KR20100004335A - Polyester for toner - Google Patents

Abstract

PURPOSE: A polyester for toner is provided to ensure excellent low temperature fixation, offset resistance and storage stability, and to realize clear image. CONSTITUTION: A polyester for toner is obtained by reacting a mixture of a first component, a second component and a third component and has number average molecular weight of 2,000 or more, weight average molecular weight of 8,000 or more, glass transition temperature of 50 °C or more, and softening point of 100-180 °C. The first component comprises 85-100 mole % aromatic dicarboxylic acid(containing acid anhydride) or alkylester thereof, and 15-0 mole % aliphatic dicarboxylic acid(containing acid anhydride) or alkylester thereof.

Description

Polyester resin for toner fixing {Polyester for Toner}

The present invention relates to a polyester resin for toner fixing, and more particularly, to a polyester resin for toner fixing used for electrophotographic, electrostatic rock, electrostatic printing, and the like.

Toner used for electrophotographic, electrostatic recording, electrostatic printing, and the like is attached to a drum by using the electrostatic principle, then transferred onto a recording medium such as paper or OHP film, onto a desired image, and heated and pressed with a heated roller to be fixed to the paper. At this time, when the temperature of the heating roller is low, the fixing resin in the toner transferred to the recording medium does not partially melt, so that it is difficult to fix the clear image.If the temperature of the heating roller continues to rise in a continuous operation, the toner melts excessively and Fusion. Recently, with the introduction of small copiers and printing apparatuses capable of high-speed operation, high-functional toners that are easily fixed at low temperatures such as paper or OHP films, and have less phenomenon (offset) in which unfixed toner is fused to a heating roller are required. It is also important to prevent the toner from agglomerating due to an increase in the internal temperature of the apparatus after the toner is loaded in the apparatus. On the other hand, polyester resins are preferred as toner fixing resins because of excellent low temperature fixability, and studies are being actively conducted to widen the molecular weight distribution as a method of suppressing offset generation without impairing low temperature fixability. Japanese Patent Application Laid-Open No. 63-61018 discloses 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexane in order to form crosslinks in the resin as a way to broaden the molecular weight distribution. Tricarboxylic acids such as tricarboxylic acid and 2,5,7-naphthalene tricarboxylic acid or anhydrides thereof were used. However, although the offset resistance can be improved by using the tricarboxylic acid as described above, the crosslinking degree becomes severe even when the reaction conditions of polyester are synthesized, and the discharge workability becomes poor or when used as a toner fixing resin. These non-uniformly occurring problems arise.

The present invention is to solve the above problems, and an object of the present invention is to provide a polyester resin for fixing toner that is not only excellent in low temperature fixability, offset resistance and storage stability, but also can implement a clear image. will be.

The present invention comprises 85 to 100 mol% of aromatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof, and 15 to 0 mol% of aliphatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof in order to achieve the above object. Obtained by reacting a mixture of at least one second component selected from one component, aromatic diol, alicyclic diol, and aliphatic diol, at least one third component selected from hydroxy acid and hydroxy acid derivatives, and number average Toner fixing with molecular weight of 2,000 or more, weight average molecular weight of 8,000 or more, glass transition temperature of 50 ° C or more, softening temperature of 100 to 180 ° C, and low temperature fixing property, offset resistance and storage stability of the toner when used as a constituent of the toner It is providing the polyester resin for.

The present invention provides a polyester resin for fixing toner that is excellent in improving low temperature fixability and offset resistance when used as a constituent of a toner and does not cause aggregation problems even when stored for a long time.

Hereinafter, the present invention will be described in detail.

The polyester resin for fixing toner of the present invention comprises 85 to 100 mol% of aromatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof, and 15 to 0 mol% of aliphatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof. It is prepared by reacting a mixture of at least one second component selected from the first component, aromatic diol, alicyclic diol and aliphatic diol, at least one third component selected from hydroxy acid and hydroxy acid derivative.

