WO2020235442A1 - Graft copolymer and method for producing same, and precursor for graft copolymer - Google Patents

Abstract

Provided are: a graft copolymer in which a backbone polymer is an aliphatic polycarbonate and a branch polymer is a polymer of a radical-copolymerizable monomer; a method for producing the graft copolymer; and a precursor for a graft copolymer.　The graft copolymer of the present invention is a graft copolymer having a backbone polymer and a branch polymer bonded to the backbone polymer, wherein the backbone polymer is an aliphatic polycarbonate and the branch polymer is a polymer of a radical-polymerizable monomer. The precursor of the present invention is a precursor for a graft copolymer, wherein a backbone polymer is an aliphatic polycarbonate and the aliphatic polycarbonate has a structural unit containing a functional group having a controlled radical polymerization initiation ability.

Description

Graft copolymer and its production method, and precursor of graft copolymer

The present invention relates to a graft copolymer, a method for producing the same, and a precursor of the graft copolymer.

A graft copolymer is a polymer compound formed by chemically bonding different types of branch polymers to a stem polymer, and has various functions derived from its special structure together with a block copolymer, and thus has various uses. It is being actively studied for use in. In particular, by combining polymers having different properties, it is possible to achieve both high functionality while achieving both properties of both polymers.

For example, Patent Document 1 discloses a binder resin obtained by grafting a (meth) acrylic acid ester polymer onto a cellulosic resin, and exhibits physical properties such as rheological properties, adhesiveness, and sheet strength of the cellulose resin, and the acrylic resin. It is possible to have both easy thermal decomposition properties. Patent Document 2 shows a thermoplastic resin obtained by grafting a vinyl polymer onto a polyester resin, and the polyester resin using this resin as a modifier has heat resistance, molding processability, impact resistance, and adhesion. It is disclosed that the sex is improved.

In recent years, research on aliphatic polycarbonate has been actively conducted, and it is being considered to impart functions by various methods. One of the methods is a method of forming a graft copolymer with another polymer. For example, Non-Patent Document 1 discloses a graft copolymer in which the stem polymer is a carbon dioxide / propylene oxide copolymer and the branch polymer is polylactic acid. Patent Document 3 discloses a graft copolymer in which the stem polymer is an acrylic polymer and the branch polymer is a carbon dioxide / propylene oxide copolymer.

Japanese Unexamined Patent Publication No. 2005-1911 JP-A-2002-226527 Special Table 2013-523988

However, in the studies so far, there have been no synthetic examples of graft copolymers in which the stem polymer is an aliphatic polycarbonate and the branch polymer is a polymer of a radically polymerizable monomer.

When the present inventors attempted graft polymerization from an aliphatic polycarbonate having a radically polymerizable group such as a methacrylic group in the side chain, side reactions such as a homopolymerization reaction of a radically polymerizable monomer or a self-crosslinking reaction were ignored. It occurred at a rate that could not be achieved, and it was found that it was difficult to produce a high-purity graft polymer. As described above, in the graft copolymer based on the aliphatic polycarbonate, it is difficult to use the stem polymer as the aliphatic polycarbonate and the branch polymer as the polymer of the radically polymerizable monomer, and the graft copolymer using the aliphatic polycarbonate is used. There were restrictions on the polymer design in the production of. Moreover, even if such a copolymer is produced, it is difficult to obtain it with high purity.

The present invention has been made in view of the above, and the graft copolymer in which the stem polymer is an aliphatic polycarbonate and the branch polymer is a polymer of a radically polymerizable monomer, a method for producing the same, and a graft copolymer. It is intended to provide a precursor.

As a result of diligent research to achieve the above object, the present inventors have succeeded in introducing a functional group as an initiator of controlled radical polymerization into a part of the side chain of the aliphatic polycarbonate. We have found that the above object can be achieved, and have completed the present invention.

That is, the present invention includes, for example, the subjects described in the following sections.
Item 1
A graft copolymer having a stem polymer and a branch polymer bonded to the stem polymer, wherein the stem polymer is an aliphatic polycarbonate.
A graft copolymer in which the branch polymer is a polymer of a radically polymerizable monomer.
Item 2
Item 2. The graft copolymer according to Item 1, wherein the aliphatic polycarbonate is a copolymer of carbon dioxide and epoxide.
Item 3
Item 2. The graft copolymer according to Item 1 or 2, wherein the radically polymerizable monomer is at least one selected from the group consisting of a styrene-based monomer, an unsaturated ester-based monomer, and an unsaturated amide-based monomer.
Item 4
Item 2. The item according to any one of Items 1 to 3, wherein the value of the ratio DP2 / DP1 of the number average degree of polymerization DP1 of the stem polymer to the number average degree of polymerization DP2 of the branch polymer is 0.1 or more and 10 or less. Graft copolymer.
Item 5
A precursor of a graft copolymer,
The stem polymer is aliphatic polycarbonate,
The aliphatic polycarbonate is a precursor having a structural unit containing a functional group having a controlled radical polymerization initiation ability.
Item 6
Item 5. The precursor according to Item 5, wherein the aliphatic polycarbonate is a copolymer of carbon dioxide and epoxide.
Item 7
Item 5. The precursor according to Item 5 or 6, wherein the structural unit containing a functional group having a controlled radical polymerization initiation ability is contained in 1 mol% or more and 20 mol% or less in all the structural units of the aliphatic polycarbonate.
Item 8
Item 6. The precursor according to any one of Items 5 to 7, wherein the controlled radical polymerization is atom transfer radical polymerization, reversible addition cleavage chain transfer polymerization or nitroxide-mediated radical polymerization.
Item 9
A method for producing a graft copolymer, comprising a step of carrying out a polymerization reaction using the precursor according to any one of Items 5 to 8.

The graft copolymer according to the present invention is a novel graft copolymer in which the stem polymer is an aliphatic polycarbonate and the branch polymer is a polymer of a radically polymerizable monomer. Further, the precursor of the graft copolymer according to the present invention is suitable as a raw material for producing the novel graft copolymer, and it is possible to provide the graft copolymer by a simple method.

The ^{1 H-NMR} spectrum of the precursor of the graft copolymer obtained in Example 1a. The ^{1 H-NMR} spectrum of the precursor of the graft copolymer obtained in Example 1d. The ¹ H-NMR spectrum of the graft copolymer obtained in Example 2a. The ¹ H-NMR spectrum of the graft copolymer obtained in Example 2b. The ¹ H-NMR spectrum of the graft copolymer obtained in Example 2d is shown. The ¹ H-NMR spectrum of the graft copolymer obtained in Example 2e.

Hereinafter, embodiments of the present invention will be described in detail. In addition, in this specification, the expressions "contains" and "includes" include the concepts of "contains", "includes", "substantially consists" and "consists of only".

1. 1. Graft Copolymer The graft copolymer of the present invention is a graft copolymer having a stem polymer and a branch polymer bonded to the stem polymer, the stem polymer being an aliphatic polycarbonate, and the branch polymer being a radical. It is a polymer of polymerizable monomers.

The stem polymer is the backbone of the graft copolymer and is composed of aliphatic polycarbonate.

The type of the aliphatic polycarbonate is not particularly limited, and examples thereof include an aliphatic polycarbonate having a structure having a copolymer of carbon dioxide and an epoxide as a skeleton. The structural unit of the aliphatic polycarbonate having such a structure includes, for example, a structural unit containing a carbonate bond in which carbon dioxide and an epoxide are alternately reacted, and an ether bond in which carbon dioxide does not react and the epoxide is continuously reacted. Structural units and can be included. The structural unit of the aliphatic polycarbonate preferably contains 80 mol% or more of structural units containing a carbonate bond, more preferably 90 mol% or more, further preferably 95 mol% or more, and 99 mol% or more. Is particularly preferable.

The branch polymer binds to the stem polymer by a chemical bond (particularly a covalent bond). There is one or more branch polymers per molecule of the graft copolymer, and usually there are a plurality of branch polymers per molecule of the graft copolymer. The branch polymer is formed by a polymer of radically polymerizable monomers. That is, the graft copolymer of the present invention has an aliphatic polycarbonate as a main chain and a polymer of a radically polymerizable monomer as a side chain.

The type of radically polymerizable monomer is not particularly limited, and for example, known radically polymerizable monomers can be widely applied. Specific examples of the radically polymerizable monomer include an olefin-based monomer, a styrene-based monomer, an unsaturated ester-based monomer, an unsaturated alcohol-based monomer, an unsaturated carboxylic acid-based monomer, an unsaturated carboxylate-based monomer, and an unsaturated amide-based monomer. , Vinyl-based monomers and the like.

