JP3515636B2 - Carbon black graft polymer and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a carbon black graft polymer and a method for producing the same. More specifically, the present invention relates to a novel carbon black graft polymer characterized by reacting carbon black with a polymer containing a silicone component, and a method for producing the same.
The carbon black graft polymer of the present invention is an ink, a heat-sensitive transfer ink, an ink ribbon coating agent for heat-sensitive transfer, a back coating agent for a magnetic recording medium, a rubber composition, a sheet heating element, a toner for a copying machine, a paint, a liquid crystal color. Filter black matrix, artificial marble, colorants such as plastic molding materials, polymer modifiers such as polyolefin and polyester, lubricants, traction drive fluids,
It can be effectively used for electrorheological fluids and nonlinear optical materials.

[0002]

2. Description of the Related Art Carbon black has a coloring property, a conductivity,
Since it has excellent weather resistance and chemical resistance, it is widely used for various purposes such as a reinforcing agent and a filler for plastics and elastomers. However, carbon black
Since its shape is powdery or granular, it is rarely used alone and usually exhibits its characteristics by being uniformly dispersed in a solid base material such as rubber or resin or a liquid such as water or a solvent. . However, carbon black has a weak affinity for other substances, such as organic polymers, water, and organic solvents, as compared with the cohesive force between particles, so under normal mixing or dispersing conditions, uniform mixing or dispersion is achieved. It was extremely difficult to do. In order to solve this problem, the carbon black surface is coated with various surfactants and resins to improve the dispersibility of carbon black by increasing the affinity with a solid substrate or liquid. Many studies have been made.

The carbon black graft polymer obtained by polymerizing a polymerizable monomer in the coexistence of carbon black has an appropriate hydrophilicity and / or lipophilicity by appropriately selecting the type of the polymerizable monomer. It can be changed (for example, Japanese Patent Publication 42-
22047, Japanese Patent Publication No. 44-3826, Japanese Patent Publication No. 45-
No. 17248, Japanese Examined Patent Publication No. 46-26970). However, the yield of the carbon black graft polymer obtained by these methods is as low as several% to 10%, and most of them exist in the form of vinyl homopolymers, and the surface treatment efficiency of carbon black is extremely low. . Therefore, the affinity with other substances was not improved as expected, and the dispersion state was often different depending on the mixing or dispersion conditions.

In order to solve this problem, a carbon black graft polymer obtained by reacting a polymer having a reactive group such as an epoxy group or an aziridine group in the molecule with carbon black has been proposed (Japanese Patent Publication No. 2-2
No. 4868, Japanese Patent Publication No. 6-27269), the carbon black graft polymer had improved dispersibility in various substances.

However, this carbon black graft polymer has a problem that it cannot be provided with sufficient dispersibility in a medium having a low polarity, such as a hydrocarbon solvent or a silicone solvent. There are problems that the carbon content cannot be increased, that the electric insulation is not sufficiently high, and that grafting in an organic solvent is difficult. Therefore, this carbon black graft polymer could not be used in applications where a high carbon black content is desired, such as a black matrix for liquid crystal color filters. Further, when this carbon black graft polymer is used in an electrorheological fluid, there is a problem that the electrical durability is poor because the electrical insulating property is not sufficiently large.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a novel carbon black graft polymer and a method for producing the same.

Another object of the present invention is to provide a novel carbon black graft polymer prepared by reacting carbon black with a polymer containing a silicone component, and a method for producing the same.

Still another object of the present invention is to provide inks, thermal transfer inks, thermal transfer ink ribbon coating agents, back coating agents for magnetic recording media, rubber compositions, sheet heating elements, toners for copying machines, paints, Carbon that is useful for liquid crystal color filter black matrix, artificial marble, colorants such as plastic molding materials, polymer modifiers such as polyolefin and polyester, lubricants, traction drive fluids, electrorheological fluids and nonlinear optical materials. A black graft polymer and a method for producing the same are provided.

[0009]

The above objects are achieved by the following items (1) to ( 8 ).

(1) Polysiloxane represented by the general formula (1)
Polymer moieties having xane-containing structural units and carbon bra
The ratio of the black part is 100 times the carbon black part.
1 to 1000 parts by weight of the polymer portion relative to parts by weight.
Ri, carbon black graft polymer characterized by destruction potential is 0.5 kV / mm or more when dispersed in silicone oil.

[Chemical 10] (However, in the formula, A represents -COO- or a phenylene group.
R ¹ is a hydrogen atom or a methyl group, and R ² is a carbon number
1 to 6 alkylene groups, R ^{3 to} R ¹³ are the same or different.
Becomes an aryl group, an alkyl group having 1 to 6 carbon atoms, or charcoal
Each represents an alkoxyl group having a prime number of 1 to 10, and a represents
Any natural number, b and c are the same or different 0 to 10
, And d is an integer of 0 to 200, respectively. )

(2) The carbon black graft polymer according to the above (1), wherein the polymer portion is obtained by polymerization of a vinyl monomer and contains a main chain having a carbon-carbon bond.

(3) The average particle size is 0.001 to 0.5
The carbon black graft polymer according to (1) or (2) above , which is in the range of μm .

[0013]

(4) Obtained by polymerizing carbon black, a monomer mixture containing a monomer (a) having a reactive group for carbon black and a silicone-based macromer (b) represented by the general formula (2). a polymer, the carbon black 100 parts by weight per polymer 1-100 for
A method for producing a carbon black bluff polymer, which comprises reacting at a ratio of 0 part by weight.

