JP6885700B2 - Adhesive composition for sealing and press-through pack packaging - Google Patents

Description

The present invention is a heat seal coat (heat adhesive) for adhering an aluminum foil as a lid material and a bottom material film in a press-through pack package (hereinafter referred to as PTP) using aluminum foil, which is a packaging form for pharmaceuticals and foods. Layer) seal adhesive composition.

As one of the packaging forms for pharmaceuticals and foods, a PTP package having a bottom material and a lid material is known. The PTP package is configured to take out the contents by breaking the lid material by applying a force from the outside of the bottom material toward the lid material to the stored contents. The lid material of the PTP package is composed of a lid material film and a heat seal layer. As the lid film, aluminum foil, glassine paper, a stretched film of a thermoplastic resin, etc., which are excellent in the property of being easily torn by extruding the contents (press-through property), and the like are currently used (for example, Patent Documents). 1).
When the lid film is made of aluminum foil, fragments of the aluminum foil may be generated, and it has been reported that the aluminum foil fragments are accidentally swallowed together with the chemicals. In addition, there are complaints that it is difficult for vulnerable people such as elderly people and infants to take out the drug from PTP due to lack of muscle strength to push out the drug. Furthermore, since hospitals and the like handle dozens to hundreds of kinds of drugs a day, there is a demand for easily taking out a large amount of drugs at one time.
For the purpose of solving the above problems, a resin film is attached to one side of the aluminum foil, and a lid material having an easy-peel heat adhesive layer on the other side and a container having a large number of pockets formed a press-through function. An invention relating to a press-through pack package having both an easy peel function and an easy peel function has been proposed (for example, Patent Document 2).

However, in the resin composition of the heat-adhesive layer used, the interfacial peeling between the aluminum foil of the lid material and the bottom material film is non-uniform, so when the lid material is peeled off, it adheres properly before opening. There are still problems that the proof that it was used (evidence) cannot be obtained, the adhesive strength becomes unstable due to fluctuations in the adhesive temperature conditions due to the speeding up of the production line, and the adhesive strength decreases when the amount of heat applied decreases. I haven't been able to overcome it.

In many cases, a resin film is attached to the aluminum lid material, and even under conditions of poor thermal conductivity to the heat sealant layer, low-temperature heat-sealing performance in a lower temperature range can be maintained, and the bonding temperature conditions are also good. Stable adhesive strength even if shaken, uniform cohesive peeling state that responds to the above (evidence) when the lid material is peeled off, stable adhesiveness over time under moist heat resistant conditions that reproduce the deterioration of the storage environment and changes over time Is required to be retained.

Japanese Unexamined Patent Publication No. 2015-093727 JP-A-2010-254315

The object of the present invention is that the adhesive temperature dependence is lessened, it is possible to leave a uniform adhesion mark of coagulation peeling at the time of opening peeling, and the adhesive force does not decrease due to hydrolysis by moisture even under moist heat resistant conditions. The present invention provides an adhesive composition for a seal having excellent storage stability.

As a result of diligent research, the inventors have come to solve the above-mentioned problem by containing three kinds of copolymers.

That is, the present invention is a sealing adhesive composition containing a (meth) acrylic copolymer (A), an acid group-containing vinyl chloride vinyl acetate-based copolymer (B), and a vinyl acetate copolymer (C). Regarding.

Further, the (meth) acrylic copolymer (A) is 35 to 90% by mass with respect to 100% by mass of the solid content in the sealing adhesive composition of the present invention, and the acid group-containing vinyl chloride vinyl acetate-based copolymer ( B) is 5 to 25% by mass, and the vinyl acetate copolymer (C) is 5 to 40% by mass.

Further, in the present invention, the vinyl acetate copolymer (C) is a vinyl acetate / ethylene copolymer, and the content of vinyl acetate as a copolymerization component is 5 to 50% by mass, which is a sealing adhesive. Regarding the composition.

The present invention also relates to a sealing adhesive composition in which the copolymerization component of the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) contains an acid component of maleic acid or fumaric acid.

