阅读说明：本技术 一种有机硅改性环氧衣康酸酯树脂水分散体的制备方法 (Preparation method of organic silicon modified epoxy itaconate resin aqueous dispersion ) 是由 吴国民 边均娜 孔振武 陈健 杨兆哲 于 2021-06-21 设计创作，主要内容包括：本发明公开了一种有机硅改性环氧衣康酸酯树脂水分散体及其制备方法。将一定量的卡斯特催化剂加入环氧衣康酸酯树脂的异丙醇溶液中,加热搅拌温度升至50-70℃,缓慢滴加一定量的端氢聚硅氧烷,升温至异丙醇回流温度继续反应6-8h,减压蒸馏回收异丙醇,得到聚硅氧烷改性环氧衣康酸酯。再将聚硅氧烷改性环氧衣康酸酯溶于丙酮,按物质的量比1︰1加入半封端异氰酸酯,搅拌升温至丙酮回流温度,反应6-8h,经碱中和、水分散、蒸除丙酮后,得到有机硅改性环氧衣康酸酯树脂水分散体。本发明既降低了光固化树脂中低活性双键的比例,又提高了光固化漆膜的柔韧性和耐水性。(The invention discloses an organic silicon modified epoxy itaconate resin aqueous dispersion and a preparation method thereof. Adding a certain amount of a Caster catalyst into an isopropanol solution of epoxy itaconate resin, heating and stirring to 50-70 ℃, slowly dropwise adding a certain amount of hydrogen-terminated polysiloxane, heating to the isopropanol reflux temperature, continuing to react for 6-8h, and recovering isopropanol through reduced pressure distillation to obtain polysiloxane-modified epoxy itaconate. And dissolving polysiloxane modified epoxy itaconate in acetone, adding half-blocked isocyanate according to the mass ratio of 1: 1, stirring and heating to the acetone reflux temperature, reacting for 6-8h, and performing alkali neutralization, water dispersion and acetone evaporation to obtain the organosilicon modified epoxy itaconate resin aqueous dispersion. The invention not only reduces the proportion of low-activity double bonds in the photo-curing resin, but also improves the flexibility and the water resistance of the photo-curing paint film.)

1. A preparation method of an organosilicon modified epoxy itaconate resin aqueous dispersion is characterized by comprising the following steps:

adding a Caster catalyst into an isopropanol solution of epoxy itaconate resin, heating and stirring to 50-70 ℃, dropwise adding hydrogen-terminated polysiloxane, heating to isopropanol reflux temperature, continuing to react for 6-8h, carrying out reduced pressure distillation to recover isopropanol to obtain polysiloxane modified epoxy itaconate, dissolving the polysiloxane modified epoxy itaconate in acetone, adding semi-blocked isocyanate according to the mass ratio of 1: 1, stirring and heating to acetone reflux temperature, reacting for 6-8h, neutralizing with alkali, carrying out water dispersion, and evaporating to remove acetone to obtain the organosilicon modified epoxy itaconate resin aqueous dispersion.

2. The method for preparing the aqueous dispersion of silicone-modified epoxy itaconate resin according to claim 1, wherein the epoxy itaconate resin is an esterification product of epoxy resin and itaconic acid, wherein the esterification product has carboxyl groups at both ends, and is produced by reacting the epoxy resin and itaconic acid at a mass ratio of 1: 2.

3. The method of preparing the aqueous dispersion of silicone-modified epoxy itaconate resin of claim 1, wherein the hydrogen-terminated polysiloxane is a polysiloxane containing silicon-hydrogen bonds at terminal positions.

4. The method for preparing the aqueous dispersion of silicone-modified epoxy itaconate resin according to claim 1, wherein the half-blocked isocyanate is a product of reacting diisocyanate and hydroxy (meth) acrylate at a mass ratio of 1: 1 under acetone reflux conditions for 4 hours to produce an isocyanate group at one end and a (meth) acryloxy group at the other end.

5. The method for preparing the aqueous dispersion of silicone-modified epoxy itaconate resin of claim 4, wherein the diisocyanate is any one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate.

6. The method for preparing the aqueous dispersion of silicone-modified epoxy itaconate resin of claim 4, wherein the hydroxy (meth) acrylate is any one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate and 4-hydroxybutyl acrylate.

Technical Field

The invention relates to an organic silicon modified epoxy itaconate resin aqueous dispersion and a preparation method thereof, in particular to an organic silicon modified epoxy itaconate resin aqueous dispersion grafted with semi-blocked isocyanate and a preparation method thereof.

