MXPA99010003A - In situ process for making a bimodal hips having both high gloss and high impact strength - Google Patents

Abstract

A continuous bulk polymerization process for making a high gloss, high impact strength polystyrene based resin having a bimodal particle size distribution containing capsule particles having an average size of 0.2 to 0.6 microns and cellular particles having an average particle size of 1.2 to 8.0 microns. The process comprises three reaction zones in series where styrene and a styrene-butadiene copolymer are fed to the first reaction zone which is maintained at pre-phase inversion conditions and no particles are allowed to form. The capsule particles form in the second reaction zone which is maintained at post-phase inversion conditions. Polybutadiene is introduced into the third reaction zone which is also maintained at post-phase inversion conditions. The cellular morphology particles form in the third reaction zone. The resultant bimodal particle size polymer mixture may be subjected to devolitilization after the third reaction zone or, alternatively, the mixture can be subjected to further polymerization in one or more finishing reactors prior to polymerization.

Description

IN SITU PROCEDURE FOR THE PRODUCTION OF A POLYSTYRENE RESISTANT TO HIGH IMPACT, BIMODAL, WHICH HAS BOTH EXCELLENT POLISHMENT AND RESISTANCE TO HIGH IMPACT FIELD OF THE INVENTION The present invention relates to a process for the production of a high impact, high polishing or finishing polystyrene resin in a continuous in situ process, and to such compositions.

BACKGROUND OF THE INVENTION The polystyrene resin or opium polymer is typically a low brittle resin that has poor impact strength. It has been known for some time that the impact resistance of polystyrene can be greatly improved by the addition of elastic particles dispersed throughout the polystyrene resin. Polystyrene resins of improved strength achieved by the addition of elastic particles often refer to polystyrene resistant to REF .: 31434 high impact (for its acronym in English, HIPS). The size of the elastic particles and the concentration of the rubber particles dispersed within the HIPS resin are believed to affect the impact resistance of the HIPS resin. The addition of the elastic particles to PS to form HIPS tends to result in a reduction of the polish or finish of the resin and products made from the resin. The lack of polish or finishing of conventional HIPS resins is often a disadvantage relative to materials such as acrylonitrile-butadiene-styrene resin (ABS), which ABS generally had both high impact and high polish strength. finish. Many consumer products require a balance of both polish or finish and impact resistance. Examples of such products include telephones, computers, and other electronic devices for the consumer. Other requirements besides the resistance and the polish or finish for these products are the low cost and the availability in large volumes. In particular, the cost of the resin can be competitive with alternatives (such as ABS). Also, the resin must be available in large commercial volumes so a process for large-scale production can be viable. The polishing or finishing of conventional HIPS resins has been improved by using elastomeric or rubber particles of relatively small size, which oppose large-sized particles. Additionally, it has been found that resins having both small elastomeric particles and large elastomeric particles, in a bimodal size distribution, have both good polish or finish and high impact resistance. See, for example, US Patents 4,282,334 / 4,493,922 and 5,039,714. U.S. Patent 5,294,656 also discloses a bimodal resin composition. The resin of 656 comprises a styrene matrix containing small sized particles having a core / shell structure or layer with an average particle size of 0.1 to 0.4 microns, and large sized particles having a cellular structure with a Average particle size from 0.8 to 2.0 microns. U.S. Patent 5,334,658 to Blu enstein et al., Discloses a bimodal HIPS resin composition comprising 75 to 97% by weight of polystyrene and 3 to 25% of a particulate elastomeric (co) polymer. 40 to 98% by weight of the particulate elastomeric (co) polymer in the form of encapsulated particles having an average particle size from 0.1 to 0.6 microns; and 1 to 60% of the remaining (co) polymer having a particle size from 0.200 to 1200 microns and having a cell morphology; and from 40 to 99% by weight of the remaining (co) polymer having an average particle size from 1.2 to 8.0 microns which also has a cell morphology. The composition in Blumenstein et al. Was made by melting or dissolving in an extruder. U.S. Patent 5,428,106 to Schrader et al., Discloses a HIPS composition comprising 90 to about 55% by weight of polystyrene and 10 to about 45% by weight of rubber particles based on clogged and added diene. The rubber particles are composed of: up to about 80 weight percent having a capsule morphology and an average volume size from 0.1 to 0.4 microns; and from about 75 to about 20 weight percent rubber particles having a tangled morphology and having an average volume particle size from about 0.25 to about 1. examples of this patent describe production of claimed resin in a linear, continuous three-tube tubular reactor system. U.S. Patent 5,491,195 also by Schrader et al. it is a division of same main application as US Patent 5,428,106 described above. 195 describes a method of producing resin claimed in 106 patent. 195 describes use of three agitated tubular polymerization reactors connected in a series. 195 also describes a composition comprising 90 to 55 weight percent polystyrene and 10 to about 45 weight percent of diene based rubber particles dispersed within polystyrene matrix. rubber particles are composed of: up to about 80 weight percent rubber particles having a capsule morphology and a volume average particle size from 0.1 to 0.4 microns; 75 up to about 20 weight percent of entangled particles; and 1 to 25 weight percent rubber particles having a cell morphology and an average volume particle size from about 0.6 to about 1.2 microns. U.S. Patent 5,334,658 to Blumenstein et al. Does not describe an in situ procedure for producing bimodal HIPS. US Pat. No. 5,428,106 to Schrader discloses an in situ process for producing a high impact, polished or finished styrene resin but nei US Pat. No. 5,428,106 nor US Pat.

