Chlorine-free cation dispersed rosin size and preparation method thereof

Abstract

The invention provides a preparation method of chloride-free cation dispersed rosin size, which comprises the following steps: proportionally adding water into dimethyl diallyl ammonium chloride, acrylamide and methacryloyloxyethyl trimethyl ammonium chloride for diluting and uniformly mixing, slowly adding a proper amount of EDTA (Ethylene Diamine Tetraacetic Acid) and an initiator, and uniformly stirring; the system respectively reaches a polymerization reaction initiation temperature, a polymerization reaction temperature and a polymerization reaction curing temperature through segmented heating, cooling is carried out after the reaction is completed, glyoxal is added, and a cationic emulsifier is prepared through a heat preservation reaction; and introducing a cationic emulsifier into the modified rosin liquid, carrying out full pre-emulsification under the action of a mixer, then carrying out high-pressure homogenization, cooling, and adding an aluminum salt and a defoaming agent to obtain the chloride-free cationic dispersed rosin size. According to the preparation method, high-temperature and high-pressure pre-dispersion and high-pressure homogeneous emulsification processes are adopted, the self-made single cationic emulsifier is used for emulsifying the modified rosin, the chlorine-free cationic rosin size which is excellent in performance and does not contain chloropropanol is prepared, and functional auxiliaries such as a stabilizer and a dispersing agent do not need to be additionally added.

Description

Technical Field

[0001] The invention relates to the technical field of papermaking sizing agents, and in particular to a cationic dispersed rosin size and a preparation method thereof. Background Art

[0002] Sizing is an important process in papermaking. Among the numerous paper sizing agents, rosin sizing agents are dominant. The most widely used internal sizing agent in China is rosin sizing agent, accounting for more than 2 / 3 of the total sizing amount. Since the sizing rate of dispersed rosin sizing is 4 times that of ordinary rosin sizing and 2 times that of reinforced rosin sizing, it can improve the quality of paper and reduce the amount of aluminum sulfate and brightener, etc., and is a replacement product for saponified rosin sizing.

[0003] Cationic dispersed rosin size has many advantages and has always been one of the main sizing agents for paper pulp internal sizing. At present, the production process of cationic rosin size is mostly intermittent atmospheric pressure phase reversal method, which has high requirements for emulsification process conditions. The stability of the produced rosin size is slightly poor, and it is easy to undergo phase transition to form brown precipitates on the liquid surface; and the emulsifier is a single high molecular polymer, which will produce a lot of foam during use. At the same time, the content of chloropropanol in the finished product is high, and the production process of the emulsifier is cumbersome and the cost is high. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a chlorine-free cationic dispersed rosin glue and a preparation method thereof, so as to further improve the chemical stability and storage stability.

[0005] The present invention is achieved by adopting the following technical solutions:

[0006] A method for preparing a chloride-free cationic dispersed rosin glue comprises the following steps:

[0007] S1. Dimethyldiallylammonium chloride, acrylamide, and methacryloyloxyethyltrimethylammonium chloride are diluted with water in proportion and mixed evenly, and appropriate amounts of EDTA and initiator are slowly added. The system is heated in stages to reach a polymerization initiation temperature of 46-48°C, a polymerization temperature of 50-55°C, and a polymerization aging temperature of 70-75°C, respectively. Each stage reacts for 2-4 hours, then cools to 30-35°C, adds glyoxal, and reacts at this temperature for 2-4 hours to obtain a cationic emulsifier;

[0008] S2, heating and melting the rosin, adding a modifier to fully react, and obtaining a modified rosin liquid;

[0009] S3, introducing the cationic emulsifier into the modified rosin solution, and fully pre-emulsifying it under the action of a mixer;

[0010] S4, passing the pre-emulsified mixed solution into a high-pressure homogenizer for homogenization, adding aluminum salt and defoaming agent after cooling, and obtaining the chloride-free cationic dispersed rosin glue.

