JP3526978B2 - High epoxy value lactone polymer and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lactone polymer which is multi-branched and has a high epoxy group value (in this specification, the number of moles of epoxy group per 1 g of the polymer is shown). More specifically, it relates to a high-epoxy group lactone polymer which can be used in a wide range of applications such as adhesives, adhesives, cured materials, polymer plasticizers, polyester resin modifiers, compatibilizers and paints.

[0002]

[Problems to be Solved]
Polymer (A) having ˜5,000 hydroxyl groups is used as an initiator, and a lactone monomer is addition-polymerized thereto to give a flexible and processable high lactone having a large number of hydroxyl groups in the molecule. A polymer (B) was developed. It can be used in various applications such as adhesives, adhesives, paints, cured molding materials, and polymer plasticizers.

However, among these applications, there is a point to be improved because the lactone polymer terminal is a hydroxyl group. For example, when the terminal is a hydroxyl group when it is added to the epoxy resin for the purpose of imparting flexibility and low shrinkage, the curing reaction proceeds from the time of addition, and therefore, in the work step of obtaining a cured molded article, mixing is performed. The process to be carried out must be the final stage, which may reduce workability. Further, in the case of using it in a paint, when the terminal is a hydroxyl group, the curing partner is limited to isocyanate, melamine, epoxy, etc., and it cannot be used in a paint having a different curing system. Alternatively, in the use of a polymer plasticizer, a transesterification reaction may occur during melt-kneading with polyester, polycarbonate, etc., and the mechanical strength of the molded product may decrease.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems of the high hydroxyl value lactone polymer (B), the present inventor has used the high hydroxyl value lactone polymer (B) as a raw material, When a high epoxy value lactone polymer (E ₁ ) or (E ₂ ) having a large number of epoxy groups in the molecule was synthesized, not only the above problems were solved but also
By having an epoxy group at the end, the adhesive strength is significantly improved in the adhesive application of polyester film,
In the use as a modifier of polyester resin or polycarbonate resin, it has been found that physical properties such as thermal stability, moldability and impact resistance at low temperature are improved.

That is, according to the first aspect of the present invention, represented by the following general formula (1), the number of moles of epoxy group per 1 g of the polymer is 1 × 10 ⁻⁴ to 1 × 10 ⁻² mol, and the epoxy per molecule is epoxy. Number of bases is 10 to 5,000, number average molecular weight is 20,000
A high epoxy group value lactone polymer (E ₁ ) characterized by being in the range of ˜2,000,000 is provided.

[0006]

[Chemical 5]

The second aspect of the present invention relates to a method for producing the above-mentioned high epoxy group value lactone polymer (E ₁ ), which has 10
Characterized in that the hydroxyl groups of the high hydroxyl value lactone polymer (B) represented by the following general formula (1 ′) having ˜5,000 hydroxyl groups are reacted with epichlorohydrin or epibromohydrin. .

[0008]

[Chemical 6]

According to a third aspect of the present invention, represented by the following general formula (2), the number of moles of epoxy group per 1 g of the polymer is 1 × 10 ⁻⁴ to 1 × 10 ⁻² mol, and the epoxy group per molecule is epoxy. Number of bases is 10-5,000, number average molecular weight is 20,000-
There is provided a high epoxy valued lactone polymer (E ₂ ) characterized by being in the range of 2,000,000.

[0010]

[Chemical 7]

The fourth aspect of the present invention relates to a method for producing the above-mentioned high epoxy group value lactone polymer (E ₂ ), wherein
Highly unsaturated group-valued lactone polymer (D) represented by the following general formula (2 ′) having 0 to 5,000 unsaturated groups.
All or a part of the unsaturated groups in is treated with a peracid compound.

[0012]

[Chemical 8]

In the production of the high epoxy group value lactone polymer (E ₁ ) of the present invention, a polymer (A) having 10 to 5,000 hydroxyl groups in the molecule is used as an initiator and a lactone monomer is added thereto. The high hydroxyl value lactone polymer (B) represented by the general formula (1 ′) obtained by addition polymerization is used as a raw material. That is, it is produced by reacting the terminal hydroxyl group in this high hydroxyl value lactone polymer (B) with epichlorohydrin or epibromohydrin. Further, in order to produce the high-epoxy group lactone polymer (E ₂ ) of the present invention, a carboxylic acid having an unsaturated group for all or a part of the terminal hydroxyl groups in the high hydroxyl group lactone polymer (B) is used. By reacting with the derivative, a highly unsaturated group-valued lactone polymer (D) represented by the general formula (2 ′) is synthesized, and all or part of this unsaturated group is treated with a peracid compound.

