Evaluation method for dispersion state of filler aggregate in rubber

Abstract

To provide an evaluation method for a dispersion state of a filler aggregate in rubber, capable of accurately grasping a dispersion state of a filler aggregate in unvulcanized rubber.SOLUTION: Scattering profile data 20 of a plurality of samples 10 having different volume fractions φ of a filler is subjected to data processing by an arithmetic device 3 to generate filler scattering profile data 21 extracted from the scattering profile data of a filler aggregate in all of the samples 10. For each sample 10, dispersion profile data 30 indicating a relation between a scattering intensity ratio S(q) and a scattering vector q, calculated based on the scattering profile data 20 and the filler scattering profile data 21 is generated to evaluate a dispersion state of the filler aggregate in each sample 10 on the basis of each generated dispersion data 30.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating the dispersion state of filler agglomerates in rubber, and more particularly to a method for evaluating the dispersion state of filler agglomerates in rubber that can accurately grasp the dispersion state of filler agglomerates in vulcanized rubber. [Background technology]

[0002] Rubber products such as tires and conveyor belts contain fillers such as carbon black and silica. The dispersion state of filler agglomerates in rubber affects the performance of rubber products. Therefore, a method for appropriately evaluating the dispersion state of filler agglomerates in rubber is needed.

[0003] A method has been proposed in which silica-blended vulcanized rubber and this vulcanized rubber swollen with a solvent are used as measurement materials, scattering intensity curves are obtained from each measurement material by X-ray scattering measurement, and the dispersion of silica aggregates is evaluated using the ratio between the scattering intensity curve of the unswollen silica-blended rubber and the scattering intensity curve of the silica-blended rubber swollen with a solvent, corrected for the swelling degree (see Patent Document 1).The method proposed in Patent Document 1 quantifies only the dispersion of silica aggregates in the silica-blended rubber by taking advantage of the fact that information on the dispersion of filler aggregates in the swollen silica-blended rubber, S(q), as approximately 1.

[0004] However, this method uses silica-blended rubber swollen with a solvent as the measurement material, which results in variations in the degree of swelling, which in turn changes the scattering intensity measurement results.Therefore, there is room for improvement in accurately grasping the dispersion state of silica aggregates. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-179643 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a method for evaluating the dispersion state of filler agglomerates in rubber, which enables accurate understanding of the dispersion state of filler agglomerates in vulcanized rubber. [Means for solving the problem]

[0007] The method for evaluating the dispersion state of filler agglomerates in rubber of the present invention, which achieves the above-mentioned object, uses a vulcanized rubber containing a filler as a sample, acquires scattering profile data of the sample by measurement using an X-ray scattering method or a neutron scattering method, and uses the acquired scattering profile data to evaluate the dispersion state of filler agglomerates in rubber, wherein the method is characterized in that: a plurality of vulcanized rubbers having different filler volume fractions are used as the samples, acquires the scattering profile data for each of the vulcanized rubbers, and processes each of the scattering profile data using a computing device to generate filler scattering profile data extracted from the scattering profile data of the filler agglomerates in all of the samples using the relationship between the reciprocal of the scattering intensity for each scattering vector in each of the scattering profile data and each of the volume fractions; calculates a scattering intensity ratio for each of the samples based on the acquired scattering profile data and the filler scattering profile data; generates dispersion profile data showing the relationship between the scattering intensity ratio and the scattering vector; and evaluates the dispersion state of the filler agglomerates in each of the samples based on the generated dispersion profile data. [Effects of the Invention]

[0008] According to the present invention, by using a plurality of vulcanized rubbers having different filler volume fractions as samples, it is possible to utilize the relationship between the reciprocal of the scattering intensity for each scattering vector and the filler volume fraction, and to generate the dispersion profile data that represents the dispersion state of the filler agglomerates in each sample. Therefore, the generated dispersion profile data can be used to accurately grasp the dispersion state of the filler agglomerates in each sample. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram illustrating an evaluation system. [Figure 2] FIG. 1 is a flow chart illustrating the procedure of an embodiment of a method for evaluating the dispersion state of filler agglomerates in rubber. [Figure 3] FIG. 10 is a graph illustrating the scattering profile data of each sample. [Figure 4] FIG. 10 is a graph illustrating the relationship between the inverse of the scattering intensity for each scattering vector and the volume fraction. [Figure 5] 10A and 10B are graphs illustrating scattering profile data of each sample and filler scattering profile data. [Figure 6] 1 is a graph illustrating dispersion profile data for each sample. FIG. [Figure 7] FIG. 10 is a graph illustrating the average inter-aggregate distances for each sample calculated in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the method of the present invention for evaluating the dispersion state of filler aggregates in rubber will be described based on the embodiment shown in the drawings.

