JP2865780B2 - Polymer compound and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention relates to a novel polymer compound having a large number of carbonyl groups in a molecular chain and having extremely high reactivity. Further, the present invention also provides an excellent method for producing the novel polymer compound.

B. Prior Art Many researchers have conventionally attempted to introduce a carbonyl group into a polymer compound to synthesize a polymer compound having high reactivity. For example, it has long been known that polyvinyl ketone is synthesized by radical polymerization of vinyl alkyl ketone. However, in this method, many carbonyl groups are introduced into the molecule, but the position of introduction of the carbonyl group is not directly connected to the main chain, and the desired high reactivity is desired because the carbonyl groups are not conjugated. At present, it has not been obtained and has not yet been industrialized.

Also, another attempt has been made to synthesize polyvinyl alcohol having a carbonyl group by oxidizing the hydroxyl group of polyvinyl alcohol with an oxidizing agent. For example, a method of oxidizing polyvinyl alcohol with sodium hypochlorite is well known. However, this method has a problem that the 1,2-glycol bond in the polyvinyl alcohol is oxidatively cleaved, resulting in a significant decrease in the degree of polymerization and generation of an aldehyde group. For example, Polym. Sci. Technol., 21 , 75 (1983) describes the oxidation reaction of polyvinyl alcohol using sodium hypochlorite. Only those having a viscosity of 0.235 dl / g or less are disclosed. When the intrinsic viscosity of the polymer compound after oxidation is extremely low, such as 0.235 dl / g or less, there is a problem that the film strength of the polymer compound is low and its usefulness is practically low.

As described above, at present, there is no satisfactory method for synthesizing a polymer compound containing a large number of carbonyl groups in the main chain.

The present inventors have already reported a method for synthesizing a polymer compound containing less than 40 mol% of carbonyl groups in the main chain by oxidizing polyvinyl alcohol using an oxoaminium salt as an oxidizing agent (Makromol. Chem., Rapid Commun., 9 , 20
3 (1988)). This method has no undesirable side reactions,
Further, since there is no decrease in the degree of polymerization, this is an extremely excellent method for providing a polymer compound containing a carbonyl group in the main chain.
However, in this method, the carbonyl group in the obtained polymer compound is at most 39 mol%, and it is impossible at present to introduce a carbonyl group of 45 mol% or more.

C. Problems to be Solved by the Invention As described above, since a main chain contains 45 mol% or more of carbonyl groups and there is no undesirable side reaction, there is no decrease in the degree of polymerization, and undesired aldehyde groups, etc. At present, a polymer compound containing no group has not yet been obtained, and development of a method for synthesizing such a polymer compound has been awaited.

D. Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, succeeded in synthesizing a polymer compound containing a carbonyl group of 45 mol% or more in the main chain. Was completed.

That is, the polymer compound obtained in the present invention has a content of the structural unit represented by the formula (I) of 45 to 85% by mole, a content of the structural unit represented by the formula (II) of 1 to 54.99% by mole, (III)
Consisting of 0.01 to 54 mol% of the content of the structural unit represented by
It is a polymer compound having an intrinsic viscosity (hereinafter, abbreviated as intrinsic viscosity) of not less than 0.25 dl / g measured in dimethyl sulfoxide at 30 ° C.

(However, R ₁ represents hydrogen or an alkyl group having 1 to 10 carbon atoms.) In the polymer compound obtained in the present invention, R ₁ of the structural unit represented by the formula (III) is hydrogen or 1 to 10 carbon atoms. In general, a methyl group is preferably used.

The content of the structural unit represented by the formula (I) in the polymer compound obtained in the present invention is from 45 mol% to 85 mol%. When the content of the structural unit represented by the formula (I) is less than 45 mol%, it is not preferable because an extremely strong reactivity by the carbonyl group of the present invention cannot be obtained. Further, the content of the structural unit represented by the formula (I) cannot exceed 85 mol%.

The content of the structural unit represented by the formula (II) in the polymer compound obtained in the present invention is from 1 to 54.99 mol%, and the content of the structural unit represented by the formula (III) is from 0.01 to 54. Mol%
It is.

