CN113337058A

CN113337058A - Premixed re-dispersed latex powder and preparation method thereof

Info

Publication number: CN113337058A
Application number: CN202110597651.3A
Authority: CN
Inventors: 张伟
Original assignee: Shandong Zhuojun Industrial Co ltd
Current assignee: Shandong Zhuojun Industrial Co ltd
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-09-03

Abstract

The premixed re-dispersed latex powder comprises the following raw materials in parts by weight: polypropylene glycol: 1-3 parts; emulsion: 30-50 parts; white carbon black: 3-5 parts of rubber powder, wherein the rubber powder is obtained by emulsion spray drying, and the white carbon black is added in the emulsion spray drying process. This application adopts polypropylene alcohol and white carbon black to carry out duplicate protection for redispersible rubber powder's stability is stronger, and owing to be wherein the white carbon black equipartition in earlier stage, does not have the puzzlement that needs later stage white carbon black evenly arranged.

Description

Premixed re-dispersed latex powder and preparation method thereof

Technical Field

The application relates to a premixed re-dispersible latex powder and a preparation method thereof.

Background

The redispersible emulsion powder is water-soluble redispersible powder which is divided into ethylene/vinyl acetate copolymer, vinyl acetate/vinyl versatate copolymer, acrylic acid copolymer and the like, and is prepared into powder adhesive after spray drying, and polyvinyl alcohol is used as protective colloid. The powder can be quickly redispersed into emulsion after contacting with water, and the redispersible emulsion powder has high binding capacity and unique properties, such as: water resistance, workability, heat insulation, and the like, and thus their application range is extremely wide. However, the existing re-dispersible latex powder is generally mixed with other components for use when re-dispersing, and when the white carbon black is mixed, because the white carbon black has strong adsorption capacity, the re-dispersibility of the white carbon black is difficult to guarantee because the uniformity of the white carbon black is difficult to guarantee when re-dispersing.

Disclosure of Invention

In order to solve the problems, the application provides a premixed type redispersed latex powder which comprises the following raw materials in parts by weight: polypropylene glycol: 1-3 parts; emulsion: 30-50 parts; white carbon black: 3-5 parts of rubber powder, wherein the rubber powder is obtained by emulsion spray drying, and the white carbon black is added in the emulsion spray drying process. This application adopts polypropylene alcohol and white carbon black to carry out duplicate protection for redispersible rubber powder's stability is stronger, and owing to be wherein the white carbon black equipartition in earlier stage, does not have the puzzlement that needs later stage white carbon black evenly arranged.

Preferably, the anti-caking agent is also included, and the mass portion is 0.4-1.

Preferably, the emulsion is an acrylic copolymer.

On the other hand, a method for preparing the premixed re-dispersible latex powder is also provided, which is characterized by comprising the following steps: the method comprises the following steps:

dissolving polypropylene glycol into water and heating to dissolve;

then adding the emulsion, and stirring to obtain a mixed solution;

and introducing the mixed solution into a spray dryer, and simultaneously introducing the white carbon black into the spray dryer under a negative pressure state, so that the emulsion and the white carbon black are mixed under a spray state. This application adopts emulsion and white carbon black to mix at the spraying state, and the mixed effect is fabulous, also can play certain isolated protective action to white carbon black, avoids taking place the reunion and the complex of self.

Preferably, the temperature of the white carbon black is 130-150 ℃.

Preferably, the temperature-rising dissolution is performed as follows: adding 8-10 times of water by mass of polypropylene alcohol into a dissolving kettle, and adding polyvinyl alcohol while stirring; and then heating the dissolving kettle to 80-90 ℃, and continuing stirring until the polyvinyl alcohol is completely dissolved to obtain the protective solution.

Preferably, the mixed solution is synthesized as follows: adding the emulsion into a mixing kettle, and slowly adding the protective solution into the emulsion under stirring to obtain a mixed solution.

Preferably, the spray dryer comprises a drying shell, a spray drying head is arranged in the drying shell, the spray drying head is communicated with a mixed liquid inlet pipe and a hot air inlet pipe, and the hot air inlet pipe is communicated with a white carbon black introducing pipe.

Preferably, a porous screen is arranged at the end part of the white carbon black introducing pipe and is communicated with the hot air introducing pipe.

Preferably, the outlet temperature of the hot air is 110-120 ℃.

This application can bring following beneficial effect:

1. the polypropylene glycol and the white carbon black are adopted for double protection, so that the stability of the redispersible rubber powder is higher, and the white carbon black is uniformly distributed in the earlier stage, so that the trouble that the white carbon black is uniformly distributed in the later stage does not exist;

2. this application adopts emulsion and white carbon black to mix at the spraying state, and the mixed effect is fabulous, also can play certain isolated protective action to white carbon black, avoids taking place the reunion and the complex of self.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic view of a spray dryer.

Detailed Description

In order to clearly explain the technical features of the present invention, the present application will be explained in detail by the following embodiments in combination with the accompanying drawings.

As shown in the drawings, the following detailed description is given by way of example in order to more clearly explain the overall concept of the present application.

In addition, in the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on those shown in the drawings, are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present application.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; the connection can be mechanical connection, electrical connection or communication; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In a first embodiment, as shown in fig. 1, the spray dryer of the present application is substantially an improvement over the existing spray dryer, and only a bypass is introduced to introduce white carbon black. The spray dryer comprises a drying shell 1, a spray drying head 2 is arranged in the drying shell 1, the spray drying head 2 is communicated with a mixed liquid inlet pipe 3 and a hot air inlet pipe 4, and the hot air inlet pipe 4 is communicated with a white carbon black introducing pipe 5. The end part of the white carbon black guiding pipe 5 is provided with a porous sieve 6 which is communicated with the hot air leading-in pipe 4.

