JP2010260886A - Method for producing cross-linked polyester resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a cross-linked polyester resin, by which air and water contained in an unsaturated double bond-having polyester resin fed as a raw material can be removed before a reaction with a cross-linking initiator to uniformly perform the cross-linking reaction, thereby producing the cross-linked polyester resin having uniform physical properties. <P>SOLUTION: This method for producing the cross-linked polyester resin comprises sequentially performing the following processes (1) to (5) with an extruder having a raw material-feeding portion 1, a degasifying portion 2, a cross-linking initiator-feeding portion 3, and an extruding portion 4: (1) the process for feeding the unsaturated double bond-having polyester resin A from the raw material-feeding portion 1, (2) the process for melt-mixing the polyester resin A between the raw material-feeding portion 1 and the degasifying portion 2, (3) the process for degasifying the polyester resin A melted and mixed in the degasifying portion 2, (4) the process for feeding the cross-linking initiator to the degasified polyester resin A from the cross-linking initiator-feeding portion 3 to perform a cross-linking reaction, and (5) the process for extruding the cross-linked polyester resin from the extruding portion 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a method for producing a crosslinked polyester resin in which a polyester resin having an unsaturated double bond is crosslinked using an extruder.

  In recent years, the performance and quality required for synthetic resins have only increased, and it is often required to satisfy different properties and functions simultaneously. In addition, these requirements vary greatly depending on the field of industry and type of industry, and it is difficult for a single synthetic resin to cope with each.

As a solution to this problem, a polymer alloy technique using a plurality of synthetic resins is frequently used. In addition, synthetic resins having characteristic performance are manufactured by a technique called reactive processing using an extruder.
For example, as a method for producing a crosslinked polyester resin excellent in low-temperature fixability for toner, Patent Document 1 uses a twin-screw extruder to melt a mixture of a polyester resin having an unsaturated double bond and an organic peroxide. A method is described in which a cross-linking reaction is performed while kneading, and a cross-linked polyester resin is obtained in which a volatile component is removed by a devolatilizer after the cross-linking reaction.
JP-A-5-249739

  Normally, when the polyester resin having an unsaturated double bond is reacted while being melted in an extruder, the resin raw material is often in the form of a granular material such as a powder or a pellet. Air and moisture are easily mixed. In particular, oxygen in the air is known to inhibit the reaction between a polyester resin having an unsaturated double bond and a crosslinking initiator.

  In the method of Patent Document 1, since deaeration is performed after the cross-linking reaction, it is difficult to suppress the influence of oxygen and moisture during the cross-linking reaction, and the cross-linking reaction changes irregularly, resulting in cross-linking. Polyester resin properties tend to be non-uniform.

  An object of the present invention is to provide a method for producing a crosslinked polyester resin having a uniform physical property by uniformly performing a crosslinking reaction.

The gist of the present invention is a cross-linked polyester resin in which the steps (1) to (5) are sequentially performed using an extruder having a raw material supply unit 1, a deaeration unit 2, a cross-linking initiator supply unit 3, and a discharge unit 4. It is in the manufacturing method.
(1) Step of supplying polyester resin A having an unsaturated double bond from raw material supply unit 1 (2) Step of melting and mixing polyester resin A between raw material supply unit 1 and degassing unit 2 (3) Degassing Step (4) for degassing polyester resin A melt-mixed in part 2 Step (5) for supplying cross-linking initiator to degassed polyester resin A from cross-linking initiator supply unit 3 and performing cross-linking reaction Step of discharging the cross-linked polyester resin cross-linked from the discharge unit 4

  According to the present invention, a crosslinked polyester resin having uniform physical properties can be obtained. In addition, the operating state is stable and industrially advantageous.