Furthermore, the present invention relates to a blister pack package in which a sealing adhesive composition is applied to at least one side of an aluminum foil and bonded to a film.

According to the present invention, the adhesion temperature dependence is lessened, it is possible to leave a uniform adhesion mark of agglomeration peeling at the time of opening and peeling, and the adhesive strength does not decrease due to hydrolysis by moisture even under moist heat resistant conditions. It is possible to provide an adhesive composition for sealing excellent in quality.

It is an illustration drawing which shows the cross-sectional view of the blister pack package (the dashed ellipse shows a tablet). It is an illustration figure at the time of opening the blister pack package using the adhesive composition for a seal of this invention.

The sealing adhesive composition of the present invention contains three components: a (meth) acrylic copolymer (A), an acid group-containing vinyl chloride vinyl acetate-based copolymer (B), and a vinyl acetate copolymer (C). It is characterized by containing.

Here, the (meth) acrylic copolymer (A) and the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) are compatible with each other, but the vinyl acetate copolymer (C) is a (meth) acrylic copolymer. It is preferable that neither the polymer (A) nor the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) is compatible.
Further, under low-temperature heat-sealing conditions, the (meth) acrylic copolymer (A) adheres well to the polyvinyl chloride (PVC) base material of the PTP bottom material, and is an acid group-containing vinyl chloride vinyl acetate-based copolymer (B). ) Adheres well to the aluminum lid material. As for (B), by adding an acid group, the adhesion to the aluminum lid material is further improved.
On the other hand, under high-temperature heat-sealing conditions, both the (meth) acrylic copolymer (A) and the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) adhere well to the bottom polyvinyl chloride (PVC) substrate. In addition, the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) adheres well to the aluminum lid material.
From the above, it is important to maintain the mutual characteristics of the three components (A), (B) and (C) in a well-balanced manner. In the case of an adhesive consisting of a mixture of only two types of vinyl chloride-based copolymer (B) contained in vinyl chloride, delamination between the "bottom material and heat seal layer" or "aluminum lid material and heat seal layer" at the time of opening, or Non-uniform cohesive peeling in the heat seal layer is likely to occur.

The sealing adhesive composition of the present invention contains three components: a (meth) acrylic copolymer (A), an acid group-containing vinyl chloride vinyl acetate-based copolymer (B), and a vinyl acetate copolymer (C). By mixing, the vinyl acetate copolymer (C), which is incompatible with both the (meth) acrylic copolymer (A) and the acid group-containing vinyl chloride vinyl acetate-based copolymer (B), forms a matrix in the formed film. Since it is formed and finely dispersed, it is possible to obtain a stable adhesive force that is not easily affected by the bonding temperature conditions by causing macroscopically uniform cohesive failure.

The (meth) acrylic copolymer (A) used in the sealing adhesive composition of the present invention includes
A (meth) acrylic copolymer containing an acetoacetyl group can also be used. Examples of the methacrylic monomer that can be used for synthesizing the methacrylic copolymer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and butyl methacrylate. (Hexyl methacrylicate), 2-ethylhexyl methacrylate (2-ethylhexyl methacrylicate), cyclohexyl methacrylate, benzyl methacrylate (benzyl methacryliclate), dimethylaminoethyl methacrylate, dimethylaminoethyl methacrylate. (Hydroxypropyl monomer), glycidyl methacrylate and the like can be mentioned.

Among them, a copolymer with methyl methacrylate using butyl methacrylate as a methacrylic monomer is more preferable, and examples of a commercially available product include DEGALAN P24 manufactured by EVONIK Industries.