The intrinsic viscosity of the polymer compound obtained in the present invention is 0.25 dl / g
The above, more preferably 0.3 dl / g or more. Intrinsic viscosity
When it is less than 0.25 dl / g, the film strength of the polymer compound becomes too low, so that it is not used in the present invention. There is no particular upper limit of the intrinsic viscosity, but if the intrinsic viscosity is too high, the handleability of the polymer compound deteriorates, preferably 15 dl / g or less,
It is more preferably at most 8 dl / g, most preferably at most 5 dl / g.

The novel polymer compound of the present invention may contain a small amount of units other than the structural units represented by the formulas (I), (II) and (III) in the molecule. As a method for introducing such a unit, it is conceivable to copolymerize a monomer capable of undergoing radical copolymerization with a fatty acid vinyl and to introduce a carbonyl group by the oxidation reaction of the present invention after saponification. Specific examples of such a monomer include, for example, ethylene propylene
Α-Olefins such as isobutene / dodecene; carboxyl group-containing monomers such as maleic anhydride / maleic acid / fumaric acid / itaconic acid / crotonic acid; alkyl esters / salts thereof; (meth) acrylic acid / alkyl esters thereof (Meth) acrylates such as salts thereof, (meth) acrylamide, N, N-dimethyl- (meth) acrylamide, N-methylol (meth) acrylamide, etc.
Acrylamides, cationic group-containing monomers such as 3- (meth) acrylamido-propyltrimethylammonium chloride, vinyl sulfonic acid, (meth) allylsulfonic acid, 2- (meth) acrylamidopropyl-2-methylpropanesulfonic acid, etc. Sulfonic acid group-containing monomer, styrene, halogen-containing monomer such as vinyl fluoride / vinyl chloride / vinylidene chloride, silane group-containing monomer such as triethoxyvinylsilane / trimethoxyvinylsilane, t-butyl vinyl ether / methyl vinyl ether And vinyl ethers such as N-vinyl-2-pyrrolidone.

Next, the production method of the present invention will be described. The production method of the present invention comprises the steps of: preparing a solution of polyvinyl alcohol having a degree of saponification of 20 mol% or more in a solution in the presence of a perchlorate or a carbonate in the presence of a,
A method for producing a polymer compound comprising structural units represented by formulas (I), (II) and (III), characterized by oxidizing using a tetraalkyloxoaminium salt.

If the degree of saponification of the polyvinyl alcohol used is lower than 20 mol%, the oxidation by the oxoaminium salt becomes difficult to progress, so it is necessary that the saponification degree is 20 mol% or more, and 50 mol% or more.
Or more, more preferably 70 mol% or more.

There is no particular limitation on the degree of polymerization of the polyvinyl alcohol used. In the method for producing the polymer compound of the present invention, there is no substantial reduction in the degree of polymerization due to side reactions during the production,
The degree of polymerization of the polyvinyl alcohol used directly becomes the degree of polymerization of the novel polymer compound of the present invention after production.

The polyvinyl alcohol used in the present invention may contain other units in a small amount. As a method for introducing such a unit, as described above, it is conceivable that a radically copolymerizable monomer is copolymerized with a fatty acid vinyl, and after the saponification, a carbonyl group is introduced by the oxidation reaction of the present invention. Specific examples of such a monomer are as described above.