U.S. Patent 5,491,195 to Schrader et al., Discloses the use of such a process for the production of a bimodal resin. The compositions of the resins described in the Schrader et al. Patents comprise large amounts (75 to about 20 weight percent) of entangled type particles. The? 195 of Schrader et al. it also describes the presence of cell-type particles in the composition but the celr particles are of an average volume particle size from about 0.6 to 1.2 microns. US Patent 4,146,589 to Dupre discloses a method for producing a bimodal HIPS in a mass polymerization process. Dupre forms a first partially polymerized solution containing rubber particles having an average diameter of about 0.5 to 1.0 microns in a first reaction zone. A second partially polymerized solution containing rubber particles having an average diameter from about 2 to 3 microns is in parallel form in a second reaction zone. The first and second partially polymerized solutions are mixed together in a third reaction zone. The Dupre method requires two trains of reactors in parallel where the rubber particles are preformed to combine the two streams. The Dupre parallel reactor method requires at least one additional reaction step than the process of the present invention.

DESCRIPTION OF THE INVENTION In accordance with the present invention, there is provided a process for producing a high impact resistant polystyrene HIPS resin having both an exceptionally superior polish or finish and high impact strength. The present invention provides an "in situ process", which allows the production of high impact, polishing or top finishing HIPS resin, without separating the steps to produce two resins having different sizes of rubber particles and then bonding the two resins Also, the present invention can be easily performed on a large continuous scale Using the conditions of the present invention, it was found that a bimodal distribution of elastomer particles of a particular size range and type of elastomer is achieved. morphology, and that both the superior polish or finish and the high impact strength are also achieved for the resulting resin The process of the present invention produces a suitable resin to form a high impact, polish or high finish product, said resin It contains encapsulated particles of 0.2 to 0.6 microns and celr particles of 1.2 to 8.0 microns. The method of the present invention comprises: Contacting a first supply of styrene monomer and a styrene-butadiene copolymer feed in a first reaction zone under polymerization reaction conditions to form a first mixture; Control the reaction conditions in the first reaction zone so that there is no formation of encapsulated particles or reverse phase. Reacting the first mixture in a second reaction zone to form a substantial amount of the encapsulated particles and forming a second mixture; and contacting the second mixture in a third reaction zone with a polybutadiene under reaction conditions to form a substantial amount of the celr particles.

An advantage of the present invention is that Continuous Agitation Tank Reactors (CSTR), Stirring Tower Reactors, Horizontal Axial Segregation Reactors, and Pipe Reactors with Static Mixers can be used which are easily available in many of the polystyrene production devices of volumetric processes. In particular, the preferred reactors of the process of the present invention are the CSTR reactors.

Yet a further advantage of the method of the present invention is that a minimum number of stages is used and thus the number of reactors and the need for more equipment to produce a bimodal HIPS resin having a polish or finish and a resistance to the resistance are minimized. excellent impact. The process of the present invention can be carried out using very small new equipment to produce the HIPS resin resistant to high impact polish or top finish. It was found that to achieve the good polish or finish balance and impact resistance of the resin of the present invention, the amount of polybutadiene fed to the third reaction zone is preferably 3% to 30% by weight, more preferably 5% to 20% by weight of the styrene-butadiene copolymer feed to the first reaction zone. The advantages of the present invention described above, allow to produce a HIPS resin resistant to high impact, high polish or finish much cheaper than by the previous procedures. This lower cost of production allows the bimodal HIPS resin to be cost competitive with resins resistant to high impact, polish or excellent finish.