Here, the polymer (A) having 10 to 5,000 hydroxyl groups in the molecule in these production methods.
Examples of the compound include completely or partially saponified polyvinyl alcohol, an oligomer of a compound having both a radical polymerizable double bond and a hydroxyl group in the molecule such as 2-hydroxyethyl methacrylate, and a copolymer with another radical polymerizable monomer. Examples include polymers and graft modified products of various polymers, hydrates of polydiene compounds, ethylene oxide metabolites of polyamides, ethylene oxide metabolites of polyphenols, polysaccharides, starch and cellulose. Generally, completely or partially saponified polyvinyl alcohol or a copolymer of 2-hydroxyethylmethacrylate and methylmethacrylate or styrene is preferably used.

The structures of the high epoxy group value lactone polymers (E ₁ ) and (E ₂ ) of the present invention are represented by the above general formula (1) or (2).

L in the general formulas (1) and (2) is an arbitrary monomer structural unit having no hydroxyl group and is not limited to one type. Specifically, aromatic monomers such as styrene, methyl methacrylate, acrylonitrile, acrylic monomers such as acrylic acid, diene monomers such as butadiene, vinyl monomers such as vinyl acetate and vinyl chloride, ethylene Examples thereof include olefin monomers such as phenylene oxide, and phenylene oxide. M in the formula is a monomer residue having a hydroxyl group in the molecule and is not limited to one type. Specifically, vinyl alcohol monomer residues produced by saponification of vinyl acetate, 2
-Hydroxyethyl (meth) acrylate monomer residue,
Examples thereof include 2-hydroxypropyl (meth) acrylate monomer residue and 4-hydroxybutyl vinyl ether monomer residue. A, b, c and n _{1 in the} general formula (1)
Represents the average degree of polymerization, 0 ≦ a ≦ 1,000, 10 ≦ b ≦
5,000, 0 ≦ c ≦ 1,000 and 2 ≦ n ₁ ≦ 30
Is the range. In this range, the number of moles of epoxy group per 1 g of the polymer is 1 × 10 ⁻⁴ to 1 × 10 ⁻² mol, the number of epoxy groups per molecule is 10 to 5,000, and the number average molecular weight is 20,000 to 2,000. It is set on the assumption that it is included in the range of 1,000. Similarly, d, e, f and n ₂ in the general formula (2) represent average degrees of polymerization, and 0 ≦ d ≦
1,000, 10 ≦ e ≦ 5,000, 0 ≦ f ≦ 1,000
The range is 0 and 2 ≦ n ₂ ≦ 30. This range is such that the number of moles of epoxy group per 1 g of the polymer is 1 × 10 ⁻⁴ to 1 × 1.
0 ^-2 mol, the number of epoxy groups per molecule is 10 to 5,0
00 and a number average molecular weight of 20,000 to 2,000,
It is set on the assumption that it is included in the range of 000.

Production of the high epoxy group lactone polymers (E ₁ ) and (E ₂ ) of the present invention ₁ in the molecule as a starting material
When the polymer (A) having a hydroxyl group of 0 to 5,000 is a completely saponified or partially saponified polyvinyl alcohol, the range of a, b, c and n ₁ is 0 ≦ a ≦ 5.
The ranges of 00, 100 ≦ b ≦ 5,000, 0 ≦ c ≦ 2,000 and 2 ≦ n ₁ ≦ 30 may be included in the above range.

G in the general formula (1) is a hydrogen atom or a substituent arbitrarily selected from the following formula, and g is an integer of 0 to 3. When epichlorohydrin or epibromohydrin is added to the hydroxyl group, a part of them may polymerize, and the value of g becomes 0 if no polymerization is carried out. Further, when G is a hydrogen atom, it basically does not react with the epoxy group existing in the molecule at room temperature or has extremely low reactivity.

[0019]

[Chemical 9]

R ¹ in the general formula (1) or (2) is an alkylene group having 2 to 10 carbon atoms, and specific examples thereof include an ethylene group, a butylene group, a pentylene group and a methylated pentylene group. Corresponds to the pentylene group in the case of ε-caprolactone which is the most industrially useful.

K in the general formula (2) is a hydrogen atom or a substituent selected from the following groups having an unsaturated group or an epoxy group in the molecule.

[0022]

[Chemical 10]

Each R ² in the formula is independently an alkylene group having 1 to 20 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group and an octylene group. Each R ³ in the formula is independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and particularly preferably a hydrogen atom, a methyl group, an ethyl group or the like. R ⁴ in the formula represents a residue having an alicyclic ring-constituting carbon atom, and such a residue may contain an oxygen atom. Specific examples of the structure of the substituent having an unsaturated group in the molecule before being epoxidized are as follows.

[0024]

[Chemical 11]

The number of moles of epoxy group per 1 g of the high epoxy group lactone polymer (E ₁ ) and (E ₂ ) of the present invention is 1.
X10 ^-4 to 1 x 10 ^-2 mol, preferably 5 x 1
0 ^{−4 to} 5 × 10 ⁻³ mol, more preferably 8 × 10 ⁻⁴ to
It is in the range of 3 × 10 ⁻³ mol. When the number of moles of the epoxy group is less than 1 × 10 ⁻⁴ mol, the amount of the epoxy group is small, and the advantage of having the epoxy group in applications such as adhesives, cured materials, and paints is lost, and conversely 1 × 10 ^−2. If it exceeds mol, the properties as a lactone polymer, particularly flexibility and processability are lost, and it becomes difficult to use for the above-mentioned applications, which is not preferable.

The above-mentioned number of moles of the epoxy group is obtained by calculating a theoretical value, or by instrumental analysis such as ¹ H-NMR measurement,
It can be measured by a known analysis method such as a titration method using bromic acid.

The number of epoxy groups per molecule of the high epoxy group lactone polymers (E ₁ ) and (E ₂ ) of the present invention is basically in the range of 10 to 5,000, preferably 50 to 50.
3,000, more preferably 100 to 2,000. If the number of epoxy groups is less than 10, the amount of epoxy groups is small, and the advantage of having an epoxy group is lost in applications such as adhesives, cured materials, and coatings.
Polymers exceeding 0 currently have no meaning and are not preferred because they are difficult to manufacture at present.

The high epoxy group lactone polymers (E ₁ ) and (E ₂ ) of the present invention have a number average molecular weight of 20,000.
0-2,000,000, preferably 50,000
0 to 1,000,000, more preferably 100,000
Is in the range of up to 500,000. The above molecular weight is 20,0
If it is less than 00, the balance between the epoxy group amount and the addition amount of the lactone monomer may be lost, and the epoxy group amount may decrease.
Alternatively, since properties as a lactone polymer, particularly flexibility and molding processability are lost, on the contrary, when it exceeds 2,000,000, the viscosity becomes too high, which causes a problem such as deterioration of molding processability. It is not preferred. The number average molecular weight can be measured by using a known method for measuring the number average molecular weight, and the method using GPC is the most simple and preferably used.

The high epoxy group-valued lactone polymers (E ₁ ) and (E ₂ ) of the present invention are changed from colorless and transparent liquid to transparent clay-like or wax-like depending on the number of lactone component chains, the degree of polymerization and the number of epoxy groups. , It has various forms such as white crystalline solid, and the physical properties of the product such as reactivity and moldability are different.
Therefore, it is desirable to adjust the number, composition, and structure of epoxy groups by controlling the raw materials, the feed composition, and the reaction conditions according to the application.

The high epoxy group lactone polymers (E ₁ ) and (E ₂ ) of the present invention may be mixed with any substance such as an organic solvent, a polymerizable monomer, a curing agent, a catalyst and a stabilizer depending on the use. It can be used without any problems. Less than,
The method for producing the high epoxy group lactone polymers (E ₁ ) and (E ₂ ) of the present invention will be described in more detail.

In order to produce the high epoxy group lactone polymer (E ₁ ), the lactone monomer is subjected to addition polymerization using the polymer (A) having 10 to 5,000 hydroxyl groups in the molecule as an initiator. It is a production method in which the terminal hydroxyl group of the high hydroxyl value lactone polymer (B) thus obtained is reacted with epichlorohydrin or epibromohydrin.

