JP6950494B2 - Method for quantifying resin components - Google Patents

Description

The present invention relates to a method for quantifying a resin component.

In personal computers and mobile phones, for example, various electronic components such as multilayer chip capacitors and chip resistors are used. Conductors, resistors, insulators, and the like in these electronic components are formed using, for example, a paste for electronic components. The paste for electronic parts is made by kneading and dispersing an inorganic powder such as a metal powder, a glass powder and an inorganic oxide in an organic solvent to form a paste. There are conductor pastes containing Cu and the like, resistance pastes containing Ru and the like as resistance materials, and insulating pastes used for protective films of circuits and the like.

Since the paste is screen-printed as a pattern of a circuit or the like on a ceramic substrate or a green sheet, for example, a resin component is usually blended in addition to an additive such as an inorganic powder. As the resin component, a binder resin is blended for the purpose of ensuring adhesion to the substrate after drying and curing, and a vehicle resin is blended for the purpose of dispersing and supporting the inorganic powder in the paste. Plays a very important role in paste. Therefore, in the quality control of the paste and the analysis of the cause of the quality trouble, it is important to quantify the content of each of the plurality of resin components constituting the resin component in the paste.

As a method for quantifying the resin component, for example, there is gel permeation chromatography (GPC) (see, for example, Patent Document 1). GPC is a type of liquid chromatography that separates based on the difference in molecular size, and molecules with a high molecular weight move and elute in a column faster than molecules with a low molecular weight. Therefore, the resin component having a small molecular weight and the resin component having a large molecular weight can be separated from each other, and the resin component can be quantified from the peak area of the obtained chromatogram.

Another quantification method is, for example, thermogravimetric analysis (TG) (see, for example, Patent Document 2). TG can measure the weight change when the resin component is heated and thermally decomposed, and can calculate the content of each resin component.

Japanese Unexamined Patent Publication No. 2008-63457 Japanese Unexamined Patent Publication No. 2013-195391

However, in GPC, when the molecular weights of the plurality of resin components blended in the paste are about the same, there is no difference in the molecular weights, so that it is difficult to quantify each resin component individually. Similarly, in TG, when the thermal decomposition temperatures of the plurality of resin components are close to each other, there is no difference in the weight change due to the thermal decomposition, so that it is difficult to quantify them individually.

The present invention has been made in view of the above problems, and even when a plurality of resin components contained in the paste have the same molecular weight and thermal decomposition temperature, the content of each resin component is individually quantified. The purpose is to provide the technology to do.

The present inventor investigated a method capable of individually quantifying the contents of a plurality of resin components contained in a paste, and focused on pyrolysis gas chromatography. Pyrolysis gas chromatography quantifies the content of each resin component by thermally decomposing a mixture of a plurality of resin components and obtaining the peak area value of the pyrolysis product peculiar to each resin component from the obtained chromatogram. can do. Moreover, the combination of a plurality of resin components is not particularly limited, and even a combination of resin components having similar molecular weights and thermal decomposition temperatures can be separated and quantified. However, according to the study of the present inventor, when the paste for electronic parts containing inorganic powder, particularly metal powder, is measured by pyrolysis gas chromatography, each resin component can be quantified individually, but each quantified value cannot be accurately obtained. Was confirmed. This is because the inorganic powder exhibits a catalytic reaction during thermal decomposition, which changes the reaction efficiency and reaction mechanism of the thermal decomposition of the resin component, and the amount of thermal decomposition products unique to the resin component greatly fluctuates. It is thought that this is because it ends up. From this, it was found that when quantifying each resin component in the paste for electronic parts, it is better to remove the inorganic powder from the paste in advance, instead of measuring the paste as it is by pyrolysis gas chromatography. The present invention has been made based on the above findings and is as follows.

