JPH10319635A - Resin composition for toner and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. for a toner excellent in fixability, anti- offsetting property and preservability by using two vinyl copolymers. SOLUTION: This resin compsn. is made of a vinyl copolymer (1) having >=68 deg.C Ttan δ and consisting of a vinyl copolymer (A) having the mol.wt. peak in the mol.wt. range of 4,000-20,000 in the mol.wt. distribution by GPC and a vinyl copolymer (B) having the mol.wt. peak in a mol.wt. range of >=300,000. The vinyl copolymer B has a glass transition temp. (y) ( deg.C) satisfying the formula 0<=y<=(-1/2)x+125 and the weight percentage (z) (>0 wt.%) of the vinyl copolymer B in the vinyl copolymer 1 satisfies the formula (-1/10)x+24<=z<=(-17/100)x+48.5. In the formulae, (x) is mol.wt. (×10<4> ) corresponding to the mol.wt. peak of the vinyl copolymer B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for toner used in electrophotography and the like and an electrophotographic toner therefor. The present invention relates to a resin composition for a toner used in an electrophotographic apparatus or the like employing a dry development method, and a toner using the same.

[0002]

2. Description of the Related Art In electrophotography and the like, a dry developing method is often used as a method for developing an electrostatic image. In this method, the toner is usually made of iron powder called a carrier,
After being charged by friction with glass beads, etc., it adheres to the electrostatic latent image on the photoreceptor by electrostatic attraction to form an image, and is then transferred to the paper in contact with the rotating photoreceptor, and is heated by a hot roll, etc. The image is fixed on paper and becomes a permanent visible image.

As a fixing method using a heat roll or the like, a toner latent image is passed through a surface of a heating roller formed of a material having a releasable property with respect to toner while being in pressure contact with a sheet to be fixed. The heating roller method used is often used.

By the way, in this heating roller method,
In order to improve economical efficiency such as power consumption and to increase copying speed, a resin composition for toner having excellent fixability even at a low heating temperature is desired.

In the heating roller method, the surface of the heating roller and the toner come into contact with each other in a molten state and under a pressurized condition.
A so-called offset phenomenon in which a part of the toner adheres to the surface of the fixing roller and is re-transferred to the sheet is likely to occur. As a countermeasure against this offset phenomenon, a method of applying silicone oil or the like to the surface of the fixing roller is known, but in this case, there is a problem that the apparatus becomes complicated. Therefore, development of a resin composition for toner having excellent offset resistance is also desired.

[0006] Further, in order to prevent the toner from coalescing in the developing device, a resin composition for toner having excellent storability has been demanded. Therefore, these three performances:
A toner and a resin composition for toner which are excellent in all of low-temperature fixability, offset resistance and storage stability are desired.

[0007] Japanese Patent Application Laid-Open No. 4-204457 discloses a resin comprising at least one thermoplastic resin selected from styrene resins, polyester resins and copolymers thereof and having a molecular weight of 30,000 or more. Disclosed are toners in which the glass transition point when divided into those smaller than the above is limited to improve the fixing property and the storage stability at low temperatures.

Conventionally, it is known that the glass transition point of a resin is closely related to the fixing temperature and the storage stability.
To lower the fixing temperature, it is necessary to lower the glass transition point of the resin, but if the glass transition point is too low,
Preservability deteriorates. In the above-described technology, the glass transition point of the low molecular weight component and the high molecular weight component having a molecular weight of 30,000 or more is limited to improve the fixing property and the storage stability at low temperatures, but there is a problem with the offset resistance. There was a case.

[0009] Japanese Patent Application Laid-Open No. Hei 8-101531 discloses that the lowest molecular weight range is limited to 4000 to 10,000,
There is disclosed a toner in which the storage stability is improved by making less than 5% by weight of components of 000 or less in the total composition. According to this technique, the mixing ratio of a low-molecular-weight resin is reduced and the preservability is improved, but the fixability at low temperatures, the preservability and the offset resistance are not balanced.

[0010]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a resin composition for a toner which is excellent in fixability, offset resistance and storage stability, and a toner using the same.

