JPH03213873A - Release agent for electrophotographic toner - Google Patents

Abstract

PURPOSE:To increase a hot offset temp. and to prevent the degradation on flowability by forming the release agent of a modified polyolefin resin modified by an org. fluorine compd. or this resin and a polyolefin resin and specifying the content of fluorine atoms, the melt viscosity at 160 deg.C and Durometer hardness. CONSTITUTION:The release agent for electrophotograhic toners which consists of the modified polyolefin resin modified by the org. fluorine compd. or this resin and the polyolefin resin and has 0.001 to 5% content of the fluorine atoms based on the weight of release agent, <=1000cps melt viscosity at 160 deg.C and >=30 Durometer hardness is used. The polyolefin resin is exemplified by a low- melt viscosity polyolefin resin. The electrophotographic toner which is not degraded in the flowability and has excellent hot offset resistance is obtd. in this way.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a release agent for electrophotographic toner.

More specifically, the present invention relates to a release agent for electrophotographic toner that has excellent hot offset properties and is suitable for heat-fixing type copying machines or printers.

[Prior Art] A heat fixing toner is fixed on a support by a heat roll. In this case, it is desired that the lower limit temperature of fixing is low. On the other hand, when the roll temperature increases, a phenomenon occurs in which toner sticks to the roll.

It is desirable that the temperature at which this hot offset occurs is high. Generally, as the molecular weight of the binder increases, the hot offset temperature increases, but at the same time, the minimum fixing temperature also increases. Conversely, when the molecular weight decreases, both the hot offset temperature and the lower limit fixing temperature decrease.

As a method for meeting this contradictory performance requirement, an electrophotographic toner is known in which a release agent (for example, low molecular weight polypropylene) is added to increase the hot offset temperature (for example, Japanese Patent Publication No. 3304/1982).

[Problems to be Solved by the Invention] However, when a polyolefin resin such as low molecular weight polypropylene is added, the fluidity of the toner may be reduced or the expected sufficient hot offset temperature may not be obtained.

[Means for Solving the Problems] The present inventors have conducted intensive studies on a release agent for electrophotographic toners that has a high hot offset temperature and does not reduce the fluidity of the toner, and as a result, has arrived at the present invention. That is, the present invention is a modified polyolefin resin modified with an organic fluorine compound, or a polyolefin resin comprising the same, and the content of fluorine atoms is 0.001 to 5% based on the weight of the mold release agent.
and the melt viscosity at IH"C is 1000 cps
The following is a release agent for electrophotographic toner characterized by a durometer hardness of 30 or more.

The polyolefin resin according to the present invention includes a low melt viscosity polyolefin resin, for example 1): low melt viscosity polyethylene, polypropylene, ethylene-α olefin (
carbon fi 3-8) copolymers (e.g., ethylene-propylene copolymers), 2): Maleic acid derivatives of 1) (maleic anhydride, maleic acid dimethyl ester, maleic acid diethyl ester, maleic acid di-2-ethylhexyl ester, etc.) ) adduct, 3): oxide of I), 4): ethylenically unsaturated carboxylic acid ((meth)acrylic acid, itaconic acid, etc.) and/or its ester (alkyl (1 to 18 carbon atoms) ester), etc. and ethylenically unsaturated hydrocarbons (ethylene, propylene, butene, etc.), and mixtures thereof.

As a method for producing a low melt viscosity polyolefin resin, l)
is a high melt viscosity polyolefin resin at a temperature of 300 to 45
It can be obtained by thermal degradation at 0° C. reaction time of 0.5 to IO hours, or by single or copolymerization of olefins using known polymerization methods.

