JPH0341470A - Toner for electrostatic image - Google Patents

Abstract

PURPOSE:To form the toner which simultaneously satisfies offset resistance and fixability by specifying the ratio of acid value of a resin having a low acid value I and a resin having a high acid value II to a specific value or above and specifying II/[I+II] to the value of specific range. CONSTITUTION:The ratio of the acid value II of the resin having the higher acid value to the acid value I of the resin having the lower acid value of the resins of the toner consisting of the satd. polyester resins used for developing images as a binder resin component is specified to >=1.5. The compsn. formed by mixing and using these resins at 100 to 200 deg.C at the ratio at which the II/[I+II] attains 0.3 to 0.9 by weight and compounding of a multifunctional cyanate contg. >=2 cyanate in the molecule or cyanate pre polymer and a hardening calalyst of glycidyl group-contg. acrylic resin therewith is used. The toner which simultaneously satisfies the offset resistance and fixability is produced in this way.

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 toner is usually prepared by melt-mixing components consisting mainly of a polymer as a binder component, a coloring agent such as carbon black, and a charge control agent.

Conventionally, styrene-based resins have been the mainstream binder component, but recently, attention has been paid to saturated polyester resins that have large negative chargeability and excellent low-temperature fixing properties, making them suitable for high-speed copying, and much research has been conducted on them. ing.

2 [Problem to be Solved by the Invention 1] When the present invention and others repeatedly investigated l-ners using polyester resin, it was found that an offset phenomenon occurred, that is,
Some of the toner components may be transferred to the commonly used heat roller for fixing, staining the surface of the transfer paper that is subsequently supplied, or may be further transferred to the pressure roller that is pressed by the heat roller, staining the back side of the transfer paper. It was discovered that there is a problem of

Originally, fixing properties and off-sera I/prevention properties are contradictory physical properties, but preventing the offset phenomenon while maintaining low-temperature fixing properties is a must for practical use of polyester resin toners. , this is an issue that must be addressed.

For this reason, in toners using polyester resin, it is recommended to use partially cross-linked macromolecules using trifunctional or two-functional components such as trimeryl and acid as monomers for the raw polyester resin. However, when a trifunctional or higher functional component such as trimellitic acid is used as a monomer, there is no effective method other than lowering the temperature to stop the polymerization reaction and achieve the desired molecular weight and degree of crosslinking. These disadvantages made it difficult to popularize L-ners using polyester resins, despite their excellent properties.

As a countermeasure against this, the present applicant has previously developed (2L) a saturated polyester resin, (b) a polyfunctional cyanate ester containing two or more cyanato groups in the molecule or a prepolymer of the cyanate ester, and (c) the cyanate ester prepolymer. We proposed a toner composition containing a resin curing catalyst.

However, the present inventors continued to study the properties of the toner composition, and found that the fixing temperature of the toner composition was
It was recognized that a more practical product could be obtained by increasing l.

[Means for Solving the Problems] As a result of intensive studies to solve the problems, the present inventors have found that the desired electrostatic image can be obtained by using specific amounts of two types of saturated polyester resins with acid value. The present invention was completed based on the discovery that it is possible to obtain a functional I.na.

That is, the present invention provides a toner containing a saturated polyester resin as a binder resin component used for developing an electrostatic image, in which the saturated polyester resin has an acid value that is higher than the acid value of the resin [1], which has a lower acid value. Higher resin [II
) (hereinafter simply referred to as the acid value ratio) is 5 or more, and (b) a polyfunctional cyanic acid containing two or more cyanato groups in the molecule. This is a toner for electrostatic images characterized by using a polyester resin composition containing an ester prepolymer and the curing catalysts (c) and (a).

The configuration of the present invention will be explained below.

The saturated polyester resin of the present invention is obtained by condensing arbitrary acid components and polyhydric alcohol components. As an acid component,
Terephthalic acid, isophthalic acid, orthophthalic acid, malonic acid, dimethylmalonic acid, succinic acid, geltaric acid, adipic acid, l-limethylanopic acid, pimelic acid, 2.2-
Dimethylcultaric acid, acelaic acid, sebacic acid, 1
3-cyclopentanenocarboxylic acid, I, 2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 25-norbornanedicarboxylic acid, 1,4-naphthalic acid, nfennic acid, 4. 4-okynebenzoic acid, diglycolic acid, thionepropionic acid, 2,5-naphthalene dicarboxylic acid,
Examples include 26-naphthalene dicarboxylic acid, benzoic acid, and rosin derivatives such as rosin, hydrogenated rosin, and semi-uniformed ronone.

