JPS6263940A - Toner for developing electrostatic image - Google Patents

Abstract

PURPOSE:To form an image at a high speed by incorporating a non-polyolefin crystalline polymer having a specific m.p., amorphous polymer having a specific glass transition temp. and polyolefin polymer into a binder. CONSTITUTION:The binder contains the non-polyolefin crystalline polymer having 50-120 deg.C m.p., amorphous polymer having 50-80 deg.C glass transition temp. and polyolefin polymer. The content ratio of the non-polyolefin crystalline polymer is preferably 0.5-50wt%, the content ratio of the amorphous polymer 50-99wt% and the content ratio of the polyolefin polymer 0.5-10wt%. The crystalline polymer is preferably a polyester resin, the polyolefin polymer is preferably PP or the PE or the modified resin thereof and has preferably 100-160 deg.C softening point. The softening point of the amorphous polymer is preferably 100-150 deg.C and further the crystalline polymer and the amorphous polymer are preferably non-compatible with each other.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrostatic image developing toner used for developing electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, etc. It is related to.

[Background of the invention]

For example, in electrophotography, an electrostatic latent image is usually formed by charging and exposing an electrostatic image carrier made of a photoconductive photoreceptor, and then this electrostatic latent image is placed in a binder made of resin with a coloring agent. The resulting toner image is transferred to a support such as transfer paper and fixed to form a visible image.

In order to obtain a visible image as described above, it is necessary to fix the toner image, and conventionally, a heat roller fixing method that has high thermal efficiency and can perform high-speed fixing has been widely adopted.

However, in recent years, there has been a strong demand for forming visible images at particularly high speeds, and from this point of view, it is necessary to perform the fixing process reliably and well in a wide temperature range while keeping the temperature of the heat roller lower. There is a strong demand for this, and there is a need for toners that fully satisfy these demands. This is because in high-speed image formation, the range of temperature change of the fixing heating roller is large.

Furthermore, the toner must be able to exist stably as a powder without agglomerating under the environmental conditions of use or storage, that is, it must have excellent blocking resistance. teeth,
Offset phenomenon: During fixing, part of the toner that makes up the image is transferred to the surface of the heat roller, and this is likely to be transferred again to the transfer paper that is sent next, staining the image. It is necessary to impart the performance of preventing the offset phenomenon from occurring, that is, the non-offset property. This offset phenomenon occurs when the viscoelasticity of the molten toner during fixing is not appropriate. When the toner is not heated enough, a phenomenon called under-offset occurs, and when the toner is heated excessively, a phenomenon called under-offset occurs. A phenomenon called offset occurs. Therefore, the toner has a low minimum temperature Tf at which it can be fixed, and a non-offset temperature range (under-offset generation temperature T) in which the offset phenomenon does not occur below this minimum fixing temperature Tf.
It is preferable that the fixing temperature range is wide within the temperature range below the hot offset generation temperature Th. It is desirable that this fixable temperature range be as wide as possible, since this makes it easy to increase the speed of image formation as long as other conditions permit.

[Conventional technology]

Conventionally, for example, as disclosed in Japanese Patent Publication No. 57-3658, a specific crystalline polymer having a melting point of 50 to 150° C. Techniques for use have been proposed.

Also crystalline polymers,! The combination of Jl crystalline polymers with silk to obtain electrostatic image developing toners with favorable properties has also been investigated.

[Problem that the invention seeks to solve]

However, in the conventional technology, the minimum fixing temperature T
Although it is possible to set f to a low temperature, the offset phenomenon is likely to occur, the temperature range in which fixing is possible is quite narrow, and strict conditions are currently imposed in order to achieve high-speed image formation. .

[Purpose of the invention]

The present invention has been made based on the following two circumstances, and its purpose is to have a low minimum fixing temperature 'I' and an extremely wide fixable temperature range, so that it is possible to achieve good results even in high-speed image formation. It is an object of the present invention to provide a toner for developing electrostatic images that has good fixing properties and can easily achieve high-speed image formation.

Another object of the present invention is to provide a toner for electrostatic image development that has sufficient fixing properties, excellent fluidity and charging properties, and can stably form good visible images. There is something for every thing you do.

