JP2019065146A - Copolymer, composition, and copolymer production method - Google Patents

Abstract

To provide a copolymer improved in heat resistance.SOLUTION: The invention provides a copolymer represented by the general formula (1) in the figure. (In the general formula (1), l and m respectively represent molar percentage contents of A and B in the copolymer and satisfy l+m=1; A is a structural unit represented by a norbornene derivative; and B is a structural unit represented by a partially ring-opened and acid-treated derivative of maleic acid anhydride.)SELECTED DRAWING: None

Description

  The present invention relates to a copolymer, a composition, and a method for producing a copolymer.

  In the field of norbornene-maleic anhydride copolymers having structural units derived from norbornene and structural units derived from maleic anhydride, various techniques have been developed. In Patent Document 1, a copolymer of a cyclic aliphatic hydrocarbon and maleic anhydride is subjected to hydrolysis catalyzed by an inorganic alkali such as sodium hydroxide, a reaction with a compound having a hydroxyl group, or a compound having an amino group. It is described that the acid anhydride ring of the maleic anhydride structural unit is opened by the reaction.

Japanese Patent Application Laid-Open No. 2-146045

However, as a result of examining the heat resistance of the norbornene-maleic anhydride copolymer, as a result of the present inventor, when the structural unit derived from maleic anhydride is ring-opened by the hydrolysis described in Patent Document 1, It has been found that the heat resistance of the norbornene-maleic anhydride copolymer is insufficient.
Then, this invention makes it a subject to provide the copolymer which improved heat resistance.

In order to improve the heat resistance of a norbornene-maleic anhydride copolymer, the present inventor examined a method of ring-opening a structural unit derived from maleic anhydride. As a result, it is effective to open the structural unit derived from maleic anhydride using a Grignard reagent and that the norbornene-maleic anhydride copolymer has a specific structural unit to improve heat resistance. I found it.
As mentioned above, this inventor discovers that heat resistance can be improved because a norbornene-maleic anhydride copolymer is equipped with a specific structural unit, and the present invention was completed.

According to the invention
A copolymer represented by the following general formula (1) is provided.

（一般式（１）中、
ｌおよびｍはそれぞれ、共重合体中における、Ａ及びＢのモル含有率を示し、
ｌ＋ｍ＝１であり、
Ａは下記一般式（Ａ１）により示される構造単位であり、
Ｂは下記一般式（Ｂ２）により示される構造単位を含む。）

(In the general formula (1),
l and m respectively indicate the molar content of A and B in the copolymer,
l + m = 1,
A is a structural unit represented by the following general formula (A1),
B contains a structural unit represented by the following general formula (B2). )

（一般式（Ａ１）中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は、それぞれ独立して、水素または炭素数１以上３０以下の有機基であり、
ａ_１は０、１または２である。）

(In the general formula (A1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or an organic group having 1 to 30 carbon atoms,
a ₁ is 0, 1 or 2; )

（一般式（Ｂ２）中、Ｒ^Ｂ１は、炭素数１以上３０以下の有機基であり、
Ｒ^Ｂ１は、一般式（Ｂ２）中のＲ^Ｂ１が結合する炭素原子と、炭素−炭素結合を形成している。）

(In the general formula (B2), R ^B1 is an organic group having 1 to 30 carbon atoms,
R ^B1 is, the carbon atom ^{to which R B1} in the general formula (B2) are attached, a carbon - to form a carbon bond. )

  Further, according to the present invention, there is provided a composition comprising the above-mentioned copolymer.

Further, according to the present invention, there is provided a method of producing the above copolymer,
A polymerization process for obtaining an addition polymer by addition polymerization of a norbornene type monomer and maleic anhydride;
Next, a ring-opening step of ring-opening the addition polymer with a Grignard reagent and thereafter acid treatment to produce a copolymer represented by the general formula (1),
Then, a washing step of washing the copolymer represented by the general formula (1) such that the concentration of magnesium metal in the copolymer represented by the general formula (1) is 10.0 ppm or less depending on the solvent. There is provided a method of producing a copolymer, comprising

  According to the present invention, a copolymer with improved heat resistance is provided.

  The copolymer of the present embodiment is represented by the general formula (1) described later.

As a copolymer, a norbornene-maleic anhydride copolymer including a structural unit derived from a norbornene type monomer and a structural unit derived from maleic anhydride is known.
As a method of adjusting physical properties such as alkali solubility, flexibility, and solubility in a solvent of such a norbornene-maleic anhydride copolymer, structural units derived from maleic anhydride, for example, alcohols such as methanol and ethanol; n A method of hydrolyzing and opening an amine with an amine such as propylamine or isopropylamine has been known in the prior art. However, when ring-opening the norbornene-maleic anhydride copolymer with alcohol, there is a problem that the heat resistance is lowered.

Then, the present inventor examined the method of ring-opening the structural unit derived from the maleic anhydride of a norbornene-maleic anhydride copolymer. As a result, it is effective to improve heat resistance that a structural unit derived from maleic anhydride is opened using a Grignard reagent, and the norbornene-maleic anhydride copolymer has a specific structural unit. Found out. The detailed mechanism is not clear, but the reason is guessed as follows.
When ring-opening the structural unit derived from maleic anhydride of a norbornene-maleic anhydride copolymer by hydrolysis using a conventional alcohol, the structural unit derived from maleic anhydride and the structural unit derived from alcohol are Form an ester bond. It was speculated that this ester bond decomposes at high temperature and the heat resistance of the norbornene-maleic anhydride copolymer decreases. On the other hand, in the norbornene-maleic anhydride copolymer according to the present embodiment, a structural unit derived from maleic anhydride is opened with a Grignard reagent. In this case, the structural unit derived from maleic anhydride and the structural unit derived from the Grignard reagent form a carbon-carbon bond. And a carbon-carbon bond is guessed that decomposition temperature is high compared with an ester bond. Thereby, the decomposition temperature can be further improved as compared with a norbornene-maleic anhydride copolymer which is ring-opened by hydrolysis of a conventional alcohol. Thus, a norbornene-maleic anhydride copolymer in which a structural unit derived from maleic anhydride is ring-opened using a Grignard reagent is degraded as compared with a norbornene-maleic anhydride copolymer opened by a conventional method. It is estimated that heat resistance can be improved in terms of temperature.

