CN106700021A - Chitosan modified cationic waterborne polyurethane resin and preparation method and application thereof - Google Patents

Abstract

The invention provides a kind of chitosan modified cationic waterborne polyurethane resin, as shown in formula (I), R ₁ is selected from a kind of in formula (1) ~ formula (5); R ₂ is as shown in formula (6) Show. Compared with the prior art, the present invention uses chitosan molecules to replace the use of some polyols or chain extenders to reduce the dependence on petrochemical resources. At the same time, the introduction of chitosan segments makes chitosan modified cationic waterborne polyurethane The resin has a good hydrophobic effect, which improves the water resistance and mechanical properties of its film formation.

Description

Chitosan modified cationic waterborne polyurethane resin, its preparation method and application

technical field

The invention belongs to the technical field of polyurethane, and in particular relates to a chitosan-modified cationic waterborne polyurethane resin, a preparation method and application thereof.

Background technique

Compared with solvent-based polyurethane, water-based polyurethane has the advantages of low toxicity, non-combustibility, low pollution, energy saving, and safety. Therefore, the research and production of water-based polyurethane has been valued by countries all over the world.

The main raw materials of low-molecular-weight diols currently used in the preparation of polyurethane are based on petroleum resources, and the prepared water-based polyurethane emulsion cannot get rid of the dependence on petrochemical resources. Copolymerization of carbon dioxide and propylene oxide to prepare carbon dioxide-based polyols, and then prepare water-based polyurethanes can reduce the dependence on petrochemical resources. In addition, water-based polyurethanes prepared by carbon dioxide-based polyols and traditional polyester polyols and polyether polyols are used to prepare water-based polyurethanes. It has relatively excellent water resistance and mechanical properties, and is an ideal raw material for preparing water-based polyurethane emulsion. However, due to the introduction of hydrophilic groups into the synthetic raw materials of waterborne polyurethane, pure waterborne polyurethane has disadvantages such as poor mechanical properties, poor water resistance, and poor weather resistance after film formation. The modification of water-based polyurethane has become a research hotspot at present. In view of the requirements of "green chemistry" and "clean production", it is necessary to use natural materials for modification to obtain a truly environmentally friendly water-based polyurethane adhesive with excellent comprehensive performance. .

Chitin is a polysaccharide natural polymer, which widely exists in arthropods, mollusks, protozoa, coelenterates, seaweeds, and fungi, and its production in nature is second only to cellulose. Generally speaking, chitosan can be called chitosan when more than 55% of the N-acetyl group of chitin is removed. Chitosan is the most valuable natural renewable resource. In recent years, with the reduction of petroleum and coal reserves and the increasingly serious environmental pollution, the application of chitosan, a natural renewable resource, has been paid attention to. As we all know, chitosan has good biocompatibility, low toxicity, antibacterial, biodegradability and various biological activities, etc. It can not only be used to prepare food packaging materials, paper additives, water treatment ion exchange resins, etc. It can be used in medical materials, drug slow-release carriers, antibacterial fibers, etc. In addition, there are a large number of highly reactive hydroxyl and amino groups on the molecular chain of chitosan, which creates good conditions for chemical modification.

The present invention considers to provide a chitosan-modified cationic waterborne polyurethane resin.

Contents of the invention

In view of this, the technical problem to be solved in the present invention is to provide a kind of chitosan modified cationic waterborne polyurethane resin, its preparation method and application, and this chitosan modified cationic waterborne polyurethane resin has good water resistance and mechanical properties .

The invention provides a kind of chitosan modified cationic waterborne polyurethane resin, as shown in formula (I):

-R ₁ -one selected from the following structures:

-R ₂ -as shown in formula (6):

m is 1-30, z is 1-35;

R ₃ is selected from one or more of the following structures:

Cl formula (10);

-R ₄ is selected from one of the following structures:

-CH ₃ formula (11);

a is an integer from 1 to 4;

n is an integer of 2-200.

