JP2011048315A - Wax for toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wax for toner, capable of achieving low temperature fixing, suppressing contamination inside a copying machine or the like caused by vapor of the wax, and giving a favorable fixed image. <P>SOLUTION: The wax as a release agent to be compounded in toner is extracted from sunflower seeds. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wax as a toner release agent.

  Conventionally, in the toner for copying machines and printers, there has been a demand for speeding up and energy saving of copying machines. In order to cope with this, development of a toner excellent in low-temperature fixability is underway. In order to achieve low-temperature fixing, it is necessary to use a toner having a low melting point as a toner release agent wax, and a toner using a low melting point wax has been proposed (see Patent Document 1).

  However, in copiers using toners using these low melting point waxes, when continuous printing is performed, optical components in the copier are contaminated by wax vapor, causing image defects. Yes.

  In general, paraffin wax having a sharp carbon number distribution and a smaller average carbon number is used as a release agent wax having excellent low-temperature fixability. Although these boiling points are sufficiently high, volatilization occurs when the thermal motion of the wax molecules overcomes the intermolecular force at the surface of the liquid surface in a heated and melted state. Volatility is affected by the vapor pressure and viscosity of the wax.

  In order to suppress the volatilization of the paraffin wax, it is effective to increase the molecular weight, but at the same time, the melting point is increased, resulting in the reverse of the low-temperature fixability. Moreover, although the volatility can be reduced to some extent by removing low-boiling components by distillation purification, the effect is small for the cut rate, which is not a satisfactory level.

Also, it has been proposed to use microcrystalline wax as a countermeasure against wax vapor (see Patent Document 2). However, in order to obtain a high effect for suppressing wax vapor, it is necessary to use highly purified microcrystalline wax. In that case, the compatibility with the resin is poor, which adversely affects the powder fluidity and storage stability of the toner, and there is a risk of image defects.
JP 11-327193 A JP 2007-206178 A

  The present invention has been made in view of the circumstances as described above, achieves low-temperature fixing, can further suppress internal contamination of a copying machine or the like by wax vapor, and can obtain a good fixed image. An object is to provide a toner wax that can be produced.

The inventors of this application have made various studies on a low-volatility toner wax that generates less wax vapor in view of the above-described situation regarding the wax for a toner release agent.
As a result, the present inventors have found that the wax component collected from sunflower seeds has little generation of wax vapor and has good compatibility with polar resins, thereby completing the present invention.

  According to the wax of the present invention, low-temperature fixing is achieved, toner preservability and powder flowability are good, and internal contamination of a copying machine or the like by wax vapor can be suppressed, and a good fixed image Can be obtained.

  Hereinafter, the present invention will be described in detail.

  First, the wax of the present invention will be described.

  The toner wax of the present invention is a wax component collected from sunflower seeds.

  The method for collecting wax from sunflower seeds is not particularly limited, and can be obtained by wintering of sunflower oil collected by expression of seeds or solvent extraction, or by solvent washing of the seed shell surface.

  The toner wax of the present invention may be subjected to a purification treatment such as solvent extraction, distillation, adsorption, hydrogenation, and filtration as necessary.

  The wax for toner of the present invention is a linear monoester. The ester wax having a branch has a high viscosity at the time of melting, and movement inside the resin is hindered.

  The toner wax of the present invention has a linear monoester content of 48 or more carbon atoms of 45% or more. The boiling point of linear monoesters having 48 or more carbon atoms is high and does not volatilize below 250 ° C. When an ester having 48 or less carbon atoms is a main component, there is a risk of wax vapor generation, which is not preferable.

  The wax for toner of the present invention has an acid value of 7 [mgKOH / g] or less. Since impurities such as carboxylic acids other than esters cause wax vapor, it is desirable that the acid value be as low as possible.

