JP2007292820A - Polyester for toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester for toners which excels in low-temperature fixability, offset resistance, storage stability and grindability and suppresses emission of a foul odor, and a toner containing the polyester. <P>SOLUTION: The polyester for toners is obtained by condensation polymerization of an alcohol component containing an aliphatic polyhydric alcohol and a carboxylic acid component containing fumaric acid modified rosin. The toner containing the polyester for toners is also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polyester for toner used as a binder resin for toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and a toner containing the polyester.

Along with the development of electrophotographic technology, a toner having excellent low-temperature fixability and storage stability (blocking resistance) is required, and a toner containing a linear polyester resin that defines physical properties such as molecular weight (see Patent Document 1). In addition, a toner containing a non-linear cross-linked polyester resin using a rosin as an acid component in polyester (see Patent Document 2), and a toner having improved fixability using a rosin modified with maleic acid (Patent Document) 3)) has been reported. Also, a toner containing a low molecular weight polyester and a high molecular weight polyester using an aliphatic alcohol as a monomer as an alcohol component has been reported (see Patent Document 4).
JP 2004-245854 A JP-A-4-70765 JP-A-4-307557 JP-A-2-127657

  However, due to the further increase in speed and energy saving of recent machines, it has been found that conventional binder resins for toner are insufficient for market demand. That is, it is very difficult to maintain sufficient fixing strength due to shortening of the fixing time in the fixing process and lowering of the heating temperature in the fixing machine.

  On the other hand, if the softening point of the resin is lowered to improve the low-temperature fixability, offset occurs, and the glass transition point is inevitably lowered, resulting in poor storage stability such as toner aggregation. It becomes.

  The rosins used in Patent Document 2 and Patent Document 3 are effective in improving the low-temperature fixability, but further improvement is required for storage stability, and odor is generated depending on the type of rosin. It also has the disadvantage of being easy to do.

  Furthermore, although polyesters using aliphatic alcohols are excellent in fixability, they have the disadvantage that the resin is fused during pulverization because the pulverizability is too good, and the productivity is rather inferior.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester for toner that is excellent in low-temperature fixability, offset resistance, storage stability and pulverization, and that reduces odor generation, and a toner containing the polyester.

  The present invention relates to a polyester for toner obtained by condensation polymerization of an alcohol component containing an aliphatic polyhydric alcohol and a carboxylic acid component containing a fumaric acid-modified rosin, and a toner containing the toner polyester. .

  The toner containing the polyester for toner of the present invention is excellent in low-temperature fixability, offset resistance, storability and pulverization properties, and has an excellent effect of reducing odor generation.

  The present invention relates to a polyester for toner obtained by condensation polymerization of an alcohol component and a carboxylic acid component, wherein the alcohol component contains an aliphatic polyhydric alcohol and the carboxylic acid component contains a fumaric acid-modified rosin. Has major features. The fumaric acid-modified rosin enables fixing at an extremely low temperature and improves storage stability. A maleic modified rosin modified with maleic acid, which is a modified rosin conventionally used, having a low degree of modification has three functional groups and functions as a crosslinking agent. For this reason, the polyester obtained by using a carboxylic acid component containing a large amount of maleic-modified rosin in order to enhance the fixing property contains a large amount of a low molecular weight component and a high molecular weight component. It is difficult to achieve both storage stability. On the contrary, when the amount of the maleic rosin is reduced, the low-temperature fixability of the resulting polyester is lowered. However, the fumaric acid-modified rosin used in the present invention has an extremely high glass transition point (Tg) even when the rosin has three functional groups. It is presumed that a surprising effect is achieved that the conflicting characteristics of offset resistance and storage stability are compatible. Furthermore, since the aliphatic polyhydric alcohol component used in the present invention is molecularly compact and highly reactive, even if it uses a fumaric acid-modified rosin that is bulky and low in reactivity, it has a number average molecular weight. A large polyester is obtained. That is, by polycondensing an alcohol component containing an aliphatic polyhydric alcohol and a carboxylic acid component containing a fumaric acid-modified rosin, a low molecular weight component is reduced and a polyester having a large number average molecular weight is obtained. It is presumed that a surprising effect is achieved that it is possible to achieve both contradictory properties such as low-temperature fixability, offset resistance and storage stability without impairing grindability.

  The fumaric acid-modified rosin in the present invention is a rosin modified with fumaric acid, and is mainly composed of abietic acid, neoabietic acid, parastrinic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, dehydroabietic acid and repopimaric acid. And rosin to be obtained by addition reaction of fumaric acid, specifically, lepopimaric acid having a conjugated double bond among the main components of rosin, abietic acid, neoabietic acid and parastrinic acid, It can be obtained through a Diels-Alder reaction under heating with fumaric acid.

  The degree of modification of rosin with fumaric acid (fumaric acid modification degree) is preferably 5 to 105, more preferably 20 to 105, still more preferably 40 to 105, from the viewpoint of increasing the molecular weight of the polyester and increasing the glass transition point. ~ 105 is more preferred.

  The degree of fumaric acid modification is expressed by the formula (A):

(Wherein X ₁ is the SP value of fumaric acid-modified rosin for calculating the degree of modification, X ₂ is the SP value of fumaric acid-modified rosin obtained by reacting 1 mol of fumaric acid and 0.7 mol of rosin, and Y is the rosin (Indicates SP value)
Is calculated by Here, the SP value means a softening point measured by a ring and ball automatic softening point tester described later. The molecule of formula (A) means the degree of increase in SP of rosin modified with fumaric acid, and the higher the value of formula (A), the higher the degree of modification.

