Preparation method of water-based environment-friendly paint based on biopolymer

Abstract

The invention relates to the field of production and preparation of chemical paint, in particular to a preparation method of water-based environment-friendly paint based on biopolymer, which comprises the following steps: S1, raw material pretreatment; s2, emulsion polymerization; s3, synthesizing bio-based resin; s4, dispersing the slurry; s5, blending a functional auxiliary agent; s6, filtering and packaging; the technical problem that in the production and preparation process of existing water-based environment-friendly paint, especially when slurry is stirred and dispersed, the efficiency is low, and consequently the working procedure duration needs to be prolonged is solved.

Description

Technical Field

[0001] The present invention relates to the field of chemical paint production and preparation, and particularly to a preparation method of a water-based environmentally friendly paint based on biopolymers. Background Art

[0002] The water-based environmentally friendly paint based on biopolymers replaces traditional petroleum-based materials with renewable biomass raw materials (such as vegetable oils and plant fibers), and combines water-based solvent technology to form a green coating solution with low pollution and high performance.

[0003] Compared with traditional coatings, its raw materials can use renewable raw materials such as vegetable oils like soybean oil, and plant fibers like wheat straw and corn stalks; and compared with traditional coatings, it uses water as the dispersion medium, the TVOC release amount can be as low as 254 μg / m³ (only 50% of the standard limit), and the formaldehyde content approaches zero; at the same time, the waste film of traditional coatings is difficult to degrade, polluting the soil and water sources, while the waste film of bio-based water-based paint can be naturally degraded into harmless substances, and it is environmentally friendly throughout the life cycle.

[0004] In terms of production and preparation, the bio-based water-based environmentally friendly paint is different from traditional coatings. It does not require explosion-proof equipment and forced drying equipment, and only needs to transform conventional water-based equipment. The preparation process achieves lower energy consumption and higher environmental friendliness. The main transformation points for transforming conventional water-based equipment are the stirring and dispersion of the slurry and the final filtration and packaging, so as to improve the quality of the finished product. The invention patent with the Chinese patent application number 202411896369.5 discloses a preparation method of an environmentally friendly water-based metallic paint, which relates to the technical field of the preparation of environmentally friendly water-based metallic paint. The method includes the following steps: 35-55 parts of polyacrylate emulsion, 7-15 parts of antifreeze thickening liquid intermediate, 15-25 parts of deionized water, 5-10 parts of environmentally friendly pigment, 2-7 parts of sodium polycarboxylate, 2-4 parts of polyether-modified silicone, 1-3 parts of fluorocarbon compound, 5-10 parts of water-based aluminum silver paste, 2-6 parts of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 1-3 parts of sodium benzoate, 0.5-1.5 parts of pH regulator. The invention prepares an environmentally friendly water-based metallic paint by adding an antifreeze thickening liquid intermediate, which can effectively lower the freezing point of the paint, ensure that the paint will not freeze in a low-temperature environment, thereby maintaining its good fluidity and construction performance, and increasing the viscosity and consistency of the paint, preventing the paint from sagging, flowing or splashing during construction, improving the smoothness and covering power of the coating, and reducing the paint layering situation after the metallic paint is shaken. The technical solution proposed by the above invention has no improvement and innovation in the stirring and dispersion process during the preparation process of the water-based environmentally friendly paint. It directly adopts the traditional stirring process, so it is difficult to improve the efficiency of slurry dispersion and because it is necessary to achieve complete uniform dispersion of the slurry, the stirring time needs to be extended. Summary of the Invention

