JPS5971367A - High-structure carbon black - Google Patents

Abstract

PURPOSE:To provide a carbon black having a specific surface area determined by nitrogen adsorption, an absorptivity of dibutyl phthalate and a structure intensity index falling within specific ranges, and high structure, and capable of giving a rubber composition having excellent quality. CONSTITUTION:A carbon black having a specific area determined by nitrogen adsorption (N2SA) of 60-70m<2>/g, an absorptivity of dibutyl phthalate (Ao) of 165-210ml/100g, and a structure intensity index (K) of 0.2-0.35. Preferably, the carbon black has, in addition to the above three properties, a ratio of the iodine adsorption [IA (mg/g)] to N2SA (IA/N2SA) of 0.7-0.9, and a difference between the calculated value and the measured value of the DBP adsorptivity (24M4 DBP adsorptivity) of -6-+6 after compressing the carbon black in a cylinder with a piston four times under a pressure of 1,687kg/cm<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high structure cardin black. More specifically, the present invention relates to a car black that has an extremely high struture and is characterized in that the mechanical strength of the struture against changes in applied external force is increased to a certain value or more.

It is well known that the three basic properties of carbon black are the specific surface area (or particle size), structure, and surface chemical activity, which are important factors in performance. Among these structures, there are permanent struc- tures (also called aggregates) that are formed by the fusion of particles during the production of carton blacks, and aggregators that are formed by physical forces such as van Yu der Waals-London forces. It is well known that cardin black stractures exist as the sum of both temporary structures that are combined and formed.

As the Luer method for evaluating the stracture of cardin black, there is a method of filling the voids of carbon black with a sieve, and DBP absorption (hereinafter referred to as Ao) is usually used.

This is to calculate the absorption amount me of dibutyl phthalate (DBP) per 100 g of carbon black, and the value of Ao is considered to be a value representing the size of the carbon black stractures, which is the permanent stracture and the temporary structure 2. .

As a method to evaluate mainly permanent stractures in cardin black stractures, carbon black placed in a cylinder was heated to 1687 k using a piston.
DB after compressing 4 times with G7 Award (24000psi)
There is a method for measuring P absorption (hereinafter referred to as 24M4DBP absorption 1, A4).

Somewhat more direct methods for evaluating the mechanical strength of cardin black struc- tures include grinding the carbon black in a zero mill or compressing the carbon black in a cylinder with varying pressures. The method of measuring the amount of DBP absorbed after immersion is only performed in a laboratory, and all methods lack uniformity in terms of equipment and operation. Currently, as an index of cardin black stracture strength, in many cases the "ratio" or 6 difference between Ao and ^ is used, or the stracture strength is expressed by a combination of two numbers. This is normally done, but in any case there is no change in the fact that display is attempted using two measurement points, Ao and A4. As a result, the influence of the mechanical strength of the cardin black struc- tures on various properties exhibited by carbon black compositions was
It is difficult to explain based on the two numerical values of o and A4, and we have obtained the knowledge that the mode of the collapse process of the stracture in response to a wide range of changes in external mechanical force is important. In other words, as an indicator of stracture strength, it must indicate the difficulty of stracture collapse in response to changes in external forces over a wide range, and it is reasonable to infer stracture strength from the size of stracture at just two points. For example, in the formulation example described below, the same level of Ao,
Even with A4, the extrusion characteristics such as die swell are 2
It shows an extremely high correlation with the DBP absorption of carbon black after being compressed once at 4000 psi, and the dynamic performance such as impact resilience and heat generation characteristics is the same as the DB after being compressed 2 to 3 times.
They found that the amount of P absorbed and fracture resistance properties such as tensile and abrasion resistance are highly correlated with the amount of DBP absorbed after four or more compressions, depending on the degree of severity.

This fact indicates that it is necessary to study the effect of cardin black struttle strength on various properties of carzen black compounded compositions over a wide range of external forces, and to investigate the difficulty of struture collapse due to changes in external force. Therefore, the validity of using it as an index of struture strength will be understood.

The present inventors have devised a method for converting and displaying the above-mentioned difficulty of collapse of cardin black stractures into a stracture strength index (k) using a carbon black with an extremely high structural level. The inventors have completed the present invention by discovering that carbon black whose index Qc) is kept within an appropriate range imparts extremely good performance to rubber compositions.

