JP2015064433A - Manufacturing method of toner for film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for film that enables the manufacture of a film having sufficient negative chargeability and excellent performance.SOLUTION: A manufacturing method of a toner for film includes the steps of: melting a film grade resin having negative chargeability; mixing a film resin having lower negative chargeability than that of the film grade resin with the molten film grade resin, and melt-kneading the mixture to obtain a kneaded product; and pulverizing the kneaded product after curing, where the film resin and film grade resin used has the softening point within a range from -20°C to +20°C of the softening point of the film resin; the step of obtaining the kneaded product is performed such that the kneaded product contains the film grade resin in a proportion from 5 to 30 mass%; and the pulverizing step is performed such that the average particle diameter D50 (volume) of a pulverized product falls within a range from 9 to 50 μm.

Description

  The present invention relates to a method for producing a toner for film.

In general, the label is manufactured by the following method. First, a label sheet in which an adhesive layer is provided on one side and this adhesive layer is covered with release paper is prepared. Next, a pattern is printed on the label paper, and then the label paper is cut into an arbitrary shape.
However, this method requires a plate for printing a pattern and a blade shape such as a cutting die for cutting label paper, which is problematic in that the cost of the manufacturing apparatus is high. Thus, a method has been proposed in which toner is developed into an arbitrary shape by an electrophotographic method, and then heated and fixed to produce a label (see Patent Document 1).

In the electrophotographic system, a negatively chargeable toner is usually used. However, some resins that can achieve the performance required for the film are either positively charged or weakly negatively charged.
In addition, although the method of mixing other resin with such resin is known, they are described about the solution of mechanical problems, such as intensity | strength and impact resistance (for example, patent document 2). 3) Nothing intended for use as a film electrophotographic toner including improved chargeability is disclosed.

JP 2007-283745 A JP 2009-108292 A JP 2009-108276 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a toner for a film that has a sufficient negative chargeability and that can produce a film having excellent performance.

  According to one aspect of the present invention, the step of melting the negatively chargeable film grade resin, the film resin having a lower negative chargeability compared to the film grade resin, and the melted film grade resin are mixed, This includes a step of melt kneading to obtain a kneaded product, and a step of pulverizing the cured kneaded product, and the film grade resin has a softening point of −20 ° C. to + 20 ° C. The step of obtaining the kneaded product using the one in the range of ° C. is performed so that the kneaded product contains the film grade resin in a proportion of 5 to 30% by mass, and the step of pulverizing is performed by There is provided a method for producing a toner for a film, wherein the average particle diameter D50 (volume) is in the range of 9 to 50 μm.

FIG. 2 is a plan view illustrating an example of a printer used for printing film toner according to an embodiment. The figure which shows the image sample printed using the toner for films concerning an Example and a comparative example.

Hereinafter, embodiments of the present invention will be described.
First, a film toner produced by the method according to an embodiment of the present invention will be described.
This film toner contains a film resin as a main component of the binder resin, a negatively chargeable film grade resin, and optionally an internal additive and / or an external additive.

The film resin is a particle having positive chargeability or negative chargeability. When the film resin has a negative chargeability, it has a lower negative chargeability than the film grade resin.
The film resin is usually superior in performance as a binder resin as compared with a film grade resin.

The film resin may or may not have biodegradability. When the film resin has biodegradability, even if the label made using this film resin is discarded in the soil, it is quickly decomposed compared to the case where it does not have biodegradability. .
The softening point of the film resin is, for example, 95 to 145 ° C.

  Examples of the film resin include polybutylene succinate resin, polylactic acid resin, low density polyethylene resin, linear low density polyethylene resin, ethylene vinyl acetate polymer, ethylene methacrylic acid copolymer, ionomer resin, acrylonitrile butadiene styrene copolymer. It is possible to use one or more resins selected from the group consisting of polymers, cyclic polyolefin copolymers, polyester sulfone resins, ethylene ethyl acrylate resins, polyethylene terephthalate resins, polypropylene resins, polystyrene resins, acetalized polyvinyl alcohol resins and derivatives thereof. it can.

  The film grade resin is a film grade resin having negative chargeability. In the present specification, the film grade refers to the property that the film can be easily formed by methods such as melt extrusion molding, calendering, stretching, etc., the embrittlement temperature is in the negative range, and elasticity is obtained at room temperature.

  The softening point of the film grade resin is in the range of −20 ° C. to + 20 ° C. with respect to the softening point of the film resin. When the softening point difference is larger than 20 ° C., the charge amount of the film toner is insufficient, and there is a possibility that a sufficient development amount cannot be obtained. This is presumably because the film resin and the film grade resin are separated after kneading, and the surface area where the positively chargeable film resin is exposed increases.

