JP5156279B2 - Polyolefin crystallinity distribution analyzer and method - Google Patents

Description

  The present invention relates to a crystallinity distribution analyzer for crystalline polyolefin and a method for analyzing the crystallinity distribution of crystalline polyolefin using the same. More specifically, the crystalline polyolefin sample solution is passed through a temperature-controlled filter, the precipitated components are separated, and the change in the concentration of the passing solution is detected. The present invention relates to an analysis apparatus and a method for analyzing the crystallinity distribution of a crystalline polyolefin using the apparatus.

  In general, polyolefin is a heterogeneous mixture with respect to any or all of molecular structures such as molecular weight, chemical composition, stereoregularity, etc., and has a broad crystallinity distribution as a reflection thereof. And the quality of polyolefin is greatly influenced by crystallinity distribution. Therefore, obtaining the correct information regarding the crystallinity distribution is essential for quality improvement studies of polyolefins.

Conventionally, temperature rising elution fractionation (TREF) has been widely used as a means for analyzing the crystallinity distribution of polyolefin (for example, see Non-Patent Document 1). However, this method has the following drawbacks. That is, for example, it consists of two steps: a crystallization process by cooling and an elution process by raising the temperature, so that the time required for analysis becomes longer and the temperature of a column that is large enough to hold a sample is controlled. For this reason, the apparatus becomes large-scale, and therefore, temperature control in each process cannot be performed quickly. In addition, in order to compensate for the drawbacks of these TREFs, a method for quickly controlling the column temperature by directly controlling the temperature of the solvent used for elution has been proposed (see, for example, Patent Document 1). However, this method has drawbacks such as requiring excessive trial and error in determining analysis conditions and requiring a complicated apparatus. On the other hand, a method of analyzing the crystallinity distribution by measuring the concentration of the remaining solution in the crystallization process by cooling has been proposed (see, for example, Patent Document 2). However, although this method can simplify the process, it is necessary to increase the size of the container in order to obtain a sufficient amount of the remaining solution, and has a drawback that it is difficult to speed up the temperature control.
US Published Patent No. 2006-54543 JP-T 6-511316 Polymer Preprint, Am. Chem. Soc. , Polym. Chem. Div. , 18, 182 (1977)

  In view of the present situation, the problem to be solved by the present invention is to solve the problems of the prior art, and to analyze the crystallinity distribution of polyolefin extremely efficiently and simply, and polyolefin using the same An object of the present invention is to provide a method for analyzing the crystallinity distribution.

  As a result of intensive studies to solve the above-mentioned problems, the inventors have passed the crystalline polyolefin sample solution through a temperature-controlled filter to separate the precipitated components, and by detecting the concentration change of the passing solution, We found that the crystallinity distribution of the sample can be analyzed very efficiently and simply, and developed an apparatus for analyzing the crystallinity distribution. Using the above-mentioned apparatus, the sample solution of crystalline polyolefin was heated from high temperature to low temperature. It has reached the method of analyzing the crystallinity distribution characterized by obtaining the crystallization curve by separating the precipitated components by passing through a controlled filter and continuously detecting the change in concentration of the passing solution. .

That is, according to the first invention of the present invention, an apparatus for analyzing the crystallinity distribution of a crystalline polyolefin, a filter for collecting precipitated components, and for continuously feeding a solvent into the filter Means for injecting the sample solution into the filter, means for continuously detecting the concentration change of the solution that has passed through the filter, and changing the temperature of the filter at a rate of 10 ° C. or more per minute. it has a constant temperature bath which may,該恒Yutakaso is crystalline distribution analysis apparatus characterized by comprising means for temperature control only the filter is provided.

  According to a second aspect of the present invention, there is provided an analyzer characterized in that, in the first aspect, the volume of the thermostatic bath is 100 cubic centimeters or less.

According to a third aspect of the present invention, there is provided the analyzer according to the first or second aspect , wherein the thermostatic chamber is made of an aluminum block.

According to a fourth aspect of the present invention, there is provided the analyzer according to any one of the first to third aspects, wherein a Peltier element is used as a cooling means for the thermostatic bath.

According to a fifth aspect of the present invention, there is provided the analyzer according to the fourth aspect , comprising means for cooling the heat radiation side of the Peltier element with a cooling medium.

