JP3231248B2 - Resin composition for toner and toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition for a toner and a toner using the same.

[0002]

2. Description of the Related Art Conventionally, a heating roller method has been generally used as a method for fixing toner in a dry developing method. However, it is intended to improve economic efficiency by saving power consumption and to increase copying speed. There is a need for a toner that can be fixed at a low temperature. Therefore, it has been practiced to add a crystalline compound having a low melting point to a toner composition to enable fixing at a lower temperature. However, a crystalline compound having a low melting point has a problem in that bleeding occurs due to its low viscosity, which adversely affects the storage stability of the toner.

In order to solve the above-mentioned storability of the toner, for example, JP-A-6-295097 discloses that a vinyl copolymer and a polyolefin are contained as a binder resin, and a polyolefin and a vinyl polymer are used as compatibilizers. A method using a graft polymer is disclosed. However, in this method, since the graft portion is randomly incorporated into the binder resin, there is a problem that many side chains are required to obtain the effect.

Further, in order to solve the storability of toner, for example, Japanese Patent Application Laid-Open No. 7-64323 and
JP-A-323664 discloses a method of chemically grafting or finely crosslinking a low-melting crystalline compound.
However, in these systems, since the crystalline compound having a low melting point is chemically bonded to the binder resin, there is a problem that the Tg of the binder resin is lowered and the storage stability of the toner is deteriorated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a resin composition for toner having excellent storability without impairing low-temperature fixability and offset resistance. And a toner using the same.

[0006]

Means for Solving the Problems The resin composition for toner of the present invention comprises a vinyl copolymer having a styrene monomer and a (meth) acrylate monomer as constituent units, and a compound represented by the general formula: A resin composition for a toner comprising, as a main component, an acid amide compound represented by R-CONH ₂ (wherein, R represents an alkyl group having 14 or more carbon atoms). Weight average molecular weight (Mw) = low molecular weight polymer component of 3,000 to 50,000 and weight average molecular weight (Mw) = 100,000 to 500
And a monomer having a hydroxyl group and / or a nitrogen-containing group in an amount of 1 to 30% by weight, wherein the acid amide compound is contained in the resin composition in an amount of 1 to 3% by weight.
It is characterized by containing 0% by weight.

The resin composition for a toner according to the present invention comprises a vinyl copolymer and a compound represented by the general formula R-CONH ₂ (where R represents 1 carbon atom).
Acid amide compound represented by 4 or more alkyl groups) as a main component, and the vinyl copolymer comprises a low molecular weight polymer component and a high molecular weight polymer component, and has a hydroxyl group and / or
Or, it contains a monomer having a nitrogen-containing group.

When the weight-average molecular weight (Mw) of the low-molecular-weight polymer component decreases, the glass transition point (Tg) of the resin composition for toner decreases and storage stability is impaired. 3000 ~
Limited to 50,000.

When the weight average molecular weight (Mw) of the high molecular weight polymer component decreases, the melt viscosity of the resin composition for a toner decreases and the offset resistance decreases. When the weight average molecular weight (Mw) increases, the low-temperature fixability of the resin composition decreases. 100,000-50
Limited to 100,000.

[0010] The vinyl copolymer has a styrene monomer and a (meth) acrylate monomer as constituent units.

As the styrene monomer, for example,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-
Dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chlorostyrene, 3,4-dichlorostyrene and the like can be mentioned.

Examples of the (meth) acrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and the like.
N-butyl (meth) acrylate, isobutyl (meth) acrylate, n-octyl (meth) acrylate, (meth)
Dodecyl acrylate, 2-ethylhexyl acrylate,
In addition to alkyl (meth) acrylates such as stearyl acrylate, 2-chloroethyl acrylate, (meth) acrylate
Phenyl acrylate, α-methyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate,
Glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate, methacryloxyethyl phosphate, and the like, among which, in particular, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, Methyl methacrylate is preferred.

As the above-mentioned monomer having a hydroxyl group, use of a hydroxylated styrene derivative, a (meth) acrylic acid derivative or the like is preferable. As the hydroxylated styrene derivative, for example, hydroxystyrene, hydroxylmethylstyrene, hydroxylethylstyrene or the like is used. And examples of the (meth) acrylic acid derivative include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

Examples of the monomer having a nitrogen-containing group include (meth) acrylamide, dimethylamino (meth) acrylate, and vinylpyridine.

