JPH0544027B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an electrostatic image developing toner used for developing electrostatic latent images formed in electrophotography, electrostatic printing, electrostatic recording, etc. This invention relates to toner for developing electrostatic images. [Background of the Invention] For example, various electrophotographic methods are known (see US Pat. No. 2,297,691, etc.). Generally, an electrostatic latent image is formed by charging and exposing an electrostatic image carrier made of a photoconductive photoreceptor, and then this electrostatic latent image is transferred to a two-component developer made of toner and a carrier. It is developed with a one-component developer consisting only of toner containing a magnetic substance, and the resulting toner image is transferred to a support such as transfer paper and fixed by heating or pressure to form a visible image. Various methods have been used to fix toner images, and among them, a hot roller fixing method is preferred. This hot roller fixing method is a method of fixing the toner image on the support by transporting the support such as paper on which the toner image is carried so as to come into contact with a heated roller. This method is advantageous in terms of safety, and is also advantageous in terms of energy saving due to less heat loss. However, when a heat roller fixing method is adopted, the toner comes into contact with the surface of the heat roller in a molten state during the heat roller fixing process.
Conventional toner has high stickiness in its molten state, resulting in so-called offset, in which a portion of the molten toner transfers and adheres to the surface of the heated roller, and this transfers again to the next transfer paper, staining the image. A phenomenon occurs. Furthermore, in recent years, due to the demand for high-speed copying machines and miniaturization of copying machines, there has been a strong desire to develop toners that can be fixed at lower temperatures than conventional ones. In other words, in high-speed copying machines, when a large number of sheets are continuously copied, the heat of the heat roller is absorbed by the transfer paper, and the heat cannot be refilled in time.As a result, the temperature of the heat roller drops below the minimum fixing temperature at which toner can be fixed. This tends to cause poor fixing. In addition, in small-sized copying machines, it is necessary to reduce the capacity of the heater for heating the heat roller to make the machine more energy efficient and compact. As a result, the waiting time becomes long, or if continuous copying is performed, heat supply cannot be done in time, and as a result, the temperature of the heat roller decreases, which tends to cause fixing failure. Therefore, in order to solve these problems, there is a need for a toner that can be fixed at a lower temperature than conventional toners and has good offset resistance. [Problems to be solved by the invention] On the other hand, for example, Japanese Patent Publication No. 57-36586 discloses that a crystalline material having a melting point of 50 to 150°C and an activation energy for fluidization of 35 kcal/mol or less A technique for achieving low-temperature fixing by using a polymer as a toner binder has been disclosed, but when an image is formed using a hot roller fixing method using this toner, offset resistance is insufficient. There is a problem. Therefore, in order to prevent the occurrence of the offset phenomenon, it is necessary to provide means such as supplying oil to impart release properties to the surface of the heat roller, resulting in a problem that the apparatus becomes complicated. In addition, since this crystalline polymer is soft,
Uniform mixing of toner and carrier is difficult;
As a result, there is a problem in that the triboelectric charging properties of the toner become unstable and the image becomes unclear. Furthermore, there is a problem in that so-called toner filming occurs, in which the crystalline polymer constituting the toner is liberated and transferred and adheres to the carrier particles or the surface of the photoreceptor, which adversely affects image formation. Furthermore, there is a problem of low durability. On the other hand, (1) As a toner binder resin, the melting point is 45~
at least one crystalline polymer portion at 150°C;
Technology using a polymer formed by chemically linking an amorphous polymer portion with a glass transition point of 0°C or less (see Japanese Patent Application Laid-Open No. 1987-87032); (2) As a binder resin for toner, a polymer with a melting point of is 50~
A thermoplastic containing in its molecule a crystalline block at 70°C and an amorphous block whose glass transition point is at least 10°C higher than the melting point of the crystalline block, and the content of the crystalline block is 70 to 95% by weight. A technique using a polymer (see Japanese Patent Application Laid-open No. 59-3446) has been proposed. However, in the technology (1) above, the binder resin of the toner has a melting point of 45 to 150°C, which makes it a soft crystalline polymer at room temperature, and a glass transition point of 0°C or less, which makes it soft at room temperature. Because it is a copolymer that is chemically bonded to an amorphous polymer part that is sticky and soft, it is said that in an atmosphere at room temperature, toner aggregates in the developing device, a so-called blocking phenomenon. There is a problem. Furthermore, since the toner tends to aggregate in this way, the triboelectric charging properties between the toner and the carrier tend to be insufficient, and the fluidity of the developer is low, resulting in the problem of foggy and unclear images. be. Due to multiple copies, a so-called toner filming phenomenon occurs in which the carrier particles of the soft toner binder resin are transferred and adhered to the photoreceptor surface, and furthermore, the toner binder resin is fused to cleaning members such as a cleaning blade. This results in poor cleaning, resulting in fogging and, moreover, problems resulting in low-density, unclear images. In addition, because the binder resin of the toner is soft, in the pulverization process, which is one of the normal toner manufacturing processes, the toner tends to form lumps in the pulverizer when pulverized at room temperature, making pulverization difficult. However, there is a problem that a toner having a desired particle size cannot be obtained, resulting in a decrease in production efficiency and an increase in manufacturing cost. Furthermore, since the toner is highly sticky, there is a problem in that an offset phenomenon is likely to occur in a hot roller fixing device that does not have an oil supply mechanism. In addition, in the technique (2) above, since an amorphous block with a high glass transition point is used,
