CN107793903B - Coating composition for repairing rubber floor cloth and application thereof - Google Patents

Abstract

The application provides a coating composition for repairing rubber floor cloth and application thereof, the coating comprises a one-component polyurethane primer and a two-component polyurethane varnish; the one-component polyurethane primer comprises: 20-40% Self-crosslinking polyurethane resin; 10-20% hydroxy acrylic resin; 10-20% titanium dioxide; 5-10% functional filler; 10-15% solvent; 0-15% auxiliary; color paste; two-component polyurethane Varnishes include elastomeric polyurethane resins, hydroxyacrylic dispersions, and isocyanate curing agents. The coating system of the invention has good overall flexibility, excellent outer surface wear resistance and aging resistance, good interlayer adhesion and good compatibility with rubber floor cloth. The application of the coating composition to repair the rubber floor cloth achieves the effect of apparent renovation, and avoids the expansion of the dismantling process of the maintenance vehicle caused by the replacement of the floor cloth, the prolongation of the maintenance period and the waste caused by the replacement of the floor cloth.

Description

A kind of coating composition for repairing rubber floor cloth and its application

technical field

The invention relates to the technical field of rubber floor coverings, in particular to a coating composition for repairing rubber floor coverings and applications thereof.

Background technique

With the development of railway passenger cars and the application of new materials, higher requirements have been put forward for railway passenger car floor coverings in terms of internal performance, appearance, color, pattern, comfort, and durability. Among them, compared with the traditional polyvinyl chloride (PVC) plastic floor, the rubber floor cloth has the characteristics of good integrity, elasticity and comfort, and superior wear resistance, which can meet the needs of the development of railway passenger cars.

The rubber floor is made by adding various compounding agents to the rubber and processing it through mixing and other processes. According to the operating state of railway passenger cars, the rubber floor cloth in the car will form scratches, aging and discoloration, loss of gloss, and even damage pits, etc., which seriously affects the visual effect of passengers. In particular, official vehicles have high requirements on the decorative effect of the interior of the vehicle, and maintenance is required for each factory repair and segment repair. In the past, it was generally repaired by cutting and replacing the rubber floor cloth, but this would cause a color difference between the old and new floor cloth, and the parts and wall panels in the car need to be removed due to replacement, which increases the maintenance workload and maintenance cycle. Due to the replacement, it will cause a larger maintenance content, and it will also cause a waste of floor cloth materials.

SUMMARY OF THE INVENTION

In view of this, the present application provides a coating composition for repairing a rubber floor cloth and its application. The application of the coating composition provided by the present invention can quickly and conveniently repair the rubber floor cloth, achieve the effect of apparent renovation, and avoid Waste of floor cloth material.

The invention provides a coating composition for repairing rubber floor cloth, comprising a one-component polyurethane primer and a two-component polyurethane varnish;

The one-component polyurethane primer comprises: 20-40wt% of self-crosslinking polyurethane resin; 10-20wt% of hydroxyl acrylic resin; 10-20wt% of titanium dioxide; 5-10wt% of functional filler; 15wt% solvent; 0-15wt% auxiliary agent; and toning paste;

The two-component polyurethane varnish includes: elastic polyurethane resin, hydroxyacrylic acid dispersion and isocyanate curing agent.

Preferably, the average particle size of the functional filler is 0.01-1 micron; the functional filler can be selected from one or more of talc, calcium carbonate, barium sulfate, silica and alumina.

Preferably, the solvent is selected from one or more of aromatic hydrocarbon solvents, ketone solvents and ester solvents.

Preferably, the auxiliary agent is selected from one or more of dispersing agent, leveling agent, defoaming agent, anti-settling agent, ultraviolet light absorbing agent, light stabilizer, color floating prevention agent, sag prevention agent .

Preferably, the auxiliary agent comprises: 0.6-1.2wt% dispersant; 0.5-2wt% carbon black; 0.2-0.5wt% leveling agent; 0.1-0.3wt% defoamer; 0.3-0.5wt% % of anti-settling agent; 0.5-1.5 wt % of ultraviolet light absorber; 0.5-1.5 wt % of light stabilizer.

Preferably, in the two-component polyurethane varnish, the amount of the isocyanate curing agent is such that the molar ratio of hydroxyl groups to isocyanate groups is 1.05/1 to 1.3/1.

Preferably, the two-component polyurethane varnish further includes an inorganic filler, and the inorganic filler is selected from one or more of alumina and silica.

The present invention provides a method for repairing rubber floor coverings, comprising the following steps:

Use one-component polyurethane primer to coat and dry the rubber floor cloth to be repaired;

After the drying, two-component polyurethane varnish is used to coat the constructed rubber floor cloth again, and then dry to obtain the repaired rubber floor cloth;

The one-component polyurethane primer comprises: 20-40wt% of self-crosslinking polyurethane resin; 10-20wt% of hydroxyl acrylic resin; 10-20wt% of titanium dioxide; 5-10wt% of functional filler; 15wt% solvent; 0-15wt% auxiliary agent; and toning paste;

The two-component polyurethane varnish includes: elastic polyurethane resin, hydroxyacrylic acid dispersion and isocyanate curing agent.