In the present invention, the strength index (k) of the carbon black structure was determined by using the same equipment as in the 24M4 DBP absorption measurement method, performing the same operation, and varying the number of compressions (1) of the carbon black structure. , the DBP absorption amount at that time was measured and A1 was obtained, 1=20 (compressed 20 times)
It is obtained by statistically approximating the following equation, assuming that the DBP absorption amount at the time is A.

The coefficient k in Equation (1) is a structure strength index indicating the difficulty of collapse of the Karpon Prack structure,
The small value of k means that when an extremely large external force is applied, for example, when 20 compression processes are applied at 24,000 ps1, the total amount of stractures is destroyed, but when a relatively small external force is applied, for example, several times, This means that the ratio of straftures that are destroyed when compression treatment is applied several times is relatively small, which means that the stractures have high mechanical strength against changes in external force. The cardin black according to the present invention is limited to cardin black having a k value of 0.2 to 0.35.

Ao is 165-210m1/100.1? , N, SA of 60 to 70 ytt'/Fl is produced in a cylindrical apparatus in which the combustion zone and the reaction zone have approximately the same inner diameter, such as an ordinary soft grade carzen black manufacturing apparatus. When manufactured without adding special control conditions, the value of k exceeds 0.4, and usually shows a value of about 0.6.

If we compare the results using other characteristic values, we can see the following. That is, the calculation 24M4 obtained by the following equation (2)
DBP absorption 11(Ac)ac = -o,s 9+0.
229X (N, SA) + 0.918X (AD) −
2,045X 10″″”
Normal cardin black with Ao of 140 m1/1011 or less at ~70 m/I/ is in the range of -8 to 8,
If it is limited to commercially available products, it is in the range of -6 to 6.

However, in the case of the above-mentioned cardin black, which has a high value of stracture strength index, the mechanical strength of the stractures is low, even if the value of ΔA is in the range of −6 to 6 compared to normal carbon silk. Although it is recognized that for some reason it exhibits properties that have completely different useful uses, such as good extrusion properties and excellent dispersibility, the cardin black of the present invention does not have good properties such as those possessed by the cardin black, i.e., It is not possible to achieve consistency between dynamic properties and fracture resistance, which will be described later.

The cardin black of the present invention falls within the range of the related values of conventional commercially available cardin blacks if we only pay attention to the relationship regarding the above-mentioned ΔA value. However, despite this, it exhibits various good properties due to its extremely high struture strength.

It can be said that it is in the open position. This is because when comparing FEF and HAF, FEF generally has superior dynamic performance such as impact resilience and heat generation, and fatigue fracture performance such as flexural crack growth, while HAF has superior tensile strength, tear strength, and resistance. To provide a composition containing cardin black which has excellent wear resistance and other fracture resistance.

A composition obtained by blending cardin black according to the present invention so as to have the same hardness as a composition containing FEF and HAF has dynamic properties comparable to those of a composition containing FEF, and has fracture resistance. The composition significantly improves that of FEF, and exhibits fracture resistance comparable to or better than that of HAF-containing compositions, depending on the components.

In cardin black according to the present invention, 60 to 70
In addition to N and SA of yl/9, A is an essential component.
It is required that o is 165 to 210 ml/1001/, and the stracture strength index (k) is within the range of 02 to 0.35.

Generally speaking, the dynamic properties of a composition containing carbon black are better as the specific surface area of cardin black is smaller.
In the cardin black of the present invention, N and SA are so
If it is less than 70 m''/m, the tear strength and abrasion resistance of the rubber composition blended with it will be close to that of FEF, and no improvement effect will be observed, which is undesirable.
I! If it exceeds r″EF, the fracture strength improves, but the dynamic properties and fatigue fracture resistance are significantly lower than those of r″EF, so it is limited to 60 to 70 m″/11.

Furthermore, in a compounding system that has the same hardness as FEF and HAF compounded rubber compositions, the cardin black of the present invention allows for a significant reduction in the amount of dispersion. Ao is 165m1710
If it is less than 0&, the reduction effect of the carbon black-containing mackerel is diminished. Furthermore, it is extremely difficult to produce cardin black with a structure in which the AO exceeds 210 mV and 100 g at the current technological level as long as the oil furnace method is used. The upper limit of Ao in the present invention is set to 210.
limited to me/10011.

