CN1085676C - Use of peroxyacids as molecular weight regulators - Google Patents

Abstract

The invention discloses a free radical (co)polymerization method of vinyl ester, vinyl halide, diene, acrylonitrile and α-olefin monomer, which can be arbitrarily combined with one or more ethylenically unsaturated monomers. Polymerization using a polymerization initiator in the presence of at least one peroxyacid chain transfer agent, effectively reduces the molecular weight of the (co)polymer as compared to a (co)polymer produced by the same method but without the use of a chain transfer agent . Also disclosed are (co)polymers produced by this process using specific peroxyacids as chain transfer agents in the free-radical polymerization of one or more ethylenically unsaturated monomers. These peroxyacids can significantly reduce molecular weight and can be used with various polymerization initiators.

Description

Application of Peroxyacid as Molecular Weight Regulator

The present invention relates to free radical (co)polymerization of vinyl esters, vinyl halides, dienes, acrylonitrile and alpha-olefin monomers, optionally with one or more ethylenically unsaturated monomers, wherein the Oxyacid chain transfer agents control the molecular weight of the resulting (co)polymers, and also relate to (co)polymers produced in this way, and the use of peroxyacids as molecular weight regulators in the polymerization of these monomers.

The general principle of using molecular weight regulators, ie chain transfer agents, as additives in polymerization reactions has long been known. However, these chain transfer agents have a number of disadvantages. For example, they often delay polymerization. Furthermore, many chain transfer agents contain mercapto or other sulfur-containing functional groups, making them difficult to use and handle due to safety and environmental concerns. Finally, many chain transfer agents only function well in one specific reaction and cannot be used in other polymerization reactions or with many different initiators.

In the (co)polymerization of vinyl chloride monomers, it is often desired to obtain low molecular weight products. This can be achieved by polymerization at high temperature and pressure or by using chain transfer agents. The first option is always not ideal due to the special requirements of the reactor and the polymerization initiator used and the dosage of the species.

The second option, selecting the following chain transfer agents: 2-mercaptoethanol, 2-ethylhexyl mercaptoacetate and 2-ethylhexyl aldehyde, also has the disadvantage that the polymerization reaction is significantly delayed by these chain transfer agents, of which Some substances are detrimental to safety and the environment.

It is an object of the present invention to overcome these disadvantages of the known chain transfer agents by providing peroxyacid chain transfer agents which are not based on undesirable sulfur-containing groups and which do not retard or substantially retard polymerization , On the contrary, it can even accelerate the polymerization reaction. These and other objects of the invention will be set forth in the following summary and detailed description.

First of all, the present invention relates to vinyl esters, vinyl halides, dienes, acrylonitrile and α-olefin monomers, which can be freely (co)polymerized with one or more ethylenically unsaturated monomers. In the presence of a certain amount of at least one peroxyacid chain transfer agent, using a polymerization initiator to carry out polymerization, compared with the (co)polymer produced by the same method without chain transfer agent, can effectively reduce the molecular weight of the (co)polymer . The peroxyacid chain transfer agent used in the method of the present invention is selected from the compound containing part of formula I:

其中R选自基团H、CH₃、C(O)OOH、C(O)OH、C(O)OCH₃、C(O)OR₁、C₂-C₂₀烷基、C₃-C₂₀环烷基、C₆-C₂₀芳基、C₇-C₂₀芳烷基和C₇-C₂₀烷芳基，其中的烷基可以是直链或支链的，其中烷基、环烷基、芳基、芳烷基和烷芳基可以任意地被一个或多个Y基团取代，其中Y选自基团-C(O)OOH、羟基、烷氧基、芳氧基、环氧基、卤素、-C(O)OR₁、-OC(O)R₁、-C(O)OH、腈基、硝基、-C(O)NR₁R₂、-C(O)NHR₁、-C(O)NH₂、-N(R₁)C(O)R₂、-SO₂NR₁R₂、-SO₂NHR₁、-SO₂NH₂和-N(R₁)SO₂R₂；其中R₁和R₂独立地选自基团C₂-C₂₀烷基，C₃-C₂₀环烷基，C₆-C₂₀芳基，C₇-C₂₀芳烷基和C₇-C₂₀烷芳基，其中的烷基可以是直链或支链的；和其中R₈选自氢、C₁-C₂₀烷基、C₃-C₂₀环烷基、C₆-C₂₀芳基、C₇-C₂₀芳烷基、C₇-C₂₀烷芳基和含亚氨基的基团，其中烷基可以是直链或支链的；R₄选自基团C₁-C₂₀亚烷基、C₂-C₂₀亚链烯基、C₆-C₂₀亚芳基、C₇-C₂₀亚芳烷基、C₇-C₂₀亚烷芳基、C₃-C₂₀亚环烷基和C₃-C₂₀亚环烯基，其中亚烷基和亚链烯基可是是直链或支链的；R₃和/或R₄可任意地被一个或多个上述Y基团取代；X可以不存在或选自基团-SO₂-、-N(R₅)C(O)-、-C(O)N(R₅)-、-C(O)N〔C(O)(R₅)〕-和-NHC(O)N(H)-；其中R₅选自基团C₂-C₂₀烷基，C_3-20环烷基，C_6-20芳基，C₇-₂₀芳烷基和C₇-C₂₀烷芳基，其中烷基可以是直链或支链的，并可任意地被一个或多个上述Y基团；R₃和R₅可以连结成一个包含选自环烷基、芳基、芳烷基或烷芳基的取代基的环，该环可任意被一个或多个上述Y基团取代。More specifically, the peroxyacid used in the method of the present invention is more preferably represented by the following molecular formulas (II) and (III):

wherein R is selected from the group H, CH ₃ , C(O)OOH, C(O)OH, C(O)OCH ₃ , C(O)OR ₁ , 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, where the alkyl can be straight or branched, where the alkyl, cycloalkyl , aryl, aralkyl and alkaryl groups may be optionally substituted by one or more Y groups, wherein Y is selected from the group -C(O)OOH, hydroxyl, alkoxy, aryloxy, epoxy , halogen, -C(O)OR ₁ , -OC(O)R ₁ , -C(O)OH, nitrile, nitro, -C(O)NR ₁ R ₂ , -C(O)NHR ₁ , -C(O)NH ₂ , -N(R ₁ )C(O)R ₂ , -SO ₂ NR ₁ R ₂ , -SO ₂ NHR ₁ , -SO ₂ NH ₂ and -N(R ₁ )SO ₂ R ₂ ; wherein R ₁ and R ₂ are independently selected from groups 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 can be straight or branched; and _Wherein R is selected from hydrogen, C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl, C ₇ -C ₂₀ aralkyl, C ₇ -C ₂₀ alkaryl and An imino-containing group, wherein the alkyl group can be linear or branched; _R4 is selected from the group C ₁ -C ₂₀ alkylene, C ₂ -C ₂₀ alkenylene, C ₆ -C ₂₀ alkylene Aryl, C ₇ -C ₂₀ aralkylene, C ₇ -C ₂₀ alkarylene, C ₃ -C ₂₀ cycloalkylene and C ₃ -C ₂₀ cycloalkenylene, wherein alkylene and chain Alkenyl may be linear or branched; _R3 and/or _R4 may be optionally substituted by one or more of the above Y groups; X may be absent or selected from the groups _-SO2- , -N(R ₅ ) C(O)-, -C(O)N(R ₅ )-, -C(O)N[C(O)(R ₅ )]- and -NHC(O)N(H)-; where R ₅ is selected from the group C ₂ -C ₂₀ alkyl, C _3-20 cycloalkyl, C _6-20 aryl, C ₇ - ₂₀ aralkyl and C ₇ -C ₂₀ alkaryl, wherein the alkyl can It is straight-chain or branched, and can be optionally replaced by one or more of the above-mentioned Y groups; _R3 and _R5 can be linked to form a substituent containing a group selected from cycloalkyl, aryl, aralkyl or alkaryl The ring of the group can be optionally substituted by one or more of the above-mentioned Y groups.

