JP2581674B2 - Developer for electrostatic latent image - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a developer for electrostatic latent images containing a color negatively charged toner for electrophotography, in which a colorant is dispersed in a binder resin.

2. Description of the Related Art Conventionally, as a toner in an electrostatic latent image developer, a toner in which a dye or pigment is dispersed in a binder such as polyester is used.
Particles finely pulverized to about 30 μm are used, and such a toner is used by being mixed with a carrier substance such as glass beads, iron powder or fir.

Such a developer has problems that it is difficult to be charged to a desired polarity, is easily affected by a change in humidity, and is easily deteriorated by continuous use.

A black toner using a mixture of a specific unsaturated polyester resin and polystyrene as a binder resin has also been known (Japanese Patent Publication No. 51-16150), but has a practically problematic high minimum fixing temperature.

Object of the present invention is to solve the conventional problems as described above, and an object of the present invention is to provide an electrostatic latent image developer capable of forming a sharply colored image having an appropriate gloss, furthermore,
It is an object of the present invention to provide a developer in which a fixing temperature range is widened and a stain on a cleaning felt of a fixing portion is reduced even when used for a long time.

Structure The present invention relates to a developer toner comprising a colorant and a binder resin dispersed uniformly, and a polyester resin having a softening point of 50 to 150 ° C., which is synthesized from a bisphenol-type diol and a polycarboxylic acid as a binder resin. , Weight average molecular weight (M
w) / number average molecular weight (Mn) is 3.5 or more and Mw is 100000
An electrostatic latent image developer comprising a toner comprising the above-mentioned styrene-based polymer or styrene-based monomer and an acrylic acid derivative copolymer resin.

The following are exemplified as bisphenol-type diols used in the production of the polyester resin.

(1) Polyoxypropylene (2,2) -2,2-bis (4-
(Hydroxyphenyl) propane (2) polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane (3) polyoxystyrene (6) -2,2-bis (4-hydroxyphenyl) propane (4 ) Polyhydroxybutylene (2) -2,2-bis (4
-Hydroxyphenyl) propane (5) polyoxypropylene (3) -bis (4-hydroxyphenyl) thioether (6) polyoxypropylene (2) -2,2-bis (4-
(Cyclohexanol) propane (7) polyoxyethylene (2) -2,6-dichloro-4
-Hydroxyphenyl (8) polyoxyethylene (2,5) -p, p-bis-phenol (9) polyoxybutylene (4) bis (4-hydroxyphenyl) ketone (10) oxyethylene-2,2-bis (4-hydroxyphenyl) propane (11) oxypropylene-2,2-bis (4-hydroxyphenyl) propane Further, as the polycarboxylic acid, maleic acid, fumaric acid, glitalic acid, phthalic acid, maleic anhydride, Fumaric anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid, 1,2,4 benzenetricarboxylic acid and the like.

Examples of the polyester resin include the following.

(1) Softening point of 100 ° C with diol and fumaric acid, (2) Softening point of 90 ° C with diol and terephthalic acid, (5) Softening point of 110 ° C with diol and isophthalic acid
Those having a softening point of 130 ° C due to diol and fumaric acid and trimellitic acid of (1), and those having a softening point of 100 ° C due to diol and fumaric acid of (10).

Examples of the styrene monomer used for synthesizing a styrene polymer or a copolymer with an acrylic acid derivative used together with the polyester resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and p-methylstyrene. -Ethylstyrene, 2,4-dimethylstyrene, p
-N-butylstyrene, p-tert-butylstyrene, p
-N-hexylstyrene, pn-octylstyrene,
pn-nonylstyrene, pn-decylstyrene, p
-N-dodecylstyrene, p-methoxystyrene, p-
Phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene and the like, and acrylic acid derivatives such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, acrylic acid n-octyl, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate , N-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Ruaminoechiru, alpha-methylene aliphatic monocarboxylic acid esters such as diethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, acrylic acid or methacrylic acid derivatives such as acrylamide.

