阅读说明：本技术 一种松香施胶剂及其制备方法 (Rosin sizing agent and preparation method thereof ) 是由 卢志勇 栾星星 于 2021-08-26 设计创作，主要内容包括：本发明提供了一种松香施胶剂及其制备方法,其原料配方是包括重量份数的组分：阳离子松香胶20-40份；强化松香胶8-12份；改性滑石粉5-15份；环糊精10-20份；十六烷基三甲基氯化铵10-18份；聚甘油烷基醚3-6份；壳聚糖3-5份；3-氨基丙基三甲氧基硅烷2-5份。该发明的技术效果为：通过该配方及制备工艺制备的松香施胶剂附着率高,且具有较高抗油性以及稳定性。(The invention provides a rosin sizing agent and a preparation method thereof, wherein the raw material formula comprises the following components in parts by weight: 20-40 parts of cationic rosin size; 8-12 parts of reinforced rosin size; 5-15 parts of modified talcum powder; 10-20 parts of cyclodextrin; 10-18 parts of hexadecyl trimethyl ammonium chloride; 3-6 parts of polyglycerol alkyl ether; 3-5 parts of chitosan; 2-5 parts of 3-aminopropyltrimethoxysilane. The invention has the technical effects that: the rosin sizing agent prepared by the formula and the preparation process has high adhesion rate, high oil resistance and high stability.)

1. A rosin sizing agent, which is characterized in that: the raw material formula comprises the following components in parts by weight:

20-40 parts of cationic rosin size; 8-12 parts of reinforced rosin size; 5-15 parts of modified talcum powder; 10-20 parts of cyclodextrin; 10-18 parts of hexadecyl trimethyl ammonium chloride; 3-6 parts of polyglycerol alkyl ether; 3-5 parts of chitosan; 2-5 parts of 3-aminopropyltrimethoxysilane.

2. A rosin sizing agent according to claim 1, wherein: the raw material formula comprises the following components in parts by weight:

30-40 parts of cationic rosin size; 8-10 parts of reinforced rosin size; 5-10 parts of modified talcum powder; 15-20 parts of cyclodextrin; 10-15 parts of hexadecyl trimethyl ammonium chloride; 3-4 parts of polyglycerol alkyl ether; 3-5 parts of chitosan; 2-4 parts of 3-aminopropyltrimethoxysilane.

3. A sizing agent according to claim 1, characterised in that: the weight ratio of the hexadecyl trimethyl ammonium chloride to the polyglycerol alkyl ether is 3-4: 1.

4. a method for producing a rosin sizing agent according to any one of claims 1 to 3, wherein: the method comprises the following steps:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, and stirring for 10 minutes;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at the temperature of 50-70 ℃, and stirring until no precipitate is formed to obtain a rosin sizing agent;

a4, heating and melting the reinforced rosin size, adding an esterifying agent in batches, reacting for 1-5 hours at the reaction temperature of 70-120 ℃, and discharging to obtain a rosin-based surfactant;

a5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 1-4 hours, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 1-5 hours, and discharging to obtain the modified rosin sizing agent.

5. The method for producing a rosin sizing agent according to claim 4, wherein: in step a3, the modified talc is selected from talc modified with a surface modifier, which is a mixture of polyacrylic acid and sodium silicate.

6. The method for producing a rosin sizing agent according to claim 4 or 5, wherein: the weight ratio of the polyacrylic acid to the sodium silicate is as follows: 2-3:1.

7. The method for producing a rosin sizing agent according to any one of claims 4 to 6, wherein: in the step A4, the esterifying agent is added in batches, and the time interval of each time is 20-30 min.

8. The method for producing a rosin sizing agent according to claim 4, wherein: in the step A4, the reaction temperature is 80-100 ℃, and the reaction time is 1-2 h.

9. The method for producing a rosin sizing agent according to claim 4, wherein: and step A5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 1-2 hours, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 2-4 hours, and discharging to obtain the modified rosin sizing agent.

Technical Field

The invention belongs to the technical field of rosin size and preparation processes, and particularly relates to a rosin sizing agent and a preparation method thereof.

