JPS604420B2 - Photochemical reaction heat measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photochemical reaction heat device for measuring reaction heat during a photochemical reaction of a photosensitive material.

When high-energy radiation such as light is projected onto a photosensitive material such as a photosensitive resin, a photochemical reaction such as photopolymerization occurs, and at that time, heat generation or endotherm is observed.

It is important to measure the reaction heat due to this photochemical reaction and to determine the reaction rate from the calorimetric measurement in order to investigate the optimal conditions for the reaction. Traditionally, there have been calorimeters that measure changes such as melting, transition, and decomposition that occur when a temperature rise is applied to a certain substance, or thermal changes such as heat generation and endotherm that occur when different types of substances are mixed. However, there was no device that could measure the amount of heat generated or absorbed in the photochemical reaction at a constant temperature as described above.

The present invention provides an apparatus for measuring the amount of heat generated or absorbed by decomposition, polymerization, etc. when a photosensitive material is stimulated by light.

By the way, the reaction rate in a photoreaction differs depending on the temperature of the sample itself, so when measuring the amount of heat, it is necessary to keep the temperature of the sample constant by keeping the external temperature atmosphere constant. However, even if the external temperature is held constant at this time, the temperature of the sample itself changes due to its own reaction heat, making it difficult to perform highly accurate measurements. Furthermore, even when attempting to maintain the external surface of the sample constant, thermal noise appears, which adversely affects measurement accuracy. Therefore, this invention prevents large temperature changes in the sample by installing the sample dish in the overflow tank via a heat leak type temperature detector such as a thermo module, and quickly leaking the reaction heat to the constant temperature tank. In addition, two sample plates are placed at thermally equivalent positions in the temperature chamber, and radiation is projected while the sample is placed on only one sample plate, and the calorific value is calculated based on the temperature difference between the two. Another object of the present invention is to provide a photochemical reaction heat measurement device that can accurately measure reaction heat without being affected by thermal noise by measuring the amount of heat absorbed. Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 1 denotes a constant temperature chamber of a calorimeter, 2 a constant temperature chamber provided in the center of this constant temperature chamber 1, and the upper part of this constant temperature chamber 2 being closed by a glass plate 3. 4 is the constant temperature room 2 above.
An atmosphere controller adjusts the atmosphere during photochemical reactions by creating a vacuum inside the chamber or filling it with a gas such as N2 gas that does not react with the sample; 5 is a temperature controller for maintaining the entire Jojo constant temperature chamber 1 at a predetermined temperature; For example, by running a circulation pipe (not shown) inside the wall of the thermostatic chamber 1,
By circulating a temperature-controlled fluid within this circulation pipe, the temperature of the wall heating tank 7 is kept constant.

Reference numeral 6 denotes a holder for a sample plate placed in the thermostatic chamber 2, and this holder 6 is a heat leak type holder with relatively good thermal conductivity and a large cross-sectional area, which is placed on the heat reservoir part la of the constant salt chamber 1. Thermoelectric element (e.g. semiconductor temperature sensor such as thermo module) 7
The thermoelectric element 7 is installed in close thermal contact with the lower surface of the holder 6 and the upper surface of the heat reservoir section la due to the minute temperature difference between the thermoelectric element 7 and the lower surface of the holder 6. The amount of heat per unit time leaking through the element 7 by conduction is detected, and an output voltage corresponding to this is generated.

8 is a differential amplifier that appropriately amplifies the potential difference V, V2 across the thermoelectric element 7, and 9 is a recording device that records the output from the differential amplifier 8.

Then, the temperature controller 5 is activated to
After placing a sample plate containing a sample on the holder 6 while maintaining the sample at a predetermined temperature, when radiation such as light is irradiated from above the glass plate 3, the sample undergoes a photochemical reaction and generates heat. , absorbs heat, a temperature difference (approximately 0.01K) is generated between the holder and the heat reservoir la, and the amount of heat is transferred via the thermoelectric element 7.