Preferably, the dosage of the one-component polyurethane primer is 150-200 g/m ² ; the dosage of the two-component polyurethane varnish is 100-150 g/m ² .

Preferably, the one-component polyurethane primer and the two-component polyurethane varnish are independently dried in an environment of not lower than 15° C. for more than 9 hours.

The coating composition provided by the invention comprises: a one-component polyurethane primer and a two-component polyurethane varnish. Correspondingly, the coating system involved in the present invention is divided into a primer layer and a varnish layer, and each coating with good flexibility is selected to form an elastic coating system, and the deformation buffer rubber floor cloth that can be recovered by the system is used in the process of use. The deformation and stress make it form a whole with basically the same elastic modulus, so as to repair the rubber floor covering. The coating system involved in the invention has good overall flexibility, excellent outer surface wear resistance, excellent aging resistance, good interlayer adhesion and good compatibility with rubber floor cloth, wherein the coating system is resistant to The aging performance can reach 3000h, far exceeding the 1000h of conventional coatings. The coating composition provided by the present invention is used to repair the rubber floor cloth. The construction process involved in the present invention is simple, mature and feasible. On the basis of the original floor cloth, the elastic coating is brushed to achieve the effect of apparent renovation, avoiding the need for Expansion of the dismantling process of the maintenance vehicle caused by the replacement of the floor cloth, prolongation of the maintenance cycle, and waste caused by the replacement of the floor cloth. Through the application of the technology, the present invention can quickly and conveniently satisfy the repair of the rubber floor covering for the maintenance of the official vehicle.

Description of drawings

Fig. 1 is the schematic diagram of the film forming process of water-based one-component polyurethane paint in the embodiment of the present invention;

Fig. 2 is the production process schematic diagram of primer or varnish of the embodiment of the present invention;

Fig. 3 is the schematic diagram of the two-component water-based polyurethane film forming process in the embodiment of the present invention;

Fig. 4 is the protection situation of the non-painted part in the embodiment of the present invention;

Fig. 5 is the protection situation of the joint of the floor cloth in the embodiment of the present invention;

Fig. 6 is the grinding state after grinding and polishing sheet state and primer drying in the embodiment;

Fig. 7 is the effect state after varnish construction in the embodiment;

Fig. 8 is the physical contrast situation before and after painting in the embodiment;

Fig. 9 is the test result situation of the folding mode in the embodiment;

FIG. 10 is the test result of hammering method in the embodiment.

Detailed ways

The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The invention provides a coating composition for repairing rubber floor cloth, comprising a single-component polyurethane primer and a two-component polyurethane varnish;

The one-component polyurethane primer comprises: 20-40wt% of self-crosslinking polyurethane resin; 10-20wt% of hydroxyl acrylic resin; 10-20wt% of titanium dioxide; 5-10wt% of functional filler; 15wt% solvent; 0-15wt% auxiliary agent; and toning paste;

The two-component polyurethane varnish includes: elastic polyurethane resin, hydroxyacrylic acid dispersion and isocyanate curing agent.

The present invention forms an elastic coating system with excellent interlayer adhesion by selecting an elastic coating paint with better flexibility, which can be used for the repair of rubber floor cloth, and can quickly and conveniently achieve the effect of apparent renovation.

The coating composition provided by the present invention includes a one-component polyurethane primer, which forms an undercoat. The one-component polyurethane primer includes a self-crosslinking polyurethane resin; the usual polyurethane film-forming mechanism and film-forming process include: filling process: solvent volatilization, particles approaching each other to achieve a dense filling state; fusion process: particle surface layer Destruction, the particles contact each other; diffusion process: the molecular chains between the dispersion particles diffuse each other to form a homogeneous film with certain mechanical properties; the film-forming ability of the dispersion and the particle shear modulus of the dispersion and the particle size of the dispersion inversely proportional.

The present invention preferably adopts a water-based one-component polyurethane primer, and its film-forming process is shown in Figure 1, which is a schematic diagram of the film-forming process of the water-based one-component polyurethane paint in the embodiment of the present invention. In Figure 1, the first part is: there is water on the substrate and the latex particles dispersed in it, and the water volatilizes; the second part is: the water evaporates, and the latex particles are close to each other, forming a tightly packed state; the third part is: the water Further evaporation, condensation to form a hexagonal structure, mainly physical film formation; the fourth part is: further condensation, the latex particles begin to react, this time including physical film formation and oxidation drying film formation; the fifth part: on the surface of the substrate A homogeneous, complete coating film is formed.

The one-component polyurethane primer of the present invention is prepared by mixing high-performance self-crosslinking polyurethane resin, pigments, auxiliary agents, etc. in a certain proportion. Specifically, the one-component polyurethane primer comprises: 20-40wt% of self-crosslinking polyurethane resin; 10-20wt% of hydroxy acrylic resin; 10-20wt% of titanium dioxide; 5-10wt% of functional filler 10-15wt% solvent; 0-15wt% auxiliary agent; and toning paste.

