阅读说明：本技术 一种两性有机硅改性丙烯酸树脂复鞣剂及其制备方法 (Amphoteric organic silicon modified acrylic resin retanning agent and preparation method thereof ) 是由 张达 郭连娣 贺卫勃 沈扬 于 2021-10-09 设计创作，主要内容包括：本发明公开了一种两性有机硅改性丙烯酸树脂复鞣剂及其制备方法,该制备方法主要是首先制备枝形氨基硅油,然后再制备改性枝形氨基硅油,最后将制得的改性枝形氨基硅油、乳化剂、丙烯酸酯类单体和去离子水,采用氧化-还原引发体系分步进行共聚反应,得到两性有机硅改性丙烯酸树脂复鞣剂。本发明制备出的复鞣剂可保持铬鞣皮革原有的各种性能,兼具有机硅树脂和丙烯酸树脂材料的优良性能,不但具有较好的选择填充作用,边腹部不会松面,可以很好地填充于皮革结构松弛的部位,而且成革柔软、丰满,摸上去有滑爽感,并且含有的阴阳离子使得皮革在复鞣时不败色。(The invention discloses an amphoteric organic silicon modified acrylic resin retanning agent and a preparation method thereof. The retanning agent prepared by the invention can keep various original performances of chrome tanned leather, has excellent performances of organic silicon resin and acrylic resin materials, has a good selective filling effect, can not loosen the surface of the edge and the abdomen, can be well filled in the loose part of the leather structure, is soft and full in finished leather and smooth to touch, and contains anions and cations to ensure that the leather is not discolored during retanning.)

1. The preparation method of the amphoteric organic silicon modified acrylic resin retanning agent is characterized by comprising the following steps:

(1) preparation of branched amino silicone oil

The raw materials and the weight percentage content are as follows:

according to the percentage content of the raw materials, adding octamethylcyclotetrasiloxane, branched silane, aminosilane, 1/2 catalyst and deionized water into a first reaction vessel, reacting for 1-2 hours at the temperature of 100-110 ℃, then adding active silane and the rest catalyst, and continuing to react for 3-5 hours to obtain branched amino silicone oil; wherein the molar ratio of the deionized water to the octamethylcyclotetrasiloxane is 1: 1;

(2) preparation of modified branched amino silicone oil

Adding epoxy chloropropane and ethanol in a preset proportion into a second reaction container, stirring and heating to 50-70 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4-5 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain modified branched amino silicone oil; wherein the mass ratio of the epichlorohydrin to the branched amino silicone oil is 1: 0.8-1.2;

(3) preparation of amphoteric organic silicon modified acrylic resin retanning agent

Adding deionized water into the modified branched amino silicone oil obtained in the step (2), heating to 55-80 ℃ under the protection of inert gas after dispersion, adding 1/5 initiator, activating for half an hour, then respectively dropwise adding acrylic monomers and the rest of initiator, and continuing to react for 1-3 hours after completing dropwise addition to obtain the amphoteric organic silicon modified acrylic resin retanning agent; wherein the weight ratio of the acrylate monomer to the modified branched amino silicone oil is 1:0.1-0.5, and the mass of the initiator is 0.1-0.8% of the mass of the acrylate monomer.

2. The method for preparing the amphoteric organosilicon modified acrylic resin retanning agent according to claim 1, wherein the active silane is at least one of vinyl dimethylethoxysilane, methacryloxypropyl dimethylmethoxysilane, and methacryloxypropyl dimethylethoxysilane.

3. The method for preparing amphoteric organosilicon modified acrylic resin retanning agent according to claim 1, wherein the aminosilane is N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane.

4. The ampholytic according to claim 1The preparation method of the organic silicon modified acrylic resin retanning agent is characterized in that the branched silane is CH₃(CH₂)_nSi(OCH₃)₃Or CH₃(CH₂)_nSi(OCH₂CH₃)₃Wherein n is an integer of 0 to 3.

5. The method for preparing amphoteric silicone-modified acrylic resin retanning agent according to claim 1, wherein the catalyst is potassium hydroxide.

6. The preparation method of the amphoteric organic silicon modified acrylic resin retanning agent according to claim 1, wherein the acrylate monomer is a mixture of acrylic acid, methacrylic acid and acrylamide, wherein the mass ratio of the acrylic acid, the methacrylic acid and the acrylamide is 50-60:20-30: 10-20.

