JP2005202421A - Resin for toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin for a toner which is excellent in fixing properties, non-offset properties, blocking resistance and image stability. <P>SOLUTION: The resin for the toner is a polymer comprising (a) an aromatic vinyl unit, (b) a (meth)acrylic-based compound unit and (c) a multi-functional compound unit and containing 5 to 60% of a tetrahydrofuran (THF) insoluble portion of a glass transition temperature 50 to 70°C and ≤5wt% secondary flocculation object of 16 mesh oversize. The molecular weight of the maximum peak in a molecular weight distribution by gel permeation chromatography of a TFH soluble portion is ≤20,000; the weight average degree of polarization (Pw) is ≤180; the Pw ranges Pw≤-3.25X+180 in the case of the the THF insoluble portion <40% and ranges Pw≤-0.25X+60 in the case of the the THF insoluble portion ≥40% (where X represents the insoluble portion (%) of the THF). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a resin useful as a dry toner used in printers, copiers, facsimiles, and the like in electrophotographic and electrostatic printing methods, and more specifically in fixing property, non-offset property, blocking resistance, and image stability. The present invention relates to an excellent toner resin.

  Copiers, printers, and the like have been printing at higher speeds year by year, and toners and binder resins have been improved year by year. For example, when charging is generated in the development process, the toner and the carrier are vigorously stirred and mixed according to the printing speed, and the fixing temperature is lowered in the fixing process. In other words, as the required performance, the toner and toner resin improve the low-temperature fixability as the fixing temperature decreases, improve the charging stability to obtain a stable image, and block blocking resistance to prevent the toner during storage from solidifying There are improvements.

  In order to lower the fixing temperature and improve the fixability, it is necessary to lower the molecular weight of the resin. However, in this case, there is a problem that the non-offset property becomes poor with a decrease in molecular weight, and a problem that the glass transition temperature of the resin is decreased with a decrease in molecular weight and the blocking resistance is deteriorated.

  In the case of a styrene- (meth) acrylic acid ester-based resin, in order to reduce the molecular weight, it is necessary to increase the polymerization temperature in the production process, and when the resin is further obtained by suspension polymerization, When the polymerization temperature is increased, the polymer floats on the reaction liquid surface in relation to the reaction pressure, so-called floating polymer is generated, and a secondary aggregated polymer is generated.

  For this reason, in order to prevent the formation of this secondary aggregate, a method using a large amount of a dispersant has been adopted, but there is a problem that the image stability of the toner is inferior due to the use of a large amount of the dispersant. The secondary agglomerated polymer has a problem that a large amount of a dispersant is attached to the surface, and it is difficult to wash and remove the polymer, resulting in poor image stability.

  The present invention has been made to solve the above-described drawbacks, and the object of the present invention is to obtain a toner excellent in fixing property, non-offset property, blocking resistance, and image stability. Another object is to provide a resin for toner.

  As a result of diligent studies to achieve the above object, the present inventors have found that a polymer containing aromatic vinyl, a (meth) acrylic compound and a polyfunctional compound as polymer components and having specific physical properties The inventors have found that the object can be achieved and completed the present invention.

  That is, the present invention includes (a) aromatic vinyl unit, (b) (meth) acrylic compound unit, (c) divinylbenzene, divinylnaphthalene, ethylene glycol di (meth) acrylate, di (meth) acrylic. Triethylene glycol acid, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and bisphenol A A polymer composed of at least one polyfunctional compound unit selected from di (meth) acrylic acid as a derivative, having a glass transition temperature of 50 to 70 ° C., and 5 secondary aggregates on a 16 mesh network. % By weight or less, containing 5 to 60% of tetrahydrofuran insoluble, and soluble in tetrahydrofuran When the molecular weight of the maximum peak in the molecular weight distribution by gel permeation chromatography is 20,000 or less, the weight average degree of polymerization (Pw) is 180 or less, and Pw is less than 40% of tetrahydrofuran insoluble matter, Pw ≦ −3.25X + 180, and when tetrahydrofuran insoluble content is 40% or more, Pw ≦ −0.25X + 60 (however, X in the formula represents the amount of insoluble content (%) of tetrahydrofuran). It is a characteristic resin for toner.