The specific synthesis method comprises the following steps:

the performance of the latex powder needs to be characterized by the performance of the redispersible rubber powder, and the specific preparation comprises the following steps:

s1, dissolving polypropylene glycol into water, and heating to dissolve the polypropylene glycol; the temperature-rising dissolution is carried out as follows: adding 8-10 times of water by mass of polypropylene alcohol into a dissolving kettle, and adding polyvinyl alcohol while stirring; then heating the dissolving kettle to 80-90 ℃, and continuing stirring until the polyvinyl alcohol is completely dissolved to obtain a protective solution;

s2, then adding an emulsion which is an acrylic copolymer, and stirring to obtain a mixed solution; the mixed solution is synthesized as follows: adding the emulsion into a mixing kettle, and slowly adding the protective solution into the emulsion under stirring to obtain a mixed solution;

s3, introducing the mixed solution into a spray dryer for drying to obtain pure powder, and simultaneously introducing the white carbon black into the spray dryer under a negative pressure state, so that the emulsion and the white carbon black are mixed under a spray state; the introduction temperature of the white carbon black is 130-150 ℃; the temperature of the air outlet of the hot air is 110-120 ℃; specific operating parameters are shown in table 1.

Table 1:

s4, putting the pure powder, the coarse whiting and the corn starch into a mixing bin, stirring and mixing, and then filtering through a vibrating screen to obtain rubber powder, wherein the mass parts of all the components are shown in Table 2.

Table 2:

serial number	Temperature rise (. degree. C.) of the dissolution vessel	White carbon temperature (. degree. C.)	Outlet temperature of hot air (. degree. C.)
				1	80	130	110
2	90	150	120
				3	85	140	120
4	85	140	120

S5, performing redispersibility determination and anti-caking performance determination on the rubber powder:

measurement of redispersibility Properties the measurement was carried out as follows: adding 50g of latex powder into 50ml of water, fully wetting, then adding water to dilute until the solid content is 0.5%, uniformly stirring, pouring 100ml of the solution into a graduated test tube, and measuring the precipitation height of the solid in 24h and 48h respectively.

The anti-caking performance was determined as follows: the latex powder was introduced into an iron pipe having a threaded pipe and loaded with a metal plug. After application of the load, the tube was stored in a drying oven at 50 ℃ for 16h, after cooling to room temperature, the powder was taken out of the tube and the powder was compressed to determine its anti-caking properties. The anti-caking property is divided into the following four grades: 1. the anti-caking property is excellent; 2. the anti-caking property is good; 3. the anti-caking property is poor; 4. no anti-caking, the powder could not be crushed or after crushing no longer free-flowing. The performance index is shown in Table 3.

Table 3:

the above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A premixed re-dispersed latex powder is characterized in that: the composite material comprises the following raw materials in parts by weight: polypropylene glycol: 1-3 parts; emulsion: 30-50 parts; white carbon black: 3-5 parts of rubber powder, wherein the rubber powder is obtained by emulsion spray drying, and the white carbon black is added in the emulsion spray drying process.

2. The pre-mixed re-dispersible latex powder of claim 1, wherein: and the anti-caking agent is 0.4 to 1 part by mass.

3. The pre-mixed re-dispersible latex powder of claim 1, wherein: the emulsion is an acrylic copolymer.

4. A method for preparing the pre-mixed re-dispersible latex powder by using the raw materials of any one of claims 1 to 3, which is characterized in that: the method comprises the following steps:

dissolving polypropylene glycol into water and heating to dissolve;

then adding the emulsion, and stirring to obtain a mixed solution;

and introducing the mixed solution into a spray dryer, and simultaneously introducing the white carbon black into the spray dryer under a negative pressure state, so that the emulsion and the white carbon black are mixed under a spray state.

5. The preparation method of the premixed re-dispersible latex powder according to claim 4, wherein the method comprises the following steps: the temperature of the white carbon black is 130-150 ℃.

6. The preparation method of the premixed re-dispersible latex powder according to claim 4, wherein the method comprises the following steps: the temperature-rising dissolution is carried out as follows: adding 8-10 times of water by mass of polypropylene alcohol into a dissolving kettle, and adding polyvinyl alcohol while stirring; and then heating the dissolving kettle to 80-90 ℃, and continuing stirring until the polyvinyl alcohol is completely dissolved to obtain the protective solution.

7. The preparation method of the pre-mixed re-dispersible latex powder of claim 6, wherein the method comprises the following steps: the mixed solution is synthesized as follows: adding the emulsion into a mixing kettle, and slowly adding the protective solution into the emulsion under stirring to obtain a mixed solution.

8. The preparation method of the pre-mixed re-dispersible latex powder of claim 6, wherein the method comprises the following steps: the spray dryer comprises a drying shell, a spray drying head is arranged in the drying shell, the spray drying head is communicated with a mixed liquid inlet pipe and a hot air inlet pipe, and the hot air inlet pipe is communicated with a white carbon black introducing pipe.

9. The method for preparing the pre-mixed re-dispersible latex powder of claim 8, wherein the method comprises the following steps: the end part of the white carbon black guiding pipe is provided with a porous sieve communicated with the hot air inlet pipe.

10. The method for preparing the pre-mixed re-dispersible latex powder of claim 8, wherein the method comprises the following steps: the temperature of the air outlet of the hot air is 110-120 ℃.