JPH0551010B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a binding resin, and more specifically, for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to binding resins particularly useful in developer compositions for [Prior art and problems] As a conventional electrophotographic method, US Patent No. 2297691
As stated in the specification of No. 2357809, etc.
A photoconductive insulating layer is uniformly charged, the layer is then exposed to light, and the charge on the exposed portions is dissipated to form an electrical latent image, and the latent image is injected with toner. After the visible image is transferred to a transfer material such as transfer paper (transfer process), heat and pressure are applied. Alternatively, it consists of a step of permanently fixing (fixing step) by another suitable fixing method. As described above, the toner must have the functions required not only in the development process but also in each of the transfer and fixing processes. Generally, toner is subjected to mechanical frictional force due to shearing force and impact force during mechanical operation in a developing device, and deteriorates while copying several thousand to tens of thousands of sheets.
To prevent such toner deterioration, it is best to use a strong resin with a large molecular weight that can withstand mechanical friction, but these resins generally have a high softening point and are suitable for non-contact fixing methods such as oven fixing and infrared fixing. With radiant fixing, the thermal efficiency is poor, so fixing is not sufficient.Also, with the contact fixing method, which has good thermal efficiency, even in the widely used heat roller fixing method, the temperature of the heat roller has to be adjusted to ensure sufficient fixing. It becomes necessary to increase the
Not only does this cause problems such as curling of paper and increased energy consumption, but also the use of such resin significantly reduces production efficiency when producing toner by pulverizing it into powder. Therefore, binder resin (binding resin)
It is not possible to use materials whose polymerization degree and softening point are too high. On the other hand, in the heat roller fixing method, the heating roller surface and the toner image surface of the sheet to be fixed are in pressure contact, so the thermal efficiency is extremely high and it is widely used from low speeds to high speeds. When doing so, a so-called offset phenomenon is likely to occur, in which toner adheres to the surface of the heating roller and is transferred to subsequent transfer paper or the like. To prevent this phenomenon, the surface of the heating roller is treated with a material with excellent mold release properties such as fluorine-based resin, and in addition, a mold release agent such as silicone oil is applied to the surface of the heating roller to completely prevent the offset phenomenon. are doing. However, the method of applying silicone oil or the like is not preferable because it not only increases the size of the fixing device and increases the cost, but also makes it complicated, which can easily cause trouble. Furthermore, as described in Japanese Patent Publication No. 55-6895 and Japanese Patent Application Laid-Open No. 56-98202, there is a method to improve the offset phenomenon by widening the molecular weight distribution width of the binder resin, but the degree of polymerization of the resin increases and the fixation becomes difficult. The temperature also needs to be high. As a further improved method, Special Publication No. 57-493,
As described in JP-A-50-44836 and JP-A-57-37353, there is a method of improving the offset phenomenon by making the resin asymmetrical and crosslinking, but the fixing point has not been improved. Generally, the minimum fusing temperature is between cold offset and hot offset, so the usable temperature range is
It is between the minimum fixing temperature and hot offset, and by lowering the minimum fixing temperature as much as possible and raising the minimum hot offset temperature as much as possible, it is possible to lower the usable fixing temperature and expand the usable temperature range, which saves energy. , high-speed fixing, and prevents paper from curling. In addition, since double-sided copying can be performed without trouble, copying machines have become more intelligent, and the temperature control of the fixing device has become more accurate.