As the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) used in the sealing adhesive composition of the present invention, it is preferable to use one having a weight average molecular weight of 5,000 to 50,000. Adhesion to the aluminum lid material is further improved by containing the acid group. Maleic acid or fumaric acid is preferable as the acid group.
Further, in obtaining such an acid group-containing vinyl chloride vinyl acetate copolymer (B), it is preferable to add 5 to 40% by mass of the vinyl acetate monomer, and more preferably 10 to 20% by mass.
If the amount of vinyl acetate compounded is too large, the blocking phenomenon is likely to occur. On the contrary, if the amount of vinyl acetate compounded is too small, the (meth) acrylic copolymer (A) and the vinyl acetate copolymer (C) used in combination are used together. The compatibility is lowered, and the solubility in the solvent used when coating on the substrate is lowered, so that coating cannot be performed.

Examples of the vinyl acetate copolymer (C) used in the sealing adhesive composition of the present invention include vinyl acetate / ethylene copolymer, and the content of the vinyl acetate component, which is a copolymerization component, is 10 to 50. It is preferably by mass%, more preferably 15 to 50% by mass, and even more preferably 40 to 50% by mass.

Three components, a (meth) acrylic copolymer (A), an acid group-containing vinyl chloride vinyl acetate-based copolymer (B), and a vinyl acetate copolymer (C) used in the sealing adhesive composition of the present invention. The content ratio of the (meth) acrylic copolymer (A) was 35 to 90% by mass with respect to 100% by mass of the solid content in the sealing adhesive composition against the background of the above paragraphs [0017] and [0018]. The acid group-containing vinyl chloride vinyl acetate-based copolymer (B) is preferably in the range of 5 to 25% by mass, and the vinyl acetate copolymer (C) is preferably in the range of 5 to 40% by mass.
The (meth) acrylic copolymer (A) is more excellent in adhesiveness under low temperature heat sealing conditions of 140 ° C., and is more preferably 55 to 80% by mass of the total solid content of the present adhesive composition. preferable. The acid group-containing vinyl chloride vinyl acetate-based copolymer (B) also has an excellent adhesiveness under low-temperature heat-sealing conditions of 140 ° C., and is 10 to 20% by mass of the total solid content of the adhesive composition. Is more preferable. Further, the vinyl acetate copolymer (C) is more preferably 10 to 35% by mass of the total solid content of the present adhesive composition in that it is excellent in adhesiveness under high temperature heat sealing conditions of 180 ° C.

If the amount of the (meth) acrylic copolymer (A) exceeds 90% by mass, the adhesiveness between the aluminum lid material and the heat-seal layer is lowered, and delamination is likely to occur between them.
When the amount of the (meth) acrylic copolymer (A) is less than 35% by mass, the adhesiveness of the bottom material to the polyvinyl chloride (PVC) base material is lowered, and non-uniform cohesive peeling is likely to occur.
If the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) exceeds 25% by mass, the adhesiveness decreases under low-temperature heat-sealing conditions, and conversely, the adhesiveness becomes too high under high-temperature heat-sealing conditions. There is a tendency, and the adhesive strength is too strong, so that the heat seal layer may be unevenly aggregated and peeled off at the time of opening.
When the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) is less than 5% by mass, the adhesiveness with the aluminum lid material is lowered, and delamination between the aluminum lid material and the heat seal layer is likely to occur.
If the vinyl acetate copolymer (C) exceeds 40% by mass, the compatibility of the adhesive composition is extremely deteriorated, and the phase is immediately separated, making coating difficult. Further, under high temperature heat sealing conditions, the adhesion between the aluminum lid material and the heat sealing layer is particularly hindered, and delamination is likely to occur between them.
When the vinyl acetate copolymer (C) is less than 5% by mass, delamination between the "bottom material and heat seal interlayer" or "aluminum lid material and heat seal interlayer" or non-uniform cohesive peeling in the heat seal layer occurs. Is easy to cause.

