CN116656237B

CN116656237B - Seal primer for full-closed coating of wood furniture and water-based paint coating method

Info

Publication number: CN116656237B
Application number: CN202310771921.7A
Authority: CN
Inventors: 吴荣江
Original assignee: Jiangmen Weihang Furniture Co ltd
Current assignee: Jiangmen Weihang Furniture Co ltd
Priority date: 2023-06-27
Filing date: 2023-06-27
Publication date: 2024-09-27
Anticipated expiration: 2043-06-27
Also published as: CN116656237A

Abstract

The invention discloses a seal primer for full-closed coating of wood furniture and a water-based paint coating method, wherein the seal primer comprises a cyclic polysiloxane compound and a solvent, and the cyclic polysiloxane compound contains methyl and phenyl groups. The special water-based organic silicon seal primer is designed to replace the existing oil-soluble seal primer and water-based acrylic material seal primer, and the seal primer has the characteristics of high hardness, high permeability, high solid base adhesion, good water resistance, no collapse in later period, safety and environmental protection, achieves the purpose of fully sealing wood gaps and capillaries, and becomes possible for the subsequent full sealing effect. The fully-closed coating process realizes high hardness and high permeability of the product, fully embodies the high-quality appearance image of wood, meets the requirements of qualified products, and has higher commercial value.

Description

Seal primer for full-closed coating of wood furniture and water-based paint coating method

Technical Field

The invention relates to the technical field of furniture spraying, in particular to a seal primer for full-closed coating of wood furniture and a water-based paint coating method.

Background

The prior art mainly uses oil-soluble seal primer to seal a substrate, then uses oil-soluble PE unsaturated polyester to fill thick coating pores and capillaries, uses PU oil-soluble polyurethane transparent primer and finish paint to realize a full-sealing process after polishing, and has the advantages of large smell, excessive VOC emission, serious injury to human body, serious environmental pollution and large potential safety hazard, and is listed in the limit operation. Meanwhile, the product technology is insoluble in water, and can only be dissolved in aromatic hydrocarbon such as toluene, butyl ester, acetone, dimethylbenzene and ketone petrochemical solvents to realize the balance and application of the product, so that the product inevitably has the problems and defects.

In order to solve the problems of the oil paint, a solution exists in the market at present, and the process flow is as follows: the method comprises the steps of water-based acrylic sealing primer polishing, water-based double-component transparent primer polishing, water-based color correction, polishing and water-based double-component finishing coat. The process has the following defects: ① The construction flow is longer, so that the production cost and the time are greatly increased; ② Transparency is inferior to conventional products and processes; ③ The hardness is low, so that the scratch resistance and the abrasion resistance of the product are insufficient; ④ The problem of paint surface collapse exists in the later period, the full-closed effect can not be achieved, and the appearance of the product is affected.

Chinese patent CN113801561a discloses a two-component aqueous coating composition and a wood product by improving a two-component aqueous coating and using it as a three-pass primer (first pass sealer, second pass primer, third pass primer), wherein the two-component aqueous coating comprises: a main agent and an aqueous polyisocyanate curing agent, the main agent comprising a polyol derived from a fatty acid and a polyether modified polysiloxane having a structure comprising a group of C ₁-C₆ alkyl groups (preferably methyl groups) and polyether residues. The patent states that: when the two-component aqueous coating composition is prepared, the combination of the polyol derived from fatty acid and polyether modified polysiloxane has very good compatibility with various types of aqueous curing agents and/or aqueous dispersions of hydroxyl acrylic polymers, the obtained coating composition not only can obtain a coating with high fullness, high transparency and/or high hardness, but also has higher solid content, the VOC content of which is less than 300g/L, and when the two-component aqueous coating composition is used as a seal primer, excellent anti-swelling effect can be achieved. However, since the technical route of this compound determines it has certain limitations, it is specifically as follows: 1. suitable for spray gun atomization, and has lower spray solid content (generally between 40 and 45 percent); 2. the permeability of the paint film is poor; 3. insufficient hardness (typically between 1 and 1.5H); 4. the smell is large, and the VOC content is high.

