Solvent-free low-viscosity long-operation-time polyurethane floor material and preparation method thereof

Abstract

The invention relates to a solvent-free low-viscosity long-operation-time polyurethane floor material and a preparation method thereof. The solvent-free low-viscosity long-operation-time polyurethane floor material is prepared from a component A and a component B according to a weight part mixing ratio of (3-5): (1-1.5), the component A comprises castor oil modified polyol, a powder filler, a zeolite molecular sieve, a high-boiling-point plasticizer, a water removal agent, modified fumed silica, a thermosensitive catalyst and an auxiliary agent; and the component B comprises modified diphenyl methane diisocyanate (MDI), diphenyl methane diisocyanate (MDI)-50, an MDI mixture containing 2, 2 '-diphenyl methane diisocyanate, and a stabilizer. The polyurethane floor material disclosed by the invention has the advantages of no solvent, low viscosity, long operation time, high permeability, strong adhesive force and excellent mechanical property, can be used as a finishing coat and a primer, and is easy to produce and construct, and the defects that the existing polyurethane floor material is short in operation time, poor in permeability and relatively high in viscosity after no solvation are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane flooring, and in particular to a solvent-free, low-viscosity, long-operation-time polyurethane flooring material and a preparation method thereof. Background Art

[0002] With the transformation and upgrading of the manufacturing industry, the requirements of industrial sites for the ground are becoming more and more diverse, requiring both good decorative properties and environmental protection and anti-cracking properties. Compared with the commonly used epoxy floors on the market, polyurethane flooring has the characteristics of good toughness, strong chemical resistance, anti-cracking, and fast low-temperature curing, so polyurethane materials are more and more widely used in the field of flooring. Oily polyurethane materials often have high viscosity, need to add solvents or match diluents for construction, it is difficult to ensure that VOC meets the requirements, and it is impossible to construct in semi-enclosed or enclosed places with high environmental protection requirements. Water-based polyurethane flooring can already achieve extremely low V0C, but water-based polyurethane materials often have poor wear resistance, chemical resistance and brightness are not as good as oily materials, so the market has a greater demand for low-viscosity solvent-free oily polyurethane.

[0003] If the polyurethane material contains water, it will trigger a side reaction and cause bubbling. In order to avoid this phenomenon, the main paint component of the polyurethane floor material usually needs to remove the water contained in it by heating and vacuuming. For example, CN 114085350A discloses a sports field floor material and a preparation method thereof. Its main paint component needs to be vacuumed at 105°C for 2 hours to remove moisture. The vacuum heating method can effectively remove moisture, but the production process is relatively cumbersome, and the heating and cooling time greatly affects the production efficiency.

[0004] Primers require good sealing and permeability. Polyurethane materials have a large molecular weight and high viscosity, and it is difficult to penetrate into porous substrates to form a good sealing effect. Oily polyurethane primers usually require the addition of solvents to reduce viscosity and improve penetration performance. For example, CN 102533087 A discloses a polyurethane primer and a preparation method thereof, wherein component A contains 10 to 20 parts of a first solvent and 15 to 30 parts of a polyurethane-grade solvent. By adding solvents, the viscosity of the system is reduced and the penetration ability is improved. However, after adding solvents, VOC is difficult to meet the standards and cannot meet the increasingly stringent environmental protection requirements.

[0005] There are three isomers of MDI during the production process, namely 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'-diphenylmethane diisocyanate. Due to the steric hindrance, the activity of the NCO group at position 4 is higher than that at position 2, so the activity of 4,4'-diphenylmethane diisocyanate is higher than that of 2,4'-diphenylmethane diisocyanate, and the activity of 2,4'-diphenylmethane diisocyanate is higher than that of 2,2'-diphenylmethane diisocyanate. The operating time of polyurethane floor materials with MDI-type curing agents on the market is generally around 10 minutes, and quick on-site construction is required to ensure the defoaming effect and leveling properties of the material. In order to reduce the reactivity of polyurethane materials and increase the operating time, more 2,4'-diphenylmethane diisocyanate with low reactivity is usually introduced into the curing agent. In this way, the operating time can be increased to about 25 minutes, but it still cannot reach the 40-minute operating time of epoxy materials; and 2,2'-diphenylmethane diisocyanate with even lower reactivity is usually not used in curing agents because of incomplete reaction. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a solvent-free, low-viscosity, long-operation-time polyurethane floor material and a preparation method thereof. The polyurethane floor material prepared by the present invention has the advantages of being solvent-free, low-viscosity, long-operation-time, high permeability, strong adhesion and excellent mechanical properties. It can be used as both a topcoat and a primer, and has the advantages of being easy to produce and construct. It solves the defects of existing polyurethane floor materials such as short operation time, poor permeability and high viscosity after solvent-free.