The inventor further studied the heat resistance of the norbornene-maleic anhydride copolymer. As a result, a norbornene-maleic anhydride copolymer in which a structural unit derived from maleic anhydride is ring-opened using a Grignard reagent has a structure unit derived from maleic anhydride that is not ring-opened, or is hydrolyzed using an alcohol or the like. It has been found that heat resistance can be improved in terms of foaming temperature as compared to that obtained by ring opening. The detailed mechanism is not clear, but the reason is guessed as follows.
First, in the norbornene-maleic anhydride copolymer in which the structural unit derived from maleic anhydride is not ring-opened, the structural unit derived from maleic anhydride causes a decarboxylation reaction under high temperature to produce carbon dioxide, causing foaming and It is guessed that.
In addition, a norbornene-maleic anhydride copolymer opened by hydrolysis using an alcohol or the like forms an ester bond. This ester bond is presumed to decompose at high temperature to form an alcohol. This alcohol is considered to cause foaming.
On the other hand, a norbornene-maleic anhydride copolymer in which a structural unit derived from maleic anhydride is ring-opened using a Grignard reagent has a structural unit derived from maleic anhydride as compared with an unopened structural unit derived from maleic anhydride. There are few structural units. It is presumed that this can suppress foaming due to the decarboxylation reaction.
Furthermore, in a norbornene-maleic anhydride copolymer in which a structural unit derived from maleic anhydride is ring-opened using a Grignard reagent, a structural unit derived from maleic anhydride and a structural unit derived from a Grignard reagent have strong carbon -It forms a carbon bond, and even under high temperature, it is difficult to generate a release product from bond decomposition and does not cause foaming.

  From the above, it is presumed that the copolymer according to the present embodiment can improve heat resistance in a well-balanced manner from the viewpoints of both of the decomposition temperature and the foaming temperature by providing the specific structural unit.

  Hereinafter, the copolymer which concerns on this embodiment is demonstrated.

(Copolymer)
The copolymer which concerns on this embodiment is shown by following General formula (1).
As shown in the following general formula (1), the copolymer according to the present embodiment comprises a structural unit of A and a structural unit of B.

（一般式（１）中、
ｌおよびｍはそれぞれ、共重合体中における、Ａ及びＢのモル含有率を示し、
ｌ＋ｍ＝１であり、
Ａは下記一般式（Ａ１）により示される構造単位であり、
Ｂは下記一般式（Ｂ２）により示される構造単位を含む。）

(In the general formula (1),
l and m respectively indicate the molar content of A and B in the copolymer,
l + m = 1,
A is a structural unit represented by the following general formula (A1),
B contains a structural unit represented by the following general formula (B2). )

  In the above-mentioned copolymer, the arrangement of structural units of A and B is not limited. Specifically, a random copolymer, an alternating copolymer, a block copolymer, a periodic copolymer and the like can be selected as the arrangement of the structural units of A and B.

  The composition ratio of the structural unit of the above A to the structural unit of the above B in the copolymer will be described. In the copolymer, when the molar content (mol%) of the structural unit of the above A is l, and the molar content (mol%) of the structural unit of the above B is m, l + m = 1, for example, the numerical value of l The range is preferably 0.1 ≦ l ≦ 0.9. The numerical range of m is preferably 0.1 ≦ m ≦ 0.9.

First, the structural unit A of the copolymer represented by the above general formula (1) will be described.
In the copolymer represented by the above general formula (1), A is a structural unit derived from a norbornene type monomer. In the copolymer represented by the above general formula (1), A is a structural unit represented by the following general formula (A1).

（一般式（Ａ１）中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は、それぞれ独立して、水素または炭素数１以上３０以下の有機基であり、
ａ_１は０、１または２である。）

(In the general formula (A1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or an organic group having 1 to 30 carbon atoms,
a ₁ is 0, 1 or 2; )

In the embodiment, the organic groups having 1 to 30 carbon atoms constituting R ^{1 to} R ⁴ in the general formula (A1) each independently represent a hydrogen atom, a carbon atom, a silicon atom, a nitrogen atom, or phosphorus. It is a group formed by one or more atoms selected from the group consisting of atoms, oxygen atoms, sulfur atoms, fluorine atoms, chlorine atoms and bromine atoms. The organic group having 1 to 30 carbon atoms constituting R ^{1 to} R ⁴ is preferably, for example, a group formed of a hydrogen atom or a carbon atom.

In the embodiment, R ^{1 to} R ⁴ in the general formula (A1) are each independently hydrogen or an organic group having 1 to 30 carbon atoms, for example, hydrogen or 1 to 15 carbon atoms It is preferably an organic group, more preferably hydrogen or an organic group having 1 to 10 carbon atoms, and still more preferably hydrogen or an organic group having 1 to 3 carbon atoms.

