JPH0428732B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing a polymer, and more particularly to a method for producing an aromatic polymer, particularly an aromatic ketone polymer and an aromatic sulfone polymer. [Prior Art] In research into organic polymers suitable for use at high temperatures, many repeating units containing various linking bonds between aromatic residues, such as imide, ether, sulfone, and ketone bonds, have been used. Linked aromatic structures have been proposed. However, as the high temperature performance potential has increased, the suitability of the polymers for conventional techniques of melt molding them has decreased or disappeared. Elongation of at least 50%, a property required for many polymeric applications (e.g., to allow polymer-insulated wire to be twisted around itself without cracking the insulation). Attempts to produce stable polymers are often accompanied by a similar reduction in melt processability. Aromatic polyketones are known to enjoy relatively good resistance to thermal degradation. In U.S. Pat. No. 3,065,205, Bonner proposed Friedel-Crafts-catalyzed polymerization of specific reactants to obtain polyaryl ketones, and identified ferric chloride and boron trifluoride as typical Friedel-Crafts catalysts. List. The two basic reactions taught by this invention can be summarized as follows: 1 n(HR-O-RH) + n(Cl-A-Cl) → nHCl + H(R-O-R-A) nCl and 2 n (HBH)+n(Cl-A-Cl)→nHCl+Cl(A-B)nH where HBH is a polynuclear aromatic hydrocarbon, such as naphthalene, and HR-O-RH is a diaromatic ether, such as diphenyl ether; and Cl-A-
Cl is diacyl chloride, such as terephthaloyl chloride or phosgene. When phosgene and diphenyl ether react, the resulting polymer contains repeating units of the following structure: From self-condensation of diphenyl ether-4-carbonyl chloride, and diphenyl ether 4,
The same repeat unit resulting from the reaction of 4'-dicarbonyl with diphenyl ether is described in British Patent No. 971,227. Farnham and Johnson in UK Patent No. 1078234 take a different approach. Here, a polyaryl ether is produced by the reaction of a dihalobenzenoid compound and a dialkali metal salt of a dihydric phenol. Dihydric phenols contain keto groups and thus it is stated that 4,4'-dihydroxybenzophenones give rise to polyarylether polyarylketones (see, e.g. claim 15). Another improved method of making polyaryl ketones has been proposed. For example, U.S. Patent Nos. 3,441,538 and 3,442,857 disclose hydrogen fluoride/boron trifluoride catalysts,
Catalysts.etc.) Topchiev et al., Pergamon Press (1959), p. 122; J.Org.Chem. 26 2401 (1961); I&E Chem. Chem.) 43 ,
7461 (1951) has been proposed. Another proposal for an improved method of synthesizing polyaryl ketones is described in GB 1086021. British Patent No. 1086021 discloses that a second compound containing at least two substitutable aromatically bonded hydrogen atoms and a diacid halide (preferably the diacid halide and the second compound are present in substantially equimolar amounts) Friedel-Crafts condensation polymerization of a single compound containing both a halogenated acid group and at least one substitutable aromatically bonded hydrogen atom is described. It is further described that the molecular weight can be adjusted by using non-stoichiometric amounts of the two compounds or by adding a third component that is monofunctional under the conditions of the reaction. Monoacid halides are mentioned as examples of suitable monofunctional molecular weight modifiers. GB 1109842 describes the polymerization reaction of an aryl disulfonyl halide with a compound containing at least two substitutable aromatically bonded hydrogens. As in the embodiment of No. 1086021,
In all examples of this patent, the proposal is to use equimolar amounts of an electrophilic compound and a nucleophilic compound or an excess of an electrophilic compound (i.e., a diacid halide).
Either use. This patent further states that the residual sulfonyl chloride groups on the polymer chain increase the viscosity of the product upon melting, and that the post-polymerization addition of a base such as aniline, sodium carbonate or diphenyl ether can remove residual sulfonyl chloride groups. We propose to quench the group. US Pat. No. 3,593,400 proposes the production of polyaryl ketones with an average intrinsic viscosity of 0.8 to about 1.65 (0.1% W/V in sulfonic acid). Reactivity towards acetylation (compared to benzene reactivity in 1)
This intrinsic viscosity and molecular weight can be adjusted through the use of appropriate amounts of selected nucleophiles and reaction conditions in which the nucleophile is greater than about 150. In addition to melt instability (due to the presence of excess electrophilicity resulting in residual acid halide polymer chain end groups), the presence of excess acid halide groups (i.e., electrophilic compounds) during the polymerization may cause the adjacent This type of structure has been shown to lead to the formation of branched polymers resulting from ortho-acylation of nucleophilic internal segments (e.g. diphenyl ether moieties) in the polymer chain by terminal acid halide groups in the chain. The use of nucleophiles as molecular weight regulators in the polymerization of Linear chain formation occurs while many para positions on the nucleophile are still available, but once the concentration of this position is low, the acylation reaction at the ortho position, which is usually slower, becomes more prominent. It appears to be. This problem is addressed in the U.S. patent of Angelo et al.