2) can be obtained by subjecting the low melt viscosity polyolefin resin of 1) to an addition reaction with a maleic acid derivative in the presence of a peroxide catalyst or in the absence of a catalyst. 3) can be obtained by oxidizing the low melt viscosity polyolefin of l) with oxygen or an oxygen-containing gas (air), or by oxidizing ozone-containing oxygen or ozone-containing gas (air). The acid value of the oxide is normal! 00 or less, preferably 50 or less. 4) is obtained by copolymerization of an ethylenically unsaturated carboxylic acid and/or alkyl ester (having 1 to 18 carbon atoms) and an ethylenically unsaturated hydrocarbon. The amount of ethylenically unsaturated carboxylic acid and/or its alkyl ester is usually 30% or less, preferably 20% or less, based on weight.

In the modified polyolefin resin modified with an organic fluorine compound according to the present invention, the organic fluorine compound may be a fluorine compound containing a group having an olefinic double bond (for example, a fluorinated olefin (hexafluoropropylene, perfluorohexylethylene, etc.). ), fluorinated alkyl (meth)acrylic acid esters (perfluorohexaethyl methacrylate, perfluorooctylethyl methacrylate, etc.), and the like.

When modifying the polyolefin resin with an organic fluorine compound, the amount of the organic fluorine compound is such that the content of fluorine atoms is 0.001 to 5% based on the weight of the mold release agent. When used as an electrophotographic toner with o, oot% ungrooved,
Does not exhibit sufficient liquidity. If it exceeds 5%, the polyolefin resin will not exhibit good melting properties and will not exhibit a sufficient hot offset temperature when used as an electrophotographic toner.

Although the method of modifying the polyolefin resin according to the present invention with an organic fluorine compound is not particularly limited,
) A method of modifying a low melt viscosity polyolefin resin with an organic fluorine compound, or thermally degrading a high melt viscosity polyolefin resin modified with an organic fluorine compound in B).

Examples of the method of modifying the low melt viscosity polyolefin resin in A) with an organic fluorine compound include a method in which an organic fluorine compound is subjected to an addition reaction in the presence of a peroxide catalyst or in the absence of a catalyst.

The addition reaction may be carried out using a peroxide catalyst (e.g. benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, etc.) under an inert gas atmosphere.
t-Butyl peroxybenzoate, 1,1-bis(t
-butylperoxy) 3,3.5-)limethylcyclohexane, etc.) or in the absence of a catalyst, the reaction temperature is
Examples include a method in which the reaction is carried out at a temperature above the melting point of the polyolefin resin and below 300°C, preferably between 140 and 200°C, for a reaction time of 1 to 20 hours.

B) A method for thermally degrading a high melt viscosity polyolefin resin modified with an organic fluorine compound is to heat a high melt viscosity polyolefin resin modified with an organic fluorine compound in an inert gas atmosphere in the presence of a peroxide catalyst or in the absence of a catalyst. denatured by
A method of thermally degrading the obtained modified high melt viscosity polyolefin resin at a reaction temperature of 300 to 450° C. and a reaction time of 0.5 to IO hours can be mentioned.

In the present invention, in addition to the modified polyolefin resin modified with an organic fluorine compound, polyolefin resins that may be used as necessary include commonly used polyolefin resins, such as the aforementioned low melt viscosity polyolefin resins l) to 4).
, as well as Japanese Patent Application No. 1-199755 and Japanese Patent Application No. 1-308.
445, the polyolefin resins described in the specifications of Japanese Patent Application No. 1-323507, and Japanese Patent Application No. 1-10570.
Examples include polyolefin resins modified with organic silane compounds as described in each specification of No. 2.

The ratio of the modified polyolefin resin modified with an organic fluorine compound and the polyolefin resin can be varied over a wide range, and can be, for example, in a weight ratio of 1:0 to 1:9, preferably 1:0 to 1:1. can.

The melt viscosity of the mold release agent of the present invention at 180°C is 100
It is 0 cps or less, preferably 500 cps or less.

