JPH08160667A - Manufacture of toner resin - Google Patents

Abstract

PURPOSE: To provide a resin having a high molecular weight and little odor by using a specific polymerization initiator when polymerizing a monomer mixer of styrene and (meta)ester acrylate to manufacture the toner resin. CONSTITUTION: A monomer mixture of styrene and (meta)ester acrylate is polymerized to manufacture a toner resin, and 'a compound having the basic skeleton expressed by the formula is used as a polymerization initiator. In the formula, (n) indicates an integer of 3-30. Polyazelaic acid diacylperoxide or polyazelaic acid diacyl peroxide modified by the 3,3,5-trimethyl butyroil peroxide group at the terminal is used for the compound having the basic skeleton expressed by the formula as a polymerization initiator. The condensation number (repetition unit number) of these polymeric peroxides is 3-30. When it is less than 3, only a polymer having a low molecular weight is obtained. When it exceeds 30, the viscosity of the polymeric peroxide is increased, and its handling becomes difficult.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high molecular weight resin used as a resin for toner.

[0002]

2. Description of the Related Art Conventionally, many inventions have been made on resins for dry toner. However, recently, the copying machine and the recording apparatus are required to improve the copying speed because the processing speed is increased with the increase of the processing information. Therefore, as a toner resin, there is a demand for a resin having higher performance than conventional ones, that is, more excellent in fixing property and offset resistance. There is also a demand for improvement of environmental deterioration due to the odor of the toner. It is known that a resin having a large molecular weight distribution is useful as a resin for toner containing a copolymer of styrene and a (meth) acrylic acid ester as a main component in order to improve offset resistance, blocking resistance and fixing property. Has been. As a method of obtaining such a resin, a method of producing a low molecular weight resin and a high molecular weight resin and blending the obtained resins, or a method of polymerizing a vinyl monomer in which the low molecular weight resin is dissolved is known. ing. Further, as a polymerization initiator for obtaining a high molecular weight resin, JP-A-2
-32108 and Japanese Patent Application Laid-Open No. 2-67302 disclose a method using 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane. Further, JP-A-58-72155 discloses 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 1,1. -Di-t-butylperoxy-
A method using a bifunctional peroxide such as 3,3,5-trimethylcyclohexane is disclosed.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Japanese Patent Application Laid-Open No. 2-67302 and Japanese Patent Application Laid-Open No. 58-
The polymer (resin) obtained by the method of Japanese Patent No. 72155 has an odor due to a decomposed product of the initiator, and a toner using the same also has a problem of leaving an odor.

[0004]

The present inventors have studied the problems of the above-mentioned conventional method for a long period of time, and as a result, solved the above problems by using a specific peroxide as a polymerization initiator. Has been completed. That is, according to the present invention, when a monomer mixture of styrene and a (meth) acrylic acid ester is polymerized to produce a resin for a toner, a basic skeleton represented by the general formula (1) is used as a polymerization initiator.

Embedded image (In the formula, n represents an integer of 3 to 30) The present invention relates to a method for producing a resin for toner, which comprises using a compound having a structure represented by the formula.

Examples of the compound having a structure represented by the general formula (1) as a basic skeleton which is used as a polymerization initiator in the present invention include polyazelaic acid diacyl peroxide,
Polyazelaic acid diacyl peroxide whose terminal is modified with 3,3,5-trimethylbutyroylperoxy group,
Examples thereof include polyazelaic acid diacyl peroxide whose terminal is modified with a benzoylperoxy group, and polyazelaic acid diacyl peroxide whose terminal is modified with a t-butylperoxy group. The condensation number (the number of repeating units) of these polymeric peroxides is 3 to 30, preferably 4 to 20. When it is less than 3, only low molecular weight polymers can be obtained. On the other hand, when it exceeds 30, the polymerization performance does not change, but the viscosity of the polymeric peroxide increases, and the handling thereof becomes difficult.

In the present invention, the amount of the polymerization initiator used varies depending on the type and combination of the monomers used, but usually 0.001 to 0.
5 mol, preferably about 0.005 to 0.2 mol. If it is less than 0.001 mol, the amount of residual monomers will increase, and if it exceeds 0.5 mol, it will be difficult to control the polymerization rate.

Further, in addition to the above-mentioned polymerization initiator, a polymerization initiator which has been conventionally used can be used in combination or can be additionally used in the latter half of the polymerization. Polymerization initiators that can be used in combination include 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, and benzoyl. Peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, 1,1-di-t-butylperoxy-3,3,5-
Examples include trimethylcyclohexane and t-butylperoxyisopropyl carbonate. Of these, benzoyl peroxide is particularly preferable because it has little odor.

