JPH06501721A - Polymerization method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Polymerization method The present invention relates to novel polymerization processes and products of such processes.

Both emulsion polymerization and suspension polymerization are methods widely used in the field of polymerization technology. Ru. Both of these combine one liquid or solid phase with another large amount of liquid phase, often one Generally, it involves dispersing in an aqueous phase. Generally, the fraction of the dispersed phase is Emulsifiers and/or colloidal stabilizers need to be present to prevent separation . In emulsion polymerization, reactants are dispersed in a bulk phase with the aid of surfactants and vigorous stirring. It is common to do so. The action of surfactants is to dissolve some of the substance to be polymerized. It is the formation of micelles in a solution. A large amount of radicals generated from the initiator is in the phase. Once formed, these must diffuse into the micelles to initiate polymerization. Must be. The properties of the surfactant depend on the polymerization rate, particle size, and particle size. Affects the distribution as well as the properties of the latex produced. Suspension polymerization method is surface active Although it has been carried out in the absence of substances, the solids content of the dispersion and/or the monomer polymer In all practical situations, suspension polymerization is It is carried out in the presence of activators or colloidal stabilizers. Similarly, the absence of surfactants Attempts to perform emulsion polymerization under It was not successful in terms of accuracy.

The presence of surfactants in the products of these methods may adversely affect the properties of the products. I sometimes lose it. In particular, adhesives containing latex produced by emulsion polymerization , ideally due to degradation at the bond interface due to surfactant migration within the latex. It does not reach a certain quality.

For example, high-intensity ultrasound generated by a horn has been used to induce polymerization; Such methods are disadvantageous in that the polymerization products are decomposed by ultrasound . During the bulk phase of the dispersed phase before and during the suspension polymerization process using high-intensity ultrasound There was also a proposal to help disperse the population. Hatate etc. are Chem, Eng, Co RNM, Vol. 35, p. 325-333, Sound in suspension polymerization of polystyrene. The effects of wave treatment have been reported. Japanese Patent Publication No. 247473/89 describes the reactant dispersed by sonication and then introduced into a typical polymerization reactor containing an initiator. A method for making thermosetting powder coatings using suspension polymerization is described. europe Patent Application No. 255,716A discloses that either before or during the polymerization reaction, high Static using suspension polymerization, sonicating the reactants using a density ultrasonic homogenizer The production of toners for developing electric images is described.

We have recently developed a polymerization reaction in a dispersion containing a polymerizable substance dispersed in a large amount of liquid phase. During this period, we discovered a new method for performing emulsion and suspension polymerization reactions using low-intensity ultrasound. I started it. A novel polymerization method accelerates the polymerization reaction rate and also It is now possible to produce stable latex without the presence of surfactants. You can obtain a focal point.

Accordingly, one aspect of the invention is to provide monomeric materials or prepolymers in a bulk liquid phase. A polymer latex comprising applying ultrasonic vibrations to a portion of the substance during a polymerization reaction. The present invention provides a method for producing

Preferably, the reaction medium consists of an emulsion or suspension of an organic substance in water.

Organic materials include polymerizable materials, initiators, and optionally protective colloids. organic matter preferably forms a homogeneous liquid phase at the reaction temperature. These substances are latex Polymerization in which the average particle size is less than 50 microns, preferably less than 20 microns. The body produces latex.

The method of the invention is conveniently carried out using high frequency or ultrasonic vibrators. . A wide range of sources can be used to obtain low-intensity ultrasound. For the construction of various useful devices For example, in ``Sonic Chemistry'', published by Ellis Howert in 1988. ``Applications and Uses of Ultrasound in Chemistry'' by Mason and Lorimer There is. An example of a preferred type of agitator is one that pumps the liquid medium through pacing vanes or vanes. This is a so-called whutstle reactor that vibrates and produces energy. Ru. Adjust the size of the chamber where the blade is installed, the pressure of the flow of the liquid medium, and the structure of the blade. The blades are vibrated at ultrasonic frequencies (20-50kHz) by This causes cavitation in the liquid. another kind of reaction The vessels are available from, for example, Lewis & Co., Oxford, Co. A reflective ultrasonic mixer as described in P407L225.

