JPH04114169A - Toner - Google Patents

Abstract

PURPOSE:To contrive the improvements of a migration property to vinyl chloride, the environmental safety, the low temp. fixation and a lower cost by using a polyester resin, a styrene-acryl resin and an oxazoline reactive polymer, as a toner binder composition for electrostatic charge development. CONSTITUTION:As the electrostatic charge developing tone binder composition at least the polyester resin, the styrene-acryl resin, the oxazoline reactive polymer and a coloring agent are incorporated. As the toner binde resin, 2-9 wt. parts of the styrene-acryl resin, 2-98 wt. parts of the polyester resin and 0.01-5 wt. parts of the oxazoline reactive polymer are used. Hence the toner of the improved migration property to vinyl chloride and of high blackness and being excellent in the environmental stability and the low temp. fixation and of a lower cost is obtained.

Description

[Detailed Description of the Invention] [Summary] Regarding toner used for developing electrostatic latent images such as electrophotography, it has good PVC transferability, high blackness, excellent environmental stability, low temperature fixability, Aiming to provide a low-cost toner, using a styrene-acrylic resin as a binder resin [Field of Industrial Application] The present invention relates to a toner used for developing electrostatic latent images in electrophotography and the like.

As an electrophotographic method, the method described in US Pat. No. 2,297,691 and the like is well known. This generally involves using a photoconductive insulator (such as a photocondrum), applying a -like electrostatic charge on the photoconductive insulator by corona discharge, etc., and applying various means to the photoconductive insulator. An electrostatic latent image is formed by irradiating the image with a light image, and then the latent image is developed and visualized using fine powder called toner. After transferring the toner image to paper etc. as necessary, pressure is applied. The toner image is melted and fixed on paper or the like by heating, solvent, steam, light, etc. to obtain a printed matter. Toners for developing these electrostatic latent images have conventionally been prepared by dispersing coloring agents such as dyes and carbon black in a binder resin made of natural or synthetic polymeric substances, which is finely pulverized to about 1 to 30 μm. particles are used.

Unlike copying machines, optical printers output original images, so the printed matter must have high print quality and be able to be stored for a long period of time.The toner also has the contradictory characteristics of low cost and high functionality. There is a growing need for a balance between the two. One of the advanced functions of toner is PVC migration resistance.Recently, the field of application for printing with printers has expanded to include important documents such as various insurance cards and resident registers. This characteristic prevents the toner from sticking to the sheet, which is a problem when the toner is filed on a sheet (also called a PVC sheet). Conventionally known toner materials with good PVC migration resistance include epoxy resins and polyester resins, but since these resins are relatively expensive, they are generally replaced with low-cost styrene-acrylic resins. is used. However, styrene-acrylic toners have poor vinyl chloride resistance, so their use as toners for printers has been limited. Therefore, if the PVC migration resistance of a toner containing styrene-acrylic resin as a main component mixed with polyester resin can be improved, it is highly likely that it will be possible to achieve both lower price and higher functionality for use in printers.

[Prior art and problems to be solved by the invention] As a method for solving the above-mentioned PVC transfer resistance of styrene-acrylic toner, for example ) ■A method of copolymerizing a water-soluble monomer with a high hydroxy value to make the solubility parameter of a toner binder far from that of dioctyl phthalate (DOP) in a PVC sheet (JP-A-59-166965; JP-A-Sho 60- 164754, etc.) ■Method of copolymerizing imide group-containing methacrylate monomers (JP-A-62-81643, JP-A-63-165867)
, JP-A-63-271272, etc.) are known.

In general, polyester resins and styrene-acrylic resins are not compatible with each other and have a so-called sea-island structure. When simply kneading a well-known polyester resin into a styrene-acrylic resin, as in (2), due to this sea-island structure, carbon black,
The dispersion of colorants such as dyes and magnetic materials into the binder is inhibited, and both resins gather at the interface, resulting in toners that are not very black and pale in color despite containing a considerable amount of colorant. Becomes toner. Although some effect on PVC migration resistance is recognized, since the two resins are hardly compatible, even when a small amount of styrene-acrylic resin is contained, plasticizers for PVC (such as dioctyl phthalate, hereinafter referred to as DOP) ) and transfers to PVC. Furthermore, if a larger amount of polyester resin is contained, environmental stability will be lacking.