[0011]

According to the present invention, a vinyl copolymer A having a molecular weight peak of 4000 to 20,000 in molecular weight distribution by gel permeation chromatography (GPC) and a molecular weight of 300,000 or more are provided. And at least two molecular weight peaks including a molecular weight peak derived from the vinyl copolymer A and a molecular weight peak derived from the vinyl copolymer B in the molecular weight distribution. A resin composition for a toner comprising a vinyl copolymer (1) having a T _tan δ of 68 ° C. or higher, wherein the vinyl copolymer B has a molecular weight and a glass transition corresponding to a molecular weight peak. The point satisfies the following relationship, and the molecular weight corresponding to the molecular weight peak and the weight ratio of the vinyl copolymer (1) ( %) Is a resin composition for toner satisfying the following relationship. 0 ≦ y ≦ (− ／) x + 125 [wherein, y represents a glass transition point (° C.)]. x represents a molecular weight (× 10 ⁴ ) corresponding to the molecular weight peak of the vinyl copolymer B. ] (-1/10) x + 24≤z≤ (-17/100) x
+48.5 and z> 0 wherein x is the same as above. z represents the weight ratio (%) of the vinyl copolymer B in the vinyl copolymer (1). Hereinafter, the present invention will be described in detail.

The resin composition for a toner of the present invention comprises a vinyl copolymer (1) comprising a vinyl copolymer A and a vinyl copolymer B. The vinyl copolymer A is
It has a molecular weight peak at a molecular weight of 4000 to 20,000. The molecular weight peak is in a molecular weight distribution measured by gel permeation chromatography (GPC).

When the molecular weight peak of the vinyl copolymer A is less than 4,000, the storage stability of the obtained resin composition deteriorates, and when it exceeds 20,000, good fixability cannot be obtained. Limited to range.

The vinyl copolymer A preferably contains a styrene monomer and a (meth) acrylate monomer as constituent units.

The styrene monomer is not particularly restricted but includes, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethyl styrene,
pn-butylstyrene, pt-butylstyrene, p
-N-hexylstyrene, pn-octylstyrene,
pn-dodecylstyrene, p-methoxystyrene, p
-Phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene and the like.

The (meth) acrylate monomer is not particularly restricted but includes, for example, methyl acrylate,
Ethyl acrylate, propyl acrylate, n-acrylate
-Butyl, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacryl Alkyl esters of (meth) acrylic acid such as n-octyl acid, dodecyl methacrylate, stearyl methacrylate;
2-chloroethyl acrylate, phenyl acrylate, α
-Methyl chloroacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, glycidyl acrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-methacrylic acid Examples include hydroxyethyl, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate, methacryloxyethyl phosphate, and the like. Among them, 2-ethylhexyl acrylate, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate and the like are preferable.

The vinyl copolymer A may contain another vinyl monomer. The other vinyl monomers are not particularly limited, and include, for example, (meth) acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, and α-alkyl or β-alkyl derivatives thereof; Unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid or monoester derivatives or diester derivatives thereof; monoacryloyloxyethyl succinate, monomethacryloyloxyethyl succinate, acrylonitrile, methacrylonitrile, acrylamide, etc. Is mentioned.

In the present invention, the above-mentioned vinyl copolymer A
May be obtained by copolymerizing a crosslinking agent. The crosslinking agent is not particularly limited, and examples thereof include divinylbenzene, ethylene glycol di (meth) acrylate,
3-butylene glycol di (meth) acrylate, 1,
4-butanediol di (meth) acrylate, 1,5-
Pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, pentaethylene glycol di ( Meth) acrylate, polyethylene glycol # 2
00, # 400, and # 600 di (meth) acrylate, dipropylene glycol di (meth) acrylate,
Bifunctional ones such as polypropylene glycol di (meth) acrylate; pentaerythritol tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, oligo Polyfunctional such as ester (meth) acrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, and diarylchlorendate And the like.

The vinyl copolymer A can be synthesized by, for example, suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization and the like. The polymerization initiator used in the synthesis of the vinyl copolymer A is not particularly limited, and examples thereof include a peroxide-based polymerization initiator and an azo-based polymerization initiator.

