JPH034029B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention applies to press-through packs (hereinafter referred to as PTP) used for packaging pharmaceutical tablets, capsules, etc.
The present invention relates to a polypropylene composite film used for packaging (abbreviated as packaging). [Prior Art] Due to recent improvements in molding machines, polypropylene films (including sheets) have begun to be used for applications such as food and pharmaceutical packaging and containers. However, these packaging, especially the film for PTP packaging,
Water vapor barrier properties, moldability (wide range of suitable molding,
It is required that each property has good properties such as shape determination, thickness unevenness, transparency), processing suitability (slit line processing, punching performance, adhesion of Al foil), and prevention of curling of the final product. It has not been possible to obtain a product that satisfies all the characteristics and has some problems. As an improvement on these, a film is known in which 3 to 20 wt % of petroleum resin is simply mixed with polypropylene (for example, JP-A-59-143613). However, although this improves moldability and transparency, it tends to stick when hot molded, resulting in an opaque product. For this reason, the appropriate moldable range is very narrow, which poses a practical problem. Furthermore, heating during molding causes elongation and pitch deviation, making uniform molding impossible. Curling occurs in the final product, which significantly reduces the value of the product and also causes problems when it is assembled and packaged. [Object of the invention] The present invention has the above-mentioned characteristics necessary for PTP packaging,
In other words, excellent water vapor barrier properties, moldability (wide range of suitable molding, mold definition, thickness unevenness, transparency),
The aim is to provide a polypropylene film for PTP packaging that satisfies all quality requirements, including suitability for processing (slit line processing, punching performance, adhesion of Al foil), and prevention of curling in the final product. [Structure of the Invention] The present invention provides a composite film in which the (B) layer is laminated on both sides of the (A) layer, in which the (A) layer is made of polypropylene 92~
A layer consisting of 60 wt% of polypropylene mixed with 8 to 40 wt% of one or more petroleum resins that do not contain polar groups, and layer (B) is a mixture of 99.5 to 93 wt% of polypropylene and one or more petroleum resins that do not contain polar groups. The polypropylene composite film for press-through packs is characterized by a layer containing 0.5 to 7 wt% of the polypropylene composite film, and the total thickness of layer (B) is 5 to 30% of the thickness of the composite film. Although the polypropylene of the layers (A) and (B) applied to the film of the present invention is not particularly limited,
Isotactic index (II) is 90% or more, and intrinsic viscosity [η] measured with tetralin is 0.8
-4.0, especially those in the range of 1.2-2.7 are preferred. (A) layer and (B) layer are polypropylene homopolymer,
Alternatively, polypropylene may be copolymerized with other components such as ethylene and butene within a range that does not significantly inhibit crystallinity;
It may be a mixture of both. Note that, in view of the gist of the present invention, a homopolymer is preferable.
Of course, both layers (A) and (B) include known additives to this polypropylene such as crystal nucleating agents, antioxidants, heat stabilizers, slip agents, antistatic agents, antiblocking agents, fillers, viscosity modifiers, etc. A coloring inhibitor or the like may be added. A petroleum resin that does not contain polar groups is a petroleum resin that does not contain hydroxyl groups (-
OH), carboxy group (-COOH), halogen group (-X), sulfonate group (-SO ₃ Y, Y=H, Na,
petroleum resins that do not have polar groups, such as Mg, etc.), and modified products thereof, i.e., resins whose main raw materials are cyclopentadiene-based directly from petroleum-based unsaturated hydrocarbons, or higher olefin-based hydrocarbons. It is. The glass transition temperature Tg of the petroleum resin is preferably 50°C or higher, more preferably 76°C or higher for the film of the present invention. Further, it is particularly preferable that the film of the present invention is a hydrogenated petroleum resin in which hydrogen is added to the petroleum resin so that the hydrogenation rate thereof is 80% or more, preferably 95% or more. Typical resins include hydrogenated alicyclic petroleum resins (e.g., trade name “Escoretsu” (Exxon Chemical)).
and so on. In addition, petroleum resins that do not contain polar groups include hydroxyl groups, aldehyde groups, ketone groups, carboxyl groups,
It includes terpene resins that do not have polar groups such as halogen groups, sulfonic groups, and modified products thereof, that is, hydrocarbons having a composition of (C ₅ H ₈ ) _o and modified compounds derived therefrom.
