PU (polyurethane) water-based refinishing paint and preparation method thereof
Technical Field
The invention relates to the technical field of paint coatings, in particular to a PU (polyurethane) water-based refinishing paint and a preparation method thereof.
Background
More and more interior furniture enterprises tend to use the water-based paint and the UV paint with low VOCs content, the water-based paint is widely applied to many hotels, high-grade suite furniture, children furniture and the like, a small amount of particles cannot be avoided on the surface of the furniture during production, collision cannot be avoided during transportation, small parts such as scratch, rub and collision are very easy to damage when a consumer uses the furniture, and the furniture needs to be repaired at the moment.
In chinese invention patent application publication No. CN110240835A, a transitional primer composition is disclosed, which comprises: the primer comprises a vinyl chloride-vinyl acetate copolymer and a solvent, wherein the vinyl chloride-vinyl acetate copolymer is 20-25 wt% of the total weight of the transition primer composition as 100%; wherein a paint film formed by the transitional primer composition is used as a transitional primer between the PVC substrate and the PU finishing paint. By taking 20-25 wt% of vinyl chloride-vinyl acetate copolymer as a main film forming substance, on one hand, the vinyl chloride-vinyl acetate copolymer has good adhesive force with a PVC (polyvinyl chloride) base material, and on the other hand, the vinyl chloride-vinyl acetate copolymer can be chemically crosslinked with PU (polyurethane) finish paint, so that a paint film formed by the transition primer and a PU coating form a whole to a certain extent, thereby playing a good bridging role between the PU finish paint and the PVC base material, and having moderate thickness of the paint film, thereby ensuring good adhesive force between the PU finish paint and the PVC base material.
However, when the transitional primer composition in the application document is used for repairing, a small amount of paint can be sprayed to non-polished places near furniture, and the places have no adhesive force and are easy to yellow and are not suitable for medium-high-grade furniture; in addition, the repair paint has a thin paint film, the water-based paint cannot form a film well during repair, the drying speed is slow, the adhesion is poor in a non-grinding place, and the overall adhesion is poor, so that a new scheme needs to be provided to solve the problems.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide the PU water-based refinishing paint to solve the technical problems, the PU water-based refinishing paint can be directly used without polishing when used for repairing small areas of scraped, wiped and damaged furniture, has good leveling property, and forms a paint film with excellent adhesive force.
In order to achieve the first purpose, the invention provides the following technical scheme:
a PU water-based refinishing paint comprises a component A and a component B which are stored independently and mixed according to the weight part ratio of (9-11) to 1 when in use, wherein the component A comprises the following raw materials in parts by weight:
10-30 parts of 20% vinyl chloride-vinyl acetate resin solution;
10-30 parts of 25% CAB liquid;
1-4 parts of fatty acid resin;
0.1-0.5 part of defoaming agent;
0.3-0.6 part of dispersant;
30-40 parts of butyl acetate;
3-7 parts of propylene glycol methyl ether acetate;
0.2-0.4 part of leveling agent;
6-10 parts of dimethylbenzene;
5-30 parts of ethyl acetate;
the component B comprises the following raw materials:
15-20 parts of HDI trimer;
30-40 parts of DS curing agent;
44-55 parts of butyl acetate;
0.3 to 0.5 portion of dehydrating agent.
By adopting the technical scheme, the 20% vinyl chloride-vinyl acetate resin solution has the characteristics of good drying property, quick hardness improvement, no grinding on a water-based surface, excellent adhesive force, self-drying and the like; the 25% CAB solution has good dryness and excellent leveling property on a water-based surface, can improve leveling degree on the water-based surface and quick drying of a paint film, and enables the paint film to be self-dried; meanwhile, the 20% vinyl chloride-vinyl acetate copolymer solution and the 25% CAB solution can play a good role in compounding and synergism, so that the PU water-based repair paint can be pressed dry in 1-2 minutes without leaving any trace when being sprayed and repaired, is not easy to fall dust, has good adhesive force in 8-10 minutes, can be packaged after 1-hour action, is more reworked than the conventional repair paint, greatly shortens the time, saves the cost, can better meet the production requirement, can be directly used without polishing when being used for repairing small areas of scraped, wiped and damaged furniture, and has good leveling property, and the formed paint film has excellent adhesive force.
