阅读说明：本技术 多元改性氨基树脂、其制备方法与应用 (Multi-element modified amino resin, preparation method and application thereof ) 是由 刘慧� 于 2021-08-13 设计创作，主要内容包括：一种多元改性氨基树脂、其制备方法与应用,属于涂料技术领域。该多元改性氨基树脂的制备方法将有机硅中间体、环氧树脂、催化剂和溶剂加入反应釜中搅拌均匀,之后加热至回流反应,得到硅改性环氧树脂低聚物；回流反应完全后,加入低醚化氨基树脂和溶剂,继续反应,制得多元改性氨基树脂。本发明能够提高氨基树脂的耐高温性能、附着力和耐磨性。(A multi-element modified amino resin, a preparation method and an application thereof belong to the technical field of coatings. Adding an organic silicon intermediate, epoxy resin, a catalyst and a solvent into a reaction kettle, uniformly stirring, and then heating to reflux reaction to obtain a silicon modified epoxy resin oligomer; and after the reflux reaction is completed, adding the low-etherification amino resin and the solvent, and continuing the reaction to prepare the multi-element modified amino resin. The invention can improve the high temperature resistance, adhesive force and wear resistance of the amino resin.)

1. A preparation method of multi-element modified amino resin is characterized in that an organic silicon intermediate, epoxy resin, a catalyst and a solvent are added into a reaction kettle and uniformly stirred, then the mixture is heated to reflux reaction, and after the reaction is completed, a silicon modified epoxy resin oligomer is obtained; and then adding low-etherification amino resin and a solvent, and continuing reflux reaction to obtain the multi-element modified amino resin.

2. The preparation method according to claim 1, wherein the weight ratio of the silicon-modified epoxy resin oligomer to the oligoetherized amino resin is 10 to 40: 60-90 parts of; preferably, the weight ratio is 30: 70.

3. the method according to claim 1, wherein the weight ratio of the silicone intermediate to the epoxy resin is 2: 1.

4. The process according to claim 1, wherein the reflux reaction is carried out at a temperature of 130 ℃ to obtain the silicon-modified epoxy resin oligomer having a solid content of 60%.

5. The preparation method of the low-etherified amino resin as claimed in claim 1, wherein the low-etherified amino resin is synthesized by using xylene, butanol, melamine and solid formaldehyde under the action of a catalyst; preferably, the solid content of the oligoetherified amino resin is 60%.

6. The process according to claim 5, wherein the temperature of the reaction mixture for refluxing to obtain the polybasic modified amino resin is 130 ℃.

7. The method of claim 1, wherein the intermediate comprises at least one of dow corning 232, wacker 3074, shin yue KR213, shin yue KR211, and dow corning 618.

8. The method of claim 1, wherein the epoxy resin comprises at least one of epoxy 6101, epoxy 601, and epoxy 604.

9. A multi-component modified amino resin, characterized in that it is produced by the production method according to any one of claims 1 to 8.

10. Use of the multiple modified amino resin according to claim 9 in abrasion resistant high temperature coatings.

Technical Field

The invention relates to a technology in the field of coatings, in particular to a multi-element modified amino resin, a preparation method and application thereof.

Background

The amino resin for paint is a polymerization product of a compound with an amino group and aldehydes which react and are modified by alcohols so that the amino resin can be dissolved in an organic solvent. It is the most important cross-linking agent in thermosetting paint, and the amino resin has high light and color maintaining performance and high weather resistance, and may be used widely in automobile paint and small household appliance paint.

For small household electrical appliance coating, amino resin, polyester, pigment, auxiliary agent, solvent and the like are generally mixed and coated, and finally, the coating is formed by high-temperature baking. However, in the high-temperature baking process, the defects that the amino resin turns yellow and the adhesive force is reduced and cannot reach grade 1 and the like easily occur, and the wear resistance of the amino resin is poor, so that the requirements of part of customers cannot be met.

The present invention has been made to solve the above-mentioned problems occurring in the prior art.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a multi-element modified amino resin, a preparation method and application thereof, and the high temperature resistance, the adhesive force and the wear resistance of the amino resin can be improved.

