Synthesis method of chloride-free cationic rosin size emulsifier

Abstract

The invention provides a synthesis method of a chloride-free cationic rosin size emulsifier, which comprises the following steps: adding water to dilute dimethyl diallyl ammonium chloride, acrylamide and methacryloyloxyethyl trimethyl ammonium chloride according to a certain proportion to prepare a monomer mixed solution; the monomer mixed solution and the initiator solution are simultaneously pumped into a first microchannel reactor for polymerization reaction, the reaction temperature is 60-100 DEG C, the pressure is 0.2-1.4 Mpa, the retention time is 0.5-3 min, and a cationic polymer is obtained; and simultaneously pumping the cationic polymer and glyoxal into the second microchannel reactor for continuous reaction at the reaction temperature of 10-20 DEG C under the pressure of 2-4.0 Mpa for 0.5-3 minutes. The reaction time is greatly shortened by adopting the microchannel reactor, the method is suitable for industrial production, the synthesized chloride-free cationic rosin size emulsifier is safe, non-toxic, easy to dissolve in water, strong in cohesion, good in hydrolytic stability and free of gelling in 80 days, and rosin emulsion prepared by utilizing the cationic emulsifier is fine in granularity, good in stability and free of chloropropanol.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of rosin glue emulsifiers, in particular to a method for synthesizing a chlorine-free cationic rosin glue emulsifier. Background Art

[0002] At present, most cationic rosin glue emulsifiers are epoxy polyamide resin emulsifiers or cationic emulsifiers obtained by copolymerization of multiple monomers and cationic monomers. There are many polymerization methods for cationic rosin glue emulsifiers. The more mature synthesis methods at home and abroad are to add initiators and metal ion chelating agents under nitrogen atmosphere, initiate the copolymerization of monomers at a suitable temperature, and then react the polymerization product with glyoxal. This method is an intermittent reaction. The reaction time of the reaction materials in the reactor is long, the stirring and mixing effect is poor, the heat transfer effect is poor, the conversion rate is low, the molecular weight distribution is uneven, and the product quality is affected. In addition, the reaction control is difficult, and implosion will occur if you are not careful, which poses a safety hazard. At the same time, the polymerization product reacts with glyoxal for too short a time and the reaction is not thorough. The emulsification and emulsified product sizing effect cannot be guaranteed. If the reaction time is too long, the cross-linking will deepen and there will be partial gel, which affects the use. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for synthesizing a chlorine-free cationic rosin glue emulsifier with high conversion rate, high characteristic viscosity and low gelation, thereby overcoming the above-mentioned defects of the prior art.

[0004] The present invention is achieved by adopting the following technical solutions:

[0005] A method for synthesizing a chlorine-free cationic rosin glue emulsifier comprises the following steps:

[0006] S1, dimethyldiallylammonium chloride, acrylamide, and methacryloyloxyethyltrimethylammonium chloride are diluted with water in a certain proportion to prepare a monomer mixture;

[0007] S2, pumping the monomer mixture and the initiator solution into the first microchannel reactor through two metering delivery pumps to carry out polymerization reaction, the reaction temperature is 60-100° C., the pressure is 0.2-1.4 MPa, and the reaction residence time is 0.5-3 min;

[0008] S3, after the reaction, transferring the material to a cooling device for cooling treatment to obtain a cationic polymer with a temperature of 40-60° C.;

[0009] S4. Pumping the cationic polymer and glyoxal into the second microchannel reactor simultaneously through two metering delivery pumps to continue the reaction, the reaction temperature is 10-20° C., the pressure is 2-4.0 MPa, and the reaction residence time is 0.5-3 min to obtain the chlorine-free cationic rosin glue emulsifier.