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

In US Patent 2813885 peroxyacids are disclosed as known compounds and their use, for example as polymerization initiators in free radical polymerization reactions such as the polymerization of vinyl monomers. It is also disclosed in Soviet Inventor's Certificate 2,140,318 that fatty acid peroxides composed of C ₃ -C ₁₂ fatty acid moieties can be used as polymerization initiators, and that these peroxides have a molecular weight regulating effect. However, the absence of a separate polymerization initiator and the lack of clarity that the fatty acid peroxygen is actually the peroxyacid used in the claimed process of the present application just indicates a departure from the present invention.

Unpublished International Patent Application PCT/EP 93/03323 also discloses the use of specific unsaturated peroxyacids as chain transfer agents. However, these unsaturated compounds are outside the scope of this application. Finally, peroxyacids are also known, for example from US Pat. No. 4,866,146, as polymerization initiators for the polymerization of acrylates at 130-140° C. However, these patent applications do not describe the use of peroxyacids as chain transfer agents.

Accordingly, the present invention provides a novel process for the (co)polymerization of vinyl esters, vinyl halides, dienes, acrylonitrile and alpha-olefin monomers, optionally with one or more ethylenically unsaturated monomers , lower molecular weight polymers can be obtained without carrying out the polymerization at elevated temperature and pressure, or the disadvantages of using chain transfer agents that significantly retard polymerization and/or contain undesirable sulfur groups. For the purposes of this application, "(co)polymers" are to be understood as "polymers and/or copolymers".

The peroxyacids of the present invention can be prepared by one or more methods for preparing peroxyacids known to those skilled in the art. For example, in most cases it can be prepared by treating the relevant carboxylic acid with hydrogen peroxide. Additional synthetic routes can be found, for example, in Organic Peroxides, Daniel Swern, Editor, John Wiley & Sons, Inc., New York (1970). In a preferred embodiment of the present invention, the formula II-III peroxyacid is defined as R selected from the group C ₃ -C ₂₀ alkyl, C _5-20 cycloalkyl, C ₇ - ₂₀ alkaryl and C _7-20 aryl Alkyl, all of these groups can be linear or branched, R ₄ is C ₁ -C ₂₀ alkylene, C ₅ -C ₂₀ cycloalkylene, C ₆ -C ₂₀ arylene, C ₇ - C ₂₀ aralkylene group, C ₇ -C ₂₀ alkarylene group and C ₃ -C ₂₀ cycloalkenylene group, X can have no or sulfone group, and R ₃ is a group containing amido. Preferred representative amido-containing groups of the invention are optionally substituted phthalimides, including tetrahydrophthalimides and hexahydrophthalimides, succinimidyl, maleimido , citraconimide and itaconimide.

More preferred peroxyacid chain transfer agents of the present invention are substantially oil-soluble such that they will dissolve in the monomer phase of the suspension or emulsion polymerization medium. The most preferred peroxyacids of the present invention are also storage stable up to 40°C.

The groups R, _R3 and _R4 are chosen based on their effect on the chain transfer constant of the peroxyacid, because of their effect on the oil solubility of the peroxyacid, or depending on the particular (co)polymerization method used, to provide storage A more stable peroxyacid. In this regard, preference is given to R, _R3 and _R4 groups containing longer chain (C ₁₀ -C ₂₀ ) alkyl groups, since such long alkyl groups have a positive influence on the oil solubility and storage stability of peroxyacids .

The peroxyacid of the present invention can be prepared, transported, stored and applied as it is, or in powder, granule, paste, solution, suspension, emulsion or any other known physical form. The choice of a particular physical form will depend on the particular (co)polymerization and other shipping, storage and use conditions.