Then, the aforementioned Mw and Mn are measured by the following measuring methods. That is, the values are all measured by gel permeation chromatography under the following conditions. Temperature 25
At 0 ° C., a solvent (tetrahydrofuran) is allowed to flow at a flow rate of 1 ml per minute, and 8 mg of a tetrahydrofuran sample solution having a concentration of 0.4 g / dl is injected to perform measurement. When measuring the molecular weight of a sample, select a measurement condition in which the molecular weight distribution of the sample is within a range in which the logarithm of the molecular weight and the count number of the calibration curve prepared by using several types of monodisperse polystyrene standard samples are linear. I do. In this measurement, the reliability was NBS706 polystyrene standard sample (Mw =
Mw / Mn of 28.8 × 10 ⁴ , Mn = 13.7 × 10 ⁴ , Mw / Mn = 2.11) is 2.
Confirm that it is 11 ± 0.10.

The reason for limiting Mw / Mn is that if Mw / Mn is less than 3.5 during kneading of the toner, the structure and molecular weight of the resin will change when a force is applied to the resin component. For example, if the temperature is less than 3.5, the hot offset occurrence temperature becomes low.

When Mw is 100000 or more, to suppress gloss,
It is necessary to make the fixing lower limit temperature slightly higher and the hot offset occurrence temperature slightly higher to widen the fixing temperature range. If it is less than 100,000, the above effect is difficult to obtain.

The proportion of the polyester resin in the binder resin,
A range from 82.5 to 95% by weight is suitable.

The colorant used together with the binder resin is not particularly limited, but is preferably, for example, a benzidine-based yellow organic pigment, a magenta-colored organic pigment, a phthalocyanine-based blue organic pigment, or a black pigment. Are exemplified.

Benzidine yellow organic pigment CI21090 (Pigment Yellow 12), CI21095 (Pigment Yellow 14), CI21100 (Pigment Yellow 1)
3) alone or as a mixture.

Magenta organic pigment Xanthen pigment Red 81 (CI 45160), quinacridone 2,9 dimethyl quinacridone, methine astraphloxine dye, thioindigo Vat Red 2 (CI
78865), azo lake brilliant carmine 6B (CI
15850) and the like.

Phthalocyanine-based blue organic pigment Compound classified into CI Pigment Blue 15 and CI Solvent Blue 70, or CI No. 74260, 74280, 74255, 74
160, 74180, etc.

Black pigment: manufactured by Mitsubishi Kasei Corporation: Carbon # 30, # 33, # 40, # 44, # 45,
MA-8, MA-11, MA-100 Tokai Electrode: Seagull 3C, Seast H Nippon Chemical: Carbon Nippir, N-115 Cabot: Vulcan XC-72R, Regal 400R, Carbolac
2, Monarch 81, Elftex 5, Regal 330R, Sterling 99R Degussa: printex U, Printex 140V, Lamp BLACK 70
0, Regent Super, Printex 60, Corax L Asheland Chemical Co .: United 3004, United 301
2. United XC-3016 In the present invention, by appropriately changing the mixing ratio of the polymer in the binder, the fixing temperature range of the image (hot offset occurrence temperature-fixing lower limit temperature) is widened to stabilize the fixing device. Can be measured. Thereby, the stain on the cleaning felt of the fixing roller is extremely reduced, and the gloss of the image is moderately suppressed, and a beautiful colored image can be obtained.

The fixing temperature range is desirably at least 30 ° C. The reason for this is that the fixing roller temperature is set higher (10 to 20 ° C.) than the fixing lower limit temperature in anticipation of a decrease in the roller surface temperature during paper passing. In addition, the control width of the roller surface temperature is too narrow to be recognized, and the variation is large. Therefore, it is desirable that the fixing temperature width be as wide as possible. The reason why the felt of the fixing roller should be less stained is that if the cleaning felt becomes more than the cleaning capacity during continuous paper passing, the stain on the roller surface will not be cleaned, and consequently the copy paper will be stained.

