JPS62250073A - Carbon black having modified surface and production thereof - Google Patents

Abstract

PURPOSE:To obtain the titled carbon black useful for rubber reinforcing and as a filler, having improved dispersibility and processing properties, by blending carbon black having large surface area with a solution of a p-phenylenediamine compound, etc., and drying at a specific temperature. CONSTITUTION:(A) 100pts.wt. carbon black having >=130m<2>/g specific surface area by nitrogen adsorption is blended with (B) an organic solvent (e.g. toluene, etc.) or water dispersion containing 0.5-50pts.wt. one or more compounds [e.g. N-(1-methylhepthyl)-N'-phenyl-p-phenylenediamine, etc.] shown by formula I (R is isopropyl, 1,3-dimethylbutyl, 1-methylheptyl, phenyl, group shown by formula II or p-toluenesulfonyl), the solvent or water is removed and dried at 150-200 deg.C to give the aimed compound wherein the component B is added to the surface of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface-modified car 2 plastic and a method for producing the same, and more specifically, an amine anti-aging agent is added to casen black having a high surface area to improve its dispersibility in rubber and the process for producing the same. The present invention relates to a surface-modified carcin black that can improve processability and a method for producing the same.

Carne black is used in many rubber products as a reinforcing filler for various rubbers.

It is well known that the reinforcing properties of carzen black for rubber are related to the size of the primary particles constituting carzen black and the size of the higher-order structure (hereinafter referred to as struture) that carzen black has. In other words, as a general tendency, the smaller the primary particle diameter, that is, the larger the surface area per car plug weight, and the larger the struttle shown by the oil-absorbing leaf of the resin, the greater the reinforcing property to rubber. It can be said that it will be.

However, in order for the inherent reinforcing properties of Riki-Zen Black to be exhibited, it is necessary that the car 2 plugs be uniformly dispersed in the rubber matrix. That is, in the process of kneading cardan black and rubber, uniform dispersion of cardan black in the rubber phase is a necessary condition for maintaining the body part of the rubber product.

Generally speaking, the dispersibility of carbon black in rubber increases as the surface area becomes smaller and as the stracture becomes larger.
Cursen black of 20 shi or less rarely causes poor dispersion in practice.

However, N18 people are 130 tr? In Carne black exceeding /f, the dispersibility into rubber decreases markedly as the N28A content increases. For this reason, the reinforcing properties represented by tensile strength and abrasion resistance showed only a slight improvement despite the increase in N, 8A, and when N, SA was 16
If the increase exceeds 0 m2/g, the reinforcing properties may be reduced.

This increases the surface area of Kazen Black and increases the cohesive force of Kazen Black, and at the same time, a strong gel chest is formed around the undispersed aggregates of Kazen Black during the kneading process with rubber. This is thought to be because this inhibits the dispersion of casen black into the rubber. It is understood that when carzene black exists in an undispersed state in the rubber, the substantial surface area of carzen black, which should originally contribute to reinforcement, decreases, and this is the cause of the decrease in reinforcing properties.

Attempts were made to improve the dispersibility in rubber by surface modification of Kazen black, for example,
43 Publication, Special Publication No. 5B-24462, Special Publication No. 4
No. 3-30417 and U.S. Patent No. 3,282,719, etc., both of them add oily substances or polymeric substances to cargin black to reduce the cohesive force between car two plugs, thereby increasing the amount of carbon in the rubber. The aim is to improve the dispersibility of

However, in such conventional technology, N, 8A is 130d
The current situation is that when using Carzen Black with a ratio of /9 or higher, there is almost no effect on improving dispersion, or even if there is an effect, no significant difference is observed. Furthermore, with the above-mentioned conventional techniques, it has been extremely difficult to solve the problem of difficulty in processing unvulcanized rubber blended with high surface area carbon black.

The present inventors have developed a surface-modified carbon black that can significantly improve the difficulty of dispersion and processability during rubber compounding, and a method for producing the same, for carbon black having N and SA of 130 d/f or more. The heading completes the invention.

That is, the present invention provides a compound represented by the general formula 〇)-NH diagram)+-u, in which -R is ? 1゜(I) -OH (imp b pill)
0.5 to 5.0 parts by weight of at least one of the following compounds is added to 100 parts by weight of Kazenglac. The present invention is based on the discovery that, by this, it is possible to obtain carzen black with improved dispersibility in rubber and processability of compounded unvulcanized rubber.

All of the above chemical substance groups are called p-phenyl/diamine anti-aging agents (hereinafter referred to as amine anti-aging agents), and are originally added to rubber compositions to prevent rubber from aging due to ozone. It is blended. It is known that these amine anti-aging agents have the ability to prevent ozone aging of rubber and also have the ability to inhibit gel formation in rubber.

