CN103254397A - Waterproof and weather-resistant polyester-type waterborne polyurethane emulsion and preparation method - Google Patents

Abstract

The invention relates to a water-resistant and weather-resistant polyester-type water-based polyurethane emulsion and a preparation method thereof. It is prepared by reacting the following raw materials according to the mass percentage: 8.00%-19.00% of polyester diol, 3.00%-10.00% of diisocyanate, and 0.02% of catalyst %～0.04%, chain extender 0.70%～1.70%, organic solvent 5.00%～10.00%, organic silicon 2.00%～12.00%, neutralizing agent 0.60%～1.20%, end-blocking agent 0.50%～1.60%, deionization Water 57.00% ~ 65.00%. Preparation method: add diisocyanate, catalyst and chain extender to dehydrated polyester diol for reaction, add organic solvent and amino silicone oil to obtain silicone-modified grafted polyurethane; add end-blocking agent, neutralizing agent and water Response, that is. The material of the invention is stable in storage, and the coating film has ideal hardness, adhesion, water resistance and weather resistance.

Description

A kind of water-resistant, weather-resistant polyester type aqueous polyurethane emulsion and preparation method thereof

technical field

The invention belongs to the field of preparation of water-resistant and weather-resistant polyester materials, in particular to a preparation method of water-resistant and weather-resistant polyester water-based polyurethane emulsion.

Background technique

Water-based polyurethane uses water as the dispersion medium, and has the advantages of non-combustibility, low odor and no pollution to the environment. In recent years, as people pay more and more attention to environmental protection, waterborne polyurethane has been widely used in various industries. Most waterborne polyurethanes are prepared by the self-emulsification method. Due to the presence of hydrophilic groups in the polyurethane structure prepared by this method, the water resistance, solvent resistance and weather resistance of the coating film are poor, which limits its application range. Although the hardness and adhesion of polyester-based water-based polyurethane coatings are superior to those of polyether-based water-based polyurethanes, the ester groups of polyester polyols are easily hydrolyzed, and the water resistance of polyester-based water-based polyurethanes is worse than that of polyether-based water-based polyurethanes. The water-based polyurethane produced by domestic enterprises is mainly polyether-based water-based polyurethane. Therefore, it is of practical significance to improve the water resistance of polyester waterborne polyurethane.

At present, workers in the domestic polyurethane field have done some research work on polyester-based waterborne polyurethane and given reports. For example, the publication number is: CN1390907A, and the invention name is a method for preparing a hydrolysis-resistant polyester polyurethane adhesive. The ester group is protected by increasing the molecular weight of the straight-chain polyester diol and introducing a diol with side groups. Thereby improving the water resistance of water-based polyester polyurethane adhesive; as the publication number is: CN102516466A, the title of invention is a water-resistant, weather-resistant polyester polyurethane-polyacrylate aqueous dispersion and its preparation method, using acrylic acid monomer and The polyester polyurethane prepolymer is copolymerized, and acrylic acid is introduced into the polyurethane to improve the water resistance of the polyester waterborne polyurethane. However, there are no research reports and application examples on modifying polyester-type water-based polyurethane with macromolecular silicone to improve the water resistance and weather resistance of polyurethane.

Contents of the invention

The technical problem to be solved by the present invention is to provide a water-resistant, weather-resistant polyester-based water-based polyurethane emulsion and a preparation method thereof. The polyester-based water-based polyurethane coating film of the invention has ideal hardness and adhesion, and can be used as Coating agent for ceramics and plastics; the polyester-based water-based polyurethane of the invention is modified and grafted with side chains through organosilicon, and the highest mass ratio of organosilicon content can reach 30% of the modified polyurethane. On the basis of excellent adhesion and coating film hardness, the modified polyurethane coating film is endowed with excellent water resistance and weather resistance.

A water-resistant and weather-resistant polyester-based water-based polyurethane emulsion of the present invention is formed by reacting the following raw materials according to mass percentage: polyester diol 8.00%-19.00%, diisocyanate 3.00%-10.00%, catalyst 0.02%-0.04% , chain extender 0.70%~1.70%, organic solvent 5.00%~10.00%, silicone (amino silicone oil or ternary block silicone oil) 2.00%~12.00%, neutralizer 0.60%~1.20%, end-capping agent 0.50% ～1.60%, deionized water 57.00%～65.00%, the total content of the above components is 100%.