Discussed in issue 3767620, this is a repeating structure: 9-phenylenexanthhydrol residue through orthoacylation in the structure of the polymer with Describe the formation of Such residues are formed by the reaction of a diphenyl ether with a diacyl halide, with the acyl halide acylating the diphenyl ether at the ortho position to the oxygen atom of each ring (because essentially all the parenteral positions are (already blocked by a previous acylation). This orthoacylated moiety has been shown to lead to thermal instability, particularly reduced melt processability. Hydrogenation (reduction) of the polymer with ethanol and hydrochloric acid, formic acid, and preferably triethylsilane in a homogeneous acidic medium reduces this degradation, resulting in a gradually stable 9-
Phenylene xanthene residues can be provided. By removing the hydroxyl group and replacing the hydrogen atom, this reduction is said to lead to a product with brighter color and improved melt stability. Treatment of the aforementioned branched polymers dissolved in dichloroacetic acid with triethylsilane is also recommended by Agolino in US Pat. No. 3,668,057 as a means of stabilizing branched chain residues. Of course, if the polymerization is carried out with an excess of nucleophile and/or as proposed in U.S. Pat. No. 3,593,400,
Alternatively, if the molecular weight adjustment is carried out with a nucleophilic compound, there will be an excess of para positions and the branching reaction will not occur to the same deleterious extent. However, when either or both ends of each polymer chain are phenoxy (or other nucleophilic) residues with a para position available for reaction,
It has been found that a hitherto unknown branching reaction preferably takes place in a highly acidic medium such as a hydrogen fluoride/boron trifluoride mixture. This branching is thought to lead to the formation of trisarylcarbonium salts, which combine the carbonyl groups of the polymer itself with the phenoxy (or other nucleophilic) groups (possibly activated, i.e., protonated by the acid medium). ) seems to arise from the reaction. Besides the deleterious effect of branching itself on processability, this salt is very thermally unstable and leads to degradation and coloration of the polymer when melted. As described in U.S. Pat. Thermal stability of polymers produced by Friedel-Crafts condensation polymerization is substantially improved through controlled decomposition of other complexes. However, this post-polymerization treatment does not stop the formation of branched polymer chains by orthoacylation. Furthermore,
This treatment occurs simultaneously with the polymerization reaction itself and can continue as long as the polymer is in a strongly acidic medium and does not inhibit the aforementioned protonated phenoxy group branching reaction catalyzed by strong acids. [Problem to be Solved by the Invention] Friedel produces linear, unbranched products with reproducible molecular weights, stable and predictable melt viscosities, and increased stability in highly acidic solutions. There remains a need for a process for making polyaryl ketones and polyaryl sulfones by a Krafts condensation reaction. As used in this application, the term “acylation” refers to an aromatic nucleophile and a moiety ArCO ⁺
or the reaction ^of ArSO ₂₊ in an acidic medium;
Here, Ar represents a proton monomer or a residue of a polymer chain that continues to undergo polymerization (chain growth) by an acylation reaction. Therefore, acid halides can be partially ArCO ⁺ or
Refers to a reactive compound that forms ArSO ₂ ⁺ . Common examples are Ar-COCl, Ar-COOH and Ar-
