阅读说明：本技术 一种用于造纸涂料的高固含低粘度水性润滑剂的制备方法 (Preparation method of high-solid-content low-viscosity water-based lubricant for papermaking coating ) 是由 施晓旦 沈安成 尹东华 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种高固含低粘度水性润滑剂的制备方法,所述高固含低粘度水性润滑剂是将组分硬脂酸甘油酯、异构醇聚氧乙烯醚、六偏磷酸钠、碱、分散剂和水混合后进行反应得到,所述分散剂选自木质素磺酸钠、亚甲基双萘磺酸钠、三聚氰胺-甲醛缩聚物、萘磺酸钠甲醛聚合物中的至少一种；按重量份数计,各组分重量含量为：硬脂酸甘油酯100份、异构醇聚氧乙烯醚18-50份、六偏磷酸钠8-30份、碱3-20份、分散剂0.5-5份、水100-200份。与现有的技术相比,本用于造纸涂料的高固含量水性润滑剂能改善涂料的流变性、固含量高、润滑效果好、粘度低,使用时无需稀释。(The invention discloses a preparation method of a high-solid-content low-viscosity aqueous lubricant, which is obtained by mixing and reacting the components of glyceryl stearate, isomeric alcohol polyoxyethylene ether, sodium hexametaphosphate, alkali, a dispersant and water, wherein the dispersant is selected from at least one of sodium lignosulfonate, sodium methylene dinaphthalene sulfonate, a melamine-formaldehyde polycondensate and a sodium naphthalenesulfonate formaldehyde polymer; the weight contents of the components are as follows: 100 parts of glyceryl stearate, 18-50 parts of isomeric alcohol polyoxyethylene ether, 8-30 parts of sodium hexametaphosphate, 3-20 parts of alkali, 0.5-5 parts of dispersing agent and 200 parts of water. Compared with the prior art, the high-solid-content water-based lubricant for the papermaking coating can improve the rheological property of the coating, has high solid content, good lubricating effect and low viscosity, and does not need to be diluted when in use.)

1. The preparation method of the high-solid-content low-viscosity aqueous lubricant is characterized in that the high-solid-content low-viscosity aqueous lubricant is obtained by mixing and reacting the components of glyceryl stearate, isomeric alcohol polyoxyethylene ether, sodium hexametaphosphate, alkali, a dispersing agent and water, wherein the dispersing agent is at least one selected from sodium lignosulfonate, sodium methylene dinaphthalene sulfonate, a melamine-formaldehyde polycondensate and a sodium naphthalenesulfonate-formaldehyde polymer; the weight contents of the components are as follows: 100 parts of glyceryl stearate, 18-50 parts of isomeric alcohol polyoxyethylene ether, 8-30 parts of sodium hexametaphosphate, 3-20 parts of alkali, 0.5-5 parts of dispersing agent and 200 parts of water.

2. The method according to claim 1, comprising in particular the steps of:

step 1, melting glyceryl stearate at 85-95 ℃ for later use;

step 2, uniformly mixing the isomeric alcohol polyoxyethylene ether, sodium hexametaphosphate, alkali and all water, completely dissolving to obtain a kettle bottom material, and heating to 85-95 ℃; adding the molten solution of the glyceryl stearate in the step 1 under high-speed stirring, and uniformly stirring;

step 3, adding a dispersing agent at 85-95 ℃, and uniformly stirring;

and 4, cooling to 20-40 ℃, and adjusting the pH value to 6-10 to prepare the water-based lubricant.

3. The method of claim 1, wherein the base is selected from at least one of diethanolamine, triethanolamine, triethylenediamine, sodium hydroxide, and potassium hydroxide.