The present invention also provides a kind of preparation method of chitosan modified cationic waterborne polyurethane resin, comprising the following steps:

S1) In a protective atmosphere, mix the carbon dioxide-based diol containing the structure of formula (6) with the diisocyanate represented by formula (II), and heat the reaction to obtain the first product;

S2) reacting the first product with the hydrophilic chain extender represented by formula (III) in the presence of a catalyst to obtain a second product;

S3) mixing and heating the second product, chitosan and diol represented by formula (IV), to obtain a third product;

S4) the third product is mixed with an acid for neutralization reaction, and after emulsification, the chitosan-modified cationic waterborne polyurethane resin shown in formula (I) is obtained;

OCN-R ₁ -NCO formula (II);

-R ₁ -one selected from the following structures:

-R ₂ -as shown in formula (6):

m is 1-30, z is 1-35;

R ₃ is selected from one or more of the following structures:

Cl formula (10);

-R ₄ is selected from one of the following structures:

-CH ₃ formula (11);

a is an integer from 1 to 4;

n is an integer of 2-200.

Preferably, the molecular weight of the carbon dioxide-based diol containing the structure of formula (6) is 1500-5000 Daltons.

Preferably, the temperature of the heating reaction in the step S1) is 70°C-80°C; the time of the heating reaction is 1.5-3h;

The reaction temperature in the step S2) is 30°C-40°C; the reaction time is 1-2h;

The temperature of the heating reaction in the step S3) is 65°C-85°C; the time of the heating reaction is 1.5-2h.

Preferably, the mass ratio of the carbon dioxide-based diol containing the structure of formula (6) to the diisocyanate represented by formula (II) is (110-185): (16-92);

The mass ratio of the hydrophilic chain extender represented by the formula (III) to the carbon dioxide-based diol containing the structure of the formula (6) is: (2.95-11.40): (110-185);

The mass ratio of the chitosan to the carbon dioxide-based diol containing the structure of formula (6) is (2.95-11.40): (110-185).

Preferably, the catalyst in the step S2) is dibutyltin dilaurate.

Preferably, the step S5) is specifically:

After the third product is mixed with acid for neutralization reaction, add water and stir for emulsification to obtain the chitosan-modified cationic waterborne polyurethane resin shown in formula (I); the speed of the stirring is 1200～1800rpm; the The stirring time is 0.5~2h.

The present invention also provides an application of the chitosan-modified cationic waterborne polyurethane resin in coatings.

Preferably, the coating includes:

-R ₁ -one selected from the following structures:

-R ₂ -as shown in formula (6):

m is 1-30, z is 1-35;

R ₃ is selected from one or more of the following structures:

Cl formula (10);

-R ₄ is selected from one of the following structures:

-CH ₃ formula (11);

a is an integer from 1 to 4;

n is an integer of 2-200.

The invention provides a kind of chitosan modified cationic waterborne polyurethane resin, as shown in formula (I), R ₁ is selected from a kind of in formula (1) ~ formula (5); R ₂ is as shown in formula (6) m is 1-30, z is 1-35; _R3 is an acid group; R4 is selected from C1 _- C10 alkyl or C6-C10 aromatic group; a is an integer of 1-4; n is 2-200 an integer of . Compared with the prior art, the present invention uses chitosan molecules to replace the use of some polyols or chain extenders to reduce the dependence on petrochemical resources. At the same time, the introduction of chitosan segments makes chitosan modified cationic waterborne polyurethane The resin has a good hydrophobic effect, which improves the film-forming water resistance and mechanical properties of the chitosan-modified cationic waterborne polyurethane resin.

Description of drawings

Fig. 1 obtains the infrared spectrogram of the chitosan modified cationic waterborne polyurethane resin shown in formula (I) in the embodiment of the present invention 1;

Fig. 2 is the infrared spectrogram that obtains the chitosan modified cationic waterborne polyurethane resin shown in formula (I) in the embodiment 2 of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a kind of chitosan modified cationic waterborne polyurethane resin, as shown in formula (I):

The -R ₁ - is one of the following structures:

-R ₂ -as shown in formula (6):

m is 1-30, preferably 10-25; z is 1-35, preferably 5-30;

_R3 is an acid group, preferably one of the following structures:

Cl Formula (10).

R4 is C1 _- C10 alkyl or C6-C10 aryl, preferably C1-C8 alkyl or C6-C8 aryl, more preferably C1-C6 alkyl or phenyl, and more preferably C1 ~C4 alkyl or phenyl, most preferably one of the following structures:

-CH ₃ formula (11);

a is an integer of 1 to 4, preferably an integer of 2 to 3;

n is an integer of 2-200.

Wherein formula (I) in represents a repeating unit.