  The glass transition point of the fumaric acid-modified rosin is preferably 40 to 90 ° C, more preferably 45 to 85 ° C, and still more preferably 50 to 80 ° C, from the viewpoint of enhancing the storage stability of the resulting polyester.

  The production method of the fumaric acid-modified rosin is not particularly limited. For example, the rosin and fumaric acid are mixed and heated to about 180 to 260 ° C., thereby having a conjugated double bond contained in the rosin by the Diels-Alder reaction. A fumaric acid-modified rosin can be obtained by adding fumaric acid to the acid.

  Further, from the viewpoint of efficiently reacting rosin and fumaric acid, it is preferable to react rosin and fumaric acid in the presence of phenols. As the phenols, a divalent phenol and a phenolic compound having a substituent at least in the ortho position with respect to the hydroxyl group (hereinafter referred to as hindered phenol) are preferable, and hindered phenol is more preferable.

  The divalent phenol means a compound in which two OH groups are bonded to a benzene ring and has no other substituent, and hydroquinone is preferred.

  Hindered phenols include mono-t-butyl-p-cresol, mono-t-butyl-m-cresol, t-butylcatechol, 2,5-di-t-butylhydroquinone, 2,5-di-t- Amylhydroquinone, propyl galade, 4,4'-methylenebis (2,6-t-butylphenol), 4,4'-isopropylidenebis (2,6-di-t-butylphenol), 4,4'-butylidenebis ( 3-methyl-6-t-butylphenol), butylhydroxyanisole, 2,6-di-t-butyl-p-cresol, 2,6-di-t-butylphenol, 2,6-di-t-butyl-4 -Ethylphenol, 2,4,6-tri-t-butylphenol, octadecyl-3- (4-hydroxy-3 ', 5'-di-t-butylphenyl) propionate, distearyl (4-hydroxy-3-methyl -5-t-butyl) benzyl malonate, 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 2,6- Fer-4-octadecanoxyphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 2,2 '-Isobutylidenebis (4,6-dimethylphenol), 2,2'-dihydroxy-3,3'-di- (α-methylcyclohexyl) -5,5'-dimethyldiphenylmethane, 2,2'- Methylenebis (4-methyl-6-cyclohexylphenol), tris [β- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 1,3,5-tris (2,6 -Dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, tris (3,5-di-t-butyl-4-hydroxyphenol) isocyanurate, 1,1,3'-tris (2-methyl- 4-Hydroxy-5-t-butylphenyl) butane, 2,6-bis (2'-hydroxy-3'-t-butyl-5'-methylbenzyl) -4-methylphenol, N, N -Hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamate), hexamethylene glycolbis [β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], tri Ethylene glycol bis [β- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane Of these, t-butylcatechol is preferred.

  The amount of the phenolic compound used is preferably 0.001 to 0.5 parts by weight, more preferably 0.003 to 0.1 parts by weight, and still more preferably 0.005 to 0.1 parts by weight with respect to 100 parts by weight of the raw material monomer of the fumaric acid-modified rosin.

  The fumaric acid-modified rosin may be used as it is, or may be used after purification through an operation such as distillation.

  The rosin used in the fumaric acid-modified rosin in the present invention is natural rosin obtained from pine, isomerized rosin, dimerized rosin, polymerized rosin, disproportionated rosin, and the like, such as abietic acid, neoabietic acid, parastolic acid, As long as it is a rosin mainly composed of pimaric acid, isopimaric acid, sandaracopimaric acid, dehydroabietic acid and lepopimaric acid, a known rosin can be used without any particular limitation. From the viewpoint of color, natural rosin pulp is produced. Natural rosins such as tall rosin obtained from tall oil obtained as a by-product in the process, gum rosin obtained from raw pine sprout, wood rosin obtained from pine stumps are preferred, and tall rosin is more preferred from the viewpoint of low-temperature fixability.

  Since the fumaric acid-modified rosin in the present invention is obtained through a Diels-Alder reaction under heating, impurities that cause odor are reduced and the odor is low. From the viewpoint of improvement, fumaric acid-modified rosin is preferably obtained by modifying purified rosin with fumaric acid, and more preferably obtained by modifying purified tall rosin with fumaric acid.

  The purified rosin in the present invention is a rosin whose impurities are reduced by the purification process. By purifying rosin, impurities contained in rosin are removed. The main impurities are 2-methylpropane, acetaldehyde, 3-methyl-2-butanone, 2-methylpropanoic acid, butanoic acid, pentanoic acid, n-hexanal, octane, hexanoic acid, benzaldehyde, 2-pentylfuran, 2 , 6-dimethylcyclohexanone, 1-methyl-2- (1-methylethyl) benzene, 3,5-dimethyl-2-cyclohexene, 4- (1-methylethyl) benzaldehyde and the like. In the present invention, among these, the peak intensity of three types of impurities, hexanoic acid, pentanoic acid, and benzaldehyde, detected as a volatile component by the headspace GC-MS method, can be used as an indicator of purified rosin. The reason why the volatile component, not the absolute amount of impurities, is used as an indicator is that the use of the purified rosin in the present invention makes the odor one of the problems of improvement over the conventional polyester using the rosin.

That is, the purified rosin in the present invention has a peak intensity of hexanoic acid of 0.8 × 10 ⁷ or less and a peak intensity of pentanoic acid of 0.4 × 10 ⁷ or less under the measurement conditions of the headspace GC-MS method described later. Rosin having a peak intensity of benzaldehyde of 0.4 × 10 ⁷ or less. Furthermore, from the viewpoint of storage stability and odor, the peak intensity of hexanoic acid is preferably 0.6 × 10 ⁷ or less, and more preferably 0.5 × 10 ⁷ or less. The peak intensity of pentanoic acid is preferably 0.3 × 10 ⁷ or less, and more preferably 0.2 × 10 ⁷ or less. The peak intensity of benzaldehyde is preferably 0.3 × 10 ⁷ or less, and more preferably 0.2 × 10 ⁷ or less.