When actually applying the sealing adhesive composition of the present invention to a lid material, a (meth) acrylic copolymer (A) and an acid group-containing vinyl chloride vinyl acetate-based copolymer are used to improve the coating performance. The mixture of (B) and the vinyl acetate copolymer (C) is dissolved in an arbitrary solvent selected from toluene, methyl ethyl ketone and the like so as to have a solid content of 20% by mass before use.
Blocking inhibitors can also be used if desired. Examples of the blocking inhibitor include particle-based blocking inhibitors such as silica, calcium carbonate, calcium phosphate, talc, urethane beads, acrylic beads, melamine beads, and silicone beads, polyethylene wax (PE wax), fatty acid amide, fatty acid ester, and higher fatty acid. It is preferable to use an organic compound-based blocking inhibitor such as. The particle-based blocking inhibitor prevents blocking by forming irregularities on the surface of the heat seal layer and reducing the contact area between the surface of the heat seal layer and the back surface. On the other hand, the organic compound-based blocking inhibitor prevents blocking by bleeding out to the surface of the heat seal layer. Therefore, it is preferable to use a particle-based blocking inhibitor and an organic compound-based blocking inhibitor in combination. If a large amount of the organic compound-based blocking inhibitor is added, the adhesiveness is hindered and poor adhesion is likely to occur. Therefore, it is preferable to add only a small amount.

As a coating method for the lid material, for example, a bar coater, a gravure coating method, a roll coating method, a knife coating method, a kiss coating method, or the like can be used for coating. The amount of the coating film on the hard aluminum foil ^{is preferably 1 to 5 g / m 2} , and the drying conditions are preferably in the range of 120 to 200 ° C. for 5 to 100 seconds. Next, put the dried lid material on a PVC sheet of hard PVC at 120 to 200 ° C.
Adhere at a pressure of 0.3 MPa for 1 second.

Hereinafter, the present invention will be specifically described with reference to Examples. In the example, "part" and "%" are "parts by mass",
Represents "mass%" respectively.
The number average molecular weight and the weight average molecular weight (in terms of polystyrene) measured by GPC in the present invention were measured by using an HLC8220 system manufactured by Tosoh Corporation under the following conditions.
Separation column: Uses 4 _{TSKgelGMH HR-N manufactured by Tosoh Corporation.} Column temperature: 40 ° C. Moving layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow velocity: 1.0 ml / min. Sample concentration: 1.0% by weight. Sample injection volume: 100 microliters. Detector: Differential refractometer.
The glass transition temperature (Tg) was measured by the DMA method under the conditions of a temperature range of −80 to 450 ° C. and a temperature rise temperature of 10 ° C./min using a cooling device in a differential atmosphere.

[Preparation of adhesive for sealing]
As Example 1, 90 parts of a butyl methacrylate / methyl methacrylate copolymer (80/20 wt%) and a maleic acid-containing vinyl chloride / vinyl acetate copolymer (maleic acid 1 / vinyl chloride 84 / vinyl acetate 15 wt%) were added. Using 5 parts and 5 parts of vinyl acetate / ethylene copolymer (vinyl acetate amount is 41% by mass), 200 parts of toluene and 200 parts of methyl ethyl ketone so that the solvent content is 100 parts with respect to the total solid content of 20 parts. At the mixing ratio, the solid content was gradually added to the solvent while stirring at a rotation speed of 3000 mp at a temperature of 25 ° C. using a dispersion stirrer, and the mixture was stirred for 10 minutes to prepare a sealing adhesive.

Adhesives for sealing were prepared in the same manner for Examples 2 to 8 in Tables 1 and 2 and Comparative Examples 1 to 7 in Table 3. In Comparative Example 6, instead of the three types of copolymers used in the present invention, a mixture (50/50 wt%) of the amorphous polyester resin Byron 220 manufactured by Toyo Boseki Co., Ltd. and the polyester resin GK810 was used. In Comparative Example 7, the ethylene-based polymer CMPS VN503 manufactured by Mitsui-Dupont Polychemical Co., Ltd. was similarly mixed by the above-mentioned solvent dilution to prepare an adhesive for sealing. The numbers in Tables 1 and 2 indicate the solid content weight ratio.