Background

Sizing agents are classified into two major types, rosin type and non-rosin type. Rosin sizing agent uses rosin as main body, mainly including rosin size, reinforced rosin size, paraffin rosin size and dispersed rosin size, etc. due to different glue-making processes and methods, rosin size is divided into brown rosin size, white rosin size and high-freeness rosin size. The non-rosin sizing agent mainly comprises paraffin latex, sodium stearate, polyvinyl alcohol, carboxymethyl cellulose, animal gum, casein, starch, synthetic gum and the like. Rosin sizing agents are mainly used for internal sizing, non-rosin sizing agents are mostly used for surface sizing, and paper or paperboard with special requirements also uses the non-rosin sizing agents as internal sizing agents.

Sizing refers to a method of treating paper or board. The purpose of sizing paper is to impart the paper with resistance to fluid penetration. Almost all papers, except a few specialty papers, require different degrees of sizing.

In the prior art, in the process of sizing, aluminum sulfate is often added in order to increase the adhesion effect of the sizing agent on paper, but the addition of aluminum sulfate is also easy to cause corrosion to papermaking equipment, generate dirt, foam and other influences, the domestic papermaking industry does a lot of work for realizing neutral and alkaline sizing, and the development of the variety of the sizing agent is greatly improved, but the problems of poor sizing performance, such as low adhesion rate, poor stability, poor water resistance and oil resistance, and the like still exist at present.

The invention is provided in view of the above.

Disclosure of Invention

The invention aims to provide a rosin sizing agent and a preparation method thereof, which aim to solve the problems in the prior art.

In order to achieve the purpose, the invention adopts the following technical means:

the rosin sizing agent comprises the following raw materials in parts by weight:

20-40 parts of cationic rosin size; 8-12 parts of reinforced rosin size; 5-15 parts of modified talcum powder; 10-20 parts of cyclodextrin; 10-18 parts of hexadecyl trimethyl ammonium chloride; 3-6 parts of polyglycerol alkyl ether; 3-5 parts of chitosan; 2-5 parts of propyl trimethoxy silane.

In some embodiments, a rosin sizing agent is prepared from a raw material formula comprising the following components in parts by weight:

30-40 parts of cationic rosin size; 8-10 parts of reinforced rosin size; 5-10 parts of modified talcum powder; 15-20 parts of cyclodextrin; 10-15 parts of hexadecyl trimethyl ammonium chloride; 3-4 parts of polyglycerol alkyl ether; 3-5 parts of chitosan; 2-4 parts of 3-aminopropyltrimethoxysilane.

In some embodiments, the weight ratio of cetyltrimethylammonium chloride to polyglycerol alkyl ether is 3-4: 1.

in some embodiments, the present invention also provides a method of preparing a rosin sizing agent, the method comprising the steps of:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, and stirring for 10 minutes;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at the temperature of 50-70 ℃, and stirring until no precipitate is formed to obtain a rosin sizing agent;

a4, heating and melting the reinforced rosin size, adding an esterifying agent in batches, reacting for 1-5 hours at the reaction temperature of 70-120 ℃, and discharging to obtain a rosin-based surfactant;

a5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 1-4 hours, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 1-5 hours, and discharging to obtain the modified rosin sizing agent.

In some embodiments, in step a3, the modified talc is selected from talc modified with a surface modifier which is a mixture of polyacrylic acid and sodium silicate.

In some embodiments, the weight ratio of polyacrylic acid to sodium silicate is: 2-3:1.

In some embodiments, in step a3, the step of modifying the talc powder with a surface modifier comprises: a. dissolving polyacrylic acid in an organic solvent to prepare a feed liquid 1; as feed solution 1; b. dissolving sodium silicate in water to obtain a feed liquid 2; c. placing talcum powder in a fluidized bed reactor, vacuumizing, and introducing nitrogen to keep talcum powder particles in a suspension state; d. and (3) starting a sample injection pump 2, introducing the feeding liquid 2 into the fluidized bed reactor, spraying for a period of time, starting the sample injection pump 1, introducing the feeding liquid 1 into the fluidized bed reactor, spraying the feeding liquid 1 and the feeding liquid 2 simultaneously, transferring into a drying device until the spraying is finished, and drying to obtain the modified talcum powder. The modified talcum powder prepared by the preparation process has better bonding force and better fluidity, and is beneficial to mixing with other fillers.

