CN105348446A - Preparation method of polystyrene/butyl acrylate-based composite core-shell emulsion and method for preparing high-hardness latex film of polystyrene/butyl acrylate composite core-shell emulsion - Google Patents

Abstract

A preparation method of a polystyrene/butyl acrylate-based composite core-shell emulsion and a high-hardness latex film thereof belong to the field of core-shell structure emulsions. The invention aims to solve the defects of low tensile strength, poor hardness and poor mechanical properties of the styrene-acrylic emulsion film. Preparation method: Prepare the St/BA core emulsion; then maintain the temperature of the St/BA core emulsion at 80-85°C, add the shell monomer dropwise, and at the same time add the remaining hair agent aqueous solution in equal amounts in batches at equal time intervals, and wait for the shell monomer to After the dropwise addition is completed, immediately add the functional monomer dropwise. After the dropwise addition of the functional monomer is completed, heat up, keep the temperature for 30-60min, cool to room temperature, and filter out the material. The preparation method of the latex film is as follows: take the polystyrene/butyl acrylate-based composite core-shell emulsion prepared by the above method, add an ionic complexing agent, stir evenly, flatten the bottom of the concave glass vessel, and dry at room temperature. The invention is applied in various fields such as construction, surface sizing agent, papermaking, coating, adhesive and the like.

Description

A preparation method of polystyrene/butyl acrylate-based composite core-shell emulsion and a preparation method of high-hardness latex film

technical field

The invention belongs to the field of core-shell structure emulsion.

Background technique

Styrene-acrylic emulsion is the product of emulsion polymerization of styrene and acrylate. In recent years, styrene-acrylic emulsions have become more and more important in many fields, such as construction, surface sizing agents, papermaking, coatings, adhesives, etc. Styrene-acrylic emulsion has certain advantages in color retention, light resistance, weather resistance, oxidation resistance, and ultraviolet radiation resistance, but has problems such as low tensile strength, brittleness at low temperature, and stickiness at high temperature, which limits its application.

How to improve the low tensile strength and poor mechanical properties of conventional styrene-acrylic films is a key issue in the preparation of styrene-acrylic emulsions. Recently, great breakthroughs have been made in the research on the modification of styrene-acrylic emulsions. For example, some itaconic acid and other functional monomers with carboxyl groups are added during the emulsion preparation process, so that the surface of the latex has carboxyl groups, and some cross-linking agents are added during the curing process, so that certain cross-linking occurs during the emulsion curing process. , thereby improving the performance of the film. However, simply introducing functional groups or adding some special cross-linking agents can only increase the performance of the latex film in a certain aspect.

Contents of the invention

The present invention aims to solve the defects of low tensile strength, poor hardness and poor mechanical properties of the styrene-acrylic emulsion film. The present invention realizes the Efficient synergy of different components. At the same time, some characteristic functional groups are introduced in the preparation process to achieve post-curing effect on the film and increase the degree of crosslinking of the film, thereby greatly improving the tensile strength, hardness and mechanical properties of the latex film under the synergy of internal and external effects. performance etc.

The present invention prepares a kind of small particle size and uniformly dispersed multi-component core-shell structure styrene-acrylic emulsion by semi-continuous seed emulsion polymerization method, and through the addition of ionic complexing agent, it has better tensile strength and high hardness. , a film with good mechanical properties, thereby further improving the performance of the styrene-acrylic emulsion and its film, and expanding its application range.

A kind of preparation method of polystyrene/butyl acrylate base composite core-shell emulsion among the present invention is carried out according to the following steps:

Step 1, based on the total monomer weight of the reaction, the mass percentage proportioning of raw materials is as follows:

Deionized water: 130% to 170%

Butyl Acrylate (BA): 30%～45%

Styrene (St): 20% to 50%

Methyl methacrylate (MMA): 0% to 35%

Functional monomer: 1.0%～4.0%

Composite emulsifier: 3% to 5%

Ammonium persulfate: 0.3%～0.6%

NaHCO ₃ : 0.3% to 0.8%;

