JP2011051345A - Synthetic resin cup-shaped container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin cup-shaped container having necessary heat-resistance as an area crystallized by heating in a predetermined part of a flange according to purpose, sealing property and appearance property of a lid material. <P>SOLUTION: In the synthetic resin cup-shaped container, the range over the whole thickness, an upper face side part, a lower face side part, predetermined parts of the upper face side part and the lower face side part excepting center parts of the flange are areas crystallized by preheating with a hot plate and heating by laser beam irradiation thereafter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a cup-shaped container made of a synthetic resin in which a flange is thermally crystallized.

  A container such as a so-called PET bottle obtained by biaxially stretching blow-molding a polyethylene terephthalate (hereinafter referred to as PET) resin has mechanical strength, heat resistance, transparency, barrier properties, hygiene, etc. It is excellent and widely used in food containers such as beverages.

  In addition to PET bottles, taking advantage of the above-described superior properties, coffee, milk beverages, etc. are used for high temperature filling for sterilization at about 80 to 90 ° C. or for applications requiring aseptic filling. Wide-mouth cup-shaped containers made of stretch blow molded PET resin or polypropylene resin are in widespread use. The cup-shaped container is used by sealing the container by adhering a lid material such as aluminum foil or resin synthetic paper using the upper surface of a flange provided around the top of the outer casing.

  For example, Patent Document 1 describes a biaxial stretch blow molding method for a wide-mouth cup-shaped container made of PET resin, and the biaxial stretch blow molding is as shown in the schematic explanatory diagram of FIG. The flange 114 portion of the small cup-shaped preform 111 having the flange 114 provided around the upper end is fixed, biaxial stretch blow molding is performed, and the cup-shaped container 101 is molded.

  Here, in the biaxially stretched blow-molded product, the biaxially stretched portion has improved heat resistance due to orientation crystallization by stretching, but the mouth tube portion of the PET bottle or the cup-shaped container described above Although the flange 114 in the preform 111 is in an unstretched state and has a heat resistance of about 70 ° C., it is thermally deformed by a filling process at a high temperature as described above or a hot air sterilization process of hydrogen peroxide.

  In order to improve the heat resistance of the non-stretched parts such as the above-mentioned mouth tube part and flange, the thermal crystallization treatment (so-called whitening) is performed by heating only these parts in the preform state or in the container state. Process). For example, in the case of a PET bottle, a method of irradiating the mouth tube portion with infrared rays or near infrared rays in a preform state is often employed. At this time, the test tubular preform is fixed to a jig and is made uniform over the entire circumference of the mouth tube portion while rotating around the central axis.

Further, as a thermal crystallization treatment method for a flange of a cup-shaped container or a flange and a neck, Patent Document 2 describes a method of partially thermal crystallization by bringing a hot plate into contact with the flange or the like.

JP 2004-268570 A JP 2004-58602 A

  Here, whereas the mouth tube portion of the PET bottle is a thick cylindrical shape, the flange or neck of the cup-shaped container is relatively thin, and there is a slight difference in the strength of the thermal crystallization treatment (spots). For example, when only the flange is thermally crystallized, it is necessary to heat a very limited portion called the flange. In this respect, the conventional method of irradiating infrared rays is partially applied. Heating is difficult.

Further, the method described in Patent Document 2 for heating partially by bringing a hot plate into contact has the following problems.
(1) Small crater-like irregularities are generated on the flange surface in contact with the hot plate, the appearance is impaired, and the sealing performance by the lid is incomplete. The unevenness is presumed to be generated by trapping the component volatilized by heating between the flange surface and the hot plate.
(2) In order to heat only the flange in contact with only the flange, it is necessary to make the hot plate extremely small, and it is difficult to make the heating uniform over the entire circumference of the flange.
For example, if thermal crystallization proceeds in a part of the body of the preform due to the influence of the hot plate, stretching in the biaxial stretch blow molding becomes non-uniform. Further, the appearance is damaged by whitening of the portion.
(3) Since it is not non-contact like infrared irradiation, the preform or the final molded product cannot be rotated and heated uniformly over the entire circumference.