In order to obtain sufficient low-temperature fixability, the proportion of crystalline blocks used must be as high as 70 to 95% by weight, and moreover, the crystalline block must have a melting point lower than the glass transition point of the amorphous block. Therefore, the properties of the soft crystalline blocks that have plastic deformability at room temperature are reflected in the toner, and as a result, the triboelectricity between the toner and the carrier becomes insufficient, and the fluidity of the developer decreases. In the end, there is a problem that the image becomes unclear with a lot of fog. Also,
When image formation is performed multiple times, a so-called toner filming phenomenon occurs in which the binder resin of the toner transfers and adheres to carrier particles and the surface of the photoconductor, resulting in poor triboelectric charging properties and damage to cleaning blades, etc. There is a problem in that poor cleaning occurs due to the binder resin being fused to the cleaning member, resulting in an unclear image with a lot of fog and low density. Furthermore, in a fixing method that uses heating for a short time, such as a heat roller fixing device that does not apply a large amount of oil, the glass transition point of the above-mentioned amorphous block is high, so the temperature at which it can be fixed becomes high, and the crystalline block Since it is as high as ~95% by weight, offset phenomenon tends to occur. In this way, in the past, (1) sufficient low-temperature fixing properties, (2) excellent offset resistance, (3) excellent blocking resistance, (4) excellent filming resistance, and (5) excellent friction The reality is that a toner that satisfies all of the requirements of chargeability and (6) excellent durability has not yet been obtained. [Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and its objects are (1) sufficient low-temperature fixability; (2)
Heat roller fusing that satisfies all of the following conditions: excellent offset resistance, (3) excellent blocking resistance, (4) excellent filming resistance, (5) excellent triboelectric charging properties, and (6) excellent durability. An object of the present invention is to provide a toner for electrostatic image development. [Means for Solving the Problems] The electrostatic image developing toner for heat roller fixing of the present invention has a melting point of 50 to 120°C and a number average molecular weight of 1000 to 1000.
20000, weight average molecular weight is 2000-100000,
At least one selected from crystalline polyacrylic ester and crystalline polymethacrylic ester
A crystalline polymer with a hydroxyl group at the end, a glass transition point of 50 to 80°C, a number average molecular weight of 1000 to 50000, and a weight average molecular weight of 5000 to 150000.
An amorphous polymer selected from polyester and a styrene-acrylic copolymer having a hydroxyl group at the end is an essential component, and the crystalline polymer and the amorphous polymer are chemically bonded by an isocyanate coupling agent. Contains a block copolymer with a number average molecular weight of 1000 to 30000 and a weight average molecular weight of 5000 to 300000 as a binder, and further contains wax with a melting point of 50 to 150°C by 0.2 to 10% by weight based on the entire toner. %, the proportion of the crystalline polymer is 5 to 40% by weight based on the block copolymer, and the proportion of the amorphous polymer is 55 to 95% by weight based on the block copolymer. The melting point of the crystalline polymer is higher than the glass transition point of the amorphous polymer, and the crystalline polymer and the amorphous polymer are incompatible with each other. [Operations and Effects of the Invention] According to the electrostatic image developing toner for heat roller fixing of the present invention, firstly, the binder resin contained in the toner has a low melting point of 50 to 120°C and is a crystalline polyacrylic. Since at least one crystalline polymer selected from acid esters and crystalline polymethacrylic acid esters is an essential component, the toner melts quickly at a low temperature during hot roller fixing, resulting in excellent low-temperature properties. Second, since the resin contained in the toner has an amorphous polymer with a glass transition point of 50 to 80°C as an essential component, the toner becomes hard at room temperature and has a low temperature when melted. As a result, excellent offset resistance, excellent blocking resistance, excellent triboelectric charging properties, and excellent durability can be obtained. Thirdly, the resin contained in the toner is soft. Since the soft crystalline polymer and the hard amorphous polymer are chemically bonded, the soft crystalline polymer is strongly retained in the toner, and therefore the release of the crystalline polymer from the toner is suppressed. Therefore, excellent filming resistance can be obtained, and when a cleaning method using a blade is employed, the fusion of the resin of the toner to the blade is suppressed, and poor cleaning can be prevented. In addition, the block copolymer made of a crystalline polymer and an amorphous polymer as described above has good compatibility with the colorant, and therefore the colorant is uniformly dispersed and contained in the toner. As a result, it is possible to form an image with sufficient density without causing variations in image density. [Specific Structure of the Invention] The present invention will be described in detail below. The block copolymer contained as a binder in the toner of the present invention satisfies the following conditions. (1) It is a block copolymer formed by having a crystalline polymer and an amorphous polymer as essential components, and chemically bonding the crystalline polymer and the amorphous polymer with an isocyanate coupling agent. (2) The crystalline polymer has a melting point Tmp of 50 to 120.
℃, preferably 50 to 100℃, number average molecular weight is 1000 to 20000, and weight average molecular weight is 2000 to 2000.
