JP6975063B2 - Toner for electrophotographic binder and toner - Google Patents

Description

The present invention relates to a toner used for electrophotographic, electrostatic recording, electrostatic printing, etc., which contains a toner binder for electrophotographic and a toner binder for electrophotographic.

In electrophotographic, a method using a heat roller to fix an electrostatic latent image visualized by toner is widely adopted.
When this method is used, the minimum fixing temperature of the toner (the lowest temperature of the heat roller that can obtain a fixing rate of 70%) is low (low temperature fixability), and the hot offset temperature (the lowest temperature of the heat roller that causes hot offset) is low. High (hot offset resistance) is desired. Further, it is desired that a clear image can be obtained even after long-term use (image stability). In order to satisfy these demands, it has been proposed to widen the molecular weight distribution of the toner binder from low molecular weight to high molecular weight and to define the order of the glass transition points of the constituents (see Patent Document 1). Further, it has been proposed to reduce the SP value difference of the polymers constituting the toner binder (see Patent Document 2).

Japanese Unexamined Patent Publication No. 9-297432 Japanese Unexamined Patent Publication No. 2010-101998

However, if the molecular weight distribution is widened in order to lower the minimum fixing temperature and raise the hot offset temperature, on the contrary, sufficient low temperature fixing property, hot offset resistance, and image stability cannot be obtained. Further, it cannot be said that it is sufficient to define the order of the glass transition points of the constituent components or to reduce the SP value difference of the constituent polymers.

The present inventors have reached the present invention as a result of diligent studies to solve the above problems.
That is, the present invention comprises a styrene (co) polymer (a) having a weight average molecular weight of 3,000 or more and 30,000 or less, a styrene (co) polymer (b) having a weight average molecular weight of more than 30,000 and 500,000 or less, and a weight average. An electrophotographic toner binder containing a styrene (co) polymer (c) having a molecular weight of more than 500,000 and 1.2 million or less, wherein (a) and (b), (b) and (c), and (a) are used. In any combination of (c) and (c), the absolute value of the difference between the SP values is 0.00 to 0.30, and the loss elasticity G "(120) (unit: Pa) at a temperature of 120 ° C. and the temperature of 180 ° C. The storage elasticity G'(180) (unit: Pa) is an electrophotographic toner binder that satisfies the following relational expressions (1) and (2).
20000 ≤ G "(120) ≤ 60000 (1)
5000 ≤ G'(180) ≤ 10000 (2)

The toner binder for electrophotographic of the present invention has the effects of being excellent in low temperature fixing property, hot offset resistance and image stability as a toner.

Hereinafter, the present invention will be described in detail.
The toner binder for electrophotographic of the present invention contains a styrene (co) polymer (a), a styrene (co) polymer (b) and a styrene (co) polymer (c) having different weight average molecular weights. As long as the weight average molecular weight is within a predetermined range, a plurality of types (a), (b) and (c) can be used in combination.
As the monomer constituting the styrene (co) polymer (a), (b) and (c), the styrene monomer is an essential monomer, and if necessary, a (meth) acrylic monomer, a carboxyl group-containing vinyl monomer and the like are contained.
Here, the (co) polymer means a homopolymer or a copolymer, and the styrene (co) polymer means a homopolymer of a styrene monomer or a copolymer of a styrene monomer and another monomer. do. Further, (meth) acrylic means acrylic and / or methacrylic, and the same description method is used below.

Examples of the styrene monomer include styrene and alkylstyrene having an alkyl group having 1 to 3 carbon atoms (for example, α-methylstyrene and p-methylstyrene), and two or more thereof may be used in combination. Styrene is preferable.

Examples of the (meth) acrylic monomer include alkyl groups such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate. Alkyl (meth) acrylates with 1 to 18 carbon atoms; hydroxylalkyl (meth) acrylates with 1 to 18 carbon atoms of alkyl groups such as hydroxylethyl (meth) acrylates; dimethylaminoethyl (meth) acrylates, diethylaminoethyl (meth) An alkylamino group-containing (meth) acrylate having an alkyl group having 1 to 18 carbon atoms such as an acrylate; a nitrile group-containing vinyl monomer such as acrylonitrile and metaacrylonitrile can be mentioned.
Of these (meth) acrylic monomers, alkyl (meth) acrylates having 1 to 18 carbon atoms, acrylonitrile, acrylonitrile, and mixtures of two or more thereof are preferable.

Examples of the carboxyl group-containing vinyl monomer include monocarboxylic acids [3 to 15 carbon atoms, for example, (meth) acrylic acid, crotonic acid, and cinnamic acid], and dicarboxylic acids [4 to 15 carbon atoms, for example, (anhydrous) maleic acid and fumaric acid. , Itaconic acid, citraconic acid], dicarboxylic acid monoester [The monoalkyl (carbon number 1-18) ester of the dicarboxylic acid, for example, maleic acid monoalkyl ester, fumaric acid monoalkyl ester, itaconic acid monoalkyl ester, citraconic acid mono Alkyl ester] and the like.
Of these carboxyl group-containing vinyl monomers, (meth) acrylic acid, a dicarboxylic acid monoester, and a mixture of two or more thereof are preferable.

The styrene (co) polymer (a), (b), and (c) may be further used in combination with another vinyl ester monomer or an aliphatic hydrocarbon vinyl monomer, if necessary.
Examples of the vinyl ester monomer include aliphatic vinyl esters (4 to 15 carbon atoms such as vinyl acetate, vinyl propionate, isopropenyl acetate, etc.) and unsaturated carboxylic acid polyvalent (2 to 3 or more valent) alcohol esters [carbon number]. 8 to 200, for example ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethyl propanetri (meth) acrylate, 1,6 hexanediol di (meth) acrylate, And polyethylene glycol di (meth) acrylate, etc.], aromatic vinyl esters (9 to 15 carbon atoms, for example, methyl-4-vinylbenzoate, etc.) and the like.
Examples of the aliphatic hydrocarbon vinyl monomer include olefins (2 to 10 carbon atoms such as ethylene, propylene, butene and octene) and dienes (4 to 10 carbon atoms such as butadiene, isoprene and 1,6-hexadiene). Be done.
The content of the other monomers in the total constituent monomers is preferably 15% by weight or less, more preferably 0.001 to 5% by weight.

