JPH11228695A - Imide skeleton-containing ethylene naphthalate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject polymer capable of retaining the essential characteristics of a regular polyethylene naphthalate and forming a film having excellent delamination resistance and a yarn having fatigue resistance, by copolymerization of a specific amount of a prescribed bistrimellitimide compound. SOLUTION: This imide skeleton-containing polyethylene naphthalate (P) comprises a naphthalenedicarboxylic acid as a main dicarboxylic acid component, ethylene glycol as a main glycol component and is copolymerized with a bistrimellitimide component (R). The imide skeleton-containing polyethylene naphthalate contains 0.3-5 mol.% based on the total dicarboxylic acid component constituting the component P of a compound of the formula (X is a 2-16C saturated aliphatic chain) as the component R and <=3 mol.% based on the total glycol component constituting the component P of a diethylene glycol component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymerized polyethylene naphthalate, and more particularly, to a polyethylene naphthalate copolymerized with a specific imide compound.

[0002]

2. Description of the Related Art Polyethylene naphthalate has excellent mechanical and chemical properties, and particularly has excellent strength, Young's modulus, dimensional stability, hydrolysis resistance, heat resistance, gas barrier properties, and the like. Therefore, it is widely used for films, fibers and the like.

However, since polyethylene naphthalate has a rigid molecular structure, molded articles have several problems. For example, when a film is formed, delamination is apt to occur, and the peeled portion is whitened, In the production process of the biaxially stretched film, there has been a problem that the film is broken. Further, the fiber has a problem that it is inferior in fatigue resistance represented by knot strength and the like because of low elongation and toughness of the yarn, and is not suitable for long-term continuous use. As a means for solving these problems, it has been proposed to introduce various copolymer components into the molecular chain thereof, but a polymer having sufficient performance has not yet been obtained (Japanese Patent Application Laid-Open No. 8-104742). JP-A-8-504691, JP-A-8-34842, etc.).

On the other hand, Japanese Patent Application Laid-Open No. 4-180920 discloses a method of copolymerizing polyethylene naphthalate with a bis trimellitimide compound. However, the imide compound in the publication is intended only to improve Young's modulus, and the copolymerized naphthalate obtained by this method has not been able to solve the above-mentioned problems.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a film having improved delamination resistance while maintaining the excellent properties of regular polyethylene naphthalate, and an improved fatigue resistance. It is an object of the present invention to provide a copolymerized polyethylene naphthalate which gives a coated fiber.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above prior art, and as a result, polyethylene naphthalate obtained by copolymerizing a specific bistrimellitimide compound has a problem that the above prior art has. Can be solved, and the present invention has been completed.

That is, an object of the present invention is to provide an imide skeleton-containing polyethylene naphthalate obtained by copolymerizing a naphthalenedicarboxylic acid as a main dicarboxylic acid component, ethylene glycol as a main glycol component, and a bistrimellitic imide component. A bistrimellitic imide component represented by the following structural formula is contained in an amount of 0.3 to 5 mol% based on all dicarboxylic acid components constituting the imide skeleton-containing polyethylene naphthalate, and the content of the diethylene glycol component is imide skeleton-containing polyethylene. Not more than 3 mol% based on all glycol components constituting naphthalate,
Achieved by polyethylene naphthalate containing an imide skeleton.

[0008]

Embedded image

(Wherein, X represents a saturated aliphatic chain having 2 to 16 carbon atoms)

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, a main component of the imide skeleton-containing polyethylene naphthalate is polyethylene naphthalate in which a main dicarboxylic acid component is naphthalenedicarboxylic acid and a main glycol component is ethylene glycol. Here, “main” means that the component accounts for 90 mol% or more.

Examples of the naphthalenedicarboxylic acid include 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid is particularly preferred. .

The imide skeleton-containing polyethylene naphthalate of the present invention is obtained by copolymerizing a bistrimellitic imide compound represented by the following general formula with a copolymer component so as to account for 0.3 to 5 mol% based on the total dicarboxylic acid component. It needs to be polymerized.

[0013]

Embedded image

(In the formula, X represents a saturated aliphatic chain having 2 to 16 carbon atoms, and R represents hydrogen or a lower alkyl group.)

When the copolymerization amount of the bistrimellitic imide is less than 0.3 mol% based on the total amount of all the dicarboxylic acid components, the delamination resistance of the film and the bending fatigue of the fiber are not improved. If it exceeds 5 mol%,
It is not preferable because the crystallinity is impaired and the mechanical strength is poor.
The copolymerization amount of the bis trimellitimide compound is preferably 0.5 to 3 mol%, more preferably 1 to 2 mol%.
It is.

