JPH072408B2 - Polypropylene sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention is a press-through pack package (hereinafter abbreviated as PTP) used for packaging tablets, capsules, etc. of pharmaceutical products.
The present invention relates to a polypropylene sheet used for.

[Prior Art] Conventional polypropylene sheets have not been used for PTP because they are inferior to PVC sheets in terms of their transparency and thermoformability.However, polypropylene and petroleum resin have recently been added to them to improve transparency and transparency. It has been disclosed that the wettability is improved (for example, JP-A-59-143613 and JP-A-60-
No. 163949 publication).

[Problems to be solved by the invention]

However, the conventional polypropylene sheet has a narrow molding temperature range in a PTP molding machine, and the petroleum resin bleeds out from the sheet surface to cause stickiness on the surface during molding, resulting in poor transparency and poor appearance. It was not preferable.

An object of the present invention is to provide a polypropylene sheet suitable for PTP packaging, which has a sufficiently wide molding temperature range at the time of molding and has good transparency, moisture resistance, and moldability.

[Means for solving problems]

The present invention is a laminated sheet having a three-layer constitution of B layer / A layer / B layer, wherein A layer is a petroleum resin containing no polar group or a terpene resin containing no polar group with respect to 70 to 90 parts by weight of polypropylene resin. 30 to 10 parts by weight of at least one of the above is mixed, the layer B is a polyolefin resin layer having a polyorganosiloxane chain in the side chain, and the thickness of the layer A is 60 to 60 times the thickness of the three layers. It features 95% polypropylene sheet.

The polypropylene applied to the layer A of the present invention is not particularly limited, but the isotactic index (II) is 90% or more, and the intrinsic viscosity [η] measured at 135 ° C. in tetralin is 0.8 to 4.0. dl / g, especially in the range of 1.0 to 2.2 dl / g is desirable.

A second component other than propylene, such as ethylene and butene, may be copolymerized, but a homopolymer is preferable for the purpose of the present invention, but may be copolymerized within a range that does not significantly impair the crystallinity. Good. Of course, a known crystal nucleating agent, an antioxidant, as an additive to the polypropylene,
You may add a heat stabilizer, a slip agent, an antistatic agent, an antiblocking agent, a filler, a viscosity modifier, a coloring preventive agent, etc.

The petroleum resin or terpene resin to be added preferably has a glass transition temperature Tg of 50 ° C. or higher, more preferably 70 ° C.
These are those which do not substantially contain a polar group such as a hydroxyl group, a carboxyl group, a halogen group, a sulfone group, or a double bond, that is, an unsaturated bond. That is, the hydrogenation rate is 90% or more, preferably 95% or more. Typical petroleum resins include alicyclic petroleum resins represented by cyclopentadiene series, for example, [trade name "ESCOLETS" 5000 series (Exxon Chemical)].

A typical terpene resin is (C ₅ H ₈ ) n (n
Is a hydrocarbon-based compound having a composition of 2 to 30), and hydrogenation rate is obtained by adding hydrogen to pinene, curene, mylene and the like.
90% or more.

It is necessary that the layer A contains 30 to 10 parts by weight, preferably 25 to 15 parts by weight, of at least one kind of petroleum resin or terpene resin, based on 70 to 90 parts by weight of the polypropylene resin. . If the amount of the added resin is less than 10 parts by weight, the moisture permeability will be poor, and if it exceeds 30 parts by weight, the extrusion moldability and the
Moldability of PTP deteriorates, which is not preferable.

Layer B is formed of a polyolefin resin having a side chain having a polyorganosiloxane chain. The polyorganosiloxane chain has a linear structure with a degree of polymerization n represented by [R ₂ SiO] n of 3 or more (n can be calculated by an NMR spectrum), and the substituent R bonded to the silicon atom is A phenyl group (which may be a derivative such as a chlorophenyl group) having 1 to 20 carbon atoms, a polyoxyalkylene group, However, R ₁ is a hydrocarbon having 1 to 20 carbon atoms, R ₂ is hydrogen or a hydrocarbon having 1 to 20 carbon atoms, x is 1 to 5, y is a group represented by an integer of 2 to 50, a hydroxyl group, an amino group. , Or a carboxyl group, etc., or may be used in combination of two or more kinds. However, since substituents such as a hydroxyl group, an amino group and a carboxyl group are highly reactive, if the number of reactive substituents increases, crosslinking / gelation will proceed and fish eyes will be unfavorable. The gel fraction of the resin applied to the layer (B) is preferably 1% or less, more preferably 0.3% or less,
Most preferably, it is 0.1% or less. The number of reactive substituents is preferably 1 or less per 10 silicon atoms, and 1 per 50 silicon atoms.
Or less is more preferable (the number of substituents on the silicon atom is
The degree of polymerization n can be calculated from the NMR spectrum)
5 or more is preferable, 10 or more is more preferable, 50 to 20
0000 is the most preferable.

