JPH04190244A - Toner binder for electronic photography - Google Patents

Abstract

PURPOSE:To obtain a binder having preferable properties for HO and MF by composing it of a high molecular weight copolymer including a specified molecular weight part, a low molecular weight polymer, and a medium molecular weight copolymer, and forming it as a resin mixture of which weight-averaged molecular weight, and a ratio of the weight-averaged molecular weight to a number-averaged molecular weight are specified. CONSTITUTION:A binder includes a high molecular weight copolymer including a part of a molecular weight of more than 300,000, a low molecular weight polymer including a part of a molecular weight of 1,000 - 30,000, and a medium molecular weigh copolymer including a part of a molecular weight of 50,000 - 100,000, and it is formed as a resin mixture having a weight-averaged molecular weight of 200,000 - 1,000,000, and a ratio of the weight-average molecular weight to a number-averaged molecular weight of 40 - 100. Monomers for composing the high molecular weight copolymer and the medium molecular weight polymer comprise more than two sorts of styrene or a styrene substitution product, and acrylic acid ester and/or methacrylic acid ester, and monomers for composing the low molecular weight polymer are selected among I. styrene and styrene substitution product, and II. more than two sorts of styrene or styrene substitution product, and acrylic acid ester and/or methacrylic acid ester.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a toner binder for electrophotography.

(Prior Art and Problems to be Solved by the Invention) In electrophotography, an electrostatic latent image is visualized using toner to form a toner image on paper or the like, but in order to fix this toner image,
A method using a heat roll is widely adopted. In this method, the minimum fixing temperature (hereinafter abbreviated as MF) is desirably low, and the temperature at which offset to the heat roll occurs (hereinafter abbreviated as HO) is desirably high.

In order to satisfy these two demands, it has been proposed in the past that the molecular weight distribution of the toner binder should be wide ranging from low molecular weight to high molecular weight (for example, Japanese Patent Publication No. 60-20411, Japanese Patent Publication No. 51-23354). Public bulletin).

In the above, for example, a crosslinking agent is used to broaden the molecular weight distribution higher.

However, as mentioned above, when the molecular weight distribution is broadened to a higher extent by the use of a crosslinking agent, there is a drawback that the MF increases.

It is also possible to consider a method in which a high molecular weight portion is produced by suspension polymerization without using a crosslinking agent, and then mixed and dissolved in a solvent with a separately produced low molecular weight polymer.

However, in the above method, since the molecular weights are widely different from each other, it is difficult to achieve complete uniformity, and coloring materials such as carbon blanks and additives such as charge control agents are not uniformly dispersed during toner production. It has the disadvantage that the charging characteristics are not stable during running during copying, causing toner fogging and scattering.

The present invention solves the above problems, and it
A first object of the present invention is to provide an electrophotographic toner binder comprising a polymer having a wide molecular weight distribution and having favorable properties (low MF and high HO).

A second object of the present invention is to provide an electrophotographic toner binder in which coloring materials such as carbon black and additives such as a charge control agent are uniformly dispersed during toner production, and which has excellent running characteristics during copying. The purpose of

(Means for Solving the Problems) The present invention has the following features: (a)1. A high molecular weight copolymer (A) containing a portion with a molecular weight of 300,000 or more in the molecular weight distribution, (1) a low molecular weight polymer (B) containing a portion with a molecular weight of 1000 to 30,000 in the molecular weight distribution, and III, 0 molecular weight. In cloth, molecular weight 5
It contains an intermediate molecular weight copolymer (C) containing a portion of 200,000 to 200,000, and has a weight average molecular weight of 200,000 to 1,000,000, and a ratio of weight average molecular weight to number average molecular weight of 40,000 to 1,000,000.
-100, wherein (b) the monomers constituting the high molecular weight copolymer (A) and the intermediate molecular weight polymer (C) are I, styrene or a styrene substituted product, respectively; II, acrylic esters and/or methacrylic esters, and (C) the monomer constituting the low molecular weight polymer (B) is
selected from two or more monomers of I, styrene or styrene-substituted product, and II, styrene or styrene-substituted product, and acrylic esters and/or methacrylic esters, (d) high molecular weight copolymer The polymer (A) is obtained by copolymerizing the monomers in the presence of a polyfunctional polymerization initiator CD), and (e) the polyfunctional polymerization initiator (D) is copolymerized within 1.1 molecules. , a polyfunctional polymerization initiator having two or more peroxide groups; If, one or more peroxide groups in one molecule;
(f) the intermediate molecular weight copolymer (C) is selected from the high molecular weight copolymer (A) and the low molecular weight polymer ( A toner binder for electrophotography characterized in that monomers are copolymerized in the presence of B) substantially without using a solvent.