Generally, a chamber that applies ultrasonic vibrations to a dispersion is used to apply intense vibrations to the dispersion for a relatively short period of time. Relatively small dimensions are preferred to accommodate cavitation. dispersion liquid is preferably circulated through this chamber a number of times during the polymerization reaction.

Preferred ultrasound sources for use in the present invention pump the reaction medium under pressure and The blade-like vibrating means of the Itsul reactor vibrates at ultrasonic frequencies. The reaction medium is caused to collide with each other. The resulting ultrasonic vibrations create a cavity within the liquid. Invite a session. Such sources are limited as long as they are of sturdy and durable construction. It is for use. These also include ultrasonic generators, reaction vessels, pumps and optionally heat exchangers. suitable for preferred embodiments of the method of the invention forming part of a closed loop comprising .

In this embodiment, ultrasonic vibrations are generated continuously during the polymerization reaction. But long At any time, only a portion, preferably a small portion, of the dispersion is ultrasonically stirred to remove the remainder. This will cycle the loop. The speed at which the dispersion is circulated ensures that the dispersion is homogeneous. A speed is preferred such that the phase remains constant and does not stagnate or separate into separate phases. Yes. The circulation rate required to do so will depend on the nature and volume of the dispersion and the It varies depending on the characteristics of the sonic generator. Generally, the rate is the total dispersion per minute. , at least 2 cycles, usually at least 5 cycles, but more cycles Ring velocity may also be used. The permissible recirculation rate for each reaction system is easily determined empirically. You can Circulation rate at a constant pumping rate allows the reaction to proceed It changes as time goes on. If a constant circulation rate is to be maintained, the pump delivery rate adjustment is necessary. The need for such adjustments is also easily determined empirically. You can do something like that.

The method of the invention can be used to carry out any emulsion or suspension polymerization reaction.

A wide range of monomers can be polymerized using the method of the invention. release caused by heat Known to undergo radical polymerization or photochemically initiated free radical polymerization The monomers listed below are preferred for use in the present method. Examples of useful monomers include , alkyl esters of unsaturated carboxylic acids such as acrylic acid or methacrylic acid included. Particularly useful are those in which the alkyl group has at least 4 carbon atoms, preferably or at least 6 of these esters, but the number of carbon atoms in the alkyl group is Higher numbers of esters, for example up to 18, are also useful. An example of a useful ester is buti 1,2-ethylhexyl, octyldecyl acrylic acid or methacrylic acid or It is an isobornyl ester. Other commonly used monomers are vinyl acetate, Aliphatic acids such as vinylpropionate and vinylbutyrate, especially those with less than 6 carbon atoms. Vinyl esters of aliphatic acids 1. Acrylic acid, itaconic acid, maleic acid, huma vinyl esters of unsaturated carboxylic acids such as hydrochloric acid and methacrylic acid, styrene, Vinyl phenols such as alpha methylstyrene, chlorostyrene and styrene sulfonic acid vinyl compounds, vinyl alkyl esters such as vinyl ethyl ether, acrylic Nitriles such as nitrile and methacrylonitrile, acrylamide and methacrylonitrile unsaturated amides such as lylamide, vinyl chloride and vinyl bromide; Vinylidene, such as vinylidene, vinylidene chloride and vinylidene bromide, butadiene dienes and vinylpyridine, such as chlorine, chloroprene and isoprene. child Copolymers consisting of combinations of these monomers can also be produced using the method of the present invention. Ru.

In particular, at least one alkyl ester of acrylic acid or MEC1; Copolymers with vinyl esters of at least one aliphatic acid may be prepared. moreover, Such copolymers may contain small amounts of acrylic acid or methacrylic acid, for example up to 20% by weight. Containing lyric acid is useful. Methods for producing such materials are preferred according to the invention. form. Polyfunctional monomers are used to produce polymers with a certain degree of crosslinking. I can say it. A wide range of such polyfunctional monomers are known in the art. some An example of this is described, for example, in European Patent No. 273,605. Typical example Includes ethylene glycol diacrylate and hexanediol diacrylate. Contains diacrylates such as

The dispersion usually contains an initiator for the polymerization reaction. A wide range of initiators known in the art and the appropriate initiator for the particular polymerization is chosen according to common standards in the art. .