Hereinafter, the polyester resin constituent for toner fixing of the present invention will be described in detail.

As said 1st component, 85-100 mol% of aromatic dicarboxylic acids (including acid anhydride) or its alkyl ester is comprised from 15 to 0 mol% of aliphatic dicarboxylic acid (including acid anhydride) or its alkyl ester. Polyesters are obtained by reacting dicarboxylic acids with dihydric alcohols, and polyesters synthesized using aromatic dicarboxylic acids as acid components have higher softening and glass transition temperatures than polyesters synthesized using aliphatic dicarboxylic acids. Among the components of the toner composition used for electrophotographic, electrostatic lock, and electrostatic radiation, the fixing resin is melted by the heating roller of the apparatus and fixed to the paper or film together with the other composition constituting the toner. Has a great influence on fixability and offset resistance. If the softening temperature or the glass transition temperature is low, the fixing property is improved, but the offset resistance is basically weak, and the characteristics of the toner fixing resin are lost. Therefore, the 1st component which comprises the polyester resin for fixing toners of this invention contains 85 mol% or more of aromatic dicarboxylic acid (including acid anhydride) or its alkyl ester. In this case, as aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, 5-sulfoisophthalic acid monosodium salt, etc. may be used, and the alkyl esters thereof include dimethyl terephthalate, diethyl terephthalate, and dimethyl isophthalate. , Dimethyl phthalate, (5-sulfoisophthalic acid) dimethyl ester monosodium salt and the like can be used. In addition, the first component is an aliphatic dicarboxylic acid, succinic anhydride, glutaric acid, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decandicarboxylic acid, and the like. Acid anhydrides such as acid anhydrides, and aliphatic dicarboxylic acid alkyl esters such as dimethylsuccinate, dimethylglutarate, dimethyl adipate and the like may be further used.

As the second component, at least one compound selected from aromatic diols, alicyclic diols, and aliphatic diols is used. Such compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylglycol , 1,4-cyclohexanedimethanol, 2,2'-bis (4-hydroxyethoxyphenyl) propane, 2,2'-bis (4-hydroxypropoxyphenyl) propane, diethylene glycol, triethylene Glycols, polyethylene glycols, and poly (oxyethyleneoxypropylene) glycols. It is preferable to use the second component in a ratio of 1.1 to 2.0 with respect to the number of moles of the first component. If the molar ratio exceeds 2.0, the production efficiency is lowered.

As the third component, at least one compound selected from hydroxy acids and hydroxy acid derivatives is used. As the hydroxy acid, 4-hydroxybenzoic acid, glycolic acid, L-lactic acid, D-lactic acid, β -hydroxypropionic acid, β -hydroxybutyl acid, γ -hydroxybutyl acid, β -hydroxy valeric acid, δ -hydroxy valeric acid, γ -hydroxyhexanoic acid, δ -hydroxyhexanoic acid, ε -hydroxyhexanoic acid, γ -hydroxyheptanoic acid, γ -hydroxyoctanoic acid, δ -hydric Hydroxyoctanoic acid, γ -hydroxydecanoic acid and δ -hydroxydecanoic acid, 2,2'-bis (hydroxymethyl) propionic acid, 2,2'-bis (hydroxymethyl) butyl acid, 10, 16-dihydroxyhexadecanoic acid, 3,12-dihydroxypalmitic acid, 15,15'-dihydroxypalmitic acid, 3,11-dihydroxymyritic acid, 9,10-dihydrate Oxystearic acid, 2,5,16-trihydroxyhexadecanoic acid, 9,10,16-trihydroxy palmitic acid, 3,4,5-trihydroxycyclohexene-1-carboxylic acid, 1,3, 4,5-tetrahydroxycyclohexane-1-carboxylic acid, 2- De-hydroxy succinic acid, 2,3-dihydroxy there are succinic acid, 2,4-dihydroxy benzo acid, 2,5-dihydroxy benzo acid, 2,6-dihydroxy benzo acid, citric acid and the like. As the hydroxy acid derivative, β -propiolactone, β -butyrolactone, γ -butyrolactone, β -valerolactone, δ -valerolactone, γ -hexanolactone, δ -hexanorlactone, ε- Cyclic monomers such as caprolactone, γ -heptanolactone, γ -octanolactone, δ -octanolactone, γ -decanolactone, δ -decanolactone, glycolides, L-lactide, D-lactide, Cyclic dimers such as D, L-lactide and the like. The third component is preferably used in a ratio of 1 to 30 moles with respect to 100 moles of the first component.

