High-whiteness titanium dioxide for papermaking and preparation method thereof

Abstract

The invention discloses a preparation method of high-whiteness titanium dioxide for papermaking, which comprises the following steps: carrying out heat treatment on titanium dioxide at 125-135 DEG C for 5-10 minutes, and then naturally cooling to room temperature; 4-6 parts of aluminum oxide and 2-3 parts of stearic acid are added into 8-12 parts of a sodium dodecyl benzene sulfonate solution, then 1-3 parts of a yttrium nitrate solution and 2-5 parts of a nano silicon dioxide agent are added, and the modified liquid is obtained after full blending. According to the high-whiteness titanium dioxide disclosed by the invention, heat treatment is firstly matched, the activity efficiency of the titanium dioxide is optimized, and the titanium dioxide is cooperatively improved through the cooperation of the modification liquid and the ball milling agent, so that the whiteness and retention rate of the obtained titanium dioxide can be cooperatively improved, and the aging resistance and stability of the product are improved.

Description

Technical Field

[0001] The invention relates to the technical field of titanium dioxide, and in particular to high-whiteness titanium dioxide for papermaking and a preparation method thereof. Background Art

[0002] Titanium dioxide is an important white pigment. 10-15% of the global titanium dioxide production is used in the papermaking industry. In the papermaking industry, titanium dioxide is the most expensive pigment and also one of the indispensable raw materials. Statistics in recent years show that the consumption of titanium dioxide in the papermaking industry ranks third in the total production of titanium dioxide. In the papermaking industry, pulp fiber accounts for the largest proportion, and pigments and fillers account for the second largest proportion.

[0003] The whiteness and retention rate of existing titanium dioxide for papermaking are difficult to coordinate and improve, and the product's aging resistance is poor, which further limits the use efficiency of the product. Based on this, the present invention further improves it. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a high-whiteness titanium dioxide for papermaking and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0005] The present invention solves the technical problem by adopting the following technical solution:

[0006] The present invention provides a method for preparing high-whiteness titanium dioxide for papermaking, comprising the following steps:

[0007] Step 1, heat treating titanium dioxide at 125-135° C. for 5-10 min, and then naturally cooling to room temperature;

[0008] Step 2, preparation of modified solution:

[0009] Add 4-6 parts of aluminum oxide and 2-3 parts of stearic acid to 8-12 parts of sodium dodecylbenzene sulfonate solution, and then add 1-3 parts of yttrium nitrate solution and 2-5 parts of nano-silica agent to mix well to obtain a modified solution;

[0010] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0011] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1000-1500 r / min for 1-2 hours. After the ball milling is completed, wash with water and dry to obtain high-whiteness titanium dioxide for papermaking.

[0012] Preferably, the mass fraction of the sodium dodecylbenzenesulfonate solution is 4-7%; the mass fraction of the yttrium nitrate solution is 2-5%.

[0013] Preferably, the immersion speed of the modified immersion stirring method is 550-750 r / min, and the stirring is 1-2 hours.

[0014] Preferably, the preparation method of the nano silicon dioxide agent is:

[0015] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution with a total amount of 10-15% of the nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0016] S02: Add 2-5 parts of carboxymethyl cellulose, 1-3 parts of nano silica sol, and 1-2 parts of silane coupling agent KH560 to 4-7 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution;

[0017] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0018] Preferably, the mass fraction of the sodium lignin sulfonate solution is 2-5%; and the pH value of the phosphate buffer solution is 5.5.

[0019] Preferably, the mixed ball milling treatment is carried out at a ball milling speed of 1000-1500 r / min, and the ball milling is carried out for 2 hours.

[0020] Preferably, the preparation method of the ball mill is:

[0021] S11: heat treating the nano-attapulgite at 250-260°C for 5-10 min, then heating to 355°C at a rate of 1-3°C / min, keeping the temperature for 2-5 min, and then cooling to 55°C at a rate of 2-5°C / min, and keeping the temperature;

[0022] S12: The nano-attapulgite and ball-milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball-milling agent is obtained.

[0023] Preferably, the ultrasonic power of the mixed ultrasonic treatment is 350-400W, and the ultrasonic time is 20-30min.

[0024] Preferably, the preparation method of the ball milling liquid is:

[0025] 4-7 parts of 5% chitosan solution, 1-3 parts of hydroxyapatite, 2-5 parts of sodium citrate and 2-4 parts of nano-silica sol are fully mixed to obtain a ball milling solution.