Background

The water-based photocuring epoxy coating takes water as a dispersion medium, has the advantages of safety, high efficiency, environmental protection and the like, but the unmodified water-based epoxy photocuring resin has the defects of high brittleness, poor flexibility, easiness in being influenced by water and the like, and the application of the unmodified water-based epoxy photocuring resin in the field of high-performance coatings is limited. Polysiloxane polymers are composed of repeating Si-O bonds with organic groups directly attached to the backbone silicon atoms. The special physical and chemical structure enables the polysiloxane polymer to be used for producing high polymer materials with good weather resistance, excellent hydrophobic property and stain resistance, and can be widely applied to the fields of electronics, military industry, aerospace, buildings and the like. Chemical modification is the most commonly used effective method for modifying photocuring resin by organic silicon, and the preparation method of the polysiloxane chemical modification photocuring resin comprises a hydrosilylation method, an esterification method, a hydrolytic condensation method, a free radical addition method and the like.

The modified resin is prepared by the addition polymerization of the photocuring resin and polysiloxane oligomer with reactive functional groups at two ends, and the obtained modified resin combines the photocuring resin and organic silicon in a chemical bonding mode, so that the polysiloxane chain segment has good compatibility with a resin matrix. Zhouxing and the like use polybutylene adipate diol and isophorone diisocyanate as main raw materials to carry out polycondensation, react with 2, 2-dimethylolpropionic acid (DMPA) to introduce hydrophilic group carboxyl, then mix with pentaerythritol triacrylate and hydroxyethyl acrylate to carry out end capping to prepare a series of waterborne UV curing urethane acrylate (WPUA), and introduce hydroxyl-terminated polydimethylsiloxane into a WPUA molecular chain, thereby effectively improving the hydrophobicity and the water resistance of a paint film. A series of organic silicon modified water-based UV-cured polyurethane resins are prepared by isophorone diisocyanate, polycarbonate diol, hydroxyl-terminated polydimethylsiloxane, DMPA and 2-hydroxyethyl methacrylate, and the contact angle of a paint film is increased to 104.7 degrees from 69.2 degrees before unmodified due to the introduction of organic silicon. According to the invention, the silicon-terminated hydrogen polysiloxane modified epoxy itaconate resin is utilized, and polysiloxane chain segments continuously migrate and enrich to the surface in the curing process of forming a paint film, so that the surface tension of the paint film can be reduced, and the hydrophobic property is improved; and the flexible chain segment in the organic silicon is grafted and copolymerized into the matrix resin, so that the defects of poor flexibility and the like of the photocuring epoxy coating can be effectively improved.

Disclosure of Invention

The invention aims to provide an organosilicon modified epoxy itaconate resin aqueous dispersion and a preparation method thereof. The method comprises the steps of carrying out hydrosilylation reaction on double bonds with low photocuring activity in epoxy itaconate resin and polysiloxane containing silicon-hydrogen bonds at end positions under the catalysis of a Kanster catalyst to synthesize organic silicon modified epoxy itaconate resin, and grafting with semi-blocked isocyanate with one end being (methyl) acryloyloxy to prepare the organic silicon modified epoxy itaconate resin aqueous dispersion. By means of organic silicon modification, the proportion of low-photocuring active double bonds in the epoxy itaconate resin is reduced, and the flexibility and the water resistance of the photocuring paint film are improved.

The technical scheme of the invention is as follows: a preparation method of an organosilicon modified epoxy itaconate resin aqueous dispersion is realized by the following steps:

adding a Caster catalyst into an isopropanol solution of epoxy itaconate resin, heating and stirring to 50-70 ℃, dropwise adding hydrogen-terminated polysiloxane, heating to isopropanol reflux temperature, continuing to react for 6-8h, carrying out reduced pressure distillation to recover isopropanol to obtain polysiloxane modified epoxy itaconate, dissolving the polysiloxane modified epoxy itaconate in acetone, adding semi-blocked isocyanate according to the mass ratio of 1: 1, stirring and heating to acetone reflux temperature, reacting for 6-8h, neutralizing with alkali, carrying out water dispersion, and evaporating to remove acetone to obtain the organosilicon modified epoxy itaconate resin aqueous dispersion.

The epoxy itaconate resin is an esterification product which is generated by the reaction of epoxy resin and itaconic acid according to the mass ratio of 1: 2 and has carboxyl at both ends.

The hydrogen-terminated polysiloxane refers to polysiloxane containing silicon-hydrogen bonds at terminal positions.

