1. The self-fragrant multi-dendritic polymer fatliquor is characterized in that the molecular structure of active ingredients in the self-fragrant multi-dendritic polymer fatliquor is as follows:

wherein n ≧ 1.

2. The preparation method of the self-fragrant multi-dendritic polymer fatliquor is characterized by comprising the following reaction steps of:

(1) performing esterification, namely adding citric acid esters, single-chain terpene alcohol and alkenyl dianhydride into a 1000ml three-necked bottle, adding an organic solvent for dispersion, heating to 80-90 ℃, then adding an organic acid catalyst, and controlling the temperature to react for 0.5-2 hours; continuously heating to 100-120 ℃, and reacting for 1-4 h; after the reaction is finished, cooling to 80-90 ℃ to obtain citric acid ester single-chain terpene alcohol alkenyl diester;

(2) performing free radical polymerization reaction, controlling the temperature to be 70-90 ℃, and filling nitrogen into a three-mouth bottle for replacement; adding the oil-soluble initiator into a three-mouth bottle, and uniformly stirring; then dropwise adding acrylic acid monomers into a three-mouth bottle at a constant speed for 1-3 h; after the acrylic monomer is dripped, controlling the temperature to be 70-90 ℃, stirring and reacting for 1-4 h, vacuumizing to-0.04-0.06 MPa, and continuing to react for 2-4 h;

(3) and (3) carrying out neutralization reaction, removing vacuum, cooling to 50-60 ℃, dropwise adding a neutralizing agent liquid into a three-necked bottle, adjusting the pH to 6.0-8.0, adding deionized water into the three-necked bottle, adjusting the solid content of the system, stirring for 0.5-1 h, continuously cooling to below 40 ℃, and discharging to obtain the self-fragrant multi-dendritic polymer fatliquor.

3. The method for preparing the self-fragrant multi-dendritic polymer fatliquor according to claim 2, wherein the molar ratio of the citric acid esters, the single-chain terpene alcohol and the alkenyl dianhydride in the step (1) is 1: 0.3-1: 0.5-1.

4. A method of preparing a self-odorous multi-dendritic polymeric fatliquor according to claim 3, characterized in that the citrate esters are one or more of triethyl citrate, tributyl citrate, citric acid glycerol stearate, stearyl citrate, tri (octyldodecanol) citrate; the single-chain terpene alcohol is one or more of linalool, citronellol, geraniol, nerol and lavender alcohol; the alkenyl dianhydride is one or more of maleic anhydride, allyl succinic anhydride, 2-octenyl succinic anhydride, dodecenyl succinic anhydride and norbornene dianhydride.

5. The method according to claim 2, wherein the amount of the organic acid catalyst used in step (1) is 0.5-2% by mass of the total mass of the reaction materials.

6. The method for preparing a self-fragrant multi-dendritic polymer fatliquor according to claim 2, wherein the organic solvent in the step (1) is one or more of ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether and diethylene glycol butyl ether.

7. The method according to claim 2, wherein the amount of the oil-soluble initiator used in step (2) is 0.5-2% of the amount of the acrylic monomer.

8. The method for preparing a self-fragrant multi-dendritic polymer fatliquor according to claim 2, wherein the dropping amount of the acrylic monomer in the step (2) is as follows: the molar ratio of the acrylic acid monomer to the alkenyl dianhydride in the step (1) is 1-1.5: 1.

9. The method according to claim 2, wherein the neutralizing agent liquid in step (3) is one or more of 18% ammonia solution, 25% ammonia solution, 32% NaOH solution and 48% NaOH solution.

Background

The tanning process mainly comprises the working procedures of batching, soaking, liming, unhairing, reliming, fleshing, deliming, softening, pickling, chrome tanning, neutralizing, retanning, fatliquoring, dyeing, coating and the like. The greasing agent covers the surface of the collagen fiber of the leather through winding and film forming, so that the friction coefficient and the interfacial tension between the collagen fibers are reduced, and the finished leather has good softness, fullness and other special properties. With the development of the leather industry, people can not meet the traditional fatliquoring agent with single function, and higher requirements are put forward on the performance, quality and special function of the fatliquoring agent. The polymer fatting agent is more and more valued by people because of the controllable structure and function, and the combination of the advantages of strong collagen fiber capacity, plump finished leather, solvent resistance and the like.

