JPH05156142A - Production of polyester composition - Google Patents

Abstract

PURPOSE:To provide a polyester compsn. useful as a raw material of film. CONSTITUTION:A polyester is mixed on a vented molding machine with a water slurry contg. 5-50wt.% cross-linked org. particles having a void content of 40% or lower and a mean particle diameter of 0.05-3mum in an amt. (in terms of the particles) of 0.1-20wt.% based on the polyester, thus giving the objective polyester compsn.

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 polyester composition containing crosslinked polymer particles by using a vent type molding machine.

[0002]

2. Description of the Related Art Polyester films typified by polyethylene terephthalate have excellent physical and chemical properties, and by utilizing their excellent transparency, graphic arts, displays, packaging materials, etc. Has been prized as. It is also widely used in the fields of magnetic recording media such as base films and capacitor derivatives.

Conventionally, in order to improve the running property and abrasion resistance of the polyester film, the surface of the film is appropriately roughened, but it is not always successful to satisfy these properties to a high degree. I haven't. For example, when using so-called precipitated particles that are generated from the catalyst residue during the production of polyester as the fine particles, since it is a method of generating particles by the reaction of the catalytic metal compound and the phosphorus compound during the polycondensation of the polyester, the particles are It is difficult to control the amount and particle size and prevent the formation of coarse particles, and since the fine particles are easily broken by stretching,
The runnability and abrasion resistance of the film are poor, and it is difficult to recycle. Another method called addition method, in which particles of an inert inorganic compound such as calcium carbonate, titanium dioxide, calcium phosphate, etc. are added to the polyester, the particles are not broken or deformed by stretching, and are relatively steep. Although the runnability is improved by providing the projections, the particles have a poor affinity with polyester, so that the particles often detach from the film surface to form a white powder substance.

[0004]

DISCLOSURE OF THE INVENTION In view of the above circumstances, the inventors of the present invention have excellent dispersibility, runnability and abrasion resistance at the same time, and are sufficiently excellent in various properties required as a film. As a result of intensive studies to provide a raw material for forming a film, it was found that such required characteristics can be satisfied if the crosslinked polymer particles are blended by a specific blending method, and the present invention has been completed.

That is, the gist of the present invention is to produce a crosslinked organic particle-containing polyester using a venting molding machine, having a porosity of less than 40% and an average particle diameter of 0.05 to 3 μm.
The water slurry containing 5 to 50% by weight of the crosslinked organic particles of m is 0.1 with respect to the polyester in terms of the crosslinked organic particles.
It exists in the manufacturing method of the polyester composition characterized by adding so that it may become a ratio of -20 weight%.

The present invention will be described in more detail below. The polyester in the present invention means terephthalic acid, 2,6-
An aromatic dicarboxylic acid such as naphthalenedicarboxylic acid or an ester thereof and a polyester obtained by using ethylene glycol as a main starting material are shown, but other third component may be contained. In this case, examples of the dicarboxylic acid component include isophthalic acid, terephthalic acid, 2,
One of 6-naphthalenedicarboxylic acid, adipic acid, sebacic acid and the like can be used. As the glycol component, one or more of diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and the like can be used. In any case, the polyester of the present invention refers to a polyester in which 80% or more of repeating structural units have ethylene terephthalate units or ethylene-2,6-naphthalate units.

The crosslinked organic particles used in the present invention include, for example, one or more monovinyl compound (A) having only one aliphatic unsaturated bond in the molecule and two or more monovinyl compounds as a crosslinking agent in the molecule. A compound having an aliphatic unsaturated bond (B)
Is one or more copolymer particles. Specific examples of the compound (A) include acrylic acid, methacrylic acid and their alkyl or glycidyl esters, maleic anhydride and its alkyl derivatives, vinyl glycidyl ether, vinyl acetate, styrene, and alkyl-substituted styrene. .. In addition, examples of the compound (B) include divinylbenzene, divinylsulfone, ethylene glycol dimethacrylate and the like. One or more kinds of the compounds (A) and (B) are used, but a compound having a nitrogen atom or ethylene may be copolymerized. Specific cross-linking organic particle compositions include, for example, methyl methacrylate / divinylbenzene copolymer, styrene / divinylbenzene copolymer, methyl methacrylate / styrene /
Divinylbenzene copolymer, methyl methacrylate / ethylene glycol dimethacrylate copolymer, methyl methacrylate / ethylene glycol dimethacrylate / divinylbenzene copolymer, styrene / ethylene glycol dimethacrylate / divinylbenzene copolymer and the like can be mentioned.

Further, one embodiment of the production of crosslinked organic particles used in the present invention is as follows. That is, after dissolving a predetermined amount of a water-soluble polymerization initiator such as hydrogen peroxide or potassium persulfate in an aqueous medium, one or more compounds (A) and one or more compounds (B) are added. Add the mixed solution. Thereafter, the reaction is carried out at a temperature not lower than the decomposition start temperature of the polymerization initiator, preferably at 30 to 90 ° C. for about 3 to 10 hours with stirring. At that time, depending on the monomer composition, some aggregated particles may be generated. In this case, a dispersion stabilizer such as an emulsifier may be added in order to maintain the dispersion stability of the particles. In any case, the particles are obtained as a uniformly dispersed water slurry. Further, the method for producing the crosslinked organic particles does not matter as long as it satisfies the gist of the present invention.