The semi-blocked isocyanate is a product which is generated by reacting diisocyanate and (methyl) acrylic acid hydroxy ester according to the mass ratio of 1: 1 under the acetone reflux condition for 4 hours, wherein one end of the product is isocyanate group, and the other end of the product is (methyl) acryloyloxy group.

The diisocyanate is any one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and hydrogenated diphenylmethane diisocyanate.

The (methyl) acrylic acid hydroxyl ester refers to any one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate and 4-hydroxybutyl acrylate.

Advantageous effects

According to the invention, the compound modification of the organic silicon and the epoxy itaconate ester resin is realized by utilizing the reaction of the low-photocuring-activity double bonds in the epoxy itaconate ester resin and the polysiloxane containing silicon hydrogen bonds, so that the proportion of the low-activity double bonds in the photocuring resin is reduced, and the flexibility and the water resistance of the photocuring paint film are improved.

Drawings

FIG. 1 is a graph showing the effect of polysiloxane dosage on the hydrophobic properties of half-blocked isocyanate epoxy itaconate resin paint films. The contact angle of the surface of the paint film is increased along with the increase of the consumption of the polysiloxane, and when the consumption of the polysiloxane is 1%, 3%, 5%, 7% and 9%, the contact angles corresponding to the surface of the paint film are 77.69 degrees, 84.88 degrees, 90.81 degrees, 94.43 degrees and 96.48 degrees respectively. With the increase of the amount of the polysiloxane, the water absorption of the paint film is remarkably reduced, and the water absorption is reduced from 17.88% when the amount of the polysiloxane is 1% to 8.22% when the amount of the polysiloxane is 9%. It is demonstrated that the incorporation of polysiloxane segments results in an increase in the hydrophobic properties of the polymer paint film.

FIG. 2 shows FT-IR spectra of hydrogen-terminated polysiloxane and epoxy itaconate resin before and after modification. The infrared spectrum of the hydrogen-terminated polysiloxane shows that the molecular weight is 2965cm^-1Is represented by-CH₃Has an antisymmetric telescopic vibration absorption peak of 2126cm^-1A stretching vibration peak of Si-H bond at 1240cm^-1(Si-CH₃)、1010cm^-1(-Si-O-Si)、785cm^-1The signal peak at (-Si-C) is the characteristic absorption peak of siloxane. The infrared spectrogram of the modified epoxy itaconate resin is compared, and the modified product is 1240cm^-1Is out ofNow Si-CH₃Characteristic absorption peak of (1), 785cm^-1The characteristic absorption peak of-Si-C appears, and the existence of-Si-O-Si makes 1010cm^-1The absorption peak becomes broader and stronger. The modified epoxy itaconate resin is at 1640cm due to partial double bonds consumed by hydrosilylation^-1The characteristic absorption peak of the double bond is slightly reduced in intensity, 2126cm^-1The stretching vibration absorption peak of the terminal Si-H bond completely disappears after the reaction is finished, which indicates that the Si-H bond of the hydrogen-terminated polysiloxane in the system is completely reacted.

Detailed Description

A preparation method of an organosilicon modified epoxy itaconate resin aqueous dispersion is realized by the following steps:

adding a Caster catalyst into an isopropanol solution of epoxy itaconate resin, heating and stirring to 50-70 ℃, dropwise adding a certain amount of hydrogen-terminated polysiloxane, heating to the isopropanol reflux temperature, continuing to react for 8 hours, and carrying out reduced pressure distillation to recover isopropanol to obtain polysiloxane-modified epoxy itaconate.

Dissolving polysiloxane modified epoxy itaconate in acetone, adding half-blocked isocyanate according to the mass ratio of 1: 1, stirring and heating to acetone reflux temperature, reacting for 6-8h, neutralizing with alkali, dispersing in water, and evaporating to remove acetone to obtain the organosilicon modified epoxy itaconate resin aqueous dispersion.

The epoxy itaconate resin is an esterification product which is generated by the reaction of epoxy resin and itaconic acid according to the mass ratio of 1: 2 and has carboxyl at both ends.

The hydrogen-terminated polysiloxane refers to polysiloxane containing silicon-hydrogen bonds at terminal positions.

The semi-blocked isocyanate is a product which is generated by reacting diisocyanate and (methyl) acrylic acid hydroxy ester according to the mass ratio of 1: 1, wherein one end of the product is isocyanate group, and the other end of the product is (methyl) acryloxy. The diisocyanate is any one or more of toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and hydrogenated diphenylmethane diisocyanate. The (methyl) acrylic acid hydroxyl ester refers to any one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate and 4-hydroxybutyl acrylate.

