JP2000177075A - Self-adhesive packaging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent adhesive properties, heat resistance, microwave oven suitability, cuttability and flexibility by forming a surface layer of a propylene block copolymer and an intermediate layer of an unoriented multilayer film made of a thermoplastic polyester resin. SOLUTION: The self-adhesive packaging film comprises a laminate of at least three layers of both surface layers and an intermediate layer. Both surface layers are each formed of a propylene resin composition containing 100 pts.wt. of a propylene block copolymer and 8 pts.wt. or below of a fatty acid ester of an aliphatic polyhydric alcohol. As the propylene block copolymer used for both the surfaces, a block copolymer obtained by generating 40 to 85 pts.wt. of total polymerization amount of the propylene-ethylene copolymer of 1.5 to 6.0 pts.wt. of a content of a repeating unit (ethylene unit) derived from the ethylene in the first step and generating 15 to 60 pts.wt. of total polymerization amount of the propylene-ethylene copolymer of 7 to 17 pts.wt. of a content of the ethylene unit in the second step is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-adhesive packaging film made of a non-chlorine resin, and more particularly, it has excellent self-adhesion without using a chlorine resin, and has heat resistance and microwave oven suitability. Self-adhesive packaging film having cutting ability, flexibility, transparency and food safety.

[0002]

2. Description of the Related Art Self-adhesive packaging films of this kind are:
It is often used in households, restaurants, hotels, etc. to seal food, preventing the dissipation of moisture when stored in a refrigerator, preventing the dissipation of moisture when heating in a microwave, and the flavor during storage. It also has the effect of preventing odors from being emitted, preventing other odors from adhering, and preventing dust from adhering. In particular, with the spread of microwave ovens in recent years, the demand for this use has increased significantly. That is, the self-adhesive packaging film is used for hermetically packaging a ceramic or glass container or the like containing food in order to prevent moisture from evaporating in a microwave oven and impairing the flavor.

[0003] Conventional self-adhesive packaging films are known which mainly use polyvinylidene chloride, polyethylene, polyvinyl chloride or polypropylene.
Films containing polyvinylidene chloride or polyvinyl chloride as a main raw material have strong adhesion to a container or strong adhesion between the films, have appropriate flexibility, and are preferably used. Contains a large amount of chlorine, so it generates hydrogen chloride gas during incineration, or
A large amount of plasticizer is a problem, and its environmental suitability is not sufficient. Furthermore, polyvinylidene chloride films are more expensive than the other two.

On the other hand, a film containing polyethylene or polypropylene as a main component does not generate hydrogen chloride gas during incineration, but the adhesiveness of the resin itself is lower than that of a film mainly containing polyvinylidene chloride or polyvinyl chloride. Weak and insufficiently sticky.

[0005] In addition to the strong adhesiveness, the packaging film used in such applications has a small heat shrinkage in a microwave oven and has the property of not perforating, causing heat melting and whitening (hereinafter referred to as "microwave oven"). Aptitude ”). However, a film made of polyvinylidene chloride has a disadvantage that shrinkage upon heating is large. Films made of polyethylene have the disadvantage that they adhere to oils such as meat and tempura and the film is perforated when heated, and films made of polyvinyl chloride cause whitening when they come in contact with boiling water. There's a problem. Therefore, at present, none of these conventional self-adhesive packaging films is sufficient as microwave oven suitability.

On the other hand, such a self-adhesive packaging film has a width of 20 to 45 cm wound around a core material such as a paper tube.
m, a film with a thickness of 8 to 15 μm is used by storing it in a case such as a paper box. The film is cut into appropriate lengths by applying it to a cutting blade called a “saw blade” attached to this case. Is done. The above-mentioned "saw blade" generally has a diameter of 0.1 mm.
A simple blade is used, which is obtained by simply punching a steel plate or cardboard having a thickness of about 2 mm into a saw shape, and a case for supporting the "saw blade" is also 350 to 700.
A cardboard box of about g / m ² is used, and the rigidity is extremely low.

[0007] The self-adhesive packaging film is required to be easily cut by such a simple cutting mechanism, but a film made of polyvinylidene chloride is part of the film at the time of cutting. When a breach occurs, the breach spreads and cuts diagonally without being cut along the "saw blade". In addition, a film mainly composed of polyethylene or polyvinyl chloride has a large elongation at the time of cutting and has poor sharpness.

For this reason, development of a self-adhesive packaging film using a chlorine-free resin as a raw material has been attempted. For example, Japanese Patent Application Laid-Open No. 6-262738 discloses one or both surfaces of a thermoplastic polyester resin film layer. 3 of ethylene, propylene and an α-olefin having 4 to 8 carbon atoms
In the original copolymer, an acyl group having 2 to 6 carbon atoms and 8 to 8 carbon atoms
A glyceride having an acyl group of 22 and a carbon number of 1
A film in which a film layer comprising an ester of 2 to 22 higher fatty acids and an aliphatic polyhydric alcohol and containing an antifogging agent selected from fatty acid esters having at least one alcoholic hydroxyl group has been proposed. I have. Also,
JP-A-5-116262 discloses a packaging film in which a propylene-based resin layer is disposed on both sides of a polyester resin layer, and the propylene-based resin layer contains polybutene, polyisobutylene, or polyglycerin fatty acid ester. Proposed. However, excellent adhesion, heat resistance, microwave oven suitability without using chlorine-based resin,
"Saw blade" A self-adhesive packaging film that satisfies all of cutability, flexibility, transparency and food safety has not yet been obtained.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide excellent adhesiveness, heat resistance, microwave oven suitability, "saw blade" cutability, flexibility, transparency and food safety without using a chlorine-based resin. An object of the present invention is to provide a self-adhesive packaging film that satisfies both properties.