This heat transfer then generates a corresponding potential difference across the thermoelectric element 7, which is appropriately amplified by the differential amplifier 8 and recorded in the recording device 9 as a function of time. In this way, the progress of the photochemical reaction can be read from the record of the recording device 9, and the integral value of this recorded value corresponds to the total calorific value of the sample during the photochemical reaction. Therefore, according to this device, the heat generated in the sample is always conducted to the heat reservoir la through the thermoelectric element 7, and since the heat reservoir la has a sufficiently large heat capacity, the temperature hardly changes. First, because the thermoelectric element 7 has good thermal conductivity, the temperature of the sample itself does not change much, and the reaction can proceed in an atmosphere at a temperature close to a predetermined isothermal state.

At this time, instead of the sample, place a substance that has the same heat capacity as the sample and does not react photochemically in the sample dish, and (
Alternatively, if you irradiate radiation (directly onto the sample plate without placing anything on it), check in advance the thermal change in the holder at that time, and correct the actual measured amount, the amount of heat of the radiation absorbed by the holder and sample plate It is possible to measure the true heat of reaction excluding the

Figure 2 shows a twin-type calorimeter that simultaneously corrects the influence of thermal changes due to radiation when measuring reaction heat.
6b are arranged via thermoelectric elements 7a and 7b, one holder 6a holds a sample plate containing a sample, and the other sample plate 6M holds a comparison substance that has the same heat capacity as the sample and does not react with light. The applied blood sample is tested at Atsushi.

And each holder 6 of the thermoelectric elements 7a and 7b
Potential difference Va-V between the parts in close contact with the lower surfaces of a and 6b
b is suitably amplified by a differential amplifier 8, and the temperature difference between the holder 6a on the sample side and the holder 6b on the reference side is recorded in the recording device 9. Here, 1 is a light source for generating radiation (selected as appropriate depending on the substance to be reacted, such as a xenon lamp, an ultra-high pressure mercury lamp, a metal halide lamp, or a laser); A lens system 12 is a filter that passes a ray of a desired wavelength from among the parallel rays, and the light source 10
, a lens system 11, and a filter 12 constitute a light source system. Reference numeral 13 denotes a reflector for reflecting the parallel light rays from the light source system downward; 14 denotes a mirror for controlling the projection time of the reflected light; 15a and 15b are arranged in parallel below the mirror 14; , the holders 6a and 6b are set in advance to adjust the amount of the reflected light beam.
Thermoelectric elements 7a and 7b measure the temperature of the sample plate by placing a sample plate on which no sample is applied and projecting the light beam from the light source system onto the sample plate.
By adjusting the variable valves 14a and 14b so that the temperature difference between the two sample blood becomes zero, the temperature rise of the sample blood due to radiation is made to be the same for the left and right sample blood.

In this way, we made the calorimeter a twin-type calorimeter and measured the sample side in comparison with the reference side, which does not have a sample layered, so even if there is thermal noise in the temperature of the fence temperature tank, this is completely ignored. The amount of heat generated is unaffected, and the amount of heat absorbed can be measured with high precision.

In addition, in the above example, a holder for placing the sample is used with the power generation element in close contact with the bottom surface of the holder, but in order to improve heat conduction between the holder and the thermoelectric element, the bottom of the holder is made of the thermoelectric element itself. You can make it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory diagram of a photochemical reaction heat measuring device according to the present invention, and FIG. 2 is a schematic explanatory diagram showing an example of its embodiment. 1... Wall heating tank, 6, 6a, 6b... Holder,
7, 7a, 7b...Thermoelectric element, 8...Differential amplifier, 10...Light source. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A constant temperature bath that maintains the temperature at a predetermined value, a holder for placing a sample placed in the constant temperature bath via a heat leak type thermoelectric element, and a sample placed on the holder. A photochemical reaction heat measuring device comprising means for irradiating a sample with radiation, and means for measuring the amount of heat conducted through the thermoelectric element based on the output from the thermoelectric element. 2 The thermoelectric elements are configured as a pair, and one thermoelectric element is provided with the sample mounting holder, the other thermoelectric element is provided with a reference holder, and the output of each thermoelectric element is input to a differential amplifier. A photochemical reaction heat measuring device according to claim 1, characterized in that the photochemical reaction heat measuring device is configured as follows.