These may be acid anhydrides, esters, chlorides, etc., such as dimethyl 1,4-cyclohexanedicarboxylate, trimethyl 2,6-naphthalinocarphonate, dimethyl isophthalate, trimethyl terephthalate, and nophenyl terephthalate. include.

In addition to the above, unsaturated carboxylic acids such as (anhydrous) maleic acid and fumaric acid, and polyhydric carboxylic acids of 3 or more valences,
For example, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylchlorohexene 1 2 3-tricarboxylic anhydride, and I.rimenic acid can also be used.

In addition, examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, 1.3 propantool, 2,4-tumethyl-2-ethylhexane-13-diol, and 2,2-tumethyl-1,3-propantool. (neopentyl glycol), 2-ethyl-
2-isobutyl to 13-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanol, 1,6-hexadiol, 3-methyl-
1,5-pentanesol, 2,24-trimethyl1.
6-hexanol, 1.2-chlorohexanol, 1,3-chlorohexanol, 14-
Nochloheginediol, 2,24.4-teI-ramethyl-1,3-chlorobutanediol, 4.4°-thionephenol, 4.4”(2-kylbornylidene)diphenol, 4,4=dihydro Kimbiphenol, Om
- and p-dihydroquinobenzene, 44'-isopropylidenephenol, 4,4'-isopropylidenehis (
26-dichlorophenol), 2,5-naphthalene diol, and p-ginine diol.

In addition to the above, in small amounts, trihydric or higher polyhydric alcohols, such as pentaerythritol, npentaerythritol, etc.
- Lipentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,36-hexadi-I-liol, etc. can also be used. Compounds containing a hydroxyl group and a calhoquinol group in the molecule, such as a low molecular weight condensate of terephthalic acid and ethylene glycol, can also be used.

In addition to the diacid component and the polyhydric alcohol component, a sulfonic acid group can also be introduced by a commonly known method. Typical condensed acids used in this case are 5-sodiosulfoisophthalic acid and 5-potassium sulfoisophthalic acid, but are not limited to these.

Producing a polyester resin by condensing the acid component and polyhydric alcohol component 1- No special operation is required, and any conventionally known method may be used. (x moles of polyhydric alcohol component are charged into a reactor together with a catalyst, and the temperature is raised to 140 to 260°C to carry out dehydration condensation. The catalysts used in this case include zinc acetate, zinc chloride, stannous lauryl, and butyl. Tin oxide, octyltin oxite, etc. are used, and these are usually charged in an amount of 0.05 to 0.15% based on the dicarboxylic acid.

Although a solvent is not particularly required, an inert solvent such as methyl acetate, Hensen, acetone, kiln, toluene, etc. may be used if desired.

The glass transition temperature of the polynisder resin is 30 to 75°C.
1, preferably 45 to 70°C. In addition, the number average molecular weight is 3,000 to 8,000 and the weight average molecular weight is 10×
I04 or higher, preferably 5. ．． 0XIO'~50xlO
' is preferred.

The acid values of the resins [1] and [II] may be adjusted appropriately during their production, but usually the acid value of [1] is 15 KOHm7
/g, preferably 0,1~I OKO II mL
/ 9, [] is 15 KOI 1 mg/g or more, preferably I 5-40 KOII mg/g
- be sent. The acid value ratio of the two resins should be 1.5 or more, preferably 2 or more. This ratio is 15
In the following, the fixed salinity "D" is narrow and has poor practicality.

It is also necessary to mix at a ratio of 0.3 to 0.9, preferably 0.4 to 0.7, and it is difficult to obtain the effects of the present invention outside this range.