4. The method of claim 1, wherein the dispersant is sodium lignosulfonate or sodium methylenedinaphthalene sulfonate.

5. The method of claim 1, wherein the weight content of each component is: 100 parts of glyceryl stearate, 18-22 parts of isomeric alcohol polyoxyethylene ether, 8-12 parts of sodium hexametaphosphate, 3-7 parts of alkali, 0.8-1.2 parts of dispersing agent and 130 parts of water 110-.

6. The method of claim 1, wherein the dispersing agent is added in step 3, and after stirring, the mixture is homogenized by a high-pressure homogenizer.

7. The method of claim 1, wherein the pressure of the high pressure homogenizer in step 3 is 20 to 30 Mpa.

8. A high-solid-content low-viscosity aqueous lubricant prepared by the method of any one of claims 1 to 7.

9. The high-solid low-viscosity aqueous lubricant according to claim 8, wherein the aqueous lubricant has a solids content of 40 to 60% by weight, a viscosity of 50 to 250 mPas at 25 ℃ and a pH of 7 to 10.

10. Use of the high solids, low viscosity aqueous lubricant of claim 9 in a coated paper papermaking coating.

Technical Field

The invention relates to the technical field of papermaking lubricants, in particular to a preparation method of a high-solid-content low-viscosity aqueous lubricant.

Background

The lubricant generally contains hydrophobic groups in chemical composition, and has a lubricating effect and a releasing effect. Lubrication is an action of reducing friction, wear, and frictional heat of a contact surface; the release effect is an action of reducing the adhesion of the contact surface. Specifically, the lubricant can prevent sheet dusting at calenders, drying cylinders, etc. in the production of coated paper and dusting of coated paper in printing operations; the release property of the coated paper on the cast coating cylinder is improved; imparting slip properties to the paper and reducing friction.

The lubricant is one of trace additives in the coating of the coated and processed paper, and has an important function of improving the coating structure of the coated paper. The lubricant has the functions of reducing the friction coefficient of a coating in the papermaking coating, improving the rheological property of the coating, further improving the flatness of the coating and improving the glossiness of finished paper. The current paper-making lubricant in the market mainly comprises high-grade fatty acid salts and high-molecular oxidized polyethylene, and also comprises wax emulsion and the like, and the high-grade fatty acid salts and the high-molecular oxidized polyethylene have the function of improving the friction coefficient of a coating.

Chinese patent CN106368057A discloses a preparation method of an aqueous lubricant, which is obtained by mixing and reacting the components of glyceryl stearate, isomeric alcohol polyoxyethylene ether, sodium hexametaphosphate, alkali, a bactericide and water. The aqueous lubricant obtained by the method is applied to papermaking coating, can improve the smoothness and the glossiness of paper, but has the problems of low solid content, high viscosity, poor rheological property and the like.

Disclosure of Invention

The invention aims to provide a preparation method of a high-solid-content low-viscosity water-based lubricant, so as to solve the defects in the background art.

The invention is realized by the following technical scheme:

a preparation method of a high-solid-content low-viscosity aqueous lubricant is provided, wherein the high-solid-content low-viscosity aqueous lubricant is obtained by mixing and reacting the components of glyceryl stearate, isomeric alcohol polyoxyethylene ether, sodium hexametaphosphate, alkali, a dispersing agent and water, wherein the dispersing agent is at least one selected from sodium lignosulfonate, methylene dinaphthalene sodium sulfonate, a melamine-formaldehyde polycondensate and a sodium naphthalenesulfonate formaldehyde polymer; the weight contents of the components are as follows: 100 parts of glyceryl stearate, 18-50 parts of isomeric alcohol polyoxyethylene ether, 8-30 parts of sodium hexametaphosphate, 3-20 parts of alkali, 0.5-5 parts of dispersing agent and 200 parts of water.