In addition, in the present invention, in dynamic viscoelastic properties in a molten state at 150°C, the absolute value of the complex viscosity at a frequency of 20 Hz |η* (20)l is set to 1000 to 15000p.
oise, the absolute value of the complex viscosity at 17 |η*(1
)l is 5,000 to 60,000 poise, and the ratio of the above absolute values |η*(20)|/|η*(1)l is 0.
It is preferably 20 or less.

The present invention will be explained in detail below.

The binder of the present invention comprises a high molecular weight copolymer (A) containing a portion with a molecular weight of 300,000 or more in the molecular weight distribution, and a low molecular weight copolymer (B) containing a portion with a molecular weight of 1000 to 30,000 in the molecular weight distribution. ) and ■In the 1-molecule lid distribution, the molecular weight is 50,000 to 10
an intermediate molecular weight copolymer (C) containing 10,000 parts;
The weight average molecular weight is 200,000 to 1,000,000, and the ratio of weight average molecular weight to number average molecular weight is 40 to 1,000.
This is a resin mixture that is

The monomers constituting the high molecular weight copolymer (A) and the intermediate molecular weight polymer (C) are, respectively, I, styrene or a styrene substituted product, and II, acrylic esters and/or methacrylic esters. There are said to be two or more types.

Furthermore, the monomers constituting the low molecular weight polymer (B) are of two types: I, styrene or styrene-substituted product, and II, styrene or styrene-substituted product, and acrylic esters and/or methacrylic esters. selected from the above monomers.

The above-mentioned styrene or styrene substituted product includes styrene,
Alkylstyrenes (e.g. α-methylstyrene, p-
methylstyrene), etc.

Preferably it is styrene.

The above acrylic esters and/or methacrylates) LtW
As I esters, that is, (meth)acrylic esters, methyl (meth)acrylate, ethyl (meth)
Alkyl esters in which the alkyl group has 1 to 18 carbon atoms, such as acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; hydroxylethyl (meth)acrylate, etc. Hydroxyl group-containing (meth)acrylate; dimethylaminoethyl (
Amino group-containing (meth)acrylates such as meth)acrylate and diethylaminoethyl (meth)acrylate;
Examples include nitrile group-containing (meth)acrylic compounds such as acrylonitrile and (meth)acrylic acid.

Among these, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (
meth)acrylic acid and mixtures of two or more thereof.

The monomers constituting the high molecular weight copolymer (A), low molecular weight polymer (B), and intermediate molecular weight polymer (C) include vinyl esters other than (meth)acrylic acid esters, aliphatic A hydrocarbon vinyl monomer or the like may be used in combination.

Examples of the vinyl ester include vinyl acetate and vinyl propionate, and examples of the aliphatic hydrocarbon vinyl monomer include butadiene.

The high molecular weight copolymer (A) can be obtained by copolymerizing the above monomers in the presence of a polyfunctional polymerization initiator (D) having a polyfunctional structure. Copolymerization methods include solution polymerization,
Any method such as bulk polymerization, suspension polymerization, and emulsion polymerization can be selected.

The above-mentioned polyfunctional polymerization initiator (D) includes: 1. A polyfunctional polymerization initiator having two or more peroxide groups in one molecule; U. One or more peroxide groups in one molecule; 1
and a polyfunctional polymerization initiator having three or more polymerizable unsaturated groups.

As the polyfunctional polymerization initiator of I above, 1.1-jet
-butylperoxy-3,3,5-)lyntylcyclohexane, 1,3-bis-(t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-(t-
butylperoxy)hexane, 2゜5-dimethyl-2,
5-di(t-butylperoxy)hexyne-3, tris-(t-butylperoxy)triazine, 1.1-di-t-butylperoxycyclohexane, 2.2-di-
t-butylperoxybutane, 4.4-di-t-butylperoxyvaleric acid-n-butyl ester,
Di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate, di-t-butylperoxytrimethyladibate, 2.2-bis-
(4,4-di-t-butylperoxycyclohexyl)
Examples include propane, 2,2-t-butylperoxyoctane, and various polymer oxides.

Among these, preferred are 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane,
1.1-di-t-butylperoxycyclohexane, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate and 2.2-bis-(4,4-di-t-butyl peroxycyclohexyl)propane.

Examples of the polyfunctional polymerization initiator (2) include diallylperoxydicarbonate, t-butylperoxymaleic acid, t-butylperoxyallyl carbonate, and t-butylperoxyisopropyl fumarate.

Among these, preferred is t-butyl peroxyallyl carbonate.

When the high molecular weight copolymer (A) is obtained by solution polymerization, examples of the solvent include cycloalkane solvents such as cyclohexane; benzene, toluene, xylene, ethylbenzene,
Aromatic solvents such as cumene; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc. are used.

In particular, in order to increase the molecular weight of the high molecular weight copolymer (A), cycloalkane solvents and aromatic solvents are preferred among the above solvents.