Step 2, add the ammonium persulfate weighed in step 1 to the dehydrated ionized water that accounts for 20%-25% of the total mass of deionized water taken in step 1 to make an aqueous initiator solution, and styrene in step 1 is weighed and Weigh butyl acrylate with a total mass of 15%-25% of butyl acrylate and mix to obtain mixed monomer A, and mix the remaining butyl acrylate with the methyl methacrylate weighed in step 1 to configure a shell monomer;

Step 3: Add step 1 to the remaining deionized water, weigh NaHCO ₃ and compound emulsifier, heat up to 55-65°C, stir for 10-20min, add 10% to 20% of the total mass of mixed monomer A configured in step 2 (As a seed monomer) mix monomer A, pre-emulsify for 30 minutes, add an initiator aqueous solution accounting for 10% to 20% of the total mass of the initiator aqueous solution configured in step 2, heat up to 70-80°C, and react for 25-35 minutes to obtain Seed emulsion, then control the temperature of the seed emulsion at 70-80°C, then add the remaining mixed monomer A drop by drop (control the drop rate at 0.2ml/min～0.6ml/min), and divide it into four equal batches at the same time Add the initiator aqueous solution at equal time intervals to ensure that the mixed monomer A is added dropwise within 2 hours, and finally the St/BA nuclear emulsion is obtained;

Step 4. Maintain the reaction temperature of the St/BA core emulsion prepared in step 3 at 80-85°C, add the shell monomer dropwise to the core emulsion at a rate of 0.4ml/min to 1.0ml/min, and divide it into six parts at the same time. Add the remaining initiator aqueous solution in batches of equal time intervals. After the addition of the shell monomer is completed, immediately add the functional monomer dropwise at the same rate of addition of the shell monomer. After the addition of the functional monomer ( The dropwise addition time is 3h), the temperature is raised to 85-95°C, the temperature is kept for 30-60min, cooled to room temperature, and the material is filtered to obtain a polystyrene/butyl acrylate-based composite core-shell emulsion;

In step 3, add the initiator aqueous solution for the first time when starting to drop the mixed monomer A, and then add it every half an hour. The total amount of the initiator aqueous solution is 30% to 40% of the total mass of the initiator aqueous solution configured in step 2 %;

In step 4, the aqueous solution of the initiator is added for the first time when the dropwise addition of the shell monomer is started, and then added every half hour thereafter.

The composite emulsifier described in step 1 is formed by mixing emulsifier OP-10 and sodium dodecylsulfonate SDS according to the mass ratio of (1-2): (1-3).

The functional monomer described in step 1 is a carboxyl-containing olefinic monomer, and acrylic acid or methacrylic acid can be selected.

The preparation method of polystyrene/butyl acrylate based composite core-shell emulsion high-hardness latex film among the present invention is carried out as follows: get the polystyrene/butyl acrylate based composite core-shell emulsion prepared by the above method, then add Ionic complexing agent, stir evenly, flatten the bottom of concave glassware, and dry at room temperature for 24-48 hours to obtain a high-hardness latex film.

The molar ratio of the ionic complexing agent to the functional monomer in the polystyrene/butyl acrylate-based composite core-shell emulsion raw material is (0-0.5):1. The ionic complexing agent is ZnCl ₂ aqueous solution, hexamethylenediamine aqueous solution and CaCl ₂ aqueous solution.

The mass percent concentration of the ZnCl2 aqueous solution is 0.15%-0.45 _% , the mass percent concentration of the _CaCl2 aqueous solution is 0.20%-0.46%, and the mass percent concentration of the hexamethylenediamine aqueous solution is 0.14%-0.40%.

By adopting the method disclosed in the present invention, using styrene and butyl acrylate polymers as cores, methyl methacrylate and butyl acrylate as shells, and a small amount of acrylic acid as functional monomers, a tape with small particle size and uniform dispersion is successfully prepared. A core-shell type styrene-acrylic multi-component composite emulsion with special functional groups. On the premise of the basic properties of the original styrene-acrylic emulsion, the emulsion improves the uniform dispersion and rigidity of the particles to a large extent by adjusting the composition and proportion of the latex particles. At the same time, the addition of functional groups and complexing agents can greatly improve the hardness, transparency and water absorption of the latex film. Styrene-acrylic emulsion is an environmentally friendly, high-performance emulsion with simple preparation process, room temperature curing and low production cost. The multi-component core-shell type styrene-acrylic composite emulsion prepared by the present invention is non-toxic, has no release of harmful substances, has high latex film strength and low water absorption rate, and can be directly applied in construction, surface sizing agent, papermaking, coating, glue, etc. Adhesives and many other fields.

