AU701522B2

AU701522B2 - Use of peroxyacids as molecular weight regulators

Info

Publication number: AU701522B2
Application number: AU36633/95A
Authority: AU
Inventors: Petrus Johannes Theodorus Alferink; John Meijer; Hans Westmijze
Original assignee: Akzo Nobel NV
Current assignee: Akzo Nobel NV
Priority date: 1995-11-03
Filing date: 1995-11-03
Publication date: 1999-01-28
Anticipated expiration: 2015-11-03
Also published as: AU3663395A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): AKZO NOBEL N.V.

A

Invention a a a a Title: USE OF PEROXYACIDS AS MOLECULAR WEIGHT

REGULATORS

The following statement is a full description of this invention, including the best method of performing it known to me/us: /4 ACD 2398 R 'Use of Peroxyacids as Molecular Weight Regulators The present invention relates to a method of radically.

(co)polymerizing vinyl ester, vinyl halide, diene, acrylonitrile and a-olefin monomers, optionally with one or more ethylenically unsaturated monomers, in the presence of a peroxyacid chain transfer agent to thereby control the molecular weight of the resulting (co)polymer, to. (co)polymers produced by this method and to the use of peroxyacids as molecular weight regulating agents in the polymerization of these monomers.

The general concept of employing a molecular weight regulating agent, 1 also known as a chain transfer agent, as an additive during polymerization reactions has been known for a long time. However, these chain transfer agents suffer from several disadvantages. For example, they often retard the polymerization reaction. Further, many .chain transfer agents contain mercaptan or other sulfur-containing 20 functional groups making their use and handling undesirable due to safety and environmental concerns. Finally, many chain transfer agents only function well in a particular reaction and cannot be used for other polymerization reactions or with a variety of different initiators.

S" In the (co)polymerization of vinyl chloride monomers, it is often desirable to obtain lower molecular weight products. This can be achieved either by polymerization at high temperature and pressure or by the use of a chain transfer agent. The first alternative is often undesirable since it places special demands on the reactor and the 3 type and amount.of polymerization initiator to be employed.

ACD 2398 R 2 The second alternative, use of a chain transfer agent selected from 2-mercaptoethanol, 2-ethylhexylthioglycolate and 2-ethylhexanal suffers from the disadvantages that the polymerization reaction is significantly retarded by these chain transfer agents, and some of these materials are undesirable for safety and environmental reasons.

It is the object of the present invention to overcome these disadvantages of known chain transfer agents by providing peroxyacid chain transfer agents which are not based on undesirable sulfur-containing groups and which do not or not substantially retard the polymerization reaction, but rather, may even accelerate the polymerization reaction. These and other objects of the present invention will be apparent from the summary and detailed description which follow.

In a first aspect, the present invention relates to a method of radically (co)polymerizing vinyl ester, vinyl halide, diene, 20 acrylonitrile and a-olefin monomers, optionally with one or more ethylenically unsaturated monomers, using a polymerization initiator in the presence of an amount of at least one peroxyacid chain transfer agent effective to reduce the molecular weight of the (co)polymer in comparison to a (co)polymer made by the same process without chain 25 transfer agent. The peroxyacid chain transfer agent used in the method of the present invention is selected from the group of compounds which contain the moiety of the formula I: 0 S II 30 -C-O-O-H More particularly, the preferred peroxyacids useful in the process of the present invention are selected from the group represented by the 1, following formulae: AGO 2398 R 3 0 R-C -0-0-H 00I wherein R is selected from the group consisting of H, CH 3 C(0)OOH,.

C(0)OH, C(0)QCH 3 C(0)0RI, C 2

-C

20 alkyl, C 3

-C

20 cycloalkyl,

C

6

-C

20 aryl, C 7

-C

20 aralkyl and C 7

-C

20 alkaryl, wherein the alkyl groups may be linear or branched and wherein the alkyl, cycloalkyl, aryl, aral kyl and al karyl groups are optionally substi tuted with one or more groups Y, wherein Y is a group selected from -C(0)OOH, hydroxy, alkoxy, aryloxy, epoxy, halogen, -C(0)0RI, -OC(0)RI, -C(0)OH, nitrile, nitro, -C(0)NRjR 2 -C(0)NHR 1 -C(0)NH 2 -N(Rj)C(o)R 2