Includes COOR and their sulfonyl analogs. [Means for Solving the Problems] One gist of the present invention is that the first monomer is present in excess, and in the presence of 0.002 to 0.10 moles of a nucleophilic capping agent per mole of the first monomer. and at least one first monomer containing a diacid halide group and at least one second monomer containing at least two substitutable aromatically bonded hydrogen atoms. The nucleophilic capping agent is biphenyl, 4-phenoxybenzophenone (provided that the first monomer is isophthaloyl chloride, the second monomer is 1,
When it is 4-diphenoxybenzene, the nucleophilic capping agent is not 4-phenoxybenzophenone. ), 4-thiophenylbenzophenone,
be a compound selected from the group consisting of a mixture of equimolar amounts of diphenyl ether and benzoic acid, and derivatives thereof forming in situ 4-phenoxybenzophenone, 4-thiophenylbenzophenone; A method for producing a polymer characterized by: Another aspect of the invention is that the second monomer is in excess and contains diacid halide groups in the presence of 0.002 to 0.10 moles of electrophilic capping agent per mole of second monomer. Friedel-Crafts condensation polymerization of at least one first monomer containing at least two substitutable aromatically bonded hydrogen atoms, A process for the preparation of a polymer, characterized in that the electrophilic capping agent is a compound selected from the group consisting of benzoic acid, benzenesulfonic acid and the corresponding acid halides. Another aspect of the invention is that the first monomer and the second monomer are present in substantially equimolar amounts, with 0.001 to 0.05 mole of each electrophilic monomer per mole of the first monomer. at least one first monomer containing a diacid halide group and at least one first monomer containing at least two substitutable aromatically bonded hydrogen atoms in the presence of a nucleophilic capping agent and a nucleophilic capping agent. Friedel-Crafts condensation polymerization of a second monomer, wherein the nucleophilic capping agent is biphenyl, 4-phenoxybenzophenone, 4-thiophenylbenzophenone, equimolar electrophilic compound selected from the group consisting of a mixture of a quantity of diphenyl ether and benzoic acid and its derivatives forming in situ 4-phenoxybenzophenone, 4-thiophenylbenzophenone; A process for producing a polymer, characterized in that the capping agent is a compound selected from the group consisting of benzoic acid, benzenesulfonic acid and the corresponding acid halides. By the method of the invention, for example, compounds of the formula: [-M-Ar-B-Ar']- (wherein -M- and -B- may be the same or different and each represent -CO- or -SO ₂ - represents
Ar is

[Formula] or

[Formula] (Here, -L- represents -CO-, -SO ₂ -, covalent bond, or -T-, where -T- represents -O-,
-S-, phenyleneoxy, -O-Ar-O-, or _CR2 , each R may be the same or different and is substituted with hydrogen, an alkyl or fluoroalkyl group, an unsubstituted phenyl group, or an electron-withdrawing group. It is a phenyl group. ), and Ar′ is represents. ), and has both terminal groups represented by the formula R' or R'', each R' and R'' having the formula:

[Formula] -CO-Ar'' or -SO ₂ -Ar'' (wherein -X- is a covalent bond, -O- or -S-;
Y is

[Formula] or when -X- represents a covalent bond, it represents hydrogen; Ar'' represents a phenyl group.
An essentially linear polymer is obtained. Preferably the alkyl or fluoroalkyl group constituting R contains 1 to 10 hydrogen atoms. The repeating units in the resulting polymer advantageously consist essentially of repeating units of the formula: [-M-Ar-B-Ar']-, and the polymer is advantageously substantially linear and advantageously is a homopolymer. However, the polymer may also contain units not specified above,
This additional unit is an unrelated structure or unit [-M-Ar-
Any structure derived from B-Ar']-, but of trivalent or other higher valence.