Compared with existing products, the multi-component core-shell type styrene-acrylic composite emulsion prepared by the method has the following advantages:

1. The strength of the latex film is high, and it is of great significance in the application of actual coatings;

2. The price of raw materials is low, and the preparation process is simple, which is extremely beneficial to actual production;

3. The latex particle size is uniform and the particle size distribution is narrow, which is extremely beneficial to the bonding performance and actual sizing;

4. The improvement of the performance of the multi-component core-shell type styrene-acrylic emulsion is conducive to the expansion of its application field and the expansion of the market;

5. The functionalization of multi-component core-shell styrene-acrylic emulsion is helpful for the application in the fields of special needs such as bonding and coating;

6. The emulsion is non-toxic, has no harmful gas release, and is an environmentally friendly product;

7. It can be cured at room temperature, and the use process is simple;

8. Directly used as water-based adhesives or coatings, etc., used in many fields such as construction, surface sizing agents, papermaking, coatings, and adhesives.

Description of drawings

Fig. 1 is the infrared spectrogram of styrene-acrylic composite emulsion (a does not contain MMA; bMMA content is 29%);

Fig. 2 is composite emulsion DSC curve;

Fig. 3 is the scanning electron microscope (SEM) figure of composite emulsion;

Fig. 4 is the latex particle size distribution of shell layer different MMA content, and 1-4 represent methyl methacrylate (MMA) mass percentage content respectively: 0%, 5%, 19%, 29%;

Fig. 5 is that MMA content is the composite emulsion emulsion sample picture of 29%;

Fig. 6 is that MMA content is the latex film film-forming picture of 29% composite emulsion emulsion without adding post-curing agent;

Fig. 7 is the film-forming picture of latex film after adding a certain amount of curing agent in the composite emulsion with MMA content of 29%.

detailed description

Specific embodiment one: the preparation method of a kind of polystyrene/butyl acrylate base composite core-shell emulsion in this embodiment is carried out according to the following steps:

Step 1, based on the total monomer amount of the reaction (i.e. based on the total mass of butyl acrylate, styrene, methyl methacrylate and functional monomers), the mass percentage ratio of raw materials is as follows:

Deionized water: 140%

Butyl Acrylate (BA): 30%

Styrene (St): 30%

Methyl methacrylate (MMA): 0%, 5%, 19% or 29%

Functional monomers: 2.5%

Complex emulsifier: 4%

Ammonium persulfate: 0.45%

NaHCO ₃ : 0.5%;

Step 2, add the ammonium persulfate taken in step 1 to the dehydrated ionized water which weighs 25% of the total mass of deionized water taken in step 1 to make an aqueous initiator solution, and the styrene taken in step 1 and the acrylic acid taken in step 1 20% of the total mass of butyl acrylate is mixed to obtain a mixed monomer A, and the remaining butyl acrylate is mixed with the methyl methacrylate weighed in step 1 to configure a shell monomer;

Step 3: Add step 1 to the remaining deionized water, weigh NaHCO ₃ and compound emulsifier, heat up to 60°C, stir for 20 minutes, add 16% of the total mass of the mixed monomer A configured in step 2 (as a seed monomer) and mix Monomer A, pre-emulsified for 30 minutes, adding an initiator aqueous solution accounting for 20% of the total mass of the initiator aqueous solution configured in step 2, raising the temperature to 75° C., and reacting for 30 minutes to prepare a seed emulsion, and then controlling the temperature of the seed emulsion at 75° C. Then add the remaining mixed monomer A drop by drop (the drop rate is controlled at 0.2ml/min～0.6ml/min), and add the initiator aqueous solution in four batches at equal intervals at the same time to ensure that the mixed monomer A is within 2h After the dropwise addition is completed, the St/BA nuclear emulsion is finally obtained;