The weight average molecular weights of the styrene (co) polymers (a), (b) and (c) used in the present invention are measured by gel permeation chromatography (GPC).
The weight average molecular weight of (a) is 3,000 or more and 30,000 or less, preferably 3300 to 25,000, and more preferably 3500 to 20,000 from the viewpoint of low temperature fixability. As the styrene (co) polymer (a), two or more kinds of styrene (co) polymers having a weight average molecular weight in this range can also be used.
From the viewpoint of image stability, the weight average molecular weight of (b) is larger than 30,000 and 500,000 or less, preferably 34,000 to 480,000, and more preferably 50,000 to 450,000. As the styrene (co) polymer (b), two or more kinds of styrene (co) polymers having a weight average molecular weight in this range can also be used.
The weight average molecular weight of (c) is larger than 500,000 and 1.2 million or less, preferably 550,000 to 1.15 million, and particularly preferably 600,000 to 1.1 million, from the viewpoint of improving hot offset resistance. As the styrene (co) polymer (c), two or more kinds of styrene (co) polymers having a weight average molecular weight in this range can also be used.

The weight average molecular weight of the toner binder for electrophotographic photography of the present invention containing the styrene (co) polymers (a), (b) and (c) by GPC is preferably 150,000 to 350,000, more preferably 160,000. It is ~ 340,000, particularly preferably 170,000 ~ 330,000.
The ratio (Mw / Mn) of the weight average molecular weight Mw to the number average molecular weight Mn is preferably 15 to 150, more preferably 20 to 120, from the viewpoint of the fixing temperature range and image stability.

In the above and below, the weight average molecular weights of the styrene (co) polymer (a), (b), (c) and the toner binder are measured by using GPC under the following conditions.
Equipment (example): HLC-8220 manufactured by Tosoh
Column (example): TSKgel SuperMultipore HZ-M 3 pieces (manufactured by Tosoh)
Measurement temperature: 40 ° C
Sample solution: 0.25 wt% THF solution Injection amount: 10 μl
Detection device: Refractive index detector Standard substance: Tosoh standard polystyrene (TSK standard POLYSTYRENE) 12 points (molecular weight 500 1050 2800 5970 9100 18100 37900 96400 190000 355000 1090000 2890000)

The value of the solubility parameter (SP value [(cal / cm ³ ) ^1/2 ]) of the styrene (co) polymer used in the present invention is calculated by the formula [Polymer Engineering and Science, Vol. 14, No. 2,147 to 154 pages (Feb. 1974)].
SP (a), SP (b) and SP (c), which are the SP values of the styrene (co) polymers (a), (b) and (c), respectively, are SP (a) and SP (b). In any combination of SP (b) and SP (c) and SP (a) and SP (c), the absolute value of the difference in SP values (in other words, the largest value among them). The absolute value of the difference between the value and the minimum value) is 0.00 to 0.30, preferably 0.00 to 0.28, and more preferably 0.00 to 0.20.
In any combination of SP (a) and SP (b), SP (b) and SP (c), and SP (a) and SP (c), the absolute value of the difference in SP values is If it exceeds 0.30, the image stability deteriorates.
The difference in the SP values described above is the maximum difference in the SP values of the individual polymers when two or more of the styrene (co) polymers (a), (b) and (c) are used. Means what becomes.
The range of SP (a), SP (b) and SP (c) is preferably 10.00 to 11.00, more preferably 10.10 to 10.1 from the viewpoint of toner image stability. 90, particularly preferably 10.30 to 10.60.
For SP (a), SP (b) and SP (c), the SP value of each constituent monomer is calculated by the above method, and the SP value of each constituent monomer is calculated by the molar fraction of the constituent monomer. It is an average value based on the rate. For SP (a), SP (b) and SP (c), the SP values and mole fractions of the monomers constituting the styrene (co) polymers (a), (b) and (c) shall be appropriately adjusted. Can be set to a desired range.

In the toner binder for electrophotographic of the present invention, the loss elastic modulus G'(120) (unit Pa) at a temperature of 120 ° C. and the storage elastic modulus G'(180) (unit Pa) at a temperature of 180 ° C. have the following relational expressions ( An electrophotographic toner binder that satisfies 1) and (2).
20000 ≤ G "(120) ≤ 60000 (1)
5000 ≤ G'(180) ≤ 10000 (2)
However, the unit of the above numerical value is Pascal (Pa).
The loss modulus G "(120) is preferably 20000 ≤ G" (120) ≤ 55000, more preferably 20000 ≤ G "(120) ≤ 50,000. The storage modulus G'(180) is more preferably 5500 ≤. G'(180) ≤ 10000, more preferably 6000 ≤ G'(180) ≤ 10000.
If the loss elastic modulus G "(120) is less than 20,000, the hot offset resistance may be deteriorated, and if it exceeds 60,000, the low temperature fixability may be deteriorated.
If the storage elastic modulus G'(180) is less than 5,000, the hot offset resistance may be deteriorated, and if it exceeds 10,000, the low temperature fixability may be deteriorated.
The loss modulus G "(120) and the storage modulus G'(180) control the weight average molecular weight, the glass transition point, the SP value, and the ratio of the styrene copolymers (a), (b) and (c). Thereby, the desired range can be obtained. By satisfying the relational expressions (1) and (2), it has been experimentally found that the hot offset resistance and the low temperature fixing property are excellent.