[Chemical 11] (However, in the formula, B represents -COO- or a phenylene group, R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ represents an alkylene group having 1 to 6 carbon atoms, and R ^{16 to} R ²⁶ are the same or different. An aryl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms,
e and f show the same or different integer of 0-10, g shows the integer of 0-200, respectively. )

(5) The average particle size of carbon black is
It is within the range of 0.0005 to 0.4 μm.
The method for producing the carbon black graft polymer described above.

(6) Carbon black having a pH of less than 6
6. The acidic carbon black according to claim 4 or 5.
The method for producing a carbon black graft polymer.

[0017] (7) reactive group, an epoxy group in the molecule, thioepoxy group, wherein at least one selected from the group consisting of aziridine group and oxazoline group (4) in any one of - (6) A method for producing the described carbon black graft polymer.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

The "carbon black graft polymer" in the present invention means fine particles in which the polymer portion reacts with the carbon black portion. The carbon black graft polymer is a polymer in which primary particles of carbon black or several aggregates are reacted with a polymer.

Carbon black is usually several nm to several hundreds n.
It has a particle size of m. However, since carbon black has a large cohesive force between particles, it is usually handled as an aggregate having a particle size of several microns or more. This strong cohesive force
It is considered that this is due to the π-π interaction between the aromatic rings of carbon black. Due to this π-π interaction, carbon black exhibits high conductivity. Further, the cohesive force between carbon blacks is significantly higher than the affinity between carbon black and other media, and it is very difficult to disperse carbon blacks in the media in submicrons. On the other hand, in the carbon black graft polymer, the polymer portion effectively enters between the carbon black particles, and the cohesive force between the carbon blacks can be weakened. Furthermore, when the polymer part has an affinity for the medium,
The carbon black graft polymer can be submicron dispersed in the medium. Therefore, it can be said that when the polymer portion reacts more effectively with the carbon black portion, the carbon black graft polymer exhibits excellent electrical insulation and further exhibits excellent dispersibility.

The carbon black graft polymer of the present invention is a Don-Baptiste Donne.
t) et al. "Carbon Black" (1978)
It is presumed that the grafting is carried out on the carbon black part and the polymer part, as defined by the irreversible addition of the polymer to the substrate such as carbon black in May 1, published by Kodansha Co., Ltd.). To be done.

By carrying out an irreversible addition reaction, the polymer portion can be chemically bonded to the surface portion of the carbon black particles, whereby both of the above can be reliably bonded.

Such a chemical bond is estimated when the breakdown potential when the carbon black graft polymer is dispersed in silicone oil is 0.5 kV / mm or more. The breakdown potential is preferably 0.7 kV / m
It is m or more.

The breakdown potential defined in the present invention is measured by the following method. A dispersion in which 10 parts by weight of carbon black graft polymer was sufficiently dispersed in 90 parts by weight of polydimethylsiloxane (Shin-Etsu Silicone Oil KF96-20CS, manufactured by Shin-Etsu Chemical Co., Ltd.) was put between electrodes having a gap of 1 mm, and the temperature was kept at 25 ° C. AC external electric field (50H
z) is applied and the potential at which dielectric breakdown occurs is measured. However, as the polydimethylsiloxane, one having a carbon black graft polymer content of 1 kV / mm or more is used under the above conditions.

When the breakdown potential is less than 0.5 kV / mm,
There is a problem in that sufficient dispersibility cannot be imparted to the carbon black graft polymer. Breakdown potential is 0.5 kV
The reason why excellent dispersibility can be imparted in the case of / mm or more is as follows. A high breakdown potential is considered to indicate high electrical insulation between carbon blacks. The high electrical insulation between carbon blacks is considered to indicate that the π-π interaction between carbon blacks is small. That is, it is considered that the high breakdown potential indicates that the polymer effectively enters the surface of the primary particles of carbon black or the aggregates of several carbon blacks.

As a result of intensive studies, the present inventors have found that a carbon black graft polymer having a polymer portion containing a silicone component has more excellent dispersibility than conventional carbon black graft polymers. That is, it can be said that the carbon black graft polymer of the present invention reacts the carbon black and the polymer more effectively than the conventional carbon black graft polymer. Therefore, as compared with the conventional carbon black graft polymer, it has a feature that sufficient dispersibility can be imparted even in a medium having a low polarity and the carbon content in the carbon black graft polymer can be increased.

The carbon black graft polymer of the present invention contains a polymer portion containing a silicone component and a carbon black portion, and the breakdown potential when dispersed in silicone oil must be 0.5 kV / mm or more. Is.

The carbon black graft polymer of the present invention can be easily obtained by reacting carbon black with a polymer containing a reactive group for the carbon black and a silicone component.

The polymer portion of the present invention must contain a silicone component, and one having a silicone component in its side chain is particularly preferable. When the polymer portion does not contain a silicone component, there are problems that dispersibility in a medium having low polarity cannot be obtained and that the carbon content in the carbon black graft polymer cannot be increased.

The silicone component is a polydimethylsiloxane group, a partial alkyl group-substituted polydimethylsiloxane group, a partial aryl group-substituted polydimethylsiloxane group,
A portion containing a polyorganosiloxane such as tris (trialkylsiloxy) silylpropyl group.

The polymer portion of the present invention is preferably obtained by polymerization of a vinyl monomer and contains a main chain having a carbon-carbon bond. When the polymer portion contains a main chain having a carbon-carbon bond, the polymer and carbon black have a high affinity, so that the reaction between them can be effectively performed.

The polymer portion of the present invention preferably contains a polysiloxane structure represented by the general formula (1) as a structural unit of the silicone component. When the polymer portion does not have a polysiloxane-containing structural unit, the resulting carbon black graft polymer cannot have dispersibility in a medium having low polarity, and the carbon content in the carbon black graft polymer is increased. There are things you can't do.

