JPH0341469A - Toner for electrostatic image - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a toner used for developing electrostatic images formed in electrophotography, electrostatic photography, electrostatic recording, etc. .

[Prior Art] Generally, an electrostatic image is developed with toner, which is a colored powder, to form a toner image, and this toner image is fixed as it is or after being transferred to a transfer paper or the like.

This)・ner usually consists of a polymer as a binder component,
It is prepared by melt-mixing components consisting mainly of carbon black, other colorants, and charge control agents.

It is well known that the performance of the toner is greatly influenced by the binder components, but the most important physical properties of the toner are low-temperature fixability and offset.
The reality is that there is still no toner that satisfies all of the performance requirements for preventing the gutter phenomenon.

[Problems to be solved by the invention] Low-temperature fixability is an essential performance in terms of image forming efficiency;
On the other hand, an offset phenomenon occurs, i.e., some of the toner components are transferred to the normally used heat roller for fixing, staining the surface of the transfer paper that is fed afterwards, or being further transferred to the pressure roller that is pressed by the heat roller. It is also necessary to prevent the phenomenon of staining the back side of the transfer paper.

Originally, fixing properties and anti-offset properties are contradictory physical properties, but preventing the offset phenomenon while maintaining low-temperature fixing properties is an issue that must be solved together in order to put toner into practical use.

As a countermeasure against this, the applicant has previously developed (a) a carboxyl group-containing acrylic resin, and (b) a molecule containing two cyanato groups.
The present inventor proposed a toner composition comprising a polyfunctional cyanate ester or a prepolymer of the cyanate ester, and (c) a curing catalyst for the resin.

However, as the inventors of the present invention continued to further study the properties of the toner composition, they realized that a more practical product could be obtained by expanding the fixing temperature range of the toner composition. Obtained.

[Means for Solving the Problems] As a result of intensive studies by the present inventors to solve the problems,
The present invention has been completed by discovering that the desired electrostatic image-use 1 to 1-ner can be obtained by using a specific type of two types of resins having different acid values in combination as acrylic resins containing carboxyl groups.

That is, the present invention provides a toner containing a carboxyl group-containing acrylic resin as a binder resin component used for developing an electrostatic image. The acid value ratio (hereinafter simply referred to as acid value ratio) of the higher value resin [I1] is 15 or more and is used in a proportion, and (b) contains 21 m or more of soana) groups in the molecule. A toner for electrostatic images is characterized in that it uses a composition comprising a polyfunctional cyanate ester or a cyanate prepolymer and a curing catalyst (a).

The configuration of the present invention will be explained below.

The carboxyl group-containing acrylic resin used in the present invention is an alkyl ester of acrylic acid or methacrylic acid (hereinafter collectively referred to as (meth)acrylic acid), such as methyl ester, ethyl ester, propyl ester, butyl ester, 2-ethylhexyne. It is a product obtained by copolymerizing various esters such as polyester, lauryl ester, and stearyl ester with unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid, and crotonic acid. In the present invention, copolymerizable monomers other than these may be used as necessary, such as (meth)acrylic acid hydroxyalkyl ester, (meth)acrylic acid alkylene cricol-1, (meth)acrylamide,
(meth)acrylonitrile, noalkylamino(meth)
It is also possible to further copolymerize vinyl esters such as acrylate, styrene, and vinyl acetate. There are no particular restrictions on producing the acrylic resin, and any known means may be employed.

Usually, solution polymerization is carried out in the presence of a radical catalyst using a solvent such as methyl acetate, acetone, benzene, quinolene, toluene, etc., and residual monomers and solvent are removed from the resulting reaction solution to obtain a toner resin.

Further, the glass transition temperature is 30 to 75°C, preferably 45 to 75°C.
70°C, and the weight average molecular weight is 20,000 to 10,000.
It is advantageously used if it is around 0.

The acid values of the resins [I] and [II] are appropriately set by adjusting the copolymerization ratio of the unsaturated carboxylic acids, but usually the acid value of [I] is less than 5Konm9/y, preferably 3-OKOH.
mg/'i to [IJ] acid value 5 KOHmg/g
As mentioned above, it is necessary to control the amount preferably to 6 to 40 KOl 1 mg/g.

