阅读说明：本技术 一种羟基树脂及其用途 (Hydroxyl resin and application thereof ) 是由 不公告发明人 于 2020-05-22 设计创作，主要内容包括：本发明公开了一种羟基树脂及其用途,属于涂料技术领域,本发明采用了聚丙三醇三缩水甘油醚与虫胶酸反应得到的羟基树脂,再与固化剂4,4’-亚甲基双(异氰酸苯酯)、稀释剂甲基异戊基酮、流平剂环己酮、消泡剂硅油共同混合得到环保喷涂涂料。本发明得到的漆膜的抗冲击性能达到市售涂料的水平,挥发性有机化合物VOC排放量低于国家标准,附着力达到市售涂料水平,同时,本发明还进一步优化得到一种活化时间优于市售涂料且耐磨性能优于市售涂料的环保喷涂涂料。(The invention discloses a hydroxyl resin and application thereof, belonging to the technical field of coatings, and the invention adopts the hydroxyl resin obtained by the reaction of polyglycerol triglycidyl ether and laccaic acid, and then the hydroxyl resin is mixed with a curing agent 4, 4' -methylene bis (phenyl isocyanate), a diluent methyl isoamyl ketone, a flatting agent cyclohexanone and defoaming agent silicone oil to obtain the environment-friendly spraying coating. The impact resistance of the paint film obtained by the invention reaches the level of the commercially available paint, the VOC emission of volatile organic compounds is lower than the national standard, the adhesive force reaches the level of the commercially available paint, and meanwhile, the invention further optimizes the paint film to obtain the environment-friendly spraying paint with the activation time superior to that of the commercially available paint and the wear resistance superior to that of the commercially available paint.)

1. A method of making a hydroxyl resin comprising: reacting polyglycerol triglycidyl ether with laccaic acid under the action of a catalyst to obtain hydroxyl resin; the catalyst is triethylamine.

2. The method for preparing a hydroxyl resin according to claim 1, wherein: the dosage of the laccaic acid is 500 wt% of 350-one of the polyglycerol triglycidyl ether.

3. A hydroxy resin obtainable by the process of any one of claims 1 to 2.

4. Use of the hydroxy resin obtained by the process according to any one of claims 1-2 in the preparation of coatings.

5. Use of the hydroxy resin obtained by the process according to any one of claims 1-2 in the preparation of high solids low viscosity coatings.

6. A preparation method of an environment-friendly spray coating comprises the following steps: mixing the hydroxyl resin and the auxiliary agent according to claim 3, and adding a curing agent to obtain an environment-friendly coating; the auxiliary agent comprises methyl isoamyl ketone serving as a diluent, cyclohexanone serving as a flatting agent and silicone oil serving as a defoaming agent, and the curing agent is polyisocyanate.

7. The preparation method of the environment-friendly spray coating as claimed in claim 6, which is characterized in that: the content of the hydroxyl resin is 46-58 wt%.

8. The preparation method of the environment-friendly spray coating as claimed in claim 6, which is characterized in that: the content of the curing agent isocyanate is 32-44 wt%.

9. The preparation method of the environment-friendly spray coating as claimed in claim 6, which is characterized in that: the content of the auxiliary agent is 10-22 wt%.

10. An environmentally friendly coating obtainable by the process of any one of claims 6 to 9.

Technical Field

The invention belongs to the field of resin synthesis, and particularly relates to a hydroxyl resin and application thereof.

Background

Paint (paint) is a high-strength film which is coated on a coated object and has a certain protection and decoration effect, and the application of the paint is more and more extensive along with the development of the society. The traditional solvent-based paint contains more than 50 percent of organic solvent, and is discharged into the air to pollute the environment and harm the human health in use. With the current laws and regulations, the environmental requirements of the coating are more and more strict. It has become a great trend to develop high solids polyurethane coatings with low VOC emissions.