In the present invention, chitosan molecules are used to replace part of polyols or chain extenders to reduce dependence on petrochemical resources. At the same time, the introduction of chitosan segments makes chitosan-modified cationic waterborne polyurethane resins have better hydrophobic effect , improve the weather resistance, water resistance and mechanical properties of chitosan modified cationic waterborne polyurethane resin film.

The present invention also provides a kind of preparation method of above-mentioned chitosan modified cationic waterborne polyurethane resin, it is characterized in that, comprises the following steps:

S1) In a protective atmosphere, mix the carbon dioxide-based diol containing the structure of formula (6) with the diisocyanate represented by formula (II), and heat the reaction to obtain the first product;

S2) reacting the first product with the hydrophilic chain extender represented by formula (III) in the presence of a catalyst to obtain a second product;

S3) mixing and heating the second product, chitosan and diol represented by formula (IV), to obtain a third product;

S4) the third product is mixed with an acid for neutralization reaction, and after emulsification, the chitosan-modified cationic waterborne polyurethane resin shown in formula (I) is obtained;

OCN-R ₁ -NCO formula (II);

-R ₁ -one selected from the following structures:

-R ₂ -as shown in formula (6):

m is 1-30, z is 1-35;

R ₃ is an acid radical;

_R4 is selected from C1～C10 alkyl groups or C6～C10 aryl groups;

a is an integer from 1 to 4;

n is an integer of 2-200.

Wherein, the present invention does not have special limitation to the source of all raw materials, it is commercially available; The chitosan modified cationic water-based polyurethane resin shown in the formula (I) is the same as described above, and will not be repeated here.

In a protective atmosphere, the carbon dioxide-based dihydric alcohol comprising the structure of formula (6) is mixed with the diisocyanate shown in formula (II); the protective atmosphere is a protective atmosphere well known to those skilled in the art, and there is no special Restrictions, nitrogen is preferred in the present invention; the carbon dioxide-based dihydric alcohol comprising the structure of formula (6) can be a carbon dioxide-based dihydric alcohol well known to those skilled in the art, and there is no special limitation. The present invention is preferably according to the application number It is prepared for the Chinese patent of 201210086834.X or the Chinese patent application number of 201110231493.6; in the present invention, the molecular weight of the carbon dioxide-based diol containing the structure of formula (6) is preferably 1500-5000 Daltons; the The diisocyanate represented by formula (II) can be the diisocyanate well-known to those skilled in the art, and there is no special limitation. In the present invention, it is preferably toluene diisocyanate, diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate , one of isophorone diisocyanate and dicyclohexylmethane diisocyanate, more preferably toluene diisocyanate, diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate, and 4,4'-dicyclohexyl One of methane diisocyanate; the mass ratio of the carbon dioxide-based diol containing the structure of formula (6) to the diisocyanate represented by formula (II) is preferably (110-185): (16-92).

According to the present invention, the carbon dioxide-based dihydric alcohol represented by the formula (6) is preferably first dehydrated, and then mixed with the diisocyanate represented by the formula (II); the method for dewatering is well known to those skilled in the art There are no special limitations, the present invention preferably in a protective atmosphere, the carbon dioxide-based dihydric alcohol is heated to 90 ℃ ~ 110 ℃, vacuum distillation 1 ~ 1.5h to remove water; said comprising formula (6 ) structure carbon dioxide-based dihydric alcohol and the diisocyanate shown in formula (II) are preferably mixed in an organic solvent, and the organic solvent is an organic solvent well known to those skilled in the art, and there is no special limitation. In the present invention Preferably it is one or more of acetone, butanone and cyclohexanone, more preferably acetone or butanone, and more preferably butanone.

After mixing, the reaction is heated to obtain the first product; the temperature of the heating reaction is preferably 70° C. to 80° C.; the time of the heating reaction is 1.5 to 3 hours.

The first product is reacted with the hydrophilic chain extender represented by the formula (III) in the presence of a catalyst to obtain the second product; the hydrophilic chain extender represented by the formula (III) is preferably N- Methyldiethanolamine, N-butyldiethanolamine or N-phenyldiethanolamine; the mass ratio of the hydrophilic chain extender shown in the formula (III) to the carbon dioxide-based glycol comprising the structure of the formula (6) is preferred It is (2.95～11.40): (110～185); the hydrophilic chain extender represented by the formula (III) is preferably mixed in an organic solvent and added dropwise to the first product, more preferably using a dropping funnel to add dropwise In the first product; in the present invention, it is preferred to control the addition of the hydrophilic chain extender shown in formula (III) within 1h; the organic solvent is an organic solvent well known to those skilled in the art, and there is no Special restrictions, preferably one or more in acetone, methyl ethyl ketone and cyclohexanone in the present invention; Described catalyst is the catalyzer well known to those skilled in the art, without special restriction, preferably in the present invention Dibutyltin dilaurate; The mass ratio of the catalyst to the carbon dioxide-based glycol comprising the structure of formula (6) is preferably (0.001～0.0025): (110～185); the temperature of the reaction is preferably 30°C～40 ° C; the reaction time is 1 to 2 hours.

