CN108822579A - A kind of modification shell powder preparation method with good dispersion - Google Patents

Abstract

The invention provides a method for preparing modified shell powder with good dispersibility, comprising the following specific steps: (1) mechanically pulverizing the cleaned shells, adding an appropriate amount of water to make a mortar-like substance, and passing through 400 Mesh filter, then dry at medium and low temperature to make shell powder; (2) add water to the shell powder at room temperature to prepare shell micropowder slurry, add dilute phosphoric acid under the low-speed dispersion condition of electric mixer, make It is fully reacted, and after the reaction is completed, it is filtered, dried, and dispersed to obtain inorganic acid-modified biological calcium carbonate; (3) after low-temperature drying of the shell powder initially modified by phosphoric acid dissolution, the mass fraction is 5 % of the slurry, and then add the organic modifier under agitation. The technical problem to be solved by the present invention is to provide a method for preparing shell powder that can quantitatively remove calcium carbonate in shell powder as required and maintain good dispersion and stability in an organic system.

Description

A preparation method of modified shell powder with good dispersibility

technical field

The invention relates to a method for preparing shell powder, in particular to a method for preparing modified shell powder with good dispersibility.

Background technique

my country's shellfish output reaches about 12 million tons per year, accounting for nearly 60% of the world's total output. It is seldom processed and utilized, and a large number of discarded shells are produced. Not only are they not effectively utilized, but they are also piled up as solid waste on beaches or other garbage dumps, wasting resources and polluting the environment. How to effectively utilize shells, a biomass material mainly composed of calcium carbonate and containing a small amount of organic matter, has always been a hot spot of concern. Although shellmeal has long been used as a livestock feed additive and calcium supplement, its actual use is relatively small and cannot effectively consume the large amount of shellfish accumulations produced every year. In recent years, the use of shell powder in the field of materials has aroused widespread interest. In related fields, the application of shell powder to anti-corrosion coatings has become an important industry at present.

In order to prepare high-performance anti-corrosion coatings, relevant personnel use methods such as adding an appropriate amount of pigments, fillers, and additives to the anti-corrosion coating system to improve the performance of the coating. Among them, calcium carbonate and glass flakes are the most commonly used fillers in the field of anti-corrosion coatings, but inorganic carbonic acid Both calcium powder and glass flakes have significant hydrophilic and oleophobic properties and strong polarity, resulting in poor bonding with resin, poor compatibility, uneven dispersion in organic media, and difficulty in spreading, resulting in defects inside the coating film. Reduce performance. Compared with the above materials, shell nacre is a typical biomineral material composed of calcium carbonate and biological macromolecules. It is a natural inorganic-organic composite material. At the same time, the shell itself has a typical lamellar structure. - Organic phase regulation and modification, development of bioactive calcium carbonate applied to coatings, high added value, large demand, and broad application prospects. Compared with traditional inorganic calcium carbonate and glass flake fillers, it has a direct role in the field of corrosion and protection application prospects. Therefore, the modification of discarded shells produced by aquaculture and other related industries in the marine anti-corrosion coating industry complements the development ideas of green development and low-carbon cycle advocated at home and abroad. Among them, it has become an important research direction in this field to adopt appropriate methods to adjust and control the composition and organic group activity of shell-derived calcium carbonate powder.

The State Intellectual Property Office discloses a shell powder modification method (CN201710183429.2), which specifically prepares a shell powder with a diameter of about 10um by high-temperature calcination and grinding. The method undergoes two high-temperature calcinations, and the highest calcination temperature reaches 1200°C. At such a high temperature, the organic active groups contained in the shell itself basically disappear completely, and the obtained product is almost pure inorganic calcium carbonate powder, which loses the shell. 1. The characteristics of natural inorganic-organic composite materials are not conducive to subsequent dispersion and application in coatings, resins and other systems.

The State Intellectual Property Office discloses a preparation method of shell powder (CN201610697737.2), specifically, washing by soaking, drying at a medium-high temperature (about 450-550°C), and grinding. This method uses simple physical pulverization and medium-temperature calcination to prepare shell powder. Although the active organic groups on the surface are retained, it cannot control the proportion of inorganic and organic components in the powder more accurately. Modification, the dispersibility and stability of powder in organic systems such as coatings still need to be further improved.

