JPH01215808A - Syndiotactic polystyrene - Google Patents

Abstract

PURPOSE:To obtain a syndiotactic polystyrene which exhibits a uniform crystalline constitution, by preparing a syndiotactic polystyrene having a specific X-ray diffraction pattern. CONSTITUTION:A syndiotactic polystyrene having a uniform crystalline structure is provided from a syndiotactic polystyrene having such an X-ray diffraction pattern that, when irradiated with an X-ray CuKalpha rays having a wavelength of 0.15418nm, the relative intensities for the diffraction peaks which appear at scattering angles of 2theta=11.8-13.0 deg., 2theta=18.1-19.3 deg. and 2theta=19.6-21.2 deg. are not lower than 20%, 20% and 5%, respectively, and the relative intensities for the diffraction peaks which appear at 2theta=5.5-6.6 deg., 2theta=15.0-16.2 deg. and 2theta=19.6-21.2 deg. are less than 20% and 5%. This polystyrene is produced, for example, by a process which comprises melting a syndiotactic polystyrene having a syndiotacticity of 99% and a number-average molecular weight of 1.0-10<4> or more, and isothermally crystallizing it under 1atm. in an inert gas atmosphere at 240-270 deg.C for 5-3,000hr.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a novel syndiotactic polystyrene.

[Conventional technology]

A syndiotactic polystyrene polymer is obtained by using a condensation product of (A) a titanium compound and (B) an organoaluminum compound with water as a catalyst component in polymerizing styrene (Japanese Patent Publication No. 104818/1982). (Japanese Patent Publication No. 62-187708) FIG. 1 shows an X-ray diffraction chart of the syndiotactic polystyrene illustrated in FIG. 2(a) of Japanese Patent Publication No. 62-104818. According to the X-ray chart, it is understood that known syndiotactic polystyrene has a crystal structure. Syndiotactic polystyrene with a similar crystal structure was published in Macromolecules 1986.1
9+2465-2466.

[Problems to be solved by the invention]

FIG. 2 is an X-ray diffraction pattern of syndiotactic polystyrene synthesized by the present inventors according to the method described in Japanese Patent Publication No. 187708/1983.

This shows that the structure obtained according to Japanese Patent Publication No. 62-187708 has stereoregularity of syndiotactic polystyrene, but its crystal structure contains many amorphous regions.

When a syndiotactic polystyrene structure containing many amorphous regions is recrystallized under a molding process that involves thermal changes such as melting (melting) and cooling, it becomes a non-uniform structure in which multiple crystal structures are mixed. generate.

The present invention provides syndiotactic polystyrene having a crystal structure different from that of known syndiotactic polystyrene and having a uniform crystal structure.

[Means for solving problems]

The present invention uses CuKα rays (wavelengths 0, 15
418 nm), scattering angle 2θ = 11.8 ~ 1
3.0 degrees, 2θ = 18.1 to 19.3 degrees, 2θ = 1
The relative intensity to the diffraction peak appearing at 9.6 to 21.2 degrees has a diffraction peak of 20% or more and 5% or more, respectively, and 2θ=5.5 to 6.6 degrees and 2θ=15.0 to 16.0 degrees. It is a syndiotactic polystyrene having two diffraction peaks whose relative intensities with respect to the diffraction peaks appearing at 2θ=19 and 6 to 21.2 degrees are less than 20% and 5%, respectively. The syndiotactic polystyrene of the present invention can be used as a molded resin material and a resin processed molded product.

The syndiotactic polystyrene structure of the present invention is
It can be produced by the following method using syndiotactic polystyrene prepared by the known polymerization method described in Japanese Patent Publication No. 62-187708 as a raw material. The syndiotacticity and number average molecular weight of the polymer used as raw materials are 99% and 1.
A material having an OX of 10' or more and exhibiting at least useful mechanical properties even in a molded article is selected. Note that the syndiotacticity and number average molecular weight do not substantially change under the following production method.

(1) Melt (melt) the raw material polymer, 1 atm, nitrogen,
240°C ~ 2 in the presence of an inert gas atmosphere such as argon
A method of isothermal crystallization in a temperature range of 70'C for 5 to 3000 hours.

Unless otherwise specified, the values are shown below for a structure obtained under a nitrogen atmosphere at 1 atm.

(2) A method in which a raw material polymer is melted (melted) and then cooled to 200°C at a cooling rate of 1.25°C/min or less under an inert gas atmosphere.

In the above method, by introducing crystal nuclei such as inorganic substances in a melt state and crystallizing them, the crystallization rate can be increased or decreased, the crystallization temperature range can be shifted or expanded,
It is also possible to narrow it down.