In this invention, using the extruder which has the raw material supply part 1, the deaeration part 2, the crosslinking initiator supply part 3, and the discharge part 4, the process of (1)-(5) is performed sequentially and unsaturated double Crosslinking reaction of the polyester resin A having a bond is performed.
(1) Step of supplying polyester resin A having an unsaturated double bond from raw material supply unit 1 (2) Step of melting and mixing polyester resin A between raw material supply unit 1 and degassing unit 2 (3) Degassing Step (4) of degassing polyester resin A melt-mixed in part 2 (5) Step of supplying cross-linking initiator from cross-linking initiator supply unit 3 to degassed polyester resin A and performing cross-linking reaction (5) In the present invention, it is necessary to use an extruder having a raw material supply unit 1, a degassing unit 2, a crosslinking initiator supply unit 3, and a discharge unit 4. .

When a polyester resin having an unsaturated double bond is subjected to a crosslinking reaction using a crosslinking initiator,
If the amount of moisture in the reaction system or the amount of oxygen in the air that acts as a reaction inhibitor varies, the physical properties of the cross-linked polyester resin obtained without a uniform cross-linking reaction will vary.

In the present invention, by providing the deaeration unit 2 between the raw material supply unit 1 and the crosslinking initiator supply unit 3, the air and moisture contained in the polyester resin having an unsaturated double bond supplied as a raw material, It can be removed before the cross-linking reaction, the cross-linking reaction is uniformly performed, and a cross-linked polyester resin having uniform physical properties can be obtained.
In addition, a well-known single screw extruder, a twin screw extruder, a multi screw extruder etc. can be used for the extruder of this invention. Among these, a twin screw extruder is preferable because of its high kneading effect. If it is a twin screw extruder, the rotation direction and combination of a screw can use any of a same direction rotation type / different direction rotation type, a meshing type / non-meshing type. Among them, the same direction rotation complete meshing type is preferable because of its high internal self-cleaning property. The twin-screw extruder is basically constituted by a screw that gives rotational energy from a motor to a material while conveying the material, and a cylinder that holds the screw inside. The material used for the part in contact with the resin material of the screw or cylinder can be appropriately selected depending on the resin material. Wear-resistant materials such as nitrided steel, corrosion-resistant materials such as nickel-based alloys, and corrosion-resistant and wear-resistant materials known as HIP materials can be used.
What is necessary is just to select suitably the magnitude | size of an extruder, ie, a screw diameter and length, according to processing amount and time which reaction requires. The screw diameter is preferably about 15 mm to 200 mm. The total length of the cylinder or the length of the screw is preferably about 20 to 100 times the screw diameter.
For the cylinder, an external heater, an external jacket, an internal jacket, or the like can be used to control the temperature. As the external heater, a band heater, an aluminum cast heater, a brass cast heater, or the like can be used. In the case of an outer jacket or an inner jacket, the temperature can be controlled by flowing hot / cold water or a heating medium. There is no problem using these in combination. In order to enable finer temperature control, it is more preferable to provide these heaters and jackets for each divided section as a combination of the cylinders divided into a plurality of blocks.
The temperature of the cylinder can be appropriately set according to the polyester resin having an unsaturated double bond to be handled or the crosslinking initiator.

  Next, each step will be described.

(1) Step of supplying the polyester resin A having an unsaturated double bond from the raw material supply unit 1 In the present invention, the unsaturated double bond is a carbon-carbon double bond, which is the main chain of the polyester resin and A polyester resin having an unsaturated double bond is used in the side chain. In order to have an unsaturated double bond in the main chain and / or side chain of the polyester resin, a polycondensation reaction using a carboxylic acid compound having an unsaturated double bond and / or an alcohol compound having an unsaturated double bond And these compounds may be incorporated as a constituent component of the polyester resin.

  Examples of carboxylic acid compounds having an unsaturated double bond include, for example, fumaric acid, maleic acid, maleic anhydride, citraconic acid, itaconic acid, tetrahydrophthalic acid and ester derivatives thereof, acrylic acid, crotonic acid, methacrylic acid And ester derivatives thereof. Examples of the alcohol compound having an unsaturated double bond include 1,4-dihydroxy-2-butene.

  Among these, at least one selected from fumaric acid, maleic acid, and maleic anhydride is particularly preferable from the viewpoint of reactivity.