The first aspect of the invention provides a preparation method of a multi-element modified amino resin, which comprises the steps of adding an organic silicon intermediate, epoxy resin, a catalyst and a solvent into a reaction kettle, uniformly stirring, heating to reflux reaction, and obtaining a silicon modified epoxy resin oligomer after the reaction is completed; and then adding low-etherification amino resin and a solvent, and continuing reflux reaction to obtain the multi-element modified amino resin.

The weight ratio of the silicon modified epoxy resin oligomer to the low etherified amino resin is 10-40: 60-90 parts of; preferably, the weight ratio is 30: 70.

the weight ratio of the organosilicon intermediate to the epoxy resin is 2:1, and the weight ratio of the catalyst to the epoxy resin is 0.0001-0.1: 1.

The temperature of the silicon modified epoxy resin oligomer prepared by the reflux reaction is 130 ℃, and the reaction time is preferably 2 h; the solid content of the obtained silicon-modified epoxy resin oligomer was 60%.

The low-etherification amino resin is synthesized by dimethylbenzene, butanol, melamine and solid formaldehyde under the action of a catalyst. Preferably, the solid content of the oligoetherified amino resin is 60%.

The temperature of the multi-element modified amino resin prepared by reflux reaction is 130 ℃, and the reaction time is preferably 1 h.

The intermediate includes at least one of dow corning 232, wacker 3074, shin yue KR213, shin yue KR211, and dow corning 618.

The epoxy resin includes at least one of epoxy 6101, epoxy 601, and epoxy 604.

The second aspect of the invention provides a multi-element modified amino resin which is prepared by the preparation method.

The third aspect of the invention provides the application of the multi-element modified amino resin in wear-resistant high-temperature coatings.

The third aspect of the invention provides an application of a multi-element modified amino resin in wear-resistant high-temperature coatings.

Technical effects

Compared with the prior art, the invention has the following technical effects:

1) by introducing the silicon element into the amino resin, the temperature resistance and the wear resistance of the amino resin are improved, the surface tension of the amino resin is reduced, and the adhesion of the amino resin to a substrate is facilitated; meanwhile, the wear resistance and the adhesive force of the modified amino resin are improved by grafting the epoxy resin to the amino resin;

2) through the reaction of hydroxyl of epoxy resin and methoxyl of organosilicon intermediate, methanol is removed, oligomer is obtained, and then methoxyl in the oligomer reacts with hydroxymethyl of amino resin to remove methanol, and multi-modified amino resin is obtained, so that the difficulty of multi-modification of amino resin by organosilicon and epoxy resin is reduced, the process is simple, and the control is convenient;

3) by combining the selection of the wear-resistant pigment and filler, the high-temperature coating with good temperature resistance, good wear resistance and good adhesion to metal substrates can be developed.

Detailed Description

The present invention will be described in detail with reference to specific embodiments. The experimental procedures, in which specific conditions are not specified in the examples, were carried out according to the conventional methods and conditions.

Example 1

This example relates to the preparation of a multiple modified amino resin, as follows.

The raw materials used are shown in table 1 below:

TABLE 1 multicomponent modified amino resin raw materials

Raw materials	Manufacturer(s)
		Butylated amino groupResin composition	Self-made
Epoxy resin 671-75	Dow of America
		Organosilicon intermediates 237	American national standard Kangning
Catalyst isopropyl titanate	French Rodiya
		Xylene	Industrial grade
Butanol	Industrial grade

The preparation process comprises the following steps: adding 671-75 epoxy resin, 237 organosilicon intermediate and catalyst isopropyl titanate into a reaction kettle provided with a thermometer, a condenser and a stirrer, and adding xylene and butanol as solvents; then evenly stirring, heating to the reflux temperature of 130 ℃, and keeping the temperature for reaction for 2 hours; and then adding butylated amino resin, xylene and butanol, continuing to perform heat preservation reaction for 3 hours, and filtering the reaction solution to obtain the multielement modified amino resin. The technical indexes of the obtained multi-element modified amino resin are shown in Table 2.

TABLE 2 technical indices of the multicomponent modified amino resins

The embodiment also relates to a high-temperature-resistant wear-resistant coating prepared from the multi-element modified amino resin, and the specific process is as follows.

