JPH0614017B2 - Method and apparatus for measuring softening point distribution of thermosoftening substance - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for measuring a softening point distribution of a thermosoftening substance.

Prior Art and its Problems One of the physical property values of a material that softens due to heat is the softening point, which is defined as the temperature at which the material softens. As a method of measuring the softening point, generally, a method of raising the temperature of a substance under a constant load and measuring the temperature when the substance becomes soft is used. More specifically, due to the difference in the "softening" detection method, (a) a method of measuring the temperature at which the tensile elastic modulus drops sharply, (b) a constant flow of a substance from a capillary under a constant load (discharge) ) A method of measuring the starting temperature, (c) a method of measuring the temperature at which a substance starts to deform under a constant load, and the like are used. As a matter of course, due to the difference in the "softening" detection method, the softening point values of the same substance are measured slightly differently.

Furthermore, in general, most of the substances that are softened by heat are rarely uniform in the molecular structure, composition and / or molecular weight of their constituent molecules, and are mostly composed of a multi-component heterogeneous phase. Since the above-mentioned softening point measuring method measures one softening point for one substance, the multicomponent substance only shows the softening point as an average value. If the multi-component substance is homogeneously mixed on the molecular order, the softening point of the substance is represented by one point. However, it is rare that each component is homogenized on a molecular order in a multi-component substance, and as described above, inhomogeneity is often present to some extent. Such inhomogeneity may be due to mere density fluctuations in the state of molecular aggregation, different aggregation forms of crystalline and amorphous, or inhomogeneity due to sample preparation such as the surface and the inside of the sample. In some cases. In addition, phase separation may occur due to the difference in molecular weight of each component or the difference in molecular structure. Furthermore, not only a multi-component system basically composed of components having a similar structure, but also a mixed system composed of two or more partially or completely incompatible components can be regarded as a multi-component system. Even in these cases, there are obviously various inhomogeneities within the substance.

However, according to the known softening point measuring method, the softening point of a multi-component substance having inhomogeneity inside the substance as described above is also shown as one softening point, and the qualitative and quantity of the inhomogeneity It was not possible to obtain a softening point indication including a physical evaluation. Also, when only a part of the components in the sample softens,
It was impossible to measure the temperature or quantitatively evaluate the softening component amount.

Means for Solving Problems The present inventor has conducted various studies in view of the current state of the art as described above, and as a result, a thermosoftening substance prepared to have a specific particle size and a specific particle size and a substance which is not softened by heat When a sample of a homogeneous mixture with a constant volume ratio is heated under constant pressure to accurately measure the volume change of the sample when the thermosoftening substance softens, and when performing differential treatment, etc., the softening point of the thermosoftening substance It has been found that the distribution can be measured, and that the amount of each component can be quantitatively evaluated for a mixture having different softening point components.

That is, the present invention provides the following method and apparatus for measuring the softening point distribution of a thermosoftening substance.

A / B <1 by volume ratio of thermosoftening substance (A) prepared to have a particle size of 40 mesh or less and within a certain range and substance (B) which is not softened by heat prepared to the same particle size. Uniformly mixed, the volume change of the sample is measured in a temperature range in which the thermosoftening substance is softened by heating at a constant heating rate under a constant pressure in a container whose volume change due to heat is small, and the measured value A method for measuring a softening point distribution of a thermosoftening substance, characterized by performing a differential operation after correcting the temperature.

A container with a small volume change due to heat for accommodating a sample consisting of a thermosoftening substance and a substance not softened by heat, a mechanism for applying a constant pressure to the sample in the container, a sample in the container at a constant temperature rising rate A mechanism for heating, a mechanism for measuring the volume change of the sample in the softening temperature region of the sample, and a data processing mechanism for creating and analyzing a softening point distribution curve of the thermosoftening substance according to the volume change of the sample were provided. An apparatus for measuring a softening point distribution of a thermosoftening substance, which is characterized in that:

In the present specification, the term "thermosoftening substance" means a substance at least a part of which is softened by heat, and includes organic substances, inorganic substances, and mixtures of both. or,
"Material that does not soften by heat" or "heat stable material"
Means a substance that does not soften under pressure conditions within a temperature range in which the thermosoftening substance to be measured softens (for example, high-purity alumina, ceramics such as silicon carbide, metals such as iron and titanium) . As the heat-stable substance, it is desirable that the change in strength, volume, etc. due to heat is small within the temperature range.