  In the endothermic curve measured by DSC of the wax for toner of the present invention, the peak top temperature of the maximum endothermic peak is 65 to 85 ° C., but when it is 65 ° C. or less, thermal aggregation tends to occur when blended in the toner, There is a problem with storage stability. On the other hand, if it is 85 ° C. or higher, the fixing temperature becomes high, which is not preferable because it goes against the purpose of low-temperature fixing.

  The wax of the present invention may be used alone as a toner wax, or may be used in combination with other waxes as a toner wax. In addition, when added to paraffin wax, a dramatic effect cannot be expected, but since volatile components can be relatively reduced, they can be used together for the purpose of reducing the volatility of paraffin wax.

  As the toner fixing resin used together with the toner wax produced according to the present invention, those generally used as toner fixing resins can be used. Specific examples thereof include styrene / acrylic resins, polyester resins, Examples thereof include polyolefin resins having a cyclic structure.

  Specific examples of styrene / acrylic resins include styrene / acrylic acid copolymers, styrene / diethylamino / ethyl methacrylate copolymers, styrene / butadiene / acrylic acid ester copolymers, styrene / methyl methacrylate copolymers, and styrene. Examples thereof include butyl methacrylate copolymer, styrene / butyl methacrylate / maleic anhydride copolymer, and styrene / butyl methacrylate / acrylic acid copolymer.

  The following can be mentioned as a copolymerization monomer of a polyester resin. Specific examples of the acid component include malonic acid, succinic acid, glutaric acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydroterephthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, dimethyltetrahydrophthalic acid, naphthalenetetra Examples include carboxylic acid, trimellitic acid, and pyromellitic acid. These may be used alone or in combination of two or more. Specific examples of the alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, isopentyl glycol, hydrogenated bisphenol A, 1,3-butanediol, 1,4-butanediol, Examples include trimethylolpropane and pentaerythritol. These may be used alone or in combination of two or more.

  Specific examples of the polyolefin resin having a cyclic structure include a copolymer of an alpha olefin such as ethylene, propylene and butylene and an alicyclic compound having a double bond such as cyclohexene and norbornene.

  The method for producing the toner using the wax produced according to the present invention is not particularly limited. For example, the pulverization method by melt kneading, suspension polymerization method, emulsion polymerization method, miniemulsion polymerization aggregation method, polyester chain elongation And other known methods.

  The toner using the wax produced according to the present invention may be either a monochrome toner or a color toner, and contains a colorant depending on the use of the toner. As the colorant, commonly used pigments and dyes can be used.

  The toner fixing method using the wax produced according to the present invention is not particularly limited, and examples thereof include an oven-type fixing method, a flash-type fixing method, a heating / pressure fixing method, and other known methods. Can be mentioned.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.

  Measurement methods and preparation methods in the following Examples and Comparative Examples are as follows.

[Ester content with 48 or more carbon atoms]
The measurement was performed by a gas chromatograph apparatus (6890N manufactured by Agilent Technologies) equipped with a capillary column. Calculated as a percentage of the peak area of a linear monoester having 48 or more carbon atoms with respect to the sum of peak areas on the gas chromatogram chart.

[Melting temperature]
The melting temperature was measured according to JIS K 7121 by DSC measurement (DSC 6220, manufactured by Seiko Denshi Kogyo).

[Low melting point component content]
The total amount of heat of fusion is measured by DSC measurement (DSC 6220, manufactured by Seiko Denshi Kogyo) in accordance with JIS K7122. The percentage of the heat of fusion between 0 to 50 ° C. with respect to the total heat of fusion is defined as the low melting point component content.

[Weight loss rate]
By weight loss analysis by heating (TG / DTA 2020 manufactured by Seiko Denshi Kogyo Co., Ltd.), the weight loss rate when holding for 1 hour at a setting of 300 ° C. was measured. Since the actual sample temperature was 264 ° C., the weight loss rate was 264 ° C.

[Resin kneaded product]
A sample was obtained by kneading 100 parts by mass of polyester resin and 5 parts by mass of wax with a small biaxial kneader (HAAKE minilab) at 100 ° C. and 100 rpm for 30 minutes.