[0026] The invention also provides a method for preparing high-whiteness titanium dioxide for papermaking and high-whiteness titanium dioxide prepared by the method.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The high whiteness titanium dioxide powder of the present invention is firstly heat-treated to optimize the activity efficiency of the titanium dioxide powder, and then the titanium dioxide powder is coordinated and improved by coordinating the modified liquid with the ball mill. The obtained titanium dioxide powder can achieve coordinated improvement in whiteness and retention rate performance, and improve the stability of the product's anti-aging performance. The modified liquid is prepared by blending and coordinating aluminum oxide, stearic acid, sodium dodecylbenzene sulfonate solution, yttrium nitrate solution and nano-silicon dioxide agent. Through the coordination improvement between the raw materials, the nano-silicon dioxide modifier can be better coordinated with the titanium dioxide powder, and the performance coordination of the titanium dioxide powder is enhanced. The nano-silicon dioxide agent is improved by the method of the present invention and better coordinated with the titanium dioxide powder. At the same time, the ball mill adopts nano-attapulgite to be heat-treated at 250-260°C for 5-10 minutes, and then heated to 355°C at a rate of 1-3°C / min, and kept warm for 2-5 minutes, and then cooled to 55°C at a rate of 2-5°C / min, and kept warm. The interlayer spacing structure of nano-attapulgite is optimized to coordinate the synergistic effect of nano-attapulgite and titanium dioxide. A ball milling solution is obtained by fully blending 5% by mass chitosan solution, hydroxyapatite, sodium citrate and nano-silica sol. The ball milling solution is coordinated with nano-attapulgite to further enhance the aging resistance of the product as well as the coordinated improvement of whiteness and retention rate performance. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] A method for preparing high whiteness titanium dioxide for papermaking in this embodiment comprises the following steps:

[0031] Step 1, heat treating titanium dioxide at 125-135° C. for 5-10 min, and then naturally cooling to room temperature;

[0032] Step 2, preparation of modified solution:

[0033] Add 4-6 parts of aluminum oxide and 2-3 parts of stearic acid to 8-12 parts of sodium dodecylbenzene sulfonate solution, and then add 1-3 parts of yttrium nitrate solution and 2-5 parts of nano-silica agent to mix well to obtain a modified solution;

[0034] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0035] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1000-1500 r / min for 1-2 hours. After the ball milling is completed, wash with water and dry to obtain high-whiteness titanium dioxide for papermaking.

[0036] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 4-7%; the mass fraction of the yttrium nitrate solution is 2-5%.

[0037] The immersion stirring modification of this embodiment has an immersion speed of 550-750 r / min and stirring for 1-2 hours.

[0038] The preparation method of the nano silicon dioxide agent of this embodiment is:

[0039] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution with a total amount of 10-15% of the nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0040] S02: Add 2-5 parts of carboxymethyl cellulose, 1-3 parts of nano silica sol, and 1-2 parts of silane coupling agent KH560 to 4-7 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution;

[0041] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0042] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 2-5%; the pH value of the phosphate buffer solution is 5.5.

[0043] The mixed ball milling process of this embodiment has a ball milling speed of 1000-1500 r / min and the ball milling is performed for 2 hours.

[0044] The preparation method of the ball mill of this embodiment is:

[0045] S11: heat treating the nano-attapulgite at 250-260°C for 5-10 min, then heating to 355°C at a rate of 1-3°C / min, keeping the temperature for 2-5 min, and then cooling to 55°C at a rate of 2-5°C / min, and keeping the temperature;

[0046] S12: The nano-attapulgite and ball milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball milling agent is obtained.

[0047] The ultrasonic power of the mixed ultrasonic treatment in this embodiment is 350-400W, and the ultrasonic time is 20-30min.

[0048] The preparation method of the ball milling liquid of this embodiment is:

[0049] 4-7 parts of 5% chitosan solution, 1-3 parts of hydroxyapatite, 2-5 parts of sodium citrate and 2-4 parts of nano-silica sol are fully mixed to obtain a ball milling solution.

[0050] The present embodiment provides a method for preparing high-whiteness titanium dioxide for papermaking to prepare high-whiteness titanium dioxide.

[0051] Example 1.