In the present embodiment, examples of the organic group constituting R ^{1 to} R ⁴ in the general formula (A1) include an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkaryl group, a cyclopentadiene group Examples include alkyl groups, alkoxy groups and heterocyclic groups.
As an alkyl group, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, Examples include octyl group, nonyl group, and decyl group. As an alkenyl group, an allyl group, pentenyl group, and a vinyl group are mentioned, for example. The alkynyl group includes an ethynyl group. The alkylidene group includes, for example, a methylidene group and an ethylidene group. Examples of the aryl group include tolyl group, xylyl group, phenyl group, naphthyl group and anthracenyl group. As an aralkyl group, a benzyl group and a phenethyl group are mentioned, for example. Examples of the alkaryl group include tolyl group and xylyl group. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As an alkoxy group, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, s-butoxy group, isobutoxy group and t-butoxy group, n-pentyloxy group, neopentyloxy group And n-hexyloxy group. The heterocyclic group includes, for example, an epoxy group and an oxetanyl group.

In the embodiment, a ₁ in the general formula (A1) is 0, 1 or 2, and may be 0 or 1, or 0.

Next, the structural unit B of the copolymer represented by the above general formula (1) will be described. In the copolymer represented by the above general formula (1), B is a structural unit derived from maleic anhydride.
B of the copolymer shown by the said General formula (1) contains the structural unit which ring-opened the structural unit shown by following formula (B1) using a Grignard reagent.
The following general formula (B2) is a structural unit obtained by ring-opening the following formula (B1), which is a structural unit derived from maleic anhydride, using a Grignard reagent. Therefore, B of the copolymer shown by the said General formula (1) contains the structural unit shown by the following general formula (B2).

（一般式（Ｂ２）中、Ｒ^Ｂ１は、炭素数１以上３０以下の有機基であり、
Ｒ^Ｂ１は、一般式（Ｂ２）中のＲ^Ｂ１が結合する炭素原子と、炭素−炭素結合を形成している。）

(In the general formula (B2), R ^B1 is an organic group having 1 to 30 carbon atoms,
R ^B1 is, the carbon atom ^{to which R B1} in the general formula (B2) are attached, a carbon - to form a carbon bond. )

In the above general formula (B2), R ^B1 is derived from the Grignard reagent R ^B1 MgX. In the present embodiment, Mg represents a magnesium atom, and X represents a halogen atom such as a chlorine atom or a bromine atom.
In the above general formula (B2), R ^B1 forms a carbon-carbon bond with the carbon atom to which R ^B1 is bonded. That is, the carbon atom of the carboxyl group C = O in the general formula (B2) and R ^B1 form a carbon-carbon bond.

In the above general formula (B2), the organic group having 1 to 30 carbon atoms constituting R ^B1 is a hydrogen atom, a carbon atom, a silicon atom, a nitrogen atom, a phosphorus atom, an oxygen atom, a sulfur atom, a fluorine atom, a chlorine atom And a group formed by one or more atoms selected from the group consisting of bromine atoms.
Here, the organic group having 1 to 30 carbon atoms constituting R ¹ is formed of, for example, one or more atoms selected from the group consisting of a hydrogen atom, a carbon atom, a silicon atom, and a fluorine atom. It is preferable that it is a This can improve the cleavage temperature of the bond in R ¹ . Therefore, the heat resistance of the copolymer can be improved.
In the above general formula (B2), R ^B1 is preferably a hydrocarbon group formed of, for example, one or more atoms selected from the group consisting of a hydrogen atom and a carbon atom. Thus, it is possible to suppress the bond in R ^B1 is cleaved. Therefore, the heat resistance of the copolymer can be further improved. In the above general formula (B2), the hydrocarbon group in R ^B1 does not contain a hydrogen atom itself.

As an organic group which comprises R ^B1 in said general formula (B2), an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkaryl group, a cycloalkyl group, an alkoxy group, and a heterocyclic ring are mentioned, for example Groups are mentioned.
As an alkyl group, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, Examples include octyl group, nonyl group, and decyl group. As an alkenyl group, an allyl group, pentenyl group, and a vinyl group are mentioned, for example. The alkynyl group includes an ethynyl group. The alkylidene group includes, for example, a methylidene group and an ethylidene group. Examples of the aryl group include tolyl group, xylyl group, phenyl group, naphthyl group and anthracenyl group. As an aralkyl group, a benzyl group and a phenethyl group are mentioned, for example. Examples of the alkaryl group include tolyl group and xylyl group. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As an alkoxy group, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, s-butoxy group, isobutoxy group and t-butoxy group, n-pentyloxy group, neopentyloxy group And n-hexyloxy group. The heterocyclic group includes, for example, an epoxy group and an oxetanyl group.
As R ^B1 in the above general formula (B2), for example, one or more selected from the group consisting of an alkyl group, an alkenyl group and an alkynyl group is preferable, and an alkyl group or an alkenyl group is preferred. preferable. Thus, it is possible to suppress the bond in R ^B1 is cleaved. Therefore, the heat resistance of the copolymer can be improved.

  In the copolymer represented by the above general formula (1), B may be a ring-opened structural unit derived from a part of maleic anhydride. That is, B may further include the structural unit represented by the above formula (B1). When B contains both the structural unit represented by the above formula (B1) and the structural unit represented by the above general formula (B2), the weight reduction rate of the copolymer at a temperature of 300 ° C., and the foaming start temperature Such heat resistance can be improved with good balance.

  In the following general formula (B3), the structural unit of the above general formula (B2) may further include a structural unit in which a Grignard reagent is reacted. That is, in the copolymer represented by the general formula (1), B may further include a structural unit represented by the following general formula (B3).