-SO

2 NRjR 2

-SO

2 NHRj, -SO 2

NH

2 and -N(Rl)S0 2

R

2 wherein RI and R 2 are independently selected 'from the group consisting Of C 2 4C 20 alkyl,

C

3

-C

20 cyci oal kyl, C 6 4C 20 aryl, C 7 4C 20 aral kyl and C 7 4C 20 al karyl, wherein the alkyl groups may be linear or branched; and 20R 3

-X-R

4

(III)

wherein R 3 is selected from the group consisting of, hydrogen,

*C

1 4C 20 alkyl, C 3 4C 20 cycloalkyl, C 6

-C

20 aryl, C 7 4C 20 aralkyl,

C

7

-C

20 alkaryl and imido-group containing radicals, wherein the alkyl groups may be linear or branched; R 4 is selected from C 1

-C

20 alkylene,

C

2

-C

20 alkenylene, C 6 4C 20 arylene, C74C 20 aralkylene,

C

7

-C

20 alkarylene, C 3 4C 20 cycloalkylene and C 3 -4 20 cycloalkenylene, wherein the alkylene and alkenylene groups may be linear or branched; and R 3 and/or R 4 are optionally substituted with one or more groups Y 30 as defined above; and X is selected from nothing, -S0 2

-N(R

5 -C N[CC(0) and wherein R 5 is selected from the group consisting Of C 2

-C

20 alkyl, C 3

-C

20 cycloalkyl,

C

6

-C

20 aryl, C 7

-C

20 aral kyl and C 7

-C

20 al karyl, wherein the al kyl groups may be i near or branched and are optionally substituted with 4 1 ACD 2398

R

one or more groups Y as defined above; and R 3 and R 5 can combine to form a ring containing substituent selected from cycloalkyl, aryl, aralkyl or alkaryl, which ring is optionally substituted with one or more groups Y as defined above.

The present invention also relates to (co)polymers produced by this (co)polymerization method. In a third aspect, the present invention relates to the use of at least one peroxyacid of the formulae II and .III as a chain transfer agent in the radical polymerization of one or more ethylenically unsaturated monomers.

From U.S. Patent 2,813,885, it is apparent that peroxyacids are known compounds and have been used, for example, as polymerization initiators for free-radical polymerization reactions such as the polymerization of vinyl monomers. In addition, it is known from Soviet Inventor's Certificate 2,140,318 that fatty acid peroxides made from a C 3

-C

12 fatty acid fraction can be employed as a polymerization initiator and that these peroxides have a molecular weight regulating 20 effect. However, this teaching differs from the present invention since no separate polymerization initiator is employed and it is not certain that the fatty acid peroxides are, in fact, the peroxyacids used in the process as claimed in the present application.

I

25 Non-prepublished International patent application number PCT/EP93/03323 also discloses the use of particular unsaturated peroxyacids as chain transfer agents. However, these unsaturated compounds are outside the scope of the present application. Finally, peroxyacids are also known to be useful as polymerization initiators for acrylate polymerization at 130-140°C from, for example, U.S.

30 Patent 4,866,146. However, this patent application does not teach the use of peroxyacids as chain transfer agents.

ACD 2398 R Accordingly, the present invention provides a novel process for the (co)polymerization of vinyl ester, vinyl halide, diene, acrylonitrile and a-olefin monomers, optionally with one or more ethylenically unsaturated monomers, whereby lower molecular weight polymers can be attained without the attendant disadvantages of having to conduct the polymerization reaction at high temperatures and pressures or having to use a chain transfer agent which significantly retards the polymerization and/or contains undesirable sulfur groups. For the purpose of the present application, the term, "(co)polymer" should be understood to mean, "polymers and/or copolymers." The peroxyacids of the present invention may be prepared by one or more of the preparation methods for peroxyacids which are well known 1 to those of skill in the art. For example, in many cases the preparation can be accomplished by treating the corresponding carboxylic acid with hydrogen peroxide. Other synthesis routes can be found in, for example, Organic Peroxides, Daniel Swern, Editor, John Wiley Sons, Inc., New York (1970).

