KR101893583B1 - Method for preparing large size polymer particle with reduced scale - Google Patents

Abstract

(A) mixing 0.1 to 0.5 parts by weight of an electrolyte aqueous solution with 100 parts by weight of small-diameter polymer particles having an average particle size of 150 nm or less; And (b) 0.5 to 2 parts by weight of an aqueous acid solution is further mixed with the product of step (a) to aggregate the small-diameter polymer particles.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a large-diameter polymer particle having reduced scale,

More particularly, the present invention relates to a method for producing a large diameter polymer particle in which the uniformity of the particle distribution is improved and the scale is reduced in scale.

Most polymers are produced in particulate form through emulsion polymerization or solution polymerization. For example, polybutadiene, acrylonitrile-butadiene-styrene copolymer (hereinafter abbreviated as ABS resin), polystyrene-butadiene copolymer and the like are prepared by emulsion-polymerizing monomers such as dienes, styrene and / or acrylonitrile, nm) particle size. Korean Patent Laid-Open No. 10-2006-0052403 and Korean Laid-Open Patent No. 10-2008-0093137 disclose techniques related thereto.

Generally, the polymer particles prepared through polymerization have a small diameter of about 100 nm or less. Polymer particles have different physical properties depending on size and particle size distribution. For example, when the size of polybutadiene particles, ABS resin particles, or the like is small, impact resistance and the like are lowered, and it is known that they have excellent physical properties at a size of usually 300 nm or more.

Accordingly, a technique for producing large diameter polymer particles has been proposed. Korean Patent Laid-Open No. 10-2015-0015848 discloses a technique of making large-diameter polymer particles by enlarging small-diameter polymer particles, but it is known that the stability of the latex is improved by directly treating the small- There is a problem that the yield and productivity of the large diameter polymer particles are deteriorated due to the generation of a large amount of scale.

KR 10-2006-0052403 A KR 10-2008-0093137 A KR 10-2015-0015848 A

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method for manufacturing large diameter polymer particles, which can improve the productivity and yield by reducing the amount of scales generated while the particle size distribution is uniform.

(A) mixing 0.1 to 0.5 parts by weight of an electrolyte aqueous solution with 100 parts by weight of small-diameter polymer particles having an average particle size of 150 nm or less; And (b) 0.5 to 2 parts by weight of an aqueous acid solution is further mixed with the product of step (a) to aggregate the small-diameter polymer particles.

In one embodiment, the polymer is selected from the group consisting of polybutadiene, acrylonitrile-butadiene-styrene copolymer, polystyrene-butadiene copolymer, polyacrylonitrile-butadiene copolymer, polyacrylonitrile- Polybutyl acrylate, polystyrene, and polystyrene.

In one embodiment, the concentration of the aqueous electrolyte solution may be 1 to 5 wt%.

In one embodiment, the electrolyte is _{NaCl, Na 2 SO 4, NaHCO} 3, NaHSO 3, Na 2 CO 3, Na 4 P 2 O 7, Na 3 PO 4, Na 2 HPO 4, KCl, KHCO 3, KHSO ₃ , K ₂ CO ₃ , K ₄ P ₂ O ₇ , K ₃ PO ₄ , and K ₂ HPO ₄ .

In one embodiment, the concentration of the acid aqueous solution may be 1 to 5 wt%.

In one embodiment, the acid may be at least one selected from the group consisting of acetic acid, maleic acid, fumaric acid, itaconic acid, sulfuric acid, hydrochloric acid, nitric acid, and sulfonic acid.

In one embodiment, the average particle size of the aggregated polymer particles may be at least 300 nm.

In one embodiment, the step (b) may further include adding an alkali substance.

In one embodiment, the alkali substance may be at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, magnesium hydroxide, and ammonium hydroxide.

According to an aspect of the present invention, a large amount of polymer particles having a uniform particle size distribution can be easily manufactured by a simple method by sequentially mixing a small amount of an electrolyte and an acid to small-diameter polymer particles. In addition, the yield of large-diameter polymer particles and the productivity can be improved by reducing the amount of scale generated during manufacture.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

FIG. 1 illustrates a method of manufacturing a large diameter polymer particle according to an embodiment of the present invention.
FIG. 2 is a graphical representation of particle size analysis results of the large diameter polymer particles prepared according to Examples and Comparative Examples of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates a method of manufacturing a large diameter polymer particle according to an embodiment of the present invention.

