JPH11349640A - Graft-modified copolymer, its production, and resin composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a graft-modified copolymer having improved compatibility with a synthetic resin such as a polar resin by copolymerizing isobutylene with β-pinene in the presence of an initiator system comprising a specified organic compound and a Lewis acid and graft-modifying the copolymer with an unsaturated carboxylic acid. SOLUTION: An initiator is obtained by mixing an organic compound having in the molecule at least one group of the formula (whereon A<1> and A<2> are each an alkyl, an aryl, or an aralkyl; and X is an acyloxy, an alkoxyl, hydroxyl, or a halogen) with a Lewis acid in an amount of 1-100 mol, per mol of groups of the formula and an organic Lewis acid base in an amount of 0.1-100 mol per mol of groups of the formula. An addition copolymer obtained by addition- copolymerizing 50-99.5 wt.% isobutylene with 0.05-50 wt.% β-pinene as a comonomer at -150 to +50 deg.C in the presence of the above initiator system and having a number-average molecular weight of 2,000-10,000 is graft-modified with an unsaturated carboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified copolymer having good miscibility with a synthetic resin, obtained by polymerizing a monomer mainly composed of isobutylene and then graft-modifying the monomer with an unsaturated carboxylic acid. The present invention also relates to a method for producing the modified copolymer and a resin composition containing the modified copolymer, which is excellent in impact resistance, flexibility, gas barrier properties, and the like.

[0002]

2. Description of the Related Art It is known that an elastomer obtained by polymerizing a monomer mainly composed of isobutylene has excellent flexibility, vibration damping properties, gas barrier properties and the like. In addition, there has been proposed a method of imparting properties such as impact resistance, flexibility, gas barrier properties, and vibration damping properties by blending or alloying an isobutylene-based polymer with various synthetic resins.
However, since the isobutylene-based polymer has insufficient miscibility with polar resins such as polyamide and polyester-based resins in particular, the above-mentioned blends or alloys have excellent inherent strength such as mechanical strength. It is difficult to maintain sufficient mechanical properties. Therefore, in order to improve this point, a block copolymer having an isobutylene polymer block and a styrene-carboxystyrene copolymer block has been proposed as a functionalized isobutylene-based polymer (Japanese Patent Publication No. Hei 7-1995). 100
No. 763).

[0003]

The isobutylene-based polymer has an isobutylene unit as a main structural unit, and therefore has poor radical reactivity in chemical structure, and is grafted with an unsaturated carboxylic acid such as acrylic acid or maleic anhydride. Functionalization by denaturation is not easy. Therefore, the block copolymer having the isobutylene polymer block and the styrene-carboxystyrene copolymer block is a block copolymer having an isobutylene polymer block and a styrene polymer block by first polymerizing isobutylene and styrene. And then lithiating the block copolymer and reacting it with carbon dioxide. Thus, one of the objects of the present invention is to have a chemical structure consisting of a trunk formed from a monomer mainly composed of isobutylene and a graft branch formed from unsaturated carboxylic acids, and to a synthetic resin such as a polar resin. To provide a novel modified copolymer having good miscibility. Another object of the present invention is to provide a method for easily producing the modified copolymer. Another object of the present invention is to provide a resin composition modified with the modified copolymer.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have studied and found that β-pinene can be easily copolymerized with an addition-polymerizable monomer such as isobutylene,
Being able to introduce a highly radically reactive partial structure such as a carbon-carbon unsaturated bond, a methylene group or a methine group adjacent to an unsaturated bond into a polymer chain derived from copolymerization of β-pinene. Have been found, and as a result of further study, the present invention has been completed.

That is, according to the present invention, there is provided a modified copolymer obtained by graft-modifying an addition copolymer of isobutylene as a main monomer and β-pinene as a comonomer with unsaturated carboxylic acids.

According to the present invention,

(A) General formula

[0008]

Embedded image -C (-A ¹ ) (-A ² ) -X (1)

(In the formula, A ¹ and A ² each represent an alkyl group, an aryl group or an aralkyl group, and X represents an acyloxy group, an alkoxyl group, a hydroxyl group or a halogen atom.)

The copolymerization is carried out by polymerizing isobutylene as a main monomer and β-pinene as a comonomer using an initiator system comprising an organic compound containing at least one group represented by the following formula and a Lewis acid. Get coalesced, then

(B) graft-modifying the copolymer with unsaturated carboxylic acids;

[0012] A method for producing the above modified copolymer is provided.

Further, according to the present invention, there is provided a resin composition comprising the above modified copolymer and a synthetic resin.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The modified copolymer of the present invention is obtained by graft-modifying an addition copolymer obtained by addition-copolymerizing isobutylene as a main monomer and β-pinene as a comonomer with unsaturated carboxylic acids. It is manufactured by doing.

It is known that β-pinene is polymerized with an isomerization reaction as shown in the following reaction formula (2) in cationic polymerization (JPKennedy, E. Marechal, “Carboca
tionic Polymerization "(1991, Krieger Publi, USA
shing Company), page 492).

[0016]

Embedded image

Therefore, in the above addition copolymer, β-pinene has the formula

[0018]

Embedded image

It is presumed to form the structural unit represented by

In addition copolymerization of isobutylene and β-pinene, other comonomers may be copolymerized in addition to these. Such other comonomers include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, chlorostyrene, dichlorostyrene, trichlorostyrene, t-butylstyrene, methoxystyrene,
Styrene compounds such as α-methylstyrene, β-methylstyrene, (chloromethyl) styrene, (bromomethyl) styrene, etc .; vinyl ether compounds such as vinyl methyl ether; N-vinylcarbazole; indene; one or two kinds such as acenaphthylene The above can be used.

The proportion of each monomer (isobutylene, β-pinene and other comonomer used as needed) in the addition copolymerization is not necessarily limited as long as isobutylene is the main component. The amount of isobutylene used is in the range of 50 to 99.5% by weight, the amount of β-pinene is used in the range of 0.05 to 50% by weight, and the amount of other comonomers is based on all monomers. By adjusting the amount to fall within the range of 0 to 49.05% by weight, the modified copolymer in which the miscibility with the resin is particularly greatly improved while maintaining the properties of the isobutylene-based polymer can be obtained after the addition copolymerization. It is preferable because it can be easily obtained by graft modification.

With respect to the form of the addition copolymer of the monomers (isobutylene, β-pinene and other comonomers used as required), the monomer arrangement of a random copolymer, a block copolymer, a tapered copolymer, etc. And any of linear and radial polymer chain shapes. Among these, it contains at least one polymer block of a monomer mainly composed of isobutylene and at least one polymer block of a monomer mainly composed of a styrene-based compound, and at least one polymer block contains β- A block copolymer in which pinene is copolymerized is preferred because the modified copolymer after graft modification tends to have particularly good miscibility with other synthetic resins. As a typical example of the block arrangement of such a block copolymer, when the polymer block of the monomer mainly composed of isobutylene is represented by I, and the polymer block of the monomer mainly composed of the styrene-based compound is represented by S, Are included.

[0023]

Embedded image SI (Linear Block Copolymer) SIS (Linear Block Copolymer) ISI (Linear Block Copolymer) ISIS (Linear Block Copolymer) Block copolymer) I (-S) n (radial block copolymer (n represents an integer of 3 or more))

The number average molecular weight of the addition copolymer is not necessarily limited, but is preferably in the range of 2,000 to 1,000,000. When the number average molecular weight of the addition copolymer is 2,000 or more, when the modified copolymer after graft modification is mixed with another resin to produce a resin composition, bleed out from the resin composition is reduced. It is easy to be suppressed. Note that the addition copolymer contains at least one polymer block of a monomer mainly composed of isobutylene and at least one polymer block of a monomer mainly composed of a styrene-based compound, and in at least one polymer block. When β-pinene is a block copolymer copolymerized, the number average molecular weight of the polymer block of a monomer mainly composed of isobutylene and the polymer block of a monomer mainly composed of a styrene compound is 5,000, respectively. It is preferably in the range of ２００200,000 and in the range of 1,000０〜200,000, and the weight of the polymer block of the monomer mainly composed of isobutylene (total weight contained in one molecule of the addition copolymer) and the styrene compound Weight of polymer block of monomer mainly composed of (addition copolymer The ratio of the total weight) contained in a molecule is preferably in the range of 20 / 80-95 / 5 in the former / the latter.

In the addition copolymerization of the above monomers (isobutylene as a main monomer, β-pinene as an essential comonomer, and other comonomers used as required), a group represented by the above general formula (1) is used. Use of an initiator system composed of an organic compound containing at least one compound in a molecule and a Lewis acid suppresses side reactions other than the desired addition copolymerization (β-pinene involves an isomerization reaction). The monomer used for this is efficiently addition-copolymerized (therefore, the addition copolymer obtained by controlling the timing of introducing β-pinene into the polymerization reaction system and the ratio of β-pinene used based on all monomers) is obtained. The position and amount of introduction of the radical reactive site derived from β-pinene can be highly controlled, and an addition copolymer having a narrow molecular weight distribution can be obtained. (Hereinafter, the addition copolymerization using such an initiator system may be referred to as “addition copolymerization (I)”).

In the above formula (1), A ¹ and A ² each represent an alkyl group, an aryl group or an aralkyl group. Examples of the alkyl group include a lower alkyl group such as a methyl group and an ethyl group. Examples of the aryl group include a phenyl group and a tolyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. You. In the general formula (1), X represents an acyloxy group, an alkoxyl group, a hydroxyl group or a halogen atom. Examples of the acyloxy group include lower alkanoyloxy groups such as an acetoxy group and a propionyloxy group.Examples of the alkoxyl group include a methoxyl group and an ethoxyl group.The halogen atom includes a chlorine atom and a bromine atom. Is exemplified. One or two or more groups represented by the general formula (1) are contained in the molecule of the organic compound, and the portion serves as a polymerization initiation point. Therefore, when an organic compound containing one or two groups represented by the general formula (1) is used, a linear addition copolymer can be obtained, and three or more groups are contained. When an organic compound is used, a radial addition copolymer can be obtained.

The organic compound having a group represented by the general formula (1) includes an ether having a tertiary carbon atom bonded to an oxygen atom, and a halogenated hydrocarbon having a tertiary carbon atom bonded to a halogen atom. Tertiary alcohols, esters of tertiary alcohols with carboxylic acids, and the like. Specific examples of the ester of the tertiary alcohol and the carboxylic acid include α-cumyl esters such as 2-acetoxy-2-phenylpropane and 2-propionyloxy-2-phenylpropane. Specific examples of the ether having a tertiary carbon atom bonded to the oxygen atom include α-cumyl ether such as 1,4-bis (1-methoxy-1-methylethyl) benzene. Specific examples of the halogenated hydrocarbon having a tertiary carbon atom bonded to the halogen atom include 2-chloro-2-phenylpropane, 1,4-bis (1-chloro-1-methylethyl) benzene, Α-cumyl chloride such as 1,3,5-tris (1-chloro-1-methylethyl) benzene; 2-chloro-2,4,4-trimethylpentane; 2,6-dichloro-2,4,4,6 -Tetramethylheptane and the like. Specific examples of the above tertiary alcohol include 1,4-bis (1-hydroxy-
1-methylethyl) benzene, 2,6-dihydroxy-
2,4,4,6-tetramethylheptane and the like.

As the above-mentioned Lewis acid, a metal halide is preferably used. Specific examples of the metal halide include boron halide compounds such as boron trichloride, boron trifluoride, and diethyl ether complex of boron trifluoride; halogens such as titanium tetrachloride, titanium tetrabromide, and titanium tetraiodide. Titanium halide compounds; tin halide compounds such as tin tetrachloride, tin tetrabromide and tin tetraiodide; aluminum halide compounds such as aluminum trichloride, alkyldichloroaluminum and dialkylchloroaluminum; antimony pentachloride and antimony pentafluoride Halogenated compounds such as tungsten pentachloride; molybdenum halide compounds such as molybdenum pentachloride; and tantalum halide compounds such as tantalum pentachloride. In addition, a metal alkoxide such as tetraalkoxytitanium can be used as the Lewis acid. The amount of the Lewis acid used is determined by the general formula (1)
Is preferably 1 to 100 times the number of moles of the group represented by the formula.

The number average molecular weight of the obtained addition copolymer is as follows:
It can be controlled by the ratio between the amount of the group represented by the general formula (1) and the amount of all monomers.

The addition copolymerization (I) using the initiator system described above can be carried out in an organic solvent. As the organic solvent, a solvent used for ordinary cationic polymerization can be used, and specifically, a saturated aliphatic hydrocarbon such as hexane, heptane, cyclohexane, and methylcyclohexane; and an aromatic solvent such as benzene, toluene, and xylene Group hydrocarbons; single solvents such as halogenated hydrocarbons such as methyl chloride, ethyl chloride, methylene chloride, ethylene dichloride, and chlorobenzene; and mixed solvents thereof.

In the reaction system of the above addition copolymerization (I),
If necessary, esters such as ethyl acetate; amines such as triethylamine and pyridine; amides such as dimethylacetamide; ethers such as THF (tetrahydrofuran) and dioxane; sulfoxides such as dimethyl sulfoxide; acetone, methyl ethyl ketone and the like. Organic Lewis bases such as ketones can be present.
The amount of the organic Lewis base to be used is such that the number of moles in the range of 0.1 to 100 times the number of moles of the group represented by the general formula (1) contained in the organic compound used is used. preferable.

Further, at the start of the above addition copolymerization (I), the organic compound having the group represented by the above general formula (1), Lewis acid, monomer and other optional components (such as the above organic Lewis base) can be used. The order of addition to the polymerization reaction system is not necessarily limited, but it is preferable to add other compounds before contacting the monomer with the Lewis acid.

The polymerization temperature in the above addition copolymerization (I) is not necessarily limited, but is usually-
It can be appropriately selected from the range of 150 ° C to + 50 ° C. The above addition copolymerization (I) is preferably performed in a solution state in the above organic solvent under a sufficient stirring condition while controlling the temperature. Further, the addition copolymerization (I) is preferably carried out under a condition where the amount of water is small in order to prevent side reactions, and therefore, a substance having a large amount of monomers, organic solvents and the like charged into the polymerization reaction system. Is preferably subjected to a dehydration treatment in advance as necessary.

The above addition copolymer (I) comprises methanol,
It can be stopped by adding a protic compound such as ethanol or water, or increasing the temperature of the polymerization system.

After terminating the above addition copolymerization (I),
Separation and purification of the addition copolymer from the obtained polymerization reaction solution can be carried out according to a method generally employed for cationic polymerization. For example, the obtained reaction mixture is washed with an aqueous liquid such as water or an aqueous alkaline solution to remove additives such as Lewis acids, and then the washed solution is added, for example, to a desired addition copolymer. By reprecipitating in a poor solvent for the coalescence (for example, methanol), the addition copolymer is separated and obtained.

It should be noted that the copolymer contains a polymer block of a monomer mainly composed of isobutylene and a polymer block of a monomer mainly composed of a styrene compound, and at least one polymer block is copolymerized with β-pinene. If the desired block copolymer is desired to be obtained by the above addition copolymerization (I), a polymerization operation of a monomer mainly composed of isobutylene (a polymer block of a monomer mainly composed of isobutylene, (A polymerization operation for forming a styrene-based compound) and a polymerization operation for forming a monomer block mainly composed of a styrene-based compound (a polymerization operation for forming a polymer block of a monomer mainly containing a styrene-based compound). In performing this, β-pinene may be used as a part of the monomer in at least one polymerization operation. In each polymerization operation, it is preferable to sufficiently increase the conversion of the monomer used to substantially complete the polymerization.

The modified copolymer of the present invention is produced by graft-modifying the above addition copolymer with unsaturated carboxylic acids.

Here, the unsaturated carboxylic acids include, for example, unsaturated carboxylic acids, anhydrides, esters thereof,
The imide and the like are included. Examples of unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid and crotonic acid; maleic acid, fumaric acid, itaconic acid, cis-4-cyclohexene-1,2-dicarboxylic acid, endo-cis-
Examples thereof include unsaturated dicarboxylic acids such as bicyclo [2.2.1] -5-heptene-2,3-dicarboxylic acid. Examples of the unsaturated carboxylic anhydride include maleic anhydride. Examples of the unsaturated carboxylate include acrylates such as methyl acrylate and ethyl acrylate. Examples of the unsaturated carboxylic imide include maleimide. Among these unsaturated carboxylic acids, maleic anhydride is particularly preferred.

In the modified copolymer of the present invention, the weight ratio of the graft branch derived from the unsaturated carboxylic acid is preferably in the range of 0.01 to 10% by weight based on the modified copolymer. Is particularly preferred since it has particularly good miscibility and can prevent a decrease in processability and gelation.

Graft modification of the addition copolymer with an unsaturated carboxylic acid is not necessarily limited. For example, according to a known method, in the presence or absence of an organic peroxide, in a molten state, or in a solution state. It is preferable to carry out the reaction under an arbitrary condition, such as under a radical reaction condition. Examples of usable organic peroxides include dicumyl peroxide, di-tert-butyl peroxide, and 2,5.
-Dimethyl-2,5-bis (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-bis (te
rt-butylperoxy) hexyne-3, n-butyl =
4,4-bis (tert-butylperoxy) valerate, 1,1-bis (tert-butylperoxy)-
3,3,5-trimethylcyclohexane and the like,
Suitable ones can be appropriately selected from these. The use amount of the organic peroxide is not particularly limited, but is usually 0.001 to 5% by weight based on the addition copolymer.
Is within the range.

As an example of a preferred graft modification method, the above addition copolymer, unsaturated carboxylic acid and organic peroxide are melt-kneaded at a predetermined ratio in an extruder at a temperature of 150 to 350 ° C. to cause a radical reaction. There is a way. According to this method, it is easy to suppress by-products of undesired components such as gel and deterioration of workability due to a remarkable increase in melt viscosity.

In the graft modification step, a stabilizer can be added as necessary to prevent by-products such as gel. This stabilizer includes phenolic antioxidants,
Known antioxidants such as a phosphorus antioxidant and a sulfur antioxidant can be used alone or in combination.

The modified copolymer thus obtained is
Further, it may be ionized with a monovalent or higher-valent metal ion, and the modified copolymer of the present invention includes such an ionomer.

The modified copolymer of the present invention exhibits a modifying effect such as improvement in toughness, softening, vibration damping property, gas barrier property, etc. by being blended with various synthetic resins or synthetic resin compositions. . In the resin composition comprising the modified copolymer and the synthetic resin of the present invention, the use ratio of the modified copolymer and the synthetic resin is not necessarily limited, but the resin composition has excellent properties derived from the synthetic resin. It is preferable that the weight ratio of the modified copolymer / synthetic resin is in the range of 2/98 to 50/50 in that the weight of the modified copolymer / synthetic resin can be combined with the properties imparted by the modified copolymer. .

The synthetic resin to which the modified copolymer of the present invention can be blended is not particularly limited as long as it is required to improve performance such as improvement in toughness, softening, vibration damping, and gas barrier properties. However, in the case of a synthetic resin having an interaction or reactivity with the modified copolymer, the effect of the modification is particularly remarkable, so that a synthetic resin having a polar group is preferably used. The synthetic resin may be a thermoplastic resin or a thermosetting resin. Preferred thermoplastic polar resins include, for example, functional group-containing polyolefins such as ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer or a salt thereof, and ethylene-glycidyl methacrylate copolymer; nylon-6, nylon −
Polyamides such as 6,6, nylon-6,12 and MXD nylon; polycarbonates; thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate; and thermoplastic polyurethanes. Preferred thermosetting polar resins include, for example, epoxy resins,
Phenol resins, melamine resins and the like can be mentioned. Note that the synthetic resin is not limited to the use of one kind of resin, and two or more kinds of synthetic resins may be used in combination if desired.

The resin composition comprising the modified copolymer of the present invention and a synthetic resin also includes an embodiment in which a part of both forms a reaction product and is contained.

The blending of the modified copolymer of the present invention with a synthetic resin can be carried out according to a known general method. If the synthetic resin is a thermoplastic resin, for example, using a kneading device such as a single-screw extruder, a twin-screw extruder or the like; a kneading device such as a batch-type kneader, and kneading both under heating and melting conditions. Thereby, a resin composition can be produced. Among the above kneading apparatuses, it is particularly preferable to use a twin-screw extruder from the viewpoint of kneading properties, productivity and the like. The temperature during kneading cannot be unconditionally determined because a suitable temperature range depends on the type of the synthetic resin and the like, but is generally equal to or higher than the melting points of the synthetic resin and the modified copolymer,
A temperature that does not cause deterioration of the synthetic resin and the modified copolymer is employed. Specifically, in many cases 1
Preferably within the range of 60 to 320 ° C, 180 to 280 ° C
Is more preferable.

If the synthetic resin is a thermosetting resin, for example, when the thermosetting resin is in a semi-cured state, the modified copolymer is kneaded with a batch kneader or the like, and then heated to obtain a cured resin. A composition can be manufactured. If the resin component before curing is liquid, a method of dissolving the modified copolymer in it, mixing it with a curing agent, and curing at the same time can also be adopted.

An organic additive, an inorganic additive and the like can be added to the resin composition containing the modified copolymer of the present invention as long as the physical properties thereof are not significantly impaired. Examples of additives include higher aliphatic carboxylic acids such as stearic acid and derivatives thereof, process oils, processing aids such as liquid polyisobutylene; mica, carbon black, silica, glass fiber, carbon fiber, calcium carbonate,
Reinforcing agents such as talc; antioxidants; ultraviolet absorbers; pigments and the like. For the purpose of preventing the generation of gel, hydrotalcite compounds, hindered phenols, hindered amine heat stabilizers, phosphite stabilizers, metal salts of higher aliphatic carboxylic acids (for example, calcium stearate, magnesium stearate) Etc.)
In some cases, it may be effective to add one or more species at a ratio of about 0.01 to 1% by weight based on the resin composition. Further, an alkali metal ion such as lithium ion, sodium ion and potassium ion is added to the resin composition in an amount of 1%.
It is also effective to prevent the gel from being generated by containing the compound in a ratio of about 0 to 500 ppm. The alkali metal ion can be contained by adding an alkali metal compound, and examples of the alkali metal compound include an aliphatic carboxylate, an aromatic carboxylate, a phosphate, and a metal complex of an alkali metal. Specific examples include sodium acetate, potassium acetate, sodium phosphate, lithium phosphate, sodium stearate, potassium stearate and the like.

The resin composition comprising the modified copolymer of the present invention and a synthetic resin can be molded by various molding methods employed for the synthetic resin. For example, by a commonly used molding method such as injection molding, extrusion molding, inflation molding, blow molding, vacuum molding and the like, and co-extrusion molding, a molding method for integrally integrating a plurality of resins such as insert molding, a sheet, Molded articles of various shapes such as films and tubes can be obtained.

[0051]

The present invention will be described more specifically with reference to the following examples.

The number average molecular weight (M
n) and Mw (weight average molecular weight) / Mn
(Manufactured by Shimadzu Corporation). The content of the structural unit derived from β-pinene in the resulting modified copolymer was determined by NMR.
(Manufactured by JEOL Ltd.).

The synthetic resins used in the examples are as follows. Polyamide resin (A): Nylon-6 (“U
BE nylon 1013B ") Polybutylene terephthalate (B): Kuraray" Hauser S1000 "Ethylene-vinyl alcohol copolymer (C): Kuraray" EVAL EP-F101 "

The evaluation of the physical properties and the measurement of the average dispersed particle size of the obtained resin composition were performed by the following methods (1) to (5).

(1) Flexibility The flexibility was evaluated by measuring the flexural modulus of the resin composition according to JIS K7116.

(2) Tensile properties The resin composition was used to measure the breaking strength and the breaking elongation according to JIS K7115.

(3) Impact Resistance The notched Izod (Izod) impact strength of the resin composition was measured according to JIS K7110 to evaluate the impact resistance.

(4) Gas Barrier Property A film having a thickness of 200 μm was prepared by compression molding using the resin composition, and the film was measured using a gas permeability measuring device (“GTR-10” manufactured by Yanagimoto Seisakusho). ,
The oxygen permeability coefficient PO ₂ was measured under the conditions of an oxygen pressure of 2.5 kg / cm ² and a temperature of 35 ° C., and this was used as an index of gas barrier properties.

(5) Average dispersed particle diameter The average dispersed particle diameter of the modified copolymer or the copolymer phase dispersed in the synthetic resin matrix phase was determined for each resin composition by the following method. . A sheet having a thickness of 1 mm is produced by compression molding using the resin composition, the sheet is cooled with liquid nitrogen and then broken, and the fragments are immersed in toluene at room temperature for 1 minute to obtain a modified surface portion. After extracting the polymer component (or copolymer component), the crushed surface is photographed at a magnification of 500 to 5000 times with a scanning electron microscope (SEM) (“S-2150” manufactured by Hitachi, Ltd.) and formed by extraction. Any 10 holes
The diameter of the largest inscribed circle was measured for each piece, and the arithmetic average value thereof was taken as the average dispersed particle diameter.

Example 1 A reactor equipped with a stirrer was charged with 800 ml of methylene chloride dehydrated and purified by Molecular Sieves 4A and 1200 ml of methylcyclohexane similarly dehydrated and purified.
2.0 g (8.7 mmol) of 1,4-bis (1-chloro-1-methylethyl) benzene, 0.98 g (9.1 mmol) of 2,6-dimethylpyridine, 1.38 of pyridine
g (17.4 mmol) and 210 g of isobutylene were added, and titanium tetrachloride (12.3) was added at -78 ° C.
The polymerization was started by adding g (65 mmol). After polymerization at −78 ° C. for 3 hours with stirring, 0.5 g (4.7 mmol) of 2,6-dimethylpyridine and styrene 9
By adding 0 g and 23.8 g of β-pinene, polymerization was carried out at the same temperature for 2 hours while stirring. The polymerization reaction was stopped by adding 20 ml of methanol to the obtained reaction mixture. Wash the resulting mixture with water,
Then, by reprecipitation in a large amount of methanol,
A block copolymer having a triblock structure of (styrene-β-pinene copolymer block)-(isobutylene polymer block)-(styrene-β-pinene copolymer block) was obtained. The number average molecular weight of the obtained block copolymer is 37000, Mw / Mn is 1.25,
The content of the structural unit derived from styrene was 27.9% by weight, and the content of the structural unit derived from β-pinene was 6.9% by weight.
Met. The obtained block copolymer, maleic anhydride and organic peroxide ("Perhexa 25" manufactured by NOF Corporation)
B ": 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane) having a weight ratio of block copolymer: maleic anhydride: organic peroxide of 100: 8:
The mixture was premixed with a Henschel mixer at a ratio of 0.2. This premix was supplied to a twin-screw extruder (cylinder temperature: 230 ° C.) and subjected to graft modification under melting conditions to obtain a modified copolymer (1). The grafted amount of maleic anhydride in the obtained modified copolymer was 2.3 parts by weight based on 100 parts by weight of the modified copolymer.

Example 2 A reactor equipped with a stirrer was charged with 800 ml of methylene chloride dehydrated and purified using Molecular Sieves 4A and 1200 ml of methylcyclohexane similarly dehydrated and purified.
1.0 g (4.3 mmol) of 1,4-bis (1-chloro-1-methylethyl) benzene, 1.74 g (9.1 mmol) of 2,6-di-t-butylpyridine, 0.68 g (8 .6 mmol), 210 g of isobutylene
And 6.0 g of β-pinene were added, and -7 was added.
The polymerization was initiated by adding 12.3 g (65 mmol) of titanium tetrachloride at 8 ° C. After polymerization at -78 ° C for 4 hours with stirring, 2,6-di-t-butylpyridine 0.9
g (4.7 mmol) and 90 g of styrene were added to polymerize under stirring at the same temperature for another 4 hours. The polymerization reaction was stopped by adding 20 ml of methanol to the obtained reaction mixture. The resulting mixed solution was washed with water and then reprecipitated in a large amount of methanol to form a (styrene polymer block)-(isobutylene-β-pinene copolymer block)-(styrene polymer block) triblock structure. Was obtained. The number average molecular weight of the obtained block copolymer was 77000, Mw / Mn was 1.24, the content of the structural unit derived from styrene was 29.5% by weight,
The content of the structural unit derived from β-pinene was 1.8% by weight. The obtained block copolymer, maleic anhydride and organic peroxide (“Perhexa 25B” manufactured by NOF Corporation:
2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane) having a weight ratio of block copolymer: maleic anhydride: organic peroxide of 100: 5: 0.15.
Was premixed with a Henschel mixer. This pre-mixture is fed to a twin-screw extruder (cylinder temperature: 2
(30 ° C.), and graft-modified under melting conditions to obtain a modified copolymer (2). The grafted amount of maleic anhydride in the resulting modified copolymer was 0.9 parts by weight based on 100 parts by weight of the modified copolymer.

Example 3 A reactor equipped with a stirrer was charged with 800 ml of methylene chloride dehydrated and purified by Molecular Sieves 4A and 1200 ml of methylcyclohexane dehydrated and purified in the same manner.
2.0 g (8.7 mmol) of 1,4-bis (1-chloro-1-methylethyl) benzene, 0.98 g (9.1 mmol) of 2,6-dimethylpyridine, 1.38 of pyridine
g (17.4 mmol), 210 g of isobutylene and 10.8 g of β-pinene, respectively, and further added at −78 ° C.
The polymerization was started by adding 12.3 g (65 mmol) of titanium tetrachloride, and the polymerization was carried out at −78 ° C. with stirring for 3 hours. 20 m of methanol was added to the obtained reaction mixture.
The polymerization reaction was stopped by adding l. The obtained mixture was washed with water and then reprecipitated in a large amount of methanol to obtain an isobutylene-β-pinene copolymer. The number average molecular weight of the obtained copolymer is 23,000.
Mw / Mn was 1.18, and the content of the structural unit derived from β-pinene was 4.6% by weight. The obtained copolymer, maleic anhydride and organic peroxide (“Perhexa 25B” manufactured by NOF: 2,5-dimethyl-2,5
-Bis (tert-butylperoxy) hexane)
Weight ratio of copolymer: maleic anhydride: organic peroxide is 1
The mixture was premixed with a Henschel mixer at a ratio of 00: 5: 0.2. This premix was supplied to a twin-screw extruder (cylinder temperature: 230 ° C.) and graft-modified under melting conditions to obtain a modified copolymer (3). The grafted amount of maleic anhydride in the obtained modified copolymer was 1.8 parts by weight based on 100 parts by weight of the modified copolymer.

Reference Example 1 In the same manner as in Example 1 except that β-pinene was not added, the operations of polymerization of isobutylene, polymerization of styrene, termination of the polymerization reaction, washing with water, and reprecipitation were sequentially performed to obtain ( A block copolymer (4) having a triblock structure of (styrene polymer block)-(isobutylene polymer block)-(styrene polymer block) was obtained. The number average molecular weight of the obtained block copolymer is 34000, and Mw
/ Mn was 1.23, and the content of the structural unit derived from styrene was 30% by weight.

Reference Example 2 In the same manner as in Example 2 except that β-pinene was not added, the procedures of polymerization of isobutylene, polymerization of styrene, termination of the polymerization reaction, washing with water, and reprecipitation were sequentially performed to obtain ( A block copolymer (5) having a triblock structure of (styrene polymer block)-(isobutylene polymer block)-(styrene polymer block) was obtained. The number average molecular weight of the obtained block copolymer is 75,000, and Mw
/ Mn was 1.20, and the content of the structural unit derived from styrene was 30% by weight.

Examples 4 to 7 and Comparative Example 1 The polyamide resin (A) and the modified copolymers (1) to (3) obtained in the examples and the copolymer (4) obtained in the reference example
One of these was preliminarily mixed at a ratio shown in Table 1 below, and was melt-kneaded at 240 ° C. using a twin-screw extruder to obtain a resin composition. These resin compositions were molded into various test pieces, and physical properties were evaluated. Table 1 shows the obtained evaluation results.

Comparative Example 2 Polyamide resin (A) alone was molded into various test pieces, and physical properties were evaluated. The evaluation results obtained are shown in Table 1 below.

[0067]

[Table 1]

The "Izod impact strength" in Table 1 above was used.
"NB" in the item of No. means that it was not completely broken, and the value of the Izod impact strength value in that case is shown in parentheses as a reference value.

From the data shown in Table 1 above, the modified copolymers (1) to (3) of the present invention obtained in the examples show unmodified non-modified copolymers other than the present invention obtained in the reference examples. It is confirmed that the dispersibility in the polyamide resin is improved as compared with the copolymer (4), and the effect of improving the impact resistance is large. Further, from the data of the flexural modulus and the elongation at break, it is understood that when the modified copolymer of the present invention is used, a resin composition which is more flexible and stretches well can be obtained. In addition, regarding the gas barrier properties, it is confirmed that the use of the modified copolymer of the present invention does not impair the excellent gas barrier properties of the polyamide resin.

Examples 8 to 11 and Comparative Example 3 Polybutylene terephthalate (B) and the modified copolymers (1) to (3) obtained in Examples and the copolymer (5) obtained in Reference Examples One of these was preliminarily mixed at a ratio shown in Table 2 below, and was melt-kneaded at 230 ° C. using a twin-screw extruder to obtain a resin composition. These resin compositions were molded into various test pieces, and physical properties were evaluated. Table 2 shows the obtained evaluation results.

Comparative Example 4 Polybutylene terephthalate (B) alone was molded into various test pieces, and physical properties were evaluated. The obtained evaluation results are shown in Table 2 below.

[0072]

[Table 2]

From the data shown in Table 2 above, the modified copolymers (1) to (3) of the present invention obtained in the examples show the unmodified non-modified copolymers obtained in the reference examples other than the present invention. Compared with the copolymer (5), it is confirmed that the dispersibility in polybutylene terephthalate is improved and the effect of improving impact resistance and flexibility is large.

Examples 12 to 15 and Comparative Example 5 Ethylene-vinyl alcohol copolymer (C), modified copolymers (1) to (3) obtained in Examples and copolymers obtained in Reference Examples (4) was preliminarily mixed with each other at a ratio shown in Table 3 below, and mixed with a twin-screw extruder.
The resin composition was obtained by melt-kneading at 20 ° C.
These resin compositions were molded into various test pieces, and physical properties were evaluated. Table 3 shows the obtained evaluation results.

Comparative Example 6 A single sample of the ethylene-vinyl alcohol copolymer (C) was molded into various test pieces, and physical properties were evaluated. Table 3 below shows the obtained evaluation results.

[0076]

[Table 3]

From the data shown in Table 3 above, the modified copolymers (1) to (3) of the present invention obtained in the examples show the unmodified non-modified copolymers other than the present invention obtained in the reference examples. Compared with the copolymer (4), it is confirmed that the dispersibility in the ethylene-vinyl alcohol copolymer is improved, and the effect of improving impact resistance and flexibility is large. Further, regarding the gas barrier property, it is confirmed that when the modified copolymer of the present invention is used, the excellent gas barrier property of the ethylene-vinyl alcohol copolymer is not significantly impaired.

[0078]

According to the present invention, it has a chemical structure consisting of a trunk formed from a monomer mainly composed of isobutylene and a graft branch formed from unsaturated carboxylic acids, and has a miscibility with various synthetic resins. A modified copolymer which is excellent and has excellent modifying effects such as imparting flexibility and impact resistance is provided. According to the production method of the present invention, the modified copolymer can be easily produced. Further, a resin composition obtained by blending the modified copolymer with a synthetic resin has properties improved in flexibility, impact resistance, etc., while utilizing the excellent properties inherent in the synthetic resin, and has a gas barrier property. Is also good.

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Claims (6)

[Claims] 1. A modified copolymer obtained by graft-modifying an addition copolymer of isobutylene as a main monomer and β-pinene as a comonomer with unsaturated carboxylic acids. 2. The addition copolymer comprises a polymer block of a monomer mainly composed of isobutylene and a polymer block of a monomer mainly composed of a styrene-based compound, and at least one polymer block has a β-block in at least one polymer block. The modified copolymer according to claim 1, which is a block copolymer in which pinene is copolymerized. (A) a general formula: -C (-A ¹ ) (-A ² ) -X (1) (where A ¹ and A ² are an alkyl group, an aryl group or an aralkyl group, respectively) X represents an acyloxy group, an alkoxyl group, a hydroxyl group or a halogen atom.) The main monomer is prepared by using an initiator system comprising an organic compound containing at least one group represented by the following formula: To obtain a copolymer by polymerizing isobutylene is a comonomer β-pinene,
The method for producing a modified copolymer according to claim 1, wherein (b) the copolymer is graft-modified with an unsaturated carboxylic acid. 4. An initiator system comprising (a ') an organic compound containing at least one group represented by the general formula (1) in a molecule and a Lewis acid, and in at least one polymerization operation, Using β-pinene as a part,
By alternately performing the polymerization operation of the monomer mainly composed of isobutylene and the polymerization operation of the monomer mainly composed of the styrene-based compound in a predetermined order and number of times, the polymer block of the monomer mainly composed of isobutylene and the styrene-based compound are converted. A block copolymer containing a polymer block of a monomer as a main component, and in which β-pinene is copolymerized in at least one polymer block,
4. The method according to claim 3, wherein (b ') the block copolymer is graft-modified with an unsaturated carboxylic acid. 5. The method according to claim 3, wherein the graft modification is performed under radical reaction conditions. 6. A resin composition comprising the modified copolymer according to claim 1 and a synthetic resin.