The State Intellectual Property Office discloses a preparation method of shell powder modified calcium carbonate (CN201710499629.9), specifically: crush and grind shells to a particle size below 3mm, then roast at high temperature, add an appropriate amount of dispersant and water, grind , filtered, dissolved in water with micron-sized calcium carbonate powder, stirred at high speed, filtered, and dried. The purpose of this method is to achieve its good antibacterial and pollutant adsorption effects by adsorbing shell powder on the surface of tiny calcium carbonate powder, but the modified shell powder obtained by this method is complicated in process, high in cost, and high temperature Calcination destroys the organic active groups of shell powder, which is not conducive to the dispersion in oily systems such as coatings and resins.

The State Intellectual Property Office discloses a method for preparing shell micropowder filler (CN02125731.0), specifically: the shell is cleaned and crushed, and then the polymer chains in the shell are degraded by ultraviolet light and ultrasound, so that the shell powder body is further refined. The disadvantage is that the organic group in the shell is not fully utilized, and no further surface modification is carried out, which affects the dispersion effect and stability of the manufactured powder in the organic system.

The State Intellectual Property Office discloses a natural adsorbent for removing heavy metal ions in water and its preparation method and application (CN200910070793.3). By drying the cleaned shells, crushing them, and finally crushing and grinding them with a ball mill, Obtain shell powder adsorbent. However, this patent only utilizes the adsorption effect of shell powder on heavy metal ions, and does not modify the shell powder.

The State Intellectual Property Office discloses a shell powder and its preparation method, modification method and use (CN201510481985.9), specifically, after the shells are cleaned, they are calcined in three stages, ground into shell powder, and applied In antibacterial and deodorizing coatings. However, this method does not make full use of the organic groups in the shell, and does not carry out further surface modification, which affects the dispersion effect and stability of the manufactured powder in the organic system.

The State Intellectual Property Office discloses a preparation method and product of acid-modified ultra-fine shell powder (CN201310025460.5). Tidal shell powder with a fineness of 0.01-5um, but this patent does not modify the shell powder with a coupling agent, which is not conducive to the dispersion of the modified powder in the organic system.

The State Intellectual Property Office discloses a method for preparing high-purity calcite calcium carbonate micropowder by hydrothermal treatment of shells (CN201310037909.X). This method prepares calcite calcium carbonate by hydrothermal treatment in an autoclave, which is conducive to the recycling of shells, but The shell powder is not modified by the coupling agent, which is not conducive to the dispersion of the modified powder in the organic system.

The State Intellectual Property Office discloses a preparation method of modified shell powder (CN201510938663.2), which specifically uses carbon nanotubes and calcium carbonate powder doping modification to prepare a composite material with high adsorption capacity for heavy metal ions, but This method does not discuss the action effect and dispersion effect of the organic group in the shell-derived calcium carbonate powder.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method that can quantitatively remove the calcium carbonate in the shell powder according to the demand, so that the obtained modified calcium carbonate powder retains calcium carbonate and organic active ingredients according to the required ratio; The modifier increases the activity of the powder and maintains good dispersion and stability in the organic system. The preparation method of shell powder.

In order to solve the above technical problems, the present invention provides a method for preparing modified shell powder with good dispersibility, comprising the following specific steps:

(1) Mechanically pulverize the cleaned shells, add an appropriate amount of water to make a mortar-like substance, filter through a 400-mesh filter, and then dry at medium and low temperatures to make shell powder;

(2) The shell powder is mixed with water at normal temperature to prepare a shell powder slurry, under the low-speed dispersion condition of an electric mixer, slowly add dilute phosphoric acid to the shell powder slurry while stirring in proportion, after the dropwise addition is completed , continue to stir for 30 to 60 minutes to make it fully react, after the reaction is completed, filter, dry, and disperse to obtain inorganic acid modified biological calcium carbonate;

(3) After drying the shell powder initially modified by phosphoric acid dissolution at low temperature, make a slurry with a mass fraction of 5%, and then add an organic modifier under stirring conditions, and the organic modifier is hard Calcium stearate, stearic acid, γ-aminopropyltriethoxysilane, γ-(2,3-glycidoxy)propyltrimethoxysilane, isopropyltrioleyloxytitanate , one of chelating titanate coupling agents, aluminate coupling agents, low temperature drying.

Preferably, as a further optimization improvement, the organic modifier in step (2) is calcium stearate, stearic acid, γ-aminopropyltriethoxysilane, γ-(2,3- Glycidoxy) propyl trimethoxysilane, isopropyl trioleic acid acyloxy titanate, chelating titanate coupling agent, aluminate coupling agent in mass ratio 1: 1 Mixed composition, the addition amount of which is 0.1%-10% of the mass of inorganic acid modified biological calcium carbonate powder.