[0052] A method for preparing high whiteness titanium dioxide for papermaking in this embodiment comprises the following steps:

[0053] Step 1, heat treating titanium dioxide at 125°C for 5 minutes, and then naturally cooling to room temperature;

[0054] Step 2, preparation of modified solution:

[0055] 4 parts of aluminum oxide and 2 parts of stearic acid are added to 8 parts of sodium dodecylbenzene sulfonate solution, and then 1 part of yttrium nitrate solution and 2 parts of nano-silica agent are added and mixed to obtain a modified solution;

[0056] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0057] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1000 r / min for 1 hour. After the ball milling is completed, wash with water, and dry to obtain high-whiteness titanium dioxide for papermaking.

[0058] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 4%; the mass fraction of the yttrium nitrate solution is 2%.

[0059] The immersion stirring modification of this embodiment has an immersion speed of 550 r / min and stirring for 1 hour.

[0060] The preparation method of the nano silicon dioxide agent of this embodiment is:

[0061] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution containing 10% of the total amount of nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0062] S02: Add 2 parts of carboxymethyl cellulose, 1 part of nano silica sol, and 1 part of silane coupling agent KH560 to 4 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution;

[0063] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0064] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 2%; the pH value of the phosphate buffer solution is 5.5.

[0065] The mixed ball milling process of this embodiment has a ball milling speed of 1000 r / min and a ball milling time of 2 h.

[0066] The preparation method of the ball mill of this embodiment is:

[0067] S11: The nano-attapulgite is first heat treated at 250°C for 5 min, then heated to 355°C at a rate of 1°C / min, kept at that temperature for 2 min, and then cooled to 55°C at a rate of 2°C / min, and kept at that temperature;

[0068] S12: The nano-attapulgite and ball-milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball-milling agent is obtained.

[0069] The ultrasonic power of the mixed ultrasonic treatment in this embodiment is 3500W, and the ultrasonic time is 20min.

[0070] The preparation method of the ball milling liquid of this embodiment is:

[0071] 4 parts of 5% chitosan solution, 1 part of hydroxyapatite, 2 parts of sodium citrate and 2 parts of nano-silica sol are fully blended to obtain a ball milling solution.

[0072] The present embodiment provides a method for preparing high-whiteness titanium dioxide for papermaking to prepare high-whiteness titanium dioxide.

[0073] Example 2.

[0074] A method for preparing high whiteness titanium dioxide for papermaking in this embodiment comprises the following steps:

[0075] Step 1, heat treating titanium dioxide at 135° C. for 10 min, and then naturally cooling to room temperature;

[0076] Step 2, preparation of modified solution:

[0077] 6 parts of aluminum oxide and 3 parts of stearic acid are added to 12 parts of sodium dodecylbenzene sulfonate solution, and then 3 parts of yttrium nitrate solution and 5 parts of nano-silica agent are added to mix well to obtain a modified solution;

[0078] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0079] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1500 r / min for 2 hours. After the ball milling is completed, wash with water, and dry to obtain high-whiteness titanium dioxide for papermaking.

[0080] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 7%; the mass fraction of the yttrium nitrate solution is 5%.

[0081] The immersion speed of the immersion stirring modification in this embodiment is 750 r / min, and the stirring is 2 h.

[0082] The preparation method of the nano silicon dioxide agent of this embodiment is:

[0083] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution containing 15% of the total amount of nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0084] S02: Add 5 parts of carboxymethyl cellulose, 3 parts of nano silica sol, and 2 parts of silane coupling agent KH560 to 7 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution;

[0085] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0086] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 5%; the pH value of the phosphate buffer solution is 5.5.

[0087] The mixed ball milling process of this embodiment was carried out at a ball milling speed of 1500 r / min and the ball milling was carried out for 2 h.

[0088] The preparation method of the ball mill of this embodiment is:

[0089] S11: The nano-attapulgite was first heat treated at 260°C for 10 min, then heated to 355°C at a rate of 3°C / min, kept at that temperature for 5 min, and then cooled to 55°C at a rate of 5°C / min, and kept at that temperature;

[0090] S12: The nano-attapulgite and ball-milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball-milling agent is obtained.

[0091] The ultrasonic power of the mixed ultrasonic treatment in this embodiment is 400 W, and the ultrasonic time is 30 min.

[0092] The preparation method of the ball milling liquid of this embodiment is:

[0093] 7 parts of 5% chitosan solution, 3 parts of hydroxyapatite, 5 parts of sodium citrate and 4 parts of nano-silica sol are fully blended to obtain a ball milling solution.