Examples of the olefin-based monomer include ethylene, propylene, isobutene, isoprene, butadiene, cyclopentadiene, indene, limonene, α-pinene, β-pinene and the like.

Examples of styrene-based monomers include styrene, α-methylstyrene, 4-methoxystyrene, 4-tert-butylstyrene, 4-chlorostyrene, 4-aminostyrene, 4-nitrostyrene, 4-vinylbenzoic acid, and 4-styrenesulfon. Examples thereof include sodium acid acid and divinylbenzene.

As the unsaturated ester-based monomer, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl cyclohexanecarboxylic acid, vinyl monochloroacetate, vinyl benzoate, isopropenyl acetate, allyl acetate, etc. have a polymerizable double bond at the ester moiety. Monomers; esters of polymerizable carboxylic acid compounds such as (meth) acrylic acid esters; and the like. In the present specification, "(meth) acrylic" means "acrylic" or "methacrylic", "(meth) acrylate" means "acrylate" or "methacrylate", and "(meth) allyl" means "(meth) allyl". Means "allyl" or "methacrylic".

Examples of the (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and (meth). ) Isobutyl acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, glycidyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) ) N-octyl acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic Examples thereof include benzyl acid acid and isobornyl (meth) acrylate. One of these may be used alone, or two or more thereof may be used in combination.

Examples of the ester of the polymerizable carboxylic acid compound include methyl crotonate, methyl angelic acid, methyl tiglic acid, methyl oleate, dimethyl maleate, and dimethyl fumarate, in addition to the (meth) acrylic acid ester.

Examples of unsaturated alcohol-based monomers include allyl alcohol, β-metharyl alcohol, crotyl alcohol, 3-buten-1-ol, and oleyl alcohol.

Examples of unsaturated carboxylic acid-based monomers include (meth) acrylic acid, crotonic acid, angelic acid, tiglic acid, oleic acid, maleic acid, maleic anhydride, fumaric acid and the like.

Examples of the unsaturated carboxylate-based monomer include sodium (meth) acrylate, zinc (meth) acrylate, ammonium (meth) acrylate, sodium crotonic acid, sodium oleate, sodium maleate, sodium fumarate, and the like. ..

Examples of unsaturated amide monomers include (meth) acrylamide, N-methyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N, N-dimethylacrylamide, and N, N-isopropyl. Examples include acrylamide.

Other radically polymerizable monomers include vinyl chloride, (meth) acrylonitrile, vinyl sulfonic acid, vinyl phosphonic acid, N-vinylpyrrolidone, 2-vinylpyridine, ethyl vinyl ether, vinyl oxylane, methyl vinyl ketone, vinylene carbonate, and vinyl. Examples thereof include various vinyl-based monomers such as ethylene carbonate.

Only one type of the above radically polymerizable monomers can be used, or two or more types can be used in combination.

The radically polymerizable monomer is preferably one or more selected from the group consisting of a styrene-based monomer, an unsaturated ester-based monomer, an unsaturated carboxylic acid-based monomer, and an unsaturated amide-based monomer. More preferably, it is one or more selected from the group consisting of styrene-based monomers, unsaturated ester-based monomers, and unsaturated amide-based monomers.

Among them, the radically polymerizable monomers are styrene, vinyl acetate, methyl (meth) acrylate, hydroxyethyl (meth) acrylate, and N-isopropyl (meth) from the viewpoint of easily controlling the polymerization reaction of the radically polymerizable monomer. ) It is particularly preferable that one or more selected from the group consisting of acrylamide, glycidyl (meth) acrylate, vinyl alcohol and vinyl butyral. Therefore, examples of the polymer of the radically polymerizable monomer include polystyrene, polyvinyl acetate, methyl poly (meth) acrylate, hydroxyethyl poly (meth) acrylate, poly N-isopropylacrylamide, polyvinyl alcohol, polyvinyl butyral and the like. Is particularly preferred.

In the graft copolymer of the present invention, the polymer of the radically polymerizable monomer may be a derivative having a structure substituted with another functional group or the like. The functional group is not particularly limited, and for example, the substituent includes an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a halogen atom, a carboxy group, and a carbonyl group. Examples thereof include a group, a sulfonyl group, a sulfone group, a cyano group and the like. These other functional groups can be introduced by further carrying out an addition reaction, a substitution reaction or the like on the polymer of the radically polymerizable monomer.

The polymer of the radically polymerizable monomer may be a homopolymer composed of one kind of monomer unit or a copolymer composed of two or more kinds of monomer units. Further, the polymer of the radically polymerizable monomer is usually linear, but can also have a branch.

The number average degree of polymerization and the number average molecular weight of the graft copolymer of the present invention are not particularly limited, and can be appropriately set according to the type of aliphatic polycarbonate, the type of polymer of radically polymerizable monomer, and the like. For example, the number average molecular weight of the graft copolymer is 1000 to 100,000, preferably 2000 or more, more preferably 3000 or more, and preferably 90000 from the viewpoint of avoiding a decrease in reactivity of the living radical polymerization reaction described later. Below, it is more preferably 80,000 or less, still more preferably 70,000 or less.

In the graft copolymer of the present invention, the value of the ratio DP2 / DP1 between the number average degree of polymerization DP1 of the stem polymer and the number average degree of polymerization DP2 of the branch polymer is not particularly limited, and the performance of the target graft copolymer is not particularly limited. It can be set as appropriate according to.

For example, in the graft copolymer of the present invention, the value of the ratio DP2 / DP1 between the number average degree of polymerization DP1 of the stem polymer and the number average degree of polymerization DP2 of the branch polymer can be 0.1 or more and 10 or less. .. When DP2 / DP1 is in this range, the graft copolymer can preferably exhibit the physical properties of both the stem polymer and the branch polymer. The value of DP2 / DP1 is more preferably 0.2 or more and 5 or less, and further preferably 0.5 or more and 2.5 or less.

In the present specification, the number average degree of polymerization DP2 of the branch polymer indicates the total degree of polymerization of all the branch polymers present per molecule of the graft copolymer.

In the graft copolymer of the present invention, the value of DP2 / DP1 can be measured by nuclear magnetic resonance spectroscopy (NMR analysis). Specifically, the number of moles of the structural unit of the stem polymer and the number of moles of the structural unit of the branch polymer can be obtained by ¹ H-NMR analysis of the graft copolymer, and the value of DP2 / DP1 can be obtained from the ratio of the two. it can.

The graft copolymer in the present invention can be in various forms such as powder, granule, lump, pellet, strand, fibrous, liquid, dispersion, solution, and molded product.

The graft copolymer is different from the conventional graft copolymer in which the stem polymer is an aliphatic polycarbonate and the branch polymer is a polymer of a radically polymerizable monomer, so that the stem polymer is an acrylic polymer and the branch polymer is an aliphatic polycarbonate. Has different functions. For example, taking polyacrylic acid as an acrylic polymer as an example, in a conventional graft polymer using an acrylic polymer as a stem polymer, all carboxy groups are used as starting points of graft polymerization, and the obtained graft polymer has a carboxy group. not exist. Therefore, in such a conventional graft copolymer, the property of polyacrylic acid is lost. On the other hand, in the graft polymer using the aliphatic polycarbonate of the present invention as the stem polymer, when the acrylic polymer is polyacrylic acid, a graft having a carboxy group is obtained. Therefore, it becomes a graft polymer having both the properties of polyacrylic acid and the properties of aliphatic polycarbonate.

Therefore, in the graft copolymer of the present invention, the copolymer itself can be applied as a functional resin, or it can be used as an additive in a material or the like that has not been suitable for conventional graft copolymers. It is possible to exert various effects. For example, the graft copolymer of the present invention can be applied to a pyrolytic binder, a dispersant, a compatibilizer, a resin modifier, a substrate surface modifier, an adhesive, a paint, an additive such as an ink, and the like. It is possible.

2. 2. Precursor of Graft Copolymer In the precursor of the graft copolymer of the present invention (hereinafter, simply referred to as "precursor"), the stem polymer is an aliphatic polycarbonate, and the aliphatic polycarbonate starts controlled radical polymerization. It has a structural unit containing a functional group having a function. Hereinafter, the aliphatic polycarbonate in the precursor is referred to as "aliphatic polycarbonate P", and the structural unit containing a functional group having a controlled radical polymerization initiation ability is referred to as "structural unit I".

The aliphatic polycarbonate P is not particularly limited as long as it has the structural unit I, and for example, an aliphatic polycarbonate obtained by copolymerizing carbon dioxide and an epoxide is preferable.

For example, as the structural unit I of the aliphatic polycarbonate P, a structural unit represented by the following general formula (1) can be mentioned.