The resin flight rate of the film grade resin is typically 60% or more. A method for measuring the resin flight rate will be described later.
Examples of the film grade resin include low density polyethylene resin, linear low density polyethylene resin, ethylene vinyl acetate polymer, ethylene methacrylic acid copolymer, ionomer resin, acrylonitrile butadiene styrene copolymer, cyclic polyolefin copolymer, polyester sulfone. One or more resins selected from the group consisting of resin, ethylene ethyl acrylate resin, polyethylene terephthalate resin, polypropylene resin, polystyrene resin, acetalized polyvinyl alcohol resin and derivatives thereof can be used. The ratio is, for example, 60% by mass or more with respect to the total mass (hereinafter, toner mass) of the film resin, the film grade resin, and the additive.

The ratio of the film grade resin contained in the film toner is in the range of 5 to 30% by mass with respect to the toner mass. More preferably, it is in the range of 10 to 25% by mass.
When the ratio of the film grade resin is small, the negative chargeability of the toner is insufficient and a sufficient development amount cannot be obtained. On the other hand, when the ratio of the film grade resin is large, the pulverization property is lowered and the storage property as the toner is also lowered, so that it cannot be handled as the toner.

  The average particle diameter D50 (volume) of the film toner is typically 9 to 50 μm, preferably 15 to 40 μm. When the average particle diameter D50 is small, it is difficult to obtain a film having a sufficient thickness. When the average particle diameter D50 is large, the chargeability is insufficient, so that a sufficient development amount may not be obtained.

  In the film toner described above, it is presumed that the film resin and the film grade resin have a core-shell structure. That is, when the film resin is regarded as a spherical shape, it is assumed that most of the outermost surface of the film resin has a structure in which the film grade resin is coated.

  Since it has such a structure, it becomes possible to greatly reduce the influence of the charging property of the film resin, and since the film grade resin is negatively charged, the particles containing these resins behave as negatively charged. . That is, a film toner having sufficient negative chargeability can be obtained while taking advantage of the excellent performance of the film resin as the binder resin.

Next, the manufacturing method of the film toner comprised as mentioned above is demonstrated.
First, the film grade resin is put into a kneader, the temperature of the kneader is set to a temperature (softening point) at which the film grade resin melts or higher, and the film grade resin is melted. This set temperature is, for example, 100 to 180 ° C., and typically 120 to 160 ° C.

Next, a film resin synthesized by a conventionally known method or a commercially available film resin and, if necessary, an internal additive are mixed, and this mixture is kneaded containing a film grade resin that has already been melted. Put in machine and knead.
The temperature at the time of kneading (kneading temperature) is, for example, not less than the above set temperature. Typically, the difference between the kneading temperature and the set temperature is in the range of 10 ° C to 30 ° C.

The kneading time is, for example, 5 to 30 minutes. However, when the softening point of the film resin is higher than the softening point of the film grade resin and the kneading temperature, the kneading may be performed for a longer time.
Thereafter, the kneaded product is cooled until cured, and pulverized with a mill or the like to obtain a toner. In addition, resin used for films generally has a low embrittlement temperature and a glass transition temperature. Therefore, it is preferable to use freeze pulverization for this pulverization.

A film toner is obtained by adding, for example, hydrophobic silica as an external additive to the obtained toner.
Next, an example of a printer that prints the film toner described above on a film pressure-sensitive adhesive sheet will be described with reference to the drawings.
The printer 10 shown in FIG. 1 is a modification of a commercially available “N6000” manufactured by Casio Computer Co., Ltd. In the printer 10, a TS 12, a developing roll 13, a photoreceptor 14, a transfer unit 15, and a fixing unit 16 are disposed around the print belt 11. A cassette 17 for storing the adhesive sheet for film is arranged at the bottom of the printer, and a paper discharge unit 18 for discharging printed paper is arranged at the top. In TS12, film toner is stored.

The printer 10 shown in FIG. 1 operates as follows.
First, an adhesive sheet for film is supplied from the cassette 17 and passes through each part along the paper path C. On the sheet that has reached the transfer unit 15, an image made of toner developed on the photosensitive member 14 is transferred. The developed image is obtained by developing the film toner supplied from the TS 12 onto the photoreceptor 14 by the developing roll 13.

  The sheet on which the image (toner) transferred in the transfer unit 15 is placed is further conveyed along the paper path C to the fixing unit, where a fixing process is performed, and the film toner is fixed. Thereafter, the sheet is discharged to the paper discharge unit 18 and the operation is completed.