[0010] The microstructure inside the microchannel reactor makes the reactor have a very large specific surface area, which can reach hundreds or even thousands of times the specific surface area of ​​the stirred tank, so that it has excellent heat and mass transfer capabilities, and can achieve instantaneous uniform mixing of materials and efficient heat transfer. Therefore, many reactions that cannot be achieved in conventional reactors can be achieved in microreactors. The inventor has found that a chlorine-free cationic rosin glue emulsifier is prepared by a two-step method using a microchannel reactor, that is, the first step is to mix three monomers of dimethyldiallyl ammonium chloride, acrylamide, and methacryloyloxyethyl trimethyl ammonium chloride in a microchannel reactor and initiate a free radical polymerization reaction by an initiator, and the second step is to introduce a cationic copolymer and glyoxal into a second microchannel reactor for further reaction. In addition to increasing the reaction rate and conversion rate, the characteristic viscosity of the product is unexpectedly greatly increased, and the gel time of the product is greatly extended, thereby obtaining a higher quality cationic rosin glue emulsifier. Its principle is not clear, and it is speculated that it may be due to the unique characteristics of the microchannel reactor, which makes the reaction break through the polymerization degree of the conventional reactor, and the reactivity of the free radical is higher, thereby obtaining a copolymer with a higher degree of polymerization and a higher molecular weight. In addition, the extension of gel time is also unexpected. Usually, copolymers with high characteristic viscosity, i.e., higher molecular weight, have relatively shorter gel time. However, the present invention obtains the opposite result. It is speculated that it may be because the polymerization reaction is completed in a shorter time by using a microchannel reactor. Therefore, although a copolymer with higher molecular weight is obtained, the molecular weight distribution of the copolymer is much narrower than that of a conventional reactor, thereby greatly extending the gel time of the product. Based on the above findings, the inventors have completed the present invention.

[0011] Furthermore, the amounts of the three monomers in step S1 are: 15-30 parts of dimethyldiallylammonium chloride, 8-12 parts of acrylamide, and 5-15 parts of methacryloyloxyethyltrimethylammonium chloride. The content of the monomer mixture after dilution with water is 20-50 wt% (based on the total amount of each monomer).

[0012] The initiator is selected from at least one of ammonium persulfate, potassium persulfate, hydrogen peroxide, ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydrogen peroxide / tartaric acid, hydrogen peroxide / bleaching powder, ammonium persulfate / ferrous sulfate, and hydrogen peroxide / ferrous sulfate. The mass ratio of the initiator to the monomer is 0.005-0.015:1.

[0013] In step S4, the amount of glyoxal added is 1-10% of the total amount of the three monomers, preferably 2-8%.

[0014] Furthermore, the microchannel reactor is made of silicon carbide, stainless steel or Hastelloy.

[0015] Furthermore, the liquid holding capacity of the microchannel reactor is 20-500 mL.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The synthesis method of the chlorine-free cationic rosin glue emulsifier of the present invention solves the problem that the traditional rosin glue emulsifier has a high content of chloropropanol and a poor emulsification effect. At the same time, the method replaces the traditional process conditions of kettle-type dripping. By adopting a microchannel reactor, the heat and mass transfer efficiency is extremely high, and the reaction efficiency is improved by means of the local eddy collision of the fluid in the reactor, which greatly shortens the reaction time. The reaction temperature and residence time can be accurately controlled by using a microchannel reactor, and continuous and safe production can be achieved. The microchannel reactor reduces equipment requirements, is easy to operate, saves manpower, reduces land occupation and investment, and is suitable for industrial production.

[0018] 2. The chlorine-free cationic rosin glue emulsifier of the present invention is a strong cationic polymer, which is a colorless to light yellow viscous liquid in appearance, safe, non-toxic, easily soluble in water, strong in cohesion, good in hydrolysis stability, no gelation for 80 days, insensitive to changes in pH value, with a specific gravity of about 1.04g / cm3 and a decomposition temperature of 300-360°C. Because of its strong cationicity, monomer polymers with appropriate molecular weight can be used as excellent cationic emulsifiers, with appropriate HLB values, integrating the functions of emulsification, dispersion, stabilization, retention, and improving internal bonding strength. The rosin emulsion prepared by using the cationic emulsifier has fine particle size, good stability, and does not contain chloropropanol. DETAILED DESCRIPTION

[0019] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only used as examples, but are not used to limit the scope of the present invention. Those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0020] The instruments or raw materials in the present invention without indicating the manufacturer are all conventional commercial instruments or raw materials.

