JP3366775B2 - Easy tear-resistant moisture-proof packaging material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to an easily tearable moisture-proof packaging material.
In particular, it has excellent hand-cutting properties when opened,
Package with excellent preservation of contents due to excellent moisture resistance
For packaging materials. [0002] 2. Description of the Related Art Contents are scattered in packaging materials (films).
Require strength and physical properties to prevent rubbing and disappearance
In addition, what is called so-called
Protection performance is required. Moisture proof as one of this protection performance
There is. A biaxially oriented polyester film, for example,
Polyethylene terephthalate film is used as a packaging material.
Has sufficient strength, but does not have sufficient moisture-proof properties. Accordingly, (1) Japanese Utility Model Publication No. 62-13796
Let's look at aluminum-evaporated polyester film and
Lenfilm composite sheet used as moisture-proof packaging material
It has been proposed that In addition, (2) Tokubo 53-12
No. 953 discloses improvement of moisture proof by SixOy deposition.
As mentioned above, x = 1, 2,
y = 0, 1, 2, and 3 are defined. (3) In Japanese Patent Publication No. 56-40032, gas
Barrier packaging materials have been proposed.
Is dependent on the film's gas barrier properties.
You. Also, (4) JP-A-3-9930 discloses that
Moisture proof mainly composed of non-oriented polyester film
A flexible packaging material is disclosed. According to the results of the study by the present inventors, these packages
The material is not sufficiently hand-cut when opened,
In addition, gas burrs on the SixOy deposited film and the film itself
It is clear that moisture resistance is not sufficient with
Was. [0007] SUMMARY OF THE INVENTION It is an object of the present invention to open
It has excellent hand-cutting properties and excellent moisture resistance
To provide packaging materials with excellent preservation
You. [0008] SUMMARY OF THE INVENTION An object of the present invention is to provide
According to the first, (A) the inorganic substance is deposited under reduced pressure
A biaxially oriented polyethylene tereph having a thickness of 8 to 20 μm.
Tartrate film, (B) Inorganic material-adhered surface of the film A
Laminated with an adhesive layer on the side, and having a thickness of 8 to 20 μm.
Axially oriented polyethylene terephthalate film, and
(C) Directly or adhered to the non-inorganic material-adhering surface side of the film A
Film thickness of 15 to 60 μm laminated through layers
Heat-sealable film mainly composed of polyethylene
A laminated film, wherein the inorganic substance is aluminum or the like.
Or SiOx (where 1.5 <x <1.9)
A biaxial film of film A and film B
The refractive index in the direction satisfies the following formula 1 and the density is 1.400.
~ 1.420 g / cm^ThreeAnd of the laminated film
Water vapor transmission rate is 1.5g / m^Two・ Is less than 24 hours
Tear strength is 10 to 10 in longitudinal and / or transverse direction
Achieved by a tear-resistant moisture-proof packaging material which is 80 g
You. [0009] (Equation 2)     0.100 ≧ N_TD-N_MD≧ 0.010 (I) (However, N_TD: Refractive index in the lateral direction of the film, N_MD: Hui
It is the refractive index in the vertical direction of the lum. ) Hereinafter, the present invention will be described in detail. [0010] Biaxially oriented polyethylene tele in the present invention
The phthalate films (films A and B) have an acid component of 9
5% by mole or more of terephthalic acid, glycol component
Substantially 95 mol% or more of ethylene glycol
Biaxially oriented film formed from a linear polymer
You. This biaxially oriented film is bent in the biaxial direction.
Fold rate difference (N_TD-N_MD) Is in the range of 0.010 to 0.100.
It must be in the enclosure. This difference in refractive index is 0.01
If it is smaller than 0, the tear strength in the transverse direction of the film will be high.
Hand-cutting property does not appear. On the other hand, it becomes larger than 0.100
And the stability of the film cannot be obtained, making film formation difficult.
It is preferable because it is easy to cut
Absent. Where N_TDIs the refractive index in the transverse direction of the film,
N_MDIs the refractive index in the longitudinal direction of the film. The biaxially oriented film further has a density
1.400-1.420 g / cm^ThreeAnd the thickness is 8 to
It needs to be 20 μm. 1.400 film density
g / cm^ThreeIf it is less than 1, easy tearing is inferior and it is not preferable.
No. If the thickness of the film is less than 8 μm,
It is difficult to handle after applying inorganic matter to the ilum, and
Gas barrier properties are easily lost, while thicknesses greater than 20 μm
In this case, the flexibility after bag making is impaired, and the tearability is insufficient.
Minutes. The refractive index and the density are determined by the draw ratio in the longitudinal direction.
2.6 to 3.3 times, transverse stretching ratio 4.0 to 6.0
Select the condition from the heat setting temperature range of 230 to 245 ° C
Then, it can be obtained by biaxial stretching and heat setting. Delay
As the stretching method, sequential biaxial stretching method, simultaneous biaxial stretching method, etc. are adopted.
can do. [0014] The biaxially oriented film has good lubricity (running
Containing fine inert particles from the viewpoint of ensuring
it can. The inert particles may be inorganic particles or organic particles.
