CN107400176A - Hydroxypropyl cation guar gum and its water-medium semi-dry method preparation method and use - Google Patents

Abstract

The present invention provides a kind of hydroxypropyl cationic guar gum and its water medium semi-dry method preparation method and application thereof, the method comprises the following steps: (1) adding guar bean endosperm slices into hot water, Under the protection of gas, then add an aqueous alkalizing agent solution, soak and alkalize to obtain alkalized guar bean endosperm slices; (2) add an aqueous solution of cationic etherification agent to alkalized guar bean endosperm slices, and react to prepare cationic Guar bean endosperm slices; (3) adding a phase transfer catalyst to the cationic intermediate, under the protection of protective gas, adding an alkoxy etherification agent, reacting, then cooling down to room temperature, and adjusting the pH value of the material to weak acid to Weakly alkaline to produce hydroxypropyl cationic guar bean endosperm slices; (4) coarsely crushing, drying, pulverizing, sieving and homogenizing to produce hydroxypropyl cationic guar gum finished product. The preparation method of the invention does not use organic solvents, the cost is greatly reduced, the production process is safe and environment-friendly, and the synthesis process is simple.

Description

A kind of preparation method and application of hydroxypropyl cationic guar gum and its water medium semi-dry method

technical field

The invention belongs to the field of retention and drainage aids for paper pulp, in particular to a method of using guar gum as a raw material to prepare wood pulp and straw pulp systems and a retention and drainage aid in the papermaking process of reconstituted tobacco leaves, in particular to a hydroxyl Propyl cationic guar gum and its water medium semi-dry preparation method and application.

Background technique

At present, modified starch and cationic polyacrylamide are generally used as retention and drainage aids in the paper industry, but domestic starch raw materials come from different sources, there are many types, and the proportions of amylose and amylopectin are different, which seriously affects the quality of its modified products. Stability limits its popularization and application. Larger domestic paper mills have to choose wet-end additives produced by large foreign companies, resulting in increased paper costs. On the other hand, cationic polyacrylamide is not easy to biodegrade, and the residual monomer has certain toxicity, which limits its application in household paper and high-grade paper. Moreover, the reuse of white water containing cationic polyacrylamide will cause the enrichment of positive charges and the flocculation of fibers, which will affect the evenness of the paper and the stability of the papermaking system.

Guar gum is a natural galactomannan gum extracted from the endosperm of guar seeds produced in Yunnan, Xinjiang, India and other places. The main chain of guar gum is composed of mannose as a unit, and the side chain is composed of a single galactose. Its molecular structure similar to cellulose determines its natural compatibility with cellulose. Guar gum is used in the paper industry. While improving the retention and drainage effects of paper fine fibers and fillers, it does not affect the evenness of paper, thereby not reducing its strength performance. The natural plant seed source and excellent biodegradability of guar gum alleviate the environmental pollution problem of the paper industry, which is in line with the concept of clean production and environmental friendliness.

Although guar gum has good water solubility and thickening properties, it often has the following disadvantages: it cannot quickly swell and hydrate, and its dissolution rate is slow; its thickening ability is poor, and its content of water insolubles is high. These shortcomings greatly limit the application of guar gum, and it is necessary to change its physical and chemical properties through chemical modification methods so that it can be widely used. Each monosaccharide of guar gum has an average of three active hydroxyl groups. Under certain conditions, these three active hydroxyl groups can undergo etherification, esterification or oxidation reactions to prepare various ethers, ester derivatives and oxides.

At present, the modification reaction of manufacturers at home and abroad is carried out for rubber powder. First, the endosperm slices are hydrated and crushed into rubber powder, then modified in ethanol or isopropanol solution, and finally crushed again to obtain modified rubber. Sexual guar gum products. This process belongs to the two-step solvent method, and the process route is complicated. In the two steps of modification, chemical solvents such as ethanol and isopropanol are used in the two processes of hydration and crushing, and the product substitution degree is low.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a kind of hydroxypropyl cationic guar gum and its water medium semi-dry preparation method and application. The preparation method of the present invention does not use organic solvents, the cost is greatly reduced, and the production process is safe and environmentally friendly; the synthesis process is simple, the intermediate product does not need to be separated and purified, and subsequent reactions can be directly carried out; the reaction heat is fully utilized in the synthesis process, reducing energy consumption, and the prepared Hydroxypropyl cationic guar gum has high transparency, suitable hydroxypropyl substitution degree and cationic substitution degree, and low water-insoluble content.