The traditional fragrant fatliquor is prepared by a physical blending method of fatliquor and essence, and has the defect of poor storage and application stability. Because the essence and the leather collagen fiber have poor binding property and low absorption rate, the additional burden of wastewater treatment is increased. The essence in the leather after fatliquoring continuously volatilizes and loses efficacy, the fragrance is not lasting, and meanwhile, the VOC detection value in the leather is increased. Along with the improvement of requirements of people on the functions and the environmental protection performance of the fatliquor, the application of the traditional fragrant fatliquor is more and more limited.

Disclosure of Invention

In order to overcome the defects of the prior art, the self-fragrant multi-branched polymer fatting agent and the preparation method thereof are provided by using the advantages of controllable structure and function of the polymer fatting agent, strong capability of combining collagen fibers, plump finished leather, solvent resistance and the like and taking citric acid esters, single-chain terpene alcohol and alkenyl diacid anhydride as main raw materials through esterification reaction, free radical polymerization and neutralization reaction.

The invention provides a self-fragrant multi-dendritic polymer fatting agent, wherein the molecular structure of effective components in the self-fragrant multi-dendritic polymer fatting agent is schematically shown as follows:

wherein n ≧ 1.

The invention also discloses a preparation method of the self-fragrant multi-dendritic polymer fatliquor, which comprises the following reaction steps:

(1) performing esterification, namely adding citric acid esters, single-chain terpene alcohol and alkenyl dianhydride into a 1000ml three-necked bottle, adding an organic solvent for dispersion, heating to 80-90 ℃, then adding an organic acid catalyst, and controlling the temperature to react for 0.5-2 hours; continuously heating to 100-120 ℃, and reacting for 1-4 h; after the reaction is finished, cooling to 80-90 ℃ to obtain citric acid ester single-chain terpene alcohol alkenyl diester;

(2) performing free radical polymerization reaction, controlling the temperature to be 70-90 ℃, and filling nitrogen into a three-mouth bottle for replacement; adding the oil-soluble initiator into a three-mouth bottle, and uniformly stirring; then dropwise adding acrylic acid monomers into a three-mouth bottle at a constant speed for 1-3 h; after the acrylic monomer is dripped, controlling the temperature to be 70-90 ℃, stirring and reacting for 1-4 h, vacuumizing to-0.04-0.06 MPa, and continuing to react for 2-4 h;

(3) and (3) carrying out neutralization reaction, removing vacuum, cooling to 50-60 ℃, dropwise adding the neutralizer liquid into a three-necked bottle, and adjusting the pH to 6.0-8.0 to ensure that the system has better water solubility. And adding deionized water into a three-neck flask, adjusting the solid content of the system, stirring for 0.5-1 h, continuously cooling to below 40 ℃, and discharging to obtain the self-fragrant multi-dendritic polymer fatting agent.

Preferably, the molar ratio of the citric acid esters to the mono-terpene alcohol to the alkenyl dianhydride in the step (1) is 1: 0.3-1: 0.5-1.

Preferably, the citrate esters are one or more of triethyl citrate, tributyl citrate, citric acid glycerol stearate, stearyl citrate and tri (octyldodecanol) citrate; the single-chain terpene alcohol is one or more of linalool, citronellol, geraniol, nerol and lavender alcohol; the alkenyl dianhydride is one or more of maleic anhydride, allyl succinic anhydride, 2-octenyl succinic anhydride, dodecenyl succinic anhydride and norbornene dianhydride.

Preferably, the amount of the organic acid catalyst used in the step (1) is 0.5-2% of the total mass of the reaction substances.

Preferably, the organic solvent in step (1) is one or more of ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether and diethylene glycol butyl ether.

Preferably, the amount of the oil-soluble initiator in the step (2) is 0.5-2% of the amount of the acrylic monomer.

Preferably, the dropping amount of the acrylic monomer in the step (2) is: the molar ratio of the acrylic acid monomer to the alkenyl dianhydride in the step (1) is 1-1.5: 1.

Preferably, the neutralizing agent liquid in the step (3) is one or more of 18% ammonia water solution, 25% ammonia water solution, 32% NaOH solution and 48% NaOH solution.

Compared with the prior art, the invention has the advantages and the technical effects that:

(1) the preparation technical route and the product structure of the invention are novel, the single-chain terpene alcohol with fresh fragrance and the cosmetic-grade citrate are introduced into the molecular structure of the polymer fatting agent through esterification reaction, so that the fatting agent has lasting fragrance, VOC in leather can not be increased, and the obtained polymer fatting agent has good heart penetration softness and moist surface hand feeling.