[0005] Therefore, in view of the above problems, the present invention provides a preparation method of a water-based environmentally friendly paint based on biopolymers, which solves the technical problem that the existing water-based environmentally friendly paint has low efficiency during the production and preparation process, especially during the stirring and dispersion of the slurry, resulting in an extended duration of this process.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A preparation method of a water-based environmentally friendly paint based on biopolymers, comprising the following steps: S1. Raw material pretreatment; soybean oil modification and cellulose hydroxyalkylation, modified into a bio-based polymer through transesterification and hydrolysis processes, to obtain 100 - 120 parts of bio-based polymer raw materials; S2. Emulsion polymerization; add 3 - 5 parts of 10 - 18% methyl methacrylate and 3 - 5 parts of 10 - 20% n-butyl acrylate monomers to the bio-based polymer raw materials prepared in step S1, and carry out emulsion polymerization under the action of 2 - 4 parts of 0.1 - 0.3% initiator to generate an acrylic resin emulsion, and then add 5 - 8 parts of 0.1 - 0.8% triisopropanolamine to adjust the pH value of the mixed raw materials to 7 - 8; S3. Bio-based resin synthesis; the first step is to use 100 - 120 parts of rosin acid as raw material, generate rosin-based polyol and rosin epoxy resin through esterification and epoxidation reactions, and then carry out polycondensation with 10 - 12 parts of polyester prepolymer to form a water-based epoxy ester dispersion, and then add 10 - 12 parts of cellulose nanocrystals to make it composite with the water-based epoxy ester; the second step is to compound 5 - 8 parts of 70 - 80% bio-based polyurethane dispersion liquid with 5 - 8 parts of 40 - 60% polysiloxane dispersion liquid; then mix and stir the mixture prepared in the first step with the mixture prepared in the second step; S4. Slurry dispersion; add 100 - 120 parts of water, 5 - 8 parts of 0.1 - 0.6% dispersant, and 5 - 8 parts of 0.3 - 0.6% silica modified type to the dispersion tank, and sequentially add 10 - 12 parts of 14 - 25% heavy calcium and 10 - 12 parts of 14 - 20% titanium dioxide extender pigment, and stir at high speed for 20 - 40 minutes until evenly dispersed. During the stirring process, add the mixture in step S2 and the mixture in step S3; S5. Functional additive formulation; add 5 - 8 parts of 0.5 - 1.5% film-forming aid during the stirring process of the slurry dispersion in step S4 to reduce the minimum film-forming temperature, and add 5 - 8 parts of 0.5 - 5% propylene glycol to improve the low-temperature stability; S6. Filtration and packaging; filter with a sieve of more than 200 meshes to remove undispersed particles and impurities in the final mixture after stirring and dispersion in step S5.

[0007] Further, the slurry dispersion process in step S4 includes the following sub-processes: S4.1. Initial dispersion and stirring: 5-10 minutes before the stirring process, the dispersion tank is kept stationary and the stirring roller in the dispersion tank is only used for stirring in the horizontal direction; S4.2, secondary dispersion stirring: The secondary dispersion stirring begins after the 10th minute of the stirring process. The stirring tank body in the dispersion tank is turned over with the horizontal plane as the reference plane. The turning frequency is 10-15 seconds to complete a complete turning. The stirring rollers in the stirring tank body are stirred in the horizontal and vertical directions simultaneously. The secondary dispersion stirring continues until the end of the stirring process.

[0008] Furthermore, the dispersion tank includes a supporting base, a tumbling device arranged on the supporting base, and a stirring tank body movably arranged on the tumbling device. The tumbling device includes two oppositely arranged supporting stands and a rotating support beam arranged between the two supporting stands. The rotating support beam is driven to rotate by a rotating motor. The stirring tank body is arranged on the rotating support beam and rolls up and down following the rotation of the rotating support beam.

[0009] Furthermore, a buffer rubber layer is provided on the lower bottom surface of the support base, the thickness of the buffer rubber layer is 1-3 cm, and the buffer rubber layer is hard rubber.

[0010] Furthermore, the vertical cross-section of the rotating support beam is a structure with a central rectangle and semicircular ends, the mixing tank body is provided with a connecting hole that passes through the mixing tank body, the mixing tank body is inserted into the rotating support beam through the connecting hole, the hole diameter length of the connecting hole is greater than the rod diameter length of the rotating support beam, and the first pushing portion and the second pushing portion are respectively provided near the two end positions in the connecting hole, the first pushing portion and the second pushing portion have the same structure, the first pushing portion includes a first pushing rod and a second pushing rod that are relatively arranged, and the second pushing portion includes a third pushing rod and a fourth pushing rod that are relatively arranged, the rotating support beam is provided with a pushing hole that cooperates with the first pushing rod, the second pushing rod, the third pushing rod and the fourth pushing rod, the first pushing rod and the fourth pushing rod move in conjunction with each other, the second pushing rod and the third pushing rod move in conjunction with each other, and during the rotation of the rotating support beam, the first pushing portion and the second pushing portion always abut against the rotating support beam.