The polyester diol is one of adipic acid polyester diol, polycarbonate diol and polycaprolactone diol.

The diisocyanate is one of toluene diisocyanate TDI, 4,4-diphenylmethane diisocyanate MDI, isophorone diisocyanate IPDI, 1,6-hexamethylene diisocyanate HDI, dicyclohexylmethane diisocyanate HMDI species; the catalyst is one of dibutyltin dilaurate and stannous octoate.

The chain extender is an anionic chain extender or a nonionic chain extender.

The anionic chain extender is dimethylolpropionic acid, and the nonionic chain extender is one of 1,4-butanediol and ethylene glycol.

The organic solvent is one of acetone, N-methylpyrrolidone, and isopropanol; the organic silicon is amino silicone oil or ternary block silicone oil.

The amino silicone oil is one of amino group-containing and imino group-containing polysiloxanes.

The capping agent is ethanol, and the neutralizing agent is triethylamine.

A kind of water resistance of the present invention, the preparation method of weather-resistant polyester type aqueous polyurethane emulsion comprises:

(1) Raise the temperature of polyester diol to 100-120°C, vacuum dehydration treatment for 15-30min, and cool down to 30-50°C to obtain dehydrated polyester diol;

(2) Add diisocyanate and catalyst to the dehydrated polyester diol, stir evenly, heat up to 78°C-80°C, keep warm for 60min-90min to obtain the initial polymer;

(3) Control the temperature of the above-mentioned initial polymer at 78°C-80°C, add a chain extender, and react for 60-90min to obtain a polyurethane prepolymer;

(4) Add the organic solvent into the polyurethane prepolymer, stir evenly, cool down to 0°C-5°C in an ice bath, then drop in silicone, and react for 60-90min to obtain organically modified polyurethane;

(5) Add the end-capping agent to the silicone-modified polyurethane, react for 30 minutes at room temperature, then add neutralizer, stir for 15-20 minutes at room temperature, add deionized water, stir, emulsify and disperse for 15-30 minutes, that is Obtain water-resistant and weather-resistant polyester water-based polyurethane emulsion.

The step (1) is carried out in a reaction vessel connected with a stirring device.

The object of the present invention is to provide a water-resistant, weather-resistant polyester water-based polyurethane emulsion, using polyester diol as soft segment material, anionic monomer as hydrophilic chain extender and diisocyanate reaction to prepare polyurethane prepolymer, and Polyurethane prepolymer is modified by side chain grafting with macromolecular silicone (amino silicone oil or ternary block silicone oil), and the prepared silicone-modified polyester water-based polyurethane is in the state of microemulsion and has good storage stability. During the coating process, the polyurethane unit and siloxane segment in the modified polyurethane produce microphase separation, the polyurethane unit is combined with the substrate of the coating film, and the siloxane is enriched on the surface of the coating film, which can endow the modified polyurethane with excellent adhesion. At the same time of adhesion, the water resistance and weather resistance of the coating film are obviously improved.

The product of the present invention has the excellent characteristics of polyester polyurethane and silicon materials and can be used as a spraying agent for wood, metal, ceramics and plastics. The coating film has a hardness of 4-5H (pencil hardness), an adhesion force of 4-5B, and can be soaked in water. The 24h water absorption rate is lower than 15%, and the coating film has ideal weather resistance.

Beneficial effect

(1) The polyester-based water-based polyurethane coating film of the present invention has ideal hardness and adhesion, and can be used as a coating agent for wood, metal, ceramics and plastics;

(2) The polyester-type water-based polyurethane of the present invention is grafted with side chain modification by organosilicon, and the highest mass ratio of organosilicon content can reach 30% of the modified polyurethane, which ensures the excellent adhesion of polyester-type polyurethane On the basis of hardness and coating film hardness, the modified polyurethane coating film is endowed with excellent water resistance and weather resistance.

