JPH0769634B2 - Toner for electrostatic image development - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention develops an electrostatic latent image formed on the surface of a latent image carrier in, for example, electrophotography, electrostatic printing, electrostatic recording, or the like. The present invention relates to an electrostatic image developing toner used for this purpose.

[Background of technology]

For example, in electrophotography, an electrostatic latent image is usually formed on a latent electrostatic image bearing member made of a photoconductive photoconductor by charging and exposure, and then this electrostatic latent image is formed by toner, which is a colored particle. After development, the obtained toner image is usually transferred to a recording material such as paper and then fixed to form a visible image.

As a method for fixing the toner image, conventionally, a method of heating and melting the toner in a non-contact state with a heater to fix the toner,
Known methods include a method of dissolving and fixing the toner with an organic solvent, a method of fixing the toner by applying pressure, and a so-called heating roller fixing method of directly contacting the heating roller with the toner to melt and pressure-fix the toner. The heating roller fixing method is preferable from the viewpoint of high thermal efficiency and high-speed fixing.

However, recently, (a) suppressing deterioration of the copying machine due to overheating, and (b) shortening the warm-up time required to raise the temperature of the heating roller to a fixing possible temperature after operating the heating roller fixing device. (C) To reduce the temperature drop of the heating roller due to heat being absorbed by the recording material such as paper to enable stable image formation for a number of times in succession. From the viewpoints of downsizing and improvement of safety, there is a strong demand for reducing the power consumption of the heater incorporated in the fixing device to enable the fixing process with the temperature of the heating roller being lowered.

Therefore, the toner is required to be able to achieve good fixing at a temperature lower than (1), that is, to have an excellent low-temperature fixing property, and basically, the following conditions are required. is necessary.

(2) In the heating roller fixing method which is preferable as the fixing method, an offset phenomenon, that is, a part of the toner forming the image at the time of fixing is transferred to the surface of the heating roller and retransferred to the recording material sent next. Since the phenomenon of smearing the image is likely to occur, it is necessary to impart the toner with a property that does not easily transfer to the heating roller, that is, offset resistance.

(3) It can exist stably as a powder without aggregation under the conditions of use or storage environment, that is, it has excellent storage stability.

(4) The fluidity is good and the developability is excellent.

(5) The occurrence of so-called filming phenomenon in which the toner substance adheres to the surface of the latent image carrier or the surface of the carrier particles is suppressed, and an image with good image quality can be stably formed many times, that is, excellent durability is achieved. That

[Conventional technology]

Therefore, the following techniques have been conventionally proposed.

As a toner resin, a technique is used in which a crystalline portion having a melting point Tm of 45 to 150 ° C. and an amorphous portion having a glass transition point Tg of 0 ° C. or less are chemically bonded (Japanese Patent Laid-Open No. 50-87032). (See the official gazette).

As a toner resin, a crystalline portion having a melting point Tm of 45 to 90 ° C. and an amorphous portion having a glass transition point Tg at a temperature 10 ° C. or higher higher than the melting point Tm of the crystalline portion are chemically bonded. Technology using a different resin (see Japanese Patent Laid-Open No. 59-3446).

A technique of using a graft polymer of a vinyl polymer and a crystalline polymer obtained from ethylene, propylene and vinyl acetate as a toner resin (see JP-A-56-154740).

A technique of using a graft polymer of a crystalline polymer obtained from ethylene, propylene, vinyl acetate, an unsaturated polyester, and a vinyl polymer as a toner resin (see JP-A-57-8549).

As the toner resin, a block copolymer or graft copolymer of a hard component and a soft component, an amorphous resin having a glass transition point Tg of 50 ° C. or higher and having compatibility with the hard component, and a melting point Tm of 60. A technique of using a mixture of the above-mentioned hard component and an incompatible crystalline resin at a temperature of not less than 0 ° C (see JP-A-57-32447).

As a toner resin, a graft copolymer obtained by graft-polymerizing a vinyl-based polymer to a crystalline polymer obtained from ethylene, propylene, or vinyl acetate, and a monomer which is common to the monomer of the graft copolymer. Of using a mixture of a cross-linked polymer obtained by copolymerizing a vinyl-based monomer containing a majority of the polymer and a divinyl-based monomer (JP-A-60-263).
953 gazette).

As the toner resin, the surface tension γ _s of one of the polymer forming the main chain and the polymer forming the side chain is 3
A technique using a graft polymer having a surface tension γ _s of 4 or more and the other polymer of less than 34 (see JP-A-59-135478).

[Problems to be solved by the invention]

However, in the above technologies or, (1) low temperature fixing property, (2) offset resistance, (3) storage property,
It is still difficult to obtain a toner that is sufficiently satisfactory in all aspects of (4) developability and (5) durability.

That is, in the above technique, since the toner resin has high adhesiveness, the storage stability is poor even at room temperature, an offset phenomenon is likely to occur during fixing, and the developability is poor due to poor fluidity. Since the filming phenomenon occurs at an early stage, the durability is poor, and the image obtained as a result of these is unclear with a lot of fog.

In the above technique, since the toner resin is soft, the fluidity is poor and the developability is poor, and at the time of fixing, an offset phenomenon is likely to occur, and a filming phenomenon occurs early so that durability is poor. However, the image obtained as a result of these becomes blurred with a lot of fog.

According to the above techniques and, the developability is poor due to poor fluidity, and the resulting image is unclear including image missing.

In the above-mentioned technique, since the toner is for pressure fixing, the hot roller fixing method has a significant problem of occurrence of an offset phenomenon.

In the above technique, since the releasing property at low temperature is poor, so-called under-offset resistance is poor, and it is difficult to obtain a stable image for a long period of time.

On the other hand, in order to improve low-temperature fixability, anti-offset property, and storage stability, a technique using a resin obtained by reacting a polymer having a carboxyl group with a metal compound as a toner resin (JP-A-57 -178250, JP-A-61-110155, JP-A-61-110156).