（一般式（Ｂ３）中、Ｒ^Ｂ２、Ｒ^Ｂ３は、それぞれ独立して、炭素数１以上３０以下の有機基であり、
Ｒ^Ｂ２、Ｒ^Ｂ３は、それぞれ、上記一般式（Ｂ３）に示すＲ^Ｂ２、Ｒ^Ｂ３が結合する炭素原子と炭素−炭素結合を形成している。）

(In general formula (B3), R ^B2 and R ^B3 are each independently an organic group having 1 to 30 carbon atoms,
R ^B2 and R ^B3 respectively form a carbon-carbon bond with the carbon atom to which R ^B2 and R ^B3 shown in the above general formula (B3) are bonded. )

R ^B2 and R ^B3 in the general formula (B3) are derived from the Grignard reagents R ^B2 MgX and R ^B3 MgX. R ^B2 and R ^B3 in the general formula (B3) can be, for example, the same as R ^B1 in the general formula (B2).
In the copolymer represented by the above general formula (1), R ^B1 , R ^B2 and R ^B3 may have the same structure or different structures.

The lower limit value of the weight average molecular weight Mw of the copolymer according to the present embodiment is, for example, preferably 3000 or more, more preferably 5000 or more, still more preferably 10000 or more, and 11000 or more. Is more preferable, and 13,000 or more is particularly preferable. Thereby, the decomposition temperature of a copolymer can be raised and heat resistance can be improved.
In addition, the upper limit value of the weight average molecular weight Mw of the copolymer according to the present embodiment is, for example, 50000 or less, 30000 or less, and 20000 or less.

In addition, the upper limit value of the polydispersity of the copolymer according to the present embodiment may be, for example, 3.0 or less from the viewpoint of making the physical properties of each molecular chain of the copolymer uniform and improving the heat resistance. Preferably, it is 2.5 or less, more preferably 2.4 or less. This is preferable from the viewpoint of keeping the physical properties of the copolymer uniform and suppressing local thermal decomposition and foaming.
Further, from the same viewpoint as the upper limit value, the lower limit value of the polydispersity of the copolymer is preferably, for example, 1.0 or more.
In addition, polydispersity is represented by (weight average molecular weight Mw) / (number average molecular weight Mn), and means the dispersion degree which shows the width | variety of molecular weight distribution.

  In addition, the weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) use the polystyrene conversion value calculated | required from the calibration curve of standard polystyrene (PS) obtained, for example by GPC measurement.

(Method of producing copolymer)
The copolymer which concerns on this embodiment is manufactured as follows, for example.
First, in the polymerization step (S1), an addition polymer is obtained by addition polymerization of a norbornene type monomer and maleic anhydride. Next, in the ring opening step (S3), the addition polymer is ring-opened with a Grignard reagent, and then acid-treated to prepare a copolymer represented by the above general formula (1). Next, in the washing step (S4), the magnesium metal and the acid in the copolymer represented by the above general formula (1) are washed with a solvent.
In addition, after the polymerization step (S1), the low molecular weight component removal step (S2) may be performed before the ring opening step (S3). The low molecular weight component is removed from the addition polymer by the low molecular weight component removing step (S2).
The details of each step will be described below.

(Polymerization step (S1))
First, a polymerization step (S1) for obtaining an addition polymer by addition polymerization of a norbornene type monomer and maleic anhydride will be described.
First, a norbornene type monomer and maleic anhydride are prepared.
In the copolymer represented by the general formula (1), A is a structural unit derived from the norbornene type monomer. B is a structural unit derived from maleic anhydride.

As the norbornene type monomer, one represented by the following general formula (2) can be used. Following general formula ^(2), R 1 ~R ⁴ may be the same as ^R 1 to R ⁴ in the general formula (A1) described above.

（一般式（２）中、Ｒ^１〜Ｒ^４、ａ_１は、上記一般式（Ａ１）と同様である。）

(In the general formula (2), R ^{1 to} R ⁴ and a ₁ are the same as the above general formula (A1).)

  Specific examples of the norbornene type monomer represented by the above formula (2) include norbornene, norbornadiene, bicyclo [2.2.1] -hept-2-ene (conventional name: 2-norbornene), and 5-methyl-. 2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-allyl-2-norbornene, 5- (2-propenyl) ) -2-Norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, 5-ethynyl-2-norbornene, 5-benzyl-2-norbornene, 5-phenethyl-2-norbornene, 2-acetyl- 5-norbornene, methyl 5-norbornene-2-carboxylate, 5-norbornene-2,3-dicarboxylic acid anhydride, etc. It is. As a norbornene type monomer shown by said Formula (2), it can use combining 1 type, or 2 or more types among the said specific examples.

Then, a norbornene type monomer and maleic anhydride are addition-polymerized to synthesize an addition polymer. In addition, it does not restrict | limit limiting using 1 type, or 2 or more types of monomers as a norbornene type monomer.
Although the method of addition polymerization is not limited, in the present embodiment, an addition polymer is synthesized by radical polymerization using a radical polymerization initiator.
Here, a structural unit derived from a norbornene type monomer of the addition polymer is shown in the following general formula (A1). Further, a structural unit derived from maleic anhydride is shown in the following formula (B1).

（一般式（Ａ１）中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は、それぞれ独立して、水素または炭素数１以上３０以下の有機基であり、
ａ_１は０、１または２である。）

(In the general formula (A1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or an organic group having 1 to 30 carbon atoms,
a ₁ is 0, 1 or 2; )

The molar ratio of norbornene type monomer to maleic anhydride is preferably 0.5: 1 to 1: 0.5. Among these, from the viewpoint of molecular structure control, the molar ratio is preferably 1: 1.
A norbornene type monomer, maleic anhydride, and a polymerization initiator are dissolved in a solvent, and then heating is performed for a predetermined time to advance addition polymerization. The heating temperature is, for example, 50 ° C. or more and 80 ° C. or less, and the heating time is 5 hours or more and 20 hours or less.