The compounds represented by the above general formula include N,
N'-ethylenebis (trimerimido), N, N '
-Tetramethylenebis (trimerimido), N,
N'-hexamethylenebis (trimeritimide),
N, N′-decamethylenebis (trimellitimide) and the like can be mentioned as preferable examples.

In the present invention, the copolymerized amount of the diethylene glycol component of the imide skeleton-containing polyethylene naphthalate must be 3 mol% or less based on the total glycol component. This diethylene glycol component was not added and copolymerized in the form of diethylene glycol or its ester-forming derivative as a copolymer component during the copolymer production reaction, but was produced as a by-product during the production reaction. When the copolymerization amount exceeds 3 mol%, the effect of improving the delamination resistance when the obtained polymer is a film and the fatigue resistance when the obtained polymer is a fiber are increased, but the crystallinity is impaired. Therefore, the mechanical strength is greatly reduced. The copolymerization amount is preferably at most 2.5 mol%, more preferably at most 2 mol%.

The imide skeleton-containing polyethylene naphthalate of the present invention is used in an amount not to impair the effects of the present invention, for example, 10 mol% or less, preferably 5 mol%, based on the total amount of all dicarboxylic acid components and bistrimellitimide components. % Of other dicarboxylic acids may be copolymerized, for example, terephthalic acid, isophthalic acid, phthalic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, benzophenone. Aromatic dicarboxylic acids such as dicarboxylic acid, phenylindanedicarboxylic acid, metal 5-sulfoxyisophthalate, phosphonium 5-sulfoxyisophthalate, oxalic acid, succinic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid, decalin dicarboxylic acid It can be mentioned aliphatic dicarboxylic acids and the like, and these may be either in a combination of two or more kinds thereof may be used alone.

Further, the imide skeleton-containing polyethylene naphthalate of the present invention may contain other glycols in a range that does not impair the effects of the present invention, for example, 10 mol% or less, preferably 5 mol% or less based on all glycol components. Copolymerization may be carried out, wherein other glycols include, for example, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, neopentylene glycol, polyethylene glycol, cyclohexanediol, Aliphatic glycols such as cyclohexanedimethanol, o-xylylene glycol, m-xylylene glycol, p-xylylene glycol, 1,4-bis (2-hydroxyethoxy) benzene, 1,4-bis ( - hydroxy-ethoxyethoxy)
Benzene, 4,4'-bis (2-hydroxyethoxy)
Biphenyl, 4,4'-bis (2-hydroxyethoxyethoxy) biphenyl, 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane, 2,2-bis [4- (2-hydroxyethoxyethoxy) Phenyl]
Propane, 1,3-bis (2-hydroxyethoxy) benzene, 1,3-bis (2-hydroxyethoxyethoxy) benzene, 1,2-bis (2-hydroxyethoxy) benzene, 1,2-bis (2- (Hydroxyethoxyethoxy) benzene, 4,4'-bis (2-hydroxyethoxy) diphenylsulfone, 4,4'-bis (2-
Aromatic glycols such as hydroxyethoxyethoxy) diphenylsulfone, hydroquinone, 2,2-bis (4-
(Hydroxyphenyl) propane, resorcin, catechol, dihydroxynaphthalene, dihydroxybiphenyl, diphenols such as dihydroxydiphenylsulfone, etc., and may be used alone or in combination of two or more.

Although the molecular structure of the polyethylene naphthalate having an imide skeleton in the present invention is substantially a linear structure, unless the effect of the present invention is impaired, for example, 2 mol% or less, preferably 1 mol% or less based on all acid components. A polycarboxylic acid or polyhydroxy compound having three or more functional groups, for example, trimellitic acid or pentaerythritol may be copolymerized within the range of mol% or less.

The imide skeleton-containing polyethylene naphthalate of the present invention may contain a lubricant, a pigment, a dye,
Additives such as antioxidants, light stabilizers, heat stabilizers, light-blocking agents, matting agents, etc. can be added.

In the present invention, the delamination resistance is as follows:
It is expressed using a fold delamination whitening ratio described later as an index. The fold delamination whitening ratio is defined as a ratio of the length of the whitened portion generated when the film is bent to the entire length of the folded portion of the film.

The biaxially oriented film obtained from the copolymerized polyethylene naphthalate of the present invention preferably has a delamination resistance of 10% or less, which is represented by a fold delamination whitening ratio described later.