However, with this technique, the hot offset resistance and storage stability are good, but the under-offset resistance is poor because the mold releasability and fixability at low temperatures are poor.

The present invention has been made based on the above circumstances and includes (1) low temperature fixing property, (2) offset resistance,
(3) Storability, (4) developability, and (5) durability of the toner are all satisfactory.

[Means for solving problems]

The electrostatic image developing toner of the present invention comprises a crystalline polyester and a ratio Mw / M of the weight average molecular weight Mw to the number average molecular weight Mn.
It is characterized by containing a block copolymer or a graft copolymer chemically bonded to an ionically cross-linked amorphous vinyl polymer having a value of n of 3.5 or more.

[Advantageous effects of the invention]

The electrostatic image developing toner of the present invention contains a block copolymer or a graft copolymer in which a crystalline polyester and a specific ionically cross-linked amorphous vinyl polymer are chemically bonded. Therefore, (1) low temperature fixability,
(2) Offset resistance, (3) Storage property, (4) Developability,
(5) Excellent effects are exhibited in all aspects of durability. Therefore, according to the toner of the present invention, it is possible to perform good heat fixing at a lower temperature, and it is possible to stably form a clear image without fog many times.

That is, the ion-crosslinked amorphous vinyl polymer having a ratio Mw / Mn value of 3.5 or more has a tough property in a state where a strong crosslinkage is formed under non-heating,
Therefore, the effect of suppressing the development of tackiness possessed by the crystalline polyester is remarkably large, and as a result, the effect of improving storage stability, fluidity, and filming resistance is exhibited, and under heating by heat fixing, there is no ionic cross-linking. The vinyl chloride polymer exhibits an appropriate effect of improving offset resistance by viscoelasticity, and the ionic cross-linking bond of the amorphous vinyl polymer has a smaller bonding force than a covalent bond and is easily broken by heating, and also has crystallinity. Excellent low-temperature fixability is exhibited by the synergistic effect of the good low-temperature melting property of polyester and the good permeability to recording materials such as paper.

In this way, the toner exhibits excellent low-temperature fixability,
When the heat roller fixing method is applied, the set temperature of the heat roller can be set lower than before, so that the durability of the heat roller can be improved, and the warm-up time can be shortened for quick image formation. It will be possible.

Further, even when an image is formed on both sides of the recording material, the image can be stably formed without causing curling, wrinkling, or the like.

[Specific configuration of the invention]

In the present invention, a crystalline polyester and a number average molecular weight
The ratio of the weight average molecular weight Mw to Mn Mw / Mn is 3.5 or more, and is an ionically cross-linked amorphous vinyl polymer (hereinafter also referred to as "ion-cross-linked amorphous vinyl polymer") A toner for developing an electrostatic image is constituted by using a block copolymer or a graft copolymer formed by bonding as an essential component.

The toner of the present invention can be applied to either one-component developer containing no carrier or two-component developer containing carrier.

The ionic crosslinked amorphous vinyl polymer needs to have a functional group for forming a block copolymer or a graft copolymer with the crystalline polyester. Examples of such a functional group include a carboxyl group, a hydroxyl group, an amino group,
Epoxy groups and the like can be mentioned as preferable ones.

Examples of the monomer having such a functional group include acrylic acid, β, β-dimethylacrylic acid, α-ethylacrylic acid, methacrylic acid, fumaric acid, itaconic acid, maleic acid, crotonic acid, hydroxyethyl methacrylate and amber. Examples thereof include acid monoacryloyloxyethyl ester, N-hydroxyethylacrylamide, N-methylolacrylamide, p-aminostyrene and glycidyl methacrylate. The monomer having such a functional group is 0.1 to 20 mol% in the monomer composition for obtaining the ionically crosslinked amorphous vinyl polymer, preferably 0.5 to
It is preferably used in a proportion of 10 mol%.

Further, the ionic crosslinked amorphous vinyl polymer needs to be an amorphous vinyl polymer having a structure crosslinked by an ionic bond. As the vinyl polymer, polystyrene, polymethyl methacrylate, polymethyl acrylate,
Examples thereof include polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, and the like. Among them, a vinyl polymer obtained by using at least one selected from a styrene-based monomer, an acrylic acid-based monomer, and a methacrylic acid-based monomer as an essential component is preferable. And
In particular, it is preferable that the polyvalent metal compound reacts with the carboxyl group of the vinyl polymer having a carboxyl group to form an ionic cross-linkage bond. In order to obtain such a vinyl polymer having a carboxyl group, in addition to the above monomers, a monomer selected from acrylic acid or methacrylic acid and derivatives thereof may be used as an essential component for polymerization.

Preferred examples thereof include a half-ester compound having a structure obtained by an esterification reaction of an acrylic acid ester or a methacrylic acid ester having a hydroxyl group or a derivative thereof with a dicarboxylic acid compound. According to such a half-ester compound, since the carboxyl group is introduced at a position that has little influence on the main chain structure,
The steric hindrance of the chemical structure is reduced, and as a result, the reaction between the carboxyl group and the polyvalent metal compound proceeds efficiently to form an ionic cross-linking bond, and an ionic cross-linking amorphous vinyl polymer having a good cross-linking structure can be obtained. it can.

Examples of the styrene-based monomer for obtaining the vinyl polymer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene,
p-ethylstyrene, 2,3-dimethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-
Butyl styrene, pn-hexyl styrene, pn-
Octyl styrene, pn-nonyl styrene, pn-
Examples thereof include decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p-chlorostyrene, and 3,4-dichlorostyrene. These monomers may be used alone or in combination of two or more.