That is, the first aspect of the present invention is
It is a quantification method for individually quantifying the content of each resin component in a paste containing a plurality of resin components and an inorganic powder.
A dissolution step of mixing the paste and an organic solvent to dissolve the plurality of resin components, and
A separation step of separating the inorganic powder from the solution obtained in the dissolution step to form a resin solution containing the plurality of resin components, and a separation step.
A measurement step in which the resin solution is measured by pyrolysis gas chromatography to obtain a peak area value of a pyrolysis product peculiar to each resin component generated by thermal decomposition of each resin component.
For each resin component, a quantification step of calculating the content in the paste from the peak area value obtained in the measurement step based on a calibration curve showing the correlation between the content and the peak area value of the unique pyrolysis product. A method for quantifying a resin component having the above is provided.

A second aspect of the present invention is, in the first aspect,
Between the separation step and the measurement step, there is a drying step of drying the resin solution to volatilize the organic solvent to form a dry solid containing the plurality of resin components.
In the measurement step, the dry matter is measured by pyrolysis gas chromatography.

A third aspect of the present invention is, in the first or second aspect,
The organic solvent is a component that does not generate the same thermal decomposition product as the thermal decomposition product peculiar to each resin component generated in the measurement step by thermal decomposition.

A fourth aspect of the present invention is the first to third aspects.
In the separation step, the inorganic powder and the resin solution are centrifuged.

A fifth aspect of the present invention is
It is a quantification method for individually quantifying the content of each resin component in a paste containing a plurality of resin components and an inorganic powder.
Provided is a method for quantifying a resin component, which separately quantifies each content of the plurality of resin components by separating the inorganic powder from the paste and measuring the plurality of resin components by thermal decomposition gas chromatography. ..

According to the present invention, even when a plurality of resin components contained in the paste have the same molecular weight and thermal decomposition temperature, the content of each resin component can be individually quantified.

FIG. 1 is a calibration curve showing the correlation between the content of the resin A in Example 1 and the peak area value of the thermal decomposition product A, which is a unique thermal decomposition product. FIG. 2 is a calibration curve showing the correlation between the content of the resin B in Example 1 and the peak area value of the pyrolysis product B, which is a unique pyrolysis product.

<One Embodiment of the present invention>
Hereinafter, a method for quantifying the resin component according to the embodiment of the present invention will be described. The method for quantifying the resin component of the present embodiment includes a preparation step, a dissolution step, a separation step, a drying step, a measurement step, and a quantification step. Hereinafter, each step will be described in detail.

(Preparation process)
First, a paste containing a plurality of resin components and an inorganic powder is prepared. The type of the paste that can be applied to the quantification method of the present embodiment is not particularly limited as long as it contains a plurality of resin components and an inorganic powder. For example, gold paste, silver paste, palladium paste, copper paste, carbon paste, ruthenium oxide paste, glass paste, solder paste and the like can be mentioned.

(Melting process)
Subsequently, the paste is added to the organic solvent to dissolve the plurality of resin components. This makes it easier to separate the inorganic powder in the separation step described later.

The organic solvent should be one that can dissolve the resin component to be quantified and does not interfere with the pyrolysis product derived from the resin component when measured by pyrolysis gas chromatography in the measurement step described later. For example, there is no particular limitation. That is, as the organic solvent, it is preferable to use a component that does not generate the same thermal decomposition product as the thermal decomposition product unique to each resin component generated in the measurement step described later by thermal decomposition. For example, tetrahydrofuran, chloroform and the like can be used.

When the paste contains a resin component having an ionic functional group, such a resin component may be adsorbed on the surface of the inorganic powder (particularly the metal powder) by ionic interaction. Therefore, a small amount of an acid such as hydrochloric acid may be added for the purpose of separating these resin components from the inorganic powder.

(Separation process)
Subsequently, the inorganic powder is separated from the solution containing the inorganic powder obtained in the dissolution step. As a result, a resin solution in which a plurality of resin components are dissolved in an organic solvent is obtained.