In producing the imide skeleton-containing polyethylene naphthalate of the present invention, a dicarboxylic acid component containing the above-mentioned naphthalenedicarboxylic acid and / or a lower alkyl ester thereof as a main component, and a glycol component containing ethylene glycol as a main component. And a bistrimellitic imide component represented by the above general formula as a copolymerization component may be subjected to a polycondensation reaction.A preferred method is a transesterification reaction of a lower alkyl ester of naphthalenedicarboxylic acid and ethylene glycol. After completion of the transesterification reaction, a method of adding a bistrimellitimide component and then subjecting the resulting reaction product to polycondensation can be mentioned.

Examples of the lower alkyl ester of naphthalenedicarboxylic acid include dimethyl ester, diethyl ester and dipropyl ester.
Among them, dimethyl ester is preferred.

In order to produce the film comprising the imide skeleton-containing polyethylene naphthalate of the present invention, any of the conventionally known film forming methods can be employed. For example, the imide skeleton-containing polyethylene naphthalate is melted and formed into a sheet. It can be manufactured by extruding and cooling with a cooling drum to obtain an unstretched film, and then stretching the unstretched film biaxially, heat setting, and, if necessary, heat-relaxing. At that time, the surface properties, density, and properties of the heat shrinkage of the film vary depending on the stretching conditions and other manufacturing conditions, so that the conditions may be appropriately selected as needed. When imide skeleton is used, polyethylene naphthalate having an imide skeleton is melted at a temperature of (Tm + 10) ° C. to (Tm + 30) ° C. (where Tm represents the melting point of the polyethylene naphthalate having an imide skeleton), extruded, and extruded. After stretching, the unstretched film is stretched in a uniaxial direction (longitudinal direction or transverse direction) at a temperature of (Tg-10) ° C. to (Tg + 50) ° C. at a stretch ratio of 2 to 5 times, and then stretched as described above. (Tg) ° C. to (Tg + 50) ° C. in a direction perpendicular to the direction (in the case where the first stage stretching is longitudinal, the second stage is horizontal).
Stretching may be performed at a draw ratio of up to 5 times.

Thereafter, the temperature is further increased from (Tg + 60) ° C. to (Tg +
120) It is preferable to heat-fix the film at a temperature of 0.2 ° C. for 0.2 to 20 seconds. When the fixing temperature and time are within the above-mentioned ranges, the film exhibits higher delamination resistance and also has improved anti-curl properties. And a highly transparent film can be obtained.

The method for producing the fiber comprising the imide skeleton-containing polyethylene naphthalate of the present invention is not particularly limited, and any conventionally known method for producing ordinary polyester fibers can be employed. A method of winding an undrawn yarn and drawing separately, a method of continuously drawing an undrawn yarn without winding it once, 5
Melt spinning at a spinning speed of 2,000 m / min or more and omitting the drawing process; after melt spinning, after cooling and solidifying the undrawn yarn in a coagulation bath, contact heating in a heating medium or a heating roller, or Any method such as stretching with a contact heater can be adopted.

When performing melt spinning, a hydrolysis inhibitor such as carbodiimide and a chain extender such as bisoxazoline may be added.

[0030]

The reason why the present invention exerts its effects is not clear, but by introducing a specific bistrimellitimide compound between polyethylene naphthalate molecular chains,
A film having improved delamination resistance and improved fatigue resistance while controlling the plane orientation of polyethylene naphthalate chains and retaining the excellent properties of regular polyethylene naphthalate It is presumed that fibers having properties can be obtained.

[0031]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited by these examples. In addition, each characteristic value in an Example was measured by the following method. In the examples, "parts" means "parts by weight".
Represents

(1) Intrinsic viscosity: Measured in a mixed solvent of phenol / tetrachloroethane (weight ratio 6: 4) at 35 ° C. according to a conventional method.

(2) Diethylene glycol content: The sample polymer was decomposed using hydrazine hydrate, and the content was measured by a conventional method using gas chromatography (type 263-70, manufactured by Hitachi, Ltd.).

(3) Crease Delamination Whitening Ratio (Film Delamination Resistance): A film sample was cut out to a size of 80 × 80 mm square, folded lightly by hand and sandwiched between a pair of flat metal plates. Thereafter, pressing was performed for 20 seconds at a predetermined pressure P1 (kg / cm ² G) by a press machine. After pressing, the folded film sample was spread to its original state, again sandwiched between the metal plates, and pressed at a pressure P1 (kg / cm ^2).
G) for 20 seconds. Then, the film sample was taken out and the length of the whitened portion (m
m) was measured and totaled.

