MODIFIED HYDROXYPROPYL METHYL CELLULOSE FOR ENHANCED CERAMIC TILE ADHESIVE AND PREPARATION METHOD AND APPLICATION THEREOF

Abstract

The present disclosure discloses a modified hydroxypropyl methyl cellulose for an enhanced ceramic tile adhesive, which is prepared from the following raw materials by mass percent: 54%-94% of hydroxypropyl methyl cellulose, 5%-40% of starch ether, 0.5%-3% of dispersing agent and 0.5%-3% of rheological agent, wherein the hydroxypropyl methyl cellulose is prepared from cellulose powder, granular caustic soda, liquid caustic soda, chloromethane and propylene oxide. A preparation method includes: (1) weighing the raw materials; (2) mixing the cellulose powder, the granular caustic soda, the liquid caustic soda, the chloromethane and the propylene oxide, carrying out etherification reaction, and then sequentially carrying out neutralization, washing, centrifugation, drying and crushing to obtain the hydroxypropyl methyl cellulose; and (3) mixing and stirring the hydroxypropyl methyl cellulose, the starch ether, the dispersing agent and the rheological agent to obtain the modified hydroxypropyl methyl cellulose.

Claims

1. A modified hydroxypropyl methyl cellulose for an enhanced ceramic tile adhesive, prepared from the following raw materials by mass percent: 54%-94% of hydroxypropyl methyl cellulose, 5%-40% of starch ether, 0.5%-3% of dispersing agent and 0.5%-3% of rheological agent, wherein the hydroxypropyl methyl cellulose is prepared from cellulose powder, granular caustic soda, liquid caustic soda, chloromethane and propylene oxide in a mass ratio of 1:(0.01-1.0):(0.02-2.1):(0.50-2.0):(0.01-1.5).

2. The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1, wherein the starch ether is any one or mixture of more of monobasic starch ether, binary starch ether and ternary starch ether.

3. The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1, wherein the dispersing agent is any one or mixture of more of polyacrylamide, polyvinyl alcohol and polyethylene oxide.

4. The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1, wherein the rheological agent is any one or mixture of more of guar gum, Arabic gum, carrageenan and xanthan gum.

5. The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1, wherein the cellulose powder is any one or mixture of more of cotton cellulose, wood cellulose, bamboo cellulose and straw cellulose; a polymerization degree of the cellulose powder is 500-8000; a particle size of the cellulose powder is 0.18-0.30 mm; and a bulk density of the cellulose powder is 150-200 g/L.

6. The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1, wherein the granular caustic soda is granular alkali metal hydroxide; the alkali metal hydroxide is sodium hydroxide and/or potassium hydroxide; a particle size of the granular caustic soda is 0.3-2.0 mm.

7. The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1, wherein the liquid caustic soda is an aqueous solution of alkali metal hydroxide; the alkali metal hydroxide is sodium hydroxide and/or potassium hydroxide; a mass concentration of the alkali metal hydroxide in the liquid caustic soda is 40%-60%.

8. A preparation method of the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive, specifically comprising the following steps: (1) weighing the raw materials according to a mass ratio of the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1; (2) mixing the cellulose powder, the granular caustic soda, the liquid caustic soda, the chloromethane and the propylene oxide, and carrying out etherification reaction, neutralization, washing, centrifugation, drying and crushing to obtain the hydroxypropyl methyl cellulose; and (3) mixing and stirring the hydroxypropyl methyl cellulose, the starch ether, the dispersing agent and the rheological agent to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

9. The preparation method of the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 8, wherein in the step (2), the etherification reaction comprises a first-stage etherification reaction and a second-stage etherification reaction; the first-stage etherification reaction is carried out under the pressure of 1.8-2.0 MPa and at the temperature of 55-65° C., and the reaction time is 0.5-1.5 h; in the step (2), the second-stage etherification reaction is carried out under the pressure of 2.3-2.5 MPa and at the temperature of 75-85° C., and the reaction time is 0.5-1.5 h; and in the step (3), the mixing and stirring rotation speed is 10-70 r/min, and the time is 40-60 min.

10. An application of the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive of claim 1 in preparing the enhanced ceramic tile adhesive, wherein a mass percent of the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive in the enhanced ceramic tile adhesive is 0.2%-0.5%.