(b) fiR of the present invention blended into the above polyester resin
A polyfunctional cyanate ester containing two or more cyanato groups (-0CN) in its molecule or a cyanate ester prepolymer having the general formula (j) R(OCN)n... ...(
1) (n in the formula is an integer of 2 or more and usually 5 or less, and R
is an aromatic organic group which may contain a heterocycle,
"The di-cyanato group is a compound that is bonded to the aromatic ring of the organic group." Specifically, I,
3 = or 1,4-noanatophenyl, 1,35-1-licyanatohensen, 1.3- 1 4- 16- 1
8-26- or 2,7-dicyanatonaphthalene, 1.
3.6-dolinoanatonaphthalene, 4.4-nocyanatobiphenyl, bis(4-nnoanatophenyl)methane,
Bis(3,5-dimedyl-4-dinoanatophenyl)methane, 2.2bis(4-noanatophenyl)propane, 2
, 2-bis(3,5-ink[l-4-noanatophenyl)furopane, 2,2-his(35-dibromo-4-noanatophenyl)propane, 2,2-his(3,5-nmedyl) 4cyanatophenyl)propane, bis(4-noanatophenyl)ether, bis(4-noanatophenyl)dioether, his(4-noanatophenyl)sulfone, tris(4-7anatophenyl)phosphite,
Tris(4cyanatophenyl)phosphate, a polyfunctional novolacyanate obtained by the reaction of novolak with cyanogenide (USP-4PO22P755, 3,
448,079), polyfunctional polycarbonate cyanates obtained by the reaction of polycarbonate oligomers containing terminal OH groups with cyanogen halides (USP-4
, 026,913; DE-2,611,796),
and styryl-pyridine-cyanate, etc., obtained by reacting poly-hydroxy-styrylpyridine, etc., obtained by reacting hydroxybenzaldehydes with alkyl-substituted pyridines, etc., and cyanogen halide (USP-4).
, 578439). In addition to these, USP-
3,553,244, 3,755,402, 3,740
,348,3,595,900,3,694,410,
4,116946, BP-1,305,967, 1,0
80,933,DE-1,190,184,1,1,9
Cyanic acid esters described in 5,764 and the like can also be used.

In addition, as a prepolymer obtained by polymerizing a divalent polyfunctional cyanate ester in the presence of a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, a phosphate ester such as tributylphosphine, 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 IO parts by weight per 100 parts by weight of the saturated polyester resin.
Preferably I is 0 to 5 parts by weight, especially 1.0 to 2.5 parts by weight. If the blending amount is less than 0.5 parts by weight, it is difficult to obtain the effects of the present invention, while if the blending amount exceeds 10 parts by weight, excessive crosslinking reaction such as an increase in flow initiation temperature occurs, which is not preferable.

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

Examples of such compounds include organic peroxides such as benzoyl peroxide, lauroyl peroxide, caprylic peroxide, acedel peroxide, parachloropenzoyl peroxide, and di-tert-butyl roots perphthalate; Azo compounds such as nitrile 2-methylimidazole, 2-undetulimidazole, 2-hebutadenolimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, ■Hensyl-2-methylimidazole, 1-propyl-2 Methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethylimitazole, 1-cyanoethyl-2-undenolimidazole, I
-Imidazoles exemplified by cyanoethyl-2-phenylimidazole, I-cyanoethyl-2-ethyl-4-methylimidazole, and Iguanaminoedyl-2-methylimidazole, as well as carboxylic acids or their anhydrides to these imidazoles. adducts of NN-
trimethylbenzylamine, N,N-dimethylaniline,
N, N-dimethyltoluidine, N, N-dimethyl-p-anisidine, p-halogeno-N, N-dimethylaniline,
2-N-ethylanilinoethanol, ), n-butylamine, pyrinone, quinoline, N-methylmorpholine,!・Reethanolamine, triethylenediamine, N
Tertiary amines such as N, N', N'-tetramethylbutanediamine and N-methylpiperidine; phenols such as phenol, xylenol, cresol, resolutun, catechol, and phloroglycin; lead naphthenate, lead stearate; Organic metal salts such as zinc naphthenate, zinc octylate, oleic acid group, stannous lauryl, dibdeltin malate, manganese naphthenate, cobalt naphthenate, iron acetylacetonate, and hydroxyl groups such as phenol, bisphenol, etc. Dissolved in containing compounds; Inorganic metal salts such as 5nCI3, ZnCl2, AlC1, etc.; Organotin compounds such as dibdeltin oxide, dioctyltin oxide, other alkyltin and alkyltin oxides; maleic anhydride, phthalic anhydride , lauric anhydride, pyromellitic anhydride, trimellitic anhydride, hexahyphthalic anhydride, hexahydrotrimellitic anhydride, hexahydropyromellitic anhydride, and other acid anhydrides. Among these catalysts, organic metal salts and organic tin compounds such as dibutyltin oxide, dioctyltin oxide, other alkyltins, and alkyltin oxides are particularly suitable.