In the present invention, the method for measuring the physical properties of syndiotactic polystyrene and the method for identifying the structure are as follows.

1) Stereoregularity and number average molecular weight measurement stereoregularity is determined by Makromol, Chem, 176.3051 (
19T5), the number average molecular weight was determined from the CI carbon spectrum of the benzene ring in the -NMR spectrum (nuclear magnetic resonance spectrum using carbon isotopes), and the number average molecular weight was calculated using gel perminesicon chromatography (1,2,4-) dichloro 130℃ in benzene
(measured by ).

2) Melting point measurement of crystal structure The melting point of the crystal structure was determined from the peak of the chart obtained when the sample was heated at a constant rate (10° C./min) using a differential scanning calorimeter (abbreviated as DSC). The measurement conditions at that time were set as follows.

Apparatus: PerkinElmer 5C-2C Measurement atmosphere: Nitrogen atmosphere (under a flow rate of 20 cc/min) Temperature increase rate during melting chart measurement: 10°C/min Refrigerant of the apparatus:
Ice water 3) Identification method of crystal structure To identify the crystal structure, use the X-ray diffraction method commonly used for crystal structure analysis.

FIG. 3 is a typical X-ray diffraction pattern of the syndiotactic polystyrene structure of the present invention (Example 2).

This structure has a scattering angle 2θ of 5.5 to 6.6 degrees, 11. B
~13.0 degrees, 18.1-19.3 degrees, 19.6-21
．． Diffraction peak 1, peak 2, peak 4, peak 0, and peak 5 are clearly observed at 2 degrees, 34.0 to 36.0 degrees, and diffraction peak 3 is observed at scattering angle 2θ of 15.0 to 16.2 degrees.
The diffraction intensity of is extremely small. In the syndiotactic polystyrene structure of the present invention, almost no diffraction peak is observed at a scattering angle of 15.0 to -0-16.2 degrees, or even if there is a diffraction peak, the diffraction intensity is extremely small.

■ Diffraction intensity reading a, as shown in Figure 3, when the tangent connecting the valley f formed by peaks 0 and 3 and the valley i formed between peaks 0 and 5 is the baseline fi, the scattering angle 2θ= 19,
I is the intensity of the diffraction peak 0 between 5 and 21.3 degrees from the baseline fi. shall be.

b, as shown in Figure 3, the bases a and b on both sides of peak 1
Let us assume that the intensity of peak 1 from baseline ab is 11 when the tangent line connecting these is baseline ab.

C0 As shown in Figure 3, the bases c and d on both sides of peak 2
The intensity of peak 2 from the baseline cd is assumed to be 12, when the tangent line connecting them is the baseline cd.

d, as shown in Figure 3, the skirts on both sides of peak 3 e,
When the tangent line connecting f is Hesler's ef, the intensity of peak 3 from the baseline ef is 3.

e, as shown in Figure 3, the skirts g on both sides of peak 4,
When the tangent line connecting h is defined as the baseline gh, the intensity of peak 4 from the baseline gh is assumed to be 14.

Note the following points regarding each peak. Special Public Service 1986
-104818 Publication When the crystal structure described in Figure 2 (a) is slightly included, diffraction peaks from the crystal structure different from the present invention occur, so the following trends are observed in each peak. It will be done. Peak 1 is the hem of the high angle, peak 2 is the hem of the low angle side is the shoulder, or the corresponding peak 1 is the hem of the low angle side.
．． It may have a peak smaller than 2. The way to take the baseline at this time is to select peaks that are smaller than the shoulder or the corresponding peaks 1 and 2, and
In this case, the next adjacent valley that was crossed on the high angle side is taken as b, and the next next valley that was crossed on the low angle side for peak 2 is taken as C, and the baseline is taken.

As the amount of the structure of the present invention increases, the intensity of peak 3 decreases, making it difficult to obtain the baseline. When a peak cannot be distinguished from noise and a baseline cannot be obtained, each peak intensity is considered to be 0. Also, at that time, point e is used as point f of the baseline fi.

■ Diffraction intensity calculation According to the method for determining each peak intensity in ■, peak 11 peak 2
, Relative intensity of peak 3, peak 4 R,, R2, R3, R
4 is obtained from the following equation.

R+ =1+ /IoxlOO(%)・・・・・・
... (1) R2 = [2/ Io X100 (%) ...
・・・・・・・・・(2) R3=I3/I o X1
00(%)・・・・・・・・・(3)R4=14/r
o X100 (%) (4) [Example] Hereinafter, specific examples of the syndiotactic polystyrene structure of the present invention will be described with reference to Examples.