The one-component polyurethane primer preferably includes 25-35 wt% of a self-crosslinking polyurethane resin; wherein, the self-crosslinking means that after the polyurethane film is formed, it can automatically carry out a chemical reaction to achieve crosslinking and improve the coating film. The degree of crosslinking improves the film properties. In the embodiment of the present invention, drying oil fatty acid and polyalkoxy silicon unit are introduced into the self-crosslinking polyurethane resin; μm) range. Preferably, the self-crosslinking polyurethane resin can undergo auto-oxidative crosslinking and hydrolytic condensation reactions to form a crosslinked network after film formation; such a polyurethane coating can be made into a paint film with excellent hand feel. In addition, the advantages of the one-component polyurethane coating of the present invention are that the construction is convenient, and there is no danger of gelation in storage.

The one-component polyurethane primer of the invention is self-crosslinking and drying to form a film at room temperature, which is non-toxic, harmless, and environmentally friendly. Also, the present invention preferably uses water as a diluent, low VOC, and low odor. The one-component polyurethane primer has excellent adhesion, good elasticity and covering power, and is widely used in the decoration and protection of floors with high decorative requirements in the industrial field.

In the one-component polyurethane primer of the present invention, the main film-forming material is high-performance self-crosslinking polyurethane resin. Polyurethane resin is formed by the reaction of polyisocyanate and polyol containing active hydrogen atoms and groups. In actual production, diisocyanate is commonly used, and its structure is: O=C=N-R-N=C=O.

Among them, NCO is called isocyanate group or isocyanate group. The process of reacting diisocyanate and polyol to form high polymer is neither condensation nor polymerization, but between the two, which is called stepwise polymerization. The active hydrogen atoms in one molecule are transferred to another molecule. No by-products are separated out during the curing process, and the volume shrinkage is small.

The characteristics of the polyurethane resin paint of the present invention include: (1) strong wear resistance, and is widely used as floor paint, deck paint and the like. (2) It has both good protection and good decoration. (3) It has strong adhesion to various substances. (4) The elasticity of the paint film can be adjusted as required: it can be adjusted from a very hard coating to a flexible elastic coating. (5) It has comprehensive chemical resistance, acid, alkali and salt resistance, and is suitable for chemical anti-corrosion coatings. (6) It can be dried at high temperature and cured at low temperature, such as 0 °C; (7) It can be made into low temperature (-40 °C) varieties and high temperature resistant varieties. (8) Automatic tinning in molten solder. (9) It can be combined with polyester, polyether, epoxy, alkyd, polyacrylate, vinyl chloride vinyl acetate copolymer resin, coal tar, drying oil, etc. wide.

In the primer coating of some embodiments of the present invention, a room temperature drying elastic polyurethane resin is selected to ensure strong permeability and adhesion to the surface of the substrate on the basis of reducing drying energy consumption. At the same time, the present invention uses the flexible resin as the auxiliary film-forming material, so that the paint film has good flexibility and elasticity. Therefore, the one-component polyurethane primer includes 10-20 wt% of hydroxy acrylic resin, which is an auxiliary film former.

The one-component polyurethane primer of the invention has self-leveling performance on various substrates, so that the paint film has excellent covering ability. Using an excellent curing system, the paint film is quickly cross-linked and cured. After curing, the paint film is non-toxic and has no irritating odor; the construction time is short, and the process requirements are simple; it is suitable for floor protection used in various environments and has strong tolerance.

In addition to the above film-forming substances, the one-component polyurethane primer also includes pigments and fillers. Among them, several main factors affecting the performance of pigments include: 1) The size of pigment particles: the average particle size of most pigments is 0.01-1.0 μm, but the average particle size of extender pigments is 50 μm. The particle size is small, the dispersion is large, the area of reflected light is large, and the covering power is strong; the particle size is small, the tinting power is strong. 2), the shape of the particles: tumor-like particles, titanium dioxide, lithopone with good fluidity. Needle-shaped particles, zinc white, talcum powder, have a strengthening effect, improve hardness and strength. Flat particles, such as metallic pigments, enhance the barrier effect. 3) The specific surface area of pigment particles: the surface area of the pigment per unit mass is called the specific surface area, which is inversely proportional to the particle size. The specific surface area is large, and the covering power and tinting power are good. 4) Surface treatment of pigment particles: the presence of surfactants can control processes such as supersaturation, solubilization, and nucleation. There is an organic coating on the surface of the inorganic pigment (that is, it is wrapped by a surfactant), which can improve the wetting effect, increase the dispersion and stability of the pigment, and change the leveling of the coating. Its light resistance, acid and alkali resistance and solvent resistance can be improved by surfactant treatment.

In order to meet the filling, easy grinding, elasticity and other properties of the polyurethane primer, improve the application performance and mechanical properties of the coating, and reduce the cost, after a lot of work from theory to practice, the present invention adopts a certain ratio of titanium dioxide and functional fillers. , This color and filler meet the technical requirements. That is, the one-component polyurethane primer comprises: 10-20wt% of titanium dioxide and 5-10wt% of functional filler. In the embodiment of the present invention, the functional filler can be selected from one or more of talc, calcium carbonate, barium sulfate, silica and alumina, such as silica-alumina-based hollow microspheres. In addition, pigments and fillers such as coloring pigments can also be used. In the embodiments of the present invention, ultrafine functional fillers are preferably used, and the average particle size thereof may be 0.01-1 μm.