Terpene resins are also sometimes called terpenoids. Typical compound names include pinene, carene, myrcene, ocimene, limonene,
Terpinolene, terpinene, sapinene, tricyclene, pisabolene, gingiperene, santarene,
campholene, mylene, totalene, etc. In the case of the film of the present invention, it is desirable to add hydrogen so that the hydrogenation rate is 80% or more, preferably 90% or more. Particularly hydrogenated β-pinene, hydrogenated dipentene etc. are preferable. If the petroleum resin does not contain the polar groups described above, the water vapor barrier properties after molding will deteriorate, making it unsuitable for the film of the present invention. The polypropylene film (A) layer of the present invention comprises 92 to 60 wt% of the above-mentioned polypropylene, preferably 90 to 60 wt%.
70wt%, one or more of the above-mentioned petroleum resins that do not contain polar groups (hereinafter referred to as specific resins)
It is a mixture of 40 wt%, preferably 10 to 30 wt%. In addition, the wt% stated in this specification is
It is expressed so that the sum of polypropylene and specific resin is 100wt%. The specific resin
If it exceeds 40wt%, the film becomes brittle and cannot be molded. Furthermore, if it is less than 8 wt%, the water vapor barrier properties will not improve, and furthermore, moldability, transparency, processing suitability, and curling of the final product will deteriorate. The polypropylene film (B) layer of the present invention comprises 99.5 to 93 wt% of the above-mentioned polypropylene, preferably 99.2 wt%
~95wt%, and 0.5% of one or more of the above-mentioned specific resins
-7wt%, preferably 0.8-5wt%. 0.5wt
If it is less than %, the appropriate range of moldability will be narrowed, the bonding temperature of the Al foil will be high, and the bondability will be poor. In addition, the curl of the final product (the state in which the contents are filled after molding, Al foil is laminated, slit wire processed, and punched out) deteriorates the product value, and it also causes problems in terms of integrated packaging, making it unusable. do not have. If it exceeds 7wt%, the appropriate range of moldability will be narrowed and transparency will deteriorate. The composite film of the present invention must have a three-layer structure in which the (B) layer is laminated on both sides of the (A) layer. (B) If the layer is one-sided, the film will curl even before molding, and after molding, the curl will become even worse and the final product will have a large curl, making it unusable. Furthermore, depending on the molding machine, the film may become sticky and opaque, and in severe cases, it may become impossible to run. The three-layer film of the present invention has a
(B) The total composition ratio of the layers is 5 to 30%, preferably 7%.
Must be ~20%. If it is less than 5%, the appropriate range of moldability will be narrowed, and poor punchability will occur in terms of processing suitability. Furthermore, it is not possible to prevent the final product from curling. If it exceeds 30%, thickness unevenness and curling will become worse, and the appropriate molding range will become narrower. Further, curling of the final product cannot be prevented. Also, this (B)
It is preferable that both sides of the layer have the same thickness, but there is no problem as long as the thickness of one side is less than 2.5% of the total thickness. The composite film of the present invention has an elongation of 5% when heated.
It is preferable that it is below. The composite film of the present invention can be unstretched, stretched (uniaxially,
Although it may be any type of film (biaxial), an unstretched film is preferable in order to further improve moldability and productivity. The term "unstretched film" refers to a film whose longitudinal refractive index (N _MD ) and transverse refractive index (NT _TD ), as measured by Atsube's refractometer, exhibit the following relationship. 0.007≧｜N _MD −N _TD |≧0 The film of the present invention is a mixture of polypropylene and one or more specific resins as described above, but other resins may be further added to these resins. If the amount is 100% by weight of the entire added resin
It is desirable that the content is less than 20% by weight, preferably less than 15% by weight. Other resins include polyolefins other than polypropylene, petroleum resins containing polar groups, and terpene resins containing polar groups. The thickness of the composite film of the present invention is not particularly limited, but is 50 to 600 μm, preferably 100 to 600 μm.