  Two or more polyester resins having an unsaturated double bond may be used, and a plurality of raw material supply units may be provided before deaeration in the deaeration unit 2.

(2) Step of Melting and Mixing Polyester Resin A Between Raw Material Supply Unit 1 and Degassing Unit 2 In the present invention, a melt mixing unit 6 is provided between the raw material supply unit 1 and the degassing unit 2. By melting and mixing, the temperature rises and moisture easily evaporates, and when the resin fluidizes, the gas components and moisture dissolved in the polyester resin A can be easily removed and the deaeration effect is enhanced.

(3) Step of degassing polyester resin A melt-mixed in degassing section 2 When polyester resin A that has passed through the melt-mixing section is passed through the degassing section 2, it is placed in a reduced pressure environment, and polyester The air and moisture mixed in the extruder together with the resin A are removed. By this step, the crosslinking reaction is uniformly performed, and a crosslinked polyester resin having uniform physical properties is obtained.

  The pressure of the deaeration part 2 needs to be a reduced pressure state equal to or lower than the atmospheric pressure. By reducing the pressure to less than atmospheric pressure, the air and moisture mixed in the extruder together with the polyester resin A are efficiently removed, and the reaction between the polyester resin A and the crosslinking initiator is stabilized.

In order to further enhance the stability of the reaction, the pressure in the deaeration unit 2 is preferably a pressure of −40 kPa (gauge pressure) or less. By setting the pressure of the deaeration unit 2 to a pressure of −40 kPa (gauge pressure) or less, a high reaction rate can be obtained with a smaller amount of the crosslinking initiator.
As a means for decompressing the deaeration unit 2, a known decompression means such as a vacuum pump can be used. A means for cooling the intake gas may be provided between the deaeration unit 2 and a decompression means such as a vacuum pump.

(4) Step of supplying a crosslinking initiator from the crosslinking initiator supply unit 3 to the degassed polyester resin A and performing a crosslinking reaction In the present invention, after degassing the melt-mixed polyester resin A, By supplying a crosslinking initiator and performing a crosslinking reaction of the polyester resin A, a stable crosslinking reaction is possible without being affected by oxygen or moisture in the air, and a crosslinked polyester resin having uniform physical properties can be obtained.

  The crosslinking initiator is not particularly limited, and an azo compound or an organic peroxide is used. Among them, an organic peroxide is preferable because it has high initiator efficiency and does not generate a cyanide byproduct.

  The organic peroxide is not particularly limited. For example, benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t-butylperoxy) Diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxy Hexin-3, acetyl peroxide, isobutyryl peroxide, octaninoroxide, decanolyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t-butyl peroxide Oxyisobutyrate, t-butylperoxyneodecanoate, cumylperoxyneodecanoate T-butyl peroxy 2-ethylhexanoate, t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxy Examples thereof include oxyisopropyl carbonate and t-butyl peroxyacetate.

  The method for supplying the crosslinking initiator to the extruder is not particularly limited, and the crosslinking initiator alone may be supplied, or the crosslinking initiator may be diluted with a diluent and supplied.

  The supply temperature of the crosslinking initiator is not particularly limited, but is preferably lower than the 10-hour half-life temperature of the initiator from the viewpoint of suppressing the decomposition of the crosslinking initiator.

  Further, it is preferable to dilute the crosslinking initiator with a diluent from the viewpoint of preventing local crosslinking reaction, but the diluent remains in the polyester resin for toner. In view of the above, even if it remains in the polyester resin for toner, it does not adversely affect the toner production. Therefore, when diluting with a diluent, it is preferable to use a release agent used as a toner additive as the diluent.

  Furthermore, it is preferable that the release agent does not inhibit the crosslinking reaction of unsaturated double bonds, and as such a release agent, a hydrocarbon-type release agent is preferable, for example, low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline. Examples thereof include aliphatic hydrocarbon waxes such as wax and paraffin wax, oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, and block compounds thereof.