First, the polymer (A) having 10 to 5,000 hydroxyl groups used is as described above. Examples of the lactone monomer include methylated caprolactone such as ε-caprolactone and 4-methylcaprolactone, δ-valerolactone, β-propiolactone, and a mixture of two or more thereof, among which the most industrially useful. Ε-caprolactone is preferably used.

Further, in the production of the above-mentioned high hydroxyl value lactone polymer (B), a ring-opening addition polymerization catalyst of a lactone monomer is generally used. Specifically, an inorganic base,
Examples thereof include organic alkali metal catalysts, tin compounds, titanium compounds, aluminum compounds, zinc compounds, molybdenum compounds and zirconium compounds. Among them, tin compounds and titanium compounds are preferably used in terms of balance of ease of handling, low toxicity, reactivity, non-coloring property, thermal stability and the like. Specific examples of the tin compound include stannous chloride, stannous octylate, monobutyltin oxide, monobutyltin compounds such as monobutyltin tris (2-ethylhexanate), dibutyltin compounds such as dibutyltin oxide, and titanium compounds. Examples thereof include tetrabutyl titanate and tetraisopropyl titanate. These may be used alone or as a mixture. The addition polymerization of the lactone monomer, which is one step of these production methods, will be described in more detail.

As for the mixing ratio of the polymer (A) having a hydroxyl group and the lactone monomer, the ratio of the former (A) to the total of 100% is 0.1 to 30% by weight, preferably 1 -15% by weight, more preferably 2-1
It is in the range of 0% by weight. If the ratio is less than 0.1 parts by weight, the amount of hydroxyl groups is small, and eventually the amount of epoxy obtained by converting the hydroxyl groups is small, so that the high epoxy group lactone polymer (E) of the present invention is marketed. If it cannot be used and if it exceeds 30% by weight, the property as a lactone polymer, particularly the flexibility is lost, and the merit of using it as a pressure-sensitive adhesive, an adhesive, a coating polymer plasticizer, etc. is lost, which is not preferable.

The amount of the polymerization catalyst added is 0.001 to 0.1 part by weight, preferably 0.002 to 0.05 part by weight, more preferably 0.05, based on 100 parts by weight of both raw materials. ~ 0.01 parts by weight. The catalyst amount is 0.0
When the amount is less than 01 parts by weight, the polymerization rate of the lactone monomer is slow, and when the amount is more than 0.1 parts by weight, the obtained lactone polymer is colored or the thermal stability is deteriorated. It is not preferable because it may occur. The polymerization temperature is 5
0 to 250 ° C, preferably 100 to 220 ° C,
More preferably, it is in the range of 160 to 200 ° C. 50 ° C
If less than, the polymerization rate of the lactone monomer is slow,
On the other hand, if the temperature exceeds 250 ° C., a thermal decomposition reaction of the lactone polymer occurs, which causes coloration or a decomposed product, which is not preferable.

The reaction between the terminal hydroxyl group of the high hydroxyl group lactone polymer (B) produced in the above process and epichlorohydrin will be described in more detail.

The reaction between the terminal hydroxyl group of the high hydroxyl value lactone polymer (B) and epichlorohydrin or epibromohydrin can be easily carried out by mixing both at room temperature to 120 ° C. If the reaction temperature is lower than room temperature, the reaction rate is not sufficient, and cooling is not necessary. On the contrary, if the reaction temperature is higher than 120 ° C, epichlorohydrin is not preferable because it vaporizes at normal pressure, preferably 40 to 110 ° C. More preferably, it is in the range of 60 to 100 ° C. Further, the ratio of the number of moles of terminal hydroxyl groups of the high hydroxyl value lactone polymer (B) and the number of moles of epichlorohydrin (epibromohydrin) is within a range of 2: 1 to 1: 3. It can be easily set by adjusting. However, as the above-mentioned premise, it is necessary that the residual hydroxyl group in the produced high-epoxy group lactone polymer (E) does not react with the epoxy group at room temperature or has extremely low reactivity. For these reasons, it is desirable to use epichlorohydrin (epibromohydrin) in excess.

