JP2009063358A - Measuring method of resin-curing shrinkage factor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring method of a resin-curing shrinkage factor which enables easy confirmation of curing behavior, from a stage for selecting resin material by reduced labor. <P>SOLUTION: A resin 20 to be measured is housed in a sealed hermetically closed container 12 which is equipped with a pressure sensor 16 and a temperature sensor 18 in a state where air 22 is made stagnant. Thereafter, the pressure and temperature of the air 22 are measured respectively continuously, until a predetermined time is elapsed while heating the hermetically closed container 12 in a hermetically closed state, and the volume (AV2) with the lapse of time of the air 22 is successively calculated from the respective measured values of the initial pressure (P1), volume (AV1) and temperature (T1) of the air 22 and the pressure (P2) and temperature (T2) with the lapse of time of the air 22. Next, the volume (RV2) of the lapse of time of the resin 20 to be measured is calculated, from the difference between the overall volume in the hermetically closed container 12 and the volume (AV2) with the lapse of time of the air 22, and the volume shrinkage factor with the lapse of time of the resin 20 to be measured is determined by using the initial volume (RV1) of the resin 20 to be measured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for measuring the curing shrinkage rate of a resin, which measures the curing shrinkage rate while observing the curing behavior of a thermosetting resin.

  For resin products in which dimensional stability after curing is important, such as thermosetting resins such as epoxy resins and phenolic resins, it is necessary to confirm the curing behavior in advance from the material selection stage of the resin.

  As for the measurement method of the curing shrinkage rate, a measurement method using the specific gravity difference is known for the already cured material, but the measurement method using a modified pycnometer for the measurement method after mixing the two liquids to cure. There is a way. This measuring method is generally performed through the following steps. That is, in one cup of the two pycnometers, for example, a base resin of epoxy resin and a curing agent are accommodated in a cup to be measured, mixed and deaerated, and then a silicone oil for measuring the volume change amount of the resin is added. inject. Also, only silicone oil is injected into the other cup of the pycnometer. Two cups are assembled and arranged in a pycnometer, placed in a heating tank, and heated for a predetermined time. Monitor the temperature and heating time in each cup while heating. After a predetermined time has elapsed, a desired volume shrinkage is calculated from the difference between the volume change amount of the measured resin in one cup, the volume change amount in the other cup, and the initial volume of the measured resin.

Conventionally, as a method for measuring the curing shrinkage rate of this type of resin, a weighed sample of liquid resin is placed in a sealed container, and the sealed container and the standard container are connected to a pressure gauge using a pipe to reach a standard temperature. After holding, the sealed container and the standard container are heated by a heating tank to cure the liquid resin in the sealed container, and then the sealed container and the standard container are returned to the standard temperature. There is a method for measuring the curing shrinkage rate of a resin in which the volume shrinkage is determined by measuring the pressure difference and then the curing shrinkage rate is measured by taking the ratio with the previously weighed liquid resin amount (see Patent Document 1).
JP 7-333034 A

The above conventional techniques have the following problems to be solved.
The former method for measuring the curing shrinkage of a resin using a pycnometer requires a long time for measurement preparation and is complicated. Another problem is that this change during measurement preparation affects the overall result. For measurement, it is necessary to keep watching the state of change at all times, and excessive time and labor are required. Further, there is a problem that the reading error cannot be ignored at the early stage of change.

  Further, the latter method for measuring the shrinkage of curing of the resin is difficult to confirm the curing behavior of the resin over time because it is taken in and out of the heating tank for temperature control of the sealed container and the standard container during the measurement.

  The present invention has been made to solve the above-described problems, and provides a method for measuring the curing shrinkage of a resin, which can easily confirm the curing behavior from the resin material selection stage with little effort. Objective.