In the present invention, the one-component polyurethane primer includes 10-15 wt % of solvent. Solvents are an important part of solvent-borne coating formulations, not only for dissolving resins, reducing viscosity to improve processability and application performance, but also affecting coating adhesion, corrosion resistance, outdoor durability, and film appearance. Therefore, the performance of one or several aspects of the coating can be improved by the selection of the solvent.

In the production of coatings, not only the resin is required to be dissolved in the solvent, but also the lower the viscosity of the resin solution with the same solid content, the better. In this way, when the same construction viscosity is achieved, the solid content of the paint liquid is higher, which can improve the construction efficiency, while the amount of solvent volatilized into the atmosphere is small, and the paint liquid has a fast drying speed.

The volatilization rate of the solvent is an important factor affecting the quality of the coating film. If the solvent evaporates too fast, the coating film will neither level nor fully wet the substrate, so it cannot produce good adhesion; Slow, not only does it take a long time to cure, but the coating film will sag or run and affect the quality of the application. After repeated tests, as a preference, one or more of aromatic hydrocarbons, ketones and esters with mild taste, good solubility and good construction effect are selected as the solvent for the polyurethane primer in the present invention; the present invention is more preferably A mixed solvent, for example, xylene:butyl acetate:propylene glycol methyl ether acetate=3:2:2 (volume ratio) is used.

The one-component polyurethane primer of the present invention includes 0-15 wt% of an auxiliary agent; the invention preferably adopts an auxiliary agent to further improve the performance and processing performance of the paint film, or does not need to use an auxiliary agent.

On the one hand, the auxiliary agent is an additive used to help eliminate the defects such as orange peel, floating color and blooming, air bubbles, shrinkage cavities, pinholes, and sagging that often appear on the surface of the coating film, including leveling agents, floating color and blooming prevention. agent, defoamer, sag inhibitor, etc. On the other hand, the auxiliary agent may also include additives such as dispersant, anti-settling agent, ultraviolet light absorber, light stabilizer, and drier. In the present invention, the auxiliary agent is preferably selected from a dispersing agent, a leveling agent, an antifoaming agent, an anti-settling agent, an ultraviolet light absorbing agent, a light stabilizer, a color-floating flower preventing agent and a sag preventing agent or more.

In the present invention, there is no particular limitation on the specific types of the above-mentioned auxiliary agents, and the conventional ones in the art can be used. Exemplarily, the leveling agent may be selected from acrylic leveling agents or silicone leveling agents, such as leveling agent OL-17 from Bayer, Germany, and the like. The defoaming agent can be a silicon-based defoaming agent, such as the defoaming agents BYK-065 and BYK-066N from BYK, Germany. The dispersant is preferably a dispersant BYK--110; the anti-settling agent is such as BYK-410 and the like. Specifically, the adjuvant of the present invention preferably includes: 0.6-1.2wt% of dispersant; 0.5-2wt% of carbon black; 0.2-0.5wt% of leveling agent; 0.1-0.3wt% of defoamer; 0.3 ～0.5wt% of anti-settling agent; 0.5～1.5wt% of ultraviolet light absorber; 0.5～1.5wt% of light stabilizer. The present invention may also include 0.01-0.02wt% of a polyurethane coating drier, and conventional products may be used. Among them, the carbon black can play the role of adjusting the color, and belongs to the pigment auxiliary. In addition, the base paint of the present invention also includes an appropriate amount of toner to adjust the color appropriately.

In the embodiment of the present invention, the production process of the one-component polyurethane primer is shown in FIG. 2, which is a schematic diagram of the production process flow of the primer or varnish in the embodiment of the present invention. In Fig. 2, in the embodiment of the present invention, raw materials such as resin, pigments and fillers, solvents and auxiliary agents are premixed, ground and painted under stirring, and then resin, solvent and auxiliary agent are added to adjust paint, after filtration, a On the one hand, the product is detected, and on the other hand, waste disposal is carried out.

The performance indicators of the polyurethane primer products obtained in the embodiment of the present invention are as follows: jujube red viscous liquid; outflow time≥20s, surface dry time≤2h, solid dry time≤24h; bending properties of the obtained paint film≤1mm, cross-cut test results ≤ grade 1, impact resistance ≥ 50cm.

The coating system of the present invention is divided into a primer layer and a varnish layer, wherein the two-component polyurethane varnish included in the coating composition of the present invention forms the varnish layer. The two-component polyurethane varnish is an elastic floor varnish, which includes an elastic polyurethane resin, a hydroxyacrylic acid dispersion and an isocyanate curing agent. The film-forming and cross-linking mechanism of the two-component polyurethane elastic floor varnish coating is as follows:

The film-forming mechanism of two-component polyurethane is very different from that of general polymer emulsions such as acrylic emulsions, and it is also not exactly the same as that of solvent-based polyurethanes. Generally, the solidification and film formation of the emulsion is a single physical process. The glass transition temperature of the dispersed phase particles is low. After the solvent is volatilized, a tightly packed structure is formed, and the film is condensed under the action of capillary pressure. In the solvent-based polyurethane system, both the hydroxyl-containing resin and the curing agent are dissolved in the organic solvent in the form of molecules, the formed system is homogeneous, and the curing reaction is carried out between the molecules, so the curing reaction is relatively complete, and the formed The coating film is also homogeneous.