In addition, when adding a water-soluble special additive such as hydroxyethyl methacrylate as in (2), the effect will not appear unless it is added at least 40 parts by weight per 100 parts by weight of the binder.
Not only is the cost high, but the toner lacks environmental stability and loses its balance as a toner.

In the case of (3), if 30 parts by weight or more are not mixed, there will be no effect on PVC migration resistance, and the balance of environmental stability and low-temperature fixing properties will be lost, making it difficult to achieve both low cost and high functionality as a printer toner. There was little chance of success.

Therefore, by the conventional methods, it has not been possible to obtain a low-cost toner that has good vinyl chloride migration properties, high blackness, environmental stability, and low-temperature fixability.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a low-cost toner that has good vinyl chloride migration properties, high blackness, excellent environmental stability and low-temperature fixability.

[Means for Solving the Problems] As a result of intensive research, the present inventors found that by including at least a polyester resin, a styrene-acrylic resin, an oxapurine-based reactive polymer, and a colorant as a toner binder composition for electrostatic charge development, The present inventors have discovered that it is possible to produce a low-cost toner for electrostatic charge development that has good vinyl chloride migration properties, high blackness, excellent environmental stability, and low-temperature fixability, and has led to the present invention.

That is, the present invention uses 2 to 98 parts by weight of styrene-acrylic resin, 2 to 98 parts by weight of polyester resin, and 0.01 to 5 parts by weight of oxazoline-based reactive polymer as the binder resin for toner.

The present invention will be explained in more detail below.

In general, existing polyester resins exhibit faster melting properties and wider fixing margins than styrene acrylic resins.
Although the vinyl chloride migration resistance is good, the environmental stability is poor due to the influence of the hydroxyl group and carboxyl group of the reactive residue. On the other hand, styrene-acrylic resin has good environmental stability, but has a narrow fixing margin and poor PVC migration resistance.

As a means to satisfy the advantages of both resins, we investigated a mixture of polyester resin and styrene-acrylic resin. As already mentioned, if the two resins are simply kneaded together, they will not be compatible and the disadvantages of each will become apparent, resulting in a toner with poor environmental stability, a narrow fixing margin, and poor PVC migration resistance. . Furthermore, the sea-island structure of the resin causes poor dispersion of the colorant, resulting in a gray toner, resulting in dark prints even after fixing on paper.

In view of the above results, a method for improving the compatibility between polyester resin and styrene-acrylic resin was investigated. A known method for achieving this is crosslinking, that is, a method in which a polyester resin and a styrene-acrylic resin are modified and further crosslinked using a reactive crosslinking agent (Japanese Patent Application Laid-Open No. 104956/1983). Since this method crosslinks during kneading, it is difficult to control this crosslinking reaction, and the resin may gel, resulting in poor productivity. Furthermore, even if this does not occur, the molecular weight distribution shifts to the high molecular weight side, resulting in poor fixing properties and making it impossible to maintain balance as a toner. Therefore, as a means to improve the compatibility between polyester resin and styrene-acrylic resin, there is a method of using an oxazoline-based reactive polymer without using a crosslinking agent. The oxazoline-based reactive polymer shown here is a styrene, acrylic, styrene-acrylonitrile, or styrene-acrylic polymer having an oxazoline group, and the oxazoline group reacts with the hydroxyl group and carboxyl group of the reactive residue of the polyester resin, It has a structure in which polystyrene (or polyacrylate) is added to the end of a polyethyl molecule. Both resins dissolve together through this oxazoline-based reactive polymer portion, improving compatibility. In this method, crosslinking of the resin does not occur, so there is little change in molecular weight distribution due to reaction, and low-temperature fixing can be achieved.

However, the amount of polyester resin is desirably 2 parts by weight or more based on the total parts by weight. If the amount is less than 2 parts by weight, vinyl chloride resistance and low-temperature fixing properties will be impaired. On the other hand, if the amount is 98 parts by weight or more, the environmental stability will deteriorate due to the hydroxyl groups and carboxyl groups in the polyester resin.