  Among these, the melting point of the release agent is preferably 120 ° C. or less because mixing with the crosslinking initiator is easy and the low-temperature fixability of the toner tends to be further improved. As the mold release agent having a melting point of 120 ° C. or less, paraffin wax is most preferable, and HNP series manufactured by Nippon Seiki Co., Ltd .: for example, HNP-3 (melting point 64 ° C.), HNP-5 (melting point 62 ° C.), HNP-9, 10 (Melting point 75 ° C.), HNP-11 (melting point 68 ° C.), HNP-12 (melting point 67 ° C.), HNP-51 (melting point 77 ° C.), SP series: SP-0165 (melting point 74 ° C.), SP-0160, for example (Melting point 71 ° C.), SP-0145 (melting point 62 ° C.), HNP-3 (melting point 64 ° C.), FT series: FT-0070 (melting point 72 ° C.), FT-0165 (melting point 73 ° C.) and the like.

  A known supply method can be used to supply the crosslinking initiator, and the method is not limited. In the present invention, it is preferable in terms of quality to control the ratio of the polyester resin having an unsaturated double bond and the crosslinking initiator, and it is preferable to use a metering pump for supplying the crosslinking initiator.

  Moreover, a forward feed screw, a kneading disk, a reverse feed screw, or the like can be appropriately combined with the screw of the crosslinking reaction section 7.

  Furthermore, in the present invention, in addition to the polyester resin and the crosslinking initiator, coloring agents such as pigments, inorganic compounds such as fillers, reinforcing fillers such as glass fibers and carbon fibers, mold release agents, fluidity improvers, and charge control There is no problem in supplying various additives such as additives and stabilizers to the extruder. These additives are preferably added simultaneously with the raw materials or after carrying out a crosslinking reaction.

(5) Step of discharging the cross-linked polyester resin subjected to the cross-linking reaction from the discharge unit 4 The resin after the cross-linking reaction is extruded from the discharge unit 4 and appropriately cooled, and then processed into a granular material by a granulator or a pulverizer. A method of cooling after granulation with a hot cutter or the like can also be used.

  Moreover, in order to remove the volatile component in the obtained crosslinked polyester resin between the crosslinking reaction part 7 and the discharge part 4, you may provide a devolatilization part as needed.

  Examples of the present invention are shown below. Evaluation was performed by the method shown below.

(Evaluation of uniformity of crosslinking reaction)
When the unsaturated polyester resin is subjected to a crosslinking reaction, a part thereof changes to a crosslinking component (THF insoluble component) having a high crosslinking density that does not dissolve in tetrahydrofuran (THF).

  The uniformity of the crosslinking reaction was evaluated by measuring the THF-insoluble content of the obtained crosslinked polyester resin by the following method.

  The resin discharged from the discharge part of the extruder was sampled at a frequency of once every 5 minutes, 6 samples were collected in 30 minutes, and the THF-insoluble content of each sample was measured.

From the minimum value, the maximum value and the average value of the measured values of the THF-insoluble matter, the uniformity of the crosslinking reaction was evaluated by the following formula.
Reaction uniformity = (maximum value−minimum value) / average value × 100
A reaction uniformity value of 20 or less indicates that the reaction is uniform and the physical properties are stable.

  The THF insoluble matter was measured by the following method.

  About 2 g of Celite 545 (manufactured by Kishida Chemical Co., Ltd.) is put into a cylindrical glass filter 1GP100 (manufactured by Shibata Chemical Co., Ltd.) having an inner diameter of 3.5 cm, and the glass filter is used until the height of the Celite 545 layer does not change. I tapped it lightly on the cork stand. This operation was repeated four times, and Celite 545 was filled into a glass filter so that the height of the Celite 545 layer was 2 cm from the filter surface. The glass filter filled with Celite 545 was dried at 105 ° C. for 3 hours or more and weighed (Yg).