The following configurations are means for solving the above-described problems.
<Configuration 1>
In a sealed container equipped with a pressure sensor and a temperature sensor, the measured resin whose volume shrinkage rate is to be measured is accommodated in a state where air is retained, and then the above-mentioned sealed container is heated in a sealed state, The pressure sensor and the temperature sensor are used to measure the pressure and temperature of the air in the airtight container continuously after the airtight container is sealed until a predetermined time elapses. The measured values of the initial pressure (P1), volume (AV1) and temperature (T1), and the time-dependent pressure (P2) and temperature (T2) of the air are substituted into the following equation (1) and the air Sequentially calculates the numerical value of the volume (AV2) over time,
Next, the numerical value of the volume (RV2) of the measured resin over time is obtained from the numerical difference between the total volume in the sealed container and the volume (AV2) of the air over time, and the initial volume (RV1) of the measured resin is obtained. ), The volumetric shrinkage ratio of the resin to be measured over time is obtained by the following formula (2).
P1 × AV1 / T1 = P2 × AV2 / T2 (1)
Volume shrinkage (%) = (RV1-RV2) / RV1 × 100 (2)

  From the initial stage to the end of a predetermined time by sequentially reading and automatically recording the initial volume data of the measured resin and air and the air pressure and temperature data measured over time by the pressure sensor and temperature sensor. The curing behavior of the resin to be measured can be easily confirmed with little effort. Since time measurement can be performed automatically, the measurement time can be saved and the reading error can be reduced.

<Configuration 2>
The method for measuring the curing shrinkage rate of a resin according to Configuration 1, wherein the sealed container is made of an Invar alloy material.

  Invar alloy material is a low thermal expansion alloy made of nickel and iron. By making the sealed container made of Invar alloy material, the pressure of the air in the sealed container can be measured more accurately.

<Configuration 3>
In the method for measuring the curing shrinkage of a resin according to Configuration 1 or 2, the time-measurement information on the temperature and pressure of air in the sealed container obtained from the pressure sensor and the temperature sensor is monitored. Curing shrinkage measurement method.

  Since time-lapse information on the temperature and pressure of the air in the sealed container is automatically recorded as needed, work after measurement setting can be greatly saved.

  Hereinafter, embodiments of the present invention will be described in detail for each example.

1A and 1B are explanatory diagrams of a method for measuring the curing shrinkage rate of a resin in Example 1. FIG. 1A is a cross-sectional view showing a state before the start of measurement, and FIG. 1B is a cross-sectional view showing a state during measurement.
When executing this method for measuring the cure shrinkage rate of a resin, a measuring apparatus 10 shown in FIG. The measuring apparatus 10 includes a sealed container 12 having an open top surface, a lid 14 that seals the sealed container 12, and a pressure sensor 16 and a temperature sensor 18 that detect the pressure and temperature of air in the sealed container 12. .

  The sealed container 12 is made of an Invar alloy material. The Invar alloy material is a low thermal expansion alloy, and the pressure of the air 22 in the sealed container 12 can be continuously measured more accurately. Each of the pressure sensor 16 and the temperature sensor 18 includes a mechanism capable of detecting the pressure and temperature of air and electrically outputting them. It is preferable to use a thermocouple as the temperature sensor 18.

  First, an initial volume (RV1) of a resin 20 to be measured, which is a thermosetting resin such as an epoxy resin or a phenol resin, and the cure shrinkage rate of which is to be obtained is measured and recorded in advance. After the volume measurement, the measured resin 20 is accommodated in the sealed container 12 and sealed with the lid 14. At this time, air 22 stays in the upper part of the sealed container 12. The initial pressure (P1), volume (AV1) and temperature (T1) of the air 22 are also measured and recorded in advance. The initial volume (AV1) of the air 22 can be obtained by subtracting the initial volume (RV1) of the resin to be measured from the total volume in the sealed container.

  The sealed container 12 in a sealed state is accommodated in a suitable heating tank (not shown) and heated. While the hermetic container 12 is heated in the heating tank, the pressure and temperature of the air 22 are respectively measured over time using the pressure sensor 16 and the temperature sensor 18. This time-lapse measurement is continuously performed for a predetermined time, that is, until the resin 20 to be measured reaches a predetermined curing shrinkage as shown in FIG.

  Since the initial pressure (P1), volume (AV1) and temperature (T1) of the air 22 in the sealed container 12 and the measured values of the pressure (P2) and temperature (T2) over time of the air 22 are known, boil The time-dependent volume (AV2) of the air 22 in the hermetic container 12 is sequentially calculated using the equation of state of gas according to Charles' law "P1 * AV1 / T1 = P2 * AV2 / T2."