For reaching above-mentioned purpose, the present invention adopts following technical means:

A kind of preparation method of hydroxypropyl cationic guar gum water medium semi-dry method, comprises the steps:

(1) Hydration and alkalization: the guar bean endosperm slices are added to hot water, under the protection of protective gas, an alkalizing agent aqueous solution is added, soaked for alkalization, and the alkalized guar bean endosperm slices are obtained;

(2) Cationic reaction: adding an aqueous solution of cationic etherifying agent to the alkalized guar bean endosperm sheet prepared in the step (1), reacting to prepare the cationic guar bean endosperm sheet;

(3) Hydroxypropylation reaction: the phase transfer catalyst is added to the cationic guar bean endosperm sheet obtained in step (2), under the protection of protective gas, an alkoxy etherification agent is added for reaction, and then cooled to room temperature , and adjust the pH value of the material to 6-10 to prepare hydroxypropyl cationic guar bean endosperm slices;

(4) The hydroxypropyl cationic guar bean endosperm slices prepared in step (3) are coarsely crushed, dried, pulverized, sieved and homogenized to obtain the finished product of hydroxypropyl cationic guar gum.

In the present invention, the hydroxypropyl group in the prepared hydroxypropyl cationic guar gum molecule endows it with remarkable rapid hydration, dissolution and swelling characteristics through the above specific steps, making it suitable for addition and use in the form of dry powder or slurry. It has a functional group similar to the fiber structure, showing good adhesion and reducing powder and hair loss on the paper surface; excellent dye and filler retention performance, reducing filler loss; reducing beating degree, and can correct and arrange Straighten messy and disordered long and short fibers, improve the stability of the wet end, and improve the physical and chemical indicators of the paper.

The basicizing agent, cationic etherifying agent, phase transfer catalyst and alkoxy etherification agent used in the above steps can be the general alkalizing agent, cationic etherification agent, phase transfer catalyst and alkoxy etherification in this type of technology agent.

As a preference, in the preparation method of the present invention, the alkalizing agent described in step (1) is any one or a mixture of at least two of sodium hydroxide, potassium hydroxide, sodium carbonate or sodium bicarbonate.

Preferably, in terms of parts by weight, relative to 100 parts of guar endosperm slices, the amount of hot water in step (1) is 50 to 300 parts, such as 70 parts, 90 parts, 120 parts, 150 parts, 190 parts parts, 210 parts, 240 parts, 270 parts, 295 parts, etc., the amount of alkalizing agent is 0.5 to 30 parts, such as 0.8 parts, 1.5 parts, 3 parts, 6 parts, 11 parts, 16 parts, 21 parts, 26 parts parts, 29 parts, etc., preferably the amount of hot water is 100-160 parts, and the amount of alkalizing agent is 1-15 parts.

In the present invention, the temperature of the hot water in step (1) is 60-70°C, such as 60°C, 63°C, 65°C, 68°C or 70°C.

Preferably, the mass concentration of the alkalizing agent aqueous solution is 10% to 80%, such as 14%, 18%, 25%, 30%, 36%, 41%, 48%, 55%, 61%, 70% , 75%, etc., preferably 20% to 50%.

Preferably, the soaking alkalization time is more than 0.05h, such as 0.08h, 0.15h, 0.22h, 0.3h, 0.45h, 0.6h, 0.8h, etc., preferably 0.1-0.5h.

As preferably, in the preparation method of the present invention, the cationic etherifying agent described in step (2) is 3-chloro-2-hydroxypropyltrimethylammonium chloride, pyridine hydrochloride, quinoline hydrochloride or Any one or a mixture of at least two of 2,3-epoxypropyltrimethylammonium chloride.

Preferably, in terms of parts by weight, relative to 100 parts of guar bean endosperm slices described in step (1), the amount of the cationic etherifying agent aqueous solution in step (2) is 0.5 to 30 parts, such as 0.7 parts, 0.9 parts parts, 1.5 parts, 3 parts, 6 parts, 9 parts, 12 parts, 15 parts, 18 parts, etc., preferably 1 to 20 parts.

Preferably, the mass concentration of the cationic etherifying agent aqueous solution is 50%-90%, 52%, 55%, 59%, 65%, 71%, 76%, 80%, 85%, etc., preferably 70%.

