Method for Preparing Heavy Calcium Carbonate with Low Oil Absorption Value by Using Composite Surface Modifier

Abstract

The present invention provides a method for preparing heavy calcium carbonate with low oil absorption value by using a composite surface modifier, which consists of the following steps: Weigh heavy calcium carbonate powder (800 mesh) and place it in a high-speed mixer with controllable temperature, and set the temperature at 110 °C; Weigh composite surface modifiers (polyethylene glycol-300, sodium dodecyl sulfate and sodium stearate) with different mass ratios and 6 ml of water, place them in a small beaker, heat to dissolve them for standby; When the temperature of the high-speed mixer rises to 110 °C, drop the composite surface modifier into it, modify it at low speed for 5 minutes first, and then modify it at high speed for 5 minutes to obtain heavy calcium carbonate with low oil absorption value, and the oil absorption value is 14.7-16.5 g / 100 g. The technology of the present invention can significantly improve the surface modification and activation effect of heavy calcium carbonate powder, greatly reduce the oil absorption value, and has the advantages of simple treatment process, low energy consumption and strong timeliness, etc., and is an effective method for producing heavy calcium carbonate powder with low oil absorption value.

Description

Technical Field

[0001] This invention patent relates to surface modifiers and calcium carbonate with low oil absorption value, specifically to a method for preparing heavy calcium carbonate with low oil absorption value using a composite surface modifier. Background Art

[0002] Heavy calcium carbonate is an important non-metallic mineral material that is green, environmentally friendly, energy-saving, emission-reducing, and in line with the country's sustainable development. Its application fields are gradually expanding, and the market demand is growing rapidly. Today, with the strong advocacy of low-carbon economy, increasing the filling amount of heavy calcium carbonate, reducing the resin usage, and lowering the production cost are in line with the green development concept of energy conservation and environmental protection.

[0003] The oil absorption value, also known as the resin adsorption amount, is an index indicating the amount of resin absorbed by the filler. This index can roughly predict the demand for resin by the filler. The smaller the oil absorption value of the filler, the less resin is consumed, and the higher the economic benefit. Reducing the oil absorption value of heavy calcium carbonate can greatly improve the dispersibility and lipophilicity of the particles.

[0004] Zheng Dianmo studied the composite modification of 800-mesh calcium carbonate with stearic acid, ethylene glycol bis(dioctyl phosphate) titanate, and polyethylene glycol. The research proved that surfactants with long-chain alkyl groups have the best modification effect on calcium carbonate. The modification effect of using a composite modifier is better than that of using a single modifier. The dosage of the composite modifier is 1.5 wt%, the modification temperature is 118 °C, the modification time is 70 min, and the stirring speed is 1600 r / min. The oil absorption value of the calcium carbonate powder decreased from 31.5 mL / 100 g to 15.4 mL / 100 g (Research on the Surface Treatment of Calcium Carbonate with Composite Modifiers [J]. Journal of Nanchang University, 2002, 24(3): 87 - 90). Surface modifiers with different structures exhibit different properties and modification effects. Therefore, according to the property characteristics of different surface modifiers, optimizing the composite recombination of the modifiers can give full play to the unique advantages of different modifiers, making the surface modification effect better, the oil absorption value lower, and better meeting the needs of different personalized, functional, and professional fields.