 Hereinafter, specific examples will be described.

Example of toner containing benzidine-based yellow organic pigment Example 1 95 parts by weight of polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight CI No. 21090 (Symuler Fast Yellow GF, manufactured by Dainippon Ink) 5 parts by weight The above components were kneaded with a hot roll, crushed and classified to obtain a toner having an average particle diameter of 12.5 μm. 1.0% by weight of hydrophobic silica (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.)
After mixing, a toner A was obtained.

Hereinafter, the toner ratios of the toners BF shown in Table 1 were changed by changing the resin ratio in the same manner.
I got

95 parts by weight of carrier iron powder (TEFV 200/300 manufactured by Nippon Iron Powder Co., Ltd.) is mixed with 5 parts by weight of the toner obtained as described above to obtain a developer. The test was performed and the test results are shown in Table 2.

To evaluate the fixability, the surface of the roller was treated with silicone rubber (KE
1300, manufactured by Shin-Etsu Chemical Co., Ltd.) and a pressure roller formed of polytetrafluoroethylene (Teflon, manufactured by DuPont). The paper was examined by changing the unfixed image. In addition, the continuous paper passing test for the cleaning felt of the fixing roller cleaning felt was performed using an electrophotographic copying machine (FT4060
(Manufactured by Ricoh Co., Ltd.) and the fixing roller temperature was set to be 20 ° C. higher than the minimum fixing temperature.

From the above results, by adding a styrene resin (5-
20 copies) Since the fixing temperature range is widened, dirt on the cleaning felt attached to the fixing roller is reduced during continuous paper feeding.

The toner F of the comparative example is 100% polyester, and has a narrow fixing temperature range, resulting in an image having a high gloss. Also, when 20 parts by weight of styrene is added as in the case of the toner E, the lower limit temperature of fixing is slightly increased, which is not preferable for power saving fixing. Further, compared to the toners B to D, the image does not have an appropriate gloss and the image becomes invisible, and when the magenta toner or the cyan toner or both are superimposed, the image looks like a dull color. It looks bad.

Example 2 The polyester resin of Example 1 was used as in the above example, and a pigment was used.
When a developer was prepared and evaluated in the same manner as in Example 1 except that CI21100 (Symuler Fast Yellow GRF, manufactured by Dainippon Ink) was used, the same results as in Example 1 were obtained.

Example 3 Example 1 was repeated, except that the polyester resin of Example 1 was replaced with the above example and the pigments were replaced with those shown in Table 3, respectively.
A developer was prepared and evaluated in the same manner as in Example 1.
And similar results were obtained.

Example of Toner Containing Magenta Organic Pigment Example 4 Polyester resin 95 parts by weight Styrene-n-butyl methacrylate 5 parts by weight (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight of 2,9-dimethylquinacridone The above-mentioned components were kneaded with a hot roll and then pulverized and classified to obtain a toner having an average particle size of 12.5 μm. 1.0% by weight of hydrophobic silica (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.)
After mixing, a toner A was obtained.

Hereinafter, the toner ratios of the toners BF shown in Table 4 were changed by changing the resin ratio in the same manner.
I got

A developer was obtained in the same manner as in Example 1 using each of the toners obtained as described above, and a test was performed in the same manner as in Example 1. The test results as shown in Table 5 were obtained.

From the above results, by adding a styrene resin (5-
20 copies) Since the fixing temperature range is widened, dirt on the cleaning felt attached to the fixing roller is reduced during continuous paper feeding.

The toner F of the comparative example is 100% polyester, and has a narrow fixing temperature range, resulting in an image having a high gloss. Also, when 20 parts by weight of styrene is added as in the case of the toner E, the lower limit temperature of fixing is slightly increased, which is not preferable for power saving fixing. Further, compared to the toners B to D, the image does not have an appropriate gloss, and the image becomes invisible. In addition, when the yellow toner and the cyan toner or both are superimposed, the image looks like a dull color. It looks bad.