[+] and [II] have an acid value ratio of 1.5 or more, preferably 2
Used in combination at the above rate. If it is less than 15, the temperature at which both fixing and non-offset can be achieved will be narrow and impractical.Based on the standard, it is also necessary to mix at a ratio of 0.3 to 0.09, preferably 0.04 to 0.7, and it is outside this range. In this case, it is difficult to obtain the effect of the present application.

Suitable as a polyfunctional cyanoic acid ester containing two or more nanato groups (-0CN) in the molecule of the present invention, which is (b) I&N, to be blended into the above acrylic resin, or the noanatoic ester prebolimer. The general formula (1), R(OCN)n...(
1) (n in the formula is an integer of 2 or more, usually 5 or less,
R is an aromatic organic group which may contain a heterocycle, and the noanato group is bonded to the aromatic ring of the organic group. Specific examples include 1,
3- or 1,4-dinoanatobenzene, 1 3.5-tricyanatobenzene, 1.3- 1.4- 16- 1
8-26- or 2,7-situanatonaphthalene, 1.
．． 36-dolycyanatonaphthalene, 4,4-cyanatobiphenyl, bis(4-cyanatophenyl)methane, bis(3,5-methyl-4-noanatophenyl)methane, 22bis(4-cyanatophenyl)propane ,2,
2-bis(3,5-dichloro-4-cyanatophenyl)
Propano, 2,2-his(3,5-')bromo-4-noanatophenyl)propane, 2,2-bis(3,5-dimethyl-4cyanatophenyl)propane, bis(4-cyanatophenyl)ether , bis(4-cyanatophenyl)dioether, bis(4-cyanatophenyl)sulfone, tris(4-cyanatophenyl)phosphite,
The polyfunctional novolaconane-1- (USP-IPO22P755
1 3.448,079), a polyfunctional polycarbonate cyanate (
USP-4,026,9+. 3; DE-2,611
．． , 796), and h)- poly-
Examples include styrylupyrinanate (USP-4 578439) obtained by reacting hydroxy-styrylpyridine and the like with cyanogen halide. In addition to these, USP-3.553 2443 75540
2, 3.74 [) 348359590 (1 3B
94 4104166946, BP-1.305,96
7, 1, 060.933, DE-1.190.1
84; 1.195, 764, etc. may also be used.

In addition, as a prepolymer obtained by polymerizing the above-mentioned polyfunctional cyanate ester in the presence of a mineral acid, a Lewis acid, a salt such as sodium carbonate or rhodium chloride, a phosphoric acid ester such as tribudylphosphine, etc. Furthermore, it can also be used as a prepolymer with polyfunctional amines.

In the present invention, the blending amount of the component (b) is 0.5 to 10 parts by weight, preferably 10 to 5 parts by weight, particularly 1.0 to 2.5 parts by weight, based on 100 parts by weight of the acrylic 8 resin. It is.

If the blending amount is less than 0.5 parts by weight, it is difficult to obtain the effects of the present invention.
On the other hand, if the amount exceeds IO parts by weight, excessive crosslinking reaction such as an increase in the flow initiation temperature occurs, which is not preferable.

Further, as the catalyst for component (c) E of the present invention, a catalyst that is generally known for the purpose of accelerating the curing of component (a) can be used.

Examples of such compounds include organic peroxides such as hendyl peroxide, lauroyl peroxide, cabryl peroxide, parachloropenzoyl peroxide, and -tert-butyl perphthalate; and azobisnitrile, etc. Azo compounds: 2-methylimidazole, 2-undetulimidazole, 2-heptadenimidazole, 2-phenylimidazole, 2-ethyl-4
Methyl imiguzole, 1-benzyl-2-methylimidazole, 1-propyl-2-methylimidazole, ■cyanoethyl-2-medylimidazole, I-cyanoedyl-2-edylimidazole, l-cyanoethyl-2-undenelimig sol, 1-cyanoethyl-2-phenyl 1 imiguzole, 1-guanoethyl-2-ethyl-4
Imidazoles exemplified by methylimidazole, 1-guanaminoezyro-2-methylimidazole, and further,
Addition of carboxylic acid or its anhydride to these imidazoles, etc. N,N-dimethylbenolamine, N,N-dimethylaniline, N,N-methyltoluidine, N,N-dimethyl-p-anisidine, p-halogeno-NN-1methylaniline, 2-N-edylaniline linoethanol, )/di-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, N. N. Tertiary amines such as N,N-tetramethylbutanecyamine and N-methylpiperidine; phenols such as phenol, quinlenol, cresol, resorcinol, catechol, and phloroglin; lead naphthenate, lead stearate, zinc naphthenate; Organic metal salts such as zinc ocdylate, oleic acid group, stannous lauryl, dibdeltin malate, manganese naphthenate, cobalt naphthenate, iron acetylacetonate, etc., and these organic metal salts are dissolved in hydroxyl group-containing compounds such as phenol and bisphenol. What becomes; SnCl2
, ZnCl, AlCl2, etc., organic tin compounds such as butyltin oxide, dioctyltin oxide, other alkyltin oxides, alkyltin oxides), maleic anhydride, phthalic anhydride, lauric anhydride, pyromellitic anhydride. )・acid, trimellitic anhydride, hexahydrophthalic anhydride, hexahydrophthalic anhydride, etc. Among these catalysts, organometallic salts and organotin compounds such as dibdeltin oxite, dioctyltin oxide, other alkyltins, and alkyltin oxides are particularly preferred.