In the above and below, the loss elastic modulus G "and the storage elastic modulus (G') are measured using the following viscoelasticity measuring device.
Equipment: ARES-24A (manufactured by Leometric)
Jig: 25mm parallel plate Frequency: 20Hz
Distortion rate: 5%

The acid value of the toner binder for electrophotographic of the present invention is preferably 0 to 10, more preferably 0.3 to 8, and particularly preferably 1 to 7 from the viewpoint of image stability.
The acid values of the styrene (co) polymers (a), (b), and (c) are all preferably 0 to 20, more preferably 0 to 16, and particularly preferably 0 to 12.
In the above and below, the acid value is measured by the method specified in JIS K0070 (potentiometric titration method).

The glass transition point (Tg) of the toner binder for electrophotographic of the present invention is preferably 50 to 70 ° C., more preferably 53 ° C. to 63 ° C. from the viewpoint of fixability. The glass transition point of the styrene (co) polymer (a) is preferably 50 to 70 ° C, more preferably 52 to 65 ° C. The glass transition point of the styrene (co) polymer (b) is preferably 50 to 75 ° C, more preferably 52 to 65 ° C. The glass transition point of the styrene (co) polymer (c) is preferably 50 to 75 ° C, more preferably 53 to 73 ° C.
In the above and below, the glass transition point (Tg) is measured by the method (DSC method) specified in ASTM D3418-82 using DSC20, SSC / 580 manufactured by Seiko Electronics Inc.

The styrene (co) polymers (a), (b) and (c) are known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization and emulsion polymerization of the monomer using the radical polymerization initiator (d). Can be synthesized with. Solution polymerization, suspension polymerization, bulk polymerization and combinations thereof are preferable.
The polymerization temperature is preferably 60 to 230 ° C, more preferably 80 to 230 ° C.
The polymerization time is preferably 1 to 30 hours, more preferably 2 to 20 hours.

Examples of (d) include an azo-based polymerization initiator (for example, azobisisobutyronitrile, azobisvaleronitrile, and azobiscyanovaleric acid) and an organic peroxide-based polymerization initiator [for example, benzoyl peroxide, di-t-). Butyl peroxide, t-butyl peroxybenzoate, 2,2-bis (4,4-di-t-butyl peroxycyclohexyl) propane, di-t-butyl peroxyhexahydroterephthalate] and the like can be mentioned.
Of these, di-t-butyl peroxide, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, and di-t-butylperoxyhexahydroterephthalate are preferred.
The amount of the polymerization initiator used is preferably 0.01 to 10% by weight, more preferably 0.05 to 8% by weight, and particularly preferably 0.1 to 6% by weight, based on the total amount of the monomers.

In the case of solution polymerization, the solvent is a cycloalkane solvent having 5 to 12 carbon atoms (cyclohexane, methylcyclohexane, etc.); an aromatic solvent having 6 to 12 carbon atoms (benzene, toluene, xylene, ethylbenzene, cumene, etc.); an ester solvent. (Ethyl acetate, butyl acetate, etc.); Ether solvents (methyl cell solve, ethyl cell solve, butyl cell solve, etc.) and the like are used.
Of these, preferred are aromatic solvents, more preferably toluene, xylene, and ethylbenzene.

In addition, when suspension polymerization is carried out, it can be polymerized in water using an inorganic acid salt dispersant (calcium carbonate, calcium phosphate, etc.), an organic dispersant (polyvinyl alcohol, methyl cellulose, etc.) and the like.

At least one of the styrene (co) polymers (a), (b), and (c) may contain a (co) polymer grafted with the wax (e) described later. In this case, the grafted wax (e) is not included in the weights of (a), (b), and (c) when determining the weight ratio of (a), (b), and (c).
The (co) polymer in which the wax (e) is grafted to the styrene (co) polymer is a peroxide-based polymer in which the wax (e) coexists during the polymerization of the styrene (co) polymers (a) to (c). It is obtained by polymerizing using a polymerization initiator. By using the styrene (co) polymer grafted with the wax (e), the stability of the image is improved. The amount of wax to be applied to the graft is preferably 0.1 to 2% by weight, more preferably 0.2 to 1% by weight, in the toner binder for electrophotographic of the present invention.

The content of the styrene (co) polymer (a) is preferably 40 to 65% by weight, more preferably 45 to 64% by weight, based on the weight of the toner binder from the viewpoint of the minimum fixing temperature.
The content of the styrene (co) polymer (b) is preferably 5 to 50% by weight, more preferably 7 to 46% by weight, based on the weight of the toner binder from the viewpoint of image stability.
The content of the styrene (co) polymer (c) is preferably 5 to 45% by weight, more preferably 5 to 40% by weight, based on the weight of the toner binder from the viewpoint of the hot offset generation temperature.

The weight ratio of the styrene (co) polymer (a), (b) and (c) [ratio to the total weight of (a), (b) and (c)] is the fixability, image density and image stability. From the viewpoint of, preferably (a) :( b) :( c) = (40 to 65) :( 5 to 50) :( 5 to 45), and more preferably (a) :( b) :( c) = (45 to 64) :( 7 to 46): (5 to 40).

The toner of the present invention contains the toner binder for electrophotographic of the present invention and a colorant. Further, various additives such as wax (e), charge control agent and fluidizing agent can be mixed as needed.