[0021] Unless otherwise mentioned, the detection indicators involved in the embodiments of the present invention are detected by conventional detection methods in the art.

[0022] Example 1

[0023] A method for synthesizing a chlorine-free cationic rosin emulsifier of the present embodiment comprises the following steps:

[0024] Step 1) diluting 30 parts by weight of monomers of dimethyldiallylammonium chloride, 10 parts by weight of acrylamide, and 12 parts by weight of methacryloyloxyethyltrimethylammonium chloride with water to a content of 50%;

[0025] Step 2) The ammonium persulfate aqueous solution and the 50% monomer mixed solution are simultaneously pumped into the first microchannel reactor from the raw material storage tank by two metering delivery pumps, the mass ratio of ammonium persulfate to monomer is 0.005:1, the ammonium persulfate is diluted with water to a 5% aqueous solution, the reaction temperature is 70°C, the pressure is 0.2Mpa, and the reaction residence time is 0.5min;

[0026] Step 3) cooling the material after the reaction to obtain a polymer aqueous solution;

[0027] Step 4) The polymer aqueous solution and 40 wt% glyoxal aqueous solution (based on the absolute dry weight of ethylene glycol, the addition amount is 2 parts by weight) are pumped into the second microchannel reactor through two metering delivery pumps to continue the reaction, the reaction temperature is 10°C, the pressure is 4.0 MPa, the reaction residence time is 1 min, and the obtained material is cooled to obtain a chlorine-free cationic rosin glue emulsifier.

[0028] Among them, the material of the microchannel reactor is stainless steel, and the liquid holding capacity is 80mL.

[0029] Example 2

[0030] A method for synthesizing a chlorine-free cationic rosin emulsifier of the present embodiment comprises the following steps:

[0031] Step 1) diluting 15 parts by weight of monomers of dimethyldiallylammonium chloride, 8 parts by weight of acrylamide, and 10 parts by weight of methacryloyloxyethyltrimethylammonium chloride with water to a content of 40%;

[0032] Step 2) The potassium persulfate / sodium bisulfite aqueous solution and the 40% monomer mixed solution are simultaneously pumped into the first microchannel reactor from the raw material storage tank by two metering delivery pumps, the mass ratio of potassium persulfate / sodium bisulfite to the monomer is 0.015:1, the potassium persulfate / sodium bisulfite is diluted with water to a 5% aqueous solution, the reaction temperature is 100° C., the pressure is 0.5 MPa, and the reaction residence time is 1 min;

[0033] Step 3) cooling the material after the reaction to obtain a polymer aqueous solution;

[0034] Step 4) The polymer aqueous solution and 40 wt% glyoxal aqueous solution (based on the absolute dry weight of ethylene glycol, the addition amount is 5 parts by weight) are pumped into the second microchannel reactor through two metering delivery pumps to continue the reaction. The reaction temperature is 20° C., the pressure is 2.0 MPa, and the reaction residence time is 0.5 min. The obtained material is cooled and treated to obtain a chlorine-free cationic rosin glue emulsifier.

[0035] Among them, the material of the microchannel reactor is Hastelloy, and the liquid holding capacity is 20mL.