In a preferred embodiment of the present invention, the peroxyacids of the formulas II-III are limited to those where R is selected from

C

3

-C

2 0 alkyl, C 5

-C

20 cycloalkyl, C 7

-C

20 aralkyl and C 7

-C

20 alkaryl, all of which groups may be linear or branched, and where R 4 is 25 CI-C 20 alkylene, C 5

-C

20 cycloalkylene, C 6

-C

20 arylene,

C

7

-C

20 aralkylene, C 7

-C

20 alkarylene and C 3

-C

20 cycloalkenylene, X is nothing or sulfone and R 3 is an amido-group containing radical. Typical amido-group containing radicals which are preferred for the present invention are optionally substituted phthalimido 30 including tetrahydrophthalimido and hexahydrophthalimido, succinimido, maeimido, citraconimido and itaconmdo maleimido, citraconimido and itaconimido radicals.

ACD 2398 R 6 More preferably, the present peroxyacid chain transfer agents are substantially oil soluble such that they will dissolve in the monomer phase of suspension or emulsion polymerization media. Most preferably, the peroxyacids of the present invention are also storage stable at.

temperatures of up to 40 0

C.

The groups R, R 3 and R 4 may be selected on the basis of their influence on the chain transfer coefficient of the peroxyacid, for their effect on the oil-solubility of the peroxyacid, or to provide a more storage stable peroxyacid, depending upon the particular (co)polymerization method which will be employed. In this regard, R,

R

3 and R 4 groups containing longer chain (C 10

-C

20 alkyl groups are preferred due to the positive influence of such long alkyl groups on the oil-solubility and storage stability of the peroxyacids.

The peroxyacids of the present invention may be prepared, transported, stored and applied as such, or in the form of powders, granules, pastes, solutions, suspensions, emulsions, or in any other known 20 physical form. Which of these physical forms is preferred will depend upon the particular (co)polymerization reaction, as well as other conditions of transport, storage and use.

The process of the present invention may be operated in the same 25 manner and under essentially the same conditions as conventional processes employing known chain transfer agents such as 2-mercaptoethanol and 2-ethylhexanal. Further information regarding the conventional processes can be found, for example, in the paper, "High Temperature Polymerization and the Use of Chain Transfer Agents 30 in Low Molecular Weight PVC Manufacture," Hirose, Y. and Westmijze, PVC Seminar 1993 presented by Kayaku Akzo Corporation, as well as in Canadian patent application number 2,077,397. The present process is particularly suited for the (co)polymerization of vinyl chloride tA, j ACD 2398 R 7 monomers to obtain low molecular weight polymers useful in bottles and special injection-molded articles.

Also within the scope of the present invention are redox polymerization reactions such as are described in French Patent publicatioi 2,086,635; and German Patent publications 1,915,537 and 2,006,966. Typically, such a polymerization reaction is carried out in the presence of a reduction agent in an emulsion of the polymerizable monomer.

The peroxyacids used in the process of the present invention exhibit several advantages. First, these materials exhibit an unexpectedly good ability to control and lower the molecular weights of products of standard polymerization processes. Further, the severe retardation of the polymerization reaction which is often observed when a conventional chain transfer agent is employed does not occur when the present peroxyacids are employed. In fact, some of the preferred peroxyacids actually accelerate the polymerization reaction. Third, 20 the present chain transfer agents contain no undesirable sulfurcontaining groups such as mercaptans.

4 Additionally, the present chain transfer agents do not reduce monomer conversion. Finally, in some reactions the present peroxyacids 25 provide the further benefit that the amount of polymerization initiator required for the reaction can be reduced when used in combination with the peroxyacid. This further advantage results from :the fact that the peroxyacid, under certain conditions, can function both as a chain transfer agent and, to some extent, an initiator.

The present process is similar to conventional (co)polymerization processes except that the process is carried out in the presence of one or more peroxyacid chain transfer agents which is used in addition

IA

01 W ACD 2398 R 8 to the standard polymerization initiator. The amount of, and the type of peroxyacid may be chosen depending upon the reaction temperature, the monomers to be polymerized, the polymerization initiator employed and the degree of reduction of the molecular weight that is desired.

In general, the process of the present invention comprises the use of any amount of peroxyacid which reduces the molecular weight of the resultant (co)polymer in comparison to a (co)polymer made by an identical process in the absence of a chain transfer agent.