[Means for solving problems]

The object of the present invention is that the binder has a melting point of 50 to 120°C.
This is achieved by an electrostatic image developing toner characterized by containing a non-polyolefin crystalline polymer, an amorphous polymer having a glass transition point of 50 to 80°C, and a polyolefin polymer. .

In the present invention, the content ratio of the non-polyolefin crystalline polymer is 0.5 to 50% by weight, the content ratio of the amorphous polymer is 50 to 99% by weight, and the content ratio of the polyolefin polymer is 0.5 to 50% by weight. It is preferably 10% by weight, the crystalline polymer is preferably a polyester resin, the polyolefin polymer is polypropylene or polyethylene or a modified product thereof, and the softening point is 100 to 160°C.
It is preferable that the amorphous polymer has a softening point of 1
The temperature is preferably 00 to 150°C, and further crystallized ('1
Preferably, the polymer and the amorphous P1 polymer are mutually incompatible.

[Effect]

According to such a tree for electrostatic image development, the resin constituting the binder is mainly composed of a specific crystalline polymer with a relatively low melting point and an amorphous polymer, and in addition, a polyolefin polymer. In particular, the effect of containing a polyolefin polymer can be greatly obtained, and not only the minimum fixing temperature Tf is low, but the fixable temperature range is extremely wide, and therefore high-speed image formation is possible. This can be easily achieved and good fixing properties can be obtained. Further, according to a preferred embodiment of the present invention, in addition to excellent fixing properties, good fluidity and charging properties can be obtained, and as a result, good visible images can be stably formed.

The present invention will be explained in detail below.

In the present invention, a non-polyolefin crystalline polymer having a melting point of 50 to 120°C and a glass transition point of 50 to 80°C are used.
A toner for electrostatic image development is obtained using a binder containing an amorphous polymer and a polyolefin polymer.

In the above, the content of the non-polyolefin crystalline polymer is 0.5 to 50% by weight, the content of the amorphous polymer is 50 to 99% by weight, and the content of the polyolefin polymer is 0.5 to IO weight. %, preferably 1 to 5% by weight.

The non-polyolefin-based crystalline polymer is preferably a polyester resin, so that the resulting toner has good fluidity and can form an excellent visible image.

Further, the amorphous polymer is preferably a copolymer of styrene and an acrylic ester or a methacrylic ester or a polyester resin, so that the resulting toner can be reliably maintained at its under-offset generation temperature Tu.
is low and the hot offset generation temperature Th is high.
Therefore, it has a wide fixable temperature range.

Further, it is preferable that the crystalline polymer and the amorphous polymer are mutually incompatible, so that the obtained toner is prevented from having a low glass transition point and has excellent anti-blocking properties.

The above-mentioned amorphous polymer and crystalline polymer are each 55 to
It is contained in the binder in the range of 99% by weight and 0.5 to 50% by weight, but if the content ratio of the amorphous f/1 polymer is too small, the minimum fixing temperature T' will not be low enough, and the crystalline If the content ratio of the amorphous polymer is too large, excellent image quality cannot be obtained.The content ratio of the amorphous polymer is preferably 6
It is 0 to 99% by weight.

The content of the crystalline polymer is preferably 3 to 40% by weight.

As the crystalline polymer used as a component of the binder in the present invention, a resin having a melting point Tm of 50 to 120°C is used. However, when a crystalline polymer having a melting point Tm of less than 50°C is used, the resulting toner has a high durability. The blocking property becomes poor,
On the other hand, if a temperature higher than 120° C. is used, it is naturally impossible to obtain a low minimum fixing temperature Tf.

Further, in the present invention, as the amorphous polymer used as a component of the binder, a resin having a glass transition point 'rg of 50 to 80°C is used. Glass transition point Tg of this amorphous polymer
When the value of is lower than 50°C, the resulting toner tends to have poor blocking resistance and poor pulverizability, while when it exceeds 80°C, the minimum fixing temperature Tf becomes high. In addition, the softening point measured by Koka type flow tester is 10.
Amorphous polymers having a temperature of 0 to 150°C are preferred.

The melting point Tm of the crystalline polymer and the glass transition point Tg of the amorphous polymer in the above can be measured as follows.

