CN112979880B - A kind of narrow dispersion graft copolymerization ABS composition and preparation method thereof - Google Patents

Abstract

The invention discloses a narrow dispersion graft copolymerization ABS composition and a preparation method thereof. The pre-emulsion fast feeding method is adopted to reduce the graft polymerization time and energy consumption; the alkaline solution is added dropwise to keep the basicity of the rubber lactic acid unchanged, and the aggregation of rubber particles is reduced. It is possible to obtain a narrow distribution of grafted rubber particles; adding ethylenically unsaturated carboxylate monomers as a good solvent for diene rubbers can effectively improve the final monomer conversion rate in the grafting process and reduce vinyl caused by rapid feeding. Residual amount of benzene monomers and vinyl cyanide monomers, reducing the influence of side reactions such as vinyl cyanide monomer cyclization on the apparent properties of ABS thermoplastic resin compositions, and at the same time the diffusion of ethylene unsaturated carboxylate monomers To the inside of the rubber particles, increase the internal grafting and make the inside of the rubber particles properly cross-linked, improve the dispersibility and toughening effect of the ABS graft copolymer in the matrix resin, and finally obtain a thermoplastic with good apparent properties and excellent impact resistance. resin composition.

Description

A kind of narrow dispersion graft copolymerization ABS composition and preparation method thereof

technical field

The invention belongs to the technical field of polymer materials, and in particular relates to an efficient preparation method of an ABS composition and a narrowly dispersed graft copolymer thereof.

Background technique

ABS resin is one of the representative works of human beings in the field of materials. It is widely used in the fields of household appliance shells and other fields due to its excellent mechanical properties and aesthetic properties. With the improvement of living standards, people's requirements for the aesthetics of daily necessities are also increasing, and the market's demand for the whiteness of household air conditioners and refrigerator shells is more obvious.

At present, the industrial methods for preparing ABS resin mainly include continuous bulk method and emulsion graft blending method. Although continuous bulk polymerization technology has been continuously developed in recent years, it has not been fully accepted by the market due to the immaturity of the process. At present, the mainstream ABS preparation technology is still the emulsion grafting-bulk SAN blending method. In this process, there will inevitably be monomer residues during the emulsion grafting process, which is one of the important reasons for the decrease in the whiteness of ABS resin. Therefore, improving the conversion rate of the grafting process and shortening the grafting time can directly improve product quality, reduce production costs, improve device efficiency, reduce production energy consumption and better protect the environment, which is of great social significance. At the same time, how to improve the grafting efficiency while maintaining the stable shape of the rubber particles is also crucial to make the ABS composition have good impact resistance.

Patent CN109071916A for reducing the content of useless residues in the graft emulsion in the prior art, by adding a phosphate ester reactive emulsifier that can be used as a metal passivator, thereby reducing the content of unnecessary residues, by phosphate ester reactive emulsification The agent improves the compatibility between the ABS graft copolymer and the aromatic vinyl compound-vinyl cyanide compound copolymer to improve the impact resistance of the ABS composition. The patent CN104693636 of improving the conversion rate of grafted polymer improves the conversion rate by adding bifunctional reactive monomers in the late stage of grafting. At the same time, it is limited to ethylene to obtain another double bond, which improves the reaction conversion rate and makes the inside of the rubber particles properly cross-linked. Appropriate cross-linking helps the rubber particles to maintain the best toughening shape and improve the dispersibility. This limitation is to reduce the devolatilization boiling point of the introduced monomer and reduce the energy consumption of devolatilization, liquid and gas removal. Existing patent CN105189588A has mentioned the preparation method of small particle size bimodal graft structure to improve the surface gloss of ABS resin composition, but various schemes in the prior art or the existence of complicated process, long grafting time and low conversion rate and other shortcomings, it is difficult to ensure industrial production.

Therefore, how to provide an emulsion grafting method with simple operation process, short grafting time, high grafting conversion rate and narrow dispersion of rubber particles is an urgent problem to be solved by those skilled in the art.

SUMMARY OF THE INVENTION

In view of this, the present invention provides an ABS graft copolymer with short grafting time, high graft conversion rate, and narrow dispersion of internal crosslinking, and utilizes the graft copolymer and matrix resin to melt blend to obtain whiteness. Excellent ABS composition with better impact performance.

