CN111848868B

CN111848868B - Copolymer and preparation method and application thereof

Info

Publication number: CN111848868B
Application number: CN202010684815.1A
Authority: CN
Inventors: 颜邦民; 岳中宇; 向英; 李金锜; 黄若峰; 王剑宇; 兰剑平; 王娟; 张丹
Original assignee: Chongqing Chemical Research Institute Co ltd
Current assignee: Chongqing Chemical Research Institute Co ltd
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2022-05-13
Anticipated expiration: 2040-07-16
Also published as: CN111848868A

Abstract

The invention provides a copolymer obtained by polymerizing monomers of vinyl pyrrolidone, vinyl imidazole and vinyl oxazolidone, which can exert excellent dye migration resistance effect in the presence of a surfactant, especially in the presence of an anionic surfactant, in a specific polymerization degree range, and has a small addition amount. The invention also provides a polymerization method of the copolymer, which has simple preparation process and mild reaction conditions and is suitable for large-scale industrial production.

Description

Copolymer and preparation method and application thereof

Technical Field

The invention relates to the field of chemical industry, and particularly relates to a copolymer and a preparation method and application thereof.

Background

In laundry detergents, dye transfer inhibitors are often added to avoid cross-staining when laundry is shuffled.

Currently, dye transfer inhibitors commonly added to laundry detergents are typically polymers comprising, in copolymerized form, monomers having a nitrogen heterocyclic group. Polymers such as polyvinylpyrrolidone and polyvinyllactam have various properties due to their cyclic lactam structures, and are attracting attention as useful industrial products, and are now essential as dye transfer inhibitors. Vinylimidazole-vinylpyrrolidone copolymers (PVPVI) are very effective in eliminating transfer of dissolved or suspended dyes while enhancing the performance of detergent compositions formulated therewith.

However, a surfactant is usually added to a laundry detergent, and an anionic surfactant is widely used. In this case, since the vinylimidazole-vinylpyrrolidone copolymer interacts with the surfactant, the complexing or adsorbing ability to the dye is impaired, and particularly in the case of an anionic surfactant, the vinylimidazole-vinylpyrrolidone copolymer interacts with the surfactant to coagulate, thereby causing a problem that the anti-dye transfer agent effect is hindered.

Therefore, it is an urgent problem to be solved by those skilled in the art to develop a dye transfer inhibitor that can sufficiently exhibit the property of inhibiting dye transfer even in the presence of a surfactant to overcome the disadvantages of the vinylimidazole/vinylpyrrolidone (pvpvpvi) copolymer.

Disclosure of Invention

One of the objects of the present invention is to provide a copolymer which can exert an excellent anti-migration effect in the presence of a surfactant, particularly in the presence of an anionic surfactant, and which is added in a small amount of about 20% of the amount of a conventional dye transfer inhibitor, in view of the disadvantages of the prior art.

The invention also aims to provide the preparation method of the copolymer, which has simple preparation process and mild reaction conditions and is suitable for large-scale industrial production.

The technical scheme for realizing one purpose of the invention is as follows: a copolymer has a structural formula shown as follows,

wherein, X is 10-3000, y is 10-2500, and z is 1-300.

Preferably, 150. ltoreq. x < 250, 170. ltoreq. y < 300, 15. ltoreq. z < 300, preferably, 150. ltoreq. x < 250, 170. ltoreq. y < 300, 15. ltoreq. z < 50.

Preferably, the molecular weight of the polymer is 2000-.

The second technical means for achieving the object of the present invention is a method for preparing the copolymer, comprising the steps of,

1) taking vinyl pyrrolidone, vinyl imidazole and vinyl oxazolidone as monomers for later use;

2) under the conditions of protective atmosphere and stirring, adding a certain amount of vinyl pyrrolidone, all vinyl imidazole and all vinyl oxazolidone into a reactor, adding water, and adjusting the pH to 7-9;

3) adding an initiator into the reactor in the step 2) at the temperature of 68 +/-2 ℃ for prepolymerization;

4) and 3) after the prepolymerization is finished, continuously adding an initiator, simultaneously dropwise adding the rest vinyl pyrrolidone, and keeping the temperature to be not more than 75 ℃ to obtain the aqueous solution containing the copolymer.