<Measurement of melting point Tm of crystalline polymer> According to differential scanning calorimetry (NSC), a crystalline polymer was used as a sample, and the sample was heated at a constant heating rate (10
The melting peak value when heated at ℃/m1n) is the melting point Tm
shall be.

<Measurement of the glass transition point "rg of an amorphous polymer" According to differential scanning calorimetry (DSC), 10 mg of the amorphous polymer was heated at a constant heating rate (10°C/m1).
n), and the glass transition point Tg is obtained from the intersection of the baseline and the slope of the endothermic peak.

In the present invention, the crystalline polymer includes polyester,
polyacrylic ester, polymethacrylic ester,
Polyaldehyde, polyene, polyacid, polylactone, polyacid anhydride, polyamide, polyurethane, polyoxadiazole, polyether, polyevihalohydrin, polysulfone, etc., "Polymer Handbook" [I4 Brand Wrap and F, l+, Inmergatsu Edit, iter
Science Publishing, New York, New York, No. 3
(1967), pages II+-51 to -59] can be used, but polyester resins are particularly preferably used.

The polyester resin used as the crystalline polymer in the present invention is obtained by polycondensation of alcohol and carboxylic acid, and alcohols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, ll3
- Diols such as propylene glycol, lI4-butanediol, neobentyl glycol, and 1,4-butynediol, 1,4-bis(hydroxymethyl)cyclohexane, and bisphenol A, hydrogenated bisphenol A1 polyoxyethylated bisphenol Etherified bisphenol A such as A1 polyoxypropylenated bisphenol A, and other dihydric alcohol monomers can be mentioned.

Examples of carboxylic acids include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, cepatic acid, malonic acid, Examples include anhydrides of these acids, dimers of lower alkyl esters and lyluic acid, and other divalent organic acid monomers.

In addition, in the present invention, not only a polymer containing only the above difunctional monomers but also a polymer containing a component composed of trifunctional or higher polyfunctional monomers is used as the crystalline polymer. It is suitable as a polyester resin. Examples of trivalent or higher polyhydric alcohol monomers that are polyfunctional propellants include sorbitol, L2,
3.6-hexanetetrol, 114-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, WtsHlI, 2.4-butanetriol, 1,2.5-pentanetriol, glycerol, 2-methyl Propanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3.5-trihydroxymethylbenzene, and others can be mentioned.

Examples of trivalent or higher polycarboxylic acid monomers include l,2,4-Hensentricarboxylic acid, 1,2,5-
Hensentricarboxylic acid, 1,2.4-cyclohexanetricarboxylic acid, 2,5.7-naphthalenetricarboxylic acid, 1.2.4-naphthalenetricarboxylic acid, 1.2.
4-butanetricarboxylic acid, 1.2.5-hexanetricarboxylic acid, 1.3-dicarboxy-2-methylcarboxypropene, 1.3-dicarboxy-2-methyl-2
-methylenecarboxypropane, tetra(methylenecarboxy)methane, 1,2,7.8-octanetetracarboxylic acid, embol trimer acid, acid anhydrides thereof, and others.

Specific examples of polyester resins particularly preferably used as the crystalline polymer in the present invention include polydecamethylene adipate, polydecamethylene azela-1, polydecamethylene adipate, polydecamethylene sebacate, and polydecamethylene adipate. Methylene succinate, polyethylene sebacate, polyethylene sebacate, polyethylene succinate, polyhexamethylene sebacate, polyhexamethylene sebacate, polyhexamethylene sebacate, polyhexamethylene succinate, and others to mention. I can do it.

Further, in the present invention, the resin preferably used as the amorphous polymer is a copolymer of styrene and an acrylic ester and/or a methacrylic ester, as described above, and specific examples of styrene include, for example. Styrene, 0-methylmethyl, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n -hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3. Examples include 4-dichlorostyrene.