Examples Hereinafter, examples of the present invention and comparative examples will be described.
For measuring the particle size, “LA920” manufactured by Horiba, Ltd., which is a laser diffraction / scattering particle size distribution measuring device, was used.
Example 1
First, polybutylene succinate (PBS) used as a toner film resin was synthesized as follows.

  Specifically, 0.4 parts by mass of malic acid and 1 part by mass of germanium dioxide were dissolved in 100 parts by mass of an 88% by mass lactic acid aqueous solution, and 5.4 parts by mass of the aqueous solution was added to 100% succinic acid. It added with respect to the mass part and 89 mass parts of 1, 4- butanediol. After making the inside of a reaction system nitrogen atmosphere, it was made to react at 220 degreeC for 1 hour, and then it was pressure-reduced to 70 Pa over 1.5 hours, heating up to 230 degreeC. Thereafter, the reaction was further continued for 2 hours to proceed the polymerization, and PBS having a softening point of 125 ° C. was obtained. A method for measuring the softening point will be described later.

  Subsequently, as a film grade resin, “Sumikasen FV402” manufactured by Sumitomo Chemical Co., Ltd. was freeze-ground under liquid nitrogen using a “Linrex mill” manufactured by Hosokawa Micron to obtain a pulverized product of 50 μm (volume D50). Moreover, the flight rate and softening point of this pulverized product were measured. A method for measuring the flight rate will be described later.

10 parts by mass of the pulverized “Sumikasen FV402” was put into a batch kneader, the temperature was set at 160 ° C., and the resin was melted for 1 hour.
Next, 85.5 parts by mass of the synthesized PBS, 2 parts by mass of “Bonfast 2B” manufactured by Sumitomo Chemical Co., Ltd., and 2.5 parts by mass of “Carnava WAX No. 1 powder” imported from Kato Yoko Co., Ltd. The mixture was put into a “Henschel mixer” manufactured and mixed, and this mixture was put into a batch kneader which had been heated, and melt kneaded at a kneading temperature of 160 ° C. for 15 minutes to obtain a kneaded product.

This kneaded product was freeze-pulverized under liquid nitrogen using a “Linrex mill” manufactured by Hosokawa Micron to obtain a pulverized product of 9 μm (volume D50).
Further, 100 parts by mass of the pulverized product and 1 part by mass of hydrophobic silica “R972” manufactured by Nippon Aerosil Co., Ltd. were mixed with a Henschel mixer to obtain a film toner A1.

The obtained film toner A1 was filled in the TS 12 of the printer 10 described above, and printing was performed. At this time, the printing pattern was a solid image shown in FIG.
(Example 2)
A film toner A2 was produced in the same manner as in Example 1 except that “Sumikasen F208-3” manufactured by Sumitomo Chemical was used as the film grade resin instead of “Sumikasen FV402” manufactured by Sumitomo Chemical.

(Example 3)
A film toner A3 was prepared in the same manner as in Example 1 except that “Sumikasen FV402” manufactured by Sumitomo Chemical Co., Ltd. was used as the film grade resin instead of “Ultzex 1020L” manufactured by prime polymer.
Example 4
Film toner A4 was produced in the same manner as in Example 1 except that “Wintech WFX4” manufactured by Nippon Polypro was used as the film grade resin instead of “Sumikasen FV402” manufactured by Sumitomo Chemical Co., Ltd.

(Example 5)
A film toner A5 was produced in the same manner as in Example 1 except that “F522N” made by Ube Maruzen polyethylene was used instead of “Sumikasen FV402” made by Sumitomo Chemical as the film grade resin.
(Example 6)
A film toner A6 was produced in the same manner as in Example 1 except that “C470” made by Ube Maruzen polyethylene was used as the film grade resin instead of “Sumikasen FV402” made by Sumitomo Chemical.

(Example 7)
A film toner A7 was produced in the same manner as in Example 1 except that “B228” made by Ube Maruzen polyethylene was used as the film grade resin instead of “Sumikasen FV402” made by Sumitomo Chemical Co., Ltd.
(Example 8)
A film toner A8 was produced in the same manner as in Example 1 except that “F222NH” made by Ube Maruzen polyethylene was used instead of “Sumikasen FV402” made by Sumitomo Chemical as the film grade resin.

Example 9
Film toner A9 was produced in the same manner as in Example 1 except that PBS as the film resin was 90.5 parts by mass and “Sumikasen FV402” as the film grade resin was 5 parts by mass.
(Example 10)
A film toner A10 was produced in the same manner as in Example 1 except that PBS as the film resin was 65.5 parts by mass and “Sumikasen FV402” as the film grade resin was 30 parts by mass.