Furthermore, from the viewpoint of storage stability and odor, it is preferable that n-hexanal and 2-pentylfuran are reduced in addition to the above three substances. The peak intensity of n-hexanal is preferably 1.7 × 10 ⁷ or less, more preferably 1.6 × 10 ⁷ or less, and further preferably 1.5 × 10 ⁷ or less. The peak intensity of 2-pentylfuran is preferably 1.0 × 10 ⁷ or less, more preferably 0.9 × 10 ⁷ or less, and further preferably 0.8 × 10 ⁷ or less.

  As a purification method of rosin, known methods can be used, and methods such as distillation, recrystallization, extraction and the like can be mentioned, and purification by distillation is preferable. As the distillation method, for example, the method described in JP-A-7-286139 can be used, and examples thereof include vacuum distillation, molecular distillation, steam distillation, etc., but purification by vacuum distillation is preferable. For example, distillation is usually performed at a still temperature of 200 to 300 ° C. at a pressure of 6.67 kPa or less, and methods such as ordinary simple distillation, thin film distillation, rectification, etc. are applied. On the other hand, 2 to 10% by weight of a high molecular weight substance is removed as a pitch component, and at the same time, 2 to 10% by weight of an initial fraction is simultaneously removed.

  The softening point of the rosin before modification is preferably 50 to 100 ° C, preferably 60 to 90 ° C, and more preferably 65 to 85 ° C. The softening point of rosin in the present invention means a softening point measured when the rosin is once melted by the method described later and naturally cooled for 1 hour in an environment of a temperature of 25 ° C. and a relative humidity of 50%. .

  The glass transition point of rosin before modification is preferably 10 to 50 ° C., more preferably 15 to 50 ° C. in consideration of the glass transition point of rosin after modification with fumaric acid.

  Furthermore, the acid value of rosin before modification is preferably 100 to 200 mgKOH / g, more preferably 130 to 180 mgKOH / g, and further preferably 150 to 170 mgKOH / g.

  The content of the fumaric acid-modified rosin is preferably 5% by weight or more, more preferably 8% by weight or more, and further preferably 10% by weight or more from the viewpoint of low-temperature fixability in the carboxylic acid component. Further, from the viewpoint of storage stability, it is preferably 85% by weight or less, more preferably 70% by weight or less, further preferably 60% by weight or less, and further preferably 50% by weight or less. From these viewpoints, the content of the fumaric acid-modified rosin is preferably 5 to 85% by weight, more preferably 5 to 70% by weight, further preferably 8 to 60% by weight, and 10 to 50% by weight in the carboxylic acid component. Is more preferable.

  Examples of carboxylic acid compounds other than fumaric acid-modified rosin contained in the carboxylic acid component include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, Aliphatic dicarboxylic acids such as azelaic acid, n-dodecyl succinic acid and n-dodecenyl succinic acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; trimellitic acid, Examples thereof include trivalent or higher polyvalent carboxylic acids such as pyrrolemetic acid; anhydrides of these acids, alkyl (having 1 to 3 carbon atoms) esters, and the like. Such acids, anhydrides of these acids, and alkyl esters of these acids are collectively referred to herein as carboxylic acid compounds.

  The alcohol component contains an aliphatic polyhydric alcohol. The aliphatic polyhydric alcohol is preferably a divalent to hexavalent aliphatic polyhydric alcohol, more preferably a divalent to trivalent aliphatic polyhydric alcohol, from the viewpoint of reactivity with a carboxylic acid containing a modified rosin. The aliphatic polyhydric alcohol preferably contains an aliphatic polyhydric alcohol having 2 to 6 carbon atoms having a more compact molecular structure and high reactivity. Examples of the aliphatic polyhydric alcohol having 2 to 6 carbon atoms include ethylene glycol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2 1,3-butanediol, pentaerythritol, trimethylolpropane, sorbitol, glycerin and the like, among which 1,2-propanediol, 1,3-propanediol and glycerin are preferable. The content of the aliphatic polyhydric alcohol having 2 to 6 carbon atoms is preferably 60 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and substantially 100 in the aliphatic polyhydric alcohol. More preferred is mol%.

  As alcohols other than aliphatic polyhydric alcohols contained in the alcohol component, polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene-2,2-bis (4-hydroxyphenyl) Bisphenol A alkylene oxide adducts such as propane and other bisphenol A alkylene (2 to 3 carbon) oxide (average number of added moles 1 to 16) adducts, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and These alkylene (carbon number 2-4) oxide (average addition mole number 1-16) adducts etc. are mentioned.

  From the viewpoint of reactivity with the fumaric acid-modified rosin, the content of the aliphatic polyhydric alcohol is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 85 mol% or more, substantially, 100 mol% is more preferable.

  In the polyester of the present invention, from the viewpoint of improving offset resistance, in the range not impairing the storage stability, a trivalent or higher raw material monomer other than fumaric acid-modified rosin, that is, a trihydric or higher polyhydric alcohol and / or a trivalent or higher. The polyvalent carboxylic acid compound is preferably contained in the alcohol component and / or carboxylic acid component. The content of the trivalent or higher polyvalent carboxylic acid compound is preferably 0.001 to 40 mol, more preferably 0.1 to 25 mol per 100 mol of the alcohol component, and the content of the trivalent or higher polyhydric alcohol is alcohol. 0.001-40 mol% is preferable in a component, and 0.1-25 mol% is more preferable.