Examples of acrylic acid ester or methacrylic acid ester for obtaining the vinyl polymer include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, propyl acrylate, octyl acrylate, dodecyl acrylate, lauryl acrylate. , 2-ethylhexyl acrylate, stearyl acrylate,
2-chloroethyl acrylate, phenyl acrylate,
Acrylic acid esters such as α-methyl chloroacrylate; for example, methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, isobutyl methacrylate, octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, methacrylic acid-2-
Methacrylic acid esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; and the like can be mentioned.

Examples of the compound having a carboxyl group that forms the half-ester compound include aliphatic dicarboxylic acid compounds such as malonic acid, succinic acid and glutaric acid, and aromatic dicarboxylic acid compounds such as phthalic acid.
A half-ester compound can be obtained by subjecting these compounds to an esterification reaction of an acrylic acid ester or a methacrylic acid ester having a hydroxyl group or a derivative thereof. The dicarboxylic acid compound may have a hydrogen atom substituted with a halogen group element, a lower alkyl group, an alkoxy group, or the like, or may be an acid anhydride. The acrylic acid or methacrylic acid derivative having a hydroxyl group may be acrylic acid or methacrylic acid to which 1 mol or 2 mol or more of an alkylene oxide such as ethylene oxide or propylene oxide is added, or acrylic acid or methacrylic acid. It may be a hydroxyalkyl ester obtained by subjecting a dihydric alcohol such as propylene glycol to an esterification reaction.

Preferred half-ester compounds include, for example, succinic acid monoacryloyloxyethyl ester, succinic acid monoacryloyloxypropyl ester, glutaric acid monoacryloyloxyethyl ester, phthalic acid monoacryloyloxyethyl ester, phthalic acid monoacryloyloxypropyl ester, succinic acid. Examples thereof include monomethacryloyloxyethyl ester, succinic acid monomethacryloyloxypropyl ester, glutaric acid monomethacryloyloxyethyl ester, phthalic acid monomethacryloyloxyethyl ester, and phthalic acid monomethacryloyloxypropyl ester.

The metal element of the polyvalent metal compound to be reacted with the carboxyl group of the vinyl polymer having a carboxyl group,
For example, Cu, Ag, Be, Mg, Ca, Sr, Ba, Zn, Cd, Al, Ti, Ge, Sn, V, Cr,
Mo, Mn, Fe, Ni, Co, Zr, Se, etc. can be mentioned. Among these, alkaline earth metals (Be, Mg, Ca, Sr, Ba) and zinc group elements (Zn, Cd) are preferable, and Mg and Zn are particularly preferable.

As the polyvalent metal compound containing these metals, for example,
Of the above metal elements, fluoride, chloride, chlorate, bromide, iodide, oxide, hydroxide, sulfide, sulfite,
Lower alkyl metal compounds such as sulfates, selenides, tellurides, nitrides, nitrates, phosphides, phosphinates, phosphates, carbonates, orthosilicates, acetates, oxalates, methyl compounds or ethyl compounds Etc. can be mentioned. Of these, acetates of the above metal elements and oxides of the above metal elements are particularly preferable.

The amount of the polyvalent metal compound added cannot be unconditionally specified because it varies depending on the type and amount of the monomer constituting the vinyl polymer having a carboxyl group, but for example, it is based on 1 mol of the vinyl polymer. Therefore, it is about 0.1 to 1 mol.

To react the polyvalent metal compound with the carboxyl group of the vinyl polymer having a carboxyl group, for example, a solution containing the vinyl polymer having a carboxyl group obtained by polymerization by a solution polymerization method is added to the polyvalent metal compound. The compound or the dispersion solution of the polyvalent metal compound is mixed, the temperature is raised and the solvent removal treatment is performed for 1 to 3 hours, and the temperature in the reaction system reaches about 150 to 180 ° C for 1 hour or more. It is recommended to maintain the temperature to complete the reaction. In some cases, a polyvalent metal compound may be allowed to be present in the reaction system together with a solvent before starting the polymerization of the vinyl polymer having a carboxyl group, or the carboxyl group obtained by performing the solvent removal treatment is You may make it react by melt-kneading the vinyl polymer which has and a polyvalent metal compound with a roll mill, a kneader, an extruder, etc.

Thus, the ion-crosslinked amorphous vinyl polymer obtained by reacting the vinyl polymer having a carboxyl group and the polyvalent metal compound, the carboxyl group of the vinyl polymer having a carboxyl group and the polyvalent metal atom Are bonded by an ionic bond, and this kind of ionic bond forms a kind of crosslinked structure. This ionic bond is a much slower bond than a covalent bond.

From the viewpoint of further improving low-temperature fixability and anti-offset property, the ion-crosslinked amorphous vinyl polymer preferably has at least two maximum values in the molecular weight distribution. Specifically, it has a molecular weight distribution that can be divided into at least two groups, a low molecular weight component with a small maximum molecular weight and a high molecular weight component with a large maximum molecular weight, and the molecular weight measured by gel permeation chromatography (GPC). At least one local maximum in the distribution curve
It is preferred to have at least two maxima such that they are in the range of 2,000 to 20,000 and at least one maxima is in the range of 100,000 to 1,000,000.
Further, since it is possible to make the ionically crosslinked amorphous vinyl polymer tougher by the high molecular weight component,
In the friction with the carrier or the collision with the latent image carrier, the effect of suppressing the destruction of the toner particles is great, and as a result, the generation of fine powder that causes the filming phenomenon is suppressed. In addition,
The proportion of the high molecular weight component is preferably 15% by weight or more of the ionically crosslinked amorphous vinyl polymer, and particularly 15 to 50%.
Weight percent is preferred.