The polymer may also contain two or more identical units represented by the general formula: [-M-Ar-B-Ar']- in combination with other unrelated repeating units. Preferably, Ar′ is and when T is -O-Ar-O-, the Ar segment of the T part is [-M-Ar-B-
Ar'] - different from the Ar segment in the unit. Mixtures of two or more nucleophilic or electrophilic capping agents can be used. In this polymer, all the end groups are formed from electrophilic capping agents or nucleophilic capping agents, or some are formed from electrophilic capping agents and some from nucleophilic capping agents. good. In the preferred case where the polymer is linear, depending on the polymerization reaction used, each chain has both end groups formed from electrophilic or nucleophilic capping agents, or from electrophilic capping agents. The capping agent has one end group formed from a nucleophilic capping agent and the other end group formed from a nucleophilic capping agent. Although in most cases the polymer chain has two ends (i.e., is linear), in some situations, for example to produce a melt processable polymer with high melt strength, three or more It is preferred to provide polymers having chains with terminal ends, i.e. with long chain branching, and in this case the present invention caps the term "double" or "doubly". It will be recognized by those skilled in the art that it is intended to cap all ends of the molecule, even if used as a compound. Specific examples of suitable diacid halide first monomers are terephthaloyl chloride, isophthaloyl chloride, oxy-bis(4,4-benzoyl chloride), diphenylmethane-4,4'-di(carbonyl chloride). , phosgene, benzene
1,4-di(sulfonyl chloride), benzene-1,3-di(sulfonyl chloride), 2-chlorobenzene-1,4-disulfonyl chloride, thio-bis(4,4'-benzoyl chloride), oxy-bis (4,4'-benzenesulfonyl chloride), benzophenone-4,4'-di(carbonyl chloride), oxy-bis(3,
3'-benzoyl chloride), thio-bis(3,
3′-benzenesulfonyl chloride), oxy-
bis(3,3'-benzenesulfonyl chloride),
Diphenyl-3,3'-di(carbonyl chloride), benzophenone-3,3'-di(carbonyl chloride), sulfonyl-bis(4,4'-benzoyl chloride), sulfonyl-bis(3,
3'-benzoyl chloride), sulfonyl-bis(3,4'-benzoyl chloride), thio-bis(3,4'-benzoyl chloride), diphenyl-
3,4'-di(carbonyl chloride), oxy-
Bis[4,4'-(2-chlorobenzoyl chloride)], naphthalene-1,6-di(carbonyl chloride), naphthalene-1,5-di(carbonyl chloride), naphthalene-2,6-di(carbonyl chloride) ), naphthalene-1,5-di(sulfonyl chloride), oxy-bis-[7,7'-
Naphthalene-2,2'-di(carbonyl chloride)], Thio-bis-[8,8'-naphthalene-1,
1′-di(carbonyl chloride)], 7,7-binaphthyl-2,2′-di(carbonyl chloride),
diphenyl-4,4'-di(carbonyl chloride), carbonyl-bis[7,7'-naphthalene-
2,2'-di(carbonyl chloride)], sulfonyl-bis[6,6'-naphthalene-2,2'-di(carbonyl chloride)] and dibenzofuran-
Examples include, but are not limited to, 2,7-di(carbonyl chloride). Examples of suitable second monomers containing at least two substitutable aromatically bonded hydrogen atoms include 4,4'-diphenoxybenzophenone, 1,
4-diphenoxybenzene, diphenyl sulfide, p-phenoxyphenol, p-phenylphenol, dibenzofuran, thianthrene, phenoxatin, phenodioxin, 4,4'-diphenoxybiphenyl, 2,2 '-diphenoxybiphenyl, 1,2-diphenoxybenzene, 1,3-
Diphenoxybenzene, 1-phenoxynaphthalene, 1,2-diphenoxynaphthalene, 1,5-
Diphenoxynaphthalene, diphenylmethane,
Examples include, but are not limited to, 2,2-diphenylhexafluoropropane, triphenylmethane, and 4-nitrophenyldiphenylmethane. The novel multi-capping process of the present invention produces multi-capped polymers that have excellent high temperature stability and are melt-formable, particularly extrudable products suitable for applications such as wire and cable insulation. provide. Advantageously, the polymer chain length is from about 5 to about 500,
Preferably it is within the range of about 20 to about 300. Additionally, the polymers of the present invention can be molded by conventional injection molding techniques. Furthermore, these polymers are substantially free of unmodified chain branching; modified chain branching is obtained as described below. The polymers produced by the method of the invention are characterized by a light color and excellent thermal stability. Furthermore, they form stable solutions even in highly acidic media such as hydrogen fluoride/boron trifluoride mixtures.