The α, α′-tetraalkyloxoaminium salt used in the present invention is not particularly limited as long as it is a dialkyl-substituted oxoaminium salt at the α-position and α′-position. 1-4 alkyl groups are used, and a methyl group is often used. Preferably, the nitrogen atom of the oxoaminium salt is located in the cyclic skeleton, and among them, the 1-oxopiperidinium skeleton is most preferable. Regarding the 1-oxopiperidinium skeleton, those having other substituents in addition to the α, α′-position of the nitrogen atom, that is, the tetraalkyl groups at the 2- and 6-positions can also be used. Examples of such a substituent include an alkoxy group, an ester group, an amino group, an amide group, and a carbonyl group. Further, the 1-oxopiperidinium skeleton may be bonded to the polymer compound via an amide group or an ester group. As a counter anion of the oxoaminium salt, a halogen anion such as a fluoride ion, a chloride ion, a bromine ion, and an iodine ion is used. Of these, a chloride ion and a bromine ion are preferable, and a chloride ion is most preferable. Specific examples of such oxoaminium salts include, for example, 2,2,6,6-tetramethyl-1-oxopiperidinium chloride, 2,2,6,6-tetramethyl-1-oxopiperidinium chloride Bromide, 4-methoxy-2,2,6,6-
Tetramethyl-1-oxopiperidinium chloride, 4
-Methoxy-2,2,6,6-tetramethyl 1-oxopiperidinium bromide, 4-oxo-2,2,6,6-tetramethyl-1-oxopiperidinium chloride, 4-oxo-
2,2,6,6-tetramethyl-1-oxopiperidinium bromide and the like.

The amount of the oxoaminium salt used in the present invention is not particularly limited. However, since the oxidation reaction of the present invention proceeds stoichiometrically, it is usually used in an amount equal to or more than the carbonyl group to be introduced. Further, if necessary, as described by the present inventors (J. Mol. Catal., 32 , 357 (1985)), the catalyst may be used in combination with an oxidizing agent such as a salt of divalent copper. If a system is constructed, the amount of the oxoaminium salt used can be made equal to or less than the equivalent amount.

In the present invention, the oxidation reaction proceeds easily by dissolving polyvinyl alcohol in a solvent and adding an oxoaminium salt thereto. The solvent used may be any solvent that can dissolve both polyvinyl alcohol and oxoaminium salt. Specific examples of such a solvent include water and N.
-MethylpyrrolidoneN, N-dimethylformamideN, N
Amides such as dimethylacetamide and sulfoxides such as dimethylsulfoxide. In addition, if necessary, a solvent such as ethers, ketones, esters, halogenated carbon, aromatic hydrocarbon, or aliphatic hydrocarbon is used together within a range in which both the polyvinyl alcohol and the oxoaminium salt are soluble. You can also.

The concentration of the polyvinyl alcohol used in the oxidation reaction is not particularly limited. However, if the concentration is too high, the viscosity of the solution becomes too high to make it difficult to handle, so that a concentration of usually 50% or less, preferably 30% or less is selected.

Although the temperature of the oxidation reaction is not particularly limited, it is usually −78 ° C. to 20 ° C.
0 ° C, preferably 0-100 ° C, more preferably 5-50 ° C
Is selected from the range.

The temperature of the oxidation reaction is not particularly limited, but is appropriately selected usually in the range of 1 minute to 1 week, preferably 1 hour to 3 days.

The oxidation reaction of the present invention may be carried out in air, but is usually carried out in an atmosphere of an inert gas such as nitrogen gas or argon gas.

The present inventors have found that when perchlorates and carbonates are used together during the oxidation reaction, the oxidation reaction proceeds extremely efficiently, and surprisingly, the introduction rate of the carbonyl group is increased. The method was established. Specific examples of such perchlorates include lithium perchlorate.
Examples thereof include alkali metal salts such as sodium perchlorate and potassium perchlorate, alkaline earth metal salts such as magnesium perchlorate and aluminum perchlorate, and ammonium salts such as ammonium perchlorate. Specific examples of carbonates include alkali metal salts such as lithium carbonate, sodium carbonate and potassium carbonate, alkaline earth metal salts such as magnesium carbonate and aluminum carbonate, and ammonium salts such as ammonium carbonate. The amount of such a perchlorate or carbonate added is usually preferably 0.1 to 10 equivalents to the hydroxyl group of polyvinyl alcohol.

E. Examples Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto. In the following, “parts” or “%” means “parts by weight” or “% by weight” unless otherwise specified.