Description

DESCRIPTION OF DRAWINGS

[0046] To more clearly describe the technical solutions in the embodiments of the present disclosure or in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be simply presented below. Apparently, the drawings in the following description are merely some embodiments of the present disclosure, and for those ordinary skilled in the art, other drawings can also be obtained according to the provided drawings without contributing creative labor.

[0047] FIG. 1 is a flow chart of a process of a modified hydroxypropyl methyl cellulose for an enhanced ceramic tile adhesive of the present disclosure.

DETAILED DESCRIPTION

[0048] Technical solutions in the embodiments of the present disclosure are described clearly and fully below. Apparently, the described embodiments are merely part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those ordinary skilled in the art without contributing creative labor will belong to the protection scope of the present disclosure.

[0049] In the following embodiments and comparative examples, the viscosity of hydroxypropyl methyl cellulose is viscosity (wet tackiness) of 2% aqueous solution measured by a B-type RVT viscosity meter at 20° C., and the viscosity of the starch ether is viscosity (dry tackiness) of 5% aqueous solution measured by a B-type LVT viscosity meter at 20° C.

Embodiment 1

[0050] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 74 kg of hydroxypropyl methyl cellulose, 20 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 3 kg of anionic polyacrylamide and 3 kg of guar gum.

[0051] The hydroxypropyl cellulose was prepared from 100 kg of cotton cellulose powder (the average polymerization degree was 2663, the particle size was 0.230 mm, and the bulk density was 175 g/L), 27 kg of granular sodium hydroxide (with particle size of 0.7 mm), 63 kg of sodium hydroxide aqueous solution (with mass concentration of 50%), 74 kg of chloromethane and 16 kg of propylene oxide.

[0052] A preparation method specifically includes the following steps.

[0053] (1) Raw materials were weighed according to the above mass.

[0054] (2) The cotton cellulose powder, granular sodium hydroxide and sodium hydroxide aqueous solution liquid caustic soda were added sequentially into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially, and temperature increased slowly to 60° C. for reaction for 0.5 h under the pressure of 1.9 MPa. Then the temperature increased slowly to 80° C. for reaction for 1.5 h under the pressure of 2.5 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out, the non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.5 MPa to 1.1 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 1.1 MPa to 0.25 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.25 MPa to −0.1 MPa). Acetic acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2 h at the rotation speed of 3000 r/min; then the drying was carried out for 2 h at 90° C. And the crushing was carried out to obtain the particle size of 0.15 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0055] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, anionic polyacrylamide and guar gum were added into a mixing machine for mixing and stirring for 50 min at a rotation speed of 50 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Embodiment 2

[0056] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 66 kg of hydroxypropyl methyl cellulose, 30 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 2 kg of nonionic polyacrylamide and 2 kg of Arabic gum.

[0057] The hydroxypropyl cellulose was prepared from 100 kg of wood cellulose powder (the average polymerization degree was 2880, the particle size was 0.230 mm, and the bulk density was 175 g/L), 34 kg of granular sodium hydroxide (with particle size of 0.7 mm), 51 kg of sodium hydroxide aqueous solution (with mass concentration of 50%), 79 kg of chloromethane and 12 kg of propylene oxide.

[0058] A preparation method specifically includes the following steps.

[0059] (1) Raw materials were weighed according to the above mass.

[0060] (2) The wood cellulose powder, granular sodium hydroxide and sodium hydroxide aqueous solution liquid caustic soda were added sequentially into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the air in the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially. And temperature increased slowly to 60° C. for reaction for 0.5 h under the pressure of 1.9 MPa. Then the temperature increased slowly to 80° C. for reaction for 1.5 h under the pressure of 2.5 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out, the non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.5 MPa to 1.1 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 1.1 MPa to 0.25 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.25 MPa to −0.1 MPa). Hydrochloric acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2.5 h at the rotation speed of 2800 r/min. Then the drying was carried out for 2.5 h at 80° C. And the crushing was carried out to obtain the particle size of 0.125 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0061] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, anionic polyacrylamide and guar gum were added into a mixing machine for mixing and stirring for 50 min at a rotation speed of 10 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Embodiment 3

[0062] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 71 kg of hydroxypropyl methyl cellulose, 25 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 2 kg of polyvinyl alcohol and 2 kg of carrageenan.