Furthermore, solutions of the polymers according to the invention in sulfuric acid are light colored, whereas solutions of the corresponding polymers prepared by a method different from the invention are very colored. Furthermore, these polymers are essentially inert for further reaction with either electrophilic or nucleophilic agents, so that they can be dissolved in solution within the reactor (e.g., on the walls of the reactor) after the completion of one polymerization. Residual polymer left behind does not need to be washed before starting another polymerization. The residual polymer must be completely removed from the reactor before the next polymerization is carried out, since in prior art processes its presence results in the production of very high molecular weight fractions in the product of the next polymerization. Additionally, as noted above, polymer solutions prepared by prior art techniques have an undesirable tendency to increase molecular weight on storage. To facilitate a fuller understanding of the invention:
It is appropriate to distinguish between terms that are often and commonly incorrectly used interchangeably in the prior art with respect to Friedel-Crafts catalyzed polymerization. The term "quenching agent" is almost always added in substantial excess to the polymerization reaction mixture after completion of the polymerization reaction in order to react with the polymer endgroup-catalyst complex, so that the polymer molecules are It means a compound, usually a Lewis base (nucleophilic), which makes it substantially less likely to undergo further undesirable reactions. This reaction is effected by chemical bombardment of the reactive polymer end groups onto adjacent molecules with which the polymer molecules come into contact during subsequent processing or use. In contrast, having a molar excess of either nucleophilic or electrophilic bifunctional reactants during the polymerization and preferably from the initiation of the polymerization or at any time before the completion of the polymerization reaction conditions Molecular weight adjustment is generally carried out by adding nucleophilic or electrophilic reagents which are monofunctional and thus serve as chain terminators. Of course, this chain terminator is also useful when carrying out polymerizations using monomers having both electrophilic and nucleophilic moieties on the same molecule. Of course, it is clear that the quenching agents can be used suitably in combination with molecular weight modifiers. Capping agents, which can be either electrophilic or nucleophilic, function differently than either quenching or molecular weight modifiers. The purpose is to form groups at all (or both, in the case of linear molecules) ends of the polymer molecule and thereby make the end groups of the polymer molecule at least as resistant to chemical attack as the rest of the molecule. It lies in making it seem like it is a gender. Its main action is not to stop the polymerization; in fact, unlike a quencher, it may be present in the polymerization mixture throughout the polymerization reaction. Compounds that act as capping agents as defined above may, under certain circumstances, perform a molecular weight regulating function or, contrary to the teachings of the present invention,
It should be noted that if added in excess, the reaction can be stopped in some cases. However, under conditions that result in polymer molecules that are reactive, i.e., uncapped at at least one end as defined below, the prior art has consistently used either electrophilic or nucleophilic molecular weight modifiers. There is. for example,
GB 1387303 contains a discussion of the use of so-called capping agents in connection with polymerization reactions similar to those described herein. However, it should be noted that in the context of this patent, the so-called capping agents are actually molecular weight modifiers that act in their own right and are not true capping agents as described herein. actually,
Prior art agents cannot actually achieve the objectives of the present invention when used as described in the aforementioned British patent. In fact, the nature and significance of multiple capping as described and claimed herein was not recognized at the time of the aforementioned British patent. The present invention contemplates the use of capping agents to provide a polymer molecule that is non-reactive and resistant to chemical attack at both ends of the molecule. The use of quenching and/or molecular weight modifiers as defined above in conjunction with capping agents does not provide any useful effect and is in some cases harmful. The distinction between quenching agents and capping agents is to think of the former as reducing the tendency of polymers to attack other molecules, including monomers or oligomers, which are less reactive than polymers, whereas the latter Coalescence can be shown to increase the resistance of the polymer to attack by more reactive species. Since the quencher is only added after the total polymerization is complete, the use of a molecular weight regulator without a capping agent will result in any polymerization reaction mixture in which growth is stopped by the molecular weight regulator, but will nevertheless degrade. This means that there are a significant number of "completed" molecules that are sufficiently unstable to undergo extinction before extinction.
Of course, other molecules are still undergoing polymerization, so it is impractical to render these completed molecules inactive by adding a quenching agent.