In addition, the amount of catalyst used is sufficient within the range of catalyst amount in a general sense, for example, 0 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 above-mentioned saturated polyester resin composition, a colorant, and if necessary a charge control agent, etc. are melt-mixed: instead of the saturated polyester resin composition, a saturated polyester resin, (b ) component, (c)
The components are melt-mixed with a coloring agent and, if necessary, a charge control agent, etc.; a so-called masterbatch is prepared by blending a large amount of components (b) and (c) with a saturated polyester resin, and this is mixed with a saturated polyester resin. By melt-mixing a polyester resin, a coloring agent, and if necessary a charge control agent, etc. Further, the blending is preferably carried out using equipment such as an extruder or a pressure kneader with 12 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 carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red,
Examples include quinoline yellow, methylene blue chloride, phthalone anine blue, malachite green oxalate, lamp black, and cause red red.

When producing the toner network of the present invention, if necessary, known auxiliary agents such as binder resins other than the saturated polyester resin which 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 master batch that is previously blended with a saturated polyester resin.

[Function] By using saturated polyester resins having different acid values, the present invention provides a toner with a wide range of fixing temperatures.

[Examples] 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 polyester resin [1]-] Terephthalic acid 05 mol, isophthalic acid 0.5 mol,
After reacting 09 mol of ethylene glycol, 0.2 mol of ethylene glycol, and 0.0003 mol of butyltin oxide at 160° C. to 220° C. in a nitrogen atmosphere for 4 hours, the supply of nitrogen was stopped. Subsequently, the mixture was reacted under reduced pressure of 500 mmHg until the acid value reached 5 KOHmg/'j.

The obtained polyester resin has a melt viscosity of 6 x 103 voids at 100°C (Hinyou Seisakusho Flow Tester CFT).
-500, measurement conditions: orifice diameter 1 mm, orifice length 10 mm, load 30 kli, hereinafter the same), the glass transition temperature was 59°C (measured with PerkinElmer DSC 7 type, 6 the same below).

[N-2 Terephthalic acid 0.7 mol, Isophthalic acid 03 mol,
After reacting 06 mol of ethylene glycol, 0.4 mol of neopentyl glycol, 0.1 mol of triethylene glycol, and 0.0003 mol of cibdeltin oxide at 160°C to 220°C in a nitrogen atmosphere for 4 hours. ,
The nitrogen supply was stopped, and the reaction was carried out under a reduced pressure of 500 mmr (g) until the acid value reached 7 KOII mg/9.

The obtained polyester resin had a melt viscosity of 4XI03 voids at 100°C and a glass transition temperature of 58°C.

[1]-3 In the reaction of [I]-2, the acid value is] 3 KOI1mg
/9, the reaction was stopped and a polyester resin was obtained.

111]-1 Terephthalic acid 0.8 mol, Isophthalic acid 0.2 mol, Ethylene glycol 04 mol, Hisphenol Δ propylene oxide adduct 0.6 mol, Chrycerin
0.03 mol and dibdeltin oxide 0.0003
mol was charged into a four-eye flask with an IC capacity equipped with a packed column, the temperature was lowered to 180 °C under a nitrogen atmosphere, and after additionally charging 0.05 mol of phthalic anhydride, the reaction was further continued at 180 °C for 30 minutes. went.

Stop the nitrogen supply and add 0.001 gibdeltin oxide.
5 mol was added and stirred for 30 minutes under reduced pressure of 500 ml (g) to complete the reaction.

The obtained polyester resin has an acid value of 25 KOHm9/
9. The melt viscosity at 100°C was 2×10′ voids, and the glass transition temperature was 62°C.

