JP2003128890A - Polyester resin composition for calendering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester resin composition for calendering, which does not cause drippings of the resin at the time of calendering process. SOLUTION: The polyester resin composition is characterized by having a storage elastic modulus of >=10<7> Pa at 25 deg.C at tensile mode and having a temperature range of >=60 deg.C where the storage elastic modulus is from 10<7> to 10<6> Pa. The above storage elastic modulus is achieved by adding 0.1 to 5 parts to 100 parts of a polyester.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calendering process for polyesters, which has good roll releasability and is particularly excellent in sheet removability during calendering, which is useful for industrial processing sheets and films. The present invention relates to a polyester resin composition.

[0002]

2. Description of the Related Art Generally, vinyl chloride type sheets (and films) are used in large amounts for various purposes because they are inexpensive and have excellent processability. Extrusion molding and calender molding are methods of processing this sheet, but the calender molding method has a better dimensional control of the thickness and width of the sheet than extrusion molding and is suitable for mass production. Has been adopted. Also, the finished vinyl chloride sheet is
It has sheet properties superior to other resins (transparency, flame retardancy, electrical insulation, durability, hardness controllability, etc.). However, due to the recent generation of dioxins during PVC incineration and the suspicion of environmental hormones in plasticizers, there are active moves to replace them with other resin materials. Among the alternative materials, polyester is one of the leading materials in terms of its physical properties and price, and various studies have been conducted.

However, a major problem in replacing vinyl chloride with polyester is its application to calender molding. Conventionally, extrusion molding has been frequently used for a polyester resin as a method for producing a sheet or a film because of its ease of processing. When the polyester resin is subjected to calendar processing, the adhesive force to the roll when it is thermoplasticized is relatively strong, and the polyester resin adheres to the roll during processing, which makes molding difficult. Therefore, in order to prevent the adherence to the roll, Japanese Patent Laid-Open No.
-343353, JP 2000-136294, JP 2
000-186191, JP-A-2000-302951,
As proposed in Japanese Patent Laid-Open No. 2001-64496,
Hydrocarbon type such as polyethylene wax, higher fatty acid type,
Attempts have been made to add various lubricants such as higher alcohol type, fatty acid amide type and ester type. By adding these lubricants, it will be possible to take them out without adhering to the roll, but as a further problem, resin sagging occurs due to the weight of the sheet before reaching the cooling roll of the next process, and a sheet with originally good dimensional accuracy is completed. It loses the properties of calendering.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a polyester resin composition for calendering which does not cause resin sagging during calendering.

[0005]

[Means for Solving the Problems] To achieve the above object,
The present inventors have made extensive studies and have proposed the following invention. That is, according to the present invention, the storage elastic modulus in the tensile mode at 25 ° C. is 10 ⁷ Pa or more, and the width of the temperature region showing the storage elastic modulus in the tensile mode from 10 ⁷ Pa to 10 ⁶ Pa is 60. A polyester resin composition for calendering, which is characterized by having a temperature of at least ° C. Especially from 100 parts of polyester to 0.1 part of polyisocyanate to 5 parts
It is a polyester resin composition for calendering in which the storage elastic modulus has been satisfied by containing a part. Preferably here the polyisocyanate is a dimer of tolylene diisocyanate.

In the present invention, the storage elastic modulus in the tensile mode is obtained by applying a sheet-like resin to a dynamic viscoelasticity measuring device. The size of the sample sheet is, for example, 15 mm in length (excluding the grip), 4 mm in width, and about 1 in thickness.
mm, the measurement condition is 2 Hz with the frequency fixed at 10 Hz.
Scanning is performed from −20 ° C. at a temperature rising rate of 0 ° C./min until measurement becomes impossible (maximum 250 ° C.). The method for preparing the sample sheet is not particularly specified, but the polyester resin is sandwiched between polyimide films and other heat-resistant films by a heat press or the like set to a temperature 10 ° C. or more higher than the softening point of the polyester resin, and pressed to obtain a smooth surface. You can get a sheet.

[0007] In the present invention, the tensile mode storage modulus of the polyester, at 25 ° C. in 10 ⁷ Pa or more, and it is essential to be 10 ⁷ Pa or less at a temperature lower than 180 ° C.. Furthermore, in the region below 250 ° C, 10 ⁷ P
The width of the temperature region showing from a to 10 ⁶ Pa is 60 ° C. or more. If it is less than 10 ⁷ Pa at 25 ° C, it is not suitable for the substitute use of a vinyl chloride sheet for the purpose of this patent. Further, by setting the width of the temperature region to be 60 ° C. or more, it is possible to maintain the viscoelasticity suitable for the fluctuation and distribution of the temperature control of the calender during calendering.