・ブチルメタクリレート／メタクリル酸メチル共重合体（８０／２０ｗｔ％）、重量平均分子量１８０，０００、ガラス転移点（Ｔｇ）＝４３℃
・マレイン酸含有塩化ビニル／酢酸ビニル共重合体（マレイン酸１／塩化ビニル８４／酢酸ビニル１５ｗｔ％）、重量平均分子量１９，６００、ガラス転移点（Ｔｇ）＝７９℃
・酢酸ビニル／エチレン共重合体（酢酸ビニル量が４１質量％）、融点＝４０℃（ＤＳＣ）
・バイロン２２０／ＧＫ８１０：東洋紡（株）社製非晶性ポリエステル樹脂、バイロン２２０（数平均分子量３，０００、Ｔｇ＝５３℃）とバイロンＧＸ８１０（数平均分子量６，０００、Ｔｇ＝４６℃）の５０／５０ｗｔ％の混合物
・ＣＭＰＳ ＶＮ５０３：三井・デュポンポリケミカル（株）社製エチレン系ポリマー
ビカット軟化温度＝５３℃

Butyl methacrylate / methyl methacrylate copolymer (80/20 wt%), weight average molecular weight 180,000, glass transition point (Tg) = 43 ° C.
-Maleic acid-containing vinyl chloride / vinyl acetate copolymer (maleic acid 1 / vinyl chloride 84 / vinyl acetate 15 wt%), weight average molecular weight 19,600, glass transition point (Tg) = 79 ° C.
-Vinyl acetate / ethylene copolymer (vinyl acetate content is 41% by mass), melting point = 40 ° C (DSC)
-Byron 220 / GK810: Amorphous polyester resin manufactured by Toyobo Co., Ltd., of Byron 220 (number average molecular weight 3,000, Tg = 53 ° C) and Byron GX810 (number average molecular weight 6,000, Tg = 46 ° C). 50/50 wt% mixture-CMPS VN503: Mitsui-DuPont Polychemical Co., Ltd. Ethylene polymer Vicat softening temperature = 53 ° C

[Painting on lid material]
A bar coater was used on a general-purpose hard aluminum foil (product name, film thickness 25 μ), and each sealing adhesive was applied at a coating amount of 3 g / m ² , and the drying conditions were 180 ° C. and 10 seconds.

[Heat seal processing]
The lid material painted and dried above was applied to a PVC sheet of hard PVC manufactured by Sumitomo Bakelite Co., Ltd. (product name VSS-1202, film thickness 250 μm) using a heat seal tester manufactured by Tester Sangyo Co., Ltd., at 140 ° C and 180 ° C, respectively. Also heat-sealed at 0.3 MPa for 1 second) to prepare a test piece.

[Evaluation Criteria 1: Adhesiveness by peeling test]
Using the small tabletop tester EZ test manufactured by Shimadzu Corporation, the produced test piece was peeled at a peeling speed of 100 mm / min, peeled at 180 degrees in the peeling direction, and the adhesive strength was measured at a peeling width of 15 mm.
In addition, the adhesive strength of the prepared test piece immersed in water at 40 ° C. for 6 months was measured under the same conditions, and the change with time under the heat-resistant heat resistance condition was compared.
5 to 15 N / 1.5 cm is preferable, and 5 to 12 N / 1.5 cm is ideal. If it is 5N / 1.5cm or less, it may peel off during storage and the airtightness may not be maintained. If it is 15 N or more, it becomes difficult for children, elderly people, etc. to peel it off by hand, and the work of a pharmacist or the like who opens a large amount of medicine in a day at a hospital or the like becomes a heavy burden.

[Evaluation Criteria 2: State of peeling interface]
In addition to the measurement of Evaluation Criteria 1, the state of the peeling interface was visually evaluated in three stages according to the following criteria.
"Uniform coagulation in the heat seal layer" without delamination between "bottom material and heat seal layer" or "between aluminum lid material and heat seal" or "non-uniform coagulation peeling in the heat seal layer" Those that "peel off" were regarded as acceptable products. The white uniform interface surface can be visually confirmed in the "uniformly coagulated and peeled material".
For the evaluation, those immersed in water at 40 ° C. for 6 months were also visually evaluated according to the same criteria.