In a rubber composition compounded with cardin black, which has a low struture strength such as a struture strength index k of more than 0.35, properties in a relatively small range of external stress, such as impact resilience and heat generation properties, are improved. Dynamic properties and fatigue fracture properties such as flexural crack growth are significantly reduced.

This is because even a relatively small external deformation causes the straftures of cardin black present in the rubber composition to collapse due to the low straftture strength, and if this external deformation is repeated, the strafttures will collapse.・It is presumed that due to repeated recombination, the so-called hysteresis loss becomes excessive in the process, which reduces the stress concentration relaxation effect, causing internal heat generation, permanent distortion, etc., and causing performance deterioration. be done. Conversely, in the case of carbon black with a very small k value of less than 0.2, it can be said that the carbon black has an extremely high relative stracture strength, but it cannot be applied with a relatively small external mechanical force. When compared with cardin black, which has the same strafture (e.g. 24M4DBP absorption amount) and has a larger value of k, the strafture is retained when a very large external force is applied. decreases dramatically. For these reasons, performance such as abrasion resistance and tensile strength under extremely harsh conditions deteriorates significantly when k is less than 0.2. 2 is the lower limit.

Dynamic properties such as impact resilience and heat generation properties, and fatigue fracture properties such as flexural crack growth properties are determined by external M applied repeatedly to the cardin black compounded rubber composition; regarding deformation, relaxation and averaging of internal stress concentration It is thought that a mechanism that is improved and improved by reducing the amount of hysteresis and a mechanism that is improved and improved by reducing so-called hysteresis loss are combined. In a composition using cardin black, which has a large proportion of strafts with relatively low mechanical strength, when external deformation is applied to the composition, some of the strafts collapse, resulting in local internal stress. It alleviates and averages out the concentration, contributing in part to improving dynamic properties and fatigue fracture resistance. However, at the same time, in the process of repeated external deformation, the carzen black structure in the composition repeatedly collapses and recombines, increasing so-called hysteresis loss, and the effect of improving dynamic properties and fatigue fracture resistance is reduced. This results in restrictions. Therefore, in order to achieve sufficient performance improvements and improvements in the car of the present invention, it is important to increase the strength of the carmenzolac structure to a certain value or higher against changes in external forces over a wide range.

In addition to the three requirements mentioned above, the cardin black of the present invention has a nitrogen adsorption specific surface area (Nx S A: m”/1
1) and iodine adsorption m (I a :rny/p), preferably cardin black in which the ratio IA/N, SA is kept within the range of 0.7 to 0.9, and furthermore, #1' calculation z4M4DBpm Convergence (AcmA'/100
, 9) and the measured 24M4DBPg&yield (A, me/lo
ng) and (D difference, ΔA, is limited to the range of -6 to 6, and in addition to or in addition to the three requirements above, I A/N2S
More preferred is carbon black which is maintained in addition to the favorable requirements of the A ratio.

The values shown by the I A/N and S A ratios are thought to be related to the chemical activity of the cardan ivy surface towards many types of rubber molecules, and if this value exceeds 0.9, the tensile strength and repulsion will decrease. This is undesirable because it causes a decrease in performance such as elasticity and an increase in heat generation and flexural crack growth. , if it is less than 0.7, a large amount of undecomposed substances of the raw materials for producing Cardin Black or by-products of by-reactions will adhere to the surface of Cardin Black, and foaming will occur during the vulcanization process of the rubber composition compounded with Cardin Black. This is undesirable because it not only causes problems such as excessive shortening of the scorch time and contamination of the vulcanized composition with oily substances, but also a decrease in tear strength as seen in the examples below.

As explained above, the ΔΔ value is a value that indicates the properties of the strafts maintained when a relatively small external mechanical force is applied to the cardin black according to the present invention. Although the cardin black of the present invention is significantly different from the commercially available high-structure cardin black in terms of stracture level, it is preferable that the relationships between Ao, SA and ΔA are in the same extended range. By maintaining these properties, various good properties can be exhibited.

