JPH05147656A - Bottle with base cup - Google Patents

Abstract

PURPOSE:To provide a bottle with base cup of which the recycling is easy. CONSTITUTION:The title bottle is a biaxially oriented blow molded bottle which consists of a bottle main body part 2 and a base cup 3. The bottle main body part 2 and the base cup 3 are made of a polyester resin, and the base cup 3 is fixed on the bottom 24 of the bottle main body part 2 by an adhesive made of a polyester resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic bottle with a base cup. More specifically, both the bottle body and the base cup are made of a polyester resin, and the base cup is attached by a polyester resin. The present invention relates to a bottle made of a polyester-based resin that uses an agent and is easy to recycle after use.

[0002]

BACKGROUND OF THE INVENTION Biaxially stretched blow molded bottles made of saturated polyester resin represented by polyethylene terephthalate have excellent transparency and surface gloss, and are beautiful and have a gas barrier. Excellent in water resistance, water impermeability, content resistance, and storage stability. Further, it has many advantages such as easy disposal because it generates little heat during combustion and does not damage the furnace. Therefore, it is widely used in various drinking water, seasonings, containers (bottles) for foods such as alcoholic beverages, and the like.

Among such biaxially stretch blow-molded bottles, there is one in which a so-called base cup is attached to the bottom. The base cup adds self-reliance to the bottle,
Also, in some cases it is installed to reinforce the bottom part,
This is often used, for example, for bottles whose contents have a high internal pressure, such as carbonated drinks. This is because, in such a bottle, it is common to mold the bottom of the bottle into a rounded convex shape in order to improve the internal pressure resistance.

In the conventional bottle with a base cup,
A base cup made of a resin such as polyethylene or polypropylene is fixed to a bottle main body which is biaxially stretch blow molded using a hot melt adhesive made of a polyolefin resin or the like. The base cup was formed by using the above-mentioned resin by a method such as injection molding, vacuum molding, or pressure molding.

By the way, in recent years, it has been considered to recycle used bottles for reasons such as resource saving and environmental protection. In recycling resin products (for example, resin bottles), it is necessary to separate and collect those made of the same type of resin, but with conventional bottles with a base cup,
Since the resin forming the base cup and the resin of the bottle body (typically a polyester resin such as polyethylene terephthalate) are generally different, it is necessary to remove the base cup from the bottle body during recycling. However, in the conventional bottle as described above, since the base cup is adhered to the bottle body, it is not easy to remove it, which is inconvenient for recycling.

Therefore, it is an object of the present invention to provide a bottle with a base cup that is easy to recycle.

[0007]

As a result of earnest research to solve the above-mentioned problems, the present inventor has made both the base cup and the bottle main body from a polyester resin and attached the base cup to the polyester resin. The present invention has been completed by finding that a bottle made of an adhesive made of a resin can be easily recycled after the bottle is used without removing the base cup from the main body of the bottle.

That is, in the biaxially stretch blow-molded bottle of the present invention equipped with a base cup, both the bottle body and the base cup are made of polyester resin, and the base cup is made of an adhesive made of polyester resin. It is characterized by being fixed to the main body.

[0009]

The present invention will be described in detail below. 1 is a sectional view showing a bottle with a base cup according to an embodiment of the present invention, FIG. 2 is a vertical sectional view of a base cup used therein, and FIG. 3 is a top view thereof.

The bottle 1 comprises a bottle body 2 and a base cup 3. In this embodiment, the bottle body 2
Comprises a mouth portion 21 having a support ring 28, a conical shoulder portion 22 having a smooth curved surface, a substantially cylindrical body portion 23, and a substantially hemispherical rounded bottom portion 24. .. Further, an enlarged diameter portion 23a is formed at the lower end of the body portion 23, and the enlarged diameter portion 23a acts as a lateral rib to reinforce this portion. As shown in FIG. 1, if the bottom portion 24 has a substantially hemispherical and rounded shape, a large internal pressure can be sufficiently dealt with. The shape of each part of the bottle body 2 may be variously changed so as to be the same as a known biaxially stretch blow-molded bottle of this type.

On the other hand, the base cup 3 comprises a substantially cylindrical side wall portion 32 and a bottom wall portion 31. An annular grounding portion 33 is formed on the outer peripheral portion of the bottom wall portion 31, and this portion serves as the leg portion of the bottle 1. In addition, inside the grounding portion 33,
An upper surface inwardly inclining slightly downward is formed, and an upwardly convex base portion 34 formed in an annular shape is formed. The base portion 34 serves as a portion that comes into contact with the bottom portion 24 of the bottle body portion 2, and at this portion, the base cup 3 and the bottle body portion 2 are fixed to each other by a polyester adhesive described later. In addition, the bottom central portion 35 located further inside the base portion 34,
It is formed lower than the base portion 34.