The polyolefin resin to which the side chain having a polyorganosiloxane chain is bonded may be any of polyethylene, polypropylene, polybutene, and copolymers thereof. However, the adhesive strength between the layer A and the layer, heat resistance, etc. To polypropylene and their copolymers are particularly preferred. The content of the polyorganosiloxane chain in the layer B is preferably 0.1 wt% to 15 wt% and more preferably 1 to 10 wt% from the viewpoint of moldability and transparency in a molding machine.

As a method for introducing a side chain having a polyorganosiloxane chain into a polyolefin, a polyolefin resin does not have a reactive substituent, so maleic anhydride or the like is grafted, and after the reactive substituent is introduced, the reactivity is improved. It is necessary to react the polyorganosiloxane. in this case,
When the number of reactive substituents in the reactive polyorganosiloxane is large, as described above, crosslinking / gelation is likely to occur and fish eyes may increase. Therefore, the modified polyorganosiloxane preferably has a reactive substituent at both ends of the chain or only one end.

In the B layer, known additives such as a heat stabilizer, an antioxidant, a crystal nucleating agent, an antistatic agent, an antiblocking agent, and a light stabilizer may be used in the range not impairing the characteristics of the present invention. Good.

Of the constituent thicknesses of layer B / layer A / layer B of the laminated film of the present invention, the proportion of the thickness of layer A is 60 to 95 of the total thickness (three layers).
%, Preferably 70-90%.

When it is less than 60%, the moisture vapor resistance is deteriorated. On the other hand, 95
If it exceeds%, the moldability and the surface become sticky during thermoforming, the transparency of the sheet is deteriorated, and the appearance is poor.

It is preferable that the thicknesses of the B layers on both sides are substantially the same, but if the thickness on one side is at least 5 μm or more, the thickness on both sides may be different. The total thickness is not particularly limited, but it is preferably about 50 μ to 500 μ.

Next, a method for producing the polypropylene sheet of the present invention will be described.

A specific petroleum resin or terpene resin was supplied to polypropylene in the main extruder and melted and uniformly mixed at a resin temperature not exceeding 260 ° C, preferably at a temperature of 200 to 230 ° C. On the other hand, a polyolefin resin having a polyorganosiloxane chain in the side chain is supplied to the auxiliary extruder and melted under the same temperature conditions as the main extruder, and the polymers of both extruders are layer B / A / B in the film forming die. The sheet of the present invention can be obtained by casting the above three-layer structure on a cooling drum, casting in a water tank, or by calender rolls (nipped by metal rolls).

If the resin temperature exceeds 260 ° C., preferably 250 ° C., not only a sheet having excellent properties intended by the present invention cannot be obtained, but also the added petroleum resin or terpene resin is thermally decomposed or scattered, and Polyorganosiloxane-containing polyolefin resin is not preferable because it easily crosslinks and gels.

Further, the laminating method may be a method in which the A layer and the B layer are individually formed into a sheet and then laminated.

Further, the sheet of the present invention is subjected to corona discharge treatment in an atmosphere of air, carbon dioxide gas, nitrogen gas or the like to have a surface tension of 40.
The surface adhesiveness such as printability can be improved by increasing it to about dyne / cm or more.

The method of measuring the characteristic value and the method of evaluating the effect of the present invention are as follows.

(1) Water vapor permeability is 40 ° C, 9 according to JIS Z-0208.
Value measured at 0% RH and expressed in g / m ² · day / sheet unit.

(2) Haze is a value measured according to JIS K-6782.

(3) Intrinsic viscosity [η] is 135 according to ASTM D-1601
Value measured in tetralin at ℃ and expressed in dl / g.

(4) I · I is expressed by the remaining amount (wt%) of boiling n-peptane extracted.

(5) For the glass transition temperature, set 10 mg of a sample to a scanning calorimeter DSC-II type (manufactured by Perkin Elmer) and start from -20 ° C at a heating rate of 40 ° C / min under a nitrogen stream. Let the thermograph write the temperature Tg, which is the arithmetic mean of the temperature at which the endothermic peak deviates from the baseline and the temperature at which it returns.

(6) The molding test was carried out with a PTP molding machine (CKD FBP-V3), and the moldability was visually judged such as the stickiness of the surface and the curl state after the sheet with the Al foil.

〔Example〕

 The present invention will be described based on examples.