[0063] The hydroxypropyl cellulose was prepared from 20 kg of bamboo cellulose powder (the average polymerization degree was 1060, the particle size was 0.18 mm, and the bulk density was 150 g/L), 60 kg of wood cellulose powder (the average polymerization degree was 2530, the particle size was 0.18 mm, and the bulk density was 150 g/L), 20 kg of cotton cellulose powder (the average polymerization degree was 5010, the particle size was 0.18 mm, and the bulk density was 150 g/L), 65 kg of granular potassium hydroxide (with particle size of 0.3 mm), 100 kg of potassium hydroxide aqueous solution (with mass concentration of 40%), 167 kg of chloromethane and 65 kg of propylene oxide.

[0064] A preparation method specifically includes the following steps.

[0065] (1) Raw materials were weighed according to the above mass.

[0066] (2) The bamboo cellulose powder, the wood cellulose powder, the cotton cellulose powder, the granular potassium hydroxide and potassium hydroxide aqueous solution liquid caustic soda were added into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially. And temperature increased slowly to 60° C. for reaction for 1.5 h under the pressure of 2.0 MPa. Then the temperature increased slowly to 80° C. for reaction for 0.5 h under the pressure of 2.3 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out, the non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.3 MPa to 0.75 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 0.75 MPa to 0.1 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.1 MPa to −0.08 MPa). Hydrochloric acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 1.5 h at the rotation speed of 3500 r/min. Then the drying was carried out for 1.5 h at 80° C. And the crushing was carried out to obtain the particle size of 0.180 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0067] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, the polyvinyl alcohol and the carrageenan were added into a mixing machine for mixing and stirring for 45 min at a rotation speed of 70 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Embodiment 4

[0068] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 78 kg of hydroxypropyl methyl cellulose, 20 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 1 kg of polyoxyethylene and 1 kg of xanthan gum.

[0069] The hydroxypropyl cellulose was prepared from 70 kg of straw cellulose powder (the average polymerization degree was 500, the particle size was 0.30 mm, and the bulk density was 200 g/L), 30 kg of cotton cellulose powder (the average polymerization degree was 8000, the particle size was 0.30 mm, and the bulk density was 200 g/L), 50 kg of granular potassium hydroxide (with particle size of 2.0 mm), 80 kg of potassium hydroxide aqueous solution (with mass concentration of 60%), 156 kg of chloromethane and 120 kg of propylene oxide.

[0070] A preparation method specifically includes the following steps.

[0071] (1) Raw materials were weighed according to the above mass.

[0072] (2) The straw cellulose powder, the cotton cellulose powder, the granular potassium hydroxide and potassium hydroxide aqueous solution liquid caustic soda were added into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially. And temperature increased slowly to 60° C. for reaction for 1 h under the pressure of 1.9 MPa. Then the temperature increased slowly to 80° C. for reaction for 1 h under the pressure of 2.3 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out, the non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.3 MPa to 0.75 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 0.75 MPa to 0.1 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.1 MPa to −0.08 MPa). Hydrochloric acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2.5 h at the rotation speed of 3500 r/min. Then the drying was carried out for 2.5 h at 100° C. And the crushing was carried out to obtain the particle size of 0.180 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0073] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, the polyoxyethylene and the xanthan gum were added into a mixing machine for mixing and stirring for 45 min at a rotation speed of 70 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Comparative Example 1

[0074] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 74 kg of hydroxypropyl methyl cellulose, 20 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 3 kg of anionic polyacrylamide and 3 kg of guar gum.

[0075] The hydroxypropyl cellulose was prepared from 100 kg of cotton cellulose powder (the average polymerization degree was 2537, the particle size was 0.230 mm, and the bulk density was 175 g/L), 18 kg of granular sodium hydroxide (with particle size of 0.7 mm), 41 kg of sodium hydroxide aqueous solution (with mass concentration of 50%), 57 kg of chloromethane and 5 kg of propylene oxide.

[0076] A preparation method specifically includes the following steps.