Must be 100000. (3) The crystalline polymer is selected from crystalline polyacrylic esters and crystalline polymethacrylic esters, and has a hydroxyl group at its terminal. (4) The glass transition point Tg of the amorphous polymer is
50~80℃, number average molecular weight 1000~50000,
It must be selected from amorphous polyesters and amorphous styrene-acrylic copolymers having hydroxyl groups at their ends, with a weight average molecular weight of 5,000 to 150,000. If the block copolymer contained in the toner as a binder does not satisfy the above conditions (1) to (4), the toner's blocking resistance, offset resistance, fluidity, low temperature fixing property, triboelectric charging property, developability,
Filming resistance and durability decrease. More specifically, the melting point of the crystalline polymer
If Tmp is less than 50℃, the resulting toner will have poor blocking resistance, and the melting point
When Tmp exceeds 120° C., the resulting toner has reduced fluidity during melting at low temperatures, resulting in poor fixability. The glass transition point Tg of the amorphous polymer is 50℃
If it is less than 20%, the resulting toner will have poor fluidity, offset resistance, blocking resistance, filming resistance, and durability, and the glass transition point
If Tg exceeds 80°C, the low-temperature fixability of the resulting toner will deteriorate. It is necessary that the melting point Tmp of the crystalline polymer is higher than the glass transition point Tg of the amorphous polymer, and by selecting such conditions, even better offset resistance, blocking resistance, and filming resistance can be achieved. , liquidity can be obtained. Furthermore, it is necessary that the crystalline polymer and the amorphous polymer constituting the block copolymer are incompatible with each other, and by selecting such conditions, the resulting toner has no crystallization. The excellent properties of the amorphous polymer and the excellent properties of the amorphous polymer are clearly exhibited, and the toner has even more excellent properties such as fluidity and blocking resistance. Further, the crystalline polymer has a number average molecular weight Mn of 1,000 to 20,000, and a weight average molecular weight Mw of 2,000 to 100,000. By using a crystalline polymer having such a molecular weight, the resulting toner has excellent fluidity and low-temperature fixability. Further, the amorphous polymer has a number average molecular weight Mn of 1,000 to 50,000, and a weight average molecular weight Mw of 5,000 to 150,000. By using an amorphous polymer having such a molecular weight, the resulting toner has even better offset resistance, blocking resistance, and low-temperature fixability. The block copolymer contained as a binder in the toner of the present invention is a block copolymer having a crystalline polymer and an amorphous polymer having different physical properties as described above, and includes at least one crystalline polymer and at least one amorphous polymer. It is a block copolymer formed by chemically linking an amorphous polymer. The molecular weight of the block copolymer varies depending on the specific composition of the crystalline polymer and the amorphous polymer, their polymerization ratio, and other factors, but the number average molecular weight Mn is 1000 to 30000, and the weight average molecular weight Mw is 5000 to 300000. When the block copolymer has such a molecular weight, the toner has even better offset resistance and durability. The softening point Tsp of the block copolymer varies depending on the type of crystalline polymer and amorphous polymer constituting the block copolymer, and is not particularly limited in the present invention. It is preferable that Tsp is 70-150℃,
In particular, the temperature is preferably 90 to 140°C. By using a block copolymer having such a preferable softening point Tsp, the offset resistance of the toner can be improved.
Filming resistance and low-temperature fixing properties are even better. In addition, the glass transition point Tg of the block copolymer
is correlated with the glass transition point Tg of the amorphous polymer constituting the block copolymer, and if the crystalline polymer and the amorphous polymer are incompatible with each other, the glass transition point Tg of the block copolymer
Tg may be approximately equal to the glass transition point Tg of the amorphous polymer. The toner of the present invention contains the above-mentioned specific block copolymer as a binder, and the block copolymer is contained in an amount of at least 50% by weight based on the total amount of the toner. By setting such a preferable ratio, the excellent properties of the block copolymer can be reliably exhibited in the toner. The content ratio of the crystalline polymer constituting the block copolymer is 5 to 5% relative to the block copolymer.
It is said to be 40% by weight. By using such a proportion of crystalline polymer, better properties can be obtained in the toner. On the other hand, if the proportion of the crystalline polymer in the block copolymer is too small, the toner's low-temperature fixing properties may deteriorate, while if it is too large, the toner's triboelectric charging properties, offset resistance, fluidity, developability, and durability may deteriorate. performance may decrease. The content ratio of the amorphous polymer constituting the block copolymer is 55 to 50% of the block copolymer.
It is said to be 95% by weight. By using such a proportion of amorphous polymer, better properties can be obtained in the toner. On the other hand, if the proportion of the amorphous polymer in the block copolymer is too small, the toner's offset resistance, fluidity, and triboelectric charging properties may be reduced; on the other hand, if it is too large, the toner's low-temperature fixability may be reduced. be. The crystalline polymer constituting the block copolymer contained as a binder in the toner of the present invention is
A polymer in which at least a part of the polymer has a crystalline structure, including homopolymers or copolymers in which at least one component is crystalline, that is, partially crystalline, and exhibits a sharp and distinct melting point. In the solid state at a temperature below the melting point, it becomes cloudy due to crystallized parts. The fact that it is a crystalline polymer can be confirmed, for example, by measuring the X-ray diffraction intensity. Specifically, in the X-ray diffraction intensity curve, the diffraction intensity of the crystalline portion decreases as the temperature rises and becomes near the melting point. This can be confirmed by disappearing. The crystalline polymer used in the present invention is selected from crystalline polyacrylates and crystalline polymethacrylates and has a hydroxyl group at its terminal, and examples thereof include the following. Crystalline polyacrylate ester Γ Allyl polyacrylate (Tmp=90℃) Γ Isobutyl polyacrylate (Tmp=81℃) Γ Isopropyl polyacrylate
(Tmp=115℃) Crystalline polymethacrylic acid ester Γ Polytert-butyl methacrylate
(Tmp=104°C) The melting point Tmp of a crystalline polymer can be measured as follows. <Measurement of melting point Tmp of crystalline polymer> It can be measured according to differential scanning calorimetry (DSC), for example, using "DSC-20" (manufactured by Seiko Electronics Industries, Ltd.), and the measurement conditions are: 10 mg of sample is The melting peak value when heated at a temperature increase rate (10°C/min) is defined as the melting point Tmp. As mentioned above, the amorphous polymer used in the present invention has a glass transition point Tg of 50 to 80°C, and by using an amorphous polymer having such a glass transition point Tg, the amorphous polymer This allows the crystalline polymer to be strongly retained in the toner, resulting in good filming resistance, as well as high elasticity when melted, good releasability from the hot roller, and excellent offset resistance. It becomes something. The amorphous polymer that can be used in the present invention is, for example, an amorphous styrene-acrylic copolymer or an amorphous polyester having a hydroxyl group at the end. The amorphous styrene-acrylic copolymer can be obtained by polymerizing a styrene monomer and an acrylic monomer. Examples of the styrenic monomer and acrylic monomer include styrene, o-methylstyrene, p-
Methylstyrene, p-ethylstyrene, α-methylstyrene, 2,4-dimethylstyrene, p-
From styrenes and their derivatives such as tert-butylstyrene, p-n-octylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene. Selected styrenic monomers, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate , stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate , isobutyl methacrylate, tert-butyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.