[0005] Zhou Guoyong et al. wet-modified 10μm heavy calcium carbonate powder with maleic anhydride-acrylamide-n-butyl methacrylate copolymer. The optimal dosage was 2%, the modification temperature was 85°C, the modification time was 120 min, and the stirring speed was 500 r / min. The oil absorption value of the calcium carbonate powder obtained was 20 mL / 100 g (Research progress on the compatibility modification of heavy calcium carbonate particles [J]. Applied Chemical Industry, 2014, 43(1): 137-141). Wang You used Span60 as the modifier and ethanol as the dispersant to surface-modify 15μm heavy calcium carbonate powder by ball milling method, and determined the optimal modification conditions as follows: the ball milling speed was 300 r / min, the ball milling time was 0.5 h, the ball-to-material ratio was 10:1, and the dosage of the modifier was 1.5 wt%. The oil absorption value of the calcium carbonate obtained was 20 mL / 100 g (Wang You. Research on the surface modification of heavy calcium carbonate powder with Span60 [J]. Inorganic Chemicals Industry, 2016, 48(7): 25-28). Li Min et al. first mixed calcium carbonate powder with anhydrous citric acid, polyethylene glycol or polyacrylamide, and then carried out the second mixing with stearic acid. The two mixing methods were ball milling, the rotation speed was 100-150 rpm, the ball milling time was 1-2 h, and then the modification treatment was carried out at a temperature of 125-150°C for 2-3 h. The dosages of the two modifiers were 0.1-0.2% and 0.4-0.6% respectively. The oil absorption value of the calcium carbonate powder decreased from 33.95 mL / 100 g to 17 mL / 100 g.

[0006] However, the above existing technologies for modifying calcium carbonate powder still have defects such as cumbersome processing technology, long treatment time, insufficient oil absorption value, and high energy consumption. To meet the increasingly prominent need for low-carbon environmental protection, it is necessary to prepare heavy calcium carbonate with low oil absorption value by using low energy consumption and rapid modification treatment. Summary of the Invention

[0007] Aiming at the defects of the existing surface modifiers for treating calcium carbonate, such as long treatment time, insufficient oil absorption value, and high energy consumption, the purpose of the present invention is to provide a method for preparing heavy calcium carbonate with low oil absorption value by using a composite surface modifier. This technology can significantly improve the surface modification activation effect of calcium carbonate powder, greatly reduce the oil absorption value of calcium carbonate powder, and has the advantages of simple treatment process, low energy consumption, and strong timeliness. It is an effective method for producing heavy calcium carbonate powder with low oil absorption value. The method for preparing heavy calcium carbonate with low oil absorption value by using the composite surface modifier of the present invention consists of the following steps:

[0008] (1) Weigh 500 g of heavy calcium carbonate powder (800 mesh) and place it in a high-speed mixer with controllable temperature, and set the temperature to 110°C;

[0009] (2) Weigh 10 g of composite surface modifiers with different mass ratios and 6 ml of water, place them in a small beaker, heat to dissolve them for later use;

[0010] When the temperature of the high-speed mixer rises to 110°C, add (2) dropwise, first perform low-speed modification for 5 minutes, and then perform high-speed modification for 5 minutes to obtain heavy calcium carbonate with a low oil absorption value, and the oil absorption value is 14.7 - 16.5 g / 100 g of heavy calcium carbonate powder.

[0011] The heating temperature described in the above step (2) is 80°C;

[0012] The composite surface modifier with different mass ratios described in the above step (2) is polyethylene glycol-300, sodium dodecyl sulfate, and sodium stearate;

[0013] The preferred mass ratio of the composite surface modifier described in the above step (2) is 5:2.5:2.5, 6:3:1, 6:2:2, and 7:2:1.

[0014] The method for preparing heavy calcium carbonate with a low oil absorption value using the composite surface modifier of the present invention significantly reduces the oil absorption value of calcium carbonate, is an effective method for producing heavy calcium carbonate powder with a low oil absorption value, and has great economic value and promotion value. The present invention will be further described below in conjunction with examples. Detailed implementation mode

[0015] Example 1:

[0016] (1) Weigh 500 g of heavy calcium carbonate powder (800 mesh) and place it in a temperature-controlled high-speed mixer, and set the temperature to 110°C;

[0017] (2) Weigh 10 g of the composite surface modifier with different mass ratios (polyethylene glycol-300, sodium dodecyl sulfate, and sodium stearate = 5:2.5:2.5), and 6 ml of water, place them in a small beaker, heat to dissolve, and set aside;

[0018] (3) When the temperature in the high-speed mixer rises to 110°C, add (2) dropwise, first perform low-speed modification for 5 minutes, and then perform high-speed modification for 5 minutes to obtain heavy calcium carbonate powder with an oil absorption value, and the oil absorption value is 14.7 g / 100 g of heavy calcium carbonate.