TABLE 3 high-temp. and abrasion resistant coating raw materials

Composition of	Manufacturer(s)	Weight ratio/%
			Multi-modified amino resin	Self-made	20
Polyester resin 370	All-grass of Jiangsu Sanmu	40
			Titanium dioxide R902	Dupont USA	25
Dispersant EFKA4010	Pasf Germany	0.5
			Leveling agent EFKA3777	Pasf Germany	1
Precipitated barium sulfate (800 mesh)	Hangzhou Fengshou large	5
			Anti-settling agent SD-1	American sea celebrity	0.5
Diluent XB-8	Self-made	8

The preparation process comprises the following steps: according to the raw material proportion shown in table 3, all the raw materials except the multi-element modified amino resin and the leveling agent are put into a dispersion kettle, and then are stirred and mixed uniformly; adding a certain amount of pigment and filler in the stirring process to prepare the coating with the required color; after uniform dispersion, grinding the mixture by a sand mill until the fineness is qualified (less than or equal to 30 mu m), then introducing the mixture into a dispersion kettle, adding the multi-element modified amino resin and the flatting agent into the dispersion kettle, dispersing the mixture at a high speed for 30 minutes, and filtering the mixture to obtain the high-temperature-resistant and wear-resistant coating.

The high temperature resistant and wear resistant coating K-2 prepared by the method is tested, unmodified amino resin K-1 is taken as a comparative example, the two are respectively coated on two same aluminum plates, and the two are baked for 30 minutes at 200 ℃ to test the performance of the coating; the sheets were then boiled in boiling water at 100 ℃ for 1 hour and compared for properties as shown in Table 4. The adhesive force and the wear resistance of the K-2 coating after water resistance are better than the performance of a K-1 coating after water resistance, because the hydrophobic property and the wet adhesive force of the modified amino resin are enhanced due to the introduction of the organosilicon intermediate and the epoxy resin.

TABLE 4 comparison of coating film properties

Compared with the non-modified amino resin, the wear resistance, the adhesive force and the yellowing property of the organosilicon intermediate and the epoxy resin modified amino resin are obviously improved, and the high-temperature coating prepared by the organosilicon intermediate has better adhesive force to a metal substrate, beautiful appearance and durable product compared with the conventional amino high-temperature coating.

The effect of the amount of silicone intermediate and the amount of epoxy resin used in the preparation of the multi-element modified amino resin of this example are compared as follows.

I. Influence of the amount of organosilicon intermediate used

Three kinds of amino resin A-1, A-2 and A-3 are set, A-1 is not modified, the dosage of the organosilicon intermediate in the preparation process of A-2 accounts for 20 percent of the total weight of the raw materials, the dosage of the organosilicon intermediate in the preparation process of A-3 accounts for 30 percent of the total weight of the raw materials, and the performance indexes of the three kinds of resin are shown in Table 5.

TABLE 5 Effect of amount of organosilicon intermediate on resin Properties

As can be seen from Table 5, when the amount of the organosilicon intermediate used was 20%, the yellowing resistance was solved and the abrasion resistance was improved. The surface energy of the organosilicon intermediate is low, and the surface tension of the grafted copolymer is reduced, so that the interfacial tension of a coating and a substrate is reduced, the adhesion area is increased, the adhesion to a metal substrate is improved, and the key point of improving the wear resistance is to introduce a silicon-oxygen group.

Effect of epoxy resin dosage

Setting four kinds of amino resin B-1, B-2, B-3 and B-4, wherein B-1 is not modified, the amount of the epoxy resin B-2 in the preparation process accounts for 5% of the total weight of the raw materials, the amount of the epoxy resin B-3 in the preparation process accounts for 10% of the total weight of the raw materials, the amount of the epoxy resin B-4 in the preparation process accounts for 15% of the total weight of the raw materials, and the performance indexes of the four kinds of resin are shown in Table 6.

TABLE 6 Effect of epoxy resin amount on resin Properties

It can be seen from table 6 that, when the epoxy resin is grafted to the amino resin, the wear resistance and adhesion are significantly improved with the increase of the amount of the epoxy resin, and when the amount of the epoxy resin is greater than 15%, the modification effect is not significant when the amount of the epoxy resin is too small, preferably, the amount of the epoxy resin is 8% -12%, because the grafting activity is more, the branching degree is greater, the molecular chain entanglement is severe, the viscosity of the base resin is increased and the base resin is gelled after the reaction.

It is to be emphasized that: the above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and all simple modifications, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.