In some embodiments, the feed rate of feed liquid 2 is V2, the feed rate of feed liquid 1 is V1, and V2> V1.

In some embodiments, feed rate of feed liquid 2 is from 1.5 to 2.0g/min and feed rate of feed liquid 1 is from 3.5 to 4 g/min.

In some embodiments, the organic solvent is a low boiling point organic solvent.

In some embodiments, the low boiling organic solvent is any one of n-butanol, n-pentanol, n-hexanol, or n-octanol.

In some embodiments, in step A4, the esterification agent is added in portions, each time interval being 20 to 30 min.

In some embodiments, the esterification agent is a polyol.

In some embodiments, in the step A4, the reaction temperature is 80-100 ℃ and the reaction time is 1-2 h.

In some embodiments, in the step a5, the rosin sizing agent prepared in the step A3 is added into a heating kettle, the temperature is raised to 60-90 ℃, the stirring is carried out for 1-2 hours, then 3-aminopropyltrimethoxysilane and the rosin-based surfactant prepared in the step a4 are added, the stirring is continuously carried out for 2-4 hours, and the modified rosin sizing agent is obtained after discharging.

The invention has the beneficial effects that:

1. the cyclodextrin and the chitosan are added in the gluing process, so that the dryness of the rosin size after film coating can be improved, and the water resistance, the oil resistance and the stability can be improved.

2. According to the invention, aluminum sulfate is reduced in the sizing agent, modified talcum powder is added, lipophilicity is increased, rosin size is adsorbed on paper pulp fiber, and the adhesion performance of the rosin size on paper is further provided.

3. In the preparation process of the sizing agent, cationic surfactant cetyl trimethyl ammonium chloride and anionic surfactant polyglycerol alkyl ether are added as surfactants, and the cationic surfactant and the anionic surfactant are mixed to ensure that ions are tightly connected during mixing and stirring, so that strong interaction is easily generated between hydrocarbon chains, namely, the hydrophobic binding force between the hydrocarbon chains is enhanced, the repulsion tendency between ionic groups is greatly weakened by the chemical bond force, the surface activity is high, the agglomeration is avoided, and the dispersibility is improved.

4. According to the invention, 3-aminopropyl trimethoxy silane and rosin-based surfactant are added into rosin size, so that the compatibility of the rosin size with filler and polar resin is obviously improved. Meanwhile, the rosin sizing agent has coupling property, has the properties of low viscosity, high softening point and the like, has good thermal stability, low high-temperature volatility, excellent filler dispersibility, excellent external lubricity and strong internal lubrication effect, can improve the production efficiency of rosin sizing processing, and reduces the production cost.

Detailed Description

The present invention is described in detail below with reference to examples, but the following examples should not be construed as limiting the scope of the present invention.

Example 1

A rosin sizing agent and a preparation method thereof, wherein the raw material formula comprises the following components in parts by weight:

30 parts of cationic rosin size; 10 parts of reinforced rosin size; 10 parts of modified talcum powder; 15 parts of cyclodextrin; 15 parts of hexadecyl trimethyl ammonium chloride; 5 parts of polyglycerol alkyl ether; 4 parts of chitosan; 4 parts of 3-aminopropyltrimethoxysilane.

The preparation method comprises the following steps:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, stirring for 10 minutes at 50 ℃;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at 50 ℃, and stirring until no precipitate is formed to obtain a rosin sizing agent;

a4, heating and melting the reinforced rosin size, and adding trimethylolpropane in batches, wherein the time interval of each time is 20 min. Then reacting for 1h at the temperature of 80-100 ℃, and discharging to obtain a rosin-based surfactant;

a5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 2 hours, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 2 hours, and discharging to obtain the modified rosin sizing agent.