  The toner resin of the present invention having the structure as described above is excellent in fixability, non-offset property, anti-blocking property, image stability, printer for electrophotography, electrostatic printing method, copying machine, facsimile, etc. It is extremely useful as a toner resin. Furthermore, since the resin for toner of the present invention is obtained by suspension polymerization under specific conditions, there are few residual monomers in the resin, and no odor is generated even during kneading during tonerization and heating during copying. It has excellent characteristics.

Hereinafter, the present invention will be described in detail.
The resin for toner of the present invention is a polymer comprising (a) an aromatic vinyl unit, (b) a (meth) acrylic compound unit, and (c) a polyfunctional compound unit.
Examples of the aromatic vinyl used in the present invention include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichloro. Styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, pt-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, p Examples include -n-decyl styrene, pn-dodecyl styrene, α-methyl styrene, and the like, and styrene is particularly preferable. These aromatic vinyls are used alone or in combination of two or more.

  Examples of the (meth) acrylic compound used in the present invention include (meth) acrylic acid (meaning acrylic acid or methacrylic acid, the same shall apply hereinafter), ethyl (meth) acrylate, methyl (meth) acrylate. , N-butyl (meth) acrylate, isobutyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, (meth) Examples include 2-ethoxyethyl acrylate, 2-methoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, glycidyl methacrylate, cyclohexyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, and the like. , Methacrylic acid, methyl methacrylate, (meta Acrylate n- butyl is especially preferred. These (meth) acrylic compounds are used alone or in combination of two or more.

  The polyfunctional compound used in the present invention is a component that crosslinks the resulting resin, and is a compound having two or more ethylenically unsaturated groups in one molecule. Examples include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and di (meth). It is a polyfunctional compound selected from polyethylene glycol acrylate, dipropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and di (meth) acrylic acid as a bisphenol A derivative. For this, divinylbenzene, 1,3-butylene glycol dimethacrylate, and ethylene glycol dimethacrylate are particularly preferred. These polyfunctional compounds are used alone or in combination of two or more.

  The amount of the aromatic vinyl unit (a) and the (meth) acrylic compound unit (b) in the copolymer is not particularly limited as long as it is contained so that the Tg of the toner resin is 50 to 70 ° C. The aromatic vinyl unit (a) needs to contain an amount of 50% by weight or more, preferably 52% by weight or more in the total amount with the (meth) acrylic compound unit (b). . This is because when the content of the aromatic vinyl unit (a) is less than 50% by weight, the moisture resistance of the toner is lowered.

  Moreover, it is preferable that the aromatic vinyl unit (a) has the same content in the THF-insoluble portion and the THF-soluble portion constituting the toner resin. Further, in the THF-insoluble and THF-soluble components, the content of the aromatic vinyl unit (a), the aromatic vinyl unit (a), the (meth) acrylic compound unit (b), and the polyfunctional compound unit (c It is more preferable that the composition ratios of This is because, during toner kneading, the effect of improving the mixing stability with the THF-insoluble matter and improving the image stability can be obtained.

  The amount of the polyfunctional compound unit (c) is 0.4 to 5% by weight with respect to the total amount of the aromatic vinyl unit (a) and the (meth) acrylic compound unit (b). More preferably, it is 0.5 to 4.5% by weight. If the amount is less than 0.4% by weight, the amount of insoluble THF in the resin tends to decrease, and the non-offset property of the toner tends to decrease. On the other hand, if the amount exceeds 5% by weight, the amount of THF insoluble increases. There is a tendency.