The second product, chitosan and the diol shown in formula (IV) are mixed and heated to react to obtain the third product; the chitosan is chitosan well known to those skilled in the art, and there is no special Limitation, it can be low viscosity chitosan (＜200mPa.s), medium viscosity chitosan (200～400mPa.s), also can be high viscosity chitosan (＞400mPa.s), in the present invention It is preferably low-viscosity chitosan; the mass ratio of said chitosan to the carbon dioxide-based glycol comprising the structure of formula (6) is preferably (2.95～11.40): (110～185); said formula (IV) The diol shown is the diol well-known to those skilled in the art, and there is no special limitation, butanediol is preferred in the present invention; The mass ratio is preferably (2.88-8.01): (110-185); the temperature of the heating reaction is preferably 65°C-85°C; the time of the heating reaction is preferably 1.5-2h.

The third product is neutralized with an acid, preferably until the pH value is 6-7; the acid is an acid well-known to those skilled in the art, and there is no special limitation. In the present invention, it is preferably trifluoroacetic acid , trichloroacetic acid, acetic acid or hydrochloric acid.

After neutralization, emulsification; the emulsification is preferably carried out according to the following steps: add water and stir for emulsification; the stirring speed is preferably 1200-1800 rpm; the stirring time is preferably 0.5-2h.

After emulsification, remove solvent, obtain the chitosan modified cationic aqueous polyurethane resin shown in formula (I); The method for described solvent removal is the method well-known to those skilled in the art and gets final product, without special limitation, among the present invention The solvent is preferably removed by distillation under reduced pressure.

The present invention uses carbon dioxide-based diols as raw materials to prepare cationic water-based polyurethane resins. This type of diols uses carbon dioxide as an important component in the preparation process, which not only reduces carbon emissions, but also reduces the dependence of polyurethane on petrochemical resources. In addition, as a natural renewable resource, chitosan is inexhaustible and inexhaustible. Modification with chitosan can meet the needs of "green chemistry" and "clean production". Chitosan molecules can replace some polyols or chain extenders to reduce dependence on petrochemical resources, and introducing chitosan segments into polyurethane molecular segments can make the coating film have better hydrophobic effect.

The present invention also provides an application of the chitosan-modified cationic waterborne polyurethane resin shown in the above formula (I) in coatings.

The coating preferably includes:

-R ₁ -one selected from the following structures:

-R ₂ -as shown in formula (6):

m is 1-30, z is 1-35;

R ₃ is an acid radical;

_R4 is selected from C1～C10 alkyl groups or C6～C10 aryl groups;

a is an integer from 1 to 4;

n is an integer of 2-200.

Wherein, the chitosan modified cationic water-based polyurethane resin shown in the formula (I) is the same as described above, and will not be repeated here.

According to the present invention, the water-based thickener, water-based leveling agent, water-based defoamer, water-based cosolvent, water-based wetting agent and water-based curing agent are commonly used in the art, and there is no special limitation; the water-based thickener It is preferably BENAQUA4000, one or more of WT-113 and WT115; the water-based leveling agent is preferably produced by BYK Company and is BYK-350, BYK-356, BYK-359, BYK-361N and BYK-381 One or more of them; the water-based defoamer is preferably one or more of BYK-019, BYK-021, BYK-028, BYK-A500, BYK-A501 and BYK-A550 produced by BYK. The water-based co-solvent is preferably one or more of isopropanol, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol butyl ether and dipropylene glycol butyl ether; the water-based lubricant The wetting agent is preferably one or more of BYK-187, BYK-3400 and BYK-3410 produced by BYK; the water-based curing agent is preferably 3100, XP2487/1, XP 2547 with One or more of 2547.