The vinyl copolymer contains 1 to 30% by weight of a monomer having a hydroxyl group and / or a nitrogen-containing group. When the content of the monomer having a hydroxyl group and / or a nitrogen-containing group is less than 1% by weight, the effect of the interaction with the low molecular weight crystalline compound is not exhibited, and it is used as the low melting crystalline compound described later. The acid amide compound bleeds out. Further, when the content of the monomer having a hydroxyl group and / or a nitrogen-containing group exceeds 30% by weight, the cohesive force between the vinyl copolymers increases, and the acid amide compound is further removed from the vinyl copolymer component. Compatible and inhibits low-temperature fixability.

The above acid amide compound is used as a low-melting crystalline compound and is represented by the general formula R-CONH ₂ .
In the formula, R represents an alkyl group. When the number of carbon atoms in the alkyl group is small, the melt viscosity is low and bleed out is remarkable. Examples of such an acid amide compound include long-chain acid amide compounds such as behenamide, stearamide, and erucamide.

The content of the acid amide compound in the toner resin composition of the present invention is limited to 1 to 30% by weight.
When the content of the acid amide compound is less than 1% by weight, the crystallinity of the obtained toner is reduced and does not contribute to the improvement in low-temperature fixability. When the content exceeds 30% by weight, the plasticization of the vinyl copolymer is reduced. Progress and the preservability decreases.

Examples of the method for producing the resin composition for toner include a method in which an acid amide compound or the like is added to a vinyl copolymer and the mixture is melt-kneaded by a roll mill, a kneader, an extruder, or the like. A method in which an acid amide compound or the like is added during the production (polymerization) process of the polymer is exemplified.

As a method for obtaining a toner from the resin composition for a toner, for example, a colorant and other additives are mixed with the resin composition for a toner, and then mixed with a roll mill.
Melt kneading with a kneader, an extruder, etc., then, after cooling, pulverizing using a pulverizer such as a jet mill, and further classifying as necessary to obtain toner particles having a particle size of 5 to 20 μm. No.

Examples of the coloring agent include carbon black, chrome yellow, aniline blue, phthalocyanine blue, ultramarine blue and the like.

The above-mentioned other additives are added as needed, and include, for example, a charge control agent, a release agent, and magnetic fine particles.

Examples of the charge control agent include a nigrosine dye, a spiron black dye, and a phthalocyanine pigment. Examples of the release agent include polypropylene, polyethylene, ethylene-propylene copolymer and the like. As the magnetic fine particles, for example,
Metals such as nickel, manganese, iron, cobalt and chromium;
Various ferrites; fine powders of various alloys and the like.

A fluidizing agent may be added to the toner obtained above in order to enhance the fluidity as a powder.
Examples of the fluidizing agent include hydrophobic silica powder, acrylic resin powder, fluorine resin powder, and metal salt powder of higher fatty acid.

[0024]

In the toner resin composition of the present invention, the acid amide compound used as the low-melting crystalline compound is converted into a vinyl copolymer by the intermolecular force of hydrogen bond partially formed by the polar effect of the terminal functional group. Interacts with coalescing components,
It can be pseudo-grafted to form an aggregated structure. By adopting such an agglomerated structure, bleed out of the low-melting crystalline compound is prevented, and the glass transition point (Tg) of the vinyl copolymer is reduced.
It is possible to provide a toner having more excellent fixability (especially in a lower temperature range) and excellent anti-offset properties while maintaining good storage stability.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 880 g of toluene was placed in a 3 L separable flask, and 60 g of a St-BA-MMA copolymer having a weight average molecular weight (Mw) of 2,000,000 and 60 g of stearamide (a crystalline compound having a low melting point) were charged. And dissolved. After replacing the gas phase in the separable flask with nitrogen gas, the system was heated to the reflux temperature of toluene. While stirring with refluxing toluene, 480 g of styrene, butyl acrylate 2
4 g, 72 g of methyl methacrylate and 24 g of 2-hydroxyethyl methacrylate, and azobisisobutyronitrile 3 as a polymerization initiator.
Solution polymerization was performed while dropping the mixture in which 3 g was dissolved over 2.5 hours. After completion of the dropwise addition, the mixture was aged for 30 minutes while stirring at the reflux temperature of toluene. Then
While gradually raising the temperature of the oil bath to 160 ° C., toluene was removed under reduced pressure to obtain a resin composition. This resin composition was cooled and pulverized to obtain a resin composition for toner.

Example 2 A toner resin composition was obtained in the same manner as in Example 1 except that 60 g of behenamide was used as the low-melting crystalline compound instead of stearamide.

Example 3 Example 2 was repeated except that 24 g of N, N'-dimethylaminoethyl methacrylate was used instead of 2-hydroxyethyl methacrylate as a monomer having a polar group.
In the same manner as in Example 1, a resin composition for toner was obtained.