When measuring the softening point distribution according to the present invention, both the heat-softening substance and the heat-stable substance are pulverized or granulated in advance to a particle size of a certain particle size or less and a certain range, and a sample in which both are uniformly mixed is used. Prepare. In order to measure the softening point distribution more accurately, it is generally preferable that the particle size of both substances is as small as possible and the particle size distribution is as narrow as possible.
Practically, the powder may be prepared so that the particle size is 40 mesh or less and the particle size distribution is as narrow as possible. The powder may be prepared by any method such as crushing, granulating, sieving, or a combination thereof, but an operation that affects thermal softening (for example, long-time heating at a softening temperature or higher or reaction It is necessary to avoid the contact with the active gas) as much as possible and to make the heat softening substance and the heat stable substance have the same average particle size and particle size distribution.

It is essential that the mixing ratio of the heat softening substance (A) and the heat stable substance (B) is A / B <1 in terms of volume ratio. However, as the amount ratio of the thermosoftening substance becomes smaller, the measurement accuracy of the volume change of the sample at the time of heating decreases, and when the amount ratio of the thermosoftening substance is below a certain value or above, the softening point distribution obtained is clear. Since it disappears, A / B is preferably about 0.1 to 0.4, although it depends on the average particle size of the sample.

A sample consisting of a homogeneous mixture of a heat-softening substance and a heat-stable substance should be placed in a container in which the volume change due to heat is small or the volume change due to heat has been accurately measured beforehand, and under a constant pressure and at a constant temperature rising rate. Then, the volume change of the sample due to the softening of the thermosoftening substance is accurately measured. The material of the container is not particularly limited, but metal, ceramic, or the like, which is less likely to change in volume by heat, is preferable. As the shape of the container,
A tubular shape or a thin tubular shape, which has a small volume change due to heat and is sensitive to the volume change of the sample, is also preferable. The pressure during heating and the heating rate are not particularly limited, but the normal pressure is 0.5.
It is selected from the range of about 30 kg / cm ² · G and the rate of temperature rise of about 0.5 to 20 ° C./min. However, when the pressure and / or the heating rate is different, the shape of the obtained softening point distribution curve is also different. Therefore, when comparing different samples, it is necessary to adopt the same pressure and heating rate conditions. is there.

The method for measuring the volume change of the sample in the container may be any method, but as an example of an easy and accurate method of operation, the sample is put in a tubular or thin tubular container with little volume change, For example, there is a method of measuring the position variation and the temperature change of the upper surface of the sample while applying a constant load from the upper part using, for example, a differential transformer and a temperature sensor.

Here, the measurement principle of the softening point distribution of the heat-softening substance in the present invention will be briefly described. When the fine powder of the heat-softening substance and the fine powder of the heat-stable substance having the same particle size are uniformly mixed, , As shown in FIG. 1 (a) (however, the heat softening substance / heat stable substance = 0.3 (volume ratio), and the hatched one is the heat softening substance). Here, as an occupied volume of each particle of the thermosoftening substance, a volume of the particle itself and voids existing around the particle are considered together. When the temperature is raised while applying a constant pressure to this sample in the container, the volume occupied in the container does not change until the softening component in the thermosoftening substance softens. When the temperature reaches a temperature at which a part of the sample softens, the occupied volume gradually decreases. It is now considered that the particles of the softening component in the thermosoftening substance are sufficiently small, and each particle has its own softening temperature ▲ T ⁱ _s ▼ (i = 1, 2, 3, ..., N). And the particle i is softened at a temperature of ▲ T ⁱ _s ▼, and the space between the particles of the heat-stable material is filled.
It decreases by Δυ _i at the temperature of T ⁱ _s ▼. Here, the volume reduction amount (Δυ _i ) when the softening component particles (i) in one thermosoftening substance softens is strictly different among the individual particles, but the size of the particles should be as small as possible. By making the sample uniform, mixing the entire sample uniformly, and increasing the number of particles (N), it is possible to treat all particles on average as the same value (Δυ). When all the softening component particles (i = N) in the thermosoftening substance have softened, the occupied volume in the container does not change again (see FIG. 1 (b)). Thus, a temperature-dependent occupied volume change (decrease) curve as shown in FIG. 2 is obtained. Moreover, the number of particles (N) of the softening component in the thermosoftening substance is sufficiently large, and in reality, the individual particles are not T _i. Considering the beginning and end of softening at
The curve is smooth as shown by (I) in FIG. Then, by differentiating this curve (I), the softening point distribution curve (II) of the thermosoftening substance is obtained. Here, ΔT is a temperature range when each particle is softened, and since it differs depending on the particle size, constituent molecules, molecular aggregation state, temperature rising rate, pressure, etc., strictly speaking, it differs for each particle, but the softening point In the calculation of the distribution curve, it is considered that ΔT is sufficiently small and the softening point of each particle (i) can be represented by one point of Ti. Prior to the differentiation process, if necessary, a more accurate softening point distribution curve is obtained by correcting the temperature change curve (I) of the occupied volume by the thermal expansion of the heat stable substance, the thermal expansion of the container, etc. You can also In the present invention based on such a principle, the particle size of the heat-softening substance and the heat-stable substance should be as small as possible and the same particle size, and it is important for accurate measurement to increase the number of particles. It will be clear that there is.