The porosity of the crosslinked organic particles used in the present invention is 4
Less than 0%, preferably less than 20%, more preferably 0
%. If the porosity exceeds 40%, the evaporation efficiency of water in the vent type extruder is lowered, and the intrinsic viscosity of the polyester tends to be lowered, which is not preferable. The average particle size of the crosslinked organic particles used in the present invention is 0.05 to 3 μm, preferably 0.1 to 1 μm. Average particle size is 0.05 μm
When it is less than the above range, the running property and abrasion resistance of the film are insufficient. On the other hand, if the average particle size exceeds 3 μm, the surface roughness becomes too large, which is not preferable.

The amount of the crosslinked organic particles blended with the polyester is 0.01 to 20% by weight, preferably 0.1 to 10%.
%, More preferably 1 to 5% by weight. Further, the concentration of the water slurry containing crosslinked organic particles is 5 to 50% by weight,
It is preferably 20 to 40% by weight. If the concentration of the water slurry containing crosslinked organic particles is less than 5% by weight, the intrinsic viscosity of the polyester tends to decrease, which is not preferable. If the concentration of the water slurry exceeds 50% by weight, the fluidity of the water slurry is lowered, so that the workability is lowered and the dispersibility in the polyester is deteriorated, which is not preferable.

In the present invention, the particle-containing polyester is obtained by adding the cross-linked organic particle-containing water slurry to the polyester in a vent type molding machine, removing water by heating under reduced pressure, and melt-kneading. The vent type molding machine is a molding machine having at least one vent hole, and may be, for example, an extrusion molding machine or an injection molding machine. At least one of the vent holes for removing water is usually kept at a reduced pressure. The vacuum degree of the vent hole is preferably maintained at 100 mmHg or less, more preferably 50 mmHg.
g or less, particularly preferably 20 mmHg or less.

When the method of the present invention is used, the crosslinked organic particles can be directly added to and mixed with the polyester in the state of an aqueous slurry, the intrinsic viscosity of the obtained polymer is not lowered so much, and the polyester can have high crosslinking organic particles. It can be included in the concentration. Therefore, it is also possible to produce a polyester containing the particles in a high concentration, and dilute the polyester with substantially no particles before use.

Further, the crosslinked organic particles in the obtained polyester are uniformly dispersed. Therefore, when formed into a stretched film, uniform surface protrusions are obtained, and in particular, the excellent running property and abrasion resistance are utilized. , As a base film for magnetic recording media such as magnetic tapes and floppy disks, for capacitors, for photoengraving, for thermal transfer,
It is extremely useful as a base film for various fields such as packaging, transfer marks, gold and silver threads.

Further, to the extent that the gist of the present invention is not impaired,
Other particles, for example, precipitated particles, inorganic particles such as calcium carbonate, titanium dioxide, alumina and silica, and a phosphorus compound as a coloring preventing agent may be used in combination.

[0015]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples without departing from the gist thereof. The measuring methods and definitions of various physical properties and characteristics in the examples are as follows. In the examples and comparative examples, "part" means "part by weight".

(1) Porosity The pore volume of the particles was measured by a mercury porosimeter, and calculated from the pore volume and the specific gravity of the particles by the following formula. Porosity (%) = (pore volume / (1 / specific gravity) + pore volume) × 100 (2) Average particle diameter The particle diameter was measured by an electron micrograph. The average particle size was calculated as the particle size (diameter) at the point where the weight fraction of the equivalent sphere conversion value was 50%.

(3) Intrinsic Viscosity 1 g of polymer is added to phenol / tetrachloroethane = 50
Dissolve in 100 ml of 50/50 (weight ratio) mixed solvent and
It was measured at 0.0 ° C. (4) Particle Dispersibility in Chip After the chip was cut into ultrathin sections of about 0.2 μm by an ultramicrotome, the dispersibility of particles in the chip was evaluated by the transmission electron microscope temperature according to the following criteria.

A: Almost no secondary agglomeration was observed, and the dispersion was very good. B: Slight secondary agglomeration was present and inferior in dispersibility. C: Secondary agglomeration was present with considerable frequency. Very poor dispersibility (5) Number of coarse protrusions Aluminum was vapor-deposited on the film surface, and measurement was performed using a two-beam interference microscope. The measurement wavelength was 0.54 μm, and the number showing the interference fringes of the third order or higher was converted and shown per 10 cm ² .

(6) Running property Evaluation was made by the slip property of the film. The slipperiness was measured by the device shown in Fig. 1 by contacting the film on a fixed hard chrome-plated metal roll (diameter 6 mm) at a winding angle (θ) of 135 °, applying a load of 53 g (T ₂ ) to one end, and applying a load of 1 m / mim. This was run at a speed, the resistance force (T _{1 (g)} ) at the other end was measured, and the friction coefficient was calculated by the following formula.