(2) Hydrophilic carboxyl is introduced into the multi-branched molecular structure of the polymer fatliquor by a free radical polymerization method, so that the hydrophilicity of the fatliquor and the binding function with collagen fibers are improved. The multi-branch structure of the self-fragrant multi-branch polymer fatting agent can enhance the function of combining with collagen fibers, has high absorption rate, can effectively reduce the COD of the tanning production wastewater, and meets the requirement of clean production.

(3) The preparation process is carried out in a solvent through esterification reaction and free radical copolymerization reaction, and the solvent is recovered through reduced pressure distillation, so that the solvent is recovered and recycled, and the environmental pollution is avoided; and after the self-fragrant multi-branched polymer fatliquor is fatliquored, the leather keeps a fresh fragrance with strong permeability for a long time, and is a preferred material for fatliquoring high-grade sofa leather, automobile cushion leather, clothing leather and bag leather.

Detailed Description

The present invention will be further described with reference to specific examples, but the scope of the present invention is not limited to the examples. Other variations and modifications which would occur to those skilled in the art without departing from the spirit and scope of the invention are also included within the scope of the invention.

The molecular structure of the effective components of the self-fragrant multi-dendritic polymer fatliquor in the following examples is schematically shown as follows:

wherein n is more than or equal to 1.

The self-fragrant multi-branched polymer fatting agent is prepared by taking citric acid esters, single-chain terpene alcohol, alkenyl diacid anhydride, (methyl) acrylic acid, an organic acid catalyst, an oil-soluble initiator and neutralizing agent liquid as raw materials and taking an organic solvent as a dispersing agent through esterification reaction, free radical polymerization reaction and neutralization reaction, wherein the citric acid esters are one or more of triethyl citrate, tributyl citrate, citric acid stearate, citric acid stearyl ester and tri (octyldodecanol) citrate; the single-chain terpene alcohol is one or more of linalool, citronellol, geraniol, nerol and lavender alcohol; the alkenyl dianhydride is one or more of maleic anhydride, allyl succinic anhydride, 2-octenyl succinic anhydride, dodecenyl succinic anhydride and norbornene dianhydride.

The acrylic acid monomer is one or more of methacrylic acid and acrylic acid; the organic acid catalyst is one or more of p-toluenesulfonic acid and trifluoromethanesulfonic acid; the oil-soluble initiator is one or more of azobisisobutyronitrile, azobisisoheptonitrile, benzoyl peroxide and dibenzoyl peroxide; the organic solvent is a green environment-friendly solvent and is one or more of ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether and diethylene glycol butyl ether; the neutralizing agent liquid is one or more of 18% ammonia water solution, 25% ammonia water solution, 32% NaOH solution and 48% NaOH solution. In the preparation process, the reaction mechanism of the first esterification reaction is as follows:

in the second step, the reaction mechanism of the free radical polymerization reaction is as follows:

wherein AIBN is azobisisobutyronitrile;

and step three, the reaction mechanism of the neutralization reaction is as follows:

example 1

(1) And (4) performing esterification reaction. 180.22 parts of tributyl citrate, 77.13 parts of linalool and 25.73 parts of maleic anhydride are added into a 1000mL three-necked bottle provided with a thermometer, a stirring device and a reflux condenser tube, and the mixture is stirred uniformly. Then adding 50 parts of ethylene glycol tertiary butyl ether, heating to 85 ℃, and uniformly stirring. Adding 2.83 parts of p-toluenesulfonic acid, controlling the temperature to be 85 +/-2 ℃, and reacting for 2 hours in a timing manner. The temperature is continuously increased to 110 ℃, and the reaction is stirred for 1 h. Cooling to 85 +/-2 ℃ to obtain the linalool citrate maleate diester.

(2) And (3) performing free radical polymerization. Controlling the temperature to 85 +/-2 ℃, and filling nitrogen into the three-mouth bottle for replacement for 10 min. 0.2 part of oil-soluble initiator azobisisobutyronitrile is added into a three-necked bottle and stirred for 5 min. And (3) dropwise adding 19.85 parts of acrylic acid into a three-necked bottle at a constant speed for 1.5 hours, controlling the temperature to be 85 +/-2 ℃ after the dropwise addition is finished, and stirring for reacting for 2 hours. Vacuumizing to-0.04-0.06 MPa, and continuing to react for 2 h.