(Example 11)
Film toner A11 was produced in the same manner as in Example 1 except that the average particle diameter D50 (volume) of the pulverized product before external addition was 50 μm.
(Comparative Example 1)
A film toner B1 was prepared in the same manner as in Example 1 except that 95.5 parts by mass of PBS as a film resin and “Sumikasen FV402” as a film grade resin were not used.

(Comparative Example 2)
A film toner B2 was produced in the same manner as in Example 1 except that “Sumikasen F412-1” manufactured by Sumitomo Chemical Co., Ltd. was used instead of “Sumikasen FV402” as the film grade resin, and the kneading temperature was 170 ° C. .
(Comparative Example 3)
A film toner B3 was prepared in the same manner as in Comparative Example 2, except that “Newcon NLB340G” manufactured by Nippon Polypro Co., Ltd. was used instead of “Sumikasen FV402” as the film grade resin.

(Comparative Example 4)
A film toner B4 was prepared in the same manner as in Comparative Example 2 except that “WFX6” manufactured by Nippon Polypro Co., Ltd. was used instead of “Sumikasen FV402” as the film grade resin.
(Comparative Example 5)
A film toner B5 was produced in the same manner as in Comparative Example 2, except that “Wellnex RFG4VA” manufactured by Nippon Polypro Co., Ltd. was used instead of “Sumikasen FV402” as the film grade resin.

(Comparative Example 6)
Film toner B6 was produced in the same manner as in Comparative Example 2, except that “Prime Polypro F329RA” manufactured by Prime Polymer Co., Ltd. was used instead of “Sumikasen FV402” as the film grade resin.
(Comparative Example 7)
Film toner B7 was prepared in the same manner as in Comparative Example 2, except that “Prime TPOT310E” manufactured by Prime Polymer Co., Ltd. was used in place of “Sumikasen FV402” as the film grade resin.

(Comparative Example 8)
A film toner B8 was prepared in the same manner as in Comparative Example 2 except that “Hi-Zex 8000F” manufactured by Prime Polymer Co., Ltd. was used instead of “Sumikasen FV402” as the film-grade resin.
(Comparative Example 9)
A film toner B9 was prepared in the same manner as in Example 1 except that PBS as the film resin was 67.5 parts by mass and “Sumikasen FV402” as the film grade resin was 31 parts by mass.

(Comparative Example 10)
A film toner B10 was produced in the same manner as in Example 1 except that PBS as the film resin was 91.5 parts by mass and “Sumikasen FV402” as the film grade resin was 4 parts by mass.
(Comparative Example 11)
Film toner B11 was produced in the same manner as in Example 1 except that the average particle diameter D50 (volume) of the pulverized product before external addition was 60 μm.

(Comparative Example 12)
Film toner B12 was produced in the same manner as in Example 1 except that “Sumikasen FV402” as a film grade resin was not melted in advance.
The film toner obtained in the above examples and comparative examples was filled in TS12 of the printer shown in FIG. 1, and normal printing was performed. That is, in response to a print request, the image developed on the photoconductor 14 is transferred to a sheet by the transfer unit 15 and fixed by the fixing unit 16. At this time, the printing pattern was a solid image shown in FIG. As the paper, an adhesive sheet for film manufactured by Lintec Corporation was used.

About each example, it measured and evaluated with the following method.
1. Resin softening point difference For each film toner, the softening point between the film resin and the film grade resin used for the production was measured, and the difference between the softening points was calculated (softening point of the film resin−softening point of the film grade resin). The softening point was measured using “CFT-500D” manufactured by Shimadzu Corporation, the sample was 1 g, the temperature elevation temperature was 6 ° C./min, the load was 20 kg, the nozzle was 1 mm in diameter and 1 mm in length. The temperature at which half of the sample flowed out by the two methods was taken as the softening point.
○: Within 20 ° C. Δ: 20 ° C. or higher and lower than 40 ° C. ×: 40 ° C. or higher

2. Film Grade Resin Flight Rate The flight rate was measured for the film grade resin used in the production of each film toner. For the flight rate measurement, an electric field flight type charge amount measuring device (manufactured by DIT) was used, and the sample was conditioned at an ambient temperature of 25 ° C. and a humidity of 50% for 12 hours, and then the flight at -1 kv pressurization. The rate was measured. At this time, the measurement time was 60 seconds, the rotation speed was 250 rpm, and a carrier having a particle size of 35 μm manufactured by Powdertech Co., Ltd. was used.
○: 60% or more / -1 kv
Δ: 40% to less than 60% / − 1 kv
X: 40% or less / -1 kv

3. Toner charge amount In order to measure the toner charge amount on the developing roll 13 during printing of each film toner, a solid image was printed on the adhesive sheet for film. The printer was turned off at the moment when the center of the sheet passed the transfer unit 15. In this state, the TS 12 was removed, and the charge amount of the toner on the developing roll 13 before being supplied to the photoreceptor 14 was measured.