- Acrylic monomers selected from methylene aliphatic monocarboxylic acid esters can be mentioned. Furthermore, in order to obtain a non-linear amorphous styrene-acrylic copolymer, in addition to the above monomers, a monomer having two or more polymerizable functional groups may be used for polymerization. Examples of such monomers having two or more polymerizable functional groups include divinylbenzene, divinylnaphthalene, derivatives thereof, and other aromatic divinyl compounds; ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate. , other carboxylic acid esters having a double bond; and others. Examples of nonlinear amorphous styrene-acrylic copolymers include styrene-n-butyl acrylate-divinylbenzene copolymer, styrene-n-butyl acrylate-methyl methacrylate-divinylbenzene copolymer, and styrene. -acrylic acid n-
Examples include butyl-ethylene glycol dimethacrylate copolymer. The amorphous polyester is obtained by polycondensation of a divalent or higher carboxylic acid monomer and a divalent or higher alcohol monomer. Examples of divalent carboxylic acid monomers include terephthalic acid, isophthalic acid,
Aromatic carboxylic acids such as phthalic acid and naphthalene dicarboxylic acid; aromatic oxycarboxylic acids such as p-(2-hydroxyethoxy)benzoic acid; succinic acid, fumaric acid, adivic acid, maleic acid, sebacic acid, decamethylene dicarboxylic acid, Aliphatic polycarboxylic acids such as mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, and malonic acid; fats such as 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, hexahydrophthalic acid, and tetrahydrophthalic acid. Examples include cyclic polycarboxylic acids; anhydrides of these acids; dimers of lower alkyl esters and linoleic acid; and other divalent organic acid monomers. In addition, examples of dihydric alcohol monomers include ethylene glycol, diethylene glycol,
triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,
4-butanediol, neopentyl glycol,
Diols such as 1,4-butenediol; 1,4
-Bis(hydroxymethyl)cyclohexane; etherified bisphenols such as bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropylenated bisphenol A; other dihydric alcohol monomers can be mentioned. Furthermore, in order to obtain a non-linear amorphous polyester, a polyvalent monomer of trivalent or higher valence may be used in addition to the above-mentioned divalent monomer. Examples of such trihydric or higher polyhydric alcohol monomers include sorbitol, 1,2,3,6-hexanetetrol, 1,
4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol,
Sucrose, 1,2,4-butanetriol, 1,2,
5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,
4-butanetriol, trimethylolethane,
Trimethylolpropane, 1,3,5-trihydroxymethylbenzene, and others can be mentioned. In addition, examples of trivalent or higher polycarboxylic acid monomers include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic 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-dicarboxyl-2-
Methyl-2-methylenecarboxylpropane, tetra(methylenecarboxyl)methane, 1,2,
Examples include 7,8-octane tetracarboxylic acid, empol trimer acid, acid anhydrides thereof, lower alkyl esters thereof, and others. The proportion of the polyvalent monomer of trivalent or higher valence as described above may be 0.1 to 80 mol% in each of the alcohol component or acid component as a structural unit in the nonlinear amorphous polyester. preferable. As mentioned above, the block copolymer contained as a binder in the toner of the present invention is a block copolymer formed by chemically bonding a crystalline polymer and an amorphous polymer as essential components with an isocyanate coupling agent. , and crystalline polymers and amorphous polymers are mutually incompatible. This chemical bond is preferably a covalent bond, and its bond energy is preferably 5 kcal/mole or more. Incompatibility here means a system that exhibits an opaque state when both polymers are melt-mixed and then cooled to a solid state. A specific means for obtaining a block copolymer formed by chemically bonding the crystalline polymer and the amorphous polymer as essential components is to attach the terminal functional group of each polymer to at least a difunctional isocyanate coupling agent. It means to join together. Specifically, a block copolymer can be obtained by a urethane bond formed by a reaction between a polymer whose terminal group is a hydroxyl group and a diisocyanate. Specific examples of the coupling agent include isocyanate coupling agents such as hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, tolidine diisocyanate, naphthylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate. The proportion of these coupling agents used is preferably 1 to 10% by weight based on the total weight of the crystalline polymer and the amorphous polymer, particularly 2% by weight.
Preferably it is 7% by weight. The content of the block copolymer in the toner is preferably 1 to 95% by weight, particularly preferably 5 to 95% by weight, based on the total toner. If the content of the block copolymer is too small, the low-temperature fixability may deteriorate, and the dispersibility of the colorant may deteriorate, resulting in density unevenness in the image. Furthermore, the block copolymer contained as a binder in the toner of the present invention does not necessarily have to be strictly one in which all crystalline polymers and amorphous polymers are chemically bonded; It suffices if it is connected to The resin constituting the binder of the toner of the present invention may be composed only of the above block copolymer, or may be a mixture thereof with other resins. When other resins are used together in this way, the content ratio of the block copolymer to the entire binder should be 5 to 5.