[0007] To solve the above problems, the present invention is implemented through the following technical solutions:

[0008] The first invention object of the present invention is:

[0009] Provided is a solvent-free, low-viscosity, long-operation-time polyurethane floor material, which comprises component A and component B:

[0010] The mixing ratio of component A and component B by weight is: (3-5): (1-1.5);

[0011] Component A includes the following components in weight percentage:

[0012] Polyol resin 30-50%, powder filler 30-60%, zeolite molecular sieve 5-10%, high boiling point plasticizer 1-10%, dehydrating agent 1-5%, modified fumed silica 0.1-1%, thermosensitive catalyst 0.01-0.1%, auxiliary agent 2-5%, the sum of all components is 100%;

[0013] The auxiliary agents include dispersants, defoamers, leveling agents and bentonite;

[0014] Component B includes the following components in weight percentage:

[0015] Modified diphenylmethane diisocyanate MDI 30%-50%, diphenylmethane diisocyanate MDI-50 20%-30%, MDI mixture containing 2,2'-diphenylmethane diisocyanate 20%-40%, stabilizer 0.01%-0.5%, the sum of all components is 100%.

[0016] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0017] The polyol resin is castor oil modified polyol resin.

[0018] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0019] The castor oil modified polyol resin comprises castor oil modified polyol resin 1 and castor oil modified polyol resin 2;

[0020] The castor oil modified polyol resin 1 has a hydroxyl value of 210 to 350 mgKOH / g, a viscosity of 1000 to 5000 cp, and an acid value of less than 5 mgKOH / g;

[0021] The castor oil modified polyol resin 2 has a hydroxyl value of 150-220 mgKOH / g, a viscosity of 500-1500 cp, and an acid value of less than 5 mgKOH / g. Its lower viscosity gives the material good construction performance and permeability.

[0022] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0023] The modified diphenylmethane diisocyanate MDI in component B contains 30% to 50% of 4,4'-diphenylmethane diisocyanate, 10% to 50% of 2,4'-diphenylmethane diisocyanate, and 10% to 50% of polymethylene polyphenyl polyisocyanate, and the sum of all components is 100%;

[0024] The mass percentage content of 2,2'-diphenylmethane diisocyanate in the MDI mixture containing 2,2'-diphenylmethane diisocyanate in the component B is 20-30%;

[0025] The stabilizer in component B is benzoyl chloride, citric acid, and phosphoric acid inhibitor;

[0026] The modified diphenylmethane diisocyanate MDI in component B contains 30% to 50% of 4,4'-diphenylmethane diisocyanate, which reacts quickly with the hydroxyl group of the main paint, so that the mechanical properties of the material increase rapidly and it reaches solid drying quickly; it contains 10% to 50% of 2,4'-diphenylmethane diisocyanate, whose reaction activity is lower than that of 4,4'-diphenylmethane diisocyanate, providing a longer operating time for the material; it contains 10% to 50% of polymethylene polyphenyl polyisocyanate, which has a higher functionality and can improve the tensile strength and compressive strength of the material.

[0027] The content of 2,2'-diphenylmethane diisocyanate in the MDI mixture containing 2,2'-diphenylmethane diisocyanate in component B is 20-30%. 2,2'-diphenylmethane diisocyanate has a low reactivity, and its reaction time with the hydroxyl group in the main paint component is relatively long, so that the operating time of the present invention is extended; however, the reaction of 2,2'-diphenylmethane diisocyanate is usually incomplete, and it is easy to cause the mechanical properties to decrease and the paint film to dry for a long time after adding. Generally, 2,2'-diphenylmethane diisocyanate cannot be used in the floor curing agent. The present invention solves the problem of incomplete reaction by adding a heat-sensitive catalyst, and at the same time, by utilizing its heat-sensitive characteristics, the operating time is almost not shortened.