In addition, when obtaining the high molecular weight copolymer (A) by suspension polymerization, an inorganic acid dispersant such as calcium carbonate or calcium phosphate, or an organic dispersant such as polyvinyl alcohol or methylated cellulose is used to obtain the monomer. polymers can be polymerized in water.

The copolymerization temperature of the high molecular weight copolymer (A) is usually 50 to 15
The temperature is 0°C, preferably 60 to 120°C, and the copolymerization is preferably carried out in an atmosphere of an inert gas such as nitrogen.

During copolymerization of the high molecular weight copolymer (A), a polyfunctional monomer having two or more polymerizable double bonds is gelled to increase the molecular weight of the high molecular weight copolymer (A). It may be added in an amount (0.1 mol % or less) that does not generate.

Examples of the polyfunctional monomer include di- or polyvinyl compounds (divinylbenzene, divinyltoluene, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, etc.).

Among these, divinylbenzene and 1,6
-hexanediol diacrylate.

When producing the low molecular weight polymer (B), two or more monomers: I, styrene or styrene-substituted product; II, styrene or styrene-substituted product, and acrylic esters and/or methacrylic esters; Polymerization is carried out by a solution polymerization method by dropping a monomer selected from the following alone, or by dropping a monomer and a polymerization initiator, or a solution consisting of a monomer, a polymerization initiator, and a solvent. .

Examples of the polymerization initiator during the polymerization of the low molecular weight polymer (B) include azo polymerization initiators such as azobisisobutyronitrile, azobisvaleronitrile, and azobiscyanovaleric acid; benzoyl peroxide, di-t-butyl Organic peroxide polymerization initiators such as peroxide and t-butyl peroxybenzoate are used.

Preferred are azobisisobutyronitrile, di-t-butyl peroxide, and t-butyl peroxybenzoate.

The above-mentioned solvents during polymerization of the low molecular weight polymer (B) include cycloalkane solvents such as cyclohexane; aromatic solvents such as benzene, toluene, xylene, ethylbenzene, and cumene; and ester solvents such as ethyl acetate and butyl acetate. ;
Ether-based P such as methyl cellosolve and ethyl cellosolve
A agent etc. are used.

Preferences are toluene, xylene, and ethylbenzene.

The polymerization temperature is usually 80 to 220°C, preferably 10
The temperature is 0 to 210°C, and the polymerization is preferably carried out in an atmosphere of an inert gas such as nitrogen.

Intermediate molecular weight copolymer (C) is high molecular weight copolymer (A)
It can be obtained by copolymerizing monomers in the presence of and a low molecular weight polymer (B), substantially without using a solvent.

The polymerization is usually carried out by thermal polymerization without using a polymerization initiator, but the polymerization may be carried out using a polymerization initiator. Examples of the polymerization initiator are the same as those of the polyfunctional polymerization initiator (D) used in the polymerization of the high molecular weight copolymer (A) or the polymerization initiator used in the polymerization of the low molecular weight polymer (B). be.

When producing the binder of the present invention, usually, as described above, the high molecular weight copolymer (A) and the low molecular weight polymer (B) are separately polymerized and mixed in a solution state or a molten state. . Thereafter, by adding monomers such as styrene or styrene substitutes and (meth)acrylic acid esters and performing bulk polymerization, a high molecular weight copolymer (A) and a low molecular weight polymer (B) are obtained. In the presence of an intermediate molecular weight copolymer (
C) is polymerized to produce a binder.

In addition, after polymerizing the high molecular weight copolymer (A), the monomer for the low molecular weight polymer (B) is added continuously or intermittently in the presence of the high molecular weight copolymer (A) in a solution or molten state. to polymerize the low molecular weight polymer (B), and then in the presence of the high molecular weight copolymer (A) and the low molecular weight polymer (B),
A binder can also be produced by polymerizing the intermediate molecular weight polymer (C).

The proportion of each monomer constituting the high molecular weight copolymer (A) is usually 98 to 50% of styrene or styrene substituted product.
% by weight, preferably 95-60% by weight, (meth)acrylic acid ester usually 2-50% by weight, preferably 5-40% by weight, other monomers 0-10% by weight, preferably is 0 to 5% by weight.

In addition, the proportion of each monomer when polymerizing the low molecular weight polymer (B) is usually 70 to 70% for styrene or a styrene substituted product.
100% by weight, preferably 80 to 100% by weight, (meth)acrylic acid ester usually 0 to 30% by weight, preferably 0 to 20% by weight, and other monomers usually 0 to 100% by weight.
10% by weight, preferably 0-5% by weight.

Furthermore, the proportion of each monomer constituting the intermediate molecular weight polymer (C) is usually 60 to 9 styrene or a styrene substituted product.
5% by weight, preferably 70-90% by weight, (meth)acrylic acid ester usually 5-40% by weight, preferably 10-30% by weight, 0-10% by weight of other monomers,
Preferably it is 0 to 5% by weight.