[0077] (1) Raw materials were weighed according to the above mass.

[0078] (2) The cotton cellulose powder, granular sodium hydroxide and sodium hydroxide aqueous solution liquid caustic soda were added into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the air in the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially. And temperature increased slowly to 60° C. for reaction for 1 h under the pressure of 1.8 MPa. Then the temperature increased slowly to 80° C. for reaction for 1 h under the pressure of 2.3 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out. The non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.3 MPa to 1.1 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 1.1 MPa to 0.25 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.25 MPa to −0.1 MPa). Acetic acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with an amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2 h at a rotation speed of 3000 r/min. Then the drying was carried out for 2 h at 90° C. And the crushing was carried out to obtain the particle size of 0.15 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0079] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, anionic polyacrylamide and guar gum were added into a mixing machine for mixing and stirring for 60 min at a rotation speed of 50 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Comparative Example 2

[0080] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 66 kg of hydroxypropyl methyl cellulose, 30 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 2 kg of nonionic polyacrylamide and 2 kg of Arabic gum.

[0081] The hydroxypropyl cellulose was prepared from 100 kg of cotton cellulose powder (the average polymerization degree was 2739, the particle size was 0.230 mm, and the bulk density was 175 g/L), 18 kg of granular sodium hydroxide (with particle size of 0.7 mm), 50 kg of sodium hydroxide aqueous solution (with mass concentration of 50%), 60 kg of chloromethane and 8 kg of propylene oxide.

[0082] A preparation method specifically includes the following steps.

[0083] (1) Raw materials were weighed according to the above mass.

[0084] (2) The cotton cellulose powder, granular sodium hydroxide and sodium hydroxide aqueous solution liquid caustic soda were added into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially. And temperature increased slowly to 60° C. for reaction for 1 h under the pressure of 1.9 MPa. Then the temperature increased slowly to 80° C. for reaction for 1 h under the pressure of 2.3 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out. The non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.3 MPa to 0.75 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 0.75 MPa to 0.1 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.1 MPa to −0.08 MPa). Acetic acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2 h at the rotation speed of 3000 r/min. Then the drying was carried out for 2 h at 90° C. And the crushing was carried out to obtain the particle size of 0.15 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0085] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, nonionic polyacrylamide and Arabic gum were added into a mixing machine for mixing and stirring for 50 min at a rotation speed of 50 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Comparative Example 3

[0086] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 71 kg of hydroxypropyl methyl cellulose, 25 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 2 kg of polyvinyl alcohol and 2 kg of carrageenan.

[0087] The hydroxypropyl cellulose was prepared from 100 kg of cotton cellulose powder (the average polymerization degree was 2659, the particle size was 0.230 mm, and the bulk density was 175 g/L), 17 kg of granular sodium hydroxide (with particle size of 0.7 mm), 68 kg of sodium hydroxide aqueous solution (with mass concentration of 50%), 64 kg of chloromethane and 16 kg of propylene oxide.

[0088] A preparation method specifically includes the following steps.

[0089] (1) Raw materials were weighed according to the above mass.

[0090] (2) The cotton cellulose powder, granular sodium hydroxide and sodium hydroxide aqueous solution liquid caustic soda were added into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane were added sequentially. And temperature increased slowly to 60° C. for reaction for 1.5 h under the pressure of 1.9 MPa. Then the temperature increased slowly to 80° C. for reaction for 0.5 h under the pressure of 2.4 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out. The non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.4 MPa to 1.1 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 1.1 MPa to 0.25 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.25 MPa to −0.1 MPa). Acetic acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2 h at the rotation speed of 3000 r/min. Then the drying was carried out for 2 h at 90° C. And the crushing was carried out to obtain the particle size of 0.15 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0091] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, polyvinyl alcohol and carrageenan were added into a mixing machine for mixing and stirring for 50 min at a rotation speed of 50 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

Comparative Example 4

[0092] The modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive was prepared from the following raw materials by mass: 78 kg of hydroxypropyl methyl cellulose, 20 kg of hydroxypropyl starch (19.5% of hydroxypropyl, 5% of B-type LVT viscosity 1950 cp, and 7.5% of ash, produced by YITENG New Material Co., LTD in Shandong Province), 1 kg of polyoxyethylene and 1 kg of xanthan gum.