[0010]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies on a self-adhesive packaging film made of a non-chlorine-based resin, and have found that at least three layers of both surface layers and an intermediate layer are laminated. It has been found that an unstretched multilayer film comprising a propylene-based block copolymer as a surface layer and a thermoplastic polyester resin as an intermediate layer achieves the object of the present invention, and has completed the present invention.

That is, the present invention relates to a film comprising a laminate of at least three layers composed of both surface layers (A) and an intermediate layer (B). A propylene-based resin composition containing 100 parts by weight of a block copolymer (a1) and 8 parts by weight or less of a fatty acid ester of an aliphatic polyhydric alcohol (c1),
The self-adhesive packaging film, wherein the intermediate layer (B) is made of a thermoplastic polyester resin. Propylene-based block copolymer (a1) A propylene-ethylene copolymer portion (component X) having a content of a repeating unit derived from ethylene in the first step of 1.5 to 6.0 parts by weight is subjected to a total polymerization amount (component X). (The sum of the X component and the following Y component) in an amount of 40 to 85 parts by weight, and then the content of the repeating unit derived from ethylene in the second step is 7 to 17 parts.
Parts by weight of propylene-ethylene copolymer part (Y component)
Is a block copolymer obtained by producing 15 to 60 parts by weight of the total polymerization amount (the sum of the X component and the Y component), and
The intrinsic viscosity ([η] Y) of the component is 2 to 5 dl / g, and the ratio ([η] Y / [) of the intrinsic viscosity ([η] Y) of the Y component to the intrinsic viscosity ([η] X) of the X component. η] X) Propylene block copolymer having 0.5 to 1.8 Hereinafter, the present invention will be described in detail.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The self-adhesive packaging film of the present invention comprises at least three of the surface layer (A) and the intermediate layer (B).
It is composed of a laminate of layers.

Both surface layers (A) of the present invention comprise 100 parts by weight of a propylene block copolymer (a1) and 8 parts by weight or less, preferably 1 to 6 parts by weight of a fatty acid ester of an aliphatic polyhydric alcohol (c1). And a propylene-based resin composition containing If the content of the fatty acid ester (c1) of the aliphatic polyhydric alcohol exceeds 8 parts by weight, bleeding to the film surface becomes severe, causing whitening and stickiness of the film, and unfavorable touch.

Further, both surface layers (A) are composed of 100 parts by weight of a propylene-based block copolymer (a1), 8 parts by weight or less, preferably 1 to 6 parts by weight of a fatty acid ester of an aliphatic polyhydric alcohol (c1). A layer composed of a propylene-based resin composition containing 1 part by weight or less, preferably 0.05 to 1 part by weight of ether (c2) of polyoxyethylene and aliphatic alcohol is preferable. Further, both surface layers (A)
Is a propylene-based block copolymer (a1) 100 parts by weight, an aliphatic polyhydric alcohol fatty acid ester (c1) 8
1 part by weight or less, preferably 1 to 6 parts by weight, 1 part by weight or less, preferably 0.05 to 1 part by weight of polyoxyethylene and aliphatic alcohol ether (c2), and liquid aliphatic hydrocarbon (c3), 20 parts by weight of at least one tackifier selected from the group consisting of a crystalline olefin resin (c4), a hydrogenated petroleum hydrocarbon resin (c5), and a vinyl aromatic compound-conjugated diene block copolymer (c6). Less than,
A layer composed of a propylene-based resin composition containing preferably 2 to 15 parts by weight is more preferable.

The propylene-based block copolymer (a1) used for both surface layers (A) of the present invention comprises a repeating unit derived from ethylene in the first step (hereinafter referred to as “ethylene unit”).
Propylene-ethylene copolymer portion (component X) having a content of 1.5 to 6.0 parts by weight is produced in an amount of 40 to 85 parts by weight of the total polymerization amount (total of component X and component Y below). Then, in the second step, a propylene-ethylene copolymer portion (Y component) having an ethylene unit content of 7 to 17 parts by weight is produced in an amount of 15 to 60 parts by weight of the total polymerization amount (the sum of the X component and the Y component). The intrinsic viscosity ([η] Y) of the Y component is 2 to 5 dl / g, the intrinsic viscosity of the Y component ([η] Y) and the intrinsic viscosity of the X component ([η ] X) and a ratio ([η] Y / [η] X) of 0.5 to 1.8. The propylene-based block copolymer is, for example, a propylene-based block copolymer described in JP-A-9-32022. By using the propylene-based block copolymer described in JP-A-9-32022, a film having excellent adhesiveness, flexibility, transparency, and heat resistance required for a self-adhesive packaging film can be obtained. . The propylene-based block copolymer used in the present invention refers to propylene-
An ethylene copolymer portion, a copolymer obtained by sequentially polymerizing a propylene-ethylene copolymer portion having a different ethylene content in the second step, wherein the copolymer terminal and another copolymer It is not a typical block copolymer in which the ends are linked by a bond, but a kind of a blend-based copolymer.
Further, the propylene-based block copolymer is also referred to as an impact-resistant propylene copolymer.

When the content of the ethylene unit in the propylene-ethylene copolymer portion (component X) to be polymerized in the first step is less than 1.5 parts by weight, the flexibility is lowered and exceeds 6.0 parts by weight. In such a case, heat resistance is undesirably reduced. In particular, it is preferable that the content of the ethylene unit is 2.5 to 4.5 parts by weight from the viewpoint of the balance between flexibility and heat resistance.