However, the average particle size of 1.2 to 3.0 μm may be set to 0.1.
001 to 0.2% by weight (based on polyethylene terephthale
G) It is preferable to include them. At that time, the transparency of the film
To maintain lightness, refraction characteristics close to the film's refractive index
Are preferred, and the average particle size and content are adjusted.
It is desirable to do. In the present invention, the biaxially oriented polymer
Using a styrene terephthalate film as film B
You. Further, the biaxially oriented polyethylene terephthalate film
Aluminum or SiOx (but 1.5
<X <1.9, preferably 1.5 <x <1.8)
Inorganic deposition film with silicon oxide deposited under reduced pressure
The film is used as film A. To deposit aluminum
Can form a metallic glossy moisture-proof thin layer, while silicon oxide
Can form a moisture-proof thin layer having excellent transparency.
The value of x of silicon oxide is 1.5 or less or 1.9 or more.
Those obtained are inferior in moisture-proof properties and are not preferred. Silicon oxide
The value of x in (SiOx) is the amount of residual oxygen (air) in the vacuum pot
Can be adjusted. Thin SiOx to be deposited
When the film exceeds about 500mm, the gas prevention effect is proportional to the film thickness
Not to improve, and transparency,
400-600mm, because productivity will decrease
Furthermore, 450 to 550 °, especially around 500 ° is preferred.
The aluminum thin film is preferably 300-600mm.
No. To adjust the film thickness, a biaxial alignment
Adjust the speed of the ethylene terephthalate film.
And can be done by [0016] Aluminum or silicon oxide on the film
As a method of applying the inorganic substance, an inorganic substance is applied on the film.
You can use what is known as
You. The heat-sealing film in the present invention is
A film having a polyethylene content of at least 60%.
You. The ratio of polyethylene is preferably 80% or more. Poly
Although the type of ethylene is not specified, low-density polyethylene
Preferred is ethylene. Such polyethylene includes gas
In terms of imparting barrier properties, for example, ethylene vinyl alcohol
Cole copolymer (trade name: EVAL)
Is preferred. The production of a heat-sealing film is usually carried out by
The inflation method is used. Extruder Ring Die
Diameter D₁, Product tube diameter D_TwoThen D_Two
/ D ₁Is not less than 1.1 to help easy tearing.
It is preferable from the following. Can be stretched in the direction of film transport
It is possible. In this case, the discharge speed from the extruder die
R ₁, The final speed of film formation is R_TwoThen R_Two/ R₁Is the value of
It is preferably 1.1 or more. To stretch in the longitudinal direction
In this case, if the shrinkage in the width direction is suppressed,
Improved and preferred. Other than the inflation method
Can be used. For example, by the T-die method,
The rum can be extruded and laminated. The thickness of the heat sealing film is 15
〜60 μm. If this thickness is less than 15 μm, the packaging material
Insufficient strength and handling as a material
When the thickness is large, tearability and flexibility are insufficient. In the present invention, film A, ie,
Biaxially oriented polyethylene tereph with inorganics deposited under reduced pressure
Film B, sand on the side of the tartary film where the inorganic material is
That is, the biaxially oriented polyethylene terephthalate film is
Further, the film C, that is, heat
Film is laminated. The film A and the film B are laminated by an adhesive
The usual adhesive lamination method using a chemical is used,
Minimize the chance of touching the surface of the inorganic material of ILM A
Is preferred in that it retains the moisture-proof function. Therefore Hui
Apply adhesive to one side of film B, dry it and add film A
It is preferable to perform hot press lamination. Film B is usually
Printing is performed because it is the outermost layer of the packaging material
Prints on the side in contact with film A (back side)
Is preferable in terms of color expression. Sometimes outside (front side
Side). Mark on back side of film B
When printing, an adhesive layer should be formed on the printed layer.
And The adhesive is, for example, polyester-based (a
Sophthalate copolymer), polyester-acrylic
Is preferably used. Film A (or a laminated film of films A and B)
Film) and film C are usually laminated by extrusion laminating.
G method is used. At that time, film C is already ready for production.
Is used when sandwich lamination is used.
It is. For example, a laminated film of films A and B is used as a base material.
A flat die is placed on the film A side of the laminated film.
Extruded polyethylene, especially low-density polyethylene.
Laminate film C before ethylene is cooled and solidified
Then, they are laminated by cooling. In this case extrusion from the die
Polyethylene acts as an adhesive. Also,
Using the laminated film as a base material, a film A of the film
On the side of the surface, use a flat die to
Extrude the heat-sealable polymer and immediately
The layers can be laminated by cooling under pressure. This
In the case of, also interpose polyethylene as an adhesive layer
You can also. In any case, the film A
Corona treatment or alkyl titanate treatment on the inorganic surface
Anchor coating with an anchor coating agent
It is preferable to increase the adhesion to ethylene or film C.
New In the present invention, the product of films A, B and C
The layer film has a moisture-proof property, that is, a water vapor transmission rate of 1.5 g.
r / m^Two・ It is necessary to be 24 hours or less. this
1.5 gr / m transmittance^Two・ It becomes larger than 24hr
Unsatisfactory as a moisture-proof material. This moisture barrier is excellent
The packaging material of the present invention,
Suitable for packaging of medicines, chemicals, etc. In the present invention, the number of the laminated films is small.