[0093] The hydroxypropyl cellulose was prepared from 100 kg of cotton cellulose powder (the average polymerization degree was 2452, the particle size was 0.230 mm, and the bulk density was 175 g/L), 43 kg of granular sodium hydroxide (with particle size of 0.7 mm), 65 kg of sodium hydroxide aqueous solution (with mass concentration of 50%), 96 kg of chloromethane and 43 kg of propylene oxide.

[0094] A preparation method specifically includes the following steps.

[0095] (1) Raw materials were weighed according to the above mass.

[0096] (2) The cotton cellulose powder, granular sodium hydroxide and sodium hydroxide aqueous solution liquid caustic soda were added into the reactor with a jacket and with pressure resistance of 3.0 MPa during the stirring. The reactor was emptied and was blown with nitrogen to remove oxygen, and the reactor was emptied again. The etherifying agents, that is, propylene oxide and chloromethane, were added sequentially. And temperature increased slowly to 60° C. for reaction for 1 h under the pressure of 1.9 MPa. Then the temperature increased slowly to 80° C. for reaction for 1 h under the pressure of 2.5 MPa. After the reaction was ended, temperature reduction and pressure relief were carried out. The non-reacted etherifying agents and byproducts dimethyl ether were recycled (the non-reacted etherifying agents were recycled through a three-stage condensation recycling process; at the first stage, the condensation recycling was carried out by directly relieving the pressure, and the pressure of the reactor decreased from 2.5 MPa to 1.1 MPa; at the second stage, the condensation recycling was carried out by compression, and the pressure of the reactor decreased from 1.1 MPa to 0.25 MPa; and at the third stage, the condensation recycling was carried out through vacuum and compression, and the pressure of the reactor decreased from 0.25 MPa to −0.1 MPa). Acetic acid was added into the reactor to regulate the pH value of the material to be 6.5. Then hot water at 90° C. with the amount being 8 times of the mass of the material was added into the reactor for washing. Centrifugation was carried out for 2 h at the rotation speed of 3000 r/min. Then the drying was carried out for 2 h at 90° C. And the crushing was carried out to obtain the particle size of 0.15 mm to obtain the hydroxypropyl methyl cellulose pure product.

[0097] (3) The hydroxypropyl methyl cellulose pure product prepared in the step (2), the hydroxypropyl starch, the polyoxyethylene and the xanthan gum were added into a mixing machine for mixing and stirring for 40 min at a rotation speed of 50 r/min to obtain the modified hydroxypropyl methyl cellulose for the enhanced ceramic tile adhesive.

[0098] Performance Test

[0099] 1. Methoxyl content, hydroxypropoxy content, 2% B-type RVT viscosity and ash content of the hydroxypropyl methyl cellulose pure product prepared in the step (2) in the embodiments 1-4 and comparative examples 1-4 were determined respectively, and the determination results were shown in Table 1.

TABLE-US-00001 TABLE 1 Performance test results of hydroxypropyl methyl cellulose pure product in embodiments 1-4 and comparative examples 1-4 2% B-type Methoxyl RVT Ash content Hydroxypropoxy Methoxyl + hydroxypropoxy viscosity content Item (%) content (%) content (%) (cp) (%) Embodiment 1 28.36 11.40 39.76 62362 4.5 Embodiment 2 30.52 9.04 39.56 73385 4.4 Embodiment 3 25.71 18.96 44.67 67973 4.5 Embodiment 4 22.52 25.02 47.54 63067 4.6 Comparative 20.81 4.47 25.28 62187 4.3 example 1 Comparative 22.83 6.59 29.42 73518 4.3 example 2 Comparative 24.66 12.16 36.82 68235 4.4 example 3 Comparative 31.23 26.50 57.73 63858 4.5 example 4

[0100] It may be seen from Table 1 that the hydroxypropyl methyl cellulose prepared in the embodiments 1-4 has higher total content of methoxyl and hydroxypropoxy, and the total content is ranged from 3800 to 480%, which is apparent higher than the total content (in a range of 250%-37%) of the methoxyl and hydroxypropoxy of the hydroxypropyl methyl cellulose prepared in the comparative examples 1-3, but far less than the total content (about 580%) of the methoxyl and hydroxypropoxy of the hydroxypropyl methyl cellulose prepared in the comparative example 4. The hydroxypropyl methyl cellulose prepared in the embodiment 2 has higher methoxyl content and lower hydroxypropoxy content, but the hydroxypropyl methyl cellulose prepared in the embodiment 4 has lower methoxyl content and higher hydroxypropoxy content. In addition, the embodiments 1-4 and the comparative examples 1-4 all have similar viscosity range and ash content.