Carbon black according to the invention, i.e. 60-7o
m'/l NJA s 165-210 ml/l
Cardin black with a characteristic range of DBP absorption of 00S, and a stracture strength index of 0.2 to 0.
．． By blending carbon black in a specific range of 35 into the rubber, the rubber composition has fracture resistance properties such as tensile strength, tear strength, and abrasion resistance that are equal to or higher than HAF, but it also has repulsion equivalent to FEF. It is possible to provide an extremely useful rubber composition that has dynamic properties such as elasticity and heat generation properties, and is also excellent in fatigue fracture performance such as flexural crack growth.

That is, by using the cardin black of the present invention having the above-mentioned properties, the trade-off that increasing the reinforcing properties (fracture resistance) of rubber does not result in both dynamic properties and fatigue fracture performance can be resolved.

In addition to the above-mentioned conditions, cardin black that provides such rubber properties has I A/N and SA of 0.7 to 0.
9. Carbon black having a characteristic of ΔA of −6 to 6 is more preferable. Therefore, the cardin black according to the present invention is suitable as a reinforcing filler for various industrial rubber members or rubber compositions for tires, which can exhibit the above-mentioned advantages.

The cardin black according to the present invention is manufactured using an oil furnace type manufacturing apparatus equipped with a so-called venturi portion. As such a manufacturing apparatus, the apparatus described in JP-A-57-108163 (patent applicant: Asahi Kazen Co., Ltd.) can be used as is.

That is, a horizontally placed cylindrical combustion gas filling chamber, a cylindrical cardin black generation reaction chamber coaxially connected to the filling chamber and having a smaller diameter than the filling chamber, and a central axis of the filling chamber. a raw material introduction device for introducing a hydrocarbon raw material held in the reactor, a reaction continuation and rapid cooling chamber coaxially connected to the end of the reaction chamber, and a flue connected to the rear end of the rapid cooling chamber. (a) at least one combustion gas inlet having a central axis located in a tangential direction of the first half of the combustion gas filling chamber; established,
A cylindrical combustion gas generation chamber is connected to the inlet, and a fuel combustion device is inserted and held at the central axis position of the combustion gas generation chamber; (b) between the combustion gas filling chamber and the reaction chamber; A part of the venturi is provided, and a raw material introducing device is installed in the direction of the center axis of the upstream end wall of the filling chamber so that it can be freely inserted and withdrawn, a heat-insulating cooling jacket is provided on the outer wall of the raw material introducing device, and the material introducing device is Place the tip at a position V downstream of a perpendicular line drawn from the outer periphery of the rearmost end of the combustion gas inlet to the central axis and upstream of the venturi partial inlet, and (c) attach the raw material introduction device. At least two gas injection nozzles are provided on the outer circumferential wall of the insertion port so as to flow across the gas fluidized bed in the combustion gas filling chamber, symmetrically and equiangularly on the circumference, and (b) cooling water pressure. A carbon black production apparatus is used in which a plurality of injection sprayers are installed on the wall of the reaction continuation/rapid cooling chamber, and a plurality of water spray parts of the sprayers are installed in such a manner that they can be freely inserted into and withdrawn from the chamber.

In addition, this manufacturing equipment (hereinafter the reference numerals are from the above-mentioned Japanese Unexamined Patent Publication No. 57-10
In the reaction continuation/rapid cooling chamber (according to the drawings in Publication No. 8163), there are nine cooling water injection @ foggers (according to the drawings in Publication No.
g*hwl) can be installed. From the reaction chamber side, the portions where cooling water injection sprayers a and b are installed have the same diameter as the reaction chamber, and C and drt
J! The atomizer attachment position is enlarged (expanded space) than the reaction chamber diameter and has a truncated conical shape, and e and fl!
J! The part where the i device is attached is reduced in size (reduced space) than the diameter of the reaction chamber, and the part where the g-i sprayer is attached is a space slightly larger than the diameter of the reaction chamber, which is connected to the flue.

Further, as the raw material oil for the carbon black according to the present invention, it is desirable to use a coal-based or petroleum-based raw material oil with a high BMCI value. 1 In this production equipment, the main quality performance of carbon black is mainly formed in the zone from the throat of the venturi to the 11th outlet, but other physical and chemical properties are determined by the thermal stress from the feedstock oil spraying position to the rapid cooling position. It is formed by the space velocity of the turbidity reaction zone.

In particular, when the expansion/contraction space of the reaction continuation/rapid cooling chamber described above is used as a reaction continuation zone, that is, when the cooling water injection sprayer is operated at a position downstream of the contraction space, This contributes to the development and strengthening of carbon black stractures during the course of the reaction, and is extremely suitable for the production of carbon black according to the present invention.

EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Production Example Carbon black according to the present invention and carbon black for performance comparison were produced using a production apparatus equipped with a part of a venturi having the structure described in JP-A-57-108163. The dimensions of each component of this manufacturing equipment are shown in Table 1, the properties of the raw material oil used are summarized in Table 1, and the operating conditions of the manufacturing equipment are summarized in Table 1.

Table-I Combustion gas filling chamber Diameter: 850 mm φ Length: 400 wm Combustion gas inlet (2 symmetrically located) Inner diameter: 200 Node φ Center position: 10C from the inner circumference of the combustion gas filling chamber
・Inner diameter of gas (air) injection nozzle...1001111φ 4 center positions・
...70 mm from the inner periphery of the combustion gas filling chamber Gravity Venturi population length...1 ooma (cone angle; 127 degrees)
Throat diameter...300wRφS12-14...150m Outlet length...170t
+* (cone angle: 30 degrees) Reaction chamber diameter: 400 bleached φ Length up to a sprayer: 350 m Reaction continuation and rapid cooling chamber expansion space (CXD fountain pot section ) Long diameter...6001ffl+lφShort diameter...
...300 Kasumiφ Length...5ooTb Reduction space part (e-f sprayer part) Diameter...300111111φ Length...
...500a Distance from a sprayer to 1 sprayer...2150■
A pressure spray type raw material introduction device equipped with a water cooling jacket for thermal insulation cooling was inserted into the central axis of the combustion gas filling chamber.

An air atomization type fuel (natural gas) combustion device was installed in the combustion gas generation chamber.

Table 1 (Coal-based cardin black oil) Some of the properties of cardin black according to the present invention have already been described, but they are measured as follows: ON! SA: A
DBP absorption amount (muo): DBP of cardin black measured in accordance with JIS-6221. It represents the yield and evaluates the stracture of cardin black.

It is usually expressed as absorption amount per 100J, m/100jl.

24M4DBP absorption capacity (A4): ASTM D-a
493, the amount of DBP absorbed is measured after the sample cardin black is compressed and decompressed four times in a cylinder at a pressure of 1687 kfAwI/1 (24,000 psl).

Iodine adsorption ff1(ra): JIS-K 6221
-197! The my number of iodine is measured according to S "Cargin black test method for rubber".

The physicochemical properties of the produced cardin black are summarized in Table-■.

The cardin blacks of Run A1 to 7 in Table-■ satisfy all of the main requirements, & 6 g? I of the requirement that only
A/N, S A is not satisfied. Run A＼ 8.9 comparative cardin black has desirable requirements I A
/N, SA ratio is satisfied, but it is outside the required range of k.

In addition, for comparison, Table - ■ shows Asahi Kazen Co., Ltd. Choko product name, *5o (pEr grade Kakar Black s A S
50 equivalent product) and product name #
70 (HAF class Karkaan Black.

ASTM, N-330 equivalent) is also listed.

In order to evaluate the performance of cardin black shown in Table 1, rubber compositions were prepared with the blending ratios shown in Table 2 and subjected to various tests.

Table 2 shows the compounding conditions when the amount of test cargin black was changed so that the hardness was equivalent to that of a compound of 50 parts by weight of FEF carmen black based on 100 parts of Go A.

Table -■ Natural rubber (R8SI) 100 parts Carcar black Variant, magnetically variable 1) Aromatic oil (softener) 10 Stearic acid (dispersed vulcanization aid) 3 Zinc white (vulcanization aid)
5 Sulfur (vulcanizing agent) 2.5 Vulcanization accelerator MBTS 0.6 Anti-aging agent
PP Dal 11) The same hardness as the FEF black 50 parts by weight formulation.

2) 2.2'-dipenzothiazyl disulfide (2,
2'-dibsnzothiazyl disulfi
de)
Phenyl diamine (N-1sopropyl-N'-phenyl-
(P-phenylenedlamine) The performance of each rubber compound was measured and evaluated using the rubber property test conditions of GG.

Rubber property test conditions ■ Vulcanization conditions of compound: 145C', 30 minutes ■ Exothermic test ASTM D, 623-78 Standard Te5t Methods for
RubberProperty-Heat Gene
ration and FlexingFatigue
in Compression: Method A
Measured according to.