In the binder, a high molecular weight copolymer (
The proportion of the portion having a molecular weight of 300,000 or more derived from A) is usually 10 to 50 area %, preferably 15 to 45 area %. If the portion with a molecular weight of 300,000 or more is less than 10% by area,
It is difficult to obtain sufficient HO, and if it exceeds 50 area%, MF
is too high, which is not desirable.

In the binder, a low molecular weight polymer (B
) is usually 35 to 90 area%, preferably 40 to 85 area%.
It is. If the portion having a molecular weight of 1000 to 30,000 is less than 50 area %, the MF becomes too high, and if it exceeds 90 area %, it becomes difficult to obtain sufficient HO, which is not preferable.

In the binder, a medium molecular weight polymer (
The proportion of the portion with a molecular weight of 50,000 to 200,000 derived from C) is usually 10 to 30 area%, preferably 12 to 25 area%.
It is. If the portion with a molecular weight of 50,000 to 200,000 is less than 10 area%, coloring materials such as carbon black and additives such as charge control agents will not be uniformly dispersed, and if it exceeds 30 area%, the weight average molecular weight and number will be affected. The value of the ratio to the average molecular weight becomes small, and the fixing temperature range becomes narrow, which is not preferable.

In addition, the area % is the gel permeation of the binder.
The area of the part with a molecular weight of 300,000 or more, the area of the part with a molecular weight of 1,000 to 30,000, or the area of the part of the part with a molecular weight of 50,000 to 200,000 to the total area on a chromatography (hereinafter abbreviated as GPC) chart. percentage.

In addition, when measuring by GPC, tetrahydrofuran (hereinafter abbreviated as THF) was used as a solvent, and the temperature was 40°C.
Measured in °C. Note that the measurement is performed using standard polystyrene as a reference.

Further, the glass transition point (Tg) of the entire binder of the present invention is usually 40 to 80°C, preferably 45 to 70°C. If the glass transition point (Tg) is less than 40°C, the storage stability of the toner will be poor, and if it exceeds 80°C, the MF
This is undesirable because the toner becomes unsuitable for practical use as a toner.

Weight average molecule of the binder of the present invention! (nw) is usually 200,000 to 1,000,000, preferably 250,000 to 500,000. In addition, if the weight average molecular weight is less than 200,000, sufficient H
It is difficult to obtain O, and if it exceeds 1 million, the MF becomes too high, which is not preferable.

Note that the weight average molecular weight is measured by GPC using THF as a solvent.

Molecular weight distribution of the binder of the present invention [weight average molecular weight (M
w) and the number average molecular weight (!In) (Mw/M
n ) is usually 40 to 100, preferably 45 to 80. In addition, if the molecular weight distribution is less than 40, the difference between MF and HOO becomes small, which is not preferable. or,
If the molecular weight distribution is 100 or more, it is difficult to manufacture and is not preferable.

Furthermore, in the binder of the present invention, in dynamic viscoelastic properties in a molten state at 150°C, the absolute value of the complex viscosity at a frequency of 20 Hz |η*(20)1 is set to 1000 to
The absolute value of the complex viscosity at 15,000 poise and 17 | η * (1) l is set to 5,000 to 60,000 poise, and the value of the ratio of the above absolute values | η * (20) l / l η *
(1) It is preferable that l is 0.20 or less.

The reason why the dynamic viscoelastic properties were set as described above is as follows.

That is, copying machines range from low-speed machines (approximately 10 sheets/min) to high-speed machines (70 sheets/min), and the higher the speed, the shorter the toner heating time and the smaller the amount of heat given to the toner.

In this case, even if the amount of heat given to the toner is small, unless the viscosity of the toner is lowered by this amount of heat, the toner will not be well fixed on paper or the like, and the toner will not be compatible with high-speed machines.

By the way, in a copying machine, when toner is fixed onto paper or the like by a heat roll, the toner is subjected to shearing force by the heat roll and press roll.

In this case, the shearing rate applied to the toner differs depending on the copying speed.

Therefore, in order to handle everything from low-speed machines to high-speed machines, the temperature must be 150°C.
It is necessary that the viscosity decreases as the shear rate to which the toner is subjected in its molten state increases.

That is, in the binder of the present invention, the higher the shearing rate to which the toner is subjected, the more the desired viscosity is achieved, so that it can be applied to a wide range of copying speeds, from low speed machines to high speed machines.

The ratio of the constituent components of the electrophotographic toner to which the binder of the present invention is used is such that the binder is usually 50 to 95% by weight, and the binder contains known coloring materials (carbon black, iron black, benzidine yellow, quinacridone, rhodamine B, phthalocyanine). etc.) is usually 5 to 10% by weight, and magnetic powder (ferromagnetic metal powder such as iron, cobalt, nickel, etc., or compound such as magnetite, hematite, ferrite, etc.) is
Usually, it is 0 to 50% by weight.