The polyester resin of the present invention preferably has a number average molecular weight of 2,000 or more, more preferably 3,000 or more, and a weight average molecular weight of 8,000 or more, more preferably 8,000 or more, in view of stability of the toner.

It is preferable that the glass transition temperature of the polyester resin of this invention is 50 degreeC or more. When the glass transition temperature is lower than 50 ° C., a toner cartridge may be mounted on the machine and agglomeration of toner particles may occur during use.

It is preferable that the softening temperature of the polyester resin of this invention is 100-180 degreeC. In the case of a toner using a polyester having a softening temperature of less than 100 ° C., the fixing property is excellent, but it is difficult to obtain a clear and clean image because an offset phenomenon in which a part of the toner is fused to the heating roller for fixing occurs during continuous operation. On the other hand, in the case of a toner using a polyester having a softening temperature of more than 180 ° C., the toner fixability is deteriorated due to some unmelted polyester resin during copying or printing.

Hereinafter, the manufacturing process of the polyester resin for toner fixing of this invention is demonstrated in detail.

First, the reactant is obtained by mixing the first component and the second component by esterification and / or transesterification. At this time, a small amount of the metal salt can be added as a reaction catalyst, and the metal salts that can be used include calcium acetate, manganese acetate, magnesium acetate, zinc acetate, monobutyl tin oxide, dibutyl tin oxide, stamina octoate, and dibutyl tin. Chloride, tetraphenyltin, tetrabutyltin, tetrabutyl titanate, tetramethyl titanate, tetraisopropyl titanate and tetra (2-ethylhexyl) titanate. The esterification reaction or transesterification reaction is preferably carried out in an inert gas atmosphere in order to suppress side reactions by oxygen, preferably in the range of 100 to 260 ℃ in consideration of the melting point or boiling point of the components used in the present invention. Do. Subsequently, at least one compound selected from hydroxy acids and hydroxy acid derivatives is added as a third component to the reactants of the first component and the second component, and the reaction is carried out in an inert gas atmosphere and / or a reduced pressure atmosphere. In this case, considering the melting point or boiling point of the reactants is preferably carried out in the range of 100 to 230 ℃, the above-mentioned metal salt, etc. may be added as a catalyst.

When preparing the polyester resin, as a heat stabilizer, phosphoric acid, monomethyl phosphoric acid, trimethyl phosphoric acid, tributyl phosphoric acid, trioctyl phosphoric acid, monophenyl phosphoric acid, triphenyl phosphoric acid and its derivatives, phosphorous acid, triphenyl phosphoric acid, trimethyl phosphoric acid and its derivatives, It is possible to use one or more selected from Iganox 1010, Iganox 1222, Igaforce 168 and phenylphosphonic acid.