Example 4 As a low-melting crystalline compound, 60 g of behenamide was used in place of stearamide and as a monomer having a polar group, N, N ′ was used instead of 2-hydroxyethyl methacrylate. A resin composition for toner was obtained in the same manner as in Example 1 except that 24 g of -dimethylaminoethyl methacrylate was used.

Example 5 Example 1 was repeated except that 12 g of 2-hydroxyethyl methacrylate and 12 g of N, N'-dimethylaminoethyl methacrylate were used as monomers having a polar group.
In the same manner as in the above, a resin composition for toner was obtained.

Example 6 90 g of stearamide as a low melting crystalline compound
Used, 480 g of styrene, butyl acrylate 24
g, a resin composition for toner was obtained in the same manner as in Example 1 , except that a monomer composition consisting of 48 g of methyl methacrylate and 44 g of 2-hydroxyethyl methacrylate was used.

Example 7 An St-BA-MMA copolymer having a Mw of 1.7 million was mixed with 120
g, and a resin composition for toner was obtained in the same manner as in Example 1 except that 29 g of azobisisobutyronitrile was used as a polymerization initiator.

Comparative Example 1 A resin composition for toner was obtained in the same manner as in Example 1 except that a monomer composition comprising 480 g of styrene, 50 g of butyl acrylate and 70 g of methyl methacrylate was used.

Comparative Example 2 A resin composition for toner was obtained in the same manner as in Example 1 , except that stearic acid amide, which was a crystalline compound having a low melting point, was not added at all.

Comparative Example 3 A resin composition for toner was obtained in the same manner as in Example 1 except that 60 g of lauric amide was added instead of stearic amide as a low-melting crystalline compound.

Comparative Example 4 240 g of behenamide was used instead of stearamide as the low-melting crystalline compound, and styrene 340 was used.
g, butyl acrylate 10 g, methyl methacrylate 10 g and 2-hydroxyethyl methacrylate 240
A resin composition for toner was obtained in the same manner as in Example 1 except that the monomer composition consisting of g was used.

With respect to the resin compositions for toner obtained in Examples 1 to 7 and Comparative Examples 1 to 4 , the following performance evaluation was performed.
There, the results are shown in Table 1. Further, after preparing a toner from the resin composition for a toner as described below, the following performance evaluation was performed, and the results are shown in Table 1 .

The following evaluation was performed for the above resin composition.
The results are shown in Table 1. (1) Weight average molecular weight (Mw) Two peaks on the molecular weight distribution obtained by using GPC were divided at valleys, and the weight average molecular weight (Mw) of each peak was calculated. GPC uses "HTR-C" manufactured by Nippon Millipore Limited as a device, and "KF-800P" (single) and "KF-806" manufactured by Showa Denko KK as columns.
M "(2) and" KF-802.5 "(1) were used in series. Measurement conditions were a temperature of 40 ° C., a sample concentration of 0.2% by weight tetrahydrofuran solution (passed through a 0.45 μm filter), and an injection amount of 100 μl was injected. Standard polystyrene was used as a calibration sample.

(2) Glass transition temperature (Tg) and melting point (Tm) DSC obtained by using a DSC220C manufactured by Seiko Denshi Kogyo KK under measurement conditions of a heating rate of 10 ° C./min.
A curve (shown in FIG. 1) was created, and Tg was taken as the peak temperature for Tm from the intersection with the tangent line shown in FIG.

(3) Flow softening point (Tf) Flow tester “CFT-500” manufactured by Shimadzu Corporation
A ", the measurement conditions were: nozzle diameter 1.0 mm, load 20 kgf, measurement temperature was 80-200 ° C. by a temperature rising method, temperature rising rate 6 ° C./min, and preheating was 300 seconds, as shown in FIG. The middle point of the outflow was defined as the softening point (Tf).

[Preparation of Toner] 100 parts by weight of the above resin composition (a), 5 parts by weight of carbon black (“MA-100” manufactured by Mitsubishi Kasei Co., Ltd.) as a coloring agent, and Spiron black “TRH” 1 as a charge control agent Parts by weight and 3 parts by weight of PP wax (“Viscol 660P” manufactured by Sanyo Chemical Co., Ltd.) as a release agent are melt-blended, coarsely pulverized after cooling, and then finely pulverized with a jet mill (Labjet, manufactured by Nippon Pneumatic Industries, Ltd.) A toner powder having an average particle size of 8 to 12 μm was obtained. This powder was classified by a classifier (“MDS-2” manufactured by Nippon Pneumatic Industries, Ltd.) to produce a toner having an average particle size of 10 μm.