The fatty acid resin has excellent fullness, toughness and high gloss, and can improve the fullness, toughness and gloss retention of a PU aqueous refinishing paint film. Butyl acetate, xylene, propylene glycol methyl ether acetate and ethyl acetate have strong dissolving power and inconsistent volatilization speed, play a role in diluting and providing reasonable volatilization gradient, are convenient for construction, and ensure that a paint film has no defects. The HDI tripolymer is not yellowed, has good flexibility, can perform chemical reaction with synthetic fatty acid in the formula, and improves the yellowing resistance and the toughness of a paint film. DS has quick drying and yellowing resistance, can react with synthetic fatty acid in a formula to improve the hardness and strength of a paint film, and butyl acetate plays a role in dilution. Meanwhile, the PU aqueous refinishing paint formed by mixing the component A and the component B not only greatly reduces the pollution to the environment and reduces the energy consumption, but also is a green, environment-friendly and sustainable coating scheme, improves the economic benefit, reduces the pollution to the environment and reduces the production cost.
More preferably, the ratio of the 20% of the vinyl chloride-vinyl acetate copolymer solution to the 25% of the CAB solution in the component A in parts by weight is preferably 1: 1.
by adopting the technical scheme, the 20% vinyl chloride-vinyl acetate resin solution can resist chemical corrosion in the coating, and the adhesive force of the PU water-based repair paint to the base material can be increased; the 25 percent CAB liquid can improve the leveling property of the PU aqueous refinishing paint, so that the PU aqueous refinishing paint can effectively inhibit sagging and shrinkage cavity when in use, thereby reducing surface defects; and when the weight part ratio of the 20% vinyl chloride-acetate copolymer solution to the 25% CAB solution is 1:1 when in use, the complex formulation effect of the components is optimal, and the capability of improving the adhesive force of the paint film is optimal.
Further preferably, the 20% of the vinyl chloride-vinyl acetate resin solution in the component A is xylene and cyclohexanone according to a weight part ratio of 1:1, matching with 20 percent of dissolved ternary vinyl chloride-vinyl acetate copolymer.
By adopting the technical scheme, the weight ratio of the selected materials is 1:1, dimethylbenzene and cyclohexanone are used as solvents, and then 20% of ternary vinyl chloride-vinyl acetate copolymer is dissolved to obtain 20% vinyl chloride-vinyl acetate copolymer liquid, which has the characteristics of good drying property, quick hardness improvement, no grinding on a water-based surface, excellent adhesive force, self-drying and the like, and can greatly improve the adhesive force of the PU water-based repair paint to a base material.
More preferably, the 25% CAB solution in the component A is 25% cellulose acetate CAB-551-0.2 solution dissolved by butyl acetate.
By adopting the technical scheme, the 25% CAB liquid obtained by the method has very good dryness and excellent key leveling property on the water-based surface, can improve the leveling degree on the water-based surface and the quick drying of a paint film, enables the paint film to dry by self, and enables the PU water-based repair paint to have good leveling property when scraped, wiped and damaged furniture is not polished, thereby further playing a good repairing effect.
More preferably, the defoamer in the component A is a Defom5300F defoamer.
By adopting the technical scheme, air can easily enter the PU water-based repair paint to form micro bubbles due to stirring, when the PU water-based repair paint is cured, the micro bubbles in the PU water-based repair paint are easy to migrate and are polymerized together to form larger bubbles, and the Defom5300F defoaming agent can play a good defoaming and defoaming role, has very good compatibility, and has the functions of improving the workability and improving the appearance of a paint film.
More preferably, the dispersant in the component A is EFKA-4010 dispersant.
By adopting the technical scheme, the EFKA-4010 dispersing agent can reduce the surface tension, prevent the sedimentation and the coagulation of solid particles, improve the compatibility among raw materials of all components, increase the wettability to a substrate and improve the leveling degree of a paint film.
1045 the weight portion ratio of the leveling agent is (1-2) to 1. ADD1045, BYK-310 and HANSA ADD, wherein BYK-310 and HANSA are selected as leveling agents in the component A
1045 the use of the leveling agent, the surface tension of the PU aqueous refinishing paint can be reduced, and the rapid leveling of the paint film can be promoted, so that the PU aqueous refinishing paint forms a flat, smooth and uniform coating film in the process of drying and film forming, and the PU aqueous refinishing paint can keep good and stable repairing effect. The ADD adopts the technical proposal that BYK-310 flatting agent and HANSA are adopted
More preferably, the dehydrating agent in the component A is FL-180 dehydrating agent.