[0036] Example 3

[0037] A method for synthesizing a chlorine-free cationic rosin emulsifier of the present embodiment comprises the following steps:

[0038] Step 1) diluting 20 parts by weight of monomers of dimethyldiallylammonium chloride, 10 parts by weight of acrylamide, and 5 parts by weight of methacryloyloxyethyltrimethylammonium chloride with water to a content of 30%;

[0039] Step 2) Pumping potassium persulfate aqueous solution and 30% monomer mixed solution from the raw material storage tank into the first microchannel reactor simultaneously through two metering delivery pumps, the mass ratio of potassium persulfate to monomer is 0.01:1, potassium persulfate is diluted with water to a 5% aqueous solution, the reaction temperature is 90° C., the pressure is 0.8 MPa, and the reaction residence time is 2 min;

[0040] Step 3) cooling the material after the reaction to obtain a polymer aqueous solution;

[0041] Step 4) The polymer aqueous solution and 40 wt% glyoxal aqueous solution (based on the absolute dry weight of ethylene glycol, the addition amount is 3 parts by weight) are pumped into the second microchannel reactor through two metering delivery pumps to continue the reaction. The reaction temperature is 20° C., the pressure is 4.0 MPa, and the reaction residence time is 0.5 min. The obtained material is cooled to obtain a chlorine-free cationic rosin glue emulsifier.

[0042] Among them, the material of the microchannel reactor is silicon carbide, and the liquid holding capacity is 200mL.

[0043] Example 4

[0044] A method for synthesizing a chlorine-free cationic rosin emulsifier of the present embodiment comprises the following steps:

[0045] Step 1) diluting 10 parts by weight of monomers of dimethyldiallylammonium chloride, 12 parts by weight of acrylamide, and 15 parts by weight of methacryloyloxyethyltrimethylammonium chloride with water to a content of 20%;

[0046] Step 2) hydrogen peroxide and a 20% monomer mixture are pumped into the first microchannel reactor from the raw material storage tank by two metering delivery pumps, the mass ratio of hydrogen peroxide to monomer is 0.015:1, hydrogen peroxide is diluted with water to a 5% aqueous solution, the reaction temperature is 80°C, the pressure is 1.4 MPa, and the reaction residence time is 3 min;

[0047] Step 3) cooling the material after the reaction to obtain a polymer aqueous solution;

[0048] Step 4) The polymer aqueous solution and 40 wt% glyoxal aqueous solution (based on the absolute dry weight of ethylene glycol, the addition amount is 5 parts by weight) are pumped into the second microchannel reactor through two metering delivery pumps to continue the reaction. The reaction temperature is 10° C., the pressure is 4 MPa, and the reaction residence time is 3 min. The obtained material is cooled to obtain a chlorine-free cationic rosin glue emulsifier.

[0049] Among them, the material of the microchannel reactor is silicon carbide, and the liquid holding capacity is 200mL.

[0050] Comparative Example

[0051] The monomer aqueous solution is placed in a four-necked flask with a thermometer, and 0.007% EDTA (accounting for the mass of the monomer aqueous solution), an appropriate amount of ammonium persulfate (APS) solution and deionized water are added. 60 parts of dimethyldiallylammonium chloride, 30 parts of acrylamide, and 10 parts of methacryloyloxyethyltrimethylammonium chloride are adjusted. Stir evenly and pass nitrogen through the reaction system for deoxygenation for about 20 minutes. The reaction system is controlled at 40°C (feeding temperature). After the system is mixed evenly, the system is heated in stages to reach a polymerization reaction initiation temperature of 46°C, a polymerization reaction temperature of 50°C, and a polymerization reaction aging temperature of 70°C. After each stage reacts for 3 hours, it is cooled to 60°C, and an aqueous solution of glyoxal is added to react for 3 hours to obtain a cationic rosin emulsifier.

[0052] The following standards or methods are used to determine the intrinsic viscosity, monomer conversion and gel time of the polymer:

[0053] Intrinsic viscosity: Using 1 mol / L sodium chloride aqueous solution as solvent, the intrinsic viscosity η of the product was measured by using an Ubbelohde viscometer in a 30°C water bath.

[0054] Conversion rate: The monomer conversion rate was determined according to the GB20052-89 method for determining the solid content of polyacrylamide and the method for measuring the residual acrylamide in polyacrylamide.

[0055] Stability: Store at 30°C and observe the time it takes for gel to appear.

[0056] The test results are shown in Table 1.