Here, in the formula (1), R ¹ , R ² and R ³ are the same or different, and are substituted with a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted with a substituent, or a substituent. Indicates an aryl group having 6 to 20 carbon atoms which may be used. Two of R ¹ to R ³ may be bonded to each other to form a substituted or unsaturated saturated or unsaturated aliphatic ring having 3 to 10 ring members together with the carbon atom to which they are bonded. In formula (1), A represents a functional group having a controlled radical polymerization initiation ability. Hereinafter, the functional group A having the ability to initiate controlled radical polymerization is simply abbreviated as "functional group A".

The controlled radical polymerization means, for example, various living radical polymerizations, and specific examples thereof include atom transfer radical polymerization, reversible addition cleavage chain transfer polymerization, and nitroxide-mediated radical polymerization.

In equation (1), R ¹ , R ² and R ³ may all be the same, R ¹ and R ² may be the same and R ³ may be different, R ² and R ³ may be the same and R ¹ may be different. R ¹ , R ² and R ³ may all be different.

In the present specification, the alkyl group having 1 to 10 carbon atoms is a linear or branched alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. .. The number of carbon atoms is preferably 1 to 9, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. Specifically, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group. , N-octyl group, n-nonyl group, n-decyl group and the like.

In the formula (1), the alkyl groups represented by R ¹ , R ² and R ³ may be substituted with one or more substituents. Examples of the substituent in the alkyl group represented by R ¹ , R ² and R ³ include an alkoxy group, an acyloxy group, an alkoxycarbonyl group, an aryl group and a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom). And so on. Examples of the alkoxy group here include a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group and the like. Examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, a benzoyloxy group and the like. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a tert-butoxycarbonyl group. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a naphthyl group and the like.

In the formula (1), the aryl group having 6 to 20 carbon atoms is an aryl group having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. It is a group, preferably 6 to 14. For example, a phenyl group, a naphthyl group, a tetrahydronaphthyl group and the like can be mentioned.

In the formula (1), the aryl group represented by R ¹ , R ² and R ³ may be substituted with one or more substituents. Examples of the substituent in the aryl group include an alkyl group, an aryl group, an alkoxy group, an acyloxy group, an alkoxycarbonyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom). Examples of the alkyl group here include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and the like. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a naphthyl group, an indenyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group and the like. Examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, a benzoyloxy group and the like. Further, examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a tert-butoxycarbonyl group and the like.

In formula (1), examples of the substituted or unsaturated saturated or unsaturated aliphatic ring having 3 to 10 member numbers formed by bonding two of R ¹ , R ² , and R ³ to each other include, for example. , A 3- to 8-membered aliphatic ring which may be substituted with a substituent. More specific examples of the aliphatic ring include a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a cycloheptane ring and the like. When the aliphatic ring is substituted with a substituent, examples of the substituent include an alkyl group, an aryl group, an alkoxy group, an acyloxy group, a silyl group, a sulfanyl group, a cyano group, a nitro group and a sulfo group. Examples thereof include a formyl group and a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom). In addition, the aliphatic ring may be substituted with one or more substituents. Examples of the alkyl group here include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and the like. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a naphthyl group, an indenyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group and the like. Examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, a benzoyloxy group and the like. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a tert-butoxycarbonyl group.

Although not particularly limited, in the formula (1), R ¹ , R ² and R ³ are preferably the same or different, and are preferably hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. Of these, R ¹ , R ² and R ³ are preferably hydrogen atoms.

In the formula (1), the type of the functional group A is not particularly limited as long as it is a functional group that functions as a controlled radical polymerization initiator. For example, as the functional group A, a halogen-containing group, a dithioester group, a dithiocarbonate group, a dithiocarbamate group, a trithiocarbonate group and the like are preferably mentioned. More specifically, for example, the following general formula (2):

(In formula (2), R ⁴ and R ⁵ are the same or different and represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and X is a chlorine atom, a bromine atom or iodine. Indicates an atom.)
A group containing a structure represented by the following general formula (3):

(In the formula, R ⁶ represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or an ester group having 1 to 15 carbon atoms, and Y represents an alkyl group having 1 to 10 carbon atoms and a carbon number of carbon atoms. It represents an aryl group of 6 to 20, an alkoxy group having 1 to 10 carbon atoms, an alkylamino group having 1 to 10 carbon atoms, or a thioalkoxy group having 1 to 10 carbon atoms.
A group containing a structure represented by, or the following general formula (4);

(In the formula, R ⁷ represents an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or an ester group having 1 to 15 carbon atoms, and R ⁸ and R ⁹ are the same or different hydrogen atoms. , An alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ⁸ and R ⁹ may be bonded to each other together with the nitrogen atom to which they are bonded and substituted with a substituent. An aliphatic nitrogen heterocycle having 4 to 10 ring members may be formed.)
A group containing a structure represented by
Can be mentioned.

In the formula (2), the alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 20 carbon atoms are the same as the alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 20 carbon atoms in the formula (1), respectively. The types of can be exemplified.

In the formulas (3) and (4), the alkylene group having 1 to 10 carbon atoms is preferably, for example, methylene, ethylene, propylene or the like.

In the formulas (3) and (4), the arylene group having 6 to 20 carbon atoms is preferably phenylene or the like.

In the formulas (3) and (4), the ester group having 1 to 15 carbon atoms has 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or Fifteen linear or branched ester groups. The number of carbon atoms is preferably 2 to 13, more preferably 2 to 11, and even more preferably 2 to 10. As the ester group, _{specifically, -OCO -, - OCOCH 2 -} , - OCOCH 2 CH 2 -, - OCOC 6 H 4 -, - OCOCH 2 C 6 H 4 -, - OCOCH 2 C 6 H 4 CH _2- , -OCOCH ₂ C ₆ H ₄ CH (CH ₃ )-, -CH ₂ COOCH _2- , -CH ₂ OCOCH _2-, and the like can be preferably exemplified.

Incidentally, _-C 6 _{H 4} - is represented by the following formula (a)

The group represented by the following formula (a1) to (a3) can be used in more detail, and the group represented by the formula (a1) is preferable.

In the formula (3), the alkoxy group having 1 to 10 carbon atoms is a linear or branched alkoxy group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. .. The number of carbon atoms is preferably 1 to 9, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. Specific examples of the alkoxy group include -OCH ₃ , -OCH ₂ CH ₃ , -OCH ₂ CH ₂ CH ₃ , -OCH (CH ₃ ) CH ₃ , -OCH ₂ CH ₂ CH ₂ CH ₃ , and -OCH. ₂ CH (CH ₃ ) CH ₃ , -OCH (CH ₃ ) CH ₂ CH ₃ , -OCH ₂ CH ₂ CH ₂ CH ₂ CH ₃ , -OCH ₂ CH ₂ CH (CH ₃ ) CH ₃ , -OCH ₂ CH ( CH ₃ ) CH ₂ CH ₃ , -OCH (CH ₃ ) CH ₂ CH ₂ CH _{3 and the} like can be preferably exemplified.

In the formula (3), the alkylamino group having 1 to 10 carbon atoms is a linear or branched alkylamino group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Is. The number of carbon atoms is preferably 1 to 9, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. Specific examples of the alkylamino group include -NHCH ₃ , -NHCH ₂ CH ₃ , -NHCH ₂ CH ₂ CH ₃ , -NHCH (CH ₃ ) ₂ , -NHCH ₂ CH ₂ CH ₂ CH ₃ , and -NHCH. ₂ CH (CH ₃ ) CH ₃ , -NHCH (CH ₃ ) CH ₂ CH ₃ , -NHCH ₂ CH ₂ CH ₂ CH ₂ CH ₃ , -NHCH ₂ CH ₂ CH (CH ₃ ) ₂ , -NHCH ₂ CH (CH) ₃ ) CH ₂ CH ₃ , -NHCH (CH ₃ ) CH ₂ CH ₂ CH ₃ , -N (CH ₃ ) ₂ , -N (CH ₂ CH ₃ ) _{2, and the} like can be preferably exemplified.

In the formula (3), the thioalkoxy group having 1 to 10 carbon atoms is a linear or branched thioalkoxy group having 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Is. The number of carbon atoms is preferably 1 to 9, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. Specific examples of the thioalkoxy group include -SCH ₃ , -SCH ₂ CH ₃ , -SCH ₂ CH ₂ CH ₃ , -SCH ₂ CH ₂ CH ₂ CH ₃ , -SCH ₂ CH (CH ₃ ) ₂ , -SCH (CH ₃ ) CH ₂ CH ₃ , -SCH ₂ CH ₂ CH ₂ CH ₂ CH ₃ , -SCH ₂ CH ₂ CH (CH ₃ ) ₂ , -SCH ₂ CH (CH ₃ ) CH ₂ CH ₃ , -SCH (CH ₃ ) CH ₂ CH ₂ CH _{3 and the} like can be preferably exemplified.

