A paper box special paper pulp and its preparation method

Abstract

The application discloses a paper box special paper pulp and a preparation method thereof, and relates to the technical field of papermaking industry. The paper box special paper pulp prepared in the application comprises paper pulp raw pulp and a self-made defoaming agent. The self-made defoaming agent comprises cyclic oligomeric acid ester, silicon paste, polyether modified hydrogen-containing silicone oil, emulsifier and thickening agent. The silicon paste comprises methyl silicone oil, silicone rubber and silicon dioxide. The self-made defoaming agent is not only a high-efficiency defoaming agent with the advantages of organic silicon defoaming agent and polyether defoaming agent, but also enhances the defoaming property of the self-made defoaming agent by combining the organic silicon defoaming agent with the cyclic oligomeric acid ester and lowering the surface tension of the paper pulp raw pulp after the polyether modified hydrogen-containing silicone oil is blended with the cyclic oligomeric acid ester.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of papermaking industry, in particular to a special paper pulp for paper boxes and a preparation method thereof. BACKGROUND

[0002] Paper boxes are the most widely used packaging products. According to different materials, there are corrugated paper boxes, single-layer paperboard boxes, etc. There are various specifications and models. Commonly used paper boxes are three layers, five layers, and seven layers are less used. Each layer is divided into inner paper, corrugated paper, core paper, and surface paper. Inner and surface paper are tea board paper and kraft paper. Core paper is corrugated paper. The colors and textures of various papers are different, and the papers produced by different manufacturers (color and texture) are also different. With the rapid development of economy and science and technology, people's life rhythm is getting faster and faster, and express paper boxes have become a consumable product commonly used by people

[0003] The paper pulp raw pulp for making paper boxes is mainly made of plant fibers. Although natural plant cellulose contains a large number of hydroxyl groups, it is not soluble in water. The surface and interior of the small fibers will adsorb a large number of small bubbles. Due to the special structure of plant fibers, the bubbles attached thereto are difficult to eliminate with ordinary defoaming agents, thereby affecting the quality of the paper box. Therefore, the present application researches and prepares a special paper pulp for paper boxes to solve this problem. SUMMARY

[0004] The purpose of the present application is to provide a special paper pulp for paper boxes and a preparation method thereof to solve the problems in the background art.

[0005] In order to solve the above technical problems, the present application provides the following technical scheme: a special paper pulp for paper boxes, which comprises paper pulp raw pulp and a self-made defoaming agent. The self-made defoaming agent comprises a cyclic oligomeric acid ester, silicon paste, polyether modified hydrogen-containing silicone oil, an emulsifier and a thickening agent. The silicon paste comprises methyl silicone oil, silicone rubber and silicon dioxide.

[0006] Preferably, the cyclic oligomeric acid ester is prepared by reacting modified phthalic acid with terephthaloyl chloride, then oxidizing with potassium permanganate, and then reacting with a polyether ester block copolymer.

[0007] Preferably, the modified phthalic acid is prepared by reacting pyromellitic anhydride with m-diethylbenzene, and the polyether ester block copolymer is prepared by reacting polyethylene glycol with terephthalate butylene glycol cyclic oligomer.

[0008] Preferably, the polyether modified hydrogen-containing silicone oil is prepared by reacting allyl polyoxyethylene polyoxypropylene methyl ether with phenyl oxygen-containing silicone oil.

[0009] Preferably, a preparation method of a special paper pulp for paper boxes comprises the following specific steps:

[0010] (1) Under the atmosphere of nitrogen, anhydrous dichloromethane, triethylamine, 1,4-diazabicyclo[2,2,2]octane are mixed in the mass ratio of 55-65:2:1.12, and after being stirred uniformly in an ice bath at 100-200 rpm, the mixed solution of triethylamine in the mass of 9.1-9.3 times is added dropwise at a rate of 2-4 mL / min, the mass ratio of terephthaloyl chloride, modified phthalic acid, tetrahydrofuran and chloroform in the mixed solution is 2:0.5-0.7:8:8, after the dropwise addition is completed, the reaction is continued for 25-35 min, it is quenched with concentrated ammonia water and filtered, and finally it is washed with dichloromethane for 3-5 times to prepare a cyclic oligomeric acid ester base body;