[0011] The evaluation system 1 shown in Fig. 1 is used to carry out a method for evaluating the dispersion state of filler agglomerates in rubber. In this evaluation method, first, a plurality of samples 10 containing different volume fractions of filler blended into vulcanized rubber are prepared, and scattering profile data 20 of each sample 10 is obtained by X-ray scattering measurement using an X-ray scattering device 2. Next, each scattering profile data 20 is processed by a computing device 3 to generate dispersion profile data 30 for each sample 10, as shown in Fig. 6, which will be described later, and the generated dispersion profile data 30 is used to evaluate the dispersion state of filler agglomerates in each sample 10.

[0012] First, the evaluation system 1 will be described.

[0013] The evaluation system 1 includes an X-ray scattering device 2 and a computing device 3. Various data are input and stored in the computing device 3, and data processing is performed using this data. Various known computers can be used as the computing device 3. The computing device 3 has a central processing unit (CPU) 4, a main storage unit (memory) 5, an auxiliary storage unit (e.g., HDD) 6, an input unit (keyboard, mouse) 7, and an output unit (display) 8. The auxiliary storage unit 6 stores a plurality of scattering profile data 20 acquired by the X-ray scattering device 2.

[0014] The X-ray scattering device 2 can be any of various known X-ray scattering devices capable of small-angle X-ray scattering (SAXS) or ultra-small-angle X-ray scattering (USAXS) measurements. In small-angle X-ray scattering measurements, the scattering angle θ is set to a small angle range of 0.1°<2θ<10°, and the X-ray scattering intensity I(q) is measured for each region of different electron density having a size of about 1 to 100 nm present in the sample 10. In ultra-small-angle X-ray scattering measurements, the scattering angle θ is set to an ultra-small angle range of 0°<2θ≦0.1°, and the X-ray scattering intensity I(q) is measured for each region of different electron density having a size of about 1 to 1000 nm present in the sample 10. The X-ray scattering device 2 can be a small laboratory-level device or a large device used in a large facility.

[0015] In the evaluation system 1, when a plurality of scattering profile data 20 acquired by the X-ray scattering device 2 is input to the calculation device 3 and a predetermined program is started and executed by the input unit 7, the calculation device 3 executes each data processing instructed by the program. Then, the calculation device 3 executes each data processing and outputs the evaluation results obtained to the output unit 8. If the plurality of scattering profile data 20 is stored in the calculation device 3, the evaluation system 1 does not need to include the X-ray scattering device 2.

[0016] Next, the procedure for evaluating the dispersion state of filler agglomerates in rubber will be described.

[0017] As shown in FIG. 2, in this evaluation method, first, a plurality of samples 10 are prepared, each having a different filler volume fraction φ [vol %] in the vulcanized rubber (S110). The filler volume fraction φ is the ratio of the filler volume to the total volume of the components that make up the vulcanized rubber before mixing. Next, scattering profile data 20 of each sample 10 is acquired by an X-ray scattering device 2 (S120). Next, the acquired scattering profile data 20 is processed by a computing device 3 to evaluate the dispersion state of filler aggregates in the sample 10 (S130, S140). Each step (S110 to S140) will be described in detail below.

[0018] In step (S110), a plurality of samples of the same vulcanized rubber are produced with different filler volume fractions φ in the vulcanized rubber, with only the amount of filler being substantially different, and each of the produced samples is used as sample 10. The same vulcanized rubbers have substantially the same compounding ingredients (types of rubber components and additives) except for the filler component, and the production conditions, such as mixing conditions (mixing temperature, mixing time, rotor rotation speed in the kneading mixer, temperature of the unvulcanized rubber when discharged from the kneading mixer, etc.) and vulcanization conditions (vulcanization temperature, vulcanization pressure, vulcanization time, etc.), are also substantially the same. The number of types of samples (samples 10) prepared with different filler volume fractions φ is, for example, three or more.