The polyurethane coating can be divided into a single-component polyurethane coating and a two-component polyurethane coating. The single-component polyurethane coating can be used as soon as being opened when in use, and is convenient to construct, but generally, a film forming material of the coating is linear polyurethane resin, so that the performance is poor; the two-component polyurethane coating needs to be mixed before construction, a film-forming material is usually cross-linked polyurethane resin and has good relative performance, but the film-forming material needs to be prepared for use on site, a certain working life of the product exists, and the unused coating can not be constructed and is wasted after the working life is exceeded. The two-component polyurethane coating mainly comprises two components, namely a hydroxyl resin component A and an isocyanate component B. The viscosity of the existing hydroxyl resin, such as hydroxyl polyester resin and the like, when the solid content is 80 percent, is higher than 20000mPa & s, the construction solid content of the prepared two-component polyurethane coating is as low as 20 percent, the VOC emission in construction is higher than 600g/L, and the new national regulation requirements cannot be met.

In view of the above, there are problems faced up to the development of new hydroxyl resins and to the present level of paint films.

Disclosure of Invention

An object of the present invention is to provide a method for preparing a hydroxyl resin having a high number of functional groups and a low viscosity.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a method of making a hydroxyl resin comprising: reacting polyglycerol triglycidyl ether with laccaic acid under the action of a catalyst to obtain hydroxyl resin; the catalyst is triethylamine. The specific preparation conditions are as follows: and (2) installing a polytetrafluoroethylene stirring rod, a reflux condenser tube and a thermometer on a 250mL three-neck flask, adding laccaic acid, polyglycerol triglycidyl ether and a catalyst triethylamine into the flask, reacting under the nitrogen atmosphere, calibrating an acid value by using a potentiometric titration system in the reaction, stopping the reaction after the acid value is stable and does not decrease any more, and drying the product in vacuum for 1-5h to remove triethylamine and water to obtain the hydroxy resin. The polyglycerol triglycidyl ether has three chains, epoxy groups are arranged on the three chains, the ring opening and the carboxyl on the laccaic acid react to form ester bonds for connection and form hydroxyl groups to obtain hydroxyl resin, and the hydroxyl resin is connected with a molecular structure at the same center through a branched chain and has the characteristics of small molecular weight and low viscosity. Molecules with branched structures and large steric hindrance groups are less prone to entangling than linear molecules and therefore can possess lower viscosities.

Preferably, the catalyst triethylamine is used in an amount of 0.02 to 1 wt%, for example, 0.03, 0.05, 0.08, 0.1, 0.3, 0.35, 0.5, 0.8, 0.95 wt%, of polyglycerol triglycidyl ether, and the catalyst triethylamine may also be used in an amount of 0.02 to 0.8 wt%, 0.3 to 1 wt%, etc., of polyglycerol triglycidyl ether.

Preferably, the amount of laccaic acid is 500 wt%, for example, 360, 380, 400, 420, 450, 460, 490 wt% of the polyglycerol triglycidyl ether, and the amount of laccaic acid can also be 450 wt%, 400-500 wt%, etc. of the polyglycerol triglycidyl ether.

Preferably, the reaction temperature is 110-.

Preferably, the vacuum drying temperature is 120-.

Preferably, the reaction time is 3-10h, e.g., 3, 4, 5, 7, 9, 10 h.

The invention also aims to provide a preparation method of the environment-friendly coating with good impact resistance and low VOC emission of volatile organic compounds.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a preparation method of an environment-friendly spray coating comprises the following steps: mixing hydroxyl resin and an auxiliary agent, and then adding a curing agent to obtain the environment-friendly coating; the auxiliary agent comprises a diluent methyl isoamyl ketone, a flatting agent cyclohexanone and defoaming agent silicone oil, and the curing agent is polyisocyanate. The specific preparation conditions are as follows: adding hydroxyl resin, a diluent methyl isoamyl ketone, defoaming agent silicone oil and a flatting agent cyclohexanone into a dispersion cylinder, placing the dispersion cylinder into a high-speed dispersion machine at room temperature, dispersing the mixture at a high speed of 1500r/min for 10-60min at 600-; and adding the isocyanate curing agent into a dispersion cylinder, dispersing for 5-30min at normal temperature of 100-. The laccaic acid in the hydroxyl resin has a long-chain structure, so that a polymer chain segment can be endowed with good flexibility, and meanwhile, the laccaic acid molecule contains three hydroxyl groups, so that more active sites are provided for the hydroxyl resin. The hydroxyl resin and the curing agent isocyanate react to form amino ester bonds, hydrogen bonds are easily formed among the amino ester bonds, and a compact polymer network is formed through the action of the hydrogen bonds, so that a paint film of the coating has good impact resistance. In addition, the coating prepared from the hydroxyl resin obtained by the invention has high solid content, small solvent addition amount and low VOC emission.