[0011] (2) The cyclic oligomeric acid ester base body is dissolved in chloroform, potassium permanganate in the mass of 0.6-0.8 times of the mass of the cyclic oligomeric acid ester base body is added, and concentrated sulfuric acid in the mass of 0.04-0.06 times of the mass of the cyclic oligomeric acid ester base body is added dropwise at a rate of 1-3 mL / min, the reaction is carried out for 3-5 h, polyether ester block copolymer in the mass of 3.3-3.7 times of the mass of the cyclic oligomeric acid ester base body is added, the temperature is raised to 80-90℃, concentrated sulfuric acid in the mass of 0.04-0.06 times of the mass of the cyclic oligomeric acid ester base body is added dropwise at a rate of 1-3 mL / min, the reaction is continued for 8-12 h, after being cooled to room temperature, it is precipitated with petroleum ether, filtered and vacuum dried to prepare a cyclic oligomeric acid ester;

[0012] (3) The silicone paste, the cyclic oligomeric acid ester and the polyether modified hydrogen-containing silicone oil are mixed in the mass ratio of 5:2:1-2, the temperature is raised to 60-62℃, after being stirred uniformly, the emulsifier in the mass of 0.3-0.4 times of the mass of the silicone paste is added, after being uniformly stirred and kept warm, the temperature is lowered to 40-42℃, shearing is carried out at a rate of 5000-6000 rpm for 8-10 min, it is homogenized by a colloid mill, the thickening agent in the mass of 1.2-1.3 times of the mass of the silicone paste is added, after being stirred uniformly, the water in the mass of 2-3 times of the mass of the silicone paste is added for dilution to prepare a self-made defoaming agent;

[0013] (4) The paper pulp is placed in a reaction kettle, a beater is used to stir at a rate of 500-800 rpm for 1-2 h, the self-made defoaming agent in the mass of 0.004-0.008 times of the mass of the paper pulp is added dropwise at a rate of 1-3 mL / min, the stirring is continued for 1-2 h to discharge to prepare a special paper pulp for carton.

[0014] Preferably, in the above step (1), the preparation method of the modified phthalic acid is as follows: pyromellitic anhydride, anhydrous aluminum chloride and m-diethylbenzene are mixed in the mass ratio of 1:3:23-25, the temperature is raised to 65-70℃, after being stirred at 50-60 rpm for 3-4 h, the hydrochloric acid solution in the mass fraction of 2-4% in the mass of 16-18 times of pyromellitic anhydride is added, the temperature is raised to 142-145℃, after distillation to remove m-diethylbenzene, it is transferred to the 1 mol / L potassium hydroxide solution in the mass of 18-20 times of pyromellitic anhydride, it is filtered and precipitated with hydrochloric acid, it is filtered and dried to prepare the modified phthalic acid.

[0015] Preferably, in the step (2), the preparation method of the polyether ester block copolymer is as follows: terephthalate butylene glycol cyclic oligomer, polyethylene glycol and tetrachloroethane are mixed in a mass ratio of 1:1-2:18-20 under nitrogen atmosphere, heated to 146-148 DEG C, reacted for 30-50 min, then 0.002-0.006 times of polyethylene glycol of catalyst isopropyl titanate is added, and the reaction is continued for 3-5 h, then the product is transferred into petroleum ether for precipitation and filtration, extracted with ethyl acetate for 24 h, and finally dried to obtain the polyether ester block copolymer.

[0016] Preferably, in the step (3), the preparation method of the polyether modified hydrogen-containing silicone oil is as follows: phenyl oxygen-containing silicone oil, allyl polyoxyethylene polyoxypropylene methyl ether and isopropyl alcohol are mixed in a mass ratio of 1:1.2-1.4:8-10, heated to 70-72 DEG C, stirred uniformly, then 0.002-0.004 times of catalyst chloroplatinic acid of phenyl oxygen-containing silicone oil is added, heated to 120-124 DEG C, reacted for 2-4 h, cooled to 48-52 DEG C, and distilled under reduced pressure at 0.07-0.09 MPa to obtain the polyether modified hydrogen-containing silicone oil.

[0017] Preferably, in the step (3), the preparation method of the silicone paste is as follows: 500 mPa.s methyl silicone oil, 1000 mPa.s methyl silicone oil, 5000 mPa.s 107 silicone rubber, 20000 mPa.s 107 silicone rubber and silicon dioxide are mixed in a mass ratio of 4:6:2:2:1-1.2, stirred and heated to 130-140 DEG C at 100-300 rpm, heated to 180-185 DEG C after reacting for 2-3 h, and then stirred and reacted for 50-70 min to obtain the silicone paste.

[0018] Preferably, in the step (3), the mass ratio of Span-60 and Span-80 in the emulsifier is 1:1, and the thickening agent is a sodium carboxymethyl cellulose aqueous solution with a mass fraction of 2-3%.

