JPH02258810A - Styrene-based copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer, having a specific steric structure and excellent in heat, chemical resistance, compatibility, etc., by copolymerizing a styrene-based monomer with an unsaturated carboxylic acid (ester)-based monomer in the presence of a Ti compound-alkylaluminoxane-based catalyst. CONSTITUTION:A styrene-based monomer expressed by formula I (R<1> is H, halogen or <=20C hydrocarbon; m is 1-3) and an unsaturated carboxylic acid or an ester-based monomer thereof expressed by formula II (R<2> is H or <=5C saturated hydrocarbon; R<3> is H, <=20C saturated hydrocarbon, benzyl, phenyl, etc.) are copolymerized in the presence of a catalyst consisting of a titanium compound and an alkylaluminoxane to afford the objective copolymer, consisting of styrene-based recurring units expressed by formula III and recurring units of the unsaturated carboxylic acids expressed by formula IV, containing 0.1-50wt.% latter and having 0.07-20dl/g intrinsic viscosity measured in 1,2,4- trichlorobenzene at 135 deg.C and the styrene-based recurring units of mainly a syndiotactic structure.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a styrenic copolymer and a method for producing the same.
Specifically, the present invention relates to a copolymer having a specific steric structure consisting of a styrene monomer and an unsaturated carboxylic acid or an ester monomer thereof, and an efficient method for producing the copolymer.

[Prior Art and Problems to be Solved by the Invention] Styrenic polymers conventionally produced by radical polymerization and the like have an acute three-dimensional structure, and can be processed by various molding methods, such as injection molding, It is molded into various shapes by extrusion molding, blow molding, vacuum forming, injection molding and other methods, and is used for household appliances, office equipment, household goods, and packaging containers.

It is widely used as toys, furniture, synthetic paper, and other industrial materials.

However, such styrenic polymers having an active structure have a drawback of being inferior in heat resistance and chemical resistance.

By the way, the group of the present inventors recently succeeded in developing a styrenic polymer with high syndiotacticity, and also developed a styrenic polymer obtained by copolymerizing this styrene monomer with other components. (Unexamined Japanese Patent Publication No. 62-1
Publication No. 04818.

Publication No. 63-241009). These syndiotactic polymers or copolymers have excellent heat resistance, chemical resistance, and electrical properties, and are expected to be used in a wide variety of fields.

However, the above polymer, especially syndiotactic polystyrene, is a polymer with a glass transition temperature of 90 to 100°C and a melting point of 250 to 275°C, and the heat distortion temperature under low load is at a high level near the melting point, but The thermal deformation temperature under load is around the glass transition temperature, which is almost the same as that of conventional general-purpose polystyrene (GPPS). .

Although it was proposed to combine it with inorganic fillers, etc., there was still room for improvement in the adhesion and compatibility of their interfaces.

Therefore, the present inventors aimed to improve the glass transition temperature, that is, the heat distortion temperature under high loads, while maintaining the heat resistance and chemical resistance of syndiotactic polystyrene, and to improve the compatibility with other resins and inorganic fillers. We have carried out extensive research in order to develop a copolymer with improved compatibility, adhesion, and wettability, as well as an efficient method for producing the copolymer.

[Means to solve the problem]

As a result, when a styrenic motumer and an unsaturated carboxylic acid or its ester monomer are copolymerized in the presence of a specific catalyst, the unsaturated carboxylic acid or its ester component co-polymerizes in the styrenic repeating unit chain of the syndiotactic structure. A copolymer with a polymerized structure is formed, and this copolymer is heat resistant.

The present invention is based on these findings, as it has been found that it has excellent chemical resistance, has a high heat deformation temperature under high loads, exhibits good wettability, and can achieve the desired modification. It is completed.

That is, the present invention provides -large quantity (1) In the formula, R' represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 20 or less carbon atoms, and m represents an integer of 1 to 3. In addition, when m is plural, each R' may be the same or different. ] The styrenic repeating unit represented by and -amount (II) 1←CH, -C÷ ・ ・ ・ (
II) C=0 OR' [In the formula, R2 represents a hydrogen atom or a saturated hydrocarbon group having 5 or less carbon atoms, and R3 represents a hydrogen atom, a saturated hydrocarbon group having 20 or less carbon atoms, or one or more hydroxyl groups. carbon number 20
saturated hydrocarbon group, benzyl group, substituted benzyl group, phenyl group, or substituted phenyl group. ] Consisting of an unsaturated carboxylic acid or its ester repeating unit represented by the formula, containing 0.1 to 50% by weight of the unsaturated carboxylic acid or its ester repeating unit, and containing 1,2,4-trichlorobenzene at 135°C Provided is a styrenic copolymer having an intrinsic viscosity of 0.07 to 20 a/g as measured in a styrenic copolymer, and characterized in that the stereoregularity of the styrene repeating unit chain is mainly a syndiotactic structure, General formula [B] [In the formula, R'+m is the same as above. ] The styrene thread tension and the large quantity [■°] C; O R3 [wherein R2 and R3 are the same as above. This invention provides a method for producing the above-mentioned styrenic copolymer, which comprises copolymerizing an unsaturated carboxylic acid represented by the formula or an ester monomer thereof in the presence of a catalyst consisting of a titanium compound and an alkylaluminoxane. .

The styrenic copolymer of the present invention has the general formula (1
) and the repeating unit represented by the general formula (II), where the repeating unit represented by the -amount (1) is the styrene yarn represented by the above general formula (I"). In the formula 0 derived from Zummer, R1 is a hydrogen atom, a halogen atom (e.g. chlorine, bromine, fluorine, iodine) or a carbon number of 20 or less, preferably 10 to 10 carbon atoms.
One hydrocarbon group (for example, a saturated hydrocarbon group (especially an alkyl group) such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or an unsaturated hydrocarbon group such as a vinyl group). -Specific examples of repeating units represented by large amount (1) include: styrene unit; p-methylstyrene unit; m-methylstyrene unit; 0-methylstyrene unit; 2.4-dimethylstyrene unit; 2.5
-dimethylstyrene unit; 3,4-dimethylstyrene unit; 3,5-dimethylstyrene unit; p-ethylstyrene unit; m-ethylstyrene unit; alkylstyrene unit such as p-tert-butylstyrene unit, p-divinylbenzene Unit; m-divinylbenzene unit; trivinylbenzene unit; p-chlorostyrene unit: m-chlorostyrene unit; 0-chlorostyrene unit; p-bromostyrene unit; m-bromostyrene unit: 0-bromostyrene unit; p -fluorostyrene units; m-fluorostyrene units; 0-fluorostyrene units;

Examples include halogenated styrene units such as -methyl-p-fluorostyrene units, and mixtures of two or more of these units.

On the other hand, the repeating unit represented by the large amount (II) is derived from the unsaturated carboxylic acid or its ester monomer represented by the large amount [■゛].

Specific examples of unsaturated carboxylic acids or their ester monomers include acrylic acid, methyl acrylate,
Acrylic acid alkyl esters such as ethyl acrylate, n-butyl acrylate, isobutyl acrylate, secondary butyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, 2-hydroxyethyl acrylate, etc. There are acrylic acid hydroxyl group-containing alkyl esters, phenyl acrylate, benzyl acrylate, etc., and methacrylic acid or methacrylic esters corresponding to the above-mentioned acrylic esters.

In the copolymer of the present invention, the repeating unit (N may be composed of two or more types of components, and the same applies to the repeating unit (II) in this respect. Therefore, binary, ternary or It becomes possible to synthesize a quaternary copolymer.Also, the content of the above-mentioned repeating unit (IF) is usually 0.1 to 50%, preferably 1%, based on the total copolymer.
．． It ranges from 0 to 20% by weight. This repeating unit (II
) is less than 0.1% by weight, the improvement effects aimed at by the present invention such as improvement in glass transition temperature and heat distortion temperature cannot be sufficiently achieved, and if it exceeds 50% by weight, crystallization may occur. This impairs chemical resistance, which is a characteristic of styrenic polymers with a syndiotactic structure, and tends to cause discoloration (burning) during molding. Defects in physical properties appear.

The molecular weight of this copolymer is generally such that the intrinsic viscosity measured in a 1.2.4-trichlorobenzene solution (temperature 135°C) is 0.07 to 20 dl/g, preferably 0.
．． 3 to 10 a/g. Intrinsic viscosity is 0.01d
If the intrinsic viscosity is less than 1/g, the mechanical properties are so low that it cannot be put to practical use. If the intrinsic viscosity exceeds 20 dl/g, normal melt molding becomes difficult.

In the present invention, a third component may be added to the extent that it does not significantly impair the properties of the resulting copolymer or the syndiotactic structure in the chain of repeating units CI). Examples of such compounds include dienes and vinylsiloxanes.

Examples include α-olefins and acrylonitrile.

The styrenic copolymer of the present invention has a repeating unit [■], that is, a chain of styrene repeating units mainly having a syndiotactic structure.

Here, the mainly syndiotactic structure in styrenic polymers means that the stereochemical structure is mainly syndiotactic, that is, phenyl groups or substituted phenyl groups that are side chains with respect to the main chain formed from carbon-carbon bonds. It has a three-dimensional structure in which the carbon atoms are alternately located in opposite directions, and its toughness can be determined by nuclear magnetic resonance method using carbon isotopes (
IfCNMR method). Toughness measured by the C-NMR method is expressed by the proportion of consecutive constituent units, e.g. 2 in the case of diats, 3 in the case of triats, and 5 in the case of pentads. However, the styrenic copolymer mainly having a syndiotactic structure referred to in the present invention is
In a chain of styrenic repeating units, it usually has syndiotacticity of 75% or more for diad, preferably 85% or more, or 30% or more for pentad (racemic pentad), preferably 50% or more. . However, the types of substituents and repeating units [■]
The degree of syndiotacticity varies slightly depending on the content ratio of .

The copolymer of the present invention as described above has repeating units (1), (
[By copolymerization of monomers corresponding to 3, the resulting copolymer is used as a raw material and fractionated.

By applying blending or organic synthetic techniques, embodiments with the desired stereoregularity and reactive substituents can be produced.

Among them, according to the production method of the present invention described above, a styrenic copolymer of high quality and high layer efficiency can be obtained.

The raw material monomers used in the production method of the present invention include the styrenic monomer represented by the above-mentioned -amount [VI] and the -amount [■]
'] is an unsaturated carboxylic acid or its ester monomer. The styrene monomer and the unsaturated carboxylic acid or its ester monomer copolymerize to form repeating units (1) and (n), respectively. Therefore, specific examples of the styrene monomer and unsaturated carboxylic acid or its ester monomer are:
Examples corresponding to the above-mentioned repeating unit (13, (ff)) can be cited.

In the method of the present invention, these styrene monomers and unsaturated carboxylic acids or ester monomers thereof are used as raw materials and copolymerized in the presence of a catalyst whose main components are (A) a titanium compound and (B) an alkylaluminoxane. However, regarding the catalyst used here,
It is as described in detail in the publication No. 3-241009. First, there are various types of titanium compounds as component (A), but preferably - amount % formula % ()C formula, R', R5, R- and R7 are each hydrogen 5
Alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms, alkylaryl group, arylalkyl group, acyloxy group having 1 to 20 carbon atoms, cyclopentadienyl group, 1lEf-substituted cyclopentadienyl group, indenyl group, or halogen, a, b, and c each represent an integer of O to 4, and d and e each represent an integer of 0 to 3.] A titanium compound represented by It is at least one compound selected from the group consisting of titanium chelate compounds.

R'lR'IR6 and R7 in this large amount (α) or (β) are each a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (specifically, a methyl group, an ethyl group, a propyl group, a butyl group, amyl group, isoamyl group, isobutyl group, octyl group, 2-ethylhexyl group, etc.), carbon number 1-20
alkoxy group (specifically methoxy group, ethoxy group,
propoxy group, butoxy group, amyloxy group, hexyloxy group, 2-ethylhexyloxy group, etc.), aryloxy group having 6 to 20 carbon atoms (phenoxy group, etc.), aryl group having 6 to 20 carbon atoms, alkylaryl group, An arylalkyl group (specifically, a phenyl group, tolyl group, xylyl group, benzyl group, etc.), an acyloxy group having 1 to 20 carbon atoms (specifically, a heptadecylcarbonyloxy group, etc.), a cyclopentadienyl group,! substituted cyclopentadienyl group (specifically, methylcyclopentadienyl group).

1 + 2-dimethylcyclopentadienyl group, pentamethylcyclopentadienyl group, etc.), indenyl group,
These Ba, Rs, R& and R7 representing halogen (chlorine, bromine, iodine or fluorine) may be the same or different.

Further, a, b, and c each represent an integer of 0 to 4, and d and e each represent an integer of O40.

More preferably, the general formula % formula % () [wherein R represents a cyclopentadienyl group, a substituted cyclopentajenyl group, or an indenyl group, and X, Y and 2 each independently represent a hydrogen atom or a carbon number represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, or a halogen atom; ] It is a titanium compound represented by The substituted cyclopentadienyl group represented by R in this formula has, for example, 1 to 1 carbon atoms.
cyclopentadienyl group substituted with one or more alkyl groups in 6, specifically methylcyclopentadienyl i, 1
．． These include 2-dimethylcyclopentadienyl group, pentamethylcyclobentadienyl group, and the like. Also, X, Y and Z
Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (specifically, a methyl group, an ethyl group, and a propyl group).

n-butyl group, isobutyl group, amyl group, isoamyl group, octyl group, 2-ethylhexyl group, etc.).

An alkoxy group having 1 to 12 carbon atoms (specifically, a methoxy group, an ethoxy group, a propoxy group, a butoxy group).

amyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, etc.), aryl group having 6 to 20 carbon atoms (specifically, phenyl group).

naphthyl group, etc.), aryloxy group having 6 to 20 carbon atoms (
Specifically, a phenoxy group, etc.), an arylalkyl group having 6 to 20 carbon atoms (specifically, a benzyl group), or a halogen atom (specifically, chlorine or bromine).

iodine or fluorine).

Specific examples of titanium compounds represented by such a large amount (γ) include cyclopentadienyltrimethyltitanium, cyclopentadienyltriethyltitanium, cyclopentadienyltriprobyltitanium, and cyclopentadienyltributyltitanium.

Methylcyclopentadienyltrimethyltitanium.

1.2-dimethylcyclopentagenyltrimethyltitanium, pentamethylcyclopentagenyltrimethyltitanium, pentamethylcyclopentagenyltriethyltitanium, pentamethylcyclopentagenyltriethyltitanium, pentamethylcyclopentagenyltributyltitanium, cyclopenta Genyl methyl titanium dichloride, cyclopentajenyl ethyl titanium dichloride, pentamethyl cyclopentajenyl methyl titanium dichloride, pentamethyl cyclopentajenyl ethyl titanium dichloride, cyclopentajenyl dimethyl titanium monochloride, cyclopentajenyl diethyl titanium monochloride chloride,
Cyclopentadienyl titanium trimethoxide, cyclopentadienyl titanium triethoxide, cyclopentajenyl titanium triethoxide, cyclopentajenyl titanium triphenoxide, pentamethylcyclopentadienyl titanium trimethoxide, pentamethylcyclopenta pentamethylcyclopentadienyl titanium triethoxide, pentamethylcyclopentadienyl titanium tribroboxide, pentamethylcyclopentadienyl titanium tributoxide, 3pentamethylcyclopentadienyl titanium triphenoxide, cyclopentadienyl titanium trichloride, pentamethylcyclo Pentagenyl titanium trichloride, cyclopentadienyl methyl titanium dichloride, cyclopentadienyl dimethoxy titanium chloride, pentamethyl cyclopentajenyl methoxy titanium dichloride, cyclopentadienyl tribenzyl titanium pentamethyl cyclopentadienyl methyl jetoxy Titanium, indenyl titanium trichloride.

Examples include indenyl titanium trimethoxide, indenyl titanium triethoxide, indenyl trimethyl titanium, and indenyl tribenzyl titanium.

Among these titanium compounds, compounds containing no halogen atoms are preferred, and titanium compounds having one π-electron system ligand as described above are particularly preferred.

On the other hand, alkylaluminoxane, which is the component (B) used together with the titanium compound, is a reaction product of an alkylaluminum compound and water, and specifically has the general formula % (%) [where n is the degree of polymerization] , is a number from 2 to 50, and R1
represents an alkyl group having 1 to 8 carbon atoms. ], or a cyclic alkylaluminoxane having a repeating unit represented by the general formula %.

Generally, the contact product of alkylaluminoxane such as trialkylaluminum and water is, together with the above-mentioned linear alkylaluminoxane and cyclic alkylaluminoxane,
Unreacted trialkylaluminum, a mixture of various condensation products, and even complexly associated molecules of these are formed into various products depending on the conditions of contact between trialkylaluminium and water.

The reaction between the alkyl aluminum and water at this time is not particularly limited, and the reaction may be carried out according to a known method. For example, ■dissolve aluminum alkyl in an organic solvent,
A method of bringing this into contact with water, ■ A method of adding alkyl aluminum initially during polymerization and adding water later, and ■ A method of adding crystal water contained in metal salts, water adsorbed to inorganic substances and organic substances to alkylaluminium. There are methods such as reacting with In addition, the above water contains ammonia.

It may contain up to about 20% of amines such as ethylamine, sulfur compounds such as hydrogen sulfide, phosphorus compounds such as phosphorous esters, and the like.

As for the alkylaluminoxane used as the component (B), after the above contact reaction, if a hydrous compound is used, the solid residue is filtered off, and the filtrate is heated at 30 to 200°C under normal pressure or reduced pressure. Temperature, preferably 40°C to 1
20 minutes to 8 hours at a temperature of 50°C, preferably 30 minutes to
Preferably, the material is heat-treated while distilling off the solvent for 5 hours. In this heat treatment, the temperature may be determined as appropriate depending on various circumstances, but it is usually carried out within the above range. - In general, the effect does not appear at temperatures below 30°C, and
If the temperature exceeds 0°C, thermal decomposition of the aluminoxane itself occurs, which is not preferable. Depending on the heat treatment conditions, the reaction product can be obtained in the form of a colorless solid or solution. The product thus obtained can be used as a catalyst solution by dissolving or diluting it with a hydrocarbon solvent, if necessary.

A suitable example of such a t4 alkylaluminoxane is one in which the high magnetic field component in the methyl proton signal region based on the aluminum-methyl group (An!-CH,) bond observed by proton nuclear magnetic resonance absorption method is 50% or less. be. In other words, when observing the proton nuclear magnetic resonance ('H-NMR) spectrum of the above contact product in a toluene solvent at room temperature, the methyl proton signal based on AI CHs is 1 on the basis of tetramethylsilane (TMS). It is found in the range of .0 to -〇, 5 ppta.

The TMS proton signal (Oppm) is An-CH,
Because it is in the methyl proton observation region based on A/!
The methyl proton signal based on -CH3 is converted to the methyl proton signal of toluene at 2.35p in the 7MS standard.
The measurement is based on pm+, and the high magnetic field component (i.e. -〇,
1 to -0.5 ppm) and other magnetic field components (i.e. 1.0 to -0.5 ppm)
-0.1 ppm) in which the high-field component accounts for 50% or less of the total, preferably 45 to 5%, can be suitably used as component (B) of the catalyst of the present invention.

The catalyst used in the method of the present invention has the above-mentioned components (A) and (B) as main components, and in addition to the above-mentioned components, other catalyst components may be added if desired, such as - Aj! In the R'sC formula, R
9 represents an alkyl group having 1 to 8 carbon atoms. ] Trialkylaluminum or other organometallic compounds can also be added.

When using this catalyst, the ratio of component (A) and component (B) in the catalyst should be determined based on the type of each component, the raw material styrenic monomer represented by the general formula [VI], and the large amount [■ Although it cannot be unambiguously determined depending on the type of unsaturated carboxylic acid or its ester monomer represented by ゛ and other conditions, it is usually the ratio of aluminum in component (B) to titanium in component (A). That is, the aluminum/titanium (mole ratio) is 1 to 10', preferably 10 to 104.

In the method of the present invention, in the presence of a catalyst containing the above-mentioned components (A) and (B) as main components, a styrenic monomer represented by the above general formula [VI] and a styrene monomer represented by the general formula [■゛] An unsaturated carboxylic acid or an ester monomer thereof is copolymerized, and this copolymerization can be carried out by various methods such as bulk polymerization, solution polymerization, or suspension polymerization. Solvents that can be used in copolymerization include aliphatic hydrocarbons such as pentane, hexane, and heptane, alicyclic hydrocarbons such as cyclohexane, and benzene.

These include aromatic hydrocarbons such as toluene and xylene.

In addition, the polymerization temperature is not particularly limited, but is usually θ~100
℃, preferably 10 to 70℃.

The polymerization time is 5 minutes to 24 hours, preferably 1 hour or more.

Furthermore, in order to control the molecular weight of the obtained styrenic copolymer, it is effective to carry out the copolymerization reaction in the presence of hydrogen.