The base cup 3 is mounted on the bottle body 2 by means of an annular base 3 provided on the bottom wall 31 of the base cup 3.
This can be easily performed by applying an adhesive agent made of polyester resin to the upper surface of 4 and inserting the bottle main body 2 from above the base cup 3. The portion of the polyester resin to which the adhesive is applied serves as the upper surface of the pedestal portion 34 as described above, but it is not necessary to apply the adhesive evenly to this surface. For example, as shown by the diagonal lines in FIG. It suffices to apply spot-wise on a small area P as small as a spot.

The base cup 3 is fixed to the bottle main body 2 by a base portion 34 formed on the bottom wall portion 31 of the base cup 3. The upper end of the side wall portion 32 of the base cup 3 is above the bottom portion 24 of the bottle main body 2. A small gap is formed between the parts. This gap does not have to be formed uniformly along the entire circumference of the upper end of the side wall portion 32, but a sufficient amount of hot water can be used in the pasteurizing of the hot shower method performed after the contents are filled. It is formed so as to pass through this gap and reach the bottom portion 24. Although not shown, the bottom wall portion 31 of the base cup 3 has a side wall portion 32 of the base cup 3.
A plurality of holes for discharging the water that has entered through the gap between the upper end of the bottle and the bottom 24 of the bottle body 2 are formed.

A label is attached to a filled bottle that is distributed as a product, but the treatment of this label also poses a problem in recycling. That is, when the collected empty bottle has a label such as paper or a film made of a resin other than polyester, it must be peeled off first, which is troublesome. Therefore, in the present invention, the label made of a polyester resin film may be attached to the bottle 1. By doing this, not only the bottle body, the base cup, and the adhesive that bonds them, but also the label is made of polyester resin, so you can send an empty bottle for recycling without removing the label from the bottle. And the efficiency of recycling is greatly improved.

If the ink component in the printed label greatly contaminates the (recycled) polyester resin during recycling, it is preferable to pre-perforate the label. In this case, it is not necessary to manufacture the label itself from the polyester resin, and the label is torn along the perforations when recycling.

The polyester adhesive used in the present invention is
A hot melt adhesive mainly composed of polyester,
A dibasic acid such as terephthalic acid or isophthalic acid and various alkyl diols are used, and these are ester-copolymerized. Specifically, polyethylene terephthalate
A saturated copolymer resin such as sebacate or polyethylene terephthalate / adipate can be used. The adhesive performance of such a hot melt adhesive can be adjusted by changing the amounts of various dibasic acid and diol components (amounts of each component in the copolymer resin).

Adhesion with a hot melt adhesive made of polyester resin can be carried out by a known method.

Polyester is suitable as the resin forming the bottle body. As the polyester resin, a thermoplastic resin composed of saturated dicarboxylic acid and saturated dihydric alcohol can be used. Saturated dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-1,4-
Or 2,6-dicarboxylic acid, diphenyl ether-4,4′-dicarboxylic acid, diphenyldicarboxylic acids, aromatic dicarboxylic acids such as diphenoxyethanediethanedicarboxylic acid, adipic acid, sebacic acid, azelaic acid, decane-
Aliphatic dicarboxylic acids such as 1,10-dicarboxylic acid and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used. As the saturated dihydric alcohol, aliphatic glycols such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, hexamethylene glycol, dodecamethylene glycol and neopentyl glycol are used. Glycols, cycloaliphatic glycols such as cyclohexanedimethanol, 2,2-bis (4 '
-β-hydroxyethoxyphenyl) propane, other aromatic diols and the like can be used. A preferred polyester is polyethylene terephthalate consisting of terephthalic acid and ethylene glycol.

The above-mentioned polyester is also suitable as the resin forming the base cup 3, and is appropriately selected according to the resin forming the bottle body 2.

Polyester resin is produced by melt polymerization, 1
Those that have been subjected to reduced pressure treatment or heat treatment in an inert gas atmosphere at a temperature of 80 to 250 ° C., or those that have reduced the content of oligomers and acetaldehyde which are low molecular weight polymers by solid-state polymerization are suitable.

In the polyester resin, additives such as stabilizers, pigments, antioxidants, heat deterioration preventing agents, UV deterioration preventing agents, antistatic agents, antibacterial agents, etc. may be used in the range not impairing the object of the present invention. An appropriate amount of resin can be added.

The bottle body using the above-mentioned resin can be manufactured by a known biaxial stretch blow molding method.

The base cup 3 can be manufactured by publicly known injection molding, vacuum molding, pressure molding or the like, but for giving a strong strength to the base cup 3, it is manufactured by biaxial stretch blow molding. Is preferred.
The base cup 3 can be manufactured by the biaxial stretch blow molding as follows.

First, a bottomed cylindrical parison is manufactured.
The parison can be produced by a known injection molding using the above-mentioned polyester resin, and the polyester resin used at that time is not only a novel resin prepared from the above-mentioned components but also involves a heating and melting once. Recycled products that have undergone the molding process, such as those that have been molded into bottles, or non-product parts that will be cut off from the intermediate molded product obtained during the manufacturing process of the base cup (which will be described in detail later). You can

The polyester resin to be recycled (which has already been molded by heating and melting) is once crushed to remove fine powder, preferably crystallized, and then sufficiently dried to be used as a resin for injection molding. Can be used.
In addition, the parison as described above may be molded only with the recycled polyester resin, or if necessary, the recycled polyester resin and the new polyester resin may be mixed and used.

