Stearic acid coated calcium carbonate dispersion as well as preparation method and application thereof

Abstract

The invention relates to the technical field of C08K3 / 26, in particular to a stearic acid coated calcium carbonate dispersoid and a preparation method and application thereof.The stearic acid coated calcium carbonate dispersoid is at least prepared from, by weight, 700-800 parts of stearic acid coated calcium carbonate, 10-25 parts of dispersing agent, 0.5-2 parts of defoaming agent and 200-300 parts of water; the stearic acid coated calcium carbonate is matched with the dispersing agent and the defoaming agent to obtain the low-viscosity stearic acid coated calcium carbonate dispersion which is uniform in dispersion and fine in material body, and the subsequent application requirements in rubber products are met.

Description

Technical Field

[0001] The invention relates to the technical field of C08K3 / 26, and in particular to a stearic acid-coated calcium carbonate dispersion and a preparation method and application thereof. Background Art

[0002] Inorganic powders such as calcium carbonate are widely available and low-cost, and are widely used in polymer systems. However, due to the insufficient surface bonding between inorganic powders and resin materials, the addition of calcium carbonate powder will have a certain impact on the performance of the product. As the addition ratio increases, the impact on the mechanical properties of the product gradually increases. In severe cases, it may even cause product failure and seriously affect the use of the product, which greatly limits the application of calcium carbonate powder in glove products. A Chinese patent (publication number CN 115584058 A) discloses a calcium carbonate dispersion and its preparation method and application, which mainly ensures the subsequent application performance in rubber products by surface treating the calcium carbonate dispersion, controlling the calcium carbonate particle size and controlling the pH of the calcium carbonate dispersion, but the dispersibility of the calcium carbonate dispersion needs to be further improved. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a stearic acid-coated calcium carbonate dispersion, which uses stearic acid-coated calcium carbonate in combination with a dispersant and a defoaming agent to obtain a low-viscosity stearic acid-coated calcium carbonate dispersion with uniform dispersion and fine material body, thereby meeting the subsequent application requirements in rubber products.

[0004] On one hand, the present invention provides a stearic acid-coated calcium carbonate dispersion, wherein the preparation raw materials thereof at least include 700-800 parts of stearic acid-coated calcium carbonate, 10-25 parts of a dispersant, 0.5-2 parts of a defoaming agent, and 200-300 parts of water, in parts by weight.

[0005] As a preferred technical solution, the preparation method of stearic acid-coated calcium carbonate is: diluting stearic acid with a solvent to obtain a stearic acid-modified liquid, and dripping the stearic acid-modified liquid during the grinding process of calcium carbonate to perform surface modification to obtain the stearic acid-coated calcium carbonate.

[0006] As a preferred technical solution, the added amount of stearic acid is 0.8-1.5% of the mass of calcium carbonate, preferably 1-1.2%.

[0007] As a preferred technical solution, the mass concentration of stearic acid in the stearic acid modified liquid is 10-30%.

[0008] As a preferred technical solution, the solvent is selected from at least one of methanol and ethanol.

[0009] As a preferred technical solution, the surface modification temperature is 80-120° C., and the surface modification time is 15-60 min.

[0010] As a preferred technical solution, the dispersant is selected from at least one of CLiQSPERSE127, CLiQSPERSE128, CLiQSPERSE125, Youka 730U, and Beijing Guzhengben 5040, and is preferably a combination of CLiQSPERSE127 and CLiQSPERSE127128 (both from CLiQwissTech AG).

[0011] Preferably, the mass ratio of CLiQSPERSE127 and CLiQSPERSE128 is (1-3):1, preferably (2-2.5):1, and preferably 2:1.

[0012] Preferably, the defoaming agent is selected from at least one of AFE-3168 of Dow Chemical and 603 of Longhai Chemical, preferably 603 of Longhai Chemical.

[0013] The present invention uses stearic acid to coat and modify calcium carbonate, and controls the modification process conditions to significantly improve the dispersibility of calcium carbonate and the compatibility with rubber. Further, by coordinating a dispersant and a defoamer, especially when the dispersant is a combination of CLiQSPERSE127 and CLiQSPERSE128, the defoamer in the system is coordinated to make the prepared stearic acid-coated calcium carbonate stably and evenly dispersed in water, ensuring the stability of the dispersion in subsequent nitrile rubber products, and avoiding the problem of nitrile rubber precipitation.

[0014] On the other hand, the present invention provides a method for preparing a stearic acid-coated calcium carbonate dispersion, which comprises at least the following steps: adding water and a dispersant into a container, adding a defoamer under stirring, stirring for 3-8 minutes, adding stearic acid-coated calcium carbonate, stirring and dispersing for 20-60 minutes to obtain a stearic acid-coated calcium carbonate dispersion.

[0015] As a preferred technical solution, the solid content of the stearic acid-coated calcium carbonate dispersion is ≥70wt%.

[0016] As a preferred technical solution, the viscosity of the stearic acid-coated calcium carbonate dispersion (NDJ-1 viscometer, No. 2 rotor, speed of 60 rpm, temperature of 25° C.) is 20-600 mPa.s.

[0017] As a preferred technical solution, the pH of the stearic acid-coated calcium carbonate dispersion is 7-9.5, preferably 7.3-9.3, and more preferably 8-8.5.

[0018] The third aspect of the present invention provides an application of a stearic acid-coated calcium carbonate dispersion in the preparation of nitrile rubber, wherein the amount of the stearic acid-coated calcium carbonate dispersion added to the nitrile rubber is 20-80wt%.

[0019] The stearic acid-coated calcium carbonate dispersion provided by the present invention has good dispersion compatibility when subsequently introduced into a nitrile rubber system, can improve the gram weight and strength of nitrile rubber products, and reduce the production cost of nitrile rubber products.