Initiators are water-soluble or oil-soluble compounds. Examples of water-soluble initiators include hydrogen peroxide, Ammonium peroxysulfate, sodium persulfate, potassium persulfate, sodium thiosulfate Thorium, sodium metabisulfite, sodium hensiphenone-4-methylsulfonate Thorium, 4-hendiyl N-N dimethyl-N-11-oxo-2-propenyl (oxyethyl)benzenemethanaminium bromide, (4-(-4-methylphenyl) Nylthio)phenyl]phenylmethanone-4-benzoyl-4-methyldipheny Rusulfite, 2-n-butoxyethyl-4-(dimethylamino)penzuate , 2-hydroxy-3-(4-benzoylphenoxy)-N,N,N-trimethane Tyl-1-propanaminium chloride monohydrate, (4-hendiylpencil) Trimethylammonium chloride. Examples of oil-soluble initiators include benzoin meth There's ether. If the initiator is a water-soluble compound, the polymerization is an emulsion polymerization.

In a preferred embodiment of the invention, the dispersion does not contain a micelle-forming surfactant, Using a water-soluble initiator means that the reaction is essentially an emulsion polymerization.

However, when using an oil-soluble initiator, the reaction is essentially or suspension polymerization in which the prepolymer is present in liquid particles. The amount of initiator used is , which is conveniently determined by standards known in the art, of 0.　 Amounts of 1-2.0% by weight are common.

If it is desired to maximize the solids content, to do so the reaction medium must be Preferably, it contains a colloidal stabilizer. The use of such stabilizers increases emulsion weight. is an established part of the art of polymerization and suspension polymerization, and these known stabilizers are It is useful to incorporate it into the method of invention. Both surface active and non-surface active stabilizers It is publicly known. Non-surface-active stabilizers are, in particular, laminates that are substantially free of surface-active substances. It is preferable to use it in the present invention when it is desired to produce Tex. The preferred additive is po (vinyl alcohol) PVA, but other known stabilizers, such as methyl Lulose or hydroxyethyl cellulose, polyacrylic acid, starch, gamua Gelatin cellulose derivatives such as ruginate and casein may also be used. stabilizer The efficiency of PVA as a compound varies with its molecular weight and in individual polymerization reactions. The stability of individual PVAs can be determined empirically. The amount of stabilizer used is generally in accordance with established practice in the field, e.g. 5% by weight of the weight of the solid material. It is as follows.

The reactants should be subject to controls appropriate to the initiator present for the polymerization to proceed. Must be. For thermal initiators, expose the reactants, including the initiator, to a suitably high temperature. or, in the case of photoinitiators, using a suitable light source such as a mercury vapor lamp. Polymerization can be initiated by irradiation. In either case, the reactants are must be placed in a suitable reaction vessel equipped with facilities to allow for the start-up. preferable In embodiments, this reactor forms part of a closed loop system.

Polymerization times and conditions are generally similar to those conventionally used for emulsion or suspension polymerization. resemble.

However, the method of the present invention and in particular the emulsion polymerization method does not require the use of a typical mechanically stirred reactor. Proceeds faster than when used. This acceleration of the production of polymer latex It is clear that this is particularly preferred.

The dispersed phase can be prepared using conventional methods such as mechanical stirring or homogenization with high intensity ultrasound. and disperse it in a large amount of liquid. However, in a preferred embodiment, the two phases are mixed together and dispersed by using low intensity ultrasound. Sunawa First, the reactants are placed in a reaction vessel that is incorporated into a closed-loop system that also includes an ultrasonic vibrator. It is convenient to introduce it. The reactants are circulated through this loop and the dispersed phase is mixed into the bulk phase. disperse. Polymerization can begin at the same time the pump is turned on, or is it usually possible to start polymerization? Disperse the reactants before starting the reaction.