As the colorant, known pigments, dyes and magnetic powders can be used. Specifically, Carbon Black, Sudan Black SM, First Yellow-G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red, Paranitroaniline Red, Truisin Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamin FB, Rhodamin B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orazole Brown B, Oil Pink OP, and Magnetic Powder [eg, ferromagnetic metal powder] (Iron, cobalt, nickel, etc.), magnetite, hematite, ferrite, etc.] and the like.
The content of the colorant in the toner of the present invention is preferably 1 to 15% by weight, more preferably 2 to 10% by weight, based on the weight of the toner when a dye or pigment is used from the viewpoint of color development. When a magnetic powder is used, it is preferably 10 to 70% by weight, more preferably 20 to 60% by weight.

The content of the toner binder in the toner of the present invention is preferably 60 to 98% by weight when a dye or pigment is used as a colorant based on the weight of the toner from the viewpoint of low temperature fixability and offset resistance. When using a magnetic powder, it is preferably 25 to 80% by weight.

The toner binder for electrophotographic of the present invention may contain a wax (e) in order to further improve low temperature fixability and offset resistance.
Examples of the wax (e) include polyolefin wax, natural wax, Fishertroph wax, fatty alcohol having 30 to 50 carbon atoms, fatty acid having 30 to 50 carbon atoms, and a mixture thereof.

Examples of the polyolefin wax include an olefin (co) polymer (e-1), an olefin (co) polymer oxide (e-2), and an olefin (co) polymer maleinated product (e-3). , A copolymer (e-4) of an olefin and an unsaturated carboxylic acid and / or an unsaturated carboxylic acid alkyl ester.

Examples of (e-1) include (co) polymers such as ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene and mixtures thereof (for example, polyethylene, polypropylene, ethylene / propylene). Polymers, ethylene / 1-butene copolymers, and propylene / 1-hexene copolymers).
(E-1) includes those obtained by (co) polymerization of olefins (e-1-1) and heat-reduced molded polyolefins (e-1-2).

Examples of (e-1-2) include polyolefins obtained by thermally reducing a polyolefin resin (for example, polyethylene and polypropylene) having a weight average molecular weight (Mw) of 50,000 to 5 million.

Examples of (e-2) include the oxide of the above (e-1).
Oxidation can be carried out by a known method using oxygen and / or ozone or the like, for example, by the method described in US Pat. No. 3,692,877.

As (e-3), the maleic acid-based monomer of the above (e-1) [maleic acid and its derivatives (maleic anhydride; monomethyl maleate, monobutyl maleate, dimethyl maleate, etc., and the like, the number of carbon atoms of maleic acid) 1 to 4 mono or dialkyl ester)] modified products and the like.
The denaturation can be carried out by a known method, for example, by reacting (e-1) with a maleic acid-based monomer by either a solution method or a melting method using a known peroxide catalyst. be able to.

Examples of (e-4) include the above-mentioned olefin and unsaturated carboxylic acid [(meth) acrylic acid, itaconic acid, maleic anhydride, etc.] and / or unsaturated carboxylic acid alkyl ester [(meth) alkyl acrylate (carbon of alkyl). Examples thereof include copolymers with (numbers 1 to 18) esters and alkyl maleates (alkyls having 1 to 18 carbon atoms) esters and the like].
Copolymerization can be carried out by a known method or the like using a known catalyst.

The number average molecular weight of the polyolefin wax is preferably 1,000 to 30,000, more preferably 1500 to 25,000, and particularly 2,000 to 20,000, from the viewpoint of filming to carriers and the like and wax.
The melting point of the polyolefin wax is preferably 50 to 165 ° C, more preferably 60 to 160 ° C, and particularly 65 to 155 ° C, from the viewpoint of filming to carriers and the like and wax.

Examples of the natural wax include carnauba wax, montan wax, paraffin wax and rice wax.
Examples of the Fischer-Tropsch wax include Sazole wax H1.
Examples of the aliphatic alcohol having 30 to 50 carbon atoms include toriacontanol.
Examples of the fatty acid having 30 to 50 carbon atoms include triacontane carboxylic acid.

Of these, preferred are polyolefin waxes, natural waxes, Fischer-Tropsch waxes and mixtures thereof, more preferably thermoreduced polyethylenes, thermoreduced polypropylenes, paraffin waxes and Fischer-Tropsch waxes.

The content of the wax (e) in the toner of the present invention is preferably 0 to 10% by weight, more preferably 1 to 8% by weight, based on the weight of the toner from the viewpoint of low temperature fixability and offset resistance.

The method for mixing the styrene (co) polymers (a), (b) and (c) is not particularly limited, but a method for separately polymerizing (a), (b) and (c) and mixing them in a solution state, respectively. Examples thereof include a method of polymerizing another polymer in the presence of the polymer.

To obtain a toner binder containing the wax (e) and / or other resin, (a), (b), and (c), and the wax (e) and / or other resin are mixed in a solution form. Either the method or the method of melting and mixing in a twin-screw extruder or a compounding kettle capable of heating and stirring may be used, and (a), (b) and (c) may be mixed in the presence of wax (e) and / or other resin. May be manufactured.

Examples of the charge control agent include metal-containing azo dyes, niglosin dyes and quaternary ammonium salt compounds.
The content of the charge control agent in the toner of the present invention is preferably 0 to 5% by weight, more preferably 1 to 5% by weight, based on the weight of the toner from the viewpoint of chargeability.

Examples of the fluidizing agent include known ones such as colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.
The content of the fluidizing agent in the toner of the present invention is preferably 0 to 5% by weight from the viewpoint of chargeability.

Examples of the toner manufacturing method include known kneading and pulverizing methods. For example, the toner constituents are dry-blended using a Henchel mixer or the like, melt-kneaded at 70 ° C to 190 ° C using a twin-screw extruder or the like, then coarsely pulverized, and finally a jet crusher or the like is used. It is made into fine particles by using and further classified to obtain fine particles having a volume average particle size (D50) of 5 to 15 microns.
D50 is measured using a Coulter counter [for example, trade name: Multisizer III (manufactured by Beckman Coulter)].
Further, in the above method, the fluidizing agent can also be used by mixing (externally adding) the toner after making the toner into fine particles.