During the kneading process of carbon black and rubber, a gel-like rubber layer called carmen gel is formed on the surface of the carbon black. is thought to play an important role in the dispersibility of

However, it was recognized that simply adding an amine anti-aging agent to rubber has the ability to suppress the formation of cargin gel, but carbon black with a high surface area of 130 d/f or more of N and 8A Its effect is small;
Therefore, no significant difference was observed in the dispersibility of carbon black and the processability of rubber.

However, by adding at least one of the above amine-based anti-aging agents to the surface of Cargin Black in advance, the generation of Carmen gel formed on the surface can be effectively suppressed even if the carbon black has a high surface area. I found out what I can do. By suppressing the generation of carbon gel, it has become possible to disperse even carbon black with a high surface area, which has a large ability to form carbon gel and has a large interparticle cohesive force, in rubber.

In addition, when applying high surface area carn black to rubber,
In addition to the above-mentioned dispersibility, the difficulty of processing the composition poses a problem, resulting in a drawback of reduced workability. This difficulty in processing is thought to be due to the formation of carmen gel and the disordered recombination of active sites at the cut ends of rubber molecules during kneading. In the present invention, the amine-based antiaging agent added to carbon black suppresses the generation of carcin gel, and also prevents the formation of macromolecules due to recombination of molecular chains by capturing the active sites, and as a result, It is thought that this is because the viscosity of the carbon black-containing unvulcanized rubber composition was reduced, and both dispersibility and processability were improved at the same time.

Furthermore, it has been found that by heat-treating Kazen Black to which an amine-based anti-aging agent has been added, preferably at a temperature of 105°C to 200°C, a greater effect on dispersibility and processability can be exhibited. .

All of these amine-based anti-aging agents added to the surface of the carton black are sparingly soluble or insoluble in water, but are soluble in hydrocarbon-based organic solvents such as the alcohol yatoluene.

These chemicals can be added to the surface of Carzen Black by dissolving them in alcohol or organic solvents and then mixing them with Carzen Black, colloidally dispersing them in water and then mixing them with Carzen Black, or by dissolving them in alcohol or organic solvents and then mixing them with Carzen Black. There is a method of mixing Kasen black with a dispersion liquid which is dissolved in a solvent (alcohol) and then diluted with water to precipitate in a colloidal form. Either method can be applied in the present invention. Furthermore, the dispersion efficiency of the dispersed phase can be increased by using various dispersants (surfactants) or mechanical dispersion (homogenizer, ultrasonic dispersion device, etc.).

However, industrially, in the production process of Carzen Black, water in which at least 1 s of the amine-based anti-aging agent is colloidally dispersed is used as a liquid for granulating Carzen Black, and Carzen Black is thereby wet-processed. More preferably, it is prepared by granulating and then removing moisture or solvent in a drying step. For example, Patent No. 99
No. 3698 [Special Publication No. 54-20478, Applicant: Asahi Karin
Using a pin-type granulator that can be controlled at temperatures below °C, a certain amount of powdered carzen black is continuously injected from one end of the granulator, and a colloidal black containing at least one of the amine-based anti-aging agents is prepared. An aqueous solution or an organic solvent solution in which the above-mentioned substance has been dissolved is used as a granulating liquid as it is, or mixed with a granulating liquid prepared elsewhere, and the above-mentioned substance is 0% per 100 parts by weight of the above-mentioned Kazenblack. .5-5.0
Adjust and add parts by weight. The granulated water containing cardin black and an amine-based anti-aging agent is granulated through the transfer of a pin screw in the granulating device, and the above substances are added to the surface of the cardin black from the other end of the granulating device. Zenblack is ejected.

The Carzen Black wet peanuts thus obtained are introduced into a solvent recovery dryer including a hot air flow dryer and a vacuum dryer, where they are dehydrated, desolventized, and dried. At the same time, the Kazen black to which the above-mentioned substance has been added is heated.

The amine anti-aging agent added to Carzen Black is added in an amount of 0.5 to 5.0 parts by weight per 100 parts by weight of Carzen Black, but if it is less than 0.5 part by weight, it will not be added to the rubber. Almost no effect of improving dispersibility or improving rubber processability was observed. On the other hand, when it exceeds 5.0 parts by weight, an improvement effect on processability is recognized, but when the amount exceeds 30 parts by weight,
This is not preferable because the zero coefficient modulus and wear resistance (especially when the degree of severity is high) decreases.