The above-mentioned peroxide-based polymerization initiator is not particularly restricted but includes, for example, ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl acetoacetate peroxide and acetylacetone peroxide; 1,1-bis ( t-
Peroxyketals such as butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate; t-butyl hydroperoxide, cumene hydroperoxide; Hydroperoxides such as diisopropylbenzene hydroperoxide and p-menthane hydroperoxide; di-t-butyl peroxide, t
Dialkyl peroxides such as -butylcumyl peroxide and dicumyl peroxide; diacyl peroxides such as acetyl peroxide, isobutyl peroxide, octanoyl peroxide, benzoyl peroxide, and 2,4-dichlorobenzoyl peroxide; diisopropyl Peroxydicarbonates such as peroxydicarbonate, di-n-propylperoxydicarbonate, dimethoxyisopropylperoxydicarbonate and diallylperoxydicarbonate; t-butyl peracetate, t-butyl peroxypivalate, t Peroxyesters such as -butylperoxybenzoate and cumylperoxyoctanoate; acetylcyclohexylsulfonyl peroxide, di-t-butylperoxide Carboxymethyl hexahydroterephthalate and the like.

The azo polymerization initiator is not particularly restricted but includes, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile,
Examples thereof include 2,2'-azobis-2,4-dimethylvaleronitrile and dimethyl-2,2'-azobisisobutyrate.

The vinyl copolymer B used in the present invention
Has a molecular weight peak at a molecular weight of 300,000 or more. When the molecular weight peak is less than 300,000, the effect of improving the anti-offset property is small, so that it is limited to the above range.

The vinyl copolymer B preferably contains a styrene monomer and a (meth) acrylate monomer as constituent units. The styrenic monomer is not particularly limited, and examples thereof include those exemplified in the above-mentioned vinyl copolymer A. The (meth) acrylic acid ester-based monomer is not particularly limited, and includes, for example, those exemplified for the vinyl-based copolymer A. The vinyl copolymer B may contain other vinyl monomers. The other vinyl monomer is not particularly limited, and examples thereof include those exemplified in the vinyl copolymer A.

In the present invention, the above vinyl copolymer B
May be obtained by copolymerizing a crosslinking agent. The crosslinking agent is not particularly limited, and includes, for example, those exemplified in the above vinyl copolymer A.

The vinyl copolymer B can be synthesized by, for example, suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization, or the like. The polymerization initiator used in the synthesis of the vinyl copolymer B is not particularly limited, and examples thereof include those exemplified for the vinyl copolymer A.

In the present invention, the above-mentioned vinyl copolymer B
Is the molecular weight corresponding to the molecular weight peak and the glass transition point (T
g) satisfies the following relationship. 0 ≦ y ≦ (− ／) x + 125 In the formula, y represents Tg (° C.). x is a molecular weight (× 10 ⁴ ) corresponding to the molecular weight peak of the vinyl copolymer B.
Represents The Tg is measured according to JIS K7121.

If the above Tg is lower than 0 ° C., the resulting resin composition may have reduced offset resistance. When the Tg does not satisfy the above relationship, the molecular weight of the vinyl copolymer B becomes too large, and the fixability of the obtained resin composition is reduced.

When the molecular weight x (× 10 ⁴ ) corresponding to the molecular weight peak of the vinyl copolymer B satisfies 30 ≦ x ≦ 186, the molecular weight corresponding to the molecular weight peak of the vinyl copolymer B is determined. The glass transition point (Tg) preferably satisfies the relationship of 0 ≦ y ≦ (−2/9) x + 220/3 among the above x and y satisfying the above relationship. Wherein x and y are the same as above.

The vinyl copolymer B is one in which the molecular weight corresponding to the molecular weight peak and the weight ratio z in the vinyl copolymer (1) satisfy the following. (-1/10) x + 24≤z≤ (-17/100) x
+48.5 and z> 0 where x is the same as above. If the molecular weight corresponding to the molecular weight peak and the weight ratio (%) z do not satisfy the above relationship, the weight ratio of the vinyl copolymer B having a large molecular weight peak becomes too large,
Since the fixability of the obtained resin composition is reduced, it is limited to the above range. When the vinyl copolymer B has a plurality of molecular weight peaks, z means the weight ratio of the molecular weight peak portion at the largest molecular weight.