The present invention also provides the preparation method of above-mentioned coating, comprises the following steps:

(1) Add chitosan-modified cationic waterborne polyurethane resin represented by formula (I), water-based thickener, water-based defoamer, water-based leveling agent and water-based wetting agent into the stirring device, and obtain the mixture after 2-3 hours ;

(2) Add water-based co-solvent and water-based curing agent to the mixture, and stir for half an hour to obtain a coating.

In order to further illustrate the present invention, a kind of chitosan modified cationic waterborne polyurethane resin provided by the present invention, its preparation method and application are described in detail below in conjunction with the examples.

The reagents used in the following examples are all commercially available, and the chitosan used in the examples is low-viscosity chitosan.

Example 1

According to the method disclosed in Example 9 of Chinese Patent Application No. 201210086834.X, a carbon dioxide-based diol with a number average molecular weight of 2000 Daltons containing the structure of formula (6) was prepared.

Add 120 grams of prepared carbon dioxide-based diols with a molecular weight of 2000 Daltons into a four-neck flask, heat to 110°C, dehydrate at -0.98MPa for 1 hour, cool down to 78°C, and add 100 grams of Butanone and 16.0 grams of isophorone diisocyanate were reacted for 2 hours; then the temperature was lowered to 32° C., 0.0025 grams of dibutyltin dilaurate catalyst was added dropwise, and 7.95 grams of N-methyldiethanolamine was added in three batches. After the addition, the reaction 1 hour; then heat up to 75°C, add 2.53 grams of chitosan and 7.50 grams of butanediol, react for 2 hours, add trichloroacetic acid to neutralize the pH to 7, then add 300 grams of deionized water, stir at 1200rpm for 1 hour, and decompress Butanone is removed to obtain the chitosan modified cationic waterborne polyurethane resin shown in formula (I).

Utilize infrared spectrometer to detect the chitosan modified cationic waterborne polyurethane resin shown in the formula (I) that the embodiment of the present invention 1 prepares, obtain its infrared spectrogram as shown in Figure 1. It can be seen from Figure 1 that the infrared spectrum: 3371cm ^-1 , 2948cm ^-1 , 1745cm ^-1 , 1534cm ^-1 , 1460cm ^-1 , 1385cm ^-1 , 1245cm ^-1 , 1159cm ^-1 , 1121cm ^-1 , 1070cm ^-1 , 976cm ^-1 ,861cm ^-1 ,788cm ^-1 ,710cm ^-1 ,637cm ^-1 ,589cm ^-1 .

Example 2

According to the method disclosed in Example 9 of Chinese Patent Application No. 201210086834.X, a carbon dioxide-based diol with a number average molecular weight of 2000 Daltons containing the structure of formula (6) was prepared.

Add 185 grams of prepared carbon dioxide-based diols with a molecular weight of 2000 Daltons into a four-neck flask, heat to 105°C, dehydrate at -0.98MPa for 1 hour, cool down to 76°C, and add 110 grams of Butanone and 90 grams of 4,4'-dicyclohexylmethane diisocyanate were reacted for 2 hours; then the temperature was lowered to 38°C, 0.0025 grams of dibutyltin dilaurate catalyst was added dropwise, and 11.40 grams of N-phenyldiethanolamine was added in three batches. After the addition, react for 1 hour; then heat up to 72°C, add 7.10 grams of chitosan and 6.50 grams of butanediol, and react for 2 hours; add trifluoroacetic acid to neutralize the pH to 7, then add 300 grams of deionized water, and stir at 1200 rpm In 1 hour, butanone was removed under reduced pressure to obtain the chitosan-modified cationic waterborne polyurethane resin shown in formula (I).

Utilize infrared spectrum to detect the chitosan modified cationic waterborne polyurethane resin shown in the formula (I) that the embodiment of the present invention 2 prepares, obtain its infrared spectrogram as shown in Figure 2. It can be seen from Figure 2 that its infrared spectrum: 3367cm ^-1 , 2947cm ^-1 , 1749cm ^-1 , 1539cm ^-1 , 1454cm ^-1 , 1384cm ^-1 , 1244cm ^-1 , 1161cm ^-1 , 1120cm ^-1 , 1072cm ^-1 , 977cm ^-1 ,860cm ^-1 ,787cm ^-1 ,711cm ^-1 ,636cm ^-1 ,588cm ^-1 .