7. The preparation method of the amphoteric organic silicon modified acrylic resin retanning agent according to claim 1, wherein the initiator is a mixture of ammonium persulfate and urea or a mixture of ammonium persulfate and sodium sulfite, and the mass ratio of the ammonium persulfate to the urea or the sodium sulfite is 1: 1-6.

8. An amphoteric organic silicon-modified acrylic resin retanning agent, which is a dendrimer obtained by the method for producing an amphoteric organic silicon-modified acrylic resin retanning agent according to any one of claims 1 to 7.

9. The amphoteric silicone-modified acrylic resin retanning agent according to claim 8, characterized in that the amphoteric silicone-modified acrylic resin retanning agent has the structure:

wherein a/b/c/d/e/f/g/h are integers.

Technical Field

The invention belongs to the field of retanning agents for leather making, and particularly relates to an amphoteric organic silicon modified acrylic resin retanning agent and a preparation method thereof.

Background

In the tanning production process, retanning is one of the extremely important processes, can influence the properties of leather from multiple aspects, improves the appearance and the internal quality of the leather, and obtains the general attention of domestic and foreign tanning professionals. With the development of the leather-making industry, people put higher requirements on the color, softness, fullness, elasticity, bleaching, light resistance and the like of leather, and the traditional chrome tanning agent can not meet the requirements of high-grade leather.

The leather retanning agent is of various varieties, wherein the synthetic tanning agent is a main component of the retanning agent and is also the most applied retanning agent in modern leather production, and the acrylic polymer retanning agent is one of the most popular varieties in the synthetic tanning agent. Although some progress is made in recent years, the problems that the acrylic resin retanning agent is easy to make leather boards hard and leather fibers crisp, and particularly to make leather fibers lose color in the tanning process always plague the majority of tanning enterprises. Therefore, efforts have been made to modify acrylic resin retanning agents with other types of polymers to address the deficiencies in performance of such products and to impart new properties thereto.

Disclosure of Invention

The invention aims to provide an amphoteric organic silicon modified acrylic resin retanning agent and a preparation method thereof, the obtained organic silicon modified acrylic resin retanning agent has the performance advantages of organic silicon and acrylic resin materials, and on the molecular chain of the amphoteric organic silicon modified acrylic resin, not only carboxyl groups with anions but also quaternary ammonium salts with cations exist, so that the problem of color losing of the acrylic resin retanning agent is fundamentally solved.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of an amphoteric organic silicon modified acrylic resin retanning agent comprises the following steps:

(1) preparation of branched amino silicone oil

The raw materials and the weight percentage content are as follows:

according to the percentage content of the raw materials, octamethylcyclotetrasiloxane, branched-chain silane, aminosilane, 1/2 catalyst and deionized water are added into a first reaction container, and after reaction for 1-2 hours at the temperature of 100-110 ℃, active silane and the rest 1/2 catalyst are slowly added, the reaction is continued for 3-5 hours, the obtained viscous liquid is branched amino silicone oil, and then the viscous liquid is cooled to the room temperature and discharged; wherein the molar ratio of the deionized water to the octamethylcyclotetrasiloxane is 1: 1;

(2) preparation of modified branched amino silicone oil

Adding epoxy chloropropane and ethanol in a preset ratio into a second reaction container, uniformly stirring, heating to 50-70 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4-5 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain modified branched amino silicone oil; wherein the mass ratio of the epichlorohydrin to the branched amino silicone oil is 1: 0.8-1.2;

(3) preparation of amphoteric organic silicon modified acrylic resin retanning agent

Adding deionized water into the modified branched amino silicone oil obtained in the step (2), fully dispersing, heating to 55-80 ℃ under the protection of inert gas, adding 1/5 initiator, activating for half an hour, then respectively dropwise adding acrylic monomers and the rest of 4/5 initiator, and continuing to react for 1-3 hours after completing dropwise adding to obtain the amphoteric organic silicon modified acrylic resin retanning agent; wherein the weight ratio of the acrylate monomer to the modified branched amino silicone oil is 1:0.1-0.5, and the mass of the initiator is 0.1-0.8% of the mass of the acrylate monomer.

Optionally, the reactive silane is at least one of vinyl dimethylethoxysilane, methacryloxypropyl dimethylmethoxysilane, methacryloxypropyl dimethylethoxysilane.