[0019] Compared with the prior art, the paper box special paper pulp prepared by the method has the advantages that:

[0020] The paper box special paper pulp prepared by the method comprises paper pulp raw pulp and a self-made defoaming agent; the self-made defoaming agent comprises cyclic oligomeric acid ester, silicone paste, polyether modified hydrogen-containing silicone oil, emulsifier and thickening agent, and the silicone paste comprises methyl silicone oil, silicone rubber and silicon dioxide.

[0021] The cyclic oligomeric acid ester is prepared by reacting modified phthalic acid with terephthaloyl chloride, then oxidizing with potassium permanganate, and then reacting with a polyether ester block copolymer, and the polyether ester block copolymer is prepared by reacting polyethylene glycol with a cyclic oligomer of butylene terephthalate; the modified phthalic acid is prepared by reacting pyromellitic anhydride with m-diethylbenzene, and after the reaction of pyromellitic anhydride with m-diethylbenzene, three benzene rings are connected by carbonyl groups to form a chain structure, which has high stability and good dispersing force; after the reaction with terephthaloyl chloride, a cyclic oligomer is formed, which can reduce the viscosity, and after oxidation with potassium permanganate, the ethyl group is oxidized to a carboxyl group, and then reacted with a hydroxyl-terminated polyether ester block copolymer to form a cross-linked cyclic oligomeric acid ester with the cyclic oligomeric ester as the cross-linking center and the polyether ester block copolymer as the branched chain, the lipophilicity is increased, the hydrophilicity is reduced, and the self-made defoamer can be easily aggregated at the gas-liquid interface when added to the pulp stock, so that the self-made defoamer can be quickly absorbed by the bubble film, enter and diffuse in the bubble film, thereby achieving the purpose of rapid defoaming.

[0022] The polyether-modified hydrogen-containing silicone oil is prepared by reacting allyl polyoxyethylene polyoxypropylene methyl ether with phenyl oxygen-containing silicone oil, and a hydrophilic two-block polyether is introduced into the hydrophobic phenyl oxygen-containing silicone oil. The polyether-modified hydrogen-containing silicone oil is not only a high-efficiency defoamer that combines the advantages of organic silicon defoamer and polyether defoamer, but also a composite defoaming component formed by combining the organic silicon defoamer and the cyclic oligomeric acid ester after being blended with the polyether ester block copolymer. The surface tension of the pulp stock is rapidly reduced after the composite defoaming component is added to the pulp stock, thereby enhancing the defoaming property of the self-made defoamer. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The pulp stock in the present application is purchased from Shijiazhuang Pengye Mining Products Co., Ltd.

[0024] In order to more clearly illustrate the method provided by the present application, the following examples are used to illustrate the method in detail. The test methods of various indexes of the carton special paper pulp prepared in the examples and comparative examples are as follows:

[0025] Defoaming property: 100 mL graduated cylinders containing 50 mL of pulp stock, carton special paper pulp of the examples and comparative examples, were shaken up and down 20 times at a speed of 2 times / s, and the defoaming time was measured by starting a stopwatch. When the foam decreased to 60 mL, the time used was the defoaming time.

[0026] Foam suppression: 100 mL of pulp stock, the paper box special paper pulp of the examples and the comparative examples were added into the cylinder, respectively, and then nitrogen was bubbled to control the flow rate of nitrogen at 2 L / min. When the foam height reached the 200 mL mark, the time taken was the foam suppression time.

[0027] Example 1

[0028] (1) Mixed pyromellitic anhydride, anhydrous aluminum chloride and m-diethylbenzene according to the mass ratio of 1:3:23, heated to 65℃, stirred at 50 rpm for 3h, then added 16 times the mass of pyromellitic anhydride of 2% hydrochloric acid solution, heated to 142℃, after distillation removal of m-diethylbenzene, transferred to 18 times the mass of pyromellitic anhydride of 1 mol / L potassium hydroxide solution, filtered and precipitated with hydrochloric acid, filtered and dried to obtain modified phthalic acid; under nitrogen atmosphere, mixed anhydrous dichloromethane, triethylamine, 1,4-diazabicyclo[2,2,2]octane according to the mass ratio of 55:2:1.12, stirred uniformly in ice bath, 100 rpm, then added 9.1 times the mass of triethylamine of the mixed solution at a rate of 2mL / min, the mass ratio of terephthaloyl chloride, modified phthalic acid, tetrahydrofuran and chloroform in the mixed solution was 2:0.5:8:8, after the completion of dropwise addition, continued to react for 25min, quenched with concentrated ammonia and suction filtered, finally washed with dichloromethane for 3 times to obtain the cyclic oligomeric acid ester matrix;