(Preparation of raw material syndiotactic polystyrene) 600 ml of toluene and 120 mmol of methylaluminoxane (manufactured by Toyo Stufer) in a container purged with inert gas.
and added 0.6 mmol of tetraethoxytitanium,
Next is styrene 600mj! was added and a polymerization reaction was carried out at 50'C for 2 hours. After the reaction was completed, the reaction was stopped with hydrochloric acid/methanol, and the resulting polymer was filtered off and dried.

The resulting polystyrene (hereinafter referred to as syndiotactic polystyrene A) weighed 92 g. The content of methyl ethyl ketone insoluble part in this polystyrene is 96
%, and the stereoregularity of this insoluble part was 99% or more syndiotactic structure as a result of C-NMR spectrum analysis. °C
The number average molecular weight Mn determined from 2.47 x
It was 10'. The X-ray diffraction pattern of the syndiotactic polystyrene A obtained here is shown in FIG.

Example 1 5 mg of syndiotactic polystyrene A thus obtained was melted at 290°C under a nitrogen atmosphere, and then heated at 200°C at a cooling rate of 0.31°C/min under the same atmosphere.
The target structure was obtained by cooling to C.

The X-ray diffraction pattern of this structure is shown in FIG.

Peak 1, Peak 2, Peak 3, Peak 4, Peak O,
The scattering angle 2θ of peak 5 is also 6.1 degrees and 12.3 degrees, respectively.
It appeared at 15.7 degrees, 18.5 degrees, 20.3 degrees, and 35.0 degrees, and the relative intensity of each peak had the following values. This shows that this structure is specified by the present invention. The melting point of this structure is 263.3°C, and gel permeation chromatography (1
, 2,4-) measured at 130° C. in dichlorobenzene), the number average molecular weight Mn was not substantially different from that of syndiotactic polystyrene A.

R, = 14%, R2 = 35%, R3 = 1.4%, R4 = 11% Comparative Example 1 Syndiotactic polystyrene A5■ was melted at 290°C under a nitrogen atmosphere, and then the cooling rate was adjusted under the same atmosphere. A structure B was obtained by cooling to 200°C at a rate of 80°C/min. The X-ray diffraction pattern of this structure is shown in FIG. The scattering angle 2θ of peak 1, peak 2, peak 3, peak 4, peak 0, and peak 5 is 6.7 degrees and 11.7 degrees, respectively (there is also a peak at 12.2 degrees as a shoulder. Calculation of relative intensity In this case, we used 11.6 degrees.), 15.5 degrees, 1
It appeared at 7.9 degrees, 20.3 degrees, and 35.3 degrees, and the relative intensity of each peak had the following values. The melting point of this structure is 263.8°C, and gel permeation chromatography (1,2° in 4-trichlorhenzene,
The number average molecular weight Mn (measured at 130°C) was substantially the same as that of syndiotactic polystyrene A.

R+ = 30%, R2 = 18%, R3 = 7.1%, Ra = 3.2% The characteristics of the X49 diffraction pattern of the structure of the present invention with respect to structure B include the following points.

■ The scattering angle of peak 1 is relative to the scattering angle of structure B,
The structure of the present invention has a diffraction peak on the low angle side. In Example 1, the scattering angle of peak 1 was 6.2 degrees, whereas in Comparative Example 1, the scattering angle of peak 1 of structure B was 6.7 degrees.
It was degree.

■ The scattering angle of peak 2 is relative to the scattering angle of structure B,
The structure of the present invention has a diffraction peak on the high angle side. In Example 1, the scattering angle of peak 2 was 12.3 degrees, whereas in Comparative Example 1, the scattering angle of peak 2 was 11 degrees.
．． It was 6 degrees.

■ The scattering angle of peak 4 is relative to the scattering angle of structure B,
The structure of the present invention has a diffraction peak on the high angle side. In Example 1, the scattering angle of peak 4 was 18.5 degrees, whereas the scattering angle of peak 2 of structure B in comparative example 1 was 17 degrees.
．． It was 9 degrees.

■ The scattering intensity of peak 3 with respect to the baseline ef is
Compared to the scattering intensity of structure B, the structure of the present invention has a scattering intensity of almost 0.
(R3=less than 5%). In Example 1, R of peak 3
3 was 1.4%, whereas R3 of Structure B of Comparative Example 1 was 7.1%.

■ The scattering intensity of peak 4 with respect to the baseline gh is
Compared to the scattering intensity of Structure B, the structure of the present invention has a large value (Ra-5% or more).

In Example 1, R4 of peak 3 was 11%, whereas R4 of Structure B of Comparative Example 1 was 3.2%.