The proportion of the polymerization initiator used in combination or added is such that the peroxide bond of the polymerization initiator represented by the general formula (1) is 1
Peroxide bond is 0.5 mol or less, preferably 0.3 mol or less. If it is used in excess of 0.5 mol, a high molecular weight product cannot be obtained, and due to its thermal decomposition product,
Odor is left in the obtained polymer, which is not preferable.

The (meth) acrylic acid ester used in the present invention includes methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate and lauroyl. Examples thereof include acrylic acid esters such as acrylate, and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate and lauroyl methacrylate. Of these, n-butyl acrylate is particularly preferable.

In the present invention, styrene and (meth) acrylic acid ester are usually in the range of 0.05 to 0.5 mol, preferably 0.1 to 0, per 1 mol of styrene. 0.3 mol. 0.05
If it is less than 0.5 mol, the fixing property of the toner will be deteriorated, and if it exceeds 0.5 mol, blocking of the toner will easily occur.
It should be noted that styrene and (meth) acrylic acid ester are not necessarily limited to monomers, and a low molecular weight resin composed of both may be contained. The amount of the resin is 200% by weight or less, preferably 100% by weight or less with respect to the monomer. If it exceeds 200% by weight, the initial viscosity of the monomer becomes high and a good polymerization state cannot be obtained. The weight average molecular weight of the low molecular weight resin is 30,000 or less, preferably 10,000 or less. If it exceeds 30,000, the fixing property of the toner is deteriorated.

In the present invention, the polymerization method is suspension polymerization,
Solution polymerization or bulk polymerization is used. A continuous polymerization method can also be used for solution polymerization or bulk polymerization. The polymerization temperature is 50 to 150 ° C., preferably 70 to 130 ° C., and constant temperature or programmed temperature rising polymerization is used. When the temperature is 50 ° C. or lower, the polymerization rate decreases, and when the temperature is 130 ° C. or higher, it is difficult to control the polymerization rate, which is not preferable.

[0012]

According to the method for producing a resin for toner of the present invention, a resin having a high molecular weight and a small odor can be obtained by using a specific polymerization initiator. In addition, it has excellent fixability and anti-offset property, so its industrial utility value is extremely high.

[0013]

Next, the present invention will be described in more detail with reference to examples. In the examples, parts and% are parts by weight and% by weight, unless otherwise specified. The abbreviations in the examples indicate the following compounds. AZ1: polyazelaic acid diacyl peroxide (repeating unit 10, molecular weight 1900, active oxygen amount 7.38)
% By weight) AZ2: polyazelainic acid diacyl peroxide whose terminal is modified with 3,3,5-trimethylbutyroylperoxy group (repeating unit 9, molecular weight 1950, active oxygen amount 7.10% by weight) PTA: 2,2- Bis (4,4-di-t-butylperoxycyclohexyl) propane 25Z: 2,5-dimethyl-2,5-di (benzoylperoxy) hexane BPO: benzoyl peroxide St: styrene BA: n-butyl acrylate

Various evaluations in the examples were carried out by the following methods. Toner odor: The presence or absence of a peroxide decomposition odor in the manufactured toner was judged by a sensory test. Fixability: Image density (ID) before and after peeling when a cellophane tape is attached to the fixed toner image and then peeled.
The fixing lower limit temperature is the temperature of the fixing roller at which the attenuation of 80% at ID 0.6 is 80%. Offset resistance: The degree of contamination of the fixing roller with toner was visually determined and evaluated at the lowest temperature at which contamination started. The method used was a fixing tester in which the fixing unit of the copying machine was modified using the manufactured toner, and a process speed of 130 mm /
The results of evaluation of the fixability and the anti-offset property at sec and a pressure of 40 kg are shown by the lower limit fixing temperature of the fixability and the lowest contamination start temperature of the offset property. The larger the range of the lower limit temperature of fixing and the lower limit temperature of contamination start, the better.

[Production of low molecular weight polymer] After 100 parts of xylene was added to a reactor, the boiling point of xylene was 135 ° C.
Raise the temperature to a certain degree. Then 80 parts of styrene and B
A solution prepared by dissolving 50 parts of xylene and 6 parts of azobisisobutyronitrile in a mixture of 20 parts of A is 135-1.
Polymerization was carried out by dropwise addition at 45 ° C. over 5 hours. After this, about 1
145-1 after stirring for a period of time while maintaining the system temperature
The solvent was removed by heating to 60 ° C. The weight average molecular weight of the obtained polymer was 6000.