The mol ratio of the vinyl pyrrolidone, the vinyl imidazole and the vinyl oxazolidinone in the step 1) is 10-20: 30-60: 2-30, preferably 10-16: 40-50: 2-10.

And 2) adjusting the pH value by adopting ammonia water with the concentration of 25-28wt%, wherein the water is purified water, the addition amount of the water is 60-70% of the volume of the mixture in the reactor, and the addition amount of the vinyl pyrrolidone in the step 2) is 55-70% of the total amount of the vinyl pyrrolidone.

The initiator used in the step 3) and the step 4) is a mixture of hydrogen peroxide and ferric chloride, a mixture of hydrogen peroxide and ferrous chloride, a mixture of hydrogen peroxide and copper sulfate, a mixture of ammonium persulfate and sodium sulfite, tert-butyl hydroperoxide, azobisisobutyronitrile, azobisisobutyramidine hydrochloride, azobisisoheptonitrile and dimethyl azobisisobutyrate, preferably a mixture of hydrogen peroxide and copper sulfate, wherein the amount of the hydrogen peroxide is 0.01-3%, preferably 1-2.5% of the total mass of the monomer in the step 1), and the amount of the copper sulfate is 0.0001-0.05%, preferably 0.001-0.01% of the total mass of the monomer in the step 1).

And 4) after the reaction is finished, adding an azo initiator for removing residual monomers, wherein the azo initiator is azobisisobutyronitrile, azobisisoheptonitrile, azobisisobutyramidine hydrochloride and dimethyl azobisisobutyrate, and preferably azobisisobutyramidine hydrochloride.

In addition, the invention also claims the application of the copolymer in preparing dye transfer inhibitor.

Preferably, the dye transfer inhibitor further comprises copper sulfate, and the mass of the copper sulfate is 0.0001-0.05% of that of the copolymer, and is preferably 0.001-0.01%.

Adopt above-mentioned technical scheme to have following beneficial effect:

1. the copolymer of the invention utilizes the vinyl oxazolidone of the high-reactivity diluent to copolymerize with the vinyl pyrrolidone/vinyl imidazole structure, the obtained copolymer has better dispersion performance, and under the condition of the existence of the anionic surfactant, the complexing and adsorption capacity to the dye is greatly improved, so that the dye is dispersed to exert the effect of preventing the dye from transferring. In addition, the copolymer of the invention meets the requirement of environmental protection.

2. The copolymer has strong complexing and adsorption capacity on dye molecules, lone electrons provided by N atoms and O atoms in the copolymer are coordinated with atoms in the dye molecules to form a coordination compound, and the left C-H long chain fully extends to the periphery in a solution system and serves as an anchoring part to disperse the dye, so that the effect of preventing the dye from dyeing other fabrics is exerted. In addition, vinyl oxazolidinone is introduced through copolymerization, an O atom with a lone electron pair is carried on an oxazolidinone ring besides a strong polar lactam structure, and forms a hydrogen bond with a hydroxyl group, a carboxyl group, an amino group and other groups in a dye molecule, so that the affinity to the dye is greatly enhanced, the dye molecule in a dissolved solution system can be preferentially adsorbed even in the presence of a surfactant, and the technical effects of low copolymer consumption and strong dye adsorption capacity are achieved.

3. In the copolymer, the degree of polymerization X in the copolymer is controlled to be 10-3000, preferably 150-250, the degree of polymerization Y is 10-2500, preferably 170-300, and the degree of polymerization Z is 1-300, preferably 15-300, so that the dispersibility and the dye transfer resistance of the polymer in a solution system can be effectively ensured, if the degree of polymerization is too small, although the dispersibility of the copolymer is better, the dye transfer resistance of the copolymer is poorer, and if the degree of polymerization is too large, not only the dispersibility of the copolymer is poorer, but also the dye transfer resistance of the copolymer is poorer, and even the dye transfer resistance is not achieved.