  The toner resin of the present invention composed of the above components has a THF insoluble content of 5 to 60%, preferably 10 to 50%, more preferably 10 to 40%, and a maximum peak in the molecular weight distribution by GPC of THF soluble content. Has a molecular weight of 20,000 or less, preferably 18,000 or less, more preferably 10,000 or less, and a weight average degree of polymerization (Pw) of 180 or less, preferably 160 or less, more preferably 100 or less.

this is,
(1) A toner using a resin having a THF insoluble content of less than 5% is inferior in non-offset property, while a toner using a resin in excess of 60% is inferior in fixing property.
(2) Toner using a resin having a maximum peak molecular weight of more than 20,000 in the molecular weight distribution by GPC of THF-soluble matter has a low fixability.
(3) A toner using a resin having a weight average degree of polymerization (Pw) exceeding 180 has poor fixability.
This is because of such reasons.

  In the toner resin of the present invention, the weight average degree of polymerization (Pw) is particularly important from the viewpoint of toner fixability, and the weight average degree of polymerization (Pw) needs to be 180 or less. This is because when the weight average degree of polymerization (Pw) exceeds 180, the toner fixing property is lowered, and is preferably in the range of 160 or less. In the present invention, the weight average degree of polymerization (Pw) is the weight average degree of polymerization of the linear portion when the reaction rate of the monomer used for the polymerization is 100%, and is calculated by the calculation formula described later. It can be calculated.

  In the present invention, in order to improve the fixing property and the non-offset property, it is preferable to select a value of the weight average polymerization degree (Pw) corresponding to the THF insoluble matter. That is, when the THF-insoluble content is less than 40%, the range is Pw ≦ −3.25X + 180, and when the THF-insoluble content is 40% or more, the range is Pw ≦ −0.25X + 60 (where X in the formula is insoluble in THF) The weight average degree of polymerization (Pw) is preferably satisfied so that the amount (%) is satisfied.

  This is because when the THF insoluble content is less than 40%, the softening temperature of the resin is relatively low, so the toner has good fixability, but the non-offset becomes inferior, and the THF insoluble content exceeds 40%. This is because the fixing temperature is lowered because the softening temperature of the resin is rapidly increased. That is, in order to prevent the tendency of the toner fixability to decrease as the THF-insoluble content increases, it is necessary to decrease the value of the weight average polymerization degree (Pw) as the THF-insoluble content increases.

  In the present invention, the glass transition temperature (hereinafter abbreviated as Tg) of the resin for toner is preferably 50 to 70 ° C, more preferably 53 to 67 ° C, and more preferably 55 to 65 ° C. This is because toner using a resin having a Tg of less than 50 ° C. tends to cause deterioration of the image due to fusion of the toner in the charging process, or to cause contamination of the roll due to adhesion of the toner to the developing roll. On the other hand, the toner using a resin having a temperature higher than 70 ° C. tends to have a low fixability.

  In the present invention, the softening temperature of the resin for toner is preferably 110 to 190 ° C, more preferably 115 to 185 ° C, and more preferably 120 to 155 ° C. This is because the toner using a resin having a softening temperature of less than 110 ° C. has improved fixability, but the cohesive strength of the resin is extremely lowered and sufficient non-offset property tends to be not obtained. This is because a toner using a resin having a temperature higher than 0 ° C. has improved non-offset properties but has a tendency to extremely decrease fixing properties.

  In the present invention, the acid value of the resin for toner is preferably 0.1 to 20 mgKOH / g, more preferably 0.1 to 19 mgKOH / g. This is because a resin having an acid value of less than 0.1 mgKOH / g is very difficult to produce, whereas a toner using a resin having an acid value of more than 20 mgKOH / g tends to have low moisture resistance.

  In the toner resin of the present invention, the residual monomer amount is preferably 1000 ppm or less, more preferably 600 ppm or less, more preferably 200 ppm or less, and particularly preferably 100 ppm or less. This is because a toner using a resin having a residual monomer amount exceeding 1000 ppm tends to generate odor during heating such as melt-kneading and copying at the time of toner formation, and image stability tends to be lowered. is there.