The method for separating the inorganic powder is not particularly limited, and for example, centrifugation, filtration separation, or the like can be used. In the case of centrifugation, the resin solution is transferred to a centrifuge tube and subjected to a centrifuge to precipitate the inorganic powder, thereby separating the inorganic powder and the resin solution. In the case of filtration separation, the solution containing the inorganic powder is passed through a filter, the inorganic powder is captured by the filter, and the resin solution and the inorganic powder are separated. In the case of filtration separation, if the molecular weight of the resin component is high, it may be captured by the filter, so it is advisable to change the filtration method according to the molecular weight of the resin component. Centrifugation is preferable from the viewpoint of easily and more reliably separating the resin solution and the inorganic powder.

(Drying process)
Subsequently, the resin solution obtained in the separation step is dried to volatilize the organic solvent to form a dry solid product containing a plurality of resin components. When the resin solution is measured as it is by pyrolysis gas chromatography without volatilizing the organic solvent, depending on the type of the organic solvent, the pyrolysis gas chromatography is used to determine the unique thermal decomposition products derived from a plurality of resin components to be quantified. This is because the same thermal decomposition product as that of the above may be generated, and the quantitative value of each resin component may be changed. On the other hand, by volatilizing the organic solvent to form a dry matter, it is possible to suppress fluctuations in the quantitative value depending on the organic solvent. That is, by providing the drying step, each resin component can be quantified more accurately.

The drying method is not particularly limited, and for example, the resin solution may be heated at a temperature equal to or higher than the boiling point of the organic solvent and lower than the thermal decomposition temperature of each resin component.

(Measurement process)
Subsequently, a dry matter containing a plurality of resin components is measured by thermal decomposition gas chromatography to obtain a gas chromatogram. Since each resin component produces one or more pyrolysis products by thermal decomposition, when a plurality of resin components are measured by thermal decomposition gas chromatography, the obtained chromatogram shows a plurality of thermal decompositions derived from the plurality of resin components. The peak of the product will be detected. For example, when a component containing a resin X that produces thermal decomposition products a and b by thermal decomposition and a resin Y that produces thermal decomposition products b and c is measured by thermal decomposition gas chromatography, the obtained chromatogram shows thermal decomposition. Multiple peaks of products a to c will be detected.

Then, from the obtained chromatogram, the peak area value of the thermal decomposition product peculiar to each resin component generated by the thermal decomposition of each resin component is obtained. Specifically, when a plurality of different resin components are thermally decomposed, the same thermal decomposition product may be produced even if the resin components are different, and the peak of the thermal decomposition product common to the different resin components. Therefore, it is not possible to evaluate a plurality of different resin components individually. For example, since both the resin X and the resin Y described above generate the thermal decomposition product b, the total content of these resin components is quantified from the peak area value of the thermal decomposition product b, and they are individually used. Cannot be quantified. On the other hand, by paying attention to the peak of the thermal decomposition product peculiar to each resin component, a plurality of resin components can be individually quantified. For example, by paying attention to the peak of the thermal decomposition product a for the resin X and the peak of the thermal decomposition product c for the resin Y, each resin component can be individually quantified from these area values.

(Quantitative process)
Subsequently, the content of each resin component is calculated from the peak area value of the thermal decomposition product peculiar to each resin component obtained in the measurement step using the calibration curve prepared in advance.

The calibration curve shows the correlation between the content of the resin component and the peak area value of the thermal decomposition product peculiar to the content, and is created for each of the plurality of resin components contained in the paste in the present embodiment. Specifically, first, a resin solution containing a resin component having a known content is prepared as a standard solution. Next, by measuring this standard solution by pyrolysis gas chromatography, the peak area value of the pyrolysis product peculiar to the resin component is obtained. In addition, the content of the resin component is changed stepwise, and the peak area value of the thermal decomposition product at each content is obtained. Then, a calibration curve is created by plotting the amount of change in the peak area value of the thermal decomposition product peculiar to the resin component with respect to the content of the resin component.