Disclosure of Invention

The invention aims at: aiming at the problems, the special water-based organic silicon seal primer is designed to replace the existing oil-soluble PE seal primer (large odor) and water-based acrylic material seal primer (low solid content and low hardness), and the seal primer has the characteristics of high hardness, high permeability, high solid base adhesion, good water resistance, no collapse in later period, safety and environmental protection, can achieve the purpose of fully sealing wood gaps and capillaries, and becomes possible to perform full sealing effect later.

The technical scheme adopted by the invention is as follows: the sealing primer for the full-closed coating of the wood furniture is characterized by mainly comprising a methylphenyl organosilicon compound and a solvent, wherein the methylphenyl organosilicon compound contains methyl and phenyl groups at the same time.

In the invention, the methyl phenyl organosilicon compound is preferably synthesized by taking methyl trimethoxy silane and diphenyl dimethoxy silane as main raw materials through hydrolysis-condensation reaction under neutral condition, compared with single organosilicon resin containing methyl groups, the methyl phenyl organosilicon compound has ultrahigh hardness, and meanwhile, certain toughness is also considered, the adhesion to a substrate, mechanical property, optical property and gloss are also greatly improved, and when the organosilicon resin is used as a seal primer, the organosilicon resin has the characteristics of environmental protection, high solid content, low viscosity, ultrahigh hardness, high permeability, high transparency and the like, can fully seal wood gaps and capillaries, and becomes possible for subsequent full sealing effect, which is an effect that cannot be achieved by single organosilicon resin containing methyl and phenyl groups.

Further, the mass ratio of the methylphenyl organosilicon compound to the solvent is 80-120:10-30. The inventor finds that the mass ratio of the sealing primer solvent is not too small or too large, namely the concentration of the polysiloxane compound solution is not too small or too large, and too large can lead some narrow and deep woods of the guide pipe (gap) not to enter so as to cause the condition of a crater, which is not beneficial to filling and leveling; too small a ratio of methyl phenyl organosilicon compound to solvent in the above range is suitable, which results in lower solids content, unfavorable filling of wood voids, too low viscosity of the system, sagging of the system.

Further, the seal coat also comprises an auxiliary agent, wherein the auxiliary agent comprises one or more of a wetting agent, a leveling agent, a defoaming agent, a polishing auxiliary agent and a sagging prevention auxiliary agent. The functional auxiliary agents can be added according to actual needs, and the existing matched auxiliary agents are directly adopted, so that no special requirement is required in the invention. Preferably, the mass fraction of the auxiliary agent is not more than 5%.

Further, the preparation method of the seal primer comprises the following steps:

(1) Adding methyltrimethoxysilane and diphenyldimethoxysilane into a glass reactor with a reflux device, and adding deionized water for hydrolysis reaction under the conditions of 65-75 ℃ and stirring speed of 400-500 r/min;

(2) And after the hydrolysis reaction is finished, heating the reaction system to 150 ℃ for distillation and polycondensation reaction, cooling to 90 ℃ after water and methanol produced by hydrolysis are completely evaporated, adding a solvent to the required solid mass fraction, stirring, and cooling to obtain the catalyst.

Further, the mass ratio of methyltrimethoxysilane to diphenyldimethoxysilane is 10-13:7-10. The mass ratio of methyltrimethoxysilane to diphenyldimethoxysilane is not too large or too small, and according to the experimental results of the applicant, too large ratio can lead to poor hole entering property, too strong paint film rigidity and insufficient toughness. Too small a ratio can lead to the existence of conduit round holes with different degrees at capillary conduit positions on the surface of the wood, insufficient crosslinking points of a paint film, reduced hardness and softer paint film.

Further, ethanol is a renewable resource, and has the characteristics of high drying speed, good permeability and the like, so the ethanol is preferably used as a solvent.

In the present invention, the sealer is used as a substrate sealer, i.e., to seal wood voids and capillaries.