  In the toner resin of the present invention, the secondary aggregate on the 16 mesh screen is preferably 5% by weight or less, more preferably 4% by weight or less. This is because the toner using a resin in which the secondary aggregate on the 16 mesh screen exceeds 5% by weight tends to cause fog in the image.

  Furthermore, in the present invention, the storage elastic modulus (G ′) of the toner resin is 4,000 or more and the loss elastic modulus (G ″) is 4,000 or more from the viewpoint of toner fixing property and non-offset property, and Tan δ (value obtained by dividing loss elastic modulus by storage elasticity (G ″ / G ′)) is preferably less than 1.

  A toner using a resin having a storage elastic modulus of less than 4,000 is inferior in non-offset property, and a particularly preferable storage elastic modulus is 5,000 or more. In addition, a toner using a resin having a loss elastic modulus of less than 4,000 has poor fixability, and a particularly preferable loss elastic modulus is 4,500 or more. Further, a toner using a resin having a Tan δ exceeding 1.0 has poor fixability, and a particularly preferable Tan δ is 0.9 or less.

  The storage elastic modulus (G ′), loss elastic modulus (G ″) and Tan δ referred to in the present invention are parallel plates with a diameter of 25 mm and are measured at a temperature of 175 to 177 ° C. and a rheometer RDA700 manufactured by Rheometrics. The value obtained by measuring viscoelasticity at 1 Hz and strain 0.28%.

  The toner resin of the present invention having the above physical properties is produced by a suspension polymerization method. As a method for producing a resin for toner, there are polymerization methods such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method and the like in addition to suspension polymerization. Solvent that emits odor and image stability is poor. Emulsification polymerization method reduces the moisture resistance due to a large amount of emulsifier remaining in the resulting resin. In other words, the toner resin for the purpose of the present invention cannot be produced.

In the production of the resin for toner of the present invention, the above monomer mixture, polymerization initiator, emulsifier, emulsification aid and deionized water are charged into a reaction vessel and subjected to suspension polymerization. The relationship between the saturated vapor pressure Pθ (kg / cm ² ) of water at the reaction temperature T (° C.) and the reaction pressure P (kg / cm ² ) is controlled so as to satisfy the following formulas (I) and (II). This is very important.

  P-Pθ ≧ 0.3 (I)

  T ≧ 100 (II)

In the above formula (I), when P-Pθ is less than 0.3 (kg / cm ² ), a floating polymer is generated in which the polymer floats on the reaction liquid surface during suspension polymerization. Secondary agglomerates (polymer secondary agglomerates that do not pass through a 16 mesh screen). The toner of the resin containing the secondary agglomerated polymer has a lot of fog on the image and the image stability is lowered. A preferable range of P−Pθ is P−Pθ ≧ 0.5.

  The reaction temperature T shown in the above formula (II) is 100 ° C. or higher, and particularly preferably 105 ° C. or higher. When the reaction temperature T is less than 100 ° C., the molecular weight of the polymer is increased and the fixing property of the toner is deteriorated.

  Furthermore, in the suspension polymerization of the present invention, it is preferable that the temperature raising time from the room temperature to the reaction temperature is in the range of 20 to 90 minutes. This is because if less than 20 minutes, the resin is not sufficiently crosslinked, and if the temperature is raised beyond 90 minutes, the molecular weight of the resin cannot be reduced.

  As the polymerization initiator used in the suspension polymerization of the present invention, a peroxide polymerization initiator is preferable. As the peroxide polymerization initiator to be used, those having a 10-hour half-life in the range of 60 to 110 ° C. are preferably used.