  In the trivalent or higher raw material monomer, as the trivalent or higher polyvalent carboxylic acid compound, trimellitic acid and its derivatives are preferable, and as the trivalent or higher polyhydric alcohol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, Or, their alkylene (2 to 4 carbon atoms) oxide (average addition mole number 1 to 16) adducts, etc. are mentioned. Glycerin, trimellitic acid and derivatives thereof are preferable because they are effective for improving the resistance.

  The condensation polymerization of the alcohol component and the carboxylic acid component is preferably performed in the presence of an esterification catalyst. Preferable examples of the esterification catalyst in the present invention include a titanium compound and a tin (II) compound having no Sn—C bond, and these are used alone or in combination.

  As a titanium compound, the titanium compound which has a Ti-O bond is preferable, and the compound which has a C1-28 total carbon number alkoxy group, an alkenyloxy group, or an acyloxy group is more preferable.

Specific examples of titanium compounds include titanium diisopropylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₃ H ₇ O) ₂ ], titanium diisopropylate bisdiethanolamate [Ti (C ₄ H ₁₀ O ₂ N) ₂ (C ₃ H ₇ O) ₂ ], titanium dipentylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₅ H ₁₁ O) ₂ ], titanium diety rate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (C 2 H 5 O) 2 ], titanium dihydroxy octylate bis triethanolaminate _{[Ti (C 6 H 14 O 3} N) 2 (OHC 8 H ₁₆ O) ₂ ], titanium distearate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₁₈ H ₃₇ O) ₂ ], titanium triisopropylate triethanolamate [Ti (C _{6 H 14 O 3 N) 1 (} C 3 ₇ O) _3], titanium monopropylate tris (triethanolaminate) _{[Ti (C 6 H 14 O 3} N) 3 (C 3 H 7 O) 1 ], and the like, titanium diisopropylate Among these Preferred are rate bistriethanolamate, titanium diisopropylate bisdiethanolamate, and titanium dipentylate bistriethanolamate, which are also commercially available, for example, from Matsumoto Trading Co., Ltd.

Specific examples of other preferable titanium compounds include tetra-n-butyl titanate [Ti (C ₄ H ₉ O) ₄ ], tetrapropyl titanate [Ti (C ₃ H ₇ O) ₄ ], tetrastearyl titanate [Ti ( C ₁₈ H ₃₇ O) ₄ ], tetramyristyl titanate [Ti (C ₁₄ H ₂₉ O) ₄ ], tetraoctyl titanate [Ti (C ₈ H ₁₇ O) ₄ ], dioctyl dihydroxyoctyl titanate [Ti (C ₈ H ₁₇ O) ₂ (OHC ₈ H ₁₆ O) ₂ ], dimyristyl dioctyl titanate [Ti (C ₁₄ H ₂₉ O) ₂ (C ₈ H ₁₇ O) ₂ ] and the like. Among these, tetrastearyl titanate, tetra Preferred are myristyl titanate, tetraoctyl titanate and dioctyl dihydroxy octyl titanate, which react, for example, a titanium halide with the corresponding alcohol. Can also be obtained by a, it is also available as marketed products of Nisso, or the like.

  The amount of the titanium compound present is preferably 0.01 to 1.0 part by weight and more preferably 0.1 to 0.7 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having a Sn—O bond, a tin (II) compound having a Sn—X (X represents a halogen atom) bond, and the like. Preferably, a tin (II) compound having a Sn—O bond is more preferable.

Examples of tin (II) compounds having a Sn-O bond include tin (II) oxalate, tin (II) diacetate, tin (II) dioctanoate, tin (II) dilaurate, tin (II) distearate, diolein Carboxylic acid tin (II) having a carboxylic acid group having 2 to 28 carbon atoms such as tin (II) acid; dioctyloxy tin (II), dilauroxy tin (II), distearoxy tin (II), dioleoxy tin (II) Dialkoxytin (II) having an alkoxy group having 2 to 28 carbon atoms; tin oxide (II); tin (II) sulfate and the like having a Sn—X (X represents a halogen atom) bond include chloride. Examples thereof include tin (II) halides such as tin (II) and tin (II) bromide. Among these, (R ¹ COO) ₂ Sn (where R ¹ is a fatty acid tin represented by an alkyl or alkenyl group 5 to 19 carbon ^{atoms) (II), (R 2} O) 2 Sn ( wherein R ² is an alkyl group having 6 to 20 carbon atoms Dialkoxy tin (II) and tin oxide represented by SnO (II) is preferably represented by the alkenyl a group), (R ¹ COO) fatty tin represented by ₂ Sn (II) and tin oxide (II ) Are more preferred, and tin (II) dioctanoate, tin (II) distearate, and tin (II) oxide are more preferred.

  The abundance of the tin (II) compound is preferably 0.01 to 1.0 part by weight, more preferably 0.1 to 0.7 part by weight, based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.

  When the titanium compound and the tin (II) compound are used in combination, the total amount of the titanium compound and the tin (II) compound is preferably 0.01 to 1.0 part by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component, 0.1-0.7 weight part is more preferable.

  The polycondensation of the alcohol component and the carboxylic acid component can be performed, for example, at a temperature of 180 to 250 ° C. in an inert gas atmosphere in the presence of the esterification catalyst.