■Abrasion test Using a Lanzen abrasion tester, measurements were made at a slip ratio of 60%, and the abrasion resistance was determined using the following formula.

Wear resistance index = (S/T)X 100 (%) SnIR
B. Volume loss at 60% slip of test piece For the rubber properties in Table -
A summary is shown in ■.

(Left space below) Table -■ shows the rubber properties corresponding to Table -■.

(a) Tensile strength: Although Run Al~6 has a smaller specific surface area than HAF, it has been shown to have reinforcing properties equal to or greater than HAF.

RunA7 does not satisfy the desired requirements for IAlN, Sp, so it is slightly inferior in this characteristic, but FE
Shows better performance than F.

In Run A3, the value of k does not satisfy the main requirements, so the improvement effect is inferior.

(b) Abrasion resistance: R, un A 1 to 7 are F
It exhibits much better wear resistance than EF, and particularly in Run A2.3.517, it shows wear resistance equal to or better than HAF.

Run A3 has a much lower degree of improvement since the value of k does not satisfy the main requirement.

(c) Tear strength: It is recognized that Run A 1 to 7 and Comparative Examples () have a significant improvement effect compared to the tear strength of FEF.

Run A3 is FEF because the value of k does not satisfy the main requirement.
The performance is the same or lower than that.

(→ Dynamic properties: Runs A1 to 7 have the same dynamic properties of rebound resilience, heat generation, and compressive strain as those of FEF, but
Among them, RunA7 does not satisfy the desirable requirements for IA/N and SA, so it is slightly inferior compared to the others.

In Run A9, the value of k does not satisfy the main requirements, so the performance is lower than that of FEF in terms of impact resilience, heat generation, and compressive strain.

(e) Flexural crack growth: Run A 1 to 7 are FEF
RunA shows the same fatigue fracture resistance as RunA.
7 does not satisfy the desired requirements for IAlN and SA, so its performance is inferior compared to the others.

Run7i9 does not satisfy the value of k or the main requirements, so FEF
Overall, it is possible to maintain the same dynamic properties as FEF, including impact resilience, heat generation, and compressive strain, and to improve tensile strength, abrasion resistance, and tear strength. In order to significantly improve the two reinforcement performances, fracture resistance shown by flexural crack growth and fatigue fracture resistance shown by flexural crack growth, compared to that of FEF, it is necessary to It is understood that the value of must also be satisfied.

In other words, when looking at RunAl and 4, the tear strength and abrasion resistance are close to FEF, and there is a risk that the improvement effect will decrease, so N and SA need to be 60 m/11 or more. It is said that However, Run A2
As seen at t5, when N25A reaches 70 nj/9, there is a high possibility that the dynamic properties of impact resilience, heat generation and compressive strain, and fatigue fracture resistance of flexural cracks will be lower than that of FEF. 70 ml& is considered the upper limit for N,SA.

In Comparative Example 8, the value of k, which is the main criterion, is 0.
．． Since it is less than 2, the fracture resistance shown by tensile strength, tear strength and abrasion resistance is significantly inferior to the examples,
Comparative Example 9 has significantly higher fracture resistance, but k
Since the value exceeds 0.35, a significant decrease in impact resilience, dynamic properties indicated by heat generation, and fatigue fracture resistance properties indicated by flexural cracking is observed.

Claims (1)

[Claims] 1. The nitrogen adsorption specific surface area (N, SA) is 60 to 70 m/g, the dibutyl phthalate (DBP) absorption amount (Ao) is 165 to 21 OTnl/100 g, and the stracture strength index (k) is High structure cardin black within the range of 0.2 to 0.35. 2. The ratio IA/N, SA of iodine adsorption i [A (m9/g)] to nitrogen adsorption specific surface area (N, SA) is 0.7 to 0.
．． 9. The high structure cardin black according to claim 1 falling within the scope of claim 9. 3. Calculated 24M4DB P absorption amount (
Ac ml/100g); Ac=-0,59+〇,22
9 X (N, SA) + 0.918X (AO) -2,0
24M4D measured as 45X10-”X(AO)”
Difference from BP absorption (A4ml/loog) (Ac-A,
) is within the range of -6 to 6. The high structure cardin black according to claims 1 to 2.