[0019] The vulcanized rubber used in sample 10 is produced by vulcanizing unvulcanized rubber blended with fillers such as carbon black, silica, and calcium carbonate. The rubber component of the vulcanized rubber may be any rubber component that can be vulcanized with a vulcanizing agent, such as natural rubber (NR) or synthetic rubbers such as styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR). The vulcanizing agent (crosslinking agent) may be any agent that can vulcanize (crosslink) the molecular chains of the linear polymer of the rubber component, such as organic peroxides and sulfur. In addition to the vulcanizing agent and filler, the vulcanized rubber may also contain various known compounding agents such as coupling agents, vulcanization accelerators, antioxidants, flame retardants, reinforcing materials, and colorants.

[0020] When varying the amount of filler in the same vulcanized rubber, if silica is used as the filler, the amount of coupling agent is also varied depending on the amount of filler. Therefore, samples 10 with different volume fractions φ of the silica filler also differ in the amount of coupling agent in addition to the filler. In the present invention, samples 10 are used that differ substantially in the amount of filler alone, rather than samples 10 that strictly differ in the amount of filler alone.

[0021] In this step (S110), multiple types of samples 10 that differ substantially only in the filler volume fraction φ are treated as one set. When it is desired to evaluate the dispersion state of filler agglomerates in a desired vulcanized rubber, one set is made up of sample 10 of the desired vulcanized rubber and one or more other types of samples 10 that differ substantially from sample 10 in the amount of filler blended. When it is desired to evaluate the dispersion state of filler agglomerates in a desired vulcanized rubber due to differences in manufacturing conditions such as mixing conditions and vulcanization conditions, one set is made up of sample 10 of the desired vulcanized rubber and one or more other types of samples 10 that differ substantially from sample 10 in the amount of filler blended, and one or more other sets of samples 10 manufactured under manufacturing conditions different from those of the first set of samples 10.

[0022] The filler volume fraction φ of each sample 10 can be selected arbitrarily, but it is preferable that each sample 10 includes a sample 10 with a filler volume fraction φ of less than 10 vol%, and more preferably a sample 10 with a volume fraction φ of 1 vol% or more and 5 vol% or less. By preparing a sample 10 with a filler volume fraction φ closer to 0 vol%, and using the dispersion state of the filler agglomerates in that sample 10 as a reference, it is possible to understand the change in the dispersion state of the filler agglomerates due to an increase in the filler volume fraction φ.

[0023] In this embodiment, four types of samples with different filler volume fractions φ were produced under substantially the same formulation and production conditions except for the filler volume fraction φ, and thin sections were cut from each sample using a known ultramicrotome, and the thin sections were used as samples 10. The filler volume fractions φ in each sample 10 were, for example, 5 vol%, 10 vol%, 15 vol%, and 20 vol%.

[0024] In step (S120), scattering profile data 20 of each sample 10 is acquired by measurement using small-angle X-ray scattering or ultra-small-angle X-ray scattering with the X-ray scattering device 2. In this step (S120), the X-ray scattering device 2 irradiates each sample 10 with X-rays and obtains a predetermined scattering vector q [nm -1 ], the scattering intensity I(q) [au] of the X-rays appearing in the region [au] is measured to obtain the respective scattering profile data 20. As an example, the scattering profile data 20 is obtained by X-ray scattering measurement using the X-ray scattering device 2, but it can also be obtained by neutron scattering measurement using a neutron scattering device. The scattering vector q is expressed by the following mathematical formula (1), where θ is the scattering angle and λ is the wavelength of the incident ray.