When the ionically cross-linked amorphous vinyl polymer is composed of a high molecular weight component and a low molecular weight component as described above, it is preferable that a carboxyl group that reacts with the polyvalent metal compound is introduced into at least the low molecular weight component. . That is,
The destruction of the toner particles caused by friction with the carrier or collision with the surface of the latent image bearing member is mainly due to the relatively fragile component having a low molecular weight in the toner particles, and thus such a low molecular weight component will be described in detail later. By crosslinking the polyvalent metal compound by an ionic bond, so to speak, to make it tough, it is possible to effectively prevent the generation of fine powder that causes the filming phenomenon caused by the destruction of the toner particles.

In the ion-crosslinked amorphous vinyl polymer, the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn needs to be 3.5 or more, and preferably 4 to 40. The ratio
When Mw / Mn is too small, sufficient offset resistance and durability cannot be obtained. Here, the values of the weight average molecular weight Mw and the number average molecular weight Mn can be obtained by various methods, and there are some differences due to the difference in the measuring methods, but in the present invention, those obtained by the following measuring methods. Is.

That is, the weight average molecular weight M is determined by gel permeation chromatography (GPC) under the following conditions.
w, number average molecular weight Mn, peak molecular weight are measured. Temperature 40
1.2 ml / min of solvent (tetrahydrofuran) at ℃
Flow at a flow rate of, and inject 3 mg of a tetrahydrofuran sample solution with a concentration of 0.2 g / 20 ml as a sample weight for measurement. When measuring the molecular weight of a sample, select the measurement conditions that fall within the range in which the logarithm of the molecular weight of the calibration curve and the count number are linear, using monodisperse polystyrene standard samples of which the sample has several molecular weights. . The reliability of the measurement results is based on the NBS706 polystyrene standard sample (weight average molecular weight Mw = 28.8 × 10 ⁴ , number average molecular weight M measured under the above-mentioned measurement conditions).
n = 13.7 × 10 ⁴ , Mw / Mn = 2.11) ratio Mw / Mn value is 2.11 ± 0.1
Confirm by setting to 0.

Any GPC column may be used as long as it satisfies the above conditions.
Specifically, for example, TSK-GEL, GMH (manufactured by Toyo Soda Co., Ltd.) and the like can be used. The solvent and measurement temperature are not limited to the above conditions, and may be changed to other conditions as appropriate.

As the ionically cross-linked amorphous vinyl polymer, those having at least two local maxima in the molecular weight distribution curve can be preferably used as described above, but the method for obtaining such vinyl polymer is not particularly limited. For example, the first stage polymerization is carried out to obtain either a high molecular weight component having a large maximum molecular weight or a low molecular weight component having a small maximum molecular weight, and one component thus obtained is obtained as the other component. To obtain a polymer having at least two local maxima in the molecular weight distribution curve by dissolving it in a monomer composition for carrying out the second-stage polymerization and thereby producing the other component. You can Thus, the polymer obtained by the two-step polymerization is presumed to be a mixture of the low molecular weight component and the high molecular weight component uniformly at the molecular level. This two-stage polymerization can be performed by, for example, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, etc., but a solution polymerization method is particularly preferable.

Further, the polymer having at least two maximum values in the molecular weight distribution curve can also be obtained by mixing a low molecular weight polymer component having a small maximum molecular weight and a high molecular weight polymer component having a large maximum molecular weight. However, since the polymer obtained by mixing may not be uniformly mixed at the molecular level, it is preferable to use the above two-stage polymerization.

Further, low-temperature fixing property, offset resistance, from the viewpoint of further improving the durability, the glass transition point Tg of the ionically cross-linked amorphous vinyl polymer is preferably 50 to 100 ° C., and particularly 50 to 85.
C is preferred. Here, the glass transition point Tg is a value measured based on a differential scanning calorimetry (DSC), and specifically, for example, "DSC-20" (manufactured by Seiko Denshi Kogyo Co., Ltd.) When measured at a speed of 10 ° C./min, it means the temperature at the intersection of the extension line of the baseline below the glass transition point and the tangent line showing the maximum slope from the rising portion of the peak to the apex of the peak.

The crystalline polyester forming a block copolymer or a graft copolymer with the above ion-crosslinked amorphous vinyl polymer is one having a crystal structure in at least a part of the polyester, and in a homopolymer or a copolymer. It has a sharp and clear melting point, including at least one component that is crystalline, that is, partially crystallized, and shows clouding due to a crystallized portion in the solid state at a temperature below the melting point.

As such crystalline polyester, polyalkylene polyester is particularly preferable from the viewpoint of low temperature fixability and fluidity. Specifically, for example, polyethylene sebacate, polyethylene adipate, polyethylene suberate, polyethylene succinate, polyethylene-p- (carbophenoxy) undecaate, polyhexamethylene oxalate, polyhexamethylene sebacate, polyhexamethylene decandioate. , Polyoctamethylene dodecanedioate, polynonamethylene azelate, polydecamethylene adipate, polydecamethylene azelate, polydecamethylene oxalate, polydecamethylene sebacate, polydecamethylene succinate, polydecamethylene dodecanedioate , Polydecamethylene octadecanedioate, polytetramethylene sebacate, polytrimethylene dodecanedioate, polytrimethylene octadecanedioate, polito Methylene Ok The rate, polyhexamethylene - decamethylene - sebacate, polyoxyethylene decamethylene-2-methyl-1,3-propane - can be exemplified dodecanedioate like.

The melting point Tm of the crystalline polyester is 50 to 120 ° C., especially 50 to 1
00 ° C is preferred. If the melting point Tm is too low, blocking resistance tends to deteriorate, and if the melting point Tm is too high, low temperature fixability tends to deteriorate. The melting point Tm of this crystalline polyester was measured in a state where it was not bound to the ionically crosslinked amorphous vinyl polymer. The melting point Tm refers to a melting peak value when 10 mg of a sample is heated at a constant heating rate (10 ° C./min) according to a differential scanning calorimetry (DSC).

The crystalline polyester has a weight average molecular weight Mw of 5,000 to 50,000 and a number average molecular weight Mn of 2,000 to 20,000.
Are preferred.