If necessary, the toner is mixed with carrier particles such as ferrite whose surface is coated with glass beads and / or a resin (acrylic resin, silicone resin, etc.) and used as a developer. Further, instead of the carrier particles, it can be charged by rubbing against a member such as a charging blade.
The toner is then moved to an electrostatic latent image on the photoconductor and then onto a support (paper, polyester film, etc.).
Further, it is fixed to the support by a known heat roll fixing method or the like and used as a recording material.

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited thereto. Examples 13 and 15 are Reference Examples 1 and 2.

Production Example 1
300 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 180 ° C. in a sealed state with stirring. A mixed solution of 550 parts by weight of styrene, 69 parts by weight of n-butyl acrylate, 6 parts by weight of methacrylic acid, 14 parts by weight of dit-butyl peroxide, and 120 parts by weight of xylene was mixed while controlling the temperature in the autoclave to 180 ° C. It was dropped over 3 hours and polymerized. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a-1). The content of the polymer (a-1) in the solution was 59% by weight.

Manufacturing example 2
300 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 190 ° C. in a sealed state with stirring. A mixed solution of 550 parts by weight of styrene, 5 parts by weight of acrylic acid, 15 parts by weight of di-t-butyl peroxide, and 100 parts by weight of xylene was added dropwise over 3 hours while controlling the temperature in the autoclave to 190 ° C. for polymerization. I let you. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a-2). The content of the polymer (a-2) in the solution was 57% by weight.

Production example 3
A solution containing the polymer (a-3) was obtained in the same manner as in Production Example 2 except that the monomers used were 520 parts by weight of styrene and 35 parts by weight of acrylonitrile. The content of the polymer (a-3) in the solution was 57% by weight.

Production example 4
250 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 160 ° C. in a sealed state with stirring. A mixed solution of 411 parts by weight of styrene, 80 parts by weight of n-butyl acrylate, 9 parts by weight of methacrylic acid, 5 parts by weight of dit-butyl peroxide, and 100 parts by weight of xylene was mixed while controlling the temperature in the autoclave to 160 ° C. It was dropped over 3 hours and polymerized. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a-4). The content of the polymer (a-4) in the solution was 58% by weight.

Production Example 5
320 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 205 ° C. in a sealed state with stirring. A mixed solution of 700 parts by weight of styrene, 22 parts by weight of n-butyl acrylate, 6 parts by weight of di-t-butyl peroxide, and 85 parts by weight of xylene was added dropwise over 3 hours while controlling the temperature in the autoclave to 205 ° C. And polymerized. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a-5). The content of the polymer (a-5) in the solution was% by weight.

Production Example 6
After charging 500 parts by weight of xylene into an autoclave and replacing it with nitrogen, the temperature was raised to 200 ° C. in a sealed state with stirring. A mixed solution of 990 parts by weight of styrene, 10 parts by weight of acrylic acid, 25 parts by weight of di-t-butyl peroxide, and 100 parts by weight of xylene was added dropwise over 3 hours while controlling the temperature inside the autoclave to 200 ° C. for polymerization. I let you. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a-6). The content of the polymer (a-6) in the solution was 61% by weight.

Production example 7
250 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 150 ° C. in a sealed state with stirring. A mixed solution of 785 parts by weight of styrene, 210 parts by weight of n-butyl acrylate, 5 parts by weight of methacrylic acid, 5 parts by weight of di-t-butyl peroxide, and 100 parts by weight of xylene was mixed while controlling the temperature in the autoclave to 150 ° C. It was dropped over 3 hours and polymerized. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a-7). The content of the polymer (a-7) in the solution was 73% by weight.

Production Example 8
After charging 500 parts by weight of xylene into an autoclave and replacing it with nitrogen, the temperature was raised to 200 ° C. in a sealed state with stirring. A mixed solution of 1000 parts by weight of styrene, 57 parts by weight of di-t-butyl peroxide, and 180 parts by weight of xylene was dropped and polymerized over 3 hours while controlling the temperature in the autoclave to 200 ° C. Further, the polymerization was completed by keeping at the same temperature for 1 hour to obtain a solution containing the polymer (a'-8). The content of the polymer (a'-8) in the solution was 57% by weight. The polymer (a'-8) has a weight average molecular weight of less than 3000 and is not the polymer (a).

Production Example 9
200 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 140 ° C. in a sealed state with stirring. A mixed solution of 800 parts by weight of styrene, 200 parts by weight of n-butyl acrylate, 1.5 parts by weight of di-t-butyl peroxide, and 100 parts by weight of xylene was prepared over 3 hours while controlling the temperature in the autoclave to 140 ° C. And dropped, and kept at the same temperature for 1 hour. Further, the temperature was raised to 175 ° C. to complete the polymerization, and a solution containing the polymer (b-1) was obtained. The content of the polymer (b-1) in the solution was 76% by weight.

Production Example 10
200 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 140 ° C. in a sealed state with stirring. A mixed solution of 715 parts by weight of styrene, 270 parts by weight of n-butyl acrylate, 15 parts by weight of acrylic acid, 1.5 parts by weight of di-t-butyl peroxide, and 100 parts by weight of xylene was controlled to 140 ° C. in the autoclave. Then, it was dropped over 3 hours and polymerized. After keeping the temperature at the same temperature for 2 hours, the temperature was raised to 175 ° C. and polymerization was carried out for 1 hour to obtain a solution containing the polymer (b-2). The content of the polymer (b-2) in the solution was 76% by weight.