Each new film sample was used, and the press pressure P1 was 1, 2, 3, 4, 5,
6 (kg / cm ² G), the above measurement was repeated, and the average value of the total length (mm) of the whitened portion at each pressing pressure was calculated as the total length of the fold (80 m
The percentage (%) of the film in (m) was defined as the fold delamination whitening ratio (%), and this value was used as an index indicating the difficulty of delamination (delamination resistance) of the film.

(4) Strong elongation and knot strength (fiber): Strength: Measured according to the method described in JIS L1070 5.1.1. Elongation: Measured according to the method described in JIS L1070 5.1.1. Knot strength: Measured according to the method described in JIS L1070 5.2.1.

(5) Young's modulus (film): A sample film having a width of 10 mm was placed in a tensile tester and the distance between chucks was set to 10
Both ends were fixed so as to be 0 mm, and a tensile test was performed at a tensile speed of 10 mm / min under the conditions of 23 ° C. and 50% RH. In this measurement, the Young's modulus in the machine direction (MD) and (TD) were measured using a new sample.

REFERENCE EXAMPLE 1 N, N'-hexamethylenebis (trimellitimide)
Synthesis of 58.1 g (0.5 mol) of hexamethylenediamine in N-methyl-2-pyrrolidone (hereinafter referred to as NMP) in a 1 L flask equipped with a reflux condenser, a water content receiver, a thermometer and a stirrer. 8) in 600 ml
Heat to 0 ° C to dissolve, then trimellitic anhydride 1
Dissolution was performed while gradually adding 94 g (1.01 mol) over 20 minutes. 30 after the end of the addition of trimellitic anhydride
And then add 400 ml of xylene for 160 minutes.
Reflux at 2 ° C. for 2 hours. After confirming that 18 ml or more of water had been collected in the water content measuring receiver, the temperature was increased to 190 ° C. to remove xylene.

After the solution was returned to room temperature, it was transferred to a 2 L beaker, and methanol was gradually added. When crystals began to appear, the beaker was cooled with ice to precipitate crystals, followed by filtration. The filtrate was thoroughly washed with methanol, and dried under reduced pressure at 120 ° C. for 2 hours to obtain a white powder having a melting point of 316 ° C.

Reference Example 2 The same operation as in Reference Example 1 was carried out except that 30.1 g (0.5 mol) of ethylenediamine was used instead of 58.1 g (0.5 mol) of hexamethylenediamine.

Reference Example 3 The same operation was performed as in Reference Example 1, except that 100.2 g (0.5 mol) of dodecamethylenediamine was used instead of 58.1 g (0.5 mol) of hexamethylenediamine. Thus, a white powder having a melting point of 224 ° C. was obtained.

Reference Example 4 In Example 1, 100.1 g of 3,4'-diaminodiphenyl ether was used instead of 58.1 g (0.5 mol) of hexamethylenediamine.
(0.5 mol) to obtain a white powder having a melting point of 365 ° C.

Example 1 Polymerization reaction: 99 parts of dimethyl naphthalene-2,6-dicarboxylate and 67 parts of ethylene glycol were used according to a conventional method using 0.03 part of manganese acetate tetrahydrate as a transesterification catalyst. After the transesterification reaction, 0.023 parts of trimethyl phosphate was added to substantially terminate the transesterification reaction.

Then, 0.024 parts of antimony trioxide,
N, N'-hexamethylenebis (trimellitimide)
1.90 parts (1 mol% based on the total amount of all dicarboxylic acid components) were added, followed by a polycondensation reaction under a high temperature and high vacuum in a conventional manner to give an intrinsic viscosity of 0.62 dl / g and a diethylene glycol copolymerization amount of 1 0.3 mol% of an imide skeleton-containing polyethylene naphthalate was obtained.

Formation of fiber: The pellet of the polyethylene naphthalate containing an imide skeleton was dried at 180 ° C. for 3 hours, and then dried using a die having a hole diameter of 0.27 mm and 6 holes.
Melt spinning was performed at 0 ° C., and the spinning speed was 400 m / min. The undrawn yarn was drawn 6-fold on a supply roller heated to 150 ° C., and subsequently subjected to a constant-length heat treatment on a hot plate heated to 240 ° C. to obtain a drawn heat-treated yarn of 70 de / 6 fill. Table 1 shows the properties of the obtained fibers.