In the quantification step, the peak area value of the thermal decomposition product peculiar to each resin component obtained in the measurement step is compared with the corresponding calibration curve, and the content of each resin component is calculated. In the present embodiment, since the peak area value of the thermal decomposition product shows a value peculiar to each of the plurality of resin components, each resin component can be quantified individually.

The detector used in the pyrolysis gas chromatography may be any detector as long as it can detect the target component, but since there are various components in the pyrolysis product of the polymer, it is selective. High, the use of mass spectrometers is desirable.

When the types of the plurality of resin components contained in the paste are unknown, it is advisable to specify the types of the plurality of resin components by a known qualitative analysis method in advance before the dissolution step.

<Effect of this embodiment>
According to this embodiment, one or more of the following effects are exhibited.

In the present embodiment, the paste containing the plurality of resin components and the inorganic powder is not measured as it is by pyrolysis gas chromatography, but is measured after the paste is dissolved in an organic solvent to separate the inorganic powder. As a result, the catalytic reaction due to the inorganic powder can be suppressed during the thermal decomposition of the resin component, and the fluctuation in the amount of the thermal decomposition product derived from each resin component can be reduced, so that the resin component can be accurately quantified. .. Moreover, for each of the plurality of resin components, the peak area value of the thermal decomposition product peculiar to each resin component is obtained, and the content of each resin component is calculated using the calibration curve to obtain the content of each resin component. Can be quantified individually. Therefore, according to the method for quantifying the resin component of the present embodiment, a plurality of resin components contained in the paste can be accurately and individually quantified.

Further, in GPC and TG, if the molecular weights and thermal decomposition temperatures of a plurality of resin components are the same, they cannot be individually quantified, but in the present embodiment, each resin component is unique by thermal decomposition gas chromatography. Since the measurement is based on the thermal decomposition product, each resin component can be quantified individually.

Further, in the present embodiment, it is preferable to provide a drying step of drying the resin solution between the separation step and the measurement step, and to measure using a dry solid product obtained by drying the resin solution in the measurement step. By volatilizing the organic solvent by drying in advance before the measurement step, the generation of pyrolysis products derived from the organic solvent is suppressed when measuring by pyrolysis gas chromatography, and the content of each resin component is further increased. A chromatogram that accurately reflects the results can be obtained, and each resin component can be quantified more accurately.

Further, as the organic solvent for dissolving the paste, it is preferable to use a component that does not generate the same thermal decomposition product as the thermal decomposition product peculiar to the plurality of resin components contained in the paste by thermal decomposition. According to such an organic solvent, when the inorganic powder is separated from the dissolved paste to form a resin solution, even if the resin solution is measured as it is by pyrolysis gas chromatography, the content of each resin component is individually determined. And can be accurately quantified.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples. In this example, a paste having a known resin component content was prepared, the paste was quantified, and the accuracy of the quantification was evaluated by comparing the actual content with the content obtained by the measurement. ..

The pastes analyzed in this example include metal powders having an average particle size in the range of 0.05 μm to 5.0 μm, resins A and B having an average molecular weight in the range of 50,000 to 100,000, and resins. A metal paste containing an organic solvent in a predetermined content (preparation amount) was prepared.

(Example 1)
0.2 g of the metal paste was collected in a 10 mL glass vial, 10 mL of tetrahydrofuran as an organic solvent was added thereto, and the mixture was shaken for 30 minutes to dissolve the resin A and the resin B in the metal paste in tetrahydrofuran. 1.5 mL of this solution was collected in a centrifuge tube, set in a centrifuge, and centrifuged at a centrifugal force of 10000 G for 15 minutes to precipitate a metal powder. 10 uL of the supernatant of the obtained solution was collected with a microsyringe to obtain a resin solution in which resin A and resin B were dissolved. This resin solution was transferred to a sample cup for a pyrolysis gas chromatograph. The sample cup was heated at 70 ° C. to volatilize tetrahydrofuran, and then set in a pyrolysis gas chromatograph mass spectrometer for measurement. Table 1 below shows the device configuration and measurement conditions of the pyrolysis gas chromatograph mass spectrometer used in this example.