By adopting the technical scheme, the FL-180 dehydrating agent has good compatibility with water, and can separate moisture from solvents such as butyl acetate and the like, so that the moisture in the component B storage tank can be absorbed by the solvent, and the storage and the use of the component B are ensured.
The invention also aims to provide a preparation method of the PU aqueous refinishing paint, when the PU aqueous refinishing paint prepared by the method is used for repairing small areas of scraped, rubbed and damaged furniture, the repair paint can be directly used without polishing, and has good leveling property, and a formed paint film has excellent adhesive force.
In order to achieve the second purpose, the invention provides the following technical scheme, which comprises the following steps:
step one, premixing raw materials, namely adding 20% of vinyl chloride-vinyl acetate copolymer solution, 25% of CAB solution, fatty acid resin, a defoaming agent, a dispersing agent, butyl acetate and propylene glycol monomethyl ether acetate into a dispersion cylinder in corresponding parts by weight, starting a dispersion machine, and stirring for 5-10 minutes at the speed of 500 plus materials/min to obtain a premix;
step two, preparing slurry, sequentially adding the corresponding parts by weight of flatting agent, xylene and ethyl acetate into the premix, stirring and dispersing for 10-12min at the speed of 500-;
and step three, preparing and curing, namely filling nitrogen into a stirring kettle, evacuating, then pumping the HDI tripolymer, the OK.DS curing agent, the butyl acetate and the dehydrating agent in corresponding parts by weight into the stirring kettle in vacuum, stirring and dispersing for 15-20min at the speed of 700 plus materials at 900r/min to obtain a component B, filling in the nitrogen in vacuum, and storing for later use.
By adopting the technical scheme, the process can fully mix the raw materials of the components, the obtained component A and the component B have good and stable storage performance, and a good compounding and synergism effect can be achieved between 20% of vinyl chloride-vinyl acetate copolymer (vinyl chloride-vinyl acetate copolymer) solution and 25% of CAB solution, so that the PU water-based repair paint can be directly repaired without polishing on a water-based surface when being simply mixed and applied, the problems of poor adhesion and poor leveling can be avoided, the same gloss can be adjusted according to the gloss of the existing finish paint, and no trace is left after the repair. Meanwhile, the production process is simple and convenient to operate and is not easy to produce large pollution.
In summary, compared with the prior art, the invention has the following beneficial effects:
(1) the 20% vinyl chloride-vinyl acetate copolymer solution and the 25% CAB solution can play a good role in compounding and synergism, so that the PU water-based repair paint can be directly used without polishing when being sprayed and repaired, and has good leveling property when being used for repairing small areas of scraped, scraped and damaged furniture, and the formed paint film has excellent adhesive force;
(2) the 20% vinyl chloride-vinyl acetate resin solution is prepared from dimethylbenzene and cyclohexanone according to the weight ratio of 1:1, matching with 20 percent of dissolved ternary vinyl chloride-vinyl acetate copolymer; the 25% CAB solution is 25% cellulose acetate CAB-551-0.2 solution dissolved by butyl acetate; when the PU water-based repair paint is simply mixed and applied, the PU water-based repair paint can be directly repaired without polishing on a water-based surface, the problems of poor adhesion and poor leveling can be avoided, the same gloss can be adjusted according to the gloss of the existing finish paint, and no trace is left after the repair.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
The invention is described in detail below with reference to the figures and examples.
Example 1: a PU water-based refinishing paint comprises a component A and a component B which are stored independently and mixed according to the weight part ratio of 10:1 when in use, wherein each component and the corresponding weight part are shown in Table 1, and the PU water-based refinishing paint is prepared by the following steps:
firstly, premixing raw materials, namely adding 20% vinyl chloride-vinyl acetate resin solution, 25% CAB solution, fatty acid resin, a Defom5300F antifoaming agent, an EFKA-4010 dispersing agent, butyl acetate and propylene glycol monomethyl ether acetate in corresponding parts by weight into a dispersion cylinder, starting a dispersion machine, and stirring for 7.5 minutes at 600r/min to obtain a premix;
1045 stirring and dispersing the flatting agent, xylene and ethyl acetate at 600r/min for 11min to obtain component A, filling nitrogen gas in vacuum, and storing for later use; adding ADD step two, preparing slurry, and adding BYK-310 flatting agent and HANSA in corresponding weight parts in turn into the premix
And step three, preparing and curing, namely filling nitrogen into a stirring kettle, evacuating, then pumping the HDI tripolymer, the OK.DS curing agent, the butyl acetate and the FL-180 dehydrating agent in corresponding parts by weight into the stirring kettle in vacuum, stirring and dispersing for 17.5min at the speed of 800r/min to obtain a component B, filling in the nitrogen in vacuum, and storing for later use.