In view of the above, the present invention provides a new thermal crystallization treatment method that has been developed to solve the above-described problems associated with the thermal crystallization treatment method for a portion including a flange of a cup-shaped container. It is an object of the present invention to provide a cup-shaped container having heat resistance necessary for a crystallization region, sealing performance of a lid material, appearance and the like.

Here, first, a new thermal crystallization treatment method for solving the above-described problems of the related art related to the thermal crystallization treatment method for the portion including the flange of the cup-shaped container created by the present inventors will be described. Next, the synthetic resin cup-shaped container of the present invention will be described.
The first method according to this thermal crystallization treatment method is:
To preheat the flange of a synthetic resin cup-shaped container with a hot plate and then heat-crystallize by irradiation with laser light, or to form a synthetic resin cup-shaped container by biaxial stretch blow molding The preform flange is first preheated with a hot plate, and then heated by laser light irradiation for thermal crystallization.

The inventors of the present application first studied heating of the flange by laser light irradiation.
Heating by laser light irradiation can be heated in a non-contact manner like infrared light irradiation, and laser light is excellent in linearity, so it can be irradiated only at a predetermined location, and the width is about several mm. Only a limited part of the flange can be heated.

However, when examining the heating conditions with this laser beam, if the output of the laser beam is increased to shorten the heating time, the entire flange is heated suddenly, melts and deforms greatly, or burns occur. It has been found that there is a problem that it is difficult to control the heating conditions in the manufacturing process.
Further, if the laser beam is irradiated and heated under a mild condition so that such deformation and burning do not occur, the processing time becomes long.
In addition, since it is not sandwiched from above and below by a hot plate, heat shrinkage occurs and the width of the flange becomes considerably narrow even under heating conditions where the output of the laser beam is relatively small and the time is lengthened. It was also found that there was a problem.

The first method described above has been devised in consideration of the advantages and problems of heating with the laser beam described above, and the advantages and problems of heating with the prior art hot plate.
That is, by the process of preheating with the first stage hot plate (hereinafter referred to as preheat process), the flange can be preheated in a short time by heat conduction from the hot plate to a predetermined temperature range, and then the second In the step of heating by irradiating the laser beam of the stage (hereinafter referred to as the heating step), heating is performed in a non-contact manner, so that it is possible to prevent the formation of crater-like irregularities due to the volatilization component on the flange surface, and the heat plate alone Both the problem of unevenness caused by heating at the top and the problem of productivity due to heating by laser beam irradiation alone can be solved.

  Here, when preheating at a higher temperature and longer time in the preheating process, the total time can be shortened, but on the other hand, there is its limit, so that small crater-like irregularities estimated to be caused by volatilization components do not occur, Alternatively, it is necessary to prevent portions other than the predetermined area such as the flange from being heated and thermally crystallized. To what extent this preheating is performed depends on the thickness of the flange, the state of residual stress, and the total processing time. It is possible to decide by conducting a preliminary test etc. in consideration of the above.

  In addition, since the heating time can be shortened in the preheating process, the output of laser light in the heating process is within the range where there is no problem that the flange is deformed or burnt, and the actual thermal crystallization process is performed under stable operating conditions. And the total time of the preheating step and the heating step can be shortened to about ½ of the heating time by the laser beam alone.

  Also, in the preheating process, heating can be performed in a state where free deformation of the flange is constrained by the pressing force of the hot plate to relieve residual stress in the flange, and heating by laser light irradiation in a free state in the heating process It is possible to suppress the occurrence of large contraction deformation and warpage deformation.

  In addition, since heating by laser light irradiation is a non-contact heating method, heating by irradiation can be performed while rotating the irradiated portion, and more uniform thermal crystallization can be achieved over the entire circumference of the flange. .