Referring to FIG. 1, a method for preparing a large diameter polymer particle according to an aspect of the present invention includes the steps of: (a) mixing 0.1 to 0.5 parts by weight of an electrolyte aqueous solution with 100 parts by weight of small diameter polymer particles having an average particle size of 150 nm or less; And (b) further mixing 0.5 to 2 parts by weight of an aqueous acid solution with the product of step (a), thereby aggregating the small-diameter polymer particles.

As used herein, the terms "small diameter" and "large diameter" have relative meanings. Small diameter refers to the size of the polymer particles before agglomeration, i.e., in (a) That is, the size of the polymer particles obtained in the step (b).

The size range of the small diameter and the large diameter is not particularly limited. The kind of the polymer, the polymerization method, and the like, but the small diameter may have an average particle size of 50 to 150 nm, preferably 90 to 110 nm. The large diameter may have an average particle size of 300 nm or more, preferably 300 to 500 nm.

In the step (a), the small-diameter polymer particles are prepared by a conventional emulsion polymerization process or a solution polymerization process, and may be dispersed in a liquid phase. The small-diameter polymer particle dispersion may be selected from those having a content of polymer particles (solid content) of 5 to 80% by weight, preferably 10 to 50% by weight. The remaining amount in the dispersion may include water, a solvent, an emulsifier, etc. used in the emulsion polymerization process or the solution polymerization process.

The polymer may be selected from the group consisting of polybutadiene, acrylonitrile-butadiene-styrene copolymer, polystyrene-butadiene copolymer, polyacrylonitrile-butadiene copolymer, polyacrylonitrile- styrene copolymer, polyacrylate, polybutyl acrylate, Polystyrene, but are not limited thereto.

The small diameter polymer particles are negatively charged. At this time, a cation layer is formed around the negative charge existing on the surface of the small-diameter polymer particles, and the anion layer is strongly bonded around the cation layer to form a fixed layer. This fixed layer is called an electric double layer double layer).

The thickness of the electric double layer is a factor that has a decisive influence on the dispersion stability and cohesion of the particles, and when the electric double layer is not removed and maintained at a constant thickness, the small diameter polymer particles can maintain stable dispersibility without aggregation . When the electric double layer is removed, the polymer particles coagulate and the average particle size increases, and the polymer particles may become larger.

The negative charge can be removed by an acid. However, when the acid is directly treated on the surface of the polymer particles, the particles can be agglomerated and enlarged to a required particle size, while the dispersion stability of the particles is rapidly lowered, and a large amount of scale may be generated during agglomeration and non-agglomeration.

The electrolyte can be prepared by compressing the electric double layer, that is, by thinning the thickness of the electric double layer, by providing an excess amount of cation around the surface of the small diameter polymer particles in the stage before the acid treatment, It is possible to buffer or alleviate the problem of stability degradation, and the amount of scale generated after the process can be remarkably reduced.

In the electrolyte is _{NaCl, Na 2 SO 4, NaHCO} 3, NaHSO 3, Na 2 CO 3, Na 4 P 2 O 7, Na 3 PO 4, Na 2 HPO 4, KCl, KHCO 3, KHSO 3, K 2 CO ₃ , K ₄ P ₂ O ₇ , K ₃ PO ₄ , and K ₂ HPO ₄ may be used, but the present invention is not limited thereto. The electrolyte may be used in a liquid phase mixed with at least one solvent selected from water or an organic solvent, and preferably used as an aqueous liquid mixed with water.

The concentration of the electrolyte aqueous solution may be 1 to 5% by weight, and the amount of the aqueous electrolyte solution may be 0.1 to 0.5% by weight based on 100 parts by weight of the small diameter polymer particles. If the concentration and the dosage of the aqueous electrolyte solution are out of the above range, the particle size of the small-diameter polymer particles may become excessively large, and the uniformity of the particle size distribution may be reduced and a large scale may be generated.

Specifically, if the amount of the aqueous electrolyte solution is less than 0.1 parts by weight, the effect of cohesion buffering on small diameter polymer particles may be insufficient. If the amount of the electrolyte solution is more than 0.5 parts by weight, the thickness of the negative charge layer becomes excessively thin, Can be degraded.

In the step (b), the small-diameter polymer particles may be agglomerated to produce large-diameter polymer particles by further mixing a predetermined amount of an acid aqueous solution. For example, large diameter polymer particles can be generated immediately after mixing, within 1 minute, within 40 seconds, within 20 seconds, or within 10 seconds. Accordingly, the mixing time may be 1 minute or less, preferably 1 second to 1 minute.

The acid can effectively remove the negative charge on the surface of the small-diameter polymer particles by lowering the pH of the solution. That is, the acid has a function as a negative charge removing agent or a particle decarboxylator for the small-diameter polymer particles, and the small-diameter polymer particles can be removed by agglomerating the small-thickness polymer particles through the step (a) .