[Dispersed particle size]
The resin kneaded product was observed with a scanning electron microscope SEM (JEOL JSM5200), and the average particle size of the dispersed particles was calculated.

Example 1
Evaluation was carried out using an Asian SUNLOWER WAX.

(Example 2)
Evaluation was carried out using SUNLOWER WAX from Europe.

(Example 3)
Asian sunflower wax was treated with white clay to remove the resinous component, and then the low boiling point component was removed with a centrifugal molecular distillation apparatus. The yield was 30%.

(Comparative Example 1)
Evaluation was performed on paraffin wax HNP-9 (manufactured by Nippon Seiwa), which is generally used as a wax for toner.

(Comparative Example 2)
As described in Patent Document 2, microcrystalline wax generates less wax vapor. Evaluation was performed on Hi-Mic-1090 (manufactured by Nippon Seiwa), which is used as a microcrystalline wax in toner applications.

(Comparative Example 3)
Evaluation of commercially available behenyl behenate, Unistar M2222SL (manufactured by NOF Corporation) was carried out.

The measurement results of the ester content of the wax having 48 or more carbon atoms, the acid value, the melting temperature, the low melting point component content, the weight loss starting temperature, 264 ° C. weight loss rate, and the dispersed particle size of the resin kneaded material in Examples and Comparative Examples are shown. It is shown in 1.

  In the measurement of the weight loss rate, 264 ° C. was not realistic because the measurement temperature was too high, but it was measured for the purpose of confirming the effect when the temperature fluctuated and clearly showing the difference between the waxes. The result of the heat loss analysis with the wax alone has a high correlation between the measurements at 216 ° C. and 264 ° C., and it can be said that the influence of the measurement temperature is small.

  HNP-9 (normal paraffin) of Comparative Example 1 has high performance as a release agent for toner due to sharp melting behavior. On the other hand, there is a problem that the heating loss rate is high, there is an adverse effect due to wax vapor, and the compatibility with the resin is low.

  Hi-Mic-1090 (microcrystalline wax) of Comparative Example 2 has a sharp melting behavior, a low weight loss rate and a low effect of wax vapor, but a low compatibility with the resin. There is.

  The synthetic ester of Comparative Example 3 is an ester wax having 44 carbon atoms as the main component, and the heating loss rate is high.

  In Examples 1 and 2, SUNFLOWER WAX has a low content of low melting point components, and when used as a wax for toner, powder flowability and storage stability are good. In addition, the heat loss rate is low, and wax vapor is unlikely to occur.

  The molecular distillation-treated product of SUNLOWER WAX in Example 3 has a linear monoester content of 48 or more carbon atoms of 90% or more, and the heating loss rate is considerably low. It is confirmed that the higher the content of the linear monoester having 48 or more carbon atoms, the lower the heating loss rate and the less likely wax vapor is generated.

  SUNLOWER WAX is a polar wax and has high compatibility with a resin, but it is not completely compatible and is finely dispersed in toner particles, and therefore has good performance as a release agent wax for toner.

  As is clear from the above results, SUNLOWER WAX has various characteristics required for toner wax, such as moderate melting point, sharp melt, low low melting point, hard, low volatility, and moderate compatibility with resin. It is confirmed that it satisfies.

  That is, it has high performance as a toner release agent and can suppress the occurrence of vapor in the copying machine, so that the problem that optical system components and the like are contaminated and image defects occur can be solved.

Claims (4)

  A wax for toner, which is a wax that is a release agent to be blended with toner, and is a wax component collected from sunflower seeds.   The toner wax according to claim 1, wherein the content of the linear monoester having 48 or more carbon atoms is 45% or more.   2. The toner wax according to claim 1, wherein the acid value is 7 [mg KOH / g] or less.   2. The wax for toner according to claim 1, wherein a peak top temperature of a maximum endothermic peak is 65 to 85 ° C. in an endothermic curve measured by DSC.