Preferably, the reaction temperature is 40-90°C, 42°C, 46°C, 50°C, 54°C, 58°C, 62°C, 69°C, 72°C, 76°C, 84°C, 88°C, etc., preferably 55-75°C; the reaction time is 1-10 hours, such as 1.5 hours, 3 hours, 6 hours, 9 hours, etc., preferably 2-4 hours.

Preferably, in the preparation method of the present invention, the phase transfer catalyst described in step (3) is tetramethylammonium bromide and/or cetylbenzyldimethylammonium chloride.

Preferably, the alkoxy etherifying agent in step (3) is any one or a mixture of at least two of ethylene oxide, propylene oxide, butylene oxide, and epichlorohydrin.

Preferably, in parts by weight, relative to 100 parts of guar endosperm slices described in step (1), the amount of the phase transfer catalyst in step (3) is 0 to 15 parts but excluding 0, for example 0.2 parts , 0.7 parts, 0.9 parts, 1.5 parts, 3 parts, 6 parts, 9 parts, 12 parts, 14 parts, etc., preferably 0 to 10 parts, the amount of the alkoxy etherifying agent is 0.5 to 25 parts, for example 0.7 parts, 0.9 parts, 1.5 parts, 3 parts, 6 parts, 9 parts, 12 parts, 15 parts, 18 parts, 23 parts, etc., Preferably it is 1-18 parts.

Preferably, the reaction time is more than 0.5 h, such as 0.7 h, 1.2 h, 1.5 h, 2.0 h, 2.5 h, etc., preferably 1-3 h.

Preferably, the substance used to adjust the pH value of the material is an acidic substance, preferably one or a mixture of at least two of hydrochloric acid, acetic acid, boric acid, and citric acid.

In the present invention, step (3) adjusts the pH value of the material to 6-10, such as 6.2, 6.4, 6.6, 7.1, 7.4, 7.7, 8, 8.3, 8.5, 9, 9.4, 9.8, etc., preferably, adjusting The pH value of the material is 6-8, more preferably 6.5-7.5.

Preferably, the protective gas in step (1) and step (3) is nitrogen or argon.

As preferably, the preparation method of the present invention comprises the following steps:

(1) Hydration and alkalization: In parts by weight, 100 parts of the cleaned guar endosperm slices are added to 100 to 160 parts of hot water, and under the protection of nitrogen, the alkalinization is carried out at a concentration of 20% to 50%. 1 to 15 parts of aqueous solution, soaked and alkalized for 0.1 to 0.5 hours to obtain alkalized guar bean endosperm slices;

(2) Cationic reaction: In parts by weight, 1 to 20 parts of concentration of 70% cationic etherifying agent aqueous solution is added to the alkalized guar bean endosperm sheet prepared in step (1), at a temperature of 55 to Under the condition of 75°C, react for 2 to 4 hours to prepare cationic guar bean endosperm slices;

(3) Hydroxypropylation reaction: in parts by weight, 0 to 10 parts of phase transfer catalysts are added to cationic guar bean endosperm slices, and under nitrogen protection, 1 to 18 parts of alkoxy etherification agents are added to react Exothermic to make the temperature of the material rise spontaneously to 50-75°C, react for 1-3 hours, then cool down to room temperature, and adjust the pH value of the material to 6.5-7.5 to prepare hydroxypropyl cationic guar endosperm slices;

(4) Crushing, drying, pulverizing, sieving and homogenizing the hydroxypropyl cationic guar endosperm slices prepared in step (3) to obtain the finished product of hydroxypropyl cationic guar gum.

In another aspect, the present invention provides hydroxypropyl cationic guar gum prepared by the above-mentioned preparation method.

The hydroxypropyl cationic guar gum molecule prepared by the invention not only has quaternary ammonium cations, but also grafts non-ionic hydroxypropyl groups. The cationic character combined with moderately controlled relative molecular mass makes the product of the present invention more effective than other retention aids in solving paper stock forming and shearing problems. It has a similar plant fiber cell structure, so it has a good affinity for the fiber; it can quickly adsorb on the fiber surface, reduce and neutralize the charge on the fiber surface, make the slurry potential close to the equipotential, reduce the inter-particle and fiber The mutual repulsion between them, and arrange and combine the disordered fibers into a neat three-dimensional network bridging structure.