In the embodiments of the present invention, the two-component polyurethane forms a multiphase film. First, when most of the water evaporates, the emulsion particles contact each other to form a tightly packed structure, and the residual water and curing agent molecules are located in the gaps between the emulsion particles. As the water evaporates further, the emulsion particles begin to coagulate, forming a tighter hexagonal arrangement. At the same time, the curing agent molecules diffuse to the interface and the interior of the emulsion particles, and a cross-linking curing reaction occurs.

The present invention preferably adopts water-based two-component polyurethane varnish, and its film-forming mechanism is shown in Figure 3, which is a schematic diagram of the two-component water-based polyurethane film-forming process in the embodiment of the present invention. In Figure 3, the first part is: there is water and curing agent on the substrate, and the latex particles dispersed in it, and the water volatilizes; the second part is: the water evaporates, and the latex particles are close to each other, forming a tightly packed state; the third part is Yes: the water is further evaporated and condensed to form a hexagonal structure, which is mainly physical film formation; the fourth part is: further coagulation, the latex particles and the curing agent begin to react, which is mainly chemical film formation; the fifth part is: in the base A homogeneous and fully cured coating film is formed on the surface of the material.

The chemical reaction of the two-component polyurethane coating is more complicated. In addition to the chemical reaction of -OH and -NCO, other chemical reactions also occur, such as:

(1) react with alcohol compounds, and the generation product is carbamate:

(2) isocyanate reacts with amine to generate urea:

(3) isocyanate reacts with urea to generate biuret:

(4) Isocyanate reacts with water:

Reaction rate: amine>alcohol/water>acid, since the reaction of R- _NH2 and R-NCO is faster than that of water, the above reaction can be written as:

R-NCO+R′-NCO+H ₂ O→RHNCONHR′+CO ₂ (5);

(5) isocyanate reacts with urethane to generate allophanate:

(6) isocyanate reacts with acid:

In the embodiment of the present invention, the film-forming mechanism of the aqueous two-component polyurethane is related to the particle coagulation mechanism of the thermoplastic polymer dispersion and the film-forming mechanism of the cross-linking reaction of the thermosetting polymer solution. In the film-forming process, there are the following processes: ① the volatilization of volatile matter (solvent, water); ② the co-coagulation of polyol and polyisocyanate particles; ③ the reaction of polyisocyanate and water; ④ the reaction of polyol and polyisocyanate.

The polyurethane elastic floor varnish of the present invention is prepared by mixing a hydroxyacrylic acid dispersion and an isocyanate curing agent in a certain proportion. Specifically, the polyurethane floor varnish is prepared by cold mixing of hydroxyacrylic acid dispersion and elastic polyurethane, and the flexible water-based isocyanate curing agent is mixed in a certain proportion, and the paint film has certain elasticity and high wear resistance.

The two-component polyurethane varnish is a two-component special coating with polyurethane as the base material, which is suitable for the anti-corrosion protection of temperature resistance, burning resistance, solvent resistance, abrasion resistance and mildew resistance of various materials. Chemical resistance, can withstand immersion in chemicals such as cleaning agents, engine oil, and kerosene for a long time. The two-component polyurethane varnish includes a hydroxyacrylic acid dispersion; the present invention uses a flexible resin as an auxiliary film-forming material, and the paint film has good flexibility, elasticity, wear resistance and moderate anti-skid coefficient. The product has self-leveling properties on various substrates, giving the paint film excellent hiding power. The invention adopts an excellent curing system, the paint film is rapidly cross-linked and cured, the cured paint film is non-toxic and has no irritating odor; the construction time is short, the process requirements are simple, and it is suitable for floor protection used in various environments and has strong weather resistance.

The two-component polyurethane varnish of the invention is non-toxic, harmless, and environmentally friendly. Also, the present invention preferably uses water as a diluent, low VOC, and low odor. The two-component polyurethane varnish has excellent adhesion, excellent flexibility, and excellent water resistance, oil resistance and solvent resistance, and is widely used in the decoration and protection of indoor and outdoor elastic floors with high decorative requirements in the industrial field. .

The two-component polyurethane varnish includes an isocyanate curing agent; the isocyanate group -N=C=O can undergo crosslinking reaction with OH at room temperature, and is a curing agent at room temperature. Regarding the curing reaction ratio, in the two-component polyurethane varnish of the present invention, the amount of the isocyanate curing agent is such that the molar ratio of hydroxyl groups to isocyanate groups (OH/NCO) is 1.05/1 to 1.3/1. In some embodiments of the present invention, the construction ratio is determined as the main agent: curing agent=4:1 (weight ratio). The two-component polyurethane varnish preferably further includes inorganic fillers, and the inorganic fillers can be selected from one or more of alumina and silica. In the formula design of the varnish layer of the present invention, the molar ratio of isocyanate group to hydroxyl group is appropriately increased, and inorganic fillers such as alumina and silica are added at the same time, so that it has excellent wear resistance and coordinated flexibility. It is a wear-resistant elastic polyurethane varnish that can reduce the damage of the coating caused by wear and tear.

