JP2571254B2 - Syndiotactic polystyrene - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a novel syndiotactic polystyrene.

[Conventional technology]

The 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 the polymerization of styrene (Japanese Patent Application Laid-Open No. Sho 62-104818). Gazette,
FIG. 1 shows an X-ray diffraction chart of the syndiotactic polystyrene exemplified in FIG. 2 (a) of JP-A-62-187708. According to the X-ray chart, it is understood that the known syndiotactic polystyrene has a crystal structure. Syndiotactic polystyrene with similar crystal structure
1986, 19, 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 JP-A-62-187708. From this,
The structure obtained according to Japanese Patent Application Laid-Open No. 62-187708 is syndiotactic polystyrene because of its stereoregularity, but it can be seen that its crystal structure contains many amorphous regions.

A syndiotactic polystyrene structure containing many amorphous regions in this way, when recrystallized under a molding process involving thermal changes such as melting (melting) and cooling, a heterogeneous structure in which multiple crystal structures are mixed Since a body is formed, a molded body having poor mechanical properties is obtained.

The present invention provides a syndiotactic polystyrene having a uniform crystal structure different from known syndiotactic polystyrene and capable of obtaining a molded article having excellent mechanical properties.

[Means for solving the problem]

In the present invention, CuKα rays (wavelength 0.15418 n
m), scattering angle 2θ = 11.8 to 13.0 degrees, 2θ = 1
At 8.1 to 19.3 degrees, relative intensities to diffraction peaks appearing at 2θ = 19.6 to 21.2 degrees have diffraction peaks of 20% and 5% or more, respectively, and 2θ = 5.5 to 6.6 degrees and 2θ = 15.0 to 16.2 degrees, It is a syndiotactic polystyrene having a relative intensity with respect to a diffraction peak appearing at 2θ = 19.6 to 21.2 degrees of less than 20% and 5%, respectively. The syndiotactic polystyrene of the present invention can be used as a molded resin material or a resin molded product.

The structure of the syndiotactic polystyrene of the present invention can be produced by the following method using the syndiotactic polystyrene prepared by a known polymerization method described in JP-A-62-187708 as a raw material. Can be. The polymer used as a raw material has a syndiotacticity and a number average molecular weight of 99% or more and 1.0 × 10 ⁴ or more, respectively, and those exhibiting at least useful mechanical properties even in a molded product are selected. The syndiotacticity and the number average molecular weight do not substantially change under the following production method.

(1) The raw material polymer is melted (melted) at 240 ° C. to 270 ° C. in the presence of an atmosphere of an inert gas such as 1 atm, nitrogen or argon.
A method of isothermal crystallization in a temperature range of 5 ° C. for 5 to 3000 hours.

Hereinafter, unless otherwise specified, the values are shown for structures obtained at 1 atm under a nitrogen atmosphere.

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

In the above method, a crystal nucleus such as an inorganic substance is put in a melt state and crystallized, thereby increasing or decreasing the crystallization speed, shifting the crystallization temperature region, or expanding or narrowing. It is possible.

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

1) Stereoregularity and number average molecular weight measurement The stereoregularity was determined from the C1 carbon spectrum of the benzene ring in a ¹³ C-NMR spectrum (nuclear magnetic resonance spectrum by isotope carbon) according to Makromol. Chem., 176.3051 (1975). Number average molecular weight is determined by gel permeation chromatography (measured in 1,2,4-trichlorobenzene at 130 ° C.)
I asked more.

2) Measurement of melting point of crystal structure The melting point of the crystal structure was determined from the peak of a chart obtained when a 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 TSC-2C Measurement atmosphere: Nitrogen atmosphere (at a flow rate of 20 cc / min) Temperature rise rate during melting chart measurement: 10 ° C / min Refrigerant of the apparatus: ice water 3) Identification method of crystal structure Identification of crystal structure The X-ray diffraction method commonly used for crystal structure analysis is used.

