JP2001310992A - Polyester resin sheet and moldings thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester resin sheet and moldings thereof which are suitably used for packaging or transporting of electronic equipment parts. SOLUTION: The resin composition comprises a polyester-based resin (a) having an ethylene terephthalate unit as the main components and a polyolefin- based resin and/or a polyamide-based resin (b), and the ratio of component (b) to the amount of sum totals of components (a) and (b) is 0.1 ppb-10 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin sheet and a molded product thereof, and more particularly, to a polyester resin sheet having enhanced conductivity and a molded product thereof. The molded article of the present invention is particularly useful as a tray or container for packaging or transferring electronic components.

[0002]

2. Description of the Related Art Vacuum forming trays, embossed carrier tapes and the like are conventionally known as packaging forms for ICs and electronic device parts including ICs. If the surface resistivity of the plastic sheet, which is the raw material of the vacuum forming tray or the embossed carrier tape, is high, it is likely to be charged and the function of the IC is likely to be broken.

Therefore, conventionally, (1) a method of applying an antistatic agent to the surface of a packaging container, (2) a method of applying a conductive paint to the surface of the packaging container, and (3) a method of applying an antistatic agent to a molding resin. A method of kneading a conductive filler such as carbon black has been proposed.

However, in the method (1), the antistatic agent flows out due to moisture during long use, the antistatic agent is removed due to friction of the surface, and the surface resistivity becomes uneven due to uneven coating. There are drawbacks such as the occurrence of properties.
In the method (2), the target sheet is limited in terms of the adhesion of the conductive paint, coating unevenness is likely to occur, and the conductive layer is peeled off due to weak surface friction, and the antistatic property is lost. There are disadvantages. In the method (3) using an antistatic agent, if the amount of the antistatic agent is large, the antistatic agent easily bleeds out on the surface, and molding processing becomes difficult. Further, there is a drawback such that a satisfactory antistatic effect cannot be obtained with a small amount of addition. In the method (3) using a conductive filler, a large amount of the conductive filler is required, so that the mechanical strength and impact strength of the obtained sheet are remarkably reduced. There are drawbacks such as a decrease in secondary formability such as plate forming. As described above, none of the sheets obtained by the above method is satisfactory for packaging ICs or electronic device parts including ICs.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to overcome the above-mentioned various drawbacks and to provide a polyester system suitable for packaging or transporting electronic equipment parts. A resin sheet and a molded article thereof are provided.

[0006]

That is, the first aspect of the present invention is as follows.
The gist of the invention is that it contains a polyester resin (a) having an ethylene terephthalate unit as a main component and a polyolefin resin and / or a polyamide resin (b), and a component (a) based on the total amount of the components (a) and (b). (b) a polyester resin sheet comprising a resin composition having a ratio of 0.1 ppb to 10% by weight.

A second aspect of the present invention resides in a molded product obtained by thermoforming the above-mentioned polyester resin sheet at a drawing ratio of 0.2 to 2.0.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The polyester resin sheet of the present invention comprises a resin composition containing a polyester resin (a) and a polyolefin resin and / or a polyamide resin (b).

The polyester resin used as the component (a) in the present invention is typically a polyethylene terephthalate resin comprising at least 80 mol% of ethylene terephthalate units. Polyester resin having less than 80 mol% of ethylene terephthalate unit is
Molded articles tend to have poor impact resistance and mechanical properties.

As components other than ethylene terephthalate, for example, isophthalic acid, naphthalene dicarboxylic acid,
Aromatic dicarboxylic acids such as diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenyl sulfone dicarboxylic acid; alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid; adipic acid, sebacic acid, and azelaic acid And the like, and one or more kinds of aliphatic dicarboxylic acids such as P-β-hydroxyethoxybenzoic acid.

[0011] Components other than ethylene glycol include:
For example, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, diethylene glycol, 1,1-cyclohexane dimethylol, 1,4 and 1,3-cyclohexane dimethylol, 2,2-bis ( 4′-β-hydroxyethoxyphenyl) propane,
One or more of bis (4′-β-hydroxyethoxyphenyl) sulfonic acid and the like can be mentioned.

In the present invention, the repeating structural unit 9
It is preferable to use a polyester resin in which 7 mol% or more is polyethylene terephthalate.

The above-mentioned polyester resins usually contain manganese, magnesium, cobalt, zinc, antimony, germanium, and the like derived from the catalyst used in the production thereof.
One or more kinds of metal elements such as titanium, phosphorus elements derived from stabilizers, and the like are contained. In the present invention, a polyester resin using antimony or germanium as a polycondensation catalyst is preferably used from the viewpoint of color tone and thermal stability.