It is preferably 100% by weight. Examples of such other resins include styrene-acrylic copolymers, polyesters, polyamides, polyurethanes, and epoxy resins. The toner of the present invention basically contains a block copolymer as described above as a binder, a specific wax as described below in a specific proportion, and further contains a colorant or other toner components as necessary. These are powder particles containing Other toner components include, for example, a magnetic material, an offset prevention aid, a fixability improving aid, a fluidity improver, an abrasive, a charge control agent, etc. These toner components are mixed and dispersed in a binder. It may be contained in a state in which it is present, or it may be contained in a state in which it is adhered to or implanted on the surface of toner particles. Examples of the coloring agent include carbon black, nigrosine dye (CI No. 50415 B), aniline blue (CI No. 50405), calco oil blue (CI No. azoic Blue 3), and chrome yellow (CI No.
No.14090), Ultramarine Blue (CINo.
77103), DuPont Oil Red (CINo.26105),
Quinoline Yellow (CI No. 47005), Methylene Blue Chloride (CI No. 52015), Phthalocyanine Blue (CI No. 74160), Malachite Green Oxalate (CI No. 42000), Lamp Black (CI No.
77266), Rose Bengal (CI No. 45435), mixtures thereof, and others. The content of these colorants is preferably about 1 to 20 parts by weight per 100 parts by weight of the toner. Further, some of the magnetic materials described below have a function as a coloring agent, and when obtaining a magnetic toner, these colored magnetic materials may be used as a coloring agent. The magnetic material may be a metal or alloy exhibiting ferromagnetism such as ferrite, magnetite, iron, cobalt, or nickel, or a compound containing these elements, or a material that does not contain a ferromagnetic element but is subjected to appropriate heat treatment. Mention may be made of alloys which thus become ferromagnetic, such as alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, or chromium dioxide, among others. It is preferable that these magnetic substances are uniformly dispersed and contained in the binder in the form of fine powder having an average particle size of 0.1 to 1 μm. The content of the magnetic material is preferably 20 to 70 parts by weight, particularly preferably 25 to 50 parts by weight, based on 100 parts by weight of the toner. The wax has the function of an offset prevention aid or a fixability improving aid. This wax has a melting point of 50 to 150°C. Specifically, liquid or solid paraffins, polyolefins such as polyethylene or polypropylene, fatty acid metal salts, fatty acid esters, partially saponified fatty acid esters, higher fatty acids, higher alcohols, silicone varnishes, amide waxes, aliphatic fluorocarbons, and their Examples include modified products. Further, the content ratio of these is 0.2 to 10% by weight based on the entire toner. By using such a wax as a component of a toner, the properties of the toner become even more excellent. For example, in a heat roller fixing system, a cleaning roller is usually placed in opposition to the heat roller to remove stains caused by toner substances generated on the surface of the heat roller. By containing the toner, transfer and adhesion of the toner substance to the heat roller can be more effectively prevented, resulting in the advantage that the service life of the cleaning roller and the heat roller can be extended. As the fluidity improver or abrasive, for example, inorganic fine particles or other fine particles can be used, and the primary particle diameter thereof is preferably 5 mμ to 2 μm, particularly preferably 5 mμ to 500 mμ. Also, the specific surface area by BET method is 20 ~
Fine particles of 500 m ² /g are preferred. The content ratio of these fine particles to the whole toner is, for example,
It is preferably 0.01 to 5% by weight, especially 0.1% by weight.
Preferably it is ~2.0% by weight. These fine particles are preferably contained by being adhered to or implanted onto the surface of the toner particles. in particular,
For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony oxide, magnesium oxide, zirconium oxide,
barium sulfate, barium carbonate, calcium carbonate,
Fine particles of silicon carbide, silicon nitride, etc. can be used. Among these, silica fine particles can be particularly preferably used. The silica fine particles are fine particles having the following bonding structure, and may be produced by either a dry method or a wet method. In addition to anhydrous silicon dioxide, silica may be in any form such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, and zinc _silicate .
Preferably, it contains 85% by weight or more. There are various kinds of silica fine particles commercially available, and among them, those having a hydrophobic group on the surface can be preferably used. Examples of such commercially available products include "Aerosil R-972", "Aerosil R-974", "Aerosil R-805", "Aerosil R-812" (manufactured by Nippon Aerosil Co., Ltd.), and "Taranox 500" ( (manufactured by Talco), etc. In addition, silica fine particles surface-treated with a silane coupling agent, a titanium coupling agent, a silicone oil, a silicone oil having an amine in its side chain, etc. can also be effectively used. The charge control agent is not particularly limited, and any known substance can be used. Examples of negatively chargeable materials include JP-A-57-141452 and JP-A-Sho.
58-7645, JP 58-111049, JP 58-185653, JP 57-167033,
2:1 disclosed in Special Publication No. 44-6397 etc.
type metal-containing azo dye; for example, JP-A-57-104940, JP-A-57-111541, JP-A-57-124357
metal complexes of aromatic oxycarboxylic acids and aromatic dicarboxylic acids disclosed in Japanese Patent Application Laid-Open No. 53-127726; for example, copper phthalocyanine dyes disclosed in Japanese Patent Application Laid-open No. 52-45931; Examples include sulfonylamine derivatives or sulfonamide derivative dyes of copper phthalocyanine, sulfonamide and sulfonic acid or sulfonate derivative dyes of copper phthalocyanine, and the like. In addition, as a positively charged one, for example, JP-A-49
- Quaternary ammonium compounds disclosed in JP-A-51951, JP-A-52-10141, etc.; For example, JP-A-56-11461, JP-A-54-158932,
Alkylpyridinium compounds and alkylpicolinium compounds disclosed in U.S. Pat. No. 4,254,205, etc.; for example, nigrosine SO, nigrosine
Nigrosine dyes such as EX; e.g.