The hydroxypropyl cationic guar gum prepared by the invention can quickly dissolve into a clear solution when it meets water at room temperature, and compared with modified starch chemicals, it does not require high-temperature gelatinization, is simple to operate, and is beneficial to reducing energy consumption and equipment investment; Compared with guar bean collagen powder, the anti-biodegradation ability of the product of the present invention is greatly improved. The aqueous solution is not corrupted or degraded after being placed at room temperature for a week, and the retention and drainage effect is not affected, but the starch-based retention and drainage agent must be prepared on the same day. use, otherwise performance is not guaranteed. The dosage can be adjusted according to the different components of the pulp, the beating degree and the addition of other additives, so as to exert a synergistic effect and expand the scope of applicable paper types of the product of the present invention, such as paper-making tobacco sheet and high-grade cigarette paper.

In another aspect, the present invention provides the use of the hydroxypropyl cationic guar gum as described above as a retention and drainage aid for pulp.

Preferably, the dosage of the hydroxypropyl cationic guar gum is 0.1%-0.5% of the paper mass, such as 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.4% or 0.5%.

The hydroxypropyl cationic guar gum of the present invention can be used as a retention and drainage aid for paper pulp, which can improve drainage, easily increase papermaking speed, and improve overall production efficiency; it can separate anionic impurities, improve retention, and improve Purification degree of white water system; helps to increase the dehydration pressure of the press and shorten the baking time; has a dispersing effect on the fibers, makes the fibers evenly distributed, and improves the strength of the paper; enhances the dyeing and light stability of the paper; does not aggregate and deposit in white water, and improves the stability of the wet end performance and reduce waste water discharge.

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

The present invention is characterized in that the hydroxypropyl cationic guar gum is prepared by the water-medium semi-dry method without using an organic solvent, the cost is greatly reduced, and the production process is safe and environmentally friendly; the synthesis process is simple, the intermediate product does not need to be separated and purified, and the follow-up reaction can be directly carried out ; During the synthesis process, the heat of reaction is fully utilized to reduce energy consumption.

The hydroxypropyl cationic guar gum prepared by the present invention has high transparency, its hydroxypropyl substitution degree is 0.05 to 0.30, its cationic substitution degree is 0.05 to 0.10, the content of water insoluble matter is low, and it can be quickly dissolved in water at room temperature. The clarified solution does not require high-temperature gelatinization, and is easy to operate, which is beneficial to reduce energy consumption and equipment investment. The aqueous solution will not be corrupted or degraded after being placed at room temperature for a week.

The hydroxypropyl cationic guar gum prepared by the invention can be used as a retention and drainage aid for pulp, which can improve drainage, easily increase papermaking speed, and improve overall production efficiency; it can separate anionic impurities and improve retention. , improve the purification degree of white water system; help to increase the dehydration pressure of the press and shorten the baking time; have a dispersing effect on the fibers, make the fibers evenly distributed, improve the paper strength, strengthen the dyeing and light stability of the paper, and improve the water filtration speed of the paper machine wire. Effective control, improve retention rate, has broad application prospects.

detailed description

For better illustrating the present invention, facilitate understanding technical scheme of the present invention, typical but non-limiting embodiment of the present invention is as follows:

Example 1

(1) Add 100kg successively to the kneader through the cleared guar bean endosperm sheet and 110kg hot water, under the condition of evacuating and filling with nitrogen, then add 5kg of concentration 40% sodium hydroxide aqueous solution, soak and alkalize for 0.5h;

(2) Add 15kg of 70% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, and react for 1.5h at a temperature of 55°C;

(3) Add 2.5kg of tetramethylammonium bromide, and add 12kg of propylene oxide under the condition of evacuating and filling with nitrogen. The exothermic reaction makes the temperature of the material rise to 65°C spontaneously, react for 1h, then cool down to room temperature, and adjust with acetic acid The pH value of the material reaches 7.0, and the hydroxypropyl cationic guar endosperm slices are obtained;

(4) After coarse crushing, drying, crushing, screening, homogenization and packaging, the finished product of hydroxypropyl cationic guar gum is obtained.

After testing, the hydroxypropyl substitution degree in the product is 0.25, the cationic substitution degree is 0.10, and the mass fraction of water-insoluble matter is 3%.