In formula (4), R ⁸ and R ⁹ are attached to each other together with the nitrogen atom to which they are attached, and are aliphatic groups having 4 to 10 ring members (4, 5, 6, 7, 8, 9, or 10). A nitrogen heterocycle may be formed. The nitrogen atom in the aliphatic nitrogen heterocycle is derived from the nitrogen atom to which R ⁸ and R ⁹ are bonded. In addition, the aliphatic nitrogen heterocycle may be saturated or unsaturated. Moreover, the aliphatic nitrogen heterocycle may be substituted with a substituent. Examples of the substituent here include an alkyl group, an aryl group, an alkoxy group, an acyloxy group, a silyl group, a sulfanyl group, a cyano group, a nitro group, a sulfo group, a formyl group and the like. Further, the aliphatic nitrogen heterocycle may be substituted with one or more substituents. Examples of the alkyl group here include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and the like. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a naphthyl group, an indenyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group and the like. Examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, a benzoyloxy group and the like. Examples of the silyl group include a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a trimethoxysilyl group, a dimethoxymethylsilyl group, a methoxydimethylsilyl group and the like.

In the precursor, the aliphatic polycarbonate P can have other structural units other than the structural unit I. As a specific example of another structural unit, the following general formula (5)

(In formula (5), R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are the same or different alkyl groups having 1 to 10 carbon atoms which may be substituted with hydrogen atoms or substituents, or substituents. It represents an aryl group having 6 to 20 carbon atoms which may be substituted, and two of R ¹⁰ to R ¹³ are bonded to each other, and together with the carbon atom to which they are bonded, the substituted or unsaturated saturated or unsaturated It may form an aliphatic ring having 3 to 10 ring members.)
The structural unit represented by is given.

In formula (5), R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are the same or different. That is, R ¹⁰ , R ¹¹ , R ¹² and R ¹³ may all be the same, R ¹⁰ , R ¹¹ , R ¹² may be the same and R ¹³ may be different, and R ¹⁰ , R ¹² , and R ¹³ may be the same. R ¹¹ may be different, and R ¹⁰ , R ¹¹ , R ¹² and R ¹³ may all be different.

In the formula (5), the alkyl group having 1 to 10 carbon atoms which may be substituted with the substituent is the same as the alkyl group having 1 to 10 carbon atoms which may be substituted with the substituent of the formula (1). The types of can be exemplified.

In the formula (5), the aryl group having 6 to 20 carbon atoms which may be substituted with the substituent is the same as the aryl group having 6 to 20 carbon atoms which may be substituted with the substituent of the formula (1). The types of can be exemplified.

In formula (5), as an aliphatic ring having a saturated or unsaturated ring member number of 3 to 10 which is substituted or unsaturated and is formed by bonding two of R ¹⁰ , R ¹¹ , R ¹² and R ¹³ to each other. For example, a 3- to 8-membered aliphatic ring which may be substituted with a substituent may be mentioned. More specific examples of the aliphatic ring include a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a cycloheptane ring and the like. When the aliphatic ring is substituted with a substituent, examples of the substituent include an alkyl group, an aryl group, an alkoxy group, an acyloxy group, a silyl group, a sulfanyl group, a cyano group, a nitro group and a sulfo group. Examples thereof include a formyl group and a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom). In addition, the aliphatic ring may be substituted with one or more substituents. Examples of the alkyl group here include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group and the like. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a naphthyl group, an indenyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group and the like. Examples of the acyloxy group include an acetoxy group, a propionyloxy group, a butyryloxy group, an isobutyryloxy group, a pivaloyloxy group, a benzoyloxy group and the like. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a tert-butoxycarbonyl group.

Among them, R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are preferably the same or different, and are preferably hydrogen atoms or alkyl groups having 1 to 4 carbon atoms. In particular, it is preferable that R ¹⁰ , R ¹¹ and R ¹² are hydrogen atoms, and R ¹³ is an alkyl group having 1 to 4 carbon atoms. Further, among them, it is more preferable that R ¹³ is a methyl group.

In the aliphatic polycarbonate P, the content ratio of the structural unit I is not particularly limited. For example, the structural unit I is preferably contained in an amount of 1 mol% or more and 20 mol% or less in all the structural units of the aliphatic polycarbonate P. In this case, in the graft copolymer synthesized using the precursor, both the physical properties of the stem polymer and the branch polymer can be preferably exhibited. As the structural unit contained in the aliphatic polycarbonate P, for example, other structural units described above can be mentioned as the structural unit other than the structural unit I, and the structural unit represented by the formula (5) is preferable. Can be done. The structural unit I is more preferably contained in an amount of 2 mol% or more and 12 mol% or less, more preferably 2.5 mol% or more and 8 mol% or less, in the total structural unit of the aliphatic polycarbonate P, 3 mol. It is particularly preferable that it is contained in an amount of% or more and 8 mol% or less. In these cases, the balance can be, for example, a structural unit represented by the formula (5).

The number average molecular weight of the aliphatic polycarbonate P is not particularly limited, and is, for example, 1000 to 100,000. In this case, the handleability of the graft copolymer obtained by the living radical polymerization of the precursor described later is excellent. The number average molecular weight of the aliphatic polycarbonate P is preferably 2000 or more, more preferably 3000 or more, and preferably 50,000 or less, more preferably 30,000 or less, from the viewpoint of avoiding a decrease in the reactivity of the living radical polymerization reaction described later. More preferably, it is 25,000 or less.

(Precursor manufacturing method)
The method for producing the precursor is not particularly limited, and for example, the polymerization method used in the production of known aliphatic polycarbonates can be selected. For example, the aliphatic polycarbonate P can be produced by a production method including a step of copolymerizing carbon dioxide and epoxide. Hereinafter, this manufacturing method is abbreviated as "manufacturing method P".

The aliphatic polycarbonate P obtained by the production method P contains a structural unit containing a carbonate bond in which carbon dioxide and an epoxide are alternately reacted, and a structural unit containing an ether bond in which carbon dioxide does not react and the epoxide is continuously reacted. It can be. The structural unit of the aliphatic polycarbonate P preferably contains 80 mol% or more of structural units containing a carbonate bond, more preferably 90 mol% or more, further preferably 95 mol% or more, and 99 mol% or more. Is particularly preferred.

In the production method P, an epoxide having a functional group having at least a controlled radical polymerization initiation ability and an epoxide capable of forming the structural unit I represented by the formula (1) by reacting with carbon dioxide is used. Can be done. As a result, the aliphatic polycarbonate P obtained by the production method P can have the structural unit I in its structural unit.

Alternatively, in the production method P, an aliphatic polycarbonate having a structural unit I is formed by forming an aliphatic polycarbonate by a polymerization reaction of carbon dioxide and an epoxide, and then introducing a functional group A having a controlled radical polymerization initiation ability into a side chain. Polycarbonate P can be obtained.

Among the aliphatic polycarbonates of the present invention, examples of the epoxide used for forming the structural unit represented by the formula (1) include glycidyl chloroacetate, glycidyl bromoacetate, glycidyl 2-chloropropionate, and 2-bromo. Glycidyl propionate, glycidyl 2-chloroisobutyrate, glycidyl 2-bromoisobutyrate, 1-chlorophenyl glycidyl acetate, 1-bromophenyl glycidyl acetate, 2- [4- (chloromethyl) phenyl] oxylane, 2- [4- (bromomethyl) Phenyl] oxylan, 2- [4- (chloromethyl) phenoxy] methyloxylan, 2- [4- (bromomethyl) phenoxy] methyloxylan, 2- [4- (1-chloroethyl) phenyl] oxylan, 2- [4- (1-Bromoethyl) phenyl] oxylane, 2- [4- (1-chloroethyl) phenoxy] methyloxylan, 2- [4- (1-bromoethyl) phenoxy] methyloxylan, 2- (thiobenzoylthio) glycidyl acetate, dithio Glycidyl benzoate, 4-cyano-4-[[[2-phenylethylthio] thioxomethyl] glycidyl thiopentate, 2-[[(dodecylthio) thioxomethyl] thio] glycidyl 2-methylbutyrate, N, N-dimethyldithiocarbamic acid Glycidyl, N, N-didodecyl dithiocarbamate glycidyl, N-methyl-N- (phenylmethyl) glycidyl dithiocarbamate, glycidyl methylxanthogenate, glycidyl ethylxanthogenate, glycidyl butylxanthogenate, 2,2,6,6-tetra Methyl-1- [1- [4- (2-oxylanylmethoxy) phenyl] ethoxy] -4-methoxypiperidin, 2,2,6,6-tetramethyl-1- [1- [4- (2- (2-) Oxylanylmethoxy) phenyl] ethoxy] -4-propoxypiperidine, 2,2,6,6-tetramethyl-1- [1- [4- (2-oxylanylmethoxy) phenyl] ethoxy] piperidine, [( 2,2,6,6-tetramethyl-1-piperidinyl) oxy] glycidyl acetate, [(2,2,6,6-tetramethyl-1-piperidinyl) oxy] glycidyl propionate and the like can be mentioned.
Of these, glycidyl 2-chloropropionate, glycidyl 2-bromopropionate, and glycidyl 2-bromoisobutyrate are preferable from the viewpoint of having high reactivity.

