JP3139082B2 - Thermoplastic polyester composition and film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester composition and a film having excellent flatness, slip stability and abrasion resistance when molded.

[0002]

2. Description of the Related Art In general, thermoplastic polyesters such as polyethylene terephthalate have excellent mechanical and chemical properties, and are widely used as molded articles such as films and fibers. In particular, polyethylene terephthalate films are widely used in fields such as base films of magnetic recording media, photographs, capacitors, and packaging. The characteristics required of films used for these applications are various, but characteristics such as flatness, slipperiness, and abrasion resistance are particularly important. For example, when used as a base film for magnetic tape, if the slipperiness and abrasion resistance are insufficient, the friction between the coating roll and the film increases during the manufacturing process of the magnetic tape, causing wrinkles and scratches on the film. I do. In addition, abrasion powder of the film is likely to be generated, and a coating omission occurs in the step of applying the magnetic layer, which may cause a drop out of magnetic recording.

Hitherto, as a method for improving the slipperiness of a film, many proposals have been made to incorporate inorganic particles such as titanium dioxide, calcium carbonate and silicon dioxide into polyester. However, since these inorganic particles are hard and have low affinity with polyester, for example, when used as a film, a contact with a roll during calendering in the step of applying a magnetic layer or during film running,
When an external force is applied due to contact between the films at the time of winding, the film easily falls off, causing shavings, deterioration of slipperiness, and generation of surface scratches. In addition, since the dropped particles themselves are hard, shavings and surface flaws increase synergistically with time. If a large amount of shavings is generated and the surface is scratched in this way, the magnetic layer is coated in a step of applying the magnetic layer, causing dropout. further,
Contamination of the calendar roll in the step of applying the magnetic layer significantly deteriorates workability in manufacturing a magnetic recording film. That is, a hard particle such as an inorganic particle is a problem to be solved in that external force is easily received directly and the abrasion resistance is improved.

On the other hand, organic polymer fine particles are disclosed, for example, in JP-B-63-45409 and JP-A-59-217.
No. 755 and Japanese Unexamined Patent Publication No. 2-189359 propose crosslinked polymer fine particles, but none of these methods has sufficient abrasion resistance. Also, Japanese Patent Laid-Open No. 3-1
No. 43929 proposes crosslinked polymer particles that deform in the film, but it is difficult to obtain a film that maintains the balance between slipperiness and abrasion resistance because the entire particles are deformed. The change in slipperiness when it is made to be large is not preferable.

[0005]

The inventors of the present invention have made intensive studies and found that the use of organic polymer fine particles having a soft portion and a hard portion significantly improved flatness, slipperiness, and abrasion resistance. I found that I can do it .
An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art, and to provide a thermoplastic polyester composition having excellent flatness, slip stability, and abrasion resistance when formed into a film or fiber. is there. In addition, that the sliding stability is good in the present invention means that the fluctuation of the friction coefficient when the film is run for a long time is small.

[0006]

The object of the present invention can be attained by a thermoplastic polyester composition containing fine organic polymer particles having a soft part and a hard part.

The polyester used in the present invention is produced from a dicarboxylic acid having an aromatic dicarboxylic acid as a main acid component, an ester-forming derivative thereof, and glycol. Examples of the aromatic dicarboxylic acid in the present invention include terephthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, and isophthalic acid. Examples of the glycol component in the present invention include aliphatic glycols such as ethylene glycol, butanediol, tetramethylene glycol, and hexamethylene glycol, and alicyclic diols such as cyclohexanedimethanol. As the polyester in the present invention, for example, those containing alkylene terephthalate or alkylene naphthalate as a main component are preferable. These polyesters may be homopolyesters or copolyesters. Examples of non-polymerized components include aliphatic dicarboxylic acids such as adipic acid and sebacic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, polyethylene glycol and polypropylene glycol.

