JPS59126458A - Polyester molded article - Google Patents

Abstract

PURPOSE:To obtain a molded article having matte surface and excellent slippery, by thermally forming a composition composed of a polyethylene terephthalate, a polyarylate and a polyolefin, and matte-finishing the surface of the formed product. CONSTITUTION:A composition composed of (A) 51-95wt% of a thermoplastic polyester containing ethylene terephthalate as main recurring unit and having an intrinsic viscosity of >=0.50, (B) 2.5-30wt%, preferably 5-25wt% of a polyarylate and (C) 2.5-30wt%, preferably 5-30wt% of a polyolefin resin, is formed to a sheet, etc., and thermo-formed by compression molding, pressure forming, vacuum forming, etc. The compounding of the polyolefin is effective to improve the slippery by the organic lubricant effect and the development of matte surface caused by the incompatibility of the polyolefin and the polyester.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a polyester molded product, and more particularly to a polyester molded product obtained by sheet-forming a composition containing polyethylene terephthalate as a main component and then subjecting it to plastic processing such as deep drawing. It is.

[Technology background]

From resin sheets, compression molding and vacuum forming.

BACKGROUND OF THE INVENTION It is known to produce molded articles by thermoforming methods such as air pressure forming methods and has been produced on an industrial scale.

In general, these molded products have traditionally been used in application fields that do not require high mechanical or thermal performance, but recently, as the range of use of these molded products has expanded, they have been used in specific machines. Attempts are being made to apply it to parts.

For example, there is a new photographic system in which a disc-shaped photosensitive material is stored in a cartridge instead of the roll-shaped photographic film loaded in the conventional cartridge. Since the photosensitive material loaded in this cartridge slides inside the cartridge, the cartridge components that come into contact with the photosensitive material have smooth surfaces and are free from scratches (surfaces) on the photosensitive material. It must not form any marks (marks) and must have appropriate elasticity and mechanical strength. The first disk camera cartridge developed consisted of a hard plastic housing, a disk (photosensitive material), a slip sheet that made it slippery with the disk, and a shutter that exposed the photographing (single frame) part to light. , consists of auxiliary members for moving the disc by one frame. Then, excluding the housing and the disk, a relatively thin plastic sheet is pressed into a predetermined shape. The components of such cartridges are primarily light-blocking materials and are made from plastics containing black pigments. In addition, the component parts must have such slipperiness that they do not interfere with the rotation of the disk (in a normal cartridge that is photographed 1S times, it rotates approximately 1/15 times as the photographing is completed). Furthermore, it is essential that the components have appropriate elasticity to facilitate the movement of the disk. Assuming that these characteristics could be satisfied, carbon black was added to a polymer of cyclohexane dimetatool and terephthalic acid to form a sheet, and the surface of this sheet was made into a matte surface by embossing, and the sheet was then given a predetermined shape. Some are molded into molded products.

However, although such polyester is crystalline, its molecules are fixed in an amorphous state, and care must be taken to avoid crystallization during heating processing processes such as embossing and thermoforming. That is, if the sheet is embossing to obtain a matte surface and then thermoformed before heat-collecting molding in which the sheet does not crystallize, the matte surface will disappear due to thermal deformation due to heating and compression within the mold. In addition, if the matte surface remains after molding, if embossing is performed under conditions that cause crystallization to some extent, thermoforming will be difficult, mold traceability will be poor, and the yield of the product will be poor. First, there are problems such as variations in the physical properties of the product due to variations in the degree of crystallization.

By the way, it is technically complicated and subject to restrictions to form complex protrusions and depressions as a molded product by compression molding or deep drawing, and at the same time to make the entire surface matte. For example, surface matting tends to make it difficult to release the molded product from the mold, leading to problems such as low molding cycles and increased costs.

Therefore, the present inventor investigated a resin composition that has easy sliding properties without matting the surface of the mold, and found that a three-component composition of polyethylene/tere-7talate-borearyleate-boriorefine was used as a sheet with a matte surface. give, and
They discovered that it exhibits excellent slipperiness and completed the present invention.

[Structure of the invention]

That is, the present invention comprises 51 to 95% by weight of a thermoplastic polyester whose main repeating unit is ethylene terephthalate and whose intrinsic viscosity is at least 0.50, 2.5 to 30% by weight of a polyarylate, and 2.5% by weight of a polyolefin resin. ~
This is a polyester molded product obtained by thermoforming a composition containing 30% by weight.