Preferably, the content of the hydroxyl resin is 46 to 58 wt%.

Preferably, the curing agent isocyanate is present in an amount of 32 to 44 weight percent.

Preferably, the addition amount of the auxiliary agent is 10-22 wt%, wherein the content of the diluent methyl isoamyl ketone is 85-95 wt% of the auxiliary agent, the content of the leveling agent cyclohexanone is 4-14 wt%, and the content of the defoaming agent silicone oil is 1-11 wt%.

The invention also aims to provide a preparation method of the environment-friendly coating with good impact resistance, low VOC (volatile organic compound) emission, good adhesive force, long activation time and good wear resistance.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a preparation method of an environment-friendly spray coating comprises the following steps: adding hydroxyl resin, a diluent methyl isoamyl ketone, defoaming agent silicone oil and a flatting agent cyclohexanone into a dispersion cylinder, placing the dispersion cylinder into a high-speed dispersion machine at room temperature, dispersing the mixture at a high speed of 1500r/min for 10-60min at 600-; and adding the curing agent isocyanate, the additive ethyl orthosilicate and the ethyl acrylate into a dispersion cylinder, dispersing for 5-30min at normal temperature of 100-600r/min, stirring uniformly, and standing until no bubbles are generated to obtain the uniformly mixed environment-friendly spraying coating. The additive amount of the hydroxyl resin is 46-58 wt%, the additive amount of the curing agent isocyanate is 32-44 wt%, and the additive amount of the auxiliary agent is 10-22 wt%, wherein the content of the diluent methyl isoamyl ketone is 85-95 wt%, the content of the leveling agent cyclohexanone is 4-14 wt%, and the content of the defoaming agent silicone oil is 1-11 wt%; 1-15 wt% of additive can be added, the addition amount of ethyl orthosilicate in the additive is 40-80 wt%, and the addition amount of ethyl acrylate is 20-60 wt%. The ethyl orthosilicate and the ethyl acrylate are small molecular compounds, have good compatibility with the hydroxyl resin, can be filled between chain segments of molecules, increase the distance and prolong the activation time of the coating; the vacancy is relieved through diffusion, the acting force among the vacancies is weakened, and the internal stress is eliminated, so that the tendency of brittle fracture of the coating is reduced, and the adhesive force of the coating can be effectively increased; when the hydroxyl resin and the isocyanate are subjected to crosslinking curing reaction to form a paint film, the tetraethoxysilane and the ethyl acrylate form a tighter arrangement structure through intermolecular force with the paint film, so that the wear resistance of the paint film is improved.

The hydroxy resin is prepared by polymerizing laccaic acid and polyglycerol triglycidyl ether, so that the hydroxy resin has the following beneficial effects: the hydroxyl resin is in a molecular structure with branched chains connected to the same center, and has the characteristics of small molecular weight and low viscosity; compared with linear molecules, the hydroxyl resin provided by the invention has a branched structure and molecules with large steric hindrance groups, is not easy to wind, and therefore, the hydroxyl resin has lower viscosity. Therefore, the invention is a preparation method of the hydroxyl resin with low viscosity and a large number of functional groups.

The invention adopts the hydroxy resin prepared from laccaic acid and polyglycerol triglycidyl ether, and the coating film is prepared by adding tetraethoxysilane and ethyl acrylate when the coating is cured to form a film, so the invention has the following beneficial effects: the shock resistance of a paint film reaches the level of the commercially available paint, the VOC emission of volatile organic compounds is lower than the national standard, the adhesive force reaches the level of the commercially available paint, the activation time is better than that of the commercially available paint, and the wear resistance is better than that of the commercially available paint. Therefore, the environment-friendly spraying coating has the advantages of good impact resistance, low VOC (volatile organic compound) emission, good adhesive force, long activation time and good wear resistance.

Drawings

FIG. 1 is a graph of viscosity of hydroxy resins at different solids contents;

FIG. 2 is a graph of VOC emissions from coatings;

FIG. 3 is a graph of paint film quality loss.

Detailed Description

The technical solution of the present invention is further described in detail below with reference to the following detailed description and the accompanying drawings: