JPH032209A - Styrenic copolymer - Google Patents

Abstract

PURPOSE:To obtain the subject polymer for liquid crystal display, etc., having specific weight-average molecular weight and blue fluorescent color comprising styrenic repeating unit mainly having syndiotactic structure and 9-vinyl anthracene repeating unit. CONSTITUTION:A styrenic monomer expressed by formula I (R is H, halogen or 1-20C hydrocarbon group; m is integer of 1-3) is copolymerized with 9- vinylanthracene expressed by formula II in toluene and in the presence of aluminoxane and cyclopentadienyltitanium trichloride at a temperature of 50 deg.C to afford the aimed copolymer composed of 95-5mol% styrenic repeating unit expressed by formula III and 5-95mol% 9-vinylanthracene repeating unit expressed by formula IV having 5000-1000000 weight-average molecular weight with mainly syndiotactic configulation of stereoregularity of styrenic repeating chain unit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a styrenic copolymer, and more particularly to a copolymer having a specific three-dimensional structure consisting of a styrene yarn repeating unit and a 9-vinylanthracene repeating unit.

[Problems to be solved by conventional techniques and inventions] Recently,
Since display devices are required to be "light, thin, short, and small," flat display devices are attracting attention.
Liquid crystal displays (LCDs) and the like have been widely put into practical use. Since this LCD is a light-receiving type and has extremely low power consumption, it is used for many purposes, but there are problems with display quality, especially contrast and response speed, and there has been a desire to develop a light-emitting type liquid crystal display. Electroluminescent displays (ELDs), which can produce medium-sized and large-capacity light-emitting liquid crystal displays, have been commercialized as a promising type. Furthermore, zinc sulfide is widely used as the host material for the light-emitting layer. The emission color of zinc sulfide covers the main wavelengths of visible light, but only yellow-orange colors have been put into practical use; other colors have low luminance and have not been put into practical use. Especially blue light emission,
Even in subsequent research, no material with sufficient brightness for practical use had been developed, and there was a desire for full-color displays and the development of blue-emitting materials.

By the way, the group of the present inventors succeeded in developing a styrenic polymer with high anticatalytic and syndiotactic properties, and also developed a styrene polymer that was copolymerized with this styrene monomer and other components. (Unexamined Japanese Patent Publication No. 62-1
No. 04818, No. 5, No. 63-241009, etc.).

These syndiotactic polymers and copolymers have excellent heat resistance, chemical resistance, and electrical properties, and are expected to be used in a wide variety of fields.

In view of the above circumstances, the present inventors developed a styrene-based copolymer with high syndiotacticity that is capable of blue light emission and has the characteristics of an organic polymer light emitter that can be used as a film as it is. In order to develop it, we conducted extensive research and consideration.

[Means to solve the problem]

As a result, a new copolymer with a structure in which a styrene monomer and 9-vinylanthracene are copolymerized, and in which the stereoregularity of the styrene repeating unit chain mainly has a syndiotactic structure, has the desired properties. I discovered something. The present invention was completed based on this knowledge.

That is, the present invention provides -maximum CI) [wherein R is a hydrogen atom, a halogen atom, or a carbon number of 2]
It represents 0 or less hydrocarbon groups, and m represents an integer of 1 to 3. In addition, when m is plural, each R may be the same or different. 95 to 5 mol% of styrenic repeating units represented by ] and 5 to 95 9-vinylanthracene repeating units represented by formula (11)
It consists of mol% and has a weight average molecular weight of 5. OOO~1,
000. The present invention provides a styrenic copolymer which is OOO and is characterized in that the stereoregularity of the styrenic repeating unit chain is mainly a syndiotactic structure.

The styrenic copolymer of the present invention has the general formula (1
) and the repeating unit represented by general formula (II), where the repeating unit represented by -maximum (1) is -maximum [bi] [in the formula, R, m is the same as above. ] It is derived from the styrenic monomer represented by.

In the formula, R is a hydrogen atom, a halogen atom (e.g. chlorine bromine,
fluorine, iodine) or a hydrocarbon group having 20 or less carbon atoms, preferably 10 to 1 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group).

Saturated hydrocarbon groups (especially alkyl groups) such as pentyl group and hexyl group, or unsaturated hydrocarbon groups such as vinyl method)
It is. - Specific examples of repeating units represented by maximum (1) include styrene units: p-methylstyrene units;
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; p-tert-butylstyrene unit, etc. alkylstyrene units, p-divinylbenzene units; m-divinylhenzene units, nitrivinylbenzene units; p-chlorostyrene units; m-chlorostyrene units;
0-chlorostyrene unit; p-bromostyrene unit; n
l-bromostyrene unit; 0-bromostyrene unit; p
-fluorostyrene unit; m-fluorostyrene unit:
Examples include 0-fluorostyrene units; halogenated styrene units such as 0-methyl-p-fluorostyrene units, and mixtures of two or more of these units in order to control the wavelength of color development.

On the other hand, the 9-vinylanthracene repeating unit represented by -maximum (II) is derived from 9-vinylanthracene represented by the formula [■''].

A 9-vinylanthracene derivative polymerizable at the 10-position can also be used. Note that this 9-vinylanthracene repeating unit is effective in imparting luminescent properties to the copolymer. Other olefins, dienes, polar vinyl monomers, etc. may be used in combination as long as this luminescence is not impaired.

In the copolymer of the present invention, the styrenic repeating unit may be composed of two or more types of components. Therefore, it may be a binary, ternary or quaternary copolymer. Further, the content of the 9-vinylanthracene repeating unit is 5 to 95 mol%, preferably 10 to 95 mol% of the entire copolymer. Here, 9- in the copolymer
If the content of vinyl anthracene repeating units is less than 5 mol %, sufficient luminescence cannot be exhibited.

Moreover, when it exceeds 95 mol %, film forming properties deteriorate.

Furthermore, the copolymer of the present invention has a weight average molecular weight of 5.0
00-1,000,000, preferably 8.000-s
oo, ooo. If the weight average molecular weight is less than 5,000, the film forming property is poor, and if it exceeds 1,000,000, it becomes difficult to dissolve in the solvent used for film forming.

There is no particular restriction on the molecular weight distribution, and it may be wide or narrow.

In the styrenic copolymer of the present invention, the chain of styrene yarn repeating units mainly has 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. have a three-dimensional structure in which are alternately located in opposite directions (
racemic), and its toughness is determined by nuclear magnetic resonance method ("C-NMR method") using carbon isotope.

``Toughness measured by C-NMR method is
The abundance ratio of a plurality of consecutive constituent units (i.e., the abundance ratio of relative conformational relationships of consecutive constituent units), for example 2
In the case of 3 units, it can be indicated by a diad, in the case of 3 units, it can be indicated by a triat, and in the case of 5 units, it can be indicated by a pentad. However, in the present invention, having a mainly syndiotactic structure means that in a chain of styrenic repeating units, 75% or more, preferably 85% or more for racemic pentad, or 30% or more, preferably 50% for racemic pentad.
Indicates something with the above syndiotactic properties,
However, the degree of syndiotacticity varies slightly depending on the type of substituent and the content ratio of each repeating unit.

The styrenic copolymer of the present invention has various embodiments such as block copolymerization, random copolymerization, and alternating copolymerization of styrenic repeating units and 9-vinylanthracene repeating units, but block copolymers are particularly preferred. preferable.

The copolymer of the present invention can be produced by various methods using the above-mentioned styrenic monomer represented by [bi] and the 9-vinylanthracene monomer represented by formula [■°]. For example, it can be produced by copolymerizing in the presence of a catalyst containing (A) a titanium compound and (B) an alkylaluminoxane as main components.

Regarding the catalyst used in the production of this copolymerization, JP-A-62
This is as described in detail in Japanese Patent No.-187708. Further, a more preferable titanium compound as component (A) is -maximum% formula% [wherein R1 represents a cyclopentagenyl group, a substituted cyclopentagenyl group, or an indenyl group, and X3 Y and Z are each independently hydrogen atom, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, and 6 to 20 carbon atoms
represents an aryl group, 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 R1 in this formula has, for example, 1 to 1 carbon atoms.
A cyclopentadienyl group substituted with one or more alkyl groups in 6, specifically a methylcyclopentadienyl group, 1
, 2-dimethylcyclopentagenyl group, pentamethylcyclopentagenyl 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.) 1 to 1 carbon atoms
2 alkoxy group (specifically methoxy group, ethoxy group, propoxy group, 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 such titanium compounds represented by -maximum - are cyclopentadienyltrimethyltitanium, cyclopentadienyltriethyltitanium, and cyclopentadienyltripropyltitanium.

Cyclopentadienyltributyltitanium, Methylcyclopentagenyltrimethyltitanium, l,2-dimethylcyclopentagenyltrimethyltitanium, Pentamethylcyclopentagenyltrimethyltitanium, Pentamethylcyclopentagenyltriethyltitanium, Pentamethylcyclopentagenyl titanium tripropyl titanium, pentamethylcyclopentagenyl tributyl titanium, cyclopentagenyl methyl titanium dichloride, cyclopentadienyl ethyl titanium dichloride, pentamethyl cyclopentajenyl methyl titanium dichloride, pentamethyl cyclopentadienyl ethyl titanium dichloride, cyclo Pentagenyl dimethyl titanium monochloride, cyclopentajenyl diethyl titanium monochloride, cyclopentajenyl titanium trimethoxide, cyclopentajenyl titanium triethoxide, cyclopentajenyl titanium triethoxide, cyclopentajenyl titanium triethoxide Phenoxide, pentamethylcyclopentadienyl titanium trimethoxide, pentamethylcyclopentadienyl titanium triethoxide, pentamethylcyclopentadienyl titanium tripropoxide, pentamethylcyclopentadienyl titanium tripoxide, pentamethylcyclopentadienyl titanium tripoxide rutitanium triphenoxide, cyclopentagenyl titanium trichloride, pentamethylcyclopentadienyl titanium trichloride, cyclopentajenylmethoxytitanium dichloride, cyclopentajenyldimethoxytitanium chloride, pentamethylcyclopentagenylmethyltitanium dichloride.

Cyclopentadienyltribenzyl titanium, pentamethylcyclopentadienylmethyljethoxytitanium, indenyltitanium trichloride, indenyltitanium trimethoxide, indenyltitanium triethoxide, indenyltrimethyltitanium, indenyltribenzyltitanium, etc. can give.

Among these titanium compounds, compounds containing no halogen atoms are preferred, and in particular, those containing at least one of the above-mentioned titanium atoms are preferred.
A four-coordination type titanium compound in which the ligand is an unsaturated π-electron system ligand is preferred.

On the other hand, alkylaluminoxane, which is the component (B) used together with the titanium compound, is a contact product of an alkylaluminum compound and water, and specifically has the general formula [where n indicates the degree of polymerization and 2 ~50, R2
represents an alkyl group having 1 to 8 carbon atoms. ], or a cyclic alkylaluminoxane having a repeating unit represented by the general formula %.

-a, the contact product of aluminum alkyl, such as trialkylaluminum, and water is a mixture of unreacted trialkylaluminum, various condensation products, as well as the above-mentioned chain alkylaluminoxane and cyclic alkylaluminoxane, and furthermore, are complexly associated molecules,
These products form various products depending on the contact conditions between the 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, (1) a method in which aluminum alkyl is dissolved in an organic solvent and brought into contact with water, (2) a method in which aluminum alkyl is initially added during polymerization and water is added later, and (3) a method in which aluminum alkyl is added initially during polymerization and water is added later. There are methods such as reacting crystallized water contained in salts or water adsorbed on inorganic or organic substances with alkyl aluminum. 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-mentioned contact reaction, if a hydrous compound is used, the solid residue is separated by filtration, and the filtrate is heated at 30 to 200''C under normal pressure or reduced pressure. Temperature, preferably 40°C ~
Preferably, the material is heat-treated at a temperature of 150° C. for 20 minutes to 8 hours, preferably 30 minutes to 5 hours while distilling off the solvent.

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. Generally, 3
At temperatures below 0°C, the effect will not appear, and at temperatures below 200°C.
When the temperature exceeds C, thermal decomposition of the aluminoxane itself occurs,
Undesirable. Depending on the heat treatment conditions, the reaction product may be
Obtained as 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 an alkylaluminoxane is one in which the high magnetic field component in the methyl proton signal region based on the aluminum-methyl group (A/!-CH,) bond observed by proton nuclear magnetic resonance absorption is 50% or less. It is. That is, when the proton nuclear magnetic resonance ('H-NMR) spectrum of the above contact product is observed in toluene solvent at room temperature, 80 groups are found on CH3 (the methyl proton signal is tetramethylsilane (TMS)! It is found in the range of 1.0 to -〇, 5 ppo+ in the standard.T
MS proton signal (0ρps) is Aff-CH
, this Al
The methyl proton signal based on -CH2 was changed to the methyl proton signal of toluene at 2.35p in TMS standard.
pem as a reference, and high magnetic field components (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 the (B) component of the catalyst.