From the obtained chromatogram, the peak area value of the unique pyrolysis product A derived from the resin A and the peak area value of the unique pyrolysis product B derived from the resin B were obtained.

Then, using the calibration curve shown in FIGS. 1 and 2, the content of each resin component contained in the paste was calculated individually. FIG. 1 is a calibration curve showing the correlation between the content of the resin A in Example 1 and the peak area value of the unique pyrolysis product A, with the horizontal axis representing the content [μg] and the vertical axis representing the peak. The area value (strength) is shown respectively. FIG. 2 is a calibration curve showing the correlation between the content of the resin B in Example 1 and the peak area value of the unique pyrolysis product B, with the horizontal axis representing the content [μg] and the vertical axis representing the peak. The area value (strength) is shown respectively. These calibration curves were prepared by measuring in advance by pyrolysis gas chromatography using a tetrahydrofuran solution containing resin A and resin B having known concentrations in the same manner as described above.

It was confirmed that the content of each resin component calculated using the calibration curve was 1.06 times the original content of the resin A and 1.17 times the original content of the resin B. .. That is, it was confirmed that the content of each resin obtained by the measurement was close to the original content, and the content of each resin component could be quantified accurately and individually.

(Comparative Example 1)
In Comparative Example 1, a quantitative analysis was carried out in the same manner as in Example 1 except that the operation of precipitating and separating the metal powder by centrifugation was omitted. As a result, it was confirmed that the calculated content of each resin component was 2.06 times the original content of the resin A and 1.33 times the original content of the resin B. That is, when the metal powder was measured by pyrolysis gas chromatography without separation, it was confirmed that the quantitative value of the resin A was considerably larger than the original content and could not be accurately quantified. It is considered that this is because the thermal decomposition product A was generated from other than the resin A because the efficiency of the thermal decomposition reaction and the decomposition reaction mechanism of the resin component changed due to the catalytic activity of the metal powder coexisting during the thermal decomposition. ..

When the paste is measured by GPC, the average molecular weight of the resin A and the resin B is in the range of 50,000 to 100,000, but since the difference in the average molecular weight is small, each resin component cannot be quantified individually. Has been confirmed.

As described above, the content of each resin component can be individually and accurately quantified by separating the inorganic powder before measuring the paste containing a plurality of resin components and the inorganic powder by pyrolysis gas chromatography. can.

Claims (3)

It is a quantification method for individually quantifying the content of each resin component in a paste containing a plurality of resin components and an inorganic powder.
A dissolution step of mixing the paste and an organic solvent to dissolve the plurality of resin components, and
A separation step of separating the inorganic powder from the solution obtained in the dissolution step to form a resin solution containing the plurality of resin components, and a separation step.
A measurement step in which the resin solution is measured by pyrolysis gas chromatography to obtain a peak area value of a pyrolysis product peculiar to each resin component generated by thermal decomposition of each resin component.
For each resin component, and quantification step of calculating the amount of the paste from the content and on the basis of a calibration curve showing the correlation between the peak area value of the intrinsic thermal decomposition products, the measured peak area values obtained in step ,
Between the separation step and the measurement step, the resin solution is heated at a temperature equal to or higher than the boiling point of the organic solvent and lower than the thermal decomposition temperature of the plurality of resin components and dried to volatilize the organic solvent. A drying step of forming a dry solid containing the plurality of resin components.
In the measurement step, the dry matter is measured by pyrolysis gas chromatography.
Method for quantifying resin components. The quantification of the resin component according to claim 1 , wherein the organic solvent is a component that does not generate the same thermal decomposition product as the thermal decomposition product peculiar to each resin component generated in the measurement step by thermal decomposition. Method. In the separation step, the inorganic powder and the resin solution are centrifuged.
The method for quantifying a resin component according to claim 1 or 2.

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