A thickness in the range of 400 μm is desirable. Furthermore, it is desirable that the crystallinity is 50% or more, preferably 60% or more. The press-through pack of the present invention is made by forming a film into the shape of a tablet or capsule, inserting the tablet or capsule, etc., and pasting aluminum foil. A package whose contents can be removed by tearing the foil. Further, this molding includes air pressure molding, vacuum molding, plug molding, and the like. This PTP packaging is mainly used for packaging pharmaceuticals and foods. Next, a method for manufacturing the film of the present invention will be explained. Specific resins are added to polypropylene for the (A) layer and (B) layer, and the polymers for the (A) layer and (B) layer are melt-extruded using two extruders.
Discharge from the nozzle so that layer (B) is laminated on both sides of the layer. At this time, the resin is discharged at a maximum temperature not exceeding 240°C, preferably at a temperature of 180 to 220°C. This molten sheet is subsequently cast on a cooling drum, in a water bath or on calender rolls (metal rolls nipped together). At this time, the temperature of the cooling drum, water tank or calender roll is preferably in the range of 10 to 130°C, preferably 20 to 120°C. Furthermore, elongation during heating can be easily controlled by appropriately adjusting the slit width of the die and the take-up speed. In addition, in the case of calender rolls, it can be easily controlled by adjusting the width of the roll slits. Furthermore, the film of the present invention may be subjected to a corona discharge treatment in an atmosphere of air, carbon dioxide gas, nitrogen gas, etc. to increase the surface tension to about 40 dyne/cm or more to improve printability and the like. The present invention is not necessarily limited to this manufacturing method; for example, as a three-layer method, (A)
Each of (B) may be individually made into a film and bonded together. [Effects of the Invention] The present invention includes a polypropylene film having a three-layer structure, in which each layer contains a specific amount of a specific resin, and the thickness ratio of layer (B) to the total thickness is within a certain range. By doing so, the following excellent effects are produced. That is, (1) It exhibits excellent barrier properties with a water vapor permeability of 1.0 (g/m ² , day/per 250 μm sheet) or less, and exhibits excellent barrier properties even after molding. (2) The following excellent moldability can be obtained. Wide suitable temperature range for molding and excellent workability. A molded product with excellent shapeability, thickness unevenness, and transparency can be obtained. It does not curl even after molding. (3) The following excellent processing suitability can be obtained. It has excellent Γ slit line workability and punching properties, and does not leave any whiskers or the like due to poor punching. ●It has excellent sealing power with Al foil and expands the range of appropriate sealing. (4) No curling occurs in the final product (formed, filled with contents, laminated with Al foil, processed with slit lines, and punched out). This also facilitates automatic stacking and packaging. In addition, the measurement method and evaluation method of each characteristic in this invention are demonstrated. (1) Water vapor transmission rate is 40 according to JIS Z-0208.
g/ ^m2・day/250μ as measured at °C and 90%RH
Expressed in m units. However, after molding, g/ ^m2・
Expressed in days/sheets. (2) Intrinsic viscosity [η] is measured in tetralin according to ASTM D 1601. (3) For the stereoregularity index, see Example 1. (4) The moldability was determined by molding the polypropylene film of the present invention into a No. 3 capsule (long axis 17 mm, short axis 7.5 mm, depth A 6.5 mm capsule shape) which was fed and molded at a speed of 5.0 m/min was evaluated in the following items. The appropriate molding range was tested by changing the molding temperature from 115 to 140°C in 5°C increments at a constant molding speed of 5 m/min. Items with a mold fixation of over 90% in a temperature range of 15°C or higher have a wide range of suitable molding and are marked with an ○. (All below are shown in the range of over 90%). Temperatures above 5°C and below 15°C are within the range that can be used for production purposes, and are marked with a △. Furthermore, temperatures below 5°C were judged to be unusable because a slight variation in conditions would result in poor moldability, and were marked with an x mark. The above mold determination was evaluated using the ratio S = (l/l ₀ ) x 100 between the length l of the long axis of the ceiling of the PTP-molded capsule and the length l ₀ of the long axis of the molding die. It is something. Regarding thickness unevenness, cases in which the molded capsule-shaped part shows complete netting phenomenon are indicated by an x mark, indicating poor formability, cases with slight netting are indicated by a △ mark, and cases in which no necking is observed at all are indicated as good. It is indicated with an ○ mark. Transparency after molding is expressed as turbidity, and if the turbidity is 10% or more higher than before molding, the transparency is poor and the product value decreases, making it unusable. Items in good condition are marked with a circle. Note that this turbidity was measured using Nippon Precision Optical Co., Ltd., SEP-H-2 type, 550m.