[IIl-2 In the same flask as [IIl-], add 0.7 mol of terephthalic acid, 0.3 mol of isophthalic acid, and 0.0 mol of ethylene glycol.
2 moles of disproportionated monoglyceride, 06 moles of hisphenol A ethylene oxide additive, 0.02 moles of trimethylolpropane, and 0.0003 moles of butyltin oxide were charged, and the mixture was stirred at 2400C under a nitrogen atmosphere. The reaction was performed below. When the outflow water stopped, the temperature was lowered to 180°C, and after adding 0.07 mol of phthalic anhydride, the temperature was further heated at 180°C for 30°C.
The reaction continued for minutes.

Then, the nitrogen supply was stopped and dibdeltin dilaurate 0.
0015 mol was added to the mixture and the mixture was stirred for 30 minutes while the thickness was reduced to 5 Q Q mm and 11 g, and the reaction was completed.

The obtained polyester resin has an acid value of 32 KOIImg
/g, the melt viscosity at 100°C was 3XIO'' voids, and the glass transition temperature was 60'C.

[■]-3 [In the reaction of I-K2, the acid value is I 6 KOHm@/
The reaction was stopped when the amount reached g, and a polyester resin was obtained.

Examples 1 to 4, Comparative Examples 1 to 5 01% Nobdel tin dilaurate was added as a curing catalyst to the polyester resin described in 1, 88 parts of this, 9 parts of carbon black #44 (manufactured by Mitsubishi Kasei Corporation), and carbon 1 part of I.Ron 534 (manufactured by Orient Chemical Industry Co., Ltd.), 2 parts of Viscol 550P (manufactured by Sanyo Chemical Industries, Ltd.) and 2,2-
Two parts of bis(4-cyanatophenyl)propane were mixed into powder, and using a twin screw extruder PCM-30 (manufactured by Ikegai Steel Co., Ltd.), the first ring was -60°C, and the second and third printers and cylinder head were heated at 140°C. , shaft rotation speed 100
Kneading and extrusion were carried out at a feed rate of 2009/min.

The obtained extrudate was pulverized to such an extent that it could pass through a 1 mm sieve, then finely pulverized using a jet mill (manufactured by Nippon Nikomadec Co., Ltd.), and classified using an air classifier to obtain a toner.

1 Elephant - Car Otsu - 1 - An electrophotographic copying machine using a mixture of 5 parts of toner and 95 parts of iron powder TEFV 150/250 (manufactured by Nippon Tetsuko Co., Ltd.)
) Transfer the image onto plain paper using C-162 (manufactured by Sanda Kogyo Co., Ltd.), take it out in an unfixed state, and apply Teflon coating 1. The image was fixed by passing it between a heated roll and a rubber-lined hub up roll at a speed of 275 mm/sec.

The temperature of the heat roll was varied from 150 to 240°C, and when there was no toner adhesion to the heat roll, the offset property was evaluated as good (◎), and when it was noticeable, it was evaluated as poor (x), and the normal state of the image was evaluated. Deer skin was coated with mending tape N0810 (manufactured by Kahei 3M Co., Ltd.), and the density retention rate was measured using a Macbeth densitometer (manufactured by Macbeth Co., Ltd.).If the density retention rate was 85% or more and the fixation was sufficiently performed. The fixing property was rated as good (◎), and the fixing property was rated as poor (×).

These results are shown in the table.

Examples 5 to 7 The same experiments as in Example I were conducted except that 1,3,5-1-linoanatobenzene was used in place of 2.2-his(4-cyanatophenyl)propane.

The results are also shown in the table.

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

Claims (1)

[Scope of Claims] 1. (a) a saturated polyester resin, (b) a polyfunctional cyanate ester containing two or more cyanato groups in the molecule or a prepolymer of the cyanate ester, and (c) a polyester of the resin. In a toner for developing an electrostatic image that contains a curing catalyst, two types of resins with different acid values are used as (a), and the acid value is determined relative to the acid value of the resin [I] with the lower acid value. The acid value ratio of the resin [II] with the higher value 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 170°C. 3. The electrostatic image toner according to claim 1, wherein the curing catalyst (c) in (a) is an organometallic compound.