In the propylene-ethylene copolymer portion (Y component) polymerized in the second step, the ethylene unit content is 7
When the amount is less than 10 parts by weight, the cold resistance is reduced, and when the amount is more than 17 parts by weight, the transparency is undesirably reduced. In particular,
It is preferable that the content of the ethylene unit is 8 to 13 parts by weight from the viewpoint of the balance between the cold resistance and the transparency.

The content of the ethylene unit is measured by the ¹³ C-NMR method according to the method described on page 616 of a polymer handbook (1995, published by Kinokuniya Bookstore). The content (EX) of the ethylene unit of the X component is analyzed by sampling the copolymer after the completion of the polymerization in the first step. The content of the ethylene unit of the Y component (EY) is determined by sampling the block copolymer after the completion of the polymerization in the second step,
The ethylene content (EXY) of the block copolymer was analyzed, and the ratio of the X component (PX) and the ratio of the Y component (P
Y) from the following equation. EX × PX / 100 + EY × PY / 100 = EXY EY = (EXY−EX × PX / 100) × 100 / PY

The ratio of the propylene-ethylene copolymer part (component X) polymerized in the first step to the propylene-ethylene copolymer part (component Y) polymerized in the second step is X
The component is 40 to 85 parts by weight, preferably 55 to 83 parts by weight, and the Y component is 60 to 15 parts by weight, preferably 45 to 17 parts by weight.
Parts by weight.

When the amount of the Y component is less than 15 parts by weight, the cold resistance is insufficient, and when the amount exceeds 60 parts by weight, the heat resistance is undesirably deteriorated. In particular, the proportion of the Y component is more preferably 17 to 27 parts by weight from the viewpoint of moldability.

Producing a propylene-ethylene copolymer portion in which the Y component is 17 to 27 parts by weight in the polymerization step to obtain a propylene-ethylene copolymer portion in which the Y component particularly ranges from 17 to 27 parts by weight. It is also possible to prepare a propylene-ethylene copolymer portion having a Y component ratio of 27 to 60 parts by weight by polymerization, and to adjust the ratio of the Y component by adding only the X component at the time of melt-kneading. It is possible.

The intrinsic viscosity ([η] Y) of the Y component of the propylene block copolymer used in the present invention is 2 to 5 dl / g,
The intrinsic viscosity of the Y component ([η] Y) and the intrinsic viscosity of the X component ([η]
X) (([η] Y / [η] X)) is required to be 0.5 to 1.8 from the viewpoint of transparency. [Η] Y is 2 dl
If it is less than 5 g / g, the low molecular weight component increases, and if it is more than 5 dl / g, the fluidity of the propylene-ethylene block copolymer decreases, and the processability decreases. In particular, the intrinsic viscosity ([η] Y) of the Y component of the propylene-ethylene copolymer is 2.5 to 4.5 dl /.
g is more preferable in terms of balance between suppression of low molecular weight components and processability.

If the [η] Y / [η] X ratio is less than 0.5 or exceeds 1.8, the compatibility between the X component and the Y component is reduced, and the transparency is undesirably reduced. In particular, [η]
It is more preferable that the Y / [η] X ratio is 0.8 to 1.5 from the viewpoint of transparency.

The intrinsic viscosity is measured at 135 ° C. in tetralin using an Ubbelohde viscometer. The intrinsic viscosity ([η] X) of the X component is analyzed by sampling the copolymer after completion of the polymerization in the first step. Intrinsic viscosity of Y component ([η] Y)
Is to sample the block copolymer after completion of the polymerization in the second step, analyze the intrinsic viscosity ([η] XY) of the block copolymer, and further determine the ratio of the X component (PX) and the ratio of the Y component (PY). From the following equation. [η] X × PX / 100 + [η] Y × PY / 100 = [η] X
Y [η] Y = ([η] XY− [η] X × PX / 100) × 100
/ PY

The weight average molecular weight of the xylene-soluble component at 20 ° C. in the propylene block copolymer used in the present invention is 260.
The content of the component of not more than 00 is not more than 6 parts by weight.
-It is preferable in terms of suppressing the amount of extraction with hexane or the like.
In particular, from the viewpoint of serving as a food packaging material, the weight-average molecular weight of 26,000 ° C. xylene-soluble component in all polymers is 26000.
More preferably, the content of the following components is 3.5 parts by weight or less.

The propylene-based block copolymer used in the present invention has a content of ethylene unit of component Y (EY) and a content of ethylene unit of component X (E) from the viewpoint of transparency and cold resistance.
(EY-EX) is preferably in the range of 3 to 15 parts by weight, and from the viewpoint of the balance between transparency and cold resistance, (EY-EX) is more preferably 5 to 10 parts by weight.

The propylene-based block copolymer used in the present invention is a batch polymerization method for producing an X component in the same polymerization tank in the presence of a Ziegler-Natta type catalyst, and subsequently producing a Y component. Or a continuous polymerization method in which the X component and the Y component are continuously polymerized using a polymerization tank having at least two tanks.