The toner according to the present invention contains a fixing resin and a coloring agent mainly containing the polyester resin, and the content of the fixing resin in the toner is preferably 50 to 95% by weight. As the colorant, carbon black, nigrosine dye, lamp black, Sudan black SM, navel yellow, mineral fast yellow, littol red, permanent orange 4R, and the like may be used. In addition, the toner of the present invention may further include conventional additives such as an electrostatic control agent, a magnetic powder, a releasing agent and the like. Static control agents include "TP-415" (Hodoya Chemical), "TP-152" (Hodoya Chemical), "TP-4040" (Hodoya Chemical), "Bontron P-51" (Orient Chemical), "FCA Quaternary ammonium salts such as -201-PS "(Fuji-Kurakasei) and" Copy Charge PSY "(Client), polyamine-based resins such as" AFP-B "(Orient Chemical), FCA-1001-NS" (Fuji-Kurakasei) A polymer having a sulfonic acid group, alkyl salicylic acid and metal complexes thereof, and the like, are used as magnetic powders, ferrite, magnetite, etc. In addition, as a release agent, a wax having a softening temperature of 60 to 110 ° C., more specifically, Synthetic wax such as polyethylene wax, polypropylene wax, polyolefin wax, natural wax such as carnauba wax, montan ester wax, beeswax, rice wax, mixtures thereof, etc. can be used. Or toner fixing resin pole for twin screw extruder or mixer It is prepared by pulverizing a product obtained by adding an ester resin, a colorant, an additive, etc., and kneading at a temperature higher than the softening temperature of the polyester resin at 10 to 40 ° C. The average particle size of the toner thus prepared is usually 5 to 20 μm. More preferably, it is 5-15 micrometers.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. The following examples and comparative examples illustrate the invention in more detail, but do not limit the scope of the invention. The performance evaluation method used by the following Example and the comparative example is as follows.

(1) Tg (Glass Transition Temperature, ° C): Using a differential scanning calorimeter (DSC), the sample is melted and quenched and then measured at a temperature rising rate of 10 ° C / min. The median value of each tangent line with the base line of an endothermic curve is set to Tg.

(2) Softening temperature (℃): A fluid tester (CFT-500D, manufactured by Shimadzu Laboratories) was equipped with a nozzle having a diameter of 1 mm and a length of 10 mm, and a sample of 1.5 g was added and a 10 kgf load was applied while raising the temperature to 6 DEG C / min. The temperature at which half flows is made into softening temperature (degreeC).

(3) Minimum fixing temperature and offset temperature: After coating the manufactured toner on a white paper, passing through the heating roller at a speed of 100 mm / sec, the minimum temperature of the heating roller to maintain a fixing efficiency of 90% or more, the minimum fixing temperature, The maximum temperature is defined as the offset temperature. The minimum fixing temperature and offset temperature are measured by adjusting the heating roller temperature from 50 to 220 ℃.

(4) Storage stability: 100 g of the toner prepared in a glass bottle is sealed and passed after 50 hours at 50 ° C., the toner is passed through a 40 mesh filter network to determine the percentage of the net jam as storage stability. Excellent stability

Example 1

Preparation of polyester resin (A)

166 parts by weight of terephthalic acid, 316 parts by weight of 2,2'-bis (4-hydroxyethoxyphenyl) propane, 19 parts by weight of 1,2-propanediol and 0.5 weight of dibutyl tin oxide in a reactor equipped with a stirrer and an outlet condenser. Part was added, and the esterification reaction was performed for 5 hours while gradually raising the temperature of the reactor to 250 ° C. under a nitrogen atmosphere. At this time, the theoretical amount of water, the generated side reaction product, was discharged out of the system through a condenser. Subsequently, the obtained reactant was added to a reaction tube kept at 170 ° C. in a nitrogen atmosphere, and 30 parts by weight of 9,10,16-trihydroxy palmitic acid and 72 parts by weight of L-lactide were further added at 195 ° C. for 1 hour. Reaction was carried out again for 90 minutes under the condition of 15 mmHg to obtain a polyester resin (A). The polyester resin (A) thus prepared had a softening temperature of 135 ° C, a glass transition temperature of 54 ° C, a number average molecular weight of 2,800, and a weight average molecular weight of 17,700.

Preparation of Toner (A)

85 parts by weight of polyester resin (A), 7 parts by weight of carbon black, 7 parts by weight of polypropylene wax, and 1 part by weight of electrostatic control agent are mixed in a Henschel mixer and mixed uniformly. Kneading was extruded.