To achieve the above object, the present invention adopts the following technical solutions:

A narrow dispersion graft copolymerization ABS composition, in parts by weight, comprising the following components: 40-60 parts of diene latex dry basis, 28.5-43 parts of vinylbenzene monomers, and vinyl cyanide monomers 11.5-17 parts, 3.5-5.15 parts of ethylenically unsaturated carboxylate monomer, 0.15-0.225 parts of lye dry basis, 0.4-0.6 part of emulsifier, 0.2-0.3 part of initiator, 0.5-0.75 part of redox system , 0.8 to 1.2 copies of antioxidants.

Preferably, the diene-based latex is one of polybutadiene-based latex and butadiene-styrene-based latex.

Preferably, the vinylbenzene-based monomer is one of styrene, methylstyrene, p-methylstyrene and vinyltoluene, preferably styrene.

Preferably, the vinyl cyanide monomer is acrylonitrile, methacrylonitrile or a mixture thereof, preferably acrylonitrile.

Preferably, the ethylenically unsaturated carboxylate monomer is one of methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate, preferably methyl methacrylate.

Preferably, the lye is one of sodium hydroxide and potassium hydroxide, preferably potassium hydroxide; the emulsifier is one of free alkyl aryl sulfonates, rosin acid alkyl salts, and fatty acid salts One or more, preferably potassium disproportionate rosinate soap, sodium lauryl sulfate; Described initiator is potassium persulfate, benzoyl peroxide, cumene hydrogen peroxide, di-tert-butyl peroxide , one or more of azobisisobutyronitrile, preferably cumene hydroperoxide.

Preferably, the redox system is a combination of perfructose, ferrous sulfate and sodium pyrophosphate or a combination of disodium EDTA, sodium formaldehyde sulfoxylate and ferrous sulfate, wherein The mass ratio of fructose, ferrous sulfate and sodium pyrophosphate is 10:4:1, and the mass ratio of formaldehyde sodium sulfoxylate, ferrous sulfate, and EDTA disodium salt is 10:4:1. The oxidant is antioxidant AO-8020, produced by Jilin Boyuxiangshi Industry and Trade Co., Ltd.

A kind of preparation method of narrow dispersion graft copolymerization ABS composition, comprises the following steps:

Step 1: Preparation of ABS Grafted Polymer

(1.1) 4/5 of the total amount of emulsifier, vinylbenzene monomer, vinyl cyanide monomer, initiator, and water are configured into pre-emulsion, for subsequent use;

(1.2) After the redox system is configured into an aqueous solution in proportion, it is added to the diene latex, and then the pre-emulsion is injected into the diene latex by dropwise feeding under the conditions of controlling the reaction temperature at 55-60°C and rotating speed of 300rpm. In the process, the feeding time is 50-70min, and at the same time, the lye solution with a mass concentration of 5%-10% is injected in the form of dropwise feeding to keep the pH of the reaction system between 9.4-9.7;

(1.3) be warming up to 70-75 ℃ after the feeding is completed, continue to inject the ethylenic unsaturated carboxylate monomer in the reaction system of step (1.2) by dripping feeding, the feeding time is 15-20min, After finishing feeding, add the remaining initiator, keep the temperature for 50min and then cool down to ≤60℃, then add antioxidant emulsion and mix evenly, add 0.3%-0.4% concentration of sulfuric acid aqueous solution and heat up to 85-95℃ for flocculation, then filter , washing and drying to obtain ABS grafted polymer;

Step 2: Preparation of Narrow Dispersion Graft Copolymerization ABS Composition

The ABS grafted polymer obtained in step 1 and the SAN matrix resin are blended with an extruder at 220° C. to obtain a narrowly dispersed graft copolymerized ABS composition.

Preferably, the weight ratio of vinylbenzene monomers and vinyl cyanide monomers in the pre-emulsion of step (1.1) is 2.5:1, and the ratio is the aromatic vinyl compound-vinyl cyanide in the ABS graft copolymer. The best compatibility ratio of compound copolymer.

