阅读说明：本技术 一种聚氨酯丙烯酸酯及其制备方法和应用 (Polyurethane acrylate and preparation method and application thereof ) 是由 尹敬锋 罗青宏 刘晓暄 于 2021-01-18 设计创作，主要内容包括：本发明公开了一种聚氨酯丙烯酸酯及其制备方法和应用,所述聚氨酯丙烯酸酯包括如下按重量份计算的组分：二异氰酸酯20～35份；磺酸盐聚酯二元醇35～75份；二元醇扩链剂2～5份；阻聚剂0.05～0.1份；含羟基的丙烯酸酯单体封端剂3～10份；所述磺酸盐聚酯二元醇与所述二元醇扩链剂的质量比为(12～25)：1。所述聚氨酯丙烯酸酯制备成漆膜后具有低气味、硬度和柔韧性好。(The invention discloses a polyurethane acrylate and a preparation method and application thereof, wherein the polyurethane acrylate comprises the following components in parts by weight: 20-35 parts of diisocyanate; 35-75 parts of sulfonate polyester dihydric alcohol; 2-5 parts of a glycol chain extender; 0.05-0.1 part of polymerization inhibitor; 3-10 parts of a hydroxyl-containing acrylate monomer end-capping agent; the mass ratio of the sulfonate polyester diol to the diol chain extender is (12-25): 1. the polyurethane acrylate prepared into a paint film has low odor and good hardness and flexibility.)

1. The polyurethane acrylate is characterized by comprising the following components in parts by weight:

the mass ratio of the sulfonate polyester diol to the diol chain extender is (12-25): 1.

2. the urethane acrylate according to claim 1, wherein the mass ratio of the sulfonate polyester diol to the diol chain extender is (15-20): 1.

3. the urethane acrylate according to claim 1, wherein the diisocyanate is one of isophorone diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate.

4. The urethane acrylate according to claim 1, wherein the weight average molecular weight of the sulfonate polyester diol is 1000 to 1200.

5. The urethane acrylate according to claim 1, wherein the glycol chain extender is one of 1, 4-butanediol and neopentyl glycol.

6. The urethane acrylate according to claim 1, wherein the polymerization inhibitor is one of p-hydroxyanisole and hydroquinone.

7. The urethane acrylate according to claim 1, wherein the hydroxyl group-containing acrylate monomer end-capping agent is one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, pentaerythritol triacrylate.

8. The method for preparing urethane acrylate according to any one of claims 1 to 7, comprising the steps of:

s1, uniformly mixing diisocyanate and sulfonate polyester diol, adding an organic tin catalyst, and reacting at 70-80 ℃ to obtain a polyurethane prepolymer I;

s2, adding a dihydric alcohol chain extender into the polyurethane prepolymer I in the step S1 at the temperature of 70-80 ℃, and carrying out mixing reaction to obtain a polyurethane prepolymer II;

and S3, adding a polymerization inhibitor and a hydroxyl-containing acrylate monomer end-capping reagent into the polyurethane prepolymer II obtained in the step S2 at 70-80 ℃, and carrying out mixing reaction to obtain the polyurethane acrylate.

9. Use of the urethane acrylates according to any one of claims 1 to 7 for the preparation of photocurable coatings.

Technical Field

The invention relates to the technical field of curing coatings, and particularly relates to polyurethane acrylate and a preparation method and application thereof.

Background

Polyurethane is widely used in the fields of adhesives, inks, coatings, textiles, biomaterials, etc. due to its unique structure, good processability, flexibility in adjusting soft/hard segments. With the increasing awareness of environmental protection and the stricter national regulations, the use of traditional solvent-based polyurethanes is more and more limited, and the waterborne polyurethanes are more concerned.

The waterborne polyurethane is safe, environment-friendly, non-toxic and non-combustible, but has the defects of water resistance, wear resistance, mechanical property and the like, the polyacrylate has good water resistance and weather resistance, the raw material cost is low, and the polyacrylate is easy to obtain, but when the polyacrylate is prepared into a paint film, the flexibility and hardness of the paint film are poor. The advantages of the polyurethane acrylate can be complemented to the maximum extent.