(3) And (4) neutralizing. Removing vacuum, cooling to 50-60 ℃, dropwise adding 36.3 parts of 48% NaOH solution into a three-necked bottle, and controlling the temperature to be less than 60 ℃. After the dropwise addition is finished, the temperature is controlled to be 50-60 ℃, the stirring is carried out for 0.5h, and the pH value is adjusted to be 6.0-8.0, so that the system has better water solubility. 304.5 parts of deionized water is added into a three-necked bottle, stirred for 0.5h, and the solid content is adjusted to 50%. And continuously cooling to below 40 ℃, and discharging to obtain the self-fragrant multi-dendritic polymer fatting agent.

Example 2

(1) And (4) performing esterification reaction. 275.34 parts of glyceryl stearate citrate, 61.7 parts of linalool and 25.73 parts of maleic anhydride are added into a 1000mL three-necked flask provided with a thermometer, a stirring device and a reflux condenser tube, and the mixture is stirred uniformly. Then adding 50 parts of ethylene glycol tertiary butyl ether, heating to 90 ℃, and uniformly stirring. 3.63 parts of p-toluenesulfonic acid is added, the temperature is controlled to 90 +/-2 ℃, and the reaction is carried out for 1 hour in a timing manner. The temperature is continuously increased to 115 ℃, and the reaction is stirred for 3 hours. Cooling to 90 +/-2 ℃ to obtain the linalool citrate maleate diester.

(2) And (3) performing free radical polymerization. Controlling the temperature to 90 +/-2 ℃, and filling nitrogen into the three-mouth bottle for replacement for 10 min. 0.37 part of oil-soluble initiator benzoyl peroxide is added into a three-necked bottle and stirred for 5 min. And dropwise adding 24.57 parts of acrylic acid into a three-necked bottle at a constant speed for 1.5 hours, controlling the temperature to be 90 +/-2 ℃ after the dropwise addition is finished, and stirring for reacting for 3 hours. Vacuumizing to-0.04-0.06 MPa, and continuing to react for 2 h.

(3) And (4) neutralizing. Removing vacuum, cooling to 50-60 ℃, dropwise adding 40.9 parts of 48% NaOH solution into a three-necked bottle, and controlling the temperature to be less than 60 ℃. After the dropwise addition is finished, the temperature is controlled to be 50-60 ℃, the stirring is carried out for 0.5h, and the pH value is adjusted to be 6.0-8.0, so that the system has better water solubility. 252.71 parts of deionized water are added into a three-necked bottle, stirred for 0.5h and the solid content is adjusted to 60 percent. And continuously cooling to below 40 ℃, and discharging to obtain the self-fragrant multi-dendritic polymer fatting agent.

Example 3

(1) And (4) performing esterification reaction. 221 parts of stearyl citrate, 77.13 parts of linalool and 26.96 parts of maleic anhydride are added into a 1000mL three-necked flask provided with a thermometer, a stirring device and a reflux condenser, the temperature is raised to 60 ℃, and the mixture is stirred uniformly. Then adding 50 parts of ethylene glycol tertiary butyl ether, heating to 90 ℃, and uniformly stirring. 4.88 parts of p-toluenesulfonic acid is added, the temperature is controlled to 90 +/-2 ℃, and the reaction is carried out for 2 hours in a timing manner. The temperature is continuously increased to 105 ℃, and the reaction is stirred for 2 hours. Cooling to 88 +/-2 ℃ to obtain the linalool citrate maleate diester.

(2) And (3) performing free radical polymerization. Controlling the temperature to 88 +/-2 ℃, and filling nitrogen into the three-mouth bottle for replacement for 10 min. 0.35 part of oil-soluble initiator azobisisobutyronitrile is added into a three-necked bottle and stirred for 5 min. And dropwise adding 24.57 parts of acrylic acid into a three-necked bottle at a constant speed for 1.5 hours, controlling the temperature to be 88 +/-2 ℃ after the dropwise addition is finished, and stirring for reacting for 1 hour. Vacuumizing to-0.04-0.06 MPa, and continuing to react for 3 h.

(3) And (4) neutralizing. Removing vacuum, cooling to 50-60 ℃, and dripping 41.72 parts of 48% NaOH solution into a three-necked bottle, and controlling the temperature to be less than 60 ℃. After the dropwise addition is finished, the temperature is controlled to be 50-60 ℃, the stirring is carried out for 0.5h, and the pH value is adjusted to be 6.0-8.0, so that the system has better water solubility. 353.17 parts of deionized water are added into a three-necked bottle, stirred for 0.5h and the solid content is adjusted to 50%. And continuously cooling to below 40 ℃, and discharging to obtain the self-fragrant multi-dendritic polymer fatting agent.