The epoxide used in the production method P is a combination of the epoxide used for forming the structural unit represented by the formula (1) and the epoxide used for forming the structural unit represented by the formula (5). can do. Examples of the epoxide used to form the structural unit represented by the formula (5) include ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, isobutylene oxide, 1-pentene oxide, 2-pentene oxide, and 1 -Hexene oxide, 1-octene oxide, 1-dodecene oxide, cyclopentene oxide, cyclohexene oxide, styrene oxide, vinylcyclohexane oxide, 3-phenylpropylene oxide, 3-naphthylpropylene oxide, 3-phenoxypropylene oxide, 3-naphthoxy Examples include propylene oxide.
Among them, ethylene oxide, propylene oxide, 1-butene oxide and cyclohexene oxide are preferable, ethylene oxide, propylene oxide and 1-butene oxide are more preferable, and propylene oxide is particularly preferable, from the viewpoint of having high reactivity.

In the epoxide used in the production method P, the content of the epoxide used for forming the structural unit represented by the formula (1) and the epoxide used for forming the structural unit represented by the formula (5). Is not particularly limited. For example, the ratio of both can be adjusted so that the content ratio of the constituent unit I is within the range described later.

In the production method P, the polymerization reaction of carbon dioxide and epoxide is preferably carried out in the presence of a metal catalyst. As the metal catalyst in this case, for example, a known metal catalyst used in the polymerization reaction of carbon dioxide and epoxide can be widely used.

Specific examples of the metal catalyst include zinc-based catalysts, magnesium-based catalysts, aluminum-based catalysts, chromium-based catalysts, cobalt-based catalysts, nickel-based catalysts, and the like. Among these, zinc-based catalysts and cobalt-based catalysts are preferable because they have high polymerization activity in the polymerization reaction between epoxides and carbon dioxide, and cobalt-based catalysts are more preferable from the viewpoint of easy control of molecular weight.

Examples of the zinc-based catalyst include organic zinc catalysts such as zinc acetate, diethyl zinc, and dibutyl zinc; primary amines, divalent phenols, aromatic dicarboxylic acids, aromatic hydroxy acids, aliphatic dicarboxylic acids, and aliphatic monocarboxylic acids. Examples thereof include an organozinc catalyst obtained by reacting a compound such as the above with a zinc compound. Among these organozinc catalysts, an organozinc catalyst obtained by reacting a zinc compound with an aliphatic dicarboxylic acid and an aliphatic monocarboxylic acid is preferable because it has a higher polymerization activity, and zinc oxide, glutaric acid, and acetic acid are preferable. An organozinc catalyst obtained by reacting with is more preferable.

As the cobalt-based catalyst, for example, the following general formula (6):

(In the formula, are R ¹⁴ and R ¹⁵ identical or different, hydrogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aromatic groups, or substituted or unsubstituted aromatic heterocyclic groups? , Or two R ^14s or two R ^15s may combine with each other to form a substituted or unsubstituted saturated or unsaturated aliphatic ring; R ¹⁶ , R ¹⁷ and R ¹⁸ may be the same or Differently, hydrogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted aromatic groups, substituted or unsubstituted aromatic heterocyclic groups, substituted or unsubstituted alkoxy groups, R ¹⁷ on a substituted or unsubstituted acyl group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aromatic oxycarbonyl group, a substituted or unsubstituted aralkyloxycarbonyl group, or adjacent carbon atoms. and ^{R 18} and are may be bonded to form a substituted or unsubstituted aliphatic ring or a substituted or unsubstituted aromatic rings each other, Z ^{is, F -, Cl -, Br} -, I -, N 3 - _{^{, CF 3 SO 3 -, p}} -CH 3 C 6 H 4 SO 3 -, BF 4 -, NO 2 -, NO 3 -, OH -, PF 6 -, BPh 4 -, SbF 6 -, ClO 4 -, An anionic ligand selected from the group consisting of aliphatic carboxylates, aromatic carboxylates, alkoxides, and aromatic oxides)
A cobalt complex represented by is used.

Among the cobalt complexes represented by the formula (6), the following general formula (7):

(In the formula, are R ¹⁴ and R ¹⁵ identical or different, hydrogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted aromatic groups, or substituted or unsubstituted aromatic heterocyclic groups? , Or two R ^13s or two R ^15s may combine with each other to form a substituted or unsubstituted saturated or unsaturated aliphatic ring; each of the plurality of R ^19s is independently hydrogenated. An atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aromatic group, or a halogen atom, where Z is F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ ,. _{^{N 3 -, CF 3 SO 3}} -, p-CH 3 C 6 H 4 SO 3 -, BF 4 -, NO 2 -, NO 3 -, OH -, PF 6 -, BPh 4 -, SbF 6 -, ClO ₄ ^-, aliphatic carboxylate, aromatic carboxylate, alkoxide, and an anionic ligand selected from the group consisting of aromatic oxide)
The cobalt complex represented by is preferable.

Among the cobalt complexes represented by the formula (7), the cobalt complexes represented by the following formulas (7-1) to (7-5) are preferable.

In the production method P, the amount of the metal catalyst used in the polymerization reaction is preferably 0.001 part by mass or more, more preferably 0.01 with respect to 100 parts by mass of the epoxide, from the viewpoint of promoting the progress of the polymerization reaction. It is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less from the viewpoint of obtaining an effect commensurate with the amount used.

In the production method P, the metal catalyst used in the polymerization reaction can be produced, for example, by a known method.

The polymerization reaction may be carried out in the presence of a co-catalyst in addition to the metal catalyst, if necessary. As co-catalysts, bis (triphenylphosphoranylidene) ammonium chloride (PPNCl), piperidine, bis (triphenylphosphoranylidene) ammonium fluoride (PPNF), bis (triphenylphosphoranilidine) ammonium pentafluorobenzoate (PPNOBzF) ₅ ), Tetra-n-butylammonium chloride (nBu ₄ NCl), tetra-n-butylammonium bromide (nBu ₄ NBr), tetra-n-butylammonium iodide (nBu ₄ NI), tetra-n-butylammonium acetate. (NBu ₄ NOAc), tetra-n-butylammonium nitrate (nBu ₄ NO ₃ ), triethylphosphine (Et ₃ P), tri-n-butylphosphine (nBu ₃ P), triphenylphosphine (Ph ₃ P), Examples thereof include pyridine, 4-methylpyridine, 4-formylpyridine, 4- (N, N-dimethylamino) pyridine, N-methylimidazole, N-ethylimidazole and the like. Among these, PPNCl, PPNF, PPNOBzF ₅ and nBu ₄ NCl are preferable, and PPNCl is more preferable from the viewpoint of having high reaction activity.

When the co-catalyst is used in the production method P, the amount of the co-catalyst used is preferably 0.1 to 10 mol, more preferably 0.3 to 5 mol, still more preferably 0. It is 5 to 1.5 mol. If it is less than 0.1 mol or more than 10 mol, a side reaction is likely to occur in the polymerization reaction.

In the production method P, a solvent can be used in the polymerization reaction if necessary. The solvent is not particularly limited, and various organic solvents can be used. Examples of the organic solvent include aliphatic hydrocarbon solvents such as pentane, hexane, octane and cyclohexane; aromatic hydrocarbon solvents such as benzene, toluene and xylene; methylene chloride, chloroform, carbon tetrachloride, 1,1- Halogenated hydrocarbon solvents such as dichloroethane, 1,2-dichloroethane, chlorbenzene and bromobenzene; ether solvents such as dimethoxyethane, tetrahydrofuran, 2-methyl tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane and anisole. Ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate; amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide; dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, propylene carbonate and the like Examples thereof include carbonate solvents.

When a solvent is used in the production method P, the amount of the solvent used is preferably 100 to 10000 parts by mass with respect to 100 parts by mass of epoxide, for example, from the viewpoint of smoothly proceeding the polymerization reaction.

In the production method P, the method of polymerizing the epoxide and carbon dioxide is not particularly limited. For example, an autoclave may be charged with an epoxide, a metal catalyst, and if necessary, a co-catalyst, a reaction solvent, or the like, mixed, and then carbon dioxide is press-fitted to cause a reaction.