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

According to the mass percentage, it is formed by the reaction of the following raw materials: polyester diol (polyhexamethylene adipate diol, molecular weight 1000) 15.55%, isophorone diisocyanate 8.84%, dibutyltin dilaurate 0.02%, 1,4-butanediol 0.41%, dimethylol propionic acid 1.01%, acetone 10.00%, amino silicone oil 2.86%, ethanol 1.46%, triethylamine 0.99%, deionized water 58.86%, the total content of the above components is 100%;

Add the weighed polyester diol into a reaction vessel connected with a stirring device, raise the temperature of the polyester diol in the reaction vessel to 100°C for vacuum dehydration treatment, the treatment time is 30min, and the vacuum dehydration treatment is completed Finally, the polyester diol is cooled to 30°C to obtain the dehydrated polyester diol; then the weighed isophorone diisocyanate IPDI and dibutyltin dilaurate are added to the dehydrated polyester diol In the process, after stirring evenly, raise the temperature to 78°C-80°C, and keep the temperature for 90 minutes to obtain the initial polymer; keep the temperature of the initial polymer at 78°C-80°C and add the weighed 1,4-butanediol and dimethylol Propionic acid, heat preservation reaction 90min, that is made of polyurethane prepolymer;

Add acetone to the polyurethane prepolymer and stir evenly, and cool the polyurethane prepolymer to 0°C-5°C with an ice bath; then add amino silicone oil to the polyurethane prepolymer dropwise within 25 minutes, and react at 0°C-5°C for 60 minutes , that is, the amino silicone oil modified grafted polyurethane is obtained, and the ice bath is withdrawn;

Warm up the prepared amino silicone oil-modified polyurethane to room temperature, add weighed triethylamine, stir rapidly, neutralize for 15 minutes, then add weighed ethanol, capping reaction for 30 minutes, finally add deionized water, high-speed stirring emulsification dispersion After 15 minutes, the water-resistant and weather-resistant polyester water-based polyurethane emulsion of the present invention is prepared.

Example 2

According to the mass percentage, it is formed by the reaction of the following raw materials: polyester diol (polyethylene adipate-1,4-butylene glycol ester diol, molecular weight 1000) 9.33%, dibutyltin dilaurate 0.04%, iso Phorne diisocyanate 7.23%, dimethylolpropionic acid 1.06%, ethylene glycol 0.50%, isopropanol 7.30%, amino silicone oil 9.00%, ethanol 1.20%, triethylamine 1.03%, deionized water 63.31%, The total content of the above components is 100%;

Add the weighed polyester diol into a reaction vessel connected with a stirring device, raise the temperature of the polyester diol in the reaction vessel to 110°C for vacuum dehydration treatment, the treatment time is 30min, and the vacuum dehydration treatment is completed Finally, lower the temperature of the polyester diol to 40°C to obtain the dehydrated polyester diol; then add the weighed isophorone diisocyanate and dibutyltin dilaurate into the dehydrated polyester diol , after stirring evenly, raise the temperature to 78°C-80°C, keep warm for 60 minutes to obtain the initial polymer; keep the temperature of the initial polymer at 78°C-80°C, add the weighed ethylene glycol and dimethylol propionic acid, keep warm React for 90 minutes to make polyurethane prepolymer;

Add isopropanol to the polyurethane prepolymer and stir evenly, and cool the polyurethane prepolymer to 0°C-5°C with an ice bath; then add amino silicone oil to the polyurethane prepolymer dropwise within 35 minutes, and cool it at 0°C-5°C After reacting for 90 minutes, the amino silicone oil modified grafted polyurethane was obtained, and the ice bath was withdrawn;

Warm up the prepared amino silicone oil-modified polyurethane to room temperature, add weighed triethylamine, stir quickly, neutralize for 10 minutes, then add weighed ethanol, capping reaction for 30 minutes, then add deionized water, high-speed stirring emulsification After dispersing for 20 minutes, the water-resistant and weather-resistant polyester water-based polyurethane emulsion of the present invention is prepared.

Example 3

It is formed by reacting the following raw materials according to mass percentage: polyester diol (polycaprolactone diol, molecular weight 2000) 18.46%, stannous octoate 0.03%, 4,4-diphenylmethane diisocyanate 6.97%, 1, 0.19% 4-butanediol, 0.70% dimethylol propionic acid, 5.50% N-methylpyrrolidone, 3.58% ternary block silicone oil, 1.48% ethanol, 0.66% triethylamine, 62.43% deionized water, above The sum of the contents of the components is 100%;