Preferably, in step (1.3), the weight ratio of the amount of the ethylenically unsaturated carboxylic acid ester monomer to the vinyl cyanide monomer is 0.3:1, which can make the monomer conversion rate reach the maximum value and avoid the ethylenically unsaturated carboxylic acid. Ester monomers form unwanted polymers.

As can be seen from the above technical solutions, compared with the prior art, the present invention discloses and provides a narrow dispersion graft copolymerization ABS composition and a preparation method thereof. Compared with the introduction of the monomer feed into the oil phase, the pre-emulsion can be grafted with diene latex more quickly, shorten the grafting time, and improve the polymerization rate; the dropwise feeding method is used to feed the butanediene Injecting lye into the alkene latex to keep the pH of the latex unchanged, which can prevent side reactions such as aldehyde group oxidation and sulfite decomposition to reduce the pH value of the emulsion, ensure the complex reaction between ferrous ions and chelating agents, and avoid the reduction of the grafting reaction rate. , the pH is stabilized at 9.4-9.7 while preventing the hydroxyl coordination effect of metal ions caused by too high pH, which affects the graft polymerization rate; in the later stage of grafting, ethylenically unsaturated carboxylate monomers are injected into dienes in the same way In the latex, the double bond in the unsaturated carboxyl group is used, and another double bond is obtained by restricting it to ethylene, which improves the reaction conversion rate and makes the inside of the rubber particles properly cross-linked. , to improve the dispersibility, the esters are limited to reduce the devolatilization boiling point of the introduced monomer, and reduce the energy consumption of devolatilization, liquid and gas removal. The rubber particles of the finally obtained ABS graft copolymer have narrow distribution characteristics, the particle size difference is less than 100 nm, the final conversion rate of the latex after the graft polymerization is completed is more than 98%, and the final obtained ABS composition has a white apparent performance. The degree value is above 55, and the impact performance impact strength is above 200J/m.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

Fig. 1 is the transmission electron microscope picture of the ABS graft copolymer prepared in the embodiment of the present invention 1;

Fig. 2 is the transmission electron microscope picture of the ABS graft copolymer prepared in Comparative Example 2 of the present invention;

Fig. 3 is the transmission electron microscope picture of the ABS graft copolymer prepared in Comparative Example 3 of the present invention;

4 is a transmission electron microscope image of the ABS graft copolymer prepared in Comparative Example 4 of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

Step 1: Preparation of ABS Grafted Polymer

(1.1) In parts by weight, add 0.4 part of emulsifier sodium lauryl sulfate, 22.5 parts of deionized water, styrene and acrylonitrile monomers to a total of 40 parts, the ratio of styrene to acrylonitrile is 2.5/1, and 0.12 parts are Cumene hydrogen oxide, shake to become a pre-emulsion;

(1.2) Weigh 0.04 part of sodium pyrophosphate, 0.1 part of fructose, 0.01 part of ferrous sulfate, 5 parts of deionized water, 0.04 part of cumene hydrogen peroxide, dissolve and mix and place 60 parts of dry polybutadiene In the latex, the pre-emulsion was then injected into the polybutadiene latex by dropwise feeding under nitrogen protection under the condition of controlling the reaction temperature at 57° C. and the rotating speed of 300 rpm, and the feeding time was 60 min, and the feeding was carried out by dropwise feeding at the same time. A potassium hydroxide solution with a mass concentration of 5% was injected, wherein the number of potassium hydroxide was 0.15 parts, and the number of deionized water was 2.85 parts, and the pH of the reaction system was kept between 9.4-9.7;

(1.3) be warmed up to 74 ℃ after the feeding is completed, continue to inject 3.43 parts of ethylenically unsaturated carboxylate monomer methyl methacrylate in the reaction system of step (1.2) by dripping feeding, feeding Time 15min, add 0.04 part of cumene hydrogen peroxide after feeding, keep the temperature for 50min and then cool down to ≤60℃, then add 0.8 part of antioxidant AO-8020 and mix well, then add 0.4wt% concentration of sulfuric acid aqueous solution The temperature was raised to 93°C for flocculation for 5min, and then filtered, washed and dried to obtain ABS grafted polymer powder;

Step 2: Preparation of Narrow Dispersion Graft Copolymerization ABS Composition

The ABS grafted polymer powder prepared in step 1 and the styrene acrylonitrile copolymer are blended and extruded into granules in a weight ratio of 25:75 to finally obtain an ABS composition.

The conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Example 2

Step 1: Preparation of ABS Grafted Polymer

(1.1) In parts by weight, 0.6 part of emulsifier disproportionated potassium rosinate soap, 33.75 parts of deionized water, styrene and acrylonitrile monomers total 60 parts, the ratio of styrene to acrylonitrile is 2.5/1, 0.18 parts of peroxide Hydrogen cumene, shake to become a pre-emulsion;

(1.2) Weigh 0.06 part of sodium pyrophosphate, 0.15 part of fructose, 0.015 part of ferrous sulfate, 7.5 parts of deionized water, 0.06 part of cumene hydrogen peroxide, dissolve and mix and place 40 parts of dry polybutadiene In the latex, the pre-emulsion was injected into the polybutadiene latex by dropwise feeding under the conditions of controlling the reaction temperature at 57 ° C and the rotating speed at 300 rpm, and the feeding time was 60 min. % potassium hydroxide solution, wherein 0.225 parts of potassium hydroxide, 4.275 parts of deionized water, keep the pH of the reaction system between 9.4-9.7;

(1.3) be warmed up to 74 ℃ after the feeding is completed, continue to inject 5.15 parts of ethylenically unsaturated carboxylate monomer methyl methacrylate in the reaction system of step (1.2) by dripping feeding, feeding Time 15min, add 0.04 part of cumene hydroperoxide after feeding, keep the temperature for 50min and then cool down to ≤60°C, then add 0.8 part of antioxidant and mix evenly, add 0.4wt% concentration of sulfuric acid aqueous solution and heat up to 93 ℃ of flocculation for 5min, then filtered, washed and dried to obtain ABS grafted polymer powder;

Step 2: Preparation of Narrow Dispersion Graft Copolymerization ABS Composition

The ABS grafted polymer powder obtained in step 1 and the styrene acrylonitrile copolymer are blended and extruded and granulated according to a weight ratio of 37.5:62.5 to finally obtain an ABS composition.

The conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Comparative Example 1

The preparation process of the ABS graft copolymer is the same as that described in Example 1, the difference is that after the dropwise addition of the pre-emulsion is completed, the temperature rises to 74 ° C, and the ethylenically unsaturated carboxylate monomer methacrylic acid is not added. Methyl ester, the contents of other components are exactly the same as in Example 1, and the conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Comparative Example 2

The preparation procedure of the ABS graft copolymer was the same as described in Example 1, except that the 5% potassium hydroxide solution was discontinuously injected at the same time as the pre-emulsion feed. Instead, an equal number of potassium hydroxide solution was added to the ABS graft latex at the end of the reaction, and the contents of other components were exactly the same as those in Example 1. The conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Comparative Example 3

The preparation process of the ABS graft copolymer is the same as that described in Example 1, the difference is that 10% potassium hydroxide solution, 0.45 parts of potassium hydroxide and 4.275 parts of deionized water are continuously injected while the pre-emulsion is fed. , the PH value of the emulsion is maintained at around 12. The contents of other components are exactly the same as in Example 1. The conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Comparative Example 4

The preparation process of the ABS graft copolymer was the same as described in Example 1, except that the pre-emulsion feeding time was extended to 180 min. The contents of other components are exactly the same as in Example 1. The conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Comparative Example 5

The preparation process of the ABS graft copolymer was the same as described in Example 1, except that the reaction temperature was kept at 65°C during the pre-emulsion feed. The contents of other components are exactly the same as in Example 1. The conversion rate of the ABS graft copolymer, the whiteness value and the impact strength value of the ABS composition are listed in Table 1.