Wherein the modified talcum powder is selected from talcum powder modified by a surface modifier, and the weight ratio of the surface modifier to the talcum powder is as follows: 10:1, wherein the weight ratio of the surface modifier is as follows: 2:1 mixture of polyacrylic acid and sodium silicate. The preparation method of the modified talcum powder comprises the following steps: a. dissolving 10g of polyacrylic acid in 30ml of n-butanol to prepare a feed solution 1; as feed solution 1; b. 5g of sodium silicate was dissolved in 25ml of water as feed solution 2; c. placing talcum powder in a fluidized bed reactor, vacuumizing, and introducing nitrogen to keep talcum powder particles in a suspension state; d. firstly, feeding the feed liquid 2 into the fluidized bed reactor at the speed of 1.5g/min, spraying for a period of time, then feeding the feed liquid 1 into the fluidized bed reactor at the speed of 3.5g/min, and at the moment, simultaneously spraying the feed liquid 1 and the feed liquid 2 until the spraying is finished; and transferring the mixture into a drying device for drying treatment to obtain the modified talcum powder.

1g of the sizing agent prepared in the embodiment is used for sizing, and the adhesive rate of the sizing agent reaches 75%.

Example 2

A rosin sizing agent and a preparation method thereof, wherein the raw material formula comprises the following components in parts by weight:

35 parts of cationic rosin size; 12 parts of reinforced rosin size; 15 parts of modified talcum powder; 18 parts of cyclodextrin; 12 parts of hexadecyl trimethyl ammonium chloride; 4 parts of polyglycerol alkyl ether; 5 parts of chitosan; 5 parts of 3-aminopropyltrimethoxysilane.

The preparation method comprises the following steps:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, stirring for 10 minutes at 50 ℃;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at 70 ℃, and stirring until no precipitate is formed to obtain a rosin sizing agent;

a4, heating and melting the reinforced rosin size, and adding trimethylolpropane in batches, wherein the time interval of each time is 25 min. Then reacting for 2 hours at the temperature of 80-100 ℃, and discharging to obtain a rosin-based surfactant;

a5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 1.5 hours, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 3 hours, and discharging to obtain the modified rosin sizing agent.

Wherein the modified talcum powder is selected from talcum powder modified by a surface modifier, and the weight ratio of the surface modifier to the talcum powder is as follows: 12:1, wherein the weight ratio of the surface modifier is as follows: 2:1 mixture of polyacrylic acid and sodium silicate. The preparation method of the modified talcum powder comprises the following steps: a. dissolving 10g of polyacrylic acid in 30ml of n-butanol to prepare a feed solution 1; as feed solution 1; b. 5g of sodium silicate was dissolved in 25ml of water as feed solution 2; c. placing talcum powder in a fluidized bed reactor, vacuumizing, and introducing nitrogen to keep talcum powder particles in a suspension state; d. firstly, feeding the feed liquid 2 into the fluidized bed reactor at the speed of 2/min, spraying for a period of time, then feeding the feed liquid 1 into the fluidized bed reactor at the speed of 4g/min, and at the moment, simultaneously spraying the feed liquid 1 and the feed liquid 2 until the spraying is finished; and transferring the mixture into a drying device for drying treatment to obtain the modified talcum powder.

1g of the sizing agent prepared in the embodiment is used for sizing, and the adhesive rate of the sizing agent reaches 78%.

Example 3

A rosin sizing agent and a preparation method thereof, wherein the raw material formula comprises the following components in parts by weight:

40 parts of cationic rosin size; 12 parts of reinforced rosin size; 15 parts of modified talcum powder; 20 parts of cyclodextrin; 18 parts of hexadecyl trimethyl ammonium chloride; 6 parts of polyglycerol alkyl ether; 5 parts of chitosan; 5 parts of 3-aminopropyltrimethoxysilane.