Example 5 The polyester resin of Example 4 was used as in the above example, and the pigment was Dainichi Fast Pink GX,
A developer was prepared and evaluated in the same manner as in Example 4 except that CI 45160 (manufactured by Dainichi Seika) was used, and the same results as in Example 4 were obtained.

Example 6 Example 4 was repeated, except that the polyester resin of Example 4 was replaced with the above example and the pigments were replaced with those shown in Table 6, respectively.
A developer was prepared and evaluated in the same manner as in Example 4.
And similar results were obtained.

Example of phthalocyanine-based blue organic pigment-containing toner Example 7 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight CI No. 74260 (Shimla Fast Blue 5007, manufactured by Dainippon Ink) 5 parts by weight The above components were kneaded with a hot roll, crushed and classified to obtain a toner having an average particle diameter of 12.5 μm. 1.0% by weight of hydrophobic silica (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.)
After mixing, a toner A was obtained.

Hereinafter, the toner ratios of the toners BF shown in Table 7 were changed by changing the resin ratio in the same manner.
I got

A developer was obtained in the same manner as in Example 1 using each of the toners obtained as described above, and a test was performed in the same manner as in Example 1. The test results as shown in Table 8 were obtained.

From the above results, by adding a styrene resin (5-
20 copies) Since the fixing temperature range is widened, dirt on the cleaning felt attached to the fixing roller is reduced during continuous paper feeding.

The toner F of the comparative example is 100% polyester, and has a narrow fixing temperature range, resulting in an image having a high gloss. Also, when 20 parts by weight of styrene is added as in the case of the toner E, the lower limit temperature of fixing is slightly increased, which is not preferable for power saving fixing. Further, compared to toners B to D, the image does not have an appropriate gloss and the image becomes invisible, and when yellow toner or magenta toner or both are superimposed, it looks like a dull color. It looks bad.

Example 8 The same treatment as in Example 7 was carried out except that the pigment of Example 7 was replaced with 2.5 parts by weight of CI Pigment Blue 15 (CI47160, manufactured by Lionol Blue F, Toyo Ink) and 2.0 parts by weight of oil blue (# 615, manufactured by Orient Chemical) With similar results.

Example 9 Example 7 was repeated, except that the polyester resin of Example 7 was replaced with the above example, and the pigments were replaced with those shown in Table 9, respectively.
A developer was prepared and evaluated in the same manner as in Example 7.
And similar results were obtained.

Example of toner containing black pigment Example 10 95 parts by weight of polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.) 5 parts by weight The above components were kneaded with heat and then pulverized and classified to obtain a toner having an average particle diameter of 12 μm. This toner has hydrophobic silica (Aerosil
R-972, manufactured by Nippon Aerosil Co., Ltd.) was mixed in a weight ratio of 1.0% by a Henschel mixer to obtain a black toner A.

Hereinafter, the toner ratios of the toners B to G shown in Table 10 were changed by changing the resin ratio in the same manner.
I got

Using each of the toners obtained as described above, a developer was obtained in the same manner as in Example 1, and a test was performed in the same manner as in Example 1. The test results shown in Table 11 were obtained.

From the above results, by adding a styrene resin (5-
20 copies) Since the fixing temperature range is widened, dirt on the cleaning felt attached to the fixing roller is reduced during continuous paper feeding.

The toner F of the comparative example is 100% polyester, and has a narrow fixing temperature range, resulting in an image having a high gloss. Also, when 20 parts by weight of styrene is added as in the case of the toner E, the lower limit temperature of fixing is slightly increased, which is not preferable for power saving fixing. Further, the images do not have a proper gloss as compared with the toners A to D, so that the images are invisible. Further, the toner having a 100% styrene resin like the G toner of Comparative Example also has a high minimum fixing temperature, requires a large amount of electric power, and is not preferable for power-saving fixing.