According to a sixth aspect of the present invention, there is provided a method for analyzing the crystalline distribution of crystalline polyolefin using the crystalline distribution analyzer according to the first aspect, wherein the temperature of the sample solution is increased from high temperature to low temperature. Crystallization by passing through a controlled filter, changing the temperature of the filter when passing through it at a rate of 10 ° C / min or more, separating the precipitated components, and continuously detecting changes in the concentration of the passing solution A method for analyzing the crystallinity distribution of a crystalline polyolefin characterized by obtaining a curve is provided.

According to the seventh invention of the present invention, in the sixth invention, the temperature of the filter is cooled from 80 ° C. or more to 40 ° C. or less until a fixed volume of the solution has passed through the filter. An analysis method is provided.

According to the eighth aspect of the present invention, there is provided the analysis method according to the seventh aspect , wherein the time required for cooling is 15 minutes or less.

  The crystallinity distribution analyzer of the crystalline polyolefin of the present invention significantly reduces the temperature chamber by taking a novel method of controlling the temperature of only the filter, and as a result, has a very high control efficiency of a rate of 10 ° C. or more per minute. In order to measure the crystallinity distribution of crystalline polyolefin, a method for analyzing the crystallinity distribution very efficiently and simply was provided, and the analysis time could be dramatically shortened.

  The crystalline polyolefin crystallinity distribution analyzer of the present invention includes at least a filter for collecting precipitated components, means for continuously feeding a solvent into the filter, and injecting a sample solution into the filter. , Means for continuously detecting a change in the concentration of the solution that has passed through the filter, and a thermostatic chamber capable of changing the temperature of the filter at a rate of 10 ° C. or more per minute.

  FIG. 1 shows a conceptual diagram of an analyzer according to a preferred embodiment of the crystalline polyolefin crystallinity distribution analyzer of the present invention. In FIG. 1, a crystallinity distribution analyzer according to the present invention includes a solvent tank 1, means 2 for continuously feeding a solvent into a filter for collecting deposited components, and a method for injecting a sample solution into the filter. Means 3, filter 4 for collecting precipitated components, constant temperature bath 5 that can change the temperature of the filter at a rate of 10 ° C./min or more, temperature control device 6, concentration change of the solution that has passed through the filter It consists of the means 7 for detecting automatically, and devices and facilities other than these may be attached. In addition, it is usually necessary to separately provide equipment for using the sample as a solution. Each component will be described below.

(1) The solvent tank 1 is not limited in shape and size, but is made of a material that is not corroded by the solvent used. For example, glass or stainless steel is preferable.

(2) As the means 2 for continuously feeding the solvent into the filter, a normal pump is used. There is no particular limitation on the shape of the pump, and a rotary pump, a reciprocating pump, etc., a centrifugal pump, a centrifugal pump, an axial flow pump, a mixed pump, etc. can be used. A graphic pump or the like is preferably used.

(3) The means 3 for injecting the sample solution into the filter is an injector. As the injector, a heat-resistant four-way valve, a six-way valve, etc. are preferable, and the sample loop is 1 ml or more. Those having a capacity are preferred. A combination of auto samplers may also be used.

(4) The filter 4 for collecting the precipitated components is not particularly limited in shape and size as long as there is no problem with heat resistance. Absent. A small column packed with a carrier such as glass beads or chromosolve (diatomaceous earth) so that the effective volume is 0.01 ml to 1 ml is preferable. In order to increase the transfer of heat from the thermostat, it is better to increase the surface area of the column, and it is preferable that the column surface area is 3 to 50 square centimeters per cubic centimeter of the column. A spiral shape is preferred.
The precipitated components collected on the filter are removed from the filter by a method such as increasing the temperature of the solvent after dissolution is completed.

(5) There is no limitation on the shape and size of the thermostatic chamber 5 that can change the temperature of the filter at a rate of 10 ° C. or more per minute, but in order to shorten the time required for analysis, Cooling is necessary and it is preferable to make it as small as possible. Although it can be used as an air thermostat of a gas chromatography apparatus, it is not very practical because it is inferior to rapid cooling and control accuracy. As the thermostatic chamber, preferably, an aluminum block serving as a main body is provided with a heater as a heating means and a Peltier cooling element as a cooling means. Also, a refrigerant such as liquid nitrogen can be used as the cooling means.
Further, for the purpose of increasing the cooling efficiency of the constant temperature bath, it is preferable to add a cooling means to the cooling means attached to the constant temperature bath. For example, when a Peltier element is used as the cooling means for the thermostatic bath, a means for cooling with a cooling medium can be provided on the heat radiation side in order to cool the Peltier element. As the cooling medium used for the cooling means, water, salt water, alcohols and mixtures thereof are preferable. Preferably, a mixture of ethylene glycol and water is used. Further, there is a method of cooling the heat dissipation side of the Peltier element with another Peltier element, and a multilayer structure in combination with a cooling medium may be used.
One of the features of the present invention is that only the temperature of the filter portion of the analyzer is changed, and the temperature changing portion is smaller than that of the conventional device, so that temperature control is easy.