[0025]

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[0026] The scattering profile data 20 of each sample 10 shown in FIG. 3 was created based on the measurement results of the X-ray scattering method using the X-ray scattering device 2. In FIG. 3, the horizontal axis represents the scattering vector q [nm -1 ], and the vertical axis represents the corrected scattering intensity I(q) / φ[au], which is the value obtained by correcting the scattering intensity I(q) obtained by measurement with the volume fraction φ of each sample 10. Although the scattering intensity I(q) obtained by measurement can be used as is on the vertical axis, it is preferable to use the corrected scattering intensity I(q) / φ. By using this corrected scattering intensity I(q) / φ, the scattering profile data 20 shown in the graph of FIG. 3 more clearly shows changes depending on the dispersion state of the filler aggregates. Note that the scattering intensity I(q) obtained by measurement has been corrected for parasitic scattering caused by the sample in the X-ray scattering device 2, the window material of the vacuum tube, air, etc., using various known parasitic scattering correction methods.

[0027] The scattering profile data 20 shown in Fig. 3 is an approximation of a group of points (not shown) plotted at positions corresponding to the scattering vector q and the corrected scattering intensity I(q) / φ for each sample 10. The solid line, dashed line, one-dot chain line, and two-dot chain line in Fig. 3 represent the scattering profile data 20 for samples 10 with filler volume fractions of 5 vol%, 10 vol%, 15 vol%, and 20 vol%, respectively.

[0028] Each scattering profile data 20 has a scattering vector q of 0.01 nm -1 More than 0.2nm -1 The corrected scattering intensity I(q) / φ in the following range is included. The corrected scattering intensity I(q) / φ in this range includes the scattering intensity due to filler aggregates (the filler scattering intensity I agg (q)) is included. Thus, the scattering vector q ranges from 0.01 nm -1 More than 0.2nm -1 Including the following range is advantageous for analyzing the scattering intensity of filler aggregates. Furthermore, in order to measure the scattering intensity I(q) within that range, it is preferable to use small-angle X-ray scattering or ultra-small-angle X-ray scattering in the measurement using the X-ray scattering device 2.

[0029] In step (S130), the calculation device 3 performs data processing to analyze each scattering profile data 20 and generate multiple dispersion profile data 30. Specifically, the calculation device 3 screens (extracts) the scattering profile data of only the filler aggregates in all samples 10 from each scattering profile data 20 to generate filler scattering profile data 21. Next, the calculation device 3 performs the following data processing for each sample 10. First, the calculation device 3 calculates the scattering intensity ratio S(q), which is the ratio of the scattering intensity between the scattering profile data 20 and the filler scattering profile data 21, for each scattering vector (q). Next, the calculation device 3 generates dispersion profile data 30 that indicates the relationship between the scattering intensity ratio S(q) and the scattering vector (q). The calculation device 3 performs the above data processing for each sample 10 to generate dispersion profile data 30 for each sample 10. In screening the filler scattering profile data 21, the relationship between the inverse of the corrected scattering intensity I(q) / φ for each scattering vector q in each scattering profile data 20 and the respective volume fraction φ is utilized.

[0030] The graph shown in Figure 4 shows an example of the relationship between the reciprocal of the corrected scattering intensity I(q) / φ for each scattering vector q and the volume fraction φ. The white circles, white squares, white triangles, and crosses in Figure 4 represent plots of the predetermined scattering vectors q (q1, q2, . . . , q7) and the reciprocal of the corrected scattering intensity (log(φ / I(q))) at the corresponding positions for the scattering profile data 20 of each sample 10 (volume fractions of 5 vol%, 10 vol%, 1 vol%, and 20 vol%). The predetermined scattering vectors q (q1, q2, . . . , q7) are 0.01 nm -1 More than 0.2nm -1The number of predetermined scattering vectors q can be arbitrarily selected from the following range. The number of predetermined scattering vectors q may be, for example, 20 or more. Each curve in FIG. 4 represents a curve approximated for each scattering vector q by classifying the plotted point clouds by scattering vector q (q1, q2, . . . , q7). The thick solid line, thick dashed line, intermediate solid line, intermediate dashed line, dashed-dot line, dashed-two-dot line, and thin solid line in FIG. 4 represent approximate curves for scattering vectors q1, q2, . . . , q7, respectively. From each approximate curve, it can be seen that the reciprocal of scattering intensity I(q) / φ depends on the volume fraction φ, and that this relationship can be expressed as a quadratic function with the volume fraction φ as a variable.

[0031] In generating the filler scattering profile data 21, the filler scattering intensity I agg (q), constants A2 and A3 are calculated. Then, the filler scattering intensity I agg Generate filler scattering profile data 21 as a function of (q).