[0011] Furthermore, the free ends of the first push rod, the second push rod, the third push rod and the fourth push rod are all provided with sliding balls, and the first push rod, the second push rod, the third push rod and the fourth push rod can all be lifted up and down along their own axial directions.

[0012] Further, a feed inlet and a discharge outlet are provided on the stirring tank body. A central rotating shaft is provided inside the stirring tank body. A first stirring roller group and a second stirring roller group are provided on the central rotating shaft. A drainage guide plate group is provided on the inner side surface of the stirring tank body, and the drainage guide plate group is provided at the central position of the stirring tank body.

[0013] Further, the drainage guide plate group includes a first annular drainage guide plate, a second annular drainage guide plate, and a third annular drainage guide plate. The number of the first annular drainage guide plates is one, and the number of the second annular drainage guide plates and the third annular drainage guide plates is two each. The setting method is that with the first annular drainage guide plate as the symmetry center, the second annular drainage guide plate and the third annular drainage guide plate are symmetrically arranged on both sides of the first annular drainage guide plate. The surface areas of the first annular drainage guide plate, the second annular drainage guide plate, and the third annular drainage guide plate decrease in sequence, and all three generate metallic elastic deformation under the action of an external force.

[0014] Further, the first stirring roller group includes a first stirring main roller and a first stirring auxiliary roller that are parallel to each other. The second stirring roller group includes a second stirring main roller and a second stirring auxiliary roller. The first stirring main roller and the second stirring main roller have the same structure. The first stirring auxiliary roller and the second stirring auxiliary roller have the same structure and are parallel to each other. A first screen is provided on the first stirring main roller, and a second screen is provided on the second stirring main roller. Both the first screen and the second screen are perpendicular to the horizontal plane.

[0015] Further, both the first stirring auxiliary roller and the second stirring auxiliary roller extend outward to overlap with the first annular drainage guide plate in the horizontal plane projection. The first stirring auxiliary roller and the second stirring auxiliary roller are respectively located on the upper and lower sides of the first annular drainage guide plate. First annular convex portions and second annular convex portions are respectively provided around the upper and lower side surfaces of the first annular drainage guide plate. The first annular convex portion cooperates with the first stirring auxiliary roller, and the second annular convex portion cooperates with the second stirring auxiliary roller.

[0016] By adopting the foregoing technical solutions, the beneficial effects of the present invention are: 1. This invention application is different from traditional coatings, and the preparation process it adopts is also different from that of traditional coatings. Compared with traditional coatings, the advantages of the water-based environmentally friendly paint based on biopolymers produced by the preparation process proposed in this invention application lie in its safety in use, without pungent odor during the use process, and since environmentally friendly materials are used as raw materials, the formaldehyde content can approach zero. At the same time, it can combine the weather resistance and abrasion resistance of traditional coatings; by using renewable raw materials such as vegetable oils and plant fibers, fossil energy consumption can be reduced; at the same time, the waste film of the bio-based water-based paint can be naturally degraded into harmless substances, and it is environmentally friendly throughout the life cycle; compared with traditional paint materials, the water-based paint penetrates the substrate fibers through nano-scale resin, and the adhesion reaches level 1-2, and the sealing property is better, while traditional coatings can only reach level 2-3; traditional coatings rely on solvents to form films, with high initial hardness but easy to embrittle; the two-component hardness of the bio-based water-based paint can reach 1-2H (equivalent to PU paint), and the flexibility is better; the bio-based coating does not contain easily yellowing substances such as TDI and nitrocellulose, and has better color stability during long-term use.