To explain the present invention, the molded article of the present invention is obtained by deep drawing molding using compressed air or vacuum, or compression molding between molds, from a sheet made of a polyester resin composition. This resin composition is a mixture of a resin containing polyethylene terephthalate as a main component, polyarylate, and polyolefin in specific proportions.

The polyethylene terephthalate of the present invention is not only a homopolymer of polyethylene terephthalate, but also contains 75 or more moles of ethylene terephthalate units, preferably 90 moles or more of ethylene terephthalate units.
Substantially linear copolyesters containing more than 100 ml of copolyester are included. The third component constituting this copolyester is
For example, isophthalic acid, naphthalene-2,6-dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid.

diphenyl ether dicarboxylic acid, diphenyl sulfo/
Aromatic, alicyclic, aliphatic, etc., such as dicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, adipic acid, sepatic acid, azelaic acid, p-β-hydroxyethoxybenzoic acid, ε-oxycaproic acid, etc. Difunctional carboxylic acids, trimethylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, decamethylene glycol, diethylene glycol, triethylene glycol, l, 1-cyclohexane dimethylol, 1,4-cyclohexane dimethylol A/ , 2.2-bis(4'-β-hydroxyethoxyphenyl)propane.

Other glycols such as bis(4'-β-hydroxyethoxyphenyl)sulfone and the like may be mentioned. These are 1
A species or two or more species can be used.

Further, the polyethylene terephthalate may be copolymerized with a trifunctional or higher polyfunctional compound within a substantially linear range.

The polyethylene terephthalate used in the present invention must have an intrinsic viscosity of 0.50 or more. If the intrinsic viscosity is less than 0.50, the product after thermoforming will not have sufficient mechanical strength and will be subject to restrictions in use.

There is no particular upper limit to the intrinsic viscosity, but if it is extremely high,
Thermoforming tends to be difficult, and a preferable upper limit is approximately 1,40.

Next, the polyarylate blended into the polyethylene terephthalate of the present invention is an aromatic polyester containing aromatic dicarboxylic acid as the main acid component and bisphenol as the main diol component.

Examples of the aromatic dicarboxylic acid component constituting the polyarylate include terephthalic acid, isophthalic acid, naphthalene/dicarboxylic acid, diphenyldicarboxylic acid, diyenylsulfonedicarboxylic acid, and diphenylethanedicarboxylic acid. Among these, terephthalic acid, isophthalic acid, and mixtures thereof are preferable, particularly when the molar ratio of terephthalic acid and isophthalic acid is 1=9 to 9.
: Preferably used in combination within the range of 1. In addition, as bisphenol components, 2,2-bis(4'-hydroxyphenyl)propane, bis(4'-hydroxyphenyl)sulfone, l,1-bis(4'-hydroxyphenyl)ethane, 1,1-bis (4'-hydroxyphenyl)methane, 4,4'-dihydroxyphenyl ether, 4,4'-dihydroxyphenylthioether,
Examples include components such as 4.4'-dihydrocyphenylsulfide. Among these, especially 2゜2-
Bis(4'-hydroxyphenyl)furopane (bisphenol) is preferred. It is also possible to use a small proportion of aliphatic dicarboxylic acids (for example, adipic acid, sepatic acid, azelaic acid, etc.) as the acid component, and a small proportion of glycol (for example, ethylene glycol, tetramethylene glycol) as the diol component.

Hexamethylene glycol, 1,4-cyclohexanedimethylol, 2,2-bis(4'-hydroxyphenyl)furopane, bis(4'-hydroxyethoxyphenyl)sulfone, hydroquinone, resorcinol, etc. can also be used.

Another component of the composition constituting the molded article of the present invention is a polyolefin resin. Examples of polyolefin resins include polymers such as low-density polyethylene, medium-high density polyethylene, isotactic polypropylene, polybutene-1, and polymethylpentene, and copolymers such as ethylene-propylene copolymer and ethylene-vinyl acetate copolymer. In addition, ionomer resins can also be used.

The resin composition of the present invention may contain additives such as lubricants, antistatic agents, ultraviolet absorbers, and heat stabilizers within a range that does not change the essential properties of the polymer.

Oxidation stabilizer 1, coloring agent, etc. can be added.

Carbon black is used as a pigment when used in the disk camera cartridge mentioned above.