[0028] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0029] The viscosity of component B is 20-50cp, its functionality is 2.0-2.5, and its NCO content by mass is 32.0%-35.0%. The viscosity of polyurethane MDI curing agents on the market is generally 120-400cp. Its lower viscosity gives the present invention better defoaming and leveling properties, as well as permeability to the base surface and longer operating time.

[0030] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0031] The powder filler is one or a combination of refined BaSO4, silica powder, montmorillonite and talcum powder.

[0032] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0033] The dewatering agent is CUWR-WB50T produced by Guangzhou Yourun Synthetic Materials Co., Ltd., which can effectively eliminate trace moisture in the raw materials and also has an auxiliary defoaming function.

[0034] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0035] The zeolite molecular sieve is 3A, 4A or 5A type molecular sieve activated powder, preferably 4A type molecular sieve activated powder, which can effectively absorb trace moisture in the system.

[0036] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0037] The high boiling point plasticizer is one or a combination of methyl nylonate DBE, tributyl acetyl citrate ATBC, and environmentally friendly plasticizer DINCH. The high boiling point solvent is added to control the viscosity of the main paint, improve the system penetration ability, and prolong the gel time.

[0038] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0039] The modified fumed silica is siloxane-modified fumed silica, in which the siloxane structure can greatly improve the interlayer adhesion ability, so that the adhesion between the system and the cement base surface and the system interlayer is greatly improved.

[0040] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0041] The dispersant included in the auxiliary agent is a polycarboxylic acid dispersant, and the defoaming agent is a silicone defoaming agent.

[0042] A preferred example of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention is:

[0043] The heat-sensitive catalyst is a heat-sensitive polyurethane composite metal catalyst, and the activation temperature is 35-50°C.

[0044] When the temperature is lower than the activation temperature, its catalytic activity is very low; when it is higher than the activation temperature, its catalytic activity begins to appear. In the initial stage of material mixing, NCO in component B and OH in component A begin to react and continuously release heat. As the reaction proceeds, the system temperature continues to rise, but the catalytic effect does not appear before reaching its activation temperature, so the catalyst has little effect on the operation time. As the reaction proceeds to the later stage, when the system temperature reaches its activation temperature, the reaction will proceed rapidly, allowing the system to dry faster and achieve the expected mechanical properties. Component B of the present invention contains 2,2'-diphenylmethane diisocyanate, which is difficult to react completely. Under the action of the catalyst, it can quickly cross-link with the resin and fully participate in the reaction.

[0045] The second object of the present invention is:

[0046] Provided is a method for preparing the aforementioned solvent-free, low-viscosity, long-operation-time polyurethane floor material. The preparation method provided by the present invention has a very convenient production process, does not require heating and dehydration, and does not require prepolymerization of the curing agent component. The method comprises the following preparation steps:

[0047] Preparation of Component A:

[0048] a1: Add castor oil modified polyol resin 1, castor oil modified polyol resin 2, dispersant, defoamer and leveling agent into a mixing tank in proportion, and stir at a low speed of 300-400 rpm for 15 minutes;

[0049] a2: Add bentonite, modified fumed silica and powder filler in proportion, and stir at 1000-1500 rpm for 30 minutes;

[0050] a3: Heat the dehydrating agent to 55°C in advance, reduce the speed to 600-800rpm, add the thermosensitive catalyst, high boiling point plasticizer, zeolite molecular sieve and dehydrating agent in proportion, and stir for 15 minutes to obtain component A;

[0051] Preparation of component B:

[0052] Add modified diphenylmethane diisocyanate MDI, diphenylmethane diisocyanate MDI-50, a mixture of MDI containing 2,2'-diphenylmethane diisocyanate, and a stabilizer into a sealed stirring tank in proportion, and stir at 600-800 rpm for 15 minutes to obtain component B;

[0053] Component A and component B are mixed in proportion to obtain a solvent-free, low-viscosity, long-operation-time polyurethane floor material.

[0054] The solvent-free, low-viscosity, long-operation-time polyurethane floor material and the preparation method thereof of the present invention have the following advantages:

[0055] 1. The solvent-free, low-viscosity, long-operation-time polyurethane floor material provided by the present invention is highly environmentally friendly. No solvent is added to its component A, and VOC is less than 5g / L; at the same time, in the preferred embodiment, the polyol resins used in component A are all castor oil-modified polyol resins, which are prepared from renewable materials and meet the environmental protection requirements of sustainable development.