[0032]

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[0033] In the graph illustrated in Fig. 5, filler scattering profile data 21 is added to the graph illustrated in Fig. 3. The filler scattering profile data 21 is a filler scattering intensity I agg (q) function, integrating the scattering profile data of only the filler aggregates for all 10 samples.

[0034] To generate dispersion profile data 30, the scattering intensity ratio S(q), which is the ratio of scattering intensity between each scattering profile data 20 and filler scattering profile data 21, is calculated for each sample 10. Next, dispersion profile data 30 for each sample 10 is generated as a function of the scattering intensity ratio S(q) of scattering vector q. The scattering intensity ratio S(q) is expressed by the following equation (3).

[0035]

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[0036] Each dispersion profile data 30 illustrated in Fig. 6 is an approximation of a group of points (not shown) plotted at the positions corresponding to the scattering vector q and the scattering intensity ratio S(q) for each sample 10. The solid line, dashed line, one-dot chain line, and two-dot chain line in Fig. 6 represent the dispersion profile data 30 for samples 10 with filler volume fractions of 5 vol%, 10 vol%, 15 vol%, and 20 vol%, respectively.

[0037] In step (S140), the dispersion state of the filler agglomerates in each sample 10 is evaluated based on the respective dispersion profile data 30. The dispersion state of the filler agglomerates being evaluated refers to the inter-aggregate distance and diffusion state between the filler agglomerates present in the sample 10. The scattering intensity ratio S(q) indicates the magnitude of the scattering intensity of only the filler agglomerates contained in the corrected scattering intensity I(q) / φ, and therefore indicates the intra-particle interference effect, such as the size and shape of the filler agglomerates in the sample 10, and the inter-particle interference effect, such as the inter-aggregate distance. In other words, the dispersion profile data 30 represents the inter-aggregate distance and diffusion state of the filler agglomerates in the sample 10. Therefore, the dispersion state of each sample 10 can be grasped based on the respective dispersion profile data 30. For example, in Figure 6 described above, the inter-aggregate distance in sample 10 with a filler volume fraction of 5 vol% is longer than that of the other samples 10, indicating a sparse dispersion state. In this way, the dispersion state of the filler agglomerates in the vulcanized rubber can be accurately grasped based on the generated dispersion profile data 30.

[0038] Specifically, in step (S140), an evaluation index is calculated from the dispersion profile data 30, and the calculated evaluation index is used to quantify and evaluate the dispersion state of the filler aggregates in the sample 10. The evaluation index can be the mode d of the inter-aggregate distance in each sample 10. The mode d of the inter-aggregate distance is based on the peak of each dispersion profile data 30. In more detail, first, the scattering vector q at which the scattering intensity ratio S(q) in each dispersion profile data 30 is maximized is calculated. max Then, each of the identified scattering vectors q max The most frequent value d of the inter-aggregate distance in each sample 10 is calculated based on the above. The most frequent value d of the inter-aggregate distance is 2π / q max The longer the mode d, the more sparsely the distribution, and the shorter the mode d, the more densely the distribution.

[0039] The evaluation index is the average inter-aggregate distance ξ PBG and standard deviation σ can be used. PBGand standard deviation σ are calculated using the following formulas (4) to (7): In the following formulas (4) to (7), the inter-aggregate distance is ξ, the log-normal distribution function of the inter-aggregate distance ξ is P(ξ), the spherical amplitude structure function is θ(q, ξ), and the packing factor (filling rate) is p.

[0040]

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[0041]

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[0042]

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[0043]

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[0044] The average calculated inter-aggregate distance ξ PBG The longer the distribution, the sparser the mean value ξ PBG The shorter the value, the denser the dispersion state. In addition, the larger the calculated standard deviation σ, the greater the variation in the distance between filler aggregates, and the more non-uniform the dispersion state is. The smaller the standard deviation σ, the smaller the variation in the distance between aggregates, and the more uniform the dispersion state is. The evaluation index is the average value ξ of the distance between aggregates. PBG Alternatively, only the standard deviation σ of the inter-aggregate distances may be used. Furthermore, the mode d, mean value ξPBG, and standard deviation σ of the inter-aggregate distances may be used individually as the evaluation index. The evaluation index may be calculated based on the respective dispersion profile data 30.