[0017] 2. In the synthesis of the bio-based resin in step S3 of this invention application, cellulose nanocrystals are added. Cellulose nanocrystals themselves have high mechanical strength, with a Young's modulus of 150 GPa, which can significantly improve the hardness and abrasion resistance of the coating. At the same time, it is biodegradable and there is no risk of microplastic pollution during the production process. When applied in water-based paint, after being compounded with water-based polyurethane, the tensile strength is increased by 85%, from 28.2 MPa to 52.3 MPa, and its nano-scale structure can effectively block water vapor and oxygen, extending the anti-corrosion life of the substrate. At the same time, it improves the leveling property of the paint through hydrogen bond interaction, reducing the brushing marks; by adding rosin derivatives, it can greatly enhance the chemical properties of the water-based environmentally friendly paint, providing functions of flame retardancy, dynamic cross-linking and biodegradation, making the flame retardancy grade reach UL94 V-0, and the elastic modulus is increased by 40%; the synergistic application of the two in water-based paint realizes a double breakthrough in high performance and sustainable development.

[0018] 3. The dispersion tank used in the preparation method of the present invention is also different from existing equipment. It is mainly used to complete the slurry dispersion process in step S4. Step S4 includes primary dispersion stirring and secondary dispersion stirring to improve the stirring efficiency per unit time. In particular, the secondary dispersion stirring can make the slurry in the tank body turn upside down by completely turning the stirring tank body, thereby achieving more uniform dispersion stirring. The dispersion tank includes a support base, a rolling device, and a stirring tank body. The support base is used to provide stability for the whole device. The bottom surface thereof, which is the surface in contact with the ground, is provided with a buffer rubber layer, which can provide buffering for the device during operation to avoid the shaking generated during the operation of the device being transmitted to the ground to generate noise. In the rolling device of the present invention, rotation is mainly achieved by rotating the support cross beam. The rotating support cross beam is arranged in the stirring tank body, and the rotation of the stirring tank body is driven by the rotation of the rotating support cross beam. Through the ingenious design that the aperture length of the connection hole on the stirring tank body is greater than the rod diameter length of the rotating support cross beam, it is ensured that the rotation of the stirring tank body can not only be turned upside down but also deflect on the horizontal plane. The principle is the first pushing part and the second pushing part in the connection hole, specifically the mutual cooperation of the first push rod, the second push rod, the third push rod, and the fourth push rod. When the first push rod and the fourth push rod push outwards, the second push rod and the third push rod retract correspondingly, and the stirring tank body tilts along one side, thereby driving the paint in the tank body to tilt. Correspondingly, when the second push rod and the third push rod push outwards, the first push rod and the fourth push rod retract correspondingly, and the stirring tank body tilts along the other side. The four push rods are independently driven by motors to push outwards or retract inwards. Such reciprocating motion makes the stirring tank body deflect horizontally during the up-and-down rolling process, making the paint inside it more uniformly mixed, dispersed, and stirred.

[0019] 4. Another innovation point of the present invention lies in the structural design inside the stirring tank body. It improves and innovates the conventional stirring structure. The stirring device mainly includes a stirring roller group and a drainage guide plate group, and there is an interlocking relationship between them in the design. The stirring roller group includes a first stirring roller group and a second stirring roller group. The first main stirring roller and the second main stirring roller play a major and large-scale stirring role, and by respectively setting a first screen and a second screen, on the one hand, the contact area of stirring is increased, and on the other hand, when the paint passes through the screen, there will be a process of being refined and dispersed. The first auxiliary stirring roller and the second auxiliary stirring roller are used to play an auxiliary stirring role and generate an interlock with the drainage guide plate group.

