JP2003001773A - Polyester laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester laminated sheet having high strength and excellent durability, capable of solving an environmental pollution problem at the time of disposal and having flexibility suitable for a flexible container. SOLUTION: The polyester laminated sheet is constituted by laminating a composition consisting of 60-90 wt.% of polyethylene terephthalate and 10-40 wt.% of polybutylene terephthalate on at least the single surface of net-like base cloth wherein stretched yarns comprising polyester are used as warp and weft yarns to be allowed to cross each other.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester laminated sheet, and more particularly to a laminated sheet containing polyethylene terephthalate as a main component, which has high strength and excellent durability and is suitable for flexible antennas, tent sheets and the like. .

[0002]

2. Description of the Related Art Conventionally, a flexible container is formed from a flexible material into a foldable bag body, and a hanging portion for lifting and an opening portion for injecting and discharging contents are provided in the bag body. Therefore, it has a characteristic that it can be repeatedly used for a long period of time, and when it is not filled with contents, it can be folded and stored small. As the raw material of this flexible container, a surface of a base cloth made of fibers such as polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate, polyamide such as nylon, polyvinyl chloride resin, ethylene-vinyl acetate copolymer, etc. A laminated sheet obtained by laminating the above resin is mainly used, and the bag is formed by sewing the original fabric with a sewing thread or joining the raw fabric with an adhesive or high-frequency welding.

In the above flexible container, since the raw material constituting the bag is made of a combination of different materials such as polyamide fiber / polyvinyl chloride or polyester fiber / ethylene-vinyl acetate copolymer, Although cleaning and reusing of
The actual situation is that old waste products are still incinerated or landfilled.

[0004]

However, in the case of landfilling a waste product of a flexible cotena laminated with polyvinyl chloride, a plasticizer compounded in polyvinyl chloride, for example, bleed of dioctyl phthalate or the like is used. There is a problem that the soil is polluted by this, and when incinerated, toxic gas is generated. On the other hand, it is desirable that the flexible container can be repeatedly used for as long as possible before being discarded, and therefore, as the characteristics of the flexible container, higher strength and higher durability are desired. Therefore, for flexible containers, a laminated sheet in which the same type of polyester is laminated on at least one side of a woven fabric made of polyester drawn yarn having high strength and high durability has been tried, but the obtained laminated sheet is hard. Therefore, there is a problem that the flexibility is poor and the above-mentioned characteristics of the flexible container cannot be satisfied. An object of the present invention is to provide a polyester laminated sheet having high strength and excellent durability, capable of solving the environmental pollution problem at the time of disposal, and having flexibility suitable for a flexible container.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that a specific ratio of polyethylene terephthalate and polybutylene terephthalate is provided on one side of a woven fabric made of polyester drawn yarn. By extrusion-laminating the composition of the above, it is flexible, and it is possible to obtain a laminated sheet suitable for a flexible container having excellent processability, and it is found that the above object is achieved,
The present invention has been completed. That is, the gist of the present invention is to use 60 to 90% by weight of polyethylene terephthalate and polybutylene terephthalate 10 on at least one surface of a net-shaped substrate obtained by using drawn yarns made of polyester for warp and weft.
A polyester laminated sheet obtained by laminating a resin composition of about 40% by weight.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The polyester used in the present invention is obtained by polycondensing a bifunctional component such as an aromatic dicarboxylic acid or a dialkyl ester thereof and a glycol component, and a typical example thereof is terephthalic acid as an acid component. Polyethylene terephthalate (PET) composed of ethylene glycol as a glycol component and polybutylene terephthalate (PB) using terephthalic acid as an acid component and tetramethylene glycol as a glycol component
T) and the like. The polyester may be a single homopolyester or a mixture of a plurality of homopolyesters or copolyesters. The copolyester may be isophthalic acid as a part of terephthalic acid in the aromatic dicarboxylic acid component. , Adipic acid, 2,6-naphthalenedicarboxylic acid, etc. may be copolymerized, and in the glycol component, a part of ethylene glycol is a copolymer of propylene glycol, tetramethylene glycol, diethylene glycol, etc. May be. The polyester preferably has a melting point of 200 to 260 ° C. Among these,
PET is preferred.

In the present invention, recycled polyester can be used as the polyester used for forming the coating layer by the drawn yarn formation or the extrusion laminating method. Regenerated polyester is usually used by crushing a polyethylene terephthalate beverage container (commonly called PET bottle) and re-pelletizing it, and in the re-pelletizing step, the intrinsic viscosity (η value) decreased due to water absorption, heat history, etc. It can be adjusted and used by solid-state polymerization. The recycled polyester can be used by appropriately mixing with the virgin polyester.

In the present invention, as the polyester for forming the drawn yarn, PBT is blended with the above-mentioned PET in order to prevent longitudinal cracks during flat yarn formation or to prevent weaving deterioration during weaving. preferable. PE
The compounding ratio of PBT to T is preferably in the range of 5 to 40% by weight. If the blending ratio is less than 5% by weight, it is difficult to achieve the above effects, and if it exceeds 40% by weight, the effect of adding PBT is not so great, and conversely the cost is significantly increased, which is not preferable.