Optionally, the aminosilane is N- β - (aminoethyl) - γ -aminopropylmethyldimethoxysilane.

Optionally, the branched silane is CH₃(CH₂)_nSi(OCH₃)₃Or CH₃(CH₂)_nSi(O CH₂CH₃)₃Wherein n is an integer of 0 to 3.

Optionally, the catalyst is potassium hydroxide.

Optionally, the acrylate monomer is a mixture of acrylic acid, methacrylic acid and acrylamide, wherein the mass ratio of the acrylic acid to the methacrylic acid to the acrylamide is 50-60:20-30: 10-20.

Optionally, the initiator is a mixture of ammonium persulfate and urea or a mixture of ammonium persulfate and sodium sulfite, and the mass ratio of the ammonium persulfate to the urea or the sodium sulfite is 1: 1-6.

The amphoteric organic silicon modified acrylic resin retanning agent is a tree-shaped organic matter obtained by the preparation method of the amphoteric organic silicon modified acrylic resin retanning agent.

Wherein the amphoteric organic silicon modified acrylic resin retanning agent has the structure as follows:

wherein a/b/c/d/e/f/g/h are integers, the structure is only an organosilicon branched chain of a first-stage branched chain, two-stage or even more than two-stage organosilicon branched chains can exist at the same time, namely, the given schematic structural formula only contains one branched chain monomer, but the actual structure can contain a plurality of branched chain monomers.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects:

(1) during the preparation process of the branched amino silicone oil, octamethylcyclotetrasiloxane, branched silane and aminosilane are reacted, so that the formed silicone oil forms a product with a dendritic structure, and the aminosilane is uniformly distributed in the product; after a certain period of reaction time, reactive silanes are added for blocking and introducing double bonds. Therefore, the active unsaturated double bond appears at the tail end of the organic silicon molecular chain, so that the organic silicon branched chain can be well formed during the subsequent copolymerization with the acrylic monomer.

(2) In the third step, when the modified branched amino silicone oil and the acrylate monomer are subjected to copolymerization reaction by adopting an oxidation-reduction initiation system to prepare a product, double bonds in the modified branched amino silicone oil are activated, and then an acrylic monomer mixed solution and the rest of the initiator are slowly added by adopting a starvation-like copolymerization method, so that low-activity quaternized active organic silicon can be grafted to an acrylic resin chain better. Meanwhile, when the modified branched aminosilicone oil is dispersed by water, the molecular structure of the modified branched aminosilicone oil contains enough quaternary ammonium salt, so that the modified branched aminosilicone oil is easy to disperse to form stable dispersion liquid, and is beneficial to copolymerization reaction with acrylic monomers.

(3) In the whole process of preparing the amphoteric organic silicon modified acrylic resin retanning agent, toxic and harmful substances such as formaldehyde and the like are not used, so that the product does not have the risk of exceeding the standard of formaldehyde.

(4) The obtained amphoteric organic silicon modified acrylic resin retanning agent has the performance advantages of organic silicon and acrylic resin materials, has a good selective filling effect, can be well filled in the loose part of a leather structure, keeps the natural grain surface of the leather, has a smooth feeling when being touched, and is soft and full in body and bone, and good in leather grinding performance. Meanwhile, on the molecular chain of the amphoteric organic silicon modified acrylic resin, not only a carboxyl group with anions but also a quaternary ammonium salt with cations exist, so that the color losing problem of the acrylic resin retanning agent is fundamentally solved.

(5) The quaternary ammonium branched organosilicon branched chain is copolymerized to acrylic resin through unsaturated double bonds on the molecular chain, so that no phase separation is caused, and the product has good stability and high quality.

Detailed Description

The amphoteric organic silicon modified acrylic resin retanning agent and the preparation method thereof provided by the invention are further described in detail by combining specific examples. The advantages and features of the present invention will become more apparent from the following description.