In addition, the laser beam can be irradiated from the upper surface side, the lower surface side, or both sides of the flange as necessary.
Moreover, the thermal crystallization process of the limited part in a flange becomes possible instead of the whole flange as needed. For example, it is possible to irradiate only the portion of the flange excluding the base end portion and the tip end portion, or to heat and crystallize by limiting only the portion excluding the vicinity of the upper surface side or the lower surface side of the flange. It is also possible to do.

In addition, if necessary, the first method can thermally crystallize a limited width region of the neck at the same time as the flange.
As with the flange, the neck can be heated in two stages of preheating and heating, or is relatively thin and can be heated only by laser light irradiation.

  As described above, the first method related to the thermal crystallization treatment is performed in a short time while regulating deformation by performing the heating of the flange in two stages of preheating with a hot plate and heating with laser light irradiation. It combines the advantages of heating with a hot plate that can be heated in a non-contact manner and the advantage of heating with a laser beam that can be heated in a non-contact manner. Incorporated, it has become possible to provide a container or a preform that does not have a large deformation on the flange and has no irregularities on the flange surface in a short time.

  In the method of performing the two-stage heating with a hot plate and a laser beam at the preform stage, biaxial stretch blow molding is performed using this preform, so that the heat resistance including the flange or the neck portion is improved. A high cup-shaped container can be provided.

  Whether the thermal crystallization treatment is performed in the cup-shaped container that is the final molded product or the preform can be selected in consideration of the overall production process, but the preform is smaller in size. In addition, since the molded product is thick as a whole, there is an advantage that it is easy to hold the posture with a jig and can generally be implemented with high production.

  In the second method related to the thermal crystallization treatment method, the temperature and time conditions of preheating by the hot plate are set in advance so that thermal crystallization does not proceed at the flange and internal stress of the flange can be relaxed. It is in the determined range.

  The second method corresponds to one of the guidelines for setting the range of preheating by the hot plate, and by setting the range in which thermal crystallization does not proceed at the flange, Crystallization can be minimized and crystallization in a portion outside the predetermined range can be suppressed.

  Further, by making it possible to relax the internal stress of the flange, the internal stress can be sufficiently relaxed in the preheating stage. More specifically, it is preferable to preheat for a predetermined time so that the temperature of the flange is equal to or higher than the glass transition temperature of the synthetic resin and equal to or lower than the temperature at which thermal crystallization is promoted.

  The third method according to the thermal crystallization treatment method is to further cool the flange with a cooling plate after the laser beam irradiation.

  According to the third method, the shape of the flange and the surface texture related to the fine irregularities can be made as designed by cooling with the cooling plate, and in particular, the upper surface of the flange can be made flat to facilitate heat sealing of the lid. Can be.

  The fourth method according to the thermal crystallization treatment method is to preheat by further sandwiching the flange from above and below with a hot plate.

According to the fourth method, it is possible to uniformly preheat in a shorter time while restraining the flange more reliably by sandwiching it with a hot plate from above and below.
Note that the preheating with the hot plate is not necessarily limited to the above-described method of sandwiching the plate with the hot plate from above and below, and depending on the purpose, only the upper side or only the lower side can be used as the hot plate. It is preferable to support at least the opposite side with a plate piece or the like in order to ensure the above.

  A fifth method according to the thermal crystallization treatment method is to further irradiate the flange with laser light while rotating the cup-shaped container or preform around the central axis.

  The fifth method is particularly effective when the flange is provided in the outer ring shape around the center axis from the upper end of the cylindrical neck, and the laser beam irradiation position is fixed. By fixing the cylindrical container or preform to a rotatable jig and rotating it around the central axis, the laser beam can be uniformly irradiated over the entire circumference of the flange or neck.

Next, although the synthetic resin cup-shaped container of the present invention will be described, these can be realized by the new thermal crystallization treatment method including the flange of the cup-shaped container described above by the present inventors.
The configuration according to claim 1 relating to the cup-shaped container made of synthetic resin of the present application is
In the synthetic resin cup-shaped container, a predetermined portion of the flange is a heat crystallization region by preheating with a hot plate and subsequent laser light irradiation.