Since the above-mentioned vinyl copolymer B satisfies the above-mentioned relationship, the molecular weight increases even if the Tg decreases or the weight ratio decreases.
There is no risk of deteriorating the offset resistance.

In the present invention, the above-mentioned vinyl copolymer A
The method for blending the vinyl copolymer B with the vinyl copolymer B is not particularly limited. For example, a method in which the vinyl copolymer A and the vinyl copolymer B are dissolved in a solvent and mixed;
A method of kneading the vinyl copolymer A and the vinyl copolymer B with a kneader; a method of solution-polymerizing the vinyl copolymer A in the presence of the vinyl copolymer B; .

In the molecular weight distribution of the vinyl copolymer (1) comprising the vinyl copolymer A and the vinyl copolymer B, the molecular weight peak derived from the vinyl copolymer A and the It has at least two molecular weight peaks including a molecular weight peak derived from the vinyl copolymer B. Since the resin composition for a toner of the present invention has the above-mentioned at least two molecular weight peaks, the fixability at low temperatures and the anti-offset property can be improved in a good balance.

The vinyl copolymer (1) has a T _tan δ
Is 68 ° C. or higher. The T _tan δ is a temperature at which _tan δ by dynamic viscoelasticity measurement reaches a maximum value. When the T _{ta n} [delta] is less than 68 ° C., since storage stability of the resin composition is lowered, the above range is critical. Preferably, 7
0 ° C. or higher.

The resin composition for a toner of the present invention comprises the above-mentioned vinyl copolymer (1). In the resin composition for a toner of the present invention, vinyl acetate, vinyl chloride, or the like is added to the vinyl copolymer A and / or the vinyl copolymer B as long as the object of the present invention can be achieved. It may be used after copolymerization, and polymers such as vinyl acetate and vinyl chloride may be mixed. In addition, an ethylene-based olefin polymer such as polyethylene or polypropylene accounts for 1% of the total composition.
It may be mixed at 5% by weight or less, and among polyester resins, epoxy resins, urethane resins and vinyl resins, those having a weight average molecular weight in GPC of 30,000 to 300,000 may be mixed. Aromatic amide, bisaliphatic amide, metal soap, paraffin and the like may be mixed.

The toner of the present invention uses the above resin composition for toner. The toner of the present invention is produced by adding a colorant, a charge control agent and the like to the resin composition for a toner, and further, if necessary, dispersing and mixing a magnetic powder and the like, followed by hot melting, kneading and pulverization. .

The coloring agent is not particularly limited, and examples thereof include carbon black, aniline black, phthalocyanine blue, quinoline yellow, lamp black, rhodamine-B, quinacridone and the like. The amount of the colorant is usually 1 to 10 parts by weight based on 100 parts by weight of the resin composition for a toner.

The charge control agents include those for positive charging and those for negative charging. Examples of the positive charge control agent include a nigrosine dye, an ammonium salt, a pyridinium salt, and azine. Examples of the negative charge control agent include a chromium complex and an iron complex.
The amount of the charge control agent is usually 0.1 to 10 parts by weight based on 100 parts by weight of the resin composition for a toner.

As described above, the resin composition for a toner according to the present invention comprises a vinyl copolymer A having a molecular weight peak of 4000 to 20,000 and a vinyl copolymer B having a molecular weight peak of 300,000 or more. Having at least two molecular weight peaks in the molecular weight distribution, including a molecular weight peak derived from the vinyl copolymer A and a molecular weight peak derived from the vinyl copolymer B, and T _tan δ
Is a vinyl copolymer (1) having a temperature of 68 ° C. or higher, and the vinyl copolymer B has a molecular weight corresponding to a molecular weight peak and Tg satisfying the above relationship, and Since the molecular weight corresponding to the molecular weight peak and the weight ratio in the vinyl copolymer (1) satisfy the above relationship, the fixing property, the offset resistance,
It has excellent storage stability. Further, the toner using the resin composition for toner has characteristics excellent in fixing property, anti-offset property and storage stability.