Example 2

(1) In the kneader, add 100kg successively through the cleared guar bean endosperm sheet and 120kg hot water, under the condition of evacuating and filling nitrogen, then add 4.5kg of concentration 40% sodium carbonate aqueous solution, soak and alkalize for 0.4h;

(2) Add 10kg of 70% 3-chloro-2-hydroxypropyltrimethylammonium chloride aqueous solution, and react for 1.5h at a temperature of 50°C;

(3) Add 2.5kg of cetylbenzyldimethylammonium chloride, and add 18kg of ethylene oxide under the condition of evacuating and filling with nitrogen. The exothermic reaction makes the temperature of the material rise to 68°C spontaneously, react for 1h, and then Cool down to room temperature, and adjust the pH value of the material to 7.5 with citric acid to prepare hydroxypropyl cationic guar endosperm slices;

(4) After coarse crushing, drying, crushing, screening, homogenization and packaging, the finished product of hydroxypropyl cationic guar gum is obtained.

After testing, the hydroxypropyl substitution degree in the product is 0.30, the cationic substitution degree is 0.08, and the mass fraction of water-insoluble matter is 2%.

Example 3

(1) Add 100kg successively to the kneader through cleaned melon endosperm slices and 140kg hot water, and then add 3.8kg of concentration 40% potassium hydroxide aqueous solution, soak and alkalize for 0.3h under the condition of evacuating and filling with nitrogen;

(2) Add 12 kg of 70% 2,3-epoxypropyltrimethylammonium chloride aqueous solution, and react for 1.2 hours at a temperature of 45°C;

(3) Add 2.5kg of cetylbenzyldimethylammonium chloride, and add 16kg of epichlorohydrin under the condition of evacuating and filling with nitrogen. The exothermic reaction makes the temperature of the material rise to 60°C spontaneously, and react for 1.2h. Then the temperature was lowered to room temperature, and the pH value of the material was adjusted to 7.3 with citric acid to obtain hydroxypropyl cationic guar bean endosperm slices;

(4) After coarse crushing, drying, crushing, screening, homogenization and packaging, the finished product of hydroxypropyl cationic guar gum is obtained.

After testing, the hydroxypropyl substitution degree in the product is 0.15, the cationic substitution degree is 0.10, and the mass fraction of water-insoluble matter is 4%.

Example 4

(1) Add 100kg successively to the kneader through cleaned melon endosperm slices and 50kg hot water, and then add 0.5kg of a concentration of 80% potassium hydroxide aqueous solution, soak and alkalize for 0.05h under the condition of evacuating and filling with nitrogen;

(2) Add 30 kg of 90% glycidyltrimethylammonium chloride aqueous solution, and react for 1 hour at a temperature of 95°C;

(3) Add 1 kg of pyridine hydrochloride, and add 25 kg of ethylene oxide under the condition of evacuating and filling nitrogen. The exothermic reaction makes the temperature of the material spontaneously rise to 70 ° C, react for 0.5 h, then cool down to room temperature, and use citric acid Adjust the pH value of the material to 6.0 to prepare hydroxypropyl cationic guar endosperm slices;

(4) After coarse crushing, drying, crushing, screening, homogenization and packaging, the finished product of hydroxypropyl cationic guar gum is obtained.

After testing, the hydroxypropyl substitution degree in the product is 0.05, the cationic substitution degree is 0.08, and the mass fraction of water-insoluble matter is 6%.

Example 5

(1) Add 100kg successively to the kneader through cleaned melon endosperm slices and 300kg hot water, and then add 30kg of concentration 10% potassium hydroxide aqueous solution, soak and alkalize for 1h under the condition of evacuating and nitrogen filling;

(2) Add 1 kg of 50% quinoline hydrochloride aqueous solution, and react for 10 hours at a temperature of 40°C;

(3) Add 15kg of tetramethylammonium bromide, and add 0.5kg of butylene oxide under the condition of evacuation and nitrogen filling. The exothermic reaction makes the temperature of the material rise to 75°C spontaneously, react for 5h, then cool down to room temperature, and use lemon Adjust the pH value of the material to 8.0 with acid to obtain hydroxypropyl cationic guar endosperm slices;

(4) After coarse crushing, drying, crushing, screening, homogenization and packaging, the finished product of hydroxypropyl cationic guar gum is obtained.

After testing, the hydroxypropyl substitution degree in the product is 0.20, the cationic substitution degree is 0.05, and the mass fraction of water-insoluble matter is 2%.