Table 1 Conversion rate of ABS graft copolymer and whiteness value and impact strength value of ABS composition

It can be seen from Table 1 and Figures 1-4 that the graft copolymer and composition prepared by the technical solution of the present invention have better properties.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. a preparation method of narrow dispersion graft copolymerization ABS composition, is characterized in that, comprises the following steps: Step 1: Preparation of ABS Grafted Polymer (1.1) 4/5 of the total amount of emulsifier, vinylbenzene monomer, vinyl cyanide monomer, initiator, and water are prepared into a pre-emulsion for use; (1.2) The reduction system is configured into an aqueous solution in proportion and added to the diene latex, and then the pre-emulsion is injected into the diene latex by dropwise feeding under the conditions of controlling the reaction temperature at 55-60°C and rotating speed of 300rpm. , the feeding time is 50-70min, and at the same time, the lye with the mass concentration of 5%-10% is injected into the solution by dropping the feed to keep the pH of the reaction system between 9.4-9.7; (1.3) After the feeding is completed, the temperature is raised to 70-75 °C, and the ethylene-based unsaturated carboxylate monomer is continuously injected into the reaction system of step (1.2) by dropwise feeding, and the feeding time is 15-20 min. After finishing feeding, add the remaining initiator, keep the temperature for 50min and then cool down to ≤60°C, then add antioxidant emulsion to mix evenly, add 0.3wt%-0.4wt% sulfuric acid aqueous solution and heat up to 85-95°C for flocculation, Then filter, wash and dry to obtain ABS grafted polymer; Step 2: Preparation of Narrow Dispersion Graft Copolymerization ABS Composition The ABS graft polymer obtained in step 1 is blended with the matrix resin at high temperature to obtain a narrowly dispersed graft copolymerized ABS composition; Wherein, the weight ratio of vinylbenzene monomers and vinyl cyanide monomers in the pre-emulsion in step (1.1) is 2.5:1, and the amount of vinyl unsaturated carboxylate monomers in step (1.3) is equal to that of vinyl cyanide monomers. The weight ratio of cyanide monomers is 0.3:1. 2. the preparation method of a kind of narrow dispersion graft copolymerization ABS composition according to claim 1, is characterized in that, in parts by weight, 40～60 parts of diene latex dry bases, vinylbenzene monomers 28.5~43 parts, vinyl cyanide monomers 11.5~17 parts, ethylene unsaturated carboxylate monomers 3.5~5.15 parts, lye dry basis 0.15~0.225 parts, emulsifier 0.4~0.6 parts, initiator 0.2 ~0.3 part, reduction system 0.5-0.75 part, antioxidant 0.8-1.2 part. 3. the preparation method of a kind of narrow dispersion graft copolymerization ABS composition according to claim 2, is characterized in that, described diene latex is in polybutadiene latex, butadiene-styrene latex a kind of. 4. the preparation method of a kind of narrowly dispersed graft copolymerization ABS composition according to claim 2, is characterized in that, described vinylbenzene monomer is one in styrene, methylstyrene and vinyltoluene kind. 5. The preparation method of a narrowly dispersed graft copolymerized ABS composition according to claim 2, wherein the vinyl cyanide monomer is acrylonitrile, methacrylonitrile or a mixture thereof. 6. the preparation method of a kind of narrow dispersion graft copolymerization ABS composition according to claim 2, is characterized in that, described ethylenically unsaturated carboxylate monomer is methyl acrylate, ethyl acrylate, butyl acrylate A kind of ester, methyl methacrylate. 7. the preparation method of a kind of narrow dispersion graft copolymerization ABS composition according to claim 2, is characterized in that, described lye is a kind of in sodium hydroxide, potassium hydroxide, and described emulsifying agent is alkane One or more of aryl sulfonate, rosin acid alkyl salt, fatty acid salt, the initiator is potassium persulfate, benzoyl peroxide, cumene hydrogen peroxide, di-tertiary peroxide One or more of butyl and azobisisobutyronitrile. 8. the preparation method of a kind of narrow dispersion graft copolymerization ABS composition according to claim 2, is characterized in that, described reduction system is the composition of fructose, ferrous sulfate and sodium pyrophosphate or EDTA One of the compositions of disodium salt, sodium formaldehyde sulfoxylate and ferrous sulfate, wherein the mass ratio of fructose, ferrous sulfate and sodium pyrophosphate is 10:4:1, sodium formaldehyde sulfoxylate, ferrous sulfate , the mass ratio of ethylenediaminetetraacetic acid disodium salt is 10:4:1, and the antioxidant is antioxidant AO-8020.

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