JP2770554B2 - Analyzer for molecular weight distribution of polymer materials and additives - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a technique for analyzing the average molecular weight of a polymer material itself or a product produced from the polymer material, and an additive contained therein. About.

(Prior art) To control the quality of polymer materials themselves and the products made from them, know the average molecular weight of the molecules that compose them and the concentration of additives added to them. Is a very important factor. The average molecular weight and molecular weight distribution are measured by the gel permeation method, and the additives are once extracted with a solvent, and then analyzed by other analytical equipment such as high-performance liquid chromatography, gas chromatography, infrared analyzer, mass spectrometer, etc. Was performed in combination.

Therefore, the analysis of the molecular weight relationship for one sample,
The analysis of the additives must be performed as a separate analysis task,
There was a problem that it took time.

(Problems to be Solved by the Invention) The present invention has been made in view of such a problem, and an object thereof is to reduce the average molecular weight, the molecular weight distribution, and the concentration of the additive by one sample injection. It is an object of the present invention to provide a novel analyzer that can detect the light.

(Means for Solving the Problems) In order to solve such a problem, in the present invention,
A sample injection port at one end, a gel permeation analysis column for measuring the molecular weight distribution of a polymer having a first detector connected to the other end, and a flow path switching means at an outlet of the first detector. A trap coil connected to the first detector, a first resistance tube whose one end connected to the discharge port side of the first detector and branched to the trap coil is open to the atmosphere, A second resistance tube provided on the discharge port side of the trap coil;
One end is connected to the trap coil via the flow path switching means, and the other end is provided with an additive measurement analysis column having a second detector connected thereto, using an output signal of the first detector. In addition to measuring the molecular weight distribution of the polymer, qualitative or quantitative analysis of the additive is performed using the output signal of the second detector.

(Action) The sample is separated by a gel permeation analysis column in order of molecular weight, and the molecular weight is analyzed. Then, the components in the low molecular weight region are analyzed by the second analysis means, and the sample is injected once. Gives data on average molecular weight, molecular weight distribution, and additives.

(Embodiment) Therefore, the details of the present invention will be described below based on an illustrated embodiment.

FIG. 1 shows an embodiment of the present invention, wherein reference numeral 1 denotes a gel permeation analysis column for separating samples in order of molecular weight, and a sample inlet 2 at an inflow end.
And a differential refractometer 4 at the outflow end. The discharge end of the differential refractometer 4 is connected via a branch pipe 5 to a resistance pipe 6 whose one end is open to the atmosphere, and a switching valve 7. The switching valve 7 is configured to be able to switch between the first and second flow paths. The first flow path includes a trap coil 8 communicating with the atmosphere via a resistance tube 6, and an analysis column 10 via a mixing device 9. An analysis flow path connected to the ultraviolet light detector 11 is configured.

The second flow path is connected from the mixing device 9 to the trap coil 8 once, and the other end of the trap coil 8 is connected to the analysis column.
In the mixing device 9 in which a flow path connected to 70 is configured,
Mobile phases are supplied from pumps 14 and 15 communicating with tanks 12 and 13 containing different mobile phases, respectively, so as to prepare mobile phases of components suitable for analysis of additives.

Reference numeral 16 denotes a control device comprising a microcomputer, which determines the distribution of the molecular weight of the sample and the components of additives based on signals from the differential refractometer 4 and the ultraviolet light detector 11. Operating the switching valve 7 based on the first
It is programmed to switch from the first flow path to the second flow path.

Reference numeral 17 in the figure denotes a tank containing a mobile phase suitable for gel permeation analysis, and reference numeral 18 denotes a resistance tube for regulating the amount flowing into the trap coil 8.

In this embodiment, with the switching valve 7 set to the first flow path (the flow path indicated by the solid line in the figure), diethyl phthalate (DEP), dibutyl phthalate (DBP), and When a solution prepared by dissolving a beer chloride sheet to which tricresyl phosphate (TCP) is added in a solvent is injected as a sample, the sample is transferred to a mobile phase tank,
7 flows into the gel permeation analysis column 1 together with the mobile phase supplied therefrom, and is separated on the basis of the molecular weight. The polymer component (FIG. 2 II) and the low molecular component, that is, the additive ( 2) and flows into the differential refractometer 4 in two groups.

The controller 6 determines a signal (FIG. 3 II) from the differential refractometer 4 based on a calibration curve obtained by previously examining the relationship between the elution time and the molecular weight, and determines the molecular weight and the molecular weight at each time point. The average molecular weight is determined, and the ratio between the differential molecular weight (FIG. 4I) and the integrated molecular weight (FIG. 4II) is calculated based on the average molecular weight.