Comparative example 1

222.0g of isophorone diisocyanate, 144.0g of 4-hydroxybutyl acrylate and 366.0g of acetone were put into a four-necked flask equipped with a thermometer, a stirrer and a condenser, and then heated to the acetone reflux temperature with stirring to react for 6 hours, thereby obtaining an acetone solution (solid content: 50 wt%) of a half-blocked isocyanate intermediate.

And slowly dropwise adding 74.9g of acetone solution (solid content is 50 wt%) of the semi-blocked isocyanate intermediate into 100.0g of epoxy itaconate resin acetone solution (solid content is 66.7 wt%), stirring and heating to the acetone reflux temperature, and reacting for 6 hours to obtain the IPDI type semi-blocked isocyanate modified epoxy itaconate resin. Adding 24.0g of triethanolamine for neutralization, and continuing the reflux reaction for 0.5 h. Slowly dripping distilled water, stirring and dispersing to obtain an aqueous dispersion with the solid content of 60 wt%, and carrying out reduced pressure distillation to recover acetone to obtain the modified epoxy itaconate resin aqueous dispersion. The mechanical properties of the resin photo-curable lacquer film are shown in table 1.

Example 1

Adding 100.0g of epoxy itaconate resin, 0.004g of Kanster catalyst containing platinum and 30.0g of isopropanol into a four-mouth bottle provided with a thermometer, a stirrer and a condenser, heating and stirring uniformly, raising the temperature to 70 ℃, slowly dripping 1.0g of hydrogen-terminated polysiloxane, raising the temperature to 90 ℃ (the reflux temperature of the isopropanol), continuing to react for 8 hours, and carrying out reduced pressure distillation to recover the isopropanol to obtain the polysiloxane-modified epoxy itaconate.

And slowly dropwise adding 74.9g of acetone solution (solid content is 50 wt%) of the semi-blocked isocyanate intermediate into 101.0g of polysiloxane modified epoxy itaconate acetone solution (solid content is 66.7 wt%), stirring and heating to the acetone reflux temperature, and reacting for 6 hours to obtain the semi-blocked isocyanate polysiloxane modified epoxy itaconate resin. Adding 24.0g of triethanolamine for neutralization, and continuing the reflux reaction for 0.5 h. Slowly dripping distilled water, stirring and dispersing to obtain an aqueous dispersion with the solid content of 60 wt%, and carrying out reduced pressure distillation to recover acetone to obtain the polysiloxane modified epoxy itaconate resin aqueous dispersion. The water absorption and mechanical properties of the resin photo-curable lacquer film are shown in fig. 1 and table 1.

Example 2

Adding 100.0g of epoxy itaconate resin, 0.004g of Kanster catalyst containing platinum and 30.0g of isopropanol into a four-mouth bottle provided with a thermometer, a stirrer and a condenser, heating and stirring uniformly, raising the temperature to 70 ℃, slowly dripping 3.0g of hydrogen-terminated polysiloxane, raising the temperature to 90 ℃ (the reflux temperature of the isopropanol), continuing to react for 8 hours, and carrying out reduced pressure distillation to recover the isopropanol to obtain the polysiloxane-modified epoxy itaconate.

And (3) slowly dropwise adding 74.9g of acetone solution (solid content is 50 wt%) of the semi-blocked isocyanate intermediate into 103.0g of polysiloxane modified epoxy itaconate acetone solution (solid content is 66.7 wt%), stirring and heating to acetone reflux temperature, and reacting for 6 hours to obtain the semi-blocked isocyanate polysiloxane modified epoxy itaconate resin. Adding 24.0g of triethanolamine for neutralization, and continuing the reflux reaction for 0.5 h. Slowly dripping distilled water, stirring and dispersing to obtain an aqueous dispersion with the solid content of 60 wt%, and carrying out reduced pressure distillation to recover acetone to obtain the polysiloxane modified epoxy itaconate resin aqueous dispersion. The water absorption and mechanical properties of the resin photo-curable lacquer film are shown in fig. 1 and table 1.

Example 3

100.0g of epoxy itaconate resin, 0.004g of Kanster catalyst containing platinum and 30.0g of isopropanol are added into a four-mouth bottle provided with a thermometer, a stirrer and a condenser, the mixture is heated and stirred uniformly, the temperature is raised to 70 ℃, 5.0g of hydrogen-terminated polysiloxane is slowly dripped, the temperature is raised to 90 ℃ (the reflux temperature of the isopropanol), the reaction is continued for 8 hours, and the isopropanol is recovered by reduced pressure distillation, so that the polysiloxane modified epoxy itaconate is obtained.