[0038]

[Chemical 5]

(In the formula, A represents —COO— or a phenylene group, R ¹ represents a hydrogen atom or a methyl group,
R ² is an alkylene group having 1 to 6 carbon atoms, R ^{3 to} R ¹³ are the same or different and each represents an aryl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms, and a is a natural number. And b and c are the same or different and are 0
The integer of 10 is shown, d shows the integer of 0-200, respectively. ) The carbon black graft polymer of the present invention has an average particle size of 0.001 to 0.5 μm, particularly 0.005 to 0.2
It is preferably in the range of μm. The average particle size is 0.
A carbon black graft polymer of less than 001 μm is not industrially significant because carbon black as a raw material cannot be easily obtained. If the average particle size exceeds 0.5 μm, sufficient dispersibility may not be obtained.

In the carbon black graft polymer of the present invention, the ratio of the carbon black portion and the polymer portion containing a silicone component is 100 parts by weight of the former and 1 of the latter.
It is preferably from about 1000 parts by weight, particularly preferably from 5 to 500 parts by weight. If the latter is less than 1 part by weight, the resulting carbon black graft polymers may aggregate with each other, resulting in a problem that sufficient dispersibility in the medium cannot be obtained. On the other hand, when the latter exceeds 1000 parts by weight, the content of carbon black is small, and thus the coloring property and the polymer modifying property may be poor.

The method for producing the carbon black graft polymer of the present invention is not particularly limited. However, the carbon black graft polymer of the present invention can be easily and inexpensively obtained by reacting carbon black with a polymer containing a reactive group for carbon black and a silicone component. The reaction efficiency is increased by directly reacting the polymer with carbon black. When a monomer mixture that gives the polymer is polymerized in the presence of carbon black and an attempt is made to carry out a reaction with carbon black at the same time, the reaction efficiency may be lowered.

The polymer preferably contains a reactive group for carbon black and a silicone component.
When it does not contain a reactive group for carbon black,
The problem that the reaction with carbon black does not occur effectively may occur.

The polymer is preferably obtained by polymerizing a vinyl monomer and contains a main chain having a carbon-carbon bond. When the polymer has a main chain having a carbon-carbon bond, the affinity between the polymer and carbon black is large, so that the reaction with carbon black effectively occurs.

The polymer preferably contains a polysiloxane structure represented by the general formula (1) as a structural unit of the silicone component. When the polymer does not have a polysiloxane-containing structural unit, the resulting carbon black graft polymer cannot have dispersibility in a medium having low polarity, and the carbon content in the carbon black graft polymer cannot be increased. Sometimes.

[0045]

[Chemical 6]

(In the formula, A represents —COO— or a phenylene group, R ¹ represents a hydrogen atom or a methyl group,
R ² is an alkylene group having 1 to 6 carbon atoms, R ^{3 to} R ¹³ are the same or different and each represents an aryl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms, and a is a natural number. And b and c are the same or different and are 0
The integer of 10 is shown, d shows the integer of 0-200, respectively. The carbon black reactive group contained in the polymer is preferably at least one reactive group selected from the group consisting of an epoxy group, a thioepoxy group, an aziridine group and an oxazoline group. The reactive groups for carbon black are not necessarily limited to these, but when a polymer having a group other than these reactive groups is used, the type of carbon black that can be used may be limited. The reason why the polymer preferably has the above-mentioned reactive group is that regardless of the type and state of the carbon black that can be used, the carbon black and the polymer undergo an addition reaction with a very high reaction efficiency even under mild conditions. To do.

As the carbon black which can be used in the present invention, conventionally known ones can be used, and examples thereof include thermal black, channel black, furnace black, acetylene black and color black.

The carbon black preferably has a functional group such as a carboxyl group or a hydroxy group on its surface, and particularly preferably has a carboxyl group. Further, carbon black has a pH of less than 6, especially pH 1.
It is preferable to use carbon black of 5 to 5. Those obtained by oxidizing neutral or basic carbon black can also be suitably used as the carbon black of the present invention. When carbon black does not have a functional group such as a carboxyl group, or p
When it is at least H6, the reaction with the polymer may not be carried out effectively.

The average particle size of carbon black is 0.00
It is preferably in the range of 05 to 0.4 μm, particularly 0.001 to 0.2 μm. Average particle size is 0.0005μ
Since carbon black of less than m cannot be easily obtained, it has little industrial significance. If the average particle size exceeds 0.4 μm, the resulting carbon black graft polymer may not be able to have sufficient dispersibility.

In producing the carbon black graft polymer of the present invention, it is preferable to react carbon black having a carboxyl group with a polymer having a reactive group for the carboxyl group and a silicone component. Examples of the reactive group for the carboxyl group include an epoxy group, a thioepoxy group, an aziridine group and an oxazoline group, and at least one of them can be selected. Carbon black having a carboxyl group is easily available as acidic carbon black. The carboxyl group is an epoxy group,
The reaction with a thioepoxy group, an aziridine group or an oxazoline group is carried out in a high yield by thermal reaction. By this reaction,
A carbon black graft polymer suitable for the present invention is obtained.

The reaction for obtaining the carbon black graft polymer of the present invention includes, for example, a method of reacting a polymer containing a reactive group for carbon black and a silicone component with carbon black, or the presence of carbon black. It is also possible that the reaction for producing a polymer is performed below and the reaction of the polymer with carbon black is performed at the same time, and as a result, the polymer reacts with carbon black. However, in order to obtain a carbon black graft polymer with high reaction efficiency, it is preferable to use the former method.