The intrinsic viscosity (η value) of the polyester used in the present invention is in the range of 0.4 to 1.2 dl / g, preferably 0.5 to 1.0 dl / g, and further preferably. Is in the range of 0.7 to 0.9 dl / g. η value is 0.
If it is less than 4 dl / g, the tensile strength of the drawn yarn is lowered, and longitudinal cracks are likely to occur. On the other hand, if the η value exceeds 1.2 dl / g, the fluidity during melt extrusion is poor and the formability of the drawn yarn is lowered. It is not preferable.

In the present invention, the drawn yarn has only to have high tenacity due to the drawing effect using the above polyester, and as the form of the drawn yarn, any of monofilament, multifilament, flat yarn and the like can be used.
From the viewpoint of flexibility, multifilaments and flat yarns are preferred, and flat yarns are most preferred for flexible container applications. The method for producing the drawn yarn is not particularly limited, and a known technique may be adopted.

As a method for producing the above-mentioned flat yarn, for example, a raw material polyester is melt extruded from an extruder at 260 to 290 ° C., a film is formed by an inflation method or a T-die method, cooled and solidified, and then slit and stretched,
A relaxation heat treatment can be performed to obtain a flat yarn. As for the stretching, generally, two-stage stretching is preferable, and as the first-stage stretching, it is stretched 3 to 6 times at 60 to 120 ° C., and as the second stage stretching, it is stretched 2 to 3 times at 150 to 200 ° C., and then 18
Relaxation heat treatment is performed at 0 to 220 ° C. In addition, the raw material polyester is 150 to 16 by using a dryer before being charged into the extruder.
It is preferable to dry at 0 ° C. for 4 to 5 hours.

The drawn yarn has a fineness of 500 to 50.
In the range of 00 decitex (dt), preferably 100
It is in the range of 0 to 3000 dt. If the fineness is less than 500 dt, mechanical properties such as tensile strength as a base fabric will be insufficient,
On the other hand, if it exceeds 5000 dt, the flexibility is poor and the adhesion with the laminate layer is insufficient, which is not preferable.

Further, in the present invention, for the purpose of improving the longitudinal cracks of the drawn yarn, the molding processability, the lubricity, the surface appearance, etc. within the range that does not essentially impair the characteristics of the present invention, Inorganic fillers can be included in the composition.
As the inorganic filler, calcium carbonate, talc, silica, clay, hydrotalcite, etc. are preferably used. Of these, calcium carbonate is preferred. The amount of the inorganic filler compounded is in the range of 0.5 to 10% by weight, preferably 1 to 5% by weight, based on the composition. If the blending amount is less than 0.5% by weight, it becomes difficult to achieve the above object, while if it exceeds 5% by weight, the flexibility of the drawn yarn is lost and the yarn breaks, which is not desirable.

The net-like base fabric in the present invention is a base fabric obtained by intersecting drawn yarns made of the above polyester as warp yarns and weft yarns, and examples thereof include woven and knitted fabrics and non-woven fabrics.
As the woven / knitted fabric, the drawn yarn is used as warp / weft yarns to woven and knit to form a woven / knitted fabric. As the woven structure of the woven fabric, various shapes such as plain weave, twill weave, entangled weave and imitation weave are used, and the knitted fabric may be either flat knit or warp knit, specifically, tricot knit, Milanese knit, Russell Examples include editions. As the non-woven fabric, the weft yarn and the warp yarn of the drawn yarn are crossed, and the crossing contact portions are adhered to each other. The method of adhesion is not particularly limited, but examples include fusion and adhesion with an adhesive, and heat fusion is particularly preferable. The implantation density of the net-like base fabric is in the range of 5 to 40 strands / 2.54 cm, preferably 10 to 20 strands / 2.54 cm. The basis weight of the base cloth is 100 to 5
The range is 00 g / m ² , and preferably 150 to 300.
It is in the range of g / m ² .

In the present invention, a laminated sheet is obtained by forming a coating layer on at least one surface of the base fabric obtained above using a resin composition of poly (ethylene terephthalate) and polybutylene terephthalate by an extrusion laminating method. You can Polyethylene terephthalate (PET) is a polymer obtained by polycondensing terephthalic acid or a terephthalic acid derivative as an acid component and ethylene glycol as a glycol component as described above,
A copolymer in which a part of the terephthalic acid component and / or the ethylene glycol component is replaced with a copolymerization component is also included. Also, the above-mentioned recycled polyester can be used.

The intrinsic viscosity (η value) of PET is 0.7 to
The range is 1.3 dl / g, preferably 0.9 to 1.1.
It is in the range of dl / g. When the η value is less than 0.7 dl / g, the neck-in is large and the ear part becomes unstable due to the film shaking phenomenon. On the other hand, when it exceeds 1.3 dl / g, the drawdown property is deteriorated, which is not preferable.