As the polymerization initiator, for example, an azo compound or an organic peroxide can be used.
Specific examples of the azo compound include azobisisobutyronitrile (AIBN), dimethyl 2,2′-azobis (2-methylpropionate), 1,1′-azobis (cyclohexanecarbonitrile) (ABCN) Etc.
Further, as the organic peroxide, for example, hydrogen peroxide, ditertiary butyl peroxide (DTBP), benzoyl peroxide (benzoyl peroxide, BPO), methyl ethyl ketone peroxide (MEKP) and the like can be mentioned.
As a polymerization initiator, it can be used combining 1 type, or 2 or more types among the said specific examples.

  As the solvent in the addition polymerization, for example, one or more of diethyl ether, tetrahydrofuran, toluene and the like can be used.

According to the above-mentioned polymerization step (S1), an addition polymer which is a copolymer of a norbornene type monomer and maleic anhydride can be polymerized.
The arrangement of the addition polymer can be, for example, a random copolymer, an alternating copolymer, a block copolymer, or a periodic copolymer.

(Low molecular weight component removal process (S2))
After the polymerization step (S1), a low molecular weight component removal step (S2) may be performed before the ring opening step (S3). The low molecular weight component is removed from the addition polymer by the low molecular weight component removing step (S2). The specific method is described below.
The organic layer containing the addition polymer and the low molecular weight component is concentrated and then redissolved in an organic solvent such as tetrahydrofuran (THF) to obtain a solution. Then, hexane and methanol are added to the solution to coagulate and precipitate the addition polymer.
Here, as a low molecular weight component, a residual monomer, an oligomer, further, a polymerization initiator etc. are contained. Then, filtration is performed and the obtained coagulated material is dried. Thereby, an addition polymer from which low molecular weight components are removed can be obtained.

(Opening process (S3))
Next, in the ring-opening step (S3), the addition polymer is ring-opened using a Grignard reagent, and then acid-treated to prepare a copolymer represented by the above general formula (1).

The specific method of a ring-opening process is demonstrated.
Specifically, the Grignard reagent R ^B1 MgX is added to the solution containing the addition polymer, and an organic solvent such as an ether solvent or a hydrocarbon solvent is further added, and the temperature is −40 ° C. or more and 25 ° C. or less 10 The reaction solution L1 is obtained by stirring for a minute or more and 5 hours or less. In the reaction liquid L1, an anhydrous ring of a part of the structural unit derived from maleic anhydride of the addition polymer is opened. Thereby, the structural unit represented by the said Formula (B1) turns into a structural unit represented by a following formula (B2).

In addition, among the structural units represented by the above general formula (B2 ′), although they are slight, they may be further reacted with a Grignard reagent to form a structural unit represented by the following general formula (B3 ′).
In the following general formula (B3 ^'), although the R ^{B2, R B3,} when using a Grignard reagent ^R B1 MGX1 species ^only, R ^{B2, R B3 are} the same as ^{R B1.}

Then, an acid such as hydrochloric acid, formic acid or sulfuric acid is added to the reaction liquid L1 to replace MgX in the above general formula (B2 ') with a proton (H ⁺ ). Thereby, the structural unit represented by the said general formula (B2 ') will be represented by the following general formula (B2). The structural unit represented by the above general formula (B3 ′) is represented by the following general formula (B3). Thereby, the copolymer shown by the said General formula (1) can be produced.

（一般式（Ｂ２）中、Ｒ^Ｂ１は、炭素数１以上３０以下の有機基であり、
Ｒ^Ｂ１は、一般式（Ｂ２）中のＲ^Ｂ１が結合する炭素原子と、炭素−炭素結合を形成している。）

(In the general formula (B2), R ^B1 is an organic group having 1 to 30 carbon atoms,
R ^B1 is, the carbon atom ^{to which R B1} in the general formula (B2) are attached, a carbon - to form a carbon bond. )

（一般式（Ｂ３）中、Ｒ^Ｂ２、Ｒ^Ｂ３は、それぞれ独立して、炭素数１以上３０以下の有機基であり、
Ｒ^Ｂ２、Ｒ^Ｂ３は、それぞれ、上記一般式（Ｂ３）に示すＲ^Ｂ２、Ｒ^Ｂ３が結合する炭素原子と炭素−炭素結合を形成している。）

(In general formula (B3), R ^B2 and R ^B3 are each independently an organic group having 1 to 30 carbon atoms,
R ^B2 and R ^B3 respectively form a carbon-carbon bond with the carbon atom to which R ^B2 and R ^B3 shown in the above general formula (B3) are bonded. )

  Specific examples of the Grignard reagent added in the ring-opening step include methylmagnesium chloride, methylmagnesium bromide, ethylmagnesium chloride, isopropylmagnesium chloride, 1-butylmagnesium chloride, 2-butylmagnesium chloride, tert-butylmagnesium chloride, alkylmagnesium halides such as sec-butylmagnesium chloride; alkenylmagnesium halides such as vinylmagnesium bromide and allylmagnesium chloride; arylmagnesium halides such as pentafluorophenylmagnesium bromide and phenylmagnesium chloride; halogenated aralkyls such as benzylmagnesium chloride Magnesium; trimethylsilylmethyl magnesium chloride, di Halogenated silylated alkylmagnesium, such as methyl ethyl silyl methyl chloride and the like. As the Grignard reagent, one or more of the above specific examples can be used in combination. Among the above specific examples, it is preferable to use, for example, halogenated alkyl magnesium or halogenated alkenyl magnesium as the Grignard reagent added in the ring opening step. Thereby, the heat resistance of the copolymer can be improved.