  Examples thereof include, for example, lauryl peroxide (62 ° C.) (the temperature in () indicates a 10-hour half-life temperature, the same applies hereinafter), cumerperoxy octoate (68 ° C.), benzoyl peroxide (74 ° C. ), T-butylperoxy (2-ethylhexanoate) (72.5 ° C.), m-toluoyl peroxide (73 ° C.), t-butyl peroxyisobutyrate (78 ° C.), 1,1- Bis (t-butylperoxy) 3,3,5-trimethylcyclohexane (90 ° C.), t-butyl peroxylaurate (96 ° C.), cyclohexanone peroxide (97 ° C.), t-butyl peroxyisopropyl carbonate (98 ° C.), t-butyl peroxyacetate (102 ° C.), t-butyl peroxybenzoate (104 ° C.), di-t-butyl Over oxy isophthalate rate (107 ° C.) and others as listed, lauryl peroxide, benzoyl peroxide, t- butyl peroxy isopropyl carbonate, and t-butyl peroxy benzoate are preferably used.

  These polymerization initiators are used singly or in combination of two or more, but in the present invention, using two kinds of polymerization initiators having different half-life temperatures reduces the residual monomer, This is particularly preferable because it brings about an effect of increasing the glass transition temperature.

  Although the usage-amount of a polymerization initiator is not specifically limited, It is the range of 1.5 to 10 weight% with respect to the total amount of the monomer used for superposition | polymerization. Preferably it is the range of 1.5 to 9 weight%.

  Further, the dispersant used in the suspension polymerization of the present invention is a dispersant used in ordinary suspension polymerization. For example, polyvinyl alcohol, sodium polyacrylate dispersant, polyether dispersant, or the like can be used. it can. Further, the dispersion aid used in the suspension polymerization of the present invention may be a dispersion aid used in ordinary suspension polymerization. For example, sodium sulfate, sodium carbonate, calcium carbonate, manganese sulfate, hydrogen peroxide solution, boron An acid or the like can be used.

  The amount of deionized water used for the polymerization component in the suspension polymerization of the present invention is preferably in the range of 1.2 to 2.5, more preferably in the range of 1.4 to 2.3, as a polymerization ratio. is there.

  Next, in the production method of the present invention, after the suspension polymerization is completed, it is preferable to perform an alkali treatment at a temperature of 85 ° C. or higher, preferably 88 ° C. or higher. This is because benzoic acid generated due to the polymerization initiator is reduced and the charging stability of the resin is improved. Examples of the alkali used include alkali metal hydroxides such as lithium, sodium, potassium and rubidium, and sodium hydroxide is particularly preferred. The usage-amount of an alkali is 0.1 to 2 weight% with respect to the total amount of an aromatic vinyl and a (meth) acrylic-type compound, Most preferably, it is the range of 0.3 to 1.5 weight%.

  In the production method of the present invention, after the suspension polymerization is performed, the remaining monomer is distilled out together with deionized water at a temperature of 100 ° C. or more before the alkali treatment or simultaneously with distillation. Can be issued. The amount distilled by distillation is in the range of 5 to 30% by weight, particularly preferably 10 to 25% by weight of the amount of deionized water used for the suspension polymerization.

  Next, the bead-shaped polymer treated with alkali is thoroughly washed with deionized water, dehydrated and dried.

  Since the polymerization method of the present invention having the above constitution is a one-stage polymerization, the residual monomer in the resulting resin is as low as about 1000 ppm or less, and therefore, odor is generated even during heating during melt kneading and copying at the time of toner formation. And a toner having excellent image stability can be obtained.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The performance evaluation in the examples was performed using the following method. In the examples, “parts” indicates “parts by weight”.

(1) THF insoluble matter (%)
0.5 g of resin is put in 50 ml of tetrahydrofuran, dissolved by heating at 70 ° C. for 3 hours, filtered through a glass filter with Celite (Johns-Manville Sales, # 545), and sufficiently dried at 80 ° C. with a vacuum dryer. The value obtained by dividing the weight when dried by the initial weight was used.