Example 3

According to the method of Example 17 disclosed in Chinese Patent Application No. 201110231493.6, a carbon dioxide-based diol with a number average molecular weight of 3500 Daltons containing the structure of formula (6) was prepared.

Add 185 grams of prepared carbon dioxide-based diols with a molecular weight of 3500 Daltons into a four-neck flask, heat to 110°C, dehydrate at -0.98MPa for 1 hour, cool down to 78°C, and add 160 grams of Butanone and 31.9 grams of 1,6-hexamethylene diisocyanate were reacted for 2 hours; then the temperature was lowered to 33°C, 0.0013 grams of dibutyltin dilaurate catalyst was added dropwise, and 6.35 grams of N-methyldiethanolamine was added in three batches. After the addition was completed, the reaction 1 hour; then heat up to 75°C, add 3.60 grams of chitosan and 5.98 grams of butanediol, and react for 2 hours; add glacial acetic acid to neutralize the pH to 7, then add 250 grams of deionized water, stir at 1200 rpm for 1 hour, and decompress Butanone is removed to obtain the chitosan modified cationic waterborne polyurethane resin shown in formula (I).

Utilize infrared spectrometer to detect the chitosan modified cationic waterborne polyurethane resin shown in the formula (I) prepared by the embodiment of the present invention 3, obtain its infrared spectrogram detection result: 3367cm ^-1 , 2943cm ^-1 , 1748cm ^-1 , 1536cm ^-1 ,1457cm ^-1 ,1384cm ^-1 ,1249cm ^-1 ,1164cm ^-1 ,1125cm ^-1 ,1075cm ^-1 ,979cm ^-1 ,864cm ^-1 ,788cm ^-1 ,715cm ^-1 ,636cm ^-1 ,589cm ^{- 1} .

Example 4

According to the method disclosed in Example 4 of the Chinese Patent Application No. 201210086834.X, a carbon dioxide-based diol with a number average molecular weight of 5000 Daltons containing the structure of formula (6) was prepared.

Add 120 grams of prepared carbon dioxide-based diols with a molecular weight of 5000 Daltons into a four-neck flask, heat to 110°C, dehydrate at -0.98MPa for 1 hour, cool down to 72°C, and add 125 grams of Butanone and 20.9 grams of isophorone diisocyanate were reacted for 2 hours; then the temperature was lowered to 34 ° C, 0.0010 grams of dibutyltin dilaurate catalyst was added dropwise, and 2.95 grams of N-methyldiethanolamine was added in three batches. After the addition, reaction 1 Then heat up to 76°C, add 1.29 grams of chitosan and 2.88 grams of butanediol, and react for 2 hours; add glacial acetic acid to neutralize the pH to 7, then add 220 grams of deionized water, stir at 1200rpm for 1 hour, and remove under reduced pressure Butanone, promptly obtains the chitosan modified cationic waterborne polyurethane resin shown in formula (I).

Utilize infrared spectrometer to detect the chitosan modified cationic waterborne polyurethane resin shown in the formula (I) prepared by the embodiment of the present invention 4, obtain its infrared spectrogram detection result: 3371cm ^-1 , 2945cm ^-1 , 1743cm ^-1 , 1540cm ^-1 ,1458cm ^-1 ,1385cm ^-1 ,1249cm ^-1 ,1163cm ^-1 ,1122cm ^-1 ,1075cm ^-1 ,978cm ^-1 ,860cm ^-1 ,787cm ^-1 ,712cm ^-1 ,639cm ^-1 ,586cm ^{- 1} .

Example 5

According to the method of Example 11 disclosed in Chinese Patent Application No. 201210086834.X, a carbon dioxide-based diol with a number average molecular weight of 1500 Daltons containing the structure of formula (6) was prepared.

Add 110 grams of prepared carbon dioxide-based diols with a molecular weight of 1500 Daltons into a four-neck flask, heat to 110°C, dehydrate at -0.98MPa for 1 hour, cool down to 75°C, and add 150 grams of Butanone and 65 grams of diphenylmethane diisocyanate were reacted for 2 hours; then the temperature was lowered to 35°C, 0.0015 grams of dibutyltin dilaurate catalyst was added dropwise, and 11.11 grams of N-butyldiethanolamine was added in three batches. After the addition, reaction 1 Then heat up to 70°C, add 3.59 grams of chitosan and 8.01 grams of butanediol, and react for 2 hours; add glacial acetic acid to neutralize the pH to 7, then add 210 grams of deionized water, stir at 1200rpm for 1 hour, and remove under reduced pressure Butanone, promptly obtains the chitosan modified cationic waterborne polyurethane resin shown in formula (I).