Among other factors, the present invention is based on our discovery that a HIPS resin resistant to high impact, excellent polish or finish that mainly contains encapsulated particles of 0.2 to 0.6 microns and cellular particles of 1.2 to 8.0 microns that can be produced in a continuous, on-site procedure. It was found that the resin of the present invention when used in conjunction with a plasticizer produces a resin that has particularly good impact properties. Particularly preferred plasticizers useful for this invention are mineral oil and polybutenes. It has been found that a particularly advantageous resin is achieved by the process of the present invention, when the volume of the encapsulated particles is preferably 50% to 90% of the total volume of the elastomeric particles and the volume amount of the cellular particles in the resin of the present invention it is preferably 5% to 30%, and more preferred 5% to 20% of the total volume of particles in the resin. According to a more preferred embodiment of the present invention the amount of encapsulated particles is preferably 75% to 90% of the total volume of elastomeric particles and the amount of cellular particles is preferably 5% to 15% of the total volume of particles of the elastomer in the resin. The amount of particles of the type entangled in the resin of the present invention is less than 20% of the total volume of the elastomer particles, preferably less than 15%, more preferably less than 10%, even more preferably less than 5%, and more preferably less than 2%. It has also been found that the total amount of elastomer in the resin of the present invention is preferably 5% to 20% by weight, more preferably 10 to 15% by weight, and more preferably 12 to 14% by weight.

DETAILED DESCRIPTION OF THE INVENTION The process of the present invention provides a continuous in situ styrene polymerization and elastomeric particle forming materials to form a bimodal HIPS composition having high impact strength and excellent polish or finish. Preferred elastomer-forming materials for use in the present invention, especially in the first reaction zone, include styrene-diene copolymers such as styrene-butadiene copolymers. The styrene and the diene can be polymerized to form a random copolymer. The styrene-diene copolymer may also be a so-called "styrene block copolymer." A styrene block copolymer (or styrene-diene block copolymer) is one in which polystyrene and polydiene occur in the form of blocks or segments that are substantially composed of homopolymers. The homopolymer segments are chemically linked together to form a single polymer chain having two or more homopolymer segments. Among the segments of homopolymers may be a region that is not homopolymeric but consists of both copolymers in a substantially random configuration. This region is called "tapered." Preferably in the process of the present invention a styrene-butadiene diblock copolymer is used as a feed to the first reaction zone Another form of elastomer which was found useful in the present invention especially as a feed to the third reaction zone is simply a diene-based rubber such as polybutadiene.Polystyrene can be added to the polydiene rubber to spread out somewhat, prior to use or can be used simply in its homopolymer form. A preferred form of rubber useful in the present invention is polybutadiene which is predominantly in the cis configuration. Other polydiene rubbers that can be used in the present invention include polyisoprene. A preferred method of the present invention is a continuous volumetric polymerization process which includes three reaction zones in series wherein the degree of polymerization is increased from the first reactor to the third reactor. Reactors suitable for this process include any of the designated reactors that are typically used in polystyrene bulk polymerization processes. Examples of suitable reactors include Continuous Stirring Tank Reactors (CSTR), Stirring Tower Reactors, Axially Segregated Horizontal Reactors, and Pipe Reactors with Static Mixers. Important characteristics of the reactors suitable for the process of the present invention include a temperature control element, a mixing element, and the ability to control the residence time in a given reactor. The preferred type of reactor for the process of the present invention is CSTR. The CSTR is advantageous because it makes it possible to specify the independent control of residence time in a given reactor by adjusting the level in a given reactor. Thus, the residence time of the polymer blends can be adjusted independently and optimized in each of the reactors in series. In the preferred process of the present invention, the styrene monomer and an elastomeric material, preferably the styrene-butadiene copolymer, are fed to a first reaction zone. The polymerization is initiated either thermally or chemically. Many chemical initiators are available for use in the present invention. Examples of initiators found useful in the present invention include tert-butyl peroxybenzoate and tert-butyl peracetate. The conditions were maintained to prevent phase inversion or formation of the discrete rubber particles in the first reaction zone. The degree of polymerization (the amount of monomer converted to polymer) in the first reaction zone is 3% to 25%, preferably 5% to 20%, more preferably 5% to 15%, more preferably 5% to 12%. An important function of the first reaction zone is to provide an opportunity to add the styrene monomer to the elastomer.

