component, 7.8 parts of mixed dimethyl diacid, and 500 ppm of dibutyltin dilaurate catalyst. The mixture is then sprayed onto a cement-based wear-resistant floor.

[0055] Comparative Example 2

[0056] The isocyanate curing agent component is a mixture of 60 parts IT-170B and 40 parts HT-600.

[0057] The resin components consist of 20 parts of Shanghai Jingri 4105 resin, 38.3 parts of isocyanate, 9.5 parts of mixed dimethyl dicarboxylate, and 500 ppm of dibutyltin dilaurate as catalyst. The mixture is then sprayed onto a cement-based wear-resistant floor.

[0058] Test methods and results

[0059] Standard and yellowing resistance tests were conducted according to the national standard GB / T 22374-2018 Floor Coating Materials. Key indicators tested included pencil hardness, pot life, adhesion, abrasion resistance, water resistance (168 hours), alkali resistance (20% NaOH, 72 hours), acid resistance (10% sulfuric acid, 48 hours), oil resistance (120# solvent oil, 72 hours), and color difference after artificial aging (QUV, 600 hours). Shore D hardness was also tested using samples without solvents from the above examples and comparative examples.

[0060] Table 1 Results of routine tests on flooring

[0061]

[0062] As can be seen from Table 1, Examples A through E all exhibit good performance, especially in hardness and resistance to yellowing. The solution of this invention is highly suitable for cement-based floor covering materials, effectively ensuring both durability and aesthetics.

[0063] The above-described embodiments are preferred embodiments of the present invention. However, the present invention includes, but is not limited to, the limitations of the above embodiments. Those skilled in the art should understand that any changes, modifications, substitutions, combinations, or simplifications made by those skilled in the art after reading this application specification without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A coating for yellowing-resistant cement floor coverings, characterized in that, Includes the following components: (1) Isocyanate curing agent component, including a) IPDI adduct, which is prepared by reacting isophorone diisocyanate (IPDI) with 2,2,6,6-tetra(hydroxymethyl)cyclohexanol; b) Optional HDI polymer; (2) The resin component is a hydroxyl resin, selected from modified castor oil resin.

2. The yellowing-resistant coating for cement-based floor coverings according to claim 1, characterized in that, The method for preparing the IPDI adduct includes the following steps: Under nitrogen protection and at a temperature of 70-120℃, 2,2,6,6-tetra(hydroxymethyl)cyclohexanol was slowly added dropwise to IPDI. The NCO content was then monitored, and the IPDI adduct was obtained when the mass fraction of NCO reached the theoretical value.

3. The yellowing-resistant coating for cement-based floor coverings according to claim 1 or 2, characterized in that, The molar ratio of IPDI to 2,2,6,6-tetra(hydroxymethyl)cyclohexanol is 5:1 to 25:

1.

4. The yellowing-resistant coating for cement-based floor coverings according to claim 3, characterized in that, The molar ratio of IPDI to 2,2,6,6-tetra(hydroxymethyl)cyclohexanol is 8:1 to 15:

1.

5. The yellowing-resistant coating for cement-based floor coverings according to claim 1, characterized in that, The HDI polymer includes at least one of HDI dimer, HDI trimer, HDI pentamer, HDI heptamer, and HDI nonamer; and / or The HDI polymer accounts for 0 to 50 wt% of the total mass of the isocyanate curing agent component.

6. The yellowing-resistant coating for cement-based floor coverings according to claim 5, characterized in that, The HDI polymer contains 10-80% trimer by mass; and / or The HDI polymer accounts for 30-50 wt% of the total mass of the isocyanate curing agent components.

7. The yellowing-resistant coating for cement-based floor coverings according to claim 6, characterized in that, The mass content of trimer in the HDI polymer is 10-50%.

8. The yellowing-resistant coating for cement-based floor coverings according to claim 6, characterized in that, The viscosity of the HDI polymer at 25°C is 300~1200 mPa·s.

9. The yellowing-resistant coating for cement-based floor coverings according to claim 1, characterized in that, The resin component is selected from modified castor oil resin with a hydroxyl value of 200~400mgKOH, a viscosity of 750~1500mPa·s at 25℃, and a functionality of 2.5~4.

0.

10. The yellowing-resistant coating for cement-based floor coverings according to claim 1, characterized in that, It also includes solvents, with the amount of solvents accounting for 0 to 40% of the total mass of the coating system.

11. The yellowing-resistant coating for cement-based floor coverings according to claim 10, characterized in that, The amount of solvent added accounts for 5-15% of the total mass of the coating system.

12. The yellowing-resistant coating for cement-based floor coverings according to claim 10, characterized in that, The solvent is selected from at least one of the following: mixed dicarboxylic acid dimethyl ester, propylene glycol methyl ether propionate, ethylene glycol diacetate, propylene glycol diacetate, butyl acetate, xylene, and ethyl acetate.

13. The yellowing-resistant coating for cement-based floor coverings according to claim 1, characterized in that, The molar ratio of NCO in the isocyanate curing agent component to OH in the resin component is 1~2.

14. The yellowing-resistant coating for cement-based floor coverings according to claim 13, characterized in that, The molar ratio of NCO in the isocyanate curing agent component to OH in the resin component is 1.2 to 1.

5.

15. The yellowing-resistant coating for cement-based floor coverings according to claim 1 or 10, characterized in that, It also includes wetting agents and catalysts.

16. The yellowing-resistant coating for cement-based floor coverings according to claim 15, characterized in that, The catalyst is selected from at least one of bismuth-based and tin-based catalysts, and the amount of catalyst added is 0-0.5% of the total mass of the coating system; and / or The wetting agent is selected from one or more of BYK333, BYK310, and ZY-2702, and the amount of the wetting agent added is 0 to 0.5% of the total mass of the coating system.

17. The yellowing-resistant coating for cement-based floor coverings according to claim 16, characterized in that, The catalyst is added at a rate of 0.02% to 0.1% of the total mass of the coating system; and / or The amount of wetting agent added is 0.2% to 0.5% of the total mass of the coating system.

18. The method of using the yellowing-resistant coating for cement-based flooring as described in any one of claims 1 to 17, characterized in that, The process includes the steps of uniformly mixing the isocyanate curing agent component and the resin component, and then applying the mixture by brushing.

19. The method of use according to claim 18, characterized in that, Use any one of the following methods: scraping, rolling, or spraying.

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