4. According to the preparation method, after the monomers are added into the reactor, a certain proportion of water is added for solution polymerization, so that the heat dissipation is easy, and the reaction is easy to control. And adjusting the pH to 7-9 for preventing the vinylpyrrolidone from hydrolyzing under acidic conditions of pH lower than 7, and if the pH is higher than 9, the polymerization rate is slowly slowed down so that the polymerization is almost stopped after the pH is higher than 13. The reaction is carried out in an inert atmosphere, and the aim is to avoid the polymerization inhibition effect of oxygen in the air on a polymerization system, which causes the reduction of initiation efficiency. When the initiator is added for the first time for prepolymerization, part of vinyl pyrrolidone is added, on one hand, the vinyl monomer is not easy to initiate polymerization under low concentration, on the other hand, the initiator is added for the second time for preventing the problem that only vinyl oxazolidinone and vinyl imidazole in a system are polymerized to enter a chain segment to cause uneven polymer distribution, and on the other hand, the rest of vinyl pyrrolidone is added. By controlling the temperature of the system to be not more than 75 ℃, on one hand, the problem that the temperature is too high, the half-life period of the initiator is small, the polymerization period is short, and the monomer with higher activity is easy to homopolymerize to cause uneven distribution of the copolymer is solved, and on the other hand, the half-life period of the initiator is short, the monomer is dropwise added and fixed, and the residual monomer cannot be initiated in time to cause increase of the content of the residual monomer.

5. The initiator added in the preparation method is preferably a compound of hydrogen peroxide and copper sulfate, on one hand, a small amount of copper sulfate is introduced to be complexed with dye anions to generate an insoluble substance, the elution rate of the dye on a fabric is reduced, and the dye plays a role of a color fixing agent, on the other hand, copper ions in the copper sulfate have a catalytic effect on the hydrogen peroxide (the initiator), and in a certain range, the activity of the initiator is increased along with the increase of the dosage of the copper sulfate, so that the hydrogen peroxide is catalyzed to generate a large amount of hydroxyl radicals, the molecular weight of the copolymer is reduced, and the dispersibility of the copolymer in a solution system and the dye transfer resistance effect are ensured.

6. According to the preparation method disclosed by the invention, the azo initiator is added to eliminate the residual monomer, so that the highest residual monomer in a reaction system is not more than 50ppm, and the influence on the performance of the copolymer caused by the overhigh residual monomer content is avoided.

The applicant tests and verifies that compared with the traditional vinyl imidazole-vinyl pyrrolidone copolymer, the dosage of the copolymer provided by the invention is only about 20% of that of the traditional copolymer under the condition of realizing the same dye transfer resistance effect; under the condition of the existence of the anionic surfactant, the same dye transfer resistant effect is realized, the dosage of the traditional vinyl imidazole-vinyl pyrrolidone copolymer needs to be greatly increased, and the dosage of the copolymer of the invention does not need to be adjusted.

The following further description is made with reference to the accompanying drawings and detailed description.

Drawings

FIG. 1 is a statistical chart of the difference in chroma in a control test of the present invention.

Detailed Description

In the present invention, the raw materials used are shown in the following table:

example one

Replacing nitrogen in a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 by using ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 0.5g of AIBN, and carrying out prepolymerization for about 50 min; and (3) continuously heating to 72 ℃, adding 2g of AIBN, simultaneously dropwise adding 30.0116g (0.2694mol) of the rest vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, and eliminating residues once every 1h to finally obtain a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, and the content of NVP (N-vinyl pyrrolidone) in the solution is 8.86ppm, VI (VI) is 22.62ppm, and NVO (N-vinyl pyrrolidone) is 48.48 ppm. The molecular weight of the resulting copolymer was determined to be 680346.