[0011] Preferably, the weight proportions of the components are as follows: 50-100 parts of rosin, 5-10 parts of modifier, 80-120 parts of cationic emulsifier, 10-15 parts of aluminum salt, and 0.1-0.5 parts of defoamer.

[0012] In step S1, the usage of the three monomers is: 15-30 parts of dimethyldiallylammonium chloride, 8-12 parts of acrylamide, and 5-15 parts of methacryloyloxyethyltrimethylammonium chloride.

[0013] In step S1, the amount of glyoxal added is 1-10% of the total amount of the three monomers, preferably 2-8%.

[0014] In step S1, 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 mixed monomer is 0.005-0.015:1.

[0015] Preferably, in step S1, the three monomers are diluted with water to form a 20-50wt% monomer mixture; the amount of EDTA added is 0.001-0.01wt% of the mass of the monomer mixture, preferably 0.005-0.008wt%.

[0016] The present invention adopts a staged polymerization process to prepare a cationic emulsifier, including a first stage of polymerization initiation, a second stage of polymerization, and a third stage of polymerization maturation. The initiator is slowly added when the polymerization initiation temperature of the first stage is reached, and the addition time is controlled within 2-5 hours, that is, the addition is completed at the latest before the completion of the polymerization stage of the second stage.

[0017] In step S2, the modifier is selected from at least one of succinic acid, maleic acid and maleic anhydride. Specifically, the modified rosin liquid is prepared by reacting rosin and the modifier at 180-195° C. for 1-3 hours.

[0018] The aluminum salt is selected from at least one of aluminum sulfate, polyaluminum chloride, and crystalline aluminum chloride;

[0019] The defoaming agent is selected from at least one of emulsified silicone oil, high carbon alcohol complex, polyether and polydimethylsiloxane.

[0020] Preferably, the temperature in the mixer in step S3 is controlled in the range of 150-155°C.

[0021] Preferably, in step S4, the homogenizing pressure of the homogenizer is: low pressure 8-10MPa, high pressure 25-30MPa.

[0022] The cationic dispersed rosin glue prepared by the invention has a milky white appearance, good stability, a solid content of 30-40%, a viscosity of 10-20 mPa.s, good dispersibility in cold water, good storage stability, and no stratification, no precipitation, no floating matter, and no chloropropanol when placed at room temperature for six months.

[0023] The invention adopts high temperature and high pressure pre-dispersion and high pressure homogenization emulsification process, uses a homemade single cationic emulsifier to emulsify the modified rosin, and prepares the chlorine-free cationic rosin glue with excellent performance and no chloropropanol, without the need to add additional functional additives such as stabilizers and dispersants. DETAILED DESCRIPTION

[0024] 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.

[0025] The instruments or raw materials in the present invention that do not indicate the manufacturer are all conventional commercial instruments or raw materials. If the detection indicators involved in the embodiments of the present invention are not mentioned, they are all detected by conventional detection methods in the art.

[0026] Example 1

[0027] 15 parts of dimethyldiallylammonium chloride, 8 parts of acrylamide, 5 parts of methacryloyloxyethyltrimethylammonium chloride, the content after dilution with water is 20%, add 0.007% EDTA (accounting for the mass of monomer aqueous solution) and ammonium persulfate, the mass ratio of ammonium persulfate to monomer is 0.005:1, dilute ammonium persulfate with water to a 5% aqueous solution, stir evenly and pass nitrogen through the reaction system for deoxygenation for about 20 minutes, control the reaction system at 40°C (feeding temperature), after the system is mixed evenly, heat up the system in stages to reach the polymerization reaction initiation temperature of 46°C, the polymerization reaction temperature of 50°C and the polymerization reaction aging temperature of 70°C, after each stage reacts for 3 hours, cool to 30°C, add 5 parts of glyoxal aqueous solution, react at 30°C for 3 hours. Add water to adjust the solid content between 6-7%, heat up to about 120, and set aside.