[0056] 2. The solvent-free, low-viscosity, and long-operation-time polyurethane floor material provided by the present invention has a lower viscosity than similar products on the market. The reason is that a high-boiling point plasticizer is added to component A of the present invention to lower the viscosity, and component B has a low functionality and a viscosity of less than 50cp. Therefore, the overall mixed viscosity is between 2000 and 3500cp, and it has excellent leveling and permeability and is easy to construct.

[0057] 3. The solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention has the aforementioned low viscosity and has excellent permeability, thus realizing the solvent-free polyurethane primer. The solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention can be used as a scraping layer after adding sand and gravel, and the material can also be used as a topcoat after adding color paste. At the same time, the siloxane-modified fumed silica in the main paint component provides good interlayer adhesion. Therefore, the present invention is a bottom-surface integrated material, and the entire coating system can be prepared with the material, which is convenient for large-scale production and stocking.

[0058] 4. The solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention eliminates trace moisture in the components by adding a dehydrating agent (such as CUWR-WB50T) and a zeolite molecular sieve, thereby avoiding bubbles generated by side reactions. After curing, the surface is smooth and bubble-free, and the appearance is beautiful.

[0059] 5. Component A in the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention does not require heating and vacuum dehydration, and component B does not require prepolymerization. Only simple physical mixing is required for production, which greatly improves production efficiency and reduces the energy consumed in the heating process. The production process is very convenient.

[0060] 6. The solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention has a very long operation time and a relatively fast actual drying time.

[0061] Usually, polyurethane floor curing agents on the market contain more 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate, as well as a very small amount of 2,2'-diphenylmethane diisocyanate, and their operable time is 10 to 25 minutes, requiring multiple construction personnel on site to quickly construct to ensure the leveling of the material. Component B of the present invention contains more low-activity 2,2'-diphenylmethane diisocyanate, and its speed of reaction with hydroxyl is slower than 2,4'-diphenylmethane diisocyanate, which can extend the operating time. However, the reaction of 2,2'-diphenylmethane diisocyanate with hydroxy resin is usually incomplete, which will reduce the physical properties of the system and extend the actual drying time. The present invention solves this problem by adding a heat-sensitive catalyst to component A, and by adjusting the ratio of various isomers of MDI in the curing agent, the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention can reach 40 minutes in operable time, and the actual drying time is less than 8 hours, and there is no need for multiple people to quickly construct, reducing labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of the specific base structure after coating of the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention. DETAILED DESCRIPTION

[0063] In order to make the application, technical scheme and advantages of the present invention more clear, the present invention is described in detail in conjunction with specific embodiments. It should be understood that the embodiments are only used to illustrate the present invention, but not to limit the protection scope of the present invention. All simple improvements to the preparation method of the present invention under the premise of the concept of the present invention belong to the protection scope of the present invention.

[0064] Embodiment A method for preparing a solvent-free, low-viscosity, long-operation-time polyurethane floor material

[0065] A method for preparing a solvent-free, low-viscosity, long-operation-time polyurethane floor material, comprising component A and component B:

[0066] The mixing ratio of component A and component B by weight is: (3-5): (1-1.5);

[0067] It comprises the following preparation steps:

[0068] Preparation of Component A:

[0069] a1: Add castor oil modified polyol resin 1, castor oil modified polyol resin 2, dispersant, defoamer, leveling agent into a mixing tank in proportion, and stir at a low speed of 300 rpm for 15 minutes;

[0070] a2: Add bentonite, modified fumed silica and powder filler in proportion and stir at 1200rpm for 30min;

[0071] a3: Heat the dehydrating agent to 55°C in advance, lower the speed to 600 rpm, add the thermosensitive catalyst, high boiling point plasticizer, zeolite molecular sieve and dehydrating agent in proportion, and stir for 15 minutes to obtain component A;

[0072] Preparation of component B:

[0073] Add modified diphenylmethane diisocyanate MDI, diphenylmethane diisocyanate MDI-50, and a mixture of MDI containing 2,2'-diphenylmethane diisocyanate into a sealed stirring tank according to a certain proportion, and stir at 600-800 rpm for 15 minutes to obtain component B;

[0074] Component A and component B are mixed in proportion to obtain a solvent-free, low-viscosity, long-operation-time polyurethane floor material.