Example two

Replacing nitrogen in a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 by using ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 0.5g of AIBN, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 3g of AIBN, simultaneously dropwise adding 30.0116g (0.2694mol) of the rest vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, and eliminating residues once every 1h to finally obtain a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, and the residual single contents of NVP, VI and NVO in the solution are 9.46ppm, 21.57ppm and 49.51 ppm. The molecular weight of the resulting copolymer was determined to be 486120.

EXAMPLE III

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding V500.5g, and carrying out prepolymerization for about 50 min; and (3) continuously heating to 72 ℃, adding V503 g, simultaneously dropwise adding 30.0116g (0.2694mol) of the rest vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, and eliminating residues once every 1h to finally obtain a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, and the residual single contents of NVP (N-vinyl pyrrolidone) in the solution are 8.51ppm, VI (VI) is 24.62ppm and NVO (N-vinyl pyrrolidone) is 49.48 ppm. The molecular weight of the resulting copolymer was determined to be 302671.

Example four

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 4.29g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, eliminating the residue once every 1h, and finally obtaining a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 9.36ppm, the VI in the solution is 21.92ppm, and the NVO in the solution is 48.98 ppm. The molecular weight of the resulting copolymer was determined to be 70236.

EXAMPLE five

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 5.71g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, after dropwise adding for about 1.5h, subsequently preserving heat for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, removing residues for three times, removing residues once every 1h, and finally obtaining a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 7.47ppm, the VI is 21.57ppm and the NVO is 48.97 ppm. The molecular weight of the copolymer obtained was 60023.

EXAMPLE six

Adding 200g of purified water into a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adjusting the pH to 7-9 by using ammonia water, starting stirring, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO) when the temperature is raised to 45 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g when the temperature is raised to 68 ℃, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 7.14g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, after dropwise adding for about 1.5h, subsequently preserving heat for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, and eliminating the residue once every 1h to finally obtain a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 7.73ppm, the VI in the solution is 24.73ppm, and the NVO in the solution is 47.89 ppm. The molecular weight of the copolymer obtained was determined to be 50035.

EXAMPLE seven

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 8.57g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, eliminating the residue once every 1h, and finally obtaining a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 8.67ppm, the VI in the solution is 23.87ppm, and the NVO in the solution is 49.67 ppm. The molecular weight of the copolymer was 40037.

Example eight

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 10.00g (0.0885mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 10.00g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, eliminating the residue once every 1h, and finally obtaining a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 9.58ppm, the VI in the solution is 24.65ppm, and the NVO in the solution is 47.91 ppm. The molecular weight of the resulting copolymer was determined to be 36825.

Example nine

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 6.00g (0.0531mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 7.14g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, eliminating the residue once every 1h, and finally obtaining a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 8.97ppm, the VI in the solution is 23.79ppm, and the NVO in the solution is 48.88 ppm. The molecular weight of the obtained copolymer was determined to be 49024.

Example ten

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 5.00g (0.0442mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 7.14g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g g, simultaneously dropwise adding 30.0116g (0.2694mol) of the remaining vinylpyrrolidone, after finishing dropwise adding for about 1.5h, subsequently preserving heat for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine salt hydrochloride, carrying out three-time residue elimination, and eliminating residues once every 1h to finally obtain a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content NVP in the solution is 9.46ppm, the VI is 22.47ppm, and the NVO is 48.87 ppm. . The molecular weight of the obtained copolymer was 48502.

EXAMPLE eleven

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 4.00g (0.0354mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 7.14g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, after dropwise adding for about 1.5h, subsequently preserving heat for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, and eliminating the residue once every 1h to finally obtain a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 9.17ppm, the VI in the solution is 23.62ppm, and the NVO in the solution is 47.99 ppm. The molecular weight of the resulting copolymer was determined to be 48314.