The reaction between the carbon black and the polymer may be carried out in the presence of another substance such as a polymer not corresponding to the polymer, a polymerizable monomer and an organic solvent, or under the condition that other substance is not contained. May be done in. However, the reaction between the carbon black and the polymer is preferably carried out in an organic solvent. If the reaction is not carried out in an organic solvent, sufficient dispersibility may not be imparted to the resulting carbon black graft polymer.

Examples of the organic solvent include liquid paraffin, decane, decene, methylnaphthalene, decalin, kerosene, diphenylmethane, toluene, dimethylbenzene, ethylbenzene, diethylbenzene, propylbenzene, cyclohexane and partially hydrogenated hydrocarbons such as triphenyl. Silicone oils such as polydimethylsiloxane, partially octyl-substituted polydimethylsiloxane, partially phenyl-substituted polydimethylsiloxane, fluorosilicone oils; halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, bromobenzene, chlorobiphenyl, chlorodiphenylmethane; Daifloyl (Daikin Industrial Co., Ltd.), Dem Nam (Daikin Industry Co., Ltd.)
Fluoride such as; ethyl benzoate, octyl benzoate,
Ester compounds such as dioctyl phthalate, trioctyl trimellitate, dibutyl sebacate, ethyl (meth) actylate, butyl (meth) acrylate, and dodecyl (meth) acrylate; polyolefins, polyesters, polystyrenes, polycarbonates, A polymer compound such as a silicone resin may be mentioned.

As a method for producing a carbon black graft polymer, carbon black and a polymer containing a reactive group for carbon black and a silicone component are treated at a temperature of 40 to 300 ° C., preferably 70 to 250 ° C. A method of stirring and mixing for 5 to 10 hours, preferably 2 to 5 hours can be mentioned. If the reaction temperature is lower than 40 ° C, the reaction may not proceed, which is not preferable. Thirty
If the temperature exceeds 0 ° C, the polymer component may deteriorate.
Not preferable.

The reaction procedure is carbon black,
The polymer and, if necessary, an organic solvent and the like may be charged into a reaction apparatus and mixed with heating.

As the reaction apparatus, a kneading machine such as a stirring tank used for ordinary stirring and a ball mill, mixer, kneader used for kneading can be used.

As a method for obtaining a polymer containing a reactive group for carbon black and a silicone component,
For example, a method of polymerizing a monomer mixture containing a monomer (a) having a reactive group for carbon black and a silicon-based macromer (b) represented by the general formula (2) can be mentioned. The monomer mixture may contain other monomer (c), if necessary.

[0058]

[Chemical 7]

(In the formula, B represents —COO— or a phenylene group, R ¹⁴ represents a hydrogen atom or a methyl group,
R ¹⁵ is an alkylene group having 1 to 6 carbon atoms, R ^{16 to} R ²⁶ are the same or different and each represents an aryl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms, and e and f Are the same or different and each represents an integer of 0 to 10, and g represents an integer of 0 to 200. ) Examples of the monomer (a) include epoxy group-containing polymerizable monomers represented by the following chemical formulas.

[0060]

[Chemical 8]

[0061]

[Chemical 9]

(However, in these formulas, R represents hydrogen or a methyl group, and n is 0 or an integer of 1 to 20.) The monomer (a) is represented by, for example, the following chemical formula. A thioepoxy group-containing monomer can also be mentioned.

[0063]

[Chemical 10]

[0064]

[Chemical 11]

(However, in these formulas, R and n are the same as those of the epoxy group-containing polymerizable monomer.) Examples of the monomer (a) include the following chemical formulas (7) to (12). Examples thereof include aziridine group-containing polymerizable monomers represented by the formulas below.

[0066]

[Chemical 12]

[0067]

[Chemical 13]

[0068]

[Chemical 14]

[0069]

[Chemical 15]

[0070]

[Chemical 16]

[0071]

[Chemical 17]

Further, as the monomer (a), 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-
Oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-vinyl-4-ethyl-2-oxazoline, 2
-Vinyl-5-ethyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4
-Methyl-2-oxazoline, 2-isopropenyl-5
-Methyl-2-oxazoline, 2-isopropenyl-4
-Ethyl-2-oxazoline, 2-isopropenyl-5
-Ethyl-2-oxazoline, 2-isopropenyl-
Examples thereof include oxazoline group-containing monomers such as 4,5-dimethyl-2-oxazoline.

The monomer (a) is at least one selected from the group consisting of each epoxy group-containing polymerizable monomer, each thioepoxy group-containing polymerizable monomer and each aziridine group-containing polymerizable monomer described above. Different types can be used.

As the silicone macromer (b),
For example, (meth) acryloyl group-containing polydimethylsiloxane, styryl group-containing polydimethylsiloxane (meth)
Polymerizable polysiloxanes such as acryloyl group-containing partially octyl-substituted polydimethylsiloxane, styryl group-containing partially octyl-substituted polydimethylsiloxasan, styryl group-containing partially phenyl-substituted polydimethylsiloxane, and tris (trimethylsiloxy) silylpropyl (meth) acrylate Among these, 1 type (s) or 2 or more types can be used.

The monomer (c) is not particularly limited as long as it can be copolymerized with the monomer (a) and the silicone macromer (b), and examples thereof include styrene, o-methylstyrene and m-methyl. Styrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-
Styrene-based monomers such as butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene; (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-
(Meth) acrylic acid-based monomers such as butyl (meth) acrylate, isobutyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; ethylene, propylene, butylene, vinyl chloride, Vinyl acetate,
(Meth) acrylonitrile, (meth) acrylamide,
Examples thereof include N-vinylpyrrolidone, and one or more of these can be used. By using the monomer (c), the proportion of the main chain having a carbon-carbon bond in the polymer can be increased.