There are many advantages such as relaxing the tolerance range. Therefore, resins and toners with good fixing properties and offset resistance are always desired. In addition, when using a styrene-based binder resin to achieve such requirements, Japanese Patent Application Laid-Open No. 49-65232,
As described in JP-A-50-28840 and JP-A-50-81342, methods of adding paraffin wax, low molecular weight polyolefin, etc. as offset preventive agents are known, but they are not effective if the amount added is small. It has been confirmed that if the amount is too large, the developer deteriorates quickly, and in the case of polyester resin, even if the offset preventive agent mentioned above is applied, it has little effect, and if the amount used is too large, the developer deteriorates quickly. Polyester resin inherently has good fixing properties, and as described in U.S. Pat. No. 3,590,000, it can be fixed sufficiently even in a non-contact fixing method, but it is prone to offset phenomenon and cannot be used in a heat roller fixing method. was difficult. As described in JP-A-50-44836, JP-A-57-37353, and JP-A-57-109875, polyester resins that use polycarboxylic acids and have improved offset resistance are sufficient for use. Polyester resins do not have offset resistance, or those that do not only sacrifice the low-temperature fixing properties inherent to polyester resins, but also have extremely poor crushability in the toner forming process. There were also problems with developer production. The present invention has been made to meet these demands, and its purpose is to prevent offset without applying an anti-offset liquid in a heat roller fixing system, fix at a lower fixing temperature, and use a developer. The purpose of the present invention is to provide a binder resin for a developer that has good kneading and pulverizing properties during production. Another object of the present invention is to provide a binder resin for a developer that has good fluidity, does not cause blocking, and has a long life (hard to deteriorate). Another object of the present invention is to provide a toner binder resin that is inherently strongly negatively chargeable and provides a toner that forms clear and fog-free images in a dry developer for electrophotography. The object of the present invention is to provide a binding resin for toner which has improved the above-mentioned drawbacks, is extremely unaffected by environmental humidity, has excellent durability, and has negative triboelectric charging properties. Another object of the present invention is to provide a method for producing a binding resin used in a clear color developer with good transparency. Another object of the present invention is to provide a method for producing a binder resin used in a developer that does not cause fusion with the file or transfer of images to the film even when stored in a file. [Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors conducted intensive research and arrived at the present invention. That is, the present invention provides (a) the following general formula (In the formula, R represents an ethylene or propylene group, x and y each represent an integer of 1 or more,
And the average value of x+y is 2-7. ) A method for producing a binder resin by cocondensation polymerization of a diol component represented by (b) an acid component which is a divalent or higher carboxylic acid, an acid anhydride thereof, or a lower alkyl ester thereof, wherein the acid component is α-methylstyrene or/and the following general formula (In the formula, R ₁ represents a hydrocarbon group having 1 to 3 carbon atoms or hydrogen) and the following general formula: (In the formula, R ₂ and R ₃ represent hydrogen, a methyl group, or a carboxyl group.) The present invention relates to a method for producing a binding resin characterized by the following. Examples of the diol component (a) in the present invention include polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (3.3)-2,2-bis(4-hydroxyphenyl) phenyl)propane, polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)
Propane, polyoxypropylene (2.0)-polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene
(6)-2,2-bis(4-hydroxyphenyl)propane and the like can be mentioned. In addition, other polyols may be used, such as polyoxypropylene (12)-2,2-bis(4-hydroxyphenyl)propane, polyoxyphenylethylene(3)-2,2-bis(4-hydroxyphenyl). ) Propane, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, neopentyl glycol, p-
Xylylene glycol, m-xylylene glycol, 1,4-cyclohexanedimethanol, 1,
4-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,3-cyclohexanedimethanol, glycerin, polyoxyethylene (6)
Glycerin, polyoxypropylene (12) pentaerythritol, etc. can be added to the polyol component in an amount of about 10 mol% or less, but polyoxyphenylethylene (3)-2,2-bis (4-hydroxyphenyl) propane, The reaction is difficult to proceed with substances with high steric hindrance, such as glycerin, polyoxyethylene (6)
Resins containing highly hydrophilic polyols such as pentaerythritol tend to deteriorate the image quality of the developer, so care must be taken. Further, in the present invention, the compound represented by formula (a) includes, for example, styrene, methylstyrene,
Examples include ethylstyrene and propylstyrene. Further, in the present invention, examples of the compound represented by formula (b) include maleic acid, fumaric acid, acrylic acid, methacrylic acid, and itaconic acid. These may be acid anhydrides or esters of lower alkyl groups. The meaning of the lower alkyl group here is an alkyl group of such a size that the alkyl of the alkyl ester does not interfere with the copolymerization of the compound of formula (a) and the compound of formula (b). Further, the compound of formula (a) is preferably used in an amount of 1 to 5 moles per mole of the compound of formula (b) for copolymerization. Specific examples of the polyhydric carboxylic acid () in the present invention are shown below, but in order to control the reaction and bring it closer to the required performance, it is also possible to use one in which a part of the carboxylic acid group is substituted with an alkyl ester. Compound (1) Average molecular weight 1500 Compound (2) Average molecular weight 2000 Compound (3) Average molecular weight 1000 Compound (4) Average molecular weight 1200 Compound (5) Average molecular weight: 4000 These polyhydric carboxylic acids () or their acid anhydrides or their lower alkyl esters are contained in the acid component.