In the production method P, the amount of carbon dioxide used in the polymerization reaction is preferably 1 to 10 mol, more preferably 1 to 5 mol, and further preferably 1 to 3 mol with respect to 1 mol of the epoxide.

The working pressure of carbon dioxide used in the polymerization reaction is not particularly limited, but is preferably 0.1 MPa or more, more preferably 0.2 MPa or more, still more preferably 0.5 MPa or more, from the viewpoint of smooth progress of the reaction. From the viewpoint of obtaining an effect commensurate with the working pressure, it is preferably 20 MPa or less, more preferably 10 MPa or less, still more preferably 5 MPa or less.

The polymerization reaction temperature in the polymerization reaction is not particularly limited. From the viewpoint of shortening the reaction time, it is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, still more preferably 20 ° C. or higher, and from the viewpoint of suppressing side reactions and improving the yield, preferably 100 ° C. or lower. It is preferably 90 ° C. or lower, more preferably 80 ° C. or lower. The polymerization reaction time cannot be unconditionally determined because it varies depending on the polymerization reaction conditions, but it is preferably about 1 to 40 hours.

3. 3. Method for Producing Graft Copolymer The method for producing the graft copolymer of the present invention is not particularly limited. For example, a graft copolymer can be produced by a step of carrying out a polymerization reaction using the precursor as a raw material. In particular, since the precursor is an aliphatic polycarbonate P having a structural unit I and has a functional group A having a controlled radical polymerization initiation ability in its side chain, the precursor is subjected to controlled radical polymerization. Therefore, the graft copolymer of the present invention can be easily produced.

The controlled radical polymerization method that can be used in the method for producing a graft copolymer of the present invention can be appropriately selected depending on the type of functional group having the ability to initiate controlled radical polymerization. For example, when the functional group having a controlled radical polymerization initiation ability is the above-mentioned halogen-containing group, atom transfer radical polymerization can be used. When the functional group having a controlled radical polymerization initiation ability is the above-mentioned dithioester group, dithiocarbonate group, dithiocarbamate group, or trithiocarbonate group, reversible addition cleavage chain transfer polymerization can be used. When the functional group having a controlled radical polymerization initiation ability is the above-mentioned alkoxyamine group, nitroxide-mediated radical polymerization can be used.

Hereinafter, the method for producing the graft copolymer of the present invention using the precursor as a raw material will be referred to as production method G.

In the production method G, a graft copolymer can be specifically produced by polymerizing a precursor and a radically polymerizable monomer. In this case, the precursor becomes the stem polymer of the graft copolymer, and the radically polymerizable monomer polymerizes to become the branch polymer of the graft copolymer.

In the production method G, a catalyst or an initiator can be used in the polymerization reaction, if necessary.

When atomic transfer radical polymerization is used as a catalyst, for example, a metal complex formed from a transition metal compound such as Group 7, 8, 9, 10, or 11 and an organic ligand; phosphorus, A catalyst consisting of a compound containing at least one central element selected from nitrogen, carbon, oxygen, germanium, tin, and antimony and a halogen atom bonded to the central element; an organic amine compound; and an ion with a halide ion. Examples thereof include a catalyst C; which is a non-metal compound having a bond in which a non-metal atom in the non-metal compound is in a cation state and forms an ionic bond with a halide ion.

Examples of the transition metal compounds such as Group 7, 8, 9, 10, or 11 include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, and oxidation. Bronze, ferrous chloride, ferrous bromide, ferrous iodide, iron dichloride, iron dibromide, iron diiodide, ruthenium dichloride, ruthenium dibromide, ruthenium diiodide, etc. Can be mentioned.

Examples of the organic ligands include 2,2'-bipyridyl, 1,10-phenanthroline, tetramethylethylenediamine, pentamethyldiethylenetriamine, tris (dimethylaminoethyl) amine, tris (2-pyridylmethyl) amine, and triphenyl. Examples thereof include phosphine and tributylphosphine.

The catalyst used as the central element selected from germanium, tin, or antimony is a compound containing at least one central element selected from germanium, tin, or antimony and at least one halogen atom bonded to the central element. Can be mentioned. Specific examples thereof include germanium iodide (II), germanium iodide (IV), tin iodide (II), tin iodide (IV) and the like.

Examples of the catalyst containing nitrogen or phosphorus as a central element include compounds containing at least one central element selected from nitrogen or phosphorus and at least one halogen atom bonded to the central element. Specific examples thereof include phosphorus halide, phosphine halide, nitrogen halide, phosphite halide, amine halide and imide derivative halide.

Examples of the organic amine compound include triethylamine, tributylamine, 1,1,2,2-tetrakis (dimethylamino) ethylene, 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane. , Ethylenediamine, tetramethylethylenediamine, tetramethyldiaminomethane, tris (2-aminoethyl) amine, tris (2-methylaminoethyl) amine and the like.

Examples of the catalyst C include ammonium salts such as tetrabutylammonium iodide, tetrabutylammonium triiodide, and tetrabutylammonium bromodiiodide; 1-methyl-3-methyl-imidazolium iodide, 1-ethyl-3-methyl. Imidazolium salts such as imidazolium bromide; pyridinium salts such as 2-chloro-1-methylpyridinium iodide; phosphonium salts such as methyltributylphosphonium iodide and tetraphenylphosphonium iodide; sulfonium salts such as tributylsulfonium iodide; diphenyl Iodonium salts such as iodonium iodide; and the like.

When reversible addition cleavage chain transfer polymerization is used as an initiator, 2,2'-azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'- Azobis (2-methylbutyronitrile), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-methylpropionic acid) dimethyl, 2,2'-azobis (2-methylpropion) Azobisisobutyate and other azo compounds; peroxides such as benzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, potassium peroxobisulfate; Can be mentioned.

When nitroxide-mediated radical polymerization is used, a graft copolymer can be obtained without using a catalyst and an initiator.

The radically polymerizable monomer used in the production method G is the same as the radically polymerizable monomer described in the section of "1. Graft copolymer".

In the production method G, the amount of the radically polymerizable monomer used is not particularly limited, and can be appropriately set according to the structure of the target graft copolymer. For example, the amount of the radically polymerizable monomer used is 10 to 5000 mol with respect to 1 mol of the functional group having the ability to initiate controlled radical polymerization in the precursor. When the amount used is in this range, both the physical properties of the stem polymer and the physical properties of the branch polymer can be preferably exhibited. The amount of the radically polymerizable monomer used is preferably 50 mol to 1500 mol, more preferably 100 mol to 800 mol, based on 1 mol of the functional group having the ability to initiate controlled radical polymerization in the precursor.

In the production method G, a solvent can be used in the polymerization reaction as needed. Various organic solvents can be used as the solvent, for example, aliphatic hydrocarbon solvents such as pentane, hexane, octane and cyclohexane; aromatic hydrocarbon solvents such as benzene, toluene and xylene; dimethoxyethane, tetrahydrofuran, etc. Ether solvents such as 2-methyl tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, anisole; ester solvents such as ethyl acetate, n-propyl acetate, isopropyl acetate; N, N-dimethylformamide, N, N -Amid solvents such as dimethylacetamide; carbonate solvents such as dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, propylene carbonate and the like can be mentioned. Further, when a radically polymerizable monomer that becomes liquid during the polymerization reaction is used, it is not necessary to use a solvent.

The amount of the solvent used is, for example, 0 mol to 10000 mol, preferably 10 mol to 5000 mol, further preferably 50 mol to 2000 mol, and particularly preferably 100 mol to 1000 mol, based on 1 mol of the precursor. When the amount of the solvent is within this range, the graft polymerization reaction can be carried out at a sufficient reaction rate.

In the production method G, the temperature of the polymerization reaction can be appropriately set according to the type of controlled radical polymerization and the type of radically polymerizable monomer used, for example, 0 ° C. to 200 ° C., preferably 30 ° C. to 150 ° C. , More preferably 50 ° C to 120 ° C.

Even after the polymerization reaction is completed, in the obtained graft copolymer, a structure that serves as an initiator of controlled radical polymerization exists at the end of the branch polymer, so that the same or other monomer and the graft copolymer can be used. Can also be controlled radical polymerization.

Further, by performing post-treatment after the polymerization reaction, the terminal group of the branch polymer can be converted to another group, which further increases the degree of freedom in designing the graft copolymer. The post-treatment can be appropriately selected depending on the type of controlled radical polymerization, for example, decomposition treatment by heating and light irradiation; hydrolysis treatment; hydrogenation decomposition treatment; coupling reaction with free radicals; thiol compound. Reduction treatment; etc.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the aspects of these Examples.