Example 1 Ten parts of polyvinyl alcohol having a saponification degree of 88.5 mol% and an average polymerization degree of 1750 were dissolved in 490 parts of N-methyl-2-pyrrolidone at 150 ° C under a nitrogen stream, and then cooled. 68 parts of magnesium perchlorate and 49 parts of 4-methoxy-2,2,6,6-tetramethyl-1-oxopiperidinium chloride are added thereto, and covered so that light does not enter. For 24 hours to carry out an oxidation reaction. The reaction product was poured into a large amount of diethyl ether, and the polymer compound to be precipitated was dissolved in dimethyl sulfoxide, and then poured into a large amount of acetone to precipitate again. This reprecipitation purification was repeated five times to completely remove the oxidizing agent. Vacuum drying was performed at room temperature to obtain a polymer compound containing a carbonyl group in the main chain. In dimethyl sulfoxide -d ₆ of this compound, a ¹ H-NMR spectrum was measured by adding a small amount of trifluoroacetic acid in Figure 1. The content of the carbonyl group determined from FIG. 1 was 61 mol%, and the contents of the vinyl alcohol unit and the vinyl acetate unit were 27.5 mol% and 11.5 mol%, respectively.

The IR spectrum of this film is shown in FIG. 2, and it can be seen that the absorption intensity of carbonyl groups at 1600, 1650 and 1735 cm ^-1 is clearly increased.

Example 2 10 parts of polyvinyl alcohol having a saponification degree of 88.5 mol% and an average polymerization degree of 1750 were dissolved by heating in 490 parts of water, and after cooling, 22 parts of sodium carbonate and 2,2,6,6-tetramethyl-1-oxopiperidinium were added. Add 35 parts of ammonium chloride at room temperature in a nitrogen atmosphere
The reaction was performed for 24 hours. This was purified by reprecipitation and drying in the same manner as in Example 1 to obtain a polymer compound containing a carbonyl group in the main chain. The content of carbonyl groups determined by ¹ H-NMR was 49 mol%, and the contents of vinyl alcohol unit and vinyl acetate unit were 39.5 mol% and 11.5 mol%, respectively.

Examples 3 to 8 Polyvinyl alcohol containing a carbonyl group in the main chain was synthesized in the same manner as in Example 1 except that the type and amount of PVA used and the types and amounts of oxidizing agents and additives were changed. The results are shown in Table 1 together with the analysis results.

F. Effects of the Invention The polymer compound obtained by the present invention has an extremely large number of carbonyl groups in the main chain, and the carbonyl groups are located at the 1-position and the 3-position, and are in a cooperative relationship. Therefore, it is a polymer compound having extremely high reactivity. For example, it is well known that 1,3-dicarbonyl compounds have a very high chelating ability, but the polymer compound of the present invention has an extremely large number of 1,3-dicarbonyl groups in the main chain. Its chelating ability is enormous.
In addition, since the main chain contains a large number of carbonyl groups, the molecule is easily cleaved by light and easily degraded by a microorganism as a photodegradable polymer, so that it is extremely useful as a biodegradable polymer. Further, since a crosslinking reaction can be easily caused by utilizing the reactivity of the carbonyl group, the polymer compound is highly useful industrially.

[Brief description of the drawings]

FIG. 1 shows a ¹ H-NMR spectrum of the polymer compound of Example 1. FIG. 2 shows an IR spectrum of the polymer compound of Example 1.

Claims (3)

(57) [Claims] (1) a content of the structural unit represented by the formula (I) of 45 to
85 mol%, content of the structural unit represented by the formula (II) 1 to 5
4.99 mol% and a content of the structural unit represented by the formula (III) of 0.01 to 54 mol%,
A polymer compound having an intrinsic viscosity of 0.25 dl / g or more measured at ° C. (However, R ₁ represents hydrogen or an alkyl group having 1 to 10 carbon atoms) 2. The polymer compound according to claim ₁ , wherein R ₁ in the structural unit represented by the formula (III) is a methyl group. 3. Polyvinyl alcohol having a degree of saponification of not less than 20 mol% is added to a solution in the presence of a perchlorate or a carbonate.
Oxidation using an α'-tetraalkyloxoaminium salt, characterized by the following formulas (I), (II) and (II)
A method for producing a polymer compound comprising the structural unit represented by I). (Formula (I), Formula (II) and Formula (III) are defined in claim 1)
Has the same meaning as in )