Then, the resultant was pulverized using a jet mill grinder to prepare toner particles having an average particle diameter of 7 mu m. In addition, the minimum fixing temperature, the offset temperature and the storage stability of the manufactured toner were evaluated and shown in Table 1.

Example 2

Preparation of polyester resin (B)

166 parts by weight of terephthalic acid, 316 parts by weight of 2,2'-bis (4-hydroxyethoxyphenyl) propane, 22 parts by weight of neopentyl glycol and 0.5 parts by weight of dibutyl tin oxide were added to a reactor equipped with a stirrer and an outflow condenser. , The esterification reaction was carried out for 5 hours while gradually raising the temperature of the reactor to 250 ℃ under a nitrogen atmosphere. At this time, the theoretical amount of water, the generated side reaction product, was discharged out of the system through a condenser. Subsequently, the obtained reactant was added to a reaction tube kept at 170 ° C. in a nitrogen atmosphere, and 30 parts by weight of 9,10,16-trihydroxy palmitic acid and 72 parts by weight of L-lactide were further added at 195 ° C. for 1 hour. The mixture was further reacted again for 90 minutes under the condition of 15 mmHg to obtain a polyester resin (B). The polyester resin (B) thus prepared had a softening temperature of 132 ° C, a glass transition temperature of 52 ° C, a number average molecular weight of 2,900, and a weight average molecular weight of 22,300.

Preparation of Toner B

Except for 85 parts by weight of polyester resin (A) instead of 85 parts by weight of polyester resin (B) was carried out in the same manner as in Example 1, to evaluate the minimum fixing temperature, offset temperature and storage stability of the prepared toner Table 1 shows.

Comparative Example 1

Preparation of Polyester Resin (C)

166 parts by weight of terephthalic acid, 316 parts by weight of 2,2'-bis (4-hydroxyethoxyphenyl) propane, 15 parts by weight of 1,2-propanediol and 0.5 weight of dibutyl tin oxide in a reactor equipped with a stirrer and an outflow condenser. Part was added, and the esterification reaction was performed for 5 hours while gradually raising the temperature of the reactor to 250 ° C. under a nitrogen atmosphere. At this time, the theoretical amount of water, the generated side reaction product, was discharged out of the system through a condenser. Subsequently, the obtained reactant was added to a reaction tube kept at 170 ° C. in a nitrogen atmosphere, and 30 parts by weight of 9,10,16-trihydroxy palmitic acid and 72 parts by weight of L-lactide were further added at 195 ° C. for 1 hour. The reaction was further carried out again for 30 minutes under the condition of 15 mmHg to obtain a polyester resin (C). The polyester resin (C) thus prepared had a softening temperature of 135 ° C, a glass transition temperature of 53 ° C, a number average molecular weight of 2,800, and a weight average molecular weight of 5,900.

Preparation of Toner C

Except for 85 parts by weight of polyester resin (A) 85 parts by weight of polyester resin (C) was carried out in the same manner as in Example 1, and evaluated the minimum fixing temperature, offset temperature and storage stability of the prepared toner Table 1 shows.

Comparative Example 2

Preparation of Polyester Resin (D)

108 parts by weight of terephthalic acid, 41 parts by weight of succinic acid, 316 parts by weight of 2,2'-bis (4-hydroxyethoxyphenyl) propane, 1,2-propanediol 15 and dibutyltin in a reactor equipped with a stirrer and an outlet condenser 0.5 parts by weight of oxide was added, and the esterification reaction was performed for 5 hours while gradually raising the temperature of the reactor to 250 ° C. under a nitrogen atmosphere. At this time, the theoretical amount of water, the generated side reaction product, was discharged out of the system through a condenser. Subsequently, the obtained reactant was added to a reaction tube maintained at 170 ° C., and 30 parts by weight of 9,10,16-trihydroxy palmitic acid and 72 parts by weight of L-lactide were added thereto for 1 hour at 195 ° C. The reaction was carried out again for 90 minutes under conditions of 15 mmHg to obtain a polyester resin (D). The polyester resin (D) produced had a softening temperature of 123 ° C., a glass transition temperature of 46 ° C., a number average molecular weight of 2,800, and a weight average molecular weight. 20,000.