In addition, the amount of catalyst used is sufficient within the range of catalyst amount in a general sense, for example, 10 wt% or less based on component (a),
It is usually used in an amount of about a few percent.

In preparing the toner of the present invention, the acrylic resin composition described in "-", a colorant, and if necessary a charge control agent, etc. are melt-mixed.In place of the acrylic resin composition,
Melt and mix acrylic resin, (b) 1 minute lff, (c) 1 minute lff, coloring agent, charge control agent, etc. as necessary; add large amounts of component (b) and (c) to acrylic resin. A so-called blended masterbatch is produced, and this is melt-mixed with an acrylic resin, a colorant, and if necessary, a charge control agent, etc.

The blending is preferably carried out using equipment such as an extruder, pressure kneader, or two rolls at a melting temperature of 120 to 180°C and a melting time of about 30 seconds to 5 minutes.

The colorants here include carhoplac, nigron dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, decobon oil red,
Quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate-1.
Examples include lamp black and condenser.

When preparing the toner of the present invention, if necessary, known auxiliary agents such as binder resins other than the acrylic resin that is the main component of the present invention, polyolefin wax, and other waxes may be added.

In addition, when preparing a toner, if a metal-coordinated compound such as phthalocyanine blue is used, component (b) may react with these colorants and a decoloring reaction may occur. It is preferable to use a method such as a composition or a masterbatch that is blended with an acrylic resin in advance.

1. Effect] The present invention provides a toner with an expanded fixing temperature range by using carboxyl group-containing acrylic resins having different acid values.

[Example] The present invention will be described below with reference to Examples. Incidentally, parts and percentages in Examples and the like are based on weight unless otherwise specified.

Production of acrylic resin [+]-] 400 g of toluene and isopropyl alcohol 001 were placed in a four-bottle flask equipped with a stirrer, a thermometer, and a condenser, and the temperature was raised to 90°C, followed by styrene 17
5g, methyl methacrylate 245g, acrylic acid 2=
789 ethylhexyl, 2 g of methacrylic acid, and 5 g of hensyl peroxide dissolved in toluene (5 g of 20% agricultural yield) were added dropwise. 5 g of the same benzoyl peroxide solution as above was added every 2 hours, and the reaction was continued for about 13 hours. The solvent and remaining monomers were removed from the reaction solution according to a conventional method, and the glass transition temperature (measured with Parkinson Elmer DSC Model 7, the same applies hereinafter) was 59°C and the acid value was 2, 4-KO11.
mli/9, melt viscosity 3 at 120°C (measured with Shimadzu Flow Tester CRT-500, measurement conditions, orifice diameter 1 mm, orifice length 10 mm, load 30 kli, the same applies hereinafter) 19000-voice carboxyl A group-containing acrylic resin was obtained.

[+]-2 Methylene 250g, n-butyl acrylate 100g
, methyl methacrylate l 4 8.59, and acrylic acid l 57 were used to polymerize [I:]-1, glass transition temperature 55 ° C, acid value 2, I KOH m9/
A carboxyl group-containing acrylic resin having a melt viscosity of 15,000 voids was obtained.

[I]-3 Styrene 250g, n-butyl acrylate Ioog
, [I]-1 using 150 g of methyl methacrylate
An experiment was conducted according to
A carboxyl group-containing acrylic resin was obtained.