Therefore, when the polymerization reaction is finally quenched, it will contain a significant proportion of molecules whose chain growth was initially completed and subsequently degraded. This problem
This is evident when highly reactive catalysts such as HF- _BF3 are used. This is one of the problems unexpectedly solved by the present invention. With this background, the use of the present invention to provide controlled branching can be more easily understood. If the polymerization uses equimolar amounts of the first monomer and the second monomer, molecular weight modifiers with more than two chain initiation sites are used, branching occurs, and capping occurs. The nature and mole percentage of the agent is influenced by the number of starting positions. For example, if the molecular weight modifier is nucleophilic, the end capping agent should be electrophilic and present in a percentage molar ratio equal to the number of initiation positions. Branching also occurs when electrophilic capping agents with polyfunctionality are used, since this caps several growing chains; in combination, molecular weight modifiers are used. If the molecular weight regulator is initiated only on one side and is unreactive on the other side, a single branching position will occur on each molecule, which is suitable. Alternatively, but not preferred, if the molecular weight modifier is polyfunctional and can initiate on one side but is still reactive on the other side, more branching will occur and polyfunctional capping agents may be used. If so, it will likely lead to undesirable gelation. In this case, it is advantageous to use both a monofunctional capping agent and a polyfunctional capping agent, with the ratio of the concentration of the monofunctional capping agent to the concentration of the polyfunctional capping agent being equal to the functionality of the former. It is. If the molecular weight modifier is electrophilic, the capping agent should be nucleophilic. Similar considerations apply if the first and second monomers are not in equimolar amounts, provided that both the capping agent and the molecular weight modifier are electrophilic monomers in excess. may be nucleophilic and vice versa. However, although the invention can be used to provide polymers with controlled branching, the preferred products of the invention are essentially linear polymers; an advantage of the process of the invention is that the resulting Includes reproducibility of coalescence and the ability to produce polymerizations of desired chain lengths and thus specific viscosities. The polymer to which this invention is particularly concerned has the structural formula: polyarylketones containing repeating units of, ie, poly(benzophenone ether). Particularly preferred are those having this repeating unit and about 0.8
Homopolymers and copolymers having an average intrinsic viscosity within the range of from about 1.65 to about 1.65 are included. This polymer and its method of preparation are described in British Patent No. 1387303. Second, repeat unit:

[Formula] and and in particular homopolymers of p-biphenylyloxybenzoyl monomer, and also copolymers thereof with small amounts of the corresponding o-comonomer, having an average molecular weight of from about 0.5 to about 1.7. Particularly preferred are polymers with an intrinsic viscosity. Similar polymers and methods of their preparation are described in US Pat. No. 3,593,400. The present invention also relates to sulfonyl analogs of the polyaryl ketones described above, and U.S. Pat.
3442857, 3321449 and other polymers and corresponding processes for their manufacture as described in Goodman British Patent No. 971227 and Jones No. 1016245, is hereby incorporated by reference to avoid unnecessary enlargement of the present specification. Particularly useful solvents for use in this polymerization include nitrobenzene, o-dichlorobenzene, sym-tetrachloroethane, methylene chloride, mixtures of any of the foregoing, and also anhydrous hydrogen fluoride. Common Friedel-Crafts catalysts are suitably used in the polymerization process, such as aluminum chloride, aluminum bromide, boron trifluoride, hydrogen fluoride, ferric chloride,
Contains stannic chloride, indium chloride and titanium tetrachloride. Aluminum chloride, indium chloride, and ferric chloride are preferred catalysts, and mixtures of hydrogen fluoride and boron trifluoride are particularly suitable. For example, the amount of suitable catalysts such as aluminum chloride and boron trifluoride is usually at least one molar equivalent per carbonyl or sulfonyl group of the monomeric reactant. In the case of ferric chloride or indium, up to 1 molar equivalent is usually used. The polymers to which this invention relates are produced by polycondensation. two monomeric starting materials, a first monomeric reactant which is an electrophile and is generally a diacid halide, and at least two displaceable aromatically bonded hydrogen atoms; , there is a second monomeric reactant that is a nucleophile. [EE] is the molar concentration of the electrophile,
[NN] is the molar concentration of the nucleophile, and
When EE is in excess, the molecular weight of the resulting polymer, MW, is determined by the formula: MW = [EE] + [NN] / [EE] - [NN] x W/2 (where W is the repeating rate of the polymer). unit (i.e.
is the molecular weight of the EENN residue). Therefore, the use of excess EE provides molecular weight adjustment. Conversely, if NN is in excess to adjust the molecular weight, the molecular weight is equal to [NN] + [EE]/[NN] - [EE] x W/2. When EE is in molar excess, the polymer chains readily react with branched polymer chains and acid halide ends leading to instability of the polymer when melted, as is also well known to those skilled in the art. It shows a tendency to have groups. If NN is used in excess to effect molecular weight adjustment and the NN is at least at one end of the polymer chain due to the phenoxy group or excess NN, it contains a group similar to the phenoxy group in its reactivity towards acylation. It was unexpectedly found that reaction of these end groups with ketone catalyst complexes during or after polymerization tends to cause branching, possibly through the formation of trisarylcarbonium ionic salts. . Furthermore, molecular weight adjustment by addition of a monofunctional molecular weight adjustment compound to a stoichiometric mixture of starting materials may further increase the end groups depending on whether the monofunctional reagent is electrophilic or nucleophilic. Each polymer molecule has an electrophilic or nucleophilic group at the end of the polymer molecule away from the molecular weight modifier residues that react and cause chain branching, thus preventing either of the above problems. It turns out it can't be done. The molecular weight of the resulting polymer is determined by the formula: MW = [C] x W/[T], where [C] = [NN] = [EE], and [T] is the molar concentration of the molecular weight modifier used. , and W is the molecular weight of the repeating unit of the polymer). Thus, the use of excess nucleophilic monofunctional molecular weight modifiers to control the molecular weight of the polymer does not in any way address the problem of polymer stability that is the object of this invention.