The preparation method comprises the following steps:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, stirring for 10 minutes at 50 ℃;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at 70 ℃, and stirring until no precipitate is formed to obtain a rosin sizing agent;

a4, heating and melting the reinforced rosin size, and adding trimethylolpropane in batches, wherein the time interval of each time is 30 min. Then reacting for 2 hours at the temperature of 80-100 ℃, and discharging to obtain a rosin-based surfactant;

a5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 1h, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 4h, and discharging to obtain the modified rosin sizing agent.

Wherein the modified talcum powder is selected from talcum powder modified by a surface modifier, and the weight ratio of the surface modifier to the talcum powder is as follows: 10:1, wherein the weight ratio of the surface modifier is as follows: 3:1 mixture of polyacrylic acid and sodium silicate. The preparation method of the modified talcum powder comprises the following steps: a. dissolving 10g of polyacrylic acid in 30ml of n-butanol to prepare a feed solution 1; as feed solution 1; b. 5g of sodium silicate was dissolved in 25ml of water as feed solution 2; c. placing talcum powder in a fluidized bed reactor, vacuumizing, and introducing nitrogen to keep talcum powder particles in a suspension state; d. adding the feed liquid 2 into the fluidized bed reactor at the speed of 2/min, spraying for a period of time, and then adding the feed liquid 1 into the fluidized bed reactor at the speed of 3.5g/min, wherein the feed liquid 1 and the feed liquid 2 are sprayed simultaneously until the spraying is finished; and transferring the mixture into a drying device for drying treatment to obtain the modified talcum powder.

1g of the sizing agent prepared in the embodiment is used for sizing, and the adhesive rate of the sizing agent reaches 78%.

Example 4

A rosin sizing agent and a preparation method thereof, wherein the raw material formula comprises the following components in parts by weight:

25 parts of cationic rosin size; 8 parts of reinforced rosin size; 10 parts of modified talcum powder; 15 parts of cyclodextrin; 16 parts of hexadecyl trimethyl ammonium chloride; 4 parts of polyglycerol alkyl ether; 4 parts of chitosan; 4 parts of 3-aminopropyltrimethoxysilane.

The preparation method comprises the following steps:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, stirring for 10 minutes at 50 ℃;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at 70 ℃, and stirring until no precipitate is formed to obtain a rosin sizing agent;

a4, heating and melting the reinforced rosin size, and adding pentaerythritol in batches, wherein the time interval is 20min each time. Then reacting for 1.5h at the temperature of 80-100 ℃, and discharging to obtain a rosin-based surfactant;

a5, adding the rosin sizing agent prepared in the step A3 into a heating kettle, heating to 60-90 ℃, stirring for 2 hours, adding 3-aminopropyl trimethoxy silane and the rosin-based surfactant prepared in the step A4, continuously stirring for 3 hours, and discharging to obtain the modified rosin sizing agent.

Wherein the modified talcum powder is selected from talcum powder modified by a surface modifier, and the weight ratio of the surface modifier to the talcum powder is as follows: 15:1, wherein the weight ratio of the surface modifier is as follows: 2:1 mixture of polyacrylic acid and sodium silicate. The preparation method of the modified talcum powder comprises the following steps: a. dissolving 10g of polyacrylic acid in 30ml of n-butanol to prepare a feed solution 1; as feed solution 1; b. 5g of sodium silicate was dissolved in 25ml of water as feed solution 2; c. placing talcum powder in a fluidized bed reactor, vacuumizing, and introducing nitrogen to keep talcum powder particles in a suspension state; d. adding the feed liquid 2 into the fluidized bed reactor at the speed of 1.5/min, spraying for a period of time, adding the feed liquid 1 into the fluidized bed reactor at the speed of 3.5g/min, and spraying the feed liquid 1 and the feed liquid 2 at the same time until the spraying is finished; and transferring the mixture into a drying device for drying treatment to obtain the modified talcum powder.

1g of the sizing agent prepared in the embodiment is used for sizing, and the adhesive rate of the sizing agent reaches 79 percent.

Comparative example 1

A rosin sizing agent and a preparation method thereof are different from the rosin sizing agent in the embodiment 1 in that unmodified talcum powder is adopted, and other components and the preparation method are the same as the rosin sizing agent in the embodiment 1.