For example, chinese patent (CN111253547A) discloses a sulfonate ultraviolet-curable waterborne polyurethane and a preparation method thereof, which comprises the steps of firstly preparing a UV macromonomer from acrylic acid and diglycidyl ether as raw materials, and then reacting the UV macromonomer with diisocyanate, polyester diol, small-molecular polyol, and sulfonate hydrophilic monomer to obtain a target product, namely urethane acrylate, but the reaction process is complicated, the reaction time is long, and the photocuring rate of the urethane acrylate is slow.

Chinese patent (CN108503792A) discloses a water-based polyurethane acrylate resin and a preparation method thereof. The presence of mercapto monomers in the system results in a strong odour and the data show that the hardness and flexibility of the paint film are not good.

Disclosure of Invention

The invention provides the polyurethane acrylate for overcoming the defects of heavy smell, low hardness and poor flexibility of a paint film prepared from the waterborne polyurethane acrylate resin.

Another object of the present invention is to provide a method for preparing the urethane acrylate.

Another object of the invention is to provide the use of the urethane acrylates.

In order to achieve the purpose, the invention adopts the technical scheme that:

a polyurethane acrylate comprises the following components in parts by weight:

the mass ratio of the sulfonate polyester diol to the diol chain extender is (12-25): 1.

conventionally, in the process of synthesizing urethane acrylate, a carboxylic acid chain extender is generally added, an amine neutralizer is required to be added at the later stage for the substances, but the amine neutralizer has a relatively large odor. When the mass ratio of the sulfonate polyester diol to the diol chain extender is (12-25): 1, when the polyurethane acrylate is prepared into a paint film, the flexibility and hardness of the paint film are further increased, because the hard segment micro-phase region is fused into the soft segment micro-phase region, and the hard segment part plays a role in physical crosslinking in the soft segment part to limit the relative movement of molecular chains, so that the mechanical property of the paint film is improved.

Preferably, the mass ratio of the sulfonate polyester diol to the diol chain extender is (15-20): 1. when the mass ratio of the sulfonate polyester diol to the diol chain extender is (15-20): 1, the hardness and the flexibility of the paint film are improved.

Preferably, the diisocyanate is one of isophorone diisocyanate, toluene diisocyanate and hexamethylene diisocyanate.

Preferably, the weight average molecular weight of the sulfonate polyester diol is 1000-1200.

Preferably, the glycol chain extender is one of 1, 4-butanediol and neopentyl glycol.

Preferably, the polymerization inhibitor is one of p-hydroxyanisole and hydroquinone

Preferably, the hydroxyl-containing acrylate monomer end-capping agent is one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and pentaerythritol triacrylate.

The invention also provides a preparation method of the polyurethane acrylate, which comprises the following steps:

s1, uniformly mixing diisocyanate and sulfonate polyester diol, adding an organic tin catalyst, and reacting at 70-80 ℃ to obtain a polyurethane prepolymer I;

s2, adding a dihydric alcohol chain extender into the polyurethane prepolymer I in the step S1 at the temperature of 70-80 ℃, and carrying out mixing reaction to obtain a polyurethane prepolymer II;

and S3, adding a polymerization inhibitor and a hydroxyl-containing acrylate monomer end-capping reagent into the polyurethane prepolymer II obtained in the step S2 at 70-80 ℃, and carrying out mixing reaction to obtain the polyurethane acrylate.

And S4, adding deionized water into the polyurethane acrylate obtained in the step S3 for emulsification, and discharging to obtain the polyurethane acrylate emulsion with the solid content of 40%.

The polyurethane acrylate is applied to the preparation of photocureable coating.