[0039]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Preparation of resin composition 70 parts by weight of styrene, 30 parts by weight of n-butyl acrylate, 0.005 parts by weight of divinylbenzene, and 2.2 parts by weight
0.15 parts by weight of -bis (4,4-di-t-butylperoxycyclohexyl) propane was synthesized by suspension mixing,
A high molecular weight vinyl copolymer a was obtained. The resulting high molecular weight vinyl copolymer a ₁ 25 parts by weight of toluene 100 parts by weight was charged to the flask to dissolve. After replacing the inside of the flask with nitrogen gas, the flask was heated to the boiling point of toluene.
While stirring with the reflux of toluene, 85 parts by weight of styrene, 15 parts by weight of n-butyl acrylate, and
A mixture of 4.5 parts by weight of benzoyl peroxide (polymerization initiator) was added dropwise over 3 hours to carry out coexisting solution polymerization. After completion of the dropwise addition, stirring under reflux toluene, over a period of 1 hour perform ripening, the maximum value of molecular weight obtained by polymerizing a low molecular weight vinyl copolymer b ₁ of 10,000. Thereafter, while gradually increasing the temperature in the flask to 180 ° C., the toluene was removed under reduced pressure to obtain a resin composition I for toner.

[0041] Incidentally, the obtained resin composition for toner I, molecular weight, Tg, and calculate the weight ratio of the high molecular weight vinyl copolymer a _1. Further, T _tan δ of the obtained resin composition I for toner was measured.

Measurement of molecular weight Resin composition for toner I so that the sample concentration becomes 0.2%
Was dissolved in tetrahydrofuran over 2 hours, and 0.4
100 μl of solution passed through a 5 micron filter
Was supplied to a column (two KF-80M and KF-802.5) having a column temperature of 40 ° C., and separated at a flow rate of 1 ml / min using tetrahydrofuran as a solvent, and the molecular weight distribution was measured. I asked. The molecular weight is
It was determined in terms of styrene. The results are shown in Table 1.

Measurement of Tg Measured according to JIS K 7121. Table 1 shows the results
It was shown to. Measurement of T _tan δ RMS manufactured by Rheometric Scientific FE
Jig: 7.8 mm parallel disk, strain amplitude: 0.1%, angular frequency: 1 rad / sec. The temperature was measured at a heating rate of 2 ° C./min. The results are shown in Table 1.

Production of Toner Using the obtained resin composition for toner I, the following composition was used: 100 parts by weight of resin composition I for toner 1.5 parts by weight of Spiron Black TRH (manufactured by Hodogaya Chemical Industry Co., Ltd.) 6.5 parts by weight of carbon black (MA-100, manufactured by Mitsubishi Chemical Corporation) are mixed, melt-kneaded at 150 ° C., and then pulverized by a jet mill. Silica (R972, manufactured by Nippon Aerosil Co., Ltd.)
Toner I was obtained by adding 0.3% by weight.

Example 2 65 parts by weight of styrene, 35 parts by weight of n-butyl acrylate, and 1,1-di-t-butylperoxy-3,
3,5-trimethyl cyclohexane 0.1 parts by weight synthesized in a suspension polymerization to obtain a high molecular weight vinyl copolymer a _2. 35 parts by weight of the obtained high molecular weight vinyl copolymer a ₂ and 100 parts by weight of toluene were charged into a flask and dissolved. After replacing the inside of the flask with nitrogen gas, the flask was heated to the boiling point of toluene. 86 parts by weight of styrene, 14 parts by weight of n-butyl acrylate, and benzoyl peroxide (polymerization initiator) with stirring while refluxing toluene occurs.
4.5 parts by weight of the mixed solution was added dropwise over 3 hours to perform coexisting solution polymerization. After completion of the dropwise addition, the mixture was aged for 1 hour while stirring under reflux of toluene, and the maximum value of the molecular weight was 1
Thousands of low molecular weight vinyl copolymer b ₂ was polymerized. Thereafter, while gradually raising the temperature in the flask to 180 ° C., toluene was removed under reduced pressure to obtain a resin composition II for toner. A toner II was obtained in the same manner as in Example 1 except that the resin composition II for a toner was used.