Optionally, a chain transfer agent can also be added to the first reaction zone (or, alternatively, to the preceding reaction zones) to facilitate the transfer of free radicals. Many chain transfer agents are well known in the art. Preferred chain transfer agents useful in the present invention are ethylbenzene, alpha methyl styrene and dodecyl mercaptan. The particularly preferred chain transfer agent useful in the present invention has been found to be 4- (1-methyl-1-ethylidene) -1-methyl-1-cyclohexane commonly known as terpinolene. The proper addition of the chain transfer agent can help control the size of the encapsulated particles formed in the next step. Preferably, the styrene-butadiene copolymer fed to the first reaction zone had a styrene weight content of 25% to 50%, more preferably 25% to 40%, and even more preferably 30% to 40%. The styrene-butadiene copolymer is preferably a styrene-butadiene block copolymer and more preferably a styrene-butadiene diblock copolymer. A styrene-butadiene diblock copolymer consists essentially of a polystyrene block chemically inserted into a polybutadiene block to form a polymer chain having predominantly two blocks. The effluent from the first reaction zone is allowed to flow into a second reaction zone. The second reaction zone is kept out of the phase inversion. In the second reaction zone, the encapsulated particles are formed having an average size of 0.2 to 0.6 microns. A substantial amount of the encapsulated particles is formed in the second reaction zone. At least 90%, preferably at least 95%, more preferably at least 98%, and more preferably at least 99% of the encapsulated particles formed in the process of the present invention are formed in the second reaction zone. The particle size of the encapsulated particles is controlled by adjusting the temperature, stirring speed, and residence time in the second reaction zone. The degree of polymerization in the second reaction zone is 20% to 55%, preferably 25% to 50%, and more preferably 30% to 40%. The effluent from the second reaction zone is allowed to flow into a third reaction zone. A second feed stream is also fed into the third reaction zone. The second feed stream provides a second source of elastomer. The second feed stream is preferably a diene-based rubber in styrene monomer. More preferably, the second feed stream contains a polybutadiene rubber. More preferably, the second stream contains a polybutadiene rubber predominantly in the cis configuration (also known as polybutadiene Hi Cis). A substantial amount of the cellular particles formed in the process of the present invention is formed in the third reaction zone. At least 85%, preferably at least 90%, more preferably at least 95%, and more preferably at least 98% of the cellular particles formed in the process of the present invention are formed in the third reaction zone. The conditions in the third reaction zone are controlled so that the rubber particles formed are predominantly of cell morphology and have an average particle size of 1.2 to 8.0 microns. The degree of polymerization in the third reaction zone is 40% to 85%, preferably 50% to 80%, more preferably 55% to 70%. It has been found that the rate of addition of the polybutadiene to the third reaction zone relative to the rate of addition of the styrene-butadiene copolymer to the first reaction zone had a significant impact on the impact balance and polish or finishing of the resin resulting. The rate of addition of the polybutadiene should be 1% to 30% by weight, preferably 3% to 30% by weight, and more preferably 5% to 20% by weight of the addition rate of the styrene-butadiene copolymer. A too high speed of the polybutadiene / SB copolymer could cause under polishing or finishing in the resulting resin or even a reduction of the impact resistance at very high speeds. If the speed is too slow, the impact strength of the resin is reduced due to a lack of cellular particles. The effluent from the third reaction zone can be devolatilized by conventional means to remove unreacted styrene monomer. In a preferred alternate embodiment of the present invention, the effluent from the third reaction zone is allowed to flow to one or more termination reactors prior to devolatilization. The termination reactor was operated to allow the polymerization to proceed to a more rapid termination. The degree of polymerization of the termination reactor in the alternative embodiment is 70% to 90%, preferably 75% to 85%. Still an additional alternative is to have at least two termination reactors. The degree of polymerization in the last of at least two terminating reactors is 75% to 90%, more preferably 82% to 90%. Another preferred embodiment of the present invention is the use of a plasticizer. The use of the plasticizer in the process of the present invention helps to improve the impact resistance of the resulting polymer. The plasticizer can be added at any point in the process as well as ensuring that it mixes well with the polymer. Preferred plasticizers for the present invention include mineral oil, polybutenes, or a combination of both mineral oil and polybutenes. The amount of plasticizer useful in the present invention on a total weight basis of the polymer produced is less than 10%, preferably 1% to 8%, more preferably 1% to 5%, and more preferably 2% to 4%. In this invention, the average particle size was determined using Transmission Electron Microscopy (TEM). It has been found that TEM is a more consistent and accurate procedure for determining the particle size in these resins in part because analytical techniques, such as laser beam scattering, employ the use of solvents. It has been found that the solvent can cause swelling of the rubber particles or even dissolve the styrene block copolymer causing inaccuracies in the measurements. The average particle sizes are determined using electronic micrographs of transmission of the ultra-thin pieces materials. The average size of the particle types is calculated separately. Therefore, the cellular particles and the single occlusion particles are all treated independently. These types of particles have distinctly different appearances which are recognized in the TEM image. The measurements of the particle size referred to in this application are average particle sizes as determined by the measurement method summarized below. The particle volumes as discussed in this application are determined using methods well known in the art such as the first given subsequently. The alternate measurement method also referred to below was not used for the measurements given in this invention but is effectively equivalent for the spherical particles. Measurement of particle size was achieved by (1) placing a transparency containing straight lines in a TEM photograph of the resin, (2) calculating the total length of line segments contained within the particles of a given type, and (3) counting the number of intersected particles. This procedure is repeated for many lines as much as necessary to give a reasonably good statistical average. The following formula is used to calculate the average particle size: total length of the segments divided Average particle size = number of intersected particles This method gives an average particle size even for particles that are not spherical. An alternative method to determine an average particle diameter is similar to the previous one but assumes that the particles are spherical. This involves measuring the particle size distribution of 500 particles of a given particle type from the electron micrograph (s) of transmission of an ultra-thin specimen. A histogram of the sizes is developed, then the following formula is used for the calculation of the average particle diameter: SniDi ^ Average particle diameter SniDi in. where ni is the number of soft particles that have a size Di. A reference of these measurement methods is Quanti tative Microscopy by R. T. Dehoff and F. N. Rhines, Techbooks, 1968. Additional parameters characterizing the material are the percentage by volume (or volume fraction) of elastomer in the form of cellular particles.