The proportion of the crystalline polyester is 3 to 50% by weight, particularly 5 to 5% by weight in the block copolymer or the graft copolymer.
40% by weight is preferred. If the proportion of the crystalline polyester is too small, the low temperature fixability tends to deteriorate, and conversely if the proportion is too large, the offset resistance tends to deteriorate.

It is preferable that the crystalline polyester and the ionically cross-linked amorphous vinyl polymer are substantially incompatible. The term "substantially incompatible" means that the crystalline polyester and the ionically cross-linked amorphous vinyl polymer are not sufficiently dispersed. Specifically, for example, the SP value by the method of Fedose [RF Frdors, P
olym.Eng.Sci., 14 , (2) 147 (1974)] is greater than 0.5.

In order to obtain a block copolymer or a graft copolymer in which a crystalline polyester and an ionically cross-linked amorphous vinyl polymer are chemically bonded, for example, a coupling reaction between terminal functional groups is performed in a head-to-tail manner. They can be linked directly to each other or by a terminal functional group and a bifunctional coupling agent. For example, a urethane bond formed by the reaction of a polymer whose terminal group is a hydroxyl group and diisocyanate, a reaction of a polymer whose terminal group is a hydroxyl group with a dicarboxylic acid, or a reaction of a polymer whose terminal group is a carboxyl group with a glycol. Can be bound by an ester bond formed by the above, or by another bond formed by the reaction of a polymer having a hydroxyl group as a terminal group with phosgene or dichlorodimethylsilane.

Examples of such coupling agents include difunctional isocyanates such as hexamethylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, tolidine diisocyanate, naphthylene diisocyanate, isophorone diisocyanate and xylylene diisocyanate; for example ethylenediamine, hexamethylenediamine, phenylenediamine and the like. Difunctional amines such as oxalic acid, succinic acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid; for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanediene. Bifunctional alcohols such as methanol and p-xylylene glycol; for example, terephthalic acid chloride, isophthalic acid It may include, for example, diisothiocyanate, Bisuketen, other bifunctional coupling agents such as bis-carbodiimide; Rorido, adipic acid chloride, difunctional acid chlorides such as sebacic acid chloride.

The coupling agent, based on the total amount of the crystalline polyester and the ionically crosslinked amorphous vinyl polymer, 1 to 10% by weight,
It is particularly preferable to use it in a proportion of 2 to 7% by weight. When the proportion of the coupling agent is too large, the softening point of the resulting block copolymer or graft copolymer becomes too high, and the low-temperature fixability tends to deteriorate, and when it is too small, the offset resistance tends to deteriorate.

In the present invention, the specific block copolymer or graft copolymer as described above is used as a resin for toner, but other resins may be used in combination if necessary. However, the proportion of the block copolymer or graft copolymer in the toner is preferably 30% by weight or more.

The toner of the present invention may contain various additives as required. Examples of such an additive include a colorant, a charge control agent, and a fixing property improver.

Examples of colorants include carbon black, nigrosine dye, aniline blue, chalco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, These mixtures, etc. can be mentioned.

Examples of the charge control agent include metal complex dyes, nigrosine dyes, ammonium compounds and the like.

As the fixability improver, polyolefin, fatty acid metal salt, fatty acid ester and fatty acid ester wax,
Partially saponified fatty acid ester, higher fatty acid, higher alcohol, liquid or solid paraffin wax, polyamide wax, polyhydric alcohol ester, silicone varnish, aliphatic fluorocarbon and the like can be mentioned.
Especially, the softening point by ring and ball method (JIS K 2531) is 60-150 ℃
Waxes are preferred.

Further, the toner of the present invention may further contain inorganic fine particles as a fluidity improver or an abrasive. In such inorganic fine particles, the average diameter of primary particles (particles separated into individual unit particles) is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Further, the specific surface area by the BET method is preferably 20 to 500 m ² / g. The addition ratio of the inorganic fine particles to the toner is preferably 0.01 to 5% by weight, particularly preferably 0.01 to 2.0% by weight.

Specific examples of the inorganic fine particles include 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 trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide,
Examples thereof include silicon nitride. Silica fine powder is particularly preferable.

This silica fine powder is a fine powder having a Si-O-Si bond, and includes those produced by a dry method or a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate and the like may be used, but those containing 85% by weight or more of SiO ₂ are preferable. As a specific example of the fine silica powder, those having a hydrophobic group on the surface are preferable, for example, "Aerosil R-972", "Aerosil R-974",
Commercially available products such as "Aerosil R-805", "Aerosil R-812" (all manufactured by Nippon Aerosil Co., Ltd.) and "Taranox 500" (manufactured by Tarco Co.) can be preferably used.
In addition to these, a silica fine powder surface-treated with a silane coupling agent, a titanium coupling agent, a silicone oil, a silicone oil having an amine in a side chain, or the like can be used.

Further, the toner of the present invention may further contain a cleaning property improver. Examples of such a cleaning property improver include zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, polymer fine particles such as methyl methacrylate fine particles and styrene fine particles.

Further, when obtaining a magnetic toner, fine particles of a magnetic material are contained in the toner particles. As such a magnetic material, iron,
Ferrite, magnetite and other iron, nickel, cobalt, and other ferromagnets or alloys, or compounds containing these elements, but which do not contain ferromagnetism, but exhibit ferromagnetism by appropriate heat treatment Alloys such as manganese-copper-aluminum, manganese-
Examples include alloys of the type called Heusler alloys containing manganese such as copper-tin and copper, chromium dioxide, and the like. It is preferable that the magnetic substance is uniformly dispersed and contained in the form of fine powder having an average particle diameter of 0.1 to 1 μm. The content ratio of the magnetic substance is preferably 10 to 70% by weight of the toner, and particularly preferably 20 to 50% by weight.