Example 6

In the present embodiment, the hydroxypropyl cationic guar gum prepared in Examples 1-5 is used as a retention and drainage aid for pulp, and the method is as follows:

The hydroxypropyl cationic guar gum prepared in Examples 1-5 is used as an enhanced retention and drainage aid for cigarette paper, and the addition amount is about 0.1% to 0.5% of the paper (the hydroxypropyl cationic guar gum prepared in each embodiment The dosage of the base cationic guar gum is all set to 0%, 0.1%, 0.2%, 0.3%, 0.5%), and its mass fraction should not exceed 1% as far as possible when dissolving. After pre-dissolving, it can be added to the high-consistency stock tank after beating, which can effectively control the water filtration speed of the wire part of the paper machine, improve the retention rate, improve the running performance of the watermark roller, and improve the paper strength.

It mainly includes the following steps:

1) Powder storage: set up a storage tank with a certain volume, and set up an electronic scale under the storage tank, and accurately control the amount of powder added according to the total amount of liquid and the ratio requirements. An auger is installed in the storage tank, and a frequency regulator is used to control the motor at a certain frequency when feeding the powder, and the stirring is performed at a low speed to prevent the phenomenon that the powder cannot be fed due to bridging.

2) Powder supply: A frequency regulator is used to control the precision feeding screw at a certain frequency to achieve uniform and continuous feeding of rubber powder, and the outlet is connected to the high-efficiency mixer through a plastic hose.

3) Water-powder mixing: clean water enters the high-efficiency mixer through the booster pump, and the rubber powder is sucked into the high-efficiency mixer by negative pressure to mix with water.

4) The glue formed by mixing is put into the preparation tank, stirred for 14-15 minutes, heated by steam for 2-3 minutes, so that the temperature of the glue reaches 34-35°C, and then poured into the liquid storage tank. The whole liquid preparation process takes 21-22 minutes.

5) The glue enters the liquid storage tank and continues to stir at a low speed of 50-60rpm. Under the control of the liquid level set by the automatic control system, it enters the use tank from the lower end through the screw liquid supply pump and continues to stir at a low speed of 50-60rpm.

6) The glue is transported by the frequency conversion screw liquid supply pump from the use tank, passes through the filter, and enters the pulp system. The flow range is 40-60min/L, which is determined according to paper weight, strength, air permeability, coefficient of variation and other indicators. On average, it takes about 2 hours for the glue to enter the pulp system from the time it enters the liquid storage tank.

The effect of using the hydroxypropyl cationic guar gum prepared in Examples 1-5 as a retention and drainage aid for pulp is shown in Table 1.

Table 1

As can be seen from the results in Table 1, the hydroxypropyl cationic guar gum of the present invention can effectively control the water filtration speed of the wire part of the paper machine and improve the retention rate.

The applicant declares that the present invention illustrates the hydroxypropyl cationic guar gum of the present invention and its water medium semi-dry method preparation method and application through the described examples, but the present invention is not limited to the above examples, that is, it does not mean It is said that the present invention must rely on above-mentioned embodiment and could implement. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims (10)

1. a kind of water-borne semidry method preparation method of hydroxypropyl cationic melon bean gum, it is characterised in that methods described includes as follows Step：

(1) hydrating alkalization：Melon beans albumen tablet is added in hot water, under protective gas protection, it is water-soluble to add basifier Liquid, immersion alkalization, alkalization melon beans albumen tablet is made；

(2) positive ionization：The cationic etherifying agent aqueous solution is added to obtained alkalization melon beans albumen tablet in step (1) In, reaction, cation melon beans albumen tablet is made；

(3) hydroxypropylation reacts：Phase transfer catalyst is added in the cation melon beans albumen tablet that step (2) obtains, Under protective gas protection, alkoxy etherifying agent is added, reaction, then cools to room temperature, and adjust material pH value to 6~10, Hydroxypropyl cationic melon beans albumen tablet is made；

(4) hydroxyl is made through coarse crushing, drying, crushing, screening, homogeneous in hydroxypropyl cationic melon beans albumen tablet made from step (3) Propyl group cation melon bean gum finished product.