FIG. 4 is a block diagram showing the outline of an example of the softening point distribution measuring device of the present invention. The sample (1) is contained in a container (2) equipped with multi-divided temperature sensors (3) and (3). The container (2) is installed in a heat retaining section (5) equipped with a heating section (4). Temperature control unit under pressure by pressure application unit (6)
The change in the occupied volume of the sample (1) which is heated while being controlled by (8) is detected by the displacement measuring unit (7), and the data processing unit
After being treated by (9), a change curve of the sample occupied volume and a softening point distribution curve of the heat softening substance as shown by curves (I) and (II) in FIG. 3 are obtained.

Effects of the Invention According to the present invention, the following remarkable effects are achieved.

(i) A softening point distribution curve of a substance, at least a part of which is softened by heat, can be obtained with good reproducibility in a wide temperature range from low temperature to high temperature.

(ii) It is possible to evaluate the content of a component that is softened by heat and the degree of spread of the softening point.

(iii) It is possible to quantitatively evaluate the molecular aggregation state and the phase separation behavior in the multi-component system and the mixed system substance from the viewpoint of the softening point distribution.

(iv) The softening point distribution can be measured and analyzed for substances and components that are softened by heat even if they are completely insoluble in a solvent.

(v) Since rapid and accurate measurement and analysis are possible, it can be used to track the transition of various reactions.

Example 1 A heat-softenable aromatic oligomer having an average softening point of 230 ° C. (using a softening point measuring device manufactured by Mettler, Switzerland) was pulverized and prepared at room temperature to a particle size of 250 to 280 mesh. On the other hand, high-purity alumina which is not softened by heat even at 350 ° C. was pulverized to a particle size of 250 to 280 mesh. Next, these powders were mixed at a ratio of 3 parts by volume of oligomer and 10 parts by volume of high-purity alumina to obtain a uniform mixture. After placing 10 g (about 3 cm ₂ ) of the obtained mixture sample in a hard chromium-plated steel cylindrical container having a cross-sectional area of 1 cm ₂ equipped with a pressure applying device, the oligomer may react with oxygen in the atmosphere of the container. The atmosphere in the container was replaced with nitrogen gas so as not to exist. Then, 10kg / cm ²
While the pressure of G was applied, the entire container was uniformly heated at a temperature rising rate of 3 ° C./min, and the change in the occupied volume of the sample within the temperature range of 100 to 310 ° C. was measured. The change in the occupied volume of the sample was measured by converting the height variation of the position measuring disk placed on the upper surface of the sample into an alternating electrical signal by a differential transformer and detecting it. The data signal from the temperature sensor and the differential transformer goes through a linearizer, an amplifier, and an AD converter (12 bits) to a computer (PC).
-9801, manufactured by NEC Corporation), and after performing data correction and various noise processing, differential processing is performed and X
-It was output as a softening point distribution curve on a Y plotter. The result is shown by the solid line in FIG.

From the results shown in FIG. 5, the softening point distribution in the sample was clarified, which was not known from the conventional softening point measurement showing only the overall average value. That is, the aromatic oligomer used in this example is a mixed system of the softening point components having the maximum values at 150 ° C. and 230 ° C., and the distribution curve is 2
From the area ratio obtained by separating into two mountains, the component ratio is 3:
It turned out to be 7.