[0028] Add 100g of rosin to the bottom of the reactor, heat and melt to 170°C, start stirring, add 10g of maleic anhydride modifier, heat to 190°C, and keep warm for 2 hours; take 200g of the above-prepared emulsifier, pass the emulsifier and rosin liquid into the mixer for pre-emulsification, enter the homogenizer for high-pressure homogenization at 25MPa, discharge, cool, add 10g of aluminum sulfate to 10g of water and dissolve it in the rosin emulsion, stir 0.3g of emulsified silicone oil defoamer evenly, adjust the required solid content to obtain cationic rosin glue.

[0029] Example 2

[0030] 30 parts of dimethyldiallylammonium chloride, 12 parts of acrylamide, 15 parts of methacryloyloxyethyltrimethylammonium chloride, the content after dilution with water is 50%, add 0.005% EDTA (accounting for the mass of monomer aqueous solution) and potassium persulfate / sodium bisulfite, the mass ratio of potassium persulfate / sodium bisulfite to monomer is 0.015:1, potassium persulfate / sodium bisulfite is diluted with water to a 5% aqueous solution, stir evenly and pass nitrogen to deoxygenate the reaction system 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 the polymerization reaction initiation temperature of 46°C, the polymerization reaction temperature of 50°C and the polymerization reaction aging temperature of 70°C, after each stage reacts for 3 hours, cool to 30°C, add 5 parts of glyoxal aqueous solution, react at 30°C for 3 hours. Add water to adjust the solid content between 6-7%, heat up to about 120, and set aside.

[0031] Add 100g of rosin to the bottom of the reactor, heat and melt to 170°C, start stirring, add 6g of modifier maleic acid, heat to 190°C, and keep warm for 2 hours; take 200g of the above-prepared emulsifier, pass the emulsifier and rosin liquid into a static mixer for pre-emulsification, enter a homogenizer for high-pressure homogenization at 25MPa, discharge, cool, add 15g of crystalline aluminum chloride to 15g of water and dissolve it in the rosin emulsion, stir 0.5g of a polyether defoamer evenly, and adjust the required solid content to obtain cationic rosin glue.

[0032] Example 3

[0033] 15 parts of dimethyldiallylammonium chloride, 8 parts of acrylamide, 15 parts of methacryloyloxyethyltrimethylammonium chloride, the content after dilution with water is 50%, add 0.009% EDTA (accounting for the mass of monomer aqueous solution) and potassium persulfate, the mass ratio of potassium persulfate to monomer is 0.01:1, potassium persulfate is diluted with water to a 5% aqueous solution, stirred evenly and nitrogen is passed 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 the polymerization reaction initiation temperature of 46°C, the polymerization reaction temperature of 50°C and the polymerization reaction aging temperature of 70°C, after each stage reacts for 3 hours, cool to 30°C, add glyoxal aqueous solution, and react at 30°C for 3 hours. Adjust the solid content between 6-7%, heat up to about 120, and set aside.

[0034] Add 80g of rosin to the bottom of the reactor, heat and melt to 170°C, start stirring, add 10g of the modifier, butenedioic acid, heat to 190°C, and keep warm for 2 hours; take 200g of the above-prepared emulsifier, pass the emulsifier and rosin liquid into a static mixer for pre-emulsification, enter a homogenizer for high-pressure homogenization at 20MPa, discharge, cool, add 10g of polyaluminum chloride to 10g of water and dissolve it in the rosin emulsion, stir 0.2g of a high-carbon alcohol defoamer evenly, adjust the required solid content to obtain cationic rosin glue.

[0035] Comparative Example

[0036] Take commercially available PAE emulsifier and adjust the solid content to between 6-7%, raise the temperature to about 120°C, and set aside.