The size of the dispersed material particles or liquid particles is determined by the size of the latex particles before polymerization starts. It is preferable to make it as small as the new size, that is, about 20 microns. . In the case of suspension polymerization, the size of particles in the dispersed phase is approximately the same before and after polymerization.

In the case of emulsion polymerization methods, the size decreases significantly during the reaction.

The mixture is agitated as it passes through the pump, which helps disperse the dispersed phase. be done. The degree of this agitation varies with pump design. In particular, the outlet from the pump The shape of the agitation affects the degree of agitation. by impinging on a liquid body or vibrating means In the case of ultrasonic generators that generate vibrations, the outlet from the pump is usually relatively close to the vibration means. Place it nearby. The shape of the outlet and its position relative to the vibration means will depend on the vibration strength generated. It has a considerable influence on the degree. These parameters are calibrated empirically and, in practice, Known generators such as Heutsl reactors generally include means and means for making such adjustments. and means for measuring the intensity of the ultrasonic vibrations produced. In the method of the present invention, the reactor is It is preferable to monitor to ensure that ultrasound is occurring, and More preferably, the strength is sufficient to produce a desirable latex.

The solids content of the reaction medium is preferably at least 20%, more preferably less. The content is at least 30% by weight. Fishing and the need to produce products that are stable for long-term storage Together, it is generally preferred to achieve as high a solids content as possible. The most usable High solids content depends on the nature of the monomer and/or prepolymer and also on the polymerization method. Characteristics vary, especially the nature of the initiator. The solids content depends on the viscosity of the reactant solution and the limited by the power of the pump used to circulate the reactants into a closed-loop system .

According to the method of the present invention, polymer dispersions with smaller particles than previously obtained are obtained. liquids are prepared and such novel polymer systems form a preferred embodiment of the present invention. It is something. Generally, the average size of the particles is 0.1-10 microns, more preferably is 0. 2-5. A 0 micron dispersion is preferred. Additionally, at least 60 , more preferably a dispersion in which 80% of the particles are less than 10 microns, Preferred for use in the present invention.

The polymer emulsions and suspensions of the present invention are used in a variety of applications. They are , for use in all applications in which polymer emulsions and suspensions are commonly used. Can be done. The presence of surfactants in conventional products is more or less a disadvantage. These emulsions, which generally do not contain significant amounts of surfactants, are Silanes or suspensions are preferred.

One useful application for the emulsions of this invention is in pressure sensitive adhesives. unsaturated carbo Polymers derived from alkyl esters of carbonic acid and their copolymerization with vinyl acetate Coalescing is known to be useful for this application, and these are useful in the present invention. It is. a polymer emulsion containing at least 15% by weight of solid materials, and In particular, those which do not substantially contain surface-active substances are preferred embodiments of the present invention. Configure the following.

The polymeric emulsilanes of this invention can be used in pressure sensitive adhesive tapes in a conventional manner.

That is, in general, an emulsion with an undried coating thickness of 1/L OO 0 inch is applied to a polymeric film support such as Melinex, Air dry the film to obtain a tape.

Other uses of the emulsion and suspension if5M of the present invention include the formulation of water-based paints and inks. products, aqueous adhesive formulations, and reagents, such as those used in immunoassays. It is a support.

The invention is illustrated by the following examples.

Example 1 Next reactant・ 200g water Polyvinyl alcohol (PVA) 4g Ammonium persulfate 1.5g Ethylhexyl acrylate (EHA) 90g Vinyl acetate (VA) 60g in a Dawe Minisonic Homogenizer Heutsl reactor. Mixed. The contents were heated to 80°C and maintained at this temperature for 1 hour while the reactants were It was pumped through the whistle at a rate of 1500 cc/min. What you get is , was a latex with the following properties: solids content 40% (approximately) Average particle size 1.71 Shelf life: 6 months (approximately) Good freeze-thaw stability* * In these examples, freeze-thaw stability is determined by freezing in a cold/fj warehouse and The latex was subjected to 30 cycles of heating and returning to ambient temperature. I investigated by doing this. If the polymer separates during or after the test, the sample is considered defective. evaluate. If it is stable, the rating is good and there is no precipitate of any kind. , the evaluation is very good.