If the melt viscosity at IEiO° C. exceeds 1000 cps, the hot offset temperature will be insufficient when used as an electrophotographic toner. The melt viscosity of the mold release agent at 160° C. can be measured using a Brookfield rotational viscometer. Conditions other than measurement temperature are JIS-K1557.
-1970. An oil bath with a temperature regulator can be used to adjust the temperature of the measurement sample.

The durometer hardness of the mold release agent of the present invention is 30 or more, preferably 40 or more. If the durometer hardness is less than 30, the toner will have insufficient fluidity when used as an electrophotographic toner. Durometer hardness is determined according to ASTM D-2240.

The release agent for electrophotographic toner of the present invention can be made into an electrophotographic toner by containing a binder, a colorant, and various additives, etc., if necessary.

Examples of the binder include styrene resins (for example, copolymers of styrene monomers, (meth)acrylic acid ester monomers and/or other monomers), and the like.

Coloring agents include carbon, iron black, and benzidine yellow.
Examples include quinacridin, rhodamine B1, phthalonanine, and the like. As magnetic powder, ferromagnetic metal powder such as iron, cobalt, nickel, magnetite, hematite, etc.
Ferrite or the like may also be used.

Furthermore, various additives include charge control agents such as Glo/N and quaternary ammonium salts.

The release agent of the present invention is usually used as a component of electrophotographic toner.
．． 5 to 30% by weight, preferably 1 to 5% by weight, binder usually 45 to 95% by weight, preferably 70 to 90% by weight, colorant usually 3 to 50% by weight, etc.

The release agent of the present invention may be added during toner production or may be mixed in advance with the binder. Further, during binder polymerization, it may be added to the system together with other components.

The production of toner for electrophotography is as follows: l) After dry blending the toner components, the toner components are melt-kneaded, then coarsely pulverized, and finally pulverized using a jet pulverizer, and further classified to form a fine powder with a particle size of usually 2 to 20 μm. 2) It can also be obtained by suspension polymerizing the monomer of the binder component in the presence of other toner components to obtain a fine powder with a particle size of usually 2 to 20 μm. It is not limited.

The electrophotographic toner is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, etc., if necessary, and used as a developer for electrostatic latent images. Furthermore, hydrophobic colloidal silica fine powder can also be used to improve the fluidity of the powder.

The electrophotographic toner is heated by a heat-fixing heat roll section of a copying machine, such as a heat-fixing type copying machine or a printer, so that it is fixed on a support (paper, polyester film, etc.) and used as a recording material.

[Examples] The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

In the examples, all parts represent parts by weight.

Example 1 A blend of 1000 parts of high melt viscosity polypropylene, 20 parts of Par7 fluorohexylethyl methacrylate, and 1 part of di-t-butyl peroxide was passed through a twin screw extruder with a barrel temperature of 120°C to produce modified high melt viscosity polypropylene. I got it. This modified high melt viscosity polypropylene resin 100
0 part was passed through a tubular reactor heated to 360°C for thermal degradation for 30 minutes to obtain a modified polyolefin resin. This is used as the mold release agent of the present invention. This mold release agent had a melt viscosity of 200 CI) Ss and a durometer hardness of 60 at 160°C.

Example 2 1000 parts of high melt viscosity polypropylene was passed through a tubular reactor heated to 360° C. and thermally degraded for 30 minutes to obtain low melt viscosity polypropylene. 1,000 parts of this low melt viscosity polypropylene was placed in a reactor purged with nitrogen.
Perfluorohexylethyl methacrylate 2
0 parts and 5 parts of di-t-butyl peroxide were added dropwise over a period of 4 hours, and the mixture was allowed to react for an additional 1 hour, and then the pressure was reduced to obtain a modified polyolefin resin. This is used as the mold release agent of the present invention. This mold release agent had a melt viscosity of GOcps and a durometer hardness of 80 at 160°C.

Comparative Example 1 Example! The modified high melt viscosity polypropylene resin was thermally degraded at 345 to 350°C for 50 minutes while continuously passing through a tube equipped with a static mixer.
A modified polyolefin resin having a melt viscosity of 1500 cps at 0°C and a durometer hardness of 65 was obtained. This is used as a comparative mold release agent.