The obtained resin composition II for toner was subjected to the same procedures as in Example 1 to determine the molecular weight, Tg and T _tan.
measuring the [delta], it was calculated weight ratio of high molecular weight vinyl copolymer a _2. The results are shown in Table 1.

Example 3 40 parts by weight of toluene were charged into a flask, the atmosphere in the flask was replaced with nitrogen gas, and the flask was heated to the boiling point of toluene.
While stirring with refluxing toluene, 86 parts by weight of styrene, 14 parts by weight of n-butyl acrylate, and
A mixture of 6 parts by weight of benzoyl peroxide (polymerization initiator) was added to 3 parts.
The solution was dropped over time to perform solution polymerization. After completion of the dropwise addition, stirring under reflux toluene, over a period of 1 hour perform ripening, the maximum value of molecular weight obtained by polymerizing a low molecular weight vinyl copolymer b ₃ of 8,000. Thereafter, a high molecular weight vinyl copolymer a ₁ 20 parts by weight of toluene 100 parts by weight was added to the flask gradually raised the temperature of the flask to 180 ° C. After mixing for 2 hours at the boiling point of toluene, vacuum The solvent was removed from the toluene to obtain a toner resin composition III. A toner III was obtained in the same manner as in Example 1, except that the resin composition III for a toner was used.

Incidentally, the obtained resin composition for toner III
For, in the same manner as in Example 1, to calculate the weight ratio of the high molecular weight vinyl copolymer a _1, to measure the T _tan [delta].
The results are shown in Table 1.

Comparative Example 1 Comparative toner resin compositions IV and IV were obtained in the same manner as in Example 1, except that 4.5 parts by weight of benzoyl peroxide was changed to 12 parts by weight. The molecular weight and T _tan δ of the obtained toner resin composition IV were measured in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 Comparative resin compositions V and V for toner were obtained in the same manner as in Example 1 except that 20 parts by weight of the high molecular weight vinyl copolymer a ₁ was changed to 40 parts by weight. Was. Incidentally, the obtained resin composition for toner V, in the same manner as in Example 1, to calculate the weight ratio of the high molecular weight vinyl copolymer a _1, to measure the T _tan [delta]. The results are shown in Table 1.

Comparative Example 3 Comparative toner resin compositions VI and VI were obtained in the same manner as in Example 1 except that 20 parts by weight of the high molecular weight vinyl copolymer a ₁ was changed to 8 parts by weight. Was. Incidentally, the obtained resin composition for toner VI, in the same manner as in Example 1, to calculate the weight ratio of the high molecular weight vinyl copolymer a _1, to measure the T _tan [delta]. The results are shown in Table 1.

Comparative Example 4 85 parts by weight of styrene and 15 parts by weight of n-butyl acrylate
Parts, 0.005 parts by weight of divinylbenzene and 2.2 parts by weight
-Bis (4,4-di-t-butylperoxycyclohexene
0.15 parts by weight of sil) propane is synthesized by suspension polymerization.
High molecular weight vinyl copolymer a_ThreeI got High molecular weight vinyl
System copolymer a₁Is a high molecular weight vinyl copolymer a_Threechange to
Except that the toner for comparison was the same as in Example 1.
And a toner composition VII. In addition,
About the obtained resin composition VII for toners, Example 1
Measure the molecular weight and Tg in the same manner as in
System copolymer a_ThreeIs calculated, and T _tanMeasure δ
Was. The results are shown in Table 1.