2. preparation method according to claim 1, it is characterised in that basifier described in step (1) is sodium hydroxide, hydrogen In potassium oxide, sodium carbonate or sodium acid carbonate any one or at least two mixture；

Preferably, in terms of parts by weight, relative to 100 parts of melon beans albumen tablets, the dosage of step (1) described hot water for 50~ 300 parts, the dosage of basifier is 0.5~30 part, and preferably amount of hot water is 100~160 parts, and basifier dosage is 1~15 part.

3. preparation method according to claim 1 or 2, it is characterised in that the temperature of hot water described in step (1) be 60~ 70℃；

Preferably, the mass concentration of the basifier aqueous solution described in step (1) is 10%~80%, preferably 20%~50%；

Preferably, the time of the immersion alkalization is more than 0.05h, preferably 0.1~0.5h.

4. according to the preparation method described in claim any one of 1-3, it is characterised in that cation described in step (2) is etherified Agent is the chloro- 2- Hydroxyproyl Trimethyls ammonium chlorides of 3-, arsenic thiamine hydrochloride, quinoline hydrochloride or 2,3- epoxypropyl trimethylammonium chloride amine In any one or at least two mixture；

Preferably, in terms of parts by weight, relative to 100 parts of step (1) melon beans albumen tablets, step (2) described cation The dosage of the etherifying agent aqueous solution is 0.5~30 part, preferably 1~20 part；

Preferably, the mass concentration of the cationic etherifying agent aqueous solution is 50%~90%, preferably 70%.

5. according to the preparation method described in claim any one of 1-4, it is characterised in that the temperature reacted described in step (2) For 40~90 DEG C, preferably 55~75 DEG C；The time of reaction is 1~10h, preferably 2~4h.

6. according to the preparation method described in claim any one of 1-5, it is characterised in that phase transfer catalysis (PTC) described in step (3) Agent is 4 bromide and/or hexadecyl benzyl dimethly ammonium chloride；

Preferably, alkoxy etherifying agent described in step (3) is in oxirane, expoxy propane, epoxy butane, epoxychloropropane Any one or at least two mixture.

7. according to the preparation method described in claim any one of 1-6, it is characterised in that in terms of parts by weight, relative to 100 parts Step (1) the melon beans albumen tablet, the dosage of step (3) described phase transfer catalyst for 0~15 part but do not include 0, preferably For 1~10 part, the dosage of the alkoxy etherifying agent is 0.5~25 part, preferably 1~18 part；

Preferably, the time reacted described in step (3) is more than 0.5h, preferably 1~3h；

Preferably, material used in regulation material pH value is acidic materials, preferably hydrochloric acid, acetic acid, boric acid, lemon in step (1) One kind or at least two mixture in acid；

Preferably, material pH value is adjusted to 6~8, preferably 6.5~7.5；

Preferably, step (1) and step (3) described protective gas are nitrogen or argon gas.

8. according to the preparation method any one of claim 1-7, it is characterised in that comprise the following steps：

(1) hydrating alkalization：In terms of parts by weight, 100 parts of melon beans albumen tablets through cleaning are added to 100~160 parts of heat In water, under nitrogen protection, 1~15 part of 20%~50% basifier aqueous solution of concentration, immersion 0.1~0.5h of alkalization, system are added Must be alkalized melon beans albumen tablet；

(2) positive ionization：It is that the 70% cationic etherifying agent aqueous solution is added to by 1~20 part of concentration in terms of parts by weight In the obtained alkalization melon beans albumen tablet of step (1), under the conditions of temperature is 55~75 DEG C, 2~4h is reacted, cation melon is made Youngster's beans albumen tablet；

(3) hydroxypropylation reacts：In terms of parts by weight, 0~10 portion of phase transfer catalyst is added to cation melon beans endosperm Piece, under nitrogen protection, 1~18 portion of alkoxy etherifying agent is added, exothermic heat of reaction makes temperature of charge is spontaneous to be raised to 50~75 DEG C, instead 1~3h is answered, then cools to room temperature, and with material pH value is adjusted to 6.5~7.5, hydroxypropyl cationic melon beans endosperm is made Piece；

(4) hydroxypropyl cationic melon beans albumen tablet made from step (3) is made through coarse crushing, drying, crushing, screening, homogeneous Hydroxypropyl cationic melon bean gum finished product.

9. the hydroxypropyl cationic melon bean gum that the preparation method according to claim any one of 1-8 is prepared.

10. application of the hydroxypropyl cationic melon bean gum according to claim 9 as paper pulp retention and drainage aid agent.