Add the weighed polyester diol into a reaction vessel connected with a stirring device, raise the temperature of the polyester diol in the reaction vessel to 120°C for vacuum dehydration treatment, the treatment time is 20min, and the vacuum dehydration treatment is completed Finally, the temperature of the polyester diol was lowered to 40°C to obtain the dehydrated polyester diol; then, the weighed 4,4-diphenylmethane diisocyanate and stannous octoate were added to the dehydrated polyester diol. In alcohol, after stirring evenly, raise the temperature to 78°C-80°C, and keep it warm for 90 minutes to obtain the initial polymer; control the temperature of the initial polymer at 78°C-80°C and add the weighed 1,4-butanediol and dihydroxy Methylpropionic acid, heat preservation reaction for 90min, which is made into polyurethane prepolymer;

Add N-methylpyrrolidone to the polyurethane prepolymer and stir evenly, and use an ice bath to cool the polyurethane prepolymer to 0°C-5°C; then add the tertiary block silicone oil to the polyurethane prepolymer dropwise within 30 minutes, and then React at 0°C-5°C for 60 minutes to obtain three-block silicone oil-modified grafted polyurethane, and remove from the ice bath;

Warm up the prepared ternary block silicone oil-modified polyurethane to room temperature, add weighed triethylamine, stir rapidly, neutralize for 15 minutes, then add ethanol, capping reaction for 30 minutes, finally add deionized water, stir at high speed After emulsifying and dispersing for 30 minutes, the water-resistant and weather-resistant polyester water-based polyurethane of the present invention is prepared.

Example 4

The water-resistant polyester water-based polyurethane of the present invention is formed by reacting the following raw materials according to mass percentage: polyester diol (polyhexamethylene adipate diol, molecular weight 2000) 14.63%, dibutyltin dilaurate 0.02% , toluene diisocyanate 3.12%, dimethylol propionic acid 0.71%, N-methylpyrrolidone 7.65%, ternary block silicone oil 11.34%, triethylamine 0.64%, ethanol 0.62%, deionized water 61.27%, the above groups The total content of the points is 100%;

Add the weighed polyester diol into a reaction vessel connected with a stirring device, raise the temperature of the polyester diol in the reaction vessel to 100°C for vacuum dehydration treatment, the treatment time is 30min, and the vacuum dehydration treatment is completed Finally, lower the temperature of the polyester diol to 50°C to obtain the dehydrated polyester diol; then add the weighed toluene diisocyanate and dibutyltin dilaurate into the dehydrated polyester diol, and stir evenly After heating up to 78°C-80°C, heat preservation reaction for 90 minutes, the initial polymer is obtained; control the temperature of the initial polymer at 78°C-80°C, add dimethylol propionic acid, and heat preservation reaction for 60 minutes, that is, the product Polyurethane prepolymer;

Add N-methylpyrrolidone into the polyurethane prepolymer and stir evenly, and cool the polyurethane prepolymer to 0°C-5°C with an ice bath; then add the tertiary block silicone oil to the polyurethane prepolymer dropwise within 35 minutes, keep warm After reacting for 90 minutes, the tertiary block silicone oil-modified grafted polyurethane was obtained, and the ice bath was withdrawn;

Warm up the prepared ternary block silicone oil-modified polyurethane to room temperature, add weighed triethylamine, stir rapidly, neutralize for 10 minutes, then add ethanol, capping reaction for 30 minutes, finally add deionized water, stir at high speed After emulsifying and dispersing for 20 minutes, the water-resistant and weather-resistant polyester water-based polyurethane emulsion of the present invention is prepared.

Example 5

The water-resistant polyester water-based polyurethane emulsion of the present invention is formed by reacting the following raw materials according to mass percentage: polycarbonate diol (molecular weight 2000) 16.38%, dibutyltin dilaurate 0.04%, 1,6-hexamethylene diisocyanate 4.53% %, 1,4-butanediol 0.20%, dimethylol propionic acid 1.50%, N-methylpyrrolidone 9.50%, amino silicone oil 5.55%, triethylamine 0.95%, ethanol 0.93%, deionized water 60.42%, The total content of the above components is 100%;