Note: in the above step, the 20% vinyl chloride-vinyl acetate resin solution is xylene and cyclohexanone in a weight ratio of 1:1, matching with 20 percent of dissolved ternary vinyl chloride-vinyl acetate copolymer; the 25% CAB solution was 25% cellulose acetate CAB-551-0.2 solution dissolved in butyl acetate.
Examples 2 to 9: a PU aqueous refinishing paint, different from example 1 in that the components and their respective parts by weight are as shown in table 1.
TABLE 1 Components and parts by weight of examples 1-9
Example 10: a PU water-based refinishing paint comprises a component A and a component B which are stored separately and are mixed according to the weight part ratio of 9:1 when in use, and is different from the PU water-based refinishing paint in the embodiment 1 in that the refinishing paint is prepared by the following steps:
firstly, premixing raw materials, namely adding 20% vinyl chloride-vinyl acetate resin solution, 25% CAB solution, fatty acid resin, a Defom5300F antifoaming agent, an EFKA-4010 dispersing agent, butyl acetate and propylene glycol monomethyl ether acetate in corresponding parts by weight into a dispersion cylinder, starting a dispersion machine, and stirring for 5 minutes at 700r/min to obtain a premix;
1045 stirring and dispersing the flatting agent, xylene and ethyl acetate at 700r/min for 10min to obtain component A, filling nitrogen in vacuum, and storing for later use; adding ADD step two, preparing slurry, and adding BYK-310 flatting agent and HANSA in corresponding weight parts in turn into the premix
And step three, preparing and curing, namely filling nitrogen into a stirring kettle, evacuating, then pumping the HDI tripolymer, the OK.DS curing agent, the butyl acetate and the FL-180 dehydrating agent in corresponding parts by weight into the stirring kettle in vacuum, stirring and dispersing for 15min at 900r/min to obtain a component B, filling the component B in vacuum by filling nitrogen, and storing for later use.
Example 11: a PU water-based refinishing paint comprises a component A and a component B which are stored separately and are mixed according to the weight part ratio of 11:1 when in use, and is different from the PU water-based refinishing paint in the embodiment 1 in that the refinishing paint is prepared by the following steps:
firstly, premixing raw materials, namely adding 20% vinyl chloride-vinyl acetate resin solution, 25% CAB solution, fatty acid resin, a Defom5300F antifoaming agent, an EFKA-4010 dispersing agent, butyl acetate and propylene glycol monomethyl ether acetate in corresponding parts by weight into a dispersion cylinder, starting a dispersion machine, and stirring for 10 minutes at 500r/min to obtain a premix;
1045 stirring and dispersing the flatting agent, xylene and ethyl acetate at 500r/min for 12min to obtain component A, filling nitrogen in vacuum, and storing for later use; adding ADD step two, preparing slurry, and adding BYK-310 flatting agent and HANSA in corresponding weight parts in turn into the premix
And step three, preparing and curing, namely filling nitrogen into a stirring kettle, evacuating, then pumping the HDI tripolymer, the OK.DS curing agent, the butyl acetate and the FL-180 dehydrating agent in corresponding parts by weight into the stirring kettle in vacuum, stirring and dispersing for 20min at 700r/min to obtain a component B, filling the component B in vacuum by filling nitrogen, and storing for later use.
Comparative example 1: the PU water-based refinishing paint is different from the PU water-based refinishing paint in the embodiment 1, and the step one is specifically set as the steps of premixing raw materials, adding 20% vinyl chloride-vinyl acetate solution, fatty acid resin, Defom5300F antifoaming agent, EFKA-4010 dispersing agent, butyl acetate and propylene glycol monomethyl ether acetate in corresponding parts by weight into a dispersion cylinder, starting a dispersion machine, and stirring for 7.5 minutes at 600r/min to obtain the premix.