Furthermore, various additives such as charge control agents (metal complexes, nigrosine, etc.), lubricants (polytetrafluoroethylene, low molecular weight polyolefins, fatty acids, or metal salts or amides thereof, etc.) may be added to the toner. . The proportion of these additives in the toner is usually 0 to 5% by weight.

The electrophotographic toner is produced by dry blending the above components, melting and kneading them, then coarsely pulverizing them, finally pulverizing them using a jet pulverizer or the like, and further classifying them.
It is obtained as fine particles with a particle size of 5 to 20 μm.

The above electrophotographic toner is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, etc., as necessary, and used as a developer for an electrical latent image. or,
Hydrophobic colloidal silica fine powder is sometimes added to electrophotographic toners to improve the fluidity of the powder.

Toner for electrophotography is used by being fixed on a support (paper, polyester film, etc.), and a known heat roll fixing method can be used for fixing.

[Examples] Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited by the Examples.

In the examples, all parts represent parts by weight.

Moreover, the conditions for molecular weight measurement by GPC are as follows.

Equipment: Tosoh HLC-802A column:
Two Tosoh TSKgelGMH6 Measurement temperature: 40℃ Sample solution = 0.5% by weight THF? 8 liquid solution injection amount:
200μ! Detection device: Refractive index detector The molecular weight calibration curve was created using standard polystyrene.

Furthermore, the conditions for measuring dynamic viscoelasticity are as follows.

Equipment: Rheometri
cs Inc, U,S.

A. RDS-7700ff dynamic spectrometer test fixture chair: 25mΦ cone plate Measurement temperature: 1
50°C Measurement frequency: 20 Hz (125,6 rad/se
c) and I Hz (6,28 rad/sec) Strain rate: 5% fixed (Comparative Example 1) 1. Production of high molecular weight copolymer (A) 450 parts of water and polyvinyl alcohol were placed in the glass autoclave of 21. Add 50 parts of a 2% by weight aqueous solution of (PVA235 manufactured by Kuraray), add a mixture of 260 parts of styrene, 76 parts of n-butyl acrylate, and 1.3 parts of lauroyl peroxide and stir to suspend. It was made into a liquid.

After the inside of the autoclave was sufficiently purged with nitrogen, the temperature was raised to 80°C to start polymerization. The polymerization was continued while maintaining the same temperature, and the temperature was raised to 9.5° C. after 20 hours. After holding at the same temperature for 2 hours, the temperature was further raised to 120°C and held at the same temperature for 1 hour to complete suspension polymerization.

The obtained high molecular weight copolymer (TA-1) was separated by filtration, washed with water,
When dried and analyzed, the weight average molecular weight (Vi w
) is 320,000, and the content of parts with a molecular weight of 300,000 or more is 31.
The content of the portion with a molecular weight of 50,000 to 200,000 was 45 area %, and the content of the portion with a molecular weight of 1,000 to 30,000 was 3 area %.

2. Production of low molecular weight polymer (B) Step 22: 600 parts of toluene was put into a four-way flask, and while stirring, the inside of the flask was sufficiently replaced with nitrogen, and the toluene was heated to the boiling point (approximately 110°C). Raise the temperature to reflux.

Under this reflux, a liquid mixture consisting of 920 parts of styrene, 80 parts of n-butyl acrylate, and 90 parts of abbisisobutyronitrile was evenly dropped into the flask over 4 hours.

Furthermore, under refluxing toluene, a solution of 300 parts of toluene and 10 parts of azobisisobutyronitrile was added dropwise into the flask over 1 hour to complete the polymerization and form a solution containing a low molecular weight polymer (TA-2). ) was obtained.

This solution was dried under reduced pressure and a low molecular weight polymer (TA-3
) was obtained.

Analysis of the obtained low molecular weight polymer (TA-3) revealed that the weight average molecular weight (nw) was 8,000, the content of parts with a molecular weight of 300,000 or more was O area %, and the content of parts with a molecular weight of 50,000 to 200,000. The amount was 1 area %, and the content of the portion with a molecular weight of 1,000 to 30,000 was 90 area %.

3. Manufacture of binder In the 4-hole flask of 21, high molecular weight copolymer (TA-
1) Add 333 parts and 1334 parts of a solution (TA-2) containing a low molecular weight polymer (TA-3), and after purging the inside of the flask with nitrogen, raise the temperature and reflux the toluene. . Under this reflux, the high molecular weight copolymer (TA-1) was dissolved and then dried under reduced pressure to obtain a binder (TA-4).

When the obtained binder (TA-4) was measured by GPC and the glass transition point (Tg),
The content of parts with a molecular weight of 300,000 or more is 9% by area, and the molecular weight is 5.
The content of the part of 10,000 to 200,000 is 15% by area, and the molecular weight is 100.
The content of the 0 to 30,000 part is 60 area%, the weight average molecular weight (Mw) is 120,000, the value of the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw/1ln) is 21,' rg
was 59°C.