It is preferably contained in an amount of 0.05 to 70 mol%. In addition, the acid component of the present invention contains the following general formula () (However, R ₄ is an alkyl group or an alkenyl group having 4 to 18 carbon atoms.) It can contain an alkyl or alkenyl succinic acid, an acid anhydride thereof, or a lower alkyl ester thereof. As the alkyl or alkenyl succinic acid, n
-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid, n-butylsuccinic acid, and the like. By using alkyl or alkenyl succinic acid, it is possible to lower the minimum fixing temperature without lowering the offset generation temperature, but if it is too little, the effect will be weak, and if it is too much, the Tg will decrease and toner caking will easily occur. This makes it difficult to control the reaction. Therefore, its content is preferably 1 to 50 mol% in the acid component. Further, divalent carboxylic acids other than alkyl or alkenylsuccinic acids that can be used in the present invention include fumaric acid, maleic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, , 6-naphthalene dicarboxylic acid and the like. In addition, the present invention may optionally contain trivalent or higher polycarboxylic acids such as trimellitic acid, pyromellitic acid, cyclohexanetricarboxylic acid, etc. in the acid component, and trivalent or higher polyhydric alcohols such as glycerin,
It is also possible to contain trimethylolpropane, sorbitol, pentaerythritol, etc. as a regulator. The softening point (ring and ball softening point according to ASTM E-28-51T) of the binding resin obtained by the method of the present invention is preferably 90 to 180°C. The binding resin obtained according to the present invention is used in toners for electrostatic charge development produced by conventional methods. That is, the resin produced according to the present invention can be used as a coloring agent, for example, in the case of a black toner, various carbon blacks produced by a thermal black method, an acetylene black method, a channel black method, a furnace black method, a lamp black method, etc. , for color toners, copper phthalocyanine, monoazo pigments (CIPigment Red 5, CIPigment
Orange 36, CI Pigment Red 22), disazo pigment (CIPigment Yellow 83), anthraquinone pigment (CIPigment Blue 60), disazo dye (Solvent Red 19), rhodamine dye (Solvent Red 49), etc. After sufficiently uniformly dispersing the mixture, the mixture is melt-kneaded in a kneader, cooled, and pulverized, and used as a toner having an average particle size of 5 to 15 μm. Further, magnetic fine powder can also be used in the developing mechanism or for the purpose of improving images. Examples of the magnetic powder include alloys or compounds containing elements exhibiting ferromagnetism, such as ferrite and magnetite. It can be used in a dispersed amount of 70% by weight. Also, known property improving agents contained in toners using the binding resin of the present invention include offset inhibitors, flow agents, charge control agents, etc., but even if used appropriately, they do not interfere with the present invention. It's not a thing. [Examples] Examples of the present invention will be described below, but the present invention is not limited to these examples. Example 1 3.5 kg of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 1.04 kg of fumaric acid, 132 g of dodecenyl succinic anhydride, and the above compound (1) 110 as polyhydric carboxylic acid ()
g was placed in a 4-neck glass flask with 3 g of hydroquinone, equipped with a thermometer, a stainless steel stirring rod, a dehydration tube equipped with a reflux condenser, and a nitrogen introduction tube, and heated in an electric heating mantle under a nitrogen stream.