In this example, the number average molecular weight (Mn) of the aliphatic polycarbonate and the block copolymer was measured by the following method.

[Number average molecular weight (Mn)]
A chloroform solution having an aliphatic polycarbonate concentration or a block copolymer concentration of 0.5% by mass was prepared and measured using a high performance liquid chromatograph (HPLC). After the measurement, the number average molecular weight was calculated by comparing the number average molecular weight measured under the same conditions with known polystyrene. The measurement conditions are as follows.
Column: GPC column (trade name of Showa Denko KK, Shodex K-804L)
Column temperature: 40 ° C
Eluate: Chloroform flow rate: 1.0 mL / min

[DP2 / DP1 ratio]
The DP2 / DP1 ratio was measured from the ¹ H-NMR spectrum of the graft copolymer, and specifically, it was measured as follows according to the radically polymerizable monomer species used in the production of the graft copolymer.
-In the case of methyl methacrylate, the integral ratio of the peak of methine hydrogen on the carbon adjacent to the carbonate appearing near 5.0 ppm is A, and the integral ratio of the peak of methyl hydrogen of polymethyl methacrylate appearing around 3.6 ppm is B. , B / 3A was defined as the degree of polymerization ratio DP2 / DP1.
-In the case of glycidyl methacrylate, the integral ratio of the peak of methine hydrogen on the carbon adjacent to the carbonate appearing near 5.0 ppm is A, and the integral ratio of the peak of methine hydrogen of the epoxy group of polyglycidyl methacrylate appearing around 3.2 ppm. Was B, and the value of B / A was the degree of polymerization ratio DP2 / DP1.
-In the case of N-isopropylacrylamide, the integral ratio of the peak of methine hydrogen on the carbon adjacent to the carbonate appearing around 5.0 ppm is A, and the integral ratio of the peak of methyl hydrogen of poly (N-isopropylacrylamide) appearing around 1.1 ppm. The ratio was B, and the value of B / 6A was the degree of polymerization ratio DP2 / DP1.
-In the case of styrene, the integral ratio of the peak of methine hydrogen on the carbon adjacent to the carbonate appearing near 5.0 ppm is A, and the integral ratio of the peak of hydrogen of the phenyl group appearing around 6.3 to 7.2 ppm is B. The value of B / 5A was defined as the degree of polymerization ratio DP2 / DP1.

(Production Example 1: Production of cobalt complex catalyst)
In a 50 mL flask equipped with a stirrer, (R, R) -N, N'-bis (3,5-di-tert-butylsalicylidene) -1,2-cyclohexanediaminocobalt (II) (from Aldrich) (Purchased) 150 mg (0.25 mmol), 53 mg (0.25 mmol) of pentafluorobenzoic acid, and 5 mL of dichloromethane were charged, and the mixture was stirred and reacted for 22 hours while introducing air. The volatile components were evaporated under reduced pressure and then dried under reduced pressure to obtain a cobalt complex (cobalt complex represented by the above formula (7-3)) as a dark green solid (yield 195 mg, yield 96.5%).

(Example: Synthesis of precursor of graft copolymer)
<Example 1a>
Precursors were synthesized according to the reaction scheme shown in the following formula (S1-1). In a 50 mL autoclave, 8.7 mg (0.011 mmol) of the cobalt complex obtained in Production Example 1, 6.2 mg (0.011 mmol) of bis (triphenylphosphoranylidene) ammonium chloride (PPNCl), and 2-bromoisobutyric acid. 80 μL (0.53 mmol) of glycidyl was charged, and the inside of the autoclave was replaced with an argon atmosphere. 1.5 mL (21 mmol) of propylene oxide was charged, filled with carbon dioxide until the pressure in the autoclave reached 1.5 MPa, and then stirred at 25 ° C. for 24 hours. After completion of the reaction, the autoclave was decompressed, the reaction mixture was diluted with methylene chloride, and then 1.0 g of hydrochloric acid acidic methanol was added to stop the reaction. The mixture was concentrated under reduced pressure, and the obtained residue was dissolved by adding 5 mL of chloroform, and this solution was added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was filtered and dried under reduced pressure to obtain 1.77 g of aliphatic polycarbonate (yield 76%). The Mn of the obtained aliphatic polycarbonate was 25,800.

FIG. 1 shows a ¹ H-NMR spectrum of a precursor of the graft copolymer obtained in Example 1a. From this ^{1 1} H-NMR, it was found that the content of the structural unit I represented by the above formula (1) was 2.4 mol% in the total structural units.

<Example 1b>
In a 50 mL autoclave, 17.5 mg (0.021 mmol) of the cobalt complex obtained in Production Example 1, 12.3 mg (0.021 mmol) of bis (triphenylphosphoranylidene) ammonium chloride (PPNCl), 2-bromoisobutyric acid. 0.32 mL (2.1 mmol) of glycidyl was charged, and the inside of the autoclave was replaced with an argon atmosphere. 3.0 mL (42 mmol) of propylene oxide was charged, filled with carbon dioxide until the pressure in the autoclave reached 1.5 MPa, and then stirred at 25 ° C. for 24 hours. After completion of the reaction, the autoclave was decompressed, the reaction mixture was diluted with methylene chloride, and then 1.0 g of hydrochloric acid acidic methanol was added to stop the reaction. The reaction mixture was concentrated under reduced pressure, and 5 mL of chloroform was added to the obtained residue to dissolve it to obtain a solution. This solution was added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was filtered and dried under reduced pressure to obtain 2.83 g of a precursor (yield 57%). The Mn of the obtained precursor was 21,900. From ¹ H-NMR of the obtained precursor, it was found that the content of the structural unit I represented by the above formula (1) was 5.4 mol% in all the structural units.

<Example 1c>
In a 50 mL autoclave, 8.7 mg (0.011 mmol) of the cobalt complex obtained in Production Example 1, 6.2 mg (0.011 mmol) of bis (triphenylphosphoranylidene) ammonium chloride (PPNCl), and 2-bromoisobutyric acid. 0.32 mL (2.1 mmol) of glycidyl was charged, and the inside of the autoclave was replaced with an argon atmosphere. 1.5 mL (21 mmol) of propylene oxide was charged, filled with carbon dioxide until the pressure in the autoclave reached 1.5 MPa, and then stirred at 25 ° C. for 24 hours. After completion of the reaction, the autoclave was decompressed, the reaction mixture was diluted with methylene chloride, and then 1.0 g of hydrochloric acid acidic methanol was added to stop the reaction. The mixture was concentrated under reduced pressure, and the obtained residue was dissolved by adding 5 mL of chloroform, and this solution was added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was filtered and dried under reduced pressure to obtain 1.27 g of aliphatic polycarbonate (yield 45%). The Mn of the obtained precursor was 19100. From ¹ H-NMR of the obtained precursor, it was found that the content of the structural unit I represented by the above formula (1) was 4.8 mol% in all the structural units.

<Example 1d>
Precursors were synthesized according to the reaction scheme shown in the following formula (S1-2). In a 50 mL autoclave, 29.1 mg (0.036 mmol) of the cobalt complex obtained in Production Example 1, 20.5 mg (0.036 mmol) of bis (triphenylphosphoranylidene) ammonium chloride (PPNCl), 2-chloro- 0.49 mL (3.6 mmol) of glycidyl propionate was charged, and the inside of the autoclave was replaced with an argon atmosphere. 5.0 mL (71 mmol) of propylene oxide was charged, filled with carbon dioxide until the pressure in the autoclave reached 1.5 MPa, and then stirred at 25 ° C. for 24 hours. After completion of the reaction, the autoclave was decompressed, the reaction mixture was diluted with methylene chloride, and then 1.0 g of hydrochloric acid acidic methanol was added to stop the reaction. The mixture was concentrated under reduced pressure, 5 mL of chloroform was added to the obtained residue to dissolve it, and this solution was added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was filtered and dried under reduced pressure to obtain 1.30 g of aliphatic polycarbonate (yield 16%). The Mn of the obtained aliphatic polycarbonate was 2900.

FIG. 2 shows the ¹ H-NMR spectrum of the precursor of the graft copolymer obtained in Example 1d. From this ^{1 1} H-NMR, it was found that the content of the structural unit I represented by the above formula (1) was 2.5 mol% in the total structural units.