Specifically, for example, in the coexistence of (x) an organosilicon compound having a Si--O bond, a compound represented by the general formula Ti (OR
¹ ) a titanium compound represented by _n X _4-n (wherein R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom, n is a number satisfying 0 <n ≦ 4) and / or Or a trivalent titanium compound-containing solid catalyst component obtained by treating a solid product obtained by reducing an ether compound with an organomagnesium compound with a mixture of an ester compound and an ether compound with titanium tetrachloride, (y) the organic aluminum compound (z) Si-oR ² bonds (R ² is a hydrocarbon group having 1 to 20 carbon atoms.) the catalyst system consisting of a silicon compound having, or (x) the general formula Ti (oR ¹⁾ _n X _4-n (wherein, R ¹ is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen atom, and n is 0 <
represents a number of n ≦ 4. The represented by titanium compounds), the general formula AlR ² _m Y _3-m (wherein, R ² has a carbon number 1-2
0 represents a hydrocarbon group, Y represents a halogen atom, and m represents a number of 1 ≦ m ≦ 3. ), A solid product containing a hydrocarbyloxy group insoluble in a hydrocarbon solvent obtained by reduction with an organoaluminum compound represented by the formula (1), is subjected to a prepolymerization treatment with ethylene, and then an ether compound and titanium tetrachloride in the hydrocarbon solvent. A hydrocarbyloxy group-containing solid catalyst component obtained by treating in a slurry state at a temperature of from 80 to 100 ° C. in the presence of (a) a catalyst system comprising (y) an organoaluminum compound; and at least titanium, magnesium and halogen as essential components. In the presence of a Ziegler-Natta type catalyst, the molar ratio of Al atoms in component (y) / Ti atoms in component (x) is 1 to 2000, preferably 5 to 1500,
The molar ratio of Al atoms in component (z) / component (y) is set to 0.0
The polymerization temperature is 20 to 150 ° C, preferably 50 to 95 ° C.
° C., the polymerization pressure is atmospheric pressure ~40kg / cm ² G, preferably under conditions of 2~40kg / cm ² G, and supplies the hydrogen to propylene and ethylene and the molecular weight regulator in the first step propylene - ethylene copolymer After producing the polymer portion (X component), it can be produced by subsequently supplying propylene, ethylene and hydrogen in the second step to produce a propylene-ethylene copolymer portion (Y component).

The propylene block copolymer used in the present invention can change the fluidity represented by, for example, a melt flow rate by a known method in the presence or absence of an organic peroxide. . The propylene-based block copolymer may further contain an antioxidant, an ultraviolet absorber, an antistatic agent, a nucleating agent, and the like, if necessary. Further, both surface layers (A) may contain up to 20 parts by weight of another propylene-based resin within a range that does not impair the physical properties of the propylene-based block copolymer. The propylene-based resin is not particularly limited as long as it is other than the propylene-based block copolymer. Examples of the propylene-based resin include a propylene homopolymer and a propylene-α-olefin copolymer. Examples of the α-olefin include α, such as ethylene, butene-1, and hexene-1.
-One or more olefins can be used. Further, the copolymer may be any of a random copolymer and a block copolymer.

The fatty acid ester of aliphatic polyhydric alcohol (c1) and the ether of polyoxyethylene and aliphatic alcohol (c2) used for both surface layers (A) of the present invention are:
It has the effect of improving the texture of the film, suppressing excessive sticking, and giving the film an appropriate feeding property.

Examples of the aliphatic polyhydric alcohol used as a raw material of the fatty acid ester (c1) include glycerin, polyglycerin, sorbitan, pentaerythritol, propylene glycol, polyethylene glycol and the like. Examples of the fatty acid include lower fatty acids such as acetic acid; medium-chain fatty acids having 8 to 12 carbon atoms; and higher fatty acids having 12 to 22 carbon atoms such as oleic acid, linoleic acid, and lauric acid. Among the fatty acid esters used in the present invention, the fatty acid ester of glycerin is known as (mono, di or tri) glyceride and is represented by the following formula (I).

[0032] (In the formula, R ¹ , R ² and R ³ are H or an acyl group having 2 to 22 carbon atoms, and at least one is an acyl group having 2 to 22 carbon atoms.) The fatty acid ester used in the present invention Examples of (c1) include monoglycerides such as glycerin oleate; glycerin diacet monooleate, glycerin diacet monolaurate, glycerin diacet monopalmitate, glycerin monoacetomonopalmitate, glycerin monoacetomonooleate, glycerin monoacetomonocaprate and the like. Acetylated monoglycerides; acetylated diglycerides such as glycerin monoacetodiolate and glycerin monoacetodilaurate; medium-chain fatty acid triglycerides having an acyl group having 8 to 12 carbon atoms; polyglyceres such as diglycerindiolate and diglycerin laurate. Emissions fatty acid esters; propylene glycol fatty acid esters such as propylene glycol oleate; pentaerythritol fatty acid esters such as pentaerythritol oleate, polyethylene glycol oleate polyethylene glycol fatty acid esters and the like. Among these, acetylated glycerides into which at least one higher fatty acid ester has been introduced, medium-chain fatty acid triglycerides having an acyl group having 8 to 12 carbon atoms, and at least 1
Polyglycerin fatty acid esters having two alcoholic hydroxyl groups are preferred. These aliphatic esters may be used alone or in combination of two or more.

The polyoxyethylene used as the raw material of the ether (c2) includes those having an average number of repeating units of ethylene glycol (hereinafter referred to as "ethylene glycol units") of, for example, 1 to 20. Aliphatic alcohols have 12 to 20 carbon atoms and include, for example, lauryl alcohol, cetyl alcohol, stearyl alcohol,
Oleyl alcohol and the like. Examples of the ether (c2) used in the present invention include polyoxyethylene lauryl alcohol ether (average number of ethylene glycol units: 4, 10) and polyoxyethylene cetyl alcohol ether (average number of ethylene glycol units:
2, 10, 20), polyoxyethylene stearyl alcohol ether (average number of ethylene glycol units:
2, 10, 20), polyoxyethylene oleyl alcohol ether (average number of ethylene glycol units: 2,
10, 20). These ethers may be used alone or in combination of two or more.