Preferably, as a further optimization improvement, the particle size of the shell powder obtained through the 400-mesh filter in the step (1) is about 10-50um, and the medium and low temperature is 60-100°C.

Preferably, as a further optimization improvement, the mass content of the fine shell powder slurry in the step (2) is 5-30%, the mass of the phosphoric acid added dropwise is 5-30% of the mass of the fine shell powder, and the dilute phosphoric acid solution The mass concentration is 5-40%.

Preferably, as a further optimization improvement, the low temperature in the step (3) is less than or equal to 60°C.

Compared with the prior art, the present invention has the advantages that: the active calcium carbonate powder prepared by the method is measured as a relatively typical lamellar shape, and the material analysis test proves that a certain amount of organic groups remain on the surface. It has a good dispersion effect and is not easy to reunite. It can be applied to anti-corrosion coating systems. At the same time, it can effectively use discarded shells, turn waste into treasure, and realize the recycling of resources, which is conducive to sustainable development.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of the influence of different modifiers of the present invention on the oil absorption of powders.

Fig. 2 is a schematic diagram of the influence of different modifiers of the present invention on the sedimentation volume of 10p-zyb powder.

Fig. 3 is a schematic diagram of phase analysis of shell powder before and after modification of the present invention.

Fig. 4 is a schematic diagram 1 of infrared spectra of shell powder before and after modification of the present invention.

Fig. 5 is a schematic diagram 2 of the infrared spectra of shell powder before and after modification of the present invention.

Fig. 6 is a schematic diagram 3 of infrared spectra of shell powder before and after modification of the present invention.

Fig. 7 is a schematic SEM diagram 1 of the modified shell powder of the present invention.

Fig. 8 is a schematic SEM diagram 2 of the modified shell powder of the present invention.

Detailed ways

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the preparation method of the modified shell of the present invention below will be described in detail with preferred embodiments and accompanying drawings.

The modified shell powder preparation method of the present embodiment comprises the following specific steps:

(1) Mechanically pulverize the cleaned shells, add an appropriate amount of water to make a mortar-like substance, filter through a 400-mesh filter, and then dry at medium and low temperatures to make shell powder;

(2) The shell powder is mixed with water at normal temperature to prepare a shell powder slurry, under the low-speed dispersion condition of an electric mixer, slowly add dilute phosphoric acid to the shell powder slurry while stirring in proportion, after the dropwise addition is completed , continue to stir for 30 to 60 minutes to make it fully react, after the reaction is completed, filter, dry, and disperse to obtain inorganic acid modified biological calcium carbonate;

(3) After drying the shell powder initially modified by phosphoric acid dissolution at low temperature, make a slurry with a mass fraction of 5%, and then add an organic modifier under stirring conditions, and the organic modifier is hard Calcium stearate, stearic acid, γ-aminopropyltriethoxysilane, γ-(2,3-glycidoxy)propyltrimethoxysilane, isopropyltrioleyloxytitanate , one of chelating titanate coupling agents, aluminate coupling agents, low temperature drying. The organic modifier in step (2) can also be calcium stearate, stearic acid, gamma-aminopropyltriethoxysilane, gamma-(2,3-epoxypropoxy)propyltrimethoxy Silane, isopropyl trioleate acyloxy titanate, chelating titanate coupling agent, and aluminate coupling agent are mixed at a mass ratio of 1:1, and the addition amount is carbonic acid 0.1%-10% of calcium powder mass. The particle size of the shell powder obtained through the 400-mesh filter in the step (1) is about 10-50um, and the medium and low temperature is 60-100°C. In step (2), the mass content of the fine shell powder slurry is 5-30%, the mass of the phosphoric acid added dropwise is 5-30% of the mass of the shell fine powder, and the mass concentration of the dilute phosphoric acid solution is 5-40%. The low temperature in step (3) is less than or equal to 60°C.

As shown in Figures 1 to 8, the lower heating and drying temperature can effectively retain the organic groups in the shell powder and ensure the activity of the powder; by controlling the amount of inorganic acid, the reaction amount of the inorganic phase in the shell powder can be quantitatively controlled; The highly active calcium carbonate powder that can be applied to oily systems such as coatings is prepared by inorganic-organic composite modification such as acid etching and coupling grafting.