[0075] Mix component A and component B according to weight ratio to obtain the primer layer material, add 30% medium sand to the mixture to obtain the scraping layer material, and add 3% color paste to the mixture to obtain the topcoat material. The primer dosage is 0.25Kg / m 2 , the amount of sand scraping layer is 2kg / m 2 , the surface layer dosage is 0.8Kg / m 2For details of the basic structure, see Figure 1 .

[0076] The composition table of each raw material in the embodiments and comparative examples (mass percentage):

[0077]

[0078] Among them, in the 1# experimental group:

[0079] Castor oil modified polyol resin 1 is PA-195 resin produced by Suzhou Jianxing Chemical Technology Co., Ltd., and its hydroxyl value is 221 mgKOH / g;

[0080] Castor oil modified polyol resin 2 is URIC H-368 resin produced by Ito Oil Co., Ltd. of Japan, and its hydroxyl value is 188.3 mgKOH / g;

[0081] The dispersant was VK.DP 2100 produced by Foshan Ward Polymer Materials Co., Ltd.;

[0082] The defoamer was VK.DF569 produced by Foshan Ward Polymer Materials Co., Ltd.;

[0083] The leveling agent is BYK 354;

[0084] The modified fumed silica was HB-139 produced by Hubei Huifu Nanomaterials Co., Ltd.;

[0085] The thermosensitive catalyst is NT CAT E-129 produced by Shanghai Xindian Chemical Materials Co., Ltd., and its activation temperature is 40°C;

[0086] The high boiling point plasticizer is BASF plasticizer Hexamoll DINCH;

[0087] The zeolite molecular sieve is JLH-04 molecular sieve activated powder produced by Luoyang Jianlong Micro-Nano New Materials Co., Ltd.

[0088] The water removal agent is CUWR-WB50T produced by Guangzhou Yourun Synthetic Materials Co., Ltd.

[0089] The modified MDI is SUP 2496 produced by Huntsman Polyurethane (China) Co., Ltd.

[0090] Among them, MDI-50 is the MDI-50 produced by Wanhua Chemical Group;

[0091] The MDI mixture containing 2,2'-diphenylmethane diisocyanate is produced by Shanghai Songtuo New Materials MM-25, which contains 20-30% of 2,2'-diphenylmethane diisocyanate.

[0092] The MM-25 isocyanate, MM-25 is a mixture of 4,4', 2,4' and 2,2'-methylene diisocyanate, in which the content of 2,4' isomer is higher, and it is a pure MDI with more isomer components. It has the following typical characteristics:

[0093] Flash point, ℃(PMCC)>100;

[0094] Viscosity, 25°C, cPs < 100;

[0095] Specific gravity, 25℃(g / cm 3 )1.22;

[0096] NCO% 33.5;

[0097] Appearance: colorless to light yellow liquid;

[0098] Advantages: high NCO content; no need for low temperature storage; liquid above 25 degrees. This raw material can be purchased directly from the manufacturer.

[0099] Among them, in the 2# experimental group:

[0100] The castor oil modified polyol resin 1 is URIC F-40 resin produced by Ito Oil Co., Ltd. of Japan, and its hydroxyl value is 236 mgKOH / g;

[0101] The castor oil modified polyol resin 2 is URIC F-60 resin produced by Ito Oil Co., Ltd. of Japan, and its hydroxyl value is 215 mgKOH / g;

[0102] The high boiling point plasticizer is ATBC produced by Jiangsu Anbosi Chemical Technology Co., Ltd.

[0103] The remaining additives, modified fumed silica, thermosensitive catalyst, dehydrating agent, and zeolite molecular sieve are the same as those in the experimental group #1 of Example 1.

[0104] Comparative Example 1:

[0105] Step 1: Preparation of Component A

[0106] Based on Example 1, the difference is:

[0107] In step a3 of Example 1, CUWR-WB50T was not added, and its trace components were replaced with powder fillers that had little effect on the performance and were added when the powder fillers were added. The rest was exactly the same as in Example 1.