The monomer mixture contains 0.1 to 0.1 parts of the monomer (a).
50% by weight, the silicone macromer (b) is 10 to 99.9% by weight, and the monomer (c) is 0%.
It is preferable that the content of the monomers (a), (b) and (c) is 100% by weight.
% By weight.

When the proportion of the monomer (a) is less than 0.1% by weight, the reaction with carbon black may not be carried out effectively. When the proportion of the monomer (a) exceeds 50% by weight, gelation often occurs during the reaction with carbon black, and the resulting carbon black graft polymer may not be able to have sufficient dispersibility. Therefore, the preferable ratio of the monomer (a) is 1 to 20% by weight.

The proportion of the silicone macromer (b) in the monomer mixture is preferably 10 to 99.9% by weight, particularly preferably 50 to 95% by weight. 10% by weight of silicone macromer (b)
If it is less than the above range, the resulting carbon black graft polymer may not have desired dispersibility. on the other hand,
The proportion of silicone macromer (b) is 99.9% by weight
If it exceeds, the reaction with carbon black may not be carried out effectively.

The proportion of the monomer (c) in the monomer mixture is preferably 0 to 89.9% by weight, and 4 to 4
It is particularly preferably 9% by weight. When the proportion of the monomer (c) exceeds 89.9% by weight, the resulting carbon black graft polymer may not have desired dispersibility.

As a polymerization method for obtaining the polymer, a known polymerization method can be used. For example, a bulk polymerization method, a suspension polymerization method, an emulsion polymerization method, a solution polymerization method and the like can be mentioned. Among them, the solution polymerization method using a radical catalyst is preferable.

As the radical catalyst, any radical catalyst generally used for the polymerization of vinyl monomers can be used. Typical examples include azo compounds such as 2,2'-azobisisobutyronitrile and 2,2'-azobis (2,4-dimethylvaleronitrile); benzoyl peroxide, di-tert-butylperoxide. Oxide, ter
Examples thereof include peroxide compounds such as t-butyl peroctoate and tert-butyl peroxy-2-ethylhexanoate, which are usually 0.2 to 10 parts by weight, preferably 100 parts by weight of the monomer. Is used in the range of 0.5 to 5 parts by weight.

Polymerization is carried out by dissolving the monomer mixture and the radical catalyst in a solvent, and the reaction temperature is usually 40 to 200 ° C., preferably about 60 to 150 ° C. for 1 to 15 hours, preferably about 2 to 10 hours. Done.

Examples of the solvent include aliphatic hydrocarbons such as hexane, heptane and octane; aromatic hydrocarbons such as benzene, toluene and xylene; alcohols such as isopropyl alcohol and butanol; methyl isobutyl ketone,
Ketones such as methyl ethyl ketone; esters such as ethyl acetate, isobutyl acetate, amyl acetate and 2-ethylhexyl acetate; cell solves such as methyl cellosolve and ethyl cellosolve can be used.

After completion of the polymerization, the obtained solution of the polymer containing the silicone component having a reactive group can be used as it is for the reaction with carbon black, or the solvent of the solution can be distilled off to obtain the polymer. It can also be taken out and used.

As another method for obtaining the polymer that can be used in the present invention, for example, a compound having a reactive group for carbon black is reacted with a precursor polymer having a group capable of reacting with the compound, and the reaction is carried out. A method of introducing a functional group into the precursor polymer can be mentioned.

Examples of the above-mentioned compound include a compound having two or more kinds of the above-mentioned reactive groups for carbon black in the molecule, a compound having two or more kinds of the above-mentioned reactive groups for carbon black in the molecule, Examples thereof include compounds having in the molecule one or more types of the above-mentioned reactive groups for carbon black and a functional group other than the above-mentioned reactive groups.

However, the above-mentioned functional group is a group other than an epoxy group, a thioepoxy group, an aziridine group, an oxazoline group, and an oxazoline group, and is a group which can be reacted in the precursor polymer. Examples of the reactive group of the precursor polymer include an isocyanate group,
Examples thereof include amino group, carboxyl group, hydroxyl group, vinyl group and the like.

The molecular weight of the polymer is not particularly limited, but in consideration of the reaction effect on carbon black and workability during reaction with carbon black, the above-mentioned molecular weight is preferably in the range of 1,000 to 1,000,000, and It is preferably in the range of 5000 to 100,000.

The carbon black graft polymer of the present invention thus obtained has excellent dispersibility in various substances, for example, substances such as organic polymers and organic solvents, and has high electric insulation. In addition, it has many characteristics such as low water repellency and low viscosity due to the introduction of the siloxane moiety, excellent releasability, heat resistance, weather resistance, etc. and no low temperature brittleness. . Therefore, the carbon black graft polymer can be used as a coloring agent for conventionally known thermoplastic resins and thermosetting resins.

When the carbon black graft polymer is added to a thermoplastic resin, a toner having the above characteristics,
It can be used for films, fibers and the like. Also, when the carbon black graft polymer is added to a thermosetting resin, the carbon black graft polymer has many of the above-mentioned characteristics, and it is possible to solve the problem in the field conventionally used as carbon.

The carbon black graft polymer of the present invention is also used as a coating composition. Those capable of forming a strong coating film by adding to a binder used in the coating composition and coating on various substrates are preferable.
Such a binder component is, for example, a conventionally known thermoplastic resin, thermosetting resin or reactive resin, and one kind or a mixture of two or more kinds thereof is used depending on the application.