[0094] The present embodiment provides a method for preparing high-whiteness titanium dioxide for papermaking to prepare high-whiteness titanium dioxide.

[0095] Example 3.

[0096] A method for preparing high whiteness titanium dioxide for papermaking in this embodiment comprises the following steps:

[0097] Step 1, heat treating titanium dioxide at 130° C. for 7.5 min, and then naturally cooling to room temperature;

[0098] Step 2, preparation of modified solution:

[0099] Add 5 parts of aluminum oxide and 2.5 parts of stearic acid to 10 parts of sodium dodecylbenzene sulfonate solution, and then add 2 parts of yttrium nitrate solution and 3.5 parts of nano-silica agent to mix well to obtain a modified solution;

[0100] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0101] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1250 r / min for 1.5 h. After the ball milling is completed, wash with water, and dry to obtain high-whiteness titanium dioxide for papermaking.

[0102] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 5.5%; the mass fraction of the yttrium nitrate solution is 3.5%.

[0103] The immersion speed of the immersion stirring modification in this embodiment is 650 r / min, and the stirring is 1.5 hours.

[0104] The preparation method of the nano silicon dioxide agent of this embodiment is:

[0105] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution with a total amount of 12.5% ​​of nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0106] S02: adding 3.5 parts of carboxymethyl cellulose, 2 parts of nano silica sol, and 1.5 parts of silane coupling agent KH560 to 5.5 parts of 5% by mass lanthanum chloride solution and stirring thoroughly to obtain a treatment solution;

[0107] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0108] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 3.5%; the pH value of the phosphate buffer solution is 5.5.

[0109] The mixed ball milling process of this embodiment was carried out at a ball milling speed of 1250 r / min and the ball milling was carried out for 2 h.

[0110] The preparation method of the ball mill of this embodiment is:

[0111] S11: The nano-attapulgite is first heat treated at 255°C for 7.5 min, then heated to 355°C at a rate of 2°C / min, kept at that temperature for 3.5 min, and then cooled to 55°C at a rate of 3.5°C / min, and kept at that temperature;

[0112] S12: The nano-attapulgite and ball-milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball-milling agent is obtained.

[0113] The ultrasonic power of the mixed ultrasonic treatment in this embodiment is 370W, and the ultrasonic time is 25min.

[0114] The preparation method of the ball milling liquid of this embodiment is:

[0115] 5.5 parts of 5% chitosan solution, 2 parts of hydroxyapatite, 3.5 parts of sodium citrate and 3 parts of nano-silica sol were fully blended to obtain a ball milling solution.

[0116] The present embodiment provides a method for preparing high-whiteness titanium dioxide for papermaking to prepare high-whiteness titanium dioxide.

[0117] Example 4.

[0118] A method for preparing high whiteness titanium dioxide for papermaking in this embodiment comprises the following steps:

[0119] Step 1, heat treating titanium dioxide at 126°C for 5-10 minutes, and then naturally cooling to room temperature;

[0120] Step 2, preparation of modified solution:

[0121] Add 5 parts of aluminum oxide and 2.2 parts of stearic acid to 9 parts of sodium dodecylbenzene sulfonate solution, and then add 2 parts of yttrium nitrate solution and 3 parts of nano-silica agent to fully mix and obtain a modified solution;

[0122] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0123] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1200 r / min for 1.2 h. After the ball milling is completed, wash with water, and dry to obtain high-whiteness titanium dioxide for papermaking.

[0124] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 5%; the mass fraction of the yttrium nitrate solution is 3%.

[0125] The immersion speed of the immersion stirring modification in this embodiment is 560r / min, and the stirring is 1.2h.

[0126] The preparation method of the nano silicon dioxide agent of this embodiment is:

[0127] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution containing 12% of the total amount of nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0128] S02: Add 3 parts of carboxymethyl cellulose, 2 parts of nano silica sol, and 1.2 parts of silane coupling agent KH560 to 5 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution;

[0129] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0130] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 3%; the pH value of the phosphate buffer solution is 5.5.

[0131] The mixed ball milling process of this embodiment has a ball milling speed of 1000-1500 r / min and the ball milling is performed for 2 hours.

[0132] The preparation method of the ball mill of this embodiment is:

[0133] S11: The nano-attapulgite was first heat treated at 252°C for 6 min, then heated to 355°C at a rate of 2°C / min, kept at that temperature for 3 min, and then cooled to 55°C at a rate of 3°C / min, and kept at that temperature;

[0134] S12: The nano-attapulgite and ball milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball milling agent is obtained.