Formation of film: A pellet of imide skeleton-containing polyethylene naphthalate obtained by the polymerization reaction was dried at 180 ° C. for 3 hours, fed to an extruder popper, melted at a melting temperature of 300 ° C., and cut into a 1 mm slit. It was extruded through a die onto a rotating cooling drum having a surface temperature of 40 ° C. to obtain an unstretched film. The unstretched film thus obtained was preheated at 120 ° C., further heated by a 900 ° C. IR heater from 15 mm above between low-speed and high-speed rolls, and stretched 3.0 times in the longitudinal direction. Subsequently, it was supplied to a tenter and stretched 3.3 times in the transverse direction at 140 ° C. The obtained biaxially oriented film was heat-set at 210 ° C. for 5 seconds to obtain a 25 μm-thick polyethylene naphthalate film having an imide skeleton. Table 1 shows the characteristics of the obtained film.
Shown in

Example 2 In Example 1, the copolymerization amount of dimethyl naphthalene-2,6-dicarboxylate and N, N'-hexamethylenebis (trimellitimide) was changed as shown in Table 1. Other than the above, the same operation was performed. Table 1 shows the properties of the obtained fiber and film.

[Embodiment 3] In the first embodiment, N, N '
-Hexamethylenebis (trimerimido) 1.90
Part, N, N ′ obtained by the operation of Reference Example 2
-The same operation was performed except that 1.67 parts of ethylenebis (trimellitimide) was used. Table 1 shows the properties of the obtained fiber and film.

[Fourth Embodiment] In the first embodiment, N, N '
-Hexamethylenebis (trimerimido) 1.90
N, N ′ obtained by the operation of Reference Example 3 in place of
-Dodecamethylene bis (trimeritimide) 2.24
The same operation was performed except that the part was used. Table 1 shows the properties of the obtained fiber and film.

[Comparative Example 1] In Example 1, N, N '
-The same operation was performed except that hexamethylenebis (trimellitimide) was not added. Table 1 shows the properties of the obtained fiber and film.

Comparative Example 2 In Example 1, the copolymerization amount of dimethyl naphthalene-2,6-dicarboxylate and N, N'-hexamethylenebis (trimellitimide) was changed to the amount shown in Table 1. Other than the above, the same operation was performed.
Table 1 shows the properties of the obtained fiber and film.

Comparative Example 3 In Example 1, N, N ′
-Hexamethylenebis (trimerimido) 1.90
3,4′- obtained by the operation of Reference Example 4 in place of
Diphenyl ether bis (trimellitimide) 2.2
The same operation was performed except that four parts were used. Table 1 shows the properties of the obtained fiber and film.

Comparative Example 4 The same operation was performed as in Example 1, except that 2 parts of diethylene glycol was added. The content of diethylene glycol present in the polyester copolymer was 4.1 mol%. Table 1 shows the properties of the obtained fiber and film.

[0054]

[Table 1]

As is clear from Table 1, it is understood that the imide skeleton-containing polyethylene naphthalate of the present invention has high knot strength and delamination resistance while maintaining strength and Young's modulus.

[0056]

The polyethylene naphthalate having an imide skeleton according to the present invention retains various excellent properties of a regular polyethylene naphthalate polymer, has a delamination resistance when formed into a film, and has a low Fatigue resistance is improved, and the film can be suitably used for photographic films, magnetic films and insulating films, and the fibers can be suitably used for tire cords, canvases and the like.

Claims (3)

[Claims] 1. An imide skeleton-containing polyethylene naphthalate obtained by copolymerizing a naphthalenedicarboxylic acid as a main dicarboxylic acid component, ethylene glycol as a main glycol component and a bistrimellitic imide component, wherein the bistrimellitic component has the following structural formula The bistrimellitic imide component represented by 1) is contained in an amount of 0.3 to 5 mol% based on all dicarboxylic acid components constituting the imide skeleton-containing polyethylene naphthalate, and the content of the diethylene glycol component is imide skeleton-containing polyethylene naphthalate. An imide skeleton-containing polyethylene naphthalate, which is contained in an amount of 3 mol% or less based on all glycol components constituting phthalate. Embedded image (In the formula, X represents a saturated aliphatic chain having 2 to 16 carbon atoms.) 2. A film comprising the imide skeleton-containing polyethylene naphthalate according to claim 1. 3. A fiber comprising the imide skeleton-containing polyethylene naphthalate according to claim 1.