Specific examples of acrylic esters or methacrylic esters include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, and lauryl acrylate. , acrylic M2-
Ethylhexyl, stearyl acrylate, acrylic acid 2
-Chlorethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate,
Isobutyl methacrylate, Mn-octyl methacrylate,
Dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate,
Examples include phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

The above crystalline polymer and amorphous polymer are preferably incompatible with each other. Here, "incompatibility" means
This refers to the fact that the chemical structures of the two are the same or R4O, or that the two are not sufficiently dispersed due to the action of functional groups, and the solubility parameter, e.g., s by Fedose's method, is
, p, value (R,F.

Fedors, Polym, Eng, Sci,...
14. (2) 147 (1974)) difference is 0.
It is larger than 5.

In the present invention, the polyolefin polymer is preferably polypropylene, polyethylene, or a modified product thereof, and has a softening point of 100 to 160°C.

The toner for electrostatic image development of the present invention has a coloring agent and properties added as necessary in a binder containing a specific crystalline polymer, an amorphous polymer, and a polyolefin polymer as described above. It contains an improving agent.

As a coloring agent, carbon black, nigrosine dye (
C, 1, No, 50415R), Aniline Blue (C,
LNo. 50405), Calco Oil Blue (C, T
, No, azoecBlue 3), Chrome Yellow (C, 1, No, +4090), Ultramarine Blue (C, r, No, 77103), DuPont Oil Red (C, [, No, 26105), Quinoline Yellow (C, 1, No. 47005), methylene blue chloride (C, 1, No. 52015), phthalocyanine blue (C, I.

No. 74160), malachite green off-salate (C, 1, No. 42000), lamp black (C
, 1, No. 77266) Rose Hengal (C, I, N
o, 45435), mixtures thereof, and others. These colorants need to be contained in a sufficient proportion to form a visible image of sufficient density, and are usually about 1 to 20 parts by weight per 100 parts by weight of the binder.

The binder may also contain other resins such as polyester, polyamide, polyurethane, styrene resin, etc. in an amount of 50% by weight or less.

〔Effect of the invention〕

As described above, the electrostatic image developing toner of the present invention has a melting point of 50
It contains a non-polyolefin crystalline polymer with a temperature of ~120°C, an amorphous polymer with a glass transition point of 50-80°C, and a polyolefin polymer, and the crystalline polymer has a melting point of 50°C. ~120°C, the softening point of the toner is low and the minimum fixing temperature Tf is low. For example, even with a heating roller whose temperature is set to a sufficiently low temperature, an image formed by the toner can be sufficiently fixed, and an amorphous Because the polyolefin polymer is contained in addition to the polyolefin polymer, the viscoelasticity of the molten toner becomes appropriate over a wide temperature range, resulting in excellent non-offset properties, low under-offset generation temperature Tu, and high hot-offset generation. Since the temperature Th is constant, an extremely wide fixable temperature range can be obtained, and therefore, suitable fixing performance can be easily obtained especially in high-speed image formation.

In addition, by using polyester resin as the crystalline polymer, good fluidity and good developability can be obtained, and by using incompatible crystalline polymers and amorphous polymers, The glass transition point of the binder does not drop significantly, and for this reason, the resulting toner has good blocking resistance, excellent storage stability, good fluidity, and great durability. .

As a result, excellent visible images can be stably formed using the toner of the present invention for developing electrostatic images.

[Examples] Examples of the present invention will be described in detail below, but the present invention is not limited to these Examples.

Examples and Comparative Examples Using the following combinations of crystalline polymers and amorphous polymers, 1.110 parts by weight of carbon blank [Mogal] was added to 100 parts by weight of the polymer components shown in Table 1, melted, kneaded, The mixture was pulverized and classified to produce l-ner for electrostatic image development with an average particle size of 11.0 μm. With respect to the obtained toner, experiments were conducted to determine the under-offset occurrence temperature T'h, the minimum fixing temperature 1°f, the fixable temperature range, the image quality and blocking resistance.