Production Example 11
100 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 140 ° C. in a sealed state with stirring. A mixed solution of 402 parts by weight of styrene, 100 parts by weight of n-butyl acrylate, 0.6 parts by weight of di-t-butyl peroxide, and 50 parts by weight of xylene was prepared over 3 hours while controlling the temperature in the autoclave to 140 ° C. And dropped to polymerize. After keeping the temperature at the same temperature for 2 hours, the temperature was raised to 175 ° C. and polymerization was carried out for 1 hour to obtain a solution containing the polymer (b-3). The content of the polymer (b-3) in the solution was 75% by weight.

Production Example 12
200 parts by weight of xylene was charged in an autoclave, replaced with nitrogen, and then the temperature was raised to 150 ° C. in a sealed state with stirring. A mixed solution of 810 parts by weight of styrene, 180 parts by weight of n-butyl acrylate, 10 parts by weight of acrylic acid, 9 parts by weight of di-t-butyl peroxide, and 100 parts by weight of xylene was mixed while controlling the temperature in the autoclave to 150 ° C. It was dropped over 3 hours and polymerized. After keeping the temperature at the same temperature for 2 hours, the temperature was raised to 175 ° C. and polymerization was carried out for 1 hour to obtain a solution containing the polymer (b-4). The content of the polymer (b-4) in the solution was 76% by weight.

Production Example 13
To a 4-neck flask, add 1900 parts by weight of water and 100 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol [PVA235 manufactured by Kuraray Co., Ltd.], to which 740 parts by weight of styrene and 260 parts by weight of n-butyl acrylate, 2.2-bis. A mixed solution consisting of 3 parts by weight of (4,4-di-t-butylperoxycyclohexyl) propane was added and stirred to prepare a suspension. After sufficiently replacing the flask with nitrogen, the temperature was raised to 95 ° C. to initiate polymerization. The polymerization was continued at the same temperature, and after confirming that the monomer conversion rate reached 98% after 24 hours, the temperature was raised to 100 ° C. and kept at the same temperature for 2 hours to complete the polymerization. As a post-treatment, it was separated by filtration, washed with water and dried to obtain a polymer (b-5).

Production Example 14
To a 4-neck flask, add 1900 parts by weight of water and 100 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol [PVA235 manufactured by Kuraray Co., Ltd.], to which 750 parts by weight of styrene and 250 parts by weight of n-butyl acrylate, 2.22-bis. A mixed solution consisting of 3 parts by weight of (4,4-di-t-butylperoxycyclohexyl) propane was added and stirred to prepare a suspension. After sufficiently replacing the flask with nitrogen, the temperature was raised to 85 ° C. to initiate polymerization. The polymerization was continued at the same temperature, and after confirming that the monomer conversion rate reached 98% after 24 hours, the temperature was raised to 100 ° C. and kept at the same temperature for 2 hours to complete the polymerization. As a post-treatment, it was separated by filtration, washed with water and dried to obtain a polymer (c-1).

Production Example 15
The polymer (c- 2) was obtained.

Production Example 16
To a 4-neck flask, add 950 parts of water and 50 parts of a 2 wt% aqueous solution of polyvinyl alcohol [PVA235 manufactured by Kuraray Co., Ltd.], to which 385 parts of styrene and 115 parts of n-butyl acrylate, 2.22-bis (4). , 4-Di-t-butylperoxycyclohexyl) A mixed solution consisting of 2 parts of propane was added and stirred to prepare a suspension. After sufficiently replacing the flask with nitrogen, the temperature was raised to 95 ° C. to initiate polymerization. The polymerization was continued at the same temperature, and after confirming that the conversion rate became 98% after 24 hours, the temperature was raised to 100 ° C. and kept at the same temperature for 2 hours to complete the polymerization. As a post-treatment, the polymer (c-3) was obtained by filtration, washing with water and drying.

Production Example 17
To a 4-neck flask, add 1900 parts by weight of water and 100 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol [PVA235 manufactured by Kuraray Co., Ltd.], and add 710 parts by weight of styrene, 290 parts by weight of n-butyl acrylate, and di-t-butyl. A mixed solution consisting of 3 parts by weight of peroxyhexahydroterephthalate was added and stirred to prepare a suspension. After sufficiently replacing the flask with nitrogen, the temperature was raised to 85 ° C. to initiate polymerization. The polymerization was continued at the same temperature, and after confirming that the monomer conversion rate became 80%, the temperature was raised to 95 ° C. and kept at the same temperature for 5 hours to complete the polymerization. As a post-treatment, it was separated by filtration, washed with water and dried to obtain a polymer (c-4).

Production Example 18
A polymer (c-5) was obtained in the same manner as in Production Example 14, except that the monomers used were 720 parts by weight of styrene and 280 parts by weight of n-butyl acrylate.

Production Example 19
To a 4-neck flask, add 1900 parts by weight of water and 100 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol [PVA235 manufactured by Kuraray Co., Ltd.], and 710 parts by weight of styrene and 290 parts by weight of n-butyl acrylate, 2.2-bis. A mixed solution consisting of 3 parts by weight of (4,4-di-t-butylperoxycyclohexyl) propane was added and stirred to prepare a suspension. After sufficiently replacing the flask with nitrogen, the temperature was raised to 90 ° C. to initiate polymerization. The polymerization was continued at the same temperature, and after confirming that the monomer conversion rate reached 98% after 24 hours, the temperature was raised to 100 ° C. and kept at the same temperature for 2 hours to complete the polymerization. As a post-treatment, it was separated by filtration, washed with water and dried to obtain a polymer (c-6).