Moreover, regarding the obtained binder (TA-4), 150
When the dynamic viscoelasticity was measured at ℃, the absolute value of the complex viscosity at a frequency of 207 |η*(20)1 was 650 p
oise, absolute value of complex viscosity at 17 |η*(1)1
is 2600 poise, and the value of the ratio of the above absolute values |
η*(20)l/lη*(1)1 was 0.25.

(Comparative Example 2) 1. Production of high molecular weight copolymer (A) High molecular weight copolymer (TB-1) ) was obtained. The difference from the production method of Comparative Example 1 is that instead of the polymerization initiator lauroyl peroxide having a monofunctional structure,
The point is that a polymerization initiator having a bifunctional structure, 1,1-di-t-butylperoxy-3,3°5-trimethylcyclohexane, is used.

The obtained high molecular weight copolymer (TB-1) was separated by filtration, washed with water,
When dried and analyzed, the weight average molecular weight (Mw) was 850,000, the content of parts with a molecular weight of 300,000 or more was 79% by area, the content of parts with a molecular weight of 50,000 to 200,000 was 13% by area, and the molecular weight was 10.
The content of the portion between 00 and 30,000 was 0 area %.

2. Production of binder A binder (TB-4) was obtained by performing substantially the same operation as the method for producing a binder in Comparative Example 1.

When the obtained binder (TB-4) was measured by GPC and the glass transition point (T g ), the content of the portion with a molecular weight of 300,000 or more was 26% by area, and the content of the portion with a molecular weight of 50,000 to 200,000 was 26% by area. Part content is 5 area%, molecular weight 1
The content of the 000 to 30,000 portion is 60 area%, the weight average molecular weight (Mw) is 250,000, the ratio of the weight average molecular weight (R7w) to the number average molecular weight (Mn) (?1w/Mn) is 60,
Tg was 60°C.

Also, regarding the obtained binder (TB-4), 150
When measuring the dynamic viscoelasticity at ℃, it was found that the frequency was 20H.
The absolute value of the complex viscosity at z | η * (20) 1 is 3600
absolute value of complex viscosity at poise, llz |η
*(1) I is 23000 poise, and the ratio of the above absolute values |η* (20) I/|η*(1)1 is 0.1
It was 6.

(Comparative Example 3) 1. Production of high molecular weight copolymer (A) 450 parts of water and 50 parts of a 2% by weight aqueous solution of polyvinyl alcohol (PVA235 manufactured by Kuraray) were added to the glass flask of 11, and to this, A liquid mixture consisting of 750 parts of styrene, 250 parts of n-butyl acrylate, and 2 parts of di-L-butylperoxyhexavite rotilefcrate was added and stirred to form a suspension.

After the inside of the flask was sufficiently purged with nitrogen, the temperature was raised to 85°C to start polymerization. Maintaining the same temperature to continue polymerization, confirm that the conversion rate exceeded 70% after 8 hours, raise the temperature to 95 ° C., and complete suspension polymerization after 4 hours.
A high molecular weight copolymer (TC-1) was obtained.

The obtained high molecular weight copolymer (T(, -1) was separated by filtration, washed with water, dried, and analyzed. As a result, the weight average molecular weight (FZ
w ) is 560,000, and the area with a molecular weight of 300,000 or more is 61% by area.
The content of the portion with a molecular weight of 50,000 to 200,000 was 23 area %, and the content of the portion with a molecular weight of 11,000 to 30,000 was 0 area %.

2. Binder manufacturing 1! 450 parts of the above-mentioned high molecular weight copolymer (TC-1) and 550 parts of xylene were put into a stainless steel autoclave, the inside of the autoclave was sufficiently purged with nitrogen, the autoclave was sealed, and the temperature was raised to 200°C. While maintaining the temperature at 200°C, a mixed solution consisting of 420 parts of styrene, 100 parts of methyl acrylate, and 40 parts of n-butyl acrylate was evenly dropped into the autoclave over 8 hours, and the mixture was further maintained at the same temperature for 3 hours. to complete the polymerization and binder (TC
-4) was obtained.

The obtained binder (TC-4) was measured by GPC and the glass transition point (Tg).
The content of the part with a molecular weight of 300,000 or more is 27% by area, the content of the part with a molecular weight of 50,000 to 200,000 is 8% by area, and the molecular weight is 100.
The content of the 0 to 30,000 part is 50 area%, the weight average molecular weight (nw) is 330,000, the value of the ratio of weight average molecular weight (nw) to number average molecular weight (Mn) (Mw/Mn) is 55,' rg was 62°C.

Moreover, regarding the obtained binder (TC-4), 150
When the dynamic viscoelasticity was measured at ℃, the absolute value of the complex viscosity at a frequency of 207 |η*(20)1 was 4000p
oise , the absolute value of the complex viscosity at 1 Hz |η*(1
)l is 30,000 poise, and the value of the ratio of the above absolute values |η
*(20)l/lη*(1)1 was 0.13.