Example 1 2 liters of ion-exchanged water was added to a 5 liter autoclave.
Calcium phosphate 10 g, sodium dodecylbenzene sulfonate (produced by NOF CORPORATION, trade name NEWLEX R)
0.4 g, AZ1 4.3 g, St 800 g and BA
After adding 200 g and substituting the space with nitrogen, polymerization was carried out at 70 ° C. for 3 hours with stirring, and further polymerization was continued for 4 hours 40 minutes while raising the temperature to 70 to 110 ° C. by 15 ° C. per hour. After cooling, the contents were taken out, washed with hydrochloric acid, washed with water and dried. The residual monomer of the obtained resin was quantified by gas chromatography (hereinafter abbreviated as GLC). As a result, the residual monomer was 0.08%. As a result of measuring the molecular weight by gel permeation (hereinafter abbreviated as GPC), the number average molecular weight was 162,000 and the weight average molecular weight was 537,000. Then the obtained polymer 75
2 g and 188 g of the above low molecular weight polymer, 50 g of carbon black (# 40 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) and a charge control agent (Bontron S-34 manufactured by Orient Chemical Industry Co., Ltd.)
Knead 10 g at 150 ° C. for about 5 minutes using a twin-screw extruder,
After cooling, finely pulverize with a jet mill, particle size 5 to 15μ
The toner was used. The obtained toner had neither monomer odor nor peroxide decomposition odor. Then, the above toner was used to evaluate the fixability and the offset resistance. As a result, the fixability was 175 ° C and the offset resistance was 240 ° C. Generally, the practical limit of fixability is 1.
80 ° C or lower, practical limit of offset resistance is 230
℃ or above. The results are shown in Table 1.

[0017]

[Table 1]

Example 2 and Comparative Examples 1 to 3 The procedure of Example 1 was repeated except that the polymerization initiators shown in Table 1 were used. The results are shown in Table 1. The toners obtained in Example 2 have no peroxide decomposition odor, and the toners obtained in Comparative Examples 1 and 2 are excellent in fixing property and offset resistance. A decomposed odor was observed. In addition, the polymer obtained in Comparative Example 3 was a relatively low molecular weight product. Further, the polymer obtained in Comparative Example 1 is slightly inferior to Examples 1 and 2 in fixability and offset resistance of the obtained toner, and Comparative Examples 2 and 3 are inferior in fixability and offset resistance. Recognize.

Example 3 St / BA (8) was added to a continuous first-stage reactor in which two reactors each having a stirrer with an internal capacity of 5 liters were connected in series as a polymerization tank.
(0/20 weight ratio mixture) A liquid in which 50 g of ethylbenzene and 2.18 g of a polymerization initiator AZ1 were dissolved per 1000 g was supplied so that the average residence time of each reactor was 1 hour, and the polymerization temperature of each reactor was 120 ° C. Adjusted to. After 10 hours of continuous polymerization, a part of the polymer discharged from the second-stage reactor was sampled, and most of the remaining polymer was
Unreacted styrene and solvent were removed through a demonomerizing apparatus set at a temperature of 220 ° C. and a pressure of 50 mmHg. The sampling polymer had a conversion of polymerization of 57%, a number average molecular weight of 142,000 and a weight average molecular weight of 294,000. The obtained polymer was tested according to Example 1, and as a result, the decomposed odor of peroxide was not observed in the obtained toner. The fixability was 175 ° C. and the offset resistance was 240 ° C.

Comparative Example 4 In Example 3, PT was replaced by PT instead of AZ1.
It implemented according to Example 3 except having used A. As a result, the polymerization conversion of the polymer was 73%, and the number average molecular weight was 12
The weight average molecular weight was 1,000 and 252,000. As a result of testing according to Example 1 using the obtained polymer,
The obtained toner was found to have a decomposed odor of peroxide. The fixing property is 170 ° C and the offset resistance is 1
It was 90 ° C.

Example 4 In Example 1, St 800 g and BA 200
1000 g of St / BA (8: 2) copolymer having a weight average molecular weight of 11,000 produced by a solution polymerization method instead of g
g was dissolved in a monomer mixture of 800 g of St and 200 g of BA, and the amount of AZ1 used was changed to 8.6 g. As a result, the residual monomer content was 0.28%. As a result of measuring the molecular weight by GPC, the peak had two peaks and the weight average molecular weight on the high molecular weight side was 599000. The obtained polymer was tested according to Example 1, and as a result, the decomposed odor of peroxide was not observed in the obtained toner. The fixability is 17
The offset resistance was 240 ° C.

Comparative Example 5 The procedure of Example 5 was repeated except that PTA was used instead of AZ1. As a result, the residual monomer content was 0.39%. As a result of measuring the molecular weight by GPC, the peak had two peaks and the weight average molecular weight on the high molecular weight side was 520000. The obtained polymer was tested according to Example 1, and as a result, the obtained toner had a decomposed odor of peroxide. The fixability was 180 ° C and the offset resistance was 230 ° C.

Claims (1)

[Claims] 1. When a monomer mixture of styrene and a (meth) acrylic acid ester is polymerized to produce a toner resin, a basic skeleton as a polymerization initiator is represented by the general formula (1): (In the formula, n represents an integer of 3 to 30). A method for producing a resin for toner, comprising using a compound having a structure represented by the formula.