Example twelve

Replacing nitrogen with a four-neck flask with mechanical stirring, constant-pressure dropping and a funnel thermometer, adding 200g of purified water, adjusting the pH to 7-9 with ammonia water, starting stirring, heating to 45 ℃, adding 14.9884g (0.1349mol) of vinyl pyrrolidone (NVP), 45.00g (0.4782mol) of Vinyl Imidazole (VI) and 3.00g (0.0265mol) of vinyl oxazolidone (NVO), heating to 68 ℃, adding 1.43g of 35 wt% hydrogen peroxide and 0.01 wt% copper sulfate solution 0.5g, and carrying out prepolymerization for about 50 min; and continuously heating to 72 ℃, adding 7.14g of 35 wt% of hydrogen peroxide and 0.01 wt% of copper sulfate solution 0.5g, simultaneously dropwise adding the remaining 30.0116g (0.2694mol) of vinyl pyrrolidone, finishing dropwise adding for about 1.5h, then keeping the temperature for 3h, heating to 75 ℃, adding 0.3g of azodiisobutyramidine hydrochloride, carrying out three-time residue elimination, eliminating the residue once every 1h, and finally obtaining a copolymer with the concentration of about 30 wt%, wherein the solution is faint yellow, the residual single content of NVP in the solution is 8.87ppm, the VI in the solution is 23.57ppm, and the NVO in the solution is 47.79 ppm. The molecular weight of the resulting copolymer was found to be 47412.

Control test

(1) Instrument for measuring the position of a moving object

The specification of a beaker A, a beaker B and a beaker C is 200 ml; three 15cm glass rods; white pure cotton knitted fabric, 10cm by 6cm, a plurality of; the colotqutxese colorimeter, a liquid taking gun (0-100 mu L), a timer (only a watch), small scissors and tweezers.

(2) Reagent

Direct dyes (straight red and straight blue) are prepared into a solution with the concentration of 100g and 0.005 g/ml;

dye transfer inhibitor PVP-VI copolymer, commercially available product; a product prepared in example ten of the present invention; linear sodium silyl sulfonate (anionic surfactant), analytically pure; 1000ml of purified water.

(3) Solution preparation

Weighing 0.5g of red dye into a beaker for dissolving, transferring the red dye into a 100ml volumetric flask, fixing the volume to 100ml, and shaking up to obtain 100g of dye solution with the concentration of 0.005g/ml for later use.

Taking 2g (pure) of PVP-VI copolymer to a 100ml volumetric flask, adding water to a constant volume, and shaking up to obtain a control solution with the concentration of 0.02 g/ml; 2g (pure) of the product prepared in example ten is taken into a 100ml volumetric flask, added with water to a constant volume and shaken up to obtain a test solution with a concentration of 0.02 g/ml.

(4) Dyeing test

Adding 200ml of purified water into a beaker A, a beaker B and a beaker C respectively;

adding 5ml of dye solution and 0.1g of linear sodium silicon sulfonate into the beaker A, the beaker B and the beaker C respectively, and measuring the chroma of the white pure cotton knitted fabric by using a chroma meter respectively and recording the chroma as EO;

respectively adding 50 mu L of control solution and test solution into the beaker B and the beaker C, taking the beaker A as a blank control, and sequentially verifying that the addition amount of the dye transfer inhibitor is 50 mu L, 100 mu L, 150 mu L and 200 mu L … … 1200 mu L to totally 20 groups of test comparisons;

fourthly, after stirring evenly for 2min, respectively putting a piece of white pure cotton knitted fabric into the beaker A, the beaker B and the beaker C, and continuing stirring for 5 min;

pouring off the aqueous solution after about 5min, taking out the colored cloth, putting the colored cloth into a beaker A, a beaker B and a beaker C, adding 200ml of purified water respectively, stirring, taking out the corresponding cotton cloth, and squeezing to dry;

sixthly, flattening three pieces of cotton cloth, and measuring the chroma by using a chroma meter respectively and marking as E1;

and (c) calculating the chromaticity difference delta E of the corresponding dye transfer agent as E1-E0, and drawing a statistical graph of the chromaticity difference delta E and the dye dosage of the corresponding dye inhibitor dosage. As shown in fig. 1.