  By performing the heating of the flange in two stages, preheating with a hot plate and subsequent heating with laser light irradiation, a cup-shaped container that can irradiate laser light under stable conditions and has no irregularities on the flange surface in a short time. The laser irradiation can be performed from the upper surface side, the lower surface side, or both sides of the flange, and a limited portion of the flange can be subjected to thermal crystallization treatment. Depending on the purpose, it is possible to provide a cup-shaped container having the required heat resistance, the sealing performance of the lid, the appearance, etc., with the predetermined portion of the flange as the thermal crystallization region.

The structures described in claims 2 to 5 described below define specific thermal crystallization regions in the structure described in claim 1.
According to the second aspect of the present invention, the range over the entire thickness of the flange is the thermal crystallization region.

  According to the above configuration of the second aspect, by setting the range over the entire thickness of the flange as the thermal crystallization region, it can be used for applications requiring high heat resistance such as aseptic filling.

  According to the third aspect of the present invention, the upper surface side portion of the flange is a thermal crystallization region, and the other portion is an amorphous portion.

According to the configuration of claim 3, although the upper side portion is a thermal crystallization region, the thermal crystallization region is not as heat-resistant as when the range over the entire thickness is a thermal crystallization region. Depending on the thickness, heat resistance can be ensured as required. Further, an amorphous region (or a region where thermal crystallization does not progress) can be secured on the lower surface side, and the entire flange can be made difficult to crack due to the toughness of the amorphous region.
In the heating process by laser irradiation, the laser light source may be disposed only on the upper surface side.

  According to a fourth aspect of the present invention, the upper surface side portion of the flange is an amorphous portion, or the crystallization is not allowed to proceed, and the remaining portion is a thermal crystallization region.

  The structure according to claim 4 can be realized by irradiating a laser beam from the lower surface side of the flange, and in particular, a lid material using an aluminum laminated film or a resin synthetic paper as a base material using the upper surface of the flange. It is effective when the container is sealed by heat welding. That is, if the crystallization of the upper surface of the flange, which is the sealing surface, proceeds, it becomes difficult to soften or melt the upper surface of the flange when the lid is heat-welded, making it difficult to bond the lid. By leaving the upper surface side portion as an amorphous portion or not allowing crystallization to proceed as described in the claims, adhesion of the lid can be easily achieved.

Further, according to the above configuration of claim 4, the heat crystallization region other than the upper surface side portion is not as heat-resistant as when the range over the entire thickness is the heat crystallization region. Depending on the thickness of the thermal crystallization region, heat resistance as required can be ensured.
Further, an amorphous region (or a region where thermal crystallization does not progress) can be secured on the upper surface side, and the entire flange can be made difficult to crack due to the toughness of the amorphous region.

  Here, for example, in the case of polypropylene resin, the flange which is an unstretched portion is also partially crystallized, but in the case of PET resin, the flange of the unstretched portion is in an amorphous state. The part is described as an amorphous part or in a state where crystallization does not proceed.

  According to the fifth aspect of the present invention, the upper surface side portion and the lower surface side portion of the flange are thermal crystallization regions, and the intermediate portion is an amorphous region or a region where crystallization does not proceed.

  According to the above configuration of claim 5, it is possible to form a sandwich structure in which an amorphous region having excellent toughness is sandwiched between thermal crystallization regions having high heat resistance and rigidity, and both the heat resistance, rigidity and toughness of the flange are obtained. It can be demonstrated at a high level.

  As described above, the structure of claim 4 can be realized by irradiating laser light from the lower surface side of the flange. However, depending on which part of the flange is a crystallization region, Irradiation can be performed from the top side or from both sides. If necessary, the neck can be irradiated simultaneously from the side. Depending on these irradiation modes, the amorphous part can be left on the upper surface, the lower surface, or the intermediate layer according to the purpose as described in claims 3 to 5, and the crystallized region and the amorphous region are distributed in various ways. Or by changing the degree of crystallization depending on the region.

  According to the sixth aspect of the present invention, the neck portion directly below the flange is used as a thermal crystallization region together with the flange.