Typically, from 0.001 to 30 weight percent, based on the weight of the monomers, of peroxyacid chain transfer agent, is employed. More preferably, from 0.01 to 5.0% by weight of the peroxyacid is employed, and most preferably, from 0.02 to 2.0% of peroxyacid is used. Mixtures of two or more chain transfer agents may also be employed within the scope of the present invention.

It is preferred to choose a chain transfer agent which has a decomposition temperature which is above the polymerization 20 temperature since significant decomposition of the chain transfer S agent generally leads to a reduction in the chain transfer activity.

However, this need not always be the case. For example, it may be desirable to employ the peroxyacids of the present invention for the dual purpose of chain transfer agent and free radical initiator in 25 which case some decomposition of the peroxyacid during the 25 polymerization reaction will be desirable.

The polymerizable monomers useful in the process of the present invention are vinyl ester, vinyl halide, diene, acrylonitrile and 0 a-olefin monomers, which may optionally be copolymerized with one or 30 more ethylenically unsaturated monomers. The monomers should not be readily epoxidizeable under the polymerization conditions. Preferred monomers are vinyl chloride, vinylidene chloride, vinyl fluoride or ACD 2398 R 9 vinylidene fluoride. The comonomers may preferably be selected from acrylates, methacrylates, styrene, styrene derivatives, vinyl esters, vinyl halides, dienes, acrylonitrile and a-olefins. Preferably, the comonomers are not readily epoxidizeable under standard polymerization.

conditions.

As the polymerization initiator may be used conventional polymerization initiators which are well-known in the art. The preferred polymerization initiator for a particular reaction will depend on the monomers to be polymerized and the reaction temperature to be employed. The preferred initiators for use in the present invention are peroxyesters, peroxydicarbonates, diacyl peroxides and azo initiators.

The present invention also relates to (co)polymers and oligomers produced by the process of the present invention. Furthermore, the present invention also includes articles of manufacture which comprise one or more (co)polymers made in accordance with the process of the 20 present invention. The articles of manufacture may be, for example, bottles or injection molded articles. Finally, the present invention also relates to the use of peroxyacids as a chain transfer agent in radical polymerization processes.

o 25 The following examples are presented to further illustrate the present invention.

0 I *9999t 3 ACD 2398 R Examples 1-10 and Comparative Examples A-G Polyvinyl alcohol (0.39 g. Gohsenol® KP-08 ex. Nippon Gohsei) was dissolved in 520 g of water in a one liter Bichi stainless steel autoclave with a 3-bladed stirrer with baffle (735 and a temperature controller. To this solution was added a phosphate buffer system comprised of 0.2 g. Na 2

HPO

4 and 0.2 g. of NaH 2

PO

4 the amount and type of chain transfer agent given in Table 1 and 0.573 g of the polymerization initiator bis(3,5,5-trimethylhexanoyl) peroxide (assay 90.8%).

The reactor was then evacuated and flushed twice with nitrogen. After addition of 260 g. of vinyl chloride monomer, the reactor was heated 1 to the reaction temperature of 62 0 C over a period of 60 minutes and held at that temperature for 6 hours. Then, the remaining vinyl chloride monomer was vented and the polyvinyl chloride was filtered, washed with water and dried overnight at 50 0 C in an air-oven.

20 The polyvinyl chloride was then analyzed for conversion of vinyl chloride monomer on a weight basis. In addition, the mean particle size was determined using a Coulter Counter Multisizer, the bulk density and dry flow were determined by using an Erichsen Din Cup 243/11.8 according to ASTM 01895. The molecular weights are given as 25 K-values which were measured according to DIN norm 53726. The results are given in Table 1. In the Tables, C.P.T. stands for Constant Pressure Time.

Or Table 1 1 litre scale Chain Transfer Agent (C.T.A.)-experiments Chloride Monomer at 62*C. Initiator: bis(3,5.5-trimethylhexanoyl)peroxide (0.200%) on Vinyl C. T.A.