Example 2 Using the same aromatic oligomer as in Example 1 and high-purity alumina, the softening point distribution was measured under the same conditions as in Example 1, and the reproducibility of the measurement results was examined.

As a result, as shown by the broken line in FIG. 5, a softening point distribution curve similar to that of Example 1 was obtained, demonstrating that the method of the present invention has excellent measurement reproducibility.

Example 3 An aromatic oligomer similar to that used in Example 1 was melted at 350 ° C., stirred at a high speed, blown from a nozzle having a diameter of 1 mm at a speed of 50 m / min, and rapidly cooled to −50 ° C. A softening point distribution curve was measured in the same manner as in Example 1 except that this material was used as a heat softening material.
The result is as shown in FIG. 6, and a single-peak softening point distribution curve having a maximum point at 205 ° C. was obtained.

It was clarified by the measurement based on the present invention that the state of molecular aggregation was significantly different due to the difference in the pretreatment even with the same thermosoftening substance.

Example 4 The same aromatic oligomer as that used in Example 1 was held in an oxygen atmosphere at 420 ° C. for 30 minutes to make it a substance infusible to heat. 3 parts by volume of this heat-infusible substance and 7 parts by volume of the above aromatic oligomer were heated to 380 ° C. to perform apparent mixing. The softening point distribution was measured in the same manner as in Example 1 except that the obtained mixture was used instead of the aromatic oligomer.

In this case, the reduction ratio of the occupied volume of the sample in the measurement temperature range of 90 to 310 ° C. is 30 as compared with the case of Example 1.
%, And the mixing ratio of the thermally infusible substance in this example was obtained by measuring the occupied volume change of the sample.

Comparative Example 1 A softening point distribution curve was obtained in the same manner as in Example 1 except that high-purity alumina was not used in Example 1.
The results are shown in Fig. 7.

As can be seen from the results of FIG. 7, when the measurement was performed without using high-purity alumina, it was not possible to obtain a distribution curve that accurately represents the entire softening point distribution of the heat-softening substance.

[Brief description of drawings]

1 (a) is a schematic diagram showing a mixed state of a sample for measuring softening point distribution before heat softening, and FIG. 1 (b) is a schematic diagram showing a mixed state of the same sample after heat softening, 2nd FIG. 4 is a graph for explaining changes in the occupied volume of the sample due to thermal softening, FIG. 3 is a graph showing the change in the actually occupied volume of the sample, and FIG. 4 is a softening point distribution measurement of the present invention. Drawing which shows one example of an apparatus, 5th
FIG. 6 and FIG. 6 are graphs showing the softening point distribution curves obtained in the examples of the present application. FIG. 7 is a graph showing a softening point distribution curve obtained in Comparative Example 1 of the present application. FIG. 4 is a block diagram showing the outline of an example of the softening point distribution measuring device of the present invention. (1) …… Sample, (2) …… Container, (3) …… Multi-divided temperature sensor, (4) …… Heating part, (5) …… Insulating part, (6) …… Pressure applying part, ( 7) …… Displacement measuring section, (8) …… Temperature control section, (9) ……
Data processing unit.

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Claims (2)

[Claims] 1. A heat-softening substance (A) prepared so as to have a particle size of 40 mesh or less and within a certain range, and a substance (B) which is not softened by heat and is prepared to have a similar particle size in a volume ratio of A / B. <1
To uniformly mix, to measure the volume change of the sample in the temperature range in which the thermosoftening substance is softened by heating at a constant heating rate under a constant pressure in a container with a small volume change due to heat,
A method for measuring a softening point distribution of a thermosoftening substance, characterized by performing a differential operation after correcting the measured value. 2. A container having a small volume change due to heat for containing a sample composed of a thermosoftening substance and a substance not softened by heat, a mechanism for applying a constant pressure to the sample in the container, and a sample in the container. Mechanism for heating at a constant heating rate, mechanism for measuring the volume change of the sample in the softening temperature range of the sample, and data for creating and analyzing the softening point distribution curve of the thermosoftening substance according to the volume change of the sample An apparatus for measuring a softening point distribution of a thermosoftening substance, characterized by comprising a processing mechanism.