Example 4

(1) And (4) performing esterification reaction. 180.22 parts of tributyl citrate, 77.13 parts of linalool and 25.73 parts of maleic anhydride are added into a 1000mL three-necked bottle provided with a thermometer, a stirring device and a reflux condenser, the temperature is raised to 60 ℃, and the mixture is stirred uniformly. Then adding 50 parts of ethylene glycol tertiary butyl ether, heating to 80 ℃, and uniformly stirring. Adding 2.83 parts of p-toluenesulfonic acid, controlling the temperature to be 80-85 ℃, and reacting for 1 hour in a timing manner. The temperature is continuously increased to 115 ℃, and the reaction is stirred for 3 hours. Cooling to 90 +/-2 ℃ to obtain the linalool citrate maleate diester.

(2) And (3) performing free radical polymerization. Controlling the temperature to 90 +/-2 ℃, and filling nitrogen into the three-mouth bottle for replacement for 10 min. 0.2 part of oil-soluble initiator azobisisobutyronitrile is added into a three-necked bottle and stirred for 5 min. And (3) dropwise adding 19.85 parts of methacrylic acid into a three-necked bottle at a constant speed for 1.5h, controlling the temperature to be 90 +/-2 ℃ after the dropwise addition is finished, and stirring for reacting for 3 h. Vacuumizing to-0.04-0.06 MPa, and continuing to react for 2 h.

(3) And (4) neutralizing. Removing vacuum, cooling to 50-60 ℃, dropwise adding 36.3 parts of 48% NaOH solution into a three-necked bottle, and controlling the temperature to be less than 60 ℃. And after the dropwise addition is finished, controlling the temperature to be 50-60 ℃, stirring for 0.5h, and adjusting the pH value to be 6.0-8.0. 245.7 parts of deionized water is added into a three-necked bottle, stirred for 0.5h, and the solid content is adjusted to 55 percent. And continuously cooling to below 40 ℃, and discharging to obtain the self-fragrant multi-dendritic polymer fatting agent.

The greasing agent prepared by the method can endow leather with the functions of heart-through softness, moist hand feeling, high bonding rate and lasting fragrance. Among them, citrate esters are often used as raw materials for producing cosmetics, have the function of moistening and protecting skin, and can endow leather with heart-through softness and moist hand feeling. The single-chain terpene alcohol is one of the most used fragrances in the world, and has the characteristics of strong greenness, sweet smell of wood, soft fragrance, light fragrance, full hair and the like. The polymer fatting agent is prepared by taking the citric acid esters and the single-chain terpene alcohol as main raw materials, so that the durability of faint scent of the single-chain terpene alcohol can be enhanced, and the leather can be endowed with heart-through softness and moist surface hand feeling. The obtained product can be used for producing high-grade leather and has good market prospect.

The application process comprises the following steps: putting the neutralized wet cattlehide into a rotary drum, adding 1-2% of dye and 8-10% of self-fragrant multi-branched polymer fatting agent by weight of the cattlehide, rotating for 60 minutes, adding 1-2% of formic acid by weight of the cattlehide to adjust the pH value to 3.8-4.0, and washing out the cattlehide with water. After drying, dampening and milling. The application result shows that the self-fragrant multi-dendritic polymer fatting agent can endow leather with core-penetration softness and moist surface hand feeling. The greased leather sample still has pleasant faint scent after being naturally stored for 6 months, and has strong persistence. The aromatic multi-branch polymer fatting agent has a multi-branch structure, less molecular chain winding and difficult crystallization, greatly improves the solubility and increases the permeability of the polymer fatting agent. Meanwhile, as a large number of carboxyl groups exist on the molecular branched chain of the self-fragrant multi-dendritic polymer fatting agent, the self-fragrant multi-dendritic polymer fatting agent can be chemically combined with active groups on collagen fibers and can be subjected to complex reaction with trivalent chromium ions, the combination function with the collagen fibers can be enhanced, and the absorption rate is high. The waste liquid is clear after the fatliquoring, the COD of the tannery wastewater can be effectively reduced, and the requirements of clean production are met.

The above description is only an example of the present invention, and is not intended to limit the present invention in any way, and those skilled in the art can make many variations and modifications of the present invention without departing from the scope of the present invention by using the method disclosed above, and the present invention is covered by the claims.