The organic polymer fine particles of the present invention have a soft part and a hard part. As a means for confirming the structure, for example, there is a method of measuring the compression behavior of particles. In the method shown in FIG. 1, first, particles are dispersed on a lower indenter 1 and fine particles 3 are placed between an upper pressing indenter 2 and a lower indenter 1.
Is fixed. Then, a load is applied at a constant increase rate, and the amount of deformation of the fine particles and the load are automatically measured. At this time, if the particles have a soft part and a hard part, a discontinuous point such as point 1 is generated on a curve in which force and deformation are plotted as shown in FIG. Such a phenomenon also occurs when a particle is broken. In this case, a curve like a dashed line is taken, so that the particle can be distinguished from a broken. Note that the dotted line in the figure is a curve in the case where only a soft portion is provided. The discontinuous point may appear not only once but also several times during the measurement.

The organic fine particles of the present invention are not particularly limited as long as they have a soft part and a hard part. For example, polystyrene or crosslinked polystyrene particles, styrene-acrylic and acrylic crosslinked particles, styrene-methacrylic and methacrylic Particles such as vinyl-based particles such as cross-linked particles, benzoguanamine / formaldehyde, silicone, polytetrafluoroethylene, polyphenylester, and phenolic resin are included, but at least a portion of the particles constituting the particles is insoluble in polyester. Any particles may be used as long as they are organic polymer fine particles. Preferably, a monovinyl compound (A) generally having only one aliphatic unsaturated bond in the molecule and a compound (B) having two or more aliphatic unsaturated bonds in the molecule as a cross-linking agent are preferably used. Polymers.

Examples of the compound (A) in the above-mentioned copolymer include aromatic monovinyl compounds such as styrene, α-methylstyrene, fluorostyrene and vinylville, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, methyl acrylate, and the like. Ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, hexadecyl acrylate, 2-ethylhexyl acrylate, 2
Acrylate monomers such as -hydroxyethyl acrylate, glycidyl acrylate, N, N'-dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate;
Isopropyl methacrylate, butyl methacrylate,
sec-butyl methacrylate, allyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate,
Methacrylic acid ester monomers such as N, N'-dimethylaminoethyl methacrylate; mono- or dicarboxylic acids and acid anhydrides of dicarboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid; amide monomers such as acrylamide and methacrylamide Can be used.

As the compound (A), those having the following structural formula 1 are preferable, and those having 4 or more carbon atoms of R ₂ are preferable for providing a flexible portion. Particularly preferably, when the compound (A) has a single-component polymer structure, its glass transition temperature is desirably equal to or lower than the glass transition temperature of the polyester used in the present invention. Is 50 ° C. or less, preferably 20 ° C.
The temperature is more preferably 0 ° C. or lower. Specifically, acrylate monomers such as butyl acrylate, octyl acrylate, dodecyl acrylate, hexadecyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate, sec-
Methacrylate monomers such as butyl methacrylate, hexyl methacrylate, hexadecyl methacrylate, and 2-ethylhexyl methacrylate are preferably used.

On the other hand, in order to provide a hard portion, the glass transition temperature of a single-component polymer structure is higher than the glass transition temperature of the compound (A) used for providing the soft portion. The difference is desirably large, preferably the difference is 20 ° C. or more, more preferably 40 ° C. or more. As a monomer forming such a polymer, styrene, methyl acrylate, methyl methacrylate and the like are preferable.

[0013]

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Examples of the compound (B) include a divinylbenzene compound, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
Or ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate,
Examples include polyacrylates and methacrylates such as 1,3-butylene glycol dimethacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate. Generally, it is desirable to increase the amount of the compound (B) to provide a hard part, and to reduce the amount of the compound (B) to provide a soft part.
Among the compounds (B), it is preferable to use divinylbenzene, ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate.

It is preferable to use a mixture of two or more of these compounds (A) and (B) in producing particles having a soft part and a hard part. further,
Components other than the compounds (A) and (B) may be added, and coated with a trace amount of an inorganic substance to improve heat resistance and dispersibility.
A surface treatment or the like for improving affinity may be performed.