The toner according to the present invention can be manufactured, for example, as follows. That is, the toner resin or the one to which an additive is further added, if necessary, is melt-kneaded by, for example, an extruder, cooled, and then finely pulverized by a jet mill or the like, which is classified to obtain a toner having a predetermined particle diameter. It can be manufactured. Alternatively, a toner having a predetermined particle size can be produced by melt-kneading with an extruder, spraying it with a spray dryer or the like and dispersing it in a liquid in a molten state.

In the case of a two-component developer, basically the toner according to the present invention and a carrier are mixed to form a developer. Such a carrier is not particularly limited, and a conventionally known carrier can be used. Specifically, a non-coated carrier composed only of magnetic particles, a resin-coated carrier in which the surface of magnetic particles is coated with a resin, and a magnetic material dispersion type in which magnetic particles are dispersed and contained in resin particles A carrier or the like can be used. The average particle size of the carrier is preferably 20 to 200 μm, particularly 30 to 150 μm
Is preferred. Here, the average particle size (weight) of the carrier is
It is a value measured using "Microtrac" (manufactured by Nikkiso Co., Ltd.).

With the toner of the present invention, an image can be formed, for example, as follows. That is, in electrophotography, an electrostatic latent image formed on a latent image carrier is developed with an electrostatic image developer, and the obtained unfixed toner image is electrostatically applied to a recording material such as paper. After the transfer, the transferred toner is fixed by the heating roller fixing method, and thus a fixed toner image is formed.

The heating roller fixing device used in the heating roller fixing method is usually composed of a heating roller, a pressure bonding roller arranged in contact with the heating roller, and a heat source. Further, a cleaning roller is arranged in contact with the heating roller as needed. While keeping the temperature of the heating roller within a certain range by the heating source, the recording material on which the toner has been transferred is passed between the heating roller and the pressure roller, so that the toner is brought into direct contact with the heating roller and the toner Is thermally fixed to the recording material. The surface material of the heating roller is preferably a fluorine-based material or a silicone-based material, and the synergistic effect with the toner of the present invention can remarkably improve the durability of the heating roller fixing device.

〔Example〕

Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

<Production of Crystalline Polyester> (1) Crystalline Polyester 1 1500 g of sebacic acid and 964 g of hexamethylene glycol are mixed in a thermometer, a stirrer made of stainless steel, a nitrogen introduction tube made of glass, and a capacity of 5 l equipped with a flow-down condenser. The flask was placed in a round bottom flask, and then this flask was set in a mantle heater, and nitrogen gas was introduced through a glass nitrogen introducing tube to raise the temperature in a state where the inside of the reactor was kept in an inert atmosphere. Then, 13.2 g of p-toluenesulfonic acid was added and reacted at a temperature of 150 ° C. When the amount of distilled water reached 250 ml, the reaction was stopped and the reaction system was cooled to room temperature to produce crystalline polyester 1 made of polyhexamethylene sebacate having a hydroxyl group at the molecular end.

This crystalline polyester 1 has a melting point Tm of 64 ° C. and a weight average molecular weight Mw of 14,000.

(2) Crystalline Polyester 2 In the same manner as the crystalline polyester 1, a crystalline polyester 2 made of polyethylene sebacate having a melting point Tm of 72 ° C. and a weight average molecular weight Mw of 12,800 was produced.

(3) Crystalline Polyester 3 In the same manner as the crystalline polyester 1, a crystalline polyester 3 made of polyethylene succinate having a melting point Tm of 92 ° C. and a weight average molecular weight Mw of 14,800 was produced.

(4) Crystalline Polyester 4 In the same manner as the crystalline polyester 1, a crystalline polyester 4 having a melting point Tm of 77 ° C. and a weight average molecular weight Mw of 8,370 polydecamethylene adipate was produced.

<Production of Amorphous Vinyl Polymer> (1) Amorphous Vinyl Polymer 1 100 parts by weight of toluene was placed in a separable flask having a volume of 1, and 75 parts by weight of styrene as a monomer for a high molecular weight component was placed therein. , N-butyl acrylate (25 parts by weight) and benzoyl peroxide (0.2 parts by weight) were added to suspend and disperse, and the gas phase in the flask was replaced with nitrogen gas.
The first stage polymerization was carried out by raising the temperature to 15 ° C. and maintaining the temperature for 15 hours. The weight average molecular weight Mw in the homopolymer of the high molecular weight component monomer is 461,000, the glass transition point Tg is 61.
℃.

After that, the inside of the flask was cooled to a temperature of 40 ° C, and in it,
85 parts by weight of styrene as a monomer for low molecular weight component, n
10 parts by weight of butyl methacrylate, 5 parts by weight of acrylic acid, and 4 parts by weight of benzoyl peroxide were added, and the temperature was 40 ° C.
After continuing the stirring for 2 hours, the temperature was raised again to 80 ° C. and kept at that temperature for 8 hours to carry out the second stage polymerization. The weight average molecular weight Mw of the homopolymer of the monomer for low molecular weight component is 8,200, and the glass transition point Tg is 64 ° C.

Next, in the flask, zinc oxide which is a polyvalent metal compound.
5 g was added, and the reaction was carried out for 2 hours while stirring at the reflux temperature.

After that, the reaction system is cooled to separate the solid matter, and after dehydration and washing are repeated, it is dried to form an ionic crosslinked bond by reacting zinc oxide with the carboxyl group of the vinyl polymer to form an amorphous vinyl. Polymer 1 was produced. The amorphous vinyl polymer 1 has a carboxyl group as a functional group for binding with the crystalline polyester.

This amorphous vinyl polymer 1 has two peaks in the molecular weight distribution by GPC, the peak molecular weight on the high molecular weight side is 363,000, and the peak molecular weight on the low molecular weight side is 7,590.
The weight average molecular weight Mw is 165,000 and the ratio Mw / Mn is 25.
9. Glass transition point Tg is 62 ℃, softening point Tsp is 130 ℃.