Tear strength in one direction (longitudinal or transverse) is 1
It must be 0-80 gr. Usually next to laminated film
Direction, this tear strength is obtained, but lower
Insufficient strength as packaging material, while greater than 80 gr
It is not easy to tear. The laminated film also has a low oxygen permeability.
Crust, especially 0.05cc / m^Two・ Hr ・ atm or less
I can wait. Therefore, the contents deteriorate due to the permeation of oxygen.
Suitable for packaging of foods and the like. The packaging material of the present invention has excellent tearability.
Has two V-shaped notches in the opening
Can be easily opened by hand
You. Therefore, use opening means such as so-called tear tape.
It has the advantage of not having to be added. [0029] The present invention will be further described below with reference to examples.
You. In addition, the measuring method of the physical property value in the present invention is as follows.
It is. (1) Film thickness: micrometer (JIS B7
502) and according to the method of JISC 2318. (2) Refractive index of film: Measured by Atsube refractometer. (3) Film density: using a density gradient tube. (4) Water vapor transmission rate: JIS Z 0208 (moisture permeable cup)
Method). (5) Tear strength: J
According to the method of ISP 8116. (6) Tearability: Linearity of the cutting line at a tear strength of 80 g or less
Good ○, but the cutting line is slightly bent at 80g or less
△, when the tear strength is greater than 80 gr or cut at 80 g
× with a broken wire. Examples 1 and 2, Comparative Examples 1-4 Average particle size
Contains 0.05% by weight of 2.3 μm silica aggregated particles
Melt extrusion of polyethylene terephthalate from a die and rapid cooling
To make an unstretched film, and then the film is
Stretched 3.0 to 3.6 times, 3.8 to 4.5 times in the horizontal direction,
Then heat set at 210-245 ° C, and after cooling,
Slit to width, 12μm thick biaxial with characteristics shown in Table 1.
An oriented polyethylene terephthalate film was obtained. this
Was used for film A and as film B. One side of the film for film A is made of SiOx
(However, x = 1.6 or 2) or aluminum is vacuum
Film A was deposited by vapor deposition. Film for film B
After printing on one side of the printer, the polyester
Resin (trade name Byron) with methyl ethyl ketone and toluene
Apply a solution dissolved in a mixed solvent of ene and dry at 70 ° C
To form a film having a thickness of 2 to 7 μm.
Was. [0032] Film A deposition surface and film B resin coating
Combine with the fabric surface and press with a roller heated to 120 ° C,
This was a two-layer laminated film. A film A was placed on the film A side of the obtained laminated film.
After anchoring with lukir titanate,
Extrusion of high density polyethylene from die to 20μm thickness
Immediately followed by polyethylene film as film C
(Tamapoly SB51-40 μm thick) and crimped
To form a composite film. The characteristics of this film
It is shown in Table 1. Example 3, Comparative Example 5
12 μm thick biaxial arrangement having the characteristics shown in Table 1 by the same method
A directional polyethylene terephthalate film was obtained. further
Performed in the same manner as in Examples 1 and 2 to obtain a laminated film
Was. The low density is provided on the film A side of the laminated film.
Extrude polyethylene to a thickness of 20 μm, laminate
Extrude 20 μm thick polyethylene on top of this
To form a composite film. Table 1 shows the characteristics of this film. [0037] [Table 1] [0038] As described above, the present invention has excellent moisture-proof properties, and
Incineration as it is easy to cut and does not use aluminum foil
Economical provision of packaging materials with excellent pollution control properties
It has high industrial value.

Continuation of the front page (56) References JP-A-6-155682 (JP, A) JP-A-5-345383 (JP, A) JP-A-5-4645 (JP, A) JP-A-55-111258 (JP) , A) Actually open 58-58-136 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (1)

(57) [Claim 1] (A) Biaxially oriented polyethylene terephthalate film having a thickness of 8 to 20 μm on which an inorganic substance is applied under reduced pressure, and (B) an inorganic substance application of the film A A biaxially oriented polyethylene terephthalate film having a thickness of 8 to 20 μm laminated on the surface side via an adhesive layer, and (C) a film laminated directly or via an adhesive layer on the non-inorganic substance-adhering surface side of the film A A laminated film comprising a heat-sealing film mainly composed of polyethylene having a thickness of 15 to 60 μm, wherein the inorganic material is aluminum or SiO 2.
x (provided that 1.5 <x <1.9), and the biaxial refractive indexes of the film A and the film B satisfy the following formula 1 and the density is 1.400 to 1. .42
0 g / cm ³ and and easy splitting property moistureproof packaging material water vapor permeability of the laminated film is not more than 1.5 g / m ² · 24 hr or and tear strength are 10~80g in longitudinal and / or transverse direction. 0.100 ≧ N _TD −N _MD ≧ 0.010 (I) (where, N _{TD is} the refractive index of the film in the horizontal direction, and N _MD is the refractive index of the film in the vertical direction.)