It was measured at a wavelength of μ. Curls after molding are cut to a size of 49 mm in length and 85 mm in width, and those with no curl in any direction are marked as good, and those with curls of 5 mm or more in any direction are marked with a circle. This is indicated by an x because post-processability deteriorates.
The middle point is indicated by a △ mark. (5) Processing suitability includes slit line processing, punching properties,
Evaluation was made based on bondability with Al foil. Slit wire processing should be done up to 2/3 of the total thickness.
The evaluation was based on the ease of cutting this part. Items that can be easily cut by hand are marked as good and marked with an ○.
Items that can be cut by hand but with considerable resistance are marked with a △ mark, and items where the cut portion extends beyond the slit line area and are cut are marked as a processing defect and are marked with an x mark. The punching property was evaluated by the way the sheet was cut using the above-mentioned molding machine. Evaluation was made based on whether or not there were whiskers on the punched end face. The adhesion properties of the Al foil were determined based on the appropriate heat-sealing range and heat-sealing force. The upper limit of heat sealing temperature is possible up to 200℃, and the range was determined only by the lower limit. The temperature range is shown in which a heat sealing force of 500 g/15 mm or more can be obtained. Items that can maintain a temperature range of 20℃ or higher are marked with an 〇, and 5℃
The following items may cause problems during actual sealing.×
Indicated with a mark. This middle point is indicated by a △ mark. (6) After molding, the final product, Curl, is filled with the contents, processed with slit lines, and punched out for each shot.The size is 49 mm long and 85 mm wide, and there are molded parts for 10 capsules. evaluated. For evaluation, if the flat surface side to which the Al foil is bonded does not curl in any direction, it is considered good and is marked with an ○.
Items with curls as described above have a poor appearance and are difficult to package, so they are marked with an "X". In addition, the intermediate value is indicated by a △ mark. (7) The elongation (l) during heating is 1 in the longitudinal direction of the film.
30cm length sampling with cm width, 20cm in longitudinal direction
Mark the length (l ₁ ) of . Attach a weight of 3g to this sample,
Treat at a temperature of 120° C. for 15 minutes and measure the length (l ₂ ) after treatment. This is expressed using the following formula. Elongation upon heating (l)=(l ₁ −l ₂ )/l ₁ ×100 [%] [Example] Hereinafter, embodiments of the present invention will be described based on Examples. However, it is not limited to this. Examples 1 to 6, Comparative Examples 1 to 4 Polypropylene raw material (“Mitsui Noblen” JS-
1429, manufactured by Mitsui Toatsu Chemical Co., Ltd., [η] = 2.25, II = 97
%), specific resin “Escoretsu” 5320
(A) layer in which 20wt% of Etsuso Chemical (Etsuso Chemical Co., Ltd.) was added, and (B) layer in which the specific resin "Escoretsu" 5320 was added to the same polypropylene raw material in varying amounts as shown in Table 1. A film was formed as follows. The raw materials for layer (A) and layer (B) are supplied to separate extruders, melted at 200℃, and coextruded to form a three-layer composite film consisting of (B)/(A)/(B) (thickness Composition ratio=
25/200/25 μm), extruded through a 2.0 mm die slit, and cast onto a casting drum maintained at 110°C at a casting speed such that the elongation during heating was 5% or less. Each film
The discharge amount was adjusted to 250 μm. In addition,
Only in Comparative Example 1, the (A) layer was formed as a single layer, and the (B) layer was not discharged. The quality of the obtained film is shown in Table 1.
From this table, unless the specific amount of resin added to layer (B) is within the range of 0.5 to 7.0 wt%, excellent moldability, processability, and final product appearance (curl) cannot all be satisfied. A film with only a single layer (A) to which only a specific resin is added has excellent water vapor barrier properties, moldability, and transparency, but does not improve haze deterioration after molding or curl in the final product. I understand that. However, in II, the film was extracted with boiling methyl alcohol for 6 hours and then vacuum dried at 60°C for 6 hours. A sample of weight W was taken from this, extracted with boiling N-heptane for 6 hours, washed thoroughly with acetone, dried under vacuum at 60°C for 6 hours, and the weight of the sample was determined.