The catalyst used for producing the copolymer of the present invention includes the above (A),
The main component is component (B), and in addition to the above, other catalyst components may be added if desired, such as -Shipin% [In the formula, R3 represents an alkyl group having 1 to 8 carbon atoms. ] It is also possible to add a trialkylaluminum represented by the formula or other organometallic compounds.

When using this catalyst, the ratio of component (A) and component (B) in the catalyst should be determined depending on the type of each component, the type of styrenic monomer represented by the general formula [VI] as a raw material, and other conditions. The ratio of aluminum in component (B) to titanium in component (A), that is, aluminum/titanium (molar ratio), is usually 1 to 106, preferably 10 to 10 'is.

For example, the copolymer of the present invention can be produced by combining the styrene monomer represented by the general formula [1゛] with the formula [■' It is obtained by copolymerizing 9-vinylanthracene represented by ], but this copolymerization can be carried out by various methods such as bulk polymerization, solution polymerization, or suspension polymerization. Solvents that can be used for copolymerization include pentane and hexane.

These include aliphatic hydrocarbons such as heptane, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene.

In addition, the polymerization temperature is not particularly limited, but is usually O~100
°C, preferably 10 to 70 °C. The polymerization time is 5 minutes to 24 hours, preferably 1 hour or more.

As described above, the copolymer of the present invention can be obtained by copolymerizing monomers corresponding to a styrene repeating unit and a 9-vinylanthracene repeating unit. Further, by using the obtained copolymer as a raw material and applying fractionation, blending, or organic synthesis techniques, it is possible to produce a copolymer having a desired stereoregularity and blue-emitting performance.

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 as described above has a high syndiotacticity of the styrene thread repeating unit chain, but after polymerization, if necessary, it is deashed with a washing solution containing hydrochloric acid, etc. Washing.

After drying under reduced pressure and washing with a solvent such as methyl ethyl ketone to remove soluble components, a styrenic copolymer with extremely high syndiotacticity and high purity can be obtained.

〔Example〕

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

Example 1 (1) Preparation of methylaluminoxane Toluene 20QiJ copper sulfate pentahydrate (CuSO4'5 HtO
) 17.7 g (71 mmol) and trimethylaluminum 24d (250 mmol) and heated to 40°C.
The mixture was allowed to react 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, when observing the high magnetic field component from the above-mentioned 'H-NMR measurement, that is, the proton nuclear magnetic resonance spectrum in toluene solution at room temperature, the methyl proton signal based on the (Al-CH:I) bond is It is found in the range of 1.0 to -〇, 5ρplI+ based on silane. The proton signal of tetramethylsilane is (Op
pm) is in the observation region based on the methyl proton based on the AI CH3 bond, so the methyl proton signal based on this /l-CH3 bond is compared to the methyl proton signal of toluene based on tetramethylsilane, 2.35p.
The measurement is based on pm, and the high field component (i.e. -0,
1 to -0,5 ppm) and other magnetic field components (i.e. 1.0
~-0.1 ppm), the high-field component accounted for 43% of the total.

(2) Production of styrenic copolymer 8 mmol of the aluminoxane obtained in the above (1) as aluminum atoms was placed in a dry reaction vessel at room temperature under a nitrogen atmosphere, and after stirring, cyclopentadienyl titanium trichloride was added. After adding 0.01 mmol and raising the temperature to 50°C with further stirring, 9-vinylanthracene (Aldrich
A mixed Tsummer solution containing 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g dissolved in 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g dissolved in 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g of 10.0 g dissolved therein was added to the mixture, followed by a polymerization reaction for 4 hours.