[0108] Step 2: Prepare component B

[0109] Exactly the same as Example 1.

[0110] Comparative Example 2:

[0111] Step 1: Preparation of Component A

[0112] Based on Example 1, the difference is:

[0113] In step a3 of Example 1, no heat-sensitive catalyst is added, and its trace components are replaced by powder fillers that have little effect on the performance and are added when the powder fillers are added. The rest is exactly the same as in Example 1.

[0114] Step 2: Prepare component B

[0115] Exactly the same as Example 1.

[0116] Comparative Example 3:

[0117] Step 1: Preparation of Component A

[0118] Exactly the same as Example 1

[0119] Step 2: Prepare component B

[0120] The MDI mixture containing 2,2'-diphenylmethane diisocyanate added in the step of Example 1 was replaced with 24% of modified MDI, and the rest was completely the same as Example 1.

[0121] Performance Test:

[0122] Examples 1#, 2#, commercially available conventional solvent-free polyurethane self-leveling, solvent-containing epoxy self-leveling, and comparative examples were selected for testing. The test results are shown in the following table:

[0123]

[0124]

[0125] It can be seen from the above table:

[0126] It can be seen from Examples 1 and 2 that the solvent-free polyurethane material prepared by the technical solution of the present invention has lower viscosity, longer operation time, good adhesion and extremely low VOC. Polyurethane floor materials with different properties can be obtained by adjusting the proportions of various raw materials.

[0127] It can be seen from Example 1 and Comparative Example 1 that adding dehydrating agent CUWR-WB50T with zeolite molecular sieve can effectively control the water content of the system and achieve an overall bubble-free appearance. Using molecular sieve alone for degassing is not effective, with a large number of microbubbles on the surface. Poor surface effects usually require surface modification.

[0128] According to Example 1 and Comparative Example 2, the actual drying time of Example 1 is 7 hours, and the actual drying time of Comparative Example 2 is 15 hours. Adding a heat-sensitive catalyst can effectively speed up the actual drying speed and effectively solve the problem of incomplete reaction of 2,2'-diphenylmethane diisocyanate. Due to its heat-sensitive properties, it has little effect on the operation time.

[0129] It can be seen from Example 1 and Comparative Example 3 that 2,2'-diphenylmethane diisocyanate can effectively prolong the operable time and improve the elongation of the system. The addition of a heat-sensitive catalyst effectively solves the problem of long drying time and incomplete reaction of 2,2'-diphenylmethane diisocyanate.

[0130] It can be seen from the above table that the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention has lower viscosity and longer operation time than conventional solvent-free polyurethane self-leveling, and the actual drying time is equivalent to that of conventional polyurethane self-leveling. Therefore, the present invention has good construction performance, and its long operation time does not require rapid construction, which can reduce the investment of construction personnel and increase construction flexibility. Its shorter actual drying time ensures construction efficiency, and the next process can be carried out faster.

[0131] The solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention has a low mixed viscosity, can penetrate into the cement-based surface well, and has excellent adhesion to the cement-based surface. Therefore, it can be used not only as a surface layer but also as a primer. It is a solvent-free polyurethane floor material with a base and a surface integrated.

[0132] Compared with solvent-based epoxy self-leveling, the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention has extremely low VOC, almost no odor, and can meet higher environmental protection requirements; at the same time, compared with solvent-based epoxy self-leveling, the present invention has better mechanical properties and has certain elasticity, so it can reduce the generation of gaps and has good anti-cracking performance.

[0133] In summary, the solvent-free, low-viscosity, long-operation-time polyurethane floor material of the present invention has the outstanding characteristics of good construction performance, high environmental protection, multiple application scenarios, and good crack resistance.

[0134] To sum up, the above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the disclosed technical content are regarded as equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

[0135] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The experimental methods without specific conditions in the present invention are usually carried out under conventional conditions or conditions recommended by the manufacturer.

[0137] Unless otherwise stated, the various optimization technical solutions in the present invention can be combined with each other.

[0138] Unless otherwise indicated, percentages and parts are by weight.

[0139] Experimental methods without specific conditions specified in the instructions and examples are usually carried out under conventional conditions or conditions recommended by the manufacturers.