[0020] 5. The drainage guide plate group includes a first annular drainage guide plate, a second annular drainage guide plate, and a third annular drainage guide plate. Through the structural design in which the surface areas of the first annular drainage guide plate, the second annular drainage guide plate, and the third annular drainage guide plate decrease in sequence, a conical structure stacked up and down is formed in the stirring tank body. Along with the tumbling of the stirring tank body, the internal coating continuously performs a falling and stirring operation from top to bottom. When it contacts the annular drainage guide plate, the annular drainage guide plate will deflect due to its own gravity. At this time, the first annular convex part and the second annular convex part on the deflected first annular drainage guide plate respectively contact the first stirring sub-roller and the second stirring sub-roller. Along with the rotation of the first stirring sub-roller and the second stirring sub-roller, the first annular convex part and the second annular convex part are continuously knocked, and the first annular drainage guide plate will generate vibration, and the generated vibration is further transmitted to the water-based paint to assist the dispersion and stirring process to be more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 It is a flow chart of the preparation method of the present invention; Figure 2 It is a schematic structural diagram of the dispersion tank of the present invention; Figure 3 It is a schematic side structure diagram of the stirring tank body of the present invention; Figure 4 is Figure 3 the enlarged view at A in Figure 5 It is a schematic diagram of the principle of the horizontal plane inclination of the stirring tank body of the present invention; Figure 6 It is a schematic internal structure diagram of the stirring tank body of the present invention; Figure 7 It is a schematic cross-sectional side structure diagram of the first annular drainage guide plate of the present invention; Figure 8 It is a schematic top view structure diagram of the first annular drainage guide plate of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the technical means, creative features, achieved purposes, and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0023] Please refer to Figures 1-8 , the present invention provides a preparation method of a water-based environmentally friendly paint based on a biopolymer, including the following steps: S1, raw material pretreatment; soybean oil modification and cellulose hydroxyalkylation, modified into bio-based polymers through ester exchange and hydrolysis processes, and prepared 100 parts of bio-based polymer raw materials; wherein soybean oil modification adopts epoxidation modification, and double bond epoxidation is catalyzed by formic acid and hydrogen peroxide system to make the epoxide value reach 4.78; cellulose hydroxyalkylation adopts etherification reaction to introduce hydroxyethyl and hydroxypropyl into cellulose molecular chain to improve reaction activity; ester exchange and hydrolysis process modification is to react hydroxyalkylated cellulose with acetic anhydride to generate cellulose acetate with stronger hydrophobicity, and the formation of ester bond can adjust the hydrophilic and hydrophobic balance of the material; S2, emulsion polymerization: adding 3 parts of 10% methyl methacrylate and 3 parts of 10% n-butyl acrylate monomers to the bio-based polymer raw material prepared in step S1, and performing emulsion polymerization under the action of 2 parts of 0.1% initiator to generate an acrylic resin emulsion, and then adding 5 parts of 0.1% triisopropanolamine to adjust the pH value of the mixed raw material to 7-8; the initiator in this step is dibenzoyl peroxide; S3, synthesis of bio-based resin; the first step is to use 100 parts of rosin acid as raw materials, generate rosin-based polyol and rosin epoxy resin through esterification and epoxidation reaction, and then condense with 10 parts of polyester prepolymer to form water-based epoxy ester dispersion, and then add 10 parts of cellulose nanocrystals to make it composite with the water-based epoxy ester; the second step is to compound 5 parts of 70% bio-based polyurethane dispersion with 5 parts of 40% polysiloxane dispersion; then mix and stir the mixture obtained in the first step with the mixture obtained in the second step; S4, slurry dispersion: add 100 parts of water, 5 parts of 0.1% dispersant, and 5 parts of 0.3% modified silica to a dispersion tank, add 10 parts of 14% heavy calcium and 10 parts of 14% titanium dioxide extender pigment in sequence, stir at high speed for 40 minutes until uniformly dispersed, and add the mixture in step S2 and the mixture in step S3 during stirring; S5, functional additive preparation: in the process of stirring the slurry dispersion in step S4, 8 parts of 1.5% film-forming additive are added to lower the minimum film-forming temperature, and 8 parts of 3.5% propylene glycol are added to improve low temperature stability; S6, filtering and packaging; using a 350-mesh screen to filter and remove undispersed particles and impurities in the final mixture after stirring and dispersing in step S5.