The tackifiers used for both surface layers (A) of the present invention include liquid aliphatic hydrocarbons (c3), amorphous olefin resins (c4), and hydrogenated petroleum hydrocarbon resins (c5).
And at least one type of tackifier selected from vinyl aromatic compound-conjugated diene block copolymer (c6), and both can impart more excellent tackiness to the film.

The liquid aliphatic hydrocarbon (c3) is a saturated hydrocarbon such as paraffinic, isoparaffinic, and naphthenic, and an unsaturated hydrocarbon such as olefin, which are liquid at room temperature. Examples of the liquid aliphatic hydrocarbon (c3) include saturated hydrocarbons such as liquid paraffin, mineral oil and white mineral oil, and unsaturated hydrocarbon polymers such as polybutene and polyisobutylene. These may be used alone or as a mixture of two or more. The physical properties of these liquid aliphatic hydrocarbons are not particularly limited, but are usually 40
Those having a kinematic viscosity at 5 ° C. in the range of 5 to 30,000 cSt, preferably 50 to 30,000 cSt are used. Specific examples include Nippon Petrochemical Co., Ltd. Nisseki polybutene.

The amorphous olefin resin (c4) is an olefin resin having a boiling n-heptane insoluble content, that is, a Soxhlet extraction insoluble content with boiling n-heptane of 70 parts by weight or less, preferably 60 parts by weight or less. is there. Boiling n
-When heptane is larger than 70 parts by weight, the ratio of the amorphous portion becomes small, and sufficient tackiness cannot be imparted. Examples of the amorphous olefin resin (c4) include amorphous polypropylene, amorphous propylene-ethylene copolymer, amorphous propylene-butene-1 copolymer, and amorphous propylene-butene-1-ethylene. Terpolymer,
Polymers having a propylene component as a main component such as amorphous propylene-hexene-1-ethylene terpolymer; amorphous polybutene-1, amorphous butene-1-ethylene copolymer,
Butene-1 such as amorphous butene-1-propylene copolymer, amorphous butene-1-propylene-ethylene terpolymer, amorphous butene-1-hexene-1-ethylene terpolymer and the like. Examples of the polymer include a polymer whose component is a main component. These can be used alone or in combination of two or more. Specifically, Ube Tack UT2780 or C manufactured by Ube Lexen Co., Ltd.
AP350, CAP355S, or the like can be used.

Hydrogenated petroleum hydrocarbon resins (c5) include hydrogenated aromatic hydrocarbon resins, hydrogenated aliphatic hydrocarbon resins, hydrogenated alicyclic hydrocarbon resins, and hydrogenated aliphatic / alicyclic resins. Aliphatic hydrocarbon resins, hydrogenated aliphatic / aromatic hydrocarbon resins, etc., among which the weight average molecular weight is 500 to 50
About 00 is preferable. Examples of the hydrogenated petroleum hydrocarbon resin (c5) include a hydrogenated terpene resin, a hydrogenated polycyclopentadiene resin, a hydrogenated α-methylstyrene / vinyltoluene resin, and the like. In particular,
Arakawa Chemical Industries, Ltd. Alcon P-125, P-140
Etc. can be used.

The vinyl aromatic compound-conjugated diene block copolymer (c6) is a block copolymer of a vinyl aromatic compound and a conjugated diene. Styrene is typical as the vinyl aromatic compound in the above copolymer,
Other than this, for example, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, vinylxylene,
Examples include ethylvinylxylene and vinylnaphthalene, and examples of the conjugated diene include butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene. As the block copolymer, one having a terminal block made of styrene is preferable. The average molecular weight of the block copolymer is preferably from about 10,000 to about 1,000,000, more preferably from about 20,000 to about 20,000.
300,000. The block copolymer is preferably one in which 90% or more, particularly 99% or more, of the aliphatic double bond is hydrogenated. Specifically, Dynalon 1320P manufactured by Nippon Synthetic Rubber Co., Ltd. can be used.

Next, the intermediate layer (B) in the self-adhesive packaging film of the present invention is used in the MD direction in order to exhibit the “saw blade” cut property among the properties required for the self-adhesive packaging film. The tensile elongation at break must be small,
Further, in order not to impair the transparency of the film, a resin having high transparency, heat resistance and fragrance retention is preferable.

The thermoplastic polyester resin used in the intermediate layer (B) of the present invention is not particularly limited as long as it is produced by polycondensation with a known dibasic acid or dibasic acid ester and a polyhydric alcohol. Not something. Examples of dibasic acids include terephthalic acid, isophthalic acid,
And aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid. Examples of the dibasic acid ester include dimethyl terephthalate. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, pentamethylene glycol, 2,2-
Examples thereof include aliphatic and aromatic diols such as dimethyltrimethylene glycol, hexamethylene glycol, P-xylylene glycol, and neopentyl glycol, and these can be used alone or as a mixture of two or more.

Examples of the thermoplastic polyester resin used in the present invention include polyethylene terephthalate, ethylene glycol / 1,4-cyclohexanedimethanol / terephthalic acid polycondensate, and 1,4-cyclohexanedimethanol terephthalic acid / isophthalic acid polycondensate. At least one kind of thermoplastic polyester resin selected from among them is preferred in view of cut properties, transparency and heat resistance. Polyethylene terephthalate is obtained by polycondensing terephthalic acid and ethylene glycol.Ethylene glycol / 1,4-cyclohexane dimethanol / terephthalic acid polycondensate is obtained by polycondensing terephthalic acid with ethylene glycol and 1,4-cyclohexane dimethanol. The 1,4-cyclohexanedimethanol / terephthalic acid / isophthalic acid polycondensate is obtained by polycondensing terephthalic acid, isophthalic acid, and 1,4-cyclohexanedimethanol. Specifically, these are Eastman Chemical's EASTA
PAK PET7352, EASTAPAK PET9
921, EASTAR PETG6763, EASTE
It is available under the grade name of RA150.