[0029] (2) Under nitrogen atmosphere, mixed terephthalate cyclic oligomer, polyethylene glycol and tetrachloroethane according to the mass ratio of 1:1:18 to heat to 146℃, reacted for 30min, then added 0.002 times the mass of polyethylene glycol of catalyst isopropyl titanate, continued to react for 3h, transferred to petroleum ether to precipitate and filter, then extracted with ethyl acetate for 24h, finally dried to obtain polyether ester block copolymer; the cyclic oligomeric acid ester matrix was dissolved with chloroform, added 0.6 times the mass of the cyclic oligomeric acid ester matrix of potassium permanganate, and added 0.04 times the mass of the cyclic oligomeric acid ester matrix of concentrated sulfuric acid at a rate of 1mL / min, reacted for 3h, added 3.3 times the mass of the cyclic oligomeric acid ester matrix of polyether ester block copolymer, heated to 80℃, added 0.04 times the mass of the cyclic oligomeric acid ester matrix of concentrated sulfuric acid at a rate of 1mL / min, continued to react for 8h, cooled to room temperature, precipitated with petroleum ether, suction filtered and vacuum dried to obtain the cyclic oligomeric acid ester;

[0030] (3) mixed phenyl oxygen-containing silicone oil, allyl polyoxyethylene polyoxypropylene methyl ether and isopropyl alcohol according to the mass ratio of 1:1.2:8, heated to 70℃, stirred uniformly, then added 0.002 times the mass of the catalyst chloroplatinic acid in phenyl oxygen-containing silicone oil, heated to 120℃, reacted for 2h, cooled to 48℃, distilled under reduced pressure at 0.07MPa, to obtain polyether modified hydrogen-containing silicone oil; mixed 500mPa·s methyl silicone oil, 1000mPa·s methyl silicone oil, 5000mPa·s 107 silicone rubber, 20000mPa·s 107 silicone rubber and silica according to the mass ratio of 4:6:2:2:1, stirred at 100rpm, heated to 130℃, reacted for 2h, then heated to 180℃, continued to stir for 50min, to obtain silicone paste; mixed silicone paste, cyclic oligomeric acid ester and polyether modified hydrogen-containing silicone oil according to the mass ratio of 5:2:1, heated to 60℃, stirred uniformly, then added 0.3 times the mass of the emulsifier in silicone paste, the mass ratio of Span-60 and Span-80 in the emulsifier was 1:1, kept uniform stirring at 60℃, then cooled to 40℃, sheared at a speed of 5000rpm for 8min, then homogenized by colloid mill, then added 1.2 times the mass of the thickening agent in silicone paste, the thickening agent was 2% carboxymethyl cellulose sodium aqueous solution, stirred uniformly, then diluted with 2 times the mass of water in silicone paste, to obtain self-made defoamer;

[0031] (4) placed the pulp stock in a reaction kettle, stirred at a speed of 500rpm for 1h by a beater, then added 0.004 times the mass of the self-made defoamer in the pulp stock at a rate of 1mL / min, continued to stir for 1h, then discharged, to obtain special paper pulp for carton.

[0032] Example 2

[0033] (1) mixed pyromellitic anhydride, anhydrous aluminum chloride and m-diethylbenzene according to the mass ratio of 1:3:24, heated to 68℃, stirred at 55rpm for 3.5h, then added 17 times the mass of the hydrochloric acid solution with a mass fraction of 3% in pyromellitic anhydride, heated to 144℃, distilled to remove m-diethylbenzene, then transferred to 19 times the mass of the 1mol / L potassium hydroxide solution in pyromellitic anhydride, filtered and precipitated with hydrochloric acid, filtered and dried, to obtain modified phthalic acid; mixed anhydrous dichloromethane, triethylamine and 1,4-diazabicyclo[2,2,2]octane according to the mass ratio of 60:2:1.12, stirred uniformly in an ice bath at 150rpm, then added 9.2 times the mass of the mixture in triethylamine at a rate of 3mL / min, the mass ratio of terephthaloyl chloride, modified phthalic acid, tetrahydrofuran and chloroform in the mixture was 2:0.6:8:8, continued to react for 30min after the completion of the dropwise addition, quenched with concentrated ammonia water and suction filtered, finally washed with dichloromethane for 4 times, to obtain cyclic oligomeric acid ester matrix;