Preparation of Toner D

Except for 85 parts by weight of polyester resin (A) 85 parts by weight of polyester resin (D) was carried out in the same manner as in Example 1, to evaluate the minimum fixing temperature, offset temperature and storage stability of the prepared toner Table 1 shows.

Table 1

Claims (9)

Aromatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof 85 to 100 mol%, aliphatic dicarboxylic acid (including acid anhydride) or its first component consisting of 15 to 0 mol%, aromatic diol, alicyclic diol And a mixture of at least one second component selected from aliphatic diols, at least one third component selected from hydroxy acids and hydroxy acid derivatives, and a number average molecular weight of 2,000 or more and a weight average molecular weight of 8,000 or more. Polyester resin for toner fixing having a glass transition temperature of 50 ° C. or higher and a softening temperature of 100 ° C. to 180 ° C. The polyester resin for toner fixing according to claim 1, wherein the third component is used in a ratio of 1 to 30 mol relative to 100 mol of the first component. The monocomponent according to claim 1 or 2, wherein the first component is terephthalic acid, isophthalic acid, (5-sulfoisophthalic acid) monosodium salt, dimethyl terephthalate, dimethyl isophthalate, (5-sulfoisophthalic acid) dimethyl ester mono At least one selected from sodium salts is 85 to 100 mol%, at least one selected from succinic acid, glutaric acid and adipic acid is 15 to 0 mol%, polyester resin for toner fixing The second component according to any one of claims 1 to 3 is ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5 -Pentanediol, 1,6-hexanediol, neopentylglycol, 1,4-cyclohexanedimethanol, 2,2'-bis (4-hydroxyethoxyphenyl) propane, 2,2'-bis (4- Polyester resin for toner fixing, which is at least one selected from hydroxypropoxyphenyl) propane, diethylene glycol, triethylene glycol, polyethylene glycol, and poly (oxyethylene oxybutylene) glycol. The third component according to any one of claims 1 to 4 is glycolic acid, L-lactic acid, D-lactic acid, 10,16-dihydroxyhexadecanoic acid, 2,3-dihydroxystearic acid, 9 , 10-dihydroxystearic acid, 9,10,16-trihydroxypalmitic acid, 3,4,5-trihydroxycyclohexene-1-carboxylic acid, 1,3,4,5-tetrahydroxycyclohexane Polyester resin for fixing toner, characterized in that at least one selected from -1-carboxylic acid. The polyester component for toner fixing according to any one of claims 1 to 4, wherein the third component is citric acid. The toner according to any one of claims 1 to 4, wherein the third component is at least one selected from glycolide, L-lactide, D-lactide, DL-lactide, and epsilon -caprolactone. Fixing polyester resin First component comprising aromatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof in an amount of 85 to 100 mol%, aliphatic dicarboxylic acid (including acid anhydride) or alkyl ester thereof in an amount of 15 to 0 mol%, aromatic diol and alicyclic diol And esterifying and / or transesterifying one or more second components selected from aliphatic diols; The reaction product obtained therefrom and at least one third component selected from hydroxy acid and hydroxy acid derivatives are reacted in an inert gas atmosphere or a reduced pressure atmosphere in the presence of a metal salt, and has a number average molecular weight of 2,000 or more and a weight average molecular weight of 8,000. The method for producing a polyester resin for toner fixing having a glass transition temperature of 50 ° C or more and a softening temperature of 100 ° C to 180 ° C. A toner containing the polyester resin for fixing toner according to any one of claims 1 to 8.