None 2-Ethyl hexanal.

mono-t-butyl peroxy mal eate 1-tert-Butyl peroxy-2-phenyl 2-propene Lauricacid 4-Hydroperoxy- 2-methoxy-pentane Perl auricacid Perl auri cacid Perl auri cacid 2-Ethyl perhexanoicacid Nonyl Aniido Peroxy Adipic Acid Dodecanedi (peracid) 2-n-Octanesul fonyl peraceticacid 3-n-Decanesul fonyl perpronionic acid n-Decyl butanediperacid Peraceticacid Peraceticacid Perhexanoic acid Performic acid Formic acid Example concentration number 01) conc A.0. conversion 00) C.P.T. Mean rate (min) of pressuredrop (bar/hr) 200 3.4 275 2.2 23(hr) 0 Bul k density (grlcm3) 0.250 0.200 0.200 0.930 0.150 1.000 0.500 0.250 0.500 0.500 0.200 0.300 0.200 0.300 0.100 0.400 0.300 0.300 0.250 1.702 1.553 1.791 7.407 3.704 1.852 5.000 2.788 2.735 1.905 1.633 1.655 2.105 8.400 3.600 7.520 92.4 87.1 55.6 86.8 93.8 86.4 93.9 92.8 92.7 92.8 91.5 92.5 91.2 91.7 86.7 91.2 90.3 90.7 88.1 90.6 0.46 0.44 0.45 0.58 0.49 0.46 0.39 0.42 0.45 0.44 0.40 0.43 0.42 0.40 0.35 0.43 0.43 0.40 0.39 0.44 M. P.S.

Pm) S. 154(225) 148(2211 136 (222) 196 (290) 156(232) 139(221) 148( 215) 154(222) 149(228) 146 (254) 151 (217) 149(219) 157 (351) 137(183) 157(242) 154 153 161 149 63 57.7 55.9 59.4 62.0 61.4 46.8 52.9 57.2 49.1 55.2 58.2 60.4 60.1 60.4 61.4 59.3 53.0 61.2 62.0 K-val ue 5.9 1.2 3.0 2.0 3.2 (Sep.)* 1.3 5.9 6.3 4.8 8.4 A.0. =Active Ogygen M.P.S. Mean Particle Size *phase separation at pressure drop ACD 2398 R 12 These examples demonstrate that chain transfer agents of the present invention lower the molecular weight of the resultant polymer in comparison to the control (Examples A, E and In addition, the polymerization time is significantly longer for prior art chain transfer agents than for the chain transfer agents of the present invention which, in most cases showed the same or a faster polymerization time than the control example. Also shown in Table 1 is that the chain transfer agents of the present invention have little influence on the mean particle size, such that a polymer of good quality and low molecular weight can be produced using the chain transfer agents of the present invention.

Example 11 and Comparative Examples H-K The same recipe and procedure was used for these examples as for Examples 1-10 except that several different, commercially available chain transfer agents were compared to a chain transfer agent in 20 accordance with the present invention. The results are given in Table 2.

*4 3 4 4 Ce CS C C Table 2 Kinetic influence of the application of different CTA's at 62'C using bis(3,5,5-trimethylhexanoyl)peroxide (0.2R. on VCM) as initiator.

Example concentrati on number 00) conversion conversion C.P.T.

(by weight) ()(min) None Pen auri caci d Thi og-lycol ate 2-Mercaptoethanol 2-Ethyl hexanal 0.250 0.120 0.050 0.250 92.0 92.7 88.2 87.1 90.6 91.3 91.6 88.7 86.7 88.6 80% conversi on time (hr:min) 4:45 4:30 5:25 5:40 5:10 Mean rate of pressure drop (bar/hr) 3.6 3.4 2.4 3.2 3.6 0.50 0.42 0.40 0.50 0.49 Bul k density (gr/cm3) M. P.S.

m) 161 (216) 163 (222) 142(194) 147 (202) 147(205) 62.2 56.0 57.1 55.3 57.7 K-Val ue M.P.S. Mean Particle Size ACD 2398 R 14 Table 2 clearly demonstrates the important advantage in reaction time that can be achieved using a preffered chain transfer agent of the present invention rather than the commercially available PVC chain transfer agents currently in use.

Examples 12-14 and Comparative Examples L-N The same procedure was employed for these examples as for the previous examples except that the polymerization initiator was varied in order to demonstrate that the chain transfer agent of the present invention works with several different polymerization initiators. The concentration of the initiator and CTA is expressed as weight percent 15 on VCM. The results are given in Table 3. I i 2 4 i:.0 23 i 0*Og 11 Now" "11 41p. lira ANIN ON,- C

S

a..

a. a. a.