[0101] 2. A small amount of modified hydroxypropyl methyl cellulose prepared in the embodiments 1-4 and comparative examples 1-4 was measured respectively for preparing the enhanced ceramic tile adhesive. A preparation method includes the following steps. The components were fed into the mixing machine for uniform mixing according to the components shown in Table 2, and water with the amount that was 250% of the total weight of the components was added. The stirring was carried out according to stirring equipment and stirring methods stipulated in the Standard JC/T547-2005 Adhesives For Ceramic Wall And Floor Tiles. And then the test on various performance (slip, tensile bonding strength, tensile bonding strength after soaking in water, tensile bonding strength after hot aging, tensile bonding strength after freezing-melting cycling and tensile bonding strength after standing in air for 30 min) was carried out. And the test results were shown in Table 3.

TABLE-US-00002 TABLE 2 Ceramic tile adhesive formulas of embodiments 1-4 and comparative examples 1-4 Butadiene- Water Modified 42.5 Fine Triple styrene reducing Calcium hydroxypropyl cement sand superphosphate rubber agent formate methyl Item (g) (g) (g) powder (g) (g) (g) cellulose (g) Embodiments 360 582 20 30 1 3 4 1-4 Comparative examples 1-4

TABLE-US-00003 TABLE 3 Performance test of ceramic tile adhesive of embodiments 1-4 and comparative examples 1-4 Tensile bonding Tensile bonding Tensile bonding strength after Tensile bonding strength after strength after Slip Tensile bonding soaking in strength after freezing-melting standing in air Item (mm) strength (MPa) water (MPa) hot aging (MPa) cycling (MPa) for 30 min (MPa) Index ≤0.5 ≥1.0 ≥0.5 Embodiment 1 0.2 1.508 1.132 1.316 1.268 1.081 Embodiment 2 0.1 1.632 1.243 1.409 1.348 1.139 Embodiment 3 0.1 1.581 1.197 1.368 1.302 1.113 Embodiment 4 0.1 1.553 1.161 1.337 1.278 1.027 Comparative 0.4 1.027 0.643 0.819 0.755 0.526 example 1 Comparative 0.3 1.116 0.739 0.907 0.843 0.627 example 2 Comparative 0.3 1.209 0.845 1.086 0.937 0.695 example 3 Comparative 0.2 1.015 0.631 0.854 0.762 0.432 example 4

[0102] It can be seen from Table 3 that the modified hydroxypropyl methyl cellulose prepared in the embodiments 1-4 of the present disclosure has an effect for improving the tensile bonding strength of the ceramic tile adhesive, wherein the tensile bonding strength and the tensile bonding strength after soaking in water, hot aging and freezing-melting cycling all can meet the requirement of the index ≥1.0 MPa, and meet the requirement of the ceramic tile adhesive that the slip resistance ≤0.5 mm and the tensile bonding strength after standing in air for 30 min≥0.5 MPa and all are better than the corresponding indexes of the comparative examples 1-4. The embodiment 2 is the optimum embodiment.

[0103] The above tests indicate that the present disclosure is simple in process and equipment, easy in operation, free from emission of waste water, waste gas and waste solids, and the modified hydroxypropyl methyl cellulose product prepared in the present disclosure is stable in quality, has a function of improving the tensile bonding strength of the ceramic tile adhesive, is applied to modern ceramic tiles with large sizes and large masses, and can improve the use safety of the ceramic tiles significantly, thereby meeting the requirements of the customers.

[0104] The above description of the disclosed embodiments enables those skilled in the art to realize or use the present disclosure. Many modifications made to these embodiments will be apparent to those skilled in the art. General principles defined herein can be realized in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.