Further, when the composition of the polyester resin and the styrene-acrylic resin is kept at a constant ratio, the vinyl chloride migration resistance and environmental stability are greatly improved compared to the case where no graft polymer is contained. This is because the carboxyl groups and hydroxyl groups of the polyester resin react with the graft polymer, resulting in a decrease in hygroscopic groups.

Unlike the case where a crosslinking agent is used, the oxazoline-based reactive polymer does not gel, has excellent manufacturing stability, and does not have an adverse effect on fixing properties.

Commercially available oxazoline-based reactive polymers include RPS-
1001, RPS-1005, RAS-1005 (Nippon Shokubai Kagaku), etc.

Further, it is desirable that the amount of the oxazoline-based reactive polymer be 0.01 parts by weight or more based on the total parts by weight. Preferably it is 1 part by weight. Oxazoline-based reactive polymer is 0.0
If the amount is less than 1 part by weight, the compatibility of both resins will not be improved, the blackness will be low, the toner will be pale in color, and the PVC transferability, environmental stability, and low-temperature fixing properties will also be poor. on the other hand,
Even if the amount is 10 parts by weight or more, the compatibility of both resins will not improve.

Here, styrene-acrylic resin refers to styrene, 2-ethylhexyl methacrylate, α-methylstyrene, 0
-Methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, chlorostyrene, bromostyrene, dichlorostyrene, dipromostyrene, p
- Phenylstyrene, tent butylstyrene, methyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, methyl acrylate, divinylbenzene, diallyl phthalate, maleic acid, maleic acid half ester, acrylonitrile, ethylene glycol dimethacrylate, ethylene glycol diacrylate, Suspension polymerization, emulsion polymerization, etc. using one or several types of radically polymerizable monomers such as trimethylolpropane trimethacrylate using an azo type or peroxide type initiator, etc.
Refers to resins produced by methods such as bulk polymerization or solution polymerization. Further, if necessary, carbon tetrachloride or a thiol compound may be used as a chain transfer agent.

As the polyester resin, a normal commercially available resin may be used, and either a crosslinked polyester resin or a non-crosslinked resin may be used. Alcohol components include ethylene oxide of bisphenol A, ethylene glycol, propylene glycol, neopentyl glycol, etc., and acid components include phthalic acid, succinic acid, isophthalic acid, trimellitic acid, maleic acid, etc. obtained by condensation polymerization. Refers to resin.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 Resin A (styrene:butyl acrylate=8:2.Mw/Mn=40.M1=15) as the binder resin
50 parts by weight, resin B (ethylene glycol: phthalic acid nitrimellitic acid = 3: 3: 1°Mw/Mn =
35. M I = 27. Oxidation = 25) 50 parts by weight and 1 part by weight of RPS-1001, carbon black (Black Pearls L; average particle size 24 mμ) as a coloring agent.
, specific surface area +38n (/g manufactured by Cabot), 5 parts by weight, azo dye (Bontron 5-34 Orient chemical type), 3 parts by weight, propylene wax (Viscol 550).
Add 4 parts by weight of P (manufactured by Sanyo Chemical Co., Ltd.), and add 1 part by weight using a pressure kneader.
The mixture was melt-kneaded at 30° C. for 30 minutes to obtain a toner mass. The cooled toner mass is crushed by a Rotoplex mill to about ~2Il1
m coarse toner.

Next, the coarse toner is passed through a jet mill (PJM pulverizer 2
The pulverized product was classified using a wind classifier (manufactured by Albine Co., Ltd.) to obtain toner having a particle size of 5 to 20 μm.

A developer consisting of 4 parts by weight of toner and 96 parts by weight of GF-120G (Kanto Denka type) as a carrier was prepared, and a fixing test was conducted using an M-3711L laser printer (Fujitsu type) that uses a hot roll fixing method. went.

PVC transferability was determined by using a PVC sheet containing 44% DOP, placing the PVC sheet on top of the printed sample, and heating at 50°C with 30% DOP.
A load of 50 g/cnr was applied to the printed sample in an RH environment, and after 12 hours, the printed sample and the PVC sheet were peeled off, and the transferability was visually judged.

Environmental stability was evaluated based on humidity versus charge retention in an environment of 25°C. The results are shown in Table 1.