The chitosan-modified cationic waterborne polyurethane resin shown in formula (I) prepared in Example 5 of the present invention is detected by an infrared spectrometer, and its infrared spectrum results are obtained: 3368cm ^-1 , 2946cm ^-1 , 1748cm ^-1 , ^1541cm -1 ^{1,1454cm -} 1,1383cm ^- 1,1246cm ^{-1,1160cm- 1,1120cm -} 1,1078cm ^- 1,979cm ^- 1,861cm ^- 1,788cm ^- 1,713cm ^- 1,638cm ^- 1,588cm ^-1 .

Example 6

According to the method of Example 8 disclosed in the Chinese Patent Application No. 201210086834.X, a carbon dioxide-based diol with a number average molecular weight of 2800 Daltons containing the structure of formula (6) was prepared.

Add 150 grams of prepared carbon dioxide-based diols with a molecular weight of 2800 Daltons into a four-neck flask, heat to 110°C, dehydrate at -0.98MPa for 1 hour, cool down to 72°C, and add 200 grams of Butanone and 34 grams of toluene diisocyanate were reacted for 2 hours; then the temperature was lowered to 35°C, 0.0010 grams of dibutyltin dilaurate catalyst was added dropwise, and 6.60 grams of N-butyldiethanolamine was added in three batches, and the reaction was carried out for 1 hour after the addition was completed; then Heat up to 78°C, add 2.88 grams of chitosan and 6.44 grams of butanediol, react for 2 hours, add hydrochloric acid to neutralize the pH to 7, then add 230 grams of deionized water, stir at 1200 rpm for 1 hour, remove butanone under reduced pressure, that is Obtain the chitosan modified cationic waterborne polyurethane resin shown in formula (I).

The chitosan-modified cationic water-based polyurethane resin represented by formula (I) prepared in Example 6 of the present invention is detected by an infrared spectrometer, and the infrared spectrum results are obtained: 3368cm ^-1 , 2946cm ^-1 , 1746cm ^-1 , ^1537cm -1 ^{1,1455cm -} 1,1381cm ^- 1,1248cm ^{-1,1163cm- 1,1120cm -} 1,1074cm ^- 1,976cm ^- 1,861cm ^- 1,789cm ^- 1,713cm ^- 1,636cm ^- 1,587cm ^-1 .

Comparative example 1 waterborne polyurethane resin synthesis

The preparation method is the same as in Example 3, except that the carbon dioxide-based diol with the structure of formula (6) is replaced with polybutylene adipate.

Comparative example 2 waterborne polyurethane resin synthesis

The preparation method is the same as in Example 4, except that the carbon dioxide-based diol with the structure of formula (6) is replaced with polypropylene glycol.

Comparative Example 3 Synthesis of Waterborne Polyurethane Resin

The preparation method is the same as in Example 1, except that chitosan is replaced by butanediol.

Example 7

Waterborne polyurethane coating preparation

Press the material ratio of table 1, prepare waterborne polyurethane coating in the following way:

(1) 70-90 parts by weight of water-based polyurethane, 0.6-1.9 parts by weight of water-based thickener, 0.1-0.6 parts by weight of water-based defoamer, 0.1-0.3 parts by weight of water-based leveling agent and 0.3-0.6 parts by weight Parts of water-based wetting agent are added to the stirring device, and the mixture is obtained after 2 to 3 hours;

(2) Add 6 to 10 parts by weight of water-based cosolvent and 2 to 6 parts by weight of water-based curing agent to the mixture, and stir for half an hour to obtain water-based polyurethane coatings, respectively denoted as WPU-1, WPU-2, and WPU -3, WPU-4, WPU-5, WPU-6; DB1, DB2, DB3. Coat carbon dioxide-based water-based polyurethane coatings WPU-1, WPU-2, WPU-3, WPU-4, WPU-5, WPU-6 and DB1, DB2, DB3 evenly on a polytetrafluoroethylene tray with a thickness of 150~ 200 μm, placed at room temperature for 5 days, and then completely dried in a vacuum oven at 50°C for 8 hours, the obtained coating film was tested for tensile properties and water resistance. The results are shown in Table 2. Among them, the water resistance test of the coating film: the dried coating film is made into a dumbbell-shaped spline and weighed as W ₀ , placed in deionized water at room temperature for 24 hours and then weighed as W ₁ , water absorption (%)= (W ₁ -W ₀ )/W ₀ *100%.