Preferred examples of the composition of the organic polymer fine particles of the present invention include butyl acrylate-divinylbenzene copolymer, octyl acrylate-divinylbenzene copolymer, and 2-ethylhexyl acrylate.
Crosslinked polymer fine particles such as divinylbenzene copolymer, 2-ethylhexyl acrylate-ethylene glycol dimethacrylate copolymer, hexyl methacrylate-divinylbenzene copolymer, and 2-ethylhexyl methacrylate-divinylbenzene copolymer are exemplified. Further, fine particles may be produced in a three-component system such as a styrene-butyl acrylate-divinylbenzene copolymer and a styrene-hexyl methacrylate-divinylbenzene copolymer.

The method for producing organic polymer fine particles of the present invention comprises:
The method for producing the crosslinked polymer fine particles will be described as an example. For example, there is a method in which the compounds (A) and (B) are mixed and the mixture is produced by the following emulsion polymerization. (A) A soap-free polymerization method, that is, a method in which no emulsifier is used or polymerization is performed using an extremely small amount of an emulsifier. (B) A seed polymerization method in which polymer particles are added to a polymerization system prior to emulsion polymerization and emulsion polymerization is performed. (C) A core-shell polymerization method in which a part of the monomer component is emulsion-polymerized and the remaining monomer is polymerized in the polymerization system. (D) JP-A-54-97582 and JP-A-54-97582
-126288, a polymerization method using Eugelstatt or the like. At this time, the same or different compounds (A) and (B)
May be further added. For example, a method of changing the concentration of the compound (A) or (B) in the system in order to give a structure different from that after particles having a certain uniform structure is formed. No.

In order to particularly improve the abrasion resistance and the sliding stability of the molded article, it is preferable that an inflection point appears on the curve until the particle is deformed by 80% when the compression behavior of the particle is measured. It is desirable that an inflection point appears by 60%.

When the particle diameter ratio of the organic polymer fine particles contained in the film is 1.1 to 5.0, the sliding stability,
Good abrasion resistance. In particular, the particle size ratio is preferably 1.2 to 4.0. This particle size ratio may be formed at a stage before being formed into a film, but is preferably formed by stretching because the affinity is improved. Here, the particle diameter ratio is a ratio calculated from the maximum diameter and the minimum diameter of the particles.

The average particle size of these organic polymer fine particles is
0.001 to 3 μm, preferably 0.005 to 2 μm for optimizing the slipperiness of the molded product and the height of the projections formed on the surface.
m, more preferably 0.010 to 1 μm.

The amount of the organic polymer particles added to the polyester is 0.00.0 parts by weight based on 100 parts by weight of the polyester.
01 to 20.0 parts by weight, preferably 0.005 to 10.
0 parts by weight, more preferably 0.01 to 8.0 parts by weight.

The method of adding the organic polymer fine particles of the present invention to polyester is not particularly limited. For example, the organic polymer fine particles may be added as a glycol slurry of the polyester raw material during the polyester production step, that is, during the transesterification, esterification, or polycondensation reaction, or may be added to the molten polyester. Can be added during kneading. The slurry concentration is 0.5 to 20% by weight.
The degree is appropriate.

When organic polymer fine particles having a soft part and a hard part are added to the polyester, not only the particles do not easily fall off, but also high and stable projections can be obtained.
A polyester composition having excellent abrasion resistance and sliding stability when formed into a film can be obtained.

Further, the polyester of the present invention contains a metal compound such as lithium, sodium, calcium, magnesium, manganese, zinc, antimony, germanium, titanium or the like, which is usually used in the production of polyester, as a catalyst, and phosphorus as a coloring inhibitor. It may contain inert particles other than the compound and the organic polymer fine particles.

[Measurement of Physical Properties and Evaluation of Effect] The method of measuring physical properties and the method of evaluating effects in the present invention are as follows.

A. Average particle diameter After photographing the particles with an electron microscope, the diameters of the particles were individually measured, and the particle equivalent sphere diameter corresponding to 50% by volume was determined and defined as the average particle diameter.