◯: The interface surface is uniformly white, and uniform cohesive peeling in the heat seal layer can be confirmed.
Δ: Delamination between “bottom material and heat seal layer” and “between aluminum lid material and heat seal” and “non-uniform cohesive peeling in the heat seal layer” can be confirmed on a part of the interface surface.
X: Delamination between "bottom material and heat seal interlayer" or "aluminum lid material and heat seal interlayer",
"Non-uniform cohesive peeling in the heat seal layer" can be confirmed.

Table 4 shows the adhesive strength measurement values for the examples of Tables 1 and 2 and the visual evaluation results of the peeled state.

Table 5 shows the adhesive strength measurement values for the comparative examples in Table 3 and the visual evaluation results of the peeled state.
The part (-) in the table does not adhere and indicates that measurement is impossible.

The sealing adhesive composition of the present invention shown in the examples can maintain an ideal adhesiveness of 5 to 12 N / 1.5 cm, and the adhesive force may decrease due to hydrolysis with moisture even under moist heat resistant conditions. Excellent storage stability over time. In addition, the interface surface is uniformly white, and almost uniform cohesive peeling in the heat seal layer can be reproduced. Most of the sealing adhesive composition shown in the comparative example is delaminated, and when the lid material is peeled off, it is not possible to obtain proof (evidence) that the adhesive composition was properly adhered before opening. In addition, it was confirmed that the adhesiveness was insufficient and the airtightness could not be maintained during storage, and that the adhesive strength decreased due to hydrolysis by moisture under moist heat resistant conditions.
To describe the details, in Comparative Example 1 containing only the (meth) acrylic copolymer (A), the adhesiveness between the aluminum lid material and the heat-sealed layer was lowered, and delamination was confirmed between them.
In Comparative Examples 2 and 3 which do not contain the vinyl acetate copolymer (C), delamination of "bottom material and heat seal interlayer" and "aluminum lid material and heat seal interlayer" and non-uniform aggregation in the heat seal layer Peeling occurred, and the degree became more remarkable under moisture-resistant heat resistance.
In Comparative Example 4 containing only the acid group-containing vinyl chloride vinyl acetate-based copolymer (B), delamination between the bottom material and the heat-sealed layer was performed at an adhesive temperature of 140 ° C., and inside the heat-sealed layer at an adhesive temperature of 180 ° C. Non-uniform cohesive peeling was confirmed in Comparative Example 5, and a tendency similar to that of Comparative Example 4 was observed in Comparative Example 5 in which the (meth) acrylic copolymer (A) was not used.

The adhesive composition for sealing of the present invention is not limited to the adhesive for PTP packaging materials, and can be widely applied to industrial products such as food packaging, sanitary products, cosmetics, and various electronic parts compatible with easy peel.

1 Aluminum foil lid material 2 Heat seal coat layer 3 Polyvinyl chloride (PVC) bottom material 4 Sealing adhesive of the present invention that reproduces uniform cohesive peeling in the heat seal layer

Claims (3)

A sealing adhesive composition containing a (meth) acrylic copolymer (A), an acid group-containing vinyl chloride vinyl acetate-based copolymer (B), and a vinyl acetate copolymer (C).
Solids in 100 wt% of the sealing adhesive composition, the (meth) acrylic copolymer (A) and 35 to 90 wt%, acid group-containing vinyl chloride-vinyl acetate copolymer (B) 5 to 25 A sealing adhesive composition containing 5 to 40% by mass of the vinyl acetate copolymer (C).
However, the vinyl acetate copolymer (C) is a vinyl acetate / ethylene copolymer, and the content of the amount of vinyl acetate, which is a copolymerization component, is 5 to 50 mass in the vinyl acetate copolymer (C). %.
The sealing adhesive composition according to claim 1, wherein the copolymerization component of the acid group-containing vinyl chloride vinyl acetate-based copolymer (B) contains an acid component of maleic acid or fumaric acid.
A press-through pack package in which the sealing adhesive composition according to claim 1 or 2 is applied to at least one side of an aluminum foil and bonded to a film.

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