The acrylic resin retanning agent is easy to make leather boards hard and leather fibers crisp in the tanning process, and particularly solves the problem of color loss, which always troubles the broad tanning enterprises. Therefore, efforts have been made to modify acrylic resin retanning agents with other types of polymers to address the deficiencies in the performance of such products. The organosilicon material has a unique structure, combines the performances of inorganic materials and organic materials, has the basic properties of low surface tension, small viscosity-temperature coefficient, high compressibility, high gas permeability and the like, has the excellent characteristics of high and low temperature resistance, electrical insulation, oxidation resistance stability, weather resistance, flame retardancy, hydrophobicity, corrosion resistance, no toxicity, no odor, physiological inertia and the like, and is widely applied to the industries of textile, light industry and the like.

Therefore, the invention provides an amphoteric organic silicon modified acrylic resin retanning agent, which can solve the problem of color bailing of the acrylic resin retanning agent.

One structure of the amphoteric organic silicon modified acrylic resin retanning agent is as follows:

wherein a/b/c/d/e/f/g/h are integers, the structure only shows the organosilicon branched chain of a first-stage branched chain, two-stage or even more than two-stage organosilicon branched chains can exist at the same time, namely, the shown structural formula only contains one branched chain monomer, but the actual structure can contain a plurality of branched chain monomers.

A preparation method of an amphiprotic organic silicon modified acrylic resin retanning agent comprises the following steps:

(1) preparation of branched amino silicone oil

The raw materials and the weight percentage content are as follows:

according to the percentage content of the raw materials, octamethylcyclotetrasiloxane, branched-chain silane, aminosilane, 1/2 catalyst and deionized water are added into a first reaction container, and after reaction for 1-2 hours at the temperature of 100-110 ℃, active silane and the rest catalyst are slowly added, the reaction is continued for 3-5 hours, and the obtained viscous liquid is branched amino silicone oil, and then the branched amino silicone oil is cooled to the room temperature and discharged; wherein the molar ratio of the deionized water to the octamethylcyclotetrasiloxane is 1: 1;

(2) preparation of modified branched amino silicone oil

Adding epoxy chloropropane and ethanol in a preset ratio into a second reaction container, uniformly stirring, heating to 50-70 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4-5 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain modified branched amino silicone oil; wherein the mass ratio of the epichlorohydrin to the branched amino silicone oil is 1: 0.8-1.2;

(3) preparation of amphoteric organic silicon modified acrylic resin retanning agent

Adding deionized water into the modified branched amino silicone oil obtained in the step (2), fully dispersing, heating to 55-80 ℃ under the protection of inert gas, adding 1/5 initiator, activating for half an hour, then respectively dropwise adding acrylic monomers and the rest of initiator, and continuing to react for 1-3 hours after completing dropwise addition to obtain the amphoteric organic silicon modified acrylic resin retanning agent; wherein the weight ratio of the acrylate monomer to the modified branched amino silicone oil is 1:0.1-0.5, and the mass of the initiator is 0.1-0.8% of the mass of the acrylate monomer.

Optionally, the reactive silane is at least one of vinyl dimethylethoxysilane, methacryloxypropyl dimethylmethoxysilane, methacryloxypropyl dimethylethoxysilane.

Optionally, the aminosilane is N- β - (aminoethyl) - γ -aminopropylmethyldimethoxysilane.

Optionally, the branched silane is CH₃(CH₂)_nSi(OCH₃)₃Or CH₃(CH₂)_nSi(O CH₂CH₃)₃At least one ofWherein n is an integer of 0 to 3.

Optionally, the catalyst is potassium hydroxide.

Optionally, the acrylate monomer is a mixture of acrylic acid, methacrylic acid and acrylamide, wherein the mass ratio of the acrylic acid to the methacrylic acid to the acrylamide is 50-60:20-30: 10-20.

Optionally, the initiator is a mixture of ammonium persulfate and urea or a mixture of ammonium persulfate and sodium sulfite, and the mass ratio of the ammonium persulfate to the urea or the sodium sulfite is 1: 1-6.

The invention is illustrated by the following specific examples

Example 1

(1) 63.78g of octamethylcyclotetrasiloxane, 1.59g of methyltriethoxysilane, 23.92g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and 4.34g of deionized water are added into a reaction vessel, after 2 hours of reaction at the temperature of 100 ℃, 6.38g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide are slowly added, the reaction is continued for 4 hours, and the obtained viscous liquid is the synthesized branched aminosilicone, then the branched aminosilicone is cooled to the room temperature, and the materials are discharged.