It is necessary to add a pigment colorant with a high light-shielding effect, such as titanium oxide.

In the molded article composition of the present invention, the polyethylene terephthalate polymer accounts for 51 to 95% by weight of the total polymer. Moreover, the polyarylate is required to account for 2.5 to 30% by weight, and the polyolefin resin also needs to account for 2.5 to 30% by weight.

The proportion of polyethylene terephthalate resin is 95%
% by weight, and the amount of polyarylate is 2.5% by weight
If it is less than that, the effect of improving heat resistance and impact resistance, the effect of elastic recovery in a low strain range, etc. obtained by the polyarylate will not be recognized.

In addition, if the polyethylene terephthalate content is less than 51% by weight and the polyarylate content exceeds 30% by weight, thermoformability will be impaired, the uniform blending of the entire composition will be impaired, and coloration (yellowing) may occur. . As a result, the mechanical strength is rather reduced, and the properties of the composition cannot be expressed.

Similarly, the content of polyethylene terephthalate resin is less than 51% by weight, and the blending ratio of polyolefin resin is 3% by weight.
A composition exceeding 0% by weight is unsuitable because the Young's modulus decreases and the surface of the molded article becomes considerably rough, resulting in poor mechanical performance even if slipperiness can be improved.

K, which brings polyarylates into composition molded products with modification effects such as high impact strength, heat resistance, and high Young's modulus, is at least 2.
．． It is necessary to account for 5% by weight. Moreover, if it exceeds 30% by weight, the moldability of the composition will be impaired and the effect of improving mechanical strength will be lost, as described above. Therefore, the proportion of polyarylate in the composition is 2.5 to 30% by weight, more preferably 5 to 25 it%.

The role of imparting the preferred slipperiness to the composition of the present invention is due to the polyolefin.

The polyolefin is 2.5 to 30% by weight, preferably 5 to 30% by weight.
It should be blended in a range of 30% by weight, and the higher the amount, the more the polyolefin can improve the slipperiness of the molded product due to its organic lubricant effect and the development of a matte surface due to its incompatibility with polyester. However, in order to maintain the mechanical performance of the composition, it is not preferable to add more than 30% by weight.

As for the method of blending the three components, any known means can be used and there are no particular restrictions. For example, a method may be adopted in which the three components of granular or powdered material are kneaded using a mixing means such as a type blender, tumbler, Henschel mixer, or super mixer.

However, it is preferable that the polyester and polyarylate be dried in advance to a moisture content of 0.1 or less, and care must be taken to prevent moisture absorption during the mixing process.
It is necessary to supply it to an extruder and melt-extrude it promptly.

Alternatively, each of the three components may be fed in fixed amounts to the extruder without using a mixer as described above.

A resin composition composed of polyethylene terephthalate, polyarylate, and polyolefin mixed by such a mixing method can be melt-extruded by connecting a T-die or an I-die to the extruder described above, and then rapidly cooled and formed into a sheet. Separately, in order to improve the extrusion stability and obtain a uniform sheet, a part or all of the -H3 component is extruded into a pellet-shaped molded product using the extruder, and if there are any missing components, they are added and mixed. The resin can be dried at a temperature of 250 to 330° C. for 20 minutes or more, preferably 1 hour or more, and then formed into a sheet using an extruder equipped with a T-die or an I-die at a resin temperature of 250 to 330°C.

The thickness of the sheet is usually 0.05-2 m, preferably 0.
．． It is 1 to 1 m.

The polyester sheet thus obtained is further molded into a desired shape by aging, such as compression molding, vacuum molding, pressure molding, or the like. Examples of the molding machine used for sheetel thermoforming include a press molding machine, a vacuum molding machine, a pressure molding machine, and a universal molding machine using a combination of vacuum and compressed air.

As described above, thermoforming in the present invention refers to melt-extruding a resin composition, cooling it if necessary, and forming it into a sheet-like product, and converting this sheet-like product into a molded product of a desired shape. This includes preheating the material to a temperature ranging from the glass transition temperature to the melting temperature and then performing any one of compression molding, pressure molding, or vacuum molding.

〔Effect of the invention〕

The molded article of the present invention has excellent heat resistance because polyarylate is added to the polyethylene terephthalate resin. Especially in the food packaging field, food is heated and filled inside the molded product (container) to give fluidity and/or to sterilize/disinfect it, so it is necessary to use molded products that can withstand thermal deformation. Highly practical. Furthermore, it is effective as packaging for products exposed to direct sunlight, and as covering members and functional members for products placed in high-temperature atmospheres.