(6) As the temperature control device 6, for example, a program temperature controller or the like is used.

(7) The means 7 for continuously detecting the change in the concentration of the solution that has passed through the filter is appropriately selected depending on the polymer to be analyzed. For example, an infrared spectrophotometer or a Raman spectrophotometer A differential refractometer, a differential pressure viscometer, a light scattering detector, an evaporative light scattering detector, or the like is used. A plurality of detectors can be used in combination.

  With the analyzer of the present invention, it is possible to quickly measure the crystallinity distribution of polyolefin without degrading accuracy.

  Next, the principle of analysis will be described below with reference to FIG. 1 which is a preferred embodiment. In FIG. 1, 1 is a solvent tank, 2 is a pump, 3 is an injector, 4 is a filter, 5 is a thermostatic bath, 6 is a temperature control device, and 7 is a detector.

(A) A crystalline polyolefin sample is mixed with a solvent and heated to obtain a uniform sample solution. If the solution concentration is too low, the measurement accuracy is lowered. If the solution concentration is too high, the viscosity of the solution increases and causes clogging. Therefore, 0.1 mg / ml to 10 mg / ml is preferable. The heating temperature is appropriately selected and determined depending on the polymer to be analyzed. For example, in the case of polypropylene, about 140 ° C. is preferable. Specific examples of the solvent that can be used include aromatic hydrocarbons that may be halogen-substituted, such as orthodichlorobenzene, trichlorobenzene, toluene, xylene, etc .; aliphatic linear or branched hydrocarbons such as n-octane, n-decane etc. can be mentioned, and any one or a mixture of these may be used, and alcohols may be included. Preferably, it is selected from orthodichlorobenzene and trichlorobenzene. Antioxidants such as BHT (di-t-butyl-p-cresol), Irganox 1010 (tetrakis- [methylene- (3,5-di-tert-butyl-4-hydroxy-hydrocinnamate) butane]) Etc. can also be added to a solvent.

(B) A predetermined amount of the prepared sample solution is held in the apparatus system by the injector 3. The temperature of the injector needs to be kept high enough not to precipitate the polymer. For example, in the case of polypropylene, about 140 ° C. is preferable. The injection amount needs to be sufficient to continue to pass through the filter until the temperature of the filter has dropped to a predetermined temperature, and is determined by the relationship between the cooling time of the filter and the flow rate. For example, when the cooling time of the filter is 10 minutes and the flow rate is 0.5 ml / min, 5 ml or more is necessary.

(C) On the other hand, the solvent is stored in the solvent tank 1. The solvent used may be the same as that used for preparing the solution, or may be different. Preferably, it is selected from orthodichlorobenzene and trichlorobenzene.

(D) The sample solution held in the apparatus system passes through the filter 4 by sending the solvent by the pump 2.

(E) While the sample solution passes through the filter 4, as shown in FIG. 2, the temperature of the filter 4 is cooled by a constant temperature bath 5 at a constant rate. The degree of cooling is controlled by the temperature control device 6. The time required for cooling needs to be within the time required for the sample solution having a constant volume to pass through the filter 4.
While the sample solution passes through the filter, the temperature of the filter is controlled. The degree of cooling does not necessarily have to be constant with respect to time, and may be stepped, for example, but it is preferable to use a constant cooling rate for data processing because it is easy to handle. The temperature range is appropriately selected and determined depending on the polymer to be analyzed, but it is preferable that the crystalline polyolefin as a whole is cooled from a high temperature of 80 ° C. or higher to a low temperature of 40 ° C. or lower. For example, in the case of block polypropylene which is a mixture of polypropylene and an ethylene-propylene copolymer, it is preferable to cool from 140 ° C to -15 ° C. Therefore, the time required for cooling is preferably 15 minutes or less.