  Next, since the time-dependent volume (RV2) of the measured resin 20 can be obtained from the difference between the total volume in the sealed container 12 and the time-dependent volume (AV2) of the air 22, the initial volume (RV1) of the measured resin 20 is obtained. ), The volumetric shrinkage ratio of the resin 20 to be measured over time can be obtained from the formula: “volumetric shrinkage ratio (%) = (RV1−RV2) / RV1 × 100”.

Here, FIG. 2 shows the results of measuring the volume shrinkage using 30.15 g of epoxy resin using a sealed container having a total volume of 30.000 cm ^{3 in} the container.
FIG. 2 shows the volume shrinkage obtained from the measured values obtained as follows. That is, first, the initial temperature (T1) of the air in the sealed container containing the epoxy resin, the initial pressure (P1) of the air, the initial volume (AV1) of the air, and the epoxy resin The initial volume (RV1) was measured and recorded. Next, the sealed container containing the epoxy resin was heated in a heating tank. After the start of heating, the temperature (T2) and pressure (P2) of the same air every 30 minutes, 1 hour, 1 hour 30 minutes, 2 hours, 3 hours 30 minutes, 18 hours, 21 hours 30 minutes Was measured over time. Then, the time-dependent volume (AV2) of the air in the sealed container is sequentially calculated by the above-described formula “P1 × AV1 / T1 = P2 × AV2 / T2”, and the total volume in the container (30.000 cm ³ ) Each volume (RV2) of the epoxy resin over time is obtained from the difference from each volume of air over time (AV2), and the above formula “volume shrinkage (%) = (RV1−RV2) / RV1 × 100” Each volume shrinkage over time was determined.

  By sequentially reading and automatically recording the initially set volume value data and the pressure value and temperature value data measured by the pressure sensor 16 and the temperature sensor 18, the confirmation of the curing behavior is performed sequentially from the initial stage of resin material selection. Can do. It is possible to save the measurement time and reduce the reading error.

  By monitoring the temperature and pressure aging information in the sealed container 12 obtained from the pressure sensor 16 and the temperature sensor 18, the temperature and pressure aging information in the sealed container 12 is recorded as needed. Subsequent work can be greatly saved.

It is explanatory drawing of the cure shrinkage rate measuring method of resin of Example 1. FIG. It is a figure which shows the measurement result of the volumetric shrinkage rate of an epoxy resin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Measuring apparatus 12 Airtight container 14 Lid 16 Pressure sensor 18 Temperature sensor 20 Resin 22 to be measured Air

Claims (3)

In a sealed container equipped with a pressure sensor and a temperature sensor, the resin to be measured whose volume shrinkage rate is to be measured is stored in a state where air is retained,
Thereafter, while the sealed container is heated in a sealed state, the pressure of the air in the sealed container is measured using the pressure sensor and the temperature sensor until a predetermined time elapses after the sealed container is sealed. Measure each temperature continuously,
The measured values of the initial pressure (P1), volume (AV1) and temperature (T1) of the air in the sealed container, and the time-dependent pressure (P2) and temperature (T2) of the air are expressed by the following equation (1). And the numerical value of the volume of air over time (AV2) is sequentially calculated,
Next, a numerical value of the volume (RV2) of the measured resin over time is obtained from a numerical difference between the total volume in the sealed container and the volume (AV2) of the air with time, and an initial volume (RV1) of the measured resin is obtained. ) Is used to determine the volumetric shrinkage ratio of the measured resin over time according to the following equation (2).
P1 × AV1 / T1 = P2 × AV2 / T2 (1)
Volume shrinkage (%) = (RV1-RV2) / RV1 × 100 (2) In the method for measuring the curing shrinkage of the resin according to claim 1,
The method for measuring a curing shrinkage rate of a resin, wherein the sealed container is made of an Invar alloy material. In the method for measuring the curing shrinkage of the resin according to claim 1 or 2,
A method for measuring a curing shrinkage rate of a resin, comprising monitoring time-lapse information of temperature and pressure in the sealed container obtained from the pressure sensor and the temperature sensor.

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