The reaction between the terminal hydroxyl group of the high hydroxyl value lactone polymer (B) and epichlorohydrin (or epibromohydrin) can be preferably carried out by dissolving both raw materials in an inert solvent. Examples of the inert solvent include aromatic hydrocarbons such as toluene and xylene, ether solvents and ester solvents.

In the method for producing the high epoxy group lactone polymer (E ₂ ) in the present invention, the route to the high hydroxyl group lactone polymer (B) is the same, but the lactone polymer (B) terminal hydroxyl group is the same. Is directly converted to an unsaturated group, or is once reacted with an acid anhydride to pass through a high acid value lactone polymer (C) to produce a high unsaturated value lactone polymer (D) converted to an unsaturated group. Then, all or part of the unsaturated group is treated with a peracid compound.

In this production method, the highly unsaturated lactone polymer (D) is used as a raw material. The highly unsaturated group lactone polymer (D) is produced by reacting the hydroxyl group of the high hydroxyl group lactone polymer (B) with a carboxylic acid derivative having an unsaturated group. The unsaturated carboxylic acid derivative is not particularly limited, but includes vinyl acetic acid, 3-hexenecarboxylic acid, 6-hexenecarboxylic acid, cyclohexenemethanol monoester of succinic acid and tetrahydrophthalic acid monoester, and these carboxylic acids. Examples thereof include acid halides and monobasic acid esters.

Further, a highly unsaturated lactone polymer (D)
Is obtained by reacting the high hydroxyl value lactone polymer (B) with succinic anhydride or tetrahydrophthalic anhydride and once converting it into the high acid value lactone polymer (C). In the case of succinic anhydride, allyl alcohol or In the case of an unsaturated alcohol such as cyclohexene methanol or tetrahydrophthalic anhydride, it can also be produced by esterification with a lower aliphatic alcohol such as methanol or ethanol.

The above-mentioned highly unsaturated lactone polymer (D)
The peroxy acid compound as the epoxidizing agent is not particularly limited, and known peroxy acid compounds can be used, but perhydrogen, peracetic acid, metachloroperbenzoic acid and the like are generally preferable.

The epoxidation reaction of unsaturated groups using these peracid compounds can be carried out by a known method without any problem.
Specifically, a method of mixing the highly unsaturated lactone polymer (D) and the peracid compound at a temperature of 0 to 100 ° C, preferably 20 to 80 ° C, more preferably 30 to 60 ° C can be mentioned. When the temperature is lower than 0 ° C, the reaction rate is slow, and when the temperature is 100 ° C or higher, the peroxide is decomposed or the reaction is too fast, so that the reaction heat cannot be controlled, which is not preferable.

When carrying out the epoxidation reaction of the highly unsaturated group-valued lactone polymer (D), dissolution in an inert solvent can be preferably employed. As the inert solvent, aromatic hydrocarbons such as toluene and xylene, heptane, aliphatic hydrocarbons such as cyclohexane, ester solvents such as ethyl acetate, ether solvents such as tetrahydrofuran, and mixed solvents thereof can be preferably used. .

[0045]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto.

(Production Example 1) 200 g of polyvinyl alcohol (A-1) ("PVA-403" manufactured by Kuraray Co., saponification degree 81.5 ± 1.5%, degree of polymerization 300) in a 2-liter glass flask. , Ε-caprolactone 1800g
And 0.20 g of tetrabutyl titanate as a polymerization catalyst was heated to 160 ° C. and melt-kneaded for 5 hours to obtain a high hydroxyl value lactone polymer (B-1). The standard polystyrene equivalent number average molecular weight of this product by GPC measurement was 158,000.

(Production Example 2) The high hydroxyl value lactone polymer (B obtained in Production Example 1 was added to a 1-liter glass flask.
-1) 300 g of tetrahydrophthalic anhydride and 60 g of tetrahydrophthalic anhydride were charged and mixed at 120 ° C for 1 hour to synthesize a high acid value lactone polymer (C-1) having an aliphatic cyclic unsaturated group. As it was, 45 g of cyclohexenylmethanol was added dropwise at 120 ° C., the temperature was raised to 150 ° C., nitrogen was introduced, and melt kneading was carried out for 10 hours while distilling water.
The thus-synthesized high-unsaturated lactone polymer (D-1) had a standard polystyrene-equivalent number average molecular weight of 184,000 as measured by GPC, and was used per 1 g of the polymer as determined by ¹ H-NMR measurement. The number of moles of unsaturated group is 1.
It was 9 × 10 ⁻³ mol / g.