Next, about 0.5 g of the sample was put in an Erlenmeyer flask and precisely weighed (Xg), then 50 ml of THF was added, and the sample was dissolved under reflux of THF by heating in a 70 ° C. water bath for 3 hours.
This solution was put into a glass filter packed with Celite 545 and suction filtered. The glass filter capturing the THF-insoluble matter was dried at 80 ° C. for 3 hours or more, the weight was weighed (Zg), and the THF-insoluble matter was calculated according to the following formula.
THF-insoluble matter = (ZY) / X × 100 (mass%)
<Synthesis example 1 of unsaturated polyester resin>
95 mol parts of terephthalic acid as an acid component, 5 mol parts of fumaric acid as a carboxylic acid compound having an unsaturated double bond, 65 mol parts of ethylene glycol and 40 mol parts of neopentyl glycol as alcohol components, and with respect to the total acid components 1000 ppm of tributyltin oxide was charged into a reaction vessel equipped with a distillation column. Next, the temperature was raised and heated so that the temperature in the reaction system became 260 ° C., and this temperature was maintained, and the esterification reaction was carried out until no water was distilled from the reaction system. Next, the temperature in the reaction system was 225 ° C., the pressure in the reaction vessel was reduced, and the condensation reaction was carried out while distilling the diol component from the reaction system. The reaction was continued until the viscosity of the reaction system increased with the reaction and the torque of the stirring blade reached a value indicating the desired softening temperature. And when the predetermined torque was shown, the reaction material was taken out and cooled, and unsaturated polyester resin (a) was obtained. Table 1 shows the charged composition and characteristic values of the unsaturated polyester resin (a).

<Synthesis example 2 of unsaturated polyester resin>
80 mol parts of terephthalic acid as an acid component, 20 mol parts of fumaric acid as a carboxylic acid compound having an unsaturated double bond, 80 mol parts of ethylene glycol and 40 mol parts of 1,4-cyclohexanedimethanol as alcohol components, 1500 ppm of antimony trioxide with respect to the acid component and 2000 ppm of hindered phenol compound (AO-60 manufactured by Asahi Denka Kogyo Co., Ltd.) with respect to the total acid component were charged into the same reaction vessel as in Synthesis Example 1.

  Next, the temperature was raised and heated so that the temperature in the reaction system became 260 ° C., and this temperature was maintained, and the esterification reaction was continued until no water was distilled from the reaction system. Subsequently, the temperature in the reaction system was set to 270 ° C., the pressure in the reaction vessel was reduced, and a condensation reaction was carried out while distilling the diol component from the reaction system. The reaction was continued until the viscosity of the reaction system increased with the reaction and the torque of the stirring blade reached a value indicating the desired softening temperature. And when the predetermined torque was shown, the reaction material was taken out and cooled, and unsaturated polyester resin (b) was obtained. Table 1 shows the charged composition and characteristic values of the unsaturated polyester resin (b).

Example 1
Using a twin screw extruder (Toshiba Machine Co., Ltd. TEM-26SS, total screw length is approximately 64 times the screw diameter), the configuration is in accordance with FIG. 1 and degassed between the raw material supply unit 1 and the crosslinking initiator supply unit 3. Part 2 was provided.

  The operating conditions were: temperature control of the raw material supply unit 1 at 100 ° C., the subsequent melt mixing unit 6 at 140 ° C., and the crosslinking reaction unit 7 to the discharge unit 4 at 200 ° C. The number of rotations of the screw was 200 rpm.

  Using the feeder, the unsaturated polyester resin (a) no supply rate was 9 kg / h, and the unsaturated polyester resin (b) supply rate was 1 kg / h.

  A diaphragm vacuum pump was connected to the deaeration unit 2. After confirming that the melted polyester resin was discharged from the discharge part 4, the operation of the vacuum pump was started, and the pressure gauge of the deaeration part 2 was adjusted to indicate -34.6 kPa (gauge pressure).

  Subsequently, the organic peroxide (I-1) was supplied from the crosslinking initiator supply unit 3 into the extruder at a temperature of 80 ° C. at a rate of 163 g / h using a plunger metering pump. The organic peroxide (I-1) was a release agent (Nihon Seiki (Nippon Seiki) (11 mass parts of 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane) heated to 80 ° C. SP-0160) manufactured by Co., Ltd. was added to 89 parts by mass.