Step 4. Maintain the reaction temperature of the St/BA core emulsion prepared in step 3 at 80°C, add the shell monomer dropwise to the core emulsion at a rate of 0.4ml/min, and add it in six batches at equal intervals For the remaining initiator aqueous solution, after the addition of the shell monomer is completed, immediately add the functional monomer dropwise at a rate of 0.4ml/min. to 95°C, keep warm for 45min, cool to room temperature, filter and discharge; the polystyrene/butyl acrylate-based composite core-shell emulsion is obtained;

In step 3, add the initiator aqueous solution for the first time when starting to drop the mixed monomer A, and then add it every half an hour. The total amount of the initiator aqueous solution is 25% of the total mass of the initiator aqueous solution configured in step 2;

In step 4, the aqueous solution of the initiator is added for the first time when the dropwise addition of the shell monomer is started, and then added every half hour thereafter.

The composite emulsifier described in step 1 is formed by mixing emulsifier OP-10 and sodium dodecylsulfonate SDS at a mass ratio of 1:3.

The functional monomer is acrylic acid.

Adopt the following experiments to verify the inventive effect.

The infrared spectrogram of styrene-acrylic composite emulsion is shown in Figure 1. It can be seen from Figure 1 that CH ₃ and CH ₂ stretch vibration absorption peaks appear at 2957.8cm ^-1 and 2929.6cm ^-1 ; there is C=O stretching vibration at 1728.4cm ^-1 Vibration absorption peak; 1452.0cm ^-1 is CH in-plane bending vibration absorption peak; there are obvious stretching vibration absorption peaks at 1242.1cm ^-1 , 1158.8cm ^-1 and 1064.4cm ^-1 which can be considered to be the top of BA, MMA and AA The superposition peak of CO; the characteristic absorption peak of butyl acrylate appeared at 961.9cm ^-1 ; the absorption peaks at 757.0cm ^-1 and 697.4cm ^-1 belonged to the characteristic absorption peaks of monosubstituted styrene. Figure 1 shows that styrene, butyl acrylate, acrylic acid and acrylic acid exist in the same system.

The core-shell polymer has two different glass transition temperatures (Tg) due to the different polymer compositions of the core layer and the shell layer. There is a difference in glass transition temperature, and the phenomenon of glass transition temperature migration will appear. Figure 2 is the DSC curve of the composite emulsion with the change of MMA content in the shell. It can be seen from Figure 2 that there are two obvious glass transition temperatures in the prepared composite emulsion, indicating that the prepared latex particles have obvious phase separation, which can indirectly prove that the prepared latex particles have a core-shell structure. Combined with the experimental preparation conditions, it can be determined that the two glass transition temperatures correspond to the styrene-butyl acrylate core layer polymer in the high temperature region and the butyl acrylate-methyl methacrylate shell polymer in the low temperature region, respectively.

The morphology of the samples was analyzed by scanning electron microscopy (SEM). Figure 3 shows the scanning electron micrograph of the complex emulsion diluted 10000 times. It can be seen from the figure that the latex particles of the composite emulsion have a spherical structure, uniform particle size, uniform dispersion, and no adhesion between the latex particles.

In order to further confirm the particle size of latex particles, the average particle size and particle size distribution of emulsion samples with different MMA contents were measured. Fig. 4 is the particle size distribution of latex particles with different MMA contents in the shell. It can be seen from Figure 4 that the particle size of the latex particles is uniform, showing a unimodal distribution, and the average particle size is 80-100nm. It can be seen from Figure 4 that when the MMA content is 0%, the average particle diameter of latex particles is about 80nm. With the increase of the amount of MMA in the shell layer, the particle size of latex particles increases gradually.

Figures 5-7 are emulsion samples and film formation pictures. Fig. 5 is the styrene-acrylic emulsion that the MMA content that makes is 29%, and the emulsion is white, slightly pan blue. Figure 6 and Figure 7 are the latex films prepared without curing agent and with curing agent, respectively. By comparison, it was found that the latex film prepared without curing agent was soft and poor in transparency; after adding a certain amount of curing agent, the transparency and hardness of the latex film were greatly improved.