FIG. 3 is a representative 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, 11.8 to 1
Diffraction peak 1, peak 2, peak 4, peak 0, and peak 5 are remarkably observed at 3.0 degrees, 18.1 to 19.3 degrees, 19.6 to 21.2 degrees, and 34.0 to 36.0 degrees, but diffraction at a scattering angle 2θ of 15.0 to 16.2 degrees. The diffraction intensity of peak 3 is extremely small. The syndiotactic polystyrene structure of the present invention has a scattering angle of 15.0 to 1
A diffraction peak is hardly recognized at 6.2 °, or the diffraction intensity is extremely small even if there is a diffraction peak.

Reading of Diffraction Intensity a. As shown in FIG. 3, when a tangent connecting a valley f formed by peaks 0 and 3 and a valley i formed by peaks 0 and 5 is defined as a baseline fi, a scattering angle 2θ = 19.5 ~ 21.3
Let the intensity of the diffraction peak 0 from the baseline fi be I ₀ .

b. Connect Figure 3, when both sides of the foot a peak 1, the tangent line connecting the b is the baseline ab, peak 1, the intensity from baseline ab and I _1.

c. As shown in FIG. 3, when a tangent connecting the tails c and d on both sides of the peak 2 is defined as a baseline cd, the intensity of the peak 2 from the baseline cd is defined as I ₂ .

d. As shown in FIG. 3, when both sides of the skirt e peaks 3, a tangential connecting f and baseline ef, peak 3, the intensity from baseline ef and I _3.

e. If you shown in FIG. 3, both sides of the foot g peak 4, when the tangent line connecting the h a baseline gh, peak 4, the intensity from baseline gh and I _4.

Note the following points for each peak. JP 62
In the case where the crystal structure described in FIG. 2 (a) of JP-A-087708 is slightly contained, diffraction peaks from a crystal structure different from that of the present invention are generated, and the following tendency is observed in each peak. The peak 1 may have a high-angle tail, and the peak 2 may have a shoulder at the low-angle side or a peak smaller than the corresponding peaks 1 and 2, respectively. At this time, the baseline is set as follows: the shoulder or a peak smaller than the corresponding peaks 1 and 2;
Then, the base line is set with c as the valley immediately adjacent to the lower angle side.

As the amount of the structure of the present invention increases, the intensity of peak 3 decreases, and it becomes difficult to obtain a baseline. If a peak cannot be distinguished from noise and a baseline cannot be obtained, the intensity of each peak is regarded as 0. At this time, the point e is used as the point f of the baseline fi.

The relative intensities R ₁ , R ₂ , R ₃ , and R ₄ of the peak 1, peak 2, peak 3, and peak 4 can be obtained from the following formulas in accordance with the method of calculating each peak intensity in the calculation of diffraction intensity.

R ₁ = I ₁ / I ₀ × 100 (%) …… (1) R ₂ = I ₂ / I ₀ × 100 (%) ……… (2) R ₃ = I ₃ / I ₀ × 100 (%) (3) R ₄ = I ₄ / I ₀ × 100 (%) (4) Examples 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) In a container purged with an inert gas, 600 ml of toluene and 120 mmol of methylaluminoxane (manufactured by Toyo Stouffer) were added.
And 0.6 mmol of tetroethoxytitanium, and then 600 ml of styrene, and a polymerization reaction was performed at 50 ° C. for 2 hours.
After completion of the reaction, the reaction was stopped with hydrochloric acid / methanol, and the produced polymer was separated by filtration and dried. The resulting polystyrene (hereinafter referred to as syndiotactic polystyrene A) weighed 92 g. The content of the methyl ethyl ketone insoluble portion of this polystyrene was 96%, and the stereoregularity of the insoluble portion was 99% or more in syndiotactic structure as a result of ¹³ C-NMR spectrum analysis. The number average molecular weight Mn determined by gel permeation chromatography (measured in 1,2,4-trichlorobenzene at 130 ° C.) is 2.4.
7 × 10 ⁴ The X-ray diffraction pattern of the obtained syndiotactic polystyrene A is shown in FIG.