(2) Adding 100g of epoxy chloropropane and 100mL of 95% ethanol into a reaction container, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 56.0g of acrylic acid, 24.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. And (3) adding 20.0mL of the prepared modified branched aminosilicone oil dispersion liquid into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the acrylic monomer mixed liquid and the rest of the initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 2

(1) Adding 72.2g of octamethylcyclotetrasiloxane, 1.28g of methyltriethoxysilane, 16.04g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and 4.38g of deionized water into a reaction container, reacting at 100 ℃ for 2 hours, then slowly adding 5.62g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide, continuing to react for 4 hours to obtain viscous liquid, namely the synthesized branched aminosilicone, cooling to room temperature, and discharging.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 50.0g of acrylic acid, 30.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. Adding 35.0mL of the prepared modified branched amino-silicone oil dispersion into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed solution and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 3

63.78g of octamethylcyclotetrasiloxane, 1.59g of methyltriethoxysilane, 23.92g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and 4.38g of deionized water are added into a reaction vessel, after 2 hours of reaction at the temperature of 100 ℃, 6.38g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide are slowly added, the reaction is continued for 4 hours, and the obtained viscous liquid is the synthesized branched aminosilicone, then the branched aminosilicone is cooled to the room temperature, and the materials are discharged.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 36.0g of acrylic acid, 44.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. Adding 55.0mL of the prepared modified branched amino-silicone oil dispersion into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed solution and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 4

(1) Adding 72.2g of octamethylcyclotetrasiloxane, 1.28g of methyltriethoxysilane, 16.04g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and 4.38g of deionized water into a reaction container, reacting at 100 ℃ for 2 hours, then slowly adding 5.62g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide, continuing to react for 4 hours to obtain viscous liquid, namely the synthesized branched aminosilicone, cooling to room temperature, and discharging.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 40.0g of acrylic acid, 40.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. Adding 65.0mL of the prepared modified branched amino-silicone oil dispersion into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed solution and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 5

(1) 63.78g of octamethylcyclotetrasiloxane, 1.59g of methyltriethoxysilane, 23.92g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and g of deionized water are added into a reaction vessel, after 2 hours of reaction at the temperature of 100 ℃, 6.38g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide are slowly added, the reaction is continued for 4 hours, viscous liquid which is the synthesized branched aminosilicone is obtained, and then the branched aminosilicone is cooled to the room temperature and discharged.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 46.0g of acrylic acid, 34.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution;

and (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. Adding 60.0mL of the prepared modified branched amino-silicone oil dispersion into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed solution and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 6

(1) Adding 72.2g of octamethylcyclotetrasiloxane, 1.28g of methyltriethoxysilane, 16.04g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and 4.38g of deionized water into a reaction container, reacting at 100 ℃ for 2 hours, then slowly adding 5.62g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide, continuing to react for 4 hours to obtain viscous liquid, namely the synthesized branched aminosilicone, cooling to room temperature, and discharging.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 50.0g of acrylic acid, 30.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. Adding 30.0mL of the prepared modified branched amino-silicone oil dispersion into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed solution and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 7

62.78g of octamethylcyclotetrasiloxane, 1.59g of methyltriethoxysilane, 24.82g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and g of deionized water are added into a reaction vessel, after 2 hours of reaction at the temperature of 100 ℃, 6.38g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide are slowly added, the reaction is continued for 4 hours, viscous liquid is obtained, namely the synthesized branched aminosilicone, then the branched aminosilicone is cooled to the room temperature, and the materials are discharged.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction container, stirring, heating to 30 ℃, adding 46.0g of acrylic acid, 34.0g of methacrylic acid and 20.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. Adding 80.0mL of the prepared modified branched amino-silicone oil dispersion into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed solution and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Example 8

(1) Adding 70.2g of octamethylcyclotetrasiloxane, 1.08g of methyltriethoxysilane, 18.04g of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 0.48g of potassium hydroxide and 4.28g of deionized water into a reaction container, reacting for 2 hours at the temperature of 100 ℃, then slowly adding 5.82g of vinyl dimethylethoxysilane and 0.48g of potassium hydroxide, continuing to react for 4 hours to obtain viscous liquid, namely the synthesized branched aminosilicone, cooling to room temperature, and discharging.