Compared with the prior art, the invention has the beneficial effects that:

according to the polyurethane acrylate provided by the invention, a diol chain extender is adopted to replace a carboxylic acid chain extender in a system, so that the use of odor molecules is effectively avoided, and the addition of the diol chain extender can increase the flexibility of a final paint film.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, but the embodiments of the present invention are not limited thereto.

The reagents, methods and equipment adopted by the invention are conventional in the technical field if no special description is given.

The present invention will be described in detail with reference to examples and comparative examples.

The polyurethane acrylate is prepared by the following method in the examples and comparative examples, and the components are weighed according to the weight ratio shown in the table 1-3; the method comprises the following specific steps:

s1, uniformly mixing diisocyanate and sulfonate polyester diol, adding dibutyltin dilaurate, and reacting at 70-80 ℃ to obtain a polyurethane prepolymer I;

s2, adding a dihydric alcohol chain extender into the polyurethane prepolymer I in the step S1 at the temperature of 70-80 ℃, and carrying out mixing reaction to obtain a polyurethane prepolymer II;

and S3, adding a polymerization inhibitor and a hydroxyl-containing acrylate monomer end-capping agent into the polyurethane prepolymer II obtained in the step S2 at 70-80 ℃, and carrying out mixing reaction to obtain the polyurethane acrylate with the main chain containing sulfonate hydrophilic groups.

S4, adding deionized water into the polyurethane acrylate obtained in the step S3, emulsifying for 0.5h, and discharging to obtain the polyurethane acrylate emulsion with the solid content of 40%.

Examples 1 to 7

TABLE 1 formulations (parts) of examples 1 to 7

Examples 8 to 11 and comparative examples 1 to 3

TABLE 2 formulations (parts) of examples 8 to 11 and comparative examples 1 to 3

The above examples and comparative examples were each subjected to a performance test by the following method:

the polyurethane acrylate of the invention is applied to UV coatings. The specific components of the formula are calculated according to the mass parts as follows:

100 parts of urethane acrylate;

3 parts of photoinitiator

1. Tensile test

The test was carried out in GB/T1040.3-2006 using a CMT4204 electronic universal tester from Meits Industrial systems (China) Ltd. the test specimens were dumbbell-shaped, had dimensions of 50mm 4mm 0.5mm, a tensile rate of 50mm/min and the tensile strength and elongation at break were reflected in the flexibility of the paint film.

2. Pencil hardness the pencil hardness of the paint films was tested according to GB/T6739-.

TABLE 3 data for examples and comparative examples

From examples 1 to 12, the paint films prepared by the examples all show good mechanical properties. Examples 1-3 varying the amount of diisocyanate resulted in increased tensile strength and decreased elongation at break of the paint film. This is because the urethane and urea structures in the urethane acrylate structure increase with the amount of diisocyanate used, and the rigidity of the paint film increases. Examples 4 to 7 change the amount of the sulfonate diol, thereby increasing the content of soft segments in the polyurethane chain, destroying the regularity of the polyurethane chain degree, decreasing the mechanical strength of the paint film, and increasing the elongation at break, but the mass ratio of the sulfonate polyester diol to the diol chain extender is (12 to 25): 1 has better mechanical strength and elongation at break in the middle of the change, and when the mass ratio of the sulfonate polyester glycol to the glycol chain extender is (15-20): 1, the effect is better. Examples 10 to 11 vary the amount of blocking agent, which mainly affects the double bond content of the urethane acrylate. With the increase of the using amount of the end capping agent, the double bond content is increased, the crosslinking degree in the paint film is increased, and the mechanical strength of the paint film is improved.

The above examples 1 to 11 do not contain odorous molecules, so the odor of the finished paint film is very low.

From comparative examples 1-3, the glycol chain extender is not added in comparative example 1, which can cause the adhesive film to have poor mechanical properties and to be soft and brittle; the mass ratio of the sulfonate polyester diol to the diol chain extender in comparative examples 2 and 3 is (15-20): 1 is not in the range, and the flexibility and the mechanical property of the adhesive film are poor, so that the application of the adhesive film is limited.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.