In addition, the drying temperature of the force-Zengrak wet 1 knot is 2.
It is necessary to maintain the drying temperature at 00°C or lower1), and the lower limit of the drying temperature is 105°C or higher. If the temperature exceeds 200°C, the amine anti-aging agent added to the surface of Curzen Black may evaporate or thermally decompose, and if the temperature falls below 105°C, the removal rate of water or solvent will decrease, and the present invention This is undesirable because the objective of improving the dispersibility in rubber and the processability of rubber decreases. This is presumably because, in this temperature range, the formation of a bond between the amine anti-aging agent and the surface of casen black, which does not easily separate during kneading with rubber, is promoted.

Addition in the present invention means that the amine anti-aging agent is physically adsorbed and/or chemically bonded to the surface of Riki-Zen Black.

The above-mentioned Kazenburatsu rubber obtained by the present invention has good dispersibility in rubber and processability of unvulcanized rubber, its N, SA
Is it 13 o tr? /f or more can still be significantly improved.

Next, examples will be shown to demonstrate the present invention in more detail.

Production example Collecting Cargin black produced in the furnace,
A certain amount of powdered Karsen Black was transferred to a bottle-shaped granulator (circle diameter 40 crn, rotating shaft 29.6 side, bottle diameter 1 cIn, number of rotations 47 Or, p, m-1, internal temperature approximately 100°C).
Continuously introduced into. A colloidal dispersion in which an amine degree anti-aging agent is dispersed is prepared as follows:
A predetermined amount of water was added from the middle of the granulation water introduction conduit so as to be a predetermined amount based on parts by weight, and granulation was carried out so that the particle diameter of Karsen Black wet pellets was 0.3 to 1.0 wm.

Ail Jika gold compound Lloyd dispersion is made by first making a 50 wt% alcohol solution, and then adding a nonionic surfactant (
For example, it can be obtained by pouring into water containing 0.25% of Noniolai (trade name) 8-400 (manufactured by Kyoeisha Yushi Kagaku Kogyo @) and operating a homogenizer for about 10 minutes to colloidally disperse it.

The wet Karsen black pellets obtained by the above operation are introduced into a hot air flow dryer, and the temperature of the hot air is controlled so that the temperature of the dry Karsen black discharged from the drying cypress is a predetermined temperature, and the drying and heating are carried out. Perform processing.

Example I N-(1-methylhephthyl)-N'-7enyl-p-phenylene diamine (compound C, trade name Ocinone 35)
, manufactured by Seiko Kagaku@) according to the above production example, N, 8A is 1
It was added in varying amounts of 0.2 to 7.5 parts by weight to 100 parts by weight of Carsen Black of 60 d/f/, and dried and heated at 150'C (Run
A1-5).

Example 2 The compound used in Example 1 was prepared according to the above production example, and N,
2.0 parts by weight was added to 100 parts by weight of Car N no black with SA of 160 m2'1, and dried and heated for 1 hour.
Conducted at 05°C to 250'C (Run 166-9
).

Example 3 2.0 parts by weight of the compound used in Example was mixed with N25A of 125 to 200 tr? according to the above production example. /f was added to 100 parts by weight of Carsen Black, and dried and heat-treated at 150°C (Run Al O~]2).

Example 4 2.0 parts by weight of the following compound was added to N and SA according to the above production example.
was added to 160 m1 of 100 parts by weight of the current Carsen Black, and dried and heated at 150°C (Run
Bian 13-17).

1) N-phenyl to N'-isopropyl-p-phenylenediamine (compound (a), trade name Tsukrak 83
0-NA, manufactured by Daien Shinko Kagaku Kogyo ■) ii) N-(
1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (compound (b), trade name Osinone 60,
(manufactured by Seiko Kagaku ■) iii) N,N'-diphenyl-p-phenylenediamine (compound), trade name: Tsukrak DP, manufactured by Ohmukai Shinko Kagaku Kogyo ■) iv) N-(a-methacryloyloxyl 2-hydroxy) propyl) -N'-phenyl-p-phenylenediamine (compound (e), trade name Tsukrak G-1, manufactured by Daien Shinko Kagaku Kogyo ■) v) p-(p-)luenesulfonylamito) diphenylamine (compound Comparative example] N, SA] 25 n? /f and 160 n? /f
Card d? y black was wetted with ordinary granulation water and dried at 150°C (Run A 18-1
9).

Rubber Compound Evaluation Results The Carsen blacks prepared in Buns A 1 to 19 above were mixed at the following rubber compounding ratios.