The reaction was carried out at 200°C with stirring. The degree of polymerization is
Tracking was performed from the softening point according to ASTM E28-51T, and the reaction was terminated when the softening point reached 125°C.
The obtained resin was a pale yellow solid, and the glass transition temperature measured by DSC (differential calorimetry) was 59°C. Example 2 Polyoxyethylene(2)-2,2-bis(4-hydroxyphenyl)propane 1.58Kg, polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 1.78Kg, terephthal acid 830
g, fumaric acid 464g, dodecenyl succinic anhydride
132 g and 162 g of the compound (2) as a polyhydric carboxylic acid () were placed in the same apparatus as in Example 1 together with 3 g of hydroquinone, and a resin was produced in the same manner as in Example 1. When the softening point reached 125°C, the reaction occurred. has ended.
The obtained resin was a pale yellow solid with a glass transition point of 60°C. Example 3 Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane 2848g, 2,
2-dimethyl-1,3-propanediol 208g,
Fumaric acid 928g, dodecenyl succinic anhydride 264g
and the above compound (3) as the polyhydric carboxylic acid ()
Example 1: 616.5g with 3g of hydroquinone
A resin was produced using the same procedure as above, and the reaction was terminated when the softening point reached 123°C.
The obtained resin was a pale yellow solid with a glass transition temperature of 62°C. Example 4 Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane 3560 g, isophthalic acid 1245 g, octyl succinic anhydride 104
g and polyhydric carboxylic acid () as the compound (4)
1,717 g of the resin was put into the same apparatus as in Example 1 together with 3 g of hydroquinone, and a resin was produced in the same manner as in Example 1. The reaction was terminated when the softening point reached 125°C.
The resulting resin was a pale yellow solid with a glass transition temperature of 65°C. Example 5 3.5Kg of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 1.097Kg of fumaric acid and 110g of the above compound (1) as polycarboxylic acid () were carried out with 3g of hydroquinone. The resin was placed in the same apparatus as in Example 1, and a resin was produced in the same manner as in Example 1, and the reaction was terminated when the softening point reached 125°C. The resulting resin is a pale yellow solid;
Glass transition temperature measured by DSC (differential calorimeter) is 61℃
It was hot. Example 6 Polyoxyethylene(2)-2,2-bis(4-hydroxyphenyl)propane 1.58Kg, polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 1.78Kg, terephthal acid 830
g, fumaric acid 521g and polyhydric carboxylic acid ()
162 g of the compound (2) and 3 g of hydroquinone were placed in the same apparatus as in Example 1, a resin was produced in the same manner, and the reaction was terminated when the softening point reached 125°C. The obtained resin was a pale yellow solid with a glass transition point of 62°C. Example 7 Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane 2848g, 2,
2-dimethyl-1,3-propanediol 208g,
1042 g of fumaric acid and 616.5 g of the above compound (3) as a polycarboxylic acid () were placed in the same apparatus as in Example 1 together with 3 g of hydroquinone, and a resin was produced in the same manner as in Example 1 until the softening point reached 121°C. The reaction was terminated when The resulting resin was a pale yellow solid with a glass transition temperature of 65°C. Example 8 3560 g of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, 1326 g of isophthalic acid, and 1717 g of the above compound (4) as a polyhydric carboxylic acid () were combined with 3 g of hydroquinone in Example 1 A resin was produced using the same procedure as above, and the reaction was terminated when the softening point reached 125°C. The obtained resin was a pale yellow solid with a glass transition temperature of 67°C. Comparative Example 1 A resin was produced using exactly the same process as in Example 1 except that compound (1) was removed and fumaric acid was increased to adjust the ratio of carboxyl groups to hydroxyl groups, that is, 1102 g, and softened. The reaction was terminated when the point reached 125°C. The resulting resin was a pale yellow solid with a glass transition temperature of 58°C. Comparative Example 2 A resin was produced in exactly the same manner as in Example 1 except that 110 g of trimellitic acid was added instead of compound (1), and the reaction was terminated when the softening point reached 125°C. The resulting resin is a pale yellow solid;
The glass transition temperature was 59°C. Evaluation example 1 90 parts by weight of the resin obtained in Example 1 and 10 parts of carbon black (Regal 400R manufactured by Cabot)
Parts by weight were mixed in a ball mill, then kneaded, pulverized, and classified to obtain a toner with an average particle size of 12.5 μm. The obtained toner was mixed with carrier iron powder (manufactured by Nippon Tetsuko Co., Ltd.; EFV).