(F) FIG. 3 shows a change in the state of the solution when passing through the filters in A, B, and C shown in FIG. In state A, the temperature of the filter is sufficiently high and no precipitation due to crystallization occurs. Therefore, the solution that has passed through the filter has the same concentration as the solution before passing. In state B, precipitation due to crystallization occurs due to a decrease in filter temperature. Since the deposited components are collected by the filter, the solution that has passed through has a lower concentration than the solution before the passage. Furthermore, in the low temperature state C, since the component having lower crystallinity is precipitated, the concentration becomes lower.

(G) Therefore, the time change of the concentration obtained by the detector 7 is as shown in FIG.

(H) The change over time of the concentration is plotted against the filter temperature corresponding to each time, and normalized by the initial concentration, the cumulative crystallization curve of FIG. 5 can be obtained.

(I) Furthermore, by differentiating this cumulative crystallization curve with respect to temperature, the differential crystallization curve of FIG. 6, that is, the crystallinity distribution can be obtained.

  Examples of the crystalline polyolefin to which the crystallinity distribution analysis method of the present invention can be applied include polyolefin homopolymers, copolymers of olefins, copolymers of olefins and dienes, and the like. Examples of the polyolefin homopolymer include polyethylene, polypropylene, polybutene, and poly-4-methyl-pentene-1. Examples of the olefin copolymers include copolymers of propylene and α-olefin (including random copolymers and block copolymers), copolymers of ethylene and butene-1. Although the present invention is an analytical method for crystalline polyolefin, it can also be applied to crystalline polymers other than crystalline polyolefin.

  The following examples further illustrate the invention, but the invention is not limited thereto.

Example 1
(1) Analyzer Solvent tank: DURAN glass bottle 2L
Pump: SSC-3461 manufactured by Senshu Science
Injector: Barco 6 port (sample loop: 2 ml)
Filter: Inner diameter 2mmφ, Length 40mm Stainless steel pipe (U-shaped), Chromosolv P (60/80 mesh) filling Constant temperature bath: 35mm x 35mm x 7mm aluminum block, surface heater and Peltier element (water cooling) stacked on top and bottom temperature control Equipment: Kino 1000 manufactured by Chino
Detector: MIRAN1A manufactured by FOXBORO
(2) Analysis conditions Solution concentration: 1 mg / ml
Solvent: Orthodichlorobenzene (BHT 0.25 mg / ml added)
Injection volume: 2ml
Flow rate: 0.4 ml / min Filter temperature range: 135 ° C to -15 ° C
Cooling rate: 30 ° C./min Cooling time: 5 minutes Analysis time: 5.5 minutes (3) Sample Linear low density polyethylene (UF240 manufactured by Nippon Polyethylene Co., Ltd.)
(4) Analysis Results The obtained crystallization curve is shown in FIG.

(Comparative Example 1)
Analysis by conventional TREF was performed.
(1) Analyzer Solvent tank: DURAN glass bottle 2L
Pump: SSC-3461 manufactured by Senshu Science
Injector: Barco 6 port (sample loop: 0.1 ml)
Filter: Inner diameter 4.3 mmφ, length 150 mm Stainless steel column, inert glass beads (80/100 mesh) packed Constant temperature bath: 230 mm x 100 mm x 35 mm aluminum block, Laminating surface heater and Peltier cooling element (air cooling) on the bottom Control device: Chino KP1000
Detector: MIRAN1A manufactured by FOXBORO
(2) Analysis conditions Solution concentration: 5 mg / ml
Solvent: Orthodichlorobenzene (BHT 0.25 mg / ml added)
Injection volume: 0.1ml
Flow rate: 1 ml / min Temperature range: 140 ° C to 40 ° C
Cooling rate: 2 ° C / min Cooling time: 50 minutes Holding time: 5 minutes Heating rate: 2 ° C / min Temperature rising time: 50 minutes Total analysis time: 105 minutes (3) Sample Linear low density polyethylene (Nippon Polyethylene Co., Ltd.) UF240 made by company)
(4) Analysis result The obtained crystallization curve is shown in FIG.

  As is clear from Example 1 and Comparative Example 1, in measuring the crystallinity distribution of linear low-density polyethylene, the measurement time is extremely short (Example 1: 5.5 minutes) compared with conventional TREF (see Comparative Example 1). Comparative Example 1: 105 minutes), the same result was obtained, and the usefulness of this analysis method could be confirmed.