  The softening point of the polyester is preferably 90 to 160 ° C, more preferably 95 to 155 ° C, and still more preferably 100 to 150 ° C, from the viewpoints of fixability, storage stability and durability. The glass transition point is preferably 45 to 75 ° C, more preferably 50 to 75 ° C, and still more preferably 50 to 70 ° C, from the viewpoints of fixability, storage stability and durability. From the viewpoint of chargeability and environmental stability, the acid value is preferably 1 to 80 mgKOH / g, more preferably 5 to 60 mgKOH / g, further preferably 5 to 50 mgKOH / g, and the hydroxyl value is 1 to 80 mgKOH / g. Preferably, 8 to 50 mgKOH / g is more preferable, and 8 to 40 mgKOH / g is more preferable.

  In the polyester of the present invention, from the viewpoint of low-temperature fixability, offset resistance, and storage stability, the content of the low molecular weight component having a molecular weight of 500 or less due to the residual monomer component or oligomer component is 12% or less in the polyester. Preferably, it is 10% or less, more preferably 9% or less, and even more preferably 8% or less. The content of the low molecular weight component can be reduced by a method such as increasing the degree of fumaric acid modification of rosin.

  The polyester of the present invention may be a polyester modified to such an extent that the properties are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. Polyester.

  By using the polyester of the present invention as a binder resin for toner, it is possible to obtain a toner that is excellent in low-temperature fixability, offset resistance, storability and pulverization properties, and also has reduced odor during fixing. In the toner of the present invention, a known binder resin, for example, a vinyl resin such as styrene-acrylic resin, an epoxy resin, a polycarbonate, a polyurethane, or the like is used in combination as long as the effects of the present invention are not impaired. However, the content of the polyester of the present invention is preferably 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and substantially 100% by weight in the binder resin. More preferably.

  The toner of the present invention further includes a colorant, a release agent, a charge control agent, a magnetic powder, a fluidity improver, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, and an aging agent. Additives such as an inhibitor and a cleaning property improver may be appropriately contained.

  As the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow and the like can be used, and the toner of the present invention may be either a black toner or a color toner. The content of the colorant is preferably 1 to 40 parts by weight and more preferably 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

The toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion phase inversion method, or a polymerization method, but from the viewpoint of productivity and dispersibility of the colorant, A pulverized toner obtained by a melt kneading method is preferred. In the case of pulverized toner by melt kneading method, raw materials such as binder resin, colorant, charge control agent, etc. are uniformly mixed with a mixer such as a Henschel mixer, then a sealed kneader, a single or twin screw extruder, open It can be produced by melt-kneading with a roll-type kneader or the like, cooling, pulverizing and classifying. The volume median particle size (D ₅₀ ) of the toner is preferably 3 to 15 μm. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size.

  The toner of the present invention can be used as a one-component developing toner or as a two-component developer mixed with a carrier.

[Softening point of resin]
Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample is heated at a heating rate of 6 ° C / min, and a 1.96 MPa load is applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. . The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Glass transition point of resin and rosin (Tg)]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), weigh 0.01 to 0.02 g of the sample into an aluminum pan, raise the temperature to 200 ° C, and from that temperature to 0 ° C at a rate of 10 ° C / min. The temperature of the cooled sample is raised at a heating rate of 10 ° C / min, and the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent that indicates the maximum slope from the peak rise to the peak apex To do.

[Softening point of rosin]
(1) Sample preparation 10g of rosin is melted on a hot plate at 170 ° C for 2 hours. After that, it is naturally cooled for 1 hour in an open state at a temperature of 25 ° C. and a relative humidity of 50%, and then ground for 10 seconds in a coffee mill (National MK-61M).
(2) Measurement Using a flow tester (Shimadzu Corporation, CFT-500D), a 1g sample was heated at a heating rate of 6 ° C / min, and a load of 1.96MPa was applied by a plunger, with a diameter of 1mm and a length of 1mm. Extrude from nozzle. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Acid value of resin and rosin]
Measured according to the method of JIS K0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Hydroxyl value of the resin]
Measured according to the method of JIS K0070.

[Content of low molecular weight component having a molecular weight of 500 or less]
The molecular weight distribution is measured by gel permeation chromatography (GPC). Add 10 ml of tetrahydrofuran to 30 mg of toner, mix for 1 hour with a ball mill, filter with a fluororesin filter `` FP-200 '' (manufactured by Sumitomo Electric Industries) with a pore size of 2 μm to remove insoluble components, and remove the sample solution. Prepare.

Tetrahydrofuran is flowed as an eluent at a flow rate of 1 ml / min, the column is stabilized in a constant temperature bath at 40 ° C., and 100 μl of the sample solution is injected to perform measurement. In addition, “GMHLX + G3000HXL” (manufactured by Tosoh Corp.) is used as an analytical column, and several types of monodisperse polystyrene (2.63 × 10 ³ , 2.06 × 10 ⁴ , 1.02 × 10 ⁴ manufactured by Tosoh Corp.) are used for the molecular weight calibration curve. ^5. Prepare 2.10 × 10 ³ , 7.00 × 10 ³ , 5.04 × 10 ⁴ ) manufactured by GL Science as standard samples.

  The content (%) of the low molecular weight component having a molecular weight of 500 or less is calculated as the ratio of the area of the corresponding region in the chart area obtained by the RI (refractive index) detector.