[0045] As described above, according to this embodiment, by using multiple samples 10 with different filler volume fractions φ, it is possible to utilize the relationship between the reciprocal of the corrected scattering intensity I(q) / φ for each scattering vector q and the filler volume fraction φ. This relationship can then be used to accurately screen the filler scattering profile data 21, which integrates the scattering profile data of only the filler aggregates in all samples 10 from the respective scattering profile data 20. The dispersion profile data 30, which shows the relationship between the scattering intensity ratio S(q) and the scattering vector q obtained using the scattering profile data 20 acquired by measurement and the screened filler scattering profile data 21, represents the inter-aggregate distance and the degree of diffusion of the filler aggregates in each sample 10. Therefore, the dispersion state of the filler aggregates in each sample 10 can be accurately grasped based on the respective dispersion profile data 30, allowing the dispersion state to be evaluated in accordance with the actual situation.

[0046] Furthermore, according to this embodiment, it is sufficient to prepare a plurality of samples 10 that differ substantially only in the filler volume fraction φ, and there is no need to particularly limit the amount of filler blended in the vulcanized rubber used for the samples 10. Therefore, it is possible to evaluate the dispersion state of filler aggregates in various vulcanized rubbers that differ in the amount of filler blended, which greatly contributes to the development and research of rubber products that use vulcanized rubber.

[0047] In the embodiment described above, the scattering profile data 20 uses the corrected scattering intensity I(q) / φ obtained by correcting the scattering intensity I(q) obtained by measurement with the volume fraction φ, but it is also possible to use a value obtained by correcting the scattering intensity I(q) obtained by measurement with the thickness of the sample 10. Specifically, a value obtained by dividing the scattering intensity I(q) by the thickness of the sample 10 is used.

[0048] The present invention is not limited to a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention. [Example]

[0049] Using four types of vulcanized rubber samples (samples 1 to 4) shown in Table 1 below, the average inter-aggregate distance ξ for each sample was used as an evaluation index using the same evaluation method as shown in FIG. 2 above. PBG was calculated. Table 1 shows the compounding data for each sample, with the amount of additives represented as parts by mass relative to 100 parts by mass of the polymer (styrene-butadiene rubber). Samples 1 to 4 were produced under substantially the same manufacturing conditions, such as mixing conditions and vulcanization conditions, with only the volume fraction of silica being varied to 5 vol%, 10 vol%, 15 vol%, and 20 vol%.

[0050] [Table 1]

[0051] In the X-ray scattering device 2, the camera distance was set to 8 m, and the X-ray energy was set to 6.2 keV, and the scattering profile data 20 of each sample 10 was acquired using small-angle X-ray scattering. The range of the scattering vector q in each acquired scattering profile data 20 was 0.01 nm -1 ~0.2nm -1 It was.

[0052] The graph shown in FIG. 7 shows the average inter-aggregate distance ξ of each sample calculated using the same evaluation method as shown in FIG. PBG The black dots in Figure 7 represent the volume fraction φ of each sample and the calculated average inter-aggregate distance ξ PBG The average inter-aggregate distance ξ for each sample increases with the increase in the volume fraction φ of the filler. PBG It can be seen that the length is shorter and the filler aggregates are more densely dispersed.