In the following examples, the reactants described were mixed and tested in the same manner as in Example 1. I tried it.

Initiator, hensifhenone-4-methyl -Sodium sulfonate 3.0g Auxiliary initiator, N-methyljetanolamine: 7.5g These were subjected to a Huitzsle reaction. The mixture was mixed in a vessel and irradiated with a 400 watt medium pressure mercury lamp for 60 minutes at room temperature.

Characteristics of the obtained latex − Solid content: about 30% Average size of particles: Approximately 4.57μ Shelf life: Approximately 3 months Freeze-thaw stability: Very good Example 3 An oil-soluble initiator, benzoin methane, replaces water-soluble initiators and co-initiator systems. The same reactants as in Example 2 were used, except that 1.0 g of ether was used.

Characteristics of the obtained latex: Same as the latex of Example 2 except for poor freeze-thaw stability. same as tex Average size of particles 4.42μs Example 4 Same as Example 2 except that comonomer VA was omitted and 200 g of EHA was used. The same reactants were used.

Properties of the obtained latex Solids content: approx. 30% Average particle size, approximately 2.09 μm Shelf life: Approximately 6 months Freeze-thaw stability - good Example 5 The actual procedure was as follows: 1 g of oil-soluble initiator BME was used instead of initiator and co-initiator. The same reactants as in Example 4 were used.

Properties of the obtained latex Solid content: approx. 30% Average particle size: approximately 3.5 μm Shelf life: Approximately 6 months Good freeze-thaw stability Peel adhesion 175g 10.5 inch Peel adhesion was determined by applying the latex onto a polyester support with a doctor blade. , by drying in an oven at 80° C. for 48 hours. Dry adhesive filler The lum was 54±3 μm thick. Roll the tape using a 3.5kg roller. It was attached to a clean aluminum support. Peel strength is Instron 1026 tensile strength It was measured using a tester. In the examples below, peel adhesion was measured using the same method. Established.

Example 6 Instead of PVA, formula 4 (C9H19)CsHtO(CH2CH20)99C 6.0 g of nonionic surfactant Ikevar Co-990 with H2CH20H Other than that, the same reactants as in Example 4 were used.

The properties of the obtained latex were as follows Solid content: 39% Average particle size: 25 μm Shelf life〉18 months Good freeze-thaw stability Peel adhesion 230g 10.5 inches Inbornyl acrylate 250g PVA: 5g BME: t, 3g These were mixed in a Huetstle reactor and irradiated with UV light (400 watts) for 20 minutes. did. A stable polymer emulsion was obtained with a conversion of 89.4%.

Solid content: approx. 32% Average particle size: 3.0 microns Shelf life: 2 weeks Poor freeze-thaw stability Isobornyl acrylate 100g Vinyl acetate 150g PVA: 4g BME: 1.3g These were mixed in a Huetstle reactor and irradiated with UV light (400 watts) for 40 minutes. did. A stable polymeric emulsion silane was obtained with a conversion of 50%, and the polymer was 21°8 % by weight of vinyl acetate units.

Properties of the obtained latex.

Average particle size: 3.0 microns (evaluated from SEM photo) Shelf life: 2 weeks Water 450g n-butyl acrylate 250g These were mixed in a Huetstle reactor and irradiated with UV light (400 watts) for 30 minutes. did. A stable polymer emulsion was obtained with a conversion of 725%.

Properties of the obtained latex Solid content 26% Average particle size: 591 microns Shelf life: 3 months Poor freeze-thaw stability Example 10 Instead of sodium hensifer-4-methyl-sulfonate, 6.3 g (2 -acryloyloxyethyl)(4-henzoylhennru)dimethylammonium The procedure was the same as in Example 6 except that mu bromide was used.