Find W′ using the following formula. II=(W′/W)×100[%]

[Table] Examples 7 to 11, Comparative Examples 5 to 7 Polypropylene raw material (“Mitsui Noblen” FO-
850, manufactured by Mitsui Toatsu Chemical Co., Ltd., [η] = 1.85, II = 97%)
layer (A) with 25wt% of specific resin “Alcon” P125 (Arakawa Chemical Industry Co., Ltd.) added, and a specific resin “Alcon” P125 added to the same polypropylene raw material.
A three-layer structure as shown in Table 2 was formed from layer (B) containing 3.0 wt% of . The raw materials for layer (A) and layer (B) are supplied to separate extruders, melted at 220°C, and coextruded to form a three-layer composite film consisting of (B)/(A)/(B). Extruded from 1.0mm slit, 80
Nip cast with calender rolls kept at ℃. The thickness composition ratio changes depending on the discharge amount, and the total thickness also changes.
The discharge amount was adjusted to 250 μm. In addition, the nip pressure of the calender rolls was adjusted so that the elongation during heating was 5% or less. The quality of the obtained film is shown in Table 2. From this table, it can be seen that (B) a product that satisfies each property can only be obtained when the thickness structure of the layer is within a certain range.

[Table] I understand. Examples 12-13, Comparative Examples 8-9 Polypropylene raw material (“Mitsui Noblen” FO-
100, manufactured by Mitsui Toatsu Chemical Co., Ltd., [η] = 2.25, II = 97%)
In contrast, the types of resins added were varied as shown in Table 3, and 10 wt% of each was added to the (A) layer. For the polypropylene of layer (B) (“Mitsui Noblen” J3H, manufactured by Mitsui Toatsu Chemical Co., Ltd., [η] = 1.45 II = 97%), the types of additive resins were changed as shown in Table 3.
1.0wt% of each was added. The raw materials for layers (A) and (B) are
Each is fed to a separate extruder and melted at 200℃.
Co-extrusion of three-layer composite film consisting of (B)/(A)/(B) (thickness composition ratio = 25/200/25 μm), slit
The material extruded from 2.5 mm was cast onto a casting drum kept at 80°C. In order to adjust the film thickness to 250 μm, the discharge amount was adjusted. The quality of the obtained film is shown in Table 3. From this table, if the resin to be added is not a specific resin,
Water vapor barrier properties are poor, and curling is similarly poor. In other words, it can be seen that the film cannot be used as a PTP packaging film unless a specific resin is added to either layer.

[Table] Examples 14 to 18, Comparative Examples 10 to 11 Polypropylene raw material (“Mitsui Noblen” JS/
1429, manufactured by Mitsui Toatsu Chemical Co., Ltd., [η] = 2.25, II = 97
(A) layer in which the specific resin "Escolets" 5320 was added to the same polypropylene raw material in varying amounts as shown in Table 4.
A film was formed as follows, consisting of layer (B) to which 3.0 wt% was added. The raw materials for layer (A) and layer (B) are supplied to separate extruders, melted at 200℃, and coextruded to form a three-layer composite film consisting of (B)/(A)/(B) (thickness Composition = 10/
230/10 μm), extruded through a 0.5 mm die slit and nip-cast using a calendar roll kept at 95°C. The nipping force was adjusted so that the elongation during heating was 5% or less, and the discharge rate was adjusted so that the film thickness was 250 μm. The quality of the obtained film is shown in Table 4.
From this table, unless the amount of the specific resin added to layer (A) is 8wt% or more, excellent water vapor barrier properties will not be obtained, and moldability and curling of the final product will also deteriorate.
Cannot be used as PTP packaging material. Furthermore, if the amount added exceeds 40%, the film becomes brittle and cannot be molded. I understand that.

【table】

Claims (1)

[Claims] 1 In a composite film in which the (B) layer is laminated on both sides of the (A) layer, the (A) layer contains 92 to 60 wt% of polypropylene,
One or more petroleum resins that do not contain polar groups are 8~
The layer (B) is a layer in which 40 wt% of polypropylene is mixed with 99.5 to 93 wt% of polypropylene and 0.5 to 7 wt% of one or more petroleum resins that do not contain polar groups, and (B) A polypropylene composite film for a press-through pack, characterized in that the total thickness of the layers is 5 to 30% of the thickness of the composite film.