The lower limit value of the number of moles of the Grignard reagent added in the ring-opening step is, for example, preferably 20 mol% or more, more preferably 40 mol% or more, with respect to the maleic anhydride used in the polymerization step. It is more preferable that it is 60 mol% or more, and it is more preferable that it is 80 mol% or more. This makes it possible to obtain a copolymer in which the structural unit derived from maleic anhydride is sufficiently ring-opened. Therefore, the heat resistance of the copolymer can be improved.
Further, the upper limit value of the number of moles of the Grignard reagent added in the ring-opening step is, for example, preferably 200 mol% or less, more preferably 180 mol% or less based on the maleic anhydride used in the polymerization step. Preferably, it is more preferably 160 mol% or less. If a metal such as magnesium remains, the deterioration of the copolymer proceeds and the heat resistance decreases. In addition, if a metal such as magnesium remains, it causes coloring. When the number of moles of the Grignard reagent to be added is equal to or less than the above upper limit, the concentration of magnesium metal in the copolymer can be reduced, which is advantageous in that the heat resistance can be reduced and the occurrence of coloring can be suppressed.

(Washing process (S4))
After the ring opening step (S3), a washing step (S4) is carried out.
In the washing step, the solvent is used to wash the magnesium metal and the acid in the copolymer. Here, as the solvent, for example, a mixture of water and an organic solvent (for example, methyl ethyl ketone) can be used. The specific method is described below.
The copolymer obtained in the above-mentioned ring-opening process is washed with a solvent to remove residual metal components. The copolymer, residual monomers and oligomers migrate to the organic layer. Then remove the aqueous layer (first wash). Then, again, a mixture of water and an organic solvent (for example, methyl ethyl ketone) is added to the organic layer and washed (second washing). In the present embodiment, the metallic magnesium remaining is removed by performing the cleaning step (S4) consisting of the first cleaning and the second cleaning as described above a plurality of times.
The washing step (S4) is preferably performed multiple times so that the magnesium metal concentration in the copolymer is, for example, 10.0 ppm or less, preferably 5.0 ppm or less. Thereby, heat resistance can be improved from a viewpoint which can suppress that a copolymer discolors at the time of heat.

(Composition)
The copolymer according to this embodiment may be used as a composition, for example, by mixing with other components.

  Note that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like as long as the object of the present invention can be achieved are included in the present invention.

  Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the description of these examples.

(Synthesis of copolymer)
First, the synthesis of the addition polymer used in each example and each comparative example, that is, the copolymer before ring opening will be described.
First, 29.42 g (0.3 mol) of maleic anhydride (hereinafter also referred to as MA) and 2-norbornene (hereinafter also referred to as NB) are provided in an appropriately sized reaction vessel equipped with a stirrer and a condenser. 28.25 g (0.3 mol) and 3.07 g (13.3 mmol) of dimethyl 2,2'-azobis (2-methyl propionate) were weighed, and 44.5 g of methyl ethyl ketone (hereinafter also referred to as MEK) was weighed. The mixture was dissolved in a mixed solvent of 22.9 g of toluene to prepare a solution. The solution is purged with nitrogen for 20 minutes to remove oxygen, and then heated with stirring at a temperature of 65 ° C. for 6 hours to polymerize maleic anhydride and 2-norbornene to form a polymerization solution. Was produced. The obtained polymerization solution was diluted with 64.07 g of MEK to prepare a dilution solution, and then a white solid was reprecipitated by dropping the solution for dilution into 778.5 g of butanol. The white solid thus obtained is vacuum dried at a temperature of 50 ° C. to obtain 43.99 g of a copolymer before ring opening comprising a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride Obtained.

Example 1
As Example 1, the copolymer which ring-opened the copolymer provided with the structural unit derived from 2- norbornene, and the structural unit derived from maleic anhydride was produced. Details will be described below.
First, 48.9 g of tetrahydrofuran (hereinafter also referred to as THF) and 60.6 g of toluene are added to 10 g (0.052 mol in terms of MA) of the above-described copolymer before ring opening, A solution in which the copolymer was dissolved was prepared. Next, 14% vinylmagnesium bromide THF solution (48.78 g, 0.052 mol) was added to the solution, and the mixture was reacted at a temperature of -40 ° C for 1 hour to prepare a reaction solution.
The reaction solution was then treated with aqueous formic acid to remove the aqueous phase from the reaction solution. Water was then added and again treated with aqueous formic acid to remove the aqueous phase. It was then reprecipitated with heptane. As a result, 9.30 g of the copolymer of Example 1 was obtained in which the copolymer having the structural unit derived from 2-norbornene and the structural unit derived from maleic anhydride was ring-opened with vinyl magnesium bromide. .
Moreover, about the solid content of the copolymer of Example 1, ¹ H-NMR measurement was performed. As a result, three peaks were confirmed at 4.9 ppm, 5.1 ppm and 5.9 ppm which were not confirmed in the copolymer before ring opening. The area ratio of these three peaks was the same. Thereby, it was confirmed that the copolymer of Example 1 forms acryloyl group. That is, it was confirmed that in the copolymer of Example 1, the structural unit derived from maleic anhydride was ring-opened by vinyl magnesium bromide.
In addition, the copolymer of Example 1 obtained was measured using the inductively coupled plasma mass spectrometer (Inductively Coupled Plasma Mass Spectrometry: ICP-MS). As a result, the magnesium concentration in the copolymer of Example 1 was 2.7 ppm.
Moreover, as a result of measuring the obtained copolymer of Example 1 using gel permeation chromatography (Gel Permeation Chromatography: GPC), the weight average molecular weight Mw is 17500, and the polydispersity (weight average molecular weight Mw) / (Number average molecular weight Mn) was 2.31.