Further, the preparation method of the high-solid-content low-viscosity aqueous lubricant specifically comprises the following steps:

step 1, melting glyceryl stearate at 85-95 ℃ for later use;

step 2, uniformly mixing the isomeric alcohol polyoxyethylene ether, sodium hexametaphosphate, alkali and all water, completely dissolving to obtain a kettle bottom material, and heating to 85-95 ℃; adding the molten solution of the glyceryl stearate in the step 1 under high-speed stirring, and uniformly stirring;

step 3, adding a dispersing agent at 85-95 ℃, and uniformly stirring;

and 4, cooling to 20-40 ℃, and adjusting the pH value to 6-10 to prepare the water-based lubricant.

The alkali is at least one selected from diethanolamine, triethanolamine, triethylene diamine, sodium hydroxide and potassium hydroxide, preferably diethanolamine.

The dispersant is at least one selected from sodium lignosulfonate, sodium methylene dinaphthalene sulfonate, melamine-formaldehyde polycondensate and sodium naphthalene sulfonate-formaldehyde polymer, preferably sodium lignosulfonate or sodium methylene dinaphthalene sulfonate, and most preferably sodium lignosulfonate.

As a preferred technical scheme, the weight content of each component is as follows: 100 parts of glyceryl stearate, 18-22 parts of isomeric alcohol polyoxyethylene ether, 8-12 parts of sodium hexametaphosphate, 3-7 parts of alkali, 0.8-1.2 parts of dispersing agent and 130 parts of water 110-.

Further, the temperature in the step 2 is raised to 85-90 ℃, and the stirring speed is 1000-.

Preferably, the temperature in the step 2 is raised to 85 ℃, and the stirring speed is 1000-.

Further, adding a dispersing agent in the step 3, stirring uniformly, and homogenizing by using a high-pressure homogenizer. The pressure of the high-pressure homogenizer is 20-30MPa, preferably 20 MPa.

In a second aspect of the present invention, there is provided a high solid content low viscosity aqueous lubricant prepared by the above method.

Further, the high-solid low-viscosity aqueous lubricant has a solid content of 40-60% by weight, a viscosity of 50-250mPa s at 25 ℃ and a pH value of 7-10.

The water-based lubricant with high solid content and low viscosity for the papermaking coating prepared by the method can be directly added in the coating preparation process without dilution, and the addition amount is 0.2-0.5% of oven-dried pigment.

Compared with the prior art, the high-solid-content water-based lubricant for the papermaking coating and the preparation method thereof have the advantages that: reasonable design, simple process, low cost, high solid content, good lubricating effect, low viscosity and no need of dilution when in use, and can improve the rheological property of the coating.

Detailed Description

The invention is illustrated below by means of specific examples, without being restricted thereto. All the raw materials are conventional commercial products unless otherwise specified.

Example 1

Step 1, melting 100g of glyceryl stearate at 85 ℃ for later use;

step 2, adding 20g of isomeric alcohol polyoxyethylene ether, 10g of sodium hexametaphosphate, 5g of diethanolamine and 120g of deionized water into a reaction kettle, uniformly mixing, completely dissolving, and heating to 85 ℃; adding the melted liquid of the glyceryl stearate in the step 1 under high-speed stirring (1000r/min), and stirring for 15 minutes;

step 3, adding 1g of sodium lignosulphonate, continuing stirring for 10 minutes, homogenizing for one time at 20MPa by a high-pressure homogenizer, and filtering and discharging by using a 100-mesh screen;

and step 4, cooling to 25 ℃, wherein the weight solid content of the obtained aqueous lubricant is 53.10 wt%, the viscosity is 56mPa & s (measured by an NDJ-1 rotary viscometer), and the pH is 7.16 (measured by a PHS-3C precision pH meter).