The charge amount was measured using “MODEL210HS-3” manufactured by TREK, and the toner on a certain area was sucked to calculate the charge amount based on the charge and the area.
○: −10 μC / g or more Δ: 0 μC / g or more and less than −10 μC / g ×: less than 0 μC / g

4). Loading amount (mass)
About the image sample of each example, the loading amount (mass) per unit area was measured from the mass difference of the sheet | seat before and behind printing.
○: 40 g / m ² or more Δ: 20 g / m ² or more and less than 40 g / m ² ×: less than 20 g / m ²

5. Loading amount (visually)
About the image sample of each example, the state of the printed image was observed visually.
○: It is placed evenly and uniformly.
Δ: A little uneven and slightly uneven.
X: Not uniform and uneven.
The above results are summarized in Tables 1 to 4.

  The difference in softening point between the film resin and the film grade resin is within 20 ° C., the film grade resin is contained in an amount of 5 to 30% by mass with respect to the toner mass, and the average particle diameter D50 (volume) of the film toner is in the range of 9 to 50 μm. Some film toners had good results with respect to toner charge amount, applied amount (mass) and applied amount (visually) (Examples 1 to 11).

On the other hand, in Comparative Example 1 in which no film grade resin was mixed, and in Comparative Examples 2 to 8 in which the difference in softening point was not within 20 ° C., the performance with respect to the toner charge amount, the applied amount (mass), and the applied amount (visually) Was inferior.
Moreover, even if the softening point difference is within 20 ° C., Comparative Examples 9 and 10 in which the ratio of the film grade resin to the toner mass is out of the range of 5 to 30% by mass are the loading amount (mass) and the loading amount (visually). Did not perform satisfactorily. Further, the film toner of Comparative Example 11 in which the average particle diameter D50 (volume) of the toner is 60 μm and Comparative Example 12 in which the film grade resin is not previously melted are the toner charge amount, the applied amount (mass), and the applied amount ( The visual performance was not sufficient.

The invention described in the scope of claims at the beginning of the application will be appended.
[1]
Melting a negatively chargeable film grade resin;
A step of mixing a film resin having a lower negative chargeability compared to the film grade resin and the melted film grade resin, and melt-kneading to obtain a kneaded product;
Crushing the kneaded product after curing,
As the film grade resin, the one having a softening point in the range of −20 ° C. to + 20 ° C. with respect to the softening point of the film resin is used.
The step of obtaining the kneaded product is performed so that the kneaded product contains the film grade resin in a proportion of 5 to 30% by mass,
The pulverizing step is a method for producing a film toner, wherein the pulverized product has an average particle diameter D50 (volume) in a range of 9 to 50 μm.
[2]
The film toner according to [1], wherein the film grade resin has a resin flight rate of 60% or more.
[3]
The method for producing a toner for a film according to [1] or [2], wherein the film resin is a polybutylene succinate resin.

  DESCRIPTION OF SYMBOLS 10 ... Printer, 11 ... Print belt, 12 ... TS, 13 ... Developing roll, 14 ... Photoconductor, 15 ... Transfer part, 16 ... Fixing part, 17 ... Cassette, 18 ... Paper discharge part, 20 ... Adhesive sheet for films, 21: Solid printing, C: Paper path.

Claims (3)

Melting a negatively chargeable film grade resin;
A step of mixing a film resin having a lower negative chargeability compared to the film grade resin and the melted film grade resin, and melt-kneading to obtain a kneaded product;
Crushing the kneaded product after curing,
As the film grade resin, the one having a softening point in the range of −20 ° C. to + 20 ° C. with respect to the softening point of the film resin is used.
The step of obtaining the kneaded product is performed so that the kneaded product contains the film grade resin in a proportion of 5 to 30% by mass,
The pulverizing step is a method for producing a film toner, wherein the pulverized product has an average particle diameter D50 (volume) in a range of 9 to 50 μm.   The method for producing a toner for a film according to claim 1, wherein a resin flying rate of the film grade resin is 60% or more.   The method for producing a toner for a film according to claim 1, wherein the film resin is a polybutylene succinate resin.