Thereafter, about 10M1 of methanol was added to stop the polymerization. Furthermore, it was washed with a mixed solution of methanol and hydrochloric acid, filtered, and then washed with methanol three times. Thereafter, Soxhlet extraction was carried out with methyl ethyl ketone to remove the 7-mer, followed by drying to obtain 4.5 g of a polymer as an extraction residue.

When the molecular weight of this polymer was measured by gel permeation chromatography, the weight average molecular weight was 1.
2,000, and the number average molecular weight was 3.500.

(3) Polymer analysis and physical property measurements (a) Melting point: When the melting point of the polymer obtained in (2) above was measured using a differential scanning calorimeter, peaks at 240'C and 25B'C were observed. were observed, and a styrene chain with a syndiotactic structure and 9. It is presumed that it contains an IO-bonded anthracene chain.

(b) Ultraviolet absorption spectrum (UV): “The polymer obtained in (2) above, the vinylanthracene homopolymer obtained by the same operation as in (2) above (however, without using styrene), and the When the syndiotactic polystyrene obtained by the method described in 1982-104818 was dissolved in chloroform and the ultraviolet absorption spectrum was observed, only the polymer obtained in (2) above had a characteristic wavelength of 246 nm. There is a strong absorption, suggesting that it is a copolymer.

(c) Proton nuclear magnetic resonance ('H-NMR): above (2)
) was dissolved in deuterated chloroform and 'H-
NMR was measured. The results are shown in FIG. The signal in FIG. 1 can be attributed to 3 to 1 g protons as shown below, and it was found that the 9.10-bonded anthracene chain contained 67 mol%.

1.3ppa+: a, 1.85ppm
: b.

6, 9-1. 5 ppta: c,
2.7pp punishment-; d5.9~6.0pprs
: e, 6.9-7.3ppn : r3.95p
pm:g where a-g correspond to the following protons, respectively.

(d) Nuclear magnetic resonance with carbon isotope (13cm NMR)
: In order to obtain information on the stereoregularity of the styrene chains in this polymer, the aromatic CI carbon signal of styrene was examined by C-NMR, and as shown in Figure 2, it was 135.2.
A sharp signal was observed at ppm, indicating that it had a syndiotactic structure. This styrene aromatic C3 carbon signal is less affected by copolymer bonds than in syndiotactic styrene homopolymer, so it can be assumed that it is a block copolymer.

From the measurement results of (a) to (d) above, the styrene chains of this polymer have a syndiotactic structure, and 9. It was found that it contains an anthracene chain with 1O bond.

(e) Fluorescence spectrum: In order to obtain information on the emission color of the chloroform solution and solvent cast film of this polymer (copolymer) and the vinyl anthracene monomer, the fluorescence spectrum was measured.

The results are shown in FIGS. 3, 4, and 5, respectively.

The film-forming properties of this copolymer were extremely good, and it was possible to form a film by both the usual solvent casting method and the spin-coding method. Comparing their respective fluorescence spectra, it was found that while the monomer vinylanthracene has a fluorescent color in the ultraviolet to purple range, both the chloroform solution of this copolymer and the cast film exhibit indigo to blue-green fluorescence.

〔Effect of the invention〕

The copolymer of the styrene monomer and 9-vinylanthracene having a syndiotactic structure of the present invention has a blue fluorescent color related to blue light emission, can be easily formed into a film, and has a high film formability. It is a polymer. Therefore, the copolymer of the present invention can be effectively used in electroluminescent full color display devices and the like.

[Brief explanation of the drawing]

Figure 1 shows the 'H-NMR spectrum of the copolymer obtained in the example, and Figure 2 shows its 'C-NMR spectrum. Fluorescence spectra of chloroform solution and solvent cast film of polymer and vinylanthracene monomer. (ppm)

Claims (2)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] [In the formula, R is a hydrogen atom, a halogen atom, or a carbon number of 2
It represents 0 or less hydrocarbon groups, and m represents an integer of 1 to 3. In addition, when m is plural, each R may be the same or different. ] 95 to 5 mol% of styrenic repeating units represented by the formula [II] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼... [II] 5 to 95 9-vinylanthracene repeating units represented by the formula [II]
Consisting of mol% and weight average molecular weight of 5,000 to 1,0
00,000, and the stereoregularity of the styrenic repeating unit chain is mainly a syndiotactic structure. (2) The styrenic copolymer according to claim 1, which has blue luminescence.