Properties of the obtained latex Solid content 26% Average size of particles: approximately 3500 nm Shelf life: 3 months Poor freeze-thaw stability Peel adhesion 250g 10.5 inches Initiator Hendphenone-4-methyl-sulfonate sodium 3.0g Auxiliary initiator See Table 1 0.0587 mol These were mixed in a Huetsl reactor. , UV light (400 Watts) for 50-80 minutes (see Table 1). different aids The results using the initiator are shown in Table 1.

Table 1 Example 11 (results of 7) reaction polymer particles time content rate size 10 N-methyljetanol 7mino 60 31 364011N, N-methyl Chill Ethanonoke Mini/60 35 357012 Triethanolamine 60 32 580013 Triethylamine 60 33 347014N- n-butyljetanol 7mine 60 34 236015N-t-butylrune Ta/-Lua Mini/80 25 287016 2-(2-diethylamino -50202360 ethoxyl) ethanol Initiator-4,4-azobis(4-cyanovaleric acid): 3. Og whistle these Mix in a reactor, heat to 70'C and leave at this temperature for 35 minutes under nitrogen atmosphere. maintained at the same time.

Properties of the obtained latex Solid content: 36% Average particle size: 3250nm Shelf life, 3 months Good freeze-thaw stability The procedure was the same as Example 18 except that 4.5 g of PVA was used.

Properties of the obtained latex Solid content 30% Average particle size 4580nm Shelf life: 1 month Poor freeze-thaw stability Example 20 The same formulation and procedure as in Example 9 were used except that the monomer was replaced with n-butyl acrylate. there was. After 60 minutes of irradiation, a stable polymer suspension was obtained with a yield of 320%.

The resulting polymer suspension was examined using a scanning electron microscope, and the average particle size was 4 microns. It was rated as good. The shelf life of the suspension was 2 weeks.

Example 21 Using an ultrasonic homogenizer at a throughput of 10,100 O/min for 25 minutes, 6.0 g 450 g of distilled water containing 1. 5g (0,0 A monomer mixture containing hendiyne methyl ether (EHA28 5 g and 15 g of acrylic acid (AA)). Next, the mixture is Pump it into the reactor and irradiate it (U - 400 watts). During this time, the ultrasonic waves are continuously applied. Homogenization was performed using After 30 minutes of irradiation, a high yield of polymer @ suspension was obtained.

Polymer! ! i&turbidity was examined with a scanning electron microscope, and the average size of the particles was 7 microns. It was evaluated that The polymer suspension phase separated after approximately 4 weeks of storage.

Example 22 The same formulation and procedure as in Example 21 was used, except that AA was replaced with EGDMA. 30 After irradiation for minutes, a polymer suspension was obtained with a yield of 99.8%. precipitated with acetone When dried in an oven, it swelled in toluene but did not dissolve. A colored and brittle polymer was obtained. Examining polymer suspensions with a scanning electron microscope to find the average particle size The size was estimated to be 8 microns. The suspension phase separates after approximately 4 hours of storage. Ta.

A dispersion containing the following ingredients was made as follows: PVA solution H: 300 m1 Styrene (purified): 40ml cumene hydroperoxide 0.17g Fructose, 0.50g Ferric sulfate 0.17g Sodium birophosphate 1.5g Fructose and iron activator were dissolved together (60ml each). using cooling coil Styrene emulsion in a Dow Minisonic reactor maintaining the system at 30°C. I created a. fructose/iron activator solution and finally cumene hydroper Added oxide. The reaction stopped after 1 hour and 49% of styrene was polymerized. workman Marchon remained stable for several months. Repeat the above reaction and check the yield. Ta.

(a) First repetition - 46% (b) Second repetition - 48% Example 24 A dispersion containing the following ingredients was prepared as follows: PVA solution: 3 00m1 Styrene (purified): 40ml ammonium persulfate, 4g Distilled water 60ml Add ammonium persulfate (4g) to distilled water (60ml) until all is dissolved. Magnetically stirred. Occasionally, it was heated gently. The PVA solution and styrene are heated through the cooling system. It was emulsified. The initiator system was added and the emulsilane was circulated through the apparatus for 1 hour. . The emulsion remained stable for several months. 36% of styrene polymerized, 32%? obtained through repetition. If ammonium persulfate is replaced with potassium persulfate, 35% Polymerization occurred.