(Example 1) The high hydroxyl value lactone polymer (B) obtained in Production Example 1 was placed in a 1-liter glass flask.
-1) 300 g, 200 ml of toluene as a solvent were charged, and 50 g of epichlorohydrin was added using a dropping funnel.
(1.5 times the molar equivalent of the primary hydroxyl group) was added dropwise at room temperature over 2 hours. After the temperature was raised to 40 ° C. as it was, stirring was continued for 3 hours, and then toluene was distilled off by vacuum distillation to obtain a high epoxy group lactone polymer (E-1). The standard polystyrene equivalent number average molecular weight of this product by GPC measurement and the number of moles of epoxy group per 1 g of polymer and the number of epoxy group per molecule determined by ¹ H-NMR measurement are shown in Table 1.

Example 2 A 1 liter glass flask was charged with 100 g of the highly unsaturated group-valued lactone polymer (D-1) obtained in Production Example 2 and 500 g of ethyl acetate as a solvent, and the dropping funnel was used. Then, 65 g of a 30 wt% ethyl acetate solution of peracetic acid was added dropwise at room temperature over 2 hours. The temperature was raised to 40 ° C., and stirring was continued for 3 hours. The system was cooled to room temperature, extracted with a 1% aqueous sodium hydroxide solution, and then washed twice with water for extraction. Ethyl acetate was caused to flow out by vacuum distillation of the organic layer to obtain a high epoxy group value lactone polymer (E-2). The same measurement as in Example 1 was performed for this product, and the results are shown in Table 1.

[0050]

[Table 1]

[0051]

According to the present invention, the number of moles of epoxy group per 1 g of the polymer is easily 1 × 10 ⁻⁴ to 1 × 10 ⁻² mol,
It is possible to obtain high epoxy group lactone polymers (E ₁ ) and (E ₂ ) having an epoxy group number of 10 to 5,000 and a number average molecular weight of 20,000 to 2,000,000 per molecule. . These have a high epoxy group value and can be widely used for adhesives, adhesives, cured materials, polymer plasticizers, polyester resin modifiers, compatibilizers, paints and the like.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP 62-11721 (JP, A) JP 7-149824 (JP, A) JP 8-151411 (JP, A) JP 8- 217820 (JP, A) JP 7-224146 (JP, A) JP 7-228824 (JP, A) JP 52-144100 (JP, A) JP 8-259667 (JP, A) JP-A-7-228827 (JP, A) JP-A-57-195714 (JP, A) JP-A-60-67516 (JP, A) JP-A-5-93008 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 59/00-59/72

Claims (4)

(57) [Claims] 1. A polymer represented by the following general formula (1): 1 g
The number of moles of epoxy group per unit is 1 × 10 ⁻⁴ to 1 × 10 ⁻² mo
1, a high epoxy group lactone polymer (E ₁ ) having an epoxy group number of 10 to 5,000 per molecule and a number average molecular weight of 20,000 to 2,000,000. [Chemical 1] 2. A hydroxyl group of a high hydroxyl value lactone polymer (B) represented by the following general formula (1 ′) having 10 to 5,000 hydroxyl groups in the molecule and epichlorohydrin or epibromohydrin. The method for producing a high epoxy group value lactone polymer (E ₁ ) according to claim 1, characterized by reacting with [Chemical 2] 3. A polymer represented by the following general formula (2): 1 g
The number of moles of epoxy group per unit is 1 × 10 ⁻⁴ to 1 × 10 ⁻² mo
1, a high epoxy group lactone polymer (E ₂ ) having an epoxy group number of 10 to 5,000 per molecule and a number average molecular weight of 20,000 to 2,000,000. [Chemical 3] 4. All or one of the unsaturated groups of the highly unsaturated lactone polymer (D) represented by the following general formula (2 ′) having 10 to 5,000 unsaturated groups in the molecule. 4. The method for producing a high epoxy group value lactone polymer (E ₂ ) according to claim 3, wherein the part is treated with a peracid compound. [Chemical 4]