The self-adhesive packaging film of the present invention can be prepared by a known method such as co-extrusion of a surface layer and an intermediate layer by T-die casting or inflation molding using a plurality of extruders and lamination molding. Can be manufactured. The co-extrusion molding method by T-die cast molding is preferable in that a film having excellent smoothness can be obtained.
In particular, when quenching is performed by contacting with a roll having a surface temperature of 20 ° C. or less during molding, crystallinity can be suppressed low, and transparency and adhesiveness can be improved.

The thickness of the self-adhesive packaging film of the present invention is usually from 5 to 40 μm, and preferably from 8 to 20 μm from the balance between the strength of the film and the suitability for packaging. In addition, the ratio of the thickness of the intermediate layer to the thickness of the entire film is not particularly limited, but is preferably in the range of 10 to 70% from the balance between cutability and flexibility.

[0044]

Next, the present invention will be described based on examples.
The present invention is not limited to these examples.
The method of measuring physical properties in the following examples and comparative examples will be described. (1) Adhesiveness 90 ° peeling force (adhesion between film and container) 10 cm in width of a film sample piece of 10 cm in width and 15 cm in length
Adhesion to glass plate of × 10cm, 23 ℃, 50% RH
After a load of 500 g was applied for 30 minutes in the atmosphere described above, one end in the longitudinal direction of the film was fixed to a jig, and the film was pulled up at a speed of 200 mm / min in a direction perpendicular to the glass plate. At this time, the force required for lifting was measured, and the adhesive force was determined to be g / 10 cm.
The adhesive strength is preferably 3 to 20 g / 10 cm. When the 90 ° peeling force is less than 3 g / 10 cm, the adhesiveness at the time of packaging foods and containers deteriorates, which is not preferable.
If it exceeds 0 cm, it is not preferable because it is difficult to feed the film from the film. Vertical peeling force (adhesion between film and film) A 12 cm x 12 cm film sample piece was
Acrylic plate of 0cm is adhered so as not to wrinkle,
One side of the acrylic plate was covered with a film (sample A). A 10 cm wide, 15 cm long sample piece is 10 cm × 10 c
Then, the glass plate was adhered so as not to be wrinkled, and one surface of the glass plate was covered with a film (sample B). The film surfaces of the sample A and the sample B are brought into close contact with each other, and the temperature is 23 ° C. and 50% RH
After a load of 100 g was applied for 3 seconds in the atmosphere described above, the sample piece A was fixed to a jig, and the sample piece B was pulled up at a speed of 200 m / min in the vertical direction. At this time, the force required to separate the film surface was measured, and the result was defined as a vertical peel force g / 100 cm ² . The vertical peel force is preferably from 10 to 300 g / 100 cm ² . When the vertical peeling force is less than 10 g / 100 cm ² , the adhesiveness when packaging foods and containers is deteriorated, and the texture is poor, which is not preferable. When it exceeds 300 g / 100 cm ² , the stickiness is strong and It is not preferable because the feeding becomes difficult. Adhesive index An adhesive index that matches the adhesive strength obtained by the sensory evaluation was defined by the following formula. The larger the index is, the stronger the adhesiveness is, and the index is preferably between 8 and 20. Adhesiveness index = (90 ° peeling force) × (vertical peeling force) ^{0.2 When the} index is less than 8, the adhesion at the time of packaging foods and containers deteriorates and the texture is poor, which is not preferable, and exceeds 20. When,
It is not preferable because stickiness is strong and it becomes difficult to feed the film from the film.

(2) Heat-resistant temperature (heat resistance) According to Tokyo Metropolitan Ordinance No. 1072, “Quality indication of wrap film”, a 2.5 cm vertical and a rectangular film sample piece having a width of 3 cm and a length of 14 cm are sandwiched between jigs. 10g at the bottom of the specimen
Weight was lowered. In this state, the maximum ambient temperature at which the film did not break even after 1 hour was indicated in increments of 10 ° C. (3) Suitability for microwave oven A film sample of 10 cm in width and 15 cm in length was wrapped with a fried chicken (chicken, frozen product) and heated in a microwave oven with an output of 500 W for 90 seconds, and then the state of the film was evaluated. The evaluation criteria are as follows. ：: Neither perforation nor fusion was observed. ：: No holes were found. Some fusion of the films is observed, but this is practically acceptable. X: The film melts and a hole is formed. (4) “Saw blade” cutability Wrap the film around the core tube, and use the “saw blade” case (0.2
Saw blade punched steel plate “mm saw blade”
g / m ² coated cardboard case)
And cutability with a “saw blade” was evaluated. The evaluation criteria are as follows. ◎: Smooth just by pulling lightly on the “saw blade”
Cut straight. ：: It can be cut straight just by pulling it against the “saw blade”. X: Although the film can be cut, the film is easily stretched, and a hang is required. Or, the film stretched and could not be cut, and neither was practical.

(5) Young's modulus According to the method specified in ASTM D882. It shows that the smaller this value is, the more flexible it is.
000 kg / cm ² is preferable, and 3000-8000 k
g / cm ² is particularly preferred. MD / TD was measured. However, a test piece shape: a 20 mm × 120 mm strip type chuck Distance between chucks: 50 mm Tensile speed: 5 mm / min (6) Total haze (transparency) Measured according to JIS K7105. The smaller the value, the higher the transparency, preferably 2.0% or less, particularly preferably 1.0% or less.