B. Particle diameter ratio The film was cut, the cross section in the longitudinal direction was observed, the maximum diameter and the minimum diameter of each particle were measured, and the ratio was calculated. Further, an arithmetic mean was obtained and defined as a particle size ratio.

C. Structure of particles Micro compression tester (MCTM-20) manufactured by Shimadzu Corporation
Load speed: 0.0145 gf / s
The amount of deformation was measured by applying a load of 0 to 1 gf, and when a discontinuous point shown in FIG. 2 occurred in a curve plotting the force and the amount of deformation, it was assumed that the curve had a soft part and a hard part. Hereinafter, the structure of particles having a soft part and a hard part is referred to as a composite structure, and the others are referred to as a single structure.

D. Intrinsic viscosity of polymer Measured at 25 ° C using o-chlorophenol as a solvent.

E. The abrasion resistance of the film The abrasion resistance of the film was judged from the following characteristics of both the guide roll stain and the calendar stain. (1) Dirt on guide roll (abrasion resistance (1)) After drying the polyester composition at 160 ° C, it was melt-extruded into a sheet at 290 ° C to obtain an unstretched film. The film was further stretched 3.6 times in the longitudinal direction and 3.4 times in the horizontal direction at 90 ° C. and heat-treated at 220 ° C. for 10 seconds to obtain a film having a thickness of 12 μm. Further, the obtained film was slit into 1/2 inch, and a tape running tester TBT-300 was used.
Using a mold (Yokohama System Laboratory Co., Ltd.)
After running 2000 times repeatedly in 50% RH atmosphere,
The amount of white powder generated on the guide roll surface is visually determined. Here, the guide diameter is 6 mmφ, the guide material is SUS27 (surface roughness 0.2S), and the winding angle is 180.
°, the running speed is 6.0 cm / sec. The ranking was as follows, and the first and second grades were accepted. Grade 1: Very low generation of white powder, achieving the purpose. 2nd grade: The generation of white powder is small, and the objective is achieved. Grade 3: White powder is slightly generated, and the purpose is not achieved. Grade 4: The generation of white powder is very large, and the purpose is not achieved. (2) Calender stain (abrasion resistance (2)) The tape coated with the magnetic layer is subjected to a temperature of 70 using a small test calender (steel roll, nylon roll, 5-stage type, nylon roll in contact with the base film surface).
It calenders at 200 degreeC and linear pressure: 200 kg / cm. After the above treatment is continued for a total of 20,000 m, the white powder adhered to the nylon roll generated by this treatment is observed, and the following ranking is performed. The first and second grades were accepted. Grade 1: Almost no white powder adheres. Second grade: White powder slightly adheres, but does not lead to trouble in processing process and product performance. 3rd grade: Many white powders adhered, causing troubles in the processing process and product performance, making it unusable.

F. Sliding stability of film A film obtained in the same manner as in D was slit to 1/2 inch, and a tape running tester TBT-300 type (trade name)
(Yokohama System Laboratory), 25 ℃, 50% RH
The vehicle was run in an atmosphere, and the initial μ _k0 and the μ _k100 when the _vehicle was run 100 times were determined by the following equation. The guide diameter is 4
mmφ, and the guide material is SUS27 (surface roughness of 0.
2S), winding angle 180 °, running speed 4.5cm
/ Sec. μ _k = 0.733 log (T ₁ / T ₂ ) T ₁ : output tension T ₂ : input tension _{Those having} a difference of 0.05 or less between μ _k0 and μ _k100 have good slipperiness and 0.03 or less. Is particularly good.

G. Surface roughness: Ra (μm) Measured by a stylus type surface roughness meter (cutoff value: 0.25 mm, measurement length: 4 mm; JIS-B-0
601 was followed. ).

[0033]

The present invention will be described in more detail with reference to the following examples. In the examples, “parts” means “parts by weight” unless otherwise specified. In addition, ()
The value in is the particle content in the film.