Production Example 20
To a 4-neck flask, add 1900 parts by weight of water and 100 parts by weight of a 2% by weight aqueous solution of polyvinyl alcohol [PVA235 manufactured by Kuraray Co., Ltd.], and 705 parts by weight of styrene and 295 parts by weight of n-butyl acrylate, 2.2-bis. A mixed solution consisting of 3 parts by weight of (4,4-di-t-butylperoxycyclohexyl) propane was added and stirred to prepare a suspension. After sufficiently replacing the flask with nitrogen, the temperature was raised to 80 ° C. to initiate polymerization. The polymerization was continued at the same temperature, polymerized to a monomer conversion rate of 60%, and then heated to 85 ° C. to continue the polymerization. After confirming that the monomer conversion rate was 98%, the temperature was raised to 100 ° C. and kept at the same temperature for 2 hours to complete the polymerization. As a post-treatment, the mixture was separated by filtration, washed with water, and dried to obtain a polymer (c-7).

The weight average molecular weight and SP value of the polymers obtained in Production Examples 1 to 13 are as shown in Table 1. The weight average molecular weight of the polymer was measured under the above conditions, and the SP value was calculated by the above method.

Table 1 shows the physical characteristics of the polymer (solid content obtained by desolving the polymer solution) obtained in each production example and comparative production example.

Example 1
The autoclave contains 1050 parts by weight of the solution containing the polymer (a-1) (619 parts by weight as the polymer (a-1)) and 120 parts by weight of the solution containing the polymer (b-1) (polymer (b-). 91 parts by weight as 1) and 290 parts by weight of the polymer (c-1) (290 parts by weight as the polymer (c-1)) were charged and uniformly dissolved under xylene reflux. Next, the temperature was raised to 170 ° C. while distilling off xylene, and then the pressure was reduced. Solvent removal was continued at a pressure of 1 kPa or less, and it was confirmed by gas chromatography that the xylene content in the resin was 400 ppm or less, and a toner binder (TB-1) was obtained.

Example 2
The polymer (solution) to be used is 1065 parts by weight of the solution containing the polymer (a-2) (607 parts by weight as the polymer (a-2)) and 188 parts by weight of the solution containing the polymer (b-2). 144 parts by weight of the polymer (b-2)), 100 parts by weight of the polymer (c-1) (100 parts by weight of the polymer (c-1)), 150 parts by weight of the polymer (c-2) (c-2). A toner binder (TB-2) was obtained in the same manner as in Example 1 except that the polymer (c-2) was 150 parts by weight).

Example 3
1092 parts by weight of the solution containing the polymer (a-1) (644 parts by weight as the polymer (a-1)), 80 parts by weight of the solution containing the polymer (b-2) (61 as the polymer (b-2)) A toner binder (TB-3) was obtained in the same manner as in Example 1 except that the polymer (c-5) was 295 parts by weight (295 parts by weight as the polymer (c-5)). ..

Example 4
852 parts by weight of the solution containing the polymer (a-6) (520 parts by weight as the polymer (a-6)), 197 parts by weight of the solution containing the polymer (b-4) (150 as the polymer (b-4)). By weight), 100 parts by weight of the polymer (b-5) (100 parts by weight as the polymer (b-5)), 230 parts by weight of the polymer (c-7) (230 as the polymer (c-7)) A toner binder (TB-4) was obtained in the same manner as in Example 1 except that the part by weight was used.

Example 5
656 parts by weight of the solution containing the polymer (a-6) (400 parts by weight as the polymer (a-6)), 247 parts by weight of the solution containing the polymer (a-7) (180 as the polymer (a-7)) By weight), 133 parts by weight of the solution containing the polymer (b-3) (100 parts by weight as the polymer (b-3)), 320 parts by weight of the polymer (c-6) (polymer (c-6)). A toner binder (TB-5) was obtained in the same manner as in Example 1 except that the amount was 320 parts by weight.

Comparative Example 1
The polymer (solution) to be used is 970 parts by weight (553 parts by weight as the polymer (a-2)) of the polymer solution (a-2) and 260 parts by weight (polymer) of the polymer solution (b-2). Comparative toner in the same manner as in Example 1 except that (b-2) was 197 parts by weight) and the polymer (c-2) was 250 parts by weight (250 parts by weight as the polymer (c-2)). A binder (RTB-1) was obtained.

Comparative Example 2
The polymer (solution) to be used is 1065 parts by weight (607 parts by weight as the polymer (a-3)) of the polymer solution (a-3) and 175 parts by weight (polymer) of the polymer solution (b-2). (B-2) is 133 parts by weight), the polymer (c-1) is 130 parts by weight (130 parts by weight as the polymer (c-1)), and the polymer (c-2) is 130 parts by weight (polymer). A comparative toner binder (RTB-2) was obtained in the same manner as in Example 1 except that (130 parts by weight as c-2).

Comparative Example 3
The polymer (solution) to be used is 1315 parts by weight (762 parts by weight as the polymer (a-4)) of the polymer solution (a-4) and 26 parts by weight (polymer) of the polymer solution (b-3). Comparative toner in the same manner as in Example 1 except that (b-3) was 19 parts by weight) and the polymer (c-3) was 220 parts by weight (220 parts by weight as the polymer (c-3)). A binder (RTB-3) was obtained.

Comparative Example 4
The polymer (solution) to be used is 1112 parts by weight (701 parts by weight as the polymer (a-5)) of the polymer solution (a-5) and 46 parts by weight (polymer) of the polymer solution (b-2). (B-2) is 35 parts by weight), and the polymer (c-4) is 265 parts by weight (265 parts by weight as the polymer (c-4)). A binder (RTB-4) was obtained.

Comparative Example 5
The polymer (solution) to be used is 1000 parts by weight (570 parts by weight as the polymer (a-8)) of the polymer solution (a-8) and 213 parts by weight (polymer) of the polymer solution (b-3). Comparative toner in the same manner as in Example 1 except that (b-3) was 160 parts by weight) and the polymer (c-2) was 270 parts by weight (270 parts by weight as the polymer (c-2)). A binder (RTB-5) was obtained.