Examples include addition condensates disclosed in Japanese Patent No. 80320. The content ratio of these charge control agents is preferably 0.1 to 10% by weight based on the entire toner.
In particular, it is preferably 0.3 to 5% by weight. Further, the toner of the present invention has a softening point Tsp of 90 to
The temperature is preferably 150°C, particularly preferably 100 to 140°C. If the softening point Tsp is too small, the offset resistance may deteriorate, while if it is too large, the low-temperature fixability may become poor. Here, the softening point Tsp is the flow tester "CFT
-500'' (manufactured by Shimadzu Corporation), the measurement conditions were: load 20Kg/cm ² , nozzle diameter 1mm, nozzle length 1mm, preheating time at 50℃ for 10 minutes, temperature increase rate 6
℃/min, sample amount 1.0cm ³ (true specific gravity x 1cm ³
The temperature is h/2 when the height of the S-curve in the flow tester's plunger drop-temperature curve (softening flow curve) is h/2 when measuring and recording the weight expressed by . Further, in the present invention, the glass transition point Tg can be measured as follows. <Measurement of glass transition point Tg> It can be measured according to differential scanning calorimetry (DSC) using, for example, "DSC-20" (manufactured by Seiko Electronics Industries, Ltd.). Specifically, approximately 10 mg of a sample is The glass transition point Tg is obtained from the intersection of the baseline and the slope of the endothermic peak. Also, weight average molecular weight Mw and number average molecular weight
The value of Mn can be determined by various methods, and there are some differences depending on the measurement method, but in the present invention, it is defined as being determined according to the measurement method below. That is, the weight average molecular weight Mw and number average molecular weight Mn are measured by gel permeation chromatography (GPC) under the conditions described below. At a temperature of 40℃, the solvent (tetrahydrofuran) was flowed at a flow rate of 1.2ml per minute, and the concentration was 0.2g/min.
Measurement is performed by injecting 20 ml of tetrahydrofuran sample solution to a sample weight of 3 mg. When measuring the molecular weight of a sample, the measurement conditions are such that the molecular weight of the sample falls within the range where the logarithm of the molecular weight and the count number of a calibration curve prepared using several types of monodisperse polystyrene standard samples are linear. select. The reliability of the measurement results can be confirmed by the fact that the weight average molecular weight Mw = 28.8 x 10 ⁴ and the number average molecular weight Mn = 13.7 x 10 ⁴ for the NBS706 polystyrene standard sample measured under the above measurement conditions. Moreover, any column may be used as the GPC column as long as it satisfies the above conditions. Specifically, for example, TSK-
GEL, GMH ₆ (manufactured by Toyo Soda Co., Ltd.), etc. can be used. Note that the solvent and measurement temperature are not limited to the conditions described, and may be changed to appropriate conditions. The toner of the present invention can be manufactured, for example, by the following method. That is, a coloring agent is added to a specific block copolymer as described above and wax or other resin used as a binder, and further, other toner components are added as necessary, and these are mixed, for example. Toner powder with a desired particle size can be obtained by melting and kneading with an extruder, cooling, pulverizing with a jet mill or the like, and then classifying. Further, by further adding and mixing other toner components to this toner powder, a toner with improved characteristics can be obtained. As another method, a toner having a desired particle size can be obtained by melting and kneading the toner using an extruder and then spraying it in a molten state using a spray dryer or dispersing it in a liquid. The electrostatic image developing toner of the present invention is a toner for heat roller fixation, and is used for image formation, for example, in the following manner. That is, in electrophotography, an electrostatic latent image formed on a photoreceptor, which is a latent image carrier, is developed with a developer made of the toner according to the present invention, and the resulting toner image is transferred to paper. For example, the transferred toner is electrostatically transferred onto a transfer material made of, for example, and then fixed by a hot roller fixing method to form a visible image. The heat roller fixing device used in the heat roller fixing method usually consists of a heat roller, a contact roller placed opposite the heat roller, and a heat source. By passing the support to which the toner has been transferred between the pair of rollers while maintaining the heat roller, the toner is brought into direct contact with the heat roller and is thermally fixed to the support. The toner of the present invention particularly comprises a toner on a support,
Contact time with heat roller is within 1 second, preferably 0.5
It exhibits a significantly superior effect compared to conventional toners when fixing is performed at high speeds within seconds. [Specific Examples] Specific examples of the present invention will be described below, but the present invention is not limited to these examples. <Example 1> 35 parts by weight of crystalline polymer A shown in Table 1 below and 65 parts by weight of amorphous polymer C shown in Table 2 below were coupled with a coupling agent (hexamethylene diisocyanate). Block copolymer 1 for use in the present invention shown in Table 3 below was obtained. Next, 100 parts by weight of this block copolymer 1, 10 parts by weight of carbon black "Mogal L" (manufactured by Cabot Corporation), and 3 parts by weight of polypropylene "Viscol 660P" (manufactured by Sanyo Chemical Industries, Ltd.),