[0020] Beneficial Effects

[0021] 1. The present invention provides a stearic acid-coated calcium carbonate dispersion, which uses stearic acid-coated calcium carbonate in combination with a dispersant and a defoaming agent to obtain a low-viscosity stearic acid-coated calcium carbonate dispersion with uniform dispersion and fine material body, thereby meeting the subsequent application requirements in rubber products.

[0022] 2. The present invention adopts stearic acid to coat and modify calcium carbonate, and controls the modification process conditions to significantly improve the dispersibility of calcium carbonate and its compatibility with rubber.

[0023] 3. The dispersion provided by the present invention is formulated with a dispersant and a defoamer, especially when the dispersant is a combination of CLiQSPERSE127 and CLiQSPERSE128, and the defoamer in the formulation system makes the prepared stearic acid-coated calcium carbonate stably and evenly dispersed in water, thereby ensuring the stability of the dispersion in subsequent nitrile rubber products and avoiding problems such as precipitation of nitrile rubber.

[0024] 4. The stearic acid-coated calcium carbonate dispersion provided by the present invention has good dispersion compatibility when subsequently introduced into the nitrile rubber system, which can improve the gram weight and strength of the nitrile rubber products and reduce the production cost of the nitrile rubber products. DETAILED DESCRIPTION

[0025] Examples 1-12

[0026] On the one hand, Examples 1-12 of the present invention provide a stearic acid-coated calcium carbonate dispersion, and the formula is shown in Table 1 in parts by weight.

[0027] Table 1

[0028]

[0029]

[0030] The preparation method of the stearic acid coated calcium carbonate comprises the following steps: diluting stearic acid with a solvent to obtain a stearic acid modified liquid, and dripping the stearic acid modified liquid during the grinding process of calcium carbonate to perform surface modification to obtain the stearic acid coated calcium carbonate.

[0031] The added amount of stearic acid is 1% of the mass of calcium carbonate.

[0032] The mass concentration of stearic acid in the stearic acid modified liquid is 20%.

[0033] The solvent is selected from ethanol.

[0034] The surface modification temperature is 100° C., and the surface modification time is 60 min.

[0035] On the other hand, Examples 1-12 of the present invention provide a method for preparing a stearic acid-coated calcium carbonate dispersion, comprising the following steps: adding deionized water and a dispersant into a container, adding a defoaming agent under stirring, stirring for 5 minutes, adding stearic acid-coated calcium carbonate, and stirring and dispersing for 30 minutes to obtain a stearic acid-coated calcium carbonate dispersion.

[0036] Performance Testing Methods

[0037] 1. Observe the dispersion effect of the dispersion provided in the embodiment. If the stearic acid-coated calcium carbonate cannot be evenly dispersed and precipitation and stratification occur, the result is recorded as "unqualified"; if the stearic acid-coated calcium carbonate can be evenly dispersed without precipitation and stratification, the result is recorded as "qualified".

[0038] 2. The examples with qualified dispersion effects were subjected to viscosity test and pH test. The test results are shown in Table 2. The test method is as follows:

[0039] (1) Use NDJ-1 viscometer, rotor No. 2, test temperature is 25℃, and test speed is 60 rpm.

[0040] (2) Use an electronic pH meter for testing.

[0041] Table 2

[0042]

[0043]

Claims

1. A stearic acid-coated calcium carbonate dispersion, characterized in that: The raw materials for its preparation include at least 700-800 parts of stearic acid-coated calcium carbonate, 10-25 parts of dispersant, 0.5-2 parts of defoamer and 200-300 parts of water in parts by weight.

2. The stearic acid-coated calcium carbonate dispersion according to claim 1, characterized in that The preparation method of the stearic acid coated calcium carbonate comprises the following steps: diluting stearic acid with a solvent to obtain a stearic acid modified liquid, and dripping the stearic acid modified liquid during the grinding process of calcium carbonate to perform surface modification to obtain the stearic acid coated calcium carbonate.

3. The stearic acid-coated calcium carbonate dispersion according to claim 2, characterized in that: The added amount of stearic acid is 0.8-1.5% of the mass of calcium carbonate.

4. The stearic acid-coated calcium carbonate dispersion according to claim 3, characterized in that: The mass concentration of stearic acid in the stearic acid modified liquid is 10-30%.

5. The stearic acid-coated calcium carbonate dispersion according to claim 4, characterized in that: The solvent is selected from at least one of methanol and ethanol.

6. The stearic acid-coated calcium carbonate dispersion according to claim 5, characterized in that: The surface modification temperature is 80-120° C., and the surface modification time is 15-60 min.

7. The stearic acid-coated calcium carbonate dispersion according to claim 6, characterized in that: The dispersant is selected from at least one of CFC-6530, Beijing Guzhengben 5040, Euka 730U, CLiQSPERSE127, CLiQSPERSE128, and CLiQSPERSE125.

8. The stearic acid-coated calcium carbonate dispersion according to claim 7, characterized in that: The defoaming agent is selected from at least one of AFE-3168 and 603 of Longhai Chemical.

9. A method for preparing a stearic acid-coated calcium carbonate dispersion according to any one of claims 1 to 8, characterized in that: At least the following steps are included: Add water and dispersant into a container, add defoamer under stirring, stir for 3-8 minutes, add stearic acid-coated carbonate, stir and disperse for 20-60 minutes to obtain stearic acid-coated calcium carbonate dispersion.

10. Use of the stearic acid-coated calcium carbonate dispersion according to any one of claims 1 to 8, characterized in that: The invention is applied to the preparation of nitrile rubber, wherein the added amount of the stearic acid-coated calcium carbonate dispersion in the nitrile rubber is 20-80wt%.

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