Add the weighed polyester diol into a reaction vessel connected with a stirring device, raise the temperature of the polyester diol in the reaction vessel to 110°C for vacuum dehydration treatment, the treatment time is 30min, and the vacuum dehydration treatment is completed Finally, lower the temperature of the polyester diol to 40°C to obtain the dehydrated polyester diol; then add the weighed 1,6-hexamethylene diisocyanate and dibutyltin dilaurate into the dehydrated polyester diol In the process, after stirring evenly, raise the temperature to 78°C-80°C, and keep it warm for 90 minutes to obtain the initial polymer; control the temperature of the initial polymer at 78°C-80°C and add the weighed 1,4-butanediol and dimethylol Propionic acid, heat preservation reaction 60min, that is made of polyurethane prepolymer;

Add N-methylpyrrolidone to the polyurethane prepolymer and stir evenly, and use an ice bath to cool the polyurethane prepolymer to 0°C-5°C; then add amino silicone oil to the polyurethane prepolymer dropwise within 30 minutes, and keep it warm for 80 minutes. Promptly obtain amino silicone oil modified graft polyurethane;

Warm up the prepared amino silicone oil-modified polyurethane to room temperature, add weighed triethylamine, stir rapidly, neutralize for 15 minutes, then add weighed ethanol, capping reaction for 30 minutes, finally add deionized water, stir at high speed After emulsifying and dispersing for 30 minutes, the water-resistant polyester water-based polyurethane emulsion of the present invention is prepared.

Claims (9)

1. water-fast, weatherable polyether type aqueous polyurethane emulsion, it is characterized in that: formed by following raw material reaction by mass percentage: polyester diol 8.00%～19.00%, vulcabond 3.00%～10.00%, catalyzer 0.02%～0.04%, chainextender 0.70%～1.70%, organic solvent 5.00%～10.00%, organosilicon 2.00%～12.00%, neutralizing agent 0.60%～1.20%, end-capping reagent 0.50%～1.60%, deionized water 57.00%～65.00%, above components contents summation is 100%.

2. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 1 is characterized in that: described polyester diol is a kind of in adipate polyester dibasic alcohol, PCDL, the polycaprolactone dibasic alcohol.

3. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 1, it is characterized in that: described vulcabond is tolylene diisocyanate TDI, 4, a kind of among 4 ‵-diphenylmethanediisocyanate MDI, isophorone diisocyanate IPDI, hexamethylene diisocyanate HDI, the dicyclohexyl methane diisocyanate HMDI; Catalyzer is a kind of in dibutyl tin laurate, the stannous octoate.

4. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 1, it is characterized in that: described chainextender is negatively charged ion chainextender or nonionic chainextender.

5. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 4, it is characterized in that: described negatively charged ion chainextender is dimethylol propionic acid, the nonionic chainextender is a kind of in 1,4-butyleneglycol, the ethylene glycol.

6. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 1 is characterized in that: described organic solvent is a kind of in acetone, N methyl-2-pyrrolidone, the Virahol; Organosilicon is amido silicon oil or ternary block silicone oil.

7. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 6 is characterized in that: described amido silicon oil is to contain a kind of in the polysiloxane of amino, imido-.

8. a kind of water-fast, weatherable polyether type aqueous polyurethane emulsion according to claim 1, it is characterized in that: described end-capping reagent is ethanol, neutralizing agent is triethylamine.

9. the preparation method of water-fast, a weatherable polyether type aqueous polyurethane emulsion as claimed in claim 1 comprises:

(1) polyester diol is warming up to 100-120 ℃, 15-30min is handled in vacuum hydro-extraction, is cooled to 30-50 ℃, the polyester diol after obtaining dewatering;

(2) with in the polyester diol after vulcabond and the catalyzer adding dehydration, stir, be warming up to 78 ℃～80 ℃, insulation reaction 60min-90min obtains aggressiveness just;

(3) temperature of above-mentioned aggressiveness is just controlled at 78 ℃-80 ℃, added chainextender, reaction 60-90min obtains base polyurethane prepolymer for use as;

(4) organic solvent is added in the base polyurethane prepolymer for use as, stir, ice bath is cooled to 0 ℃-5 ℃, splashes into organosilicon then, and reaction 60-90min obtains organically-modified urethane;

(5) end-capping reagent is added in the organic silicon modified polyurethane, react 30min under the room temperature condition, add neutralizing agent then, under the room temperature condition, stir process 15-20min adds deionized water, stirring and emulsifying is disperseed 15-30min, namely gets water-fast, weatherable polyether type aqueous polyurethane emulsion.