4 Table 3 Influence of the use of different initiators applying Perlauricacid as CTA at a polymerization temperature of 62*C.

Initiator

C.T.A.

Example conc.

number 00) conc A.0. conversion (by weight)

NO)

conversion C.P.T.

00) (min) 80% conversi on time (hr:min) Mean rate of pressure-drop (bar/hr) Bul k density (gr/CM3) M. P.S.

(pm) K-val ue Bis(3,5,5 L trimethylhexanoyl peroxide None 0.200 1.018 Bis(3,5.5 trimethyl hexanoyl) peroxide Pen auri caci d t-butyl peroxyneodecanoate none 12 0.200 1.018 0.250 1.852 N 0.040 0. 262 92.0 92.9 83.0 88.8 91.3 91.6 84.3 88.6 88.4 91.0 192 4:45 180 4:30 193 5: 15 177 4:30 155 4:25 158 4: 10 0.50 161(216) 62.2 0.42 163(222) 56.0 1.5 0.47 168(229) 62.3 t-butyl peroxyneodecanoate Perl auri caci d 13 0.040 0.262 0.40 16Z(224) 56.7 Bi s(4-tert-butyl N cycl ohexyl) peroxydicarbonate none Bis(4-tert-butyl- 14 cyclohexyl peroxydi carbonate Perl auri caci d 0.250 1.852 0.055 0.221 0.055 0.221 0.250 1.852 1.8 0.50 178(249) 61.9 0.44 160(226) 56.7 A.0. Active Oxygen M.P.S. Mean Particle Size

V

ACD 2398 R 16 These experiments demonstrate that perlauric acid works well as a chain transfer agent with three different peroxidic initiators.

Examples 15-18 and Comparative Examples 0-R The same procedure was used for these examples as for the previous examples except that both polymerization temperature and initiator were varied, demonstrating that the chain transfer agents of the present invention can be employed over a wide temperature range. The results are given in Table 4.

a..i N i* a _i ACD 2398 R Table 4 Use of perlauric initiators acid as CTA at various temperatures using different Initiator

CTA

Example cone conc.A.0.

number (10-2%) Polymerization temperature K-value Bis(4-tert-butyl cyclohexyl)peroxy dicarbonate none Bis(4-tert-butyl cyclohexyl)peroxy dicarbonate Perlauric acid 2-Ethyl hexyl peroxy dicarbonate none 2-Ethyl hexyl peroxy dicarbonate Perlauric acid Bis(3,5,5-trimethyl hexanoyl)peroxide 20 none Bis(3,5,5-trimethyl hexanoyl)peroxide Perlauric acid Dilauroyl peroxide none Dilauroyl peroxide 0 0.07 0.28 15 0.07 0.28 0.25 1.85 0.06 0.28 16 0.06 0.28 53.5 53.5 57.0 57.0 62.0 62.0 68.0 68.0 0.25 1.85 69.0 61.3 a 6** a Q 0.20 1.02 17 0.20 1.02 64.5 58.7 62.2 56.0 57.2 53.4

I,

r 0.25 1.85 a ai a a a a. a.* a a R 0.10 0.40 18 0.10 0.40 perlauric acid 0.25 1.85 The foregoing examples were presented for the purpose of illustration and description only and are not to be construed as limiting the invention in any way. The scope of the invention is to be determined from the claims appended hereto.

Claims

1. A method of radically (co)polymerizing at least one monomer selected from vinyl ester, vinyl halide, diene, acrylonitrile and a-olefin monomers, optionally ;with one or more ethylenically unsaturated monomers, which comprises the step of polymerizing said monomer with a polymerization initiator in the presence of an amount of at least one peroxyacid chain transfer agent effective to reduce the molecular weight of th6 (co)polymer in comparison to a (co)polymer made by the same process without chain transfer agent, said peroxyacid chain transfer agent used in the method of the present invention being selected from the group of compounds which contain a moiety of the formula I: 4 0 -C-O-O-H

