JPH05295132A - Sheet and thermoformed article - Google Patents

Abstract

PURPOSE:To obtain a sheet of a polyester resin composition good in thermoformability and applicable under a wide variety of conditions, and a thermoformed article produced by thermoforming the sheet. CONSTITUTION:A composition comprising 97-65 pts.wt. polyester having main recurring units of ethylene terephthalate, 1-25 pts.wt. modified polypropylene prepd. by copolymn. of ethylene with maleic anhydride, and 2-10 pts.wt. fine inorg. particles (e.g. graphite, magnesium silicate or talc) is formed into a sheet, which is then thermoformed to obtain a thermoformed article.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a film or sheet (hereinafter simply referred to as a sheet) obtained by molding a composition comprising polyethylene terephthalate polyester, modified polypropylene and inorganic fine particles, and a thermoforming process for this sheet. It relates to a thermoformed product obtained by applying. The sheet of the present invention is extremely excellent in thermoformability.

[0002]

2. Description of the Related Art A sheet containing a polyester (A) containing ethylene terephthalate as a main repeating unit (hereinafter sometimes abbreviated as polyester (A)) as a main constituent is well known (for example, JP-A-59-59). 62660, JP-A-2-127437). However, the sheets obtained by these conventional techniques are not necessarily wide in the range of conditions in which they can be thermoformed.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to expand the range of conditions in which a sheet containing a polyester (A) as a main constituent can be thermoformed, and as a result, a thermoformed article having excellent heat resistance. Is what you are trying to get.

[0004]

The present inventors have found that 97 to 65 parts by weight of a polyester (A) containing ethylene terephthalate as a main repeating unit, and polypropylene (B) 1 to which ethylene and maleic anhydride are copolymerized 25
It is possible to broadly broaden the range of thermoformable conditions of a sheet using a resin composition containing 2 parts by weight of inorganic particles (C) and 2 parts by weight of inorganic fine particles (C). It was found that a thermoformed product having excellent heat resistance can be obtained by using it.

The present invention will be described in detail below.

The polyester (A) used in the present invention is a polyester containing terephthalic acid as a main acid component and ethylene glycol as a main glycol component, that is, all or most of repeating units (usually 90 mol% or more, preferably 95 mol%). % Or more) is a polyester composed of ethylene terephthalate.

Further, the polyester (A) can be copolymerized with the following components within the range not impairing the physical properties. That is, as the acid component, an aromatic dicarboxylic acid other than terephthalic acid, for example, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid,
Diphenylmethane dicarboxylic acid, diphenyl ketone dicarboxylic acid, diphenyl sulfide dicarboxylic acid, diphenyl sulfone dicarboxylic acid, aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, alicyclic dicarboxylic acid such as cyclohexanedicarboxylic acid, tetralindicarboxylic acid, decalin Dicarboxylic acid etc. are illustrated.

As the glycol component, butylene glycol, propylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyethylene glycol, bisphenol A, Catechol, resorcinol,
Examples thereof include hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, dihydroxydiphenylmethane, dihydroxydiphenyl ketone, dihydroxydiphenyl sulfide, dihydroxydiphenyl sulfone and the like.

Examples of the oxycarboxylic acid component include oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid and ω-hydroxycaproic acid.

Further, trifunctional or higher functional compounds such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid and pyromellitic acid may be copolymerized within a range in which the polyester does not substantially lose molding performance.

Such a polyester can be obtained by polycondensing terephthalic acid and / or a functional derivative thereof and ethylene glycol and / or a functional derivative thereof by a conventionally known aromatic polyester production method.
The concentration of terminal carboxyl groups of the polyester (A) used in the present invention is not particularly limited, but it is desirable that the concentration is low. The intrinsic viscosity of polyester (A) is 0.65
The above is preferable.

In the present invention, 2 to 25 parts by weight of a modified polypropylene (B) obtained by copolymerizing 97 to 65 parts by weight of an ethylene terephthalate polymer, which allows a small amount of modification, with ethylene and maleic anhydride, and 2 to 10 inorganic fine particles.
Parts by weight are melt-kneaded to form a sheet.

The copolymerization ratio of the modified polypropylene (B) is as follows: ethylene is 5 to 30 mol%, maleic anhydride is 0.5 to 5 mol%, and the Vicat softening point is 70 to 85 ° C. , Density 0.88-0.92g / c
A polypropylene having a m ³ and a melt flow rate (hereinafter sometimes abbreviated as MFR) of 4 to 8 is extremely finely dispersed in the polyester (A), and thus modified polypropylene (B)
Has a large effect of improving toughness.

The inorganic fine particles (C) used in the present invention include graphite, carbon black, magnesium oxide, calcium silicate, magnesium silicate, talc, kaolin,
Calcium carbonate, magnesium carbonate, sodium carbonate,
At least one selected from the group consisting of potassium carbonate, zinc oxide, alumina, barium sulfate and calcium sulfate. The inorganic fine particles have the effects of promoting crystallization of polyester (A) and increasing the rigidity of the sheet.

The amount of the inorganic fine particles added is 2 to 10 parts by weight, preferably 3 to 7 parts by weight.

The particle size is not particularly limited, but is 0.02 to 5
μm is preferred.

The composition constituting the sheet of the present invention may be surface-treated with an epoxy compound, a silane compound, an isocyanate compound, a titanate compound or the like, if necessary.

The polyester resin composition of the present invention further imparts desired properties depending on its purpose, so that other additives such as a colorant, an ultraviolet absorber, and a release agent are added to the extent that the physical properties thereof are not significantly impaired. An antistatic agent or the like can be added.