The operating method and conditions adopted by the method of the present invention are the same as those commonly used with known chain transfer agents such as 2-mercaptoethanol and 2-ethylhexanal. More detailed information on commonly used methods can be found, for example, in "High Temperature Polymerization and the Use of Chain Transfer Agents in Low Molecular Weight PVC Manufacture," Hirose, Y. and Westnijze, H., PVC Seminar 1993 Presented by Kayaku Akzo Corporation and Canadian Patent Application 2077397 . The process of the invention is especially suitable for the (co)polymerization of vinyl chloride monomers to obtain low molecular weight polymers for bottles and special injection molded products.

Redox polymerization reactions such as those disclosed in French patent publication 2086635 and German patent publication 1915537, 2006966 are also within the scope of the present invention. Usually the polymerization is carried out in an emulsion of polymerizable monomers in the presence of a reducing agent.

The peroxyacids used in the method of the invention have a number of advantages. First, these materials have an outstanding ability to control and reduce the molecular weight of the product during ordinary polymerization reactions. Second, the severe retardation of polymerization that occurs with conventional chain transfer agents does not occur when using the peroxyacids of the present invention. In fact, some preferred peroxyacids accelerate polymerization. Third, the chain transfer agents of the present invention do not contain undesired sulfur-containing functional groups such as mercapto groups.

Furthermore, the chain transfer agents of the present invention do not reduce monomer conversion. Finally, the peroxyacids of the present invention also exhibit better performance in some reactions, ie, when used in combination with peroxyacids, the amount of polymerization initiator required for the reaction can be reduced. This advantage is actually due to the fact that under certain conditions peroxyacids have both the function of a chain transfer agent and, to some extent, the function of an initiator.

The method of the present invention is similar to the common (co)polymerization method, but the difference is that when the method is carried out, in the presence of one or more peroxyacid chain transfer agents, a general polymerization initiator is also used. The amount and type of peroxyacid are selected according to the reaction temperature, the monomers to be polymerized, the polymerization initiator used and the desired degree of molecular weight reduction. In general, the process of the invention involves the use of any amount of peroxyacid which reduces the molecular weight of the resulting (co)polymer compared to a (co)polymer produced by the same process without the use of a chain transfer agent.

Typically, peroxyacid chain transfer agents are used in amounts of 0.001 to 30% wt. based on the weight of the monomers. A more preferred amount of peroxyacid is from 0.01 to 5.0% wt. The most preferred amount of peroxyacid is from 0.02 to 2.0% wt. It is also within the scope of this invention to use mixtures of two or more chain transfer agents.

Since significant decomposition usually results in a decrease in chain transfer activity, the preferred chain transfer agent has a decomposition temperature higher than the polymerization temperature. However, circumstances do not require this to always be the case. For example, the peroxyacids of the present invention can be used for the dual purpose of being both chain transfer agents and free radical initiators, so that some peroxyacids which decompose during polymerization are desired.

The polymerizable monomers used in the process of the present invention are vinyl esters, vinyl halides, dienes, acrylonitrile and alpha-olefin monomers, optionally copolymerized with one or more ethylenically unsaturated monomers. The monomer should not be susceptible to epoxidation under polymerization conditions. Preferred monomers are vinyl chloride, 1,1-dichloroethylene, vinyl fluoride or 1,1-difluoroethylene. The comonomers are preferably selected from acrylates, methacrylates, styrene, styrene derivatives, vinyl esters, vinyl halides, dienes, acrylonitrile and alpha-olefins. Preference is given to using comonomers which are not readily epoxidizable under normal polymerization conditions.

The polymerization initiator used may be a general polymerization initiator known in the technical field. The preferred polymerization initiator for a particular reaction depends on the monomers being polymerized and the reaction temperature employed. The initiators used in the present invention are preferably peroxyesters, peroxydicarbonates, diacyl peroxides and azo initiators.