  The structure described in claim 7 is made of a PET resin.

  The PET resin can provide a cup-shaped container having excellent transparency and high rigidity by injection molding, biaxial stretch blow molding of a preform, and heating a sheet molded product into a biaxial stretch shape. By molding, a cup-shaped container having more excellent heat resistance, rigidity, strength, and gas barrier properties can be provided.

  In addition, in this claim 7, PET is mainly used as the PET-based resin, but as long as the essence of the PET resin is not impaired, a copolymer polyester mainly containing ethylene terephthalate units and containing other polyester units is also used. In addition, for example, in order to improve gas barrier properties and heat resistance, resins such as nylon resins and polyethylene naphthalate resins can be blended and used. Examples of the component for forming the copolyester include dicarboxylic acid components such as isophthalic acid, naphthalene 2,6 dicarboxylic acid, and adipic acid, propylene glycol, 1,4 butanediol, tetramethylene glycol, neopentyl glycol, cyclohexanedimethanol, Mention may be made of glycol components such as diethylene glycol.

Furthermore, in this Claim 7, as a cup-shaped container made of a PET resin or a preform, as long as the essence as a PET resin is not impaired, for example, in order to improve heat resistance and gas barrier properties, It may be laminated with other resins such as polyethylene naphthalate resin or PET resin / nylon resin / PET resin.

The synthetic resin cup-shaped container of the present invention has the above-described configuration and exhibits the following effects.
In the structure of claim 1, the laser beam can be irradiated from the upper surface side, the lower surface side, or both sides of the flange, and a limited portion of the flange can be thermally crystallized. Accordingly, it is possible to provide a cup-shaped container having the required heat resistance, the sealing property of the lid material, the appearance, and the like using the predetermined portion of the flange as the thermal crystallization region.

  In the structure of Claim 2, it can be used for the use as which high heat resistance, such as aseptic filling, is required by making the range over the whole thickness of a flange into a thermal crystallization area | region.

  In the configuration according to claim 3, heat resistance as required can be ensured by the thickness of the thermal crystallization region, and an amorphous region (or a region where thermal crystallization does not progress) is provided on the lower surface side. Can be secured, and the toughness of the amorphous region makes it difficult to crack the entire flange.

  In the configuration according to claim 4, the lid material based on an aluminum laminate film or a resin synthetic paper is thermally welded by leaving the upper surface portion of the flange as an amorphous portion or without allowing crystallization to proceed. Can be easily adhered, and the container can be easily and reliably sealed.

  In the configuration of claim 5, the amorphous region can be sandwiched between the thermal crystallization regions, and the heat resistance and rigidity and toughness of the flange can be exhibited at a high level. .

  In the configuration according to claim 6, the neck part directly below the flange is used as a thermal crystallization region together with the flange, so that the neck part is hardly stretched in the lateral direction and has insufficient heat resistance depending on the application. It is possible to provide a cup-shaped container having improved heat resistance.

In the invention according to claim 7, the PET resin is a synthetic resin suitable for biaxial stretch molding, and has excellent heat resistance by performing biaxial stretch blow molding and thermal crystallization treatment of the flange. A cup-shaped container having strength and gas barrier properties can be provided.

It is explanatory drawing which shows schematically embodiment of the thermal crystallization processing method. FIG. 2 is a front view showing a part of the preheating step in FIG. It is a front view which partially shows the heating process in FIG. 1 longitudinally. It is explanatory drawing which shows the irradiation state of the laser beam in FIG. 3 with the top view of a preform. FIG. 2 is a front view showing a part of the cooling process in FIG. FIG. 2 is a semi-longitudinal sectional view schematically showing an example of a pattern of a thermal crystallization region of a flange of a preform formed in the cup-shaped container of the present invention obtained by the processing method of FIG. 1. It is explanatory drawing which shows the example of a pattern of the other thermal crystallization area | region of the preform shape | molded by the cup-shaped container of this invention. It is a schematic explanatory drawing which shows the other example of a heating process. It is explanatory drawing which shows the example of a pattern of the further another thermal crystallization area | region of the preform shape | molded by the cup-shaped container of this invention. It is a half vertical front view which shows one Example of the cup-shaped container of this invention. It is a schematic explanatory drawing of the biaxial stretch blow molding of a cup-shaped container.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an explanatory diagram schematically showing a new thermal crystallization treatment method for a portion including a flange of a cup-shaped container or its preform created by the inventors of the present invention, and a preheating step H1 by a hot plate 33; A heating process H2 by irradiation with the laser beam 32 and a cooling process CL by the cooling plate 35 are included. 2 shows the preheating step H1, FIG. 3 shows the heating step H2, and FIG. 5 shows the cooling step CL.