Comparative example 2: the PU water-based refinishing paint is different from the PU water-based refinishing paint in example 1 in that the first step is specifically set as that raw materials are premixed, 25% CAB liquid, fatty acid resin, Defom5300F defoamer, EFKA-4010 dispersant, butyl acetate and propylene glycol methyl ether acetate in corresponding parts by weight are added into a dispersion cylinder, a dispersion machine is started, and the mixture is stirred for 7.5 minutes at 600r/min to obtain the premix.
Comparative example 3: the PU waterborne refinishing paint is different from the PU waterborne refinishing paint in the embodiment 1 in that the first step is specifically set as the steps of premixing raw materials, adding fatty acid resin, a Defom5300F antifoaming agent, an EFKA-4010 dispersing agent, butyl acetate and propylene glycol monomethyl ether acetate in corresponding parts by weight into a dispersion cylinder, starting a dispersion machine, and stirring for 7.5 minutes at 600r/min to obtain the premix.
Comparative example 4: a PU water-based refinishing paint is different from the example 1 in that the weight part ratio of 20 percent of vinyl chloride-vinyl acetate copolymer solution to 25 percent of CAB solution in the component A is preferably 1: 1.5, wherein the weight part of the 20% vinyl chloride-vinyl acetate copolymer solution is 10, and the weight part of the 25% CAB solution is 15.
Comparative example 5: a PU water-based refinishing paint is different from the example 1 in that the weight part ratio of 20 percent of vinyl chloride-vinyl acetate copolymer solution to 25 percent of CAB solution in the component A is preferably 1.5: 1, wherein the 20% vinyl chloride-vinyl acetate copolymer solution is 15 parts by weight, and the 25% CAB solution is 10 parts by weight.
Comparative example 6: a PU water-based refinishing paint is different from the example 1 in that the weight part ratio of 20 percent of vinyl chloride-vinyl acetate copolymer solution to 25 percent of CAB solution in the component A is preferably 1:1, wherein the 20% vinyl chloride-vinyl acetate copolymer solution is 9 parts by weight, and the 25% CAB solution is 9 parts by weight.
Comparative example 7: a PU water-based refinishing paint is different from the example 1 in that the weight part ratio of 20 percent of vinyl chloride-vinyl acetate copolymer solution to 25 percent of CAB solution in the component A is preferably 1:1, wherein the 20% vinyl chloride-vinyl acetate copolymer solution is 31 parts by weight, and the 25% CAB solution is 31 parts by weight.
Performance testing
Test samples: the PU aqueous refinish paints obtained in examples 1 to 11 were used as test samples 1 to 11, and the PU aqueous refinish paints obtained in comparative examples 1 to 7 were used as control samples 1 to 7.
The test method comprises the following steps: the PU aqueous refinish paints in test samples 1-11 and control samples 1-7 were tested according to current national standards for gloss/° initial viscosity/T4 cup, surface drying, press drying, nail scratch adhesion after 10min, 2h louvre adhesion, odor, leveling, yellowing resistance (Δ Ε ≦ 3), storage and 2h anti-tack properties and recorded in tables 2 and 3, respectively.
And (3) test results: the test results of examples 1 to 11 are shown in Table 2, and the test results of comparative examples 1 to 7 are shown in Table 3. As can be seen from tables 2 and 3, by comparing the test results of example 1 and examples 2 to 11, the ranges of the components disclosed in the present invention are all used for the preparation of the aqueous PU repair paint, and the obtained aqueous PU repair paint has good and stable effects. Compared with the test results of the embodiment 1 and the comparative examples 1 to 3, the 20 percent of the vinyl chloride-vinyl acetate copolymer solution and the 25 percent of the CAB solution have good compounding and synergism, and the adhesive force and the leveling property of the PU water-based repair paint can be greatly improved. From the comparison of the test results of example 1 and comparative examples 4 to 7, when the ratio of the 20% vinyl chloride-vinyl acetate resin solution to the 25% CAB solution in parts by weight is 1:1 when in use, the complex formulation effect is optimal, and the improvement capability on the adhesive force and the leveling property of the paint film is optimal.
TABLE 2 test results for examples 1-11
TABLE 3 test results for comparative examples 1-7
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.