The following evaluation was performed on the above toner, and the results are shown in Table 1. (4) Storage property Take 10 g of the toner in a 100 ml sample bottle, and store at 50 ° C.
After standing for 8 hours in a high-temperature bath, the caking state was visually observed. (5) Temperature at which cold offset occurs 6.5 parts by weight of toner is mixed with 93.5 parts by weight of an iron powder carrier having a particle size of about 50 to 80 μm to prepare a developer, and the following evaluation is performed using this developer. Was. The image test is performed at a set temperature of the heat roller of the electronic copying machine from a temperature lower than the fixing temperature of the toner to a temperature as high as about 200 ° C. including the fixing temperature. At this time, if the temperature is lower than the fixing temperature, a double image is formed. However, the double image is eliminated near the fixing temperature. The temperature at which this double image occurs is defined as the temperature at which the cold offset occurs. (6) Fixing temperature In the above (5), when the temperature is further increased after the double image is eliminated, the fixing of the image becomes strong, and the temperature at which the image is reduced by 85% even when friction is observed is observed. Is done. This temperature was taken as the fixing temperature. (7) Offset occurrence temperature In the above (6), when the temperature is further increased, a double image is formed again. This temperature was taken as the temperature at which the offset occurred. The electrophotographic copying machine used in the above (5) to (7) is "Vision300" manufactured by Fuji Xerox Co., Ltd.
It is a modified version.

Preservability 20 g of toner is placed in a 200 ml sample bottle, and
℃, 50 ℃, after standing for 24 hours in a constant temperature bath of 55 ℃, sieving with a sieve at 40 rpm, 1 minute conditions,
If the remaining amount of the sieve having an opening of 250 μm was 5% or less, it was judged as acceptable. In the table, when the residual amount is less than 5% at 55 ° C., the residual amount at that time is indicated, and when the residual amount exceeds 5% at a temperature of 45 ° C. or 50 ° C., The temperature and residual amount of the thermostat were shown.

Measurement of acid value 2.0 g of the vinyl copolymer (sample) was precisely weighed and dissolved in 30 ml of methyl ethyl ketone.
1 / 50N with phenolphthalein solution as indicator
Potassium hydroxide / isopropyl alcohol solution (KO
H / IPA solution), and the acid value was calculated from the following formula. Acid value (KOH mg / g) = [(1/50) × F × 56.11 × (A−B)] / M where F: titer of 1 / 50N KOH / IPA solution A: required for titration of solution Amount of KOH / IPA solution B: Amount of KOH / IPA solution required for titration in blank test (only methyl ethyl ketone) M: Weight of sample

[0045]

[Table 1]

In Comparative Example 2 , the melting point (Tm) could not be measured because no crystalline compound having a low melting point was added. In Comparative Example 4 , the fixing temperature could not be measured because an offset occurred in the entire temperature range.

[0047]

The resin composition for a toner of the present invention has the above-mentioned constitution, and a low-molecular-weight vinyl copolymer and / or a high-molecular-weight vinyl copolymer and an acid amide compound have a side chain of the same. Acid amidation due to the aggregation structure due to the influence
Bleed out of the compound is prevented. Therefore, the toner obtained from the above resin composition for toner has excellent storage stability and excellent fixing properties at low temperatures and offset resistance.

[Brief description of the drawings]

FIG. 1 is a graph showing a GPC curve of a resin composition for a toner.

FIG. 2 is a graph showing a DSC curve of a resin composition for a toner.

FIG. 3 is a graph showing a flow curve of a resin composition for a toner.

[Explanation of symbols]

 Tg Glass transition point Tm Melting point ΔH Endotherm Tf Softening point

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-6-208246 (JP, A) JP-A-7-219269 (JP, A) JP-A-7-64323 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08L 25/00-25/18 C08K 5/20 C08L 33/06-33/12 G03G 9/087

Claims (2)

(57) [Claims] 1. A styrene monomer and (meth) acrylic acid
Vinyl copolymer containing ester monomer as a structural unit
When the general formula R-CONH ₂ (wherein, R 14 or more carbon atoms
And an acid amide compound represented by
A resin composition for a toner as a component,
The copolymer has a low weight average molecular weight (Mw) of 3,000 to 50,000.
Molecular weight polymer component and weight average molecular weight (Mw) = 100,000-
Consisting of 5 million high molecular weight polymer components,
1 to 30% by weight of a monomer having a nitrogen-containing group
Wherein the acid amide compound is contained in the resin composition in an amount of 1
About 30% by weight
Resin composition. 2. A toner comprising the toner resin composition according to claim 1 .