Comparative Example 1 To 100 parts by weight of resin A as a binder resin, 5 parts by weight of carbon black (Black Pearls), 3 parts by weight of azo dye (Bontron S-34), and 4 parts by weight of propylene wax (Viscol 550P) were added. , Example 1
Toner was obtained in a similar manner.

Thereafter, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Comparative Example 2 To 100 parts by weight of resin 8 as a binder resin, 5 parts by weight of carbon black (Black Pearls), 3 parts by weight of azo dye (Bontron S-34), and 4 parts by weight of propylene wax (Viscol 550P) were added. A toner was obtained in the same manner as in Example 1.

Thereafter, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Lac Pearls L) 5 parts by weight, azo dye (Bontron S
-34) 3 parts by weight, propylene wax (viscol
A toner was obtained in the same manner as in Example 1 by adding 4 parts by weight of 550P).

Thereafter, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Example 2 95 parts by weight of resin A as binder resin, resin B
To 5 parts by weight, 5 parts by weight of carbon black (Black Pearls L), 3 parts by weight of azo dye (Bontron S-34), and 4 parts by weight of propylene wax (Viscol 550P) were added, and a toner was prepared in the same manner as in Example 1. I got it.

Thereafter, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Example 4 23 parts by weight of resin A and resin B as binder resin
69 parts by weight, 5 parts by weight of carbon black (Black Pearls L), 3 parts by weight of azo dye (Bontron S-34)
Part by weight, propylene wax (Viscol 550P)
A toner was obtained in the same manner as in Example 1 by adding 4 parts by weight.

Thereafter, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Example 3 69 parts by weight of resin A as binder resin, 8 parts by weight of resin
A toner was obtained in the same manner as in Example 1 without adding carbon black (Comparative Example 3 RPS-1001) to 23 parts by weight.

Thereafter, the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Comparative Example 4 A toner was obtained in the same manner as in Example 1 except that Resin A was modified with maleic acid, RPilool was not added, and a crosslinking agent (Bontron 5-32. Orient Chemical) was added instead. Thereafter, the same evaluation as in Example 1 was performed. Table 1 shows the results.
Shown below.

Example 5 A toner was obtained in the same manner as in Example 1 except that RPS-1001 was replaced with RAS-1005.

Thereafter, the same evaluation as in Example 1 was performed. As a result, the PVC migration properties, fixing properties, environmental stability, and blackness were fully satisfied.

Created toner.

5 parts by weight of this toner, unshaped iron powder TSV as a carrier
A developer consisting of 95 parts by weight of 100/200 (manufactured by Nippon Steel Powder) was prepared, and a flash fixing method was used. F
A printing test and a fixing test were conducted using an ACOM-67+50 laser printer. In addition, PVC transferability, environmental stability, and blackness were evaluated in the same manner as in Example 1.

As a result, the PVC migration properties, fixing properties, environmental stability, and blackness were fully satisfied.

Example 6 Instead of using carbon black and azo dye as the coloring agent in Example 1, a red pigment Quinaquiton pigment (Shinkasha Red, manufactured by DuPont) was used Table 1 Comparative Example 1 Example 2 Implementation N3 Example 1 Implementation Example 4 Comparative Example 2 Comparative Example 3 (1) Styrene: Butyl acrylate: Maleic acid = 7
8: 20: 2゜My/Mn-40, Ml-15
, AV-15 (2) Crosslinking agent Bontron 5-34 (3) Judging by the optical density (OD) of the PVC sheet after the test, ○・0D (0,1,x: OD>0.1 [Effect of the invention As explained above, according to the present invention, by using polyester resin, styrene-acrylic resin, and oxazoline-based reactive polymer as the toner binder composition for electrostatic charge development, vinyl chloride migration property is good and blackness is low. It is possible to obtain a toner for electrostatic charge development that has high environmental stability, excellent low-temperature fixability, and is low in cost.

Claims (1)

[Claims] As a binder resin, 2 to 98 parts by weight of styrene-acrylic resin and 2 to 98 parts by weight of polyester resin are used based on the total weight part.
Part by weight and oxazoline-based reactive polymer from 0.01 to
A toner characterized by using 10 parts by weight.