Comparative Example 5 25 parts by weight of a high molecular weight vinyl copolymer a ₁ and toluene 1
And 100 parts by weight were put into a flask and dissolved. After replacing the inside of the flask with nitrogen gas, the flask was heated to the boiling point of toluene. While stirring with the reflux of toluene,
A mixture of 76 parts by weight of styrene, 24 parts by weight of n-butyl acrylate, and 4.5 parts by weight of benzoyl peroxide (polymerization initiator) was added dropwise over 3 hours to carry out coexisting solution polymerization. After completion of the dropwise addition, while stirring under reflux of toluene, 1
Perform aging over time, the maximum value of molecular weight obtained by polymerizing a low molecular weight vinyl copolymer b ₄ 10,000. Thereafter, while gradually raising the temperature in the flask to 180 ° C., the solvent was removed from the toluene under reduced pressure, and the resin composition VI for comparison toner was used.
II and Toner VIII were obtained. Incidentally, the obtained resin composition for toner VIII, in the same manner as in Example 1, to calculate the weight ratio of the high molecular weight vinyl copolymer a _1, to measure the T _tan [delta]. The results are shown in Table 1.

[0054]

[Table 1]

Test Method (1) Fixing Property The toners obtained in Examples 1 to 3 and Comparative Examples 1 to 5 (6.
5 parts by weight) of an iron powder carrier (9
(3.5 parts by weight) to prepare a developer, and a plurality of unfixed images were prepared using this developer. Next, the surface temperature of the heat fixing roll was set to 150 ° C. and 170 ° C., and the toner image of the transfer paper on which the unfixed image was formed was fixed.
The electrophotographic copying machine used was a modified Toshiba Leo Dry 5540. The formed fixed image was rubbed with a cotton pad, and the fixing strength was calculated according to the following equation, which was used as an index of the fixing property. For image density, a reflection densitometer RD-914 manufactured by Macbeth was used. The results are shown in Table 2. Fixing strength (%) = (image density of fixed image after rubbing / image density of fixed image before rubbing) × 100

(2) Offset Resistance The surface temperature of the heat fixing roll was changed stepwise to obtain a copy in which the toner image of the transfer paper having the unfixed image was fixed at each surface temperature. At this time, observation was made as to whether or not toner smearing occurred in the blank portion, and a temperature region where no smearing occurred was defined as a non-offset temperature region. The difference between the maximum value and the minimum value in the non-offset temperature region was defined as the non-offset temperature width. The results are shown in Table 2. In Table 2, ↑
Indicates that the temperature was higher than the measurement temperature.

(3) Storage Property Each of 20 g of each of the toners I to VIII was filled in a 150 cc bottle and left in a constant temperature bath at 50 ° C. for 48 hours. Table 2 shows the obtained results.

[0058]

[Table 2]

From Table 2, it was found that the toners of Examples 1 to 3 were excellent in all of the fixing property, the anti-offset property and the storage property. In contrast, in the toners of Comparative Examples 1 to 5,
Some of the properties of one or two of the fixing property, the anti-offset property and the storability are excellent, but not all properties are excellent, and the three properties are not balanced. Did not.

[0060]

According to the present invention, which has the above-mentioned constitution, it is possible to provide a toner resin composition and toner having excellent fixability, anti-offset property and storage stability. It can be suitably used for devices and the like.

Claims (2)

[Claims] 1. A molecular weight distribution of 400 by gel permeation chromatography (GPC).
Vinyl copolymer A having a molecular weight peak at 0 to 20,000
And a vinyl copolymer B having a molecular weight peak of 300,000 or more, and a molecular weight peak derived from the vinyl copolymer A and a molecular weight derived from the vinyl copolymer B in the molecular weight distribution. A resin composition for a toner comprising a vinyl copolymer (1) having at least two molecular weight peaks including a peak and having a T _tan δ of 68 ° C. or higher, wherein the vinyl copolymer B has a molecular weight of The molecular weight corresponding to the peak and the glass transition point satisfy the following relationship, and the molecular weight corresponding to the molecular weight peak and the weight ratio (%) in the vinyl copolymer (1) are in the following relationship. A resin composition for a toner characterized by satisfying the following. 0 ≦ y ≦ (− ／) x + 125 [wherein, y represents a glass transition point (° C.)]. x represents a molecular weight (× 10 ⁴ ) corresponding to the molecular weight peak of the vinyl copolymer B. ] (-1/10) x + 24≤z≤ (-17/100) x
+48.5 and z> 0 wherein x is the same as above. z represents the weight ratio (%) of the vinyl copolymer B in the vinyl copolymer (1). ] 2. A toner comprising the resin composition for toner according to claim 1.