(Example 1) The binder of Comparative Example 2 (T
B-4) 600 parts, 330 parts of styrene, acrylic acid n-
A mixed solution consisting of 70 parts of butyl and 0.2 parts of 1,6-hexanediol diacrylate was charged.

After the inside of the flask was sufficiently purged with nitrogen, the temperature was raised while sealing with nitrogen, and polymerization was carried out at 110° C. for 2 hours.

Thereafter, the temperature was raised to 120°C, polymerization was carried out at the same temperature for 10 hours, and the temperature was further raised to 190°C in 3 hours, and polymerization was carried out at the same temperature for 2 hours.
The binder of the present invention (T
E-4) was obtained.

The obtained binder (TE-4) was measured by GPC and the glass transition point (Tg).
The content of the part with a molecular weight of 300,000 or more is 25 area%, the content of the part with a molecular weight of 50,000 to 200,000 is 5 area% per month, and the molecular weight is 10
The content of the 00 to 30,000 part is 49 area%, the weight average molecular weight (Mw) is 280,000, the value of the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn) is 63,
Tg was 59°C.

Also, regarding the obtained binder (TE-4), 150
When measuring the dynamic viscoelasticity at ℃, it was found that the frequency was 20H.
The absolute value of the complex viscosity at z | η * (20) 1 is 4400
poise , absolute value of complex viscosity at 1 Hz |η*
(1) l is 32000 poise, and the ratio of the above absolute values is |η* (20) l/lη* (1) l is 0.14
Met.

(Example 2) The binder of Comparative Example 3 (T
B-4) 800 parts, 165 parts of styrene, acrylic acid n-
A mixture consisting of 35 parts of butyl was charged.

After the inside of the flask was sufficiently purged with nitrogen, the temperature was raised while sealing with nitrogen, and polymerization was carried out at 130° C. for 4 hours.

Thereafter, the temperature was raised to 190°C in 3 hours and kept at the same temperature for 2 hours to complete polymerization, and the binder of the present invention (TF
-4) was obtained.

The obtained binder (TF-4) was measured by GPC and the glass transition point (Tg).
The content of the part with a molecular weight of 300,000 or more is 23 area%, the content of the part with a molecular weight of 50,000 to 200,000 is 23 area%, and the molecular weight is 10
The content of the 00 to 30,000 part is 48 area%, the weight average molecular weight (Mw) is 260,000, the value of the ratio of weight average molecular weight (Mw) to number average molecular weight (!In) is 43, '
rg was 58°C.

Also, regarding the obtained binder (TF-4), 150
When measuring the dynamic viscoelasticity at ℃, it was found that the frequency was 20H.
The absolute value of the complex viscosity at z | η * (20) 1 is 2600
poise , absolute value of complex viscosity at 1 Hz |η*
(1) I is 15000 poise, and the ratio of the above absolute values lη* (20) l/lη* (1) 1 is 0.17
Met.

(Example 3) 400 parts of the high molecular weight copolymer (TA-3) of Comparative Example 1, 480 parts of styrene, 120 parts of n-butyl acrylate, 0.6 parts of divinylbenzene, and A mixture consisting of 0.3 parts of 2.2-bis-(4,4-di-t-butylperoxycyclohexyl)propane was charged.

After the inside of the flask was sufficiently purged with nitrogen, the temperature was raised to 95°C, polymerization was carried out at the same temperature for 8 hours, and the temperature was further raised to 120°C, and polymerization was carried out for 2 hours.

When I sampled this and analyzed it, I found that the conversion rate was 7.
5%, the content of parts with a molecular weight of 300,000 or more is 60% by area,
The content of the portion with a molecular weight of 50,000 to 200,000 was 10 area %, and the content of the portion with a molecular weight of 1,000 to 30,000 was 0 area %.

Furthermore, in the flask, di-t-butyl peroxide 0
．． 6 parts of the mixture was added, the temperature was raised to 180°C over 3 hours, and the temperature was maintained for 2 hours to complete the polymerization, thereby obtaining the binder (TG-4) of the present invention.

When the obtained binder (T(, -4) was measured by GPC and the glass transition point (Tg) was measured, the content of the portion with a molecular weight of 300,000 or more was 26% by area, and the molecular weight was 50,000 to 200,000. The content of the part is 15 area%, the molecular weight is 1
The content of the part of 000 to 30,000 is 50 area%, the weight average molecular weight (Faw) is 280,000, the weight average molecular weight (MW)
and number average molecular weight (Mn) (Mw/Mn) is 62
, Tg was 60°C.