The particle size and its distribution are measured by a dynamic mechanical light scattering instrument (DLS, Brookhaven, USA), and the sample needs to be diluted to 0.005-0.01 wt% before testing.

The hardness of the latex film is measured according to GB/T6739-2006 "Pencil Test Method for Coating Film Hardness".

The water absorption of latex film is measured according to ASTM D6015-14 standard. Take about 0.01g of a latex film sample, and completely immerse it in a 1000mL beaker filled with deionized water at a temperature of 23±2°C for 24 hours, then take out the immersion sample, and remove the surface moisture with absorbent paper before weighing. Suction. Each group had at least three samples. The specific calculation of water absorption is as follows:

Among them, W ₁ is the mass before water absorption, and W ₂ is the mass after water absorption.

The results are shown in Table 1

Table 1 Pencil hardness and water absorption of latex films with different MMA contents. It can be seen from Table 1 that as the MMA content increases, the pencil hardness of the latex film does not change significantly. When the MMA content exceeds 29%, the hardness of the latex film increases from 2B to B. With the increase of MMA content, the water absorption rate of the latex film changed obviously, and the water absorption rate showed a trend of decreasing gradually.

Table 1 Pencil hardness and water absorption of latex film with different MMA content changes

It can be seen from Table 1 that the particle size of the latex particles is small and the distribution is uniform. However, the water absorption rate of the latex film is relatively high, and the hardness of the latex film is poor.

Specific embodiment two: in the present embodiment, MMA monomer content is 29% (preparation method is referring to specifically mode one), and the specific preparation method of the latex film that adds the Zn of different content afterwards ^ions is as follows:

(1) Preparation of latex film

The preparation method of latex film is carried out as follows: get the polystyrene/butyl acrylate based composite core-shell emulsion that claims above-mentioned method preparation, add ^Zn then ionic complexing agent (specifically mass percent concentration is 0.38% ZnCl ₂ aqueous solution), stirred evenly, took out 7.5g and spread it on the bottom of the petri dish (surface area is 40cm ² ), dried at room temperature for 24h to obtain a latex film (thickness is about 400μm).

(2) Determination of properties of latex film

The hardness of the latex film is measured according to GB/T6739-2006 "Pencil Test Method for Coating Film Hardness".

The water absorption of latex film is measured according to ASTM D6015-14 standard. Take about 0.01g of a latex film sample, and completely immerse it in a 1000mL beaker filled with deionized water at a temperature of 23±2°C for 24 hours, then take out the immersion sample, and remove the surface moisture with absorbent paper before weighing. Suction. Each group had at least three samples. The specific calculation of water absorption is as follows:

Among them, W ₁ is the mass before water absorption, and W ₂ is the mass after water absorption.

The specific experimental results are shown in Table 2

Table 2

It can be seen from Table 2 that when Zn ²⁺ is not added as a post-curing accelerator, the hardness of the latex film is only B, and the water absorption rate is high. With the increase of Zn ²⁺ content, the hardness of the latex film gradually increases, reaching a maximum of 3H. The water absorption of latex film decreased gradually with the increase of Zn ²⁺ content.

Specific embodiment three: in the present embodiment, MMA monomer content is 29% (preparation method is referring to specifically mode one), the concrete preparation method of the latex film that adds the hexamethylenediamine of different content is as follows:

(1) Preparation of latex film

The preparation method of the latex film is carried out according to the following operations: take the polystyrene/butyl acrylate base composite core-shell emulsion prepared by the above-mentioned method of the claim, then add the hexamethylenediamine aqueous solution with a mass percentage concentration of 0.33%, stir evenly, 7.5 g was taken out and spread on the bottom of a petri dish (with a surface area of 40 cm ² ), and dried at room temperature for 24 hours to obtain a latex film (about 400 μm in thickness).

(2) Determination of properties of latex film

The hardness of the latex film is measured according to GB/T6739-2006 "Pencil Test Method for Coating Film Hardness".