Example 1 5 mg of the syndiotactic polystyrene A thus obtained was melted at 290 ° C. under a nitrogen atmosphere.
Under the same atmosphere, cool to 200 ° C at a cooling rate of 0.31 ° C / min.
The desired structure was obtained. The X-ray diffraction pattern of this structure is shown in FIG. Peak 1, peak 2, peak 3, peak 4, peak 0, and peak 5 each have a scattering angle 2θ of 6.1.
Degrees, 12.3 degrees, 15.7 degrees, 18.5 degrees, 20.3 degrees, 35.0 degrees,
The relative intensity of each peak had the following values. This allows
It can be seen that this structure is what the invention specifies. The melting point of this structure was 263.3 ° C., and the number average molecular weight M determined by gel permeation chromatography (measured in 1,2,4-trichlorobenzene at 130 ° C.)
n was not substantially different from syndiotactic polystyrene A.

R ₁ = 14%, R ₂ = 35% R ₃ = 1.4%, R ₄ = 11% Comparative Example 1 5 mg of syndiotactic polystyrene A was melted at 290 ° C. in a nitrogen atmosphere, and then the cooling rate was 8 in the same atmosphere.
The structure was cooled to 200 ° C. at 0 ° C./min to obtain B. The X-ray diffraction pattern of this structure is shown in FIG. The peak 1, peak 2, peak 3, peak 4, peak 0, and peak 5 have a scattering angle 2θ of 6.7 degrees and 11.7 degrees (12.
There is a peak twice. In calculating the relative intensity, 11.6 degrees was used. ), 15.5 degrees, 17.9 degrees, 20.3 degrees, 35.3 degrees,
The relative intensity of each peak had the following values. The melting point of this structure was 263.8 ° C., and gel permeation chromatography (1,2,4-trichlorobenzene contained 1
(Measured at 30 ° C.) and the number average molecular weight Mn was not substantially different from that of syndiotactic polystyrene A.

R ₁ = 30%, R ₂ = 18% R ₃ = 7.1%, R ₄ = 3.2% The features of the structure of the present invention with respect to the structure B on the X-ray diffraction pattern are as follows. .

The scattering angle of the peak 1 is relative to the scattering angle of the 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 the scattering angle of peak 1 of structure B of comparative example 1 was 6.7 degrees.

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 the scattering angle of peak 2 of structure B of comparative example 1 was 11.6 degrees.

The scattering angle of the peak 4 is relative to the scattering angle of the 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 of comparative example 1 was 17.9 degrees.

The scattering intensity of the peak 3 with respect to the baseline ef is almost 0 in the structure of the present invention with respect to the scattering intensity of the structure B (R ₃ = less than 5%). In Example 1, R ₃ of peak ₃ is 1.
Whereas been made in 4%, R ₃ of structure B of Comparative Example 1 is 7.1%
It was.

The scattering intensity of the peak 4 relative to the baseline gh has a larger value in the structure of the present invention than the scattering intensity of the structure B (R ₄ = 5% or more). In Example 1, R ₄ of peak 3 is
Compared to 11%, R ₄ of Structure B of Comparative Example 1 was 3.2%.
%.

Comparative Example 2 FIG. 1 shows an X-ray diffraction pattern of a syndiotactic polystyrene polymer given in FIG. 2 (a) of JP-A-62-187708. The relative intensity of each peak had the following values. Peak 1, peak 2, peak 3, peak 4, and peak 0 have scattering angles 2θ of 6.9, 11.9, and 1 respectively.
Appeared at 5.6, 18.0, and 20.5 degrees. Incidentally, JP-A-62-187
The syndiotactic polystyrene polymer of Example 1 of 708 is described as having a melting point of 270 ° C.