Comparative Example 2 The X-ray diffraction pattern of the syndiotactic polystyrene polymer shown in FIG. 2(a) of Japanese Patent Publication No. 62-104818 is shown in FIG. The relative intensity of each peak had the following values. peak 1, peak 2, peak 3
, peak 4, and peak O have scattering angles 2θ of 6.9 degrees, respectively.
It appeared at 11.9 degrees, 15.6 degrees, 18.0 degrees, and 20.5 degrees. In addition, the syndiotactic polystyrene polymer of Example 1 of Japanese Patent Publication No. 62-104818 has a molecular weight of 260 to 27
It is described as having a melting point of 0°C.

R1-27%, Rz=30% R3=16%, R4=11% Comparing these values and the X-ray diffraction pattern with the relative intensity and XWA diffraction pattern listed in Example 1, Comparative Example 1 shows that
The structure of the present invention is significantly different from Example 1 in the points listed in (1) to (4). Therefore, it can be seen that the two have clearly different crystal structures.

Example 2 Syndiotactic polystyrene A5■ was melted at 290°C under a nitrogen atmosphere, and then the cooling rate was 320°C.
The mixture was cooled to 262° C./min and kept at that temperature for 80 hours for crystallization to obtain the desired structure. X of this structure
The vA diffraction pattern is shown in FIG. Peak 3 is hardly observed, peak 1, peak 2, peak 4, peak 0
, peak 5 appeared at scattering angles 2θ of 6.2 degrees, 12.4 degrees, 18.6 degrees, 20.4 degrees, and 35.1 degrees, respectively, and the relative intensity of each peak had the following values. The melting point of this structure is 273.2°C, and the number average molecular weight Mn determined by gel permeation chromatography (measured at 130°C in 1,2,4-trichlorhenzene) is syndiotactic. It was not substantially different from polystyrene A.

R1-15%, Rz=32% R3-0%, Ra=11% Example 3 In the same manner as in Example 2, 5 mg of syndiotactic polystyrene A was melted at 290°C under a nitrogen atmosphere, and then cooled. It was cooled to 240°C at a rate of 320°C/min and kept at that temperature for 5 hours for crystallization to obtain the desired structure. The X-ray diffraction pattern of this structure is shown in FIG. The scattering angles 2θ of peak 1, peak 2, peak 3, peak 4, peak 0, and peak 5 are 6.3 degrees, 12.5 degrees, 15.7 degrees, 18.7 degrees, 20.5 degrees, respectively.
It appeared at 35.3 degrees, and the relative intensity of each peak had the following values. Furthermore, the melting point of this structure is 259.0°C, and gel permeation chromatography (L2,4
-) The number average molecular weight Mn determined from (measured at 130° C. in lychlorhenzene) was not substantially different from that of syndiotactic polystyrene A.

R1=14%, R2=36% R3=1.4%
, R4=11%

[Brief explanation of the drawing]

Figure 1 is from the drawing in Japanese Patent Publication No. 62-104818 (Figure 2).
This is a transcription of the xvA diffraction pattern of syndiotactic polystyrene in a). FIG. 2 is an X-ray diffraction pattern of syndiotactic polystyrene A synthesized according to the method for preparing raw material syndiotactic polystyrene. FIG. 3 shows the Xv of the structure obtained according to Example 1.
It is an X-ray diffraction pattern of structure A. FIG. 4 is an X-ray diffraction pattern of the structure obtained according to Comparative Example 1. FIG. 5 is an X-ray diffraction pattern of the structure obtained according to Example 2. FIG. 6 is an X-ray diffraction pattern of the structure obtained according to Example 3. Note that FIGS. 2 to 6 show X-ray diffraction patterns of a non-oriented syndiotactic polystyrene structure when CuKα rays (wavelength 0.15418 nm) are used as incident X-rays. Further, the numbers in the figure represent the diffraction peaks of the corresponding numbers, and the broken line shows how to take the baseline. The horizontal axis is the scattering angle (θ is the Bragg angle [°], and the vertical axis is the scattering intensity. Patent applicant Asahi Kasei Corporation = 17-1 Figure 3 Figure 2 in? 2θ deg in? 2θ deg 4th Figure 1n↑ 2θ deg

Claims (1)

[Claims] As incident X-rays, CuKα rays (wavelength 0.15418 nm
), scattering angle 2θ = 11.8 to 13.0 degrees,
2θ=18.1 to 19.3 degrees, 2θ=19.6 to 21
．． The relative intensity for the diffraction peaks appearing twice is 2
Has a diffraction peak of 0%, 5% or more, and 2θ = 5.5
~6.6 degrees, 2θ=15.0 to 16.2 degrees, 2θ=1
Syndiotactic polystyrene having a diffraction peak whose relative intensity to the diffraction peak appearing at 9.6 to 21.2 degrees is less than 20% and 5%, respectively.