(Example 2)
As Example 2, a copolymer comprising a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride was ring-opened with butylmagnesium bromide to prepare a copolymer. Details will be described below.
First, a solution obtained by adding 32.4 g of THF and 45.0 g of toluene to 10 g (0.052 mol in terms of MA) of the above-mentioned copolymer before ring opening was dissolved in the copolymer before ring opening. Was produced. Next, 33.57 g (0.052 mol) of 25% butylmagnesium bromide THF solution was added to the solution, and the mixture was reacted at a temperature of 0 ° C. for 1 hour to prepare a reaction solution.
The reaction solution was then treated with aqueous formic acid to remove the aqueous phase from the reaction solution. Water was then added and again treated with aqueous formic acid to remove the aqueous phase. It was then reprecipitated with heptane. As a result, 10.08 g of the copolymer of Example 2 was obtained in which the copolymer having the structural unit derived from 2-norbornene and the structural unit derived from maleic anhydride was ring-opened with butyl magnesium bromide. .
Moreover, about the solid content of the copolymer of Example 2, ¹ H-NMR measurement was performed similarly to Example 1. Thus, it was confirmed that the structural unit derived from maleic anhydride of the copolymer was ring-opened by butylmagnesium bromide for the copolymer of Example 2.
Moreover, the copolymer of Example 2 obtained was measured using ICP-MS. As a result, the magnesium concentration in the copolymer of Example 2 was 2.7 ppm.
Moreover, as a result of measuring the obtained copolymer of Example 2 using gel permeation chromatography (GPC), the weight average molecular weight Mw is 13700, and the polydispersity (weight average molecular weight Mw) / (Number average molecular weight Mn) was 1.83.

(Example 3)
As Example 3, a copolymer comprising a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride was ring-opened with methyl magnesium bromide to prepare a copolymer. Details will be described below.
First, a solution in which 53.4 g of THF and 52.1 g of toluene are added to 10 g (0.052 mol in terms of MA) of the above-described copolymer before ring opening to dissolve the copolymer before the ring opening Was produced. Next, 77.55 g (0.078 mol) of a 12% solution of methylmagnesium bromide in THF was added to the solution and reacted at a temperature of 0 ° C. for 1 hour to prepare a reaction solution.
The reaction solution was then treated with aqueous formic acid to remove the aqueous phase from the reaction solution. Water was then added and again treated with aqueous formic acid to remove the aqueous phase. The copolymer of Example 3 was then reprecipitated with heptane, and the copolymer comprising the structural unit derived from 2-norbornene and the structural unit derived from maleic anhydride was ring-opened with methyl magnesium bromide. I got 8.36g.
Moreover, about the solid content of the copolymer of Example 3, ¹ H-NMR measurement was performed similarly to Example 1. This confirmed that the structural unit derived from the maleic anhydride of the copolymer was ring-opened by methyl magnesium bromide about the copolymer of Example 3.
Moreover, the copolymer of Example 3 obtained was measured using ICP-MS. As a result, the magnesium concentration in the copolymer of Example 3 was 4.0 ppm.
Moreover, as a result of measuring the obtained copolymer of Example 3 using gel permeation chromatography (GPC), the weight average molecular weight Mw is 11900, and the polydispersity (weight average molecular weight Mw) / (Number average molecular weight Mn) was 1.89.

The following experiment was performed to confirm that the obtained copolymer of Example 3 contained a structural unit derived from unopened maleic anhydride.
First, as Reference Example 1, the copolymer of Reference Example 1 in which the addition amount of the 12% methylmagnesium bromide THF solution was increased to 116.33 g (0.117 mol) in the method for producing the copolymer of Example 3 described above. Was produced.
Next, the copolymer of Example 3 and Reference Example 1 was dissolved in PGMEA, and then a resin film formed by spin coating on a wafer was prebaked at a temperature of 120 ° C. for 4 minutes to produce a resin film. The alkali solubility rate of this resin film was measured using a 2% aqueous Na ₂ CO ₃ solution at a temperature of 23 ° C. As a result, the alkali solubility rate of the resin film using the copolymer of Example 3 was 18 nm / sec. On the other hand, the alkali solubility rate of the resin film using the copolymer of Reference Example 1 was 120 nm / min. From this, it was confirmed that unopened structural units derived from maleic anhydride remain in the copolymer of Example 3.
Moreover, it confirmed that the structural unit derived from the non-ring-opened maleic anhydride remained in the copolymer of Examples 1-2 by the same method.

(Comparative example 1)
As the copolymer of Comparative Example 1, the above-described copolymer before ring opening was used.
In addition, as a result of measuring the copolymer of Comparative Example 1 using gel permeation chromatography (Gel Permeation Chromatography: GPC), the weight average molecular weight Mw is 12700, and the polydispersity (weight average molecular weight Mw) / (number of particles) The average molecular weight Mn) was 1.92.