Next, a method for forming the composition of the sheet of the present invention into a sheet will be described.

The sheet of the present invention is supplied with the composition or / and components constituting the present invention to a generally used known equipment and method, that is, an extruder, extruded through a slit-shaped die, and cast on a casting drum. It is obtained by cooling and solidifying to form a sheet.

The method of supplying the composition and / or components of the present invention to an extruder is, for example, after mixing the components, melt-kneading and extruding with an extruder to prepare pellets,
After that, a method of making a sheet using this pellet,
Once the pellets having different compositions are prepared, the pellets are mixed in a predetermined amount and supplied to an extruder for making a sheet, and a method for obtaining a sheet, 1 or 2 of each component is added to the extruder for making a sheet.
There is a method of directly charging the above, and any method can be used. In addition to the above, the sheet and / or the thermoformed body once prepared and / or the flakes formed by crushing the die-cutting scraps generated during the thermoforming are also described above.
It can also be used as one of the materials or components in the sheeting of.

Further, it is preferable that a part of the components be made into fine powder and mixed with the other components to be added in order to uniformly mix these components. In addition, it is preferable to dry the pellets and components before feeding them to the extruder.

As a method of drying the pellets, for example, a temperature in the range of 100 ° C. or higher and a temperature of 30 ° C. lower than the melting point of polyester, more preferably a temperature in the range of 120 ° C. or higher and 50 ° C. lower than the melting point of polyester. A method of drying by using dehumidified heated air or nitrogen gas or the like as needed, a method of drying by using electromagnetic waves, and the like are applied.

Further, when casting, static electricity is applied to the sheet so that the sheet is brought into close contact with the cooling drum, whereby a sheet having excellent flatness can be obtained.

The sheet of the present invention obtained as described above may be cut and used as it is without being subjected to thermoforming, but thermoforming this sheet can be utilized for various purposes.

The sheet obtained as described above is preheated by an infrared heater, a hot plate heater, hot air or the like, and then subjected to thermoforming.

As a thermoforming method, a female mold, or a female mold and a male mold or a plug is used, and for example, vacuum molding, pressure molding or vacuum pressure molding is adopted. Upon molding, the female mold, male mold and plug can be heated.

[0028]

Application of Thermoformed Article of the Present Invention The sheet obtained by the present invention and the thermoformed article comprising the sheet are used as packaging materials for foods and industrial products, as well as for electric and electronic equipment parts and OA equipment. It is usefully used for parts, mechanical parts such as electric tools, insulating materials for motors, base materials for cards, building materials, etc.

[0029]

EXAMPLES AND COMPARATIVE EXAMPLES The present invention will be described in detail below with reference to Examples and Comparative Examples. The components used in Examples and Comparative Examples had the following characteristics.

As the polyethylene terephthalate, one having an intrinsic viscosity of 0.80 measured at 35 ° C. with orthochlorophenol as a solvent is used, and as polypropylene obtained by copolymerizing ethylene and maleic anhydride, Mitsui Petrochemical Co., Ltd. Modic P-300F manufactured by Mitsui Chemicals, Inc. was used. Further, as the inorganic fine particles, talc and PKNN manufactured by Hayashi Kasei Co., Ltd.
And Kaolin and Translink 444 manufactured by Engelhard were used.

Moldability is FC-1APA- manufactured by Asano Laboratory.
Evaluation was performed by mounting a tray molding die on a W-type vacuum pressure air molding machine and observing the molding state.

The size of the tray molding die is the opening 13
The size is 5 mm x 65 mm, the bottom is 125 mm x 55 mm, and the depth is 20 mm, and the corner of the bottom is 10 mmR, forming a spherical arc.

Polyethylene terephthalate was dried at 150 ° C. for 3 hours and the other components were not particularly dried, and the composition ratios of the respective Examples and Comparative Examples shown in Table 1 were applied to the extruder. It was charged and pelletized once.

Next, the pellets were dried at 150 ° C. for 3 hours, charged into an extruder for sheet production, melt-kneaded and passed through a die to form a sheet having a thickness of 0.3 mm.

Subsequently, the mold was set to a predetermined temperature, the sheet was preheated by using an infrared heater for a predetermined time and then thermoformed, and the molding state was observed. The results are summarized in Table 1.

[0036]

[Table 1]

Further, in each of the examples, hot water of about 95 ° C. was poured into the sample in a good molded state, but in all cases, the tray shape did not change and excellent heat resistance was exhibited.

[0038]

Industrial Applicability According to the present invention, a sheet having excellent moldability can be provided. The sheet and the thermoformed product are used as a packaging material for foods and industrial products, as well as electric / electronic parts, OA equipment parts, It is useful for mechanical parts such as electric tools or insulating materials for motors, base materials for cards, building materials and the like.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area C08L 23:08) 7107-4J 67:02

Claims (2)

[Claims] 1. A polyester (A) containing 97 to 65 parts by weight of ethylene terephthalate as a main repeating unit, 1 to 25 parts by weight of a modified polypropylene (B) copolymerized with ethylene and maleic anhydride, and inorganic fine particles (C).
A sheet formed by molding a resin composition comprising 2 to 10 parts by weight. (However, inorganic fine particles are a group of graphite, carbon black, magnesium oxide, calcium silicate, magnesium silicate, talc, kaolin, calcium carbonate, magnesium carbonate, sodium carbonate, potassium carbonate, zinc oxide, alumina, barium sulfate and calcium sulfate. (At least one kind selected from the following.) 2. A thermoformed product obtained by thermoforming the sheet according to claim 1.