(2) Amorphous vinyl polymer 2 100 parts by weight of toluene was placed in a separable flask having a volume of 1, and 85 parts by weight of styrene, 10 parts by weight of n-butyl acrylate, and 5 parts by weight of acryloyloxyethyl monosuccinate were placed therein. And 1 part by weight of benzoyl peroxide were added to suspend and disperse, and the gas phase in the flask was replaced with nitrogen gas, then the temperature was raised to 80 ° C. and the temperature was maintained for 5 hours to carry out polymerization. .

Then, 4 parts by weight of benzoyl peroxide was further added, and the polymerization was continued at a temperature of 80 ° C. for 10 hours.

Next, in the flask, zinc oxide which is a polyvalent metal compound.
5 g was added, and the reaction was carried out for 2 hours while stirring at the reflux temperature.

Then, toluene was distilled off by an aspirator and a vacuum pump to produce an amorphous vinyl polymer 2 in which zinc oxide reacts with a carboxyl group of the vinyl polymer to form an ionic cross-linkage bond. The amorphous vinyl polymer 2 has a carboxyl group as a functional group for binding with the crystalline polyester.

This amorphous vinyl polymer 2 has one peak in the molecular weight distribution by GPC, and the weight average molecular weight Mw is 83,00.
0, ratio Mw / Mn value is 7.5, glass transition point Tg is 67 ° C, softening point T
sp is 127 ° C.

(3) Amorphous vinyl polymer 3 In the production of the amorphous vinyl polymer 1, 75 parts by weight of styrene, 20 parts by weight of n-butyl acrylate, and 5 parts by weight of glycidyl methacrylate were used as monomers for the high molecular weight component. , 30 parts of a mixture with 0.2 part by weight of benzoyl peroxide, 75 parts by weight of styrene, 10 parts by weight of n-butyl acrylate, 10 parts by weight of methyl methacrylate, 2.5 parts by weight of glycidyl methacrylate as a monomer for low molecular weight component. And acryloyloxyethyl monosuccinate 2.
100 g of a mixture of 5 parts by weight and 4 parts by weight of benzoyl peroxide
Was treated in the same manner as described above, except that an amorphous vinyl polymer 3 was produced in which zinc oxide was reacted with the carboxyl group of the vinyl polymer to form an ionic bond. The amorphous vinyl polymer 3 has an epoxy group as a functional group for binding with the crystalline polyester.

This amorphous vinyl polymer 3 has two peaks in the molecular weight distribution by GPC, the peak molecular weight on the high molecular weight side is 473,000, and the peak molecular weight on the low molecular weight side is 7,940.
The weight average molecular weight Mw is 186,000 and the ratio Mw / Mn is 33.
1. Glass transition point Tg is 62 ℃, softening point Tsp is 136 ℃.

The weight average molecular weight Mw in the homopolymer of the high molecular weight component monomer is 925,000, the glass transition point Tg is 62 ℃, the weight average molecular weight Mw in the homopolymer of the low molecular weight component monomer is 9,610, glass transition point Tg is 63 ℃.

(4) Amorphous Vinyl Polymer 4 (Comparative) Amorphous vinyl polymer 1 for comparison was produced in the same manner as in the production of amorphous vinyl polymer 1, except that zinc oxide was not added. This comparative amorphous vinyl polymer 4 has a carboxyl group as a functional group for bonding with the crystalline polyester.

The amorphous vinyl polymer 4 for comparison has two peaks in the molecular weight distribution by GPC, the peak molecular weight on the high molecular weight side is 355,000, and the peak molecular weight on the molecular weight side is 6,840. The weight average molecular weight Mw is 142,000, the ratio Mw / Mn is 24.5, the glass transition point Tg is 60 ° C., and the softening point Tsp is 128.5 ° C.

<Production of Resin for Toner> (1) Resin A for Toner 15 parts by weight of crystalline polyester 1, 85 parts by weight of amorphous vinyl polymer 1, 0.05 parts by weight of p-toluenesulfonic acid, and 100 parts by weight of xylene. And were placed in a separable flask having a volume of 3 l and refluxed at a temperature of 150 ° C. for 1 hour,
Thereafter, xylene was distilled off by an aspirator and a vacuum pump to produce a toner resin A composed of a graft copolymer of crystalline polyester and an ionically crosslinked amorphous vinyl polymer.

(2) Toner Resins B to E In the same manner as in the production of the above-mentioned toner resin A, the crystalline polyester and the amorphous vinyl polymer were changed to the combinations shown in Table 1 below, and the crystalline polyester and the amorphous vinyl polymer were not ion-crosslinked. Resins B to E for toner, each of which was composed of a graft copolymer with a regular vinyl polymer, were produced.

(3) Toner resin F (for comparison) In the same manner as in the production of the above-mentioned toner resin A, a graft copolymer was used except that the comparative amorphous vinyl polymer 4 was used in place of the amorphous vinyl polymer 1. A resin F for toner was manufactured.

Example 1 100 parts by weight of the resin A for toner, 10 parts by weight of carbon black "Mogal L" (manufactured by Cabot Corporation), and 3 parts by weight of the fixing property improver "wax E" (manufactured by Hoechst) were mixed, After melt-kneading with a heating roller, cooling, coarse crushing, fine crushing with a supersonic jet mill, and classification with an air classifier to obtain a powder.

To 100 parts by weight of this powder, 0.8 part by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was mixed by a V-type mixer, and the toner 1 according to the present invention having an average particle size of 11.0 μm was mixed. Was manufactured.

Example 2 A toner 2 according to the present invention was manufactured in the same manner as in Example 1 except that the resin A for toner was changed to the resin B for toner.

Example 3 A toner 3 according to the present invention was manufactured in the same manner as in Example 1, except that the toner resin A was changed to the toner resin C.