Example 2

Step 1, melting 100g of glyceryl stearate at 95 ℃ for later use;

step 2, adding 50g of isomeric alcohol polyoxyethylene ether, 30g of sodium hexametaphosphate, 20g of sodium hydroxide and 150g of deionized water into a reaction kettle, uniformly mixing, completely dissolving, and heating to 95 ℃; adding the melted liquid of the glyceryl stearate in the step 1 under high-speed stirring (5000r/min), and stirring for 30 minutes;

step 3, adding 2g of sodium methylene dinaphthalene sulfonate, continuing stirring for 10 minutes, homogenizing once at 20MPa by a high-pressure homogenizer, and filtering and discharging by using a 100-mesh screen;

and step 4, cooling to 25 ℃, wherein the weight solid content of the obtained aqueous lubricant is 57.15 wt%, the viscosity is 121mPa & s (measured by an NDJ-1 rotary viscometer), and the pH is 8.64 (measured by a PHS-3C precision pH meter).

Example 3

Step 1, melting 100g of glyceryl stearate at 90 ℃ for later use.

Step 2, adding 40g of isomeric alcohol polyoxyethylene ether, 20g of sodium hexametaphosphate, 5g of potassium hydroxide, 5g of triethylene diamine and 115g of deionized water into a reaction kettle, uniformly mixing, completely dissolving, and heating to 90 ℃; the molten solution of the glyceryl stearate in the step 1 is added under high-speed stirring (3000r/min) and stirred for 20 minutes.

Step 3, adding 1g of sodium lignosulfonate and 2g of sodium methylenedinaphthalene sulfonate, continuing stirring for 30 minutes, homogenizing for one time at 20MPa by a high-pressure homogenizer, and filtering and discharging by using a 100-mesh screen;

and step 4, cooling to 25 ℃, wherein the weight solid content of the obtained aqueous lubricant is 59.14 wt%, the viscosity is 210mPa & s (measured by an NDJ-1 rotary viscometer), and the pH is 9.12 (measured by a PHS-3C precision pH meter).

Example 4

Step 1, melting 100g of glyceryl stearate at 92 ℃ for later use;

step 2, adding 30g of isomeric alcohol polyoxyethylene ether, 15g of sodium hexametaphosphate, 6g of triethanolamine, 7g of sodium hydroxide and 230g of deionized water into a reaction kettle, uniformly mixing, completely dissolving, and heating to 92 ℃; adding the melted liquid of the glyceryl stearate in the step 1 under high-speed stirring (4000r/min), and stirring for 10 minutes;

step 3, adding 1g of sodium lignosulfonate, 1g of sodium methylenedinaphthalenesulfonate and 1g of sodium naphthalenesulfonate formaldehyde polymer, continuing stirring for 20 minutes, homogenizing once at 20MPa by using a high-pressure homogenizer, and filtering and discharging by using a 100-mesh screen;

and step 4, cooling to 25 ℃, wherein the weight solid content of the obtained aqueous lubricant is 40.55 wt%, the viscosity is 111mPa & s (measured by an NDJ-1 rotary viscometer), and the pH is 9.55 (measured by a PHS-3C precise pH meter).

Comparative example 1

In step 3, no dispersant is added, and the mixture is homogenized by a high-pressure homogenizer, and is directly filtered and discharged by a 100-mesh screen, and the rest is the same as that in example 1.

Comparative example 2

In step 3, no dispersant is added, and the mixture is homogenized by a high-pressure homogenizer, and is directly filtered and discharged by a 100-mesh screen, and the rest is the same as that in example 2.

Comparative example 3

In step 3, no dispersant is added, and the mixture is homogenized by a high-pressure homogenizer, and is directly filtered and discharged by a 100-mesh screen, and the rest is the same as that in example 3.

Comparative example 4

In step 3, no dispersant is added, and the mixture is homogenized by a high-pressure homogenizer, and is directly filtered and discharged by a 100-mesh screen, and the rest is the same as that in example 4.

Comparative example 5

And 3, adding the dispersing agent in the step 3, then only adopting conventional mixing, not adopting a high-pressure homogenizer for homogenizing, and the rest is the same as the example 1.

Comparative example 6

The preparation process was the same as in example 1 except that the dispersant was replaced with a sodium polyacrylate dispersant.