In this way, the component discharged from the gel permeation analysis column 1 depends on the flow path resistance of the resistance tube 6 and the resistance tube.
The fluid flows into the trap coil 8 at a ratio determined by the flow path resistance of 18, and the remainder is discharged out of the system via the resistance tube 6.

When the component based on the polymer passes through the differential refractometer 4 and the component of the low molecular additive (FIG. 2I) flows into the differential refractometer 4, a predetermined time from this point, that is, the low molecular component After a lapse of time until the gas flows into the trap coil 8, the switching valve 7 is switched to the second flow path (the flow path indicated by a dotted line in the figure).
Switch to

Thus, the low molecular weight component flowing into the trap coil 8 is discharged from the trap coil 8 by the mobile phase from the mixing device 9 and flows into the analysis column 10. At this point, a mobile phase suitable for analyzing the additive, in this example a varying mixture of methanol and water, is provided. As a result, diethyl phthalate (DEP), dibutyl phthalate (DBP), and tricresyl phosphate (TCP) constituting the additives are separated for each component. The components discharged from the analytical column 10 flow into the ultraviolet light detector 11, and the identification and concentration of the components are determined by the control device 16 (FIG. 5).

In this embodiment, a branch pipe is provided between the differential refractometer 4 and the trap coil 8, and a resistance pipe 18 is connected to an outlet of the trap coil 8 to control the amount of additive flowing into the trap coil 8. To adjust. Further, as shown in FIG. 6, a three-way valve provided with a resistance tube 21 and a black plug 24 via a branch pipe 20 on the inflow side of the analytical column 10.
23 is connected, and when the additive initially contained in the trap coil 8 is split according to the ratio of the resistance tubes 22 and 21 or the resistance tube 21 ', the amount flowing into the analytical column 10 can be adjusted. Next, the three-way valve 23 may be switched to the black plug 24 to stop the split operation. In addition, three-way valve
The switching operation of 23 can be performed by the control device 16 at an appropriate timing.

In this example, the components from the gel permeation analysis column were detected by a differential refractometer, and the components from the analysis column were detected by an ultraviolet light detector. Depending on the object, other detectors,
It goes without saying that the mobile phase is selected.

(Effects of the Invention) As described above, in the present invention, a gel permeation analysis column in which a sample injection port is connected to one end and a detection means is connected to the other end, and a gel permeation analysis column. Since a trap coil connected to the outlet through the flow path switching means and a low-molecular analysis means connected to the trap coil through the flow path switching means are provided, a polymer material can be formed by a single sample injection. It is possible to measure the molecular weight and the distribution of the molecular weight of the components used, and the components of the additives, thereby simplifying the measurement operation.

[Brief description of the drawings]

FIG. 1 is a block diagram of an apparatus showing one embodiment of the present invention, FIG. 2 is a view showing a chromatogram by a differential refractometer in the apparatus, and FIG. 3 is a weighing showing the relationship between molecular weight and elution time. FIG. 4 shows a chromatogram of a line and a polymer component, and FIG.
The figure is a diagram showing the relationship between the differential molecular weight and the integrated molecular weight, FIG. 5 is a diagram showing a chromatogram of an additive component by an ultraviolet light detector, and FIG. 6 is a configuration diagram showing another embodiment of the present invention. is there. 1 ... Gel permeation analysis column 2 ... Sample inlet 4 ... Differential refractometer 7 ... Flow path switching valve 8 ... Trap coil 9 ... Mixing device 10 ... Analysis column 11 ... Ultraviolet Photo detector

Claims (1)

(57) [Claims] 1. A gel permeation analysis column for measuring a molecular weight distribution of a polymer having a sample inlet at one end and a first detector connected to the other end, and a flow port at an outlet of the first detector. A first end of the trap coil connected via the path switching means and one end of which is connected to the discharge port side of the first detector and which is connected to the flow path to the trap coil is open to the atmosphere. A resistance tube and a second port provided on the discharge port side of the trap coil.
One end of the resistance tube, the one end is connected to the trap coil via the flow path switching means, the other end is provided with an additive measurement analysis column connected to the second detector, the first detector of the In addition to measuring the molecular weight distribution of the polymer using the output signal, qualitative or quantitative analysis of the additive is performed using the output signal of the second detector, and the molecular weight distribution of the polymer material is characterized in that , And additive analyzer.