[SP value of rosin]
After pouring 2.1 g of the molten sample into a predetermined ring, the sample is cooled to room temperature and then measured under the following conditions based on JIS B7410.
Measuring machine: Ring-and-ball automatic softening point tester ASP-MGK2 (manufactured by Meitec)
Temperature increase rate: 5 ℃ / min
Temperature rise start temperature: 40 ℃
Measuring solvent: Glycerin

[Fumaric acid modification degree of rosin]
Formula (A):

(Wherein X ₁ is the SP value of fumaric acid-modified rosin for calculating the degree of modification, X ₂ is the SP value of fumaric acid-modified rosin obtained by reacting 1 mol of fumaric acid and 0.7 mol of rosin, and Y is the rosin (Indicates SP value)
Calculated by The SP value indicated by X ₂ is that a mixture of 1 mol of fumaric acid, 0.7 mol of rosin and 0.4 g of t-butylcatechol was heated from 160 ° C. to 200 ° C. over 2 hours and reacted at 200 ° C. for 2 hours. The SP value of a fumaric acid-modified rosin obtained by further performing distillation under reduced pressure of 5.3 kPa. The molecular weight of the rosin 1 mol, when the acid value x (mg KOH / g), potassium hydroxide relative to the rosin 1 g (molecular weight: 56.1) that is xmg (x × 10 ^-3 g) reaction Therefore, formula (B):
Molecular weight = 56100 ÷ x (B)
Can be calculated.

[Volume-median particle diameter of toner (D ₅₀ )]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100 μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) 5% electrolyte dispersion condition: 10 mg of measurement sample is added to 5 ml of dispersion, and dispersed for 1 minute with an ultrasonic disperser. Then, 25 ml of the electrolytic solution is added, and further dispersed with an ultrasonic disperser for 1 minute.
Measurement conditions: Add 100 ml of electrolyte and dispersion in a beaker, measure 30,000 particles at a concentration that can measure the particle size of 30,000 particles in 20 seconds, and determine the volume-median particle size ( determine the D _50).

Example of purification of rosin 1000 g of tall rosin (Tg: 37.2 ° C) was added to a 2000 ml distillation flask equipped with a fractionation tube, reflux condenser and receiver, and distilled under a reduced pressure of 1 kPa. The distillate was collected as the main fraction. Hereinafter, tall rosin subjected to purification is referred to as unpurified rosin, and rosin collected as a main fraction is referred to as purified rosin (Tg = 39.2 ° C.).

  20 g of rosin was pulverized for 5 seconds with a coffee mill (National MK-61M), and 0.5 g was measured in a headspace vial (20 ml) after passing through a 1 mm sieve. Table 1 shows the results of sampling the headspace gas and analyzing the unpurified rosin and impurities in the purified rosin by the headspace GC-MS method.

[Measurement conditions for headspace GC-MS method]
A. Headspace sampler (Agilent, HP7694)
Sample temperature: 200 ℃
Loop temperature: 200 ° C
Transfer line temperature: 200 ° C
Sample heating equilibration time: 30min
Bayal pressurized gas: Helium (He)
Bayal pressurization time: 0.3min
Loop filling time: 0.03min
Loop equilibration time: 0.3min
Injection time: 1min

B. GC (Gas Chromatography) (Agilent, HP6890)
Analytical column: DB-1 (60m-320μm-5μm)
Carrier: Helium (He)
Flow rate condition: 1ml / min
Inlet temperature: 210 ° C
Column head pressure: 34.2kPa
Injection mode: split
Split ratio: 10: 1
Oven temperature condition: 45 ℃ (3min) -10 ℃ / min-280 ℃ (15min)

C. MS (mass spectrometry) (Agilent, HP5973)
Ionization method: EI (electron impact) method Interface temperature: 280 ℃
Ion source temperature: 230 ° C
Quadrupole temperature: 150 ° C
Detection mode: Scan 29-350m / s

Measurement of SP value of fumaric acid-modified rosin using unpurified rosin used as X ₂ value 332 g of unpurified rosin (SP value: 77.0 ° C) in a 1000 ml flask equipped with a fractionation tube, reflux condenser and receiver (1 mol), 81 g (0.7 mol) of fumaric acid and 0.4 g of t-butylcatechol were added, the temperature was raised from 160 ° C. to 200 ° C. over 2 hours, reacted at 200 ° C. for 2 hours, and then further 5.3 kPa Was distilled under reduced pressure to distill off unreacted fumaric acid and low-boiling substances to obtain fumaric acid-modified rosin. The SP value of the obtained fumaric acid-modified rosin, that is, the SP value of the fumaric acid-modified rosin using unpurified rosin was 130.6 ° C.

Measurement of SP value of fumaric acid-modified rosin using purified rosin used as X ₂ value Purified rosin (SP value: 76.8 ° C) 338 g (1) in a 1000 ml flask equipped with a fractionation tube, reflux condenser and receiver Mol), 81 g (0.7 mol) of fumaric acid and 0.4 g of t-butylcatechol, heated from 160 ° C. to 200 ° C. over 2 hours, reacted at 200 ° C. for 2 hours, and further reduced pressure to 5.3 kPa Under distillation, unreacted fumaric acid and low-boiling substances were distilled off to obtain fumaric acid-modified rosin. The SP value of the obtained fumaric acid-modified rosin, that is, the SP value of the fumaric acid-modified rosin using purified rosin was 130.9 ° C.

Production Example 1 of Fumaric Acid-Modified Rosin
Purified rosin (SP value: 76.8 ° C) 5408 g (16 mol), fumaric acid 928 g (8 mol) and t-butylcatechol 0.4 g were added to a 10 L flask equipped with a fractionation tube, reflux condenser and receiver. The temperature was raised from 160 ° C. to 200 ° C. over 2 hours, reacted at 200 ° C. for 2 hours, and then distilled under reduced pressure of 5.3 kPa to obtain fumaric acid-modified rosin A. The SP value of fumaric acid-modified rosin A was 130.8 ° C, the glass transition point was 74.4 ° C, and the degree of fumaric acid modification was 100.