The invention also relates to the (co)polymers and oligomers produced by the process according to the invention. In addition, the present invention also includes articles made from one or more (co)polymers produced by the process of the present invention. For example, the article of manufacture may be a bottle or an injection molded article. Finally, the invention also relates to the use of peroxyacids as chain transfer agents for free-radical polymerization processes.

The following examples further illustrate the invention.

Examples 1-10 and Comparative Examples A-G

In a stainless steel Büchi autoclave of 1 liter capacity equipped with a baffled three-blade stirrer (735 rpm) and a temperature controller, polyvinyl alcohol (0.39 g, Gohsenol® ^KP -08ex. Nippon Gohsei) Dissolve in 520g of water. In this solution, add the phosphate buffer system containing 0.2g Na ₂ HPO ₄ and 0.2g NaH ₂ PO ₄ , chain transfer agent (see Table 1 for consumption and type) and 0.573g polymerization initiator bis(3,5,5- Trimethylhexanoyl) peroxide (analytical purity 90.8%).

The autoclave was then evacuated and flushed with nitrogen twice. After adding 260 g of vinyl chloride monomer, the reactor was heated for 60 minutes to a reaction temperature of 62° C. and maintained at this temperature for 6 hours. Then, the remaining vinyl chloride monomer was drained and the polyvinyl chloride was filtered, washed with water, and dried overnight in an air oven at 50°C.

The polyvinyl chloride was then analyzed to determine the conversion of vinyl chloride monomer (on a weight basis). In addition, the average particle size was determined with a Coulter Counter Multisizer, and the bulk density and dry flow were determined by the ASTM D1895 method with an Erichsen Din Cup 243/11.8. Molecular weights are expressed as k-values determined according to DIN rule 53726. The results are listed in Table 1. C.P.T in the table means constant pressure time.

            Table 11 liters of chain transfer agent (C.T.A), tested at 62°C. Initiator: Bis(3,5,5-trimethylhexanoyl) peroxide (0.200%, based on vinyl chloride monomer) C.T.A. Example No. Concentration A.O. Concentration Conversion C.P.T. Average Pressure Bulk Density M.P.S. k-value

Decline rate (μm)

(%) (10-2%) (%) (min) (bar/hour) (gr/cm ³ ) (..)＝d 95 no A -- -- 92.4 200 3.4 0.46 154(225) 632-B Hexyl aldehyde B 0.250 -- 87.1 275 2.2 0.44 148(221) 57.7 Mono-tert-butyl peroxymaleic ester C 0.200 1.702 55.6 23(hr) 0 0.45 136(222) 55.91-tert-butyl-peroxy -2-Phenyl-2-propene D 0.200 1.553 86.8 365 1.0 0.58 -- 59.4 Lauric acid E 0.930 -- 93.8 201 3.8 0.49 196(290) 62.04-Hydroperoxy-2-methoxy-pentaneF 0.150 1.791 86.4 325 2.8 0.46 156(232) 61.4过月桂酸1a 1.000 7.407 93.9 163 3.0 0.39 139(221) 46.8过月桂酸1b 0.500 3.704 92.8 174 3.1 0.42 148(215) 52.9过月桂酸1c 0.250 1.852 92.7 184 2.9 0.45 154 (222) 57.2 2-Ethylperhexanoic acid2 0.500 5.000 92.8 140 5.9 0.44 149(228) 49.1 Nonanoylamino peroxyadipate3 0.500 2.788 91.5 180 1.2 0.40 146(254) 55.2 Dodecane di(peracid) 4 0.200 2.735 92.5 180 3.0 0.43 151(217) 58.22-n-hemialkylsulfonylperacetic acid5 0.300 1.905 91.2 207 2.0 0.42 149(219) 60.43-n-decanesulfonylperpropionic acid6 0.200 1.633 27 9 351) 60.1 orthopedic cylindrotamide 7 0.300 1.655 86.7 154 (separation) 0.35 137 (183) 60.4 Passive acid 8A 0.100 2.105 91.2 208 1.3 0.43 157 (242) 61.4 Passive acid 8B 0.400 8.3 222 5.9 0.43 154 59.3.3 Percaproic acid 9 0.300 3.600 90.7 205 6.3 0.40 153 53.0 Performic acid 10 0.300 7.520 88.1 218 4.8 0.39 161 61.2 Formic acid G 0.250 -- 90.6 210 8.4 0.44 149 = 62.0 AO