The intrinsic viscosity of the polyester resin (hereinafter referred to as IV)
) Is usually 0.60 to 1.30 dl / g, preferably 0.65 to 1.10 dl / g. IV is 0.6
When it is less than 0 dl / g, the thermoformability at the time of producing a molded article is poor, and the mechanical properties of the obtained molded article, particularly the impact resistance, tend to be poor. Conversely, if the IV exceeds 1.30 dl / g, the viscosity tends to be high and extrusion molding tends to be difficult. The IV generally decreases when the polyester resin is melt-extruded into a sheet, but the IV does not substantially change when the sheet is thermoformed into a molded product. Accordingly, the IV of the sheet is substantially equal to the IV of the molded article obtained from the sheet.

The oligomer content of the polyester resin is defined as the content of the cyclic trimer which is the main component thereof.
It is usually at most 0.6% by weight, preferably at most 0.5% by weight. When the content of the cyclic trimer exceeds 0.6% by weight, for example, a casting roll stain or a mold stain may be caused at the time of sheet forming or sheeting.

In the present invention, a polyolefin resin and / or a polyamide resin is used as the component (b).

Examples of the polyolefin resin include those having 2 carbon atoms such as ethylene, propylene and butene-1.
About 8 to about 8 α-olefin homopolymers or copolymers of these α-olefins with other components. And other components for the copolymer are ethylene,
Α- having about 2 to 20 carbon atoms, such as propylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, and decene-1.
It is appropriately selected from the group of vinyl compounds such as olefin, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, and styrene.

Specific examples of the polyolefin resin include:
Low / medium / high density polyethylene etc. (branched or linear)
Of ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-4-methylpentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer Coalescence, ethylene-
Vinyl acetate copolymer, ethylene-acrylic acid copolymer,
Ethylene-methacrylic acid copolymer, ethylene-based resin such as ethylene-ethyl acrylate copolymer, propylene homopolymer, propylene-ethylene copolymer, propylene-based resin such as propylene-ethylene-butene-1 copolymer, Butenes such as butene-1 homopolymer, butene-1-ethylene copolymer and butene-1-propylene copolymer
Primary resins are exemplified.

Examples of the polyamide resin include lactam polymers such as butyrolactam, δ-valerolactam, ε-caprolactam, enantholactam, ω-laurolactam, 6-aminocaproic acid, 11-aminoundecanoic acid, Polymers of aminocarboxylic acids such as -aminododecanoic acid, and polycondensates of diamine units and dicarboxylic acid units.

The diamine unit includes, for example, hexamethylene diamine, nonamethylene diamine, decamethylene diamine, dodecamethylene diamine,
Undecamethylenediamine, 2,2,4- or 2,4
Aliphatic diamines such as 4-trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane)
Alicyclic diamines such as m- or p-xylylenediamine; and the above-mentioned dicarboxylic acid unit includes, for example, aliphatic dicarboxylic acids such as glutaric acid, adipic acid, suberic acid and sebacic acid. Acids, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid are used.

Specific examples of polyamide resins include, for example, nylon 4, nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610 and nylon 61.
1, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6/66, nylon 6/61
0, nylon 6/12, nylon 6 / 6T, nylon 6
I / 6T and the like.

The ratio of component (b) to the total amount of components (a) and (b) must be from 0.1 ppb to 10% by weight. When the proportion of the component (b) is less than 0.1 ppb, the effect of reducing the surface resistance of a sheet is not exhibited, and the sheet cannot be used for packaging or transporting electronic device parts. Conversely, when the proportion of the component (b) exceeds 10% by weight, the secondary formability such as vacuum forming, air pressure forming, hot plate forming and the like is deteriorated, and a container for packaging or transporting electronic device parts is used. Will not be satisfied. The proportion of component (b) is preferably from 0.1 ppm to 5% by weight
It is.

For molding the polyester resin, an extrusion cast molding machine connected to a die can be used according to a conventionally known sheeting method. Furthermore, it is also possible to form (co-extrusion) a multi-layer sheet of two or more layers with three or more layers using a sheet forming machine provided with two or more extruders.

For example, after the raw material resin is dried, it is put into an extruder, melted at 200 to 320 ° C., extruded into a sheet, brought into contact with a casting drum, and cooled and solidified. The extruder may be a single screw or a twin screw.

As a method of charging the raw material resin to the extruder, for example, a method of collectively charging a predetermined amount of the raw material resin into a main hopper attached to the extruder, a method of charging the raw material resin from a side feeder, and the like can be adopted.

The molding temperature is controlled as follows. That is, usually, the resin temperature in the cylinder of the extruder is 250 to
Cylinder, about 330 ° C, so that the resin temperature from the screw tip to the die outlet is about 240-320 ° C
Adjust the temperature of piping, T-die, etc. Note that the measurement of the resin temperature may be performed with a thermocouple attached to the area.