Example 1 Polypropylene ([η] = 1.9, I · I = 97%) was mixed with hydride of dicyclopentadiene (“ESCOLETS” 5320 manufactured by Exxon Chemical Co., Tg = 75 ° C.) as a specific petroleum resin.
The 0% by weight blended raw material was fed to the 65mmφ main extruder (A layer), and the 40mmφ sub-extruder had a molecular weight of 1000.
Polyorganosiloxane of 3 via maleic anhydride
% Polypropylene introduced into the side chain ([η] = 1.6,
I · I = 97%) was supplied (layer B). The temperature of both extruders
After the temperature was set to 230 ° C and a three-layer structure of B / A / B was formed in the die, it was cast on a casting drum kept at 62 ° C to obtain an unstretched sheet.

Example 2 An unstretched sheet was obtained in exactly the same manner as in Example 1 except that the petroleum resin "ESCOLETS" added to the layer A was 25% by weight.

The thickness composition of the obtained sheet was 25 μm / 200 μm / 25 μm, and its characteristics are shown in Table 1. The molding temperature range was wide enough, and the transparency and humidity resistance after molding were small and excellent PTP. Got

Example 3 The terpene resin “Clearon” P was added to the petroleum resin added to the layer A.
-115 (Yasuhara Yushi Kogyo Co., Ltd.) 20% by weight, thickness composition 15μm
An unstretched sheet was obtained in the same manner as in Example 1 except that the thickness was / 220 μm / 15 μm. The characteristics are shown in Table 1. Even if a terpene resin is used as a petroleum resin, the molding temperature range is sufficiently wide, and the transparency and moisture resistance after molding are small and PT is small.
It was an excellent P packaging material.

Comparative Examples 1 to 2 B layer was made of polypropylene homopolymer ([η] = 1.6, I ·
I = 97%) (Comparative Example 1), and Example 1 except that the laminated film of the B layer was eliminated and the single layer sheet of the A layer (Comparative Example 2) was used.
A sheet was obtained similarly to. The characteristics are shown in Table 1,
It is clear that unless a polyolefin resin having a polyorganosiloxane chain is used in the B layer, the molding temperature range is narrowed and the transparency is lowered or the appearance after molding is significantly deteriorated.

Comparative Examples 3 to 4 Non-stretched sheets were obtained in exactly the same manner as in Example 1 except that the concentration of the petroleum resin "ESCOLETS" 5320 in the A layer was changed to 8% by weight and 40% by weight. The characteristics are shown in Table 1. When the specific petroleum resin deviates from the predetermined addition amount, the moisture resistance,
The molding temperature range, the appearance after molding, etc. are significantly deteriorated.

Comparative Example 5 An unstretched sheet was obtained in the same manner as in Example 1 except that the thickness ratio of B layer / A layer / B layer was 60 μm / 130 μm / 60 μm. The characteristics are shown in Table 1, but when the thickness ratio deviates from the specific range, the molding temperature range becomes narrow.

Comparative Example 6 The procedure of Example 1 was repeated except that the petroleum resin "ESCOLETS" 5320 used in Example 1 was replaced with gum rosin (Ester gum A, manufactured by Arakawa Chemical Co., Ltd.). The characteristics are shown in Table 1. As a result, it has a polar group (gum rosin has --COO
It can be seen that when H) resin is added, the moisture permeability is large and the moisture resistance is poor.

EFFECTS OF THE INVENTION The present invention uses a polypropylene resin containing a specific amount of a specific petroleum resin or a terpene resin as a base layer (A layer), and laminates a polyolefin resin layer having a polyorganosiloxane chain on both sides thereof. By using a sheet, (1) the molding temperature range on the PTP molding machine is wide and it is easy to process.

(2) As a result, since the thickness of the curved portion after molding has a sufficient thickness, the decrease in moisture resistance after molding is small.

(3) It has excellent adhesiveness to Al foil and can be bonded at a lower sealing temperature than before, so that curling of molded products is eliminated and PTP with an excellent appearance can be obtained.

(4) Water vapor transmission rate is 0.8 (g / m ² · day /
Sheet) shows the following excellent barrier properties.

(5) Excellent transparency.

It could be an excellent sheet such as.

Claims (1)

[Claims] 1. A laminated sheet having a three-layer structure of B layer / A layer / B layer, wherein the A layer is a petroleum resin containing no polar group or a terpene containing no polar group with respect to 70 to 90 parts by weight of a polypropylene resin. At least one resin is mixed in an amount of 30 to 10 parts by weight, the layer B is a polyolefin resin layer having a polyorganosiloxane chain in the side chain, and the thickness of the layer A is 60 times that of the three layers. ~ 95% polypropylene sheet.