2 parts by weight of "Wax-E" (manufactured by Hoechst) and 2 parts by weight of charge control agent "Bontron E-81" (manufactured by Orient Chemical Co., Ltd.) were mixed, kneaded with heated rolls, cooled, and coarsely crushed. Colored fine particles were obtained by further pulverizing with an ultra-high-speed jet mill and then classifying with an air classifier. To 100 parts by weight of the colored fine particles, 0.8 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added, and these were mixed in a V-type mixer to obtain a volume average particle size of is 11.0μm
Toner 1 of the present invention was obtained. Table 3 also shows the types of crystalline polymers and amorphous polymers used to produce the block copolymers and their blending weight ratios. In addition, in Table 3, the crystalline polymers shown by A to E and their melting points Tmp are as shown in Table 1, and the amorphous polymers shown by a to d and their glass transition points Tg are shown in Table 2. As shown in Next, toner 1-3 obtained as above
A developer was prepared by mixing 97 parts by weight of a resin-coated carrier coated with a styrene-methyl methacrylate copolymer resin and having an average particle size of 100 μm. Using this developer, the electrophotographic copying machine "U-
Bix5000 (manufactured by Konishiroku Photo Industry Co., Ltd.) to form and develop an electrostatic latent image, and the resulting toner image was transferred onto transfer paper and fixed by a heated roller fixing device to form a copy image. The minimum fixing temperature (minimum temperature of the heat roller capable of fixing) and offset occurrence temperature (minimum temperature at which offset development occurs) were measured by the following method, and the fixable temperature range was also determined. Minimum fixing temperature After creating an unfixed image using the above copying machine, a 50φ heat roller whose surface layer is made of Teflon (polytetrafluoroethylene manufactured by Dupont) and a silicone rubber surface layer "KE-1300RTV" (Shin-Etsu Chemical Co., Ltd.) are used. A toner image made of the sample toner was transferred onto a 64 g/m ² transfer paper using a hot roller fixing device consisting of a pressure roller (manufactured by A.D. Co., Ltd.) at a linear speed of 210 mm/sec and a linear pressure of 0.8 kg/m2. cm, nip width 8.0
The fixing operation is performed in mm, and the set temperature of the heat roller is
Raise the temperature in steps of 5 degrees Celsius within the range of 80 to 230 degrees Celsius, repeat at each temperature, apply Kimwipe rubbing to the formed fixed image, and set the lowest setting for a fixed image that shows sufficient scratch resistance. The temperature was defined as the minimum fixing temperature. Note that the heat roller fixing device used here does not have a silicone oil supply mechanism. Offset Occurrence Temperature The offset occurrence temperature is measured in accordance with the measurement of the above-mentioned minimum fixing temperature, but after an unfixed image is created in the above-mentioned copying machine, the toner image is transferred and fixed by the above-mentioned heat roller fixing device. Next, a blank transfer sheet is sent to the heat roller fixing device under the same conditions and visually observed to see whether toner stains occur on it, and the set temperature of the heat roller of the heat roller fixing device is sequentially increased. This was repeated in this state, and the lowest set temperature at which toner staining occurred was taken as the offset generation temperature. Fixable Temperature Range The difference between the offset occurrence temperature and the minimum fixing temperature measured as described above was defined as the fixable temperature range. The above results are shown in Table 4. Furthermore, Toner 1's blocking resistance, filming resistance, cleaning performance, charge amount (Q/M),
The fluidity of the developer prepared using Toner 1 was measured as follows. Blocking Resistance The toner is left under the environmental conditions of a temperature of 45°C and a relative humidity of 43% for 2 hours, and judgment is made based on whether or not agglomerates form in the toner. If no agglomerates are observed, it is evaluated as " The case where an agglomerate was observed was marked as "x". Filming resistance Observe the surface of the carrier particles and the surface of the photoreceptor, and judge by the presence or absence of deposits on the surface. If no deposits are observed, it is marked as "○", and if any deposits are observed, it is marked as " ×”. Cleanability After cleaning the surface of the photoreceptor with a cleaning member, the surface of the photoreceptor is observed and judged based on the presence or absence of deposits on the surface.If no deposits are observed, it is marked as "○". The case was marked as “×”. Fluidity of developer Visually observe the developer in the developing device. If the fluidity is good, it is marked as "○", and if it is not good, but at a practical level, it is marked as "△". Items with problems were marked with an "x". Charge amount (Q/M) Measured by the known blow-off method, 1g of toner
The value of the amount of triboelectric charge per charge was defined as the amount of charge (Q/M). The above results are also shown in Table 4. Further, the fog and sharpness of the copied images obtained by the actual copying test using the above-mentioned copying machine were evaluated as follows. Fog Fog was determined by measuring the relative density of the developed image of a white background area with an original density of 0.0 using a Sakura densitometer (manufactured by Konishiroku Photo Industry Co., Ltd.). Note that the white background reflection density was set to 0.0. The evaluation is ``○'' if the relative concentration is less than 0.01, and 0.03 if it is 0.01 or more.