The present invention has no special limitation on the production process of the varnish, and its production process flow can also be seen in FIG. 2 . The performance indicators of the polyurethane elastic floor varnish product obtained in the embodiment of the present invention are as follows: white milky liquid; outflow time≥20s, surface dry time≤4h, solid dry time≤24h; bending property of the obtained paint film≤2mm, cupping test result≥4mm , the cross-cut test result is less than or equal to grade 1, the impact resistance is greater than or equal to 50cm; the pot life is greater than or equal to 4h, and the mass ratio of the main agent and the curing agent can be 7/1.

In the present invention, the primer and varnish have self-leveling properties on various substrates, so that the paint film has excellent covering ability and elasticity. With the cooperation of the elastic polyurethane primer layer and the wear-resistant elastic polyurethane varnish layer, the aging resistance of the coating system can reach 3000h, far exceeding the 1000h of conventional coatings; it has good interlayer adhesion and can be maintained even if the coating is damaged. The whole system has strong cohesion to prevent the expansion of damage. The invention adopts an excellent curing system, the paint film is rapidly cross-linked and cured, and the cured paint film is non-toxic and free of irritating odor. In addition, the invention has short construction time and simple process requirements, is suitable for floor protection used in various environments, and has strong tolerance.

The invention provides a repairing method for rubber floor cloth, which comprises the following steps: coating and constructing the rubber floor cloth to be repaired with a single-component polyurethane primer, and drying; after the drying, using a two-component polyurethane varnish to The rubber floor cloth that has been constructed is painted again, dried, and the repaired rubber floor cloth is obtained;

The one-component polyurethane primer comprises: 20-40wt% of self-crosslinking polyurethane resin; 10-20wt% of hydroxyl acrylic resin; 10-20wt% of titanium dioxide; 5-10wt% of functional filler; 15wt% solvent; 0-15wt% auxiliary agent; and toning paste;

The two-component polyurethane varnish includes: elastic polyurethane resin, hydroxyacrylic acid dispersion and isocyanate curing agent.

In the present invention, an elastic coating system with excellent interlayer adhesion is formed by selecting an elastic coating with better flexibility. Expansion of the dismantling process of the maintenance vehicle caused by the replacement of the floor cloth, prolongation of the maintenance cycle, and waste caused by the replacement of the floor cloth. Through the application of this technology, it is possible to quickly and conveniently satisfy the repair of the rubber floor covering for the maintenance of official vehicles.

The contents of the primer and varnish of the present invention are as described above and will not be repeated here. The rubber floor cloth to be repaired is mainly changed in appearance and to be repaired, and may be a rubber floor cloth with appearances such as scratches, aging discoloration, loss of gloss, and even damage pits. In the embodiment of the present invention, the rubber floor cloth substrate to be repaired is first polished, cleaned, etc., so that the surface is clean, dry and free of moisture; the present invention can also perform conventional peripheral protection on the floor cloth.

Then, the embodiment of the present invention adopts the above-mentioned coating system for construction. The environmental conditions for the repairing construction in the embodiment of the present invention include: normal temperature, preferably 20-30° C.; 20%≤relative humidity≤60%. The coating construction methods can be spraying, brushing or roller coating, preferably roller coating. In the embodiment of the present invention, the dosage of the one-component polyurethane primer is generally 150-200 g/m ² ; the wet film thickness of the paint film is (80-100) μm, and the dry film thickness is (40-60) μm. The dosage of the two-component polyurethane varnish is generally 100-150 g/m ² ; the wet film thickness of the paint film is (80-100) μm, and the dry film thickness is (50-70) μm. The dry film thickness of each roll coating can be (30-40) μm; the total dry film thickness of the supporting system is ≥120 μm.

The drying time in some embodiments of the present invention is as follows: when the dry film thickness is 30-40 μm, no dust is sticky in 2 hours, and it dries hard in 24 hours; the product performance reaches the best after 7 days. In winter, the temperature is low, and the drying time will be slightly prolonged. Preferably, the one-component polyurethane primer and the two-component polyurethane varnish are independently dried in an environment of not lower than 15° C. for more than 9 hours. Some embodiments of the present invention are cured under natural conditions, and naturally dried in an environment of not lower than 15° C. for more than 16 hours. In other embodiments of the present invention, the temperature is lower or the drying time can be shortened, drying can be carried out in an environment heated to (40-60)° C. for (1-2) h, and then naturally dried for (8-10) h . In addition, the construction interval between the primer and the varnish in the examples of the present invention is ≥24 hours.

After the repair construction is completed, the performance of the repaired floor cloth is tested. The invention achieves the effect of apparent renovation by brushing the elastic coating on the basis of the original floor cloth; the construction process is simple, mature and feasible. The invention shortens the repair process, reduces the workload, and avoids the waste of floor cloth, and is a fast and convenient repair method.

In order to further understand the present application, the coating composition for repairing rubber floor cloth provided by the present application and its application will be specifically described below with reference to the examples.