[0024] The slurry dispersion process in step S4 includes the following subdivision processes: S4.1. Initial dispersion and stirring: Initial dispersion and stirring is performed 10 minutes before the stirring process. The dispersion tank remains stationary and the stirring roller in the dispersion tank performs stirring operations in the horizontal direction only. S4.2, secondary dispersion stirring: The secondary dispersion stirring is started after the 10th minute of the stirring process. The stirring tank body in the dispersion tank is turned over with the horizontal plane as the reference plane. The turning frequency is 10 seconds to complete a complete turning. The stirring rollers in the stirring tank body are stirred in the horizontal and vertical directions simultaneously. The secondary dispersion stirring continues until the end of the stirring process.

[0025] The dispersion tank used in the preparation method includes a support base 1, a tumbling device arranged on the support base 1, and a stirring tank body 3 movably arranged on the tumbling device. The tumbling device includes two oppositely arranged support stands 2, and a rotating support beam 4 arranged between the two support stands 2. The rotating support beam 4 is driven to rotate by a rotating motor 41. The stirring tank body 3 is arranged on the rotating support beam 4 and rolls up and down following the rotation of the rotating support beam 4. A buffer rubber layer 11 is arranged on the lower bottom surface of the support base 1. The thickness of the buffer rubber layer 11 is 1 cm, and the buffer rubber layer 11 is hard rubber.

[0026] The vertical cross section of the rotating support beam 4 is a structure with a central rectangle supplemented by semicircular ends. The stirring tank body 3 is provided with a connecting hole 31 that penetrates the stirring tank body 3. The stirring tank body 3 is penetrated on the rotating support beam 4 through the connecting hole 31. The aperture length of the connecting hole 31 is greater than the rod diameter length of the rotating support beam 4, and the difference between the two is 5 cm. A first pushing portion and a second pushing portion are respectively provided near the two end positions in the connecting hole 31. The first pushing portion and the second pushing portion have the same structure. The first pushing portion includes a first pushing rod 311 and a second pushing rod 312 that are arranged opposite to each other, and the second pushing portion includes a third pushing rod 313 and a fourth pushing rod 314 that are arranged opposite to each other. The rotating support beam 4 is provided with a first pushing rod 311 and a second pushing rod 312 that are arranged opposite to each other. The push holes 42 of the rod 312, the third push rod 313 and the fourth push rod 314 cooperate with each other, the first push rod 311 and the fourth push rod 314 move in conjunction with each other, the second push rod 312 and the third push rod 313 move in conjunction with each other, and the first push portion and the second push portion always abut against the rotating support beam 4 during the rotation of the rotating support beam 4, the free ends of the first push rod 311, the second push rod 312, the third push rod 313 and the fourth push rod 314 are all provided with sliding balls 5, the first push rod 311, the second push rod 312, the third push rod 313 and the fourth push rod 314 can all be lifted up and down along their own axial direction, and the up and down lifting method adopts a driving motor to drive the lifting.

[0027] The stirring tank body 3 is provided with a feed inlet 32 and a discharge outlet 33. A central rotating shaft 6 is arranged inside the stirring tank body 3. A first stirring roll group and a second stirring roll group are arranged on the central rotating shaft 6. A diversion guide plate group is arranged on the inner side surface of the stirring tank body. The diversion guide plate group is arranged at the central position of the stirring tank body 3. The diversion guide plate group includes a first annular diversion guide plate 7, a second annular diversion guide plate 71, and a third annular diversion guide plate 72. The number of the first annular diversion guide plate 7 is one. The numbers of the second annular diversion guide plate 71 and the third annular diversion guide plate 72 are both two. The setting method is that with the first annular diversion guide plate 7 as the symmetry center, the second annular diversion guide plate 71 and the third annular diversion guide plate 72 are symmetrically arranged on both sides of the first annular diversion guide plate 7. The surface areas of the first annular diversion guide plate 7, the second annular diversion guide plate 71, and the third annular diversion guide plate 72 decrease in sequence, and all three generate metallic elastic deformation under the action of external force.