Further, the invention also discloses a method for coating the totally-enclosed water-based paint for the wood furniture, which comprises the following steps:

A. polishing the wood substrate, and then spraying the seal primer;

B. After drying and curing, polishing the paint surface, and spraying a first water-based double-component transparent primer;

C. After drying and curing, polishing the paint surface, and spraying a second aqueous double-component transparent primer;

D. after drying and curing, polishing the paint surface, and spraying an aqueous color-modifying main agent;

E. and (3) after drying and curing, polishing the paint surface, spraying the aqueous double-component finish paint, and drying and curing.

In the invention, the first water-based double-component transparent primer can be prepared from the existing water-based double-component transparent primer, and preferably, the first water-based double-component transparent primer comprises the following components in percentage by mass: aqueous two-component transparent primer: aqueous isocyanate curing agent: water=100:10-15:10-15, preferably in a ratio of 100:12:10; correspondingly, the second aqueous double-component transparent primer can also directly use the existing aqueous double-component transparent primer, and preferably, the mass ratio of the components in the second aqueous double-component transparent primer is as follows: aqueous two-component transparent primer: aqueous isocyanate curing agent: water=100:10-15:10-15, preferably in a ratio of 100:12:10.

Furthermore, the aqueous color-modifying main agent can also adopt the existing aqueous color-modifying main agent, and the mass ratio of each component in the aqueous color-modifying main agent is as follows: aqueous color-modifying main agent: aqueous color extract=100:5-10, for example, it may be 100:5, 100:8, 100:10, etc., and the specific ratio may be selected according to practical situations.

Furthermore, the water-based double-component finishing paint can also adopt the existing water-based double-component finishing paint, and the water-based double-component finishing paint is preferable, wherein the mass ratio of each component in the water-based double-component finishing paint is as follows: aqueous double-component five-component light-splitting finishing paint: aqueous isocyanate curing agent: water=100:10-15:10-15, preferably in a ratio of 100:12:15.

In summary, due to the adoption of the technical scheme, the beneficial effects of the invention are as follows:

1. The special seal primer is used, and has the characteristics of high solid content, good filling property, high hardness, good transparency, good water resistance, no collapse in the later period and the like in the coating process. Thereby realizing the effects of shortening the coating process flow, ensuring good product coating quality, ensuring good product performance and the like, and solving the problems of large smell, ultrahigh VOC content, low hardness, poor transparency, long production process flow, late collapse and the like in the prior oil paint and water paint technical scheme;

2. The full-closed coating process realizes high hardness and high permeability of the product, and fully embodies the high-quality appearance image of the wood. The self-developed seal primer and the self-developed seal primer process are detected by a national furniture product quality supervision and inspection center (Guangdong), meet the requirements of qualified products, and have higher commercial value.

Drawings

FIG. 1 is a graph showing the apparent actual effects of the fiber plates in the walnut paste coated in example 1 of the present invention.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Wood is used as a main material of furniture, has a larger loose structure, is softer in material quality, and has the following characteristics to make a full-sealing effect, namely, the first sealing primer is required to have: ① The viscosity suitable for spraying is favorable for atomizing a spray gun; ② The ultra-high solid content can fully fill wood pores, reduce subsequent processes and improve hardness; ③ The low viscosity and the small molecular weight are beneficial to permeation, the basic fastness is enhanced, and the problem of later collapse is solved; ④ The ultra-high hardness is beneficial to neutralizing soft wood and improving the overall hardness and strength; ⑤ The clear transparency is beneficial to improving the grain definition of the wood, reducing the essential characteristics of the wood and improving the aesthetic feeling and artistic appearance of the product.

In order to achieve the above effects, the invention develops a seal primer, which comprises a polysiloxane compound and a solvent, wherein the polysiloxane compound contains methyl and phenyl groups at the same time, the methyl phenyl organosilicon resin is used as a main raw material, ethanol is used as a main solvent, and the mass ratio of the polysiloxane compound to the solvent is 100:10-30.