For example, by adding the carbon black graft polymer to the photocurable resin composition, it can be used as a black matrix for a color filter. Further, the carbon black graft polymer, in which carbon black is micro-dispersed, is suitable for various uses as a coloring agent, and is dispersed in a liquid phase, that is, for oil-based writing, information recording or printing. As the ink having good dispersion stability and excellent coloring power, the carbon black dispersion can be used as it is or by adding appropriate necessary components.

As described above, the carbon black graft polymer dispersion of the present invention can be used for plating, heat-sensitive transfer ink, paint and the like. Further, since it has the above-mentioned characteristics, it can be used as a thermal transfer ink ribbon coating agent, a magnetic recording medium and the like.

[0094]

EXAMPLES The carbon black graft polymer of the present invention will be described below with reference to examples, but the scope of the present invention is not limited to these examples.

Example 1 A flask equipped with a thermometer, a stirring blade and a cooling tube was charged with 200 parts by weight of toluene. There, methacryloyl group-containing polydimethylsiloxane (Silaplane FM0721 manufactured by Chisso Corporation, average molecular weight = about 500).
0) 130 parts by weight, 50 parts by weight of styrene, 20 parts by weight of glycidyl methacrylate and 10 parts by weight of benzoyl peroxide were charged, and the contents in the flask were stirred to form a uniform solution.

The solution thus obtained was heated to 70 ° C. and a polymerization reaction was carried out for 4 hours. The solvent of the obtained polymer solution is distilled off under reduced pressure to give a polymer (1) having an epoxy group in the molecule as a reactive group and a silicone component.
Got The molecular weight of this polymer was Mn = by GPC measurement.
It was 14,000.

Next, 15 parts by weight of a polymer (1) having an epoxy group as a reactive group and containing a silicone component and carbon black MA-100R (manufactured by Mitsubishi Chemical Corporation) (p.
15 parts by weight of H3.5) were kneaded using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) under the conditions of 160 ° C. and 100 rpm to react, and then pulverized to obtain a carbon black graft polymer (1). .

The average particle size of the carbon black graft polymer (1) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured by using a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). It was 0.045 μm.

Example 2 A flask equipped with a thermometer, a stirring blade and a cooling tube was charged with 200 parts by weight of toluene. There, methacryloyl group-containing polydimethylsiloxane (Silaplane FM0721 manufactured by Chisso Corporation, average molecular weight = about 500).
0) Charge 180 parts by weight, 20 parts by weight of glycidyl methacrylate and 10 parts by weight of benzoyl peroxide,
The contents in the flask were stirred to form a uniform solution.

The solution thus obtained was heated to 70 ° C. and a polymerization reaction was carried out for 4 hours. The solvent of the obtained polymer solution was distilled off under reduced pressure to obtain a polymer (2) having an epoxy group as a reactive group and containing a silicone component. The molecular weight of this polymer was Mn = 15000 by GPC measurement.

Next, in a separable flask equipped with a thermometer, a stirring blade and a cooling tube, 10 parts by weight of a polymer (2) having an epoxy group as a reactive group and containing a silicone component, carbon black MA-100R (Mitsubishi Chemical Co., Ltd. (pH 3.5) 15 parts by weight and xylene 75 parts by weight were dispersed, and 1500 parts by weight of SUS beads were placed in the flask. 1 while stirring at 600 rpm
The reaction was carried out at 20 ° C for 3 hours. After the reaction, the reaction contents and SU
S beads are separated, the solvent is distilled off from the reaction contents under reduced pressure,
Carbon black graft polymer (2) was obtained by pulverizing.

The average particle size of the carbon black graft polymer (2) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured by using a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). It was 0.05 μm.

Example 3 200 parts by weight of toluene was charged into a flask equipped with a thermometer, a stirring blade and a cooling tube. There, methacryloyl group-containing polydimethylsiloxane (Silaplane FM0711 manufactured by Chisso Corporation, average molecular weight = about 100)
0) 40 parts by weight, 140 parts by weight of styrene, 20 parts by weight of glycidyl methacrylate and 10 parts by weight of azobisisobutyronitrile were charged, and the contents in the flask were stirred to form a uniform solution.

The solution thus obtained was heated to 70 ° C. and a polymerization reaction was carried out for 4 hours. The solvent of the obtained polymer solution was distilled off under reduced pressure to obtain a polymer (3) having an epoxy group as a reactive group and containing a silicone component. The molecular weight of this polymer was Mn = 5000 by GPC measurement.

Next, 20 parts by weight of a polymer (3) having an epoxy group as a reactive group and containing a silicone component and 10 parts by weight of carbon black Carbon Black FWZ (manufactured by Degussa) (pH 2.5) were used. Using a mill (manufactured by Toyo Seiki Co., Ltd.), 160 ° C, 100 rp
After kneading and reacting under the condition of m, the mixture was cooled and pulverized to obtain a carbon black graft polymer (3).

The average particle size of the carbon black graft polymer (3) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured using a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). It was 0.04 μm.

Example 4 A flask equipped with a thermometer, a stirring blade and a cooling tube was charged with 400 parts by weight of deionized water in which 0.2 parts by weight of polyvinyl alcohol was dissolved. A polymerizable unit amount of 130 parts by weight of methacryloyl group-containing polydimethylsiloxane (Chilaplane FM0721, manufactured by Chisso Corporation, average molecular weight = about 5000), 60 parts by weight of styrene and 10 parts by weight of glycidyl methacrylate prepared in advance. A mixture prepared by dissolving 10 parts by weight of benzoyl peroxide was charged into the body and stirred at high speed to form a uniform suspension.
Then, the mixture was heated to 80 ° C., and stirring was continued at this temperature for 6 hours to carry out a polymerization reaction. The obtained polymer liquid was filtered, washed, and dried to obtain a polymer (4) having an epoxy group as a reactive group and containing a silicone component. The molecular weight of this polymer was Mn = 100000 by GPC measurement.