Example

The composition of the one-component polyurethane primer used in this example is shown in Table 1:

The basic composition of primer in the embodiment of table 1

Each component of the present invention is a general-purpose product; wherein, the silicon-aluminum-based hollow microbeads are light-weight hollow microbeads formed by silicon and aluminum as the main component, which are formed by high temperature melting and strong airflow gasification and spraying under the protection of nitrogen. The interior is a tiny porous hollow structure, and the surface is made of a fibrous hollow network structure to form a hard shell. It is a standard physical spherical silica-alumina ceramic powder material with a particle size of 1 μm.

Mixed solvent: xylene: butyl acetate: propylene glycol methyl ether acetate = 3:2:2 (volume ratio). T-12 is a polyurethane coating drier, dibutyltin dilaurate C ₃₂ H ₆₄ O ₄ Sn.

The performance index of the polyurethane primer product is shown in Table 2:

The performance index of polyurethane primer product in the embodiment of table 2

The polyurethane floor varnish is made of hydroxy acrylic dispersion 1753 and elastic polyurethane 168SS-80, which are cold-blended according to the mass ratio of 1:2, and the flexible water-based isocyanate curing agent (Bayer Desmodur N 3390BA resin) is mixed in a certain proportion; among them, isocyanate The amount of curing agent is such that the molar ratio of hydroxyl groups to isocyanate groups (OH/NCO) is 1.1/1. The performance indicators of the varnish are shown in Table 3:

The performance index of polyurethane varnish product in the embodiment of table 3

The repair process in this embodiment is: grinding, cleaning, protection → floor drying → primer preparation → corner repair → primer construction → drying for 24 hours → sandpaper polishing → varnish preparation → edge repair → varnish construction → drying 24 hours → remove guard. The details are as follows:

Substrate treatment: Use a lint-free cloth to remove dust, oil and other pollutants on the floor, and then wipe it with thinner at least 1-2 times until the surface of the substrate is clean, dry and free of moisture before construction.

Peripheral protection: Confirm the parts to be constructed, and use adhesive strips to protect the legs of the dining table (see Figure 4); protect the junction between the car body and the floor cloth (see Figure 5).

Paint Preparation:

Preparation of components A and B before use: Open the lid of the polyurethane paint bucket of component A and stir evenly. The B-component curing agent (Bayer Desmodur N 3390BA resin) was shaken well. Special attention is that after taking the curing agent of component B, cover the cover of the curing agent immediately to prevent it from failing after being exposed to moisture in the air for too long. Mixing ratio: (1) The weight ratio of rose red polyurethane primer, main agent A: curing agent B=5:1; (2) The weight ratio of elastic polyurethane floor paint, main agent A: curing agent B=5:1. After the main agent and the curing agent are mixed in proportion, stir well to make them uniform, leave it to eliminate the bubbles generated during mixing, about 10 minutes, and then roll it. Wherein, use special diluent (mixed and prepared by xylene: butyl acetate: propylene glycol methyl ether acetate = 3:2:2 (volume ratio)) to dilute to a suitable viscosity. Applicable period: 3 hours in summer, 4 hours in winter.

The construction method is roller coating; tools include: lint-free cloth, sandpaper, electronic scale, wallpaper knife, coating 4# cup, agitator, high-quality oil brush, and high-quality roller brush. The dry film thickness of each roller coating is 30-40 μm; the total dry film thickness of the supporting system is ≥120 μm. The construction interval between rose red polyurethane base paint and elastic polyurethane floor paint is 24 hours; after the construction, the tools should be cleaned with special thinner immediately to avoid the waste of tools due to the curing of the paint.

The dosage of the polyurethane primer is 150-200 g/m ² , the wet film thickness of the paint film is (80-100) μm, and the dry film thickness is (40-60) μm. The dosage of polyurethane elastic floor varnish is 100-150 g/m ² , the wet film thickness of the paint film is (80-100) μm, and the dry film thickness is (50-70) μm. Cured under natural conditions and naturally dried at room temperature for 24 hours.

Precautions:

1 Before the coating film is dry, do not touch and step on it to avoid contamination or damage to the appearance of the paint film.

2. Use as much paint as you want, don't mix more, so as not to cause waste; paint A and B should be used up as soon as possible after mixing, and do not exceed the expiration date.

3. Construction workers should do personal protection required for spraying, use special work clothes, gloves, glasses, etc.; keep the environment ventilated.

4. The plastic film and tape for peripheral protection must be removed in time after the paint film is dry, so as to avoid damage to the paint film when removing the protective plastic film and tape after the paint film is completely dry.

The unpainted parts are well protected with no sanding damage or paint stains. After completing the repair construction, compare the performance test results before and after the floor cloth repair.

Among them, after the primer is dried, it is polished with a 240# abrasive sheet. The drying performance of the primer is good, and there is no sticking to the sandpaper. Sanded state after drying (right).

After the varnish is applied, the surface coating is uniform, the paint film is flat and smooth, and there is no accumulation, brush marks, missed coating, shrinkage holes, coarse particles, etc. . After the varnish was dried, the sample was inspected, and its drying performance was good; the sample was tested by folding, bending, etc., and the paint film had no defects such as cracking and falling off; Cracks; after the varnish is dried, the original floor cloth pattern appears, which is basically the same as the original floor cloth color. See Figure 8, Figure 9, and Figure 10 for the actual situation. In Figure 8, the upper part is the state after painting, the coating composition is base paint ① + varnish ②, and the lower part is the original state; after painting, the pattern appears and the color is darker. In Fig. 9, there is no abnormality in folding and bending; in Fig. 10, there is no abnormality in the coating after hammering.