R ₁ = 27%, R ₂ = 30% R ₃ = 16%, R ₄ = 11% When these values are compared with the X-ray diffraction pattern and the relative intensity and X-ray diffraction pattern given in Example 1, a comparative example is obtained. 1,
The features of the structure of the present invention are significantly different from those of the first embodiment in the points described above. Thus, it can be seen that both have distinct crystal structures.

Example 2 5 mg of syndiotactic polystyrene A was melted at 290 ° C under a nitrogen atmosphere, and then cooled at a cooling rate of 320 ° C / min.
Cool to 2 ° C, keep at that temperature for 80 hours to crystallize,
The desired structure was obtained. The X-ray diffraction pattern of this structure is shown in FIG. The peak 3 is hardly observed, and the peak 1, peak 2, peak 4, peak 0, and peak 5 show scattering angles 2θ at 6.2 degrees, 12.4 degrees, 18.6 degrees, 20.4 degrees, and 35.1 degrees, respectively. The relative intensity has the following values: The melting point of this structure was 273.2 ° C., and the number average molecular weight Mn determined by gel permeation chromatography (measured in 1,2,4-tricklebenzene at 130 ° C.) was equal to that of syndiotactic polystyrene A. Substantially unchanged.

R ₁ = 15%, R ₂ = 32% R ₃ = 0%, R ₄ = 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. Then, it was cooled to 240 ° C. at a cooling rate of 320 ° C./min, and was crystallized at that temperature for 5 hours to obtain a target structure. The X-ray diffraction pattern of this structure is shown in FIG. Peak 1,
Peak 2, peak 3, peak 4, peak 0, and peak 5 have scattering angles 2θ of 6.3 degrees, 12.5 degrees, 15.7 degrees, and 18.
Appearing at 7 degrees, 20.5 degrees, and 35.3 degrees, the relative intensity of each peak had the following values. The melting point of this structure was 259.0 ° C., and gel permeation chromatography (1,2,
The number average molecular weight Mn determined from 4-trichlorobenzene at 130 ° C.) was not substantially different from that of syndiotactic polystyrene A.

R ₁ = 14%, R ₂ = 36% R ₃ = 1.4%, R ₃ = 11%

[Brief description of the drawings]

FIG. 1 is a transcript of the X-ray diffraction pattern of syndiotactic polystyrene shown in FIG. 2 (a) of Japanese Patent Publication No. Sho 62-104818. FIG. 2 is an X-ray diffraction pattern of syndiotactic polystyrene A synthesized according to a method for preparing a raw material syndiotactic polystyrene. FIG. 3 is an X-ray diffraction pattern of an X-ray structure of the structure obtained according to Example 1. FIG. 4 is an X-ray diffraction pattern of the structure obtained according to Comparative Example 1. FIG.
6 is an X-ray diffraction pattern of a structure obtained according to Example 2. FIG. 6 shows the X of the structure obtained according to Example 3.
It is a line diffraction pattern. 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. The numbers in the figure represent the diffraction peaks of the corresponding numbers, and the broken lines indicate how to set the baseline. The horizontal axis represents the scattering angle (θ is the Bragg angle [゜], and the vertical axis represents the scattering intensity.

Claims (1)

(57) [Claims] (1) As an incident X-ray, CuKα ray (wavelength: 0.15418 n
m), scattering angle 2θ = 11.8 to 13.0 degrees, 2θ = 1
At 8.1 to 19.3 degrees, relative intensities to diffraction peaks appearing at 2θ = 19.6 to 21.2 degrees have diffraction peaks of 20% and 5% or more, respectively, and 2θ = 5.5 to 6.6 degrees and 2θ = 15.0 to 16.2 degrees, Syndiotactic polystyrene having 20% and less than 5% diffraction peaks relative to the diffraction peaks appearing at 2θ = 19.6-21.2 degrees, respectively.