And slowly dripping 74.9g of acetone solution (solid content is 50 wt%) of the semi-blocked isocyanate intermediate into 105.0g of polysiloxane modified epoxy itaconate acetone solution (solid content is 66.7 wt%), stirring and heating to the acetone reflux temperature, and reacting for 6 hours to obtain the semi-blocked isocyanate polysiloxane modified epoxy itaconate resin. Adding 24.0g of triethanolamine for neutralization, and continuing the reflux reaction for 0.5 h. Slowly dripping distilled water, stirring and dispersing to obtain an aqueous dispersion with the solid content of 60 wt%, and carrying out reduced pressure distillation to recover acetone to obtain the polysiloxane modified epoxy itaconate resin aqueous dispersion. The water absorption and mechanical properties of the resin photo-curable lacquer film are shown in fig. 1 and table 1.

Example 4

100.0g of epoxy itaconate resin, 0.004g of Kanster catalyst containing platinum and 30.0g of isopropanol are added into a four-mouth bottle provided with a thermometer, a stirrer and a condenser, the mixture is heated and stirred uniformly, the temperature is raised to 70 ℃, 7.0g of hydrogen-terminated polysiloxane is slowly dripped, the temperature is raised to 90 ℃ (the reflux temperature of the isopropanol), the reaction is continued for 8 hours, and the isopropanol is recovered by reduced pressure distillation, so that the polysiloxane modified epoxy itaconate is obtained.

And slowly dropwise adding 74.9g of acetone solution (solid content is 50 wt%) of the semi-blocked isocyanate intermediate into 107.0g of polysiloxane modified epoxy itaconate acetone solution (solid content is 66.7 wt%), stirring and heating to the acetone reflux temperature, and reacting for 6 hours to obtain the semi-blocked isocyanate polysiloxane modified epoxy itaconate resin. Adding 24.0g of triethanolamine for neutralization, and continuing the reflux reaction for 0.5 h. Slowly dripping distilled water, stirring and dispersing to obtain an aqueous dispersion with the solid content of 60 wt%, and carrying out reduced pressure distillation to recover acetone to obtain the polysiloxane modified epoxy itaconate resin aqueous dispersion. The water absorption and mechanical properties of the resin photo-curable lacquer film are shown in fig. 1 and table 1.

Example 5

Adding 100.0g of epoxy itaconate resin, 0.004g of Kanster catalyst containing platinum and 30.0g of isopropanol into a four-mouth bottle provided with a thermometer, a stirrer and a condenser, heating and stirring uniformly, raising the temperature to 70 ℃, slowly dripping 9.0g of hydrogen-terminated polysiloxane, raising the temperature to 90 ℃ (the reflux temperature of the isopropanol), continuing to react for 8 hours, and carrying out reduced pressure distillation to recover the isopropanol to obtain the polysiloxane-modified epoxy itaconate.

And slowly dropwise adding 74.9g of acetone solution (solid content is 50 wt%) of the semi-blocked isocyanate intermediate into 109.0g of polysiloxane modified epoxy itaconate acetone solution (solid content is 66.7 wt%), stirring and heating to the acetone reflux temperature, and reacting for 6 hours to obtain the semi-blocked isocyanate polysiloxane modified epoxy itaconate resin. Adding 24.0g of triethanolamine for neutralization, and continuing the reflux reaction for 0.5 h. Slowly dripping distilled water, stirring and dispersing to obtain an aqueous dispersion with the solid content of 60 wt%, and carrying out reduced pressure distillation to recover acetone to obtain the polysiloxane modified epoxy itaconate resin aqueous dispersion. The water absorption and mechanical properties of the resin photo-curable lacquer film are shown in fig. 1 and table 1.

TABLE 1 polysiloxane modified half-blocked isocyanate epoxy itaconate resin film Properties

Table 1 shows the effect of the amount of polysiloxane on the mechanical properties of half-blocked isocyanate epoxy itaconate resin films. As can be seen from the table, with the increase of the amount of the polysiloxane, the flexibility and the pencil hardness are improved, mainly because more-Si-O-Si-flexible long chains and flexible groups are grafted in the molecules of the modified resin, the flexibility of the resin is increased, the flexibility of a paint film is improved, and simultaneously with the increase of the amount of the silicon, the average molecular weight of the resin is increased, the formed cross-linked network structure is more compact, and the hardness is slightly improved.