As described above, in the step (b), since the acid is treated in a state in which the negative charge on the surface of the small-diameter polymer particles is not completely removed, that is, the dispersion stability is maintained, It is possible to reduce the rapid agglomeration among the particles which may occur during the treatment and the excessive scale which is generated thereby.

The acid may be at least one selected from the group consisting of acetic acid, maleic acid, fumaric acid, itaconic acid, sulfuric acid, hydrochloric acid, nitric acid, and sulfonic acid, but is not limited thereto. The acid may be used in a liquid phase mixed with at least one solvent selected from water or an organic solvent, and preferably used as an aqueous liquid mixed with water.

The concentration of the acid aqueous solution may be 1 to 5% by weight, and the amount of the acid aqueous solution may be 0.5 to 2 parts by weight based on 100 parts by weight of the small diameter polymer particles. Particularly, when the amount of the acid aqueous solution is less than 0.5 parts by weight, the small-diameter polymer particles can not be enlarged to a level necessary for securing the physical properties. If the amount is more than 2.0 parts by weight, some particles become excessively large, A large amount of scale can occur at this time.

If an acid is used in the step (b), it may further include a neutralization step for neutralizing the acid. If the acid remains in the mixed solution obtained in the step (b), the property of the large diameter polymer particle may be adversely affected or the solution may become unstable. Therefore, it is preferable to neutralize the mixed solution by adding an alkali substance.

The alkali substance may be at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, magnesium hydroxide, and ammonium hydroxide, but is not limited thereto. The alkali substance may be added in a liquid state by mixing with a solvent such as water. The amount of the alkali substance to be added may be sufficient to neutralize the mixed solution according to the amount of the acid used in the step (b).

Hereinafter, embodiments of the present invention will be described in detail.

Example  One

270 parts by weight (solid content: 100 parts by weight) of a dispersion of polybutadiene particles having an average particle size of 95 nm and a solid content of 37% by weight and 0.2 parts by weight of a 2.5% by weight Na ₂ SO ₄ aqueous solution were mixed and mixed in the reactor. 1.0 part by weight of a 3.0 wt% aqueous solution of H ₃ PO ₄ was added dropwise thereto over 1 minute, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Example  2

The reactor have an average particle size of 95nm, and mixed after the administration of the solid content 37% by weight of polybutadiene particle dispersion 270 parts by weight (solid content 100 parts by weight) and 2.5% by weight of Na ₂ SO ₄ aqueous solution of 0.1 parts by weight. 1.0 part by weight of a 3.0 wt% aqueous solution of H ₃ PO ₄ was added dropwise thereto over 1 minute, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Example  3

The reactor have an average particle size of 95nm, and mixed after the administration of the solid content 37% by weight of polybutadiene particle dispersion 270 parts by weight (solid content 100 parts by weight) and 2.5% by weight of Na ₂ SO ₄ aqueous solution of 0.5 parts by weight. 1.0 part by weight of a 3.0 wt% aqueous solution of H ₃ PO ₄ was added dropwise thereto over 1 minute, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Example  4

270 parts by weight (solid content: 100 parts by weight) of a dispersion of polybutadiene particles having an average particle size of 95 nm and a solid content of 37% by weight and 0.2 parts by weight of a 2.5% by weight Na ₂ SO ₄ aqueous solution were mixed and mixed in the reactor. Then, 0.5 part by weight of a 3.0 wt% aqueous solution of H ₃ PO ₄ was added dropwise over 1 minute, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Example  5

270 parts by weight (solid content: 100 parts by weight) of a dispersion of polybutadiene particles having an average particle size of 95 nm and a solid content of 37% by weight and 0.2 parts by weight of a 2.5% by weight Na ₂ SO ₄ aqueous solution were mixed and mixed in the reactor. 2.0 parts by weight of a 3.0 wt% aqueous solution of H ₃ PO ₄ was added dropwise thereto for 1 minute, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Comparative Example  One

270 parts by weight (solid content: 100 parts by weight) of a dispersion of polybutadiene particles having an average particle size of 95 nm and a solid content of 37% by weight and 1.0 part by weight of an aqueous solution of 3.0% by weight of H ₃ PO ₄ were added dropwise to the reactor for 1 minute, And neutralized with an aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Comparative Example  2

A mean particle size of 95nm to the reactor and were mixed and then the solid content is administered 37% by weight of polybutadiene particle dispersion 270 parts by weight (parts solid content of 100 parts by weight) and 2.5% by weight of Na ₂ SO ₄ aqueous solution of 0.2 parts by weight, in this KOH solution And neutralized to obtain a polyvalent polybutadiene particle dispersion.