  Although FIG. 2 shows the preheating process H1, the preform 11 used is made of injection-molded PET resin, is colorless and transparent, and is entirely amorphous. The preform 11 has a small cup shape, has a bottom portion 13, an upper end portion of the trunk portion 12 is a cylindrical neck portion 15, and a flange 14 is provided around the upper end in the shape of an outer casing. The flange 14 has a width of 4 mm, an average thickness of 2 mm, and an outer diameter of 80 mm.

  Preheating is performed while restraining the deformation of the flange 14 in a state where the upper and lower ring-shaped heat plates 33 (33a, 33b) are pressed from above and below.

Next, FIG. 3 shows the heating process H2 by laser beam irradiation.
The preform 11 is fixed in an inverted posture to the rotation fixing jig 21 with the core 21a inserted and the upper surface 14a of the flange 14 in contact with the flat plate portion 21b. In this state, the laser beam 32 irradiated from the laser irradiation device 31 is irradiated from the lower surface 14b side of the flange 14 while the rotation fixing jig 21 is rotated around the central axis by the shaft body 21c. FIG. 4 is an explanatory view showing a state in which the laser beam 32 having an irradiation diameter of 4 mm is irradiated on the flange 14 having a width of 4 mm by a plan view of the preform 11. Can be maintained.

  Next, FIG. 5 shows a cooling process CL. Cooling is performed in a state of being pressed from above and below by a pair of upper and lower ring-shaped cooling plates 35 (35a, 35b) provided with cooling pipes 36. To do.

Next, an example of the embodiment shown in FIG. 1 will be shown. Detailed implementation conditions are as follows.
(1) Preheating process H1
The temperature of the hot plate 33 is 115 to 135 ° C. and the preheating time is 10 seconds. The above conditions are such that thermal crystallization does not proceed on the flange 14 (whitening due to thermal crystallization does not occur) and the temperature of the flange 14 is made of PET resin. This is determined by a preliminary test so that the internal stress is sufficiently relaxed at a glass transition temperature (about 80 ° C.) or higher.
(2) Heating process H2
・ Laser irradiation device 31 used; carbon dioxide laser device (wavelength 10.6 μm)
Pulse frequency 1000HZ, pulse width 100μm, irradiation diameter 4mm
・ Rotation speed of the rotation fixing jig 21: 60 rpm
・ Irradiation time: 20 seconds (3) Cooling process CL
・ Cooling plate 35 temperature 25-30 ° C., cooling time 5 seconds

In the thermal crystallization process under the above-described conditions, the flange 14 was not whitened in the preheating step H1.
Further, when the whitening state of the preform 11 obtained in a series of steps up to the cooling step CL is observed, an annular thermal crystallization region C (whitening region) indicated by cross hatching in FIG. Thermal crystallization is realized with a constant width over the entire circumference of 14.
6 is a view of the thermal crystallization region C in the longitudinal section of the flange 14, but the upper surface 14a side portion leaves a substantially constant thickness as an amorphous region N, and other portions ( The cross-hatched part) could be the thermal crystallization region C.
Further, the upper surface 14a and the lower surface 14b of the flange 14 had no crater-like irregularities, and the flange 14 was warped and the tip portion was not deformed obliquely upward, so that it could be in a horizontal and flat state.