Production Example 2 of Fumaric Acid Modified Rosin
Purified rosin (SP value: 76.8 ° C) 5408 g (16 mol), fumaric acid 557 g (4.8 mol) and t-butylcatechol 0.4 g were added to a 10 L flask equipped with a fractionation tube, reflux condenser and receiver. The temperature was raised from 160 ° C. to 200 ° C. over 2 hours, reacted at 200 ° C. for 2 hours, and then distilled under a reduced pressure of 5.3 kPa to obtain fumaric acid-modified rosin B. The SP value of fumaric acid-modified rosin B was 115.7 ° C., the glass transition point was 53.9 ° C., and the degree of fumaric acid modification was 72.

Production Example 3 of Fumaric Acid Modified Rosin
Purified rosin (SP value: 76.8 ° C) 5408 g (16 mol), fumaric acid 278 g (2.4 mol) and t-butylcatechol 0.4 g were added to a 10 L flask equipped with a fractionation tube, reflux condenser and receiver. After heating from 160 ° C. to 200 ° C. over 2 hours and reacting at 200 ° C. for 2 hours, distillation was further performed under a reduced pressure of 5.3 kPa to obtain fumaric acid-modified rosin C. The SP value of fumaric acid-modified rosin C was 98.4 ° C., the glass transition point was 48.3 ° C., and the degree of fumaric acid modification was 40.

Production Example 4 of Fumaric Acid Modified Rosin
To a 10 L flask equipped with a fractionation tube, reflux condenser and receiver, add 5312 g (16 mol) of unpurified rosin (SP value: 77.0 ° C), 928 g (8 mol) of fumaric acid and 0.4 g of t-butylcatechol. The mixture was heated from 160 ° C. to 200 ° C. over 2 hours, reacted at 200 ° C. for 2 hours, and further distilled under a reduced pressure of 5.3 kPa to obtain fumaric acid-modified rosin D. The SP value of fumaric acid-modified rosin D was 130.4 ° C, the glass transition point was 72.1 ° C, and the degree of fumaric acid modification was 100.

Examples 1-5, 7-9 and Comparative Example 1
A fractionation tube with hot water of 98 ° C., equipped with a reflux condenser that was passed through cold water at room temperature, an carboxylic acid component other than the alcohol component, trimellitic anhydride and esterification catalyst shown in Table 2, and nitrogen Place in a 5 liter four-necked flask equipped with an introduction tube, dehydration tube, stirrer, and thermocouple, conduct a polycondensation reaction at 160 ° C for 2 hours in a nitrogen atmosphere, and then increase the temperature to 210 ° C over 6 hours Thereafter, the reaction was carried out at 66 kPa for 1 hour. After cooling to 200 ° C, the trimellitic anhydride shown in Table 2 is added and reacted at normal pressure (101.3 kPa) for 1 hour, then heated to 210 ° C until the desired softening point is reached at 40 kPa. Reaction was performed to obtain a polyester.

Example 6
Fractionation of 98 ° C. warm water that is equipped with a reflux condenser with the alcohol component excluding glycerin, carboxylic acid component excluding trimellitic anhydride, and esterification catalyst shown in Table 2 passing through cold water at room temperature. Put into a 5 liter four-necked flask equipped with a tube, nitrogen inlet tube, dehydration tube, stirrer and thermocouple, and after a condensation polymerization reaction at 160 ° C for 2 hours in a nitrogen atmosphere, 210 ° C over 6 hours The reaction was continued for 1 hour at 66 kPa. After cooling to 180 ° C., glycerin shown in Table 2 was added, and the temperature was raised to 200 ° C. at 5 ° C./30 minutes. Furthermore, after reacting at 200 ° C. for 1 hour at normal pressure (101.3 kPa), the reaction was performed at 66 kPa for 1 hour. Then, trimellitic anhydride shown in Table 2 was added and reacted at normal pressure (101.3 kPa) for 1 hour, then heated to 210 ° C. and reacted at 40 kPa until the desired softening point was reached. Got.

Example of Toner Production 100 parts by weight of the polyester obtained in each of the examples and comparative examples shown in Table 3, 4 parts by weight of carbon black “MOGUL L” (manufactured by Cabot), negative charge control agent “Bontron S-34” After mixing 1 part by weight (manufactured by Orient Chemical Co., Ltd.) and 1 part by weight of polypropylene wax “NP-105” (manufactured by Mitsui Chemicals, Inc.) with a Henschel mixer, roll rotation speed using a co-rotating twin screw extruder Was melt-kneaded at 200 r / min and the heating temperature in the roll was 80 ° C. The obtained melt-kneaded product was cooled and coarsely pulverized, then pulverized with a jet mill and classified to obtain a powder having a volume median particle size (D ₅₀ ) of 8.0 μm.

  To 100 parts by weight of the obtained powder, 1.0 part by weight of “Aerosil R-972” (manufactured by Nippon Aerosil Co., Ltd.) as an external additive is added and mixed with a Henschel mixer to obtain toners 1 to 9 and comparative toner 1. It was.

Test Example 1 [Low-temperature fixability and offset resistance]
The toner is mounted on the printer “Page Presto N-4” (Casio Computer Co., Ltd., fixing: contact fixing method, developing method: non-magnetic one-component developing method, developing roll diameter: 2.3 cm), and the toner adhesion amount is 0.6 mg / An unfixed image was obtained by adjusting to cm ² . The fixing machine (fixing speed: 125mm / s) was improved so that the fixing machine of the AR-505 (Sharp Co.) copier with the contact fixing system can be fixed outside the machine. Using the fixing roll, the unfixed image was fixed while increasing the temperature of the fixing roll from 100 ° C. to 240 ° C. by 5 ° C., and a fixing test was performed.