Also, regarding the obtained binder (TE-4), 150
When the dynamic viscoelasticity was measured at °C, the absolute value of the complex viscosity at a frequency of 207 |η*(20)l was 5000
absolute value of complex viscosity at 177*(1
)l was 36000 poise, and the ratio of the above absolute values |η*(20)l/lη*(1)1 was 0.14.

(Usage Examples I to ■ and Comparative Use Examples ■ to ■) 88 parts each of the binder of the present invention of Examples 1 to 3 and the binder of Comparative Examples 1 to 3 were added to carbon blank (MA1 manufactured by Mitsubishi Kasei ■).
After uniformly mixing 7 parts of 00), 3 parts of low molecular weight polypropylene (Viscol 550 P manufactured by Sanyo Chemical Industries, Ltd.), and 2 parts of charge adjustment side (Spiron Black TRH manufactured by Hodogaya Chemical Company Ltd.), this was heated to an internal temperature. The mixture was kneaded using a twin-screw extruder at 150°C. After cooling this kneaded material, it was finely pulverized with a jet pulverizer, classified with a dispersion separator, and the average particle size was 1.
2μ toners (I to ■) were obtained.

(Test Example 1) A test material was prepared by uniformly mixing 97 parts of a ferrite carrier (EFV200/300 manufactured by Nippon Seifun ■) with 3 parts of each of the toners (I to ■).

In addition, a commercially available copying machine (BD-7720 manufactured by Toshiba Corporation) was modified to provide a fixing device with variable fixing speed, and a fixing test of the above test materials was conducted using this fixing device.

Furthermore, at a copying speed of 40 A4 sheets per minute,
A fixing test was conducted on 3,000 sheets, and the presence or absence of toner scattering was investigated.

The test results are shown in Table 1.

Table 1 Test results *Number of sheets of A4 paper fixed per 11 minutes.

*2 The black solid area with an image density of 1.2 was subjected to the Jakushin style fastness test (
The temperature of the heat roll when a copy was obtained in which 70% or more of the image density remained in the black part after rubbing by rubbing it back and forth 5 times with paper (the marking part was made of paper).

*3 Heat roll temperature when toner becomes really off-cented.

As shown in Table 1, toners (I to ■) using binders (TD-4) to (TF-4) of Examples 1 to 3 of the present invention
are the binders (TA-4) to (TA-4) of Comparative Examples 1 to 3.
MF and H2 compared to toners (■ to ■) using 4)
It has a wide temperature range between O and has low dependence on copying speed, and has thermal properties preferable as a toner.

(Effects of the Invention) The binder of the present invention is a binder made of a polymer with a wide molecular weight distribution that has favorable properties in terms of HO and MP (low MF and high HO), and also It is effective as a binder for electrophotographic toners that has little dependence and can support a wide range of copying speeds.

Furthermore, the present invention is effective as an electrophotographic toner binder that has excellent running properties during copying, since coloring materials such as carbon bra, 7-liquid, and additives such as charge control agents are uniformly dispersed during toner production. .

Patent applicant: Sanyo Chemical Industries, Ltd.

Claims (2)

[Claims] (1) (a) I, a high molecular weight copolymer (A) containing a portion with a molecular weight of 300,000 or more in the molecular weight distribution, and II, a low molecular weight copolymer (A) containing a portion with a molecular weight of 1,000 to 30,000 in the molecular weight distribution B) and III, an intermediate molecular weight copolymer (C) containing a portion with a molecular weight of 50,000 to 200,000 in the molecular weight distribution, with a weight average molecular weight of 200,000 to 1,000,000, and a weight average molecular weight of and number average molecular weight is 40
~100, comprising (b) a high molecular weight copolymer (A) and an intermediate molecular weight polymer (C
) are two or more types of monomers, respectively, I, styrene or styrene substituted product, and II, acrylic esters and/or methacrylic esters, and (c) low molecular weight polymer (B ), the monomers constituting I
, styrene or a styrene-substituted product, II, styrene or a styrene-substituted product, and two or more monomers of acrylic esters and/or methacrylic esters, (d) high molecular weight copolymer (A) is obtained by copolymerizing monomers in the presence of a polyfunctional polymerization initiator (D), and (e) the polyfunctional polymerization initiator (D) has I, within one molecule. II. A polyfunctional polymerization initiator having one or more peroxide groups and one or more polymerizable unsaturated groups in one molecule. and (f) the intermediate molecular weight copolymer (C) is monopolized in the presence of the high molecular weight copolymer (A) and the low molecular weight polymer (B) substantially without using a solvent. 1. A toner binder for electrophotography, characterized in that the toner binder is made of a copolymerized polymer. (2) Absolute value of complex viscosity at a frequency of 20 Hz in dynamic viscoelastic properties in a molten state at 150°C |
η*(20) | 1000~15000poise, 1
The absolute value of the complex viscosity in Hz |η*(1)| is 50
00 to 60,000 poise, and the ratio of the absolute values |η*(20)|/|η*(1)| is 0.20 or less. toner binder.