  Next, as a comparative example, the preheating step H1 was omitted, and the cooling step CL was performed in the same manner as in the example, and the thermal crystallization treatment was performed by changing the irradiation time without changing other conditions in the heating step H2. In order to give the flange 14 the same heat resistance as that of the embodiment by thermal crystallization, a time of about 60 seconds was required. In addition, because of the heating in a state where the flange 14 is not restrained, the flange width W eventually contracted by about 50%.

Further, when the output of the laser irradiation device 31 is increased in order to shorten the irradiation time, the temperature rapidly increases, the flange 14 is partially melted and greatly deformed, or the resin is burned. Therefore, stable heating was difficult.
As can be seen from the results of the example and the comparative example, by providing the preheating step H1 with the hot plate 33, the heating time can be shortened from 60 seconds to 30 seconds including preheating. The effect of the thermal crystallization treatment method of the invention was confirmed. Further, it has been found that the method of the present invention is also effective from the viewpoint of suppressing deformation of the flange 14 (particularly thermal shrinkage of the flange width W).

FIG. 10 shows a biaxially stretched preform 11 in which a substantially constant thickness is left as an amorphous region N in the portion on the upper surface 14a side of the flange 14 as shown in FIG. FIG. 3 is a half longitudinal front view showing an embodiment of the cup-shaped container 1 of the present invention, which is blow-molded, having a bottom portion 3 and a cylindrical body portion 2, and having a collar shape at the upper end of the neck portion 5. A flange 4 having a pattern similar to the pattern of the thermal crystallization region of the flange 14 shown in the partially enlarged view in FIG.
FIG. 10 shows a state in which the lid 6 is bonded by heat melting using the flange 4 and the container is sealed.

  As the base material of the lid member 6, a polypropylene resin film, a PET resin film, a synthetic paper composed of a synthetic resin and an inorganic filler, and an aluminum laminate film can be used. As an adhesive layer, for example, a low density polyethylene resin, A hot melt type of ethylene-vinyl acetate copolymer or the like can be used, but the upper surface 4a portion of the flange 4 is horizontally flat and is an amorphous region N as shown in FIG. The lid 6 can be heat-sealed easily and reliably because it softens at a temperature of about 80 ° C.

  In the above embodiment, the flange 14 is preheated from the upper and lower sides with the hot plate 33, and the laser beam 32 is irradiated from the lower surface 14b side in the heating step H2, but the preheating by the hot plate 33 is performed only from the upper surface side. Alternatively, the laser beam 32 can be irradiated only from the lower surface side or from the upper surface side or from both surfaces. Further, the temperature of the upper and lower hot plates 33 can be changed, or the upper and lower laser beams can be irradiated. The intensity of 32 and the irradiation area can also be changed.

That is, depending on the purpose, the pattern of the thermal crystallization region of the flange 14 can be changed to various modes by combining preheating or heating methods in various modes. FIG. 7 shows pattern examples of three types of thermal crystallization regions C (a), (b), and (c).
(A) shows the entire thickness range of the flange 14, (b) shows the upper surface 14a side portion, (c) shows the intermediate portion in the amorphous state N, and the upper surface 14a side portion and the lower surface 14b side portion are thermocrystallized. In this way, the preform 11 having the pattern of the thermal crystallization region C is biaxially stretched and blow-molded on the flange 14 in this manner, whereby the same pattern of the thermal crystallization region C is formed on the flange 4. A cup-shaped container can be obtained.

  Next, in the above embodiment, an example in which only the flange 14 is thermally crystallized has been described. However, depending on the purpose of use, the thermal crystallization process can be performed including the neck portion 15 immediately below the flange 14. For example, in the example of the biaxial stretch blow molding shown in FIG. 11, the neck portion 115 of the preform 111 is slightly stretched in the longitudinal direction but hardly stretched in the lateral direction. The heat resistance of 105 may be insufficient, and in such a case, thermal crystallization processing is required for the neck portion 115 as well as the flange 114 of the preform 111.