The sheet extruded from the die is preferably cooled quickly so as not to proceed with crystallization, and is usually cooled by a casting roll of an electrostatic contact type or a touch roll type. In this case, the surface temperature of the casting roll is usually 20 to 70 ° C, preferably 25 to 70 ° C.
It is controlled at 60 ° C.

In the above extruder, one or more extruders are provided in the cylinder part.
It is preferable to have two or more vent ports. When an extruder without a vent port is used, the raw material resin is dried to prevent hydrolysis of the raw material resin (polyester) in the cylinder, and the water content is usually 0.01% by weight or less, preferably Supply to the hopper after adjusting to 0.005% by weight or less. On the other hand, when an extruder having a vent port is used, since the inside of the cylinder is depressurized and the raw resin can be dried in the cylinder, the raw resin may be supplied without drying, and In addition, volatile impurities such as acetaldehyde contained in the raw material resin can be reduced in the cylinder.

The vent port is usually 200 mmHg or less,
Preferably 100 mmHg or less, more preferably 50 mmHg
Hereinafter, it is particularly preferably used by connecting to a reduced pressure system of 10 mmHg or less. When a vent port is used, it is preferable to use a twin-screw extruder because the efficiency in reducing volatile impurities is high. At this time, the screw of the twin-screw extruder may be any of an engagement type, a non-engagement type, and an incomplete engagement type.

The polyester-based resin sheet of the present invention is finally obtained by cutting both ends of the sheet with a trimming cutter after passing through a casting roll, and then winding it into a roll or cutting it into a panel. Both ends of the cut sheet may be recycled as a part of the sheet material of the present invention. When recycling, it is usually preferable to use after crushing with a crusher or the like.

The polyester resin sheet of the present invention includes:
Other additives and the like can be contained. For example, a fluorescent agent, an ultraviolet absorber, an antistatic agent, an anti-blocking agent, a flame retardant in order to obtain aesthetics, weather resistance, lubricity, antistatic properties, etc. of the sheet itself or a molded article obtained by further molding the sheet , A colorant or the like can be added or applied. As the addition or coating method, a known method can be adopted, and examples thereof include a method of using a master batch in which an additive is dispersed at a high concentration, and a method of dissolving or dispersing in a solvent for coating. Furthermore, various surface treatments for the purpose of preventing scratches on the surface, antistatic, and the like, and covering with a protective sheet may be performed.

The thickness of the polyester resin sheet of the present invention is usually 0.1 to 1 in the case of forming a molded product by thermoforming.
0 mm, preferably 0.20 to 10 mm, more preferably 0.50 to 10 mm. If the sheet is too thin, the final molded product will have poor impact resistance and mechanical properties,
The effect of improving heat resistance is reduced. Conversely, if the sheet is too thick, the deep drawability will be poor. The polyester resin sheet may be a laminate of two or more layers, or may have been subjected to various surface treatments.

The production of a thermoformed product from the polyester resin sheet of the present invention can be performed by any method commonly used in general thermoforming, such as air pressure molding, vacuum molding, plug assist pressure / vacuum molding, and blow molding. Is possible. As a preferred method, a polyester-based resin sheet is thermoformed into a thermoformed product having a thickness of 1/3 to 1/15 of the thickness of the sheet, and then the obtained molded product is subjected to tension (that is, (In a state of being closely adhered to a male mold by heat shrinkage).

In the thermoforming, in particular, a sheet temperature of 100 to 16
It is preferable to carry out at 0 ° C. by a plug assist method. Further, the molded article obtained by the thermoforming method can be usually arranged by the drawing ratio. Here, the drawing ratio is calculated as a value obtained by dividing the height (d) of the molded product by the short side of the mouth (the diameter in the case of a circle) (r1) as follows.

[0035]

## EQU1 ## Aperture ratio = d / r1

The polyester resin sheet of the present invention is formed into a tray or a container and is suitably used for packaging or transporting electronic parts.
It can also be used for forming partition boards, shelf boards, wall boards, hip boards, roof boards, signboards, and the like.

[0037]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. The measuring methods used in the following examples are as follows. Further, “parts” means “parts by weight”.

(1) Thickness (t) The thickness of the polyester resin sheet was measured every 10 mm, and the average value was defined as the thickness (t).

(2) Content of polyolefin resin and polyamide resin: About 15 mg of a sheet sample was dissolved in 0.7 ml of trifluoroacetic acid, and the above resin was quantified by NMR, and the content was calculated.

(3) Surface resistance measurement: 100 mm × 10
For a sample having a size of 0 mm, a surface resistance measuring device (H
EWLETT PACKARD HP4339A) was used to measure both the casting surface and the anti-casting surface in an environment of 23 ° C. and 50% humidity. And
The value of the sheet was compared with the value of the sheet only from polyethylene terephthalate obtained in the below-mentioned reference example, and a case where the surface resistance value (Ω / sq) was smaller than that (when conductivity was imparted) was indicated by ○.