M.P.S. = mean particle size

*Phase separation upon pressure drop

These examples demonstrate that the chain transfer agents of the present invention are capable of reducing the molecular weight of the polymerized product as compared to Comparative Examples A, E and G. And the polymerization time using the chain transfer agent of the prior art is significantly longer than that of the chain transfer agent of the present invention, and in many cases the polymerization time of the chain transfer agent of the present invention is the same as or shorter than that of the reference examples. Table 1 also shows that the chain transfer agent of the present invention has little effect on the average particle size, so that good quality low molecular weight polymers can be produced using the chain transfer agent of the present invention. Example 11 and Comparative Examples H-K

The formulations and procedures used in these examples were the same as in Examples 1-10, except that a number of different, commercially available chain transfer agents were used for comparison with the chain transfer agents of the present invention. The results are listed in Table 2. Table 2 uses two (3,5,5-trimethylhexanoyl) peroxides (0.20%, taking VCM as a benchmark) as initiators, at 62°C, the kinetics of applying different CTAs affects the concentration of CTA Example No. Conversion rate Conversion rate C.P.T. 80% Average pressure Bulk density M.P.S. K-value

(%) (weight) (%) (min) Transformation time Decline rate (gr/cm ³ ) (μm)

( %) (Hour:) (Bazi/hour) (..) = D 95 No H-92.0 91.3 192 4:45 3.6 0.50 161 (216) 62.2 over lauginic acid 11 0.250 92.7 91.6 180 4:30 3.4 0.42 163 (222) 56.0 cymbal acetate I 0.120 88.2 88.7 228 5:25 2.4 0.40 142 (194) 57.12-cylindrical ethanol J 0.050 87.1 86.7 234 5:40 3.2 0.50 147 (202) 55.32-ethylbinythagal K 0.250 90.6 88.6 88.6 210 5:10 3.6 0.49 147(205) 57.7M.P.S.=average particle size

Table 2 clearly demonstrates the outstanding improvement in reaction time of the preferred chain transfer agents of the present invention over commonly used commercially available PVC chain transfer agents. Examples 12-14 and comparative examples L-N

These examples use the same procedure as the previous examples, except that the polymerization initiators are changed to demonstrate that the chain transfer agent of the present invention can be used together with a variety of different polymerization initiators. Initiator and CTA concentrations are expressed in weight percent based on VCM. The results are listed in Table 3.

                 Table 3 The effect of using different initiators at a polymerization temperature of 62°C and using perlauric acid as CTA. Condent+Example Number concentration A.O. concentration conversion rate conversion rate C.P.T. 80 % average pressure accumulation m.P.S. K-value C.t.a. ( %) (10-2 %) (weight) ( %) ()) Time density density (μm μM )

(%) (hour:minute) (bar/hour) (gr/cm ³ ) (..)＝d 95 bis(3,5,5-trimethyl L 0.200 1.018 92.0 91.3 192 4:45 3.6 0.50 161(216) 62.2-ylhexanoyl) peroxide + Wushuang (3,5,5-trimethyl-12 0.200 1.018 92.9 91.6 180 4:30 3.4 0.42 163 (222) 56.0-ylhexanoyl) peroxide + perlauric acid 0.250 1.852 tert-butyl Neodecyl peroxide 0.040 0.262 83.0 84.3 193 5:15 1.5 0.47 168(229) 62.3 decanoate + tert-butylperoxy neodecyl 13 0.040 0.262 88.8 88.6 177 4:30 2.5 0.40 162(224) 56.7 ester Perlauric acid 0.250 1.852 bis(4-tert-butyl ring N 0.055 0.221 86.9 88.4 155 4: 25 1.8 0.50 178(249) 61.9 hexyl) peroxydicarbonate + no bis(4-tert-butyl ring 14 0.055 0.221 91.2 91.0 10.0 158 4: 158 2.2 0.44 160 (226) 56.7 hexyl) peroxybicarbonate + perlauric acid 0.250 1.852