Furthermore, the methylphenyl silicone resin can adopt a traditional synthetic route, and the traditional methylphenyl silicone resin mainly adopts two synthetic methods:

First kind: the method is characterized in that a large amount of hydrogen chloride is generated, equipment is easy to corrode, the environment is polluted, the repeated water washing is needed to be neutral, the production cost is high, the production period is long, and the method is not an optimal synthesis method;

Second kind: the method is prepared by using methyltrimethoxysilane, phenyltrimethoxysilane and diphenyldimethoxysilane as raw materials through hydrolysis, water washing, reduced pressure distillation, polycondensation and other methods in the presence of an acid catalyst, and the method requires the use of the acid catalyst, is relatively high in cost, is not friendly to the environment, and is not an optimal synthesis method.

In order to overcome the technical defects of the traditional synthesis method, the invention provides a better synthesis method which takes methyltrimethoxysilane and diphenyldimethoxysilane as main raw materials, and the synthesis process comprises the following steps:

S1, hydrolysis reaction: adding methyltrimethoxysilane and diphenyldimethoxysilane into a glass reactor with a reflux device according to the mass ratio of 13:7, adding 1-1.2 parts by mass of deionized water under the conditions of 65-75 ℃ and stirring speed of 400-500r/min, titrating at the speed of 5mL/min, and stirring for 5 hours;

S2, polycondensation reaction: and (3) heating the reaction system to 150 ℃ for distillation and polycondensation reaction, cooling to 90 ℃ after water and micromolecular methanol produced by hydrolysis are completely evaporated, then adding a solvent (such as dipropylene glycol methyl ether) to the required solid mass fraction, continuously stirring for 20-40 minutes, and cooling to obtain the colorless transparent methyl phenyl silicone resin.

The synthesis method of the invention has the advantages that the evaporated water and methanol have small corrosion effect on equipment, can be collected in a closed way, have small environmental pollution, do not need to use a catalyst, have relatively shorter preparation time, and overcome the problems of the existing synthesis method.

Further, in order to verify the uniqueness of the sealer of the present invention, a series of comparative tests were designed and tested by the inventors using the silicone resin obtained by reacting methyltrimethoxysilane and diphenyldimethoxysilane as a design example and using the conventional main stream product oil sealer and water sealer as a comparative example, as shown in table 1:

table 1 table of formulation of the test sealer

Setting a plurality of test groups by taking a walnut paste medium density fiberboard as a substrate according to the seal coat type of table 1, setting 3 templates (finally taking the average value of three templates) for each test group, sanding the substrate with 240# sand paper along the wood grain direction, spraying the seal coat in table 1 on a bottom plate after soot blowing, and carrying out corresponding paint film performance detection after drying, wherein the detection results are shown in table 2:

TABLE 2 primary properties of the first pass closed paint film of the fiber board in walnut paste

Note that: 1. the test method is mainly tested according to GB/T23999-2009 Water-borne Wood coating for interior decoration.

As can be seen from table 1 above, the primer seal of the present invention has superior transparency in terms of transparency over existing oily primer seals and water-based primer seals; in terms of the manway, the seal primer of the invention has no round eyes at the catheter, whereas the existing oily seal primer and aqueous seal primer have round eyes; in the aspect of later collapse, the existing oily seal primer and water-based seal primer have the collapse time of 90 days and 60 days respectively, and the seal primer has the collapse time of 700 days, which is obviously superior to the existing seal primer. Meanwhile, through comparative examples 1 to 3, when the usage amount of methyltrimethoxysilane is large, the importability is deteriorated, and the later collapse performance is deteriorated, when the usage amount of methyltrimethoxysilane is small, the importability is deteriorated, and the later collapse performance is remarkably deteriorated, which means that the mass ratio of methyltrimethoxysilane to diphenyldimethoxysilane is not too large or too small.