[0140] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method and material similar or equivalent to the described content can be applied to the method of the present invention.

Claims

1. A solvent-free, low-viscosity, long-operation-time polyurethane floor material, characterized by: It includes component A and component B: The mixing ratio of component A and component B by weight is: (3-5): (1-1.5); Component A includes the following components in weight percentage: Polyol resin 30-50%, powder filler 30-60%, zeolite molecular sieve 5-10%, high boiling point plasticizer 1-10%, dehydrating agent 1-5%, modified fumed silica 0.1-1%, thermosensitive catalyst 0.01-0.2%, auxiliary agent 2-5%, the sum of all components is 100%; The auxiliary agents include dispersants, defoamers, leveling agents and bentonite; Component B includes the following components in weight percentage: Modified diphenylmethane diisocyanate MDI 30%-50%, diphenylmethane diisocyanate MDI-50 20%-30%, MDI mixture containing 2,2'-diphenylmethane diisocyanate 20%-40%, stabilizer 0.01%-0.5%, the sum of all components is 100%.

2. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: The polyol resin is castor oil modified polyol resin.

3. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 2 is characterized in that: The castor oil modified polyol resin comprises castor oil modified polyol resin 1 and castor oil modified polyol resin 2; The castor oil modified polyol resin 1 has a hydroxyl value of 210 to 350 mgKOH / g and a viscosity of 1000 to 5000 cp; The castor oil modified polyol resin 2 has a hydroxyl value of 150-220 mgKOH / g and a viscosity of 500-1500 cp.

4. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: The modified diphenylmethane diisocyanate MDI in component B contains 30% to 50% of 4,4'-diphenylmethane diisocyanate, 10% to 50% of 2,4'-diphenylmethane diisocyanate, and 10% to 50% of polymethylene polyphenyl polyisocyanate, and the sum of all components is 100%; The mass percentage content of 2,2'-diphenylmethane diisocyanate in the MDI mixture containing 2,2'-diphenylmethane diisocyanate in the component B is 20-30%; The stabilizer in component B is benzoyl chloride, citric acid, and phosphoric acid inhibitor.

5. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: The viscosity of component B is 20-50 cp, its functionality is 2.0-2.5, and the mass percentage content of NCO is 32.0%-35.0%.

6. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: The powder filler is one or a combination of refined BaSO4, silica powder, montmorillonite and talcum powder.

7. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: The dewatering agent is CUWR-WB50T produced by Guangzhou Yourun Synthetic Materials Co., Ltd.

8. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: It includes one or more of the following characteristics: The zeolite molecular sieve is 3A, 4A or 5A type molecular sieve activated powder; The high boiling point plasticizer is one or a combination of methyl nylonate DBE, tributyl acetyl citrate ATBC, and environmentally friendly plasticizer DINCH; The modified fumed silica is siloxane-modified fumed silica.

9. The solvent-free, low-viscosity, long-operation-time polyurethane floor material according to claim 1, characterized in that: The heat-sensitive catalyst is a heat-sensitive polyurethane composite metal catalyst, and the activation temperature is 35-50°C.

10. A method for preparing a solvent-free, low-viscosity, long-operation-time polyurethane floor material according to any one of claims 1 to 9, characterized in that: It comprises the following preparation steps: Preparation of Component A: a1: Add castor oil modified polyol resin 1, castor oil modified polyol resin 2, dispersant, defoamer and leveling agent into a mixing tank in proportion, and stir at a low speed of 300-400 rpm for 15 minutes; a2: Add bentonite, modified fumed silica and powder filler in proportion, and stir at 1000-1500 rpm for 30 minutes; a3: Heat the dehydrating agent to 55°C in advance, reduce the speed to 600-800rpm, add the thermosensitive catalyst, high boiling point plasticizer, zeolite molecular sieve and dehydrating agent in proportion, and stir for 15 minutes to obtain component A; Preparation of component B: Add modified diphenylmethane diisocyanate MDI, diphenylmethane diisocyanate MDI-50, a mixture of MDI containing 2,2'-diphenylmethane diisocyanate, and a stabilizer into a sealed stirring tank in proportion, and stir at 600-800 rpm for 15 minutes to obtain component B; Component A and component B are mixed in proportion to obtain a solvent-free, low-viscosity, long-operation-time polyurethane floor material.

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