A.O. = active oxygen

M.P.S. = mean particle size

These experiments demonstrate that perlauric acid works well as a chain transfer agent with three different peroxide initiators. Examples 15-18 and Comparative Examples O-R

These examples follow the same procedure as the previous examples, except that the polymerization temperature and initiator are varied to demonstrate that the chain transfer agents of the present invention can be used over a wide temperature range. The results are listed in Table 4.

Table 4 uses perlauric acid as CTA, using different initiators at different temperatures Initiator+CTA Example Concentration A.O. Concentration Polymerization k value

No. (%) (10 ^-2 %) Temperature Bis(4-tert-butylcyclohexyl) O 0.07 0.28 53.5 69.0 peroxybicarbonate + no bis(4-tert-butylcyclohexyl) 15 0.07 0.28 53.5 61.3 peroxydicarbonate + peroxybicarbonate Lauric acid 0.25 1.85 2-ethylhexyl peroxide weight P 0.06 0.28 57.0 64.5 carbonate + no 2-ethylhexyl peroxide weight 16 0.06 0.28 57.0 58.7 carbonate + perlauric acid 0.25 1.85 bis(3,5,5-tris Methylhexanoyl Q 0.20 1.02 62.0 62.2 base) peroxide + Wubis (3,5,5-trimethylhexanoyl 17 0.20 1.02 62.0 56.0 base) peroxide + perlauric acid 0.25 1.85 dilauroyl peroxide R 0.10 0.40 68.0 57.2 + no dilauroyl peroxide + 18 0.10 0.40 68.0 53.4 perlauric acid 0.25 1.85

The above-mentioned embodiments are only used to illustrate and illustrate the present invention, but not to limit the present invention in any respect. The scope of the invention is determined by the appended claims.

Claims (8)

1. at least a monomer methods of a free radical (being total to) polymerization, this monomer is selected from vinyl ester, halogen ethene, diolefine, vinyl cyanide and alpha-olefins monomer, can with one or more ethylenically unsaturated monomer copolymerizations, this method is included in a certain amount of at least a peroxy acid chain-transfer agent and exists down, use the described monomeric step of a kind of polymerization starter polymerization, compare with (being total to) polymkeric substance that does not use chain-transfer agent to obtain with same procedure, can reduce the molecular weight of (being total to) polymkeric substance effectively, the described peroxy acid chain-transfer agent that uses in the method is selected from the compound that comprises formula I part:

But condition is this peroxy acid is not to be selected from the unsaturated organo-peroxide that following formula is represented, Ra can improve the alkene unsaturates to the active activating group of free radical addition reaction response in the formula; Rb is that hydrogen and Rc are selected from hydrogen, C ₁-C ₁₈Alkyl, C ₃-C ₁₈Alkenyl, C ₆-C ₁₈Aryl, C ₆-C ₂₂Alkaryl and C ₇-C ₂₂Aralkyl, or Ra and Rc can be in conjunction with forming C ₅-C ₁₀Ring; All Ra, Rb and Rc can be linearity or branching and can be substituted with one or more groups that are selected from hydroxyl, alkoxyl group, aryloxy, epoxy group(ing), halogen, acid, ester, nitrile, ketone and acid amides:

2. the method for claim 1, wherein said peroxy acid chain-transfer agent are selected from the following molecular formula (II) and (III) compound of expression:

Wherein R is selected from group H, CH ₃, C (O) OOH, C (O) OH, C (O) OCH ₃, C (O) OR, C ₂-C ₂₀Alkyl, C ₃-C ₂₀Cycloalkyl, C ₆-C ₂₀Aryl, C ₇-C ₂₀Aralkyl and C ₇-C ₂₀Alkaryl, alkyl wherein can be a straight or branched, wherein alkyl, cycloalkyl, aryl, aralkyl and alkaryl can at random be replaced by one or more Y groups, wherein Y be selected from group-C (O) OOH, hydroxyl, alkoxyl group, aryloxy, epoxy group(ing), halogen ,-C (O) OR ₁,-OC (O) R ₁,-C (O) OH, itrile group, nitro ,-C (O) NR ₁R ₂,-C (O) NHR ₁,-C (O) NH ₂,-N (R ₁) C (O) R ₂,-SO ₂NR ₁R ₂,-SO ₂NHR ₁,-SO ₂NH ₂With-N (R ₁) SO ₂R ₂R wherein ₁And R ₂Be independently selected from group C ₂-C ₂₀Alkyl, C _3-20Cycloalkyl, C ₆-C ₂₀Aryl, C ₇-C ₂₀Aralkyl and C ₇-C ₂₀Alkaryl, alkyl wherein can be straight or brancheds; With R wherein ₃Be selected from hydrogen, C ₁-C ₂₀Alkyl, C ₃-C ₂₀Cycloalkyl, C ₆-C ₂₀Aryl, C ₇-C ₂₀Aralkyl, C ₇-C ₂₀The group of alkaryl and imido-, wherein alkyl can be a straight or branched; R ₄Be selected from group C ₁-C ₂₀Alkylidene group, C ₂-C ₂₀Alkylene group, C ₆-C ₂₀Arylidene, C ₇-C ₂₀Inferior aralkyl, C ₇-C ₂₀Alkarylene, C ₃-C ₂₀Cycloalkylidene and C ₃-C ₂₀Inferior cycloalkenyl group, but wherein alkylidene group and alkylene group straight or branched; R ₃And/or R ₄Can at random be replaced by one or more above-mentioned Y groups; Can there be or be selected from group-SO in X ₂-,-N (R ₅) C (O)-,-C (O) N (R ₅)-,-C (O) N (C (O) (R ₅))-and-NHC (O) N (H)-; R wherein ₅Be selected from group C ₂-C ₂₀Alkyl C _3-20Cycloalkyl, C _6-20Aryl, C _7-20Aralkyl and C ₇-C ₂₀Alkaryl, wherein alkyl can be a straight or branched, and can at random be replaced by one or more above-mentioned Y groups; R ₃And R ₅Can connect to and contain the substituent ring that is selected from cycloalkyl, aryl, aralkyl or alkaryl, this ring can be replaced by one or more above-mentioned Y groups arbitrarily.

3. method as claimed in claim 2, wherein in described chain-transfer agent, R is selected from group C ₃-C ₂₀Alkyl, C ₁-C ₂₀Cycloalkyl, C ₇-C ₂₀Aralkyl and C ₇-C ₂₀Alkaryl, wherein alkyl can be a straight or branched.

4. method as claimed in claim 2, wherein in described chain-transfer agent, R ₃Be selected from the group that contains amido, X can not have or sulfuryl, R ₄Be selected from C ₁-C ₂₀Alkylidene group, C ₆-C ₂₀Arylidene, C ₇-C ₂₀Inferior aralkyl and C ₇-C ₂₀Alkarylene.

5. as any described method among the claim 1-4, wherein said chain-transfer agent is oil-soluble basically.

6. as any described method among the claim 1-4, the consumption of wherein said peroxy acid chain-transfer agent is the 0.001%wt to 30%wt of polymerisable monomer weight.

7. method as claimed in claim 6, wherein said monomer are vinylchlorid.

8. as any described method among the claim 1-4, wherein said polymerization starter is selected from azo initiator, peroxyester, diacyl peroxide and peroxidation heavy carbonic ester.