The styrenic copolymer obtained by the method of the present invention is
Syndiotacticity of styrenic repeating unit chains
After polymerization, if necessary, it is deashed with a cleaning solution containing hydrochloric acid, etc., and then washed and dried under reduced pressure, and then washed with a solvent such as methyl ethyl ketone to remove soluble components.
High purity styrenic copolymers with extremely high syndiotacticity can be obtained.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 (1) Preparation of methylaluminoxane 200 d of toluene, sulfuric acid #R5 hydrate (CuSO4.5 H,
O) 11.7 g (71 mmol) and trimethylaluminum 24Id (250 mmol) were added, and 40
The reaction was carried out at ℃ for 8 hours. Thereafter, solid components were removed, and toluene was further distilled off under reduced pressure from the resulting solution to obtain 6.7 g of a contact product. The molecular weight of this product was 610 as measured by freezing point depression method.

In addition, the high magnetic field component from the above-mentioned 'H-N MR measurement,
That is, when its proton nuclear magnetic resonance spectrum is observed in a toluene solution at room temperature, a methyl proton signal based on the (ICHs) bond is seen in the range of 1.0 to -0.5 ppm based on tetramethylsilane.

The proton signal of tetramethylsilane is (Oppm)
But Aj! -C) Since it is in the observation region based on the methyl proton based on the bond, the methyl proton signal based on the AN-CH bond is the methyl proton signal of toluene based on tetramethylsilane, which is 2.35 ppn.
+ as a reference, and high field components (i.e. -0, 1
~-0,5 ppm) and other magnetic field components (i.e. ~-0,5 ppm)
-〇, 1ρps+), the high magnetic field component accounted for 43% of the total.

(2) Production of styrene-methyl methacrylate copolymer 100 styrene was placed in a reaction vessel with an internal volume of 0.52 and equipped with a stirrer.
d and 10.0 mmol of methylaluminoxane obtained in the above (1) as aluminum atoms were added, and the mixture was stirred for 30 minutes at a polymerization temperature of 40°C.

Next, 0.05 mmol of pentamethylcyclopentadienyl titanium trimethoxide was added as a titanium atom, and 100 d of methyl methacrylate was further added. Thereafter, polymerization was carried out at 70° C. for 4 hours with stirring. After completion of the reaction, methanol was injected to stop the reaction. Furthermore, the catalyst component to which a methanol-hydrochloric acid mixture was added was decomposed, and then washing with methanol was repeated three times. The yield of the styrene-methyl methacrylate copolymer obtained here was 4.3 g. Further, the intrinsic viscosity measured in a 1.2.4-trichlorobenzene solution at 135°C was 0.48 dl/g.

Differential scanning calorimetry (DSC) and nuclear magnetic resonance spectroscopy (NMR) revealed that the styrene chain part of this styrene-methyl methacrylate copolymer has a syndiotactic structure.
Prove from the results.

(Measurement by DSC) After thoroughly drying the styrenic copolymer obtained in Example 1, it was placed in a sample container for DSC for 10 days, and the temperature was raised from 50°C to 300°C at a rate of 20°C/min. , 300°C
The temperature was maintained at 300°C for 5 minutes, and the temperature was lowered from 300°C to 50°C at a rate of 20°C/min. The temperature of this sample was raised again from 50"C to 300"C at a rate of 20°C/min, and the heat absorption and heat absorption pattern was observed. The device used was PerkinElmer D.
It is SC-n.

As a result, this copolymer has a glass transition temperature of 110°C1
The melting temperature was 267°C.

Conventional active polystyrene has no melting temperature,
Also, the melting temperature of isotactic polystyrene is 230
°C, the melting temperature of the copolymer does not exceed the higher value of the melting temperatures of the respective homopolymers,
It can be seen that the styrene chain portion of this copolymer has a syndiotactic structure, and that the copolymer is crystalline.

(b) Measurement by C-NMR As a result of measuring the above styrenic copolymer in a 1,2,4-trichlorobenzene solution at 135°C, aromatic signals were observed at 145.1 ppm and 145.9 ppn+. This confirmed that the styrene chain had a syndiotactic structure.The peak based on methyl methacrylate was 22.4 ppm (α-methyl),
45.9 ppm (quaternary carbon).

The content of methyl methacrylate chains in the copolymer was 5.0% by weight. The device used was JEOL Masu FX-20.
It is 0.