In the present invention, in order to obtain a polyester having a temperature range of 60 ° C. or higher, polyisocyanate is blended so as to be applicable to polyesters having various compositions, so as to provide appropriate chain extension and cross-linking moieties. It is preferable. Depending on the hydroxyl value of the polyester, by containing 0.1 to 5 parts of polyisocyanate per 100 parts of polyester, stable viscoelasticity can be obtained during calendering. The polyisocyanate may be compounded by reacting it in an extruder in advance, or may be directly supplied to a calendar roll together with polyester. The polyisocyanate to be used is not particularly limited, such as liquid / solid, aromatic / alicyclic / aliphatic, monomer / dimer / trimer / addition product to alcohol, etc. Therefore, a dimer of tolylene diisocyanate is preferable.

The dicarboxylic acid of the polyester of the present invention includes terephthalic acid, isophthalic acid, orthophthalic acid,
1,5-naphthalic acid, 2,6-naphthalic acid, 4,4'-
Aromatic dicarboxylic acids such as diphenyldicarboxylic acid, 2,2'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 1,
Aliphatic or alicyclic dicarboxylic acids such as 3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dimer acid and hydrogenated dimer acid can be used. As the polycarboxylic acid component, trimellitic anhydride, pyromellitic dianhydride, etc. can be used.

As the glycol component, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl- 1,3-
Propanediol, 1,5-pentanediol, 1,6
-Hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, tricyclodecanedimethanol, Neopentyl glycol hydroxypivalate ester, bisphenol A ethylene oxide adduct and propylene oxide adduct, hydrogenated bisphenol A ethylene oxide adduct and propylene oxide adduct, 1,
9-nonanediol, 2-methyloctanediol,
It is a diol such as 1,10-dodecanediol, 2-butyl-2-ethyl-1,3-propanediol or tricyclodecanedimethanol, or a polyhydric alcohol such as trimethylolpropane.

Among the above combinations of polyhydric carboxylic acid and polyhydric alcohol, terephthalic acid / isophthalic acid / ethylene glycol and terephthalic acid are preferable compositions which give physical properties and transparency similar to those of vinyl chloride sheet, processability and low cost. / Ethylene glycol / neopentyl glycol, terephthalic acid / ethylene glycol / cyclohexanedimethanol, terephthalic acid / isophthalic acid / ethylene glycol / 1,4-butanediol.

As a method for producing the polyester, a known method can be used. For example, after the esterification reaction of the above-mentioned dicarboxylic acid and diol components at 150 to 250 ° C., polycondensation at 230 to 300 ° C. under reduced pressure. By doing so, the target polyester can be obtained.

In the polyester resin composition for calendering of the present invention, in addition to polyester and polyisocyanate, a lubricant, an antioxidant, a plasticizer, a filler, an ultraviolet absorbent, A light stabilizer, a pigment, an antistatic agent, and an antibacterial agent can be added. For example, as a lubricant, a polyolefin wax or a metal salt of an organic phosphate ester, an organic phosphate ester, a higher fatty acid,
Examples thereof include higher fatty acid alcohols and higher fatty acid esters. In particular, in the case of achieving both releasability from a roll and transparency of a sheet, it is recommended to use a polyolefin wax and a metal salt of an organic phosphate ester together. As the antioxidant, for example, a phenol-based, phosphorus-based, or thioether-based antioxidant suppresses thermal oxidative deterioration of the polyester resin during calendar processing. Other examples include talc and mica as fillers, and acrylic oligomers and higher fatty acids as plasticizers.

The calendering polyester resin composition of the present invention is prepared by mixing the above components using a known mixer such as a Henschel mixer, and kneading the mixture with a Banbury mixer, a mixing roll, a warming roll and the like. Used for calendar processing.

[0015]

EXAMPLES The following examples are given to describe the present invention in more detail, but the present invention is not limited to the examples. The measured values described in the examples are measured by the following method.