[0034] (2) Under a nitrogen atmosphere, cyclic oligomer of butylene terephthalate, polyethylene glycol, and tetrachloroethane were mixed at a mass ratio of 1:1.5:19 and heated to 147°C. After reacting for 40 min, 0.004 times the mass of polyethylene glycol catalyst isopropyl titanate was added, and the reaction was continued for 4 h. The mixture was then transferred to petroleum ether to precipitate and filtered. After extraction with ethyl acetate for 24 h, the mixture was dried to obtain a polyether ester block copolymer. The cyclic oligoester matrix was dissolved in chloroform, and the cyclic oligomer was added... Potassium permanganate (0.7 times the mass of the polyester matrix) was added dropwise with concentrated sulfuric acid (0.05 times the mass of the cyclic oligoester matrix) at a rate of 2 mL / min. The reaction was carried out for 4 h. Then, polyether ester block copolymer (3.5 times the mass of the cyclic oligoester matrix) was added. The temperature was raised to 85 °C, and concentrated sulfuric acid (0.05 times the mass of the cyclic oligoester matrix) was added dropwise at a rate of 2 mL / min. The reaction was continued for 10 h. After cooling to room temperature, the product was precipitated with petroleum ether, filtered, and vacuum dried to obtain the cyclic oligoester.

[0035] (3) Phenyl oxygen-containing silicone oil, allyl polyoxyethylene polyoxypropylene methyl ether and isopropanol were mixed in a mass ratio of 1:1.3:9, heated to 71°C, stirred evenly, and then 0.003 times the mass of phenyl oxygen-containing silicone oil catalyst chloroplatinic acid was added. The mixture was heated to 122°C and reacted for 3 hours. The mixture was then cooled to 50°C and distilled under reduced pressure at 0.08 MPa to obtain polyether-modified hydrogen-containing silicone oil. Methyl silicone oil of 500 mPa·s, methyl silicone oil of 1000 mPa·s, 107 silicone rubber of 5000 mPa·s, 107 silicone rubber of 20000 mPa·s and silica were mixed in a mass ratio of 4:6:2:2:1.1, stirred at 200 rpm and heated to 135°C for 2 hours. After 5 hours, the temperature was raised to 183℃, and the reaction was continued for 60 minutes to obtain silicone paste. The silicone paste, cyclic oligomeric ester and polyether-modified hydrogen-containing silicone oil were mixed in a mass ratio of 5:2:1.5, heated to 61℃, and stirred evenly. Then, 0.35 times the mass of the silicone paste emulsifier was added, in which the mass ratio of Span-60 and Span-80 in the emulsifier was 1:1. After keeping warm and stirring evenly, the temperature was lowered to 41℃, and sheared at a rate of 5500 rpm for 9 minutes. Then, it was homogenized by colloid milling. Then, 1.25 times the mass of the silicone paste thickener was added, in which the mass fraction of the thickener was 2.5% sodium carboxymethyl cellulose aqueous solution. After stirring evenly, 2.5 times the mass of the silicone paste water was added to dilute it to obtain a self-made defoamer.

[0036] (4) Place the pulp in a reactor and stir it at 700 rpm for 1.5 h with a pulper. Add 0.006 times the weight of the pulp with a self-made defoamer at a rate of 2 mL / min. Continue stirring for 1.5 h and discharge the pulp to obtain special pulp for cardboard boxes.

[0037] Example 3

[0038] (1) The pyromellitic anhydride, anhydrous aluminum chloride and m-diethylbenzene were mixed in a mass ratio of 1:3:25, heated to 70°C, stirred at 60 rpm for 4h, then 18 times the mass of pyromellitic anhydride was added 4% hydrochloric acid solution, heated to 145°C, distilled to remove m-diethylbenzene, then transferred to 20 times the mass of pyromellitic anhydride 1 mol / L potassium hydroxide solution, filtered and precipitated with hydrochloric acid, filtered and dried to obtain modified phthalic acid; under nitrogen atmosphere, anhydrous dichloromethane, triethylamine, 1,4-diazabicyclo[2,2,2]octane were mixed in a mass ratio of 65:2:1.12, stirred in an ice bath at 200 rpm, then 9.3 times the mass of triethylamine was added at a rate of 4mL / min, the mass ratio of terephthaloyl chloride, modified phthalic acid, tetrahydrofuran and chloroform in the mixed solution was 2:0.7:8:8, after the addition was completed, the reaction was continued for 35min, quenched with concentrated ammonia and filtered, then washed with dichloromethane 5 times to obtain a cyclic oligomeric acid ester matrix;