Example 1 (Method of producing polyester composition and film) 100 parts of dimethyl terephthalate, ethylene glycol 5
Eight parts, 0.06 part of magnesium acetate and 0.03 part of antimony trioxide as a catalyst are added, and methanol is distilled off while the temperature is raised to 230 ° C. to carry out a transesterification reaction.
Thereafter, 0.05 parts of trimethyl phosphate was added,
Styrene (30% by weight) having an average particle size of 1.0 μm and having a composite structure produced by a core-shell polymerization method dispersed as a 5% by weight ethylene glycol slurry.
2-Ethylhexyl acrylate (40% by weight) -divinylbenzene (30% by weight) copolymer particles are added so as to be 1% by weight in the polyester. Thereafter, the pressure was reduced while moving to a polycondensation reaction tank while raising the temperature to 290 ° C., and polycondensation was performed. The resulting polymer had an intrinsic viscosity of 0.620. The obtained polymer was diluted 3/10 times with particle-free polyethylene terephthalate, melt-extruded at 290 ° C. using an extruder, and quenched with a casting drum to obtain an unstretched sheet. Subsequently, this was stretched 3.6 times and 3.4 times at 90 ° C. in the longitudinal and transverse directions, respectively, to obtain a biaxially stretched film having a thickness of 12 μm. The particle characteristics, polymer characteristics, and film characteristics are as shown in Table 1, and the film was excellent in flatness, sliding stability, and abrasion resistance.

Examples 2 to 6 Polyester compositions and films were obtained in the same manner as in Example 1 except that the composition, particle size and amount of the organic polymer fine particles were changed. As shown in Table 1, the polyester composition of the present invention was able to satisfy each of flatness, sliding stability and abrasion resistance. When the monovinyl compound component of the organic polymer fine particles takes the structure of a polymer alone, when particles produced by using a glass transition temperature of 0 ° C. or less and a glass transition temperature of 20 ° C. or more are used, Sharpness was particularly good. In Example 4, a slight change in slipperiness was observed. In the particles of Example 5, small particles were synthesized with butyl acrylate (30% by weight) -divinylbenzene (70% by weight) at the initial stage of core-shell polymerization, and after the middle stage, butyl acrylate (70% by weight) -divinylbenzene (30% by weight) was synthesized. % By weight) to form particles having a predetermined particle size .
The film properties were good. In Example 6, the particle size ratio in the film was 1.0, and the film characteristics were slightly deteriorated.

Comparative Example 1 A polyester composition was polymerized in the same manner as in Example 1 except that colloidal silica particles were used as organic polymer fine particles to obtain a film. The properties of the particles and the properties of the obtained film are shown in Table 2, but the abrasion resistance could not be satisfied.

Comparative Examples 2 to 4 The polyester composition was polymerized in the same manner as in Example 1 except that the type and structure of the particles were changed to obtain a film. As shown in Table 2, when it deviated from the present invention, the abrasion resistance could not be satisfied. In Comparative Examples 3 and 4, a film was obtained using particles whose sliding stability was reduced due to the uniform structure, but the abrasion resistance was poor.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

Since the thermoplastic polyester composition of the present invention contains organic polymer fine particles having a soft portion and a hard portion, it has not only excellent running properties but also excellent affinity with the polyester and an external force. Particles are less likely to fall off when received. Therefore, it is possible to prevent the generation of white powder due to the falling off of particles, which has been a problem when adding inorganic particles, and to prevent the deterioration of slipperiness. It enables the preferred use as a product such as.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a method for measuring the strength (S ₁₀ ) of particles in the present invention.

FIG. 2 is a graph showing the relationship between the amount of deformation and the force in the measurement of the compression behavior of particles.

[Explanation of symbols]

 1 lower press indenter 2 upper press indenter 3 fine particles

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-189359 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 5/18 C08L 67/00-67 / 04

Claims (2)

(57) [Claims] 1. A thermoplastic polyester composition comprising organic polymer fine particles having a soft part and a hard part. 2. A thermoplastic polyester film containing the organic polymer fine particles according to claim 1 and having a particle size ratio of 1.1 to 5.0 in the film. .