[0053] The present disclosure includes the following inventions. Invention (1): A method for evaluating the dispersion state of filler aggregates in rubber, comprising: obtaining scattering profile data of a vulcanized rubber containing a filler by measuring the sample with an X-ray scattering method or a neutron scattering method; and using the obtained scattering profile data, a plurality of vulcanized rubbers each having a different volume fraction of the filler are used as samples, and the scattering profile data is acquired for each of the samples; a method for evaluating the dispersion state of filler agglomerates in rubber, the method comprising: processing each of the scattering profile data using a computing device; generating filler scattering profile data extracted from the scattering profile data of filler agglomerates in all of the samples using the relationship between the inverse of the scattering intensity for each scattering vector in each of the scattering profile data and each of the volume fractions; calculating a scattering intensity ratio for each of the samples based on the acquired scattering profile data and the generated filler scattering profile data; generating dispersion profile data showing the relationship between the scattering intensity ratio and the scattering vector; and evaluating the dispersion state of the filler agglomerates in each of the samples based on the generated dispersion profile data. Invention (2): A method for evaluating the dispersion state of filler aggregates in rubber according to invention (1), wherein the scattering profile data uses, as the scattering intensity, a value obtained by correcting the scattering intensity of each of the samples obtained by measurement using the X-ray scattering method or the neutron scattering method with the respective volume fractions or the respective thicknesses of the samples. Invention (3): A method for evaluating the dispersion state of filler agglomerates in rubber according to invention (1) or (2), wherein, in evaluating the dispersion state of the filler agglomerates, the most frequent value of the inter-agglomerate distances between the filler agglomerates in each of the samples is calculated based on the dispersion profile data of each of the samples, and the calculated most frequent value is used as an evaluation index. Invention (4): A method for evaluating the dispersion state of filler agglomerates in rubber according to any one of inventions (1) to (3), wherein the evaluation of the dispersion state of the filler agglomerates involves calculating an average value of the inter-agglomerate distances between the filler agglomerates in each of the samples based on the dispersion profile data of each of the samples, and using the calculated average value as an evaluation index. Invention (5): A method for evaluating the dispersion state of filler agglomerates in rubber according to any one of inventions (1) to (4), wherein the evaluation of the dispersion state of the filler agglomerates involves calculating the standard deviation of the inter-agglomerate distances between the filler agglomerates in each of the samples based on the dispersion profile data of each of the samples, and using the calculated standard deviation as an evaluation index. [Explanation of symbols]

[0054] 1. Rating System 2 X-ray scattering device 3 Computing device 10 samples 20 Scattering profile data 21 Filler scattering profile data 30 Distributed Profile Data q scattering vector I(q) scattering intensity φ volume fraction S(q) Scattering intensity ratio

Claims

1. A method for evaluating a dispersion state of filler aggregates in rubber, comprising the steps of: using a vulcanized rubber containing a filler as a sample, obtaining scattering profile data of the sample by measurement using an X-ray scattering method or a neutron scattering method; and using the obtained scattering profile data, A plurality of vulcanized rubbers having different volume fractions of the filler are used as samples, and the scattering profile data is acquired for each of the samples. A method for evaluating the dispersion state of filler agglomerates in rubber, comprising: processing each of the scattering profile data by a computing device; utilizing the relationship between the inverse of the scattering intensity for each scattering vector in each of the scattering profile data and each of the volume fractions, generating filler scattering profile data extracted from the scattering profile data of the filler agglomerates in all of the samples; calculating a scattering intensity ratio for each of the samples based on the acquired scattering profile data and the filler scattering profile data; generating dispersion profile data showing the relationship between the scattering intensity ratio and the scattering vector; and evaluating the dispersion state of the filler agglomerates in each of the samples based on the generated dispersion profile data.

2. 2. The method for evaluating the dispersion state of filler agglomerates in rubber according to claim 1, wherein the scattering profile data uses, as the scattering intensity, a value obtained by correcting the scattering intensity of each of the samples obtained by measurement using the X-ray scattering method or the neutron scattering method with the respective volume fractions or the respective thicknesses of the samples.

3. 3. The method for evaluating the dispersion state of filler agglomerates in rubber according to claim 1 or 2, wherein in the evaluation of the dispersion state of the filler agglomerates, a mode of inter-agglomerate distances between the filler agglomerates in each of the samples is calculated based on each of the dispersion profile data, and the calculated mode is used as an evaluation index.

4. 3. The method for evaluating the dispersion state of filler agglomerates in rubber according to claim 1 or 2, wherein in the evaluation of the dispersion state of the filler agglomerates, an average value of inter-agglomerate distances between the filler agglomerates in each of the samples is calculated based on each of the dispersion profile data, and the calculated average value is used as an evaluation index.

5. 3. The method for evaluating the dispersion state of filler agglomerates in rubber according to claim 1 or 2, wherein in the evaluation of the dispersion state of the filler agglomerates, a standard deviation of inter-agglomerate distances between the filler agglomerates in each of the samples is calculated based on each of the dispersion profile data, and the calculated standard deviation is used as an evaluation index.

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