Natural rubber (R884N) 10 parts by weight Carzen black 45 parts by weight Stearic acid 3 parts by weight Zinc white
4 parts by weight Sulfur 1.5 parts by weight Vulcanization accelerator (OH2) 1y#Blue part Anti-aging agent (IPPA...Compound (A)) 1
Parts by Weight Comparative Example 2 A rubber compound was prepared by increasing only the anti-aging agent (compound (a)) by 1 part by weight (approximately 2.2 parts by weight 1 g relative to Carzen Black) in the above blending ratio ( Run
A 20, N! 8A = 160 rl/? ) Rubber property test conditions Vulcanization conditions of the compound = 145°C, 30 minutes abrasion test Using a two-row Zehn abrasion tester, the volume loss at a slip rate of 25% and 60 inches was measured, and according to the following formula: calculate.

Compensation wear index = (S/T) x] o o (%) S:
Volume loss T of IBBφ5 test piece: Volume loss of sample test piece Carsen black dispersion test: ASTM D-266
Measured by 3-82B method.

Other rubber properties: According to JI8 K2SO3-4974 and 6301-1975.

Force-Zenblack treatment conditions in Examples 1-4 and Comparative Example 1, and Examples 1-4 and Comparative Examples 1-2
The rubber properties are summarized in Table 1.

(Hereinafter, blank spaces) Effects of the present invention 1. Additional effect of amine anti-aging agent N, 8A Mo 160 tt? RunA18 with no amine anti-aging agent added in Kazen black /l
In contrast, in all of the examples of the present invention, the degree of dispersion of Kazen black was greatly improved, and along with this, the tensile strength and Lanzen abrasion resistance index were also significantly increased1). The added effect of is obvious.

Furthermore, in the examples, the MLvm was significantly reduced, indicating that the processability of the unvulcanized rubber was improved.

However, Run A 13 and Run A 2, in which approximately the same amount of compound (a) was added to Kazen black,
When compared with 0, un A 20 showed a slight decrease in MLvm, but there was almost no improvement in dispersibility or reinforcing properties, and the effect of the present invention was not achieved if it was simply added at the time of rubber compounding. It is shown that it does not.

2. Amount of amine anti-aging agent added: In Run A 1, 0.2 it part was added to 100 parts by weight of Kazenglac, compared to Run A without addition.
] Although there is a slight improvement in the dispersion degree compared to M.
Almost no improvement is seen in Lvm and reinforcing properties. In Run A 2, in which 0.5 parts by weight was added, significant improvement effects were seen in the degree of dispersion, MLvm, and reinforcing properties.

However, in Run A 5 where the added amount was 7.5 parts by weight, although the effect on dispersity and MLvm was observed,
It can be seen that the reinforcing properties, especially the 300% modulus and L60 properties, are greatly reduced (I), and the amount added to 100 parts by weight of Kazengrack needs to be 0.5 to 5.0 parts by weight.

3. Heat treatment temperature of amine-based anti-aging side addition casen black In Runs A 6 to 9 in which the heat treatment temperature was changed, the degree of dispersion tended to decrease slightly in the 105°C treatment of Run A 6, and from this temperature However, the effectiveness decreases at lower temperatures. In addition, when treated at 250°C, MLv
It can be seen that although a decrease in m is observed, there is a significant decrease in dispersibility and wear resistance index. Therefore, the heat treatment temperature needs to be in the range of 105°C to 200°C.

4. Effect of Carzen Black's N25A: N and SA are 1
25 Run A610 using glassen black
Comparing Run 41 G and Run A 19, there was a decrease in MLvm in Run 41 G with the addition of an antiaging agent, but no significant difference was observed in dispersibility and reinforcing properties.
The effect of the present invention is particularly significant for 130 tr? It is shown that this is remarkable in casen black of /f or more, and R
The effect is clear in un A 12.

Claims (1)

[Claims] 1. 100 parts by weight of carbon black having a nitrogen adsorption specific surface area of 130 m^2/g or more, and 0.5 to 5.0 parts by weight of at least one compound represented by the following general formula. A surface-modified carbon black comprising the above-mentioned compound added to the surface of the above-mentioned carbon black. General formula ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ However, -R in the general formula is one of (a) to (f) shown below. (b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (c) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (d) ▲ Numerical formulas, chemical formulas, tables, etc. There are ▼ (E) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (F) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ 2. 0. .5 to 5.0 parts by weight of an organic solvent solution or aqueous dispersion containing at least one compound represented by the following general formula is added and mixed, and the solvent or water is removed at a temperature of 150°C or higher and 200°C or lower. A method for producing surface-modified carbon black, which comprises removing, drying, and adding the compound to the surface of the carbon black. General formula ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ However, -R in the general formula is one of (a) to (f) shown below. (b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (c) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (d) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (E) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (F) ▲ There are mathematical formulas, chemical formulas, tables, etc. The surface-modified carbon black according to claim 2, which is poured into carbon black and heated the obtained wet granulated carbon black to a temperature of 150°C to 200°C to remove the solvent or water and dry it. manufacturing method.