Example 24 was repeated to see what would happen after extending the experimental time. 1 sample ．． It was taken out after 2 and 3 hours, and the amount of polymerized styrene was measured.

1 hour later: 37% 2 hours later 54% 3 hours later 66% Submission of translation of written amendment (01″*184!08) Throat February 15, 1993

Claims (29)

[Claims] 1. During a polymerization reaction, a dispersion of liquid monomer or prepolymer material in a bulk liquid phase is A method of manufacturing a polymer latex comprising applying ultrasonic vibrations. 2. The dispersion is pumped under pressure and impinges on the vibrating means, thereby causing the means to vibrate. 2. Method according to claim 1, characterized in that the vibration is carried out at an ultrasonic frequency. 3. The dispersion is transferred to a closed vessel containing an ultrasonic generator, a pump, a reaction vessel and optionally a heat exchanger. 3. A method according to claim 1, characterized in that the loop is circulated. 4. The ultrasonic vibration source is housed in a chamber through which the reaction medium circulates. The method of any of the preceding claims. 5. The dispersion is passed through a vibrating means including a tuning blade so that the blade vibrates at an ultrasonic frequency. 5. A method according to claim 1, characterized in that the sea urchin is pumped. 6. Circulating the dispersion at a sufficient rate to ensure that the dispersion does not separate into its component phases 6. A method according to any one of claims 3 to 5, characterized in that: 7. All dispersions were passed through a chamber that applied ultrasonic vibrations at least twice per minute. 7. A method according to claim 6, characterized in that the method comprises cycling through the steps. 8. The dispersion is an emulsion of the monomeric or prepolymer material in a bulk liquid phase. A method according to any of the preceding claims, characterized in that: 9. The dispersion is a suspension of monomeric or prepolymer material in a bulk liquid phase. 8. A method according to any of claims 1-7, characterized in that: 10. Claim characterized in that the dispersion is substantially free of surface-active emulsifiers. 8 ways. 11. Any of claims 8 to 10, characterized in that the dispersion comprises a colloidal stabilizer. Reka method. 12. 12. Process according to claim 11, characterized in that the colloidal stabilizer is not surface active. 13. The claimant is characterized in that the colloidal stabilizer is poly(vinyl alcohol). The method according to claim 11 or 12. 14. Claim 8 characterized in that the dispersion is substantially free of surface-active substances. -13 methods. 15. Claims 8 and 10-14, characterized in that the dispersion comprises a water-soluble initiator. Either way. 16. Claims 9 and 11-14, characterized in that the dispersion comprises an oil-soluble initiator. Either way. 17. 17. Any of claims 15 or 16, characterized in that the initiator is a photoinitiator. that way 18. 17. Any of claims 15 or 16, characterized in that the initiator is a thermal initiator. That method. 19. The dispersion contains at least one alkyl ester of an unsaturated carboxylic acid. The method of any of the preceding claims, characterized in that: 20. Claim characterized in that the ester is an alkyl ester of acrylic acid Method of Section 9. 21. Claim characterized in that the dispersion contains at least 15% by weight of solid substances Method of Section 1-20. 22. The average size of dispersed particles in the polymer latex is less than 20 microns. 22. The method of claim 1-21, characterized in that: 23. characterized in that the average size of the dispersed particles is less than 10 microns, 23. The method of claim 22. 24. Polymerized materials in which the average size of latex particles is less than 10 microns (by weight). 25. 25. The latex of claim 24, which is substantially free of surface active substances. 26. A polymer latex produced by the method of any of claims 1-23. 27. The polymer is a monomer of an alkyl ester of an unsaturated carboxylic acid such as acrylic acid. 27. The polymer according to any one of claims 24-26, characterized in that it is a homopolymer or a copolymer. latex. 28. By applying the latex of any of claims 24-26 to a backing material. A pressure sensitive adhesive tape comprising a polymeric film produced by 29. Claims 1-23 substantially as described above with respect to said embodiments. Either way.