Storage elastic modulus: A sample of the polyester resin composition was placed on a heat press adjusted to 200 ° C. via a polyimide film (“Kapton” manufactured by Toray DuPont) and kept at a pressure of ² N / mm ² for 20 seconds. Then 1 mm
A thick sheet sample was obtained. This is 15mm in length
(Excluding gripping margin), cut into a width of 4 mm, Dynamic Viscoelasticity Measuring Device "DVA-200" manufactured by IT Measurement and Control Co., Ltd.
The sample was set to and measured in the tensile mode. The measurement condition is that the frequency is fixed at 10 Hz and the temperature rise rate is 20 ° C./min until measurement becomes impossible (up to 250 ° C.).
(° C) scan.

Production Example of Polyester (A) 194 parts by weight of dimethyl terephthalate, 102 parts by weight of ethylene glycol, 57 parts by weight of neopentyl glycol, and tetra in a reactor equipped with a stirrer, a thermometer and a distilling cooler Add 0.1 parts by weight of butyl titanate to 1
The transesterification reaction was performed at 70 to 220 ° C. for 2 hours. After the transesterification reaction is completed, the reaction system is heated from 220 ° C to 255 ° C.
While increasing the temperature up to, slowly depressurize the system, 6
The pressure was adjusted to 5 Torr at 255 ° C. over 0 minutes. Then, the polycondensation reaction was further performed at 1 Torr or less for 30 minutes to obtain a sufficient molecular weight, and then the vacuum was broken in a nitrogen atmosphere. The obtained polyester was used as (A). This polyester (A)
The final composition of terephthalic acid // ethylene glycol / neopentyl glycol =
It was found to be 100/65/35 (molar ratio).

With respect to 100 parts of polyester (A),
Tridecyl poly (oxyethylene) phosphate zinc salt 1 part, styrene-modified polyethylene wax 0.5 part, high-density oxidized polyethylene wax 0.4 part, tetrakis [methylene-3- (3,5-di-tert-butyl-4)
-Hydroxyphenyl) propionate] methane 0.1
Parts, and 2 parts of a dimer of 2,4-tolylene diisocyanate (“Desmodur TT / G” manufactured by Bayer Co., Ltd.) were mixed in a beaker, and the mixture (1) was mixed with two pieces set at 180 ° C. Kneading was performed on a 6-inch chilled roll. The resin adhered to the chilled roll was occasionally peeled off with a spatula and mixed, and after mixing for a total of 5 minutes, the roll interval was set to 0.3 mm, and the sheet was taken out. At this time, the sheet was taken back smoothly without resin sagging. The sheet was transparent and had no color. On the other hand, when the mixture (2) except for the dimer of 2,4-tolylene diisocyanate is processed in the same manner and taken as a sheet, resin sagging occurs and a sheet having a uniform thickness can be obtained. could not.

The mixture (1) and (2) sampled from a chilled roll in advance was sandwiched between polyimide films by a heat press and pressed to a thickness of about 1
A sheet of mm was obtained. From this sheet, a strip having a length of 20 mm (15 mm excluding the grip) and a width of 4 mm was cut out, and the storage elastic modulus in the tensile mode was measured. As shown in FIG. 1, both have a storage elastic modulus of 10 ⁷ Pa or more at 25 ° C.,
The width of the temperature range in which the storage elastic modulus is from 10 ⁷ Pa to 10 ⁶ Pa is 90 ° C. for the mixture (1) and 45 ° C. for the mixture (2), and the mixture (1) falls within the scope of the present patent. , Mixture (2) is outside the scope of this patent.

[0020]

INDUSTRIAL APPLICABILITY As described above, the calendaring polyester resin composition of the present invention is excellent in roll releasability in calendering, and particularly excellent in sheet removability during calendering.

[Brief description of drawings]

FIG. 1 is a graph showing changes in storage elastic modulus of mixture (1) and mixture (2).

Continued front page    F-term (reference) 4J002 CF031 CF271 GA01                 4J034 BA03 DB03 DC50 DF01 HA01                       HA06 HA08 HC11 HC12 HC52                       QD00 SA01

Claims (3)

[Claims] 1. A storage elastic modulus in a tensile mode at 25 ° C. of 1 × 10 ⁷ Pa or more, and a storage elastic modulus in a tensile mode from 1 × 10 ⁷ Pa to 1 × 10 ⁶ Pa. Polyester resin composition for calendering, characterized in that the width of the temperature region is 60 ° C. or more 2. A polyester resin composition for calendering according to claim 1, which contains 0.1 to 5 parts of polyisocyanate per 100 parts of polyester. 3. The polyester resin composition for calendering according to claim 2, wherein the polyisocyanate in claim 2 is a dimer of tolylene diisocyanate.