Then, in a separable flask equipped with a thermometer, a stirring blade and a cooling tube, 10 parts by weight of a polymer (4) having an epoxy group as a reactive group and containing a silicone component, carbon black MA-100R (Mitsubishi Chemical Co., Ltd. (pH 3.5) 15 parts by weight and xylene 75 parts by weight were dispersed, and 1500 parts by weight of SUS beads were placed in the flask. 1 while stirring at 600 rpm
The reaction was carried out at 20 ° C for 3 hours. After the reaction, the reaction contents and S
The US beads were separated, the solvent was distilled off from the reaction contents under reduced pressure, and the mixture was pulverized to obtain a carbon black graft polymer (4).

The average particle size of the carbon black graft polymer (4) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured by using a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). It was 0.08 μm.

Example 5 A flask equipped with a thermometer, a stirring blade and a cooling tube was charged with 200 parts by weight of toluene. There, methacryloyl group-containing polydimethylsiloxane (Silaplane FM0721 manufactured by Chisso Corporation, average molecular weight = about 500).
0) 130 parts by weight, styrene 50 parts by weight, 2-vinyl-
20 parts by weight of 2-oxazoline and 10 parts by weight of benzoyl peroxide were charged, and the content in the flask was stirred to form a uniform solution.

The solution thus obtained was heated to 70 ° C. and a polymerization reaction was carried out for 4 hours. The solvent of the obtained polymer solution was distilled off under reduced pressure to obtain a polymer (5) having an oxazoline group as a reactive group and containing a silicone component.
The molecular weight of this polymer was Mn = 1400 by GPC measurement.
It was 0.

Next, in a separable flask equipped with a thermometer, a stirring blade and a cooling tube, 5 parts by weight of a polymer (5) containing a silicone component having an oxazoline group as a reactive group and carbon black Special Black.
15 parts by weight of 100 (manufactured by Degussa) (pH 3.3) and 80 parts by weight of toluene are dispersed to prepare beads 1500 made of SUS.
Part by weight was charged into the flask. Rotation speed is 600 rpm
The grafting reaction was carried out at 120 ° C. for 3 hours with stirring. After the reaction was completed, the reaction contents and the SUS beads were separated, the solvent was distilled off from the reaction contents under reduced pressure, and the carbon black graft polymer (5) was obtained.

The average particle size of the carbon black graft polymer (5) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured using a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). It was 0.065 μm.

Example 6 15 parts by weight of polymer (1) having an epoxy group as a reactive group and containing a silicone component and carbon black MA-
5 parts by weight of 100R (manufactured by Mitsubishi Chemical Co., Ltd.) (pH 3.5) was kneaded using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) under the conditions of 160 ° C. and 100 rpm, reacted, cooled, and ground. A carbon black graft polymer (6) was obtained.

The average particle size of the carbon black graft polymer (6) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured using a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). It was 0.10 μm.

Comparative Example 1 200 parts by weight of toluene was charged into a flask equipped with a thermometer, a stirring blade and a cooling tube. There styrene 18
0 parts by weight, 20 parts by weight of glycidyl methacrylate and 10 parts by weight of benzoyl peroxide were charged, and the content in the flask was stirred to form a uniform solution.

The solution thus obtained was heated to 70 ° C. and a polymerization reaction was carried out for 4 hours. The solvent of the obtained polymer solution was distilled off under reduced pressure to obtain a comparative polymer (1) having an epoxy group as a reactive group. The molecular weight of this polymer was Mn = 6500 by GPC measurement.

Next, 15 parts by weight of the polymer (1) for comparison having an epoxy group as a reactive group thus obtained and carbon black MA-100R (manufactured by Mitsubishi Chemical Corporation) (pH 3.
5) 15 parts by weight of the product was kneaded with a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) under the conditions of 160 ° C. and 100 rpm to react, and then pulverized to obtain a carbon black composition (1) for comparison. It was

The average particle size of the comparative carbon black composition (1) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured by a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). ) Was 0.18 μm.

Comparative Example 2 200 parts by weight of toluene was charged into a flask equipped with a thermometer, a stirring blade and a cooling tube. There, methacryloyl group-containing polydimethylsiloxane (Silaplane FM0721 manufactured by Chisso Corporation, average molecular weight = about 500).
0) 150 parts by weight, 50 parts by weight of styrene and 10 parts by weight of benzoyl peroxide were charged, and the contents in the flask were stirred to form a uniform solution.

The solution thus obtained was heated to 70 ° C. and a polymerization reaction was carried out for 4 hours. The solvent of the obtained polymer solution was distilled off under reduced pressure to obtain a polymer (2) containing a silicone component for comparison. The molecular weight of this polymer is GPC
According to the measurement, Mn = 15000.

Next, 15 parts by weight of polymer (2) containing a silicone component for comparison and carbon black MA-100.
R (manufactured by Mitsubishi Chemical Co., Ltd.) (pH 3.5) and 15 parts by weight using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) 1
After kneading and reacting at 60 ° C. and 100 rpm,
It was crushed to obtain a carbon black composition (2) for comparison.

The average particle size of the comparative carbon black composition (2) in silicone oil (KF96-10CS manufactured by Shin-Etsu Chemical Co., Ltd.) was measured by a sedimentation type particle size distribution meter (CP-3 manufactured by Shimadzu Corporation). ) Was 0.15 μm.