Or it is clear that it will not be resolved. Accordingly, the present invention provides Friedel-Crafts condensation polymers in which the molecule is capped at both ends by groups that do not serve as branching initiators under the polymerization conditions. Either the electrophilic or nucleophilic agent can be present in excess or in equimolar amounts. In the first and second cases the molecular weight is adjusted by the excess of reactants as described above. In the first case, the nucleophilic capping agent effectively caps both ends of the polymer chain. In the second case, the electrophilic capping agent caps both ends of the polymer molecule. When equimolar amounts of electrophilic and nucleophilic capping agents are present, the electrophilic and nucleophilic capping agents are added and the polymer chain is capped at one end by the nucleophilic cap and at the other end. It is capped by an electrophilic cap. Another advantage of the invention is that in this situation the capping agent serves an additional function of the molecular weight modifier. The electrophilic polymer end cap for polymers made according to the present invention has the structure: Ar″CO- or Ar″SO ₂ −, where Ar″ is a phenyl group. The structure of the combined end cap is: [In the formula, -X- is a covalent bond, -O- or -S-;
Y is

When [Formula] or -X- represents a covalent bond, it represents hydrogen. ]. The preferred ratios of the components are as follows: Case a [EE] > [NN] Mole fraction of difunctional electrophile [EE]: 1 Mole fraction of difunctional nucleophile [NN]: 1-a Mole fraction of nucleophilic capping agent: 2a Case b [NN] > [EE] Mole fraction of difunctional electrophile [EE]: 1 Mole fraction of difunctional nucleophile [NN] Rate: 1 + a Molar fraction of electrophilic capping agent: 2a Case c [NN] = [EE] Molar fraction of difunctional reagent (EE & NN): 1 Molar fraction of nucleophilic capping agent: a Electrophilicity Mole fraction of capping agent: a In cases a and b, the capping agent can be added at any stage of the polymerization, including after the polymerization is complete, and no separate molecular weight modifier is required. In case c, one of the capping agents also acts as a molecular weight regulator and is therefore preferably added early in the polymerization, optimally at the beginning of the reaction. In contrast, other capping agents can be added at any time. It may be nucleophilic, preferably electrophilic. Preferably in all three cases,
Capping agents are added at the beginning or early in the polymerization. Although it is often difficult in practice to precisely select the same amount of each capping agent, it has been found that extreme precision is not necessary. If it is not possible to provide exactly the same amount of electrophilic and nucleophilic capping agent, it may be desirable to use only a slight excess of nucleophilic agent. The value of a can vary from about 0.001 to about 0.05, preferably from 0.002 to 0.01, based on the value of 1 for the monomers listed above. As mentioned above, the capping agents used in the practice of this invention can be either nucleophilic or electrophilic. The nucleophilic capping agent is biphenyl, 4-phenoxybenzophenone, 4-thiophenylbenzophenone, or an equimolar mixture of diphenyl ether and benzoic acid or in situ 4-phenoxybenzophenone, Including its derivatives forming 4-thiophenylbenzophenone. Electrophilic capping agents include benzoic acid, benzenesulfonic acid or the corresponding acid halides. The polymers of the present invention preferably have a viscosity ranging from about 0.5 to 2.0 and contain from about 5 to about 300 repeat units. Clearly, polymers can be made according to the teachings of the present invention by using mixtures of electrophilic and nucleophilic difunctional monomers. [Preferred Embodiments of the Invention] Next, the present invention will be explained with reference to Examples. All parts are by weight and temperatures are in °C unless otherwise noted. Throughout, the average intrinsic viscosity is the Preparative of Sorensen et al.