(2) Adding 100g of epichlorohydrin and 100mL of 95% ethanol into a reaction vessel, uniformly stirring, heating to 60 ℃, dropwise adding the branched amino silicone oil while stirring, reacting for 4 hours, heating to 80 ℃, continuing to react for 1 hour, and distilling under reduced pressure to obtain the modified branched amino silicone oil.

(3) Respectively preparing 3% aqueous solution of ammonium persulfate and sodium bisulfite, and mixing the two aqueous solutions according to equal weight ratio to obtain 12.0mL initiator solution; adding 200.0mL of deionized water into a reaction vessel, stirring, heating to 30 ℃, adding 56.0g of acrylic acid, 34.0g of methacrylic acid and 10.0g of acrylamide in a dropwise manner, and stirring for half an hour to obtain an acrylic monomer mixed solution.

And (3) regulating the pH value of the modified branched amino silicone oil to 6 by using hydrochloric acid, slowly adding 150.0mL of deionized water under stirring, adding water, and continuing stirring until the mixture is in a fully dispersed state to obtain the modified branched amino silicone oil dispersion liquid. And adding 10.0mL of the prepared modified branched aminosilicone oil dispersion liquid into another reaction vessel, introducing nitrogen to remove oxygen, heating to 65 ℃, adding 1/5 initiator solution, activating for half an hour, then respectively dropwise adding the rest acrylic monomer mixed liquid and the rest initiator, and after dropwise adding for 3 hours, continuing to react for 2 hours to obtain the amphoteric polyurethane modified acrylic resin retanning agent.

Unless otherwise specified, the reaction vessel in the above examples refers to a reaction vessel used after washing and left empty, and does not refer to a reaction vessel in the previous step or in which a liquid is present.

Firstly, 8 sheepskin chrome tanned leather Nos. 1-8 are placed in 8 rotary drums, 35 ℃ water accounting for 200% of the mass of a leather sample is respectively added, sodium bicarbonate accounting for 0.8% of the mass of the leather sample is added, and the rotary drum is rotated for 20min to enable the pH value of the bath solution in the rotary drum to reach 5.5-6.0; then respectively adding water with the temperature of 35 ℃ and the mass of the leather sample being 300 percent, washing for 10min, respectively adding water with the temperature of 55 ℃ and the mass of the amphoteric organic silicon modified acrylic resin retanning agent obtained in the examples 1-8 and the mass of the leather sample being 150 percent and the mass of the amphoteric organic silicon modified acrylic resin retanning agent obtained in the examples 1-8 into 8 rotating drums, respectively adding formic acid with the mass of 0.5 percent and the mass of the leather sample after rotating for 90min, respectively adding formic acid with the mass of 0.5 percent and the mass of the leather sample after rotating for 15min, respectively adding formic acid with the mass of 0.5 percent and the mass of the leather sample after rotating for 30min, adjusting the pH value of bath liquid in the rotating drums to be 3.5-3.6, washing out of the drums and drying; finally, the thickness and tensile strength of the obtained 8 sheepskin chrome tanned leather samples No. 1-8 are detected, and the experimental results are shown in the following table:

note: the appearance is tested by the tester; the leather expansion strength is according to QB/T3812.5-1999 standard; the content of free formaldehyde is in accordance with the HJ601-2011 standard; the thickening rate is according to QB/T2709-2005 standard; the shrinkage temperature was in accordance with QB/T2713-2005.

Therefore, the amphoteric organic silicon modified acrylic resin retanning agent prepared by the method is stable, formaldehyde is not involved in the preparation method provided by the invention, the retanning agent prepared by the method can keep various original performances of chrome tanned leather, and the product has a good selective filling effect, can be well filled in a part with a loose leather structure, and is soft, plump, elastic and good in hand feeling; the edges and the abdomens cannot be loosened, the leather can be tanned alone or by being matched with other tanned agents, and the tanned product has the advantages of good leather grinding performance, no color fading of dyes and the like.

In light of the above teachings, those skilled in the art will readily appreciate that the materials and their equivalents, the processes and their equivalents, and the upper and lower limits and ranges of the parameters of the materials and processes, all of which are listed or exemplified in the present disclosure, can be used to practice the present disclosure, and the examples are not intended to be exhaustive.

The embodiments of the present invention have been described in detail with reference to the examples, but the present invention is not limited to the embodiments. Even if various changes are made to the present invention, it is still within the scope of the present invention if they fall within the scope of the claims of the present invention and their equivalents.