(Vce?) And the percentage by volume of elastomer in the form of Capsules (Vcap). These values are most conveniently calculated via image analysis of TEM images using the stereological principle of volume fraction = area fraction = line fraction = point fraction. Thus, the volume fractions of the Cellular (VCei, t) and Encapsulated (VCap, t) in the sample can be obtained individually. The details of the methods for obtaining these quantities (VCe?, T and VCap, t) from TEM images are described in standard stereology textbooks, for example, DeHoff and Rhines. Here, VCe?, T = V'Ce? / Vt, and VCap, t = V'Cap / Vt; where V'Cel is the actual volume of the Cellular particles in the sample, V'cap is the real volume of the Encapsulated in the sample, and Vt is the total volume of the sample.

The speed of the volume (R) of the Cellular to the Encapsulated is VCe?, T / Vcap, t / - which is the same as V'cei / V'cap. Thus, R - Vcel, t / Vcap, T = V 'cel / V' cap Since virtually all the elastomer is depleted in the production of Cellular particles and Encapsulated, the total volume of elastomer is V'cei + 'cap. The volume fraction of elastomer in the form of cellular particles is as follows: Vcel = V'cßl / (Vcßl + V'cap) = R / U + R) Correspondingly, the volume fraction of elastomer in the Encapsulated particle form is: VCap = V 'Cap / (V' cßl + V 'cap) = 1 / d + R) EXAMPLES Example 1 A solution containing 11.7% by weight of a styrene-butadiene copolymer 40/60 dissolved in a styrene monomer was continuously fed to a stirred tank reactor. The flow in and out of the reactor was equalized, and the level was maintained such that the average residence time was 1.5 hours. A chain transfer agent was added to the feed of the first CSTR. The temperature of the reactor was maintained at 120 ° C. The solution of the resulting fluent from the first CSTR, not yet in the reverse phase, was continuously fed to the second CSTR to be subjected to phase inversion at a temperature of 133 ° C and an average residence time of 1.5 hours. The effluent from the second CSTR was fed to a third CSTR, operated at 140 ° C, with an average residence time of 1.3 hours. To this third CSTR was added another feed stream comprised of polybutadiene rubber dissolved within the styrene monomer at 15% by weight. The rate of addition was such that the polybutadiene feed added in the third CSTR was 24% of the polybutadiene that was added in the first CSTR. The polymerization was continued in a quarter CSTR up to 85-90%. The mineral oil was added in the CSTR room in an amount to give 3.5% by weight in the final HIPS. The residual monomer was removed using conventional means. The properties of the resulting HIPS resin are shown in Table 1.