(C) Measurement of heat distortion temperature (HDT) The above styrenic copolymer was pelletized using a twin-screw kneader at a cylinder temperature of 300°C. The resulting pellet was injection molded at a cylinder temperature of 300'C to obtain a test piece. This test piece was heat treated at 230°C for 10 minutes. After that, JIS-
When I measured it according to 7207, HDT was 18
．． 5 kg/d is 115°C, and 4,6 kg/c
nl was 215°C. It has been recognized that the HDT of syndiotactic polystyrene is about 100°C, and it can be seen that this was improved by copolymerization.

(d) Measurement of critical surface tension The above styrene copolymer was melted at 300°C to produce a press sheet. When the critical surface tension of this sheet was measured using ethyl benzoate, ethylene glycol, formalin, and water using the droplet shape method, it was found to be 35 dyne/C.
1, 33dyne of syndiotactic polystyrene
/cm.

Critical surface tension is generally considered an indicator of the adhesiveness of a resin, and this copolymer was found to have improved adhesiveness and compatibility.

From the above results, this copolymer is a crystalline styrene-methyl methacrylate copolymer containing styrene chains with a syndiotactic structure, and due to the increase in glass transition temperature,
It was found that the heat distortion temperature under high loads was improved and the adhesion was also improved.

Comparative Examples 1 to 3 and Example 2 Styrene-methyl methacrylate copolymers were obtained in the same manner as in Example 1 using the raw materials, catalysts, and polymerization conditions shown in Table 1 below. The properties of the obtained copolymer are shown in Table 1 together with the results of Example 1.

(Left below) a) Pentamethylcyclopentadienyl titanium trimethoxide b) Tetraethoxytitanium C) Azoisobutyronitrile d) Methylaluminoxane e) Measured at 135°C in 1,2.4-1-lichlorobenzene ) Measurable due to lack of sample [Effects of the Invention] The styrenic copolymer of the present invention has the heat resistance and chemical resistance of syndiotactic polystyrene, has improved glass transition temperature and heat distortion temperature, and has improved compatibility. , adhesion and wettability are significantly improved.

Therefore, the styrenic copolymer of the present invention is useful as various structural materials and compatibilizers. Such a copolymer can be efficiently produced by the method of the present invention.

Procedural amendment (voluntary) March 19, 1990

Claims (4)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] [In the formula, R^1 represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 20 or less carbon atoms, m represents an integer of 1 to 3. Note that when m is plural, each R^1 may be the same or different. ] Styrenic repeating unit and general formula [II] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼...[II] [In the formula, R^2 is a hydrogen atom or a saturated hydrocarbon having 5 or less carbon atoms R^3 represents a hydrogen atom, a saturated hydrocarbon group having 20 or less carbon atoms, a saturated hydrocarbon group having 20 or less carbon atoms having one or more hydroxyl groups, a benzyl group, a substituted benzyl group, a phenyl group, or a substituted Indicates a phenyl group. ] consisting of an unsaturated carboxylic acid or its ester repeating unit represented by the formula, containing 0.1 to 50% by weight of the unsaturated carboxylic acid or its ester repeating unit, and containing 1,2,4-trichlorobenzene at 135°C A styrenic copolymer having an intrinsic viscosity of 0.07 to 20 dl/g as measured in a styrenic copolymer, and having a stereoregularity of a styrene repeating unit chain mainly having a syndiotactic structure. (2) General formula [I'] ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I'] [In the formula, R^1 and m are the same as above. ] Styrenic monomer and general formula [II'] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [II'] [In the formula, R^2 and R^3 are the same as above. Claim 1, characterized in that the unsaturated carboxylic acid or its ester monomer represented by ] is copolymerized in the presence of a catalyst consisting of a titanium compound and an alkylaluminoxane.
A method for producing the styrenic copolymer described above. (3) The titanium compound has the general formula TiRXYZ [wherein R represents a cyclopentadienyl group, a substituted cyclopentadienyl group, or an indenyl group, and X, Y, and Z are each independently a hydrogen atom, a carbon number of 1 to 12 alkyl group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, or a halogen atom. ] The method for producing a styrenic copolymer according to claim 2, which is a titanium compound represented by: (4) Alkylaluminoxane has an aluminum-methyl group (Al-C
H_3) High magnetic field component in the methyl proton signal region based on bond (-0.1 to -0 based on 2.35 ppm of methyl proton in toluene under toluene solvent measurement conditions)
．． 5 ppm) is 50% or less of methylaluminoxane.