[Crystalline polymer]

A: Polyethylene sacchine-1 (melting point 95°C) B:
Polyethylene sacchine 1- (melting point 47°C) C:
Polypentamethylene lentileffle-1 (melting point 134"C
) [Amorphous polymer] D: Styrene/n-butyl acrylate (monomer ratio 8
5/15) Glass transition point Tg: 63°C Weight average molecular weight Mw: 93.000 Number average molecular weight Mn
; 10,500 Softening point Tsp: 132°C E: Styrene/n-butyl acrylate-1- (monomer ratio 70/30) Glass transition point Tg: 45°C Weight average molecular weight Mw: 34,000 Number average molecule 1Mn: 8 ,900 Softening point Tsp: 11
0°C [Polyolefin polymer] F: Polypropylene [Vysni I-J 660PJ
(manufactured by Sanyo Kasei) Softening point Tsp: 130°C In the experiment, each toner was mixed with a carrier made of iron powder coated with resin to prepare a developer with a toner concentration of 3% by weight, and each Due to the electrophotographic compound machine RL-
Using the old X4500J (Konishi Roku Photo 2 [manufactured by a certain company]), we conducted a live-photography test using the steps of developing an electrostatic charge image, transferring a toner image to transfer paper, and fixing the toner image with a heat roller fixing device, and found the minimum fixing temperature Tf. , the surface layer is Teflon (
A heat roller made of polytetrafluoroethylene (manufactured by DuPont) and a surface layer made of 'y+J Co-7 rubber IE-1
3001? A toner image of the sample toner was transferred onto a 64 g/m transfer paper using a fixing device consisting of a pressure roller formed by "TV" (manufactured by Shin-Etsu Chemical Co., Ltd.) at a linear velocity of 20.
The operation of fixing at a high speed of 0 mm/sec was repeated at each temperature in which the set temperature of the heat roller was raised stepwise by 5 degrees Celsius based on 100 degrees Celsius, and Kimwipe rubbing was applied to the formed fixed image. The lowest set temperature for a fixed image exhibiting sufficient abrasion resistance was defined as the lowest fixing temperature.

Note that the fixing device used here does not have a silicone oil supply mechanism.

In addition, to measure the under offset occurrence temperature Tu and the hot offset occurrence temperature Th, a toner image is transferred and fixed using the above-mentioned fixing device in accordance with the measurement of the minimum fixing temperature, and then a blank transfer paper is transferred in the same manner. repeating the operation of sending the toner to the fixing device under certain conditions and observing whether or not toner stains occur thereon while sequentially changing the set temperature of the heat roller of the fixing device within the range of 100 to 230°C; The temperature at which each offset phenomenon occurs was determined.

Furthermore, each toner was left in an atmosphere at a temperature of 55° C. and a humidity of 26% for 2 hours to examine whether blocking occurred.

The results are shown in Table 1.

From the results in Table 1, the toner for electrostatic image development according to the present invention (
According to Examples 1 to 4), it is clear that a very wide fixable temperature range can be obtained. However, Example 3
When the content of the crystalline polymer is outside the range of 5 to 40% by weight, the image properties tend to deteriorate slightly.

Further, from Comparative Example 1, a wide fixable temperature range cannot be obtained when a polyolefin polymer is not contained, and from Comparative Example 2, when a crystalline polymer is not contained, the minimum fixing temperature Tf becomes high. Comparative Example 3 shows that if the amorphous polymer is not contained, a fixable temperature range cannot be obtained due to the offset phenomenon, and Comparative Example 4 shows that the glass transition point of the amorphous polymer is outside a specific range. According to Comparative Example 5, the fixable temperature range narrows and the blocking resistance deteriorates when the polyolefin polymer content is 1.
If it exceeds 0% by weight, the image quality will deteriorate; from Comparative Example 6, when the melting point of the crystalline polymer is lower than 50°C, the fixable temperature range will be narrowed, and the image quality and blocking resistance will also deteriorate; From Comparative Example 7, the melting point of the crystalline polymer is 1
When the temperature is higher than 20°C, the fixing performance deteriorates and the fixable temperature range becomes narrow. From Comparative Example 8, when the content of crystals (Z1 polymer exceeds 50% by weight), the image quality deteriorates,
Alternatively, it is understood that as the non-offset property deteriorates, the fixable temperature range becomes narrower, and the blocking resistance also becomes slightly worse.

Claims (1)

[Claims] 1) The binder is a non-polyolefin crystalline polymer with a melting point of 50 to 120°C and a glass transition point of 50 to 80°C.
1. A toner for electrostatic image development, comprising an amorphous polymer and a polyolefin polymer.