Example 7 Carbon black graft polymers (1) to (6) obtained in Examples 1 to 6 and Comparative Examples 1 and 2, carbon black compositions (1) and (2) for comparison and carbon black. A dispersibility test of MA-100R was performed. For the dispersibility test, xylene, hexane and silicone oil (KF96-20C manufactured by Shin-Etsu Chemical Co., Ltd.) are used as dispersion media.
S) 30 parts by weight of the obtained carbon black graft polymer, 30 parts by weight of the carbon black composition for comparison, and 30 parts by weight of carbon black for comparison were added to 70 parts by weight of each, and dispersed for 30 minutes at 20 ° C. in an ultrasonic vibrator to obtain a dispersion liquid. The dispersed state was observed. The results are shown in Table 1.

Example 8 Carbon black graft polymers (1) to (6) obtained in Examples 1 to 6 and Comparative Examples 1 and 2, carbon black compositions (1) and (2) for comparison and carbon black. The Soxhlet extraction test of MA-100R was performed.
In the Soxhlet extraction test, toluene and hexane were used as the extract. The results are shown in Table 1.

Example 9 Carbon black graft polymers (1) to (6) of the present invention obtained in Examples 1 to 6 and comparative carbon black compositions (1) to 1 obtained in Comparative Examples 1 and 2 The breakdown potential test of (2) and carbon black MA-100R was performed as follows. The carbon black graft polymer of the present invention or a carbon black composition for comparison, and Shin-Etsu Silicone Oil KF96-20C in which 10 g of carbon black is polydimethylsiloxane of 20 cSt.
90 g of S (manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed and dispersed in an ultrasonic vibrator (Biomixer (MB-4) manufactured by Nippon Seiki Seisakusho Co., Ltd.) at 20 ° C. for 30 minutes to obtain a dispersion liquid.

The dispersion thus prepared was placed in a rotational viscometer with a coaxial electric field (manufactured by Cordix), and the inner / outer cylinder gap was 1.0.
mm, a shear rate of 100 mm / sec, and an AC external electric field (50 Hz) were applied under the conditions of 25 ° C., and the potential at which dielectric breakdown occurred was measured. The results are shown in Table 2. The breakdown potential of the polydimethylsiloxane used was 7 kV / mm.

[0128]

[Table 1]

[0129]

[Table 2]

[0130]

As described above, the carbon black graft polymer according to the present invention comprises a polymer portion containing a silicone component and a carbon black portion, and the polymer portion reacts with the carbon black portion. Therefore, the affinity with various substances has been improved, and for example, since the dispersibility in substances such as organic polymers and organic solvents is remarkably excellent, inks, copier toners, paints, plastic molding materials, It can be suitably used for colorants such as black matrix of color filters for liquid crystals, modifiers for various polymers such as polyolefin and polyester, traction drive fluids, lubricants, non-linear optical materials and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruhisa Nagashima 12-25 Kannondai, Tsukuba-shi, Ibaraki Nihon Shokubai Co., Ltd. (56) References JP-A-5-257331 (JP, A) JP-A-4 -68041 (JP, A) JP-A 6-166819 (JP, A) JP-A-62-182759 (JP, A) JP-A 5-241377 (JP, A) (58) Fields investigated (Int.Cl) . ⁷ , DB name) C08F 292/00 C08F 2/44

Claims (7)

(57) [Claims] 1. The ratio of the polymer portion having the polysiloxane-containing structural unit represented by the general formula (1) to the carbon black portion is such that the polymer portion is 1 to 100 parts by weight of the carbon black portion. It is 1000 parts by weight, and has a breakdown potential of 0.5k when dispersed in silicone oil.
A carbon black graft polymer having a V / mm or more. [Chemical 1] (However, in the formula, A represents -COO- or a phenylene group, R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkylene group having 1 to 6 carbon atoms, and R ^{3 to} R ¹³ are the same or different. Each represents an aryl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms, a is an arbitrary natural number, and b and c are the same or different, 0 to 10
, And d is an integer of 0 to 200, respectively. ) 2. The carbon black graft polymer according to claim 1, wherein the polymer portion is obtained by polymerization of a vinyl monomer and contains a main chain having a carbon-carbon bond. 3. The carbon black graft polymer according to claim 1, which has an average particle diameter of 0.001 to 0.5 μm. 4. Carbon black, a monomer (a) having a reactive group for carbon black, and a general formula (2).
And a polymer obtained by polymerizing a monomer mixture containing the silicone macromer (b) represented by the formula (1) are reacted at a ratio of 1 to 1000 parts by weight with respect to 100 parts by weight of the carbon black. And a method for producing a carbon black bluff polymer. [Chemical 2] (However, in the formula, B represents -COO- or a phenylene group, R ¹⁴ represents a hydrogen atom or a methyl group, R ¹⁵ represents an alkylene group having 1 to 6 carbon atoms, and R ^{16 to} R ²⁶ are the same or different. An aryl group, an alkyl group having 1 to 6 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms,
e and f show the same or different integer of 0-10, g shows the integer of 0-200, respectively. ) 5. The average particle size of carbon black is 0.0.
The method for producing a carbon black graft polymer according to claim 4, wherein the carbon black graft polymer is in the range of 005 to 0.4 μm. 6. The method for producing a carbon black graft polymer according to claim 4, wherein the carbon black is an acidic carbon black having a pH of less than 6. 7. A reactive group is an epoxy group, thioepoxy group, preparation of a carbon black graft polymer according to any one of claims 4 to 6 is at least one selected from the group consisting of aziridine group and oxazoline group Method.