As can be seen from fig. 1, with the increase of the amount of the dye transfer agent, in the anti-cross-color test performed by using the PVP-VI type dye inhibitor, the color difference of the white cloth is reduced slowly and then reduced rapidly, which indicates that when the amount of the dye inhibitor is small, the dye inhibitor interacts with the anionic surfactant in the solution preferentially, so that the adsorption capacity of the dye inhibitor to the dye is reduced seriously, and the anti-dye transfer effect is weak; when the dye inhibitor reaches a certain dosage, the excessive dye inhibitor starts to obviously show the effect of preventing the dye transfer; in the anti-cross color test carried out by the copolymer (NVP-VI-NVO), the color difference of white cloth is rapidly reduced along with the increase of the using amount of the dye transfer agent, which shows that the addition of the dye inhibitor is not restricted by the addition of the anionic surfactant, and the superior performance of preventing dye transfer can be fully exerted even at low dose.

Claims

1. A preparation method of a copolymer is characterized in that the structural formula of the copolymer is shown as follows,

wherein X is 10-3000, y is 10-2500, z is 1-300,

the preparation method comprises the following steps:

2) under the conditions of protective atmosphere and stirring, adding vinyl pyrrolidone accounting for 55-70% of the total amount of the vinyl pyrrolidone, all vinyl imidazole and all vinyl oxazolidone into a reactor, adding water, and adjusting the pH value to 7-9;

4) step 3), after the prepolymerization is finished, continuously adding an initiator, simultaneously dropwise adding the rest vinyl pyrrolidone, and keeping the temperature to be not more than 75 ℃ to obtain a copolymer-containing aqueous solution;

the initiator added in the step 3) and the step 4) is a mixture of hydrogen peroxide and copper sulfate, the dosage of the hydrogen peroxide is 0.01-3% of the total mass of the monomers in the step 1), and the dosage of the copper sulfate is 0.0001-0.05% of the total mass of the monomers in the step 1).

2. The method for producing a copolymer according to claim 1, wherein x is 150. ltoreq. x < 250, y is 170. ltoreq. y < 300, and z is 15. ltoreq. z < 300.

3. The method for producing a copolymer according to claim 2, wherein x is 150. ltoreq. x < 250, y is 170. ltoreq. y < 300, and z is 15. ltoreq. z < 50.

4. The method for preparing a copolymer as claimed in claim 1, wherein the molecular weight of the polymer is 2000-.

5. The method for preparing a copolymer as claimed in claim 4, wherein the molecular weight of the polymer is 2000-70000.

6. The method for preparing a copolymer as claimed in claim 5, wherein the molecular weight of the polymer is 3500-60000.

7. The method of producing the copolymer as claimed in claim 1, wherein the amount of hydrogen peroxide is 1 to 2.5% by mass and the amount of copper sulfate is 0.001 to 0.01% by mass based on the total mass of the monomers in the step 1).

8. The method for preparing the copolymer according to claim 1, wherein the pH adjustment in the step 2) is performed using aqueous ammonia having a concentration of 25 to 28wt%, the water is purified water, and the amount of water added is 60 to 70% by volume of the mixture in the reactor.

9. The method of producing a copolymer according to claim 1, wherein, after the completion of the reaction in the step 4), an azo initiator is added to remove the residual monomers, and the azo initiator is azobisisobutyronitrile, azobisisoheptonitrile, azobisisobutyramidine hydrochloride, or dimethyl azobisisobutyrate.

10. The method of producing a copolymer as defined in claim 9, wherein the residual monomer is eliminated by adding azobisisobutyramidine hydrochloride after the completion of the reaction in the step 4).