(Example: Synthesis of graft copolymer)
<Example 2a>
The graft copolymer was synthesized according to the reaction scheme shown in the following formula (S2-1). 0.20 g of the precursor obtained in Example 1b (0.097 mmol as the structural unit I represented by the above formula (1)) and cuprous bromide 2 in a 30 mL Schlenk tube containing a magnetic stirrer. 9. 9 mg (0.020 mmol) and 1.4 mg (0.0048 mmol) of tris (2-pyridylmethyl) amine (TPMA) were charged, and the inside of the container was replaced with an argon atmosphere. 2.1 mL (20 mmol) of methyl methacrylate (MMA) was charged and freeze-degassed. Then, the inside of the reaction vessel was replaced with argon again, and the mixture was stirred at 60 ° C. for 30 minutes. Air was blown into the contents to stop the reaction, and then 5 mL of dichloromethane was added to dissolve the contents. The organic layer was washed twice with 10 mL of 1N hydrochloric acid, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in 3 mL of chloroform and added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was collected by filtration and dried under reduced pressure to obtain 0.35 g of a colorless graft copolymer. The Mn of the obtained graft copolymer was 34100. The structure was identified by ^{1 1} H-NMR.

FIG. 3 shows a ¹ H-NMR spectrum of the graft copolymer obtained in Example 2a. From this ^{1 1} H-NMR, DP2 / DP1 = 1.0 of the graft copolymer obtained in Example 2a.

<Example 2b>
The graft copolymer was synthesized according to the reaction scheme represented by the following formula (S2-2). 0.20 g of the precursor obtained in Example 1b (0.097 mmol as the structural unit I represented by the above formula (1)) and cuprous bromide 2 in a 30 mL Schlenk tube containing a magnetic stirrer. .2 mg (0.015 mmol) and 1.1 mg (0.0038 mmol) of tris (2-pyridylmethyl) amine (TPMA) were charged, and the inside of the container was replaced with an argon atmosphere. 2.0 mL (2.4 mmol) of tetrahydrofuran and 2.0 mL (15 mmol) of glycidyl methacrylate (GMA) were charged, and freeze degassing was performed. Then, the inside of the reaction vessel was replaced with argon again, and the mixture was stirred at 30 ° C. for 1 hour. Air was blown into the contents to stop the reaction, and then 5 mL of dichloromethane was added to dissolve the contents. The organic layer was washed twice with 10 mL of 1N hydrochloric acid, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in 3 mL of chloroform and added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was collected by filtration and dried under reduced pressure to obtain 0.49 g of a colorless graft copolymer. The Mn of the obtained graft copolymer was 42500. The structure was identified by ^{1 1} H-NMR.

FIG. 4 shows the ¹ H-NMR spectrum of the graft copolymer obtained in Example 2b. From this ^{1 1} H-NMR, DP2 / DP1 = 1.6 of the graft copolymer obtained in Example 2b.

<Example 2c>
The graft copolymer was synthesized according to the reaction scheme represented by the following formula (S2-3). 0.20 g of the precursor obtained in Example 1b (0.097 mmol as the structural unit I represented by the above formula (1)) and cuprous bromide 2 in a 30 mL Schlenk tube containing a magnetic stirrer. .9 mg (0.020 mmol), 1.5 mg (0.005 mmol) of tris (2-pyridylmethyl) amine (TPMA), and 2.3 g (20 mmol) of N-isopropylacrylamide (NIPAM) were charged, and the inside of the container was filled with an argon atmosphere. Replaced with. 2.0 mL of tetrahydrofuran was charged and freeze-deaerated. Then, the inside of the reaction vessel was replaced with argon again, and the mixture was stirred at 60 ° C. for 30 hours. Air was blown into the contents to stop the reaction, and then 5 mL of dichloromethane was added to dissolve the contents. The organic layer was passed through an alumina column and concentrated under reduced pressure. The residue was dissolved in 3 mL of chloroform and added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was collected by filtration and dried under reduced pressure to obtain 0.15 g of a colorless graft copolymer. The Mn of the obtained graft copolymer was 35400. The structure was identified by ^{1 1} H-NMR. The graft copolymer obtained in Example 2c had DP2 / DP1 = 0.6.

<Example 2d>
0.20 g (side chain functional group 0.087 mmol) of the aliphatic polycarbonate obtained in Example 1c, 2.6 mg (0.018 mmol) of cuprous bromide, in a 30 mL Schlenk tube containing a magnetic stir bar. And 1.3 mg (0.005 mmol) of tris (2-pyridylmethyl) amine (TPMA) and 2.0 g (18 mmol) of N-isopropylacrylamide (NIPAM) were charged, and the inside of the container was replaced with an argon atmosphere. 2.0 mL of tetrahydrofuran was charged and freeze-deaerated. Then, the inside of the reaction vessel was replaced with argon again, and the mixture was stirred at 60 ° C. for 48 hours. Air was blown into the contents to stop the reaction, and then 5 mL of dichloromethane was added to dissolve the contents. The organic layer was passed through an alumina column and concentrated under reduced pressure. The residue was dissolved in 3 mL of chloroform and added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was collected by filtration and dried under reduced pressure to obtain 0.23 g of a colorless polypropylene carbonate-poly N-isopropylacrylamide graft copolymer. The Mn of the obtained graft copolymer was 51000.

FIG. 5 shows the ¹ H-NMR spectrum of the graft copolymer obtained in Example 2d. From this ^{1 1} H-NMR, DP2 / DP1 = 1.5 of the graft copolymer obtained in Example 2d.

<Example 2e>
The graft copolymer was synthesized according to the reaction scheme represented by the following formula (S2-4). 0.20 g of the precursor obtained in Example 1d (0.048 mmol as the structural unit I represented by the above formula (1)) and cuprous bromide 1 in a 30 mL Schlenk tube containing a magnetic stirrer. .8 mg (0.013 mmol) and 1.0 mg (0.006 mmol) of N, N, N ″, N ″, N ″ -pentamethyldiethylenetriamine (PMDTEA) were charged, and the inside of the container was replaced with an argon atmosphere. 1.3 mL (11.9 mmol) of styrene (St) was charged, and freeze degassing was performed. Then, the inside of the reaction vessel was replaced with argon again, and the mixture was stirred at 90 ° C. for 24 hours. Air was blown into the contents to stop the reaction, and then 5 mL of dichloromethane was added to dissolve the contents. The organic layer was washed twice with 10 mL of 1N hydrochloric acid, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in 3 mL of chloroform and added dropwise to 100 g of methanol to precipitate a solid. The obtained solid was collected by filtration and dried under reduced pressure to obtain 0.58 g of a colorless polypropylene carbonate-polystyrene graft copolymer. The Mn of the obtained graft copolymer was 16600. The structure was identified by ^{1 1} H-NMR.

FIG. 6 shows the ¹ H-NMR spectrum of the graft copolymer obtained in Example 2e. From this ^{1 1} H-NMR, DP2 / DP1 = 7.5 of the graft copolymer obtained in Example 2e.

Table 1 shows the physical properties of the precursor and the graft copolymer obtained in each example.

As described above, it was found that a desired graft copolymer can be produced by a polymerization reaction using a precursor, and that each obtained graft copolymer is produced from ¹ H-NMR with high purity. confirmed.

The graft copolymer of the present invention can be applied to a pyrolytic binder, a dispersant, a compatibilizer, a resin modifier, a substrate surface modifier, an adhesive, a paint, an additive such as an ink, and the like. is there.

Claims (9)

1. A graft copolymer having a stem polymer and a branch polymer bonded to the stem polymer.
   The trunk polymer is an aliphatic polycarbonate,
   A graft copolymer in which the branch polymer is a polymer of a radically polymerizable monomer.
2. The graft copolymer according to claim 1, wherein the aliphatic polycarbonate is a copolymer of carbon dioxide and epoxide.
3. The graft copolymer according to claim 1 or 2, wherein the radically polymerizable monomer is at least one selected from the group consisting of a styrene-based monomer, an unsaturated ester-based monomer, and an unsaturated amide-based monomer.
4. The method according to any one of claims 1 to 3, wherein the value of the ratio DP2 / DP1 of the number average degree of polymerization DP1 of the stem polymer to the number average degree of polymerization DP2 of the branch polymer is 0.1 or more and 10 or less. Graft copolymer.
5. A precursor of a graft copolymer,
   The stem polymer is aliphatic polycarbonate,
   The aliphatic polycarbonate is a precursor having a structural unit containing a functional group having a controlled radical polymerization initiation ability.
6. The precursor according to claim 5, wherein the aliphatic polycarbonate is a copolymer of carbon dioxide and epoxide.
7. The precursor according to claim 5 or 6, wherein the structural unit containing a functional group having a controlled radical polymerization initiation ability is contained in 1 mol% or more and 20 mol% or less in all the structural units of the aliphatic polycarbonate.
8. The precursor according to any one of claims 5 to 7, wherein the controlled radical polymerization is atom transfer radical polymerization, reversible addition cleavage chain transfer polymerization or nitroxide-mediated radical polymerization.
9. A method for producing a graft copolymer, comprising a step of carrying out a polymerization reaction using the precursor according to any one of claims 5 to 8.

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