Example 4 A toner 4 according to the present invention was manufactured in the same manner as in Example 1 except that the toner resin A was changed to the toner resin D.

Example 5 A toner 5 according to the present invention was manufactured in the same manner as in Example 1 except that the resin A for toner was changed to the resin E for toner.

Comparative Example 1 A comparative toner 1 was manufactured in the same manner as in Example 1 except that the resin A for toner was changed to the resin F for toner for comparison.

Comparative Example 2 Comparative Toner 2 was prepared in the same manner as in Example 1 except that the resin A for toner was changed to a simple mixture of 15 parts by weight of the crystalline polyester 1 and 85 parts by weight of the amorphous vinyl polymer 1. Manufactured.

Comparative Example 3 A comparative toner 3 was produced in the same manner as in Example 1 except that the resin A for toner was changed to the amorphous vinyl polymer 1.

<Preparation of Developer> A carrier for an electrophotographic copying machine "U-Bix 1600" (manufactured by Konica Corp.) and each of the above toners are mixed to prepare a two-component developer having a toner concentration of 4% by weight. Prepared.

<Evaluation> (1) Evaluation test of low-temperature fixing property An electrophotographic copying machine "U-Bix 1600" (manufactured by Konica Corporation) modified machine equipped with a selenium latent image carrier and a developing device for two-component developer was used. An electrostatic latent image was developed using each of the developers described above, and the toner image obtained by the development was transferred onto a recording material made of 64 g / m ² paper to form an unfixed toner image.

Next, a heating roller fixing device having a heating roller having a surface of Teflon (polytetrafluoroethylene) and having a diameter of 30 mm and a pressure roller having a surface layer of silicone rubber "KE-1300RTV" (manufactured by Shin-Etsu Chemical Co., Ltd.). Thus, the operation of fixing under the conditions of linear velocity of 70 mm / sec, linear pressure of 0.8 kg / cm and nip width of 4.9 mm was repeated at each temperature where the set temperature of the heating roller was changed stepwise by 5 ° C. Kimwipe rubbing was performed on the fixed toner image, and the minimum set temperature (minimum fixing temperature) of the fixed toner image showing sufficient rubbing resistance was measured. The heating roller fixing device does not have a mechanism for applying a release agent such as silicone oil.

(2) Offset resistance evaluation test Immediately after forming a fixed toner image in the same manner as in the above-mentioned low temperature fixing property evaluation test, a blank recording material was sent to a heating roller fixing device under the same conditions to prevent toner stains. The operation of visually observing whether or not it occurred was performed at each set temperature of the heating roller, and the minimum set temperature (offset generation temperature) when the toner was stained was measured.

(3) Storability evaluation test 2 g of each toner was put in a sample tube and
After tapping 500 times, the mixture was allowed to stand in an atmosphere of a temperature of 55 ° C. and a relative humidity of 26% for 2 hours, and then separated by a 48-mesh sieve, and the proportion of aggregates remaining on the sieve was measured.

(4) Durability evaluation test An electrophotographic copying machine "U-Bix 1600" (Konica) equipped with a selenium latent image carrier, a developing device for two-component developer, and a heating roller fixing device using each of the above developers. Durability was evaluated by performing a live-action test 10,000 times under normal temperature and normal humidity conditions (temperature 20 ° C, relative humidity 60%) using a modified machine (manufactured by Co., Ltd.), and visually observing the obtained images. did.

(5) Flowability evaluation test Taking advantage of the fact that the higher the flowability of the granular material is, the smaller the degree of compression is. The static dry density of the toner was determined. In the evaluation, a static dry density of 0.38 g / ml or more was evaluated as “◯”, and a static bulk density of less than 0.38 g / ml was evaluated as “x”.

The above results are shown in Table 1.

As can be understood from the results shown in Table 1, according to the toners 1 to 5 of the invention, (1) low temperature fixability, (2) offset resistance, (3) storability, and (4) developability. (5) Excellent performance is exhibited in all aspects of durability.

On the other hand, in Comparative Toner 1, since the amorphous vinyl polymer constituting the toner resin F is not an ion-crosslinked amorphous vinyl polymer, the storage stability is remarkably poor, and therefore the durability is remarkably poor.

Comparative Toner 2 was inferior in terms of low-temperature fixability, offset resistance, and storability because the toner resin was a mere mixture of crystalline polyester and ion-crosslinking amorphous vinyl polymer, and thus durability. Is also bad.

Since the toner resin of Comparative Toner 3 is composed of only the ion-crosslinking amorphous vinyl polymer, the low-temperature fixability is poor. In addition, image stains due to under-offset occur early, resulting in poor durability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroki Kabashima 2970 Ishikawa-cho, Hachioji City, Tokyo Konica Co., Ltd. (56) References JP 61-110155 (JP, A) JP 60-187348 ( JP, A) JP 60-187350 (JP, A) International publication 86-5602 (WO, A)

Claims (4)

[Claims] 1. A block obtained by chemically bonding a crystalline polyester and an ionically cross-linked amorphous vinyl polymer having a ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 3.5 or more. An electrostatic image developing toner comprising a copolymer or a graft copolymer. 2. An ionically cross-linked amorphous vinyl polymer,
The toner for electrostatic image development according to claim 1, wherein the carboxyl group of the vinyl polymer having a carboxyl group is reacted with a polyvalent metal compound to form an ionic cross-linkage bond. 3. A functional group chemically bonded to the crystalline polyester in the ionically cross-linked amorphous vinyl polymer,
Claim 1 or 2 which is a carboxyl group, a hydroxyl group, an amino group or an epoxy group.
Item 4. The toner for developing an electrostatic image according to item. 4. An ionically cross-linked amorphous vinyl polymer comprises:
The electrostatic image developing toner according to any one of claims 1 to 3, wherein the toner has at least two maximum values in a molecular weight distribution.