The molded product of the present invention has the advantage that the molded product has such surface characteristics without being subjected to matte surface treatment.

The present invention will be explained below with reference to Examples.

Example 1 A pellet of polyethylene terephthalate with an intrinsic viscosity of 0.65 and a polyarylate with an intrinsic viscosity of 0.70 (copolymer of bisphenol A and terephthalic acid/inophthalic acid)
and high-density polyethylene with a melt index of 0.30 were mixed in the amounts shown in Table 1, dried, and fed to an extruder equipped with a T-die. Melt extrusion temperature is 290℃
The range was ±10°C, and conditions were set uniformly for a series of experiments. The thickness of the obtained sheets was 0.4. Met. This sheet was preheated to 100 to 150°C and compression molded using a male/female fitting type press mold controlled at 60°C. An ashtray-shaped molded product with a concave part of 5 cm was obtained.

This molded product was placed in a hot air circulation dryer and the temperature at which deformation began was checked, which is also listed in Table 1.

Table 1 (1) HDT indicates heat distortion temperature (°C).

(2) The coefficient of friction is determined by measuring static friction between the surface in contact with the cooling drum and the opposite surface during sheet formation.

The results in Table 1 show that adding polyolefin reduces the coefficient of friction and makes it easier to slip, and that mixing polyarylate and polyolefin increases the heat distortion temperature and improves the heat resistance of the molded product. understood.

Example 2 12 kg of the same polyester used in Example 1
and polyarylate 6 K9 were kneaded in a ■-type blender, and then dried at 150°C for 4 hours to reduce the moisture content to approximately 0.
05 weight'1t%. Add to this 2 to 9 polypropylene (melt index 0.4゜Inotaft City 9)
8%-) was added and supplied to the hopper of an extruder equipped with a T-die, and melt-extruded at 300°C to obtain a sheet with a thickness of O, SO.

This sheet full-pressure forming machine has a diameter of 70. , depth 80.
It was molded into a cup-shaped container. The molding conditions were a hot air temperature of 115°C and a heating time of 16 seconds.

The compressed air pressure j was 5 Kp/cn. The molded product had a heat resistance temperature of 91° C. and had excellent impact resistance.

Example 3 Polyethylene terephthalate 6.0119 obtained by solid phase polymerization with an intrinsic viscosity number of 0.98, polyarylate with an intrinsic viscosity of 0.70 (polycondensation of bisphenol A with equal amounts of terephthalic acid and inphthalic acid) x , sKy, medium density polyethylene2. OK9, carbon blank 0.40 with average particle size 1.5 μm mixed with 9 and colloidal silica (average secondary particle size 0.12 μm) 0, I I14 295
A sheet having a thickness of 0.8I was formed by melt extrusion at .degree.

This sheet was compression molded using a press to produce parts for a disc camera cartridge.

This part exhibited light-shielding properties and easy sliding properties, was able to faithfully form desired protrusions and depressions, and was easily released from the mold.

Patent Applicant: Teijin Co., Ltd. Procedural Amendment Date: February 1, 1980 To the Commissioner of the Patent Office 1 Indication of the Case Patent Application No. 1736 No. 1983 2 Name of the Invention Polyester Molded Article 3; Leap (V ↑,'1.:'I Applicant Jl
・IZ City Higashi 1) Minamihonmachi 1-chome 11 (300) Notindai Co., Ltd.! , Seiichi Ba (11th Specification, page 16, line 15, ``high density'' is corrected to ``low density.''

(2) The composition ratio of "polyether" in Table 1, page 17, 6 of the specification is corrected to "1-bolyarylate."

(3) In the same table, the composition ratio 1 "High density polyethylene" is corrected to "Low density polyethylene/".

that's all

Claims (1)

[Scope of Claims] (51-95% by weight of a thermoplastic polyester whose main repeating unit is ethylene terephthalate and has an intrinsic viscosity of at least 0.50 and 2.5-3% by weight of a polyarylate)
A polyester molded product obtained by thermoforming a composition containing 0% by weight and 2.5 to 30% by weight of a polyolefin resin. (2) The composition is formed into a sheet, and then compression molded,
The polyester molded article according to claim 1, which is obtained by aging either air pressure forming or vacuum forming.