Those less than 0.03 were marked "△" and those 0.03 or more were marked "x". Sharpness Using the line drawing chart of the manuscript as the original, its reproducibility was enlarged and judged based on visual angle. The evaluation was rated "○" if it was good, "△" if it was not good but at a practical level, and "x" if it was inferior and had problems in practical use. The above results are also shown in Table 4. Furthermore, the durability of the toner was examined by continuously repeating the photocopying test using the above-mentioned copying machine. That is, after the image forming process is continuously repeated 30,000 times by the above-mentioned copying machine, the toner charge amount (Q/M), developer fluidity, filming resistance, cleaning performance, fogging and sharpness of the copied image are evaluated. The properties were measured and evaluated in the same manner as above. Furthermore, the presence or absence of dirt on the heat roller in the heat roller fixing device was examined by the following method. Dirt on the heat roller After forming copied images 30,000 times, instead of directly observing the dirt on the surface of the heat roller, we inspected the surface of the cleaning roller placed in opposition to clean the surface of the heat roller. The presence or absence of dirt was visually observed and evaluated. Those in good condition with no dirt observed are marked as "○", those that are not in good condition but at a practical level are marked as "△", and those with a lot of dirt and problems in practical use are marked as "×". . The above results are shown in Table 5. <Examples 2 and 3> In the formation of the block copolymer of Example 1,
Block copolymers 2 and 3 were obtained in the same manner as in Example 1, except that the types and blending ratios of the crystalline polymer and amorphous polymer were changed as shown in Table 3. The toners 2 and 3 of the present invention were then treated in the same manner as in Example 1 to obtain toners 2 and 3 of the present invention. Developers were prepared using these toners 2 and 3 in the same manner as in Example 1, and then a photographic test was conducted and various properties were evaluated in the same manner as in Example 1. The results are also shown in Tables 4 and 5. <Example 4> In the production of toner in Example 1, polypropylene "Viscol 660P" and "Wax-
Toner 4 of the present invention was obtained in the same manner as in Example 1 except that "E" was not used. A developer was prepared using this toner 4 in the same manner as in Example 1, and then an actual photographic test was conducted and various characteristics were evaluated in the same manner as in Example 1. The results are also shown in Tables 4 and 5. <Comparative Example 1> In the formation of the block copolymer of Example 1,
Comparative block copolymer 4 was obtained in the same manner as in Example 1, except that the types and blending ratios of the crystalline polymer and amorphous polymer were changed as shown in Table 3. Example 1 Using 100 parts by weight of this block copolymer 4, 10 parts by weight of carbon black "Mogal L", and 3 parts by weight of charge control agent "Bontron E-81"
Colored fine particles were obtained by processing in the same manner as in Example 1, and Comparative Toner 1 was obtained by processing in the same manner as in Example 1 using the colored fine particles. A developer was prepared using this Comparative Toner 1 in the same manner as in Example 1, and then an actual photographic test was conducted and various properties were evaluated in the same manner as in Example 1. The results are also shown in Tables 4 and 5. <Comparative Examples 2 and 3> In the formation of the block copolymer of Example 1,
Comparative block copolymers 5 and 6 were obtained in the same manner as in Example 1, except that the types and blending ratios of the crystalline polymer and amorphous polymer were changed as shown in Table 3. These comparative block copolymers 5 and 6
Comparative toner 2 was processed in the same manner as in Example 1 using
and 3 were obtained. Developers were prepared in the same manner as in Example 1 using these comparative toners 2 and 3, and then a photographic test was conducted and various properties were evaluated in the same manner as in Example 1. The results are also shown in Tables 4 and 5. Note that the above toners 1 to 4 and comparative toners 1 to 4
When the softening point Tsp of Toner 3 was measured using a flow tester, Toner 1 was 122°C, Toner 2 was 116°C, Toner 3 was 127°C, Toner 4 was 132°C, and Comparative Toner 1
is 83℃, comparison toner 2 is 154℃, comparison toner 3 is
It was 78℃.

【table】

【table】

【table】

【table】

【table】

[Table] As understood from the results in Tables 4 and 5, toners 1 to 4 of the present invention all have low-temperature fixing properties, offset resistance, blocking resistance, fluidity, triboelectric charging properties, It has excellent filming resistance, cleanability, and durability, and can stably form clear images without fog over a long period of time. On the other hand, comparative toners 1 and 3 have poor offset resistance and a narrow fixable temperature range, and also have poor blocking resistance and exhibit toner filming after 30,000 image formations. occurred, resulting in poor cleaning. Furthermore, the developers prepared using these comparative toners 1 and 3 had poor fluidity and triboelectric charging properties, and as a result, the copied images were foggy and unclear even in the early stages of image formation. Furthermore, after 30,000 times of image formation, the amount of charge on the toner decreased significantly, and as a result, the copied image had a significant amount of fog and became unclear with low image density. On the other hand, Comparative Toner 2 has extremely low low-temperature fixability, and therefore has a narrow fixable temperature range, and when image formation is continuously repeated many times, fixing failure may occur due to a drop in the temperature of the heat roller. In the end, it is inconvenient for high-speed fixing.

Claims (1)

[Claims] 1. Melting point is 50-120°C, number average molecular weight is 1000-1000.
20000, weight average molecular weight is 2000-100000,
At least one selected from crystalline polyacrylic ester and crystalline polymethacrylic ester
A crystalline polymer with a hydroxyl group at the end, a glass transition point of 50 to 80°C, a number average molecular weight of 1000 to 50000, and a weight average molecular weight of 5000 to 150000.
An amorphous polymer selected from polyester and a styrene-acrylic copolymer having a hydroxyl group at the end is an essential component, and the crystalline polymer and the amorphous polymer are chemically bonded by an isocyanate coupling agent. A block copolymer with a number average molecular weight of 1,000 to 30,000 and a weight average molecular weight of 5,000 to 300,000 is contained as a binder, and 0.2 to 10% of the weight of wax with a melting point of 50 to 150°C is added to the entire toner. %, the proportion of the crystalline polymer is 5 to 40% by weight based on the block copolymer, and the proportion of the amorphous polymer is 55 to 95% by weight based on the block copolymer. A toner for electrostatic image development for heat roller fixing, wherein the crystalline polymer has a melting point higher than the glass transition point of the amorphous polymer, and the crystalline polymer and the amorphous polymer are incompatible with each other.