The polyester resin used for injection molding of the parison has an intrinsic viscosity of 0.7 to 0.8 when it is a new resin.
The degree is good, but it is not limited to this as long as the injection molding is well performed. Further, in the case of recycled polyester resin (or a mixture of this and a new polyester resin), the intrinsic viscosity is lower than that of the new polyester resin. A polyester resin having an intrinsic viscosity of 0.65 or less can also be suitably used. When a recycled polyester resin is used, one having an intrinsic viscosity of about 0.5 to 0.7 is preferably used.

After a bottomed cylindrical parison is obtained from the above-mentioned resin by injection molding, an intermediate molded body having a shape as schematically shown in FIG. 4 is then manufactured by biaxial stretch blow molding. This biaxial stretch blow molding may be performed according to a known method.

The intermediate molded body 4 includes a mouth 46 and the mouth 4
6-like conical shoulder 47 with a large diameter downward
And a body portion 42 that is formed into a substantially cylindrical shape, and a bottom portion 41 that has an annular grounding portion 43.

The cone-shaped shoulder 47 has a large diameter downward, and connects the mouth 46 and the cylindrical body 42.
The diameter of the cone-shaped shoulder portion 47 is expanded so that the angle (θ in FIG. 4) between the surface R perpendicular to the axis of the intermediate molded body 4 and the cone surface 47a of the shoulder portion is 5 ° or less. Preferably. Also,
It is preferable that the conical shoulder portion 47 is thinly formed, and specifically, the thickness thereof is 0.2 mm or less. When the conical surface-shaped shoulder portion 47 is formed so as to have such a diameter-expanded state and thickness, the portion to be cut off (non-product portion that does not serve as the base cup) is reduced. Specifically, the weight of the portion to be cut off is 20% by weight or less of the entire intermediate molded body 4, and the amount of resin to be recycled is reduced, which is preferable.
The conical shoulder 47 preferably has a stretching ratio of about 8 to 15.

The body portion 42 is formed into a substantially cylindrical shape and is largely stretched. The draw ratio of the body portion 42 is 3 to
It is preferable that the stretching ratio is about 15, preferably about 6 to 13, and even if the stretching ratio is set to about this value, it is usually 0.2
Large mechanical strength and heat resistance can be imparted.

The bottom portion 41 has an annular ground portion 43 as described above.
And has a base 44 that is an adhesive portion with the bottle body.
Also has. The stretching ratio of the bottom portion 41 is preferably about 6 to 10 except for the central portion (pole portion) of the bottom portion.

When the above-mentioned intermediate molded body 4 is obtained by the biaxial stretch blow molding, it is heat-treated (heat set) in a stretch blow molding die or the like, if necessary, and released.

Next, the body 4 of the intermediate molded body 4 is cut with a cutter or the like.
Cut the entire circumference of 2 (C part shown in FIG. 4). The cut lower part becomes the base cup.

The base cup manufactured by the above-mentioned method has a good strength due to the stretching effect, and is subjected to hot shower by the stretching effect and the effect of heat setting immediately after the biaxial stretch blow molding. Sufficient heat resistance is imparted.

Although the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. For example, the shapes of the bottle body and the base cup can be changed in various ways like the conventional bottles.

[0036]

As described in detail above, in the bottle with a base cup of the present invention, the bottle main body portion, the base cup, and the adhesive for connecting both are made of polyester resin. It can be easily recycled without removing it.

Further, a label made of polyester resin can be attached to the bottle having such a structure to make recycling more efficient.

The bottle with a base cup of the present invention is suitable for bottles of various foods and drinks including carbonated drinks.

[Brief description of drawings]

FIG. 1 is a sectional view showing a bottle with a base cup according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a base cup used in the bottle shown in FIG.

FIG. 3 is a top view of the base cup of FIG.

FIG. 4 is a schematic cross-sectional view showing an example of an intermediate molded body obtained in the process of manufacturing a base cup that can be used in the bottle of the present invention.

[Explanation of symbols]

 1 Bottle with Base Cup 2 Bottle Main Body 3 Base Cup 4 Intermediate Molded Body 21 Mouth 22 Shoulder 23 Body 25 Bottom 31 Base Cup Bottom Wall 32 Base Cup Side Wall 33 Grounding Section 34 Stand

Claims (2)

[Claims] 1. A biaxially stretched blow-molded bottle equipped with a base cup, wherein both the bottle body and the base cup are made of a polyester resin, and the base cup is attached to the bottle body by an adhesive made of a polyester resin. A bottle with a base cup characterized by being fixed. 2. The bottle with a base cup according to claim 1, wherein the bottle is equipped with a label made of a polyester resin.