Step 1, melting 100g of glyceryl stearate at 85 ℃ for later use;

step 2, adding 20g of isomeric alcohol polyoxyethylene ether, 10g of sodium hexametaphosphate, 5g of diethanolamine and 120g of deionized water into a reaction kettle, uniformly mixing, completely dissolving, and heating to 85 ℃; adding the melted liquid of the glyceryl stearate in the step 1 under high-speed stirring (1000r/min), and stirring for 15 minutes;

step 3, adding 1g of sodium polyacrylate, continuously stirring for 10 minutes, homogenizing for one time at 20MPa by a high-pressure homogenizer, and filtering and discharging by using a 100-mesh screen;

and step 4, cooling to 25 ℃, wherein the weight solid content of the obtained aqueous lubricant is 53.04 wt%, the viscosity is 495mPa & s (measured by an NDJ-1 rotary viscometer), and the pH is 8.76 (measured by a PHS-3C precision pH meter).

Comparative example 7

The procedure is as in example 1 except that the dispersant is replaced with sodium stearate.

Step 1, melting 100g of glyceryl stearate at 85 ℃ for later use;

step 2, adding 20g of isomeric alcohol polyoxyethylene ether, 10g of sodium hexametaphosphate, 5g of diethanolamine and 120g of deionized water into a reaction kettle, uniformly mixing, completely dissolving, and heating to 85 ℃; adding the melted liquid of the glyceryl stearate in the step 1 under high-speed stirring (1000r/min), and stirring for 15 minutes;

step 3, adding 1g of sodium stearate, continuously stirring for 10 minutes, homogenizing for one time at 20MPa by a high-pressure homogenizer, and filtering and discharging by using a 100-mesh screen;

and step 4, cooling to 25 ℃, wherein the weight solid content of the obtained aqueous lubricant is 53.15 wt%, the viscosity is 361mPa & s (measured by an NDJ-1 rotary viscometer), and the pH is 9.05 (measured by a PHS-3C precision pH meter).

The solids content and viscosity index of each example and comparative example are shown in table 1:

TABLE 1 sample Performance index

The experimental data show that the special dispersing agent is added in the synthesis of the lubricant, and after homogenization, the viscosity of the lubricant can be obviously reduced while the solid content of the lubricant is improved, so that the lubricant can be directly added without dilution in the process of applying the lubricant to papermaking coating, and the use convenience is improved.

Application examples

The lubricants prepared in examples 1-4 and comparative examples 1-7 above were formulated into coatings according to the following formulation:

95-grade heavy calcium carbonate 400g

Brazilian china clay 100g

50g of styrene-butadiene latex (dry weight)

Lubricant (dry weight) 2g

And (3) adjusting the weight solid content of the coating to 65% by using a proper amount of deionized water.

The experimental process comprises the following steps:

1) adding 95-grade heavy calcium carbonate, Brazilian china clay and a proper amount of deionized water into a high-speed dispersion machine, uniformly stirring, dispersing at a high speed for 20-30min until the fineness is qualified, adding latex and a lubricant at a low speed, uniformly stirring, discharging, and filtering by using a 100-mesh screen;

2) coatings formulated using examples 1-4 and comparative examples 1-4 were applied using a # 10 coating bar at 75g/m²Coating on the copperplate base paper with the coating weight of 15g/m²And is ready for use;

3) coating calendering conditions: the coated paper sample is taken and hard-calendered twice (0.3Mpa,85 ℃) by a small calender for standby.

The paper is subjected to coating performance test by adopting a national standard method:

and (3) judging standard: the larger the smoothness and gloss, the better the effect.

The results of the measurements are shown in Table 2:

TABLE 2 sample Performance index

From the above application results, it can be seen that: the lubricant prepared by the invention is applied to papermaking coating of coated paper, can obviously improve the smoothness and glossiness of the coated paper, and has good lubricating effect.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.