(7) Ratio of X component and Y component (parts by weight) From the material balance at the time of polymerization of the X component and the Y component, the ratio of the X component (PX) and the ratio of the Y component (PY) were determined. (8) Intrinsic Viscosity ([η]) Measurement was performed in tetralin at 135 ° C. using an Ubbelohde viscometer. Intrinsic viscosities of X component and Y component ([η] X, [η] Y) Intrinsic viscosity [η] measured after completion of polymerization of X component in the first step.
X, intrinsic viscosity [η] X measured after completion of the polymerization in the second step
Y and X component ratio (PX), Y component ratio (P
From Y), the intrinsic viscosity [η] Y of the Y component was determined by the following equation. [η] Y = ([η] XY− [η] X × PX / 100) × 100
/ PY (9) Ethylene unit content Polymer Handbook (1995, published by Kinokuniya Bookstore)
¹³ C-N by the method described on page 616 of
The measurement was performed by the MR method. Content of ethylene unit of component X and component Y (EX, EY) The content of ethylene unit (EX) measured after completion of polymerization of component X in the first step and the content of ethylene unit measured after completion of polymerization of second step From the content (EXY), the ratio of the X component (PX), and the ratio of the Y component (PY), the content EY of the ethylene unit of the Y component was determined by the following equation. EY = (EXY−EX × PX / 100) × 100 / PY

(10) Melt flow rate (MFR) Measured according to JIS K7210 under the condition of -14. (11) Maximum melting peak temperature (Tm) Using a differential scanning calorimeter (DSC manufactured by PerkinElmer), 10 mg of a sample was previously melted at 220 ° C. for 5 minutes in a nitrogen atmosphere, and then at a temperature lowering rate of 5 ° C./min. Cool down to 40 ° C. Thereafter, the temperature was raised at 5 ° C./min, and the peak temperature of the maximum peak of the obtained melting endothermic curve was defined as the maximum melting peak temperature (Tm). The melting point of indium (In) measured at a heating rate of 5 ° C./min using this measuring instrument was 15
6.6 ° C.

Example 1 A propylene-based block copolymer (a1) polymerized in the same manner as the propylene-based block copolymer shown in Example 1 of JP-A-9-32022 (maximum melting peak temperature = 136 ° C.) , X component and Y component weight ratio = 70/3
0, content of ethylene unit of component X = 3.5 parts by weight, intrinsic viscosity ([η] X) = 3.0 dl / g, content of ethylene unit of component Y = 12.7 parts by weight, intrinsic viscosity ( [Η]
Y) = 3.2 dl / g, MFR = 2.6 g / 10 min) 9
8 parts by weight and a mixture of a fatty acid ester of an aliphatic polyhydric alcohol (c1) and an ether of an aliphatic alcohol of polyoxyethylene (c2) (STO manufactured by Marubishi Yuka Kogyo Co., Ltd.)
-405, 42.5 parts by weight of diglycerin monooleate (c1), 42.5 parts by weight of diglycerin monolaurate (c1), and polyoxyethylene lauryl based on 100 parts by weight of the mixture of (c1) and (c2) Alcohol ether (average number of ethylene glycol units: 10) (c2)
A propylene-based resin composition containing 2 parts by weight of a polyethylene terephthalate resin (EASTAPAK PE, Eastman Chemical Co.)
T7352) was disposed in the intermediate layer, and a three-layer three-layer film extruded from Chugai Tec Co., Ltd. was extruded to form a film using a T-die film forming machine. Specifically, the propylene-based resin composition was melt-kneaded at 270 ° C. with an extruder having a diameter of 40 mmφ and an L / D of 32, and led to both surface layers via a feed block.
The above polyethylene terephthalate resin is 50 mmφ, L
By melting and kneading at 270 ° C. with an extruder having a / D of 32, leading to an intermediate layer through a feed block, extruding these through a T-die (600 mm width) adjusted to 270 ° C., and taking up with a chill roll at 20 ° C. Cooled and solidified, total thickness 1
A 2 μm film was obtained. At this time, the layer thickness ratio was set to the surface layer /
Intermediate layer / surface layer = 2/1/2 and line speed is 4
5 m / min. Table 1 shows the physical properties of the obtained film.

Example 2 The intermediate layer in Example 1 was replaced with ethylene glycol 1,4
-Cyclohexane dimethanol / terephthalic acid polycondensate (EASTAPAKPET9 manufactured by Eastman Chemical Company)
A film was obtained in the same manner as in Example 1, except that the film was 921). Table 1 shows the physical properties of the film.

Example 3 The intermediate layer in Example 1 was replaced with ethylene glycol 1,4
-Cyclohexane dimethanol / terephthalic acid polycondensate (EASTAR PETG6, Eastman Chemical Company)
763), except that the extrusion temperature was 230 ° C. and the layer thickness ratio was surface layer / intermediate layer / surface layer = 1/1/1.
A film was obtained in the same manner as described above. Table 1 shows the physical properties of the film.

Example 4 The intermediate layer in Example 1 was 1,4-cyclohexanedimethanol / terephthalic acid / isophthalic acid polycondensate (EASTER A150, manufactured by Eastman Chemical Co.), the extrusion temperature was 280 ° C., and the layer thickness ratio was the surface layer. / Intermediate layer / surface layer =
A film was obtained in the same manner as in Example 1, except that the ratio was 1/1/1. Table 1 shows the physical properties of the film.

Example 5 Both surface layers in Example 3 were composed of 88.2 parts by weight of a propylene-based block copolymer (a1) and STO-405 (c1,
c2) 1.8 parts by weight of amorphous olefin resin (c4)
A film was obtained in the same manner as in Example 3, except that (CAP355S, manufactured by Ube Lexen Co., Ltd.) was used in an amount of 10 parts by weight.
Table 1 shows the physical properties of the film.