[0037] Add 80g of rosin to the bottom of the reactor, heat and melt to 170°C, start stirring, add 10g of the modifier, butenedioic acid, heat to 190°C, and keep warm for 2 hours; take 200g of emulsifier, pass the emulsifier and rosin liquid into a static mixer for pre-emulsification, enter a homogenizer for high-pressure homogenization at 20MPa, discharge, cool, add 10g of polyaluminum chloride to 10g of water and dissolve it, then add it to the rosin emulsion, stir 0.2g of a high-carbon alcohol defoamer evenly, adjust the required solid content to obtain cationic rosin glue.

[0038] The cationic rosin glue prepared in each of the above examples was observed and measured (chloropropanol detection method FCM-3-702-167 (GC-MS)). The results are shown in Table 1.

[0039] Table 1 Performance indexes of cationic dispersed rosin glue

[0040]

[0041] It can be seen from the test results that the chlorine-free cationic dispersed rosin glue prepared by the present invention has better chemical stability and mechanical stability than the comparative example, and the storage stability reaches 6 months, which is significantly better than the comparative sample, indicating that the emulsifier used in the present invention has a better effect of stabilizing the cationic dispersed rosin glue.

[0042] 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 preparing a chloride-free cationic dispersed rosin glue, characterized in that: The steps include: S1. Dimethyldiallylammonium chloride, acrylamide, and methacryloyloxyethyltrimethylammonium chloride are diluted with water in proportion and mixed evenly, and appropriate amounts of EDTA and initiator are slowly added. The system is heated in stages to reach a polymerization initiation temperature of 46-48°C, a polymerization temperature of 50-55°C, and a polymerization aging temperature of 70-75°C, respectively. Each stage reacts for 2-4 hours, then cools to 30-35°C, adds glyoxal, and reacts at this temperature for 2-4 hours to obtain a cationic emulsifier; S2, heating and melting the rosin, adding a modifier to fully react, and obtaining a modified rosin liquid; S3, introducing the cationic emulsifier into the modified rosin solution, and fully pre-emulsifying it under the action of a mixer; S4, passing the pre-emulsified mixed solution into a high-pressure homogenizer for homogenization, adding aluminum salt and defoaming agent after cooling, and obtaining the chloride-free cationic dispersed rosin glue.

2. The method according to claim 1, characterized in that The weight proportions of the components are as follows: 50-100 parts of rosin, 5-10 parts of modifier, 80-120 parts of cationic emulsifier, 10-15 parts of aluminum salt, and 0.1-0.5 parts of defoamer.

3. The method according to claim 1, characterized in that In step S1, the amounts of the three monomers are: 15-30 parts of dimethyldiallylammonium chloride, 8-12 parts of acrylamide, and 5-15 parts of methacryloyloxyethyltrimethylammonium chloride, and the amount of glyoxal added is 1-10% of the total amount of the three monomers.

4. 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, and the mass ratio of the initiator to the mixed monomer is 0.005-0.015:

1.

5. The method according to claim 1, characterized in that In step S1, the three monomers are diluted with water to form a 20-50 wt% monomer mixture, and the amount of EDTA added is 0.001-0.01 wt% of the mass of the monomer mixture.

6. The method according to claim 1, characterized in that The modifier is selected from at least one of butenedioic acid, maleic acid and maleic anhydride.

7. The method according to claim 6, characterized in that The modified rosin liquid is prepared by reacting rosin and a modifier at 180-195° C. for 1-3 hours.

8. The method according to claim 1, characterized in that The aluminum salt is selected from at least one of aluminum sulfate, polyaluminum chloride, and crystalline aluminum chloride; the defoaming agent is selected from at least one of emulsified silicone oil, high-carbon alcohol complex, polyether, and polydimethylsiloxane.

9. The method according to claim 1, characterized in that The temperature control range of the mixer in step S3 is 150-155° C., and in step S4, the homogenizing pressure of the homogenizer is: low pressure 8-10 MPa, high pressure 25-30 MPa.

10. Chlorine-free cationic dispersed rosin glue prepared according to the method according to any one of claims 1 to 9.

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