2. The method of claim 1 wherein said peroxyacid acid chain transfer agent is selected from 2 the group represented by the following formulae: 0 R-C-0-O-H (II) wherein .R is selected from the group consisting of H, CH 3 C(0)OOH, C(O)OH, C(0)OCH 3 C(0)OR, C 2 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 6 -C 20 aryl, C7-C20 aralkyl and C 7 -C 20 alkaryl, I wherein the alkyl groups may be linear or branched and wherein the alkyl, cycloalkyl, aryl, aralkyl and alkaryl are optionally substituted with one or more groups Y, wherein Y is a group selected from -C(O)OOH, hydroxy, alkoxy, aryloxy, epoxy, halogen, -C(0)OR 1 -OC(O)R 1 -C(O)OH, nitrile, nitro, -C(0)NR 1 R 2 -C(0)NHR 1 -C(0)NH 2 -N(R 1 )C(0)R 2 -S0 2 NR 1 R 2 -S0QNHRi, -S02NH 2 i 19 and -N(RI)S02R2; wherein R 1 and R 2 are independently selected from the group consisting of C 2 -C 20 alkyl, C 3 -C 20 cycloalkyl, C 6 -C 20 aryl, C7-C 20 aralkyl and C 7 -C 2 0 alkaryl, wherein the alkyl groups may be linear or branched; and 0 II R 3 -X-R 4 -C-0-0-H (III) wherein R 3 is selected from the group consisting of, hydrogen, Ci-C 20 alkyl, C 3 -C 2 0 cycloalkyl, C 6 -C 20 aryl, C 7 -C 20 aralkyl, C 7 -C 20 alkaryl and imido-group containing radicals, wherein the alkyl groups may be linear or branched; R 4 is selected from CI-C 20 alkylene, C 2 -C 20 alkenylene, C 6 -C 2 0 arylene, C 7 -C 20 aralkylene, C 7 -C 20 alkarylene, C 3 -C 20 cycloalkylene and C 3 -C 20 cycloalkenylene, wherein the alkylene and alkenylene groups may be linear or branched; and R 3 and/or R 4 are optionally substituted with one or more groups Y as defined above; and X is selected from a covalent bond, -SO2., and wherein R 5 is selected from the group consisting of C 2 -C 20 alkyl, C 3 -C 2 0 cycloalkyl, C 6 -C 2 0 aryl, C 7 -C 2 0 aralkyl and C 7 -C 2 0 alkaryl, wherein the alkyl I groups may be linear or branched and are optionally substituted with one or more groups Y as defined above; and R 3 and R 5 can combine to form a ring containing substituent selected from cycloalkyl, aryl, aralkyl or alkaryl, which ring is optionally substituted with one or more groups Y as defined above.

3. The method of claim 2 wherein in said chain transfer agent, R is selected from C 3 -C 2 0 alkyl, C 5 -C 2 0 cycloalkyl, C 7 -C 2 0 aralkyl and C 7 -C 20 alkaryl, wherein the alkyl groups may be linear or branched. i r i 20

4. The method of claim 2 wherein in said chain transfer agent, R 3 is selected from an amido-group containing radical, X is nothing or sulfone and R 4 is selected from the group consisting of C 1 -C 2 o alkylene, C 6 -C 20 arylene, C 7 -C 20 aralkylene and C 7 -C 20 alkarylene.

The method of claim 1 wherein said chain transfer agent is substantially oil-soluble.

6. The method of claim 1 wherein from 0.001 to 30 weight percent, based on the weight of the polymerizable monomer, of said peroxyacid chain transfer agent is employed.

7. The method of claim 6 wherein said monomer is vinyl chloride.

8. The method of claim 1 wherein said polymerization initiator is selected from the group consisting of azo initiators, peroxyesters, diacyl peroxides and peroxydicarbonates.

9. A (co)polymer produced by the method of claim 1. H\SiieonaVeep\36633 95.doc 22/10/98 t. #9 0** .4 4i *r 4 49 4. 4. 4 .1 I ,1l~ t 21 A method for the radical polymerization of one or more ethylenically unsaturated monomers, which comprises polymerizing said monomer in the presence of at least one peroxyacid chain transfer agent, wherein the peroxyacid contains a moiety of the formula I: 0 I -C-0-0-H C C Ce *~we C. we.. CC S CC C C C CCC, C C C C C C C C we Ce 9 CC CC Ce Dated this 22nd day of October 1998 AKZO NOBEL N.V. By their Patent Attorneys GRIFFITH RACK Fellows Institute of Patent Attorneys of Australia P. P .~4