Production Example 1 660 parts of styrene and 340 parts of butyl acrylate were thermally polymerized at 130 to 180°C without using a solvent or a polymerization initiator to obtain a binder. The binder Tg is 53℃,
Number average molecular weight is 11,000, weight average molecular weight is 7,000
It was 0. The molecular weight was measured by the PC method. The molecular weight of the binder was measured by the GPC method under the following conditions.

Equipment: Toyo Soda type 11Lc802A column:
TSK get GMH62 measurement temperature: 40℃ Sample solution: 0.5wt% THF solution solution injection amount =
200 μl Detection device: Refractive index detector Usage Example 1 Using the release agent of Example 1 and the binder of Production Example 1, an electrophotographic toner was prepared by the following method, and an electrophotographic developer was also prepared.

Toner Preparation Method Binder: 87 parts Release agent of Example 1: 4 parts Carbon black
8 parts (MA-100, manufactured by Mitsubishi Chemical Industries, Ltd.) Charge control agent 1 part (Subiron Black TR [l, manufactured by Hodogaya Chemical Industries, Ltd.) The above formulation was powder blended, and then mixed with 140% by Labo Plastomill. ℃, 3 (lrpa+) for 10 minutes, and the kneaded material was finely pulverized with a jet mill PJ old 00 (manufactured by Nippon Pneumatic Co., Ltd.).The finely pulverized material was divided into 2 microns using a powder air classifier MSD (manufactured by Nippon Pneumatic Co., Ltd.). The following fine powder was cut.

A toner was obtained by uniformly mixing 3 parts of Aerosil R972 (Nippon Aerosil) with 1000 parts of the obtained powder.

Method for Preparing Developer 25 parts of the above toner was mixed with 1000 parts of carrier iron powder for electrophotography (F-100 manufactured by Nippon Tetsuko Co., Ltd.) to obtain a developer for electrophotography.

Use Example 2 An electrophotographic developer was obtained in the same manner except that the mold release agent of Example 1 was replaced with the mold release agent of Example 2.

Comparative Use Examples 1 to 2 The mold release agent of Example I was modified with the mold release agent of Comparative Example 1 and the low melt viscosity polypropylene of Example 2 which was not modified with the organic fluorine compound (melt viscosity GOcps at 160°C, durometer hardness) Comparative electrophotographic developers (+) to (2) were obtained in the same manner except that Example 55) was used.

The evaluation results for each developer are shown in Table -■.

Table-1 Evaluation of developer 7 7 7---7---
1 Developer Release agent Fluidity Resistance *y to i Usage example Fluidity 1−−−−+ −−−−+ −−−+ −−−@Example 1 1E E 2 2E E To−−−−− −+ −−−+ −−−H Comparison Comparative Example 1 1E P 2a P G L−−1 Engineering−−−Engineering−−−Engineering−−−” a: Low melt viscosity polypropylene Note) Fluidity Honkawa Micron Co., Ltd. The fluidity index was measured and evaluated using a manufactured powder tester.

E　Liquidity index 80 or more G. Liquidity index: 70 or more and less than 80 P Liquidity index less than 70 Hot offset resistance Using a commercially available heat-fixing copier, Heat that causes hot offset The evaluation was based on the temperature of the roll.

It was confirmed that the electrophotographic toner containing the release agent of the present invention was excellent not only in toner fluidity but also in hot offset resistance.

[Effect of the invention]

Claims (1)

[Claims] 1. A modified polyolefin resin modified with an organic fluorine compound, or composed of this and a polyolefin resin, with a fluorine atom content of 0.001 to 0.001 based on the weight of the mold release agent.
5%, and the melt viscosity at 160°C is 1000 cp.
s or less, and a durometer hardness of 30 or more.