In order to further explain the innovation of the invention, the walnut paste medium density fiberboard is still taken as a substrate, the water-based totally-enclosed five-component dumb effect is realized as an example, and the specific operation flow is as follows:

S1, sanding along the wood grain direction by using 240# sand paper and soot blowing by using medium density fiberboard and walnut skin as materials (40 x 40 cm) in a manual operation mode;

s2, performing manual double-cross spraying by using an organosilicon seal primer (the ratio is methyl phenyl organosilicon seal primer (design example): ethanol=100:20);

s3, sanding along the wood grain direction by using 240# sand paper, flattening the sand, and blowing dust;

S4, manually double-cross spraying a water-based double-component transparent primer (the mass ratio is that the water-based double-component transparent primer (with the trade mark of HD 200) is that a water-based isocyanate curing agent (with the trade mark of G02D) is that water=100:12:10);

s5, sanding along the wood grain direction by using 320# sand paper, flattening the sand, and blowing dust;

s6, manually double-cross spraying a water-based double-component transparent primer (the mass ratio is that the water-based double-component transparent primer (brand HD 200) is water-based isocyanate curing agent (brand G02B) is water=100:12:10);

S7, using 320# sand paper to make coarse sand along the wood grain direction, then using 400# fine sand to make sand level, and blowing ash;

S8, manually spraying an X010 water-based color-modifying main agent (the mass formula is that the water-based color-modifying main agent is that the water-based color concentrate is 100:5-10);

s9, using 600-mesh sponge sand to make the surface particles clear, so as to achieve smoothness and fineness;

s10, manually double-cross spraying water-based double-component finishing paint (the mass ratio of the water-based double-component five-component light-splitting finishing paint (brand HM 225) to water-based isocyanate curing agent (G02B) to water=100:12:15) is obtained.

The process flow chart of the spraying process is shown in table 3:

TABLE 3 Process flow sheet

The effect of the obtained fiber board in the walnut paste is shown in figure 1, and the paint film performance is shown in table 4.

TABLE 4 principal properties of paint films

As can be seen from table 4, by using the coating and coating process of the present invention, high hardness and high permeability of the product are achieved, high quality appearance of wood is fully embodied, and the same process flow and time as those of the oil paint on the market at present are achieved.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. The full-closed water-based paint coating method for the wood furniture is characterized by comprising the following steps of:

A. polishing the wood substrate, and then spraying a seal primer;

E. After drying and curing, polishing the paint surface, spraying water-based double-component finish paint, and drying and curing;

the seal primer mainly comprises methyl phenyl silicone resin and a solvent, wherein the methyl phenyl silicone resin contains methyl and phenyl groups at the same time, and the mass ratio of the methyl phenyl silicone resin to the solvent is 80-120:10-30; the preparation method of the seal coat comprises the following steps:

(1) Adding methyltrimethoxysilane and diphenyldimethoxysilane into a glass reactor with a reflux device, and adding deionized water for hydrolysis reaction under the conditions of 65-75 ℃ and stirring speed of 400-500 r/min; the mass ratio of the methyltrimethoxysilane to the diphenyldimethoxysilane is 13:7;

(2) After the hydrolysis reaction is finished, heating the reaction system to 150 ℃ for distillation and polycondensation reaction, cooling to 90 ℃ after water and methanol generated by hydrolysis are completely evaporated, adding a solvent to the required solid mass fraction, stirring, and cooling to obtain the catalyst;

(3) And adding one or more of a defoaming agent, a wetting agent, a leveling agent, a polishing auxiliary agent and an anti-sagging auxiliary agent into the synthesized methylphenyl organic silicon resin, wherein the mass fraction of the auxiliary agents is not more than 5%, so that the seal primer for full-closed coating is formed.

2. The method for coating the totally-enclosed water-based paint for the wood furniture according to claim 1, wherein the first water-based double-component transparent primer comprises the following components in percentage by mass: aqueous two-component transparent primer: aqueous isocyanate curing agent: water = 100:10-15:10-15; the second aqueous double-component transparent primer comprises the following components in percentage by mass: aqueous two-component transparent primer: aqueous isocyanate curing agent: water=100:10-15:10-15.

3. The method for coating the totally-enclosed water-based paint for the wood furniture according to claim 2, wherein the water-based color-modifying main agent comprises the following components in percentage by mass: aqueous color-modifying main agent: aqueous color extract = 100:5-10.

4. The method for coating the totally-enclosed water-based paint for the wood furniture according to claim 3, wherein the water-based double-component finish paint comprises the following components in percentage by mass: aqueous double-component five-component light-splitting finishing paint: aqueous isocyanate curing agent: water=100:10-15:10-15.