Methods of Polymer Chemistry, Interscience (1968) p. 44 [Concentrated sulfuric acid solution 100% at 25°C]
0.1 g of polymer in ml]. Example 1 4,4'-diphenoxybenzophenone (4.95 mmol), terephthaloyl chloride (5.00 m
mol) and p-phenoxybenzophenone (0.1 mmol). To this mixture was gradually added 10 ml of anhydrous hydrogen fluoride. This tube was then connected to a nitrogen purged polychlorotrifluoroethylene vacuum line (Toho Kasei Co., Osaka, Japan). Boron trifluoride gas was introduced and the reaction mixture was maintained at 2.1 Kg/cm ² pressure for 4 hours to obtain a viscous orange solution. After cooling to -78°C, excess boron trifluoride was purged from the reaction system. The polymer solution was diluted with aqueous hydrogen fluoride and then poured into rapidly stirred water. The resulting polymer precipitate was filtered and washed with water, followed by drying at 120° C./20 mm Hg to yield a light colored fluffy material with an average intrinsic viscosity of about 1.36. The polymer formed a stable solution with hydrogen fluoride. Example 2 Using the same equipment and process as in Example 1, 4.
4′-diphenoxybenzophenone (5.0 mmol),
A mixture of terephthaloyl chloride (4.95 mmol) and benzoic acid (0.1 mmol) was polymerized to give an average intrinsic viscosity of approx.
A polymer of 1.36 was obtained.

Claims (1)

[Claims] 1. The first monomer is present in excess, and the first monomer 1
at least one first monomer containing a diacid halide group and at least two substitutable aromatically bonded hydrogen atoms in the presence of 0.002 to 0.10 moles per mole of a nucleophilic capping agent. Friedel-Crafts condensation polymerization of at least one second monomer contained therein, wherein the nucleophilic capping agent is biphenyl, 4-phenoxybenzophenone (provided that the first monomer is isophthaloyl chloride, the second monomer is 1,
When it is 4-diphenoxybenzene, the nucleophilic capping agent is not 4-phenoxybenzophenone. ), 4-thiophenylbenzophenone, a mixture of equimolar amounts of diphenyl ether and benzoic acid and in situ 4-phenoxybenzophenone, 4
- A process for producing a polymer, characterized in that it is a compound selected from the group consisting of derivatives thereof forming thiophenylbenzophenone. 2. The method according to claim 1, wherein the capping agent is added at the beginning of the polymerization. 3. The method according to claim 1 or 2, which is carried out in the presence of a HF/BF ₃ catalyst. 4. The method according to any one of claims 1 to 3, wherein the produced polymer is a homopolymer. 5. The method according to any one of claims 1 to 4, wherein the produced polymer is linear. 6 The second monomer is in excess, and the second monomer 1
at least one first monomer containing a diacid halide group and at least two substitutable aromatically bonded hydrogen atoms in the presence of 0.002 to 0.10 mole per mole electrophilic capping agent. Friedel-Crafts condensation polymerization of at least one second monomer containing the electrophilic capping agent selected from the group consisting of benzoic acid, benzenesulfonic acid and corresponding acid halides. A method for producing a polymer characterized by being a compound. 7. The method according to claim 6, wherein the capping agent is added at the beginning of the polymerization. 8. The method according to claim 6 or 7, which is carried out in the presence of a HF/BF ₃ catalyst. 9. The method according to any one of claims 6 to 8, wherein the produced polymer is a homopolymer. 10. The method according to any one of claims 6 to 9, wherein the produced polymer is linear. 11 The first monomer and the second monomer are present in substantially equimolar amounts, with an electrophilic capping agent and a nucleophilic capping agent of 0.001 to 0.05 mole each per mole of the first monomer. at least one first monomer containing a diacid halide group and at least one second monomer containing at least two substitutable aromatically bonded hydrogen atoms in the presence of a capping agent. the nucleophilic capping agent is biphenyl, 4-phenoxybenzophenone, 4-thiophenylbenzophenone, equimolar amounts of diphenyl ether and benzoin. selected compounds consisting of a mixture of acids and derivatives thereof forming in situ 4-phenoxybenzophenone, 4-thiophenylbenzophenone, wherein the electrophilic capping agent is benzoic acid; , benzenesulfonic acid and the corresponding acid halides. 12. The method according to claim 11, wherein the capping agent is added at the beginning of the polymerization. 13. The method according to claim 11 or 12, which is carried out in the presence of a HF/ _BF3 catalyst. 14. A method according to any of claims 11 to 13, wherein the electrophilic capping agent and the nucleophilic capping agent are present in substantially equimolar amounts. 15. The method of claim 14, wherein each of both reagents is present in an amount of 0.002 to 0.01 mole per mole of monomer. 16. The method according to any one of claims 11 to 15, wherein the produced polymer is a homopolymer. 17. The method according to any one of claims 11 to 16, wherein the produced polymer is linear.