  The image obtained at each fixing temperature was pasted with `` UNICEF Cellophane '' (Mitsubishi Pencil Co., Ltd., width 18 mm, JISZ-1522), passed through the fixing roll of the fixing machine set to 30 ° C., and then the tape was applied. The optical reflection density before and after peeling and tape peeling was measured using a reflection densitometer “RD-915” (manufactured by Macbeth). The fixing roller temperature at which the ratio between the two (after peeling / before peeling) first exceeded 90% was set as the minimum fixing temperature, and the low-temperature fixing property was evaluated according to the following evaluation criteria. At the same time, the occurrence of hot offset was visually observed, and the offset resistance was evaluated according to the following evaluation criteria. The results are shown in Table 3.

[Evaluation criteria for low-temperature fixability]
◎: Minimum fixing temperature is less than 150 ° C ○: Minimum fixing temperature is 150 ° C or more and less than 170 ° C △: Minimum fixing temperature is 170 ° C or more and less than 180 ° C ×: Minimum fixing temperature is 180 ° C or more

[Evaluation criteria for offset resistance]
A: Hot offset does not occur even at 240 ° C.
○: Hot offset occurs at 220 ° C or higher and 240 ° C or lower.
Δ: Hot offset occurs at 190 ° C or higher and lower than 220 ° C.
X: Hot offset occurs below 190 ° C.

Test Example 2 [Preservability]
Prepare two samples of 4 g of toner in an open cylindrical container with a diameter of 5 cm and a height of 2 cm. One is in an environment with a temperature of 40 ° C and a relative humidity of 60%, and the other is at a temperature of 55 ° C and a relative humidity of 60. % Environment for 72 hours. After leaving, the container containing the toner was shaken lightly to visually observe the presence or absence of toner aggregation, and the storage stability was evaluated according to the following evaluation criteria. The results are shown in Table 3.

〔Evaluation criteria〕
A: No aggregation of toner is observed at any temperature of 40 ° C. and 55 ° C.
○: No aggregation of toner is observed under an environment of 40 ° C., but slight aggregation particles of the toner are observed under an environment of 55 ° C.
Δ: Toner agglomeration particles are slightly observed under an environment of 40 ° C., and aggregation is clearly observed under an environment of 55 ° C.
X: Aggregation is clearly observed in any environment of 40 ° C and 55 ° C.

Test Example 3 [Crushability]
The polyesters of Examples and Comparative Examples were coarsely pulverized and sieved to obtain a resin powder that passed through a 16 mesh (aperture: 1 mm) sieve but did not pass through a 22 mesh (aperture: 710 μm) sieve. 10.00g of this classified resin powder is precisely weighed, pulverized for 30 seconds with a mill & mixer MM-I type (manufactured by Hitachi Living Supply Co., Ltd.), passed through a 30 mesh (opening: 500 μm) sieve, and does not pass. The weight (A) g of the resin was precisely weighed, and the residual rate was determined by the following formula. This operation was performed three times, and the average value was used as the grindability index, and grindability was evaluated according to the following evaluation criteria. The results are shown in Table 3.
Residual rate = (A) / resin weight before grinding (10.00 g) × 100

〔Evaluation criteria〕
◎: Grindability index is less than 5 ○: Grindability index is 5 or more and less than 15 ×: Grindability index is 15 or more

Test Example 4 [Odor]
20 g of toner was weighed into an aluminum cup and allowed to stand on a hot plate heated to 150 ° C. for 30 minutes, and the odor generated from the toner was evaluated according to the following evaluation criteria. The results are shown in Table 3.

〔Evaluation criteria〕
A: No odor is felt.
○: Almost no odor is felt.
Δ: Some odor is felt, but there is no practical problem.
X: Odor is felt strongly.

  From the above results, it can be seen that the toner containing the polyester of the example is excellent in low-temperature fixability, offset resistance, and pulverization properties, and has good storage stability even in a severe environment. On the other hand, the toner containing the polyester of Comparative Example 1 using unpurified rosin is not sufficient in preservability and grindability due to a large amount of low molecular weight components in the polyester, and has a problem with odor. I understand.

  The polyester for toner of the present invention is used as a binder resin for toner used for developing a latent image formed in electrophotography, electrostatic recording method, electrostatic printing method and the like.

Claims (7)

  A polyester for toner obtained by condensation polymerization of an alcohol component containing an aliphatic polyhydric alcohol and a carboxylic acid component containing a fumaric acid-modified rosin.   The polyester for toner according to claim 1, wherein the aliphatic polyhydric alcohol contains an aliphatic polyhydric alcohol having 2 to 6 carbon atoms.   The polyester for toner according to claim 1 or 2, wherein the content of the fumaric acid-modified rosin is 5 to 85% by weight in the carboxylic acid component.   The polyester for toner according to claim 1, wherein the fumaric acid-modified rosin is obtained by modifying a purified rosin with fumaric acid.   The polyester for toner according to claim 1, wherein the alcohol component and / or the carboxylic acid component contains a trivalent or higher alcohol and / or a trivalent or higher carboxylic acid compound.   The polyester for toner according to claim 1, wherein the condensation polymerization is performed in the presence of a titanium compound and / or a tin (II) compound having no Sn—C bond.   A toner comprising the toner polyester according to claim 1.