[0028] The first stirring roll group includes a first stirring main roll 61 and a first stirring sub-roll 63 which are parallel to each other. The second stirring roll group includes a second stirring main roll 62 and a second stirring sub-roll 64. The first stirring main roll 61 and the second stirring main roll 62 have the same structure. The first stirring sub-roll 63 and the second stirring sub-roll 64 have the same structure and are parallel to each other. A first screen 611 is arranged on the first stirring main roll 61. A second screen 621 is arranged on the second stirring main roll 62. The first screen 611 and the second screen 621 are both perpendicular to the horizontal plane. The first stirring sub-roll 63 and the second stirring sub-roll 64 both extend outwards to overlap with the first annular diversion guide plate 7 in the horizontal plane projection. The first stirring sub-roll 63 and the second stirring sub-roll 64 are respectively located on the upper and lower sides of the first annular diversion guide plate 7. First annular convex portions 73 and second annular convex portions 74 are respectively arranged around the upper and lower side surfaces of the first annular diversion guide plate 7. The first annular convex portion 73 cooperates with the first stirring sub-roll 63, and the second annular convex portion 74 cooperates with the second stirring sub-roll 64 to realize the vibration of the first annular diversion guide plate.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0030] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only one independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing a water-based environmentally friendly paint based on biopolymers, characterized in that: The following steps are involved: S1, raw material pretreatment; soybean oil modification and cellulose hydroxyalkylation, modified into bio-based polymer through ester exchange and hydrolysis processes, to obtain 100-120 parts of bio-based polymer raw materials; S2, emulsion polymerization: adding 3-5 parts of 10-18% methyl methacrylate and 3-5 parts of 10-20% n-butyl acrylate monomer to the bio-based polymer raw material prepared in step S1, and performing emulsion polymerization under the action of 2-4 parts of 0.1-0.3% initiator to generate an acrylic resin emulsion, and then adding 5-8 parts of 0.1-0.8% triisopropanolamine to adjust the pH value of the mixed raw material to 7-8; S3, synthesis of bio-based resin; the first step is to use 100-120 parts of rosin acid as raw material, generate rosin-based polyol and rosin epoxy resin through esterification and epoxidation reaction, and then polycondense with 10-12 parts of polyester prepolymer to form water-based epoxy ester dispersion, and then add 10-12 parts of cellulose nanocrystals to make it composite with the water-based epoxy ester; the second step is to compound 5-8 parts of 70-80% bio-based polyurethane dispersion with 5-8 parts of 40-60% polysiloxane dispersion; and then mix and stir the mixture obtained in the first step with the mixture obtained in the second step; S4, slurry dispersion: 100-120 parts of water, 5-8 parts of 0.1-0.6% dispersant, 5-8 parts of 0.3-0.6% modified silica are added to a dispersion tank, and 10-12 parts of 14-25% heavy calcium and 10-12 parts of 14-20% titanium dioxide extender pigment are added in sequence, and stirred at high speed for 20-40 minutes until uniformly dispersed, and the mixture in step S2 and the mixture in step S3 are added during the stirring process; S5, preparing functional additives; during the stirring process of the slurry dispersion in step S4, 5-8 parts of 0.5-1.5% film-forming additives are added to lower the minimum film-forming temperature, and 5-8 parts of 0.5-5% propylene glycol are added to improve low-temperature stability; S6, filtering and packaging; using a sieve with a mesh size of 200 or above to filter out undispersed particles and impurities in the final mixture after stirring and dispersing in step S5.

2. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 1, characterized in that: The slurry dispersion process in step S4 includes the following subdivision processes: S4.

1. Initial dispersion and stirring: 5-10 minutes before the stirring process, the dispersion tank is kept stationary and the stirring roller in the dispersion tank is only used for stirring in the horizontal direction; S4.2, secondary dispersion stirring: The secondary dispersion stirring begins after the 10th minute of the stirring process. The stirring tank body in the dispersion tank is turned over with the horizontal plane as the reference plane. The turning frequency is 10-15 seconds to complete a complete turning. The stirring rollers in the stirring tank body are stirred in the horizontal and vertical directions simultaneously. The secondary dispersion stirring continues until the end of the stirring process.

3. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 2, characterized in that: The dispersion tank includes a support base, a tumbling device arranged on the support base, and a stirring tank body movably arranged on the tumbling device. The tumbling device includes two oppositely arranged support stands and a rotating support beam arranged between the two support stands. The rotating support beam is driven to rotate by a rotating motor. The stirring tank body is arranged on the rotating support beam and rolls up and down following the rotation of the rotating support beam.

4. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 3, characterized in that: The lower bottom surface of the support base is provided with a buffer rubber layer, the thickness of the buffer rubber layer is 1-3 cm, and the buffer rubber layer is hard rubber.

5. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 4, characterized in that: The vertical cross-section of the rotating support beam is a structure with a central rectangle and semicircular ends, and the mixing tank body is provided with a connecting hole that passes through the mixing tank body, and the mixing tank body is inserted into the rotating support beam through the connecting hole, and the hole diameter length of the connecting hole is greater than the rod diameter length of the rotating support beam, and the first pushing portion and the second pushing portion are respectively provided near the two end positions in the connecting hole, and the first pushing portion and the second pushing portion have the same structure, the first pushing portion includes a first pushing rod and a second pushing rod that are relatively arranged, and the second pushing portion includes a third pushing rod and a fourth pushing rod that are relatively arranged, and the rotating support beam is provided with a pushing hole that cooperates with the first pushing rod, the second pushing rod, the third pushing rod and the fourth pushing rod, the first pushing rod and the fourth pushing rod move in conjunction with each other, and the second pushing rod and the third pushing rod move in conjunction with each other, and during the rotation of the rotating support beam, the first pushing portion and the second pushing portion always abut against the rotating support beam.

6. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 5, characterized in that: The free ends of the first push rod, the second push rod, the third push rod and the fourth push rod are all provided with sliding balls, and the first push rod, the second push rod, the third push rod and the fourth push rod can all be lifted up and down along their own axis directions.

7. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 6, characterized in that: The stirring tank body is provided with a feed inlet and a discharge port, the stirring tank body is provided with a central rotating shaft, the central rotating shaft is provided with a first stirring roller group and a second stirring roller group, the inner side surface of the stirring tank body is provided with a diversion guide plate group, and the diversion guide plate group is provided at the center position of the stirring tank body.

8. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 7, characterized in that: The guide plate group includes a first annular guide plate, a second annular guide plate, and a third annular guide plate. The number of the first annular guide plate is one, and the number of the second annular guide plate and the third annular guide plate are both two. The arrangement is such that the first annular guide plate is used as the center of symmetry, and the second annular guide plate and the third annular guide plate are symmetrically arranged on both sides of the first annular guide plate. The surface areas of the first annular guide plate, the second annular guide plate, and the third annular guide plate decrease in sequence, and all three produce metal elastic deformation under the action of external force.

9. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 8, characterized in that: The first stirring roller group includes a first stirring main roller and a first stirring auxiliary roller which are parallel to each other, the second stirring roller group includes a second stirring main roller and a second stirring auxiliary roller, the first stirring main roller and the second stirring auxiliary roller have the same structure, the first stirring auxiliary roller and the second stirring auxiliary roller have the same structure and are parallel to each other, the first stirring main roller is provided with a first screen, the second stirring main roller is provided with a second screen, and the first screen and the second screen are both perpendicular to the horizontal plane.

10. The method for preparing a water-based environmentally friendly paint based on biopolymer according to claim 9, characterized in that: The first stirring auxiliary roller and the second stirring auxiliary roller both extend outward to overlap with the first annular guide plate in the horizontal plane projection, the first stirring auxiliary roller and the second stirring auxiliary roller are respectively located on the upper and lower sides of the first annular guide plate, and the upper and lower side surfaces of the first annular guide plate are respectively surrounded by a first annular protrusion and a second annular protrusion, the first annular protrusion cooperates with the first stirring auxiliary roller, and the second annular protrusion cooperates with the second stirring auxiliary roller.

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