[0057] Table 1 Sample test data

[0058] name Conversion rate / % Intrinsic viscosity η value Gel time / d Example 1 97.3 1.78 87 Example 2 98.5 1.86 92 Example 3 98.4 1.86 103 Example 4 97.7 1.77 98 Comparative Example 87.6 1.13 42

[0059] It can be seen from the test data that the preparation method of the chlorine-free cationic rosin glue emulsifier of the present invention has a high conversion rate, a characteristic viscosity better than that of the conventional method, a significantly prolonged gel time, and is simple to operate and easy to control.

[0060] It should be understood by those skilled in the art that the above embodiments are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A method for synthesizing a chlorine-free cationic rosin emulsifier, characterized in that: The steps include: S1, dimethyldiallylammonium chloride, acrylamide, and methacryloyloxyethyltrimethylammonium chloride are diluted with water in a certain proportion to prepare a monomer mixture; S2, pumping the monomer mixture and the initiator solution into the first microchannel reactor through two metering delivery pumps to carry out polymerization reaction, the reaction temperature is 60-100° C., the pressure is 0.2-1.4 MPa, and the reaction residence time is 0.5-3 min; S3, after the reaction, transferring the material to a cooling device for cooling treatment to obtain a cationic polymer with a temperature of 40-60° C.; S4. Pumping the cationic polymer and glyoxal into the second microchannel reactor simultaneously through two metering delivery pumps to continue the reaction, the reaction temperature is 10-20° C., the pressure is 2-4.0 MPa, and the reaction residence time is 0.5-3 min to obtain the chlorine-free cationic rosin glue emulsifier.

2. The method according to claim 1, characterized in that The amounts of the three monomers used in step S1 are: 15-30 parts of dimethyldiallylammonium chloride, 8-12 parts of acrylamide, and 5-15 parts of methacryloyloxyethyltrimethylammonium chloride.

3. The method according to claim 1, characterized in that The initiator is selected from at least one of ammonium persulfate, potassium persulfate, hydrogen peroxide, ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydrogen peroxide / tartaric acid, hydrogen peroxide / bleaching powder, ammonium persulfate / ferrous sulfate, and hydrogen peroxide / ferrous sulfate.

4. The method according to claim 1, characterized in that The mass ratio of initiator to monomer is 0.005-0.015:

1.

5. The method according to claim 1, characterized in that In step S4, the amount of glyoxal added is 1-10% of the total amount of the three monomers.

6. The method according to claim 1, characterized in that In step S4, the amount of glyoxal added is 2-8% of the total amount of the three monomers.

7. The method according to claim 1, characterized in that The microchannel reactor is made of silicon carbide, stainless steel or Hastelloy.

8. The method according to claim 1, characterized in that The liquid holding capacity of the microchannel reactor is 20-500 mL.

9. The method according to claim 1, characterized in that The following steps are involved: S1, diluting 20 parts by weight of dimethyldiallylammonium chloride, 10 parts by weight of acrylamide, and 5 parts by weight of methacryloyloxyethyltrimethylammonium chloride with water to a content of 30% to prepare a monomer mixture; S2, pumping the monomer mixture and potassium persulfate aqueous solution into the first microchannel reactor simultaneously through two metering delivery pumps for polymerization reaction, the mass ratio of potassium persulfate to monomer is 0.01:1, potassium persulfate is diluted with water to a 5% aqueous solution, the reaction temperature is 90° C., the pressure is 0.8 MPa, and the reaction residence time is 2 min; S3, cooling the material after the reaction to obtain a cationic polymer; S4. Pump the cationic polymer and 3 parts by weight of glyoxal into the second microchannel reactor through two metering delivery pumps to continue the reaction. The reaction temperature is 20° C., the pressure is 4.0 MPa, and the reaction residence time is 0.5 min to obtain the chlorine-free cationic rosin glue emulsifier.

10. The chlorine-free cationic rosin glue emulsifier prepared according to the method of claims 1-9.