(Comparative example 2)
As Comparative Example 2, a copolymer was prepared by ring-opening a copolymer comprising a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride using butanol. Details will be described below.
First, 125.0 g (1.7 mol) of butanol is added to 25 g (0.13 mol in terms of MA) of the above-described copolymer before ring-opening, and heat treatment is carried out at a temperature of 110 for 12 hours. The acid structural unit was reacted with butanol for ring opening. Subsequently, reprecipitation is carried out with heptane, and the copolymer of Comparative Example 2 in which a copolymer comprising a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride is ring-opened using butanol I got 23.81 g.
In addition, as a result of measuring the obtained copolymer of Comparative Example 2 using gel permeation chromatography (GPC), the weight average molecular weight Mw is 13100, and the polydispersity (weight average molecular weight Mw) / (Number average molecular weight Mn) was 1.61.

(Comparative example 3)
As Comparative Example 3, a copolymer was prepared by ring opening a copolymer having a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride using butylamine. Details will be described below.
First, 60.0 g of dimethylacetamide (hereinafter also referred to as DMAc) is added to 15 g (0.08 mol in terms of MA) of the above-mentioned copolymer before ring opening and dissolved, and then 2.85 g (0.039 mol) of butylamine The reaction mixture was heated at a temperature of 80 ° C. for 4 hours to cause a reaction of ring opening of the maleic anhydride structural unit of the copolymer with butylamine to obtain a reaction solution. Subsequently, reprecipitation is carried out with heptane, and the copolymer of Comparative Example 3 in which a copolymer comprising a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride is ring-opened using butylamine I obtained 14.93 g.
In addition, as a result of measuring the obtained copolymer of Comparative Example 3 using gel permeation chromatography (GPC), the weight average molecular weight Mw is 9500, and the polydispersity (weight average molecular weight Mw) / (Number average molecular weight Mn) was 1.70.

(Heat-resistant)
The heat resistance of each Example and each comparative example was evaluated. The detailed method is described below.
As evaluation of heat resistance, measurement is performed under conditions of temperature 30 ° C. to 500 ° C., temperature rising rate 10 ° / min, sample weight 1 mg, nitrogen atmosphere using TG-DTA apparatus (manufactured by Hitachi High-Tech Science, STA7200 RV) The weight loss rate at a temperature of 300 ° C. was evaluated to evaluate the decomposition temperature. Further, the morphology was observed by a CCD camera, and the foaming start temperature was evaluated. The evaluation results are shown in Table 1 below.
In addition, it is a favorable result that foaming start temperature is 270 degreeC or more.

As shown in Table 1 above, the copolymer of each example has a smaller weight reduction rate at 300 ° C. than the copolymer of each comparative example, that is, it is excellent in heat resistance in terms of decomposition temperature Was confirmed. Moreover, it was confirmed that the copolymer of each example is excellent in heat resistance in terms of the foaming start temperature as compared with the copolymer of each comparative example.
As mentioned above, it was confirmed that heat resistance is improved with good balance from a viewpoint of both decomposition temperature and foaming temperature compared with a copolymer of each comparative example compared with a copolymer of each comparative example.

Claims (10)

The copolymer shown by following General formula (1).

(In the general formula (1),
l and m respectively indicate the molar content of A and B in the copolymer,
l + m = 1,
A is a structural unit represented by the following general formula (A1),
B contains a structural unit represented by the following general formula (B2). )

(In the general formula (A1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or an organic group having 1 to 30 carbon atoms,
a ₁ is 0, 1 or 2; )

(In the general formula (B2), R ^B1 is an organic group having 1 to 30 carbon atoms,
R ^B1 is, the carbon atom ^{to which R B1} in the general formula (B2) are attached, a carbon - to form a carbon bond. ) A copolymer according to claim 1, which is
In the copolymer shown by the said General formula (1), said B is a copolymer which further contains the structural unit of following formula (B1).

A copolymer according to claim 1 or 2, wherein
In the general formula (B2), a copolymer in which R ^B1 is a group formed by one or more atoms selected from the group consisting of a hydrogen atom, a carbon atom, a silicon atom and a fluorine atom. A copolymer according to any one of claims 1 to 3, which is
In the above general formula (B2), a copolymer in which R ^B1 is a hydrocarbon group having 1 to 30 carbon atoms. The copolymer according to any one of claims 1 to 4, wherein
In the general formula (B2), a copolymer in which R ^B1 is an alkyl group having 1 to 30 carbon atoms or an alkenyl group. The copolymer according to any one of claims 1 to 5, wherein
A copolymer wherein the magnesium metal concentration in the copolymer is 10.0 ppm or less.   A composition comprising the copolymer according to claim 1. A method for producing the copolymer according to any one of claims 1 to 6, wherein
A polymerization process for obtaining an addition polymer by addition polymerization of a norbornene type monomer and maleic anhydride;
Next, a ring-opening step of ring-opening the addition polymer with a Grignard reagent and thereafter acid treatment to produce a copolymer represented by the general formula (1),
Then, a washing step of washing the copolymer represented by the general formula (1) such that the concentration of magnesium metal in the copolymer represented by the general formula (1) is 10.0 ppm or less depending on the solvent. A method of producing a copolymer, comprising A method for producing the copolymer according to claim 8, wherein
The method for producing a copolymer, wherein the Grignard reagent is one or more selected from the group consisting of halogenated alkyl magnesium, halogenated alkenyl magnesium, halogenated aryl magnesium, halogenated aralkyl magnesium and halogenated silylated alkyl magnesium . A method for producing a copolymer according to claim 8 or 9,
In the ring-opening step, a copolymer is prepared by ring-opening the addition polymer by adding 20 mol% or more and 200 mol% or less of the Grignard reagent to the maleic anhydride used in the polymerization step. Method.