  Table 2 shows the evaluation results of the crosslinked polyester resin discharged from the discharge portion 4.

(Example 2)
The operation was performed in the same manner as in Example 1 except that the pressure in the deaeration unit 2 was adjusted to -48 kPa (gauge pressure). Table 2 shows the evaluation results of the cross-linked polyester resin discharged from the discharge part 4.

(Example 3)
The operation was performed in the same manner as in Example 1 except that the pressure in the deaeration unit 2 was adjusted to −61.3 kPa (gauge pressure). Table 2 shows the evaluation results of the cross-linked polyester resin discharged from the discharge part 4.

(Comparative Example 1)
The operation was performed in the same manner as in Example 1 except that the operation of the vacuum pump connected to the deaeration unit 2 was stopped. Since air and moisture were not removed from the melt-mixed polyester resin, the polyester resin foamed irregularly at the outlet of the discharge section 4 and could not be operated safely.

(Comparative Example 2)
Using a twin screw extruder (Ikegai PCM-30, total screw length is approximately 40 times the screw diameter), the configuration is in accordance with FIG. 2, and deaeration is performed between the raw material supply unit 1 and the crosslinking initiator supply unit 3. The part 2 was not provided, but a deaeration part 2 ′ was provided after the crosslinking reaction part, and a diaphragm vacuum pump was connected.

  The operating conditions were such that the temperature of the raw material supply unit was 100 ° C., and the temperature from the crosslinking reaction unit 7 to the discharge unit 4 was 200 ° C. The number of rotations of the screw was 200 rpm.

  Extruder from feed unit 1 at a rate of 4.2 kg / h using a feeder to mix 85 parts by mass of polyester resin (a) and 15 parts by mass of polyester resin (b) to 100 parts by mass Supplied to. Subsequently, the organic peroxide (I-1) diluted with a release agent was supplied at a temperature of 80 ° C. using a microfeeder manufactured by Furue Science Co., Ltd. at a rate of 84.0 g / h. Part 3 was fed into the extruder.

  The organic peroxide (I-1) was a release agent (Nihon Seiki ( SP-0160) manufactured by Co., Ltd. was added to 89 parts by mass.

  Table 2 shows the evaluation results of the cross-linked polyester resin discharged from the discharge part 4 with the pressure of the degassing part 2 'set to -23 kPa (gauge pressure). Since degassing was not performed before the crosslinking reaction, the uniformity of the crosslinking reaction was low.

It is a figure which shows an example of the extruder of this invention. It is a figure which shows the structure of the extruder implemented in the comparative example 2.

DESCRIPTION OF SYMBOLS 1 Raw material supply part 2 Deaeration part 3 Crosslinking initiator supply part 4 Discharge part 5 Screw 6 Melt mixing part 7 Crosslinking reaction part 2 'deaeration part

Claims (3)

Using an extruder having a raw material supply unit 1, a deaeration unit 2, a crosslinking initiator supply unit 3, and a discharge unit 4,
The manufacturing method of the crosslinked polyester resin which performs the process of (1)-(5) sequentially.
(1) Step of supplying polyester resin A having an unsaturated double bond from raw material supply unit 1 (2) Step of melting and mixing polyester resin A between raw material supply unit 1 and degassing unit 2 (3) Degassing Step (4) for degassing polyester resin A melt-mixed in part 2 Step (5) for supplying cross-linking initiator to degassed polyester resin A from cross-linking initiator supply unit 3 and performing cross-linking reaction Step of discharging the cross-linked polyester resin cross-linked from the discharge unit 4 The method for producing a crosslinked polyester resin according to claim 1, wherein the deaeration pressure is -40 kPa (gauge pressure) or less. The method for producing a crosslinked polyester resin according to claim 1 or 2, wherein the crosslinked polyester resin is a binder resin for toner.