Comparative Example  3

The reactor have an average particle size of 95nm, and mixed after the administration of the solid content 37% by weight of polybutadiene particle dispersion 270 parts by weight (solid content 100 parts by weight) and 2.5% by weight of Na ₂ SO ₄ aqueous solution of 0.7 parts by weight. 1.0 part by weight of a 3.0 wt% aqueous solution of H ₃ PO ₄ was added dropwise thereto over 1 minute, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Comparative Example  4

270 parts by weight (solid content: 100 parts by weight) of a dispersion of polybutadiene particles having an average particle size of 95 nm and a solid content of 37% by weight and 0.2 parts by weight of a 2.5% by weight Na ₂ SO ₄ aqueous solution were mixed and mixed in the reactor. Then, 3.0 parts by weight of 3.0 wt% aqueous H ₃ PO ₄ solution was added dropwise thereto for 1 minute while being added dropwise, and the mixture was neutralized with a KOH aqueous solution to obtain an enlarged polybutadiene particle dispersion.

Experimental Example

The average particle size and polydispersity index (PDI) of the non-oriented polybutadiene particles according to the Examples and Comparative Examples were analyzed using a particle size analyzer (Microtrac, nanotrac 150). PDI is an index indicating the range of particle size distribution, and the smaller the value is, the more uniform the particle size distribution is.

In addition, the amount of scale produced inside the reactor after the process was measured based on the dose (based on solid content) of the polybutadiene particles. The above analysis and measurement results are shown in Table 1 and FIG.

division Example
One Example
2 Example
3 Example
4 Example
5 Comparative Example
One Comparative Example
2 Comparative Example
3 Comparative Example
4 Polybutadiene
(Parts by weight, solid content) 100 100 100 100 100 100 100 100 100 Na ₂ SO ₄
(Parts by weight, aq) 0.2 0.1 0.5 0.2 0.2 - 0.2 0.7 0.2 H ₃ PO ₄
(Parts by weight, aq) 1.0 1.0 1.0 0.5 2.0 1.0 - 1.0 3.0 Average particle size
(nm) 344 326 334 329 351 339 103 356 395 PDI 0.122 0.142 0.184 0.137 0.191 0.355 0.157 0.551 0.602 scale
(weight%) 0.030 0.031 0.029 0.028 0.035 0.150 0.010 0.350 0.410

Referring to Table 1 and FIG. 2, in Examples 1 to 5, it was found that the particle size distribution was uniform in comparison with Comparative Examples 1, 3, and 4, with PDIs ranging from 0.122 to 0.191, . In addition, the amount of generation of scale was 0.028 to 0.035% by weight based on the amount of the polybutadiene particles (based on the solid content), which was significantly reduced compared to Comparative Examples 1, 3 and 4 (0.150 to 0.410% by weight).

Specifically, the uniformity of the particle size distribution was remarkably improved in comparison with Comparative Example 1 in which the electrolyte Na ₂ SO _{4 -} was not used and Comparative Examples 3 and 4 in which the electrolyte and the antioxidant were used in an excessive amount, It is expected that the reliability and productivity of products will be improved.

On the other hand, in the case of Comparative Example 2 in which no antioxidant was used at all, it was found that aggregation of the polybutadiene particles initially injected hardly occurred, and physical characteristics due to particle enlargement can not be achieved.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (5)

(a) 0.1 to 0.5 parts by weight of an Na ₂ SO ₄ aqueous solution having a concentration of 1 to 5% by weight is mixed with 100 parts by weight of small-diameter polymer particles having an average particle size of 150 nm or less to decrease the thickness of the electric double layer on the surface of the small- ; And
(b) 0.5 to 2 parts by weight of an aqueous phosphoric acid solution having a concentration of 1 to 5% by weight is further added to the product of the step (a) to remove the electric double layer, and after the small diameter polymer particles are agglomerated, To produce large diameter polymer particles having an average particle size of 300 nm to 351 nm and a particle size distribution of 0.122 to 0.191. The method according to claim 1,
Wherein the polymer is at least one selected from the group consisting of polybutadiene, acrylonitrile-butadiene-styrene copolymer, polystyrene-butadiene copolymer, polyacrylonitrile-butadiene copolymer, polyacrylonitrile-styrene copolymer, polyacrylate, polybutyl acrylate, Polystyrene. ≪ RTI ID = 0.0 > 11. < / RTI > delete delete The method according to claim 1,
Wherein the alkali substance is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, magnesium hydroxide, and ammonium hydroxide.

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