Example 2 Example 1 was repeated, but the rate of addition of the second feed stream, added to the third CSTR, was increased such that the addition of polybutadiene in the third reactor was 48% of the polybutadiene added in the first CSTR. The properties of the resulting HIPS resin are shown in Table 1.

TABLE 1 Properties Example 1 Example 2 Polybutadiene (% weight) 8.7 10.0 Mineral oil (% weight) 3.5 3.5 Melting flow g / 10 min 4.3 3.9 Izod foot-lb / in 2.0 2.4 Polishing or finishing% 101 99 Reflective tape% 56 76 Average particle size Particles Encapsulated micras 0.4 0.4 Microwave particles 1.5 1.5 It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property

Claims (20)

1. A process for producing a suitable resin to form a high impact, excellent polishing or finishing product, said resin contains encapsulated particles of 0.2 to 0.6 microns and cellular particles of 1.2 to 8.0 microns, said process is characterized in that it comprises: contacting a first supply of styrene monomer and a styrene-butadiene copolymer feed in a first reaction zone under polymerization reaction conditions to form a first mixture; b. controlling the reaction conditions in the first reaction zone so that there is no encapsulated particle formation or reverse phase. reacting the first mixture in a second reaction zone to form a substantial amount of the encapsulated particles and forming a second mixture; and d. contacting the second mixture in a third reaction zone with a polybutadiene under reaction conditions to form a substantial amount of the cellular particles.

2. The process according to claim 1, characterized in that the polybutadiene is fed to the third reaction zone at 1% up to 30% by weight of the speed at which the styrene-butadiene copolymer is fed to the first reaction zone.

3. The process according to claim 1, characterized in that said first, second and third reaction zones comprise tank reactors of continuous agitation.

4. The process according to claim 1, characterized in that the cellular particles comprise 5 to 30% by volume of the total volume of particle in the resin.

5. The process according to claim 1, characterized in that the encapsulated particles comprise 50 to 90% by volume of the total volume of particle in the resin.

6. The process according to claim 1, characterized in that the resin contains a total weight based on 80 to 90% polystyrene.

7. The process according to claim 1, characterized in that the effluent is fed from the third reaction zone to a fourth reaction zone under polymerization conditions.

8. The process according to claim 7, characterized in that the effluent is fed from the fourth reaction zone to a fifth reaction zone under polymerization conditions.

9. The process according to claim 7, characterized in that the effluent from the fourth reaction zone contains at least 25% by weight of unreacted styrene monomer.

10. The process according to claim 8, characterized in that the effluent from the fifth reaction zone contains less than 20% by weight of unreacted styrene monomer.

11. The process according to claim 6, characterized in that the resin contains a total weight basis of 1% to 5% polybutenes.

12. The process according to claim 6, characterized in that the resin contains a total weight based on 1% to 5% mineral oil.

13. The process according to claim 1, characterized in that the styrene-butadiene copolymer is a styrene-butadiene block copolymer.

14. The process according to claim 13, characterized in that the styrene-butadiene copolymer is a styrene-butadiene diblock copolymer.

15. The method according to claim 4, characterized in that the resin additionally comprises less than 20% by volume of entangled particles.

16. The method according to claim 4, characterized in that the resin additionally comprises less than 5% by volume of entangled particles.

17. A resin suitable for the formation of a high impact product, excellent polish or finish, said resin contains encapsulated particles of 0.2 to 0.6 microns and cellular particles of 1.2 to 8.0 microns, characterized in that said resin is produced by the steps that comprise: in contact with a first supply of styrene monomer and a styrene-butadiene copolymer feed in a first reaction zone under polymerization reaction conditions to form a first mixture; b. control the reaction conditions in the first reaction zone so that there is no 10 formation of encapsulated particles or reverse phase. reacting the first mixture in a second reaction zone to form a 15 substantial amount of the encapsulated particles and form a second mixture; Y d. contacting the second mixture in a third reaction zone with a Polybutadiene under reaction conditions to form a substantial amount of the cellular particles.

18. The resin according to claim 17, characterized in that the cellular particles produce up to 5 to 30% of the total volume of particles.

19. The resin according to claim 18, characterized in that the resin additionally comprises at least 15% by volume of entangled particles.

20. The process according to claim 1, characterized in that polybutadiene is fed to the third reaction zone in 5% to 20% by weight of the speed at which the styrene-butadiene copolymer was fed to the first reaction zone.