Figure 1 shows the effect of different modifiers on the oil absorption of powder; Figure 2 shows the effect of different modifiers on the sedimentation volume of 10p-zyb powder; Figure 3 shows the phase of shell powder before and after modification Analysis shows that the main chemical composition before and after modification is a mixture of calcite and aragonite, and the basic composition of calcium carbonate powder is still retained; Figure 4 to Figure 6 are the infrared spectra of shell powder before and after modification, as can be seen from the figure , the characteristic peaks of 1500cm ^-1 and 876cm ^-1 of carbonate minerals were retained before and after modification; comparing Figure 4 and Figure 5, it was found that a certain plateau appeared between 3000cm ^-1 and 2000cm ^-1 , indicating that the addition of phosphoric acid changed the The structure of the shell powder has achieved a certain modification effect; and the absorption peaks of methyl and methylene appeared at 2920cm ^-1 and 2840cm ^-1 after adding the coupling agent for modification, indicating that the coupling agent has been modified. It is firmly combined on the surface of the shell powder and has a modification effect. Figure 7 and Figure 8 are the SEM microscopic morphology of the modified shell powder. It can be seen from the figure that the modified powder contains flake and prismatic particles. The particle size of the flake particles is about 10 μm, and the powder surface is somewhat blurred. The edges and corners are unclear, which is caused by dilute phosphoric acid corroding part of the calcium carbonate on the surface of the shell nacre, making the surface rough. At the same time, the coupling agent is modified and coated on the surface of the powder, which is beneficial to the powder in coatings and resins. Dispersion effect and stability in oily systems.

In summary, the use of related materials and related technologies in the present invention has provided the preparation method with many advantages, such as quantitatively removing the calcium carbonate in the shell powder as required, so that the obtained modified calcium carbonate powder is Calcium carbonate and organic active ingredients are retained in the required ratio; and the activity of the powder can be increased through organic modifiers to maintain good dispersion and stability in the organic system. Therefore, the present invention has outstanding substantive features and remarkable progress.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. a kind of modification shell powder preparation method with good dispersion, it is characterised in that：Including step in detail below：

(1) shell after cleaning up is mechanically pulverized, suitable quantity of water is added, class mortar substance is made, and passes through 400 mesh Strainer filtering, it is then dry under middle low temperature, shell powder is made；

(2) add water to be configured to sea shell micropowder slurry at normal temperature the shell powder, disperse item in electric mixer low speed Under part, it is slowly added to phosphoric acid,diluted into sea shell micropowder slurry while stirring in proportion, after being added dropwise, continues 30~60 points of stirring Clock reacts it sufficiently, after reaction, through filtering, drying, breaks up up to inorganic acid modification biological calcium carbonate；

(3) slurry that mass fraction is 5% will be made after the tentatively modified conch meal body hypothermia of phosphoric acid corrosion is dry, with Organic modifiers are added under agitation afterwards, the organic modifiers are calcium stearate, stearic acid, three second of γ-aminopropyl Oxysilane, γ-(2,3- the third oxygen of epoxy) propyl trimethoxy silicane, three oleic acid acyloxy titanate esters of isopropyl, chelating type titanium One or both of acid esters coupling agent, aluminate coupling agent, low temperature drying.

2. the modification shell powder preparation method according to claim 1 with good dispersion, it is characterised in that：Step (2) organic modifiers in are calcium stearate, stearic acid, gamma-aminopropyl-triethoxy-silane, γ-(2,3- epoxies third Oxygen) propyl trimethoxy silicane, three oleic acid acyloxy titanate esters of isopropyl, chelating titanate coupling agent, aluminate coupling agent In two kinds in mass ratio 1:1 mixing composition, additive amount is respectively the 0.1%- of inorganic acid modification biological calcium carbonate quality 10%.

3. the modification shell powder preparation method according to claim 1 or 2 with good dispersion, it is characterised in that： It is about 10-50um by the shell diameter of particle that 400 mesh filter screens of the step (1) obtain, the middle low temperature is 60- 100℃。

4. the modification shell powder preparation method according to claim 3 with good dispersion, it is characterised in that：It is described The step of (2) in the mass content of sea shell micropowder slurry be 5~30%, the quality of the phosphoric acid being added dropwise is sea shell micropowder quality 5~30%, the mass concentration of dilute phosphoric acid solution is 5~40%.

5. the modification shell powder preparation method according to claim 4 with good dispersion, it is characterised in that：It is described The step of (3) in low temperature be less than or equal to 60 DEG C.