The water absorption of latex film is measured according to ASTM D6015-14 standard. Take about 0.01g of a latex film sample, and completely immerse it in a 1000mL beaker filled with deionized water at a temperature of 23±2°C for 24 hours, then take out the immersion sample, and remove the surface moisture with absorbent paper before weighing. Suction. Each group had at least three samples. The specific calculation of water absorption is as follows:

Among them, W ₁ is the mass before water absorption, and W ₂ is the mass after water absorption.

The specific experimental results are shown in Table 3

table 3

It can be seen from Table 3 that when hexamethylenediamine is not added as a post-curing accelerator, the hardness of the latex film is only B, and the water absorption rate is high. With the increase of the content of hexamethylenediamine, the hardness of the latex film gradually increases, reaching a maximum of 2H. The water absorption of latex film decreased gradually with the increase of hexamethylenediamine content.

Specific embodiment four: in the present embodiment, MMA monomer content is 29% (preparation method is referring to specifically mode one), adds the CaCl of different content afterwards _The concrete preparation method of the latex film is as follows:

(1) Preparation of latex film

The preparation method of latex film is to carry out as follows: get the polystyrene/butyl acrylate base composite core-shell emulsion that claim above-mentioned method prepares, then add Ca ²⁺ ionic complexing agent (mass percentage concentration is 0.39% CaCl ₂ ), stirred evenly, took out 7.5g and spread it on the bottom of the petri dish (with a surface area of 40cm ² ), and dried it at room temperature for 24h to obtain a latex film (thickness about 400μm).

(2) Determination of properties of latex film

The hardness of the latex film is measured according to GB/T6739-2006 "Pencil Test Method for Coating Film Hardness".

The water absorption of latex film is measured according to ASTM D6015-14 standard. Take about 0.01g of a latex film sample, and completely immerse it in a 1000mL beaker filled with deionized water at a temperature of 23±2°C for 24 hours, then take out the immersion sample, and remove the surface moisture with absorbent paper before weighing. Suction. Each group had at least three samples. The specific calculation of water absorption is as follows:

Among them, W ₁ is the mass before water absorption, and W ₂ is the mass after water absorption.

The specific experimental results are shown in Table 4

Table 4

It can be seen from Table 4 that when Ca ²⁺ is not added as a post-curing accelerator, the hardness of the latex film is only B, and the water absorption rate is high. With the increase of Ca ²⁺ content, the hardness of the latex film gradually increases, and the maximum reaches 2H. The water absorption of latex film decreased gradually with the increase of Ca ²⁺ content.

Claims (10)

1. a preparation method for polystyrene/butyl acrylate base compound core-shell emulsion, is characterized in that this preparation method carries out in the steps below:

Step one, be benchmark by reaction total monomer amount, the mass percentage proportioning of raw material is as follows:

Deionized water: 130% ~ 170%

Butyl acrylate: 30% ~ 45%

Vinylbenzene: 20% ~ 50%

Methyl methacrylate: 0% ~ 35%

Functional monomer: 1.0% ~ 4.0%

Compound emulsifying agent: 3% ~ 5%

Ammonium persulphate: 0.3% ~ 0.6%

NaHCO ₃：0.3％～0.8％；

Step 2, step one taken ammonium persulphate and join and account for the ionized water that anhydrates that step one takes deionized water total mass 20%-25% and be made into initiator solution, step one is taken vinylbenzene and account for the butyl acrylate that step one takes butyl acrylate total mass 15%-25% and be mixed to get mix monomer A, the methyl methacrylate mixed configuration shell monomer remaining butyl acrylate and step one taken;

Step 3, in remaining deionized water, add step one take NaHCO ₃and compound emulsifying agent, be warming up to 55-65 DEG C, stir 10-20min, add 10% ~ 20% mix monomer A of the mix monomer A total mass of step 2 configuration, pre-emulsification 30min, add the initiator solution accounting for step 2 configuration initiator solution total mass 10% ~ 20%, be warming up to 70-80 DEG C, after reaction 25-35min, obtained seed emulsion, then the temperature of seed emulsion is controlled at 70-80 DEG C, dropwise drip remaining mix monomer A again, equivalent constant duration adds initiator solution in four batches simultaneously, guarantee that mix monomer A dropwises in 2h, final obtained St/BA core emulsion,