(2) Weight average degree of polymerization (Pw)
The weight average degree of polymerization (Pw) was calculated by the following formula (III).
Pw = 1 / ρPc (III)
However, Pc is the reaction rate of the monomer used for polymerization, ρ is A for the molar part of the aromatic vinyl, B for the molar part of the (meth) acrylic compound, and C for the molar part of the polyfunctional compound. The value is obtained by the following formula (IV).
ρ = (number of functional groups × C) / [A + B + (number of functional groups × C)] (IV)

(3) Molecular weight measurement of maximum peak in molecular weight distribution by GPC (gel permeation chromatography) Using Tosoh Co., Ltd., GPC HCL-8020, it was counted as a calibration curve created with a monodisperse polystyrene standard sample The molecular weight was calculated and the molecular weight distribution was determined from the relationship with the numerical value, and the maximum peak was determined as the molecular weight.
A sample obtained by dissolving and extracting the resin with a solvent (tetrahydrofuran) was used.

(4) Tg (glass transition temperature) (° C)
Using a differential scanning calorimeter manufactured by Shimadzu Corporation, the contact point between the tangent line of the endothermic curve near Tg when measured at a temperature increase of 10 ° C./min and the base line was defined as Tg.

(5) Softening temperature (° C)
Using a flow tester (CFT-500) manufactured by Shimadzu Corporation, when the sample has flown half out under conditions of a nozzle of 1.0 mmφ × 10 mmL, a load of 30 kgf, a temperature increase of 3 ° C./min, and a sample amount of 1.0 g Was defined as the softening temperature (° C.).

(6) Acid value (mg / KOH / g)
The resin was heated and dissolved in toluene, cooled, and titrated with a KOH solution.

(7) Secondary aggregate on 16 mesh network (%)
A value obtained by dividing 50 g of a resin sample on a 16-mesh sieve and gently vibrating for about 4 hours and dividing the weight of the polymer remaining on the mesh of the 16-mesh sieve by the initial weight was used.

(8) Measurement of storage elastic modulus (G ′), loss elastic modulus (G ″), and Tan δ The measurement was performed by the method described in paragraph 0028 above.

(9) Toner fixing property, non-offset property, image stability Using a copying machine with a fixing speed of 250 mm / sec and a variable fixing temperature, the fixing property, non-offset property, and image stability were evaluated. .

(A) Fixability The initial density was set to 1.2 to 1.3, and the ratio between the density after rubbing with sand eraser and the initial density was determined, and the temperature at which it exceeded 85% was defined as the fixing temperature.
○… Excellent (fixing temperature less than 170 ° C)
Δ: Slightly inferior (fixing temperature: 170 to 180 ° C.)
X: Inferior (fixing temperature 181 ° C or higher)

(B) Non-offset property It evaluated by offset generation temperature.
○… Excellent (offset generation temperature 210 ° C or higher)
Δ: Slightly inferior (offset generation temperature: 200 to 210 ° C.)
X: Inferior (offset generation temperature less than 200 ° C)

(C) Image stability 20,000 sheets were printed by the above copying machine, and the image quality was visually judged.
○… Excellent △… Some fogging ×… Many fogging

(10) Toner blocking resistance 5 g of toner was placed in a 50 ml glass sample bottle, left in a hot air dryer at 50 ° C. for 70 hours, cooled to room temperature, and the degree of aggregation was observed.
○… Excellent (When the sample is turned upside down and tapped, the toner is uniformly dispersed.)
Δ: Slightly inferior (If the sample is inverted and tapped three times, the toner is uniformly dispersed.)
X: Inferior (Even if the sample is turned upside down and subjected to strong vibration, the toner does not aggregate and disperse.)

[Example 1]
220 parts of deionized water, 0.15 part of polyvinyl alcohol (saponification degree 88%) and 0.03 part of hydrogen peroxide were thoroughly mixed and charged into a reaction vessel equipped with a distillation column and a stirrer. Next, styrene, n-butyl acrylate and 1,3-butylene glycol dimethacrylate in the amounts shown in Table 1 were added and stirred at a rotational speed of 350 rpm.