[0135] The ultrasonic power of the mixed ultrasonic treatment in this embodiment is 360W, and the ultrasonic time is 22min.

[0136] The preparation method of the ball milling liquid of this embodiment is:

[0137] 5 parts of 5% chitosan solution, 2 parts of hydroxyapatite, 3 parts of sodium citrate and 3 parts of nano-silica sol are fully blended to obtain a ball milling solution.

[0138] The present embodiment provides a method for preparing high-whiteness titanium dioxide for papermaking to prepare high-whiteness titanium dioxide.

[0139] Example 5.

[0140] A method for preparing high whiteness titanium dioxide for papermaking in this embodiment comprises the following steps:

[0141] Step 1, heat treating titanium dioxide at 126°C for 8 minutes, and then naturally cooling to room temperature;

[0142] Step 2, preparation of modified solution:

[0143] Add 5 parts of aluminum oxide and 3 parts of stearic acid to 11 parts of sodium dodecylbenzene sulfonate solution, and then add 2 parts of yttrium nitrate solution and 3 parts of nano-silica agent to mix well to obtain a modified solution;

[0144] Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed;

[0145] Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1450 r / min for 1.8 h. After the ball milling is completed, wash with water, and dry to obtain high-whiteness titanium dioxide for papermaking.

[0146] The mass fraction of the sodium dodecylbenzenesulfonate solution in this embodiment is 6%; the mass fraction of the yttrium nitrate solution is 5%.

[0147] The immersion speed of the immersion stirring modification in this embodiment is 720 r / min, and the stirring is 1.2 h.

[0148] The preparation method of the nano silicon dioxide agent of this embodiment is:

[0149] S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution containing 14% of the total amount of nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid;

[0150] S02: Add 4 parts of carboxymethyl cellulose, 2 parts of nano silica sol, and 2 parts of silane coupling agent KH560 to 6 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution;

[0151] S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

[0152] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 4%; the pH value of the phosphate buffer solution is 5.5.

[0153] The mixed ball milling process of this embodiment has a ball milling speed of 1400 r / min and a ball milling time of 2 h.

[0154] The preparation method of the ball mill of this embodiment is:

[0155] S11: The nano-attapulgite was first heat treated at 255°C for 8 min, then heated to 355°C at a rate of 2°C / min, kept at that temperature for 4 min, and then cooled to 55°C at a rate of 3°C / min, and kept at that temperature;

[0156] S12: The nano-attapulgite and ball milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball milling agent is obtained.

[0157] The ultrasonic power of the mixed ultrasonic treatment in this embodiment is 390W, and the ultrasonic time is 28min.

[0158] The preparation method of the ball milling liquid of this embodiment is:

[0159] 6 parts of 5% chitosan solution, 3 parts of hydroxyapatite, 4 parts of sodium citrate and 3 parts of nano-silica sol are fully blended to obtain a ball milling solution.

[0160] The present embodiment provides a method for preparing high-whiteness titanium dioxide for papermaking to prepare high-whiteness titanium dioxide.

[0161] Comparative Example 1.

[0162] The difference from Example 3 is that no modification liquid treatment was used.

[0163] Comparative Example 2.

[0164] The difference from Example 3 is that no nano silicon dioxide agent is added to the modified liquid.

[0165] Comparative Example 3.

[0166] The difference from Example 3 is that the nano silicon dioxide agent is replaced by nano silicon dioxide.

[0167] Comparative Example 4.

[0168] The difference from Example 3 is that no treatment liquid is used in the preparation of the nano-silica agent.

[0169] Comparative Example 5.

[0170] The difference from Example 3 is that no ball milling agent was added.

[0171] Comparative Example 6.

[0172] The difference from Example 3 is that the ball milling agent is not treated with ball milling liquid.

[0173] The products of Examples 1-5 of the present invention and Comparative Examples 1-6 were placed at 55°C and a light intensity of 45 W / m2 for 12 hours to test the aging of the products. The performance test results are as follows.