[0019] Example 2:

[0020] (1) Weigh 500 g of heavy calcium carbonate powder (800 mesh) and place it in a temperature-controlled high-speed mixer, and set the temperature to 110°C;

[0021] (2) Weigh 10 g of the composite surface modifier with different mass ratios (polyethylene glycol-300, sodium dodecyl sulfate, and sodium stearate = 6:3:1), and 6 ml of water, place them in a small beaker, heat to dissolve, and set aside;

[0022] (3) When the temperature in the high-speed mixer rises to 110 °C, add (2) dropwise, first perform low-speed modification for 5 min, and then perform high-speed modification for 5 min to obtain heavy calcium carbonate with a low oil absorption value. The oil absorption value is 15.3 g / 100 g of heavy calcium carbonate powder.

[0023] Example 3:

[0024] (1) Weigh 500 g of heavy calcium carbonate powder (800 mesh) and place it in a temperature-controlled high-speed mixer, and set the temperature to 110 °C;

[0025] (2) Weigh 10 g of a composite surface modifier with different mass ratios (polyethylene glycol-300, sodium dodecyl sulfate, and sodium stearate = 6:2:2), and 6 ml of water, place them in a small beaker, heat to dissolve, and set aside;

[0026] (3) When the temperature in the high-speed mixer rises to 110 °C, add (2) dropwise, first perform low-speed modification for 5 min, and then perform high-speed modification for 5 min to obtain heavy calcium carbonate with a low oil absorption value. The oil absorption value is 15.5 g / 100 g of heavy calcium carbonate powder.

[0027] Example 4:

[0028] (1) Weigh 500 g of heavy calcium carbonate powder (800 mesh) and place it in a temperature-controlled high-speed mixer, and set the temperature to 110 °C;

[0029] (2) Weigh 10 g of a composite surface modifier with different mass ratios (polyethylene glycol-300, sodium dodecyl sulfate, and sodium stearate = 7:2:1), and 6 ml of water, place them in a small beaker, heat to dissolve, and set aside;

[0030] (3) When the temperature in the high-speed mixer rises to 110 °C, add (2) dropwise, first perform low-speed modification for 5 min, and then perform high-speed modification for 5 min to obtain heavy calcium carbonate with a low oil absorption value. The oil absorption value is 16.5 g / 100 g of heavy calcium carbonate powder.

[0031] Experimental data confirm that the method of using a composite surface modifier to prepare heavy calcium carbonate with a low oil absorption value has an oil absorption value as low as 14.7 - 16.5 g / 100 g. Compared with the oil absorption value of untreated heavy calcium carbonate powder, which is 33 g / 100 g, the present invention can significantly reduce the oil absorption value of heavy calcium carbonate powder and is an effective method for producing heavy calcium carbonate powder with a low oil absorption value.

[0032] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing heavy calcium carbonate with low oil absorption value by using a composite surface modifier, which is characterized in that, It consists of the following steps: (1) Weigh 500 g of heavy calcium carbonate powder (800 mesh) and place it in a high-speed mixer with controllable temperature, and set the temperature at 110 °C; (2) Weigh 10 g of composite surface modifiers with different mass ratios and 6 ml of water, put them into a small beaker, heat to dissolve them for later use; (3) When the temperature of the high-speed mixer rises to 110 °C, drop the solution in (2), modify it at low speed for 5 min first, and then modify it at high speed for 5 min, then low oil absorption value heavy calcium carbonate can be obtained, and the oil absorption value is 14.7 - 16.5 g / 100 g of heavy calcium carbonate powder; The composite surface modifiers with different mass ratios described in step (2) above are polyethylene glycol - 300, sodium dodecyl sulfate and sodium stearate; The mass ratio of the composite surface modifiers with different mass ratios described in step (2) above is 5:2.5:2.5 or 6:3:1 or 6:2:2 or 7:2:1.