Step 4, St/BA core emulsion temperature of reaction obtained for step 3 is maintained 80-85 DEG C, in core emulsion, shell monomer is dripped with the drop rate of 0.4ml/min ~ 1.0ml/min, equivalent constant duration adds remaining initiator solution in six batches simultaneously, after shell monomer dropwises, drip functional monomer, after standby function monomer dropping is complete to drip the identical drop rate of shell monomer at once, be warming up to 85-95 DEG C, insulation 30-60min, is cooled to room temperature, filters discharging; Namely polystyrene/butyl acrylate base compound core-shell emulsion is obtained;

In step 3, when starting to drip mix monomer A, first time adds initiator solution, adds once afterwards every half an hour, and total add-on of initiator solution is 30% ~ 40% of step 2 configuration initiator solution total mass;

In step 4, when starting to drip shell monomer, first time adds initiator solution, adds once afterwards every half an hour.

2. the preparation method of a kind of polystyrene according to claim 1/butyl acrylate base compound core-shell emulsion, it is characterized in that compound emulsifying agent described in step one be emulsifier op-10 and sodium laurylsulfonate SDS by (1 ~ 2): mixing of the mass ratio of (1 ~ 3).

3. the preparation method of a kind of polystyrene according to claim 1/butyl acrylate base compound core-shell emulsion, is characterized in that functional monomer described in step one is carboxylic olefin monomer.

4. the preparation method of a kind of polystyrene according to claim 3/butyl acrylate base compound core-shell emulsion, is characterized in that functional monomer is acrylic or methacrylic acid.

5. the preparation method of a kind of polystyrene according to claim 1/butyl acrylate base compound core-shell emulsion, is characterized in that

Be benchmark by reaction total monomer amount in step one, the mass percentage proportioning of raw material is as follows:

Deionized water: 140%

Butyl acrylate: 38%

Vinylbenzene: 30%

Methyl methacrylate: 5% ~ 29%

Functional monomer: 2.5%

Compound emulsifying agent: 4%

Ammonium persulphate: 0.45%

NaHCO ₃：0.5％。

6. the preparation method of a kind of polystyrene according to claim 5/butyl acrylate base compound core-shell emulsion, to it is characterized in that in step one by reaction total monomer amount being benchmark, methyl methacrylate is 19%.

7. the preparation method of a kind of polystyrene according to claim 5/butyl acrylate base compound core-shell emulsion, to it is characterized in that in step one by reaction total monomer amount being benchmark, methyl methacrylate is 29%.

8. the preparation method of polystyrene/butyl acrylate base compound core-shell emulsion high rigidity latex film, it is characterized in that the preparation method of polystyrene/butyl acrylate base compound core-shell emulsion high rigidity latex film is undertaken by following operation: get polystyrene/butyl acrylate base compound core-shell emulsion prepared by claim 1 method, then ionic complexing agent is added, stir, bottom tiling spill glassware, at room temperature dry 24 ~ 48h, namely obtains high rigidity latex film.

9. the preparation method of a kind of polystyrene according to claim 8/butyl acrylate base compound core-shell emulsion high rigidity latex film, is characterized in that the mol ratio of the function monomer in ionic complexing agent and polystyrene/butyl acrylate base compound nucleocapsid emulsion materials is for (0 ~ 0.5): 1.

10. the preparation method of a kind of polystyrene according to claim 8/butyl acrylate base compound core-shell emulsion high rigidity latex film, is characterized in that described ionic complexing agent is ZnCl ₂the aqueous solution, the hexanediamine aqueous solution and CaCl ₂the aqueous solution; Wherein ZnCl ₂the mass percent concentration of the aqueous solution is 0.15%-0.45%, CaCl ₂the mass percent concentration of the aqueous solution is 0.20%-0.46%, and the mass percent concentration of the hexanediamine aqueous solution is 0.14%-0.40%.