[0039] (2) Under nitrogen atmosphere, the terephthalate cyclic oligomer, polyethylene glycol and tetrachloroethane were mixed in a mass ratio of 1:2:20 to heat to 148°C, reacted for 50min, then 0.006 times the mass of polyethylene glycol was added as catalyst isopropyl titanate, and the reaction was continued for 5h, then transferred to petroleum ether to precipitate and filter, then extracted with ethyl acetate for 24h, and finally dried to obtain a polyether ester block copolymer; the cyclic oligomeric acid ester matrix was dissolved in chloroform, 0.8 times the mass of potassium permanganate was added, and 0.06 times the mass of concentrated sulfuric acid was added at a rate of 3mL / min, reacted for 5h, then 3.7 times the mass of polyether ester block copolymer was added, heated to 90°C, and 0.06 times the mass of concentrated sulfuric acid was added at a rate of 3mL / min, and the reaction was continued for 12h, then cooled to room temperature, precipitated with petroleum ether, filtered and vacuum dried to obtain a cyclic oligomeric acid ester;

[0040] (3) mixed phenyl oxygen-containing silicone oil, allyl polyoxyethylene polyoxypropylene methyl ether and isopropyl alcohol according to the mass ratio of 1:1.4:10, heated to 72℃, stirred uniformly, then added 0.004 times the mass of the catalyst chloroplatinic acid of the phenyl oxygen-containing silicone oil, heated to 124℃, reacted for 4h, cooled to 52℃, distilled under reduced pressure at 0.09MPa, to obtain polyether modified hydrogen-containing silicone oil; mixed 500mPa·s methyl silicone oil, 1000mPa·s methyl silicone oil, 5000mPa·s 107 silicone rubber, 20000mPa·s 107 silicone rubber and silica according to the mass ratio of 4:6:2:2:1.2, stirred at 300rpm, heated to 140℃, reacted for 3h, then heated to 185℃, continued to stir for 70min, to obtain silicone paste; mixed the silicone paste, cyclic oligomeric acid ester and polyether modified hydrogen-containing silicone oil according to the mass ratio of 5:2:2, heated to 62℃, stirred uniformly, then added 0.4 times the mass of the emulsifier of the silicone paste, the mass ratio of Span-60 and Span-80 in the emulsifier was 1:1, kept uniform stirring, then cooled to 42℃, sheared at the speed of 6000rpm for 10min, then homogenized by colloid mill, then added 1.3 times the mass of the thickening agent of the silicone paste, the thickening agent was 3% carboxymethyl cellulose sodium aqueous solution, stirred uniformly, then diluted with 3 times the mass of water of the silicone paste, to obtain self-made defoamer;

[0041] (4) placed the paper pulp in a reaction kettle, stirred at the speed of 800rpm for 2h by a beater, added 0.008 times the mass of the self-made defoamer of the paper pulp at the rate of 3mL / min, continued to stir for 2h, then discharged, to obtain paper box special paper pulp.

[0042] Comparative Example 1

[0043] The prescription composition of Comparative Example 1 was the same as that of Example 2. The difference between the preparation method of the paper box special paper pulp and that of Example 2 was that the cyclic oligomeric acid ester was prepared by reacting modified phthalic acid with terephthaloyl chloride, then oxidizing with potassium permanganate.

[0044] Comparative Example 2

[0045] The prescription composition of Comparative Example 2 was the same as that of Example 2. The difference between the preparation method of the paper box special paper pulp and that of Example 2 was that the cyclic oligomeric acid ester was prepared by reacting modified phthalic acid with terephthaloyl chloride, then oxidizing with potassium permanganate.

[0046] Comparative Example 3

[0047] The prescription composition of Comparative Example 3 was the same as that of Example 2. The difference between the preparation method of the paper box special paper pulp and that of Example 2 was that the self-made defoamer only included cyclic oligomeric acid ester, silicone paste, emulsifier and thickening agent.

[0048] Comparative Example 4

[0049] The prescription composition of Comparative Example 4 is the same as that of Example 2. The difference between the preparation method of the carton special paper pulp of this example and that of Example 2 is that the self-made defoaming agent only comprises silicone paste, polyether modified hydrogen-containing silicone oil, emulsifier and thickening agent.