A toner was prepared in the same manner as in Example 10 except that the toner composition was changed as described below, and a similar test was performed.

Example 11 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon # 44 (manufactured by Mitsubishi Chemical Corporation) 10 parts by weight Example 12 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon # 45 (manufactured by Mitsubishi Chemical Corporation) 10 parts by weight Example 13 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon Seast H (manufactured by Tokai Electrode Co., Ltd.) 10 parts by weight Example 14 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon Vulcan XC-72R (manufactured by Cabot) 10 parts by weight Example 15 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴⁾ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon nipple (manufactured by Nippon Steel Chemical Co., Ltd.) 10 parts by weight Example 16 95 parts by weight of the polyester resin of the above example Styrene-n-butyl methacrylate (st / n BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn =
5) 5 parts by weight Carbon Elfex 5 (manufactured by Cabot Corporation) 10 parts by weight Example 17 Styrene-n-butyl methacrylate of Example 16 (st / n
BMA = 7/3, Mw = 15 × 10 ⁴ , Mn = 3 × 10 ⁴ , Mw / Mn = 5)
Styrene-n with Mw = 20 × 10 ⁴ , Mn = 5 × 10 ⁴ , Mw / Mn = 4
A toner was obtained and evaluated in the same manner as in Example 16 except that butyl methacrylate was used, and the same results as in Table 11 were obtained.

Example 18 Carbon of toner C of Example 10 was replaced with a benzidine-based yellow pigment (Shimra Fast Yellow GF manufactured by Dainippon Ink), a magenta pigment (Simrex Rhodamine Y manufactured by Dainippon Ink), and a cyan pigment (Fastogen Blue GS manufactured by Dainippon Ink) )
A yellow, magenta and cyan pigment-containing toner was obtained and a developer was prepared in the same manner as in Example 10, except for changing the above.
A color image was developed as follows using the three kinds of developers obtained as described above together with a black toner. That is, the portion corresponding to the black image in the color image is developed and transferred with each black toner shown in Table 10. Next, the image portion separated into blue, green and red was developed and transferred with the above three kinds of developers to obtain an unfixed color image on transfer paper. (Each image was developed four times using each of the four color developers,
When the unfixed color image thus obtained was fixed, a black toner containing a styrene resin (A-
The image obtained using E) has moderate gloss, yellow,
A beautiful image equivalent to magenta and cyan toners was obtained. On the other hand, when the above three types of developers are used in combination with the toner F, the image gloss of the black toner portion is too strong,
Further, when combined with the toner G, not only is the image lacking in gloss due to insufficient gloss and an invisible image,
The resulting image was less visible than the yellow, magenta, and cyan toners.

Effect In the present invention, by using a binder resin composed of a specific resin, the fixing temperature range can be widened without abnormally increasing the minimum fixing temperature of the toner. As a result, the cleaning felt of the fixing roller is less contaminated, and consequently the copy paper is not contaminated. Further, the gloss of the image can be appropriately suppressed, and a beautiful colored image can be obtained.

Claims (5)

(57) [Claims] 1. A polyester resin having a softening point of 50 to 150.degree. C., which is composed of a colorant and a binder resin uniformly dispersed, wherein the binder resin is synthesized from a bisphenol-type diol and a polyvalent carboxylic acid. Molecular weight (Mw) / number average molecular weight (Mn)
A toner which is a styrene-based polymer or a styrene-based monomer and an acrylic acid derivative copolymer resin having a Mw of 3.5 or more and an Mw of 100,000 or more. 2. The developer for an electrostatic latent image according to claim 1, wherein the colorant is a benzidine-based yellow organic pigment. 3. The developer for an electrostatic latent image according to claim 1, wherein the coloring material is a magenta organic pigment. 4. The developer for an electrostatic latent image according to claim 1, wherein the colorant is a phthalocyanine blue organic pigment. 5. The developer for an electrostatic latent image according to claim 1, wherein the coloring material is a black organic pigment.