Example 6 Both surface layers in Example 3 were combined with 88.2 parts by weight of a propylene-based block copolymer (a1) and STO405 (c1,
c2) 1.8 parts by weight of propylene-ethylene random copolymer (Noblen S131 manufactured by Sumitomo Chemical Co., Ltd.)
A film was obtained in the same manner as in Example 3 except that 5 parts by weight and 5 parts by weight of a hydrogenated petroleum hydrocarbon resin (c5) (softening point 140 ° C., P-140 manufactured by Arakawa Chemical Industry Co., Ltd.) were used. Table 1 shows the physical properties of the film.

Comparative Example 1 A film was obtained in the same manner as in Example 1 except that both the surface layer and the intermediate layer in Example 1 were the same propylene resin composition as used in Example 1. Table 1 shows the physical properties of the film.

Comparative Example 2 The intermediate layer in Example 1 was replaced with a propylene-ethylene random copolymer (Noblen S13 manufactured by Sumitomo Chemical Co., Ltd.).
A film was obtained in the same manner as in Example 1 except that 1) was used. Table 1 shows the physical properties of the film.

Comparative Example 3 A film was obtained in the same manner as in Example 3 except that the surface layer in Example 3 was propylene homopolymer (Nobrene FS2011D manufactured by Sumitomo Chemical Co., Ltd.). Table 1 shows the physical properties of the film.

[0058]

[Table 1]

[0059]

As described above, according to the present invention, excellent adhesiveness, heat resistance, suitability for a microwave oven, "saw blade" cutability, flexibility, transparency and food safety are all satisfied. To provide a self-adhesive packaging film. Further, the self-adhesive packaging film of the present invention is a film which is particularly excellent in adhesiveness and “saw blade” cutability. Further, the self-adhesive packaging film of the present invention is made of a non-chlorine-based resin and has extremely high environmental suitability as compared with a film mainly composed of polyvinylidene chloride or polyvinyl chloride. Furthermore, the self-adhesive packaging film of the present invention is most suitable as a packaging film for household wrap film, commercial wrap film and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 9:00 F term (Reference) 4F100 AH01A AH01C AH01H AH02A AH02C AH02H AK02A AK02C AK02H AK03A AK03C AK03B AK07AAK42K AK54A AK54C AK54H AK64A AK64C AK73A AK73C AL02A AL02C AL05A AL05C AL06A AL06C AL06H BA03 BA06 BA10A BA10C BA15 EH20 GB15 GB23 JA06A JA06C JA12A JA12C JB16B JJ03 JK13 JL00 JL01 JL13 JL13H JN01 YY00A YY00C 4F207 AA09 AA11F AA24 AA47 AA49 AB01 AB19 AB20 AG01 AG03 AH81 KA01 KB26

Claims (4)

[Claims] 1. A film comprising a laminate of at least three layers composed of both surface layers (A) and an intermediate layer (B), wherein said both surface layers (A) have the following propylene-based block copolymer weight: The intermediate layer (B) comprises a propylene-based resin composition containing 100 parts by weight of the combined (a1) and 8 parts by weight or less of a fatty acid ester of an aliphatic polyhydric alcohol (c1), and the intermediate layer (B) comprises a thermoplastic polyester resin. Self-adhesive packaging film. Propylene-based block copolymer (a1) A propylene-ethylene copolymer portion (component X) having a content of a repeating unit derived from ethylene in the first step of 1.5 to 6.0 parts by weight is subjected to a total polymerization amount (component X). (The sum of the X component and the following Y component) in an amount of 40 to 85 parts by weight, and then the content of the repeating unit derived from ethylene in the second step is 7 to 17 parts.
Parts by weight of propylene-ethylene copolymer part (Y component)
Is a block copolymer obtained by producing 15 to 60 parts by weight of the total polymerization amount (the sum of the X component and the Y component), and
The intrinsic viscosity ([η] Y) of the component is 2 to 5 dl / g, and the ratio ([η] Y / [) of the intrinsic viscosity ([η] Y) of the Y component to the intrinsic viscosity ([η] X) of the X component. η] X) 0.5 to 1.8 propylene block copolymer 2. Both surface layers (A) are composed of 100 parts by weight of a propylene-based block copolymer (a1), 8 parts by weight or less of a fatty acid ester of an aliphatic polyhydric alcohol (c1) and polyoxyethylene and an aliphatic alcohol. The self-adhesive packaging film according to claim 1, comprising a propylene-based resin composition containing 1 part by weight or less of ether (c2). 3. Both surface layers (A) are composed of 100 parts by weight of a propylene-based block copolymer (a1), 8 parts by weight or less of a fatty acid ester of an aliphatic polyhydric alcohol (c1), and polyoxyethylene and an aliphatic alcohol. 1 part by weight or less of ether (c2), liquid aliphatic hydrocarbon (c3), amorphous olefin resin (c4), hydrogenated petroleum hydrocarbon resin (c
The self-adhesive composition according to claim 1, comprising a propylene-based resin composition containing 20 parts by weight or less of at least one tackifier selected from 5) and a vinyl aromatic compound-conjugated diene block copolymer (c6). Adhesive packaging film. 4. A thermoplastic polyester resin comprising polyethylene terephthalate, ethylene glycol / 1,4-cyclohexanedimethanol / terephthalic acid polycondensate,
The self-adhesive packaging film according to claim 1, which is at least one thermoplastic polyester resin selected from 4-cyclohexanedimethanol / terephthalic acid / isophthalic acid polycondensate.