[I]-4 [+1-1, the amount of acrylic acid used was changed to 59 to obtain a carboxyl group-containing acrylic resin with an acid value of 4.9 KOHmg/9.

4 [H]-1 Styrene 170g, methyl methacrylate 225L 2-ethylhexyl acrylate 809, methacrylic acid 25
Glass transition temperature 62°C, acid value 30, 3 KOHmg/ii, I
A carboxyl group-containing acrylic resin having a melt viscosity of 2+000 voids at 20°C was obtained.

[■1-2 Styrene 2652, methyl methacrylate 150g,
Using n-butyl acrylate 809 and 5 g of acrylic acid, the glass transition temperature was 64°C, the acid value was 7, and OKOI (
m&/ 9. A carboxyl group-containing acrylic resin having a melt viscosity of 25,000 voids at 120°C was obtained.

[I]]-3 Using styrene 250g, methyl methacrylate 15M, n-butyl acrylate 90q1 methacrylic acid log, glass transition temperature 61'C1 acid value 11, 9 KO
IImg/9. Melt viscosity at 120°C 23000
A carboxyl group-containing acrylic resin of Boise was obtained.

Examples 1 to 4, Control Examples 1 to 5 0.1% benzoyl peroxide was added as a curing catalyst to the above acrylic resin, and 88 parts of this and 9 parts of carbon black #44 (manufactured by Mitsubishi Kasei Corporation) were added. , Hong) Ron
534 (manufactured by Orient Chemical Industries, Ltd.), 2 parts of Viscol 550P (manufactured by Sanyo Chemical Industries, Ltd.) and 1.3.
5-1-Linoana) and 2 parts of benzene were mixed into powders, and using a twin screw extruder PCM-30 (manufactured by Ikegai Steel)
Cylinder 60°C, 2nd and 3rd cylinder and cylinder head 140°C, shaft rotation speed 100 r, p
, m, Kneading and extrusion were carried out at a feed rate of 200 g/min.

The obtained extrudate was pulverized to the extent that it could pass through a 1 mm sieve, then finely pulverized using a Noel Mill (manufactured by Nippon New Magic Co., Ltd.), and classified using an air classifier to obtain a toner.

Using a mixture of 5 parts of the synthesized Otsunaga) and 95 parts of iron powder TEFV 150/250 (manufactured by Nippon Tetsuko Co., Ltd.), it was printed on plain paper using an electrophotographic copying machine DC-162 (manufactured by Sanda Kogyo Co., Ltd.). The image was transferred, taken out in an unfixed state, and passed between a Teflon-coated hot roll and a rubber-lined backup roll at a speed of 275 mm/sec to fix the image.

The temperature of the hot roll was varied from 170 to 240° C., and the offset property was rated as good (◎) if there was no toner adhesion to the hot roll, and poor (x) if it was noticeable.

In addition, the normal density of the image can be adjusted using mending tape N0810 (
Furthermore, the concentration retention rate was measured using a Macbeth densitometer (manufactured by Macbeth) and was 85% or higher.
If the fixing property is not good (◎), if the fixing property is not good (×).
And so.

These results are shown in the table.

Examples 5 to 7 1.3.5-1 An experiment similar to Example 1 was conducted except that 22-bis(4-anatophenyl)propane was used in place of phosphoanatobenzene.

The results are also shown in the table.

]7 [Effects] According to the present invention, it is possible to produce a toner that satisfies offset resistance and fixing properties at the same time, and the toner expands even at the fixing temperature, making it a highly practical product.

Claims (1)

[Scope of Claims] 1. (a) a carboxyl group-containing acrylic resin, (b) a polyfunctional cyanate ester containing two or more cyanato groups in the molecule or the cyanate ester prepolymer, and (c) In a toner for developing an electrostatic image formed by blending a curing catalyst for the resin, two types of resins having different acid values are used as (a), and the acid value of the resin [I] with the lower acid value is The ratio of the acid value of the resin [II] with the higher acid value to the resin [II] is 1.
5 or more, and [II]/([I] + [II]) is 0
．． A toner for electrostatic images, characterized in that it is used in a ratio of 3 to 0.9 (based on weight). 2. The composition consisting of (a), (b), and (c) is heated to a temperature of 10
The electrostatic image toner according to claim 1, which is produced by mixing at 0 to 200°C. 3. The electrostatic image toner according to claim 1, wherein the curing catalyst (b) in (a) is an organometallic compound.