  Next, after the amount of the polymerization initiator shown in Table 1 was added, stirring was continued for about 1 hour, and the reaction vessel was closed and the temperature of the reaction system was started. After starting the temperature increase, the pressure and temperature in the reaction system were gradually increased, and the temperature in the reaction system reached the reaction temperature shown in Table 1 in about 45 minutes while controlling the reaction pressure according to the temperature. The reaction temperature was kept constant, and this condition was maintained for about 4 hours and 30 minutes while controlling the reaction pressure shown in Table 1.

  Next, the temperature in the reaction system is lowered to 90 ° C., the reaction vessel is brought to normal pressure, the stirring rotation speed is set to 400 rpm, the mixture is heated again, and the temperature in the reaction system is increased to 100 ° C. A mixture of volatilized deionized water and residual monomer was distilled out of the reaction system. About 2 hours after the start of distillation, when the amount of the distillate reached 44 parts, the temperature in the reaction system was lowered to 90 ° C. and 0.5 parts of sodium hydroxide was added. After about 60 minutes, the temperature of the reaction system was cooled to room temperature, and the rotation speed was 100 rpm.

  Next, the resin beads were taken out from the reaction vessel, washed sufficiently with deionized water, dehydrated and dried for about 48 hours with a drier maintained at 50 ° C. to obtain resins R-1 to R-12. Table 2 shows the characteristic values of the obtained resins R-1 to R-12. Resins R-1 to R-2 had the same aromatic vinyl unit (a) content and proportion of each unit in the THF-soluble and THF-insoluble components and the same polymerization composition.

  Next, 91 parts of the above-mentioned resins R-1 to R-12 obtained, 5 parts of carbon black (manufactured by Mitsubishi Kasei Co., Ltd., # 40), polypropylene wax (manufactured by Sanyo Chemical Industries, Ltd., 550P) 4 And 1 part of negative charge control agent (S-34, manufactured by Orient Chemical Co., Ltd.) are thoroughly mixed, and then an internal mixer (manufactured by Kurimoto Steel Co., Ltd.) is used to determine the resin temperature during kneading. The mixture was controlled to be 20 ° C. higher than the softening temperature and kneaded for about 30 minutes. The obtained toner mass was coarsely pulverized and finely pulverized with a jet mill, and then the toner particle size was adjusted using a classifier to obtain toners T-1 to T-12 having a particle size of 5 to 20 μm. Table 3 shows the evaluation results of these toners T-1 to T-12.

  As can be seen from Table 3, when the resins R-1 to R-12 are used as toners, they are excellent in fixing property, non-offset property, blocking resistance and image stability.

[Example 2]
Except that the polymerization composition and polymerization conditions were as shown in Table 4, the same operations as in Example 1 were performed to obtain resins R-13 to R-17. Table 5 shows the characteristic values of the resins R-13 to R-17. The obtained resins R-13 to R-17 had the same content of the aromatic vinyl unit (a) and the ratio of each unit in the THF soluble component and the THF insoluble component, and were the same as the polymerization composition.

  Next, the same operations as in Example 1 were performed using the resins R-13 to R-17, and toners T-13 to T-17 were obtained. Evaluation was performed in the same manner as in Example 1 except that the obtained T-13 to T-17 were used and a copying machine having a fixing speed of 200 mm / second was used. The results are shown in Table 6.

  As can be seen from Table 6, when the resins R-13 to R-17 are used as toners, they are excellent in fixing property, non-offset property, blocking resistance and image stability.

[Comparative Example 1]
Resins R-18 to R-25 were obtained in the same manner as in Example 1 except that the polymerization composition and polymerization conditions were as shown in Table 7. Table 8 shows the characteristic values of the resins R-18 to R-25.

  Next, the same operations as in Example 1 were performed using the resins R-18 to R-25 to obtain toners T-18 to T-25. The same evaluations as in Example 1 were performed using the obtained toners T-18 to T-25. The results are shown in Table 9.