(Example 2)
(1) Analytical apparatus Same as Example 1 (2) Analytical conditions Same as Example 1 (3) Sample Homopolypropylene (MA3UD manufactured by Nippon Polypropylene Co., Ltd.)
(4) Analysis result The obtained crystallization curve is shown in FIG.

(Example 3)
(1) Analytical apparatus Same as Example 1 (2) Analytical conditions Same as Example 1 (3) Sample Random polypropylene (F203T manufactured by Nippon Polypropylene Co., Ltd.)
(4) Analysis result The obtained crystallization curve is shown in FIG.

(Comparative Example 2)
Analysis by conventional TREF was performed.
(1) Analytical apparatus The same as Comparative Example 1 (2) Analytical conditions The same as Comparative Example 1 (3) Sample Homopolypropylene (MA3UD manufactured by Nippon Polypropylene Co., Ltd.)
(4) Analysis result The dissolution curve obtained by TREF is shown in FIG.

(Comparative Example 3)
Analysis by conventional TREF was performed.
(1) Analytical apparatus Same as Comparative Example 1 (2) Analytical conditions Same as Comparative Example 1 (3) Sample Random polypropylene (F203T, manufactured by Nippon Polypropylene Co., Ltd.)
(4) Analysis result The obtained crystallization curve is shown in FIG.

  As is clear from Examples 2-3 and Comparative Examples 2-3, homopolypropylene and random polypropylene also have an extremely short time (Examples 2 and 3: 5) compared to conventional TREF (see Comparative Examples 2 and 3). 5 minutes, Comparative Examples 2 and 3: 105 minutes), the same results were obtained, and the usefulness of this analysis method could be confirmed.

  The crystallographic distribution analyzer of the crystalline polyolefin of the present invention can remarkably reduce the temperature chamber, and as a result, achieves extremely high control efficiency, can be analyzed very efficiently and simply, and has a dramatic analysis time. Can be shortened, which is very useful in industry.

It is a conceptual diagram of the analyzer used for this invention. It is a conceptual diagram which cools the temperature of a filter with a thermostat. It is a conceptual diagram which shows the state change of the solution at the time of passing a filter. It is a graph showing the time change of the density | concentration obtained by a detector. It is a graph of the accumulation crystallization curve obtained by plotting the time change of a density | concentration with respect to the filter temperature corresponding to each time. It is a graph obtained by differentiating the cumulative crystallization curve. 2 is a crystallization curve obtained in Example 1. 2 is a crystallization curve obtained in Examples 2 and 3. FIG. 2 is a dissolution curve obtained in Comparative Example 1. 3 is a dissolution curve obtained in Comparative Examples 2 and 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solvent tank 2 Pump 3 Injector 4 Filter 5 Thermostatic bath 6 Temperature control apparatus 7 Detector

Claims (8)

  An apparatus for analyzing the crystalline distribution of crystalline polyolefin, a filter for collecting precipitated components, means for continuously feeding a solvent into the filter, and for injecting a sample solution into the filter Means, a means for continuously detecting the concentration change of the solution that has passed through the filter, and a thermostatic chamber capable of changing the temperature of the filter at a rate of 10 ° C. or more per minute, And a crystallinity distribution analyzer having means for controlling the temperature of only the filter.   2. The analyzer according to claim 1, wherein the temperature chamber has a volume of 100 cubic centimeters or less. 3. The analyzer according to claim 1, wherein the thermostatic chamber is made of an aluminum block. The analyzer according to any one of claims 1 to 3 , wherein a Peltier element is used as a cooling means for the thermostatic chamber. 5. The analyzer according to claim 4, further comprising means for cooling the heat radiation side of the Peltier element with a cooling medium.   A method for analyzing the crystallinity distribution of a crystalline polyolefin using the crystallinity distribution analyzer according to claim 1, wherein the sample solution is passed through a filter whose temperature is controlled from a high temperature to a low temperature. Crystallinity distribution analysis characterized by obtaining a crystallization curve by changing the temperature of the filter at a rate of 10 ° C or more per minute, separating the precipitated components, and continuously detecting the concentration change of the passing solution. Method. The analysis method according to claim 6 , wherein the temperature of the filter is cooled to 80 ° C. or more and 40 ° C. or less until a fixed volume of the solution has passed through the filter. The analysis method according to claim 7 , wherein the time required for cooling is 15 minutes or less.

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