[0174]

[0175]

[0176] It can be seen from Examples 1-5 and Comparative Examples 1-6 that the products of Examples 1-5 of the present invention have excellent whiteness and retention rate, and the products have significant aging resistance and stability. The products are not treated with a modifying liquid and no ball mill is added, and the performance of the products deteriorates significantly. The two are coordinated and work together to achieve the most significant performance effect of the products. No nano-silica agent is added to the modifying liquid, the nano-silica agent is replaced by nano-silica, the nano-silica agent is not treated with a treatment liquid in preparation, and the ball mill is not treated with a ball mill. The performance of the products has a tendency to deteriorate. Only the product raw material obtained by the method of the present invention has the most significant product performance effect. The effects of other methods are not as obvious as those of the present invention.

[0177] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0178] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing high whiteness titanium dioxide for papermaking, characterized in that: The following steps are involved: Step 1, heat treating titanium dioxide at 125-135° C. for 5-10 min, and then naturally cooling to room temperature; Step 2, preparation of modified solution: Add 4-6 parts of aluminum oxide and 2-3 parts of stearic acid to 8-12 parts of sodium dodecylbenzene sulfonate solution, and then add 1-3 parts of yttrium nitrate solution and 2-5 parts of nano-silicon dioxide agent to fully mix and obtain a modified solution; Step 3, immersing the product of step 1 into a sufficient amount of modification liquid, stirring and modifying the product, washing with water, filtering and drying the product after the stirring is completed; Step 4: Mix the product of step 3 and the ball milling agent in a weight ratio of 5:3, and ball mill the mixture at a speed of 1000-1500 r / min for 1-2 hours. After the ball milling is completed, wash with water and dry to obtain high-whiteness titanium dioxide for papermaking.

2. The method for preparing high whiteness titanium dioxide for papermaking according to claim 1, characterized in that: The mass fraction of the sodium dodecylbenzene sulfonate solution is 4-7%; the mass fraction of the yttrium nitrate solution is 2-5%.

3. The method for preparing high whiteness titanium dioxide for papermaking according to claim 1, characterized in that: The immersion speed of the modified immersion stirring method is 550-750 r / min, and the stirring is 1-2 hours.

4. The method for preparing high whiteness titanium dioxide for papermaking according to claim 1, characterized in that: The preparation method of the nano silicon dioxide agent is: S01: adding nano-silicon dioxide to sodium lignin sulfonate solution at a weight ratio of 2:5, and then adding phosphate buffer solution with a total amount of 10-15% of the nano-silicon dioxide to fully mix to obtain nano-silicon dioxide liquid; S02: Add 2-5 parts of carboxymethyl cellulose, 1-3 parts of nano silica sol, and 1-2 parts of silane coupling agent KH560 to 4-7 parts of 5% by mass lanthanum chloride solution and stir thoroughly to obtain a treatment solution; S03: Mix the nano-silica liquid and the treatment liquid in a weight ratio of 2:5 and perform ball milling. After the ball milling is completed, wash with water and dry to obtain the nano-silica agent.

5. The method for preparing high whiteness titanium dioxide for papermaking according to claim 4, characterized in that: The mass fraction of the sodium lignin sulfonate solution is 2-5%; the pH value of the phosphate buffer solution is 5.

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6. The method for preparing high whiteness titanium dioxide for papermaking according to claim 4, characterized in that: The mixed ball milling process is performed at a ball milling speed of 1000-1500 r / min and the ball milling is performed for 2 hours.

7. The method for preparing high whiteness titanium dioxide for papermaking according to claim 1, characterized in that: The preparation method of the ball mill is: S11: heat treating the nano-attapulgite at 250-260°C for 5-10 min, then heating to 355°C at a rate of 1-3°C / min, keeping the temperature for 2-5 min, and then cooling to 55°C at a rate of 2-5°C / min, and keeping the temperature; S12: The nano-attapulgite and ball-milling liquid kept warm in S11 are mixed in a weight ratio of 2:5 and subjected to ultrasonic treatment. After the ultrasonic treatment is terminated, a ball-milling agent is obtained.

8. The method for preparing high whiteness titanium dioxide for papermaking according to claim 7, characterized in that: The ultrasonic power of the mixed ultrasonic treatment is 350-400W, and the ultrasonic time is 20-30min.

9. The method for preparing high whiteness titanium dioxide for papermaking according to claim 7, characterized in that: The preparation method of the ball milling liquid is: 4-7 parts of 5% chitosan solution, 1-3 parts of hydroxyapatite, 2-5 parts of sodium citrate and 2-4 parts of nano-silica sol are fully mixed to obtain a ball milling solution.

10. A high whiteness titanium dioxide prepared by the method for preparing high whiteness titanium dioxide for papermaking according to any one of claims 1 to 9.

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