(4) Thermoformed product evaluation method: 210 × 300
The sheet is cut into mm, heated to 160 ° C., using a female mold, the bottom diameter is 50 mm, and the mouth diameter is 60 m.
m, vacuum forming into a cup shape with round corners at a depth of 60 mm,
The appearance of the obtained five molded articles was visually observed, and judged based on the criteria shown in Table 1.

[0042]

[Table 1] ○: No problem as a product. Δ: There is some problem in appearance, and in some cases, it may not be a product. ×: Insufficient squeezing, wrinkles, breakage, etc., resulting in no product.

Example 1 Polyethylene terephthalate ("GM" manufactured by Mitsubishi Chemical Corporation)
500 ") 93 parts and polyethylene (Nippon Polychem Co., Ltd.)
(LJ845) was dried at 150 ° C. under vacuum for 4 hours, and extruded at 280 ° C. onto a stainless steel casting drum cooled to 30 ° C. by an extruder. Then, the sheet was pressed against a casting drum with a touch roll to obtain a sheet having a thickness of 0.5 mm. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Example 2 A sheet was obtained in the same manner as in Example 1 except that 99 parts of polyethylene terephthalate and 1 part of polyethylene were used. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Example 3 In Example 1, a raw material obtained by dry blending 99 parts of polyethylene terephthalate ("GM500" manufactured by Mitsubishi Chemical Corporation) and 1 part of nylon resin ("Novamid 1010" manufactured by Mitsubishi Engineering Plastics Co., Ltd.) A sheet was obtained in the same manner as in Example 1 except for using. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Example 4 In Example 1, polyethylene terephthalate 100
And a sheet was obtained in the same manner as in Example 1 except that 0.001 part of polyethylene and 0.001 part of polyethylene were used. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Example 5 In Example 1, the polyethylene terephthalate 100
And a sheet was obtained in the same manner as in Example 1, except that 0.0001 part of polyethylene and 0.0001 part of polyethylene were used. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Example 6 In Example 1, polyethylene terephthalate 100
And a sheet was obtained in the same manner as in Example 1 except that 0.0000002 parts of polyethylene were used. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Reference Example A sheet was obtained in the same manner as in Example 1 except that only polyethylene terephthalate was used.
Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

Comparative Example 1 A sheet was obtained in the same manner as in Example 1, except that 85 parts of polyethylene terephthalate and 15 parts of polyethylene were used. Table 2 shows the measurement results of the sheet surface resistance of the sheet and the evaluation results of the thermoformed product.

[0051]

[Table 2]

[0052]

The use of the polyester resin sheet according to the present invention makes it possible to provide a thermoformed product having a low surface resistance and good appearance.

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[Procedure amendment]

[Submission date] May 9, 2000 (200.5.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] Components other than terephthalic acid include, for example, aromatic dicarboxylic acids such as isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, hexahydroterephthalic acid, and the like. One or more of alicyclic dicarboxylic acids such as hexahydroisophthalic acid, aliphatic dicarboxylic acids such as adipic acid, sebacic acid and azelaic acid, and oxyacids such as P-β-hydroxyethoxybenzoic acid are exemplified.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) // (C08L 67/02 C08L 23:00) 23:00) (C08L 67/02 (C08L 67/02 77 : 00) 77:00) B29K 67:00 B29K 67:00 B65D 85/38 DF term (reference) 3E096 BA08 CA01 EA02X FA07 GA01 4F071 AA15 AA20 AA45 AA54 AF37 AH04 AH05 BA01 BB03 BB06 BC01 BC03 BC07 4F208 AA03 AAK24 AG01 AH58 AR20 MA01 MA02 MC04 MG11 MG22 MK20 4J002 BB032 BB052 BB062 BB072 BB082 BB122 BB142 BB152 BB172 CF041 CF061 CL012 CL032 CL052 GG01 GG02

Claims (4)

[Claims] 1. A polyester resin (a) containing an ethylene terephthalate unit as a main component and a polyolefin resin and / or a polyamide resin (b), and a component based on the total amount of the components (a) and (b) A polyester resin sheet comprising a resin composition having a proportion of (b) of 0.1 ppb to 10% by weight. 2. The polyester resin sheet according to claim 1, wherein the main component of the polyolefin resin comprises polyethylene and / or polypropylene. 3. A molded article obtained by thermoforming the polyester resin sheet according to claim 1 or 2 at a drawing ratio of 0.2 to 2.0. 4. The molded article according to claim 3, which is a tray or container for packaging or transporting electronic components.