  For example, in the preheating step H <b> 1 shown in FIG. 2, the neck 15 can be preheated by making the shape of the lower heat plate 33 b so that part of the side faces the neck 15. Further, in the heating step H2, as shown in FIG. 8, the laser irradiation device 31 can also be installed in the lateral direction to irradiate the neck 15 with the laser beam 32.

As shown in FIG. 8, the laser irradiation device 31 is also installed in the lateral direction, and the formation pattern of the whitened region C in the vicinity of the flange 14 when the neck 15 together with the flange 14 is subjected to thermal crystallization treatment by irradiation with the laser light 32 Two examples are shown in FIGS. 9A and 9B.
Then, the preform 11 subjected to the thermal crystallization treatment by the irradiation of the laser beam 32 as well as the neck portion 15 together with the flange 14 is subjected to biaxial stretch blow molding, thereby forming the flange 4 and the neck portion 5 in FIG. A cup-shaped container having a pattern of the thermal crystallization region C similar to that shown in (b) can be obtained.

As mentioned above, although embodiment of this invention was described, this invention is not limited to an above-described Example.
For example, a biaxial stretch blow-molded cup-shaped container is not limited to a PET resin, and a polypropylene-based cup is also a cup-shaped container having excellent heat resistance and strength by biaxial stretch blow molding.

  Moreover, although the said Example is an example which implements a thermal crystallization process in the state of the preform 14, the thermal crystallization process of the flange 4 can be implemented also in the state of the cup-shaped container 1 which is a final molded product.

In addition to the cup-shaped container formed by biaxial stretch blow molding, the effect of the present invention can be sufficiently exerted for a thermo-formed cup-shaped container or an injection-molded cup-shaped container. This is an extremely effective method for promoting crystallization of a limited portion of the neck, increasing rigidity and improving heat resistance.

As described above, the cup-shaped container made of the synthetic resin according to the present invention can provide necessary heat resistance, sealing performance of the lid, appearance, etc. depending on the purpose, with a predetermined portion of the flange as a thermal crystallization region. It is expected to be used widely.

DESCRIPTION OF SYMBOLS 1; Cup-shaped container 2; Body part 3; Bottom part 4; Flange 4a;
4b; lower surface 5; neck 6; lid 11; preform 12; trunk 13; bottom 14; flange 14a;
14b; lower surface 15; neck portion 21; rotation fixing jig 21a; core 21b; flat plate portion 21c; shaft body 31; laser irradiation device 32; laser light 33, 33a, 33b: hot plate 35, 35a, 35b; 101; Cup-shaped container 104; Flange 105; Neck 111; Preform 114; Flange 115; Neck N; Amorphous region C; Thermal crystallization region (whitening region)
W; flange width H1; preheating step H2; heating step CL; cooling step

Claims (7)

A synthetic resin cup-shaped container in which a predetermined portion of the flange (4) is a thermal crystallization region (C) by preheating with a hot plate (33) and then irradiation with a laser beam (32). The synthetic resin cup-shaped container according to claim 1, wherein a range over the entire thickness of the flange (4) is defined as a thermal crystallization region (C). The synthetic resin cup-shaped container according to claim 1, wherein the upper surface (4a) side portion of the flange (4) is a thermal crystallization region (C) and the other portion is an amorphous portion. The synthetic resin cup according to claim 1, wherein the upper surface (4a) side portion of the flange (4) is an amorphous portion or is left in a state where crystallization does not proceed, and the other portion is a thermal crystallization region (C). Container. The upper surface (4a) side portion and the lower surface (4b) side portion of the flange (4) is a thermal crystallization region (C), and the intermediate portion is an amorphous region (N) or a region where crystallization does not proceed. The cup-shaped container made of synthetic resin according to 1. The synthetic resin cup-shaped container according to claim 1, 2, 3, 4 or 5, wherein the neck (5) immediately below the flange (4) is the thermal crystallization region (C) together with the flange (4). The synthetic resin cup-shaped container according to claim 1, which is made of a polyethylene terephthalate resin.

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