1g of the sizing agent prepared by the comparative example is used for sizing, and the adhesive rate of the sizing material reaches 57 percent.

Comparative example 2

40 parts of cationic rosin size; 12 parts of reinforced rosin size; 15 parts of modified talcum powder; 20 parts of cyclodextrin; 18 parts of hexadecyl trimethyl ammonium chloride; 2 parts of polyglycerol alkyl ether; 5 parts of chitosan; 5 parts of 3-aminopropyltrimethoxysilane.

The preparation method of the rosin sizing agent is the same as that of example 1.

1g of the sizing agent prepared by the comparative example is used for sizing, and the adhesive rate of the sizing material reaches 70 percent.

Comparative example 3

A rosin sizing agent and a preparation method thereof, wherein the raw material formula comprises the following components in parts by weight:

30 parts of cationic rosin size; 10 parts of modified talcum powder; 15 parts of cyclodextrin; 15 parts of hexadecyl trimethyl ammonium chloride; 5 parts of polyglycerol alkyl ether; 4 parts of chitosan.

The preparation method comprises the following steps:

a1, heating and melting cationic rosin, adding the cationic rosin into a cyclodextrin water solution, and stirring for 20 minutes;

a2, adding chitosan, stirring for 10 minutes at 50 ℃;

a3, adding modified talcum powder, hexadecyl trimethyl ammonium chloride and polyglycerol alkyl ether, stirring for 10 minutes at 50 ℃, and stirring until no precipitate is formed to obtain the rosin sizing agent.

Wherein the modified talcum powder is selected from talcum powder modified by a surface modifier, and the weight ratio of the surface modifier to the talcum powder is as follows: 10:1, wherein the weight ratio of the surface modifier is as follows: 2:1 mixture of polyacrylic acid and sodium silicate. The preparation method of the modified talcum powder comprises the following steps: a. dissolving 10g of polyacrylic acid in 30ml of n-butanol to prepare a feed solution 1; as feed solution 1; b. 5g of sodium silicate was dissolved in 25ml of water as feed solution 2; c. placing talcum powder in a fluidized bed reactor, vacuumizing, and introducing nitrogen to keep talcum powder particles in a suspension state; d. firstly, feeding the feed liquid 2 into the fluidized bed reactor at the speed of 1.5g/min, spraying for a period of time, then feeding the feed liquid 1 into the fluidized bed reactor at the speed of 3.5g/min, and at the moment, simultaneously spraying the feed liquid 1 and the feed liquid 2 until the spraying is finished; and transferring the mixture into a drying device for drying treatment to obtain the modified talcum powder.

1g of the sizing agent prepared by the comparative example is used for sizing, and the adhesive rate of the sizing material reaches 65 percent.

Test method

Making a paper sample: taking broad-leaved pulp with the mass fraction of 10%, respectively adding the sizing agents with the mass fraction of 1% in the examples 1-4 and the comparative examples 1-2, stirring uniformly, and then making paper to obtain paper with the basis weight of 35g/m²And drying, curing, and cooling to room temperature to obtain a papermaking sample.

1. Stability test

Whether or not delamination occurred was observed by centrifuging examples 1 to 4 and comparative examples 1 to 3 at 3500rpm for 1 hour in a centrifuge. The presence of a delamination is noted as present and the absence of a delamination is noted as absent.

2. Oil repellency

Tests and ratings were performed according to TAPPI-T559.

The test results are listed in table 1 below.

TABLE 1

Group of	Stability of	Oil repellency
			Example 1	Is free of	Stage 8
Example 2	Is free of	Stage 8
			Example 3	Is free of	Grade 9
Example 4	Is free of	Stage 8
			Comparative example 1	Is free of	Stage 7
Comparative example 2	Is free of	Stage 7
			Comparative example 3	Is free of	Grade 6

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention in any way, and any person skilled in the art can make any simple modification, equivalent replacement, and improvement on the above embodiment without departing from the technical spirit of the present invention, and still fall within the protection scope of the technical solution of the present invention.