200/300) and measured the amount of charge using a blow-off type charge amount measuring device, it was -23 μc/g. 91 g of the toner was mixed with 1209 g of carrier iron powder (manufactured by Nippon Tetsuko Co., Ltd.; EFV200/300) to prepare a developer.
When the image was produced using a fixing device (with the heat roller temperature in the fixing device variable at mm/sec and the oil coating device removed), a clear image was obtained with no background smudges, smearing, or missing solid black areas. Ta. When the fixing temperature of the fixing device was controlled between 140℃ and 220℃ and the image fixation and offset properties were evaluated, the result was 142.
It was sufficiently fixed at ℃, and no hot offset occurred. After printing up to 50,000 images,
Clear images were obtained with no background fogging or missing solid black areas. The minimum fixing temperature here is 15mm x 7.5mm on the bottom.
A load of 500 g was placed on a sand eraser, and the image fixed through the fixing machine was rubbed back and forth 5 times. The optical reflection density was measured using a Macbeth reflection densitometer before and after rubbing, and the fixing rate was determined by the following definition. This refers to the temperature of the fixing roller when it exceeds 70%. Fixation rate = Image density after rubbing/Image density before rubbing (However, the image density before rubbing has an OD value of 0.50) Evaluation examples 2 to 10 Examples 2 to 8 and Comparative examples 1 to 2 Exactly the same evaluation was performed on the resin obtained in , and the results are shown in Table 1. Note that the results of Evaluation Example 1 are also shown. 【table】

Claims (1)

[Claims] 1 (a) The following formula (In the formula, R represents an ethylene or propylene group, x and y each represent an integer of 1 or more,
And the average value of x+y is 2-7. ) A diol component represented by is α-methylstyrene or/and the following general formula (In the formula, R ₁ represents a hydrocarbon group having 1 to 3 carbon atoms or hydrogen) and the following general formula: (In the formula, R ₂ and R ₃ represent hydrogen, a methyl group, or a carboxyl group.) A method for producing a binding resin characterized by: 2 (a) The following formula (In the formula, R represents an ethylene or propylene group, x and y each represent an integer of 1 or more,
And the average value of x+y is 2-7. ) A diol component represented by is α-methylstyrene or/and the following general formula (In the formula, R ₁ represents a hydrocarbon group having 1 to 3 carbon atoms or hydrogen) and the following general formula: (In the formula, R ₂ and R ₃ represent hydrogen, a methyl group, or a carboxyl group) A polyhydric carboxylic acid () or its acid anhydride or its lower alkyl ester and the following general A method for producing a binding resin comprising a divalent carboxylic acid represented by the formula (), an acid anhydride thereof, or a lower alkyl ester thereof. (However, R ₄ is an alkyl group or alkenyl group having 4 to 18 carbon atoms). 3 The content of polyhydric carboxylic acid () or its acid anhydride or its lower alkyl ester in the acid component
The manufacturing method according to claim 2, wherein the binding resin has a ring and ball softening point of 90 to 180°C. 4 The content of the divalent carboxylic acid represented by the general formula () or its acid anhydride or its lower alkyl ester in the acid component is 1 to 50 mol%, according to claim 2 or 3. Production method.