[0050] Effect Example

[0051] The following Table 1 shows the performance analysis results of the carton special paper pulp using the carton special paper pulp of Examples 1 to 3 and Comparative Examples 1 to 4 of the present application:

[0052] Table 1

[0053] Defoaming time (s) Foam suppression time (min) Blank (pulp stock) Foam did not subside to 60 mL 21.9 Example 1 14.6 34.6 Example 2 13.7 36.2 Example 3 14.1 35.7 Comparative Example 1 26.2 33.2 Comparative Example 2 27.5 32.7 Comparative Example 3 29.8 31.3 Comparative Example 4 32.4 27.8

[0054] As can be obviously seen from the comparison of the experimental data of the examples and comparative examples in Table 1, the defoaming property and the foam suppressing property of the carton special paper pulp prepared in Examples 1, 2 and 3 are better.

[0055] As can be seen from the comparison of the experimental data of Example 1, Example 2, Example 3 and the blank group, Comparative Example 1 and Comparative Example 2, the modified phthalic acid prepared by the reaction of trimellitic anhydride and m-diethylbenzene, after the reaction with terephthaloyl chloride and the oxidation with potassium permanganate, and then the reaction with the polyether ester block copolymer, forms a cross-linked cyclic oligomeric acid ester with the cyclic oligomeric ester as the cross-linking center and the polyether ester block copolymer as the branched chain, the lipophilicity increases and the hydrophilicity decreases, and the self-made defoaming agent is easy to gather at the gas-liquid interface when added into the paper pulp stock, so that the self-made defoaming agent can be quickly absorbed by the bubble film, enter and diffuse in the bubble film, thereby achieving the purpose of rapid defoaming.

[0056] As can be seen from the comparison of the experimental data of Example 1, Example 2, Example 3 and the blank group, Comparative Example 2, Comparative Example 3 and Comparative Example 4, the polyether modified hydrogen-containing silicone oil prepared by the reaction of allyl polyoxyethylene polyoxypropylene methyl ether and phenyl oxygen-containing silicone oil is not only a high-efficiency defoaming agent with the advantages of both silicone defoaming agent and polyether defoaming agent, but also a composite defoaming component after being blended with the cyclic oligomeric acid ester and the polyether ester block copolymer, which attracts each other, combines the silicone defoaming agent with the cyclic oligomeric acid ester, and rapidly reduces the surface tension after being added into the paper pulp stock, thereby enhancing the defoaming property of the self-made defoaming agent.

[0057] It is apparent for those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the present application being defined by the appended claims rather than the foregoing description, and all changes coming within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims concerned.

Claims

1. A special pulp for cardboard boxes, characterized in that, The cardboard pulp for cardboard boxes includes virgin pulp and a self-made defoamer; the self-made defoamer includes cyclic oligomeric esters, silicone paste, polyether-modified hydrogen-containing silicone oil, emulsifiers, and thickeners; the silicone paste includes methyl silicone oil, silicone rubber, and silica; the cyclic oligomeric ester is prepared by reacting modified phthalic acid with terephthaloyl chloride to obtain a cyclic oligomeric ester matrix, which is then oxidized with potassium permanganate and reacted with a polyether ester block copolymer; the mass ratio of the cyclic oligomeric ester matrix to the polyether ester block copolymer is 1:3.3~3.7; the modified phthalic acid is prepared by reacting pyromellitic anhydride with m-diethylbenzene; the polyether ester block copolymer is prepared by reacting polyethylene glycol with butylene terephthalate cyclic oligomers.

2. The cardboard pulp for cardboard boxes according to claim 1, characterized in that, The polyether-modified hydrogen-containing silicone oil is prepared by reacting allyl polyoxyethylene polyoxypropylene methyl ether with phenyl oxygen-containing silicone oil.

3. A method for preparing pulp specifically for cardboard boxes, characterized in that, The method for preparing the pulp specifically for cardboard boxes includes the following specific steps: (1) Under a nitrogen atmosphere, anhydrous dichloromethane, triethylamine, and 1,4-diazabicyclo[2,2,2]octane were mixed in a mass ratio of 55~65:2:1.

12. After stirring evenly in an ice bath at 100~200 rpm, a mixture of 9.1~9.3 times the mass of triethylamine was added dropwise at a rate of 2~4 mL / min. The mass ratio of terephthaloyl chloride, modified phthalic acid, tetrahydrofuran, and trichloromethane in the mixture was 2:0.5~0.7:8:

8. After the addition was completed, the reaction was continued for 25~35 min. The mixture was quenched with concentrated ammonia and filtered. Finally, it was washed with dichloromethane 3~5 times to obtain a cyclic oligomeric ester matrix. (2) Dissolve the cyclic oligomeric ester matrix in chloroform, add potassium permanganate at 0.6 to 0.8 times the mass of the cyclic oligomeric ester matrix, and add concentrated sulfuric acid at a rate of 1 to 3 mL / min at 0.04 to 0.06 times the mass of the cyclic oligomeric ester matrix. React for 3 to 5 h, add polyether ester block copolymer at 3.3 to 3.7 times the mass of the cyclic oligomeric ester matrix, heat to 80 to 90 °C, add concentrated sulfuric acid at a rate of 1 to 3 mL / min at 0.04 to 0.06 times the mass of the cyclic oligomeric ester matrix, continue to react for 8 to 12 h, cool to room temperature, precipitate with petroleum ether, filter and vacuum dry to obtain the cyclic oligomeric ester; (3) Mix silicone paste, cyclic oligomeric ester and polyether modified hydrogen-containing silicone oil in a mass ratio of 5:2:1~2, heat to 60~62℃, stir evenly, add emulsifier of 0.3~0.4 times the mass of silicone paste, keep warm and stir evenly, cool down to 40~42℃, shear at a rate of 5000~6000rpm for 8~10min, then homogenize by colloid mill, add thickener of 1.2~1.3 times the mass of silicone paste, stir evenly, add water of 2~3 times the mass of silicone paste to dilute, and obtain the self-made defoamer; (4) Place the pulp in a reactor and stir it at a speed of 500-800 rpm for 1-2 hours. Add 0.004-0.008 times the weight of the pulp to the self-made defoamer at a rate of 1-3 mL / min. Continue stirring for 1-2 hours and then discharge the pulp to obtain special pulp for cardboard boxes.

4. The method for preparing a special pulp for cardboard boxes according to claim 3, characterized in that, In step (1) above: the preparation method of modified phthalic acid is as follows: pyromellitic anhydride, anhydrous aluminum chloride and m-diethylbenzene are mixed in a mass ratio of 1:3:23~25, heated to 65~70℃, stirred at 50~60rpm for 3~4h, then hydrochloric acid solution with a mass fraction of 2~4% (16~18 times the mass of pyromellitic anhydride) is added, heated to 142~145℃, m-diethylbenzene is removed by distillation, and then transferred to a 1mol / L potassium hydroxide solution with a mass fraction of 18~20 times the mass of pyromellitic anhydride, filtered and precipitated with hydrochloric acid, filtered and dried to obtain modified phthalic acid.

5. The method for preparing a special pulp for cardboard boxes according to claim 3, characterized in that, In step (2) above: the preparation method of polyether ester block copolymer is as follows: under a nitrogen atmosphere, butylene terephthalate cyclic oligomer, polyethylene glycol and tetrachloroethane are mixed at a mass ratio of 1:1~2:18~20 and heated to 146~148℃. After reacting for 30~50 min, 0.002~0.006 times the mass of polyethylene glycol catalyst isopropyl titanate is added and the reaction continues for 3~5 h. The mixture is then transferred to petroleum ether to precipitate and filtered. After extraction with ethyl acetate for 24 h, the mixture is dried to obtain polyether ester block copolymer.

6. The method for preparing a special pulp for cardboard boxes according to claim 3, characterized in that, In step (3) above: the preparation method of polyether modified hydrogen-containing silicone oil is as follows: phenyl oxygen-containing silicone oil, allyl polyoxyethylene polyoxypropylene methyl ether and isopropanol are mixed in a mass ratio of 1:1.2~1.4:8~10, heated to 70~72℃, stirred evenly, and then 0.002~0.004 times the mass of phenyl oxygen-containing silicone oil catalyst chloroplatinic acid is added, heated to 120~124℃, reacted for 2~4h, cooled to 48~52℃, and distilled under reduced pressure at 0.07~0.09MPa to obtain polyether modified hydrogen-containing silicone oil.

7. The method for preparing a special pulp for cardboard boxes according to claim 3, characterized in that, In step (3) above: the preparation method of silicone paste is as follows: 500 mPa·s methyl silicone oil, 1000 mPa·s methyl silicone oil, 5000 mPa·s 107 silicone rubber, 20000 mPa·s 107 silicone rubber and silicon dioxide are mixed in a mass ratio of 4:6:2:2:1~1.2, stirred at 100~300 rpm and heated to 130~140℃, reacted for 2~3h, then heated to 180~185℃, and stirred for 50~70min to obtain silicone paste.

8. The method for preparing a special pulp for cardboard boxes according to claim 3, characterized in that, In step (3) above: the mass ratio of Span-60 and Span-80 in the emulsifier is 1:1; the thickener is a sodium carboxymethyl cellulose aqueous solution with a mass fraction of 2~3%.