On the other hand, the polybutylene terephthalate resin (PBT) of the present invention is a polymer obtained by polycondensing terephthalic acid or a terephthalic acid derivative as an acid component and tetramethylene glycol as a glycol component as described above. It also includes a copolymer in which a part of the terephthalic acid component and / or the tetramethylene glycol component is replaced with a copolymerization component.

The intrinsic viscosity (η value) of the above PBT is 0.6 to
It is in the range of 1.8, preferably in the range of 0.8 to 1.5. If the η value is less than 0.6, the drawdown is lowered, while if the η value exceeds 1.8, neck-in becomes large, which is not preferable.

The mixing ratio of PET and PBT is in the range of 60 to 90% by weight of PET and 10 to 40% by weight of PBT, preferably 70 to 90% by weight of PET and PB.
T is in the range of 10 to 30% by weight. When the blending ratio of PBT is less than 10% by weight, the flexibility of the obtained laminated sheet is insufficient, while when it exceeds 40% by weight, the melt viscosity of the extruder becomes high and the moldability deteriorates, which is not preferable.

In the extrusion laminating method, the melting temperature is preferably in the range of 260 to 300 ° C, and the surface temperature of the cooling roll is preferably in the range of 10 to 50 ° C. Moreover, the thickness of the coating layer is in the range of 30 to 150 μm, preferably in the range of 50 to 100 μm. The thickness of the adhesive layer is 30
If it is less than μm, the strength of the coating layer becomes insufficient and the adhesive strength becomes insufficient, while if it exceeds 150 μm, the load increases and the rigidity increases, which is not preferable. The basis weight of the laminated sheet is in the range of 150 to 800 g / ^{m 2,} preferably in the range of 200-500 g / ^{m 2.}

Before forming a coating layer on at least one surface of the base fabric by the extrusion laminating method, it is desirable to previously subject the surface of the base fabric to surface treatment such as corona discharge treatment or plasma treatment in order to improve the adhesiveness.

In the present invention, additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, a pigment, a flame retardant, a cross-linking agent, a foaming agent and a nucleating agent are added to the above resin. It can be added within a range that does not essentially impair the characteristics of the present invention.

[0023]

As described above, the laminated sheet of the present invention has a specific range of polyethylene terephthalate and polybutylene terephthalate on at least one side of a base cloth formed by intersecting polyester drawn yarns as warp and weft yarns. By forming a coating layer using the composition by an extrusion laminating method, a polyester laminated sheet suitable for a flexible container having high strength, excellent durability, and flexibility and processability can be obtained.

[0024]

Example 1 Polyethylene terephthalate (η = 0.8 dl / g) was dried by a dryer at 150 ° C. for 5 hours, then extruded by an extruder at a melting temperature of 270 ° C., and cooled by a chill roll cooling method using a T die. To form a film, and the cooled and solidified film is slit into a width of 8 mm, and then the first-stage stretching is performed at 90 ° C. and a draw ratio of 4 times, and then the second-stage stretching is performed at 190 ° C. and a draw ratio of 2
After stretching at twice, a relaxation heat treatment is performed at 200 ° C to obtain a fineness of 200.
A flat yarn of 0 dt was formed. The operation of the extruder was stable without surging. The resulting flat yarn had a tensile strength of 3.6 cN / dt and an elongation of 10.0%. Driving density 14 × 1 using the above flat yarn
A plain weave base fabric was formed with 4 pieces / 2.54 cm. The basis weight of the base fabric was 220 g / m ² . After corona discharge treatment on one side of the above base cloth, polyethylene terephthalate (η = 1.
0 dl / g) 80 wt%, polybutylene terephthalate (η = 1.28 dl / g) 20 wt% was used in the composition, and the extrusion temperature was 2 by the extrusion laminating method.
The coating layer was laminated at 90 ° C., the surface temperature of the cooling roll was 30 ° C., and the thickness was 50 μm to obtain a laminated sheet. The laminated sheet had a basis weight of 330 g / m ² and a tensile strength of 1440 N / 5 cm. A flexible container was obtained by sewing the laminated sheet. This flexible container made of polyester has a high strength and a flexibility suitable for a flexible container, and was suitably used as a flexible container.

COMPARATIVE EXAMPLE 1 In Example 1, extrusion laminating was carried out by using polyethylene terephthalate (η = 1.0 dl / g) alone as a resin without blending polybutylene terephthalate on one side of the above base fabric. Other than that, it carried out similarly. As a result, the obtained laminated sheet was hard and lacked in flexibility, and was not sufficiently satisfactory for the application of a flexible container.

Claims (3)

[Claims] 1. A composition comprising 60 to 90% by weight of polyethylene terephthalate and 10 to 40% by weight of polybutylene terephthalate on at least one side of a net-like base cloth in which drawn yarns made of polyester are used as warps and wefts. Laminated polyester laminated sheet. 2. The polyester laminated sheet according to claim 1, wherein the polyester is polyethylene terephthalate. 3. The polyester laminated sheet according to claim 1, wherein the net-shaped base fabric is a woven fabric.