Table 1 water-based polyurethane coating material composition ratio

Table 2 waterborne polyurethane coating performance test results

project WPU1 WPU2 WPU3 WPU4 WPU5 WPU6 DB1 DB2 DB3 Elongation at break (%) 490 610 480 510 540 550 310 700 470 Tensile strength (MPa) 37 35 41 39 40 42 28 19 30 Water absorption (%) 9.1 10.1 8.8 9.0 9.4 9.9 40.9 32.5 12.1

Claims (9)

1. a kind of chitin modified cation aqueous polyurethane resin, as shown in formula (I)：

-R₁- selected from the one kind in following structure：

-R₂- as shown in formula (6)：

M is that 1~30, z is 1~35；

R₃Selected from one or more in following structure：

Cl formulas (10)；

-R₄Selected from the one kind in following structure：

-CH₃Formula (11)；

A is 1~4 integer；

N is 2~200 integer.

2. a kind of preparation method of chitin modified cation aqueous polyurethane resin, it is characterised in that comprise the following steps：

S1) in protective atmosphere, by the diisocyanate shown in the carbon dioxide-base dihydroxylic alcohols of contained (6) structure and formula (II) Mixing, heating response obtains the first product；

S2) first product and the hydrophilic chain extender shown in formula (III) are reacted under conditions of catalyst presence, the is obtained Two products；

S3) the glycol Hybrid Heating shown in second product, shitosan and formula (IV) is reacted, third product is obtained；

S4) mixing the third product with acid carries out neutralization reaction, after emulsification, obtains the chitin modified sun shown in formula (I) Ion waterborne polyurethane resin；

OCN-R₁- NCO formulas (II)；

-R₁- selected from the one kind in following structure：

-R₂- as shown in formula (6)：

M is that 1~30, z is 1~35；

R₃Selected from one or more in following structure：

Cl formulas (10)；

-R₄Selected from the one kind in following structure：

-CH₃Formula (11)；

A is 1~4 integer；

N is 2~200 integer.

3. preparation method according to claim 2, it is characterised in that the carbon dioxide-base two of contained (6) structure The molecular weight of first alcohol is 1500~5000 dalton.

4. preparation method according to claim 2, it is characterised in that the step S1) in the temperature of heating response be 70 DEG C~80 DEG C；The time of the heating response is 1.5~3h；

The step S2) in reaction temperature be 30 DEG C~40 DEG C；The time of the reaction is 1~2h；

The step S3) in heating response temperature be 65 DEG C~85 DEG C；The time of the heating response is 1.5~2h.

5. preparation method according to claim 2, it is characterised in that the carbon dioxide-base two of contained (6) structure First alcohol is (110~185) with the mass ratio of the diisocyanate shown in formula (II)：(16~92)；

Hydrophilic chain extender shown in the formula (III) is with the mass ratio of the carbon dioxide-base dihydroxylic alcohols of contained (6) structure： (2.95~11.40)：(110~185)；

The shitosan is (2.95~11.40) with the mass ratio of the carbon dioxide-base dihydroxylic alcohols of contained (6) structure：(110~ 185)。

6. preparation method according to claim 2, it is characterised in that the step S2) in catalyst be tin dilaurate Dibutyl tin.

7. preparation method according to claim 2, it is characterised in that the step S5) it is specially：

The third product is mixed with acid after carrying out neutralization reaction, the stirring that adds water is emulsified, obtain the shell shown in formula (I) and gather Sugared modified cation waterborne polyurethane resin；The speed of the stirring is 1200~1800rpm；The time of the stirring is 0.5 ~2h.

8. the chitin modified cation aqueous polyurethane resin or claim 2~7 any one described in claim 1 are made Application of the standby chitin modified cation aqueous polyurethane resin in coating.

9. application according to claim 8, it is characterised in that the coating includes：

-R₁- selected from the one kind in following structure：

-R₂- as shown in formula (6)：

M is that 1~30, z is 1~35；

R₃Selected from one or more in following structure：

Cl formulas (10)；

-R₄Selected from the one kind in following structure：

-CH₃Formula (11)；

A is 1~4 integer；

N is 2~200 integer.