Table 2 shows the composition and analysis results of the toner binders obtained in each Example and Comparative Example.

[Examples 11 to 15, Comparative Examples 11 to 15]
[Creating toner]
88 parts by weight of each of the toner binders (TB-1) to (TB-5) and (RTB-1) to (RTB-5), 7 parts by weight of carbon black [MA100 manufactured by Mitsubishi Kasei Co., Ltd.], low molecular weight polypropylene. [Viscol 660P manufactured by Sanyo Kasei Kogyo Co., Ltd.] 4 parts by weight and 1 part by weight of the charge adjuster (Spiron Black TRH manufactured by Hodoya Chemical Co., Ltd.) were uniformly mixed with a Henshell mixer FM10B [manufactured by Mitsui Miike Kakoki Co., Ltd.]. After that, it is kneaded with a twin-screw extruder [PCM30, manufactured by Ikekai Co., Ltd.] with a resin temperature of 140 ° C., and the cooled material is finely crushed with a jet crusher [Lab Jet LJ, manufactured by Nippon Pneumatic Industries Co., Ltd.]. It was classified by a dispersion separator [MDS-II, manufactured by Nippon Pneumatic Industries, Ltd.]. Then, 100 parts by weight of the toner particles and 1.0 part by weight of colloidal silica (Aerosil R972 manufactured by Nippon Aerosil) are uniformly mixed, and the toners (T-1) to (T-5) of the present invention having a volume average particle size of 9 μm are mixed. And comparative toners (RT-1) to (RT-5) were obtained.
The volume average particle size was measured with a Coulter counter (Multisizer TM3, manufactured by Beckman Coulter).

[Test example]
The toner test method is as follows.
(1) Minimum fixing temperature 30 parts by weight of the evaluation sample (toner) and 800 parts by weight of the ferrite carrier (F-150, manufactured by Powdertech) are uniformly mixed to obtain a two-component developer, which is then subjected to the following test. bottom.
The unfixed image developed using a commercially available monochrome copier [AR5030, manufactured by Sharp Corporation] was modified from the fixing unit of the commercially available monochrome copier [SF8400A, manufactured by Sharp Corporation] to make the heat roller temperature variable. It was fixed at a process speed of 145 mm / sec with a fixing machine. An image with an image density (ID) = 0.6 measured by RD-19 manufactured by GretagMacbeth is rubbed by a Gakushin-type friction fastness test (rubbing with paper) with 5 round trips, and the fixing rate (fixation rate). The heat roller temperature at which ID × 100 after friction / ID before friction) was 70% or more was defined as the minimum fixing temperature.
It is good if the minimum fixing temperature is 135 ° C. or lower.

(2) Hot offset generation temperature The fixing was performed in the same manner as in (1) above, and the presence or absence of hot offset in the fixed image was visually determined. The temperature at which hot offset began to occur was defined as the hot offset generation temperature.
It is good when the hot offset generation temperature is 235 ° C. or higher.

(3) Image stability Similar to (1) above, continuous copying was performed using a commercially available monochrome copying machine [AR5030, manufactured by Sharp Corporation] as a two-component developer, and the change in image quality was evaluated according to the following criteria.
The image stability is good when it is ⊚ and ◯.
⊚: There is no change in image quality and no fog even after copying 10,000 sheets.
◯: Fog has occurred after copying 10,000 sheets.
Δ: Fog has occurred after copying 6,000 sheets.
X: Fog has occurred after copying 2,000 sheets.
Table 2 shows the evaluation results for each of the toners (T-1) to (T-5) and (RT-1) to (RT-5).

As shown in Table 2, the toners (T-1) to (T-5) of the present invention according to the toner binders for electrophotographic (TB-1) to (TB-5) of the present invention have excellent low temperature fixability. It has hot offset resistance and image stability. On the other hand, the comparative toners (RT-1) to (RT-5) using the comparative toner binders (RTB-1) to (RTB-5) have a narrow fixing temperature range and fog, resulting in image stability. It was inferior. By using the toner binder of the present invention as described above, it is possible to obtain a toner having a wide fixing temperature range and excellent toner image stability.

The toner binder for electrophotographic of the present invention can have a high level of fixability and hot offset resistance as a toner, and can obtain a toner having excellent image stability when used for a long period of time. , Extremely useful for electrostatic recording and electrostatic printing.

Claims (2)

A styrene (co) polymer (a) having a weight average molecular weight of 3,000 or more and 30,000 or less, a styrene (co) polymer (b) having a weight average molecular weight of more than 30,000 and 500,000 or less, and a weight average molecular weight of 500,000 or more. a large 1.2 million following styrene (co) electrophotographic toner binder containing the polymer (c), in any combination of (a) and (b) and (b) and (c), SP value The absolute value of the difference between (a) and (c) is 0.00 to 0.30, and the absolute value of the difference between the SP values is 0.15 to 0.30 in the combination of (a) and (c).
The weight ratio [(a): (b): (c)] of the styrene (co) polymer (a), the styrene (co) polymer (b) and the styrene (co) polymer (c) is (52 to 65). ): (6 to 25): (23 to 32), and the loss elastic modulus G "(120) (unit Pa) at a temperature of 120 ° C. and the storage elastic modulus G'(180) (unit Pa) at a temperature of 180 ° C. Is an electrophotographic toner binder satisfying the following relational expressions (1) and (2).
28000 ≤ G "(120) ≤ 60000 (1)
5000 ≤ G'(180) ≤ 10000 (2) A toner containing the electrophotographic toner binder according to claim 1 and a colorant.