  Resin R-18 had a lot of secondary agglomerates on a 16 mesh screen, so the image stability of the toner was poor. Resin R-19 had poor toner fixability due to its high Tg, molecular weight, THF insoluble content and softening temperature. Resin R-20 was inferior in toner non-offset property due to its low softening temperature and THF-insoluble matter. Resin R-21 had a low Tg, so the toner had poor blocking resistance. Resin R-22 had a high Tg, so the toner fixing ability was poor. Resin R-23 had a low THF insoluble content and a high degree of weight average polymerization (Pw), and therefore the non-offset property and the fixing property were poor. Resin R-24 had a high molecular weight, and Resin R-25 had a high softening temperature and a high THF-insoluble content, so the fixability was poor.

[Comparative Example 2]
A resin R-27 was obtained in the same manner as in Example 2 except that the polymerization composition and polymerization conditions were as shown in Table 10. Table 11 shows the characteristic values of the resin R-27.

  Next, the same operation as in Example 1 was performed using the resin R-27, and thus a toner T-27 was obtained. Using the obtained toner T27, the same evaluation as in Example 2 was performed. The evaluation results are shown in Table 12.

  Resin R-27 had a low THF insoluble content and a low softening temperature, so the non-offset property of the toner was poor.

[Comparative Example 3]
A mixture of 70 parts of styrene, 20 parts of n-butyl acrylate, 10 parts of α-methylstyrene and 8 parts of benzoyl peroxide was added dropwise to 200 parts of toluene at the boiling point over 5 hours, and then for another 3 hours. The polymerization was carried out while maintaining the boiling point. Thereafter, vacuum drying was performed to remove toluene to obtain a low molecular weight polymer. The content of the aromatic vinyl unit (a) in the THF-soluble component of this low molecular weight polymer was 80% by weight.

Next, a homogeneous mixed solution composed of 70 parts of the above low molecular weight polymer, 20 parts of styrene, 24 parts of n-butyl acrylate, 1 part of divinylbenzene and 4 parts of benzoyl peroxide was added to polyvinyl alcohol (saponification degree 88%) 0.8. A resin R-28 containing THF-insoluble matter was obtained by suspending and dispersing in 300 parts of water in which part was dissolved and polymerizing at a polymerization temperature of 80 ° C. for 15 hours. The obtained resin R-28 had a THF soluble content of 33%, a weight average degree of polymerization (Pw) of 101.7, and a molecular weight with a maximum peak in the molecular weight distribution of 8,000.
In addition, the content of the aromatic vinyl unit (a) in the THF-soluble component and the THF-insoluble component of the resin R-28 was 76.4% by weight and 42.4% by weight, respectively.

Next, the same operation as in Example 1 was performed using the resin R-28, and thus a toner T-28 was obtained. When the same evaluation as in Example 1 was performed using this toner T-28, fogging occurred in the obtained image and it was not usable.

Claims (1)

(A) aromatic vinyl unit, (b) (meth) acrylic compound unit, (c) divinylbenzene, divinylnaphthalene, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, di Tetraethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and di (meth) of bisphenol A derivatives A polymer comprising at least one polyfunctional compound unit selected from acrylic acid, having a glass transition temperature of 50 to 70 ° C., and secondary aggregates on a 16 mesh network of 5% by weight or less, Gel permeation containing 5-60% tetrahydrofuran insolubles and tetrahydrofuran solubles Pw ≦ −3.25X + 180 when the molecular weight of the maximum peak in the molecular weight distribution by chromatography is 20,000 or less, the weight average degree of polymerization (Pw) is 180 or less, and Pw is less than 40% insoluble in tetrahydrofuran. When the insoluble content of tetrahydrofuran is 40% or more, the range is Pw ≦ −0.25X + 60 (where X in the formula represents the insoluble content (%) of tetrahydrofuran). resin.