After the rubber floor cloth is treated, the elastic coating on the surface of the floor cloth has no quality problems such as cracking, wrinkling and falling off, and meets the requirements of the beautiful and comfortable type of high-end passenger cars.

However, other existing polyurethane coatings or coatings other than the components and proportions of the present application cannot meet the elastic requirements of rubber floor coverings due to their different resin content and proportions. The movement of the rubber floor cloth and the change of the surface of the rubber floor cloth will cause problems such as cracking, brittleness, and edge skipping of the coating, which cannot meet the requirements.

As can be seen from the above content, the paint film of the present invention has good flexibility and elasticity, and utilizes the recoverable deformation of the system to buffer the deformation and stress of the rubber floor covering during use, so that it forms a whole with basically the same elastic modulus. The invention adopts an excellent curing system, the paint film is rapidly cross-linked and cured, the cured paint film is non-toxic and free of irritating odor, the construction time is short, and the process requirements are simple. The anti-aging performance of the coating system of the present invention can reach 3000h, far exceeding the 1000h of conventional coatings. The construction technology involved in the invention is simple, mature and feasible, and the effect of apparent renovation can be achieved by brushing the elastic coating on the basis of the original floor cloth. Moreover, the present invention has the advantages of shortening the repair process, reducing the workload, and avoiding the waste of floor coverings.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the technical principles of the present invention, various modifications to these embodiments can be realized, while These modifications should also be regarded as the scope of protection of the present invention.

Claims (9)

1. A coating composition for repairing rubber floor cloth comprises a single-component polyurethane base coat and a two-component polyurethane varnish;

the single-component polyurethane base coat comprises: 20-40 wt% of self-crosslinking polyurethane resin; 10-20 wt% of hydroxyl acrylic resin; 10-20 wt% of titanium dioxide; 5-10 wt% of a functional filler; 10-15 wt% of a solvent; 0-15 wt% of an auxiliary agent; and color mixing paste;

the two-component polyurethane varnish comprises: elastomeric polyurethane resin, hydroxyl acrylic dispersion and isocyanate curing agent: the hydroxyl acrylic acid dispersoid and the elastic polyurethane resin are cold spliced according to the mass ratio of 1: 2; in the two-component polyurethane varnish, the molar ratio of hydroxyl groups to isocyanate groups is 1.05/1-1.3/1 by using the amount of the isocyanate curing agent.

2. The coating composition of claim 1, wherein the functional filler has an average particle size of 0.01 to 1 μm.

3. The coating composition of claim 1, wherein the solvent is selected from one or more of aromatic hydrocarbon solvents, ketone solvents, and ester solvents.

4. The coating composition of claim 1, wherein the adjuvant is selected from one or more of a dispersant, a leveling agent, a defoamer, an anti-settling agent, an ultraviolet light absorber, a light stabilizer, an anti-blooming agent, and a sag preventive agent.

5. The coating composition of claim 1, wherein the adjuvant comprises: 0.6-1.2 wt% of a dispersant; 0.5 to 2 wt% of carbon black; 0.2-0.5 wt% of a leveling agent; 0.1-0.3 wt% of a defoaming agent; 0.3-0.5 wt% of an anti-settling agent; 0.5 to 1.5 wt% of an ultraviolet absorber; 0.5 to 1.5 wt% of a light stabilizer.

6. The coating composition of claim 1, wherein the two-component polyurethane varnish further comprises an inorganic filler selected from one or more of alumina and silica.

7. A method for repairing a rubber floor cloth, comprising the steps of:

coating and constructing the rubber floor cloth to be repaired by adopting the single-component polyurethane base color paint, and drying;

after drying, coating the constructed rubber floor cloth again by adopting two-component polyurethane varnish, and drying to obtain the repaired rubber floor cloth;

the single-component polyurethane base coat comprises: 20-40 wt% of self-crosslinking polyurethane resin; 10-20 wt% of hydroxyl acrylic resin; 10-20 wt% of titanium dioxide; 5-10 wt% of a functional filler; 10-15 wt% of a solvent; 0-15 wt% of an auxiliary agent; and color mixing paste;

the two-component polyurethane varnish comprises: an elastomeric polyurethane resin, a hydroxyacrylic acid dispersion and an isocyanate curing agent; the hydroxyl acrylic acid dispersoid and the elastic polyurethane resin are cold spliced according to the mass ratio of 1: 2; in the two-component polyurethane varnish, the molar ratio of hydroxyl groups to isocyanate groups is 1.05/1-1.3/1 by using the amount of the isocyanate curing agent.

8. The repairing method according to claim 7, wherein the amount of the one-component polyurethane base coat is 150-200 g/m²(ii) a The using amount of the two-component polyurethane varnish is 100-150 g/m²。

9. The repair method according to claim 7, wherein the one-component polyurethane base coat and the two-component polyurethane varnish are independently dried in an environment of not less than 15 ℃ for more than 9 hours.

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