[0020] μd = (1 / θ) ln (T 1 / T 2) = 0.424ln (T 1/53) (7) were evaluated wear properties due to abrasion characteristic white powder generation amount. That is, the first
The film was run for 1000 m in the running system shown in the figure, and the amount of worn white powder adhering to the fixed pin made of hard chrome of 6 mmφ was visually evaluated and classified by the ranks shown below. In addition,
The film speed is 13m / min, the tension is about 200g,
θ = 135 °.

Rank A: No adhesion Rank B: Small amount adhesion Rank C: Small amount (more than Rank B) adhesion Rank D: Very much adhesion Example 1 [Production of crosslinked organic particles] 1500 parts of demineralized water After 3.5 parts of potassium persulfate as a water-soluble polymerization initiator and 0.007 parts of sodium lauryl sulfate as a dispersion stabilizer were added and uniformly dissolved, 60 parts of styrene, 20 parts of ethylene glycol dimethacrylate, and 20 parts of divinylbenzene were added. Parts of mixed solution were added. Then, polymerization was carried out at 70 ° C. for 8 hours while stirring in a nitrogen gas atmosphere. The reaction rate was 98%, and the average particle size of the obtained particles was 0.60 μm.

Next, the obtained aqueous slurry was concentrated at 70 ° C. under reduced pressure. The concentration of the obtained water slurry containing crosslinked organic particles was 40%. [Production of Polyester Chip Containing Particles] An undried polyethylene terephthalate chip having an intrinsic viscosity of 0.660 containing 0.2% by weight of water was used in a vent type twin-screw extruder, and finally the particle content in the polyester chip was 5 A water slurry containing crosslinked organic particles having an average particle size of 0.60 μm (12% by weight / polyester chips) was added so that the amount of the mixture would be 10% by weight. The vent hole was maintained at a vacuum degree of 10 mmHg or less, and melt extrusion was performed at a resin temperature of 285 ° C. to obtain crosslinked organic particle-containing polyethylene terephthalate chips. The intrinsic viscosity of the obtained chips was 0.642, and the decrease in the intrinsic viscosity was at a level without any problem.

[Production of Polyester Film Containing Particles]
The obtained polyester chips are dried and melt-extruded at 290 ° C. to form an amorphous sheet, and then 3.5 ° C. at 90 ° C.
Stretched 3.7 times in the transverse direction at 110 ° C and 3 times at 210 ° C
A heat treatment was performed for a second to obtain a film having a thickness of 15 μm, and its characteristics were evaluated.

Example 2 In Example 1, the particle size of the crosslinked organic particles was 0.30 μm.
A polyester chip and a film were obtained in the same manner as in Example 1 except that the above was changed, and the characteristics thereof were measured. Example 3 In Example 1, the addition amount of the crosslinked organic particles was 10% by weight.
A polyester chip and a film were obtained in the same manner as in Example 1 except that the above was changed, and the characteristics thereof were measured.

Comparative Example 1 Example 1 was repeated, except that the obtained cross-linked organic particle-containing aqueous slurry was dried in a spray dryer and the obtained dried particles were used in the production of particle-containing polyester chips. A polyester chip and a film were obtained in the same manner as in (1) and their properties were measured.

Comparative Example 2 A polyester chip and a film were obtained in the same manner as in Example 1 except that titanium oxide powder was used in place of the obtained cross-linked organic particle-containing water slurry, and the characteristics thereof were measured. .. The results obtained above are summarized in Tables 1 and 2 below.

[0027]

[Table 1]

[0028]

[Table 2]

As shown in Tables 1 and 2, the films of Examples 1 to 3 which are the categories of the present invention all have excellent particle dispersibility, runnability and abrasion characteristics, and are, for example, base films for magnetic tapes. On the other hand, when the particle powder is used as in Comparative Example 1 and Comparative Example 2, the particle dispersibility in the polyester chip is inferior, so that the running property and the abrasion property are inferior and the coarse protrusions are also present. It will occur frequently.

[0030]

EFFECT OF THE INVENTION By using the method for producing a polyester of the present invention, it is possible to directly add and mix the crosslinked organic particle-containing water slurry dispersed in the state of primary particles to the polyester, and to obtain a uniformly dispersed crosslinked organic particle-containing polyester. Is easily obtained, the film produced using the obtained polyester has a flat and uniform surface, is excellent in runnability and especially abrasion characteristics, and can be applied to various applications. Industrial value is high.

[Brief description of drawings]

FIG. 1 is a schematic view of a running system of an apparatus for evaluating the runnability of a film.

FIG. 2 is a schematic view of a running system of an apparatus for evaluating the abrasion resistance of a film.

[Explanation of symbols]

 (1), (4): SUS-420-J2 (6 mmφ) (2): Inlet tension meter (3): Outlet tension meter (5): Tension meter (θ): Winding angle

Claims (1)

[Claims] 1. When producing a crosslinked organic particle-containing polyester using a venting molding machine, the porosity is less than 40%,
5 to 5 crosslinked organic particles having an average particle size of 0.05 to 3 μm
A method for producing a polyester composition, comprising adding 50% by weight of a water slurry to the polyester in an amount of 0.1 to 20% by weight in terms of crosslinked organic particles.